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 and set @code{GUIX_ENVIRONMENT} to that.
5424 This is equivalent to making @file{~/.guix-profile} a symlink to the
5425 actual profile within the container.
5426 Linking will fail and abort the environment if the directory already
5427 exists, which will certainly be the case if @command{guix environment}
5428 was invoked in the user's home directory.
5430 Certain packages are configured to look in @file{~/.guix-profile} for
5431 configuration files and data;@footnote{For example, the
5432 @code{fontconfig} package inspects @file{~/.guix-profile/share/fonts}
5433 for additional fonts.} @option{--link-profile} allows these programs to
5434 behave as expected within the environment.
5436 @item --user=@var{user}
5437 @itemx -u @var{user}
5438 For containers, use the username @var{user} in place of the current
5439 user. The generated @file{/etc/passwd} entry within the container will
5440 contain the name @var{user}, the home directory will be
5441 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
5442 the UID and GID inside the container are 1000. @var{user}
5443 need not exist on the system.
5445 Additionally, any shared or exposed path (see @option{--share} and
5446 @option{--expose} respectively) whose target is within the current user's
5447 home directory will be remapped relative to @file{/home/USER}; this
5448 includes the automatic mapping of the current working directory.
5451 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
5453 guix environment --container --user=foo \
5454 --expose=$HOME/test \
5455 --expose=/tmp/target=$HOME/target
5458 While this will limit the leaking of user identity through home paths
5459 and each of the user fields, this is only one useful component of a
5460 broader privacy/anonymity solution---not one in and of itself.
5463 For containers, the default behavior is to share the current working
5464 directory with the isolated container and immediately change to that
5465 directory within the container. If this is undesirable,
5466 @option{--no-cwd} will cause the current working directory to @emph{not}
5467 be automatically shared and will change to the user's home directory
5468 within the container instead. See also @option{--user}.
5470 @item --expose=@var{source}[=@var{target}]
5471 @itemx --share=@var{source}[=@var{target}]
5472 For containers, @option{--expose} (resp. @option{--share}) exposes the
5473 file system @var{source} from the host system as the read-only
5474 (resp. writable) file system @var{target} within the container. If
5475 @var{target} is not specified, @var{source} is used as the target mount
5476 point in the container.
5478 The example below spawns a Guile REPL in a container in which the user's
5479 home directory is accessible read-only via the @file{/exchange}
5483 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
5488 @command{guix environment}
5489 also supports all of the common build options that @command{guix
5490 build} supports (@pxref{Common Build Options}) as well as package
5491 transformation options (@pxref{Package Transformation Options}).
5493 @node Invoking guix pack
5494 @section Invoking @command{guix pack}
5496 Occasionally you want to pass software to people who are not (yet!)
5497 lucky enough to be using Guix. You'd tell them to run @command{guix
5498 package -i @var{something}}, but that's not possible in this case. This
5499 is where @command{guix pack} comes in.
5502 If you are looking for ways to exchange binaries among machines that
5503 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
5504 publish}, and @ref{Invoking guix archive}.
5509 @cindex application bundle
5510 @cindex software bundle
5511 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
5512 @dfn{software bundle}: it creates a tarball or some other archive
5513 containing the binaries of the software you're interested in, and all
5514 its dependencies. The resulting archive can be used on any machine that
5515 does not have Guix, and people can run the exact same binaries as those
5516 you have with Guix. The pack itself is created in a bit-reproducible
5517 fashion, so anyone can verify that it really contains the build results
5518 that you pretend to be shipping.
5520 For example, to create a bundle containing Guile, Emacs, Geiser, and all
5521 their dependencies, you can run:
5524 $ guix pack guile emacs geiser
5526 /gnu/store/@dots{}-pack.tar.gz
5529 The result here is a tarball containing a @file{/gnu/store} directory
5530 with all the relevant packages. The resulting tarball contains a
5531 @dfn{profile} with the three packages of interest; the profile is the
5532 same as would be created by @command{guix package -i}. It is this
5533 mechanism that is used to create Guix's own standalone binary tarball
5534 (@pxref{Binary Installation}).
5536 Users of this pack would have to run
5537 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
5538 find inconvenient. To work around it, you can create, say, a
5539 @file{/opt/gnu/bin} symlink to the profile:
5542 guix pack -S /opt/gnu/bin=bin guile emacs geiser
5546 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
5548 @cindex relocatable binaries, with @command{guix pack}
5549 What if the recipient of your pack does not have root privileges on
5550 their machine, and thus cannot unpack it in the root file system? In
5551 that case, you will want to use the @option{--relocatable} option (see
5552 below). This option produces @dfn{relocatable binaries}, meaning they
5553 they can be placed anywhere in the file system hierarchy: in the example
5554 above, users can unpack your tarball in their home directory and
5555 directly run @file{./opt/gnu/bin/guile}.
5557 @cindex Docker, build an image with guix pack
5558 Alternatively, you can produce a pack in the Docker image format using
5559 the following command:
5562 guix pack -f docker -S /bin=bin guile guile-readline
5566 The result is a tarball that can be passed to the @command{docker load}
5567 command, followed by @code{docker run}:
5570 docker load < @var{file}
5571 docker run -ti guile-guile-readline /bin/guile
5575 where @var{file} is the image returned by @var{guix pack}, and
5576 @code{guile-guile-readline} is its ``image tag''. See the
5577 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5578 documentation} for more information.
5580 @cindex Singularity, build an image with guix pack
5581 @cindex SquashFS, build an image with guix pack
5582 Yet another option is to produce a SquashFS image with the following
5586 guix pack -f squashfs bash guile emacs geiser
5590 The result is a SquashFS file system image that can either be mounted or
5591 directly be used as a file system container image with the
5592 @uref{https://www.sylabs.io/docs/, Singularity container execution
5593 environment}, using commands like @command{singularity shell} or
5594 @command{singularity exec}.
5596 Several command-line options allow you to customize your pack:
5599 @item --format=@var{format}
5600 @itemx -f @var{format}
5601 Produce a pack in the given @var{format}.
5603 The available formats are:
5607 This is the default format. It produces a tarball containing all the
5608 specified binaries and symlinks.
5611 This produces a tarball that follows the
5612 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
5613 Docker Image Specification}. The ``repository name'' as it appears in
5614 the output of the @command{docker images} command is computed from
5615 package names passed on the command line or in the manifest file.
5618 This produces a SquashFS image containing all the specified binaries and
5619 symlinks, as well as empty mount points for virtual file systems like
5623 Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
5624 For that reason, @command{guix pack -f squashfs} always implies @code{-S
5625 /bin=bin}. Thus, your @command{guix pack} invocation must always start
5626 with something like:
5629 guix pack -f squashfs bash @dots{}
5632 If you forget the @code{bash} (or similar) package, @command{singularity
5633 run} and @command{singularity exec} will fail with an unhelpful ``no
5634 such file or directory'' message.
5638 @cindex relocatable binaries
5641 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
5642 anywhere in the file system hierarchy and run from there.
5644 When this option is passed once, the resulting binaries require support for
5645 @dfn{user namespaces} in the kernel Linux; when passed
5646 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
5647 PRoot support, can be thought of as the abbreviation of ``Really
5648 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to
5649 other techniques if user namespaces are unavailable, and essentially
5650 work anywhere---see below for the implications.
5652 For example, if you create a pack containing Bash with:
5655 guix pack -RR -S /mybin=bin bash
5659 ...@: you can copy that pack to a machine that lacks Guix, and from your
5660 home directory as a normal user, run:
5668 In that shell, if you type @code{ls /gnu/store}, you'll notice that
5669 @file{/gnu/store} shows up and contains all the dependencies of
5670 @code{bash}, even though the machine actually lacks @file{/gnu/store}
5671 altogether! That is probably the simplest way to deploy Guix-built
5672 software on a non-Guix machine.
5675 By default, relocatable binaries rely on the @dfn{user namespace} feature of
5676 the kernel Linux, which allows unprivileged users to mount or change root.
5677 Old versions of Linux did not support it, and some GNU/Linux distributions
5680 To produce relocatable binaries that work even in the absence of user
5681 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
5682 case, binaries will try user namespace support and fall back to another
5683 @dfn{execution engine} if user namespaces are not supported. The
5684 following execution engines are supported:
5688 Try user namespaces and fall back to PRoot if user namespaces are not
5689 supported (see below).
5692 Try user namespaces and fall back to Fakechroot if user namespaces are
5693 not supported (see below).
5696 Run the program through user namespaces and abort if they are not
5700 Run through PRoot. The @uref{https://proot-me.github.io/, PRoot} program
5701 provides the necessary
5702 support for file system virtualization. It achieves that by using the
5703 @code{ptrace} system call on the running program. This approach has the
5704 advantage to work without requiring special kernel support, but it incurs
5705 run-time overhead every time a system call is made.
5708 Run through Fakechroot. @uref{https://github.com/dex4er/fakechroot/,
5709 Fakechroot} virtualizes file system accesses by intercepting calls to C
5710 library functions such as @code{open}, @code{stat}, @code{exec}, and so
5711 on. Unlike PRoot, it incurs very little overhead. However, it does not
5712 always work: for example, some file system accesses made from within the
5713 C library are not intercepted, and file system accesses made @i{via}
5714 direct syscalls are not intercepted either, leading to erratic behavior.
5717 @vindex GUIX_EXECUTION_ENGINE
5718 When running a wrapped program, you can explicitly request one of the
5719 execution engines listed above by setting the
5720 @code{GUIX_EXECUTION_ENGINE} environment variable accordingly.
5723 @cindex entry point, for Docker images
5724 @item --entry-point=@var{command}
5725 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
5726 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
5727 support it. @var{command} must be relative to the profile contained in the
5730 The entry point specifies the command that tools like @code{docker run} or
5731 @code{singularity run} automatically start by default. For example, you can
5735 guix pack -f docker --entry-point=bin/guile guile
5738 The resulting pack can easily be loaded and @code{docker run} with no extra
5739 arguments will spawn @code{bin/guile}:
5742 docker load -i pack.tar.gz
5743 docker run @var{image-id}
5746 @item --expression=@var{expr}
5747 @itemx -e @var{expr}
5748 Consider the package @var{expr} evaluates to.
5750 This has the same purpose as the same-named option in @command{guix
5751 build} (@pxref{Additional Build Options, @option{--expression} in
5752 @command{guix build}}).
5754 @item --manifest=@var{file}
5755 @itemx -m @var{file}
5756 Use the packages contained in the manifest object returned by the Scheme
5757 code in @var{file}. This option can be repeated several times, in which
5758 case the manifests are concatenated.
5760 This has a similar purpose as the same-named option in @command{guix
5761 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
5762 same manifest files. It allows you to define a collection of packages
5763 once and use it both for creating profiles and for creating archives
5764 for use on machines that do not have Guix installed. Note that you can
5765 specify @emph{either} a manifest file @emph{or} a list of packages,
5768 @item --system=@var{system}
5769 @itemx -s @var{system}
5770 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
5771 the system type of the build host.
5773 @item --target=@var{triplet}
5774 @cindex cross-compilation
5775 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
5776 as @code{"aarch64-linux-gnu"} (@pxref{Specifying target triplets, GNU
5777 configuration triplets,, autoconf, Autoconf}).
5779 @item --compression=@var{tool}
5780 @itemx -C @var{tool}
5781 Compress the resulting tarball using @var{tool}---one of @code{gzip},
5782 @code{zstd}, @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no
5785 @item --symlink=@var{spec}
5786 @itemx -S @var{spec}
5787 Add the symlinks specified by @var{spec} to the pack. This option can
5788 appear several times.
5790 @var{spec} has the form @code{@var{source}=@var{target}}, where
5791 @var{source} is the symlink that will be created and @var{target} is the
5794 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
5795 symlink pointing to the @file{bin} sub-directory of the profile.
5797 @item --save-provenance
5798 Save provenance information for the packages passed on the command line.
5799 Provenance information includes the URL and commit of the channels in use
5802 Provenance information is saved in the
5803 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
5804 usual package metadata---the name and version of each package, their
5805 propagated inputs, and so on. It is useful information to the recipient of
5806 the pack, who then knows how the pack was (supposedly) obtained.
5808 This option is not enabled by default because, like timestamps, provenance
5809 information contributes nothing to the build process. In other words, there
5810 is an infinity of channel URLs and commit IDs that can lead to the same pack.
5811 Recording such ``silent'' metadata in the output thus potentially breaks the
5812 source-to-binary bitwise reproducibility property.
5814 @item --root=@var{file}
5815 @itemx -r @var{file}
5816 @cindex garbage collector root, for packs
5817 Make @var{file} a symlink to the resulting pack, and register it as a garbage
5820 @item --localstatedir
5821 @itemx --profile-name=@var{name}
5822 Include the ``local state directory'', @file{/var/guix}, in the resulting
5823 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
5824 profile---by default @var{name} is @code{guix-profile}, which corresponds to
5825 @file{~root/.guix-profile}.
5827 @file{/var/guix} contains the store database (@pxref{The Store}) as well
5828 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
5829 the pack means that the store is ``complete'' and manageable by Guix;
5830 not providing it pack means that the store is ``dead'': items cannot be
5831 added to it or removed from it after extraction of the pack.
5833 One use case for this is the Guix self-contained binary tarball
5834 (@pxref{Binary Installation}).
5838 Print the name of the derivation that builds the pack.
5841 Use the bootstrap binaries to build the pack. This option is only
5842 useful to Guix developers.
5845 In addition, @command{guix pack} supports all the common build options
5846 (@pxref{Common Build Options}) and all the package transformation
5847 options (@pxref{Package Transformation Options}).
5850 @node The GCC toolchain
5851 @section The GCC toolchain
5855 @cindex linker wrapper
5856 @cindex toolchain, for C development
5857 @cindex toolchain, for Fortran development
5859 If you need a complete toolchain for compiling and linking C or C++
5860 source code, use the @code{gcc-toolchain} package. This package
5861 provides a complete GCC toolchain for C/C++ development, including GCC
5862 itself, the GNU C Library (headers and binaries, plus debugging symbols
5863 in the @code{debug} output), Binutils, and a linker wrapper.
5865 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
5866 passed to the linker, add corresponding @code{-rpath} arguments, and
5867 invoke the actual linker with this new set of arguments. You can instruct the
5868 wrapper to refuse to link against libraries not in the store by setting the
5869 @env{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
5871 The package @code{gfortran-toolchain} provides a complete GCC toolchain
5872 for Fortran development. For other languages, please use
5873 @samp{guix search gcc toolchain} (@pxref{guix-search,, Invoking guix package}).
5876 @node Invoking guix git authenticate
5877 @section Invoking @command{guix git authenticate}
5879 The @command{guix git authenticate} command authenticates a Git checkout
5880 following the same rule as for channels (@pxref{channel-authentication,
5881 channel authentication}). That is, starting from a given commit, it
5882 ensures that all subsequent commits are signed by an OpenPGP key whose
5883 fingerprint appears in the @file{.guix-authorizations} file of its
5886 You will find this command useful if you maintain a channel. But in
5887 fact, this authentication mechanism is useful in a broader context, so
5888 you might want to use it for Git repositories that have nothing to do
5891 The general syntax is:
5894 guix git authenticate @var{commit} @var{signer} [@var{options}@dots{}]
5897 By default, this command authenticates the Git checkout in the current
5898 directory; it outputs nothing and exits with exit code zero on success
5899 and non-zero on failure. @var{commit} above denotes the first commit
5900 where authentication takes place, and @var{signer} is the OpenPGP
5901 fingerprint of public key used to sign @var{commit}. Together, they
5902 form a ``channel introduction'' (@pxref{channel-authentication, channel
5903 introduction}). The options below allow you to fine-tune the process.
5906 @item --repository=@var{directory}
5907 @itemx -r @var{directory}
5908 Open the Git repository in @var{directory} instead of the current
5911 @item --keyring=@var{reference}
5912 @itemx -k @var{reference}
5913 Load OpenPGP keyring from @var{reference}, the reference of a branch
5914 such as @code{origin/keyring} or @code{my-keyring}. The branch must
5915 contain OpenPGP public keys in @file{.key} files, either in binary form
5916 or ``ASCII-armored''. By default the keyring is loaded from the branch
5917 named @code{keyring}.
5920 Display commit signing statistics upon completion.
5922 @item --cache-key=@var{key}
5923 Previously-authenticated commits are cached in a file under
5924 @file{~/.cache/guix/authentication}. This option forces the cache to be
5925 stored in file @var{key} in that directory.
5927 @item --historical-authorizations=@var{file}
5928 By default, any commit whose parent commit(s) lack the
5929 @file{.guix-authorizations} file is considered inauthentic. In
5930 contrast, this option considers the authorizations in @var{file} for any
5931 commit that lacks @file{.guix-authorizations}. The format of @var{file}
5932 is the same as that of @file{.guix-authorizations}
5933 (@pxref{channel-authorizations, @file{.guix-authorizations} format}).
5937 @c *********************************************************************
5938 @node Programming Interface
5939 @chapter Programming Interface
5941 GNU Guix provides several Scheme programming interfaces (APIs) to
5942 define, build, and query packages. The first interface allows users to
5943 write high-level package definitions. These definitions refer to
5944 familiar packaging concepts, such as the name and version of a package,
5945 its build system, and its dependencies. These definitions can then be
5946 turned into concrete build actions.
5948 Build actions are performed by the Guix daemon, on behalf of users. In a
5949 standard setup, the daemon has write access to the store---the
5950 @file{/gnu/store} directory---whereas users do not. The recommended
5951 setup also has the daemon perform builds in chroots, under specific
5952 build users, to minimize interference with the rest of the system.
5955 Lower-level APIs are available to interact with the daemon and the
5956 store. To instruct the daemon to perform a build action, users actually
5957 provide it with a @dfn{derivation}. A derivation is a low-level
5958 representation of the build actions to be taken, and the environment in
5959 which they should occur---derivations are to package definitions what
5960 assembly is to C programs. The term ``derivation'' comes from the fact
5961 that build results @emph{derive} from them.
5963 This chapter describes all these APIs in turn, starting from high-level
5964 package definitions.
5967 * Package Modules:: Packages from the programmer's viewpoint.
5968 * Defining Packages:: Defining new packages.
5969 * Build Systems:: Specifying how packages are built.
5970 * The Store:: Manipulating the package store.
5971 * Derivations:: Low-level interface to package derivations.
5972 * The Store Monad:: Purely functional interface to the store.
5973 * G-Expressions:: Manipulating build expressions.
5974 * Invoking guix repl:: Programming Guix in Guile
5977 @node Package Modules
5978 @section Package Modules
5980 From a programming viewpoint, the package definitions of the
5981 GNU distribution are provided by Guile modules in the @code{(gnu packages
5982 @dots{})} name space@footnote{Note that packages under the @code{(gnu
5983 packages @dots{})} module name space are not necessarily ``GNU
5984 packages''. This module naming scheme follows the usual Guile module
5985 naming convention: @code{gnu} means that these modules are distributed
5986 as part of the GNU system, and @code{packages} identifies modules that
5987 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5988 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5989 module exports a variable named @code{emacs}, which is bound to a
5990 @code{<package>} object (@pxref{Defining Packages}).
5992 The @code{(gnu packages @dots{})} module name space is
5993 automatically scanned for packages by the command-line tools. For
5994 instance, when running @code{guix install emacs}, all the @code{(gnu
5995 packages @dots{})} modules are scanned until one that exports a package
5996 object whose name is @code{emacs} is found. This package search
5997 facility is implemented in the @code{(gnu packages)} module.
5999 @cindex customization, of packages
6000 @cindex package module search path
6001 Users can store package definitions in modules with different
6002 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
6003 name and module name must match. For instance, the @code{(my-packages
6004 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
6005 relative to the load path specified with @option{--load-path} or
6006 @env{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
6007 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
6008 these package definitions visible to the user interfaces:
6012 By adding the directory containing your package modules to the search path
6013 with the @code{-L} flag of @command{guix package} and other commands
6014 (@pxref{Common Build Options}), or by setting the @env{GUIX_PACKAGE_PATH}
6015 environment variable described below.
6018 By defining a @dfn{channel} and configuring @command{guix pull} so that it
6019 pulls from it. A channel is essentially a Git repository containing package
6020 modules. @xref{Channels}, for more information on how to define and use
6024 @env{GUIX_PACKAGE_PATH} works similarly to other search path variables:
6026 @defvr {Environment Variable} GUIX_PACKAGE_PATH
6027 This is a colon-separated list of directories to search for additional
6028 package modules. Directories listed in this variable take precedence
6029 over the own modules of the distribution.
6032 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
6033 each package is built based solely on other packages in the
6034 distribution. The root of this dependency graph is a small set of
6035 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
6036 bootstrap)} module. For more information on bootstrapping,
6037 @pxref{Bootstrapping}.
6039 @node Defining Packages
6040 @section Defining Packages
6042 The high-level interface to package definitions is implemented in the
6043 @code{(guix packages)} and @code{(guix build-system)} modules. As an
6044 example, the package definition, or @dfn{recipe}, for the GNU Hello
6045 package looks like this:
6048 (define-module (gnu packages hello)
6049 #:use-module (guix packages)
6050 #:use-module (guix download)
6051 #:use-module (guix build-system gnu)
6052 #:use-module (guix licenses)
6053 #:use-module (gnu packages gawk))
6055 (define-public hello
6061 (uri (string-append "mirror://gnu/hello/hello-" version
6065 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
6066 (build-system gnu-build-system)
6067 (arguments '(#:configure-flags '("--enable-silent-rules")))
6068 (inputs `(("gawk" ,gawk)))
6069 (synopsis "Hello, GNU world: An example GNU package")
6070 (description "Guess what GNU Hello prints!")
6071 (home-page "https://www.gnu.org/software/hello/")
6076 Without being a Scheme expert, the reader may have guessed the meaning
6077 of the various fields here. This expression binds the variable
6078 @code{hello} to a @code{<package>} object, which is essentially a record
6079 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
6080 This package object can be inspected using procedures found in the
6081 @code{(guix packages)} module; for instance, @code{(package-name hello)}
6082 returns---surprise!---@code{"hello"}.
6084 With luck, you may be able to import part or all of the definition of
6085 the package you are interested in from another repository, using the
6086 @code{guix import} command (@pxref{Invoking guix import}).
6088 In the example above, @var{hello} is defined in a module of its own,
6089 @code{(gnu packages hello)}. Technically, this is not strictly
6090 necessary, but it is convenient to do so: all the packages defined in
6091 modules under @code{(gnu packages @dots{})} are automatically known to
6092 the command-line tools (@pxref{Package Modules}).
6094 There are a few points worth noting in the above package definition:
6098 The @code{source} field of the package is an @code{<origin>} object
6099 (@pxref{origin Reference}, for the complete reference).
6100 Here, the @code{url-fetch} method from @code{(guix download)} is used,
6101 meaning that the source is a file to be downloaded over FTP or HTTP.
6103 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
6104 the GNU mirrors defined in @code{(guix download)}.
6106 The @code{sha256} field specifies the expected SHA256 hash of the file
6107 being downloaded. It is mandatory, and allows Guix to check the
6108 integrity of the file. The @code{(base32 @dots{})} form introduces the
6109 base32 representation of the hash. You can obtain this information with
6110 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
6111 hash} (@pxref{Invoking guix hash}).
6114 When needed, the @code{origin} form can also have a @code{patches} field
6115 listing patches to be applied, and a @code{snippet} field giving a
6116 Scheme expression to modify the source code.
6119 @cindex GNU Build System
6120 The @code{build-system} field specifies the procedure to build the
6121 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
6122 represents the familiar GNU Build System, where packages may be
6123 configured, built, and installed with the usual @code{./configure &&
6124 make && make check && make install} command sequence.
6127 The @code{arguments} field specifies options for the build system
6128 (@pxref{Build Systems}). Here it is interpreted by
6129 @var{gnu-build-system} as a request run @file{configure} with the
6130 @option{--enable-silent-rules} flag.
6136 What about these quote (@code{'}) characters? They are Scheme syntax to
6137 introduce a literal list; @code{'} is synonymous with @code{quote}.
6138 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
6139 for details. Here the value of the @code{arguments} field is a list of
6140 arguments passed to the build system down the road, as with @code{apply}
6141 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
6144 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
6145 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
6146 @code{#:configure-flags} is a keyword used to pass a keyword argument
6147 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
6151 The @code{inputs} field specifies inputs to the build process---i.e.,
6152 build-time or run-time dependencies of the package. Here, we define an
6153 input called @code{"gawk"} whose value is that of the @var{gawk}
6154 variable; @var{gawk} is itself bound to a @code{<package>} object.
6156 @cindex backquote (quasiquote)
6159 @cindex comma (unquote)
6163 @findex unquote-splicing
6164 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
6165 us to introduce a literal list in the @code{inputs} field, while
6166 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
6167 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
6170 Note that GCC, Coreutils, Bash, and other essential tools do not need to
6171 be specified as inputs here. Instead, @var{gnu-build-system} takes care
6172 of ensuring that they are present (@pxref{Build Systems}).
6174 However, any other dependencies need to be specified in the
6175 @code{inputs} field. Any dependency not specified here will simply be
6176 unavailable to the build process, possibly leading to a build failure.
6179 @xref{package Reference}, for a full description of possible fields.
6181 Once a package definition is in place, the
6182 package may actually be built using the @code{guix build} command-line
6183 tool (@pxref{Invoking guix build}), troubleshooting any build failures
6184 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
6185 package definition using the @command{guix edit} command
6186 (@pxref{Invoking guix edit}).
6187 @xref{Packaging Guidelines}, for
6188 more information on how to test package definitions, and
6189 @ref{Invoking guix lint}, for information on how to check a definition
6190 for style conformance.
6191 @vindex GUIX_PACKAGE_PATH
6192 Lastly, @pxref{Channels}, for information
6193 on how to extend the distribution by adding your own package definitions
6196 Finally, updating the package definition to a new upstream version
6197 can be partly automated by the @command{guix refresh} command
6198 (@pxref{Invoking guix refresh}).
6200 Behind the scenes, a derivation corresponding to the @code{<package>}
6201 object is first computed by the @code{package-derivation} procedure.
6202 That derivation is stored in a @file{.drv} file under @file{/gnu/store}.
6203 The build actions it prescribes may then be realized by using the
6204 @code{build-derivations} procedure (@pxref{The Store}).
6206 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
6207 Return the @code{<derivation>} object of @var{package} for @var{system}
6208 (@pxref{Derivations}).
6210 @var{package} must be a valid @code{<package>} object, and @var{system}
6211 must be a string denoting the target system type---e.g.,
6212 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
6213 must be a connection to the daemon, which operates on the store
6214 (@pxref{The Store}).
6218 @cindex cross-compilation
6219 Similarly, it is possible to compute a derivation that cross-builds a
6220 package for some other system:
6222 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
6223 @var{package} @var{target} [@var{system}]
6224 Return the @code{<derivation>} object of @var{package} cross-built from
6225 @var{system} to @var{target}.
6227 @var{target} must be a valid GNU triplet denoting the target hardware
6228 and operating system, such as @code{"aarch64-linux-gnu"}
6229 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
6232 @cindex package transformations
6233 @cindex input rewriting
6234 @cindex dependency tree rewriting
6235 Packages can be manipulated in arbitrary ways. An example of a useful
6236 transformation is @dfn{input rewriting}, whereby the dependency tree of
6237 a package is rewritten by replacing specific inputs by others:
6239 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
6240 [@var{rewrite-name}]
6241 Return a procedure that, when passed a package, replaces its direct and
6242 indirect dependencies (but not its implicit inputs) according to
6243 @var{replacements}. @var{replacements} is a list of package pairs; the
6244 first element of each pair is the package to replace, and the second one
6247 Optionally, @var{rewrite-name} is a one-argument procedure that takes
6248 the name of a package and returns its new name after rewrite.
6252 Consider this example:
6255 (define libressl-instead-of-openssl
6256 ;; This is a procedure to replace OPENSSL by LIBRESSL,
6258 (package-input-rewriting `((,openssl . ,libressl))))
6260 (define git-with-libressl
6261 (libressl-instead-of-openssl git))
6265 Here we first define a rewriting procedure that replaces @var{openssl}
6266 with @var{libressl}. Then we use it to define a @dfn{variant} of the
6267 @var{git} package that uses @var{libressl} instead of @var{openssl}.
6268 This is exactly what the @option{--with-input} command-line option does
6269 (@pxref{Package Transformation Options, @option{--with-input}}).
6271 The following variant of @code{package-input-rewriting} can match packages to
6272 be replaced by name rather than by identity.
6274 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
6275 Return a procedure that, given a package, applies the given @var{replacements} to
6276 all the package graph (excluding implicit inputs). @var{replacements} is a list of
6277 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
6278 @code{"guile@@2"}, and each procedure takes a matching package and returns a
6279 replacement for that package.
6282 The example above could be rewritten this way:
6285 (define libressl-instead-of-openssl
6286 ;; Replace all the packages called "openssl" with LibreSSL.
6287 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
6290 The key difference here is that, this time, packages are matched by spec and
6291 not by identity. In other words, any package in the graph that is called
6292 @code{openssl} will be replaced.
6294 A more generic procedure to rewrite a package dependency graph is
6295 @code{package-mapping}: it supports arbitrary changes to nodes in the
6298 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
6299 Return a procedure that, given a package, applies @var{proc} to all the packages
6300 depended on and returns the resulting package. The procedure stops recursion
6301 when @var{cut?} returns true for a given package.
6305 * package Reference:: The package data type.
6306 * origin Reference:: The origin data type.
6310 @node package Reference
6311 @subsection @code{package} Reference
6313 This section summarizes all the options available in @code{package}
6314 declarations (@pxref{Defining Packages}).
6316 @deftp {Data Type} package
6317 This is the data type representing a package recipe.
6321 The name of the package, as a string.
6323 @item @code{version}
6324 The version of the package, as a string.
6327 An object telling how the source code for the package should be
6328 acquired. Most of the time, this is an @code{origin} object, which
6329 denotes a file fetched from the Internet (@pxref{origin Reference}). It
6330 can also be any other ``file-like'' object such as a @code{local-file},
6331 which denotes a file from the local file system (@pxref{G-Expressions,
6332 @code{local-file}}).
6334 @item @code{build-system}
6335 The build system that should be used to build the package (@pxref{Build
6338 @item @code{arguments} (default: @code{'()})
6339 The arguments that should be passed to the build system. This is a
6340 list, typically containing sequential keyword-value pairs.
6342 @item @code{inputs} (default: @code{'()})
6343 @itemx @code{native-inputs} (default: @code{'()})
6344 @itemx @code{propagated-inputs} (default: @code{'()})
6345 @cindex inputs, of packages
6346 These fields list dependencies of the package. Each one is a list of
6347 tuples, where each tuple has a label for the input (a string) as its
6348 first element, a package, origin, or derivation as its second element,
6349 and optionally the name of the output thereof that should be used, which
6350 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
6351 more on package outputs). For example, the list below specifies three
6355 `(("libffi" ,libffi)
6356 ("libunistring" ,libunistring)
6357 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
6360 @cindex cross compilation, package dependencies
6361 The distinction between @code{native-inputs} and @code{inputs} is
6362 necessary when considering cross-compilation. When cross-compiling,
6363 dependencies listed in @code{inputs} are built for the @emph{target}
6364 architecture; conversely, dependencies listed in @code{native-inputs}
6365 are built for the architecture of the @emph{build} machine.
6367 @code{native-inputs} is typically used to list tools needed at
6368 build time, but not at run time, such as Autoconf, Automake, pkg-config,
6369 Gettext, or Bison. @command{guix lint} can report likely mistakes in
6370 this area (@pxref{Invoking guix lint}).
6372 @anchor{package-propagated-inputs}
6373 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
6374 specified packages will be automatically installed to profiles
6375 (@pxref{Features, the role of profiles in Guix}) alongside the package
6376 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
6377 package}}, for information on how @command{guix package} deals with
6380 For example this is necessary when packaging a C/C++ library that needs
6381 headers of another library to compile, or when a pkg-config file refers
6382 to another one @i{via} its @code{Requires} field.
6384 Another example where @code{propagated-inputs} is useful is for languages
6385 that lack a facility to record the run-time search path akin to the
6386 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
6387 more. When packaging libraries written in those languages, ensure they
6388 can find library code they depend on at run time by listing run-time
6389 dependencies in @code{propagated-inputs} rather than @code{inputs}.
6391 @item @code{outputs} (default: @code{'("out")})
6392 The list of output names of the package. @xref{Packages with Multiple
6393 Outputs}, for typical uses of additional outputs.
6395 @item @code{native-search-paths} (default: @code{'()})
6396 @itemx @code{search-paths} (default: @code{'()})
6397 A list of @code{search-path-specification} objects describing
6398 search-path environment variables honored by the package.
6400 @item @code{replacement} (default: @code{#f})
6401 This must be either @code{#f} or a package object that will be used as a
6402 @dfn{replacement} for this package. @xref{Security Updates, grafts},
6405 @item @code{synopsis}
6406 A one-line description of the package.
6408 @item @code{description}
6409 A more elaborate description of the package.
6411 @item @code{license}
6412 @cindex license, of packages
6413 The license of the package; a value from @code{(guix licenses)},
6414 or a list of such values.
6416 @item @code{home-page}
6417 The URL to the home-page of the package, as a string.
6419 @item @code{supported-systems} (default: @code{%supported-systems})
6420 The list of systems supported by the package, as strings of the form
6421 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
6423 @item @code{location} (default: source location of the @code{package} form)
6424 The source location of the package. It is useful to override this when
6425 inheriting from another package, in which case this field is not
6426 automatically corrected.
6430 @deffn {Scheme Syntax} this-package
6431 When used in the @emph{lexical scope} of a package field definition, this
6432 identifier resolves to the package being defined.
6434 The example below shows how to add a package as a native input of itself when
6442 ;; When cross-compiled, Guile, for example, depends on
6443 ;; a native version of itself. Add it here.
6444 (native-inputs (if (%current-target-system)
6445 `(("self" ,this-package))
6449 It is an error to refer to @code{this-package} outside a package definition.
6452 @node origin Reference
6453 @subsection @code{origin} Reference
6455 This section summarizes all the options available in @code{origin}
6456 declarations (@pxref{Defining Packages}).
6458 @deftp {Data Type} origin
6459 This is the data type representing a source code origin.
6463 An object containing the URI of the source. The object type depends on
6464 the @code{method} (see below). For example, when using the
6465 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
6466 values are: a URL represented as a string, or a list thereof.
6469 A procedure that handles the URI.
6474 @item @var{url-fetch} from @code{(guix download)}
6475 download a file from the HTTP, HTTPS, or FTP URL specified in the
6479 @item @var{git-fetch} from @code{(guix git-download)}
6480 clone the Git version control repository, and check out the revision
6481 specified in the @code{uri} field as a @code{git-reference} object; a
6482 @code{git-reference} looks like this:
6486 (url "https://git.savannah.gnu.org/git/hello.git")
6492 A bytevector containing the SHA-256 hash of the source. This is
6493 equivalent to providing a @code{content-hash} SHA256 object in the
6494 @code{hash} field described below.
6497 The @code{content-hash} object of the source---see below for how to use
6498 @code{content-hash}.
6500 You can obtain this information using @code{guix download}
6501 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
6504 @item @code{file-name} (default: @code{#f})
6505 The file name under which the source code should be saved. When this is
6506 @code{#f}, a sensible default value will be used in most cases. In case
6507 the source is fetched from a URL, the file name from the URL will be
6508 used. For version control checkouts, it is recommended to provide the
6509 file name explicitly because the default is not very descriptive.
6511 @item @code{patches} (default: @code{'()})
6512 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
6513 file-like objects}) pointing to patches to be applied to the source.
6515 This list of patches must be unconditional. In particular, it cannot
6516 depend on the value of @code{%current-system} or
6517 @code{%current-target-system}.
6519 @item @code{snippet} (default: @code{#f})
6520 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
6521 in the source directory. This is a convenient way to modify the source,
6522 sometimes more convenient than a patch.
6524 @item @code{patch-flags} (default: @code{'("-p1")})
6525 A list of command-line flags that should be passed to the @code{patch}
6528 @item @code{patch-inputs} (default: @code{#f})
6529 Input packages or derivations to the patching process. When this is
6530 @code{#f}, the usual set of inputs necessary for patching are provided,
6531 such as GNU@tie{}Patch.
6533 @item @code{modules} (default: @code{'()})
6534 A list of Guile modules that should be loaded during the patching
6535 process and while running the code in the @code{snippet} field.
6537 @item @code{patch-guile} (default: @code{#f})
6538 The Guile package that should be used in the patching process. When
6539 this is @code{#f}, a sensible default is used.
6543 @deftp {Data Type} content-hash @var{value} [@var{algorithm}]
6544 Construct a content hash object for the given @var{algorithm}, and with
6545 @var{value} as its hash value. When @var{algorithm} is omitted, assume
6546 it is @code{sha256}.
6548 @var{value} can be a literal string, in which case it is base32-decoded,
6549 or it can be a bytevector.
6551 The following forms are all equivalent:
6554 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj")
6555 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"
6557 (content-hash (base32
6558 "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"))
6559 (content-hash (base64 "kkb+RPaP7uyMZmu4eXPVkM4BN8yhRd8BTHLslb6f/Rc=")
6563 Technically, @code{content-hash} is currently implemented as a macro.
6564 It performs sanity checks at macro-expansion time, when possible, such
6565 as ensuring that @var{value} has the right size for @var{algorithm}.
6569 @section Build Systems
6571 @cindex build system
6572 Each package definition specifies a @dfn{build system} and arguments for
6573 that build system (@pxref{Defining Packages}). This @code{build-system}
6574 field represents the build procedure of the package, as well as implicit
6575 dependencies of that build procedure.
6577 Build systems are @code{<build-system>} objects. The interface to
6578 create and manipulate them is provided by the @code{(guix build-system)}
6579 module, and actual build systems are exported by specific modules.
6581 @cindex bag (low-level package representation)
6582 Under the hood, build systems first compile package objects to
6583 @dfn{bags}. A @dfn{bag} is like a package, but with less
6584 ornamentation---in other words, a bag is a lower-level representation of
6585 a package, which includes all the inputs of that package, including some
6586 that were implicitly added by the build system. This intermediate
6587 representation is then compiled to a derivation (@pxref{Derivations}).
6589 Build systems accept an optional list of @dfn{arguments}. In package
6590 definitions, these are passed @i{via} the @code{arguments} field
6591 (@pxref{Defining Packages}). They are typically keyword arguments
6592 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
6593 Guile Reference Manual}). The value of these arguments is usually
6594 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
6595 by the daemon (@pxref{Derivations}).
6597 The main build system is @code{gnu-build-system}, which implements the
6598 standard build procedure for GNU and many other packages. It
6599 is provided by the @code{(guix build-system gnu)} module.
6601 @defvr {Scheme Variable} gnu-build-system
6602 @code{gnu-build-system} represents the GNU Build System, and variants
6603 thereof (@pxref{Configuration, configuration and makefile conventions,,
6604 standards, GNU Coding Standards}).
6606 @cindex build phases
6607 In a nutshell, packages using it are configured, built, and installed with
6608 the usual @code{./configure && make && make check && make install}
6609 command sequence. In practice, a few additional steps are often needed.
6610 All these steps are split up in separate @dfn{phases},
6611 notably@footnote{Please see the @code{(guix build gnu-build-system)}
6612 modules for more details about the build phases.}:
6616 Unpack the source tarball, and change the current directory to the
6617 extracted source tree. If the source is actually a directory, copy it
6618 to the build tree, and enter that directory.
6620 @item patch-source-shebangs
6621 Patch shebangs encountered in source files so they refer to the right
6622 store file names. For instance, this changes @code{#!/bin/sh} to
6623 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
6626 Run the @file{configure} script with a number of default options, such
6627 as @option{--prefix=/gnu/store/@dots{}}, as well as the options specified
6628 by the @code{#:configure-flags} argument.
6631 Run @code{make} with the list of flags specified with
6632 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
6633 (the default), build with @code{make -j}.
6636 Run @code{make check}, or some other target specified with
6637 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
6638 @code{#:parallel-tests?} argument is true (the default), run @code{make
6642 Run @code{make install} with the flags listed in @code{#:make-flags}.
6644 @item patch-shebangs
6645 Patch shebangs on the installed executable files.
6648 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
6649 is false), copying them to the @code{debug} output when available
6650 (@pxref{Installing Debugging Files}).
6653 @vindex %standard-phases
6654 The build-side module @code{(guix build gnu-build-system)} defines
6655 @code{%standard-phases} as the default list of build phases.
6656 @code{%standard-phases} is a list of symbol/procedure pairs, where the
6657 procedure implements the actual phase.
6659 The list of phases used for a particular package can be changed with the
6660 @code{#:phases} parameter. For instance, passing:
6663 #:phases (modify-phases %standard-phases (delete 'configure))
6666 means that all the phases described above will be used, except the
6667 @code{configure} phase.
6669 In addition, this build system ensures that the ``standard'' environment
6670 for GNU packages is available. This includes tools such as GCC, libc,
6671 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
6672 build-system gnu)} module for a complete list). We call these the
6673 @dfn{implicit inputs} of a package, because package definitions do not
6674 have to mention them.
6677 Other @code{<build-system>} objects are defined to support other
6678 conventions and tools used by free software packages. They inherit most
6679 of @code{gnu-build-system}, and differ mainly in the set of inputs
6680 implicitly added to the build process, and in the list of phases
6681 executed. Some of these build systems are listed below.
6683 @defvr {Scheme Variable} ant-build-system
6684 This variable is exported by @code{(guix build-system ant)}. It
6685 implements the build procedure for Java packages that can be built with
6686 @url{https://ant.apache.org/, Ant build tool}.
6688 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
6689 provided by the @code{icedtea} package to the set of inputs. Different
6690 packages can be specified with the @code{#:ant} and @code{#:jdk}
6691 parameters, respectively.
6693 When the original package does not provide a suitable Ant build file,
6694 the parameter @code{#:jar-name} can be used to generate a minimal Ant
6695 build file @file{build.xml} with tasks to build the specified jar
6696 archive. In this case the parameter @code{#:source-dir} can be used to
6697 specify the source sub-directory, defaulting to ``src''.
6699 The @code{#:main-class} parameter can be used with the minimal ant
6700 buildfile to specify the main class of the resulting jar. This makes the
6701 jar file executable. The @code{#:test-include} parameter can be used to
6702 specify the list of junit tests to run. It defaults to
6703 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
6704 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
6705 because abstract classes cannot be run as tests.
6707 The parameter @code{#:build-target} can be used to specify the Ant task
6708 that should be run during the @code{build} phase. By default the
6709 ``jar'' task will be run.
6713 @defvr {Scheme Variable} android-ndk-build-system
6714 @cindex Android distribution
6715 @cindex Android NDK build system
6716 This variable is exported by @code{(guix build-system android-ndk)}. It
6717 implements a build procedure for Android NDK (native development kit)
6718 packages using a Guix-specific build process.
6720 The build system assumes that packages install their public interface
6721 (header) files to the subdirectory @file{include} of the @code{out} output and
6722 their libraries to the subdirectory @file{lib} the @code{out} output.
6724 It's also assumed that the union of all the dependencies of a package
6725 has no conflicting files.
6727 For the time being, cross-compilation is not supported - so right now
6728 the libraries and header files are assumed to be host tools.
6732 @defvr {Scheme Variable} asdf-build-system/source
6733 @defvrx {Scheme Variable} asdf-build-system/sbcl
6734 @defvrx {Scheme Variable} asdf-build-system/ecl
6736 These variables, exported by @code{(guix build-system asdf)}, implement
6737 build procedures for Common Lisp packages using
6738 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
6739 definition facility for Common Lisp programs and libraries.
6741 The @code{asdf-build-system/source} system installs the packages in
6742 source form, and can be loaded using any common lisp implementation, via
6743 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
6744 systems in the format which a particular implementation understands.
6745 These build systems can also be used to produce executable programs, or
6746 lisp images which contain a set of packages pre-loaded.
6748 The build system uses naming conventions. For binary packages, the
6749 package name should be prefixed with the lisp implementation, such as
6750 @code{sbcl-} for @code{asdf-build-system/sbcl}.
6752 Additionally, the corresponding source package should be labeled using
6753 the same convention as python packages (see @ref{Python Modules}), using
6754 the @code{cl-} prefix.
6756 For binary packages, each system should be defined as a Guix package.
6757 If one package @code{origin} contains several systems, package variants
6758 can be created in order to build all the systems. Source packages,
6759 which use @code{asdf-build-system/source}, may contain several systems.
6761 In order to create executable programs and images, the build-side
6762 procedures @code{build-program} and @code{build-image} can be used.
6763 They should be called in a build phase after the @code{create-symlinks}
6764 phase, so that the system which was just built can be used within the
6765 resulting image. @code{build-program} requires a list of Common Lisp
6766 expressions to be passed as the @code{#:entry-program} argument.
6768 If the system is not defined within its own @file{.asd} file of the same
6769 name, then the @code{#:asd-file} parameter should be used to specify
6770 which file the system is defined in. Furthermore, if the package
6771 defines a system for its tests in a separate file, it will be loaded
6772 before the tests are run if it is specified by the
6773 @code{#:test-asd-file} parameter. If it is not set, the files
6774 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
6775 and @code{test.asd} will be tried if they exist.
6777 If for some reason the package must be named in a different way than the
6778 naming conventions suggest, the @code{#:asd-system-name} parameter can
6779 be used to specify the name of the system.
6783 @defvr {Scheme Variable} cargo-build-system
6784 @cindex Rust programming language
6785 @cindex Cargo (Rust build system)
6786 This variable is exported by @code{(guix build-system cargo)}. It
6787 supports builds of packages using Cargo, the build tool of the
6788 @uref{https://www.rust-lang.org, Rust programming language}.
6790 It adds @code{rustc} and @code{cargo} to the set of inputs.
6791 A different Rust package can be specified with the @code{#:rust} parameter.
6793 Regular cargo dependencies should be added to the package definition via the
6794 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
6795 spec can be a package or a source definition. Note that the spec must
6796 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
6797 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
6798 should be added to the package definition via the
6799 @code{#:cargo-development-inputs} parameter.
6801 In its @code{configure} phase, this build system will make any source inputs
6802 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
6803 parameters available to cargo. It will also remove an included
6804 @code{Cargo.lock} file to be recreated by @code{cargo} during the
6805 @code{build} phase. The @code{install} phase installs any crate the binaries
6806 if they are defined by the crate.
6810 @defvr {Scheme Variable} copy-build-system
6811 This variable is exported by @code{(guix build-system copy)}. It
6812 supports builds of simple packages that don't require much compiling,
6813 mostly just moving files around.
6815 It adds much of the @code{gnu-build-system} packages to the set of
6816 inputs. Because of this, the @code{copy-build-system} does not require
6817 all the boilerplate code often needed for the
6818 @code{trivial-build-system}.
6820 To further simplify the file installation process, an
6821 @code{#:install-plan} argument is exposed to let the packager specify
6822 which files go where. The install plan is a list of @code{(@var{source}
6823 @var{target} [@var{filters}])}. @var{filters} are optional.
6826 @item When @var{source} matches a file or directory without trailing slash, install it to @var{target}.
6828 @item If @var{target} has a trailing slash, install @var{source} basename beneath @var{target}.
6829 @item Otherwise install @var{source} as @var{target}.
6832 @item When @var{source} is a directory with a trailing slash, or when @var{filters} are used,
6833 the trailing slash of @var{target} is implied with the same meaning
6836 @item Without @var{filters}, install the full @var{source} @emph{content} to @var{target}.
6837 @item With @var{filters} among @code{#:include}, @code{#:include-regexp}, @code{#:exclude},
6838 @code{#:exclude-regexp}, only select files are installed depending on
6839 the filters. Each filters is specified by a list of strings.
6841 @item With @code{#:include}, install all the files which the path suffix matches
6842 at least one of the elements in the given list.
6843 @item With @code{#:include-regexp}, install all the files which the
6844 subpaths match at least one of the regular expressions in the given
6846 @item The @code{#:exclude} and @code{#:exclude-regexp} filters
6847 are the complement of their inclusion counterpart. Without @code{#:include} flags,
6848 install all files but those matching the exclusion filters.
6849 If both inclusions and exclusions are specified, the exclusions are done
6850 on top of the inclusions.
6853 In all cases, the paths relative to @var{source} are preserved within
6860 @item @code{("foo/bar" "share/my-app/")}: Install @file{bar} to @file{share/my-app/bar}.
6861 @item @code{("foo/bar" "share/my-app/baz")}: Install @file{bar} to @file{share/my-app/baz}.
6862 @item @code{("foo/" "share/my-app")}: Install the content of @file{foo} inside @file{share/my-app},
6863 e.g., install @file{foo/sub/file} to @file{share/my-app/sub/file}.
6864 @item @code{("foo/" "share/my-app" #:include ("sub/file"))}: Install only @file{foo/sub/file} to
6865 @file{share/my-app/sub/file}.
6866 @item @code{("foo/sub" "share/my-app" #:include ("file"))}: Install @file{foo/sub/file} to
6867 @file{share/my-app/file}.
6872 @cindex Clojure (programming language)
6873 @cindex simple Clojure build system
6874 @defvr {Scheme Variable} clojure-build-system
6875 This variable is exported by @code{(guix build-system clojure)}. It implements
6876 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
6877 using plain old @code{compile} in Clojure. Cross-compilation is not supported
6880 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
6881 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
6882 @code{#:zip} parameters, respectively.
6884 A list of source directories, test directories and jar names can be specified
6885 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
6886 parameters, respectively. Compile directory and main class can be specified
6887 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
6888 Other parameters are documented below.
6890 This build system is an extension of @code{ant-build-system}, but with the
6891 following phases changed:
6896 This phase calls @code{compile} in Clojure to compile source files and runs
6897 @command{jar} to create jars from both source files and compiled files
6898 according to the include list and exclude list specified in
6899 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
6900 has priority over the include list. These lists consist of symbols
6901 representing Clojure libraries or the special keyword @code{#:all} representing
6902 all Clojure libraries found under the source directories. The parameter
6903 @code{#:omit-source?} decides if source should be included into the jars.
6906 This phase runs tests according to the include list and exclude list specified
6907 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
6908 meanings are analogous to that of @code{#:aot-include} and
6909 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
6910 stands for all Clojure libraries found under the test directories. The
6911 parameter @code{#:tests?} decides if tests should be run.
6914 This phase installs all jars built previously.
6917 Apart from the above, this build system also contains an additional phase:
6922 This phase installs all top-level files with base name matching
6923 @code{%doc-regex}. A different regex can be specified with the
6924 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
6925 directories specified in @code{#:doc-dirs} are installed as well.
6929 @defvr {Scheme Variable} cmake-build-system
6930 This variable is exported by @code{(guix build-system cmake)}. It
6931 implements the build procedure for packages using the
6932 @url{https://www.cmake.org, CMake build tool}.
6934 It automatically adds the @code{cmake} package to the set of inputs.
6935 Which package is used can be specified with the @code{#:cmake}
6938 The @code{#:configure-flags} parameter is taken as a list of flags
6939 passed to the @command{cmake} command. The @code{#:build-type}
6940 parameter specifies in abstract terms the flags passed to the compiler;
6941 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
6942 debugging information''), which roughly means that code is compiled with
6943 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
6946 @defvr {Scheme Variable} dune-build-system
6947 This variable is exported by @code{(guix build-system dune)}. It
6948 supports builds of packages using @uref{https://dune.build/, Dune}, a build
6949 tool for the OCaml programming language. It is implemented as an extension
6950 of the @code{ocaml-build-system} which is described below. As such, the
6951 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
6954 It automatically adds the @code{dune} package to the set of inputs.
6955 Which package is used can be specified with the @code{#:dune}
6958 There is no @code{configure} phase because dune packages typically don't
6959 need to be configured. The @code{#:build-flags} parameter is taken as a
6960 list of flags passed to the @code{dune} command during the build.
6962 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
6963 command instead of the more recent @code{dune} command while building
6964 a package. Its default value is @code{#f}.
6966 The @code{#:package} parameter can be passed to specify a package name, which
6967 is useful when a package contains multiple packages and you want to build
6968 only one of them. This is equivalent to passing the @code{-p} argument to
6972 @defvr {Scheme Variable} go-build-system
6973 This variable is exported by @code{(guix build-system go)}. It
6974 implements a build procedure for Go packages using the standard
6975 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
6976 Go build mechanisms}.
6978 The user is expected to provide a value for the key @code{#:import-path}
6979 and, in some cases, @code{#:unpack-path}. The
6980 @url{https://golang.org/doc/code.html#ImportPaths, import path}
6981 corresponds to the file system path expected by the package's build
6982 scripts and any referring packages, and provides a unique way to
6983 refer to a Go package. It is typically based on a combination of the
6984 package source code's remote URI and file system hierarchy structure. In
6985 some cases, you will need to unpack the package's source code to a
6986 different directory structure than the one indicated by the import path,
6987 and @code{#:unpack-path} should be used in such cases.
6989 Packages that provide Go libraries should install their source code into
6990 the built output. The key @code{#:install-source?}, which defaults to
6991 @code{#t}, controls whether or not the source code is installed. It can
6992 be set to @code{#f} for packages that only provide executable files.
6995 @defvr {Scheme Variable} glib-or-gtk-build-system
6996 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
6997 is intended for use with packages making use of GLib or GTK+.
6999 This build system adds the following two phases to the ones defined by
7000 @code{gnu-build-system}:
7003 @item glib-or-gtk-wrap
7004 The phase @code{glib-or-gtk-wrap} ensures that programs in
7005 @file{bin/} are able to find GLib ``schemas'' and
7006 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
7007 modules}. This is achieved by wrapping the programs in launch scripts
7008 that appropriately set the @env{XDG_DATA_DIRS} and @env{GTK_PATH}
7009 environment variables.
7011 It is possible to exclude specific package outputs from that wrapping
7012 process by listing their names in the
7013 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
7014 when an output is known not to contain any GLib or GTK+ binaries, and
7015 where wrapping would gratuitously add a dependency of that output on
7018 @item glib-or-gtk-compile-schemas
7019 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
7020 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
7021 GSettings schemas} of GLib are compiled. Compilation is performed by the
7022 @command{glib-compile-schemas} program. It is provided by the package
7023 @code{glib:bin} which is automatically imported by the build system.
7024 The @code{glib} package providing @command{glib-compile-schemas} can be
7025 specified with the @code{#:glib} parameter.
7028 Both phases are executed after the @code{install} phase.
7031 @defvr {Scheme Variable} guile-build-system
7032 This build system is for Guile packages that consist exclusively of Scheme
7033 code and that are so lean that they don't even have a makefile, let alone a
7034 @file{configure} script. It compiles Scheme code using @command{guild
7035 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
7036 installs the @file{.scm} and @file{.go} files in the right place. It also
7037 installs documentation.
7039 This build system supports cross-compilation by using the
7040 @option{--target} option of @samp{guild compile}.
7042 Packages built with @code{guile-build-system} must provide a Guile package in
7043 their @code{native-inputs} field.
7046 @defvr {Scheme Variable} julia-build-system
7047 This variable is exported by @code{(guix build-system julia)}. It
7048 implements the build procedure used by @uref{https://julialang.org/,
7049 julia} packages, which essentially is similar to running @samp{julia -e
7050 'using Pkg; Pkg.add(package)'} in an environment where
7051 @env{JULIA_LOAD_PATH} contains the paths to all Julia package inputs.
7052 Tests are run not run.
7054 Julia packages require the source @code{file-name} to be the real name of the
7055 package, correctly capitalized.
7057 For packages requiring shared library dependencies, you may need to write the
7058 @file{/deps/deps.jl} file manually. It's usually a line of @code{const
7059 variable = /gnu/store/library.so} for each dependency, plus a void function
7060 @code{check_deps() = nothing}.
7062 Some older packages that aren't using @file{Package.toml} yet, will require
7063 this file to be created, too. The function @code{julia-create-package-toml}
7064 helps creating the file. You need to pass the outputs and the source of the
7065 package, it's name (the same as the @code{file-name} parameter), the package
7066 uuid, the package version, and a list of dependencies specified by their name
7070 @defvr {Scheme Variable} maven-build-system
7071 This variable is exported by @code{(guix build-system maven)}. It implements
7072 a build procedure for @uref{https://maven.apache.org, Maven} packages. Maven
7073 is a dependency and lifecycle management tool for Java. A user of Maven
7074 specifies dependencies and plugins in a @file{pom.xml} file that Maven reads.
7075 When Maven does not have one of the dependencies or plugins in its repository,
7076 it will download them and use them to build the package.
7078 The maven build system ensures that maven will not try to download any
7079 dependency by running in offline mode. Maven will fail if a dependency is
7080 missing. Before running Maven, the @file{pom.xml} (and subprojects) are
7081 modified to specify the version of dependencies and plugins that match the
7082 versions available in the guix build environment. Dependencies and plugins
7083 must be installed in the fake maven repository at @file{lib/m2}, and are
7084 symlinked into a proper repository before maven is run. Maven is instructed
7085 to use that repository for the build and installs built artifacts there.
7086 Changed files are copied to the @file{lib/m2} directory of the package output.
7088 You can specify a @file{pom.xml} file with the @code{#:pom-file} argument,
7089 or let the build system use the default @file{pom.xml} file in the sources.
7091 In case you need to specify a dependency's version manually, you can use the
7092 @code{#:local-packages} argument. It takes an association list where the key
7093 is the groupId of the package and its value is an association list where the
7094 key is the artifactId of the package and its value is the version you want to
7095 override in the @file{pom.xml}.
7097 Some packages use dependencies or plugins that are not useful at runtime nor
7098 at build time in Guix. You can alter the @file{pom.xml} file to remove them
7099 using the @code{#:exclude} argument. Its value is an association list where
7100 the key is the groupId of the plugin or dependency you want to remove, and
7101 the value is a list of artifactId you want to remove.
7103 You can override the default @code{jdk} and @code{maven} packages with the
7104 corresponding argument, @code{#:jdk} and @code{#:maven}.
7106 The @code{#:maven-plugins} argument is a list of maven plugins used during
7107 the build, with the same format as the @code{inputs} fields of the package
7108 declaration. Its default value is @code{(default-maven-plugins)} which is
7112 @defvr {Scheme Variable} minify-build-system
7113 This variable is exported by @code{(guix build-system minify)}. It
7114 implements a minification procedure for simple JavaScript packages.
7116 It adds @code{uglify-js} to the set of inputs and uses it to compress
7117 all JavaScript files in the @file{src} directory. A different minifier
7118 package can be specified with the @code{#:uglify-js} parameter, but it
7119 is expected that the package writes the minified code to the standard
7122 When the input JavaScript files are not all located in the @file{src}
7123 directory, the parameter @code{#:javascript-files} can be used to
7124 specify a list of file names to feed to the minifier.
7127 @defvr {Scheme Variable} ocaml-build-system
7128 This variable is exported by @code{(guix build-system ocaml)}. It implements
7129 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
7130 of choosing the correct set of commands to run for each package. OCaml
7131 packages can expect many different commands to be run. This build system will
7134 When the package has a @file{setup.ml} file present at the top-level, it will
7135 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
7136 @code{ocaml setup.ml -install}. The build system will assume that this file
7137 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
7138 care of setting the prefix and enabling tests if they are not disabled. You
7139 can pass configure and build flags with the @code{#:configure-flags} and
7140 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
7141 set of flags used to enable tests. The @code{#:use-make?} key can be used to
7142 bypass this system in the build and install phases.
7144 When the package has a @file{configure} file, it is assumed that it is a
7145 hand-made configure script that requires a different argument format than
7146 in the @code{gnu-build-system}. You can add more flags with the
7147 @code{#:configure-flags} key.
7149 When the package has a @file{Makefile} file (or @code{#:use-make?} is
7150 @code{#t}), it will be used and more flags can be passed to the build and
7151 install phases with the @code{#:make-flags} key.
7153 Finally, some packages do not have these files and use a somewhat standard
7154 location for its build system. In that case, the build system will run
7155 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
7156 providing the path to the required findlib module. Additional flags can
7157 be passed via the @code{#:build-flags} key. Install is taken care of by
7158 @command{opam-installer}. In this case, the @code{opam} package must
7159 be added to the @code{native-inputs} field of the package definition.
7161 Note that most OCaml packages assume they will be installed in the same
7162 directory as OCaml, which is not what we want in guix. In particular, they
7163 will install @file{.so} files in their module's directory, which is usually
7164 fine because it is in the OCaml compiler directory. In guix though, these
7165 libraries cannot be found and we use @env{CAML_LD_LIBRARY_PATH}. This
7166 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
7167 @file{.so} libraries should be installed.
7170 @defvr {Scheme Variable} python-build-system
7171 This variable is exported by @code{(guix build-system python)}. It
7172 implements the more or less standard build procedure used by Python
7173 packages, which consists in running @code{python setup.py build} and
7174 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
7176 For packages that install stand-alone Python programs under @code{bin/},
7177 it takes care of wrapping these programs so that their @env{PYTHONPATH}
7178 environment variable points to all the Python libraries they depend on.
7180 Which Python package is used to perform the build can be specified with
7181 the @code{#:python} parameter. This is a useful way to force a package
7182 to be built for a specific version of the Python interpreter, which
7183 might be necessary if the package is only compatible with a single
7184 interpreter version.
7186 By default guix calls @code{setup.py} under control of
7187 @code{setuptools}, much like @command{pip} does. Some packages are not
7188 compatible with setuptools (and pip), thus you can disable this by
7189 setting the @code{#:use-setuptools?} parameter to @code{#f}.
7192 @defvr {Scheme Variable} perl-build-system
7193 This variable is exported by @code{(guix build-system perl)}. It
7194 implements the standard build procedure for Perl packages, which either
7195 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
7196 followed by @code{Build} and @code{Build install}; or in running
7197 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
7198 @code{make} and @code{make install}, depending on which of
7199 @code{Build.PL} or @code{Makefile.PL} is present in the package
7200 distribution. Preference is given to the former if both @code{Build.PL}
7201 and @code{Makefile.PL} exist in the package distribution. This
7202 preference can be reversed by specifying @code{#t} for the
7203 @code{#:make-maker?} parameter.
7205 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
7206 passes flags specified by the @code{#:make-maker-flags} or
7207 @code{#:module-build-flags} parameter, respectively.
7209 Which Perl package is used can be specified with @code{#:perl}.
7212 @defvr {Scheme Variable} qt-build-system
7213 This variable is exported by @code{(guix build-system qt)}. It
7214 is intended for use with applications using Qt or KDE.
7216 This build system adds the following two phases to the ones defined by
7217 @code{cmake-build-system}:
7221 The phase @code{check-setup} prepares the environment for running
7222 the checks as commonly used by Qt test programs.
7223 For now this only sets some environment variables:
7224 @code{QT_QPA_PLATFORM=offscreen},
7225 @code{DBUS_FATAL_WARNINGS=0} and
7226 @code{CTEST_OUTPUT_ON_FAILURE=1}.
7228 This phase is added before the @code{check} phase.
7229 It's a separate phase to ease adjusting if necessary.
7232 The phase @code{qt-wrap}
7233 searches for Qt5 plugin paths, QML paths and some XDG in the inputs
7234 and output. In case some path is found, all programs in the output's
7235 @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
7236 are wrapped in scripts defining the necessary environment variables.
7238 It is possible to exclude specific package outputs from that wrapping process
7239 by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
7240 This is useful when an output is known not to contain any Qt binaries, and
7241 where wrapping would gratuitously add a dependency of that output on Qt, KDE,
7244 This phase is added after the @code{install} phase.
7248 @defvr {Scheme Variable} r-build-system
7249 This variable is exported by @code{(guix build-system r)}. It
7250 implements the build procedure used by @uref{https://r-project.org, R}
7251 packages, which essentially is little more than running @samp{R CMD
7252 INSTALL --library=/gnu/store/@dots{}} in an environment where
7253 @env{R_LIBS_SITE} contains the paths to all R package inputs. Tests are
7254 run after installation using the R function
7255 @code{tools::testInstalledPackage}.
7258 @defvr {Scheme Variable} rakudo-build-system
7259 This variable is exported by @code{(guix build-system rakudo)}. It
7260 implements the build procedure used by @uref{https://rakudo.org/,
7261 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
7262 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
7263 installs the binaries, library files and the resources, as well as wrap
7264 the files under the @code{bin/} directory. Tests can be skipped by
7265 passing @code{#f} to the @code{tests?} parameter.
7267 Which rakudo package is used can be specified with @code{rakudo}.
7268 Which perl6-tap-harness package used for the tests can be specified with
7269 @code{#:prove6} or removed by passing @code{#f} to the
7270 @code{with-prove6?} parameter.
7271 Which perl6-zef package used for tests and installing can be specified
7272 with @code{#:zef} or removed by passing @code{#f} to the
7273 @code{with-zef?} parameter.
7276 @defvr {Scheme Variable} texlive-build-system
7277 This variable is exported by @code{(guix build-system texlive)}. It is
7278 used to build TeX packages in batch mode with a specified engine. The
7279 build system sets the @env{TEXINPUTS} variable to find all TeX source
7280 files in the inputs.
7282 By default it runs @code{luatex} on all files ending on @code{ins}. A
7283 different engine and format can be specified with the
7284 @code{#:tex-format} argument. Different build targets can be specified
7285 with the @code{#:build-targets} argument, which expects a list of file
7286 names. The build system adds only @code{texlive-bin} and
7287 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
7288 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
7289 and @code{#:texlive-latex-base}, respectively.
7291 The @code{#:tex-directory} parameter tells the build system where to
7292 install the built files under the texmf tree.
7295 @defvr {Scheme Variable} ruby-build-system
7296 This variable is exported by @code{(guix build-system ruby)}. It
7297 implements the RubyGems build procedure used by Ruby packages, which
7298 involves running @code{gem build} followed by @code{gem install}.
7300 The @code{source} field of a package that uses this build system
7301 typically references a gem archive, since this is the format that Ruby
7302 developers use when releasing their software. The build system unpacks
7303 the gem archive, potentially patches the source, runs the test suite,
7304 repackages the gem, and installs it. Additionally, directories and
7305 tarballs may be referenced to allow building unreleased gems from Git or
7306 a traditional source release tarball.
7308 Which Ruby package is used can be specified with the @code{#:ruby}
7309 parameter. A list of additional flags to be passed to the @command{gem}
7310 command can be specified with the @code{#:gem-flags} parameter.
7313 @defvr {Scheme Variable} waf-build-system
7314 This variable is exported by @code{(guix build-system waf)}. It
7315 implements a build procedure around the @code{waf} script. The common
7316 phases---@code{configure}, @code{build}, and @code{install}---are
7317 implemented by passing their names as arguments to the @code{waf}
7320 The @code{waf} script is executed by the Python interpreter. Which
7321 Python package is used to run the script can be specified with the
7322 @code{#:python} parameter.
7325 @defvr {Scheme Variable} scons-build-system
7326 This variable is exported by @code{(guix build-system scons)}. It
7327 implements the build procedure used by the SCons software construction
7328 tool. This build system runs @code{scons} to build the package,
7329 @code{scons test} to run tests, and then @code{scons install} to install
7332 Additional flags to be passed to @code{scons} can be specified with the
7333 @code{#:scons-flags} parameter. The default build and install targets
7334 can be overridden with @code{#:build-targets} and
7335 @code{#:install-targets} respectively. The version of Python used to
7336 run SCons can be specified by selecting the appropriate SCons package
7337 with the @code{#:scons} parameter.
7340 @defvr {Scheme Variable} haskell-build-system
7341 This variable is exported by @code{(guix build-system haskell)}. It
7342 implements the Cabal build procedure used by Haskell packages, which
7343 involves running @code{runhaskell Setup.hs configure
7344 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
7345 Instead of installing the package by running @code{runhaskell Setup.hs
7346 install}, to avoid trying to register libraries in the read-only
7347 compiler store directory, the build system uses @code{runhaskell
7348 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
7349 addition, the build system generates the package documentation by
7350 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
7351 is passed. Optional Haddock parameters can be passed with the help of
7352 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
7353 not found, the build system looks for @code{Setup.lhs} instead.
7355 Which Haskell compiler is used can be specified with the @code{#:haskell}
7356 parameter which defaults to @code{ghc}.
7359 @defvr {Scheme Variable} dub-build-system
7360 This variable is exported by @code{(guix build-system dub)}. It
7361 implements the Dub build procedure used by D packages, which
7362 involves running @code{dub build} and @code{dub run}.
7363 Installation is done by copying the files manually.
7365 Which D compiler is used can be specified with the @code{#:ldc}
7366 parameter which defaults to @code{ldc}.
7369 @defvr {Scheme Variable} emacs-build-system
7370 This variable is exported by @code{(guix build-system emacs)}. It
7371 implements an installation procedure similar to the packaging system
7372 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
7374 It first creates the @code{@code{package}-autoloads.el} file, then it
7375 byte compiles all Emacs Lisp files. Differently from the Emacs
7376 packaging system, the Info documentation files are moved to the standard
7377 documentation directory and the @file{dir} file is deleted. The Elisp
7378 package files are installed directly under @file{share/emacs/site-lisp}.
7381 @defvr {Scheme Variable} font-build-system
7382 This variable is exported by @code{(guix build-system font)}. It
7383 implements an installation procedure for font packages where upstream
7384 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
7385 need to be copied into place. It copies font files to standard
7386 locations in the output directory.
7389 @defvr {Scheme Variable} meson-build-system
7390 This variable is exported by @code{(guix build-system meson)}. It
7391 implements the build procedure for packages that use
7392 @url{https://mesonbuild.com, Meson} as their build system.
7394 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
7395 of inputs, and they can be changed with the parameters @code{#:meson}
7396 and @code{#:ninja} if needed. The default Meson is
7397 @code{meson-for-build}, which is special because it doesn't clear the
7398 @code{RUNPATH} of binaries and libraries when they are installed.
7400 This build system is an extension of @code{gnu-build-system}, but with the
7401 following phases changed to some specific for Meson:
7406 The phase runs @code{meson} with the flags specified in
7407 @code{#:configure-flags}. The flag @option{--buildtype} is always set to
7408 @code{debugoptimized} unless something else is specified in
7409 @code{#:build-type}.
7412 The phase runs @code{ninja} to build the package in parallel by default, but
7413 this can be changed with @code{#:parallel-build?}.
7416 The phase runs @code{ninja} with the target specified in @code{#:test-target},
7417 which is @code{"test"} by default.
7420 The phase runs @code{ninja install} and can not be changed.
7423 Apart from that, the build system also adds the following phases:
7428 This phase ensures that all binaries can find the libraries they need.
7429 It searches for required libraries in subdirectories of the package being
7430 built, and adds those to @code{RUNPATH} where needed. It also removes
7431 references to libraries left over from the build phase by
7432 @code{meson-for-build}, such as test dependencies, that aren't actually
7433 required for the program to run.
7435 @item glib-or-gtk-wrap
7436 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
7437 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
7439 @item glib-or-gtk-compile-schemas
7440 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
7441 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
7445 @defvr {Scheme Variable} linux-module-build-system
7446 @code{linux-module-build-system} allows building Linux kernel modules.
7448 @cindex build phases
7449 This build system is an extension of @code{gnu-build-system}, but with the
7450 following phases changed:
7455 This phase configures the environment so that the Linux kernel's Makefile
7456 can be used to build the external kernel module.
7459 This phase uses the Linux kernel's Makefile in order to build the external
7463 This phase uses the Linux kernel's Makefile in order to install the external
7467 It is possible and useful to specify the Linux kernel to use for building
7468 the module (in the @code{arguments} form of a package using the
7469 @code{linux-module-build-system}, use the key @code{#:linux} to specify it).
7472 @defvr {Scheme Variable} node-build-system
7473 This variable is exported by @code{(guix build-system node)}. It
7474 implements the build procedure used by @uref{https://nodejs.org,
7475 Node.js}, which implements an approximation of the @code{npm install}
7476 command, followed by an @code{npm test} command.
7478 Which Node.js package is used to interpret the @code{npm} commands can
7479 be specified with the @code{#:node} parameter which defaults to
7483 Lastly, for packages that do not need anything as sophisticated, a
7484 ``trivial'' build system is provided. It is trivial in the sense that
7485 it provides basically no support: it does not pull any implicit inputs,
7486 and does not have a notion of build phases.
7488 @defvr {Scheme Variable} trivial-build-system
7489 This variable is exported by @code{(guix build-system trivial)}.
7491 This build system requires a @code{#:builder} argument. This argument
7492 must be a Scheme expression that builds the package output(s)---as
7493 with @code{build-expression->derivation} (@pxref{Derivations,
7494 @code{build-expression->derivation}}).
7504 Conceptually, the @dfn{store} is the place where derivations that have
7505 been built successfully are stored---by default, @file{/gnu/store}.
7506 Sub-directories in the store are referred to as @dfn{store items} or
7507 sometimes @dfn{store paths}. The store has an associated database that
7508 contains information such as the store paths referred to by each store
7509 path, and the list of @emph{valid} store items---results of successful
7510 builds. This database resides in @file{@var{localstatedir}/guix/db},
7511 where @var{localstatedir} is the state directory specified @i{via}
7512 @option{--localstatedir} at configure time, usually @file{/var}.
7514 The store is @emph{always} accessed by the daemon on behalf of its clients
7515 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
7516 connect to the daemon over a Unix-domain socket, send requests to it,
7517 and read the result---these are remote procedure calls, or RPCs.
7520 Users must @emph{never} modify files under @file{/gnu/store} directly.
7521 This would lead to inconsistencies and break the immutability
7522 assumptions of Guix's functional model (@pxref{Introduction}).
7524 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
7525 how to check the integrity of the store and attempt recovery from
7526 accidental modifications.
7529 The @code{(guix store)} module provides procedures to connect to the
7530 daemon, and to perform RPCs. These are described below. By default,
7531 @code{open-connection}, and thus all the @command{guix} commands,
7532 connect to the local daemon or to the URI specified by the
7533 @env{GUIX_DAEMON_SOCKET} environment variable.
7535 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
7536 When set, the value of this variable should be a file name or a URI
7537 designating the daemon endpoint. When it is a file name, it denotes a
7538 Unix-domain socket to connect to. In addition to file names, the
7539 supported URI schemes are:
7544 These are for Unix-domain sockets.
7545 @code{file:///var/guix/daemon-socket/socket} is equivalent to
7546 @file{/var/guix/daemon-socket/socket}.
7549 @cindex daemon, remote access
7550 @cindex remote access to the daemon
7551 @cindex daemon, cluster setup
7552 @cindex clusters, daemon setup
7553 These URIs denote connections over TCP/IP, without encryption nor
7554 authentication of the remote host. The URI must specify the host name
7555 and optionally a port number (by default port 44146 is used):
7558 guix://master.guix.example.org:1234
7561 This setup is suitable on local networks, such as clusters, where only
7562 trusted nodes may connect to the build daemon at
7563 @code{master.guix.example.org}.
7565 The @option{--listen} option of @command{guix-daemon} can be used to
7566 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
7567 @option{--listen}}).
7570 @cindex SSH access to build daemons
7571 These URIs allow you to connect to a remote daemon over SSH. This
7572 feature requires Guile-SSH (@pxref{Requirements}) and a working
7573 @command{guile} binary in @env{PATH} on the destination machine. It
7574 supports public key and GSSAPI authentication. A typical URL might look
7578 ssh://charlie@@guix.example.org:22
7581 As for @command{guix copy}, the usual OpenSSH client configuration files
7582 are honored (@pxref{Invoking guix copy}).
7585 Additional URI schemes may be supported in the future.
7587 @c XXX: Remove this note when the protocol incurs fewer round trips
7588 @c and when (guix derivations) no longer relies on file system access.
7590 The ability to connect to remote build daemons is considered
7591 experimental as of @value{VERSION}. Please get in touch with us to
7592 share any problems or suggestions you may have (@pxref{Contributing}).
7596 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
7597 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
7598 @var{reserve-space?} is true, instruct it to reserve a little bit of
7599 extra space on the file system so that the garbage collector can still
7600 operate should the disk become full. Return a server object.
7602 @var{file} defaults to @code{%default-socket-path}, which is the normal
7603 location given the options that were passed to @command{configure}.
7606 @deffn {Scheme Procedure} close-connection @var{server}
7607 Close the connection to @var{server}.
7610 @defvr {Scheme Variable} current-build-output-port
7611 This variable is bound to a SRFI-39 parameter, which refers to the port
7612 where build and error logs sent by the daemon should be written.
7615 Procedures that make RPCs all take a server object as their first
7618 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
7619 @cindex invalid store items
7620 Return @code{#t} when @var{path} designates a valid store item and
7621 @code{#f} otherwise (an invalid item may exist on disk but still be
7622 invalid, for instance because it is the result of an aborted or failed
7625 A @code{&store-protocol-error} condition is raised if @var{path} is not
7626 prefixed by the store directory (@file{/gnu/store}).
7629 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
7630 Add @var{text} under file @var{name} in the store, and return its store
7631 path. @var{references} is the list of store paths referred to by the
7632 resulting store path.
7635 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
7637 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
7638 file names, or derivation/output pairs, using the specified
7639 @var{mode}---@code{(build-mode normal)} by default.
7642 Note that the @code{(guix monads)} module provides a monad as well as
7643 monadic versions of the above procedures, with the goal of making it
7644 more convenient to work with code that accesses the store (@pxref{The
7648 @i{This section is currently incomplete.}
7651 @section Derivations
7654 Low-level build actions and the environment in which they are performed
7655 are represented by @dfn{derivations}. A derivation contains the
7656 following pieces of information:
7660 The outputs of the derivation---derivations produce at least one file or
7661 directory in the store, but may produce more.
7664 @cindex build-time dependencies
7665 @cindex dependencies, build-time
7666 The inputs of the derivations---i.e., its build-time dependencies---which may
7667 be other derivations or plain files in the store (patches, build scripts,
7671 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
7674 The file name of a build script in the store, along with the arguments
7678 A list of environment variables to be defined.
7682 @cindex derivation path
7683 Derivations allow clients of the daemon to communicate build actions to
7684 the store. They exist in two forms: as an in-memory representation,
7685 both on the client- and daemon-side, and as files in the store whose
7686 name end in @file{.drv}---these files are referred to as @dfn{derivation
7687 paths}. Derivations paths can be passed to the @code{build-derivations}
7688 procedure to perform the build actions they prescribe (@pxref{The
7691 @cindex fixed-output derivations
7692 Operations such as file downloads and version-control checkouts for
7693 which the expected content hash is known in advance are modeled as
7694 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
7695 of a fixed-output derivation are independent of its inputs---e.g., a
7696 source code download produces the same result regardless of the download
7697 method and tools being used.
7700 @cindex run-time dependencies
7701 @cindex dependencies, run-time
7702 The outputs of derivations---i.e., the build results---have a set of
7703 @dfn{references}, as reported by the @code{references} RPC or the
7704 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
7705 are the set of run-time dependencies of the build results. References are a
7706 subset of the inputs of the derivation; this subset is automatically computed
7707 by the build daemon by scanning all the files in the outputs.
7709 The @code{(guix derivations)} module provides a representation of
7710 derivations as Scheme objects, along with procedures to create and
7711 otherwise manipulate derivations. The lowest-level primitive to create
7712 a derivation is the @code{derivation} procedure:
7714 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
7715 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
7716 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
7717 [#:system (%current-system)] [#:references-graphs #f] @
7718 [#:allowed-references #f] [#:disallowed-references #f] @
7719 [#:leaked-env-vars #f] [#:local-build? #f] @
7720 [#:substitutable? #t] [#:properties '()]
7721 Build a derivation with the given arguments, and return the resulting
7722 @code{<derivation>} object.
7724 When @var{hash} and @var{hash-algo} are given, a
7725 @dfn{fixed-output derivation} is created---i.e., one whose result is
7726 known in advance, such as a file download. If, in addition,
7727 @var{recursive?} is true, then that fixed output may be an executable
7728 file or a directory and @var{hash} must be the hash of an archive
7729 containing this output.
7731 When @var{references-graphs} is true, it must be a list of file
7732 name/store path pairs. In that case, the reference graph of each store
7733 path is exported in the build environment in the corresponding file, in
7734 a simple text format.
7736 When @var{allowed-references} is true, it must be a list of store items
7737 or outputs that the derivation's output may refer to. Likewise,
7738 @var{disallowed-references}, if true, must be a list of things the
7739 outputs may @emph{not} refer to.
7741 When @var{leaked-env-vars} is true, it must be a list of strings
7742 denoting environment variables that are allowed to ``leak'' from the
7743 daemon's environment to the build environment. This is only applicable
7744 to fixed-output derivations---i.e., when @var{hash} is true. The main
7745 use is to allow variables such as @code{http_proxy} to be passed to
7746 derivations that download files.
7748 When @var{local-build?} is true, declare that the derivation is not a
7749 good candidate for offloading and should rather be built locally
7750 (@pxref{Daemon Offload Setup}). This is the case for small derivations
7751 where the costs of data transfers would outweigh the benefits.
7753 When @var{substitutable?} is false, declare that substitutes of the
7754 derivation's output should not be used (@pxref{Substitutes}). This is
7755 useful, for instance, when building packages that capture details of the
7756 host CPU instruction set.
7758 @var{properties} must be an association list describing ``properties'' of the
7759 derivation. It is kept as-is, uninterpreted, in the derivation.
7763 Here's an example with a shell script as its builder, assuming
7764 @var{store} is an open connection to the daemon, and @var{bash} points
7765 to a Bash executable in the store:
7768 (use-modules (guix utils)
7772 (let ((builder ; add the Bash script to the store
7773 (add-text-to-store store "my-builder.sh"
7774 "echo hello world > $out\n" '())))
7775 (derivation store "foo"
7776 bash `("-e" ,builder)
7777 #:inputs `((,bash) (,builder))
7778 #:env-vars '(("HOME" . "/homeless"))))
7779 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
7782 As can be guessed, this primitive is cumbersome to use directly. A
7783 better approach is to write build scripts in Scheme, of course! The
7784 best course of action for that is to write the build code as a
7785 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
7786 information, @pxref{G-Expressions}.
7788 Once upon a time, @code{gexp->derivation} did not exist and constructing
7789 derivations with build code written in Scheme was achieved with
7790 @code{build-expression->derivation}, documented below. This procedure
7791 is now deprecated in favor of the much nicer @code{gexp->derivation}.
7793 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
7794 @var{name} @var{exp} @
7795 [#:system (%current-system)] [#:inputs '()] @
7796 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
7797 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7798 [#:references-graphs #f] [#:allowed-references #f] @
7799 [#:disallowed-references #f] @
7800 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
7801 Return a derivation that executes Scheme expression @var{exp} as a
7802 builder for derivation @var{name}. @var{inputs} must be a list of
7803 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
7804 @code{"out"} is assumed. @var{modules} is a list of names of Guile
7805 modules from the current search path to be copied in the store,
7806 compiled, and made available in the load path during the execution of
7807 @var{exp}---e.g., @code{((guix build utils) (guix build
7808 gnu-build-system))}.
7810 @var{exp} is evaluated in an environment where @code{%outputs} is bound
7811 to a list of output/path pairs, and where @code{%build-inputs} is bound
7812 to a list of string/output-path pairs made from @var{inputs}.
7813 Optionally, @var{env-vars} is a list of string pairs specifying the name
7814 and value of environment variables visible to the builder. The builder
7815 terminates by passing the result of @var{exp} to @code{exit}; thus, when
7816 @var{exp} returns @code{#f}, the build is considered to have failed.
7818 @var{exp} is built using @var{guile-for-build} (a derivation). When
7819 @var{guile-for-build} is omitted or is @code{#f}, the value of the
7820 @code{%guile-for-build} fluid is used instead.
7822 See the @code{derivation} procedure for the meaning of
7823 @var{references-graphs}, @var{allowed-references},
7824 @var{disallowed-references}, @var{local-build?}, and
7825 @var{substitutable?}.
7829 Here's an example of a single-output derivation that creates a directory
7830 containing one file:
7833 (let ((builder '(let ((out (assoc-ref %outputs "out")))
7834 (mkdir out) ; create /gnu/store/@dots{}-goo
7835 (call-with-output-file (string-append out "/test")
7837 (display '(hello guix) p))))))
7838 (build-expression->derivation store "goo" builder))
7840 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
7844 @node The Store Monad
7845 @section The Store Monad
7849 The procedures that operate on the store described in the previous
7850 sections all take an open connection to the build daemon as their first
7851 argument. Although the underlying model is functional, they either have
7852 side effects or depend on the current state of the store.
7854 The former is inconvenient: the connection to the build daemon has to be
7855 carried around in all those functions, making it impossible to compose
7856 functions that do not take that parameter with functions that do. The
7857 latter can be problematic: since store operations have side effects
7858 and/or depend on external state, they have to be properly sequenced.
7860 @cindex monadic values
7861 @cindex monadic functions
7862 This is where the @code{(guix monads)} module comes in. This module
7863 provides a framework for working with @dfn{monads}, and a particularly
7864 useful monad for our uses, the @dfn{store monad}. Monads are a
7865 construct that allows two things: associating ``context'' with values
7866 (in our case, the context is the store), and building sequences of
7867 computations (here computations include accesses to the store). Values
7868 in a monad---values that carry this additional context---are called
7869 @dfn{monadic values}; procedures that return such values are called
7870 @dfn{monadic procedures}.
7872 Consider this ``normal'' procedure:
7875 (define (sh-symlink store)
7876 ;; Return a derivation that symlinks the 'bash' executable.
7877 (let* ((drv (package-derivation store bash))
7878 (out (derivation->output-path drv))
7879 (sh (string-append out "/bin/bash")))
7880 (build-expression->derivation store "sh"
7881 `(symlink ,sh %output))))
7884 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
7885 as a monadic function:
7888 (define (sh-symlink)
7889 ;; Same, but return a monadic value.
7890 (mlet %store-monad ((drv (package->derivation bash)))
7891 (gexp->derivation "sh"
7892 #~(symlink (string-append #$drv "/bin/bash")
7896 There are several things to note in the second version: the @code{store}
7897 parameter is now implicit and is ``threaded'' in the calls to the
7898 @code{package->derivation} and @code{gexp->derivation} monadic
7899 procedures, and the monadic value returned by @code{package->derivation}
7900 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
7902 As it turns out, the call to @code{package->derivation} can even be
7903 omitted since it will take place implicitly, as we will see later
7904 (@pxref{G-Expressions}):
7907 (define (sh-symlink)
7908 (gexp->derivation "sh"
7909 #~(symlink (string-append #$bash "/bin/bash")
7914 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
7915 @c for the funny quote.
7916 Calling the monadic @code{sh-symlink} has no effect. As someone once
7917 said, ``you exit a monad like you exit a building on fire: by running''.
7918 So, to exit the monad and get the desired effect, one must use
7919 @code{run-with-store}:
7922 (run-with-store (open-connection) (sh-symlink))
7923 @result{} /gnu/store/...-sh-symlink
7926 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
7927 new ``meta-commands'' to make it easier to deal with monadic procedures:
7928 @code{run-in-store}, and @code{enter-store-monad}. The former is used
7929 to ``run'' a single monadic value through the store:
7932 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
7933 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7936 The latter enters a recursive REPL, where all the return values are
7937 automatically run through the store:
7940 scheme@@(guile-user)> ,enter-store-monad
7941 store-monad@@(guile-user) [1]> (package->derivation hello)
7942 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7943 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
7944 $3 = "/gnu/store/@dots{}-foo"
7945 store-monad@@(guile-user) [1]> ,q
7946 scheme@@(guile-user)>
7950 Note that non-monadic values cannot be returned in the
7951 @code{store-monad} REPL.
7953 The main syntactic forms to deal with monads in general are provided by
7954 the @code{(guix monads)} module and are described below.
7956 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
7957 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
7961 @deffn {Scheme Syntax} return @var{val}
7962 Return a monadic value that encapsulates @var{val}.
7965 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
7966 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
7967 procedures @var{mproc}@dots{}@footnote{This operation is commonly
7968 referred to as ``bind'', but that name denotes an unrelated procedure in
7969 Guile. Thus we use this somewhat cryptic symbol inherited from the
7970 Haskell language.}. There can be one @var{mproc} or several of them, as
7975 (with-monad %state-monad
7977 (lambda (x) (return (+ 1 x)))
7978 (lambda (x) (return (* 2 x)))))
7982 @result{} some-state
7986 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
7988 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
7990 Bind the variables @var{var} to the monadic values @var{mval} in
7991 @var{body}, which is a sequence of expressions. As with the bind
7992 operator, this can be thought of as ``unpacking'' the raw, non-monadic
7993 value ``contained'' in @var{mval} and making @var{var} refer to that
7994 raw, non-monadic value within the scope of the @var{body}. The form
7995 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
7996 @var{val}, as per @code{let}. The binding operations occur in sequence
7997 from left to right. The last expression of @var{body} must be a monadic
7998 expression, and its result will become the result of the @code{mlet} or
7999 @code{mlet*} when run in the @var{monad}.
8001 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
8002 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
8005 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
8006 Bind @var{mexp} and the following monadic expressions in sequence,
8007 returning the result of the last expression. Every expression in the
8008 sequence must be a monadic expression.
8010 This is akin to @code{mlet}, except that the return values of the
8011 monadic expressions are ignored. In that sense, it is analogous to
8012 @code{begin}, but applied to monadic expressions.
8015 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
8016 When @var{condition} is true, evaluate the sequence of monadic
8017 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
8018 @var{condition} is false, return @code{*unspecified*} in the current
8019 monad. Every expression in the sequence must be a monadic expression.
8022 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
8023 When @var{condition} is false, evaluate the sequence of monadic
8024 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
8025 @var{condition} is true, return @code{*unspecified*} in the current
8026 monad. Every expression in the sequence must be a monadic expression.
8030 The @code{(guix monads)} module provides the @dfn{state monad}, which
8031 allows an additional value---the state---to be @emph{threaded} through
8032 monadic procedure calls.
8034 @defvr {Scheme Variable} %state-monad
8035 The state monad. Procedures in the state monad can access and change
8036 the state that is threaded.
8038 Consider the example below. The @code{square} procedure returns a value
8039 in the state monad. It returns the square of its argument, but also
8040 increments the current state value:
8044 (mlet %state-monad ((count (current-state)))
8045 (mbegin %state-monad
8046 (set-current-state (+ 1 count))
8049 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
8054 When ``run'' through @code{%state-monad}, we obtain that additional state
8055 value, which is the number of @code{square} calls.
8058 @deffn {Monadic Procedure} current-state
8059 Return the current state as a monadic value.
8062 @deffn {Monadic Procedure} set-current-state @var{value}
8063 Set the current state to @var{value} and return the previous state as a
8067 @deffn {Monadic Procedure} state-push @var{value}
8068 Push @var{value} to the current state, which is assumed to be a list,
8069 and return the previous state as a monadic value.
8072 @deffn {Monadic Procedure} state-pop
8073 Pop a value from the current state and return it as a monadic value.
8074 The state is assumed to be a list.
8077 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
8078 Run monadic value @var{mval} starting with @var{state} as the initial
8079 state. Return two values: the resulting value, and the resulting state.
8082 The main interface to the store monad, provided by the @code{(guix
8083 store)} module, is as follows.
8085 @defvr {Scheme Variable} %store-monad
8086 The store monad---an alias for @code{%state-monad}.
8088 Values in the store monad encapsulate accesses to the store. When its
8089 effect is needed, a value of the store monad must be ``evaluated'' by
8090 passing it to the @code{run-with-store} procedure (see below).
8093 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
8094 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
8095 open store connection.
8098 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
8099 Return as a monadic value the absolute file name in the store of the file
8100 containing @var{text}, a string. @var{references} is a list of store items that the
8101 resulting text file refers to; it defaults to the empty list.
8104 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
8105 Return as a monadic value the absolute file name in the store of the file
8106 containing @var{data}, a bytevector. @var{references} is a list of store
8107 items that the resulting binary file refers to; it defaults to the empty list.
8110 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
8111 [#:recursive? #t] [#:select? (const #t)]
8112 Return the name of @var{file} once interned in the store. Use
8113 @var{name} as its store name, or the basename of @var{file} if
8114 @var{name} is omitted.
8116 When @var{recursive?} is true, the contents of @var{file} are added
8117 recursively; if @var{file} designates a flat file and @var{recursive?}
8118 is true, its contents are added, and its permission bits are kept.
8120 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
8121 @var{stat})} for each directory entry, where @var{file} is the entry's
8122 absolute file name and @var{stat} is the result of @code{lstat}; exclude
8123 entries for which @var{select?} does not return true.
8125 The example below adds a file to the store, under two different names:
8128 (run-with-store (open-connection)
8129 (mlet %store-monad ((a (interned-file "README"))
8130 (b (interned-file "README" "LEGU-MIN")))
8131 (return (list a b))))
8133 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
8138 The @code{(guix packages)} module exports the following package-related
8141 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
8142 [#:system (%current-system)] [#:target #f] @
8145 value in the absolute file name of @var{file} within the @var{output}
8146 directory of @var{package}. When @var{file} is omitted, return the name
8147 of the @var{output} directory of @var{package}. When @var{target} is
8148 true, use it as a cross-compilation target triplet.
8150 Note that this procedure does @emph{not} build @var{package}. Thus, the
8151 result might or might not designate an existing file. We recommend not
8152 using this procedure unless you know what you are doing.
8155 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
8156 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
8157 @var{target} [@var{system}]
8158 Monadic version of @code{package-derivation} and
8159 @code{package-cross-derivation} (@pxref{Defining Packages}).
8164 @section G-Expressions
8166 @cindex G-expression
8167 @cindex build code quoting
8168 So we have ``derivations'', which represent a sequence of build actions
8169 to be performed to produce an item in the store (@pxref{Derivations}).
8170 These build actions are performed when asking the daemon to actually
8171 build the derivations; they are run by the daemon in a container
8172 (@pxref{Invoking guix-daemon}).
8174 @cindex strata of code
8175 It should come as no surprise that we like to write these build actions
8176 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
8177 code@footnote{The term @dfn{stratum} in this context was coined by
8178 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
8179 Kiselyov, who has written insightful
8180 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
8181 on this topic}, refers to this kind of code generation as
8182 @dfn{staging}.}: the ``host code''---code that defines packages, talks
8183 to the daemon, etc.---and the ``build code''---code that actually
8184 performs build actions, such as making directories, invoking
8185 @command{make}, etc.
8187 To describe a derivation and its build actions, one typically needs to
8188 embed build code inside host code. It boils down to manipulating build
8189 code as data, and the homoiconicity of Scheme---code has a direct
8190 representation as data---comes in handy for that. But we need more than
8191 the normal @code{quasiquote} mechanism in Scheme to construct build
8194 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
8195 S-expressions adapted to build expressions. G-expressions, or
8196 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
8197 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
8198 @code{#$}, and @code{#$@@}), which are comparable to
8199 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
8200 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
8201 GNU Guile Reference Manual}). However, there are major differences:
8205 Gexps are meant to be written to a file and run or manipulated by other
8209 When a high-level object such as a package or derivation is unquoted
8210 inside a gexp, the result is as if its output file name had been
8214 Gexps carry information about the packages or derivations they refer to,
8215 and these dependencies are automatically added as inputs to the build
8216 processes that use them.
8219 @cindex lowering, of high-level objects in gexps
8220 This mechanism is not limited to package and derivation
8221 objects: @dfn{compilers} able to ``lower'' other high-level objects to
8222 derivations or files in the store can be defined,
8223 such that these objects can also be inserted
8224 into gexps. For example, a useful type of high-level objects that can be
8225 inserted in a gexp is ``file-like objects'', which make it easy to
8226 add files to the store and to refer to them in
8227 derivations and such (see @code{local-file} and @code{plain-file}
8230 To illustrate the idea, here is an example of a gexp:
8237 (symlink (string-append #$coreutils "/bin/ls")
8241 This gexp can be passed to @code{gexp->derivation}; we obtain a
8242 derivation that builds a directory containing exactly one symlink to
8243 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
8246 (gexp->derivation "the-thing" build-exp)
8249 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
8250 substituted to the reference to the @var{coreutils} package in the
8251 actual build code, and @var{coreutils} is automatically made an input to
8252 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
8253 output)}) is replaced by a string containing the directory name of the
8254 output of the derivation.
8256 @cindex cross compilation
8257 In a cross-compilation context, it is useful to distinguish between
8258 references to the @emph{native} build of a package---that can run on the
8259 host---versus references to cross builds of a package. To that end, the
8260 @code{#+} plays the same role as @code{#$}, but is a reference to a
8261 native package build:
8264 (gexp->derivation "vi"
8267 (mkdir (string-append #$output "/bin"))
8268 (system* (string-append #+coreutils "/bin/ln")
8270 (string-append #$emacs "/bin/emacs")
8271 (string-append #$output "/bin/vi")))
8272 #:target "aarch64-linux-gnu")
8276 In the example above, the native build of @var{coreutils} is used, so
8277 that @command{ln} can actually run on the host; but then the
8278 cross-compiled build of @var{emacs} is referenced.
8280 @cindex imported modules, for gexps
8281 @findex with-imported-modules
8282 Another gexp feature is @dfn{imported modules}: sometimes you want to be
8283 able to use certain Guile modules from the ``host environment'' in the
8284 gexp, so those modules should be imported in the ``build environment''.
8285 The @code{with-imported-modules} form allows you to express that:
8288 (let ((build (with-imported-modules '((guix build utils))
8290 (use-modules (guix build utils))
8291 (mkdir-p (string-append #$output "/bin"))))))
8292 (gexp->derivation "empty-dir"
8295 (display "success!\n")
8300 In this example, the @code{(guix build utils)} module is automatically
8301 pulled into the isolated build environment of our gexp, such that
8302 @code{(use-modules (guix build utils))} works as expected.
8304 @cindex module closure
8305 @findex source-module-closure
8306 Usually you want the @emph{closure} of the module to be imported---i.e.,
8307 the module itself and all the modules it depends on---rather than just
8308 the module; failing to do that, attempts to use the module will fail
8309 because of missing dependent modules. The @code{source-module-closure}
8310 procedure computes the closure of a module by looking at its source file
8311 headers, which comes in handy in this case:
8314 (use-modules (guix modules)) ;for 'source-module-closure'
8316 (with-imported-modules (source-module-closure
8317 '((guix build utils)
8319 (gexp->derivation "something-with-vms"
8321 (use-modules (guix build utils)
8326 @cindex extensions, for gexps
8327 @findex with-extensions
8328 In the same vein, sometimes you want to import not just pure-Scheme
8329 modules, but also ``extensions'' such as Guile bindings to C libraries
8330 or other ``full-blown'' packages. Say you need the @code{guile-json}
8331 package available on the build side, here's how you would do it:
8334 (use-modules (gnu packages guile)) ;for 'guile-json'
8336 (with-extensions (list guile-json)
8337 (gexp->derivation "something-with-json"
8339 (use-modules (json))
8343 The syntactic form to construct gexps is summarized below.
8345 @deffn {Scheme Syntax} #~@var{exp}
8346 @deffnx {Scheme Syntax} (gexp @var{exp})
8347 Return a G-expression containing @var{exp}. @var{exp} may contain one
8348 or more of the following forms:
8352 @itemx (ungexp @var{obj})
8353 Introduce a reference to @var{obj}. @var{obj} may have one of the
8354 supported types, for example a package or a
8355 derivation, in which case the @code{ungexp} form is replaced by its
8356 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
8358 If @var{obj} is a list, it is traversed and references to supported
8359 objects are substituted similarly.
8361 If @var{obj} is another gexp, its contents are inserted and its
8362 dependencies are added to those of the containing gexp.
8364 If @var{obj} is another kind of object, it is inserted as is.
8366 @item #$@var{obj}:@var{output}
8367 @itemx (ungexp @var{obj} @var{output})
8368 This is like the form above, but referring explicitly to the
8369 @var{output} of @var{obj}---this is useful when @var{obj} produces
8370 multiple outputs (@pxref{Packages with Multiple Outputs}).
8373 @itemx #+@var{obj}:output
8374 @itemx (ungexp-native @var{obj})
8375 @itemx (ungexp-native @var{obj} @var{output})
8376 Same as @code{ungexp}, but produces a reference to the @emph{native}
8377 build of @var{obj} when used in a cross compilation context.
8379 @item #$output[:@var{output}]
8380 @itemx (ungexp output [@var{output}])
8381 Insert a reference to derivation output @var{output}, or to the main
8382 output when @var{output} is omitted.
8384 This only makes sense for gexps passed to @code{gexp->derivation}.
8387 @itemx (ungexp-splicing @var{lst})
8388 Like the above, but splices the contents of @var{lst} inside the
8392 @itemx (ungexp-native-splicing @var{lst})
8393 Like the above, but refers to native builds of the objects listed in
8398 G-expressions created by @code{gexp} or @code{#~} are run-time objects
8399 of the @code{gexp?} type (see below).
8402 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
8403 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
8404 in their execution environment.
8406 Each item in @var{modules} can be the name of a module, such as
8407 @code{(guix build utils)}, or it can be a module name, followed by an
8408 arrow, followed by a file-like object:
8411 `((guix build utils)
8413 ((guix config) => ,(scheme-file "config.scm"
8414 #~(define-module @dots{}))))
8418 In the example above, the first two modules are taken from the search
8419 path, and the last one is created from the given file-like object.
8421 This form has @emph{lexical} scope: it has an effect on the gexps
8422 directly defined in @var{body}@dots{}, but not on those defined, say, in
8423 procedures called from @var{body}@dots{}.
8426 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
8427 Mark the gexps defined in @var{body}@dots{} as requiring
8428 @var{extensions} in their build and execution environment.
8429 @var{extensions} is typically a list of package objects such as those
8430 defined in the @code{(gnu packages guile)} module.
8432 Concretely, the packages listed in @var{extensions} are added to the
8433 load path while compiling imported modules in @var{body}@dots{}; they
8434 are also added to the load path of the gexp returned by
8438 @deffn {Scheme Procedure} gexp? @var{obj}
8439 Return @code{#t} if @var{obj} is a G-expression.
8442 G-expressions are meant to be written to disk, either as code building
8443 some derivation, or as plain files in the store. The monadic procedures
8444 below allow you to do that (@pxref{The Store Monad}, for more
8445 information about monads).
8447 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
8448 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
8449 [#:hash #f] [#:hash-algo #f] @
8450 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
8451 [#:module-path @code{%load-path}] @
8452 [#:effective-version "2.2"] @
8453 [#:references-graphs #f] [#:allowed-references #f] @
8454 [#:disallowed-references #f] @
8455 [#:leaked-env-vars #f] @
8456 [#:script-name (string-append @var{name} "-builder")] @
8457 [#:deprecation-warnings #f] @
8458 [#:local-build? #f] [#:substitutable? #t] @
8459 [#:properties '()] [#:guile-for-build #f]
8460 Return a derivation @var{name} that runs @var{exp} (a gexp) with
8461 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
8462 stored in a file called @var{script-name}. When @var{target} is true,
8463 it is used as the cross-compilation target triplet for packages referred
8466 @var{modules} is deprecated in favor of @code{with-imported-modules}.
8468 make @var{modules} available in the evaluation context of @var{exp};
8469 @var{modules} is a list of names of Guile modules searched in
8470 @var{module-path} to be copied in the store, compiled, and made available in
8471 the load path during the execution of @var{exp}---e.g., @code{((guix
8472 build utils) (guix build gnu-build-system))}.
8474 @var{effective-version} determines the string to use when adding extensions of
8475 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
8477 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
8480 When @var{references-graphs} is true, it must be a list of tuples of one of the
8484 (@var{file-name} @var{package})
8485 (@var{file-name} @var{package} @var{output})
8486 (@var{file-name} @var{derivation})
8487 (@var{file-name} @var{derivation} @var{output})
8488 (@var{file-name} @var{store-item})
8491 The right-hand-side of each element of @var{references-graphs} is automatically made
8492 an input of the build process of @var{exp}. In the build environment, each
8493 @var{file-name} contains the reference graph of the corresponding item, in a simple
8496 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
8497 In the latter case, the list denotes store items that the result is allowed to
8498 refer to. Any reference to another store item will lead to a build error.
8499 Similarly for @var{disallowed-references}, which can list items that must not be
8500 referenced by the outputs.
8502 @var{deprecation-warnings} determines whether to show deprecation warnings while
8503 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
8505 The other arguments are as for @code{derivation} (@pxref{Derivations}).
8508 @cindex file-like objects
8509 The @code{local-file}, @code{plain-file}, @code{computed-file},
8510 @code{program-file}, and @code{scheme-file} procedures below return
8511 @dfn{file-like objects}. That is, when unquoted in a G-expression,
8512 these objects lead to a file in the store. Consider this G-expression:
8515 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
8516 #$(local-file "/tmp/my-nscd.conf"))
8519 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
8520 to the store. Once expanded, for instance @i{via}
8521 @code{gexp->derivation}, the G-expression refers to that copy under
8522 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
8523 does not have any effect on what the G-expression does.
8524 @code{plain-file} can be used similarly; it differs in that the file
8525 content is directly passed as a string.
8527 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
8528 [#:recursive? #f] [#:select? (const #t)]
8529 Return an object representing local file @var{file} to add to the store;
8530 this object can be used in a gexp. If @var{file} is a literal string
8531 denoting a relative file name, it is looked up relative to the source
8532 file where it appears; if @var{file} is not a literal string, it is
8533 looked up relative to the current working directory at run time.
8534 @var{file} will be added to the store under @var{name}--by default the
8535 base name of @var{file}.
8537 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
8538 designates a flat file and @var{recursive?} is true, its contents are added, and its
8539 permission bits are kept.
8541 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
8542 @var{stat})} for each directory entry, where @var{file} is the entry's
8543 absolute file name and @var{stat} is the result of @code{lstat}; exclude
8544 entries for which @var{select?} does not return true.
8546 This is the declarative counterpart of the @code{interned-file} monadic
8547 procedure (@pxref{The Store Monad, @code{interned-file}}).
8550 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
8551 Return an object representing a text file called @var{name} with the given
8552 @var{content} (a string or a bytevector) to be added to the store.
8554 This is the declarative counterpart of @code{text-file}.
8557 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
8560 Return an object representing the store item @var{name}, a file or
8561 directory computed by @var{gexp}. When @var{local-build?} is true (the
8562 default), the derivation is built locally. @var{options} is a list of
8563 additional arguments to pass to @code{gexp->derivation}.
8565 This is the declarative counterpart of @code{gexp->derivation}.
8568 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
8569 [#:guile (default-guile)] [#:module-path %load-path] @
8570 [#:system (%current-system)] [#:target #f]
8571 Return an executable script @var{name} that runs @var{exp} using
8572 @var{guile}, with @var{exp}'s imported modules in its search path.
8573 Look up @var{exp}'s modules in @var{module-path}.
8575 The example below builds a script that simply invokes the @command{ls}
8579 (use-modules (guix gexp) (gnu packages base))
8581 (gexp->script "list-files"
8582 #~(execl #$(file-append coreutils "/bin/ls")
8586 When ``running'' it through the store (@pxref{The Store Monad,
8587 @code{run-with-store}}), we obtain a derivation that produces an
8588 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
8591 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
8593 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
8597 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
8598 [#:guile #f] [#:module-path %load-path]
8599 Return an object representing the executable store item @var{name} that
8600 runs @var{gexp}. @var{guile} is the Guile package used to execute that
8601 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
8603 This is the declarative counterpart of @code{gexp->script}.
8606 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
8607 [#:set-load-path? #t] [#:module-path %load-path] @
8609 [#:guile (default-guile)]
8610 Return a derivation that builds a file @var{name} containing @var{exp}.
8611 When @var{splice?} is true, @var{exp} is considered to be a list of
8612 expressions that will be spliced in the resulting file.
8614 When @var{set-load-path?} is true, emit code in the resulting file to
8615 set @code{%load-path} and @code{%load-compiled-path} to honor
8616 @var{exp}'s imported modules. Look up @var{exp}'s modules in
8619 The resulting file holds references to all the dependencies of @var{exp}
8620 or a subset thereof.
8623 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} @
8624 [#:splice? #f] [#:set-load-path? #t]
8625 Return an object representing the Scheme file @var{name} that contains
8628 This is the declarative counterpart of @code{gexp->file}.
8631 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
8632 Return as a monadic value a derivation that builds a text file
8633 containing all of @var{text}. @var{text} may list, in addition to
8634 strings, objects of any type that can be used in a gexp: packages,
8635 derivations, local file objects, etc. The resulting store file holds
8636 references to all these.
8638 This variant should be preferred over @code{text-file} anytime the file
8639 to create will reference items from the store. This is typically the
8640 case when building a configuration file that embeds store file names,
8644 (define (profile.sh)
8645 ;; Return the name of a shell script in the store that
8646 ;; initializes the 'PATH' environment variable.
8647 (text-file* "profile.sh"
8648 "export PATH=" coreutils "/bin:"
8649 grep "/bin:" sed "/bin\n"))
8652 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
8653 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
8654 preventing them from being garbage-collected during its lifetime.
8657 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
8658 Return an object representing store file @var{name} containing
8659 @var{text}. @var{text} is a sequence of strings and file-like objects,
8663 (mixed-text-file "profile"
8664 "export PATH=" coreutils "/bin:" grep "/bin")
8667 This is the declarative counterpart of @code{text-file*}.
8670 @deffn {Scheme Procedure} file-union @var{name} @var{files}
8671 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
8672 Each item in @var{files} must be a two-element list where the first element is the
8673 file name to use in the new directory, and the second element is a gexp
8674 denoting the target file. Here's an example:
8678 `(("hosts" ,(plain-file "hosts"
8679 "127.0.0.1 localhost"))
8680 ("bashrc" ,(plain-file "bashrc"
8681 "alias ls='ls --color=auto'"))))
8684 This yields an @code{etc} directory containing these two files.
8687 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
8688 Return a directory that is the union of @var{things}, where @var{things} is a list of
8689 file-like objects denoting directories. For example:
8692 (directory-union "guile+emacs" (list guile emacs))
8695 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
8698 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
8699 Return a file-like object that expands to the concatenation of @var{obj}
8700 and @var{suffix}, where @var{obj} is a lowerable object and each
8701 @var{suffix} is a string.
8703 As an example, consider this gexp:
8706 (gexp->script "run-uname"
8707 #~(system* #$(file-append coreutils
8711 The same effect could be achieved with:
8714 (gexp->script "run-uname"
8715 #~(system* (string-append #$coreutils
8719 There is one difference though: in the @code{file-append} case, the
8720 resulting script contains the absolute file name as a string, whereas in
8721 the second case, the resulting script contains a @code{(string-append
8722 @dots{})} expression to construct the file name @emph{at run time}.
8725 @deffn {Scheme Syntax} let-system @var{system} @var{body}@dots{}
8726 @deffnx {Scheme Syntax} let-system (@var{system} @var{target}) @var{body}@dots{}
8727 Bind @var{system} to the currently targeted system---e.g.,
8728 @code{"x86_64-linux"}---within @var{body}.
8730 In the second case, additionally bind @var{target} to the current
8731 cross-compilation target---a GNU triplet such as
8732 @code{"arm-linux-gnueabihf"}---or @code{#f} if we are not
8735 @code{let-system} is useful in the occasional case where the object
8736 spliced into the gexp depends on the target system, as in this example:
8740 #+(let-system system
8741 (cond ((string-prefix? "armhf-" system)
8742 (file-append qemu "/bin/qemu-system-arm"))
8743 ((string-prefix? "x86_64-" system)
8744 (file-append qemu "/bin/qemu-system-x86_64"))
8747 "-net" "user" #$image)
8751 @deffn {Scheme Syntax} with-parameters ((@var{parameter} @var{value}) @dots{}) @var{exp}
8752 This macro is similar to the @code{parameterize} form for
8753 dynamically-bound @dfn{parameters} (@pxref{Parameters,,, guile, GNU
8754 Guile Reference Manual}). The key difference is that it takes effect
8755 when the file-like object returned by @var{exp} is lowered to a
8756 derivation or store item.
8758 A typical use of @code{with-parameters} is to force the system in effect
8762 (with-parameters ((%current-system "i686-linux"))
8766 The example above returns an object that corresponds to the i686 build
8767 of Coreutils, regardless of the current value of @code{%current-system}.
8771 Of course, in addition to gexps embedded in ``host'' code, there are
8772 also modules containing build tools. To make it clear that they are
8773 meant to be used in the build stratum, these modules are kept in the
8774 @code{(guix build @dots{})} name space.
8776 @cindex lowering, of high-level objects in gexps
8777 Internally, high-level objects are @dfn{lowered}, using their compiler,
8778 to either derivations or store items. For instance, lowering a package
8779 yields a derivation, and lowering a @code{plain-file} yields a store
8780 item. This is achieved using the @code{lower-object} monadic procedure.
8782 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
8784 Return as a value in @code{%store-monad} the derivation or store item
8785 corresponding to @var{obj} for @var{system}, cross-compiling for
8786 @var{target} if @var{target} is true. @var{obj} must be an object that
8787 has an associated gexp compiler, such as a @code{<package>}.
8790 @node Invoking guix repl
8791 @section Invoking @command{guix repl}
8793 @cindex REPL, read-eval-print loop, script
8794 The @command{guix repl} command makes it easier to program Guix in Guile
8795 by launching a Guile @dfn{read-eval-print loop} (REPL) for interactive
8796 programming (@pxref{Using Guile Interactively,,, guile,
8797 GNU Guile Reference Manual}), or by running Guile scripts
8798 (@pxref{Running Guile Scripts,,, guile,
8799 GNU Guile Reference Manual}).
8800 Compared to just launching the @command{guile}
8801 command, @command{guix repl} guarantees that all the Guix modules and all its
8802 dependencies are available in the search path.
8804 The general syntax is:
8807 guix repl @var{options} [@var{file} @var{args}]
8810 When a @var{file} argument is provided, @var{file} is
8811 executed as a Guile scripts:
8814 guix repl my-script.scm
8817 To pass arguments to the script, use @code{--} to prevent them from
8818 being interpreted as arguments to @command{guix repl} itself:
8821 guix repl -- my-script.scm --input=foo.txt
8824 To make a script executable directly from the shell, using the guix
8825 executable that is on the user's search path, add the following two
8826 lines at the top of the script:
8829 @code{#!/usr/bin/env -S guix repl --}
8833 Without a file name argument, a Guile REPL is started:
8837 scheme@@(guile-user)> ,use (gnu packages base)
8838 scheme@@(guile-user)> coreutils
8839 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
8843 In addition, @command{guix repl} implements a simple machine-readable REPL
8844 protocol for use by @code{(guix inferior)}, a facility to interact with
8845 @dfn{inferiors}, separate processes running a potentially different revision
8848 The available options are as follows:
8851 @item --type=@var{type}
8852 @itemx -t @var{type}
8853 Start a REPL of the given @var{TYPE}, which can be one of the following:
8857 This is default, and it spawns a standard full-featured Guile REPL.
8859 Spawn a REPL that uses the machine-readable protocol. This is the protocol
8860 that the @code{(guix inferior)} module speaks.
8863 @item --listen=@var{endpoint}
8864 By default, @command{guix repl} reads from standard input and writes to
8865 standard output. When this option is passed, it will instead listen for
8866 connections on @var{endpoint}. Here are examples of valid options:
8869 @item --listen=tcp:37146
8870 Accept connections on localhost on port 37146.
8872 @item --listen=unix:/tmp/socket
8873 Accept connections on the Unix-domain socket @file{/tmp/socket}.
8876 @item --load-path=@var{directory}
8877 @itemx -L @var{directory}
8878 Add @var{directory} to the front of the package module search path
8879 (@pxref{Package Modules}).
8881 This allows users to define their own packages and make them visible to
8885 Inhibit loading of the @file{~/.guile} file. By default, that
8886 configuration file is loaded when spawning a @code{guile} REPL.
8889 @c *********************************************************************
8893 This section describes Guix command-line utilities. Some of them are
8894 primarily targeted at developers and users who write new package
8895 definitions, while others are more generally useful. They complement
8896 the Scheme programming interface of Guix in a convenient way.
8899 * Invoking guix build:: Building packages from the command line.
8900 * Invoking guix edit:: Editing package definitions.
8901 * Invoking guix download:: Downloading a file and printing its hash.
8902 * Invoking guix hash:: Computing the cryptographic hash of a file.
8903 * Invoking guix import:: Importing package definitions.
8904 * Invoking guix refresh:: Updating package definitions.
8905 * Invoking guix lint:: Finding errors in package definitions.
8906 * Invoking guix size:: Profiling disk usage.
8907 * Invoking guix graph:: Visualizing the graph of packages.
8908 * Invoking guix publish:: Sharing substitutes.
8909 * Invoking guix challenge:: Challenging substitute servers.
8910 * Invoking guix copy:: Copying to and from a remote store.
8911 * Invoking guix container:: Process isolation.
8912 * Invoking guix weather:: Assessing substitute availability.
8913 * Invoking guix processes:: Listing client processes.
8916 @node Invoking guix build
8917 @section Invoking @command{guix build}
8919 @cindex package building
8920 @cindex @command{guix build}
8921 The @command{guix build} command builds packages or derivations and
8922 their dependencies, and prints the resulting store paths. Note that it
8923 does not modify the user's profile---this is the job of the
8924 @command{guix package} command (@pxref{Invoking guix package}). Thus,
8925 it is mainly useful for distribution developers.
8927 The general syntax is:
8930 guix build @var{options} @var{package-or-derivation}@dots{}
8933 As an example, the following command builds the latest versions of Emacs
8934 and of Guile, displays their build logs, and finally displays the
8935 resulting directories:
8938 guix build emacs guile
8941 Similarly, the following command builds all the available packages:
8944 guix build --quiet --keep-going \
8945 `guix package -A | cut -f1,2 --output-delimiter=@@`
8948 @var{package-or-derivation} may be either the name of a package found in
8949 the software distribution such as @code{coreutils} or
8950 @code{coreutils@@8.20}, or a derivation such as
8951 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
8952 package with the corresponding name (and optionally version) is searched
8953 for among the GNU distribution modules (@pxref{Package Modules}).
8955 Alternatively, the @option{--expression} option may be used to specify a
8956 Scheme expression that evaluates to a package; this is useful when
8957 disambiguating among several same-named packages or package variants is
8960 There may be zero or more @var{options}. The available options are
8961 described in the subsections below.
8964 * Common Build Options:: Build options for most commands.
8965 * Package Transformation Options:: Creating variants of packages.
8966 * Additional Build Options:: Options specific to 'guix build'.
8967 * Debugging Build Failures:: Real life packaging experience.
8970 @node Common Build Options
8971 @subsection Common Build Options
8973 A number of options that control the build process are common to
8974 @command{guix build} and other commands that can spawn builds, such as
8975 @command{guix package} or @command{guix archive}. These are the
8980 @item --load-path=@var{directory}
8981 @itemx -L @var{directory}
8982 Add @var{directory} to the front of the package module search path
8983 (@pxref{Package Modules}).
8985 This allows users to define their own packages and make them visible to
8986 the command-line tools.
8990 Keep the build tree of failed builds. Thus, if a build fails, its build
8991 tree is kept under @file{/tmp}, in a directory whose name is shown at
8992 the end of the build log. This is useful when debugging build issues.
8993 @xref{Debugging Build Failures}, for tips and tricks on how to debug
8996 This option implies @option{--no-offload}, and it has no effect when
8997 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
8998 Store, the @env{GUIX_DAEMON_SOCKET} variable}).
9002 Keep going when some of the derivations fail to build; return only once
9003 all the builds have either completed or failed.
9005 The default behavior is to stop as soon as one of the specified
9006 derivations has failed.
9010 Do not build the derivations.
9012 @anchor{fallback-option}
9014 When substituting a pre-built binary fails, fall back to building
9015 packages locally (@pxref{Substitution Failure}).
9017 @item --substitute-urls=@var{urls}
9018 @anchor{client-substitute-urls}
9019 Consider @var{urls} the whitespace-separated list of substitute source
9020 URLs, overriding the default list of URLs of @command{guix-daemon}
9021 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
9023 This means that substitutes may be downloaded from @var{urls}, provided
9024 they are signed by a key authorized by the system administrator
9025 (@pxref{Substitutes}).
9027 When @var{urls} is the empty string, substitutes are effectively
9030 @item --no-substitutes
9031 Do not use substitutes for build products. That is, always build things
9032 locally instead of allowing downloads of pre-built binaries
9033 (@pxref{Substitutes}).
9036 Do not ``graft'' packages. In practice, this means that package updates
9037 available as grafts are not applied. @xref{Security Updates}, for more
9038 information on grafts.
9040 @item --rounds=@var{n}
9041 Build each derivation @var{n} times in a row, and raise an error if
9042 consecutive build results are not bit-for-bit identical.
9044 This is a useful way to detect non-deterministic builds processes.
9045 Non-deterministic build processes are a problem because they make it
9046 practically impossible for users to @emph{verify} whether third-party
9047 binaries are genuine. @xref{Invoking guix challenge}, for more.
9049 Note that, currently, the differing build results are not kept around,
9050 so you will have to manually investigate in case of an error---e.g., by
9051 stashing one of the build results with @code{guix archive --export}
9052 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
9056 Do not use offload builds to other machines (@pxref{Daemon Offload
9057 Setup}). That is, always build things locally instead of offloading
9058 builds to remote machines.
9060 @item --max-silent-time=@var{seconds}
9061 When the build or substitution process remains silent for more than
9062 @var{seconds}, terminate it and report a build failure.
9064 By default, the daemon's setting is honored (@pxref{Invoking
9065 guix-daemon, @option{--max-silent-time}}).
9067 @item --timeout=@var{seconds}
9068 Likewise, when the build or substitution process lasts for more than
9069 @var{seconds}, terminate it and report a build failure.
9071 By default, the daemon's setting is honored (@pxref{Invoking
9072 guix-daemon, @option{--timeout}}).
9074 @c Note: This option is actually not part of %standard-build-options but
9075 @c most programs honor it.
9076 @cindex verbosity, of the command-line tools
9077 @cindex build logs, verbosity
9078 @item -v @var{level}
9079 @itemx --verbosity=@var{level}
9080 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
9081 output is produced, 1 is for quiet output, and 2 shows all the build log
9082 output on standard error.
9084 @item --cores=@var{n}
9086 Allow the use of up to @var{n} CPU cores for the build. The special
9087 value @code{0} means to use as many CPU cores as available.
9089 @item --max-jobs=@var{n}
9091 Allow at most @var{n} build jobs in parallel. @xref{Invoking
9092 guix-daemon, @option{--max-jobs}}, for details about this option and the
9093 equivalent @command{guix-daemon} option.
9095 @item --debug=@var{level}
9096 Produce debugging output coming from the build daemon. @var{level} must be an
9097 integer between 0 and 5; higher means more verbose output. Setting a level of
9098 4 or more may be helpful when debugging setup issues with the build daemon.
9102 Behind the scenes, @command{guix build} is essentially an interface to
9103 the @code{package-derivation} procedure of the @code{(guix packages)}
9104 module, and to the @code{build-derivations} procedure of the @code{(guix
9105 derivations)} module.
9107 In addition to options explicitly passed on the command line,
9108 @command{guix build} and other @command{guix} commands that support
9109 building honor the @env{GUIX_BUILD_OPTIONS} environment variable.
9111 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
9112 Users can define this variable to a list of command line options that
9113 will automatically be used by @command{guix build} and other
9114 @command{guix} commands that can perform builds, as in the example
9118 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
9121 These options are parsed independently, and the result is appended to
9122 the parsed command-line options.
9126 @node Package Transformation Options
9127 @subsection Package Transformation Options
9129 @cindex package variants
9130 Another set of command-line options supported by @command{guix build}
9131 and also @command{guix package} are @dfn{package transformation
9132 options}. These are options that make it possible to define @dfn{package
9133 variants}---for instance, packages built from different source code.
9134 This is a convenient way to create customized packages on the fly
9135 without having to type in the definitions of package variants
9136 (@pxref{Defining Packages}).
9140 @item --with-source=@var{source}
9141 @itemx --with-source=@var{package}=@var{source}
9142 @itemx --with-source=@var{package}@@@var{version}=@var{source}
9143 Use @var{source} as the source of @var{package}, and @var{version} as
9145 @var{source} must be a file name or a URL, as for @command{guix
9146 download} (@pxref{Invoking guix download}).
9148 When @var{package} is omitted,
9149 it is taken to be the package name specified on the
9150 command line that matches the base of @var{source}---e.g.,
9151 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
9152 package is @code{guile}.
9154 Likewise, when @var{version} is omitted, the version string is inferred from
9155 @var{source}; in the previous example, it is @code{2.0.10}.
9157 This option allows users to try out versions of packages other than the
9158 one provided by the distribution. The example below downloads
9159 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
9160 the @code{ed} package:
9163 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
9166 As a developer, @option{--with-source} makes it easy to test release
9170 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
9173 @dots{} or to build from a checkout in a pristine environment:
9176 $ git clone git://git.sv.gnu.org/guix.git
9177 $ guix build guix --with-source=guix@@1.0=./guix
9180 @item --with-input=@var{package}=@var{replacement}
9181 Replace dependency on @var{package} by a dependency on
9182 @var{replacement}. @var{package} must be a package name, and
9183 @var{replacement} must be a package specification such as @code{guile}
9184 or @code{guile@@1.8}.
9186 For instance, the following command builds Guix, but replaces its
9187 dependency on the current stable version of Guile with a dependency on
9188 the legacy version of Guile, @code{guile@@2.0}:
9191 guix build --with-input=guile=guile@@2.0 guix
9194 This is a recursive, deep replacement. So in this example, both
9195 @code{guix} and its dependency @code{guile-json} (which also depends on
9196 @code{guile}) get rebuilt against @code{guile@@2.0}.
9198 This is implemented using the @code{package-input-rewriting} Scheme
9199 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
9201 @item --with-graft=@var{package}=@var{replacement}
9202 This is similar to @option{--with-input} but with an important difference:
9203 instead of rebuilding the whole dependency chain, @var{replacement} is
9204 built and then @dfn{grafted} onto the binaries that were initially
9205 referring to @var{package}. @xref{Security Updates}, for more
9206 information on grafts.
9208 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
9209 and all its dependencies, replacing references to the version of GnuTLS
9210 they currently refer to:
9213 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
9216 This has the advantage of being much faster than rebuilding everything.
9217 But there is a caveat: it works if and only if @var{package} and
9218 @var{replacement} are strictly compatible---for example, if they provide
9219 a library, the application binary interface (ABI) of those libraries
9220 must be compatible. If @var{replacement} is somehow incompatible with
9221 @var{package}, then the resulting package may be unusable. Use with
9224 @item --with-git-url=@var{package}=@var{url}
9225 @cindex Git, using the latest commit
9226 @cindex latest commit, building
9227 Build @var{package} from the latest commit of the @code{master} branch of the
9228 Git repository at @var{url}. Git sub-modules of the repository are fetched,
9231 For example, the following command builds the NumPy Python library against the
9232 latest commit of the master branch of Python itself:
9235 guix build python-numpy \
9236 --with-git-url=python=https://github.com/python/cpython
9239 This option can also be combined with @option{--with-branch} or
9240 @option{--with-commit} (see below).
9242 @cindex continuous integration
9243 Obviously, since it uses the latest commit of the given branch, the result of
9244 such a command varies over time. Nevertheless it is a convenient way to
9245 rebuild entire software stacks against the latest commit of one or more
9246 packages. This is particularly useful in the context of continuous
9249 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
9250 consecutive accesses to the same repository. You may want to clean it up once
9251 in a while to save disk space.
9253 @item --with-branch=@var{package}=@var{branch}
9254 Build @var{package} from the latest commit of @var{branch}. If the
9255 @code{source} field of @var{package} is an origin with the @code{git-fetch}
9256 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
9257 repository URL is taken from that @code{source}. Otherwise you have to use
9258 @option{--with-git-url} to specify the URL of the Git repository.
9260 For instance, the following command builds @code{guile-sqlite3} from the
9261 latest commit of its @code{master} branch, and then builds @code{guix} (which
9262 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
9263 specific @code{guile-sqlite3} build:
9266 guix build --with-branch=guile-sqlite3=master cuirass
9269 @item --with-commit=@var{package}=@var{commit}
9270 This is similar to @option{--with-branch}, except that it builds from
9271 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
9272 Git commit SHA1 identifier or a tag.
9275 @node Additional Build Options
9276 @subsection Additional Build Options
9278 The command-line options presented below are specific to @command{guix
9285 Build quietly, without displaying the build log; this is equivalent to
9286 @option{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
9287 (or similar) and can always be retrieved using the @option{--log-file} option.
9289 @item --file=@var{file}
9290 @itemx -f @var{file}
9291 Build the package, derivation, or other file-like object that the code within
9292 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
9294 As an example, @var{file} might contain a package definition like this
9295 (@pxref{Defining Packages}):
9298 @include package-hello.scm
9301 The @var{file} may also contain a JSON representation of one or more
9302 package definitions. Running @code{guix build -f} on @file{hello.json}
9303 with the following contents would result in building the packages
9304 @code{myhello} and @code{greeter}:
9307 @verbatiminclude package-hello.json
9310 @item --manifest=@var{manifest}
9311 @itemx -m @var{manifest}
9312 Build all packages listed in the given @var{manifest}
9313 (@pxref{profile-manifest, @option{--manifest}}).
9315 @item --expression=@var{expr}
9316 @itemx -e @var{expr}
9317 Build the package or derivation @var{expr} evaluates to.
9319 For example, @var{expr} may be @code{(@@ (gnu packages guile)
9320 guile-1.8)}, which unambiguously designates this specific variant of
9321 version 1.8 of Guile.
9323 Alternatively, @var{expr} may be a G-expression, in which case it is used
9324 as a build program passed to @code{gexp->derivation}
9325 (@pxref{G-Expressions}).
9327 Lastly, @var{expr} may refer to a zero-argument monadic procedure
9328 (@pxref{The Store Monad}). The procedure must return a derivation as a
9329 monadic value, which is then passed through @code{run-with-store}.
9333 Build the source derivations of the packages, rather than the packages
9336 For instance, @code{guix build -S gcc} returns something like
9337 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
9340 The returned source tarball is the result of applying any patches and
9341 code snippets specified in the package @code{origin} (@pxref{Defining
9344 Note that @command{guix build -S} compiles the sources only of the
9345 specified packages. They do not include the sources of statically
9346 linked dependencies and by themselves are insufficient for reproducing
9350 Fetch and return the source of @var{package-or-derivation} and all their
9351 dependencies, recursively. This is a handy way to obtain a local copy
9352 of all the source code needed to build @var{packages}, allowing you to
9353 eventually build them even without network access. It is an extension
9354 of the @option{--source} option and can accept one of the following
9355 optional argument values:
9359 This value causes the @option{--sources} option to behave in the same way
9360 as the @option{--source} option.
9363 Build the source derivations of all packages, including any source that
9364 might be listed as @code{inputs}. This is the default value.
9367 $ guix build --sources tzdata
9368 The following derivations will be built:
9369 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
9370 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
9374 Build the source derivations of all packages, as well of all transitive
9375 inputs to the packages. This can be used e.g.@: to
9376 prefetch package source for later offline building.
9379 $ guix build --sources=transitive tzdata
9380 The following derivations will be built:
9381 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
9382 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
9383 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
9384 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
9385 /gnu/store/@dots{}-make-4.1.tar.xz.drv
9386 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
9392 @item --system=@var{system}
9393 @itemx -s @var{system}
9394 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
9395 the system type of the build host. The @command{guix build} command allows
9396 you to repeat this option several times, in which case it builds for all the
9397 specified systems; other commands ignore extraneous @option{-s} options.
9400 The @option{--system} flag is for @emph{native} compilation and must not
9401 be confused with cross-compilation. See @option{--target} below for
9402 information on cross-compilation.
9405 An example use of this is on Linux-based systems, which can emulate
9406 different personalities. For instance, passing
9407 @option{--system=i686-linux} on an @code{x86_64-linux} system or
9408 @option{--system=armhf-linux} on an @code{aarch64-linux} system allows
9409 you to build packages in a complete 32-bit environment.
9412 Building for an @code{armhf-linux} system is unconditionally enabled on
9413 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
9414 allow for this functionality, notably the ThunderX.
9417 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
9418 is enabled (@pxref{Virtualization Services,
9419 @code{qemu-binfmt-service-type}}), you can build for any system for
9420 which a QEMU @code{binfmt_misc} handler is installed.
9422 Builds for a system other than that of the machine you are using can
9423 also be offloaded to a remote machine of the right architecture.
9424 @xref{Daemon Offload Setup}, for more information on offloading.
9426 @item --target=@var{triplet}
9427 @cindex cross-compilation
9428 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
9429 as @code{"aarch64-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
9430 configuration triplets,, autoconf, Autoconf}).
9432 @anchor{build-check}
9434 @cindex determinism, checking
9435 @cindex reproducibility, checking
9436 Rebuild @var{package-or-derivation}, which are already available in the
9437 store, and raise an error if the build results are not bit-for-bit
9440 This mechanism allows you to check whether previously installed
9441 substitutes are genuine (@pxref{Substitutes}), or whether the build result
9442 of a package is deterministic. @xref{Invoking guix challenge}, for more
9443 background information and tools.
9445 When used in conjunction with @option{--keep-failed}, the differing
9446 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
9447 This makes it easy to look for differences between the two results.
9450 @cindex repairing store items
9451 @cindex corruption, recovering from
9452 Attempt to repair the specified store items, if they are corrupt, by
9453 re-downloading or rebuilding them.
9455 This operation is not atomic and thus restricted to @code{root}.
9459 Return the derivation paths, not the output paths, of the given
9462 @item --root=@var{file}
9463 @itemx -r @var{file}
9464 @cindex GC roots, adding
9465 @cindex garbage collector roots, adding
9466 Make @var{file} a symlink to the result, and register it as a garbage
9469 Consequently, the results of this @command{guix build} invocation are
9470 protected from garbage collection until @var{file} is removed. When
9471 that option is omitted, build results are eligible for garbage
9472 collection as soon as the build completes. @xref{Invoking guix gc}, for
9476 @cindex build logs, access
9477 Return the build log file names or URLs for the given
9478 @var{package-or-derivation}, or raise an error if build logs are
9481 This works regardless of how packages or derivations are specified. For
9482 instance, the following invocations are equivalent:
9485 guix build --log-file `guix build -d guile`
9486 guix build --log-file `guix build guile`
9487 guix build --log-file guile
9488 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
9491 If a log is unavailable locally, and unless @option{--no-substitutes} is
9492 passed, the command looks for a corresponding log on one of the
9493 substitute servers (as specified with @option{--substitute-urls}).
9495 So for instance, imagine you want to see the build log of GDB on MIPS,
9496 but you are actually on an @code{x86_64} machine:
9499 $ guix build --log-file gdb -s aarch64-linux
9500 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
9503 You can freely access a huge library of build logs!
9506 @node Debugging Build Failures
9507 @subsection Debugging Build Failures
9509 @cindex build failures, debugging
9510 When defining a new package (@pxref{Defining Packages}), you will
9511 probably find yourself spending some time debugging and tweaking the
9512 build until it succeeds. To do that, you need to operate the build
9513 commands yourself in an environment as close as possible to the one the
9516 To that end, the first thing to do is to use the @option{--keep-failed}
9517 or @option{-K} option of @command{guix build}, which will keep the
9518 failed build tree in @file{/tmp} or whatever directory you specified as
9519 @env{TMPDIR} (@pxref{Invoking guix build, @option{--keep-failed}}).
9521 From there on, you can @command{cd} to the failed build tree and source
9522 the @file{environment-variables} file, which contains all the
9523 environment variable definitions that were in place when the build
9524 failed. So let's say you're debugging a build failure in package
9525 @code{foo}; a typical session would look like this:
9529 @dots{} @i{build fails}
9530 $ cd /tmp/guix-build-foo.drv-0
9531 $ source ./environment-variables
9535 Now, you can invoke commands as if you were the daemon (almost) and
9536 troubleshoot your build process.
9538 Sometimes it happens that, for example, a package's tests pass when you
9539 run them manually but they fail when the daemon runs them. This can
9540 happen because the daemon runs builds in containers where, unlike in our
9541 environment above, network access is missing, @file{/bin/sh} does not
9542 exist, etc. (@pxref{Build Environment Setup}).
9544 In such cases, you may need to run inspect the build process from within
9545 a container similar to the one the build daemon creates:
9550 $ cd /tmp/guix-build-foo.drv-0
9551 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
9552 [env]# source ./environment-variables
9556 Here, @command{guix environment -C} creates a container and spawns a new
9557 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
9558 strace gdb} part adds the @command{strace} and @command{gdb} commands to
9559 the container, which you may find handy while debugging. The
9560 @option{--no-grafts} option makes sure we get the exact same
9561 environment, with ungrafted packages (@pxref{Security Updates}, for more
9564 To get closer to a container like that used by the build daemon, we can
9565 remove @file{/bin/sh}:
9571 (Don't worry, this is harmless: this is all happening in the throw-away
9572 container created by @command{guix environment}.)
9574 The @command{strace} command is probably not in the search path, but we
9578 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
9581 In this way, not only you will have reproduced the environment variables
9582 the daemon uses, you will also be running the build process in a container
9583 similar to the one the daemon uses.
9586 @node Invoking guix edit
9587 @section Invoking @command{guix edit}
9589 @cindex @command{guix edit}
9590 @cindex package definition, editing
9591 So many packages, so many source files! The @command{guix edit} command
9592 facilitates the life of users and packagers by pointing their editor at
9593 the source file containing the definition of the specified packages.
9597 guix edit gcc@@4.9 vim
9601 launches the program specified in the @env{VISUAL} or in the
9602 @env{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
9605 If you are using a Guix Git checkout (@pxref{Building from Git}), or
9606 have created your own packages on @env{GUIX_PACKAGE_PATH}
9607 (@pxref{Package Modules}), you will be able to edit the package
9608 recipes. In other cases, you will be able to examine the read-only recipes
9609 for packages currently in the store.
9611 Instead of @env{GUIX_PACKAGE_PATH}, the command-line option
9612 @option{--load-path=@var{directory}} (or in short @option{-L
9613 @var{directory}}) allows you to add @var{directory} to the front of the
9614 package module search path and so make your own packages visible.
9616 @node Invoking guix download
9617 @section Invoking @command{guix download}
9619 @cindex @command{guix download}
9620 @cindex downloading package sources
9621 When writing a package definition, developers typically need to download
9622 a source tarball, compute its SHA256 hash, and write that
9623 hash in the package definition (@pxref{Defining Packages}). The
9624 @command{guix download} tool helps with this task: it downloads a file
9625 from the given URI, adds it to the store, and prints both its file name
9626 in the store and its SHA256 hash.
9628 The fact that the downloaded file is added to the store saves bandwidth:
9629 when the developer eventually tries to build the newly defined package
9630 with @command{guix build}, the source tarball will not have to be
9631 downloaded again because it is already in the store. It is also a
9632 convenient way to temporarily stash files, which may be deleted
9633 eventually (@pxref{Invoking guix gc}).
9635 The @command{guix download} command supports the same URIs as used in
9636 package definitions. In particular, it supports @code{mirror://} URIs.
9637 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
9638 Guile bindings for GnuTLS are available in the user's environment; when
9639 they are not available, an error is raised. @xref{Guile Preparations,
9640 how to install the GnuTLS bindings for Guile,, gnutls-guile,
9641 GnuTLS-Guile}, for more information.
9643 @command{guix download} verifies HTTPS server certificates by loading
9644 the certificates of X.509 authorities from the directory pointed to by
9645 the @env{SSL_CERT_DIR} environment variable (@pxref{X.509
9646 Certificates}), unless @option{--no-check-certificate} is used.
9648 The following options are available:
9651 @item --hash=@var{algorithm}
9652 @itemx -H @var{algorithm}
9653 Compute a hash using the specified @var{algorithm}. @xref{Invoking guix
9654 hash}, for more information.
9656 @item --format=@var{fmt}
9658 Write the hash in the format specified by @var{fmt}. For more
9659 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
9661 @item --no-check-certificate
9662 Do not validate the X.509 certificates of HTTPS servers.
9664 When using this option, you have @emph{absolutely no guarantee} that you
9665 are communicating with the authentic server responsible for the given
9666 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
9668 @item --output=@var{file}
9669 @itemx -o @var{file}
9670 Save the downloaded file to @var{file} instead of adding it to the
9674 @node Invoking guix hash
9675 @section Invoking @command{guix hash}
9677 @cindex @command{guix hash}
9678 The @command{guix hash} command computes the hash of a file.
9679 It is primarily a convenience tool for anyone contributing to the
9680 distribution: it computes the cryptographic hash of a file, which can be
9681 used in the definition of a package (@pxref{Defining Packages}).
9683 The general syntax is:
9686 guix hash @var{option} @var{file}
9689 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
9690 hash of data read from standard input. @command{guix hash} has the
9695 @item --hash=@var{algorithm}
9696 @itemx -H @var{algorithm}
9697 Compute a hash using the specified @var{algorithm}, @code{sha256} by
9700 @var{algorithm} must the name of a cryptographic hash algorithm
9701 supported by Libgcrypt @i{via} Guile-Gcrypt---e.g., @code{sha512} or
9702 @code{sha3-256} (@pxref{Hash Functions,,, guile-gcrypt, Guile-Gcrypt
9705 @item --format=@var{fmt}
9707 Write the hash in the format specified by @var{fmt}.
9709 Supported formats: @code{base64}, @code{nix-base32}, @code{base32}, @code{base16}
9710 (@code{hex} and @code{hexadecimal} can be used as well).
9712 If the @option{--format} option is not specified, @command{guix hash}
9713 will output the hash in @code{nix-base32}. This representation is used
9714 in the definitions of packages.
9718 Compute the hash on @var{file} recursively.
9720 In this case, the hash is computed on an archive containing @var{file},
9721 including its children if it is a directory. Some of the metadata of
9722 @var{file} is part of the archive; for instance, when @var{file} is a
9723 regular file, the hash is different depending on whether @var{file} is
9724 executable or not. Metadata such as time stamps has no impact on the
9725 hash (@pxref{Invoking guix archive}).
9726 @c FIXME: Replace xref above with xref to an ``Archive'' section when
9731 When combined with @option{--recursive}, exclude version control system
9732 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.).
9735 As an example, here is how you would compute the hash of a Git checkout,
9736 which is useful when using the @code{git-fetch} method (@pxref{origin
9740 $ git clone http://example.org/foo.git
9746 @node Invoking guix import
9747 @section Invoking @command{guix import}
9749 @cindex importing packages
9750 @cindex package import
9751 @cindex package conversion
9752 @cindex Invoking @command{guix import}
9753 The @command{guix import} command is useful for people who would like to
9754 add a package to the distribution with as little work as
9755 possible---a legitimate demand. The command knows of a few
9756 repositories from which it can ``import'' package metadata. The result
9757 is a package definition, or a template thereof, in the format we know
9758 (@pxref{Defining Packages}).
9760 The general syntax is:
9763 guix import @var{importer} @var{options}@dots{}
9766 @var{importer} specifies the source from which to import package
9767 metadata, and @var{options} specifies a package identifier and other
9768 options specific to @var{importer}.
9770 Some of the importers rely on the ability to run the @command{gpgv} command.
9771 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
9774 Currently, the available ``importers'' are:
9778 Import metadata for the given GNU package. This provides a template
9779 for the latest version of that GNU package, including the hash of its
9780 source tarball, and its canonical synopsis and description.
9782 Additional information such as the package dependencies and its
9783 license needs to be figured out manually.
9785 For example, the following command returns a package definition for
9789 guix import gnu hello
9792 Specific command-line options are:
9795 @item --key-download=@var{policy}
9796 As for @command{guix refresh}, specify the policy to handle missing
9797 OpenPGP keys when verifying the package signature. @xref{Invoking guix
9798 refresh, @option{--key-download}}.
9803 Import metadata from the @uref{https://pypi.python.org/, Python Package
9804 Index}. Information is taken from the JSON-formatted description
9805 available at @code{pypi.python.org} and usually includes all the relevant
9806 information, including package dependencies. For maximum efficiency, it
9807 is recommended to install the @command{unzip} utility, so that the
9808 importer can unzip Python wheels and gather data from them.
9810 The command below imports metadata for the @code{itsdangerous} Python
9814 guix import pypi itsdangerous
9820 Traverse the dependency graph of the given upstream package recursively
9821 and generate package expressions for all those packages that are not yet
9827 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
9828 is taken from the JSON-formatted description available at
9829 @code{rubygems.org} and includes most relevant information, including
9830 runtime dependencies. There are some caveats, however. The metadata
9831 doesn't distinguish between synopses and descriptions, so the same string
9832 is used for both fields. Additionally, the details of non-Ruby
9833 dependencies required to build native extensions is unavailable and left
9834 as an exercise to the packager.
9836 The command below imports metadata for the @code{rails} Ruby package:
9839 guix import gem rails
9845 Traverse the dependency graph of the given upstream package recursively
9846 and generate package expressions for all those packages that are not yet
9852 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
9853 Information is taken from the JSON-formatted metadata provided through
9854 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
9855 relevant information, such as module dependencies. License information
9856 should be checked closely. If Perl is available in the store, then the
9857 @code{corelist} utility will be used to filter core modules out of the
9858 list of dependencies.
9860 The command command below imports metadata for the Acme::Boolean Perl
9864 guix import cpan Acme::Boolean
9869 @cindex Bioconductor
9870 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
9871 central repository for the @uref{https://r-project.org, GNU@tie{}R
9872 statistical and graphical environment}.
9874 Information is extracted from the @file{DESCRIPTION} file of the package.
9876 The command command below imports metadata for the Cairo R package:
9879 guix import cran Cairo
9882 When @option{--recursive} is added, the importer will traverse the
9883 dependency graph of the given upstream package recursively and generate
9884 package expressions for all those packages that are not yet in Guix.
9886 When @option{--archive=bioconductor} is added, metadata is imported from
9887 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
9888 packages for for the analysis and comprehension of high-throughput
9889 genomic data in bioinformatics.
9891 Information is extracted from the @file{DESCRIPTION} file contained in the
9894 The command below imports metadata for the GenomicRanges R package:
9897 guix import cran --archive=bioconductor GenomicRanges
9900 Finally, you can also import R packages that have not yet been published on
9901 CRAN or Bioconductor as long as they are in a git repository. Use
9902 @option{--archive=git} followed by the URL of the git repository:
9905 guix import cran --archive=git https://github.com/immunogenomics/harmony
9911 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
9912 comprehensive TeX archive network for TeX packages that are part of the
9913 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
9915 Information about the package is obtained through the XML API provided
9916 by CTAN, while the source code is downloaded from the SVN repository of
9917 the Tex Live project. This is done because the CTAN does not keep
9920 The command command below imports metadata for the @code{fontspec}
9924 guix import texlive fontspec
9927 When @option{--archive=@var{directory}} is added, the source code is
9928 downloaded not from the @file{latex} sub-directory of the
9929 @file{texmf-dist/source} tree in the TeX Live SVN repository, but from
9930 the specified sibling @var{directory} under the same root.
9932 The command below imports metadata for the @code{ifxetex} package from
9933 CTAN while fetching the sources from the directory
9934 @file{texmf/source/generic}:
9937 guix import texlive --archive=generic ifxetex
9941 @cindex JSON, import
9942 Import package metadata from a local JSON file. Consider the following
9943 example package definition in JSON format:
9949 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
9950 "build-system": "gnu",
9951 "home-page": "https://www.gnu.org/software/hello/",
9952 "synopsis": "Hello, GNU world: An example GNU package",
9953 "description": "GNU Hello prints a greeting.",
9954 "license": "GPL-3.0+",
9955 "native-inputs": ["gettext"]
9959 The field names are the same as for the @code{<package>} record
9960 (@xref{Defining Packages}). References to other packages are provided
9961 as JSON lists of quoted package specification strings such as
9962 @code{guile} or @code{guile@@2.0}.
9964 The importer also supports a more explicit source definition using the
9965 common fields for @code{<origin>} records:
9971 "method": "url-fetch",
9972 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
9974 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
9981 The command below reads metadata from the JSON file @code{hello.json}
9982 and outputs a package expression:
9985 guix import json hello.json
9989 Import metadata from a local copy of the source of the
9990 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
9991 relies on the @command{nix-instantiate} command of
9992 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
9993 typically written in a mixture of Nix-language and Bash code. This
9994 command only imports the high-level package structure that is written in
9995 the Nix language. It normally includes all the basic fields of a
9998 When importing a GNU package, the synopsis and descriptions are replaced
9999 by their canonical upstream variant.
10001 Usually, you will first need to do:
10004 export NIX_REMOTE=daemon
10008 so that @command{nix-instantiate} does not try to open the Nix database.
10010 As an example, the command below imports the package definition of
10011 LibreOffice (more precisely, it imports the definition of the package
10012 bound to the @code{libreoffice} top-level attribute):
10015 guix import nix ~/path/to/nixpkgs libreoffice
10020 Import metadata from the Haskell community's central package archive
10021 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
10022 Cabal files and includes all the relevant information, including package
10025 Specific command-line options are:
10030 Read a Cabal file from standard input.
10031 @item --no-test-dependencies
10033 Do not include dependencies required only by the test suites.
10034 @item --cabal-environment=@var{alist}
10035 @itemx -e @var{alist}
10036 @var{alist} is a Scheme alist defining the environment in which the
10037 Cabal conditionals are evaluated. The accepted keys are: @code{os},
10038 @code{arch}, @code{impl} and a string representing the name of a flag.
10039 The value associated with a flag has to be either the symbol
10040 @code{true} or @code{false}. The value associated with other keys
10041 has to conform to the Cabal file format definition. The default value
10042 associated with the keys @code{os}, @code{arch} and @code{impl} is
10043 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
10046 Traverse the dependency graph of the given upstream package recursively
10047 and generate package expressions for all those packages that are not yet
10051 The command below imports metadata for the latest version of the
10052 HTTP Haskell package without including test dependencies and
10053 specifying the value of the flag @samp{network-uri} as @code{false}:
10056 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
10059 A specific package version may optionally be specified by following the
10060 package name by an at-sign and a version number as in the following example:
10063 guix import hackage mtl@@2.1.3.1
10068 The @code{stackage} importer is a wrapper around the @code{hackage} one.
10069 It takes a package name, looks up the package version included in a
10070 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
10071 release and uses the @code{hackage} importer to retrieve its metadata.
10072 Note that it is up to you to select an LTS release compatible with the
10073 GHC compiler used by Guix.
10075 Specific command-line options are:
10078 @item --no-test-dependencies
10080 Do not include dependencies required only by the test suites.
10081 @item --lts-version=@var{version}
10082 @itemx -l @var{version}
10083 @var{version} is the desired LTS release version. If omitted the latest
10087 Traverse the dependency graph of the given upstream package recursively
10088 and generate package expressions for all those packages that are not yet
10092 The command below imports metadata for the HTTP Haskell package
10093 included in the LTS Stackage release version 7.18:
10096 guix import stackage --lts-version=7.18 HTTP
10101 Import metadata from an Emacs Lisp Package Archive (ELPA) package
10102 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
10104 Specific command-line options are:
10107 @item --archive=@var{repo}
10108 @itemx -a @var{repo}
10109 @var{repo} identifies the archive repository from which to retrieve the
10110 information. Currently the supported repositories and their identifiers
10114 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
10115 identifier. This is the default.
10117 Packages from @code{elpa.gnu.org} are signed with one of the keys
10118 contained in the GnuPG keyring at
10119 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
10120 @code{emacs} package (@pxref{Package Installation, ELPA package
10121 signatures,, emacs, The GNU Emacs Manual}).
10124 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
10125 @code{melpa-stable} identifier.
10128 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
10134 Traverse the dependency graph of the given upstream package recursively
10135 and generate package expressions for all those packages that are not yet
10141 Import metadata from the crates.io Rust package repository
10142 @uref{https://crates.io, crates.io}, as in this example:
10145 guix import crate blake2-rfc
10148 The crate importer also allows you to specify a version string:
10151 guix import crate constant-time-eq@@0.1.0
10154 Additional options include:
10159 Traverse the dependency graph of the given upstream package recursively
10160 and generate package expressions for all those packages that are not yet
10167 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
10168 repository used by the OCaml community.
10171 The structure of the @command{guix import} code is modular. It would be
10172 useful to have more importers for other package formats, and your help
10173 is welcome here (@pxref{Contributing}).
10175 @node Invoking guix refresh
10176 @section Invoking @command{guix refresh}
10178 @cindex @command {guix refresh}
10179 The primary audience of the @command{guix refresh} command is developers
10180 of the GNU software distribution. By default, it reports any packages
10181 provided by the distribution that are outdated compared to the latest
10182 upstream version, like this:
10186 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
10187 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
10190 Alternatively, one can specify packages to consider, in which case a
10191 warning is emitted for packages that lack an updater:
10194 $ guix refresh coreutils guile guile-ssh
10195 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
10196 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
10199 @command{guix refresh} browses the upstream repository of each package and determines
10200 the highest version number of the releases therein. The command
10201 knows how to update specific types of packages: GNU packages, ELPA
10202 packages, etc.---see the documentation for @option{--type} below. There
10203 are many packages, though, for which it lacks a method to determine
10204 whether a new upstream release is available. However, the mechanism is
10205 extensible, so feel free to get in touch with us to add a new method!
10210 Consider the packages specified, and all the packages upon which they depend.
10213 $ guix refresh --recursive coreutils
10214 gnu/packages/acl.scm:35:2: warning: no updater for acl
10215 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
10216 gnu/packages/xml.scm:68:2: warning: no updater for expat
10217 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
10223 Sometimes the upstream name differs from the package name used in Guix,
10224 and @command{guix refresh} needs a little help. Most updaters honor the
10225 @code{upstream-name} property in package definitions, which can be used
10229 (define-public network-manager
10231 (name "network-manager")
10233 (properties '((upstream-name . "NetworkManager")))))
10236 When passed @option{--update}, it modifies distribution source files to
10237 update the version numbers and source tarball hashes of those package
10238 recipes (@pxref{Defining Packages}). This is achieved by downloading
10239 each package's latest source tarball and its associated OpenPGP
10240 signature, authenticating the downloaded tarball against its signature
10241 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
10242 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
10245 key used to sign the tarball is missing from the user's keyring, an
10246 attempt is made to automatically retrieve it from a public key server;
10247 when this is successful, the key is added to the user's keyring; otherwise,
10248 @command{guix refresh} reports an error.
10250 The following options are supported:
10254 @item --expression=@var{expr}
10255 @itemx -e @var{expr}
10256 Consider the package @var{expr} evaluates to.
10258 This is useful to precisely refer to a package, as in this example:
10261 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
10264 This command lists the dependents of the ``final'' libc (essentially all
10269 Update distribution source files (package recipes) in place. This is
10270 usually run from a checkout of the Guix source tree (@pxref{Running
10271 Guix Before It Is Installed}):
10274 $ ./pre-inst-env guix refresh -s non-core -u
10277 @xref{Defining Packages}, for more information on package definitions.
10279 @item --select=[@var{subset}]
10280 @itemx -s @var{subset}
10281 Select all the packages in @var{subset}, one of @code{core} or
10284 The @code{core} subset refers to all the packages at the core of the
10285 distribution---i.e., packages that are used to build ``everything
10286 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
10287 changing one of these packages in the distribution entails a rebuild of
10288 all the others. Thus, such updates are an inconvenience to users in
10289 terms of build time or bandwidth used to achieve the upgrade.
10291 The @code{non-core} subset refers to the remaining packages. It is
10292 typically useful in cases where an update of the core packages would be
10295 @item --manifest=@var{file}
10296 @itemx -m @var{file}
10297 Select all the packages from the manifest in @var{file}. This is useful to
10298 check if any packages of the user manifest can be updated.
10300 @item --type=@var{updater}
10301 @itemx -t @var{updater}
10302 Select only packages handled by @var{updater} (may be a comma-separated
10303 list of updaters). Currently, @var{updater} may be one of:
10307 the updater for GNU packages;
10309 the updater for packages hosted at @uref{https://savannah.gnu.org, Savannah};
10311 the updater for GNOME packages;
10313 the updater for KDE packages;
10315 the updater for X.org packages;
10317 the updater for packages hosted on kernel.org;
10319 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
10321 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
10323 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
10325 the updater for @uref{https://www.cpan.org/, CPAN} packages;
10327 the updater for @uref{https://pypi.python.org, PyPI} packages.
10329 the updater for @uref{https://rubygems.org, RubyGems} packages.
10331 the updater for @uref{https://github.com, GitHub} packages.
10333 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
10335 the updater for @uref{https://www.stackage.org, Stackage} packages.
10337 the updater for @uref{https://crates.io, Crates} packages.
10339 the updater for @uref{https://launchpad.net, Launchpad} packages.
10342 For instance, the following command only checks for updates of Emacs
10343 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
10346 $ guix refresh --type=elpa,cran
10347 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
10348 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
10353 In addition, @command{guix refresh} can be passed one or more package
10354 names, as in this example:
10357 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
10361 The command above specifically updates the @code{emacs} and
10362 @code{idutils} packages. The @option{--select} option would have no
10363 effect in this case.
10365 When considering whether to upgrade a package, it is sometimes
10366 convenient to know which packages would be affected by the upgrade and
10367 should be checked for compatibility. For this the following option may
10368 be used when passing @command{guix refresh} one or more package names:
10372 @item --list-updaters
10374 List available updaters and exit (see @option{--type} above).
10376 For each updater, display the fraction of packages it covers; at the
10377 end, display the fraction of packages covered by all these updaters.
10379 @item --list-dependent
10381 List top-level dependent packages that would need to be rebuilt as a
10382 result of upgrading one or more packages.
10384 @xref{Invoking guix graph, the @code{reverse-package} type of
10385 @command{guix graph}}, for information on how to visualize the list of
10386 dependents of a package.
10390 Be aware that the @option{--list-dependent} option only
10391 @emph{approximates} the rebuilds that would be required as a result of
10392 an upgrade. More rebuilds might be required under some circumstances.
10395 $ guix refresh --list-dependent flex
10396 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
10397 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
10400 The command above lists a set of packages that could be built to check
10401 for compatibility with an upgraded @code{flex} package.
10405 @item --list-transitive
10406 List all the packages which one or more packages depend upon.
10409 $ guix refresh --list-transitive flex
10410 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
10411 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{}
10416 The command above lists a set of packages which, when changed, would cause
10417 @code{flex} to be rebuilt.
10419 The following options can be used to customize GnuPG operation:
10423 @item --gpg=@var{command}
10424 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
10425 for in @code{$PATH}.
10427 @item --keyring=@var{file}
10428 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
10429 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
10430 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
10431 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
10432 information on a tool to manipulate keybox files).
10434 When this option is omitted, @command{guix refresh} uses
10435 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
10436 signing keys. OpenPGP signatures are checked against keys from this keyring;
10437 missing keys are downloaded to this keyring as well (see
10438 @option{--key-download} below).
10440 You can export keys from your default GPG keyring into a keybox file using
10441 commands like this one:
10444 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
10447 Likewise, you can fetch keys to a specific keybox file like this:
10450 gpg --no-default-keyring --keyring mykeyring.kbx \
10451 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
10454 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
10455 Privacy Guard}, for more information on GPG's @option{--keyring} option.
10457 @item --key-download=@var{policy}
10458 Handle missing OpenPGP keys according to @var{policy}, which may be one
10463 Always download missing OpenPGP keys from the key server, and add them
10464 to the user's GnuPG keyring.
10467 Never try to download missing OpenPGP keys. Instead just bail out.
10470 When a package signed with an unknown OpenPGP key is encountered, ask
10471 the user whether to download it or not. This is the default behavior.
10474 @item --key-server=@var{host}
10475 Use @var{host} as the OpenPGP key server when importing a public key.
10477 @item --load-path=@var{directory}
10478 Add @var{directory} to the front of the package module search path
10479 (@pxref{Package Modules}).
10481 This allows users to define their own packages and make them visible to
10482 the command-line tools.
10486 The @code{github} updater uses the
10487 @uref{https://developer.github.com/v3/, GitHub API} to query for new
10488 releases. When used repeatedly e.g.@: when refreshing all packages,
10489 GitHub will eventually refuse to answer any further API requests. By
10490 default 60 API requests per hour are allowed, and a full refresh on all
10491 GitHub packages in Guix requires more than this. Authentication with
10492 GitHub through the use of an API token alleviates these limits. To use
10493 an API token, set the environment variable @env{GUIX_GITHUB_TOKEN} to a
10494 token procured from @uref{https://github.com/settings/tokens} or
10498 @node Invoking guix lint
10499 @section Invoking @command{guix lint}
10501 @cindex @command{guix lint}
10502 @cindex package, checking for errors
10503 The @command{guix lint} command is meant to help package developers avoid
10504 common errors and use a consistent style. It runs a number of checks on
10505 a given set of packages in order to find common mistakes in their
10506 definitions. Available @dfn{checkers} include (see
10507 @option{--list-checkers} for a complete list):
10512 Validate certain typographical and stylistic rules about package
10513 descriptions and synopses.
10515 @item inputs-should-be-native
10516 Identify inputs that should most likely be native inputs.
10522 @itemx source-file-name
10523 Probe @code{home-page} and @code{source} URLs and report those that are
10524 invalid. Suggest a @code{mirror://} URL when applicable. If the
10525 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
10526 URL. Check that the source file name is meaningful, e.g.@: is not just a
10527 version number or ``git-checkout'', without a declared @code{file-name}
10528 (@pxref{origin Reference}).
10530 @item source-unstable-tarball
10531 Parse the @code{source} URL to determine if a tarball from GitHub is
10532 autogenerated or if it is a release tarball. Unfortunately GitHub's
10533 autogenerated tarballs are sometimes regenerated.
10536 Check that the derivation of the given packages can be successfully
10537 computed for all the supported systems (@pxref{Derivations}).
10539 @item profile-collisions
10540 Check whether installing the given packages in a profile would lead to
10541 collisions. Collisions occur when several packages with the same name
10542 but a different version or a different store file name are propagated.
10543 @xref{package Reference, @code{propagated-inputs}}, for more information
10544 on propagated inputs.
10547 @cindex Software Heritage, source code archive
10548 @cindex archival of source code, Software Heritage
10549 Checks whether the package's source code is archived at
10550 @uref{https://www.softwareheritage.org, Software Heritage}.
10552 When the source code that is not archived comes from a version-control system
10553 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
10554 ``save'' request so that it eventually archives it. This ensures that the
10555 source will remain available in the long term, and that Guix can fall back to
10556 Software Heritage should the source code disappear from its original host.
10557 The status of recent ``save'' requests can be
10558 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
10560 When source code is a tarball obtained with @code{url-fetch}, simply print a
10561 message when it is not archived. As of this writing, Software Heritage does
10562 not allow requests to save arbitrary tarballs; we are working on ways to
10563 ensure that non-VCS source code is also archived.
10566 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
10567 request rate per IP address}. When the limit is reached, @command{guix lint}
10568 prints a message and the @code{archival} checker stops doing anything until
10569 that limit has been reset.
10572 @cindex security vulnerabilities
10573 @cindex CVE, Common Vulnerabilities and Exposures
10574 Report known vulnerabilities found in the Common Vulnerabilities and
10575 Exposures (CVE) databases of the current and past year
10576 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
10579 To view information about a particular vulnerability, visit pages such as:
10583 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
10585 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
10589 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
10590 @code{CVE-2015-7554}.
10592 Package developers can specify in package recipes the
10593 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
10594 name and version of the package when they differ from the name or version
10595 that Guix uses, as in this example:
10601 ;; CPE calls this package "grub2".
10602 (properties '((cpe-name . "grub2")
10603 (cpe-version . "2.3"))))
10606 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
10607 Some entries in the CVE database do not specify which version of a
10608 package they apply to, and would thus ``stick around'' forever. Package
10609 developers who found CVE alerts and verified they can be ignored can
10610 declare them as in this example:
10616 ;; These CVEs no longer apply and can be safely ignored.
10617 (properties `((lint-hidden-cve . ("CVE-2011-0433"
10620 "CVE-2011-5244")))))
10624 Warn about obvious source code formatting issues: trailing white space,
10625 use of tabulations, etc.
10628 The general syntax is:
10631 guix lint @var{options} @var{package}@dots{}
10634 If no package is given on the command line, then all packages are checked.
10635 The @var{options} may be zero or more of the following:
10638 @item --list-checkers
10640 List and describe all the available checkers that will be run on packages
10645 Only enable the checkers specified in a comma-separated list using the
10646 names returned by @option{--list-checkers}.
10648 @item --load-path=@var{directory}
10649 @itemx -L @var{directory}
10650 Add @var{directory} to the front of the package module search path
10651 (@pxref{Package Modules}).
10653 This allows users to define their own packages and make them visible to
10654 the command-line tools.
10658 @node Invoking guix size
10659 @section Invoking @command{guix size}
10662 @cindex package size
10664 @cindex @command{guix size}
10665 The @command{guix size} command helps package developers profile the
10666 disk usage of packages. It is easy to overlook the impact of an
10667 additional dependency added to a package, or the impact of using a
10668 single output for a package that could easily be split (@pxref{Packages
10669 with Multiple Outputs}). Such are the typical issues that
10670 @command{guix size} can highlight.
10672 The command can be passed one or more package specifications
10673 such as @code{gcc@@4.8}
10674 or @code{guile:debug}, or a file name in the store. Consider this
10678 $ guix size coreutils
10679 store item total self
10680 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
10681 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
10682 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
10683 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
10684 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
10685 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
10686 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
10687 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
10692 The store items listed here constitute the @dfn{transitive closure} of
10693 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
10694 would be returned by:
10697 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
10700 Here the output shows three columns next to store items. The first column,
10701 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
10702 the store item---that is, its own size plus the size of all its
10703 dependencies. The next column, labeled ``self'', shows the size of the
10704 item itself. The last column shows the ratio of the size of the item
10705 itself to the space occupied by all the items listed here.
10707 In this example, we see that the closure of Coreutils weighs in at
10708 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
10709 libraries. (That libc and GCC's libraries represent a large fraction of
10710 the closure is not a problem @i{per se} because they are always available
10711 on the system anyway.)
10713 Since the command also accepts store file names, assessing the size of
10714 a build result is straightforward:
10717 guix size $(guix system build config.scm)
10720 When the package(s) passed to @command{guix size} are available in the
10721 store@footnote{More precisely, @command{guix size} looks for the
10722 @emph{ungrafted} variant of the given package(s), as returned by
10723 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
10724 for information on grafts.}, @command{guix size} queries the daemon to determine its
10725 dependencies, and measures its size in the store, similar to @command{du
10726 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
10729 When the given packages are @emph{not} in the store, @command{guix size}
10730 reports information based on the available substitutes
10731 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
10732 store items that are not even on disk, only available remotely.
10734 You can also specify several package names:
10737 $ guix size coreutils grep sed bash
10738 store item total self
10739 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
10740 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
10741 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
10742 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
10748 In this example we see that the combination of the four packages takes
10749 102.3@tie{}MiB in total, which is much less than the sum of each closure
10750 since they have a lot of dependencies in common.
10752 When looking at the profile returned by @command{guix size}, you may
10753 find yourself wondering why a given package shows up in the profile at
10754 all. To understand it, you can use @command{guix graph --path -t
10755 references} to display the shortest path between the two packages
10756 (@pxref{Invoking guix graph}).
10758 The available options are:
10762 @item --substitute-urls=@var{urls}
10763 Use substitute information from @var{urls}.
10764 @xref{client-substitute-urls, the same option for @code{guix build}}.
10766 @item --sort=@var{key}
10767 Sort lines according to @var{key}, one of the following options:
10771 the size of each item (the default);
10773 the total size of the item's closure.
10776 @item --map-file=@var{file}
10777 Write a graphical map of disk usage in PNG format to @var{file}.
10779 For the example above, the map looks like this:
10781 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
10782 produced by @command{guix size}}
10784 This option requires that
10785 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
10786 installed and visible in Guile's module search path. When that is not
10787 the case, @command{guix size} fails as it tries to load it.
10789 @item --system=@var{system}
10790 @itemx -s @var{system}
10791 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
10793 @item --load-path=@var{directory}
10794 @itemx -L @var{directory}
10795 Add @var{directory} to the front of the package module search path
10796 (@pxref{Package Modules}).
10798 This allows users to define their own packages and make them visible to
10799 the command-line tools.
10802 @node Invoking guix graph
10803 @section Invoking @command{guix graph}
10806 @cindex @command{guix graph}
10807 @cindex package dependencies
10808 Packages and their dependencies form a @dfn{graph}, specifically a
10809 directed acyclic graph (DAG). It can quickly become difficult to have a
10810 mental model of the package DAG, so the @command{guix graph} command
10811 provides a visual representation of the DAG. By default,
10812 @command{guix graph} emits a DAG representation in the input format of
10813 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
10814 directly to the @command{dot} command of Graphviz. It can also emit an
10815 HTML page with embedded JavaScript code to display a ``chord diagram''
10816 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
10817 emit Cypher queries to construct a graph in a graph database supporting
10818 the @uref{https://www.opencypher.org/, openCypher} query language. With
10819 @option{--path}, it simply displays the shortest path between two
10820 packages. The general syntax is:
10823 guix graph @var{options} @var{package}@dots{}
10826 For example, the following command generates a PDF file representing the
10827 package DAG for the GNU@tie{}Core Utilities, showing its build-time
10831 guix graph coreutils | dot -Tpdf > dag.pdf
10834 The output looks like this:
10836 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
10838 Nice little graph, no?
10840 You may find it more pleasant to navigate the graph interactively with
10841 @command{xdot} (from the @code{xdot} package):
10844 guix graph coreutils | xdot -
10847 But there is more than one graph! The one above is concise: it is the
10848 graph of package objects, omitting implicit inputs such as GCC, libc,
10849 grep, etc. It is often useful to have such a concise graph, but
10850 sometimes one may want to see more details. @command{guix graph} supports
10851 several types of graphs, allowing you to choose the level of detail:
10855 This is the default type used in the example above. It shows the DAG of
10856 package objects, excluding implicit dependencies. It is concise, but
10857 filters out many details.
10859 @item reverse-package
10860 This shows the @emph{reverse} DAG of packages. For example:
10863 guix graph --type=reverse-package ocaml
10866 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
10867 you are also interested in cases where OCaml is an implicit dependency, see
10868 @code{reverse-bag} below).
10870 Note that for core packages this can yield huge graphs. If all you want
10871 is to know the number of packages that depend on a given package, use
10872 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
10873 @option{--list-dependent}}).
10876 This is the package DAG, @emph{including} implicit inputs.
10878 For instance, the following command:
10881 guix graph --type=bag-emerged coreutils
10884 ...@: yields this bigger graph:
10886 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
10888 At the bottom of the graph, we see all the implicit inputs of
10889 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
10891 Now, note that the dependencies of these implicit inputs---that is, the
10892 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
10893 here, for conciseness.
10896 Similar to @code{bag-emerged}, but this time including all the bootstrap
10899 @item bag-with-origins
10900 Similar to @code{bag}, but also showing origins and their dependencies.
10903 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
10904 it also takes implicit dependencies into account. For example:
10907 guix graph -t reverse-bag dune
10911 ...@: yields the graph of all packages that depend on Dune, directly or
10912 indirectly. Since Dune is an @emph{implicit} dependency of many packages
10913 @i{via} @code{dune-build-system}, this shows a large number of packages,
10914 whereas @code{reverse-package} would show very few if any.
10917 This is the most detailed representation: It shows the DAG of
10918 derivations (@pxref{Derivations}) and plain store items. Compared to
10919 the above representation, many additional nodes are visible, including
10920 build scripts, patches, Guile modules, etc.
10922 For this type of graph, it is also possible to pass a @file{.drv} file
10923 name instead of a package name, as in:
10926 guix graph -t derivation `guix system build -d my-config.scm`
10930 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
10931 For example, the following command shows the graph for the package
10932 module that defines the @code{guile} package:
10935 guix graph -t module guile | xdot -
10939 All the types above correspond to @emph{build-time dependencies}. The
10940 following graph type represents the @emph{run-time dependencies}:
10944 This is the graph of @dfn{references} of a package output, as returned
10945 by @command{guix gc --references} (@pxref{Invoking guix gc}).
10947 If the given package output is not available in the store, @command{guix
10948 graph} attempts to obtain dependency information from substitutes.
10950 Here you can also pass a store file name instead of a package name. For
10951 example, the command below produces the reference graph of your profile
10952 (which can be big!):
10955 guix graph -t references `readlink -f ~/.guix-profile`
10959 This is the graph of the @dfn{referrers} of a store item, as returned by
10960 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
10962 This relies exclusively on local information from your store. For
10963 instance, let us suppose that the current Inkscape is available in 10
10964 profiles on your machine; @command{guix graph -t referrers inkscape}
10965 will show a graph rooted at Inkscape and with those 10 profiles linked
10968 It can help determine what is preventing a store item from being garbage
10973 @cindex shortest path, between packages
10974 Often, the graph of the package you are interested in does not fit on
10975 your screen, and anyway all you want to know is @emph{why} that package
10976 actually depends on some seemingly unrelated package. The
10977 @option{--path} option instructs @command{guix graph} to display the
10978 shortest path between two packages (or derivations, or store items,
10982 $ guix graph --path emacs libunistring
10985 libunistring@@0.9.10
10986 $ guix graph --path -t derivation emacs libunistring
10987 /gnu/store/@dots{}-emacs-26.3.drv
10988 /gnu/store/@dots{}-mailutils-3.9.drv
10989 /gnu/store/@dots{}-libunistring-0.9.10.drv
10990 $ guix graph --path -t references emacs libunistring
10991 /gnu/store/@dots{}-emacs-26.3
10992 /gnu/store/@dots{}-libidn2-2.2.0
10993 /gnu/store/@dots{}-libunistring-0.9.10
10996 The available options are the following:
10999 @item --type=@var{type}
11000 @itemx -t @var{type}
11001 Produce a graph output of @var{type}, where @var{type} must be one of
11002 the values listed above.
11005 List the supported graph types.
11007 @item --backend=@var{backend}
11008 @itemx -b @var{backend}
11009 Produce a graph using the selected @var{backend}.
11011 @item --list-backends
11012 List the supported graph backends.
11014 Currently, the available backends are Graphviz and d3.js.
11017 Display the shortest path between two nodes of the type specified by
11018 @option{--type}. The example below shows the shortest path between
11019 @code{libreoffice} and @code{llvm} according to the references of
11020 @code{libreoffice}:
11023 $ guix graph --path -t references libreoffice llvm
11024 /gnu/store/@dots{}-libreoffice-6.4.2.2
11025 /gnu/store/@dots{}-libepoxy-1.5.4
11026 /gnu/store/@dots{}-mesa-19.3.4
11027 /gnu/store/@dots{}-llvm-9.0.1
11030 @item --expression=@var{expr}
11031 @itemx -e @var{expr}
11032 Consider the package @var{expr} evaluates to.
11034 This is useful to precisely refer to a package, as in this example:
11037 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
11040 @item --system=@var{system}
11041 @itemx -s @var{system}
11042 Display the graph for @var{system}---e.g., @code{i686-linux}.
11044 The package dependency graph is largely architecture-independent, but there
11045 are some architecture-dependent bits that this option allows you to visualize.
11047 @item --load-path=@var{directory}
11048 @itemx -L @var{directory}
11049 Add @var{directory} to the front of the package module search path
11050 (@pxref{Package Modules}).
11052 This allows users to define their own packages and make them visible to
11053 the command-line tools.
11056 On top of that, @command{guix graph} supports all the usual package
11057 transformation options (@pxref{Package Transformation Options}). This
11058 makes it easy to view the effect of a graph-rewriting transformation
11059 such as @option{--with-input}. For example, the command below outputs
11060 the graph of @code{git} once @code{openssl} has been replaced by
11061 @code{libressl} everywhere in the graph:
11064 guix graph git --with-input=openssl=libressl
11067 So many possibilities, so much fun!
11069 @node Invoking guix publish
11070 @section Invoking @command{guix publish}
11072 @cindex @command{guix publish}
11073 The purpose of @command{guix publish} is to enable users to easily share
11074 their store with others, who can then use it as a substitute server
11075 (@pxref{Substitutes}).
11077 When @command{guix publish} runs, it spawns an HTTP server which allows
11078 anyone with network access to obtain substitutes from it. This means
11079 that any machine running Guix can also act as if it were a build farm,
11080 since the HTTP interface is compatible with Cuirass, the software behind
11081 the @code{@value{SUBSTITUTE-SERVER}} build farm.
11083 For security, each substitute is signed, allowing recipients to check
11084 their authenticity and integrity (@pxref{Substitutes}). Because
11085 @command{guix publish} uses the signing key of the system, which is only
11086 readable by the system administrator, it must be started as root; the
11087 @option{--user} option makes it drop root privileges early on.
11089 The signing key pair must be generated before @command{guix publish} is
11090 launched, using @command{guix archive --generate-key} (@pxref{Invoking
11093 The general syntax is:
11096 guix publish @var{options}@dots{}
11099 Running @command{guix publish} without any additional arguments will
11100 spawn an HTTP server on port 8080:
11106 Once a publishing server has been authorized (@pxref{Invoking guix
11107 archive}), the daemon may download substitutes from it:
11110 guix-daemon --substitute-urls=http://example.org:8080
11113 By default, @command{guix publish} compresses archives on the fly as it
11114 serves them. This ``on-the-fly'' mode is convenient in that it requires
11115 no setup and is immediately available. However, when serving lots of
11116 clients, we recommend using the @option{--cache} option, which enables
11117 caching of the archives before they are sent to clients---see below for
11118 details. The @command{guix weather} command provides a handy way to
11119 check what a server provides (@pxref{Invoking guix weather}).
11121 As a bonus, @command{guix publish} also serves as a content-addressed
11122 mirror for source files referenced in @code{origin} records
11123 (@pxref{origin Reference}). For instance, assuming @command{guix
11124 publish} is running on @code{example.org}, the following URL returns the
11125 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
11126 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
11129 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
11132 Obviously, these URLs only work for files that are in the store; in
11133 other cases, they return 404 (``Not Found'').
11135 @cindex build logs, publication
11136 Build logs are available from @code{/log} URLs like:
11139 http://example.org/log/gwspk@dots{}-guile-2.2.3
11143 When @command{guix-daemon} is configured to save compressed build logs,
11144 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
11145 URLs return the compressed log as-is, with an appropriate
11146 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
11147 running @command{guix-daemon} with @option{--log-compression=gzip} since
11148 Web browsers can automatically decompress it, which is not the case with
11151 The following options are available:
11154 @item --port=@var{port}
11155 @itemx -p @var{port}
11156 Listen for HTTP requests on @var{port}.
11158 @item --listen=@var{host}
11159 Listen on the network interface for @var{host}. The default is to
11160 accept connections from any interface.
11162 @item --user=@var{user}
11163 @itemx -u @var{user}
11164 Change privileges to @var{user} as soon as possible---i.e., once the
11165 server socket is open and the signing key has been read.
11167 @item --compression[=@var{method}[:@var{level}]]
11168 @itemx -C [@var{method}[:@var{level}]]
11169 Compress data using the given @var{method} and @var{level}. @var{method} is
11170 one of @code{lzip} and @code{gzip}; when @var{method} is omitted, @code{gzip}
11173 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
11174 to different compression levels: 1 is the fastest, and 9 is the best
11175 (CPU-intensive). The default is 3.
11177 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a small
11178 increase in CPU usage; see
11179 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip Web
11182 Unless @option{--cache} is used, compression occurs on the fly and
11183 the compressed streams are not
11184 cached. Thus, to reduce load on the machine that runs @command{guix
11185 publish}, it may be a good idea to choose a low compression level, to
11186 run @command{guix publish} behind a caching proxy, or to use
11187 @option{--cache}. Using @option{--cache} has the advantage that it
11188 allows @command{guix publish} to add @code{Content-Length} HTTP header
11191 This option can be repeated, in which case every substitute gets compressed
11192 using all the selected methods, and all of them are advertised. This is
11193 useful when users may not support all the compression methods: they can select
11194 the one they support.
11196 @item --cache=@var{directory}
11197 @itemx -c @var{directory}
11198 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
11199 and only serve archives that are in cache.
11201 When this option is omitted, archives and meta-data are created
11202 on-the-fly. This can reduce the available bandwidth, especially when
11203 compression is enabled, since this may become CPU-bound. Another
11204 drawback of the default mode is that the length of archives is not known
11205 in advance, so @command{guix publish} does not add a
11206 @code{Content-Length} HTTP header to its responses, which in turn
11207 prevents clients from knowing the amount of data being downloaded.
11209 Conversely, when @option{--cache} is used, the first request for a store
11210 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
11211 background process to @dfn{bake} the archive---computing its
11212 @code{.narinfo} and compressing the archive, if needed. Once the
11213 archive is cached in @var{directory}, subsequent requests succeed and
11214 are served directly from the cache, which guarantees that clients get
11215 the best possible bandwidth.
11217 The ``baking'' process is performed by worker threads. By default, one
11218 thread per CPU core is created, but this can be customized. See
11219 @option{--workers} below.
11221 When @option{--ttl} is used, cached entries are automatically deleted
11222 when they have expired.
11224 @item --workers=@var{N}
11225 When @option{--cache} is used, request the allocation of @var{N} worker
11226 threads to ``bake'' archives.
11228 @item --ttl=@var{ttl}
11229 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
11230 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
11231 days, @code{1m} means 1 month, and so on.
11233 This allows the user's Guix to keep substitute information in cache for
11234 @var{ttl}. However, note that @code{guix publish} does not itself
11235 guarantee that the store items it provides will indeed remain available
11236 for as long as @var{ttl}.
11238 Additionally, when @option{--cache} is used, cached entries that have
11239 not been accessed for @var{ttl} and that no longer have a corresponding
11240 item in the store, may be deleted.
11242 @item --nar-path=@var{path}
11243 Use @var{path} as the prefix for the URLs of ``nar'' files
11244 (@pxref{Invoking guix archive, normalized archives}).
11246 By default, nars are served at a URL such as
11247 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
11248 change the @code{/nar} part to @var{path}.
11250 @item --public-key=@var{file}
11251 @itemx --private-key=@var{file}
11252 Use the specific @var{file}s as the public/private key pair used to sign
11253 the store items being published.
11255 The files must correspond to the same key pair (the private key is used
11256 for signing and the public key is merely advertised in the signature
11257 metadata). They must contain keys in the canonical s-expression format
11258 as produced by @command{guix archive --generate-key} (@pxref{Invoking
11259 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
11260 @file{/etc/guix/signing-key.sec} are used.
11262 @item --repl[=@var{port}]
11263 @itemx -r [@var{port}]
11264 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
11265 Reference Manual}) on @var{port} (37146 by default). This is used
11266 primarily for debugging a running @command{guix publish} server.
11269 Enabling @command{guix publish} on Guix System is a one-liner: just
11270 instantiate a @code{guix-publish-service-type} service in the @code{services} field
11271 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
11272 @code{guix-publish-service-type}}).
11274 If you are instead running Guix on a ``foreign distro'', follow these
11279 If your host distro uses the systemd init system:
11282 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
11283 /etc/systemd/system/
11284 # systemctl start guix-publish && systemctl enable guix-publish
11288 If your host distro uses the Upstart init system:
11291 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
11292 # start guix-publish
11296 Otherwise, proceed similarly with your distro's init system.
11299 @node Invoking guix challenge
11300 @section Invoking @command{guix challenge}
11302 @cindex reproducible builds
11303 @cindex verifiable builds
11304 @cindex @command{guix challenge}
11306 Do the binaries provided by this server really correspond to the source
11307 code it claims to build? Is a package build process deterministic?
11308 These are the questions the @command{guix challenge} command attempts to
11311 The former is obviously an important question: Before using a substitute
11312 server (@pxref{Substitutes}), one had better @emph{verify} that it
11313 provides the right binaries, and thus @emph{challenge} it. The latter
11314 is what enables the former: If package builds are deterministic, then
11315 independent builds of the package should yield the exact same result,
11316 bit for bit; if a server provides a binary different from the one
11317 obtained locally, it may be either corrupt or malicious.
11319 We know that the hash that shows up in @file{/gnu/store} file names is
11320 the hash of all the inputs of the process that built the file or
11321 directory---compilers, libraries, build scripts,
11322 etc. (@pxref{Introduction}). Assuming deterministic build processes,
11323 one store file name should map to exactly one build output.
11324 @command{guix challenge} checks whether there is, indeed, a single
11325 mapping by comparing the build outputs of several independent builds of
11326 any given store item.
11328 The command output looks like this:
11331 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
11332 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
11333 updating list of substitutes from 'https://guix.example.org'... 100.0%
11334 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
11335 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
11336 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
11337 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
11339 /lib/libcrypto.so.1.1
11342 /gnu/store/@dots{}-git-2.5.0 contents differ:
11343 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
11344 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
11345 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
11347 /libexec/git-core/git-fsck
11349 /gnu/store/@dots{}-pius-2.1.1 contents differ:
11350 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
11351 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
11352 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
11354 /share/man/man1/pius.1.gz
11358 6,406 store items were analyzed:
11359 - 4,749 (74.1%) were identical
11360 - 525 (8.2%) differed
11361 - 1,132 (17.7%) were inconclusive
11365 In this example, @command{guix challenge} first scans the store to
11366 determine the set of locally-built derivations---as opposed to store
11367 items that were downloaded from a substitute server---and then queries
11368 all the substitute servers. It then reports those store items for which
11369 the servers obtained a result different from the local build.
11371 @cindex non-determinism, in package builds
11372 As an example, @code{guix.example.org} always gets a different answer.
11373 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
11374 case of Git. This might indicate that the build process of Git is
11375 non-deterministic, meaning that its output varies as a function of
11376 various things that Guix does not fully control, in spite of building
11377 packages in isolated environments (@pxref{Features}). Most common
11378 sources of non-determinism include the addition of timestamps in build
11379 results, the inclusion of random numbers, and directory listings sorted
11380 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
11383 To find out what is wrong with this Git binary, the easiest approach is
11387 guix challenge git \
11388 --diff=diffoscope \
11389 --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
11392 This automatically invokes @command{diffoscope}, which displays detailed
11393 information about files that differ.
11395 Alternatively, we can do something along these lines (@pxref{Invoking guix
11399 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-git-2.5.0 \
11400 | lzip -d | guix archive -x /tmp/git
11401 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
11404 This command shows the difference between the files resulting from the
11405 local build, and the files resulting from the build on
11406 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
11407 diffutils, Comparing and Merging Files}). The @command{diff} command
11408 works great for text files. When binary files differ, a better option
11409 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
11410 visualize differences for all kinds of files.
11412 Once you have done that work, you can tell whether the differences are due
11413 to a non-deterministic build process or to a malicious server. We try
11414 hard to remove sources of non-determinism in packages to make it easier
11415 to verify substitutes, but of course, this is a process that
11416 involves not just Guix, but a large part of the free software community.
11417 In the meantime, @command{guix challenge} is one tool to help address
11420 If you are writing packages for Guix, you are encouraged to check
11421 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
11422 same build result as you did with:
11425 $ guix challenge @var{package}
11429 where @var{package} is a package specification such as
11430 @code{guile@@2.0} or @code{glibc:debug}.
11432 The general syntax is:
11435 guix challenge @var{options} [@var{packages}@dots{}]
11438 When a difference is found between the hash of a locally-built item and
11439 that of a server-provided substitute, or among substitutes provided by
11440 different servers, the command displays it as in the example above and
11441 its exit code is 2 (other non-zero exit codes denote other kinds of
11444 The one option that matters is:
11448 @item --substitute-urls=@var{urls}
11449 Consider @var{urls} the whitespace-separated list of substitute source
11450 URLs to compare to.
11452 @item --diff=@var{mode}
11453 Upon mismatches, show differences according to @var{mode}, one of:
11456 @item @code{simple} (the default)
11457 Show the list of files that differ.
11459 @item @code{diffoscope}
11460 @itemx @var{command}
11461 Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
11462 two directories whose contents do not match.
11464 When @var{command} is an absolute file name, run @var{command} instead
11468 Do not show further details about the differences.
11471 Thus, unless @option{--diff=none} is passed, @command{guix challenge}
11472 downloads the store items from the given substitute servers so that it
11477 Show details about matches (identical contents) in addition to
11478 information about mismatches.
11482 @node Invoking guix copy
11483 @section Invoking @command{guix copy}
11485 @cindex copy, of store items, over SSH
11486 @cindex SSH, copy of store items
11487 @cindex sharing store items across machines
11488 @cindex transferring store items across machines
11489 The @command{guix copy} command copies items from the store of one
11490 machine to that of another machine over a secure shell (SSH)
11491 connection@footnote{This command is available only when Guile-SSH was
11492 found. @xref{Requirements}, for details.}. For example, the following
11493 command copies the @code{coreutils} package, the user's profile, and all
11494 their dependencies over to @var{host}, logged in as @var{user}:
11497 guix copy --to=@var{user}@@@var{host} \
11498 coreutils `readlink -f ~/.guix-profile`
11501 If some of the items to be copied are already present on @var{host},
11502 they are not actually sent.
11504 The command below retrieves @code{libreoffice} and @code{gimp} from
11505 @var{host}, assuming they are available there:
11508 guix copy --from=@var{host} libreoffice gimp
11511 The SSH connection is established using the Guile-SSH client, which is
11512 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
11513 @file{~/.ssh/config}, and uses the SSH agent for authentication.
11515 The key used to sign items that are sent must be accepted by the remote
11516 machine. Likewise, the key used by the remote machine to sign items you
11517 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
11518 own daemon. @xref{Invoking guix archive}, for more information about
11519 store item authentication.
11521 The general syntax is:
11524 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
11527 You must always specify one of the following options:
11530 @item --to=@var{spec}
11531 @itemx --from=@var{spec}
11532 Specify the host to send to or receive from. @var{spec} must be an SSH
11533 spec such as @code{example.org}, @code{charlie@@example.org}, or
11534 @code{charlie@@example.org:2222}.
11537 The @var{items} can be either package names, such as @code{gimp}, or
11538 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
11540 When specifying the name of a package to send, it is first built if
11541 needed, unless @option{--dry-run} was specified. Common build options
11542 are supported (@pxref{Common Build Options}).
11545 @node Invoking guix container
11546 @section Invoking @command{guix container}
11548 @cindex @command{guix container}
11550 As of version @value{VERSION}, this tool is experimental. The interface
11551 is subject to radical change in the future.
11554 The purpose of @command{guix container} is to manipulate processes
11555 running within an isolated environment, commonly known as a
11556 ``container'', typically created by the @command{guix environment}
11557 (@pxref{Invoking guix environment}) and @command{guix system container}
11558 (@pxref{Invoking guix system}) commands.
11560 The general syntax is:
11563 guix container @var{action} @var{options}@dots{}
11566 @var{action} specifies the operation to perform with a container, and
11567 @var{options} specifies the context-specific arguments for the action.
11569 The following actions are available:
11573 Execute a command within the context of a running container.
11578 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
11581 @var{pid} specifies the process ID of the running container.
11582 @var{program} specifies an executable file name within the root file
11583 system of the container. @var{arguments} are the additional options that
11584 will be passed to @var{program}.
11586 The following command launches an interactive login shell inside a
11587 Guix system container, started by @command{guix system container}, and whose
11588 process ID is 9001:
11591 guix container exec 9001 /run/current-system/profile/bin/bash --login
11594 Note that the @var{pid} cannot be the parent process of a container. It
11595 must be PID 1 of the container or one of its child processes.
11599 @node Invoking guix weather
11600 @section Invoking @command{guix weather}
11602 Occasionally you're grumpy because substitutes are lacking and you end
11603 up building packages by yourself (@pxref{Substitutes}). The
11604 @command{guix weather} command reports on substitute availability on the
11605 specified servers so you can have an idea of whether you'll be grumpy
11606 today. It can sometimes be useful info as a user, but it is primarily
11607 useful to people running @command{guix publish} (@pxref{Invoking guix
11610 @cindex statistics, for substitutes
11611 @cindex availability of substitutes
11612 @cindex substitute availability
11613 @cindex weather, substitute availability
11614 Here's a sample run:
11617 $ guix weather --substitute-urls=https://guix.example.org
11618 computing 5,872 package derivations for x86_64-linux...
11619 looking for 6,128 store items on https://guix.example.org..
11620 updating list of substitutes from 'https://guix.example.org'... 100.0%
11621 https://guix.example.org
11622 43.4% substitutes available (2,658 out of 6,128)
11623 7,032.5 MiB of nars (compressed)
11624 19,824.2 MiB on disk (uncompressed)
11625 0.030 seconds per request (182.9 seconds in total)
11626 33.5 requests per second
11628 9.8% (342 out of 3,470) of the missing items are queued
11630 x86_64-linux: 518 (59.7%)
11631 i686-linux: 221 (25.5%)
11632 aarch64-linux: 128 (14.8%)
11633 build rate: 23.41 builds per hour
11634 x86_64-linux: 11.16 builds per hour
11635 i686-linux: 6.03 builds per hour
11636 aarch64-linux: 6.41 builds per hour
11639 @cindex continuous integration, statistics
11640 As you can see, it reports the fraction of all the packages for which
11641 substitutes are available on the server---regardless of whether
11642 substitutes are enabled, and regardless of whether this server's signing
11643 key is authorized. It also reports the size of the compressed archives
11644 (``nars'') provided by the server, the size the corresponding store
11645 items occupy in the store (assuming deduplication is turned off), and
11646 the server's throughput. The second part gives continuous integration
11647 (CI) statistics, if the server supports it. In addition, using the
11648 @option{--coverage} option, @command{guix weather} can list ``important''
11649 package substitutes missing on the server (see below).
11651 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
11652 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
11653 challenge}, it ignores signatures on those substitutes, which is
11654 innocuous since the command only gathers statistics and cannot install
11657 The general syntax is:
11660 guix weather @var{options}@dots{} [@var{packages}@dots{}]
11663 When @var{packages} is omitted, @command{guix weather} checks the availability
11664 of substitutes for @emph{all} the packages, or for those specified with
11665 @option{--manifest}; otherwise it only considers the specified packages. It
11666 is also possible to query specific system types with @option{--system}.
11667 @command{guix weather} exits with a non-zero code when the fraction of
11668 available substitutes is below 100%.
11670 The available options are listed below.
11673 @item --substitute-urls=@var{urls}
11674 @var{urls} is the space-separated list of substitute server URLs to
11675 query. When this option is omitted, the default set of substitute
11676 servers is queried.
11678 @item --system=@var{system}
11679 @itemx -s @var{system}
11680 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
11681 option can be repeated, in which case @command{guix weather} will query
11682 substitutes for several system types.
11684 @item --manifest=@var{file}
11685 Instead of querying substitutes for all the packages, only ask for those
11686 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
11687 with the @code{-m} option of @command{guix package} (@pxref{Invoking
11690 This option can be repeated several times, in which case the manifests
11693 @item --coverage[=@var{count}]
11694 @itemx -c [@var{count}]
11695 Report on substitute coverage for packages: list packages with at least
11696 @var{count} dependents (zero by default) for which substitutes are
11697 unavailable. Dependent packages themselves are not listed: if @var{b} depends
11698 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
11699 @var{b} usually lacks substitutes as well. The result looks like this:
11702 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
11703 computing 8,983 package derivations for x86_64-linux...
11704 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
11705 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
11706 @value{SUBSTITUTE-URL}
11707 64.7% substitutes available (6,047 out of 9,343)
11709 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
11710 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
11711 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
11712 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
11716 What this example shows is that @code{kcoreaddons} and presumably the 58
11717 packages that depend on it have no substitutes at @code{ci.guix.info};
11718 likewise for @code{qgpgme} and the 46 packages that depend on it.
11720 If you are a Guix developer, or if you are taking care of this build farm,
11721 you'll probably want to have a closer look at these packages: they may simply
11724 @item --display-missing
11725 Display the list of store items for which substitutes are missing.
11728 @node Invoking guix processes
11729 @section Invoking @command{guix processes}
11731 The @command{guix processes} command can be useful to developers and system
11732 administrators, especially on multi-user machines and on build farms: it lists
11733 the current sessions (connections to the daemon), as well as information about
11734 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
11735 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
11736 listed.}. Here's an example of the information it returns:
11739 $ sudo guix processes
11742 ClientCommand: guix environment --ad-hoc python
11746 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
11750 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
11751 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
11752 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
11753 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
11754 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
11755 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
11756 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
11759 In this example we see that @command{guix-daemon} has three clients:
11760 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
11761 integration tool; their process identifier (PID) is given by the
11762 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
11763 @command{guix-daemon} sub-process of this particular session.
11765 The @code{LockHeld} fields show which store items are currently locked by this
11766 session, which corresponds to store items being built or substituted (the
11767 @code{LockHeld} field is not displayed when @command{guix processes} is not
11768 running as root). Last, by looking at the @code{ChildProcess} field, we
11769 understand that these three builds are being offloaded (@pxref{Daemon Offload
11772 The output is in Recutils format so we can use the handy @command{recsel}
11773 command to select sessions of interest (@pxref{Selection Expressions,,,
11774 recutils, GNU recutils manual}). As an example, the command shows the command
11775 line and PID of the client that triggered the build of a Perl package:
11778 $ sudo guix processes | \
11779 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
11781 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
11784 @node System Configuration
11785 @chapter System Configuration
11787 @cindex system configuration
11788 Guix System supports a consistent whole-system configuration
11789 mechanism. By that we mean that all aspects of the global system
11790 configuration---such as the available system services, timezone and
11791 locale settings, user accounts---are declared in a single place. Such
11792 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
11794 One of the advantages of putting all the system configuration under the
11795 control of Guix is that it supports transactional system upgrades, and
11796 makes it possible to roll back to a previous system instantiation,
11797 should something go wrong with the new one (@pxref{Features}). Another
11798 advantage is that it makes it easy to replicate the exact same configuration
11799 across different machines, or at different points in time, without
11800 having to resort to additional administration tools layered on top of
11801 the own tools of the system.
11802 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
11804 This section describes this mechanism. First we focus on the system
11805 administrator's viewpoint---explaining how the system is configured and
11806 instantiated. Then we show how this mechanism can be extended, for
11807 instance to support new system services.
11810 * Using the Configuration System:: Customizing your GNU system.
11811 * operating-system Reference:: Detail of operating-system declarations.
11812 * File Systems:: Configuring file system mounts.
11813 * Mapped Devices:: Block device extra processing.
11814 * User Accounts:: Specifying user accounts.
11815 * Keyboard Layout:: How the system interprets key strokes.
11816 * Locales:: Language and cultural convention settings.
11817 * Services:: Specifying system services.
11818 * Setuid Programs:: Programs running with root privileges.
11819 * X.509 Certificates:: Authenticating HTTPS servers.
11820 * Name Service Switch:: Configuring libc's name service switch.
11821 * Initial RAM Disk:: Linux-Libre bootstrapping.
11822 * Bootloader Configuration:: Configuring the boot loader.
11823 * Invoking guix system:: Instantiating a system configuration.
11824 * Invoking guix deploy:: Deploying a system configuration to a remote host.
11825 * Running Guix in a VM:: How to run Guix System in a virtual machine.
11826 * Defining Services:: Adding new service definitions.
11829 @node Using the Configuration System
11830 @section Using the Configuration System
11832 The operating system is configured by providing an
11833 @code{operating-system} declaration in a file that can then be passed to
11834 the @command{guix system} command (@pxref{Invoking guix system}). A
11835 simple setup, with the default system services, the default Linux-Libre
11836 kernel, initial RAM disk, and boot loader looks like this:
11838 @findex operating-system
11840 @include os-config-bare-bones.texi
11843 This example should be self-describing. Some of the fields defined
11844 above, such as @code{host-name} and @code{bootloader}, are mandatory.
11845 Others, such as @code{packages} and @code{services}, can be omitted, in
11846 which case they get a default value.
11848 Below we discuss the effect of some of the most important fields
11849 (@pxref{operating-system Reference}, for details about all the available
11850 fields), and how to @dfn{instantiate} the operating system using
11851 @command{guix system}.
11853 @unnumberedsubsec Bootloader
11855 @cindex legacy boot, on Intel machines
11856 @cindex BIOS boot, on Intel machines
11859 The @code{bootloader} field describes the method that will be used to boot
11860 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
11861 mode, as in the example above. However, more recent machines rely instead on
11862 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
11863 the @code{bootloader} field should contain something along these lines:
11866 (bootloader-configuration
11867 (bootloader grub-efi-bootloader)
11868 (target "/boot/efi"))
11871 @xref{Bootloader Configuration}, for more information on the available
11872 configuration options.
11874 @unnumberedsubsec Globally-Visible Packages
11876 @vindex %base-packages
11877 The @code{packages} field lists packages that will be globally visible
11878 on the system, for all user accounts---i.e., in every user's @env{PATH}
11879 environment variable---in addition to the per-user profiles
11880 (@pxref{Invoking guix package}). The @code{%base-packages} variable
11881 provides all the tools one would expect for basic user and administrator
11882 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
11883 the GNU Zile lightweight text editor, @command{find}, @command{grep},
11884 etc. The example above adds GNU@tie{}Screen to those,
11885 taken from the @code{(gnu packages screen)}
11886 module (@pxref{Package Modules}). The
11887 @code{(list package output)} syntax can be used to add a specific output
11891 (use-modules (gnu packages))
11892 (use-modules (gnu packages dns))
11896 (packages (cons (list bind "utils")
11900 @findex specification->package
11901 Referring to packages by variable name, like @code{bind} above, has
11902 the advantage of being unambiguous; it also allows typos and such to be
11903 diagnosed right away as ``unbound variables''. The downside is that one
11904 needs to know which module defines which package, and to augment the
11905 @code{use-package-modules} line accordingly. To avoid that, one can use
11906 the @code{specification->package} procedure of the @code{(gnu packages)}
11907 module, which returns the best package for a given name or name and
11911 (use-modules (gnu packages))
11915 (packages (append (map specification->package
11916 '("tcpdump" "htop" "gnupg@@2.0"))
11920 @unnumberedsubsec System Services
11923 @vindex %base-services
11924 The @code{services} field lists @dfn{system services} to be made
11925 available when the system starts (@pxref{Services}).
11926 The @code{operating-system} declaration above specifies that, in
11927 addition to the basic services, we want the OpenSSH secure shell
11928 daemon listening on port 2222 (@pxref{Networking Services,
11929 @code{openssh-service-type}}). Under the hood,
11930 @code{openssh-service-type} arranges so that @command{sshd} is started with the
11931 right command-line options, possibly with supporting configuration files
11932 generated as needed (@pxref{Defining Services}).
11934 @cindex customization, of services
11935 @findex modify-services
11936 Occasionally, instead of using the base services as is, you will want to
11937 customize them. To do this, use @code{modify-services} (@pxref{Service
11938 Reference, @code{modify-services}}) to modify the list.
11940 For example, suppose you want to modify @code{guix-daemon} and Mingetty
11941 (the console log-in) in the @code{%base-services} list (@pxref{Base
11942 Services, @code{%base-services}}). To do that, you can write the
11943 following in your operating system declaration:
11946 (define %my-services
11947 ;; My very own list of services.
11948 (modify-services %base-services
11949 (guix-service-type config =>
11950 (guix-configuration
11952 (use-substitutes? #f)
11953 (extra-options '("--gc-keep-derivations"))))
11954 (mingetty-service-type config =>
11955 (mingetty-configuration
11956 (inherit config)))))
11960 (services %my-services))
11963 This changes the configuration---i.e., the service parameters---of the
11964 @code{guix-service-type} instance, and that of all the
11965 @code{mingetty-service-type} instances in the @code{%base-services} list.
11966 Observe how this is accomplished: first, we arrange for the original
11967 configuration to be bound to the identifier @code{config} in the
11968 @var{body}, and then we write the @var{body} so that it evaluates to the
11969 desired configuration. In particular, notice how we use @code{inherit}
11970 to create a new configuration which has the same values as the old
11971 configuration, but with a few modifications.
11973 @cindex encrypted disk
11974 The configuration for a typical ``desktop'' usage, with an encrypted
11975 root partition, the X11 display
11976 server, GNOME and Xfce (users can choose which of these desktop
11977 environments to use at the log-in screen by pressing @kbd{F1}), network
11978 management, power management, and more, would look like this:
11981 @include os-config-desktop.texi
11984 A graphical system with a choice of lightweight window managers
11985 instead of full-blown desktop environments would look like this:
11988 @include os-config-lightweight-desktop.texi
11991 This example refers to the @file{/boot/efi} file system by its UUID,
11992 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
11993 as returned by the @command{blkid} command.
11995 @xref{Desktop Services}, for the exact list of services provided by
11996 @code{%desktop-services}. @xref{X.509 Certificates}, for background
11997 information about the @code{nss-certs} package that is used here.
11999 Again, @code{%desktop-services} is just a list of service objects. If
12000 you want to remove services from there, you can do so using the
12001 procedures for list filtering (@pxref{SRFI-1 Filtering and
12002 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
12003 following expression returns a list that contains all the services in
12004 @code{%desktop-services} minus the Avahi service:
12007 (remove (lambda (service)
12008 (eq? (service-kind service) avahi-service-type))
12012 @unnumberedsubsec Instantiating the System
12014 Assuming the @code{operating-system} declaration
12015 is stored in the @file{my-system-config.scm}
12016 file, the @command{guix system reconfigure my-system-config.scm} command
12017 instantiates that configuration, and makes it the default GRUB boot
12018 entry (@pxref{Invoking guix system}).
12020 The normal way to change the system configuration is by updating this
12021 file and re-running @command{guix system reconfigure}. One should never
12022 have to touch files in @file{/etc} or to run commands that modify the
12023 system state such as @command{useradd} or @command{grub-install}. In
12024 fact, you must avoid that since that would not only void your warranty
12025 but also prevent you from rolling back to previous versions of your
12026 system, should you ever need to.
12028 @cindex roll-back, of the operating system
12029 Speaking of roll-back, each time you run @command{guix system
12030 reconfigure}, a new @dfn{generation} of the system is created---without
12031 modifying or deleting previous generations. Old system generations get
12032 an entry in the bootloader boot menu, allowing you to boot them in case
12033 something went wrong with the latest generation. Reassuring, no? The
12034 @command{guix system list-generations} command lists the system
12035 generations available on disk. It is also possible to roll back the
12036 system via the commands @command{guix system roll-back} and
12037 @command{guix system switch-generation}.
12039 Although the @command{guix system reconfigure} command will not modify
12040 previous generations, you must take care when the current generation is not
12041 the latest (e.g., after invoking @command{guix system roll-back}), since
12042 the operation might overwrite a later generation (@pxref{Invoking guix
12045 @unnumberedsubsec The Programming Interface
12047 At the Scheme level, the bulk of an @code{operating-system} declaration
12048 is instantiated with the following monadic procedure (@pxref{The Store
12051 @deffn {Monadic Procedure} operating-system-derivation os
12052 Return a derivation that builds @var{os}, an @code{operating-system}
12053 object (@pxref{Derivations}).
12055 The output of the derivation is a single directory that refers to all
12056 the packages, configuration files, and other supporting files needed to
12057 instantiate @var{os}.
12060 This procedure is provided by the @code{(gnu system)} module. Along
12061 with @code{(gnu services)} (@pxref{Services}), this module contains the
12062 guts of Guix System. Make sure to visit it!
12065 @node operating-system Reference
12066 @section @code{operating-system} Reference
12068 This section summarizes all the options available in
12069 @code{operating-system} declarations (@pxref{Using the Configuration
12072 @deftp {Data Type} operating-system
12073 This is the data type representing an operating system configuration.
12074 By that, we mean all the global system configuration, not per-user
12075 configuration (@pxref{Using the Configuration System}).
12078 @item @code{kernel} (default: @code{linux-libre})
12079 The package object of the operating system kernel to
12080 use@footnote{Currently only the Linux-libre kernel is fully supported.
12081 Using GNU@tie{}mach with the GNU@tie{}Hurd is experimental and only
12082 available when building a virtual machine disk image.}.
12085 @item @code{hurd} (default: @code{#f})
12086 The package object of the hurd to be started by the kernel. When this
12087 field is set, produce a GNU/Hurd operating system. In that case,
12088 @code{kernel} must also be set to the @code{gnumach} package---the
12089 microkernel the Hurd runs on.
12092 This feature is experimental and only supported for disk images.
12095 @item @code{kernel-loadable-modules} (default: '())
12096 A list of objects (usually packages) to collect loadable kernel modules
12097 from--e.g. @code{(list ddcci-driver-linux)}.
12099 @item @code{kernel-arguments} (default: @code{%default-kernel-arguments})
12100 List of strings or gexps representing additional arguments to pass on
12101 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
12103 @item @code{bootloader}
12104 The system bootloader configuration object. @xref{Bootloader Configuration}.
12107 This is the label (a string) as it appears in the bootloader's menu entry.
12108 The default label includes the kernel name and version.
12110 @item @code{keyboard-layout} (default: @code{#f})
12111 This field specifies the keyboard layout to use in the console. It can be
12112 either @code{#f}, in which case the default keyboard layout is used (usually
12113 US English), or a @code{<keyboard-layout>} record.
12115 This keyboard layout is in effect as soon as the kernel has booted. For
12116 instance, it is the keyboard layout in effect when you type a passphrase if
12117 your root file system is on a @code{luks-device-mapping} mapped device
12118 (@pxref{Mapped Devices}).
12121 This does @emph{not} specify the keyboard layout used by the bootloader, nor
12122 that used by the graphical display server. @xref{Bootloader Configuration},
12123 for information on how to specify the bootloader's keyboard layout. @xref{X
12124 Window}, for information on how to specify the keyboard layout used by the X
12128 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
12130 @cindex initial RAM disk
12131 The list of Linux kernel modules that need to be available in the
12132 initial RAM disk. @xref{Initial RAM Disk}.
12134 @item @code{initrd} (default: @code{base-initrd})
12135 A procedure that returns an initial RAM disk for the Linux
12136 kernel. This field is provided to support low-level customization and
12137 should rarely be needed for casual use. @xref{Initial RAM Disk}.
12139 @item @code{firmware} (default: @code{%base-firmware})
12141 List of firmware packages loadable by the operating system kernel.
12143 The default includes firmware needed for Atheros- and Broadcom-based
12144 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
12145 respectively). @xref{Hardware Considerations}, for more info on
12146 supported hardware.
12148 @item @code{host-name}
12151 @item @code{hosts-file}
12153 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
12154 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
12155 Reference Manual}). The default is a file with entries for
12156 @code{localhost} and @var{host-name}.
12158 @item @code{mapped-devices} (default: @code{'()})
12159 A list of mapped devices. @xref{Mapped Devices}.
12161 @item @code{file-systems}
12162 A list of file systems. @xref{File Systems}.
12164 @item @code{swap-devices} (default: @code{'()})
12165 @cindex swap devices
12166 A list of strings identifying devices or files to be used for ``swap
12167 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
12168 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
12169 It is possible to specify a swap file in a file system on a mapped
12170 device, provided that the necessary device mapping and file system are
12171 also specified. @xref{Mapped Devices} and @ref{File Systems}.
12173 @item @code{users} (default: @code{%base-user-accounts})
12174 @itemx @code{groups} (default: @code{%base-groups})
12175 List of user accounts and groups. @xref{User Accounts}.
12177 If the @code{users} list lacks a user account with UID@tie{}0, a
12178 ``root'' account with UID@tie{}0 is automatically added.
12180 @item @code{skeletons} (default: @code{(default-skeletons)})
12181 A list of target file name/file-like object tuples (@pxref{G-Expressions,
12182 file-like objects}). These are the skeleton files that will be added to
12183 the home directory of newly-created user accounts.
12185 For instance, a valid value may look like this:
12188 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
12189 (".guile" ,(plain-file "guile"
12190 "(use-modules (ice-9 readline))
12191 (activate-readline)")))
12194 @item @code{issue} (default: @code{%default-issue})
12195 A string denoting the contents of the @file{/etc/issue} file, which is
12196 displayed when users log in on a text console.
12198 @item @code{packages} (default: @code{%base-packages})
12199 A list of packages to be installed in the global profile, which is accessible
12200 at @file{/run/current-system/profile}. Each element is either a package
12201 variable or a package/output tuple. Here's a simple example of both:
12204 (cons* git ; the default "out" output
12205 (list git "send-email") ; another output of git
12206 %base-packages) ; the default set
12209 The default set includes core utilities and it is good practice to
12210 install non-core utilities in user profiles (@pxref{Invoking guix
12213 @item @code{timezone}
12214 A timezone identifying string---e.g., @code{"Europe/Paris"}.
12216 You can run the @command{tzselect} command to find out which timezone
12217 string corresponds to your region. Choosing an invalid timezone name
12218 causes @command{guix system} to fail.
12220 @item @code{locale} (default: @code{"en_US.utf8"})
12221 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
12222 Library Reference Manual}). @xref{Locales}, for more information.
12224 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
12225 The list of locale definitions to be compiled and that may be used at
12226 run time. @xref{Locales}.
12228 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
12229 The list of GNU@tie{}libc packages whose locale data and tools are used
12230 to build the locale definitions. @xref{Locales}, for compatibility
12231 considerations that justify this option.
12233 @item @code{name-service-switch} (default: @code{%default-nss})
12234 Configuration of the libc name service switch (NSS)---a
12235 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
12238 @item @code{services} (default: @code{%base-services})
12239 A list of service objects denoting system services. @xref{Services}.
12241 @cindex essential services
12242 @item @code{essential-services} (default: ...)
12243 The list of ``essential services''---i.e., things like instances of
12244 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
12245 Reference}), which are derived from the operating system definition itself.
12246 As a user you should @emph{never} need to touch this field.
12248 @item @code{pam-services} (default: @code{(base-pam-services)})
12250 @cindex pluggable authentication modules
12251 Linux @dfn{pluggable authentication module} (PAM) services.
12252 @c FIXME: Add xref to PAM services section.
12254 @item @code{setuid-programs} (default: @code{%setuid-programs})
12255 List of string-valued G-expressions denoting setuid programs.
12256 @xref{Setuid Programs}.
12258 @item @code{sudoers-file} (default: @code{%sudoers-specification})
12259 @cindex sudoers file
12260 The contents of the @file{/etc/sudoers} file as a file-like object
12261 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
12263 This file specifies which users can use the @command{sudo} command, what
12264 they are allowed to do, and what privileges they may gain. The default
12265 is that only @code{root} and members of the @code{wheel} group may use
12270 @deffn {Scheme Syntax} this-operating-system
12271 When used in the @emph{lexical scope} of an operating system field definition,
12272 this identifier resolves to the operating system being defined.
12274 The example below shows how to refer to the operating system being defined in
12275 the definition of the @code{label} field:
12278 (use-modules (gnu) (guix))
12282 (label (package-full-name
12283 (operating-system-kernel this-operating-system))))
12286 It is an error to refer to @code{this-operating-system} outside an operating
12293 @section File Systems
12295 The list of file systems to be mounted is specified in the
12296 @code{file-systems} field of the operating system declaration
12297 (@pxref{Using the Configuration System}). Each file system is declared
12298 using the @code{file-system} form, like this:
12302 (mount-point "/home")
12303 (device "/dev/sda3")
12307 As usual, some of the fields are mandatory---those shown in the example
12308 above---while others can be omitted. These are described below.
12310 @deftp {Data Type} file-system
12311 Objects of this type represent file systems to be mounted. They
12312 contain the following members:
12316 This is a string specifying the type of the file system---e.g.,
12319 @item @code{mount-point}
12320 This designates the place where the file system is to be mounted.
12322 @item @code{device}
12323 This names the ``source'' of the file system. It can be one of three
12324 things: a file system label, a file system UUID, or the name of a
12325 @file{/dev} node. Labels and UUIDs offer a way to refer to file
12326 systems without having to hard-code their actual device
12327 name@footnote{Note that, while it is tempting to use
12328 @file{/dev/disk/by-uuid} and similar device names to achieve the same
12329 result, this is not recommended: These special device nodes are created
12330 by the udev daemon and may be unavailable at the time the device is
12333 @findex file-system-label
12334 File system labels are created using the @code{file-system-label}
12335 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
12336 plain strings. Here's an example of a file system referred to by its
12337 label, as shown by the @command{e2label} command:
12341 (mount-point "/home")
12343 (device (file-system-label "my-home")))
12347 UUIDs are converted from their string representation (as shown by the
12348 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
12349 @code{uuid} form expects 16-byte UUIDs as defined in
12350 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
12351 form of UUID used by the ext2 family of file systems and others, but it
12352 is different from ``UUIDs'' found in FAT file systems, for instance.},
12357 (mount-point "/home")
12359 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
12362 When the source of a file system is a mapped device (@pxref{Mapped
12363 Devices}), its @code{device} field @emph{must} refer to the mapped
12364 device name---e.g., @file{"/dev/mapper/root-partition"}.
12365 This is required so that
12366 the system knows that mounting the file system depends on having the
12367 corresponding device mapping established.
12369 @item @code{flags} (default: @code{'()})
12370 This is a list of symbols denoting mount flags. Recognized flags
12371 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
12372 access to special files), @code{no-suid} (ignore setuid and setgid
12373 bits), @code{no-atime} (do not update file access times),
12374 @code{strict-atime} (update file access time), @code{lazy-time} (only
12375 update time on the in-memory version of the file inode), and
12376 @code{no-exec} (disallow program execution).
12377 @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
12378 Manual}, for more information on these flags.
12380 @item @code{options} (default: @code{#f})
12381 This is either @code{#f}, or a string denoting mount options passed to
12382 the file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C
12383 Library Reference Manual}, for details and run @command{man 8 mount} for
12384 options for various file systems. Note that the
12385 @code{file-system-options->alist} and @code{alist->file-system-options}
12386 procedures from @code{(gnu system file-systems)} can be used to convert
12387 file system options given as an association list to the string
12388 representation, and vice-versa.
12390 @item @code{mount?} (default: @code{#t})
12391 This value indicates whether to automatically mount the file system when
12392 the system is brought up. When set to @code{#f}, the file system gets
12393 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
12394 is not automatically mounted.
12396 @item @code{needed-for-boot?} (default: @code{#f})
12397 This Boolean value indicates whether the file system is needed when
12398 booting. If that is true, then the file system is mounted when the
12399 initial RAM disk (initrd) is loaded. This is always the case, for
12400 instance, for the root file system.
12402 @item @code{check?} (default: @code{#t})
12403 This Boolean indicates whether the file system needs to be checked for
12404 errors before being mounted.
12406 @item @code{create-mount-point?} (default: @code{#f})
12407 When true, the mount point is created if it does not exist yet.
12409 @item @code{mount-may-fail?} (default: @code{#f})
12410 When true, this indicates that mounting this file system can fail but
12411 that should not be considered an error. This is useful in unusual
12412 cases; an example of this is @code{efivarfs}, a file system that can
12413 only be mounted on EFI/UEFI systems.
12415 @item @code{dependencies} (default: @code{'()})
12416 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
12417 representing file systems that must be mounted or mapped devices that
12418 must be opened before (and unmounted or closed after) this one.
12420 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
12421 a dependency of @file{/sys/fs/cgroup/cpu} and
12422 @file{/sys/fs/cgroup/memory}.
12424 Another example is a file system that depends on a mapped device, for
12425 example for an encrypted partition (@pxref{Mapped Devices}).
12429 @deffn {Scheme Procedure} file-system-label @var{str}
12430 This procedure returns an opaque file system label from @var{str}, a
12434 (file-system-label "home")
12435 @result{} #<file-system-label "home">
12438 File system labels are used to refer to file systems by label rather
12439 than by device name. See above for examples.
12442 The @code{(gnu system file-systems)} exports the following useful
12445 @defvr {Scheme Variable} %base-file-systems
12446 These are essential file systems that are required on normal systems,
12447 such as @code{%pseudo-terminal-file-system} and @code{%immutable-store} (see
12448 below). Operating system declarations should always contain at least
12452 @defvr {Scheme Variable} %pseudo-terminal-file-system
12453 This is the file system to be mounted as @file{/dev/pts}. It supports
12454 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
12455 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
12456 Manual}). Pseudo-terminals are used by terminal emulators such as
12460 @defvr {Scheme Variable} %shared-memory-file-system
12461 This file system is mounted as @file{/dev/shm} and is used to support
12462 memory sharing across processes (@pxref{Memory-mapped I/O,
12463 @code{shm_open},, libc, The GNU C Library Reference Manual}).
12466 @defvr {Scheme Variable} %immutable-store
12467 This file system performs a read-only ``bind mount'' of
12468 @file{/gnu/store}, making it read-only for all the users including
12469 @code{root}. This prevents against accidental modification by software
12470 running as @code{root} or by system administrators.
12472 The daemon itself is still able to write to the store: it remounts it
12473 read-write in its own ``name space.''
12476 @defvr {Scheme Variable} %binary-format-file-system
12477 The @code{binfmt_misc} file system, which allows handling of arbitrary
12478 executable file types to be delegated to user space. This requires the
12479 @code{binfmt.ko} kernel module to be loaded.
12482 @defvr {Scheme Variable} %fuse-control-file-system
12483 The @code{fusectl} file system, which allows unprivileged users to mount
12484 and unmount user-space FUSE file systems. This requires the
12485 @code{fuse.ko} kernel module to be loaded.
12488 The @code{(gnu system uuid)} module provides tools to deal with file
12489 system ``unique identifiers'' (UUIDs).
12491 @deffn {Scheme Procedure} uuid @var{str} [@var{type}]
12492 Return an opaque UUID (unique identifier) object of the given @var{type}
12493 (a symbol) by parsing @var{str} (a string):
12496 (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")
12497 @result{} #<<uuid> type: dce bv: @dots{}>
12499 (uuid "1234-ABCD" 'fat)
12500 @result{} #<<uuid> type: fat bv: @dots{}>
12503 @var{type} may be one of @code{dce}, @code{iso9660}, @code{fat},
12504 @code{ntfs}, or one of the commonly found synonyms for these.
12506 UUIDs are another way to unambiguously refer to file systems in
12507 operating system configuration. See the examples above.
12511 @node Btrfs file system
12512 @subsection Btrfs file system
12514 The Btrfs has special features, such as subvolumes, that merit being
12515 explained in more details. The following section attempts to cover
12516 basic as well as complex uses of a Btrfs file system with the Guix
12519 In its simplest usage, a Btrfs file system can be described, for
12524 (mount-point "/home")
12526 (device (file-system-label "my-home")))
12529 The example below is more complex, as it makes use of a Btrfs
12530 subvolume, named @code{rootfs}. The parent Btrfs file system is labeled
12531 @code{my-btrfs-pool}, and is located on an encrypted device (hence the
12532 dependency on @code{mapped-devices}):
12536 (device (file-system-label "my-btrfs-pool"))
12539 (options "subvol=rootfs")
12540 (dependencies mapped-devices))
12543 Some bootloaders, for example GRUB, only mount a Btrfs partition at its
12544 top level during the early boot, and rely on their configuration to
12545 refer to the correct subvolume path within that top level. The
12546 bootloaders operating in this way typically produce their configuration
12547 on a running system where the Btrfs partitions are already mounted and
12548 where the subvolume information is readily available. As an example,
12549 @command{grub-mkconfig}, the configuration generator command shipped
12550 with GRUB, reads @file{/proc/self/mountinfo} to determine the top-level
12551 path of a subvolume.
12553 The Guix System produces a bootloader configuration using the operating
12554 system configuration as its sole input; it is therefore necessary to
12555 extract the subvolume name on which @file{/gnu/store} lives (if any)
12556 from that operating system configuration. To better illustrate,
12557 consider a subvolume named 'rootfs' which contains the root file system
12558 data. In such situation, the GRUB bootloader would only see the top
12559 level of the root Btrfs partition, e.g.:
12563 ├── rootfs (subvolume directory)
12564 ├── gnu (normal directory)
12565 ├── store (normal directory)
12569 Thus, the subvolume name must be prepended to the @file{/gnu/store} path
12570 of the kernel, initrd binaries and any other files referred to in the
12571 GRUB configuration that must be found during the early boot.
12573 The next example shows a nested hierarchy of subvolumes and
12578 ├── rootfs (subvolume)
12579 ├── gnu (normal directory)
12580 ├── store (subvolume)
12584 This scenario would work without mounting the 'store' subvolume.
12585 Mounting 'rootfs' is sufficient, since the subvolume name matches its
12586 intended mount point in the file system hierarchy. Alternatively, the
12587 'store' subvolume could be referred to by setting the @code{subvol}
12588 option to either @code{/rootfs/gnu/store} or @code{rootfs/gnu/store}.
12590 Finally, a more contrived example of nested subvolumes:
12594 ├── root-snapshots (subvolume)
12595 ├── root-current (subvolume)
12596 ├── guix-store (subvolume)
12600 Here, the 'guix-store' subvolume doesn't match its intended mount point,
12601 so it is necessary to mount it. The subvolume must be fully specified,
12602 by passing its file name to the @code{subvol} option. To illustrate,
12603 the 'guix-store' subvolume could be mounted on @file{/gnu/store} by using
12604 a file system declaration such as:
12608 (device (file-system-label "btrfs-pool-1"))
12609 (mount-point "/gnu/store")
12611 (options "subvol=root-snapshots/root-current/guix-store,\
12612 compress-force=zstd,space_cache=v2"))
12615 @node Mapped Devices
12616 @section Mapped Devices
12618 @cindex device mapping
12619 @cindex mapped devices
12620 The Linux kernel has a notion of @dfn{device mapping}: a block device,
12621 such as a hard disk partition, can be @dfn{mapped} into another device,
12622 usually in @code{/dev/mapper/},
12623 with additional processing over the data that flows through
12624 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
12625 concept of a ``mapped device'' and that of a file system: both boil down
12626 to @emph{translating} input/output operations made on a file to
12627 operations on its backing store. Thus, the Hurd implements mapped
12628 devices, like file systems, using the generic @dfn{translator} mechanism
12629 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
12630 typical example is encryption device mapping: all writes to the mapped
12631 device are encrypted, and all reads are deciphered, transparently.
12632 Guix extends this notion by considering any device or set of devices that
12633 are @dfn{transformed} in some way to create a new device; for instance,
12634 RAID devices are obtained by @dfn{assembling} several other devices, such
12635 as hard disks or partitions, into a new one that behaves as one partition.
12636 Other examples, not yet implemented, are LVM logical volumes.
12638 Mapped devices are declared using the @code{mapped-device} form,
12639 defined as follows; for examples, see below.
12641 @deftp {Data Type} mapped-device
12642 Objects of this type represent device mappings that will be made when
12643 the system boots up.
12647 This is either a string specifying the name of the block device to be mapped,
12648 such as @code{"/dev/sda3"}, or a list of such strings when several devices
12649 need to be assembled for creating a new one.
12652 This string specifies the name of the resulting mapped device. For
12653 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
12654 specifying @code{"my-partition"} leads to the creation of
12655 the @code{"/dev/mapper/my-partition"} device.
12656 For RAID devices of type @code{raid-device-mapping}, the full device name
12657 such as @code{"/dev/md0"} needs to be given.
12660 This must be a @code{mapped-device-kind} object, which specifies how
12661 @var{source} is mapped to @var{target}.
12665 @defvr {Scheme Variable} luks-device-mapping
12666 This defines LUKS block device encryption using the @command{cryptsetup}
12667 command from the package with the same name. It relies on the
12668 @code{dm-crypt} Linux kernel module.
12671 @defvr {Scheme Variable} raid-device-mapping
12672 This defines a RAID device, which is assembled using the @code{mdadm}
12673 command from the package with the same name. It requires a Linux kernel
12674 module for the appropriate RAID level to be loaded, such as @code{raid456}
12675 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
12678 @cindex disk encryption
12680 The following example specifies a mapping from @file{/dev/sda3} to
12681 @file{/dev/mapper/home} using LUKS---the
12682 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
12683 standard mechanism for disk encryption.
12684 The @file{/dev/mapper/home}
12685 device can then be used as the @code{device} of a @code{file-system}
12686 declaration (@pxref{File Systems}).
12690 (source "/dev/sda3")
12692 (type luks-device-mapping))
12695 Alternatively, to become independent of device numbering, one may obtain
12696 the LUKS UUID (@dfn{unique identifier}) of the source device by a
12700 cryptsetup luksUUID /dev/sda3
12703 and use it as follows:
12707 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
12709 (type luks-device-mapping))
12712 @cindex swap encryption
12713 It is also desirable to encrypt swap space, since swap space may contain
12714 sensitive data. One way to accomplish that is to use a swap file in a
12715 file system on a device mapped via LUKS encryption. In this way, the
12716 swap file is encrypted because the entire device is encrypted.
12717 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
12719 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
12720 may be declared as follows:
12724 (source (list "/dev/sda1" "/dev/sdb1"))
12725 (target "/dev/md0")
12726 (type raid-device-mapping))
12729 The @file{/dev/md0} device can then be used as the @code{device} of a
12730 @code{file-system} declaration (@pxref{File Systems}).
12731 Note that the RAID level need not be given; it is chosen during the
12732 initial creation and formatting of the RAID device and is determined
12733 automatically later.
12736 @node User Accounts
12737 @section User Accounts
12741 @cindex user accounts
12742 User accounts and groups are entirely managed through the
12743 @code{operating-system} declaration. They are specified with the
12744 @code{user-account} and @code{user-group} forms:
12750 (supplementary-groups '("wheel" ;allow use of sudo, etc.
12751 "audio" ;sound card
12752 "video" ;video devices such as webcams
12753 "cdrom")) ;the good ol' CD-ROM
12754 (comment "Bob's sister")
12755 (home-directory "/home/alice"))
12758 When booting or upon completion of @command{guix system reconfigure},
12759 the system ensures that only the user accounts and groups specified in
12760 the @code{operating-system} declaration exist, and with the specified
12761 properties. Thus, account or group creations or modifications made by
12762 directly invoking commands such as @command{useradd} are lost upon
12763 reconfiguration or reboot. This ensures that the system remains exactly
12766 @deftp {Data Type} user-account
12767 Objects of this type represent user accounts. The following members may
12772 The name of the user account.
12776 This is the name (a string) or identifier (a number) of the user group
12777 this account belongs to.
12779 @item @code{supplementary-groups} (default: @code{'()})
12780 Optionally, this can be defined as a list of group names that this
12781 account belongs to.
12783 @item @code{uid} (default: @code{#f})
12784 This is the user ID for this account (a number), or @code{#f}. In the
12785 latter case, a number is automatically chosen by the system when the
12786 account is created.
12788 @item @code{comment} (default: @code{""})
12789 A comment about the account, such as the account owner's full name.
12791 @item @code{home-directory}
12792 This is the name of the home directory for the account.
12794 @item @code{create-home-directory?} (default: @code{#t})
12795 Indicates whether the home directory of this account should be created
12796 if it does not exist yet.
12798 @item @code{shell} (default: Bash)
12799 This is a G-expression denoting the file name of a program to be used as
12800 the shell (@pxref{G-Expressions}).
12802 @item @code{system?} (default: @code{#f})
12803 This Boolean value indicates whether the account is a ``system''
12804 account. System accounts are sometimes treated specially; for instance,
12805 graphical login managers do not list them.
12807 @anchor{user-account-password}
12808 @cindex password, for user accounts
12809 @item @code{password} (default: @code{#f})
12810 You would normally leave this field to @code{#f}, initialize user
12811 passwords as @code{root} with the @command{passwd} command, and then let
12812 users change it with @command{passwd}. Passwords set with
12813 @command{passwd} are of course preserved across reboot and
12816 If you @emph{do} want to set an initial password for an account, then
12817 this field must contain the encrypted password, as a string. You can use the
12818 @code{crypt} procedure for this purpose:
12825 ;; Specify a SHA-512-hashed initial password.
12826 (password (crypt "InitialPassword!" "$6$abc")))
12830 The hash of this initial password will be available in a file in
12831 @file{/gnu/store}, readable by all the users, so this method must be used with
12835 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
12836 more information on password encryption, and @ref{Encryption,,, guile, GNU
12837 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
12843 User group declarations are even simpler:
12846 (user-group (name "students"))
12849 @deftp {Data Type} user-group
12850 This type is for, well, user groups. There are just a few fields:
12854 The name of the group.
12856 @item @code{id} (default: @code{#f})
12857 The group identifier (a number). If @code{#f}, a new number is
12858 automatically allocated when the group is created.
12860 @item @code{system?} (default: @code{#f})
12861 This Boolean value indicates whether the group is a ``system'' group.
12862 System groups have low numerical IDs.
12864 @item @code{password} (default: @code{#f})
12865 What, user groups can have a password? Well, apparently yes. Unless
12866 @code{#f}, this field specifies the password of the group.
12871 For convenience, a variable lists all the basic user groups one may
12874 @defvr {Scheme Variable} %base-groups
12875 This is the list of basic user groups that users and/or packages expect
12876 to be present on the system. This includes groups such as ``root'',
12877 ``wheel'', and ``users'', as well as groups used to control access to
12878 specific devices such as ``audio'', ``disk'', and ``cdrom''.
12881 @defvr {Scheme Variable} %base-user-accounts
12882 This is the list of basic system accounts that programs may expect to
12883 find on a GNU/Linux system, such as the ``nobody'' account.
12885 Note that the ``root'' account is not included here. It is a
12886 special-case and is automatically added whether or not it is specified.
12889 @node Keyboard Layout
12890 @section Keyboard Layout
12892 @cindex keyboard layout
12894 To specify what each key of your keyboard does, you need to tell the operating
12895 system what @dfn{keyboard layout} you want to use. The default, when nothing
12896 is specified, is the US English QWERTY layout for 105-key PC keyboards.
12897 However, German speakers will usually prefer the German QWERTZ layout, French
12898 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
12899 or bépo, and they might even want to further customize the effect of some of
12900 the keys. This section explains how to get that done.
12902 @cindex keyboard layout, definition
12903 There are three components that will want to know about your keyboard layout:
12907 The @emph{bootloader} may want to know what keyboard layout you want to use
12908 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
12909 you want, for instance, to make sure that you can type the passphrase of your
12910 encrypted root partition using the right layout.
12913 The @emph{operating system kernel}, Linux, will need that so that the console
12914 is properly configured (@pxref{operating-system Reference,
12915 @code{keyboard-layout}}).
12918 The @emph{graphical display server}, usually Xorg, also has its own idea of
12919 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
12922 Guix allows you to configure all three separately but, fortunately, it allows
12923 you to share the same keyboard layout for all three components.
12925 @cindex XKB, keyboard layouts
12926 Keyboard layouts are represented by records created by the
12927 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
12928 the X Keyboard extension (XKB), each layout has four attributes: a name (often
12929 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
12930 optional variant name, an optional keyboard model name, and a possibly empty
12931 list of additional options. In most cases the layout name is all you care
12932 about. Here are a few example:
12935 ;; The German QWERTZ layout. Here we assume a standard
12936 ;; "pc105" keyboard model.
12937 (keyboard-layout "de")
12939 ;; The bépo variant of the French layout.
12940 (keyboard-layout "fr" "bepo")
12942 ;; The Catalan layout.
12943 (keyboard-layout "es" "cat")
12945 ;; Arabic layout with "Alt-Shift" to switch to US layout.
12946 (keyboard-layout "ar,us" #:options '("grp:alt_shift_toggle"))
12948 ;; The Latin American Spanish layout. In addition, the
12949 ;; "Caps Lock" key is used as an additional "Ctrl" key,
12950 ;; and the "Menu" key is used as a "Compose" key to enter
12951 ;; accented letters.
12952 (keyboard-layout "latam"
12953 #:options '("ctrl:nocaps" "compose:menu"))
12955 ;; The Russian layout for a ThinkPad keyboard.
12956 (keyboard-layout "ru" #:model "thinkpad")
12958 ;; The "US international" layout, which is the US layout plus
12959 ;; dead keys to enter accented characters. This is for an
12960 ;; Apple MacBook keyboard.
12961 (keyboard-layout "us" "intl" #:model "macbook78")
12964 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
12965 for a complete list of supported layouts, variants, and models.
12967 @cindex keyboard layout, configuration
12968 Let's say you want your system to use the Turkish keyboard layout throughout
12969 your system---bootloader, console, and Xorg. Here's what your system
12970 configuration would look like:
12972 @findex set-xorg-configuration
12974 ;; Using the Turkish layout for the bootloader, the console,
12979 (keyboard-layout (keyboard-layout "tr")) ;for the console
12980 (bootloader (bootloader-configuration
12981 (bootloader grub-efi-bootloader)
12982 (target "/boot/efi")
12983 (keyboard-layout keyboard-layout))) ;for GRUB
12984 (services (cons (set-xorg-configuration
12985 (xorg-configuration ;for Xorg
12986 (keyboard-layout keyboard-layout)))
12987 %desktop-services)))
12990 In the example above, for GRUB and for Xorg, we just refer to the
12991 @code{keyboard-layout} field defined above, but we could just as well refer to
12992 a different layout. The @code{set-xorg-configuration} procedure communicates
12993 the desired Xorg configuration to the graphical log-in manager, by default
12996 We've discussed how to specify the @emph{default} keyboard layout of your
12997 system when it starts, but you can also adjust it at run time:
13001 If you're using GNOME, its settings panel has a ``Region & Language'' entry
13002 where you can select one or more keyboard layouts.
13005 Under Xorg, the @command{setxkbmap} command (from the same-named package)
13006 allows you to change the current layout. For example, this is how you would
13007 change the layout to US Dvorak:
13010 setxkbmap us dvorak
13014 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
13015 console. However, note that @code{loadkeys} does @emph{not} use the XKB
13016 keyboard layout categorization described above. The command below loads the
13017 French bépo layout:
13028 A @dfn{locale} defines cultural conventions for a particular language
13029 and region of the world (@pxref{Locales,,, libc, The GNU C Library
13030 Reference Manual}). Each locale has a name that typically has the form
13031 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
13032 @code{fr_LU.utf8} designates the locale for the French language, with
13033 cultural conventions from Luxembourg, and using the UTF-8 encoding.
13035 @cindex locale definition
13036 Usually, you will want to specify the default locale for the machine
13037 using the @code{locale} field of the @code{operating-system} declaration
13038 (@pxref{operating-system Reference, @code{locale}}).
13040 The selected locale is automatically added to the @dfn{locale
13041 definitions} known to the system if needed, with its codeset inferred
13042 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
13043 @code{UTF-8} codeset. Additional locale definitions can be specified in
13044 the @code{locale-definitions} slot of @code{operating-system}---this is
13045 useful, for instance, if the codeset could not be inferred from the
13046 locale name. The default set of locale definitions includes some widely
13047 used locales, but not all the available locales, in order to save space.
13049 For instance, to add the North Frisian locale for Germany, the value of
13053 (cons (locale-definition
13054 (name "fy_DE.utf8") (source "fy_DE"))
13055 %default-locale-definitions)
13058 Likewise, to save space, one might want @code{locale-definitions} to
13059 list only the locales that are actually used, as in:
13062 (list (locale-definition
13063 (name "ja_JP.eucjp") (source "ja_JP")
13064 (charset "EUC-JP")))
13068 The compiled locale definitions are available at
13069 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
13070 version, which is the default location where the GNU@tie{}libc provided
13071 by Guix looks for locale data. This can be overridden using the
13072 @env{LOCPATH} environment variable (@pxref{locales-and-locpath,
13073 @env{LOCPATH} and locale packages}).
13075 The @code{locale-definition} form is provided by the @code{(gnu system
13076 locale)} module. Details are given below.
13078 @deftp {Data Type} locale-definition
13079 This is the data type of a locale definition.
13084 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
13085 Reference Manual}, for more information on locale names.
13087 @item @code{source}
13088 The name of the source for that locale. This is typically the
13089 @code{@var{language}_@var{territory}} part of the locale name.
13091 @item @code{charset} (default: @code{"UTF-8"})
13092 The ``character set'' or ``code set'' for that locale,
13093 @uref{https://www.iana.org/assignments/character-sets, as defined by
13099 @defvr {Scheme Variable} %default-locale-definitions
13100 A list of commonly used UTF-8 locales, used as the default
13101 value of the @code{locale-definitions} field of @code{operating-system}
13104 @cindex locale name
13105 @cindex normalized codeset in locale names
13106 These locale definitions use the @dfn{normalized codeset} for the part
13107 that follows the dot in the name (@pxref{Using gettextized software,
13108 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
13109 instance it has @code{uk_UA.utf8} but @emph{not}, say,
13110 @code{uk_UA.UTF-8}.
13113 @subsection Locale Data Compatibility Considerations
13115 @cindex incompatibility, of locale data
13116 @code{operating-system} declarations provide a @code{locale-libcs} field
13117 to specify the GNU@tie{}libc packages that are used to compile locale
13118 declarations (@pxref{operating-system Reference}). ``Why would I
13119 care?'', you may ask. Well, it turns out that the binary format of
13120 locale data is occasionally incompatible from one libc version to
13123 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
13124 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
13125 For instance, a program linked against libc version 2.21 is unable to
13126 read locale data produced with libc 2.22; worse, that program
13127 @emph{aborts} instead of simply ignoring the incompatible locale
13128 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
13129 the incompatible locale data, which is already an improvement.}.
13130 Similarly, a program linked against libc 2.22 can read most, but not
13131 all, of the locale data from libc 2.21 (specifically, @env{LC_COLLATE}
13132 data is incompatible); thus calls to @code{setlocale} may fail, but
13133 programs will not abort.
13135 The ``problem'' with Guix is that users have a lot of freedom: They can
13136 choose whether and when to upgrade software in their profiles, and might
13137 be using a libc version different from the one the system administrator
13138 used to build the system-wide locale data.
13140 Fortunately, unprivileged users can also install their own locale data
13141 and define @env{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
13142 @env{GUIX_LOCPATH} and locale packages}).
13144 Still, it is best if the system-wide locale data at
13145 @file{/run/current-system/locale} is built for all the libc versions
13146 actually in use on the system, so that all the programs can access
13147 it---this is especially crucial on a multi-user system. To do that, the
13148 administrator can specify several libc packages in the
13149 @code{locale-libcs} field of @code{operating-system}:
13152 (use-package-modules base)
13156 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
13159 This example would lead to a system containing locale definitions for
13160 both libc 2.21 and the current version of libc in
13161 @file{/run/current-system/locale}.
13167 @cindex system services
13168 An important part of preparing an @code{operating-system} declaration is
13169 listing @dfn{system services} and their configuration (@pxref{Using the
13170 Configuration System}). System services are typically daemons launched
13171 when the system boots, or other actions needed at that time---e.g.,
13172 configuring network access.
13174 Guix has a broad definition of ``service'' (@pxref{Service
13175 Composition}), but many services are managed by the GNU@tie{}Shepherd
13176 (@pxref{Shepherd Services}). On a running system, the @command{herd}
13177 command allows you to list the available services, show their status,
13178 start and stop them, or do other specific operations (@pxref{Jump
13179 Start,,, shepherd, The GNU Shepherd Manual}). For example:
13185 The above command, run as @code{root}, lists the currently defined
13186 services. The @command{herd doc} command shows a synopsis of the given
13187 service and its associated actions:
13191 Run libc's name service cache daemon (nscd).
13193 # herd doc nscd action invalidate
13194 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
13197 The @command{start}, @command{stop}, and @command{restart} sub-commands
13198 have the effect you would expect. For instance, the commands below stop
13199 the nscd service and restart the Xorg display server:
13203 Service nscd has been stopped.
13204 # herd restart xorg-server
13205 Service xorg-server has been stopped.
13206 Service xorg-server has been started.
13209 The following sections document the available services, starting with
13210 the core services, that may be used in an @code{operating-system}
13214 * Base Services:: Essential system services.
13215 * Scheduled Job Execution:: The mcron service.
13216 * Log Rotation:: The rottlog service.
13217 * Networking Services:: Network setup, SSH daemon, etc.
13218 * Unattended Upgrades:: Automated system upgrades.
13219 * X Window:: Graphical display.
13220 * Printing Services:: Local and remote printer support.
13221 * Desktop Services:: D-Bus and desktop services.
13222 * Sound Services:: ALSA and Pulseaudio services.
13223 * Database Services:: SQL databases, key-value stores, etc.
13224 * Mail Services:: IMAP, POP3, SMTP, and all that.
13225 * Messaging Services:: Messaging services.
13226 * Telephony Services:: Telephony services.
13227 * Monitoring Services:: Monitoring services.
13228 * Kerberos Services:: Kerberos services.
13229 * LDAP Services:: LDAP services.
13230 * Web Services:: Web servers.
13231 * Certificate Services:: TLS certificates via Let's Encrypt.
13232 * DNS Services:: DNS daemons.
13233 * VPN Services:: VPN daemons.
13234 * Network File System:: NFS related services.
13235 * Continuous Integration:: The Cuirass service.
13236 * Power Management Services:: Extending battery life.
13237 * Audio Services:: The MPD.
13238 * Virtualization Services:: Virtualization services.
13239 * Version Control Services:: Providing remote access to Git repositories.
13240 * Game Services:: Game servers.
13241 * PAM Mount Service:: Service to mount volumes when logging in.
13242 * Guix Services:: Services relating specifically to Guix.
13243 * Linux Services:: Services tied to the Linux kernel.
13244 * Hurd Services:: Services specific for a Hurd System.
13245 * Miscellaneous Services:: Other services.
13248 @node Base Services
13249 @subsection Base Services
13251 The @code{(gnu services base)} module provides definitions for the basic
13252 services that one expects from the system. The services exported by
13253 this module are listed below.
13255 @defvr {Scheme Variable} %base-services
13256 This variable contains a list of basic services (@pxref{Service Types
13257 and Services}, for more information on service objects) one would
13258 expect from the system: a login service (mingetty) on each tty, syslogd,
13259 the libc name service cache daemon (nscd), the udev device manager, and
13262 This is the default value of the @code{services} field of
13263 @code{operating-system} declarations. Usually, when customizing a
13264 system, you will want to append services to @code{%base-services}, like
13268 (append (list (service avahi-service-type)
13269 (service openssh-service-type))
13274 @defvr {Scheme Variable} special-files-service-type
13275 This is the service that sets up ``special files'' such as
13276 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
13278 The value associated with @code{special-files-service-type} services
13279 must be a list of tuples where the first element is the ``special file''
13280 and the second element is its target. By default it is:
13282 @cindex @file{/bin/sh}
13283 @cindex @file{sh}, in @file{/bin}
13285 `(("/bin/sh" ,(file-append bash "/bin/sh")))
13288 @cindex @file{/usr/bin/env}
13289 @cindex @file{env}, in @file{/usr/bin}
13290 If you want to add, say, @code{/usr/bin/env} to your system, you can
13294 `(("/bin/sh" ,(file-append bash "/bin/sh"))
13295 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
13298 Since this is part of @code{%base-services}, you can use
13299 @code{modify-services} to customize the set of special files
13300 (@pxref{Service Reference, @code{modify-services}}). But the simple way
13301 to add a special file is @i{via} the @code{extra-special-file} procedure
13305 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
13306 Use @var{target} as the ``special file'' @var{file}.
13308 For example, adding the following lines to the @code{services} field of
13309 your operating system declaration leads to a @file{/usr/bin/env}
13313 (extra-special-file "/usr/bin/env"
13314 (file-append coreutils "/bin/env"))
13318 @deffn {Scheme Procedure} host-name-service @var{name}
13319 Return a service that sets the host name to @var{name}.
13322 @defvr {Scheme Variable} console-font-service-type
13323 Install the given fonts on the specified ttys (fonts are per
13324 virtual console on the kernel Linux). The value of this service is a list of
13325 tty/font pairs. The font can be the name of a font provided by the @code{kbd}
13326 package or any valid argument to @command{setfont}, as in this example:
13329 `(("tty1" . "LatGrkCyr-8x16")
13330 ("tty2" . ,(file-append
13332 "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
13333 ("tty3" . ,(file-append
13335 "/share/consolefonts/ter-132n"))) ; for HDPI
13339 @deffn {Scheme Procedure} login-service @var{config}
13340 Return a service to run login according to @var{config}, a
13341 @code{<login-configuration>} object, which specifies the message of the day,
13342 among other things.
13345 @deftp {Data Type} login-configuration
13346 This is the data type representing the configuration of login.
13351 @cindex message of the day
13352 A file-like object containing the ``message of the day''.
13354 @item @code{allow-empty-passwords?} (default: @code{#t})
13355 Allow empty passwords by default so that first-time users can log in when
13356 the 'root' account has just been created.
13361 @deffn {Scheme Procedure} mingetty-service @var{config}
13362 Return a service to run mingetty according to @var{config}, a
13363 @code{<mingetty-configuration>} object, which specifies the tty to run, among
13367 @deftp {Data Type} mingetty-configuration
13368 This is the data type representing the configuration of Mingetty, which
13369 provides the default implementation of virtual console log-in.
13374 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
13376 @item @code{auto-login} (default: @code{#f})
13377 When true, this field must be a string denoting the user name under
13378 which the system automatically logs in. When it is @code{#f}, a
13379 user name and password must be entered to log in.
13381 @item @code{login-program} (default: @code{#f})
13382 This must be either @code{#f}, in which case the default log-in program
13383 is used (@command{login} from the Shadow tool suite), or a gexp denoting
13384 the name of the log-in program.
13386 @item @code{login-pause?} (default: @code{#f})
13387 When set to @code{#t} in conjunction with @var{auto-login}, the user
13388 will have to press a key before the log-in shell is launched.
13390 @item @code{mingetty} (default: @var{mingetty})
13391 The Mingetty package to use.
13396 @deffn {Scheme Procedure} agetty-service @var{config}
13397 Return a service to run agetty according to @var{config}, an
13398 @code{<agetty-configuration>} object, which specifies the tty to run,
13399 among other things.
13402 @deftp {Data Type} agetty-configuration
13403 This is the data type representing the configuration of agetty, which
13404 implements virtual and serial console log-in. See the @code{agetty(8)}
13405 man page for more information.
13410 The name of the console this agetty runs on, as a string---e.g.,
13411 @code{"ttyS0"}. This argument is optional, it will default to
13412 a reasonable default serial port used by the kernel Linux.
13414 For this, if there is a value for an option @code{agetty.tty} in the kernel
13415 command line, agetty will extract the device name of the serial port
13416 from it and use that.
13418 If not and if there is a value for an option @code{console} with a tty in
13419 the Linux command line, agetty will extract the device name of the
13420 serial port from it and use that.
13422 In both cases, agetty will leave the other serial device settings
13423 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
13426 @item @code{baud-rate} (default: @code{#f})
13427 A string containing a comma-separated list of one or more baud rates, in
13430 @item @code{term} (default: @code{#f})
13431 A string containing the value used for the @env{TERM} environment
13434 @item @code{eight-bits?} (default: @code{#f})
13435 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
13438 @item @code{auto-login} (default: @code{#f})
13439 When passed a login name, as a string, the specified user will be logged
13440 in automatically without prompting for their login name or password.
13442 @item @code{no-reset?} (default: @code{#f})
13443 When @code{#t}, don't reset terminal cflags (control modes).
13445 @item @code{host} (default: @code{#f})
13446 This accepts a string containing the ``login_host'', which will be written
13447 into the @file{/var/run/utmpx} file.
13449 @item @code{remote?} (default: @code{#f})
13450 When set to @code{#t} in conjunction with @var{host}, this will add an
13451 @code{-r} fakehost option to the command line of the login program
13452 specified in @var{login-program}.
13454 @item @code{flow-control?} (default: @code{#f})
13455 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
13457 @item @code{no-issue?} (default: @code{#f})
13458 When set to @code{#t}, the contents of the @file{/etc/issue} file will
13459 not be displayed before presenting the login prompt.
13461 @item @code{init-string} (default: @code{#f})
13462 This accepts a string that will be sent to the tty or modem before
13463 sending anything else. It can be used to initialize a modem.
13465 @item @code{no-clear?} (default: @code{#f})
13466 When set to @code{#t}, agetty will not clear the screen before showing
13469 @item @code{login-program} (default: (file-append shadow "/bin/login"))
13470 This must be either a gexp denoting the name of a log-in program, or
13471 unset, in which case the default value is the @command{login} from the
13474 @item @code{local-line} (default: @code{#f})
13475 Control the CLOCAL line flag. This accepts one of three symbols as
13476 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
13477 the default value chosen by agetty is @code{'auto}.
13479 @item @code{extract-baud?} (default: @code{#f})
13480 When set to @code{#t}, instruct agetty to try to extract the baud rate
13481 from the status messages produced by certain types of modems.
13483 @item @code{skip-login?} (default: @code{#f})
13484 When set to @code{#t}, do not prompt the user for a login name. This
13485 can be used with @var{login-program} field to use non-standard login
13488 @item @code{no-newline?} (default: @code{#f})
13489 When set to @code{#t}, do not print a newline before printing the
13490 @file{/etc/issue} file.
13492 @c Is this dangerous only when used with login-program, or always?
13493 @item @code{login-options} (default: @code{#f})
13494 This option accepts a string containing options that are passed to the
13495 login program. When used with the @var{login-program}, be aware that a
13496 malicious user could try to enter a login name containing embedded
13497 options that could be parsed by the login program.
13499 @item @code{login-pause} (default: @code{#f})
13500 When set to @code{#t}, wait for any key before showing the login prompt.
13501 This can be used in conjunction with @var{auto-login} to save memory by
13502 lazily spawning shells.
13504 @item @code{chroot} (default: @code{#f})
13505 Change root to the specified directory. This option accepts a directory
13508 @item @code{hangup?} (default: @code{#f})
13509 Use the Linux system call @code{vhangup} to do a virtual hangup of the
13510 specified terminal.
13512 @item @code{keep-baud?} (default: @code{#f})
13513 When set to @code{#t}, try to keep the existing baud rate. The baud
13514 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
13517 @item @code{timeout} (default: @code{#f})
13518 When set to an integer value, terminate if no user name could be read
13519 within @var{timeout} seconds.
13521 @item @code{detect-case?} (default: @code{#f})
13522 When set to @code{#t}, turn on support for detecting an uppercase-only
13523 terminal. This setting will detect a login name containing only
13524 uppercase letters as indicating an uppercase-only terminal and turn on
13525 some upper-to-lower case conversions. Note that this will not support
13526 Unicode characters.
13528 @item @code{wait-cr?} (default: @code{#f})
13529 When set to @code{#t}, wait for the user or modem to send a
13530 carriage-return or linefeed character before displaying
13531 @file{/etc/issue} or login prompt. This is typically used with the
13532 @var{init-string} option.
13534 @item @code{no-hints?} (default: @code{#f})
13535 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
13538 @item @code{no-hostname?} (default: @code{#f})
13539 By default, the hostname is printed. When this option is set to
13540 @code{#t}, no hostname will be shown at all.
13542 @item @code{long-hostname?} (default: @code{#f})
13543 By default, the hostname is only printed until the first dot. When this
13544 option is set to @code{#t}, the fully qualified hostname by
13545 @code{gethostname} or @code{getaddrinfo} is shown.
13547 @item @code{erase-characters} (default: @code{#f})
13548 This option accepts a string of additional characters that should be
13549 interpreted as backspace when the user types their login name.
13551 @item @code{kill-characters} (default: @code{#f})
13552 This option accepts a string that should be interpreted to mean ``ignore
13553 all previous characters'' (also called a ``kill'' character) when the user
13554 types their login name.
13556 @item @code{chdir} (default: @code{#f})
13557 This option accepts, as a string, a directory path that will be changed
13560 @item @code{delay} (default: @code{#f})
13561 This options accepts, as an integer, the number of seconds to sleep
13562 before opening the tty and displaying the login prompt.
13564 @item @code{nice} (default: @code{#f})
13565 This option accepts, as an integer, the nice value with which to run the
13566 @command{login} program.
13568 @item @code{extra-options} (default: @code{'()})
13569 This option provides an ``escape hatch'' for the user to provide arbitrary
13570 command-line arguments to @command{agetty} as a list of strings.
13575 @deffn {Scheme Procedure} kmscon-service-type @var{config}
13576 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
13577 according to @var{config}, a @code{<kmscon-configuration>} object, which
13578 specifies the tty to run, among other things.
13581 @deftp {Data Type} kmscon-configuration
13582 This is the data type representing the configuration of Kmscon, which
13583 implements virtual console log-in.
13587 @item @code{virtual-terminal}
13588 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
13590 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
13591 A gexp denoting the name of the log-in program. The default log-in program is
13592 @command{login} from the Shadow tool suite.
13594 @item @code{login-arguments} (default: @code{'("-p")})
13595 A list of arguments to pass to @command{login}.
13597 @item @code{auto-login} (default: @code{#f})
13598 When passed a login name, as a string, the specified user will be logged
13599 in automatically without prompting for their login name or password.
13601 @item @code{hardware-acceleration?} (default: #f)
13602 Whether to use hardware acceleration.
13604 @item @code{kmscon} (default: @var{kmscon})
13605 The Kmscon package to use.
13610 @cindex name service cache daemon
13612 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
13613 [#:name-services '()]
13614 Return a service that runs the libc name service cache daemon (nscd) with the
13615 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
13616 Service Switch}, for an example.
13618 For convenience, the Shepherd service for nscd provides the following actions:
13622 @cindex cache invalidation, nscd
13623 @cindex nscd, cache invalidation
13624 This invalidate the given cache. For instance, running:
13627 herd invalidate nscd hosts
13631 invalidates the host name lookup cache of nscd.
13634 Running @command{herd statistics nscd} displays information about nscd usage
13640 @defvr {Scheme Variable} %nscd-default-configuration
13641 This is the default @code{<nscd-configuration>} value (see below) used
13642 by @code{nscd-service}. It uses the caches defined by
13643 @code{%nscd-default-caches}; see below.
13646 @deftp {Data Type} nscd-configuration
13647 This is the data type representing the name service cache daemon (nscd)
13652 @item @code{name-services} (default: @code{'()})
13653 List of packages denoting @dfn{name services} that must be visible to
13654 the nscd---e.g., @code{(list @var{nss-mdns})}.
13656 @item @code{glibc} (default: @var{glibc})
13657 Package object denoting the GNU C Library providing the @command{nscd}
13660 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
13661 Name of the nscd log file. This is where debugging output goes when
13662 @code{debug-level} is strictly positive.
13664 @item @code{debug-level} (default: @code{0})
13665 Integer denoting the debugging levels. Higher numbers mean that more
13666 debugging output is logged.
13668 @item @code{caches} (default: @code{%nscd-default-caches})
13669 List of @code{<nscd-cache>} objects denoting things to be cached; see
13675 @deftp {Data Type} nscd-cache
13676 Data type representing a cache database of nscd and its parameters.
13680 @item @code{database}
13681 This is a symbol representing the name of the database to be cached.
13682 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
13683 @code{services}, which designate the corresponding NSS database
13684 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
13686 @item @code{positive-time-to-live}
13687 @itemx @code{negative-time-to-live} (default: @code{20})
13688 A number representing the number of seconds during which a positive or
13689 negative lookup result remains in cache.
13691 @item @code{check-files?} (default: @code{#t})
13692 Whether to check for updates of the files corresponding to
13695 For instance, when @var{database} is @code{hosts}, setting this flag
13696 instructs nscd to check for updates in @file{/etc/hosts} and to take
13699 @item @code{persistent?} (default: @code{#t})
13700 Whether the cache should be stored persistently on disk.
13702 @item @code{shared?} (default: @code{#t})
13703 Whether the cache should be shared among users.
13705 @item @code{max-database-size} (default: 32@tie{}MiB)
13706 Maximum size in bytes of the database cache.
13708 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
13709 @c settings, so leave them out.
13714 @defvr {Scheme Variable} %nscd-default-caches
13715 List of @code{<nscd-cache>} objects used by default by
13716 @code{nscd-configuration} (see above).
13718 It enables persistent and aggressive caching of service and host name
13719 lookups. The latter provides better host name lookup performance,
13720 resilience in the face of unreliable name servers, and also better
13721 privacy---often the result of host name lookups is in local cache, so
13722 external name servers do not even need to be queried.
13725 @anchor{syslog-configuration-type}
13728 @deftp {Data Type} syslog-configuration
13729 This data type represents the configuration of the syslog daemon.
13732 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
13733 The syslog daemon to use.
13735 @item @code{config-file} (default: @code{%default-syslog.conf})
13736 The syslog configuration file to use.
13741 @anchor{syslog-service}
13743 @deffn {Scheme Procedure} syslog-service @var{config}
13744 Return a service that runs a syslog daemon according to @var{config}.
13746 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
13747 information on the configuration file syntax.
13750 @defvr {Scheme Variable} guix-service-type
13751 This is the type of the service that runs the build daemon,
13752 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
13753 @code{guix-configuration} record as described below.
13756 @anchor{guix-configuration-type}
13757 @deftp {Data Type} guix-configuration
13758 This data type represents the configuration of the Guix build daemon.
13759 @xref{Invoking guix-daemon}, for more information.
13762 @item @code{guix} (default: @var{guix})
13763 The Guix package to use.
13765 @item @code{build-group} (default: @code{"guixbuild"})
13766 Name of the group for build user accounts.
13768 @item @code{build-accounts} (default: @code{10})
13769 Number of build user accounts to create.
13771 @item @code{authorize-key?} (default: @code{#t})
13772 @cindex substitutes, authorization thereof
13773 Whether to authorize the substitute keys listed in
13774 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
13775 (@pxref{Substitutes}).
13777 @vindex %default-authorized-guix-keys
13778 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
13779 The list of authorized key files for archive imports, as a list of
13780 string-valued gexps (@pxref{Invoking guix archive}). By default, it
13781 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
13783 @item @code{use-substitutes?} (default: @code{#t})
13784 Whether to use substitutes.
13786 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
13787 The list of URLs where to look for substitutes by default.
13789 @item @code{max-silent-time} (default: @code{0})
13790 @itemx @code{timeout} (default: @code{0})
13791 The number of seconds of silence and the number of seconds of activity,
13792 respectively, after which a build process times out. A value of zero
13793 disables the timeout.
13795 @item @code{log-compression} (default: @code{'bzip2})
13796 The type of compression used for build logs---one of @code{gzip},
13797 @code{bzip2}, or @code{none}.
13799 @item @code{extra-options} (default: @code{'()})
13800 List of extra command-line options for @command{guix-daemon}.
13802 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
13803 File where @command{guix-daemon}'s standard output and standard error
13806 @cindex HTTP proxy, for @code{guix-daemon}
13807 @cindex proxy, for @code{guix-daemon} HTTP access
13808 @item @code{http-proxy} (default: @code{#f})
13809 The URL of the HTTP and HTTPS proxy used for downloading fixed-output
13810 derivations and substitutes.
13812 It is also possible to change the daemon's proxy at run time through the
13813 @code{set-http-proxy} action, which restarts it:
13816 herd set-http-proxy guix-daemon http://localhost:8118
13819 To clear the proxy settings, run:
13822 herd set-http-proxy guix-daemon
13825 @item @code{tmpdir} (default: @code{#f})
13826 A directory path where the @command{guix-daemon} will perform builds.
13831 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
13832 Run @var{udev}, which populates the @file{/dev} directory dynamically.
13833 udev rules can be provided as a list of files through the @var{rules}
13834 variable. The procedures @code{udev-rule}, @code{udev-rules-service}
13835 and @code{file->udev-rule} from @code{(gnu services base)} simplify the
13836 creation of such rule files.
13838 The @command{herd rules udev} command, as root, returns the name of the
13839 directory containing all the active udev rules.
13842 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
13843 Return a udev-rule file named @var{file-name} containing the rules
13844 defined by the @var{contents} literal.
13846 In the following example, a rule for a USB device is defined to be
13847 stored in the file @file{90-usb-thing.rules}. The rule runs a script
13848 upon detecting a USB device with a given product identifier.
13851 (define %example-udev-rule
13853 "90-usb-thing.rules"
13854 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
13855 "ATTR@{product@}==\"Example\", "
13856 "RUN+=\"/path/to/script\"")))
13860 @deffn {Scheme Procedure} udev-rules-service [@var{name} @var{rules}] @
13861 [#:groups @var{groups}]
13862 Return a service that extends @code{udev-service-type } with @var{rules}
13863 and @code{account-service-type} with @var{groups} as system groups.
13864 This works by creating a singleton service type
13865 @code{@var{name}-udev-rules}, of which the returned service is an
13868 Here we show how it can be used to extend @code{udev-service-type} with the
13869 previously defined rule @code{%example-udev-rule}.
13875 (cons (udev-rules-service 'usb-thing %example-udev-rule)
13876 %desktop-services)))
13880 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
13881 Return a udev file named @var{file-name} containing the rules defined
13882 within @var{file}, a file-like object.
13884 The following example showcases how we can use an existing rule file.
13887 (use-modules (guix download) ;for url-fetch
13888 (guix packages) ;for origin
13891 (define %android-udev-rules
13893 "51-android-udev.rules"
13894 (let ((version "20170910"))
13897 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
13898 "android-udev-rules/" version "/51-android.rules"))
13900 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
13904 Additionally, Guix package definitions can be included in @var{rules} in
13905 order to extend the udev rules with the definitions found under their
13906 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
13907 @var{file->udev-rule} example, we could have used the
13908 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
13909 packages android)} module.
13911 The following example shows how to use the @var{android-udev-rules}
13912 package so that the Android tool @command{adb} can detect devices
13913 without root privileges. It also details how to create the
13914 @code{adbusers} group, which is required for the proper functioning of
13915 the rules defined within the @code{android-udev-rules} package. To
13916 create such a group, we must define it both as part of the
13917 @code{supplementary-groups} of our @code{user-account} declaration, as
13918 well as in the @var{groups} of the @code{udev-rules-service} procedure.
13921 (use-modules (gnu packages android) ;for android-udev-rules
13922 (gnu system shadow) ;for user-group
13927 (users (cons (user-account
13929 (supplementary-groups
13930 '("adbusers" ;for adb
13931 "wheel" "netdev" "audio" "video")))))
13934 (cons (udev-rules-service 'android android-udev-rules
13935 #:groups '("adbusers"))
13936 %desktop-services)))
13939 @defvr {Scheme Variable} urandom-seed-service-type
13940 Save some entropy in @code{%random-seed-file} to seed @file{/dev/urandom}
13941 when rebooting. It also tries to seed @file{/dev/urandom} from
13942 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
13946 @defvr {Scheme Variable} %random-seed-file
13947 This is the name of the file where some random bytes are saved by
13948 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
13949 It defaults to @file{/var/lib/random-seed}.
13954 @defvr {Scheme Variable} gpm-service-type
13955 This is the type of the service that runs GPM, the @dfn{general-purpose
13956 mouse daemon}, which provides mouse support to the Linux console. GPM
13957 allows users to use the mouse in the console, notably to select, copy,
13960 The value for services of this type must be a @code{gpm-configuration}
13961 (see below). This service is not part of @code{%base-services}.
13964 @deftp {Data Type} gpm-configuration
13965 Data type representing the configuration of GPM.
13968 @item @code{options} (default: @code{%default-gpm-options})
13969 Command-line options passed to @command{gpm}. The default set of
13970 options instruct @command{gpm} to listen to mouse events on
13971 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
13974 @item @code{gpm} (default: @code{gpm})
13975 The GPM package to use.
13980 @anchor{guix-publish-service-type}
13981 @deffn {Scheme Variable} guix-publish-service-type
13982 This is the service type for @command{guix publish} (@pxref{Invoking
13983 guix publish}). Its value must be a @code{guix-publish-configuration}
13984 object, as described below.
13986 This assumes that @file{/etc/guix} already contains a signing key pair as
13987 created by @command{guix archive --generate-key} (@pxref{Invoking guix
13988 archive}). If that is not the case, the service will fail to start.
13991 @deftp {Data Type} guix-publish-configuration
13992 Data type representing the configuration of the @code{guix publish}
13996 @item @code{guix} (default: @code{guix})
13997 The Guix package to use.
13999 @item @code{port} (default: @code{80})
14000 The TCP port to listen for connections.
14002 @item @code{host} (default: @code{"localhost"})
14003 The host (and thus, network interface) to listen to. Use
14004 @code{"0.0.0.0"} to listen on all the network interfaces.
14006 @item @code{compression} (default: @code{'(("gzip" 3))})
14007 This is a list of compression method/level tuple used when compressing
14008 substitutes. For example, to compress all substitutes with @emph{both} lzip
14009 at level 7 and gzip at level 9, write:
14012 '(("lzip" 7) ("gzip" 9))
14015 Level 9 achieves the best compression ratio at the expense of increased CPU
14016 usage, whereas level 1 achieves fast compression.
14018 An empty list disables compression altogether.
14020 @item @code{nar-path} (default: @code{"nar"})
14021 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
14022 publish, @option{--nar-path}}, for details.
14024 @item @code{cache} (default: @code{#f})
14025 When it is @code{#f}, disable caching and instead generate archives on
14026 demand. Otherwise, this should be the name of a directory---e.g.,
14027 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
14028 archives and meta-data ready to be sent. @xref{Invoking guix publish,
14029 @option{--cache}}, for more information on the tradeoffs involved.
14031 @item @code{workers} (default: @code{#f})
14032 When it is an integer, this is the number of worker threads used for
14033 caching; when @code{#f}, the number of processors is used.
14034 @xref{Invoking guix publish, @option{--workers}}, for more information.
14036 @item @code{ttl} (default: @code{#f})
14037 When it is an integer, this denotes the @dfn{time-to-live} in seconds
14038 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
14039 for more information.
14043 @anchor{rngd-service}
14044 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
14045 [#:device "/dev/hwrng"]
14046 Return a service that runs the @command{rngd} program from @var{rng-tools}
14047 to add @var{device} to the kernel's entropy pool. The service will fail if
14048 @var{device} does not exist.
14051 @anchor{pam-limits-service}
14052 @cindex session limits
14057 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
14059 Return a service that installs a configuration file for the
14060 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
14061 @code{pam_limits} module}. The procedure optionally takes a list of
14062 @code{pam-limits-entry} values, which can be used to specify
14063 @code{ulimit} limits and nice priority limits to user sessions.
14065 The following limits definition sets two hard and soft limits for all
14066 login sessions of users in the @code{realtime} group:
14069 (pam-limits-service
14071 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
14072 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
14075 The first entry increases the maximum realtime priority for
14076 non-privileged processes; the second entry lifts any restriction of the
14077 maximum address space that can be locked in memory. These settings are
14078 commonly used for real-time audio systems.
14081 @node Scheduled Job Execution
14082 @subsection Scheduled Job Execution
14086 @cindex scheduling jobs
14087 The @code{(gnu services mcron)} module provides an interface to
14088 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
14089 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
14090 Unix @command{cron} daemon; the main difference is that it is
14091 implemented in Guile Scheme, which provides a lot of flexibility when
14092 specifying the scheduling of jobs and their actions.
14094 The example below defines an operating system that runs the
14095 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
14096 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
14097 well as the @command{mkid} command on behalf of an unprivileged user
14098 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
14099 gexps to introduce job definitions that are passed to mcron
14100 (@pxref{G-Expressions}).
14103 (use-modules (guix) (gnu) (gnu services mcron))
14104 (use-package-modules base idutils)
14106 (define updatedb-job
14107 ;; Run 'updatedb' at 3AM every day. Here we write the
14108 ;; job's action as a Scheme procedure.
14109 #~(job '(next-hour '(3))
14111 (execl (string-append #$findutils "/bin/updatedb")
14113 "--prunepaths=/tmp /var/tmp /gnu/store"))))
14115 (define garbage-collector-job
14116 ;; Collect garbage 5 minutes after midnight every day.
14117 ;; The job's action is a shell command.
14118 #~(job "5 0 * * *" ;Vixie cron syntax
14121 (define idutils-job
14122 ;; Update the index database as user "charlie" at 12:15PM
14123 ;; and 19:15PM. This runs from the user's home directory.
14124 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
14125 (string-append #$idutils "/bin/mkid src")
14130 (services (cons (service mcron-service-type
14131 (mcron-configuration
14132 (jobs (list garbage-collector-job
14138 For more complex jobs defined in Scheme where you need control over the top
14139 level, for instance to introduce a @code{use-modules} form, you can move your
14140 code to a separate program using the @code{program-file} procedure of the
14141 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
14145 (define %battery-alert-job
14146 ;; Beep when the battery percentage falls below %MIN-LEVEL.
14148 '(next-minute (range 0 60 1))
14150 "battery-alert.scm"
14151 (with-imported-modules (source-module-closure
14152 '((guix build utils)))
14154 (use-modules (guix build utils)
14157 (ice-9 textual-ports)
14160 (define %min-level 20)
14162 (setenv "LC_ALL" "C") ;ensure English output
14163 (and-let* ((input-pipe (open-pipe*
14165 #$(file-append acpi "/bin/acpi")))
14166 (output (get-string-all input-pipe))
14167 (m (string-match "Discharging, ([0-9]+)%" output))
14168 (level (string->number (match:substring m 1)))
14169 ((< level %min-level)))
14170 (format #t "warning: Battery level is low (~a%)~%" level)
14171 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
14174 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
14175 for more information on mcron job specifications. Below is the
14176 reference of the mcron service.
14178 On a running system, you can use the @code{schedule} action of the service to
14179 visualize the mcron jobs that will be executed next:
14182 # herd schedule mcron
14186 The example above lists the next five tasks that will be executed, but you can
14187 also specify the number of tasks to display:
14190 # herd schedule mcron 10
14193 @defvr {Scheme Variable} mcron-service-type
14194 This is the type of the @code{mcron} service, whose value is an
14195 @code{mcron-configuration} object.
14197 This service type can be the target of a service extension that provides
14198 it additional job specifications (@pxref{Service Composition}). In
14199 other words, it is possible to define services that provide additional
14203 @deftp {Data Type} mcron-configuration
14204 Data type representing the configuration of mcron.
14207 @item @code{mcron} (default: @var{mcron})
14208 The mcron package to use.
14211 This is a list of gexps (@pxref{G-Expressions}), where each gexp
14212 corresponds to an mcron job specification (@pxref{Syntax, mcron job
14213 specifications,, mcron, GNU@tie{}mcron}).
14219 @subsection Log Rotation
14222 @cindex log rotation
14224 Log files such as those found in @file{/var/log} tend to grow endlessly,
14225 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
14226 their contents in separate files, possibly compressed. The @code{(gnu
14227 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
14228 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
14230 This service is part of @code{%base-services}, and thus enabled by
14231 default, with the default settings, for commonly encountered log files.
14232 The example below shows how to extend it with an additional
14233 @dfn{rotation}, should you need to do that (usually, services that
14234 produce log files already take care of that):
14237 (use-modules (guix) (gnu))
14238 (use-service-modules admin)
14240 (define my-log-files
14241 ;; Log files that I want to rotate.
14242 '("/var/log/something.log" "/var/log/another.log"))
14246 (services (cons (simple-service 'rotate-my-stuff
14247 rottlog-service-type
14248 (list (log-rotation
14250 (files my-log-files))))
14254 @defvr {Scheme Variable} rottlog-service-type
14255 This is the type of the Rottlog service, whose value is a
14256 @code{rottlog-configuration} object.
14258 Other services can extend this one with new @code{log-rotation} objects
14259 (see below), thereby augmenting the set of files to be rotated.
14261 This service type can define mcron jobs (@pxref{Scheduled Job
14262 Execution}) to run the rottlog service.
14265 @deftp {Data Type} rottlog-configuration
14266 Data type representing the configuration of rottlog.
14269 @item @code{rottlog} (default: @code{rottlog})
14270 The Rottlog package to use.
14272 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
14273 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
14274 rottlog, GNU Rot[t]log Manual}).
14276 @item @code{rotations} (default: @code{%default-rotations})
14277 A list of @code{log-rotation} objects as defined below.
14280 This is a list of gexps where each gexp corresponds to an mcron job
14281 specification (@pxref{Scheduled Job Execution}).
14285 @deftp {Data Type} log-rotation
14286 Data type representing the rotation of a group of log files.
14288 Taking an example from the Rottlog manual (@pxref{Period Related File
14289 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
14295 (files '("/var/log/apache/*"))
14296 (options '("storedir apache-archives"
14302 The list of fields is as follows:
14305 @item @code{frequency} (default: @code{'weekly})
14306 The log rotation frequency, a symbol.
14309 The list of files or file glob patterns to rotate.
14311 @item @code{options} (default: @code{'()})
14312 The list of rottlog options for this rotation (@pxref{Configuration
14313 parameters,,, rottlog, GNU Rot[t]lg Manual}).
14315 @item @code{post-rotate} (default: @code{#f})
14316 Either @code{#f} or a gexp to execute once the rotation has completed.
14320 @defvr {Scheme Variable} %default-rotations
14321 Specifies weekly rotation of @code{%rotated-files} and of
14322 @file{/var/log/guix-daemon.log}.
14325 @defvr {Scheme Variable} %rotated-files
14326 The list of syslog-controlled files to be rotated. By default it is:
14327 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
14328 "/var/log/maillog")}.
14331 @node Networking Services
14332 @subsection Networking Services
14334 The @code{(gnu services networking)} module provides services to configure
14335 the network interface.
14337 @cindex DHCP, networking service
14338 @defvr {Scheme Variable} dhcp-client-service-type
14339 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
14340 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
14341 is the DHCP client package to use, @code{isc-dhcp} by default.
14344 @deffn {Scheme Procedure} dhcpd-service-type
14345 This type defines a service that runs a DHCP daemon. To create a
14346 service of this type, you must supply a @code{<dhcpd-configuration>}.
14350 (service dhcpd-service-type
14351 (dhcpd-configuration
14352 (config-file (local-file "my-dhcpd.conf"))
14353 (interfaces '("enp0s25"))))
14357 @deftp {Data Type} dhcpd-configuration
14359 @item @code{package} (default: @code{isc-dhcp})
14360 The package that provides the DHCP daemon. This package is expected to
14361 provide the daemon at @file{sbin/dhcpd} relative to its output
14362 directory. The default package is the
14363 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
14364 @item @code{config-file} (default: @code{#f})
14365 The configuration file to use. This is required. It will be passed to
14366 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
14367 object (@pxref{G-Expressions, file-like objects}). See @code{man
14368 dhcpd.conf} for details on the configuration file syntax.
14369 @item @code{version} (default: @code{"4"})
14370 The DHCP version to use. The ISC DHCP server supports the values ``4'',
14371 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
14372 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
14374 @item @code{run-directory} (default: @code{"/run/dhcpd"})
14375 The run directory to use. At service activation time, this directory
14376 will be created if it does not exist.
14377 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
14378 The PID file to use. This corresponds to the @code{-pf} option of
14379 @code{dhcpd}. See @code{man dhcpd} for details.
14380 @item @code{interfaces} (default: @code{'()})
14381 The names of the network interfaces on which dhcpd should listen for
14382 broadcasts. If this list is not empty, then its elements (which must be
14383 strings) will be appended to the @code{dhcpd} invocation when starting
14384 the daemon. It may not be necessary to explicitly specify any
14385 interfaces here; see @code{man dhcpd} for details.
14389 @defvr {Scheme Variable} static-networking-service-type
14390 This is the type for statically-configured network interfaces.
14391 @c TODO Document <static-networking> data structures.
14394 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
14395 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
14396 [#:requirement @code{'(udev)}]
14397 Return a service that starts @var{interface} with address @var{ip}. If
14398 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
14399 it must be a string specifying the default network gateway. @var{requirement}
14400 can be used to declare a dependency on another service before configuring the
14403 This procedure can be called several times, one for each network
14404 interface of interest. Behind the scenes what it does is extend
14405 @code{static-networking-service-type} with additional network interfaces
14411 (static-networking-service "eno1" "192.168.1.82"
14412 #:gateway "192.168.1.2"
14413 #:name-servers '("192.168.1.2"))
14420 @cindex network management
14421 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
14422 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
14423 management daemon that aims to simplify wired and wireless networking.
14425 This service adds the @var{wicd} package to the global profile, providing
14426 several commands to interact with the daemon and configure networking:
14427 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
14428 and @command{wicd-curses} user interfaces.
14431 @cindex ModemManager
14433 @defvr {Scheme Variable} modem-manager-service-type
14434 This is the service type for the
14435 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
14436 service. The value for this service type is a
14437 @code{modem-manager-configuration} record.
14439 This service is part of @code{%desktop-services} (@pxref{Desktop
14443 @deftp {Data Type} modem-manager-configuration
14444 Data type representing the configuration of ModemManager.
14447 @item @code{modem-manager} (default: @code{modem-manager})
14448 The ModemManager package to use.
14453 @cindex USB_ModeSwitch
14454 @cindex Modeswitching
14456 @defvr {Scheme Variable} usb-modeswitch-service-type
14457 This is the service type for the
14458 @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch} service. The
14459 value for this service type is a @code{usb-modeswitch-configuration} record.
14461 When plugged in, some USB modems (and other USB devices) initially present
14462 themselves as a read-only storage medium and not as a modem. They need to be
14463 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
14464 installs udev rules to automatically modeswitch these devices when they are
14467 This service is part of @code{%desktop-services} (@pxref{Desktop
14471 @deftp {Data Type} usb-modeswitch-configuration
14472 Data type representing the configuration of USB_ModeSwitch.
14475 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
14476 The USB_ModeSwitch package providing the binaries for modeswitching.
14478 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
14479 The package providing the device data and udev rules file used by
14482 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
14483 Which config file to use for the USB_ModeSwitch dispatcher. By default the
14484 config file shipped with USB_ModeSwitch is used which disables logging to
14485 @file{/var/log} among other default settings. If set to @code{#f}, no config
14491 @cindex NetworkManager
14493 @defvr {Scheme Variable} network-manager-service-type
14494 This is the service type for the
14495 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
14496 service. The value for this service type is a
14497 @code{network-manager-configuration} record.
14499 This service is part of @code{%desktop-services} (@pxref{Desktop
14503 @deftp {Data Type} network-manager-configuration
14504 Data type representing the configuration of NetworkManager.
14507 @item @code{network-manager} (default: @code{network-manager})
14508 The NetworkManager package to use.
14510 @item @code{dns} (default: @code{"default"})
14511 Processing mode for DNS, which affects how NetworkManager uses the
14512 @code{resolv.conf} configuration file.
14516 NetworkManager will update @code{resolv.conf} to reflect the nameservers
14517 provided by currently active connections.
14520 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
14521 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
14522 then update @code{resolv.conf} to point to the local nameserver.
14524 With this setting, you can share your network connection. For example when
14525 you want to share your network connection to another laptop @i{via} an
14526 Ethernet cable, you can open @command{nm-connection-editor} and configure the
14527 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
14528 and reestablish the connection (or reboot).
14530 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
14531 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
14532 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
14533 browser on your host system, or connect to the VM @i{via} SSH
14534 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
14535 host-to-guest connection, run this command once:
14538 nmcli connection add type tun \
14539 connection.interface-name tap0 \
14540 tun.mode tap tun.owner $(id -u) \
14541 ipv4.method shared \
14542 ipv4.addresses 172.28.112.1/24
14545 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
14546 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
14547 @command{qemu-system-...}.
14550 NetworkManager will not modify @code{resolv.conf}.
14553 @item @code{vpn-plugins} (default: @code{'()})
14554 This is the list of available plugins for virtual private networks
14555 (VPNs). An example of this is the @code{network-manager-openvpn}
14556 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
14562 @deffn {Scheme Variable} connman-service-type
14563 This is the service type to run @url{https://01.org/connman,Connman},
14564 a network connection manager.
14566 Its value must be an
14567 @code{connman-configuration} record as in this example:
14570 (service connman-service-type
14571 (connman-configuration
14572 (disable-vpn? #t)))
14575 See below for details about @code{connman-configuration}.
14578 @deftp {Data Type} connman-configuration
14579 Data Type representing the configuration of connman.
14582 @item @code{connman} (default: @var{connman})
14583 The connman package to use.
14585 @item @code{disable-vpn?} (default: @code{#f})
14586 When true, disable connman's vpn plugin.
14590 @cindex WPA Supplicant
14591 @defvr {Scheme Variable} wpa-supplicant-service-type
14592 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
14593 supplicant}, an authentication daemon required to authenticate against
14594 encrypted WiFi or ethernet networks.
14597 @deftp {Data Type} wpa-supplicant-configuration
14598 Data type representing the configuration of WPA Supplicant.
14600 It takes the following parameters:
14603 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
14604 The WPA Supplicant package to use.
14606 @item @code{requirement} (default: @code{'(user-processes loopback syslogd)}
14607 List of services that should be started before WPA Supplicant starts.
14609 @item @code{dbus?} (default: @code{#t})
14610 Whether to listen for requests on D-Bus.
14612 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
14613 Where to store the PID file.
14615 @item @code{interface} (default: @code{#f})
14616 If this is set, it must specify the name of a network interface that
14617 WPA supplicant will control.
14619 @item @code{config-file} (default: @code{#f})
14620 Optional configuration file to use.
14622 @item @code{extra-options} (default: @code{'()})
14623 List of additional command-line arguments to pass to the daemon.
14627 @cindex hostapd service, for Wi-Fi access points
14628 @cindex Wi-Fi access points, hostapd service
14629 @defvr {Scheme Variable} hostapd-service-type
14630 This is the service type to run the @uref{https://w1.fi/hostapd/,
14631 hostapd} daemon to set up WiFi (IEEE 802.11) access points and
14632 authentication servers. Its associated value must be a
14633 @code{hostapd-configuration} as shown below:
14636 ;; Use wlan1 to run the access point for "My Network".
14637 (service hostapd-service-type
14638 (hostapd-configuration
14639 (interface "wlan1")
14640 (ssid "My Network")
14645 @deftp {Data Type} hostapd-configuration
14646 This data type represents the configuration of the hostapd service, with
14647 the following fields:
14650 @item @code{package} (default: @code{hostapd})
14651 The hostapd package to use.
14653 @item @code{interface} (default: @code{"wlan0"})
14654 The network interface to run the WiFi access point.
14657 The SSID (@dfn{service set identifier}), a string that identifies this
14660 @item @code{broadcast-ssid?} (default: @code{#t})
14661 Whether to broadcast this SSID.
14663 @item @code{channel} (default: @code{1})
14664 The WiFi channel to use.
14666 @item @code{driver} (default: @code{"nl80211"})
14667 The driver interface type. @code{"nl80211"} is used with all Linux
14668 mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
14669 RADIUS server that does # not control any wireless/wired driver.
14671 @item @code{extra-settings} (default: @code{""})
14672 Extra settings to append as-is to the hostapd configuration file. See
14673 @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
14674 configuration file reference.
14678 @defvr {Scheme Variable} simulated-wifi-service-type
14679 This is the type of a service to simulate WiFi networking, which can be
14680 useful in virtual machines for testing purposes. The service loads the
14682 @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
14683 @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
14684 network that can be seen on @code{wlan0}, by default.
14686 The service's value is a @code{hostapd-configuration} record.
14690 @defvr {Scheme Variable} iptables-service-type
14691 This is the service type to set up an iptables configuration. iptables is a
14692 packet filtering framework supported by the Linux kernel. This service
14693 supports configuring iptables for both IPv4 and IPv6. A simple example
14694 configuration rejecting all incoming connections except those to the ssh port
14698 (service iptables-service-type
14699 (iptables-configuration
14700 (ipv4-rules (plain-file "iptables.rules" "*filter
14704 -A INPUT -p tcp --dport 22 -j ACCEPT
14705 -A INPUT -j REJECT --reject-with icmp-port-unreachable
14708 (ipv6-rules (plain-file "ip6tables.rules" "*filter
14712 -A INPUT -p tcp --dport 22 -j ACCEPT
14713 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
14719 @deftp {Data Type} iptables-configuration
14720 The data type representing the configuration of iptables.
14723 @item @code{iptables} (default: @code{iptables})
14724 The iptables package that provides @code{iptables-restore} and
14725 @code{ip6tables-restore}.
14726 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
14727 The iptables rules to use. It will be passed to @code{iptables-restore}.
14728 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
14730 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
14731 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
14732 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
14738 @defvr {Scheme Variable} nftables-service-type
14739 This is the service type to set up a nftables configuration. nftables is a
14740 netfilter project that aims to replace the existing iptables, ip6tables,
14741 arptables and ebtables framework. It provides a new packet filtering
14742 framework, a new user-space utility @command{nft}, and a compatibility layer
14743 for iptables. This service comes with a default ruleset
14744 @code{%default-nftables-ruleset} that rejecting all incomming connections
14745 except those to the ssh port 22. To use it, simply write:
14748 (service nftables-service-type)
14752 @deftp {Data Type} nftables-configuration
14753 The data type representing the configuration of nftables.
14756 @item @code{package} (default: @code{nftables})
14757 The nftables package that provides @command{nft}.
14758 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
14759 The nftables ruleset to use. This may be any ``file-like'' object
14760 (@pxref{G-Expressions, file-like objects}).
14764 @cindex NTP (Network Time Protocol), service
14765 @cindex ntpd, service for the Network Time Protocol daemon
14766 @cindex real time clock
14767 @defvr {Scheme Variable} ntp-service-type
14768 This is the type of the service running the @uref{https://www.ntp.org,
14769 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
14770 system clock synchronized with that of the specified NTP servers.
14772 The value of this service is an @code{ntpd-configuration} object, as described
14776 @deftp {Data Type} ntp-configuration
14777 This is the data type for the NTP service configuration.
14780 @item @code{servers} (default: @code{%ntp-servers})
14781 This is the list of servers (@code{<ntp-server>} records) with which
14782 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
14785 @item @code{allow-large-adjustment?} (default: @code{#t})
14786 This determines whether @command{ntpd} is allowed to make an initial
14787 adjustment of more than 1,000 seconds.
14789 @item @code{ntp} (default: @code{ntp})
14790 The NTP package to use.
14794 @defvr {Scheme Variable} %ntp-servers
14795 List of host names used as the default NTP servers. These are servers of the
14796 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
14799 @deftp {Data Type} ntp-server
14800 The data type representing the configuration of a NTP server.
14803 @item @code{type} (default: @code{'server})
14804 The type of the NTP server, given as a symbol. One of @code{'pool},
14805 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
14807 @item @code{address}
14808 The address of the server, as a string.
14810 @item @code{options}
14811 NTPD options to use with that specific server, given as a list of option names
14812 and/or of option names and values tuples. The following example define a server
14813 to use with the options @option{iburst} and @option{prefer}, as well as
14814 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
14819 (address "some.ntp.server.org")
14820 (options `(iburst (version 3) (maxpoll 16) prefer))))
14826 @deffn {Scheme Procedure} openntpd-service-type
14827 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
14828 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
14829 clock synchronized with that of the given servers.
14833 openntpd-service-type
14834 (openntpd-configuration
14835 (listen-on '("127.0.0.1" "::1"))
14836 (sensor '("udcf0 correction 70000"))
14837 (constraint-from '("www.gnu.org"))
14838 (constraints-from '("https://www.google.com/"))
14839 (allow-large-adjustment? #t)))
14844 @defvr {Scheme Variable} %openntpd-servers
14845 This variable is a list of the server addresses defined in
14846 @code{%ntp-servers}.
14849 @deftp {Data Type} openntpd-configuration
14851 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
14852 The openntpd executable to use.
14853 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
14854 A list of local IP addresses or hostnames the ntpd daemon should listen on.
14855 @item @code{query-from} (default: @code{'()})
14856 A list of local IP address the ntpd daemon should use for outgoing queries.
14857 @item @code{sensor} (default: @code{'()})
14858 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
14859 will listen to each sensor that actually exists and ignore non-existent ones.
14860 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
14862 @item @code{server} (default: @code{'()})
14863 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
14864 @item @code{servers} (default: @code{%openntp-servers})
14865 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
14866 @item @code{constraint-from} (default: @code{'()})
14867 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
14868 This time information is not used for precision but acts as an authenticated
14869 constraint, thereby reducing the impact of unauthenticated NTP
14870 man-in-the-middle attacks.
14871 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
14873 @item @code{constraints-from} (default: @code{'()})
14874 As with constraint from, specify a list of URLs, IP addresses or hostnames of
14875 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
14876 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
14877 @item @code{allow-large-adjustment?} (default: @code{#f})
14878 Determines if @code{ntpd} is allowed to make an initial adjustment of more
14884 @deffn {Scheme variable} inetd-service-type
14885 This service runs the @command{inetd} (@pxref{inetd invocation,,,
14886 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
14887 connections on internet sockets, and lazily starts the specified server
14888 program when a connection is made on one of these sockets.
14890 The value of this service is an @code{inetd-configuration} object. The
14891 following example configures the @command{inetd} daemon to provide the
14892 built-in @command{echo} service, as well as an smtp service which
14893 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
14894 gateway @code{hostname}:
14899 (inetd-configuration
14903 (socket-type 'stream)
14910 (socket-type 'stream)
14914 (program (file-append openssh "/bin/ssh"))
14916 '("ssh" "-qT" "-i" "/path/to/ssh_key"
14917 "-W" "smtp-server:25" "user@@hostname")))))))
14920 See below for more details about @code{inetd-configuration}.
14923 @deftp {Data Type} inetd-configuration
14924 Data type representing the configuration of @command{inetd}.
14927 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
14928 The @command{inetd} executable to use.
14930 @item @code{entries} (default: @code{'()})
14931 A list of @command{inetd} service entries. Each entry should be created
14932 by the @code{inetd-entry} constructor.
14936 @deftp {Data Type} inetd-entry
14937 Data type representing an entry in the @command{inetd} configuration.
14938 Each entry corresponds to a socket where @command{inetd} will listen for
14942 @item @code{node} (default: @code{#f})
14943 Optional string, a comma-separated list of local addresses
14944 @command{inetd} should use when listening for this service.
14945 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
14946 description of all options.
14948 A string, the name must correspond to an entry in @code{/etc/services}.
14949 @item @code{socket-type}
14950 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
14952 @item @code{protocol}
14953 A string, must correspond to an entry in @code{/etc/protocols}.
14954 @item @code{wait?} (default: @code{#t})
14955 Whether @command{inetd} should wait for the server to exit before
14956 listening to new service requests.
14958 A string containing the user (and, optionally, group) name of the user
14959 as whom the server should run. The group name can be specified in a
14960 suffix, separated by a colon or period, i.e.@: @code{"user"},
14961 @code{"user:group"} or @code{"user.group"}.
14962 @item @code{program} (default: @code{"internal"})
14963 The server program which will serve the requests, or @code{"internal"}
14964 if @command{inetd} should use a built-in service.
14965 @item @code{arguments} (default: @code{'()})
14966 A list strings or file-like objects, which are the server program's
14967 arguments, starting with the zeroth argument, i.e.@: the name of the
14968 program itself. For @command{inetd}'s internal services, this entry
14969 must be @code{'()} or @code{'("internal")}.
14972 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
14973 detailed discussion of each configuration field.
14977 @defvr {Scheme Variable} tor-service-type
14978 This is the type for a service that runs the @uref{https://torproject.org,
14979 Tor} anonymous networking daemon. The service is configured using a
14980 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
14981 @code{tor} unprivileged user, which is a member of the @code{tor} group.
14985 @deftp {Data Type} tor-configuration
14987 @item @code{tor} (default: @code{tor})
14988 The package that provides the Tor daemon. This package is expected to provide
14989 the daemon at @file{bin/tor} relative to its output directory. The default
14990 package is the @uref{https://www.torproject.org, Tor Project's}
14993 @item @code{config-file} (default: @code{(plain-file "empty" "")})
14994 The configuration file to use. It will be appended to a default configuration
14995 file, and the final configuration file will be passed to @code{tor} via its
14996 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
14997 file-like objects}). See @code{man tor} for details on the configuration file
15000 @item @code{hidden-services} (default: @code{'()})
15001 The list of @code{<hidden-service>} records to use. For any hidden service
15002 you include in this list, appropriate configuration to enable the hidden
15003 service will be automatically added to the default configuration file. You
15004 may conveniently create @code{<hidden-service>} records using the
15005 @code{tor-hidden-service} procedure described below.
15007 @item @code{socks-socket-type} (default: @code{'tcp})
15008 The default socket type that Tor should use for its SOCKS socket. This must
15009 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
15010 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
15011 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
15012 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
15015 If you want to customize the SOCKS socket in more detail, leave
15016 @code{socks-socket-type} at its default value of @code{'tcp} and use
15017 @code{config-file} to override the default by providing your own
15018 @code{SocksPort} option.
15022 @cindex hidden service
15023 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
15024 Define a new Tor @dfn{hidden service} called @var{name} and implementing
15025 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
15028 '((22 "127.0.0.1:22")
15029 (80 "127.0.0.1:8080"))
15032 In this example, port 22 of the hidden service is mapped to local port 22, and
15033 port 80 is mapped to local port 8080.
15035 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
15036 the @file{hostname} file contains the @code{.onion} host name for the hidden
15039 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
15040 project's documentation} for more information.
15043 The @code{(gnu services rsync)} module provides the following services:
15045 You might want an rsync daemon if you have files that you want available
15046 so anyone (or just yourself) can download existing files or upload new
15049 @deffn {Scheme Variable} rsync-service-type
15050 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
15051 The value for this service type is a
15052 @command{rsync-configuration} record as in this example:
15055 (service rsync-service-type)
15058 See below for details about @code{rsync-configuration}.
15061 @deftp {Data Type} rsync-configuration
15062 Data type representing the configuration for @code{rsync-service}.
15065 @item @code{package} (default: @var{rsync})
15066 @code{rsync} package to use.
15068 @item @code{port-number} (default: @code{873})
15069 TCP port on which @command{rsync} listens for incoming connections. If port
15070 is less than @code{1024} @command{rsync} needs to be started as the
15071 @code{root} user and group.
15073 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
15074 Name of the file where @command{rsync} writes its PID.
15076 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
15077 Name of the file where @command{rsync} writes its lock file.
15079 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
15080 Name of the file where @command{rsync} writes its log file.
15082 @item @code{use-chroot?} (default: @var{#t})
15083 Whether to use chroot for @command{rsync} shared directory.
15085 @item @code{share-path} (default: @file{/srv/rsync})
15086 Location of the @command{rsync} shared directory.
15088 @item @code{share-comment} (default: @code{"Rsync share"})
15089 Comment of the @command{rsync} shared directory.
15091 @item @code{read-only?} (default: @var{#f})
15092 Read-write permissions to shared directory.
15094 @item @code{timeout} (default: @code{300})
15095 I/O timeout in seconds.
15097 @item @code{user} (default: @var{"root"})
15098 Owner of the @code{rsync} process.
15100 @item @code{group} (default: @var{"root"})
15101 Group of the @code{rsync} process.
15103 @item @code{uid} (default: @var{"rsyncd"})
15104 User name or user ID that file transfers to and from that module should take
15105 place as when the daemon was run as @code{root}.
15107 @item @code{gid} (default: @var{"rsyncd"})
15108 Group name or group ID that will be used when accessing the module.
15113 Furthermore, @code{(gnu services ssh)} provides the following services.
15117 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
15118 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
15119 [#:allow-empty-passwords? #f] [#:root-login? #f] @
15120 [#:syslog-output? #t] [#:x11-forwarding? #t] @
15121 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
15122 [#:public-key-authentication? #t] [#:initialize? #t]
15123 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
15124 @var{host-key} must designate a file containing the host key, and readable
15127 When @var{daemonic?} is true, @command{lshd} will detach from the
15128 controlling terminal and log its output to syslogd, unless one sets
15129 @var{syslog-output?} to false. Obviously, it also makes lsh-service
15130 depend on existence of syslogd service. When @var{pid-file?} is true,
15131 @command{lshd} writes its PID to the file called @var{pid-file}.
15133 When @var{initialize?} is true, automatically create the seed and host key
15134 upon service activation if they do not exist yet. This may take long and
15135 require interaction.
15137 When @var{initialize?} is false, it is up to the user to initialize the
15138 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
15139 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
15140 basics,,, lsh, LSH Manual}).
15142 When @var{interfaces} is empty, lshd listens for connections on all the
15143 network interfaces; otherwise, @var{interfaces} must be a list of host names
15146 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
15147 passwords, and @var{root-login?} specifies whether to accept log-ins as
15150 The other options should be self-descriptive.
15155 @deffn {Scheme Variable} openssh-service-type
15156 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
15157 shell daemon, @command{sshd}. Its value must be an
15158 @code{openssh-configuration} record as in this example:
15161 (service openssh-service-type
15162 (openssh-configuration
15163 (x11-forwarding? #t)
15164 (permit-root-login 'without-password)
15166 `(("alice" ,(local-file "alice.pub"))
15167 ("bob" ,(local-file "bob.pub"))))))
15170 See below for details about @code{openssh-configuration}.
15172 This service can be extended with extra authorized keys, as in this
15176 (service-extension openssh-service-type
15177 (const `(("charlie"
15178 ,(local-file "charlie.pub")))))
15182 @deftp {Data Type} openssh-configuration
15183 This is the configuration record for OpenSSH's @command{sshd}.
15186 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
15187 Name of the file where @command{sshd} writes its PID.
15189 @item @code{port-number} (default: @code{22})
15190 TCP port on which @command{sshd} listens for incoming connections.
15192 @item @code{permit-root-login} (default: @code{#f})
15193 This field determines whether and when to allow logins as root. If
15194 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
15195 If it's the symbol @code{'without-password}, then root logins are
15196 permitted but not with password-based authentication.
15198 @item @code{allow-empty-passwords?} (default: @code{#f})
15199 When true, users with empty passwords may log in. When false, they may
15202 @item @code{password-authentication?} (default: @code{#t})
15203 When true, users may log in with their password. When false, they have
15204 other authentication methods.
15206 @item @code{public-key-authentication?} (default: @code{#t})
15207 When true, users may log in using public key authentication. When
15208 false, users have to use other authentication method.
15210 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
15211 This is used only by protocol version 2.
15213 @item @code{x11-forwarding?} (default: @code{#f})
15214 When true, forwarding of X11 graphical client connections is
15215 enabled---in other words, @command{ssh} options @option{-X} and
15216 @option{-Y} will work.
15218 @item @code{allow-agent-forwarding?} (default: @code{#t})
15219 Whether to allow agent forwarding.
15221 @item @code{allow-tcp-forwarding?} (default: @code{#t})
15222 Whether to allow TCP forwarding.
15224 @item @code{gateway-ports?} (default: @code{#f})
15225 Whether to allow gateway ports.
15227 @item @code{challenge-response-authentication?} (default: @code{#f})
15228 Specifies whether challenge response authentication is allowed (e.g.@: via
15231 @item @code{use-pam?} (default: @code{#t})
15232 Enables the Pluggable Authentication Module interface. If set to
15233 @code{#t}, this will enable PAM authentication using
15234 @code{challenge-response-authentication?} and
15235 @code{password-authentication?}, in addition to PAM account and session
15236 module processing for all authentication types.
15238 Because PAM challenge response authentication usually serves an
15239 equivalent role to password authentication, you should disable either
15240 @code{challenge-response-authentication?} or
15241 @code{password-authentication?}.
15243 @item @code{print-last-log?} (default: @code{#t})
15244 Specifies whether @command{sshd} should print the date and time of the
15245 last user login when a user logs in interactively.
15247 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
15248 Configures external subsystems (e.g.@: file transfer daemon).
15250 This is a list of two-element lists, each of which containing the
15251 subsystem name and a command (with optional arguments) to execute upon
15254 The command @command{internal-sftp} implements an in-process SFTP
15255 server. Alternatively, one can specify the @command{sftp-server} command:
15257 (service openssh-service-type
15258 (openssh-configuration
15260 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
15263 @item @code{accepted-environment} (default: @code{'()})
15264 List of strings describing which environment variables may be exported.
15266 Each string gets on its own line. See the @code{AcceptEnv} option in
15267 @code{man sshd_config}.
15269 This example allows ssh-clients to export the @env{COLORTERM} variable.
15270 It is set by terminal emulators, which support colors. You can use it in
15271 your shell's resource file to enable colors for the prompt and commands
15272 if this variable is set.
15275 (service openssh-service-type
15276 (openssh-configuration
15277 (accepted-environment '("COLORTERM"))))
15280 @item @code{authorized-keys} (default: @code{'()})
15281 @cindex authorized keys, SSH
15282 @cindex SSH authorized keys
15283 This is the list of authorized keys. Each element of the list is a user
15284 name followed by one or more file-like objects that represent SSH public
15288 (openssh-configuration
15290 `(("rekado" ,(local-file "rekado.pub"))
15291 ("chris" ,(local-file "chris.pub"))
15292 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
15296 registers the specified public keys for user accounts @code{rekado},
15297 @code{chris}, and @code{root}.
15299 Additional authorized keys can be specified @i{via}
15300 @code{service-extension}.
15302 Note that this does @emph{not} interfere with the use of
15303 @file{~/.ssh/authorized_keys}.
15305 @item @code{log-level} (default: @code{'info})
15306 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
15307 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
15308 page for @file{sshd_config} for the full list of level names.
15310 @item @code{extra-content} (default: @code{""})
15311 This field can be used to append arbitrary text to the configuration file. It
15312 is especially useful for elaborate configurations that cannot be expressed
15313 otherwise. This configuration, for example, would generally disable root
15314 logins, but permit them from one specific IP address:
15317 (openssh-configuration
15319 Match Address 192.168.0.1
15320 PermitRootLogin yes"))
15326 @deffn {Scheme Procedure} dropbear-service [@var{config}]
15327 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
15328 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
15331 For example, to specify a Dropbear service listening on port 1234, add
15332 this call to the operating system's @code{services} field:
15335 (dropbear-service (dropbear-configuration
15336 (port-number 1234)))
15340 @deftp {Data Type} dropbear-configuration
15341 This data type represents the configuration of a Dropbear SSH daemon.
15344 @item @code{dropbear} (default: @var{dropbear})
15345 The Dropbear package to use.
15347 @item @code{port-number} (default: 22)
15348 The TCP port where the daemon waits for incoming connections.
15350 @item @code{syslog-output?} (default: @code{#t})
15351 Whether to enable syslog output.
15353 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
15354 File name of the daemon's PID file.
15356 @item @code{root-login?} (default: @code{#f})
15357 Whether to allow @code{root} logins.
15359 @item @code{allow-empty-passwords?} (default: @code{#f})
15360 Whether to allow empty passwords.
15362 @item @code{password-authentication?} (default: @code{#t})
15363 Whether to enable password-based authentication.
15368 @deffn {Scheme Variable} autossh-service-type
15369 This is the type for the @uref{https://www.harding.motd.ca/autossh,
15370 AutoSSH} program that runs a copy of @command{ssh} and monitors it,
15371 restarting it as necessary should it die or stop passing traffic.
15372 AutoSSH can be run manually from the command-line by passing arguments
15373 to the binary @command{autossh} from the package @code{autossh}, but it
15374 can also be run as a Guix service. This latter use case is documented
15377 AutoSSH can be used to forward local traffic to a remote machine using
15378 an SSH tunnel, and it respects the @file{~/.ssh/config} of the user it
15381 For example, to specify a service running autossh as the user
15382 @code{pino} and forwarding all local connections to port @code{8081} to
15383 @code{remote:8081} using an SSH tunnel, add this call to the operating
15384 system's @code{services} field:
15387 (service autossh-service-type
15388 (autossh-configuration
15390 (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
15394 @deftp {Data Type} autossh-configuration
15395 This data type represents the configuration of an AutoSSH service.
15399 @item @code{user} (default @code{"autossh"})
15400 The user as which the AutoSSH service is to be run.
15401 This assumes that the specified user exists.
15403 @item @code{poll} (default @code{600})
15404 Specifies the connection poll time in seconds.
15406 @item @code{first-poll} (default @code{#f})
15407 Specifies how many seconds AutoSSH waits before the first connection
15408 test. After this first test, polling is resumed at the pace defined in
15409 @code{poll}. When set to @code{#f}, the first poll is not treated
15410 specially and will also use the connection poll specified in
15413 @item @code{gate-time} (default @code{30})
15414 Specifies how many seconds an SSH connection must be active before it is
15415 considered successful.
15417 @item @code{log-level} (default @code{1})
15418 The log level, corresponding to the levels used by syslog---so @code{0}
15419 is the most silent while @code{7} is the chattiest.
15421 @item @code{max-start} (default @code{#f})
15422 The maximum number of times SSH may be (re)started before AutoSSH exits.
15423 When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
15425 @item @code{message} (default @code{""})
15426 The message to append to the echo message sent when testing connections.
15428 @item @code{port} (default @code{"0"})
15429 The ports used for monitoring the connection. When set to @code{"0"},
15430 monitoring is disabled. When set to @code{"@var{n}"} where @var{n} is
15431 a positive integer, ports @var{n} and @var{n}+1 are used for
15432 monitoring the connection, such that port @var{n} is the base
15433 monitoring port and @code{n+1} is the echo port. When set to
15434 @code{"@var{n}:@var{m}"} where @var{n} and @var{m} are positive
15435 integers, the ports @var{n} and @var{m} are used for monitoring the
15436 connection, such that port @var{n} is the base monitoring port and
15437 @var{m} is the echo port.
15439 @item @code{ssh-options} (default @code{'()})
15440 The list of command-line arguments to pass to @command{ssh} when it is
15441 run. Options @option{-f} and @option{-M} are reserved for AutoSSH and
15442 may cause undefined behaviour.
15447 @defvr {Scheme Variable} %facebook-host-aliases
15448 This variable contains a string for use in @file{/etc/hosts}
15449 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
15450 line contains a entry that maps a known server name of the Facebook
15451 on-line service---e.g., @code{www.facebook.com}---to the local
15452 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
15454 This variable is typically used in the @code{hosts-file} field of an
15455 @code{operating-system} declaration (@pxref{operating-system Reference,
15456 @file{/etc/hosts}}):
15459 (use-modules (gnu) (guix))
15462 (host-name "mymachine")
15465 ;; Create a /etc/hosts file with aliases for "localhost"
15466 ;; and "mymachine", as well as for Facebook servers.
15467 (plain-file "hosts"
15468 (string-append (local-host-aliases host-name)
15469 %facebook-host-aliases))))
15472 This mechanism can prevent programs running locally, such as Web
15473 browsers, from accessing Facebook.
15476 The @code{(gnu services avahi)} provides the following definition.
15478 @defvr {Scheme Variable} avahi-service-type
15479 This is the service that runs @command{avahi-daemon}, a system-wide
15480 mDNS/DNS-SD responder that allows for service discovery and
15481 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
15482 Its value must be a @code{zero-configuration} record---see below.
15484 This service extends the name service cache daemon (nscd) so that it can
15485 resolve @code{.local} host names using
15486 @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
15487 Service Switch}, for information on host name resolution.
15489 Additionally, add the @var{avahi} package to the system profile so that
15490 commands such as @command{avahi-browse} are directly usable.
15493 @deftp {Data Type} avahi-configuration
15494 Data type representation the configuration for Avahi.
15498 @item @code{host-name} (default: @code{#f})
15499 If different from @code{#f}, use that as the host name to
15500 publish for this machine; otherwise, use the machine's actual host name.
15502 @item @code{publish?} (default: @code{#t})
15503 When true, allow host names and services to be published (broadcast) over the
15506 @item @code{publish-workstation?} (default: @code{#t})
15507 When true, @command{avahi-daemon} publishes the machine's host name and IP
15508 address via mDNS on the local network. To view the host names published on
15509 your local network, you can run:
15512 avahi-browse _workstation._tcp
15515 @item @code{wide-area?} (default: @code{#f})
15516 When true, DNS-SD over unicast DNS is enabled.
15518 @item @code{ipv4?} (default: @code{#t})
15519 @itemx @code{ipv6?} (default: @code{#t})
15520 These fields determine whether to use IPv4/IPv6 sockets.
15522 @item @code{domains-to-browse} (default: @code{'()})
15523 This is a list of domains to browse.
15527 @deffn {Scheme Variable} openvswitch-service-type
15528 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
15529 service, whose value should be an @code{openvswitch-configuration}
15533 @deftp {Data Type} openvswitch-configuration
15534 Data type representing the configuration of Open vSwitch, a multilayer
15535 virtual switch which is designed to enable massive network automation
15536 through programmatic extension.
15539 @item @code{package} (default: @var{openvswitch})
15540 Package object of the Open vSwitch.
15545 @defvr {Scheme Variable} pagekite-service-type
15546 This is the service type for the @uref{https://pagekite.net, PageKite} service,
15547 a tunneling solution for making localhost servers publicly visible, even from
15548 behind restrictive firewalls or NAT without forwarded ports. The value for
15549 this service type is a @code{pagekite-configuration} record.
15551 Here's an example exposing the local HTTP and SSH daemons:
15554 (service pagekite-service-type
15555 (pagekite-configuration
15556 (kites '("http:@@kitename:localhost:80:@@kitesecret"
15557 "raw/22:@@kitename:localhost:22:@@kitesecret"))
15558 (extra-file "/etc/pagekite.rc")))
15562 @deftp {Data Type} pagekite-configuration
15563 Data type representing the configuration of PageKite.
15566 @item @code{package} (default: @var{pagekite})
15567 Package object of PageKite.
15569 @item @code{kitename} (default: @code{#f})
15570 PageKite name for authenticating to the frontend server.
15572 @item @code{kitesecret} (default: @code{#f})
15573 Shared secret for authenticating to the frontend server. You should probably
15574 put this inside @code{extra-file} instead.
15576 @item @code{frontend} (default: @code{#f})
15577 Connect to the named PageKite frontend server instead of the
15578 @uref{https://pagekite.net,,pagekite.net} service.
15580 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
15581 List of service kites to use. Exposes HTTP on port 80 by default. The format
15582 is @code{proto:kitename:host:port:secret}.
15584 @item @code{extra-file} (default: @code{#f})
15585 Extra configuration file to read, which you are expected to create manually.
15586 Use this to add additional options and manage shared secrets out-of-band.
15591 @node Unattended Upgrades
15592 @subsection Unattended Upgrades
15594 @cindex unattended upgrades
15595 @cindex upgrades, unattended
15596 Guix provides a service to perform @emph{unattended upgrades}:
15597 periodically, the system automatically reconfigures itself from the
15598 latest Guix. Guix System has several properties that make unattended
15603 upgrades are transactional (either the upgrade succeeds or it fails, but
15604 you cannot end up with an ``in-between'' system state);
15606 the upgrade log is kept---you can view it with @command{guix system
15607 list-generations}---and you can roll back to any previous generation,
15608 should the upgraded system fail to behave as intended;
15610 channel code is authenticated so you know you can only run genuine code
15611 (@pxref{Channels});
15613 @command{guix system reconfigure} prevents downgrades, which makes it
15614 immune to @dfn{downgrade attacks}.
15617 To set up unattended upgrades, add an instance of
15618 @code{unattended-upgrade-service-type} like the one below to the list of
15619 your operating system services:
15622 (service unattended-upgrade-service-type)
15625 The defaults above set up weekly upgrades: every Sunday at midnight.
15626 You do not need to provide the operating system configuration file: it
15627 uses @file{/run/current-system/configuration.scm}, which ensures it
15628 always uses your latest configuration---@pxref{provenance-service-type},
15629 for more information about this file.
15631 There are several things that can be configured, in particular the
15632 periodicity and services (daemons) to be restarted upon completion.
15633 When the upgrade is successful, the service takes care of deleting
15634 system generations older that some threshold, as per @command{guix
15635 system delete-generations}. See the reference below for details.
15637 To ensure that upgrades are actually happening, you can run
15638 @command{guix system describe}. To investigate upgrade failures, visit
15639 the unattended upgrade log file (see below).
15641 @defvr {Scheme Variable} unattended-upgrade-service-type
15642 This is the service type for unattended upgrades. It sets up an mcron
15643 job (@pxref{Scheduled Job Execution}) that runs @command{guix system
15644 reconfigure} from the latest version of the specified channels.
15646 Its value must be a @code{unattended-upgrade-configuration} record (see
15650 @deftp {Data Type} unattended-upgrade-configuration
15651 This data type represents the configuration of the unattended upgrade
15652 service. The following fields are available:
15655 @item @code{schedule} (default: @code{"30 01 * * 0"})
15656 This is the schedule of upgrades, expressed as a gexp containing an
15657 mcron job schedule (@pxref{Guile Syntax, mcron job specifications,,
15658 mcron, GNU@tie{}mcron}).
15660 @item @code{channels} (default: @code{#~%default-channels})
15661 This gexp specifies the channels to use for the upgrade
15662 (@pxref{Channels}). By default, the tip of the official @code{guix}
15665 @item @code{operating-system-file} (default: @code{"/run/current-system/configuration.scm"})
15666 This field specifies the operating system configuration file to use.
15667 The default is to reuse the config file of the current configuration.
15669 There are cases, though, where referring to
15670 @file{/run/current-system/configuration.scm} is not enough, for instance
15671 because that file refers to extra files (SSH public keys, extra
15672 configuration files, etc.) @i{via} @code{local-file} and similar
15673 constructs. For those cases, we recommend something along these lines:
15676 (unattended-upgrade-configuration
15677 (operating-system-file
15678 (file-append (local-file "." "config-dir" #:recursive? #t)
15682 The effect here is to import all of the current directory into the
15683 store, and to refer to @file{config.scm} within that directory.
15684 Therefore, uses of @code{local-file} within @file{config.scm} will work
15685 as expected. @xref{G-Expressions}, for information about
15686 @code{local-file} and @code{file-append}.
15688 @item @code{services-to-restart} (default: @code{'(mcron)})
15689 This field specifies the Shepherd services to restart when the upgrade
15692 Those services are restarted right away upon completion, as with
15693 @command{herd restart}, which ensures that the latest version is
15694 running---remember that by default @command{guix system reconfigure}
15695 only restarts services that are not currently running, which is
15696 conservative: it minimizes disruption but leaves outdated services
15699 By default, the @code{mcron} service is restarted. This ensures that
15700 the latest version of the unattended upgrade job will be used next time.
15702 @item @code{system-expiration} (default: @code{(* 3 30 24 3600)})
15703 This is the expiration time in seconds for system generations. System
15704 generations older that this amount of time are deleted with
15705 @command{guix system delete-generations} when an upgrade completes.
15708 The unattended upgrade service does not run the garbage collector. You
15709 will probably want to set up your own mcron job to run @command{guix gc}
15713 @item @code{maximum-duration} (default: @code{3600})
15714 Maximum duration in seconds for the upgrade; past that time, the upgrade
15717 This is primarily useful to ensure the upgrade does not end up
15718 rebuilding or re-downloading ``the world''.
15720 @item @code{log-file} (default: @code{"/var/log/unattended-upgrade.log"})
15721 File where unattended upgrades are logged.
15726 @subsection X Window
15729 @cindex X Window System
15730 @cindex login manager
15731 Support for the X Window graphical display system---specifically
15732 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
15733 there is no @code{xorg-service} procedure. Instead, the X server is
15734 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
15737 @cindex GNOME, login manager
15738 GDM of course allows users to log in into window managers and desktop
15739 environments other than GNOME; for those using GNOME, GDM is required for
15740 features such as automatic screen locking.
15742 @cindex window manager
15743 To use X11, you must install at least one @dfn{window manager}---for
15744 example the @code{windowmaker} or @code{openbox} packages---preferably
15745 by adding it to the @code{packages} field of your operating system
15746 definition (@pxref{operating-system Reference, system-wide packages}).
15748 @defvr {Scheme Variable} gdm-service-type
15749 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
15750 Desktop Manager} (GDM), a program that manages graphical display servers and
15751 handles graphical user logins. Its value must be a @code{gdm-configuration}
15754 @cindex session types (X11)
15755 @cindex X11 session types
15756 GDM looks for @dfn{session types} described by the @file{.desktop} files in
15757 @file{/run/current-system/profile/share/xsessions} and allows users to choose
15758 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
15759 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
15760 set of packages automatically makes them available at the log-in screen.
15762 In addition, @file{~/.xsession} files are honored. When available,
15763 @file{~/.xsession} must be an executable that starts a window manager
15764 and/or other X clients.
15767 @deftp {Data Type} gdm-configuration
15769 @item @code{auto-login?} (default: @code{#f})
15770 @itemx @code{default-user} (default: @code{#f})
15771 When @code{auto-login?} is false, GDM presents a log-in screen.
15773 When @code{auto-login?} is true, GDM logs in directly as
15774 @code{default-user}.
15776 @item @code{debug?} (default: @code{#f})
15777 When true, GDM writes debug messages to its log.
15779 @item @code{gnome-shell-assets} (default: ...)
15780 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
15782 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
15783 Configuration of the Xorg graphical server.
15785 @item @code{xsession} (default: @code{(xinitrc)})
15786 Script to run before starting a X session.
15788 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
15789 File name of the @code{dbus-daemon} executable.
15791 @item @code{gdm} (default: @code{gdm})
15792 The GDM package to use.
15796 @defvr {Scheme Variable} slim-service-type
15797 This is the type for the SLiM graphical login manager for X11.
15799 Like GDM, SLiM looks for session types described by @file{.desktop} files and
15800 allows users to choose a session from the log-in screen using @kbd{F1}. It
15801 also honors @file{~/.xsession} files.
15803 Unlike GDM, SLiM does not spawn the user session on a different VT after
15804 logging in, which means that you can only start one graphical session. If you
15805 want to be able to run multiple graphical sessions at the same time you have
15806 to add multiple SLiM services to your system services. The following example
15807 shows how to replace the default GDM service with two SLiM services on tty7
15811 (use-modules (gnu services)
15812 (gnu services desktop)
15813 (gnu services xorg)
15814 (srfi srfi-1)) ;for 'remove'
15818 (services (cons* (service slim-service-type (slim-configuration
15821 (service slim-service-type (slim-configuration
15824 (remove (lambda (service)
15825 (eq? (service-kind service) gdm-service-type))
15826 %desktop-services))))
15831 @deftp {Data Type} slim-configuration
15832 Data type representing the configuration of @code{slim-service-type}.
15835 @item @code{allow-empty-passwords?} (default: @code{#t})
15836 Whether to allow logins with empty passwords.
15838 @item @code{auto-login?} (default: @code{#f})
15839 @itemx @code{default-user} (default: @code{""})
15840 When @code{auto-login?} is false, SLiM presents a log-in screen.
15842 When @code{auto-login?} is true, SLiM logs in directly as
15843 @code{default-user}.
15845 @item @code{theme} (default: @code{%default-slim-theme})
15846 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
15847 The graphical theme to use and its name.
15849 @item @code{auto-login-session} (default: @code{#f})
15850 If true, this must be the name of the executable to start as the default
15851 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
15853 If false, a session described by one of the available @file{.desktop}
15854 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
15858 You must install at least one window manager in the system profile or in
15859 your user profile. Failing to do that, if @code{auto-login-session} is
15860 false, you will be unable to log in.
15863 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
15864 Configuration of the Xorg graphical server.
15866 @item @code{display} (default @code{":0"})
15867 The display on which to start the Xorg graphical server.
15869 @item @code{vt} (default @code{"vt7"})
15870 The VT on which to start the Xorg graphical server.
15872 @item @code{xauth} (default: @code{xauth})
15873 The XAuth package to use.
15875 @item @code{shepherd} (default: @code{shepherd})
15876 The Shepherd package used when invoking @command{halt} and
15879 @item @code{sessreg} (default: @code{sessreg})
15880 The sessreg package used in order to register the session.
15882 @item @code{slim} (default: @code{slim})
15883 The SLiM package to use.
15887 @defvr {Scheme Variable} %default-theme
15888 @defvrx {Scheme Variable} %default-theme-name
15889 The default SLiM theme and its name.
15893 @deftp {Data Type} sddm-configuration
15894 This is the data type representing the SDDM service configuration.
15897 @item @code{display-server} (default: "x11")
15898 Select display server to use for the greeter. Valid values are
15899 @samp{"x11"} or @samp{"wayland"}.
15901 @item @code{numlock} (default: "on")
15902 Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
15904 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
15905 Command to run when halting.
15907 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
15908 Command to run when rebooting.
15910 @item @code{theme} (default "maldives")
15911 Theme to use. Default themes provided by SDDM are @samp{"elarun"},
15912 @samp{"maldives"} or @samp{"maya"}.
15914 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
15915 Directory to look for themes.
15917 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
15918 Directory to look for faces.
15920 @item @code{default-path} (default "/run/current-system/profile/bin")
15921 Default PATH to use.
15923 @item @code{minimum-uid} (default: 1000)
15924 Minimum UID displayed in SDDM and allowed for log-in.
15926 @item @code{maximum-uid} (default: 2000)
15927 Maximum UID to display in SDDM.
15929 @item @code{remember-last-user?} (default #t)
15930 Remember last user.
15932 @item @code{remember-last-session?} (default #t)
15933 Remember last session.
15935 @item @code{hide-users} (default "")
15936 Usernames to hide from SDDM greeter.
15938 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
15939 Users with shells listed will be hidden from the SDDM greeter.
15941 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
15942 Script to run before starting a wayland session.
15944 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
15945 Directory to look for desktop files starting wayland sessions.
15947 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
15948 Configuration of the Xorg graphical server.
15950 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
15953 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
15956 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
15957 Script to run after starting xorg-server.
15959 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
15960 Script to run before stopping xorg-server.
15962 @item @code{xsession-command} (default: @code{xinitrc})
15963 Script to run before starting a X session.
15965 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
15966 Directory to look for desktop files starting X sessions.
15968 @item @code{minimum-vt} (default: 7)
15971 @item @code{auto-login-user} (default "")
15972 User to use for auto-login.
15974 @item @code{auto-login-session} (default "")
15975 Desktop file to use for auto-login.
15977 @item @code{relogin?} (default #f)
15978 Relogin after logout.
15983 @cindex login manager
15985 @defvr {Scheme Variable} sddm-service-type
15986 This is the type of the service to run the
15987 @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
15988 must be a @code{sddm-configuration} record (see below).
15990 Here's an example use:
15993 (service sddm-service-type
15994 (sddm-configuration
15995 (auto-login-user "alice")
15996 (auto-login-session "xfce.desktop")))
16000 @deftp {Data Type} sddm-configuration
16001 This data type represents the configuration of the SDDM login manager.
16002 The available fields are:
16005 @item @code{sddm} (default: @code{sddm})
16006 The SDDM package to use.
16008 @item @code{display-server} (default: @code{"x11"})
16009 This must be either @code{"x11"} or @code{"wayland"}.
16011 @c FIXME: Add more fields.
16013 @item @code{auto-login-user} (default: @code{""})
16014 If non-empty, this is the user account under which to log in
16017 @item @code{auto-login-session} (default: @code{""})
16018 If non-empty, this is the @file{.desktop} file name to use as the
16019 auto-login session.
16023 @cindex Xorg, configuration
16024 @deftp {Data Type} xorg-configuration
16025 This data type represents the configuration of the Xorg graphical display
16026 server. Note that there is no Xorg service; instead, the X server is started
16027 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
16028 of these display managers aggregates an @code{xorg-configuration} record.
16031 @item @code{modules} (default: @code{%default-xorg-modules})
16032 This is a list of @dfn{module packages} loaded by the Xorg
16033 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
16035 @item @code{fonts} (default: @code{%default-xorg-fonts})
16036 This is a list of font directories to add to the server's @dfn{font path}.
16038 @item @code{drivers} (default: @code{'()})
16039 This must be either the empty list, in which case Xorg chooses a graphics
16040 driver automatically, or a list of driver names that will be tried in this
16041 order---e.g., @code{("modesetting" "vesa")}.
16043 @item @code{resolutions} (default: @code{'()})
16044 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
16045 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
16048 @cindex keyboard layout, for Xorg
16049 @cindex keymap, for Xorg
16050 @item @code{keyboard-layout} (default: @code{#f})
16051 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
16052 English (``qwerty'') for a 105-key PC keyboard.
16054 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
16055 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
16056 information on how to specify the keyboard layout.
16058 @item @code{extra-config} (default: @code{'()})
16059 This is a list of strings or objects appended to the configuration file. It
16060 is used to pass extra text to be added verbatim to the configuration file.
16062 @item @code{server} (default: @code{xorg-server})
16063 This is the package providing the Xorg server.
16065 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
16066 This is the list of command-line arguments to pass to the X server. The
16067 default is @code{-nolisten tcp}.
16071 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
16072 [@var{login-manager-service-type}]
16073 Tell the log-in manager (of type @var{login-manager-service-type}) to use
16074 @var{config}, an @code{<xorg-configuration>} record.
16076 Since the Xorg configuration is embedded in the log-in manager's
16077 configuration---e.g., @code{gdm-configuration}---this procedure provides a
16078 shorthand to set the Xorg configuration.
16081 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
16082 Return a @code{startx} script in which the modules, fonts, etc. specified
16083 in @var{config}, are available. The result should be used in place of
16086 Usually the X server is started by a login manager.
16090 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
16091 Add @var{package}, a package for a screen locker or screen saver whose
16092 command is @var{program}, to the set of setuid programs and add a PAM entry
16093 for it. For example:
16096 (screen-locker-service xlockmore "xlock")
16099 makes the good ol' XlockMore usable.
16103 @node Printing Services
16104 @subsection Printing Services
16106 @cindex printer support with CUPS
16107 The @code{(gnu services cups)} module provides a Guix service definition
16108 for the CUPS printing service. To add printer support to a Guix
16109 system, add a @code{cups-service} to the operating system definition:
16111 @deffn {Scheme Variable} cups-service-type
16112 The service type for the CUPS print server. Its value should be a valid
16113 CUPS configuration (see below). To use the default settings, simply
16116 (service cups-service-type)
16120 The CUPS configuration controls the basic things about your CUPS
16121 installation: what interfaces it listens on, what to do if a print job
16122 fails, how much logging to do, and so on. To actually add a printer,
16123 you have to visit the @url{http://localhost:631} URL, or use a tool such
16124 as GNOME's printer configuration services. By default, configuring a
16125 CUPS service will generate a self-signed certificate if needed, for
16126 secure connections to the print server.
16128 Suppose you want to enable the Web interface of CUPS and also add
16129 support for Epson printers @i{via} the @code{escpr} package and for HP
16130 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
16131 like this (you need to use the @code{(gnu packages cups)} module):
16134 (service cups-service-type
16135 (cups-configuration
16136 (web-interface? #t)
16138 (list cups-filters escpr hplip-minimal))))
16141 Note: If you wish to use the Qt5 based GUI which comes with the hplip
16142 package then it is suggested that you install the @code{hplip} package,
16143 either in your OS configuration file or as your user.
16145 The available configuration parameters follow. Each parameter
16146 definition is preceded by its type; for example, @samp{string-list foo}
16147 indicates that the @code{foo} parameter should be specified as a list of
16148 strings. There is also a way to specify the configuration as a string,
16149 if you have an old @code{cupsd.conf} file that you want to port over
16150 from some other system; see the end for more details.
16152 @c The following documentation was initially generated by
16153 @c (generate-documentation) in (gnu services cups). Manually maintained
16154 @c documentation is better, so we shouldn't hesitate to edit below as
16155 @c needed. However if the change you want to make to this documentation
16156 @c can be done in an automated way, it's probably easier to change
16157 @c (generate-documentation) than to make it below and have to deal with
16158 @c the churn as CUPS updates.
16161 Available @code{cups-configuration} fields are:
16163 @deftypevr {@code{cups-configuration} parameter} package cups
16167 @deftypevr {@code{cups-configuration} parameter} package-list extensions
16168 Drivers and other extensions to the CUPS package.
16171 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
16172 Configuration of where to write logs, what directories to use for print
16173 spools, and related privileged configuration parameters.
16175 Available @code{files-configuration} fields are:
16177 @deftypevr {@code{files-configuration} parameter} log-location access-log
16178 Defines the access log filename. Specifying a blank filename disables
16179 access log generation. The value @code{stderr} causes log entries to be
16180 sent to the standard error file when the scheduler is running in the
16181 foreground, or to the system log daemon when run in the background. The
16182 value @code{syslog} causes log entries to be sent to the system log
16183 daemon. The server name may be included in filenames using the string
16184 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
16186 Defaults to @samp{"/var/log/cups/access_log"}.
16189 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
16190 Where CUPS should cache data.
16192 Defaults to @samp{"/var/cache/cups"}.
16195 @deftypevr {@code{files-configuration} parameter} string config-file-perm
16196 Specifies the permissions for all configuration files that the scheduler
16199 Note that the permissions for the printers.conf file are currently
16200 masked to only allow access from the scheduler user (typically root).
16201 This is done because printer device URIs sometimes contain sensitive
16202 authentication information that should not be generally known on the
16203 system. There is no way to disable this security feature.
16205 Defaults to @samp{"0640"}.
16208 @deftypevr {@code{files-configuration} parameter} log-location error-log
16209 Defines the error log filename. Specifying a blank filename disables
16210 error log generation. The value @code{stderr} causes log entries to be
16211 sent to the standard error file when the scheduler is running in the
16212 foreground, or to the system log daemon when run in the background. The
16213 value @code{syslog} causes log entries to be sent to the system log
16214 daemon. The server name may be included in filenames using the string
16215 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
16217 Defaults to @samp{"/var/log/cups/error_log"}.
16220 @deftypevr {@code{files-configuration} parameter} string fatal-errors
16221 Specifies which errors are fatal, causing the scheduler to exit. The
16226 No errors are fatal.
16229 All of the errors below are fatal.
16232 Browsing initialization errors are fatal, for example failed connections
16233 to the DNS-SD daemon.
16236 Configuration file syntax errors are fatal.
16239 Listen or Port errors are fatal, except for IPv6 failures on the
16240 loopback or @code{any} addresses.
16243 Log file creation or write errors are fatal.
16246 Bad startup file permissions are fatal, for example shared TLS
16247 certificate and key files with world-read permissions.
16250 Defaults to @samp{"all -browse"}.
16253 @deftypevr {@code{files-configuration} parameter} boolean file-device?
16254 Specifies whether the file pseudo-device can be used for new printer
16255 queues. The URI @uref{file:///dev/null} is always allowed.
16257 Defaults to @samp{#f}.
16260 @deftypevr {@code{files-configuration} parameter} string group
16261 Specifies the group name or ID that will be used when executing external
16264 Defaults to @samp{"lp"}.
16267 @deftypevr {@code{files-configuration} parameter} string log-file-perm
16268 Specifies the permissions for all log files that the scheduler writes.
16270 Defaults to @samp{"0644"}.
16273 @deftypevr {@code{files-configuration} parameter} log-location page-log
16274 Defines the page log filename. Specifying a blank filename disables
16275 page log generation. The value @code{stderr} causes log entries to be
16276 sent to the standard error file when the scheduler is running in the
16277 foreground, or to the system log daemon when run in the background. The
16278 value @code{syslog} causes log entries to be sent to the system log
16279 daemon. The server name may be included in filenames using the string
16280 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
16282 Defaults to @samp{"/var/log/cups/page_log"}.
16285 @deftypevr {@code{files-configuration} parameter} string remote-root
16286 Specifies the username that is associated with unauthenticated accesses
16287 by clients claiming to be the root user. The default is @code{remroot}.
16289 Defaults to @samp{"remroot"}.
16292 @deftypevr {@code{files-configuration} parameter} file-name request-root
16293 Specifies the directory that contains print jobs and other HTTP request
16296 Defaults to @samp{"/var/spool/cups"}.
16299 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
16300 Specifies the level of security sandboxing that is applied to print
16301 filters, backends, and other child processes of the scheduler; either
16302 @code{relaxed} or @code{strict}. This directive is currently only
16303 used/supported on macOS.
16305 Defaults to @samp{strict}.
16308 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
16309 Specifies the location of TLS certificates and private keys. CUPS will
16310 look for public and private keys in this directory: @file{.crt} files
16311 for PEM-encoded certificates and corresponding @file{.key} files for
16312 PEM-encoded private keys.
16314 Defaults to @samp{"/etc/cups/ssl"}.
16317 @deftypevr {@code{files-configuration} parameter} file-name server-root
16318 Specifies the directory containing the server configuration files.
16320 Defaults to @samp{"/etc/cups"}.
16323 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
16324 Specifies whether the scheduler calls fsync(2) after writing
16325 configuration or state files.
16327 Defaults to @samp{#f}.
16330 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
16331 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
16334 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
16335 Specifies the directory where temporary files are stored.
16337 Defaults to @samp{"/var/spool/cups/tmp"}.
16340 @deftypevr {@code{files-configuration} parameter} string user
16341 Specifies the user name or ID that is used when running external
16344 Defaults to @samp{"lp"}.
16347 @deftypevr {@code{files-configuration} parameter} string set-env
16348 Set the specified environment variable to be passed to child processes.
16350 Defaults to @samp{"variable value"}.
16354 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
16355 Specifies the logging level for the AccessLog file. The @code{config}
16356 level logs when printers and classes are added, deleted, or modified and
16357 when configuration files are accessed or updated. The @code{actions}
16358 level logs when print jobs are submitted, held, released, modified, or
16359 canceled, and any of the conditions for @code{config}. The @code{all}
16360 level logs all requests.
16362 Defaults to @samp{actions}.
16365 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
16366 Specifies whether to purge job history data automatically when it is no
16367 longer required for quotas.
16369 Defaults to @samp{#f}.
16372 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
16373 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
16374 For example, @samp{"_cups" "_print"} will tell network clients that both
16375 CUPS sharing and IPP Everywhere are supported.
16377 Defaults to @samp{"_cups"}.
16380 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
16381 Specifies which protocols to use for local printer sharing.
16383 Defaults to @samp{dnssd}.
16386 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
16387 Specifies whether the CUPS web interface is advertised.
16389 Defaults to @samp{#f}.
16392 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
16393 Specifies whether shared printers are advertised.
16395 Defaults to @samp{#f}.
16398 @deftypevr {@code{cups-configuration} parameter} string classification
16399 Specifies the security classification of the server. Any valid banner
16400 name can be used, including @samp{"classified"}, @samp{"confidential"},
16401 @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
16402 banner can be omitted to disable secure printing functions.
16404 Defaults to @samp{""}.
16407 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
16408 Specifies whether users may override the classification (cover page) of
16409 individual print jobs using the @code{job-sheets} option.
16411 Defaults to @samp{#f}.
16414 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
16415 Specifies the default type of authentication to use.
16417 Defaults to @samp{Basic}.
16420 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
16421 Specifies whether encryption will be used for authenticated requests.
16423 Defaults to @samp{Required}.
16426 @deftypevr {@code{cups-configuration} parameter} string default-language
16427 Specifies the default language to use for text and web content.
16429 Defaults to @samp{"en"}.
16432 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
16433 Specifies the default paper size for new print queues. @samp{"Auto"}
16434 uses a locale-specific default, while @samp{"None"} specifies there is
16435 no default paper size. Specific size names are typically
16436 @samp{"Letter"} or @samp{"A4"}.
16438 Defaults to @samp{"Auto"}.
16441 @deftypevr {@code{cups-configuration} parameter} string default-policy
16442 Specifies the default access policy to use.
16444 Defaults to @samp{"default"}.
16447 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
16448 Specifies whether local printers are shared by default.
16450 Defaults to @samp{#t}.
16453 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
16454 Specifies the delay for updating of configuration and state files, in
16455 seconds. A value of 0 causes the update to happen as soon as possible,
16456 typically within a few milliseconds.
16458 Defaults to @samp{30}.
16461 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
16462 Specifies what to do when an error occurs. Possible values are
16463 @code{abort-job}, which will discard the failed print job;
16464 @code{retry-job}, which will retry the job at a later time;
16465 @code{retry-current-job}, which retries the failed job immediately; and
16466 @code{stop-printer}, which stops the printer.
16468 Defaults to @samp{stop-printer}.
16471 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
16472 Specifies the maximum cost of filters that are run concurrently, which
16473 can be used to minimize disk, memory, and CPU resource problems. A
16474 limit of 0 disables filter limiting. An average print to a
16475 non-PostScript printer needs a filter limit of about 200. A PostScript
16476 printer needs about half that (100). Setting the limit below these
16477 thresholds will effectively limit the scheduler to printing a single job
16480 Defaults to @samp{0}.
16483 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
16484 Specifies the scheduling priority of filters that are run to print a
16485 job. The nice value ranges from 0, the highest priority, to 19, the
16488 Defaults to @samp{0}.
16491 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
16492 Specifies whether to do reverse lookups on connecting clients. The
16493 @code{double} setting causes @code{cupsd} to verify that the hostname
16494 resolved from the address matches one of the addresses returned for that
16495 hostname. Double lookups also prevent clients with unregistered
16496 addresses from connecting to your server. Only set this option to
16497 @code{#t} or @code{double} if absolutely required.
16499 Defaults to @samp{#f}.
16502 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
16503 Specifies the number of seconds to wait before killing the filters and
16504 backend associated with a canceled or held job.
16506 Defaults to @samp{30}.
16509 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
16510 Specifies the interval between retries of jobs in seconds. This is
16511 typically used for fax queues but can also be used with normal print
16512 queues whose error policy is @code{retry-job} or
16513 @code{retry-current-job}.
16515 Defaults to @samp{30}.
16518 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
16519 Specifies the number of retries that are done for jobs. This is
16520 typically used for fax queues but can also be used with normal print
16521 queues whose error policy is @code{retry-job} or
16522 @code{retry-current-job}.
16524 Defaults to @samp{5}.
16527 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
16528 Specifies whether to support HTTP keep-alive connections.
16530 Defaults to @samp{#t}.
16533 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
16534 Specifies how long an idle client connection remains open, in seconds.
16536 Defaults to @samp{30}.
16539 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
16540 Specifies the maximum size of print files, IPP requests, and HTML form
16541 data. A limit of 0 disables the limit check.
16543 Defaults to @samp{0}.
16546 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
16547 Listens on the specified interfaces for connections. Valid values are
16548 of the form @var{address}:@var{port}, where @var{address} is either an
16549 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
16550 indicate all addresses. Values can also be file names of local UNIX
16551 domain sockets. The Listen directive is similar to the Port directive
16552 but allows you to restrict access to specific interfaces or networks.
16555 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
16556 Specifies the number of pending connections that will be allowed. This
16557 normally only affects very busy servers that have reached the MaxClients
16558 limit, but can also be triggered by large numbers of simultaneous
16559 connections. When the limit is reached, the operating system will
16560 refuse additional connections until the scheduler can accept the pending
16563 Defaults to @samp{128}.
16566 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
16567 Specifies a set of additional access controls.
16569 Available @code{location-access-controls} fields are:
16571 @deftypevr {@code{location-access-controls} parameter} file-name path
16572 Specifies the URI path to which the access control applies.
16575 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
16576 Access controls for all access to this path, in the same format as the
16577 @code{access-controls} of @code{operation-access-control}.
16579 Defaults to @samp{()}.
16582 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
16583 Access controls for method-specific access to this path.
16585 Defaults to @samp{()}.
16587 Available @code{method-access-controls} fields are:
16589 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
16590 If @code{#t}, apply access controls to all methods except the listed
16591 methods. Otherwise apply to only the listed methods.
16593 Defaults to @samp{#f}.
16596 @deftypevr {@code{method-access-controls} parameter} method-list methods
16597 Methods to which this access control applies.
16599 Defaults to @samp{()}.
16602 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
16603 Access control directives, as a list of strings. Each string should be
16604 one directive, such as @samp{"Order allow,deny"}.
16606 Defaults to @samp{()}.
16611 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
16612 Specifies the number of debugging messages that are retained for logging
16613 if an error occurs in a print job. Debug messages are logged regardless
16614 of the LogLevel setting.
16616 Defaults to @samp{100}.
16619 @deftypevr {@code{cups-configuration} parameter} log-level log-level
16620 Specifies the level of logging for the ErrorLog file. The value
16621 @code{none} stops all logging while @code{debug2} logs everything.
16623 Defaults to @samp{info}.
16626 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
16627 Specifies the format of the date and time in the log files. The value
16628 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
16630 Defaults to @samp{standard}.
16633 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
16634 Specifies the maximum number of simultaneous clients that are allowed by
16637 Defaults to @samp{100}.
16640 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
16641 Specifies the maximum number of simultaneous clients that are allowed
16642 from a single address.
16644 Defaults to @samp{100}.
16647 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
16648 Specifies the maximum number of copies that a user can print of each
16651 Defaults to @samp{9999}.
16654 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
16655 Specifies the maximum time a job may remain in the @code{indefinite}
16656 hold state before it is canceled. A value of 0 disables cancellation of
16659 Defaults to @samp{0}.
16662 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
16663 Specifies the maximum number of simultaneous jobs that are allowed. Set
16664 to 0 to allow an unlimited number of jobs.
16666 Defaults to @samp{500}.
16669 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
16670 Specifies the maximum number of simultaneous jobs that are allowed per
16671 printer. A value of 0 allows up to MaxJobs jobs per printer.
16673 Defaults to @samp{0}.
16676 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
16677 Specifies the maximum number of simultaneous jobs that are allowed per
16678 user. A value of 0 allows up to MaxJobs jobs per user.
16680 Defaults to @samp{0}.
16683 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
16684 Specifies the maximum time a job may take to print before it is
16685 canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
16687 Defaults to @samp{10800}.
16690 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
16691 Specifies the maximum size of the log files before they are rotated, in
16692 bytes. The value 0 disables log rotation.
16694 Defaults to @samp{1048576}.
16697 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
16698 Specifies the maximum amount of time to allow between files in a
16699 multiple file print job, in seconds.
16701 Defaults to @samp{300}.
16704 @deftypevr {@code{cups-configuration} parameter} string page-log-format
16705 Specifies the format of PageLog lines. Sequences beginning with percent
16706 (@samp{%}) characters are replaced with the corresponding information,
16707 while all other characters are copied literally. The following percent
16708 sequences are recognized:
16712 insert a single percent character
16715 insert the value of the specified IPP attribute
16718 insert the number of copies for the current page
16721 insert the current page number
16724 insert the current date and time in common log format
16730 insert the printer name
16733 insert the username
16736 A value of the empty string disables page logging. The string @code{%p
16737 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
16738 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
16741 Defaults to @samp{""}.
16744 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
16745 Passes the specified environment variable(s) to child processes; a list
16748 Defaults to @samp{()}.
16751 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
16752 Specifies named access control policies.
16754 Available @code{policy-configuration} fields are:
16756 @deftypevr {@code{policy-configuration} parameter} string name
16757 Name of the policy.
16760 @deftypevr {@code{policy-configuration} parameter} string job-private-access
16761 Specifies an access list for a job's private values. @code{@@ACL} maps
16762 to the printer's requesting-user-name-allowed or
16763 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
16764 owner. @code{@@SYSTEM} maps to the groups listed for the
16765 @code{system-group} field of the @code{files-config} configuration,
16766 which is reified into the @code{cups-files.conf(5)} file. Other
16767 possible elements of the access list include specific user names, and
16768 @code{@@@var{group}} to indicate members of a specific group. The
16769 access list may also be simply @code{all} or @code{default}.
16771 Defaults to @samp{"@@OWNER @@SYSTEM"}.
16774 @deftypevr {@code{policy-configuration} parameter} string job-private-values
16775 Specifies the list of job values to make private, or @code{all},
16776 @code{default}, or @code{none}.
16778 Defaults to @samp{"job-name job-originating-host-name
16779 job-originating-user-name phone"}.
16782 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
16783 Specifies an access list for a subscription's private values.
16784 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
16785 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
16786 owner. @code{@@SYSTEM} maps to the groups listed for the
16787 @code{system-group} field of the @code{files-config} configuration,
16788 which is reified into the @code{cups-files.conf(5)} file. Other
16789 possible elements of the access list include specific user names, and
16790 @code{@@@var{group}} to indicate members of a specific group. The
16791 access list may also be simply @code{all} or @code{default}.
16793 Defaults to @samp{"@@OWNER @@SYSTEM"}.
16796 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
16797 Specifies the list of job values to make private, or @code{all},
16798 @code{default}, or @code{none}.
16800 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
16801 notify-subscriber-user-name notify-user-data"}.
16804 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
16805 Access control by IPP operation.
16807 Defaults to @samp{()}.
16811 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
16812 Specifies whether job files (documents) are preserved after a job is
16813 printed. If a numeric value is specified, job files are preserved for
16814 the indicated number of seconds after printing. Otherwise a boolean
16815 value applies indefinitely.
16817 Defaults to @samp{86400}.
16820 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
16821 Specifies whether the job history is preserved after a job is printed.
16822 If a numeric value is specified, the job history is preserved for the
16823 indicated number of seconds after printing. If @code{#t}, the job
16824 history is preserved until the MaxJobs limit is reached.
16826 Defaults to @samp{#t}.
16829 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
16830 Specifies the amount of time to wait for job completion before
16831 restarting the scheduler.
16833 Defaults to @samp{30}.
16836 @deftypevr {@code{cups-configuration} parameter} string rip-cache
16837 Specifies the maximum amount of memory to use when converting documents
16838 into bitmaps for a printer.
16840 Defaults to @samp{"128m"}.
16843 @deftypevr {@code{cups-configuration} parameter} string server-admin
16844 Specifies the email address of the server administrator.
16846 Defaults to @samp{"root@@localhost.localdomain"}.
16849 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
16850 The ServerAlias directive is used for HTTP Host header validation when
16851 clients connect to the scheduler from external interfaces. Using the
16852 special name @code{*} can expose your system to known browser-based DNS
16853 rebinding attacks, even when accessing sites through a firewall. If the
16854 auto-discovery of alternate names does not work, we recommend listing
16855 each alternate name with a ServerAlias directive instead of using
16858 Defaults to @samp{*}.
16861 @deftypevr {@code{cups-configuration} parameter} string server-name
16862 Specifies the fully-qualified host name of the server.
16864 Defaults to @samp{"localhost"}.
16867 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
16868 Specifies what information is included in the Server header of HTTP
16869 responses. @code{None} disables the Server header. @code{ProductOnly}
16870 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
16871 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
16872 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
16873 the output of the @code{uname} command. @code{Full} reports @code{CUPS
16874 2.0.0 (@var{uname}) IPP/2.0}.
16876 Defaults to @samp{Minimal}.
16879 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
16880 Listens on the specified interfaces for encrypted connections. Valid
16881 values are of the form @var{address}:@var{port}, where @var{address} is
16882 either an IPv6 address enclosed in brackets, an IPv4 address, or
16883 @code{*} to indicate all addresses.
16885 Defaults to @samp{()}.
16888 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
16889 Sets encryption options. By default, CUPS only supports encryption
16890 using TLS v1.0 or higher using known secure cipher suites. Security is
16891 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
16892 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
16893 suites, which are required for some older clients. The @code{AllowSSL3} option
16894 enables SSL v3.0, which is required for some older clients that do not support
16895 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
16896 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
16897 protocol version to TLS v1.1.
16899 Defaults to @samp{()}.
16902 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
16903 Specifies whether the scheduler requires clients to strictly adhere to
16904 the IPP specifications.
16906 Defaults to @samp{#f}.
16909 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
16910 Specifies the HTTP request timeout, in seconds.
16912 Defaults to @samp{300}.
16916 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
16917 Specifies whether the web interface is enabled.
16919 Defaults to @samp{#f}.
16922 At this point you're probably thinking ``oh dear, Guix manual, I like
16923 you but you can stop already with the configuration options''. Indeed.
16924 However, one more point: it could be that you have an existing
16925 @code{cupsd.conf} that you want to use. In that case, you can pass an
16926 @code{opaque-cups-configuration} as the configuration of a
16927 @code{cups-service-type}.
16929 Available @code{opaque-cups-configuration} fields are:
16931 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
16935 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
16936 The contents of the @code{cupsd.conf}, as a string.
16939 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
16940 The contents of the @code{cups-files.conf} file, as a string.
16943 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
16944 strings of the same name, you could instantiate a CUPS service like
16948 (service cups-service-type
16949 (opaque-cups-configuration
16950 (cupsd.conf cupsd.conf)
16951 (cups-files.conf cups-files.conf)))
16955 @node Desktop Services
16956 @subsection Desktop Services
16958 The @code{(gnu services desktop)} module provides services that are
16959 usually useful in the context of a ``desktop'' setup---that is, on a
16960 machine running a graphical display server, possibly with graphical user
16961 interfaces, etc. It also defines services that provide specific desktop
16962 environments like GNOME, Xfce or MATE.
16964 To simplify things, the module defines a variable containing the set of
16965 services that users typically expect on a machine with a graphical
16966 environment and networking:
16968 @defvr {Scheme Variable} %desktop-services
16969 This is a list of services that builds upon @code{%base-services} and
16970 adds or adjusts services for a typical ``desktop'' setup.
16972 In particular, it adds a graphical login manager (@pxref{X Window,
16973 @code{gdm-service-type}}), screen lockers, a network management tool
16974 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
16975 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
16976 energy and color management services, the @code{elogind} login and seat
16977 manager, the Polkit privilege service, the GeoClue location service, the
16978 AccountsService daemon that allows authorized users change system passwords,
16979 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
16980 name service switch service configured to be able to use @code{nss-mdns}
16981 (@pxref{Name Service Switch, mDNS}).
16984 The @code{%desktop-services} variable can be used as the @code{services}
16985 field of an @code{operating-system} declaration (@pxref{operating-system
16986 Reference, @code{services}}).
16988 Additionally, the @code{gnome-desktop-service-type},
16989 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
16990 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
16991 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
16992 services like the backlight adjustment helpers and the power management
16993 utilities are added to the system, extending @code{polkit} and @code{dbus}
16994 appropriately, allowing GNOME to operate with elevated privileges on a
16995 limited number of special-purpose system interfaces. Additionally,
16996 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
16997 metapackage to the system profile. Likewise, adding the Xfce service
16998 not only adds the @code{xfce} metapackage to the system profile, but it
16999 also gives the Thunar file manager the ability to open a ``root-mode''
17000 file management window, if the user authenticates using the
17001 administrator's password via the standard polkit graphical interface.
17002 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
17003 appropriately, allowing MATE to operate with elevated privileges on a
17004 limited number of special-purpose system interfaces. Additionally,
17005 adding a service of type @code{mate-desktop-service-type} adds the MATE
17006 metapackage to the system profile. ``Adding Enlightenment'' means that
17007 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
17008 are set as setuid, allowing Enlightenment's screen locker and other
17009 functionality to work as expected.
17011 The desktop environments in Guix use the Xorg display server by
17012 default. If you'd like to use the newer display server protocol
17013 called Wayland, you need to use the @code{sddm-service} instead of
17014 GDM as the graphical login manager. You should then
17015 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
17016 also try starting GNOME on Wayland manually from a TTY with the
17017 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
17018 gnome-session``. Currently only GNOME has support for Wayland.
17020 @defvr {Scheme Variable} gnome-desktop-service-type
17021 This is the type of the service that adds the @uref{https://www.gnome.org,
17022 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
17023 object (see below).
17025 This service adds the @code{gnome} package to the system profile, and extends
17026 polkit with the actions from @code{gnome-settings-daemon}.
17029 @deftp {Data Type} gnome-desktop-configuration
17030 Configuration record for the GNOME desktop environment.
17033 @item @code{gnome} (default: @code{gnome})
17034 The GNOME package to use.
17038 @defvr {Scheme Variable} xfce-desktop-service-type
17039 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
17040 desktop environment. Its value is an @code{xfce-desktop-configuration} object
17043 This service adds the @code{xfce} package to the system profile, and
17044 extends polkit with the ability for @code{thunar} to manipulate the file
17045 system as root from within a user session, after the user has authenticated
17046 with the administrator's password.
17049 @deftp {Data Type} xfce-desktop-configuration
17050 Configuration record for the Xfce desktop environment.
17053 @item @code{xfce} (default: @code{xfce})
17054 The Xfce package to use.
17058 @deffn {Scheme Variable} mate-desktop-service-type
17059 This is the type of the service that runs the @uref{https://mate-desktop.org/,
17060 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
17061 object (see below).
17063 This service adds the @code{mate} package to the system
17064 profile, and extends polkit with the actions from
17065 @code{mate-settings-daemon}.
17068 @deftp {Data Type} mate-desktop-configuration
17069 Configuration record for the MATE desktop environment.
17072 @item @code{mate} (default: @code{mate})
17073 The MATE package to use.
17077 @deffn {Scheme Variable} enlightenment-desktop-service-type
17078 Return a service that adds the @code{enlightenment} package to the system
17079 profile, and extends dbus with actions from @code{efl}.
17082 @deftp {Data Type} enlightenment-desktop-service-configuration
17084 @item @code{enlightenment} (default: @code{enlightenment})
17085 The enlightenment package to use.
17089 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
17090 the default @code{%desktop-services} variable doesn't include any of
17091 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
17092 @code{%desktop-services} in the @code{services} field of your
17093 @code{operating-system}:
17096 (use-modules (gnu))
17097 (use-service-modules desktop)
17100 ;; cons* adds items to the list given as its last argument.
17101 (services (cons* (service gnome-desktop-service-type)
17102 (service xfce-desktop-service)
17103 %desktop-services))
17107 These desktop environments will then be available as options in the
17108 graphical login window.
17110 The actual service definitions included in @code{%desktop-services} and
17111 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
17112 are described below.
17114 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
17115 Return a service that runs the ``system bus'', using @var{dbus}, with
17116 support for @var{services}.
17118 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
17119 facility. Its system bus is used to allow system services to communicate
17120 and to be notified of system-wide events.
17122 @var{services} must be a list of packages that provide an
17123 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
17124 and policy files. For example, to allow avahi-daemon to use the system bus,
17125 @var{services} must be equal to @code{(list avahi)}.
17128 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
17129 Return a service that runs the @code{elogind} login and
17130 seat management daemon. @uref{https://github.com/elogind/elogind,
17131 Elogind} exposes a D-Bus interface that can be used to know which users
17132 are logged in, know what kind of sessions they have open, suspend the
17133 system, inhibit system suspend, reboot the system, and other tasks.
17135 Elogind handles most system-level power events for a computer, for
17136 example suspending the system when a lid is closed, or shutting it down
17137 when the power button is pressed.
17139 The @var{config} keyword argument specifies the configuration for
17140 elogind, and should be the result of an @code{(elogind-configuration
17141 (@var{parameter} @var{value})...)} invocation. Available parameters and
17142 their default values are:
17145 @item kill-user-processes?
17147 @item kill-only-users
17149 @item kill-exclude-users
17151 @item inhibit-delay-max-seconds
17153 @item handle-power-key
17155 @item handle-suspend-key
17157 @item handle-hibernate-key
17159 @item handle-lid-switch
17161 @item handle-lid-switch-docked
17163 @item power-key-ignore-inhibited?
17165 @item suspend-key-ignore-inhibited?
17167 @item hibernate-key-ignore-inhibited?
17169 @item lid-switch-ignore-inhibited?
17171 @item holdoff-timeout-seconds
17175 @item idle-action-seconds
17177 @item runtime-directory-size-percent
17179 @item runtime-directory-size
17183 @item suspend-state
17184 @code{("mem" "standby" "freeze")}
17187 @item hibernate-state
17189 @item hibernate-mode
17190 @code{("platform" "shutdown")}
17191 @item hybrid-sleep-state
17193 @item hybrid-sleep-mode
17194 @code{("suspend" "platform" "shutdown")}
17198 @deffn {Scheme Procedure} accountsservice-service @
17199 [#:accountsservice @var{accountsservice}]
17200 Return a service that runs AccountsService, a system service that can
17201 list available accounts, change their passwords, and so on.
17202 AccountsService integrates with PolicyKit to enable unprivileged users
17203 to acquire the capability to modify their system configuration.
17204 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
17205 accountsservice web site} for more information.
17207 The @var{accountsservice} keyword argument is the @code{accountsservice}
17208 package to expose as a service.
17211 @deffn {Scheme Procedure} polkit-service @
17212 [#:polkit @var{polkit}]
17213 Return a service that runs the
17214 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
17215 management service}, which allows system administrators to grant access to
17216 privileged operations in a structured way. By querying the Polkit service, a
17217 privileged system component can know when it should grant additional
17218 capabilities to ordinary users. For example, an ordinary user can be granted
17219 the capability to suspend the system if the user is logged in locally.
17222 @defvr {Scheme Variable} polkit-wheel-service
17223 Service that adds the @code{wheel} group as admins to the Polkit
17224 service. This makes it so that users in the @code{wheel} group are queried
17225 for their own passwords when performing administrative actions instead of
17226 @code{root}'s, similar to the behaviour used by @code{sudo}.
17229 @defvr {Scheme Variable} upower-service-type
17230 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
17231 system-wide monitor for power consumption and battery levels, with the given
17232 configuration settings.
17234 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
17235 notably used by GNOME.
17238 @deftp {Data Type} upower-configuration
17239 Data type representation the configuration for UPower.
17243 @item @code{upower} (default: @var{upower})
17244 Package to use for @code{upower}.
17246 @item @code{watts-up-pro?} (default: @code{#f})
17247 Enable the Watts Up Pro device.
17249 @item @code{poll-batteries?} (default: @code{#t})
17250 Enable polling the kernel for battery level changes.
17252 @item @code{ignore-lid?} (default: @code{#f})
17253 Ignore the lid state, this can be useful if it's incorrect on a device.
17255 @item @code{use-percentage-for-policy?} (default: @code{#f})
17256 Whether battery percentage based policy should be used. The default is to use
17257 the time left, change to @code{#t} to use the percentage.
17259 @item @code{percentage-low} (default: @code{10})
17260 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
17261 at which the battery is considered low.
17263 @item @code{percentage-critical} (default: @code{3})
17264 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
17265 at which the battery is considered critical.
17267 @item @code{percentage-action} (default: @code{2})
17268 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
17269 at which action will be taken.
17271 @item @code{time-low} (default: @code{1200})
17272 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
17273 seconds at which the battery is considered low.
17275 @item @code{time-critical} (default: @code{300})
17276 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
17277 seconds at which the battery is considered critical.
17279 @item @code{time-action} (default: @code{120})
17280 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
17281 seconds at which action will be taken.
17283 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
17284 The action taken when @code{percentage-action} or @code{time-action} is
17285 reached (depending on the configuration of @code{use-percentage-for-policy?}).
17287 Possible values are:
17297 @code{'hybrid-sleep}.
17303 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
17304 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
17305 UDisks}, a @dfn{disk management} daemon that provides user interfaces
17306 with notifications and ways to mount/unmount disks. Programs that talk
17307 to UDisks include the @command{udisksctl} command, part of UDisks, and
17308 GNOME Disks. Note that Udisks relies on the @command{mount} command, so
17309 it will only be able to use the file-system utilities installed in the
17310 system profile. For example if you want to be able to mount NTFS
17311 file-systems in read and write fashion, you'll need to have
17312 @code{ntfs-3g} installed system-wide.
17315 @deffn {Scheme Variable} colord-service-type
17316 This is the type of the service that runs @command{colord}, a system
17317 service with a D-Bus
17318 interface to manage the color profiles of input and output devices such as
17319 screens and scanners. It is notably used by the GNOME Color Manager graphical
17320 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
17321 site} for more information.
17324 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
17325 Return a configuration allowing an application to access GeoClue
17326 location data. @var{name} is the Desktop ID of the application, without
17327 the @code{.desktop} part. If @var{allowed?} is true, the application
17328 will have access to location information by default. The boolean
17329 @var{system?} value indicates whether an application is a system component
17330 or not. Finally @var{users} is a list of UIDs of all users for which
17331 this application is allowed location info access. An empty users list
17332 means that all users are allowed.
17335 @cindex scanner access
17336 @deffn {Scheme Procedure} sane-service-type
17337 This service provides access to scanners @i{via}
17338 @uref{http://www.sane-project.org, SANE} by installing the necessary udev
17342 @defvr {Scheme Variable} %standard-geoclue-applications
17343 The standard list of well-known GeoClue application configurations,
17344 granting authority to the GNOME date-and-time utility to ask for the
17345 current location in order to set the time zone, and allowing the
17346 IceCat and Epiphany web browsers to request location information.
17347 IceCat and Epiphany both query the user before allowing a web page to
17348 know the user's location.
17351 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
17352 [#:whitelist '()] @
17353 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
17354 [#:submit-data? #f]
17355 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
17356 [#:submission-nick "geoclue"] @
17357 [#:applications %standard-geoclue-applications]
17358 Return a service that runs the GeoClue location service. This service
17359 provides a D-Bus interface to allow applications to request access to a
17360 user's physical location, and optionally to add information to online
17361 location databases. See
17362 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
17363 web site} for more information.
17366 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
17367 [@w{#:auto-enable? #f}]
17368 Return a service that runs the @command{bluetoothd} daemon, which
17369 manages all the Bluetooth devices and provides a number of D-Bus
17370 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
17371 powered automatically at boot, which can be useful when using a
17372 bluetooth keyboard or mouse.
17374 Users need to be in the @code{lp} group to access the D-Bus service.
17377 @defvr {Scheme Variable} gnome-keyring-service-type
17378 This is the type of the service that adds the
17379 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
17380 value is a @code{gnome-keyring-configuration} object (see below).
17382 This service adds the @code{gnome-keyring} package to the system profile
17383 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
17384 a user's login keyring when they log in or setting its password with passwd.
17387 @deftp {Data Type} gnome-keyring-configuration
17388 Configuration record for the GNOME Keyring service.
17391 @item @code{keyring} (default: @code{gnome-keyring})
17392 The GNOME keyring package to use.
17394 @item @code{pam-services}
17395 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
17396 services to extend, where @var{service} is the name of an existing
17397 service to extend and @var{kind} is one of @code{login} or
17400 If @code{login} is given, it adds an optional
17401 @code{pam_gnome_keyring.so} to the auth block without arguments and to
17402 the session block with @code{auto_start}. If @code{passwd} is given, it
17403 adds an optional @code{pam_gnome_keyring.so} to the password block
17406 By default, this field contains ``gdm-password'' with the value @code{login}
17407 and ``passwd'' is with the value @code{passwd}.
17412 @node Sound Services
17413 @subsection Sound Services
17415 @cindex sound support
17417 @cindex PulseAudio, sound support
17419 The @code{(gnu services sound)} module provides a service to configure the
17420 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
17421 preferred ALSA output driver.
17423 @deffn {Scheme Variable} alsa-service-type
17424 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
17425 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
17426 configuration file. The value for this type is a @command{alsa-configuration}
17427 record as in this example:
17430 (service alsa-service-type)
17433 See below for details about @code{alsa-configuration}.
17436 @deftp {Data Type} alsa-configuration
17437 Data type representing the configuration for @code{alsa-service}.
17440 @item @code{alsa-plugins} (default: @var{alsa-plugins})
17441 @code{alsa-plugins} package to use.
17443 @item @code{pulseaudio?} (default: @var{#t})
17444 Whether ALSA applications should transparently be made to use the
17445 @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
17447 Using PulseAudio allows you to run several sound-producing applications
17448 at the same time and to individual control them @i{via}
17449 @command{pavucontrol}, among other things.
17451 @item @code{extra-options} (default: @var{""})
17452 String to append to the @file{/etc/asound.conf} file.
17457 Individual users who want to override the system configuration of ALSA can do
17458 it with the @file{~/.asoundrc} file:
17461 # In guix, we have to specify the absolute path for plugins.
17463 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
17466 # Routing ALSA to jack:
17467 # <http://jackaudio.org/faq/routing_alsa.html>.
17471 0 system:playback_1
17472 1 system:playback_2
17489 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
17492 @deffn {Scheme Variable} pulseaudio-service-type
17493 This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
17494 sound server. It exists to allow system overrides of the default settings
17495 via @code{pulseaudio-configuration}, see below.
17498 This service overrides per-user configuration files. If you want
17499 PulseAudio to honor configuraton files in @file{~/.config/pulse} you
17500 have to unset the environment variables @env{PULSE_CONFIG} and
17501 @env{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
17505 This service on its own does not ensure, that the @code{pulseaudio} package
17506 exists on your machine. It merely adds configuration files for it, as
17507 detailed below. In the (admittedly unlikely) case, that you find yourself
17508 without a @code{pulseaudio} package, consider enabling it through the
17509 @code{alsa-service-type} above.
17513 @deftp {Data Type} pulseaudio-configuration
17514 Data type representing the configuration for @code{pulseaudio-service}.
17517 @item @var{client-conf} (default: @code{'()})
17518 List of settings to set in @file{client.conf}.
17519 Accepts a list of strings or a symbol-value pairs. A string will be
17520 inserted as-is with a newline added. A pair will be formatted as
17521 ``key = value'', again with a newline added.
17523 @item @var{daemon-conf} (default: @code{'((flat-volumes . no))})
17524 List of settings to set in @file{daemon.conf}, formatted just like
17527 @item @var{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
17528 Script file to use as as @file{default.pa}.
17530 @item @var{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
17531 Script file to use as as @file{system.pa}.
17535 @deffn {Scheme Variable} ladspa-service-type
17536 This service sets the @var{LADSPA_PATH} variable, so that programs, which
17537 respect it, e.g. PulseAudio, can load LADSPA plugins.
17539 The following example will setup the service to enable modules from the
17540 @code{swh-plugins} package:
17543 (service ladspa-service-type
17544 (ladspa-configuration (plugins (list swh-plugins))))
17547 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
17552 @node Database Services
17553 @subsection Database Services
17557 The @code{(gnu services databases)} module provides the following services.
17559 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
17560 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
17561 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
17562 Return a service that runs @var{postgresql}, the PostgreSQL database
17565 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
17566 creates a database cluster with @var{locale} as the default
17567 locale, stored in @var{data-directory}. It then listens on @var{port}.
17569 If the services fails to start, it may be due to an incompatible
17570 cluster already present in @var{data-directory}. Adjust it (or, if you
17571 don't need the cluster anymore, delete @var{data-directory}), then
17572 restart the service.
17574 Peer authentication is used by default and the @code{postgres} user
17575 account has no shell, which prevents the direct execution of @code{psql}
17576 commands as this user. To use @code{psql}, you can temporarily log in
17577 as @code{postgres} using a shell, create a PostgreSQL superuser with the
17578 same name as one of the system users and then create the associated
17582 sudo -u postgres -s /bin/sh
17583 createuser --interactive
17584 createdb $MY_USER_LOGIN # Replace appropriately.
17587 @cindex postgresql extension-packages
17588 Additional extensions are loaded from packages listed in
17589 @var{extension-packages}. Extensions are available at runtime. For instance,
17590 to create a geographic database using the @code{postgis} extension, a user can
17591 configure the postgresql-service as in this example:
17595 (use-package-modules databases geo)
17599 ;; postgresql is required to run `psql' but postgis is not required for
17600 ;; proper operation.
17601 (packages (cons* postgresql %base-packages))
17604 (postgresql-service #:extension-packages (list postgis))
17608 Then the extension becomes visible and you can initialise an empty geographic
17609 database in this way:
17613 > create database postgistest;
17614 > \connect postgistest;
17615 > create extension postgis;
17616 > create extension postgis_topology;
17619 There is no need to add this field for contrib extensions such as hstore or
17620 dblink as they are already loadable by postgresql. This field is only
17621 required to add extensions provided by other packages.
17624 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
17625 Return a service that runs @command{mysqld}, the MySQL or MariaDB
17628 The optional @var{config} argument specifies the configuration for
17629 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
17632 @deftp {Data Type} mysql-configuration
17633 Data type representing the configuration of @var{mysql-service}.
17636 @item @code{mysql} (default: @var{mariadb})
17637 Package object of the MySQL database server, can be either @var{mariadb}
17640 For MySQL, a temporary root password will be displayed at activation time.
17641 For MariaDB, the root password is empty.
17643 @item @code{port} (default: @code{3306})
17644 TCP port on which the database server listens for incoming connections.
17648 @defvr {Scheme Variable} memcached-service-type
17649 This is the service type for the @uref{https://memcached.org/,
17650 Memcached} service, which provides a distributed in memory cache. The
17651 value for the service type is a @code{memcached-configuration} object.
17655 (service memcached-service-type)
17658 @deftp {Data Type} memcached-configuration
17659 Data type representing the configuration of memcached.
17662 @item @code{memcached} (default: @code{memcached})
17663 The Memcached package to use.
17665 @item @code{interfaces} (default: @code{'("0.0.0.0")})
17666 Network interfaces on which to listen.
17668 @item @code{tcp-port} (default: @code{11211})
17669 Port on which to accept connections on,
17671 @item @code{udp-port} (default: @code{11211})
17672 Port on which to accept UDP connections on, a value of 0 will disable
17673 listening on a UDP socket.
17675 @item @code{additional-options} (default: @code{'()})
17676 Additional command line options to pass to @code{memcached}.
17680 @defvr {Scheme Variable} mongodb-service-type
17681 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
17682 The value for the service type is a @code{mongodb-configuration} object.
17686 (service mongodb-service-type)
17689 @deftp {Data Type} mongodb-configuration
17690 Data type representing the configuration of mongodb.
17693 @item @code{mongodb} (default: @code{mongodb})
17694 The MongoDB package to use.
17696 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
17697 The configuration file for MongoDB.
17699 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
17700 This value is used to create the directory, so that it exists and is
17701 owned by the mongodb user. It should match the data-directory which
17702 MongoDB is configured to use through the configuration file.
17706 @defvr {Scheme Variable} redis-service-type
17707 This is the service type for the @uref{https://redis.io/, Redis}
17708 key/value store, whose value is a @code{redis-configuration} object.
17711 @deftp {Data Type} redis-configuration
17712 Data type representing the configuration of redis.
17715 @item @code{redis} (default: @code{redis})
17716 The Redis package to use.
17718 @item @code{bind} (default: @code{"127.0.0.1"})
17719 Network interface on which to listen.
17721 @item @code{port} (default: @code{6379})
17722 Port on which to accept connections on, a value of 0 will disable
17723 listening on a TCP socket.
17725 @item @code{working-directory} (default: @code{"/var/lib/redis"})
17726 Directory in which to store the database and related files.
17730 @node Mail Services
17731 @subsection Mail Services
17735 The @code{(gnu services mail)} module provides Guix service definitions
17736 for email services: IMAP, POP3, and LMTP servers, as well as mail
17737 transport agents (MTAs). Lots of acronyms! These services are detailed
17738 in the subsections below.
17740 @subsubheading Dovecot Service
17742 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
17743 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
17746 By default, Dovecot does not need much configuration; the default
17747 configuration object created by @code{(dovecot-configuration)} will
17748 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
17749 certificate will be generated for TLS-protected connections, though
17750 Dovecot will also listen on cleartext ports by default. There are a
17751 number of options, though, which mail administrators might need to change,
17752 and as is the case with other services, Guix allows the system
17753 administrator to specify these parameters via a uniform Scheme interface.
17755 For example, to specify that mail is located at @code{maildir~/.mail},
17756 one would instantiate the Dovecot service like this:
17759 (dovecot-service #:config
17760 (dovecot-configuration
17761 (mail-location "maildir:~/.mail")))
17764 The available configuration parameters follow. Each parameter
17765 definition is preceded by its type; for example, @samp{string-list foo}
17766 indicates that the @code{foo} parameter should be specified as a list of
17767 strings. There is also a way to specify the configuration as a string,
17768 if you have an old @code{dovecot.conf} file that you want to port over
17769 from some other system; see the end for more details.
17771 @c The following documentation was initially generated by
17772 @c (generate-documentation) in (gnu services mail). Manually maintained
17773 @c documentation is better, so we shouldn't hesitate to edit below as
17774 @c needed. However if the change you want to make to this documentation
17775 @c can be done in an automated way, it's probably easier to change
17776 @c (generate-documentation) than to make it below and have to deal with
17777 @c the churn as dovecot updates.
17779 Available @code{dovecot-configuration} fields are:
17781 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
17782 The dovecot package.
17785 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
17786 A list of IPs or hosts where to listen for connections. @samp{*}
17787 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
17788 interfaces. If you want to specify non-default ports or anything more
17789 complex, customize the address and port fields of the
17790 @samp{inet-listener} of the specific services you are interested in.
17793 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
17794 List of protocols we want to serve. Available protocols include
17795 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
17797 Available @code{protocol-configuration} fields are:
17799 @deftypevr {@code{protocol-configuration} parameter} string name
17800 The name of the protocol.
17803 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
17804 UNIX socket path to the master authentication server to find users.
17805 This is used by imap (for shared users) and lda.
17806 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
17809 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
17810 Space separated list of plugins to load.
17813 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
17814 Maximum number of IMAP connections allowed for a user from each IP
17815 address. NOTE: The username is compared case-sensitively.
17816 Defaults to @samp{10}.
17821 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
17822 List of services to enable. Available services include @samp{imap},
17823 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
17826 Available @code{service-configuration} fields are:
17828 @deftypevr {@code{service-configuration} parameter} string kind
17829 The service kind. Valid values include @code{director},
17830 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
17831 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
17832 @code{tcpwrap}, @code{quota-warning}, or anything else.
17835 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
17836 Listeners for the service. A listener is either a
17837 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
17838 an @code{inet-listener-configuration}.
17839 Defaults to @samp{()}.
17841 Available @code{unix-listener-configuration} fields are:
17843 @deftypevr {@code{unix-listener-configuration} parameter} string path
17844 Path to the file, relative to @code{base-dir} field. This is also used as
17848 @deftypevr {@code{unix-listener-configuration} parameter} string mode
17849 The access mode for the socket.
17850 Defaults to @samp{"0600"}.
17853 @deftypevr {@code{unix-listener-configuration} parameter} string user
17854 The user to own the socket.
17855 Defaults to @samp{""}.
17858 @deftypevr {@code{unix-listener-configuration} parameter} string group
17859 The group to own the socket.
17860 Defaults to @samp{""}.
17864 Available @code{fifo-listener-configuration} fields are:
17866 @deftypevr {@code{fifo-listener-configuration} parameter} string path
17867 Path to the file, relative to @code{base-dir} field. This is also used as
17871 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
17872 The access mode for the socket.
17873 Defaults to @samp{"0600"}.
17876 @deftypevr {@code{fifo-listener-configuration} parameter} string user
17877 The user to own the socket.
17878 Defaults to @samp{""}.
17881 @deftypevr {@code{fifo-listener-configuration} parameter} string group
17882 The group to own the socket.
17883 Defaults to @samp{""}.
17887 Available @code{inet-listener-configuration} fields are:
17889 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
17890 The protocol to listen for.
17893 @deftypevr {@code{inet-listener-configuration} parameter} string address
17894 The address on which to listen, or empty for all addresses.
17895 Defaults to @samp{""}.
17898 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
17899 The port on which to listen.
17902 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
17903 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
17905 Defaults to @samp{#t}.
17910 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
17911 Maximum number of simultaneous client connections per process. Once
17912 this number of connections is received, the next incoming connection
17913 will prompt Dovecot to spawn another process. If set to 0,
17914 @code{default-client-limit} is used instead.
17916 Defaults to @samp{0}.
17920 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
17921 Number of connections to handle before starting a new process.
17922 Typically the only useful values are 0 (unlimited) or 1. 1 is more
17923 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
17924 Defaults to @samp{1}.
17928 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
17929 Maximum number of processes that can exist for this service. If set to
17930 0, @code{default-process-limit} is used instead.
17932 Defaults to @samp{0}.
17936 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
17937 Number of processes to always keep waiting for more connections.
17938 Defaults to @samp{0}.
17941 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
17942 If you set @samp{service-count 0}, you probably need to grow
17944 Defaults to @samp{256000000}.
17949 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
17950 Dict configuration, as created by the @code{dict-configuration}
17953 Available @code{dict-configuration} fields are:
17955 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
17956 A list of key-value pairs that this dict should hold.
17957 Defaults to @samp{()}.
17962 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
17963 A list of passdb configurations, each one created by the
17964 @code{passdb-configuration} constructor.
17966 Available @code{passdb-configuration} fields are:
17968 @deftypevr {@code{passdb-configuration} parameter} string driver
17969 The driver that the passdb should use. Valid values include
17970 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
17972 Defaults to @samp{"pam"}.
17975 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
17976 Space separated list of arguments to the passdb driver.
17977 Defaults to @samp{""}.
17982 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
17983 List of userdb configurations, each one created by the
17984 @code{userdb-configuration} constructor.
17986 Available @code{userdb-configuration} fields are:
17988 @deftypevr {@code{userdb-configuration} parameter} string driver
17989 The driver that the userdb should use. Valid values include
17990 @samp{passwd} and @samp{static}.
17991 Defaults to @samp{"passwd"}.
17994 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
17995 Space separated list of arguments to the userdb driver.
17996 Defaults to @samp{""}.
17999 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
18000 Override fields from passwd.
18001 Defaults to @samp{()}.
18006 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
18007 Plug-in configuration, created by the @code{plugin-configuration}
18011 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
18012 List of namespaces. Each item in the list is created by the
18013 @code{namespace-configuration} constructor.
18015 Available @code{namespace-configuration} fields are:
18017 @deftypevr {@code{namespace-configuration} parameter} string name
18018 Name for this namespace.
18021 @deftypevr {@code{namespace-configuration} parameter} string type
18022 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
18023 Defaults to @samp{"private"}.
18026 @deftypevr {@code{namespace-configuration} parameter} string separator
18027 Hierarchy separator to use. You should use the same separator for
18028 all namespaces or some clients get confused. @samp{/} is usually a good
18029 one. The default however depends on the underlying mail storage
18031 Defaults to @samp{""}.
18034 @deftypevr {@code{namespace-configuration} parameter} string prefix
18035 Prefix required to access this namespace. This needs to be
18036 different for all namespaces. For example @samp{Public/}.
18037 Defaults to @samp{""}.
18040 @deftypevr {@code{namespace-configuration} parameter} string location
18041 Physical location of the mailbox. This is in the same format as
18042 mail_location, which is also the default for it.
18043 Defaults to @samp{""}.
18046 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
18047 There can be only one INBOX, and this setting defines which
18049 Defaults to @samp{#f}.
18052 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
18053 If namespace is hidden, it's not advertised to clients via NAMESPACE
18054 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
18055 useful when converting from another server with different namespaces
18056 which you want to deprecate but still keep working. For example you can
18057 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
18059 Defaults to @samp{#f}.
18062 @deftypevr {@code{namespace-configuration} parameter} boolean list?
18063 Show the mailboxes under this namespace with the LIST command. This
18064 makes the namespace visible for clients that do not support the NAMESPACE
18065 extension. The special @code{children} value lists child mailboxes, but
18066 hides the namespace prefix.
18067 Defaults to @samp{#t}.
18070 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
18071 Namespace handles its own subscriptions. If set to @code{#f}, the
18072 parent namespace handles them. The empty prefix should always have this
18074 Defaults to @samp{#t}.
18077 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
18078 List of predefined mailboxes in this namespace.
18079 Defaults to @samp{()}.
18081 Available @code{mailbox-configuration} fields are:
18083 @deftypevr {@code{mailbox-configuration} parameter} string name
18084 Name for this mailbox.
18087 @deftypevr {@code{mailbox-configuration} parameter} string auto
18088 @samp{create} will automatically create this mailbox.
18089 @samp{subscribe} will both create and subscribe to the mailbox.
18090 Defaults to @samp{"no"}.
18093 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
18094 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
18095 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
18096 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
18097 Defaults to @samp{()}.
18104 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
18105 Base directory where to store runtime data.
18106 Defaults to @samp{"/var/run/dovecot/"}.
18109 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
18110 Greeting message for clients.
18111 Defaults to @samp{"Dovecot ready."}.
18114 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
18115 List of trusted network ranges. Connections from these IPs are
18116 allowed to override their IP addresses and ports (for logging and for
18117 authentication checks). @samp{disable-plaintext-auth} is also ignored
18118 for these networks. Typically you would specify your IMAP proxy servers
18120 Defaults to @samp{()}.
18123 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
18124 List of login access check sockets (e.g.@: tcpwrap).
18125 Defaults to @samp{()}.
18128 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
18129 Show more verbose process titles (in ps). Currently shows user name
18130 and IP address. Useful for seeing who is actually using the IMAP
18131 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
18133 Defaults to @samp{#f}.
18136 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
18137 Should all processes be killed when Dovecot master process shuts down.
18138 Setting this to @code{#f} means that Dovecot can be upgraded without
18139 forcing existing client connections to close (although that could also
18140 be a problem if the upgrade is e.g.@: due to a security fix).
18141 Defaults to @samp{#t}.
18144 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
18145 If non-zero, run mail commands via this many connections to doveadm
18146 server, instead of running them directly in the same process.
18147 Defaults to @samp{0}.
18150 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
18151 UNIX socket or host:port used for connecting to doveadm server.
18152 Defaults to @samp{"doveadm-server"}.
18155 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
18156 List of environment variables that are preserved on Dovecot startup
18157 and passed down to all of its child processes. You can also give
18158 key=value pairs to always set specific settings.
18161 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
18162 Disable LOGIN command and all other plaintext authentications unless
18163 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
18164 matches the local IP (i.e.@: you're connecting from the same computer),
18165 the connection is considered secure and plaintext authentication is
18166 allowed. See also ssl=required setting.
18167 Defaults to @samp{#t}.
18170 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
18171 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
18172 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
18173 for caching to be used.
18174 Defaults to @samp{0}.
18177 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
18178 Time to live for cached data. After TTL expires the cached record
18179 is no longer used, *except* if the main database lookup returns internal
18180 failure. We also try to handle password changes automatically: If
18181 user's previous authentication was successful, but this one wasn't, the
18182 cache isn't used. For now this works only with plaintext
18184 Defaults to @samp{"1 hour"}.
18187 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
18188 TTL for negative hits (user not found, password mismatch).
18189 0 disables caching them completely.
18190 Defaults to @samp{"1 hour"}.
18193 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
18194 List of realms for SASL authentication mechanisms that need them.
18195 You can leave it empty if you don't want to support multiple realms.
18196 Many clients simply use the first one listed here, so keep the default
18198 Defaults to @samp{()}.
18201 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
18202 Default realm/domain to use if none was specified. This is used for
18203 both SASL realms and appending @@domain to username in plaintext
18205 Defaults to @samp{""}.
18208 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
18209 List of allowed characters in username. If the user-given username
18210 contains a character not listed in here, the login automatically fails.
18211 This is just an extra check to make sure user can't exploit any
18212 potential quote escaping vulnerabilities with SQL/LDAP databases. If
18213 you want to allow all characters, set this value to empty.
18214 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
18217 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
18218 Username character translations before it's looked up from
18219 databases. The value contains series of from -> to characters. For
18220 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
18221 translated to @samp{@@}.
18222 Defaults to @samp{""}.
18225 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
18226 Username formatting before it's looked up from databases. You can
18227 use the standard variables here, e.g.@: %Lu would lowercase the username,
18228 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
18229 change the @samp{@@} into @samp{-AT-}. This translation is done after
18230 @samp{auth-username-translation} changes.
18231 Defaults to @samp{"%Lu"}.
18234 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
18235 If you want to allow master users to log in by specifying the master
18236 username within the normal username string (i.e.@: not using SASL
18237 mechanism's support for it), you can specify the separator character
18238 here. The format is then <username><separator><master username>.
18239 UW-IMAP uses @samp{*} as the separator, so that could be a good
18241 Defaults to @samp{""}.
18244 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
18245 Username to use for users logging in with ANONYMOUS SASL
18247 Defaults to @samp{"anonymous"}.
18250 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
18251 Maximum number of dovecot-auth worker processes. They're used to
18252 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
18253 They're automatically created and destroyed as needed.
18254 Defaults to @samp{30}.
18257 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
18258 Host name to use in GSSAPI principal names. The default is to use
18259 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
18260 allow all keytab entries.
18261 Defaults to @samp{""}.
18264 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
18265 Kerberos keytab to use for the GSSAPI mechanism. Will use the
18266 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
18267 need to change the auth service to run as root to be able to read this
18269 Defaults to @samp{""}.
18272 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
18273 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
18274 and @samp{ntlm-auth} helper.
18275 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
18276 Defaults to @samp{#f}.
18279 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
18280 Path for Samba's @samp{ntlm-auth} helper binary.
18281 Defaults to @samp{"/usr/bin/ntlm_auth"}.
18284 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
18285 Time to delay before replying to failed authentications.
18286 Defaults to @samp{"2 secs"}.
18289 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
18290 Require a valid SSL client certificate or the authentication
18292 Defaults to @samp{#f}.
18295 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
18296 Take the username from client's SSL certificate, using
18297 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
18299 Defaults to @samp{#f}.
18302 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
18303 List of wanted authentication mechanisms. Supported mechanisms are:
18304 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
18305 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
18306 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
18307 @samp{disable-plaintext-auth} setting.
18310 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
18311 List of IPs or hostnames to all director servers, including ourself.
18312 Ports can be specified as ip:port. The default port is the same as what
18313 director service's @samp{inet-listener} is using.
18314 Defaults to @samp{()}.
18317 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
18318 List of IPs or hostnames to all backend mail servers. Ranges are
18319 allowed too, like 10.0.0.10-10.0.0.30.
18320 Defaults to @samp{()}.
18323 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
18324 How long to redirect users to a specific server after it no longer
18325 has any connections.
18326 Defaults to @samp{"15 min"}.
18329 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
18330 How the username is translated before being hashed. Useful values
18331 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
18332 are shared within domain.
18333 Defaults to @samp{"%Lu"}.
18336 @deftypevr {@code{dovecot-configuration} parameter} string log-path
18337 Log file to use for error messages. @samp{syslog} logs to syslog,
18338 @samp{/dev/stderr} logs to stderr.
18339 Defaults to @samp{"syslog"}.
18342 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
18343 Log file to use for informational messages. Defaults to
18345 Defaults to @samp{""}.
18348 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
18349 Log file to use for debug messages. Defaults to
18350 @samp{info-log-path}.
18351 Defaults to @samp{""}.
18354 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
18355 Syslog facility to use if you're logging to syslog. Usually if you
18356 don't want to use @samp{mail}, you'll use local0..local7. Also other
18357 standard facilities are supported.
18358 Defaults to @samp{"mail"}.
18361 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
18362 Log unsuccessful authentication attempts and the reasons why they
18364 Defaults to @samp{#f}.
18367 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
18368 In case of password mismatches, log the attempted password. Valid
18369 values are no, plain and sha1. sha1 can be useful for detecting brute
18370 force password attempts vs. user simply trying the same password over
18371 and over again. You can also truncate the value to n chars by appending
18372 ":n" (e.g.@: sha1:6).
18373 Defaults to @samp{"no"}.
18376 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
18377 Even more verbose logging for debugging purposes. Shows for example
18379 Defaults to @samp{#f}.
18382 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
18383 In case of password mismatches, log the passwords and used scheme so
18384 the problem can be debugged. Enabling this also enables
18386 Defaults to @samp{#f}.
18389 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
18390 Enable mail process debugging. This can help you figure out why
18391 Dovecot isn't finding your mails.
18392 Defaults to @samp{#f}.
18395 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
18396 Show protocol level SSL errors.
18397 Defaults to @samp{#f}.
18400 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
18401 Prefix for each line written to log file. % codes are in
18402 strftime(3) format.
18403 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
18406 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
18407 List of elements we want to log. The elements which have a
18408 non-empty variable value are joined together to form a comma-separated
18412 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
18413 Login log format. %s contains @samp{login-log-format-elements}
18414 string, %$ contains the data we want to log.
18415 Defaults to @samp{"%$: %s"}.
18418 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
18419 Log prefix for mail processes. See doc/wiki/Variables.txt for list
18420 of possible variables you can use.
18421 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
18424 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
18425 Format to use for logging mail deliveries. You can use variables:
18428 Delivery status message (e.g.@: @samp{saved to INBOX})
18440 Defaults to @samp{"msgid=%m: %$"}.
18443 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
18444 Location for users' mailboxes. The default is empty, which means
18445 that Dovecot tries to find the mailboxes automatically. This won't work
18446 if the user doesn't yet have any mail, so you should explicitly tell
18447 Dovecot the full location.
18449 If you're using mbox, giving a path to the INBOX
18450 file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
18451 where the other mailboxes are kept. This is called the @emph{root mail
18452 directory}, and it must be the first path given in the
18453 @samp{mail-location} setting.
18455 There are a few special variables you can use, e.g.:
18461 user part in user@@domain, same as %u if there's no domain
18463 domain part in user@@domain, empty if there's no domain
18468 See doc/wiki/Variables.txt for full list. Some examples:
18470 @item maildir:~/Maildir
18471 @item mbox:~/mail:INBOX=/var/mail/%u
18472 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
18474 Defaults to @samp{""}.
18477 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
18478 System user and group used to access mails. If you use multiple,
18479 userdb can override these by returning uid or gid fields. You can use
18480 either numbers or names. <doc/wiki/UserIds.txt>.
18481 Defaults to @samp{""}.
18484 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
18486 Defaults to @samp{""}.
18489 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
18490 Group to enable temporarily for privileged operations. Currently
18491 this is used only with INBOX when either its initial creation or
18492 dotlocking fails. Typically this is set to @samp{"mail"} to give access to
18494 Defaults to @samp{""}.
18497 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
18498 Grant access to these supplementary groups for mail processes.
18499 Typically these are used to set up access to shared mailboxes. Note
18500 that it may be dangerous to set these if users can create symlinks
18501 (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
18502 could allow a user to delete others' mailboxes, or @code{ln -s
18503 /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
18507 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
18508 Allow full file system access to clients. There's no access checks
18509 other than what the operating system does for the active UID/GID. It
18510 works with both maildir and mboxes, allowing you to prefix mailboxes
18511 names with e.g.@: @file{/path/} or @file{~user/}.
18512 Defaults to @samp{#f}.
18515 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
18516 Don't use @code{mmap()} at all. This is required if you store indexes to
18517 shared file systems (NFS or clustered file system).
18518 Defaults to @samp{#f}.
18521 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
18522 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
18523 supports @samp{O_EXCL} since version 3, so this should be safe to use
18524 nowadays by default.
18525 Defaults to @samp{#t}.
18528 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
18529 When to use fsync() or fdatasync() calls:
18532 Whenever necessary to avoid losing important data
18534 Useful with e.g.@: NFS when @code{write()}s are delayed
18536 Never use it (best performance, but crashes can lose data).
18538 Defaults to @samp{"optimized"}.
18541 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
18542 Mail storage exists in NFS. Set this to yes to make Dovecot flush
18543 NFS caches whenever needed. If you're using only a single mail server
18545 Defaults to @samp{#f}.
18548 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
18549 Mail index files also exist in NFS. Setting this to yes requires
18550 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
18551 Defaults to @samp{#f}.
18554 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
18555 Locking method for index files. Alternatives are fcntl, flock and
18556 dotlock. Dotlocking uses some tricks which may create more disk I/O
18557 than other locking methods. NFS users: flock doesn't work, remember to
18558 change @samp{mmap-disable}.
18559 Defaults to @samp{"fcntl"}.
18562 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
18563 Directory in which LDA/LMTP temporarily stores incoming mails >128
18565 Defaults to @samp{"/tmp"}.
18568 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
18569 Valid UID range for users. This is mostly to make sure that users can't
18570 log in as daemons or other system users. Note that denying root logins is
18571 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
18573 Defaults to @samp{500}.
18576 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
18578 Defaults to @samp{0}.
18581 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
18582 Valid GID range for users. Users having non-valid GID as primary group ID
18583 aren't allowed to log in. If user belongs to supplementary groups with
18584 non-valid GIDs, those groups are not set.
18585 Defaults to @samp{1}.
18588 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
18590 Defaults to @samp{0}.
18593 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
18594 Maximum allowed length for mail keyword name. It's only forced when
18595 trying to create new keywords.
18596 Defaults to @samp{50}.
18599 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
18600 List of directories under which chrooting is allowed for mail
18601 processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
18602 too). This setting doesn't affect @samp{login-chroot}
18603 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
18604 @samp{/./} in home dirs are ignored. WARNING: Never add directories here
18605 which local users can modify, that may lead to root exploit. Usually
18606 this should be done only if you don't allow shell access for users.
18607 <doc/wiki/Chrooting.txt>.
18608 Defaults to @samp{()}.
18611 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
18612 Default chroot directory for mail processes. This can be overridden
18613 for specific users in user database by giving @samp{/./} in user's home
18614 directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
18615 there is no real need to do chrooting, Dovecot doesn't allow users to
18616 access files outside their mail directory anyway. If your home
18617 directories are prefixed with the chroot directory, append @samp{/.} to
18618 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
18619 Defaults to @samp{""}.
18622 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
18623 UNIX socket path to master authentication server to find users.
18624 This is used by imap (for shared users) and lda.
18625 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
18628 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
18629 Directory where to look up mail plugins.
18630 Defaults to @samp{"/usr/lib/dovecot"}.
18633 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
18634 List of plugins to load for all services. Plugins specific to IMAP,
18635 LDA, etc.@: are added to this list in their own .conf files.
18636 Defaults to @samp{()}.
18639 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
18640 The minimum number of mails in a mailbox before updates are done to
18641 cache file. This allows optimizing Dovecot's behavior to do less disk
18642 writes at the cost of more disk reads.
18643 Defaults to @samp{0}.
18646 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
18647 When IDLE command is running, mailbox is checked once in a while to
18648 see if there are any new mails or other changes. This setting defines
18649 the minimum time to wait between those checks. Dovecot can also use
18650 dnotify, inotify and kqueue to find out immediately when changes
18652 Defaults to @samp{"30 secs"}.
18655 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
18656 Save mails with CR+LF instead of plain LF. This makes sending those
18657 mails take less CPU, especially with sendfile() syscall with Linux and
18658 FreeBSD. But it also creates a bit more disk I/O which may just make it
18659 slower. Also note that if other software reads the mboxes/maildirs,
18660 they may handle the extra CRs wrong and cause problems.
18661 Defaults to @samp{#f}.
18664 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
18665 By default LIST command returns all entries in maildir beginning
18666 with a dot. Enabling this option makes Dovecot return only entries
18667 which are directories. This is done by stat()ing each entry, so it
18668 causes more disk I/O.
18669 (For systems setting struct @samp{dirent->d_type} this check is free
18670 and it's done always regardless of this setting).
18671 Defaults to @samp{#f}.
18674 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
18675 When copying a message, do it with hard links whenever possible.
18676 This makes the performance much better, and it's unlikely to have any
18678 Defaults to @samp{#t}.
18681 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
18682 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
18683 directory only when its mtime changes unexpectedly or when we can't find
18684 the mail otherwise.
18685 Defaults to @samp{#f}.
18688 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
18689 Which locking methods to use for locking mbox. There are four
18694 Create <mailbox>.lock file. This is the oldest and most NFS-safe
18695 solution. If you want to use /var/mail/ like directory, the users will
18696 need write access to that directory.
18698 Same as dotlock, but if it fails because of permissions or because there
18699 isn't enough disk space, just skip it.
18701 Use this if possible. Works with NFS too if lockd is used.
18703 May not exist in all systems. Doesn't work with NFS.
18705 May not exist in all systems. Doesn't work with NFS.
18708 You can use multiple locking methods; if you do the order they're declared
18709 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
18710 locking methods as well. Some operating systems don't allow using some of
18711 them simultaneously.
18714 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
18718 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
18719 Maximum time to wait for lock (all of them) before aborting.
18720 Defaults to @samp{"5 mins"}.
18723 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
18724 If dotlock exists but the mailbox isn't modified in any way,
18725 override the lock file after this much time.
18726 Defaults to @samp{"2 mins"}.
18729 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
18730 When mbox changes unexpectedly we have to fully read it to find out
18731 what changed. If the mbox is large this can take a long time. Since
18732 the change is usually just a newly appended mail, it'd be faster to
18733 simply read the new mails. If this setting is enabled, Dovecot does
18734 this but still safely fallbacks to re-reading the whole mbox file
18735 whenever something in mbox isn't how it's expected to be. The only real
18736 downside to this setting is that if some other MUA changes message
18737 flags, Dovecot doesn't notice it immediately. Note that a full sync is
18738 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
18739 Defaults to @samp{#t}.
18742 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
18743 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
18744 EXAMINE, EXPUNGE or CHECK commands. If this is set,
18745 @samp{mbox-dirty-syncs} is ignored.
18746 Defaults to @samp{#f}.
18749 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
18750 Delay writing mbox headers until doing a full write sync (EXPUNGE
18751 and CHECK commands and when closing the mailbox). This is especially
18752 useful for POP3 where clients often delete all mails. The downside is
18753 that our changes aren't immediately visible to other MUAs.
18754 Defaults to @samp{#t}.
18757 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
18758 If mbox size is smaller than this (e.g.@: 100k), don't write index
18759 files. If an index file already exists it's still read, just not
18761 Defaults to @samp{0}.
18764 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
18765 Maximum dbox file size until it's rotated.
18766 Defaults to @samp{10000000}.
18769 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
18770 Maximum dbox file age until it's rotated. Typically in days. Day
18771 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
18773 Defaults to @samp{"1d"}.
18776 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
18777 When creating new mdbox files, immediately preallocate their size to
18778 @samp{mdbox-rotate-size}. This setting currently works only in Linux
18779 with some file systems (ext4, xfs).
18780 Defaults to @samp{#f}.
18783 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
18784 sdbox and mdbox support saving mail attachments to external files,
18785 which also allows single instance storage for them. Other backends
18786 don't support this for now.
18788 WARNING: This feature hasn't been tested much yet. Use at your own risk.
18790 Directory root where to store mail attachments. Disabled, if empty.
18791 Defaults to @samp{""}.
18794 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
18795 Attachments smaller than this aren't saved externally. It's also
18796 possible to write a plugin to disable saving specific attachments
18798 Defaults to @samp{128000}.
18801 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
18802 File system backend to use for saving attachments:
18805 No SiS done by Dovecot (but this might help FS's own deduplication)
18807 SiS with immediate byte-by-byte comparison during saving
18808 @item sis-queue posix
18809 SiS with delayed comparison and deduplication.
18811 Defaults to @samp{"sis posix"}.
18814 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
18815 Hash format to use in attachment filenames. You can add any text and
18816 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
18817 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
18818 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
18819 Defaults to @samp{"%@{sha1@}"}.
18822 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
18824 Defaults to @samp{100}.
18827 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
18829 Defaults to @samp{1000}.
18832 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
18833 Default VSZ (virtual memory size) limit for service processes.
18834 This is mainly intended to catch and kill processes that leak memory
18835 before they eat up everything.
18836 Defaults to @samp{256000000}.
18839 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
18840 Login user is internally used by login processes. This is the most
18841 untrusted user in Dovecot system. It shouldn't have access to anything
18843 Defaults to @samp{"dovenull"}.
18846 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
18847 Internal user is used by unprivileged processes. It should be
18848 separate from login user, so that login processes can't disturb other
18850 Defaults to @samp{"dovecot"}.
18853 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
18854 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
18855 Defaults to @samp{"required"}.
18858 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
18859 PEM encoded X.509 SSL/TLS certificate (public key).
18860 Defaults to @samp{"</etc/dovecot/default.pem"}.
18863 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
18864 PEM encoded SSL/TLS private key. The key is opened before
18865 dropping root privileges, so keep the key file unreadable by anyone but
18867 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
18870 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
18871 If key file is password protected, give the password here.
18872 Alternatively give it when starting dovecot with -p parameter. Since
18873 this file is often world-readable, you may want to place this setting
18874 instead to a different.
18875 Defaults to @samp{""}.
18878 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
18879 PEM encoded trusted certificate authority. Set this only if you
18880 intend to use @samp{ssl-verify-client-cert? #t}. The file should
18881 contain the CA certificate(s) followed by the matching
18882 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
18883 Defaults to @samp{""}.
18886 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
18887 Require that CRL check succeeds for client certificates.
18888 Defaults to @samp{#t}.
18891 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
18892 Request client to send a certificate. If you also want to require
18893 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
18894 Defaults to @samp{#f}.
18897 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
18898 Which field from certificate to use for username. commonName and
18899 x500UniqueIdentifier are the usual choices. You'll also need to set
18900 @samp{auth-ssl-username-from-cert? #t}.
18901 Defaults to @samp{"commonName"}.
18904 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
18905 Minimum SSL protocol version to accept.
18906 Defaults to @samp{"TLSv1"}.
18909 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
18910 SSL ciphers to use.
18911 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
18914 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
18915 SSL crypto device to use, for valid values run "openssl engine".
18916 Defaults to @samp{""}.
18919 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
18920 Address to use when sending rejection mails.
18921 %d expands to recipient domain.
18922 Defaults to @samp{"postmaster@@%d"}.
18925 @deftypevr {@code{dovecot-configuration} parameter} string hostname
18926 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
18927 and in LMTP replies. Default is the system's real hostname@@domain.
18928 Defaults to @samp{""}.
18931 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
18932 If user is over quota, return with temporary failure instead of
18934 Defaults to @samp{#f}.
18937 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
18938 Binary to use for sending mails.
18939 Defaults to @samp{"/usr/sbin/sendmail"}.
18942 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
18943 If non-empty, send mails via this SMTP host[:port] instead of
18945 Defaults to @samp{""}.
18948 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
18949 Subject: header to use for rejection mails. You can use the same
18950 variables as for @samp{rejection-reason} below.
18951 Defaults to @samp{"Rejected: %s"}.
18954 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
18955 Human readable error message for rejection mails. You can use
18968 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
18971 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
18972 Delimiter character between local-part and detail in email
18974 Defaults to @samp{"+"}.
18977 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
18978 Header where the original recipient address (SMTP's RCPT TO:
18979 address) is taken from if not available elsewhere. With dovecot-lda -a
18980 parameter overrides this. A commonly used header for this is
18982 Defaults to @samp{""}.
18985 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
18986 Should saving a mail to a nonexistent mailbox automatically create
18988 Defaults to @samp{#f}.
18991 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
18992 Should automatically created mailboxes be also automatically
18994 Defaults to @samp{#f}.
18997 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
18998 Maximum IMAP command line length. Some clients generate very long
18999 command lines with huge mailboxes, so you may need to raise this if you
19000 get "Too long argument" or "IMAP command line too large" errors
19002 Defaults to @samp{64000}.
19005 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
19006 IMAP logout format string:
19009 total number of bytes read from client
19011 total number of bytes sent to client.
19013 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
19014 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@}"}.
19017 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
19018 Override the IMAP CAPABILITY response. If the value begins with '+',
19019 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
19020 Defaults to @samp{""}.
19023 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
19024 How long to wait between "OK Still here" notifications when client
19026 Defaults to @samp{"2 mins"}.
19029 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
19030 ID field names and values to send to clients. Using * as the value
19031 makes Dovecot use the default value. The following fields have default
19032 values currently: name, version, os, os-version, support-url,
19034 Defaults to @samp{""}.
19037 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
19038 ID fields sent by client to log. * means everything.
19039 Defaults to @samp{""}.
19042 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
19043 Workarounds for various client bugs:
19046 @item delay-newmail
19047 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
19048 CHECK commands. Some clients ignore them otherwise, for example OSX
19049 Mail (<v2.1). Outlook Express breaks more badly though, without this it
19050 may show user "Message no longer in server" errors. Note that OE6
19051 still breaks even with this workaround if synchronization is set to
19054 @item tb-extra-mailbox-sep
19055 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
19056 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
19057 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
19059 @item tb-lsub-flags
19060 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
19061 This makes Thunderbird realize they aren't selectable and show them
19062 greyed out, instead of only later giving "not selectable" popup error.
19064 Defaults to @samp{()}.
19067 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
19068 Host allowed in URLAUTH URLs sent by client. "*" allows all.
19069 Defaults to @samp{""}.
19073 Whew! Lots of configuration options. The nice thing about it though is
19074 that Guix has a complete interface to Dovecot's configuration
19075 language. This allows not only a nice way to declare configurations,
19076 but also offers reflective capabilities as well: users can write code to
19077 inspect and transform configurations from within Scheme.
19079 However, it could be that you just want to get a @code{dovecot.conf} up
19080 and running. In that case, you can pass an
19081 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
19082 @code{dovecot-service}. As its name indicates, an opaque configuration
19083 does not have easy reflective capabilities.
19085 Available @code{opaque-dovecot-configuration} fields are:
19087 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
19088 The dovecot package.
19091 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
19092 The contents of the @code{dovecot.conf}, as a string.
19095 For example, if your @code{dovecot.conf} is just the empty string, you
19096 could instantiate a dovecot service like this:
19099 (dovecot-service #:config
19100 (opaque-dovecot-configuration
19104 @subsubheading OpenSMTPD Service
19106 @deffn {Scheme Variable} opensmtpd-service-type
19107 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
19108 service, whose value should be an @code{opensmtpd-configuration} object
19109 as in this example:
19112 (service opensmtpd-service-type
19113 (opensmtpd-configuration
19114 (config-file (local-file "./my-smtpd.conf"))))
19118 @deftp {Data Type} opensmtpd-configuration
19119 Data type representing the configuration of opensmtpd.
19122 @item @code{package} (default: @var{opensmtpd})
19123 Package object of the OpenSMTPD SMTP server.
19125 @item @code{config-file} (default: @code{%default-opensmtpd-file})
19126 File-like object of the OpenSMTPD configuration file to use. By default
19127 it listens on the loopback network interface, and allows for mail from
19128 users and daemons on the local machine, as well as permitting email to
19129 remote servers. Run @command{man smtpd.conf} for more information.
19134 @subsubheading Exim Service
19136 @cindex mail transfer agent (MTA)
19137 @cindex MTA (mail transfer agent)
19140 @deffn {Scheme Variable} exim-service-type
19141 This is the type of the @uref{https://exim.org, Exim} mail transfer
19142 agent (MTA), whose value should be an @code{exim-configuration} object
19143 as in this example:
19146 (service exim-service-type
19147 (exim-configuration
19148 (config-file (local-file "./my-exim.conf"))))
19152 In order to use an @code{exim-service-type} service you must also have a
19153 @code{mail-aliases-service-type} service present in your
19154 @code{operating-system} (even if it has no aliases).
19156 @deftp {Data Type} exim-configuration
19157 Data type representing the configuration of exim.
19160 @item @code{package} (default: @var{exim})
19161 Package object of the Exim server.
19163 @item @code{config-file} (default: @code{#f})
19164 File-like object of the Exim configuration file to use. If its value is
19165 @code{#f} then use the default configuration file from the package
19166 provided in @code{package}. The resulting configuration file is loaded
19167 after setting the @code{exim_user} and @code{exim_group} configuration
19173 @subsubheading Getmail service
19178 @deffn {Scheme Variable} getmail-service-type
19179 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
19180 mail retriever, whose value should be an @code{getmail-configuration}.
19183 Available @code{getmail-configuration} fields are:
19185 @deftypevr {@code{getmail-configuration} parameter} symbol name
19186 A symbol to identify the getmail service.
19188 Defaults to @samp{"unset"}.
19192 @deftypevr {@code{getmail-configuration} parameter} package package
19193 The getmail package to use.
19197 @deftypevr {@code{getmail-configuration} parameter} string user
19198 The user to run getmail as.
19200 Defaults to @samp{"getmail"}.
19204 @deftypevr {@code{getmail-configuration} parameter} string group
19205 The group to run getmail as.
19207 Defaults to @samp{"getmail"}.
19211 @deftypevr {@code{getmail-configuration} parameter} string directory
19212 The getmail directory to use.
19214 Defaults to @samp{"/var/lib/getmail/default"}.
19218 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
19219 The getmail configuration file to use.
19221 Available @code{getmail-configuration-file} fields are:
19223 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
19224 What mail account to retrieve mail from, and how to access that account.
19226 Available @code{getmail-retriever-configuration} fields are:
19228 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
19229 The type of mail retriever to use. Valid values include @samp{passwd}
19232 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
19236 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
19237 Username to login to the mail server with.
19239 Defaults to @samp{unset}.
19243 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
19244 Username to login to the mail server with.
19246 Defaults to @samp{unset}.
19250 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
19251 Port number to connect to.
19253 Defaults to @samp{#f}.
19257 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
19258 Override fields from passwd.
19260 Defaults to @samp{""}.
19264 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
19265 Override fields from passwd.
19267 Defaults to @samp{()}.
19271 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
19272 PEM-formatted key file to use for the TLS negotiation.
19274 Defaults to @samp{""}.
19278 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
19279 PEM-formatted certificate file to use for the TLS negotiation.
19281 Defaults to @samp{""}.
19285 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
19286 CA certificates to use.
19288 Defaults to @samp{""}.
19292 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
19293 Extra retriever parameters.
19295 Defaults to @samp{()}.
19301 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
19302 What to do with retrieved messages.
19304 Available @code{getmail-destination-configuration} fields are:
19306 @deftypevr {@code{getmail-destination-configuration} parameter} string type
19307 The type of mail destination. Valid values include @samp{Maildir},
19308 @samp{Mboxrd} and @samp{MDA_external}.
19310 Defaults to @samp{unset}.
19314 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
19315 The path option for the mail destination. The behaviour depends on the
19318 Defaults to @samp{""}.
19322 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
19323 Extra destination parameters
19325 Defaults to @samp{()}.
19331 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
19334 Available @code{getmail-options-configuration} fields are:
19336 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
19337 If set to @samp{0}, getmail will only print warnings and errors. A
19338 value of @samp{1} means that messages will be printed about retrieving
19339 and deleting messages. If set to @samp{2}, getmail will print messages
19340 about each of it's actions.
19342 Defaults to @samp{1}.
19346 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
19347 If true, getmail will retrieve all available messages. Otherwise it
19348 will only retrieve messages it hasn't seen previously.
19350 Defaults to @samp{#t}.
19354 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
19355 If set to true, messages will be deleted from the server after
19356 retrieving and successfully delivering them. Otherwise, messages will
19357 be left on the server.
19359 Defaults to @samp{#f}.
19363 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
19364 Getmail will delete messages this number of days after seeing them, if
19365 they have been delivered. This means messages will be left on the
19366 server this number of days after delivering them. A value of @samp{0}
19367 disabled this feature.
19369 Defaults to @samp{0}.
19373 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
19374 Delete messages larger than this of bytes after retrieving them, even if
19375 the delete and delete-after options are disabled. A value of @samp{0}
19376 disables this feature.
19378 Defaults to @samp{0}.
19382 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
19383 Retrieve messages totalling up to this number of bytes before closing
19384 the session with the server. A value of @samp{0} disables this feature.
19386 Defaults to @samp{0}.
19390 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
19391 Don't retrieve messages larger than this number of bytes. A value of
19392 @samp{0} disables this feature.
19394 Defaults to @samp{0}.
19398 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
19399 If true, getmail will add a Delivered-To header to messages.
19401 Defaults to @samp{#t}.
19405 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
19406 If set, getmail adds a Received header to the messages.
19408 Defaults to @samp{#t}.
19412 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
19413 Getmail will record a log of its actions to the named file. A value of
19414 @samp{""} disables this feature.
19416 Defaults to @samp{""}.
19420 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
19421 If true, getmail will record a log of its actions using the system
19424 Defaults to @samp{#f}.
19428 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
19429 If true, getmail will log information about messages not retrieved and
19430 the reason for not retrieving them, as well as starting and ending
19433 Defaults to @samp{#f}.
19437 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
19438 Extra options to include.
19440 Defaults to @samp{()}.
19448 @deftypevr {@code{getmail-configuration} parameter} list idle
19449 A list of mailboxes that getmail should wait on the server for new mail
19450 notifications. This depends on the server supporting the IDLE
19453 Defaults to @samp{()}.
19457 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
19458 Environment variables to set for getmail.
19460 Defaults to @samp{()}.
19464 @subsubheading Mail Aliases Service
19466 @cindex email aliases
19467 @cindex aliases, for email addresses
19469 @deffn {Scheme Variable} mail-aliases-service-type
19470 This is the type of the service which provides @code{/etc/aliases},
19471 specifying how to deliver mail to users on this system.
19474 (service mail-aliases-service-type
19475 '(("postmaster" "bob")
19476 ("bob" "bob@@example.com" "bob@@example2.com")))
19480 The configuration for a @code{mail-aliases-service-type} service is an
19481 association list denoting how to deliver mail that comes to this
19482 system. Each entry is of the form @code{(alias addresses ...)}, with
19483 @code{alias} specifying the local alias and @code{addresses} specifying
19484 where to deliver this user's mail.
19486 The aliases aren't required to exist as users on the local system. In
19487 the above example, there doesn't need to be a @code{postmaster} entry in
19488 the @code{operating-system}'s @code{user-accounts} in order to deliver
19489 the @code{postmaster} mail to @code{bob} (which subsequently would
19490 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
19492 @subsubheading GNU Mailutils IMAP4 Daemon
19493 @cindex GNU Mailutils IMAP4 Daemon
19495 @deffn {Scheme Variable} imap4d-service-type
19496 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
19497 mailutils, GNU Mailutils Manual}), whose value should be an
19498 @code{imap4d-configuration} object as in this example:
19501 (service imap4d-service-type
19502 (imap4d-configuration
19503 (config-file (local-file "imap4d.conf"))))
19507 @deftp {Data Type} imap4d-configuration
19508 Data type representing the configuration of @command{imap4d}.
19511 @item @code{package} (default: @code{mailutils})
19512 The package that provides @command{imap4d}.
19514 @item @code{config-file} (default: @code{%default-imap4d-config-file})
19515 File-like object of the configuration file to use, by default it will listen
19516 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
19517 Mailutils Manual}, for details.
19522 @node Messaging Services
19523 @subsection Messaging Services
19528 The @code{(gnu services messaging)} module provides Guix service
19529 definitions for messaging services: currently only Prosody is supported.
19531 @subsubheading Prosody Service
19533 @deffn {Scheme Variable} prosody-service-type
19534 This is the type for the @uref{https://prosody.im, Prosody XMPP
19535 communication server}. Its value must be a @code{prosody-configuration}
19536 record as in this example:
19539 (service prosody-service-type
19540 (prosody-configuration
19541 (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
19544 (int-component-configuration
19545 (hostname "conference.example.net")
19547 (mod-muc (mod-muc-configuration)))))
19550 (virtualhost-configuration
19551 (domain "example.net"))))))
19554 See below for details about @code{prosody-configuration}.
19558 By default, Prosody does not need much configuration. Only one
19559 @code{virtualhosts} field is needed: it specifies the domain you wish
19562 You can perform various sanity checks on the generated configuration
19563 with the @code{prosodyctl check} command.
19565 Prosodyctl will also help you to import certificates from the
19566 @code{letsencrypt} directory so that the @code{prosody} user can access
19567 them. See @url{https://prosody.im/doc/letsencrypt}.
19570 prosodyctl --root cert import /etc/letsencrypt/live
19573 The available configuration parameters follow. Each parameter
19574 definition is preceded by its type; for example, @samp{string-list foo}
19575 indicates that the @code{foo} parameter should be specified as a list of
19576 strings. Types starting with @code{maybe-} denote parameters that won't
19577 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
19579 There is also a way to specify the configuration as a string, if you
19580 have an old @code{prosody.cfg.lua} file that you want to port over from
19581 some other system; see the end for more details.
19583 The @code{file-object} type designates either a file-like object
19584 (@pxref{G-Expressions, file-like objects}) or a file name.
19586 @c The following documentation was initially generated by
19587 @c (generate-documentation) in (gnu services messaging). Manually maintained
19588 @c documentation is better, so we shouldn't hesitate to edit below as
19589 @c needed. However if the change you want to make to this documentation
19590 @c can be done in an automated way, it's probably easier to change
19591 @c (generate-documentation) than to make it below and have to deal with
19592 @c the churn as Prosody updates.
19594 Available @code{prosody-configuration} fields are:
19596 @deftypevr {@code{prosody-configuration} parameter} package prosody
19597 The Prosody package.
19600 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
19601 Location of the Prosody data storage directory. See
19602 @url{https://prosody.im/doc/configure}.
19603 Defaults to @samp{"/var/lib/prosody"}.
19606 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
19607 Additional plugin directories. They are searched in all the specified
19608 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
19609 Defaults to @samp{()}.
19612 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
19613 Every virtual host and component needs a certificate so that clients and
19614 servers can securely verify its identity. Prosody will automatically load
19615 certificates/keys from the directory specified here.
19616 Defaults to @samp{"/etc/prosody/certs"}.
19619 @deftypevr {@code{prosody-configuration} parameter} string-list admins
19620 This is a list of accounts that are admins for the server. Note that you
19621 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
19622 @url{https://prosody.im/doc/creating_accounts}.
19623 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
19624 Defaults to @samp{()}.
19627 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
19628 Enable use of libevent for better performance under high load. See
19629 @url{https://prosody.im/doc/libevent}.
19630 Defaults to @samp{#f}.
19633 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
19634 This is the list of modules Prosody will load on startup. It looks for
19635 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
19636 Documentation on modules can be found at:
19637 @url{https://prosody.im/doc/modules}.
19638 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
19641 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
19642 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
19643 should you want to disable them then add them to this list.
19644 Defaults to @samp{()}.
19647 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
19648 Path to a text file where the shared groups are defined. If this path is
19649 empty then @samp{mod_groups} does nothing. See
19650 @url{https://prosody.im/doc/modules/mod_groups}.
19651 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
19654 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
19655 Disable account creation by default, for security. See
19656 @url{https://prosody.im/doc/creating_accounts}.
19657 Defaults to @samp{#f}.
19660 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
19661 These are the SSL/TLS-related settings. Most of them are disabled so to
19662 use Prosody's defaults. If you do not completely understand these options, do
19663 not add them to your config, it is easy to lower the security of your server
19664 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
19666 Available @code{ssl-configuration} fields are:
19668 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
19669 This determines what handshake to use.
19672 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
19673 Path to your private key file.
19676 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
19677 Path to your certificate file.
19680 @deftypevr {@code{ssl-configuration} parameter} file-object capath
19681 Path to directory containing root certificates that you wish Prosody to
19682 trust when verifying the certificates of remote servers.
19683 Defaults to @samp{"/etc/ssl/certs"}.
19686 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
19687 Path to a file containing root certificates that you wish Prosody to trust.
19688 Similar to @code{capath} but with all certificates concatenated together.
19691 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
19692 A list of verification options (these mostly map to OpenSSL's
19693 @code{set_verify()} flags).
19696 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
19697 A list of general options relating to SSL/TLS. These map to OpenSSL's
19698 @code{set_options()}. For a full list of options available in LuaSec, see the
19702 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
19703 How long a chain of certificate authorities to check when looking for a
19704 trusted root certificate.
19707 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
19708 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
19709 clients, and in what order.
19712 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
19713 A path to a file containing parameters for Diffie-Hellman key exchange. You
19714 can create such a file with:
19715 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
19718 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
19719 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
19720 @samp{"secp384r1"}.
19723 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
19724 A list of ``extra'' verification options.
19727 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
19728 Password for encrypted private keys.
19733 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
19734 Whether to force all client-to-server connections to be encrypted or not.
19735 See @url{https://prosody.im/doc/modules/mod_tls}.
19736 Defaults to @samp{#f}.
19739 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
19740 Set of mechanisms that will never be offered. See
19741 @url{https://prosody.im/doc/modules/mod_saslauth}.
19742 Defaults to @samp{("DIGEST-MD5")}.
19745 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
19746 Whether to force all server-to-server connections to be encrypted or not.
19747 See @url{https://prosody.im/doc/modules/mod_tls}.
19748 Defaults to @samp{#f}.
19751 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
19752 Whether to require encryption and certificate authentication. This
19753 provides ideal security, but requires servers you communicate with to support
19754 encryption AND present valid, trusted certificates. See
19755 @url{https://prosody.im/doc/s2s#security}.
19756 Defaults to @samp{#f}.
19759 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
19760 Many servers don't support encryption or have invalid or self-signed
19761 certificates. You can list domains here that will not be required to
19762 authenticate using certificates. They will be authenticated using DNS. See
19763 @url{https://prosody.im/doc/s2s#security}.
19764 Defaults to @samp{()}.
19767 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
19768 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
19769 valid certificates for some domains by specifying a list here. See
19770 @url{https://prosody.im/doc/s2s#security}.
19771 Defaults to @samp{()}.
19774 @deftypevr {@code{prosody-configuration} parameter} string authentication
19775 Select the authentication backend to use. The default provider stores
19776 passwords in plaintext and uses Prosody's configured data storage to store the
19777 authentication data. If you do not trust your server please see
19778 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
19779 about using the hashed backend. See also
19780 @url{https://prosody.im/doc/authentication}
19781 Defaults to @samp{"internal_plain"}.
19784 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
19785 Set logging options. Advanced logging configuration is not yet supported
19786 by the Prosody service. See @url{https://prosody.im/doc/logging}.
19787 Defaults to @samp{"*syslog"}.
19790 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
19791 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
19792 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
19795 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
19796 Maximum allowed size of the HTTP body (in bytes).
19799 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
19800 Some modules expose their own URL in various ways. This URL is built
19801 from the protocol, host and port used. If Prosody sits behind a proxy, the
19802 public URL will be @code{http-external-url} instead. See
19803 @url{https://prosody.im/doc/http#external_url}.
19806 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
19807 A host in Prosody is a domain on which user accounts can be created. For
19808 example if you want your users to have addresses like
19809 @samp{"john.smith@@example.com"} then you need to add a host
19810 @samp{"example.com"}. All options in this list will apply only to this host.
19812 Note: the name @emph{virtual} host is used in configuration to avoid confusion with
19813 the actual physical host that Prosody is installed on. A single Prosody
19814 instance can serve many domains, each one defined as a VirtualHost entry in
19815 Prosody's configuration. Conversely a server that hosts a single domain would
19816 have just one VirtualHost entry.
19818 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
19820 Available @code{virtualhost-configuration} fields are:
19822 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:
19823 @deftypevr {@code{virtualhost-configuration} parameter} string domain
19824 Domain you wish Prosody to serve.
19829 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
19830 Components are extra services on a server which are available to clients,
19831 usually on a subdomain of the main server (such as
19832 @samp{"mycomponent.example.com"}). Example components might be chatroom
19833 servers, user directories, or gateways to other protocols.
19835 Internal components are implemented with Prosody-specific plugins. To add an
19836 internal component, you simply fill the hostname field, and the plugin you wish
19837 to use for the component.
19839 See @url{https://prosody.im/doc/components}.
19840 Defaults to @samp{()}.
19842 Available @code{int-component-configuration} fields are:
19844 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:
19845 @deftypevr {@code{int-component-configuration} parameter} string hostname
19846 Hostname of the component.
19849 @deftypevr {@code{int-component-configuration} parameter} string plugin
19850 Plugin you wish to use for the component.
19853 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
19854 Multi-user chat (MUC) is Prosody's module for allowing you to create
19855 hosted chatrooms/conferences for XMPP users.
19857 General information on setting up and using multi-user chatrooms can be found
19858 in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
19859 which you should read if you are new to XMPP chatrooms.
19861 See also @url{https://prosody.im/doc/modules/mod_muc}.
19863 Available @code{mod-muc-configuration} fields are:
19865 @deftypevr {@code{mod-muc-configuration} parameter} string name
19866 The name to return in service discovery responses.
19867 Defaults to @samp{"Prosody Chatrooms"}.
19870 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
19871 If @samp{#t}, this will only allow admins to create new chatrooms.
19872 Otherwise anyone can create a room. The value @samp{"local"} restricts room
19873 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
19874 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
19875 restricts to service administrators only.
19876 Defaults to @samp{#f}.
19879 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
19880 Maximum number of history messages that will be sent to the member that has
19881 just joined the room.
19882 Defaults to @samp{20}.
19889 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
19890 External components use XEP-0114, which most standalone components
19891 support. To add an external component, you simply fill the hostname field. See
19892 @url{https://prosody.im/doc/components}.
19893 Defaults to @samp{()}.
19895 Available @code{ext-component-configuration} fields are:
19897 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:
19898 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
19899 Password which the component will use to log in.
19902 @deftypevr {@code{ext-component-configuration} parameter} string hostname
19903 Hostname of the component.
19908 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
19909 Port(s) Prosody listens on for component connections.
19910 Defaults to @samp{(5347)}.
19913 @deftypevr {@code{prosody-configuration} parameter} string component-interface
19914 Interface Prosody listens on for component connections.
19915 Defaults to @samp{"127.0.0.1"}.
19918 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
19919 Raw content that will be added to the configuration file.
19922 It could be that you just want to get a @code{prosody.cfg.lua}
19923 up and running. In that case, you can pass an
19924 @code{opaque-prosody-configuration} record as the value of
19925 @code{prosody-service-type}. As its name indicates, an opaque configuration
19926 does not have easy reflective capabilities.
19927 Available @code{opaque-prosody-configuration} fields are:
19929 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
19930 The prosody package.
19933 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
19934 The contents of the @code{prosody.cfg.lua} to use.
19937 For example, if your @code{prosody.cfg.lua} is just the empty
19938 string, you could instantiate a prosody service like this:
19941 (service prosody-service-type
19942 (opaque-prosody-configuration
19943 (prosody.cfg.lua "")))
19946 @c end of Prosody auto-generated documentation
19948 @subsubheading BitlBee Service
19950 @cindex IRC (Internet Relay Chat)
19951 @cindex IRC gateway
19952 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
19953 interface to a variety of messaging protocols such as XMPP.
19955 @defvr {Scheme Variable} bitlbee-service-type
19956 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
19957 gateway daemon. Its value is a @code{bitlbee-configuration} (see
19960 To have BitlBee listen on port 6667 on localhost, add this line to your
19964 (service bitlbee-service-type)
19968 @deftp {Data Type} bitlbee-configuration
19969 This is the configuration for BitlBee, with the following fields:
19972 @item @code{interface} (default: @code{"127.0.0.1"})
19973 @itemx @code{port} (default: @code{6667})
19974 Listen on the network interface corresponding to the IP address
19975 specified in @var{interface}, on @var{port}.
19977 When @var{interface} is @code{127.0.0.1}, only local clients can
19978 connect; when it is @code{0.0.0.0}, connections can come from any
19979 networking interface.
19981 @item @code{bitlbee} (default: @code{bitlbee})
19982 The BitlBee package to use.
19984 @item @code{plugins} (default: @code{'()})
19985 List of plugin packages to use---e.g., @code{bitlbee-discord}.
19987 @item @code{extra-settings} (default: @code{""})
19988 Configuration snippet added as-is to the BitlBee configuration file.
19992 @subsubheading Quassel Service
19994 @cindex IRC (Internet Relay Chat)
19995 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
19996 meaning that one or more clients can attach to and detach from the
19999 @defvr {Scheme Variable} quassel-service-type
20000 This is the service type for the @url{https://quassel-irc.org/,Quassel}
20001 IRC backend daemon. Its value is a @code{quassel-configuration}
20005 @deftp {Data Type} quassel-configuration
20006 This is the configuration for Quassel, with the following fields:
20009 @item @code{quassel} (default: @code{quassel})
20010 The Quassel package to use.
20012 @item @code{interface} (default: @code{"::,0.0.0.0"})
20013 @item @code{port} (default: @code{4242})
20014 Listen on the network interface(s) corresponding to the IPv4 or IPv6
20015 interfaces specified in the comma delimited @var{interface}, on
20018 @item @code{loglevel} (default: @code{"Info"})
20019 The level of logging desired. Accepted values are Debug, Info, Warning
20024 @node Telephony Services
20025 @subsection Telephony Services
20027 @cindex Murmur (VoIP server)
20028 @cindex VoIP server
20029 This section describes how to set up and run a Murmur server. Murmur is
20030 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
20033 @deftp {Data Type} murmur-configuration
20034 The service type for the Murmur server. An example configuration can
20038 (service murmur-service-type
20039 (murmur-configuration
20041 "Welcome to this Mumble server running on Guix!")
20042 (cert-required? #t) ;disallow text password logins
20043 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
20044 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
20047 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
20048 password with the command that is printed during the activation phase.
20050 It is recommended to register a normal Mumble user account
20051 and grant it admin or moderator rights.
20052 You can use the @code{mumble} client to
20053 login as new normal user, register yourself, and log out.
20054 For the next step login with the name @code{SuperUser} use
20055 the @code{SuperUser} password that you set previously,
20056 and grant your newly registered mumble user administrator or moderator
20057 rights and create some channels.
20059 Available @code{murmur-configuration} fields are:
20062 @item @code{package} (default: @code{mumble})
20063 Package that contains @code{bin/murmurd}.
20065 @item @code{user} (default: @code{"murmur"})
20066 User who will run the Murmur server.
20068 @item @code{group} (default: @code{"murmur"})
20069 Group of the user who will run the murmur server.
20071 @item @code{port} (default: @code{64738})
20072 Port on which the server will listen.
20074 @item @code{welcome-text} (default: @code{""})
20075 Welcome text sent to clients when they connect.
20077 @item @code{server-password} (default: @code{""})
20078 Password the clients have to enter in order to connect.
20080 @item @code{max-users} (default: @code{100})
20081 Maximum of users that can be connected to the server at once.
20083 @item @code{max-user-bandwidth} (default: @code{#f})
20084 Maximum voice traffic a user can send per second.
20086 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
20087 File name of the sqlite database.
20088 The service's user will become the owner of the directory.
20090 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
20091 File name of the log file.
20092 The service's user will become the owner of the directory.
20094 @item @code{autoban-attempts} (default: @code{10})
20095 Maximum number of logins a user can make in @code{autoban-timeframe}
20096 without getting auto banned for @code{autoban-time}.
20098 @item @code{autoban-timeframe} (default: @code{120})
20099 Timeframe for autoban in seconds.
20101 @item @code{autoban-time} (default: @code{300})
20102 Amount of time in seconds for which a client gets banned
20103 when violating the autoban limits.
20105 @item @code{opus-threshold} (default: @code{100})
20106 Percentage of clients that need to support opus
20107 before switching over to opus audio codec.
20109 @item @code{channel-nesting-limit} (default: @code{10})
20110 How deep channels can be nested at maximum.
20112 @item @code{channelname-regex} (default: @code{#f})
20113 A string in form of a Qt regular expression that channel names must conform to.
20115 @item @code{username-regex} (default: @code{#f})
20116 A string in form of a Qt regular expression that user names must conform to.
20118 @item @code{text-message-length} (default: @code{5000})
20119 Maximum size in bytes that a user can send in one text chat message.
20121 @item @code{image-message-length} (default: @code{(* 128 1024)})
20122 Maximum size in bytes that a user can send in one image message.
20124 @item @code{cert-required?} (default: @code{#f})
20125 If it is set to @code{#t} clients that use weak password authentication
20126 will not be accepted. Users must have completed the certificate wizard to join.
20128 @item @code{remember-channel?} (default: @code{#f})
20129 Should murmur remember the last channel each user was in when they disconnected
20130 and put them into the remembered channel when they rejoin.
20132 @item @code{allow-html?} (default: @code{#f})
20133 Should html be allowed in text messages, user comments, and channel descriptions.
20135 @item @code{allow-ping?} (default: @code{#f})
20136 Setting to true exposes the current user count, the maximum user count, and
20137 the server's maximum bandwidth per client to unauthenticated users. In the
20138 Mumble client, this information is shown in the Connect dialog.
20140 Disabling this setting will prevent public listing of the server.
20142 @item @code{bonjour?} (default: @code{#f})
20143 Should the server advertise itself in the local network through the bonjour protocol.
20145 @item @code{send-version?} (default: @code{#f})
20146 Should the murmur server version be exposed in ping requests.
20148 @item @code{log-days} (default: @code{31})
20149 Murmur also stores logs in the database, which are accessible via RPC.
20150 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
20151 or -1 to disable logging to the database.
20153 @item @code{obfuscate-ips?} (default: @code{#t})
20154 Should logged ips be obfuscated to protect the privacy of users.
20156 @item @code{ssl-cert} (default: @code{#f})
20157 File name of the SSL/TLS certificate used for encrypted connections.
20160 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
20162 @item @code{ssl-key} (default: @code{#f})
20163 Filepath to the ssl private key used for encrypted connections.
20165 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
20168 @item @code{ssl-dh-params} (default: @code{#f})
20169 File name of a PEM-encoded file with Diffie-Hellman parameters
20170 for the SSL/TLS encryption. Alternatively you set it to
20171 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
20172 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
20174 @item @code{ssl-ciphers} (default: @code{#f})
20175 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
20178 This option is specified using
20179 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
20180 OpenSSL cipher list notation}.
20182 It is recommended that you try your cipher string using 'openssl ciphers <string>'
20183 before setting it here, to get a feel for which cipher suites you will get.
20184 After setting this option, it is recommend that you inspect your Murmur log
20185 to ensure that Murmur is using the cipher suites that you expected it to.
20187 Note: Changing this option may impact the backwards compatibility of your
20188 Murmur server, and can remove the ability for older Mumble clients to be able
20191 @item @code{public-registration} (default: @code{#f})
20192 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
20194 You can optionally register your server in the public server list that the
20195 @code{mumble} client shows on startup.
20196 You cannot register your server if you have set a @code{server-password},
20197 or set @code{allow-ping} to @code{#f}.
20199 It might take a few hours until it shows up in the public list.
20201 @item @code{file} (default: @code{#f})
20202 Optional alternative override for this configuration.
20206 @deftp {Data Type} murmur-public-registration-configuration
20207 Configuration for public registration of a murmur service.
20211 This is a display name for your server. Not to be confused with the hostname.
20213 @item @code{password}
20214 A password to identify your registration.
20215 Subsequent updates will need the same password. Don't lose your password.
20218 This should be a @code{http://} or @code{https://} link to your web
20221 @item @code{hostname} (default: @code{#f})
20222 By default your server will be listed by its IP address.
20223 If it is set your server will be linked by this host name instead.
20229 @node Monitoring Services
20230 @subsection Monitoring Services
20232 @subsubheading Tailon Service
20234 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
20235 viewing and searching log files.
20237 The following example will configure the service with default values.
20238 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
20241 (service tailon-service-type)
20244 The following example customises more of the Tailon configuration,
20245 adding @command{sed} to the list of allowed commands.
20248 (service tailon-service-type
20249 (tailon-configuration
20251 (tailon-configuration-file
20252 (allowed-commands '("tail" "grep" "awk" "sed"))))))
20256 @deftp {Data Type} tailon-configuration
20257 Data type representing the configuration of Tailon.
20258 This type has the following parameters:
20261 @item @code{config-file} (default: @code{(tailon-configuration-file)})
20262 The configuration file to use for Tailon. This can be set to a
20263 @dfn{tailon-configuration-file} record value, or any gexp
20264 (@pxref{G-Expressions}).
20266 For example, to instead use a local file, the @code{local-file} function
20270 (service tailon-service-type
20271 (tailon-configuration
20272 (config-file (local-file "./my-tailon.conf"))))
20275 @item @code{package} (default: @code{tailon})
20276 The tailon package to use.
20281 @deftp {Data Type} tailon-configuration-file
20282 Data type representing the configuration options for Tailon.
20283 This type has the following parameters:
20286 @item @code{files} (default: @code{(list "/var/log")})
20287 List of files to display. The list can include strings for a single file
20288 or directory, or a list, where the first item is the name of a
20289 subsection, and the remaining items are the files or directories in that
20292 @item @code{bind} (default: @code{"localhost:8080"})
20293 Address and port to which Tailon should bind on.
20295 @item @code{relative-root} (default: @code{#f})
20296 URL path to use for Tailon, set to @code{#f} to not use a path.
20298 @item @code{allow-transfers?} (default: @code{#t})
20299 Allow downloading the log files in the web interface.
20301 @item @code{follow-names?} (default: @code{#t})
20302 Allow tailing of not-yet existent files.
20304 @item @code{tail-lines} (default: @code{200})
20305 Number of lines to read initially from each file.
20307 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
20308 Commands to allow running. By default, @code{sed} is disabled.
20310 @item @code{debug?} (default: @code{#f})
20311 Set @code{debug?} to @code{#t} to show debug messages.
20313 @item @code{wrap-lines} (default: @code{#t})
20314 Initial line wrapping state in the web interface. Set to @code{#t} to
20315 initially wrap lines (the default), or to @code{#f} to initially not
20318 @item @code{http-auth} (default: @code{#f})
20319 HTTP authentication type to use. Set to @code{#f} to disable
20320 authentication (the default). Supported values are @code{"digest"} or
20323 @item @code{users} (default: @code{#f})
20324 If HTTP authentication is enabled (see @code{http-auth}), access will be
20325 restricted to the credentials provided here. To configure users, use a
20326 list of pairs, where the first element of the pair is the username, and
20327 the 2nd element of the pair is the password.
20330 (tailon-configuration-file
20331 (http-auth "basic")
20332 (users '(("user1" . "password1")
20333 ("user2" . "password2"))))
20340 @subsubheading Darkstat Service
20342 Darkstat is a packet sniffer that captures network traffic, calculates
20343 statistics about usage, and serves reports over HTTP.
20345 @defvar {Scheme Variable} darkstat-service-type
20346 This is the service type for the
20347 @uref{https://unix4lyfe.org/darkstat/, darkstat}
20348 service, its value must be a @code{darkstat-configuration} record as in
20352 (service darkstat-service-type
20353 (darkstat-configuration
20354 (interface "eno1")))
20358 @deftp {Data Type} darkstat-configuration
20359 Data type representing the configuration of @command{darkstat}.
20362 @item @code{package} (default: @code{darkstat})
20363 The darkstat package to use.
20365 @item @code{interface}
20366 Capture traffic on the specified network interface.
20368 @item @code{port} (default: @code{"667"})
20369 Bind the web interface to the specified port.
20371 @item @code{bind-address} (default: @code{"127.0.0.1"})
20372 Bind the web interface to the specified address.
20374 @item @code{base} (default: @code{"/"})
20375 Specify the path of the base URL. This can be useful if
20376 @command{darkstat} is accessed via a reverse proxy.
20381 @subsubheading Prometheus Node Exporter Service
20383 @cindex prometheus-node-exporter
20384 The Prometheus ``node exporter'' makes hardware and operating system statistics
20385 provided by the Linux kernel available for the Prometheus monitoring system.
20386 This service should be deployed on all physical nodes and virtual machines,
20387 where monitoring these statistics is desirable.
20389 @defvar {Scheme variable} prometheus-node-exporter-service-type
20390 This is the service type for the
20391 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
20392 service, its value must be a @code{prometheus-node-exporter-configuration}
20393 record as in this example:
20396 (service prometheus-node-exporter-service-type
20397 (prometheus-node-exporter-configuration
20398 (web-listen-address ":9100")))
20402 @deftp {Data Type} prometheus-node-exporter-configuration
20403 Data type representing the configuration of @command{node_exporter}.
20406 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
20407 The prometheus-node-exporter package to use.
20409 @item @code{web-listen-address} (default: @code{":9100"})
20410 Bind the web interface to the specified address.
20415 @subsubheading Zabbix server
20416 @cindex zabbix zabbix-server
20417 Zabbix provides monitoring metrics, among others network utilization, CPU load
20418 and disk space consumption:
20421 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
20422 @item Auto-discovery of servers and network devices and interfaces.
20423 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
20424 @item Distributed monitoring with centralized web administration.
20425 @item Native high performance agents.
20426 @item SLA, and ITIL KPI metrics on reporting.
20427 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
20428 @item Remote command execution through Zabbix proxies.
20431 @c %start of fragment
20433 Available @code{zabbix-server-configuration} fields are:
20435 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
20436 The zabbix-server package.
20440 @deftypevr {@code{zabbix-server-configuration} parameter} string user
20441 User who will run the Zabbix server.
20443 Defaults to @samp{"zabbix"}.
20447 @deftypevr {@code{zabbix-server-configuration} parameter} group group
20448 Group who will run the Zabbix server.
20450 Defaults to @samp{"zabbix"}.
20454 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
20455 Database host name.
20457 Defaults to @samp{"127.0.0.1"}.
20461 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
20464 Defaults to @samp{"zabbix"}.
20468 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
20471 Defaults to @samp{"zabbix"}.
20475 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
20476 Database password. Please, use @code{include-files} with
20477 @code{DBPassword=SECRET} inside a specified file instead.
20479 Defaults to @samp{""}.
20483 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
20486 Defaults to @samp{5432}.
20490 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
20491 Specifies where log messages are written to:
20495 @code{system} - syslog.
20498 @code{file} - file specified with @code{log-file} parameter.
20501 @code{console} - standard output.
20505 Defaults to @samp{""}.
20509 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
20510 Log file name for @code{log-type} @code{file} parameter.
20512 Defaults to @samp{"/var/log/zabbix/server.log"}.
20516 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
20519 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
20523 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
20524 The location of certificate authority (CA) files for SSL server
20525 certificate verification.
20527 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
20531 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
20532 Location of SSL client certificates.
20534 Defaults to @samp{"/etc/ssl/certs"}.
20538 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
20539 Extra options will be appended to Zabbix server configuration file.
20541 Defaults to @samp{""}.
20545 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
20546 You may include individual files or all files in a directory in the
20547 configuration file.
20549 Defaults to @samp{()}.
20553 @c %end of fragment
20555 @subsubheading Zabbix agent
20556 @cindex zabbix zabbix-agent
20558 Zabbix agent gathers information for Zabbix server.
20560 @c %start of fragment
20562 Available @code{zabbix-agent-configuration} fields are:
20564 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
20565 The zabbix-agent package.
20569 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
20570 User who will run the Zabbix agent.
20572 Defaults to @samp{"zabbix"}.
20576 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
20577 Group who will run the Zabbix agent.
20579 Defaults to @samp{"zabbix"}.
20583 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
20584 Unique, case sensitive hostname which is required for active checks and
20585 must match hostname as configured on the server.
20587 Defaults to @samp{"Zabbix server"}.
20591 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
20592 Specifies where log messages are written to:
20596 @code{system} - syslog.
20599 @code{file} - file specified with @code{log-file} parameter.
20602 @code{console} - standard output.
20606 Defaults to @samp{""}.
20610 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
20611 Log file name for @code{log-type} @code{file} parameter.
20613 Defaults to @samp{"/var/log/zabbix/agent.log"}.
20617 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
20620 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
20624 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
20625 List of IP addresses, optionally in CIDR notation, or hostnames of
20626 Zabbix servers and Zabbix proxies. Incoming connections will be
20627 accepted only from the hosts listed here.
20629 Defaults to @samp{("127.0.0.1")}.
20633 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
20634 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
20635 proxies for active checks. If port is not specified, default port is
20636 used. If this parameter is not specified, active checks are disabled.
20638 Defaults to @samp{("127.0.0.1")}.
20642 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
20643 Extra options will be appended to Zabbix server configuration file.
20645 Defaults to @samp{""}.
20649 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
20650 You may include individual files or all files in a directory in the
20651 configuration file.
20653 Defaults to @samp{()}.
20657 @c %end of fragment
20659 @subsubheading Zabbix front-end
20660 @cindex zabbix zabbix-front-end
20662 This service provides a WEB interface to Zabbix server.
20664 @c %start of fragment
20666 Available @code{zabbix-front-end-configuration} fields are:
20668 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
20669 NGINX configuration.
20673 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
20674 Database host name.
20676 Defaults to @samp{"localhost"}.
20680 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
20683 Defaults to @samp{5432}.
20687 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
20690 Defaults to @samp{"zabbix"}.
20694 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
20697 Defaults to @samp{"zabbix"}.
20701 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
20702 Database password. Please, use @code{db-secret-file} instead.
20704 Defaults to @samp{""}.
20708 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
20709 Secret file which will be appended to @file{zabbix.conf.php} file. This
20710 file contains credentials for use by Zabbix front-end. You are expected
20711 to create it manually.
20713 Defaults to @samp{""}.
20717 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
20718 Zabbix server hostname.
20720 Defaults to @samp{"localhost"}.
20724 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
20725 Zabbix server port.
20727 Defaults to @samp{10051}.
20732 @c %end of fragment
20734 @node Kerberos Services
20735 @subsection Kerberos Services
20738 The @code{(gnu services kerberos)} module provides services relating to
20739 the authentication protocol @dfn{Kerberos}.
20741 @subsubheading Krb5 Service
20743 Programs using a Kerberos client library normally
20744 expect a configuration file in @file{/etc/krb5.conf}.
20745 This service generates such a file from a definition provided in the
20746 operating system declaration.
20747 It does not cause any daemon to be started.
20749 No ``keytab'' files are provided by this service---you must explicitly create them.
20750 This service is known to work with the MIT client library, @code{mit-krb5}.
20751 Other implementations have not been tested.
20753 @defvr {Scheme Variable} krb5-service-type
20754 A service type for Kerberos 5 clients.
20758 Here is an example of its use:
20760 (service krb5-service-type
20761 (krb5-configuration
20762 (default-realm "EXAMPLE.COM")
20763 (allow-weak-crypto? #t)
20766 (name "EXAMPLE.COM")
20767 (admin-server "groucho.example.com")
20768 (kdc "karl.example.com"))
20771 (admin-server "kerb-admin.argrx.edu")
20772 (kdc "keys.argrx.edu"))))))
20776 This example provides a Kerberos@tie{}5 client configuration which:
20778 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
20779 of which have distinct administration servers and key distribution centers;
20780 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
20781 specified by clients;
20782 @item Accepts services which only support encryption types known to be weak.
20785 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
20786 Only the most commonly used ones are described here.
20787 For a full list, and more detailed explanation of each, see the MIT
20788 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
20792 @deftp {Data Type} krb5-realm
20793 @cindex realm, kerberos
20796 This field is a string identifying the name of the realm.
20797 A common convention is to use the fully qualified DNS name of your organization,
20798 converted to upper case.
20800 @item @code{admin-server}
20801 This field is a string identifying the host where the administration server is
20805 This field is a string identifying the key distribution center
20810 @deftp {Data Type} krb5-configuration
20813 @item @code{allow-weak-crypto?} (default: @code{#f})
20814 If this flag is @code{#t} then services which only offer encryption algorithms
20815 known to be weak will be accepted.
20817 @item @code{default-realm} (default: @code{#f})
20818 This field should be a string identifying the default Kerberos
20819 realm for the client.
20820 You should set this field to the name of your Kerberos realm.
20821 If this value is @code{#f}
20822 then a realm must be specified with every Kerberos principal when invoking programs
20823 such as @command{kinit}.
20825 @item @code{realms}
20826 This should be a non-empty list of @code{krb5-realm} objects, which clients may
20828 Normally, one of them will have a @code{name} field matching the @code{default-realm}
20834 @subsubheading PAM krb5 Service
20837 The @code{pam-krb5} service allows for login authentication and password
20838 management via Kerberos.
20839 You will need this service if you want PAM enabled applications to authenticate
20840 users using Kerberos.
20842 @defvr {Scheme Variable} pam-krb5-service-type
20843 A service type for the Kerberos 5 PAM module.
20846 @deftp {Data Type} pam-krb5-configuration
20847 Data type representing the configuration of the Kerberos 5 PAM module.
20848 This type has the following parameters:
20850 @item @code{pam-krb5} (default: @code{pam-krb5})
20851 The pam-krb5 package to use.
20853 @item @code{minimum-uid} (default: @code{1000})
20854 The smallest user ID for which Kerberos authentications should be attempted.
20855 Local accounts with lower values will silently fail to authenticate.
20860 @node LDAP Services
20861 @subsection LDAP Services
20863 @cindex nslcd, LDAP service
20865 The @code{(gnu services authentication)} module provides the
20866 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
20867 server. In addition to configuring the service itself, you may want to add
20868 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
20869 Switch} for detailed information.
20871 Here is a simple operating system declaration with a default configuration of
20872 the @code{nslcd-service-type} and a Name Service Switch configuration that
20873 consults the @code{ldap} name service last:
20876 (use-service-modules authentication)
20877 (use-modules (gnu system nss))
20883 (service nslcd-service-type)
20884 (service dhcp-client-service-type)
20886 (name-service-switch
20887 (let ((services (list (name-service (name "db"))
20888 (name-service (name "files"))
20889 (name-service (name "ldap")))))
20890 (name-service-switch
20891 (inherit %mdns-host-lookup-nss)
20892 (password services)
20895 (netgroup services)
20896 (gshadow services)))))
20899 @c %start of generated documentation for nslcd-configuration
20901 Available @code{nslcd-configuration} fields are:
20903 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
20904 The @code{nss-pam-ldapd} package to use.
20908 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
20909 The number of threads to start that can handle requests and perform LDAP
20910 queries. Each thread opens a separate connection to the LDAP server.
20911 The default is to start 5 threads.
20913 Defaults to @samp{disabled}.
20917 @deftypevr {@code{nslcd-configuration} parameter} string uid
20918 This specifies the user id with which the daemon should be run.
20920 Defaults to @samp{"nslcd"}.
20924 @deftypevr {@code{nslcd-configuration} parameter} string gid
20925 This specifies the group id with which the daemon should be run.
20927 Defaults to @samp{"nslcd"}.
20931 @deftypevr {@code{nslcd-configuration} parameter} log-option log
20932 This option controls the way logging is done via a list containing
20933 SCHEME and LEVEL. The SCHEME argument may either be the symbols
20934 @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
20935 argument is optional and specifies the log level. The log level may be
20936 one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
20937 @samp{notice}, @samp{info} or @samp{debug}. All messages with the
20938 specified log level or higher are logged.
20940 Defaults to @samp{("/var/log/nslcd" info)}.
20944 @deftypevr {@code{nslcd-configuration} parameter} list uri
20945 The list of LDAP server URIs. Normally, only the first server will be
20946 used with the following servers as fall-back.
20948 Defaults to @samp{("ldap://localhost:389/")}.
20952 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
20953 The version of the LDAP protocol to use. The default is to use the
20954 maximum version supported by the LDAP library.
20956 Defaults to @samp{disabled}.
20960 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
20961 Specifies the distinguished name with which to bind to the directory
20962 server for lookups. The default is to bind anonymously.
20964 Defaults to @samp{disabled}.
20968 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
20969 Specifies the credentials with which to bind. This option is only
20970 applicable when used with binddn.
20972 Defaults to @samp{disabled}.
20976 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
20977 Specifies the distinguished name to use when the root user tries to
20978 modify a user's password using the PAM module.
20980 Defaults to @samp{disabled}.
20984 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
20985 Specifies the credentials with which to bind if the root user tries to
20986 change a user's password. This option is only applicable when used with
20989 Defaults to @samp{disabled}.
20993 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
20994 Specifies the SASL mechanism to be used when performing SASL
20997 Defaults to @samp{disabled}.
21001 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
21002 Specifies the SASL realm to be used when performing SASL authentication.
21004 Defaults to @samp{disabled}.
21008 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
21009 Specifies the authentication identity to be used when performing SASL
21012 Defaults to @samp{disabled}.
21016 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
21017 Specifies the authorization identity to be used when performing SASL
21020 Defaults to @samp{disabled}.
21024 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
21025 Determines whether the LDAP server host name should be canonicalised. If
21026 this is enabled the LDAP library will do a reverse host name lookup. By
21027 default, it is left up to the LDAP library whether this check is
21030 Defaults to @samp{disabled}.
21034 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
21035 Set the name for the GSS-API Kerberos credentials cache.
21037 Defaults to @samp{disabled}.
21041 @deftypevr {@code{nslcd-configuration} parameter} string base
21042 The directory search base.
21044 Defaults to @samp{"dc=example,dc=com"}.
21048 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
21049 Specifies the search scope (subtree, onelevel, base or children). The
21050 default scope is subtree; base scope is almost never useful for name
21051 service lookups; children scope is not supported on all servers.
21053 Defaults to @samp{(subtree)}.
21057 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
21058 Specifies the policy for dereferencing aliases. The default policy is
21059 to never dereference aliases.
21061 Defaults to @samp{disabled}.
21065 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
21066 Specifies whether automatic referral chasing should be enabled. The
21067 default behaviour is to chase referrals.
21069 Defaults to @samp{disabled}.
21073 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
21074 This option allows for custom attributes to be looked up instead of the
21075 default RFC 2307 attributes. It is a list of maps, each consisting of
21076 the name of a map, the RFC 2307 attribute to match and the query
21077 expression for the attribute as it is available in the directory.
21079 Defaults to @samp{()}.
21083 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
21084 A list of filters consisting of the name of a map to which the filter
21085 applies and an LDAP search filter expression.
21087 Defaults to @samp{()}.
21091 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
21092 Specifies the time limit in seconds to use when connecting to the
21093 directory server. The default value is 10 seconds.
21095 Defaults to @samp{disabled}.
21099 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
21100 Specifies the time limit (in seconds) to wait for a response from the
21101 LDAP server. A value of zero, which is the default, is to wait
21102 indefinitely for searches to be completed.
21104 Defaults to @samp{disabled}.
21108 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
21109 Specifies the period if inactivity (in seconds) after which the con‐
21110 nection to the LDAP server will be closed. The default is not to time
21113 Defaults to @samp{disabled}.
21117 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
21118 Specifies the number of seconds to sleep when connecting to all LDAP
21119 servers fails. By default one second is waited between the first
21120 failure and the first retry.
21122 Defaults to @samp{disabled}.
21126 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
21127 Specifies the time after which the LDAP server is considered to be
21128 permanently unavailable. Once this time is reached retries will be done
21129 only once per this time period. The default value is 10 seconds.
21131 Defaults to @samp{disabled}.
21135 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
21136 Specifies whether to use SSL/TLS or not (the default is not to). If
21137 'start-tls is specified then StartTLS is used rather than raw LDAP over
21140 Defaults to @samp{disabled}.
21144 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
21145 Specifies what checks to perform on a server-supplied certificate. The
21146 meaning of the values is described in the ldap.conf(5) manual page.
21148 Defaults to @samp{disabled}.
21152 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
21153 Specifies the directory containing X.509 certificates for peer authen‐
21154 tication. This parameter is ignored when using GnuTLS.
21156 Defaults to @samp{disabled}.
21160 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
21161 Specifies the path to the X.509 certificate for peer authentication.
21163 Defaults to @samp{disabled}.
21167 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
21168 Specifies the path to an entropy source. This parameter is ignored when
21171 Defaults to @samp{disabled}.
21175 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
21176 Specifies the ciphers to use for TLS as a string.
21178 Defaults to @samp{disabled}.
21182 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
21183 Specifies the path to the file containing the local certificate for
21184 client TLS authentication.
21186 Defaults to @samp{disabled}.
21190 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
21191 Specifies the path to the file containing the private key for client TLS
21194 Defaults to @samp{disabled}.
21198 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
21199 Set this to a number greater than 0 to request paged results from the
21200 LDAP server in accordance with RFC2696. The default (0) is to not
21201 request paged results.
21203 Defaults to @samp{disabled}.
21207 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
21208 This option prevents group membership lookups through LDAP for the
21209 specified users. Alternatively, the value 'all-local may be used. With
21210 that value nslcd builds a full list of non-LDAP users on startup.
21212 Defaults to @samp{disabled}.
21216 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
21217 This option ensures that LDAP users with a numeric user id lower than
21218 the specified value are ignored.
21220 Defaults to @samp{disabled}.
21224 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
21225 This option specifies an offset that is added to all LDAP numeric user
21226 ids. This can be used to avoid user id collisions with local users.
21228 Defaults to @samp{disabled}.
21232 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
21233 This option specifies an offset that is added to all LDAP numeric group
21234 ids. This can be used to avoid user id collisions with local groups.
21236 Defaults to @samp{disabled}.
21240 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
21241 If this option is set, the member attribute of a group may point to
21242 another group. Members of nested groups are also returned in the higher
21243 level group and parent groups are returned when finding groups for a
21244 specific user. The default is not to perform extra searches for nested
21247 Defaults to @samp{disabled}.
21251 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
21252 If this option is set, the group member list is not retrieved when
21253 looking up groups. Lookups for finding which groups a user belongs to
21254 will remain functional so the user will likely still get the correct
21255 groups assigned on login.
21257 Defaults to @samp{disabled}.
21261 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
21262 If this option is set, functions which cause all user/group entries to
21263 be loaded from the directory will not succeed in doing so. This can
21264 dramatically reduce LDAP server load in situations where there are a
21265 great number of users and/or groups. This option is not recommended for
21266 most configurations.
21268 Defaults to @samp{disabled}.
21272 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
21273 This option can be used to specify how user and group names are verified
21274 within the system. This pattern is used to check all user and group
21275 names that are requested and returned from LDAP.
21277 Defaults to @samp{disabled}.
21281 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
21282 This specifies whether or not to perform searches using case-insensitive
21283 matching. Enabling this could open up the system to authorization
21284 bypass vulnerabilities and introduce nscd cache poisoning
21285 vulnerabilities which allow denial of service.
21287 Defaults to @samp{disabled}.
21291 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
21292 This option specifies whether password policy controls are requested and
21293 handled from the LDAP server when performing user authentication.
21295 Defaults to @samp{disabled}.
21299 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
21300 By default nslcd performs an LDAP search with the user's credentials
21301 after BIND (authentication) to ensure that the BIND operation was
21302 successful. The default search is a simple check to see if the user's
21303 DN exists. A search filter can be specified that will be used instead.
21304 It should return at least one entry.
21306 Defaults to @samp{disabled}.
21310 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
21311 This option allows flexible fine tuning of the authorisation check that
21312 should be performed. The search filter specified is executed and if any
21313 entries match, access is granted, otherwise access is denied.
21315 Defaults to @samp{disabled}.
21319 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
21320 If this option is set password modification using pam_ldap will be
21321 denied and the specified message will be presented to the user instead.
21322 The message can be used to direct the user to an alternative means of
21323 changing their password.
21325 Defaults to @samp{disabled}.
21329 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
21330 List of pam service names for which LDAP authentication should suffice.
21332 Defaults to @samp{()}.
21336 @c %end of generated documentation for nslcd-configuration
21340 @subsection Web Services
21345 The @code{(gnu services web)} module provides the Apache HTTP Server,
21346 the nginx web server, and also a fastcgi wrapper daemon.
21348 @subsubheading Apache HTTP Server
21350 @deffn {Scheme Variable} httpd-service-type
21351 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
21352 (@dfn{httpd}). The value for this service type is a
21353 @code{httpd-configuration} record.
21355 A simple example configuration is given below.
21358 (service httpd-service-type
21359 (httpd-configuration
21362 (server-name "www.example.com")
21363 (document-root "/srv/http/www.example.com")))))
21366 Other services can also extend the @code{httpd-service-type} to add to
21370 (simple-service 'www.example.com-server httpd-service-type
21374 (list (string-join '("ServerName www.example.com"
21375 "DocumentRoot /srv/http/www.example.com")
21380 The details for the @code{httpd-configuration}, @code{httpd-module},
21381 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
21384 @deffn {Data Type} httpd-configuration
21385 This data type represents the configuration for the httpd service.
21388 @item @code{package} (default: @code{httpd})
21389 The httpd package to use.
21391 @item @code{pid-file} (default: @code{"/var/run/httpd"})
21392 The pid file used by the shepherd-service.
21394 @item @code{config} (default: @code{(httpd-config-file)})
21395 The configuration file to use with the httpd service. The default value
21396 is a @code{httpd-config-file} record, but this can also be a different
21397 G-expression that generates a file, for example a @code{plain-file}. A
21398 file outside of the store can also be specified through a string.
21403 @deffn {Data Type} httpd-module
21404 This data type represents a module for the httpd service.
21408 The name of the module.
21411 The file for the module. This can be relative to the httpd package being
21412 used, the absolute location of a file, or a G-expression for a file
21413 within the store, for example @code{(file-append mod-wsgi
21414 "/modules/mod_wsgi.so")}.
21419 @defvr {Scheme Variable} %default-httpd-modules
21420 A default list of @code{httpd-module} objects.
21423 @deffn {Data Type} httpd-config-file
21424 This data type represents a configuration file for the httpd service.
21427 @item @code{modules} (default: @code{%default-httpd-modules})
21428 The modules to load. Additional modules can be added here, or loaded by
21429 additional configuration.
21431 For example, in order to handle requests for PHP files, you can use Apache’s
21432 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
21435 (service httpd-service-type
21436 (httpd-configuration
21441 (name "proxy_module")
21442 (file "modules/mod_proxy.so"))
21444 (name "proxy_fcgi_module")
21445 (file "modules/mod_proxy_fcgi.so"))
21446 %default-httpd-modules))
21447 (extra-config (list "\
21448 <FilesMatch \\.php$>
21449 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
21450 </FilesMatch>"))))))
21451 (service php-fpm-service-type
21452 (php-fpm-configuration
21453 (socket "/var/run/php-fpm.sock")
21454 (socket-group "httpd")))
21457 @item @code{server-root} (default: @code{httpd})
21458 The @code{ServerRoot} in the configuration file, defaults to the httpd
21459 package. Directives including @code{Include} and @code{LoadModule} are
21460 taken as relative to the server root.
21462 @item @code{server-name} (default: @code{#f})
21463 The @code{ServerName} in the configuration file, used to specify the
21464 request scheme, hostname and port that the server uses to identify
21467 This doesn't need to be set in the server config, and can be specified
21468 in virtual hosts. The default is @code{#f} to not specify a
21471 @item @code{document-root} (default: @code{"/srv/http"})
21472 The @code{DocumentRoot} from which files will be served.
21474 @item @code{listen} (default: @code{'("80")})
21475 The list of values for the @code{Listen} directives in the config
21476 file. The value should be a list of strings, when each string can
21477 specify the port number to listen on, and optionally the IP address and
21480 @item @code{pid-file} (default: @code{"/var/run/httpd"})
21481 The @code{PidFile} to use. This should match the @code{pid-file} set in
21482 the @code{httpd-configuration} so that the Shepherd service is
21483 configured correctly.
21485 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
21486 The @code{ErrorLog} to which the server will log errors.
21488 @item @code{user} (default: @code{"httpd"})
21489 The @code{User} which the server will answer requests as.
21491 @item @code{group} (default: @code{"httpd"})
21492 The @code{Group} which the server will answer requests as.
21494 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
21495 A flat list of strings and G-expressions which will be added to the end
21496 of the configuration file.
21498 Any values which the service is extended with will be appended to this
21504 @deffn {Data Type} httpd-virtualhost
21505 This data type represents a virtualhost configuration block for the httpd service.
21507 These should be added to the extra-config for the httpd-service.
21510 (simple-service 'www.example.com-server httpd-service-type
21514 (list (string-join '("ServerName www.example.com"
21515 "DocumentRoot /srv/http/www.example.com")
21520 @item @code{addresses-and-ports}
21521 The addresses and ports for the @code{VirtualHost} directive.
21523 @item @code{contents}
21524 The contents of the @code{VirtualHost} directive, this should be a list
21525 of strings and G-expressions.
21530 @subsubheading NGINX
21532 @deffn {Scheme Variable} nginx-service-type
21533 Service type for the @uref{https://nginx.org/,NGinx} web server. The
21534 value for this service type is a @code{<nginx-configuration>} record.
21536 A simple example configuration is given below.
21539 (service nginx-service-type
21540 (nginx-configuration
21542 (list (nginx-server-configuration
21543 (server-name '("www.example.com"))
21544 (root "/srv/http/www.example.com"))))))
21547 In addition to adding server blocks to the service configuration
21548 directly, this service can be extended by other services to add server
21549 blocks, as in this example:
21552 (simple-service 'my-extra-server nginx-service-type
21553 (list (nginx-server-configuration
21554 (root "/srv/http/extra-website")
21555 (try-files (list "$uri" "$uri/index.html")))))
21559 At startup, @command{nginx} has not yet read its configuration file, so
21560 it uses a default file to log error messages. If it fails to load its
21561 configuration file, that is where error messages are logged. After the
21562 configuration file is loaded, the default error log file changes as per
21563 configuration. In our case, startup error messages can be found in
21564 @file{/var/run/nginx/logs/error.log}, and after configuration in
21565 @file{/var/log/nginx/error.log}. The second location can be changed
21566 with the @var{log-directory} configuration option.
21568 @deffn {Data Type} nginx-configuration
21569 This data type represents the configuration for NGinx. Some
21570 configuration can be done through this and the other provided record
21571 types, or alternatively, a config file can be provided.
21574 @item @code{nginx} (default: @code{nginx})
21575 The nginx package to use.
21577 @item @code{log-directory} (default: @code{"/var/log/nginx"})
21578 The directory to which NGinx will write log files.
21580 @item @code{run-directory} (default: @code{"/var/run/nginx"})
21581 The directory in which NGinx will create a pid file, and write temporary
21584 @item @code{server-blocks} (default: @code{'()})
21585 A list of @dfn{server blocks} to create in the generated configuration
21586 file, the elements should be of type
21587 @code{<nginx-server-configuration>}.
21589 The following example would setup NGinx to serve @code{www.example.com}
21590 from the @code{/srv/http/www.example.com} directory, without using
21593 (service nginx-service-type
21594 (nginx-configuration
21596 (list (nginx-server-configuration
21597 (server-name '("www.example.com"))
21598 (root "/srv/http/www.example.com"))))))
21601 @item @code{upstream-blocks} (default: @code{'()})
21602 A list of @dfn{upstream blocks} to create in the generated configuration
21603 file, the elements should be of type
21604 @code{<nginx-upstream-configuration>}.
21606 Configuring upstreams through the @code{upstream-blocks} can be useful
21607 when combined with @code{locations} in the
21608 @code{<nginx-server-configuration>} records. The following example
21609 creates a server configuration with one location configuration, that
21610 will proxy requests to a upstream configuration, which will handle
21611 requests with two servers.
21616 (nginx-configuration
21618 (list (nginx-server-configuration
21619 (server-name '("www.example.com"))
21620 (root "/srv/http/www.example.com")
21623 (nginx-location-configuration
21625 (body '("proxy_pass http://server-proxy;"))))))))
21627 (list (nginx-upstream-configuration
21628 (name "server-proxy")
21629 (servers (list "server1.example.com"
21630 "server2.example.com")))))))
21633 @item @code{file} (default: @code{#f})
21634 If a configuration @var{file} is provided, this will be used, rather than
21635 generating a configuration file from the provided @code{log-directory},
21636 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
21637 proper operation, these arguments should match what is in @var{file} to ensure
21638 that the directories are created when the service is activated.
21640 This can be useful if you have an existing configuration file, or it's
21641 not possible to do what is required through the other parts of the
21642 nginx-configuration record.
21644 @item @code{server-names-hash-bucket-size} (default: @code{#f})
21645 Bucket size for the server names hash tables, defaults to @code{#f} to
21646 use the size of the processors cache line.
21648 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
21649 Maximum bucket size for the server names hash tables.
21651 @item @code{modules} (default: @code{'()})
21652 List of nginx dynamic modules to load. This should be a list of file
21653 names of loadable modules, as in this example:
21658 (file-append nginx-accept-language-module "\
21659 /etc/nginx/modules/ngx_http_accept_language_module.so")))
21662 @item @code{global-directives} (default: @code{'((events . ()))})
21663 Association list of global directives for the top level of the nginx
21664 configuration. Values may themselves be association lists.
21668 `((worker_processes . 16)
21670 (events . ((worker_connections . 1024)))))
21673 @item @code{extra-content} (default: @code{""})
21674 Extra content for the @code{http} block. Should be string or a string
21675 valued G-expression.
21680 @deftp {Data Type} nginx-server-configuration
21681 Data type representing the configuration of an nginx server block.
21682 This type has the following parameters:
21685 @item @code{listen} (default: @code{'("80" "443 ssl")})
21686 Each @code{listen} directive sets the address and port for IP, or the
21687 path for a UNIX-domain socket on which the server will accept requests.
21688 Both address and port, or only address or only port can be specified.
21689 An address may also be a hostname, for example:
21692 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
21695 @item @code{server-name} (default: @code{(list 'default)})
21696 A list of server names this server represents. @code{'default} represents the
21697 default server for connections matching no other server.
21699 @item @code{root} (default: @code{"/srv/http"})
21700 Root of the website nginx will serve.
21702 @item @code{locations} (default: @code{'()})
21703 A list of @dfn{nginx-location-configuration} or
21704 @dfn{nginx-named-location-configuration} records to use within this
21707 @item @code{index} (default: @code{(list "index.html")})
21708 Index files to look for when clients ask for a directory. If it cannot be found,
21709 Nginx will send the list of files in the directory.
21711 @item @code{try-files} (default: @code{'()})
21712 A list of files whose existence is checked in the specified order.
21713 @code{nginx} will use the first file it finds to process the request.
21715 @item @code{ssl-certificate} (default: @code{#f})
21716 Where to find the certificate for secure connections. Set it to @code{#f} if
21717 you don't have a certificate or you don't want to use HTTPS.
21719 @item @code{ssl-certificate-key} (default: @code{#f})
21720 Where to find the private key for secure connections. Set it to @code{#f} if
21721 you don't have a key or you don't want to use HTTPS.
21723 @item @code{server-tokens?} (default: @code{#f})
21724 Whether the server should add its configuration to response.
21726 @item @code{raw-content} (default: @code{'()})
21727 A list of raw lines added to the server block.
21732 @deftp {Data Type} nginx-upstream-configuration
21733 Data type representing the configuration of an nginx @code{upstream}
21734 block. This type has the following parameters:
21738 Name for this group of servers.
21740 @item @code{servers}
21741 Specify the addresses of the servers in the group. The address can be
21742 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
21743 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
21744 prefix @samp{unix:}. For addresses using an IP address or domain name,
21745 the default port is 80, and a different port can be specified
21751 @deftp {Data Type} nginx-location-configuration
21752 Data type representing the configuration of an nginx @code{location}
21753 block. This type has the following parameters:
21757 URI which this location block matches.
21759 @anchor{nginx-location-configuration body}
21761 Body of the location block, specified as a list of strings. This can contain
21763 configuration directives. For example, to pass requests to a upstream
21764 server group defined using an @code{nginx-upstream-configuration} block,
21765 the following directive would be specified in the body @samp{(list "proxy_pass
21766 http://upstream-name;")}.
21771 @deftp {Data Type} nginx-named-location-configuration
21772 Data type representing the configuration of an nginx named location
21773 block. Named location blocks are used for request redirection, and not
21774 used for regular request processing. This type has the following
21779 Name to identify this location block.
21782 @xref{nginx-location-configuration body}, as the body for named location
21783 blocks can be used in a similar way to the
21784 @code{nginx-location-configuration body}. One restriction is that the
21785 body of a named location block cannot contain location blocks.
21790 @subsubheading Varnish Cache
21792 Varnish is a fast cache server that sits in between web applications
21793 and end users. It proxies requests from clients and caches the
21794 accessed URLs such that multiple requests for the same resource only
21795 creates one request to the back-end.
21797 @defvr {Scheme Variable} varnish-service-type
21798 Service type for the Varnish daemon.
21801 @deftp {Data Type} varnish-configuration
21802 Data type representing the @code{varnish} service configuration.
21803 This type has the following parameters:
21806 @item @code{package} (default: @code{varnish})
21807 The Varnish package to use.
21809 @item @code{name} (default: @code{"default"})
21810 A name for this Varnish instance. Varnish will create a directory in
21811 @file{/var/varnish/} with this name and keep temporary files there. If
21812 the name starts with a forward slash, it is interpreted as an absolute
21815 Pass the @code{-n} argument to other Varnish programs to connect to the
21816 named instance, e.g.@: @command{varnishncsa -n default}.
21818 @item @code{backend} (default: @code{"localhost:8080"})
21819 The backend to use. This option has no effect if @code{vcl} is set.
21821 @item @code{vcl} (default: #f)
21822 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
21823 is @code{#f}, Varnish will proxy @code{backend} using the default
21824 configuration. Otherwise this must be a file-like object with valid
21827 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
21828 For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
21829 can do something along these lines:
21832 (define %gnu-mirror
21833 (plain-file "gnu.vcl"
21835 backend gnu @{ .host = \"www.gnu.org\"; @}"))
21839 (services (cons (service varnish-service-type
21840 (varnish-configuration
21842 (vcl %gnu-mirror)))
21846 The configuration of an already running Varnish instance can be inspected
21847 and changed using the @command{varnishadm} program.
21849 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
21850 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
21851 comprehensive documentation on Varnish and its configuration language.
21853 @item @code{listen} (default: @code{'("localhost:80")})
21854 List of addresses Varnish will listen on.
21856 @item @code{storage} (default: @code{'("malloc,128m")})
21857 List of storage backends that will be available in VCL.
21859 @item @code{parameters} (default: @code{'()})
21860 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
21862 @item @code{extra-options} (default: @code{'()})
21863 Additional arguments to pass to the @command{varnishd} process.
21868 @subsubheading Patchwork
21870 Patchwork is a patch tracking system. It can collect patches sent to a
21871 mailing list, and display them in a web interface.
21873 @defvr {Scheme Variable} patchwork-service-type
21874 Service type for Patchwork.
21877 The following example is an example of a minimal service for Patchwork, for
21878 the @code{patchwork.example.com} domain.
21881 (service patchwork-service-type
21882 (patchwork-configuration
21883 (domain "patchwork.example.com")
21885 (patchwork-settings-module
21886 (allowed-hosts (list domain))
21887 (default-from-email "patchwork@@patchwork.example.com")))
21888 (getmail-retriever-config
21889 (getmail-retriever-configuration
21890 (type "SimpleIMAPSSLRetriever")
21891 (server "imap.example.com")
21893 (username "patchwork")
21895 (list (file-append coreutils "/bin/cat")
21896 "/etc/getmail-patchwork-imap-password"))
21898 '((mailboxes . ("Patches"))))))))
21902 There are three records for configuring the Patchwork service. The
21903 @code{<patchwork-configuration>} relates to the configuration for Patchwork
21904 within the HTTPD service.
21906 The @code{settings-module} field within the @code{<patchwork-configuration>}
21907 record can be populated with the @code{<patchwork-settings-module>} record,
21908 which describes a settings module that is generated within the Guix store.
21910 For the @code{database-configuration} field within the
21911 @code{<patchwork-settings-module>}, the
21912 @code{<patchwork-database-configuration>} must be used.
21914 @deftp {Data Type} patchwork-configuration
21915 Data type representing the Patchwork service configuration. This type has the
21916 following parameters:
21919 @item @code{patchwork} (default: @code{patchwork})
21920 The Patchwork package to use.
21922 @item @code{domain}
21923 The domain to use for Patchwork, this is used in the HTTPD service virtual
21926 @item @code{settings-module}
21927 The settings module to use for Patchwork. As a Django application, Patchwork
21928 is configured with a Python module containing the settings. This can either be
21929 an instance of the @code{<patchwork-settings-module>} record, any other record
21930 that represents the settings in the store, or a directory outside of the
21933 @item @code{static-path} (default: @code{"/static/"})
21934 The path under which the HTTPD service should serve the static files.
21936 @item @code{getmail-retriever-config}
21937 The getmail-retriever-configuration record value to use with
21938 Patchwork. Getmail will be configured with this value, the messages will be
21939 delivered to Patchwork.
21944 @deftp {Data Type} patchwork-settings-module
21945 Data type representing a settings module for Patchwork. Some of these
21946 settings relate directly to Patchwork, but others relate to Django, the web
21947 framework used by Patchwork, or the Django Rest Framework library. This type
21948 has the following parameters:
21951 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
21952 The database connection settings used for Patchwork. See the
21953 @code{<patchwork-database-configuration>} record type for more information.
21955 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
21956 Patchwork, as a Django web application uses a secret key for cryptographically
21957 signing values. This file should contain a unique unpredictable value.
21959 If this file does not exist, it will be created and populated with a random
21960 value by the patchwork-setup shepherd service.
21962 This setting relates to Django.
21964 @item @code{allowed-hosts}
21965 A list of valid hosts for this Patchwork service. This should at least include
21966 the domain specified in the @code{<patchwork-configuration>} record.
21968 This is a Django setting.
21970 @item @code{default-from-email}
21971 The email address from which Patchwork should send email by default.
21973 This is a Patchwork setting.
21975 @item @code{static-url} (default: @code{#f})
21976 The URL to use when serving static assets. It can be part of a URL, or a full
21977 URL, but must end in a @code{/}.
21979 If the default value is used, the @code{static-path} value from the
21980 @code{<patchwork-configuration>} record will be used.
21982 This is a Django setting.
21984 @item @code{admins} (default: @code{'()})
21985 Email addresses to send the details of errors that occur. Each value should
21986 be a list containing two elements, the name and then the email address.
21988 This is a Django setting.
21990 @item @code{debug?} (default: @code{#f})
21991 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
21992 messages will be shown.
21994 This is a Django setting.
21996 @item @code{enable-rest-api?} (default: @code{#t})
21997 Whether to enable the Patchwork REST API.
21999 This is a Patchwork setting.
22001 @item @code{enable-xmlrpc?} (default: @code{#t})
22002 Whether to enable the XML RPC API.
22004 This is a Patchwork setting.
22006 @item @code{force-https-links?} (default: @code{#t})
22007 Whether to use HTTPS links on Patchwork pages.
22009 This is a Patchwork setting.
22011 @item @code{extra-settings} (default: @code{""})
22012 Extra code to place at the end of the Patchwork settings module.
22017 @deftp {Data Type} patchwork-database-configuration
22018 Data type representing the database configuration for Patchwork.
22021 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
22022 The database engine to use.
22024 @item @code{name} (default: @code{"patchwork"})
22025 The name of the database to use.
22027 @item @code{user} (default: @code{"httpd"})
22028 The user to connect to the database as.
22030 @item @code{password} (default: @code{""})
22031 The password to use when connecting to the database.
22033 @item @code{host} (default: @code{""})
22034 The host to make the database connection to.
22036 @item @code{port} (default: @code{""})
22037 The port on which to connect to the database.
22042 @subsubheading Mumi
22044 @cindex Mumi, Debbugs Web interface
22045 @cindex Debbugs, Mumi Web interface
22046 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
22047 Web interface to the Debbugs bug tracker, by default for
22048 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
22049 but it also fetches and indexes mail retrieved from Debbugs.
22051 @defvr {Scheme Variable} mumi-service-type
22052 This is the service type for Mumi.
22055 @deftp {Data Type} mumi-configuration
22056 Data type representing the Mumi service configuration. This type has the
22060 @item @code{mumi} (default: @code{mumi})
22061 The Mumi package to use.
22063 @item @code{mailer?} (default: @code{#true})
22064 Whether to enable or disable the mailer component.
22066 @item @code{mumi-configuration-sender}
22067 The email address used as the sender for comments.
22069 @item @code{mumi-configuration-smtp}
22070 A URI to configure the SMTP settings for Mailutils. This could be
22071 something like @code{sendmail:///path/to/bin/msmtp} or any other URI
22072 supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
22073 mailutils, GNU@tie{}Mailutils}.
22079 @subsubheading FastCGI
22082 FastCGI is an interface between the front-end and the back-end of a web
22083 service. It is a somewhat legacy facility; new web services should
22084 generally just talk HTTP between the front-end and the back-end.
22085 However there are a number of back-end services such as PHP or the
22086 optimized HTTP Git repository access that use FastCGI, so we have
22087 support for it in Guix.
22089 To use FastCGI, you configure the front-end web server (e.g., nginx) to
22090 dispatch some subset of its requests to the fastcgi backend, which
22091 listens on a local TCP or UNIX socket. There is an intermediary
22092 @code{fcgiwrap} program that sits between the actual backend process and
22093 the web server. The front-end indicates which backend program to run,
22094 passing that information to the @code{fcgiwrap} process.
22096 @defvr {Scheme Variable} fcgiwrap-service-type
22097 A service type for the @code{fcgiwrap} FastCGI proxy.
22100 @deftp {Data Type} fcgiwrap-configuration
22101 Data type representing the configuration of the @code{fcgiwrap} service.
22102 This type has the following parameters:
22104 @item @code{package} (default: @code{fcgiwrap})
22105 The fcgiwrap package to use.
22107 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
22108 The socket on which the @code{fcgiwrap} process should listen, as a
22109 string. Valid @var{socket} values include
22110 @code{unix:@var{/path/to/unix/socket}},
22111 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
22112 @code{tcp6:[@var{ipv6_addr}]:port}.
22114 @item @code{user} (default: @code{fcgiwrap})
22115 @itemx @code{group} (default: @code{fcgiwrap})
22116 The user and group names, as strings, under which to run the
22117 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
22118 the user asks for the specific user or group names @code{fcgiwrap} that
22119 the corresponding user and/or group is present on the system.
22121 It is possible to configure a FastCGI-backed web service to pass HTTP
22122 authentication information from the front-end to the back-end, and to
22123 allow @code{fcgiwrap} to run the back-end process as a corresponding
22124 local user. To enable this capability on the back-end, run
22125 @code{fcgiwrap} as the @code{root} user and group. Note that this
22126 capability also has to be configured on the front-end as well.
22131 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
22132 with some additional features useful for sites of any size.
22134 These features include:
22136 @item Adaptive process spawning
22137 @item Basic statistics (similar to Apache's mod_status)
22138 @item Advanced process management with graceful stop/start
22139 @item Ability to start workers with different uid/gid/chroot/environment
22140 and different php.ini (replaces safe_mode)
22141 @item Stdout & stderr logging
22142 @item Emergency restart in case of accidental opcode cache destruction
22143 @item Accelerated upload support
22144 @item Support for a "slowlog"
22145 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
22146 a special function to finish request & flush all data while continuing to do
22147 something time-consuming (video converting, stats processing, etc.)
22149 ...@: and much more.
22151 @defvr {Scheme Variable} php-fpm-service-type
22152 A Service type for @code{php-fpm}.
22155 @deftp {Data Type} php-fpm-configuration
22156 Data Type for php-fpm service configuration.
22158 @item @code{php} (default: @code{php})
22159 The php package to use.
22160 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
22161 The address on which to accept FastCGI requests. Valid syntaxes are:
22163 @item @code{"ip.add.re.ss:port"}
22164 Listen on a TCP socket to a specific address on a specific port.
22165 @item @code{"port"}
22166 Listen on a TCP socket to all addresses on a specific port.
22167 @item @code{"/path/to/unix/socket"}
22168 Listen on a unix socket.
22171 @item @code{user} (default: @code{php-fpm})
22172 User who will own the php worker processes.
22173 @item @code{group} (default: @code{php-fpm})
22174 Group of the worker processes.
22175 @item @code{socket-user} (default: @code{php-fpm})
22176 User who can speak to the php-fpm socket.
22177 @item @code{socket-group} (default: @code{nginx})
22178 Group that can speak to the php-fpm socket.
22179 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
22180 The process id of the php-fpm process is written to this file
22181 once the service has started.
22182 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
22183 Log for the php-fpm master process.
22184 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
22185 Detailed settings for the php-fpm process manager.
22188 @item @code{<php-fpm-dynamic-process-manager-configuration>}
22189 @item @code{<php-fpm-static-process-manager-configuration>}
22190 @item @code{<php-fpm-on-demand-process-manager-configuration>}
22192 @item @code{display-errors} (default @code{#f})
22193 Determines whether php errors and warning should be sent to clients
22194 and displayed in their browsers.
22195 This is useful for local php development, but a security risk for public sites,
22196 as error messages can reveal passwords and personal data.
22197 @item @code{timezone} (default @code{#f})
22198 Specifies @code{php_admin_value[date.timezone]} parameter.
22199 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
22200 This file will log the @code{stderr} outputs of php worker processes.
22201 Can be set to @code{#f} to disable logging.
22202 @item @code{file} (default @code{#f})
22203 An optional override of the whole configuration.
22204 You can use the @code{mixed-text-file} function or an absolute filepath for it.
22205 @item @code{php-ini-file} (default @code{#f})
22206 An optional override of the default php settings.
22207 It may be any ``file-like'' object (@pxref{G-Expressions, file-like objects}).
22208 You can use the @code{mixed-text-file} function or an absolute filepath for it.
22210 For local development it is useful to set a higher timeout and memory
22211 limit for spawned php processes. This be accomplished with the
22212 following operating system configuration snippet:
22214 (define %local-php-ini
22215 (plain-file "php.ini"
22217 max_execution_time = 1800"))
22221 (services (cons (service php-fpm-service-type
22222 (php-fpm-configuration
22223 (php-ini-file %local-php-ini)))
22227 Consult the @url{https://www.php.net/manual/en/ini.core.php,core php.ini
22228 directives} for comprehensive documentation on the acceptable
22229 @file{php.ini} directives.
22233 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
22234 Data Type for the @code{dynamic} php-fpm process manager. With the
22235 @code{dynamic} process manager, spare worker processes are kept around
22236 based on it's configured limits.
22238 @item @code{max-children} (default: @code{5})
22239 Maximum of worker processes.
22240 @item @code{start-servers} (default: @code{2})
22241 How many worker processes should be started on start-up.
22242 @item @code{min-spare-servers} (default: @code{1})
22243 How many spare worker processes should be kept around at minimum.
22244 @item @code{max-spare-servers} (default: @code{3})
22245 How many spare worker processes should be kept around at maximum.
22249 @deftp {Data type} php-fpm-static-process-manager-configuration
22250 Data Type for the @code{static} php-fpm process manager. With the
22251 @code{static} process manager, an unchanging number of worker processes
22254 @item @code{max-children} (default: @code{5})
22255 Maximum of worker processes.
22259 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
22260 Data Type for the @code{on-demand} php-fpm process manager. With the
22261 @code{on-demand} process manager, worker processes are only created as
22264 @item @code{max-children} (default: @code{5})
22265 Maximum of worker processes.
22266 @item @code{process-idle-timeout} (default: @code{10})
22267 The time in seconds after which a process with no requests is killed.
22272 @deffn {Scheme Procedure} nginx-php-location @
22273 [#:nginx-package nginx] @
22274 [socket (string-append "/var/run/php" @
22275 (version-major (package-version php)) @
22277 A helper function to quickly add php to an @code{nginx-server-configuration}.
22280 A simple services setup for nginx with php can look like this:
22282 (services (cons* (service dhcp-client-service-type)
22283 (service php-fpm-service-type)
22284 (service nginx-service-type
22285 (nginx-server-configuration
22286 (server-name '("example.com"))
22287 (root "/srv/http/")
22289 (list (nginx-php-location)))
22291 (ssl-certificate #f)
22292 (ssl-certificate-key #f)))
22296 @cindex cat-avatar-generator
22297 The cat avatar generator is a simple service to demonstrate the use of php-fpm
22298 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
22299 the hash of a user's email address.
22301 @deffn {Scheme Procedure} cat-avatar-generator-service @
22302 [#:cache-dir "/var/cache/cat-avatar-generator"] @
22303 [#:package cat-avatar-generator] @
22304 [#:configuration (nginx-server-configuration)]
22305 Returns an nginx-server-configuration that inherits @code{configuration}. It
22306 extends the nginx configuration to add a server block that serves @code{package},
22307 a version of cat-avatar-generator. During execution, cat-avatar-generator will
22308 be able to use @code{cache-dir} as its cache directory.
22311 A simple setup for cat-avatar-generator can look like this:
22313 (services (cons* (cat-avatar-generator-service
22315 (nginx-server-configuration
22316 (server-name '("example.com"))))
22321 @subsubheading Hpcguix-web
22323 @cindex hpcguix-web
22324 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
22325 program is a customizable web interface to browse Guix packages,
22326 initially designed for users of high-performance computing (HPC)
22329 @defvr {Scheme Variable} hpcguix-web-service-type
22330 The service type for @code{hpcguix-web}.
22333 @deftp {Data Type} hpcguix-web-configuration
22334 Data type for the hpcguix-web service configuration.
22338 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
22339 configuration. The main items available in this spec are:
22342 @item @code{title-prefix} (default: @code{"hpcguix | "})
22343 The page title prefix.
22345 @item @code{guix-command} (default: @code{"guix"})
22346 The @command{guix} command.
22348 @item @code{package-filter-proc} (default: @code{(const #t)})
22349 A procedure specifying how to filter packages that are displayed.
22351 @item @code{package-page-extension-proc} (default: @code{(const '())})
22352 Extension package for @code{hpcguix-web}.
22354 @item @code{menu} (default: @code{'()})
22355 Additional entry in page @code{menu}.
22357 @item @code{channels} (default: @code{%default-channels})
22358 List of channels from which the package list is built (@pxref{Channels}).
22360 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
22361 The expiration time, in seconds, after which the package list is rebuilt from
22362 the latest instances of the given channels.
22365 See the hpcguix-web repository for a
22366 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
22369 @item @code{package} (default: @code{hpcguix-web})
22370 The hpcguix-web package to use.
22374 A typical hpcguix-web service declaration looks like this:
22377 (service hpcguix-web-service-type
22378 (hpcguix-web-configuration
22380 #~(define site-config
22381 (hpcweb-configuration
22382 (title-prefix "Guix-HPC - ")
22383 (menu '(("/about" "ABOUT"))))))))
22387 The hpcguix-web service periodically updates the package list it publishes by
22388 pulling channels from Git. To that end, it needs to access X.509 certificates
22389 so that it can authenticate Git servers when communicating over HTTPS, and it
22390 assumes that @file{/etc/ssl/certs} contains those certificates.
22392 Thus, make sure to add @code{nss-certs} or another certificate package to the
22393 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
22394 more information on X.509 certificates.
22397 @node Certificate Services
22398 @subsection Certificate Services
22401 @cindex HTTP, HTTPS
22402 @cindex Let's Encrypt
22403 @cindex TLS certificates
22404 The @code{(gnu services certbot)} module provides a service to
22405 automatically obtain a valid TLS certificate from the Let's Encrypt
22406 certificate authority. These certificates can then be used to serve
22407 content securely over HTTPS or other TLS-based protocols, with the
22408 knowledge that the client will be able to verify the server's
22411 @url{https://letsencrypt.org/, Let's Encrypt} provides the
22412 @code{certbot} tool to automate the certification process. This tool
22413 first securely generates a key on the server. It then makes a request
22414 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
22415 checks that the request originates from the host in question by using a
22416 challenge-response protocol, requiring the server to provide its
22417 response over HTTP. If that protocol completes successfully, the CA
22418 signs the key, resulting in a certificate. That certificate is valid
22419 for a limited period of time, and therefore to continue to provide TLS
22420 services, the server needs to periodically ask the CA to renew its
22423 The certbot service automates this process: the initial key
22424 generation, the initial certification request to the Let's Encrypt
22425 service, the web server challenge/response integration, writing the
22426 certificate to disk, the automated periodic renewals, and the deployment
22427 tasks associated with the renewal (e.g.@: reloading services, copying keys
22428 with different permissions).
22430 Certbot is run twice a day, at a random minute within the hour. It
22431 won't do anything until your certificates are due for renewal or
22432 revoked, but running it regularly would give your service a chance of
22433 staying online in case a Let's Encrypt-initiated revocation happened for
22436 By using this service, you agree to the ACME Subscriber Agreement, which
22437 can be found there:
22438 @url{https://acme-v01.api.letsencrypt.org/directory}.
22440 @defvr {Scheme Variable} certbot-service-type
22441 A service type for the @code{certbot} Let's Encrypt client. Its value
22442 must be a @code{certbot-configuration} record as in this example:
22445 (define %nginx-deploy-hook
22447 "nginx-deploy-hook"
22448 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
22449 (kill pid SIGHUP))))
22451 (service certbot-service-type
22452 (certbot-configuration
22453 (email "foo@@example.net")
22456 (certificate-configuration
22457 (domains '("example.net" "www.example.net"))
22458 (deploy-hook %nginx-deploy-hook))
22459 (certificate-configuration
22460 (domains '("bar.example.net")))))))
22463 See below for details about @code{certbot-configuration}.
22466 @deftp {Data Type} certbot-configuration
22467 Data type representing the configuration of the @code{certbot} service.
22468 This type has the following parameters:
22471 @item @code{package} (default: @code{certbot})
22472 The certbot package to use.
22474 @item @code{webroot} (default: @code{/var/www})
22475 The directory from which to serve the Let's Encrypt challenge/response
22478 @item @code{certificates} (default: @code{()})
22479 A list of @code{certificates-configuration}s for which to generate
22480 certificates and request signatures. Each certificate has a @code{name}
22481 and several @code{domains}.
22483 @item @code{email} (default: @code{#f})
22484 Optional email address used for registration and recovery contact.
22485 Setting this is encouraged as it allows you to receive important
22486 notifications about the account and issued certificates.
22488 @item @code{server} (default: @code{#f})
22489 Optional URL of ACME server. Setting this overrides certbot's default,
22490 which is the Let's Encrypt server.
22492 @item @code{rsa-key-size} (default: @code{2048})
22493 Size of the RSA key.
22495 @item @code{default-location} (default: @i{see below})
22496 The default @code{nginx-location-configuration}. Because @code{certbot}
22497 needs to be able to serve challenges and responses, it needs to be able
22498 to run a web server. It does so by extending the @code{nginx} web
22499 service with an @code{nginx-server-configuration} listening on the
22500 @var{domains} on port 80, and which has a
22501 @code{nginx-location-configuration} for the @code{/.well-known/} URI
22502 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
22503 these nginx configuration data types.
22505 Requests to other URL paths will be matched by the
22506 @code{default-location}, which if present is added to all
22507 @code{nginx-server-configuration}s.
22509 By default, the @code{default-location} will issue a redirect from
22510 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
22511 you to define what to serve on your site via @code{https}.
22513 Pass @code{#f} to not issue a default location.
22517 @deftp {Data Type} certificate-configuration
22518 Data type representing the configuration of a certificate.
22519 This type has the following parameters:
22522 @item @code{name} (default: @i{see below})
22523 This name is used by Certbot for housekeeping and in file paths; it
22524 doesn't affect the content of the certificate itself. To see
22525 certificate names, run @code{certbot certificates}.
22527 Its default is the first provided domain.
22529 @item @code{domains} (default: @code{()})
22530 The first domain provided will be the subject CN of the certificate, and
22531 all domains will be Subject Alternative Names on the certificate.
22533 @item @code{challenge} (default: @code{#f})
22534 The challenge type that has to be run by certbot. If @code{#f} is specified,
22535 default to the HTTP challenge. If a value is specified, defaults to the
22536 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
22537 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
22538 and gives Let's Encrypt permission to log the public IP address of the
22539 requesting machine.
22541 @item @code{authentication-hook} (default: @code{#f})
22542 Command to be run in a shell once for each certificate challenge to be
22543 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
22544 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
22545 contains the validation string and @code{$CERTBOT_TOKEN} contains the
22546 file name of the resource requested when performing an HTTP-01 challenge.
22548 @item @code{cleanup-hook} (default: @code{#f})
22549 Command to be run in a shell once for each certificate challenge that
22550 have been answered by the @code{auth-hook}. For this command, the shell
22551 variables available in the @code{auth-hook} script are still available, and
22552 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
22553 of the @code{auth-hook} script.
22555 @item @code{deploy-hook} (default: @code{#f})
22556 Command to be run in a shell once for each successfully issued
22557 certificate. For this command, the shell variable
22558 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
22559 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
22560 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
22561 contain a space-delimited list of renewed certificate domains (for
22562 example, @samp{"example.com www.example.com"}.
22567 For each @code{certificate-configuration}, the certificate is saved to
22568 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
22569 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
22571 @subsection DNS Services
22572 @cindex DNS (domain name system)
22573 @cindex domain name system (DNS)
22575 The @code{(gnu services dns)} module provides services related to the
22576 @dfn{domain name system} (DNS). It provides a server service for hosting
22577 an @emph{authoritative} DNS server for multiple zones, slave or master.
22578 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
22579 caching and forwarding DNS server for the LAN, which uses
22580 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
22582 @subsubheading Knot Service
22584 An example configuration of an authoritative server for two zones, one master
22588 (define-zone-entries example.org.zone
22589 ;; Name TTL Class Type Data
22590 ("@@" "" "IN" "A" "127.0.0.1")
22591 ("@@" "" "IN" "NS" "ns")
22592 ("ns" "" "IN" "A" "127.0.0.1"))
22594 (define master-zone
22595 (knot-zone-configuration
22596 (domain "example.org")
22598 (origin "example.org")
22599 (entries example.org.zone)))))
22602 (knot-zone-configuration
22603 (domain "plop.org")
22604 (dnssec-policy "default")
22605 (master (list "plop-master"))))
22607 (define plop-master
22608 (knot-remote-configuration
22610 (address (list "208.76.58.171"))))
22614 (services (cons* (service knot-service-type
22615 (knot-configuration
22616 (remotes (list plop-master))
22617 (zones (list master-zone slave-zone))))
22622 @deffn {Scheme Variable} knot-service-type
22623 This is the type for the Knot DNS server.
22625 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
22626 zones, that is to say domain names you would buy from a registrar. This server
22627 is not a resolver, meaning that it can only resolve names for which it is
22628 authoritative. This server can be configured to serve zones as a master server
22629 or a slave server as a per-zone basis. Slave zones will get their data from
22630 masters, and will serve it as an authoritative server. From the point of view
22631 of a resolver, there is no difference between master and slave.
22633 The following data types are used to configure the Knot DNS server:
22636 @deftp {Data Type} knot-key-configuration
22637 Data type representing a key.
22638 This type has the following parameters:
22641 @item @code{id} (default: @code{""})
22642 An identifier for other configuration fields to refer to this key. IDs must
22643 be unique and must not be empty.
22645 @item @code{algorithm} (default: @code{#f})
22646 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
22647 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
22648 and @code{'hmac-sha512}.
22650 @item @code{secret} (default: @code{""})
22651 The secret key itself.
22656 @deftp {Data Type} knot-acl-configuration
22657 Data type representing an Access Control List (ACL) configuration.
22658 This type has the following parameters:
22661 @item @code{id} (default: @code{""})
22662 An identifier for ether configuration fields to refer to this key. IDs must be
22663 unique and must not be empty.
22665 @item @code{address} (default: @code{'()})
22666 An ordered list of IP addresses, network subnets, or network ranges represented
22667 with strings. The query must match one of them. Empty value means that
22668 address match is not required.
22670 @item @code{key} (default: @code{'()})
22671 An ordered list of references to keys represented with strings. The string
22672 must match a key ID defined in a @code{knot-key-configuration}. No key means
22673 that a key is not require to match that ACL.
22675 @item @code{action} (default: @code{'()})
22676 An ordered list of actions that are permitted or forbidden by this ACL. Possible
22677 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
22678 and @code{'update}.
22680 @item @code{deny?} (default: @code{#f})
22681 When true, the ACL defines restrictions. Listed actions are forbidden. When
22682 false, listed actions are allowed.
22687 @deftp {Data Type} zone-entry
22688 Data type representing a record entry in a zone file.
22689 This type has the following parameters:
22692 @item @code{name} (default: @code{"@@"})
22693 The name of the record. @code{"@@"} refers to the origin of the zone. Names
22694 are relative to the origin of the zone. For example, in the @code{example.org}
22695 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
22696 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
22697 refers to @code{ns.example.org}.
22699 @item @code{ttl} (default: @code{""})
22700 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
22702 @item @code{class} (default: @code{"IN"})
22703 The class of the record. Knot currently supports only @code{"IN"} and
22704 partially @code{"CH"}.
22706 @item @code{type} (default: @code{"A"})
22707 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
22708 address), NS (Name Server) and MX (Mail eXchange). Many other types are
22711 @item @code{data} (default: @code{""})
22712 The data contained in the record. For instance an IP address associated with
22713 an A record, or a domain name associated with an NS record. Remember that
22714 domain names are relative to the origin unless they end with a dot.
22719 @deftp {Data Type} zone-file
22720 Data type representing the content of a zone file.
22721 This type has the following parameters:
22724 @item @code{entries} (default: @code{'()})
22725 The list of entries. The SOA record is taken care of, so you don't need to
22726 put it in the list of entries. This list should probably contain an entry
22727 for your primary authoritative DNS server. Other than using a list of entries
22728 directly, you can use @code{define-zone-entries} to define a object containing
22729 the list of entries more easily, that you can later pass to the @code{entries}
22730 field of the @code{zone-file}.
22732 @item @code{origin} (default: @code{""})
22733 The name of your zone. This parameter cannot be empty.
22735 @item @code{ns} (default: @code{"ns"})
22736 The domain of your primary authoritative DNS server. The name is relative to
22737 the origin, unless it ends with a dot. It is mandatory that this primary
22738 DNS server corresponds to an NS record in the zone and that it is associated
22739 to an IP address in the list of entries.
22741 @item @code{mail} (default: @code{"hostmaster"})
22742 An email address people can contact you at, as the owner of the zone. This
22743 is translated as @code{<mail>@@<origin>}.
22745 @item @code{serial} (default: @code{1})
22746 The serial number of the zone. As this is used to keep track of changes by
22747 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
22748 Always increment it when you make a change in your zone.
22750 @item @code{refresh} (default: @code{(* 2 24 3600)})
22751 The frequency at which slaves will do a zone transfer. This value is a number
22752 of seconds. It can be computed by multiplications or with
22753 @code{(string->duration)}.
22755 @item @code{retry} (default: @code{(* 15 60)})
22756 The period after which a slave will retry to contact its master when it fails
22757 to do so a first time.
22759 @item @code{expiry} (default: @code{(* 14 24 3600)})
22760 Default TTL of records. Existing records are considered correct for at most
22761 this amount of time. After this period, resolvers will invalidate their cache
22762 and check again that it still exists.
22764 @item @code{nx} (default: @code{3600})
22765 Default TTL of inexistant records. This delay is usually short because you want
22766 your new domains to reach everyone quickly.
22771 @deftp {Data Type} knot-remote-configuration
22772 Data type representing a remote configuration.
22773 This type has the following parameters:
22776 @item @code{id} (default: @code{""})
22777 An identifier for other configuration fields to refer to this remote. IDs must
22778 be unique and must not be empty.
22780 @item @code{address} (default: @code{'()})
22781 An ordered list of destination IP addresses. Addresses are tried in sequence.
22782 An optional port can be given with the @@ separator. For instance:
22783 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
22785 @item @code{via} (default: @code{'()})
22786 An ordered list of source IP addresses. An empty list will have Knot choose
22787 an appropriate source IP. An optional port can be given with the @@ separator.
22788 The default is to choose at random.
22790 @item @code{key} (default: @code{#f})
22791 A reference to a key, that is a string containing the identifier of a key
22792 defined in a @code{knot-key-configuration} field.
22797 @deftp {Data Type} knot-keystore-configuration
22798 Data type representing a keystore to hold dnssec keys.
22799 This type has the following parameters:
22802 @item @code{id} (default: @code{""})
22803 The id of the keystore. It must not be empty.
22805 @item @code{backend} (default: @code{'pem})
22806 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
22808 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
22809 The configuration string of the backend. An example for the PKCS#11 is:
22810 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
22811 For the pem backend, the string represents a path in the file system.
22816 @deftp {Data Type} knot-policy-configuration
22817 Data type representing a dnssec policy. Knot DNS is able to automatically
22818 sign your zones. It can either generate and manage your keys automatically or
22819 use keys that you generate.
22821 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
22822 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
22823 zone. In order to be trusted, the KSK needs to be present in the parent zone
22824 (usually a top-level domain). If your registrar supports dnssec, you will
22825 have to send them your KSK's hash so they can add a DS record in their zone.
22826 This is not automated and need to be done each time you change your KSK.
22828 The policy also defines the lifetime of keys. Usually, ZSK can be changed
22829 easily and use weaker cryptographic functions (they use lower parameters) in
22830 order to sign records quickly, so they are changed often. The KSK however
22831 requires manual interaction with the registrar, so they are changed less often
22832 and use stronger parameters because they sign only one record.
22834 This type has the following parameters:
22837 @item @code{id} (default: @code{""})
22838 The id of the policy. It must not be empty.
22840 @item @code{keystore} (default: @code{"default"})
22841 A reference to a keystore, that is a string containing the identifier of a
22842 keystore defined in a @code{knot-keystore-configuration} field. The
22843 @code{"default"} identifier means the default keystore (a kasp database that
22844 was setup by this service).
22846 @item @code{manual?} (default: @code{#f})
22847 Whether the key management is manual or automatic.
22849 @item @code{single-type-signing?} (default: @code{#f})
22850 When @code{#t}, use the Single-Type Signing Scheme.
22852 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
22853 An algorithm of signing keys and issued signatures.
22855 @item @code{ksk-size} (default: @code{256})
22856 The length of the KSK. Note that this value is correct for the default
22857 algorithm, but would be unsecure for other algorithms.
22859 @item @code{zsk-size} (default: @code{256})
22860 The length of the ZSK. Note that this value is correct for the default
22861 algorithm, but would be unsecure for other algorithms.
22863 @item @code{dnskey-ttl} (default: @code{'default})
22864 The TTL value for DNSKEY records added into zone apex. The special
22865 @code{'default} value means same as the zone SOA TTL.
22867 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
22868 The period between ZSK publication and the next rollover initiation.
22870 @item @code{propagation-delay} (default: @code{(* 24 3600)})
22871 An extra delay added for each key rollover step. This value should be high
22872 enough to cover propagation of data from the master server to all slaves.
22874 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
22875 A validity period of newly issued signatures.
22877 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
22878 A period how long before a signature expiration the signature will be refreshed.
22880 @item @code{nsec3?} (default: @code{#f})
22881 When @code{#t}, NSEC3 will be used instead of NSEC.
22883 @item @code{nsec3-iterations} (default: @code{5})
22884 The number of additional times the hashing is performed.
22886 @item @code{nsec3-salt-length} (default: @code{8})
22887 The length of a salt field in octets, which is appended to the original owner
22888 name before hashing.
22890 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
22891 The validity period of newly issued salt field.
22896 @deftp {Data Type} knot-zone-configuration
22897 Data type representing a zone served by Knot.
22898 This type has the following parameters:
22901 @item @code{domain} (default: @code{""})
22902 The domain served by this configuration. It must not be empty.
22904 @item @code{file} (default: @code{""})
22905 The file where this zone is saved. This parameter is ignored by master zones.
22906 Empty means default location that depends on the domain name.
22908 @item @code{zone} (default: @code{(zone-file)})
22909 The content of the zone file. This parameter is ignored by slave zones. It
22910 must contain a zone-file record.
22912 @item @code{master} (default: @code{'()})
22913 A list of master remotes. When empty, this zone is a master. When set, this
22914 zone is a slave. This is a list of remotes identifiers.
22916 @item @code{ddns-master} (default: @code{#f})
22917 The main master. When empty, it defaults to the first master in the list of
22920 @item @code{notify} (default: @code{'()})
22921 A list of slave remote identifiers.
22923 @item @code{acl} (default: @code{'()})
22924 A list of acl identifiers.
22926 @item @code{semantic-checks?} (default: @code{#f})
22927 When set, this adds more semantic checks to the zone.
22929 @item @code{disable-any?} (default: @code{#f})
22930 When set, this forbids queries of the ANY type.
22932 @item @code{zonefile-sync} (default: @code{0})
22933 The delay between a modification in memory and on disk. 0 means immediate
22936 @item @code{zonefile-load} (default: @code{#f})
22937 The way the zone file contents are applied during zone load. Possible values
22941 @item @code{#f} for using the default value from Knot,
22942 @item @code{'none} for not using the zone file at all,
22943 @item @code{'difference} for computing the difference between already available
22944 contents and zone contents and applying it to the current zone contents,
22945 @item @code{'difference-no-serial} for the same as @code{'difference}, but
22946 ignoring the SOA serial in the zone file, while the server takes care of it
22948 @item @code{'whole} for loading zone contents from the zone file.
22951 @item @code{journal-content} (default: @code{#f})
22952 The way the journal is used to store zone and its changes. Possible values
22953 are @code{'none} to not use it at all, @code{'changes} to store changes and
22954 @code{'all} to store contents. @code{#f} does not set this option, so the
22955 default value from Knot is used.
22957 @item @code{max-journal-usage} (default: @code{#f})
22958 The maximum size for the journal on disk. @code{#f} does not set this option,
22959 so the default value from Knot is used.
22961 @item @code{max-journal-depth} (default: @code{#f})
22962 The maximum size of the history. @code{#f} does not set this option, so the
22963 default value from Knot is used.
22965 @item @code{max-zone-size} (default: @code{#f})
22966 The maximum size of the zone file. This limit is enforced for incoming
22967 transfer and updates. @code{#f} does not set this option, so the default
22968 value from Knot is used.
22970 @item @code{dnssec-policy} (default: @code{#f})
22971 A reference to a @code{knot-policy-configuration} record, or the special
22972 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
22975 @item @code{serial-policy} (default: @code{'increment})
22976 A policy between @code{'increment} and @code{'unixtime}.
22981 @deftp {Data Type} knot-configuration
22982 Data type representing the Knot configuration.
22983 This type has the following parameters:
22986 @item @code{knot} (default: @code{knot})
22989 @item @code{run-directory} (default: @code{"/var/run/knot"})
22990 The run directory. This directory will be used for pid file and sockets.
22992 @item @code{includes} (default: @code{'()})
22993 A list of strings or file-like objects denoting other files that must be
22994 included at the top of the configuration file.
22996 @cindex secrets, Knot service
22997 This can be used to manage secrets out-of-band. For example, secret
22998 keys may be stored in an out-of-band file not managed by Guix, and
22999 thus not visible in @file{/gnu/store}---e.g., you could store secret
23000 key configuration in @file{/etc/knot/secrets.conf} and add this file
23001 to the @code{includes} list.
23003 One can generate a secret tsig key (for nsupdate and zone transfers with the
23004 keymgr command from the knot package. Note that the package is not automatically
23005 installed by the service. The following example shows how to generate a new
23009 keymgr -t mysecret > /etc/knot/secrets.conf
23010 chmod 600 /etc/knot/secrets.conf
23013 Also note that the generated key will be named @var{mysecret}, so it is the
23014 name that needs to be used in the @var{key} field of the
23015 @code{knot-acl-configuration} record and in other places that need to refer
23018 It can also be used to add configuration not supported by this interface.
23020 @item @code{listen-v4} (default: @code{"0.0.0.0"})
23021 An ip address on which to listen.
23023 @item @code{listen-v6} (default: @code{"::"})
23024 An ip address on which to listen.
23026 @item @code{listen-port} (default: @code{53})
23027 A port on which to listen.
23029 @item @code{keys} (default: @code{'()})
23030 The list of knot-key-configuration used by this configuration.
23032 @item @code{acls} (default: @code{'()})
23033 The list of knot-acl-configuration used by this configuration.
23035 @item @code{remotes} (default: @code{'()})
23036 The list of knot-remote-configuration used by this configuration.
23038 @item @code{zones} (default: @code{'()})
23039 The list of knot-zone-configuration used by this configuration.
23044 @subsubheading Knot Resolver Service
23046 @deffn {Scheme Variable} knot-resolver-service-type
23047 This this the type of the knot resolver service, whose value should be
23048 an @code{knot-resolver-configuration} object as in this example:
23051 (service knot-resolver-service-type
23052 (knot-resolver-configuration
23053 (kresd-config-file (plain-file "kresd.conf" "
23054 net.listen('192.168.0.1', 5353)
23055 user('knot-resolver', 'knot-resolver')
23056 modules = @{ 'hints > iterate', 'stats', 'predict' @}
23057 cache.size = 100 * MB
23061 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
23064 @deftp {Data Type} knot-resolver-configuration
23065 Data type representing the configuration of knot-resolver.
23068 @item @code{package} (default: @var{knot-resolver})
23069 Package object of the knot DNS resolver.
23071 @item @code{kresd-config-file} (default: %kresd.conf)
23072 File-like object of the kresd configuration file to use, by default it
23073 will listen on @code{127.0.0.1} and @code{::1}.
23075 @item @code{garbage-collection-interval} (default: 1000)
23076 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
23082 @subsubheading Dnsmasq Service
23084 @deffn {Scheme Variable} dnsmasq-service-type
23085 This is the type of the dnsmasq service, whose value should be an
23086 @code{dnsmasq-configuration} object as in this example:
23089 (service dnsmasq-service-type
23090 (dnsmasq-configuration
23092 (servers '("192.168.1.1"))))
23096 @deftp {Data Type} dnsmasq-configuration
23097 Data type representing the configuration of dnsmasq.
23100 @item @code{package} (default: @var{dnsmasq})
23101 Package object of the dnsmasq server.
23103 @item @code{no-hosts?} (default: @code{#f})
23104 When true, don't read the hostnames in /etc/hosts.
23106 @item @code{port} (default: @code{53})
23107 The port to listen on. Setting this to zero completely disables DNS
23108 responses, leaving only DHCP and/or TFTP functions.
23110 @item @code{local-service?} (default: @code{#t})
23111 Accept DNS queries only from hosts whose address is on a local subnet,
23112 ie a subnet for which an interface exists on the server.
23114 @item @code{listen-addresses} (default: @code{'()})
23115 Listen on the given IP addresses.
23117 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
23118 The file to read the IP address of the upstream nameservers from.
23120 @item @code{no-resolv?} (default: @code{#f})
23121 When true, don't read @var{resolv-file}.
23123 @item @code{servers} (default: @code{'()})
23124 Specify IP address of upstream servers directly.
23126 @item @code{addresses} (default: @code{'()})
23127 For each entry, specify an IP address to return for any host in the
23128 given domains. Queries in the domains are never forwarded and always
23129 replied to with the specified IP address.
23131 This is useful for redirecting hosts locally, for example:
23134 (service dnsmasq-service-type
23135 (dnsmasq-configuration
23137 '(; Redirect to a local web-server.
23138 "/example.org/127.0.0.1"
23139 ; Redirect subdomain to a specific IP.
23140 "/subdomain.example.org/192.168.1.42"))))
23143 Note that rules in @file{/etc/hosts} take precedence over this.
23145 @item @code{cache-size} (default: @code{150})
23146 Set the size of dnsmasq's cache. Setting the cache size to zero
23149 @item @code{negative-cache?} (default: @code{#t})
23150 When false, disable negative caching.
23155 @subsubheading ddclient Service
23158 The ddclient service described below runs the ddclient daemon, which takes
23159 care of automatically updating DNS entries for service providers such as
23160 @uref{https://dyn.com/dns/, Dyn}.
23162 The following example show instantiates the service with its default
23166 (service ddclient-service-type)
23169 Note that ddclient needs to access credentials that are stored in a
23170 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
23171 @code{secret-file} below). You are expected to create this file manually, in
23172 an ``out-of-band'' fashion (you @emph{could} make this file part of the
23173 service configuration, for instance by using @code{plain-file}, but it will be
23174 world-readable @i{via} @file{/gnu/store}). See the examples in the
23175 @file{share/ddclient} directory of the @code{ddclient} package.
23177 @c %start of fragment
23179 Available @code{ddclient-configuration} fields are:
23181 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
23182 The ddclient package.
23186 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
23187 The period after which ddclient will retry to check IP and domain name.
23189 Defaults to @samp{300}.
23193 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
23194 Use syslog for the output.
23196 Defaults to @samp{#t}.
23200 @deftypevr {@code{ddclient-configuration} parameter} string mail
23203 Defaults to @samp{"root"}.
23207 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
23208 Mail failed update to user.
23210 Defaults to @samp{"root"}.
23214 @deftypevr {@code{ddclient-configuration} parameter} string pid
23215 The ddclient PID file.
23217 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
23221 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
23222 Enable SSL support.
23224 Defaults to @samp{#t}.
23228 @deftypevr {@code{ddclient-configuration} parameter} string user
23229 Specifies the user name or ID that is used when running ddclient
23232 Defaults to @samp{"ddclient"}.
23236 @deftypevr {@code{ddclient-configuration} parameter} string group
23237 Group of the user who will run the ddclient program.
23239 Defaults to @samp{"ddclient"}.
23243 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
23244 Secret file which will be appended to @file{ddclient.conf} file. This
23245 file contains credentials for use by ddclient. You are expected to
23246 create it manually.
23248 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
23252 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
23253 Extra options will be appended to @file{ddclient.conf} file.
23255 Defaults to @samp{()}.
23260 @c %end of fragment
23264 @subsection VPN Services
23265 @cindex VPN (virtual private network)
23266 @cindex virtual private network (VPN)
23268 The @code{(gnu services vpn)} module provides services related to
23269 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
23270 your machine to connect to a VPN, and a @emph{server} service for your machine
23271 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
23273 @deffn {Scheme Procedure} openvpn-client-service @
23274 [#:config (openvpn-client-configuration)]
23276 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
23279 @deffn {Scheme Procedure} openvpn-server-service @
23280 [#:config (openvpn-server-configuration)]
23282 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
23284 Both can be run simultaneously.
23287 @c %automatically generated documentation
23289 Available @code{openvpn-client-configuration} fields are:
23291 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
23292 The OpenVPN package.
23296 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
23297 The OpenVPN pid file.
23299 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
23303 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
23304 The protocol (UDP or TCP) used to open a channel between clients and
23307 Defaults to @samp{udp}.
23311 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
23312 The device type used to represent the VPN connection.
23314 Defaults to @samp{tun}.
23318 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
23319 The certificate authority to check connections against.
23321 Defaults to @samp{"/etc/openvpn/ca.crt"}.
23325 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
23326 The certificate of the machine the daemon is running on. It should be
23327 signed by the authority given in @code{ca}.
23329 Defaults to @samp{"/etc/openvpn/client.crt"}.
23333 @deftypevr {@code{openvpn-client-configuration} parameter} string key
23334 The key of the machine the daemon is running on. It must be the key whose
23335 certificate is @code{cert}.
23337 Defaults to @samp{"/etc/openvpn/client.key"}.
23341 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
23342 Whether to use the lzo compression algorithm.
23344 Defaults to @samp{#t}.
23348 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
23349 Don't re-read key files across SIGUSR1 or --ping-restart.
23351 Defaults to @samp{#t}.
23355 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
23356 Don't close and reopen TUN/TAP device or run up/down scripts across
23357 SIGUSR1 or --ping-restart restarts.
23359 Defaults to @samp{#t}.
23363 @deftypevr {@code{openvpn-client-configuration} parameter} boolean fast-io?
23364 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
23365 poll/epoll/select prior to the write operation.
23367 Defaults to @samp{#f}.
23370 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
23373 Defaults to @samp{3}.
23377 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
23378 Add an additional layer of HMAC authentication on top of the TLS control
23379 channel to protect against DoS attacks.
23381 Defaults to @samp{#f}.
23385 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string auth-user-pass
23386 Authenticate with server using username/password. The option is a file
23387 containing username/password on 2 lines. Do not use a file-like object as it
23388 would be added to the store and readable by any user.
23390 Defaults to @samp{'disabled}.
23393 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
23394 Whether to check the server certificate has server usage extension.
23396 Defaults to @samp{#t}.
23400 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
23401 Bind to a specific local port number.
23403 Defaults to @samp{#f}.
23407 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
23408 Retry resolving server address.
23410 Defaults to @samp{#t}.
23414 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
23415 A list of remote servers to connect to.
23417 Defaults to @samp{()}.
23419 Available @code{openvpn-remote-configuration} fields are:
23421 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
23424 Defaults to @samp{"my-server"}.
23428 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
23429 Port number the server listens to.
23431 Defaults to @samp{1194}.
23436 @c %end of automatic openvpn-client documentation
23438 @c %automatically generated documentation
23440 Available @code{openvpn-server-configuration} fields are:
23442 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
23443 The OpenVPN package.
23447 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
23448 The OpenVPN pid file.
23450 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
23454 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
23455 The protocol (UDP or TCP) used to open a channel between clients and
23458 Defaults to @samp{udp}.
23462 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
23463 The device type used to represent the VPN connection.
23465 Defaults to @samp{tun}.
23469 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
23470 The certificate authority to check connections against.
23472 Defaults to @samp{"/etc/openvpn/ca.crt"}.
23476 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
23477 The certificate of the machine the daemon is running on. It should be
23478 signed by the authority given in @code{ca}.
23480 Defaults to @samp{"/etc/openvpn/client.crt"}.
23484 @deftypevr {@code{openvpn-server-configuration} parameter} string key
23485 The key of the machine the daemon is running on. It must be the key whose
23486 certificate is @code{cert}.
23488 Defaults to @samp{"/etc/openvpn/client.key"}.
23492 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
23493 Whether to use the lzo compression algorithm.
23495 Defaults to @samp{#t}.
23499 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
23500 Don't re-read key files across SIGUSR1 or --ping-restart.
23502 Defaults to @samp{#t}.
23506 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
23507 Don't close and reopen TUN/TAP device or run up/down scripts across
23508 SIGUSR1 or --ping-restart restarts.
23510 Defaults to @samp{#t}.
23514 @deftypevr {@code{openvpn-server-configuration} parameter} boolean fast-io?
23515 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
23516 poll/epoll/select prior to the write operation.
23518 Defaults to @samp{#f}.
23521 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
23524 Defaults to @samp{3}.
23528 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
23529 Add an additional layer of HMAC authentication on top of the TLS control
23530 channel to protect against DoS attacks.
23532 Defaults to @samp{#f}.
23536 @deftypevr {@code{openvpn-server-configuration} parameter} number port
23537 Specifies the port number on which the server listens.
23539 Defaults to @samp{1194}.
23543 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
23544 An ip and mask specifying the subnet inside the virtual network.
23546 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
23550 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
23551 A CIDR notation specifying the IPv6 subnet inside the virtual network.
23553 Defaults to @samp{#f}.
23557 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
23558 The Diffie-Hellman parameters file.
23560 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
23564 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
23565 The file that records client IPs.
23567 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
23571 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
23572 When true, the server will act as a gateway for its clients.
23574 Defaults to @samp{#f}.
23578 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
23579 When true, clients are allowed to talk to each other inside the VPN.
23581 Defaults to @samp{#f}.
23585 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
23586 Causes ping-like messages to be sent back and forth over the link so
23587 that each side knows when the other side has gone down. @code{keepalive}
23588 requires a pair. The first element is the period of the ping sending,
23589 and the second element is the timeout before considering the other side
23594 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
23595 The maximum number of clients.
23597 Defaults to @samp{100}.
23601 @deftypevr {@code{openvpn-server-configuration} parameter} string status
23602 The status file. This file shows a small report on current connection.
23603 It is truncated and rewritten every minute.
23605 Defaults to @samp{"/var/run/openvpn/status"}.
23609 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
23610 The list of configuration for some clients.
23612 Defaults to @samp{()}.
23614 Available @code{openvpn-ccd-configuration} fields are:
23616 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
23619 Defaults to @samp{"client"}.
23623 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
23626 Defaults to @samp{#f}.
23630 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
23633 Defaults to @samp{#f}.
23640 @c %end of automatic openvpn-server documentation
23643 @node Network File System
23644 @subsection Network File System
23647 The @code{(gnu services nfs)} module provides the following services,
23648 which are most commonly used in relation to mounting or exporting
23649 directory trees as @dfn{network file systems} (NFS).
23651 While it is possible to use the individual components that together make
23652 up a Network File System service, we recommended to configure an NFS
23653 server with the @code{nfs-service-type}.
23655 @subsubheading NFS Service
23656 @cindex NFS, server
23658 The NFS service takes care of setting up all NFS component services,
23659 kernel configuration file systems, and installs configuration files in
23660 the locations that NFS expects.
23662 @defvr {Scheme Variable} nfs-service-type
23663 A service type for a complete NFS server.
23666 @deftp {Data Type} nfs-configuration
23667 This data type represents the configuration of the NFS service and all
23670 It has the following parameters:
23672 @item @code{nfs-utils} (default: @code{nfs-utils})
23673 The nfs-utils package to use.
23675 @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
23676 If a list of string values is provided, the @command{rpc.nfsd} daemon
23677 will be limited to supporting the given versions of the NFS protocol.
23679 @item @code{exports} (default: @code{'()})
23680 This is a list of directories the NFS server should export. Each entry
23681 is a list consisting of two elements: a directory name and a string
23682 containing all options. This is an example in which the directory
23683 @file{/export} is served to all NFS clients as a read-only share:
23689 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
23692 @item @code{rpcmountd-port} (default: @code{#f})
23693 The network port that the @command{rpc.mountd} daemon should use.
23695 @item @code{rpcstatd-port} (default: @code{#f})
23696 The network port that the @command{rpc.statd} daemon should use.
23698 @item @code{rpcbind} (default: @code{rpcbind})
23699 The rpcbind package to use.
23701 @item @code{idmap-domain} (default: @code{"localdomain"})
23702 The local NFSv4 domain name.
23704 @item @code{nfsd-port} (default: @code{2049})
23705 The network port that the @command{nfsd} daemon should use.
23707 @item @code{nfsd-threads} (default: @code{8})
23708 The number of threads used by the @command{nfsd} daemon.
23710 @item @code{nfsd-tcp?} (default: @code{#t})
23711 Whether the @command{nfsd} daemon should listen on a TCP socket.
23713 @item @code{nfsd-udp?} (default: @code{#f})
23714 Whether the @command{nfsd} daemon should listen on a UDP socket.
23716 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23717 The directory where the pipefs file system is mounted.
23719 @item @code{debug} (default: @code{'()"})
23720 A list of subsystems for which debugging output should be enabled. This
23721 is a list of symbols. Any of these symbols are valid: @code{nfsd},
23722 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
23726 If you don't need a complete NFS service or prefer to build it yourself
23727 you can use the individual component services that are documented below.
23729 @subsubheading RPC Bind Service
23732 The RPC Bind service provides a facility to map program numbers into
23733 universal addresses.
23734 Many NFS related services use this facility. Hence it is automatically
23735 started when a dependent service starts.
23737 @defvr {Scheme Variable} rpcbind-service-type
23738 A service type for the RPC portmapper daemon.
23742 @deftp {Data Type} rpcbind-configuration
23743 Data type representing the configuration of the RPC Bind Service.
23744 This type has the following parameters:
23746 @item @code{rpcbind} (default: @code{rpcbind})
23747 The rpcbind package to use.
23749 @item @code{warm-start?} (default: @code{#t})
23750 If this parameter is @code{#t}, then the daemon will read a
23751 state file on startup thus reloading state information saved by a previous
23757 @subsubheading Pipefs Pseudo File System
23761 The pipefs file system is used to transfer NFS related data
23762 between the kernel and user space programs.
23764 @defvr {Scheme Variable} pipefs-service-type
23765 A service type for the pipefs pseudo file system.
23768 @deftp {Data Type} pipefs-configuration
23769 Data type representing the configuration of the pipefs pseudo file system service.
23770 This type has the following parameters:
23772 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23773 The directory to which the file system is to be attached.
23778 @subsubheading GSS Daemon Service
23781 @cindex global security system
23783 The @dfn{global security system} (GSS) daemon provides strong security for RPC
23785 Before exchanging RPC requests an RPC client must establish a security
23786 context. Typically this is done using the Kerberos command @command{kinit}
23787 or automatically at login time using PAM services (@pxref{Kerberos Services}).
23789 @defvr {Scheme Variable} gss-service-type
23790 A service type for the Global Security System (GSS) daemon.
23793 @deftp {Data Type} gss-configuration
23794 Data type representing the configuration of the GSS daemon service.
23795 This type has the following parameters:
23797 @item @code{nfs-utils} (default: @code{nfs-utils})
23798 The package in which the @command{rpc.gssd} command is to be found.
23800 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23801 The directory where the pipefs file system is mounted.
23807 @subsubheading IDMAP Daemon Service
23809 @cindex name mapper
23811 The idmap daemon service provides mapping between user IDs and user names.
23812 Typically it is required in order to access file systems mounted via NFSv4.
23814 @defvr {Scheme Variable} idmap-service-type
23815 A service type for the Identity Mapper (IDMAP) daemon.
23818 @deftp {Data Type} idmap-configuration
23819 Data type representing the configuration of the IDMAP daemon service.
23820 This type has the following parameters:
23822 @item @code{nfs-utils} (default: @code{nfs-utils})
23823 The package in which the @command{rpc.idmapd} command is to be found.
23825 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23826 The directory where the pipefs file system is mounted.
23828 @item @code{domain} (default: @code{#f})
23829 The local NFSv4 domain name.
23830 This must be a string or @code{#f}.
23831 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
23833 @item @code{verbosity} (default: @code{0})
23834 The verbosity level of the daemon.
23839 @node Continuous Integration
23840 @subsection Continuous Integration
23842 @cindex continuous integration
23843 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
23844 continuous integration tool for Guix. It can be used both for development and
23845 for providing substitutes to others (@pxref{Substitutes}).
23847 The @code{(gnu services cuirass)} module provides the following service.
23849 @defvr {Scheme Procedure} cuirass-service-type
23850 The type of the Cuirass service. Its value must be a
23851 @code{cuirass-configuration} object, as described below.
23854 To add build jobs, you have to set the @code{specifications} field of the
23855 configuration. Here is an example of a service that polls the Guix repository
23856 and builds the packages from a manifest. Some of the packages are defined in
23857 the @code{"custom-packages"} input, which is the equivalent of
23858 @env{GUIX_PACKAGE_PATH}.
23861 (define %cuirass-specs
23863 '((#:name . "my-manifest")
23864 (#:load-path-inputs . ("guix"))
23865 (#:package-path-inputs . ("custom-packages"))
23866 (#:proc-input . "guix")
23867 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
23868 (#:proc . cuirass-jobs)
23869 (#:proc-args . ((subset . "manifests")
23870 (systems . ("x86_64-linux"))
23871 (manifests . (("config" . "guix/manifest.scm")))))
23872 (#:inputs . (((#:name . "guix")
23873 (#:url . "git://git.savannah.gnu.org/guix.git")
23874 (#:load-path . ".")
23875 (#:branch . "master")
23876 (#:no-compile? . #t))
23877 ((#:name . "config")
23878 (#:url . "https://git.example.org/config.git")
23879 (#:load-path . ".")
23880 (#:branch . "master")
23881 (#:no-compile? . #t))
23882 ((#:name . "custom-packages")
23883 (#:url . "https://git.example.org/custom-packages.git")
23884 (#:load-path . ".")
23885 (#:branch . "master")
23886 (#:no-compile? . #t)))))))
23888 (service cuirass-service-type
23889 (cuirass-configuration
23890 (specifications %cuirass-specs)))
23893 While information related to build jobs is located directly in the
23894 specifications, global settings for the @command{cuirass} process are
23895 accessible in other @code{cuirass-configuration} fields.
23897 @deftp {Data Type} cuirass-configuration
23898 Data type representing the configuration of Cuirass.
23901 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
23902 Location of the log file.
23904 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
23905 Location of the log file used by the web interface.
23907 @item @code{queries-log-file} (default: @code{#f})
23908 Location of the SQL queries log file. By default, SQL queries logging is
23911 @item @code{web-queries-log-file} (default: @code{#f})
23912 Location of the web SQL queries log file. By default, web SQL queries
23913 logging is disabled.
23915 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
23916 Location of the repository cache.
23918 @item @code{user} (default: @code{"cuirass"})
23919 Owner of the @code{cuirass} process.
23921 @item @code{group} (default: @code{"cuirass"})
23922 Owner's group of the @code{cuirass} process.
23924 @item @code{interval} (default: @code{60})
23925 Number of seconds between the poll of the repositories followed by the
23928 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
23929 Location of sqlite database which contains the build results and previously
23930 added specifications.
23932 @item @code{ttl} (default: @code{(* 30 24 3600)})
23933 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
23934 are registered for build results. This means that build results are protected
23935 from garbage collection for at least @var{ttl} seconds.
23937 @item @code{port} (default: @code{8081})
23938 Port number used by the HTTP server.
23940 @item @code{host} (default: @code{"localhost"})
23941 Listen on the network interface for @var{host}. The default is to
23942 accept connections from localhost.
23944 @item @code{specifications} (default: @code{#~'()})
23945 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
23946 where a specification is an association list
23947 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
23948 keys are keywords (@code{#:keyword-example}) as shown in the example
23951 @item @code{use-substitutes?} (default: @code{#f})
23952 This allows using substitutes to avoid building every dependencies of a job
23955 @item @code{one-shot?} (default: @code{#f})
23956 Only evaluate specifications and build derivations once.
23958 @item @code{fallback?} (default: @code{#f})
23959 When substituting a pre-built binary fails, fall back to building
23962 @item @code{extra-options} (default: @code{'()})
23963 Extra options to pass when running the Cuirass processes.
23965 @item @code{cuirass} (default: @code{cuirass})
23966 The Cuirass package to use.
23970 @node Power Management Services
23971 @subsection Power Management Services
23974 @cindex power management with TLP
23975 @subsubheading TLP daemon
23977 The @code{(gnu services pm)} module provides a Guix service definition
23978 for the Linux power management tool TLP.
23980 TLP enables various powersaving modes in userspace and kernel.
23981 Contrary to @code{upower-service}, it is not a passive,
23982 monitoring tool, as it will apply custom settings each time a new power
23983 source is detected. More information can be found at
23984 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
23986 @deffn {Scheme Variable} tlp-service-type
23987 The service type for the TLP tool. The default settings are optimised
23988 for battery life on most systems, but you can tweak them to your heart's
23989 content by adding a valid @code{tlp-configuration}:
23991 (service tlp-service-type
23993 (cpu-scaling-governor-on-ac (list "performance"))
23994 (sched-powersave-on-bat? #t)))
23998 Each parameter definition is preceded by its type; for example,
23999 @samp{boolean foo} indicates that the @code{foo} parameter
24000 should be specified as a boolean. Types starting with
24001 @code{maybe-} denote parameters that won't show up in TLP config file
24002 when their value is @code{'disabled}.
24004 @c The following documentation was initially generated by
24005 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
24006 @c documentation is better, so we shouldn't hesitate to edit below as
24007 @c needed. However if the change you want to make to this documentation
24008 @c can be done in an automated way, it's probably easier to change
24009 @c (generate-documentation) than to make it below and have to deal with
24010 @c the churn as TLP updates.
24012 Available @code{tlp-configuration} fields are:
24014 @deftypevr {@code{tlp-configuration} parameter} package tlp
24019 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
24020 Set to true if you wish to enable TLP.
24022 Defaults to @samp{#t}.
24026 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
24027 Default mode when no power supply can be detected. Alternatives are AC
24030 Defaults to @samp{"AC"}.
24034 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
24035 Number of seconds Linux kernel has to wait after the disk goes idle,
24036 before syncing on AC.
24038 Defaults to @samp{0}.
24042 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
24043 Same as @code{disk-idle-ac} but on BAT mode.
24045 Defaults to @samp{2}.
24049 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
24050 Dirty pages flushing periodicity, expressed in seconds.
24052 Defaults to @samp{15}.
24056 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
24057 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
24059 Defaults to @samp{60}.
24063 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
24064 CPU frequency scaling governor on AC mode. With intel_pstate driver,
24065 alternatives are powersave and performance. With acpi-cpufreq driver,
24066 alternatives are ondemand, powersave, performance and conservative.
24068 Defaults to @samp{disabled}.
24072 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
24073 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
24075 Defaults to @samp{disabled}.
24079 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
24080 Set the min available frequency for the scaling governor on AC.
24082 Defaults to @samp{disabled}.
24086 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
24087 Set the max available frequency for the scaling governor on AC.
24089 Defaults to @samp{disabled}.
24093 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
24094 Set the min available frequency for the scaling governor on BAT.
24096 Defaults to @samp{disabled}.
24100 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
24101 Set the max available frequency for the scaling governor on BAT.
24103 Defaults to @samp{disabled}.
24107 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
24108 Limit the min P-state to control the power dissipation of the CPU, in AC
24109 mode. Values are stated as a percentage of the available performance.
24111 Defaults to @samp{disabled}.
24115 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
24116 Limit the max P-state to control the power dissipation of the CPU, in AC
24117 mode. Values are stated as a percentage of the available performance.
24119 Defaults to @samp{disabled}.
24123 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
24124 Same as @code{cpu-min-perf-on-ac} on BAT mode.
24126 Defaults to @samp{disabled}.
24130 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
24131 Same as @code{cpu-max-perf-on-ac} on BAT mode.
24133 Defaults to @samp{disabled}.
24137 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
24138 Enable CPU turbo boost feature on AC mode.
24140 Defaults to @samp{disabled}.
24144 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
24145 Same as @code{cpu-boost-on-ac?} on BAT mode.
24147 Defaults to @samp{disabled}.
24151 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
24152 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
24153 used under light load conditions.
24155 Defaults to @samp{#f}.
24159 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
24160 Same as @code{sched-powersave-on-ac?} but on BAT mode.
24162 Defaults to @samp{#t}.
24166 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
24167 Enable Linux kernel NMI watchdog.
24169 Defaults to @samp{#f}.
24173 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
24174 For Linux kernels with PHC patch applied, change CPU voltages. An
24175 example value would be @samp{"F:V F:V F:V F:V"}.
24177 Defaults to @samp{disabled}.
24181 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
24182 Set CPU performance versus energy saving policy on AC. Alternatives are
24183 performance, normal, powersave.
24185 Defaults to @samp{"performance"}.
24189 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
24190 Same as @code{energy-perf-policy-ac} but on BAT mode.
24192 Defaults to @samp{"powersave"}.
24196 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
24201 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
24202 Hard disk advanced power management level.
24206 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
24207 Same as @code{disk-apm-bat} but on BAT mode.
24211 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
24212 Hard disk spin down timeout. One value has to be specified for each
24213 declared hard disk.
24215 Defaults to @samp{disabled}.
24219 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
24220 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
24222 Defaults to @samp{disabled}.
24226 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
24227 Select IO scheduler for disk devices. One value has to be specified for
24228 each declared hard disk. Example alternatives are cfq, deadline and
24231 Defaults to @samp{disabled}.
24235 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
24236 SATA aggressive link power management (ALPM) level. Alternatives are
24237 min_power, medium_power, max_performance.
24239 Defaults to @samp{"max_performance"}.
24243 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
24244 Same as @code{sata-linkpwr-ac} but on BAT mode.
24246 Defaults to @samp{"min_power"}.
24250 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
24251 Exclude specified SATA host devices for link power management.
24253 Defaults to @samp{disabled}.
24257 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
24258 Enable Runtime Power Management for AHCI controller and disks on AC
24261 Defaults to @samp{disabled}.
24265 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
24266 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
24268 Defaults to @samp{disabled}.
24272 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
24273 Seconds of inactivity before disk is suspended.
24275 Defaults to @samp{15}.
24279 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
24280 PCI Express Active State Power Management level. Alternatives are
24281 default, performance, powersave.
24283 Defaults to @samp{"performance"}.
24287 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
24288 Same as @code{pcie-aspm-ac} but on BAT mode.
24290 Defaults to @samp{"powersave"}.
24294 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
24295 Radeon graphics clock speed level. Alternatives are low, mid, high,
24298 Defaults to @samp{"high"}.
24302 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
24303 Same as @code{radeon-power-ac} but on BAT mode.
24305 Defaults to @samp{"low"}.
24309 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
24310 Radeon dynamic power management method (DPM). Alternatives are battery,
24313 Defaults to @samp{"performance"}.
24317 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
24318 Same as @code{radeon-dpm-state-ac} but on BAT mode.
24320 Defaults to @samp{"battery"}.
24324 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
24325 Radeon DPM performance level. Alternatives are auto, low, high.
24327 Defaults to @samp{"auto"}.
24331 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
24332 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
24334 Defaults to @samp{"auto"}.
24338 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
24339 Wifi power saving mode.
24341 Defaults to @samp{#f}.
24345 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
24346 Same as @code{wifi-power-ac?} but on BAT mode.
24348 Defaults to @samp{#t}.
24352 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
24353 Disable wake on LAN.
24355 Defaults to @samp{#t}.
24359 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
24360 Timeout duration in seconds before activating audio power saving on
24361 Intel HDA and AC97 devices. A value of 0 disables power saving.
24363 Defaults to @samp{0}.
24367 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
24368 Same as @code{sound-powersave-ac} but on BAT mode.
24370 Defaults to @samp{1}.
24374 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
24375 Disable controller in powersaving mode on Intel HDA devices.
24377 Defaults to @samp{#t}.
24381 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
24382 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
24383 powered on again by releasing (and reinserting) the eject lever or by
24384 pressing the disc eject button on newer models.
24386 Defaults to @samp{#f}.
24390 @deftypevr {@code{tlp-configuration} parameter} string bay-device
24391 Name of the optical drive device to power off.
24393 Defaults to @samp{"sr0"}.
24397 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
24398 Runtime Power Management for PCI(e) bus devices. Alternatives are on
24401 Defaults to @samp{"on"}.
24405 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
24406 Same as @code{runtime-pm-ac} but on BAT mode.
24408 Defaults to @samp{"auto"}.
24412 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
24413 Runtime Power Management for all PCI(e) bus devices, except blacklisted
24416 Defaults to @samp{#t}.
24420 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
24421 Exclude specified PCI(e) device addresses from Runtime Power Management.
24423 Defaults to @samp{disabled}.
24427 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
24428 Exclude PCI(e) devices assigned to the specified drivers from Runtime
24433 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
24434 Enable USB autosuspend feature.
24436 Defaults to @samp{#t}.
24440 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
24441 Exclude specified devices from USB autosuspend.
24443 Defaults to @samp{disabled}.
24447 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
24448 Exclude WWAN devices from USB autosuspend.
24450 Defaults to @samp{#t}.
24454 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
24455 Include specified devices into USB autosuspend, even if they are already
24456 excluded by the driver or via @code{usb-blacklist-wwan?}.
24458 Defaults to @samp{disabled}.
24462 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
24463 Enable USB autosuspend before shutdown.
24465 Defaults to @samp{disabled}.
24469 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
24470 Restore radio device state (bluetooth, wifi, wwan) from previous
24471 shutdown on system startup.
24473 Defaults to @samp{#f}.
24478 @cindex CPU frequency scaling with thermald
24479 @subsubheading Thermald daemon
24481 The @code{(gnu services pm)} module provides an interface to
24482 thermald, a CPU frequency scaling service which helps prevent overheating.
24484 @defvr {Scheme Variable} thermald-service-type
24485 This is the service type for
24486 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
24487 Thermal Daemon, which is responsible for controlling the thermal state
24488 of processors and preventing overheating.
24491 @deftp {Data Type} thermald-configuration
24492 Data type representing the configuration of @code{thermald-service-type}.
24495 @item @code{ignore-cpuid-check?} (default: @code{#f})
24496 Ignore cpuid check for supported CPU models.
24498 @item @code{thermald} (default: @var{thermald})
24499 Package object of thermald.
24504 @node Audio Services
24505 @subsection Audio Services
24507 The @code{(gnu services audio)} module provides a service to start MPD
24508 (the Music Player Daemon).
24511 @subsubheading Music Player Daemon
24513 The Music Player Daemon (MPD) is a service that can play music while
24514 being controlled from the local machine or over the network by a variety
24517 The following example shows how one might run @code{mpd} as user
24518 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
24521 (service mpd-service-type
24527 @defvr {Scheme Variable} mpd-service-type
24528 The service type for @command{mpd}
24531 @deftp {Data Type} mpd-configuration
24532 Data type representing the configuration of @command{mpd}.
24535 @item @code{user} (default: @code{"mpd"})
24536 The user to run mpd as.
24538 @item @code{music-dir} (default: @code{"~/Music"})
24539 The directory to scan for music files.
24541 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
24542 The directory to store playlists.
24544 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
24545 The location of the music database.
24547 @item @code{state-file} (default: @code{"~/.mpd/state"})
24548 The location of the file that stores current MPD's state.
24550 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
24551 The location of the sticker database.
24553 @item @code{port} (default: @code{"6600"})
24554 The port to run mpd on.
24556 @item @code{address} (default: @code{"any"})
24557 The address that mpd will bind to. To use a Unix domain socket,
24558 an absolute path can be specified here.
24560 @item @code{outputs} (default: @code{"(list (mpd-output))"})
24561 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
24566 @deftp {Data Type} mpd-output
24567 Data type representing an @command{mpd} audio output.
24570 @item @code{name} (default: @code{"MPD"})
24571 The name of the audio output.
24573 @item @code{type} (default: @code{"pulse"})
24574 The type of audio output.
24576 @item @code{enabled?} (default: @code{#t})
24577 Specifies whether this audio output is enabled when MPD is started. By
24578 default, all audio outputs are enabled. This is just the default
24579 setting when there is no state file; with a state file, the previous
24582 @item @code{tags?} (default: @code{#t})
24583 If set to @code{#f}, then MPD will not send tags to this output. This
24584 is only useful for output plugins that can receive tags, for example the
24585 @code{httpd} output plugin.
24587 @item @code{always-on?} (default: @code{#f})
24588 If set to @code{#t}, then MPD attempts to keep this audio output always
24589 open. This may be useful for streaming servers, when you don’t want to
24590 disconnect all listeners even when playback is accidentally stopped.
24592 @item @code{mixer-type}
24593 This field accepts a symbol that specifies which mixer should be used
24594 for this audio output: the @code{hardware} mixer, the @code{software}
24595 mixer, the @code{null} mixer (allows setting the volume, but with no
24596 effect; this can be used as a trick to implement an external mixer
24597 External Mixer) or no mixer (@code{none}).
24599 @item @code{extra-options} (default: @code{'()"})
24600 An association list of option symbols to string values to be appended to
24601 the audio output configuration.
24606 The following example shows a configuration of @code{mpd} that provides
24607 an HTTP audio streaming output.
24610 (service mpd-service-type
24618 `((encoder . "vorbis")
24619 (port . "8080"))))))))
24623 @node Virtualization Services
24624 @subsection Virtualization services
24626 The @code{(gnu services virtualization)} module provides services for
24627 the libvirt and virtlog daemons, as well as other virtualization-related
24630 @subsubheading Libvirt daemon
24631 @code{libvirtd} is the server side daemon component of the libvirt
24632 virtualization management system. This daemon runs on host servers
24633 and performs required management tasks for virtualized guests.
24635 @deffn {Scheme Variable} libvirt-service-type
24636 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
24637 Its value must be a @code{libvirt-configuration}.
24640 (service libvirt-service-type
24641 (libvirt-configuration
24642 (unix-sock-group "libvirt")
24643 (tls-port "16555")))
24647 @c Auto-generated with (generate-libvirt-documentation)
24648 Available @code{libvirt-configuration} fields are:
24650 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
24655 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
24656 Flag listening for secure TLS connections on the public TCP/IP port.
24657 must set @code{listen} for this to have any effect.
24659 It is necessary to setup a CA and issue server certificates before using
24662 Defaults to @samp{#t}.
24666 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
24667 Listen for unencrypted TCP connections on the public TCP/IP port. must
24668 set @code{listen} for this to have any effect.
24670 Using the TCP socket requires SASL authentication by default. Only SASL
24671 mechanisms which support data encryption are allowed. This is
24672 DIGEST_MD5 and GSSAPI (Kerberos5)
24674 Defaults to @samp{#f}.
24678 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
24679 Port for accepting secure TLS connections This can be a port number, or
24682 Defaults to @samp{"16514"}.
24686 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
24687 Port for accepting insecure TCP connections This can be a port number,
24690 Defaults to @samp{"16509"}.
24694 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
24695 IP address or hostname used for client connections.
24697 Defaults to @samp{"0.0.0.0"}.
24701 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
24702 Flag toggling mDNS advertisement of the libvirt service.
24704 Alternatively can disable for all services on a host by stopping the
24707 Defaults to @samp{#f}.
24711 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
24712 Default mDNS advertisement name. This must be unique on the immediate
24715 Defaults to @samp{"Virtualization Host <hostname>"}.
24719 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
24720 UNIX domain socket group ownership. This can be used to allow a
24721 'trusted' set of users access to management capabilities without
24724 Defaults to @samp{"root"}.
24728 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
24729 UNIX socket permissions for the R/O socket. This is used for monitoring
24732 Defaults to @samp{"0777"}.
24736 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
24737 UNIX socket permissions for the R/W socket. Default allows only root.
24738 If PolicyKit is enabled on the socket, the default will change to allow
24739 everyone (eg, 0777)
24741 Defaults to @samp{"0770"}.
24745 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
24746 UNIX socket permissions for the admin socket. Default allows only owner
24747 (root), do not change it unless you are sure to whom you are exposing
24750 Defaults to @samp{"0777"}.
24754 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
24755 The directory in which sockets will be found/created.
24757 Defaults to @samp{"/var/run/libvirt"}.
24761 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
24762 Authentication scheme for UNIX read-only sockets. By default socket
24763 permissions allow anyone to connect
24765 Defaults to @samp{"polkit"}.
24769 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
24770 Authentication scheme for UNIX read-write sockets. By default socket
24771 permissions only allow root. If PolicyKit support was compiled into
24772 libvirt, the default will be to use 'polkit' auth.
24774 Defaults to @samp{"polkit"}.
24778 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
24779 Authentication scheme for TCP sockets. If you don't enable SASL, then
24780 all TCP traffic is cleartext. Don't do this outside of a dev/test
24783 Defaults to @samp{"sasl"}.
24787 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
24788 Authentication scheme for TLS sockets. TLS sockets already have
24789 encryption provided by the TLS layer, and limited authentication is done
24792 It is possible to make use of any SASL authentication mechanism as well,
24793 by using 'sasl' for this option
24795 Defaults to @samp{"none"}.
24799 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
24800 API access control scheme.
24802 By default an authenticated user is allowed access to all APIs. Access
24803 drivers can place restrictions on this.
24805 Defaults to @samp{()}.
24809 @deftypevr {@code{libvirt-configuration} parameter} string key-file
24810 Server key file path. If set to an empty string, then no private key is
24813 Defaults to @samp{""}.
24817 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
24818 Server key file path. If set to an empty string, then no certificate is
24821 Defaults to @samp{""}.
24825 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
24826 Server key file path. If set to an empty string, then no CA certificate
24829 Defaults to @samp{""}.
24833 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
24834 Certificate revocation list path. If set to an empty string, then no
24837 Defaults to @samp{""}.
24841 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
24842 Disable verification of our own server certificates.
24844 When libvirtd starts it performs some sanity checks against its own
24847 Defaults to @samp{#f}.
24851 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
24852 Disable verification of client certificates.
24854 Client certificate verification is the primary authentication mechanism.
24855 Any client which does not present a certificate signed by the CA will be
24858 Defaults to @samp{#f}.
24862 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
24863 Whitelist of allowed x509 Distinguished Name.
24865 Defaults to @samp{()}.
24869 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
24870 Whitelist of allowed SASL usernames. The format for username depends on
24871 the SASL authentication mechanism.
24873 Defaults to @samp{()}.
24877 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
24878 Override the compile time default TLS priority string. The default is
24879 usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
24880 is desired for libvirt to deviate from the global default settings.
24882 Defaults to @samp{"NORMAL"}.
24886 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
24887 Maximum number of concurrent client connections to allow over all
24890 Defaults to @samp{5000}.
24894 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
24895 Maximum length of queue of connections waiting to be accepted by the
24896 daemon. Note, that some protocols supporting retransmission may obey
24897 this so that a later reattempt at connection succeeds.
24899 Defaults to @samp{1000}.
24903 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
24904 Maximum length of queue of accepted but not yet authenticated clients.
24905 Set this to zero to turn this feature off
24907 Defaults to @samp{20}.
24911 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
24912 Number of workers to start up initially.
24914 Defaults to @samp{5}.
24918 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
24919 Maximum number of worker threads.
24921 If the number of active clients exceeds @code{min-workers}, then more
24922 threads are spawned, up to max_workers limit. Typically you'd want
24923 max_workers to equal maximum number of clients allowed.
24925 Defaults to @samp{20}.
24929 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
24930 Number of priority workers. If all workers from above pool are stuck,
24931 some calls marked as high priority (notably domainDestroy) can be
24932 executed in this pool.
24934 Defaults to @samp{5}.
24938 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
24939 Total global limit on concurrent RPC calls.
24941 Defaults to @samp{20}.
24945 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
24946 Limit on concurrent requests from a single client connection. To avoid
24947 one client monopolizing the server this should be a small fraction of
24948 the global max_requests and max_workers parameter.
24950 Defaults to @samp{5}.
24954 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
24955 Same as @code{min-workers} but for the admin interface.
24957 Defaults to @samp{1}.
24961 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
24962 Same as @code{max-workers} but for the admin interface.
24964 Defaults to @samp{5}.
24968 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
24969 Same as @code{max-clients} but for the admin interface.
24971 Defaults to @samp{5}.
24975 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
24976 Same as @code{max-queued-clients} but for the admin interface.
24978 Defaults to @samp{5}.
24982 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
24983 Same as @code{max-client-requests} but for the admin interface.
24985 Defaults to @samp{5}.
24989 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
24990 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
24992 Defaults to @samp{3}.
24996 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
24999 A filter allows to select a different logging level for a given category
25000 of logs The format for a filter is one of:
25011 where @code{name} is a string which is matched against the category
25012 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
25013 file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
25014 name in the filter can be a substring of the full category name, in
25015 order to match multiple similar categories), the optional @samp{"+"}
25016 prefix tells libvirt to log stack trace for each message matching name,
25017 and @code{x} is the minimal level where matching messages should be
25035 Multiple filters can be defined in a single filters statement, they just
25036 need to be separated by spaces.
25038 Defaults to @samp{"3:remote 4:event"}.
25042 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
25045 An output is one of the places to save logging information. The format
25046 for an output can be:
25050 output goes to stderr
25052 @item x:syslog:name
25053 use syslog for the output and use the given name as the ident
25055 @item x:file:file_path
25056 output to a file, with the given filepath
25059 output to journald logging system
25063 In all case the x prefix is the minimal level, acting as a filter
25080 Multiple outputs can be defined, they just need to be separated by
25083 Defaults to @samp{"3:stderr"}.
25087 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
25088 Allows usage of the auditing subsystem to be altered
25092 0: disable all auditing
25095 1: enable auditing, only if enabled on host
25098 2: enable auditing, and exit if disabled on host.
25102 Defaults to @samp{1}.
25106 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
25107 Send audit messages via libvirt logging infrastructure.
25109 Defaults to @samp{#f}.
25113 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
25114 Host UUID. UUID must not have all digits be the same.
25116 Defaults to @samp{""}.
25120 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
25121 Source to read host UUID.
25125 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
25128 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
25132 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
25135 Defaults to @samp{"smbios"}.
25139 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
25140 A keepalive message is sent to a client after @code{keepalive_interval}
25141 seconds of inactivity to check if the client is still responding. If
25142 set to -1, libvirtd will never send keepalive requests; however clients
25143 can still send them and the daemon will send responses.
25145 Defaults to @samp{5}.
25149 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
25150 Maximum number of keepalive messages that are allowed to be sent to the
25151 client without getting any response before the connection is considered
25154 In other words, the connection is automatically closed approximately
25155 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
25156 the last message received from the client. When @code{keepalive-count}
25157 is set to 0, connections will be automatically closed after
25158 @code{keepalive-interval} seconds of inactivity without sending any
25159 keepalive messages.
25161 Defaults to @samp{5}.
25165 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
25166 Same as above but for admin interface.
25168 Defaults to @samp{5}.
25172 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
25173 Same as above but for admin interface.
25175 Defaults to @samp{5}.
25179 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
25180 Timeout for Open vSwitch calls.
25182 The @code{ovs-vsctl} utility is used for the configuration and its
25183 timeout option is set by default to 5 seconds to avoid potential
25184 infinite waits blocking libvirt.
25186 Defaults to @samp{5}.
25190 @c %end of autogenerated docs
25192 @subsubheading Virtlog daemon
25193 The virtlogd service is a server side daemon component of libvirt that is
25194 used to manage logs from virtual machine consoles.
25196 This daemon is not used directly by libvirt client applications, rather it
25197 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
25198 standalone daemon, the main @code{libvirtd} daemon can be restarted without
25199 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
25200 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
25202 @deffn {Scheme Variable} virtlog-service-type
25203 This is the type of the virtlog daemon.
25204 Its value must be a @code{virtlog-configuration}.
25207 (service virtlog-service-type
25208 (virtlog-configuration
25209 (max-clients 1000)))
25213 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
25214 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
25216 Defaults to @samp{3}.
25220 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
25223 A filter allows to select a different logging level for a given category
25224 of logs The format for a filter is one of:
25235 where @code{name} is a string which is matched against the category
25236 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
25237 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
25238 be a substring of the full category name, in order to match multiple
25239 similar categories), the optional "+" prefix tells libvirt to log stack
25240 trace for each message matching name, and @code{x} is the minimal level
25241 where matching messages should be logged:
25258 Multiple filters can be defined in a single filters statement, they just
25259 need to be separated by spaces.
25261 Defaults to @samp{"3:remote 4:event"}.
25265 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
25268 An output is one of the places to save logging information The format
25269 for an output can be:
25273 output goes to stderr
25275 @item x:syslog:name
25276 use syslog for the output and use the given name as the ident
25278 @item x:file:file_path
25279 output to a file, with the given filepath
25282 output to journald logging system
25286 In all case the x prefix is the minimal level, acting as a filter
25303 Multiple outputs can be defined, they just need to be separated by
25306 Defaults to @samp{"3:stderr"}.
25310 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
25311 Maximum number of concurrent client connections to allow over all
25314 Defaults to @samp{1024}.
25318 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
25319 Maximum file size before rolling over.
25321 Defaults to @samp{2MB}
25325 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
25326 Maximum number of backup files to keep.
25328 Defaults to @samp{3}
25331 @node Transparent Emulation with QEMU
25332 @subsubheading Transparent Emulation with QEMU
25335 @cindex @code{binfmt_misc}
25336 @code{qemu-binfmt-service-type} provides support for transparent
25337 emulation of program binaries built for different architectures---e.g.,
25338 it allows you to transparently execute an ARMv7 program on an x86_64
25339 machine. It achieves this by combining the @uref{https://www.qemu.org,
25340 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
25342 @defvr {Scheme Variable} qemu-binfmt-service-type
25343 This is the type of the QEMU/binfmt service for transparent emulation.
25344 Its value must be a @code{qemu-binfmt-configuration} object, which
25345 specifies the QEMU package to use as well as the architecture we want to
25349 (service qemu-binfmt-service-type
25350 (qemu-binfmt-configuration
25351 (platforms (lookup-qemu-platforms "arm" "aarch64"))))
25354 In this example, we enable transparent emulation for the ARM and aarch64
25355 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
25356 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
25357 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
25360 @deftp {Data Type} qemu-binfmt-configuration
25361 This is the configuration for the @code{qemu-binfmt} service.
25364 @item @code{platforms} (default: @code{'()})
25365 The list of emulated QEMU platforms. Each item must be a @dfn{platform
25366 object} as returned by @code{lookup-qemu-platforms} (see below).
25368 @item @code{guix-support?} (default: @code{#f})
25369 When it is true, QEMU and all its dependencies are added to the build
25370 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
25371 @option{--chroot-directory} option}). This allows the @code{binfmt_misc}
25372 handlers to be used within the build environment, which in turn means
25373 that you can transparently build programs for another architecture.
25375 For example, let's suppose you're on an x86_64 machine and you have this
25379 (service qemu-binfmt-service-type
25380 (qemu-binfmt-configuration
25381 (platforms (lookup-qemu-platforms "arm"))
25382 (guix-support? #t)))
25388 guix build -s armhf-linux inkscape
25392 and it will build Inkscape for ARMv7 @emph{as if it were a native
25393 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
25394 if you'd like to test a package build for an architecture you don't have
25397 @item @code{qemu} (default: @code{qemu})
25398 The QEMU package to use.
25402 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
25403 Return the list of QEMU platform objects corresponding to
25404 @var{platforms}@dots{}. @var{platforms} must be a list of strings
25405 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
25406 @code{"mips64el"}, and so on.
25409 @deffn {Scheme Procedure} qemu-platform? @var{obj}
25410 Return true if @var{obj} is a platform object.
25413 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
25414 Return the name of @var{platform}---a string such as @code{"arm"}.
25418 @subsubheading The Hurd in a Virtual Machine
25420 @cindex @code{hurd}
25424 Service @code{hurd-vm} provides support for running GNU/Hurd in a
25425 virtual machine (VM), a so-called ``Childhurd''. The virtual machine is
25426 a Shepherd service that can be referred to by the names @code{hurd-vm}
25427 and @code{childhurd} and be controlled with commands such as:
25431 herd stop childhurd
25434 The given GNU/Hurd operating system configuration is cross-compiled.
25436 @defvr {Scheme Variable} hurd-vm-service-type
25437 This is the type of the Hurd in a Virtual Machine service. Its value
25438 must be a @code{hurd-vm-configuration} object, which specifies the
25439 operating system (@pxref{operating-system Reference}) and the disk size
25440 for the Hurd Virtual Machine, the QEMU package to use as well as the
25441 options for running it.
25446 (service hurd-vm-service-type
25447 (hurd-vm-configuration
25448 (disk-size (* 5000 (expt 2 20))) ;5G
25449 (memory-size 1024))) ;1024MiB
25452 would create a disk image big enough to build GNU@tie{}Hello, with some
25456 @deftp {Data Type} hurd-vm-configuration
25457 The data type representing the configuration for
25458 @code{hurd-vm-service-type}.
25461 @item @code{os} (default: @var{%hurd-vm-operating-system})
25462 The operating system to instantiate. This default is bare-bones with a
25463 permissive OpenSSH secure shell daemon listening on port 2222
25464 (@pxref{Networking Services, @code{openssh-service-type}}).
25466 @item @code{qemu} (default: @code{qemu-minimal})
25467 The QEMU package to use.
25469 @item @code{image} (default: @var{hurd-vm-disk-image})
25470 The procedure used to build the disk-image built from this
25473 @item @code{disk-size} (default: @code{'guess})
25474 The size of the disk image.
25476 @item @code{memory-size} (default: @code{512})
25477 The memory size of the Virtual Machine in mebibytes.
25479 @item @code{options} (default: @code{'("--snapshot")})
25480 The extra options for running QEMU.
25482 @item @code{id} (default: @code{#f})
25483 If set, a non-zero positive integer used to parameterize Childhurd
25484 instances. It is appended to the service's name,
25485 e.g. @code{childhurd1}.
25487 @item @code{net-options} (default: @var{hurd-vm-net-options})
25488 The procedure used to produce the list of QEMU networking options.
25490 By default, it produces
25493 '("--device" "rtl8139,netdev=net0"
25494 "--netdev" "user,id=net0\
25495 ,hostfwd=tcp:127.0.0.1:<secrets-port>-:1004\
25496 ,hostfwd=tcp:127.0.0.1:<ssh-port>-:2222\
25497 ,hostfwd=tcp:127.0.0.1:<vnc-port>-:5900")
25499 with forwarded ports
25501 <ssh-port>: @code{(+ 11004 (* 1000 @var{ID}))}
25502 <ssh-port>: @code{(+ 10022 (* 1000 @var{ID}))}
25503 <vnc-port>: @code{(+ 15900 (* 1000 @var{ID}))}
25506 @item @code{secret-root} (default: @file{/etc/childhurd})
25507 The root directory with out-of-band secrets to be installed into the
25508 childhurd once it runs. Childhurds are volatile which means that on
25509 every startup, secrets such as the SSH host keys and Guix signing key
25512 If the @file{/etc/childhurd} directory does not exist, the
25513 @code{secret-service} running in the Childhurd will be sent an empty
25516 Typical use to populate @file{"/etc/childhurd"} with a tree of
25517 non-volatile secrets, like so
25520 /etc/childhurd/etc/guix/signing-key.pub
25521 /etc/childhurd/etc/guix/signing-key.sec
25522 /etc/childhurd/etc/ssh/ssh_host_ed25519_key
25523 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key
25524 /etc/childhurd/etc/ssh/ssh_host_ed25519_key.pub
25525 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key.pub
25528 to be sent to the Childhurd, including permissions.
25533 Note that by default the VM image is volatile, i.e., once stopped the
25534 contents are lost. If you want a stateful image instead, override the
25535 configuration's @code{image} and @code{options} without
25536 the @code{--snapshot} flag using something along these lines:
25539 (service hurd-vm-service-type
25540 (hurd-vm-configuration
25541 (image (const "/out/of/store/writable/hurd.img"))
25542 (options '("--hda"))))
25545 @subsubheading Ganeti
25550 This service is considered experimental. Configuration options may be changed
25551 in a backwards-incompatible manner, and not all features have been thorougly
25552 tested. Users of this service are encouraged to share their experience at
25553 @email{guix-devel@@gnu.org}.
25556 Ganeti is a virtual machine management system. It is designed to keep virtual
25557 machines running on a cluster of servers even in the event of hardware failures,
25558 and to make maintenance and recovery tasks easy. It consists of multiple
25559 services which are described later in this section. In addition to the Ganeti
25560 service, you will need the OpenSSH service (@pxref{Networking Services,
25561 @code{openssh-service-type}}), and update the @file{/etc/hosts} file
25562 (@pxref{operating-system Reference, @code{hosts-file}}) with the cluster name
25563 and address (or use a DNS server).
25565 All nodes participating in a Ganeti cluster should have the same Ganeti and
25566 @file{/etc/hosts} configuration. Here is an example configuration for a Ganeti
25567 cluster node that supports multiple storage backends, and installs the
25568 @code{debootstrap} and @code{guix} @dfn{OS providers}:
25571 (use-package-modules virtualization)
25572 (use-service-modules base ganeti networking ssh)
25575 (host-name "node1")
25576 (hosts-file (plain-file "hosts" (format #f "
25577 127.0.0.1 localhost
25580 192.168.1.200 ganeti.example.com
25581 192.168.1.201 node1.example.com node1
25582 192.168.1.202 node2.example.com node2
25585 ;; Install QEMU so we can use KVM-based instances, and LVM, DRBD and Ceph
25586 ;; in order to use the "plain", "drbd" and "rbd" storage backends.
25587 (packages (append (map specification->package
25588 '("qemu" "lvm2" "drbd-utils" "ceph"
25589 ;; Add the debootstrap and guix OS providers.
25590 "ganeti-instance-guix" "ganeti-instance-debootstrap"))
25593 (append (list (static-networking-service "eth0" "192.168.1.201"
25594 #:netmask "255.255.255.0"
25595 #:gateway "192.168.1.254"
25596 #:name-servers '("192.168.1.252"
25599 ;; Ganeti uses SSH to communicate between nodes.
25600 (service openssh-service-type
25601 (openssh-configuration
25602 (permit-root-login 'without-password)))
25604 (service ganeti-service-type
25605 (ganeti-configuration
25606 ;; This list specifies allowed file system paths
25607 ;; for storing virtual machine images.
25608 (file-storage-paths '("/srv/ganeti/file-storage"))
25609 ;; This variable configures a single "variant" for
25610 ;; both Debootstrap and Guix that works with KVM.
25611 (os %default-ganeti-os))))
25615 Users are advised to read the
25616 @url{http://docs.ganeti.org/ganeti/master/html/admin.html,Ganeti
25617 administrators guide} to learn about the various cluster options and
25618 day-to-day operations. There is also a
25619 @url{https://guix.gnu.org/blog/2020/running-a-ganeti-cluster-on-guix/,blog post}
25620 describing how to configure and initialize a small cluster.
25622 @defvr {Scheme Variable} ganeti-service-type
25623 This is a service type that includes all the various services that Ganeti
25626 Its value is a @code{ganeti-configuration} object that defines the package
25627 to use for CLI operations, as well as configuration for the various daemons.
25628 Allowed file storage paths and available guest operating systems are also
25629 configured through this data type.
25632 @deftp {Data Type} ganeti-configuration
25633 The @code{ganeti} service takes the following configuration options:
25636 @item @code{ganeti} (default: @code{ganeti})
25637 The @code{ganeti} package to use. It will be installed to the system profile
25638 and make @command{gnt-cluster}, @command{gnt-instance}, etc available. Note
25639 that the value specified here does not affect the other services as each refer
25640 to a specific @code{ganeti} package (see below).
25642 @item @code{noded-configuration} (default: @code{(ganeti-noded-configuration)})
25643 @itemx @code{confd-configuration} (default: @code{(ganeti-confd-configuration)})
25644 @itemx @code{wconfd-configuration} (default: @code{(ganeti-wconfd-configuration)})
25645 @itemx @code{luxid-configuration} (default: @code{(ganeti-luxid-configuration)})
25646 @itemx @code{rapi-configuration} (default: @code{(ganeti-rapi-configuration)})
25647 @itemx @code{kvmd-configuration} (default: @code{(ganeti-kvmd-configuration)})
25648 @itemx @code{mond-configuration} (default: @code{(ganeti-mond-configuration)})
25649 @itemx @code{metad-configuration} (default: @code{(ganeti-metad-configuration)})
25650 @itemx @code{watcher-configuration} (default: @code{(ganeti-watcher-configuration)})
25651 @itemx @code{cleaner-configuration} (default: @code{(ganeti-cleaner-configuration)})
25653 These options control the various daemons and cron jobs that are distributed
25654 with Ganeti. The possible values for these are described in detail below.
25655 To override a setting, you must use the configuration type for that service:
25658 (service ganeti-service-type
25659 (ganeti-configuration
25660 (rapi-configuration
25661 (ganeti-rapi-configuration
25662 (interface "eth1"))))
25663 (watcher-configuration
25664 (ganeti-watcher-configuration
25665 (rapi-ip "10.0.0.1"))))
25668 @item @code{file-storage-paths} (default: @code{'()})
25669 List of allowed directories for file storage backend.
25671 @item @code{os} (default: @code{%default-ganeti-os})
25672 List of @code{<ganeti-os>} records.
25675 In essence @code{ganeti-service-type} is shorthand for declaring each service
25679 (service ganeti-noded-service-type)
25680 (service ganeti-confd-service-type)
25681 (service ganeti-wconfd-service-type)
25682 (service ganeti-luxid-service-type)
25683 (service ganeti-kvmd-service-type)
25684 (service ganeti-mond-service-type)
25685 (service ganeti-metad-service-type)
25686 (service ganeti-watcher-service-type)
25687 (service ganeti-cleaner-service-type)
25690 Plus a service extension for @code{etc-service-type} that configures the file
25691 storage backend and OS variants.
25695 @deftp {Data Type} ganeti-os
25696 This data type is suitable for passing to the @code{os} parameter of
25697 @code{ganeti-configuration}. It takes the following parameters:
25701 The name for this OS provider. It is only used to specify where the
25702 configuration ends up. Setting it to ``debootstrap'' will create
25703 @file{/etc/ganeti/instance-debootstrap}.
25705 @item @code{extension}
25706 The file extension for variants of this OS type. For example
25707 @file{.conf} or @file{.scm}.
25709 @item @code{variants} (default: @code{'()})
25710 List of @code{ganeti-os-variant} objects for this OS.
25715 @deftp {Data Type} ganeti-os-variant
25716 This is the data type for a Ganeti OS variant. It takes the following
25721 The name of this variant.
25723 @item @code{configuration}
25724 A configuration file for this variant.
25728 @defvr {Scheme Variable} %default-debootstrap-hooks
25729 This variable contains hooks to configure networking and the GRUB bootloader.
25732 @defvr {Scheme Variable} %default-debootstrap-extra-pkgs
25733 This variable contains a list of packages suitable for a fully-virtualized guest.
25736 @deftp {Data Type} debootstrap-configuration
25738 This data type creates configuration files suitable for the debootstrap OS provider.
25741 @item @code{hooks} (default: @code{%default-debootstrap-hooks})
25742 When not @code{#f}, this must be a G-expression that specifies a directory with
25743 scripts that will run when the OS is installed. It can also be a list of
25744 @code{(name . file-like)} pairs. For example:
25747 `((99-hello-world . ,(plain-file "#!/bin/sh\necho Hello, World")))
25750 That will create a directory with one executable named @code{99-hello-world}
25751 and run it every time this variant is installed. If set to @code{#f}, hooks
25752 in @file{/etc/ganeti/instance-debootstrap/hooks} will be used, if any.
25753 @item @code{proxy} (default: @code{#f})
25754 Optional HTTP proxy to use.
25755 @item @code{mirror} (default: @code{#f})
25756 The Debian mirror. Typically something like @code{http://ftp.no.debian.org/debian}.
25757 The default varies depending on the distribution.
25758 @item @code{arch} (default: @code{#f})
25759 The dpkg architecture. Set to @code{armhf} to debootstrap an ARMv7 instance
25760 on an AArch64 host. Default is to use the current system architecture.
25761 @item @code{suite} (default: @code{"stable"})
25762 When set, this must be a Debian distribution ``suite'' such as @code{buster}
25763 or @code{focal}. If set to @code{#f}, the default for the OS provider is used.
25764 @item @code{extra-pkgs} (default: @code{%default-debootstrap-extra-pkgs})
25765 List of extra packages that will get installed by dpkg in addition
25766 to the minimal system.
25767 @item @code{components} (default: @code{#f})
25768 When set, must be a list of Debian repository ``components''. For example
25769 @code{'("main" "contrib")}.
25770 @item @code{generate-cache?} (default: @code{#t})
25771 Whether to automatically cache the generated debootstrap archive.
25772 @item @code{clean-cache} (default: @code{14})
25773 Discard the cache after this amount of days. Use @code{#f} to never
25775 @item @code{partition-style} (default: @code{'msdos})
25776 The type of partition to create. When set, it must be one of
25777 @code{'msdos}, @code{'none} or a string.
25778 @item @code{partition-alignment} (default: @code{2048})
25779 Alignment of the partition in sectors.
25783 @deffn {Scheme Procedure} debootstrap-variant @var{name} @var{configuration}
25784 This is a helper procedure that creates a @code{ganeti-os-variant} record. It
25785 takes two parameters: a name and a @code{debootstrap-configuration} object.
25788 @deffn {Scheme Procedure} debootstrap-os @var{variants}@dots{}
25789 This is a helper procedure that creates a @code{ganeti-os} record. It takes
25790 a list of variants created with @code{debootstrap-variant}.
25793 @deffn {Scheme Procedure} guix-variant @var{name} @var{configuration}
25794 This is a helper procedure that creates a @code{ganeti-os-variant} record for
25795 use with the Guix OS provider. It takes a name and a G-expression that returns
25796 a ``file-like'' (@pxref{G-Expressions, file-like objects}) object containing a
25797 Guix System configuration.
25800 @deffn {Scheme Procedure} guix-os @var{variants}@dots{}
25801 This is a helper procedure that creates a @code{ganeti-os} record. It
25802 takes a list of variants produced by @code{guix-variant}.
25805 @defvr {Scheme Variable} %default-debootstrap-variants
25806 This is a convenience variable to make the debootstrap provider work
25807 ``out of the box'' without users having to declare variants manually. It
25808 contains a single debootstrap variant with the default configuration:
25811 (list (debootstrap-variant
25813 (debootstrap-configuration)))
25817 @defvr {Scheme Variable} %default-guix-variants
25818 This is a convenience variable to make the Guix OS provider work without
25819 additional configuration. It creates a virtual machine that has an SSH
25820 server, a serial console, and authorizes the Ganeti hosts SSH keys.
25823 (list (guix-variant
25825 (file-append ganeti-instance-guix
25826 "/share/doc/ganeti-instance-guix/examples/dynamic.scm")))
25830 Users can implement support for OS providers unbeknownst to Guix by extending
25831 the @code{ganeti-os} and @code{ganeti-os-variant} records appropriately.
25837 (extension ".conf")
25839 (list (ganeti-os-variant
25841 (configuration (plain-file "bar" "this is fine"))))))
25844 That creates @file{/etc/ganeti/instance-custom/variants/foo.conf} which points
25845 to a file in the store with contents @code{this is fine}. It also creates
25846 @file{/etc/ganeti/instance-custom/variants/variants.list} with contents @code{foo}.
25848 Obviously this may not work for all OS providers out there. If you find the
25849 interface limiting, please reach out to @email{guix-devel@@gnu.org}.
25851 The rest of this section documents the various services that are included by
25852 @code{ganeti-service-type}.
25854 @defvr {Scheme Variable} ganeti-noded-service-type
25855 @command{ganeti-noded} is the daemon responsible for node-specific functions
25856 within the Ganeti system. The value of this service must be a
25857 @code{ganeti-noded-configuration} object.
25860 @deftp {Data Type} ganeti-noded-configuration
25861 This is the configuration for the @code{ganeti-noded} service.
25864 @item @code{ganeti} (default: @code{ganeti})
25865 The @code{ganeti} package to use for this service.
25867 @item @code{port} (default: @code{1811})
25868 The TCP port on which the node daemon listens for network requests.
25870 @item @code{address} (default: @code{"0.0.0.0"})
25871 The network address that the daemon will bind to. The default address means
25872 bind to all available addresses.
25874 @item @code{interface} (default: @code{#f})
25875 When this is set, it must be a specific network interface (e.g.@: @code{eth0})
25876 that the daemon will bind to.
25878 @item @code{max-clients} (default: @code{20})
25879 This sets a limit on the maximum number of simultaneous client connections
25880 that the daemon will handle. Connections above this count are accepted, but
25881 no responses will be sent until enough connections have closed.
25883 @item @code{ssl?} (default: @code{#t})
25884 Whether to use SSL/TLS to encrypt network communications. The certificate
25885 is automatically provisioned by the cluster and can be rotated with
25886 @command{gnt-cluster renew-crypto}.
25888 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
25889 This can be used to provide a specific encryption key for TLS communications.
25891 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
25892 This can be used to provide a specific certificate for TLS communications.
25894 @item @code{debug?} (default: @code{#f})
25895 When true, the daemon performs additional logging for debugging purposes.
25896 Note that this will leak encryption details to the log files, use with caution.
25901 @defvr {Scheme Variable} ganeti-confd-service-type
25902 @command{ganeti-confd} answers queries related to the configuration of a
25903 Ganeti cluster. The purpose of this daemon is to have a highly available
25904 and fast way to query cluster configuration values. It is automatically
25905 active on all @dfn{master candidates}. The value of this service must be a
25906 @code{ganeti-confd-configuration} object.
25910 @deftp {Data Type} ganeti-confd-configuration
25911 This is the configuration for the @code{ganeti-confd} service.
25914 @item @code{ganeti} (default: @code{ganeti})
25915 The @code{ganeti} package to use for this service.
25917 @item @code{port} (default: @code{1814})
25918 The UDP port on which to listen for network requests.
25920 @item @code{address} (default: @code{"0.0.0.0"})
25921 Network address that the daemon will bind to.
25923 @item @code{debug?} (default: @code{#f})
25924 When true, the daemon performs additional logging for debugging purposes.
25929 @defvr {Scheme Variable} ganeti-wconfd-service-type
25930 @command{ganeti-wconfd} is the daemon that has authoritative knowledge
25931 about the cluster configuration and is the only entity that can accept
25932 changes to it. All jobs that need to modify the configuration will do so
25933 by sending appropriate requests to this daemon. It only runs on the
25934 @dfn{master node} and will automatically disable itself on other nodes.
25936 The value of this service must be a
25937 @code{ganeti-wconfd-configuration} object.
25940 @deftp {Data Type} ganeti-wconfd-configuration
25941 This is the configuration for the @code{ganeti-wconfd} service.
25944 @item @code{ganeti} (default: @code{ganeti})
25945 The @code{ganeti} package to use for this service.
25947 @item @code{no-voting?} (default: @code{#f})
25948 The daemon will refuse to start if the majority of cluster nodes does not
25949 agree that it is running on the master node. Set to @code{#t} to start
25950 even if a quorum can not be reached (dangerous, use with caution).
25952 @item @code{debug?} (default: @code{#f})
25953 When true, the daemon performs additional logging for debugging purposes.
25958 @defvr {Scheme Variable} ganeti-luxid-service-type
25959 @command{ganeti-luxid} is a daemon used to answer queries related to the
25960 configuration and the current live state of a Ganeti cluster. Additionally,
25961 it is the authoritative daemon for the Ganeti job queue. Jobs can be
25962 submitted via this daemon and it schedules and starts them.
25964 It takes a @code{ganeti-luxid-configuration} object.
25967 @deftp {Data Type} ganeti-luxid-configuration
25968 This is the configuration for the @code{ganeti-wconfd} service.
25971 @item @code{ganeti} (default: @code{ganeti})
25972 The @code{ganeti} package to use for this service.
25974 @item @code{no-voting?} (default: @code{#f})
25975 The daemon will refuse to start if it cannot verify that the majority of
25976 cluster nodes believes that it is running on the master node. Set to
25977 @code{#t} to ignore such checks and start anyway (this can be dangerous).
25979 @item @code{debug?} (default: @code{#f})
25980 When true, the daemon performs additional logging for debugging purposes.
25985 @defvr {Scheme Variable} ganeti-rapi-service-type
25986 @command{ganeti-rapi} provides a remote API for Ganeti clusters. It runs on
25987 the master node and can be used to perform cluster actions programmatically
25988 via a JSON-based RPC protocol.
25990 Most query operations are allowed without authentication (unless
25991 @var{require-authentication?} is set), whereas write operations require
25992 explicit authorization via the @file{/var/lib/ganeti/rapi/users} file. See
25993 the @url{http://docs.ganeti.org/ganeti/master/html/rapi.html, Ganeti Remote
25994 API documentation} for more information.
25996 The value of this service must be a @code{ganeti-rapi-configuration} object.
25999 @deftp {Data Type} ganeti-rapi-configuration
26000 This is the configuration for the @code{ganeti-rapi} service.
26003 @item @code{ganeti} (default: @code{ganeti})
26004 The @code{ganeti} package to use for this service.
26006 @item @code{require-authentication?} (default: @code{#f})
26007 Whether to require authentication even for read-only operations.
26009 @item @code{port} (default: @code{5080})
26010 The TCP port on which to listen to API requests.
26012 @item @code{address} (default: @code{"0.0.0.0"})
26013 The network address that the service will bind to. By default it listens
26014 on all configured addresses.
26016 @item @code{interface} (default: @code{#f})
26017 When set, it must specify a specific network interface such as @code{eth0}
26018 that the daemon will bind to.
26020 @item @code{max-clients} (default: @code{20})
26021 The maximum number of simultaneous client requests to handle. Further
26022 connections are allowed, but no responses are sent until enough connections
26025 @item @code{ssl?} (default: @code{#t})
26026 Whether to use SSL/TLS encryption on the RAPI port.
26028 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
26029 This can be used to provide a specific encryption key for TLS communications.
26031 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
26032 This can be used to provide a specific certificate for TLS communications.
26034 @item @code{debug?} (default: @code{#f})
26035 When true, the daemon performs additional logging for debugging purposes.
26036 Note that this will leak encryption details to the log files, use with caution.
26041 @defvr {Scheme Variable} ganeti-kvmd-service-type
26042 @command{ganeti-kvmd} is responsible for determining whether a given KVM
26043 instance was shut down by an administrator or a user. Normally Ganeti will
26044 restart an instance that was not stopped through Ganeti itself. If the
26045 cluster option @code{user_shutdown} is true, this daemon monitors the
26046 @code{QMP} socket provided by QEMU and listens for shutdown events, and
26047 marks the instance as @dfn{USER_down} instead of @dfn{ERROR_down} when
26048 it shuts down gracefully by itself.
26050 It takes a @code{ganeti-kvmd-configuration} object.
26053 @deftp {Data Type} ganeti-kvmd-configuration
26056 @item @code{ganeti} (default: @code{ganeti})
26057 The @code{ganeti} package to use for this service.
26059 @item @code{debug?} (default: @code{#f})
26060 When true, the daemon performs additional logging for debugging purposes.
26065 @defvr {Scheme Variable} ganeti-mond-service-type
26066 @command{ganeti-mond} is an optional daemon that provides Ganeti monitoring
26067 functionality. It is responsible for running data collectors and publish the
26068 collected information through a HTTP interface.
26070 It takes a @code{ganeti-mond-configuration} object.
26073 @deftp {Data Type} ganeti-mond-configuration
26076 @item @code{ganeti} (default: @code{ganeti})
26077 The @code{ganeti} package to use for this service.
26079 @item @code{port} (default: @code{1815})
26080 The port on which the daemon will listen.
26082 @item @code{address} (default: @code{"0.0.0.0"})
26083 The network address that the daemon will bind to. By default it binds to all
26084 available interfaces.
26086 @item @code{debug?} (default: @code{#f})
26087 When true, the daemon performs additional logging for debugging purposes.
26092 @defvr {Scheme Variable} ganeti-metad-service-type
26093 @command{ganeti-metad} is an optional daemon that can be used to provide
26094 information about the cluster to instances or OS install scripts.
26096 It takes a @code{ganeti-metad-configuration} object.
26099 @deftp {Data Type} ganeti-metad-configuration
26102 @item @code{ganeti} (default: @code{ganeti})
26103 The @code{ganeti} package to use for this service.
26105 @item @code{port} (default: @code{80})
26106 The port on which the daemon will listen.
26108 @item @code{address} (default: @code{#f})
26109 If set, the daemon will bind to this address only. If left unset, the behavior
26110 depends on the cluster configuration.
26112 @item @code{debug?} (default: @code{#f})
26113 When true, the daemon performs additional logging for debugging purposes.
26118 @defvr {Scheme Variable} ganeti-watcher-service-type
26119 @command{ganeti-watcher} is a script designed to run periodically and ensure
26120 the health of a cluster. It will automatically restart instances that have
26121 stopped without Ganetis consent, and repairs DRBD links in case a node has
26122 rebooted. It also archives old cluster jobs and restarts Ganeti daemons
26123 that are not running. If the cluster parameter @code{ensure_node_health}
26124 is set, the watcher will also shutdown instances and DRBD devices if the
26125 node it is running on is declared offline by known master candidates.
26127 It can be paused on all nodes with @command{gnt-cluster watcher pause}.
26129 The service takes a @code{ganeti-watcher-configuration} object.
26132 @deftp {Data Type} ganeti-watcher-configuration
26135 @item @code{ganeti} (default: @code{ganeti})
26136 The @code{ganeti} package to use for this service.
26138 @item @code{schedule} (default: @code{'(next-second-from (next-minute (range 0 60 5)))})
26139 How often to run the script. The default is every five minutes.
26141 @item @code{rapi-ip} (default: @code{#f})
26142 This option needs to be specified only if the RAPI daemon is configured to use
26143 a particular interface or address. By default the cluster address is used.
26145 @item @code{job-age} (default: @code{(* 6 3600)})
26146 Archive cluster jobs older than this age, specified in seconds. The default
26147 is 6 hours. This keeps @command{gnt-job list} manageable.
26149 @item @code{verify-disks?} (default: @code{#t})
26150 If this is @code{#f}, the watcher will not try to repair broken DRBD links
26151 automatically. Administrators will need to use @command{gnt-cluster verify-disks}
26154 @item @code{debug?} (default: @code{#f})
26155 When @code{#t}, the script performs additional logging for debugging purposes.
26160 @defvr {Scheme Variable} ganeti-cleaner-service-type
26161 @command{ganeti-cleaner} is a script designed to run periodically and remove
26162 old files from the cluster. This service type controls two @dfn{cron jobs}:
26163 one intended for the master node that permanently purges old cluster jobs,
26164 and one intended for every node that removes expired X509 certificates, keys,
26165 and outdated @command{ganeti-watcher} information. Like all Ganeti services,
26166 it is safe to include even on non-master nodes as it will disable itself as
26169 It takes a @code{ganeti-cleaner-configuration} object.
26172 @deftp {Data Type} ganeti-cleaner-configuration
26175 @item @code{ganeti} (default: @code{ganeti})
26176 The @code{ganeti} package to use for the @command{gnt-cleaner} command.
26178 @item @code{master-schedule} (default: @code{"45 1 * * *"})
26179 How often to run the master cleaning job. The default is once per day, at
26182 @item @code{node-schedule} (default: @code{"45 2 * * *"})
26183 How often to run the node cleaning job. The default is once per day, at
26189 @node Version Control Services
26190 @subsection Version Control Services
26192 The @code{(gnu services version-control)} module provides a service to
26193 allow remote access to local Git repositories. There are three options:
26194 the @code{git-daemon-service}, which provides access to repositories via
26195 the @code{git://} unsecured TCP-based protocol, extending the
26196 @code{nginx} web server to proxy some requests to
26197 @code{git-http-backend}, or providing a web interface with
26198 @code{cgit-service-type}.
26200 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
26202 Return a service that runs @command{git daemon}, a simple TCP server to
26203 expose repositories over the Git protocol for anonymous access.
26205 The optional @var{config} argument should be a
26206 @code{<git-daemon-configuration>} object, by default it allows read-only
26207 access to exported@footnote{By creating the magic file
26208 @file{git-daemon-export-ok} in the repository directory.} repositories under
26213 @deftp {Data Type} git-daemon-configuration
26214 Data type representing the configuration for @code{git-daemon-service}.
26217 @item @code{package} (default: @code{git})
26218 Package object of the Git distributed version control system.
26220 @item @code{export-all?} (default: @code{#f})
26221 Whether to allow access for all Git repositories, even if they do not
26222 have the @file{git-daemon-export-ok} file.
26224 @item @code{base-path} (default: @file{/srv/git})
26225 Whether to remap all the path requests as relative to the given path.
26226 If you run @command{git daemon} with @code{(base-path "/srv/git")} on
26227 @samp{example.com}, then if you later try to pull
26228 @indicateurl{git://example.com/hello.git}, git daemon will interpret the
26229 path as @file{/srv/git/hello.git}.
26231 @item @code{user-path} (default: @code{#f})
26232 Whether to allow @code{~user} notation to be used in requests. When
26233 specified with empty string, requests to
26234 @indicateurl{git://host/~alice/foo} is taken as a request to access
26235 @code{foo} repository in the home directory of user @code{alice}. If
26236 @code{(user-path "@var{path}")} is specified, the same request is taken
26237 as a request to access @file{@var{path}/foo} repository in the home
26238 directory of user @code{alice}.
26240 @item @code{listen} (default: @code{'()})
26241 Whether to listen on specific IP addresses or hostnames, defaults to
26244 @item @code{port} (default: @code{#f})
26245 Whether to listen on an alternative port, which defaults to 9418.
26247 @item @code{whitelist} (default: @code{'()})
26248 If not empty, only allow access to this list of directories.
26250 @item @code{extra-options} (default: @code{'()})
26251 Extra options will be passed to @command{git daemon}, please run
26252 @command{man git-daemon} for more information.
26257 The @code{git://} protocol lacks authentication. When you pull from a
26258 repository fetched via @code{git://}, you don't know whether the data you
26259 receive was modified or is even coming from the specified host, and your
26260 connection is subject to eavesdropping. It's better to use an authenticated
26261 and encrypted transport, such as @code{https}. Although Git allows you
26262 to serve repositories using unsophisticated file-based web servers,
26263 there is a faster protocol implemented by the @code{git-http-backend}
26264 program. This program is the back-end of a proper Git web service. It
26265 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
26266 on running the necessary @code{fcgiwrap} daemon.
26268 Guix has a separate configuration data type for serving Git repositories
26271 @deftp {Data Type} git-http-configuration
26272 Data type representing the configuration for a future
26273 @code{git-http-service-type}; can currently be used to configure Nginx
26274 trough @code{git-http-nginx-location-configuration}.
26277 @item @code{package} (default: @var{git})
26278 Package object of the Git distributed version control system.
26280 @item @code{git-root} (default: @file{/srv/git})
26281 Directory containing the Git repositories to expose to the world.
26283 @item @code{export-all?} (default: @code{#f})
26284 Whether to expose access for all Git repositories in @var{git-root},
26285 even if they do not have the @file{git-daemon-export-ok} file.
26287 @item @code{uri-path} (default: @samp{/git/})
26288 Path prefix for Git access. With the default @samp{/git/} prefix, this
26289 will map @indicateurl{http://@var{server}/git/@var{repo}.git} to
26290 @file{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
26291 with this prefix are not passed on to this Git instance.
26293 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
26294 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
26299 There is no @code{git-http-service-type}, currently; instead you can
26300 create an @code{nginx-location-configuration} from a
26301 @code{git-http-configuration} and then add that location to a web
26304 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
26305 [config=(git-http-configuration)]
26306 Compute an @code{nginx-location-configuration} that corresponds to the
26307 given Git http configuration. An example nginx service definition to
26308 serve the default @file{/srv/git} over HTTPS might be:
26311 (service nginx-service-type
26312 (nginx-configuration
26315 (nginx-server-configuration
26316 (listen '("443 ssl"))
26317 (server-name "git.my-host.org")
26319 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
26320 (ssl-certificate-key
26321 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
26324 (git-http-nginx-location-configuration
26325 (git-http-configuration (uri-path "/"))))))))))
26328 This example assumes that you are using Let's Encrypt to get your TLS
26329 certificate. @xref{Certificate Services}. The default @code{certbot}
26330 service will redirect all HTTP traffic on @code{git.my-host.org} to
26331 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
26332 system services. @xref{Web Services}.
26335 @subsubheading Cgit Service
26337 @cindex Cgit service
26338 @cindex Git, web interface
26339 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
26340 repositories written in C.
26342 The following example will configure the service with default values.
26343 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
26346 (service cgit-service-type)
26349 The @code{file-object} type designates either a file-like object
26350 (@pxref{G-Expressions, file-like objects}) or a string.
26352 @c %start of fragment
26354 Available @code{cgit-configuration} fields are:
26356 @deftypevr {@code{cgit-configuration} parameter} package package
26361 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
26362 NGINX configuration.
26366 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
26367 Specifies a command which will be invoked to format the content of about
26368 pages (both top-level and for each repository).
26370 Defaults to @samp{""}.
26374 @deftypevr {@code{cgit-configuration} parameter} string agefile
26375 Specifies a path, relative to each repository path, which can be used to
26376 specify the date and time of the youngest commit in the repository.
26378 Defaults to @samp{""}.
26382 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
26383 Specifies a command that will be invoked for authenticating repository
26386 Defaults to @samp{""}.
26390 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
26391 Flag which, when set to @samp{age}, enables date ordering in the branch
26392 ref list, and when set @samp{name} enables ordering by branch name.
26394 Defaults to @samp{"name"}.
26398 @deftypevr {@code{cgit-configuration} parameter} string cache-root
26399 Path used to store the cgit cache entries.
26401 Defaults to @samp{"/var/cache/cgit"}.
26405 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
26406 Number which specifies the time-to-live, in minutes, for the cached
26407 version of repository pages accessed with a fixed SHA1.
26409 Defaults to @samp{-1}.
26413 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
26414 Number which specifies the time-to-live, in minutes, for the cached
26415 version of repository pages accessed without a fixed SHA1.
26417 Defaults to @samp{5}.
26421 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
26422 Number which specifies the time-to-live, in minutes, for the cached
26423 version of the repository summary page.
26425 Defaults to @samp{5}.
26429 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
26430 Number which specifies the time-to-live, in minutes, for the cached
26431 version of the repository index page.
26433 Defaults to @samp{5}.
26437 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
26438 Number which specifies the time-to-live, in minutes, for the result of
26439 scanning a path for Git repositories.
26441 Defaults to @samp{15}.
26445 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
26446 Number which specifies the time-to-live, in minutes, for the cached
26447 version of the repository about page.
26449 Defaults to @samp{15}.
26453 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
26454 Number which specifies the time-to-live, in minutes, for the cached
26455 version of snapshots.
26457 Defaults to @samp{5}.
26461 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
26462 The maximum number of entries in the cgit cache. When set to @samp{0},
26463 caching is disabled.
26465 Defaults to @samp{0}.
26469 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
26470 Sort items in the repo list case sensitively.
26472 Defaults to @samp{#t}.
26476 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
26477 List of common prefixes which, when combined with a repository URL,
26478 generates valid clone URLs for the repository.
26480 Defaults to @samp{()}.
26484 @deftypevr {@code{cgit-configuration} parameter} list clone-url
26485 List of @code{clone-url} templates.
26487 Defaults to @samp{()}.
26491 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
26492 Command which will be invoked to format commit messages.
26494 Defaults to @samp{""}.
26498 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
26499 Flag which, when set to @samp{date}, enables strict date ordering in the
26500 commit log, and when set to @samp{topo} enables strict topological
26503 Defaults to @samp{"git log"}.
26507 @deftypevr {@code{cgit-configuration} parameter} file-object css
26508 URL which specifies the css document to include in all cgit pages.
26510 Defaults to @samp{"/share/cgit/cgit.css"}.
26514 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
26515 Specifies a command which will be invoked to format names and email
26516 address of committers, authors, and taggers, as represented in various
26517 places throughout the cgit interface.
26519 Defaults to @samp{""}.
26523 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
26524 Flag which, when set to @samp{#t}, will make cgit generate a HTML
26525 fragment suitable for embedding in other HTML pages.
26527 Defaults to @samp{#f}.
26531 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
26532 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
26533 commit history graph to the left of the commit messages in the
26534 repository log page.
26536 Defaults to @samp{#f}.
26540 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
26541 Flag which, when set to @samp{#t}, allows all filter settings to be
26542 overridden in repository-specific cgitrc files.
26544 Defaults to @samp{#f}.
26548 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
26549 Flag which, when set to @samp{#t}, allows users to follow a file in the
26552 Defaults to @samp{#f}.
26556 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
26557 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
26560 Defaults to @samp{#t}.
26564 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
26565 Flag which, when set to @samp{#t}, will make cgit generate extra links
26566 "summary", "commit", "tree" for each repo in the repository index.
26568 Defaults to @samp{#f}.
26572 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
26573 Flag which, when set to @samp{#t}, will make cgit display the owner of
26574 each repo in the repository index.
26576 Defaults to @samp{#t}.
26580 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
26581 Flag which, when set to @samp{#t}, will make cgit print the number of
26582 modified files for each commit on the repository log page.
26584 Defaults to @samp{#f}.
26588 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
26589 Flag which, when set to @samp{#t}, will make cgit print the number of
26590 added and removed lines for each commit on the repository log page.
26592 Defaults to @samp{#f}.
26596 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
26597 Flag which, when set to @code{#t}, will make cgit display remote
26598 branches in the summary and refs views.
26600 Defaults to @samp{#f}.
26604 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
26605 Flag which, when set to @code{1}, 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-html-serving?
26614 Flag which, when set to @samp{#t}, will make cgit use the subject of the
26615 parent commit as link text when generating links to parent commits in
26618 Defaults to @samp{#f}.
26622 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
26623 Flag which, when set to @samp{#t}, will make cgit generate linenumber
26624 links for plaintext blobs printed in the tree view.
26626 Defaults to @samp{#t}.
26630 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
26631 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
26632 set any repo specific settings.
26634 Defaults to @samp{#f}.
26638 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
26639 URL used as link to a shortcut icon for cgit.
26641 Defaults to @samp{"/favicon.ico"}.
26645 @deftypevr {@code{cgit-configuration} parameter} string footer
26646 The content of the file specified with this option will be included
26647 verbatim at the bottom of all pages (i.e.@: it replaces the standard
26648 "generated by..."@: message).
26650 Defaults to @samp{""}.
26654 @deftypevr {@code{cgit-configuration} parameter} string head-include
26655 The content of the file specified with this option will be included
26656 verbatim in the HTML HEAD section on all pages.
26658 Defaults to @samp{""}.
26662 @deftypevr {@code{cgit-configuration} parameter} string header
26663 The content of the file specified with this option will be included
26664 verbatim at the top of all pages.
26666 Defaults to @samp{""}.
26670 @deftypevr {@code{cgit-configuration} parameter} file-object include
26671 Name of a configfile to include before the rest of the current config-
26674 Defaults to @samp{""}.
26678 @deftypevr {@code{cgit-configuration} parameter} string index-header
26679 The content of the file specified with this option will be included
26680 verbatim above the repository index.
26682 Defaults to @samp{""}.
26686 @deftypevr {@code{cgit-configuration} parameter} string index-info
26687 The content of the file specified with this option will be included
26688 verbatim below the heading on the repository index page.
26690 Defaults to @samp{""}.
26694 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
26695 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
26696 in the servers timezone.
26698 Defaults to @samp{#f}.
26702 @deftypevr {@code{cgit-configuration} parameter} file-object logo
26703 URL which specifies the source of an image which will be used as a logo
26706 Defaults to @samp{"/share/cgit/cgit.png"}.
26710 @deftypevr {@code{cgit-configuration} parameter} string logo-link
26711 URL loaded when clicking on the cgit logo image.
26713 Defaults to @samp{""}.
26717 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
26718 Command which will be invoked to format the Owner column of the main
26721 Defaults to @samp{""}.
26725 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
26726 Number of items to display in atom feeds view.
26728 Defaults to @samp{10}.
26732 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
26733 Number of entries to list per page in "log" view.
26735 Defaults to @samp{50}.
26739 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
26740 Number of commit message characters to display in "log" view.
26742 Defaults to @samp{80}.
26746 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
26747 Specifies the number of entries to list per page on the repository index
26750 Defaults to @samp{50}.
26754 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
26755 Specifies the maximum number of repo description characters to display
26756 on the repository index page.
26758 Defaults to @samp{80}.
26762 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
26763 Specifies the maximum size of a blob to display HTML for in KBytes.
26765 Defaults to @samp{0}.
26769 @deftypevr {@code{cgit-configuration} parameter} string max-stats
26770 Maximum statistics period. Valid values are @samp{week},@samp{month},
26771 @samp{quarter} and @samp{year}.
26773 Defaults to @samp{""}.
26777 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
26778 Mimetype for the specified filename extension.
26780 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
26781 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
26782 "image/png") (svg "image/svg+xml"))}.
26786 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
26787 Specifies the file to use for automatic mimetype lookup.
26789 Defaults to @samp{""}.
26793 @deftypevr {@code{cgit-configuration} parameter} string module-link
26794 Text which will be used as the formatstring for a hyperlink when a
26795 submodule is printed in a directory listing.
26797 Defaults to @samp{""}.
26801 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
26802 If set to the value @samp{#t} caching will be disabled.
26804 Defaults to @samp{#f}.
26808 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
26809 If set to @samp{#t} showing full author email addresses will be
26812 Defaults to @samp{#f}.
26816 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
26817 Flag which, when set to @samp{#t}, will make cgit omit the standard
26818 header on all pages.
26820 Defaults to @samp{#f}.
26824 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
26825 A list of subdirectories inside of @code{repository-directory}, relative
26826 to it, that should loaded as Git repositories. An empty list means that
26827 all subdirectories will be loaded.
26829 Defaults to @samp{()}.
26833 @deftypevr {@code{cgit-configuration} parameter} file-object readme
26834 Text which will be used as default value for @code{cgit-repo-readme}.
26836 Defaults to @samp{""}.
26840 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
26841 If set to @code{#t} and @code{repository-directory} is enabled, if any
26842 repositories are found with a suffix of @code{.git}, this suffix will be
26843 removed for the URL and name.
26845 Defaults to @samp{#f}.
26849 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
26850 Maximum number of files to consider when detecting renames.
26852 Defaults to @samp{-1}.
26856 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
26857 The way in which repositories in each section are sorted.
26859 Defaults to @samp{""}.
26863 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
26864 Text used as content for the @code{robots} meta-tag.
26866 Defaults to @samp{("noindex" "nofollow")}.
26870 @deftypevr {@code{cgit-configuration} parameter} string root-desc
26871 Text printed below the heading on the repository index page.
26873 Defaults to @samp{"a fast webinterface for the git dscm"}.
26877 @deftypevr {@code{cgit-configuration} parameter} string root-readme
26878 The content of the file specified with this option will be included
26879 verbatim below the ``about'' link on the repository index page.
26881 Defaults to @samp{""}.
26885 @deftypevr {@code{cgit-configuration} parameter} string root-title
26886 Text printed as heading on the repository index page.
26888 Defaults to @samp{""}.
26892 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
26893 If set to @samp{#t} and repository-directory is enabled,
26894 repository-directory will recurse into directories whose name starts
26895 with a period. Otherwise, repository-directory will stay away from such
26896 directories, considered as ``hidden''. Note that this does not apply to
26897 the @file{.git} directory in non-bare repos.
26899 Defaults to @samp{#f}.
26903 @deftypevr {@code{cgit-configuration} parameter} list snapshots
26904 Text which specifies the default set of snapshot formats that cgit
26905 generates links for.
26907 Defaults to @samp{()}.
26911 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
26912 Name of the directory to scan for repositories (represents
26915 Defaults to @samp{"/srv/git"}.
26919 @deftypevr {@code{cgit-configuration} parameter} string section
26920 The name of the current repository section - all repositories defined
26921 after this option will inherit the current section name.
26923 Defaults to @samp{""}.
26927 @deftypevr {@code{cgit-configuration} parameter} string section-sort
26928 Flag which, when set to @samp{1}, will sort the sections on the
26929 repository listing by name.
26931 Defaults to @samp{""}.
26935 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
26936 A number which, if defined prior to repository-directory, specifies how
26937 many path elements from each repo path to use as a default section name.
26939 Defaults to @samp{0}.
26943 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
26944 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
26947 Defaults to @samp{#f}.
26951 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
26952 Specifies a command which will be invoked to format plaintext blobs in
26955 Defaults to @samp{""}.
26959 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
26960 Specifies the number of branches to display in the repository ``summary''
26963 Defaults to @samp{10}.
26967 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
26968 Specifies the number of log entries to display in the repository
26971 Defaults to @samp{10}.
26975 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
26976 Specifies the number of tags to display in the repository ``summary''
26979 Defaults to @samp{10}.
26983 @deftypevr {@code{cgit-configuration} parameter} string strict-export
26984 Filename which, if specified, needs to be present within the repository
26985 for cgit to allow access to that repository.
26987 Defaults to @samp{""}.
26991 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
26992 URL which, if specified, will be used as root for all cgit links.
26994 Defaults to @samp{"/"}.
26998 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
26999 A list of @dfn{cgit-repo} records to use with config.
27001 Defaults to @samp{()}.
27003 Available @code{repository-cgit-configuration} fields are:
27005 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
27006 A mask of snapshot formats for this repo that cgit generates links for,
27007 restricted by the global @code{snapshots} setting.
27009 Defaults to @samp{()}.
27013 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
27014 Override the default @code{source-filter}.
27016 Defaults to @samp{""}.
27020 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
27021 The relative URL used to access the repository.
27023 Defaults to @samp{""}.
27027 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
27028 Override the default @code{about-filter}.
27030 Defaults to @samp{""}.
27034 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
27035 Flag which, when set to @samp{age}, enables date ordering in the branch
27036 ref list, and when set to @samp{name} enables ordering by branch name.
27038 Defaults to @samp{""}.
27042 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
27043 A list of URLs which can be used to clone repo.
27045 Defaults to @samp{()}.
27049 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
27050 Override the default @code{commit-filter}.
27052 Defaults to @samp{""}.
27056 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
27057 Flag which, when set to @samp{date}, enables strict date ordering in the
27058 commit log, and when set to @samp{topo} enables strict topological
27061 Defaults to @samp{""}.
27065 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
27066 The name of the default branch for this repository. If no such branch
27067 exists in the repository, the first branch name (when sorted) is used as
27068 default instead. By default branch pointed to by HEAD, or ``master'' if
27069 there is no suitable HEAD.
27071 Defaults to @samp{""}.
27075 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
27076 The value to show as repository description.
27078 Defaults to @samp{""}.
27082 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
27083 The value to show as repository homepage.
27085 Defaults to @samp{""}.
27089 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
27090 Override the default @code{email-filter}.
27092 Defaults to @samp{""}.
27096 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
27097 A flag which can be used to disable the global setting
27098 @code{enable-commit-graph?}.
27100 Defaults to @samp{disabled}.
27104 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
27105 A flag which can be used to disable the global setting
27106 @code{enable-log-filecount?}.
27108 Defaults to @samp{disabled}.
27112 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
27113 A flag which can be used to disable the global setting
27114 @code{enable-log-linecount?}.
27116 Defaults to @samp{disabled}.
27120 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
27121 Flag which, when set to @code{#t}, will make cgit display remote
27122 branches in the summary and refs views.
27124 Defaults to @samp{disabled}.
27128 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
27129 A flag which can be used to override the global setting
27130 @code{enable-subject-links?}.
27132 Defaults to @samp{disabled}.
27136 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
27137 A flag which can be used to override the global setting
27138 @code{enable-html-serving?}.
27140 Defaults to @samp{disabled}.
27144 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
27145 Flag which, when set to @code{#t}, hides the repository from the
27148 Defaults to @samp{#f}.
27152 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
27153 Flag which, when set to @samp{#t}, ignores the repository.
27155 Defaults to @samp{#f}.
27159 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
27160 URL which specifies the source of an image which will be used as a logo
27161 on this repo’s pages.
27163 Defaults to @samp{""}.
27167 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
27168 URL loaded when clicking on the cgit logo image.
27170 Defaults to @samp{""}.
27174 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
27175 Override the default @code{owner-filter}.
27177 Defaults to @samp{""}.
27181 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
27182 Text which will be used as the formatstring for a hyperlink when a
27183 submodule is printed in a directory listing. The arguments for the
27184 formatstring are the path and SHA1 of the submodule commit.
27186 Defaults to @samp{""}.
27190 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
27191 Text which will be used as the formatstring for a hyperlink when a
27192 submodule with the specified subdirectory path is printed in a directory
27195 Defaults to @samp{()}.
27199 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
27200 Override the default maximum statistics period.
27202 Defaults to @samp{""}.
27206 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
27207 The value to show as repository name.
27209 Defaults to @samp{""}.
27213 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
27214 A value used to identify the owner of the repository.
27216 Defaults to @samp{""}.
27220 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
27221 An absolute path to the repository directory.
27223 Defaults to @samp{""}.
27227 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
27228 A path (relative to repo) which specifies a file to include verbatim as
27229 the ``About'' page for this repo.
27231 Defaults to @samp{""}.
27235 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
27236 The name of the current repository section - all repositories defined
27237 after this option will inherit the current section name.
27239 Defaults to @samp{""}.
27243 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
27244 Extra options will be appended to cgitrc file.
27246 Defaults to @samp{()}.
27252 @deftypevr {@code{cgit-configuration} parameter} list extra-options
27253 Extra options will be appended to cgitrc file.
27255 Defaults to @samp{()}.
27260 @c %end of fragment
27262 However, it could be that you just want to get a @code{cgitrc} up and
27263 running. In that case, you can pass an @code{opaque-cgit-configuration}
27264 as a record to @code{cgit-service-type}. As its name indicates, an
27265 opaque configuration does not have easy reflective capabilities.
27267 Available @code{opaque-cgit-configuration} fields are:
27269 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
27273 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
27274 The contents of the @code{cgitrc}, as a string.
27277 For example, if your @code{cgitrc} is just the empty string, you
27278 could instantiate a cgit service like this:
27281 (service cgit-service-type
27282 (opaque-cgit-configuration
27286 @subsubheading Gitolite Service
27288 @cindex Gitolite service
27289 @cindex Git, hosting
27290 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
27291 repositories on a central server.
27293 Gitolite can handle multiple repositories and users, and supports flexible
27294 configuration of the permissions for the users on the repositories.
27296 The following example will configure Gitolite using the default @code{git}
27297 user, and the provided SSH public key.
27300 (service gitolite-service-type
27301 (gitolite-configuration
27302 (admin-pubkey (plain-file
27304 "ssh-rsa AAAA... guix@@example.com"))))
27307 Gitolite is configured through a special admin repository which you can clone,
27308 for example, if you setup Gitolite on @code{example.com}, you would run the
27309 following command to clone the admin repository.
27312 git clone git@@example.com:gitolite-admin
27315 When the Gitolite service is activated, the provided @code{admin-pubkey} will
27316 be inserted in to the @file{keydir} directory in the gitolite-admin
27317 repository. If this results in a change in the repository, it will be
27318 committed using the message ``gitolite setup by GNU Guix''.
27320 @deftp {Data Type} gitolite-configuration
27321 Data type representing the configuration for @code{gitolite-service-type}.
27324 @item @code{package} (default: @var{gitolite})
27325 Gitolite package to use.
27327 @item @code{user} (default: @var{git})
27328 User to use for Gitolite. This will be user that you use when accessing
27331 @item @code{group} (default: @var{git})
27332 Group to use for Gitolite.
27334 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
27335 Directory in which to store the Gitolite configuration and repositories.
27337 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
27338 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
27339 representing the configuration for Gitolite.
27341 @item @code{admin-pubkey} (default: @var{#f})
27342 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
27343 setup Gitolite. This will be inserted in to the @file{keydir} directory
27344 within the gitolite-admin repository.
27346 To specify the SSH key as a string, use the @code{plain-file} function.
27349 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
27355 @deftp {Data Type} gitolite-rc-file
27356 Data type representing the Gitolite RC file.
27359 @item @code{umask} (default: @code{#o0077})
27360 This controls the permissions Gitolite sets on the repositories and their
27363 A value like @code{#o0027} will give read access to the group used by Gitolite
27364 (by default: @code{git}). This is necessary when using Gitolite with software
27365 like cgit or gitweb.
27367 @item @code{git-config-keys} (default: @code{""})
27368 Gitolite allows you to set git config values using the @samp{config} keyword. This
27369 setting allows control over the config keys to accept.
27371 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
27372 Set the role names allowed to be used by users running the perms command.
27374 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
27375 This setting controls the commands and features to enable within Gitolite.
27381 @node Game Services
27382 @subsection Game Services
27384 @subsubheading The Battle for Wesnoth Service
27386 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
27387 based tactical strategy game, with several single player campaigns, and
27388 multiplayer games (both networked and local).
27390 @defvar {Scheme Variable} wesnothd-service-type
27391 Service type for the wesnothd service. Its value must be a
27392 @code{wesnothd-configuration} object. To run wesnothd in the default
27393 configuration, instantiate it as:
27396 (service wesnothd-service-type)
27400 @deftp {Data Type} wesnothd-configuration
27401 Data type representing the configuration of @command{wesnothd}.
27404 @item @code{package} (default: @code{wesnoth-server})
27405 The wesnoth server package to use.
27407 @item @code{port} (default: @code{15000})
27408 The port to bind the server to.
27413 @node PAM Mount Service
27414 @subsection PAM Mount Service
27417 The @code{(gnu services pam-mount)} module provides a service allowing
27418 users to mount volumes when they log in. It should be able to mount any
27419 volume format supported by the system.
27421 @defvar {Scheme Variable} pam-mount-service-type
27422 Service type for PAM Mount support.
27425 @deftp {Data Type} pam-mount-configuration
27426 Data type representing the configuration of PAM Mount.
27428 It takes the following parameters:
27432 The configuration rules that will be used to generate
27433 @file{/etc/security/pam_mount.conf.xml}.
27435 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
27436 Guile Reference Manual}), and the the default ones don't mount anything
27437 for anyone at login:
27440 `((debug (@@ (enable "0")))
27441 (mntoptions (@@ (allow ,(string-join
27442 '("nosuid" "nodev" "loop"
27443 "encryption" "fsck" "nonempty"
27444 "allow_root" "allow_other")
27446 (mntoptions (@@ (require "nosuid,nodev")))
27447 (logout (@@ (wait "0")
27451 (mkmountpoint (@@ (enable "1")
27455 Some @code{volume} elements must be added to automatically mount volumes
27456 at login. Here's an example allowing the user @code{alice} to mount her
27457 encrypted @env{HOME} directory and allowing the user @code{bob} to mount
27458 the partition where he stores his data:
27461 (define pam-mount-rules
27462 `((debug (@@ (enable "0")))
27463 (volume (@@ (user "alice")
27466 (mountpoint "/home/alice")))
27467 (volume (@@ (user "bob")
27470 (mountpoint "/home/bob/data")
27471 (options "defaults,autodefrag,compress")))
27472 (mntoptions (@@ (allow ,(string-join
27473 '("nosuid" "nodev" "loop"
27474 "encryption" "fsck" "nonempty"
27475 "allow_root" "allow_other")
27477 (mntoptions (@@ (require "nosuid,nodev")))
27478 (logout (@@ (wait "0")
27482 (mkmountpoint (@@ (enable "1")
27483 (remove "true")))))
27485 (service pam-mount-service-type
27486 (pam-mount-configuration
27487 (rules pam-mount-rules)))
27490 The complete list of possible options can be found in the man page for
27491 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
27496 @node Guix Services
27497 @subsection Guix Services
27499 @subsubheading Guix Data Service
27500 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
27501 and provides data about GNU Guix. This includes information about
27502 packages, derivations and lint warnings.
27504 The data is stored in a PostgreSQL database, and available through a web
27507 @defvar {Scheme Variable} guix-data-service-type
27508 Service type for the Guix Data Service. Its value must be a
27509 @code{guix-data-service-configuration} object. The service optionally
27510 extends the getmail service, as the guix-commits mailing list is used to
27511 find out about changes in the Guix git repository.
27514 @deftp {Data Type} guix-data-service-configuration
27515 Data type representing the configuration of the Guix Data Service.
27518 @item @code{package} (default: @code{guix-data-service})
27519 The Guix Data Service package to use.
27521 @item @code{user} (default: @code{"guix-data-service"})
27522 The system user to run the service as.
27524 @item @code{group} (default: @code{"guix-data-service"})
27525 The system group to run the service as.
27527 @item @code{port} (default: @code{8765})
27528 The port to bind the web service to.
27530 @item @code{host} (default: @code{"127.0.0.1"})
27531 The host to bind the web service to.
27533 @item @code{getmail-idle-mailboxes} (default: @code{#f})
27534 If set, this is the list of mailboxes that the getmail service will be
27535 configured to listen to.
27537 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
27538 If set, this is the @code{getmail-retriever-configuration} object with
27539 which to configure getmail to fetch mail from the guix-commits mailing
27542 @item @code{extra-options} (default: @var{'()})
27543 Extra command line options for @code{guix-data-service}.
27545 @item @code{extra-process-jobs-options} (default: @var{'()})
27546 Extra command line options for @code{guix-data-service-process-jobs}.
27551 @node Linux Services
27552 @subsection Linux Services
27555 @cindex out of memory killer
27557 @cindex early out of memory daemon
27558 @subsubheading Early OOM Service
27560 @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
27561 Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
27562 space and provides a more responsive and configurable alternative to the
27563 in-kernel OOM killer. It is useful to prevent the system from becoming
27564 unresponsive when it runs out of memory.
27566 @deffn {Scheme Variable} earlyoom-service-type
27567 The service type for running @command{earlyoom}, the Early OOM daemon.
27568 Its value must be a @code{earlyoom-configuration} object, described
27569 below. The service can be instantiated in its default configuration
27573 (service earlyoom-service-type)
27577 @deftp {Data Type} earlyoom-configuration
27578 This is the configuration record for the @code{earlyoom-service-type}.
27581 @item @code{earlyoom} (default: @var{earlyoom})
27582 The Earlyoom package to use.
27584 @item @code{minimum-available-memory} (default: @code{10})
27585 The threshold for the minimum @emph{available} memory, in percentages.
27587 @item @code{minimum-free-swap} (default: @code{10})
27588 The threshold for the minimum free swap memory, in percentages.
27590 @item @code{prefer-regexp} (default: @code{#f})
27591 A regular expression (as a string) to match the names of the processes
27592 that should be preferably killed.
27594 @item @code{avoid-regexp} (default: @code{#f})
27595 A regular expression (as a string) to match the names of the processes
27596 that should @emph{not} be killed.
27598 @item @code{memory-report-interval} (default: @code{0})
27599 The interval in seconds at which a memory report is printed. It is
27600 disabled by default.
27602 @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
27603 A boolean indicating whether the positive adjustments set in
27604 @file{/proc/*/oom_score_adj}.
27606 @item @code{show-debug-messages?} (default: @code{#f})
27607 A boolean indicating whether debug messages should be printed. The logs
27608 are saved at @file{/var/log/earlyoom.log}.
27610 @item @code{send-notification-command} (default: @code{#f})
27611 This can be used to provide a custom command used for sending
27617 @cindex kernel module loader
27618 @subsubheading Kernel Module Loader Service
27620 The kernel module loader service allows one to load loadable kernel
27621 modules at boot. This is especially useful for modules that don't
27622 autoload and need to be manually loaded, as it's the case with
27625 @deffn {Scheme Variable} kernel-module-loader-service-type
27626 The service type for loading loadable kernel modules at boot with
27627 @command{modprobe}. Its value must be a list of strings representing
27628 module names. For example loading the drivers provided by
27629 @code{ddcci-driver-linux}, in debugging mode by passing some module
27630 parameters, can be done as follow:
27633 (use-modules (gnu) (gnu services))
27634 (use-package-modules linux)
27635 (use-service-modules linux)
27637 (define ddcci-config
27638 (plain-file "ddcci.conf"
27639 "options ddcci dyndbg delay=120"))
27643 (services (cons* (service kernel-module-loader-service-type
27644 '("ddcci" "ddcci_backlight"))
27645 (simple-service 'ddcci-config etc-service-type
27646 (list `("modprobe.d/ddcci.conf"
27649 (kernel-loadable-modules (list ddcci-driver-linux)))
27654 @cindex compressed swap
27655 @cindex Compressed RAM-based block devices
27656 @subsubheading Zram Device Service
27658 The Zram device service provides a compressed swap device in system
27659 memory. The Linux Kernel documentation has more information about
27660 @uref{https://www.kernel.org/doc/html/latest/admin-guide/blockdev/zram.html,zram}
27663 @deffn {Scheme Variable} zram-device-service-type
27664 This service creates the zram block device, formats it as swap and
27665 enables it as a swap device. The service's value is a
27666 @code{zram-device-configuration} record.
27668 @deftp {Data Type} zram-device-configuration
27669 This is the data type representing the configuration for the zram-device
27673 @item @code{size} (default @var{"1G"})
27674 This is the amount of space you wish to provide for the zram device. It
27675 accepts a string and can be a number of bytes or use a suffix, eg.:
27676 @var{"512M"} or @var{1024000}.
27677 @item @code{compression-algorithm} (default @var{'lzo})
27678 This is the compression algorithm you wish to use. It is difficult to
27679 list all the possible compression options, but common ones supported by
27680 Guix's Linux Libre Kernel include @var{'lzo}, @var{'lz4} and @var{'zstd}.
27681 @item @code{memory-limit} (default @var{0})
27682 This is the maximum amount of memory which the zram device can use.
27683 Setting it to '0' disables the limit. While it is generally expected
27684 that compression will be 2:1, it is possible that uncompressable data
27685 can be written to swap and this is a method to limit how much memory can
27686 be used. It accepts a string and can be a number of bytes or use a
27687 suffix, eg.: @var{"2G"}.
27688 @item @code{priority} (default @var{-1})
27689 This is the priority of the swap device created from the zram device.
27690 @code{swapon} accepts values between -1 and 32767, with higher values
27691 indicating higher priority. Higher priority swap will generally be used
27698 @node Hurd Services
27699 @subsection Hurd Services
27701 @defvr {Scheme Variable} hurd-console-service-type
27702 This service starts the fancy @code{VGA} console client on the Hurd.
27704 The service's value is a @code{hurd-console-configuration} record.
27707 @deftp {Data Type} hurd-console-configuration
27708 This is the data type representing the configuration for the
27709 hurd-console-service.
27712 @item @code{hurd} (default: @var{hurd})
27713 The Hurd package to use.
27717 @defvr {Scheme Variable} hurd-getty-service-type
27718 This service starts a tty using the Hurd @code{getty} program.
27720 The service's value is a @code{hurd-getty-configuration} record.
27723 @deftp {Data Type} hurd-getty-configuration
27724 This is the data type representing the configuration for the
27725 hurd-getty-service.
27728 @item @code{hurd} (default: @var{hurd})
27729 The Hurd package to use.
27732 The name of the console this Getty runs on---e.g., @code{"tty1"}.
27734 @item @code{baud-rate} (default: @code{38400})
27735 An integer specifying the baud rate of the tty.
27740 @node Miscellaneous Services
27741 @subsection Miscellaneous Services
27743 @cindex fingerprint
27744 @subsubheading Fingerprint Service
27746 The @code{(gnu services authentication)} module provides a DBus service to
27747 read and identify fingerprints via a fingerprint sensor.
27749 @defvr {Scheme Variable} fprintd-service-type
27750 The service type for @command{fprintd}, which provides the fingerprint
27751 reading capability.
27754 (service fprintd-service-type)
27759 @subsubheading System Control Service
27761 The @code{(gnu services sysctl)} provides a service to configure kernel
27762 parameters at boot.
27764 @defvr {Scheme Variable} sysctl-service-type
27765 The service type for @command{sysctl}, which modifies kernel parameters
27766 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
27770 (service sysctl-service-type
27771 (sysctl-configuration
27772 (settings '(("net.ipv4.ip_forward" . "1")))))
27776 @deftp {Data Type} sysctl-configuration
27777 The data type representing the configuration of @command{sysctl}.
27780 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
27781 The @command{sysctl} executable to use.
27783 @item @code{settings} (default: @code{'()})
27784 An association list specifies kernel parameters and their values.
27789 @subsubheading PC/SC Smart Card Daemon Service
27791 The @code{(gnu services security-token)} module provides the following service
27792 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
27793 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
27794 manager that coordinates communications with smart card readers, smart cards
27795 and cryptographic tokens that are connected to the system.
27797 @defvr {Scheme Variable} pcscd-service-type
27798 Service type for the @command{pcscd} service. Its value must be a
27799 @code{pcscd-configuration} object. To run pcscd in the default
27800 configuration, instantiate it as:
27803 (service pcscd-service-type)
27807 @deftp {Data Type} pcscd-configuration
27808 The data type representing the configuration of @command{pcscd}.
27811 @item @code{pcsc-lite} (default: @code{pcsc-lite})
27812 The pcsc-lite package that provides pcscd.
27813 @item @code{usb-drivers} (default: @code{(list ccid)})
27814 List of packages that provide USB drivers to pcscd. Drivers are expected to be
27815 under @file{pcsc/drivers} in the store directory of the package.
27820 @subsubheading Lirc Service
27822 The @code{(gnu services lirc)} module provides the following service.
27824 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
27825 [#:device #f] [#:driver #f] [#:config-file #f] @
27826 [#:extra-options '()]
27827 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
27828 decodes infrared signals from remote controls.
27830 Optionally, @var{device}, @var{driver} and @var{config-file}
27831 (configuration file name) may be specified. See @command{lircd} manual
27834 Finally, @var{extra-options} is a list of additional command-line options
27835 passed to @command{lircd}.
27839 @subsubheading Spice Service
27841 The @code{(gnu services spice)} module provides the following service.
27843 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
27844 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
27845 that enables sharing the clipboard with a vm and setting the guest display
27846 resolution when the graphical console window resizes.
27849 @cindex inputattach
27850 @subsubheading inputattach Service
27852 @cindex tablet input, for Xorg
27853 @cindex touchscreen input, for Xorg
27854 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
27855 use input devices such as Wacom tablets, touchscreens, or joysticks with the
27856 Xorg display server.
27858 @deffn {Scheme Variable} inputattach-service-type
27859 Type of a service that runs @command{inputattach} on a device and
27860 dispatches events from it.
27863 @deftp {Data Type} inputattach-configuration
27865 @item @code{device-type} (default: @code{"wacom"})
27866 The type of device to connect to. Run @command{inputattach --help}, from the
27867 @code{inputattach} package, to see the list of supported device types.
27869 @item @code{device} (default: @code{"/dev/ttyS0"})
27870 The device file to connect to the device.
27872 @item @code{baud-rate} (default: @code{#f})
27873 Baud rate to use for the serial connection.
27874 Should be a number or @code{#f}.
27876 @item @code{log-file} (default: @code{#f})
27877 If true, this must be the name of a file to log messages to.
27881 @subsubheading Dictionary Service
27883 The @code{(gnu services dict)} module provides the following service:
27885 @defvr {Scheme Variable} dicod-service-type
27886 This is the type of the service that runs the @command{dicod} daemon, an
27887 implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
27890 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
27891 Return a service that runs the @command{dicod} daemon, an implementation
27892 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
27894 The optional @var{config} argument specifies the configuration for
27895 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
27896 default it serves the GNU Collaborative International Dictionary of English.
27898 You can add @command{open localhost} to your @file{~/.dico} file to make
27899 @code{localhost} the default server for @command{dico} client
27900 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
27903 @deftp {Data Type} dicod-configuration
27904 Data type representing the configuration of dicod.
27907 @item @code{dico} (default: @var{dico})
27908 Package object of the GNU Dico dictionary server.
27910 @item @code{interfaces} (default: @var{'("localhost")})
27911 This is the list of IP addresses and ports and possibly socket file
27912 names to listen to (@pxref{Server Settings, @code{listen} directive,,
27913 dico, GNU Dico Manual}).
27915 @item @code{handlers} (default: @var{'()})
27916 List of @code{<dicod-handler>} objects denoting handlers (module instances).
27918 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
27919 List of @code{<dicod-database>} objects denoting dictionaries to be served.
27923 @deftp {Data Type} dicod-handler
27924 Data type representing a dictionary handler (module instance).
27928 Name of the handler (module instance).
27930 @item @code{module} (default: @var{#f})
27931 Name of the dicod module of the handler (instance). If it is @code{#f},
27932 the module has the same name as the handler.
27933 (@pxref{Modules,,, dico, GNU Dico Manual}).
27935 @item @code{options}
27936 List of strings or gexps representing the arguments for the module handler
27940 @deftp {Data Type} dicod-database
27941 Data type representing a dictionary database.
27945 Name of the database, will be used in DICT commands.
27947 @item @code{handler}
27948 Name of the dicod handler (module instance) used by this database
27949 (@pxref{Handlers,,, dico, GNU Dico Manual}).
27951 @item @code{complex?} (default: @var{#f})
27952 Whether the database configuration complex. The complex configuration
27953 will need a corresponding @code{<dicod-handler>} object, otherwise not.
27955 @item @code{options}
27956 List of strings or gexps representing the arguments for the database
27957 (@pxref{Databases,,, dico, GNU Dico Manual}).
27961 @defvr {Scheme Variable} %dicod-database:gcide
27962 A @code{<dicod-database>} object serving the GNU Collaborative International
27963 Dictionary of English using the @code{gcide} package.
27966 The following is an example @code{dicod-service} configuration.
27969 (dicod-service #:config
27970 (dicod-configuration
27971 (handlers (list (dicod-handler
27975 (list #~(string-append "dbdir=" #$wordnet))))))
27976 (databases (list (dicod-database
27979 (handler "wordnet")
27980 (options '("database=wn")))
27981 %dicod-database:gcide))))
27985 @subsubheading Docker Service
27987 The @code{(gnu services docker)} module provides the following services.
27989 @defvr {Scheme Variable} docker-service-type
27991 This is the type of the service that runs @url{https://www.docker.com,Docker},
27992 a daemon that can execute application bundles (sometimes referred to as
27993 ``containers'') in isolated environments.
27997 @deftp {Data Type} docker-configuration
27998 This is the data type representing the configuration of Docker and Containerd.
28002 @item @code{package} (default: @code{docker})
28003 The Docker daemon package to use.
28005 @item @code{package} (default: @code{docker-cli})
28006 The Docker client package to use.
28008 @item @code{containerd} (default: @var{containerd})
28009 The Containerd package to use.
28011 @item @code{proxy} (default @var{docker-libnetwork-cmd-proxy})
28012 The Docker user-land networking proxy package to use.
28014 @item @code{enable-proxy?} (default @code{#t})
28015 Enable or disable the use of the Docker user-land networking proxy.
28017 @item @code{debug?} (default @code{#f})
28018 Enable or disable debug output.
28020 @item @code{enable-iptables?} (default @code{#t})
28021 Enable or disable the addition of iptables rules.
28027 @subsubheading Auditd Service
28029 The @code{(gnu services auditd)} module provides the following service.
28031 @defvr {Scheme Variable} auditd-service-type
28033 This is the type of the service that runs
28034 @url{https://people.redhat.com/sgrubb/audit/,auditd},
28035 a daemon that tracks security-relevant information on your system.
28037 Examples of things that can be tracked:
28047 Failed login attempts
28054 @command{auditctl} from the @code{audit} package can be used in order
28055 to add or remove events to be tracked (until the next reboot).
28056 In order to permanently track events, put the command line arguments
28057 of auditctl into a file called @code{audit.rules} in the configuration
28058 directory (see below).
28059 @command{aureport} from the @code{audit} package can be used in order
28060 to view a report of all recorded events.
28061 The audit daemon by default logs into the file
28062 @file{/var/log/audit.log}.
28066 @deftp {Data Type} auditd-configuration
28067 This is the data type representing the configuration of auditd.
28071 @item @code{audit} (default: @code{audit})
28072 The audit package to use.
28074 @item @code{configuration-directory} (default: @code{%default-auditd-configuration-directory})
28075 The directory containing the configuration file for the audit package, which
28076 must be named @code{auditd.conf}, and optionally some audit rules to
28077 instantiate on startup.
28082 @defvr {Scheme Variable} singularity-service-type
28083 This is the type of the service that allows you to run
28084 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
28085 create and run application bundles (aka. ``containers''). The value for this
28086 service is the Singularity package to use.
28088 The service does not install a daemon; instead, it installs helper programs as
28089 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
28090 @command{singularity run} and similar commands.
28094 @subsubheading R-Shiny service
28096 The @code{(gnu services science)} module provides the following service.
28098 @defvr {Scheme Variable} rshiny-service-type
28100 This is a type of service which is used to run a webapp created with
28101 @code{r-shiny}. This service sets the @code{R_LIBS_USER} environment
28102 variable and runs the provided script to call @code{runApp}.
28104 @deftp {Data Type} rshiny-configuration
28105 This is the data type representing the configuration of rshiny.
28109 @item @code{package} (default: @code{r-shiny})
28110 The package to use.
28112 @item @code{binary} (defaunlt @code{"rshiny"})
28113 The name of the binary or shell script located at @code{package/bin/} to
28114 run when the service is run.
28116 The common way to create this file is as follows:
28120 (let* ((out (assoc-ref %outputs "out"))
28121 (targetdir (string-append out "/share/" ,name))
28122 (app (string-append out "/bin/" ,name))
28123 (Rbin (string-append (assoc-ref %build-inputs "r-min")
28126 (mkdir-p (string-append out "/bin"))
28127 (call-with-output-file app
28133 runApp(launch.browser=0, port=4202)~%\n"
28142 @subsubheading Nix service
28144 The @code{(gnu services nix)} module provides the following service.
28146 @defvr {Scheme Variable} nix-service-type
28148 This is the type of the service that runs build daemon of the
28149 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
28153 (use-modules (gnu))
28154 (use-service-modules nix)
28155 (use-package-modules package-management)
28159 (packages (append (list nix)
28162 (services (append (list (service nix-service-type))
28166 After @command{guix system reconfigure} configure Nix for your user:
28169 @item Add a Nix channel and update it. See
28170 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
28172 @item Create a symlink to your profile and activate Nix profile:
28176 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
28177 $ source /run/current-system/profile/etc/profile.d/nix.sh
28182 @deftp {Data Type} nix-configuration
28183 This data type represents the configuration of the Nix daemon.
28186 @item @code{nix} (default: @code{nix})
28187 The Nix package to use.
28189 @item @code{sandbox} (default: @code{#t})
28190 Specifies whether builds are sandboxed by default.
28192 @item @code{build-sandbox-items} (default: @code{'()})
28193 This is a list of strings or objects appended to the
28194 @code{build-sandbox-items} field of the configuration file.
28196 @item @code{extra-config} (default: @code{'()})
28197 This is a list of strings or objects appended to the configuration file.
28198 It is used to pass extra text to be added verbatim to the configuration
28201 @item @code{extra-options} (default: @code{'()})
28202 Extra command line options for @code{nix-service-type}.
28206 @node Setuid Programs
28207 @section Setuid Programs
28209 @cindex setuid programs
28210 Some programs need to run with ``root'' privileges, even when they are
28211 launched by unprivileged users. A notorious example is the
28212 @command{passwd} program, which users can run to change their
28213 password, and which needs to access the @file{/etc/passwd} and
28214 @file{/etc/shadow} files---something normally restricted to root, for
28215 obvious security reasons. To address that, these executables are
28216 @dfn{setuid-root}, meaning that they always run with root privileges
28217 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
28218 for more info about the setuid mechanism).
28220 The store itself @emph{cannot} contain setuid programs: that would be a
28221 security issue since any user on the system can write derivations that
28222 populate the store (@pxref{The Store}). Thus, a different mechanism is
28223 used: instead of changing the setuid bit directly on files that are in
28224 the store, we let the system administrator @emph{declare} which programs
28225 should be setuid root.
28227 The @code{setuid-programs} field of an @code{operating-system}
28228 declaration contains a list of G-expressions denoting the names of
28229 programs to be setuid-root (@pxref{Using the Configuration System}).
28230 For instance, the @command{passwd} program, which is part of the Shadow
28231 package, can be designated by this G-expression (@pxref{G-Expressions}):
28234 #~(string-append #$shadow "/bin/passwd")
28237 A default set of setuid programs is defined by the
28238 @code{%setuid-programs} variable of the @code{(gnu system)} module.
28240 @defvr {Scheme Variable} %setuid-programs
28241 A list of G-expressions denoting common programs that are setuid-root.
28243 The list includes commands such as @command{passwd}, @command{ping},
28244 @command{su}, and @command{sudo}.
28247 Under the hood, the actual setuid programs are created in the
28248 @file{/run/setuid-programs} directory at system activation time. The
28249 files in this directory refer to the ``real'' binaries, which are in the
28252 @node X.509 Certificates
28253 @section X.509 Certificates
28255 @cindex HTTPS, certificates
28256 @cindex X.509 certificates
28258 Web servers available over HTTPS (that is, HTTP over the transport-layer
28259 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
28260 that the client can then use to @emph{authenticate} the server. To do
28261 that, clients verify that the server's certificate is signed by a
28262 so-called @dfn{certificate authority} (CA). But to verify the CA's
28263 signature, clients must have first acquired the CA's certificate.
28265 Web browsers such as GNU@tie{}IceCat include their own set of CA
28266 certificates, such that they are able to verify CA signatures
28269 However, most other programs that can talk HTTPS---@command{wget},
28270 @command{git}, @command{w3m}, etc.---need to be told where CA
28271 certificates can be found.
28273 @cindex @code{nss-certs}
28274 In Guix, this is done by adding a package that provides certificates
28275 to the @code{packages} field of the @code{operating-system} declaration
28276 (@pxref{operating-system Reference}). Guix includes one such package,
28277 @code{nss-certs}, which is a set of CA certificates provided as part of
28278 Mozilla's Network Security Services.
28280 Note that it is @emph{not} part of @code{%base-packages}, so you need to
28281 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
28282 most applications and libraries look for certificates by default, points
28283 to the certificates installed globally.
28285 Unprivileged users, including users of Guix on a foreign distro,
28286 can also install their own certificate package in
28287 their profile. A number of environment variables need to be defined so
28288 that applications and libraries know where to find them. Namely, the
28289 OpenSSL library honors the @env{SSL_CERT_DIR} and @env{SSL_CERT_FILE}
28290 variables. Some applications add their own environment variables; for
28291 instance, the Git version control system honors the certificate bundle
28292 pointed to by the @env{GIT_SSL_CAINFO} environment variable. Thus, you
28293 would typically run something like:
28296 guix install nss-certs
28297 export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
28298 export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
28299 export GIT_SSL_CAINFO="$SSL_CERT_FILE"
28302 As another example, R requires the @env{CURL_CA_BUNDLE} environment
28303 variable to point to a certificate bundle, so you would have to run
28304 something like this:
28307 guix install nss-certs
28308 export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
28311 For other applications you may want to look up the required environment
28312 variable in the relevant documentation.
28315 @node Name Service Switch
28316 @section Name Service Switch
28318 @cindex name service switch
28320 The @code{(gnu system nss)} module provides bindings to the
28321 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
28322 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
28323 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
28324 extended with new ``name'' lookup methods for system databases, which
28325 includes host names, service names, user accounts, and more (@pxref{Name
28326 Service Switch, System Databases and Name Service Switch,, libc, The GNU
28327 C Library Reference Manual}).
28329 The NSS configuration specifies, for each system database, which lookup
28330 method is to be used, and how the various methods are chained
28331 together---for instance, under which circumstances NSS should try the
28332 next method in the list. The NSS configuration is given in the
28333 @code{name-service-switch} field of @code{operating-system} declarations
28334 (@pxref{operating-system Reference, @code{name-service-switch}}).
28337 @cindex .local, host name lookup
28338 As an example, the declaration below configures the NSS to use the
28339 @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
28340 back-end}, which supports host name lookups over multicast DNS (mDNS)
28341 for host names ending in @code{.local}:
28344 (name-service-switch
28345 (hosts (list %files ;first, check /etc/hosts
28347 ;; If the above did not succeed, try
28348 ;; with 'mdns_minimal'.
28350 (name "mdns_minimal")
28352 ;; 'mdns_minimal' is authoritative for
28353 ;; '.local'. When it returns "not found",
28354 ;; no need to try the next methods.
28355 (reaction (lookup-specification
28356 (not-found => return))))
28358 ;; Then fall back to DNS.
28362 ;; Finally, try with the "full" 'mdns'.
28367 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
28368 contains this configuration, so you will not have to type it if all you
28369 want is to have @code{.local} host lookup working.
28371 Note that, in this case, in addition to setting the
28372 @code{name-service-switch} of the @code{operating-system} declaration,
28373 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
28374 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
28375 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
28376 to the name service cache daemon (@pxref{Base Services,
28377 @code{nscd-service}}).
28379 For convenience, the following variables provide typical NSS
28382 @defvr {Scheme Variable} %default-nss
28383 This is the default name service switch configuration, a
28384 @code{name-service-switch} object.
28387 @defvr {Scheme Variable} %mdns-host-lookup-nss
28388 This is the name service switch configuration with support for host name
28389 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
28392 The reference for name service switch configuration is given below. It
28393 is a direct mapping of the configuration file format of the C library , so
28394 please refer to the C library manual for more information (@pxref{NSS
28395 Configuration File,,, libc, The GNU C Library Reference Manual}).
28396 Compared to the configuration file format of libc NSS, it has the advantage
28397 not only of adding this warm parenthetic feel that we like, but also
28398 static checks: you will know about syntax errors and typos as soon as you
28399 run @command{guix system}.
28401 @deftp {Data Type} name-service-switch
28403 This is the data type representation the configuration of libc's name
28404 service switch (NSS). Each field below represents one of the supported
28421 The system databases handled by the NSS. Each of these fields must be a
28422 list of @code{<name-service>} objects (see below).
28426 @deftp {Data Type} name-service
28428 This is the data type representing an actual name service and the
28429 associated lookup action.
28433 A string denoting the name service (@pxref{Services in the NSS
28434 configuration,,, libc, The GNU C Library Reference Manual}).
28436 Note that name services listed here must be visible to nscd. This is
28437 achieved by passing the @code{#:name-services} argument to
28438 @code{nscd-service} the list of packages providing the needed name
28439 services (@pxref{Base Services, @code{nscd-service}}).
28442 An action specified using the @code{lookup-specification} macro
28443 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
28444 Reference Manual}). For example:
28447 (lookup-specification (unavailable => continue)
28448 (success => return))
28453 @node Initial RAM Disk
28454 @section Initial RAM Disk
28457 @cindex initial RAM disk
28458 For bootstrapping purposes, the Linux-Libre kernel is passed an
28459 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
28460 root file system as well as an initialization script. The latter is
28461 responsible for mounting the real root file system, and for loading any
28462 kernel modules that may be needed to achieve that.
28464 The @code{initrd-modules} field of an @code{operating-system}
28465 declaration allows you to specify Linux-libre kernel modules that must
28466 be available in the initrd. In particular, this is where you would list
28467 modules needed to actually drive the hard disk where your root partition
28468 is---although the default value of @code{initrd-modules} should cover
28469 most use cases. For example, assuming you need the @code{megaraid_sas}
28470 module in addition to the default modules to be able to access your root
28471 file system, you would write:
28476 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
28479 @defvr {Scheme Variable} %base-initrd-modules
28480 This is the list of kernel modules included in the initrd by default.
28483 Furthermore, if you need lower-level customization, the @code{initrd}
28484 field of an @code{operating-system} declaration allows
28485 you to specify which initrd you would like to use. The @code{(gnu
28486 system linux-initrd)} module provides three ways to build an initrd: the
28487 high-level @code{base-initrd} procedure and the low-level
28488 @code{raw-initrd} and @code{expression->initrd} procedures.
28490 The @code{base-initrd} procedure is intended to cover most common uses.
28491 For example, if you want to add a bunch of kernel modules to be loaded
28492 at boot time, you can define the @code{initrd} field of the operating
28493 system declaration like this:
28496 (initrd (lambda (file-systems . rest)
28497 ;; Create a standard initrd but set up networking
28498 ;; with the parameters QEMU expects by default.
28499 (apply base-initrd file-systems
28500 #:qemu-networking? #t
28504 The @code{base-initrd} procedure also handles common use cases that
28505 involves using the system as a QEMU guest, or as a ``live'' system with
28506 volatile root file system.
28508 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
28509 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
28510 such as trying to guess which kernel modules and packages should be included
28511 to the initrd. An example use of @code{raw-initrd} is when a user has
28512 a custom Linux kernel configuration and default kernel modules included by
28513 @code{base-initrd} are not available.
28515 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
28516 honors several options passed on the Linux kernel command line
28517 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
28518 @code{-append} option of QEMU), notably:
28521 @item --load=@var{boot}
28522 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
28523 program, once it has mounted the root file system.
28525 Guix uses this option to yield control to a boot program that runs the
28526 service activation programs and then spawns the GNU@tie{}Shepherd, the
28527 initialization system.
28529 @item --root=@var{root}
28530 Mount @var{root} as the root file system. @var{root} can be a device
28531 name like @code{/dev/sda1}, a file system label, or a file system UUID.
28532 When unspecified, the device name from the root file system of the
28533 operating system declaration is used.
28535 @item --system=@var{system}
28536 Have @file{/run/booted-system} and @file{/run/current-system} point to
28539 @item modprobe.blacklist=@var{modules}@dots{}
28540 @cindex module, black-listing
28541 @cindex black list, of kernel modules
28542 Instruct the initial RAM disk as well as the @command{modprobe} command
28543 (from the kmod package) to refuse to load @var{modules}. @var{modules}
28544 must be a comma-separated list of module names---e.g.,
28545 @code{usbkbd,9pnet}.
28548 Start a read-eval-print loop (REPL) from the initial RAM disk before it
28549 tries to load kernel modules and to mount the root file system. Our
28550 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
28551 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
28552 Manual}, for more information on Guile's REPL.
28556 Now that you know all the features that initial RAM disks produced by
28557 @code{base-initrd} and @code{raw-initrd} provide,
28558 here is how to use it and customize it further.
28561 @cindex initial RAM disk
28562 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
28563 [#:linux-modules '()] [#:mapped-devices '()] @
28564 [#:keyboard-layout #f] @
28565 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
28566 Return a derivation that builds a raw initrd. @var{file-systems} is
28567 a list of file systems to be mounted by the initrd, possibly in addition to
28568 the root file system specified on the kernel command line via @option{--root}.
28569 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
28570 @var{mapped-devices} is a list of device mappings to realize before
28571 @var{file-systems} are mounted (@pxref{Mapped Devices}).
28572 @var{helper-packages} is a list of packages to be copied in the initrd. It may
28573 include @code{e2fsck/static} or other packages needed by the initrd to check
28574 the root file system.
28576 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
28577 the desired console keyboard layout. This is done before @var{mapped-devices}
28578 are set up and before @var{file-systems} are mounted such that, should the
28579 user need to enter a passphrase or use the REPL, this happens using the
28580 intended keyboard layout.
28582 When @var{qemu-networking?} is true, set up networking with the standard QEMU
28583 parameters. When @var{virtio?} is true, load additional modules so that the
28584 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
28586 When @var{volatile-root?} is true, the root file system is writable but any changes
28590 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
28591 [#:mapped-devices '()] [#:keyboard-layout #f] @
28592 [#:qemu-networking? #f] [#:volatile-root? #f] @
28593 [#:linux-modules '()]
28594 Return as a file-like object a generic initrd, with kernel
28595 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
28596 mounted by the initrd, possibly in addition to the root file system specified
28597 on the kernel command line via @option{--root}. @var{mapped-devices} is a list of device
28598 mappings to realize before @var{file-systems} are mounted.
28600 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
28601 the desired console keyboard layout. This is done before @var{mapped-devices}
28602 are set up and before @var{file-systems} are mounted such that, should the
28603 user need to enter a passphrase or use the REPL, this happens using the
28604 intended keyboard layout.
28606 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
28608 The initrd is automatically populated with all the kernel modules necessary
28609 for @var{file-systems} and for the given options. Additional kernel
28610 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
28611 loaded at boot time in the order in which they appear.
28614 Needless to say, the initrds we produce and use embed a
28615 statically-linked Guile, and the initialization program is a Guile
28616 program. That gives a lot of flexibility. The
28617 @code{expression->initrd} procedure builds such an initrd, given the
28618 program to run in that initrd.
28620 @deffn {Scheme Procedure} expression->initrd @var{exp} @
28621 [#:guile %guile-3.0-static-stripped] [#:name "guile-initrd"]
28622 Return as a file-like object a Linux initrd (a gzipped cpio archive)
28623 containing @var{guile} and that evaluates @var{exp}, a G-expression,
28624 upon booting. All the derivations referenced by @var{exp} are
28625 automatically copied to the initrd.
28628 @node Bootloader Configuration
28629 @section Bootloader Configuration
28632 @cindex boot loader
28634 The operating system supports multiple bootloaders. The bootloader is
28635 configured using @code{bootloader-configuration} declaration. All the
28636 fields of this structure are bootloader agnostic except for one field,
28637 @code{bootloader} that indicates the bootloader to be configured and
28640 Some of the bootloaders do not honor every field of
28641 @code{bootloader-configuration}. For instance, the extlinux
28642 bootloader does not support themes and thus ignores the @code{theme}
28645 @deftp {Data Type} bootloader-configuration
28646 The type of a bootloader configuration declaration.
28650 @item @code{bootloader}
28651 @cindex EFI, bootloader
28652 @cindex UEFI, bootloader
28653 @cindex BIOS, bootloader
28654 The bootloader to use, as a @code{bootloader} object. For now
28655 @code{grub-bootloader}, @code{grub-efi-bootloader},
28656 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
28658 @vindex grub-efi-bootloader
28659 @code{grub-efi-bootloader} allows to boot on modern systems using the
28660 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
28661 use if the installation image contains a @file{/sys/firmware/efi} directory
28662 when you boot it on your system.
28664 @vindex grub-bootloader
28665 @code{grub-bootloader} allows you to boot in particular Intel-based machines
28666 in ``legacy'' BIOS mode.
28668 @cindex ARM, bootloaders
28669 @cindex AArch64, bootloaders
28670 Available bootloaders are described in @code{(gnu bootloader @dots{})}
28671 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
28672 of bootloaders for a wide range of ARM and AArch64 systems, using the
28673 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
28675 @item @code{target}
28676 This is a string denoting the target onto which to install the
28679 The interpretation depends on the bootloader in question. For
28680 @code{grub-bootloader}, for example, it should be a device name understood by
28681 the bootloader @command{installer} command, such as @code{/dev/sda} or
28682 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
28683 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
28684 system, usually @file{/boot/efi}.
28686 @item @code{menu-entries} (default: @code{()})
28687 A possibly empty list of @code{menu-entry} objects (see below), denoting
28688 entries to appear in the bootloader menu, in addition to the current
28689 system entry and the entry pointing to previous system generations.
28691 @item @code{default-entry} (default: @code{0})
28692 The index of the default boot menu entry. Index 0 is for the entry of the
28695 @item @code{timeout} (default: @code{5})
28696 The number of seconds to wait for keyboard input before booting. Set to
28697 0 to boot immediately, and to -1 to wait indefinitely.
28699 @cindex keyboard layout, for the bootloader
28700 @item @code{keyboard-layout} (default: @code{#f})
28701 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
28702 layout, usually US@tie{}English (``qwerty'').
28704 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
28708 This option is currently ignored by bootloaders other than @code{grub} and
28712 @item @code{theme} (default: @var{#f})
28713 The bootloader theme object describing the theme to use. If no theme
28714 is provided, some bootloaders might use a default theme, that's true
28717 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
28718 The output terminals used for the bootloader boot menu, as a list of
28719 symbols. GRUB accepts the values: @code{console}, @code{serial},
28720 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
28721 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
28722 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
28723 configuration,,, grub,GNU GRUB manual}).
28725 @item @code{terminal-inputs} (default: @code{'()})
28726 The input terminals used for the bootloader boot menu, as a list of
28727 symbols. For GRUB, the default is the native platform terminal as
28728 determined at run-time. GRUB accepts the values: @code{console},
28729 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
28730 @code{usb_keyboard}. This field corresponds to the GRUB variable
28731 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
28734 @item @code{serial-unit} (default: @code{#f})
28735 The serial unit used by the bootloader, as an integer from 0 to 3.
28736 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
28737 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
28739 @item @code{serial-speed} (default: @code{#f})
28740 The speed of the serial interface, as an integer. For GRUB, the
28741 default value is chosen at run-time; currently GRUB chooses
28742 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
28749 Should you want to list additional boot menu entries @i{via} the
28750 @code{menu-entries} field above, you will need to create them with the
28751 @code{menu-entry} form. For example, imagine you want to be able to
28752 boot another distro (hard to imagine!), you can define a menu entry
28757 (label "The Other Distro")
28758 (linux "/boot/old/vmlinux-2.6.32")
28759 (linux-arguments '("root=/dev/sda2"))
28760 (initrd "/boot/old/initrd"))
28765 @deftp {Data Type} menu-entry
28766 The type of an entry in the bootloader menu.
28771 The label to show in the menu---e.g., @code{"GNU"}.
28773 @item @code{linux} (default: @code{#f})
28774 The Linux kernel image to boot, for example:
28777 (file-append linux-libre "/bzImage")
28780 For GRUB, it is also possible to specify a device explicitly in the
28781 file path using GRUB's device naming convention (@pxref{Naming
28782 convention,,, grub, GNU GRUB manual}), for example:
28785 "(hd0,msdos1)/boot/vmlinuz"
28788 If the device is specified explicitly as above, then the @code{device}
28789 field is ignored entirely.
28791 @item @code{linux-arguments} (default: @code{()})
28792 The list of extra Linux kernel command-line arguments---e.g.,
28793 @code{("console=ttyS0")}.
28795 @item @code{initrd} (default: @code{#f})
28796 A G-Expression or string denoting the file name of the initial RAM disk
28797 to use (@pxref{G-Expressions}).
28799 @item @code{device} (default: @code{#f})
28800 The device where the kernel and initrd are to be found---i.e., for GRUB,
28801 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
28803 This may be a file system label (a string), a file system UUID (a
28804 bytevector, @pxref{File Systems}), or @code{#f}, in which case
28805 the bootloader will search the device containing the file specified by
28806 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
28807 must @emph{not} be an OS device name such as @file{/dev/sda1}.
28809 @item @code{multiboot-kernel} (default: @code{#f})
28810 The kernel to boot in Multiboot-mode (@pxref{multiboot,,, grub, GNU GRUB
28811 manual}). When this field is set, a Multiboot menu-entry is generated.
28815 (file-append mach "/boot/gnumach")
28818 @item @code{multiboot-arguments} (default: @code{()})
28819 The list of extra command-line arguments for the multiboot-kernel.
28821 @item @code{multiboot-modules} (default: @code{()})
28822 The list of commands for loading Multiboot modules. For example:
28825 (list (list (file-append hurd "/hurd/ext2fs.static") "ext2fs"
28827 (list (file-append libc "/lib/ld.so.1") "exec"
28837 @c FIXME: Write documentation once it's stable.
28838 For now only GRUB has theme support. GRUB themes are created using
28839 the @code{grub-theme} form, which is not fully documented yet.
28841 @deftp {Data Type} grub-theme
28842 Data type representing the configuration of the GRUB theme.
28845 @item @code{gfxmode} (default: @code{'("auto")})
28846 The GRUB @code{gfxmode} to set (a list of screen resolution strings, see
28847 @pxref{gfxmode,,, grub, GNU GRUB manual}).
28851 @deffn {Scheme Procedure} grub-theme
28852 Return the default GRUB theme used by the operating system if no
28853 @code{theme} field is specified in @code{bootloader-configuration}
28856 It comes with a fancy background image displaying the GNU and Guix
28860 For example, to override the default resolution, you may use something
28865 (bootloader-configuration
28868 (inherit (grub-theme))
28869 (gfxmode '("1024x786x32" "auto"))))))
28872 @node Invoking guix system
28873 @section Invoking @code{guix system}
28875 Once you have written an operating system declaration as seen in the
28876 previous section, it can be @dfn{instantiated} using the @command{guix
28877 system} command. The synopsis is:
28880 guix system @var{options}@dots{} @var{action} @var{file}
28883 @var{file} must be the name of a file containing an
28884 @code{operating-system} declaration. @var{action} specifies how the
28885 operating system is instantiated. Currently the following values are
28890 Display available service type definitions that match the given regular
28891 expressions, sorted by relevance:
28897 $ guix system search console
28898 name: console-fonts
28899 location: gnu/services/base.scm:806:2
28900 extends: shepherd-root
28901 description: Install the given fonts on the specified ttys (fonts are per
28902 + virtual console on GNU/Linux). The value of this service is a list of
28903 + tty/font pairs. The font can be the name of a font provided by the `kbd'
28904 + package or any valid argument to `setfont', as in this example:
28906 + '(("tty1" . "LatGrkCyr-8x16")
28907 + ("tty2" . (file-append
28909 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
28910 + ("tty3" . (file-append
28912 + "/share/consolefonts/ter-132n"))) ; for HDPI
28916 location: gnu/services/base.scm:1190:2
28917 extends: shepherd-root
28918 description: Provide console login using the `mingetty' program.
28922 location: gnu/services/base.scm:860:2
28924 description: Provide a console log-in service as specified by its
28925 + configuration value, a `login-configuration' object.
28931 As for @command{guix package --search}, the result is written in
28932 @code{recutils} format, which makes it easy to filter the output
28933 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
28936 Build the operating system described in @var{file}, activate it, and
28937 switch to it@footnote{This action (and the related actions
28938 @code{switch-generation} and @code{roll-back}) are usable only on
28939 systems already running Guix System.}.
28942 @c The paragraph below refers to the problem discussed at
28943 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
28944 It is highly recommended to run @command{guix pull} once before you run
28945 @command{guix system reconfigure} for the first time (@pxref{Invoking
28946 guix pull}). Failing to do that you would see an older version of Guix
28947 once @command{reconfigure} has completed.
28950 This effects all the configuration specified in @var{file}: user
28951 accounts, system services, global package list, setuid programs, etc.
28952 The command starts system services specified in @var{file} that are not
28953 currently running; if a service is currently running this command will
28954 arrange for it to be upgraded the next time it is stopped (e.g.@: by
28955 @code{herd stop X} or @code{herd restart X}).
28957 This command creates a new generation whose number is one greater than
28958 the current generation (as reported by @command{guix system
28959 list-generations}). If that generation already exists, it will be
28960 overwritten. This behavior mirrors that of @command{guix package}
28961 (@pxref{Invoking guix package}).
28963 It also adds a bootloader menu entry for the new OS configuration,
28964 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
28965 entries for older configurations to a submenu, allowing you to choose
28966 an older system generation at boot time should you need it.
28968 @cindex provenance tracking, of the operating system
28969 Upon completion, the new system is deployed under
28970 @file{/run/current-system}. This directory contains @dfn{provenance
28971 meta-data}: the list of channels in use (@pxref{Channels}) and
28972 @var{file} itself, when available. You can view it by running:
28975 guix system describe
28978 This information is useful should you later want to inspect how this
28979 particular generation was built. In fact, assuming @var{file} is
28980 self-contained, you can later rebuild generation @var{n} of your
28981 operating system with:
28984 guix time-machine \
28985 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
28986 system reconfigure \
28987 /var/guix/profiles/system-@var{n}-link/configuration.scm
28990 You can think of it as some sort of built-in version control! Your
28991 system is not just a binary artifact: @emph{it carries its own source}.
28992 @xref{Service Reference, @code{provenance-service-type}}, for more
28993 information on provenance tracking.
28995 By default, @command{reconfigure} @emph{prevents you from downgrading
28996 your system}, which could (re)introduce security vulnerabilities and
28997 also cause problems with ``stateful'' services such as database
28998 management systems. You can override that behavior by passing
28999 @option{--allow-downgrades}.
29001 @item switch-generation
29002 @cindex generations
29003 Switch to an existing system generation. This action atomically
29004 switches the system profile to the specified system generation. It
29005 also rearranges the system's existing bootloader menu entries. It
29006 makes the menu entry for the specified system generation the default,
29007 and it moves the entries for the other generations to a submenu, if
29008 supported by the bootloader being used. The next time the system
29009 boots, it will use the specified system generation.
29011 The bootloader itself is not being reinstalled when using this
29012 command. Thus, the installed bootloader is used with an updated
29013 configuration file.
29015 The target generation can be specified explicitly by its generation
29016 number. For example, the following invocation would switch to system
29020 guix system switch-generation 7
29023 The target generation can also be specified relative to the current
29024 generation with the form @code{+N} or @code{-N}, where @code{+3} means
29025 ``3 generations ahead of the current generation,'' and @code{-1} means
29026 ``1 generation prior to the current generation.'' When specifying a
29027 negative value such as @code{-1}, you must precede it with @code{--} to
29028 prevent it from being parsed as an option. For example:
29031 guix system switch-generation -- -1
29034 Currently, the effect of invoking this action is @emph{only} to switch
29035 the system profile to an existing generation and rearrange the
29036 bootloader menu entries. To actually start using the target system
29037 generation, you must reboot after running this action. In the future,
29038 it will be updated to do the same things as @command{reconfigure},
29039 like activating and deactivating services.
29041 This action will fail if the specified generation does not exist.
29044 @cindex rolling back
29045 Switch to the preceding system generation. The next time the system
29046 boots, it will use the preceding system generation. This is the inverse
29047 of @command{reconfigure}, and it is exactly the same as invoking
29048 @command{switch-generation} with an argument of @code{-1}.
29050 Currently, as with @command{switch-generation}, you must reboot after
29051 running this action to actually start using the preceding system
29054 @item delete-generations
29055 @cindex deleting system generations
29056 @cindex saving space
29057 Delete system generations, making them candidates for garbage collection
29058 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
29061 This works in the same way as @samp{guix package --delete-generations}
29062 (@pxref{Invoking guix package, @option{--delete-generations}}). With no
29063 arguments, all system generations but the current one are deleted:
29066 guix system delete-generations
29069 You can also select the generations you want to delete. The example below
29070 deletes all the system generations that are more than two month old:
29073 guix system delete-generations 2m
29076 Running this command automatically reinstalls the bootloader with an updated
29077 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
29078 longer lists the generations that have been deleted.
29081 Build the derivation of the operating system, which includes all the
29082 configuration files and programs needed to boot and run the system.
29083 This action does not actually install anything.
29086 Populate the given directory with all the files necessary to run the
29087 operating system specified in @var{file}. This is useful for first-time
29088 installations of Guix System. For instance:
29091 guix system init my-os-config.scm /mnt
29094 copies to @file{/mnt} all the store items required by the configuration
29095 specified in @file{my-os-config.scm}. This includes configuration
29096 files, packages, and so on. It also creates other essential files
29097 needed for the system to operate correctly---e.g., the @file{/etc},
29098 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
29100 This command also installs bootloader on the target specified in
29101 @file{my-os-config}, unless the @option{--no-bootloader} option was
29105 @cindex virtual machine
29107 @anchor{guix system vm}
29108 Build a virtual machine that contains the operating system declared in
29109 @var{file}, and return a script to run that virtual machine (VM).
29112 The @code{vm} action and others below
29113 can use KVM support in the Linux-libre kernel. Specifically, if the
29114 machine has hardware virtualization support, the corresponding
29115 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
29116 must exist and be readable and writable by the user and by the
29117 build users of the daemon (@pxref{Build Environment Setup}).
29120 Arguments given to the script are passed to QEMU as in the example
29121 below, which enables networking and requests 1@tie{}GiB of RAM for the
29125 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
29128 The VM shares its store with the host system.
29130 Additional file systems can be shared between the host and the VM using
29131 the @option{--share} and @option{--expose} command-line options: the former
29132 specifies a directory to be shared with write access, while the latter
29133 provides read-only access to the shared directory.
29135 The example below creates a VM in which the user's home directory is
29136 accessible read-only, and where the @file{/exchange} directory is a
29137 read-write mapping of @file{$HOME/tmp} on the host:
29140 guix system vm my-config.scm \
29141 --expose=$HOME --share=$HOME/tmp=/exchange
29144 On GNU/Linux, the default is to boot directly to the kernel; this has
29145 the advantage of requiring only a very tiny root disk image since the
29146 store of the host can then be mounted.
29148 The @option{--full-boot} option forces a complete boot sequence, starting
29149 with the bootloader. This requires more disk space since a root image
29150 containing at least the kernel, initrd, and bootloader data files must
29151 be created. The @option{--image-size} option can be used to specify the
29154 @cindex System images, creation in various formats
29155 @cindex Creating system images in various formats
29158 @itemx docker-image
29159 Return a virtual machine, disk image, or Docker image of the operating
29160 system declared in @var{file} that stands alone. By default,
29161 @command{guix system} estimates the size of the image needed to store
29162 the system, but you can use the @option{--image-size} option to specify
29163 a value. Docker images are built to contain exactly what they need, so
29164 the @option{--image-size} option is ignored in the case of
29165 @code{docker-image}.
29167 You can specify the root file system type by using the
29168 @option{--file-system-type} option. It defaults to @code{ext4}. When its
29169 value is @code{iso9660}, the @option{--label} option can be used to specify
29170 a volume ID with @code{disk-image}.
29172 When using @code{vm-image}, the returned image is in qcow2 format, which
29173 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
29174 for more information on how to run the image in a virtual machine.
29176 When using @code{disk-image}, a raw disk image is produced; it can be
29177 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
29178 the device corresponding to a USB stick, one can copy the image to it
29179 using the following command:
29182 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc status=progress
29185 When using @code{docker-image}, a Docker image is produced. Guix builds
29186 the image from scratch, not from a pre-existing Docker base image. As a
29187 result, it contains @emph{exactly} what you define in the operating
29188 system configuration file. You can then load the image and launch a
29189 Docker container using commands like the following:
29192 image_id="`docker load < guix-system-docker-image.tar.gz`"
29193 container_id="`docker create $image_id`"
29194 docker start $container_id
29197 This command starts a new Docker container from the specified image. It
29198 will boot the Guix system in the usual manner, which means it will
29199 start any services you have defined in the operating system
29200 configuration. You can get an interactive shell running in the container
29201 using @command{docker exec}:
29204 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
29207 Depending on what you run in the Docker container, it
29208 may be necessary to give the container additional permissions. For
29209 example, if you intend to build software using Guix inside of the Docker
29210 container, you may need to pass the @option{--privileged} option to
29211 @code{docker create}.
29213 Last, the @option{--network} option applies to @command{guix system
29214 docker-image}: it produces an image where network is supposedly shared
29215 with the host, and thus without services like nscd or NetworkManager.
29218 Return a script to run the operating system declared in @var{file}
29219 within a container. Containers are a set of lightweight isolation
29220 mechanisms provided by the kernel Linux-libre. Containers are
29221 substantially less resource-demanding than full virtual machines since
29222 the kernel, shared objects, and other resources can be shared with the
29223 host system; this also means they provide thinner isolation.
29225 Currently, the script must be run as root in order to support more than
29226 a single user and group. The container shares its store with the host
29229 As with the @code{vm} action (@pxref{guix system vm}), additional file
29230 systems to be shared between the host and container can be specified
29231 using the @option{--share} and @option{--expose} options:
29234 guix system container my-config.scm \
29235 --expose=$HOME --share=$HOME/tmp=/exchange
29239 This option requires Linux-libre 3.19 or newer.
29244 @var{options} can contain any of the common build options (@pxref{Common
29245 Build Options}). In addition, @var{options} can contain one of the
29249 @item --expression=@var{expr}
29250 @itemx -e @var{expr}
29251 Consider the operating-system @var{expr} evaluates to.
29252 This is an alternative to specifying a file which evaluates to an
29254 This is used to generate the Guix system installer @pxref{Building the
29255 Installation Image}).
29257 @item --system=@var{system}
29258 @itemx -s @var{system}
29259 Attempt to build for @var{system} instead of the host system type.
29260 This works as per @command{guix build} (@pxref{Invoking guix build}).
29264 Return the derivation file name of the given operating system without
29267 @cindex provenance tracking, of the operating system
29268 @item --save-provenance
29269 As discussed above, @command{guix system init} and @command{guix system
29270 reconfigure} always save provenance information @i{via} a dedicated
29271 service (@pxref{Service Reference, @code{provenance-service-type}}).
29272 However, other commands don't do that by default. If you wish to, say,
29273 create a virtual machine image that contains provenance information, you
29277 guix system vm-image --save-provenance config.scm
29280 That way, the resulting image will effectively ``embed its own source''
29281 in the form of meta-data in @file{/run/current-system}. With that
29282 information, one can rebuild the image to make sure it really contains
29283 what it pretends to contain; or they could use that to derive a variant
29286 @item --file-system-type=@var{type}
29287 @itemx -t @var{type}
29288 For the @code{disk-image} action, create a file system of the given
29289 @var{type} on the image.
29291 When this option is omitted, @command{guix system} uses @code{ext4}.
29293 @cindex ISO-9660 format
29294 @cindex CD image format
29295 @cindex DVD image format
29296 @option{--file-system-type=iso9660} produces an ISO-9660 image, suitable
29297 for burning on CDs and DVDs.
29299 @item --image-size=@var{size}
29300 For the @code{vm-image} and @code{disk-image} actions, create an image
29301 of the given @var{size}. @var{size} may be a number of bytes, or it may
29302 include a unit as a suffix (@pxref{Block size, size specifications,,
29303 coreutils, GNU Coreutils}).
29305 When this option is omitted, @command{guix system} computes an estimate
29306 of the image size as a function of the size of the system declared in
29311 For the @code{container} action, allow containers to access the host network,
29312 that is, do not create a network namespace.
29314 @item --root=@var{file}
29315 @itemx -r @var{file}
29316 Make @var{file} a symlink to the result, and register it as a garbage
29319 @item --skip-checks
29320 Skip pre-installation safety checks.
29322 By default, @command{guix system init} and @command{guix system
29323 reconfigure} perform safety checks: they make sure the file systems that
29324 appear in the @code{operating-system} declaration actually exist
29325 (@pxref{File Systems}), and that any Linux kernel modules that may be
29326 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
29327 RAM Disk}). Passing this option skips these tests altogether.
29329 @item --allow-downgrades
29330 Instruct @command{guix system reconfigure} to allow system downgrades.
29332 By default, @command{reconfigure} prevents you from downgrading your
29333 system. It achieves that by comparing the provenance info of your
29334 system (shown by @command{guix system describe}) with that of your
29335 @command{guix} command (shown by @command{guix describe}). If the
29336 commits for @command{guix} are not descendants of those used for your
29337 system, @command{guix system reconfigure} errors out. Passing
29338 @option{--allow-downgrades} allows you to bypass these checks.
29341 Make sure you understand its security implications before using
29342 @option{--allow-downgrades}.
29346 @cindex on-error strategy
29347 @cindex error strategy
29348 @item --on-error=@var{strategy}
29349 Apply @var{strategy} when an error occurs when reading @var{file}.
29350 @var{strategy} may be one of the following:
29353 @item nothing-special
29354 Report the error concisely and exit. This is the default strategy.
29357 Likewise, but also display a backtrace.
29360 Report the error and enter Guile's debugger. From there, you can run
29361 commands such as @code{,bt} to get a backtrace, @code{,locals} to
29362 display local variable values, and more generally inspect the state of the
29363 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
29364 a list of available debugging commands.
29368 Once you have built, configured, re-configured, and re-re-configured
29369 your Guix installation, you may find it useful to list the operating
29370 system generations available on disk---and that you can choose from the
29371 bootloader boot menu:
29376 Describe the current system generation: its file name, the kernel and
29377 bootloader used, etc., as well as provenance information when available.
29379 @item list-generations
29380 List a summary of each generation of the operating system available on
29381 disk, in a human-readable way. This is similar to the
29382 @option{--list-generations} option of @command{guix package}
29383 (@pxref{Invoking guix package}).
29385 Optionally, one can specify a pattern, with the same syntax that is used
29386 in @command{guix package --list-generations}, to restrict the list of
29387 generations displayed. For instance, the following command displays
29388 generations that are up to 10 days old:
29391 $ guix system list-generations 10d
29396 The @command{guix system} command has even more to offer! The following
29397 sub-commands allow you to visualize how your system services relate to
29400 @anchor{system-extension-graph}
29403 @item extension-graph
29404 Emit in Dot/Graphviz format to standard output the @dfn{service
29405 extension graph} of the operating system defined in @var{file}
29406 (@pxref{Service Composition}, for more information on service
29412 $ guix system extension-graph @var{file} | xdot -
29415 shows the extension relations among services.
29417 @anchor{system-shepherd-graph}
29418 @item shepherd-graph
29419 Emit in Dot/Graphviz format to standard output the @dfn{dependency
29420 graph} of shepherd services of the operating system defined in
29421 @var{file}. @xref{Shepherd Services}, for more information and for an
29426 @node Invoking guix deploy
29427 @section Invoking @code{guix deploy}
29429 We've already seen @code{operating-system} declarations used to manage a
29430 machine's configuration locally. Suppose you need to configure multiple
29431 machines, though---perhaps you're managing a service on the web that's
29432 comprised of several servers. @command{guix deploy} enables you to use those
29433 same @code{operating-system} declarations to manage multiple remote hosts at
29434 once as a logical ``deployment''.
29437 The functionality described in this section is still under development
29438 and is subject to change. Get in touch with us on
29439 @email{guix-devel@@gnu.org}!
29443 guix deploy @var{file}
29446 Such an invocation will deploy the machines that the code within @var{file}
29447 evaluates to. As an example, @var{file} might contain a definition like this:
29450 ;; This is a Guix deployment of a "bare bones" setup, with
29451 ;; no X11 display server, to a machine with an SSH daemon
29452 ;; listening on localhost:2222. A configuration such as this
29453 ;; may be appropriate for virtual machine with ports
29454 ;; forwarded to the host's loopback interface.
29456 (use-service-modules networking ssh)
29457 (use-package-modules bootloaders)
29461 (host-name "gnu-deployed")
29462 (timezone "Etc/UTC")
29463 (bootloader (bootloader-configuration
29464 (bootloader grub-bootloader)
29465 (target "/dev/vda")
29466 (terminal-outputs '(console))))
29467 (file-systems (cons (file-system
29469 (device "/dev/vda1")
29471 %base-file-systems))
29473 (append (list (service dhcp-client-service-type)
29474 (service openssh-service-type
29475 (openssh-configuration
29476 (permit-root-login #t)
29477 (allow-empty-passwords? #t))))
29481 (operating-system %system)
29482 (environment managed-host-environment-type)
29483 (configuration (machine-ssh-configuration
29484 (host-name "localhost")
29485 (system "x86_64-linux")
29487 (identity "./id_rsa")
29491 The file should evaluate to a list of @var{machine} objects. This example,
29492 upon being deployed, will create a new generation on the remote system
29493 realizing the @code{operating-system} declaration @code{%system}.
29494 @code{environment} and @code{configuration} specify how the machine should be
29495 provisioned---that is, how the computing resources should be created and
29496 managed. The above example does not create any resources, as a
29497 @code{'managed-host} is a machine that is already running the Guix system and
29498 available over the network. This is a particularly simple case; a more
29499 complex deployment may involve, for example, starting virtual machines through
29500 a Virtual Private Server (VPS) provider. In such a case, a different
29501 @var{environment} type would be used.
29503 Do note that you first need to generate a key pair on the coordinator machine
29504 to allow the daemon to export signed archives of files from the store
29505 (@pxref{Invoking guix archive}).
29508 # guix archive --generate-key
29512 Each target machine must authorize the key of the master machine so that it
29513 accepts store items it receives from the coordinator:
29516 # guix archive --authorize < coordinator-public-key.txt
29519 @code{user}, in this example, specifies the name of the user account to log in
29520 as to perform the deployment. Its default value is @code{root}, but root
29521 login over SSH may be forbidden in some cases. To work around this,
29522 @command{guix deploy} can log in as an unprivileged user and employ
29523 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
29524 currently installed on the remote and can be invoked non-interactively as
29525 @code{user}. That is, the line in @code{sudoers} granting @code{user} the
29526 ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
29527 be accomplished with the following operating system configuration snippet:
29531 (gnu system)) ;for %sudoers-specification
29533 (define %user "username")
29538 (plain-file "sudoers"
29539 (string-append (plain-file-content %sudoers-specification)
29540 (format #f "~a ALL = NOPASSWD: ALL~%"
29545 For more information regarding the format of the @file{sudoers} file,
29546 consult @command{man sudoers}.
29548 @deftp {Data Type} machine
29549 This is the data type representing a single machine in a heterogeneous Guix
29553 @item @code{operating-system}
29554 The object of the operating system configuration to deploy.
29556 @item @code{environment}
29557 An @code{environment-type} describing how the machine should be provisioned.
29559 @item @code{configuration} (default: @code{#f})
29560 An object describing the configuration for the machine's @code{environment}.
29561 If the @code{environment} has a default configuration, @code{#f} may be used.
29562 If @code{#f} is used for an environment with no default configuration,
29563 however, an error will be thrown.
29567 @deftp {Data Type} machine-ssh-configuration
29568 This is the data type representing the SSH client parameters for a machine
29569 with an @code{environment} of @code{managed-host-environment-type}.
29572 @item @code{host-name}
29573 @item @code{build-locally?} (default: @code{#t})
29574 If false, system derivations will be built on the machine being deployed to.
29575 @item @code{system}
29576 The system type describing the architecture of the machine being deployed
29577 to---e.g., @code{"x86_64-linux"}.
29578 @item @code{authorize?} (default: @code{#t})
29579 If true, the coordinator's signing key will be added to the remote's ACL
29581 @item @code{port} (default: @code{22})
29582 @item @code{user} (default: @code{"root"})
29583 @item @code{identity} (default: @code{#f})
29584 If specified, the path to the SSH private key to use to authenticate with the
29587 @item @code{host-key} (default: @code{#f})
29588 This should be the SSH host key of the machine, which looks like this:
29591 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
29594 When @code{host-key} is @code{#f}, the server is authenticated against
29595 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
29598 @item @code{allow-downgrades?} (default: @code{#f})
29599 Whether to allow potential downgrades.
29601 Like @command{guix system reconfigure}, @command{guix deploy} compares
29602 the channel commits currently deployed on the remote host (as returned
29603 by @command{guix system describe}) to those currently in use (as
29604 returned by @command{guix describe}) to determine whether commits
29605 currently in use are descendants of those deployed. When this is not
29606 the case and @code{allow-downgrades?} is false, it raises an error.
29607 This ensures you do not accidentally downgrade remote machines.
29611 @deftp {Data Type} digital-ocean-configuration
29612 This is the data type describing the Droplet that should be created for a
29613 machine with an @code{environment} of @code{digital-ocean-environment-type}.
29616 @item @code{ssh-key}
29617 The path to the SSH private key to use to authenticate with the remote
29618 host. In the future, this field may not exist.
29620 A list of string ``tags'' that uniquely identify the machine. Must be given
29621 such that no two machines in the deployment have the same set of tags.
29622 @item @code{region}
29623 A Digital Ocean region slug, such as @code{"nyc3"}.
29625 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
29626 @item @code{enable-ipv6?}
29627 Whether or not the droplet should be created with IPv6 networking.
29631 @node Running Guix in a VM
29632 @section Running Guix in a Virtual Machine
29634 @cindex virtual machine
29635 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
29637 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
29638 This image is a compressed image in QCOW format. You will first need to
29639 decompress with @command{xz -d}, and then you can pass it to an emulator such
29640 as QEMU (see below for details).
29642 This image boots the Xfce graphical environment and it contains some
29643 commonly-used tools. You can install more software in the image by running
29644 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
29645 also reconfigure the system based on its initial configuration file available
29646 as @file{/run/current-system/configuration.scm} (@pxref{Using the
29647 Configuration System}).
29649 Instead of using this pre-built image, one can also build their own virtual
29650 machine image using @command{guix system vm-image} (@pxref{Invoking guix
29651 system}). The returned image is in qcow2 format, which the
29652 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
29655 If you built your own image, you must copy it out of the store
29656 (@pxref{The Store}) and give yourself permission to write to the copy
29657 before you can use it. When invoking QEMU, you must choose a system
29658 emulator that is suitable for your hardware platform. Here is a minimal
29659 QEMU invocation that will boot the result of @command{guix system
29660 vm-image} on x86_64 hardware:
29663 $ qemu-system-x86_64 \
29664 -nic user,model=virtio-net-pci \
29665 -enable-kvm -m 1024 \
29666 -device virtio-blk,drive=myhd \
29667 -drive if=none,file=/tmp/qemu-image,id=myhd
29670 Here is what each of these options means:
29673 @item qemu-system-x86_64
29674 This specifies the hardware platform to emulate. This should match the
29677 @item -nic user,model=virtio-net-pci
29678 Enable the unprivileged user-mode network stack. The guest OS can
29679 access the host but not vice versa. This is the simplest way to get the
29680 guest OS online. @code{model} specifies which network device to emulate:
29681 @code{virtio-net-pci} is a special device made for virtualized operating
29682 systems and recommended for most uses. Assuming your hardware platform is
29683 x86_64, you can get a list of available NIC models by running
29684 @command{qemu-system-x86_64 -nic model=help}.
29687 If your system has hardware virtualization extensions, enabling the
29688 virtual machine support (KVM) of the Linux kernel will make things run
29691 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
29693 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
29694 which may be insufficient for some operations.
29696 @item -device virtio-blk,drive=myhd
29697 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
29698 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
29699 better performance than if it were emulating a complete disk drive. See the
29700 QEMU and KVM documentation for more info.
29702 @item -drive if=none,file=/tmp/qemu-image,id=myhd
29703 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
29704 the ``myhd'' drive.
29707 The default @command{run-vm.sh} script that is returned by an invocation of
29708 @command{guix system vm} does not add a @command{-nic user} flag by default.
29709 To get network access from within the vm add the @code{(dhcp-client-service)}
29710 to your system definition and start the VM using
29711 @command{`guix system vm config.scm` -nic user}. An important caveat of using
29712 @command{-nic user} for networking is that @command{ping} will not work, because
29713 it uses the ICMP protocol. You'll have to use a different command to check for
29714 network connectivity, for example @command{guix download}.
29716 @subsection Connecting Through SSH
29720 To enable SSH inside a VM you need to add an SSH server like
29721 @code{openssh-service-type} to your VM (@pxref{Networking Services,
29722 @code{openssh-service-type}}). In addition you need to forward the SSH port,
29723 22 by default, to the host. You can do this with
29726 `guix system vm config.scm` -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
29729 To connect to the VM you can run
29732 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
29735 The @command{-p} tells @command{ssh} the port you want to connect to.
29736 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
29737 every time you modify your @command{config.scm} file and the
29738 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
29739 connection to an unknown host every time you connect.
29741 @subsection Using @command{virt-viewer} with Spice
29743 As an alternative to the default @command{qemu} graphical client you can
29744 use the @command{remote-viewer} from the @command{virt-viewer} package. To
29745 connect pass the @command{-spice port=5930,disable-ticketing} flag to
29746 @command{qemu}. See previous section for further information on how to do this.
29748 Spice also allows you to do some nice stuff like share your clipboard with your
29749 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
29752 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
29753 -chardev spicevmc,name=vdagent,id=vdagent
29754 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
29755 name=com.redhat.spice.0
29758 You'll also need to add the @code{(spice-vdagent-service)} to your
29759 system definition (@pxref{Miscellaneous Services, Spice service}).
29761 @node Defining Services
29762 @section Defining Services
29764 The previous sections show the available services and how one can combine
29765 them in an @code{operating-system} declaration. But how do we define
29766 them in the first place? And what is a service anyway?
29769 * Service Composition:: The model for composing services.
29770 * Service Types and Services:: Types and services.
29771 * Service Reference:: API reference.
29772 * Shepherd Services:: A particular type of service.
29775 @node Service Composition
29776 @subsection Service Composition
29780 Here we define a @dfn{service} as, broadly, something that extends the
29781 functionality of the operating system. Often a service is a process---a
29782 @dfn{daemon}---started when the system boots: a secure shell server, a
29783 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
29784 whose execution can be triggered by another daemon---e.g., an FTP server
29785 started by @command{inetd} or a D-Bus service activated by
29786 @command{dbus-daemon}. Occasionally, a service does not map to a
29787 daemon. For instance, the ``account'' service collects user accounts
29788 and makes sure they exist when the system runs; the ``udev'' service
29789 collects device management rules and makes them available to the eudev
29790 daemon; the @file{/etc} service populates the @file{/etc} directory
29793 @cindex service extensions
29794 Guix system services are connected by @dfn{extensions}. For instance, the
29795 secure shell service @emph{extends} the Shepherd---the
29796 initialization system, running as PID@tie{}1---by giving it the command
29797 lines to start and stop the secure shell daemon (@pxref{Networking
29798 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
29799 service by passing it its @file{.service} specification, and extends the
29800 udev service by passing it device management rules (@pxref{Desktop
29801 Services, @code{upower-service}}); the Guix daemon service extends the
29802 Shepherd by passing it the command lines to start and stop the daemon,
29803 and extends the account service by passing it a list of required build
29804 user accounts (@pxref{Base Services}).
29806 All in all, services and their ``extends'' relations form a directed
29807 acyclic graph (DAG). If we represent services as boxes and extensions
29808 as arrows, a typical system might provide something like this:
29810 @image{images/service-graph,,5in,Typical service extension graph.}
29812 @cindex system service
29813 At the bottom, we see the @dfn{system service}, which produces the
29814 directory containing everything to run and boot the system, as returned
29815 by the @command{guix system build} command. @xref{Service Reference},
29816 to learn about the other service types shown here.
29817 @xref{system-extension-graph, the @command{guix system extension-graph}
29818 command}, for information on how to generate this representation for a
29819 particular operating system definition.
29821 @cindex service types
29822 Technically, developers can define @dfn{service types} to express these
29823 relations. There can be any number of services of a given type on the
29824 system---for instance, a system running two instances of the GNU secure
29825 shell server (lsh) has two instances of @code{lsh-service-type}, with
29826 different parameters.
29828 The following section describes the programming interface for service
29829 types and services.
29831 @node Service Types and Services
29832 @subsection Service Types and Services
29834 A @dfn{service type} is a node in the DAG described above. Let us start
29835 with a simple example, the service type for the Guix build daemon
29836 (@pxref{Invoking guix-daemon}):
29839 (define guix-service-type
29843 (list (service-extension shepherd-root-service-type guix-shepherd-service)
29844 (service-extension account-service-type guix-accounts)
29845 (service-extension activation-service-type guix-activation)))
29846 (default-value (guix-configuration))))
29850 It defines three things:
29854 A name, whose sole purpose is to make inspection and debugging easier.
29857 A list of @dfn{service extensions}, where each extension designates the
29858 target service type and a procedure that, given the parameters of the
29859 service, returns a list of objects to extend the service of that type.
29861 Every service type has at least one service extension. The only
29862 exception is the @dfn{boot service type}, which is the ultimate service.
29865 Optionally, a default value for instances of this type.
29868 In this example, @code{guix-service-type} extends three services:
29871 @item shepherd-root-service-type
29872 The @code{guix-shepherd-service} procedure defines how the Shepherd
29873 service is extended. Namely, it returns a @code{<shepherd-service>}
29874 object that defines how @command{guix-daemon} is started and stopped
29875 (@pxref{Shepherd Services}).
29877 @item account-service-type
29878 This extension for this service is computed by @code{guix-accounts},
29879 which returns a list of @code{user-group} and @code{user-account}
29880 objects representing the build user accounts (@pxref{Invoking
29883 @item activation-service-type
29884 Here @code{guix-activation} is a procedure that returns a gexp, which is
29885 a code snippet to run at ``activation time''---e.g., when the service is
29889 A service of this type is instantiated like this:
29892 (service guix-service-type
29893 (guix-configuration
29895 (use-substitutes? #f)))
29898 The second argument to the @code{service} form is a value representing
29899 the parameters of this specific service instance.
29900 @xref{guix-configuration-type, @code{guix-configuration}}, for
29901 information about the @code{guix-configuration} data type. When the
29902 value is omitted, the default value specified by
29903 @code{guix-service-type} is used:
29906 (service guix-service-type)
29909 @code{guix-service-type} is quite simple because it extends other
29910 services but is not extensible itself.
29912 @c @subsubsubsection Extensible Service Types
29914 The service type for an @emph{extensible} service looks like this:
29917 (define udev-service-type
29918 (service-type (name 'udev)
29920 (list (service-extension shepherd-root-service-type
29921 udev-shepherd-service)))
29923 (compose concatenate) ;concatenate the list of rules
29924 (extend (lambda (config rules)
29926 (($ <udev-configuration> udev initial-rules)
29927 (udev-configuration
29928 (udev udev) ;the udev package to use
29929 (rules (append initial-rules rules)))))))))
29932 This is the service type for the
29933 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
29934 management daemon}. Compared to the previous example, in addition to an
29935 extension of @code{shepherd-root-service-type}, we see two new fields:
29939 This is the procedure to @dfn{compose} the list of extensions to
29940 services of this type.
29942 Services can extend the udev service by passing it lists of rules; we
29943 compose those extensions simply by concatenating them.
29946 This procedure defines how the value of the service is @dfn{extended} with
29947 the composition of the extensions.
29949 Udev extensions are composed into a list of rules, but the udev service
29950 value is itself a @code{<udev-configuration>} record. So here, we
29951 extend that record by appending the list of rules it contains to the
29952 list of contributed rules.
29955 This is a string giving an overview of the service type. The string can
29956 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
29957 @command{guix system search} command searches these strings and displays
29958 them (@pxref{Invoking guix system}).
29961 There can be only one instance of an extensible service type such as
29962 @code{udev-service-type}. If there were more, the
29963 @code{service-extension} specifications would be ambiguous.
29965 Still here? The next section provides a reference of the programming
29966 interface for services.
29968 @node Service Reference
29969 @subsection Service Reference
29971 We have seen an overview of service types (@pxref{Service Types and
29972 Services}). This section provides a reference on how to manipulate
29973 services and service types. This interface is provided by the
29974 @code{(gnu services)} module.
29976 @deffn {Scheme Procedure} service @var{type} [@var{value}]
29977 Return a new service of @var{type}, a @code{<service-type>} object (see
29978 below). @var{value} can be any object; it represents the parameters of
29979 this particular service instance.
29981 When @var{value} is omitted, the default value specified by @var{type}
29982 is used; if @var{type} does not specify a default value, an error is
29985 For instance, this:
29988 (service openssh-service-type)
29992 is equivalent to this:
29995 (service openssh-service-type
29996 (openssh-configuration))
29999 In both cases the result is an instance of @code{openssh-service-type}
30000 with the default configuration.
30003 @deffn {Scheme Procedure} service? @var{obj}
30004 Return true if @var{obj} is a service.
30007 @deffn {Scheme Procedure} service-kind @var{service}
30008 Return the type of @var{service}---i.e., a @code{<service-type>} object.
30011 @deffn {Scheme Procedure} service-value @var{service}
30012 Return the value associated with @var{service}. It represents its
30016 Here is an example of how a service is created and manipulated:
30020 (service nginx-service-type
30021 (nginx-configuration
30023 (log-directory log-directory)
30024 (run-directory run-directory)
30025 (file config-file))))
30030 (eq? (service-kind s) nginx-service-type)
30034 The @code{modify-services} form provides a handy way to change the
30035 parameters of some of the services of a list such as
30036 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
30037 evaluates to a list of services. Of course, you could always use
30038 standard list combinators such as @code{map} and @code{fold} to do that
30039 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
30040 @code{modify-services} simply provides a more concise form for this
30043 @deffn {Scheme Syntax} modify-services @var{services} @
30044 (@var{type} @var{variable} => @var{body}) @dots{}
30046 Modify the services listed in @var{services} according to the given
30047 clauses. Each clause has the form:
30050 (@var{type} @var{variable} => @var{body})
30053 where @var{type} is a service type---e.g.,
30054 @code{guix-service-type}---and @var{variable} is an identifier that is
30055 bound within the @var{body} to the service parameters---e.g., a
30056 @code{guix-configuration} instance---of the original service of that
30059 The @var{body} should evaluate to the new service parameters, which will
30060 be used to configure the new service. This new service will replace the
30061 original in the resulting list. Because a service's service parameters
30062 are created using @code{define-record-type*}, you can write a succinct
30063 @var{body} that evaluates to the new service parameters by using the
30064 @code{inherit} feature that @code{define-record-type*} provides.
30066 @xref{Using the Configuration System}, for example usage.
30070 Next comes the programming interface for service types. This is
30071 something you want to know when writing new service definitions, but not
30072 necessarily when simply looking for ways to customize your
30073 @code{operating-system} declaration.
30075 @deftp {Data Type} service-type
30076 @cindex service type
30077 This is the representation of a @dfn{service type} (@pxref{Service Types
30082 This is a symbol, used only to simplify inspection and debugging.
30084 @item @code{extensions}
30085 A non-empty list of @code{<service-extension>} objects (see below).
30087 @item @code{compose} (default: @code{#f})
30088 If this is @code{#f}, then the service type denotes services that cannot
30089 be extended---i.e., services that do not receive ``values'' from other
30092 Otherwise, it must be a one-argument procedure. The procedure is called
30093 by @code{fold-services} and is passed a list of values collected from
30094 extensions. It may return any single value.
30096 @item @code{extend} (default: @code{#f})
30097 If this is @code{#f}, services of this type cannot be extended.
30099 Otherwise, it must be a two-argument procedure: @code{fold-services}
30100 calls it, passing it the initial value of the service as the first
30101 argument and the result of applying @code{compose} to the extension
30102 values as the second argument. It must return a value that is a valid
30103 parameter value for the service instance.
30105 @item @code{description}
30106 This is a string, possibly using Texinfo markup, describing in a couple
30107 of sentences what the service is about. This string allows users to
30108 find about the service through @command{guix system search}
30109 (@pxref{Invoking guix system}).
30111 @item @code{default-value} (default: @code{&no-default-value})
30112 The default value associated for instances of this service type. This
30113 allows users to use the @code{service} form without its second argument:
30116 (service @var{type})
30119 The returned service in this case has the default value specified by
30123 @xref{Service Types and Services}, for examples.
30126 @deffn {Scheme Procedure} service-extension @var{target-type} @
30128 Return a new extension for services of type @var{target-type}.
30129 @var{compute} must be a one-argument procedure: @code{fold-services}
30130 calls it, passing it the value associated with the service that provides
30131 the extension; it must return a valid value for the target service.
30134 @deffn {Scheme Procedure} service-extension? @var{obj}
30135 Return true if @var{obj} is a service extension.
30138 Occasionally, you might want to simply extend an existing service. This
30139 involves creating a new service type and specifying the extension of
30140 interest, which can be verbose; the @code{simple-service} procedure
30141 provides a shorthand for this.
30143 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
30144 Return a service that extends @var{target} with @var{value}. This works
30145 by creating a singleton service type @var{name}, of which the returned
30146 service is an instance.
30148 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
30152 (simple-service 'my-mcron-job mcron-service-type
30153 #~(job '(next-hour (3)) "guix gc -F 2G"))
30157 At the core of the service abstraction lies the @code{fold-services}
30158 procedure, which is responsible for ``compiling'' a list of services
30159 down to a single directory that contains everything needed to boot and
30160 run the system---the directory shown by the @command{guix system build}
30161 command (@pxref{Invoking guix system}). In essence, it propagates
30162 service extensions down the service graph, updating each node parameters
30163 on the way, until it reaches the root node.
30165 @deffn {Scheme Procedure} fold-services @var{services} @
30166 [#:target-type @var{system-service-type}]
30167 Fold @var{services} by propagating their extensions down to the root of
30168 type @var{target-type}; return the root service adjusted accordingly.
30171 Lastly, the @code{(gnu services)} module also defines several essential
30172 service types, some of which are listed below.
30174 @defvr {Scheme Variable} system-service-type
30175 This is the root of the service graph. It produces the system directory
30176 as returned by the @command{guix system build} command.
30179 @defvr {Scheme Variable} boot-service-type
30180 The type of the ``boot service'', which produces the @dfn{boot script}.
30181 The boot script is what the initial RAM disk runs when booting.
30184 @defvr {Scheme Variable} etc-service-type
30185 The type of the @file{/etc} service. This service is used to create
30186 files under @file{/etc} and can be extended by
30187 passing it name/file tuples such as:
30190 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
30193 In this example, the effect would be to add an @file{/etc/issue} file
30194 pointing to the given file.
30197 @defvr {Scheme Variable} setuid-program-service-type
30198 Type for the ``setuid-program service''. This service collects lists of
30199 executable file names, passed as gexps, and adds them to the set of
30200 setuid-root programs on the system (@pxref{Setuid Programs}).
30203 @defvr {Scheme Variable} profile-service-type
30204 Type of the service that populates the @dfn{system profile}---i.e., the
30205 programs under @file{/run/current-system/profile}. Other services can
30206 extend it by passing it lists of packages to add to the system profile.
30209 @cindex provenance tracking, of the operating system
30210 @anchor{provenance-service-type}
30211 @defvr {Scheme Variable} provenance-service-type
30212 This is the type of the service that records @dfn{provenance meta-data}
30213 in the system itself. It creates several files under
30214 @file{/run/current-system}:
30218 This is a ``channel file'' that can be passed to @command{guix pull -C}
30219 or @command{guix time-machine -C}, and which describes the channels used
30220 to build the system, if that information was available
30221 (@pxref{Channels}).
30223 @item configuration.scm
30224 This is the file that was passed as the value for this
30225 @code{provenance-service-type} service. By default, @command{guix
30226 system reconfigure} automatically passes the OS configuration file it
30227 received on the command line.
30230 This contains the same information as the two other files but in a
30231 format that is more readily processable.
30234 In general, these two pieces of information (channels and configuration
30235 file) are enough to reproduce the operating system ``from source''.
30238 This information is necessary to rebuild your operating system, but it
30239 is not always sufficient. In particular, @file{configuration.scm}
30240 itself is insufficient if it is not self-contained---if it refers to
30241 external Guile modules or to extra files. If you want
30242 @file{configuration.scm} to be self-contained, we recommend that modules
30243 or files it refers to be part of a channel.
30245 Besides, provenance meta-data is ``silent'' in the sense that it does
30246 not change the bits contained in your system, @emph{except for the
30247 meta-data bits themselves}. Two different OS configurations or sets of
30248 channels can lead to the same system, bit-for-bit; when
30249 @code{provenance-service-type} is used, these two systems will have
30250 different meta-data and thus different store file names, which makes
30251 comparison less trivial.
30254 This service is automatically added to your operating system
30255 configuration when you use @command{guix system reconfigure},
30256 @command{guix system init}, or @command{guix deploy}.
30259 @node Shepherd Services
30260 @subsection Shepherd Services
30262 @cindex shepherd services
30264 @cindex init system
30265 The @code{(gnu services shepherd)} module provides a way to define
30266 services managed by the GNU@tie{}Shepherd, which is the
30267 initialization system---the first process that is started when the
30268 system boots, also known as PID@tie{}1
30269 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
30271 Services in the Shepherd can depend on each other. For instance, the
30272 SSH daemon may need to be started after the syslog daemon has been
30273 started, which in turn can only happen once all the file systems have
30274 been mounted. The simple operating system defined earlier (@pxref{Using
30275 the Configuration System}) results in a service graph like this:
30277 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
30279 You can actually generate such a graph for any operating system
30280 definition using the @command{guix system shepherd-graph} command
30281 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
30283 The @code{%shepherd-root-service} is a service object representing
30284 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
30285 by passing it lists of @code{<shepherd-service>} objects.
30287 @deftp {Data Type} shepherd-service
30288 The data type representing a service managed by the Shepherd.
30291 @item @code{provision}
30292 This is a list of symbols denoting what the service provides.
30294 These are the names that may be passed to @command{herd start},
30295 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
30296 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
30297 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
30299 @item @code{requirement} (default: @code{'()})
30300 List of symbols denoting the Shepherd services this one depends on.
30302 @cindex one-shot services, for the Shepherd
30303 @item @code{one-shot?} (default: @code{#f})
30304 Whether this service is @dfn{one-shot}. One-shot services stop immediately
30305 after their @code{start} action has completed. @xref{Slots of services,,,
30306 shepherd, The GNU Shepherd Manual}, for more info.
30308 @item @code{respawn?} (default: @code{#t})
30309 Whether to restart the service when it stops, for instance when the
30310 underlying process dies.
30313 @itemx @code{stop} (default: @code{#~(const #f)})
30314 The @code{start} and @code{stop} fields refer to the Shepherd's
30315 facilities to start and stop processes (@pxref{Service De- and
30316 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
30317 G-expressions that get expanded in the Shepherd configuration file
30318 (@pxref{G-Expressions}).
30320 @item @code{actions} (default: @code{'()})
30321 @cindex actions, of Shepherd services
30322 This is a list of @code{shepherd-action} objects (see below) defining
30323 @dfn{actions} supported by the service, in addition to the standard
30324 @code{start} and @code{stop} actions. Actions listed here become available as
30325 @command{herd} sub-commands:
30328 herd @var{action} @var{service} [@var{arguments}@dots{}]
30331 @item @code{auto-start?} (default: @code{#t})
30332 Whether this service should be started automatically by the Shepherd. If it
30333 is @code{#f} the service has to be started manually with @code{herd start}.
30335 @item @code{documentation}
30336 A documentation string, as shown when running:
30339 herd doc @var{service-name}
30342 where @var{service-name} is one of the symbols in @code{provision}
30343 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
30345 @item @code{modules} (default: @code{%default-modules})
30346 This is the list of modules that must be in scope when @code{start} and
30347 @code{stop} are evaluated.
30352 @deftp {Data Type} shepherd-action
30353 This is the data type that defines additional actions implemented by a
30354 Shepherd service (see above).
30358 Symbol naming the action.
30360 @item documentation
30361 This is a documentation string for the action. It can be viewed by running:
30364 herd doc @var{service} action @var{action}
30368 This should be a gexp that evaluates to a procedure of at least one argument,
30369 which is the ``running value'' of the service (@pxref{Slots of services,,,
30370 shepherd, The GNU Shepherd Manual}).
30373 The following example defines an action called @code{say-hello} that kindly
30379 (documentation "Say hi!")
30380 (procedure #~(lambda (running . args)
30381 (format #t "Hello, friend! arguments: ~s\n"
30386 Assuming this action is added to the @code{example} service, then you can do:
30389 # herd say-hello example
30390 Hello, friend! arguments: ()
30391 # herd say-hello example a b c
30392 Hello, friend! arguments: ("a" "b" "c")
30395 This, as you can see, is a fairly sophisticated way to say hello.
30396 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
30400 @defvr {Scheme Variable} shepherd-root-service-type
30401 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
30403 This is the service type that extensions target when they want to create
30404 shepherd services (@pxref{Service Types and Services}, for an example).
30405 Each extension must pass a list of @code{<shepherd-service>}.
30408 @defvr {Scheme Variable} %shepherd-root-service
30409 This service represents PID@tie{}1.
30413 @node Documentation
30414 @chapter Documentation
30416 @cindex documentation, searching for
30417 @cindex searching for documentation
30418 @cindex Info, documentation format
30420 @cindex manual pages
30421 In most cases packages installed with Guix come with documentation.
30422 There are two main documentation formats: ``Info'', a browseable
30423 hypertext format used for GNU software, and ``manual pages'' (or ``man
30424 pages''), the linear documentation format traditionally found on Unix.
30425 Info manuals are accessed with the @command{info} command or with Emacs,
30426 and man pages are accessed using @command{man}.
30428 You can look for documentation of software installed on your system by
30429 keyword. For example, the following command searches for information
30430 about ``TLS'' in Info manuals:
30434 "(emacs)Network Security" -- STARTTLS
30435 "(emacs)Network Security" -- TLS
30436 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
30437 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
30442 The command below searches for the same keyword in man pages:
30446 SSL (7) - OpenSSL SSL/TLS library
30447 certtool (1) - GnuTLS certificate tool
30451 These searches are purely local to your computer so you have the
30452 guarantee that documentation you find corresponds to what you have
30453 actually installed, you can access it off-line, and your privacy is
30456 Once you have these results, you can view the relevant documentation by
30460 $ info "(gnutls)Core TLS API"
30470 Info manuals contain sections and indices as well as hyperlinks like
30471 those found in Web pages. The @command{info} reader (@pxref{Top, Info
30472 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
30473 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
30474 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
30475 Introduction}, for an introduction to Info navigation.
30477 @node Installing Debugging Files
30478 @chapter Installing Debugging Files
30480 @cindex debugging files
30481 Program binaries, as produced by the GCC compilers for instance, are
30482 typically written in the ELF format, with a section containing
30483 @dfn{debugging information}. Debugging information is what allows the
30484 debugger, GDB, to map binary code to source code; it is required to
30485 debug a compiled program in good conditions.
30487 The problem with debugging information is that is takes up a fair amount
30488 of disk space. For example, debugging information for the GNU C Library
30489 weighs in at more than 60 MiB. Thus, as a user, keeping all the
30490 debugging info of all the installed programs is usually not an option.
30491 Yet, space savings should not come at the cost of an impediment to
30492 debugging---especially in the GNU system, which should make it easier
30493 for users to exert their computing freedom (@pxref{GNU Distribution}).
30495 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
30496 mechanism that allows users to get the best of both worlds: debugging
30497 information can be stripped from the binaries and stored in separate
30498 files. GDB is then able to load debugging information from those files,
30499 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
30502 The GNU distribution takes advantage of this by storing debugging
30503 information in the @code{lib/debug} sub-directory of a separate package
30504 output unimaginatively called @code{debug} (@pxref{Packages with
30505 Multiple Outputs}). Users can choose to install the @code{debug} output
30506 of a package when they need it. For instance, the following command
30507 installs the debugging information for the GNU C Library and for GNU
30511 guix install glibc:debug guile:debug
30514 GDB must then be told to look for debug files in the user's profile, by
30515 setting the @code{debug-file-directory} variable (consider setting it
30516 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
30520 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
30523 From there on, GDB will pick up debugging information from the
30524 @file{.debug} files under @file{~/.guix-profile/lib/debug}.
30526 In addition, you will most likely want GDB to be able to show the source
30527 code being debugged. To do that, you will have to unpack the source
30528 code of the package of interest (obtained with @code{guix build
30529 --source}, @pxref{Invoking guix build}), and to point GDB to that source
30530 directory using the @code{directory} command (@pxref{Source Path,
30531 @code{directory},, gdb, Debugging with GDB}).
30533 @c XXX: keep me up-to-date
30534 The @code{debug} output mechanism in Guix is implemented by the
30535 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
30536 opt-in---debugging information is available only for the packages
30537 with definitions explicitly declaring a @code{debug} output. This may be
30538 changed to opt-out in the future if our build farm servers can handle
30539 the load. To check whether a package has a @code{debug} output, use
30540 @command{guix package --list-available} (@pxref{Invoking guix package}).
30543 @node Security Updates
30544 @chapter Security Updates
30546 @cindex security updates
30547 @cindex security vulnerabilities
30548 Occasionally, important security vulnerabilities are discovered in software
30549 packages and must be patched. Guix developers try hard to keep track of
30550 known vulnerabilities and to apply fixes as soon as possible in the
30551 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
30552 containing only security updates). The @command{guix lint} tool helps
30553 developers find out about vulnerable versions of software packages in the
30558 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
30559 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
30560 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
30564 @xref{Invoking guix lint}, for more information.
30566 Guix follows a functional
30567 package management discipline (@pxref{Introduction}), which implies
30568 that, when a package is changed, @emph{every package that depends on it}
30569 must be rebuilt. This can significantly slow down the deployment of
30570 fixes in core packages such as libc or Bash, since basically the whole
30571 distribution would need to be rebuilt. Using pre-built binaries helps
30572 (@pxref{Substitutes}), but deployment may still take more time than
30576 To address this, Guix implements @dfn{grafts}, a mechanism that allows
30577 for fast deployment of critical updates without the costs associated
30578 with a whole-distribution rebuild. The idea is to rebuild only the
30579 package that needs to be patched, and then to ``graft'' it onto packages
30580 explicitly installed by the user and that were previously referring to
30581 the original package. The cost of grafting is typically very low, and
30582 order of magnitudes lower than a full rebuild of the dependency chain.
30584 @cindex replacements of packages, for grafts
30585 For instance, suppose a security update needs to be applied to Bash.
30586 Guix developers will provide a package definition for the ``fixed''
30587 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
30588 Packages}). Then, the original package definition is augmented with a
30589 @code{replacement} field pointing to the package containing the bug fix:
30596 (replacement bash-fixed)))
30599 From there on, any package depending directly or indirectly on Bash---as
30600 reported by @command{guix gc --requisites} (@pxref{Invoking guix
30601 gc})---that is installed is automatically ``rewritten'' to refer to
30602 @code{bash-fixed} instead of @code{bash}. This grafting process takes
30603 time proportional to the size of the package, usually less than a
30604 minute for an ``average'' package on a recent machine. Grafting is
30605 recursive: when an indirect dependency requires grafting, then grafting
30606 ``propagates'' up to the package that the user is installing.
30608 Currently, the length of the name and version of the graft and that of
30609 the package it replaces (@code{bash-fixed} and @code{bash} in the example
30610 above) must be equal. This restriction mostly comes from the fact that
30611 grafting works by patching files, including binary files, directly.
30612 Other restrictions may apply: for instance, when adding a graft to a
30613 package providing a shared library, the original shared library and its
30614 replacement must have the same @code{SONAME} and be binary-compatible.
30616 The @option{--no-grafts} command-line option allows you to forcefully
30617 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
30621 guix build bash --no-grafts
30625 returns the store file name of the original Bash, whereas:
30632 returns the store file name of the ``fixed'', replacement Bash. This
30633 allows you to distinguish between the two variants of Bash.
30635 To verify which Bash your whole profile refers to, you can run
30636 (@pxref{Invoking guix gc}):
30639 guix gc -R `readlink -f ~/.guix-profile` | grep bash
30643 @dots{} and compare the store file names that you get with those above.
30644 Likewise for a complete Guix system generation:
30647 guix gc -R `guix system build my-config.scm` | grep bash
30650 Lastly, to check which Bash running processes are using, you can use the
30651 @command{lsof} command:
30654 lsof | grep /gnu/store/.*bash
30658 @node Bootstrapping
30659 @chapter Bootstrapping
30661 @c Adapted from the ELS 2013 paper.
30663 @cindex bootstrapping
30665 Bootstrapping in our context refers to how the distribution gets built
30666 ``from nothing''. Remember that the build environment of a derivation
30667 contains nothing but its declared inputs (@pxref{Introduction}). So
30668 there's an obvious chicken-and-egg problem: how does the first package
30669 get built? How does the first compiler get compiled? Note that this is
30670 a question of interest only to the curious hacker, not to the regular
30671 user, so you can shamelessly skip this section if you consider yourself
30672 a ``regular user''.
30674 @cindex bootstrap binaries
30675 The GNU system is primarily made of C code, with libc at its core. The
30676 GNU build system itself assumes the availability of a Bourne shell and
30677 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
30678 `grep'. Furthermore, build programs---programs that run
30679 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
30680 (@pxref{Derivations}). Consequently, to be able to build anything at
30681 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
30682 Binutils, libc, and the other packages mentioned above---the
30683 @dfn{bootstrap binaries}.
30685 These bootstrap binaries are ``taken for granted'', though we can also
30686 re-create them if needed (@pxref{Preparing to Use the Bootstrap
30690 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
30691 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
30694 @node Reduced Binary Seed Bootstrap
30695 @section The Reduced Binary Seed Bootstrap
30697 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
30698 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
30699 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
30700 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
30701 ``taken for granted.''
30703 Taking the bootstrap binaries for granted means that we consider them to
30704 be a correct and trustworthy ``seed'' for building the complete system.
30705 Therein lies a problem: the combined size of these bootstrap binaries is
30706 about 250MB (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing
30707 or even inspecting these is next to impossible.
30709 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a
30710 ``Reduced Binary Seed'' bootstrap @footnote{We would like to say: ``Full
30711 Source Bootstrap'' and while we are working towards that goal it would
30712 be hyperbole to use that term for what we do now.}.
30714 The Reduced Binary Seed bootstrap removes the most critical tools---from a
30715 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
30716 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
30717 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
30718 written in Scheme and the Mes C Library, built for TinyCC and for GCC).
30720 Using these new binary seeds the ``missing'' Binutils, GCC, and the GNU
30721 C Library are built from source. From here on the more traditional
30722 bootstrap process resumes. This approach has reduced the bootstrap
30723 binaries in size to about 145MB in Guix v1.1.
30725 The next step that Guix has taken is to replace the shell and all its
30726 utilities with implementations in Guile Scheme, the @emph{Scheme-only
30727 bootstrap}. Gash (@pxref{Gash,,, gash, The Gash manual}) is a
30728 POSIX-compatible shell that replaces Bash, and it comes with Gash Utils
30729 which has minimalist replacements for Awk, the GNU Core Utilities, Grep,
30730 Gzip, Sed, and Tar. The rest of the bootstrap binary seeds that were
30731 removed are now built from source.
30733 Building the GNU System from source is currently only possibly by adding
30734 some historical GNU packages as intermediate steps@footnote{Packages
30735 such as @code{gcc-2.95.3}, @code{binutils-2.14}, @code{glibc-2.2.5},
30736 @code{gzip-1.2.4}, @code{tar-1.22}, and some others. For details, see
30737 @file{gnu/packages/commencement.scm}.}. As Gash and Gash Utils mature,
30738 and GNU packages become more bootstrappable again (e.g., new releases of
30739 GNU Sed will also ship as gzipped tarballs again, as alternative to the
30740 hard to bootstrap @code{xz}-compression), this set of added packages can
30741 hopefully be reduced again.
30743 The graph below shows the resulting dependency graph for
30744 @code{gcc-core-mesboot0}, the bootstrap compiler used for the
30745 traditional bootstrap of the rest of the Guix System.
30747 @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
30748 @image{images/gcc-core-mesboot0-graph,6in,,Dependency graph of gcc-core-mesboot0}
30750 The only significant binary bootstrap seeds that remain@footnote{
30751 Ignoring the 68KB @code{mescc-tools}; that will be removed later,
30752 together with @code{mes}.} are a Scheme intepreter and a Scheme
30753 compiler: GNU Mes and GNU Guile@footnote{Not shown in this graph are the
30754 static binaries for @file{bash}, @code{tar}, and @code{xz} that are used
30755 to get Guile running.}.
30757 This further reduction has brought down the size of the binary seed to
30758 about 60MB for @code{i686-linux} and @code{x86_64-linux}.
30760 Work is ongoing to remove all binary blobs from our free software
30761 bootstrap stack, working towards a Full Source Bootstrap. Also ongoing
30762 is work to bring these bootstraps to the @code{arm-linux} and
30763 @code{aarch64-linux} architectures and to the Hurd.
30765 If you are interested, join us on @samp{#bootstrappable} on the Freenode
30766 IRC network or discuss on @email{bug-mes@@gnu.org} or
30767 @email{gash-devel@@nongnu.org}.
30769 @node Preparing to Use the Bootstrap Binaries
30770 @section Preparing to Use the Bootstrap Binaries
30772 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
30773 @c large image, it's hard to scroll. Oh well.
30774 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
30776 The figure above shows the very beginning of the dependency graph of the
30777 distribution, corresponding to the package definitions of the @code{(gnu
30778 packages bootstrap)} module. A similar figure can be generated with
30779 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
30782 guix graph -t derivation \
30783 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
30784 | dot -Tps > gcc.ps
30787 or, for the further Reduced Binary Seed bootstrap
30790 guix graph -t derivation \
30791 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
30792 | dot -Tps > mes.ps
30795 At this level of detail, things are
30796 slightly complex. First, Guile itself consists of an ELF executable,
30797 along with many source and compiled Scheme files that are dynamically
30798 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
30799 tarball shown in this graph. This tarball is part of Guix's ``source''
30800 distribution, and gets inserted into the store with @code{add-to-store}
30801 (@pxref{The Store}).
30803 But how do we write a derivation that unpacks this tarball and adds it
30804 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
30805 derivation---the first one that gets built---uses @code{bash} as its
30806 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
30807 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
30808 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
30809 the Guix source distribution, whose sole purpose is to allow the Guile
30810 tarball to be unpacked.
30812 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
30813 Guile that can be used to run subsequent build programs. Its first task
30814 is to download tarballs containing the other pre-built binaries---this
30815 is what the @file{.tar.xz.drv} derivations do. Guix modules such as
30816 @code{ftp-client.scm} are used for this purpose. The
30817 @code{module-import.drv} derivations import those modules in a directory
30818 in the store, using the original layout. The
30819 @code{module-import-compiled.drv} derivations compile those modules, and
30820 write them in an output directory with the right layout. This
30821 corresponds to the @code{#:modules} argument of
30822 @code{build-expression->derivation} (@pxref{Derivations}).
30824 Finally, the various tarballs are unpacked by the derivations
30825 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
30826 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
30827 point we have a working C tool chain.
30829 @unnumberedsec Building the Build Tools
30831 Bootstrapping is complete when we have a full tool chain that does not
30832 depend on the pre-built bootstrap tools discussed above. This
30833 no-dependency requirement is verified by checking whether the files of
30834 the final tool chain contain references to the @file{/gnu/store}
30835 directories of the bootstrap inputs. The process that leads to this
30836 ``final'' tool chain is described by the package definitions found in
30837 the @code{(gnu packages commencement)} module.
30839 The @command{guix graph} command allows us to ``zoom out'' compared to
30840 the graph above, by looking at the level of package objects instead of
30841 individual derivations---remember that a package may translate to
30842 several derivations, typically one derivation to download its source,
30843 one to build the Guile modules it needs, and one to actually build the
30844 package from source. The command:
30847 guix graph -t bag \
30848 -e '(@@@@ (gnu packages commencement)
30849 glibc-final-with-bootstrap-bash)' | xdot -
30853 displays the dependency graph leading to the ``final'' C
30854 library@footnote{You may notice the @code{glibc-intermediate} label,
30855 suggesting that it is not @emph{quite} final, but as a good
30856 approximation, we will consider it final.}, depicted below.
30858 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
30860 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
30861 The first tool that gets built with the bootstrap binaries is
30862 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
30863 for all the following packages. From there Findutils and Diffutils get
30866 Then come the first-stage Binutils and GCC, built as pseudo cross
30867 tools---i.e., with @option{--target} equal to @option{--host}. They are
30868 used to build libc. Thanks to this cross-build trick, this libc is
30869 guaranteed not to hold any reference to the initial tool chain.
30871 From there the final Binutils and GCC (not shown above) are built. GCC
30872 uses @command{ld} from the final Binutils, and links programs against
30873 the just-built libc. This tool chain is used to build the other
30874 packages used by Guix and by the GNU Build System: Guile, Bash,
30877 And voilà! At this point we have the complete set of build tools that
30878 the GNU Build System expects. These are in the @code{%final-inputs}
30879 variable of the @code{(gnu packages commencement)} module, and are
30880 implicitly used by any package that uses @code{gnu-build-system}
30881 (@pxref{Build Systems, @code{gnu-build-system}}).
30884 @unnumberedsec Building the Bootstrap Binaries
30886 @cindex bootstrap binaries
30887 Because the final tool chain does not depend on the bootstrap binaries,
30888 those rarely need to be updated. Nevertheless, it is useful to have an
30889 automated way to produce them, should an update occur, and this is what
30890 the @code{(gnu packages make-bootstrap)} module provides.
30892 The following command builds the tarballs containing the bootstrap binaries
30893 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
30894 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
30895 and Guile, and a tarball containing a mixture of Coreutils and other basic
30896 command-line tools):
30899 guix build bootstrap-tarballs
30902 The generated tarballs are those that should be referred to in the
30903 @code{(gnu packages bootstrap)} module mentioned at the beginning of
30906 Still here? Then perhaps by now you've started to wonder: when do we
30907 reach a fixed point? That is an interesting question! The answer is
30908 unknown, but if you would like to investigate further (and have
30909 significant computational and storage resources to do so), then let us
30912 @unnumberedsec Reducing the Set of Bootstrap Binaries
30914 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
30915 binary code! Why is that a problem? It's a problem because these big chunks
30916 of binary code are practically non-auditable, which makes it hard to establish
30917 what source code produced them. Every unauditable binary also leaves us
30918 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
30919 paper @emph{Reflections on Trusting Trust}.
30921 This is mitigated by the fact that our bootstrap binaries were generated
30922 from an earlier Guix revision. Nevertheless it lacks the level of
30923 transparency that we get in the rest of the package dependency graph,
30924 where Guix always gives us a source-to-binary mapping. Thus, our goal
30925 is to reduce the set of bootstrap binaries to the bare minimum.
30927 The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
30928 on-going projects to do that. One of these is about replacing the
30929 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
30930 of increasing complexity, which could be built from source starting from
30931 a simple and auditable assembler.
30933 Our first major achievement is the replacement of of GCC, the GNU C Library
30934 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
30935 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
30936 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
30937 bootstrapped yet and thus we inject them as binary seeds. We call this the
30938 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
30939 binaries! Also, it has eliminated the C compiler binary; i686-linux and
30940 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
30942 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
30943 also looking at any other bootstrap binaries. Your help is welcome!
30946 @chapter Porting to a New Platform
30948 As discussed above, the GNU distribution is self-contained, and
30949 self-containment is achieved by relying on pre-built ``bootstrap
30950 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
30951 operating system kernel, CPU architecture, and application binary
30952 interface (ABI). Thus, to port the distribution to a platform that is
30953 not yet supported, one must build those bootstrap binaries, and update
30954 the @code{(gnu packages bootstrap)} module to use them on that platform.
30956 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
30957 When everything goes well, and assuming the GNU tool chain supports the
30958 target platform, this can be as simple as running a command like this
30962 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
30965 For this to work, the @code{glibc-dynamic-linker} procedure in
30966 @code{(gnu packages bootstrap)} must be augmented to return the right
30967 file name for libc's dynamic linker on that platform; likewise,
30968 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
30969 taught about the new platform.
30971 Once these are built, the @code{(gnu packages bootstrap)} module needs
30972 to be updated to refer to these binaries on the target platform. That
30973 is, the hashes and URLs of the bootstrap tarballs for the new platform
30974 must be added alongside those of the currently supported platforms. The
30975 bootstrap Guile tarball is treated specially: it is expected to be
30976 available locally, and @file{gnu/local.mk} has rules to download it for
30977 the supported architectures; a rule for the new platform must be added
30980 In practice, there may be some complications. First, it may be that the
30981 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
30982 above) is not recognized by all the GNU tools. Typically, glibc
30983 recognizes some of these, whereas GCC uses an extra @option{--with-abi}
30984 configure flag (see @code{gcc.scm} for examples of how to handle this).
30985 Second, some of the required packages could fail to build for that
30986 platform. Lastly, the generated binaries could be broken for some
30989 @c *********************************************************************
30990 @include contributing.texi
30992 @c *********************************************************************
30993 @node Acknowledgments
30994 @chapter Acknowledgments
30996 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
30997 which was designed and
30998 implemented by Eelco Dolstra, with contributions from other people (see
30999 the @file{nix/AUTHORS} file in Guix). Nix pioneered functional package
31000 management, and promoted unprecedented features, such as transactional
31001 package upgrades and rollbacks, per-user profiles, and referentially
31002 transparent build processes. Without this work, Guix would not exist.
31004 The Nix-based software distributions, Nixpkgs and NixOS, have also been
31005 an inspiration for Guix.
31007 GNU@tie{}Guix itself is a collective work with contributions from a
31008 number of people. See the @file{AUTHORS} file in Guix for more
31009 information on these fine people. The @file{THANKS} file lists people
31010 who have helped by reporting bugs, taking care of the infrastructure,
31011 providing artwork and themes, making suggestions, and more---thank you!
31014 @c *********************************************************************
31015 @node GNU Free Documentation License
31016 @appendix GNU Free Documentation License
31017 @cindex license, GNU Free Documentation License
31018 @include fdl-1.3.texi
31020 @c *********************************************************************
31021 @node Concept Index
31022 @unnumbered Concept Index
31025 @node Programming Index
31026 @unnumbered Programming Index
31027 @syncodeindex tp fn
31028 @syncodeindex vr fn
31033 @c Local Variables:
31034 @c ispell-local-dictionary: "american";