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 Florian Pelz@*
63 Copyright @copyright{} 2018 Laura Lazzati@*
64 Copyright @copyright{} 2018 Alex Vong@*
65 Copyright @copyright{} 2019 Josh Holland@*
66 Copyright @copyright{} 2019, 2020 Diego Nicola Barbato@*
67 Copyright @copyright{} 2019 Ivan Petkov@*
68 Copyright @copyright{} 2019 Jakob L. Kreuze@*
69 Copyright @copyright{} 2019 Kyle Andrews@*
70 Copyright @copyright{} 2019 Alex Griffin@*
71 Copyright @copyright{} 2019 Guillaume Le Vaillant@*
72 Copyright @copyright{} 2020 Leo Prikler@*
73 Copyright @copyright{} 2019, 2020 Simon Tournier@*
74 Copyright @copyright{} 2020 Wiktor Żelazny@*
75 Copyright @copyright{} 2020 Damien Cassou@*
76 Copyright @copyright{} 2020 Jakub Kądziołka@*
77 Copyright @copyright{} 2020 Jack Hill@*
78 Copyright @copyright{} 2020 Naga Malleswari@*
79 Copyright @copyright{} 2020 Brice Waegeneire@*
80 Copyright @copyright{} 2020 R Veera Kumar@*
81 Copyright @copyright{} 2020 Pierre Langlois@*
82 Copyright @copyright{} 2020 pinoaffe@*
84 Permission is granted to copy, distribute and/or modify this document
85 under the terms of the GNU Free Documentation License, Version 1.3 or
86 any later version published by the Free Software Foundation; with no
87 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
88 copy of the license is included in the section entitled ``GNU Free
89 Documentation License''.
92 @dircategory System administration
94 * Guix: (guix). Manage installed software and system configuration.
95 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
96 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
97 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
98 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
99 * guix deploy: (guix)Invoking guix deploy. Manage operating system configurations for remote hosts.
102 @dircategory Software development
104 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
105 * guix build: (guix)Invoking guix build. Building packages.
106 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
110 @title GNU Guix Reference Manual
111 @subtitle Using the GNU Guix Functional Package Manager
112 @author The GNU Guix Developers
115 @vskip 0pt plus 1filll
116 Edition @value{EDITION} @*
124 @c *********************************************************************
128 This document describes GNU Guix version @value{VERSION}, a functional
129 package management tool written for the GNU system.
131 @c TRANSLATORS: You can replace the following paragraph with information on
132 @c how to join your own translation team and how to report issues with the
134 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
135 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
136 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
137 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
138 Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
139 would like to translate it in your native language, consider joining the
140 @uref{https://translationproject.org/domain/guix-manual.html, Translation
144 * Introduction:: What is Guix about?
145 * Installation:: Installing Guix.
146 * System Installation:: Installing the whole operating system.
147 * Getting Started:: Your first steps.
148 * Package Management:: Package installation, upgrade, etc.
149 * Development:: Guix-aided software development.
150 * Programming Interface:: Using Guix in Scheme.
151 * Utilities:: Package management commands.
152 * System Configuration:: Configuring the operating system.
153 * Documentation:: Browsing software user manuals.
154 * Installing Debugging Files:: Feeding the debugger.
155 * Security Updates:: Deploying security fixes quickly.
156 * Bootstrapping:: GNU/Linux built from scratch.
157 * Porting:: Targeting another platform or kernel.
158 * Contributing:: Your help needed!
160 * Acknowledgments:: Thanks!
161 * GNU Free Documentation License:: The license of this manual.
162 * Concept Index:: Concepts.
163 * Programming Index:: Data types, functions, and variables.
166 --- The Detailed Node Listing ---
170 * Managing Software the Guix Way:: What's special.
171 * GNU Distribution:: The packages and tools.
175 * Binary Installation:: Getting Guix running in no time!
176 * Requirements:: Software needed to build and run Guix.
177 * Running the Test Suite:: Testing Guix.
178 * Setting Up the Daemon:: Preparing the build daemon's environment.
179 * Invoking guix-daemon:: Running the build daemon.
180 * Application Setup:: Application-specific setup.
182 Setting Up the Daemon
184 * Build Environment Setup:: Preparing the isolated build environment.
185 * Daemon Offload Setup:: Offloading builds to remote machines.
186 * SELinux Support:: Using an SELinux policy for the daemon.
190 * Limitations:: What you can expect.
191 * Hardware Considerations:: Supported hardware.
192 * USB Stick and DVD Installation:: Preparing the installation medium.
193 * Preparing for Installation:: Networking, partitioning, etc.
194 * Guided Graphical Installation:: Easy graphical installation.
195 * Manual Installation:: Manual installation for wizards.
196 * After System Installation:: When installation succeeded.
197 * Installing Guix in a VM:: Guix System playground.
198 * Building the Installation Image:: How this comes to be.
204 * Keyboard Layout and Networking and Partitioning:: Initial setup.
205 * Proceeding with the Installation:: Installing.
209 * Features:: How Guix will make your life brighter.
210 * Invoking guix package:: Package installation, removal, etc.
211 * Substitutes:: Downloading pre-built binaries.
212 * Packages with Multiple Outputs:: Single source package, multiple outputs.
213 * Invoking guix gc:: Running the garbage collector.
214 * Invoking guix pull:: Fetching the latest Guix and distribution.
215 * Channels:: Customizing the package collection.
216 * Invoking guix time-machine:: Running an older revision of Guix.
217 * Inferiors:: Interacting with another revision of Guix.
218 * Invoking guix describe:: Display information about your Guix revision.
219 * Invoking guix archive:: Exporting and importing store files.
223 * Official Substitute Server:: One particular source of substitutes.
224 * Substitute Server Authorization:: How to enable or disable substitutes.
225 * Substitute Authentication:: How Guix verifies substitutes.
226 * Proxy Settings:: How to get substitutes via proxy.
227 * Substitution Failure:: What happens when substitution fails.
228 * On Trusting Binaries:: How can you trust that binary blob?
232 * Invoking guix environment:: Setting up development environments.
233 * Invoking guix pack:: Creating software bundles.
234 * The GCC toolchain:: Working with languages supported by GCC.
236 Programming Interface
238 * Package Modules:: Packages from the programmer's viewpoint.
239 * Defining Packages:: Defining new packages.
240 * Build Systems:: Specifying how packages are built.
241 * The Store:: Manipulating the package store.
242 * Derivations:: Low-level interface to package derivations.
243 * The Store Monad:: Purely functional interface to the store.
244 * G-Expressions:: Manipulating build expressions.
245 * Invoking guix repl:: Programming Guix in Guile
249 * package Reference:: The package data type.
250 * origin Reference:: The origin data type.
254 * Invoking guix build:: Building packages from the command line.
255 * Invoking guix edit:: Editing package definitions.
256 * Invoking guix download:: Downloading a file and printing its hash.
257 * Invoking guix hash:: Computing the cryptographic hash of a file.
258 * Invoking guix import:: Importing package definitions.
259 * Invoking guix refresh:: Updating package definitions.
260 * Invoking guix lint:: Finding errors in package definitions.
261 * Invoking guix size:: Profiling disk usage.
262 * Invoking guix graph:: Visualizing the graph of packages.
263 * Invoking guix publish:: Sharing substitutes.
264 * Invoking guix challenge:: Challenging substitute servers.
265 * Invoking guix copy:: Copying to and from a remote store.
266 * Invoking guix container:: Process isolation.
267 * Invoking guix weather:: Assessing substitute availability.
268 * Invoking guix processes:: Listing client processes.
270 Invoking @command{guix build}
272 * Common Build Options:: Build options for most commands.
273 * Package Transformation Options:: Creating variants of packages.
274 * Additional Build Options:: Options specific to 'guix build'.
275 * Debugging Build Failures:: Real life packaging experience.
279 * Using the Configuration System:: Customizing your GNU system.
280 * operating-system Reference:: Detail of operating-system declarations.
281 * File Systems:: Configuring file system mounts.
282 * Mapped Devices:: Block device extra processing.
283 * User Accounts:: Specifying user accounts.
284 * Keyboard Layout:: How the system interprets key strokes.
285 * Locales:: Language and cultural convention settings.
286 * Services:: Specifying system services.
287 * Setuid Programs:: Programs running with root privileges.
288 * X.509 Certificates:: Authenticating HTTPS servers.
289 * Name Service Switch:: Configuring libc's name service switch.
290 * Initial RAM Disk:: Linux-Libre bootstrapping.
291 * Bootloader Configuration:: Configuring the boot loader.
292 * Invoking guix system:: Instantiating a system configuration.
293 * Invoking guix deploy:: Deploying a system configuration to a remote host.
294 * Running Guix in a VM:: How to run Guix System in a virtual machine.
295 * Defining Services:: Adding new service definitions.
299 * Base Services:: Essential system services.
300 * Scheduled Job Execution:: The mcron service.
301 * Log Rotation:: The rottlog service.
302 * Networking Services:: Network setup, SSH daemon, etc.
303 * X Window:: Graphical display.
304 * Printing Services:: Local and remote printer support.
305 * Desktop Services:: D-Bus and desktop services.
306 * Sound Services:: ALSA and Pulseaudio services.
307 * Database Services:: SQL databases, key-value stores, etc.
308 * Mail Services:: IMAP, POP3, SMTP, and all that.
309 * Messaging Services:: Messaging services.
310 * Telephony Services:: Telephony services.
311 * Monitoring Services:: Monitoring services.
312 * Kerberos Services:: Kerberos services.
313 * Web Services:: Web servers.
314 * Certificate Services:: TLS certificates via Let's Encrypt.
315 * DNS Services:: DNS daemons.
316 * VPN Services:: VPN daemons.
317 * Network File System:: NFS related services.
318 * Continuous Integration:: The Cuirass service.
319 * Power Management Services:: Extending battery life.
320 * Audio Services:: The MPD.
321 * Virtualization Services:: Virtualization services.
322 * Version Control Services:: Providing remote access to Git repositories.
323 * Game Services:: Game servers.
324 * PAM Mount Service:: Service to mount volumes when logging in.
325 * Guix Services:: Services relating specifically to Guix.
326 * Linux Services:: Services tied to the Linux kernel.
327 * Hurd Services:: Services specific to a Hurd System.
328 * Miscellaneous Services:: Other services.
332 * Service Composition:: The model for composing services.
333 * Service Types and Services:: Types and services.
334 * Service Reference:: API reference.
335 * Shepherd Services:: A particular type of service.
340 @c *********************************************************************
342 @chapter Introduction
345 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
346 using the international phonetic alphabet (IPA).} is a package
347 management tool for and distribution of the GNU system.
348 Guix makes it easy for unprivileged
349 users to install, upgrade, or remove software packages, to roll back to a
350 previous package set, to build packages from source, and generally
351 assists with the creation and maintenance of software environments.
354 @cindex GuixSD, now Guix System
355 @cindex Guix System Distribution, now Guix System
356 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
357 complements the available tools without interference (@pxref{Installation}),
358 or you can use it as a standalone operating system distribution,
359 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
360 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
361 group everything under the ``Guix'' banner since, after all, Guix System is
362 readily available through the @command{guix system} command, even if you're
363 using a different distro underneath!}. @xref{GNU Distribution}.
366 * Managing Software the Guix Way:: What's special.
367 * GNU Distribution:: The packages and tools.
370 @node Managing Software the Guix Way
371 @section Managing Software the Guix Way
373 @cindex user interfaces
374 Guix provides a command-line package management interface
375 (@pxref{Package Management}), tools to help with software development
376 (@pxref{Development}), command-line utilities for more advanced usage,
377 (@pxref{Utilities}), as well as Scheme programming interfaces
378 (@pxref{Programming Interface}).
380 Its @dfn{build daemon} is responsible for building packages on behalf of
381 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
382 binaries from authorized sources (@pxref{Substitutes}).
384 @cindex extensibility of the distribution
385 @cindex customization, of packages
386 Guix includes package definitions for many GNU and non-GNU packages, all
387 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
388 user's computing freedom}. It is @emph{extensible}: users can write
389 their own package definitions (@pxref{Defining Packages}) and make them
390 available as independent package modules (@pxref{Package Modules}). It
391 is also @emph{customizable}: users can @emph{derive} specialized package
392 definitions from existing ones, including from the command line
393 (@pxref{Package Transformation Options}).
395 @cindex functional package management
397 Under the hood, Guix implements the @dfn{functional package management}
398 discipline pioneered by Nix (@pxref{Acknowledgments}).
399 In Guix, the package build and installation process is seen
400 as a @emph{function}, in the mathematical sense. That function takes inputs,
401 such as build scripts, a compiler, and libraries, and
402 returns an installed package. As a pure function, its result depends
403 solely on its inputs---for instance, it cannot refer to software or
404 scripts that were not explicitly passed as inputs. A build function
405 always produces the same result when passed a given set of inputs. It
406 cannot alter the environment of the running system in
407 any way; for instance, it cannot create, modify, or delete files outside
408 of its build and installation directories. This is achieved by running
409 build processes in isolated environments (or @dfn{containers}), where only their
410 explicit inputs are visible.
413 The result of package build functions is @dfn{cached} in the file
414 system, in a special directory called @dfn{the store} (@pxref{The
415 Store}). Each package is installed in a directory of its own in the
416 store---by default under @file{/gnu/store}. The directory name contains
417 a hash of all the inputs used to build that package; thus, changing an
418 input yields a different directory name.
420 This approach is the foundation for the salient features of Guix: support
421 for transactional package upgrade and rollback, per-user installation, and
422 garbage collection of packages (@pxref{Features}).
425 @node GNU Distribution
426 @section GNU Distribution
429 Guix comes with a distribution of the GNU system consisting entirely of
430 free software@footnote{The term ``free'' here refers to the
431 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
432 users of that software}.}. The
433 distribution can be installed on its own (@pxref{System Installation}),
434 but it is also possible to install Guix as a package manager on top of
435 an installed GNU/Linux system (@pxref{Installation}). When we need to
436 distinguish between the two, we refer to the standalone distribution as
439 The distribution provides core GNU packages such as GNU libc, GCC, and
440 Binutils, as well as many GNU and non-GNU applications. The complete
441 list of available packages can be browsed
442 @url{https://www.gnu.org/software/guix/packages,on-line} or by
443 running @command{guix package} (@pxref{Invoking guix package}):
446 guix package --list-available
449 Our goal is to provide a practical 100% free software distribution of
450 Linux-based and other variants of GNU, with a focus on the promotion and
451 tight integration of GNU components, and an emphasis on programs and
452 tools that help users exert that freedom.
454 Packages are currently available on the following platforms:
459 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
462 Intel 32-bit architecture (IA32), Linux-Libre kernel;
465 ARMv7-A architecture with hard float, Thumb-2 and NEON,
466 using the EABI hard-float application binary interface (ABI),
467 and Linux-Libre kernel.
470 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
472 @item mips64el-linux (deprecated)
473 little-endian 64-bit MIPS processors, specifically the Loongson series,
474 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
475 supported; in particular, there is no ongoing work to ensure that this
476 architecture still works. Should someone decide they wish to revive this
477 architecture then the code is still available.
481 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
482 configuration and Guix takes care of instantiating the configuration in a
483 transactional, reproducible, and stateless fashion (@pxref{System
484 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
485 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
486 Manual}), the well-known GNU utilities and tool chain, as well as the
487 graphical environment or system services of your choice.
489 Guix System is available on all the above platforms except
490 @code{mips64el-linux}.
493 For information on porting to other architectures or kernels,
496 Building this distribution is a cooperative effort, and you are invited
497 to join! @xref{Contributing}, for information about how you can help.
500 @c *********************************************************************
502 @chapter Installation
504 @cindex installing Guix
507 We recommend the use of this
508 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
509 shell installer script} to install Guix on top of a running GNU/Linux system,
510 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
511 with the installation of the package manager, which can be done on top of a
512 running GNU/Linux system. If, instead, you want to install the complete GNU
513 operating system, @pxref{System Installation}.} The script automates the
514 download, installation, and initial configuration of Guix. It should be run
518 @cindex foreign distro
519 @cindex directories related to foreign distro
520 When installed on a foreign distro, GNU@tie{}Guix complements the available
521 tools without interference. Its data lives exclusively in two directories,
522 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
523 such as @file{/etc}, are left untouched.
525 Once installed, Guix can be updated by running @command{guix pull}
526 (@pxref{Invoking guix pull}).
528 If you prefer to perform the installation steps manually or want to tweak
529 them, you may find the following subsections useful. They describe the
530 software requirements of Guix, as well as how to install it manually and get
534 * Binary Installation:: Getting Guix running in no time!
535 * Requirements:: Software needed to build and run Guix.
536 * Running the Test Suite:: Testing Guix.
537 * Setting Up the Daemon:: Preparing the build daemon's environment.
538 * Invoking guix-daemon:: Running the build daemon.
539 * Application Setup:: Application-specific setup.
540 * Upgrading Guix:: Upgrading Guix and its build daemon.
543 @node Binary Installation
544 @section Binary Installation
546 @cindex installing Guix from binaries
547 @cindex installer script
548 This section describes how to install Guix on an arbitrary system from a
549 self-contained tarball providing binaries for Guix and for all its
550 dependencies. This is often quicker than installing from source, which
551 is described in the next sections. The only requirement is to have
554 @c Note duplicated from the ``Installation'' node.
556 We recommend the use of this
557 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
558 shell installer script}. The script automates the download, installation, and
559 initial configuration steps described below. It should be run as the root
560 user. As root, you can thus run this:
564 wget https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh
565 chmod +x guix-install.sh
569 When you're done, @pxref{Application Setup} for extra configuration you
570 might need, and @ref{Getting Started} for your first steps!
573 Installing goes along these lines:
577 @cindex downloading Guix binary
578 Download the binary tarball from
579 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz},
580 where @code{x86_64-linux} can be replaced with @code{i686-linux} for an
581 @code{i686} (32-bits) machine already running the kernel Linux, and so on
582 (@pxref{GNU Distribution}).
584 @c The following is somewhat duplicated in ``System Installation''.
585 Make sure to download the associated @file{.sig} file and to verify the
586 authenticity of the tarball against it, along these lines:
589 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
590 $ gpg --verify guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
593 If that command fails because you do not have the required public key,
594 then run this command to import it:
597 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
598 -qO - | gpg --import -
602 and rerun the @code{gpg --verify} command.
604 Take note that a warning like ``This key is not certified with a trusted
605 signature!'' is normal.
607 @c end authentication part
610 Now, you need to become the @code{root} user. Depending on your distribution,
611 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
615 # tar --warning=no-timestamp -xf \
616 /path/to/guix-binary-@value{VERSION}.x86_64-linux.tar.xz
617 # mv var/guix /var/ && mv gnu /
620 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
621 The latter contains a ready-to-use profile for @code{root} (see next
624 Do @emph{not} unpack the tarball on a working Guix system since that
625 would overwrite its own essential files.
627 The @option{--warning=no-timestamp} option makes sure GNU@tie{}tar does
628 not emit warnings about ``implausibly old time stamps'' (such
629 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
631 They stem from the fact that all the
632 files in the archive have their modification time set to zero (which
633 means January 1st, 1970). This is done on purpose to make sure the
634 archive content is independent of its creation time, thus making it
638 Make the profile available under @file{~root/.config/guix/current}, which is
639 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
642 # mkdir -p ~root/.config/guix
643 # ln -sf /var/guix/profiles/per-user/root/current-guix \
644 ~root/.config/guix/current
647 Source @file{etc/profile} to augment @env{PATH} and other relevant
648 environment variables:
651 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
652 source $GUIX_PROFILE/etc/profile
656 Create the group and user accounts for build users as explained below
657 (@pxref{Build Environment Setup}).
660 Run the daemon, and set it to automatically start on boot.
662 If your host distro uses the systemd init system, this can be achieved
665 @c Versions of systemd that supported symlinked service files are not
666 @c yet widely deployed, so we should suggest that users copy the service
669 @c See this thread for more information:
670 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
673 # cp ~root/.config/guix/current/lib/systemd/system/gnu-store.mount \
674 ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
676 # systemctl enable --now gnu-store.mount guix-daemon
679 If your host distro uses the Upstart init system:
682 # initctl reload-configuration
683 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
688 Otherwise, you can still start the daemon manually with:
691 # ~root/.config/guix/current/bin/guix-daemon \
692 --build-users-group=guixbuild
696 Make the @command{guix} command available to other users on the machine,
700 # mkdir -p /usr/local/bin
702 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
705 It is also a good idea to make the Info version of this manual available
709 # mkdir -p /usr/local/share/info
710 # cd /usr/local/share/info
711 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
715 That way, assuming @file{/usr/local/share/info} is in the search path,
716 running @command{info guix} will open this manual (@pxref{Other Info
717 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
721 @cindex substitutes, authorization thereof
722 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
723 (@pxref{Substitutes}), authorize them:
726 # guix archive --authorize < \
727 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
731 Each user may need to perform a few additional steps to make their Guix
732 environment ready for use, @pxref{Application Setup}.
735 Voilà, the installation is complete!
737 You can confirm that Guix is working by installing a sample package into
744 The binary installation tarball can be (re)produced and verified simply
745 by running the following command in the Guix source tree:
748 make guix-binary.@var{system}.tar.xz
752 ...@: which, in turn, runs:
755 guix pack -s @var{system} --localstatedir \
756 --profile-name=current-guix guix
759 @xref{Invoking guix pack}, for more info on this handy tool.
762 @section Requirements
764 This section lists requirements when building Guix from source. The
765 build procedure for Guix is the same as for other GNU software, and is
766 not covered here. Please see the files @file{README} and @file{INSTALL}
767 in the Guix source tree for additional details.
769 @cindex official website
770 GNU Guix is available for download from its website at
771 @url{https://www.gnu.org/software/guix/}.
773 GNU Guix depends on the following packages:
776 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 3.0.x or
778 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
781 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
782 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
783 Guile,, gnutls-guile, GnuTLS-Guile});
785 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
787 @item @uref{https://notabug.org/guile-zlib/guile-zlib, Guile-zlib};
788 @item @uref{https://notabug.org/guile-lzlib/guile-lzlib, Guile-lzlib};
790 @c FIXME: Specify a version number once a release has been made.
791 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
793 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON}
795 @item @url{https://www.gnu.org/software/make/, GNU Make}.
798 The following dependencies are optional:
802 @c Note: We need at least 0.13.0 for #:nodelay.
803 Support for build offloading (@pxref{Daemon Offload Setup}) and
804 @command{guix copy} (@pxref{Invoking guix copy}) depends on
805 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
806 version 0.13.0 or later.
809 When @url{https://www.nongnu.org/lzip/lzlib.html, lzlib} is available, lzlib
810 substitutes can be used and @command{guix publish} can compress substitutes
814 When @url{http://www.bzip.org, libbz2} is available,
815 @command{guix-daemon} can use it to compress build logs.
818 Unless @option{--disable-daemon} was passed to @command{configure}, the
819 following packages are also needed:
822 @item @url{https://gnupg.org/, GNU libgcrypt};
823 @item @url{https://sqlite.org, SQLite 3};
824 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
828 @cindex state directory
829 When configuring Guix on a system that already has a Guix installation,
830 be sure to specify the same state directory as the existing installation
831 using the @option{--localstatedir} option of the @command{configure}
832 script (@pxref{Directory Variables, @code{localstatedir},, standards,
833 GNU Coding Standards}). Usually, this @var{localstatedir} option is
834 set to the value @file{/var}. The @command{configure} script protects
835 against unintended misconfiguration of @var{localstatedir} so you do not
836 inadvertently corrupt your store (@pxref{The Store}).
838 @node Running the Test Suite
839 @section Running the Test Suite
842 After a successful @command{configure} and @code{make} run, it is a good
843 idea to run the test suite. It can help catch issues with the setup or
844 environment, or bugs in Guix itself---and really, reporting test
845 failures is a good way to help improve the software. To run the test
852 Test cases can run in parallel: you can use the @code{-j} option of
853 GNU@tie{}make to speed things up. The first run may take a few minutes
854 on a recent machine; subsequent runs will be faster because the store
855 that is created for test purposes will already have various things in
858 It is also possible to run a subset of the tests by defining the
859 @code{TESTS} makefile variable as in this example:
862 make check TESTS="tests/store.scm tests/cpio.scm"
865 By default, tests results are displayed at a file level. In order to
866 see the details of every individual test cases, it is possible to define
867 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
870 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
873 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
874 @file{test-suite.log} file. Please specify the Guix version being used
875 as well as version numbers of the dependencies (@pxref{Requirements}) in
878 Guix also comes with a whole-system test suite that tests complete
879 Guix System instances. It can only run on systems where
880 Guix is already installed, using:
887 or, again, by defining @code{TESTS} to select a subset of tests to run:
890 make check-system TESTS="basic mcron"
893 These system tests are defined in the @code{(gnu tests @dots{})}
894 modules. They work by running the operating systems under test with
895 lightweight instrumentation in a virtual machine (VM). They can be
896 computationally intensive or rather cheap, depending on whether
897 substitutes are available for their dependencies (@pxref{Substitutes}).
898 Some of them require a lot of storage space to hold VM images.
900 Again in case of test failures, please send @email{bug-guix@@gnu.org}
903 @node Setting Up the Daemon
904 @section Setting Up the Daemon
907 Operations such as building a package or running the garbage collector
908 are all performed by a specialized process, the @dfn{build daemon}, on
909 behalf of clients. Only the daemon may access the store and its
910 associated database. Thus, any operation that manipulates the store
911 goes through the daemon. For instance, command-line tools such as
912 @command{guix package} and @command{guix build} communicate with the
913 daemon (@i{via} remote procedure calls) to instruct it what to do.
915 The following sections explain how to prepare the build daemon's
916 environment. See also @ref{Substitutes}, for information on how to allow
917 the daemon to download pre-built binaries.
920 * Build Environment Setup:: Preparing the isolated build environment.
921 * Daemon Offload Setup:: Offloading builds to remote machines.
922 * SELinux Support:: Using an SELinux policy for the daemon.
925 @node Build Environment Setup
926 @subsection Build Environment Setup
928 @cindex build environment
929 In a standard multi-user setup, Guix and its daemon---the
930 @command{guix-daemon} program---are installed by the system
931 administrator; @file{/gnu/store} is owned by @code{root} and
932 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
933 Guix tools to build packages or otherwise access the store, and the
934 daemon will do it on their behalf, ensuring that the store is kept in a
935 consistent state, and allowing built packages to be shared among users.
938 When @command{guix-daemon} runs as @code{root}, you may not want package
939 build processes themselves to run as @code{root} too, for obvious
940 security reasons. To avoid that, a special pool of @dfn{build users}
941 should be created for use by build processes started by the daemon.
942 These build users need not have a shell and a home directory: they will
943 just be used when the daemon drops @code{root} privileges in build
944 processes. Having several such users allows the daemon to launch
945 distinct build processes under separate UIDs, which guarantees that they
946 do not interfere with each other---an essential feature since builds are
947 regarded as pure functions (@pxref{Introduction}).
949 On a GNU/Linux system, a build user pool may be created like this (using
950 Bash syntax and the @code{shadow} commands):
952 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
953 @c for why `-G' is needed.
955 # groupadd --system guixbuild
956 # for i in `seq -w 1 10`;
958 useradd -g guixbuild -G guixbuild \
959 -d /var/empty -s `which nologin` \
960 -c "Guix build user $i" --system \
966 The number of build users determines how many build jobs may run in
967 parallel, as specified by the @option{--max-jobs} option
968 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
969 @command{guix system vm} and related commands, you may need to add the
970 build users to the @code{kvm} group so they can access @file{/dev/kvm},
971 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
972 (@pxref{Invoking guix system}).
974 The @code{guix-daemon} program may then be run as @code{root} with the
975 following command@footnote{If your machine uses the systemd init system,
976 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
977 file in @file{/etc/systemd/system} will ensure that
978 @command{guix-daemon} is automatically started. Similarly, if your
979 machine uses the Upstart init system, drop the
980 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
981 file in @file{/etc/init}.}:
984 # guix-daemon --build-users-group=guixbuild
989 This way, the daemon starts build processes in a chroot, under one of
990 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
991 environment contains nothing but:
993 @c Keep this list in sync with libstore/build.cc! -----------------------
996 a minimal @code{/dev} directory, created mostly independently from the
997 host @code{/dev}@footnote{``Mostly'', because while the set of files
998 that appear in the chroot's @code{/dev} is fixed, most of these files
999 can only be created if the host has them.};
1002 the @code{/proc} directory; it only shows the processes of the container
1003 since a separate PID name space is used;
1006 @file{/etc/passwd} with an entry for the current user and an entry for
1010 @file{/etc/group} with an entry for the user's group;
1013 @file{/etc/hosts} with an entry that maps @code{localhost} to
1017 a writable @file{/tmp} directory.
1020 You can influence the directory where the daemon stores build trees
1021 @i{via} the @env{TMPDIR} environment variable. However, the build tree
1022 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
1023 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
1024 This way, the value of @env{TMPDIR} does not leak inside build
1025 environments, which avoids discrepancies in cases where build processes
1026 capture the name of their build tree.
1030 The daemon also honors the @env{http_proxy} and @env{https_proxy}
1031 environment variables for HTTP and HTTPS downloads it performs, be it
1032 for fixed-output derivations (@pxref{Derivations}) or for substitutes
1033 (@pxref{Substitutes}).
1035 If you are installing Guix as an unprivileged user, it is still possible
1036 to run @command{guix-daemon} provided you pass @option{--disable-chroot}.
1037 However, build processes will not be isolated from one another, and not
1038 from the rest of the system. Thus, build processes may interfere with
1039 each other, and may access programs, libraries, and other files
1040 available on the system---making it much harder to view them as
1041 @emph{pure} functions.
1044 @node Daemon Offload Setup
1045 @subsection Using the Offload Facility
1049 When desired, the build daemon can @dfn{offload} derivation builds to
1050 other machines running Guix, using the @code{offload} @dfn{build
1051 hook}@footnote{This feature is available only when
1052 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1053 present.}. When that feature is enabled, a list of user-specified build
1054 machines is read from @file{/etc/guix/machines.scm}; every time a build
1055 is requested, for instance via @code{guix build}, the daemon attempts to
1056 offload it to one of the machines that satisfy the constraints of the
1057 derivation, in particular its system types---e.g., @code{x86_64-linux}.
1058 A single machine can have multiple system types, either because its
1059 architecture natively supports it, via emulation (@pxref{Transparent
1060 Emulation with QEMU}), or both. Missing prerequisites for the build are
1061 copied over SSH to the target machine, which then proceeds with the
1062 build; upon success the output(s) of the build are copied back to the
1065 The @file{/etc/guix/machines.scm} file typically looks like this:
1068 (list (build-machine
1069 (name "eightysix.example.org")
1070 (systems (list "x86_64-linux" "i686-linux"))
1071 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1073 (speed 2.)) ;incredibly fast!
1076 (name "armeight.example.org")
1077 (systems (list "aarch64-linux"))
1078 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1081 (string-append (getenv "HOME")
1082 "/.ssh/identity-for-guix"))))
1086 In the example above we specify a list of two build machines, one for
1087 the @code{x86_64} and @code{i686} architectures and one for the
1088 @code{aarch64} architecture.
1090 In fact, this file is---not surprisingly!---a Scheme file that is
1091 evaluated when the @code{offload} hook is started. Its return value
1092 must be a list of @code{build-machine} objects. While this example
1093 shows a fixed list of build machines, one could imagine, say, using
1094 DNS-SD to return a list of potential build machines discovered in the
1095 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1096 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1099 @deftp {Data Type} build-machine
1100 This data type represents build machines to which the daemon may offload
1101 builds. The important fields are:
1106 The host name of the remote machine.
1109 The system types the remote machine supports---e.g., @code{(list
1110 "x86_64-linux" "i686-linux")}.
1113 The user account to use when connecting to the remote machine over SSH.
1114 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1115 allow non-interactive logins.
1118 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1119 This is used to authenticate the machine when we connect to it. It is a
1120 long string that looks like this:
1123 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1126 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1127 key can be found in a file such as
1128 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1130 If the machine is running the SSH daemon of GNU@tie{}lsh,
1131 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1132 similar file. It can be converted to the OpenSSH format using
1133 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1136 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1137 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1142 A number of optional fields may be specified:
1146 @item @code{port} (default: @code{22})
1147 Port number of SSH server on the machine.
1149 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1150 The SSH private key file to use when connecting to the machine, in
1151 OpenSSH format. This key must not be protected with a passphrase.
1153 Note that the default value is the private key @emph{of the root
1154 account}. Make sure it exists if you use the default.
1156 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1157 @itemx @code{compression-level} (default: @code{3})
1158 The SSH-level compression methods and compression level requested.
1160 Note that offloading relies on SSH compression to reduce bandwidth usage
1161 when transferring files to and from build machines.
1163 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1164 File name of the Unix-domain socket @command{guix-daemon} is listening
1167 @item @code{parallel-builds} (default: @code{1})
1168 The number of builds that may run in parallel on the machine.
1170 @item @code{speed} (default: @code{1.0})
1171 A ``relative speed factor''. The offload scheduler will tend to prefer
1172 machines with a higher speed factor.
1174 @item @code{features} (default: @code{'()})
1175 A list of strings denoting specific features supported by the machine.
1176 An example is @code{"kvm"} for machines that have the KVM Linux modules
1177 and corresponding hardware support. Derivations can request features by
1178 name, and they will be scheduled on matching build machines.
1183 The @command{guix} command must be in the search path on the build
1184 machines. You can check whether this is the case by running:
1187 ssh build-machine guix repl --version
1190 There is one last thing to do once @file{machines.scm} is in place. As
1191 explained above, when offloading, files are transferred back and forth
1192 between the machine stores. For this to work, you first need to
1193 generate a key pair on each machine to allow the daemon to export signed
1194 archives of files from the store (@pxref{Invoking guix archive}):
1197 # guix archive --generate-key
1201 Each build machine must authorize the key of the master machine so that
1202 it accepts store items it receives from the master:
1205 # guix archive --authorize < master-public-key.txt
1209 Likewise, the master machine must authorize the key of each build machine.
1211 All the fuss with keys is here to express pairwise mutual trust
1212 relations between the master and the build machines. Concretely, when
1213 the master receives files from a build machine (and @i{vice versa}), its
1214 build daemon can make sure they are genuine, have not been tampered
1215 with, and that they are signed by an authorized key.
1217 @cindex offload test
1218 To test whether your setup is operational, run this command on the
1225 This will attempt to connect to each of the build machines specified in
1226 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1227 available on each machine, attempt to export to the machine and import
1228 from it, and report any error in the process.
1230 If you want to test a different machine file, just specify it on the
1234 # guix offload test machines-qualif.scm
1237 Last, you can test the subset of the machines whose name matches a
1238 regular expression like this:
1241 # guix offload test machines.scm '\.gnu\.org$'
1244 @cindex offload status
1245 To display the current load of all build hosts, run this command on the
1249 # guix offload status
1253 @node SELinux Support
1254 @subsection SELinux Support
1256 @cindex SELinux, daemon policy
1257 @cindex mandatory access control, SELinux
1258 @cindex security, guix-daemon
1259 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1260 can be installed on a system where SELinux is enabled, in order to label
1261 Guix files and to specify the expected behavior of the daemon. Since
1262 Guix System does not provide an SELinux base policy, the daemon policy cannot
1263 be used on Guix System.
1265 @subsubsection Installing the SELinux policy
1266 @cindex SELinux, policy installation
1267 To install the policy run this command as root:
1270 semodule -i etc/guix-daemon.cil
1273 Then relabel the file system with @code{restorecon} or by a different
1274 mechanism provided by your system.
1276 Once the policy is installed, the file system has been relabeled, and
1277 the daemon has been restarted, it should be running in the
1278 @code{guix_daemon_t} context. You can confirm this with the following
1282 ps -Zax | grep guix-daemon
1285 Monitor the SELinux log files as you run a command like @code{guix build
1286 hello} to convince yourself that SELinux permits all necessary
1289 @subsubsection Limitations
1290 @cindex SELinux, limitations
1292 This policy is not perfect. Here is a list of limitations or quirks
1293 that should be considered when deploying the provided SELinux policy for
1298 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1299 operations involve contexts that have anything to do with
1300 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1301 but it would be preferrable to define socket rules for only this label.
1304 @code{guix gc} cannot access arbitrary links to profiles. By design,
1305 the file label of the destination of a symlink is independent of the
1306 file label of the link itself. Although all profiles under
1307 $localstatedir are labelled, the links to these profiles inherit the
1308 label of the directory they are in. For links in the user’s home
1309 directory this will be @code{user_home_t}. But for links from the root
1310 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1311 directory, etc, this won’t work. @code{guix gc} would be prevented from
1312 reading and following these links.
1315 The daemon’s feature to listen for TCP connections might no longer work.
1316 This might require extra rules, because SELinux treats network sockets
1317 differently from files.
1320 Currently all files with a name matching the regular expression
1321 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1322 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1323 that name in any profile would be permitted to run in the
1324 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1325 build a package that provides this executable and convince a user to
1326 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1327 At that point SELinux could not prevent it from accessing files that are
1328 allowed for processes in that domain.
1330 We could generate a much more restrictive policy at installation time,
1331 so that only the @emph{exact} file name of the currently installed
1332 @code{guix-daemon} executable would be labelled with
1333 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1334 The downside is that root would have to install or upgrade the policy at
1335 installation time whenever the Guix package that provides the
1336 effectively running @code{guix-daemon} executable is upgraded.
1339 @node Invoking guix-daemon
1340 @section Invoking @command{guix-daemon}
1342 The @command{guix-daemon} program implements all the functionality to
1343 access the store. This includes launching build processes, running the
1344 garbage collector, querying the availability of a build result, etc. It
1345 is normally run as @code{root} like this:
1348 # guix-daemon --build-users-group=guixbuild
1352 For details on how to set it up, @pxref{Setting Up the Daemon}.
1355 @cindex container, build environment
1356 @cindex build environment
1357 @cindex reproducible builds
1358 By default, @command{guix-daemon} launches build processes under
1359 different UIDs, taken from the build group specified with
1360 @option{--build-users-group}. In addition, each build process is run in a
1361 chroot environment that only contains the subset of the store that the
1362 build process depends on, as specified by its derivation
1363 (@pxref{Programming Interface, derivation}), plus a set of specific
1364 system directories. By default, the latter contains @file{/dev} and
1365 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1366 @dfn{container}: in addition to having its own file system tree, it has
1367 a separate mount name space, its own PID name space, network name space,
1368 etc. This helps achieve reproducible builds (@pxref{Features}).
1370 When the daemon performs a build on behalf of the user, it creates a
1371 build directory under @file{/tmp} or under the directory specified by
1372 its @env{TMPDIR} environment variable. This directory is shared with
1373 the container for the duration of the build, though within the container,
1374 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1376 The build directory is automatically deleted upon completion, unless the
1377 build failed and the client specified @option{--keep-failed}
1378 (@pxref{Invoking guix build, @option{--keep-failed}}).
1380 The daemon listens for connections and spawns one sub-process for each session
1381 started by a client (one of the @command{guix} sub-commands). The
1382 @command{guix processes} command allows you to get an overview of the activity
1383 on your system by viewing each of the active sessions and clients.
1384 @xref{Invoking guix processes}, for more information.
1386 The following command-line options are supported:
1389 @item --build-users-group=@var{group}
1390 Take users from @var{group} to run build processes (@pxref{Setting Up
1391 the Daemon, build users}).
1393 @item --no-substitutes
1395 Do not use substitutes for build products. That is, always build things
1396 locally instead of allowing downloads of pre-built binaries
1397 (@pxref{Substitutes}).
1399 When the daemon runs with @option{--no-substitutes}, clients can still
1400 explicitly enable substitution @i{via} the @code{set-build-options}
1401 remote procedure call (@pxref{The Store}).
1403 @item --substitute-urls=@var{urls}
1404 @anchor{daemon-substitute-urls}
1405 Consider @var{urls} the default whitespace-separated list of substitute
1406 source URLs. When this option is omitted,
1407 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1409 This means that substitutes may be downloaded from @var{urls}, as long
1410 as they are signed by a trusted signature (@pxref{Substitutes}).
1414 Do not use offload builds to other machines (@pxref{Daemon Offload
1415 Setup}). That is, always build things locally instead of offloading
1416 builds to remote machines.
1418 @item --cache-failures
1419 Cache build failures. By default, only successful builds are cached.
1421 When this option is used, @command{guix gc --list-failures} can be used
1422 to query the set of store items marked as failed; @command{guix gc
1423 --clear-failures} removes store items from the set of cached failures.
1424 @xref{Invoking guix gc}.
1426 @item --cores=@var{n}
1428 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1431 The default value is @code{0}, but it may be overridden by clients, such
1432 as the @option{--cores} option of @command{guix build} (@pxref{Invoking
1435 The effect is to define the @env{NIX_BUILD_CORES} environment variable
1436 in the build process, which can then use it to exploit internal
1437 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1439 @item --max-jobs=@var{n}
1441 Allow at most @var{n} build jobs in parallel. The default value is
1442 @code{1}. Setting it to @code{0} means that no builds will be performed
1443 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1444 Setup}), or simply fail.
1446 @item --max-silent-time=@var{seconds}
1447 When the build or substitution process remains silent for more than
1448 @var{seconds}, terminate it and report a build failure.
1450 The default value is @code{0}, which disables the timeout.
1452 The value specified here can be overridden by clients (@pxref{Common
1453 Build Options, @option{--max-silent-time}}).
1455 @item --timeout=@var{seconds}
1456 Likewise, when the build or substitution process lasts for more than
1457 @var{seconds}, terminate it and report a build failure.
1459 The default value is @code{0}, which disables the timeout.
1461 The value specified here can be overridden by clients (@pxref{Common
1462 Build Options, @option{--timeout}}).
1464 @item --rounds=@var{N}
1465 Build each derivation @var{n} times in a row, and raise an error if
1466 consecutive build results are not bit-for-bit identical. Note that this
1467 setting can be overridden by clients such as @command{guix build}
1468 (@pxref{Invoking guix build}).
1470 When used in conjunction with @option{--keep-failed}, the differing
1471 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1472 This makes it easy to look for differences between the two results.
1475 Produce debugging output.
1477 This is useful to debug daemon start-up issues, but then it may be
1478 overridden by clients, for example the @option{--verbosity} option of
1479 @command{guix build} (@pxref{Invoking guix build}).
1481 @item --chroot-directory=@var{dir}
1482 Add @var{dir} to the build chroot.
1484 Doing this may change the result of build processes---for instance if
1485 they use optional dependencies found in @var{dir} when it is available,
1486 and not otherwise. For that reason, it is not recommended to do so.
1487 Instead, make sure that each derivation declares all the inputs that it
1490 @item --disable-chroot
1491 Disable chroot builds.
1493 Using this option is not recommended since, again, it would allow build
1494 processes to gain access to undeclared dependencies. It is necessary,
1495 though, when @command{guix-daemon} is running under an unprivileged user
1498 @item --log-compression=@var{type}
1499 Compress build logs according to @var{type}, one of @code{gzip},
1500 @code{bzip2}, or @code{none}.
1502 Unless @option{--lose-logs} is used, all the build logs are kept in the
1503 @var{localstatedir}. To save space, the daemon automatically compresses
1504 them with Bzip2 by default.
1506 @item --disable-deduplication
1507 @cindex deduplication
1508 Disable automatic file ``deduplication'' in the store.
1510 By default, files added to the store are automatically ``deduplicated'':
1511 if a newly added file is identical to another one found in the store,
1512 the daemon makes the new file a hard link to the other file. This can
1513 noticeably reduce disk usage, at the expense of slightly increased
1514 input/output load at the end of a build process. This option disables
1517 @item --gc-keep-outputs[=yes|no]
1518 Tell whether the garbage collector (GC) must keep outputs of live
1522 @cindex garbage collector roots
1523 When set to @code{yes}, the GC will keep the outputs of any live
1524 derivation available in the store---the @file{.drv} files. The default
1525 is @code{no}, meaning that derivation outputs are kept only if they are
1526 reachable from a GC root. @xref{Invoking guix gc}, for more on GC
1529 @item --gc-keep-derivations[=yes|no]
1530 Tell whether the garbage collector (GC) must keep derivations
1531 corresponding to live outputs.
1533 When set to @code{yes}, as is the case by default, the GC keeps
1534 derivations---i.e., @file{.drv} files---as long as at least one of their
1535 outputs is live. This allows users to keep track of the origins of
1536 items in their store. Setting it to @code{no} saves a bit of disk
1539 In this way, setting @option{--gc-keep-derivations} to @code{yes} causes
1540 liveness to flow from outputs to derivations, and setting
1541 @option{--gc-keep-outputs} to @code{yes} causes liveness to flow from
1542 derivations to outputs. When both are set to @code{yes}, the effect is
1543 to keep all the build prerequisites (the sources, compiler, libraries,
1544 and other build-time tools) of live objects in the store, regardless of
1545 whether these prerequisites are reachable from a GC root. This is
1546 convenient for developers since it saves rebuilds or downloads.
1548 @item --impersonate-linux-2.6
1549 On Linux-based systems, impersonate Linux 2.6. This means that the
1550 kernel's @command{uname} system call will report 2.6 as the release number.
1552 This might be helpful to build programs that (usually wrongfully) depend
1553 on the kernel version number.
1556 Do not keep build logs. By default they are kept under
1557 @file{@var{localstatedir}/guix/log}.
1559 @item --system=@var{system}
1560 Assume @var{system} as the current system type. By default it is the
1561 architecture/kernel pair found at configure time, such as
1562 @code{x86_64-linux}.
1564 @item --listen=@var{endpoint}
1565 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1566 as the file name of a Unix-domain socket if it starts with
1567 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1568 host name or host name and port to listen to. Here are a few examples:
1571 @item --listen=/gnu/var/daemon
1572 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1573 creating it if needed.
1575 @item --listen=localhost
1576 @cindex daemon, remote access
1577 @cindex remote access to the daemon
1578 @cindex daemon, cluster setup
1579 @cindex clusters, daemon setup
1580 Listen for TCP connections on the network interface corresponding to
1581 @code{localhost}, on port 44146.
1583 @item --listen=128.0.0.42:1234
1584 Listen for TCP connections on the network interface corresponding to
1585 @code{128.0.0.42}, on port 1234.
1588 This option can be repeated multiple times, in which case
1589 @command{guix-daemon} accepts connections on all the specified
1590 endpoints. Users can tell client commands what endpoint to connect to
1591 by setting the @env{GUIX_DAEMON_SOCKET} environment variable
1592 (@pxref{The Store, @env{GUIX_DAEMON_SOCKET}}).
1595 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1596 @option{--listen=@var{host}} is suitable on local networks, such as
1597 clusters, where only trusted nodes may connect to the build daemon. In
1598 other cases where remote access to the daemon is needed, we recommend
1599 using Unix-domain sockets along with SSH.
1602 When @option{--listen} is omitted, @command{guix-daemon} listens for
1603 connections on the Unix-domain socket located at
1604 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1608 @node Application Setup
1609 @section Application Setup
1611 @cindex foreign distro
1612 When using Guix on top of GNU/Linux distribution other than Guix System---a
1613 so-called @dfn{foreign distro}---a few additional steps are needed to
1614 get everything in place. Here are some of them.
1618 @anchor{locales-and-locpath}
1619 @cindex locales, when not on Guix System
1621 @vindex GUIX_LOCPATH
1622 Packages installed @i{via} Guix will not use the locale data of the
1623 host system. Instead, you must first install one of the locale packages
1624 available with Guix and then define the @env{GUIX_LOCPATH} environment
1628 $ guix install glibc-locales
1629 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1632 Note that the @code{glibc-locales} package contains data for all the
1633 locales supported by the GNU@tie{}libc and weighs in at around
1634 917@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1635 limited to a few UTF-8 locales.
1637 The @env{GUIX_LOCPATH} variable plays a role similar to @env{LOCPATH}
1638 (@pxref{Locale Names, @env{LOCPATH},, libc, The GNU C Library Reference
1639 Manual}). There are two important differences though:
1643 @env{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1644 provided by foreign distros. Thus, using @env{GUIX_LOCPATH} allows you
1645 to make sure the programs of the foreign distro will not end up loading
1646 incompatible locale data.
1649 libc suffixes each entry of @env{GUIX_LOCPATH} with @code{/X.Y}, where
1650 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1651 should your Guix profile contain a mixture of programs linked against
1652 different libc version, each libc version will only try to load locale
1653 data in the right format.
1656 This is important because the locale data format used by different libc
1657 versions may be incompatible.
1659 @subsection Name Service Switch
1661 @cindex name service switch, glibc
1662 @cindex NSS (name service switch), glibc
1663 @cindex nscd (name service caching daemon)
1664 @cindex name service caching daemon (nscd)
1665 When using Guix on a foreign distro, we @emph{strongly recommend} that
1666 the system run the GNU C library's @dfn{name service cache daemon},
1667 @command{nscd}, which should be listening on the
1668 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1669 installed with Guix may fail to look up host names or user accounts, or
1670 may even crash. The next paragraphs explain why.
1672 @cindex @file{nsswitch.conf}
1673 The GNU C library implements a @dfn{name service switch} (NSS), which is
1674 an extensible mechanism for ``name lookups'' in general: host name
1675 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1676 The GNU C Library Reference Manual}).
1678 @cindex Network information service (NIS)
1679 @cindex NIS (Network information service)
1680 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1681 lookup implementations: for example, the @code{nss-mdns} plugin allow
1682 resolution of @code{.local} host names, the @code{nis} plugin allows
1683 user account lookup using the Network information service (NIS), and so
1684 on. These extra ``lookup services'' are configured system-wide in
1685 @file{/etc/nsswitch.conf}, and all the programs running on the system
1686 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1689 When they perform a name lookup---for instance by calling the
1690 @code{getaddrinfo} function in C---applications first try to connect to
1691 the nscd; on success, nscd performs name lookups on their behalf. If
1692 the nscd is not running, then they perform the name lookup by
1693 themselves, by loading the name lookup services into their own address
1694 space and running it. These name lookup services---the
1695 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1696 the host system's C library, rather than from the C library the
1697 application is linked against (the C library coming from Guix).
1699 And this is where the problem is: if your application is linked against
1700 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1701 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1702 likely crash or have its name lookups fail unexpectedly.
1704 Running @command{nscd} on the system, among other advantages, eliminates
1705 this binary incompatibility problem because those @code{libnss_*.so}
1706 files are loaded in the @command{nscd} process, not in applications
1709 @subsection X11 Fonts
1712 The majority of graphical applications use Fontconfig to locate and
1713 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1714 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1715 by default. Thus, to allow graphical applications installed with Guix
1716 to display fonts, you have to install fonts with Guix as well.
1717 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1718 @code{font-gnu-freefont}.
1720 @cindex @code{fc-cache}
1722 Once you have installed or removed fonts, or when you notice an
1723 application that does not find fonts, you may need to install Fontconfig
1724 and to force an update of its font cache by running:
1727 guix install fontconfig
1731 To display text written in Chinese languages, Japanese, or Korean in
1732 graphical applications, consider installing
1733 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1734 has multiple outputs, one per language family (@pxref{Packages with
1735 Multiple Outputs}). For instance, the following command installs fonts
1736 for Chinese languages:
1739 guix install font-adobe-source-han-sans:cn
1742 @cindex @code{xterm}
1743 Older programs such as @command{xterm} do not use Fontconfig and instead
1744 rely on server-side font rendering. Such programs require to specify a
1745 full name of a font using XLFD (X Logical Font Description), like this:
1748 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1751 To be able to use such full names for the TrueType fonts installed in
1752 your Guix profile, you need to extend the font path of the X server:
1754 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1755 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1757 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1760 @cindex @code{xlsfonts}
1761 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1762 to make sure your TrueType fonts are listed there.
1765 @subsection X.509 Certificates
1767 @cindex @code{nss-certs}
1768 The @code{nss-certs} package provides X.509 certificates, which allow
1769 programs to authenticate Web servers accessed over HTTPS.
1771 When using Guix on a foreign distro, you can install this package and
1772 define the relevant environment variables so that packages know where to
1773 look for certificates. @xref{X.509 Certificates}, for detailed
1776 @subsection Emacs Packages
1778 @cindex @code{emacs}
1779 When you install Emacs packages with Guix, the Elisp files are placed
1780 under the @file{share/emacs/site-lisp/} directory of the profile in
1781 which they are installed. The Elisp libraries are made available to
1782 Emacs through the @env{EMACSLOADPATH} environment variable, which is
1783 set when installing Emacs itself.
1785 Additionally, autoload definitions are automatically evaluated at the
1786 initialization of Emacs, by the Guix-specific
1787 @code{guix-emacs-autoload-packages} procedure. If, for some reason, you
1788 want to avoid auto-loading the Emacs packages installed with Guix, you
1789 can do so by running Emacs with the @option{--no-site-file} option
1790 (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1793 @node Upgrading Guix
1794 @section Upgrading Guix
1796 @cindex Upgrading Guix, on a foreign distro
1798 To upgrade Guix, run:
1804 @xref{Invoking guix pull}, for more information.
1806 @cindex upgrading Guix for the root user, on a foreign distro
1807 @cindex upgrading the Guix daemon, on a foreign distro
1808 @cindex @command{guix pull} for the root user, on a foreign distro
1810 On a foreign distro, you can upgrade the build daemon by running:
1817 followed by (assuming your distro uses the systemd service management
1821 systemctl restart guix-daemon.service
1824 On Guix System, upgrading the daemon is achieved by reconfiguring the
1825 system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
1829 @c *********************************************************************
1830 @node System Installation
1831 @chapter System Installation
1833 @cindex installing Guix System
1834 @cindex Guix System, installation
1835 This section explains how to install Guix System
1836 on a machine. Guix, as a package manager, can
1837 also be installed on top of a running GNU/Linux system,
1838 @pxref{Installation}.
1842 @c This paragraph is for people reading this from tty2 of the
1843 @c installation image.
1844 You are reading this documentation with an Info reader. For details on
1845 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1846 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1847 Info}. Hit @kbd{l} afterwards to come back here.
1849 Alternatively, run @command{info info} in another tty to keep the manual
1855 * Limitations:: What you can expect.
1856 * Hardware Considerations:: Supported hardware.
1857 * USB Stick and DVD Installation:: Preparing the installation medium.
1858 * Preparing for Installation:: Networking, partitioning, etc.
1859 * Guided Graphical Installation:: Easy graphical installation.
1860 * Manual Installation:: Manual installation for wizards.
1861 * After System Installation:: When installation succeeded.
1862 * Installing Guix in a VM:: Guix System playground.
1863 * Building the Installation Image:: How this comes to be.
1867 @section Limitations
1869 We consider Guix System to be ready for a wide range of ``desktop'' and server
1870 use cases. The reliability guarantees it provides---transactional upgrades
1871 and rollbacks, reproducibility---make it a solid foundation.
1873 Nevertheless, before you proceed with the installation, be aware of the
1874 following noteworthy limitations applicable to version @value{VERSION}:
1878 Support for the Logical Volume Manager (LVM) is missing.
1881 More and more system services are provided (@pxref{Services}), but some
1885 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1886 as well as a number of X11 window managers. However, KDE is currently
1890 More than a disclaimer, this is an invitation to report issues (and success
1891 stories!), and to join us in improving it. @xref{Contributing}, for more
1895 @node Hardware Considerations
1896 @section Hardware Considerations
1898 @cindex hardware support on Guix System
1899 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1900 builds around the kernel Linux-libre, which means that only hardware for
1901 which free software drivers and firmware exist is supported. Nowadays,
1902 a wide range of off-the-shelf hardware is supported on
1903 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1904 Ethernet controllers. Unfortunately, there are still areas where
1905 hardware vendors deny users control over their own computing, and such
1906 hardware is not supported on Guix System.
1908 @cindex WiFi, hardware support
1909 One of the main areas where free drivers or firmware are lacking is WiFi
1910 devices. WiFi devices known to work include those using Atheros chips
1911 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1912 driver, and those using Broadcom/AirForce chips (BCM43xx with
1913 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1914 Linux-libre driver. Free firmware exists for both and is available
1915 out-of-the-box on Guix System, as part of @code{%base-firmware}
1916 (@pxref{operating-system Reference, @code{firmware}}).
1918 @cindex RYF, Respects Your Freedom
1919 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1920 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1921 certification program for hardware products that respect your freedom
1922 and your privacy and ensure that you have control over your device. We
1923 encourage you to check the list of RYF-certified devices.
1925 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1926 web site. It contains a catalog of hardware devices with information
1927 about their support in GNU/Linux.
1930 @node USB Stick and DVD Installation
1931 @section USB Stick and DVD Installation
1933 An ISO-9660 installation image that can be written to a USB stick or
1934 burnt to a DVD can be downloaded from
1935 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz},
1936 where you can replace @code{x86_64-linux} with one of:
1940 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1943 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1946 @c start duplication of authentication part from ``Binary Installation''
1947 Make sure to download the associated @file{.sig} file and to verify the
1948 authenticity of the image against it, along these lines:
1951 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
1952 $ gpg --verify guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
1955 If that command fails because you do not have the required public key,
1956 then run this command to import it:
1959 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
1960 -qO - | gpg --import -
1964 and rerun the @code{gpg --verify} command.
1966 Take note that a warning like ``This key is not certified with a trusted
1967 signature!'' is normal.
1971 This image contains the tools necessary for an installation.
1972 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1974 @unnumberedsubsec Copying to a USB Stick
1976 To copy the image to a USB stick, follow these steps:
1980 Decompress the image using the @command{xz} command:
1983 xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
1987 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1988 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1989 copy the image with:
1992 dd if=guix-system-install-@value{VERSION}.x86_64-linux.iso of=/dev/sdX status=progress
1996 Access to @file{/dev/sdX} usually requires root privileges.
1999 @unnumberedsubsec Burning on a DVD
2001 To copy the image to a DVD, follow these steps:
2005 Decompress the image using the @command{xz} command:
2008 xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
2012 Insert a blank DVD into your machine, and determine
2013 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
2014 copy the image with:
2017 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.x86_64-linux.iso
2020 Access to @file{/dev/srX} usually requires root privileges.
2023 @unnumberedsubsec Booting
2025 Once this is done, you should be able to reboot the system and boot from
2026 the USB stick or DVD. The latter usually requires you to get in the
2027 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
2028 In order to boot from Libreboot, switch to the command mode by pressing
2029 the @kbd{c} key and type @command{search_grub usb}.
2031 @xref{Installing Guix in a VM}, if, instead, you would like to install
2032 Guix System in a virtual machine (VM).
2035 @node Preparing for Installation
2036 @section Preparing for Installation
2038 Once you have booted, you can use the guided graphical installer, which makes
2039 it easy to get started (@pxref{Guided Graphical Installation}). Alternatively,
2040 if you are already familiar with GNU/Linux and if you want more control than
2041 what the graphical installer provides, you can choose the ``manual''
2042 installation process (@pxref{Manual Installation}).
2044 The graphical installer is available on TTY1. You can obtain root shells on
2045 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
2046 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
2047 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
2048 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2049 which allows you to select text with the left mouse button and to paste it
2050 with the middle button.
2053 Installation requires access to the Internet so that any missing
2054 dependencies of your system configuration can be downloaded. See the
2055 ``Networking'' section below.
2058 @node Guided Graphical Installation
2059 @section Guided Graphical Installation
2061 The graphical installer is a text-based user interface. It will guide you,
2062 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2064 The first dialog boxes allow you to set up the system as you use it during the
2065 installation: you can choose the language, keyboard layout, and set up
2066 networking, which will be used during the installation. The image below shows
2067 the networking dialog.
2069 @image{images/installer-network,5in,, networking setup with the graphical installer}
2071 Later steps allow you to partition your hard disk, as shown in the image
2072 below, to choose whether or not to use encrypted file systems, to enter the
2073 host name and root password, and to create an additional account, among other
2076 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2078 Note that, at any time, the installer allows you to exit the current
2079 installation step and resume at a previous step, as show in the image below.
2081 @image{images/installer-resume,5in,, resuming the installation process}
2083 Once you're done, the installer produces an operating system configuration and
2084 displays it (@pxref{Using the Configuration System}). At that point you can
2085 hit ``OK'' and installation will proceed. On success, you can reboot into the
2086 new system and enjoy. @xref{After System Installation}, for what's next!
2089 @node Manual Installation
2090 @section Manual Installation
2092 This section describes how you would ``manually'' install GNU@tie{}Guix System
2093 on your machine. This option requires familiarity with GNU/Linux, with the
2094 shell, and with common administration tools. If you think this is not for
2095 you, consider using the guided graphical installer (@pxref{Guided Graphical
2098 The installation system provides root shells on TTYs 3 to 6; press
2099 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2100 many common tools needed to install the system. But it is also a full-blown
2101 Guix System, which means that you can install additional packages, should you
2102 need it, using @command{guix package} (@pxref{Invoking guix package}).
2105 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2106 * Proceeding with the Installation:: Installing.
2109 @node Keyboard Layout and Networking and Partitioning
2110 @subsection Keyboard Layout, Networking, and Partitioning
2112 Before you can install the system, you may want to adjust the keyboard layout,
2113 set up networking, and partition your target hard disk. This section will
2114 guide you through this.
2116 @subsubsection Keyboard Layout
2118 @cindex keyboard layout
2119 The installation image uses the US qwerty keyboard layout. If you want
2120 to change it, you can use the @command{loadkeys} command. For example,
2121 the following command selects the Dvorak keyboard layout:
2127 See the files under @file{/run/current-system/profile/share/keymaps} for
2128 a list of available keyboard layouts. Run @command{man loadkeys} for
2131 @subsubsection Networking
2133 Run the following command to see what your network interfaces are called:
2140 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2146 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2147 Wired interfaces have a name starting with @samp{e}; for example, the
2148 interface corresponding to the first on-board Ethernet controller is
2149 called @samp{eno1}. Wireless interfaces have a name starting with
2150 @samp{w}, like @samp{w1p2s0}.
2153 @item Wired connection
2154 To configure a wired network run the following command, substituting
2155 @var{interface} with the name of the wired interface you want to use.
2158 ifconfig @var{interface} up
2162 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2165 ip link set @var{interface} up
2168 @item Wireless connection
2171 To configure wireless networking, you can create a configuration file
2172 for the @command{wpa_supplicant} configuration tool (its location is not
2173 important) using one of the available text editors such as
2177 nano wpa_supplicant.conf
2180 As an example, the following stanza can go to this file and will work
2181 for many wireless networks, provided you give the actual SSID and
2182 passphrase for the network you are connecting to:
2186 ssid="@var{my-ssid}"
2188 psk="the network's secret passphrase"
2192 Start the wireless service and run it in the background with the
2193 following command (substitute @var{interface} with the name of the
2194 network interface you want to use):
2197 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2200 Run @command{man wpa_supplicant} for more information.
2204 At this point, you need to acquire an IP address. On a network where IP
2205 addresses are automatically assigned @i{via} DHCP, you can run:
2208 dhclient -v @var{interface}
2211 Try to ping a server to see if networking is up and running:
2217 Setting up network access is almost always a requirement because the
2218 image does not contain all the software and tools that may be needed.
2220 @cindex proxy, during system installation
2221 If you need HTTP and HTTPS access to go through a proxy, run the
2225 herd set-http-proxy guix-daemon @var{URL}
2229 where @var{URL} is the proxy URL, for example
2230 @code{http://example.org:8118}.
2232 @cindex installing over SSH
2233 If you want to, you can continue the installation remotely by starting
2237 herd start ssh-daemon
2240 Make sure to either set a password with @command{passwd}, or configure
2241 OpenSSH public key authentication before logging in.
2243 @subsubsection Disk Partitioning
2245 Unless this has already been done, the next step is to partition, and
2246 then format the target partition(s).
2248 The installation image includes several partitioning tools, including
2249 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2250 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2251 the partition layout you want:
2257 If your disk uses the GUID Partition Table (GPT) format and you plan to
2258 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2259 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2262 @cindex EFI, installation
2263 @cindex UEFI, installation
2264 @cindex ESP, EFI system partition
2265 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2266 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2267 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2270 parted /dev/sda set 1 esp on
2274 @vindex grub-bootloader
2275 @vindex grub-efi-bootloader
2276 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2277 @file{/sys/firmware/efi} exists in the installation image, then you should
2278 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2279 Otherwise you should use the BIOS-based GRUB, known as
2280 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2284 Once you are done partitioning the target hard disk drive, you have to
2285 create a file system on the relevant partition(s)@footnote{Currently
2286 Guix System only supports ext4, btrfs, and JFS file systems. In particular,
2287 code that reads file system UUIDs and labels only works for these file system
2288 types.}. For the ESP, if you have one and assuming it is
2289 @file{/dev/sda1}, run:
2292 mkfs.fat -F32 /dev/sda1
2295 For the root file system, ext4 is the most widely used format. Other
2296 file systems, such as Btrfs, support compression, which is reported to
2297 nicely complement file deduplication that the daemon performs
2298 independently of the file system (@pxref{Invoking guix-daemon,
2301 Preferably, assign file systems a label so that you can easily and
2302 reliably refer to them in @code{file-system} declarations (@pxref{File
2303 Systems}). This is typically done using the @code{-L} option of
2304 @command{mkfs.ext4} and related commands. So, assuming the target root
2305 partition lives at @file{/dev/sda2}, a file system with the label
2306 @code{my-root} can be created with:
2309 mkfs.ext4 -L my-root /dev/sda2
2312 @cindex encrypted disk
2313 If you are instead planning to encrypt the root partition, you can use
2314 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2315 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2316 @code{man cryptsetup}} for more information). Assuming you want to
2317 store the root partition on @file{/dev/sda2}, the command sequence would
2318 be along these lines:
2321 cryptsetup luksFormat /dev/sda2
2322 cryptsetup open --type luks /dev/sda2 my-partition
2323 mkfs.ext4 -L my-root /dev/mapper/my-partition
2326 Once that is done, mount the target file system under @file{/mnt}
2327 with a command like (again, assuming @code{my-root} is the label of the
2331 mount LABEL=my-root /mnt
2334 Also mount any other file systems you would like to use on the target
2335 system relative to this path. If you have opted for @file{/boot/efi} as an
2336 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2337 found by @code{guix system init} afterwards.
2339 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2340 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2341 sure to initialize them with @command{mkswap}. Assuming you have one
2342 swap partition on @file{/dev/sda3}, you would run:
2349 Alternatively, you may use a swap file. For example, assuming that in
2350 the new system you want to use the file @file{/swapfile} as a swap file,
2351 you would run@footnote{This example will work for many types of file
2352 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2353 btrfs), the required steps may be different. For details, see the
2354 manual pages for @command{mkswap} and @command{swapon}.}:
2357 # This is 10 GiB of swap space. Adjust "count" to change the size.
2358 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2359 # For security, make the file readable and writable only by root.
2360 chmod 600 /mnt/swapfile
2361 mkswap /mnt/swapfile
2362 swapon /mnt/swapfile
2365 Note that if you have encrypted the root partition and created a swap
2366 file in its file system as described above, then the encryption also
2367 protects the swap file, just like any other file in that file system.
2369 @node Proceeding with the Installation
2370 @subsection Proceeding with the Installation
2372 With the target partitions ready and the target root mounted on
2373 @file{/mnt}, we're ready to go. First, run:
2376 herd start cow-store /mnt
2379 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2380 during the installation phase are written to the target disk on @file{/mnt}
2381 rather than kept in memory. This is necessary because the first phase of
2382 the @command{guix system init} command (see below) entails downloads or
2383 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2385 Next, you have to edit a file and
2386 provide the declaration of the operating system to be installed. To
2387 that end, the installation system comes with three text editors. We
2388 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2389 supports syntax highlighting and parentheses matching; other editors
2390 include GNU Zile (an Emacs clone), and
2391 nvi (a clone of the original BSD @command{vi} editor).
2392 We strongly recommend storing that file on the target root file system, say,
2393 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2394 configuration file once you have rebooted into the newly-installed system.
2396 @xref{Using the Configuration System}, for an overview of the
2397 configuration file. The example configurations discussed in that
2398 section are available under @file{/etc/configuration} in the
2399 installation image. Thus, to get started with a system configuration
2400 providing a graphical display server (a ``desktop'' system), you can run
2401 something along these lines:
2405 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2406 # nano /mnt/etc/config.scm
2409 You should pay attention to what your configuration file contains, and
2414 Make sure the @code{bootloader-configuration} form refers to the target
2415 you want to install GRUB on. It should mention @code{grub-bootloader} if
2416 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2417 for newer UEFI systems. For legacy systems, the @code{target} field
2418 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2419 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2420 currently mounted and a @code{file-system} entry is specified in your
2424 Be sure that your file system labels match the value of their respective
2425 @code{device} fields in your @code{file-system} configuration, assuming
2426 your @code{file-system} configuration uses the @code{file-system-label}
2427 procedure in its @code{device} field.
2430 If there are encrypted or RAID partitions, make sure to add a
2431 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2434 Once you are done preparing the configuration file, the new system must
2435 be initialized (remember that the target root file system is mounted
2439 guix system init /mnt/etc/config.scm /mnt
2443 This copies all the necessary files and installs GRUB on
2444 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2445 more information, @pxref{Invoking guix system}. This command may trigger
2446 downloads or builds of missing packages, which can take some time.
2448 Once that command has completed---and hopefully succeeded!---you can run
2449 @command{reboot} and boot into the new system. The @code{root} password
2450 in the new system is initially empty; other users' passwords need to be
2451 initialized by running the @command{passwd} command as @code{root},
2452 unless your configuration specifies otherwise
2453 (@pxref{user-account-password, user account passwords}).
2454 @xref{After System Installation}, for what's next!
2457 @node After System Installation
2458 @section After System Installation
2460 Success, you've now booted into Guix System! From then on, you can update the
2461 system whenever you want by running, say:
2465 sudo guix system reconfigure /etc/config.scm
2469 This builds a new system generation with the latest packages and services
2470 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2471 your system includes the latest security updates (@pxref{Security Updates}).
2473 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2475 @cindex sudo vs. @command{guix pull}
2476 Note that @command{sudo guix} runs your user's @command{guix} command and
2477 @emph{not} root's, because @command{sudo} leaves @env{PATH} unchanged. To
2478 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2480 The difference matters here, because @command{guix pull} updates
2481 the @command{guix} command and package definitions only for the user it is ran
2482 as. This means that if you choose to use @command{guix system reconfigure} in
2483 root's login shell, you'll need to @command{guix pull} separately.
2486 Now, @pxref{Getting Started}, and
2487 join us on @code{#guix} on the Freenode IRC network or on
2488 @email{guix-devel@@gnu.org} to share your experience!
2491 @node Installing Guix in a VM
2492 @section Installing Guix in a Virtual Machine
2494 @cindex virtual machine, Guix System installation
2495 @cindex virtual private server (VPS)
2496 @cindex VPS (virtual private server)
2497 If you'd like to install Guix System in a virtual machine (VM) or on a
2498 virtual private server (VPS) rather than on your beloved machine, this
2501 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2502 disk image, follow these steps:
2506 First, retrieve and decompress the Guix system installation image as
2507 described previously (@pxref{USB Stick and DVD Installation}).
2510 Create a disk image that will hold the installed system. To make a
2511 qcow2-formatted disk image, use the @command{qemu-img} command:
2514 qemu-img create -f qcow2 guix-system.img 50G
2517 The resulting file will be much smaller than 50 GB (typically less than
2518 1 MB), but it will grow as the virtualized storage device is filled up.
2521 Boot the USB installation image in an VM:
2524 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2525 -nic user,model=virtio-net-pci -boot menu=on,order=d \
2526 -drive file=guix-system.img \
2527 -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
2530 @code{-enable-kvm} is optional, but significantly improves performance,
2531 @pxref{Running Guix in a VM}.
2534 You're now root in the VM, proceed with the installation process.
2535 @xref{Preparing for Installation}, and follow the instructions.
2538 Once installation is complete, you can boot the system that's on your
2539 @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
2542 @node Building the Installation Image
2543 @section Building the Installation Image
2545 @cindex installation image
2546 The installation image described above was built using the @command{guix
2547 system} command, specifically:
2550 guix system disk-image --file-system-type=iso9660 \
2551 gnu/system/install.scm
2554 Have a look at @file{gnu/system/install.scm} in the source tree,
2555 and see also @ref{Invoking guix system} for more information
2556 about the installation image.
2558 @section Building the Installation Image for ARM Boards
2560 Many ARM boards require a specific variant of the
2561 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2563 If you build a disk image and the bootloader is not available otherwise
2564 (on another boot drive etc), it's advisable to build an image that
2565 includes the bootloader, specifically:
2568 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2571 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2572 board, a list of possible boards will be printed.
2574 @c *********************************************************************
2575 @node Getting Started
2576 @chapter Getting Started
2578 Presumably, you've reached this section because either you have
2579 installed Guix on top of another distribution (@pxref{Installation}), or
2580 you've installed the standalone Guix System (@pxref{System
2581 Installation}). It's time for you to get started using Guix and this
2582 section aims to help you do that and give you a feel of what it's like.
2584 Guix is about installing software, so probably the first thing you'll
2585 want to do is to actually look for software. Let's say you're looking
2586 for a text editor, you can run:
2589 guix search text editor
2592 This command shows you a number of matching @dfn{packages}, each time
2593 showing the package's name, version, a description, and additional info.
2594 Once you've found out the one you want to use, let's say Emacs (ah ha!),
2595 you can go ahead and install it (run this command as a regular user,
2596 @emph{no need for root privileges}!):
2602 You've installed your first package, congrats! In the process, you've
2603 probably noticed that Guix downloaded pre-built binaries; or, if you
2604 explicitly chose to @emph{not} use pre-built binaries, then probably
2605 Guix is still building software (@pxref{Substitutes}, for more info).
2607 Unless you're using Guix System, the @command{guix install} command must
2608 have printed this hint:
2611 hint: Consider setting the necessary environment variables by running:
2613 GUIX_PROFILE="$HOME/.guix-profile"
2614 . "$GUIX_PROFILE/etc/profile"
2616 Alternately, see `guix package --search-paths -p "$HOME/.guix-profile"'.
2619 Indeed, you must now tell your shell where @command{emacs} and other
2620 programs installed with Guix are to be found. Pasting the two lines
2621 above will do just that: it will add
2622 @code{$HOME/.guix-profile/bin}---which is where the installed package
2623 is---to the @code{PATH} environment variable. You can paste these two
2624 lines in your shell so they take effect right away, but more importantly
2625 you should add them to @file{~/.bash_profile} (or equivalent file if you
2626 do not use Bash) so that environment variables are set next time you
2627 spawn a shell. You only need to do this once and other search paths
2628 environment variables will be taken care of similarly---e.g., if you
2629 eventually install @code{python} and Python libraries, @code{PYTHONPATH}
2632 You can go on installing packages at your will. To list installed
2636 guix package --list-installed
2639 To remove a package, you would unsurprisingly run @command{guix remove}.
2640 A distinguishing feature is the ability to @dfn{roll back} any operation
2641 you made---installation, removal, upgrade---by simply typing:
2644 guix package --roll-back
2647 This is because each operation is in fact a @dfn{transaction} that
2648 creates a new @dfn{generation}. These generations and the difference
2649 between them can be displayed by running:
2652 guix package --list-generations
2655 Now you know the basics of package management!
2657 @quotation Going further
2658 @xref{Package Management}, for more about package management. You may
2659 like @dfn{declarative} package management with @command{guix package
2660 --manifest}, managing separate @dfn{profiles} with @option{--profile},
2661 deleting old generations, collecting garbage, and other nifty features
2662 that will come in handy as you become more familiar with Guix. If you
2663 are a developer, @pxref{Development} for additional tools. And if
2664 you're curious, @pxref{Features}, to peek under the hood.
2667 Once you've installed a set of packages, you will want to periodically
2668 @emph{upgrade} them to the latest and greatest version. To do that, you
2669 will first pull the latest revision of Guix and its package collection:
2675 The end result is a new @command{guix} command, under
2676 @file{~/.config/guix/current/bin}. Unless you're on Guix System, the
2677 first time you run @command{guix pull}, be sure to follow the hint that
2678 the command prints and, similar to what we saw above, paste these two
2679 lines in your terminal and @file{.bash_profile}:
2682 GUIX_PROFILE="$HOME/.config/guix/current/etc/profile"
2683 . "$GUIX_PROFILE/etc/profile"
2687 You must also instruct your shell to point to this new @command{guix}:
2693 At this point, you're running a brand new Guix. You can thus go ahead
2694 and actually upgrade all the packages you previously installed:
2700 As you run this command, you will see that binaries are downloaded (or
2701 perhaps some packages are built), and eventually you end up with the
2702 upgraded packages. Should one of these upgraded packages not be to your
2703 liking, remember you can always roll back!
2705 You can display the exact revision of Guix you're currently using by
2712 The information it displays is @emph{all it takes to reproduce the exact
2713 same Guix}, be it at a different point in time or on a different
2716 @quotation Going further
2717 @xref{Invoking guix pull}, for more information. @xref{Channels}, on
2718 how to specify additional @dfn{channels} to pull packages from, how to
2719 replicate Guix, and more. You may also find @command{time-machine}
2720 handy (@pxref{Invoking guix time-machine}).
2723 If you installed Guix System, one of the first things you'll want to do
2724 is to upgrade your system. Once you've run @command{guix pull} to get
2725 the latest Guix, you can upgrade the system like this:
2728 sudo guix system reconfigure /etc/config.scm
2731 Upon completion, the system runs the latest versions of its software
2732 packages. When you eventually reboot, you'll notice a sub-menu in the
2733 bootloader that reads ``Old system generations'': it's what allows you
2734 to boot @emph{an older generation of your system}, should the latest
2735 generation be ``broken'' or otherwise unsatisfying. Just like for
2736 packages, you can always @emph{roll back} to a previous generation
2737 @emph{of the whole system}:
2740 sudo guix system roll-back
2743 There are many things you'll probably want to tweak on your system:
2744 adding new user accounts, adding new system services, fiddling with the
2745 configuration of those services, etc. The system configuration is
2746 @emph{entirely} described in the @file{/etc/config.scm} file.
2747 @xref{Using the Configuration System}, to learn how to change it.
2749 Now you know enough to get started!
2751 @quotation Resources
2752 The rest of this manual provides a reference for all things Guix. Here
2753 are some additional resources you may find useful:
2757 @xref{Top,,, guix-cookbook, The GNU Guix Cookbook}, for a list of
2758 ``how-to'' style of recipes for a variety of applications.
2761 The @uref{https://guix.gnu.org/guix-refcard.pdf, GNU Guix Reference
2762 Card} lists in two pages most of the commands and options you'll ever
2766 The web site contains @uref{https://guix.gnu.org/en/videos/,
2767 instructional videos} covering topics such as everyday use of Guix, how
2768 to get help, and how to become a contributor.
2771 @xref{Documentation}, to learn how to access documentation on your
2775 We hope you will enjoy Guix as much as the community enjoys building it!
2778 @c *********************************************************************
2779 @node Package Management
2780 @chapter Package Management
2783 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2784 remove software packages, without having to know about their build
2785 procedures or dependencies. Guix also goes beyond this obvious set of
2788 This chapter describes the main features of Guix, as well as the
2789 package management tools it provides. Along with the command-line
2790 interface described below (@pxref{Invoking guix package, @code{guix
2791 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2792 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2793 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2797 guix install emacs-guix
2801 * Features:: How Guix will make your life brighter.
2802 * Invoking guix package:: Package installation, removal, etc.
2803 * Substitutes:: Downloading pre-built binaries.
2804 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2805 * Invoking guix gc:: Running the garbage collector.
2806 * Invoking guix pull:: Fetching the latest Guix and distribution.
2807 * Channels:: Customizing the package collection.
2808 * Invoking guix time-machine:: Running an older revision of Guix.
2809 * Inferiors:: Interacting with another revision of Guix.
2810 * Invoking guix describe:: Display information about your Guix revision.
2811 * Invoking guix archive:: Exporting and importing store files.
2817 Here we assume you've already made your first steps with Guix
2818 (@pxref{Getting Started}) and would like to get an overview about what's
2819 going on under the hood.
2821 When using Guix, each package ends up in the @dfn{package store}, in its
2822 own directory---something that resembles
2823 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2825 Instead of referring to these directories, users have their own
2826 @dfn{profile}, which points to the packages that they actually want to
2827 use. These profiles are stored within each user's home directory, at
2828 @code{$HOME/.guix-profile}.
2830 For example, @code{alice} installs GCC 4.7.2. As a result,
2831 @file{/home/alice/.guix-profile/bin/gcc} points to
2832 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2833 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2834 simply continues to point to
2835 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2836 coexist on the same system without any interference.
2838 The @command{guix package} command is the central tool to manage
2839 packages (@pxref{Invoking guix package}). It operates on the per-user
2840 profiles, and can be used @emph{with normal user privileges}.
2842 @cindex transactions
2843 The command provides the obvious install, remove, and upgrade
2844 operations. Each invocation is actually a @emph{transaction}: either
2845 the specified operation succeeds, or nothing happens. Thus, if the
2846 @command{guix package} process is terminated during the transaction,
2847 or if a power outage occurs during the transaction, then the user's
2848 profile remains in its previous state, and remains usable.
2850 In addition, any package transaction may be @emph{rolled back}. So, if,
2851 for example, an upgrade installs a new version of a package that turns
2852 out to have a serious bug, users may roll back to the previous instance
2853 of their profile, which was known to work well. Similarly, the global
2854 system configuration on Guix is subject to
2855 transactional upgrades and roll-back
2856 (@pxref{Using the Configuration System}).
2858 All packages in the package store may be @emph{garbage-collected}.
2859 Guix can determine which packages are still referenced by user
2860 profiles, and remove those that are provably no longer referenced
2861 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2862 generations of their profile so that the packages they refer to can be
2865 @cindex reproducibility
2866 @cindex reproducible builds
2867 Guix takes a @dfn{purely functional} approach to package
2868 management, as described in the introduction (@pxref{Introduction}).
2869 Each @file{/gnu/store} package directory name contains a hash of all the
2870 inputs that were used to build that package---compiler, libraries, build
2871 scripts, etc. This direct correspondence allows users to make sure a
2872 given package installation matches the current state of their
2873 distribution. It also helps maximize @dfn{build reproducibility}:
2874 thanks to the isolated build environments that are used, a given build
2875 is likely to yield bit-identical files when performed on different
2876 machines (@pxref{Invoking guix-daemon, container}).
2879 This foundation allows Guix to support @dfn{transparent binary/source
2880 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2881 available from an external source---a @dfn{substitute}, Guix just
2882 downloads it and unpacks it;
2883 otherwise, it builds the package from source, locally
2884 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2885 reproducible, users do not have to trust servers that provide
2886 substitutes: they can force a local build and @emph{challenge} providers
2887 (@pxref{Invoking guix challenge}).
2889 Control over the build environment is a feature that is also useful for
2890 developers. The @command{guix environment} command allows developers of
2891 a package to quickly set up the right development environment for their
2892 package, without having to manually install the dependencies of the
2893 package into their profile (@pxref{Invoking guix environment}).
2895 @cindex replication, of software environments
2896 @cindex provenance tracking, of software artifacts
2897 All of Guix and its package definitions is version-controlled, and
2898 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2899 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2900 Guix instance on a different machine or at a later point in time, which in
2901 turn allows you to @emph{replicate complete software environments}, while
2902 retaining precise @dfn{provenance tracking} of the software.
2904 @node Invoking guix package
2905 @section Invoking @command{guix package}
2907 @cindex installing packages
2908 @cindex removing packages
2909 @cindex package installation
2910 @cindex package removal
2911 The @command{guix package} command is the tool that allows users to
2912 install, upgrade, and remove packages, as well as rolling back to
2913 previous configurations. It operates only on the user's own profile,
2914 and works with normal user privileges (@pxref{Features}). Its syntax
2918 guix package @var{options}
2921 @cindex transactions
2922 Primarily, @var{options} specifies the operations to be performed during
2923 the transaction. Upon completion, a new profile is created, but
2924 previous @dfn{generations} of the profile remain available, should the user
2927 For example, to remove @code{lua} and install @code{guile} and
2928 @code{guile-cairo} in a single transaction:
2931 guix package -r lua -i guile guile-cairo
2934 @cindex aliases, for @command{guix package}
2935 For your convenience, we also provide the following aliases:
2939 @command{guix search} is an alias for @command{guix package -s},
2941 @command{guix install} is an alias for @command{guix package -i},
2943 @command{guix remove} is an alias for @command{guix package -r},
2945 @command{guix upgrade} is an alias for @command{guix package -u},
2947 and @command{guix show} is an alias for @command{guix package --show=}.
2950 These aliases are less expressive than @command{guix package} and provide
2951 fewer options, so in some cases you'll probably want to use @command{guix
2954 @command{guix package} also supports a @dfn{declarative approach}
2955 whereby the user specifies the exact set of packages to be available and
2956 passes it @i{via} the @option{--manifest} option
2957 (@pxref{profile-manifest, @option{--manifest}}).
2960 For each user, a symlink to the user's default profile is automatically
2961 created in @file{$HOME/.guix-profile}. This symlink always points to the
2962 current generation of the user's default profile. Thus, users can add
2963 @file{$HOME/.guix-profile/bin} to their @env{PATH} environment
2964 variable, and so on.
2965 @cindex search paths
2966 If you are not using Guix System, consider adding the
2967 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2968 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2969 shells get all the right environment variable definitions:
2972 GUIX_PROFILE="$HOME/.guix-profile" ; \
2973 source "$HOME/.guix-profile/etc/profile"
2976 In a multi-user setup, user profiles are stored in a place registered as
2977 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2978 to (@pxref{Invoking guix gc}). That directory is normally
2979 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2980 @var{localstatedir} is the value passed to @code{configure} as
2981 @option{--localstatedir}, and @var{user} is the user name. The
2982 @file{per-user} directory is created when @command{guix-daemon} is
2983 started, and the @var{user} sub-directory is created by @command{guix
2986 The @var{options} can be among the following:
2990 @item --install=@var{package} @dots{}
2991 @itemx -i @var{package} @dots{}
2992 Install the specified @var{package}s.
2994 Each @var{package} may specify either a simple package name, such as
2995 @code{guile}, or a package name followed by an at-sign and version number,
2996 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2997 case, the newest version prefixed by @code{1.8} is selected).
2999 If no version number is specified, the
3000 newest available version will be selected. In addition, @var{package}
3001 may contain a colon, followed by the name of one of the outputs of the
3002 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
3003 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
3004 name (and optionally version) are searched for among the GNU
3005 distribution modules (@pxref{Package Modules}).
3007 @cindex propagated inputs
3008 Sometimes packages have @dfn{propagated inputs}: these are dependencies
3009 that automatically get installed along with the required package
3010 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
3011 @code{package} objects}, for information about propagated inputs in
3012 package definitions).
3014 @anchor{package-cmd-propagated-inputs}
3015 An example is the GNU MPC library: its C header files refer to those of
3016 the GNU MPFR library, which in turn refer to those of the GMP library.
3017 Thus, when installing MPC, the MPFR and GMP libraries also get installed
3018 in the profile; removing MPC also removes MPFR and GMP---unless they had
3019 also been explicitly installed by the user.
3021 Besides, packages sometimes rely on the definition of environment
3022 variables for their search paths (see explanation of
3023 @option{--search-paths} below). Any missing or possibly incorrect
3024 environment variable definitions are reported here.
3026 @item --install-from-expression=@var{exp}
3028 Install the package @var{exp} evaluates to.
3030 @var{exp} must be a Scheme expression that evaluates to a
3031 @code{<package>} object. This option is notably useful to disambiguate
3032 between same-named variants of a package, with expressions such as
3033 @code{(@@ (gnu packages base) guile-final)}.
3035 Note that this option installs the first output of the specified
3036 package, which may be insufficient when needing a specific output of a
3037 multiple-output package.
3039 @item --install-from-file=@var{file}
3040 @itemx -f @var{file}
3041 Install the package that the code within @var{file} evaluates to.
3043 As an example, @var{file} might contain a definition like this
3044 (@pxref{Defining Packages}):
3047 @include package-hello.scm
3050 Developers may find it useful to include such a @file{guix.scm} file
3051 in the root of their project source tree that can be used to test
3052 development snapshots and create reproducible development environments
3053 (@pxref{Invoking guix environment}).
3055 The @var{file} may also contain a JSON representation of one or more
3056 package definitions. Running @code{guix package -f} on
3057 @file{hello.json} with the following contents would result in installing
3058 the package @code{greeter} after building @code{myhello}:
3061 @verbatiminclude package-hello.json
3064 @item --remove=@var{package} @dots{}
3065 @itemx -r @var{package} @dots{}
3066 Remove the specified @var{package}s.
3068 As for @option{--install}, each @var{package} may specify a version number
3069 and/or output name in addition to the package name. For instance,
3070 @samp{-r glibc:debug} would remove the @code{debug} output of
3073 @item --upgrade[=@var{regexp} @dots{}]
3074 @itemx -u [@var{regexp} @dots{}]
3075 @cindex upgrading packages
3076 Upgrade all the installed packages. If one or more @var{regexp}s are
3077 specified, upgrade only installed packages whose name matches a
3078 @var{regexp}. Also see the @option{--do-not-upgrade} option below.
3080 Note that this upgrades package to the latest version of packages found
3081 in the distribution currently installed. To update your distribution,
3082 you should regularly run @command{guix pull} (@pxref{Invoking guix
3085 @item --do-not-upgrade[=@var{regexp} @dots{}]
3086 When used together with the @option{--upgrade} option, do @emph{not}
3087 upgrade any packages whose name matches a @var{regexp}. For example, to
3088 upgrade all packages in the current profile except those containing the
3089 substring ``emacs'':
3092 $ guix package --upgrade . --do-not-upgrade emacs
3095 @item @anchor{profile-manifest}--manifest=@var{file}
3096 @itemx -m @var{file}
3097 @cindex profile declaration
3098 @cindex profile manifest
3099 Create a new generation of the profile from the manifest object
3100 returned by the Scheme code in @var{file}. This option can be repeated
3101 several times, in which case the manifests are concatenated.
3103 This allows you to @emph{declare} the profile's contents rather than
3104 constructing it through a sequence of @option{--install} and similar
3105 commands. The advantage is that @var{file} can be put under version
3106 control, copied to different machines to reproduce the same profile, and
3109 @c FIXME: Add reference to (guix profile) documentation when available.
3110 @var{file} must return a @dfn{manifest} object, which is roughly a list
3113 @findex packages->manifest
3115 (use-package-modules guile emacs)
3120 ;; Use a specific package output.
3121 (list guile-2.0 "debug")))
3124 @findex specifications->manifest
3125 In this example we have to know which modules define the @code{emacs}
3126 and @code{guile-2.0} variables to provide the right
3127 @code{use-package-modules} line, which can be cumbersome. We can
3128 instead provide regular package specifications and let
3129 @code{specifications->manifest} look up the corresponding package
3133 (specifications->manifest
3134 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
3138 @cindex rolling back
3139 @cindex undoing transactions
3140 @cindex transactions, undoing
3141 Roll back to the previous @dfn{generation} of the profile---i.e., undo
3142 the last transaction.
3144 When combined with options such as @option{--install}, roll back occurs
3145 before any other actions.
3147 When rolling back from the first generation that actually contains
3148 installed packages, the profile is made to point to the @dfn{zeroth
3149 generation}, which contains no files apart from its own metadata.
3151 After having rolled back, installing, removing, or upgrading packages
3152 overwrites previous future generations. Thus, the history of the
3153 generations in a profile is always linear.
3155 @item --switch-generation=@var{pattern}
3156 @itemx -S @var{pattern}
3158 Switch to a particular generation defined by @var{pattern}.
3160 @var{pattern} may be either a generation number or a number prefixed
3161 with ``+'' or ``-''. The latter means: move forward/backward by a
3162 specified number of generations. For example, if you want to return to
3163 the latest generation after @option{--roll-back}, use
3164 @option{--switch-generation=+1}.
3166 The difference between @option{--roll-back} and
3167 @option{--switch-generation=-1} is that @option{--switch-generation} will
3168 not make a zeroth generation, so if a specified generation does not
3169 exist, the current generation will not be changed.
3171 @item --search-paths[=@var{kind}]
3172 @cindex search paths
3173 Report environment variable definitions, in Bash syntax, that may be
3174 needed in order to use the set of installed packages. These environment
3175 variables are used to specify @dfn{search paths} for files used by some
3176 of the installed packages.
3178 For example, GCC needs the @env{CPATH} and @env{LIBRARY_PATH}
3179 environment variables to be defined so it can look for headers and
3180 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
3181 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
3182 library are installed in the profile, then @option{--search-paths} will
3183 suggest setting these variables to @file{@var{profile}/include} and
3184 @file{@var{profile}/lib}, respectively.
3186 The typical use case is to define these environment variables in the
3190 $ eval `guix package --search-paths`
3193 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
3194 meaning that the returned environment variable definitions will either
3195 be exact settings, or prefixes or suffixes of the current value of these
3196 variables. When omitted, @var{kind} defaults to @code{exact}.
3198 This option can also be used to compute the @emph{combined} search paths
3199 of several profiles. Consider this example:
3202 $ guix package -p foo -i guile
3203 $ guix package -p bar -i guile-json
3204 $ guix package -p foo -p bar --search-paths
3207 The last command above reports about the @env{GUILE_LOAD_PATH}
3208 variable, even though, taken individually, neither @file{foo} nor
3209 @file{bar} would lead to that recommendation.
3212 @item --profile=@var{profile}
3213 @itemx -p @var{profile}
3214 Use @var{profile} instead of the user's default profile.
3216 @var{profile} must be the name of a file that will be created upon
3217 completion. Concretely, @var{profile} will be a mere symbolic link
3218 (``symlink'') pointing to the actual profile where packages are
3222 $ guix install hello -p ~/code/my-profile
3224 $ ~/code/my-profile/bin/hello
3228 All it takes to get rid of the profile is to remove this symlink and its
3229 siblings that point to specific generations:
3232 $ rm ~/code/my-profile ~/code/my-profile-*-link
3235 @item --list-profiles
3236 List all the user's profiles:
3239 $ guix package --list-profiles
3240 /home/charlie/.guix-profile
3241 /home/charlie/code/my-profile
3242 /home/charlie/code/devel-profile
3243 /home/charlie/tmp/test
3246 When running as root, list all the profiles of all the users.
3248 @cindex collisions, in a profile
3249 @cindex colliding packages in profiles
3250 @cindex profile collisions
3251 @item --allow-collisions
3252 Allow colliding packages in the new profile. Use at your own risk!
3254 By default, @command{guix package} reports as an error @dfn{collisions}
3255 in the profile. Collisions happen when two or more different versions
3256 or variants of a given package end up in the profile.
3259 Use the bootstrap Guile to build the profile. This option is only
3260 useful to distribution developers.
3264 In addition to these actions, @command{guix package} supports the
3265 following options to query the current state of a profile, or the
3266 availability of packages:
3270 @item --search=@var{regexp}
3271 @itemx -s @var{regexp}
3272 @anchor{guix-search}
3273 @cindex searching for packages
3274 List the available packages whose name, synopsis, or description matches
3275 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
3276 Print all the metadata of matching packages in
3277 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
3278 GNU recutils manual}).
3280 This allows specific fields to be extracted using the @command{recsel}
3281 command, for instance:
3284 $ guix package -s malloc | recsel -p name,version,relevance
3298 Similarly, to show the name of all the packages available under the
3299 terms of the GNU@tie{}LGPL version 3:
3302 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
3309 It is also possible to refine search results using several @code{-s} flags to
3310 @command{guix package}, or several arguments to @command{guix search}. For
3311 example, the following command returns a list of board games (this time using
3312 the @command{guix search} alias):
3315 $ guix search '\<board\>' game | recsel -p name
3320 If we were to omit @code{-s game}, we would also get software packages
3321 that deal with printed circuit boards; removing the angle brackets
3322 around @code{board} would further add packages that have to do with
3325 And now for a more elaborate example. The following command searches
3326 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
3327 libraries, and prints the name and synopsis of the matching packages:
3330 $ guix search crypto library | \
3331 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3335 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3336 information on @dfn{selection expressions} for @code{recsel -e}.
3338 @item --show=@var{package}
3339 Show details about @var{package}, taken from the list of available packages, in
3340 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3344 $ guix package --show=python | recsel -p name,version
3352 You may also specify the full name of a package to only get details about a
3353 specific version of it (this time using the @command{guix show} alias):
3355 $ guix show python@@3.4 | recsel -p name,version
3362 @item --list-installed[=@var{regexp}]
3363 @itemx -I [@var{regexp}]
3364 List the currently installed packages in the specified profile, with the
3365 most recently installed packages shown last. When @var{regexp} is
3366 specified, list only installed packages whose name matches @var{regexp}.
3368 For each installed package, print the following items, separated by
3369 tabs: the package name, its version string, the part of the package that
3370 is installed (for instance, @code{out} for the default output,
3371 @code{include} for its headers, etc.), and the path of this package in
3374 @item --list-available[=@var{regexp}]
3375 @itemx -A [@var{regexp}]
3376 List packages currently available in the distribution for this system
3377 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3378 available packages whose name matches @var{regexp}.
3380 For each package, print the following items separated by tabs: its name,
3381 its version string, the parts of the package (@pxref{Packages with
3382 Multiple Outputs}), and the source location of its definition.
3384 @item --list-generations[=@var{pattern}]
3385 @itemx -l [@var{pattern}]
3387 Return a list of generations along with their creation dates; for each
3388 generation, show the installed packages, with the most recently
3389 installed packages shown last. Note that the zeroth generation is never
3392 For each installed package, print the following items, separated by
3393 tabs: the name of a package, its version string, the part of the package
3394 that is installed (@pxref{Packages with Multiple Outputs}), and the
3395 location of this package in the store.
3397 When @var{pattern} is used, the command returns only matching
3398 generations. Valid patterns include:
3401 @item @emph{Integers and comma-separated integers}. Both patterns denote
3402 generation numbers. For instance, @option{--list-generations=1} returns
3405 And @option{--list-generations=1,8,2} outputs three generations in the
3406 specified order. Neither spaces nor trailing commas are allowed.
3408 @item @emph{Ranges}. @option{--list-generations=2..9} prints the
3409 specified generations and everything in between. Note that the start of
3410 a range must be smaller than its end.
3412 It is also possible to omit the endpoint. For example,
3413 @option{--list-generations=2..}, returns all generations starting from the
3416 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3417 or months by passing an integer along with the first letter of the
3418 duration. For example, @option{--list-generations=20d} lists generations
3419 that are up to 20 days old.
3422 @item --delete-generations[=@var{pattern}]
3423 @itemx -d [@var{pattern}]
3424 When @var{pattern} is omitted, delete all generations except the current
3427 This command accepts the same patterns as @option{--list-generations}.
3428 When @var{pattern} is specified, delete the matching generations. When
3429 @var{pattern} specifies a duration, generations @emph{older} than the
3430 specified duration match. For instance, @option{--delete-generations=1m}
3431 deletes generations that are more than one month old.
3433 If the current generation matches, it is @emph{not} deleted. Also, the
3434 zeroth generation is never deleted.
3436 Note that deleting generations prevents rolling back to them.
3437 Consequently, this command must be used with care.
3441 Finally, since @command{guix package} may actually start build
3442 processes, it supports all the common build options (@pxref{Common Build
3443 Options}). It also supports package transformation options, such as
3444 @option{--with-source} (@pxref{Package Transformation Options}).
3445 However, note that package transformations are lost when upgrading; to
3446 preserve transformations across upgrades, you should define your own
3447 package variant in a Guile module and add it to @env{GUIX_PACKAGE_PATH}
3448 (@pxref{Defining Packages}).
3451 @section Substitutes
3454 @cindex pre-built binaries
3455 Guix supports transparent source/binary deployment, which means that it
3456 can either build things locally, or download pre-built items from a
3457 server, or both. We call these pre-built items @dfn{substitutes}---they
3458 are substitutes for local build results. In many cases, downloading a
3459 substitute is much faster than building things locally.
3461 Substitutes can be anything resulting from a derivation build
3462 (@pxref{Derivations}). Of course, in the common case, they are
3463 pre-built package binaries, but source tarballs, for instance, which
3464 also result from derivation builds, can be available as substitutes.
3467 * Official Substitute Server:: One particular source of substitutes.
3468 * Substitute Server Authorization:: How to enable or disable substitutes.
3469 * Substitute Authentication:: How Guix verifies substitutes.
3470 * Proxy Settings:: How to get substitutes via proxy.
3471 * Substitution Failure:: What happens when substitution fails.
3472 * On Trusting Binaries:: How can you trust that binary blob?
3475 @node Official Substitute Server
3476 @subsection Official Substitute Server
3479 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3480 that builds packages from Guix continuously for some
3481 architectures, and makes them available as substitutes. This is the
3482 default source of substitutes; it can be overridden by passing the
3483 @option{--substitute-urls} option either to @command{guix-daemon}
3484 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3485 or to client tools such as @command{guix package}
3486 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3489 Substitute URLs can be either HTTP or HTTPS.
3490 HTTPS is recommended because communications are encrypted; conversely,
3491 using HTTP makes all communications visible to an eavesdropper, who
3492 could use the information gathered to determine, for instance, whether
3493 your system has unpatched security vulnerabilities.
3495 Substitutes from the official build farm are enabled by default when
3496 using Guix System (@pxref{GNU Distribution}). However,
3497 they are disabled by default when using Guix on a foreign distribution,
3498 unless you have explicitly enabled them via one of the recommended
3499 installation steps (@pxref{Installation}). The following paragraphs
3500 describe how to enable or disable substitutes for the official build
3501 farm; the same procedure can also be used to enable substitutes for any
3502 other substitute server.
3504 @node Substitute Server Authorization
3505 @subsection Substitute Server Authorization
3508 @cindex substitutes, authorization thereof
3509 @cindex access control list (ACL), for substitutes
3510 @cindex ACL (access control list), for substitutes
3511 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3513 must add its public key to the access control list (ACL) of archive
3514 imports, using the @command{guix archive} command (@pxref{Invoking guix
3515 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3516 be compromised and to serve genuine substitutes.
3518 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3519 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3520 the installation prefix of Guix. If you installed Guix from source,
3521 make sure you checked the GPG signature of
3522 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3523 Then, you can run something like this:
3526 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3529 Once this is in place, the output of a command like @code{guix build}
3530 should change from something like:
3533 $ guix build emacs --dry-run
3534 The following derivations would be built:
3535 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3536 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3537 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3538 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3546 $ guix build emacs --dry-run
3547 112.3 MB would be downloaded:
3548 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3549 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3550 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3551 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3556 The text changed from ``The following derivations would be built'' to
3557 ``112.3 MB would be downloaded''. This indicates that substitutes from
3558 @code{@value{SUBSTITUTE-SERVER}} are usable and will be downloaded, when
3559 possible, for future builds.
3561 @cindex substitutes, how to disable
3562 The substitute mechanism can be disabled globally by running
3563 @code{guix-daemon} with @option{--no-substitutes} (@pxref{Invoking
3564 guix-daemon}). It can also be disabled temporarily by passing the
3565 @option{--no-substitutes} option to @command{guix package},
3566 @command{guix build}, and other command-line tools.
3568 @node Substitute Authentication
3569 @subsection Substitute Authentication
3571 @cindex digital signatures
3572 Guix detects and raises an error when attempting to use a substitute
3573 that has been tampered with. Likewise, it ignores substitutes that are
3574 not signed, or that are not signed by one of the keys listed in the ACL.
3576 There is one exception though: if an unauthorized server provides
3577 substitutes that are @emph{bit-for-bit identical} to those provided by
3578 an authorized server, then the unauthorized server becomes eligible for
3579 downloads. For example, assume we have chosen two substitute servers
3583 --substitute-urls="https://a.example.org https://b.example.org"
3587 @cindex reproducible builds
3588 If the ACL contains only the key for @samp{b.example.org}, and if
3589 @samp{a.example.org} happens to serve the @emph{exact same} substitutes,
3590 then Guix will download substitutes from @samp{a.example.org} because it
3591 comes first in the list and can be considered a mirror of
3592 @samp{b.example.org}. In practice, independent build machines usually
3593 produce the same binaries, thanks to bit-reproducible builds (see
3596 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3597 (in other words, the server is not authenticated), contrary to what
3598 HTTPS clients such as Web browsers usually do. This is because Guix
3599 authenticates substitute information itself, as explained above, which
3600 is what we care about (whereas X.509 certificates are about
3601 authenticating bindings between domain names and public keys).
3603 @node Proxy Settings
3604 @subsection Proxy Settings
3608 Substitutes are downloaded over HTTP or HTTPS. The @env{http_proxy} and
3609 @env{https_proxy} environment variables can be set in the environment of
3610 @command{guix-daemon} and are honored for downloads of substitutes.
3611 Note that the value of those environment variables in the environment
3612 where @command{guix build}, @command{guix package}, and other client
3613 commands are run has @emph{absolutely no effect}.
3615 @node Substitution Failure
3616 @subsection Substitution Failure
3618 Even when a substitute for a derivation is available, sometimes the
3619 substitution attempt will fail. This can happen for a variety of
3620 reasons: the substitute server might be offline, the substitute may
3621 recently have been deleted, the connection might have been interrupted,
3624 When substitutes are enabled and a substitute for a derivation is
3625 available, but the substitution attempt fails, Guix will attempt to
3626 build the derivation locally depending on whether or not
3627 @option{--fallback} was given (@pxref{fallback-option,, common build
3628 option @option{--fallback}}). Specifically, if @option{--fallback} was
3629 omitted, then no local build will be performed, and the derivation is
3630 considered to have failed. However, if @option{--fallback} was given,
3631 then Guix will attempt to build the derivation locally, and the success
3632 or failure of the derivation depends on the success or failure of the
3633 local build. Note that when substitutes are disabled or no substitute
3634 is available for the derivation in question, a local build will
3635 @emph{always} be performed, regardless of whether or not
3636 @option{--fallback} was given.
3638 To get an idea of how many substitutes are available right now, you can
3639 try running the @command{guix weather} command (@pxref{Invoking guix
3640 weather}). This command provides statistics on the substitutes provided
3643 @node On Trusting Binaries
3644 @subsection On Trusting Binaries
3646 @cindex trust, of pre-built binaries
3647 Today, each individual's control over their own computing is at the
3648 mercy of institutions, corporations, and groups with enough power and
3649 determination to subvert the computing infrastructure and exploit its
3650 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3651 convenient, we encourage users to also build on their own, or even run
3652 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3653 interesting target. One way to help is by publishing the software you
3654 build using @command{guix publish} so that others have one more choice
3655 of server to download substitutes from (@pxref{Invoking guix publish}).
3657 Guix has the foundations to maximize build reproducibility
3658 (@pxref{Features}). In most cases, independent builds of a given
3659 package or derivation should yield bit-identical results. Thus, through
3660 a diverse set of independent package builds, we can strengthen the
3661 integrity of our systems. The @command{guix challenge} command aims to
3662 help users assess substitute servers, and to assist developers in
3663 finding out about non-deterministic package builds (@pxref{Invoking guix
3664 challenge}). Similarly, the @option{--check} option of @command{guix
3665 build} allows users to check whether previously-installed substitutes
3666 are genuine by rebuilding them locally (@pxref{build-check,
3667 @command{guix build --check}}).
3669 In the future, we want Guix to have support to publish and retrieve
3670 binaries to/from other users, in a peer-to-peer fashion. If you would
3671 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3673 @node Packages with Multiple Outputs
3674 @section Packages with Multiple Outputs
3676 @cindex multiple-output packages
3677 @cindex package outputs
3680 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3681 source package leads to exactly one directory in the store. When running
3682 @command{guix install glibc}, one installs the default output of the
3683 GNU libc package; the default output is called @code{out}, but its name
3684 can be omitted as shown in this command. In this particular case, the
3685 default output of @code{glibc} contains all the C header files, shared
3686 libraries, static libraries, Info documentation, and other supporting
3689 Sometimes it is more appropriate to separate the various types of files
3690 produced from a single source package into separate outputs. For
3691 instance, the GLib C library (used by GTK+ and related packages)
3692 installs more than 20 MiB of reference documentation as HTML pages.
3693 To save space for users who do not need it, the documentation goes to a
3694 separate output, called @code{doc}. To install the main GLib output,
3695 which contains everything but the documentation, one would run:
3701 @cindex documentation
3702 The command to install its documentation is:
3705 guix install glib:doc
3708 Some packages install programs with different ``dependency footprints''.
3709 For instance, the WordNet package installs both command-line tools and
3710 graphical user interfaces (GUIs). The former depend solely on the C
3711 library, whereas the latter depend on Tcl/Tk and the underlying X
3712 libraries. In this case, we leave the command-line tools in the default
3713 output, whereas the GUIs are in a separate output. This allows users
3714 who do not need the GUIs to save space. The @command{guix size} command
3715 can help find out about such situations (@pxref{Invoking guix size}).
3716 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3718 There are several such multiple-output packages in the GNU distribution.
3719 Other conventional output names include @code{lib} for libraries and
3720 possibly header files, @code{bin} for stand-alone programs, and
3721 @code{debug} for debugging information (@pxref{Installing Debugging
3722 Files}). The outputs of a packages are listed in the third column of
3723 the output of @command{guix package --list-available} (@pxref{Invoking
3727 @node Invoking guix gc
3728 @section Invoking @command{guix gc}
3730 @cindex garbage collector
3732 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3733 The @command{guix gc} command allows users to explicitly run the garbage
3734 collector to reclaim space from the @file{/gnu/store} directory. It is
3735 the @emph{only} way to remove files from @file{/gnu/store}---removing
3736 files or directories manually may break it beyond repair!
3739 @cindex garbage collector roots
3740 The garbage collector has a set of known @dfn{roots}: any file under
3741 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3742 cannot be deleted; any other file is considered @dfn{dead} and may be
3743 deleted. The set of garbage collector roots (``GC roots'' for short)
3744 includes default user profiles; by default, the symlinks under
3745 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3746 added with @command{guix build --root}, for example (@pxref{Invoking
3747 guix build}). The @command{guix gc --list-roots} command lists them.
3749 Prior to running @code{guix gc --collect-garbage} to make space, it is
3750 often useful to remove old generations from user profiles; that way, old
3751 package builds referenced by those generations can be reclaimed. This
3752 is achieved by running @code{guix package --delete-generations}
3753 (@pxref{Invoking guix package}).
3755 Our recommendation is to run a garbage collection periodically, or when
3756 you are short on disk space. For instance, to guarantee that at least
3757 5@tie{}GB are available on your disk, simply run:
3763 It is perfectly safe to run as a non-interactive periodic job
3764 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3765 Running @command{guix gc} with no arguments will collect as
3766 much garbage as it can, but that is often inconvenient: you may find
3767 yourself having to rebuild or re-download software that is ``dead'' from
3768 the GC viewpoint but that is necessary to build other pieces of
3769 software---e.g., the compiler tool chain.
3771 The @command{guix gc} command has three modes of operation: it can be
3772 used to garbage-collect any dead files (the default), to delete specific
3773 files (the @option{--delete} option), to print garbage-collector
3774 information, or for more advanced queries. The garbage collection
3775 options are as follows:
3778 @item --collect-garbage[=@var{min}]
3779 @itemx -C [@var{min}]
3780 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3781 sub-directories. This is the default operation when no option is
3784 When @var{min} is given, stop once @var{min} bytes have been collected.
3785 @var{min} may be a number of bytes, or it may include a unit as a
3786 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3787 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3789 When @var{min} is omitted, collect all the garbage.
3791 @item --free-space=@var{free}
3792 @itemx -F @var{free}
3793 Collect garbage until @var{free} space is available under
3794 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3795 as @code{500MiB}, as described above.
3797 When @var{free} or more is already available in @file{/gnu/store}, do
3798 nothing and exit immediately.
3800 @item --delete-generations[=@var{duration}]
3801 @itemx -d [@var{duration}]
3802 Before starting the garbage collection process, delete all the generations
3803 older than @var{duration}, for all the user profiles; when run as root, this
3804 applies to all the profiles @emph{of all the users}.
3806 For example, this command deletes all the generations of all your profiles
3807 that are older than 2 months (except generations that are current), and then
3808 proceeds to free space until at least 10 GiB are available:
3811 guix gc -d 2m -F 10G
3816 Attempt to delete all the store files and directories specified as
3817 arguments. This fails if some of the files are not in the store, or if
3818 they are still live.
3820 @item --list-failures
3821 List store items corresponding to cached build failures.
3823 This prints nothing unless the daemon was started with
3824 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3825 @option{--cache-failures}}).
3828 List the GC roots owned by the user; when run as root, list @emph{all} the GC
3832 List store items in use by currently running processes. These store
3833 items are effectively considered GC roots: they cannot be deleted.
3835 @item --clear-failures
3836 Remove the specified store items from the failed-build cache.
3838 Again, this option only makes sense when the daemon is started with
3839 @option{--cache-failures}. Otherwise, it does nothing.
3842 Show the list of dead files and directories still present in the
3843 store---i.e., files and directories no longer reachable from any root.
3846 Show the list of live store files and directories.
3850 In addition, the references among existing store files can be queried:
3856 @cindex package dependencies
3857 List the references (respectively, the referrers) of store files given
3863 List the requisites of the store files passed as arguments. Requisites
3864 include the store files themselves, their references, and the references
3865 of these, recursively. In other words, the returned list is the
3866 @dfn{transitive closure} of the store files.
3868 @xref{Invoking guix size}, for a tool to profile the size of the closure
3869 of an element. @xref{Invoking guix graph}, for a tool to visualize
3870 the graph of references.
3874 Return the derivation(s) leading to the given store items
3875 (@pxref{Derivations}).
3877 For example, this command:
3880 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3884 returns the @file{.drv} file(s) leading to the @code{emacs} package
3885 installed in your profile.
3887 Note that there may be zero matching @file{.drv} files, for instance
3888 because these files have been garbage-collected. There can also be more
3889 than one matching @file{.drv} due to fixed-output derivations.
3892 Lastly, the following options allow you to check the integrity of the
3893 store and to control disk usage.
3897 @item --verify[=@var{options}]
3898 @cindex integrity, of the store
3899 @cindex integrity checking
3900 Verify the integrity of the store.
3902 By default, make sure that all the store items marked as valid in the
3903 database of the daemon actually exist in @file{/gnu/store}.
3905 When provided, @var{options} must be a comma-separated list containing one
3906 or more of @code{contents} and @code{repair}.
3908 When passing @option{--verify=contents}, the daemon computes the
3909 content hash of each store item and compares it against its hash in the
3910 database. Hash mismatches are reported as data corruptions. Because it
3911 traverses @emph{all the files in the store}, this command can take a
3912 long time, especially on systems with a slow disk drive.
3914 @cindex repairing the store
3915 @cindex corruption, recovering from
3916 Using @option{--verify=repair} or @option{--verify=contents,repair}
3917 causes the daemon to try to repair corrupt store items by fetching
3918 substitutes for them (@pxref{Substitutes}). Because repairing is not
3919 atomic, and thus potentially dangerous, it is available only to the
3920 system administrator. A lightweight alternative, when you know exactly
3921 which items in the store are corrupt, is @command{guix build --repair}
3922 (@pxref{Invoking guix build}).
3925 @cindex deduplication
3926 Optimize the store by hard-linking identical files---this is
3927 @dfn{deduplication}.
3929 The daemon performs deduplication after each successful build or archive
3930 import, unless it was started with @option{--disable-deduplication}
3931 (@pxref{Invoking guix-daemon, @option{--disable-deduplication}}). Thus,
3932 this option is primarily useful when the daemon was running with
3933 @option{--disable-deduplication}.
3937 @node Invoking guix pull
3938 @section Invoking @command{guix pull}
3940 @cindex upgrading Guix
3941 @cindex updating Guix
3942 @cindex @command{guix pull}
3944 @cindex security, @command{guix pull}
3945 @cindex authenticity, of code obtained with @command{guix pull}
3946 Packages are installed or upgraded to the latest version available in
3947 the distribution currently available on your local machine. To update
3948 that distribution, along with the Guix tools, you must run @command{guix
3949 pull}: the command downloads the latest Guix source code and package
3950 descriptions, and deploys it. Source code is downloaded from a
3951 @uref{https://git-scm.com, Git} repository, by default the official
3952 GNU@tie{}Guix repository, though this can be customized. @command{guix
3953 pull} ensures that the code it downloads is @emph{authentic} by
3954 verifying that commits are signed by Guix developers.
3956 Specifically, @command{guix pull} downloads code from the @dfn{channels}
3957 (@pxref{Channels}) specified by one of the followings, in this order:
3961 the @option{--channels} option;
3963 the user's @file{~/.config/guix/channels.scm} file;
3965 the system-wide @file{/etc/guix/channels.scm} file;
3967 the built-in default channels specified in the @code{%default-channels}
3971 On completion, @command{guix package} will use packages and package
3972 versions from this just-retrieved copy of Guix. Not only that, but all
3973 the Guix commands and Scheme modules will also be taken from that latest
3974 version. New @command{guix} sub-commands added by the update also
3977 Any user can update their Guix copy using @command{guix pull}, and the
3978 effect is limited to the user who ran @command{guix pull}. For
3979 instance, when user @code{root} runs @command{guix pull}, this has no
3980 effect on the version of Guix that user @code{alice} sees, and vice
3983 The result of running @command{guix pull} is a @dfn{profile} available
3984 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3985 make sure to add it to the beginning of your search path so that you use
3986 the latest version, and similarly for the Info manual
3987 (@pxref{Documentation}):
3990 export PATH="$HOME/.config/guix/current/bin:$PATH"
3991 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3994 The @option{--list-generations} or @option{-l} option lists past generations
3995 produced by @command{guix pull}, along with details about their provenance:
3999 Generation 1 Jun 10 2018 00:18:18
4001 repository URL: https://git.savannah.gnu.org/git/guix.git
4002 branch: origin/master
4003 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
4005 Generation 2 Jun 11 2018 11:02:49
4007 repository URL: https://git.savannah.gnu.org/git/guix.git
4008 branch: origin/master
4009 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
4010 2 new packages: keepalived, libnfnetlink
4011 6 packages upgraded: emacs-nix-mode@@2.0.4,
4012 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
4013 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
4015 Generation 3 Jun 13 2018 23:31:07 (current)
4017 repository URL: https://git.savannah.gnu.org/git/guix.git
4018 branch: origin/master
4019 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
4020 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
4021 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
4024 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
4025 describe the current status of Guix.
4027 This @code{~/.config/guix/current} profile works exactly like the profiles
4028 created by @command{guix package} (@pxref{Invoking guix package}). That
4029 is, you can list generations, roll back to the previous
4030 generation---i.e., the previous Guix---and so on:
4033 $ guix pull --roll-back
4034 switched from generation 3 to 2
4035 $ guix pull --delete-generations=1
4036 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
4039 You can also use @command{guix package} (@pxref{Invoking guix package})
4040 to manage the profile by naming it explicitly:
4042 $ guix package -p ~/.config/guix/current --roll-back
4043 switched from generation 3 to 2
4044 $ guix package -p ~/.config/guix/current --delete-generations=1
4045 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
4048 The @command{guix pull} command is usually invoked with no arguments,
4049 but it supports the following options:
4052 @item --url=@var{url}
4053 @itemx --commit=@var{commit}
4054 @itemx --branch=@var{branch}
4055 Download code for the @code{guix} channel from the specified @var{url}, at the
4056 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4057 string), or @var{branch}.
4059 @cindex @file{channels.scm}, configuration file
4060 @cindex configuration file for channels
4061 These options are provided for convenience, but you can also specify your
4062 configuration in the @file{~/.config/guix/channels.scm} file or using the
4063 @option{--channels} option (see below).
4065 @item --channels=@var{file}
4066 @itemx -C @var{file}
4067 Read the list of channels from @var{file} instead of
4068 @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
4069 @var{file} must contain Scheme code that
4070 evaluates to a list of channel objects. @xref{Channels}, for more
4073 @cindex channel news
4076 Display the list of packages added or upgraded since the previous
4077 generation, as well as, occasionally, news written by channel authors
4078 for their users (@pxref{Channels, Writing Channel News}).
4080 The package information is the same as displayed upon @command{guix
4081 pull} completion, but without ellipses; it is also similar to the output
4082 of @command{guix pull -l} for the last generation (see below).
4084 @item --list-generations[=@var{pattern}]
4085 @itemx -l [@var{pattern}]
4086 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
4087 is provided, the subset of generations that match @var{pattern}.
4088 The syntax of @var{pattern} is the same as with @code{guix package
4089 --list-generations} (@pxref{Invoking guix package}).
4092 @cindex rolling back
4093 @cindex undoing transactions
4094 @cindex transactions, undoing
4095 Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
4096 undo the last transaction.
4098 @item --switch-generation=@var{pattern}
4099 @itemx -S @var{pattern}
4101 Switch to a particular generation defined by @var{pattern}.
4103 @var{pattern} may be either a generation number or a number prefixed
4104 with ``+'' or ``-''. The latter means: move forward/backward by a
4105 specified number of generations. For example, if you want to return to
4106 the latest generation after @option{--roll-back}, use
4107 @option{--switch-generation=+1}.
4109 @item --delete-generations[=@var{pattern}]
4110 @itemx -d [@var{pattern}]
4111 When @var{pattern} is omitted, delete all generations except the current
4114 This command accepts the same patterns as @option{--list-generations}.
4115 When @var{pattern} is specified, delete the matching generations. When
4116 @var{pattern} specifies a duration, generations @emph{older} than the
4117 specified duration match. For instance, @option{--delete-generations=1m}
4118 deletes generations that are more than one month old.
4120 If the current generation matches, it is @emph{not} deleted.
4122 Note that deleting generations prevents rolling back to them.
4123 Consequently, this command must be used with care.
4125 @xref{Invoking guix describe}, for a way to display information about the
4126 current generation only.
4128 @item --profile=@var{profile}
4129 @itemx -p @var{profile}
4130 Use @var{profile} instead of @file{~/.config/guix/current}.
4134 Show which channel commit(s) would be used and what would be built or
4135 substituted but do not actually do it.
4137 @item --allow-downgrades
4138 Allow pulling older or unrelated revisions of channels than those
4141 @cindex downgrade attacks, protection against
4142 By default, @command{guix pull} protects against so-called ``downgrade
4143 attacks'' whereby the Git repository of a channel would be reset to an
4144 earlier or unrelated revision of itself, potentially leading you to
4145 install older, known-vulnerable versions of software packages.
4148 Make sure you understand its security implications before using
4149 @option{--allow-downgrades}.
4152 @item --disable-authentication
4153 Allow pulling channel code without authenticating it.
4155 @cindex authentication, of channel code
4156 By default, @command{guix pull} authenticates code downloaded from
4157 channels by verifying that its commits are signed by authorized
4158 developers, and raises an error if this is not the case. This option
4159 instructs it to not perform any such verification.
4162 Make sure you understand its security implications before using
4163 @option{--disable-authentication}.
4166 @item --system=@var{system}
4167 @itemx -s @var{system}
4168 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
4169 the system type of the build host.
4172 Use the bootstrap Guile to build the latest Guix. This option is only
4173 useful to Guix developers.
4176 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
4177 repository and branch to pull from, as well as @emph{additional} repositories
4178 containing package modules that should be deployed. @xref{Channels}, for more
4181 In addition, @command{guix pull} supports all the common build options
4182 (@pxref{Common Build Options}).
4188 @cindex @file{channels.scm}, configuration file
4189 @cindex configuration file for channels
4190 @cindex @command{guix pull}, configuration file
4191 @cindex configuration of @command{guix pull}
4192 Guix and its package collection are updated by running @command{guix pull}
4193 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
4194 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
4195 customized by defining @dfn{channels} in the
4196 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
4197 of a Git repository to be deployed, and @command{guix pull} can be instructed
4198 to pull from one or more channels. In other words, channels can be used
4199 to @emph{customize} and to @emph{extend} Guix, as we will see below.
4200 Before that, some security considerations.
4202 @subsection Channel Authentication
4204 @anchor{channel-authentication}
4205 @cindex authentication, of channel code
4206 The @command{guix pull} and @command{guix time-machine} commands
4207 @dfn{authenticate} the code retrieved from channels: they make sure each
4208 commit that is fetched is signed by an authorized developer. The goal
4209 is to protect from unauthorized modifications to the channel that would
4210 lead users to run malicious code.
4212 As a user, you must provide a @dfn{channel introduction} in your
4213 channels file so that Guix knows how to authenticate its first commit.
4214 A channel specification, including its introduction, looks something
4220 (url "https://example.org/my-channel.git")
4222 (make-channel-introduction
4223 "6f0d8cc0d88abb59c324b2990bfee2876016bb86"
4224 (openpgp-fingerprint
4225 "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
4228 The specification above shows the name and URL of the channel. The call
4229 to @code{make-channel-introduction} above specifies that authentication
4230 of this channel starts at commit @code{6f0d8cc@dots{}}, which is signed
4231 by the OpenPGP key with fingerprint @code{CABB A931@dots{}}.
4233 For the main channel, called @code{guix}, you automatically get that
4234 information from your Guix installation. For other channels, include
4235 the channel introduction provided by the channel authors in your
4236 @file{channels.scm} file. Make sure you retrieve the channel
4237 introduction from a trusted source since that is the root of your trust.
4239 If you're curious about the authentication mechanics, read on!
4241 @subsection Using a Custom Guix Channel
4243 The channel called @code{guix} specifies where Guix itself---its command-line
4244 tools as well as its package collection---should be downloaded. For instance,
4245 suppose you want to update from your own copy of the Guix repository at
4246 @code{example.org}, and specifically the @code{super-hacks} branch, you can
4247 write in @code{~/.config/guix/channels.scm} this specification:
4250 ;; Tell 'guix pull' to use my own repo.
4253 (url "https://example.org/my-guix.git")
4254 (branch "super-hacks")))
4258 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
4259 branch of the repository at @code{example.org}.
4261 @subsection Specifying Additional Channels
4263 @cindex extending the package collection (channels)
4264 @cindex personal packages (channels)
4265 @cindex channels, for personal packages
4266 You can also specify @emph{additional channels} to pull from. Let's say you
4267 have a bunch of custom package variants or personal packages that you think
4268 would make little sense to contribute to the Guix project, but would like to
4269 have these packages transparently available to you at the command line. You
4270 would first write modules containing those package definitions (@pxref{Package
4271 Modules}), maintain them in a Git repository, and then you and anyone else can
4272 use it as an additional channel to get packages from. Neat, no?
4274 @c What follows stems from discussions at
4275 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
4276 @c earlier discussions on guix-devel@gnu.org.
4278 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
4279 publish your personal channel to the world, we would like to share a few words
4284 Before publishing a channel, please consider contributing your package
4285 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
4286 to free software of all sorts, and packages in Guix proper are readily
4287 available to all Guix users and benefit from the project's quality assurance
4291 When you maintain package definitions outside Guix, we, Guix developers,
4292 consider that @emph{the compatibility burden is on you}. Remember that
4293 package modules and package definitions are just Scheme code that uses various
4294 programming interfaces (APIs). We want to remain free to change these APIs to
4295 keep improving Guix, possibly in ways that break your channel. We never
4296 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
4300 Corollary: if you're using an external channel and that channel breaks, please
4301 @emph{report the issue to the channel authors}, not to the Guix project.
4304 You've been warned! Having said this, we believe external channels are a
4305 practical way to exert your freedom to augment Guix' package collection and to
4306 share your improvements, which are basic tenets of
4307 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
4308 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
4311 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
4312 @command{guix pull} to pull from it @emph{in addition} to the default Guix
4315 @vindex %default-channels
4317 ;; Add my personal packages to those Guix provides.
4319 (name 'my-personal-packages)
4320 (url "https://example.org/personal-packages.git"))
4325 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
4326 add a channel the list of channels that the variable @code{%default-channels}
4327 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
4328 Manual}). With this file in place, @command{guix pull} builds not only Guix
4329 but also the package modules from your own repository. The result in
4330 @file{~/.config/guix/current} is the union of Guix with your own package
4334 $ guix pull --list-generations
4336 Generation 19 Aug 27 2018 16:20:48
4338 repository URL: https://git.savannah.gnu.org/git/guix.git
4340 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
4341 my-personal-packages dd3df5e
4342 repository URL: https://example.org/personal-packages.git
4344 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
4345 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
4346 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
4350 The output of @command{guix pull} above shows that Generation@tie{}19 includes
4351 both Guix and packages from the @code{my-personal-packages} channel. Among
4352 the new and upgraded packages that are listed, some like @code{my-gimp} and
4353 @code{my-emacs-with-cool-features} might come from
4354 @code{my-personal-packages}, while others come from the Guix default channel.
4356 To create a channel, create a Git repository containing your own package
4357 modules and make it available. The repository can contain anything, but a
4358 useful channel will contain Guile modules that export packages. Once you
4359 start using a channel, Guix will behave as if the root directory of that
4360 channel's Git repository has been added to the Guile load path (@pxref{Load
4361 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
4362 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
4363 module, then the module will be available under the name @code{(my-packages
4364 my-tools)}, and you will be able to use it like any other module
4365 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
4367 @cindex dependencies, channels
4368 @cindex meta-data, channels
4369 @subsection Declaring Channel Dependencies
4371 Channel authors may decide to augment a package collection provided by other
4372 channels. They can declare their channel to be dependent on other channels in
4373 a meta-data file @file{.guix-channel}, which is to be placed in the root of
4374 the channel repository.
4376 The meta-data file should contain a simple S-expression like this:
4383 (name some-collection)
4384 (url "https://example.org/first-collection.git")
4386 ;; The 'introduction' bit below is optional: you would
4387 ;; provide it for dependencies that can be authenticated.
4389 (channel-introduction
4391 (commit "a8883b58dc82e167c96506cf05095f37c2c2c6cd")
4392 (signer "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
4394 (name some-other-collection)
4395 (url "https://example.org/second-collection.git")
4396 (branch "testing"))))
4399 In the above example this channel is declared to depend on two other channels,
4400 which will both be fetched automatically. The modules provided by the channel
4401 will be compiled in an environment where the modules of all these declared
4402 channels are available.
4404 For the sake of reliability and maintainability, you should avoid dependencies
4405 on channels that you don't control, and you should aim to keep the number of
4406 dependencies to a minimum.
4408 @cindex subdirectory, channels
4409 @subsection Package Modules in a Sub-directory
4411 As a channel author, you may want to keep your channel modules in a
4412 sub-directory. If your modules are in the sub-directory @file{guix}, you must
4413 add a meta-data file @file{.guix-channel} that contains:
4421 @cindex channel authorizations
4422 @subsection Specifying Channel Authorizations
4424 @anchor{channel-authorizations}
4425 As we saw above, Guix ensures the source code it pulls from channels
4426 comes from authorized developers. As a channel author, you need to
4427 specify the list of authorized developers in the
4428 @file{.guix-authorizations} file in the channel's Git repository. The
4429 authentication rule is simple: each commit must be signed by a key
4430 listed in the @file{.guix-authorizations} file of its parent
4431 commit(s)@footnote{Git commits form a @dfn{directed acyclic graph}
4432 (DAG). Each commit can have zero or more parents; ``regular'' commits
4433 have one parent and merge commits have two parent commits. Read
4434 @uref{https://eagain.net/articles/git-for-computer-scientists/, @i{Git
4435 for Computer Scientists}} for a great overview.} The
4436 @file{.guix-authorizations} file looks like this:
4439 ;; Example '.guix-authorizations' file.
4442 (version 0) ;current file format version
4444 (("AD17 A21E F8AE D8F1 CC02 DBD9 F8AE D8F1 765C 61E3"
4446 ("2A39 3FFF 68F4 EF7A 3D29 12AF 68F4 EF7A 22FB B2D5"
4448 ("CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"
4452 Each fingerprint is followed by optional key/value pairs, as in the
4453 example above. Currently these key/value pairs are ignored.
4455 This authentication rule creates a chicken-and-egg issue: how do we
4456 authenticate the first commit? Related to that: how do we deal with
4457 channels whose repository history contains unsigned commits and lack
4458 @file{.guix-authorizations}? And how do we fork existing channels?
4460 @cindex channel introduction
4461 Channel introductions answer these questions by describing the first
4462 commit of a channel that should be authenticated. The first time a
4463 channel is fetched with @command{guix pull} or @command{guix
4464 time-machine}, the command looks up the introductory commit and verifies
4465 that it is signed by the specified OpenPGP key. From then on, it
4466 authenticates commits according to the rule above.
4468 Additionally, your channel must provide all the OpenPGP keys that were
4469 ever mentioned in @file{.guix-authorizations}, stored as @file{.key}
4470 files, which can be either binary or ``ASCII-armored''. By default,
4471 those @file{.key} files are searched for in the branch named
4472 @code{keyring} but you can specify a different branch name in
4473 @code{.guix-channel} like so:
4478 (keyring-reference "my-keyring-branch"))
4481 To summarize, as the author of a channel, there are three things you have
4482 to do to allow users to authenticate your code:
4486 Export the OpenPGP keys of past and present committers with @command{gpg
4487 --export} and store them in @file{.key} files, by default in a branch
4488 named @code{keyring} (we recommend making it an @dfn{orphan branch}).
4491 Introduce an initial @file{.guix-authorizations} in the channel's
4492 repository. Do that in a signed commit (@pxref{Commit Access}, for
4493 information on how to sign Git commits.)
4496 Advertise the channel introduction, for instance on your channel's web
4497 page. The channel introduction, as we saw above, is the commit/key
4498 pair---i.e., the commit that introduced @file{.guix-authorizations}, and
4499 the fingerprint of the OpenPGP used to sign it.
4502 Before pushing to your public Git repository, you can run @command{guix
4503 git-authenticate} to verify that you did sign all the commits you are
4504 about to push with an authorized key:
4507 guix git authenticate @var{commit} @var{signer}
4511 where @var{commit} and @var{signer} are your channel introduction.
4512 @xref{Invoking guix git authenticate}, for details.
4514 Publishing a signed channel requires discipline: any mistake, such as an
4515 unsigned commit or a commit signed by an unauthorized key, will prevent
4516 users from pulling from your channel---well, that's the whole point of
4517 authentication! Pay attention to merges in particular: merge commits
4518 are considered authentic if and only if they are signed by a key present
4519 in the @file{.guix-authorizations} file of @emph{both} branches.
4521 @cindex primary URL, channels
4522 @subsection Primary URL
4524 Channel authors can indicate the primary URL of their channel's Git
4525 repository in the @file{.guix-channel} file, like so:
4530 (url "https://example.org/guix.git"))
4533 This allows @command{guix pull} to determine whether it is pulling code
4534 from a mirror of the channel; when that is the case, it warns the user
4535 that the mirror might be stale and displays the primary URL. That way,
4536 users cannot be tricked into fetching code from a stale mirror that does
4537 not receive security updates.
4539 This feature only makes sense for authenticated repositories, such as
4540 the official @code{guix} channel, for which @command{guix pull} ensures
4541 the code it fetches is authentic.
4543 @cindex news, for channels
4544 @subsection Writing Channel News
4546 Channel authors may occasionally want to communicate to their users
4547 information about important changes in the channel. You'd send them all
4548 an email, but that's not convenient.
4550 Instead, channels can provide a @dfn{news file}; when the channel users
4551 run @command{guix pull}, that news file is automatically read and
4552 @command{guix pull --news} can display the announcements that correspond
4553 to the new commits that have been pulled, if any.
4555 To do that, channel authors must first declare the name of the news file
4556 in their @file{.guix-channel} file:
4561 (news-file "etc/news.txt"))
4564 The news file itself, @file{etc/news.txt} in this example, must look
4565 something like this:
4570 (entry (tag "the-bug-fix")
4571 (title (en "Fixed terrible bug")
4573 (body (en "@@emph@{Good news@}! It's fixed!")
4574 (eo "Certe ĝi pli bone funkcias nun!")))
4575 (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
4576 (title (en "Added a great package")
4577 (ca "Què vol dir guix?"))
4578 (body (en "Don't miss the @@code@{hello@} package!"))))
4581 While the news file is using the Scheme syntax, avoid naming it with a
4582 @file{.scm} extension or else it will get picked up when building the
4583 channel and yield an error since it is not a valid module.
4584 Alternatively, you can move the channel module to a subdirectory and
4585 store the news file in another directory.
4587 The file consists of a list of @dfn{news entries}. Each entry is
4588 associated with a commit or tag: it describes changes made in this
4589 commit, possibly in preceding commits as well. Users see entries only
4590 the first time they obtain the commit the entry refers to.
4592 The @code{title} field should be a one-line summary while @code{body}
4593 can be arbitrarily long, and both can contain Texinfo markup
4594 (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
4595 a list of language tag/message tuples, which allows @command{guix pull}
4596 to display news in the language that corresponds to the user's locale.
4598 If you want to translate news using a gettext-based workflow, you can
4599 extract translatable strings with @command{xgettext} (@pxref{xgettext
4600 Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
4601 you write news entries in English first, the command below creates a PO
4602 file containing the strings to translate:
4605 xgettext -o news.po -l scheme -ken etc/news.txt
4608 To sum up, yes, you could use your channel as a blog. But beware, this
4609 is @emph{not quite} what your users might expect.
4611 @subsection Replicating Guix
4613 @cindex pinning, channels
4614 @cindex replicating Guix
4615 @cindex reproducibility, of Guix
4616 The @command{guix pull --list-generations} output above shows precisely which
4617 commits were used to build this instance of Guix. We can thus replicate it,
4618 say, on another machine, by providing a channel specification in
4619 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
4622 ;; Deploy specific commits of my channels of interest.
4625 (url "https://git.savannah.gnu.org/git/guix.git")
4626 (commit "6298c3ffd9654d3231a6f25390b056483e8f407c"))
4628 (name 'my-personal-packages)
4629 (url "https://example.org/personal-packages.git")
4630 (commit "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
4633 The @command{guix describe --format=channels} command can even generate this
4634 list of channels directly (@pxref{Invoking guix describe}). The resulting
4635 file can be used with the -C options of @command{guix pull}
4636 (@pxref{Invoking guix pull}) or @command{guix time-machine}
4637 (@pxref{Invoking guix time-machine}).
4639 At this point the two machines run the @emph{exact same Guix}, with access to
4640 the @emph{exact same packages}. The output of @command{guix build gimp} on
4641 one machine will be exactly the same, bit for bit, as the output of the same
4642 command on the other machine. It also means both machines have access to all
4643 the source code of Guix and, transitively, to all the source code of every
4646 This gives you super powers, allowing you to track the provenance of binary
4647 artifacts with very fine grain, and to reproduce software environments at
4648 will---some sort of ``meta reproducibility'' capabilities, if you will.
4649 @xref{Inferiors}, for another way to take advantage of these super powers.
4651 @node Invoking guix time-machine
4652 @section Invoking @command{guix time-machine}
4654 @cindex @command{guix time-machine}
4655 @cindex pinning, channels
4656 @cindex replicating Guix
4657 @cindex reproducibility, of Guix
4659 The @command{guix time-machine} command provides access to other
4660 revisions of Guix, for example to install older versions of packages,
4661 or to reproduce a computation in an identical environment. The revision
4662 of Guix to be used is defined by a commit or by a channel
4663 description file created by @command{guix describe}
4664 (@pxref{Invoking guix describe}).
4666 The general syntax is:
4669 guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
4672 where @var{command} and @var{arg}@dots{} are passed unmodified to the
4673 @command{guix} command of the specified revision. The @var{options} that define
4674 this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
4677 @item --url=@var{url}
4678 @itemx --commit=@var{commit}
4679 @itemx --branch=@var{branch}
4680 Use the @code{guix} channel from the specified @var{url}, at the
4681 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4682 string), or @var{branch}.
4684 @item --channels=@var{file}
4685 @itemx -C @var{file}
4686 Read the list of channels from @var{file}. @var{file} must contain
4687 Scheme code that evaluates to a list of channel objects.
4688 @xref{Channels} for more information.
4691 As for @command{guix pull}, the absence of any options means that the
4692 the latest commit on the master branch will be used. The command
4695 guix time-machine -- build hello
4698 will thus build the package @code{hello} as defined in the master branch,
4699 which is in general a newer revision of Guix than you have installed.
4700 Time travel works in both directions!
4702 Note that @command{guix time-machine} can trigger builds of channels and
4703 their dependencies, and these are controlled by the standard build
4704 options (@pxref{Common Build Options}).
4709 @c TODO: Remove this once we're more confident about API stability.
4711 The functionality described here is a ``technology preview'' as of version
4712 @value{VERSION}. As such, the interface is subject to change.
4716 @cindex composition of Guix revisions
4717 Sometimes you might need to mix packages from the revision of Guix you're
4718 currently running with packages available in a different revision of Guix.
4719 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
4720 revisions in arbitrary ways.
4722 @cindex inferior packages
4723 Technically, an ``inferior'' is essentially a separate Guix process connected
4724 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4725 @code{(guix inferior)} module allows you to create inferiors and to
4726 communicate with them. It also provides a high-level interface to browse and
4727 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4729 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4730 to interact with a separate revision of Guix. For example, let's assume you
4731 want to install in your profile the current @code{guile} package, along with
4732 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4733 because the newer @code{guile-json} has an incompatible API and you want to
4734 run your code against the old API@. To do that, you could write a manifest for
4735 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4736 manifest, you would create an inferior for that old Guix revision you care
4737 about, and you would look up the @code{guile-json} package in the inferior:
4740 (use-modules (guix inferior) (guix channels)
4741 (srfi srfi-1)) ;for 'first'
4744 ;; This is the old revision from which we want to
4745 ;; extract guile-json.
4748 (url "https://git.savannah.gnu.org/git/guix.git")
4750 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4753 ;; An inferior representing the above revision.
4754 (inferior-for-channels channels))
4756 ;; Now create a manifest with the current "guile" package
4757 ;; and the old "guile-json" package.
4759 (list (first (lookup-inferior-packages inferior "guile-json"))
4760 (specification->package "guile")))
4763 On its first run, @command{guix package --manifest} might have to build the
4764 channel you specified before it can create the inferior; subsequent runs will
4765 be much faster because the Guix revision will be cached.
4767 The @code{(guix inferior)} module provides the following procedures to open an
4770 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4771 [#:cache-directory] [#:ttl]
4772 Return an inferior for @var{channels}, a list of channels. Use the cache at
4773 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4774 This procedure opens a new connection to the build daemon.
4776 As a side effect, this procedure may build or substitute binaries for
4777 @var{channels}, which can take time.
4780 @deffn {Scheme Procedure} open-inferior @var{directory} @
4781 [#:command "bin/guix"]
4782 Open the inferior Guix in @var{directory}, running
4783 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4784 the inferior could not be launched.
4787 @cindex inferior packages
4788 The procedures listed below allow you to obtain and manipulate inferior
4791 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4792 Return the list of packages known to @var{inferior}.
4795 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4797 Return the sorted list of inferior packages matching @var{name} in
4798 @var{inferior}, with highest version numbers first. If @var{version} is true,
4799 return only packages with a version number prefixed by @var{version}.
4802 @deffn {Scheme Procedure} inferior-package? @var{obj}
4803 Return true if @var{obj} is an inferior package.
4806 @deffn {Scheme Procedure} inferior-package-name @var{package}
4807 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4808 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4809 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4810 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4811 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4812 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4813 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4814 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4815 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4816 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4817 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4818 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4819 These procedures are the counterpart of package record accessors
4820 (@pxref{package Reference}). Most of them work by querying the inferior
4821 @var{package} comes from, so the inferior must still be live when you call
4825 Inferior packages can be used transparently like any other package or
4826 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4827 transparently handled by the @code{packages->manifest} procedure, which is
4828 commonly use in manifests (@pxref{Invoking guix package, the
4829 @option{--manifest} option of @command{guix package}}). Thus you can insert
4830 an inferior package pretty much anywhere you would insert a regular package:
4831 in manifests, in the @code{packages} field of your @code{operating-system}
4832 declaration, and so on.
4834 @node Invoking guix describe
4835 @section Invoking @command{guix describe}
4837 @cindex reproducibility
4838 @cindex replicating Guix
4839 Often you may want to answer questions like: ``Which revision of Guix am I
4840 using?'' or ``Which channels am I using?'' This is useful information in many
4841 situations: if you want to @emph{replicate} an environment on a different
4842 machine or user account, if you want to report a bug or to determine what
4843 change in the channels you are using caused it, or if you want to record your
4844 system state for reproducibility purposes. The @command{guix describe}
4845 command answers these questions.
4847 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4848 displays the channel(s) that it was built from, including their repository URL
4849 and commit IDs (@pxref{Channels}):
4853 Generation 10 Sep 03 2018 17:32:44 (current)
4855 repository URL: https://git.savannah.gnu.org/git/guix.git
4857 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4860 If you're familiar with the Git version control system, this is similar in
4861 spirit to @command{git describe}; the output is also similar to that of
4862 @command{guix pull --list-generations}, but limited to the current generation
4863 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4864 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4865 information is all it takes to describe the revision of Guix you're using, and
4866 also to replicate it.
4868 To make it easier to replicate Guix, @command{guix describe} can also be asked
4869 to return a list of channels instead of the human-readable description above:
4872 $ guix describe -f channels
4875 (url "https://git.savannah.gnu.org/git/guix.git")
4877 "e0fa68c7718fffd33d81af415279d6ddb518f727")
4879 (make-channel-introduction
4880 "9edb3f66fd807b096b48283debdcddccfea34bad"
4881 (openpgp-fingerprint
4882 "BBB0 2DDF 2CEA F6A8 0D1D E643 A2A0 6DF2 A33A 54FA")))))
4886 You can save this to a file and feed it to @command{guix pull -C} on some
4887 other machine or at a later point in time, which will instantiate @emph{this
4888 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4889 From there on, since you're able to deploy the same revision of Guix, you can
4890 just as well @emph{replicate a complete software environment}. We humbly
4891 think that this is @emph{awesome}, and we hope you'll like it too!
4893 The details of the options supported by @command{guix describe} are as
4897 @item --format=@var{format}
4898 @itemx -f @var{format}
4899 Produce output in the specified @var{format}, one of:
4903 produce human-readable output;
4905 produce a list of channel specifications that can be passed to @command{guix
4906 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4908 @item channels-sans-intro
4909 like @code{channels}, but omit the @code{introduction} field; use it to
4910 produce a channel specification suitable for Guix version 1.1.0 or
4911 earlier---the @code{introduction} field has to do with channel
4912 authentication (@pxref{Channels, Channel Authentication}) and is not
4913 supported by these older versions;
4916 produce a list of channel specifications in JSON format;
4918 produce a list of channel specifications in Recutils format.
4921 @item --list-formats
4922 Display available formats for @option{--format} option.
4924 @item --profile=@var{profile}
4925 @itemx -p @var{profile}
4926 Display information about @var{profile}.
4929 @node Invoking guix archive
4930 @section Invoking @command{guix archive}
4932 @cindex @command{guix archive}
4934 The @command{guix archive} command allows users to @dfn{export} files
4935 from the store into a single archive, and to later @dfn{import} them on
4936 a machine that runs Guix.
4937 In particular, it allows store files to be transferred from one machine
4938 to the store on another machine.
4941 If you're looking for a way to produce archives in a format suitable for
4942 tools other than Guix, @pxref{Invoking guix pack}.
4945 @cindex exporting store items
4946 To export store files as an archive to standard output, run:
4949 guix archive --export @var{options} @var{specifications}...
4952 @var{specifications} may be either store file names or package
4953 specifications, as for @command{guix package} (@pxref{Invoking guix
4954 package}). For instance, the following command creates an archive
4955 containing the @code{gui} output of the @code{git} package and the main
4956 output of @code{emacs}:
4959 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4962 If the specified packages are not built yet, @command{guix archive}
4963 automatically builds them. The build process may be controlled with the
4964 common build options (@pxref{Common Build Options}).
4966 To transfer the @code{emacs} package to a machine connected over SSH,
4970 guix archive --export -r emacs | ssh the-machine guix archive --import
4974 Similarly, a complete user profile may be transferred from one machine
4975 to another like this:
4978 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4979 ssh the-machine guix archive --import
4983 However, note that, in both examples, all of @code{emacs} and the
4984 profile as well as all of their dependencies are transferred (due to
4985 @option{-r}), regardless of what is already available in the store on
4986 the target machine. The @option{--missing} option can help figure out
4987 which items are missing from the target store. The @command{guix copy}
4988 command simplifies and optimizes this whole process, so this is probably
4989 what you should use in this case (@pxref{Invoking guix copy}).
4991 @cindex nar, archive format
4992 @cindex normalized archive (nar)
4993 @cindex nar bundle, archive format
4994 Each store item is written in the @dfn{normalized archive} or @dfn{nar}
4995 format (described below), and the output of @command{guix archive
4996 --export} (and input of @command{guix archive --import}) is a @dfn{nar
5000 comparable in spirit to `tar', but with differences
5001 that make it more appropriate for our purposes. First, rather than
5002 recording all Unix metadata for each file, the nar format only mentions
5003 the file type (regular, directory, or symbolic link); Unix permissions
5004 and owner/group are dismissed. Second, the order in which directory
5005 entries are stored always follows the order of file names according to
5006 the C locale collation order. This makes archive production fully
5009 That nar bundle format is essentially the concatenation of zero or more
5010 nars along with metadata for each store item it contains: its file name,
5011 references, corresponding derivation, and a digital signature.
5013 When exporting, the daemon digitally signs the contents of the archive,
5014 and that digital signature is appended. When importing, the daemon
5015 verifies the signature and rejects the import in case of an invalid
5016 signature or if the signing key is not authorized.
5017 @c FIXME: Add xref to daemon doc about signatures.
5019 The main options are:
5023 Export the specified store files or packages (see below). Write the
5024 resulting archive to the standard output.
5026 Dependencies are @emph{not} included in the output, unless
5027 @option{--recursive} is passed.
5031 When combined with @option{--export}, this instructs @command{guix archive}
5032 to include dependencies of the given items in the archive. Thus, the
5033 resulting archive is self-contained: it contains the closure of the
5034 exported store items.
5037 Read an archive from the standard input, and import the files listed
5038 therein into the store. Abort if the archive has an invalid digital
5039 signature, or if it is signed by a public key not among the authorized
5040 keys (see @option{--authorize} below).
5043 Read a list of store file names from the standard input, one per line,
5044 and write on the standard output the subset of these files missing from
5047 @item --generate-key[=@var{parameters}]
5048 @cindex signing, archives
5049 Generate a new key pair for the daemon. This is a prerequisite before
5050 archives can be exported with @option{--export}. Note that this
5051 operation usually takes time, because it needs to gather enough entropy
5052 to generate the key pair.
5054 The generated key pair is typically stored under @file{/etc/guix}, in
5055 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
5056 key, which must be kept secret). When @var{parameters} is omitted,
5057 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
5058 versions before 1.6.0, it is a 4096-bit RSA key.
5059 Alternatively, @var{parameters} can specify
5060 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
5061 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
5062 Libgcrypt Reference Manual}).
5065 @cindex authorizing, archives
5066 Authorize imports signed by the public key passed on standard input.
5067 The public key must be in ``s-expression advanced format''---i.e., the
5068 same format as the @file{signing-key.pub} file.
5070 The list of authorized keys is kept in the human-editable file
5071 @file{/etc/guix/acl}. The file contains
5072 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
5073 s-expressions''} and is structured as an access-control list in the
5074 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
5077 @item --extract=@var{directory}
5078 @itemx -x @var{directory}
5079 Read a single-item archive as served by substitute servers
5080 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
5081 low-level operation needed in only very narrow use cases; see below.
5083 For example, the following command extracts the substitute for Emacs
5084 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
5088 https://@value{SUBSTITUTE-SERVER}/nar/gzip/@dots{}-emacs-24.5 \
5089 | gunzip | guix archive -x /tmp/emacs
5092 Single-item archives are different from multiple-item archives produced
5093 by @command{guix archive --export}; they contain a single store item,
5094 and they do @emph{not} embed a signature. Thus this operation does
5095 @emph{no} signature verification and its output should be considered
5098 The primary purpose of this operation is to facilitate inspection of
5099 archive contents coming from possibly untrusted substitute servers
5100 (@pxref{Invoking guix challenge}).
5104 Read a single-item archive as served by substitute servers
5105 (@pxref{Substitutes}) and print the list of files it contains, as in
5110 https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-emacs-26.3 \
5111 | lzip -d | guix archive -t
5117 @c *********************************************************************
5119 @chapter Development
5121 @cindex software development
5122 If you are a software developer, Guix provides tools that you should find
5123 helpful---independently of the language you're developing in. This is what
5124 this chapter is about.
5126 The @command{guix environment} command provides a convenient way to set up
5127 @dfn{development environments} containing all the dependencies and tools
5128 necessary to work on the software package of your choice. The @command{guix
5129 pack} command allows you to create @dfn{application bundles} that can be
5130 easily distributed to users who do not run Guix.
5133 * Invoking guix environment:: Setting up development environments.
5134 * Invoking guix pack:: Creating software bundles.
5135 * The GCC toolchain:: Working with languages supported by GCC.
5136 * Invoking guix git authenticate:: Authenticating Git repositories.
5139 @node Invoking guix environment
5140 @section Invoking @command{guix environment}
5142 @cindex reproducible build environments
5143 @cindex development environments
5144 @cindex @command{guix environment}
5145 @cindex environment, package build environment
5146 The purpose of @command{guix environment} is to assist hackers in
5147 creating reproducible development environments without polluting their
5148 package profile. The @command{guix environment} tool takes one or more
5149 packages, builds all of their inputs, and creates a shell
5150 environment to use them.
5152 The general syntax is:
5155 guix environment @var{options} @var{package}@dots{}
5158 The following example spawns a new shell set up for the development of
5162 guix environment guile
5165 If the needed dependencies are not built yet, @command{guix environment}
5166 automatically builds them. The environment of the new shell is an
5167 augmented version of the environment that @command{guix environment} was
5168 run in. It contains the necessary search paths for building the given
5169 package added to the existing environment variables. To create
5170 a ``pure'' environment, in which the original environment variables have
5171 been unset, use the @option{--pure} option@footnote{Users sometimes
5172 wrongfully augment environment variables such as @env{PATH} in their
5173 @file{~/.bashrc} file. As a consequence, when @command{guix
5174 environment} launches it, Bash may read @file{~/.bashrc}, thereby
5175 introducing ``impurities'' in these environment variables. It is an
5176 error to define such environment variables in @file{.bashrc}; instead,
5177 they should be defined in @file{.bash_profile}, which is sourced only by
5178 log-in shells. @xref{Bash Startup Files,,, bash, The GNU Bash Reference
5179 Manual}, for details on Bash start-up files.}.
5181 @vindex GUIX_ENVIRONMENT
5182 @command{guix environment} defines the @env{GUIX_ENVIRONMENT}
5183 variable in the shell it spawns; its value is the file name of the
5184 profile of this environment. This allows users to, say, define a
5185 specific prompt for development environments in their @file{.bashrc}
5186 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
5189 if [ -n "$GUIX_ENVIRONMENT" ]
5191 export PS1="\u@@\h \w [dev]\$ "
5196 ...@: or to browse the profile:
5199 $ ls "$GUIX_ENVIRONMENT/bin"
5202 Additionally, more than one package may be specified, in which case the
5203 union of the inputs for the given packages are used. For example, the
5204 command below spawns a shell where all of the dependencies of both Guile
5205 and Emacs are available:
5208 guix environment guile emacs
5211 Sometimes an interactive shell session is not desired. An arbitrary
5212 command may be invoked by placing the @code{--} token to separate the
5213 command from the rest of the arguments:
5216 guix environment guile -- make -j4
5219 In other situations, it is more convenient to specify the list of
5220 packages needed in the environment. For example, the following command
5221 runs @command{python} from an environment containing Python@tie{}2.7 and
5225 guix environment --ad-hoc python2-numpy python-2.7 -- python
5228 Furthermore, one might want the dependencies of a package and also some
5229 additional packages that are not build-time or runtime dependencies, but
5230 are useful when developing nonetheless. Because of this, the
5231 @option{--ad-hoc} flag is positional. Packages appearing before
5232 @option{--ad-hoc} are interpreted as packages whose dependencies will be
5233 added to the environment. Packages appearing after are interpreted as
5234 packages that will be added to the environment directly. For example,
5235 the following command creates a Guix development environment that
5236 additionally includes Git and strace:
5239 guix environment --pure guix --ad-hoc git strace
5243 Sometimes it is desirable to isolate the environment as much as
5244 possible, for maximal purity and reproducibility. In particular, when
5245 using Guix on a host distro that is not Guix System, it is desirable to
5246 prevent access to @file{/usr/bin} and other system-wide resources from
5247 the development environment. For example, the following command spawns
5248 a Guile REPL in a ``container'' where only the store and the current
5249 working directory are mounted:
5252 guix environment --ad-hoc --container guile -- guile
5256 The @option{--container} option requires Linux-libre 3.19 or newer.
5259 @cindex certificates
5260 Another typical use case for containers is to run security-sensitive
5261 applications such as a web browser. To run Eolie, we must expose and
5262 share some files and directories; we include @code{nss-certs} and expose
5263 @file{/etc/ssl/certs/} for HTTPS authentication; finally we preserve the
5264 the @env{DISPLAY} environment variable since containerized graphical
5265 applications won't display without it.
5268 guix environment --preserve='^DISPLAY$' --container --network \
5269 --expose=/etc/machine-id \
5270 --expose=/etc/ssl/certs/ \
5271 --share=$HOME/.local/share/eolie/=$HOME/.local/share/eolie/ \
5272 --ad-hoc eolie nss-certs dbus -- eolie
5275 The available options are summarized below.
5278 @item --root=@var{file}
5279 @itemx -r @var{file}
5280 @cindex persistent environment
5281 @cindex garbage collector root, for environments
5282 Make @var{file} a symlink to the profile for this environment, and
5283 register it as a garbage collector root.
5285 This is useful if you want to protect your environment from garbage
5286 collection, to make it ``persistent''.
5288 When this option is omitted, the environment is protected from garbage
5289 collection only for the duration of the @command{guix environment}
5290 session. This means that next time you recreate the same environment,
5291 you could have to rebuild or re-download packages. @xref{Invoking guix
5292 gc}, for more on GC roots.
5294 @item --expression=@var{expr}
5295 @itemx -e @var{expr}
5296 Create an environment for the package or list of packages that
5297 @var{expr} evaluates to.
5299 For example, running:
5302 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
5305 starts a shell with the environment for this specific variant of the
5311 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
5314 starts a shell with all the base system packages available.
5316 The above commands only use the default output of the given packages.
5317 To select other outputs, two element tuples can be specified:
5320 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
5323 @item --load=@var{file}
5324 @itemx -l @var{file}
5325 Create an environment for the package or list of packages that the code
5326 within @var{file} evaluates to.
5328 As an example, @var{file} might contain a definition like this
5329 (@pxref{Defining Packages}):
5332 @verbatiminclude environment-gdb.scm
5335 @item --manifest=@var{file}
5336 @itemx -m @var{file}
5337 Create an environment for the packages contained in the manifest object
5338 returned by the Scheme code in @var{file}. This option can be repeated
5339 several times, in which case the manifests are concatenated.
5341 This is similar to the same-named option in @command{guix package}
5342 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
5346 Include all specified packages in the resulting environment, as if an
5347 @i{ad hoc} package were defined with them as inputs. This option is
5348 useful for quickly creating an environment without having to write a
5349 package expression to contain the desired inputs.
5351 For instance, the command:
5354 guix environment --ad-hoc guile guile-sdl -- guile
5357 runs @command{guile} in an environment where Guile and Guile-SDL are
5360 Note that this example implicitly asks for the default output of
5361 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
5362 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
5363 of @code{glib} (@pxref{Packages with Multiple Outputs}).
5365 This option may be composed with the default behavior of @command{guix
5366 environment}. Packages appearing before @option{--ad-hoc} are
5367 interpreted as packages whose dependencies will be added to the
5368 environment, the default behavior. Packages appearing after are
5369 interpreted as packages that will be added to the environment directly.
5372 Unset existing environment variables when building the new environment, except
5373 those specified with @option{--preserve} (see below). This has the effect of
5374 creating an environment in which search paths only contain package inputs.
5376 @item --preserve=@var{regexp}
5377 @itemx -E @var{regexp}
5378 When used alongside @option{--pure}, preserve the environment variables
5379 matching @var{regexp}---in other words, put them on a ``white list'' of
5380 environment variables that must be preserved. This option can be repeated
5384 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
5388 This example runs @command{mpirun} in a context where the only environment
5389 variables defined are @env{PATH}, environment variables whose name starts
5390 with @samp{SLURM}, as well as the usual ``precious'' variables (@env{HOME},
5393 @item --search-paths
5394 Display the environment variable definitions that make up the
5397 @item --system=@var{system}
5398 @itemx -s @var{system}
5399 Attempt to build for @var{system}---e.g., @code{i686-linux}.
5404 Run @var{command} within an isolated container. The current working
5405 directory outside the container is mapped inside the container.
5406 Additionally, unless overridden with @option{--user}, a dummy home
5407 directory is created that matches the current user's home directory, and
5408 @file{/etc/passwd} is configured accordingly.
5410 The spawned process runs as the current user outside the container. Inside
5411 the container, it has the same UID and GID as the current user, unless
5412 @option{--user} is passed (see below).
5416 For containers, share the network namespace with the host system.
5417 Containers created without this flag only have access to the loopback
5420 @item --link-profile
5422 For containers, link the environment profile to @file{~/.guix-profile}
5423 within the container. This is equivalent to running the command
5424 @samp{ln -s $GUIX_ENVIRONMENT ~/.guix-profile} within the container.
5425 Linking will fail and abort the environment if the directory already
5426 exists, which will certainly be the case if @command{guix environment}
5427 was invoked in the user's home directory.
5429 Certain packages are configured to look in @file{~/.guix-profile} for
5430 configuration files and data;@footnote{For example, the
5431 @code{fontconfig} package inspects @file{~/.guix-profile/share/fonts}
5432 for additional fonts.} @option{--link-profile} allows these programs to
5433 behave as expected within the environment.
5435 @item --user=@var{user}
5436 @itemx -u @var{user}
5437 For containers, use the username @var{user} in place of the current
5438 user. The generated @file{/etc/passwd} entry within the container will
5439 contain the name @var{user}, the home directory will be
5440 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
5441 the UID and GID inside the container are 1000. @var{user}
5442 need not exist on the system.
5444 Additionally, any shared or exposed path (see @option{--share} and
5445 @option{--expose} respectively) whose target is within the current user's
5446 home directory will be remapped relative to @file{/home/USER}; this
5447 includes the automatic mapping of the current working directory.
5450 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
5452 guix environment --container --user=foo \
5453 --expose=$HOME/test \
5454 --expose=/tmp/target=$HOME/target
5457 While this will limit the leaking of user identity through home paths
5458 and each of the user fields, this is only one useful component of a
5459 broader privacy/anonymity solution---not one in and of itself.
5462 For containers, the default behavior is to share the current working
5463 directory with the isolated container and immediately change to that
5464 directory within the container. If this is undesirable,
5465 @option{--no-cwd} will cause the current working directory to @emph{not}
5466 be automatically shared and will change to the user's home directory
5467 within the container instead. See also @option{--user}.
5469 @item --expose=@var{source}[=@var{target}]
5470 @itemx --share=@var{source}[=@var{target}]
5471 For containers, @option{--expose} (resp. @option{--share}) exposes the
5472 file system @var{source} from the host system as the read-only
5473 (resp. writable) file system @var{target} within the container. If
5474 @var{target} is not specified, @var{source} is used as the target mount
5475 point in the container.
5477 The example below spawns a Guile REPL in a container in which the user's
5478 home directory is accessible read-only via the @file{/exchange}
5482 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
5487 @command{guix environment}
5488 also supports all of the common build options that @command{guix
5489 build} supports (@pxref{Common Build Options}) as well as package
5490 transformation options (@pxref{Package Transformation Options}).
5492 @node Invoking guix pack
5493 @section Invoking @command{guix pack}
5495 Occasionally you want to pass software to people who are not (yet!)
5496 lucky enough to be using Guix. You'd tell them to run @command{guix
5497 package -i @var{something}}, but that's not possible in this case. This
5498 is where @command{guix pack} comes in.
5501 If you are looking for ways to exchange binaries among machines that
5502 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
5503 publish}, and @ref{Invoking guix archive}.
5508 @cindex application bundle
5509 @cindex software bundle
5510 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
5511 @dfn{software bundle}: it creates a tarball or some other archive
5512 containing the binaries of the software you're interested in, and all
5513 its dependencies. The resulting archive can be used on any machine that
5514 does not have Guix, and people can run the exact same binaries as those
5515 you have with Guix. The pack itself is created in a bit-reproducible
5516 fashion, so anyone can verify that it really contains the build results
5517 that you pretend to be shipping.
5519 For example, to create a bundle containing Guile, Emacs, Geiser, and all
5520 their dependencies, you can run:
5523 $ guix pack guile emacs geiser
5525 /gnu/store/@dots{}-pack.tar.gz
5528 The result here is a tarball containing a @file{/gnu/store} directory
5529 with all the relevant packages. The resulting tarball contains a
5530 @dfn{profile} with the three packages of interest; the profile is the
5531 same as would be created by @command{guix package -i}. It is this
5532 mechanism that is used to create Guix's own standalone binary tarball
5533 (@pxref{Binary Installation}).
5535 Users of this pack would have to run
5536 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
5537 find inconvenient. To work around it, you can create, say, a
5538 @file{/opt/gnu/bin} symlink to the profile:
5541 guix pack -S /opt/gnu/bin=bin guile emacs geiser
5545 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
5547 @cindex relocatable binaries, with @command{guix pack}
5548 What if the recipient of your pack does not have root privileges on
5549 their machine, and thus cannot unpack it in the root file system? In
5550 that case, you will want to use the @option{--relocatable} option (see
5551 below). This option produces @dfn{relocatable binaries}, meaning they
5552 they can be placed anywhere in the file system hierarchy: in the example
5553 above, users can unpack your tarball in their home directory and
5554 directly run @file{./opt/gnu/bin/guile}.
5556 @cindex Docker, build an image with guix pack
5557 Alternatively, you can produce a pack in the Docker image format using
5558 the following command:
5561 guix pack -f docker -S /bin=bin guile guile-readline
5565 The result is a tarball that can be passed to the @command{docker load}
5566 command, followed by @code{docker run}:
5569 docker load < @var{file}
5570 docker run -ti guile-guile-readline /bin/guile
5574 where @var{file} is the image returned by @var{guix pack}, and
5575 @code{guile-guile-readline} is its ``image tag''. See the
5576 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5577 documentation} for more information.
5579 @cindex Singularity, build an image with guix pack
5580 @cindex SquashFS, build an image with guix pack
5581 Yet another option is to produce a SquashFS image with the following
5585 guix pack -f squashfs bash guile emacs geiser
5589 The result is a SquashFS file system image that can either be mounted or
5590 directly be used as a file system container image with the
5591 @uref{https://www.sylabs.io/docs/, Singularity container execution
5592 environment}, using commands like @command{singularity shell} or
5593 @command{singularity exec}.
5595 Several command-line options allow you to customize your pack:
5598 @item --format=@var{format}
5599 @itemx -f @var{format}
5600 Produce a pack in the given @var{format}.
5602 The available formats are:
5606 This is the default format. It produces a tarball containing all the
5607 specified binaries and symlinks.
5610 This produces a tarball that follows the
5611 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
5612 Docker Image Specification}. The ``repository name'' as it appears in
5613 the output of the @command{docker images} command is computed from
5614 package names passed on the command line or in the manifest file.
5617 This produces a SquashFS image containing all the specified binaries and
5618 symlinks, as well as empty mount points for virtual file systems like
5622 Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
5623 For that reason, @command{guix pack -f squashfs} always implies @code{-S
5624 /bin=bin}. Thus, your @command{guix pack} invocation must always start
5625 with something like:
5628 guix pack -f squashfs bash @dots{}
5631 If you forget the @code{bash} (or similar) package, @command{singularity
5632 run} and @command{singularity exec} will fail with an unhelpful ``no
5633 such file or directory'' message.
5637 @cindex relocatable binaries
5640 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
5641 anywhere in the file system hierarchy and run from there.
5643 When this option is passed once, the resulting binaries require support for
5644 @dfn{user namespaces} in the kernel Linux; when passed
5645 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
5646 PRoot support, can be thought of as the abbreviation of ``Really
5647 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to
5648 other techniques if user namespaces are unavailable, and essentially
5649 work anywhere---see below for the implications.
5651 For example, if you create a pack containing Bash with:
5654 guix pack -RR -S /mybin=bin bash
5658 ...@: you can copy that pack to a machine that lacks Guix, and from your
5659 home directory as a normal user, run:
5667 In that shell, if you type @code{ls /gnu/store}, you'll notice that
5668 @file{/gnu/store} shows up and contains all the dependencies of
5669 @code{bash}, even though the machine actually lacks @file{/gnu/store}
5670 altogether! That is probably the simplest way to deploy Guix-built
5671 software on a non-Guix machine.
5674 By default, relocatable binaries rely on the @dfn{user namespace} feature of
5675 the kernel Linux, which allows unprivileged users to mount or change root.
5676 Old versions of Linux did not support it, and some GNU/Linux distributions
5679 To produce relocatable binaries that work even in the absence of user
5680 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
5681 case, binaries will try user namespace support and fall back to another
5682 @dfn{execution engine} if user namespaces are not supported. The
5683 following execution engines are supported:
5687 Try user namespaces and fall back to PRoot if user namespaces are not
5688 supported (see below).
5691 Try user namespaces and fall back to Fakechroot if user namespaces are
5692 not supported (see below).
5695 Run the program through user namespaces and abort if they are not
5699 Run through PRoot. The @uref{https://proot-me.github.io/, PRoot} program
5700 provides the necessary
5701 support for file system virtualization. It achieves that by using the
5702 @code{ptrace} system call on the running program. This approach has the
5703 advantage to work without requiring special kernel support, but it incurs
5704 run-time overhead every time a system call is made.
5707 Run through Fakechroot. @uref{https://github.com/dex4er/fakechroot/,
5708 Fakechroot} virtualizes file system accesses by intercepting calls to C
5709 library functions such as @code{open}, @code{stat}, @code{exec}, and so
5710 on. Unlike PRoot, it incurs very little overhead. However, it does not
5711 always work: for example, some file system accesses made from within the
5712 C library are not intercepted, and file system accesses made @i{via}
5713 direct syscalls are not intercepted either, leading to erratic behavior.
5716 @vindex GUIX_EXECUTION_ENGINE
5717 When running a wrapped program, you can explicitly request one of the
5718 execution engines listed above by setting the
5719 @code{GUIX_EXECUTION_ENGINE} environment variable accordingly.
5722 @cindex entry point, for Docker images
5723 @item --entry-point=@var{command}
5724 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
5725 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
5726 support it. @var{command} must be relative to the profile contained in the
5729 The entry point specifies the command that tools like @code{docker run} or
5730 @code{singularity run} automatically start by default. For example, you can
5734 guix pack -f docker --entry-point=bin/guile guile
5737 The resulting pack can easily be loaded and @code{docker run} with no extra
5738 arguments will spawn @code{bin/guile}:
5741 docker load -i pack.tar.gz
5742 docker run @var{image-id}
5745 @item --expression=@var{expr}
5746 @itemx -e @var{expr}
5747 Consider the package @var{expr} evaluates to.
5749 This has the same purpose as the same-named option in @command{guix
5750 build} (@pxref{Additional Build Options, @option{--expression} in
5751 @command{guix build}}).
5753 @item --manifest=@var{file}
5754 @itemx -m @var{file}
5755 Use the packages contained in the manifest object returned by the Scheme
5756 code in @var{file}. This option can be repeated several times, in which
5757 case the manifests are concatenated.
5759 This has a similar purpose as the same-named option in @command{guix
5760 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
5761 same manifest files. It allows you to define a collection of packages
5762 once and use it both for creating profiles and for creating archives
5763 for use on machines that do not have Guix installed. Note that you can
5764 specify @emph{either} a manifest file @emph{or} a list of packages,
5767 @item --system=@var{system}
5768 @itemx -s @var{system}
5769 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
5770 the system type of the build host.
5772 @item --target=@var{triplet}
5773 @cindex cross-compilation
5774 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
5775 as @code{"aarch64-linux-gnu"} (@pxref{Specifying target triplets, GNU
5776 configuration triplets,, autoconf, Autoconf}).
5778 @item --compression=@var{tool}
5779 @itemx -C @var{tool}
5780 Compress the resulting tarball using @var{tool}---one of @code{gzip},
5781 @code{zstd}, @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no
5784 @item --symlink=@var{spec}
5785 @itemx -S @var{spec}
5786 Add the symlinks specified by @var{spec} to the pack. This option can
5787 appear several times.
5789 @var{spec} has the form @code{@var{source}=@var{target}}, where
5790 @var{source} is the symlink that will be created and @var{target} is the
5793 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
5794 symlink pointing to the @file{bin} sub-directory of the profile.
5796 @item --save-provenance
5797 Save provenance information for the packages passed on the command line.
5798 Provenance information includes the URL and commit of the channels in use
5801 Provenance information is saved in the
5802 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
5803 usual package metadata---the name and version of each package, their
5804 propagated inputs, and so on. It is useful information to the recipient of
5805 the pack, who then knows how the pack was (supposedly) obtained.
5807 This option is not enabled by default because, like timestamps, provenance
5808 information contributes nothing to the build process. In other words, there
5809 is an infinity of channel URLs and commit IDs that can lead to the same pack.
5810 Recording such ``silent'' metadata in the output thus potentially breaks the
5811 source-to-binary bitwise reproducibility property.
5813 @item --root=@var{file}
5814 @itemx -r @var{file}
5815 @cindex garbage collector root, for packs
5816 Make @var{file} a symlink to the resulting pack, and register it as a garbage
5819 @item --localstatedir
5820 @itemx --profile-name=@var{name}
5821 Include the ``local state directory'', @file{/var/guix}, in the resulting
5822 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
5823 profile---by default @var{name} is @code{guix-profile}, which corresponds to
5824 @file{~root/.guix-profile}.
5826 @file{/var/guix} contains the store database (@pxref{The Store}) as well
5827 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
5828 the pack means that the store is ``complete'' and manageable by Guix;
5829 not providing it pack means that the store is ``dead'': items cannot be
5830 added to it or removed from it after extraction of the pack.
5832 One use case for this is the Guix self-contained binary tarball
5833 (@pxref{Binary Installation}).
5837 Print the name of the derivation that builds the pack.
5840 Use the bootstrap binaries to build the pack. This option is only
5841 useful to Guix developers.
5844 In addition, @command{guix pack} supports all the common build options
5845 (@pxref{Common Build Options}) and all the package transformation
5846 options (@pxref{Package Transformation Options}).
5849 @node The GCC toolchain
5850 @section The GCC toolchain
5854 @cindex linker wrapper
5855 @cindex toolchain, for C development
5856 @cindex toolchain, for Fortran development
5858 If you need a complete toolchain for compiling and linking C or C++
5859 source code, use the @code{gcc-toolchain} package. This package
5860 provides a complete GCC toolchain for C/C++ development, including GCC
5861 itself, the GNU C Library (headers and binaries, plus debugging symbols
5862 in the @code{debug} output), Binutils, and a linker wrapper.
5864 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
5865 passed to the linker, add corresponding @code{-rpath} arguments, and
5866 invoke the actual linker with this new set of arguments. You can instruct the
5867 wrapper to refuse to link against libraries not in the store by setting the
5868 @env{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
5870 The package @code{gfortran-toolchain} provides a complete GCC toolchain
5871 for Fortran development. For other languages, please use
5872 @samp{guix search gcc toolchain} (@pxref{guix-search,, Invoking guix package}).
5875 @node Invoking guix git authenticate
5876 @section Invoking @command{guix git authenticate}
5878 The @command{guix git authenticate} command authenticates a Git checkout
5879 following the same rule as for channels (@pxref{channel-authentication,
5880 channel authentication}). That is, starting from a given commit, it
5881 ensures that all subsequent commits are signed by an OpenPGP key whose
5882 fingerprint appears in the @file{.guix-authorizations} file of its
5885 You will find this command useful if you maintain a channel. But in
5886 fact, this authentication mechanism is useful in a broader context, so
5887 you might want to use it for Git repositories that have nothing to do
5890 The general syntax is:
5893 guix git authenticate @var{commit} @var{signer} [@var{options}@dots{}]
5896 By default, this command authenticates the Git checkout in the current
5897 directory; it outputs nothing and exits with exit code zero on success
5898 and non-zero on failure. @var{commit} above denotes the first commit
5899 where authentication takes place, and @var{signer} is the OpenPGP
5900 fingerprint of public key used to sign @var{commit}. Together, they
5901 form a ``channel introduction'' (@pxref{channel-authentication, channel
5902 introduction}). The options below allow you to fine-tune the process.
5905 @item --repository=@var{directory}
5906 @itemx -r @var{directory}
5907 Open the Git repository in @var{directory} instead of the current
5910 @item --keyring=@var{reference}
5911 @itemx -k @var{reference}
5912 Load OpenPGP keyring from @var{reference}, the reference of a branch
5913 such as @code{origin/keyring} or @code{my-keyring}. The branch must
5914 contain OpenPGP public keys in @file{.key} files, either in binary form
5915 or ``ASCII-armored''. By default the keyring is loaded from the branch
5916 named @code{keyring}.
5919 Display commit signing statistics upon completion.
5921 @item --cache-key=@var{key}
5922 Previously-authenticated commits are cached in a file under
5923 @file{~/.cache/guix/authentication}. This option forces the cache to be
5924 stored in file @var{key} in that directory.
5926 @item --historical-authorizations=@var{file}
5927 By default, any commit whose parent commit(s) lack the
5928 @file{.guix-authorizations} file is considered inauthentic. In
5929 contrast, this option considers the authorizations in @var{file} for any
5930 commit that lacks @file{.guix-authorizations}. The format of @var{file}
5931 is the same as that of @file{.guix-authorizations}
5932 (@pxref{channel-authorizations, @file{.guix-authorizations} format}).
5936 @c *********************************************************************
5937 @node Programming Interface
5938 @chapter Programming Interface
5940 GNU Guix provides several Scheme programming interfaces (APIs) to
5941 define, build, and query packages. The first interface allows users to
5942 write high-level package definitions. These definitions refer to
5943 familiar packaging concepts, such as the name and version of a package,
5944 its build system, and its dependencies. These definitions can then be
5945 turned into concrete build actions.
5947 Build actions are performed by the Guix daemon, on behalf of users. In a
5948 standard setup, the daemon has write access to the store---the
5949 @file{/gnu/store} directory---whereas users do not. The recommended
5950 setup also has the daemon perform builds in chroots, under specific
5951 build users, to minimize interference with the rest of the system.
5954 Lower-level APIs are available to interact with the daemon and the
5955 store. To instruct the daemon to perform a build action, users actually
5956 provide it with a @dfn{derivation}. A derivation is a low-level
5957 representation of the build actions to be taken, and the environment in
5958 which they should occur---derivations are to package definitions what
5959 assembly is to C programs. The term ``derivation'' comes from the fact
5960 that build results @emph{derive} from them.
5962 This chapter describes all these APIs in turn, starting from high-level
5963 package definitions.
5966 * Package Modules:: Packages from the programmer's viewpoint.
5967 * Defining Packages:: Defining new packages.
5968 * Build Systems:: Specifying how packages are built.
5969 * The Store:: Manipulating the package store.
5970 * Derivations:: Low-level interface to package derivations.
5971 * The Store Monad:: Purely functional interface to the store.
5972 * G-Expressions:: Manipulating build expressions.
5973 * Invoking guix repl:: Programming Guix in Guile
5976 @node Package Modules
5977 @section Package Modules
5979 From a programming viewpoint, the package definitions of the
5980 GNU distribution are provided by Guile modules in the @code{(gnu packages
5981 @dots{})} name space@footnote{Note that packages under the @code{(gnu
5982 packages @dots{})} module name space are not necessarily ``GNU
5983 packages''. This module naming scheme follows the usual Guile module
5984 naming convention: @code{gnu} means that these modules are distributed
5985 as part of the GNU system, and @code{packages} identifies modules that
5986 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5987 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5988 module exports a variable named @code{emacs}, which is bound to a
5989 @code{<package>} object (@pxref{Defining Packages}).
5991 The @code{(gnu packages @dots{})} module name space is
5992 automatically scanned for packages by the command-line tools. For
5993 instance, when running @code{guix install emacs}, all the @code{(gnu
5994 packages @dots{})} modules are scanned until one that exports a package
5995 object whose name is @code{emacs} is found. This package search
5996 facility is implemented in the @code{(gnu packages)} module.
5998 @cindex customization, of packages
5999 @cindex package module search path
6000 Users can store package definitions in modules with different
6001 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
6002 name and module name must match. For instance, the @code{(my-packages
6003 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
6004 relative to the load path specified with @option{--load-path} or
6005 @env{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
6006 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
6007 these package definitions visible to the user interfaces:
6011 By adding the directory containing your package modules to the search path
6012 with the @code{-L} flag of @command{guix package} and other commands
6013 (@pxref{Common Build Options}), or by setting the @env{GUIX_PACKAGE_PATH}
6014 environment variable described below.
6017 By defining a @dfn{channel} and configuring @command{guix pull} so that it
6018 pulls from it. A channel is essentially a Git repository containing package
6019 modules. @xref{Channels}, for more information on how to define and use
6023 @env{GUIX_PACKAGE_PATH} works similarly to other search path variables:
6025 @defvr {Environment Variable} GUIX_PACKAGE_PATH
6026 This is a colon-separated list of directories to search for additional
6027 package modules. Directories listed in this variable take precedence
6028 over the own modules of the distribution.
6031 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
6032 each package is built based solely on other packages in the
6033 distribution. The root of this dependency graph is a small set of
6034 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
6035 bootstrap)} module. For more information on bootstrapping,
6036 @pxref{Bootstrapping}.
6038 @node Defining Packages
6039 @section Defining Packages
6041 The high-level interface to package definitions is implemented in the
6042 @code{(guix packages)} and @code{(guix build-system)} modules. As an
6043 example, the package definition, or @dfn{recipe}, for the GNU Hello
6044 package looks like this:
6047 (define-module (gnu packages hello)
6048 #:use-module (guix packages)
6049 #:use-module (guix download)
6050 #:use-module (guix build-system gnu)
6051 #:use-module (guix licenses)
6052 #:use-module (gnu packages gawk))
6054 (define-public hello
6060 (uri (string-append "mirror://gnu/hello/hello-" version
6064 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
6065 (build-system gnu-build-system)
6066 (arguments '(#:configure-flags '("--enable-silent-rules")))
6067 (inputs `(("gawk" ,gawk)))
6068 (synopsis "Hello, GNU world: An example GNU package")
6069 (description "Guess what GNU Hello prints!")
6070 (home-page "https://www.gnu.org/software/hello/")
6075 Without being a Scheme expert, the reader may have guessed the meaning
6076 of the various fields here. This expression binds the variable
6077 @code{hello} to a @code{<package>} object, which is essentially a record
6078 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
6079 This package object can be inspected using procedures found in the
6080 @code{(guix packages)} module; for instance, @code{(package-name hello)}
6081 returns---surprise!---@code{"hello"}.
6083 With luck, you may be able to import part or all of the definition of
6084 the package you are interested in from another repository, using the
6085 @code{guix import} command (@pxref{Invoking guix import}).
6087 In the example above, @var{hello} is defined in a module of its own,
6088 @code{(gnu packages hello)}. Technically, this is not strictly
6089 necessary, but it is convenient to do so: all the packages defined in
6090 modules under @code{(gnu packages @dots{})} are automatically known to
6091 the command-line tools (@pxref{Package Modules}).
6093 There are a few points worth noting in the above package definition:
6097 The @code{source} field of the package is an @code{<origin>} object
6098 (@pxref{origin Reference}, for the complete reference).
6099 Here, the @code{url-fetch} method from @code{(guix download)} is used,
6100 meaning that the source is a file to be downloaded over FTP or HTTP.
6102 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
6103 the GNU mirrors defined in @code{(guix download)}.
6105 The @code{sha256} field specifies the expected SHA256 hash of the file
6106 being downloaded. It is mandatory, and allows Guix to check the
6107 integrity of the file. The @code{(base32 @dots{})} form introduces the
6108 base32 representation of the hash. You can obtain this information with
6109 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
6110 hash} (@pxref{Invoking guix hash}).
6113 When needed, the @code{origin} form can also have a @code{patches} field
6114 listing patches to be applied, and a @code{snippet} field giving a
6115 Scheme expression to modify the source code.
6118 @cindex GNU Build System
6119 The @code{build-system} field specifies the procedure to build the
6120 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
6121 represents the familiar GNU Build System, where packages may be
6122 configured, built, and installed with the usual @code{./configure &&
6123 make && make check && make install} command sequence.
6126 The @code{arguments} field specifies options for the build system
6127 (@pxref{Build Systems}). Here it is interpreted by
6128 @var{gnu-build-system} as a request run @file{configure} with the
6129 @option{--enable-silent-rules} flag.
6135 What about these quote (@code{'}) characters? They are Scheme syntax to
6136 introduce a literal list; @code{'} is synonymous with @code{quote}.
6137 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
6138 for details. Here the value of the @code{arguments} field is a list of
6139 arguments passed to the build system down the road, as with @code{apply}
6140 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
6143 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
6144 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
6145 @code{#:configure-flags} is a keyword used to pass a keyword argument
6146 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
6150 The @code{inputs} field specifies inputs to the build process---i.e.,
6151 build-time or run-time dependencies of the package. Here, we define an
6152 input called @code{"gawk"} whose value is that of the @var{gawk}
6153 variable; @var{gawk} is itself bound to a @code{<package>} object.
6155 @cindex backquote (quasiquote)
6158 @cindex comma (unquote)
6162 @findex unquote-splicing
6163 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
6164 us to introduce a literal list in the @code{inputs} field, while
6165 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
6166 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
6169 Note that GCC, Coreutils, Bash, and other essential tools do not need to
6170 be specified as inputs here. Instead, @var{gnu-build-system} takes care
6171 of ensuring that they are present (@pxref{Build Systems}).
6173 However, any other dependencies need to be specified in the
6174 @code{inputs} field. Any dependency not specified here will simply be
6175 unavailable to the build process, possibly leading to a build failure.
6178 @xref{package Reference}, for a full description of possible fields.
6180 Once a package definition is in place, the
6181 package may actually be built using the @code{guix build} command-line
6182 tool (@pxref{Invoking guix build}), troubleshooting any build failures
6183 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
6184 package definition using the @command{guix edit} command
6185 (@pxref{Invoking guix edit}).
6186 @xref{Packaging Guidelines}, for
6187 more information on how to test package definitions, and
6188 @ref{Invoking guix lint}, for information on how to check a definition
6189 for style conformance.
6190 @vindex GUIX_PACKAGE_PATH
6191 Lastly, @pxref{Channels}, for information
6192 on how to extend the distribution by adding your own package definitions
6195 Finally, updating the package definition to a new upstream version
6196 can be partly automated by the @command{guix refresh} command
6197 (@pxref{Invoking guix refresh}).
6199 Behind the scenes, a derivation corresponding to the @code{<package>}
6200 object is first computed by the @code{package-derivation} procedure.
6201 That derivation is stored in a @file{.drv} file under @file{/gnu/store}.
6202 The build actions it prescribes may then be realized by using the
6203 @code{build-derivations} procedure (@pxref{The Store}).
6205 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
6206 Return the @code{<derivation>} object of @var{package} for @var{system}
6207 (@pxref{Derivations}).
6209 @var{package} must be a valid @code{<package>} object, and @var{system}
6210 must be a string denoting the target system type---e.g.,
6211 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
6212 must be a connection to the daemon, which operates on the store
6213 (@pxref{The Store}).
6217 @cindex cross-compilation
6218 Similarly, it is possible to compute a derivation that cross-builds a
6219 package for some other system:
6221 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
6222 @var{package} @var{target} [@var{system}]
6223 Return the @code{<derivation>} object of @var{package} cross-built from
6224 @var{system} to @var{target}.
6226 @var{target} must be a valid GNU triplet denoting the target hardware
6227 and operating system, such as @code{"aarch64-linux-gnu"}
6228 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
6231 @cindex package transformations
6232 @cindex input rewriting
6233 @cindex dependency tree rewriting
6234 Packages can be manipulated in arbitrary ways. An example of a useful
6235 transformation is @dfn{input rewriting}, whereby the dependency tree of
6236 a package is rewritten by replacing specific inputs by others:
6238 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
6239 [@var{rewrite-name}]
6240 Return a procedure that, when passed a package, replaces its direct and
6241 indirect dependencies (but not its implicit inputs) according to
6242 @var{replacements}. @var{replacements} is a list of package pairs; the
6243 first element of each pair is the package to replace, and the second one
6246 Optionally, @var{rewrite-name} is a one-argument procedure that takes
6247 the name of a package and returns its new name after rewrite.
6251 Consider this example:
6254 (define libressl-instead-of-openssl
6255 ;; This is a procedure to replace OPENSSL by LIBRESSL,
6257 (package-input-rewriting `((,openssl . ,libressl))))
6259 (define git-with-libressl
6260 (libressl-instead-of-openssl git))
6264 Here we first define a rewriting procedure that replaces @var{openssl}
6265 with @var{libressl}. Then we use it to define a @dfn{variant} of the
6266 @var{git} package that uses @var{libressl} instead of @var{openssl}.
6267 This is exactly what the @option{--with-input} command-line option does
6268 (@pxref{Package Transformation Options, @option{--with-input}}).
6270 The following variant of @code{package-input-rewriting} can match packages to
6271 be replaced by name rather than by identity.
6273 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
6274 Return a procedure that, given a package, applies the given @var{replacements} to
6275 all the package graph (excluding implicit inputs). @var{replacements} is a list of
6276 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
6277 @code{"guile@@2"}, and each procedure takes a matching package and returns a
6278 replacement for that package.
6281 The example above could be rewritten this way:
6284 (define libressl-instead-of-openssl
6285 ;; Replace all the packages called "openssl" with LibreSSL.
6286 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
6289 The key difference here is that, this time, packages are matched by spec and
6290 not by identity. In other words, any package in the graph that is called
6291 @code{openssl} will be replaced.
6293 A more generic procedure to rewrite a package dependency graph is
6294 @code{package-mapping}: it supports arbitrary changes to nodes in the
6297 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
6298 Return a procedure that, given a package, applies @var{proc} to all the packages
6299 depended on and returns the resulting package. The procedure stops recursion
6300 when @var{cut?} returns true for a given package.
6304 * package Reference:: The package data type.
6305 * origin Reference:: The origin data type.
6309 @node package Reference
6310 @subsection @code{package} Reference
6312 This section summarizes all the options available in @code{package}
6313 declarations (@pxref{Defining Packages}).
6315 @deftp {Data Type} package
6316 This is the data type representing a package recipe.
6320 The name of the package, as a string.
6322 @item @code{version}
6323 The version of the package, as a string.
6326 An object telling how the source code for the package should be
6327 acquired. Most of the time, this is an @code{origin} object, which
6328 denotes a file fetched from the Internet (@pxref{origin Reference}). It
6329 can also be any other ``file-like'' object such as a @code{local-file},
6330 which denotes a file from the local file system (@pxref{G-Expressions,
6331 @code{local-file}}).
6333 @item @code{build-system}
6334 The build system that should be used to build the package (@pxref{Build
6337 @item @code{arguments} (default: @code{'()})
6338 The arguments that should be passed to the build system. This is a
6339 list, typically containing sequential keyword-value pairs.
6341 @item @code{inputs} (default: @code{'()})
6342 @itemx @code{native-inputs} (default: @code{'()})
6343 @itemx @code{propagated-inputs} (default: @code{'()})
6344 @cindex inputs, of packages
6345 These fields list dependencies of the package. Each one is a list of
6346 tuples, where each tuple has a label for the input (a string) as its
6347 first element, a package, origin, or derivation as its second element,
6348 and optionally the name of the output thereof that should be used, which
6349 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
6350 more on package outputs). For example, the list below specifies three
6354 `(("libffi" ,libffi)
6355 ("libunistring" ,libunistring)
6356 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
6359 @cindex cross compilation, package dependencies
6360 The distinction between @code{native-inputs} and @code{inputs} is
6361 necessary when considering cross-compilation. When cross-compiling,
6362 dependencies listed in @code{inputs} are built for the @emph{target}
6363 architecture; conversely, dependencies listed in @code{native-inputs}
6364 are built for the architecture of the @emph{build} machine.
6366 @code{native-inputs} is typically used to list tools needed at
6367 build time, but not at run time, such as Autoconf, Automake, pkg-config,
6368 Gettext, or Bison. @command{guix lint} can report likely mistakes in
6369 this area (@pxref{Invoking guix lint}).
6371 @anchor{package-propagated-inputs}
6372 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
6373 specified packages will be automatically installed alongside the package
6374 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
6375 package}}, for information on how @command{guix package} deals with
6378 For example this is necessary when a C/C++ library needs headers of
6379 another library to compile, or when a pkg-config file refers to another
6380 one @i{via} its @code{Requires} field.
6382 Another example where @code{propagated-inputs} is useful is for languages
6383 that lack a facility to record the run-time search path akin to the
6384 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
6385 more. To ensure that libraries written in those languages can find
6386 library code they depend on at run time, run-time dependencies must be
6387 listed in @code{propagated-inputs} rather than @code{inputs}.
6389 @item @code{outputs} (default: @code{'("out")})
6390 The list of output names of the package. @xref{Packages with Multiple
6391 Outputs}, for typical uses of additional outputs.
6393 @item @code{native-search-paths} (default: @code{'()})
6394 @itemx @code{search-paths} (default: @code{'()})
6395 A list of @code{search-path-specification} objects describing
6396 search-path environment variables honored by the package.
6398 @item @code{replacement} (default: @code{#f})
6399 This must be either @code{#f} or a package object that will be used as a
6400 @dfn{replacement} for this package. @xref{Security Updates, grafts},
6403 @item @code{synopsis}
6404 A one-line description of the package.
6406 @item @code{description}
6407 A more elaborate description of the package.
6409 @item @code{license}
6410 @cindex license, of packages
6411 The license of the package; a value from @code{(guix licenses)},
6412 or a list of such values.
6414 @item @code{home-page}
6415 The URL to the home-page of the package, as a string.
6417 @item @code{supported-systems} (default: @code{%supported-systems})
6418 The list of systems supported by the package, as strings of the form
6419 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
6421 @item @code{location} (default: source location of the @code{package} form)
6422 The source location of the package. It is useful to override this when
6423 inheriting from another package, in which case this field is not
6424 automatically corrected.
6428 @deffn {Scheme Syntax} this-package
6429 When used in the @emph{lexical scope} of a package field definition, this
6430 identifier resolves to the package being defined.
6432 The example below shows how to add a package as a native input of itself when
6440 ;; When cross-compiled, Guile, for example, depends on
6441 ;; a native version of itself. Add it here.
6442 (native-inputs (if (%current-target-system)
6443 `(("self" ,this-package))
6447 It is an error to refer to @code{this-package} outside a package definition.
6450 @node origin Reference
6451 @subsection @code{origin} Reference
6453 This section summarizes all the options available in @code{origin}
6454 declarations (@pxref{Defining Packages}).
6456 @deftp {Data Type} origin
6457 This is the data type representing a source code origin.
6461 An object containing the URI of the source. The object type depends on
6462 the @code{method} (see below). For example, when using the
6463 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
6464 values are: a URL represented as a string, or a list thereof.
6467 A procedure that handles the URI.
6472 @item @var{url-fetch} from @code{(guix download)}
6473 download a file from the HTTP, HTTPS, or FTP URL specified in the
6477 @item @var{git-fetch} from @code{(guix git-download)}
6478 clone the Git version control repository, and check out the revision
6479 specified in the @code{uri} field as a @code{git-reference} object; a
6480 @code{git-reference} looks like this:
6484 (url "https://git.savannah.gnu.org/git/hello.git")
6490 A bytevector containing the SHA-256 hash of the source. This is
6491 equivalent to providing a @code{content-hash} SHA256 object in the
6492 @code{hash} field described below.
6495 The @code{content-hash} object of the source---see below for how to use
6496 @code{content-hash}.
6498 You can obtain this information using @code{guix download}
6499 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
6502 @item @code{file-name} (default: @code{#f})
6503 The file name under which the source code should be saved. When this is
6504 @code{#f}, a sensible default value will be used in most cases. In case
6505 the source is fetched from a URL, the file name from the URL will be
6506 used. For version control checkouts, it is recommended to provide the
6507 file name explicitly because the default is not very descriptive.
6509 @item @code{patches} (default: @code{'()})
6510 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
6511 file-like objects}) pointing to patches to be applied to the source.
6513 This list of patches must be unconditional. In particular, it cannot
6514 depend on the value of @code{%current-system} or
6515 @code{%current-target-system}.
6517 @item @code{snippet} (default: @code{#f})
6518 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
6519 in the source directory. This is a convenient way to modify the source,
6520 sometimes more convenient than a patch.
6522 @item @code{patch-flags} (default: @code{'("-p1")})
6523 A list of command-line flags that should be passed to the @code{patch}
6526 @item @code{patch-inputs} (default: @code{#f})
6527 Input packages or derivations to the patching process. When this is
6528 @code{#f}, the usual set of inputs necessary for patching are provided,
6529 such as GNU@tie{}Patch.
6531 @item @code{modules} (default: @code{'()})
6532 A list of Guile modules that should be loaded during the patching
6533 process and while running the code in the @code{snippet} field.
6535 @item @code{patch-guile} (default: @code{#f})
6536 The Guile package that should be used in the patching process. When
6537 this is @code{#f}, a sensible default is used.
6541 @deftp {Data Type} content-hash @var{value} [@var{algorithm}]
6542 Construct a content hash object for the given @var{algorithm}, and with
6543 @var{value} as its hash value. When @var{algorithm} is omitted, assume
6544 it is @code{sha256}.
6546 @var{value} can be a literal string, in which case it is base32-decoded,
6547 or it can be a bytevector.
6549 The following forms are all equivalent:
6552 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj")
6553 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"
6555 (content-hash (base32
6556 "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"))
6557 (content-hash (base64 "kkb+RPaP7uyMZmu4eXPVkM4BN8yhRd8BTHLslb6f/Rc=")
6561 Technically, @code{content-hash} is currently implemented as a macro.
6562 It performs sanity checks at macro-expansion time, when possible, such
6563 as ensuring that @var{value} has the right size for @var{algorithm}.
6567 @section Build Systems
6569 @cindex build system
6570 Each package definition specifies a @dfn{build system} and arguments for
6571 that build system (@pxref{Defining Packages}). This @code{build-system}
6572 field represents the build procedure of the package, as well as implicit
6573 dependencies of that build procedure.
6575 Build systems are @code{<build-system>} objects. The interface to
6576 create and manipulate them is provided by the @code{(guix build-system)}
6577 module, and actual build systems are exported by specific modules.
6579 @cindex bag (low-level package representation)
6580 Under the hood, build systems first compile package objects to
6581 @dfn{bags}. A @dfn{bag} is like a package, but with less
6582 ornamentation---in other words, a bag is a lower-level representation of
6583 a package, which includes all the inputs of that package, including some
6584 that were implicitly added by the build system. This intermediate
6585 representation is then compiled to a derivation (@pxref{Derivations}).
6587 Build systems accept an optional list of @dfn{arguments}. In package
6588 definitions, these are passed @i{via} the @code{arguments} field
6589 (@pxref{Defining Packages}). They are typically keyword arguments
6590 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
6591 Guile Reference Manual}). The value of these arguments is usually
6592 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
6593 by the daemon (@pxref{Derivations}).
6595 The main build system is @code{gnu-build-system}, which implements the
6596 standard build procedure for GNU and many other packages. It
6597 is provided by the @code{(guix build-system gnu)} module.
6599 @defvr {Scheme Variable} gnu-build-system
6600 @code{gnu-build-system} represents the GNU Build System, and variants
6601 thereof (@pxref{Configuration, configuration and makefile conventions,,
6602 standards, GNU Coding Standards}).
6604 @cindex build phases
6605 In a nutshell, packages using it are configured, built, and installed with
6606 the usual @code{./configure && make && make check && make install}
6607 command sequence. In practice, a few additional steps are often needed.
6608 All these steps are split up in separate @dfn{phases},
6609 notably@footnote{Please see the @code{(guix build gnu-build-system)}
6610 modules for more details about the build phases.}:
6614 Unpack the source tarball, and change the current directory to the
6615 extracted source tree. If the source is actually a directory, copy it
6616 to the build tree, and enter that directory.
6618 @item patch-source-shebangs
6619 Patch shebangs encountered in source files so they refer to the right
6620 store file names. For instance, this changes @code{#!/bin/sh} to
6621 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
6624 Run the @file{configure} script with a number of default options, such
6625 as @option{--prefix=/gnu/store/@dots{}}, as well as the options specified
6626 by the @code{#:configure-flags} argument.
6629 Run @code{make} with the list of flags specified with
6630 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
6631 (the default), build with @code{make -j}.
6634 Run @code{make check}, or some other target specified with
6635 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
6636 @code{#:parallel-tests?} argument is true (the default), run @code{make
6640 Run @code{make install} with the flags listed in @code{#:make-flags}.
6642 @item patch-shebangs
6643 Patch shebangs on the installed executable files.
6646 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
6647 is false), copying them to the @code{debug} output when available
6648 (@pxref{Installing Debugging Files}).
6651 @vindex %standard-phases
6652 The build-side module @code{(guix build gnu-build-system)} defines
6653 @code{%standard-phases} as the default list of build phases.
6654 @code{%standard-phases} is a list of symbol/procedure pairs, where the
6655 procedure implements the actual phase.
6657 The list of phases used for a particular package can be changed with the
6658 @code{#:phases} parameter. For instance, passing:
6661 #:phases (modify-phases %standard-phases (delete 'configure))
6664 means that all the phases described above will be used, except the
6665 @code{configure} phase.
6667 In addition, this build system ensures that the ``standard'' environment
6668 for GNU packages is available. This includes tools such as GCC, libc,
6669 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
6670 build-system gnu)} module for a complete list). We call these the
6671 @dfn{implicit inputs} of a package, because package definitions do not
6672 have to mention them.
6675 Other @code{<build-system>} objects are defined to support other
6676 conventions and tools used by free software packages. They inherit most
6677 of @code{gnu-build-system}, and differ mainly in the set of inputs
6678 implicitly added to the build process, and in the list of phases
6679 executed. Some of these build systems are listed below.
6681 @defvr {Scheme Variable} ant-build-system
6682 This variable is exported by @code{(guix build-system ant)}. It
6683 implements the build procedure for Java packages that can be built with
6684 @url{https://ant.apache.org/, Ant build tool}.
6686 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
6687 provided by the @code{icedtea} package to the set of inputs. Different
6688 packages can be specified with the @code{#:ant} and @code{#:jdk}
6689 parameters, respectively.
6691 When the original package does not provide a suitable Ant build file,
6692 the parameter @code{#:jar-name} can be used to generate a minimal Ant
6693 build file @file{build.xml} with tasks to build the specified jar
6694 archive. In this case the parameter @code{#:source-dir} can be used to
6695 specify the source sub-directory, defaulting to ``src''.
6697 The @code{#:main-class} parameter can be used with the minimal ant
6698 buildfile to specify the main class of the resulting jar. This makes the
6699 jar file executable. The @code{#:test-include} parameter can be used to
6700 specify the list of junit tests to run. It defaults to
6701 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
6702 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
6703 because abstract classes cannot be run as tests.
6705 The parameter @code{#:build-target} can be used to specify the Ant task
6706 that should be run during the @code{build} phase. By default the
6707 ``jar'' task will be run.
6711 @defvr {Scheme Variable} android-ndk-build-system
6712 @cindex Android distribution
6713 @cindex Android NDK build system
6714 This variable is exported by @code{(guix build-system android-ndk)}. It
6715 implements a build procedure for Android NDK (native development kit)
6716 packages using a Guix-specific build process.
6718 The build system assumes that packages install their public interface
6719 (header) files to the subdirectory @file{include} of the @code{out} output and
6720 their libraries to the subdirectory @file{lib} the @code{out} output.
6722 It's also assumed that the union of all the dependencies of a package
6723 has no conflicting files.
6725 For the time being, cross-compilation is not supported - so right now
6726 the libraries and header files are assumed to be host tools.
6730 @defvr {Scheme Variable} asdf-build-system/source
6731 @defvrx {Scheme Variable} asdf-build-system/sbcl
6732 @defvrx {Scheme Variable} asdf-build-system/ecl
6734 These variables, exported by @code{(guix build-system asdf)}, implement
6735 build procedures for Common Lisp packages using
6736 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
6737 definition facility for Common Lisp programs and libraries.
6739 The @code{asdf-build-system/source} system installs the packages in
6740 source form, and can be loaded using any common lisp implementation, via
6741 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
6742 systems in the format which a particular implementation understands.
6743 These build systems can also be used to produce executable programs, or
6744 lisp images which contain a set of packages pre-loaded.
6746 The build system uses naming conventions. For binary packages, the
6747 package name should be prefixed with the lisp implementation, such as
6748 @code{sbcl-} for @code{asdf-build-system/sbcl}.
6750 Additionally, the corresponding source package should be labeled using
6751 the same convention as python packages (see @ref{Python Modules}), using
6752 the @code{cl-} prefix.
6754 For binary packages, each system should be defined as a Guix package.
6755 If one package @code{origin} contains several systems, package variants
6756 can be created in order to build all the systems. Source packages,
6757 which use @code{asdf-build-system/source}, may contain several systems.
6759 In order to create executable programs and images, the build-side
6760 procedures @code{build-program} and @code{build-image} can be used.
6761 They should be called in a build phase after the @code{create-symlinks}
6762 phase, so that the system which was just built can be used within the
6763 resulting image. @code{build-program} requires a list of Common Lisp
6764 expressions to be passed as the @code{#:entry-program} argument.
6766 If the system is not defined within its own @file{.asd} file of the same
6767 name, then the @code{#:asd-file} parameter should be used to specify
6768 which file the system is defined in. Furthermore, if the package
6769 defines a system for its tests in a separate file, it will be loaded
6770 before the tests are run if it is specified by the
6771 @code{#:test-asd-file} parameter. If it is not set, the files
6772 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
6773 and @code{test.asd} will be tried if they exist.
6775 If for some reason the package must be named in a different way than the
6776 naming conventions suggest, the @code{#:asd-system-name} parameter can
6777 be used to specify the name of the system.
6781 @defvr {Scheme Variable} cargo-build-system
6782 @cindex Rust programming language
6783 @cindex Cargo (Rust build system)
6784 This variable is exported by @code{(guix build-system cargo)}. It
6785 supports builds of packages using Cargo, the build tool of the
6786 @uref{https://www.rust-lang.org, Rust programming language}.
6788 It adds @code{rustc} and @code{cargo} to the set of inputs.
6789 A different Rust package can be specified with the @code{#:rust} parameter.
6791 Regular cargo dependencies should be added to the package definition via the
6792 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
6793 spec can be a package or a source definition. Note that the spec must
6794 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
6795 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
6796 should be added to the package definition via the
6797 @code{#:cargo-development-inputs} parameter.
6799 In its @code{configure} phase, this build system will make any source inputs
6800 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
6801 parameters available to cargo. It will also remove an included
6802 @code{Cargo.lock} file to be recreated by @code{cargo} during the
6803 @code{build} phase. The @code{install} phase installs any crate the binaries
6804 if they are defined by the crate.
6808 @defvr {Scheme Variable} copy-build-system
6809 This variable is exported by @code{(guix build-system copy)}. It
6810 supports builds of simple packages that don't require much compiling,
6811 mostly just moving files around.
6813 It adds much of the @code{gnu-build-system} packages to the set of
6814 inputs. Because of this, the @code{copy-build-system} does not require
6815 all the boilerplate code often needed for the
6816 @code{trivial-build-system}.
6818 To further simplify the file installation process, an
6819 @code{#:install-plan} argument is exposed to let the packager specify
6820 which files go where. The install plan is a list of @code{(@var{source}
6821 @var{target} [@var{filters}])}. @var{filters} are optional.
6824 @item When @var{source} matches a file or directory without trailing slash, install it to @var{target}.
6826 @item If @var{target} has a trailing slash, install @var{source} basename beneath @var{target}.
6827 @item Otherwise install @var{source} as @var{target}.
6830 @item When @var{source} is a directory with a trailing slash, or when @var{filters} are used,
6831 the trailing slash of @var{target} is implied with the same meaning
6834 @item Without @var{filters}, install the full @var{source} @emph{content} to @var{target}.
6835 @item With @var{filters} among @code{#:include}, @code{#:include-regexp}, @code{#:exclude},
6836 @code{#:exclude-regexp}, only select files are installed depending on
6837 the filters. Each filters is specified by a list of strings.
6839 @item With @code{#:include}, install all the files which the path suffix matches
6840 at least one of the elements in the given list.
6841 @item With @code{#:include-regexp}, install all the files which the
6842 subpaths match at least one of the regular expressions in the given
6844 @item The @code{#:exclude} and @code{#:exclude-regexp} filters
6845 are the complement of their inclusion counterpart. Without @code{#:include} flags,
6846 install all files but those matching the exclusion filters.
6847 If both inclusions and exclusions are specified, the exclusions are done
6848 on top of the inclusions.
6851 In all cases, the paths relative to @var{source} are preserved within
6858 @item @code{("foo/bar" "share/my-app/")}: Install @file{bar} to @file{share/my-app/bar}.
6859 @item @code{("foo/bar" "share/my-app/baz")}: Install @file{bar} to @file{share/my-app/baz}.
6860 @item @code{("foo/" "share/my-app")}: Install the content of @file{foo} inside @file{share/my-app},
6861 e.g., install @file{foo/sub/file} to @file{share/my-app/sub/file}.
6862 @item @code{("foo/" "share/my-app" #:include ("sub/file"))}: Install only @file{foo/sub/file} to
6863 @file{share/my-app/sub/file}.
6864 @item @code{("foo/sub" "share/my-app" #:include ("file"))}: Install @file{foo/sub/file} to
6865 @file{share/my-app/file}.
6870 @cindex Clojure (programming language)
6871 @cindex simple Clojure build system
6872 @defvr {Scheme Variable} clojure-build-system
6873 This variable is exported by @code{(guix build-system clojure)}. It implements
6874 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
6875 using plain old @code{compile} in Clojure. Cross-compilation is not supported
6878 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
6879 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
6880 @code{#:zip} parameters, respectively.
6882 A list of source directories, test directories and jar names can be specified
6883 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
6884 parameters, respectively. Compile directory and main class can be specified
6885 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
6886 Other parameters are documented below.
6888 This build system is an extension of @code{ant-build-system}, but with the
6889 following phases changed:
6894 This phase calls @code{compile} in Clojure to compile source files and runs
6895 @command{jar} to create jars from both source files and compiled files
6896 according to the include list and exclude list specified in
6897 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
6898 has priority over the include list. These lists consist of symbols
6899 representing Clojure libraries or the special keyword @code{#:all} representing
6900 all Clojure libraries found under the source directories. The parameter
6901 @code{#:omit-source?} decides if source should be included into the jars.
6904 This phase runs tests according to the include list and exclude list specified
6905 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
6906 meanings are analogous to that of @code{#:aot-include} and
6907 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
6908 stands for all Clojure libraries found under the test directories. The
6909 parameter @code{#:tests?} decides if tests should be run.
6912 This phase installs all jars built previously.
6915 Apart from the above, this build system also contains an additional phase:
6920 This phase installs all top-level files with base name matching
6921 @code{%doc-regex}. A different regex can be specified with the
6922 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
6923 directories specified in @code{#:doc-dirs} are installed as well.
6927 @defvr {Scheme Variable} cmake-build-system
6928 This variable is exported by @code{(guix build-system cmake)}. It
6929 implements the build procedure for packages using the
6930 @url{https://www.cmake.org, CMake build tool}.
6932 It automatically adds the @code{cmake} package to the set of inputs.
6933 Which package is used can be specified with the @code{#:cmake}
6936 The @code{#:configure-flags} parameter is taken as a list of flags
6937 passed to the @command{cmake} command. The @code{#:build-type}
6938 parameter specifies in abstract terms the flags passed to the compiler;
6939 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
6940 debugging information''), which roughly means that code is compiled with
6941 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
6944 @defvr {Scheme Variable} dune-build-system
6945 This variable is exported by @code{(guix build-system dune)}. It
6946 supports builds of packages using @uref{https://dune.build/, Dune}, a build
6947 tool for the OCaml programming language. It is implemented as an extension
6948 of the @code{ocaml-build-system} which is described below. As such, the
6949 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
6952 It automatically adds the @code{dune} package to the set of inputs.
6953 Which package is used can be specified with the @code{#:dune}
6956 There is no @code{configure} phase because dune packages typically don't
6957 need to be configured. The @code{#:build-flags} parameter is taken as a
6958 list of flags passed to the @code{dune} command during the build.
6960 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
6961 command instead of the more recent @code{dune} command while building
6962 a package. Its default value is @code{#f}.
6964 The @code{#:package} parameter can be passed to specify a package name, which
6965 is useful when a package contains multiple packages and you want to build
6966 only one of them. This is equivalent to passing the @code{-p} argument to
6970 @defvr {Scheme Variable} go-build-system
6971 This variable is exported by @code{(guix build-system go)}. It
6972 implements a build procedure for Go packages using the standard
6973 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
6974 Go build mechanisms}.
6976 The user is expected to provide a value for the key @code{#:import-path}
6977 and, in some cases, @code{#:unpack-path}. The
6978 @url{https://golang.org/doc/code.html#ImportPaths, import path}
6979 corresponds to the file system path expected by the package's build
6980 scripts and any referring packages, and provides a unique way to
6981 refer to a Go package. It is typically based on a combination of the
6982 package source code's remote URI and file system hierarchy structure. In
6983 some cases, you will need to unpack the package's source code to a
6984 different directory structure than the one indicated by the import path,
6985 and @code{#:unpack-path} should be used in such cases.
6987 Packages that provide Go libraries should install their source code into
6988 the built output. The key @code{#:install-source?}, which defaults to
6989 @code{#t}, controls whether or not the source code is installed. It can
6990 be set to @code{#f} for packages that only provide executable files.
6993 @defvr {Scheme Variable} glib-or-gtk-build-system
6994 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
6995 is intended for use with packages making use of GLib or GTK+.
6997 This build system adds the following two phases to the ones defined by
6998 @code{gnu-build-system}:
7001 @item glib-or-gtk-wrap
7002 The phase @code{glib-or-gtk-wrap} ensures that programs in
7003 @file{bin/} are able to find GLib ``schemas'' and
7004 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
7005 modules}. This is achieved by wrapping the programs in launch scripts
7006 that appropriately set the @env{XDG_DATA_DIRS} and @env{GTK_PATH}
7007 environment variables.
7009 It is possible to exclude specific package outputs from that wrapping
7010 process by listing their names in the
7011 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
7012 when an output is known not to contain any GLib or GTK+ binaries, and
7013 where wrapping would gratuitously add a dependency of that output on
7016 @item glib-or-gtk-compile-schemas
7017 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
7018 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
7019 GSettings schemas} of GLib are compiled. Compilation is performed by the
7020 @command{glib-compile-schemas} program. It is provided by the package
7021 @code{glib:bin} which is automatically imported by the build system.
7022 The @code{glib} package providing @command{glib-compile-schemas} can be
7023 specified with the @code{#:glib} parameter.
7026 Both phases are executed after the @code{install} phase.
7029 @defvr {Scheme Variable} guile-build-system
7030 This build system is for Guile packages that consist exclusively of Scheme
7031 code and that are so lean that they don't even have a makefile, let alone a
7032 @file{configure} script. It compiles Scheme code using @command{guild
7033 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
7034 installs the @file{.scm} and @file{.go} files in the right place. It also
7035 installs documentation.
7037 This build system supports cross-compilation by using the
7038 @option{--target} option of @samp{guild compile}.
7040 Packages built with @code{guile-build-system} must provide a Guile package in
7041 their @code{native-inputs} field.
7044 @defvr {Scheme Variable} julia-build-system
7045 This variable is exported by @code{(guix build-system julia)}. It
7046 implements the build procedure used by @uref{https://julialang.org/,
7047 julia} packages, which essentially is similar to running @samp{julia -e
7048 'using Pkg; Pkg.add(package)'} in an environment where
7049 @env{JULIA_LOAD_PATH} contains the paths to all Julia package inputs.
7050 Tests are run not run.
7052 Julia packages require the source @code{file-name} to be the real name of the
7053 package, correctly capitalized.
7055 For packages requiring shared library dependencies, you may need to write the
7056 @file{/deps/deps.jl} file manually. It's usually a line of @code{const
7057 variable = /gnu/store/library.so} for each dependency, plus a void function
7058 @code{check_deps() = nothing}.
7060 Some older packages that aren't using @file{Package.toml} yet, will require
7061 this file to be created, too. The function @code{julia-create-package-toml}
7062 helps creating the file. You need to pass the outputs and the source of the
7063 package, it's name (the same as the @code{file-name} parameter), the package
7064 uuid, the package version, and a list of dependencies specified by their name
7068 @defvr {Scheme Variable} maven-build-system
7069 This variable is exported by @code{(guix build-system maven)}. It implements
7070 a build procedure for @uref{https://maven.apache.org, Maven} packages. Maven
7071 is a dependency and lifecycle management tool for Java. A user of Maven
7072 specifies dependencies and plugins in a @file{pom.xml} file that Maven reads.
7073 When Maven does not have one of the dependencies or plugins in its repository,
7074 it will download them and use them to build the package.
7076 The maven build system ensures that maven will not try to download any
7077 dependency by running in offline mode. Maven will fail if a dependency is
7078 missing. Before running Maven, the @file{pom.xml} (and subprojects) are
7079 modified to specify the version of dependencies and plugins that match the
7080 versions available in the guix build environment. Dependencies and plugins
7081 must be installed in the fake maven repository at @file{lib/m2}, and are
7082 symlinked into a proper repository before maven is run. Maven is instructed
7083 to use that repository for the build and installs built artifacts there.
7084 Changed files are copied to the @file{lib/m2} directory of the package output.
7086 You can specify a @file{pom.xml} file with the @code{#:pom-file} argument,
7087 or let the build system use the default @file{pom.xml} file in the sources.
7089 In case you need to specify a dependency's version manually, you can use the
7090 @code{#:local-packages} argument. It takes an association list where the key
7091 is the groupId of the package and its value is an association list where the
7092 key is the artifactId of the package and its value is the version you want to
7093 override in the @file{pom.xml}.
7095 Some packages use dependencies or plugins that are not useful at runtime nor
7096 at build time in Guix. You can alter the @file{pom.xml} file to remove them
7097 using the @code{#:exclude} argument. Its value is an association list where
7098 the key is the groupId of the plugin or dependency you want to remove, and
7099 the value is a list of artifactId you want to remove.
7101 You can override the default @code{jdk} and @code{maven} packages with the
7102 corresponding argument, @code{#:jdk} and @code{#:maven}.
7104 The @code{#:maven-plugins} argument is a list of maven plugins used during
7105 the build, with the same format as the @code{inputs} fields of the package
7106 declaration. Its default value is @code{(default-maven-plugins)} which is
7110 @defvr {Scheme Variable} minify-build-system
7111 This variable is exported by @code{(guix build-system minify)}. It
7112 implements a minification procedure for simple JavaScript packages.
7114 It adds @code{uglify-js} to the set of inputs and uses it to compress
7115 all JavaScript files in the @file{src} directory. A different minifier
7116 package can be specified with the @code{#:uglify-js} parameter, but it
7117 is expected that the package writes the minified code to the standard
7120 When the input JavaScript files are not all located in the @file{src}
7121 directory, the parameter @code{#:javascript-files} can be used to
7122 specify a list of file names to feed to the minifier.
7125 @defvr {Scheme Variable} ocaml-build-system
7126 This variable is exported by @code{(guix build-system ocaml)}. It implements
7127 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
7128 of choosing the correct set of commands to run for each package. OCaml
7129 packages can expect many different commands to be run. This build system will
7132 When the package has a @file{setup.ml} file present at the top-level, it will
7133 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
7134 @code{ocaml setup.ml -install}. The build system will assume that this file
7135 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
7136 care of setting the prefix and enabling tests if they are not disabled. You
7137 can pass configure and build flags with the @code{#:configure-flags} and
7138 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
7139 set of flags used to enable tests. The @code{#:use-make?} key can be used to
7140 bypass this system in the build and install phases.
7142 When the package has a @file{configure} file, it is assumed that it is a
7143 hand-made configure script that requires a different argument format than
7144 in the @code{gnu-build-system}. You can add more flags with the
7145 @code{#:configure-flags} key.
7147 When the package has a @file{Makefile} file (or @code{#:use-make?} is
7148 @code{#t}), it will be used and more flags can be passed to the build and
7149 install phases with the @code{#:make-flags} key.
7151 Finally, some packages do not have these files and use a somewhat standard
7152 location for its build system. In that case, the build system will run
7153 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
7154 providing the path to the required findlib module. Additional flags can
7155 be passed via the @code{#:build-flags} key. Install is taken care of by
7156 @command{opam-installer}. In this case, the @code{opam} package must
7157 be added to the @code{native-inputs} field of the package definition.
7159 Note that most OCaml packages assume they will be installed in the same
7160 directory as OCaml, which is not what we want in guix. In particular, they
7161 will install @file{.so} files in their module's directory, which is usually
7162 fine because it is in the OCaml compiler directory. In guix though, these
7163 libraries cannot be found and we use @env{CAML_LD_LIBRARY_PATH}. This
7164 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
7165 @file{.so} libraries should be installed.
7168 @defvr {Scheme Variable} python-build-system
7169 This variable is exported by @code{(guix build-system python)}. It
7170 implements the more or less standard build procedure used by Python
7171 packages, which consists in running @code{python setup.py build} and
7172 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
7174 For packages that install stand-alone Python programs under @code{bin/},
7175 it takes care of wrapping these programs so that their @env{PYTHONPATH}
7176 environment variable points to all the Python libraries they depend on.
7178 Which Python package is used to perform the build can be specified with
7179 the @code{#:python} parameter. This is a useful way to force a package
7180 to be built for a specific version of the Python interpreter, which
7181 might be necessary if the package is only compatible with a single
7182 interpreter version.
7184 By default guix calls @code{setup.py} under control of
7185 @code{setuptools}, much like @command{pip} does. Some packages are not
7186 compatible with setuptools (and pip), thus you can disable this by
7187 setting the @code{#:use-setuptools?} parameter to @code{#f}.
7190 @defvr {Scheme Variable} perl-build-system
7191 This variable is exported by @code{(guix build-system perl)}. It
7192 implements the standard build procedure for Perl packages, which either
7193 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
7194 followed by @code{Build} and @code{Build install}; or in running
7195 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
7196 @code{make} and @code{make install}, depending on which of
7197 @code{Build.PL} or @code{Makefile.PL} is present in the package
7198 distribution. Preference is given to the former if both @code{Build.PL}
7199 and @code{Makefile.PL} exist in the package distribution. This
7200 preference can be reversed by specifying @code{#t} for the
7201 @code{#:make-maker?} parameter.
7203 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
7204 passes flags specified by the @code{#:make-maker-flags} or
7205 @code{#:module-build-flags} parameter, respectively.
7207 Which Perl package is used can be specified with @code{#:perl}.
7210 @defvr {Scheme Variable} qt-build-system
7211 This variable is exported by @code{(guix build-system qt)}. It
7212 is intended for use with applications using Qt or KDE.
7214 This build system adds the following two phases to the ones defined by
7215 @code{cmake-build-system}:
7219 The phase @code{check-setup} prepares the environment for running
7220 the checks as commonly used by Qt test programs.
7221 For now this only sets some environment variables:
7222 @code{QT_QPA_PLATFORM=offscreen},
7223 @code{DBUS_FATAL_WARNINGS=0} and
7224 @code{CTEST_OUTPUT_ON_FAILURE=1}.
7226 This phase is added before the @code{check} phase.
7227 It's a separate phase to ease adjusting if necessary.
7230 The phase @code{qt-wrap}
7231 searches for Qt5 plugin paths, QML paths and some XDG in the inputs
7232 and output. In case some path is found, all programs in the output's
7233 @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
7234 are wrapped in scripts defining the necessary environment variables.
7236 It is possible to exclude specific package outputs from that wrapping process
7237 by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
7238 This is useful when an output is known not to contain any Qt binaries, and
7239 where wrapping would gratuitously add a dependency of that output on Qt, KDE,
7242 This phase is added after the @code{install} phase.
7246 @defvr {Scheme Variable} r-build-system
7247 This variable is exported by @code{(guix build-system r)}. It
7248 implements the build procedure used by @uref{https://r-project.org, R}
7249 packages, which essentially is little more than running @samp{R CMD
7250 INSTALL --library=/gnu/store/@dots{}} in an environment where
7251 @env{R_LIBS_SITE} contains the paths to all R package inputs. Tests are
7252 run after installation using the R function
7253 @code{tools::testInstalledPackage}.
7256 @defvr {Scheme Variable} rakudo-build-system
7257 This variable is exported by @code{(guix build-system rakudo)}. It
7258 implements the build procedure used by @uref{https://rakudo.org/,
7259 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
7260 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
7261 installs the binaries, library files and the resources, as well as wrap
7262 the files under the @code{bin/} directory. Tests can be skipped by
7263 passing @code{#f} to the @code{tests?} parameter.
7265 Which rakudo package is used can be specified with @code{rakudo}.
7266 Which perl6-tap-harness package used for the tests can be specified with
7267 @code{#:prove6} or removed by passing @code{#f} to the
7268 @code{with-prove6?} parameter.
7269 Which perl6-zef package used for tests and installing can be specified
7270 with @code{#:zef} or removed by passing @code{#f} to the
7271 @code{with-zef?} parameter.
7274 @defvr {Scheme Variable} texlive-build-system
7275 This variable is exported by @code{(guix build-system texlive)}. It is
7276 used to build TeX packages in batch mode with a specified engine. The
7277 build system sets the @env{TEXINPUTS} variable to find all TeX source
7278 files in the inputs.
7280 By default it runs @code{luatex} on all files ending on @code{ins}. A
7281 different engine and format can be specified with the
7282 @code{#:tex-format} argument. Different build targets can be specified
7283 with the @code{#:build-targets} argument, which expects a list of file
7284 names. The build system adds only @code{texlive-bin} and
7285 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
7286 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
7287 and @code{#:texlive-latex-base}, respectively.
7289 The @code{#:tex-directory} parameter tells the build system where to
7290 install the built files under the texmf tree.
7293 @defvr {Scheme Variable} ruby-build-system
7294 This variable is exported by @code{(guix build-system ruby)}. It
7295 implements the RubyGems build procedure used by Ruby packages, which
7296 involves running @code{gem build} followed by @code{gem install}.
7298 The @code{source} field of a package that uses this build system
7299 typically references a gem archive, since this is the format that Ruby
7300 developers use when releasing their software. The build system unpacks
7301 the gem archive, potentially patches the source, runs the test suite,
7302 repackages the gem, and installs it. Additionally, directories and
7303 tarballs may be referenced to allow building unreleased gems from Git or
7304 a traditional source release tarball.
7306 Which Ruby package is used can be specified with the @code{#:ruby}
7307 parameter. A list of additional flags to be passed to the @command{gem}
7308 command can be specified with the @code{#:gem-flags} parameter.
7311 @defvr {Scheme Variable} waf-build-system
7312 This variable is exported by @code{(guix build-system waf)}. It
7313 implements a build procedure around the @code{waf} script. The common
7314 phases---@code{configure}, @code{build}, and @code{install}---are
7315 implemented by passing their names as arguments to the @code{waf}
7318 The @code{waf} script is executed by the Python interpreter. Which
7319 Python package is used to run the script can be specified with the
7320 @code{#:python} parameter.
7323 @defvr {Scheme Variable} scons-build-system
7324 This variable is exported by @code{(guix build-system scons)}. It
7325 implements the build procedure used by the SCons software construction
7326 tool. This build system runs @code{scons} to build the package,
7327 @code{scons test} to run tests, and then @code{scons install} to install
7330 Additional flags to be passed to @code{scons} can be specified with the
7331 @code{#:scons-flags} parameter. The default build and install targets
7332 can be overridden with @code{#:build-targets} and
7333 @code{#:install-targets} respectively. The version of Python used to
7334 run SCons can be specified by selecting the appropriate SCons package
7335 with the @code{#:scons} parameter.
7338 @defvr {Scheme Variable} haskell-build-system
7339 This variable is exported by @code{(guix build-system haskell)}. It
7340 implements the Cabal build procedure used by Haskell packages, which
7341 involves running @code{runhaskell Setup.hs configure
7342 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
7343 Instead of installing the package by running @code{runhaskell Setup.hs
7344 install}, to avoid trying to register libraries in the read-only
7345 compiler store directory, the build system uses @code{runhaskell
7346 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
7347 addition, the build system generates the package documentation by
7348 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
7349 is passed. Optional Haddock parameters can be passed with the help of
7350 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
7351 not found, the build system looks for @code{Setup.lhs} instead.
7353 Which Haskell compiler is used can be specified with the @code{#:haskell}
7354 parameter which defaults to @code{ghc}.
7357 @defvr {Scheme Variable} dub-build-system
7358 This variable is exported by @code{(guix build-system dub)}. It
7359 implements the Dub build procedure used by D packages, which
7360 involves running @code{dub build} and @code{dub run}.
7361 Installation is done by copying the files manually.
7363 Which D compiler is used can be specified with the @code{#:ldc}
7364 parameter which defaults to @code{ldc}.
7367 @defvr {Scheme Variable} emacs-build-system
7368 This variable is exported by @code{(guix build-system emacs)}. It
7369 implements an installation procedure similar to the packaging system
7370 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
7372 It first creates the @code{@code{package}-autoloads.el} file, then it
7373 byte compiles all Emacs Lisp files. Differently from the Emacs
7374 packaging system, the Info documentation files are moved to the standard
7375 documentation directory and the @file{dir} file is deleted. The Elisp
7376 package files are installed directly under @file{share/emacs/site-lisp}.
7379 @defvr {Scheme Variable} font-build-system
7380 This variable is exported by @code{(guix build-system font)}. It
7381 implements an installation procedure for font packages where upstream
7382 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
7383 need to be copied into place. It copies font files to standard
7384 locations in the output directory.
7387 @defvr {Scheme Variable} meson-build-system
7388 This variable is exported by @code{(guix build-system meson)}. It
7389 implements the build procedure for packages that use
7390 @url{https://mesonbuild.com, Meson} as their build system.
7392 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
7393 of inputs, and they can be changed with the parameters @code{#:meson}
7394 and @code{#:ninja} if needed. The default Meson is
7395 @code{meson-for-build}, which is special because it doesn't clear the
7396 @code{RUNPATH} of binaries and libraries when they are installed.
7398 This build system is an extension of @code{gnu-build-system}, but with the
7399 following phases changed to some specific for Meson:
7404 The phase runs @code{meson} with the flags specified in
7405 @code{#:configure-flags}. The flag @option{--buildtype} is always set to
7406 @code{debugoptimized} unless something else is specified in
7407 @code{#:build-type}.
7410 The phase runs @code{ninja} to build the package in parallel by default, but
7411 this can be changed with @code{#:parallel-build?}.
7414 The phase runs @code{ninja} with the target specified in @code{#:test-target},
7415 which is @code{"test"} by default.
7418 The phase runs @code{ninja install} and can not be changed.
7421 Apart from that, the build system also adds the following phases:
7426 This phase ensures that all binaries can find the libraries they need.
7427 It searches for required libraries in subdirectories of the package being
7428 built, and adds those to @code{RUNPATH} where needed. It also removes
7429 references to libraries left over from the build phase by
7430 @code{meson-for-build}, such as test dependencies, that aren't actually
7431 required for the program to run.
7433 @item glib-or-gtk-wrap
7434 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
7435 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
7437 @item glib-or-gtk-compile-schemas
7438 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
7439 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
7443 @defvr {Scheme Variable} linux-module-build-system
7444 @code{linux-module-build-system} allows building Linux kernel modules.
7446 @cindex build phases
7447 This build system is an extension of @code{gnu-build-system}, but with the
7448 following phases changed:
7453 This phase configures the environment so that the Linux kernel's Makefile
7454 can be used to build the external kernel module.
7457 This phase uses the Linux kernel's Makefile in order to build the external
7461 This phase uses the Linux kernel's Makefile in order to install the external
7465 It is possible and useful to specify the Linux kernel to use for building
7466 the module (in the @code{arguments} form of a package using the
7467 @code{linux-module-build-system}, use the key @code{#:linux} to specify it).
7470 @defvr {Scheme Variable} node-build-system
7471 This variable is exported by @code{(guix build-system node)}. It
7472 implements the build procedure used by @uref{https://nodejs.org,
7473 Node.js}, which implements an approximation of the @code{npm install}
7474 command, followed by an @code{npm test} command.
7476 Which Node.js package is used to interpret the @code{npm} commands can
7477 be specified with the @code{#:node} parameter which defaults to
7481 Lastly, for packages that do not need anything as sophisticated, a
7482 ``trivial'' build system is provided. It is trivial in the sense that
7483 it provides basically no support: it does not pull any implicit inputs,
7484 and does not have a notion of build phases.
7486 @defvr {Scheme Variable} trivial-build-system
7487 This variable is exported by @code{(guix build-system trivial)}.
7489 This build system requires a @code{#:builder} argument. This argument
7490 must be a Scheme expression that builds the package output(s)---as
7491 with @code{build-expression->derivation} (@pxref{Derivations,
7492 @code{build-expression->derivation}}).
7502 Conceptually, the @dfn{store} is the place where derivations that have
7503 been built successfully are stored---by default, @file{/gnu/store}.
7504 Sub-directories in the store are referred to as @dfn{store items} or
7505 sometimes @dfn{store paths}. The store has an associated database that
7506 contains information such as the store paths referred to by each store
7507 path, and the list of @emph{valid} store items---results of successful
7508 builds. This database resides in @file{@var{localstatedir}/guix/db},
7509 where @var{localstatedir} is the state directory specified @i{via}
7510 @option{--localstatedir} at configure time, usually @file{/var}.
7512 The store is @emph{always} accessed by the daemon on behalf of its clients
7513 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
7514 connect to the daemon over a Unix-domain socket, send requests to it,
7515 and read the result---these are remote procedure calls, or RPCs.
7518 Users must @emph{never} modify files under @file{/gnu/store} directly.
7519 This would lead to inconsistencies and break the immutability
7520 assumptions of Guix's functional model (@pxref{Introduction}).
7522 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
7523 how to check the integrity of the store and attempt recovery from
7524 accidental modifications.
7527 The @code{(guix store)} module provides procedures to connect to the
7528 daemon, and to perform RPCs. These are described below. By default,
7529 @code{open-connection}, and thus all the @command{guix} commands,
7530 connect to the local daemon or to the URI specified by the
7531 @env{GUIX_DAEMON_SOCKET} environment variable.
7533 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
7534 When set, the value of this variable should be a file name or a URI
7535 designating the daemon endpoint. When it is a file name, it denotes a
7536 Unix-domain socket to connect to. In addition to file names, the
7537 supported URI schemes are:
7542 These are for Unix-domain sockets.
7543 @code{file:///var/guix/daemon-socket/socket} is equivalent to
7544 @file{/var/guix/daemon-socket/socket}.
7547 @cindex daemon, remote access
7548 @cindex remote access to the daemon
7549 @cindex daemon, cluster setup
7550 @cindex clusters, daemon setup
7551 These URIs denote connections over TCP/IP, without encryption nor
7552 authentication of the remote host. The URI must specify the host name
7553 and optionally a port number (by default port 44146 is used):
7556 guix://master.guix.example.org:1234
7559 This setup is suitable on local networks, such as clusters, where only
7560 trusted nodes may connect to the build daemon at
7561 @code{master.guix.example.org}.
7563 The @option{--listen} option of @command{guix-daemon} can be used to
7564 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
7565 @option{--listen}}).
7568 @cindex SSH access to build daemons
7569 These URIs allow you to connect to a remote daemon over SSH. This
7570 feature requires Guile-SSH (@pxref{Requirements}) and a working
7571 @command{guile} binary in @env{PATH} on the destination machine. It
7572 supports public key and GSSAPI authentication. A typical URL might look
7576 ssh://charlie@@guix.example.org:22
7579 As for @command{guix copy}, the usual OpenSSH client configuration files
7580 are honored (@pxref{Invoking guix copy}).
7583 Additional URI schemes may be supported in the future.
7585 @c XXX: Remove this note when the protocol incurs fewer round trips
7586 @c and when (guix derivations) no longer relies on file system access.
7588 The ability to connect to remote build daemons is considered
7589 experimental as of @value{VERSION}. Please get in touch with us to
7590 share any problems or suggestions you may have (@pxref{Contributing}).
7594 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
7595 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
7596 @var{reserve-space?} is true, instruct it to reserve a little bit of
7597 extra space on the file system so that the garbage collector can still
7598 operate should the disk become full. Return a server object.
7600 @var{file} defaults to @code{%default-socket-path}, which is the normal
7601 location given the options that were passed to @command{configure}.
7604 @deffn {Scheme Procedure} close-connection @var{server}
7605 Close the connection to @var{server}.
7608 @defvr {Scheme Variable} current-build-output-port
7609 This variable is bound to a SRFI-39 parameter, which refers to the port
7610 where build and error logs sent by the daemon should be written.
7613 Procedures that make RPCs all take a server object as their first
7616 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
7617 @cindex invalid store items
7618 Return @code{#t} when @var{path} designates a valid store item and
7619 @code{#f} otherwise (an invalid item may exist on disk but still be
7620 invalid, for instance because it is the result of an aborted or failed
7623 A @code{&store-protocol-error} condition is raised if @var{path} is not
7624 prefixed by the store directory (@file{/gnu/store}).
7627 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
7628 Add @var{text} under file @var{name} in the store, and return its store
7629 path. @var{references} is the list of store paths referred to by the
7630 resulting store path.
7633 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
7635 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
7636 file names, or derivation/output pairs, using the specified
7637 @var{mode}---@code{(build-mode normal)} by default.
7640 Note that the @code{(guix monads)} module provides a monad as well as
7641 monadic versions of the above procedures, with the goal of making it
7642 more convenient to work with code that accesses the store (@pxref{The
7646 @i{This section is currently incomplete.}
7649 @section Derivations
7652 Low-level build actions and the environment in which they are performed
7653 are represented by @dfn{derivations}. A derivation contains the
7654 following pieces of information:
7658 The outputs of the derivation---derivations produce at least one file or
7659 directory in the store, but may produce more.
7662 @cindex build-time dependencies
7663 @cindex dependencies, build-time
7664 The inputs of the derivations---i.e., its build-time dependencies---which may
7665 be other derivations or plain files in the store (patches, build scripts,
7669 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
7672 The file name of a build script in the store, along with the arguments
7676 A list of environment variables to be defined.
7680 @cindex derivation path
7681 Derivations allow clients of the daemon to communicate build actions to
7682 the store. They exist in two forms: as an in-memory representation,
7683 both on the client- and daemon-side, and as files in the store whose
7684 name end in @file{.drv}---these files are referred to as @dfn{derivation
7685 paths}. Derivations paths can be passed to the @code{build-derivations}
7686 procedure to perform the build actions they prescribe (@pxref{The
7689 @cindex fixed-output derivations
7690 Operations such as file downloads and version-control checkouts for
7691 which the expected content hash is known in advance are modeled as
7692 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
7693 of a fixed-output derivation are independent of its inputs---e.g., a
7694 source code download produces the same result regardless of the download
7695 method and tools being used.
7698 @cindex run-time dependencies
7699 @cindex dependencies, run-time
7700 The outputs of derivations---i.e., the build results---have a set of
7701 @dfn{references}, as reported by the @code{references} RPC or the
7702 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
7703 are the set of run-time dependencies of the build results. References are a
7704 subset of the inputs of the derivation; this subset is automatically computed
7705 by the build daemon by scanning all the files in the outputs.
7707 The @code{(guix derivations)} module provides a representation of
7708 derivations as Scheme objects, along with procedures to create and
7709 otherwise manipulate derivations. The lowest-level primitive to create
7710 a derivation is the @code{derivation} procedure:
7712 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
7713 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
7714 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
7715 [#:system (%current-system)] [#:references-graphs #f] @
7716 [#:allowed-references #f] [#:disallowed-references #f] @
7717 [#:leaked-env-vars #f] [#:local-build? #f] @
7718 [#:substitutable? #t] [#:properties '()]
7719 Build a derivation with the given arguments, and return the resulting
7720 @code{<derivation>} object.
7722 When @var{hash} and @var{hash-algo} are given, a
7723 @dfn{fixed-output derivation} is created---i.e., one whose result is
7724 known in advance, such as a file download. If, in addition,
7725 @var{recursive?} is true, then that fixed output may be an executable
7726 file or a directory and @var{hash} must be the hash of an archive
7727 containing this output.
7729 When @var{references-graphs} is true, it must be a list of file
7730 name/store path pairs. In that case, the reference graph of each store
7731 path is exported in the build environment in the corresponding file, in
7732 a simple text format.
7734 When @var{allowed-references} is true, it must be a list of store items
7735 or outputs that the derivation's output may refer to. Likewise,
7736 @var{disallowed-references}, if true, must be a list of things the
7737 outputs may @emph{not} refer to.
7739 When @var{leaked-env-vars} is true, it must be a list of strings
7740 denoting environment variables that are allowed to ``leak'' from the
7741 daemon's environment to the build environment. This is only applicable
7742 to fixed-output derivations---i.e., when @var{hash} is true. The main
7743 use is to allow variables such as @code{http_proxy} to be passed to
7744 derivations that download files.
7746 When @var{local-build?} is true, declare that the derivation is not a
7747 good candidate for offloading and should rather be built locally
7748 (@pxref{Daemon Offload Setup}). This is the case for small derivations
7749 where the costs of data transfers would outweigh the benefits.
7751 When @var{substitutable?} is false, declare that substitutes of the
7752 derivation's output should not be used (@pxref{Substitutes}). This is
7753 useful, for instance, when building packages that capture details of the
7754 host CPU instruction set.
7756 @var{properties} must be an association list describing ``properties'' of the
7757 derivation. It is kept as-is, uninterpreted, in the derivation.
7761 Here's an example with a shell script as its builder, assuming
7762 @var{store} is an open connection to the daemon, and @var{bash} points
7763 to a Bash executable in the store:
7766 (use-modules (guix utils)
7770 (let ((builder ; add the Bash script to the store
7771 (add-text-to-store store "my-builder.sh"
7772 "echo hello world > $out\n" '())))
7773 (derivation store "foo"
7774 bash `("-e" ,builder)
7775 #:inputs `((,bash) (,builder))
7776 #:env-vars '(("HOME" . "/homeless"))))
7777 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
7780 As can be guessed, this primitive is cumbersome to use directly. A
7781 better approach is to write build scripts in Scheme, of course! The
7782 best course of action for that is to write the build code as a
7783 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
7784 information, @pxref{G-Expressions}.
7786 Once upon a time, @code{gexp->derivation} did not exist and constructing
7787 derivations with build code written in Scheme was achieved with
7788 @code{build-expression->derivation}, documented below. This procedure
7789 is now deprecated in favor of the much nicer @code{gexp->derivation}.
7791 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
7792 @var{name} @var{exp} @
7793 [#:system (%current-system)] [#:inputs '()] @
7794 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
7795 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7796 [#:references-graphs #f] [#:allowed-references #f] @
7797 [#:disallowed-references #f] @
7798 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
7799 Return a derivation that executes Scheme expression @var{exp} as a
7800 builder for derivation @var{name}. @var{inputs} must be a list of
7801 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
7802 @code{"out"} is assumed. @var{modules} is a list of names of Guile
7803 modules from the current search path to be copied in the store,
7804 compiled, and made available in the load path during the execution of
7805 @var{exp}---e.g., @code{((guix build utils) (guix build
7806 gnu-build-system))}.
7808 @var{exp} is evaluated in an environment where @code{%outputs} is bound
7809 to a list of output/path pairs, and where @code{%build-inputs} is bound
7810 to a list of string/output-path pairs made from @var{inputs}.
7811 Optionally, @var{env-vars} is a list of string pairs specifying the name
7812 and value of environment variables visible to the builder. The builder
7813 terminates by passing the result of @var{exp} to @code{exit}; thus, when
7814 @var{exp} returns @code{#f}, the build is considered to have failed.
7816 @var{exp} is built using @var{guile-for-build} (a derivation). When
7817 @var{guile-for-build} is omitted or is @code{#f}, the value of the
7818 @code{%guile-for-build} fluid is used instead.
7820 See the @code{derivation} procedure for the meaning of
7821 @var{references-graphs}, @var{allowed-references},
7822 @var{disallowed-references}, @var{local-build?}, and
7823 @var{substitutable?}.
7827 Here's an example of a single-output derivation that creates a directory
7828 containing one file:
7831 (let ((builder '(let ((out (assoc-ref %outputs "out")))
7832 (mkdir out) ; create /gnu/store/@dots{}-goo
7833 (call-with-output-file (string-append out "/test")
7835 (display '(hello guix) p))))))
7836 (build-expression->derivation store "goo" builder))
7838 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
7842 @node The Store Monad
7843 @section The Store Monad
7847 The procedures that operate on the store described in the previous
7848 sections all take an open connection to the build daemon as their first
7849 argument. Although the underlying model is functional, they either have
7850 side effects or depend on the current state of the store.
7852 The former is inconvenient: the connection to the build daemon has to be
7853 carried around in all those functions, making it impossible to compose
7854 functions that do not take that parameter with functions that do. The
7855 latter can be problematic: since store operations have side effects
7856 and/or depend on external state, they have to be properly sequenced.
7858 @cindex monadic values
7859 @cindex monadic functions
7860 This is where the @code{(guix monads)} module comes in. This module
7861 provides a framework for working with @dfn{monads}, and a particularly
7862 useful monad for our uses, the @dfn{store monad}. Monads are a
7863 construct that allows two things: associating ``context'' with values
7864 (in our case, the context is the store), and building sequences of
7865 computations (here computations include accesses to the store). Values
7866 in a monad---values that carry this additional context---are called
7867 @dfn{monadic values}; procedures that return such values are called
7868 @dfn{monadic procedures}.
7870 Consider this ``normal'' procedure:
7873 (define (sh-symlink store)
7874 ;; Return a derivation that symlinks the 'bash' executable.
7875 (let* ((drv (package-derivation store bash))
7876 (out (derivation->output-path drv))
7877 (sh (string-append out "/bin/bash")))
7878 (build-expression->derivation store "sh"
7879 `(symlink ,sh %output))))
7882 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
7883 as a monadic function:
7886 (define (sh-symlink)
7887 ;; Same, but return a monadic value.
7888 (mlet %store-monad ((drv (package->derivation bash)))
7889 (gexp->derivation "sh"
7890 #~(symlink (string-append #$drv "/bin/bash")
7894 There are several things to note in the second version: the @code{store}
7895 parameter is now implicit and is ``threaded'' in the calls to the
7896 @code{package->derivation} and @code{gexp->derivation} monadic
7897 procedures, and the monadic value returned by @code{package->derivation}
7898 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
7900 As it turns out, the call to @code{package->derivation} can even be
7901 omitted since it will take place implicitly, as we will see later
7902 (@pxref{G-Expressions}):
7905 (define (sh-symlink)
7906 (gexp->derivation "sh"
7907 #~(symlink (string-append #$bash "/bin/bash")
7912 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
7913 @c for the funny quote.
7914 Calling the monadic @code{sh-symlink} has no effect. As someone once
7915 said, ``you exit a monad like you exit a building on fire: by running''.
7916 So, to exit the monad and get the desired effect, one must use
7917 @code{run-with-store}:
7920 (run-with-store (open-connection) (sh-symlink))
7921 @result{} /gnu/store/...-sh-symlink
7924 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
7925 new ``meta-commands'' to make it easier to deal with monadic procedures:
7926 @code{run-in-store}, and @code{enter-store-monad}. The former is used
7927 to ``run'' a single monadic value through the store:
7930 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
7931 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7934 The latter enters a recursive REPL, where all the return values are
7935 automatically run through the store:
7938 scheme@@(guile-user)> ,enter-store-monad
7939 store-monad@@(guile-user) [1]> (package->derivation hello)
7940 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7941 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
7942 $3 = "/gnu/store/@dots{}-foo"
7943 store-monad@@(guile-user) [1]> ,q
7944 scheme@@(guile-user)>
7948 Note that non-monadic values cannot be returned in the
7949 @code{store-monad} REPL.
7951 The main syntactic forms to deal with monads in general are provided by
7952 the @code{(guix monads)} module and are described below.
7954 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
7955 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
7959 @deffn {Scheme Syntax} return @var{val}
7960 Return a monadic value that encapsulates @var{val}.
7963 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
7964 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
7965 procedures @var{mproc}@dots{}@footnote{This operation is commonly
7966 referred to as ``bind'', but that name denotes an unrelated procedure in
7967 Guile. Thus we use this somewhat cryptic symbol inherited from the
7968 Haskell language.}. There can be one @var{mproc} or several of them, as
7973 (with-monad %state-monad
7975 (lambda (x) (return (+ 1 x)))
7976 (lambda (x) (return (* 2 x)))))
7980 @result{} some-state
7984 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
7986 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
7988 Bind the variables @var{var} to the monadic values @var{mval} in
7989 @var{body}, which is a sequence of expressions. As with the bind
7990 operator, this can be thought of as ``unpacking'' the raw, non-monadic
7991 value ``contained'' in @var{mval} and making @var{var} refer to that
7992 raw, non-monadic value within the scope of the @var{body}. The form
7993 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
7994 @var{val}, as per @code{let}. The binding operations occur in sequence
7995 from left to right. The last expression of @var{body} must be a monadic
7996 expression, and its result will become the result of the @code{mlet} or
7997 @code{mlet*} when run in the @var{monad}.
7999 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
8000 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
8003 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
8004 Bind @var{mexp} and the following monadic expressions in sequence,
8005 returning the result of the last expression. Every expression in the
8006 sequence must be a monadic expression.
8008 This is akin to @code{mlet}, except that the return values of the
8009 monadic expressions are ignored. In that sense, it is analogous to
8010 @code{begin}, but applied to monadic expressions.
8013 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
8014 When @var{condition} is true, evaluate the sequence of monadic
8015 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
8016 @var{condition} is false, return @code{*unspecified*} in the current
8017 monad. Every expression in the sequence must be a monadic expression.
8020 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
8021 When @var{condition} is false, evaluate the sequence of monadic
8022 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
8023 @var{condition} is true, return @code{*unspecified*} in the current
8024 monad. Every expression in the sequence must be a monadic expression.
8028 The @code{(guix monads)} module provides the @dfn{state monad}, which
8029 allows an additional value---the state---to be @emph{threaded} through
8030 monadic procedure calls.
8032 @defvr {Scheme Variable} %state-monad
8033 The state monad. Procedures in the state monad can access and change
8034 the state that is threaded.
8036 Consider the example below. The @code{square} procedure returns a value
8037 in the state monad. It returns the square of its argument, but also
8038 increments the current state value:
8042 (mlet %state-monad ((count (current-state)))
8043 (mbegin %state-monad
8044 (set-current-state (+ 1 count))
8047 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
8052 When ``run'' through @code{%state-monad}, we obtain that additional state
8053 value, which is the number of @code{square} calls.
8056 @deffn {Monadic Procedure} current-state
8057 Return the current state as a monadic value.
8060 @deffn {Monadic Procedure} set-current-state @var{value}
8061 Set the current state to @var{value} and return the previous state as a
8065 @deffn {Monadic Procedure} state-push @var{value}
8066 Push @var{value} to the current state, which is assumed to be a list,
8067 and return the previous state as a monadic value.
8070 @deffn {Monadic Procedure} state-pop
8071 Pop a value from the current state and return it as a monadic value.
8072 The state is assumed to be a list.
8075 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
8076 Run monadic value @var{mval} starting with @var{state} as the initial
8077 state. Return two values: the resulting value, and the resulting state.
8080 The main interface to the store monad, provided by the @code{(guix
8081 store)} module, is as follows.
8083 @defvr {Scheme Variable} %store-monad
8084 The store monad---an alias for @code{%state-monad}.
8086 Values in the store monad encapsulate accesses to the store. When its
8087 effect is needed, a value of the store monad must be ``evaluated'' by
8088 passing it to the @code{run-with-store} procedure (see below).
8091 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
8092 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
8093 open store connection.
8096 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
8097 Return as a monadic value the absolute file name in the store of the file
8098 containing @var{text}, a string. @var{references} is a list of store items that the
8099 resulting text file refers to; it defaults to the empty list.
8102 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
8103 Return as a monadic value the absolute file name in the store of the file
8104 containing @var{data}, a bytevector. @var{references} is a list of store
8105 items that the resulting binary file refers to; it defaults to the empty list.
8108 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
8109 [#:recursive? #t] [#:select? (const #t)]
8110 Return the name of @var{file} once interned in the store. Use
8111 @var{name} as its store name, or the basename of @var{file} if
8112 @var{name} is omitted.
8114 When @var{recursive?} is true, the contents of @var{file} are added
8115 recursively; if @var{file} designates a flat file and @var{recursive?}
8116 is true, its contents are added, and its permission bits are kept.
8118 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
8119 @var{stat})} for each directory entry, where @var{file} is the entry's
8120 absolute file name and @var{stat} is the result of @code{lstat}; exclude
8121 entries for which @var{select?} does not return true.
8123 The example below adds a file to the store, under two different names:
8126 (run-with-store (open-connection)
8127 (mlet %store-monad ((a (interned-file "README"))
8128 (b (interned-file "README" "LEGU-MIN")))
8129 (return (list a b))))
8131 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
8136 The @code{(guix packages)} module exports the following package-related
8139 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
8140 [#:system (%current-system)] [#:target #f] @
8143 value in the absolute file name of @var{file} within the @var{output}
8144 directory of @var{package}. When @var{file} is omitted, return the name
8145 of the @var{output} directory of @var{package}. When @var{target} is
8146 true, use it as a cross-compilation target triplet.
8148 Note that this procedure does @emph{not} build @var{package}. Thus, the
8149 result might or might not designate an existing file. We recommend not
8150 using this procedure unless you know what you are doing.
8153 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
8154 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
8155 @var{target} [@var{system}]
8156 Monadic version of @code{package-derivation} and
8157 @code{package-cross-derivation} (@pxref{Defining Packages}).
8162 @section G-Expressions
8164 @cindex G-expression
8165 @cindex build code quoting
8166 So we have ``derivations'', which represent a sequence of build actions
8167 to be performed to produce an item in the store (@pxref{Derivations}).
8168 These build actions are performed when asking the daemon to actually
8169 build the derivations; they are run by the daemon in a container
8170 (@pxref{Invoking guix-daemon}).
8172 @cindex strata of code
8173 It should come as no surprise that we like to write these build actions
8174 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
8175 code@footnote{The term @dfn{stratum} in this context was coined by
8176 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
8177 Kiselyov, who has written insightful
8178 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
8179 on this topic}, refers to this kind of code generation as
8180 @dfn{staging}.}: the ``host code''---code that defines packages, talks
8181 to the daemon, etc.---and the ``build code''---code that actually
8182 performs build actions, such as making directories, invoking
8183 @command{make}, etc.
8185 To describe a derivation and its build actions, one typically needs to
8186 embed build code inside host code. It boils down to manipulating build
8187 code as data, and the homoiconicity of Scheme---code has a direct
8188 representation as data---comes in handy for that. But we need more than
8189 the normal @code{quasiquote} mechanism in Scheme to construct build
8192 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
8193 S-expressions adapted to build expressions. G-expressions, or
8194 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
8195 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
8196 @code{#$}, and @code{#$@@}), which are comparable to
8197 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
8198 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
8199 GNU Guile Reference Manual}). However, there are major differences:
8203 Gexps are meant to be written to a file and run or manipulated by other
8207 When a high-level object such as a package or derivation is unquoted
8208 inside a gexp, the result is as if its output file name had been
8212 Gexps carry information about the packages or derivations they refer to,
8213 and these dependencies are automatically added as inputs to the build
8214 processes that use them.
8217 @cindex lowering, of high-level objects in gexps
8218 This mechanism is not limited to package and derivation
8219 objects: @dfn{compilers} able to ``lower'' other high-level objects to
8220 derivations or files in the store can be defined,
8221 such that these objects can also be inserted
8222 into gexps. For example, a useful type of high-level objects that can be
8223 inserted in a gexp is ``file-like objects'', which make it easy to
8224 add files to the store and to refer to them in
8225 derivations and such (see @code{local-file} and @code{plain-file}
8228 To illustrate the idea, here is an example of a gexp:
8235 (symlink (string-append #$coreutils "/bin/ls")
8239 This gexp can be passed to @code{gexp->derivation}; we obtain a
8240 derivation that builds a directory containing exactly one symlink to
8241 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
8244 (gexp->derivation "the-thing" build-exp)
8247 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
8248 substituted to the reference to the @var{coreutils} package in the
8249 actual build code, and @var{coreutils} is automatically made an input to
8250 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
8251 output)}) is replaced by a string containing the directory name of the
8252 output of the derivation.
8254 @cindex cross compilation
8255 In a cross-compilation context, it is useful to distinguish between
8256 references to the @emph{native} build of a package---that can run on the
8257 host---versus references to cross builds of a package. To that end, the
8258 @code{#+} plays the same role as @code{#$}, but is a reference to a
8259 native package build:
8262 (gexp->derivation "vi"
8265 (mkdir (string-append #$output "/bin"))
8266 (system* (string-append #+coreutils "/bin/ln")
8268 (string-append #$emacs "/bin/emacs")
8269 (string-append #$output "/bin/vi")))
8270 #:target "aarch64-linux-gnu")
8274 In the example above, the native build of @var{coreutils} is used, so
8275 that @command{ln} can actually run on the host; but then the
8276 cross-compiled build of @var{emacs} is referenced.
8278 @cindex imported modules, for gexps
8279 @findex with-imported-modules
8280 Another gexp feature is @dfn{imported modules}: sometimes you want to be
8281 able to use certain Guile modules from the ``host environment'' in the
8282 gexp, so those modules should be imported in the ``build environment''.
8283 The @code{with-imported-modules} form allows you to express that:
8286 (let ((build (with-imported-modules '((guix build utils))
8288 (use-modules (guix build utils))
8289 (mkdir-p (string-append #$output "/bin"))))))
8290 (gexp->derivation "empty-dir"
8293 (display "success!\n")
8298 In this example, the @code{(guix build utils)} module is automatically
8299 pulled into the isolated build environment of our gexp, such that
8300 @code{(use-modules (guix build utils))} works as expected.
8302 @cindex module closure
8303 @findex source-module-closure
8304 Usually you want the @emph{closure} of the module to be imported---i.e.,
8305 the module itself and all the modules it depends on---rather than just
8306 the module; failing to do that, attempts to use the module will fail
8307 because of missing dependent modules. The @code{source-module-closure}
8308 procedure computes the closure of a module by looking at its source file
8309 headers, which comes in handy in this case:
8312 (use-modules (guix modules)) ;for 'source-module-closure'
8314 (with-imported-modules (source-module-closure
8315 '((guix build utils)
8317 (gexp->derivation "something-with-vms"
8319 (use-modules (guix build utils)
8324 @cindex extensions, for gexps
8325 @findex with-extensions
8326 In the same vein, sometimes you want to import not just pure-Scheme
8327 modules, but also ``extensions'' such as Guile bindings to C libraries
8328 or other ``full-blown'' packages. Say you need the @code{guile-json}
8329 package available on the build side, here's how you would do it:
8332 (use-modules (gnu packages guile)) ;for 'guile-json'
8334 (with-extensions (list guile-json)
8335 (gexp->derivation "something-with-json"
8337 (use-modules (json))
8341 The syntactic form to construct gexps is summarized below.
8343 @deffn {Scheme Syntax} #~@var{exp}
8344 @deffnx {Scheme Syntax} (gexp @var{exp})
8345 Return a G-expression containing @var{exp}. @var{exp} may contain one
8346 or more of the following forms:
8350 @itemx (ungexp @var{obj})
8351 Introduce a reference to @var{obj}. @var{obj} may have one of the
8352 supported types, for example a package or a
8353 derivation, in which case the @code{ungexp} form is replaced by its
8354 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
8356 If @var{obj} is a list, it is traversed and references to supported
8357 objects are substituted similarly.
8359 If @var{obj} is another gexp, its contents are inserted and its
8360 dependencies are added to those of the containing gexp.
8362 If @var{obj} is another kind of object, it is inserted as is.
8364 @item #$@var{obj}:@var{output}
8365 @itemx (ungexp @var{obj} @var{output})
8366 This is like the form above, but referring explicitly to the
8367 @var{output} of @var{obj}---this is useful when @var{obj} produces
8368 multiple outputs (@pxref{Packages with Multiple Outputs}).
8371 @itemx #+@var{obj}:output
8372 @itemx (ungexp-native @var{obj})
8373 @itemx (ungexp-native @var{obj} @var{output})
8374 Same as @code{ungexp}, but produces a reference to the @emph{native}
8375 build of @var{obj} when used in a cross compilation context.
8377 @item #$output[:@var{output}]
8378 @itemx (ungexp output [@var{output}])
8379 Insert a reference to derivation output @var{output}, or to the main
8380 output when @var{output} is omitted.
8382 This only makes sense for gexps passed to @code{gexp->derivation}.
8385 @itemx (ungexp-splicing @var{lst})
8386 Like the above, but splices the contents of @var{lst} inside the
8390 @itemx (ungexp-native-splicing @var{lst})
8391 Like the above, but refers to native builds of the objects listed in
8396 G-expressions created by @code{gexp} or @code{#~} are run-time objects
8397 of the @code{gexp?} type (see below).
8400 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
8401 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
8402 in their execution environment.
8404 Each item in @var{modules} can be the name of a module, such as
8405 @code{(guix build utils)}, or it can be a module name, followed by an
8406 arrow, followed by a file-like object:
8409 `((guix build utils)
8411 ((guix config) => ,(scheme-file "config.scm"
8412 #~(define-module @dots{}))))
8416 In the example above, the first two modules are taken from the search
8417 path, and the last one is created from the given file-like object.
8419 This form has @emph{lexical} scope: it has an effect on the gexps
8420 directly defined in @var{body}@dots{}, but not on those defined, say, in
8421 procedures called from @var{body}@dots{}.
8424 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
8425 Mark the gexps defined in @var{body}@dots{} as requiring
8426 @var{extensions} in their build and execution environment.
8427 @var{extensions} is typically a list of package objects such as those
8428 defined in the @code{(gnu packages guile)} module.
8430 Concretely, the packages listed in @var{extensions} are added to the
8431 load path while compiling imported modules in @var{body}@dots{}; they
8432 are also added to the load path of the gexp returned by
8436 @deffn {Scheme Procedure} gexp? @var{obj}
8437 Return @code{#t} if @var{obj} is a G-expression.
8440 G-expressions are meant to be written to disk, either as code building
8441 some derivation, or as plain files in the store. The monadic procedures
8442 below allow you to do that (@pxref{The Store Monad}, for more
8443 information about monads).
8445 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
8446 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
8447 [#:hash #f] [#:hash-algo #f] @
8448 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
8449 [#:module-path @code{%load-path}] @
8450 [#:effective-version "2.2"] @
8451 [#:references-graphs #f] [#:allowed-references #f] @
8452 [#:disallowed-references #f] @
8453 [#:leaked-env-vars #f] @
8454 [#:script-name (string-append @var{name} "-builder")] @
8455 [#:deprecation-warnings #f] @
8456 [#:local-build? #f] [#:substitutable? #t] @
8457 [#:properties '()] [#:guile-for-build #f]
8458 Return a derivation @var{name} that runs @var{exp} (a gexp) with
8459 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
8460 stored in a file called @var{script-name}. When @var{target} is true,
8461 it is used as the cross-compilation target triplet for packages referred
8464 @var{modules} is deprecated in favor of @code{with-imported-modules}.
8466 make @var{modules} available in the evaluation context of @var{exp};
8467 @var{modules} is a list of names of Guile modules searched in
8468 @var{module-path} to be copied in the store, compiled, and made available in
8469 the load path during the execution of @var{exp}---e.g., @code{((guix
8470 build utils) (guix build gnu-build-system))}.
8472 @var{effective-version} determines the string to use when adding extensions of
8473 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
8475 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
8478 When @var{references-graphs} is true, it must be a list of tuples of one of the
8482 (@var{file-name} @var{package})
8483 (@var{file-name} @var{package} @var{output})
8484 (@var{file-name} @var{derivation})
8485 (@var{file-name} @var{derivation} @var{output})
8486 (@var{file-name} @var{store-item})
8489 The right-hand-side of each element of @var{references-graphs} is automatically made
8490 an input of the build process of @var{exp}. In the build environment, each
8491 @var{file-name} contains the reference graph of the corresponding item, in a simple
8494 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
8495 In the latter case, the list denotes store items that the result is allowed to
8496 refer to. Any reference to another store item will lead to a build error.
8497 Similarly for @var{disallowed-references}, which can list items that must not be
8498 referenced by the outputs.
8500 @var{deprecation-warnings} determines whether to show deprecation warnings while
8501 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
8503 The other arguments are as for @code{derivation} (@pxref{Derivations}).
8506 @cindex file-like objects
8507 The @code{local-file}, @code{plain-file}, @code{computed-file},
8508 @code{program-file}, and @code{scheme-file} procedures below return
8509 @dfn{file-like objects}. That is, when unquoted in a G-expression,
8510 these objects lead to a file in the store. Consider this G-expression:
8513 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
8514 #$(local-file "/tmp/my-nscd.conf"))
8517 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
8518 to the store. Once expanded, for instance @i{via}
8519 @code{gexp->derivation}, the G-expression refers to that copy under
8520 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
8521 does not have any effect on what the G-expression does.
8522 @code{plain-file} can be used similarly; it differs in that the file
8523 content is directly passed as a string.
8525 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
8526 [#:recursive? #f] [#:select? (const #t)]
8527 Return an object representing local file @var{file} to add to the store;
8528 this object can be used in a gexp. If @var{file} is a literal string
8529 denoting a relative file name, it is looked up relative to the source
8530 file where it appears; if @var{file} is not a literal string, it is
8531 looked up relative to the current working directory at run time.
8532 @var{file} will be added to the store under @var{name}--by default the
8533 base name of @var{file}.
8535 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
8536 designates a flat file and @var{recursive?} is true, its contents are added, and its
8537 permission bits are kept.
8539 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
8540 @var{stat})} for each directory entry, where @var{file} is the entry's
8541 absolute file name and @var{stat} is the result of @code{lstat}; exclude
8542 entries for which @var{select?} does not return true.
8544 This is the declarative counterpart of the @code{interned-file} monadic
8545 procedure (@pxref{The Store Monad, @code{interned-file}}).
8548 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
8549 Return an object representing a text file called @var{name} with the given
8550 @var{content} (a string or a bytevector) to be added to the store.
8552 This is the declarative counterpart of @code{text-file}.
8555 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
8558 Return an object representing the store item @var{name}, a file or
8559 directory computed by @var{gexp}. When @var{local-build?} is true (the
8560 default), the derivation is built locally. @var{options} is a list of
8561 additional arguments to pass to @code{gexp->derivation}.
8563 This is the declarative counterpart of @code{gexp->derivation}.
8566 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
8567 [#:guile (default-guile)] [#:module-path %load-path] @
8568 [#:system (%current-system)] [#:target #f]
8569 Return an executable script @var{name} that runs @var{exp} using
8570 @var{guile}, with @var{exp}'s imported modules in its search path.
8571 Look up @var{exp}'s modules in @var{module-path}.
8573 The example below builds a script that simply invokes the @command{ls}
8577 (use-modules (guix gexp) (gnu packages base))
8579 (gexp->script "list-files"
8580 #~(execl #$(file-append coreutils "/bin/ls")
8584 When ``running'' it through the store (@pxref{The Store Monad,
8585 @code{run-with-store}}), we obtain a derivation that produces an
8586 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
8589 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
8591 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
8595 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
8596 [#:guile #f] [#:module-path %load-path]
8597 Return an object representing the executable store item @var{name} that
8598 runs @var{gexp}. @var{guile} is the Guile package used to execute that
8599 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
8601 This is the declarative counterpart of @code{gexp->script}.
8604 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
8605 [#:set-load-path? #t] [#:module-path %load-path] @
8607 [#:guile (default-guile)]
8608 Return a derivation that builds a file @var{name} containing @var{exp}.
8609 When @var{splice?} is true, @var{exp} is considered to be a list of
8610 expressions that will be spliced in the resulting file.
8612 When @var{set-load-path?} is true, emit code in the resulting file to
8613 set @code{%load-path} and @code{%load-compiled-path} to honor
8614 @var{exp}'s imported modules. Look up @var{exp}'s modules in
8617 The resulting file holds references to all the dependencies of @var{exp}
8618 or a subset thereof.
8621 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} @
8622 [#:splice? #f] [#:set-load-path? #t]
8623 Return an object representing the Scheme file @var{name} that contains
8626 This is the declarative counterpart of @code{gexp->file}.
8629 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
8630 Return as a monadic value a derivation that builds a text file
8631 containing all of @var{text}. @var{text} may list, in addition to
8632 strings, objects of any type that can be used in a gexp: packages,
8633 derivations, local file objects, etc. The resulting store file holds
8634 references to all these.
8636 This variant should be preferred over @code{text-file} anytime the file
8637 to create will reference items from the store. This is typically the
8638 case when building a configuration file that embeds store file names,
8642 (define (profile.sh)
8643 ;; Return the name of a shell script in the store that
8644 ;; initializes the 'PATH' environment variable.
8645 (text-file* "profile.sh"
8646 "export PATH=" coreutils "/bin:"
8647 grep "/bin:" sed "/bin\n"))
8650 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
8651 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
8652 preventing them from being garbage-collected during its lifetime.
8655 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
8656 Return an object representing store file @var{name} containing
8657 @var{text}. @var{text} is a sequence of strings and file-like objects,
8661 (mixed-text-file "profile"
8662 "export PATH=" coreutils "/bin:" grep "/bin")
8665 This is the declarative counterpart of @code{text-file*}.
8668 @deffn {Scheme Procedure} file-union @var{name} @var{files}
8669 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
8670 Each item in @var{files} must be a two-element list where the first element is the
8671 file name to use in the new directory, and the second element is a gexp
8672 denoting the target file. Here's an example:
8676 `(("hosts" ,(plain-file "hosts"
8677 "127.0.0.1 localhost"))
8678 ("bashrc" ,(plain-file "bashrc"
8679 "alias ls='ls --color=auto'"))))
8682 This yields an @code{etc} directory containing these two files.
8685 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
8686 Return a directory that is the union of @var{things}, where @var{things} is a list of
8687 file-like objects denoting directories. For example:
8690 (directory-union "guile+emacs" (list guile emacs))
8693 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
8696 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
8697 Return a file-like object that expands to the concatenation of @var{obj}
8698 and @var{suffix}, where @var{obj} is a lowerable object and each
8699 @var{suffix} is a string.
8701 As an example, consider this gexp:
8704 (gexp->script "run-uname"
8705 #~(system* #$(file-append coreutils
8709 The same effect could be achieved with:
8712 (gexp->script "run-uname"
8713 #~(system* (string-append #$coreutils
8717 There is one difference though: in the @code{file-append} case, the
8718 resulting script contains the absolute file name as a string, whereas in
8719 the second case, the resulting script contains a @code{(string-append
8720 @dots{})} expression to construct the file name @emph{at run time}.
8723 @deffn {Scheme Syntax} let-system @var{system} @var{body}@dots{}
8724 @deffnx {Scheme Syntax} let-system (@var{system} @var{target}) @var{body}@dots{}
8725 Bind @var{system} to the currently targeted system---e.g.,
8726 @code{"x86_64-linux"}---within @var{body}.
8728 In the second case, additionally bind @var{target} to the current
8729 cross-compilation target---a GNU triplet such as
8730 @code{"arm-linux-gnueabihf"}---or @code{#f} if we are not
8733 @code{let-system} is useful in the occasional case where the object
8734 spliced into the gexp depends on the target system, as in this example:
8738 #+(let-system system
8739 (cond ((string-prefix? "armhf-" system)
8740 (file-append qemu "/bin/qemu-system-arm"))
8741 ((string-prefix? "x86_64-" system)
8742 (file-append qemu "/bin/qemu-system-x86_64"))
8745 "-net" "user" #$image)
8749 @deffn {Scheme Syntax} with-parameters ((@var{parameter} @var{value}) @dots{}) @var{exp}
8750 This macro is similar to the @code{parameterize} form for
8751 dynamically-bound @dfn{parameters} (@pxref{Parameters,,, guile, GNU
8752 Guile Reference Manual}). The key difference is that it takes effect
8753 when the file-like object returned by @var{exp} is lowered to a
8754 derivation or store item.
8756 A typical use of @code{with-parameters} is to force the system in effect
8760 (with-parameters ((%current-system "i686-linux"))
8764 The example above returns an object that corresponds to the i686 build
8765 of Coreutils, regardless of the current value of @code{%current-system}.
8769 Of course, in addition to gexps embedded in ``host'' code, there are
8770 also modules containing build tools. To make it clear that they are
8771 meant to be used in the build stratum, these modules are kept in the
8772 @code{(guix build @dots{})} name space.
8774 @cindex lowering, of high-level objects in gexps
8775 Internally, high-level objects are @dfn{lowered}, using their compiler,
8776 to either derivations or store items. For instance, lowering a package
8777 yields a derivation, and lowering a @code{plain-file} yields a store
8778 item. This is achieved using the @code{lower-object} monadic procedure.
8780 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
8782 Return as a value in @code{%store-monad} the derivation or store item
8783 corresponding to @var{obj} for @var{system}, cross-compiling for
8784 @var{target} if @var{target} is true. @var{obj} must be an object that
8785 has an associated gexp compiler, such as a @code{<package>}.
8788 @node Invoking guix repl
8789 @section Invoking @command{guix repl}
8791 @cindex REPL, read-eval-print loop, script
8792 The @command{guix repl} command makes it easier to program Guix in Guile
8793 by launching a Guile @dfn{read-eval-print loop} (REPL) for interactive
8794 programming (@pxref{Using Guile Interactively,,, guile,
8795 GNU Guile Reference Manual}), or by running Guile scripts
8796 (@pxref{Running Guile Scripts,,, guile,
8797 GNU Guile Reference Manual}).
8798 Compared to just launching the @command{guile}
8799 command, @command{guix repl} guarantees that all the Guix modules and all its
8800 dependencies are available in the search path.
8802 The general syntax is:
8805 guix repl @var{options} [@var{file} @var{args}]
8808 When a @var{file} argument is provided, @var{file} is
8809 executed as a Guile scripts:
8812 guix repl my-script.scm
8815 To pass arguments to the script, use @code{--} to prevent them from
8816 being interpreted as arguments to @command{guix repl} itself:
8819 guix repl -- my-script.scm --input=foo.txt
8822 To make a script executable directly from the shell, using the guix
8823 executable that is on the user's search path, add the following two
8824 lines at the top of the script:
8827 @code{#!/usr/bin/env -S guix repl --}
8831 Without a file name argument, a Guile REPL is started:
8835 scheme@@(guile-user)> ,use (gnu packages base)
8836 scheme@@(guile-user)> coreutils
8837 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
8841 In addition, @command{guix repl} implements a simple machine-readable REPL
8842 protocol for use by @code{(guix inferior)}, a facility to interact with
8843 @dfn{inferiors}, separate processes running a potentially different revision
8846 The available options are as follows:
8849 @item --type=@var{type}
8850 @itemx -t @var{type}
8851 Start a REPL of the given @var{TYPE}, which can be one of the following:
8855 This is default, and it spawns a standard full-featured Guile REPL.
8857 Spawn a REPL that uses the machine-readable protocol. This is the protocol
8858 that the @code{(guix inferior)} module speaks.
8861 @item --listen=@var{endpoint}
8862 By default, @command{guix repl} reads from standard input and writes to
8863 standard output. When this option is passed, it will instead listen for
8864 connections on @var{endpoint}. Here are examples of valid options:
8867 @item --listen=tcp:37146
8868 Accept connections on localhost on port 37146.
8870 @item --listen=unix:/tmp/socket
8871 Accept connections on the Unix-domain socket @file{/tmp/socket}.
8874 @item --load-path=@var{directory}
8875 @itemx -L @var{directory}
8876 Add @var{directory} to the front of the package module search path
8877 (@pxref{Package Modules}).
8879 This allows users to define their own packages and make them visible to
8883 Inhibit loading of the @file{~/.guile} file. By default, that
8884 configuration file is loaded when spawning a @code{guile} REPL.
8887 @c *********************************************************************
8891 This section describes Guix command-line utilities. Some of them are
8892 primarily targeted at developers and users who write new package
8893 definitions, while others are more generally useful. They complement
8894 the Scheme programming interface of Guix in a convenient way.
8897 * Invoking guix build:: Building packages from the command line.
8898 * Invoking guix edit:: Editing package definitions.
8899 * Invoking guix download:: Downloading a file and printing its hash.
8900 * Invoking guix hash:: Computing the cryptographic hash of a file.
8901 * Invoking guix import:: Importing package definitions.
8902 * Invoking guix refresh:: Updating package definitions.
8903 * Invoking guix lint:: Finding errors in package definitions.
8904 * Invoking guix size:: Profiling disk usage.
8905 * Invoking guix graph:: Visualizing the graph of packages.
8906 * Invoking guix publish:: Sharing substitutes.
8907 * Invoking guix challenge:: Challenging substitute servers.
8908 * Invoking guix copy:: Copying to and from a remote store.
8909 * Invoking guix container:: Process isolation.
8910 * Invoking guix weather:: Assessing substitute availability.
8911 * Invoking guix processes:: Listing client processes.
8914 @node Invoking guix build
8915 @section Invoking @command{guix build}
8917 @cindex package building
8918 @cindex @command{guix build}
8919 The @command{guix build} command builds packages or derivations and
8920 their dependencies, and prints the resulting store paths. Note that it
8921 does not modify the user's profile---this is the job of the
8922 @command{guix package} command (@pxref{Invoking guix package}). Thus,
8923 it is mainly useful for distribution developers.
8925 The general syntax is:
8928 guix build @var{options} @var{package-or-derivation}@dots{}
8931 As an example, the following command builds the latest versions of Emacs
8932 and of Guile, displays their build logs, and finally displays the
8933 resulting directories:
8936 guix build emacs guile
8939 Similarly, the following command builds all the available packages:
8942 guix build --quiet --keep-going \
8943 `guix package -A | cut -f1,2 --output-delimiter=@@`
8946 @var{package-or-derivation} may be either the name of a package found in
8947 the software distribution such as @code{coreutils} or
8948 @code{coreutils@@8.20}, or a derivation such as
8949 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
8950 package with the corresponding name (and optionally version) is searched
8951 for among the GNU distribution modules (@pxref{Package Modules}).
8953 Alternatively, the @option{--expression} option may be used to specify a
8954 Scheme expression that evaluates to a package; this is useful when
8955 disambiguating among several same-named packages or package variants is
8958 There may be zero or more @var{options}. The available options are
8959 described in the subsections below.
8962 * Common Build Options:: Build options for most commands.
8963 * Package Transformation Options:: Creating variants of packages.
8964 * Additional Build Options:: Options specific to 'guix build'.
8965 * Debugging Build Failures:: Real life packaging experience.
8968 @node Common Build Options
8969 @subsection Common Build Options
8971 A number of options that control the build process are common to
8972 @command{guix build} and other commands that can spawn builds, such as
8973 @command{guix package} or @command{guix archive}. These are the
8978 @item --load-path=@var{directory}
8979 @itemx -L @var{directory}
8980 Add @var{directory} to the front of the package module search path
8981 (@pxref{Package Modules}).
8983 This allows users to define their own packages and make them visible to
8984 the command-line tools.
8988 Keep the build tree of failed builds. Thus, if a build fails, its build
8989 tree is kept under @file{/tmp}, in a directory whose name is shown at
8990 the end of the build log. This is useful when debugging build issues.
8991 @xref{Debugging Build Failures}, for tips and tricks on how to debug
8994 This option implies @option{--no-offload}, and it has no effect when
8995 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
8996 Store, the @env{GUIX_DAEMON_SOCKET} variable}).
9000 Keep going when some of the derivations fail to build; return only once
9001 all the builds have either completed or failed.
9003 The default behavior is to stop as soon as one of the specified
9004 derivations has failed.
9008 Do not build the derivations.
9010 @anchor{fallback-option}
9012 When substituting a pre-built binary fails, fall back to building
9013 packages locally (@pxref{Substitution Failure}).
9015 @item --substitute-urls=@var{urls}
9016 @anchor{client-substitute-urls}
9017 Consider @var{urls} the whitespace-separated list of substitute source
9018 URLs, overriding the default list of URLs of @command{guix-daemon}
9019 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
9021 This means that substitutes may be downloaded from @var{urls}, provided
9022 they are signed by a key authorized by the system administrator
9023 (@pxref{Substitutes}).
9025 When @var{urls} is the empty string, substitutes are effectively
9028 @item --no-substitutes
9029 Do not use substitutes for build products. That is, always build things
9030 locally instead of allowing downloads of pre-built binaries
9031 (@pxref{Substitutes}).
9034 Do not ``graft'' packages. In practice, this means that package updates
9035 available as grafts are not applied. @xref{Security Updates}, for more
9036 information on grafts.
9038 @item --rounds=@var{n}
9039 Build each derivation @var{n} times in a row, and raise an error if
9040 consecutive build results are not bit-for-bit identical.
9042 This is a useful way to detect non-deterministic builds processes.
9043 Non-deterministic build processes are a problem because they make it
9044 practically impossible for users to @emph{verify} whether third-party
9045 binaries are genuine. @xref{Invoking guix challenge}, for more.
9047 Note that, currently, the differing build results are not kept around,
9048 so you will have to manually investigate in case of an error---e.g., by
9049 stashing one of the build results with @code{guix archive --export}
9050 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
9054 Do not use offload builds to other machines (@pxref{Daemon Offload
9055 Setup}). That is, always build things locally instead of offloading
9056 builds to remote machines.
9058 @item --max-silent-time=@var{seconds}
9059 When the build or substitution process remains silent for more than
9060 @var{seconds}, terminate it and report a build failure.
9062 By default, the daemon's setting is honored (@pxref{Invoking
9063 guix-daemon, @option{--max-silent-time}}).
9065 @item --timeout=@var{seconds}
9066 Likewise, when the build or substitution process lasts for more than
9067 @var{seconds}, terminate it and report a build failure.
9069 By default, the daemon's setting is honored (@pxref{Invoking
9070 guix-daemon, @option{--timeout}}).
9072 @c Note: This option is actually not part of %standard-build-options but
9073 @c most programs honor it.
9074 @cindex verbosity, of the command-line tools
9075 @cindex build logs, verbosity
9076 @item -v @var{level}
9077 @itemx --verbosity=@var{level}
9078 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
9079 output is produced, 1 is for quiet output, and 2 shows all the build log
9080 output on standard error.
9082 @item --cores=@var{n}
9084 Allow the use of up to @var{n} CPU cores for the build. The special
9085 value @code{0} means to use as many CPU cores as available.
9087 @item --max-jobs=@var{n}
9089 Allow at most @var{n} build jobs in parallel. @xref{Invoking
9090 guix-daemon, @option{--max-jobs}}, for details about this option and the
9091 equivalent @command{guix-daemon} option.
9093 @item --debug=@var{level}
9094 Produce debugging output coming from the build daemon. @var{level} must be an
9095 integer between 0 and 5; higher means more verbose output. Setting a level of
9096 4 or more may be helpful when debugging setup issues with the build daemon.
9100 Behind the scenes, @command{guix build} is essentially an interface to
9101 the @code{package-derivation} procedure of the @code{(guix packages)}
9102 module, and to the @code{build-derivations} procedure of the @code{(guix
9103 derivations)} module.
9105 In addition to options explicitly passed on the command line,
9106 @command{guix build} and other @command{guix} commands that support
9107 building honor the @env{GUIX_BUILD_OPTIONS} environment variable.
9109 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
9110 Users can define this variable to a list of command line options that
9111 will automatically be used by @command{guix build} and other
9112 @command{guix} commands that can perform builds, as in the example
9116 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
9119 These options are parsed independently, and the result is appended to
9120 the parsed command-line options.
9124 @node Package Transformation Options
9125 @subsection Package Transformation Options
9127 @cindex package variants
9128 Another set of command-line options supported by @command{guix build}
9129 and also @command{guix package} are @dfn{package transformation
9130 options}. These are options that make it possible to define @dfn{package
9131 variants}---for instance, packages built from different source code.
9132 This is a convenient way to create customized packages on the fly
9133 without having to type in the definitions of package variants
9134 (@pxref{Defining Packages}).
9138 @item --with-source=@var{source}
9139 @itemx --with-source=@var{package}=@var{source}
9140 @itemx --with-source=@var{package}@@@var{version}=@var{source}
9141 Use @var{source} as the source of @var{package}, and @var{version} as
9143 @var{source} must be a file name or a URL, as for @command{guix
9144 download} (@pxref{Invoking guix download}).
9146 When @var{package} is omitted,
9147 it is taken to be the package name specified on the
9148 command line that matches the base of @var{source}---e.g.,
9149 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
9150 package is @code{guile}.
9152 Likewise, when @var{version} is omitted, the version string is inferred from
9153 @var{source}; in the previous example, it is @code{2.0.10}.
9155 This option allows users to try out versions of packages other than the
9156 one provided by the distribution. The example below downloads
9157 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
9158 the @code{ed} package:
9161 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
9164 As a developer, @option{--with-source} makes it easy to test release
9168 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
9171 @dots{} or to build from a checkout in a pristine environment:
9174 $ git clone git://git.sv.gnu.org/guix.git
9175 $ guix build guix --with-source=guix@@1.0=./guix
9178 @item --with-input=@var{package}=@var{replacement}
9179 Replace dependency on @var{package} by a dependency on
9180 @var{replacement}. @var{package} must be a package name, and
9181 @var{replacement} must be a package specification such as @code{guile}
9182 or @code{guile@@1.8}.
9184 For instance, the following command builds Guix, but replaces its
9185 dependency on the current stable version of Guile with a dependency on
9186 the legacy version of Guile, @code{guile@@2.0}:
9189 guix build --with-input=guile=guile@@2.0 guix
9192 This is a recursive, deep replacement. So in this example, both
9193 @code{guix} and its dependency @code{guile-json} (which also depends on
9194 @code{guile}) get rebuilt against @code{guile@@2.0}.
9196 This is implemented using the @code{package-input-rewriting} Scheme
9197 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
9199 @item --with-graft=@var{package}=@var{replacement}
9200 This is similar to @option{--with-input} but with an important difference:
9201 instead of rebuilding the whole dependency chain, @var{replacement} is
9202 built and then @dfn{grafted} onto the binaries that were initially
9203 referring to @var{package}. @xref{Security Updates}, for more
9204 information on grafts.
9206 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
9207 and all its dependencies, replacing references to the version of GnuTLS
9208 they currently refer to:
9211 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
9214 This has the advantage of being much faster than rebuilding everything.
9215 But there is a caveat: it works if and only if @var{package} and
9216 @var{replacement} are strictly compatible---for example, if they provide
9217 a library, the application binary interface (ABI) of those libraries
9218 must be compatible. If @var{replacement} is somehow incompatible with
9219 @var{package}, then the resulting package may be unusable. Use with
9222 @item --with-git-url=@var{package}=@var{url}
9223 @cindex Git, using the latest commit
9224 @cindex latest commit, building
9225 Build @var{package} from the latest commit of the @code{master} branch of the
9226 Git repository at @var{url}. Git sub-modules of the repository are fetched,
9229 For example, the following command builds the NumPy Python library against the
9230 latest commit of the master branch of Python itself:
9233 guix build python-numpy \
9234 --with-git-url=python=https://github.com/python/cpython
9237 This option can also be combined with @option{--with-branch} or
9238 @option{--with-commit} (see below).
9240 @cindex continuous integration
9241 Obviously, since it uses the latest commit of the given branch, the result of
9242 such a command varies over time. Nevertheless it is a convenient way to
9243 rebuild entire software stacks against the latest commit of one or more
9244 packages. This is particularly useful in the context of continuous
9247 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
9248 consecutive accesses to the same repository. You may want to clean it up once
9249 in a while to save disk space.
9251 @item --with-branch=@var{package}=@var{branch}
9252 Build @var{package} from the latest commit of @var{branch}. If the
9253 @code{source} field of @var{package} is an origin with the @code{git-fetch}
9254 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
9255 repository URL is taken from that @code{source}. Otherwise you have to use
9256 @option{--with-git-url} to specify the URL of the Git repository.
9258 For instance, the following command builds @code{guile-sqlite3} from the
9259 latest commit of its @code{master} branch, and then builds @code{guix} (which
9260 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
9261 specific @code{guile-sqlite3} build:
9264 guix build --with-branch=guile-sqlite3=master cuirass
9267 @item --with-commit=@var{package}=@var{commit}
9268 This is similar to @option{--with-branch}, except that it builds from
9269 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
9270 Git commit SHA1 identifier or a tag.
9273 @node Additional Build Options
9274 @subsection Additional Build Options
9276 The command-line options presented below are specific to @command{guix
9283 Build quietly, without displaying the build log; this is equivalent to
9284 @option{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
9285 (or similar) and can always be retrieved using the @option{--log-file} option.
9287 @item --file=@var{file}
9288 @itemx -f @var{file}
9289 Build the package, derivation, or other file-like object that the code within
9290 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
9292 As an example, @var{file} might contain a package definition like this
9293 (@pxref{Defining Packages}):
9296 @include package-hello.scm
9299 The @var{file} may also contain a JSON representation of one or more
9300 package definitions. Running @code{guix build -f} on @file{hello.json}
9301 with the following contents would result in building the packages
9302 @code{myhello} and @code{greeter}:
9305 @verbatiminclude package-hello.json
9308 @item --manifest=@var{manifest}
9309 @itemx -m @var{manifest}
9310 Build all packages listed in the given @var{manifest}
9311 (@pxref{profile-manifest, @option{--manifest}}).
9313 @item --expression=@var{expr}
9314 @itemx -e @var{expr}
9315 Build the package or derivation @var{expr} evaluates to.
9317 For example, @var{expr} may be @code{(@@ (gnu packages guile)
9318 guile-1.8)}, which unambiguously designates this specific variant of
9319 version 1.8 of Guile.
9321 Alternatively, @var{expr} may be a G-expression, in which case it is used
9322 as a build program passed to @code{gexp->derivation}
9323 (@pxref{G-Expressions}).
9325 Lastly, @var{expr} may refer to a zero-argument monadic procedure
9326 (@pxref{The Store Monad}). The procedure must return a derivation as a
9327 monadic value, which is then passed through @code{run-with-store}.
9331 Build the source derivations of the packages, rather than the packages
9334 For instance, @code{guix build -S gcc} returns something like
9335 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
9338 The returned source tarball is the result of applying any patches and
9339 code snippets specified in the package @code{origin} (@pxref{Defining
9342 Note that @command{guix build -S} compiles the sources only of the
9343 specified packages. They do not include the sources of statically
9344 linked dependencies and by themselves are insufficient for reproducing
9348 Fetch and return the source of @var{package-or-derivation} and all their
9349 dependencies, recursively. This is a handy way to obtain a local copy
9350 of all the source code needed to build @var{packages}, allowing you to
9351 eventually build them even without network access. It is an extension
9352 of the @option{--source} option and can accept one of the following
9353 optional argument values:
9357 This value causes the @option{--sources} option to behave in the same way
9358 as the @option{--source} option.
9361 Build the source derivations of all packages, including any source that
9362 might be listed as @code{inputs}. This is the default value.
9365 $ guix build --sources tzdata
9366 The following derivations will be built:
9367 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
9368 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
9372 Build the source derivations of all packages, as well of all transitive
9373 inputs to the packages. This can be used e.g.@: to
9374 prefetch package source for later offline building.
9377 $ guix build --sources=transitive tzdata
9378 The following derivations will be built:
9379 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
9380 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
9381 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
9382 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
9383 /gnu/store/@dots{}-make-4.1.tar.xz.drv
9384 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
9390 @item --system=@var{system}
9391 @itemx -s @var{system}
9392 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
9393 the system type of the build host. The @command{guix build} command allows
9394 you to repeat this option several times, in which case it builds for all the
9395 specified systems; other commands ignore extraneous @option{-s} options.
9398 The @option{--system} flag is for @emph{native} compilation and must not
9399 be confused with cross-compilation. See @option{--target} below for
9400 information on cross-compilation.
9403 An example use of this is on Linux-based systems, which can emulate
9404 different personalities. For instance, passing
9405 @option{--system=i686-linux} on an @code{x86_64-linux} system or
9406 @option{--system=armhf-linux} on an @code{aarch64-linux} system allows
9407 you to build packages in a complete 32-bit environment.
9410 Building for an @code{armhf-linux} system is unconditionally enabled on
9411 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
9412 allow for this functionality, notably the ThunderX.
9415 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
9416 is enabled (@pxref{Virtualization Services,
9417 @code{qemu-binfmt-service-type}}), you can build for any system for
9418 which a QEMU @code{binfmt_misc} handler is installed.
9420 Builds for a system other than that of the machine you are using can
9421 also be offloaded to a remote machine of the right architecture.
9422 @xref{Daemon Offload Setup}, for more information on offloading.
9424 @item --target=@var{triplet}
9425 @cindex cross-compilation
9426 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
9427 as @code{"aarch64-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
9428 configuration triplets,, autoconf, Autoconf}).
9430 @anchor{build-check}
9432 @cindex determinism, checking
9433 @cindex reproducibility, checking
9434 Rebuild @var{package-or-derivation}, which are already available in the
9435 store, and raise an error if the build results are not bit-for-bit
9438 This mechanism allows you to check whether previously installed
9439 substitutes are genuine (@pxref{Substitutes}), or whether the build result
9440 of a package is deterministic. @xref{Invoking guix challenge}, for more
9441 background information and tools.
9443 When used in conjunction with @option{--keep-failed}, the differing
9444 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
9445 This makes it easy to look for differences between the two results.
9448 @cindex repairing store items
9449 @cindex corruption, recovering from
9450 Attempt to repair the specified store items, if they are corrupt, by
9451 re-downloading or rebuilding them.
9453 This operation is not atomic and thus restricted to @code{root}.
9457 Return the derivation paths, not the output paths, of the given
9460 @item --root=@var{file}
9461 @itemx -r @var{file}
9462 @cindex GC roots, adding
9463 @cindex garbage collector roots, adding
9464 Make @var{file} a symlink to the result, and register it as a garbage
9467 Consequently, the results of this @command{guix build} invocation are
9468 protected from garbage collection until @var{file} is removed. When
9469 that option is omitted, build results are eligible for garbage
9470 collection as soon as the build completes. @xref{Invoking guix gc}, for
9474 @cindex build logs, access
9475 Return the build log file names or URLs for the given
9476 @var{package-or-derivation}, or raise an error if build logs are
9479 This works regardless of how packages or derivations are specified. For
9480 instance, the following invocations are equivalent:
9483 guix build --log-file `guix build -d guile`
9484 guix build --log-file `guix build guile`
9485 guix build --log-file guile
9486 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
9489 If a log is unavailable locally, and unless @option{--no-substitutes} is
9490 passed, the command looks for a corresponding log on one of the
9491 substitute servers (as specified with @option{--substitute-urls}).
9493 So for instance, imagine you want to see the build log of GDB on MIPS,
9494 but you are actually on an @code{x86_64} machine:
9497 $ guix build --log-file gdb -s aarch64-linux
9498 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
9501 You can freely access a huge library of build logs!
9504 @node Debugging Build Failures
9505 @subsection Debugging Build Failures
9507 @cindex build failures, debugging
9508 When defining a new package (@pxref{Defining Packages}), you will
9509 probably find yourself spending some time debugging and tweaking the
9510 build until it succeeds. To do that, you need to operate the build
9511 commands yourself in an environment as close as possible to the one the
9514 To that end, the first thing to do is to use the @option{--keep-failed}
9515 or @option{-K} option of @command{guix build}, which will keep the
9516 failed build tree in @file{/tmp} or whatever directory you specified as
9517 @env{TMPDIR} (@pxref{Invoking guix build, @option{--keep-failed}}).
9519 From there on, you can @command{cd} to the failed build tree and source
9520 the @file{environment-variables} file, which contains all the
9521 environment variable definitions that were in place when the build
9522 failed. So let's say you're debugging a build failure in package
9523 @code{foo}; a typical session would look like this:
9527 @dots{} @i{build fails}
9528 $ cd /tmp/guix-build-foo.drv-0
9529 $ source ./environment-variables
9533 Now, you can invoke commands as if you were the daemon (almost) and
9534 troubleshoot your build process.
9536 Sometimes it happens that, for example, a package's tests pass when you
9537 run them manually but they fail when the daemon runs them. This can
9538 happen because the daemon runs builds in containers where, unlike in our
9539 environment above, network access is missing, @file{/bin/sh} does not
9540 exist, etc. (@pxref{Build Environment Setup}).
9542 In such cases, you may need to run inspect the build process from within
9543 a container similar to the one the build daemon creates:
9548 $ cd /tmp/guix-build-foo.drv-0
9549 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
9550 [env]# source ./environment-variables
9554 Here, @command{guix environment -C} creates a container and spawns a new
9555 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
9556 strace gdb} part adds the @command{strace} and @command{gdb} commands to
9557 the container, which you may find handy while debugging. The
9558 @option{--no-grafts} option makes sure we get the exact same
9559 environment, with ungrafted packages (@pxref{Security Updates}, for more
9562 To get closer to a container like that used by the build daemon, we can
9563 remove @file{/bin/sh}:
9569 (Don't worry, this is harmless: this is all happening in the throw-away
9570 container created by @command{guix environment}.)
9572 The @command{strace} command is probably not in the search path, but we
9576 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
9579 In this way, not only you will have reproduced the environment variables
9580 the daemon uses, you will also be running the build process in a container
9581 similar to the one the daemon uses.
9584 @node Invoking guix edit
9585 @section Invoking @command{guix edit}
9587 @cindex @command{guix edit}
9588 @cindex package definition, editing
9589 So many packages, so many source files! The @command{guix edit} command
9590 facilitates the life of users and packagers by pointing their editor at
9591 the source file containing the definition of the specified packages.
9595 guix edit gcc@@4.9 vim
9599 launches the program specified in the @env{VISUAL} or in the
9600 @env{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
9603 If you are using a Guix Git checkout (@pxref{Building from Git}), or
9604 have created your own packages on @env{GUIX_PACKAGE_PATH}
9605 (@pxref{Package Modules}), you will be able to edit the package
9606 recipes. In other cases, you will be able to examine the read-only recipes
9607 for packages currently in the store.
9609 Instead of @env{GUIX_PACKAGE_PATH}, the command-line option
9610 @option{--load-path=@var{directory}} (or in short @option{-L
9611 @var{directory}}) allows you to add @var{directory} to the front of the
9612 package module search path and so make your own packages visible.
9614 @node Invoking guix download
9615 @section Invoking @command{guix download}
9617 @cindex @command{guix download}
9618 @cindex downloading package sources
9619 When writing a package definition, developers typically need to download
9620 a source tarball, compute its SHA256 hash, and write that
9621 hash in the package definition (@pxref{Defining Packages}). The
9622 @command{guix download} tool helps with this task: it downloads a file
9623 from the given URI, adds it to the store, and prints both its file name
9624 in the store and its SHA256 hash.
9626 The fact that the downloaded file is added to the store saves bandwidth:
9627 when the developer eventually tries to build the newly defined package
9628 with @command{guix build}, the source tarball will not have to be
9629 downloaded again because it is already in the store. It is also a
9630 convenient way to temporarily stash files, which may be deleted
9631 eventually (@pxref{Invoking guix gc}).
9633 The @command{guix download} command supports the same URIs as used in
9634 package definitions. In particular, it supports @code{mirror://} URIs.
9635 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
9636 Guile bindings for GnuTLS are available in the user's environment; when
9637 they are not available, an error is raised. @xref{Guile Preparations,
9638 how to install the GnuTLS bindings for Guile,, gnutls-guile,
9639 GnuTLS-Guile}, for more information.
9641 @command{guix download} verifies HTTPS server certificates by loading
9642 the certificates of X.509 authorities from the directory pointed to by
9643 the @env{SSL_CERT_DIR} environment variable (@pxref{X.509
9644 Certificates}), unless @option{--no-check-certificate} is used.
9646 The following options are available:
9649 @item --hash=@var{algorithm}
9650 @itemx -H @var{algorithm}
9651 Compute a hash using the specified @var{algorithm}. @xref{Invoking guix
9652 hash}, for more information.
9654 @item --format=@var{fmt}
9656 Write the hash in the format specified by @var{fmt}. For more
9657 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
9659 @item --no-check-certificate
9660 Do not validate the X.509 certificates of HTTPS servers.
9662 When using this option, you have @emph{absolutely no guarantee} that you
9663 are communicating with the authentic server responsible for the given
9664 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
9666 @item --output=@var{file}
9667 @itemx -o @var{file}
9668 Save the downloaded file to @var{file} instead of adding it to the
9672 @node Invoking guix hash
9673 @section Invoking @command{guix hash}
9675 @cindex @command{guix hash}
9676 The @command{guix hash} command computes the hash of a file.
9677 It is primarily a convenience tool for anyone contributing to the
9678 distribution: it computes the cryptographic hash of a file, which can be
9679 used in the definition of a package (@pxref{Defining Packages}).
9681 The general syntax is:
9684 guix hash @var{option} @var{file}
9687 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
9688 hash of data read from standard input. @command{guix hash} has the
9693 @item --hash=@var{algorithm}
9694 @itemx -H @var{algorithm}
9695 Compute a hash using the specified @var{algorithm}, @code{sha256} by
9698 @var{algorithm} must the name of a cryptographic hash algorithm
9699 supported by Libgcrypt @i{via} Guile-Gcrypt---e.g., @code{sha512} or
9700 @code{sha3-256} (@pxref{Hash Functions,,, guile-gcrypt, Guile-Gcrypt
9703 @item --format=@var{fmt}
9705 Write the hash in the format specified by @var{fmt}.
9707 Supported formats: @code{base64}, @code{nix-base32}, @code{base32}, @code{base16}
9708 (@code{hex} and @code{hexadecimal} can be used as well).
9710 If the @option{--format} option is not specified, @command{guix hash}
9711 will output the hash in @code{nix-base32}. This representation is used
9712 in the definitions of packages.
9716 Compute the hash on @var{file} recursively.
9718 In this case, the hash is computed on an archive containing @var{file},
9719 including its children if it is a directory. Some of the metadata of
9720 @var{file} is part of the archive; for instance, when @var{file} is a
9721 regular file, the hash is different depending on whether @var{file} is
9722 executable or not. Metadata such as time stamps has no impact on the
9723 hash (@pxref{Invoking guix archive}).
9724 @c FIXME: Replace xref above with xref to an ``Archive'' section when
9729 When combined with @option{--recursive}, exclude version control system
9730 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.).
9733 As an example, here is how you would compute the hash of a Git checkout,
9734 which is useful when using the @code{git-fetch} method (@pxref{origin
9738 $ git clone http://example.org/foo.git
9744 @node Invoking guix import
9745 @section Invoking @command{guix import}
9747 @cindex importing packages
9748 @cindex package import
9749 @cindex package conversion
9750 @cindex Invoking @command{guix import}
9751 The @command{guix import} command is useful for people who would like to
9752 add a package to the distribution with as little work as
9753 possible---a legitimate demand. The command knows of a few
9754 repositories from which it can ``import'' package metadata. The result
9755 is a package definition, or a template thereof, in the format we know
9756 (@pxref{Defining Packages}).
9758 The general syntax is:
9761 guix import @var{importer} @var{options}@dots{}
9764 @var{importer} specifies the source from which to import package
9765 metadata, and @var{options} specifies a package identifier and other
9766 options specific to @var{importer}.
9768 Some of the importers rely on the ability to run the @command{gpgv} command.
9769 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
9772 Currently, the available ``importers'' are:
9776 Import metadata for the given GNU package. This provides a template
9777 for the latest version of that GNU package, including the hash of its
9778 source tarball, and its canonical synopsis and description.
9780 Additional information such as the package dependencies and its
9781 license needs to be figured out manually.
9783 For example, the following command returns a package definition for
9787 guix import gnu hello
9790 Specific command-line options are:
9793 @item --key-download=@var{policy}
9794 As for @command{guix refresh}, specify the policy to handle missing
9795 OpenPGP keys when verifying the package signature. @xref{Invoking guix
9796 refresh, @option{--key-download}}.
9801 Import metadata from the @uref{https://pypi.python.org/, Python Package
9802 Index}. Information is taken from the JSON-formatted description
9803 available at @code{pypi.python.org} and usually includes all the relevant
9804 information, including package dependencies. For maximum efficiency, it
9805 is recommended to install the @command{unzip} utility, so that the
9806 importer can unzip Python wheels and gather data from them.
9808 The command below imports metadata for the @code{itsdangerous} Python
9812 guix import pypi itsdangerous
9818 Traverse the dependency graph of the given upstream package recursively
9819 and generate package expressions for all those packages that are not yet
9825 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
9826 is taken from the JSON-formatted description available at
9827 @code{rubygems.org} and includes most relevant information, including
9828 runtime dependencies. There are some caveats, however. The metadata
9829 doesn't distinguish between synopses and descriptions, so the same string
9830 is used for both fields. Additionally, the details of non-Ruby
9831 dependencies required to build native extensions is unavailable and left
9832 as an exercise to the packager.
9834 The command below imports metadata for the @code{rails} Ruby package:
9837 guix import gem rails
9843 Traverse the dependency graph of the given upstream package recursively
9844 and generate package expressions for all those packages that are not yet
9850 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
9851 Information is taken from the JSON-formatted metadata provided through
9852 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
9853 relevant information, such as module dependencies. License information
9854 should be checked closely. If Perl is available in the store, then the
9855 @code{corelist} utility will be used to filter core modules out of the
9856 list of dependencies.
9858 The command command below imports metadata for the Acme::Boolean Perl
9862 guix import cpan Acme::Boolean
9867 @cindex Bioconductor
9868 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
9869 central repository for the @uref{https://r-project.org, GNU@tie{}R
9870 statistical and graphical environment}.
9872 Information is extracted from the @file{DESCRIPTION} file of the package.
9874 The command command below imports metadata for the Cairo R package:
9877 guix import cran Cairo
9880 When @option{--recursive} is added, the importer will traverse the
9881 dependency graph of the given upstream package recursively and generate
9882 package expressions for all those packages that are not yet in Guix.
9884 When @option{--archive=bioconductor} is added, metadata is imported from
9885 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
9886 packages for for the analysis and comprehension of high-throughput
9887 genomic data in bioinformatics.
9889 Information is extracted from the @file{DESCRIPTION} file contained in the
9892 The command below imports metadata for the GenomicRanges R package:
9895 guix import cran --archive=bioconductor GenomicRanges
9898 Finally, you can also import R packages that have not yet been published on
9899 CRAN or Bioconductor as long as they are in a git repository. Use
9900 @option{--archive=git} followed by the URL of the git repository:
9903 guix import cran --archive=git https://github.com/immunogenomics/harmony
9909 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
9910 comprehensive TeX archive network for TeX packages that are part of the
9911 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
9913 Information about the package is obtained through the XML API provided
9914 by CTAN, while the source code is downloaded from the SVN repository of
9915 the Tex Live project. This is done because the CTAN does not keep
9918 The command command below imports metadata for the @code{fontspec}
9922 guix import texlive fontspec
9925 When @option{--archive=@var{directory}} is added, the source code is
9926 downloaded not from the @file{latex} sub-directory of the
9927 @file{texmf-dist/source} tree in the TeX Live SVN repository, but from
9928 the specified sibling @var{directory} under the same root.
9930 The command below imports metadata for the @code{ifxetex} package from
9931 CTAN while fetching the sources from the directory
9932 @file{texmf/source/generic}:
9935 guix import texlive --archive=generic ifxetex
9939 @cindex JSON, import
9940 Import package metadata from a local JSON file. Consider the following
9941 example package definition in JSON format:
9947 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
9948 "build-system": "gnu",
9949 "home-page": "https://www.gnu.org/software/hello/",
9950 "synopsis": "Hello, GNU world: An example GNU package",
9951 "description": "GNU Hello prints a greeting.",
9952 "license": "GPL-3.0+",
9953 "native-inputs": ["gettext"]
9957 The field names are the same as for the @code{<package>} record
9958 (@xref{Defining Packages}). References to other packages are provided
9959 as JSON lists of quoted package specification strings such as
9960 @code{guile} or @code{guile@@2.0}.
9962 The importer also supports a more explicit source definition using the
9963 common fields for @code{<origin>} records:
9969 "method": "url-fetch",
9970 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
9972 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
9979 The command below reads metadata from the JSON file @code{hello.json}
9980 and outputs a package expression:
9983 guix import json hello.json
9987 Import metadata from a local copy of the source of the
9988 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
9989 relies on the @command{nix-instantiate} command of
9990 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
9991 typically written in a mixture of Nix-language and Bash code. This
9992 command only imports the high-level package structure that is written in
9993 the Nix language. It normally includes all the basic fields of a
9996 When importing a GNU package, the synopsis and descriptions are replaced
9997 by their canonical upstream variant.
9999 Usually, you will first need to do:
10002 export NIX_REMOTE=daemon
10006 so that @command{nix-instantiate} does not try to open the Nix database.
10008 As an example, the command below imports the package definition of
10009 LibreOffice (more precisely, it imports the definition of the package
10010 bound to the @code{libreoffice} top-level attribute):
10013 guix import nix ~/path/to/nixpkgs libreoffice
10018 Import metadata from the Haskell community's central package archive
10019 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
10020 Cabal files and includes all the relevant information, including package
10023 Specific command-line options are:
10028 Read a Cabal file from standard input.
10029 @item --no-test-dependencies
10031 Do not include dependencies required only by the test suites.
10032 @item --cabal-environment=@var{alist}
10033 @itemx -e @var{alist}
10034 @var{alist} is a Scheme alist defining the environment in which the
10035 Cabal conditionals are evaluated. The accepted keys are: @code{os},
10036 @code{arch}, @code{impl} and a string representing the name of a flag.
10037 The value associated with a flag has to be either the symbol
10038 @code{true} or @code{false}. The value associated with other keys
10039 has to conform to the Cabal file format definition. The default value
10040 associated with the keys @code{os}, @code{arch} and @code{impl} is
10041 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
10044 Traverse the dependency graph of the given upstream package recursively
10045 and generate package expressions for all those packages that are not yet
10049 The command below imports metadata for the latest version of the
10050 HTTP Haskell package without including test dependencies and
10051 specifying the value of the flag @samp{network-uri} as @code{false}:
10054 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
10057 A specific package version may optionally be specified by following the
10058 package name by an at-sign and a version number as in the following example:
10061 guix import hackage mtl@@2.1.3.1
10066 The @code{stackage} importer is a wrapper around the @code{hackage} one.
10067 It takes a package name, looks up the package version included in a
10068 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
10069 release and uses the @code{hackage} importer to retrieve its metadata.
10070 Note that it is up to you to select an LTS release compatible with the
10071 GHC compiler used by Guix.
10073 Specific command-line options are:
10076 @item --no-test-dependencies
10078 Do not include dependencies required only by the test suites.
10079 @item --lts-version=@var{version}
10080 @itemx -l @var{version}
10081 @var{version} is the desired LTS release version. If omitted the latest
10085 Traverse the dependency graph of the given upstream package recursively
10086 and generate package expressions for all those packages that are not yet
10090 The command below imports metadata for the HTTP Haskell package
10091 included in the LTS Stackage release version 7.18:
10094 guix import stackage --lts-version=7.18 HTTP
10099 Import metadata from an Emacs Lisp Package Archive (ELPA) package
10100 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
10102 Specific command-line options are:
10105 @item --archive=@var{repo}
10106 @itemx -a @var{repo}
10107 @var{repo} identifies the archive repository from which to retrieve the
10108 information. Currently the supported repositories and their identifiers
10112 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
10113 identifier. This is the default.
10115 Packages from @code{elpa.gnu.org} are signed with one of the keys
10116 contained in the GnuPG keyring at
10117 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
10118 @code{emacs} package (@pxref{Package Installation, ELPA package
10119 signatures,, emacs, The GNU Emacs Manual}).
10122 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
10123 @code{melpa-stable} identifier.
10126 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
10132 Traverse the dependency graph of the given upstream package recursively
10133 and generate package expressions for all those packages that are not yet
10139 Import metadata from the crates.io Rust package repository
10140 @uref{https://crates.io, crates.io}, as in this example:
10143 guix import crate blake2-rfc
10146 The crate importer also allows you to specify a version string:
10149 guix import crate constant-time-eq@@0.1.0
10152 Additional options include:
10157 Traverse the dependency graph of the given upstream package recursively
10158 and generate package expressions for all those packages that are not yet
10165 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
10166 repository used by the OCaml community.
10169 The structure of the @command{guix import} code is modular. It would be
10170 useful to have more importers for other package formats, and your help
10171 is welcome here (@pxref{Contributing}).
10173 @node Invoking guix refresh
10174 @section Invoking @command{guix refresh}
10176 @cindex @command {guix refresh}
10177 The primary audience of the @command{guix refresh} command is developers
10178 of the GNU software distribution. By default, it reports any packages
10179 provided by the distribution that are outdated compared to the latest
10180 upstream version, like this:
10184 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
10185 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
10188 Alternatively, one can specify packages to consider, in which case a
10189 warning is emitted for packages that lack an updater:
10192 $ guix refresh coreutils guile guile-ssh
10193 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
10194 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
10197 @command{guix refresh} browses the upstream repository of each package and determines
10198 the highest version number of the releases therein. The command
10199 knows how to update specific types of packages: GNU packages, ELPA
10200 packages, etc.---see the documentation for @option{--type} below. There
10201 are many packages, though, for which it lacks a method to determine
10202 whether a new upstream release is available. However, the mechanism is
10203 extensible, so feel free to get in touch with us to add a new method!
10208 Consider the packages specified, and all the packages upon which they depend.
10211 $ guix refresh --recursive coreutils
10212 gnu/packages/acl.scm:35:2: warning: no updater for acl
10213 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
10214 gnu/packages/xml.scm:68:2: warning: no updater for expat
10215 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
10221 Sometimes the upstream name differs from the package name used in Guix,
10222 and @command{guix refresh} needs a little help. Most updaters honor the
10223 @code{upstream-name} property in package definitions, which can be used
10227 (define-public network-manager
10229 (name "network-manager")
10231 (properties '((upstream-name . "NetworkManager")))))
10234 When passed @option{--update}, it modifies distribution source files to
10235 update the version numbers and source tarball hashes of those package
10236 recipes (@pxref{Defining Packages}). This is achieved by downloading
10237 each package's latest source tarball and its associated OpenPGP
10238 signature, authenticating the downloaded tarball against its signature
10239 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
10240 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
10243 key used to sign the tarball is missing from the user's keyring, an
10244 attempt is made to automatically retrieve it from a public key server;
10245 when this is successful, the key is added to the user's keyring; otherwise,
10246 @command{guix refresh} reports an error.
10248 The following options are supported:
10252 @item --expression=@var{expr}
10253 @itemx -e @var{expr}
10254 Consider the package @var{expr} evaluates to.
10256 This is useful to precisely refer to a package, as in this example:
10259 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
10262 This command lists the dependents of the ``final'' libc (essentially all
10267 Update distribution source files (package recipes) in place. This is
10268 usually run from a checkout of the Guix source tree (@pxref{Running
10269 Guix Before It Is Installed}):
10272 $ ./pre-inst-env guix refresh -s non-core -u
10275 @xref{Defining Packages}, for more information on package definitions.
10277 @item --select=[@var{subset}]
10278 @itemx -s @var{subset}
10279 Select all the packages in @var{subset}, one of @code{core} or
10282 The @code{core} subset refers to all the packages at the core of the
10283 distribution---i.e., packages that are used to build ``everything
10284 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
10285 changing one of these packages in the distribution entails a rebuild of
10286 all the others. Thus, such updates are an inconvenience to users in
10287 terms of build time or bandwidth used to achieve the upgrade.
10289 The @code{non-core} subset refers to the remaining packages. It is
10290 typically useful in cases where an update of the core packages would be
10293 @item --manifest=@var{file}
10294 @itemx -m @var{file}
10295 Select all the packages from the manifest in @var{file}. This is useful to
10296 check if any packages of the user manifest can be updated.
10298 @item --type=@var{updater}
10299 @itemx -t @var{updater}
10300 Select only packages handled by @var{updater} (may be a comma-separated
10301 list of updaters). Currently, @var{updater} may be one of:
10305 the updater for GNU packages;
10307 the updater for packages hosted at @uref{https://savannah.gnu.org, Savannah};
10309 the updater for GNOME packages;
10311 the updater for KDE packages;
10313 the updater for X.org packages;
10315 the updater for packages hosted on kernel.org;
10317 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
10319 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
10321 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
10323 the updater for @uref{https://www.cpan.org/, CPAN} packages;
10325 the updater for @uref{https://pypi.python.org, PyPI} packages.
10327 the updater for @uref{https://rubygems.org, RubyGems} packages.
10329 the updater for @uref{https://github.com, GitHub} packages.
10331 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
10333 the updater for @uref{https://www.stackage.org, Stackage} packages.
10335 the updater for @uref{https://crates.io, Crates} packages.
10337 the updater for @uref{https://launchpad.net, Launchpad} packages.
10340 For instance, the following command only checks for updates of Emacs
10341 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
10344 $ guix refresh --type=elpa,cran
10345 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
10346 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
10351 In addition, @command{guix refresh} can be passed one or more package
10352 names, as in this example:
10355 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
10359 The command above specifically updates the @code{emacs} and
10360 @code{idutils} packages. The @option{--select} option would have no
10361 effect in this case.
10363 When considering whether to upgrade a package, it is sometimes
10364 convenient to know which packages would be affected by the upgrade and
10365 should be checked for compatibility. For this the following option may
10366 be used when passing @command{guix refresh} one or more package names:
10370 @item --list-updaters
10372 List available updaters and exit (see @option{--type} above).
10374 For each updater, display the fraction of packages it covers; at the
10375 end, display the fraction of packages covered by all these updaters.
10377 @item --list-dependent
10379 List top-level dependent packages that would need to be rebuilt as a
10380 result of upgrading one or more packages.
10382 @xref{Invoking guix graph, the @code{reverse-package} type of
10383 @command{guix graph}}, for information on how to visualize the list of
10384 dependents of a package.
10388 Be aware that the @option{--list-dependent} option only
10389 @emph{approximates} the rebuilds that would be required as a result of
10390 an upgrade. More rebuilds might be required under some circumstances.
10393 $ guix refresh --list-dependent flex
10394 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
10395 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
10398 The command above lists a set of packages that could be built to check
10399 for compatibility with an upgraded @code{flex} package.
10403 @item --list-transitive
10404 List all the packages which one or more packages depend upon.
10407 $ guix refresh --list-transitive flex
10408 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
10409 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{}
10414 The command above lists a set of packages which, when changed, would cause
10415 @code{flex} to be rebuilt.
10417 The following options can be used to customize GnuPG operation:
10421 @item --gpg=@var{command}
10422 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
10423 for in @code{$PATH}.
10425 @item --keyring=@var{file}
10426 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
10427 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
10428 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
10429 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
10430 information on a tool to manipulate keybox files).
10432 When this option is omitted, @command{guix refresh} uses
10433 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
10434 signing keys. OpenPGP signatures are checked against keys from this keyring;
10435 missing keys are downloaded to this keyring as well (see
10436 @option{--key-download} below).
10438 You can export keys from your default GPG keyring into a keybox file using
10439 commands like this one:
10442 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
10445 Likewise, you can fetch keys to a specific keybox file like this:
10448 gpg --no-default-keyring --keyring mykeyring.kbx \
10449 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
10452 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
10453 Privacy Guard}, for more information on GPG's @option{--keyring} option.
10455 @item --key-download=@var{policy}
10456 Handle missing OpenPGP keys according to @var{policy}, which may be one
10461 Always download missing OpenPGP keys from the key server, and add them
10462 to the user's GnuPG keyring.
10465 Never try to download missing OpenPGP keys. Instead just bail out.
10468 When a package signed with an unknown OpenPGP key is encountered, ask
10469 the user whether to download it or not. This is the default behavior.
10472 @item --key-server=@var{host}
10473 Use @var{host} as the OpenPGP key server when importing a public key.
10475 @item --load-path=@var{directory}
10476 Add @var{directory} to the front of the package module search path
10477 (@pxref{Package Modules}).
10479 This allows users to define their own packages and make them visible to
10480 the command-line tools.
10484 The @code{github} updater uses the
10485 @uref{https://developer.github.com/v3/, GitHub API} to query for new
10486 releases. When used repeatedly e.g.@: when refreshing all packages,
10487 GitHub will eventually refuse to answer any further API requests. By
10488 default 60 API requests per hour are allowed, and a full refresh on all
10489 GitHub packages in Guix requires more than this. Authentication with
10490 GitHub through the use of an API token alleviates these limits. To use
10491 an API token, set the environment variable @env{GUIX_GITHUB_TOKEN} to a
10492 token procured from @uref{https://github.com/settings/tokens} or
10496 @node Invoking guix lint
10497 @section Invoking @command{guix lint}
10499 @cindex @command{guix lint}
10500 @cindex package, checking for errors
10501 The @command{guix lint} command is meant to help package developers avoid
10502 common errors and use a consistent style. It runs a number of checks on
10503 a given set of packages in order to find common mistakes in their
10504 definitions. Available @dfn{checkers} include (see
10505 @option{--list-checkers} for a complete list):
10510 Validate certain typographical and stylistic rules about package
10511 descriptions and synopses.
10513 @item inputs-should-be-native
10514 Identify inputs that should most likely be native inputs.
10520 @itemx source-file-name
10521 Probe @code{home-page} and @code{source} URLs and report those that are
10522 invalid. Suggest a @code{mirror://} URL when applicable. If the
10523 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
10524 URL. Check that the source file name is meaningful, e.g.@: is not just a
10525 version number or ``git-checkout'', without a declared @code{file-name}
10526 (@pxref{origin Reference}).
10528 @item source-unstable-tarball
10529 Parse the @code{source} URL to determine if a tarball from GitHub is
10530 autogenerated or if it is a release tarball. Unfortunately GitHub's
10531 autogenerated tarballs are sometimes regenerated.
10534 Check that the derivation of the given packages can be successfully
10535 computed for all the supported systems (@pxref{Derivations}).
10537 @item profile-collisions
10538 Check whether installing the given packages in a profile would lead to
10539 collisions. Collisions occur when several packages with the same name
10540 but a different version or a different store file name are propagated.
10541 @xref{package Reference, @code{propagated-inputs}}, for more information
10542 on propagated inputs.
10545 @cindex Software Heritage, source code archive
10546 @cindex archival of source code, Software Heritage
10547 Checks whether the package's source code is archived at
10548 @uref{https://www.softwareheritage.org, Software Heritage}.
10550 When the source code that is not archived comes from a version-control system
10551 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
10552 ``save'' request so that it eventually archives it. This ensures that the
10553 source will remain available in the long term, and that Guix can fall back to
10554 Software Heritage should the source code disappear from its original host.
10555 The status of recent ``save'' requests can be
10556 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
10558 When source code is a tarball obtained with @code{url-fetch}, simply print a
10559 message when it is not archived. As of this writing, Software Heritage does
10560 not allow requests to save arbitrary tarballs; we are working on ways to
10561 ensure that non-VCS source code is also archived.
10564 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
10565 request rate per IP address}. When the limit is reached, @command{guix lint}
10566 prints a message and the @code{archival} checker stops doing anything until
10567 that limit has been reset.
10570 @cindex security vulnerabilities
10571 @cindex CVE, Common Vulnerabilities and Exposures
10572 Report known vulnerabilities found in the Common Vulnerabilities and
10573 Exposures (CVE) databases of the current and past year
10574 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
10577 To view information about a particular vulnerability, visit pages such as:
10581 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
10583 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
10587 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
10588 @code{CVE-2015-7554}.
10590 Package developers can specify in package recipes the
10591 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
10592 name and version of the package when they differ from the name or version
10593 that Guix uses, as in this example:
10599 ;; CPE calls this package "grub2".
10600 (properties '((cpe-name . "grub2")
10601 (cpe-version . "2.3"))))
10604 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
10605 Some entries in the CVE database do not specify which version of a
10606 package they apply to, and would thus ``stick around'' forever. Package
10607 developers who found CVE alerts and verified they can be ignored can
10608 declare them as in this example:
10614 ;; These CVEs no longer apply and can be safely ignored.
10615 (properties `((lint-hidden-cve . ("CVE-2011-0433"
10618 "CVE-2011-5244")))))
10622 Warn about obvious source code formatting issues: trailing white space,
10623 use of tabulations, etc.
10626 The general syntax is:
10629 guix lint @var{options} @var{package}@dots{}
10632 If no package is given on the command line, then all packages are checked.
10633 The @var{options} may be zero or more of the following:
10636 @item --list-checkers
10638 List and describe all the available checkers that will be run on packages
10643 Only enable the checkers specified in a comma-separated list using the
10644 names returned by @option{--list-checkers}.
10646 @item --load-path=@var{directory}
10647 @itemx -L @var{directory}
10648 Add @var{directory} to the front of the package module search path
10649 (@pxref{Package Modules}).
10651 This allows users to define their own packages and make them visible to
10652 the command-line tools.
10656 @node Invoking guix size
10657 @section Invoking @command{guix size}
10660 @cindex package size
10662 @cindex @command{guix size}
10663 The @command{guix size} command helps package developers profile the
10664 disk usage of packages. It is easy to overlook the impact of an
10665 additional dependency added to a package, or the impact of using a
10666 single output for a package that could easily be split (@pxref{Packages
10667 with Multiple Outputs}). Such are the typical issues that
10668 @command{guix size} can highlight.
10670 The command can be passed one or more package specifications
10671 such as @code{gcc@@4.8}
10672 or @code{guile:debug}, or a file name in the store. Consider this
10676 $ guix size coreutils
10677 store item total self
10678 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
10679 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
10680 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
10681 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
10682 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
10683 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
10684 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
10685 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
10690 The store items listed here constitute the @dfn{transitive closure} of
10691 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
10692 would be returned by:
10695 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
10698 Here the output shows three columns next to store items. The first column,
10699 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
10700 the store item---that is, its own size plus the size of all its
10701 dependencies. The next column, labeled ``self'', shows the size of the
10702 item itself. The last column shows the ratio of the size of the item
10703 itself to the space occupied by all the items listed here.
10705 In this example, we see that the closure of Coreutils weighs in at
10706 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
10707 libraries. (That libc and GCC's libraries represent a large fraction of
10708 the closure is not a problem @i{per se} because they are always available
10709 on the system anyway.)
10711 Since the command also accepts store file names, assessing the size of
10712 a build result is straightforward:
10715 guix size $(guix system build config.scm)
10718 When the package(s) passed to @command{guix size} are available in the
10719 store@footnote{More precisely, @command{guix size} looks for the
10720 @emph{ungrafted} variant of the given package(s), as returned by
10721 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
10722 for information on grafts.}, @command{guix size} queries the daemon to determine its
10723 dependencies, and measures its size in the store, similar to @command{du
10724 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
10727 When the given packages are @emph{not} in the store, @command{guix size}
10728 reports information based on the available substitutes
10729 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
10730 store items that are not even on disk, only available remotely.
10732 You can also specify several package names:
10735 $ guix size coreutils grep sed bash
10736 store item total self
10737 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
10738 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
10739 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
10740 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
10746 In this example we see that the combination of the four packages takes
10747 102.3@tie{}MiB in total, which is much less than the sum of each closure
10748 since they have a lot of dependencies in common.
10750 When looking at the profile returned by @command{guix size}, you may
10751 find yourself wondering why a given package shows up in the profile at
10752 all. To understand it, you can use @command{guix graph --path -t
10753 references} to display the shortest path between the two packages
10754 (@pxref{Invoking guix graph}).
10756 The available options are:
10760 @item --substitute-urls=@var{urls}
10761 Use substitute information from @var{urls}.
10762 @xref{client-substitute-urls, the same option for @code{guix build}}.
10764 @item --sort=@var{key}
10765 Sort lines according to @var{key}, one of the following options:
10769 the size of each item (the default);
10771 the total size of the item's closure.
10774 @item --map-file=@var{file}
10775 Write a graphical map of disk usage in PNG format to @var{file}.
10777 For the example above, the map looks like this:
10779 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
10780 produced by @command{guix size}}
10782 This option requires that
10783 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
10784 installed and visible in Guile's module search path. When that is not
10785 the case, @command{guix size} fails as it tries to load it.
10787 @item --system=@var{system}
10788 @itemx -s @var{system}
10789 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
10791 @item --load-path=@var{directory}
10792 @itemx -L @var{directory}
10793 Add @var{directory} to the front of the package module search path
10794 (@pxref{Package Modules}).
10796 This allows users to define their own packages and make them visible to
10797 the command-line tools.
10800 @node Invoking guix graph
10801 @section Invoking @command{guix graph}
10804 @cindex @command{guix graph}
10805 @cindex package dependencies
10806 Packages and their dependencies form a @dfn{graph}, specifically a
10807 directed acyclic graph (DAG). It can quickly become difficult to have a
10808 mental model of the package DAG, so the @command{guix graph} command
10809 provides a visual representation of the DAG. By default,
10810 @command{guix graph} emits a DAG representation in the input format of
10811 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
10812 directly to the @command{dot} command of Graphviz. It can also emit an
10813 HTML page with embedded JavaScript code to display a ``chord diagram''
10814 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
10815 emit Cypher queries to construct a graph in a graph database supporting
10816 the @uref{https://www.opencypher.org/, openCypher} query language. With
10817 @option{--path}, it simply displays the shortest path between two
10818 packages. The general syntax is:
10821 guix graph @var{options} @var{package}@dots{}
10824 For example, the following command generates a PDF file representing the
10825 package DAG for the GNU@tie{}Core Utilities, showing its build-time
10829 guix graph coreutils | dot -Tpdf > dag.pdf
10832 The output looks like this:
10834 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
10836 Nice little graph, no?
10838 You may find it more pleasant to navigate the graph interactively with
10839 @command{xdot} (from the @code{xdot} package):
10842 guix graph coreutils | xdot -
10845 But there is more than one graph! The one above is concise: it is the
10846 graph of package objects, omitting implicit inputs such as GCC, libc,
10847 grep, etc. It is often useful to have such a concise graph, but
10848 sometimes one may want to see more details. @command{guix graph} supports
10849 several types of graphs, allowing you to choose the level of detail:
10853 This is the default type used in the example above. It shows the DAG of
10854 package objects, excluding implicit dependencies. It is concise, but
10855 filters out many details.
10857 @item reverse-package
10858 This shows the @emph{reverse} DAG of packages. For example:
10861 guix graph --type=reverse-package ocaml
10864 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
10865 you are also interested in cases where OCaml is an implicit dependency, see
10866 @code{reverse-bag} below).
10868 Note that for core packages this can yield huge graphs. If all you want
10869 is to know the number of packages that depend on a given package, use
10870 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
10871 @option{--list-dependent}}).
10874 This is the package DAG, @emph{including} implicit inputs.
10876 For instance, the following command:
10879 guix graph --type=bag-emerged coreutils
10882 ...@: yields this bigger graph:
10884 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
10886 At the bottom of the graph, we see all the implicit inputs of
10887 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
10889 Now, note that the dependencies of these implicit inputs---that is, the
10890 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
10891 here, for conciseness.
10894 Similar to @code{bag-emerged}, but this time including all the bootstrap
10897 @item bag-with-origins
10898 Similar to @code{bag}, but also showing origins and their dependencies.
10901 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
10902 it also takes implicit dependencies into account. For example:
10905 guix graph -t reverse-bag dune
10909 ...@: yields the graph of all packages that depend on Dune, directly or
10910 indirectly. Since Dune is an @emph{implicit} dependency of many packages
10911 @i{via} @code{dune-build-system}, this shows a large number of packages,
10912 whereas @code{reverse-package} would show very few if any.
10915 This is the most detailed representation: It shows the DAG of
10916 derivations (@pxref{Derivations}) and plain store items. Compared to
10917 the above representation, many additional nodes are visible, including
10918 build scripts, patches, Guile modules, etc.
10920 For this type of graph, it is also possible to pass a @file{.drv} file
10921 name instead of a package name, as in:
10924 guix graph -t derivation `guix system build -d my-config.scm`
10928 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
10929 For example, the following command shows the graph for the package
10930 module that defines the @code{guile} package:
10933 guix graph -t module guile | xdot -
10937 All the types above correspond to @emph{build-time dependencies}. The
10938 following graph type represents the @emph{run-time dependencies}:
10942 This is the graph of @dfn{references} of a package output, as returned
10943 by @command{guix gc --references} (@pxref{Invoking guix gc}).
10945 If the given package output is not available in the store, @command{guix
10946 graph} attempts to obtain dependency information from substitutes.
10948 Here you can also pass a store file name instead of a package name. For
10949 example, the command below produces the reference graph of your profile
10950 (which can be big!):
10953 guix graph -t references `readlink -f ~/.guix-profile`
10957 This is the graph of the @dfn{referrers} of a store item, as returned by
10958 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
10960 This relies exclusively on local information from your store. For
10961 instance, let us suppose that the current Inkscape is available in 10
10962 profiles on your machine; @command{guix graph -t referrers inkscape}
10963 will show a graph rooted at Inkscape and with those 10 profiles linked
10966 It can help determine what is preventing a store item from being garbage
10971 @cindex shortest path, between packages
10972 Often, the graph of the package you are interested in does not fit on
10973 your screen, and anyway all you want to know is @emph{why} that package
10974 actually depends on some seemingly unrelated package. The
10975 @option{--path} option instructs @command{guix graph} to display the
10976 shortest path between two packages (or derivations, or store items,
10980 $ guix graph --path emacs libunistring
10983 libunistring@@0.9.10
10984 $ guix graph --path -t derivation emacs libunistring
10985 /gnu/store/@dots{}-emacs-26.3.drv
10986 /gnu/store/@dots{}-mailutils-3.9.drv
10987 /gnu/store/@dots{}-libunistring-0.9.10.drv
10988 $ guix graph --path -t references emacs libunistring
10989 /gnu/store/@dots{}-emacs-26.3
10990 /gnu/store/@dots{}-libidn2-2.2.0
10991 /gnu/store/@dots{}-libunistring-0.9.10
10994 The available options are the following:
10997 @item --type=@var{type}
10998 @itemx -t @var{type}
10999 Produce a graph output of @var{type}, where @var{type} must be one of
11000 the values listed above.
11003 List the supported graph types.
11005 @item --backend=@var{backend}
11006 @itemx -b @var{backend}
11007 Produce a graph using the selected @var{backend}.
11009 @item --list-backends
11010 List the supported graph backends.
11012 Currently, the available backends are Graphviz and d3.js.
11015 Display the shortest path between two nodes of the type specified by
11016 @option{--type}. The example below shows the shortest path between
11017 @code{libreoffice} and @code{llvm} according to the references of
11018 @code{libreoffice}:
11021 $ guix graph --path -t references libreoffice llvm
11022 /gnu/store/@dots{}-libreoffice-6.4.2.2
11023 /gnu/store/@dots{}-libepoxy-1.5.4
11024 /gnu/store/@dots{}-mesa-19.3.4
11025 /gnu/store/@dots{}-llvm-9.0.1
11028 @item --expression=@var{expr}
11029 @itemx -e @var{expr}
11030 Consider the package @var{expr} evaluates to.
11032 This is useful to precisely refer to a package, as in this example:
11035 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
11038 @item --system=@var{system}
11039 @itemx -s @var{system}
11040 Display the graph for @var{system}---e.g., @code{i686-linux}.
11042 The package dependency graph is largely architecture-independent, but there
11043 are some architecture-dependent bits that this option allows you to visualize.
11045 @item --load-path=@var{directory}
11046 @itemx -L @var{directory}
11047 Add @var{directory} to the front of the package module search path
11048 (@pxref{Package Modules}).
11050 This allows users to define their own packages and make them visible to
11051 the command-line tools.
11054 On top of that, @command{guix graph} supports all the usual package
11055 transformation options (@pxref{Package Transformation Options}). This
11056 makes it easy to view the effect of a graph-rewriting transformation
11057 such as @option{--with-input}. For example, the command below outputs
11058 the graph of @code{git} once @code{openssl} has been replaced by
11059 @code{libressl} everywhere in the graph:
11062 guix graph git --with-input=openssl=libressl
11065 So many possibilities, so much fun!
11067 @node Invoking guix publish
11068 @section Invoking @command{guix publish}
11070 @cindex @command{guix publish}
11071 The purpose of @command{guix publish} is to enable users to easily share
11072 their store with others, who can then use it as a substitute server
11073 (@pxref{Substitutes}).
11075 When @command{guix publish} runs, it spawns an HTTP server which allows
11076 anyone with network access to obtain substitutes from it. This means
11077 that any machine running Guix can also act as if it were a build farm,
11078 since the HTTP interface is compatible with Cuirass, the software behind
11079 the @code{@value{SUBSTITUTE-SERVER}} build farm.
11081 For security, each substitute is signed, allowing recipients to check
11082 their authenticity and integrity (@pxref{Substitutes}). Because
11083 @command{guix publish} uses the signing key of the system, which is only
11084 readable by the system administrator, it must be started as root; the
11085 @option{--user} option makes it drop root privileges early on.
11087 The signing key pair must be generated before @command{guix publish} is
11088 launched, using @command{guix archive --generate-key} (@pxref{Invoking
11091 The general syntax is:
11094 guix publish @var{options}@dots{}
11097 Running @command{guix publish} without any additional arguments will
11098 spawn an HTTP server on port 8080:
11104 Once a publishing server has been authorized (@pxref{Invoking guix
11105 archive}), the daemon may download substitutes from it:
11108 guix-daemon --substitute-urls=http://example.org:8080
11111 By default, @command{guix publish} compresses archives on the fly as it
11112 serves them. This ``on-the-fly'' mode is convenient in that it requires
11113 no setup and is immediately available. However, when serving lots of
11114 clients, we recommend using the @option{--cache} option, which enables
11115 caching of the archives before they are sent to clients---see below for
11116 details. The @command{guix weather} command provides a handy way to
11117 check what a server provides (@pxref{Invoking guix weather}).
11119 As a bonus, @command{guix publish} also serves as a content-addressed
11120 mirror for source files referenced in @code{origin} records
11121 (@pxref{origin Reference}). For instance, assuming @command{guix
11122 publish} is running on @code{example.org}, the following URL returns the
11123 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
11124 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
11127 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
11130 Obviously, these URLs only work for files that are in the store; in
11131 other cases, they return 404 (``Not Found'').
11133 @cindex build logs, publication
11134 Build logs are available from @code{/log} URLs like:
11137 http://example.org/log/gwspk@dots{}-guile-2.2.3
11141 When @command{guix-daemon} is configured to save compressed build logs,
11142 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
11143 URLs return the compressed log as-is, with an appropriate
11144 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
11145 running @command{guix-daemon} with @option{--log-compression=gzip} since
11146 Web browsers can automatically decompress it, which is not the case with
11149 The following options are available:
11152 @item --port=@var{port}
11153 @itemx -p @var{port}
11154 Listen for HTTP requests on @var{port}.
11156 @item --listen=@var{host}
11157 Listen on the network interface for @var{host}. The default is to
11158 accept connections from any interface.
11160 @item --user=@var{user}
11161 @itemx -u @var{user}
11162 Change privileges to @var{user} as soon as possible---i.e., once the
11163 server socket is open and the signing key has been read.
11165 @item --compression[=@var{method}[:@var{level}]]
11166 @itemx -C [@var{method}[:@var{level}]]
11167 Compress data using the given @var{method} and @var{level}. @var{method} is
11168 one of @code{lzip} and @code{gzip}; when @var{method} is omitted, @code{gzip}
11171 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
11172 to different compression levels: 1 is the fastest, and 9 is the best
11173 (CPU-intensive). The default is 3.
11175 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a small
11176 increase in CPU usage; see
11177 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip Web
11180 Unless @option{--cache} is used, compression occurs on the fly and
11181 the compressed streams are not
11182 cached. Thus, to reduce load on the machine that runs @command{guix
11183 publish}, it may be a good idea to choose a low compression level, to
11184 run @command{guix publish} behind a caching proxy, or to use
11185 @option{--cache}. Using @option{--cache} has the advantage that it
11186 allows @command{guix publish} to add @code{Content-Length} HTTP header
11189 This option can be repeated, in which case every substitute gets compressed
11190 using all the selected methods, and all of them are advertised. This is
11191 useful when users may not support all the compression methods: they can select
11192 the one they support.
11194 @item --cache=@var{directory}
11195 @itemx -c @var{directory}
11196 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
11197 and only serve archives that are in cache.
11199 When this option is omitted, archives and meta-data are created
11200 on-the-fly. This can reduce the available bandwidth, especially when
11201 compression is enabled, since this may become CPU-bound. Another
11202 drawback of the default mode is that the length of archives is not known
11203 in advance, so @command{guix publish} does not add a
11204 @code{Content-Length} HTTP header to its responses, which in turn
11205 prevents clients from knowing the amount of data being downloaded.
11207 Conversely, when @option{--cache} is used, the first request for a store
11208 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
11209 background process to @dfn{bake} the archive---computing its
11210 @code{.narinfo} and compressing the archive, if needed. Once the
11211 archive is cached in @var{directory}, subsequent requests succeed and
11212 are served directly from the cache, which guarantees that clients get
11213 the best possible bandwidth.
11215 The ``baking'' process is performed by worker threads. By default, one
11216 thread per CPU core is created, but this can be customized. See
11217 @option{--workers} below.
11219 When @option{--ttl} is used, cached entries are automatically deleted
11220 when they have expired.
11222 @item --workers=@var{N}
11223 When @option{--cache} is used, request the allocation of @var{N} worker
11224 threads to ``bake'' archives.
11226 @item --ttl=@var{ttl}
11227 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
11228 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
11229 days, @code{1m} means 1 month, and so on.
11231 This allows the user's Guix to keep substitute information in cache for
11232 @var{ttl}. However, note that @code{guix publish} does not itself
11233 guarantee that the store items it provides will indeed remain available
11234 for as long as @var{ttl}.
11236 Additionally, when @option{--cache} is used, cached entries that have
11237 not been accessed for @var{ttl} and that no longer have a corresponding
11238 item in the store, may be deleted.
11240 @item --nar-path=@var{path}
11241 Use @var{path} as the prefix for the URLs of ``nar'' files
11242 (@pxref{Invoking guix archive, normalized archives}).
11244 By default, nars are served at a URL such as
11245 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
11246 change the @code{/nar} part to @var{path}.
11248 @item --public-key=@var{file}
11249 @itemx --private-key=@var{file}
11250 Use the specific @var{file}s as the public/private key pair used to sign
11251 the store items being published.
11253 The files must correspond to the same key pair (the private key is used
11254 for signing and the public key is merely advertised in the signature
11255 metadata). They must contain keys in the canonical s-expression format
11256 as produced by @command{guix archive --generate-key} (@pxref{Invoking
11257 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
11258 @file{/etc/guix/signing-key.sec} are used.
11260 @item --repl[=@var{port}]
11261 @itemx -r [@var{port}]
11262 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
11263 Reference Manual}) on @var{port} (37146 by default). This is used
11264 primarily for debugging a running @command{guix publish} server.
11267 Enabling @command{guix publish} on Guix System is a one-liner: just
11268 instantiate a @code{guix-publish-service-type} service in the @code{services} field
11269 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
11270 @code{guix-publish-service-type}}).
11272 If you are instead running Guix on a ``foreign distro'', follow these
11277 If your host distro uses the systemd init system:
11280 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
11281 /etc/systemd/system/
11282 # systemctl start guix-publish && systemctl enable guix-publish
11286 If your host distro uses the Upstart init system:
11289 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
11290 # start guix-publish
11294 Otherwise, proceed similarly with your distro's init system.
11297 @node Invoking guix challenge
11298 @section Invoking @command{guix challenge}
11300 @cindex reproducible builds
11301 @cindex verifiable builds
11302 @cindex @command{guix challenge}
11304 Do the binaries provided by this server really correspond to the source
11305 code it claims to build? Is a package build process deterministic?
11306 These are the questions the @command{guix challenge} command attempts to
11309 The former is obviously an important question: Before using a substitute
11310 server (@pxref{Substitutes}), one had better @emph{verify} that it
11311 provides the right binaries, and thus @emph{challenge} it. The latter
11312 is what enables the former: If package builds are deterministic, then
11313 independent builds of the package should yield the exact same result,
11314 bit for bit; if a server provides a binary different from the one
11315 obtained locally, it may be either corrupt or malicious.
11317 We know that the hash that shows up in @file{/gnu/store} file names is
11318 the hash of all the inputs of the process that built the file or
11319 directory---compilers, libraries, build scripts,
11320 etc. (@pxref{Introduction}). Assuming deterministic build processes,
11321 one store file name should map to exactly one build output.
11322 @command{guix challenge} checks whether there is, indeed, a single
11323 mapping by comparing the build outputs of several independent builds of
11324 any given store item.
11326 The command output looks like this:
11329 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
11330 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
11331 updating list of substitutes from 'https://guix.example.org'... 100.0%
11332 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
11333 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
11334 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
11335 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
11337 /lib/libcrypto.so.1.1
11340 /gnu/store/@dots{}-git-2.5.0 contents differ:
11341 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
11342 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
11343 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
11345 /libexec/git-core/git-fsck
11347 /gnu/store/@dots{}-pius-2.1.1 contents differ:
11348 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
11349 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
11350 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
11352 /share/man/man1/pius.1.gz
11356 6,406 store items were analyzed:
11357 - 4,749 (74.1%) were identical
11358 - 525 (8.2%) differed
11359 - 1,132 (17.7%) were inconclusive
11363 In this example, @command{guix challenge} first scans the store to
11364 determine the set of locally-built derivations---as opposed to store
11365 items that were downloaded from a substitute server---and then queries
11366 all the substitute servers. It then reports those store items for which
11367 the servers obtained a result different from the local build.
11369 @cindex non-determinism, in package builds
11370 As an example, @code{guix.example.org} always gets a different answer.
11371 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
11372 case of Git. This might indicate that the build process of Git is
11373 non-deterministic, meaning that its output varies as a function of
11374 various things that Guix does not fully control, in spite of building
11375 packages in isolated environments (@pxref{Features}). Most common
11376 sources of non-determinism include the addition of timestamps in build
11377 results, the inclusion of random numbers, and directory listings sorted
11378 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
11381 To find out what is wrong with this Git binary, the easiest approach is
11385 guix challenge git \
11386 --diff=diffoscope \
11387 --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
11390 This automatically invokes @command{diffoscope}, which displays detailed
11391 information about files that differ.
11393 Alternatively, we can do something along these lines (@pxref{Invoking guix
11397 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-git-2.5.0 \
11398 | lzip -d | guix archive -x /tmp/git
11399 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
11402 This command shows the difference between the files resulting from the
11403 local build, and the files resulting from the build on
11404 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
11405 diffutils, Comparing and Merging Files}). The @command{diff} command
11406 works great for text files. When binary files differ, a better option
11407 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
11408 visualize differences for all kinds of files.
11410 Once you have done that work, you can tell whether the differences are due
11411 to a non-deterministic build process or to a malicious server. We try
11412 hard to remove sources of non-determinism in packages to make it easier
11413 to verify substitutes, but of course, this is a process that
11414 involves not just Guix, but a large part of the free software community.
11415 In the meantime, @command{guix challenge} is one tool to help address
11418 If you are writing packages for Guix, you are encouraged to check
11419 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
11420 same build result as you did with:
11423 $ guix challenge @var{package}
11427 where @var{package} is a package specification such as
11428 @code{guile@@2.0} or @code{glibc:debug}.
11430 The general syntax is:
11433 guix challenge @var{options} [@var{packages}@dots{}]
11436 When a difference is found between the hash of a locally-built item and
11437 that of a server-provided substitute, or among substitutes provided by
11438 different servers, the command displays it as in the example above and
11439 its exit code is 2 (other non-zero exit codes denote other kinds of
11442 The one option that matters is:
11446 @item --substitute-urls=@var{urls}
11447 Consider @var{urls} the whitespace-separated list of substitute source
11448 URLs to compare to.
11450 @item --diff=@var{mode}
11451 Upon mismatches, show differences according to @var{mode}, one of:
11454 @item @code{simple} (the default)
11455 Show the list of files that differ.
11457 @item @code{diffoscope}
11458 @itemx @var{command}
11459 Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
11460 two directories whose contents do not match.
11462 When @var{command} is an absolute file name, run @var{command} instead
11466 Do not show further details about the differences.
11469 Thus, unless @option{--diff=none} is passed, @command{guix challenge}
11470 downloads the store items from the given substitute servers so that it
11475 Show details about matches (identical contents) in addition to
11476 information about mismatches.
11480 @node Invoking guix copy
11481 @section Invoking @command{guix copy}
11483 @cindex copy, of store items, over SSH
11484 @cindex SSH, copy of store items
11485 @cindex sharing store items across machines
11486 @cindex transferring store items across machines
11487 The @command{guix copy} command copies items from the store of one
11488 machine to that of another machine over a secure shell (SSH)
11489 connection@footnote{This command is available only when Guile-SSH was
11490 found. @xref{Requirements}, for details.}. For example, the following
11491 command copies the @code{coreutils} package, the user's profile, and all
11492 their dependencies over to @var{host}, logged in as @var{user}:
11495 guix copy --to=@var{user}@@@var{host} \
11496 coreutils `readlink -f ~/.guix-profile`
11499 If some of the items to be copied are already present on @var{host},
11500 they are not actually sent.
11502 The command below retrieves @code{libreoffice} and @code{gimp} from
11503 @var{host}, assuming they are available there:
11506 guix copy --from=@var{host} libreoffice gimp
11509 The SSH connection is established using the Guile-SSH client, which is
11510 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
11511 @file{~/.ssh/config}, and uses the SSH agent for authentication.
11513 The key used to sign items that are sent must be accepted by the remote
11514 machine. Likewise, the key used by the remote machine to sign items you
11515 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
11516 own daemon. @xref{Invoking guix archive}, for more information about
11517 store item authentication.
11519 The general syntax is:
11522 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
11525 You must always specify one of the following options:
11528 @item --to=@var{spec}
11529 @itemx --from=@var{spec}
11530 Specify the host to send to or receive from. @var{spec} must be an SSH
11531 spec such as @code{example.org}, @code{charlie@@example.org}, or
11532 @code{charlie@@example.org:2222}.
11535 The @var{items} can be either package names, such as @code{gimp}, or
11536 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
11538 When specifying the name of a package to send, it is first built if
11539 needed, unless @option{--dry-run} was specified. Common build options
11540 are supported (@pxref{Common Build Options}).
11543 @node Invoking guix container
11544 @section Invoking @command{guix container}
11546 @cindex @command{guix container}
11548 As of version @value{VERSION}, this tool is experimental. The interface
11549 is subject to radical change in the future.
11552 The purpose of @command{guix container} is to manipulate processes
11553 running within an isolated environment, commonly known as a
11554 ``container'', typically created by the @command{guix environment}
11555 (@pxref{Invoking guix environment}) and @command{guix system container}
11556 (@pxref{Invoking guix system}) commands.
11558 The general syntax is:
11561 guix container @var{action} @var{options}@dots{}
11564 @var{action} specifies the operation to perform with a container, and
11565 @var{options} specifies the context-specific arguments for the action.
11567 The following actions are available:
11571 Execute a command within the context of a running container.
11576 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
11579 @var{pid} specifies the process ID of the running container.
11580 @var{program} specifies an executable file name within the root file
11581 system of the container. @var{arguments} are the additional options that
11582 will be passed to @var{program}.
11584 The following command launches an interactive login shell inside a
11585 Guix system container, started by @command{guix system container}, and whose
11586 process ID is 9001:
11589 guix container exec 9001 /run/current-system/profile/bin/bash --login
11592 Note that the @var{pid} cannot be the parent process of a container. It
11593 must be PID 1 of the container or one of its child processes.
11597 @node Invoking guix weather
11598 @section Invoking @command{guix weather}
11600 Occasionally you're grumpy because substitutes are lacking and you end
11601 up building packages by yourself (@pxref{Substitutes}). The
11602 @command{guix weather} command reports on substitute availability on the
11603 specified servers so you can have an idea of whether you'll be grumpy
11604 today. It can sometimes be useful info as a user, but it is primarily
11605 useful to people running @command{guix publish} (@pxref{Invoking guix
11608 @cindex statistics, for substitutes
11609 @cindex availability of substitutes
11610 @cindex substitute availability
11611 @cindex weather, substitute availability
11612 Here's a sample run:
11615 $ guix weather --substitute-urls=https://guix.example.org
11616 computing 5,872 package derivations for x86_64-linux...
11617 looking for 6,128 store items on https://guix.example.org..
11618 updating list of substitutes from 'https://guix.example.org'... 100.0%
11619 https://guix.example.org
11620 43.4% substitutes available (2,658 out of 6,128)
11621 7,032.5 MiB of nars (compressed)
11622 19,824.2 MiB on disk (uncompressed)
11623 0.030 seconds per request (182.9 seconds in total)
11624 33.5 requests per second
11626 9.8% (342 out of 3,470) of the missing items are queued
11628 x86_64-linux: 518 (59.7%)
11629 i686-linux: 221 (25.5%)
11630 aarch64-linux: 128 (14.8%)
11631 build rate: 23.41 builds per hour
11632 x86_64-linux: 11.16 builds per hour
11633 i686-linux: 6.03 builds per hour
11634 aarch64-linux: 6.41 builds per hour
11637 @cindex continuous integration, statistics
11638 As you can see, it reports the fraction of all the packages for which
11639 substitutes are available on the server---regardless of whether
11640 substitutes are enabled, and regardless of whether this server's signing
11641 key is authorized. It also reports the size of the compressed archives
11642 (``nars'') provided by the server, the size the corresponding store
11643 items occupy in the store (assuming deduplication is turned off), and
11644 the server's throughput. The second part gives continuous integration
11645 (CI) statistics, if the server supports it. In addition, using the
11646 @option{--coverage} option, @command{guix weather} can list ``important''
11647 package substitutes missing on the server (see below).
11649 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
11650 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
11651 challenge}, it ignores signatures on those substitutes, which is
11652 innocuous since the command only gathers statistics and cannot install
11655 The general syntax is:
11658 guix weather @var{options}@dots{} [@var{packages}@dots{}]
11661 When @var{packages} is omitted, @command{guix weather} checks the availability
11662 of substitutes for @emph{all} the packages, or for those specified with
11663 @option{--manifest}; otherwise it only considers the specified packages. It
11664 is also possible to query specific system types with @option{--system}.
11665 @command{guix weather} exits with a non-zero code when the fraction of
11666 available substitutes is below 100%.
11668 The available options are listed below.
11671 @item --substitute-urls=@var{urls}
11672 @var{urls} is the space-separated list of substitute server URLs to
11673 query. When this option is omitted, the default set of substitute
11674 servers is queried.
11676 @item --system=@var{system}
11677 @itemx -s @var{system}
11678 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
11679 option can be repeated, in which case @command{guix weather} will query
11680 substitutes for several system types.
11682 @item --manifest=@var{file}
11683 Instead of querying substitutes for all the packages, only ask for those
11684 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
11685 with the @code{-m} option of @command{guix package} (@pxref{Invoking
11688 This option can be repeated several times, in which case the manifests
11691 @item --coverage[=@var{count}]
11692 @itemx -c [@var{count}]
11693 Report on substitute coverage for packages: list packages with at least
11694 @var{count} dependents (zero by default) for which substitutes are
11695 unavailable. Dependent packages themselves are not listed: if @var{b} depends
11696 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
11697 @var{b} usually lacks substitutes as well. The result looks like this:
11700 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
11701 computing 8,983 package derivations for x86_64-linux...
11702 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
11703 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
11704 @value{SUBSTITUTE-URL}
11705 64.7% substitutes available (6,047 out of 9,343)
11707 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
11708 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
11709 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
11710 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
11714 What this example shows is that @code{kcoreaddons} and presumably the 58
11715 packages that depend on it have no substitutes at @code{ci.guix.info};
11716 likewise for @code{qgpgme} and the 46 packages that depend on it.
11718 If you are a Guix developer, or if you are taking care of this build farm,
11719 you'll probably want to have a closer look at these packages: they may simply
11722 @item --display-missing
11723 Display the list of store items for which substitutes are missing.
11726 @node Invoking guix processes
11727 @section Invoking @command{guix processes}
11729 The @command{guix processes} command can be useful to developers and system
11730 administrators, especially on multi-user machines and on build farms: it lists
11731 the current sessions (connections to the daemon), as well as information about
11732 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
11733 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
11734 listed.}. Here's an example of the information it returns:
11737 $ sudo guix processes
11740 ClientCommand: guix environment --ad-hoc python
11744 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
11748 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
11749 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
11750 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
11751 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
11752 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
11753 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
11754 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
11757 In this example we see that @command{guix-daemon} has three clients:
11758 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
11759 integration tool; their process identifier (PID) is given by the
11760 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
11761 @command{guix-daemon} sub-process of this particular session.
11763 The @code{LockHeld} fields show which store items are currently locked by this
11764 session, which corresponds to store items being built or substituted (the
11765 @code{LockHeld} field is not displayed when @command{guix processes} is not
11766 running as root). Last, by looking at the @code{ChildProcess} field, we
11767 understand that these three builds are being offloaded (@pxref{Daemon Offload
11770 The output is in Recutils format so we can use the handy @command{recsel}
11771 command to select sessions of interest (@pxref{Selection Expressions,,,
11772 recutils, GNU recutils manual}). As an example, the command shows the command
11773 line and PID of the client that triggered the build of a Perl package:
11776 $ sudo guix processes | \
11777 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
11779 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
11782 @node System Configuration
11783 @chapter System Configuration
11785 @cindex system configuration
11786 Guix System supports a consistent whole-system configuration
11787 mechanism. By that we mean that all aspects of the global system
11788 configuration---such as the available system services, timezone and
11789 locale settings, user accounts---are declared in a single place. Such
11790 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
11792 One of the advantages of putting all the system configuration under the
11793 control of Guix is that it supports transactional system upgrades, and
11794 makes it possible to roll back to a previous system instantiation,
11795 should something go wrong with the new one (@pxref{Features}). Another
11796 advantage is that it makes it easy to replicate the exact same configuration
11797 across different machines, or at different points in time, without
11798 having to resort to additional administration tools layered on top of
11799 the own tools of the system.
11800 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
11802 This section describes this mechanism. First we focus on the system
11803 administrator's viewpoint---explaining how the system is configured and
11804 instantiated. Then we show how this mechanism can be extended, for
11805 instance to support new system services.
11808 * Using the Configuration System:: Customizing your GNU system.
11809 * operating-system Reference:: Detail of operating-system declarations.
11810 * File Systems:: Configuring file system mounts.
11811 * Mapped Devices:: Block device extra processing.
11812 * User Accounts:: Specifying user accounts.
11813 * Keyboard Layout:: How the system interprets key strokes.
11814 * Locales:: Language and cultural convention settings.
11815 * Services:: Specifying system services.
11816 * Setuid Programs:: Programs running with root privileges.
11817 * X.509 Certificates:: Authenticating HTTPS servers.
11818 * Name Service Switch:: Configuring libc's name service switch.
11819 * Initial RAM Disk:: Linux-Libre bootstrapping.
11820 * Bootloader Configuration:: Configuring the boot loader.
11821 * Invoking guix system:: Instantiating a system configuration.
11822 * Invoking guix deploy:: Deploying a system configuration to a remote host.
11823 * Running Guix in a VM:: How to run Guix System in a virtual machine.
11824 * Defining Services:: Adding new service definitions.
11827 @node Using the Configuration System
11828 @section Using the Configuration System
11830 The operating system is configured by providing an
11831 @code{operating-system} declaration in a file that can then be passed to
11832 the @command{guix system} command (@pxref{Invoking guix system}). A
11833 simple setup, with the default system services, the default Linux-Libre
11834 kernel, initial RAM disk, and boot loader looks like this:
11836 @findex operating-system
11838 @include os-config-bare-bones.texi
11841 This example should be self-describing. Some of the fields defined
11842 above, such as @code{host-name} and @code{bootloader}, are mandatory.
11843 Others, such as @code{packages} and @code{services}, can be omitted, in
11844 which case they get a default value.
11846 Below we discuss the effect of some of the most important fields
11847 (@pxref{operating-system Reference}, for details about all the available
11848 fields), and how to @dfn{instantiate} the operating system using
11849 @command{guix system}.
11851 @unnumberedsubsec Bootloader
11853 @cindex legacy boot, on Intel machines
11854 @cindex BIOS boot, on Intel machines
11857 The @code{bootloader} field describes the method that will be used to boot
11858 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
11859 mode, as in the example above. However, more recent machines rely instead on
11860 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
11861 the @code{bootloader} field should contain something along these lines:
11864 (bootloader-configuration
11865 (bootloader grub-efi-bootloader)
11866 (target "/boot/efi"))
11869 @xref{Bootloader Configuration}, for more information on the available
11870 configuration options.
11872 @unnumberedsubsec Globally-Visible Packages
11874 @vindex %base-packages
11875 The @code{packages} field lists packages that will be globally visible
11876 on the system, for all user accounts---i.e., in every user's @env{PATH}
11877 environment variable---in addition to the per-user profiles
11878 (@pxref{Invoking guix package}). The @code{%base-packages} variable
11879 provides all the tools one would expect for basic user and administrator
11880 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
11881 the GNU Zile lightweight text editor, @command{find}, @command{grep},
11882 etc. The example above adds GNU@tie{}Screen to those,
11883 taken from the @code{(gnu packages screen)}
11884 module (@pxref{Package Modules}). The
11885 @code{(list package output)} syntax can be used to add a specific output
11889 (use-modules (gnu packages))
11890 (use-modules (gnu packages dns))
11894 (packages (cons (list bind "utils")
11898 @findex specification->package
11899 Referring to packages by variable name, like @code{bind} above, has
11900 the advantage of being unambiguous; it also allows typos and such to be
11901 diagnosed right away as ``unbound variables''. The downside is that one
11902 needs to know which module defines which package, and to augment the
11903 @code{use-package-modules} line accordingly. To avoid that, one can use
11904 the @code{specification->package} procedure of the @code{(gnu packages)}
11905 module, which returns the best package for a given name or name and
11909 (use-modules (gnu packages))
11913 (packages (append (map specification->package
11914 '("tcpdump" "htop" "gnupg@@2.0"))
11918 @unnumberedsubsec System Services
11921 @vindex %base-services
11922 The @code{services} field lists @dfn{system services} to be made
11923 available when the system starts (@pxref{Services}).
11924 The @code{operating-system} declaration above specifies that, in
11925 addition to the basic services, we want the OpenSSH secure shell
11926 daemon listening on port 2222 (@pxref{Networking Services,
11927 @code{openssh-service-type}}). Under the hood,
11928 @code{openssh-service-type} arranges so that @command{sshd} is started with the
11929 right command-line options, possibly with supporting configuration files
11930 generated as needed (@pxref{Defining Services}).
11932 @cindex customization, of services
11933 @findex modify-services
11934 Occasionally, instead of using the base services as is, you will want to
11935 customize them. To do this, use @code{modify-services} (@pxref{Service
11936 Reference, @code{modify-services}}) to modify the list.
11938 For example, suppose you want to modify @code{guix-daemon} and Mingetty
11939 (the console log-in) in the @code{%base-services} list (@pxref{Base
11940 Services, @code{%base-services}}). To do that, you can write the
11941 following in your operating system declaration:
11944 (define %my-services
11945 ;; My very own list of services.
11946 (modify-services %base-services
11947 (guix-service-type config =>
11948 (guix-configuration
11950 (use-substitutes? #f)
11951 (extra-options '("--gc-keep-derivations"))))
11952 (mingetty-service-type config =>
11953 (mingetty-configuration
11954 (inherit config)))))
11958 (services %my-services))
11961 This changes the configuration---i.e., the service parameters---of the
11962 @code{guix-service-type} instance, and that of all the
11963 @code{mingetty-service-type} instances in the @code{%base-services} list.
11964 Observe how this is accomplished: first, we arrange for the original
11965 configuration to be bound to the identifier @code{config} in the
11966 @var{body}, and then we write the @var{body} so that it evaluates to the
11967 desired configuration. In particular, notice how we use @code{inherit}
11968 to create a new configuration which has the same values as the old
11969 configuration, but with a few modifications.
11971 @cindex encrypted disk
11972 The configuration for a typical ``desktop'' usage, with an encrypted
11973 root partition, the X11 display
11974 server, GNOME and Xfce (users can choose which of these desktop
11975 environments to use at the log-in screen by pressing @kbd{F1}), network
11976 management, power management, and more, would look like this:
11979 @include os-config-desktop.texi
11982 A graphical system with a choice of lightweight window managers
11983 instead of full-blown desktop environments would look like this:
11986 @include os-config-lightweight-desktop.texi
11989 This example refers to the @file{/boot/efi} file system by its UUID,
11990 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
11991 as returned by the @command{blkid} command.
11993 @xref{Desktop Services}, for the exact list of services provided by
11994 @code{%desktop-services}. @xref{X.509 Certificates}, for background
11995 information about the @code{nss-certs} package that is used here.
11997 Again, @code{%desktop-services} is just a list of service objects. If
11998 you want to remove services from there, you can do so using the
11999 procedures for list filtering (@pxref{SRFI-1 Filtering and
12000 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
12001 following expression returns a list that contains all the services in
12002 @code{%desktop-services} minus the Avahi service:
12005 (remove (lambda (service)
12006 (eq? (service-kind service) avahi-service-type))
12010 @unnumberedsubsec Instantiating the System
12012 Assuming the @code{operating-system} declaration
12013 is stored in the @file{my-system-config.scm}
12014 file, the @command{guix system reconfigure my-system-config.scm} command
12015 instantiates that configuration, and makes it the default GRUB boot
12016 entry (@pxref{Invoking guix system}).
12018 The normal way to change the system configuration is by updating this
12019 file and re-running @command{guix system reconfigure}. One should never
12020 have to touch files in @file{/etc} or to run commands that modify the
12021 system state such as @command{useradd} or @command{grub-install}. In
12022 fact, you must avoid that since that would not only void your warranty
12023 but also prevent you from rolling back to previous versions of your
12024 system, should you ever need to.
12026 @cindex roll-back, of the operating system
12027 Speaking of roll-back, each time you run @command{guix system
12028 reconfigure}, a new @dfn{generation} of the system is created---without
12029 modifying or deleting previous generations. Old system generations get
12030 an entry in the bootloader boot menu, allowing you to boot them in case
12031 something went wrong with the latest generation. Reassuring, no? The
12032 @command{guix system list-generations} command lists the system
12033 generations available on disk. It is also possible to roll back the
12034 system via the commands @command{guix system roll-back} and
12035 @command{guix system switch-generation}.
12037 Although the @command{guix system reconfigure} command will not modify
12038 previous generations, you must take care when the current generation is not
12039 the latest (e.g., after invoking @command{guix system roll-back}), since
12040 the operation might overwrite a later generation (@pxref{Invoking guix
12043 @unnumberedsubsec The Programming Interface
12045 At the Scheme level, the bulk of an @code{operating-system} declaration
12046 is instantiated with the following monadic procedure (@pxref{The Store
12049 @deffn {Monadic Procedure} operating-system-derivation os
12050 Return a derivation that builds @var{os}, an @code{operating-system}
12051 object (@pxref{Derivations}).
12053 The output of the derivation is a single directory that refers to all
12054 the packages, configuration files, and other supporting files needed to
12055 instantiate @var{os}.
12058 This procedure is provided by the @code{(gnu system)} module. Along
12059 with @code{(gnu services)} (@pxref{Services}), this module contains the
12060 guts of Guix System. Make sure to visit it!
12063 @node operating-system Reference
12064 @section @code{operating-system} Reference
12066 This section summarizes all the options available in
12067 @code{operating-system} declarations (@pxref{Using the Configuration
12070 @deftp {Data Type} operating-system
12071 This is the data type representing an operating system configuration.
12072 By that, we mean all the global system configuration, not per-user
12073 configuration (@pxref{Using the Configuration System}).
12076 @item @code{kernel} (default: @code{linux-libre})
12077 The package object of the operating system kernel to
12078 use@footnote{Currently only the Linux-libre kernel is fully supported.
12079 Using GNU@tie{}mach with the GNU@tie{}Hurd is experimental and only
12080 available when building a virtual machine disk image.}.
12083 @item @code{hurd} (default: @code{#f})
12084 The package object of the hurd to be started by the kernel. When this
12085 field is set, produce a GNU/Hurd operating system. In that case,
12086 @code{kernel} must also be set to the @code{gnumach} package---the
12087 microkernel the Hurd runs on.
12090 This feature is experimental and only supported for disk images.
12093 @item @code{kernel-loadable-modules} (default: '())
12094 A list of objects (usually packages) to collect loadable kernel modules
12095 from--e.g. @code{(list ddcci-driver-linux)}.
12097 @item @code{kernel-arguments} (default: @code{%default-kernel-arguments})
12098 List of strings or gexps representing additional arguments to pass on
12099 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
12101 @item @code{bootloader}
12102 The system bootloader configuration object. @xref{Bootloader Configuration}.
12105 This is the label (a string) as it appears in the bootloader's menu entry.
12106 The default label includes the kernel name and version.
12108 @item @code{keyboard-layout} (default: @code{#f})
12109 This field specifies the keyboard layout to use in the console. It can be
12110 either @code{#f}, in which case the default keyboard layout is used (usually
12111 US English), or a @code{<keyboard-layout>} record.
12113 This keyboard layout is in effect as soon as the kernel has booted. For
12114 instance, it is the keyboard layout in effect when you type a passphrase if
12115 your root file system is on a @code{luks-device-mapping} mapped device
12116 (@pxref{Mapped Devices}).
12119 This does @emph{not} specify the keyboard layout used by the bootloader, nor
12120 that used by the graphical display server. @xref{Bootloader Configuration},
12121 for information on how to specify the bootloader's keyboard layout. @xref{X
12122 Window}, for information on how to specify the keyboard layout used by the X
12126 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
12128 @cindex initial RAM disk
12129 The list of Linux kernel modules that need to be available in the
12130 initial RAM disk. @xref{Initial RAM Disk}.
12132 @item @code{initrd} (default: @code{base-initrd})
12133 A procedure that returns an initial RAM disk for the Linux
12134 kernel. This field is provided to support low-level customization and
12135 should rarely be needed for casual use. @xref{Initial RAM Disk}.
12137 @item @code{firmware} (default: @code{%base-firmware})
12139 List of firmware packages loadable by the operating system kernel.
12141 The default includes firmware needed for Atheros- and Broadcom-based
12142 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
12143 respectively). @xref{Hardware Considerations}, for more info on
12144 supported hardware.
12146 @item @code{host-name}
12149 @item @code{hosts-file}
12151 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
12152 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
12153 Reference Manual}). The default is a file with entries for
12154 @code{localhost} and @var{host-name}.
12156 @item @code{mapped-devices} (default: @code{'()})
12157 A list of mapped devices. @xref{Mapped Devices}.
12159 @item @code{file-systems}
12160 A list of file systems. @xref{File Systems}.
12162 @item @code{swap-devices} (default: @code{'()})
12163 @cindex swap devices
12164 A list of strings identifying devices or files to be used for ``swap
12165 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
12166 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
12167 It is possible to specify a swap file in a file system on a mapped
12168 device, provided that the necessary device mapping and file system are
12169 also specified. @xref{Mapped Devices} and @ref{File Systems}.
12171 @item @code{users} (default: @code{%base-user-accounts})
12172 @itemx @code{groups} (default: @code{%base-groups})
12173 List of user accounts and groups. @xref{User Accounts}.
12175 If the @code{users} list lacks a user account with UID@tie{}0, a
12176 ``root'' account with UID@tie{}0 is automatically added.
12178 @item @code{skeletons} (default: @code{(default-skeletons)})
12179 A list of target file name/file-like object tuples (@pxref{G-Expressions,
12180 file-like objects}). These are the skeleton files that will be added to
12181 the home directory of newly-created user accounts.
12183 For instance, a valid value may look like this:
12186 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
12187 (".guile" ,(plain-file "guile"
12188 "(use-modules (ice-9 readline))
12189 (activate-readline)")))
12192 @item @code{issue} (default: @code{%default-issue})
12193 A string denoting the contents of the @file{/etc/issue} file, which is
12194 displayed when users log in on a text console.
12196 @item @code{packages} (default: @code{%base-packages})
12197 A list of packages to be installed in the global profile, which is accessible
12198 at @file{/run/current-system/profile}. Each element is either a package
12199 variable or a package/output tuple. Here's a simple example of both:
12202 (cons* git ; the default "out" output
12203 (list git "send-email") ; another output of git
12204 %base-packages) ; the default set
12207 The default set includes core utilities and it is good practice to
12208 install non-core utilities in user profiles (@pxref{Invoking guix
12211 @item @code{timezone}
12212 A timezone identifying string---e.g., @code{"Europe/Paris"}.
12214 You can run the @command{tzselect} command to find out which timezone
12215 string corresponds to your region. Choosing an invalid timezone name
12216 causes @command{guix system} to fail.
12218 @item @code{locale} (default: @code{"en_US.utf8"})
12219 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
12220 Library Reference Manual}). @xref{Locales}, for more information.
12222 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
12223 The list of locale definitions to be compiled and that may be used at
12224 run time. @xref{Locales}.
12226 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
12227 The list of GNU@tie{}libc packages whose locale data and tools are used
12228 to build the locale definitions. @xref{Locales}, for compatibility
12229 considerations that justify this option.
12231 @item @code{name-service-switch} (default: @code{%default-nss})
12232 Configuration of the libc name service switch (NSS)---a
12233 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
12236 @item @code{services} (default: @code{%base-services})
12237 A list of service objects denoting system services. @xref{Services}.
12239 @cindex essential services
12240 @item @code{essential-services} (default: ...)
12241 The list of ``essential services''---i.e., things like instances of
12242 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
12243 Reference}), which are derived from the operating system definition itself.
12244 As a user you should @emph{never} need to touch this field.
12246 @item @code{pam-services} (default: @code{(base-pam-services)})
12248 @cindex pluggable authentication modules
12249 Linux @dfn{pluggable authentication module} (PAM) services.
12250 @c FIXME: Add xref to PAM services section.
12252 @item @code{setuid-programs} (default: @code{%setuid-programs})
12253 List of string-valued G-expressions denoting setuid programs.
12254 @xref{Setuid Programs}.
12256 @item @code{sudoers-file} (default: @code{%sudoers-specification})
12257 @cindex sudoers file
12258 The contents of the @file{/etc/sudoers} file as a file-like object
12259 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
12261 This file specifies which users can use the @command{sudo} command, what
12262 they are allowed to do, and what privileges they may gain. The default
12263 is that only @code{root} and members of the @code{wheel} group may use
12268 @deffn {Scheme Syntax} this-operating-system
12269 When used in the @emph{lexical scope} of an operating system field definition,
12270 this identifier resolves to the operating system being defined.
12272 The example below shows how to refer to the operating system being defined in
12273 the definition of the @code{label} field:
12276 (use-modules (gnu) (guix))
12280 (label (package-full-name
12281 (operating-system-kernel this-operating-system))))
12284 It is an error to refer to @code{this-operating-system} outside an operating
12291 @section File Systems
12293 The list of file systems to be mounted is specified in the
12294 @code{file-systems} field of the operating system declaration
12295 (@pxref{Using the Configuration System}). Each file system is declared
12296 using the @code{file-system} form, like this:
12300 (mount-point "/home")
12301 (device "/dev/sda3")
12305 As usual, some of the fields are mandatory---those shown in the example
12306 above---while others can be omitted. These are described below.
12308 @deftp {Data Type} file-system
12309 Objects of this type represent file systems to be mounted. They
12310 contain the following members:
12314 This is a string specifying the type of the file system---e.g.,
12317 @item @code{mount-point}
12318 This designates the place where the file system is to be mounted.
12320 @item @code{device}
12321 This names the ``source'' of the file system. It can be one of three
12322 things: a file system label, a file system UUID, or the name of a
12323 @file{/dev} node. Labels and UUIDs offer a way to refer to file
12324 systems without having to hard-code their actual device
12325 name@footnote{Note that, while it is tempting to use
12326 @file{/dev/disk/by-uuid} and similar device names to achieve the same
12327 result, this is not recommended: These special device nodes are created
12328 by the udev daemon and may be unavailable at the time the device is
12331 @findex file-system-label
12332 File system labels are created using the @code{file-system-label}
12333 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
12334 plain strings. Here's an example of a file system referred to by its
12335 label, as shown by the @command{e2label} command:
12339 (mount-point "/home")
12341 (device (file-system-label "my-home")))
12345 UUIDs are converted from their string representation (as shown by the
12346 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
12347 @code{uuid} form expects 16-byte UUIDs as defined in
12348 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
12349 form of UUID used by the ext2 family of file systems and others, but it
12350 is different from ``UUIDs'' found in FAT file systems, for instance.},
12355 (mount-point "/home")
12357 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
12360 When the source of a file system is a mapped device (@pxref{Mapped
12361 Devices}), its @code{device} field @emph{must} refer to the mapped
12362 device name---e.g., @file{"/dev/mapper/root-partition"}.
12363 This is required so that
12364 the system knows that mounting the file system depends on having the
12365 corresponding device mapping established.
12367 @item @code{flags} (default: @code{'()})
12368 This is a list of symbols denoting mount flags. Recognized flags
12369 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
12370 access to special files), @code{no-suid} (ignore setuid and setgid
12371 bits), @code{no-atime} (do not update file access times),
12372 @code{strict-atime} (update file access time), @code{lazy-time} (only
12373 update time on the in-memory version of the file inode), and
12374 @code{no-exec} (disallow program execution).
12375 @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
12376 Manual}, for more information on these flags.
12378 @item @code{options} (default: @code{#f})
12379 This is either @code{#f}, or a string denoting mount options passed to
12380 the file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C
12381 Library Reference Manual}, for details and run @command{man 8 mount} for
12382 options for various file systems. Note that the
12383 @code{file-system-options->alist} and @code{alist->file-system-options}
12384 procedures from @code{(gnu system file-systems)} can be used to convert
12385 file system options given as an association list to the string
12386 representation, and vice-versa.
12388 @item @code{mount?} (default: @code{#t})
12389 This value indicates whether to automatically mount the file system when
12390 the system is brought up. When set to @code{#f}, the file system gets
12391 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
12392 is not automatically mounted.
12394 @item @code{needed-for-boot?} (default: @code{#f})
12395 This Boolean value indicates whether the file system is needed when
12396 booting. If that is true, then the file system is mounted when the
12397 initial RAM disk (initrd) is loaded. This is always the case, for
12398 instance, for the root file system.
12400 @item @code{check?} (default: @code{#t})
12401 This Boolean indicates whether the file system needs to be checked for
12402 errors before being mounted.
12404 @item @code{create-mount-point?} (default: @code{#f})
12405 When true, the mount point is created if it does not exist yet.
12407 @item @code{mount-may-fail?} (default: @code{#f})
12408 When true, this indicates that mounting this file system can fail but
12409 that should not be considered an error. This is useful in unusual
12410 cases; an example of this is @code{efivarfs}, a file system that can
12411 only be mounted on EFI/UEFI systems.
12413 @item @code{dependencies} (default: @code{'()})
12414 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
12415 representing file systems that must be mounted or mapped devices that
12416 must be opened before (and unmounted or closed after) this one.
12418 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
12419 a dependency of @file{/sys/fs/cgroup/cpu} and
12420 @file{/sys/fs/cgroup/memory}.
12422 Another example is a file system that depends on a mapped device, for
12423 example for an encrypted partition (@pxref{Mapped Devices}).
12427 @deffn {Scheme Procedure} file-system-label @var{str}
12428 This procedure returns an opaque file system label from @var{str}, a
12432 (file-system-label "home")
12433 @result{} #<file-system-label "home">
12436 File system labels are used to refer to file systems by label rather
12437 than by device name. See above for examples.
12440 The @code{(gnu system file-systems)} exports the following useful
12443 @defvr {Scheme Variable} %base-file-systems
12444 These are essential file systems that are required on normal systems,
12445 such as @code{%pseudo-terminal-file-system} and @code{%immutable-store} (see
12446 below). Operating system declarations should always contain at least
12450 @defvr {Scheme Variable} %pseudo-terminal-file-system
12451 This is the file system to be mounted as @file{/dev/pts}. It supports
12452 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
12453 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
12454 Manual}). Pseudo-terminals are used by terminal emulators such as
12458 @defvr {Scheme Variable} %shared-memory-file-system
12459 This file system is mounted as @file{/dev/shm} and is used to support
12460 memory sharing across processes (@pxref{Memory-mapped I/O,
12461 @code{shm_open},, libc, The GNU C Library Reference Manual}).
12464 @defvr {Scheme Variable} %immutable-store
12465 This file system performs a read-only ``bind mount'' of
12466 @file{/gnu/store}, making it read-only for all the users including
12467 @code{root}. This prevents against accidental modification by software
12468 running as @code{root} or by system administrators.
12470 The daemon itself is still able to write to the store: it remounts it
12471 read-write in its own ``name space.''
12474 @defvr {Scheme Variable} %binary-format-file-system
12475 The @code{binfmt_misc} file system, which allows handling of arbitrary
12476 executable file types to be delegated to user space. This requires the
12477 @code{binfmt.ko} kernel module to be loaded.
12480 @defvr {Scheme Variable} %fuse-control-file-system
12481 The @code{fusectl} file system, which allows unprivileged users to mount
12482 and unmount user-space FUSE file systems. This requires the
12483 @code{fuse.ko} kernel module to be loaded.
12486 The @code{(gnu system uuid)} module provides tools to deal with file
12487 system ``unique identifiers'' (UUIDs).
12489 @deffn {Scheme Procedure} uuid @var{str} [@var{type}]
12490 Return an opaque UUID (unique identifier) object of the given @var{type}
12491 (a symbol) by parsing @var{str} (a string):
12494 (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")
12495 @result{} #<<uuid> type: dce bv: @dots{}>
12497 (uuid "1234-ABCD" 'fat)
12498 @result{} #<<uuid> type: fat bv: @dots{}>
12501 @var{type} may be one of @code{dce}, @code{iso9660}, @code{fat},
12502 @code{ntfs}, or one of the commonly found synonyms for these.
12504 UUIDs are another way to unambiguously refer to file systems in
12505 operating system configuration. See the examples above.
12509 @node Btrfs file system
12510 @subsection Btrfs file system
12512 The Btrfs has special features, such as subvolumes, that merit being
12513 explained in more details. The following section attempts to cover
12514 basic as well as complex uses of a Btrfs file system with the Guix
12517 In its simplest usage, a Btrfs file system can be described, for
12522 (mount-point "/home")
12524 (device (file-system-label "my-home")))
12527 The example below is more complex, as it makes use of a Btrfs
12528 subvolume, named @code{rootfs}. The parent Btrfs file system is labeled
12529 @code{my-btrfs-pool}, and is located on an encrypted device (hence the
12530 dependency on @code{mapped-devices}):
12534 (device (file-system-label "my-btrfs-pool"))
12537 (options "subvol=rootfs")
12538 (dependencies mapped-devices))
12541 Some bootloaders, for example GRUB, only mount a Btrfs partition at its
12542 top level during the early boot, and rely on their configuration to
12543 refer to the correct subvolume path within that top level. The
12544 bootloaders operating in this way typically produce their configuration
12545 on a running system where the Btrfs partitions are already mounted and
12546 where the subvolume information is readily available. As an example,
12547 @command{grub-mkconfig}, the configuration generator command shipped
12548 with GRUB, reads @file{/proc/self/mountinfo} to determine the top-level
12549 path of a subvolume.
12551 The Guix System produces a bootloader configuration using the operating
12552 system configuration as its sole input; it is therefore necessary to
12553 extract the subvolume name on which @file{/gnu/store} lives (if any)
12554 from that operating system configuration. To better illustrate,
12555 consider a subvolume named 'rootfs' which contains the root file system
12556 data. In such situation, the GRUB bootloader would only see the top
12557 level of the root Btrfs partition, e.g.:
12561 ├── rootfs (subvolume directory)
12562 ├── gnu (normal directory)
12563 ├── store (normal directory)
12567 Thus, the subvolume name must be prepended to the @file{/gnu/store} path
12568 of the kernel, initrd binaries and any other files referred to in the
12569 GRUB configuration that must be found during the early boot.
12571 The next example shows a nested hierarchy of subvolumes and
12576 ├── rootfs (subvolume)
12577 ├── gnu (normal directory)
12578 ├── store (subvolume)
12582 This scenario would work without mounting the 'store' subvolume.
12583 Mounting 'rootfs' is sufficient, since the subvolume name matches its
12584 intended mount point in the file system hierarchy. Alternatively, the
12585 'store' subvolume could be referred to by setting the @code{subvol}
12586 option to either @code{/rootfs/gnu/store} or @code{rootfs/gnu/store}.
12588 Finally, a more contrived example of nested subvolumes:
12592 ├── root-snapshots (subvolume)
12593 ├── root-current (subvolume)
12594 ├── guix-store (subvolume)
12598 Here, the 'guix-store' subvolume doesn't match its intended mount point,
12599 so it is necessary to mount it. The subvolume must be fully specified,
12600 by passing its file name to the @code{subvol} option. To illustrate,
12601 the 'guix-store' subvolume could be mounted on @file{/gnu/store} by using
12602 a file system declaration such as:
12606 (device (file-system-label "btrfs-pool-1"))
12607 (mount-point "/gnu/store")
12609 (options "subvol=root-snapshots/root-current/guix-store,\
12610 compress-force=zstd,space_cache=v2"))
12613 @node Mapped Devices
12614 @section Mapped Devices
12616 @cindex device mapping
12617 @cindex mapped devices
12618 The Linux kernel has a notion of @dfn{device mapping}: a block device,
12619 such as a hard disk partition, can be @dfn{mapped} into another device,
12620 usually in @code{/dev/mapper/},
12621 with additional processing over the data that flows through
12622 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
12623 concept of a ``mapped device'' and that of a file system: both boil down
12624 to @emph{translating} input/output operations made on a file to
12625 operations on its backing store. Thus, the Hurd implements mapped
12626 devices, like file systems, using the generic @dfn{translator} mechanism
12627 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
12628 typical example is encryption device mapping: all writes to the mapped
12629 device are encrypted, and all reads are deciphered, transparently.
12630 Guix extends this notion by considering any device or set of devices that
12631 are @dfn{transformed} in some way to create a new device; for instance,
12632 RAID devices are obtained by @dfn{assembling} several other devices, such
12633 as hard disks or partitions, into a new one that behaves as one partition.
12634 Other examples, not yet implemented, are LVM logical volumes.
12636 Mapped devices are declared using the @code{mapped-device} form,
12637 defined as follows; for examples, see below.
12639 @deftp {Data Type} mapped-device
12640 Objects of this type represent device mappings that will be made when
12641 the system boots up.
12645 This is either a string specifying the name of the block device to be mapped,
12646 such as @code{"/dev/sda3"}, or a list of such strings when several devices
12647 need to be assembled for creating a new one.
12650 This string specifies the name of the resulting mapped device. For
12651 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
12652 specifying @code{"my-partition"} leads to the creation of
12653 the @code{"/dev/mapper/my-partition"} device.
12654 For RAID devices of type @code{raid-device-mapping}, the full device name
12655 such as @code{"/dev/md0"} needs to be given.
12658 This must be a @code{mapped-device-kind} object, which specifies how
12659 @var{source} is mapped to @var{target}.
12663 @defvr {Scheme Variable} luks-device-mapping
12664 This defines LUKS block device encryption using the @command{cryptsetup}
12665 command from the package with the same name. It relies on the
12666 @code{dm-crypt} Linux kernel module.
12669 @defvr {Scheme Variable} raid-device-mapping
12670 This defines a RAID device, which is assembled using the @code{mdadm}
12671 command from the package with the same name. It requires a Linux kernel
12672 module for the appropriate RAID level to be loaded, such as @code{raid456}
12673 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
12676 @cindex disk encryption
12678 The following example specifies a mapping from @file{/dev/sda3} to
12679 @file{/dev/mapper/home} using LUKS---the
12680 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
12681 standard mechanism for disk encryption.
12682 The @file{/dev/mapper/home}
12683 device can then be used as the @code{device} of a @code{file-system}
12684 declaration (@pxref{File Systems}).
12688 (source "/dev/sda3")
12690 (type luks-device-mapping))
12693 Alternatively, to become independent of device numbering, one may obtain
12694 the LUKS UUID (@dfn{unique identifier}) of the source device by a
12698 cryptsetup luksUUID /dev/sda3
12701 and use it as follows:
12705 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
12707 (type luks-device-mapping))
12710 @cindex swap encryption
12711 It is also desirable to encrypt swap space, since swap space may contain
12712 sensitive data. One way to accomplish that is to use a swap file in a
12713 file system on a device mapped via LUKS encryption. In this way, the
12714 swap file is encrypted because the entire device is encrypted.
12715 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
12717 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
12718 may be declared as follows:
12722 (source (list "/dev/sda1" "/dev/sdb1"))
12723 (target "/dev/md0")
12724 (type raid-device-mapping))
12727 The @file{/dev/md0} device can then be used as the @code{device} of a
12728 @code{file-system} declaration (@pxref{File Systems}).
12729 Note that the RAID level need not be given; it is chosen during the
12730 initial creation and formatting of the RAID device and is determined
12731 automatically later.
12734 @node User Accounts
12735 @section User Accounts
12739 @cindex user accounts
12740 User accounts and groups are entirely managed through the
12741 @code{operating-system} declaration. They are specified with the
12742 @code{user-account} and @code{user-group} forms:
12748 (supplementary-groups '("wheel" ;allow use of sudo, etc.
12749 "audio" ;sound card
12750 "video" ;video devices such as webcams
12751 "cdrom")) ;the good ol' CD-ROM
12752 (comment "Bob's sister")
12753 (home-directory "/home/alice"))
12756 When booting or upon completion of @command{guix system reconfigure},
12757 the system ensures that only the user accounts and groups specified in
12758 the @code{operating-system} declaration exist, and with the specified
12759 properties. Thus, account or group creations or modifications made by
12760 directly invoking commands such as @command{useradd} are lost upon
12761 reconfiguration or reboot. This ensures that the system remains exactly
12764 @deftp {Data Type} user-account
12765 Objects of this type represent user accounts. The following members may
12770 The name of the user account.
12774 This is the name (a string) or identifier (a number) of the user group
12775 this account belongs to.
12777 @item @code{supplementary-groups} (default: @code{'()})
12778 Optionally, this can be defined as a list of group names that this
12779 account belongs to.
12781 @item @code{uid} (default: @code{#f})
12782 This is the user ID for this account (a number), or @code{#f}. In the
12783 latter case, a number is automatically chosen by the system when the
12784 account is created.
12786 @item @code{comment} (default: @code{""})
12787 A comment about the account, such as the account owner's full name.
12789 @item @code{home-directory}
12790 This is the name of the home directory for the account.
12792 @item @code{create-home-directory?} (default: @code{#t})
12793 Indicates whether the home directory of this account should be created
12794 if it does not exist yet.
12796 @item @code{shell} (default: Bash)
12797 This is a G-expression denoting the file name of a program to be used as
12798 the shell (@pxref{G-Expressions}).
12800 @item @code{system?} (default: @code{#f})
12801 This Boolean value indicates whether the account is a ``system''
12802 account. System accounts are sometimes treated specially; for instance,
12803 graphical login managers do not list them.
12805 @anchor{user-account-password}
12806 @cindex password, for user accounts
12807 @item @code{password} (default: @code{#f})
12808 You would normally leave this field to @code{#f}, initialize user
12809 passwords as @code{root} with the @command{passwd} command, and then let
12810 users change it with @command{passwd}. Passwords set with
12811 @command{passwd} are of course preserved across reboot and
12814 If you @emph{do} want to set an initial password for an account, then
12815 this field must contain the encrypted password, as a string. You can use the
12816 @code{crypt} procedure for this purpose:
12823 ;; Specify a SHA-512-hashed initial password.
12824 (password (crypt "InitialPassword!" "$6$abc")))
12828 The hash of this initial password will be available in a file in
12829 @file{/gnu/store}, readable by all the users, so this method must be used with
12833 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
12834 more information on password encryption, and @ref{Encryption,,, guile, GNU
12835 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
12841 User group declarations are even simpler:
12844 (user-group (name "students"))
12847 @deftp {Data Type} user-group
12848 This type is for, well, user groups. There are just a few fields:
12852 The name of the group.
12854 @item @code{id} (default: @code{#f})
12855 The group identifier (a number). If @code{#f}, a new number is
12856 automatically allocated when the group is created.
12858 @item @code{system?} (default: @code{#f})
12859 This Boolean value indicates whether the group is a ``system'' group.
12860 System groups have low numerical IDs.
12862 @item @code{password} (default: @code{#f})
12863 What, user groups can have a password? Well, apparently yes. Unless
12864 @code{#f}, this field specifies the password of the group.
12869 For convenience, a variable lists all the basic user groups one may
12872 @defvr {Scheme Variable} %base-groups
12873 This is the list of basic user groups that users and/or packages expect
12874 to be present on the system. This includes groups such as ``root'',
12875 ``wheel'', and ``users'', as well as groups used to control access to
12876 specific devices such as ``audio'', ``disk'', and ``cdrom''.
12879 @defvr {Scheme Variable} %base-user-accounts
12880 This is the list of basic system accounts that programs may expect to
12881 find on a GNU/Linux system, such as the ``nobody'' account.
12883 Note that the ``root'' account is not included here. It is a
12884 special-case and is automatically added whether or not it is specified.
12887 @node Keyboard Layout
12888 @section Keyboard Layout
12890 @cindex keyboard layout
12892 To specify what each key of your keyboard does, you need to tell the operating
12893 system what @dfn{keyboard layout} you want to use. The default, when nothing
12894 is specified, is the US English QWERTY layout for 105-key PC keyboards.
12895 However, German speakers will usually prefer the German QWERTZ layout, French
12896 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
12897 or bépo, and they might even want to further customize the effect of some of
12898 the keys. This section explains how to get that done.
12900 @cindex keyboard layout, definition
12901 There are three components that will want to know about your keyboard layout:
12905 The @emph{bootloader} may want to know what keyboard layout you want to use
12906 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
12907 you want, for instance, to make sure that you can type the passphrase of your
12908 encrypted root partition using the right layout.
12911 The @emph{operating system kernel}, Linux, will need that so that the console
12912 is properly configured (@pxref{operating-system Reference,
12913 @code{keyboard-layout}}).
12916 The @emph{graphical display server}, usually Xorg, also has its own idea of
12917 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
12920 Guix allows you to configure all three separately but, fortunately, it allows
12921 you to share the same keyboard layout for all three components.
12923 @cindex XKB, keyboard layouts
12924 Keyboard layouts are represented by records created by the
12925 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
12926 the X Keyboard extension (XKB), each layout has four attributes: a name (often
12927 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
12928 optional variant name, an optional keyboard model name, and a possibly empty
12929 list of additional options. In most cases the layout name is all you care
12930 about. Here are a few example:
12933 ;; The German QWERTZ layout. Here we assume a standard
12934 ;; "pc105" keyboard model.
12935 (keyboard-layout "de")
12937 ;; The bépo variant of the French layout.
12938 (keyboard-layout "fr" "bepo")
12940 ;; The Catalan layout.
12941 (keyboard-layout "es" "cat")
12943 ;; Arabic layout with "Alt-Shift" to switch to US layout.
12944 (keyboard-layout "ar,us" #:options '("grp:alt_shift_toggle"))
12946 ;; The Latin American Spanish layout. In addition, the
12947 ;; "Caps Lock" key is used as an additional "Ctrl" key,
12948 ;; and the "Menu" key is used as a "Compose" key to enter
12949 ;; accented letters.
12950 (keyboard-layout "latam"
12951 #:options '("ctrl:nocaps" "compose:menu"))
12953 ;; The Russian layout for a ThinkPad keyboard.
12954 (keyboard-layout "ru" #:model "thinkpad")
12956 ;; The "US international" layout, which is the US layout plus
12957 ;; dead keys to enter accented characters. This is for an
12958 ;; Apple MacBook keyboard.
12959 (keyboard-layout "us" "intl" #:model "macbook78")
12962 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
12963 for a complete list of supported layouts, variants, and models.
12965 @cindex keyboard layout, configuration
12966 Let's say you want your system to use the Turkish keyboard layout throughout
12967 your system---bootloader, console, and Xorg. Here's what your system
12968 configuration would look like:
12970 @findex set-xorg-configuration
12972 ;; Using the Turkish layout for the bootloader, the console,
12977 (keyboard-layout (keyboard-layout "tr")) ;for the console
12978 (bootloader (bootloader-configuration
12979 (bootloader grub-efi-bootloader)
12980 (target "/boot/efi")
12981 (keyboard-layout keyboard-layout))) ;for GRUB
12982 (services (cons (set-xorg-configuration
12983 (xorg-configuration ;for Xorg
12984 (keyboard-layout keyboard-layout)))
12985 %desktop-services)))
12988 In the example above, for GRUB and for Xorg, we just refer to the
12989 @code{keyboard-layout} field defined above, but we could just as well refer to
12990 a different layout. The @code{set-xorg-configuration} procedure communicates
12991 the desired Xorg configuration to the graphical log-in manager, by default
12994 We've discussed how to specify the @emph{default} keyboard layout of your
12995 system when it starts, but you can also adjust it at run time:
12999 If you're using GNOME, its settings panel has a ``Region & Language'' entry
13000 where you can select one or more keyboard layouts.
13003 Under Xorg, the @command{setxkbmap} command (from the same-named package)
13004 allows you to change the current layout. For example, this is how you would
13005 change the layout to US Dvorak:
13008 setxkbmap us dvorak
13012 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
13013 console. However, note that @code{loadkeys} does @emph{not} use the XKB
13014 keyboard layout categorization described above. The command below loads the
13015 French bépo layout:
13026 A @dfn{locale} defines cultural conventions for a particular language
13027 and region of the world (@pxref{Locales,,, libc, The GNU C Library
13028 Reference Manual}). Each locale has a name that typically has the form
13029 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
13030 @code{fr_LU.utf8} designates the locale for the French language, with
13031 cultural conventions from Luxembourg, and using the UTF-8 encoding.
13033 @cindex locale definition
13034 Usually, you will want to specify the default locale for the machine
13035 using the @code{locale} field of the @code{operating-system} declaration
13036 (@pxref{operating-system Reference, @code{locale}}).
13038 The selected locale is automatically added to the @dfn{locale
13039 definitions} known to the system if needed, with its codeset inferred
13040 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
13041 @code{UTF-8} codeset. Additional locale definitions can be specified in
13042 the @code{locale-definitions} slot of @code{operating-system}---this is
13043 useful, for instance, if the codeset could not be inferred from the
13044 locale name. The default set of locale definitions includes some widely
13045 used locales, but not all the available locales, in order to save space.
13047 For instance, to add the North Frisian locale for Germany, the value of
13051 (cons (locale-definition
13052 (name "fy_DE.utf8") (source "fy_DE"))
13053 %default-locale-definitions)
13056 Likewise, to save space, one might want @code{locale-definitions} to
13057 list only the locales that are actually used, as in:
13060 (list (locale-definition
13061 (name "ja_JP.eucjp") (source "ja_JP")
13062 (charset "EUC-JP")))
13066 The compiled locale definitions are available at
13067 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
13068 version, which is the default location where the GNU@tie{}libc provided
13069 by Guix looks for locale data. This can be overridden using the
13070 @env{LOCPATH} environment variable (@pxref{locales-and-locpath,
13071 @env{LOCPATH} and locale packages}).
13073 The @code{locale-definition} form is provided by the @code{(gnu system
13074 locale)} module. Details are given below.
13076 @deftp {Data Type} locale-definition
13077 This is the data type of a locale definition.
13082 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
13083 Reference Manual}, for more information on locale names.
13085 @item @code{source}
13086 The name of the source for that locale. This is typically the
13087 @code{@var{language}_@var{territory}} part of the locale name.
13089 @item @code{charset} (default: @code{"UTF-8"})
13090 The ``character set'' or ``code set'' for that locale,
13091 @uref{https://www.iana.org/assignments/character-sets, as defined by
13097 @defvr {Scheme Variable} %default-locale-definitions
13098 A list of commonly used UTF-8 locales, used as the default
13099 value of the @code{locale-definitions} field of @code{operating-system}
13102 @cindex locale name
13103 @cindex normalized codeset in locale names
13104 These locale definitions use the @dfn{normalized codeset} for the part
13105 that follows the dot in the name (@pxref{Using gettextized software,
13106 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
13107 instance it has @code{uk_UA.utf8} but @emph{not}, say,
13108 @code{uk_UA.UTF-8}.
13111 @subsection Locale Data Compatibility Considerations
13113 @cindex incompatibility, of locale data
13114 @code{operating-system} declarations provide a @code{locale-libcs} field
13115 to specify the GNU@tie{}libc packages that are used to compile locale
13116 declarations (@pxref{operating-system Reference}). ``Why would I
13117 care?'', you may ask. Well, it turns out that the binary format of
13118 locale data is occasionally incompatible from one libc version to
13121 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
13122 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
13123 For instance, a program linked against libc version 2.21 is unable to
13124 read locale data produced with libc 2.22; worse, that program
13125 @emph{aborts} instead of simply ignoring the incompatible locale
13126 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
13127 the incompatible locale data, which is already an improvement.}.
13128 Similarly, a program linked against libc 2.22 can read most, but not
13129 all, of the locale data from libc 2.21 (specifically, @env{LC_COLLATE}
13130 data is incompatible); thus calls to @code{setlocale} may fail, but
13131 programs will not abort.
13133 The ``problem'' with Guix is that users have a lot of freedom: They can
13134 choose whether and when to upgrade software in their profiles, and might
13135 be using a libc version different from the one the system administrator
13136 used to build the system-wide locale data.
13138 Fortunately, unprivileged users can also install their own locale data
13139 and define @env{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
13140 @env{GUIX_LOCPATH} and locale packages}).
13142 Still, it is best if the system-wide locale data at
13143 @file{/run/current-system/locale} is built for all the libc versions
13144 actually in use on the system, so that all the programs can access
13145 it---this is especially crucial on a multi-user system. To do that, the
13146 administrator can specify several libc packages in the
13147 @code{locale-libcs} field of @code{operating-system}:
13150 (use-package-modules base)
13154 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
13157 This example would lead to a system containing locale definitions for
13158 both libc 2.21 and the current version of libc in
13159 @file{/run/current-system/locale}.
13165 @cindex system services
13166 An important part of preparing an @code{operating-system} declaration is
13167 listing @dfn{system services} and their configuration (@pxref{Using the
13168 Configuration System}). System services are typically daemons launched
13169 when the system boots, or other actions needed at that time---e.g.,
13170 configuring network access.
13172 Guix has a broad definition of ``service'' (@pxref{Service
13173 Composition}), but many services are managed by the GNU@tie{}Shepherd
13174 (@pxref{Shepherd Services}). On a running system, the @command{herd}
13175 command allows you to list the available services, show their status,
13176 start and stop them, or do other specific operations (@pxref{Jump
13177 Start,,, shepherd, The GNU Shepherd Manual}). For example:
13183 The above command, run as @code{root}, lists the currently defined
13184 services. The @command{herd doc} command shows a synopsis of the given
13185 service and its associated actions:
13189 Run libc's name service cache daemon (nscd).
13191 # herd doc nscd action invalidate
13192 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
13195 The @command{start}, @command{stop}, and @command{restart} sub-commands
13196 have the effect you would expect. For instance, the commands below stop
13197 the nscd service and restart the Xorg display server:
13201 Service nscd has been stopped.
13202 # herd restart xorg-server
13203 Service xorg-server has been stopped.
13204 Service xorg-server has been started.
13207 The following sections document the available services, starting with
13208 the core services, that may be used in an @code{operating-system}
13212 * Base Services:: Essential system services.
13213 * Scheduled Job Execution:: The mcron service.
13214 * Log Rotation:: The rottlog service.
13215 * Networking Services:: Network setup, SSH daemon, etc.
13216 * Unattended Upgrades:: Automated system upgrades.
13217 * X Window:: Graphical display.
13218 * Printing Services:: Local and remote printer support.
13219 * Desktop Services:: D-Bus and desktop services.
13220 * Sound Services:: ALSA and Pulseaudio services.
13221 * Database Services:: SQL databases, key-value stores, etc.
13222 * Mail Services:: IMAP, POP3, SMTP, and all that.
13223 * Messaging Services:: Messaging services.
13224 * Telephony Services:: Telephony services.
13225 * Monitoring Services:: Monitoring services.
13226 * Kerberos Services:: Kerberos services.
13227 * LDAP Services:: LDAP services.
13228 * Web Services:: Web servers.
13229 * Certificate Services:: TLS certificates via Let's Encrypt.
13230 * DNS Services:: DNS daemons.
13231 * VPN Services:: VPN daemons.
13232 * Network File System:: NFS related services.
13233 * Continuous Integration:: The Cuirass service.
13234 * Power Management Services:: Extending battery life.
13235 * Audio Services:: The MPD.
13236 * Virtualization Services:: Virtualization services.
13237 * Version Control Services:: Providing remote access to Git repositories.
13238 * Game Services:: Game servers.
13239 * PAM Mount Service:: Service to mount volumes when logging in.
13240 * Guix Services:: Services relating specifically to Guix.
13241 * Linux Services:: Services tied to the Linux kernel.
13242 * Hurd Services:: Services specific for a Hurd System.
13243 * Miscellaneous Services:: Other services.
13246 @node Base Services
13247 @subsection Base Services
13249 The @code{(gnu services base)} module provides definitions for the basic
13250 services that one expects from the system. The services exported by
13251 this module are listed below.
13253 @defvr {Scheme Variable} %base-services
13254 This variable contains a list of basic services (@pxref{Service Types
13255 and Services}, for more information on service objects) one would
13256 expect from the system: a login service (mingetty) on each tty, syslogd,
13257 the libc name service cache daemon (nscd), the udev device manager, and
13260 This is the default value of the @code{services} field of
13261 @code{operating-system} declarations. Usually, when customizing a
13262 system, you will want to append services to @code{%base-services}, like
13266 (append (list (service avahi-service-type)
13267 (service openssh-service-type))
13272 @defvr {Scheme Variable} special-files-service-type
13273 This is the service that sets up ``special files'' such as
13274 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
13276 The value associated with @code{special-files-service-type} services
13277 must be a list of tuples where the first element is the ``special file''
13278 and the second element is its target. By default it is:
13280 @cindex @file{/bin/sh}
13281 @cindex @file{sh}, in @file{/bin}
13283 `(("/bin/sh" ,(file-append bash "/bin/sh")))
13286 @cindex @file{/usr/bin/env}
13287 @cindex @file{env}, in @file{/usr/bin}
13288 If you want to add, say, @code{/usr/bin/env} to your system, you can
13292 `(("/bin/sh" ,(file-append bash "/bin/sh"))
13293 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
13296 Since this is part of @code{%base-services}, you can use
13297 @code{modify-services} to customize the set of special files
13298 (@pxref{Service Reference, @code{modify-services}}). But the simple way
13299 to add a special file is @i{via} the @code{extra-special-file} procedure
13303 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
13304 Use @var{target} as the ``special file'' @var{file}.
13306 For example, adding the following lines to the @code{services} field of
13307 your operating system declaration leads to a @file{/usr/bin/env}
13311 (extra-special-file "/usr/bin/env"
13312 (file-append coreutils "/bin/env"))
13316 @deffn {Scheme Procedure} host-name-service @var{name}
13317 Return a service that sets the host name to @var{name}.
13320 @defvr {Scheme Variable} console-font-service-type
13321 Install the given fonts on the specified ttys (fonts are per
13322 virtual console on the kernel Linux). The value of this service is a list of
13323 tty/font pairs. The font can be the name of a font provided by the @code{kbd}
13324 package or any valid argument to @command{setfont}, as in this example:
13327 `(("tty1" . "LatGrkCyr-8x16")
13328 ("tty2" . ,(file-append
13330 "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
13331 ("tty3" . ,(file-append
13333 "/share/consolefonts/ter-132n"))) ; for HDPI
13337 @deffn {Scheme Procedure} login-service @var{config}
13338 Return a service to run login according to @var{config}, a
13339 @code{<login-configuration>} object, which specifies the message of the day,
13340 among other things.
13343 @deftp {Data Type} login-configuration
13344 This is the data type representing the configuration of login.
13349 @cindex message of the day
13350 A file-like object containing the ``message of the day''.
13352 @item @code{allow-empty-passwords?} (default: @code{#t})
13353 Allow empty passwords by default so that first-time users can log in when
13354 the 'root' account has just been created.
13359 @deffn {Scheme Procedure} mingetty-service @var{config}
13360 Return a service to run mingetty according to @var{config}, a
13361 @code{<mingetty-configuration>} object, which specifies the tty to run, among
13365 @deftp {Data Type} mingetty-configuration
13366 This is the data type representing the configuration of Mingetty, which
13367 provides the default implementation of virtual console log-in.
13372 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
13374 @item @code{auto-login} (default: @code{#f})
13375 When true, this field must be a string denoting the user name under
13376 which the system automatically logs in. When it is @code{#f}, a
13377 user name and password must be entered to log in.
13379 @item @code{login-program} (default: @code{#f})
13380 This must be either @code{#f}, in which case the default log-in program
13381 is used (@command{login} from the Shadow tool suite), or a gexp denoting
13382 the name of the log-in program.
13384 @item @code{login-pause?} (default: @code{#f})
13385 When set to @code{#t} in conjunction with @var{auto-login}, the user
13386 will have to press a key before the log-in shell is launched.
13388 @item @code{mingetty} (default: @var{mingetty})
13389 The Mingetty package to use.
13394 @deffn {Scheme Procedure} agetty-service @var{config}
13395 Return a service to run agetty according to @var{config}, an
13396 @code{<agetty-configuration>} object, which specifies the tty to run,
13397 among other things.
13400 @deftp {Data Type} agetty-configuration
13401 This is the data type representing the configuration of agetty, which
13402 implements virtual and serial console log-in. See the @code{agetty(8)}
13403 man page for more information.
13408 The name of the console this agetty runs on, as a string---e.g.,
13409 @code{"ttyS0"}. This argument is optional, it will default to
13410 a reasonable default serial port used by the kernel Linux.
13412 For this, if there is a value for an option @code{agetty.tty} in the kernel
13413 command line, agetty will extract the device name of the serial port
13414 from it and use that.
13416 If not and if there is a value for an option @code{console} with a tty in
13417 the Linux command line, agetty will extract the device name of the
13418 serial port from it and use that.
13420 In both cases, agetty will leave the other serial device settings
13421 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
13424 @item @code{baud-rate} (default: @code{#f})
13425 A string containing a comma-separated list of one or more baud rates, in
13428 @item @code{term} (default: @code{#f})
13429 A string containing the value used for the @env{TERM} environment
13432 @item @code{eight-bits?} (default: @code{#f})
13433 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
13436 @item @code{auto-login} (default: @code{#f})
13437 When passed a login name, as a string, the specified user will be logged
13438 in automatically without prompting for their login name or password.
13440 @item @code{no-reset?} (default: @code{#f})
13441 When @code{#t}, don't reset terminal cflags (control modes).
13443 @item @code{host} (default: @code{#f})
13444 This accepts a string containing the ``login_host'', which will be written
13445 into the @file{/var/run/utmpx} file.
13447 @item @code{remote?} (default: @code{#f})
13448 When set to @code{#t} in conjunction with @var{host}, this will add an
13449 @code{-r} fakehost option to the command line of the login program
13450 specified in @var{login-program}.
13452 @item @code{flow-control?} (default: @code{#f})
13453 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
13455 @item @code{no-issue?} (default: @code{#f})
13456 When set to @code{#t}, the contents of the @file{/etc/issue} file will
13457 not be displayed before presenting the login prompt.
13459 @item @code{init-string} (default: @code{#f})
13460 This accepts a string that will be sent to the tty or modem before
13461 sending anything else. It can be used to initialize a modem.
13463 @item @code{no-clear?} (default: @code{#f})
13464 When set to @code{#t}, agetty will not clear the screen before showing
13467 @item @code{login-program} (default: (file-append shadow "/bin/login"))
13468 This must be either a gexp denoting the name of a log-in program, or
13469 unset, in which case the default value is the @command{login} from the
13472 @item @code{local-line} (default: @code{#f})
13473 Control the CLOCAL line flag. This accepts one of three symbols as
13474 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
13475 the default value chosen by agetty is @code{'auto}.
13477 @item @code{extract-baud?} (default: @code{#f})
13478 When set to @code{#t}, instruct agetty to try to extract the baud rate
13479 from the status messages produced by certain types of modems.
13481 @item @code{skip-login?} (default: @code{#f})
13482 When set to @code{#t}, do not prompt the user for a login name. This
13483 can be used with @var{login-program} field to use non-standard login
13486 @item @code{no-newline?} (default: @code{#f})
13487 When set to @code{#t}, do not print a newline before printing the
13488 @file{/etc/issue} file.
13490 @c Is this dangerous only when used with login-program, or always?
13491 @item @code{login-options} (default: @code{#f})
13492 This option accepts a string containing options that are passed to the
13493 login program. When used with the @var{login-program}, be aware that a
13494 malicious user could try to enter a login name containing embedded
13495 options that could be parsed by the login program.
13497 @item @code{login-pause} (default: @code{#f})
13498 When set to @code{#t}, wait for any key before showing the login prompt.
13499 This can be used in conjunction with @var{auto-login} to save memory by
13500 lazily spawning shells.
13502 @item @code{chroot} (default: @code{#f})
13503 Change root to the specified directory. This option accepts a directory
13506 @item @code{hangup?} (default: @code{#f})
13507 Use the Linux system call @code{vhangup} to do a virtual hangup of the
13508 specified terminal.
13510 @item @code{keep-baud?} (default: @code{#f})
13511 When set to @code{#t}, try to keep the existing baud rate. The baud
13512 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
13515 @item @code{timeout} (default: @code{#f})
13516 When set to an integer value, terminate if no user name could be read
13517 within @var{timeout} seconds.
13519 @item @code{detect-case?} (default: @code{#f})
13520 When set to @code{#t}, turn on support for detecting an uppercase-only
13521 terminal. This setting will detect a login name containing only
13522 uppercase letters as indicating an uppercase-only terminal and turn on
13523 some upper-to-lower case conversions. Note that this will not support
13524 Unicode characters.
13526 @item @code{wait-cr?} (default: @code{#f})
13527 When set to @code{#t}, wait for the user or modem to send a
13528 carriage-return or linefeed character before displaying
13529 @file{/etc/issue} or login prompt. This is typically used with the
13530 @var{init-string} option.
13532 @item @code{no-hints?} (default: @code{#f})
13533 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
13536 @item @code{no-hostname?} (default: @code{#f})
13537 By default, the hostname is printed. When this option is set to
13538 @code{#t}, no hostname will be shown at all.
13540 @item @code{long-hostname?} (default: @code{#f})
13541 By default, the hostname is only printed until the first dot. When this
13542 option is set to @code{#t}, the fully qualified hostname by
13543 @code{gethostname} or @code{getaddrinfo} is shown.
13545 @item @code{erase-characters} (default: @code{#f})
13546 This option accepts a string of additional characters that should be
13547 interpreted as backspace when the user types their login name.
13549 @item @code{kill-characters} (default: @code{#f})
13550 This option accepts a string that should be interpreted to mean ``ignore
13551 all previous characters'' (also called a ``kill'' character) when the user
13552 types their login name.
13554 @item @code{chdir} (default: @code{#f})
13555 This option accepts, as a string, a directory path that will be changed
13558 @item @code{delay} (default: @code{#f})
13559 This options accepts, as an integer, the number of seconds to sleep
13560 before opening the tty and displaying the login prompt.
13562 @item @code{nice} (default: @code{#f})
13563 This option accepts, as an integer, the nice value with which to run the
13564 @command{login} program.
13566 @item @code{extra-options} (default: @code{'()})
13567 This option provides an ``escape hatch'' for the user to provide arbitrary
13568 command-line arguments to @command{agetty} as a list of strings.
13573 @deffn {Scheme Procedure} kmscon-service-type @var{config}
13574 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
13575 according to @var{config}, a @code{<kmscon-configuration>} object, which
13576 specifies the tty to run, among other things.
13579 @deftp {Data Type} kmscon-configuration
13580 This is the data type representing the configuration of Kmscon, which
13581 implements virtual console log-in.
13585 @item @code{virtual-terminal}
13586 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
13588 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
13589 A gexp denoting the name of the log-in program. The default log-in program is
13590 @command{login} from the Shadow tool suite.
13592 @item @code{login-arguments} (default: @code{'("-p")})
13593 A list of arguments to pass to @command{login}.
13595 @item @code{auto-login} (default: @code{#f})
13596 When passed a login name, as a string, the specified user will be logged
13597 in automatically without prompting for their login name or password.
13599 @item @code{hardware-acceleration?} (default: #f)
13600 Whether to use hardware acceleration.
13602 @item @code{kmscon} (default: @var{kmscon})
13603 The Kmscon package to use.
13608 @cindex name service cache daemon
13610 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
13611 [#:name-services '()]
13612 Return a service that runs the libc name service cache daemon (nscd) with the
13613 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
13614 Service Switch}, for an example.
13616 For convenience, the Shepherd service for nscd provides the following actions:
13620 @cindex cache invalidation, nscd
13621 @cindex nscd, cache invalidation
13622 This invalidate the given cache. For instance, running:
13625 herd invalidate nscd hosts
13629 invalidates the host name lookup cache of nscd.
13632 Running @command{herd statistics nscd} displays information about nscd usage
13638 @defvr {Scheme Variable} %nscd-default-configuration
13639 This is the default @code{<nscd-configuration>} value (see below) used
13640 by @code{nscd-service}. It uses the caches defined by
13641 @code{%nscd-default-caches}; see below.
13644 @deftp {Data Type} nscd-configuration
13645 This is the data type representing the name service cache daemon (nscd)
13650 @item @code{name-services} (default: @code{'()})
13651 List of packages denoting @dfn{name services} that must be visible to
13652 the nscd---e.g., @code{(list @var{nss-mdns})}.
13654 @item @code{glibc} (default: @var{glibc})
13655 Package object denoting the GNU C Library providing the @command{nscd}
13658 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
13659 Name of the nscd log file. This is where debugging output goes when
13660 @code{debug-level} is strictly positive.
13662 @item @code{debug-level} (default: @code{0})
13663 Integer denoting the debugging levels. Higher numbers mean that more
13664 debugging output is logged.
13666 @item @code{caches} (default: @code{%nscd-default-caches})
13667 List of @code{<nscd-cache>} objects denoting things to be cached; see
13673 @deftp {Data Type} nscd-cache
13674 Data type representing a cache database of nscd and its parameters.
13678 @item @code{database}
13679 This is a symbol representing the name of the database to be cached.
13680 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
13681 @code{services}, which designate the corresponding NSS database
13682 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
13684 @item @code{positive-time-to-live}
13685 @itemx @code{negative-time-to-live} (default: @code{20})
13686 A number representing the number of seconds during which a positive or
13687 negative lookup result remains in cache.
13689 @item @code{check-files?} (default: @code{#t})
13690 Whether to check for updates of the files corresponding to
13693 For instance, when @var{database} is @code{hosts}, setting this flag
13694 instructs nscd to check for updates in @file{/etc/hosts} and to take
13697 @item @code{persistent?} (default: @code{#t})
13698 Whether the cache should be stored persistently on disk.
13700 @item @code{shared?} (default: @code{#t})
13701 Whether the cache should be shared among users.
13703 @item @code{max-database-size} (default: 32@tie{}MiB)
13704 Maximum size in bytes of the database cache.
13706 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
13707 @c settings, so leave them out.
13712 @defvr {Scheme Variable} %nscd-default-caches
13713 List of @code{<nscd-cache>} objects used by default by
13714 @code{nscd-configuration} (see above).
13716 It enables persistent and aggressive caching of service and host name
13717 lookups. The latter provides better host name lookup performance,
13718 resilience in the face of unreliable name servers, and also better
13719 privacy---often the result of host name lookups is in local cache, so
13720 external name servers do not even need to be queried.
13723 @anchor{syslog-configuration-type}
13726 @deftp {Data Type} syslog-configuration
13727 This data type represents the configuration of the syslog daemon.
13730 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
13731 The syslog daemon to use.
13733 @item @code{config-file} (default: @code{%default-syslog.conf})
13734 The syslog configuration file to use.
13739 @anchor{syslog-service}
13741 @deffn {Scheme Procedure} syslog-service @var{config}
13742 Return a service that runs a syslog daemon according to @var{config}.
13744 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
13745 information on the configuration file syntax.
13748 @defvr {Scheme Variable} guix-service-type
13749 This is the type of the service that runs the build daemon,
13750 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
13751 @code{guix-configuration} record as described below.
13754 @anchor{guix-configuration-type}
13755 @deftp {Data Type} guix-configuration
13756 This data type represents the configuration of the Guix build daemon.
13757 @xref{Invoking guix-daemon}, for more information.
13760 @item @code{guix} (default: @var{guix})
13761 The Guix package to use.
13763 @item @code{build-group} (default: @code{"guixbuild"})
13764 Name of the group for build user accounts.
13766 @item @code{build-accounts} (default: @code{10})
13767 Number of build user accounts to create.
13769 @item @code{authorize-key?} (default: @code{#t})
13770 @cindex substitutes, authorization thereof
13771 Whether to authorize the substitute keys listed in
13772 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
13773 (@pxref{Substitutes}).
13775 @vindex %default-authorized-guix-keys
13776 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
13777 The list of authorized key files for archive imports, as a list of
13778 string-valued gexps (@pxref{Invoking guix archive}). By default, it
13779 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
13781 @item @code{use-substitutes?} (default: @code{#t})
13782 Whether to use substitutes.
13784 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
13785 The list of URLs where to look for substitutes by default.
13787 @item @code{max-silent-time} (default: @code{0})
13788 @itemx @code{timeout} (default: @code{0})
13789 The number of seconds of silence and the number of seconds of activity,
13790 respectively, after which a build process times out. A value of zero
13791 disables the timeout.
13793 @item @code{log-compression} (default: @code{'bzip2})
13794 The type of compression used for build logs---one of @code{gzip},
13795 @code{bzip2}, or @code{none}.
13797 @item @code{extra-options} (default: @code{'()})
13798 List of extra command-line options for @command{guix-daemon}.
13800 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
13801 File where @command{guix-daemon}'s standard output and standard error
13804 @cindex HTTP proxy, for @code{guix-daemon}
13805 @cindex proxy, for @code{guix-daemon} HTTP access
13806 @item @code{http-proxy} (default: @code{#f})
13807 The URL of the HTTP and HTTPS proxy used for downloading fixed-output
13808 derivations and substitutes.
13810 It is also possible to change the daemon's proxy at run time through the
13811 @code{set-http-proxy} action, which restarts it:
13814 herd set-http-proxy guix-daemon http://localhost:8118
13817 To clear the proxy settings, run:
13820 herd set-http-proxy guix-daemon
13823 @item @code{tmpdir} (default: @code{#f})
13824 A directory path where the @command{guix-daemon} will perform builds.
13829 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
13830 Run @var{udev}, which populates the @file{/dev} directory dynamically.
13831 udev rules can be provided as a list of files through the @var{rules}
13832 variable. The procedures @code{udev-rule}, @code{udev-rules-service}
13833 and @code{file->udev-rule} from @code{(gnu services base)} simplify the
13834 creation of such rule files.
13836 The @command{herd rules udev} command, as root, returns the name of the
13837 directory containing all the active udev rules.
13840 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
13841 Return a udev-rule file named @var{file-name} containing the rules
13842 defined by the @var{contents} literal.
13844 In the following example, a rule for a USB device is defined to be
13845 stored in the file @file{90-usb-thing.rules}. The rule runs a script
13846 upon detecting a USB device with a given product identifier.
13849 (define %example-udev-rule
13851 "90-usb-thing.rules"
13852 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
13853 "ATTR@{product@}==\"Example\", "
13854 "RUN+=\"/path/to/script\"")))
13858 @deffn {Scheme Procedure} udev-rules-service [@var{name} @var{rules}] @
13859 [#:groups @var{groups}]
13860 Return a service that extends @code{udev-service-type } with @var{rules}
13861 and @code{account-service-type} with @var{groups} as system groups.
13862 This works by creating a singleton service type
13863 @code{@var{name}-udev-rules}, of which the returned service is an
13866 Here we show how it can be used to extend @code{udev-service-type} with the
13867 previously defined rule @code{%example-udev-rule}.
13873 (cons (udev-rules-service 'usb-thing %example-udev-rule)
13874 %desktop-services)))
13878 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
13879 Return a udev file named @var{file-name} containing the rules defined
13880 within @var{file}, a file-like object.
13882 The following example showcases how we can use an existing rule file.
13885 (use-modules (guix download) ;for url-fetch
13886 (guix packages) ;for origin
13889 (define %android-udev-rules
13891 "51-android-udev.rules"
13892 (let ((version "20170910"))
13895 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
13896 "android-udev-rules/" version "/51-android.rules"))
13898 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
13902 Additionally, Guix package definitions can be included in @var{rules} in
13903 order to extend the udev rules with the definitions found under their
13904 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
13905 @var{file->udev-rule} example, we could have used the
13906 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
13907 packages android)} module.
13909 The following example shows how to use the @var{android-udev-rules}
13910 package so that the Android tool @command{adb} can detect devices
13911 without root privileges. It also details how to create the
13912 @code{adbusers} group, which is required for the proper functioning of
13913 the rules defined within the @code{android-udev-rules} package. To
13914 create such a group, we must define it both as part of the
13915 @code{supplementary-groups} of our @code{user-account} declaration, as
13916 well as in the @var{groups} of the @code{udev-rules-service} procedure.
13919 (use-modules (gnu packages android) ;for android-udev-rules
13920 (gnu system shadow) ;for user-group
13925 (users (cons (user-account
13927 (supplementary-groups
13928 '("adbusers" ;for adb
13929 "wheel" "netdev" "audio" "video")))))
13932 (cons (udev-rules-service 'android android-udev-rules
13933 #:groups '("adbusers"))
13934 %desktop-services)))
13937 @defvr {Scheme Variable} urandom-seed-service-type
13938 Save some entropy in @code{%random-seed-file} to seed @file{/dev/urandom}
13939 when rebooting. It also tries to seed @file{/dev/urandom} from
13940 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
13944 @defvr {Scheme Variable} %random-seed-file
13945 This is the name of the file where some random bytes are saved by
13946 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
13947 It defaults to @file{/var/lib/random-seed}.
13952 @defvr {Scheme Variable} gpm-service-type
13953 This is the type of the service that runs GPM, the @dfn{general-purpose
13954 mouse daemon}, which provides mouse support to the Linux console. GPM
13955 allows users to use the mouse in the console, notably to select, copy,
13958 The value for services of this type must be a @code{gpm-configuration}
13959 (see below). This service is not part of @code{%base-services}.
13962 @deftp {Data Type} gpm-configuration
13963 Data type representing the configuration of GPM.
13966 @item @code{options} (default: @code{%default-gpm-options})
13967 Command-line options passed to @command{gpm}. The default set of
13968 options instruct @command{gpm} to listen to mouse events on
13969 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
13972 @item @code{gpm} (default: @code{gpm})
13973 The GPM package to use.
13978 @anchor{guix-publish-service-type}
13979 @deffn {Scheme Variable} guix-publish-service-type
13980 This is the service type for @command{guix publish} (@pxref{Invoking
13981 guix publish}). Its value must be a @code{guix-publish-configuration}
13982 object, as described below.
13984 This assumes that @file{/etc/guix} already contains a signing key pair as
13985 created by @command{guix archive --generate-key} (@pxref{Invoking guix
13986 archive}). If that is not the case, the service will fail to start.
13989 @deftp {Data Type} guix-publish-configuration
13990 Data type representing the configuration of the @code{guix publish}
13994 @item @code{guix} (default: @code{guix})
13995 The Guix package to use.
13997 @item @code{port} (default: @code{80})
13998 The TCP port to listen for connections.
14000 @item @code{host} (default: @code{"localhost"})
14001 The host (and thus, network interface) to listen to. Use
14002 @code{"0.0.0.0"} to listen on all the network interfaces.
14004 @item @code{compression} (default: @code{'(("gzip" 3))})
14005 This is a list of compression method/level tuple used when compressing
14006 substitutes. For example, to compress all substitutes with @emph{both} lzip
14007 at level 7 and gzip at level 9, write:
14010 '(("lzip" 7) ("gzip" 9))
14013 Level 9 achieves the best compression ratio at the expense of increased CPU
14014 usage, whereas level 1 achieves fast compression.
14016 An empty list disables compression altogether.
14018 @item @code{nar-path} (default: @code{"nar"})
14019 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
14020 publish, @option{--nar-path}}, for details.
14022 @item @code{cache} (default: @code{#f})
14023 When it is @code{#f}, disable caching and instead generate archives on
14024 demand. Otherwise, this should be the name of a directory---e.g.,
14025 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
14026 archives and meta-data ready to be sent. @xref{Invoking guix publish,
14027 @option{--cache}}, for more information on the tradeoffs involved.
14029 @item @code{workers} (default: @code{#f})
14030 When it is an integer, this is the number of worker threads used for
14031 caching; when @code{#f}, the number of processors is used.
14032 @xref{Invoking guix publish, @option{--workers}}, for more information.
14034 @item @code{ttl} (default: @code{#f})
14035 When it is an integer, this denotes the @dfn{time-to-live} in seconds
14036 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
14037 for more information.
14041 @anchor{rngd-service}
14042 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
14043 [#:device "/dev/hwrng"]
14044 Return a service that runs the @command{rngd} program from @var{rng-tools}
14045 to add @var{device} to the kernel's entropy pool. The service will fail if
14046 @var{device} does not exist.
14049 @anchor{pam-limits-service}
14050 @cindex session limits
14055 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
14057 Return a service that installs a configuration file for the
14058 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
14059 @code{pam_limits} module}. The procedure optionally takes a list of
14060 @code{pam-limits-entry} values, which can be used to specify
14061 @code{ulimit} limits and nice priority limits to user sessions.
14063 The following limits definition sets two hard and soft limits for all
14064 login sessions of users in the @code{realtime} group:
14067 (pam-limits-service
14069 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
14070 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
14073 The first entry increases the maximum realtime priority for
14074 non-privileged processes; the second entry lifts any restriction of the
14075 maximum address space that can be locked in memory. These settings are
14076 commonly used for real-time audio systems.
14079 @node Scheduled Job Execution
14080 @subsection Scheduled Job Execution
14084 @cindex scheduling jobs
14085 The @code{(gnu services mcron)} module provides an interface to
14086 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
14087 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
14088 Unix @command{cron} daemon; the main difference is that it is
14089 implemented in Guile Scheme, which provides a lot of flexibility when
14090 specifying the scheduling of jobs and their actions.
14092 The example below defines an operating system that runs the
14093 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
14094 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
14095 well as the @command{mkid} command on behalf of an unprivileged user
14096 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
14097 gexps to introduce job definitions that are passed to mcron
14098 (@pxref{G-Expressions}).
14101 (use-modules (guix) (gnu) (gnu services mcron))
14102 (use-package-modules base idutils)
14104 (define updatedb-job
14105 ;; Run 'updatedb' at 3AM every day. Here we write the
14106 ;; job's action as a Scheme procedure.
14107 #~(job '(next-hour '(3))
14109 (execl (string-append #$findutils "/bin/updatedb")
14111 "--prunepaths=/tmp /var/tmp /gnu/store"))))
14113 (define garbage-collector-job
14114 ;; Collect garbage 5 minutes after midnight every day.
14115 ;; The job's action is a shell command.
14116 #~(job "5 0 * * *" ;Vixie cron syntax
14119 (define idutils-job
14120 ;; Update the index database as user "charlie" at 12:15PM
14121 ;; and 19:15PM. This runs from the user's home directory.
14122 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
14123 (string-append #$idutils "/bin/mkid src")
14128 (services (cons (service mcron-service-type
14129 (mcron-configuration
14130 (jobs (list garbage-collector-job
14136 For more complex jobs defined in Scheme where you need control over the top
14137 level, for instance to introduce a @code{use-modules} form, you can move your
14138 code to a separate program using the @code{program-file} procedure of the
14139 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
14143 (define %battery-alert-job
14144 ;; Beep when the battery percentage falls below %MIN-LEVEL.
14146 '(next-minute (range 0 60 1))
14148 "battery-alert.scm"
14149 (with-imported-modules (source-module-closure
14150 '((guix build utils)))
14152 (use-modules (guix build utils)
14155 (ice-9 textual-ports)
14158 (define %min-level 20)
14160 (setenv "LC_ALL" "C") ;ensure English output
14161 (and-let* ((input-pipe (open-pipe*
14163 #$(file-append acpi "/bin/acpi")))
14164 (output (get-string-all input-pipe))
14165 (m (string-match "Discharging, ([0-9]+)%" output))
14166 (level (string->number (match:substring m 1)))
14167 ((< level %min-level)))
14168 (format #t "warning: Battery level is low (~a%)~%" level)
14169 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
14172 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
14173 for more information on mcron job specifications. Below is the
14174 reference of the mcron service.
14176 On a running system, you can use the @code{schedule} action of the service to
14177 visualize the mcron jobs that will be executed next:
14180 # herd schedule mcron
14184 The example above lists the next five tasks that will be executed, but you can
14185 also specify the number of tasks to display:
14188 # herd schedule mcron 10
14191 @defvr {Scheme Variable} mcron-service-type
14192 This is the type of the @code{mcron} service, whose value is an
14193 @code{mcron-configuration} object.
14195 This service type can be the target of a service extension that provides
14196 it additional job specifications (@pxref{Service Composition}). In
14197 other words, it is possible to define services that provide additional
14201 @deftp {Data Type} mcron-configuration
14202 Data type representing the configuration of mcron.
14205 @item @code{mcron} (default: @var{mcron})
14206 The mcron package to use.
14209 This is a list of gexps (@pxref{G-Expressions}), where each gexp
14210 corresponds to an mcron job specification (@pxref{Syntax, mcron job
14211 specifications,, mcron, GNU@tie{}mcron}).
14217 @subsection Log Rotation
14220 @cindex log rotation
14222 Log files such as those found in @file{/var/log} tend to grow endlessly,
14223 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
14224 their contents in separate files, possibly compressed. The @code{(gnu
14225 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
14226 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
14228 This service is part of @code{%base-services}, and thus enabled by
14229 default, with the default settings, for commonly encountered log files.
14230 The example below shows how to extend it with an additional
14231 @dfn{rotation}, should you need to do that (usually, services that
14232 produce log files already take care of that):
14235 (use-modules (guix) (gnu))
14236 (use-service-modules admin)
14238 (define my-log-files
14239 ;; Log files that I want to rotate.
14240 '("/var/log/something.log" "/var/log/another.log"))
14244 (services (cons (simple-service 'rotate-my-stuff
14245 rottlog-service-type
14246 (list (log-rotation
14248 (files my-log-files))))
14252 @defvr {Scheme Variable} rottlog-service-type
14253 This is the type of the Rottlog service, whose value is a
14254 @code{rottlog-configuration} object.
14256 Other services can extend this one with new @code{log-rotation} objects
14257 (see below), thereby augmenting the set of files to be rotated.
14259 This service type can define mcron jobs (@pxref{Scheduled Job
14260 Execution}) to run the rottlog service.
14263 @deftp {Data Type} rottlog-configuration
14264 Data type representing the configuration of rottlog.
14267 @item @code{rottlog} (default: @code{rottlog})
14268 The Rottlog package to use.
14270 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
14271 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
14272 rottlog, GNU Rot[t]log Manual}).
14274 @item @code{rotations} (default: @code{%default-rotations})
14275 A list of @code{log-rotation} objects as defined below.
14278 This is a list of gexps where each gexp corresponds to an mcron job
14279 specification (@pxref{Scheduled Job Execution}).
14283 @deftp {Data Type} log-rotation
14284 Data type representing the rotation of a group of log files.
14286 Taking an example from the Rottlog manual (@pxref{Period Related File
14287 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
14293 (files '("/var/log/apache/*"))
14294 (options '("storedir apache-archives"
14300 The list of fields is as follows:
14303 @item @code{frequency} (default: @code{'weekly})
14304 The log rotation frequency, a symbol.
14307 The list of files or file glob patterns to rotate.
14309 @item @code{options} (default: @code{'()})
14310 The list of rottlog options for this rotation (@pxref{Configuration
14311 parameters,,, rottlog, GNU Rot[t]lg Manual}).
14313 @item @code{post-rotate} (default: @code{#f})
14314 Either @code{#f} or a gexp to execute once the rotation has completed.
14318 @defvr {Scheme Variable} %default-rotations
14319 Specifies weekly rotation of @code{%rotated-files} and of
14320 @file{/var/log/guix-daemon.log}.
14323 @defvr {Scheme Variable} %rotated-files
14324 The list of syslog-controlled files to be rotated. By default it is:
14325 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
14326 "/var/log/maillog")}.
14329 @node Networking Services
14330 @subsection Networking Services
14332 The @code{(gnu services networking)} module provides services to configure
14333 the network interface.
14335 @cindex DHCP, networking service
14336 @defvr {Scheme Variable} dhcp-client-service-type
14337 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
14338 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
14339 is the DHCP client package to use, @code{isc-dhcp} by default.
14342 @deffn {Scheme Procedure} dhcpd-service-type
14343 This type defines a service that runs a DHCP daemon. To create a
14344 service of this type, you must supply a @code{<dhcpd-configuration>}.
14348 (service dhcpd-service-type
14349 (dhcpd-configuration
14350 (config-file (local-file "my-dhcpd.conf"))
14351 (interfaces '("enp0s25"))))
14355 @deftp {Data Type} dhcpd-configuration
14357 @item @code{package} (default: @code{isc-dhcp})
14358 The package that provides the DHCP daemon. This package is expected to
14359 provide the daemon at @file{sbin/dhcpd} relative to its output
14360 directory. The default package is the
14361 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
14362 @item @code{config-file} (default: @code{#f})
14363 The configuration file to use. This is required. It will be passed to
14364 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
14365 object (@pxref{G-Expressions, file-like objects}). See @code{man
14366 dhcpd.conf} for details on the configuration file syntax.
14367 @item @code{version} (default: @code{"4"})
14368 The DHCP version to use. The ISC DHCP server supports the values ``4'',
14369 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
14370 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
14372 @item @code{run-directory} (default: @code{"/run/dhcpd"})
14373 The run directory to use. At service activation time, this directory
14374 will be created if it does not exist.
14375 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
14376 The PID file to use. This corresponds to the @code{-pf} option of
14377 @code{dhcpd}. See @code{man dhcpd} for details.
14378 @item @code{interfaces} (default: @code{'()})
14379 The names of the network interfaces on which dhcpd should listen for
14380 broadcasts. If this list is not empty, then its elements (which must be
14381 strings) will be appended to the @code{dhcpd} invocation when starting
14382 the daemon. It may not be necessary to explicitly specify any
14383 interfaces here; see @code{man dhcpd} for details.
14387 @defvr {Scheme Variable} static-networking-service-type
14388 This is the type for statically-configured network interfaces.
14389 @c TODO Document <static-networking> data structures.
14392 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
14393 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
14394 [#:requirement @code{'(udev)}]
14395 Return a service that starts @var{interface} with address @var{ip}. If
14396 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
14397 it must be a string specifying the default network gateway. @var{requirement}
14398 can be used to declare a dependency on another service before configuring the
14401 This procedure can be called several times, one for each network
14402 interface of interest. Behind the scenes what it does is extend
14403 @code{static-networking-service-type} with additional network interfaces
14409 (static-networking-service "eno1" "192.168.1.82"
14410 #:gateway "192.168.1.2"
14411 #:name-servers '("192.168.1.2"))
14418 @cindex network management
14419 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
14420 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
14421 management daemon that aims to simplify wired and wireless networking.
14423 This service adds the @var{wicd} package to the global profile, providing
14424 several commands to interact with the daemon and configure networking:
14425 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
14426 and @command{wicd-curses} user interfaces.
14429 @cindex ModemManager
14431 @defvr {Scheme Variable} modem-manager-service-type
14432 This is the service type for the
14433 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
14434 service. The value for this service type is a
14435 @code{modem-manager-configuration} record.
14437 This service is part of @code{%desktop-services} (@pxref{Desktop
14441 @deftp {Data Type} modem-manager-configuration
14442 Data type representing the configuration of ModemManager.
14445 @item @code{modem-manager} (default: @code{modem-manager})
14446 The ModemManager package to use.
14451 @cindex USB_ModeSwitch
14452 @cindex Modeswitching
14454 @defvr {Scheme Variable} usb-modeswitch-service-type
14455 This is the service type for the
14456 @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch} service. The
14457 value for this service type is a @code{usb-modeswitch-configuration} record.
14459 When plugged in, some USB modems (and other USB devices) initially present
14460 themselves as a read-only storage medium and not as a modem. They need to be
14461 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
14462 installs udev rules to automatically modeswitch these devices when they are
14465 This service is part of @code{%desktop-services} (@pxref{Desktop
14469 @deftp {Data Type} usb-modeswitch-configuration
14470 Data type representing the configuration of USB_ModeSwitch.
14473 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
14474 The USB_ModeSwitch package providing the binaries for modeswitching.
14476 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
14477 The package providing the device data and udev rules file used by
14480 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
14481 Which config file to use for the USB_ModeSwitch dispatcher. By default the
14482 config file shipped with USB_ModeSwitch is used which disables logging to
14483 @file{/var/log} among other default settings. If set to @code{#f}, no config
14489 @cindex NetworkManager
14491 @defvr {Scheme Variable} network-manager-service-type
14492 This is the service type for the
14493 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
14494 service. The value for this service type is a
14495 @code{network-manager-configuration} record.
14497 This service is part of @code{%desktop-services} (@pxref{Desktop
14501 @deftp {Data Type} network-manager-configuration
14502 Data type representing the configuration of NetworkManager.
14505 @item @code{network-manager} (default: @code{network-manager})
14506 The NetworkManager package to use.
14508 @item @code{dns} (default: @code{"default"})
14509 Processing mode for DNS, which affects how NetworkManager uses the
14510 @code{resolv.conf} configuration file.
14514 NetworkManager will update @code{resolv.conf} to reflect the nameservers
14515 provided by currently active connections.
14518 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
14519 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
14520 then update @code{resolv.conf} to point to the local nameserver.
14522 With this setting, you can share your network connection. For example when
14523 you want to share your network connection to another laptop @i{via} an
14524 Ethernet cable, you can open @command{nm-connection-editor} and configure the
14525 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
14526 and reestablish the connection (or reboot).
14528 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
14529 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
14530 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
14531 browser on your host system, or connect to the VM @i{via} SSH
14532 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
14533 host-to-guest connection, run this command once:
14536 nmcli connection add type tun \
14537 connection.interface-name tap0 \
14538 tun.mode tap tun.owner $(id -u) \
14539 ipv4.method shared \
14540 ipv4.addresses 172.28.112.1/24
14543 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
14544 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
14545 @command{qemu-system-...}.
14548 NetworkManager will not modify @code{resolv.conf}.
14551 @item @code{vpn-plugins} (default: @code{'()})
14552 This is the list of available plugins for virtual private networks
14553 (VPNs). An example of this is the @code{network-manager-openvpn}
14554 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
14560 @deffn {Scheme Variable} connman-service-type
14561 This is the service type to run @url{https://01.org/connman,Connman},
14562 a network connection manager.
14564 Its value must be an
14565 @code{connman-configuration} record as in this example:
14568 (service connman-service-type
14569 (connman-configuration
14570 (disable-vpn? #t)))
14573 See below for details about @code{connman-configuration}.
14576 @deftp {Data Type} connman-configuration
14577 Data Type representing the configuration of connman.
14580 @item @code{connman} (default: @var{connman})
14581 The connman package to use.
14583 @item @code{disable-vpn?} (default: @code{#f})
14584 When true, disable connman's vpn plugin.
14588 @cindex WPA Supplicant
14589 @defvr {Scheme Variable} wpa-supplicant-service-type
14590 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
14591 supplicant}, an authentication daemon required to authenticate against
14592 encrypted WiFi or ethernet networks.
14595 @deftp {Data Type} wpa-supplicant-configuration
14596 Data type representing the configuration of WPA Supplicant.
14598 It takes the following parameters:
14601 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
14602 The WPA Supplicant package to use.
14604 @item @code{requirement} (default: @code{'(user-processes dbus-system loopback syslogd)}
14605 List of services that should be started before WPA Supplicant starts.
14607 @item @code{dbus?} (default: @code{#t})
14608 Whether to listen for requests on D-Bus.
14610 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
14611 Where to store the PID file.
14613 @item @code{interface} (default: @code{#f})
14614 If this is set, it must specify the name of a network interface that
14615 WPA supplicant will control.
14617 @item @code{config-file} (default: @code{#f})
14618 Optional configuration file to use.
14620 @item @code{extra-options} (default: @code{'()})
14621 List of additional command-line arguments to pass to the daemon.
14625 @cindex hostapd service, for Wi-Fi access points
14626 @cindex Wi-Fi access points, hostapd service
14627 @defvr {Scheme Variable} hostapd-service-type
14628 This is the service type to run the @uref{https://w1.fi/hostapd/,
14629 hostapd} daemon to set up WiFi (IEEE 802.11) access points and
14630 authentication servers. Its associated value must be a
14631 @code{hostapd-configuration} as shown below:
14634 ;; Use wlan1 to run the access point for "My Network".
14635 (service hostapd-service-type
14636 (hostapd-configuration
14637 (interface "wlan1")
14638 (ssid "My Network")
14643 @deftp {Data Type} hostapd-configuration
14644 This data type represents the configuration of the hostapd service, with
14645 the following fields:
14648 @item @code{package} (default: @code{hostapd})
14649 The hostapd package to use.
14651 @item @code{interface} (default: @code{"wlan0"})
14652 The network interface to run the WiFi access point.
14655 The SSID (@dfn{service set identifier}), a string that identifies this
14658 @item @code{broadcast-ssid?} (default: @code{#t})
14659 Whether to broadcast this SSID.
14661 @item @code{channel} (default: @code{1})
14662 The WiFi channel to use.
14664 @item @code{driver} (default: @code{"nl80211"})
14665 The driver interface type. @code{"nl80211"} is used with all Linux
14666 mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
14667 RADIUS server that does # not control any wireless/wired driver.
14669 @item @code{extra-settings} (default: @code{""})
14670 Extra settings to append as-is to the hostapd configuration file. See
14671 @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
14672 configuration file reference.
14676 @defvr {Scheme Variable} simulated-wifi-service-type
14677 This is the type of a service to simulate WiFi networking, which can be
14678 useful in virtual machines for testing purposes. The service loads the
14680 @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
14681 @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
14682 network that can be seen on @code{wlan0}, by default.
14684 The service's value is a @code{hostapd-configuration} record.
14688 @defvr {Scheme Variable} iptables-service-type
14689 This is the service type to set up an iptables configuration. iptables is a
14690 packet filtering framework supported by the Linux kernel. This service
14691 supports configuring iptables for both IPv4 and IPv6. A simple example
14692 configuration rejecting all incoming connections except those to the ssh port
14696 (service iptables-service-type
14697 (iptables-configuration
14698 (ipv4-rules (plain-file "iptables.rules" "*filter
14702 -A INPUT -p tcp --dport 22 -j ACCEPT
14703 -A INPUT -j REJECT --reject-with icmp-port-unreachable
14706 (ipv6-rules (plain-file "ip6tables.rules" "*filter
14710 -A INPUT -p tcp --dport 22 -j ACCEPT
14711 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
14717 @deftp {Data Type} iptables-configuration
14718 The data type representing the configuration of iptables.
14721 @item @code{iptables} (default: @code{iptables})
14722 The iptables package that provides @code{iptables-restore} and
14723 @code{ip6tables-restore}.
14724 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
14725 The iptables rules to use. It will be passed to @code{iptables-restore}.
14726 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
14728 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
14729 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
14730 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
14736 @defvr {Scheme Variable} nftables-service-type
14737 This is the service type to set up a nftables configuration. nftables is a
14738 netfilter project that aims to replace the existing iptables, ip6tables,
14739 arptables and ebtables framework. It provides a new packet filtering
14740 framework, a new user-space utility @command{nft}, and a compatibility layer
14741 for iptables. This service comes with a default ruleset
14742 @code{%default-nftables-ruleset} that rejecting all incomming connections
14743 except those to the ssh port 22. To use it, simply write:
14746 (service nftables-service-type)
14750 @deftp {Data Type} nftables-configuration
14751 The data type representing the configuration of nftables.
14754 @item @code{package} (default: @code{nftables})
14755 The nftables package that provides @command{nft}.
14756 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
14757 The nftables ruleset to use. This may be any ``file-like'' object
14758 (@pxref{G-Expressions, file-like objects}).
14762 @cindex NTP (Network Time Protocol), service
14763 @cindex ntpd, service for the Network Time Protocol daemon
14764 @cindex real time clock
14765 @defvr {Scheme Variable} ntp-service-type
14766 This is the type of the service running the @uref{https://www.ntp.org,
14767 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
14768 system clock synchronized with that of the specified NTP servers.
14770 The value of this service is an @code{ntpd-configuration} object, as described
14774 @deftp {Data Type} ntp-configuration
14775 This is the data type for the NTP service configuration.
14778 @item @code{servers} (default: @code{%ntp-servers})
14779 This is the list of servers (@code{<ntp-server>} records) with which
14780 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
14783 @item @code{allow-large-adjustment?} (default: @code{#t})
14784 This determines whether @command{ntpd} is allowed to make an initial
14785 adjustment of more than 1,000 seconds.
14787 @item @code{ntp} (default: @code{ntp})
14788 The NTP package to use.
14792 @defvr {Scheme Variable} %ntp-servers
14793 List of host names used as the default NTP servers. These are servers of the
14794 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
14797 @deftp {Data Type} ntp-server
14798 The data type representing the configuration of a NTP server.
14801 @item @code{type} (default: @code{'server})
14802 The type of the NTP server, given as a symbol. One of @code{'pool},
14803 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
14805 @item @code{address}
14806 The address of the server, as a string.
14808 @item @code{options}
14809 NTPD options to use with that specific server, given as a list of option names
14810 and/or of option names and values tuples. The following example define a server
14811 to use with the options @option{iburst} and @option{prefer}, as well as
14812 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
14817 (address "some.ntp.server.org")
14818 (options `(iburst (version 3) (maxpoll 16) prefer))))
14824 @deffn {Scheme Procedure} openntpd-service-type
14825 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
14826 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
14827 clock synchronized with that of the given servers.
14831 openntpd-service-type
14832 (openntpd-configuration
14833 (listen-on '("127.0.0.1" "::1"))
14834 (sensor '("udcf0 correction 70000"))
14835 (constraint-from '("www.gnu.org"))
14836 (constraints-from '("https://www.google.com/"))
14837 (allow-large-adjustment? #t)))
14842 @defvr {Scheme Variable} %openntpd-servers
14843 This variable is a list of the server addresses defined in
14844 @code{%ntp-servers}.
14847 @deftp {Data Type} openntpd-configuration
14849 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
14850 The openntpd executable to use.
14851 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
14852 A list of local IP addresses or hostnames the ntpd daemon should listen on.
14853 @item @code{query-from} (default: @code{'()})
14854 A list of local IP address the ntpd daemon should use for outgoing queries.
14855 @item @code{sensor} (default: @code{'()})
14856 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
14857 will listen to each sensor that actually exists and ignore non-existent ones.
14858 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
14860 @item @code{server} (default: @code{'()})
14861 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
14862 @item @code{servers} (default: @code{%openntp-servers})
14863 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
14864 @item @code{constraint-from} (default: @code{'()})
14865 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
14866 This time information is not used for precision but acts as an authenticated
14867 constraint, thereby reducing the impact of unauthenticated NTP
14868 man-in-the-middle attacks.
14869 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
14871 @item @code{constraints-from} (default: @code{'()})
14872 As with constraint from, specify a list of URLs, IP addresses or hostnames of
14873 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
14874 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
14875 @item @code{allow-large-adjustment?} (default: @code{#f})
14876 Determines if @code{ntpd} is allowed to make an initial adjustment of more
14882 @deffn {Scheme variable} inetd-service-type
14883 This service runs the @command{inetd} (@pxref{inetd invocation,,,
14884 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
14885 connections on internet sockets, and lazily starts the specified server
14886 program when a connection is made on one of these sockets.
14888 The value of this service is an @code{inetd-configuration} object. The
14889 following example configures the @command{inetd} daemon to provide the
14890 built-in @command{echo} service, as well as an smtp service which
14891 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
14892 gateway @code{hostname}:
14897 (inetd-configuration
14901 (socket-type 'stream)
14908 (socket-type 'stream)
14912 (program (file-append openssh "/bin/ssh"))
14914 '("ssh" "-qT" "-i" "/path/to/ssh_key"
14915 "-W" "smtp-server:25" "user@@hostname")))))))
14918 See below for more details about @code{inetd-configuration}.
14921 @deftp {Data Type} inetd-configuration
14922 Data type representing the configuration of @command{inetd}.
14925 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
14926 The @command{inetd} executable to use.
14928 @item @code{entries} (default: @code{'()})
14929 A list of @command{inetd} service entries. Each entry should be created
14930 by the @code{inetd-entry} constructor.
14934 @deftp {Data Type} inetd-entry
14935 Data type representing an entry in the @command{inetd} configuration.
14936 Each entry corresponds to a socket where @command{inetd} will listen for
14940 @item @code{node} (default: @code{#f})
14941 Optional string, a comma-separated list of local addresses
14942 @command{inetd} should use when listening for this service.
14943 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
14944 description of all options.
14946 A string, the name must correspond to an entry in @code{/etc/services}.
14947 @item @code{socket-type}
14948 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
14950 @item @code{protocol}
14951 A string, must correspond to an entry in @code{/etc/protocols}.
14952 @item @code{wait?} (default: @code{#t})
14953 Whether @command{inetd} should wait for the server to exit before
14954 listening to new service requests.
14956 A string containing the user (and, optionally, group) name of the user
14957 as whom the server should run. The group name can be specified in a
14958 suffix, separated by a colon or period, i.e.@: @code{"user"},
14959 @code{"user:group"} or @code{"user.group"}.
14960 @item @code{program} (default: @code{"internal"})
14961 The server program which will serve the requests, or @code{"internal"}
14962 if @command{inetd} should use a built-in service.
14963 @item @code{arguments} (default: @code{'()})
14964 A list strings or file-like objects, which are the server program's
14965 arguments, starting with the zeroth argument, i.e.@: the name of the
14966 program itself. For @command{inetd}'s internal services, this entry
14967 must be @code{'()} or @code{'("internal")}.
14970 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
14971 detailed discussion of each configuration field.
14975 @defvr {Scheme Variable} tor-service-type
14976 This is the type for a service that runs the @uref{https://torproject.org,
14977 Tor} anonymous networking daemon. The service is configured using a
14978 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
14979 @code{tor} unprivileged user, which is a member of the @code{tor} group.
14983 @deftp {Data Type} tor-configuration
14985 @item @code{tor} (default: @code{tor})
14986 The package that provides the Tor daemon. This package is expected to provide
14987 the daemon at @file{bin/tor} relative to its output directory. The default
14988 package is the @uref{https://www.torproject.org, Tor Project's}
14991 @item @code{config-file} (default: @code{(plain-file "empty" "")})
14992 The configuration file to use. It will be appended to a default configuration
14993 file, and the final configuration file will be passed to @code{tor} via its
14994 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
14995 file-like objects}). See @code{man tor} for details on the configuration file
14998 @item @code{hidden-services} (default: @code{'()})
14999 The list of @code{<hidden-service>} records to use. For any hidden service
15000 you include in this list, appropriate configuration to enable the hidden
15001 service will be automatically added to the default configuration file. You
15002 may conveniently create @code{<hidden-service>} records using the
15003 @code{tor-hidden-service} procedure described below.
15005 @item @code{socks-socket-type} (default: @code{'tcp})
15006 The default socket type that Tor should use for its SOCKS socket. This must
15007 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
15008 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
15009 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
15010 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
15013 If you want to customize the SOCKS socket in more detail, leave
15014 @code{socks-socket-type} at its default value of @code{'tcp} and use
15015 @code{config-file} to override the default by providing your own
15016 @code{SocksPort} option.
15020 @cindex hidden service
15021 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
15022 Define a new Tor @dfn{hidden service} called @var{name} and implementing
15023 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
15026 '((22 "127.0.0.1:22")
15027 (80 "127.0.0.1:8080"))
15030 In this example, port 22 of the hidden service is mapped to local port 22, and
15031 port 80 is mapped to local port 8080.
15033 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
15034 the @file{hostname} file contains the @code{.onion} host name for the hidden
15037 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
15038 project's documentation} for more information.
15041 The @code{(gnu services rsync)} module provides the following services:
15043 You might want an rsync daemon if you have files that you want available
15044 so anyone (or just yourself) can download existing files or upload new
15047 @deffn {Scheme Variable} rsync-service-type
15048 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
15049 The value for this service type is a
15050 @command{rsync-configuration} record as in this example:
15053 (service rsync-service-type)
15056 See below for details about @code{rsync-configuration}.
15059 @deftp {Data Type} rsync-configuration
15060 Data type representing the configuration for @code{rsync-service}.
15063 @item @code{package} (default: @var{rsync})
15064 @code{rsync} package to use.
15066 @item @code{port-number} (default: @code{873})
15067 TCP port on which @command{rsync} listens for incoming connections. If port
15068 is less than @code{1024} @command{rsync} needs to be started as the
15069 @code{root} user and group.
15071 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
15072 Name of the file where @command{rsync} writes its PID.
15074 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
15075 Name of the file where @command{rsync} writes its lock file.
15077 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
15078 Name of the file where @command{rsync} writes its log file.
15080 @item @code{use-chroot?} (default: @var{#t})
15081 Whether to use chroot for @command{rsync} shared directory.
15083 @item @code{share-path} (default: @file{/srv/rsync})
15084 Location of the @command{rsync} shared directory.
15086 @item @code{share-comment} (default: @code{"Rsync share"})
15087 Comment of the @command{rsync} shared directory.
15089 @item @code{read-only?} (default: @var{#f})
15090 Read-write permissions to shared directory.
15092 @item @code{timeout} (default: @code{300})
15093 I/O timeout in seconds.
15095 @item @code{user} (default: @var{"root"})
15096 Owner of the @code{rsync} process.
15098 @item @code{group} (default: @var{"root"})
15099 Group of the @code{rsync} process.
15101 @item @code{uid} (default: @var{"rsyncd"})
15102 User name or user ID that file transfers to and from that module should take
15103 place as when the daemon was run as @code{root}.
15105 @item @code{gid} (default: @var{"rsyncd"})
15106 Group name or group ID that will be used when accessing the module.
15111 Furthermore, @code{(gnu services ssh)} provides the following services.
15115 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
15116 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
15117 [#:allow-empty-passwords? #f] [#:root-login? #f] @
15118 [#:syslog-output? #t] [#:x11-forwarding? #t] @
15119 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
15120 [#:public-key-authentication? #t] [#:initialize? #t]
15121 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
15122 @var{host-key} must designate a file containing the host key, and readable
15125 When @var{daemonic?} is true, @command{lshd} will detach from the
15126 controlling terminal and log its output to syslogd, unless one sets
15127 @var{syslog-output?} to false. Obviously, it also makes lsh-service
15128 depend on existence of syslogd service. When @var{pid-file?} is true,
15129 @command{lshd} writes its PID to the file called @var{pid-file}.
15131 When @var{initialize?} is true, automatically create the seed and host key
15132 upon service activation if they do not exist yet. This may take long and
15133 require interaction.
15135 When @var{initialize?} is false, it is up to the user to initialize the
15136 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
15137 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
15138 basics,,, lsh, LSH Manual}).
15140 When @var{interfaces} is empty, lshd listens for connections on all the
15141 network interfaces; otherwise, @var{interfaces} must be a list of host names
15144 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
15145 passwords, and @var{root-login?} specifies whether to accept log-ins as
15148 The other options should be self-descriptive.
15153 @deffn {Scheme Variable} openssh-service-type
15154 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
15155 shell daemon, @command{sshd}. Its value must be an
15156 @code{openssh-configuration} record as in this example:
15159 (service openssh-service-type
15160 (openssh-configuration
15161 (x11-forwarding? #t)
15162 (permit-root-login 'without-password)
15164 `(("alice" ,(local-file "alice.pub"))
15165 ("bob" ,(local-file "bob.pub"))))))
15168 See below for details about @code{openssh-configuration}.
15170 This service can be extended with extra authorized keys, as in this
15174 (service-extension openssh-service-type
15175 (const `(("charlie"
15176 ,(local-file "charlie.pub")))))
15180 @deftp {Data Type} openssh-configuration
15181 This is the configuration record for OpenSSH's @command{sshd}.
15184 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
15185 Name of the file where @command{sshd} writes its PID.
15187 @item @code{port-number} (default: @code{22})
15188 TCP port on which @command{sshd} listens for incoming connections.
15190 @item @code{permit-root-login} (default: @code{#f})
15191 This field determines whether and when to allow logins as root. If
15192 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
15193 If it's the symbol @code{'without-password}, then root logins are
15194 permitted but not with password-based authentication.
15196 @item @code{allow-empty-passwords?} (default: @code{#f})
15197 When true, users with empty passwords may log in. When false, they may
15200 @item @code{password-authentication?} (default: @code{#t})
15201 When true, users may log in with their password. When false, they have
15202 other authentication methods.
15204 @item @code{public-key-authentication?} (default: @code{#t})
15205 When true, users may log in using public key authentication. When
15206 false, users have to use other authentication method.
15208 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
15209 This is used only by protocol version 2.
15211 @item @code{x11-forwarding?} (default: @code{#f})
15212 When true, forwarding of X11 graphical client connections is
15213 enabled---in other words, @command{ssh} options @option{-X} and
15214 @option{-Y} will work.
15216 @item @code{allow-agent-forwarding?} (default: @code{#t})
15217 Whether to allow agent forwarding.
15219 @item @code{allow-tcp-forwarding?} (default: @code{#t})
15220 Whether to allow TCP forwarding.
15222 @item @code{gateway-ports?} (default: @code{#f})
15223 Whether to allow gateway ports.
15225 @item @code{challenge-response-authentication?} (default: @code{#f})
15226 Specifies whether challenge response authentication is allowed (e.g.@: via
15229 @item @code{use-pam?} (default: @code{#t})
15230 Enables the Pluggable Authentication Module interface. If set to
15231 @code{#t}, this will enable PAM authentication using
15232 @code{challenge-response-authentication?} and
15233 @code{password-authentication?}, in addition to PAM account and session
15234 module processing for all authentication types.
15236 Because PAM challenge response authentication usually serves an
15237 equivalent role to password authentication, you should disable either
15238 @code{challenge-response-authentication?} or
15239 @code{password-authentication?}.
15241 @item @code{print-last-log?} (default: @code{#t})
15242 Specifies whether @command{sshd} should print the date and time of the
15243 last user login when a user logs in interactively.
15245 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
15246 Configures external subsystems (e.g.@: file transfer daemon).
15248 This is a list of two-element lists, each of which containing the
15249 subsystem name and a command (with optional arguments) to execute upon
15252 The command @command{internal-sftp} implements an in-process SFTP
15253 server. Alternatively, one can specify the @command{sftp-server} command:
15255 (service openssh-service-type
15256 (openssh-configuration
15258 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
15261 @item @code{accepted-environment} (default: @code{'()})
15262 List of strings describing which environment variables may be exported.
15264 Each string gets on its own line. See the @code{AcceptEnv} option in
15265 @code{man sshd_config}.
15267 This example allows ssh-clients to export the @env{COLORTERM} variable.
15268 It is set by terminal emulators, which support colors. You can use it in
15269 your shell's resource file to enable colors for the prompt and commands
15270 if this variable is set.
15273 (service openssh-service-type
15274 (openssh-configuration
15275 (accepted-environment '("COLORTERM"))))
15278 @item @code{authorized-keys} (default: @code{'()})
15279 @cindex authorized keys, SSH
15280 @cindex SSH authorized keys
15281 This is the list of authorized keys. Each element of the list is a user
15282 name followed by one or more file-like objects that represent SSH public
15286 (openssh-configuration
15288 `(("rekado" ,(local-file "rekado.pub"))
15289 ("chris" ,(local-file "chris.pub"))
15290 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
15294 registers the specified public keys for user accounts @code{rekado},
15295 @code{chris}, and @code{root}.
15297 Additional authorized keys can be specified @i{via}
15298 @code{service-extension}.
15300 Note that this does @emph{not} interfere with the use of
15301 @file{~/.ssh/authorized_keys}.
15303 @item @code{log-level} (default: @code{'info})
15304 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
15305 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
15306 page for @file{sshd_config} for the full list of level names.
15308 @item @code{extra-content} (default: @code{""})
15309 This field can be used to append arbitrary text to the configuration file. It
15310 is especially useful for elaborate configurations that cannot be expressed
15311 otherwise. This configuration, for example, would generally disable root
15312 logins, but permit them from one specific IP address:
15315 (openssh-configuration
15317 Match Address 192.168.0.1
15318 PermitRootLogin yes"))
15324 @deffn {Scheme Procedure} dropbear-service [@var{config}]
15325 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
15326 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
15329 For example, to specify a Dropbear service listening on port 1234, add
15330 this call to the operating system's @code{services} field:
15333 (dropbear-service (dropbear-configuration
15334 (port-number 1234)))
15338 @deftp {Data Type} dropbear-configuration
15339 This data type represents the configuration of a Dropbear SSH daemon.
15342 @item @code{dropbear} (default: @var{dropbear})
15343 The Dropbear package to use.
15345 @item @code{port-number} (default: 22)
15346 The TCP port where the daemon waits for incoming connections.
15348 @item @code{syslog-output?} (default: @code{#t})
15349 Whether to enable syslog output.
15351 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
15352 File name of the daemon's PID file.
15354 @item @code{root-login?} (default: @code{#f})
15355 Whether to allow @code{root} logins.
15357 @item @code{allow-empty-passwords?} (default: @code{#f})
15358 Whether to allow empty passwords.
15360 @item @code{password-authentication?} (default: @code{#t})
15361 Whether to enable password-based authentication.
15366 @deffn {Scheme Variable} autossh-service-type
15367 This is the type for the @uref{https://www.harding.motd.ca/autossh,
15368 AutoSSH} program that runs a copy of @command{ssh} and monitors it,
15369 restarting it as necessary should it die or stop passing traffic.
15370 AutoSSH can be run manually from the command-line by passing arguments
15371 to the binary @command{autossh} from the package @code{autossh}, but it
15372 can also be run as a Guix service. This latter use case is documented
15375 AutoSSH can be used to forward local traffic to a remote machine using
15376 an SSH tunnel, and it respects the @file{~/.ssh/config} of the user it
15379 For example, to specify a service running autossh as the user
15380 @code{pino} and forwarding all local connections to port @code{8081} to
15381 @code{remote:8081} using an SSH tunnel, add this call to the operating
15382 system's @code{services} field:
15385 (service autossh-service-type
15386 (autossh-configuration
15388 (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
15392 @deftp {Data Type} autossh-configuration
15393 This data type represents the configuration of an AutoSSH service.
15397 @item @code{user} (default @code{"autossh"})
15398 The user as which the AutoSSH service is to be run.
15399 This assumes that the specified user exists.
15401 @item @code{poll} (default @code{600})
15402 Specifies the connection poll time in seconds.
15404 @item @code{first-poll} (default @code{#f})
15405 Specifies how many seconds AutoSSH waits before the first connection
15406 test. After this first test, polling is resumed at the pace defined in
15407 @code{poll}. When set to @code{#f}, the first poll is not treated
15408 specially and will also use the connection poll specified in
15411 @item @code{gate-time} (default @code{30})
15412 Specifies how many seconds an SSH connection must be active before it is
15413 considered successful.
15415 @item @code{log-level} (default @code{1})
15416 The log level, corresponding to the levels used by syslog---so @code{0}
15417 is the most silent while @code{7} is the chattiest.
15419 @item @code{max-start} (default @code{#f})
15420 The maximum number of times SSH may be (re)started before AutoSSH exits.
15421 When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
15423 @item @code{message} (default @code{""})
15424 The message to append to the echo message sent when testing connections.
15426 @item @code{port} (default @code{"0"})
15427 The ports used for monitoring the connection. When set to @code{"0"},
15428 monitoring is disabled. When set to @code{"@var{n}"} where @var{n} is
15429 a positive integer, ports @var{n} and @var{n}+1 are used for
15430 monitoring the connection, such that port @var{n} is the base
15431 monitoring port and @code{n+1} is the echo port. When set to
15432 @code{"@var{n}:@var{m}"} where @var{n} and @var{m} are positive
15433 integers, the ports @var{n} and @var{m} are used for monitoring the
15434 connection, such that port @var{n} is the base monitoring port and
15435 @var{m} is the echo port.
15437 @item @code{ssh-options} (default @code{'()})
15438 The list of command-line arguments to pass to @command{ssh} when it is
15439 run. Options @option{-f} and @option{-M} are reserved for AutoSSH and
15440 may cause undefined behaviour.
15445 @defvr {Scheme Variable} %facebook-host-aliases
15446 This variable contains a string for use in @file{/etc/hosts}
15447 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
15448 line contains a entry that maps a known server name of the Facebook
15449 on-line service---e.g., @code{www.facebook.com}---to the local
15450 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
15452 This variable is typically used in the @code{hosts-file} field of an
15453 @code{operating-system} declaration (@pxref{operating-system Reference,
15454 @file{/etc/hosts}}):
15457 (use-modules (gnu) (guix))
15460 (host-name "mymachine")
15463 ;; Create a /etc/hosts file with aliases for "localhost"
15464 ;; and "mymachine", as well as for Facebook servers.
15465 (plain-file "hosts"
15466 (string-append (local-host-aliases host-name)
15467 %facebook-host-aliases))))
15470 This mechanism can prevent programs running locally, such as Web
15471 browsers, from accessing Facebook.
15474 The @code{(gnu services avahi)} provides the following definition.
15476 @defvr {Scheme Variable} avahi-service-type
15477 This is the service that runs @command{avahi-daemon}, a system-wide
15478 mDNS/DNS-SD responder that allows for service discovery and
15479 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
15480 Its value must be a @code{zero-configuration} record---see below.
15482 This service extends the name service cache daemon (nscd) so that it can
15483 resolve @code{.local} host names using
15484 @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
15485 Service Switch}, for information on host name resolution.
15487 Additionally, add the @var{avahi} package to the system profile so that
15488 commands such as @command{avahi-browse} are directly usable.
15491 @deftp {Data Type} avahi-configuration
15492 Data type representation the configuration for Avahi.
15496 @item @code{host-name} (default: @code{#f})
15497 If different from @code{#f}, use that as the host name to
15498 publish for this machine; otherwise, use the machine's actual host name.
15500 @item @code{publish?} (default: @code{#t})
15501 When true, allow host names and services to be published (broadcast) over the
15504 @item @code{publish-workstation?} (default: @code{#t})
15505 When true, @command{avahi-daemon} publishes the machine's host name and IP
15506 address via mDNS on the local network. To view the host names published on
15507 your local network, you can run:
15510 avahi-browse _workstation._tcp
15513 @item @code{wide-area?} (default: @code{#f})
15514 When true, DNS-SD over unicast DNS is enabled.
15516 @item @code{ipv4?} (default: @code{#t})
15517 @itemx @code{ipv6?} (default: @code{#t})
15518 These fields determine whether to use IPv4/IPv6 sockets.
15520 @item @code{domains-to-browse} (default: @code{'()})
15521 This is a list of domains to browse.
15525 @deffn {Scheme Variable} openvswitch-service-type
15526 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
15527 service, whose value should be an @code{openvswitch-configuration}
15531 @deftp {Data Type} openvswitch-configuration
15532 Data type representing the configuration of Open vSwitch, a multilayer
15533 virtual switch which is designed to enable massive network automation
15534 through programmatic extension.
15537 @item @code{package} (default: @var{openvswitch})
15538 Package object of the Open vSwitch.
15543 @defvr {Scheme Variable} pagekite-service-type
15544 This is the service type for the @uref{https://pagekite.net, PageKite} service,
15545 a tunneling solution for making localhost servers publicly visible, even from
15546 behind restrictive firewalls or NAT without forwarded ports. The value for
15547 this service type is a @code{pagekite-configuration} record.
15549 Here's an example exposing the local HTTP and SSH daemons:
15552 (service pagekite-service-type
15553 (pagekite-configuration
15554 (kites '("http:@@kitename:localhost:80:@@kitesecret"
15555 "raw/22:@@kitename:localhost:22:@@kitesecret"))
15556 (extra-file "/etc/pagekite.rc")))
15560 @deftp {Data Type} pagekite-configuration
15561 Data type representing the configuration of PageKite.
15564 @item @code{package} (default: @var{pagekite})
15565 Package object of PageKite.
15567 @item @code{kitename} (default: @code{#f})
15568 PageKite name for authenticating to the frontend server.
15570 @item @code{kitesecret} (default: @code{#f})
15571 Shared secret for authenticating to the frontend server. You should probably
15572 put this inside @code{extra-file} instead.
15574 @item @code{frontend} (default: @code{#f})
15575 Connect to the named PageKite frontend server instead of the
15576 @uref{https://pagekite.net,,pagekite.net} service.
15578 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
15579 List of service kites to use. Exposes HTTP on port 80 by default. The format
15580 is @code{proto:kitename:host:port:secret}.
15582 @item @code{extra-file} (default: @code{#f})
15583 Extra configuration file to read, which you are expected to create manually.
15584 Use this to add additional options and manage shared secrets out-of-band.
15589 @node Unattended Upgrades
15590 @subsection Unattended Upgrades
15592 @cindex unattended upgrades
15593 @cindex upgrades, unattended
15594 Guix provides a service to perform @emph{unattended upgrades}:
15595 periodically, the system automatically reconfigures itself from the
15596 latest Guix. Guix System has several properties that make unattended
15601 upgrades are transactional (either the upgrade succeeds or it fails, but
15602 you cannot end up with an ``in-between'' system state);
15604 the upgrade log is kept---you can view it with @command{guix system
15605 list-generations}---and you can roll back to any previous generation,
15606 should the upgraded system fail to behave as intended;
15608 channel code is authenticated so you know you can only run genuine code
15609 (@pxref{Channels});
15611 @command{guix system reconfigure} prevents downgrades, which makes it
15612 immune to @dfn{downgrade attacks}.
15615 To set up unattended upgrades, add an instance of
15616 @code{unattended-upgrade-service-type} like the one below to the list of
15617 your operating system services:
15620 (service unattended-upgrade-service-type)
15623 The defaults above set up weekly upgrades: every Sunday at midnight.
15624 You do not need to provide the operating system configuration file: it
15625 uses @file{/run/current-system/configuration.scm}, which ensures it
15626 always uses your latest configuration---@pxref{provenance-service-type},
15627 for more information about this file.
15629 There are several things that can be configured, in particular the
15630 periodicity and services (daemons) to be restarted upon completion.
15631 When the upgrade is successful, the service takes care of deleting
15632 system generations older that some threshold, as per @command{guix
15633 system delete-generations}. See the reference below for details.
15635 To ensure that upgrades are actually happening, you can run
15636 @command{guix system describe}. To investigate upgrade failures, visit
15637 the unattended upgrade log file (see below).
15639 @defvr {Scheme Variable} unattended-upgrade-service-type
15640 This is the service type for unattended upgrades. It sets up an mcron
15641 job (@pxref{Scheduled Job Execution}) that runs @command{guix system
15642 reconfigure} from the latest version of the specified channels.
15644 Its value must be a @code{unattended-upgrade-configuration} record (see
15648 @deftp {Data Type} unattended-upgrade-configuration
15649 This data type represents the configuration of the unattended upgrade
15650 service. The following fields are available:
15653 @item @code{schedule} (default: @code{"30 01 * * 0"})
15654 This is the schedule of upgrades, expressed as a gexp containing an
15655 mcron job schedule (@pxref{Guile Syntax, mcron job specifications,,
15656 mcron, GNU@tie{}mcron}).
15658 @item @code{channels} (default: @code{#~%default-channels})
15659 This gexp specifies the channels to use for the upgrade
15660 (@pxref{Channels}). By default, the tip of the official @code{guix}
15663 @item @code{operating-system-file} (default: @code{"/run/current-system/configuration.scm"})
15664 This field specifies the operating system configuration file to use.
15665 The default is to reuse the config file of the current configuration.
15667 There are cases, though, where referring to
15668 @file{/run/current-system/configuration.scm} is not enough, for instance
15669 because that file refers to extra files (SSH public keys, extra
15670 configuration files, etc.) @i{via} @code{local-file} and similar
15671 constructs. For those cases, we recommend something along these lines:
15674 (unattended-upgrade-configuration
15675 (operating-system-file
15676 (file-append (local-file "." "config-dir" #:recursive? #t)
15680 The effect here is to import all of the current directory into the
15681 store, and to refer to @file{config.scm} within that directory.
15682 Therefore, uses of @code{local-file} within @file{config.scm} will work
15683 as expected. @xref{G-Expressions}, for information about
15684 @code{local-file} and @code{file-append}.
15686 @item @code{services-to-restart} (default: @code{'(mcron)})
15687 This field specifies the Shepherd services to restart when the upgrade
15690 Those services are restarted right away upon completion, as with
15691 @command{herd restart}, which ensures that the latest version is
15692 running---remember that by default @command{guix system reconfigure}
15693 only restarts services that are not currently running, which is
15694 conservative: it minimizes disruption but leaves outdated services
15697 By default, the @code{mcron} service is restarted. This ensures that
15698 the latest version of the unattended upgrade job will be used next time.
15700 @item @code{system-expiration} (default: @code{(* 3 30 24 3600)})
15701 This is the expiration time in seconds for system generations. System
15702 generations older that this amount of time are deleted with
15703 @command{guix system delete-generations} when an upgrade completes.
15706 The unattended upgrade service does not run the garbage collector. You
15707 will probably want to set up your own mcron job to run @command{guix gc}
15711 @item @code{maximum-duration} (default: @code{3600})
15712 Maximum duration in seconds for the upgrade; past that time, the upgrade
15715 This is primarily useful to ensure the upgrade does not end up
15716 rebuilding or re-downloading ``the world''.
15718 @item @code{log-file} (default: @code{"/var/log/unattended-upgrade.log"})
15719 File where unattended upgrades are logged.
15724 @subsection X Window
15727 @cindex X Window System
15728 @cindex login manager
15729 Support for the X Window graphical display system---specifically
15730 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
15731 there is no @code{xorg-service} procedure. Instead, the X server is
15732 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
15735 @cindex GNOME, login manager
15736 GDM of course allows users to log in into window managers and desktop
15737 environments other than GNOME; for those using GNOME, GDM is required for
15738 features such as automatic screen locking.
15740 @cindex window manager
15741 To use X11, you must install at least one @dfn{window manager}---for
15742 example the @code{windowmaker} or @code{openbox} packages---preferably
15743 by adding it to the @code{packages} field of your operating system
15744 definition (@pxref{operating-system Reference, system-wide packages}).
15746 @defvr {Scheme Variable} gdm-service-type
15747 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
15748 Desktop Manager} (GDM), a program that manages graphical display servers and
15749 handles graphical user logins. Its value must be a @code{gdm-configuration}
15752 @cindex session types (X11)
15753 @cindex X11 session types
15754 GDM looks for @dfn{session types} described by the @file{.desktop} files in
15755 @file{/run/current-system/profile/share/xsessions} and allows users to choose
15756 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
15757 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
15758 set of packages automatically makes them available at the log-in screen.
15760 In addition, @file{~/.xsession} files are honored. When available,
15761 @file{~/.xsession} must be an executable that starts a window manager
15762 and/or other X clients.
15765 @deftp {Data Type} gdm-configuration
15767 @item @code{auto-login?} (default: @code{#f})
15768 @itemx @code{default-user} (default: @code{#f})
15769 When @code{auto-login?} is false, GDM presents a log-in screen.
15771 When @code{auto-login?} is true, GDM logs in directly as
15772 @code{default-user}.
15774 @item @code{debug?} (default: @code{#f})
15775 When true, GDM writes debug messages to its log.
15777 @item @code{gnome-shell-assets} (default: ...)
15778 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
15780 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
15781 Configuration of the Xorg graphical server.
15783 @item @code{xsession} (default: @code{(xinitrc)})
15784 Script to run before starting a X session.
15786 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
15787 File name of the @code{dbus-daemon} executable.
15789 @item @code{gdm} (default: @code{gdm})
15790 The GDM package to use.
15794 @defvr {Scheme Variable} slim-service-type
15795 This is the type for the SLiM graphical login manager for X11.
15797 Like GDM, SLiM looks for session types described by @file{.desktop} files and
15798 allows users to choose a session from the log-in screen using @kbd{F1}. It
15799 also honors @file{~/.xsession} files.
15801 Unlike GDM, SLiM does not spawn the user session on a different VT after
15802 logging in, which means that you can only start one graphical session. If you
15803 want to be able to run multiple graphical sessions at the same time you have
15804 to add multiple SLiM services to your system services. The following example
15805 shows how to replace the default GDM service with two SLiM services on tty7
15809 (use-modules (gnu services)
15810 (gnu services desktop)
15811 (gnu services xorg)
15812 (srfi srfi-1)) ;for 'remove'
15816 (services (cons* (service slim-service-type (slim-configuration
15819 (service slim-service-type (slim-configuration
15822 (remove (lambda (service)
15823 (eq? (service-kind service) gdm-service-type))
15824 %desktop-services))))
15829 @deftp {Data Type} slim-configuration
15830 Data type representing the configuration of @code{slim-service-type}.
15833 @item @code{allow-empty-passwords?} (default: @code{#t})
15834 Whether to allow logins with empty passwords.
15836 @item @code{auto-login?} (default: @code{#f})
15837 @itemx @code{default-user} (default: @code{""})
15838 When @code{auto-login?} is false, SLiM presents a log-in screen.
15840 When @code{auto-login?} is true, SLiM logs in directly as
15841 @code{default-user}.
15843 @item @code{theme} (default: @code{%default-slim-theme})
15844 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
15845 The graphical theme to use and its name.
15847 @item @code{auto-login-session} (default: @code{#f})
15848 If true, this must be the name of the executable to start as the default
15849 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
15851 If false, a session described by one of the available @file{.desktop}
15852 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
15856 You must install at least one window manager in the system profile or in
15857 your user profile. Failing to do that, if @code{auto-login-session} is
15858 false, you will be unable to log in.
15861 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
15862 Configuration of the Xorg graphical server.
15864 @item @code{display} (default @code{":0"})
15865 The display on which to start the Xorg graphical server.
15867 @item @code{vt} (default @code{"vt7"})
15868 The VT on which to start the Xorg graphical server.
15870 @item @code{xauth} (default: @code{xauth})
15871 The XAuth package to use.
15873 @item @code{shepherd} (default: @code{shepherd})
15874 The Shepherd package used when invoking @command{halt} and
15877 @item @code{sessreg} (default: @code{sessreg})
15878 The sessreg package used in order to register the session.
15880 @item @code{slim} (default: @code{slim})
15881 The SLiM package to use.
15885 @defvr {Scheme Variable} %default-theme
15886 @defvrx {Scheme Variable} %default-theme-name
15887 The default SLiM theme and its name.
15891 @deftp {Data Type} sddm-configuration
15892 This is the data type representing the SDDM service configuration.
15895 @item @code{display-server} (default: "x11")
15896 Select display server to use for the greeter. Valid values are
15897 @samp{"x11"} or @samp{"wayland"}.
15899 @item @code{numlock} (default: "on")
15900 Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
15902 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
15903 Command to run when halting.
15905 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
15906 Command to run when rebooting.
15908 @item @code{theme} (default "maldives")
15909 Theme to use. Default themes provided by SDDM are @samp{"elarun"},
15910 @samp{"maldives"} or @samp{"maya"}.
15912 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
15913 Directory to look for themes.
15915 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
15916 Directory to look for faces.
15918 @item @code{default-path} (default "/run/current-system/profile/bin")
15919 Default PATH to use.
15921 @item @code{minimum-uid} (default: 1000)
15922 Minimum UID displayed in SDDM and allowed for log-in.
15924 @item @code{maximum-uid} (default: 2000)
15925 Maximum UID to display in SDDM.
15927 @item @code{remember-last-user?} (default #t)
15928 Remember last user.
15930 @item @code{remember-last-session?} (default #t)
15931 Remember last session.
15933 @item @code{hide-users} (default "")
15934 Usernames to hide from SDDM greeter.
15936 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
15937 Users with shells listed will be hidden from the SDDM greeter.
15939 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
15940 Script to run before starting a wayland session.
15942 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
15943 Directory to look for desktop files starting wayland sessions.
15945 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
15946 Configuration of the Xorg graphical server.
15948 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
15951 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
15954 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
15955 Script to run after starting xorg-server.
15957 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
15958 Script to run before stopping xorg-server.
15960 @item @code{xsession-command} (default: @code{xinitrc})
15961 Script to run before starting a X session.
15963 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
15964 Directory to look for desktop files starting X sessions.
15966 @item @code{minimum-vt} (default: 7)
15969 @item @code{auto-login-user} (default "")
15970 User to use for auto-login.
15972 @item @code{auto-login-session} (default "")
15973 Desktop file to use for auto-login.
15975 @item @code{relogin?} (default #f)
15976 Relogin after logout.
15981 @cindex login manager
15983 @defvr {Scheme Variable} sddm-service-type
15984 This is the type of the service to run the
15985 @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
15986 must be a @code{sddm-configuration} record (see below).
15988 Here's an example use:
15991 (service sddm-service-type
15992 (sddm-configuration
15993 (auto-login-user "alice")
15994 (auto-login-session "xfce.desktop")))
15998 @deftp {Data Type} sddm-configuration
15999 This data type represents the configuration of the SDDM login manager.
16000 The available fields are:
16003 @item @code{sddm} (default: @code{sddm})
16004 The SDDM package to use.
16006 @item @code{display-server} (default: @code{"x11"})
16007 This must be either @code{"x11"} or @code{"wayland"}.
16009 @c FIXME: Add more fields.
16011 @item @code{auto-login-user} (default: @code{""})
16012 If non-empty, this is the user account under which to log in
16015 @item @code{auto-login-session} (default: @code{""})
16016 If non-empty, this is the @file{.desktop} file name to use as the
16017 auto-login session.
16021 @cindex Xorg, configuration
16022 @deftp {Data Type} xorg-configuration
16023 This data type represents the configuration of the Xorg graphical display
16024 server. Note that there is no Xorg service; instead, the X server is started
16025 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
16026 of these display managers aggregates an @code{xorg-configuration} record.
16029 @item @code{modules} (default: @code{%default-xorg-modules})
16030 This is a list of @dfn{module packages} loaded by the Xorg
16031 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
16033 @item @code{fonts} (default: @code{%default-xorg-fonts})
16034 This is a list of font directories to add to the server's @dfn{font path}.
16036 @item @code{drivers} (default: @code{'()})
16037 This must be either the empty list, in which case Xorg chooses a graphics
16038 driver automatically, or a list of driver names that will be tried in this
16039 order---e.g., @code{("modesetting" "vesa")}.
16041 @item @code{resolutions} (default: @code{'()})
16042 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
16043 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
16046 @cindex keyboard layout, for Xorg
16047 @cindex keymap, for Xorg
16048 @item @code{keyboard-layout} (default: @code{#f})
16049 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
16050 English (``qwerty'') for a 105-key PC keyboard.
16052 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
16053 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
16054 information on how to specify the keyboard layout.
16056 @item @code{extra-config} (default: @code{'()})
16057 This is a list of strings or objects appended to the configuration file. It
16058 is used to pass extra text to be added verbatim to the configuration file.
16060 @item @code{server} (default: @code{xorg-server})
16061 This is the package providing the Xorg server.
16063 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
16064 This is the list of command-line arguments to pass to the X server. The
16065 default is @code{-nolisten tcp}.
16069 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
16070 [@var{login-manager-service-type}]
16071 Tell the log-in manager (of type @var{login-manager-service-type}) to use
16072 @var{config}, an @code{<xorg-configuration>} record.
16074 Since the Xorg configuration is embedded in the log-in manager's
16075 configuration---e.g., @code{gdm-configuration}---this procedure provides a
16076 shorthand to set the Xorg configuration.
16079 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
16080 Return a @code{startx} script in which the modules, fonts, etc. specified
16081 in @var{config}, are available. The result should be used in place of
16084 Usually the X server is started by a login manager.
16088 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
16089 Add @var{package}, a package for a screen locker or screen saver whose
16090 command is @var{program}, to the set of setuid programs and add a PAM entry
16091 for it. For example:
16094 (screen-locker-service xlockmore "xlock")
16097 makes the good ol' XlockMore usable.
16101 @node Printing Services
16102 @subsection Printing Services
16104 @cindex printer support with CUPS
16105 The @code{(gnu services cups)} module provides a Guix service definition
16106 for the CUPS printing service. To add printer support to a Guix
16107 system, add a @code{cups-service} to the operating system definition:
16109 @deffn {Scheme Variable} cups-service-type
16110 The service type for the CUPS print server. Its value should be a valid
16111 CUPS configuration (see below). To use the default settings, simply
16114 (service cups-service-type)
16118 The CUPS configuration controls the basic things about your CUPS
16119 installation: what interfaces it listens on, what to do if a print job
16120 fails, how much logging to do, and so on. To actually add a printer,
16121 you have to visit the @url{http://localhost:631} URL, or use a tool such
16122 as GNOME's printer configuration services. By default, configuring a
16123 CUPS service will generate a self-signed certificate if needed, for
16124 secure connections to the print server.
16126 Suppose you want to enable the Web interface of CUPS and also add
16127 support for Epson printers @i{via} the @code{escpr} package and for HP
16128 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
16129 like this (you need to use the @code{(gnu packages cups)} module):
16132 (service cups-service-type
16133 (cups-configuration
16134 (web-interface? #t)
16136 (list cups-filters escpr hplip-minimal))))
16139 Note: If you wish to use the Qt5 based GUI which comes with the hplip
16140 package then it is suggested that you install the @code{hplip} package,
16141 either in your OS configuration file or as your user.
16143 The available configuration parameters follow. Each parameter
16144 definition is preceded by its type; for example, @samp{string-list foo}
16145 indicates that the @code{foo} parameter should be specified as a list of
16146 strings. There is also a way to specify the configuration as a string,
16147 if you have an old @code{cupsd.conf} file that you want to port over
16148 from some other system; see the end for more details.
16150 @c The following documentation was initially generated by
16151 @c (generate-documentation) in (gnu services cups). Manually maintained
16152 @c documentation is better, so we shouldn't hesitate to edit below as
16153 @c needed. However if the change you want to make to this documentation
16154 @c can be done in an automated way, it's probably easier to change
16155 @c (generate-documentation) than to make it below and have to deal with
16156 @c the churn as CUPS updates.
16159 Available @code{cups-configuration} fields are:
16161 @deftypevr {@code{cups-configuration} parameter} package cups
16165 @deftypevr {@code{cups-configuration} parameter} package-list extensions
16166 Drivers and other extensions to the CUPS package.
16169 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
16170 Configuration of where to write logs, what directories to use for print
16171 spools, and related privileged configuration parameters.
16173 Available @code{files-configuration} fields are:
16175 @deftypevr {@code{files-configuration} parameter} log-location access-log
16176 Defines the access log filename. Specifying a blank filename disables
16177 access log generation. The value @code{stderr} causes log entries to be
16178 sent to the standard error file when the scheduler is running in the
16179 foreground, or to the system log daemon when run in the background. The
16180 value @code{syslog} causes log entries to be sent to the system log
16181 daemon. The server name may be included in filenames using the string
16182 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
16184 Defaults to @samp{"/var/log/cups/access_log"}.
16187 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
16188 Where CUPS should cache data.
16190 Defaults to @samp{"/var/cache/cups"}.
16193 @deftypevr {@code{files-configuration} parameter} string config-file-perm
16194 Specifies the permissions for all configuration files that the scheduler
16197 Note that the permissions for the printers.conf file are currently
16198 masked to only allow access from the scheduler user (typically root).
16199 This is done because printer device URIs sometimes contain sensitive
16200 authentication information that should not be generally known on the
16201 system. There is no way to disable this security feature.
16203 Defaults to @samp{"0640"}.
16206 @deftypevr {@code{files-configuration} parameter} log-location error-log
16207 Defines the error log filename. Specifying a blank filename disables
16208 error log generation. The value @code{stderr} causes log entries to be
16209 sent to the standard error file when the scheduler is running in the
16210 foreground, or to the system log daemon when run in the background. The
16211 value @code{syslog} causes log entries to be sent to the system log
16212 daemon. The server name may be included in filenames using the string
16213 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
16215 Defaults to @samp{"/var/log/cups/error_log"}.
16218 @deftypevr {@code{files-configuration} parameter} string fatal-errors
16219 Specifies which errors are fatal, causing the scheduler to exit. The
16224 No errors are fatal.
16227 All of the errors below are fatal.
16230 Browsing initialization errors are fatal, for example failed connections
16231 to the DNS-SD daemon.
16234 Configuration file syntax errors are fatal.
16237 Listen or Port errors are fatal, except for IPv6 failures on the
16238 loopback or @code{any} addresses.
16241 Log file creation or write errors are fatal.
16244 Bad startup file permissions are fatal, for example shared TLS
16245 certificate and key files with world-read permissions.
16248 Defaults to @samp{"all -browse"}.
16251 @deftypevr {@code{files-configuration} parameter} boolean file-device?
16252 Specifies whether the file pseudo-device can be used for new printer
16253 queues. The URI @uref{file:///dev/null} is always allowed.
16255 Defaults to @samp{#f}.
16258 @deftypevr {@code{files-configuration} parameter} string group
16259 Specifies the group name or ID that will be used when executing external
16262 Defaults to @samp{"lp"}.
16265 @deftypevr {@code{files-configuration} parameter} string log-file-perm
16266 Specifies the permissions for all log files that the scheduler writes.
16268 Defaults to @samp{"0644"}.
16271 @deftypevr {@code{files-configuration} parameter} log-location page-log
16272 Defines the page log filename. Specifying a blank filename disables
16273 page log generation. The value @code{stderr} causes log entries to be
16274 sent to the standard error file when the scheduler is running in the
16275 foreground, or to the system log daemon when run in the background. The
16276 value @code{syslog} causes log entries to be sent to the system log
16277 daemon. The server name may be included in filenames using the string
16278 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
16280 Defaults to @samp{"/var/log/cups/page_log"}.
16283 @deftypevr {@code{files-configuration} parameter} string remote-root
16284 Specifies the username that is associated with unauthenticated accesses
16285 by clients claiming to be the root user. The default is @code{remroot}.
16287 Defaults to @samp{"remroot"}.
16290 @deftypevr {@code{files-configuration} parameter} file-name request-root
16291 Specifies the directory that contains print jobs and other HTTP request
16294 Defaults to @samp{"/var/spool/cups"}.
16297 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
16298 Specifies the level of security sandboxing that is applied to print
16299 filters, backends, and other child processes of the scheduler; either
16300 @code{relaxed} or @code{strict}. This directive is currently only
16301 used/supported on macOS.
16303 Defaults to @samp{strict}.
16306 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
16307 Specifies the location of TLS certificates and private keys. CUPS will
16308 look for public and private keys in this directory: @file{.crt} files
16309 for PEM-encoded certificates and corresponding @file{.key} files for
16310 PEM-encoded private keys.
16312 Defaults to @samp{"/etc/cups/ssl"}.
16315 @deftypevr {@code{files-configuration} parameter} file-name server-root
16316 Specifies the directory containing the server configuration files.
16318 Defaults to @samp{"/etc/cups"}.
16321 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
16322 Specifies whether the scheduler calls fsync(2) after writing
16323 configuration or state files.
16325 Defaults to @samp{#f}.
16328 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
16329 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
16332 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
16333 Specifies the directory where temporary files are stored.
16335 Defaults to @samp{"/var/spool/cups/tmp"}.
16338 @deftypevr {@code{files-configuration} parameter} string user
16339 Specifies the user name or ID that is used when running external
16342 Defaults to @samp{"lp"}.
16345 @deftypevr {@code{files-configuration} parameter} string set-env
16346 Set the specified environment variable to be passed to child processes.
16348 Defaults to @samp{"variable value"}.
16352 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
16353 Specifies the logging level for the AccessLog file. The @code{config}
16354 level logs when printers and classes are added, deleted, or modified and
16355 when configuration files are accessed or updated. The @code{actions}
16356 level logs when print jobs are submitted, held, released, modified, or
16357 canceled, and any of the conditions for @code{config}. The @code{all}
16358 level logs all requests.
16360 Defaults to @samp{actions}.
16363 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
16364 Specifies whether to purge job history data automatically when it is no
16365 longer required for quotas.
16367 Defaults to @samp{#f}.
16370 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
16371 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
16372 For example, @samp{"_cups" "_print"} will tell network clients that both
16373 CUPS sharing and IPP Everywhere are supported.
16375 Defaults to @samp{"_cups"}.
16378 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
16379 Specifies which protocols to use for local printer sharing.
16381 Defaults to @samp{dnssd}.
16384 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
16385 Specifies whether the CUPS web interface is advertised.
16387 Defaults to @samp{#f}.
16390 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
16391 Specifies whether shared printers are advertised.
16393 Defaults to @samp{#f}.
16396 @deftypevr {@code{cups-configuration} parameter} string classification
16397 Specifies the security classification of the server. Any valid banner
16398 name can be used, including @samp{"classified"}, @samp{"confidential"},
16399 @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
16400 banner can be omitted to disable secure printing functions.
16402 Defaults to @samp{""}.
16405 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
16406 Specifies whether users may override the classification (cover page) of
16407 individual print jobs using the @code{job-sheets} option.
16409 Defaults to @samp{#f}.
16412 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
16413 Specifies the default type of authentication to use.
16415 Defaults to @samp{Basic}.
16418 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
16419 Specifies whether encryption will be used for authenticated requests.
16421 Defaults to @samp{Required}.
16424 @deftypevr {@code{cups-configuration} parameter} string default-language
16425 Specifies the default language to use for text and web content.
16427 Defaults to @samp{"en"}.
16430 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
16431 Specifies the default paper size for new print queues. @samp{"Auto"}
16432 uses a locale-specific default, while @samp{"None"} specifies there is
16433 no default paper size. Specific size names are typically
16434 @samp{"Letter"} or @samp{"A4"}.
16436 Defaults to @samp{"Auto"}.
16439 @deftypevr {@code{cups-configuration} parameter} string default-policy
16440 Specifies the default access policy to use.
16442 Defaults to @samp{"default"}.
16445 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
16446 Specifies whether local printers are shared by default.
16448 Defaults to @samp{#t}.
16451 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
16452 Specifies the delay for updating of configuration and state files, in
16453 seconds. A value of 0 causes the update to happen as soon as possible,
16454 typically within a few milliseconds.
16456 Defaults to @samp{30}.
16459 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
16460 Specifies what to do when an error occurs. Possible values are
16461 @code{abort-job}, which will discard the failed print job;
16462 @code{retry-job}, which will retry the job at a later time;
16463 @code{retry-current-job}, which retries the failed job immediately; and
16464 @code{stop-printer}, which stops the printer.
16466 Defaults to @samp{stop-printer}.
16469 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
16470 Specifies the maximum cost of filters that are run concurrently, which
16471 can be used to minimize disk, memory, and CPU resource problems. A
16472 limit of 0 disables filter limiting. An average print to a
16473 non-PostScript printer needs a filter limit of about 200. A PostScript
16474 printer needs about half that (100). Setting the limit below these
16475 thresholds will effectively limit the scheduler to printing a single job
16478 Defaults to @samp{0}.
16481 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
16482 Specifies the scheduling priority of filters that are run to print a
16483 job. The nice value ranges from 0, the highest priority, to 19, the
16486 Defaults to @samp{0}.
16489 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
16490 Specifies whether to do reverse lookups on connecting clients. The
16491 @code{double} setting causes @code{cupsd} to verify that the hostname
16492 resolved from the address matches one of the addresses returned for that
16493 hostname. Double lookups also prevent clients with unregistered
16494 addresses from connecting to your server. Only set this option to
16495 @code{#t} or @code{double} if absolutely required.
16497 Defaults to @samp{#f}.
16500 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
16501 Specifies the number of seconds to wait before killing the filters and
16502 backend associated with a canceled or held job.
16504 Defaults to @samp{30}.
16507 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
16508 Specifies the interval between retries of jobs in seconds. This is
16509 typically used for fax queues but can also be used with normal print
16510 queues whose error policy is @code{retry-job} or
16511 @code{retry-current-job}.
16513 Defaults to @samp{30}.
16516 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
16517 Specifies the number of retries that are done for jobs. This is
16518 typically used for fax queues but can also be used with normal print
16519 queues whose error policy is @code{retry-job} or
16520 @code{retry-current-job}.
16522 Defaults to @samp{5}.
16525 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
16526 Specifies whether to support HTTP keep-alive connections.
16528 Defaults to @samp{#t}.
16531 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
16532 Specifies how long an idle client connection remains open, in seconds.
16534 Defaults to @samp{30}.
16537 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
16538 Specifies the maximum size of print files, IPP requests, and HTML form
16539 data. A limit of 0 disables the limit check.
16541 Defaults to @samp{0}.
16544 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
16545 Listens on the specified interfaces for connections. Valid values are
16546 of the form @var{address}:@var{port}, where @var{address} is either an
16547 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
16548 indicate all addresses. Values can also be file names of local UNIX
16549 domain sockets. The Listen directive is similar to the Port directive
16550 but allows you to restrict access to specific interfaces or networks.
16553 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
16554 Specifies the number of pending connections that will be allowed. This
16555 normally only affects very busy servers that have reached the MaxClients
16556 limit, but can also be triggered by large numbers of simultaneous
16557 connections. When the limit is reached, the operating system will
16558 refuse additional connections until the scheduler can accept the pending
16561 Defaults to @samp{128}.
16564 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
16565 Specifies a set of additional access controls.
16567 Available @code{location-access-controls} fields are:
16569 @deftypevr {@code{location-access-controls} parameter} file-name path
16570 Specifies the URI path to which the access control applies.
16573 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
16574 Access controls for all access to this path, in the same format as the
16575 @code{access-controls} of @code{operation-access-control}.
16577 Defaults to @samp{()}.
16580 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
16581 Access controls for method-specific access to this path.
16583 Defaults to @samp{()}.
16585 Available @code{method-access-controls} fields are:
16587 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
16588 If @code{#t}, apply access controls to all methods except the listed
16589 methods. Otherwise apply to only the listed methods.
16591 Defaults to @samp{#f}.
16594 @deftypevr {@code{method-access-controls} parameter} method-list methods
16595 Methods to which this access control applies.
16597 Defaults to @samp{()}.
16600 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
16601 Access control directives, as a list of strings. Each string should be
16602 one directive, such as @samp{"Order allow,deny"}.
16604 Defaults to @samp{()}.
16609 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
16610 Specifies the number of debugging messages that are retained for logging
16611 if an error occurs in a print job. Debug messages are logged regardless
16612 of the LogLevel setting.
16614 Defaults to @samp{100}.
16617 @deftypevr {@code{cups-configuration} parameter} log-level log-level
16618 Specifies the level of logging for the ErrorLog file. The value
16619 @code{none} stops all logging while @code{debug2} logs everything.
16621 Defaults to @samp{info}.
16624 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
16625 Specifies the format of the date and time in the log files. The value
16626 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
16628 Defaults to @samp{standard}.
16631 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
16632 Specifies the maximum number of simultaneous clients that are allowed by
16635 Defaults to @samp{100}.
16638 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
16639 Specifies the maximum number of simultaneous clients that are allowed
16640 from a single address.
16642 Defaults to @samp{100}.
16645 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
16646 Specifies the maximum number of copies that a user can print of each
16649 Defaults to @samp{9999}.
16652 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
16653 Specifies the maximum time a job may remain in the @code{indefinite}
16654 hold state before it is canceled. A value of 0 disables cancellation of
16657 Defaults to @samp{0}.
16660 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
16661 Specifies the maximum number of simultaneous jobs that are allowed. Set
16662 to 0 to allow an unlimited number of jobs.
16664 Defaults to @samp{500}.
16667 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
16668 Specifies the maximum number of simultaneous jobs that are allowed per
16669 printer. A value of 0 allows up to MaxJobs jobs per printer.
16671 Defaults to @samp{0}.
16674 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
16675 Specifies the maximum number of simultaneous jobs that are allowed per
16676 user. A value of 0 allows up to MaxJobs jobs per user.
16678 Defaults to @samp{0}.
16681 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
16682 Specifies the maximum time a job may take to print before it is
16683 canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
16685 Defaults to @samp{10800}.
16688 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
16689 Specifies the maximum size of the log files before they are rotated, in
16690 bytes. The value 0 disables log rotation.
16692 Defaults to @samp{1048576}.
16695 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
16696 Specifies the maximum amount of time to allow between files in a
16697 multiple file print job, in seconds.
16699 Defaults to @samp{300}.
16702 @deftypevr {@code{cups-configuration} parameter} string page-log-format
16703 Specifies the format of PageLog lines. Sequences beginning with percent
16704 (@samp{%}) characters are replaced with the corresponding information,
16705 while all other characters are copied literally. The following percent
16706 sequences are recognized:
16710 insert a single percent character
16713 insert the value of the specified IPP attribute
16716 insert the number of copies for the current page
16719 insert the current page number
16722 insert the current date and time in common log format
16728 insert the printer name
16731 insert the username
16734 A value of the empty string disables page logging. The string @code{%p
16735 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
16736 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
16739 Defaults to @samp{""}.
16742 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
16743 Passes the specified environment variable(s) to child processes; a list
16746 Defaults to @samp{()}.
16749 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
16750 Specifies named access control policies.
16752 Available @code{policy-configuration} fields are:
16754 @deftypevr {@code{policy-configuration} parameter} string name
16755 Name of the policy.
16758 @deftypevr {@code{policy-configuration} parameter} string job-private-access
16759 Specifies an access list for a job's private values. @code{@@ACL} maps
16760 to the printer's requesting-user-name-allowed or
16761 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
16762 owner. @code{@@SYSTEM} maps to the groups listed for the
16763 @code{system-group} field of the @code{files-config} configuration,
16764 which is reified into the @code{cups-files.conf(5)} file. Other
16765 possible elements of the access list include specific user names, and
16766 @code{@@@var{group}} to indicate members of a specific group. The
16767 access list may also be simply @code{all} or @code{default}.
16769 Defaults to @samp{"@@OWNER @@SYSTEM"}.
16772 @deftypevr {@code{policy-configuration} parameter} string job-private-values
16773 Specifies the list of job values to make private, or @code{all},
16774 @code{default}, or @code{none}.
16776 Defaults to @samp{"job-name job-originating-host-name
16777 job-originating-user-name phone"}.
16780 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
16781 Specifies an access list for a subscription's private values.
16782 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
16783 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
16784 owner. @code{@@SYSTEM} maps to the groups listed for the
16785 @code{system-group} field of the @code{files-config} configuration,
16786 which is reified into the @code{cups-files.conf(5)} file. Other
16787 possible elements of the access list include specific user names, and
16788 @code{@@@var{group}} to indicate members of a specific group. The
16789 access list may also be simply @code{all} or @code{default}.
16791 Defaults to @samp{"@@OWNER @@SYSTEM"}.
16794 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
16795 Specifies the list of job values to make private, or @code{all},
16796 @code{default}, or @code{none}.
16798 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
16799 notify-subscriber-user-name notify-user-data"}.
16802 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
16803 Access control by IPP operation.
16805 Defaults to @samp{()}.
16809 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
16810 Specifies whether job files (documents) are preserved after a job is
16811 printed. If a numeric value is specified, job files are preserved for
16812 the indicated number of seconds after printing. Otherwise a boolean
16813 value applies indefinitely.
16815 Defaults to @samp{86400}.
16818 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
16819 Specifies whether the job history is preserved after a job is printed.
16820 If a numeric value is specified, the job history is preserved for the
16821 indicated number of seconds after printing. If @code{#t}, the job
16822 history is preserved until the MaxJobs limit is reached.
16824 Defaults to @samp{#t}.
16827 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
16828 Specifies the amount of time to wait for job completion before
16829 restarting the scheduler.
16831 Defaults to @samp{30}.
16834 @deftypevr {@code{cups-configuration} parameter} string rip-cache
16835 Specifies the maximum amount of memory to use when converting documents
16836 into bitmaps for a printer.
16838 Defaults to @samp{"128m"}.
16841 @deftypevr {@code{cups-configuration} parameter} string server-admin
16842 Specifies the email address of the server administrator.
16844 Defaults to @samp{"root@@localhost.localdomain"}.
16847 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
16848 The ServerAlias directive is used for HTTP Host header validation when
16849 clients connect to the scheduler from external interfaces. Using the
16850 special name @code{*} can expose your system to known browser-based DNS
16851 rebinding attacks, even when accessing sites through a firewall. If the
16852 auto-discovery of alternate names does not work, we recommend listing
16853 each alternate name with a ServerAlias directive instead of using
16856 Defaults to @samp{*}.
16859 @deftypevr {@code{cups-configuration} parameter} string server-name
16860 Specifies the fully-qualified host name of the server.
16862 Defaults to @samp{"localhost"}.
16865 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
16866 Specifies what information is included in the Server header of HTTP
16867 responses. @code{None} disables the Server header. @code{ProductOnly}
16868 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
16869 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
16870 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
16871 the output of the @code{uname} command. @code{Full} reports @code{CUPS
16872 2.0.0 (@var{uname}) IPP/2.0}.
16874 Defaults to @samp{Minimal}.
16877 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
16878 Listens on the specified interfaces for encrypted connections. Valid
16879 values are of the form @var{address}:@var{port}, where @var{address} is
16880 either an IPv6 address enclosed in brackets, an IPv4 address, or
16881 @code{*} to indicate all addresses.
16883 Defaults to @samp{()}.
16886 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
16887 Sets encryption options. By default, CUPS only supports encryption
16888 using TLS v1.0 or higher using known secure cipher suites. Security is
16889 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
16890 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
16891 suites, which are required for some older clients. The @code{AllowSSL3} option
16892 enables SSL v3.0, which is required for some older clients that do not support
16893 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
16894 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
16895 protocol version to TLS v1.1.
16897 Defaults to @samp{()}.
16900 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
16901 Specifies whether the scheduler requires clients to strictly adhere to
16902 the IPP specifications.
16904 Defaults to @samp{#f}.
16907 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
16908 Specifies the HTTP request timeout, in seconds.
16910 Defaults to @samp{300}.
16914 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
16915 Specifies whether the web interface is enabled.
16917 Defaults to @samp{#f}.
16920 At this point you're probably thinking ``oh dear, Guix manual, I like
16921 you but you can stop already with the configuration options''. Indeed.
16922 However, one more point: it could be that you have an existing
16923 @code{cupsd.conf} that you want to use. In that case, you can pass an
16924 @code{opaque-cups-configuration} as the configuration of a
16925 @code{cups-service-type}.
16927 Available @code{opaque-cups-configuration} fields are:
16929 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
16933 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
16934 The contents of the @code{cupsd.conf}, as a string.
16937 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
16938 The contents of the @code{cups-files.conf} file, as a string.
16941 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
16942 strings of the same name, you could instantiate a CUPS service like
16946 (service cups-service-type
16947 (opaque-cups-configuration
16948 (cupsd.conf cupsd.conf)
16949 (cups-files.conf cups-files.conf)))
16953 @node Desktop Services
16954 @subsection Desktop Services
16956 The @code{(gnu services desktop)} module provides services that are
16957 usually useful in the context of a ``desktop'' setup---that is, on a
16958 machine running a graphical display server, possibly with graphical user
16959 interfaces, etc. It also defines services that provide specific desktop
16960 environments like GNOME, Xfce or MATE.
16962 To simplify things, the module defines a variable containing the set of
16963 services that users typically expect on a machine with a graphical
16964 environment and networking:
16966 @defvr {Scheme Variable} %desktop-services
16967 This is a list of services that builds upon @code{%base-services} and
16968 adds or adjusts services for a typical ``desktop'' setup.
16970 In particular, it adds a graphical login manager (@pxref{X Window,
16971 @code{gdm-service-type}}), screen lockers, a network management tool
16972 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
16973 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
16974 energy and color management services, the @code{elogind} login and seat
16975 manager, the Polkit privilege service, the GeoClue location service, the
16976 AccountsService daemon that allows authorized users change system passwords,
16977 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
16978 name service switch service configured to be able to use @code{nss-mdns}
16979 (@pxref{Name Service Switch, mDNS}).
16982 The @code{%desktop-services} variable can be used as the @code{services}
16983 field of an @code{operating-system} declaration (@pxref{operating-system
16984 Reference, @code{services}}).
16986 Additionally, the @code{gnome-desktop-service-type},
16987 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
16988 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
16989 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
16990 services like the backlight adjustment helpers and the power management
16991 utilities are added to the system, extending @code{polkit} and @code{dbus}
16992 appropriately, allowing GNOME to operate with elevated privileges on a
16993 limited number of special-purpose system interfaces. Additionally,
16994 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
16995 metapackage to the system profile. Likewise, adding the Xfce service
16996 not only adds the @code{xfce} metapackage to the system profile, but it
16997 also gives the Thunar file manager the ability to open a ``root-mode''
16998 file management window, if the user authenticates using the
16999 administrator's password via the standard polkit graphical interface.
17000 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
17001 appropriately, allowing MATE to operate with elevated privileges on a
17002 limited number of special-purpose system interfaces. Additionally,
17003 adding a service of type @code{mate-desktop-service-type} adds the MATE
17004 metapackage to the system profile. ``Adding Enlightenment'' means that
17005 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
17006 are set as setuid, allowing Enlightenment's screen locker and other
17007 functionality to work as expected.
17009 The desktop environments in Guix use the Xorg display server by
17010 default. If you'd like to use the newer display server protocol
17011 called Wayland, you need to use the @code{sddm-service} instead of
17012 GDM as the graphical login manager. You should then
17013 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
17014 also try starting GNOME on Wayland manually from a TTY with the
17015 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
17016 gnome-session``. Currently only GNOME has support for Wayland.
17018 @defvr {Scheme Variable} gnome-desktop-service-type
17019 This is the type of the service that adds the @uref{https://www.gnome.org,
17020 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
17021 object (see below).
17023 This service adds the @code{gnome} package to the system profile, and extends
17024 polkit with the actions from @code{gnome-settings-daemon}.
17027 @deftp {Data Type} gnome-desktop-configuration
17028 Configuration record for the GNOME desktop environment.
17031 @item @code{gnome} (default: @code{gnome})
17032 The GNOME package to use.
17036 @defvr {Scheme Variable} xfce-desktop-service-type
17037 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
17038 desktop environment. Its value is an @code{xfce-desktop-configuration} object
17041 This service adds the @code{xfce} package to the system profile, and
17042 extends polkit with the ability for @code{thunar} to manipulate the file
17043 system as root from within a user session, after the user has authenticated
17044 with the administrator's password.
17047 @deftp {Data Type} xfce-desktop-configuration
17048 Configuration record for the Xfce desktop environment.
17051 @item @code{xfce} (default: @code{xfce})
17052 The Xfce package to use.
17056 @deffn {Scheme Variable} mate-desktop-service-type
17057 This is the type of the service that runs the @uref{https://mate-desktop.org/,
17058 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
17059 object (see below).
17061 This service adds the @code{mate} package to the system
17062 profile, and extends polkit with the actions from
17063 @code{mate-settings-daemon}.
17066 @deftp {Data Type} mate-desktop-configuration
17067 Configuration record for the MATE desktop environment.
17070 @item @code{mate} (default: @code{mate})
17071 The MATE package to use.
17075 @deffn {Scheme Variable} enlightenment-desktop-service-type
17076 Return a service that adds the @code{enlightenment} package to the system
17077 profile, and extends dbus with actions from @code{efl}.
17080 @deftp {Data Type} enlightenment-desktop-service-configuration
17082 @item @code{enlightenment} (default: @code{enlightenment})
17083 The enlightenment package to use.
17087 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
17088 the default @code{%desktop-services} variable doesn't include any of
17089 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
17090 @code{%desktop-services} in the @code{services} field of your
17091 @code{operating-system}:
17094 (use-modules (gnu))
17095 (use-service-modules desktop)
17098 ;; cons* adds items to the list given as its last argument.
17099 (services (cons* (service gnome-desktop-service-type)
17100 (service xfce-desktop-service)
17101 %desktop-services))
17105 These desktop environments will then be available as options in the
17106 graphical login window.
17108 The actual service definitions included in @code{%desktop-services} and
17109 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
17110 are described below.
17112 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
17113 Return a service that runs the ``system bus'', using @var{dbus}, with
17114 support for @var{services}.
17116 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
17117 facility. Its system bus is used to allow system services to communicate
17118 and to be notified of system-wide events.
17120 @var{services} must be a list of packages that provide an
17121 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
17122 and policy files. For example, to allow avahi-daemon to use the system bus,
17123 @var{services} must be equal to @code{(list avahi)}.
17126 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
17127 Return a service that runs the @code{elogind} login and
17128 seat management daemon. @uref{https://github.com/elogind/elogind,
17129 Elogind} exposes a D-Bus interface that can be used to know which users
17130 are logged in, know what kind of sessions they have open, suspend the
17131 system, inhibit system suspend, reboot the system, and other tasks.
17133 Elogind handles most system-level power events for a computer, for
17134 example suspending the system when a lid is closed, or shutting it down
17135 when the power button is pressed.
17137 The @var{config} keyword argument specifies the configuration for
17138 elogind, and should be the result of an @code{(elogind-configuration
17139 (@var{parameter} @var{value})...)} invocation. Available parameters and
17140 their default values are:
17143 @item kill-user-processes?
17145 @item kill-only-users
17147 @item kill-exclude-users
17149 @item inhibit-delay-max-seconds
17151 @item handle-power-key
17153 @item handle-suspend-key
17155 @item handle-hibernate-key
17157 @item handle-lid-switch
17159 @item handle-lid-switch-docked
17161 @item power-key-ignore-inhibited?
17163 @item suspend-key-ignore-inhibited?
17165 @item hibernate-key-ignore-inhibited?
17167 @item lid-switch-ignore-inhibited?
17169 @item holdoff-timeout-seconds
17173 @item idle-action-seconds
17175 @item runtime-directory-size-percent
17177 @item runtime-directory-size
17181 @item suspend-state
17182 @code{("mem" "standby" "freeze")}
17185 @item hibernate-state
17187 @item hibernate-mode
17188 @code{("platform" "shutdown")}
17189 @item hybrid-sleep-state
17191 @item hybrid-sleep-mode
17192 @code{("suspend" "platform" "shutdown")}
17196 @deffn {Scheme Procedure} accountsservice-service @
17197 [#:accountsservice @var{accountsservice}]
17198 Return a service that runs AccountsService, a system service that can
17199 list available accounts, change their passwords, and so on.
17200 AccountsService integrates with PolicyKit to enable unprivileged users
17201 to acquire the capability to modify their system configuration.
17202 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
17203 accountsservice web site} for more information.
17205 The @var{accountsservice} keyword argument is the @code{accountsservice}
17206 package to expose as a service.
17209 @deffn {Scheme Procedure} polkit-service @
17210 [#:polkit @var{polkit}]
17211 Return a service that runs the
17212 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
17213 management service}, which allows system administrators to grant access to
17214 privileged operations in a structured way. By querying the Polkit service, a
17215 privileged system component can know when it should grant additional
17216 capabilities to ordinary users. For example, an ordinary user can be granted
17217 the capability to suspend the system if the user is logged in locally.
17220 @defvr {Scheme Variable} polkit-wheel-service
17221 Service that adds the @code{wheel} group as admins to the Polkit
17222 service. This makes it so that users in the @code{wheel} group are queried
17223 for their own passwords when performing administrative actions instead of
17224 @code{root}'s, similar to the behaviour used by @code{sudo}.
17227 @defvr {Scheme Variable} upower-service-type
17228 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
17229 system-wide monitor for power consumption and battery levels, with the given
17230 configuration settings.
17232 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
17233 notably used by GNOME.
17236 @deftp {Data Type} upower-configuration
17237 Data type representation the configuration for UPower.
17241 @item @code{upower} (default: @var{upower})
17242 Package to use for @code{upower}.
17244 @item @code{watts-up-pro?} (default: @code{#f})
17245 Enable the Watts Up Pro device.
17247 @item @code{poll-batteries?} (default: @code{#t})
17248 Enable polling the kernel for battery level changes.
17250 @item @code{ignore-lid?} (default: @code{#f})
17251 Ignore the lid state, this can be useful if it's incorrect on a device.
17253 @item @code{use-percentage-for-policy?} (default: @code{#f})
17254 Whether battery percentage based policy should be used. The default is to use
17255 the time left, change to @code{#t} to use the percentage.
17257 @item @code{percentage-low} (default: @code{10})
17258 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
17259 at which the battery is considered low.
17261 @item @code{percentage-critical} (default: @code{3})
17262 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
17263 at which the battery is considered critical.
17265 @item @code{percentage-action} (default: @code{2})
17266 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
17267 at which action will be taken.
17269 @item @code{time-low} (default: @code{1200})
17270 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
17271 seconds at which the battery is considered low.
17273 @item @code{time-critical} (default: @code{300})
17274 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
17275 seconds at which the battery is considered critical.
17277 @item @code{time-action} (default: @code{120})
17278 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
17279 seconds at which action will be taken.
17281 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
17282 The action taken when @code{percentage-action} or @code{time-action} is
17283 reached (depending on the configuration of @code{use-percentage-for-policy?}).
17285 Possible values are:
17295 @code{'hybrid-sleep}.
17301 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
17302 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
17303 UDisks}, a @dfn{disk management} daemon that provides user interfaces
17304 with notifications and ways to mount/unmount disks. Programs that talk
17305 to UDisks include the @command{udisksctl} command, part of UDisks, and
17306 GNOME Disks. Note that Udisks relies on the @command{mount} command, so
17307 it will only be able to use the file-system utilities installed in the
17308 system profile. For example if you want to be able to mount NTFS
17309 file-systems in read and write fashion, you'll need to have
17310 @code{ntfs-3g} installed system-wide.
17313 @deffn {Scheme Variable} colord-service-type
17314 This is the type of the service that runs @command{colord}, a system
17315 service with a D-Bus
17316 interface to manage the color profiles of input and output devices such as
17317 screens and scanners. It is notably used by the GNOME Color Manager graphical
17318 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
17319 site} for more information.
17322 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
17323 Return a configuration allowing an application to access GeoClue
17324 location data. @var{name} is the Desktop ID of the application, without
17325 the @code{.desktop} part. If @var{allowed?} is true, the application
17326 will have access to location information by default. The boolean
17327 @var{system?} value indicates whether an application is a system component
17328 or not. Finally @var{users} is a list of UIDs of all users for which
17329 this application is allowed location info access. An empty users list
17330 means that all users are allowed.
17333 @cindex scanner access
17334 @deffn {Scheme Procedure} sane-service-type
17335 This service provides access to scanners @i{via}
17336 @uref{http://www.sane-project.org, SANE} by installing the necessary udev
17340 @defvr {Scheme Variable} %standard-geoclue-applications
17341 The standard list of well-known GeoClue application configurations,
17342 granting authority to the GNOME date-and-time utility to ask for the
17343 current location in order to set the time zone, and allowing the
17344 IceCat and Epiphany web browsers to request location information.
17345 IceCat and Epiphany both query the user before allowing a web page to
17346 know the user's location.
17349 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
17350 [#:whitelist '()] @
17351 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
17352 [#:submit-data? #f]
17353 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
17354 [#:submission-nick "geoclue"] @
17355 [#:applications %standard-geoclue-applications]
17356 Return a service that runs the GeoClue location service. This service
17357 provides a D-Bus interface to allow applications to request access to a
17358 user's physical location, and optionally to add information to online
17359 location databases. See
17360 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
17361 web site} for more information.
17364 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
17365 [@w{#:auto-enable? #f}]
17366 Return a service that runs the @command{bluetoothd} daemon, which
17367 manages all the Bluetooth devices and provides a number of D-Bus
17368 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
17369 powered automatically at boot, which can be useful when using a
17370 bluetooth keyboard or mouse.
17372 Users need to be in the @code{lp} group to access the D-Bus service.
17375 @defvr {Scheme Variable} gnome-keyring-service-type
17376 This is the type of the service that adds the
17377 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
17378 value is a @code{gnome-keyring-configuration} object (see below).
17380 This service adds the @code{gnome-keyring} package to the system profile
17381 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
17382 a user's login keyring when they log in or setting its password with passwd.
17385 @deftp {Data Type} gnome-keyring-configuration
17386 Configuration record for the GNOME Keyring service.
17389 @item @code{keyring} (default: @code{gnome-keyring})
17390 The GNOME keyring package to use.
17392 @item @code{pam-services}
17393 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
17394 services to extend, where @var{service} is the name of an existing
17395 service to extend and @var{kind} is one of @code{login} or
17398 If @code{login} is given, it adds an optional
17399 @code{pam_gnome_keyring.so} to the auth block without arguments and to
17400 the session block with @code{auto_start}. If @code{passwd} is given, it
17401 adds an optional @code{pam_gnome_keyring.so} to the password block
17404 By default, this field contains ``gdm-password'' with the value @code{login}
17405 and ``passwd'' is with the value @code{passwd}.
17410 @node Sound Services
17411 @subsection Sound Services
17413 @cindex sound support
17415 @cindex PulseAudio, sound support
17417 The @code{(gnu services sound)} module provides a service to configure the
17418 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
17419 preferred ALSA output driver.
17421 @deffn {Scheme Variable} alsa-service-type
17422 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
17423 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
17424 configuration file. The value for this type is a @command{alsa-configuration}
17425 record as in this example:
17428 (service alsa-service-type)
17431 See below for details about @code{alsa-configuration}.
17434 @deftp {Data Type} alsa-configuration
17435 Data type representing the configuration for @code{alsa-service}.
17438 @item @code{alsa-plugins} (default: @var{alsa-plugins})
17439 @code{alsa-plugins} package to use.
17441 @item @code{pulseaudio?} (default: @var{#t})
17442 Whether ALSA applications should transparently be made to use the
17443 @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
17445 Using PulseAudio allows you to run several sound-producing applications
17446 at the same time and to individual control them @i{via}
17447 @command{pavucontrol}, among other things.
17449 @item @code{extra-options} (default: @var{""})
17450 String to append to the @file{/etc/asound.conf} file.
17455 Individual users who want to override the system configuration of ALSA can do
17456 it with the @file{~/.asoundrc} file:
17459 # In guix, we have to specify the absolute path for plugins.
17461 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
17464 # Routing ALSA to jack:
17465 # <http://jackaudio.org/faq/routing_alsa.html>.
17469 0 system:playback_1
17470 1 system:playback_2
17487 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
17490 @deffn {Scheme Variable} pulseaudio-service-type
17491 This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
17492 sound server. It exists to allow system overrides of the default settings
17493 via @code{pulseaudio-configuration}, see below.
17496 This service overrides per-user configuration files. If you want
17497 PulseAudio to honor configuraton files in @file{~/.config/pulse} you
17498 have to unset the environment variables @env{PULSE_CONFIG} and
17499 @env{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
17503 This service on its own does not ensure, that the @code{pulseaudio} package
17504 exists on your machine. It merely adds configuration files for it, as
17505 detailed below. In the (admittedly unlikely) case, that you find yourself
17506 without a @code{pulseaudio} package, consider enabling it through the
17507 @code{alsa-service-type} above.
17511 @deftp {Data Type} pulseaudio-configuration
17512 Data type representing the configuration for @code{pulseaudio-service}.
17515 @item @var{client-conf} (default: @code{'()})
17516 List of settings to set in @file{client.conf}.
17517 Accepts a list of strings or a symbol-value pairs. A string will be
17518 inserted as-is with a newline added. A pair will be formatted as
17519 ``key = value'', again with a newline added.
17521 @item @var{daemon-conf} (default: @code{'((flat-volumes . no))})
17522 List of settings to set in @file{daemon.conf}, formatted just like
17525 @item @var{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
17526 Script file to use as as @file{default.pa}.
17528 @item @var{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
17529 Script file to use as as @file{system.pa}.
17533 @deffn {Scheme Variable} ladspa-service-type
17534 This service sets the @var{LADSPA_PATH} variable, so that programs, which
17535 respect it, e.g. PulseAudio, can load LADSPA plugins.
17537 The following example will setup the service to enable modules from the
17538 @code{swh-plugins} package:
17541 (service ladspa-service-type
17542 (ladspa-configuration (plugins (list swh-plugins))))
17545 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
17550 @node Database Services
17551 @subsection Database Services
17555 The @code{(gnu services databases)} module provides the following services.
17557 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
17558 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
17559 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
17560 Return a service that runs @var{postgresql}, the PostgreSQL database
17563 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
17564 creates a database cluster with @var{locale} as the default
17565 locale, stored in @var{data-directory}. It then listens on @var{port}.
17567 If the services fails to start, it may be due to an incompatible
17568 cluster already present in @var{data-directory}. Adjust it (or, if you
17569 don't need the cluster anymore, delete @var{data-directory}), then
17570 restart the service.
17572 Peer authentication is used by default and the @code{postgres} user
17573 account has no shell, which prevents the direct execution of @code{psql}
17574 commands as this user. To use @code{psql}, you can temporarily log in
17575 as @code{postgres} using a shell, create a PostgreSQL superuser with the
17576 same name as one of the system users and then create the associated
17580 sudo -u postgres -s /bin/sh
17581 createuser --interactive
17582 createdb $MY_USER_LOGIN # Replace appropriately.
17585 @cindex postgresql extension-packages
17586 Additional extensions are loaded from packages listed in
17587 @var{extension-packages}. Extensions are available at runtime. For instance,
17588 to create a geographic database using the @code{postgis} extension, a user can
17589 configure the postgresql-service as in this example:
17593 (use-package-modules databases geo)
17597 ;; postgresql is required to run `psql' but postgis is not required for
17598 ;; proper operation.
17599 (packages (cons* postgresql %base-packages))
17602 (postgresql-service #:extension-packages (list postgis))
17606 Then the extension becomes visible and you can initialise an empty geographic
17607 database in this way:
17611 > create database postgistest;
17612 > \connect postgistest;
17613 > create extension postgis;
17614 > create extension postgis_topology;
17617 There is no need to add this field for contrib extensions such as hstore or
17618 dblink as they are already loadable by postgresql. This field is only
17619 required to add extensions provided by other packages.
17622 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
17623 Return a service that runs @command{mysqld}, the MySQL or MariaDB
17626 The optional @var{config} argument specifies the configuration for
17627 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
17630 @deftp {Data Type} mysql-configuration
17631 Data type representing the configuration of @var{mysql-service}.
17634 @item @code{mysql} (default: @var{mariadb})
17635 Package object of the MySQL database server, can be either @var{mariadb}
17638 For MySQL, a temporary root password will be displayed at activation time.
17639 For MariaDB, the root password is empty.
17641 @item @code{port} (default: @code{3306})
17642 TCP port on which the database server listens for incoming connections.
17646 @defvr {Scheme Variable} memcached-service-type
17647 This is the service type for the @uref{https://memcached.org/,
17648 Memcached} service, which provides a distributed in memory cache. The
17649 value for the service type is a @code{memcached-configuration} object.
17653 (service memcached-service-type)
17656 @deftp {Data Type} memcached-configuration
17657 Data type representing the configuration of memcached.
17660 @item @code{memcached} (default: @code{memcached})
17661 The Memcached package to use.
17663 @item @code{interfaces} (default: @code{'("0.0.0.0")})
17664 Network interfaces on which to listen.
17666 @item @code{tcp-port} (default: @code{11211})
17667 Port on which to accept connections on,
17669 @item @code{udp-port} (default: @code{11211})
17670 Port on which to accept UDP connections on, a value of 0 will disable
17671 listening on a UDP socket.
17673 @item @code{additional-options} (default: @code{'()})
17674 Additional command line options to pass to @code{memcached}.
17678 @defvr {Scheme Variable} mongodb-service-type
17679 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
17680 The value for the service type is a @code{mongodb-configuration} object.
17684 (service mongodb-service-type)
17687 @deftp {Data Type} mongodb-configuration
17688 Data type representing the configuration of mongodb.
17691 @item @code{mongodb} (default: @code{mongodb})
17692 The MongoDB package to use.
17694 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
17695 The configuration file for MongoDB.
17697 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
17698 This value is used to create the directory, so that it exists and is
17699 owned by the mongodb user. It should match the data-directory which
17700 MongoDB is configured to use through the configuration file.
17704 @defvr {Scheme Variable} redis-service-type
17705 This is the service type for the @uref{https://redis.io/, Redis}
17706 key/value store, whose value is a @code{redis-configuration} object.
17709 @deftp {Data Type} redis-configuration
17710 Data type representing the configuration of redis.
17713 @item @code{redis} (default: @code{redis})
17714 The Redis package to use.
17716 @item @code{bind} (default: @code{"127.0.0.1"})
17717 Network interface on which to listen.
17719 @item @code{port} (default: @code{6379})
17720 Port on which to accept connections on, a value of 0 will disable
17721 listening on a TCP socket.
17723 @item @code{working-directory} (default: @code{"/var/lib/redis"})
17724 Directory in which to store the database and related files.
17728 @node Mail Services
17729 @subsection Mail Services
17733 The @code{(gnu services mail)} module provides Guix service definitions
17734 for email services: IMAP, POP3, and LMTP servers, as well as mail
17735 transport agents (MTAs). Lots of acronyms! These services are detailed
17736 in the subsections below.
17738 @subsubheading Dovecot Service
17740 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
17741 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
17744 By default, Dovecot does not need much configuration; the default
17745 configuration object created by @code{(dovecot-configuration)} will
17746 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
17747 certificate will be generated for TLS-protected connections, though
17748 Dovecot will also listen on cleartext ports by default. There are a
17749 number of options, though, which mail administrators might need to change,
17750 and as is the case with other services, Guix allows the system
17751 administrator to specify these parameters via a uniform Scheme interface.
17753 For example, to specify that mail is located at @code{maildir~/.mail},
17754 one would instantiate the Dovecot service like this:
17757 (dovecot-service #:config
17758 (dovecot-configuration
17759 (mail-location "maildir:~/.mail")))
17762 The available configuration parameters follow. Each parameter
17763 definition is preceded by its type; for example, @samp{string-list foo}
17764 indicates that the @code{foo} parameter should be specified as a list of
17765 strings. There is also a way to specify the configuration as a string,
17766 if you have an old @code{dovecot.conf} file that you want to port over
17767 from some other system; see the end for more details.
17769 @c The following documentation was initially generated by
17770 @c (generate-documentation) in (gnu services mail). Manually maintained
17771 @c documentation is better, so we shouldn't hesitate to edit below as
17772 @c needed. However if the change you want to make to this documentation
17773 @c can be done in an automated way, it's probably easier to change
17774 @c (generate-documentation) than to make it below and have to deal with
17775 @c the churn as dovecot updates.
17777 Available @code{dovecot-configuration} fields are:
17779 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
17780 The dovecot package.
17783 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
17784 A list of IPs or hosts where to listen for connections. @samp{*}
17785 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
17786 interfaces. If you want to specify non-default ports or anything more
17787 complex, customize the address and port fields of the
17788 @samp{inet-listener} of the specific services you are interested in.
17791 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
17792 List of protocols we want to serve. Available protocols include
17793 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
17795 Available @code{protocol-configuration} fields are:
17797 @deftypevr {@code{protocol-configuration} parameter} string name
17798 The name of the protocol.
17801 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
17802 UNIX socket path to the master authentication server to find users.
17803 This is used by imap (for shared users) and lda.
17804 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
17807 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
17808 Space separated list of plugins to load.
17811 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
17812 Maximum number of IMAP connections allowed for a user from each IP
17813 address. NOTE: The username is compared case-sensitively.
17814 Defaults to @samp{10}.
17819 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
17820 List of services to enable. Available services include @samp{imap},
17821 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
17824 Available @code{service-configuration} fields are:
17826 @deftypevr {@code{service-configuration} parameter} string kind
17827 The service kind. Valid values include @code{director},
17828 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
17829 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
17830 @code{tcpwrap}, @code{quota-warning}, or anything else.
17833 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
17834 Listeners for the service. A listener is either a
17835 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
17836 an @code{inet-listener-configuration}.
17837 Defaults to @samp{()}.
17839 Available @code{unix-listener-configuration} fields are:
17841 @deftypevr {@code{unix-listener-configuration} parameter} string path
17842 Path to the file, relative to @code{base-dir} field. This is also used as
17846 @deftypevr {@code{unix-listener-configuration} parameter} string mode
17847 The access mode for the socket.
17848 Defaults to @samp{"0600"}.
17851 @deftypevr {@code{unix-listener-configuration} parameter} string user
17852 The user to own the socket.
17853 Defaults to @samp{""}.
17856 @deftypevr {@code{unix-listener-configuration} parameter} string group
17857 The group to own the socket.
17858 Defaults to @samp{""}.
17862 Available @code{fifo-listener-configuration} fields are:
17864 @deftypevr {@code{fifo-listener-configuration} parameter} string path
17865 Path to the file, relative to @code{base-dir} field. This is also used as
17869 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
17870 The access mode for the socket.
17871 Defaults to @samp{"0600"}.
17874 @deftypevr {@code{fifo-listener-configuration} parameter} string user
17875 The user to own the socket.
17876 Defaults to @samp{""}.
17879 @deftypevr {@code{fifo-listener-configuration} parameter} string group
17880 The group to own the socket.
17881 Defaults to @samp{""}.
17885 Available @code{inet-listener-configuration} fields are:
17887 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
17888 The protocol to listen for.
17891 @deftypevr {@code{inet-listener-configuration} parameter} string address
17892 The address on which to listen, or empty for all addresses.
17893 Defaults to @samp{""}.
17896 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
17897 The port on which to listen.
17900 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
17901 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
17903 Defaults to @samp{#t}.
17908 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
17909 Maximum number of simultaneous client connections per process. Once
17910 this number of connections is received, the next incoming connection
17911 will prompt Dovecot to spawn another process. If set to 0,
17912 @code{default-client-limit} is used instead.
17914 Defaults to @samp{0}.
17918 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
17919 Number of connections to handle before starting a new process.
17920 Typically the only useful values are 0 (unlimited) or 1. 1 is more
17921 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
17922 Defaults to @samp{1}.
17926 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
17927 Maximum number of processes that can exist for this service. If set to
17928 0, @code{default-process-limit} is used instead.
17930 Defaults to @samp{0}.
17934 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
17935 Number of processes to always keep waiting for more connections.
17936 Defaults to @samp{0}.
17939 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
17940 If you set @samp{service-count 0}, you probably need to grow
17942 Defaults to @samp{256000000}.
17947 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
17948 Dict configuration, as created by the @code{dict-configuration}
17951 Available @code{dict-configuration} fields are:
17953 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
17954 A list of key-value pairs that this dict should hold.
17955 Defaults to @samp{()}.
17960 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
17961 A list of passdb configurations, each one created by the
17962 @code{passdb-configuration} constructor.
17964 Available @code{passdb-configuration} fields are:
17966 @deftypevr {@code{passdb-configuration} parameter} string driver
17967 The driver that the passdb should use. Valid values include
17968 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
17970 Defaults to @samp{"pam"}.
17973 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
17974 Space separated list of arguments to the passdb driver.
17975 Defaults to @samp{""}.
17980 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
17981 List of userdb configurations, each one created by the
17982 @code{userdb-configuration} constructor.
17984 Available @code{userdb-configuration} fields are:
17986 @deftypevr {@code{userdb-configuration} parameter} string driver
17987 The driver that the userdb should use. Valid values include
17988 @samp{passwd} and @samp{static}.
17989 Defaults to @samp{"passwd"}.
17992 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
17993 Space separated list of arguments to the userdb driver.
17994 Defaults to @samp{""}.
17997 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
17998 Override fields from passwd.
17999 Defaults to @samp{()}.
18004 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
18005 Plug-in configuration, created by the @code{plugin-configuration}
18009 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
18010 List of namespaces. Each item in the list is created by the
18011 @code{namespace-configuration} constructor.
18013 Available @code{namespace-configuration} fields are:
18015 @deftypevr {@code{namespace-configuration} parameter} string name
18016 Name for this namespace.
18019 @deftypevr {@code{namespace-configuration} parameter} string type
18020 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
18021 Defaults to @samp{"private"}.
18024 @deftypevr {@code{namespace-configuration} parameter} string separator
18025 Hierarchy separator to use. You should use the same separator for
18026 all namespaces or some clients get confused. @samp{/} is usually a good
18027 one. The default however depends on the underlying mail storage
18029 Defaults to @samp{""}.
18032 @deftypevr {@code{namespace-configuration} parameter} string prefix
18033 Prefix required to access this namespace. This needs to be
18034 different for all namespaces. For example @samp{Public/}.
18035 Defaults to @samp{""}.
18038 @deftypevr {@code{namespace-configuration} parameter} string location
18039 Physical location of the mailbox. This is in the same format as
18040 mail_location, which is also the default for it.
18041 Defaults to @samp{""}.
18044 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
18045 There can be only one INBOX, and this setting defines which
18047 Defaults to @samp{#f}.
18050 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
18051 If namespace is hidden, it's not advertised to clients via NAMESPACE
18052 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
18053 useful when converting from another server with different namespaces
18054 which you want to deprecate but still keep working. For example you can
18055 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
18057 Defaults to @samp{#f}.
18060 @deftypevr {@code{namespace-configuration} parameter} boolean list?
18061 Show the mailboxes under this namespace with the LIST command. This
18062 makes the namespace visible for clients that do not support the NAMESPACE
18063 extension. The special @code{children} value lists child mailboxes, but
18064 hides the namespace prefix.
18065 Defaults to @samp{#t}.
18068 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
18069 Namespace handles its own subscriptions. If set to @code{#f}, the
18070 parent namespace handles them. The empty prefix should always have this
18072 Defaults to @samp{#t}.
18075 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
18076 List of predefined mailboxes in this namespace.
18077 Defaults to @samp{()}.
18079 Available @code{mailbox-configuration} fields are:
18081 @deftypevr {@code{mailbox-configuration} parameter} string name
18082 Name for this mailbox.
18085 @deftypevr {@code{mailbox-configuration} parameter} string auto
18086 @samp{create} will automatically create this mailbox.
18087 @samp{subscribe} will both create and subscribe to the mailbox.
18088 Defaults to @samp{"no"}.
18091 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
18092 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
18093 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
18094 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
18095 Defaults to @samp{()}.
18102 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
18103 Base directory where to store runtime data.
18104 Defaults to @samp{"/var/run/dovecot/"}.
18107 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
18108 Greeting message for clients.
18109 Defaults to @samp{"Dovecot ready."}.
18112 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
18113 List of trusted network ranges. Connections from these IPs are
18114 allowed to override their IP addresses and ports (for logging and for
18115 authentication checks). @samp{disable-plaintext-auth} is also ignored
18116 for these networks. Typically you would specify your IMAP proxy servers
18118 Defaults to @samp{()}.
18121 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
18122 List of login access check sockets (e.g.@: tcpwrap).
18123 Defaults to @samp{()}.
18126 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
18127 Show more verbose process titles (in ps). Currently shows user name
18128 and IP address. Useful for seeing who is actually using the IMAP
18129 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
18131 Defaults to @samp{#f}.
18134 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
18135 Should all processes be killed when Dovecot master process shuts down.
18136 Setting this to @code{#f} means that Dovecot can be upgraded without
18137 forcing existing client connections to close (although that could also
18138 be a problem if the upgrade is e.g.@: due to a security fix).
18139 Defaults to @samp{#t}.
18142 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
18143 If non-zero, run mail commands via this many connections to doveadm
18144 server, instead of running them directly in the same process.
18145 Defaults to @samp{0}.
18148 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
18149 UNIX socket or host:port used for connecting to doveadm server.
18150 Defaults to @samp{"doveadm-server"}.
18153 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
18154 List of environment variables that are preserved on Dovecot startup
18155 and passed down to all of its child processes. You can also give
18156 key=value pairs to always set specific settings.
18159 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
18160 Disable LOGIN command and all other plaintext authentications unless
18161 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
18162 matches the local IP (i.e.@: you're connecting from the same computer),
18163 the connection is considered secure and plaintext authentication is
18164 allowed. See also ssl=required setting.
18165 Defaults to @samp{#t}.
18168 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
18169 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
18170 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
18171 for caching to be used.
18172 Defaults to @samp{0}.
18175 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
18176 Time to live for cached data. After TTL expires the cached record
18177 is no longer used, *except* if the main database lookup returns internal
18178 failure. We also try to handle password changes automatically: If
18179 user's previous authentication was successful, but this one wasn't, the
18180 cache isn't used. For now this works only with plaintext
18182 Defaults to @samp{"1 hour"}.
18185 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
18186 TTL for negative hits (user not found, password mismatch).
18187 0 disables caching them completely.
18188 Defaults to @samp{"1 hour"}.
18191 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
18192 List of realms for SASL authentication mechanisms that need them.
18193 You can leave it empty if you don't want to support multiple realms.
18194 Many clients simply use the first one listed here, so keep the default
18196 Defaults to @samp{()}.
18199 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
18200 Default realm/domain to use if none was specified. This is used for
18201 both SASL realms and appending @@domain to username in plaintext
18203 Defaults to @samp{""}.
18206 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
18207 List of allowed characters in username. If the user-given username
18208 contains a character not listed in here, the login automatically fails.
18209 This is just an extra check to make sure user can't exploit any
18210 potential quote escaping vulnerabilities with SQL/LDAP databases. If
18211 you want to allow all characters, set this value to empty.
18212 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
18215 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
18216 Username character translations before it's looked up from
18217 databases. The value contains series of from -> to characters. For
18218 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
18219 translated to @samp{@@}.
18220 Defaults to @samp{""}.
18223 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
18224 Username formatting before it's looked up from databases. You can
18225 use the standard variables here, e.g.@: %Lu would lowercase the username,
18226 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
18227 change the @samp{@@} into @samp{-AT-}. This translation is done after
18228 @samp{auth-username-translation} changes.
18229 Defaults to @samp{"%Lu"}.
18232 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
18233 If you want to allow master users to log in by specifying the master
18234 username within the normal username string (i.e.@: not using SASL
18235 mechanism's support for it), you can specify the separator character
18236 here. The format is then <username><separator><master username>.
18237 UW-IMAP uses @samp{*} as the separator, so that could be a good
18239 Defaults to @samp{""}.
18242 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
18243 Username to use for users logging in with ANONYMOUS SASL
18245 Defaults to @samp{"anonymous"}.
18248 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
18249 Maximum number of dovecot-auth worker processes. They're used to
18250 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
18251 They're automatically created and destroyed as needed.
18252 Defaults to @samp{30}.
18255 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
18256 Host name to use in GSSAPI principal names. The default is to use
18257 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
18258 allow all keytab entries.
18259 Defaults to @samp{""}.
18262 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
18263 Kerberos keytab to use for the GSSAPI mechanism. Will use the
18264 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
18265 need to change the auth service to run as root to be able to read this
18267 Defaults to @samp{""}.
18270 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
18271 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
18272 and @samp{ntlm-auth} helper.
18273 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
18274 Defaults to @samp{#f}.
18277 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
18278 Path for Samba's @samp{ntlm-auth} helper binary.
18279 Defaults to @samp{"/usr/bin/ntlm_auth"}.
18282 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
18283 Time to delay before replying to failed authentications.
18284 Defaults to @samp{"2 secs"}.
18287 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
18288 Require a valid SSL client certificate or the authentication
18290 Defaults to @samp{#f}.
18293 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
18294 Take the username from client's SSL certificate, using
18295 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
18297 Defaults to @samp{#f}.
18300 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
18301 List of wanted authentication mechanisms. Supported mechanisms are:
18302 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
18303 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
18304 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
18305 @samp{disable-plaintext-auth} setting.
18308 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
18309 List of IPs or hostnames to all director servers, including ourself.
18310 Ports can be specified as ip:port. The default port is the same as what
18311 director service's @samp{inet-listener} is using.
18312 Defaults to @samp{()}.
18315 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
18316 List of IPs or hostnames to all backend mail servers. Ranges are
18317 allowed too, like 10.0.0.10-10.0.0.30.
18318 Defaults to @samp{()}.
18321 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
18322 How long to redirect users to a specific server after it no longer
18323 has any connections.
18324 Defaults to @samp{"15 min"}.
18327 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
18328 How the username is translated before being hashed. Useful values
18329 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
18330 are shared within domain.
18331 Defaults to @samp{"%Lu"}.
18334 @deftypevr {@code{dovecot-configuration} parameter} string log-path
18335 Log file to use for error messages. @samp{syslog} logs to syslog,
18336 @samp{/dev/stderr} logs to stderr.
18337 Defaults to @samp{"syslog"}.
18340 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
18341 Log file to use for informational messages. Defaults to
18343 Defaults to @samp{""}.
18346 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
18347 Log file to use for debug messages. Defaults to
18348 @samp{info-log-path}.
18349 Defaults to @samp{""}.
18352 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
18353 Syslog facility to use if you're logging to syslog. Usually if you
18354 don't want to use @samp{mail}, you'll use local0..local7. Also other
18355 standard facilities are supported.
18356 Defaults to @samp{"mail"}.
18359 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
18360 Log unsuccessful authentication attempts and the reasons why they
18362 Defaults to @samp{#f}.
18365 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
18366 In case of password mismatches, log the attempted password. Valid
18367 values are no, plain and sha1. sha1 can be useful for detecting brute
18368 force password attempts vs. user simply trying the same password over
18369 and over again. You can also truncate the value to n chars by appending
18370 ":n" (e.g.@: sha1:6).
18371 Defaults to @samp{"no"}.
18374 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
18375 Even more verbose logging for debugging purposes. Shows for example
18377 Defaults to @samp{#f}.
18380 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
18381 In case of password mismatches, log the passwords and used scheme so
18382 the problem can be debugged. Enabling this also enables
18384 Defaults to @samp{#f}.
18387 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
18388 Enable mail process debugging. This can help you figure out why
18389 Dovecot isn't finding your mails.
18390 Defaults to @samp{#f}.
18393 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
18394 Show protocol level SSL errors.
18395 Defaults to @samp{#f}.
18398 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
18399 Prefix for each line written to log file. % codes are in
18400 strftime(3) format.
18401 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
18404 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
18405 List of elements we want to log. The elements which have a
18406 non-empty variable value are joined together to form a comma-separated
18410 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
18411 Login log format. %s contains @samp{login-log-format-elements}
18412 string, %$ contains the data we want to log.
18413 Defaults to @samp{"%$: %s"}.
18416 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
18417 Log prefix for mail processes. See doc/wiki/Variables.txt for list
18418 of possible variables you can use.
18419 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
18422 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
18423 Format to use for logging mail deliveries. You can use variables:
18426 Delivery status message (e.g.@: @samp{saved to INBOX})
18438 Defaults to @samp{"msgid=%m: %$"}.
18441 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
18442 Location for users' mailboxes. The default is empty, which means
18443 that Dovecot tries to find the mailboxes automatically. This won't work
18444 if the user doesn't yet have any mail, so you should explicitly tell
18445 Dovecot the full location.
18447 If you're using mbox, giving a path to the INBOX
18448 file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
18449 where the other mailboxes are kept. This is called the @emph{root mail
18450 directory}, and it must be the first path given in the
18451 @samp{mail-location} setting.
18453 There are a few special variables you can use, e.g.:
18459 user part in user@@domain, same as %u if there's no domain
18461 domain part in user@@domain, empty if there's no domain
18466 See doc/wiki/Variables.txt for full list. Some examples:
18468 @item maildir:~/Maildir
18469 @item mbox:~/mail:INBOX=/var/mail/%u
18470 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
18472 Defaults to @samp{""}.
18475 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
18476 System user and group used to access mails. If you use multiple,
18477 userdb can override these by returning uid or gid fields. You can use
18478 either numbers or names. <doc/wiki/UserIds.txt>.
18479 Defaults to @samp{""}.
18482 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
18484 Defaults to @samp{""}.
18487 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
18488 Group to enable temporarily for privileged operations. Currently
18489 this is used only with INBOX when either its initial creation or
18490 dotlocking fails. Typically this is set to @samp{"mail"} to give access to
18492 Defaults to @samp{""}.
18495 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
18496 Grant access to these supplementary groups for mail processes.
18497 Typically these are used to set up access to shared mailboxes. Note
18498 that it may be dangerous to set these if users can create symlinks
18499 (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
18500 could allow a user to delete others' mailboxes, or @code{ln -s
18501 /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
18505 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
18506 Allow full file system access to clients. There's no access checks
18507 other than what the operating system does for the active UID/GID. It
18508 works with both maildir and mboxes, allowing you to prefix mailboxes
18509 names with e.g.@: @file{/path/} or @file{~user/}.
18510 Defaults to @samp{#f}.
18513 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
18514 Don't use @code{mmap()} at all. This is required if you store indexes to
18515 shared file systems (NFS or clustered file system).
18516 Defaults to @samp{#f}.
18519 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
18520 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
18521 supports @samp{O_EXCL} since version 3, so this should be safe to use
18522 nowadays by default.
18523 Defaults to @samp{#t}.
18526 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
18527 When to use fsync() or fdatasync() calls:
18530 Whenever necessary to avoid losing important data
18532 Useful with e.g.@: NFS when @code{write()}s are delayed
18534 Never use it (best performance, but crashes can lose data).
18536 Defaults to @samp{"optimized"}.
18539 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
18540 Mail storage exists in NFS. Set this to yes to make Dovecot flush
18541 NFS caches whenever needed. If you're using only a single mail server
18543 Defaults to @samp{#f}.
18546 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
18547 Mail index files also exist in NFS. Setting this to yes requires
18548 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
18549 Defaults to @samp{#f}.
18552 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
18553 Locking method for index files. Alternatives are fcntl, flock and
18554 dotlock. Dotlocking uses some tricks which may create more disk I/O
18555 than other locking methods. NFS users: flock doesn't work, remember to
18556 change @samp{mmap-disable}.
18557 Defaults to @samp{"fcntl"}.
18560 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
18561 Directory in which LDA/LMTP temporarily stores incoming mails >128
18563 Defaults to @samp{"/tmp"}.
18566 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
18567 Valid UID range for users. This is mostly to make sure that users can't
18568 log in as daemons or other system users. Note that denying root logins is
18569 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
18571 Defaults to @samp{500}.
18574 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
18576 Defaults to @samp{0}.
18579 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
18580 Valid GID range for users. Users having non-valid GID as primary group ID
18581 aren't allowed to log in. If user belongs to supplementary groups with
18582 non-valid GIDs, those groups are not set.
18583 Defaults to @samp{1}.
18586 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
18588 Defaults to @samp{0}.
18591 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
18592 Maximum allowed length for mail keyword name. It's only forced when
18593 trying to create new keywords.
18594 Defaults to @samp{50}.
18597 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
18598 List of directories under which chrooting is allowed for mail
18599 processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
18600 too). This setting doesn't affect @samp{login-chroot}
18601 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
18602 @samp{/./} in home dirs are ignored. WARNING: Never add directories here
18603 which local users can modify, that may lead to root exploit. Usually
18604 this should be done only if you don't allow shell access for users.
18605 <doc/wiki/Chrooting.txt>.
18606 Defaults to @samp{()}.
18609 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
18610 Default chroot directory for mail processes. This can be overridden
18611 for specific users in user database by giving @samp{/./} in user's home
18612 directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
18613 there is no real need to do chrooting, Dovecot doesn't allow users to
18614 access files outside their mail directory anyway. If your home
18615 directories are prefixed with the chroot directory, append @samp{/.} to
18616 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
18617 Defaults to @samp{""}.
18620 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
18621 UNIX socket path to master authentication server to find users.
18622 This is used by imap (for shared users) and lda.
18623 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
18626 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
18627 Directory where to look up mail plugins.
18628 Defaults to @samp{"/usr/lib/dovecot"}.
18631 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
18632 List of plugins to load for all services. Plugins specific to IMAP,
18633 LDA, etc.@: are added to this list in their own .conf files.
18634 Defaults to @samp{()}.
18637 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
18638 The minimum number of mails in a mailbox before updates are done to
18639 cache file. This allows optimizing Dovecot's behavior to do less disk
18640 writes at the cost of more disk reads.
18641 Defaults to @samp{0}.
18644 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
18645 When IDLE command is running, mailbox is checked once in a while to
18646 see if there are any new mails or other changes. This setting defines
18647 the minimum time to wait between those checks. Dovecot can also use
18648 dnotify, inotify and kqueue to find out immediately when changes
18650 Defaults to @samp{"30 secs"}.
18653 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
18654 Save mails with CR+LF instead of plain LF. This makes sending those
18655 mails take less CPU, especially with sendfile() syscall with Linux and
18656 FreeBSD. But it also creates a bit more disk I/O which may just make it
18657 slower. Also note that if other software reads the mboxes/maildirs,
18658 they may handle the extra CRs wrong and cause problems.
18659 Defaults to @samp{#f}.
18662 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
18663 By default LIST command returns all entries in maildir beginning
18664 with a dot. Enabling this option makes Dovecot return only entries
18665 which are directories. This is done by stat()ing each entry, so it
18666 causes more disk I/O.
18667 (For systems setting struct @samp{dirent->d_type} this check is free
18668 and it's done always regardless of this setting).
18669 Defaults to @samp{#f}.
18672 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
18673 When copying a message, do it with hard links whenever possible.
18674 This makes the performance much better, and it's unlikely to have any
18676 Defaults to @samp{#t}.
18679 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
18680 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
18681 directory only when its mtime changes unexpectedly or when we can't find
18682 the mail otherwise.
18683 Defaults to @samp{#f}.
18686 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
18687 Which locking methods to use for locking mbox. There are four
18692 Create <mailbox>.lock file. This is the oldest and most NFS-safe
18693 solution. If you want to use /var/mail/ like directory, the users will
18694 need write access to that directory.
18696 Same as dotlock, but if it fails because of permissions or because there
18697 isn't enough disk space, just skip it.
18699 Use this if possible. Works with NFS too if lockd is used.
18701 May not exist in all systems. Doesn't work with NFS.
18703 May not exist in all systems. Doesn't work with NFS.
18706 You can use multiple locking methods; if you do the order they're declared
18707 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
18708 locking methods as well. Some operating systems don't allow using some of
18709 them simultaneously.
18712 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
18716 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
18717 Maximum time to wait for lock (all of them) before aborting.
18718 Defaults to @samp{"5 mins"}.
18721 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
18722 If dotlock exists but the mailbox isn't modified in any way,
18723 override the lock file after this much time.
18724 Defaults to @samp{"2 mins"}.
18727 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
18728 When mbox changes unexpectedly we have to fully read it to find out
18729 what changed. If the mbox is large this can take a long time. Since
18730 the change is usually just a newly appended mail, it'd be faster to
18731 simply read the new mails. If this setting is enabled, Dovecot does
18732 this but still safely fallbacks to re-reading the whole mbox file
18733 whenever something in mbox isn't how it's expected to be. The only real
18734 downside to this setting is that if some other MUA changes message
18735 flags, Dovecot doesn't notice it immediately. Note that a full sync is
18736 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
18737 Defaults to @samp{#t}.
18740 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
18741 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
18742 EXAMINE, EXPUNGE or CHECK commands. If this is set,
18743 @samp{mbox-dirty-syncs} is ignored.
18744 Defaults to @samp{#f}.
18747 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
18748 Delay writing mbox headers until doing a full write sync (EXPUNGE
18749 and CHECK commands and when closing the mailbox). This is especially
18750 useful for POP3 where clients often delete all mails. The downside is
18751 that our changes aren't immediately visible to other MUAs.
18752 Defaults to @samp{#t}.
18755 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
18756 If mbox size is smaller than this (e.g.@: 100k), don't write index
18757 files. If an index file already exists it's still read, just not
18759 Defaults to @samp{0}.
18762 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
18763 Maximum dbox file size until it's rotated.
18764 Defaults to @samp{10000000}.
18767 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
18768 Maximum dbox file age until it's rotated. Typically in days. Day
18769 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
18771 Defaults to @samp{"1d"}.
18774 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
18775 When creating new mdbox files, immediately preallocate their size to
18776 @samp{mdbox-rotate-size}. This setting currently works only in Linux
18777 with some file systems (ext4, xfs).
18778 Defaults to @samp{#f}.
18781 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
18782 sdbox and mdbox support saving mail attachments to external files,
18783 which also allows single instance storage for them. Other backends
18784 don't support this for now.
18786 WARNING: This feature hasn't been tested much yet. Use at your own risk.
18788 Directory root where to store mail attachments. Disabled, if empty.
18789 Defaults to @samp{""}.
18792 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
18793 Attachments smaller than this aren't saved externally. It's also
18794 possible to write a plugin to disable saving specific attachments
18796 Defaults to @samp{128000}.
18799 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
18800 File system backend to use for saving attachments:
18803 No SiS done by Dovecot (but this might help FS's own deduplication)
18805 SiS with immediate byte-by-byte comparison during saving
18806 @item sis-queue posix
18807 SiS with delayed comparison and deduplication.
18809 Defaults to @samp{"sis posix"}.
18812 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
18813 Hash format to use in attachment filenames. You can add any text and
18814 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
18815 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
18816 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
18817 Defaults to @samp{"%@{sha1@}"}.
18820 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
18822 Defaults to @samp{100}.
18825 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
18827 Defaults to @samp{1000}.
18830 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
18831 Default VSZ (virtual memory size) limit for service processes.
18832 This is mainly intended to catch and kill processes that leak memory
18833 before they eat up everything.
18834 Defaults to @samp{256000000}.
18837 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
18838 Login user is internally used by login processes. This is the most
18839 untrusted user in Dovecot system. It shouldn't have access to anything
18841 Defaults to @samp{"dovenull"}.
18844 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
18845 Internal user is used by unprivileged processes. It should be
18846 separate from login user, so that login processes can't disturb other
18848 Defaults to @samp{"dovecot"}.
18851 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
18852 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
18853 Defaults to @samp{"required"}.
18856 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
18857 PEM encoded X.509 SSL/TLS certificate (public key).
18858 Defaults to @samp{"</etc/dovecot/default.pem"}.
18861 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
18862 PEM encoded SSL/TLS private key. The key is opened before
18863 dropping root privileges, so keep the key file unreadable by anyone but
18865 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
18868 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
18869 If key file is password protected, give the password here.
18870 Alternatively give it when starting dovecot with -p parameter. Since
18871 this file is often world-readable, you may want to place this setting
18872 instead to a different.
18873 Defaults to @samp{""}.
18876 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
18877 PEM encoded trusted certificate authority. Set this only if you
18878 intend to use @samp{ssl-verify-client-cert? #t}. The file should
18879 contain the CA certificate(s) followed by the matching
18880 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
18881 Defaults to @samp{""}.
18884 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
18885 Require that CRL check succeeds for client certificates.
18886 Defaults to @samp{#t}.
18889 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
18890 Request client to send a certificate. If you also want to require
18891 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
18892 Defaults to @samp{#f}.
18895 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
18896 Which field from certificate to use for username. commonName and
18897 x500UniqueIdentifier are the usual choices. You'll also need to set
18898 @samp{auth-ssl-username-from-cert? #t}.
18899 Defaults to @samp{"commonName"}.
18902 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
18903 Minimum SSL protocol version to accept.
18904 Defaults to @samp{"TLSv1"}.
18907 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
18908 SSL ciphers to use.
18909 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
18912 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
18913 SSL crypto device to use, for valid values run "openssl engine".
18914 Defaults to @samp{""}.
18917 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
18918 Address to use when sending rejection mails.
18919 %d expands to recipient domain.
18920 Defaults to @samp{"postmaster@@%d"}.
18923 @deftypevr {@code{dovecot-configuration} parameter} string hostname
18924 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
18925 and in LMTP replies. Default is the system's real hostname@@domain.
18926 Defaults to @samp{""}.
18929 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
18930 If user is over quota, return with temporary failure instead of
18932 Defaults to @samp{#f}.
18935 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
18936 Binary to use for sending mails.
18937 Defaults to @samp{"/usr/sbin/sendmail"}.
18940 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
18941 If non-empty, send mails via this SMTP host[:port] instead of
18943 Defaults to @samp{""}.
18946 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
18947 Subject: header to use for rejection mails. You can use the same
18948 variables as for @samp{rejection-reason} below.
18949 Defaults to @samp{"Rejected: %s"}.
18952 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
18953 Human readable error message for rejection mails. You can use
18966 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
18969 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
18970 Delimiter character between local-part and detail in email
18972 Defaults to @samp{"+"}.
18975 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
18976 Header where the original recipient address (SMTP's RCPT TO:
18977 address) is taken from if not available elsewhere. With dovecot-lda -a
18978 parameter overrides this. A commonly used header for this is
18980 Defaults to @samp{""}.
18983 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
18984 Should saving a mail to a nonexistent mailbox automatically create
18986 Defaults to @samp{#f}.
18989 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
18990 Should automatically created mailboxes be also automatically
18992 Defaults to @samp{#f}.
18995 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
18996 Maximum IMAP command line length. Some clients generate very long
18997 command lines with huge mailboxes, so you may need to raise this if you
18998 get "Too long argument" or "IMAP command line too large" errors
19000 Defaults to @samp{64000}.
19003 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
19004 IMAP logout format string:
19007 total number of bytes read from client
19009 total number of bytes sent to client.
19011 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
19012 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@}"}.
19015 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
19016 Override the IMAP CAPABILITY response. If the value begins with '+',
19017 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
19018 Defaults to @samp{""}.
19021 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
19022 How long to wait between "OK Still here" notifications when client
19024 Defaults to @samp{"2 mins"}.
19027 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
19028 ID field names and values to send to clients. Using * as the value
19029 makes Dovecot use the default value. The following fields have default
19030 values currently: name, version, os, os-version, support-url,
19032 Defaults to @samp{""}.
19035 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
19036 ID fields sent by client to log. * means everything.
19037 Defaults to @samp{""}.
19040 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
19041 Workarounds for various client bugs:
19044 @item delay-newmail
19045 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
19046 CHECK commands. Some clients ignore them otherwise, for example OSX
19047 Mail (<v2.1). Outlook Express breaks more badly though, without this it
19048 may show user "Message no longer in server" errors. Note that OE6
19049 still breaks even with this workaround if synchronization is set to
19052 @item tb-extra-mailbox-sep
19053 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
19054 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
19055 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
19057 @item tb-lsub-flags
19058 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
19059 This makes Thunderbird realize they aren't selectable and show them
19060 greyed out, instead of only later giving "not selectable" popup error.
19062 Defaults to @samp{()}.
19065 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
19066 Host allowed in URLAUTH URLs sent by client. "*" allows all.
19067 Defaults to @samp{""}.
19071 Whew! Lots of configuration options. The nice thing about it though is
19072 that Guix has a complete interface to Dovecot's configuration
19073 language. This allows not only a nice way to declare configurations,
19074 but also offers reflective capabilities as well: users can write code to
19075 inspect and transform configurations from within Scheme.
19077 However, it could be that you just want to get a @code{dovecot.conf} up
19078 and running. In that case, you can pass an
19079 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
19080 @code{dovecot-service}. As its name indicates, an opaque configuration
19081 does not have easy reflective capabilities.
19083 Available @code{opaque-dovecot-configuration} fields are:
19085 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
19086 The dovecot package.
19089 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
19090 The contents of the @code{dovecot.conf}, as a string.
19093 For example, if your @code{dovecot.conf} is just the empty string, you
19094 could instantiate a dovecot service like this:
19097 (dovecot-service #:config
19098 (opaque-dovecot-configuration
19102 @subsubheading OpenSMTPD Service
19104 @deffn {Scheme Variable} opensmtpd-service-type
19105 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
19106 service, whose value should be an @code{opensmtpd-configuration} object
19107 as in this example:
19110 (service opensmtpd-service-type
19111 (opensmtpd-configuration
19112 (config-file (local-file "./my-smtpd.conf"))))
19116 @deftp {Data Type} opensmtpd-configuration
19117 Data type representing the configuration of opensmtpd.
19120 @item @code{package} (default: @var{opensmtpd})
19121 Package object of the OpenSMTPD SMTP server.
19123 @item @code{config-file} (default: @code{%default-opensmtpd-file})
19124 File-like object of the OpenSMTPD configuration file to use. By default
19125 it listens on the loopback network interface, and allows for mail from
19126 users and daemons on the local machine, as well as permitting email to
19127 remote servers. Run @command{man smtpd.conf} for more information.
19132 @subsubheading Exim Service
19134 @cindex mail transfer agent (MTA)
19135 @cindex MTA (mail transfer agent)
19138 @deffn {Scheme Variable} exim-service-type
19139 This is the type of the @uref{https://exim.org, Exim} mail transfer
19140 agent (MTA), whose value should be an @code{exim-configuration} object
19141 as in this example:
19144 (service exim-service-type
19145 (exim-configuration
19146 (config-file (local-file "./my-exim.conf"))))
19150 In order to use an @code{exim-service-type} service you must also have a
19151 @code{mail-aliases-service-type} service present in your
19152 @code{operating-system} (even if it has no aliases).
19154 @deftp {Data Type} exim-configuration
19155 Data type representing the configuration of exim.
19158 @item @code{package} (default: @var{exim})
19159 Package object of the Exim server.
19161 @item @code{config-file} (default: @code{#f})
19162 File-like object of the Exim configuration file to use. If its value is
19163 @code{#f} then use the default configuration file from the package
19164 provided in @code{package}. The resulting configuration file is loaded
19165 after setting the @code{exim_user} and @code{exim_group} configuration
19171 @subsubheading Getmail service
19176 @deffn {Scheme Variable} getmail-service-type
19177 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
19178 mail retriever, whose value should be an @code{getmail-configuration}.
19181 Available @code{getmail-configuration} fields are:
19183 @deftypevr {@code{getmail-configuration} parameter} symbol name
19184 A symbol to identify the getmail service.
19186 Defaults to @samp{"unset"}.
19190 @deftypevr {@code{getmail-configuration} parameter} package package
19191 The getmail package to use.
19195 @deftypevr {@code{getmail-configuration} parameter} string user
19196 The user to run getmail as.
19198 Defaults to @samp{"getmail"}.
19202 @deftypevr {@code{getmail-configuration} parameter} string group
19203 The group to run getmail as.
19205 Defaults to @samp{"getmail"}.
19209 @deftypevr {@code{getmail-configuration} parameter} string directory
19210 The getmail directory to use.
19212 Defaults to @samp{"/var/lib/getmail/default"}.
19216 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
19217 The getmail configuration file to use.
19219 Available @code{getmail-configuration-file} fields are:
19221 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
19222 What mail account to retrieve mail from, and how to access that account.
19224 Available @code{getmail-retriever-configuration} fields are:
19226 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
19227 The type of mail retriever to use. Valid values include @samp{passwd}
19230 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
19234 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
19235 Username to login to the mail server with.
19237 Defaults to @samp{unset}.
19241 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
19242 Username to login to the mail server with.
19244 Defaults to @samp{unset}.
19248 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
19249 Port number to connect to.
19251 Defaults to @samp{#f}.
19255 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
19256 Override fields from passwd.
19258 Defaults to @samp{""}.
19262 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
19263 Override fields from passwd.
19265 Defaults to @samp{()}.
19269 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
19270 PEM-formatted key file to use for the TLS negotiation.
19272 Defaults to @samp{""}.
19276 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
19277 PEM-formatted certificate file to use for the TLS negotiation.
19279 Defaults to @samp{""}.
19283 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
19284 CA certificates to use.
19286 Defaults to @samp{""}.
19290 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
19291 Extra retriever parameters.
19293 Defaults to @samp{()}.
19299 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
19300 What to do with retrieved messages.
19302 Available @code{getmail-destination-configuration} fields are:
19304 @deftypevr {@code{getmail-destination-configuration} parameter} string type
19305 The type of mail destination. Valid values include @samp{Maildir},
19306 @samp{Mboxrd} and @samp{MDA_external}.
19308 Defaults to @samp{unset}.
19312 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
19313 The path option for the mail destination. The behaviour depends on the
19316 Defaults to @samp{""}.
19320 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
19321 Extra destination parameters
19323 Defaults to @samp{()}.
19329 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
19332 Available @code{getmail-options-configuration} fields are:
19334 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
19335 If set to @samp{0}, getmail will only print warnings and errors. A
19336 value of @samp{1} means that messages will be printed about retrieving
19337 and deleting messages. If set to @samp{2}, getmail will print messages
19338 about each of it's actions.
19340 Defaults to @samp{1}.
19344 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
19345 If true, getmail will retrieve all available messages. Otherwise it
19346 will only retrieve messages it hasn't seen previously.
19348 Defaults to @samp{#t}.
19352 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
19353 If set to true, messages will be deleted from the server after
19354 retrieving and successfully delivering them. Otherwise, messages will
19355 be left on the server.
19357 Defaults to @samp{#f}.
19361 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
19362 Getmail will delete messages this number of days after seeing them, if
19363 they have been delivered. This means messages will be left on the
19364 server this number of days after delivering them. A value of @samp{0}
19365 disabled this feature.
19367 Defaults to @samp{0}.
19371 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
19372 Delete messages larger than this of bytes after retrieving them, even if
19373 the delete and delete-after options are disabled. A value of @samp{0}
19374 disables this feature.
19376 Defaults to @samp{0}.
19380 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
19381 Retrieve messages totalling up to this number of bytes before closing
19382 the session with the server. A value of @samp{0} disables this feature.
19384 Defaults to @samp{0}.
19388 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
19389 Don't retrieve messages larger than this number of bytes. A value of
19390 @samp{0} disables this feature.
19392 Defaults to @samp{0}.
19396 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
19397 If true, getmail will add a Delivered-To header to messages.
19399 Defaults to @samp{#t}.
19403 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
19404 If set, getmail adds a Received header to the messages.
19406 Defaults to @samp{#t}.
19410 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
19411 Getmail will record a log of its actions to the named file. A value of
19412 @samp{""} disables this feature.
19414 Defaults to @samp{""}.
19418 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
19419 If true, getmail will record a log of its actions using the system
19422 Defaults to @samp{#f}.
19426 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
19427 If true, getmail will log information about messages not retrieved and
19428 the reason for not retrieving them, as well as starting and ending
19431 Defaults to @samp{#f}.
19435 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
19436 Extra options to include.
19438 Defaults to @samp{()}.
19446 @deftypevr {@code{getmail-configuration} parameter} list idle
19447 A list of mailboxes that getmail should wait on the server for new mail
19448 notifications. This depends on the server supporting the IDLE
19451 Defaults to @samp{()}.
19455 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
19456 Environment variables to set for getmail.
19458 Defaults to @samp{()}.
19462 @subsubheading Mail Aliases Service
19464 @cindex email aliases
19465 @cindex aliases, for email addresses
19467 @deffn {Scheme Variable} mail-aliases-service-type
19468 This is the type of the service which provides @code{/etc/aliases},
19469 specifying how to deliver mail to users on this system.
19472 (service mail-aliases-service-type
19473 '(("postmaster" "bob")
19474 ("bob" "bob@@example.com" "bob@@example2.com")))
19478 The configuration for a @code{mail-aliases-service-type} service is an
19479 association list denoting how to deliver mail that comes to this
19480 system. Each entry is of the form @code{(alias addresses ...)}, with
19481 @code{alias} specifying the local alias and @code{addresses} specifying
19482 where to deliver this user's mail.
19484 The aliases aren't required to exist as users on the local system. In
19485 the above example, there doesn't need to be a @code{postmaster} entry in
19486 the @code{operating-system}'s @code{user-accounts} in order to deliver
19487 the @code{postmaster} mail to @code{bob} (which subsequently would
19488 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
19490 @subsubheading GNU Mailutils IMAP4 Daemon
19491 @cindex GNU Mailutils IMAP4 Daemon
19493 @deffn {Scheme Variable} imap4d-service-type
19494 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
19495 mailutils, GNU Mailutils Manual}), whose value should be an
19496 @code{imap4d-configuration} object as in this example:
19499 (service imap4d-service-type
19500 (imap4d-configuration
19501 (config-file (local-file "imap4d.conf"))))
19505 @deftp {Data Type} imap4d-configuration
19506 Data type representing the configuration of @command{imap4d}.
19509 @item @code{package} (default: @code{mailutils})
19510 The package that provides @command{imap4d}.
19512 @item @code{config-file} (default: @code{%default-imap4d-config-file})
19513 File-like object of the configuration file to use, by default it will listen
19514 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
19515 Mailutils Manual}, for details.
19520 @node Messaging Services
19521 @subsection Messaging Services
19526 The @code{(gnu services messaging)} module provides Guix service
19527 definitions for messaging services: currently only Prosody is supported.
19529 @subsubheading Prosody Service
19531 @deffn {Scheme Variable} prosody-service-type
19532 This is the type for the @uref{https://prosody.im, Prosody XMPP
19533 communication server}. Its value must be a @code{prosody-configuration}
19534 record as in this example:
19537 (service prosody-service-type
19538 (prosody-configuration
19539 (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
19542 (int-component-configuration
19543 (hostname "conference.example.net")
19545 (mod-muc (mod-muc-configuration)))))
19548 (virtualhost-configuration
19549 (domain "example.net"))))))
19552 See below for details about @code{prosody-configuration}.
19556 By default, Prosody does not need much configuration. Only one
19557 @code{virtualhosts} field is needed: it specifies the domain you wish
19560 You can perform various sanity checks on the generated configuration
19561 with the @code{prosodyctl check} command.
19563 Prosodyctl will also help you to import certificates from the
19564 @code{letsencrypt} directory so that the @code{prosody} user can access
19565 them. See @url{https://prosody.im/doc/letsencrypt}.
19568 prosodyctl --root cert import /etc/letsencrypt/live
19571 The available configuration parameters follow. Each parameter
19572 definition is preceded by its type; for example, @samp{string-list foo}
19573 indicates that the @code{foo} parameter should be specified as a list of
19574 strings. Types starting with @code{maybe-} denote parameters that won't
19575 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
19577 There is also a way to specify the configuration as a string, if you
19578 have an old @code{prosody.cfg.lua} file that you want to port over from
19579 some other system; see the end for more details.
19581 The @code{file-object} type designates either a file-like object
19582 (@pxref{G-Expressions, file-like objects}) or a file name.
19584 @c The following documentation was initially generated by
19585 @c (generate-documentation) in (gnu services messaging). Manually maintained
19586 @c documentation is better, so we shouldn't hesitate to edit below as
19587 @c needed. However if the change you want to make to this documentation
19588 @c can be done in an automated way, it's probably easier to change
19589 @c (generate-documentation) than to make it below and have to deal with
19590 @c the churn as Prosody updates.
19592 Available @code{prosody-configuration} fields are:
19594 @deftypevr {@code{prosody-configuration} parameter} package prosody
19595 The Prosody package.
19598 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
19599 Location of the Prosody data storage directory. See
19600 @url{https://prosody.im/doc/configure}.
19601 Defaults to @samp{"/var/lib/prosody"}.
19604 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
19605 Additional plugin directories. They are searched in all the specified
19606 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
19607 Defaults to @samp{()}.
19610 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
19611 Every virtual host and component needs a certificate so that clients and
19612 servers can securely verify its identity. Prosody will automatically load
19613 certificates/keys from the directory specified here.
19614 Defaults to @samp{"/etc/prosody/certs"}.
19617 @deftypevr {@code{prosody-configuration} parameter} string-list admins
19618 This is a list of accounts that are admins for the server. Note that you
19619 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
19620 @url{https://prosody.im/doc/creating_accounts}.
19621 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
19622 Defaults to @samp{()}.
19625 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
19626 Enable use of libevent for better performance under high load. See
19627 @url{https://prosody.im/doc/libevent}.
19628 Defaults to @samp{#f}.
19631 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
19632 This is the list of modules Prosody will load on startup. It looks for
19633 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
19634 Documentation on modules can be found at:
19635 @url{https://prosody.im/doc/modules}.
19636 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
19639 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
19640 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
19641 should you want to disable them then add them to this list.
19642 Defaults to @samp{()}.
19645 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
19646 Path to a text file where the shared groups are defined. If this path is
19647 empty then @samp{mod_groups} does nothing. See
19648 @url{https://prosody.im/doc/modules/mod_groups}.
19649 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
19652 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
19653 Disable account creation by default, for security. See
19654 @url{https://prosody.im/doc/creating_accounts}.
19655 Defaults to @samp{#f}.
19658 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
19659 These are the SSL/TLS-related settings. Most of them are disabled so to
19660 use Prosody's defaults. If you do not completely understand these options, do
19661 not add them to your config, it is easy to lower the security of your server
19662 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
19664 Available @code{ssl-configuration} fields are:
19666 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
19667 This determines what handshake to use.
19670 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
19671 Path to your private key file.
19674 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
19675 Path to your certificate file.
19678 @deftypevr {@code{ssl-configuration} parameter} file-object capath
19679 Path to directory containing root certificates that you wish Prosody to
19680 trust when verifying the certificates of remote servers.
19681 Defaults to @samp{"/etc/ssl/certs"}.
19684 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
19685 Path to a file containing root certificates that you wish Prosody to trust.
19686 Similar to @code{capath} but with all certificates concatenated together.
19689 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
19690 A list of verification options (these mostly map to OpenSSL's
19691 @code{set_verify()} flags).
19694 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
19695 A list of general options relating to SSL/TLS. These map to OpenSSL's
19696 @code{set_options()}. For a full list of options available in LuaSec, see the
19700 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
19701 How long a chain of certificate authorities to check when looking for a
19702 trusted root certificate.
19705 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
19706 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
19707 clients, and in what order.
19710 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
19711 A path to a file containing parameters for Diffie-Hellman key exchange. You
19712 can create such a file with:
19713 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
19716 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
19717 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
19718 @samp{"secp384r1"}.
19721 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
19722 A list of ``extra'' verification options.
19725 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
19726 Password for encrypted private keys.
19731 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
19732 Whether to force all client-to-server connections to be encrypted or not.
19733 See @url{https://prosody.im/doc/modules/mod_tls}.
19734 Defaults to @samp{#f}.
19737 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
19738 Set of mechanisms that will never be offered. See
19739 @url{https://prosody.im/doc/modules/mod_saslauth}.
19740 Defaults to @samp{("DIGEST-MD5")}.
19743 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
19744 Whether to force all server-to-server connections to be encrypted or not.
19745 See @url{https://prosody.im/doc/modules/mod_tls}.
19746 Defaults to @samp{#f}.
19749 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
19750 Whether to require encryption and certificate authentication. This
19751 provides ideal security, but requires servers you communicate with to support
19752 encryption AND present valid, trusted certificates. See
19753 @url{https://prosody.im/doc/s2s#security}.
19754 Defaults to @samp{#f}.
19757 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
19758 Many servers don't support encryption or have invalid or self-signed
19759 certificates. You can list domains here that will not be required to
19760 authenticate using certificates. They will be authenticated using DNS. See
19761 @url{https://prosody.im/doc/s2s#security}.
19762 Defaults to @samp{()}.
19765 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
19766 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
19767 valid certificates for some domains by specifying a list here. See
19768 @url{https://prosody.im/doc/s2s#security}.
19769 Defaults to @samp{()}.
19772 @deftypevr {@code{prosody-configuration} parameter} string authentication
19773 Select the authentication backend to use. The default provider stores
19774 passwords in plaintext and uses Prosody's configured data storage to store the
19775 authentication data. If you do not trust your server please see
19776 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
19777 about using the hashed backend. See also
19778 @url{https://prosody.im/doc/authentication}
19779 Defaults to @samp{"internal_plain"}.
19782 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
19783 Set logging options. Advanced logging configuration is not yet supported
19784 by the Prosody service. See @url{https://prosody.im/doc/logging}.
19785 Defaults to @samp{"*syslog"}.
19788 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
19789 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
19790 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
19793 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
19794 Maximum allowed size of the HTTP body (in bytes).
19797 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
19798 Some modules expose their own URL in various ways. This URL is built
19799 from the protocol, host and port used. If Prosody sits behind a proxy, the
19800 public URL will be @code{http-external-url} instead. See
19801 @url{https://prosody.im/doc/http#external_url}.
19804 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
19805 A host in Prosody is a domain on which user accounts can be created. For
19806 example if you want your users to have addresses like
19807 @samp{"john.smith@@example.com"} then you need to add a host
19808 @samp{"example.com"}. All options in this list will apply only to this host.
19810 Note: the name @emph{virtual} host is used in configuration to avoid confusion with
19811 the actual physical host that Prosody is installed on. A single Prosody
19812 instance can serve many domains, each one defined as a VirtualHost entry in
19813 Prosody's configuration. Conversely a server that hosts a single domain would
19814 have just one VirtualHost entry.
19816 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
19818 Available @code{virtualhost-configuration} fields are:
19820 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:
19821 @deftypevr {@code{virtualhost-configuration} parameter} string domain
19822 Domain you wish Prosody to serve.
19827 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
19828 Components are extra services on a server which are available to clients,
19829 usually on a subdomain of the main server (such as
19830 @samp{"mycomponent.example.com"}). Example components might be chatroom
19831 servers, user directories, or gateways to other protocols.
19833 Internal components are implemented with Prosody-specific plugins. To add an
19834 internal component, you simply fill the hostname field, and the plugin you wish
19835 to use for the component.
19837 See @url{https://prosody.im/doc/components}.
19838 Defaults to @samp{()}.
19840 Available @code{int-component-configuration} fields are:
19842 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:
19843 @deftypevr {@code{int-component-configuration} parameter} string hostname
19844 Hostname of the component.
19847 @deftypevr {@code{int-component-configuration} parameter} string plugin
19848 Plugin you wish to use for the component.
19851 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
19852 Multi-user chat (MUC) is Prosody's module for allowing you to create
19853 hosted chatrooms/conferences for XMPP users.
19855 General information on setting up and using multi-user chatrooms can be found
19856 in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
19857 which you should read if you are new to XMPP chatrooms.
19859 See also @url{https://prosody.im/doc/modules/mod_muc}.
19861 Available @code{mod-muc-configuration} fields are:
19863 @deftypevr {@code{mod-muc-configuration} parameter} string name
19864 The name to return in service discovery responses.
19865 Defaults to @samp{"Prosody Chatrooms"}.
19868 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
19869 If @samp{#t}, this will only allow admins to create new chatrooms.
19870 Otherwise anyone can create a room. The value @samp{"local"} restricts room
19871 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
19872 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
19873 restricts to service administrators only.
19874 Defaults to @samp{#f}.
19877 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
19878 Maximum number of history messages that will be sent to the member that has
19879 just joined the room.
19880 Defaults to @samp{20}.
19887 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
19888 External components use XEP-0114, which most standalone components
19889 support. To add an external component, you simply fill the hostname field. See
19890 @url{https://prosody.im/doc/components}.
19891 Defaults to @samp{()}.
19893 Available @code{ext-component-configuration} fields are:
19895 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:
19896 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
19897 Password which the component will use to log in.
19900 @deftypevr {@code{ext-component-configuration} parameter} string hostname
19901 Hostname of the component.
19906 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
19907 Port(s) Prosody listens on for component connections.
19908 Defaults to @samp{(5347)}.
19911 @deftypevr {@code{prosody-configuration} parameter} string component-interface
19912 Interface Prosody listens on for component connections.
19913 Defaults to @samp{"127.0.0.1"}.
19916 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
19917 Raw content that will be added to the configuration file.
19920 It could be that you just want to get a @code{prosody.cfg.lua}
19921 up and running. In that case, you can pass an
19922 @code{opaque-prosody-configuration} record as the value of
19923 @code{prosody-service-type}. As its name indicates, an opaque configuration
19924 does not have easy reflective capabilities.
19925 Available @code{opaque-prosody-configuration} fields are:
19927 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
19928 The prosody package.
19931 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
19932 The contents of the @code{prosody.cfg.lua} to use.
19935 For example, if your @code{prosody.cfg.lua} is just the empty
19936 string, you could instantiate a prosody service like this:
19939 (service prosody-service-type
19940 (opaque-prosody-configuration
19941 (prosody.cfg.lua "")))
19944 @c end of Prosody auto-generated documentation
19946 @subsubheading BitlBee Service
19948 @cindex IRC (Internet Relay Chat)
19949 @cindex IRC gateway
19950 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
19951 interface to a variety of messaging protocols such as XMPP.
19953 @defvr {Scheme Variable} bitlbee-service-type
19954 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
19955 gateway daemon. Its value is a @code{bitlbee-configuration} (see
19958 To have BitlBee listen on port 6667 on localhost, add this line to your
19962 (service bitlbee-service-type)
19966 @deftp {Data Type} bitlbee-configuration
19967 This is the configuration for BitlBee, with the following fields:
19970 @item @code{interface} (default: @code{"127.0.0.1"})
19971 @itemx @code{port} (default: @code{6667})
19972 Listen on the network interface corresponding to the IP address
19973 specified in @var{interface}, on @var{port}.
19975 When @var{interface} is @code{127.0.0.1}, only local clients can
19976 connect; when it is @code{0.0.0.0}, connections can come from any
19977 networking interface.
19979 @item @code{bitlbee} (default: @code{bitlbee})
19980 The BitlBee package to use.
19982 @item @code{plugins} (default: @code{'()})
19983 List of plugin packages to use---e.g., @code{bitlbee-discord}.
19985 @item @code{extra-settings} (default: @code{""})
19986 Configuration snippet added as-is to the BitlBee configuration file.
19990 @subsubheading Quassel Service
19992 @cindex IRC (Internet Relay Chat)
19993 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
19994 meaning that one or more clients can attach to and detach from the
19997 @defvr {Scheme Variable} quassel-service-type
19998 This is the service type for the @url{https://quassel-irc.org/,Quassel}
19999 IRC backend daemon. Its value is a @code{quassel-configuration}
20003 @deftp {Data Type} quassel-configuration
20004 This is the configuration for Quassel, with the following fields:
20007 @item @code{quassel} (default: @code{quassel})
20008 The Quassel package to use.
20010 @item @code{interface} (default: @code{"::,0.0.0.0"})
20011 @item @code{port} (default: @code{4242})
20012 Listen on the network interface(s) corresponding to the IPv4 or IPv6
20013 interfaces specified in the comma delimited @var{interface}, on
20016 @item @code{loglevel} (default: @code{"Info"})
20017 The level of logging desired. Accepted values are Debug, Info, Warning
20022 @node Telephony Services
20023 @subsection Telephony Services
20025 @cindex Murmur (VoIP server)
20026 @cindex VoIP server
20027 This section describes how to set up and run a Murmur server. Murmur is
20028 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
20031 @deftp {Data Type} murmur-configuration
20032 The service type for the Murmur server. An example configuration can
20036 (service murmur-service-type
20037 (murmur-configuration
20039 "Welcome to this Mumble server running on Guix!")
20040 (cert-required? #t) ;disallow text password logins
20041 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
20042 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
20045 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
20046 password with the command that is printed during the activation phase.
20048 It is recommended to register a normal Mumble user account
20049 and grant it admin or moderator rights.
20050 You can use the @code{mumble} client to
20051 login as new normal user, register yourself, and log out.
20052 For the next step login with the name @code{SuperUser} use
20053 the @code{SuperUser} password that you set previously,
20054 and grant your newly registered mumble user administrator or moderator
20055 rights and create some channels.
20057 Available @code{murmur-configuration} fields are:
20060 @item @code{package} (default: @code{mumble})
20061 Package that contains @code{bin/murmurd}.
20063 @item @code{user} (default: @code{"murmur"})
20064 User who will run the Murmur server.
20066 @item @code{group} (default: @code{"murmur"})
20067 Group of the user who will run the murmur server.
20069 @item @code{port} (default: @code{64738})
20070 Port on which the server will listen.
20072 @item @code{welcome-text} (default: @code{""})
20073 Welcome text sent to clients when they connect.
20075 @item @code{server-password} (default: @code{""})
20076 Password the clients have to enter in order to connect.
20078 @item @code{max-users} (default: @code{100})
20079 Maximum of users that can be connected to the server at once.
20081 @item @code{max-user-bandwidth} (default: @code{#f})
20082 Maximum voice traffic a user can send per second.
20084 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
20085 File name of the sqlite database.
20086 The service's user will become the owner of the directory.
20088 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
20089 File name of the log file.
20090 The service's user will become the owner of the directory.
20092 @item @code{autoban-attempts} (default: @code{10})
20093 Maximum number of logins a user can make in @code{autoban-timeframe}
20094 without getting auto banned for @code{autoban-time}.
20096 @item @code{autoban-timeframe} (default: @code{120})
20097 Timeframe for autoban in seconds.
20099 @item @code{autoban-time} (default: @code{300})
20100 Amount of time in seconds for which a client gets banned
20101 when violating the autoban limits.
20103 @item @code{opus-threshold} (default: @code{100})
20104 Percentage of clients that need to support opus
20105 before switching over to opus audio codec.
20107 @item @code{channel-nesting-limit} (default: @code{10})
20108 How deep channels can be nested at maximum.
20110 @item @code{channelname-regex} (default: @code{#f})
20111 A string in form of a Qt regular expression that channel names must conform to.
20113 @item @code{username-regex} (default: @code{#f})
20114 A string in form of a Qt regular expression that user names must conform to.
20116 @item @code{text-message-length} (default: @code{5000})
20117 Maximum size in bytes that a user can send in one text chat message.
20119 @item @code{image-message-length} (default: @code{(* 128 1024)})
20120 Maximum size in bytes that a user can send in one image message.
20122 @item @code{cert-required?} (default: @code{#f})
20123 If it is set to @code{#t} clients that use weak password authentication
20124 will not be accepted. Users must have completed the certificate wizard to join.
20126 @item @code{remember-channel?} (default: @code{#f})
20127 Should murmur remember the last channel each user was in when they disconnected
20128 and put them into the remembered channel when they rejoin.
20130 @item @code{allow-html?} (default: @code{#f})
20131 Should html be allowed in text messages, user comments, and channel descriptions.
20133 @item @code{allow-ping?} (default: @code{#f})
20134 Setting to true exposes the current user count, the maximum user count, and
20135 the server's maximum bandwidth per client to unauthenticated users. In the
20136 Mumble client, this information is shown in the Connect dialog.
20138 Disabling this setting will prevent public listing of the server.
20140 @item @code{bonjour?} (default: @code{#f})
20141 Should the server advertise itself in the local network through the bonjour protocol.
20143 @item @code{send-version?} (default: @code{#f})
20144 Should the murmur server version be exposed in ping requests.
20146 @item @code{log-days} (default: @code{31})
20147 Murmur also stores logs in the database, which are accessible via RPC.
20148 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
20149 or -1 to disable logging to the database.
20151 @item @code{obfuscate-ips?} (default: @code{#t})
20152 Should logged ips be obfuscated to protect the privacy of users.
20154 @item @code{ssl-cert} (default: @code{#f})
20155 File name of the SSL/TLS certificate used for encrypted connections.
20158 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
20160 @item @code{ssl-key} (default: @code{#f})
20161 Filepath to the ssl private key used for encrypted connections.
20163 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
20166 @item @code{ssl-dh-params} (default: @code{#f})
20167 File name of a PEM-encoded file with Diffie-Hellman parameters
20168 for the SSL/TLS encryption. Alternatively you set it to
20169 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
20170 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
20172 @item @code{ssl-ciphers} (default: @code{#f})
20173 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
20176 This option is specified using
20177 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
20178 OpenSSL cipher list notation}.
20180 It is recommended that you try your cipher string using 'openssl ciphers <string>'
20181 before setting it here, to get a feel for which cipher suites you will get.
20182 After setting this option, it is recommend that you inspect your Murmur log
20183 to ensure that Murmur is using the cipher suites that you expected it to.
20185 Note: Changing this option may impact the backwards compatibility of your
20186 Murmur server, and can remove the ability for older Mumble clients to be able
20189 @item @code{public-registration} (default: @code{#f})
20190 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
20192 You can optionally register your server in the public server list that the
20193 @code{mumble} client shows on startup.
20194 You cannot register your server if you have set a @code{server-password},
20195 or set @code{allow-ping} to @code{#f}.
20197 It might take a few hours until it shows up in the public list.
20199 @item @code{file} (default: @code{#f})
20200 Optional alternative override for this configuration.
20204 @deftp {Data Type} murmur-public-registration-configuration
20205 Configuration for public registration of a murmur service.
20209 This is a display name for your server. Not to be confused with the hostname.
20211 @item @code{password}
20212 A password to identify your registration.
20213 Subsequent updates will need the same password. Don't lose your password.
20216 This should be a @code{http://} or @code{https://} link to your web
20219 @item @code{hostname} (default: @code{#f})
20220 By default your server will be listed by its IP address.
20221 If it is set your server will be linked by this host name instead.
20227 @node Monitoring Services
20228 @subsection Monitoring Services
20230 @subsubheading Tailon Service
20232 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
20233 viewing and searching log files.
20235 The following example will configure the service with default values.
20236 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
20239 (service tailon-service-type)
20242 The following example customises more of the Tailon configuration,
20243 adding @command{sed} to the list of allowed commands.
20246 (service tailon-service-type
20247 (tailon-configuration
20249 (tailon-configuration-file
20250 (allowed-commands '("tail" "grep" "awk" "sed"))))))
20254 @deftp {Data Type} tailon-configuration
20255 Data type representing the configuration of Tailon.
20256 This type has the following parameters:
20259 @item @code{config-file} (default: @code{(tailon-configuration-file)})
20260 The configuration file to use for Tailon. This can be set to a
20261 @dfn{tailon-configuration-file} record value, or any gexp
20262 (@pxref{G-Expressions}).
20264 For example, to instead use a local file, the @code{local-file} function
20268 (service tailon-service-type
20269 (tailon-configuration
20270 (config-file (local-file "./my-tailon.conf"))))
20273 @item @code{package} (default: @code{tailon})
20274 The tailon package to use.
20279 @deftp {Data Type} tailon-configuration-file
20280 Data type representing the configuration options for Tailon.
20281 This type has the following parameters:
20284 @item @code{files} (default: @code{(list "/var/log")})
20285 List of files to display. The list can include strings for a single file
20286 or directory, or a list, where the first item is the name of a
20287 subsection, and the remaining items are the files or directories in that
20290 @item @code{bind} (default: @code{"localhost:8080"})
20291 Address and port to which Tailon should bind on.
20293 @item @code{relative-root} (default: @code{#f})
20294 URL path to use for Tailon, set to @code{#f} to not use a path.
20296 @item @code{allow-transfers?} (default: @code{#t})
20297 Allow downloading the log files in the web interface.
20299 @item @code{follow-names?} (default: @code{#t})
20300 Allow tailing of not-yet existent files.
20302 @item @code{tail-lines} (default: @code{200})
20303 Number of lines to read initially from each file.
20305 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
20306 Commands to allow running. By default, @code{sed} is disabled.
20308 @item @code{debug?} (default: @code{#f})
20309 Set @code{debug?} to @code{#t} to show debug messages.
20311 @item @code{wrap-lines} (default: @code{#t})
20312 Initial line wrapping state in the web interface. Set to @code{#t} to
20313 initially wrap lines (the default), or to @code{#f} to initially not
20316 @item @code{http-auth} (default: @code{#f})
20317 HTTP authentication type to use. Set to @code{#f} to disable
20318 authentication (the default). Supported values are @code{"digest"} or
20321 @item @code{users} (default: @code{#f})
20322 If HTTP authentication is enabled (see @code{http-auth}), access will be
20323 restricted to the credentials provided here. To configure users, use a
20324 list of pairs, where the first element of the pair is the username, and
20325 the 2nd element of the pair is the password.
20328 (tailon-configuration-file
20329 (http-auth "basic")
20330 (users '(("user1" . "password1")
20331 ("user2" . "password2"))))
20338 @subsubheading Darkstat Service
20340 Darkstat is a packet sniffer that captures network traffic, calculates
20341 statistics about usage, and serves reports over HTTP.
20343 @defvar {Scheme Variable} darkstat-service-type
20344 This is the service type for the
20345 @uref{https://unix4lyfe.org/darkstat/, darkstat}
20346 service, its value must be a @code{darkstat-configuration} record as in
20350 (service darkstat-service-type
20351 (darkstat-configuration
20352 (interface "eno1")))
20356 @deftp {Data Type} darkstat-configuration
20357 Data type representing the configuration of @command{darkstat}.
20360 @item @code{package} (default: @code{darkstat})
20361 The darkstat package to use.
20363 @item @code{interface}
20364 Capture traffic on the specified network interface.
20366 @item @code{port} (default: @code{"667"})
20367 Bind the web interface to the specified port.
20369 @item @code{bind-address} (default: @code{"127.0.0.1"})
20370 Bind the web interface to the specified address.
20372 @item @code{base} (default: @code{"/"})
20373 Specify the path of the base URL. This can be useful if
20374 @command{darkstat} is accessed via a reverse proxy.
20379 @subsubheading Prometheus Node Exporter Service
20381 @cindex prometheus-node-exporter
20382 The Prometheus ``node exporter'' makes hardware and operating system statistics
20383 provided by the Linux kernel available for the Prometheus monitoring system.
20384 This service should be deployed on all physical nodes and virtual machines,
20385 where monitoring these statistics is desirable.
20387 @defvar {Scheme variable} prometheus-node-exporter-service-type
20388 This is the service type for the
20389 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
20390 service, its value must be a @code{prometheus-node-exporter-configuration}
20391 record as in this example:
20394 (service prometheus-node-exporter-service-type
20395 (prometheus-node-exporter-configuration
20396 (web-listen-address ":9100")))
20400 @deftp {Data Type} prometheus-node-exporter-configuration
20401 Data type representing the configuration of @command{node_exporter}.
20404 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
20405 The prometheus-node-exporter package to use.
20407 @item @code{web-listen-address} (default: @code{":9100"})
20408 Bind the web interface to the specified address.
20413 @subsubheading Zabbix server
20414 @cindex zabbix zabbix-server
20415 Zabbix provides monitoring metrics, among others network utilization, CPU load
20416 and disk space consumption:
20419 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
20420 @item Auto-discovery of servers and network devices and interfaces.
20421 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
20422 @item Distributed monitoring with centralized web administration.
20423 @item Native high performance agents.
20424 @item SLA, and ITIL KPI metrics on reporting.
20425 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
20426 @item Remote command execution through Zabbix proxies.
20429 @c %start of fragment
20431 Available @code{zabbix-server-configuration} fields are:
20433 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
20434 The zabbix-server package.
20438 @deftypevr {@code{zabbix-server-configuration} parameter} string user
20439 User who will run the Zabbix server.
20441 Defaults to @samp{"zabbix"}.
20445 @deftypevr {@code{zabbix-server-configuration} parameter} group group
20446 Group who will run the Zabbix server.
20448 Defaults to @samp{"zabbix"}.
20452 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
20453 Database host name.
20455 Defaults to @samp{"127.0.0.1"}.
20459 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
20462 Defaults to @samp{"zabbix"}.
20466 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
20469 Defaults to @samp{"zabbix"}.
20473 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
20474 Database password. Please, use @code{include-files} with
20475 @code{DBPassword=SECRET} inside a specified file instead.
20477 Defaults to @samp{""}.
20481 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
20484 Defaults to @samp{5432}.
20488 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
20489 Specifies where log messages are written to:
20493 @code{system} - syslog.
20496 @code{file} - file specified with @code{log-file} parameter.
20499 @code{console} - standard output.
20503 Defaults to @samp{""}.
20507 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
20508 Log file name for @code{log-type} @code{file} parameter.
20510 Defaults to @samp{"/var/log/zabbix/server.log"}.
20514 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
20517 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
20521 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
20522 The location of certificate authority (CA) files for SSL server
20523 certificate verification.
20525 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
20529 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
20530 Location of SSL client certificates.
20532 Defaults to @samp{"/etc/ssl/certs"}.
20536 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
20537 Extra options will be appended to Zabbix server configuration file.
20539 Defaults to @samp{""}.
20543 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
20544 You may include individual files or all files in a directory in the
20545 configuration file.
20547 Defaults to @samp{()}.
20551 @c %end of fragment
20553 @subsubheading Zabbix agent
20554 @cindex zabbix zabbix-agent
20556 Zabbix agent gathers information for Zabbix server.
20558 @c %start of fragment
20560 Available @code{zabbix-agent-configuration} fields are:
20562 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
20563 The zabbix-agent package.
20567 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
20568 User who will run the Zabbix agent.
20570 Defaults to @samp{"zabbix"}.
20574 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
20575 Group who will run the Zabbix agent.
20577 Defaults to @samp{"zabbix"}.
20581 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
20582 Unique, case sensitive hostname which is required for active checks and
20583 must match hostname as configured on the server.
20585 Defaults to @samp{"Zabbix server"}.
20589 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
20590 Specifies where log messages are written to:
20594 @code{system} - syslog.
20597 @code{file} - file specified with @code{log-file} parameter.
20600 @code{console} - standard output.
20604 Defaults to @samp{""}.
20608 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
20609 Log file name for @code{log-type} @code{file} parameter.
20611 Defaults to @samp{"/var/log/zabbix/agent.log"}.
20615 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
20618 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
20622 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
20623 List of IP addresses, optionally in CIDR notation, or hostnames of
20624 Zabbix servers and Zabbix proxies. Incoming connections will be
20625 accepted only from the hosts listed here.
20627 Defaults to @samp{("127.0.0.1")}.
20631 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
20632 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
20633 proxies for active checks. If port is not specified, default port is
20634 used. If this parameter is not specified, active checks are disabled.
20636 Defaults to @samp{("127.0.0.1")}.
20640 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
20641 Extra options will be appended to Zabbix server configuration file.
20643 Defaults to @samp{""}.
20647 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
20648 You may include individual files or all files in a directory in the
20649 configuration file.
20651 Defaults to @samp{()}.
20655 @c %end of fragment
20657 @subsubheading Zabbix front-end
20658 @cindex zabbix zabbix-front-end
20660 This service provides a WEB interface to Zabbix server.
20662 @c %start of fragment
20664 Available @code{zabbix-front-end-configuration} fields are:
20666 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
20667 NGINX configuration.
20671 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
20672 Database host name.
20674 Defaults to @samp{"localhost"}.
20678 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
20681 Defaults to @samp{5432}.
20685 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
20688 Defaults to @samp{"zabbix"}.
20692 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
20695 Defaults to @samp{"zabbix"}.
20699 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
20700 Database password. Please, use @code{db-secret-file} instead.
20702 Defaults to @samp{""}.
20706 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
20707 Secret file which will be appended to @file{zabbix.conf.php} file. This
20708 file contains credentials for use by Zabbix front-end. You are expected
20709 to create it manually.
20711 Defaults to @samp{""}.
20715 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
20716 Zabbix server hostname.
20718 Defaults to @samp{"localhost"}.
20722 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
20723 Zabbix server port.
20725 Defaults to @samp{10051}.
20730 @c %end of fragment
20732 @node Kerberos Services
20733 @subsection Kerberos Services
20736 The @code{(gnu services kerberos)} module provides services relating to
20737 the authentication protocol @dfn{Kerberos}.
20739 @subsubheading Krb5 Service
20741 Programs using a Kerberos client library normally
20742 expect a configuration file in @file{/etc/krb5.conf}.
20743 This service generates such a file from a definition provided in the
20744 operating system declaration.
20745 It does not cause any daemon to be started.
20747 No ``keytab'' files are provided by this service---you must explicitly create them.
20748 This service is known to work with the MIT client library, @code{mit-krb5}.
20749 Other implementations have not been tested.
20751 @defvr {Scheme Variable} krb5-service-type
20752 A service type for Kerberos 5 clients.
20756 Here is an example of its use:
20758 (service krb5-service-type
20759 (krb5-configuration
20760 (default-realm "EXAMPLE.COM")
20761 (allow-weak-crypto? #t)
20764 (name "EXAMPLE.COM")
20765 (admin-server "groucho.example.com")
20766 (kdc "karl.example.com"))
20769 (admin-server "kerb-admin.argrx.edu")
20770 (kdc "keys.argrx.edu"))))))
20774 This example provides a Kerberos@tie{}5 client configuration which:
20776 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
20777 of which have distinct administration servers and key distribution centers;
20778 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
20779 specified by clients;
20780 @item Accepts services which only support encryption types known to be weak.
20783 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
20784 Only the most commonly used ones are described here.
20785 For a full list, and more detailed explanation of each, see the MIT
20786 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
20790 @deftp {Data Type} krb5-realm
20791 @cindex realm, kerberos
20794 This field is a string identifying the name of the realm.
20795 A common convention is to use the fully qualified DNS name of your organization,
20796 converted to upper case.
20798 @item @code{admin-server}
20799 This field is a string identifying the host where the administration server is
20803 This field is a string identifying the key distribution center
20808 @deftp {Data Type} krb5-configuration
20811 @item @code{allow-weak-crypto?} (default: @code{#f})
20812 If this flag is @code{#t} then services which only offer encryption algorithms
20813 known to be weak will be accepted.
20815 @item @code{default-realm} (default: @code{#f})
20816 This field should be a string identifying the default Kerberos
20817 realm for the client.
20818 You should set this field to the name of your Kerberos realm.
20819 If this value is @code{#f}
20820 then a realm must be specified with every Kerberos principal when invoking programs
20821 such as @command{kinit}.
20823 @item @code{realms}
20824 This should be a non-empty list of @code{krb5-realm} objects, which clients may
20826 Normally, one of them will have a @code{name} field matching the @code{default-realm}
20832 @subsubheading PAM krb5 Service
20835 The @code{pam-krb5} service allows for login authentication and password
20836 management via Kerberos.
20837 You will need this service if you want PAM enabled applications to authenticate
20838 users using Kerberos.
20840 @defvr {Scheme Variable} pam-krb5-service-type
20841 A service type for the Kerberos 5 PAM module.
20844 @deftp {Data Type} pam-krb5-configuration
20845 Data type representing the configuration of the Kerberos 5 PAM module.
20846 This type has the following parameters:
20848 @item @code{pam-krb5} (default: @code{pam-krb5})
20849 The pam-krb5 package to use.
20851 @item @code{minimum-uid} (default: @code{1000})
20852 The smallest user ID for which Kerberos authentications should be attempted.
20853 Local accounts with lower values will silently fail to authenticate.
20858 @node LDAP Services
20859 @subsection LDAP Services
20861 @cindex nslcd, LDAP service
20863 The @code{(gnu services authentication)} module provides the
20864 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
20865 server. In addition to configuring the service itself, you may want to add
20866 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
20867 Switch} for detailed information.
20869 Here is a simple operating system declaration with a default configuration of
20870 the @code{nslcd-service-type} and a Name Service Switch configuration that
20871 consults the @code{ldap} name service last:
20874 (use-service-modules authentication)
20875 (use-modules (gnu system nss))
20881 (service nslcd-service-type)
20882 (service dhcp-client-service-type)
20884 (name-service-switch
20885 (let ((services (list (name-service (name "db"))
20886 (name-service (name "files"))
20887 (name-service (name "ldap")))))
20888 (name-service-switch
20889 (inherit %mdns-host-lookup-nss)
20890 (password services)
20893 (netgroup services)
20894 (gshadow services)))))
20897 @c %start of generated documentation for nslcd-configuration
20899 Available @code{nslcd-configuration} fields are:
20901 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
20902 The @code{nss-pam-ldapd} package to use.
20906 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
20907 The number of threads to start that can handle requests and perform LDAP
20908 queries. Each thread opens a separate connection to the LDAP server.
20909 The default is to start 5 threads.
20911 Defaults to @samp{disabled}.
20915 @deftypevr {@code{nslcd-configuration} parameter} string uid
20916 This specifies the user id with which the daemon should be run.
20918 Defaults to @samp{"nslcd"}.
20922 @deftypevr {@code{nslcd-configuration} parameter} string gid
20923 This specifies the group id with which the daemon should be run.
20925 Defaults to @samp{"nslcd"}.
20929 @deftypevr {@code{nslcd-configuration} parameter} log-option log
20930 This option controls the way logging is done via a list containing
20931 SCHEME and LEVEL. The SCHEME argument may either be the symbols
20932 @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
20933 argument is optional and specifies the log level. The log level may be
20934 one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
20935 @samp{notice}, @samp{info} or @samp{debug}. All messages with the
20936 specified log level or higher are logged.
20938 Defaults to @samp{("/var/log/nslcd" info)}.
20942 @deftypevr {@code{nslcd-configuration} parameter} list uri
20943 The list of LDAP server URIs. Normally, only the first server will be
20944 used with the following servers as fall-back.
20946 Defaults to @samp{("ldap://localhost:389/")}.
20950 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
20951 The version of the LDAP protocol to use. The default is to use the
20952 maximum version supported by the LDAP library.
20954 Defaults to @samp{disabled}.
20958 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
20959 Specifies the distinguished name with which to bind to the directory
20960 server for lookups. The default is to bind anonymously.
20962 Defaults to @samp{disabled}.
20966 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
20967 Specifies the credentials with which to bind. This option is only
20968 applicable when used with binddn.
20970 Defaults to @samp{disabled}.
20974 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
20975 Specifies the distinguished name to use when the root user tries to
20976 modify a user's password using the PAM module.
20978 Defaults to @samp{disabled}.
20982 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
20983 Specifies the credentials with which to bind if the root user tries to
20984 change a user's password. This option is only applicable when used with
20987 Defaults to @samp{disabled}.
20991 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
20992 Specifies the SASL mechanism to be used when performing SASL
20995 Defaults to @samp{disabled}.
20999 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
21000 Specifies the SASL realm to be used when performing SASL authentication.
21002 Defaults to @samp{disabled}.
21006 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
21007 Specifies the authentication identity to be used when performing SASL
21010 Defaults to @samp{disabled}.
21014 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
21015 Specifies the authorization identity to be used when performing SASL
21018 Defaults to @samp{disabled}.
21022 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
21023 Determines whether the LDAP server host name should be canonicalised. If
21024 this is enabled the LDAP library will do a reverse host name lookup. By
21025 default, it is left up to the LDAP library whether this check is
21028 Defaults to @samp{disabled}.
21032 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
21033 Set the name for the GSS-API Kerberos credentials cache.
21035 Defaults to @samp{disabled}.
21039 @deftypevr {@code{nslcd-configuration} parameter} string base
21040 The directory search base.
21042 Defaults to @samp{"dc=example,dc=com"}.
21046 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
21047 Specifies the search scope (subtree, onelevel, base or children). The
21048 default scope is subtree; base scope is almost never useful for name
21049 service lookups; children scope is not supported on all servers.
21051 Defaults to @samp{(subtree)}.
21055 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
21056 Specifies the policy for dereferencing aliases. The default policy is
21057 to never dereference aliases.
21059 Defaults to @samp{disabled}.
21063 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
21064 Specifies whether automatic referral chasing should be enabled. The
21065 default behaviour is to chase referrals.
21067 Defaults to @samp{disabled}.
21071 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
21072 This option allows for custom attributes to be looked up instead of the
21073 default RFC 2307 attributes. It is a list of maps, each consisting of
21074 the name of a map, the RFC 2307 attribute to match and the query
21075 expression for the attribute as it is available in the directory.
21077 Defaults to @samp{()}.
21081 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
21082 A list of filters consisting of the name of a map to which the filter
21083 applies and an LDAP search filter expression.
21085 Defaults to @samp{()}.
21089 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
21090 Specifies the time limit in seconds to use when connecting to the
21091 directory server. The default value is 10 seconds.
21093 Defaults to @samp{disabled}.
21097 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
21098 Specifies the time limit (in seconds) to wait for a response from the
21099 LDAP server. A value of zero, which is the default, is to wait
21100 indefinitely for searches to be completed.
21102 Defaults to @samp{disabled}.
21106 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
21107 Specifies the period if inactivity (in seconds) after which the con‐
21108 nection to the LDAP server will be closed. The default is not to time
21111 Defaults to @samp{disabled}.
21115 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
21116 Specifies the number of seconds to sleep when connecting to all LDAP
21117 servers fails. By default one second is waited between the first
21118 failure and the first retry.
21120 Defaults to @samp{disabled}.
21124 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
21125 Specifies the time after which the LDAP server is considered to be
21126 permanently unavailable. Once this time is reached retries will be done
21127 only once per this time period. The default value is 10 seconds.
21129 Defaults to @samp{disabled}.
21133 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
21134 Specifies whether to use SSL/TLS or not (the default is not to). If
21135 'start-tls is specified then StartTLS is used rather than raw LDAP over
21138 Defaults to @samp{disabled}.
21142 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
21143 Specifies what checks to perform on a server-supplied certificate. The
21144 meaning of the values is described in the ldap.conf(5) manual page.
21146 Defaults to @samp{disabled}.
21150 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
21151 Specifies the directory containing X.509 certificates for peer authen‐
21152 tication. This parameter is ignored when using GnuTLS.
21154 Defaults to @samp{disabled}.
21158 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
21159 Specifies the path to the X.509 certificate for peer authentication.
21161 Defaults to @samp{disabled}.
21165 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
21166 Specifies the path to an entropy source. This parameter is ignored when
21169 Defaults to @samp{disabled}.
21173 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
21174 Specifies the ciphers to use for TLS as a string.
21176 Defaults to @samp{disabled}.
21180 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
21181 Specifies the path to the file containing the local certificate for
21182 client TLS authentication.
21184 Defaults to @samp{disabled}.
21188 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
21189 Specifies the path to the file containing the private key for client TLS
21192 Defaults to @samp{disabled}.
21196 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
21197 Set this to a number greater than 0 to request paged results from the
21198 LDAP server in accordance with RFC2696. The default (0) is to not
21199 request paged results.
21201 Defaults to @samp{disabled}.
21205 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
21206 This option prevents group membership lookups through LDAP for the
21207 specified users. Alternatively, the value 'all-local may be used. With
21208 that value nslcd builds a full list of non-LDAP users on startup.
21210 Defaults to @samp{disabled}.
21214 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
21215 This option ensures that LDAP users with a numeric user id lower than
21216 the specified value are ignored.
21218 Defaults to @samp{disabled}.
21222 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
21223 This option specifies an offset that is added to all LDAP numeric user
21224 ids. This can be used to avoid user id collisions with local users.
21226 Defaults to @samp{disabled}.
21230 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
21231 This option specifies an offset that is added to all LDAP numeric group
21232 ids. This can be used to avoid user id collisions with local groups.
21234 Defaults to @samp{disabled}.
21238 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
21239 If this option is set, the member attribute of a group may point to
21240 another group. Members of nested groups are also returned in the higher
21241 level group and parent groups are returned when finding groups for a
21242 specific user. The default is not to perform extra searches for nested
21245 Defaults to @samp{disabled}.
21249 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
21250 If this option is set, the group member list is not retrieved when
21251 looking up groups. Lookups for finding which groups a user belongs to
21252 will remain functional so the user will likely still get the correct
21253 groups assigned on login.
21255 Defaults to @samp{disabled}.
21259 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
21260 If this option is set, functions which cause all user/group entries to
21261 be loaded from the directory will not succeed in doing so. This can
21262 dramatically reduce LDAP server load in situations where there are a
21263 great number of users and/or groups. This option is not recommended for
21264 most configurations.
21266 Defaults to @samp{disabled}.
21270 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
21271 This option can be used to specify how user and group names are verified
21272 within the system. This pattern is used to check all user and group
21273 names that are requested and returned from LDAP.
21275 Defaults to @samp{disabled}.
21279 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
21280 This specifies whether or not to perform searches using case-insensitive
21281 matching. Enabling this could open up the system to authorization
21282 bypass vulnerabilities and introduce nscd cache poisoning
21283 vulnerabilities which allow denial of service.
21285 Defaults to @samp{disabled}.
21289 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
21290 This option specifies whether password policy controls are requested and
21291 handled from the LDAP server when performing user authentication.
21293 Defaults to @samp{disabled}.
21297 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
21298 By default nslcd performs an LDAP search with the user's credentials
21299 after BIND (authentication) to ensure that the BIND operation was
21300 successful. The default search is a simple check to see if the user's
21301 DN exists. A search filter can be specified that will be used instead.
21302 It should return at least one entry.
21304 Defaults to @samp{disabled}.
21308 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
21309 This option allows flexible fine tuning of the authorisation check that
21310 should be performed. The search filter specified is executed and if any
21311 entries match, access is granted, otherwise access is denied.
21313 Defaults to @samp{disabled}.
21317 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
21318 If this option is set password modification using pam_ldap will be
21319 denied and the specified message will be presented to the user instead.
21320 The message can be used to direct the user to an alternative means of
21321 changing their password.
21323 Defaults to @samp{disabled}.
21327 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
21328 List of pam service names for which LDAP authentication should suffice.
21330 Defaults to @samp{()}.
21334 @c %end of generated documentation for nslcd-configuration
21338 @subsection Web Services
21343 The @code{(gnu services web)} module provides the Apache HTTP Server,
21344 the nginx web server, and also a fastcgi wrapper daemon.
21346 @subsubheading Apache HTTP Server
21348 @deffn {Scheme Variable} httpd-service-type
21349 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
21350 (@dfn{httpd}). The value for this service type is a
21351 @code{httpd-configuration} record.
21353 A simple example configuration is given below.
21356 (service httpd-service-type
21357 (httpd-configuration
21360 (server-name "www.example.com")
21361 (document-root "/srv/http/www.example.com")))))
21364 Other services can also extend the @code{httpd-service-type} to add to
21368 (simple-service 'www.example.com-server httpd-service-type
21372 (list (string-join '("ServerName www.example.com"
21373 "DocumentRoot /srv/http/www.example.com")
21378 The details for the @code{httpd-configuration}, @code{httpd-module},
21379 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
21382 @deffn {Data Type} httpd-configuration
21383 This data type represents the configuration for the httpd service.
21386 @item @code{package} (default: @code{httpd})
21387 The httpd package to use.
21389 @item @code{pid-file} (default: @code{"/var/run/httpd"})
21390 The pid file used by the shepherd-service.
21392 @item @code{config} (default: @code{(httpd-config-file)})
21393 The configuration file to use with the httpd service. The default value
21394 is a @code{httpd-config-file} record, but this can also be a different
21395 G-expression that generates a file, for example a @code{plain-file}. A
21396 file outside of the store can also be specified through a string.
21401 @deffn {Data Type} httpd-module
21402 This data type represents a module for the httpd service.
21406 The name of the module.
21409 The file for the module. This can be relative to the httpd package being
21410 used, the absolute location of a file, or a G-expression for a file
21411 within the store, for example @code{(file-append mod-wsgi
21412 "/modules/mod_wsgi.so")}.
21417 @defvr {Scheme Variable} %default-httpd-modules
21418 A default list of @code{httpd-module} objects.
21421 @deffn {Data Type} httpd-config-file
21422 This data type represents a configuration file for the httpd service.
21425 @item @code{modules} (default: @code{%default-httpd-modules})
21426 The modules to load. Additional modules can be added here, or loaded by
21427 additional configuration.
21429 For example, in order to handle requests for PHP files, you can use Apache’s
21430 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
21433 (service httpd-service-type
21434 (httpd-configuration
21439 (name "proxy_module")
21440 (file "modules/mod_proxy.so"))
21442 (name "proxy_fcgi_module")
21443 (file "modules/mod_proxy_fcgi.so"))
21444 %default-httpd-modules))
21445 (extra-config (list "\
21446 <FilesMatch \\.php$>
21447 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
21448 </FilesMatch>"))))))
21449 (service php-fpm-service-type
21450 (php-fpm-configuration
21451 (socket "/var/run/php-fpm.sock")
21452 (socket-group "httpd")))
21455 @item @code{server-root} (default: @code{httpd})
21456 The @code{ServerRoot} in the configuration file, defaults to the httpd
21457 package. Directives including @code{Include} and @code{LoadModule} are
21458 taken as relative to the server root.
21460 @item @code{server-name} (default: @code{#f})
21461 The @code{ServerName} in the configuration file, used to specify the
21462 request scheme, hostname and port that the server uses to identify
21465 This doesn't need to be set in the server config, and can be specified
21466 in virtual hosts. The default is @code{#f} to not specify a
21469 @item @code{document-root} (default: @code{"/srv/http"})
21470 The @code{DocumentRoot} from which files will be served.
21472 @item @code{listen} (default: @code{'("80")})
21473 The list of values for the @code{Listen} directives in the config
21474 file. The value should be a list of strings, when each string can
21475 specify the port number to listen on, and optionally the IP address and
21478 @item @code{pid-file} (default: @code{"/var/run/httpd"})
21479 The @code{PidFile} to use. This should match the @code{pid-file} set in
21480 the @code{httpd-configuration} so that the Shepherd service is
21481 configured correctly.
21483 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
21484 The @code{ErrorLog} to which the server will log errors.
21486 @item @code{user} (default: @code{"httpd"})
21487 The @code{User} which the server will answer requests as.
21489 @item @code{group} (default: @code{"httpd"})
21490 The @code{Group} which the server will answer requests as.
21492 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
21493 A flat list of strings and G-expressions which will be added to the end
21494 of the configuration file.
21496 Any values which the service is extended with will be appended to this
21502 @deffn {Data Type} httpd-virtualhost
21503 This data type represents a virtualhost configuration block for the httpd service.
21505 These should be added to the extra-config for the httpd-service.
21508 (simple-service 'www.example.com-server httpd-service-type
21512 (list (string-join '("ServerName www.example.com"
21513 "DocumentRoot /srv/http/www.example.com")
21518 @item @code{addresses-and-ports}
21519 The addresses and ports for the @code{VirtualHost} directive.
21521 @item @code{contents}
21522 The contents of the @code{VirtualHost} directive, this should be a list
21523 of strings and G-expressions.
21528 @subsubheading NGINX
21530 @deffn {Scheme Variable} nginx-service-type
21531 Service type for the @uref{https://nginx.org/,NGinx} web server. The
21532 value for this service type is a @code{<nginx-configuration>} record.
21534 A simple example configuration is given below.
21537 (service nginx-service-type
21538 (nginx-configuration
21540 (list (nginx-server-configuration
21541 (server-name '("www.example.com"))
21542 (root "/srv/http/www.example.com"))))))
21545 In addition to adding server blocks to the service configuration
21546 directly, this service can be extended by other services to add server
21547 blocks, as in this example:
21550 (simple-service 'my-extra-server nginx-service-type
21551 (list (nginx-server-configuration
21552 (root "/srv/http/extra-website")
21553 (try-files (list "$uri" "$uri/index.html")))))
21557 At startup, @command{nginx} has not yet read its configuration file, so
21558 it uses a default file to log error messages. If it fails to load its
21559 configuration file, that is where error messages are logged. After the
21560 configuration file is loaded, the default error log file changes as per
21561 configuration. In our case, startup error messages can be found in
21562 @file{/var/run/nginx/logs/error.log}, and after configuration in
21563 @file{/var/log/nginx/error.log}. The second location can be changed
21564 with the @var{log-directory} configuration option.
21566 @deffn {Data Type} nginx-configuration
21567 This data type represents the configuration for NGinx. Some
21568 configuration can be done through this and the other provided record
21569 types, or alternatively, a config file can be provided.
21572 @item @code{nginx} (default: @code{nginx})
21573 The nginx package to use.
21575 @item @code{log-directory} (default: @code{"/var/log/nginx"})
21576 The directory to which NGinx will write log files.
21578 @item @code{run-directory} (default: @code{"/var/run/nginx"})
21579 The directory in which NGinx will create a pid file, and write temporary
21582 @item @code{server-blocks} (default: @code{'()})
21583 A list of @dfn{server blocks} to create in the generated configuration
21584 file, the elements should be of type
21585 @code{<nginx-server-configuration>}.
21587 The following example would setup NGinx to serve @code{www.example.com}
21588 from the @code{/srv/http/www.example.com} directory, without using
21591 (service nginx-service-type
21592 (nginx-configuration
21594 (list (nginx-server-configuration
21595 (server-name '("www.example.com"))
21596 (root "/srv/http/www.example.com"))))))
21599 @item @code{upstream-blocks} (default: @code{'()})
21600 A list of @dfn{upstream blocks} to create in the generated configuration
21601 file, the elements should be of type
21602 @code{<nginx-upstream-configuration>}.
21604 Configuring upstreams through the @code{upstream-blocks} can be useful
21605 when combined with @code{locations} in the
21606 @code{<nginx-server-configuration>} records. The following example
21607 creates a server configuration with one location configuration, that
21608 will proxy requests to a upstream configuration, which will handle
21609 requests with two servers.
21614 (nginx-configuration
21616 (list (nginx-server-configuration
21617 (server-name '("www.example.com"))
21618 (root "/srv/http/www.example.com")
21621 (nginx-location-configuration
21623 (body '("proxy_pass http://server-proxy;"))))))))
21625 (list (nginx-upstream-configuration
21626 (name "server-proxy")
21627 (servers (list "server1.example.com"
21628 "server2.example.com")))))))
21631 @item @code{file} (default: @code{#f})
21632 If a configuration @var{file} is provided, this will be used, rather than
21633 generating a configuration file from the provided @code{log-directory},
21634 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
21635 proper operation, these arguments should match what is in @var{file} to ensure
21636 that the directories are created when the service is activated.
21638 This can be useful if you have an existing configuration file, or it's
21639 not possible to do what is required through the other parts of the
21640 nginx-configuration record.
21642 @item @code{server-names-hash-bucket-size} (default: @code{#f})
21643 Bucket size for the server names hash tables, defaults to @code{#f} to
21644 use the size of the processors cache line.
21646 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
21647 Maximum bucket size for the server names hash tables.
21649 @item @code{modules} (default: @code{'()})
21650 List of nginx dynamic modules to load. This should be a list of file
21651 names of loadable modules, as in this example:
21656 (file-append nginx-accept-language-module "\
21657 /etc/nginx/modules/ngx_http_accept_language_module.so")))
21660 @item @code{global-directives} (default: @code{'((events . ()))})
21661 Association list of global directives for the top level of the nginx
21662 configuration. Values may themselves be association lists.
21666 `((worker_processes . 16)
21668 (events . ((worker_connections . 1024)))))
21671 @item @code{extra-content} (default: @code{""})
21672 Extra content for the @code{http} block. Should be string or a string
21673 valued G-expression.
21678 @deftp {Data Type} nginx-server-configuration
21679 Data type representing the configuration of an nginx server block.
21680 This type has the following parameters:
21683 @item @code{listen} (default: @code{'("80" "443 ssl")})
21684 Each @code{listen} directive sets the address and port for IP, or the
21685 path for a UNIX-domain socket on which the server will accept requests.
21686 Both address and port, or only address or only port can be specified.
21687 An address may also be a hostname, for example:
21690 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
21693 @item @code{server-name} (default: @code{(list 'default)})
21694 A list of server names this server represents. @code{'default} represents the
21695 default server for connections matching no other server.
21697 @item @code{root} (default: @code{"/srv/http"})
21698 Root of the website nginx will serve.
21700 @item @code{locations} (default: @code{'()})
21701 A list of @dfn{nginx-location-configuration} or
21702 @dfn{nginx-named-location-configuration} records to use within this
21705 @item @code{index} (default: @code{(list "index.html")})
21706 Index files to look for when clients ask for a directory. If it cannot be found,
21707 Nginx will send the list of files in the directory.
21709 @item @code{try-files} (default: @code{'()})
21710 A list of files whose existence is checked in the specified order.
21711 @code{nginx} will use the first file it finds to process the request.
21713 @item @code{ssl-certificate} (default: @code{#f})
21714 Where to find the certificate for secure connections. Set it to @code{#f} if
21715 you don't have a certificate or you don't want to use HTTPS.
21717 @item @code{ssl-certificate-key} (default: @code{#f})
21718 Where to find the private key for secure connections. Set it to @code{#f} if
21719 you don't have a key or you don't want to use HTTPS.
21721 @item @code{server-tokens?} (default: @code{#f})
21722 Whether the server should add its configuration to response.
21724 @item @code{raw-content} (default: @code{'()})
21725 A list of raw lines added to the server block.
21730 @deftp {Data Type} nginx-upstream-configuration
21731 Data type representing the configuration of an nginx @code{upstream}
21732 block. This type has the following parameters:
21736 Name for this group of servers.
21738 @item @code{servers}
21739 Specify the addresses of the servers in the group. The address can be
21740 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
21741 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
21742 prefix @samp{unix:}. For addresses using an IP address or domain name,
21743 the default port is 80, and a different port can be specified
21749 @deftp {Data Type} nginx-location-configuration
21750 Data type representing the configuration of an nginx @code{location}
21751 block. This type has the following parameters:
21755 URI which this location block matches.
21757 @anchor{nginx-location-configuration body}
21759 Body of the location block, specified as a list of strings. This can contain
21761 configuration directives. For example, to pass requests to a upstream
21762 server group defined using an @code{nginx-upstream-configuration} block,
21763 the following directive would be specified in the body @samp{(list "proxy_pass
21764 http://upstream-name;")}.
21769 @deftp {Data Type} nginx-named-location-configuration
21770 Data type representing the configuration of an nginx named location
21771 block. Named location blocks are used for request redirection, and not
21772 used for regular request processing. This type has the following
21777 Name to identify this location block.
21780 @xref{nginx-location-configuration body}, as the body for named location
21781 blocks can be used in a similar way to the
21782 @code{nginx-location-configuration body}. One restriction is that the
21783 body of a named location block cannot contain location blocks.
21788 @subsubheading Varnish Cache
21790 Varnish is a fast cache server that sits in between web applications
21791 and end users. It proxies requests from clients and caches the
21792 accessed URLs such that multiple requests for the same resource only
21793 creates one request to the back-end.
21795 @defvr {Scheme Variable} varnish-service-type
21796 Service type for the Varnish daemon.
21799 @deftp {Data Type} varnish-configuration
21800 Data type representing the @code{varnish} service configuration.
21801 This type has the following parameters:
21804 @item @code{package} (default: @code{varnish})
21805 The Varnish package to use.
21807 @item @code{name} (default: @code{"default"})
21808 A name for this Varnish instance. Varnish will create a directory in
21809 @file{/var/varnish/} with this name and keep temporary files there. If
21810 the name starts with a forward slash, it is interpreted as an absolute
21813 Pass the @code{-n} argument to other Varnish programs to connect to the
21814 named instance, e.g.@: @command{varnishncsa -n default}.
21816 @item @code{backend} (default: @code{"localhost:8080"})
21817 The backend to use. This option has no effect if @code{vcl} is set.
21819 @item @code{vcl} (default: #f)
21820 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
21821 is @code{#f}, Varnish will proxy @code{backend} using the default
21822 configuration. Otherwise this must be a file-like object with valid
21825 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
21826 For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
21827 can do something along these lines:
21830 (define %gnu-mirror
21831 (plain-file "gnu.vcl"
21833 backend gnu @{ .host = \"www.gnu.org\"; @}"))
21837 (services (cons (service varnish-service-type
21838 (varnish-configuration
21840 (vcl %gnu-mirror)))
21844 The configuration of an already running Varnish instance can be inspected
21845 and changed using the @command{varnishadm} program.
21847 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
21848 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
21849 comprehensive documentation on Varnish and its configuration language.
21851 @item @code{listen} (default: @code{'("localhost:80")})
21852 List of addresses Varnish will listen on.
21854 @item @code{storage} (default: @code{'("malloc,128m")})
21855 List of storage backends that will be available in VCL.
21857 @item @code{parameters} (default: @code{'()})
21858 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
21860 @item @code{extra-options} (default: @code{'()})
21861 Additional arguments to pass to the @command{varnishd} process.
21866 @subsubheading Patchwork
21868 Patchwork is a patch tracking system. It can collect patches sent to a
21869 mailing list, and display them in a web interface.
21871 @defvr {Scheme Variable} patchwork-service-type
21872 Service type for Patchwork.
21875 The following example is an example of a minimal service for Patchwork, for
21876 the @code{patchwork.example.com} domain.
21879 (service patchwork-service-type
21880 (patchwork-configuration
21881 (domain "patchwork.example.com")
21883 (patchwork-settings-module
21884 (allowed-hosts (list domain))
21885 (default-from-email "patchwork@@patchwork.example.com")))
21886 (getmail-retriever-config
21887 (getmail-retriever-configuration
21888 (type "SimpleIMAPSSLRetriever")
21889 (server "imap.example.com")
21891 (username "patchwork")
21893 (list (file-append coreutils "/bin/cat")
21894 "/etc/getmail-patchwork-imap-password"))
21896 '((mailboxes . ("Patches"))))))))
21900 There are three records for configuring the Patchwork service. The
21901 @code{<patchwork-configuration>} relates to the configuration for Patchwork
21902 within the HTTPD service.
21904 The @code{settings-module} field within the @code{<patchwork-configuration>}
21905 record can be populated with the @code{<patchwork-settings-module>} record,
21906 which describes a settings module that is generated within the Guix store.
21908 For the @code{database-configuration} field within the
21909 @code{<patchwork-settings-module>}, the
21910 @code{<patchwork-database-configuration>} must be used.
21912 @deftp {Data Type} patchwork-configuration
21913 Data type representing the Patchwork service configuration. This type has the
21914 following parameters:
21917 @item @code{patchwork} (default: @code{patchwork})
21918 The Patchwork package to use.
21920 @item @code{domain}
21921 The domain to use for Patchwork, this is used in the HTTPD service virtual
21924 @item @code{settings-module}
21925 The settings module to use for Patchwork. As a Django application, Patchwork
21926 is configured with a Python module containing the settings. This can either be
21927 an instance of the @code{<patchwork-settings-module>} record, any other record
21928 that represents the settings in the store, or a directory outside of the
21931 @item @code{static-path} (default: @code{"/static/"})
21932 The path under which the HTTPD service should serve the static files.
21934 @item @code{getmail-retriever-config}
21935 The getmail-retriever-configuration record value to use with
21936 Patchwork. Getmail will be configured with this value, the messages will be
21937 delivered to Patchwork.
21942 @deftp {Data Type} patchwork-settings-module
21943 Data type representing a settings module for Patchwork. Some of these
21944 settings relate directly to Patchwork, but others relate to Django, the web
21945 framework used by Patchwork, or the Django Rest Framework library. This type
21946 has the following parameters:
21949 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
21950 The database connection settings used for Patchwork. See the
21951 @code{<patchwork-database-configuration>} record type for more information.
21953 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
21954 Patchwork, as a Django web application uses a secret key for cryptographically
21955 signing values. This file should contain a unique unpredictable value.
21957 If this file does not exist, it will be created and populated with a random
21958 value by the patchwork-setup shepherd service.
21960 This setting relates to Django.
21962 @item @code{allowed-hosts}
21963 A list of valid hosts for this Patchwork service. This should at least include
21964 the domain specified in the @code{<patchwork-configuration>} record.
21966 This is a Django setting.
21968 @item @code{default-from-email}
21969 The email address from which Patchwork should send email by default.
21971 This is a Patchwork setting.
21973 @item @code{static-url} (default: @code{#f})
21974 The URL to use when serving static assets. It can be part of a URL, or a full
21975 URL, but must end in a @code{/}.
21977 If the default value is used, the @code{static-path} value from the
21978 @code{<patchwork-configuration>} record will be used.
21980 This is a Django setting.
21982 @item @code{admins} (default: @code{'()})
21983 Email addresses to send the details of errors that occur. Each value should
21984 be a list containing two elements, the name and then the email address.
21986 This is a Django setting.
21988 @item @code{debug?} (default: @code{#f})
21989 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
21990 messages will be shown.
21992 This is a Django setting.
21994 @item @code{enable-rest-api?} (default: @code{#t})
21995 Whether to enable the Patchwork REST API.
21997 This is a Patchwork setting.
21999 @item @code{enable-xmlrpc?} (default: @code{#t})
22000 Whether to enable the XML RPC API.
22002 This is a Patchwork setting.
22004 @item @code{force-https-links?} (default: @code{#t})
22005 Whether to use HTTPS links on Patchwork pages.
22007 This is a Patchwork setting.
22009 @item @code{extra-settings} (default: @code{""})
22010 Extra code to place at the end of the Patchwork settings module.
22015 @deftp {Data Type} patchwork-database-configuration
22016 Data type representing the database configuration for Patchwork.
22019 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
22020 The database engine to use.
22022 @item @code{name} (default: @code{"patchwork"})
22023 The name of the database to use.
22025 @item @code{user} (default: @code{"httpd"})
22026 The user to connect to the database as.
22028 @item @code{password} (default: @code{""})
22029 The password to use when connecting to the database.
22031 @item @code{host} (default: @code{""})
22032 The host to make the database connection to.
22034 @item @code{port} (default: @code{""})
22035 The port on which to connect to the database.
22040 @subsubheading Mumi
22042 @cindex Mumi, Debbugs Web interface
22043 @cindex Debbugs, Mumi Web interface
22044 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
22045 Web interface to the Debbugs bug tracker, by default for
22046 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
22047 but it also fetches and indexes mail retrieved from Debbugs.
22049 @defvr {Scheme Variable} mumi-service-type
22050 This is the service type for Mumi.
22053 @deftp {Data Type} mumi-configuration
22054 Data type representing the Mumi service configuration. This type has the
22058 @item @code{mumi} (default: @code{mumi})
22059 The Mumi package to use.
22061 @item @code{mailer?} (default: @code{#true})
22062 Whether to enable or disable the mailer component.
22064 @item @code{mumi-configuration-sender}
22065 The email address used as the sender for comments.
22067 @item @code{mumi-configuration-smtp}
22068 A URI to configure the SMTP settings for Mailutils. This could be
22069 something like @code{sendmail:///path/to/bin/msmtp} or any other URI
22070 supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
22071 mailutils, GNU@tie{}Mailutils}.
22077 @subsubheading FastCGI
22080 FastCGI is an interface between the front-end and the back-end of a web
22081 service. It is a somewhat legacy facility; new web services should
22082 generally just talk HTTP between the front-end and the back-end.
22083 However there are a number of back-end services such as PHP or the
22084 optimized HTTP Git repository access that use FastCGI, so we have
22085 support for it in Guix.
22087 To use FastCGI, you configure the front-end web server (e.g., nginx) to
22088 dispatch some subset of its requests to the fastcgi backend, which
22089 listens on a local TCP or UNIX socket. There is an intermediary
22090 @code{fcgiwrap} program that sits between the actual backend process and
22091 the web server. The front-end indicates which backend program to run,
22092 passing that information to the @code{fcgiwrap} process.
22094 @defvr {Scheme Variable} fcgiwrap-service-type
22095 A service type for the @code{fcgiwrap} FastCGI proxy.
22098 @deftp {Data Type} fcgiwrap-configuration
22099 Data type representing the configuration of the @code{fcgiwrap} service.
22100 This type has the following parameters:
22102 @item @code{package} (default: @code{fcgiwrap})
22103 The fcgiwrap package to use.
22105 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
22106 The socket on which the @code{fcgiwrap} process should listen, as a
22107 string. Valid @var{socket} values include
22108 @code{unix:@var{/path/to/unix/socket}},
22109 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
22110 @code{tcp6:[@var{ipv6_addr}]:port}.
22112 @item @code{user} (default: @code{fcgiwrap})
22113 @itemx @code{group} (default: @code{fcgiwrap})
22114 The user and group names, as strings, under which to run the
22115 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
22116 the user asks for the specific user or group names @code{fcgiwrap} that
22117 the corresponding user and/or group is present on the system.
22119 It is possible to configure a FastCGI-backed web service to pass HTTP
22120 authentication information from the front-end to the back-end, and to
22121 allow @code{fcgiwrap} to run the back-end process as a corresponding
22122 local user. To enable this capability on the back-end, run
22123 @code{fcgiwrap} as the @code{root} user and group. Note that this
22124 capability also has to be configured on the front-end as well.
22129 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
22130 with some additional features useful for sites of any size.
22132 These features include:
22134 @item Adaptive process spawning
22135 @item Basic statistics (similar to Apache's mod_status)
22136 @item Advanced process management with graceful stop/start
22137 @item Ability to start workers with different uid/gid/chroot/environment
22138 and different php.ini (replaces safe_mode)
22139 @item Stdout & stderr logging
22140 @item Emergency restart in case of accidental opcode cache destruction
22141 @item Accelerated upload support
22142 @item Support for a "slowlog"
22143 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
22144 a special function to finish request & flush all data while continuing to do
22145 something time-consuming (video converting, stats processing, etc.)
22147 ...@: and much more.
22149 @defvr {Scheme Variable} php-fpm-service-type
22150 A Service type for @code{php-fpm}.
22153 @deftp {Data Type} php-fpm-configuration
22154 Data Type for php-fpm service configuration.
22156 @item @code{php} (default: @code{php})
22157 The php package to use.
22158 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
22159 The address on which to accept FastCGI requests. Valid syntaxes are:
22161 @item @code{"ip.add.re.ss:port"}
22162 Listen on a TCP socket to a specific address on a specific port.
22163 @item @code{"port"}
22164 Listen on a TCP socket to all addresses on a specific port.
22165 @item @code{"/path/to/unix/socket"}
22166 Listen on a unix socket.
22169 @item @code{user} (default: @code{php-fpm})
22170 User who will own the php worker processes.
22171 @item @code{group} (default: @code{php-fpm})
22172 Group of the worker processes.
22173 @item @code{socket-user} (default: @code{php-fpm})
22174 User who can speak to the php-fpm socket.
22175 @item @code{socket-group} (default: @code{nginx})
22176 Group that can speak to the php-fpm socket.
22177 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
22178 The process id of the php-fpm process is written to this file
22179 once the service has started.
22180 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
22181 Log for the php-fpm master process.
22182 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
22183 Detailed settings for the php-fpm process manager.
22186 @item @code{<php-fpm-dynamic-process-manager-configuration>}
22187 @item @code{<php-fpm-static-process-manager-configuration>}
22188 @item @code{<php-fpm-on-demand-process-manager-configuration>}
22190 @item @code{display-errors} (default @code{#f})
22191 Determines whether php errors and warning should be sent to clients
22192 and displayed in their browsers.
22193 This is useful for local php development, but a security risk for public sites,
22194 as error messages can reveal passwords and personal data.
22195 @item @code{timezone} (default @code{#f})
22196 Specifies @code{php_admin_value[date.timezone]} parameter.
22197 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
22198 This file will log the @code{stderr} outputs of php worker processes.
22199 Can be set to @code{#f} to disable logging.
22200 @item @code{file} (default @code{#f})
22201 An optional override of the whole configuration.
22202 You can use the @code{mixed-text-file} function or an absolute filepath for it.
22203 @item @code{php-ini-file} (default @code{#f})
22204 An optional override of the default php settings.
22205 It may be any ``file-like'' object (@pxref{G-Expressions, file-like objects}).
22206 You can use the @code{mixed-text-file} function or an absolute filepath for it.
22208 For local development it is useful to set a higher timeout and memory
22209 limit for spawned php processes. This be accomplished with the
22210 following operating system configuration snippet:
22212 (define %local-php-ini
22213 (plain-file "php.ini"
22215 max_execution_time = 1800"))
22219 (services (cons (service php-fpm-service-type
22220 (php-fpm-configuration
22221 (php-ini-file %local-php-ini)))
22225 Consult the @url{https://www.php.net/manual/en/ini.core.php,core php.ini
22226 directives} for comprehensive documentation on the acceptable
22227 @file{php.ini} directives.
22231 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
22232 Data Type for the @code{dynamic} php-fpm process manager. With the
22233 @code{dynamic} process manager, spare worker processes are kept around
22234 based on it's configured limits.
22236 @item @code{max-children} (default: @code{5})
22237 Maximum of worker processes.
22238 @item @code{start-servers} (default: @code{2})
22239 How many worker processes should be started on start-up.
22240 @item @code{min-spare-servers} (default: @code{1})
22241 How many spare worker processes should be kept around at minimum.
22242 @item @code{max-spare-servers} (default: @code{3})
22243 How many spare worker processes should be kept around at maximum.
22247 @deftp {Data type} php-fpm-static-process-manager-configuration
22248 Data Type for the @code{static} php-fpm process manager. With the
22249 @code{static} process manager, an unchanging number of worker processes
22252 @item @code{max-children} (default: @code{5})
22253 Maximum of worker processes.
22257 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
22258 Data Type for the @code{on-demand} php-fpm process manager. With the
22259 @code{on-demand} process manager, worker processes are only created as
22262 @item @code{max-children} (default: @code{5})
22263 Maximum of worker processes.
22264 @item @code{process-idle-timeout} (default: @code{10})
22265 The time in seconds after which a process with no requests is killed.
22270 @deffn {Scheme Procedure} nginx-php-location @
22271 [#:nginx-package nginx] @
22272 [socket (string-append "/var/run/php" @
22273 (version-major (package-version php)) @
22275 A helper function to quickly add php to an @code{nginx-server-configuration}.
22278 A simple services setup for nginx with php can look like this:
22280 (services (cons* (service dhcp-client-service-type)
22281 (service php-fpm-service-type)
22282 (service nginx-service-type
22283 (nginx-server-configuration
22284 (server-name '("example.com"))
22285 (root "/srv/http/")
22287 (list (nginx-php-location)))
22289 (ssl-certificate #f)
22290 (ssl-certificate-key #f)))
22294 @cindex cat-avatar-generator
22295 The cat avatar generator is a simple service to demonstrate the use of php-fpm
22296 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
22297 the hash of a user's email address.
22299 @deffn {Scheme Procedure} cat-avatar-generator-service @
22300 [#:cache-dir "/var/cache/cat-avatar-generator"] @
22301 [#:package cat-avatar-generator] @
22302 [#:configuration (nginx-server-configuration)]
22303 Returns an nginx-server-configuration that inherits @code{configuration}. It
22304 extends the nginx configuration to add a server block that serves @code{package},
22305 a version of cat-avatar-generator. During execution, cat-avatar-generator will
22306 be able to use @code{cache-dir} as its cache directory.
22309 A simple setup for cat-avatar-generator can look like this:
22311 (services (cons* (cat-avatar-generator-service
22313 (nginx-server-configuration
22314 (server-name '("example.com"))))
22319 @subsubheading Hpcguix-web
22321 @cindex hpcguix-web
22322 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
22323 program is a customizable web interface to browse Guix packages,
22324 initially designed for users of high-performance computing (HPC)
22327 @defvr {Scheme Variable} hpcguix-web-service-type
22328 The service type for @code{hpcguix-web}.
22331 @deftp {Data Type} hpcguix-web-configuration
22332 Data type for the hpcguix-web service configuration.
22336 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
22337 configuration. The main items available in this spec are:
22340 @item @code{title-prefix} (default: @code{"hpcguix | "})
22341 The page title prefix.
22343 @item @code{guix-command} (default: @code{"guix"})
22344 The @command{guix} command.
22346 @item @code{package-filter-proc} (default: @code{(const #t)})
22347 A procedure specifying how to filter packages that are displayed.
22349 @item @code{package-page-extension-proc} (default: @code{(const '())})
22350 Extension package for @code{hpcguix-web}.
22352 @item @code{menu} (default: @code{'()})
22353 Additional entry in page @code{menu}.
22355 @item @code{channels} (default: @code{%default-channels})
22356 List of channels from which the package list is built (@pxref{Channels}).
22358 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
22359 The expiration time, in seconds, after which the package list is rebuilt from
22360 the latest instances of the given channels.
22363 See the hpcguix-web repository for a
22364 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
22367 @item @code{package} (default: @code{hpcguix-web})
22368 The hpcguix-web package to use.
22372 A typical hpcguix-web service declaration looks like this:
22375 (service hpcguix-web-service-type
22376 (hpcguix-web-configuration
22378 #~(define site-config
22379 (hpcweb-configuration
22380 (title-prefix "Guix-HPC - ")
22381 (menu '(("/about" "ABOUT"))))))))
22385 The hpcguix-web service periodically updates the package list it publishes by
22386 pulling channels from Git. To that end, it needs to access X.509 certificates
22387 so that it can authenticate Git servers when communicating over HTTPS, and it
22388 assumes that @file{/etc/ssl/certs} contains those certificates.
22390 Thus, make sure to add @code{nss-certs} or another certificate package to the
22391 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
22392 more information on X.509 certificates.
22395 @node Certificate Services
22396 @subsection Certificate Services
22399 @cindex HTTP, HTTPS
22400 @cindex Let's Encrypt
22401 @cindex TLS certificates
22402 The @code{(gnu services certbot)} module provides a service to
22403 automatically obtain a valid TLS certificate from the Let's Encrypt
22404 certificate authority. These certificates can then be used to serve
22405 content securely over HTTPS or other TLS-based protocols, with the
22406 knowledge that the client will be able to verify the server's
22409 @url{https://letsencrypt.org/, Let's Encrypt} provides the
22410 @code{certbot} tool to automate the certification process. This tool
22411 first securely generates a key on the server. It then makes a request
22412 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
22413 checks that the request originates from the host in question by using a
22414 challenge-response protocol, requiring the server to provide its
22415 response over HTTP. If that protocol completes successfully, the CA
22416 signs the key, resulting in a certificate. That certificate is valid
22417 for a limited period of time, and therefore to continue to provide TLS
22418 services, the server needs to periodically ask the CA to renew its
22421 The certbot service automates this process: the initial key
22422 generation, the initial certification request to the Let's Encrypt
22423 service, the web server challenge/response integration, writing the
22424 certificate to disk, the automated periodic renewals, and the deployment
22425 tasks associated with the renewal (e.g.@: reloading services, copying keys
22426 with different permissions).
22428 Certbot is run twice a day, at a random minute within the hour. It
22429 won't do anything until your certificates are due for renewal or
22430 revoked, but running it regularly would give your service a chance of
22431 staying online in case a Let's Encrypt-initiated revocation happened for
22434 By using this service, you agree to the ACME Subscriber Agreement, which
22435 can be found there:
22436 @url{https://acme-v01.api.letsencrypt.org/directory}.
22438 @defvr {Scheme Variable} certbot-service-type
22439 A service type for the @code{certbot} Let's Encrypt client. Its value
22440 must be a @code{certbot-configuration} record as in this example:
22443 (define %nginx-deploy-hook
22445 "nginx-deploy-hook"
22446 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
22447 (kill pid SIGHUP))))
22449 (service certbot-service-type
22450 (certbot-configuration
22451 (email "foo@@example.net")
22454 (certificate-configuration
22455 (domains '("example.net" "www.example.net"))
22456 (deploy-hook %nginx-deploy-hook))
22457 (certificate-configuration
22458 (domains '("bar.example.net")))))))
22461 See below for details about @code{certbot-configuration}.
22464 @deftp {Data Type} certbot-configuration
22465 Data type representing the configuration of the @code{certbot} service.
22466 This type has the following parameters:
22469 @item @code{package} (default: @code{certbot})
22470 The certbot package to use.
22472 @item @code{webroot} (default: @code{/var/www})
22473 The directory from which to serve the Let's Encrypt challenge/response
22476 @item @code{certificates} (default: @code{()})
22477 A list of @code{certificates-configuration}s for which to generate
22478 certificates and request signatures. Each certificate has a @code{name}
22479 and several @code{domains}.
22481 @item @code{email} (default: @code{#f})
22482 Optional email address used for registration and recovery contact.
22483 Setting this is encouraged as it allows you to receive important
22484 notifications about the account and issued certificates.
22486 @item @code{server} (default: @code{#f})
22487 Optional URL of ACME server. Setting this overrides certbot's default,
22488 which is the Let's Encrypt server.
22490 @item @code{rsa-key-size} (default: @code{2048})
22491 Size of the RSA key.
22493 @item @code{default-location} (default: @i{see below})
22494 The default @code{nginx-location-configuration}. Because @code{certbot}
22495 needs to be able to serve challenges and responses, it needs to be able
22496 to run a web server. It does so by extending the @code{nginx} web
22497 service with an @code{nginx-server-configuration} listening on the
22498 @var{domains} on port 80, and which has a
22499 @code{nginx-location-configuration} for the @code{/.well-known/} URI
22500 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
22501 these nginx configuration data types.
22503 Requests to other URL paths will be matched by the
22504 @code{default-location}, which if present is added to all
22505 @code{nginx-server-configuration}s.
22507 By default, the @code{default-location} will issue a redirect from
22508 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
22509 you to define what to serve on your site via @code{https}.
22511 Pass @code{#f} to not issue a default location.
22515 @deftp {Data Type} certificate-configuration
22516 Data type representing the configuration of a certificate.
22517 This type has the following parameters:
22520 @item @code{name} (default: @i{see below})
22521 This name is used by Certbot for housekeeping and in file paths; it
22522 doesn't affect the content of the certificate itself. To see
22523 certificate names, run @code{certbot certificates}.
22525 Its default is the first provided domain.
22527 @item @code{domains} (default: @code{()})
22528 The first domain provided will be the subject CN of the certificate, and
22529 all domains will be Subject Alternative Names on the certificate.
22531 @item @code{challenge} (default: @code{#f})
22532 The challenge type that has to be run by certbot. If @code{#f} is specified,
22533 default to the HTTP challenge. If a value is specified, defaults to the
22534 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
22535 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
22536 and gives Let's Encrypt permission to log the public IP address of the
22537 requesting machine.
22539 @item @code{authentication-hook} (default: @code{#f})
22540 Command to be run in a shell once for each certificate challenge to be
22541 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
22542 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
22543 contains the validation string and @code{$CERTBOT_TOKEN} contains the
22544 file name of the resource requested when performing an HTTP-01 challenge.
22546 @item @code{cleanup-hook} (default: @code{#f})
22547 Command to be run in a shell once for each certificate challenge that
22548 have been answered by the @code{auth-hook}. For this command, the shell
22549 variables available in the @code{auth-hook} script are still available, and
22550 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
22551 of the @code{auth-hook} script.
22553 @item @code{deploy-hook} (default: @code{#f})
22554 Command to be run in a shell once for each successfully issued
22555 certificate. For this command, the shell variable
22556 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
22557 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
22558 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
22559 contain a space-delimited list of renewed certificate domains (for
22560 example, @samp{"example.com www.example.com"}.
22565 For each @code{certificate-configuration}, the certificate is saved to
22566 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
22567 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
22569 @subsection DNS Services
22570 @cindex DNS (domain name system)
22571 @cindex domain name system (DNS)
22573 The @code{(gnu services dns)} module provides services related to the
22574 @dfn{domain name system} (DNS). It provides a server service for hosting
22575 an @emph{authoritative} DNS server for multiple zones, slave or master.
22576 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
22577 caching and forwarding DNS server for the LAN, which uses
22578 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
22580 @subsubheading Knot Service
22582 An example configuration of an authoritative server for two zones, one master
22586 (define-zone-entries example.org.zone
22587 ;; Name TTL Class Type Data
22588 ("@@" "" "IN" "A" "127.0.0.1")
22589 ("@@" "" "IN" "NS" "ns")
22590 ("ns" "" "IN" "A" "127.0.0.1"))
22592 (define master-zone
22593 (knot-zone-configuration
22594 (domain "example.org")
22596 (origin "example.org")
22597 (entries example.org.zone)))))
22600 (knot-zone-configuration
22601 (domain "plop.org")
22602 (dnssec-policy "default")
22603 (master (list "plop-master"))))
22605 (define plop-master
22606 (knot-remote-configuration
22608 (address (list "208.76.58.171"))))
22612 (services (cons* (service knot-service-type
22613 (knot-configuration
22614 (remotes (list plop-master))
22615 (zones (list master-zone slave-zone))))
22620 @deffn {Scheme Variable} knot-service-type
22621 This is the type for the Knot DNS server.
22623 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
22624 zones, that is to say domain names you would buy from a registrar. This server
22625 is not a resolver, meaning that it can only resolve names for which it is
22626 authoritative. This server can be configured to serve zones as a master server
22627 or a slave server as a per-zone basis. Slave zones will get their data from
22628 masters, and will serve it as an authoritative server. From the point of view
22629 of a resolver, there is no difference between master and slave.
22631 The following data types are used to configure the Knot DNS server:
22634 @deftp {Data Type} knot-key-configuration
22635 Data type representing a key.
22636 This type has the following parameters:
22639 @item @code{id} (default: @code{""})
22640 An identifier for other configuration fields to refer to this key. IDs must
22641 be unique and must not be empty.
22643 @item @code{algorithm} (default: @code{#f})
22644 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
22645 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
22646 and @code{'hmac-sha512}.
22648 @item @code{secret} (default: @code{""})
22649 The secret key itself.
22654 @deftp {Data Type} knot-acl-configuration
22655 Data type representing an Access Control List (ACL) configuration.
22656 This type has the following parameters:
22659 @item @code{id} (default: @code{""})
22660 An identifier for ether configuration fields to refer to this key. IDs must be
22661 unique and must not be empty.
22663 @item @code{address} (default: @code{'()})
22664 An ordered list of IP addresses, network subnets, or network ranges represented
22665 with strings. The query must match one of them. Empty value means that
22666 address match is not required.
22668 @item @code{key} (default: @code{'()})
22669 An ordered list of references to keys represented with strings. The string
22670 must match a key ID defined in a @code{knot-key-configuration}. No key means
22671 that a key is not require to match that ACL.
22673 @item @code{action} (default: @code{'()})
22674 An ordered list of actions that are permitted or forbidden by this ACL. Possible
22675 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
22676 and @code{'update}.
22678 @item @code{deny?} (default: @code{#f})
22679 When true, the ACL defines restrictions. Listed actions are forbidden. When
22680 false, listed actions are allowed.
22685 @deftp {Data Type} zone-entry
22686 Data type representing a record entry in a zone file.
22687 This type has the following parameters:
22690 @item @code{name} (default: @code{"@@"})
22691 The name of the record. @code{"@@"} refers to the origin of the zone. Names
22692 are relative to the origin of the zone. For example, in the @code{example.org}
22693 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
22694 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
22695 refers to @code{ns.example.org}.
22697 @item @code{ttl} (default: @code{""})
22698 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
22700 @item @code{class} (default: @code{"IN"})
22701 The class of the record. Knot currently supports only @code{"IN"} and
22702 partially @code{"CH"}.
22704 @item @code{type} (default: @code{"A"})
22705 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
22706 address), NS (Name Server) and MX (Mail eXchange). Many other types are
22709 @item @code{data} (default: @code{""})
22710 The data contained in the record. For instance an IP address associated with
22711 an A record, or a domain name associated with an NS record. Remember that
22712 domain names are relative to the origin unless they end with a dot.
22717 @deftp {Data Type} zone-file
22718 Data type representing the content of a zone file.
22719 This type has the following parameters:
22722 @item @code{entries} (default: @code{'()})
22723 The list of entries. The SOA record is taken care of, so you don't need to
22724 put it in the list of entries. This list should probably contain an entry
22725 for your primary authoritative DNS server. Other than using a list of entries
22726 directly, you can use @code{define-zone-entries} to define a object containing
22727 the list of entries more easily, that you can later pass to the @code{entries}
22728 field of the @code{zone-file}.
22730 @item @code{origin} (default: @code{""})
22731 The name of your zone. This parameter cannot be empty.
22733 @item @code{ns} (default: @code{"ns"})
22734 The domain of your primary authoritative DNS server. The name is relative to
22735 the origin, unless it ends with a dot. It is mandatory that this primary
22736 DNS server corresponds to an NS record in the zone and that it is associated
22737 to an IP address in the list of entries.
22739 @item @code{mail} (default: @code{"hostmaster"})
22740 An email address people can contact you at, as the owner of the zone. This
22741 is translated as @code{<mail>@@<origin>}.
22743 @item @code{serial} (default: @code{1})
22744 The serial number of the zone. As this is used to keep track of changes by
22745 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
22746 Always increment it when you make a change in your zone.
22748 @item @code{refresh} (default: @code{(* 2 24 3600)})
22749 The frequency at which slaves will do a zone transfer. This value is a number
22750 of seconds. It can be computed by multiplications or with
22751 @code{(string->duration)}.
22753 @item @code{retry} (default: @code{(* 15 60)})
22754 The period after which a slave will retry to contact its master when it fails
22755 to do so a first time.
22757 @item @code{expiry} (default: @code{(* 14 24 3600)})
22758 Default TTL of records. Existing records are considered correct for at most
22759 this amount of time. After this period, resolvers will invalidate their cache
22760 and check again that it still exists.
22762 @item @code{nx} (default: @code{3600})
22763 Default TTL of inexistant records. This delay is usually short because you want
22764 your new domains to reach everyone quickly.
22769 @deftp {Data Type} knot-remote-configuration
22770 Data type representing a remote configuration.
22771 This type has the following parameters:
22774 @item @code{id} (default: @code{""})
22775 An identifier for other configuration fields to refer to this remote. IDs must
22776 be unique and must not be empty.
22778 @item @code{address} (default: @code{'()})
22779 An ordered list of destination IP addresses. Addresses are tried in sequence.
22780 An optional port can be given with the @@ separator. For instance:
22781 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
22783 @item @code{via} (default: @code{'()})
22784 An ordered list of source IP addresses. An empty list will have Knot choose
22785 an appropriate source IP. An optional port can be given with the @@ separator.
22786 The default is to choose at random.
22788 @item @code{key} (default: @code{#f})
22789 A reference to a key, that is a string containing the identifier of a key
22790 defined in a @code{knot-key-configuration} field.
22795 @deftp {Data Type} knot-keystore-configuration
22796 Data type representing a keystore to hold dnssec keys.
22797 This type has the following parameters:
22800 @item @code{id} (default: @code{""})
22801 The id of the keystore. It must not be empty.
22803 @item @code{backend} (default: @code{'pem})
22804 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
22806 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
22807 The configuration string of the backend. An example for the PKCS#11 is:
22808 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
22809 For the pem backend, the string represents a path in the file system.
22814 @deftp {Data Type} knot-policy-configuration
22815 Data type representing a dnssec policy. Knot DNS is able to automatically
22816 sign your zones. It can either generate and manage your keys automatically or
22817 use keys that you generate.
22819 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
22820 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
22821 zone. In order to be trusted, the KSK needs to be present in the parent zone
22822 (usually a top-level domain). If your registrar supports dnssec, you will
22823 have to send them your KSK's hash so they can add a DS record in their zone.
22824 This is not automated and need to be done each time you change your KSK.
22826 The policy also defines the lifetime of keys. Usually, ZSK can be changed
22827 easily and use weaker cryptographic functions (they use lower parameters) in
22828 order to sign records quickly, so they are changed often. The KSK however
22829 requires manual interaction with the registrar, so they are changed less often
22830 and use stronger parameters because they sign only one record.
22832 This type has the following parameters:
22835 @item @code{id} (default: @code{""})
22836 The id of the policy. It must not be empty.
22838 @item @code{keystore} (default: @code{"default"})
22839 A reference to a keystore, that is a string containing the identifier of a
22840 keystore defined in a @code{knot-keystore-configuration} field. The
22841 @code{"default"} identifier means the default keystore (a kasp database that
22842 was setup by this service).
22844 @item @code{manual?} (default: @code{#f})
22845 Whether the key management is manual or automatic.
22847 @item @code{single-type-signing?} (default: @code{#f})
22848 When @code{#t}, use the Single-Type Signing Scheme.
22850 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
22851 An algorithm of signing keys and issued signatures.
22853 @item @code{ksk-size} (default: @code{256})
22854 The length of the KSK. Note that this value is correct for the default
22855 algorithm, but would be unsecure for other algorithms.
22857 @item @code{zsk-size} (default: @code{256})
22858 The length of the ZSK. Note that this value is correct for the default
22859 algorithm, but would be unsecure for other algorithms.
22861 @item @code{dnskey-ttl} (default: @code{'default})
22862 The TTL value for DNSKEY records added into zone apex. The special
22863 @code{'default} value means same as the zone SOA TTL.
22865 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
22866 The period between ZSK publication and the next rollover initiation.
22868 @item @code{propagation-delay} (default: @code{(* 24 3600)})
22869 An extra delay added for each key rollover step. This value should be high
22870 enough to cover propagation of data from the master server to all slaves.
22872 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
22873 A validity period of newly issued signatures.
22875 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
22876 A period how long before a signature expiration the signature will be refreshed.
22878 @item @code{nsec3?} (default: @code{#f})
22879 When @code{#t}, NSEC3 will be used instead of NSEC.
22881 @item @code{nsec3-iterations} (default: @code{5})
22882 The number of additional times the hashing is performed.
22884 @item @code{nsec3-salt-length} (default: @code{8})
22885 The length of a salt field in octets, which is appended to the original owner
22886 name before hashing.
22888 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
22889 The validity period of newly issued salt field.
22894 @deftp {Data Type} knot-zone-configuration
22895 Data type representing a zone served by Knot.
22896 This type has the following parameters:
22899 @item @code{domain} (default: @code{""})
22900 The domain served by this configuration. It must not be empty.
22902 @item @code{file} (default: @code{""})
22903 The file where this zone is saved. This parameter is ignored by master zones.
22904 Empty means default location that depends on the domain name.
22906 @item @code{zone} (default: @code{(zone-file)})
22907 The content of the zone file. This parameter is ignored by slave zones. It
22908 must contain a zone-file record.
22910 @item @code{master} (default: @code{'()})
22911 A list of master remotes. When empty, this zone is a master. When set, this
22912 zone is a slave. This is a list of remotes identifiers.
22914 @item @code{ddns-master} (default: @code{#f})
22915 The main master. When empty, it defaults to the first master in the list of
22918 @item @code{notify} (default: @code{'()})
22919 A list of slave remote identifiers.
22921 @item @code{acl} (default: @code{'()})
22922 A list of acl identifiers.
22924 @item @code{semantic-checks?} (default: @code{#f})
22925 When set, this adds more semantic checks to the zone.
22927 @item @code{disable-any?} (default: @code{#f})
22928 When set, this forbids queries of the ANY type.
22930 @item @code{zonefile-sync} (default: @code{0})
22931 The delay between a modification in memory and on disk. 0 means immediate
22934 @item @code{zonefile-load} (default: @code{#f})
22935 The way the zone file contents are applied during zone load. Possible values
22939 @item @code{#f} for using the default value from Knot,
22940 @item @code{'none} for not using the zone file at all,
22941 @item @code{'difference} for computing the difference between already available
22942 contents and zone contents and applying it to the current zone contents,
22943 @item @code{'difference-no-serial} for the same as @code{'difference}, but
22944 ignoring the SOA serial in the zone file, while the server takes care of it
22946 @item @code{'whole} for loading zone contents from the zone file.
22949 @item @code{journal-content} (default: @code{#f})
22950 The way the journal is used to store zone and its changes. Possible values
22951 are @code{'none} to not use it at all, @code{'changes} to store changes and
22952 @code{'all} to store contents. @code{#f} does not set this option, so the
22953 default value from Knot is used.
22955 @item @code{max-journal-usage} (default: @code{#f})
22956 The maximum size for the journal on disk. @code{#f} does not set this option,
22957 so the default value from Knot is used.
22959 @item @code{max-journal-depth} (default: @code{#f})
22960 The maximum size of the history. @code{#f} does not set this option, so the
22961 default value from Knot is used.
22963 @item @code{max-zone-size} (default: @code{#f})
22964 The maximum size of the zone file. This limit is enforced for incoming
22965 transfer and updates. @code{#f} does not set this option, so the default
22966 value from Knot is used.
22968 @item @code{dnssec-policy} (default: @code{#f})
22969 A reference to a @code{knot-policy-configuration} record, or the special
22970 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
22973 @item @code{serial-policy} (default: @code{'increment})
22974 A policy between @code{'increment} and @code{'unixtime}.
22979 @deftp {Data Type} knot-configuration
22980 Data type representing the Knot configuration.
22981 This type has the following parameters:
22984 @item @code{knot} (default: @code{knot})
22987 @item @code{run-directory} (default: @code{"/var/run/knot"})
22988 The run directory. This directory will be used for pid file and sockets.
22990 @item @code{includes} (default: @code{'()})
22991 A list of strings or file-like objects denoting other files that must be
22992 included at the top of the configuration file.
22994 @cindex secrets, Knot service
22995 This can be used to manage secrets out-of-band. For example, secret
22996 keys may be stored in an out-of-band file not managed by Guix, and
22997 thus not visible in @file{/gnu/store}---e.g., you could store secret
22998 key configuration in @file{/etc/knot/secrets.conf} and add this file
22999 to the @code{includes} list.
23001 One can generate a secret tsig key (for nsupdate and zone transfers with the
23002 keymgr command from the knot package. Note that the package is not automatically
23003 installed by the service. The following example shows how to generate a new
23007 keymgr -t mysecret > /etc/knot/secrets.conf
23008 chmod 600 /etc/knot/secrets.conf
23011 Also note that the generated key will be named @var{mysecret}, so it is the
23012 name that needs to be used in the @var{key} field of the
23013 @code{knot-acl-configuration} record and in other places that need to refer
23016 It can also be used to add configuration not supported by this interface.
23018 @item @code{listen-v4} (default: @code{"0.0.0.0"})
23019 An ip address on which to listen.
23021 @item @code{listen-v6} (default: @code{"::"})
23022 An ip address on which to listen.
23024 @item @code{listen-port} (default: @code{53})
23025 A port on which to listen.
23027 @item @code{keys} (default: @code{'()})
23028 The list of knot-key-configuration used by this configuration.
23030 @item @code{acls} (default: @code{'()})
23031 The list of knot-acl-configuration used by this configuration.
23033 @item @code{remotes} (default: @code{'()})
23034 The list of knot-remote-configuration used by this configuration.
23036 @item @code{zones} (default: @code{'()})
23037 The list of knot-zone-configuration used by this configuration.
23042 @subsubheading Knot Resolver Service
23044 @deffn {Scheme Variable} knot-resolver-service-type
23045 This this the type of the knot resolver service, whose value should be
23046 an @code{knot-resolver-configuration} object as in this example:
23049 (service knot-resolver-service-type
23050 (knot-resolver-configuration
23051 (kresd-config-file (plain-file "kresd.conf" "
23052 net.listen('192.168.0.1', 5353)
23053 user('knot-resolver', 'knot-resolver')
23054 modules = @{ 'hints > iterate', 'stats', 'predict' @}
23055 cache.size = 100 * MB
23059 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
23062 @deftp {Data Type} knot-resolver-configuration
23063 Data type representing the configuration of knot-resolver.
23066 @item @code{package} (default: @var{knot-resolver})
23067 Package object of the knot DNS resolver.
23069 @item @code{kresd-config-file} (default: %kresd.conf)
23070 File-like object of the kresd configuration file to use, by default it
23071 will listen on @code{127.0.0.1} and @code{::1}.
23073 @item @code{garbage-collection-interval} (default: 1000)
23074 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
23080 @subsubheading Dnsmasq Service
23082 @deffn {Scheme Variable} dnsmasq-service-type
23083 This is the type of the dnsmasq service, whose value should be an
23084 @code{dnsmasq-configuration} object as in this example:
23087 (service dnsmasq-service-type
23088 (dnsmasq-configuration
23090 (servers '("192.168.1.1"))))
23094 @deftp {Data Type} dnsmasq-configuration
23095 Data type representing the configuration of dnsmasq.
23098 @item @code{package} (default: @var{dnsmasq})
23099 Package object of the dnsmasq server.
23101 @item @code{no-hosts?} (default: @code{#f})
23102 When true, don't read the hostnames in /etc/hosts.
23104 @item @code{port} (default: @code{53})
23105 The port to listen on. Setting this to zero completely disables DNS
23106 responses, leaving only DHCP and/or TFTP functions.
23108 @item @code{local-service?} (default: @code{#t})
23109 Accept DNS queries only from hosts whose address is on a local subnet,
23110 ie a subnet for which an interface exists on the server.
23112 @item @code{listen-addresses} (default: @code{'()})
23113 Listen on the given IP addresses.
23115 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
23116 The file to read the IP address of the upstream nameservers from.
23118 @item @code{no-resolv?} (default: @code{#f})
23119 When true, don't read @var{resolv-file}.
23121 @item @code{servers} (default: @code{'()})
23122 Specify IP address of upstream servers directly.
23124 @item @code{addresses} (default: @code{'()})
23125 For each entry, specify an IP address to return for any host in the
23126 given domains. Queries in the domains are never forwarded and always
23127 replied to with the specified IP address.
23129 This is useful for redirecting hosts locally, for example:
23132 (service dnsmasq-service-type
23133 (dnsmasq-configuration
23135 '(; Redirect to a local web-server.
23136 "/example.org/127.0.0.1"
23137 ; Redirect subdomain to a specific IP.
23138 "/subdomain.example.org/192.168.1.42"))))
23141 Note that rules in @file{/etc/hosts} take precedence over this.
23143 @item @code{cache-size} (default: @code{150})
23144 Set the size of dnsmasq's cache. Setting the cache size to zero
23147 @item @code{negative-cache?} (default: @code{#t})
23148 When false, disable negative caching.
23153 @subsubheading ddclient Service
23156 The ddclient service described below runs the ddclient daemon, which takes
23157 care of automatically updating DNS entries for service providers such as
23158 @uref{https://dyn.com/dns/, Dyn}.
23160 The following example show instantiates the service with its default
23164 (service ddclient-service-type)
23167 Note that ddclient needs to access credentials that are stored in a
23168 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
23169 @code{secret-file} below). You are expected to create this file manually, in
23170 an ``out-of-band'' fashion (you @emph{could} make this file part of the
23171 service configuration, for instance by using @code{plain-file}, but it will be
23172 world-readable @i{via} @file{/gnu/store}). See the examples in the
23173 @file{share/ddclient} directory of the @code{ddclient} package.
23175 @c %start of fragment
23177 Available @code{ddclient-configuration} fields are:
23179 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
23180 The ddclient package.
23184 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
23185 The period after which ddclient will retry to check IP and domain name.
23187 Defaults to @samp{300}.
23191 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
23192 Use syslog for the output.
23194 Defaults to @samp{#t}.
23198 @deftypevr {@code{ddclient-configuration} parameter} string mail
23201 Defaults to @samp{"root"}.
23205 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
23206 Mail failed update to user.
23208 Defaults to @samp{"root"}.
23212 @deftypevr {@code{ddclient-configuration} parameter} string pid
23213 The ddclient PID file.
23215 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
23219 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
23220 Enable SSL support.
23222 Defaults to @samp{#t}.
23226 @deftypevr {@code{ddclient-configuration} parameter} string user
23227 Specifies the user name or ID that is used when running ddclient
23230 Defaults to @samp{"ddclient"}.
23234 @deftypevr {@code{ddclient-configuration} parameter} string group
23235 Group of the user who will run the ddclient program.
23237 Defaults to @samp{"ddclient"}.
23241 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
23242 Secret file which will be appended to @file{ddclient.conf} file. This
23243 file contains credentials for use by ddclient. You are expected to
23244 create it manually.
23246 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
23250 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
23251 Extra options will be appended to @file{ddclient.conf} file.
23253 Defaults to @samp{()}.
23258 @c %end of fragment
23262 @subsection VPN Services
23263 @cindex VPN (virtual private network)
23264 @cindex virtual private network (VPN)
23266 The @code{(gnu services vpn)} module provides services related to
23267 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
23268 your machine to connect to a VPN, and a @emph{server} service for your machine
23269 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
23271 @deffn {Scheme Procedure} openvpn-client-service @
23272 [#:config (openvpn-client-configuration)]
23274 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
23277 @deffn {Scheme Procedure} openvpn-server-service @
23278 [#:config (openvpn-server-configuration)]
23280 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
23282 Both can be run simultaneously.
23285 @c %automatically generated documentation
23287 Available @code{openvpn-client-configuration} fields are:
23289 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
23290 The OpenVPN package.
23294 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
23295 The OpenVPN pid file.
23297 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
23301 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
23302 The protocol (UDP or TCP) used to open a channel between clients and
23305 Defaults to @samp{udp}.
23309 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
23310 The device type used to represent the VPN connection.
23312 Defaults to @samp{tun}.
23316 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
23317 The certificate authority to check connections against.
23319 Defaults to @samp{"/etc/openvpn/ca.crt"}.
23323 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
23324 The certificate of the machine the daemon is running on. It should be
23325 signed by the authority given in @code{ca}.
23327 Defaults to @samp{"/etc/openvpn/client.crt"}.
23331 @deftypevr {@code{openvpn-client-configuration} parameter} string key
23332 The key of the machine the daemon is running on. It must be the key whose
23333 certificate is @code{cert}.
23335 Defaults to @samp{"/etc/openvpn/client.key"}.
23339 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
23340 Whether to use the lzo compression algorithm.
23342 Defaults to @samp{#t}.
23346 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
23347 Don't re-read key files across SIGUSR1 or --ping-restart.
23349 Defaults to @samp{#t}.
23353 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
23354 Don't close and reopen TUN/TAP device or run up/down scripts across
23355 SIGUSR1 or --ping-restart restarts.
23357 Defaults to @samp{#t}.
23361 @deftypevr {@code{openvpn-client-configuration} parameter} boolean fast-io?
23362 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
23363 poll/epoll/select prior to the write operation.
23365 Defaults to @samp{#f}.
23368 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
23371 Defaults to @samp{3}.
23375 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
23376 Add an additional layer of HMAC authentication on top of the TLS control
23377 channel to protect against DoS attacks.
23379 Defaults to @samp{#f}.
23383 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string auth-user-pass
23384 Authenticate with server using username/password. The option is a file
23385 containing username/password on 2 lines. Do not use a file-like object as it
23386 would be added to the store and readable by any user.
23388 Defaults to @samp{'disabled}.
23391 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
23392 Whether to check the server certificate has server usage extension.
23394 Defaults to @samp{#t}.
23398 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
23399 Bind to a specific local port number.
23401 Defaults to @samp{#f}.
23405 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
23406 Retry resolving server address.
23408 Defaults to @samp{#t}.
23412 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
23413 A list of remote servers to connect to.
23415 Defaults to @samp{()}.
23417 Available @code{openvpn-remote-configuration} fields are:
23419 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
23422 Defaults to @samp{"my-server"}.
23426 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
23427 Port number the server listens to.
23429 Defaults to @samp{1194}.
23434 @c %end of automatic openvpn-client documentation
23436 @c %automatically generated documentation
23438 Available @code{openvpn-server-configuration} fields are:
23440 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
23441 The OpenVPN package.
23445 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
23446 The OpenVPN pid file.
23448 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
23452 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
23453 The protocol (UDP or TCP) used to open a channel between clients and
23456 Defaults to @samp{udp}.
23460 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
23461 The device type used to represent the VPN connection.
23463 Defaults to @samp{tun}.
23467 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
23468 The certificate authority to check connections against.
23470 Defaults to @samp{"/etc/openvpn/ca.crt"}.
23474 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
23475 The certificate of the machine the daemon is running on. It should be
23476 signed by the authority given in @code{ca}.
23478 Defaults to @samp{"/etc/openvpn/client.crt"}.
23482 @deftypevr {@code{openvpn-server-configuration} parameter} string key
23483 The key of the machine the daemon is running on. It must be the key whose
23484 certificate is @code{cert}.
23486 Defaults to @samp{"/etc/openvpn/client.key"}.
23490 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
23491 Whether to use the lzo compression algorithm.
23493 Defaults to @samp{#t}.
23497 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
23498 Don't re-read key files across SIGUSR1 or --ping-restart.
23500 Defaults to @samp{#t}.
23504 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
23505 Don't close and reopen TUN/TAP device or run up/down scripts across
23506 SIGUSR1 or --ping-restart restarts.
23508 Defaults to @samp{#t}.
23512 @deftypevr {@code{openvpn-server-configuration} parameter} boolean fast-io?
23513 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
23514 poll/epoll/select prior to the write operation.
23516 Defaults to @samp{#f}.
23519 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
23522 Defaults to @samp{3}.
23526 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
23527 Add an additional layer of HMAC authentication on top of the TLS control
23528 channel to protect against DoS attacks.
23530 Defaults to @samp{#f}.
23534 @deftypevr {@code{openvpn-server-configuration} parameter} number port
23535 Specifies the port number on which the server listens.
23537 Defaults to @samp{1194}.
23541 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
23542 An ip and mask specifying the subnet inside the virtual network.
23544 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
23548 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
23549 A CIDR notation specifying the IPv6 subnet inside the virtual network.
23551 Defaults to @samp{#f}.
23555 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
23556 The Diffie-Hellman parameters file.
23558 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
23562 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
23563 The file that records client IPs.
23565 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
23569 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
23570 When true, the server will act as a gateway for its clients.
23572 Defaults to @samp{#f}.
23576 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
23577 When true, clients are allowed to talk to each other inside the VPN.
23579 Defaults to @samp{#f}.
23583 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
23584 Causes ping-like messages to be sent back and forth over the link so
23585 that each side knows when the other side has gone down. @code{keepalive}
23586 requires a pair. The first element is the period of the ping sending,
23587 and the second element is the timeout before considering the other side
23592 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
23593 The maximum number of clients.
23595 Defaults to @samp{100}.
23599 @deftypevr {@code{openvpn-server-configuration} parameter} string status
23600 The status file. This file shows a small report on current connection.
23601 It is truncated and rewritten every minute.
23603 Defaults to @samp{"/var/run/openvpn/status"}.
23607 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
23608 The list of configuration for some clients.
23610 Defaults to @samp{()}.
23612 Available @code{openvpn-ccd-configuration} fields are:
23614 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
23617 Defaults to @samp{"client"}.
23621 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
23624 Defaults to @samp{#f}.
23628 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
23631 Defaults to @samp{#f}.
23638 @c %end of automatic openvpn-server documentation
23641 @node Network File System
23642 @subsection Network File System
23645 The @code{(gnu services nfs)} module provides the following services,
23646 which are most commonly used in relation to mounting or exporting
23647 directory trees as @dfn{network file systems} (NFS).
23649 While it is possible to use the individual components that together make
23650 up a Network File System service, we recommended to configure an NFS
23651 server with the @code{nfs-service-type}.
23653 @subsubheading NFS Service
23654 @cindex NFS, server
23656 The NFS service takes care of setting up all NFS component services,
23657 kernel configuration file systems, and installs configuration files in
23658 the locations that NFS expects.
23660 @defvr {Scheme Variable} nfs-service-type
23661 A service type for a complete NFS server.
23664 @deftp {Data Type} nfs-configuration
23665 This data type represents the configuration of the NFS service and all
23668 It has the following parameters:
23670 @item @code{nfs-utils} (default: @code{nfs-utils})
23671 The nfs-utils package to use.
23673 @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
23674 If a list of string values is provided, the @command{rpc.nfsd} daemon
23675 will be limited to supporting the given versions of the NFS protocol.
23677 @item @code{exports} (default: @code{'()})
23678 This is a list of directories the NFS server should export. Each entry
23679 is a list consisting of two elements: a directory name and a string
23680 containing all options. This is an example in which the directory
23681 @file{/export} is served to all NFS clients as a read-only share:
23687 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
23690 @item @code{rpcmountd-port} (default: @code{#f})
23691 The network port that the @command{rpc.mountd} daemon should use.
23693 @item @code{rpcstatd-port} (default: @code{#f})
23694 The network port that the @command{rpc.statd} daemon should use.
23696 @item @code{rpcbind} (default: @code{rpcbind})
23697 The rpcbind package to use.
23699 @item @code{idmap-domain} (default: @code{"localdomain"})
23700 The local NFSv4 domain name.
23702 @item @code{nfsd-port} (default: @code{2049})
23703 The network port that the @command{nfsd} daemon should use.
23705 @item @code{nfsd-threads} (default: @code{8})
23706 The number of threads used by the @command{nfsd} daemon.
23708 @item @code{nfsd-tcp?} (default: @code{#t})
23709 Whether the @command{nfsd} daemon should listen on a TCP socket.
23711 @item @code{nfsd-udp?} (default: @code{#f})
23712 Whether the @command{nfsd} daemon should listen on a UDP socket.
23714 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23715 The directory where the pipefs file system is mounted.
23717 @item @code{debug} (default: @code{'()"})
23718 A list of subsystems for which debugging output should be enabled. This
23719 is a list of symbols. Any of these symbols are valid: @code{nfsd},
23720 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
23724 If you don't need a complete NFS service or prefer to build it yourself
23725 you can use the individual component services that are documented below.
23727 @subsubheading RPC Bind Service
23730 The RPC Bind service provides a facility to map program numbers into
23731 universal addresses.
23732 Many NFS related services use this facility. Hence it is automatically
23733 started when a dependent service starts.
23735 @defvr {Scheme Variable} rpcbind-service-type
23736 A service type for the RPC portmapper daemon.
23740 @deftp {Data Type} rpcbind-configuration
23741 Data type representing the configuration of the RPC Bind Service.
23742 This type has the following parameters:
23744 @item @code{rpcbind} (default: @code{rpcbind})
23745 The rpcbind package to use.
23747 @item @code{warm-start?} (default: @code{#t})
23748 If this parameter is @code{#t}, then the daemon will read a
23749 state file on startup thus reloading state information saved by a previous
23755 @subsubheading Pipefs Pseudo File System
23759 The pipefs file system is used to transfer NFS related data
23760 between the kernel and user space programs.
23762 @defvr {Scheme Variable} pipefs-service-type
23763 A service type for the pipefs pseudo file system.
23766 @deftp {Data Type} pipefs-configuration
23767 Data type representing the configuration of the pipefs pseudo file system service.
23768 This type has the following parameters:
23770 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23771 The directory to which the file system is to be attached.
23776 @subsubheading GSS Daemon Service
23779 @cindex global security system
23781 The @dfn{global security system} (GSS) daemon provides strong security for RPC
23783 Before exchanging RPC requests an RPC client must establish a security
23784 context. Typically this is done using the Kerberos command @command{kinit}
23785 or automatically at login time using PAM services (@pxref{Kerberos Services}).
23787 @defvr {Scheme Variable} gss-service-type
23788 A service type for the Global Security System (GSS) daemon.
23791 @deftp {Data Type} gss-configuration
23792 Data type representing the configuration of the GSS daemon service.
23793 This type has the following parameters:
23795 @item @code{nfs-utils} (default: @code{nfs-utils})
23796 The package in which the @command{rpc.gssd} command is to be found.
23798 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23799 The directory where the pipefs file system is mounted.
23805 @subsubheading IDMAP Daemon Service
23807 @cindex name mapper
23809 The idmap daemon service provides mapping between user IDs and user names.
23810 Typically it is required in order to access file systems mounted via NFSv4.
23812 @defvr {Scheme Variable} idmap-service-type
23813 A service type for the Identity Mapper (IDMAP) daemon.
23816 @deftp {Data Type} idmap-configuration
23817 Data type representing the configuration of the IDMAP daemon service.
23818 This type has the following parameters:
23820 @item @code{nfs-utils} (default: @code{nfs-utils})
23821 The package in which the @command{rpc.idmapd} command is to be found.
23823 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23824 The directory where the pipefs file system is mounted.
23826 @item @code{domain} (default: @code{#f})
23827 The local NFSv4 domain name.
23828 This must be a string or @code{#f}.
23829 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
23831 @item @code{verbosity} (default: @code{0})
23832 The verbosity level of the daemon.
23837 @node Continuous Integration
23838 @subsection Continuous Integration
23840 @cindex continuous integration
23841 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
23842 continuous integration tool for Guix. It can be used both for development and
23843 for providing substitutes to others (@pxref{Substitutes}).
23845 The @code{(gnu services cuirass)} module provides the following service.
23847 @defvr {Scheme Procedure} cuirass-service-type
23848 The type of the Cuirass service. Its value must be a
23849 @code{cuirass-configuration} object, as described below.
23852 To add build jobs, you have to set the @code{specifications} field of the
23853 configuration. Here is an example of a service that polls the Guix repository
23854 and builds the packages from a manifest. Some of the packages are defined in
23855 the @code{"custom-packages"} input, which is the equivalent of
23856 @env{GUIX_PACKAGE_PATH}.
23859 (define %cuirass-specs
23861 '((#:name . "my-manifest")
23862 (#:load-path-inputs . ("guix"))
23863 (#:package-path-inputs . ("custom-packages"))
23864 (#:proc-input . "guix")
23865 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
23866 (#:proc . cuirass-jobs)
23867 (#:proc-args . ((subset . "manifests")
23868 (systems . ("x86_64-linux"))
23869 (manifests . (("config" . "guix/manifest.scm")))))
23870 (#:inputs . (((#:name . "guix")
23871 (#:url . "git://git.savannah.gnu.org/guix.git")
23872 (#:load-path . ".")
23873 (#:branch . "master")
23874 (#:no-compile? . #t))
23875 ((#:name . "config")
23876 (#:url . "https://git.example.org/config.git")
23877 (#:load-path . ".")
23878 (#:branch . "master")
23879 (#:no-compile? . #t))
23880 ((#:name . "custom-packages")
23881 (#:url . "https://git.example.org/custom-packages.git")
23882 (#:load-path . ".")
23883 (#:branch . "master")
23884 (#:no-compile? . #t)))))))
23886 (service cuirass-service-type
23887 (cuirass-configuration
23888 (specifications %cuirass-specs)))
23891 While information related to build jobs is located directly in the
23892 specifications, global settings for the @command{cuirass} process are
23893 accessible in other @code{cuirass-configuration} fields.
23895 @deftp {Data Type} cuirass-configuration
23896 Data type representing the configuration of Cuirass.
23899 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
23900 Location of the log file.
23902 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
23903 Location of the log file used by the web interface.
23905 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
23906 Location of the repository cache.
23908 @item @code{user} (default: @code{"cuirass"})
23909 Owner of the @code{cuirass} process.
23911 @item @code{group} (default: @code{"cuirass"})
23912 Owner's group of the @code{cuirass} process.
23914 @item @code{interval} (default: @code{60})
23915 Number of seconds between the poll of the repositories followed by the
23918 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
23919 Location of sqlite database which contains the build results and previously
23920 added specifications.
23922 @item @code{ttl} (default: @code{(* 30 24 3600)})
23923 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
23924 are registered for build results. This means that build results are protected
23925 from garbage collection for at least @var{ttl} seconds.
23927 @item @code{port} (default: @code{8081})
23928 Port number used by the HTTP server.
23930 @item @code{host} (default: @code{"localhost"})
23931 Listen on the network interface for @var{host}. The default is to
23932 accept connections from localhost.
23934 @item @code{specifications} (default: @code{#~'()})
23935 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
23936 where a specification is an association list
23937 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
23938 keys are keywords (@code{#:keyword-example}) as shown in the example
23941 @item @code{use-substitutes?} (default: @code{#f})
23942 This allows using substitutes to avoid building every dependencies of a job
23945 @item @code{one-shot?} (default: @code{#f})
23946 Only evaluate specifications and build derivations once.
23948 @item @code{fallback?} (default: @code{#f})
23949 When substituting a pre-built binary fails, fall back to building
23952 @item @code{extra-options} (default: @code{'()})
23953 Extra options to pass when running the Cuirass processes.
23955 @item @code{cuirass} (default: @code{cuirass})
23956 The Cuirass package to use.
23960 @node Power Management Services
23961 @subsection Power Management Services
23964 @cindex power management with TLP
23965 @subsubheading TLP daemon
23967 The @code{(gnu services pm)} module provides a Guix service definition
23968 for the Linux power management tool TLP.
23970 TLP enables various powersaving modes in userspace and kernel.
23971 Contrary to @code{upower-service}, it is not a passive,
23972 monitoring tool, as it will apply custom settings each time a new power
23973 source is detected. More information can be found at
23974 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
23976 @deffn {Scheme Variable} tlp-service-type
23977 The service type for the TLP tool. The default settings are optimised
23978 for battery life on most systems, but you can tweak them to your heart's
23979 content by adding a valid @code{tlp-configuration}:
23981 (service tlp-service-type
23983 (cpu-scaling-governor-on-ac (list "performance"))
23984 (sched-powersave-on-bat? #t)))
23988 Each parameter definition is preceded by its type; for example,
23989 @samp{boolean foo} indicates that the @code{foo} parameter
23990 should be specified as a boolean. Types starting with
23991 @code{maybe-} denote parameters that won't show up in TLP config file
23992 when their value is @code{'disabled}.
23994 @c The following documentation was initially generated by
23995 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
23996 @c documentation is better, so we shouldn't hesitate to edit below as
23997 @c needed. However if the change you want to make to this documentation
23998 @c can be done in an automated way, it's probably easier to change
23999 @c (generate-documentation) than to make it below and have to deal with
24000 @c the churn as TLP updates.
24002 Available @code{tlp-configuration} fields are:
24004 @deftypevr {@code{tlp-configuration} parameter} package tlp
24009 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
24010 Set to true if you wish to enable TLP.
24012 Defaults to @samp{#t}.
24016 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
24017 Default mode when no power supply can be detected. Alternatives are AC
24020 Defaults to @samp{"AC"}.
24024 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
24025 Number of seconds Linux kernel has to wait after the disk goes idle,
24026 before syncing on AC.
24028 Defaults to @samp{0}.
24032 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
24033 Same as @code{disk-idle-ac} but on BAT mode.
24035 Defaults to @samp{2}.
24039 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
24040 Dirty pages flushing periodicity, expressed in seconds.
24042 Defaults to @samp{15}.
24046 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
24047 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
24049 Defaults to @samp{60}.
24053 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
24054 CPU frequency scaling governor on AC mode. With intel_pstate driver,
24055 alternatives are powersave and performance. With acpi-cpufreq driver,
24056 alternatives are ondemand, powersave, performance and conservative.
24058 Defaults to @samp{disabled}.
24062 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
24063 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
24065 Defaults to @samp{disabled}.
24069 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
24070 Set the min available frequency for the scaling governor on AC.
24072 Defaults to @samp{disabled}.
24076 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
24077 Set the max available frequency for the scaling governor on AC.
24079 Defaults to @samp{disabled}.
24083 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
24084 Set the min available frequency for the scaling governor on BAT.
24086 Defaults to @samp{disabled}.
24090 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
24091 Set the max available frequency for the scaling governor on BAT.
24093 Defaults to @samp{disabled}.
24097 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
24098 Limit the min P-state to control the power dissipation of the CPU, in AC
24099 mode. Values are stated as a percentage of the available performance.
24101 Defaults to @samp{disabled}.
24105 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
24106 Limit the max P-state to control the power dissipation of the CPU, in AC
24107 mode. Values are stated as a percentage of the available performance.
24109 Defaults to @samp{disabled}.
24113 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
24114 Same as @code{cpu-min-perf-on-ac} on BAT mode.
24116 Defaults to @samp{disabled}.
24120 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
24121 Same as @code{cpu-max-perf-on-ac} on BAT mode.
24123 Defaults to @samp{disabled}.
24127 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
24128 Enable CPU turbo boost feature on AC mode.
24130 Defaults to @samp{disabled}.
24134 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
24135 Same as @code{cpu-boost-on-ac?} on BAT mode.
24137 Defaults to @samp{disabled}.
24141 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
24142 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
24143 used under light load conditions.
24145 Defaults to @samp{#f}.
24149 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
24150 Same as @code{sched-powersave-on-ac?} but on BAT mode.
24152 Defaults to @samp{#t}.
24156 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
24157 Enable Linux kernel NMI watchdog.
24159 Defaults to @samp{#f}.
24163 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
24164 For Linux kernels with PHC patch applied, change CPU voltages. An
24165 example value would be @samp{"F:V F:V F:V F:V"}.
24167 Defaults to @samp{disabled}.
24171 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
24172 Set CPU performance versus energy saving policy on AC. Alternatives are
24173 performance, normal, powersave.
24175 Defaults to @samp{"performance"}.
24179 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
24180 Same as @code{energy-perf-policy-ac} but on BAT mode.
24182 Defaults to @samp{"powersave"}.
24186 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
24191 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
24192 Hard disk advanced power management level.
24196 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
24197 Same as @code{disk-apm-bat} but on BAT mode.
24201 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
24202 Hard disk spin down timeout. One value has to be specified for each
24203 declared hard disk.
24205 Defaults to @samp{disabled}.
24209 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
24210 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
24212 Defaults to @samp{disabled}.
24216 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
24217 Select IO scheduler for disk devices. One value has to be specified for
24218 each declared hard disk. Example alternatives are cfq, deadline and
24221 Defaults to @samp{disabled}.
24225 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
24226 SATA aggressive link power management (ALPM) level. Alternatives are
24227 min_power, medium_power, max_performance.
24229 Defaults to @samp{"max_performance"}.
24233 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
24234 Same as @code{sata-linkpwr-ac} but on BAT mode.
24236 Defaults to @samp{"min_power"}.
24240 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
24241 Exclude specified SATA host devices for link power management.
24243 Defaults to @samp{disabled}.
24247 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
24248 Enable Runtime Power Management for AHCI controller and disks on AC
24251 Defaults to @samp{disabled}.
24255 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
24256 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
24258 Defaults to @samp{disabled}.
24262 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
24263 Seconds of inactivity before disk is suspended.
24265 Defaults to @samp{15}.
24269 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
24270 PCI Express Active State Power Management level. Alternatives are
24271 default, performance, powersave.
24273 Defaults to @samp{"performance"}.
24277 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
24278 Same as @code{pcie-aspm-ac} but on BAT mode.
24280 Defaults to @samp{"powersave"}.
24284 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
24285 Radeon graphics clock speed level. Alternatives are low, mid, high,
24288 Defaults to @samp{"high"}.
24292 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
24293 Same as @code{radeon-power-ac} but on BAT mode.
24295 Defaults to @samp{"low"}.
24299 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
24300 Radeon dynamic power management method (DPM). Alternatives are battery,
24303 Defaults to @samp{"performance"}.
24307 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
24308 Same as @code{radeon-dpm-state-ac} but on BAT mode.
24310 Defaults to @samp{"battery"}.
24314 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
24315 Radeon DPM performance level. Alternatives are auto, low, high.
24317 Defaults to @samp{"auto"}.
24321 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
24322 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
24324 Defaults to @samp{"auto"}.
24328 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
24329 Wifi power saving mode.
24331 Defaults to @samp{#f}.
24335 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
24336 Same as @code{wifi-power-ac?} but on BAT mode.
24338 Defaults to @samp{#t}.
24342 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
24343 Disable wake on LAN.
24345 Defaults to @samp{#t}.
24349 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
24350 Timeout duration in seconds before activating audio power saving on
24351 Intel HDA and AC97 devices. A value of 0 disables power saving.
24353 Defaults to @samp{0}.
24357 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
24358 Same as @code{sound-powersave-ac} but on BAT mode.
24360 Defaults to @samp{1}.
24364 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
24365 Disable controller in powersaving mode on Intel HDA devices.
24367 Defaults to @samp{#t}.
24371 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
24372 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
24373 powered on again by releasing (and reinserting) the eject lever or by
24374 pressing the disc eject button on newer models.
24376 Defaults to @samp{#f}.
24380 @deftypevr {@code{tlp-configuration} parameter} string bay-device
24381 Name of the optical drive device to power off.
24383 Defaults to @samp{"sr0"}.
24387 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
24388 Runtime Power Management for PCI(e) bus devices. Alternatives are on
24391 Defaults to @samp{"on"}.
24395 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
24396 Same as @code{runtime-pm-ac} but on BAT mode.
24398 Defaults to @samp{"auto"}.
24402 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
24403 Runtime Power Management for all PCI(e) bus devices, except blacklisted
24406 Defaults to @samp{#t}.
24410 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
24411 Exclude specified PCI(e) device addresses from Runtime Power Management.
24413 Defaults to @samp{disabled}.
24417 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
24418 Exclude PCI(e) devices assigned to the specified drivers from Runtime
24423 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
24424 Enable USB autosuspend feature.
24426 Defaults to @samp{#t}.
24430 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
24431 Exclude specified devices from USB autosuspend.
24433 Defaults to @samp{disabled}.
24437 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
24438 Exclude WWAN devices from USB autosuspend.
24440 Defaults to @samp{#t}.
24444 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
24445 Include specified devices into USB autosuspend, even if they are already
24446 excluded by the driver or via @code{usb-blacklist-wwan?}.
24448 Defaults to @samp{disabled}.
24452 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
24453 Enable USB autosuspend before shutdown.
24455 Defaults to @samp{disabled}.
24459 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
24460 Restore radio device state (bluetooth, wifi, wwan) from previous
24461 shutdown on system startup.
24463 Defaults to @samp{#f}.
24468 @cindex CPU frequency scaling with thermald
24469 @subsubheading Thermald daemon
24471 The @code{(gnu services pm)} module provides an interface to
24472 thermald, a CPU frequency scaling service which helps prevent overheating.
24474 @defvr {Scheme Variable} thermald-service-type
24475 This is the service type for
24476 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
24477 Thermal Daemon, which is responsible for controlling the thermal state
24478 of processors and preventing overheating.
24481 @deftp {Data Type} thermald-configuration
24482 Data type representing the configuration of @code{thermald-service-type}.
24485 @item @code{ignore-cpuid-check?} (default: @code{#f})
24486 Ignore cpuid check for supported CPU models.
24488 @item @code{thermald} (default: @var{thermald})
24489 Package object of thermald.
24494 @node Audio Services
24495 @subsection Audio Services
24497 The @code{(gnu services audio)} module provides a service to start MPD
24498 (the Music Player Daemon).
24501 @subsubheading Music Player Daemon
24503 The Music Player Daemon (MPD) is a service that can play music while
24504 being controlled from the local machine or over the network by a variety
24507 The following example shows how one might run @code{mpd} as user
24508 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
24511 (service mpd-service-type
24517 @defvr {Scheme Variable} mpd-service-type
24518 The service type for @command{mpd}
24521 @deftp {Data Type} mpd-configuration
24522 Data type representing the configuration of @command{mpd}.
24525 @item @code{user} (default: @code{"mpd"})
24526 The user to run mpd as.
24528 @item @code{music-dir} (default: @code{"~/Music"})
24529 The directory to scan for music files.
24531 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
24532 The directory to store playlists.
24534 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
24535 The location of the music database.
24537 @item @code{state-file} (default: @code{"~/.mpd/state"})
24538 The location of the file that stores current MPD's state.
24540 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
24541 The location of the sticker database.
24543 @item @code{port} (default: @code{"6600"})
24544 The port to run mpd on.
24546 @item @code{address} (default: @code{"any"})
24547 The address that mpd will bind to. To use a Unix domain socket,
24548 an absolute path can be specified here.
24550 @item @code{outputs} (default: @code{"(list (mpd-output))"})
24551 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
24556 @deftp {Data Type} mpd-output
24557 Data type representing an @command{mpd} audio output.
24560 @item @code{name} (default: @code{"MPD"})
24561 The name of the audio output.
24563 @item @code{type} (default: @code{"pulse"})
24564 The type of audio output.
24566 @item @code{enabled?} (default: @code{#t})
24567 Specifies whether this audio output is enabled when MPD is started. By
24568 default, all audio outputs are enabled. This is just the default
24569 setting when there is no state file; with a state file, the previous
24572 @item @code{tags?} (default: @code{#t})
24573 If set to @code{#f}, then MPD will not send tags to this output. This
24574 is only useful for output plugins that can receive tags, for example the
24575 @code{httpd} output plugin.
24577 @item @code{always-on?} (default: @code{#f})
24578 If set to @code{#t}, then MPD attempts to keep this audio output always
24579 open. This may be useful for streaming servers, when you don’t want to
24580 disconnect all listeners even when playback is accidentally stopped.
24582 @item @code{mixer-type}
24583 This field accepts a symbol that specifies which mixer should be used
24584 for this audio output: the @code{hardware} mixer, the @code{software}
24585 mixer, the @code{null} mixer (allows setting the volume, but with no
24586 effect; this can be used as a trick to implement an external mixer
24587 External Mixer) or no mixer (@code{none}).
24589 @item @code{extra-options} (default: @code{'()"})
24590 An association list of option symbols to string values to be appended to
24591 the audio output configuration.
24596 The following example shows a configuration of @code{mpd} that provides
24597 an HTTP audio streaming output.
24600 (service mpd-service-type
24608 `((encoder . "vorbis")
24609 (port . "8080"))))))))
24613 @node Virtualization Services
24614 @subsection Virtualization services
24616 The @code{(gnu services virtualization)} module provides services for
24617 the libvirt and virtlog daemons, as well as other virtualization-related
24620 @subsubheading Libvirt daemon
24621 @code{libvirtd} is the server side daemon component of the libvirt
24622 virtualization management system. This daemon runs on host servers
24623 and performs required management tasks for virtualized guests.
24625 @deffn {Scheme Variable} libvirt-service-type
24626 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
24627 Its value must be a @code{libvirt-configuration}.
24630 (service libvirt-service-type
24631 (libvirt-configuration
24632 (unix-sock-group "libvirt")
24633 (tls-port "16555")))
24637 @c Auto-generated with (generate-libvirt-documentation)
24638 Available @code{libvirt-configuration} fields are:
24640 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
24645 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
24646 Flag listening for secure TLS connections on the public TCP/IP port.
24647 must set @code{listen} for this to have any effect.
24649 It is necessary to setup a CA and issue server certificates before using
24652 Defaults to @samp{#t}.
24656 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
24657 Listen for unencrypted TCP connections on the public TCP/IP port. must
24658 set @code{listen} for this to have any effect.
24660 Using the TCP socket requires SASL authentication by default. Only SASL
24661 mechanisms which support data encryption are allowed. This is
24662 DIGEST_MD5 and GSSAPI (Kerberos5)
24664 Defaults to @samp{#f}.
24668 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
24669 Port for accepting secure TLS connections This can be a port number, or
24672 Defaults to @samp{"16514"}.
24676 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
24677 Port for accepting insecure TCP connections This can be a port number,
24680 Defaults to @samp{"16509"}.
24684 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
24685 IP address or hostname used for client connections.
24687 Defaults to @samp{"0.0.0.0"}.
24691 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
24692 Flag toggling mDNS advertisement of the libvirt service.
24694 Alternatively can disable for all services on a host by stopping the
24697 Defaults to @samp{#f}.
24701 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
24702 Default mDNS advertisement name. This must be unique on the immediate
24705 Defaults to @samp{"Virtualization Host <hostname>"}.
24709 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
24710 UNIX domain socket group ownership. This can be used to allow a
24711 'trusted' set of users access to management capabilities without
24714 Defaults to @samp{"root"}.
24718 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
24719 UNIX socket permissions for the R/O socket. This is used for monitoring
24722 Defaults to @samp{"0777"}.
24726 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
24727 UNIX socket permissions for the R/W socket. Default allows only root.
24728 If PolicyKit is enabled on the socket, the default will change to allow
24729 everyone (eg, 0777)
24731 Defaults to @samp{"0770"}.
24735 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
24736 UNIX socket permissions for the admin socket. Default allows only owner
24737 (root), do not change it unless you are sure to whom you are exposing
24740 Defaults to @samp{"0777"}.
24744 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
24745 The directory in which sockets will be found/created.
24747 Defaults to @samp{"/var/run/libvirt"}.
24751 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
24752 Authentication scheme for UNIX read-only sockets. By default socket
24753 permissions allow anyone to connect
24755 Defaults to @samp{"polkit"}.
24759 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
24760 Authentication scheme for UNIX read-write sockets. By default socket
24761 permissions only allow root. If PolicyKit support was compiled into
24762 libvirt, the default will be to use 'polkit' auth.
24764 Defaults to @samp{"polkit"}.
24768 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
24769 Authentication scheme for TCP sockets. If you don't enable SASL, then
24770 all TCP traffic is cleartext. Don't do this outside of a dev/test
24773 Defaults to @samp{"sasl"}.
24777 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
24778 Authentication scheme for TLS sockets. TLS sockets already have
24779 encryption provided by the TLS layer, and limited authentication is done
24782 It is possible to make use of any SASL authentication mechanism as well,
24783 by using 'sasl' for this option
24785 Defaults to @samp{"none"}.
24789 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
24790 API access control scheme.
24792 By default an authenticated user is allowed access to all APIs. Access
24793 drivers can place restrictions on this.
24795 Defaults to @samp{()}.
24799 @deftypevr {@code{libvirt-configuration} parameter} string key-file
24800 Server key file path. If set to an empty string, then no private key is
24803 Defaults to @samp{""}.
24807 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
24808 Server key file path. If set to an empty string, then no certificate is
24811 Defaults to @samp{""}.
24815 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
24816 Server key file path. If set to an empty string, then no CA certificate
24819 Defaults to @samp{""}.
24823 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
24824 Certificate revocation list path. If set to an empty string, then no
24827 Defaults to @samp{""}.
24831 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
24832 Disable verification of our own server certificates.
24834 When libvirtd starts it performs some sanity checks against its own
24837 Defaults to @samp{#f}.
24841 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
24842 Disable verification of client certificates.
24844 Client certificate verification is the primary authentication mechanism.
24845 Any client which does not present a certificate signed by the CA will be
24848 Defaults to @samp{#f}.
24852 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
24853 Whitelist of allowed x509 Distinguished Name.
24855 Defaults to @samp{()}.
24859 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
24860 Whitelist of allowed SASL usernames. The format for username depends on
24861 the SASL authentication mechanism.
24863 Defaults to @samp{()}.
24867 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
24868 Override the compile time default TLS priority string. The default is
24869 usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
24870 is desired for libvirt to deviate from the global default settings.
24872 Defaults to @samp{"NORMAL"}.
24876 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
24877 Maximum number of concurrent client connections to allow over all
24880 Defaults to @samp{5000}.
24884 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
24885 Maximum length of queue of connections waiting to be accepted by the
24886 daemon. Note, that some protocols supporting retransmission may obey
24887 this so that a later reattempt at connection succeeds.
24889 Defaults to @samp{1000}.
24893 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
24894 Maximum length of queue of accepted but not yet authenticated clients.
24895 Set this to zero to turn this feature off
24897 Defaults to @samp{20}.
24901 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
24902 Number of workers to start up initially.
24904 Defaults to @samp{5}.
24908 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
24909 Maximum number of worker threads.
24911 If the number of active clients exceeds @code{min-workers}, then more
24912 threads are spawned, up to max_workers limit. Typically you'd want
24913 max_workers to equal maximum number of clients allowed.
24915 Defaults to @samp{20}.
24919 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
24920 Number of priority workers. If all workers from above pool are stuck,
24921 some calls marked as high priority (notably domainDestroy) can be
24922 executed in this pool.
24924 Defaults to @samp{5}.
24928 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
24929 Total global limit on concurrent RPC calls.
24931 Defaults to @samp{20}.
24935 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
24936 Limit on concurrent requests from a single client connection. To avoid
24937 one client monopolizing the server this should be a small fraction of
24938 the global max_requests and max_workers parameter.
24940 Defaults to @samp{5}.
24944 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
24945 Same as @code{min-workers} but for the admin interface.
24947 Defaults to @samp{1}.
24951 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
24952 Same as @code{max-workers} but for the admin interface.
24954 Defaults to @samp{5}.
24958 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
24959 Same as @code{max-clients} but for the admin interface.
24961 Defaults to @samp{5}.
24965 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
24966 Same as @code{max-queued-clients} but for the admin interface.
24968 Defaults to @samp{5}.
24972 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
24973 Same as @code{max-client-requests} but for the admin interface.
24975 Defaults to @samp{5}.
24979 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
24980 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
24982 Defaults to @samp{3}.
24986 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
24989 A filter allows to select a different logging level for a given category
24990 of logs The format for a filter is one of:
25001 where @code{name} is a string which is matched against the category
25002 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
25003 file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
25004 name in the filter can be a substring of the full category name, in
25005 order to match multiple similar categories), the optional @samp{"+"}
25006 prefix tells libvirt to log stack trace for each message matching name,
25007 and @code{x} is the minimal level where matching messages should be
25025 Multiple filters can be defined in a single filters statement, they just
25026 need to be separated by spaces.
25028 Defaults to @samp{"3:remote 4:event"}.
25032 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
25035 An output is one of the places to save logging information. The format
25036 for an output can be:
25040 output goes to stderr
25042 @item x:syslog:name
25043 use syslog for the output and use the given name as the ident
25045 @item x:file:file_path
25046 output to a file, with the given filepath
25049 output to journald logging system
25053 In all case the x prefix is the minimal level, acting as a filter
25070 Multiple outputs can be defined, they just need to be separated by
25073 Defaults to @samp{"3:stderr"}.
25077 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
25078 Allows usage of the auditing subsystem to be altered
25082 0: disable all auditing
25085 1: enable auditing, only if enabled on host
25088 2: enable auditing, and exit if disabled on host.
25092 Defaults to @samp{1}.
25096 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
25097 Send audit messages via libvirt logging infrastructure.
25099 Defaults to @samp{#f}.
25103 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
25104 Host UUID. UUID must not have all digits be the same.
25106 Defaults to @samp{""}.
25110 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
25111 Source to read host UUID.
25115 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
25118 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
25122 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
25125 Defaults to @samp{"smbios"}.
25129 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
25130 A keepalive message is sent to a client after @code{keepalive_interval}
25131 seconds of inactivity to check if the client is still responding. If
25132 set to -1, libvirtd will never send keepalive requests; however clients
25133 can still send them and the daemon will send responses.
25135 Defaults to @samp{5}.
25139 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
25140 Maximum number of keepalive messages that are allowed to be sent to the
25141 client without getting any response before the connection is considered
25144 In other words, the connection is automatically closed approximately
25145 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
25146 the last message received from the client. When @code{keepalive-count}
25147 is set to 0, connections will be automatically closed after
25148 @code{keepalive-interval} seconds of inactivity without sending any
25149 keepalive messages.
25151 Defaults to @samp{5}.
25155 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
25156 Same as above but for admin interface.
25158 Defaults to @samp{5}.
25162 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
25163 Same as above but for admin interface.
25165 Defaults to @samp{5}.
25169 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
25170 Timeout for Open vSwitch calls.
25172 The @code{ovs-vsctl} utility is used for the configuration and its
25173 timeout option is set by default to 5 seconds to avoid potential
25174 infinite waits blocking libvirt.
25176 Defaults to @samp{5}.
25180 @c %end of autogenerated docs
25182 @subsubheading Virtlog daemon
25183 The virtlogd service is a server side daemon component of libvirt that is
25184 used to manage logs from virtual machine consoles.
25186 This daemon is not used directly by libvirt client applications, rather it
25187 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
25188 standalone daemon, the main @code{libvirtd} daemon can be restarted without
25189 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
25190 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
25192 @deffn {Scheme Variable} virtlog-service-type
25193 This is the type of the virtlog daemon.
25194 Its value must be a @code{virtlog-configuration}.
25197 (service virtlog-service-type
25198 (virtlog-configuration
25199 (max-clients 1000)))
25203 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
25204 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
25206 Defaults to @samp{3}.
25210 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
25213 A filter allows to select a different logging level for a given category
25214 of logs The format for a filter is one of:
25225 where @code{name} is a string which is matched against the category
25226 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
25227 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
25228 be a substring of the full category name, in order to match multiple
25229 similar categories), the optional "+" prefix tells libvirt to log stack
25230 trace for each message matching name, and @code{x} is the minimal level
25231 where matching messages should be logged:
25248 Multiple filters can be defined in a single filters statement, they just
25249 need to be separated by spaces.
25251 Defaults to @samp{"3:remote 4:event"}.
25255 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
25258 An output is one of the places to save logging information The format
25259 for an output can be:
25263 output goes to stderr
25265 @item x:syslog:name
25266 use syslog for the output and use the given name as the ident
25268 @item x:file:file_path
25269 output to a file, with the given filepath
25272 output to journald logging system
25276 In all case the x prefix is the minimal level, acting as a filter
25293 Multiple outputs can be defined, they just need to be separated by
25296 Defaults to @samp{"3:stderr"}.
25300 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
25301 Maximum number of concurrent client connections to allow over all
25304 Defaults to @samp{1024}.
25308 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
25309 Maximum file size before rolling over.
25311 Defaults to @samp{2MB}
25315 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
25316 Maximum number of backup files to keep.
25318 Defaults to @samp{3}
25321 @node Transparent Emulation with QEMU
25322 @subsubheading Transparent Emulation with QEMU
25325 @cindex @code{binfmt_misc}
25326 @code{qemu-binfmt-service-type} provides support for transparent
25327 emulation of program binaries built for different architectures---e.g.,
25328 it allows you to transparently execute an ARMv7 program on an x86_64
25329 machine. It achieves this by combining the @uref{https://www.qemu.org,
25330 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
25332 @defvr {Scheme Variable} qemu-binfmt-service-type
25333 This is the type of the QEMU/binfmt service for transparent emulation.
25334 Its value must be a @code{qemu-binfmt-configuration} object, which
25335 specifies the QEMU package to use as well as the architecture we want to
25339 (service qemu-binfmt-service-type
25340 (qemu-binfmt-configuration
25341 (platforms (lookup-qemu-platforms "arm" "aarch64"))))
25344 In this example, we enable transparent emulation for the ARM and aarch64
25345 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
25346 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
25347 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
25350 @deftp {Data Type} qemu-binfmt-configuration
25351 This is the configuration for the @code{qemu-binfmt} service.
25354 @item @code{platforms} (default: @code{'()})
25355 The list of emulated QEMU platforms. Each item must be a @dfn{platform
25356 object} as returned by @code{lookup-qemu-platforms} (see below).
25358 @item @code{guix-support?} (default: @code{#f})
25359 When it is true, QEMU and all its dependencies are added to the build
25360 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
25361 @option{--chroot-directory} option}). This allows the @code{binfmt_misc}
25362 handlers to be used within the build environment, which in turn means
25363 that you can transparently build programs for another architecture.
25365 For example, let's suppose you're on an x86_64 machine and you have this
25369 (service qemu-binfmt-service-type
25370 (qemu-binfmt-configuration
25371 (platforms (lookup-qemu-platforms "arm"))
25372 (guix-support? #t)))
25378 guix build -s armhf-linux inkscape
25382 and it will build Inkscape for ARMv7 @emph{as if it were a native
25383 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
25384 if you'd like to test a package build for an architecture you don't have
25387 @item @code{qemu} (default: @code{qemu})
25388 The QEMU package to use.
25392 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
25393 Return the list of QEMU platform objects corresponding to
25394 @var{platforms}@dots{}. @var{platforms} must be a list of strings
25395 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
25396 @code{"mips64el"}, and so on.
25399 @deffn {Scheme Procedure} qemu-platform? @var{obj}
25400 Return true if @var{obj} is a platform object.
25403 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
25404 Return the name of @var{platform}---a string such as @code{"arm"}.
25408 @subsubheading The Hurd in a Virtual Machine
25410 @cindex @code{hurd}
25414 Service @code{hurd-vm} provides support for running GNU/Hurd in a
25415 virtual machine (VM), a so-called ``Childhurd''. The virtual machine is
25416 a Shepherd service that can be referred to by the names @code{hurd-vm}
25417 and @code{childhurd} and be controlled with commands such as:
25421 herd stop childhurd
25424 The given GNU/Hurd operating system configuration is cross-compiled.
25426 @defvr {Scheme Variable} hurd-vm-service-type
25427 This is the type of the Hurd in a Virtual Machine service. Its value
25428 must be a @code{hurd-vm-configuration} object, which specifies the
25429 operating system (@pxref{operating-system Reference}) and the disk size
25430 for the Hurd Virtual Machine, the QEMU package to use as well as the
25431 options for running it.
25436 (service hurd-vm-service-type
25437 (hurd-vm-configuration
25438 (disk-size (* 5000 (expt 2 20))) ;5G
25439 (memory-size 1024))) ;1024MiB
25442 would create a disk image big enough to build GNU@tie{}Hello, with some
25446 @deftp {Data Type} hurd-vm-configuration
25447 The data type representing the configuration for
25448 @code{hurd-vm-service-type}.
25451 @item @code{os} (default: @var{%hurd-vm-operating-system})
25452 The operating system to instantiate. This default is bare-bones with a
25453 permissive OpenSSH secure shell daemon listening on port 2222
25454 (@pxref{Networking Services, @code{openssh-service-type}}).
25456 @item @code{qemu} (default: @code{qemu-minimal})
25457 The QEMU package to use.
25459 @item @code{image} (default: @var{hurd-vm-disk-image})
25460 The procedure used to build the disk-image built from this
25463 @item @code{disk-size} (default: @code{'guess})
25464 The size of the disk image.
25466 @item @code{memory-size} (default: @code{512})
25467 The memory size of the Virtual Machine in mebibytes.
25469 @item @code{options} (default: @code{'("--snapshot")})
25470 The extra options for running QEMU.
25472 @item @code{id} (default: @code{#f})
25473 If set, a non-zero positive integer used to parameterize Childhurd
25474 instances. It is appended to the service's name,
25475 e.g. @code{childhurd1}.
25477 @item @code{net-options} (default: @var{hurd-vm-net-options})
25478 The procedure used to produce the list of QEMU networking options.
25480 By default, it produces
25483 '("--device" "rtl8139,netdev=net0"
25484 "--netdev" "user,id=net0\
25485 ,hostfwd=tcp:127.0.0.1:<secrets-port>-:1004\
25486 ,hostfwd=tcp:127.0.0.1:<ssh-port>-:2222\
25487 ,hostfwd=tcp:127.0.0.1:<vnc-port>-:5900")
25489 with forwarded ports
25491 <ssh-port>: @code{(+ 11004 (* 1000 @var{ID}))}
25492 <ssh-port>: @code{(+ 10022 (* 1000 @var{ID}))}
25493 <vnc-port>: @code{(+ 15900 (* 1000 @var{ID}))}
25496 @item @code{secret-root} (default: @file{/etc/childhurd})
25497 The root directory with out-of-band secrets to be installed into the
25498 childhurd once it runs. Childhurds are volatile which means that on
25499 every startup, secrets such as the SSH host keys and Guix signing key
25502 If the @file{/etc/childhurd} directory does not exist, the
25503 @code{secret-service} running in the Childhurd will be sent an empty
25506 Typical use to populate @file{"/etc/childhurd"} with a tree of
25507 non-volatile secrets, like so
25510 /etc/childhurd/etc/guix/signing-key.pub
25511 /etc/childhurd/etc/guix/signing-key.sec
25512 /etc/childhurd/etc/ssh/ssh_host_ed25519_key
25513 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key
25514 /etc/childhurd/etc/ssh/ssh_host_ed25519_key.pub
25515 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key.pub
25518 to be sent to the Childhurd, including permissions.
25523 Note that by default the VM image is volatile, i.e., once stopped the
25524 contents are lost. If you want a stateful image instead, override the
25525 configuration's @code{image} and @code{options} without
25526 the @code{--snapshot} flag using something along these lines:
25529 (service hurd-vm-service-type
25530 (hurd-vm-configuration
25531 (image (const "/out/of/store/writable/hurd.img"))
25532 (options '("--hda"))))
25535 @subsubheading Ganeti
25540 This service is considered experimental. Configuration options may be changed
25541 in a backwards-incompatible manner, and not all features have been thorougly
25542 tested. Users of this service are encouraged to share their experience at
25543 @email{guix-devel@@gnu.org}.
25546 Ganeti is a virtual machine management system. It is designed to keep virtual
25547 machines running on a cluster of servers even in the event of hardware failures,
25548 and to make maintenance and recovery tasks easy. It consists of multiple
25549 services which are described later in this section. In addition to the Ganeti
25550 service, you will need the OpenSSH service (@pxref{Networking Services,
25551 @code{openssh-service-type}}), and update the @file{/etc/hosts} file
25552 (@pxref{operating-system Reference, @code{hosts-file}}) with the cluster name
25553 and address (or use a DNS server).
25555 All nodes participating in a Ganeti cluster should have the same Ganeti and
25556 @file{/etc/hosts} configuration. Here is an example configuration for a Ganeti
25557 cluster node that supports multiple storage backends, and installs the
25558 @code{debootstrap} and @code{guix} @dfn{OS providers}:
25561 (use-package-modules virtualization)
25562 (use-service-modules base ganeti networking ssh)
25565 (host-name "node1")
25566 (hosts-file (plain-file "hosts" (format #f "
25567 127.0.0.1 localhost
25570 192.168.1.200 ganeti.example.com
25571 192.168.1.201 node1.example.com node1
25572 192.168.1.202 node2.example.com node2
25575 ;; Install QEMU so we can use KVM-based instances, and LVM, DRBD and Ceph
25576 ;; in order to use the "plain", "drbd" and "rbd" storage backends.
25577 (packages (append (map specification->package
25578 '("qemu" "lvm2" "drbd-utils" "ceph"
25579 ;; Add the debootstrap and guix OS providers.
25580 "ganeti-instance-guix" "ganeti-instance-debootstrap"))
25583 (append (list (static-networking-service "eth0" "192.168.1.201"
25584 #:netmask "255.255.255.0"
25585 #:gateway "192.168.1.254"
25586 #:name-servers '("192.168.1.252"
25589 ;; Ganeti uses SSH to communicate between nodes.
25590 (service openssh-service-type
25591 (openssh-configuration
25592 (permit-root-login 'without-password)))
25594 (service ganeti-service-type
25595 (ganeti-configuration
25596 ;; This list specifies allowed file system paths
25597 ;; for storing virtual machine images.
25598 (file-storage-paths '("/srv/ganeti/file-storage"))
25599 ;; This variable configures a single "variant" for
25600 ;; both Debootstrap and Guix that works with KVM.
25601 (os %default-ganeti-os))))
25605 Users are advised to read the
25606 @url{http://docs.ganeti.org/ganeti/master/html/admin.html,Ganeti
25607 administrators guide} to learn about the various cluster options and
25608 day-to-day operations. There is also a
25609 @url{https://guix.gnu.org/blog/2020/running-a-ganeti-cluster-on-guix/,blog post}
25610 describing how to configure and initialize a small cluster.
25612 @defvr {Scheme Variable} ganeti-service-type
25613 This is a service type that includes all the various services that Ganeti
25616 Its value is a @code{ganeti-configuration} object that defines the package
25617 to use for CLI operations, as well as configuration for the various daemons.
25618 Allowed file storage paths and available guest operating systems are also
25619 configured through this data type.
25622 @deftp {Data Type} ganeti-configuration
25623 The @code{ganeti} service takes the following configuration options:
25626 @item @code{ganeti} (default: @code{ganeti})
25627 The @code{ganeti} package to use. It will be installed to the system profile
25628 and make @command{gnt-cluster}, @command{gnt-instance}, etc available. Note
25629 that the value specified here does not affect the other services as each refer
25630 to a specific @code{ganeti} package (see below).
25632 @item @code{noded-configuration} (default: @code{(ganeti-noded-configuration)})
25633 @itemx @code{confd-configuration} (default: @code{(ganeti-confd-configuration)})
25634 @itemx @code{wconfd-configuration} (default: @code{(ganeti-wconfd-configuration)})
25635 @itemx @code{luxid-configuration} (default: @code{(ganeti-luxid-configuration)})
25636 @itemx @code{rapi-configuration} (default: @code{(ganeti-rapi-configuration)})
25637 @itemx @code{kvmd-configuration} (default: @code{(ganeti-kvmd-configuration)})
25638 @itemx @code{mond-configuration} (default: @code{(ganeti-mond-configuration)})
25639 @itemx @code{metad-configuration} (default: @code{(ganeti-metad-configuration)})
25640 @itemx @code{watcher-configuration} (default: @code{(ganeti-watcher-configuration)})
25641 @itemx @code{cleaner-configuration} (default: @code{(ganeti-cleaner-configuration)})
25643 These options control the various daemons and cron jobs that are distributed
25644 with Ganeti. The possible values for these are described in detail below.
25645 To override a setting, you must use the configuration type for that service:
25648 (service ganeti-service-type
25649 (ganeti-configuration
25650 (rapi-configuration
25651 (ganeti-rapi-configuration
25652 (interface "eth1"))))
25653 (watcher-configuration
25654 (ganeti-watcher-configuration
25655 (rapi-ip "10.0.0.1"))))
25658 @item @code{file-storage-paths} (default: @code{'()})
25659 List of allowed directories for file storage backend.
25661 @item @code{os} (default: @code{%default-ganeti-os})
25662 List of @code{<ganeti-os>} records.
25665 In essence @code{ganeti-service-type} is shorthand for declaring each service
25669 (service ganeti-noded-service-type)
25670 (service ganeti-confd-service-type)
25671 (service ganeti-wconfd-service-type)
25672 (service ganeti-luxid-service-type)
25673 (service ganeti-kvmd-service-type)
25674 (service ganeti-mond-service-type)
25675 (service ganeti-metad-service-type)
25676 (service ganeti-watcher-service-type)
25677 (service ganeti-cleaner-service-type)
25680 Plus a service extension for @code{etc-service-type} that configures the file
25681 storage backend and OS variants.
25685 @deftp {Data Type} ganeti-os
25686 This data type is suitable for passing to the @code{os} parameter of
25687 @code{ganeti-configuration}. It takes the following parameters:
25691 The name for this OS provider. It is only used to specify where the
25692 configuration ends up. Setting it to ``debootstrap'' will create
25693 @file{/etc/ganeti/instance-debootstrap}.
25695 @item @code{extension}
25696 The file extension for variants of this OS type. For example
25697 @file{.conf} or @file{.scm}.
25699 @item @code{variants} (default: @code{'()})
25700 List of @code{ganeti-os-variant} objects for this OS.
25705 @deftp {Data Type} ganeti-os-variant
25706 This is the data type for a Ganeti OS variant. It takes the following
25711 The name of this variant.
25713 @item @code{configuration}
25714 A configuration file for this variant.
25718 @defvr {Scheme Variable} %default-debootstrap-hooks
25719 This variable contains hooks to configure networking and the GRUB bootloader.
25722 @defvr {Scheme Variable} %default-debootstrap-extra-pkgs
25723 This variable contains a list of packages suitable for a fully-virtualized guest.
25726 @deftp {Data Type} debootstrap-configuration
25728 This data type creates configuration files suitable for the debootstrap OS provider.
25731 @item @code{hooks} (default: @code{%default-debootstrap-hooks})
25732 When not @code{#f}, this must be a G-expression that specifies a directory with
25733 scripts that will run when the OS is installed. It can also be a list of
25734 @code{(name . file-like)} pairs. For example:
25737 `((99-hello-world . ,(plain-file "#!/bin/sh\necho Hello, World")))
25740 That will create a directory with one executable named @code{99-hello-world}
25741 and run it every time this variant is installed. If set to @code{#f}, hooks
25742 in @file{/etc/ganeti/instance-debootstrap/hooks} will be used, if any.
25743 @item @code{proxy} (default: @code{#f})
25744 Optional HTTP proxy to use.
25745 @item @code{mirror} (default: @code{#f})
25746 The Debian mirror. Typically something like @code{http://ftp.no.debian.org/debian}.
25747 The default varies depending on the distribution.
25748 @item @code{arch} (default: @code{#f})
25749 The dpkg architecture. Set to @code{armhf} to debootstrap an ARMv7 instance
25750 on an AArch64 host. Default is to use the current system architecture.
25751 @item @code{suite} (default: @code{"stable"})
25752 When set, this must be a Debian distribution ``suite'' such as @code{buster}
25753 or @code{focal}. If set to @code{#f}, the default for the OS provider is used.
25754 @item @code{extra-pkgs} (default: @code{%default-debootstrap-extra-pkgs})
25755 List of extra packages that will get installed by dpkg in addition
25756 to the minimal system.
25757 @item @code{components} (default: @code{#f})
25758 When set, must be a list of Debian repository ``components''. For example
25759 @code{'("main" "contrib")}.
25760 @item @code{generate-cache?} (default: @code{#t})
25761 Whether to automatically cache the generated debootstrap archive.
25762 @item @code{clean-cache} (default: @code{14})
25763 Discard the cache after this amount of days. Use @code{#f} to never
25765 @item @code{partition-style} (default: @code{'msdos})
25766 The type of partition to create. When set, it must be one of
25767 @code{'msdos}, @code{'none} or a string.
25768 @item @code{partition-alignment} (default: @code{2048})
25769 Alignment of the partition in sectors.
25773 @deffn {Scheme Procedure} debootstrap-variant @var{name} @var{configuration}
25774 This is a helper procedure that creates a @code{ganeti-os-variant} record. It
25775 takes two parameters: a name and a @code{debootstrap-configuration} object.
25778 @deffn {Scheme Procedure} debootstrap-os @var{variants}@dots{}
25779 This is a helper procedure that creates a @code{ganeti-os} record. It takes
25780 a list of variants created with @code{debootstrap-variant}.
25783 @deffn {Scheme Procedure} guix-variant @var{name} @var{configuration}
25784 This is a helper procedure that creates a @code{ganeti-os-variant} record for
25785 use with the Guix OS provider. It takes a name and a G-expression that returns
25786 a ``file-like'' (@pxref{G-Expressions, file-like objects}) object containing a
25787 Guix System configuration.
25790 @deffn {Scheme Procedure} guix-os @var{variants}@dots{}
25791 This is a helper procedure that creates a @code{ganeti-os} record. It
25792 takes a list of variants produced by @code{guix-variant}.
25795 @defvr {Scheme Variable} %default-debootstrap-variants
25796 This is a convenience variable to make the debootstrap provider work
25797 ``out of the box'' without users having to declare variants manually. It
25798 contains a single debootstrap variant with the default configuration:
25801 (list (debootstrap-variant
25803 (debootstrap-configuration)))
25807 @defvr {Scheme Variable} %default-guix-variants
25808 This is a convenience variable to make the Guix OS provider work without
25809 additional configuration. It creates a virtual machine that has an SSH
25810 server, a serial console, and authorizes the Ganeti hosts SSH keys.
25813 (list (guix-variant
25815 (file-append ganeti-instance-guix
25816 "/share/doc/ganeti-instance-guix/examples/dynamic.scm")))
25820 Users can implement support for OS providers unbeknownst to Guix by extending
25821 the @code{ganeti-os} and @code{ganeti-os-variant} records appropriately.
25827 (extension ".conf")
25829 (list (ganeti-os-variant
25831 (configuration (plain-file "bar" "this is fine"))))))
25834 That creates @file{/etc/ganeti/instance-custom/variants/foo.conf} which points
25835 to a file in the store with contents @code{this is fine}. It also creates
25836 @file{/etc/ganeti/instance-custom/variants/variants.list} with contents @code{foo}.
25838 Obviously this may not work for all OS providers out there. If you find the
25839 interface limiting, please reach out to @email{guix-devel@@gnu.org}.
25841 The rest of this section documents the various services that are included by
25842 @code{ganeti-service-type}.
25844 @defvr {Scheme Variable} ganeti-noded-service-type
25845 @command{ganeti-noded} is the daemon responsible for node-specific functions
25846 within the Ganeti system. The value of this service must be a
25847 @code{ganeti-noded-configuration} object.
25850 @deftp {Data Type} ganeti-noded-configuration
25851 This is the configuration for the @code{ganeti-noded} service.
25854 @item @code{ganeti} (default: @code{ganeti})
25855 The @code{ganeti} package to use for this service.
25857 @item @code{port} (default: @code{1811})
25858 The TCP port on which the node daemon listens for network requests.
25860 @item @code{address} (default: @code{"0.0.0.0"})
25861 The network address that the daemon will bind to. The default address means
25862 bind to all available addresses.
25864 @item @code{interface} (default: @code{#f})
25865 When this is set, it must be a specific network interface (e.g.@: @code{eth0})
25866 that the daemon will bind to.
25868 @item @code{max-clients} (default: @code{20})
25869 This sets a limit on the maximum number of simultaneous client connections
25870 that the daemon will handle. Connections above this count are accepted, but
25871 no responses will be sent until enough connections have closed.
25873 @item @code{ssl?} (default: @code{#t})
25874 Whether to use SSL/TLS to encrypt network communications. The certificate
25875 is automatically provisioned by the cluster and can be rotated with
25876 @command{gnt-cluster renew-crypto}.
25878 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
25879 This can be used to provide a specific encryption key for TLS communications.
25881 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
25882 This can be used to provide a specific certificate for TLS communications.
25884 @item @code{debug?} (default: @code{#f})
25885 When true, the daemon performs additional logging for debugging purposes.
25886 Note that this will leak encryption details to the log files, use with caution.
25891 @defvr {Scheme Variable} ganeti-confd-service-type
25892 @command{ganeti-confd} answers queries related to the configuration of a
25893 Ganeti cluster. The purpose of this daemon is to have a highly available
25894 and fast way to query cluster configuration values. It is automatically
25895 active on all @dfn{master candidates}. The value of this service must be a
25896 @code{ganeti-confd-configuration} object.
25900 @deftp {Data Type} ganeti-confd-configuration
25901 This is the configuration for the @code{ganeti-confd} service.
25904 @item @code{ganeti} (default: @code{ganeti})
25905 The @code{ganeti} package to use for this service.
25907 @item @code{port} (default: @code{1814})
25908 The UDP port on which to listen for network requests.
25910 @item @code{address} (default: @code{"0.0.0.0"})
25911 Network address that the daemon will bind to.
25913 @item @code{debug?} (default: @code{#f})
25914 When true, the daemon performs additional logging for debugging purposes.
25919 @defvr {Scheme Variable} ganeti-wconfd-service-type
25920 @command{ganeti-wconfd} is the daemon that has authoritative knowledge
25921 about the cluster configuration and is the only entity that can accept
25922 changes to it. All jobs that need to modify the configuration will do so
25923 by sending appropriate requests to this daemon. It only runs on the
25924 @dfn{master node} and will automatically disable itself on other nodes.
25926 The value of this service must be a
25927 @code{ganeti-wconfd-configuration} object.
25930 @deftp {Data Type} ganeti-wconfd-configuration
25931 This is the configuration for the @code{ganeti-wconfd} service.
25934 @item @code{ganeti} (default: @code{ganeti})
25935 The @code{ganeti} package to use for this service.
25937 @item @code{no-voting?} (default: @code{#f})
25938 The daemon will refuse to start if the majority of cluster nodes does not
25939 agree that it is running on the master node. Set to @code{#t} to start
25940 even if a quorum can not be reached (dangerous, use with caution).
25942 @item @code{debug?} (default: @code{#f})
25943 When true, the daemon performs additional logging for debugging purposes.
25948 @defvr {Scheme Variable} ganeti-luxid-service-type
25949 @command{ganeti-luxid} is a daemon used to answer queries related to the
25950 configuration and the current live state of a Ganeti cluster. Additionally,
25951 it is the authoritative daemon for the Ganeti job queue. Jobs can be
25952 submitted via this daemon and it schedules and starts them.
25954 It takes a @code{ganeti-luxid-configuration} object.
25957 @deftp {Data Type} ganeti-luxid-configuration
25958 This is the configuration for the @code{ganeti-wconfd} service.
25961 @item @code{ganeti} (default: @code{ganeti})
25962 The @code{ganeti} package to use for this service.
25964 @item @code{no-voting?} (default: @code{#f})
25965 The daemon will refuse to start if it cannot verify that the majority of
25966 cluster nodes believes that it is running on the master node. Set to
25967 @code{#t} to ignore such checks and start anyway (this can be dangerous).
25969 @item @code{debug?} (default: @code{#f})
25970 When true, the daemon performs additional logging for debugging purposes.
25975 @defvr {Scheme Variable} ganeti-rapi-service-type
25976 @command{ganeti-rapi} provides a remote API for Ganeti clusters. It runs on
25977 the master node and can be used to perform cluster actions programmatically
25978 via a JSON-based RPC protocol.
25980 Most query operations are allowed without authentication (unless
25981 @var{require-authentication?} is set), whereas write operations require
25982 explicit authorization via the @file{/var/lib/ganeti/rapi/users} file. See
25983 the @url{http://docs.ganeti.org/ganeti/master/html/rapi.html, Ganeti Remote
25984 API documentation} for more information.
25986 The value of this service must be a @code{ganeti-rapi-configuration} object.
25989 @deftp {Data Type} ganeti-rapi-configuration
25990 This is the configuration for the @code{ganeti-rapi} service.
25993 @item @code{ganeti} (default: @code{ganeti})
25994 The @code{ganeti} package to use for this service.
25996 @item @code{require-authentication?} (default: @code{#f})
25997 Whether to require authentication even for read-only operations.
25999 @item @code{port} (default: @code{5080})
26000 The TCP port on which to listen to API requests.
26002 @item @code{address} (default: @code{"0.0.0.0"})
26003 The network address that the service will bind to. By default it listens
26004 on all configured addresses.
26006 @item @code{interface} (default: @code{#f})
26007 When set, it must specify a specific network interface such as @code{eth0}
26008 that the daemon will bind to.
26010 @item @code{max-clients} (default: @code{20})
26011 The maximum number of simultaneous client requests to handle. Further
26012 connections are allowed, but no responses are sent until enough connections
26015 @item @code{ssl?} (default: @code{#t})
26016 Whether to use SSL/TLS encryption on the RAPI port.
26018 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
26019 This can be used to provide a specific encryption key for TLS communications.
26021 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
26022 This can be used to provide a specific certificate for TLS communications.
26024 @item @code{debug?} (default: @code{#f})
26025 When true, the daemon performs additional logging for debugging purposes.
26026 Note that this will leak encryption details to the log files, use with caution.
26031 @defvr {Scheme Variable} ganeti-kvmd-service-type
26032 @command{ganeti-kvmd} is responsible for determining whether a given KVM
26033 instance was shut down by an administrator or a user. Normally Ganeti will
26034 restart an instance that was not stopped through Ganeti itself. If the
26035 cluster option @code{user_shutdown} is true, this daemon monitors the
26036 @code{QMP} socket provided by QEMU and listens for shutdown events, and
26037 marks the instance as @dfn{USER_down} instead of @dfn{ERROR_down} when
26038 it shuts down gracefully by itself.
26040 It takes a @code{ganeti-kvmd-configuration} object.
26043 @deftp {Data Type} ganeti-kvmd-configuration
26046 @item @code{ganeti} (default: @code{ganeti})
26047 The @code{ganeti} package to use for this service.
26049 @item @code{debug?} (default: @code{#f})
26050 When true, the daemon performs additional logging for debugging purposes.
26055 @defvr {Scheme Variable} ganeti-mond-service-type
26056 @command{ganeti-mond} is an optional daemon that provides Ganeti monitoring
26057 functionality. It is responsible for running data collectors and publish the
26058 collected information through a HTTP interface.
26060 It takes a @code{ganeti-mond-configuration} object.
26063 @deftp {Data Type} ganeti-mond-configuration
26066 @item @code{ganeti} (default: @code{ganeti})
26067 The @code{ganeti} package to use for this service.
26069 @item @code{port} (default: @code{1815})
26070 The port on which the daemon will listen.
26072 @item @code{address} (default: @code{"0.0.0.0"})
26073 The network address that the daemon will bind to. By default it binds to all
26074 available interfaces.
26076 @item @code{debug?} (default: @code{#f})
26077 When true, the daemon performs additional logging for debugging purposes.
26082 @defvr {Scheme Variable} ganeti-metad-service-type
26083 @command{ganeti-metad} is an optional daemon that can be used to provide
26084 information about the cluster to instances or OS install scripts.
26086 It takes a @code{ganeti-metad-configuration} object.
26089 @deftp {Data Type} ganeti-metad-configuration
26092 @item @code{ganeti} (default: @code{ganeti})
26093 The @code{ganeti} package to use for this service.
26095 @item @code{port} (default: @code{80})
26096 The port on which the daemon will listen.
26098 @item @code{address} (default: @code{#f})
26099 If set, the daemon will bind to this address only. If left unset, the behavior
26100 depends on the cluster configuration.
26102 @item @code{debug?} (default: @code{#f})
26103 When true, the daemon performs additional logging for debugging purposes.
26108 @defvr {Scheme Variable} ganeti-watcher-service-type
26109 @command{ganeti-watcher} is a script designed to run periodically and ensure
26110 the health of a cluster. It will automatically restart instances that have
26111 stopped without Ganetis consent, and repairs DRBD links in case a node has
26112 rebooted. It also archives old cluster jobs and restarts Ganeti daemons
26113 that are not running. If the cluster parameter @code{ensure_node_health}
26114 is set, the watcher will also shutdown instances and DRBD devices if the
26115 node it is running on is declared offline by known master candidates.
26117 It can be paused on all nodes with @command{gnt-cluster watcher pause}.
26119 The service takes a @code{ganeti-watcher-configuration} object.
26122 @deftp {Data Type} ganeti-watcher-configuration
26125 @item @code{ganeti} (default: @code{ganeti})
26126 The @code{ganeti} package to use for this service.
26128 @item @code{schedule} (default: @code{'(next-second-from (next-minute (range 0 60 5)))})
26129 How often to run the script. The default is every five minutes.
26131 @item @code{rapi-ip} (default: @code{#f})
26132 This option needs to be specified only if the RAPI daemon is configured to use
26133 a particular interface or address. By default the cluster address is used.
26135 @item @code{job-age} (default: @code{(* 6 3600)})
26136 Archive cluster jobs older than this age, specified in seconds. The default
26137 is 6 hours. This keeps @command{gnt-job list} manageable.
26139 @item @code{verify-disks?} (default: @code{#t})
26140 If this is @code{#f}, the watcher will not try to repair broken DRBD links
26141 automatically. Administrators will need to use @command{gnt-cluster verify-disks}
26144 @item @code{debug?} (default: @code{#f})
26145 When @code{#t}, the script performs additional logging for debugging purposes.
26150 @defvr {Scheme Variable} ganeti-cleaner-service-type
26151 @command{ganeti-cleaner} is a script designed to run periodically and remove
26152 old files from the cluster. This service type controls two @dfn{cron jobs}:
26153 one intended for the master node that permanently purges old cluster jobs,
26154 and one intended for every node that removes expired X509 certificates, keys,
26155 and outdated @command{ganeti-watcher} information. Like all Ganeti services,
26156 it is safe to include even on non-master nodes as it will disable itself as
26159 It takes a @code{ganeti-cleaner-configuration} object.
26162 @deftp {Data Type} ganeti-cleaner-configuration
26165 @item @code{ganeti} (default: @code{ganeti})
26166 The @code{ganeti} package to use for the @command{gnt-cleaner} command.
26168 @item @code{master-schedule} (default: @code{"45 1 * * *"})
26169 How often to run the master cleaning job. The default is once per day, at
26172 @item @code{node-schedule} (default: @code{"45 2 * * *"})
26173 How often to run the node cleaning job. The default is once per day, at
26179 @node Version Control Services
26180 @subsection Version Control Services
26182 The @code{(gnu services version-control)} module provides a service to
26183 allow remote access to local Git repositories. There are three options:
26184 the @code{git-daemon-service}, which provides access to repositories via
26185 the @code{git://} unsecured TCP-based protocol, extending the
26186 @code{nginx} web server to proxy some requests to
26187 @code{git-http-backend}, or providing a web interface with
26188 @code{cgit-service-type}.
26190 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
26192 Return a service that runs @command{git daemon}, a simple TCP server to
26193 expose repositories over the Git protocol for anonymous access.
26195 The optional @var{config} argument should be a
26196 @code{<git-daemon-configuration>} object, by default it allows read-only
26197 access to exported@footnote{By creating the magic file
26198 @file{git-daemon-export-ok} in the repository directory.} repositories under
26203 @deftp {Data Type} git-daemon-configuration
26204 Data type representing the configuration for @code{git-daemon-service}.
26207 @item @code{package} (default: @code{git})
26208 Package object of the Git distributed version control system.
26210 @item @code{export-all?} (default: @code{#f})
26211 Whether to allow access for all Git repositories, even if they do not
26212 have the @file{git-daemon-export-ok} file.
26214 @item @code{base-path} (default: @file{/srv/git})
26215 Whether to remap all the path requests as relative to the given path.
26216 If you run @command{git daemon} with @code{(base-path "/srv/git")} on
26217 @samp{example.com}, then if you later try to pull
26218 @indicateurl{git://example.com/hello.git}, git daemon will interpret the
26219 path as @file{/srv/git/hello.git}.
26221 @item @code{user-path} (default: @code{#f})
26222 Whether to allow @code{~user} notation to be used in requests. When
26223 specified with empty string, requests to
26224 @indicateurl{git://host/~alice/foo} is taken as a request to access
26225 @code{foo} repository in the home directory of user @code{alice}. If
26226 @code{(user-path "@var{path}")} is specified, the same request is taken
26227 as a request to access @file{@var{path}/foo} repository in the home
26228 directory of user @code{alice}.
26230 @item @code{listen} (default: @code{'()})
26231 Whether to listen on specific IP addresses or hostnames, defaults to
26234 @item @code{port} (default: @code{#f})
26235 Whether to listen on an alternative port, which defaults to 9418.
26237 @item @code{whitelist} (default: @code{'()})
26238 If not empty, only allow access to this list of directories.
26240 @item @code{extra-options} (default: @code{'()})
26241 Extra options will be passed to @command{git daemon}, please run
26242 @command{man git-daemon} for more information.
26247 The @code{git://} protocol lacks authentication. When you pull from a
26248 repository fetched via @code{git://}, you don't know whether the data you
26249 receive was modified or is even coming from the specified host, and your
26250 connection is subject to eavesdropping. It's better to use an authenticated
26251 and encrypted transport, such as @code{https}. Although Git allows you
26252 to serve repositories using unsophisticated file-based web servers,
26253 there is a faster protocol implemented by the @code{git-http-backend}
26254 program. This program is the back-end of a proper Git web service. It
26255 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
26256 on running the necessary @code{fcgiwrap} daemon.
26258 Guix has a separate configuration data type for serving Git repositories
26261 @deftp {Data Type} git-http-configuration
26262 Data type representing the configuration for a future
26263 @code{git-http-service-type}; can currently be used to configure Nginx
26264 trough @code{git-http-nginx-location-configuration}.
26267 @item @code{package} (default: @var{git})
26268 Package object of the Git distributed version control system.
26270 @item @code{git-root} (default: @file{/srv/git})
26271 Directory containing the Git repositories to expose to the world.
26273 @item @code{export-all?} (default: @code{#f})
26274 Whether to expose access for all Git repositories in @var{git-root},
26275 even if they do not have the @file{git-daemon-export-ok} file.
26277 @item @code{uri-path} (default: @samp{/git/})
26278 Path prefix for Git access. With the default @samp{/git/} prefix, this
26279 will map @indicateurl{http://@var{server}/git/@var{repo}.git} to
26280 @file{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
26281 with this prefix are not passed on to this Git instance.
26283 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
26284 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
26289 There is no @code{git-http-service-type}, currently; instead you can
26290 create an @code{nginx-location-configuration} from a
26291 @code{git-http-configuration} and then add that location to a web
26294 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
26295 [config=(git-http-configuration)]
26296 Compute an @code{nginx-location-configuration} that corresponds to the
26297 given Git http configuration. An example nginx service definition to
26298 serve the default @file{/srv/git} over HTTPS might be:
26301 (service nginx-service-type
26302 (nginx-configuration
26305 (nginx-server-configuration
26306 (listen '("443 ssl"))
26307 (server-name "git.my-host.org")
26309 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
26310 (ssl-certificate-key
26311 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
26314 (git-http-nginx-location-configuration
26315 (git-http-configuration (uri-path "/"))))))))))
26318 This example assumes that you are using Let's Encrypt to get your TLS
26319 certificate. @xref{Certificate Services}. The default @code{certbot}
26320 service will redirect all HTTP traffic on @code{git.my-host.org} to
26321 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
26322 system services. @xref{Web Services}.
26325 @subsubheading Cgit Service
26327 @cindex Cgit service
26328 @cindex Git, web interface
26329 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
26330 repositories written in C.
26332 The following example will configure the service with default values.
26333 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
26336 (service cgit-service-type)
26339 The @code{file-object} type designates either a file-like object
26340 (@pxref{G-Expressions, file-like objects}) or a string.
26342 @c %start of fragment
26344 Available @code{cgit-configuration} fields are:
26346 @deftypevr {@code{cgit-configuration} parameter} package package
26351 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
26352 NGINX configuration.
26356 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
26357 Specifies a command which will be invoked to format the content of about
26358 pages (both top-level and for each repository).
26360 Defaults to @samp{""}.
26364 @deftypevr {@code{cgit-configuration} parameter} string agefile
26365 Specifies a path, relative to each repository path, which can be used to
26366 specify the date and time of the youngest commit in the repository.
26368 Defaults to @samp{""}.
26372 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
26373 Specifies a command that will be invoked for authenticating repository
26376 Defaults to @samp{""}.
26380 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
26381 Flag which, when set to @samp{age}, enables date ordering in the branch
26382 ref list, and when set @samp{name} enables ordering by branch name.
26384 Defaults to @samp{"name"}.
26388 @deftypevr {@code{cgit-configuration} parameter} string cache-root
26389 Path used to store the cgit cache entries.
26391 Defaults to @samp{"/var/cache/cgit"}.
26395 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
26396 Number which specifies the time-to-live, in minutes, for the cached
26397 version of repository pages accessed with a fixed SHA1.
26399 Defaults to @samp{-1}.
26403 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
26404 Number which specifies the time-to-live, in minutes, for the cached
26405 version of repository pages accessed without a fixed SHA1.
26407 Defaults to @samp{5}.
26411 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
26412 Number which specifies the time-to-live, in minutes, for the cached
26413 version of the repository summary page.
26415 Defaults to @samp{5}.
26419 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
26420 Number which specifies the time-to-live, in minutes, for the cached
26421 version of the repository index page.
26423 Defaults to @samp{5}.
26427 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
26428 Number which specifies the time-to-live, in minutes, for the result of
26429 scanning a path for Git repositories.
26431 Defaults to @samp{15}.
26435 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
26436 Number which specifies the time-to-live, in minutes, for the cached
26437 version of the repository about page.
26439 Defaults to @samp{15}.
26443 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
26444 Number which specifies the time-to-live, in minutes, for the cached
26445 version of snapshots.
26447 Defaults to @samp{5}.
26451 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
26452 The maximum number of entries in the cgit cache. When set to @samp{0},
26453 caching is disabled.
26455 Defaults to @samp{0}.
26459 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
26460 Sort items in the repo list case sensitively.
26462 Defaults to @samp{#t}.
26466 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
26467 List of common prefixes which, when combined with a repository URL,
26468 generates valid clone URLs for the repository.
26470 Defaults to @samp{()}.
26474 @deftypevr {@code{cgit-configuration} parameter} list clone-url
26475 List of @code{clone-url} templates.
26477 Defaults to @samp{()}.
26481 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
26482 Command which will be invoked to format commit messages.
26484 Defaults to @samp{""}.
26488 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
26489 Flag which, when set to @samp{date}, enables strict date ordering in the
26490 commit log, and when set to @samp{topo} enables strict topological
26493 Defaults to @samp{"git log"}.
26497 @deftypevr {@code{cgit-configuration} parameter} file-object css
26498 URL which specifies the css document to include in all cgit pages.
26500 Defaults to @samp{"/share/cgit/cgit.css"}.
26504 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
26505 Specifies a command which will be invoked to format names and email
26506 address of committers, authors, and taggers, as represented in various
26507 places throughout the cgit interface.
26509 Defaults to @samp{""}.
26513 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
26514 Flag which, when set to @samp{#t}, will make cgit generate a HTML
26515 fragment suitable for embedding in other HTML pages.
26517 Defaults to @samp{#f}.
26521 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
26522 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
26523 commit history graph to the left of the commit messages in the
26524 repository log page.
26526 Defaults to @samp{#f}.
26530 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
26531 Flag which, when set to @samp{#t}, allows all filter settings to be
26532 overridden in repository-specific cgitrc files.
26534 Defaults to @samp{#f}.
26538 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
26539 Flag which, when set to @samp{#t}, allows users to follow a file in the
26542 Defaults to @samp{#f}.
26546 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
26547 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
26550 Defaults to @samp{#t}.
26554 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
26555 Flag which, when set to @samp{#t}, will make cgit generate extra links
26556 "summary", "commit", "tree" for each repo in the repository index.
26558 Defaults to @samp{#f}.
26562 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
26563 Flag which, when set to @samp{#t}, will make cgit display the owner of
26564 each repo in the repository index.
26566 Defaults to @samp{#t}.
26570 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
26571 Flag which, when set to @samp{#t}, will make cgit print the number of
26572 modified files for each commit on the repository log page.
26574 Defaults to @samp{#f}.
26578 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
26579 Flag which, when set to @samp{#t}, will make cgit print the number of
26580 added and removed lines for each commit on the repository log page.
26582 Defaults to @samp{#f}.
26586 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
26587 Flag which, when set to @code{#t}, will make cgit display remote
26588 branches in the summary and refs views.
26590 Defaults to @samp{#f}.
26594 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
26595 Flag which, when set to @code{1}, will make cgit use the subject of the
26596 parent commit as link text when generating links to parent commits in
26599 Defaults to @samp{#f}.
26603 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
26604 Flag which, when set to @samp{#t}, will make cgit use the subject of the
26605 parent commit as link text when generating links to parent commits in
26608 Defaults to @samp{#f}.
26612 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
26613 Flag which, when set to @samp{#t}, will make cgit generate linenumber
26614 links for plaintext blobs printed in the tree view.
26616 Defaults to @samp{#t}.
26620 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
26621 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
26622 set any repo specific settings.
26624 Defaults to @samp{#f}.
26628 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
26629 URL used as link to a shortcut icon for cgit.
26631 Defaults to @samp{"/favicon.ico"}.
26635 @deftypevr {@code{cgit-configuration} parameter} string footer
26636 The content of the file specified with this option will be included
26637 verbatim at the bottom of all pages (i.e.@: it replaces the standard
26638 "generated by..."@: message).
26640 Defaults to @samp{""}.
26644 @deftypevr {@code{cgit-configuration} parameter} string head-include
26645 The content of the file specified with this option will be included
26646 verbatim in the HTML HEAD section on all pages.
26648 Defaults to @samp{""}.
26652 @deftypevr {@code{cgit-configuration} parameter} string header
26653 The content of the file specified with this option will be included
26654 verbatim at the top of all pages.
26656 Defaults to @samp{""}.
26660 @deftypevr {@code{cgit-configuration} parameter} file-object include
26661 Name of a configfile to include before the rest of the current config-
26664 Defaults to @samp{""}.
26668 @deftypevr {@code{cgit-configuration} parameter} string index-header
26669 The content of the file specified with this option will be included
26670 verbatim above the repository index.
26672 Defaults to @samp{""}.
26676 @deftypevr {@code{cgit-configuration} parameter} string index-info
26677 The content of the file specified with this option will be included
26678 verbatim below the heading on the repository index page.
26680 Defaults to @samp{""}.
26684 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
26685 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
26686 in the servers timezone.
26688 Defaults to @samp{#f}.
26692 @deftypevr {@code{cgit-configuration} parameter} file-object logo
26693 URL which specifies the source of an image which will be used as a logo
26696 Defaults to @samp{"/share/cgit/cgit.png"}.
26700 @deftypevr {@code{cgit-configuration} parameter} string logo-link
26701 URL loaded when clicking on the cgit logo image.
26703 Defaults to @samp{""}.
26707 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
26708 Command which will be invoked to format the Owner column of the main
26711 Defaults to @samp{""}.
26715 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
26716 Number of items to display in atom feeds view.
26718 Defaults to @samp{10}.
26722 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
26723 Number of entries to list per page in "log" view.
26725 Defaults to @samp{50}.
26729 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
26730 Number of commit message characters to display in "log" view.
26732 Defaults to @samp{80}.
26736 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
26737 Specifies the number of entries to list per page on the repository index
26740 Defaults to @samp{50}.
26744 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
26745 Specifies the maximum number of repo description characters to display
26746 on the repository index page.
26748 Defaults to @samp{80}.
26752 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
26753 Specifies the maximum size of a blob to display HTML for in KBytes.
26755 Defaults to @samp{0}.
26759 @deftypevr {@code{cgit-configuration} parameter} string max-stats
26760 Maximum statistics period. Valid values are @samp{week},@samp{month},
26761 @samp{quarter} and @samp{year}.
26763 Defaults to @samp{""}.
26767 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
26768 Mimetype for the specified filename extension.
26770 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
26771 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
26772 "image/png") (svg "image/svg+xml"))}.
26776 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
26777 Specifies the file to use for automatic mimetype lookup.
26779 Defaults to @samp{""}.
26783 @deftypevr {@code{cgit-configuration} parameter} string module-link
26784 Text which will be used as the formatstring for a hyperlink when a
26785 submodule is printed in a directory listing.
26787 Defaults to @samp{""}.
26791 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
26792 If set to the value @samp{#t} caching will be disabled.
26794 Defaults to @samp{#f}.
26798 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
26799 If set to @samp{#t} showing full author email addresses will be
26802 Defaults to @samp{#f}.
26806 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
26807 Flag which, when set to @samp{#t}, will make cgit omit the standard
26808 header on all pages.
26810 Defaults to @samp{#f}.
26814 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
26815 A list of subdirectories inside of @code{repository-directory}, relative
26816 to it, that should loaded as Git repositories. An empty list means that
26817 all subdirectories will be loaded.
26819 Defaults to @samp{()}.
26823 @deftypevr {@code{cgit-configuration} parameter} file-object readme
26824 Text which will be used as default value for @code{cgit-repo-readme}.
26826 Defaults to @samp{""}.
26830 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
26831 If set to @code{#t} and @code{repository-directory} is enabled, if any
26832 repositories are found with a suffix of @code{.git}, this suffix will be
26833 removed for the URL and name.
26835 Defaults to @samp{#f}.
26839 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
26840 Maximum number of files to consider when detecting renames.
26842 Defaults to @samp{-1}.
26846 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
26847 The way in which repositories in each section are sorted.
26849 Defaults to @samp{""}.
26853 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
26854 Text used as content for the @code{robots} meta-tag.
26856 Defaults to @samp{("noindex" "nofollow")}.
26860 @deftypevr {@code{cgit-configuration} parameter} string root-desc
26861 Text printed below the heading on the repository index page.
26863 Defaults to @samp{"a fast webinterface for the git dscm"}.
26867 @deftypevr {@code{cgit-configuration} parameter} string root-readme
26868 The content of the file specified with this option will be included
26869 verbatim below the ``about'' link on the repository index page.
26871 Defaults to @samp{""}.
26875 @deftypevr {@code{cgit-configuration} parameter} string root-title
26876 Text printed as heading on the repository index page.
26878 Defaults to @samp{""}.
26882 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
26883 If set to @samp{#t} and repository-directory is enabled,
26884 repository-directory will recurse into directories whose name starts
26885 with a period. Otherwise, repository-directory will stay away from such
26886 directories, considered as ``hidden''. Note that this does not apply to
26887 the @file{.git} directory in non-bare repos.
26889 Defaults to @samp{#f}.
26893 @deftypevr {@code{cgit-configuration} parameter} list snapshots
26894 Text which specifies the default set of snapshot formats that cgit
26895 generates links for.
26897 Defaults to @samp{()}.
26901 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
26902 Name of the directory to scan for repositories (represents
26905 Defaults to @samp{"/srv/git"}.
26909 @deftypevr {@code{cgit-configuration} parameter} string section
26910 The name of the current repository section - all repositories defined
26911 after this option will inherit the current section name.
26913 Defaults to @samp{""}.
26917 @deftypevr {@code{cgit-configuration} parameter} string section-sort
26918 Flag which, when set to @samp{1}, will sort the sections on the
26919 repository listing by name.
26921 Defaults to @samp{""}.
26925 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
26926 A number which, if defined prior to repository-directory, specifies how
26927 many path elements from each repo path to use as a default section name.
26929 Defaults to @samp{0}.
26933 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
26934 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
26937 Defaults to @samp{#f}.
26941 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
26942 Specifies a command which will be invoked to format plaintext blobs in
26945 Defaults to @samp{""}.
26949 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
26950 Specifies the number of branches to display in the repository ``summary''
26953 Defaults to @samp{10}.
26957 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
26958 Specifies the number of log entries to display in the repository
26961 Defaults to @samp{10}.
26965 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
26966 Specifies the number of tags to display in the repository ``summary''
26969 Defaults to @samp{10}.
26973 @deftypevr {@code{cgit-configuration} parameter} string strict-export
26974 Filename which, if specified, needs to be present within the repository
26975 for cgit to allow access to that repository.
26977 Defaults to @samp{""}.
26981 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
26982 URL which, if specified, will be used as root for all cgit links.
26984 Defaults to @samp{"/"}.
26988 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
26989 A list of @dfn{cgit-repo} records to use with config.
26991 Defaults to @samp{()}.
26993 Available @code{repository-cgit-configuration} fields are:
26995 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
26996 A mask of snapshot formats for this repo that cgit generates links for,
26997 restricted by the global @code{snapshots} setting.
26999 Defaults to @samp{()}.
27003 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
27004 Override the default @code{source-filter}.
27006 Defaults to @samp{""}.
27010 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
27011 The relative URL used to access the repository.
27013 Defaults to @samp{""}.
27017 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
27018 Override the default @code{about-filter}.
27020 Defaults to @samp{""}.
27024 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
27025 Flag which, when set to @samp{age}, enables date ordering in the branch
27026 ref list, and when set to @samp{name} enables ordering by branch name.
27028 Defaults to @samp{""}.
27032 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
27033 A list of URLs which can be used to clone repo.
27035 Defaults to @samp{()}.
27039 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
27040 Override the default @code{commit-filter}.
27042 Defaults to @samp{""}.
27046 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
27047 Flag which, when set to @samp{date}, enables strict date ordering in the
27048 commit log, and when set to @samp{topo} enables strict topological
27051 Defaults to @samp{""}.
27055 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
27056 The name of the default branch for this repository. If no such branch
27057 exists in the repository, the first branch name (when sorted) is used as
27058 default instead. By default branch pointed to by HEAD, or ``master'' if
27059 there is no suitable HEAD.
27061 Defaults to @samp{""}.
27065 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
27066 The value to show as repository description.
27068 Defaults to @samp{""}.
27072 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
27073 The value to show as repository homepage.
27075 Defaults to @samp{""}.
27079 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
27080 Override the default @code{email-filter}.
27082 Defaults to @samp{""}.
27086 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
27087 A flag which can be used to disable the global setting
27088 @code{enable-commit-graph?}.
27090 Defaults to @samp{disabled}.
27094 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
27095 A flag which can be used to disable the global setting
27096 @code{enable-log-filecount?}.
27098 Defaults to @samp{disabled}.
27102 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
27103 A flag which can be used to disable the global setting
27104 @code{enable-log-linecount?}.
27106 Defaults to @samp{disabled}.
27110 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
27111 Flag which, when set to @code{#t}, will make cgit display remote
27112 branches in the summary and refs views.
27114 Defaults to @samp{disabled}.
27118 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
27119 A flag which can be used to override the global setting
27120 @code{enable-subject-links?}.
27122 Defaults to @samp{disabled}.
27126 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
27127 A flag which can be used to override the global setting
27128 @code{enable-html-serving?}.
27130 Defaults to @samp{disabled}.
27134 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
27135 Flag which, when set to @code{#t}, hides the repository from the
27138 Defaults to @samp{#f}.
27142 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
27143 Flag which, when set to @samp{#t}, ignores the repository.
27145 Defaults to @samp{#f}.
27149 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
27150 URL which specifies the source of an image which will be used as a logo
27151 on this repo’s pages.
27153 Defaults to @samp{""}.
27157 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
27158 URL loaded when clicking on the cgit logo image.
27160 Defaults to @samp{""}.
27164 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
27165 Override the default @code{owner-filter}.
27167 Defaults to @samp{""}.
27171 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
27172 Text which will be used as the formatstring for a hyperlink when a
27173 submodule is printed in a directory listing. The arguments for the
27174 formatstring are the path and SHA1 of the submodule commit.
27176 Defaults to @samp{""}.
27180 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
27181 Text which will be used as the formatstring for a hyperlink when a
27182 submodule with the specified subdirectory path is printed in a directory
27185 Defaults to @samp{()}.
27189 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
27190 Override the default maximum statistics period.
27192 Defaults to @samp{""}.
27196 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
27197 The value to show as repository name.
27199 Defaults to @samp{""}.
27203 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
27204 A value used to identify the owner of the repository.
27206 Defaults to @samp{""}.
27210 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
27211 An absolute path to the repository directory.
27213 Defaults to @samp{""}.
27217 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
27218 A path (relative to repo) which specifies a file to include verbatim as
27219 the ``About'' page for this repo.
27221 Defaults to @samp{""}.
27225 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
27226 The name of the current repository section - all repositories defined
27227 after this option will inherit the current section name.
27229 Defaults to @samp{""}.
27233 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
27234 Extra options will be appended to cgitrc file.
27236 Defaults to @samp{()}.
27242 @deftypevr {@code{cgit-configuration} parameter} list extra-options
27243 Extra options will be appended to cgitrc file.
27245 Defaults to @samp{()}.
27250 @c %end of fragment
27252 However, it could be that you just want to get a @code{cgitrc} up and
27253 running. In that case, you can pass an @code{opaque-cgit-configuration}
27254 as a record to @code{cgit-service-type}. As its name indicates, an
27255 opaque configuration does not have easy reflective capabilities.
27257 Available @code{opaque-cgit-configuration} fields are:
27259 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
27263 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
27264 The contents of the @code{cgitrc}, as a string.
27267 For example, if your @code{cgitrc} is just the empty string, you
27268 could instantiate a cgit service like this:
27271 (service cgit-service-type
27272 (opaque-cgit-configuration
27276 @subsubheading Gitolite Service
27278 @cindex Gitolite service
27279 @cindex Git, hosting
27280 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
27281 repositories on a central server.
27283 Gitolite can handle multiple repositories and users, and supports flexible
27284 configuration of the permissions for the users on the repositories.
27286 The following example will configure Gitolite using the default @code{git}
27287 user, and the provided SSH public key.
27290 (service gitolite-service-type
27291 (gitolite-configuration
27292 (admin-pubkey (plain-file
27294 "ssh-rsa AAAA... guix@@example.com"))))
27297 Gitolite is configured through a special admin repository which you can clone,
27298 for example, if you setup Gitolite on @code{example.com}, you would run the
27299 following command to clone the admin repository.
27302 git clone git@@example.com:gitolite-admin
27305 When the Gitolite service is activated, the provided @code{admin-pubkey} will
27306 be inserted in to the @file{keydir} directory in the gitolite-admin
27307 repository. If this results in a change in the repository, it will be
27308 committed using the message ``gitolite setup by GNU Guix''.
27310 @deftp {Data Type} gitolite-configuration
27311 Data type representing the configuration for @code{gitolite-service-type}.
27314 @item @code{package} (default: @var{gitolite})
27315 Gitolite package to use.
27317 @item @code{user} (default: @var{git})
27318 User to use for Gitolite. This will be user that you use when accessing
27321 @item @code{group} (default: @var{git})
27322 Group to use for Gitolite.
27324 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
27325 Directory in which to store the Gitolite configuration and repositories.
27327 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
27328 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
27329 representing the configuration for Gitolite.
27331 @item @code{admin-pubkey} (default: @var{#f})
27332 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
27333 setup Gitolite. This will be inserted in to the @file{keydir} directory
27334 within the gitolite-admin repository.
27336 To specify the SSH key as a string, use the @code{plain-file} function.
27339 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
27345 @deftp {Data Type} gitolite-rc-file
27346 Data type representing the Gitolite RC file.
27349 @item @code{umask} (default: @code{#o0077})
27350 This controls the permissions Gitolite sets on the repositories and their
27353 A value like @code{#o0027} will give read access to the group used by Gitolite
27354 (by default: @code{git}). This is necessary when using Gitolite with software
27355 like cgit or gitweb.
27357 @item @code{git-config-keys} (default: @code{""})
27358 Gitolite allows you to set git config values using the @samp{config} keyword. This
27359 setting allows control over the config keys to accept.
27361 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
27362 Set the role names allowed to be used by users running the perms command.
27364 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
27365 This setting controls the commands and features to enable within Gitolite.
27371 @node Game Services
27372 @subsection Game Services
27374 @subsubheading The Battle for Wesnoth Service
27376 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
27377 based tactical strategy game, with several single player campaigns, and
27378 multiplayer games (both networked and local).
27380 @defvar {Scheme Variable} wesnothd-service-type
27381 Service type for the wesnothd service. Its value must be a
27382 @code{wesnothd-configuration} object. To run wesnothd in the default
27383 configuration, instantiate it as:
27386 (service wesnothd-service-type)
27390 @deftp {Data Type} wesnothd-configuration
27391 Data type representing the configuration of @command{wesnothd}.
27394 @item @code{package} (default: @code{wesnoth-server})
27395 The wesnoth server package to use.
27397 @item @code{port} (default: @code{15000})
27398 The port to bind the server to.
27403 @node PAM Mount Service
27404 @subsection PAM Mount Service
27407 The @code{(gnu services pam-mount)} module provides a service allowing
27408 users to mount volumes when they log in. It should be able to mount any
27409 volume format supported by the system.
27411 @defvar {Scheme Variable} pam-mount-service-type
27412 Service type for PAM Mount support.
27415 @deftp {Data Type} pam-mount-configuration
27416 Data type representing the configuration of PAM Mount.
27418 It takes the following parameters:
27422 The configuration rules that will be used to generate
27423 @file{/etc/security/pam_mount.conf.xml}.
27425 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
27426 Guile Reference Manual}), and the the default ones don't mount anything
27427 for anyone at login:
27430 `((debug (@@ (enable "0")))
27431 (mntoptions (@@ (allow ,(string-join
27432 '("nosuid" "nodev" "loop"
27433 "encryption" "fsck" "nonempty"
27434 "allow_root" "allow_other")
27436 (mntoptions (@@ (require "nosuid,nodev")))
27437 (logout (@@ (wait "0")
27441 (mkmountpoint (@@ (enable "1")
27445 Some @code{volume} elements must be added to automatically mount volumes
27446 at login. Here's an example allowing the user @code{alice} to mount her
27447 encrypted @env{HOME} directory and allowing the user @code{bob} to mount
27448 the partition where he stores his data:
27451 (define pam-mount-rules
27452 `((debug (@@ (enable "0")))
27453 (volume (@@ (user "alice")
27456 (mountpoint "/home/alice")))
27457 (volume (@@ (user "bob")
27460 (mountpoint "/home/bob/data")
27461 (options "defaults,autodefrag,compress")))
27462 (mntoptions (@@ (allow ,(string-join
27463 '("nosuid" "nodev" "loop"
27464 "encryption" "fsck" "nonempty"
27465 "allow_root" "allow_other")
27467 (mntoptions (@@ (require "nosuid,nodev")))
27468 (logout (@@ (wait "0")
27472 (mkmountpoint (@@ (enable "1")
27473 (remove "true")))))
27475 (service pam-mount-service-type
27476 (pam-mount-configuration
27477 (rules pam-mount-rules)))
27480 The complete list of possible options can be found in the man page for
27481 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
27486 @node Guix Services
27487 @subsection Guix Services
27489 @subsubheading Guix Data Service
27490 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
27491 and provides data about GNU Guix. This includes information about
27492 packages, derivations and lint warnings.
27494 The data is stored in a PostgreSQL database, and available through a web
27497 @defvar {Scheme Variable} guix-data-service-type
27498 Service type for the Guix Data Service. Its value must be a
27499 @code{guix-data-service-configuration} object. The service optionally
27500 extends the getmail service, as the guix-commits mailing list is used to
27501 find out about changes in the Guix git repository.
27504 @deftp {Data Type} guix-data-service-configuration
27505 Data type representing the configuration of the Guix Data Service.
27508 @item @code{package} (default: @code{guix-data-service})
27509 The Guix Data Service package to use.
27511 @item @code{user} (default: @code{"guix-data-service"})
27512 The system user to run the service as.
27514 @item @code{group} (default: @code{"guix-data-service"})
27515 The system group to run the service as.
27517 @item @code{port} (default: @code{8765})
27518 The port to bind the web service to.
27520 @item @code{host} (default: @code{"127.0.0.1"})
27521 The host to bind the web service to.
27523 @item @code{getmail-idle-mailboxes} (default: @code{#f})
27524 If set, this is the list of mailboxes that the getmail service will be
27525 configured to listen to.
27527 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
27528 If set, this is the @code{getmail-retriever-configuration} object with
27529 which to configure getmail to fetch mail from the guix-commits mailing
27532 @item @code{extra-options} (default: @var{'()})
27533 Extra command line options for @code{guix-data-service}.
27535 @item @code{extra-process-jobs-options} (default: @var{'()})
27536 Extra command line options for @code{guix-data-service-process-jobs}.
27541 @node Linux Services
27542 @subsection Linux Services
27545 @cindex out of memory killer
27547 @cindex early out of memory daemon
27548 @subsubheading Early OOM Service
27550 @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
27551 Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
27552 space and provides a more responsive and configurable alternative to the
27553 in-kernel OOM killer. It is useful to prevent the system from becoming
27554 unresponsive when it runs out of memory.
27556 @deffn {Scheme Variable} earlyoom-service-type
27557 The service type for running @command{earlyoom}, the Early OOM daemon.
27558 Its value must be a @code{earlyoom-configuration} object, described
27559 below. The service can be instantiated in its default configuration
27563 (service earlyoom-service-type)
27567 @deftp {Data Type} earlyoom-configuration
27568 This is the configuration record for the @code{earlyoom-service-type}.
27571 @item @code{earlyoom} (default: @var{earlyoom})
27572 The Earlyoom package to use.
27574 @item @code{minimum-available-memory} (default: @code{10})
27575 The threshold for the minimum @emph{available} memory, in percentages.
27577 @item @code{minimum-free-swap} (default: @code{10})
27578 The threshold for the minimum free swap memory, in percentages.
27580 @item @code{prefer-regexp} (default: @code{#f})
27581 A regular expression (as a string) to match the names of the processes
27582 that should be preferably killed.
27584 @item @code{avoid-regexp} (default: @code{#f})
27585 A regular expression (as a string) to match the names of the processes
27586 that should @emph{not} be killed.
27588 @item @code{memory-report-interval} (default: @code{0})
27589 The interval in seconds at which a memory report is printed. It is
27590 disabled by default.
27592 @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
27593 A boolean indicating whether the positive adjustments set in
27594 @file{/proc/*/oom_score_adj}.
27596 @item @code{show-debug-messages?} (default: @code{#f})
27597 A boolean indicating whether debug messages should be printed. The logs
27598 are saved at @file{/var/log/earlyoom.log}.
27600 @item @code{send-notification-command} (default: @code{#f})
27601 This can be used to provide a custom command used for sending
27607 @cindex kernel module loader
27608 @subsubheading Kernel Module Loader Service
27610 The kernel module loader service allows one to load loadable kernel
27611 modules at boot. This is especially useful for modules that don't
27612 autoload and need to be manually loaded, as it's the case with
27615 @deffn {Scheme Variable} kernel-module-loader-service-type
27616 The service type for loading loadable kernel modules at boot with
27617 @command{modprobe}. Its value must be a list of strings representing
27618 module names. For example loading the drivers provided by
27619 @code{ddcci-driver-linux}, in debugging mode by passing some module
27620 parameters, can be done as follow:
27623 (use-modules (gnu) (gnu services))
27624 (use-package-modules linux)
27625 (use-service-modules linux)
27627 (define ddcci-config
27628 (plain-file "ddcci.conf"
27629 "options ddcci dyndbg delay=120"))
27633 (services (cons* (service kernel-module-loader-service-type
27634 '("ddcci" "ddcci_backlight"))
27635 (simple-service 'ddcci-config etc-service-type
27636 (list `("modprobe.d/ddcci.conf"
27639 (kernel-loadable-modules (list ddcci-driver-linux)))
27644 @cindex compressed swap
27645 @cindex Compressed RAM-based block devices
27646 @subsubheading Zram Device Service
27648 The Zram device service provides a compressed swap device in system
27649 memory. The Linux Kernel documentation has more information about
27650 @uref{https://www.kernel.org/doc/html/latest/admin-guide/blockdev/zram.html,zram}
27653 @deffn {Scheme Variable} zram-device-service-type
27654 This service creates the zram block device, formats it as swap and
27655 enables it as a swap device. The service's value is a
27656 @code{zram-device-configuration} record.
27658 @deftp {Data Type} zram-device-configuration
27659 This is the data type representing the configuration for the zram-device
27663 @item @code{size} (default @var{"1G"})
27664 This is the amount of space you wish to provide for the zram device. It
27665 accepts a string and can be a number of bytes or use a suffix, eg.:
27666 @var{"512M"} or @var{1024000}.
27667 @item @code{compression-algorithm} (default @var{'lzo})
27668 This is the compression algorithm you wish to use. It is difficult to
27669 list all the possible compression options, but common ones supported by
27670 Guix's Linux Libre Kernel include @var{'lzo}, @var{'lz4} and @var{'zstd}.
27671 @item @code{memory-limit} (default @var{0})
27672 This is the maximum amount of memory which the zram device can use.
27673 Setting it to '0' disables the limit. While it is generally expected
27674 that compression will be 2:1, it is possible that uncompressable data
27675 can be written to swap and this is a method to limit how much memory can
27676 be used. It accepts a string and can be a number of bytes or use a
27677 suffix, eg.: @var{"2G"}.
27678 @item @code{priority} (default @var{-1})
27679 This is the priority of the swap device created from the zram device.
27680 @code{swapon} accepts values between -1 and 32767, with higher values
27681 indicating higher priority. Higher priority swap will generally be used
27688 @node Hurd Services
27689 @subsection Hurd Services
27691 @defvr {Scheme Variable} hurd-console-service-type
27692 This service starts the fancy @code{VGA} console client on the Hurd.
27694 The service's value is a @code{hurd-console-configuration} record.
27697 @deftp {Data Type} hurd-console-configuration
27698 This is the data type representing the configuration for the
27699 hurd-console-service.
27702 @item @code{hurd} (default: @var{hurd})
27703 The Hurd package to use.
27707 @defvr {Scheme Variable} hurd-getty-service-type
27708 This service starts a tty using the Hurd @code{getty} program.
27710 The service's value is a @code{hurd-getty-configuration} record.
27713 @deftp {Data Type} hurd-getty-configuration
27714 This is the data type representing the configuration for the
27715 hurd-getty-service.
27718 @item @code{hurd} (default: @var{hurd})
27719 The Hurd package to use.
27722 The name of the console this Getty runs on---e.g., @code{"tty1"}.
27724 @item @code{baud-rate} (default: @code{38400})
27725 An integer specifying the baud rate of the tty.
27730 @node Miscellaneous Services
27731 @subsection Miscellaneous Services
27733 @cindex fingerprint
27734 @subsubheading Fingerprint Service
27736 The @code{(gnu services authentication)} module provides a DBus service to
27737 read and identify fingerprints via a fingerprint sensor.
27739 @defvr {Scheme Variable} fprintd-service-type
27740 The service type for @command{fprintd}, which provides the fingerprint
27741 reading capability.
27744 (service fprintd-service-type)
27749 @subsubheading System Control Service
27751 The @code{(gnu services sysctl)} provides a service to configure kernel
27752 parameters at boot.
27754 @defvr {Scheme Variable} sysctl-service-type
27755 The service type for @command{sysctl}, which modifies kernel parameters
27756 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
27760 (service sysctl-service-type
27761 (sysctl-configuration
27762 (settings '(("net.ipv4.ip_forward" . "1")))))
27766 @deftp {Data Type} sysctl-configuration
27767 The data type representing the configuration of @command{sysctl}.
27770 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
27771 The @command{sysctl} executable to use.
27773 @item @code{settings} (default: @code{'()})
27774 An association list specifies kernel parameters and their values.
27779 @subsubheading PC/SC Smart Card Daemon Service
27781 The @code{(gnu services security-token)} module provides the following service
27782 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
27783 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
27784 manager that coordinates communications with smart card readers, smart cards
27785 and cryptographic tokens that are connected to the system.
27787 @defvr {Scheme Variable} pcscd-service-type
27788 Service type for the @command{pcscd} service. Its value must be a
27789 @code{pcscd-configuration} object. To run pcscd in the default
27790 configuration, instantiate it as:
27793 (service pcscd-service-type)
27797 @deftp {Data Type} pcscd-configuration
27798 The data type representing the configuration of @command{pcscd}.
27801 @item @code{pcsc-lite} (default: @code{pcsc-lite})
27802 The pcsc-lite package that provides pcscd.
27803 @item @code{usb-drivers} (default: @code{(list ccid)})
27804 List of packages that provide USB drivers to pcscd. Drivers are expected to be
27805 under @file{pcsc/drivers} in the store directory of the package.
27810 @subsubheading Lirc Service
27812 The @code{(gnu services lirc)} module provides the following service.
27814 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
27815 [#:device #f] [#:driver #f] [#:config-file #f] @
27816 [#:extra-options '()]
27817 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
27818 decodes infrared signals from remote controls.
27820 Optionally, @var{device}, @var{driver} and @var{config-file}
27821 (configuration file name) may be specified. See @command{lircd} manual
27824 Finally, @var{extra-options} is a list of additional command-line options
27825 passed to @command{lircd}.
27829 @subsubheading Spice Service
27831 The @code{(gnu services spice)} module provides the following service.
27833 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
27834 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
27835 that enables sharing the clipboard with a vm and setting the guest display
27836 resolution when the graphical console window resizes.
27839 @cindex inputattach
27840 @subsubheading inputattach Service
27842 @cindex tablet input, for Xorg
27843 @cindex touchscreen input, for Xorg
27844 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
27845 use input devices such as Wacom tablets, touchscreens, or joysticks with the
27846 Xorg display server.
27848 @deffn {Scheme Variable} inputattach-service-type
27849 Type of a service that runs @command{inputattach} on a device and
27850 dispatches events from it.
27853 @deftp {Data Type} inputattach-configuration
27855 @item @code{device-type} (default: @code{"wacom"})
27856 The type of device to connect to. Run @command{inputattach --help}, from the
27857 @code{inputattach} package, to see the list of supported device types.
27859 @item @code{device} (default: @code{"/dev/ttyS0"})
27860 The device file to connect to the device.
27862 @item @code{baud-rate} (default: @code{#f})
27863 Baud rate to use for the serial connection.
27864 Should be a number or @code{#f}.
27866 @item @code{log-file} (default: @code{#f})
27867 If true, this must be the name of a file to log messages to.
27871 @subsubheading Dictionary Service
27873 The @code{(gnu services dict)} module provides the following service:
27875 @defvr {Scheme Variable} dicod-service-type
27876 This is the type of the service that runs the @command{dicod} daemon, an
27877 implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
27880 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
27881 Return a service that runs the @command{dicod} daemon, an implementation
27882 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
27884 The optional @var{config} argument specifies the configuration for
27885 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
27886 default it serves the GNU Collaborative International Dictionary of English.
27888 You can add @command{open localhost} to your @file{~/.dico} file to make
27889 @code{localhost} the default server for @command{dico} client
27890 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
27893 @deftp {Data Type} dicod-configuration
27894 Data type representing the configuration of dicod.
27897 @item @code{dico} (default: @var{dico})
27898 Package object of the GNU Dico dictionary server.
27900 @item @code{interfaces} (default: @var{'("localhost")})
27901 This is the list of IP addresses and ports and possibly socket file
27902 names to listen to (@pxref{Server Settings, @code{listen} directive,,
27903 dico, GNU Dico Manual}).
27905 @item @code{handlers} (default: @var{'()})
27906 List of @code{<dicod-handler>} objects denoting handlers (module instances).
27908 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
27909 List of @code{<dicod-database>} objects denoting dictionaries to be served.
27913 @deftp {Data Type} dicod-handler
27914 Data type representing a dictionary handler (module instance).
27918 Name of the handler (module instance).
27920 @item @code{module} (default: @var{#f})
27921 Name of the dicod module of the handler (instance). If it is @code{#f},
27922 the module has the same name as the handler.
27923 (@pxref{Modules,,, dico, GNU Dico Manual}).
27925 @item @code{options}
27926 List of strings or gexps representing the arguments for the module handler
27930 @deftp {Data Type} dicod-database
27931 Data type representing a dictionary database.
27935 Name of the database, will be used in DICT commands.
27937 @item @code{handler}
27938 Name of the dicod handler (module instance) used by this database
27939 (@pxref{Handlers,,, dico, GNU Dico Manual}).
27941 @item @code{complex?} (default: @var{#f})
27942 Whether the database configuration complex. The complex configuration
27943 will need a corresponding @code{<dicod-handler>} object, otherwise not.
27945 @item @code{options}
27946 List of strings or gexps representing the arguments for the database
27947 (@pxref{Databases,,, dico, GNU Dico Manual}).
27951 @defvr {Scheme Variable} %dicod-database:gcide
27952 A @code{<dicod-database>} object serving the GNU Collaborative International
27953 Dictionary of English using the @code{gcide} package.
27956 The following is an example @code{dicod-service} configuration.
27959 (dicod-service #:config
27960 (dicod-configuration
27961 (handlers (list (dicod-handler
27965 (list #~(string-append "dbdir=" #$wordnet))))))
27966 (databases (list (dicod-database
27969 (handler "wordnet")
27970 (options '("database=wn")))
27971 %dicod-database:gcide))))
27975 @subsubheading Docker Service
27977 The @code{(gnu services docker)} module provides the following services.
27979 @defvr {Scheme Variable} docker-service-type
27981 This is the type of the service that runs @url{https://www.docker.com,Docker},
27982 a daemon that can execute application bundles (sometimes referred to as
27983 ``containers'') in isolated environments.
27987 @deftp {Data Type} docker-configuration
27988 This is the data type representing the configuration of Docker and Containerd.
27992 @item @code{package} (default: @code{docker})
27993 The Docker daemon package to use.
27995 @item @code{package} (default: @code{docker-cli})
27996 The Docker client package to use.
27998 @item @code{containerd} (default: @var{containerd})
27999 The Containerd package to use.
28001 @item @code{proxy} (default @var{docker-libnetwork-cmd-proxy})
28002 The Docker user-land networking proxy package to use.
28004 @item @code{enable-proxy?} (default @code{#t})
28005 Enable or disable the use of the Docker user-land networking proxy.
28007 @item @code{debug?} (default @code{#f})
28008 Enable or disable debug output.
28010 @item @code{enable-iptables?} (default @code{#t})
28011 Enable or disable the addition of iptables rules.
28017 @subsubheading Auditd Service
28019 The @code{(gnu services auditd)} module provides the following service.
28021 @defvr {Scheme Variable} auditd-service-type
28023 This is the type of the service that runs
28024 @url{https://people.redhat.com/sgrubb/audit/,auditd},
28025 a daemon that tracks security-relevant information on your system.
28027 Examples of things that can be tracked:
28037 Failed login attempts
28044 @command{auditctl} from the @code{audit} package can be used in order
28045 to add or remove events to be tracked (until the next reboot).
28046 In order to permanently track events, put the command line arguments
28047 of auditctl into a file called @code{audit.rules} in the configuration
28048 directory (see below).
28049 @command{aureport} from the @code{audit} package can be used in order
28050 to view a report of all recorded events.
28051 The audit daemon by default logs into the file
28052 @file{/var/log/audit.log}.
28056 @deftp {Data Type} auditd-configuration
28057 This is the data type representing the configuration of auditd.
28061 @item @code{audit} (default: @code{audit})
28062 The audit package to use.
28064 @item @code{configuration-directory} (default: @code{%default-auditd-configuration-directory})
28065 The directory containing the configuration file for the audit package, which
28066 must be named @code{auditd.conf}, and optionally some audit rules to
28067 instantiate on startup.
28072 @defvr {Scheme Variable} singularity-service-type
28073 This is the type of the service that allows you to run
28074 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
28075 create and run application bundles (aka. ``containers''). The value for this
28076 service is the Singularity package to use.
28078 The service does not install a daemon; instead, it installs helper programs as
28079 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
28080 @command{singularity run} and similar commands.
28084 @subsubheading R-Shiny service
28086 The @code{(gnu services science)} module provides the following service.
28088 @defvr {Scheme Variable} rshiny-service-type
28090 This is a type of service which is used to run a webapp created with
28091 @code{r-shiny}. This service sets the @code{R_LIBS_USER} environment
28092 variable and runs the provided script to call @code{runApp}.
28094 @deftp {Data Type} rshiny-configuration
28095 This is the data type representing the configuration of rshiny.
28099 @item @code{package} (default: @code{r-shiny})
28100 The package to use.
28102 @item @code{binary} (defaunlt @code{"rshiny"})
28103 The name of the binary or shell script located at @code{package/bin/} to
28104 run when the service is run.
28106 The common way to create this file is as follows:
28110 (let* ((out (assoc-ref %outputs "out"))
28111 (targetdir (string-append out "/share/" ,name))
28112 (app (string-append out "/bin/" ,name))
28113 (Rbin (string-append (assoc-ref %build-inputs "r-min")
28116 (mkdir-p (string-append out "/bin"))
28117 (call-with-output-file app
28123 runApp(launch.browser=0, port=4202)~%\n"
28132 @subsubheading Nix service
28134 The @code{(gnu services nix)} module provides the following service.
28136 @defvr {Scheme Variable} nix-service-type
28138 This is the type of the service that runs build daemon of the
28139 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
28143 (use-modules (gnu))
28144 (use-service-modules nix)
28145 (use-package-modules package-management)
28149 (packages (append (list nix)
28152 (services (append (list (service nix-service-type))
28156 After @command{guix system reconfigure} configure Nix for your user:
28159 @item Add a Nix channel and update it. See
28160 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
28162 @item Create a symlink to your profile and activate Nix profile:
28166 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
28167 $ source /run/current-system/profile/etc/profile.d/nix.sh
28172 @deftp {Data Type} nix-configuration
28173 This data type represents the configuration of the Nix daemon.
28176 @item @code{nix} (default: @code{nix})
28177 The Nix package to use.
28179 @item @code{sandbox} (default: @code{#t})
28180 Specifies whether builds are sandboxed by default.
28182 @item @code{build-sandbox-items} (default: @code{'()})
28183 This is a list of strings or objects appended to the
28184 @code{build-sandbox-items} field of the configuration file.
28186 @item @code{extra-config} (default: @code{'()})
28187 This is a list of strings or objects appended to the configuration file.
28188 It is used to pass extra text to be added verbatim to the configuration
28191 @item @code{extra-options} (default: @code{'()})
28192 Extra command line options for @code{nix-service-type}.
28196 @node Setuid Programs
28197 @section Setuid Programs
28199 @cindex setuid programs
28200 Some programs need to run with ``root'' privileges, even when they are
28201 launched by unprivileged users. A notorious example is the
28202 @command{passwd} program, which users can run to change their
28203 password, and which needs to access the @file{/etc/passwd} and
28204 @file{/etc/shadow} files---something normally restricted to root, for
28205 obvious security reasons. To address that, these executables are
28206 @dfn{setuid-root}, meaning that they always run with root privileges
28207 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
28208 for more info about the setuid mechanism).
28210 The store itself @emph{cannot} contain setuid programs: that would be a
28211 security issue since any user on the system can write derivations that
28212 populate the store (@pxref{The Store}). Thus, a different mechanism is
28213 used: instead of changing the setuid bit directly on files that are in
28214 the store, we let the system administrator @emph{declare} which programs
28215 should be setuid root.
28217 The @code{setuid-programs} field of an @code{operating-system}
28218 declaration contains a list of G-expressions denoting the names of
28219 programs to be setuid-root (@pxref{Using the Configuration System}).
28220 For instance, the @command{passwd} program, which is part of the Shadow
28221 package, can be designated by this G-expression (@pxref{G-Expressions}):
28224 #~(string-append #$shadow "/bin/passwd")
28227 A default set of setuid programs is defined by the
28228 @code{%setuid-programs} variable of the @code{(gnu system)} module.
28230 @defvr {Scheme Variable} %setuid-programs
28231 A list of G-expressions denoting common programs that are setuid-root.
28233 The list includes commands such as @command{passwd}, @command{ping},
28234 @command{su}, and @command{sudo}.
28237 Under the hood, the actual setuid programs are created in the
28238 @file{/run/setuid-programs} directory at system activation time. The
28239 files in this directory refer to the ``real'' binaries, which are in the
28242 @node X.509 Certificates
28243 @section X.509 Certificates
28245 @cindex HTTPS, certificates
28246 @cindex X.509 certificates
28248 Web servers available over HTTPS (that is, HTTP over the transport-layer
28249 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
28250 that the client can then use to @emph{authenticate} the server. To do
28251 that, clients verify that the server's certificate is signed by a
28252 so-called @dfn{certificate authority} (CA). But to verify the CA's
28253 signature, clients must have first acquired the CA's certificate.
28255 Web browsers such as GNU@tie{}IceCat include their own set of CA
28256 certificates, such that they are able to verify CA signatures
28259 However, most other programs that can talk HTTPS---@command{wget},
28260 @command{git}, @command{w3m}, etc.---need to be told where CA
28261 certificates can be found.
28263 @cindex @code{nss-certs}
28264 In Guix, this is done by adding a package that provides certificates
28265 to the @code{packages} field of the @code{operating-system} declaration
28266 (@pxref{operating-system Reference}). Guix includes one such package,
28267 @code{nss-certs}, which is a set of CA certificates provided as part of
28268 Mozilla's Network Security Services.
28270 Note that it is @emph{not} part of @code{%base-packages}, so you need to
28271 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
28272 most applications and libraries look for certificates by default, points
28273 to the certificates installed globally.
28275 Unprivileged users, including users of Guix on a foreign distro,
28276 can also install their own certificate package in
28277 their profile. A number of environment variables need to be defined so
28278 that applications and libraries know where to find them. Namely, the
28279 OpenSSL library honors the @env{SSL_CERT_DIR} and @env{SSL_CERT_FILE}
28280 variables. Some applications add their own environment variables; for
28281 instance, the Git version control system honors the certificate bundle
28282 pointed to by the @env{GIT_SSL_CAINFO} environment variable. Thus, you
28283 would typically run something like:
28286 guix install nss-certs
28287 export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
28288 export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
28289 export GIT_SSL_CAINFO="$SSL_CERT_FILE"
28292 As another example, R requires the @env{CURL_CA_BUNDLE} environment
28293 variable to point to a certificate bundle, so you would have to run
28294 something like this:
28297 guix install nss-certs
28298 export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
28301 For other applications you may want to look up the required environment
28302 variable in the relevant documentation.
28305 @node Name Service Switch
28306 @section Name Service Switch
28308 @cindex name service switch
28310 The @code{(gnu system nss)} module provides bindings to the
28311 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
28312 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
28313 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
28314 extended with new ``name'' lookup methods for system databases, which
28315 includes host names, service names, user accounts, and more (@pxref{Name
28316 Service Switch, System Databases and Name Service Switch,, libc, The GNU
28317 C Library Reference Manual}).
28319 The NSS configuration specifies, for each system database, which lookup
28320 method is to be used, and how the various methods are chained
28321 together---for instance, under which circumstances NSS should try the
28322 next method in the list. The NSS configuration is given in the
28323 @code{name-service-switch} field of @code{operating-system} declarations
28324 (@pxref{operating-system Reference, @code{name-service-switch}}).
28327 @cindex .local, host name lookup
28328 As an example, the declaration below configures the NSS to use the
28329 @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
28330 back-end}, which supports host name lookups over multicast DNS (mDNS)
28331 for host names ending in @code{.local}:
28334 (name-service-switch
28335 (hosts (list %files ;first, check /etc/hosts
28337 ;; If the above did not succeed, try
28338 ;; with 'mdns_minimal'.
28340 (name "mdns_minimal")
28342 ;; 'mdns_minimal' is authoritative for
28343 ;; '.local'. When it returns "not found",
28344 ;; no need to try the next methods.
28345 (reaction (lookup-specification
28346 (not-found => return))))
28348 ;; Then fall back to DNS.
28352 ;; Finally, try with the "full" 'mdns'.
28357 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
28358 contains this configuration, so you will not have to type it if all you
28359 want is to have @code{.local} host lookup working.
28361 Note that, in this case, in addition to setting the
28362 @code{name-service-switch} of the @code{operating-system} declaration,
28363 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
28364 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
28365 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
28366 to the name service cache daemon (@pxref{Base Services,
28367 @code{nscd-service}}).
28369 For convenience, the following variables provide typical NSS
28372 @defvr {Scheme Variable} %default-nss
28373 This is the default name service switch configuration, a
28374 @code{name-service-switch} object.
28377 @defvr {Scheme Variable} %mdns-host-lookup-nss
28378 This is the name service switch configuration with support for host name
28379 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
28382 The reference for name service switch configuration is given below. It
28383 is a direct mapping of the configuration file format of the C library , so
28384 please refer to the C library manual for more information (@pxref{NSS
28385 Configuration File,,, libc, The GNU C Library Reference Manual}).
28386 Compared to the configuration file format of libc NSS, it has the advantage
28387 not only of adding this warm parenthetic feel that we like, but also
28388 static checks: you will know about syntax errors and typos as soon as you
28389 run @command{guix system}.
28391 @deftp {Data Type} name-service-switch
28393 This is the data type representation the configuration of libc's name
28394 service switch (NSS). Each field below represents one of the supported
28411 The system databases handled by the NSS. Each of these fields must be a
28412 list of @code{<name-service>} objects (see below).
28416 @deftp {Data Type} name-service
28418 This is the data type representing an actual name service and the
28419 associated lookup action.
28423 A string denoting the name service (@pxref{Services in the NSS
28424 configuration,,, libc, The GNU C Library Reference Manual}).
28426 Note that name services listed here must be visible to nscd. This is
28427 achieved by passing the @code{#:name-services} argument to
28428 @code{nscd-service} the list of packages providing the needed name
28429 services (@pxref{Base Services, @code{nscd-service}}).
28432 An action specified using the @code{lookup-specification} macro
28433 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
28434 Reference Manual}). For example:
28437 (lookup-specification (unavailable => continue)
28438 (success => return))
28443 @node Initial RAM Disk
28444 @section Initial RAM Disk
28447 @cindex initial RAM disk
28448 For bootstrapping purposes, the Linux-Libre kernel is passed an
28449 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
28450 root file system as well as an initialization script. The latter is
28451 responsible for mounting the real root file system, and for loading any
28452 kernel modules that may be needed to achieve that.
28454 The @code{initrd-modules} field of an @code{operating-system}
28455 declaration allows you to specify Linux-libre kernel modules that must
28456 be available in the initrd. In particular, this is where you would list
28457 modules needed to actually drive the hard disk where your root partition
28458 is---although the default value of @code{initrd-modules} should cover
28459 most use cases. For example, assuming you need the @code{megaraid_sas}
28460 module in addition to the default modules to be able to access your root
28461 file system, you would write:
28466 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
28469 @defvr {Scheme Variable} %base-initrd-modules
28470 This is the list of kernel modules included in the initrd by default.
28473 Furthermore, if you need lower-level customization, the @code{initrd}
28474 field of an @code{operating-system} declaration allows
28475 you to specify which initrd you would like to use. The @code{(gnu
28476 system linux-initrd)} module provides three ways to build an initrd: the
28477 high-level @code{base-initrd} procedure and the low-level
28478 @code{raw-initrd} and @code{expression->initrd} procedures.
28480 The @code{base-initrd} procedure is intended to cover most common uses.
28481 For example, if you want to add a bunch of kernel modules to be loaded
28482 at boot time, you can define the @code{initrd} field of the operating
28483 system declaration like this:
28486 (initrd (lambda (file-systems . rest)
28487 ;; Create a standard initrd but set up networking
28488 ;; with the parameters QEMU expects by default.
28489 (apply base-initrd file-systems
28490 #:qemu-networking? #t
28494 The @code{base-initrd} procedure also handles common use cases that
28495 involves using the system as a QEMU guest, or as a ``live'' system with
28496 volatile root file system.
28498 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
28499 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
28500 such as trying to guess which kernel modules and packages should be included
28501 to the initrd. An example use of @code{raw-initrd} is when a user has
28502 a custom Linux kernel configuration and default kernel modules included by
28503 @code{base-initrd} are not available.
28505 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
28506 honors several options passed on the Linux kernel command line
28507 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
28508 @code{-append} option of QEMU), notably:
28511 @item --load=@var{boot}
28512 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
28513 program, once it has mounted the root file system.
28515 Guix uses this option to yield control to a boot program that runs the
28516 service activation programs and then spawns the GNU@tie{}Shepherd, the
28517 initialization system.
28519 @item --root=@var{root}
28520 Mount @var{root} as the root file system. @var{root} can be a device
28521 name like @code{/dev/sda1}, a file system label, or a file system UUID.
28522 When unspecified, the device name from the root file system of the
28523 operating system declaration is used.
28525 @item --system=@var{system}
28526 Have @file{/run/booted-system} and @file{/run/current-system} point to
28529 @item modprobe.blacklist=@var{modules}@dots{}
28530 @cindex module, black-listing
28531 @cindex black list, of kernel modules
28532 Instruct the initial RAM disk as well as the @command{modprobe} command
28533 (from the kmod package) to refuse to load @var{modules}. @var{modules}
28534 must be a comma-separated list of module names---e.g.,
28535 @code{usbkbd,9pnet}.
28538 Start a read-eval-print loop (REPL) from the initial RAM disk before it
28539 tries to load kernel modules and to mount the root file system. Our
28540 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
28541 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
28542 Manual}, for more information on Guile's REPL.
28546 Now that you know all the features that initial RAM disks produced by
28547 @code{base-initrd} and @code{raw-initrd} provide,
28548 here is how to use it and customize it further.
28551 @cindex initial RAM disk
28552 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
28553 [#:linux-modules '()] [#:mapped-devices '()] @
28554 [#:keyboard-layout #f] @
28555 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
28556 Return a derivation that builds a raw initrd. @var{file-systems} is
28557 a list of file systems to be mounted by the initrd, possibly in addition to
28558 the root file system specified on the kernel command line via @option{--root}.
28559 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
28560 @var{mapped-devices} is a list of device mappings to realize before
28561 @var{file-systems} are mounted (@pxref{Mapped Devices}).
28562 @var{helper-packages} is a list of packages to be copied in the initrd. It may
28563 include @code{e2fsck/static} or other packages needed by the initrd to check
28564 the root file system.
28566 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
28567 the desired console keyboard layout. This is done before @var{mapped-devices}
28568 are set up and before @var{file-systems} are mounted such that, should the
28569 user need to enter a passphrase or use the REPL, this happens using the
28570 intended keyboard layout.
28572 When @var{qemu-networking?} is true, set up networking with the standard QEMU
28573 parameters. When @var{virtio?} is true, load additional modules so that the
28574 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
28576 When @var{volatile-root?} is true, the root file system is writable but any changes
28580 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
28581 [#:mapped-devices '()] [#:keyboard-layout #f] @
28582 [#:qemu-networking? #f] [#:volatile-root? #f] @
28583 [#:linux-modules '()]
28584 Return as a file-like object a generic initrd, with kernel
28585 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
28586 mounted by the initrd, possibly in addition to the root file system specified
28587 on the kernel command line via @option{--root}. @var{mapped-devices} is a list of device
28588 mappings to realize before @var{file-systems} are mounted.
28590 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
28591 the desired console keyboard layout. This is done before @var{mapped-devices}
28592 are set up and before @var{file-systems} are mounted such that, should the
28593 user need to enter a passphrase or use the REPL, this happens using the
28594 intended keyboard layout.
28596 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
28598 The initrd is automatically populated with all the kernel modules necessary
28599 for @var{file-systems} and for the given options. Additional kernel
28600 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
28601 loaded at boot time in the order in which they appear.
28604 Needless to say, the initrds we produce and use embed a
28605 statically-linked Guile, and the initialization program is a Guile
28606 program. That gives a lot of flexibility. The
28607 @code{expression->initrd} procedure builds such an initrd, given the
28608 program to run in that initrd.
28610 @deffn {Scheme Procedure} expression->initrd @var{exp} @
28611 [#:guile %guile-3.0-static-stripped] [#:name "guile-initrd"]
28612 Return as a file-like object a Linux initrd (a gzipped cpio archive)
28613 containing @var{guile} and that evaluates @var{exp}, a G-expression,
28614 upon booting. All the derivations referenced by @var{exp} are
28615 automatically copied to the initrd.
28618 @node Bootloader Configuration
28619 @section Bootloader Configuration
28622 @cindex boot loader
28624 The operating system supports multiple bootloaders. The bootloader is
28625 configured using @code{bootloader-configuration} declaration. All the
28626 fields of this structure are bootloader agnostic except for one field,
28627 @code{bootloader} that indicates the bootloader to be configured and
28630 Some of the bootloaders do not honor every field of
28631 @code{bootloader-configuration}. For instance, the extlinux
28632 bootloader does not support themes and thus ignores the @code{theme}
28635 @deftp {Data Type} bootloader-configuration
28636 The type of a bootloader configuration declaration.
28640 @item @code{bootloader}
28641 @cindex EFI, bootloader
28642 @cindex UEFI, bootloader
28643 @cindex BIOS, bootloader
28644 The bootloader to use, as a @code{bootloader} object. For now
28645 @code{grub-bootloader}, @code{grub-efi-bootloader},
28646 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
28648 @vindex grub-efi-bootloader
28649 @code{grub-efi-bootloader} allows to boot on modern systems using the
28650 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
28651 use if the installation image contains a @file{/sys/firmware/efi} directory
28652 when you boot it on your system.
28654 @vindex grub-bootloader
28655 @code{grub-bootloader} allows you to boot in particular Intel-based machines
28656 in ``legacy'' BIOS mode.
28658 @cindex ARM, bootloaders
28659 @cindex AArch64, bootloaders
28660 Available bootloaders are described in @code{(gnu bootloader @dots{})}
28661 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
28662 of bootloaders for a wide range of ARM and AArch64 systems, using the
28663 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
28665 @item @code{target}
28666 This is a string denoting the target onto which to install the
28669 The interpretation depends on the bootloader in question. For
28670 @code{grub-bootloader}, for example, it should be a device name understood by
28671 the bootloader @command{installer} command, such as @code{/dev/sda} or
28672 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
28673 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
28674 system, usually @file{/boot/efi}.
28676 @item @code{menu-entries} (default: @code{()})
28677 A possibly empty list of @code{menu-entry} objects (see below), denoting
28678 entries to appear in the bootloader menu, in addition to the current
28679 system entry and the entry pointing to previous system generations.
28681 @item @code{default-entry} (default: @code{0})
28682 The index of the default boot menu entry. Index 0 is for the entry of the
28685 @item @code{timeout} (default: @code{5})
28686 The number of seconds to wait for keyboard input before booting. Set to
28687 0 to boot immediately, and to -1 to wait indefinitely.
28689 @cindex keyboard layout, for the bootloader
28690 @item @code{keyboard-layout} (default: @code{#f})
28691 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
28692 layout, usually US@tie{}English (``qwerty'').
28694 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
28698 This option is currently ignored by bootloaders other than @code{grub} and
28702 @item @code{theme} (default: @var{#f})
28703 The bootloader theme object describing the theme to use. If no theme
28704 is provided, some bootloaders might use a default theme, that's true
28707 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
28708 The output terminals used for the bootloader boot menu, as a list of
28709 symbols. GRUB accepts the values: @code{console}, @code{serial},
28710 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
28711 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
28712 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
28713 configuration,,, grub,GNU GRUB manual}).
28715 @item @code{terminal-inputs} (default: @code{'()})
28716 The input terminals used for the bootloader boot menu, as a list of
28717 symbols. For GRUB, the default is the native platform terminal as
28718 determined at run-time. GRUB accepts the values: @code{console},
28719 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
28720 @code{usb_keyboard}. This field corresponds to the GRUB variable
28721 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
28724 @item @code{serial-unit} (default: @code{#f})
28725 The serial unit used by the bootloader, as an integer from 0 to 3.
28726 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
28727 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
28729 @item @code{serial-speed} (default: @code{#f})
28730 The speed of the serial interface, as an integer. For GRUB, the
28731 default value is chosen at run-time; currently GRUB chooses
28732 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
28739 Should you want to list additional boot menu entries @i{via} the
28740 @code{menu-entries} field above, you will need to create them with the
28741 @code{menu-entry} form. For example, imagine you want to be able to
28742 boot another distro (hard to imagine!), you can define a menu entry
28747 (label "The Other Distro")
28748 (linux "/boot/old/vmlinux-2.6.32")
28749 (linux-arguments '("root=/dev/sda2"))
28750 (initrd "/boot/old/initrd"))
28755 @deftp {Data Type} menu-entry
28756 The type of an entry in the bootloader menu.
28761 The label to show in the menu---e.g., @code{"GNU"}.
28763 @item @code{linux} (default: @code{#f})
28764 The Linux kernel image to boot, for example:
28767 (file-append linux-libre "/bzImage")
28770 For GRUB, it is also possible to specify a device explicitly in the
28771 file path using GRUB's device naming convention (@pxref{Naming
28772 convention,,, grub, GNU GRUB manual}), for example:
28775 "(hd0,msdos1)/boot/vmlinuz"
28778 If the device is specified explicitly as above, then the @code{device}
28779 field is ignored entirely.
28781 @item @code{linux-arguments} (default: @code{()})
28782 The list of extra Linux kernel command-line arguments---e.g.,
28783 @code{("console=ttyS0")}.
28785 @item @code{initrd} (default: @code{#f})
28786 A G-Expression or string denoting the file name of the initial RAM disk
28787 to use (@pxref{G-Expressions}).
28789 @item @code{device} (default: @code{#f})
28790 The device where the kernel and initrd are to be found---i.e., for GRUB,
28791 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
28793 This may be a file system label (a string), a file system UUID (a
28794 bytevector, @pxref{File Systems}), or @code{#f}, in which case
28795 the bootloader will search the device containing the file specified by
28796 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
28797 must @emph{not} be an OS device name such as @file{/dev/sda1}.
28799 @item @code{multiboot-kernel} (default: @code{#f})
28800 The kernel to boot in Multiboot-mode (@pxref{multiboot,,, grub, GNU GRUB
28801 manual}). When this field is set, a Multiboot menu-entry is generated.
28805 (file-append mach "/boot/gnumach")
28808 @item @code{multiboot-arguments} (default: @code{()})
28809 The list of extra command-line arguments for the multiboot-kernel.
28811 @item @code{multiboot-modules} (default: @code{()})
28812 The list of commands for loading Multiboot modules. For example:
28815 (list (list (file-append hurd "/hurd/ext2fs.static") "ext2fs"
28817 (list (file-append libc "/lib/ld.so.1") "exec"
28827 @c FIXME: Write documentation once it's stable.
28828 For now only GRUB has theme support. GRUB themes are created using
28829 the @code{grub-theme} form, which is not fully documented yet.
28831 @deftp {Data Type} grub-theme
28832 Data type representing the configuration of the GRUB theme.
28835 @item @code{gfxmode} (default: @code{'("auto")})
28836 The GRUB @code{gfxmode} to set (a list of screen resolution strings, see
28837 @pxref{gfxmode,,, grub, GNU GRUB manual}).
28841 @deffn {Scheme Procedure} grub-theme
28842 Return the default GRUB theme used by the operating system if no
28843 @code{theme} field is specified in @code{bootloader-configuration}
28846 It comes with a fancy background image displaying the GNU and Guix
28850 For example, to override the default resolution, you may use something
28855 (bootloader-configuration
28858 (inherit (grub-theme))
28859 (gfxmode '("1024x786x32" "auto"))))))
28862 @node Invoking guix system
28863 @section Invoking @code{guix system}
28865 Once you have written an operating system declaration as seen in the
28866 previous section, it can be @dfn{instantiated} using the @command{guix
28867 system} command. The synopsis is:
28870 guix system @var{options}@dots{} @var{action} @var{file}
28873 @var{file} must be the name of a file containing an
28874 @code{operating-system} declaration. @var{action} specifies how the
28875 operating system is instantiated. Currently the following values are
28880 Display available service type definitions that match the given regular
28881 expressions, sorted by relevance:
28887 $ guix system search console
28888 name: console-fonts
28889 location: gnu/services/base.scm:806:2
28890 extends: shepherd-root
28891 description: Install the given fonts on the specified ttys (fonts are per
28892 + virtual console on GNU/Linux). The value of this service is a list of
28893 + tty/font pairs. The font can be the name of a font provided by the `kbd'
28894 + package or any valid argument to `setfont', as in this example:
28896 + '(("tty1" . "LatGrkCyr-8x16")
28897 + ("tty2" . (file-append
28899 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
28900 + ("tty3" . (file-append
28902 + "/share/consolefonts/ter-132n"))) ; for HDPI
28906 location: gnu/services/base.scm:1190:2
28907 extends: shepherd-root
28908 description: Provide console login using the `mingetty' program.
28912 location: gnu/services/base.scm:860:2
28914 description: Provide a console log-in service as specified by its
28915 + configuration value, a `login-configuration' object.
28921 As for @command{guix package --search}, the result is written in
28922 @code{recutils} format, which makes it easy to filter the output
28923 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
28926 Build the operating system described in @var{file}, activate it, and
28927 switch to it@footnote{This action (and the related actions
28928 @code{switch-generation} and @code{roll-back}) are usable only on
28929 systems already running Guix System.}.
28932 @c The paragraph below refers to the problem discussed at
28933 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
28934 It is highly recommended to run @command{guix pull} once before you run
28935 @command{guix system reconfigure} for the first time (@pxref{Invoking
28936 guix pull}). Failing to do that you would see an older version of Guix
28937 once @command{reconfigure} has completed.
28940 This effects all the configuration specified in @var{file}: user
28941 accounts, system services, global package list, setuid programs, etc.
28942 The command starts system services specified in @var{file} that are not
28943 currently running; if a service is currently running this command will
28944 arrange for it to be upgraded the next time it is stopped (e.g.@: by
28945 @code{herd stop X} or @code{herd restart X}).
28947 This command creates a new generation whose number is one greater than
28948 the current generation (as reported by @command{guix system
28949 list-generations}). If that generation already exists, it will be
28950 overwritten. This behavior mirrors that of @command{guix package}
28951 (@pxref{Invoking guix package}).
28953 It also adds a bootloader menu entry for the new OS configuration,
28954 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
28955 entries for older configurations to a submenu, allowing you to choose
28956 an older system generation at boot time should you need it.
28958 @cindex provenance tracking, of the operating system
28959 Upon completion, the new system is deployed under
28960 @file{/run/current-system}. This directory contains @dfn{provenance
28961 meta-data}: the list of channels in use (@pxref{Channels}) and
28962 @var{file} itself, when available. You can view it by running:
28965 guix system describe
28968 This information is useful should you later want to inspect how this
28969 particular generation was built. In fact, assuming @var{file} is
28970 self-contained, you can later rebuild generation @var{n} of your
28971 operating system with:
28974 guix time-machine \
28975 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
28976 system reconfigure \
28977 /var/guix/profiles/system-@var{n}-link/configuration.scm
28980 You can think of it as some sort of built-in version control! Your
28981 system is not just a binary artifact: @emph{it carries its own source}.
28982 @xref{Service Reference, @code{provenance-service-type}}, for more
28983 information on provenance tracking.
28985 By default, @command{reconfigure} @emph{prevents you from downgrading
28986 your system}, which could (re)introduce security vulnerabilities and
28987 also cause problems with ``stateful'' services such as database
28988 management systems. You can override that behavior by passing
28989 @option{--allow-downgrades}.
28991 @item switch-generation
28992 @cindex generations
28993 Switch to an existing system generation. This action atomically
28994 switches the system profile to the specified system generation. It
28995 also rearranges the system's existing bootloader menu entries. It
28996 makes the menu entry for the specified system generation the default,
28997 and it moves the entries for the other generations to a submenu, if
28998 supported by the bootloader being used. The next time the system
28999 boots, it will use the specified system generation.
29001 The bootloader itself is not being reinstalled when using this
29002 command. Thus, the installed bootloader is used with an updated
29003 configuration file.
29005 The target generation can be specified explicitly by its generation
29006 number. For example, the following invocation would switch to system
29010 guix system switch-generation 7
29013 The target generation can also be specified relative to the current
29014 generation with the form @code{+N} or @code{-N}, where @code{+3} means
29015 ``3 generations ahead of the current generation,'' and @code{-1} means
29016 ``1 generation prior to the current generation.'' When specifying a
29017 negative value such as @code{-1}, you must precede it with @code{--} to
29018 prevent it from being parsed as an option. For example:
29021 guix system switch-generation -- -1
29024 Currently, the effect of invoking this action is @emph{only} to switch
29025 the system profile to an existing generation and rearrange the
29026 bootloader menu entries. To actually start using the target system
29027 generation, you must reboot after running this action. In the future,
29028 it will be updated to do the same things as @command{reconfigure},
29029 like activating and deactivating services.
29031 This action will fail if the specified generation does not exist.
29034 @cindex rolling back
29035 Switch to the preceding system generation. The next time the system
29036 boots, it will use the preceding system generation. This is the inverse
29037 of @command{reconfigure}, and it is exactly the same as invoking
29038 @command{switch-generation} with an argument of @code{-1}.
29040 Currently, as with @command{switch-generation}, you must reboot after
29041 running this action to actually start using the preceding system
29044 @item delete-generations
29045 @cindex deleting system generations
29046 @cindex saving space
29047 Delete system generations, making them candidates for garbage collection
29048 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
29051 This works in the same way as @samp{guix package --delete-generations}
29052 (@pxref{Invoking guix package, @option{--delete-generations}}). With no
29053 arguments, all system generations but the current one are deleted:
29056 guix system delete-generations
29059 You can also select the generations you want to delete. The example below
29060 deletes all the system generations that are more than two month old:
29063 guix system delete-generations 2m
29066 Running this command automatically reinstalls the bootloader with an updated
29067 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
29068 longer lists the generations that have been deleted.
29071 Build the derivation of the operating system, which includes all the
29072 configuration files and programs needed to boot and run the system.
29073 This action does not actually install anything.
29076 Populate the given directory with all the files necessary to run the
29077 operating system specified in @var{file}. This is useful for first-time
29078 installations of Guix System. For instance:
29081 guix system init my-os-config.scm /mnt
29084 copies to @file{/mnt} all the store items required by the configuration
29085 specified in @file{my-os-config.scm}. This includes configuration
29086 files, packages, and so on. It also creates other essential files
29087 needed for the system to operate correctly---e.g., the @file{/etc},
29088 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
29090 This command also installs bootloader on the target specified in
29091 @file{my-os-config}, unless the @option{--no-bootloader} option was
29095 @cindex virtual machine
29097 @anchor{guix system vm}
29098 Build a virtual machine that contains the operating system declared in
29099 @var{file}, and return a script to run that virtual machine (VM).
29102 The @code{vm} action and others below
29103 can use KVM support in the Linux-libre kernel. Specifically, if the
29104 machine has hardware virtualization support, the corresponding
29105 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
29106 must exist and be readable and writable by the user and by the
29107 build users of the daemon (@pxref{Build Environment Setup}).
29110 Arguments given to the script are passed to QEMU as in the example
29111 below, which enables networking and requests 1@tie{}GiB of RAM for the
29115 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
29118 The VM shares its store with the host system.
29120 Additional file systems can be shared between the host and the VM using
29121 the @option{--share} and @option{--expose} command-line options: the former
29122 specifies a directory to be shared with write access, while the latter
29123 provides read-only access to the shared directory.
29125 The example below creates a VM in which the user's home directory is
29126 accessible read-only, and where the @file{/exchange} directory is a
29127 read-write mapping of @file{$HOME/tmp} on the host:
29130 guix system vm my-config.scm \
29131 --expose=$HOME --share=$HOME/tmp=/exchange
29134 On GNU/Linux, the default is to boot directly to the kernel; this has
29135 the advantage of requiring only a very tiny root disk image since the
29136 store of the host can then be mounted.
29138 The @option{--full-boot} option forces a complete boot sequence, starting
29139 with the bootloader. This requires more disk space since a root image
29140 containing at least the kernel, initrd, and bootloader data files must
29141 be created. The @option{--image-size} option can be used to specify the
29144 @cindex System images, creation in various formats
29145 @cindex Creating system images in various formats
29148 @itemx docker-image
29149 Return a virtual machine, disk image, or Docker image of the operating
29150 system declared in @var{file} that stands alone. By default,
29151 @command{guix system} estimates the size of the image needed to store
29152 the system, but you can use the @option{--image-size} option to specify
29153 a value. Docker images are built to contain exactly what they need, so
29154 the @option{--image-size} option is ignored in the case of
29155 @code{docker-image}.
29157 You can specify the root file system type by using the
29158 @option{--file-system-type} option. It defaults to @code{ext4}. When its
29159 value is @code{iso9660}, the @option{--label} option can be used to specify
29160 a volume ID with @code{disk-image}.
29162 When using @code{vm-image}, the returned image is in qcow2 format, which
29163 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
29164 for more information on how to run the image in a virtual machine.
29166 When using @code{disk-image}, a raw disk image is produced; it can be
29167 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
29168 the device corresponding to a USB stick, one can copy the image to it
29169 using the following command:
29172 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc status=progress
29175 When using @code{docker-image}, a Docker image is produced. Guix builds
29176 the image from scratch, not from a pre-existing Docker base image. As a
29177 result, it contains @emph{exactly} what you define in the operating
29178 system configuration file. You can then load the image and launch a
29179 Docker container using commands like the following:
29182 image_id="`docker load < guix-system-docker-image.tar.gz`"
29183 container_id="`docker create $image_id`"
29184 docker start $container_id
29187 This command starts a new Docker container from the specified image. It
29188 will boot the Guix system in the usual manner, which means it will
29189 start any services you have defined in the operating system
29190 configuration. You can get an interactive shell running in the container
29191 using @command{docker exec}:
29194 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
29197 Depending on what you run in the Docker container, it
29198 may be necessary to give the container additional permissions. For
29199 example, if you intend to build software using Guix inside of the Docker
29200 container, you may need to pass the @option{--privileged} option to
29201 @code{docker create}.
29203 Last, the @option{--network} option applies to @command{guix system
29204 docker-image}: it produces an image where network is supposedly shared
29205 with the host, and thus without services like nscd or NetworkManager.
29208 Return a script to run the operating system declared in @var{file}
29209 within a container. Containers are a set of lightweight isolation
29210 mechanisms provided by the kernel Linux-libre. Containers are
29211 substantially less resource-demanding than full virtual machines since
29212 the kernel, shared objects, and other resources can be shared with the
29213 host system; this also means they provide thinner isolation.
29215 Currently, the script must be run as root in order to support more than
29216 a single user and group. The container shares its store with the host
29219 As with the @code{vm} action (@pxref{guix system vm}), additional file
29220 systems to be shared between the host and container can be specified
29221 using the @option{--share} and @option{--expose} options:
29224 guix system container my-config.scm \
29225 --expose=$HOME --share=$HOME/tmp=/exchange
29229 This option requires Linux-libre 3.19 or newer.
29234 @var{options} can contain any of the common build options (@pxref{Common
29235 Build Options}). In addition, @var{options} can contain one of the
29239 @item --expression=@var{expr}
29240 @itemx -e @var{expr}
29241 Consider the operating-system @var{expr} evaluates to.
29242 This is an alternative to specifying a file which evaluates to an
29244 This is used to generate the Guix system installer @pxref{Building the
29245 Installation Image}).
29247 @item --system=@var{system}
29248 @itemx -s @var{system}
29249 Attempt to build for @var{system} instead of the host system type.
29250 This works as per @command{guix build} (@pxref{Invoking guix build}).
29254 Return the derivation file name of the given operating system without
29257 @cindex provenance tracking, of the operating system
29258 @item --save-provenance
29259 As discussed above, @command{guix system init} and @command{guix system
29260 reconfigure} always save provenance information @i{via} a dedicated
29261 service (@pxref{Service Reference, @code{provenance-service-type}}).
29262 However, other commands don't do that by default. If you wish to, say,
29263 create a virtual machine image that contains provenance information, you
29267 guix system vm-image --save-provenance config.scm
29270 That way, the resulting image will effectively ``embed its own source''
29271 in the form of meta-data in @file{/run/current-system}. With that
29272 information, one can rebuild the image to make sure it really contains
29273 what it pretends to contain; or they could use that to derive a variant
29276 @item --file-system-type=@var{type}
29277 @itemx -t @var{type}
29278 For the @code{disk-image} action, create a file system of the given
29279 @var{type} on the image.
29281 When this option is omitted, @command{guix system} uses @code{ext4}.
29283 @cindex ISO-9660 format
29284 @cindex CD image format
29285 @cindex DVD image format
29286 @option{--file-system-type=iso9660} produces an ISO-9660 image, suitable
29287 for burning on CDs and DVDs.
29289 @item --image-size=@var{size}
29290 For the @code{vm-image} and @code{disk-image} actions, create an image
29291 of the given @var{size}. @var{size} may be a number of bytes, or it may
29292 include a unit as a suffix (@pxref{Block size, size specifications,,
29293 coreutils, GNU Coreutils}).
29295 When this option is omitted, @command{guix system} computes an estimate
29296 of the image size as a function of the size of the system declared in
29301 For the @code{container} action, allow containers to access the host network,
29302 that is, do not create a network namespace.
29304 @item --root=@var{file}
29305 @itemx -r @var{file}
29306 Make @var{file} a symlink to the result, and register it as a garbage
29309 @item --skip-checks
29310 Skip pre-installation safety checks.
29312 By default, @command{guix system init} and @command{guix system
29313 reconfigure} perform safety checks: they make sure the file systems that
29314 appear in the @code{operating-system} declaration actually exist
29315 (@pxref{File Systems}), and that any Linux kernel modules that may be
29316 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
29317 RAM Disk}). Passing this option skips these tests altogether.
29319 @item --allow-downgrades
29320 Instruct @command{guix system reconfigure} to allow system downgrades.
29322 By default, @command{reconfigure} prevents you from downgrading your
29323 system. It achieves that by comparing the provenance info of your
29324 system (shown by @command{guix system describe}) with that of your
29325 @command{guix} command (shown by @command{guix describe}). If the
29326 commits for @command{guix} are not descendants of those used for your
29327 system, @command{guix system reconfigure} errors out. Passing
29328 @option{--allow-downgrades} allows you to bypass these checks.
29331 Make sure you understand its security implications before using
29332 @option{--allow-downgrades}.
29336 @cindex on-error strategy
29337 @cindex error strategy
29338 @item --on-error=@var{strategy}
29339 Apply @var{strategy} when an error occurs when reading @var{file}.
29340 @var{strategy} may be one of the following:
29343 @item nothing-special
29344 Report the error concisely and exit. This is the default strategy.
29347 Likewise, but also display a backtrace.
29350 Report the error and enter Guile's debugger. From there, you can run
29351 commands such as @code{,bt} to get a backtrace, @code{,locals} to
29352 display local variable values, and more generally inspect the state of the
29353 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
29354 a list of available debugging commands.
29358 Once you have built, configured, re-configured, and re-re-configured
29359 your Guix installation, you may find it useful to list the operating
29360 system generations available on disk---and that you can choose from the
29361 bootloader boot menu:
29366 Describe the current system generation: its file name, the kernel and
29367 bootloader used, etc., as well as provenance information when available.
29369 @item list-generations
29370 List a summary of each generation of the operating system available on
29371 disk, in a human-readable way. This is similar to the
29372 @option{--list-generations} option of @command{guix package}
29373 (@pxref{Invoking guix package}).
29375 Optionally, one can specify a pattern, with the same syntax that is used
29376 in @command{guix package --list-generations}, to restrict the list of
29377 generations displayed. For instance, the following command displays
29378 generations that are up to 10 days old:
29381 $ guix system list-generations 10d
29386 The @command{guix system} command has even more to offer! The following
29387 sub-commands allow you to visualize how your system services relate to
29390 @anchor{system-extension-graph}
29393 @item extension-graph
29394 Emit in Dot/Graphviz format to standard output the @dfn{service
29395 extension graph} of the operating system defined in @var{file}
29396 (@pxref{Service Composition}, for more information on service
29402 $ guix system extension-graph @var{file} | xdot -
29405 shows the extension relations among services.
29407 @anchor{system-shepherd-graph}
29408 @item shepherd-graph
29409 Emit in Dot/Graphviz format to standard output the @dfn{dependency
29410 graph} of shepherd services of the operating system defined in
29411 @var{file}. @xref{Shepherd Services}, for more information and for an
29416 @node Invoking guix deploy
29417 @section Invoking @code{guix deploy}
29419 We've already seen @code{operating-system} declarations used to manage a
29420 machine's configuration locally. Suppose you need to configure multiple
29421 machines, though---perhaps you're managing a service on the web that's
29422 comprised of several servers. @command{guix deploy} enables you to use those
29423 same @code{operating-system} declarations to manage multiple remote hosts at
29424 once as a logical ``deployment''.
29427 The functionality described in this section is still under development
29428 and is subject to change. Get in touch with us on
29429 @email{guix-devel@@gnu.org}!
29433 guix deploy @var{file}
29436 Such an invocation will deploy the machines that the code within @var{file}
29437 evaluates to. As an example, @var{file} might contain a definition like this:
29440 ;; This is a Guix deployment of a "bare bones" setup, with
29441 ;; no X11 display server, to a machine with an SSH daemon
29442 ;; listening on localhost:2222. A configuration such as this
29443 ;; may be appropriate for virtual machine with ports
29444 ;; forwarded to the host's loopback interface.
29446 (use-service-modules networking ssh)
29447 (use-package-modules bootloaders)
29451 (host-name "gnu-deployed")
29452 (timezone "Etc/UTC")
29453 (bootloader (bootloader-configuration
29454 (bootloader grub-bootloader)
29455 (target "/dev/vda")
29456 (terminal-outputs '(console))))
29457 (file-systems (cons (file-system
29459 (device "/dev/vda1")
29461 %base-file-systems))
29463 (append (list (service dhcp-client-service-type)
29464 (service openssh-service-type
29465 (openssh-configuration
29466 (permit-root-login #t)
29467 (allow-empty-passwords? #t))))
29471 (operating-system %system)
29472 (environment managed-host-environment-type)
29473 (configuration (machine-ssh-configuration
29474 (host-name "localhost")
29475 (system "x86_64-linux")
29477 (identity "./id_rsa")
29481 The file should evaluate to a list of @var{machine} objects. This example,
29482 upon being deployed, will create a new generation on the remote system
29483 realizing the @code{operating-system} declaration @code{%system}.
29484 @code{environment} and @code{configuration} specify how the machine should be
29485 provisioned---that is, how the computing resources should be created and
29486 managed. The above example does not create any resources, as a
29487 @code{'managed-host} is a machine that is already running the Guix system and
29488 available over the network. This is a particularly simple case; a more
29489 complex deployment may involve, for example, starting virtual machines through
29490 a Virtual Private Server (VPS) provider. In such a case, a different
29491 @var{environment} type would be used.
29493 Do note that you first need to generate a key pair on the coordinator machine
29494 to allow the daemon to export signed archives of files from the store
29495 (@pxref{Invoking guix archive}).
29498 # guix archive --generate-key
29502 Each target machine must authorize the key of the master machine so that it
29503 accepts store items it receives from the coordinator:
29506 # guix archive --authorize < coordinator-public-key.txt
29509 @code{user}, in this example, specifies the name of the user account to log in
29510 as to perform the deployment. Its default value is @code{root}, but root
29511 login over SSH may be forbidden in some cases. To work around this,
29512 @command{guix deploy} can log in as an unprivileged user and employ
29513 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
29514 currently installed on the remote and can be invoked non-interactively as
29515 @code{user}. That is, the line in @code{sudoers} granting @code{user} the
29516 ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
29517 be accomplished with the following operating system configuration snippet:
29521 (gnu system)) ;for %sudoers-specification
29523 (define %user "username")
29528 (plain-file "sudoers"
29529 (string-append (plain-file-content %sudoers-specification)
29530 (format #f "~a ALL = NOPASSWD: ALL~%"
29535 For more information regarding the format of the @file{sudoers} file,
29536 consult @command{man sudoers}.
29538 @deftp {Data Type} machine
29539 This is the data type representing a single machine in a heterogeneous Guix
29543 @item @code{operating-system}
29544 The object of the operating system configuration to deploy.
29546 @item @code{environment}
29547 An @code{environment-type} describing how the machine should be provisioned.
29549 @item @code{configuration} (default: @code{#f})
29550 An object describing the configuration for the machine's @code{environment}.
29551 If the @code{environment} has a default configuration, @code{#f} may be used.
29552 If @code{#f} is used for an environment with no default configuration,
29553 however, an error will be thrown.
29557 @deftp {Data Type} machine-ssh-configuration
29558 This is the data type representing the SSH client parameters for a machine
29559 with an @code{environment} of @code{managed-host-environment-type}.
29562 @item @code{host-name}
29563 @item @code{build-locally?} (default: @code{#t})
29564 If false, system derivations will be built on the machine being deployed to.
29565 @item @code{system}
29566 The system type describing the architecture of the machine being deployed
29567 to---e.g., @code{"x86_64-linux"}.
29568 @item @code{authorize?} (default: @code{#t})
29569 If true, the coordinator's signing key will be added to the remote's ACL
29571 @item @code{port} (default: @code{22})
29572 @item @code{user} (default: @code{"root"})
29573 @item @code{identity} (default: @code{#f})
29574 If specified, the path to the SSH private key to use to authenticate with the
29577 @item @code{host-key} (default: @code{#f})
29578 This should be the SSH host key of the machine, which looks like this:
29581 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
29584 When @code{host-key} is @code{#f}, the server is authenticated against
29585 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
29588 @item @code{allow-downgrades?} (default: @code{#f})
29589 Whether to allow potential downgrades.
29591 Like @command{guix system reconfigure}, @command{guix deploy} compares
29592 the channel commits currently deployed on the remote host (as returned
29593 by @command{guix system describe}) to those currently in use (as
29594 returned by @command{guix describe}) to determine whether commits
29595 currently in use are descendants of those deployed. When this is not
29596 the case and @code{allow-downgrades?} is false, it raises an error.
29597 This ensures you do not accidentally downgrade remote machines.
29601 @deftp {Data Type} digital-ocean-configuration
29602 This is the data type describing the Droplet that should be created for a
29603 machine with an @code{environment} of @code{digital-ocean-environment-type}.
29606 @item @code{ssh-key}
29607 The path to the SSH private key to use to authenticate with the remote
29608 host. In the future, this field may not exist.
29610 A list of string ``tags'' that uniquely identify the machine. Must be given
29611 such that no two machines in the deployment have the same set of tags.
29612 @item @code{region}
29613 A Digital Ocean region slug, such as @code{"nyc3"}.
29615 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
29616 @item @code{enable-ipv6?}
29617 Whether or not the droplet should be created with IPv6 networking.
29621 @node Running Guix in a VM
29622 @section Running Guix in a Virtual Machine
29624 @cindex virtual machine
29625 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
29627 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
29628 This image is a compressed image in QCOW format. You will first need to
29629 decompress with @command{xz -d}, and then you can pass it to an emulator such
29630 as QEMU (see below for details).
29632 This image boots the Xfce graphical environment and it contains some
29633 commonly-used tools. You can install more software in the image by running
29634 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
29635 also reconfigure the system based on its initial configuration file available
29636 as @file{/run/current-system/configuration.scm} (@pxref{Using the
29637 Configuration System}).
29639 Instead of using this pre-built image, one can also build their own virtual
29640 machine image using @command{guix system vm-image} (@pxref{Invoking guix
29641 system}). The returned image is in qcow2 format, which the
29642 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
29645 If you built your own image, you must copy it out of the store
29646 (@pxref{The Store}) and give yourself permission to write to the copy
29647 before you can use it. When invoking QEMU, you must choose a system
29648 emulator that is suitable for your hardware platform. Here is a minimal
29649 QEMU invocation that will boot the result of @command{guix system
29650 vm-image} on x86_64 hardware:
29653 $ qemu-system-x86_64 \
29654 -nic user,model=virtio-net-pci \
29655 -enable-kvm -m 1024 \
29656 -device virtio-blk,drive=myhd \
29657 -drive if=none,file=/tmp/qemu-image,id=myhd
29660 Here is what each of these options means:
29663 @item qemu-system-x86_64
29664 This specifies the hardware platform to emulate. This should match the
29667 @item -nic user,model=virtio-net-pci
29668 Enable the unprivileged user-mode network stack. The guest OS can
29669 access the host but not vice versa. This is the simplest way to get the
29670 guest OS online. @code{model} specifies which network device to emulate:
29671 @code{virtio-net-pci} is a special device made for virtualized operating
29672 systems and recommended for most uses. Assuming your hardware platform is
29673 x86_64, you can get a list of available NIC models by running
29674 @command{qemu-system-x86_64 -nic model=help}.
29677 If your system has hardware virtualization extensions, enabling the
29678 virtual machine support (KVM) of the Linux kernel will make things run
29681 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
29683 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
29684 which may be insufficient for some operations.
29686 @item -device virtio-blk,drive=myhd
29687 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
29688 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
29689 better performance than if it were emulating a complete disk drive. See the
29690 QEMU and KVM documentation for more info.
29692 @item -drive if=none,file=/tmp/qemu-image,id=myhd
29693 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
29694 the ``myhd'' drive.
29697 The default @command{run-vm.sh} script that is returned by an invocation of
29698 @command{guix system vm} does not add a @command{-nic user} flag by default.
29699 To get network access from within the vm add the @code{(dhcp-client-service)}
29700 to your system definition and start the VM using
29701 @command{`guix system vm config.scm` -nic user}. An important caveat of using
29702 @command{-nic user} for networking is that @command{ping} will not work, because
29703 it uses the ICMP protocol. You'll have to use a different command to check for
29704 network connectivity, for example @command{guix download}.
29706 @subsection Connecting Through SSH
29710 To enable SSH inside a VM you need to add an SSH server like
29711 @code{openssh-service-type} to your VM (@pxref{Networking Services,
29712 @code{openssh-service-type}}). In addition you need to forward the SSH port,
29713 22 by default, to the host. You can do this with
29716 `guix system vm config.scm` -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
29719 To connect to the VM you can run
29722 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
29725 The @command{-p} tells @command{ssh} the port you want to connect to.
29726 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
29727 every time you modify your @command{config.scm} file and the
29728 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
29729 connection to an unknown host every time you connect.
29731 @subsection Using @command{virt-viewer} with Spice
29733 As an alternative to the default @command{qemu} graphical client you can
29734 use the @command{remote-viewer} from the @command{virt-viewer} package. To
29735 connect pass the @command{-spice port=5930,disable-ticketing} flag to
29736 @command{qemu}. See previous section for further information on how to do this.
29738 Spice also allows you to do some nice stuff like share your clipboard with your
29739 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
29742 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
29743 -chardev spicevmc,name=vdagent,id=vdagent
29744 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
29745 name=com.redhat.spice.0
29748 You'll also need to add the @code{(spice-vdagent-service)} to your
29749 system definition (@pxref{Miscellaneous Services, Spice service}).
29751 @node Defining Services
29752 @section Defining Services
29754 The previous sections show the available services and how one can combine
29755 them in an @code{operating-system} declaration. But how do we define
29756 them in the first place? And what is a service anyway?
29759 * Service Composition:: The model for composing services.
29760 * Service Types and Services:: Types and services.
29761 * Service Reference:: API reference.
29762 * Shepherd Services:: A particular type of service.
29765 @node Service Composition
29766 @subsection Service Composition
29770 Here we define a @dfn{service} as, broadly, something that extends the
29771 functionality of the operating system. Often a service is a process---a
29772 @dfn{daemon}---started when the system boots: a secure shell server, a
29773 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
29774 whose execution can be triggered by another daemon---e.g., an FTP server
29775 started by @command{inetd} or a D-Bus service activated by
29776 @command{dbus-daemon}. Occasionally, a service does not map to a
29777 daemon. For instance, the ``account'' service collects user accounts
29778 and makes sure they exist when the system runs; the ``udev'' service
29779 collects device management rules and makes them available to the eudev
29780 daemon; the @file{/etc} service populates the @file{/etc} directory
29783 @cindex service extensions
29784 Guix system services are connected by @dfn{extensions}. For instance, the
29785 secure shell service @emph{extends} the Shepherd---the
29786 initialization system, running as PID@tie{}1---by giving it the command
29787 lines to start and stop the secure shell daemon (@pxref{Networking
29788 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
29789 service by passing it its @file{.service} specification, and extends the
29790 udev service by passing it device management rules (@pxref{Desktop
29791 Services, @code{upower-service}}); the Guix daemon service extends the
29792 Shepherd by passing it the command lines to start and stop the daemon,
29793 and extends the account service by passing it a list of required build
29794 user accounts (@pxref{Base Services}).
29796 All in all, services and their ``extends'' relations form a directed
29797 acyclic graph (DAG). If we represent services as boxes and extensions
29798 as arrows, a typical system might provide something like this:
29800 @image{images/service-graph,,5in,Typical service extension graph.}
29802 @cindex system service
29803 At the bottom, we see the @dfn{system service}, which produces the
29804 directory containing everything to run and boot the system, as returned
29805 by the @command{guix system build} command. @xref{Service Reference},
29806 to learn about the other service types shown here.
29807 @xref{system-extension-graph, the @command{guix system extension-graph}
29808 command}, for information on how to generate this representation for a
29809 particular operating system definition.
29811 @cindex service types
29812 Technically, developers can define @dfn{service types} to express these
29813 relations. There can be any number of services of a given type on the
29814 system---for instance, a system running two instances of the GNU secure
29815 shell server (lsh) has two instances of @code{lsh-service-type}, with
29816 different parameters.
29818 The following section describes the programming interface for service
29819 types and services.
29821 @node Service Types and Services
29822 @subsection Service Types and Services
29824 A @dfn{service type} is a node in the DAG described above. Let us start
29825 with a simple example, the service type for the Guix build daemon
29826 (@pxref{Invoking guix-daemon}):
29829 (define guix-service-type
29833 (list (service-extension shepherd-root-service-type guix-shepherd-service)
29834 (service-extension account-service-type guix-accounts)
29835 (service-extension activation-service-type guix-activation)))
29836 (default-value (guix-configuration))))
29840 It defines three things:
29844 A name, whose sole purpose is to make inspection and debugging easier.
29847 A list of @dfn{service extensions}, where each extension designates the
29848 target service type and a procedure that, given the parameters of the
29849 service, returns a list of objects to extend the service of that type.
29851 Every service type has at least one service extension. The only
29852 exception is the @dfn{boot service type}, which is the ultimate service.
29855 Optionally, a default value for instances of this type.
29858 In this example, @code{guix-service-type} extends three services:
29861 @item shepherd-root-service-type
29862 The @code{guix-shepherd-service} procedure defines how the Shepherd
29863 service is extended. Namely, it returns a @code{<shepherd-service>}
29864 object that defines how @command{guix-daemon} is started and stopped
29865 (@pxref{Shepherd Services}).
29867 @item account-service-type
29868 This extension for this service is computed by @code{guix-accounts},
29869 which returns a list of @code{user-group} and @code{user-account}
29870 objects representing the build user accounts (@pxref{Invoking
29873 @item activation-service-type
29874 Here @code{guix-activation} is a procedure that returns a gexp, which is
29875 a code snippet to run at ``activation time''---e.g., when the service is
29879 A service of this type is instantiated like this:
29882 (service guix-service-type
29883 (guix-configuration
29885 (use-substitutes? #f)))
29888 The second argument to the @code{service} form is a value representing
29889 the parameters of this specific service instance.
29890 @xref{guix-configuration-type, @code{guix-configuration}}, for
29891 information about the @code{guix-configuration} data type. When the
29892 value is omitted, the default value specified by
29893 @code{guix-service-type} is used:
29896 (service guix-service-type)
29899 @code{guix-service-type} is quite simple because it extends other
29900 services but is not extensible itself.
29902 @c @subsubsubsection Extensible Service Types
29904 The service type for an @emph{extensible} service looks like this:
29907 (define udev-service-type
29908 (service-type (name 'udev)
29910 (list (service-extension shepherd-root-service-type
29911 udev-shepherd-service)))
29913 (compose concatenate) ;concatenate the list of rules
29914 (extend (lambda (config rules)
29916 (($ <udev-configuration> udev initial-rules)
29917 (udev-configuration
29918 (udev udev) ;the udev package to use
29919 (rules (append initial-rules rules)))))))))
29922 This is the service type for the
29923 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
29924 management daemon}. Compared to the previous example, in addition to an
29925 extension of @code{shepherd-root-service-type}, we see two new fields:
29929 This is the procedure to @dfn{compose} the list of extensions to
29930 services of this type.
29932 Services can extend the udev service by passing it lists of rules; we
29933 compose those extensions simply by concatenating them.
29936 This procedure defines how the value of the service is @dfn{extended} with
29937 the composition of the extensions.
29939 Udev extensions are composed into a list of rules, but the udev service
29940 value is itself a @code{<udev-configuration>} record. So here, we
29941 extend that record by appending the list of rules it contains to the
29942 list of contributed rules.
29945 This is a string giving an overview of the service type. The string can
29946 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
29947 @command{guix system search} command searches these strings and displays
29948 them (@pxref{Invoking guix system}).
29951 There can be only one instance of an extensible service type such as
29952 @code{udev-service-type}. If there were more, the
29953 @code{service-extension} specifications would be ambiguous.
29955 Still here? The next section provides a reference of the programming
29956 interface for services.
29958 @node Service Reference
29959 @subsection Service Reference
29961 We have seen an overview of service types (@pxref{Service Types and
29962 Services}). This section provides a reference on how to manipulate
29963 services and service types. This interface is provided by the
29964 @code{(gnu services)} module.
29966 @deffn {Scheme Procedure} service @var{type} [@var{value}]
29967 Return a new service of @var{type}, a @code{<service-type>} object (see
29968 below). @var{value} can be any object; it represents the parameters of
29969 this particular service instance.
29971 When @var{value} is omitted, the default value specified by @var{type}
29972 is used; if @var{type} does not specify a default value, an error is
29975 For instance, this:
29978 (service openssh-service-type)
29982 is equivalent to this:
29985 (service openssh-service-type
29986 (openssh-configuration))
29989 In both cases the result is an instance of @code{openssh-service-type}
29990 with the default configuration.
29993 @deffn {Scheme Procedure} service? @var{obj}
29994 Return true if @var{obj} is a service.
29997 @deffn {Scheme Procedure} service-kind @var{service}
29998 Return the type of @var{service}---i.e., a @code{<service-type>} object.
30001 @deffn {Scheme Procedure} service-value @var{service}
30002 Return the value associated with @var{service}. It represents its
30006 Here is an example of how a service is created and manipulated:
30010 (service nginx-service-type
30011 (nginx-configuration
30013 (log-directory log-directory)
30014 (run-directory run-directory)
30015 (file config-file))))
30020 (eq? (service-kind s) nginx-service-type)
30024 The @code{modify-services} form provides a handy way to change the
30025 parameters of some of the services of a list such as
30026 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
30027 evaluates to a list of services. Of course, you could always use
30028 standard list combinators such as @code{map} and @code{fold} to do that
30029 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
30030 @code{modify-services} simply provides a more concise form for this
30033 @deffn {Scheme Syntax} modify-services @var{services} @
30034 (@var{type} @var{variable} => @var{body}) @dots{}
30036 Modify the services listed in @var{services} according to the given
30037 clauses. Each clause has the form:
30040 (@var{type} @var{variable} => @var{body})
30043 where @var{type} is a service type---e.g.,
30044 @code{guix-service-type}---and @var{variable} is an identifier that is
30045 bound within the @var{body} to the service parameters---e.g., a
30046 @code{guix-configuration} instance---of the original service of that
30049 The @var{body} should evaluate to the new service parameters, which will
30050 be used to configure the new service. This new service will replace the
30051 original in the resulting list. Because a service's service parameters
30052 are created using @code{define-record-type*}, you can write a succinct
30053 @var{body} that evaluates to the new service parameters by using the
30054 @code{inherit} feature that @code{define-record-type*} provides.
30056 @xref{Using the Configuration System}, for example usage.
30060 Next comes the programming interface for service types. This is
30061 something you want to know when writing new service definitions, but not
30062 necessarily when simply looking for ways to customize your
30063 @code{operating-system} declaration.
30065 @deftp {Data Type} service-type
30066 @cindex service type
30067 This is the representation of a @dfn{service type} (@pxref{Service Types
30072 This is a symbol, used only to simplify inspection and debugging.
30074 @item @code{extensions}
30075 A non-empty list of @code{<service-extension>} objects (see below).
30077 @item @code{compose} (default: @code{#f})
30078 If this is @code{#f}, then the service type denotes services that cannot
30079 be extended---i.e., services that do not receive ``values'' from other
30082 Otherwise, it must be a one-argument procedure. The procedure is called
30083 by @code{fold-services} and is passed a list of values collected from
30084 extensions. It may return any single value.
30086 @item @code{extend} (default: @code{#f})
30087 If this is @code{#f}, services of this type cannot be extended.
30089 Otherwise, it must be a two-argument procedure: @code{fold-services}
30090 calls it, passing it the initial value of the service as the first
30091 argument and the result of applying @code{compose} to the extension
30092 values as the second argument. It must return a value that is a valid
30093 parameter value for the service instance.
30095 @item @code{description}
30096 This is a string, possibly using Texinfo markup, describing in a couple
30097 of sentences what the service is about. This string allows users to
30098 find about the service through @command{guix system search}
30099 (@pxref{Invoking guix system}).
30101 @item @code{default-value} (default: @code{&no-default-value})
30102 The default value associated for instances of this service type. This
30103 allows users to use the @code{service} form without its second argument:
30106 (service @var{type})
30109 The returned service in this case has the default value specified by
30113 @xref{Service Types and Services}, for examples.
30116 @deffn {Scheme Procedure} service-extension @var{target-type} @
30118 Return a new extension for services of type @var{target-type}.
30119 @var{compute} must be a one-argument procedure: @code{fold-services}
30120 calls it, passing it the value associated with the service that provides
30121 the extension; it must return a valid value for the target service.
30124 @deffn {Scheme Procedure} service-extension? @var{obj}
30125 Return true if @var{obj} is a service extension.
30128 Occasionally, you might want to simply extend an existing service. This
30129 involves creating a new service type and specifying the extension of
30130 interest, which can be verbose; the @code{simple-service} procedure
30131 provides a shorthand for this.
30133 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
30134 Return a service that extends @var{target} with @var{value}. This works
30135 by creating a singleton service type @var{name}, of which the returned
30136 service is an instance.
30138 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
30142 (simple-service 'my-mcron-job mcron-service-type
30143 #~(job '(next-hour (3)) "guix gc -F 2G"))
30147 At the core of the service abstraction lies the @code{fold-services}
30148 procedure, which is responsible for ``compiling'' a list of services
30149 down to a single directory that contains everything needed to boot and
30150 run the system---the directory shown by the @command{guix system build}
30151 command (@pxref{Invoking guix system}). In essence, it propagates
30152 service extensions down the service graph, updating each node parameters
30153 on the way, until it reaches the root node.
30155 @deffn {Scheme Procedure} fold-services @var{services} @
30156 [#:target-type @var{system-service-type}]
30157 Fold @var{services} by propagating their extensions down to the root of
30158 type @var{target-type}; return the root service adjusted accordingly.
30161 Lastly, the @code{(gnu services)} module also defines several essential
30162 service types, some of which are listed below.
30164 @defvr {Scheme Variable} system-service-type
30165 This is the root of the service graph. It produces the system directory
30166 as returned by the @command{guix system build} command.
30169 @defvr {Scheme Variable} boot-service-type
30170 The type of the ``boot service'', which produces the @dfn{boot script}.
30171 The boot script is what the initial RAM disk runs when booting.
30174 @defvr {Scheme Variable} etc-service-type
30175 The type of the @file{/etc} service. This service is used to create
30176 files under @file{/etc} and can be extended by
30177 passing it name/file tuples such as:
30180 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
30183 In this example, the effect would be to add an @file{/etc/issue} file
30184 pointing to the given file.
30187 @defvr {Scheme Variable} setuid-program-service-type
30188 Type for the ``setuid-program service''. This service collects lists of
30189 executable file names, passed as gexps, and adds them to the set of
30190 setuid-root programs on the system (@pxref{Setuid Programs}).
30193 @defvr {Scheme Variable} profile-service-type
30194 Type of the service that populates the @dfn{system profile}---i.e., the
30195 programs under @file{/run/current-system/profile}. Other services can
30196 extend it by passing it lists of packages to add to the system profile.
30199 @cindex provenance tracking, of the operating system
30200 @anchor{provenance-service-type}
30201 @defvr {Scheme Variable} provenance-service-type
30202 This is the type of the service that records @dfn{provenance meta-data}
30203 in the system itself. It creates several files under
30204 @file{/run/current-system}:
30208 This is a ``channel file'' that can be passed to @command{guix pull -C}
30209 or @command{guix time-machine -C}, and which describes the channels used
30210 to build the system, if that information was available
30211 (@pxref{Channels}).
30213 @item configuration.scm
30214 This is the file that was passed as the value for this
30215 @code{provenance-service-type} service. By default, @command{guix
30216 system reconfigure} automatically passes the OS configuration file it
30217 received on the command line.
30220 This contains the same information as the two other files but in a
30221 format that is more readily processable.
30224 In general, these two pieces of information (channels and configuration
30225 file) are enough to reproduce the operating system ``from source''.
30228 This information is necessary to rebuild your operating system, but it
30229 is not always sufficient. In particular, @file{configuration.scm}
30230 itself is insufficient if it is not self-contained---if it refers to
30231 external Guile modules or to extra files. If you want
30232 @file{configuration.scm} to be self-contained, we recommend that modules
30233 or files it refers to be part of a channel.
30235 Besides, provenance meta-data is ``silent'' in the sense that it does
30236 not change the bits contained in your system, @emph{except for the
30237 meta-data bits themselves}. Two different OS configurations or sets of
30238 channels can lead to the same system, bit-for-bit; when
30239 @code{provenance-service-type} is used, these two systems will have
30240 different meta-data and thus different store file names, which makes
30241 comparison less trivial.
30244 This service is automatically added to your operating system
30245 configuration when you use @command{guix system reconfigure},
30246 @command{guix system init}, or @command{guix deploy}.
30249 @node Shepherd Services
30250 @subsection Shepherd Services
30252 @cindex shepherd services
30254 @cindex init system
30255 The @code{(gnu services shepherd)} module provides a way to define
30256 services managed by the GNU@tie{}Shepherd, which is the
30257 initialization system---the first process that is started when the
30258 system boots, also known as PID@tie{}1
30259 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
30261 Services in the Shepherd can depend on each other. For instance, the
30262 SSH daemon may need to be started after the syslog daemon has been
30263 started, which in turn can only happen once all the file systems have
30264 been mounted. The simple operating system defined earlier (@pxref{Using
30265 the Configuration System}) results in a service graph like this:
30267 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
30269 You can actually generate such a graph for any operating system
30270 definition using the @command{guix system shepherd-graph} command
30271 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
30273 The @code{%shepherd-root-service} is a service object representing
30274 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
30275 by passing it lists of @code{<shepherd-service>} objects.
30277 @deftp {Data Type} shepherd-service
30278 The data type representing a service managed by the Shepherd.
30281 @item @code{provision}
30282 This is a list of symbols denoting what the service provides.
30284 These are the names that may be passed to @command{herd start},
30285 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
30286 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
30287 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
30289 @item @code{requirement} (default: @code{'()})
30290 List of symbols denoting the Shepherd services this one depends on.
30292 @cindex one-shot services, for the Shepherd
30293 @item @code{one-shot?} (default: @code{#f})
30294 Whether this service is @dfn{one-shot}. One-shot services stop immediately
30295 after their @code{start} action has completed. @xref{Slots of services,,,
30296 shepherd, The GNU Shepherd Manual}, for more info.
30298 @item @code{respawn?} (default: @code{#t})
30299 Whether to restart the service when it stops, for instance when the
30300 underlying process dies.
30303 @itemx @code{stop} (default: @code{#~(const #f)})
30304 The @code{start} and @code{stop} fields refer to the Shepherd's
30305 facilities to start and stop processes (@pxref{Service De- and
30306 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
30307 G-expressions that get expanded in the Shepherd configuration file
30308 (@pxref{G-Expressions}).
30310 @item @code{actions} (default: @code{'()})
30311 @cindex actions, of Shepherd services
30312 This is a list of @code{shepherd-action} objects (see below) defining
30313 @dfn{actions} supported by the service, in addition to the standard
30314 @code{start} and @code{stop} actions. Actions listed here become available as
30315 @command{herd} sub-commands:
30318 herd @var{action} @var{service} [@var{arguments}@dots{}]
30321 @item @code{auto-start?} (default: @code{#t})
30322 Whether this service should be started automatically by the Shepherd. If it
30323 is @code{#f} the service has to be started manually with @code{herd start}.
30325 @item @code{documentation}
30326 A documentation string, as shown when running:
30329 herd doc @var{service-name}
30332 where @var{service-name} is one of the symbols in @code{provision}
30333 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
30335 @item @code{modules} (default: @code{%default-modules})
30336 This is the list of modules that must be in scope when @code{start} and
30337 @code{stop} are evaluated.
30342 @deftp {Data Type} shepherd-action
30343 This is the data type that defines additional actions implemented by a
30344 Shepherd service (see above).
30348 Symbol naming the action.
30350 @item documentation
30351 This is a documentation string for the action. It can be viewed by running:
30354 herd doc @var{service} action @var{action}
30358 This should be a gexp that evaluates to a procedure of at least one argument,
30359 which is the ``running value'' of the service (@pxref{Slots of services,,,
30360 shepherd, The GNU Shepherd Manual}).
30363 The following example defines an action called @code{say-hello} that kindly
30369 (documentation "Say hi!")
30370 (procedure #~(lambda (running . args)
30371 (format #t "Hello, friend! arguments: ~s\n"
30376 Assuming this action is added to the @code{example} service, then you can do:
30379 # herd say-hello example
30380 Hello, friend! arguments: ()
30381 # herd say-hello example a b c
30382 Hello, friend! arguments: ("a" "b" "c")
30385 This, as you can see, is a fairly sophisticated way to say hello.
30386 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
30390 @defvr {Scheme Variable} shepherd-root-service-type
30391 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
30393 This is the service type that extensions target when they want to create
30394 shepherd services (@pxref{Service Types and Services}, for an example).
30395 Each extension must pass a list of @code{<shepherd-service>}.
30398 @defvr {Scheme Variable} %shepherd-root-service
30399 This service represents PID@tie{}1.
30403 @node Documentation
30404 @chapter Documentation
30406 @cindex documentation, searching for
30407 @cindex searching for documentation
30408 @cindex Info, documentation format
30410 @cindex manual pages
30411 In most cases packages installed with Guix come with documentation.
30412 There are two main documentation formats: ``Info'', a browseable
30413 hypertext format used for GNU software, and ``manual pages'' (or ``man
30414 pages''), the linear documentation format traditionally found on Unix.
30415 Info manuals are accessed with the @command{info} command or with Emacs,
30416 and man pages are accessed using @command{man}.
30418 You can look for documentation of software installed on your system by
30419 keyword. For example, the following command searches for information
30420 about ``TLS'' in Info manuals:
30424 "(emacs)Network Security" -- STARTTLS
30425 "(emacs)Network Security" -- TLS
30426 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
30427 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
30432 The command below searches for the same keyword in man pages:
30436 SSL (7) - OpenSSL SSL/TLS library
30437 certtool (1) - GnuTLS certificate tool
30441 These searches are purely local to your computer so you have the
30442 guarantee that documentation you find corresponds to what you have
30443 actually installed, you can access it off-line, and your privacy is
30446 Once you have these results, you can view the relevant documentation by
30450 $ info "(gnutls)Core TLS API"
30460 Info manuals contain sections and indices as well as hyperlinks like
30461 those found in Web pages. The @command{info} reader (@pxref{Top, Info
30462 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
30463 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
30464 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
30465 Introduction}, for an introduction to Info navigation.
30467 @node Installing Debugging Files
30468 @chapter Installing Debugging Files
30470 @cindex debugging files
30471 Program binaries, as produced by the GCC compilers for instance, are
30472 typically written in the ELF format, with a section containing
30473 @dfn{debugging information}. Debugging information is what allows the
30474 debugger, GDB, to map binary code to source code; it is required to
30475 debug a compiled program in good conditions.
30477 The problem with debugging information is that is takes up a fair amount
30478 of disk space. For example, debugging information for the GNU C Library
30479 weighs in at more than 60 MiB. Thus, as a user, keeping all the
30480 debugging info of all the installed programs is usually not an option.
30481 Yet, space savings should not come at the cost of an impediment to
30482 debugging---especially in the GNU system, which should make it easier
30483 for users to exert their computing freedom (@pxref{GNU Distribution}).
30485 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
30486 mechanism that allows users to get the best of both worlds: debugging
30487 information can be stripped from the binaries and stored in separate
30488 files. GDB is then able to load debugging information from those files,
30489 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
30492 The GNU distribution takes advantage of this by storing debugging
30493 information in the @code{lib/debug} sub-directory of a separate package
30494 output unimaginatively called @code{debug} (@pxref{Packages with
30495 Multiple Outputs}). Users can choose to install the @code{debug} output
30496 of a package when they need it. For instance, the following command
30497 installs the debugging information for the GNU C Library and for GNU
30501 guix install glibc:debug guile:debug
30504 GDB must then be told to look for debug files in the user's profile, by
30505 setting the @code{debug-file-directory} variable (consider setting it
30506 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
30510 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
30513 From there on, GDB will pick up debugging information from the
30514 @file{.debug} files under @file{~/.guix-profile/lib/debug}.
30516 In addition, you will most likely want GDB to be able to show the source
30517 code being debugged. To do that, you will have to unpack the source
30518 code of the package of interest (obtained with @code{guix build
30519 --source}, @pxref{Invoking guix build}), and to point GDB to that source
30520 directory using the @code{directory} command (@pxref{Source Path,
30521 @code{directory},, gdb, Debugging with GDB}).
30523 @c XXX: keep me up-to-date
30524 The @code{debug} output mechanism in Guix is implemented by the
30525 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
30526 opt-in---debugging information is available only for the packages
30527 with definitions explicitly declaring a @code{debug} output. This may be
30528 changed to opt-out in the future if our build farm servers can handle
30529 the load. To check whether a package has a @code{debug} output, use
30530 @command{guix package --list-available} (@pxref{Invoking guix package}).
30533 @node Security Updates
30534 @chapter Security Updates
30536 @cindex security updates
30537 @cindex security vulnerabilities
30538 Occasionally, important security vulnerabilities are discovered in software
30539 packages and must be patched. Guix developers try hard to keep track of
30540 known vulnerabilities and to apply fixes as soon as possible in the
30541 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
30542 containing only security updates). The @command{guix lint} tool helps
30543 developers find out about vulnerable versions of software packages in the
30548 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
30549 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
30550 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
30554 @xref{Invoking guix lint}, for more information.
30556 Guix follows a functional
30557 package management discipline (@pxref{Introduction}), which implies
30558 that, when a package is changed, @emph{every package that depends on it}
30559 must be rebuilt. This can significantly slow down the deployment of
30560 fixes in core packages such as libc or Bash, since basically the whole
30561 distribution would need to be rebuilt. Using pre-built binaries helps
30562 (@pxref{Substitutes}), but deployment may still take more time than
30566 To address this, Guix implements @dfn{grafts}, a mechanism that allows
30567 for fast deployment of critical updates without the costs associated
30568 with a whole-distribution rebuild. The idea is to rebuild only the
30569 package that needs to be patched, and then to ``graft'' it onto packages
30570 explicitly installed by the user and that were previously referring to
30571 the original package. The cost of grafting is typically very low, and
30572 order of magnitudes lower than a full rebuild of the dependency chain.
30574 @cindex replacements of packages, for grafts
30575 For instance, suppose a security update needs to be applied to Bash.
30576 Guix developers will provide a package definition for the ``fixed''
30577 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
30578 Packages}). Then, the original package definition is augmented with a
30579 @code{replacement} field pointing to the package containing the bug fix:
30586 (replacement bash-fixed)))
30589 From there on, any package depending directly or indirectly on Bash---as
30590 reported by @command{guix gc --requisites} (@pxref{Invoking guix
30591 gc})---that is installed is automatically ``rewritten'' to refer to
30592 @code{bash-fixed} instead of @code{bash}. This grafting process takes
30593 time proportional to the size of the package, usually less than a
30594 minute for an ``average'' package on a recent machine. Grafting is
30595 recursive: when an indirect dependency requires grafting, then grafting
30596 ``propagates'' up to the package that the user is installing.
30598 Currently, the length of the name and version of the graft and that of
30599 the package it replaces (@code{bash-fixed} and @code{bash} in the example
30600 above) must be equal. This restriction mostly comes from the fact that
30601 grafting works by patching files, including binary files, directly.
30602 Other restrictions may apply: for instance, when adding a graft to a
30603 package providing a shared library, the original shared library and its
30604 replacement must have the same @code{SONAME} and be binary-compatible.
30606 The @option{--no-grafts} command-line option allows you to forcefully
30607 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
30611 guix build bash --no-grafts
30615 returns the store file name of the original Bash, whereas:
30622 returns the store file name of the ``fixed'', replacement Bash. This
30623 allows you to distinguish between the two variants of Bash.
30625 To verify which Bash your whole profile refers to, you can run
30626 (@pxref{Invoking guix gc}):
30629 guix gc -R `readlink -f ~/.guix-profile` | grep bash
30633 @dots{} and compare the store file names that you get with those above.
30634 Likewise for a complete Guix system generation:
30637 guix gc -R `guix system build my-config.scm` | grep bash
30640 Lastly, to check which Bash running processes are using, you can use the
30641 @command{lsof} command:
30644 lsof | grep /gnu/store/.*bash
30648 @node Bootstrapping
30649 @chapter Bootstrapping
30651 @c Adapted from the ELS 2013 paper.
30653 @cindex bootstrapping
30655 Bootstrapping in our context refers to how the distribution gets built
30656 ``from nothing''. Remember that the build environment of a derivation
30657 contains nothing but its declared inputs (@pxref{Introduction}). So
30658 there's an obvious chicken-and-egg problem: how does the first package
30659 get built? How does the first compiler get compiled? Note that this is
30660 a question of interest only to the curious hacker, not to the regular
30661 user, so you can shamelessly skip this section if you consider yourself
30662 a ``regular user''.
30664 @cindex bootstrap binaries
30665 The GNU system is primarily made of C code, with libc at its core. The
30666 GNU build system itself assumes the availability of a Bourne shell and
30667 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
30668 `grep'. Furthermore, build programs---programs that run
30669 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
30670 (@pxref{Derivations}). Consequently, to be able to build anything at
30671 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
30672 Binutils, libc, and the other packages mentioned above---the
30673 @dfn{bootstrap binaries}.
30675 These bootstrap binaries are ``taken for granted'', though we can also
30676 re-create them if needed (@pxref{Preparing to Use the Bootstrap
30680 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
30681 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
30684 @node Reduced Binary Seed Bootstrap
30685 @section The Reduced Binary Seed Bootstrap
30687 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
30688 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
30689 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
30690 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
30691 ``taken for granted.''
30693 Taking the bootstrap binaries for granted means that we consider them to
30694 be a correct and trustworthy ``seed'' for building the complete system.
30695 Therein lies a problem: the combined size of these bootstrap binaries is
30696 about 250MB (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing
30697 or even inspecting these is next to impossible.
30699 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a
30700 ``Reduced Binary Seed'' bootstrap @footnote{We would like to say: ``Full
30701 Source Bootstrap'' and while we are working towards that goal it would
30702 be hyperbole to use that term for what we do now.}.
30704 The Reduced Binary Seed bootstrap removes the most critical tools---from a
30705 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
30706 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
30707 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
30708 written in Scheme and the Mes C Library, built for TinyCC and for GCC).
30710 Using these new binary seeds the ``missing'' Binutils, GCC, and the GNU
30711 C Library are built from source. From here on the more traditional
30712 bootstrap process resumes. This approach has reduced the bootstrap
30713 binaries in size to about 145MB in Guix v1.1.
30715 The next step that Guix has taken is to replace the shell and all its
30716 utilities with implementations in Guile Scheme, the @emph{Scheme-only
30717 bootstrap}. Gash (@pxref{Gash,,, gash, The Gash manual}) is a
30718 POSIX-compatible shell that replaces Bash, and it comes with Gash Utils
30719 which has minimalist replacements for Awk, the GNU Core Utilities, Grep,
30720 Gzip, Sed, and Tar. The rest of the bootstrap binary seeds that were
30721 removed are now built from source.
30723 Building the GNU System from source is currently only possibly by adding
30724 some historical GNU packages as intermediate steps@footnote{Packages
30725 such as @code{gcc-2.95.3}, @code{binutils-2.14}, @code{glibc-2.2.5},
30726 @code{gzip-1.2.4}, @code{tar-1.22}, and some others. For details, see
30727 @file{gnu/packages/commencement.scm}.}. As Gash and Gash Utils mature,
30728 and GNU packages become more bootstrappable again (e.g., new releases of
30729 GNU Sed will also ship as gzipped tarballs again, as alternative to the
30730 hard to bootstrap @code{xz}-compression), this set of added packages can
30731 hopefully be reduced again.
30733 The graph below shows the resulting dependency graph for
30734 @code{gcc-core-mesboot0}, the bootstrap compiler used for the
30735 traditional bootstrap of the rest of the Guix System.
30737 @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
30738 @image{images/gcc-core-mesboot0-graph,6in,,Dependency graph of gcc-core-mesboot0}
30740 The only significant binary bootstrap seeds that remain@footnote{
30741 Ignoring the 68KB @code{mescc-tools}; that will be removed later,
30742 together with @code{mes}.} are a Scheme intepreter and a Scheme
30743 compiler: GNU Mes and GNU Guile@footnote{Not shown in this graph are the
30744 static binaries for @file{bash}, @code{tar}, and @code{xz} that are used
30745 to get Guile running.}.
30747 This further reduction has brought down the size of the binary seed to
30748 about 60MB for @code{i686-linux} and @code{x86_64-linux}.
30750 Work is ongoing to remove all binary blobs from our free software
30751 bootstrap stack, working towards a Full Source Bootstrap. Also ongoing
30752 is work to bring these bootstraps to the @code{arm-linux} and
30753 @code{aarch64-linux} architectures and to the Hurd.
30755 If you are interested, join us on @samp{#bootstrappable} on the Freenode
30756 IRC network or discuss on @email{bug-mes@@gnu.org} or
30757 @email{gash-devel@@nongnu.org}.
30759 @node Preparing to Use the Bootstrap Binaries
30760 @section Preparing to Use the Bootstrap Binaries
30762 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
30763 @c large image, it's hard to scroll. Oh well.
30764 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
30766 The figure above shows the very beginning of the dependency graph of the
30767 distribution, corresponding to the package definitions of the @code{(gnu
30768 packages bootstrap)} module. A similar figure can be generated with
30769 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
30772 guix graph -t derivation \
30773 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
30774 | dot -Tps > gcc.ps
30777 or, for the further Reduced Binary Seed bootstrap
30780 guix graph -t derivation \
30781 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
30782 | dot -Tps > mes.ps
30785 At this level of detail, things are
30786 slightly complex. First, Guile itself consists of an ELF executable,
30787 along with many source and compiled Scheme files that are dynamically
30788 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
30789 tarball shown in this graph. This tarball is part of Guix's ``source''
30790 distribution, and gets inserted into the store with @code{add-to-store}
30791 (@pxref{The Store}).
30793 But how do we write a derivation that unpacks this tarball and adds it
30794 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
30795 derivation---the first one that gets built---uses @code{bash} as its
30796 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
30797 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
30798 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
30799 the Guix source distribution, whose sole purpose is to allow the Guile
30800 tarball to be unpacked.
30802 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
30803 Guile that can be used to run subsequent build programs. Its first task
30804 is to download tarballs containing the other pre-built binaries---this
30805 is what the @file{.tar.xz.drv} derivations do. Guix modules such as
30806 @code{ftp-client.scm} are used for this purpose. The
30807 @code{module-import.drv} derivations import those modules in a directory
30808 in the store, using the original layout. The
30809 @code{module-import-compiled.drv} derivations compile those modules, and
30810 write them in an output directory with the right layout. This
30811 corresponds to the @code{#:modules} argument of
30812 @code{build-expression->derivation} (@pxref{Derivations}).
30814 Finally, the various tarballs are unpacked by the derivations
30815 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
30816 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
30817 point we have a working C tool chain.
30819 @unnumberedsec Building the Build Tools
30821 Bootstrapping is complete when we have a full tool chain that does not
30822 depend on the pre-built bootstrap tools discussed above. This
30823 no-dependency requirement is verified by checking whether the files of
30824 the final tool chain contain references to the @file{/gnu/store}
30825 directories of the bootstrap inputs. The process that leads to this
30826 ``final'' tool chain is described by the package definitions found in
30827 the @code{(gnu packages commencement)} module.
30829 The @command{guix graph} command allows us to ``zoom out'' compared to
30830 the graph above, by looking at the level of package objects instead of
30831 individual derivations---remember that a package may translate to
30832 several derivations, typically one derivation to download its source,
30833 one to build the Guile modules it needs, and one to actually build the
30834 package from source. The command:
30837 guix graph -t bag \
30838 -e '(@@@@ (gnu packages commencement)
30839 glibc-final-with-bootstrap-bash)' | xdot -
30843 displays the dependency graph leading to the ``final'' C
30844 library@footnote{You may notice the @code{glibc-intermediate} label,
30845 suggesting that it is not @emph{quite} final, but as a good
30846 approximation, we will consider it final.}, depicted below.
30848 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
30850 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
30851 The first tool that gets built with the bootstrap binaries is
30852 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
30853 for all the following packages. From there Findutils and Diffutils get
30856 Then come the first-stage Binutils and GCC, built as pseudo cross
30857 tools---i.e., with @option{--target} equal to @option{--host}. They are
30858 used to build libc. Thanks to this cross-build trick, this libc is
30859 guaranteed not to hold any reference to the initial tool chain.
30861 From there the final Binutils and GCC (not shown above) are built. GCC
30862 uses @command{ld} from the final Binutils, and links programs against
30863 the just-built libc. This tool chain is used to build the other
30864 packages used by Guix and by the GNU Build System: Guile, Bash,
30867 And voilà! At this point we have the complete set of build tools that
30868 the GNU Build System expects. These are in the @code{%final-inputs}
30869 variable of the @code{(gnu packages commencement)} module, and are
30870 implicitly used by any package that uses @code{gnu-build-system}
30871 (@pxref{Build Systems, @code{gnu-build-system}}).
30874 @unnumberedsec Building the Bootstrap Binaries
30876 @cindex bootstrap binaries
30877 Because the final tool chain does not depend on the bootstrap binaries,
30878 those rarely need to be updated. Nevertheless, it is useful to have an
30879 automated way to produce them, should an update occur, and this is what
30880 the @code{(gnu packages make-bootstrap)} module provides.
30882 The following command builds the tarballs containing the bootstrap binaries
30883 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
30884 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
30885 and Guile, and a tarball containing a mixture of Coreutils and other basic
30886 command-line tools):
30889 guix build bootstrap-tarballs
30892 The generated tarballs are those that should be referred to in the
30893 @code{(gnu packages bootstrap)} module mentioned at the beginning of
30896 Still here? Then perhaps by now you've started to wonder: when do we
30897 reach a fixed point? That is an interesting question! The answer is
30898 unknown, but if you would like to investigate further (and have
30899 significant computational and storage resources to do so), then let us
30902 @unnumberedsec Reducing the Set of Bootstrap Binaries
30904 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
30905 binary code! Why is that a problem? It's a problem because these big chunks
30906 of binary code are practically non-auditable, which makes it hard to establish
30907 what source code produced them. Every unauditable binary also leaves us
30908 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
30909 paper @emph{Reflections on Trusting Trust}.
30911 This is mitigated by the fact that our bootstrap binaries were generated
30912 from an earlier Guix revision. Nevertheless it lacks the level of
30913 transparency that we get in the rest of the package dependency graph,
30914 where Guix always gives us a source-to-binary mapping. Thus, our goal
30915 is to reduce the set of bootstrap binaries to the bare minimum.
30917 The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
30918 on-going projects to do that. One of these is about replacing the
30919 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
30920 of increasing complexity, which could be built from source starting from
30921 a simple and auditable assembler.
30923 Our first major achievement is the replacement of of GCC, the GNU C Library
30924 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
30925 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
30926 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
30927 bootstrapped yet and thus we inject them as binary seeds. We call this the
30928 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
30929 binaries! Also, it has eliminated the C compiler binary; i686-linux and
30930 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
30932 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
30933 also looking at any other bootstrap binaries. Your help is welcome!
30936 @chapter Porting to a New Platform
30938 As discussed above, the GNU distribution is self-contained, and
30939 self-containment is achieved by relying on pre-built ``bootstrap
30940 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
30941 operating system kernel, CPU architecture, and application binary
30942 interface (ABI). Thus, to port the distribution to a platform that is
30943 not yet supported, one must build those bootstrap binaries, and update
30944 the @code{(gnu packages bootstrap)} module to use them on that platform.
30946 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
30947 When everything goes well, and assuming the GNU tool chain supports the
30948 target platform, this can be as simple as running a command like this
30952 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
30955 For this to work, the @code{glibc-dynamic-linker} procedure in
30956 @code{(gnu packages bootstrap)} must be augmented to return the right
30957 file name for libc's dynamic linker on that platform; likewise,
30958 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
30959 taught about the new platform.
30961 Once these are built, the @code{(gnu packages bootstrap)} module needs
30962 to be updated to refer to these binaries on the target platform. That
30963 is, the hashes and URLs of the bootstrap tarballs for the new platform
30964 must be added alongside those of the currently supported platforms. The
30965 bootstrap Guile tarball is treated specially: it is expected to be
30966 available locally, and @file{gnu/local.mk} has rules to download it for
30967 the supported architectures; a rule for the new platform must be added
30970 In practice, there may be some complications. First, it may be that the
30971 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
30972 above) is not recognized by all the GNU tools. Typically, glibc
30973 recognizes some of these, whereas GCC uses an extra @option{--with-abi}
30974 configure flag (see @code{gcc.scm} for examples of how to handle this).
30975 Second, some of the required packages could fail to build for that
30976 platform. Lastly, the generated binaries could be broken for some
30979 @c *********************************************************************
30980 @include contributing.texi
30982 @c *********************************************************************
30983 @node Acknowledgments
30984 @chapter Acknowledgments
30986 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
30987 which was designed and
30988 implemented by Eelco Dolstra, with contributions from other people (see
30989 the @file{nix/AUTHORS} file in Guix). Nix pioneered functional package
30990 management, and promoted unprecedented features, such as transactional
30991 package upgrades and rollbacks, per-user profiles, and referentially
30992 transparent build processes. Without this work, Guix would not exist.
30994 The Nix-based software distributions, Nixpkgs and NixOS, have also been
30995 an inspiration for Guix.
30997 GNU@tie{}Guix itself is a collective work with contributions from a
30998 number of people. See the @file{AUTHORS} file in Guix for more
30999 information on these fine people. The @file{THANKS} file lists people
31000 who have helped by reporting bugs, taking care of the infrastructure,
31001 providing artwork and themes, making suggestions, and more---thank you!
31004 @c *********************************************************************
31005 @node GNU Free Documentation License
31006 @appendix GNU Free Documentation License
31007 @cindex license, GNU Free Documentation License
31008 @include fdl-1.3.texi
31010 @c *********************************************************************
31011 @node Concept Index
31012 @unnumbered Concept Index
31015 @node Programming Index
31016 @unnumbered Programming Index
31017 @syncodeindex tp fn
31018 @syncodeindex vr fn
31023 @c Local Variables:
31024 @c ispell-local-dictionary: "american";