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/,
794 Guile-JSON} 4.3.0 or later;
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 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
4994 comparable in spirit to `tar', but with differences
4995 that make it more appropriate for our purposes. First, rather than
4996 recording all Unix metadata for each file, the nar format only mentions
4997 the file type (regular, directory, or symbolic link); Unix permissions
4998 and owner/group are dismissed. Second, the order in which directory
4999 entries are stored always follows the order of file names according to
5000 the C locale collation order. This makes archive production fully
5003 When exporting, the daemon digitally signs the contents of the archive,
5004 and that digital signature is appended. When importing, the daemon
5005 verifies the signature and rejects the import in case of an invalid
5006 signature or if the signing key is not authorized.
5007 @c FIXME: Add xref to daemon doc about signatures.
5009 The main options are:
5013 Export the specified store files or packages (see below). Write the
5014 resulting archive to the standard output.
5016 Dependencies are @emph{not} included in the output, unless
5017 @option{--recursive} is passed.
5021 When combined with @option{--export}, this instructs @command{guix archive}
5022 to include dependencies of the given items in the archive. Thus, the
5023 resulting archive is self-contained: it contains the closure of the
5024 exported store items.
5027 Read an archive from the standard input, and import the files listed
5028 therein into the store. Abort if the archive has an invalid digital
5029 signature, or if it is signed by a public key not among the authorized
5030 keys (see @option{--authorize} below).
5033 Read a list of store file names from the standard input, one per line,
5034 and write on the standard output the subset of these files missing from
5037 @item --generate-key[=@var{parameters}]
5038 @cindex signing, archives
5039 Generate a new key pair for the daemon. This is a prerequisite before
5040 archives can be exported with @option{--export}. Note that this
5041 operation usually takes time, because it needs to gather enough entropy
5042 to generate the key pair.
5044 The generated key pair is typically stored under @file{/etc/guix}, in
5045 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
5046 key, which must be kept secret). When @var{parameters} is omitted,
5047 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
5048 versions before 1.6.0, it is a 4096-bit RSA key.
5049 Alternatively, @var{parameters} can specify
5050 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
5051 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
5052 Libgcrypt Reference Manual}).
5055 @cindex authorizing, archives
5056 Authorize imports signed by the public key passed on standard input.
5057 The public key must be in ``s-expression advanced format''---i.e., the
5058 same format as the @file{signing-key.pub} file.
5060 The list of authorized keys is kept in the human-editable file
5061 @file{/etc/guix/acl}. The file contains
5062 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
5063 s-expressions''} and is structured as an access-control list in the
5064 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
5067 @item --extract=@var{directory}
5068 @itemx -x @var{directory}
5069 Read a single-item archive as served by substitute servers
5070 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
5071 low-level operation needed in only very narrow use cases; see below.
5073 For example, the following command extracts the substitute for Emacs
5074 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
5078 https://@value{SUBSTITUTE-SERVER}/nar/gzip/@dots{}-emacs-24.5 \
5079 | gunzip | guix archive -x /tmp/emacs
5082 Single-item archives are different from multiple-item archives produced
5083 by @command{guix archive --export}; they contain a single store item,
5084 and they do @emph{not} embed a signature. Thus this operation does
5085 @emph{no} signature verification and its output should be considered
5088 The primary purpose of this operation is to facilitate inspection of
5089 archive contents coming from possibly untrusted substitute servers
5090 (@pxref{Invoking guix challenge}).
5094 Read a single-item archive as served by substitute servers
5095 (@pxref{Substitutes}) and print the list of files it contains, as in
5100 https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-emacs-26.3 \
5101 | lzip -d | guix archive -t
5107 @c *********************************************************************
5109 @chapter Development
5111 @cindex software development
5112 If you are a software developer, Guix provides tools that you should find
5113 helpful---independently of the language you're developing in. This is what
5114 this chapter is about.
5116 The @command{guix environment} command provides a convenient way to set up
5117 @dfn{development environments} containing all the dependencies and tools
5118 necessary to work on the software package of your choice. The @command{guix
5119 pack} command allows you to create @dfn{application bundles} that can be
5120 easily distributed to users who do not run Guix.
5123 * Invoking guix environment:: Setting up development environments.
5124 * Invoking guix pack:: Creating software bundles.
5125 * The GCC toolchain:: Working with languages supported by GCC.
5126 * Invoking guix git authenticate:: Authenticating Git repositories.
5129 @node Invoking guix environment
5130 @section Invoking @command{guix environment}
5132 @cindex reproducible build environments
5133 @cindex development environments
5134 @cindex @command{guix environment}
5135 @cindex environment, package build environment
5136 The purpose of @command{guix environment} is to assist hackers in
5137 creating reproducible development environments without polluting their
5138 package profile. The @command{guix environment} tool takes one or more
5139 packages, builds all of their inputs, and creates a shell
5140 environment to use them.
5142 The general syntax is:
5145 guix environment @var{options} @var{package}@dots{}
5148 The following example spawns a new shell set up for the development of
5152 guix environment guile
5155 If the needed dependencies are not built yet, @command{guix environment}
5156 automatically builds them. The environment of the new shell is an
5157 augmented version of the environment that @command{guix environment} was
5158 run in. It contains the necessary search paths for building the given
5159 package added to the existing environment variables. To create
5160 a ``pure'' environment, in which the original environment variables have
5161 been unset, use the @option{--pure} option@footnote{Users sometimes
5162 wrongfully augment environment variables such as @env{PATH} in their
5163 @file{~/.bashrc} file. As a consequence, when @command{guix
5164 environment} launches it, Bash may read @file{~/.bashrc}, thereby
5165 introducing ``impurities'' in these environment variables. It is an
5166 error to define such environment variables in @file{.bashrc}; instead,
5167 they should be defined in @file{.bash_profile}, which is sourced only by
5168 log-in shells. @xref{Bash Startup Files,,, bash, The GNU Bash Reference
5169 Manual}, for details on Bash start-up files.}.
5171 @vindex GUIX_ENVIRONMENT
5172 @command{guix environment} defines the @env{GUIX_ENVIRONMENT}
5173 variable in the shell it spawns; its value is the file name of the
5174 profile of this environment. This allows users to, say, define a
5175 specific prompt for development environments in their @file{.bashrc}
5176 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
5179 if [ -n "$GUIX_ENVIRONMENT" ]
5181 export PS1="\u@@\h \w [dev]\$ "
5186 ...@: or to browse the profile:
5189 $ ls "$GUIX_ENVIRONMENT/bin"
5192 Additionally, more than one package may be specified, in which case the
5193 union of the inputs for the given packages are used. For example, the
5194 command below spawns a shell where all of the dependencies of both Guile
5195 and Emacs are available:
5198 guix environment guile emacs
5201 Sometimes an interactive shell session is not desired. An arbitrary
5202 command may be invoked by placing the @code{--} token to separate the
5203 command from the rest of the arguments:
5206 guix environment guile -- make -j4
5209 In other situations, it is more convenient to specify the list of
5210 packages needed in the environment. For example, the following command
5211 runs @command{python} from an environment containing Python@tie{}2.7 and
5215 guix environment --ad-hoc python2-numpy python-2.7 -- python
5218 Furthermore, one might want the dependencies of a package and also some
5219 additional packages that are not build-time or runtime dependencies, but
5220 are useful when developing nonetheless. Because of this, the
5221 @option{--ad-hoc} flag is positional. Packages appearing before
5222 @option{--ad-hoc} are interpreted as packages whose dependencies will be
5223 added to the environment. Packages appearing after are interpreted as
5224 packages that will be added to the environment directly. For example,
5225 the following command creates a Guix development environment that
5226 additionally includes Git and strace:
5229 guix environment --pure guix --ad-hoc git strace
5233 Sometimes it is desirable to isolate the environment as much as
5234 possible, for maximal purity and reproducibility. In particular, when
5235 using Guix on a host distro that is not Guix System, it is desirable to
5236 prevent access to @file{/usr/bin} and other system-wide resources from
5237 the development environment. For example, the following command spawns
5238 a Guile REPL in a ``container'' where only the store and the current
5239 working directory are mounted:
5242 guix environment --ad-hoc --container guile -- guile
5246 The @option{--container} option requires Linux-libre 3.19 or newer.
5249 @cindex certificates
5250 Another typical use case for containers is to run security-sensitive
5251 applications such as a web browser. To run Eolie, we must expose and
5252 share some files and directories; we include @code{nss-certs} and expose
5253 @file{/etc/ssl/certs/} for HTTPS authentication; finally we preserve the
5254 the @env{DISPLAY} environment variable since containerized graphical
5255 applications won't display without it.
5258 guix environment --preserve='^DISPLAY$' --container --network \
5259 --expose=/etc/machine-id \
5260 --expose=/etc/ssl/certs/ \
5261 --share=$HOME/.local/share/eolie/=$HOME/.local/share/eolie/ \
5262 --ad-hoc eolie nss-certs dbus -- eolie
5265 The available options are summarized below.
5268 @item --root=@var{file}
5269 @itemx -r @var{file}
5270 @cindex persistent environment
5271 @cindex garbage collector root, for environments
5272 Make @var{file} a symlink to the profile for this environment, and
5273 register it as a garbage collector root.
5275 This is useful if you want to protect your environment from garbage
5276 collection, to make it ``persistent''.
5278 When this option is omitted, the environment is protected from garbage
5279 collection only for the duration of the @command{guix environment}
5280 session. This means that next time you recreate the same environment,
5281 you could have to rebuild or re-download packages. @xref{Invoking guix
5282 gc}, for more on GC roots.
5284 @item --expression=@var{expr}
5285 @itemx -e @var{expr}
5286 Create an environment for the package or list of packages that
5287 @var{expr} evaluates to.
5289 For example, running:
5292 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
5295 starts a shell with the environment for this specific variant of the
5301 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
5304 starts a shell with all the base system packages available.
5306 The above commands only use the default output of the given packages.
5307 To select other outputs, two element tuples can be specified:
5310 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
5313 @item --load=@var{file}
5314 @itemx -l @var{file}
5315 Create an environment for the package or list of packages that the code
5316 within @var{file} evaluates to.
5318 As an example, @var{file} might contain a definition like this
5319 (@pxref{Defining Packages}):
5322 @verbatiminclude environment-gdb.scm
5325 @item --manifest=@var{file}
5326 @itemx -m @var{file}
5327 Create an environment for the packages contained in the manifest object
5328 returned by the Scheme code in @var{file}. This option can be repeated
5329 several times, in which case the manifests are concatenated.
5331 This is similar to the same-named option in @command{guix package}
5332 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
5336 Include all specified packages in the resulting environment, as if an
5337 @i{ad hoc} package were defined with them as inputs. This option is
5338 useful for quickly creating an environment without having to write a
5339 package expression to contain the desired inputs.
5341 For instance, the command:
5344 guix environment --ad-hoc guile guile-sdl -- guile
5347 runs @command{guile} in an environment where Guile and Guile-SDL are
5350 Note that this example implicitly asks for the default output of
5351 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
5352 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
5353 of @code{glib} (@pxref{Packages with Multiple Outputs}).
5355 This option may be composed with the default behavior of @command{guix
5356 environment}. Packages appearing before @option{--ad-hoc} are
5357 interpreted as packages whose dependencies will be added to the
5358 environment, the default behavior. Packages appearing after are
5359 interpreted as packages that will be added to the environment directly.
5362 Unset existing environment variables when building the new environment, except
5363 those specified with @option{--preserve} (see below). This has the effect of
5364 creating an environment in which search paths only contain package inputs.
5366 @item --preserve=@var{regexp}
5367 @itemx -E @var{regexp}
5368 When used alongside @option{--pure}, preserve the environment variables
5369 matching @var{regexp}---in other words, put them on a ``white list'' of
5370 environment variables that must be preserved. This option can be repeated
5374 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
5378 This example runs @command{mpirun} in a context where the only environment
5379 variables defined are @env{PATH}, environment variables whose name starts
5380 with @samp{SLURM}, as well as the usual ``precious'' variables (@env{HOME},
5383 @item --search-paths
5384 Display the environment variable definitions that make up the
5387 @item --system=@var{system}
5388 @itemx -s @var{system}
5389 Attempt to build for @var{system}---e.g., @code{i686-linux}.
5394 Run @var{command} within an isolated container. The current working
5395 directory outside the container is mapped inside the container.
5396 Additionally, unless overridden with @option{--user}, a dummy home
5397 directory is created that matches the current user's home directory, and
5398 @file{/etc/passwd} is configured accordingly.
5400 The spawned process runs as the current user outside the container. Inside
5401 the container, it has the same UID and GID as the current user, unless
5402 @option{--user} is passed (see below).
5406 For containers, share the network namespace with the host system.
5407 Containers created without this flag only have access to the loopback
5410 @item --link-profile
5412 For containers, link the environment profile to @file{~/.guix-profile}
5413 within the container. This is equivalent to running the command
5414 @samp{ln -s $GUIX_ENVIRONMENT ~/.guix-profile} within the container.
5415 Linking will fail and abort the environment if the directory already
5416 exists, which will certainly be the case if @command{guix environment}
5417 was invoked in the user's home directory.
5419 Certain packages are configured to look in @file{~/.guix-profile} for
5420 configuration files and data;@footnote{For example, the
5421 @code{fontconfig} package inspects @file{~/.guix-profile/share/fonts}
5422 for additional fonts.} @option{--link-profile} allows these programs to
5423 behave as expected within the environment.
5425 @item --user=@var{user}
5426 @itemx -u @var{user}
5427 For containers, use the username @var{user} in place of the current
5428 user. The generated @file{/etc/passwd} entry within the container will
5429 contain the name @var{user}, the home directory will be
5430 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
5431 the UID and GID inside the container are 1000. @var{user}
5432 need not exist on the system.
5434 Additionally, any shared or exposed path (see @option{--share} and
5435 @option{--expose} respectively) whose target is within the current user's
5436 home directory will be remapped relative to @file{/home/USER}; this
5437 includes the automatic mapping of the current working directory.
5440 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
5442 guix environment --container --user=foo \
5443 --expose=$HOME/test \
5444 --expose=/tmp/target=$HOME/target
5447 While this will limit the leaking of user identity through home paths
5448 and each of the user fields, this is only one useful component of a
5449 broader privacy/anonymity solution---not one in and of itself.
5452 For containers, the default behavior is to share the current working
5453 directory with the isolated container and immediately change to that
5454 directory within the container. If this is undesirable,
5455 @option{--no-cwd} will cause the current working directory to @emph{not}
5456 be automatically shared and will change to the user's home directory
5457 within the container instead. See also @option{--user}.
5459 @item --expose=@var{source}[=@var{target}]
5460 @itemx --share=@var{source}[=@var{target}]
5461 For containers, @option{--expose} (resp. @option{--share}) exposes the
5462 file system @var{source} from the host system as the read-only
5463 (resp. writable) file system @var{target} within the container. If
5464 @var{target} is not specified, @var{source} is used as the target mount
5465 point in the container.
5467 The example below spawns a Guile REPL in a container in which the user's
5468 home directory is accessible read-only via the @file{/exchange}
5472 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
5477 @command{guix environment}
5478 also supports all of the common build options that @command{guix
5479 build} supports (@pxref{Common Build Options}) as well as package
5480 transformation options (@pxref{Package Transformation Options}).
5482 @node Invoking guix pack
5483 @section Invoking @command{guix pack}
5485 Occasionally you want to pass software to people who are not (yet!)
5486 lucky enough to be using Guix. You'd tell them to run @command{guix
5487 package -i @var{something}}, but that's not possible in this case. This
5488 is where @command{guix pack} comes in.
5491 If you are looking for ways to exchange binaries among machines that
5492 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
5493 publish}, and @ref{Invoking guix archive}.
5498 @cindex application bundle
5499 @cindex software bundle
5500 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
5501 @dfn{software bundle}: it creates a tarball or some other archive
5502 containing the binaries of the software you're interested in, and all
5503 its dependencies. The resulting archive can be used on any machine that
5504 does not have Guix, and people can run the exact same binaries as those
5505 you have with Guix. The pack itself is created in a bit-reproducible
5506 fashion, so anyone can verify that it really contains the build results
5507 that you pretend to be shipping.
5509 For example, to create a bundle containing Guile, Emacs, Geiser, and all
5510 their dependencies, you can run:
5513 $ guix pack guile emacs geiser
5515 /gnu/store/@dots{}-pack.tar.gz
5518 The result here is a tarball containing a @file{/gnu/store} directory
5519 with all the relevant packages. The resulting tarball contains a
5520 @dfn{profile} with the three packages of interest; the profile is the
5521 same as would be created by @command{guix package -i}. It is this
5522 mechanism that is used to create Guix's own standalone binary tarball
5523 (@pxref{Binary Installation}).
5525 Users of this pack would have to run
5526 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
5527 find inconvenient. To work around it, you can create, say, a
5528 @file{/opt/gnu/bin} symlink to the profile:
5531 guix pack -S /opt/gnu/bin=bin guile emacs geiser
5535 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
5537 @cindex relocatable binaries, with @command{guix pack}
5538 What if the recipient of your pack does not have root privileges on
5539 their machine, and thus cannot unpack it in the root file system? In
5540 that case, you will want to use the @option{--relocatable} option (see
5541 below). This option produces @dfn{relocatable binaries}, meaning they
5542 they can be placed anywhere in the file system hierarchy: in the example
5543 above, users can unpack your tarball in their home directory and
5544 directly run @file{./opt/gnu/bin/guile}.
5546 @cindex Docker, build an image with guix pack
5547 Alternatively, you can produce a pack in the Docker image format using
5548 the following command:
5551 guix pack -f docker -S /bin=bin guile guile-readline
5555 The result is a tarball that can be passed to the @command{docker load}
5556 command, followed by @code{docker run}:
5559 docker load < @var{file}
5560 docker run -ti guile-guile-readline /bin/guile
5564 where @var{file} is the image returned by @var{guix pack}, and
5565 @code{guile-guile-readline} is its ``image tag''. See the
5566 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5567 documentation} for more information.
5569 @cindex Singularity, build an image with guix pack
5570 @cindex SquashFS, build an image with guix pack
5571 Yet another option is to produce a SquashFS image with the following
5575 guix pack -f squashfs bash guile emacs geiser
5579 The result is a SquashFS file system image that can either be mounted or
5580 directly be used as a file system container image with the
5581 @uref{https://www.sylabs.io/docs/, Singularity container execution
5582 environment}, using commands like @command{singularity shell} or
5583 @command{singularity exec}.
5585 Several command-line options allow you to customize your pack:
5588 @item --format=@var{format}
5589 @itemx -f @var{format}
5590 Produce a pack in the given @var{format}.
5592 The available formats are:
5596 This is the default format. It produces a tarball containing all the
5597 specified binaries and symlinks.
5600 This produces a tarball that follows the
5601 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
5602 Docker Image Specification}. The ``repository name'' as it appears in
5603 the output of the @command{docker images} command is computed from
5604 package names passed on the command line or in the manifest file.
5607 This produces a SquashFS image containing all the specified binaries and
5608 symlinks, as well as empty mount points for virtual file systems like
5612 Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
5613 For that reason, @command{guix pack -f squashfs} always implies @code{-S
5614 /bin=bin}. Thus, your @command{guix pack} invocation must always start
5615 with something like:
5618 guix pack -f squashfs bash @dots{}
5621 If you forget the @code{bash} (or similar) package, @command{singularity
5622 run} and @command{singularity exec} will fail with an unhelpful ``no
5623 such file or directory'' message.
5627 @cindex relocatable binaries
5630 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
5631 anywhere in the file system hierarchy and run from there.
5633 When this option is passed once, the resulting binaries require support for
5634 @dfn{user namespaces} in the kernel Linux; when passed
5635 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
5636 PRoot support, can be thought of as the abbreviation of ``Really
5637 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to
5638 other techniques if user namespaces are unavailable, and essentially
5639 work anywhere---see below for the implications.
5641 For example, if you create a pack containing Bash with:
5644 guix pack -RR -S /mybin=bin bash
5648 ...@: you can copy that pack to a machine that lacks Guix, and from your
5649 home directory as a normal user, run:
5657 In that shell, if you type @code{ls /gnu/store}, you'll notice that
5658 @file{/gnu/store} shows up and contains all the dependencies of
5659 @code{bash}, even though the machine actually lacks @file{/gnu/store}
5660 altogether! That is probably the simplest way to deploy Guix-built
5661 software on a non-Guix machine.
5664 By default, relocatable binaries rely on the @dfn{user namespace} feature of
5665 the kernel Linux, which allows unprivileged users to mount or change root.
5666 Old versions of Linux did not support it, and some GNU/Linux distributions
5669 To produce relocatable binaries that work even in the absence of user
5670 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
5671 case, binaries will try user namespace support and fall back to another
5672 @dfn{execution engine} if user namespaces are not supported. The
5673 following execution engines are supported:
5677 Try user namespaces and fall back to PRoot if user namespaces are not
5678 supported (see below).
5681 Try user namespaces and fall back to Fakechroot if user namespaces are
5682 not supported (see below).
5685 Run the program through user namespaces and abort if they are not
5689 Run through PRoot. The @uref{https://proot-me.github.io/, PRoot} program
5690 provides the necessary
5691 support for file system virtualization. It achieves that by using the
5692 @code{ptrace} system call on the running program. This approach has the
5693 advantage to work without requiring special kernel support, but it incurs
5694 run-time overhead every time a system call is made.
5697 Run through Fakechroot. @uref{https://github.com/dex4er/fakechroot/,
5698 Fakechroot} virtualizes file system accesses by intercepting calls to C
5699 library functions such as @code{open}, @code{stat}, @code{exec}, and so
5700 on. Unlike PRoot, it incurs very little overhead. However, it does not
5701 always work: for example, some file system accesses made from within the
5702 C library are not intercepted, and file system accesses made @i{via}
5703 direct syscalls are not intercepted either, leading to erratic behavior.
5706 @vindex GUIX_EXECUTION_ENGINE
5707 When running a wrapped program, you can explicitly request one of the
5708 execution engines listed above by setting the
5709 @code{GUIX_EXECUTION_ENGINE} environment variable accordingly.
5712 @cindex entry point, for Docker images
5713 @item --entry-point=@var{command}
5714 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
5715 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
5716 support it. @var{command} must be relative to the profile contained in the
5719 The entry point specifies the command that tools like @code{docker run} or
5720 @code{singularity run} automatically start by default. For example, you can
5724 guix pack -f docker --entry-point=bin/guile guile
5727 The resulting pack can easily be loaded and @code{docker run} with no extra
5728 arguments will spawn @code{bin/guile}:
5731 docker load -i pack.tar.gz
5732 docker run @var{image-id}
5735 @item --expression=@var{expr}
5736 @itemx -e @var{expr}
5737 Consider the package @var{expr} evaluates to.
5739 This has the same purpose as the same-named option in @command{guix
5740 build} (@pxref{Additional Build Options, @option{--expression} in
5741 @command{guix build}}).
5743 @item --manifest=@var{file}
5744 @itemx -m @var{file}
5745 Use the packages contained in the manifest object returned by the Scheme
5746 code in @var{file}. This option can be repeated several times, in which
5747 case the manifests are concatenated.
5749 This has a similar purpose as the same-named option in @command{guix
5750 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
5751 same manifest files. It allows you to define a collection of packages
5752 once and use it both for creating profiles and for creating archives
5753 for use on machines that do not have Guix installed. Note that you can
5754 specify @emph{either} a manifest file @emph{or} a list of packages,
5757 @item --system=@var{system}
5758 @itemx -s @var{system}
5759 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
5760 the system type of the build host.
5762 @item --target=@var{triplet}
5763 @cindex cross-compilation
5764 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
5765 as @code{"aarch64-linux-gnu"} (@pxref{Specifying target triplets, GNU
5766 configuration triplets,, autoconf, Autoconf}).
5768 @item --compression=@var{tool}
5769 @itemx -C @var{tool}
5770 Compress the resulting tarball using @var{tool}---one of @code{gzip},
5771 @code{zstd}, @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no
5774 @item --symlink=@var{spec}
5775 @itemx -S @var{spec}
5776 Add the symlinks specified by @var{spec} to the pack. This option can
5777 appear several times.
5779 @var{spec} has the form @code{@var{source}=@var{target}}, where
5780 @var{source} is the symlink that will be created and @var{target} is the
5783 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
5784 symlink pointing to the @file{bin} sub-directory of the profile.
5786 @item --save-provenance
5787 Save provenance information for the packages passed on the command line.
5788 Provenance information includes the URL and commit of the channels in use
5791 Provenance information is saved in the
5792 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
5793 usual package metadata---the name and version of each package, their
5794 propagated inputs, and so on. It is useful information to the recipient of
5795 the pack, who then knows how the pack was (supposedly) obtained.
5797 This option is not enabled by default because, like timestamps, provenance
5798 information contributes nothing to the build process. In other words, there
5799 is an infinity of channel URLs and commit IDs that can lead to the same pack.
5800 Recording such ``silent'' metadata in the output thus potentially breaks the
5801 source-to-binary bitwise reproducibility property.
5803 @item --root=@var{file}
5804 @itemx -r @var{file}
5805 @cindex garbage collector root, for packs
5806 Make @var{file} a symlink to the resulting pack, and register it as a garbage
5809 @item --localstatedir
5810 @itemx --profile-name=@var{name}
5811 Include the ``local state directory'', @file{/var/guix}, in the resulting
5812 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
5813 profile---by default @var{name} is @code{guix-profile}, which corresponds to
5814 @file{~root/.guix-profile}.
5816 @file{/var/guix} contains the store database (@pxref{The Store}) as well
5817 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
5818 the pack means that the store is ``complete'' and manageable by Guix;
5819 not providing it pack means that the store is ``dead'': items cannot be
5820 added to it or removed from it after extraction of the pack.
5822 One use case for this is the Guix self-contained binary tarball
5823 (@pxref{Binary Installation}).
5827 Print the name of the derivation that builds the pack.
5830 Use the bootstrap binaries to build the pack. This option is only
5831 useful to Guix developers.
5834 In addition, @command{guix pack} supports all the common build options
5835 (@pxref{Common Build Options}) and all the package transformation
5836 options (@pxref{Package Transformation Options}).
5839 @node The GCC toolchain
5840 @section The GCC toolchain
5844 @cindex linker wrapper
5845 @cindex toolchain, for C development
5846 @cindex toolchain, for Fortran development
5848 If you need a complete toolchain for compiling and linking C or C++
5849 source code, use the @code{gcc-toolchain} package. This package
5850 provides a complete GCC toolchain for C/C++ development, including GCC
5851 itself, the GNU C Library (headers and binaries, plus debugging symbols
5852 in the @code{debug} output), Binutils, and a linker wrapper.
5854 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
5855 passed to the linker, add corresponding @code{-rpath} arguments, and
5856 invoke the actual linker with this new set of arguments. You can instruct the
5857 wrapper to refuse to link against libraries not in the store by setting the
5858 @env{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
5860 The package @code{gfortran-toolchain} provides a complete GCC toolchain
5861 for Fortran development. For other languages, please use
5862 @samp{guix search gcc toolchain} (@pxref{guix-search,, Invoking guix package}).
5865 @node Invoking guix git authenticate
5866 @section Invoking @command{guix git authenticate}
5868 The @command{guix git authenticate} command authenticates a Git checkout
5869 following the same rule as for channels (@pxref{channel-authentication,
5870 channel authentication}). That is, starting from a given commit, it
5871 ensures that all subsequent commits are signed by an OpenPGP key whose
5872 fingerprint appears in the @file{.guix-authorizations} file of its
5875 You will find this command useful if you maintain a channel. But in
5876 fact, this authentication mechanism is useful in a broader context, so
5877 you might want to use it for Git repositories that have nothing to do
5880 The general syntax is:
5883 guix git authenticate @var{commit} @var{signer} [@var{options}@dots{}]
5886 By default, this command authenticates the Git checkout in the current
5887 directory; it outputs nothing and exits with exit code zero on success
5888 and non-zero on failure. @var{commit} above denotes the first commit
5889 where authentication takes place, and @var{signer} is the OpenPGP
5890 fingerprint of public key used to sign @var{commit}. Together, they
5891 form a ``channel introduction'' (@pxref{channel-authentication, channel
5892 introduction}). The options below allow you to fine-tune the process.
5895 @item --repository=@var{directory}
5896 @itemx -r @var{directory}
5897 Open the Git repository in @var{directory} instead of the current
5900 @item --keyring=@var{reference}
5901 @itemx -k @var{reference}
5902 Load OpenPGP keyring from @var{reference}, the reference of a branch
5903 such as @code{origin/keyring} or @code{my-keyring}. The branch must
5904 contain OpenPGP public keys in @file{.key} files, either in binary form
5905 or ``ASCII-armored''. By default the keyring is loaded from the branch
5906 named @code{keyring}.
5909 Display commit signing statistics upon completion.
5911 @item --cache-key=@var{key}
5912 Previously-authenticated commits are cached in a file under
5913 @file{~/.cache/guix/authentication}. This option forces the cache to be
5914 stored in file @var{key} in that directory.
5916 @item --historical-authorizations=@var{file}
5917 By default, any commit whose parent commit(s) lack the
5918 @file{.guix-authorizations} file is considered inauthentic. In
5919 contrast, this option considers the authorizations in @var{file} for any
5920 commit that lacks @file{.guix-authorizations}. The format of @var{file}
5921 is the same as that of @file{.guix-authorizations}
5922 (@pxref{channel-authorizations, @file{.guix-authorizations} format}).
5926 @c *********************************************************************
5927 @node Programming Interface
5928 @chapter Programming Interface
5930 GNU Guix provides several Scheme programming interfaces (APIs) to
5931 define, build, and query packages. The first interface allows users to
5932 write high-level package definitions. These definitions refer to
5933 familiar packaging concepts, such as the name and version of a package,
5934 its build system, and its dependencies. These definitions can then be
5935 turned into concrete build actions.
5937 Build actions are performed by the Guix daemon, on behalf of users. In a
5938 standard setup, the daemon has write access to the store---the
5939 @file{/gnu/store} directory---whereas users do not. The recommended
5940 setup also has the daemon perform builds in chroots, under specific
5941 build users, to minimize interference with the rest of the system.
5944 Lower-level APIs are available to interact with the daemon and the
5945 store. To instruct the daemon to perform a build action, users actually
5946 provide it with a @dfn{derivation}. A derivation is a low-level
5947 representation of the build actions to be taken, and the environment in
5948 which they should occur---derivations are to package definitions what
5949 assembly is to C programs. The term ``derivation'' comes from the fact
5950 that build results @emph{derive} from them.
5952 This chapter describes all these APIs in turn, starting from high-level
5953 package definitions.
5956 * Package Modules:: Packages from the programmer's viewpoint.
5957 * Defining Packages:: Defining new packages.
5958 * Build Systems:: Specifying how packages are built.
5959 * The Store:: Manipulating the package store.
5960 * Derivations:: Low-level interface to package derivations.
5961 * The Store Monad:: Purely functional interface to the store.
5962 * G-Expressions:: Manipulating build expressions.
5963 * Invoking guix repl:: Programming Guix in Guile
5966 @node Package Modules
5967 @section Package Modules
5969 From a programming viewpoint, the package definitions of the
5970 GNU distribution are provided by Guile modules in the @code{(gnu packages
5971 @dots{})} name space@footnote{Note that packages under the @code{(gnu
5972 packages @dots{})} module name space are not necessarily ``GNU
5973 packages''. This module naming scheme follows the usual Guile module
5974 naming convention: @code{gnu} means that these modules are distributed
5975 as part of the GNU system, and @code{packages} identifies modules that
5976 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5977 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5978 module exports a variable named @code{emacs}, which is bound to a
5979 @code{<package>} object (@pxref{Defining Packages}).
5981 The @code{(gnu packages @dots{})} module name space is
5982 automatically scanned for packages by the command-line tools. For
5983 instance, when running @code{guix install emacs}, all the @code{(gnu
5984 packages @dots{})} modules are scanned until one that exports a package
5985 object whose name is @code{emacs} is found. This package search
5986 facility is implemented in the @code{(gnu packages)} module.
5988 @cindex customization, of packages
5989 @cindex package module search path
5990 Users can store package definitions in modules with different
5991 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
5992 name and module name must match. For instance, the @code{(my-packages
5993 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
5994 relative to the load path specified with @option{--load-path} or
5995 @env{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
5996 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
5997 these package definitions visible to the user interfaces:
6001 By adding the directory containing your package modules to the search path
6002 with the @code{-L} flag of @command{guix package} and other commands
6003 (@pxref{Common Build Options}), or by setting the @env{GUIX_PACKAGE_PATH}
6004 environment variable described below.
6007 By defining a @dfn{channel} and configuring @command{guix pull} so that it
6008 pulls from it. A channel is essentially a Git repository containing package
6009 modules. @xref{Channels}, for more information on how to define and use
6013 @env{GUIX_PACKAGE_PATH} works similarly to other search path variables:
6015 @defvr {Environment Variable} GUIX_PACKAGE_PATH
6016 This is a colon-separated list of directories to search for additional
6017 package modules. Directories listed in this variable take precedence
6018 over the own modules of the distribution.
6021 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
6022 each package is built based solely on other packages in the
6023 distribution. The root of this dependency graph is a small set of
6024 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
6025 bootstrap)} module. For more information on bootstrapping,
6026 @pxref{Bootstrapping}.
6028 @node Defining Packages
6029 @section Defining Packages
6031 The high-level interface to package definitions is implemented in the
6032 @code{(guix packages)} and @code{(guix build-system)} modules. As an
6033 example, the package definition, or @dfn{recipe}, for the GNU Hello
6034 package looks like this:
6037 (define-module (gnu packages hello)
6038 #:use-module (guix packages)
6039 #:use-module (guix download)
6040 #:use-module (guix build-system gnu)
6041 #:use-module (guix licenses)
6042 #:use-module (gnu packages gawk))
6044 (define-public hello
6050 (uri (string-append "mirror://gnu/hello/hello-" version
6054 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
6055 (build-system gnu-build-system)
6056 (arguments '(#:configure-flags '("--enable-silent-rules")))
6057 (inputs `(("gawk" ,gawk)))
6058 (synopsis "Hello, GNU world: An example GNU package")
6059 (description "Guess what GNU Hello prints!")
6060 (home-page "https://www.gnu.org/software/hello/")
6065 Without being a Scheme expert, the reader may have guessed the meaning
6066 of the various fields here. This expression binds the variable
6067 @code{hello} to a @code{<package>} object, which is essentially a record
6068 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
6069 This package object can be inspected using procedures found in the
6070 @code{(guix packages)} module; for instance, @code{(package-name hello)}
6071 returns---surprise!---@code{"hello"}.
6073 With luck, you may be able to import part or all of the definition of
6074 the package you are interested in from another repository, using the
6075 @code{guix import} command (@pxref{Invoking guix import}).
6077 In the example above, @var{hello} is defined in a module of its own,
6078 @code{(gnu packages hello)}. Technically, this is not strictly
6079 necessary, but it is convenient to do so: all the packages defined in
6080 modules under @code{(gnu packages @dots{})} are automatically known to
6081 the command-line tools (@pxref{Package Modules}).
6083 There are a few points worth noting in the above package definition:
6087 The @code{source} field of the package is an @code{<origin>} object
6088 (@pxref{origin Reference}, for the complete reference).
6089 Here, the @code{url-fetch} method from @code{(guix download)} is used,
6090 meaning that the source is a file to be downloaded over FTP or HTTP.
6092 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
6093 the GNU mirrors defined in @code{(guix download)}.
6095 The @code{sha256} field specifies the expected SHA256 hash of the file
6096 being downloaded. It is mandatory, and allows Guix to check the
6097 integrity of the file. The @code{(base32 @dots{})} form introduces the
6098 base32 representation of the hash. You can obtain this information with
6099 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
6100 hash} (@pxref{Invoking guix hash}).
6103 When needed, the @code{origin} form can also have a @code{patches} field
6104 listing patches to be applied, and a @code{snippet} field giving a
6105 Scheme expression to modify the source code.
6108 @cindex GNU Build System
6109 The @code{build-system} field specifies the procedure to build the
6110 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
6111 represents the familiar GNU Build System, where packages may be
6112 configured, built, and installed with the usual @code{./configure &&
6113 make && make check && make install} command sequence.
6116 The @code{arguments} field specifies options for the build system
6117 (@pxref{Build Systems}). Here it is interpreted by
6118 @var{gnu-build-system} as a request run @file{configure} with the
6119 @option{--enable-silent-rules} flag.
6125 What about these quote (@code{'}) characters? They are Scheme syntax to
6126 introduce a literal list; @code{'} is synonymous with @code{quote}.
6127 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
6128 for details. Here the value of the @code{arguments} field is a list of
6129 arguments passed to the build system down the road, as with @code{apply}
6130 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
6133 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
6134 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
6135 @code{#:configure-flags} is a keyword used to pass a keyword argument
6136 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
6140 The @code{inputs} field specifies inputs to the build process---i.e.,
6141 build-time or run-time dependencies of the package. Here, we define an
6142 input called @code{"gawk"} whose value is that of the @var{gawk}
6143 variable; @var{gawk} is itself bound to a @code{<package>} object.
6145 @cindex backquote (quasiquote)
6148 @cindex comma (unquote)
6152 @findex unquote-splicing
6153 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
6154 us to introduce a literal list in the @code{inputs} field, while
6155 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
6156 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
6159 Note that GCC, Coreutils, Bash, and other essential tools do not need to
6160 be specified as inputs here. Instead, @var{gnu-build-system} takes care
6161 of ensuring that they are present (@pxref{Build Systems}).
6163 However, any other dependencies need to be specified in the
6164 @code{inputs} field. Any dependency not specified here will simply be
6165 unavailable to the build process, possibly leading to a build failure.
6168 @xref{package Reference}, for a full description of possible fields.
6170 Once a package definition is in place, the
6171 package may actually be built using the @code{guix build} command-line
6172 tool (@pxref{Invoking guix build}), troubleshooting any build failures
6173 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
6174 package definition using the @command{guix edit} command
6175 (@pxref{Invoking guix edit}).
6176 @xref{Packaging Guidelines}, for
6177 more information on how to test package definitions, and
6178 @ref{Invoking guix lint}, for information on how to check a definition
6179 for style conformance.
6180 @vindex GUIX_PACKAGE_PATH
6181 Lastly, @pxref{Channels}, for information
6182 on how to extend the distribution by adding your own package definitions
6185 Finally, updating the package definition to a new upstream version
6186 can be partly automated by the @command{guix refresh} command
6187 (@pxref{Invoking guix refresh}).
6189 Behind the scenes, a derivation corresponding to the @code{<package>}
6190 object is first computed by the @code{package-derivation} procedure.
6191 That derivation is stored in a @file{.drv} file under @file{/gnu/store}.
6192 The build actions it prescribes may then be realized by using the
6193 @code{build-derivations} procedure (@pxref{The Store}).
6195 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
6196 Return the @code{<derivation>} object of @var{package} for @var{system}
6197 (@pxref{Derivations}).
6199 @var{package} must be a valid @code{<package>} object, and @var{system}
6200 must be a string denoting the target system type---e.g.,
6201 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
6202 must be a connection to the daemon, which operates on the store
6203 (@pxref{The Store}).
6207 @cindex cross-compilation
6208 Similarly, it is possible to compute a derivation that cross-builds a
6209 package for some other system:
6211 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
6212 @var{package} @var{target} [@var{system}]
6213 Return the @code{<derivation>} object of @var{package} cross-built from
6214 @var{system} to @var{target}.
6216 @var{target} must be a valid GNU triplet denoting the target hardware
6217 and operating system, such as @code{"aarch64-linux-gnu"}
6218 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
6221 @cindex package transformations
6222 @cindex input rewriting
6223 @cindex dependency tree rewriting
6224 Packages can be manipulated in arbitrary ways. An example of a useful
6225 transformation is @dfn{input rewriting}, whereby the dependency tree of
6226 a package is rewritten by replacing specific inputs by others:
6228 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
6229 [@var{rewrite-name}]
6230 Return a procedure that, when passed a package, replaces its direct and
6231 indirect dependencies (but not its implicit inputs) according to
6232 @var{replacements}. @var{replacements} is a list of package pairs; the
6233 first element of each pair is the package to replace, and the second one
6236 Optionally, @var{rewrite-name} is a one-argument procedure that takes
6237 the name of a package and returns its new name after rewrite.
6241 Consider this example:
6244 (define libressl-instead-of-openssl
6245 ;; This is a procedure to replace OPENSSL by LIBRESSL,
6247 (package-input-rewriting `((,openssl . ,libressl))))
6249 (define git-with-libressl
6250 (libressl-instead-of-openssl git))
6254 Here we first define a rewriting procedure that replaces @var{openssl}
6255 with @var{libressl}. Then we use it to define a @dfn{variant} of the
6256 @var{git} package that uses @var{libressl} instead of @var{openssl}.
6257 This is exactly what the @option{--with-input} command-line option does
6258 (@pxref{Package Transformation Options, @option{--with-input}}).
6260 The following variant of @code{package-input-rewriting} can match packages to
6261 be replaced by name rather than by identity.
6263 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
6264 Return a procedure that, given a package, applies the given @var{replacements} to
6265 all the package graph (excluding implicit inputs). @var{replacements} is a list of
6266 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
6267 @code{"guile@@2"}, and each procedure takes a matching package and returns a
6268 replacement for that package.
6271 The example above could be rewritten this way:
6274 (define libressl-instead-of-openssl
6275 ;; Replace all the packages called "openssl" with LibreSSL.
6276 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
6279 The key difference here is that, this time, packages are matched by spec and
6280 not by identity. In other words, any package in the graph that is called
6281 @code{openssl} will be replaced.
6283 A more generic procedure to rewrite a package dependency graph is
6284 @code{package-mapping}: it supports arbitrary changes to nodes in the
6287 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
6288 Return a procedure that, given a package, applies @var{proc} to all the packages
6289 depended on and returns the resulting package. The procedure stops recursion
6290 when @var{cut?} returns true for a given package.
6294 * package Reference:: The package data type.
6295 * origin Reference:: The origin data type.
6299 @node package Reference
6300 @subsection @code{package} Reference
6302 This section summarizes all the options available in @code{package}
6303 declarations (@pxref{Defining Packages}).
6305 @deftp {Data Type} package
6306 This is the data type representing a package recipe.
6310 The name of the package, as a string.
6312 @item @code{version}
6313 The version of the package, as a string.
6316 An object telling how the source code for the package should be
6317 acquired. Most of the time, this is an @code{origin} object, which
6318 denotes a file fetched from the Internet (@pxref{origin Reference}). It
6319 can also be any other ``file-like'' object such as a @code{local-file},
6320 which denotes a file from the local file system (@pxref{G-Expressions,
6321 @code{local-file}}).
6323 @item @code{build-system}
6324 The build system that should be used to build the package (@pxref{Build
6327 @item @code{arguments} (default: @code{'()})
6328 The arguments that should be passed to the build system. This is a
6329 list, typically containing sequential keyword-value pairs.
6331 @item @code{inputs} (default: @code{'()})
6332 @itemx @code{native-inputs} (default: @code{'()})
6333 @itemx @code{propagated-inputs} (default: @code{'()})
6334 @cindex inputs, of packages
6335 These fields list dependencies of the package. Each one is a list of
6336 tuples, where each tuple has a label for the input (a string) as its
6337 first element, a package, origin, or derivation as its second element,
6338 and optionally the name of the output thereof that should be used, which
6339 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
6340 more on package outputs). For example, the list below specifies three
6344 `(("libffi" ,libffi)
6345 ("libunistring" ,libunistring)
6346 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
6349 @cindex cross compilation, package dependencies
6350 The distinction between @code{native-inputs} and @code{inputs} is
6351 necessary when considering cross-compilation. When cross-compiling,
6352 dependencies listed in @code{inputs} are built for the @emph{target}
6353 architecture; conversely, dependencies listed in @code{native-inputs}
6354 are built for the architecture of the @emph{build} machine.
6356 @code{native-inputs} is typically used to list tools needed at
6357 build time, but not at run time, such as Autoconf, Automake, pkg-config,
6358 Gettext, or Bison. @command{guix lint} can report likely mistakes in
6359 this area (@pxref{Invoking guix lint}).
6361 @anchor{package-propagated-inputs}
6362 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
6363 specified packages will be automatically installed alongside the package
6364 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
6365 package}}, for information on how @command{guix package} deals with
6368 For example this is necessary when a C/C++ library needs headers of
6369 another library to compile, or when a pkg-config file refers to another
6370 one @i{via} its @code{Requires} field.
6372 Another example where @code{propagated-inputs} is useful is for languages
6373 that lack a facility to record the run-time search path akin to the
6374 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
6375 more. To ensure that libraries written in those languages can find
6376 library code they depend on at run time, run-time dependencies must be
6377 listed in @code{propagated-inputs} rather than @code{inputs}.
6379 @item @code{outputs} (default: @code{'("out")})
6380 The list of output names of the package. @xref{Packages with Multiple
6381 Outputs}, for typical uses of additional outputs.
6383 @item @code{native-search-paths} (default: @code{'()})
6384 @itemx @code{search-paths} (default: @code{'()})
6385 A list of @code{search-path-specification} objects describing
6386 search-path environment variables honored by the package.
6388 @item @code{replacement} (default: @code{#f})
6389 This must be either @code{#f} or a package object that will be used as a
6390 @dfn{replacement} for this package. @xref{Security Updates, grafts},
6393 @item @code{synopsis}
6394 A one-line description of the package.
6396 @item @code{description}
6397 A more elaborate description of the package.
6399 @item @code{license}
6400 @cindex license, of packages
6401 The license of the package; a value from @code{(guix licenses)},
6402 or a list of such values.
6404 @item @code{home-page}
6405 The URL to the home-page of the package, as a string.
6407 @item @code{supported-systems} (default: @code{%supported-systems})
6408 The list of systems supported by the package, as strings of the form
6409 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
6411 @item @code{location} (default: source location of the @code{package} form)
6412 The source location of the package. It is useful to override this when
6413 inheriting from another package, in which case this field is not
6414 automatically corrected.
6418 @deffn {Scheme Syntax} this-package
6419 When used in the @emph{lexical scope} of a package field definition, this
6420 identifier resolves to the package being defined.
6422 The example below shows how to add a package as a native input of itself when
6430 ;; When cross-compiled, Guile, for example, depends on
6431 ;; a native version of itself. Add it here.
6432 (native-inputs (if (%current-target-system)
6433 `(("self" ,this-package))
6437 It is an error to refer to @code{this-package} outside a package definition.
6440 @node origin Reference
6441 @subsection @code{origin} Reference
6443 This section summarizes all the options available in @code{origin}
6444 declarations (@pxref{Defining Packages}).
6446 @deftp {Data Type} origin
6447 This is the data type representing a source code origin.
6451 An object containing the URI of the source. The object type depends on
6452 the @code{method} (see below). For example, when using the
6453 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
6454 values are: a URL represented as a string, or a list thereof.
6457 A procedure that handles the URI.
6462 @item @var{url-fetch} from @code{(guix download)}
6463 download a file from the HTTP, HTTPS, or FTP URL specified in the
6467 @item @var{git-fetch} from @code{(guix git-download)}
6468 clone the Git version control repository, and check out the revision
6469 specified in the @code{uri} field as a @code{git-reference} object; a
6470 @code{git-reference} looks like this:
6474 (url "https://git.savannah.gnu.org/git/hello.git")
6480 A bytevector containing the SHA-256 hash of the source. This is
6481 equivalent to providing a @code{content-hash} SHA256 object in the
6482 @code{hash} field described below.
6485 The @code{content-hash} object of the source---see below for how to use
6486 @code{content-hash}.
6488 You can obtain this information using @code{guix download}
6489 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
6492 @item @code{file-name} (default: @code{#f})
6493 The file name under which the source code should be saved. When this is
6494 @code{#f}, a sensible default value will be used in most cases. In case
6495 the source is fetched from a URL, the file name from the URL will be
6496 used. For version control checkouts, it is recommended to provide the
6497 file name explicitly because the default is not very descriptive.
6499 @item @code{patches} (default: @code{'()})
6500 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
6501 file-like objects}) pointing to patches to be applied to the source.
6503 This list of patches must be unconditional. In particular, it cannot
6504 depend on the value of @code{%current-system} or
6505 @code{%current-target-system}.
6507 @item @code{snippet} (default: @code{#f})
6508 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
6509 in the source directory. This is a convenient way to modify the source,
6510 sometimes more convenient than a patch.
6512 @item @code{patch-flags} (default: @code{'("-p1")})
6513 A list of command-line flags that should be passed to the @code{patch}
6516 @item @code{patch-inputs} (default: @code{#f})
6517 Input packages or derivations to the patching process. When this is
6518 @code{#f}, the usual set of inputs necessary for patching are provided,
6519 such as GNU@tie{}Patch.
6521 @item @code{modules} (default: @code{'()})
6522 A list of Guile modules that should be loaded during the patching
6523 process and while running the code in the @code{snippet} field.
6525 @item @code{patch-guile} (default: @code{#f})
6526 The Guile package that should be used in the patching process. When
6527 this is @code{#f}, a sensible default is used.
6531 @deftp {Data Type} content-hash @var{value} [@var{algorithm}]
6532 Construct a content hash object for the given @var{algorithm}, and with
6533 @var{value} as its hash value. When @var{algorithm} is omitted, assume
6534 it is @code{sha256}.
6536 @var{value} can be a literal string, in which case it is base32-decoded,
6537 or it can be a bytevector.
6539 The following forms are all equivalent:
6542 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj")
6543 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"
6545 (content-hash (base32
6546 "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"))
6547 (content-hash (base64 "kkb+RPaP7uyMZmu4eXPVkM4BN8yhRd8BTHLslb6f/Rc=")
6551 Technically, @code{content-hash} is currently implemented as a macro.
6552 It performs sanity checks at macro-expansion time, when possible, such
6553 as ensuring that @var{value} has the right size for @var{algorithm}.
6557 @section Build Systems
6559 @cindex build system
6560 Each package definition specifies a @dfn{build system} and arguments for
6561 that build system (@pxref{Defining Packages}). This @code{build-system}
6562 field represents the build procedure of the package, as well as implicit
6563 dependencies of that build procedure.
6565 Build systems are @code{<build-system>} objects. The interface to
6566 create and manipulate them is provided by the @code{(guix build-system)}
6567 module, and actual build systems are exported by specific modules.
6569 @cindex bag (low-level package representation)
6570 Under the hood, build systems first compile package objects to
6571 @dfn{bags}. A @dfn{bag} is like a package, but with less
6572 ornamentation---in other words, a bag is a lower-level representation of
6573 a package, which includes all the inputs of that package, including some
6574 that were implicitly added by the build system. This intermediate
6575 representation is then compiled to a derivation (@pxref{Derivations}).
6577 Build systems accept an optional list of @dfn{arguments}. In package
6578 definitions, these are passed @i{via} the @code{arguments} field
6579 (@pxref{Defining Packages}). They are typically keyword arguments
6580 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
6581 Guile Reference Manual}). The value of these arguments is usually
6582 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
6583 by the daemon (@pxref{Derivations}).
6585 The main build system is @code{gnu-build-system}, which implements the
6586 standard build procedure for GNU and many other packages. It
6587 is provided by the @code{(guix build-system gnu)} module.
6589 @defvr {Scheme Variable} gnu-build-system
6590 @code{gnu-build-system} represents the GNU Build System, and variants
6591 thereof (@pxref{Configuration, configuration and makefile conventions,,
6592 standards, GNU Coding Standards}).
6594 @cindex build phases
6595 In a nutshell, packages using it are configured, built, and installed with
6596 the usual @code{./configure && make && make check && make install}
6597 command sequence. In practice, a few additional steps are often needed.
6598 All these steps are split up in separate @dfn{phases},
6599 notably@footnote{Please see the @code{(guix build gnu-build-system)}
6600 modules for more details about the build phases.}:
6604 Unpack the source tarball, and change the current directory to the
6605 extracted source tree. If the source is actually a directory, copy it
6606 to the build tree, and enter that directory.
6608 @item patch-source-shebangs
6609 Patch shebangs encountered in source files so they refer to the right
6610 store file names. For instance, this changes @code{#!/bin/sh} to
6611 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
6614 Run the @file{configure} script with a number of default options, such
6615 as @option{--prefix=/gnu/store/@dots{}}, as well as the options specified
6616 by the @code{#:configure-flags} argument.
6619 Run @code{make} with the list of flags specified with
6620 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
6621 (the default), build with @code{make -j}.
6624 Run @code{make check}, or some other target specified with
6625 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
6626 @code{#:parallel-tests?} argument is true (the default), run @code{make
6630 Run @code{make install} with the flags listed in @code{#:make-flags}.
6632 @item patch-shebangs
6633 Patch shebangs on the installed executable files.
6636 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
6637 is false), copying them to the @code{debug} output when available
6638 (@pxref{Installing Debugging Files}).
6641 @vindex %standard-phases
6642 The build-side module @code{(guix build gnu-build-system)} defines
6643 @code{%standard-phases} as the default list of build phases.
6644 @code{%standard-phases} is a list of symbol/procedure pairs, where the
6645 procedure implements the actual phase.
6647 The list of phases used for a particular package can be changed with the
6648 @code{#:phases} parameter. For instance, passing:
6651 #:phases (modify-phases %standard-phases (delete 'configure))
6654 means that all the phases described above will be used, except the
6655 @code{configure} phase.
6657 In addition, this build system ensures that the ``standard'' environment
6658 for GNU packages is available. This includes tools such as GCC, libc,
6659 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
6660 build-system gnu)} module for a complete list). We call these the
6661 @dfn{implicit inputs} of a package, because package definitions do not
6662 have to mention them.
6665 Other @code{<build-system>} objects are defined to support other
6666 conventions and tools used by free software packages. They inherit most
6667 of @code{gnu-build-system}, and differ mainly in the set of inputs
6668 implicitly added to the build process, and in the list of phases
6669 executed. Some of these build systems are listed below.
6671 @defvr {Scheme Variable} ant-build-system
6672 This variable is exported by @code{(guix build-system ant)}. It
6673 implements the build procedure for Java packages that can be built with
6674 @url{https://ant.apache.org/, Ant build tool}.
6676 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
6677 provided by the @code{icedtea} package to the set of inputs. Different
6678 packages can be specified with the @code{#:ant} and @code{#:jdk}
6679 parameters, respectively.
6681 When the original package does not provide a suitable Ant build file,
6682 the parameter @code{#:jar-name} can be used to generate a minimal Ant
6683 build file @file{build.xml} with tasks to build the specified jar
6684 archive. In this case the parameter @code{#:source-dir} can be used to
6685 specify the source sub-directory, defaulting to ``src''.
6687 The @code{#:main-class} parameter can be used with the minimal ant
6688 buildfile to specify the main class of the resulting jar. This makes the
6689 jar file executable. The @code{#:test-include} parameter can be used to
6690 specify the list of junit tests to run. It defaults to
6691 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
6692 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
6693 because abstract classes cannot be run as tests.
6695 The parameter @code{#:build-target} can be used to specify the Ant task
6696 that should be run during the @code{build} phase. By default the
6697 ``jar'' task will be run.
6701 @defvr {Scheme Variable} android-ndk-build-system
6702 @cindex Android distribution
6703 @cindex Android NDK build system
6704 This variable is exported by @code{(guix build-system android-ndk)}. It
6705 implements a build procedure for Android NDK (native development kit)
6706 packages using a Guix-specific build process.
6708 The build system assumes that packages install their public interface
6709 (header) files to the subdirectory @file{include} of the @code{out} output and
6710 their libraries to the subdirectory @file{lib} the @code{out} output.
6712 It's also assumed that the union of all the dependencies of a package
6713 has no conflicting files.
6715 For the time being, cross-compilation is not supported - so right now
6716 the libraries and header files are assumed to be host tools.
6720 @defvr {Scheme Variable} asdf-build-system/source
6721 @defvrx {Scheme Variable} asdf-build-system/sbcl
6722 @defvrx {Scheme Variable} asdf-build-system/ecl
6724 These variables, exported by @code{(guix build-system asdf)}, implement
6725 build procedures for Common Lisp packages using
6726 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
6727 definition facility for Common Lisp programs and libraries.
6729 The @code{asdf-build-system/source} system installs the packages in
6730 source form, and can be loaded using any common lisp implementation, via
6731 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
6732 systems in the format which a particular implementation understands.
6733 These build systems can also be used to produce executable programs, or
6734 lisp images which contain a set of packages pre-loaded.
6736 The build system uses naming conventions. For binary packages, the
6737 package name should be prefixed with the lisp implementation, such as
6738 @code{sbcl-} for @code{asdf-build-system/sbcl}.
6740 Additionally, the corresponding source package should be labeled using
6741 the same convention as python packages (see @ref{Python Modules}), using
6742 the @code{cl-} prefix.
6744 For binary packages, each system should be defined as a Guix package.
6745 If one package @code{origin} contains several systems, package variants
6746 can be created in order to build all the systems. Source packages,
6747 which use @code{asdf-build-system/source}, may contain several systems.
6749 In order to create executable programs and images, the build-side
6750 procedures @code{build-program} and @code{build-image} can be used.
6751 They should be called in a build phase after the @code{create-symlinks}
6752 phase, so that the system which was just built can be used within the
6753 resulting image. @code{build-program} requires a list of Common Lisp
6754 expressions to be passed as the @code{#:entry-program} argument.
6756 If the system is not defined within its own @file{.asd} file of the same
6757 name, then the @code{#:asd-file} parameter should be used to specify
6758 which file the system is defined in. Furthermore, if the package
6759 defines a system for its tests in a separate file, it will be loaded
6760 before the tests are run if it is specified by the
6761 @code{#:test-asd-file} parameter. If it is not set, the files
6762 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
6763 and @code{test.asd} will be tried if they exist.
6765 If for some reason the package must be named in a different way than the
6766 naming conventions suggest, the @code{#:asd-system-name} parameter can
6767 be used to specify the name of the system.
6771 @defvr {Scheme Variable} cargo-build-system
6772 @cindex Rust programming language
6773 @cindex Cargo (Rust build system)
6774 This variable is exported by @code{(guix build-system cargo)}. It
6775 supports builds of packages using Cargo, the build tool of the
6776 @uref{https://www.rust-lang.org, Rust programming language}.
6778 It adds @code{rustc} and @code{cargo} to the set of inputs.
6779 A different Rust package can be specified with the @code{#:rust} parameter.
6781 Regular cargo dependencies should be added to the package definition via the
6782 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
6783 spec can be a package or a source definition. Note that the spec must
6784 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
6785 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
6786 should be added to the package definition via the
6787 @code{#:cargo-development-inputs} parameter.
6789 In its @code{configure} phase, this build system will make any source inputs
6790 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
6791 parameters available to cargo. It will also remove an included
6792 @code{Cargo.lock} file to be recreated by @code{cargo} during the
6793 @code{build} phase. The @code{install} phase installs any crate the binaries
6794 if they are defined by the crate.
6798 @defvr {Scheme Variable} copy-build-system
6799 This variable is exported by @code{(guix build-system copy)}. It
6800 supports builds of simple packages that don't require much compiling,
6801 mostly just moving files around.
6803 It adds much of the @code{gnu-build-system} packages to the set of
6804 inputs. Because of this, the @code{copy-build-system} does not require
6805 all the boilerplate code often needed for the
6806 @code{trivial-build-system}.
6808 To further simplify the file installation process, an
6809 @code{#:install-plan} argument is exposed to let the packager specify
6810 which files go where. The install plan is a list of @code{(@var{source}
6811 @var{target} [@var{filters}])}. @var{filters} are optional.
6814 @item When @var{source} matches a file or directory without trailing slash, install it to @var{target}.
6816 @item If @var{target} has a trailing slash, install @var{source} basename beneath @var{target}.
6817 @item Otherwise install @var{source} as @var{target}.
6820 @item When @var{source} is a directory with a trailing slash, or when @var{filters} are used,
6821 the trailing slash of @var{target} is implied with the same meaning
6824 @item Without @var{filters}, install the full @var{source} @emph{content} to @var{target}.
6825 @item With @var{filters} among @code{#:include}, @code{#:include-regexp}, @code{#:exclude},
6826 @code{#:exclude-regexp}, only select files are installed depending on
6827 the filters. Each filters is specified by a list of strings.
6829 @item With @code{#:include}, install all the files which the path suffix matches
6830 at least one of the elements in the given list.
6831 @item With @code{#:include-regexp}, install all the files which the
6832 subpaths match at least one of the regular expressions in the given
6834 @item The @code{#:exclude} and @code{#:exclude-regexp} filters
6835 are the complement of their inclusion counterpart. Without @code{#:include} flags,
6836 install all files but those matching the exclusion filters.
6837 If both inclusions and exclusions are specified, the exclusions are done
6838 on top of the inclusions.
6841 In all cases, the paths relative to @var{source} are preserved within
6848 @item @code{("foo/bar" "share/my-app/")}: Install @file{bar} to @file{share/my-app/bar}.
6849 @item @code{("foo/bar" "share/my-app/baz")}: Install @file{bar} to @file{share/my-app/baz}.
6850 @item @code{("foo/" "share/my-app")}: Install the content of @file{foo} inside @file{share/my-app},
6851 e.g., install @file{foo/sub/file} to @file{share/my-app/sub/file}.
6852 @item @code{("foo/" "share/my-app" #:include ("sub/file"))}: Install only @file{foo/sub/file} to
6853 @file{share/my-app/sub/file}.
6854 @item @code{("foo/sub" "share/my-app" #:include ("file"))}: Install @file{foo/sub/file} to
6855 @file{share/my-app/file}.
6860 @cindex Clojure (programming language)
6861 @cindex simple Clojure build system
6862 @defvr {Scheme Variable} clojure-build-system
6863 This variable is exported by @code{(guix build-system clojure)}. It implements
6864 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
6865 using plain old @code{compile} in Clojure. Cross-compilation is not supported
6868 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
6869 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
6870 @code{#:zip} parameters, respectively.
6872 A list of source directories, test directories and jar names can be specified
6873 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
6874 parameters, respectively. Compile directory and main class can be specified
6875 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
6876 Other parameters are documented below.
6878 This build system is an extension of @code{ant-build-system}, but with the
6879 following phases changed:
6884 This phase calls @code{compile} in Clojure to compile source files and runs
6885 @command{jar} to create jars from both source files and compiled files
6886 according to the include list and exclude list specified in
6887 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
6888 has priority over the include list. These lists consist of symbols
6889 representing Clojure libraries or the special keyword @code{#:all} representing
6890 all Clojure libraries found under the source directories. The parameter
6891 @code{#:omit-source?} decides if source should be included into the jars.
6894 This phase runs tests according to the include list and exclude list specified
6895 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
6896 meanings are analogous to that of @code{#:aot-include} and
6897 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
6898 stands for all Clojure libraries found under the test directories. The
6899 parameter @code{#:tests?} decides if tests should be run.
6902 This phase installs all jars built previously.
6905 Apart from the above, this build system also contains an additional phase:
6910 This phase installs all top-level files with base name matching
6911 @code{%doc-regex}. A different regex can be specified with the
6912 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
6913 directories specified in @code{#:doc-dirs} are installed as well.
6917 @defvr {Scheme Variable} cmake-build-system
6918 This variable is exported by @code{(guix build-system cmake)}. It
6919 implements the build procedure for packages using the
6920 @url{https://www.cmake.org, CMake build tool}.
6922 It automatically adds the @code{cmake} package to the set of inputs.
6923 Which package is used can be specified with the @code{#:cmake}
6926 The @code{#:configure-flags} parameter is taken as a list of flags
6927 passed to the @command{cmake} command. The @code{#:build-type}
6928 parameter specifies in abstract terms the flags passed to the compiler;
6929 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
6930 debugging information''), which roughly means that code is compiled with
6931 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
6934 @defvr {Scheme Variable} dune-build-system
6935 This variable is exported by @code{(guix build-system dune)}. It
6936 supports builds of packages using @uref{https://dune.build/, Dune}, a build
6937 tool for the OCaml programming language. It is implemented as an extension
6938 of the @code{ocaml-build-system} which is described below. As such, the
6939 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
6942 It automatically adds the @code{dune} package to the set of inputs.
6943 Which package is used can be specified with the @code{#:dune}
6946 There is no @code{configure} phase because dune packages typically don't
6947 need to be configured. The @code{#:build-flags} parameter is taken as a
6948 list of flags passed to the @code{dune} command during the build.
6950 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
6951 command instead of the more recent @code{dune} command while building
6952 a package. Its default value is @code{#f}.
6954 The @code{#:package} parameter can be passed to specify a package name, which
6955 is useful when a package contains multiple packages and you want to build
6956 only one of them. This is equivalent to passing the @code{-p} argument to
6960 @defvr {Scheme Variable} go-build-system
6961 This variable is exported by @code{(guix build-system go)}. It
6962 implements a build procedure for Go packages using the standard
6963 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
6964 Go build mechanisms}.
6966 The user is expected to provide a value for the key @code{#:import-path}
6967 and, in some cases, @code{#:unpack-path}. The
6968 @url{https://golang.org/doc/code.html#ImportPaths, import path}
6969 corresponds to the file system path expected by the package's build
6970 scripts and any referring packages, and provides a unique way to
6971 refer to a Go package. It is typically based on a combination of the
6972 package source code's remote URI and file system hierarchy structure. In
6973 some cases, you will need to unpack the package's source code to a
6974 different directory structure than the one indicated by the import path,
6975 and @code{#:unpack-path} should be used in such cases.
6977 Packages that provide Go libraries should install their source code into
6978 the built output. The key @code{#:install-source?}, which defaults to
6979 @code{#t}, controls whether or not the source code is installed. It can
6980 be set to @code{#f} for packages that only provide executable files.
6983 @defvr {Scheme Variable} glib-or-gtk-build-system
6984 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
6985 is intended for use with packages making use of GLib or GTK+.
6987 This build system adds the following two phases to the ones defined by
6988 @code{gnu-build-system}:
6991 @item glib-or-gtk-wrap
6992 The phase @code{glib-or-gtk-wrap} ensures that programs in
6993 @file{bin/} are able to find GLib ``schemas'' and
6994 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
6995 modules}. This is achieved by wrapping the programs in launch scripts
6996 that appropriately set the @env{XDG_DATA_DIRS} and @env{GTK_PATH}
6997 environment variables.
6999 It is possible to exclude specific package outputs from that wrapping
7000 process by listing their names in the
7001 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
7002 when an output is known not to contain any GLib or GTK+ binaries, and
7003 where wrapping would gratuitously add a dependency of that output on
7006 @item glib-or-gtk-compile-schemas
7007 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
7008 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
7009 GSettings schemas} of GLib are compiled. Compilation is performed by the
7010 @command{glib-compile-schemas} program. It is provided by the package
7011 @code{glib:bin} which is automatically imported by the build system.
7012 The @code{glib} package providing @command{glib-compile-schemas} can be
7013 specified with the @code{#:glib} parameter.
7016 Both phases are executed after the @code{install} phase.
7019 @defvr {Scheme Variable} guile-build-system
7020 This build system is for Guile packages that consist exclusively of Scheme
7021 code and that are so lean that they don't even have a makefile, let alone a
7022 @file{configure} script. It compiles Scheme code using @command{guild
7023 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
7024 installs the @file{.scm} and @file{.go} files in the right place. It also
7025 installs documentation.
7027 This build system supports cross-compilation by using the
7028 @option{--target} option of @samp{guild compile}.
7030 Packages built with @code{guile-build-system} must provide a Guile package in
7031 their @code{native-inputs} field.
7034 @defvr {Scheme Variable} julia-build-system
7035 This variable is exported by @code{(guix build-system julia)}. It
7036 implements the build procedure used by @uref{https://julialang.org/,
7037 julia} packages, which essentially is similar to running @samp{julia -e
7038 'using Pkg; Pkg.add(package)'} in an environment where
7039 @env{JULIA_LOAD_PATH} contains the paths to all Julia package inputs.
7040 Tests are run not run.
7042 Julia packages require the source @code{file-name} to be the real name of the
7043 package, correctly capitalized.
7045 For packages requiring shared library dependencies, you may need to write the
7046 @file{/deps/deps.jl} file manually. It's usually a line of @code{const
7047 variable = /gnu/store/library.so} for each dependency, plus a void function
7048 @code{check_deps() = nothing}.
7050 Some older packages that aren't using @file{Package.toml} yet, will require
7051 this file to be created, too. The function @code{julia-create-package-toml}
7052 helps creating the file. You need to pass the outputs and the source of the
7053 package, it's name (the same as the @code{file-name} parameter), the package
7054 uuid, the package version, and a list of dependencies specified by their name
7058 @defvr {Scheme Variable} maven-build-system
7059 This variable is exported by @code{(guix build-system maven)}. It implements
7060 a build procedure for @uref{https://maven.apache.org, Maven} packages. Maven
7061 is a dependency and lifecycle management tool for Java. A user of Maven
7062 specifies dependencies and plugins in a @file{pom.xml} file that Maven reads.
7063 When Maven does not have one of the dependencies or plugins in its repository,
7064 it will download them and use them to build the package.
7066 The maven build system ensures that maven will not try to download any
7067 dependency by running in offline mode. Maven will fail if a dependency is
7068 missing. Before running Maven, the @file{pom.xml} (and subprojects) are
7069 modified to specify the version of dependencies and plugins that match the
7070 versions available in the guix build environment. Dependencies and plugins
7071 must be installed in the fake maven repository at @file{lib/m2}, and are
7072 symlinked into a proper repository before maven is run. Maven is instructed
7073 to use that repository for the build and installs built artifacts there.
7074 Changed files are copied to the @file{lib/m2} directory of the package output.
7076 You can specify a @file{pom.xml} file with the @code{#:pom-file} argument,
7077 or let the build system use the default @file{pom.xml} file in the sources.
7079 In case you need to specify a dependency's version manually, you can use the
7080 @code{#:local-packages} argument. It takes an association list where the key
7081 is the groupId of the package and its value is an association list where the
7082 key is the artifactId of the package and its value is the version you want to
7083 override in the @file{pom.xml}.
7085 Some packages use dependencies or plugins that are not useful at runtime nor
7086 at build time in Guix. You can alter the @file{pom.xml} file to remove them
7087 using the @code{#:exclude} argument. Its value is an association list where
7088 the key is the groupId of the plugin or dependency you want to remove, and
7089 the value is a list of artifactId you want to remove.
7091 You can override the default @code{jdk} and @code{maven} packages with the
7092 corresponding argument, @code{#:jdk} and @code{#:maven}.
7094 The @code{#:maven-plugins} argument is a list of maven plugins used during
7095 the build, with the same format as the @code{inputs} fields of the package
7096 declaration. Its default value is @code{(default-maven-plugins)} which is
7100 @defvr {Scheme Variable} minify-build-system
7101 This variable is exported by @code{(guix build-system minify)}. It
7102 implements a minification procedure for simple JavaScript packages.
7104 It adds @code{uglify-js} to the set of inputs and uses it to compress
7105 all JavaScript files in the @file{src} directory. A different minifier
7106 package can be specified with the @code{#:uglify-js} parameter, but it
7107 is expected that the package writes the minified code to the standard
7110 When the input JavaScript files are not all located in the @file{src}
7111 directory, the parameter @code{#:javascript-files} can be used to
7112 specify a list of file names to feed to the minifier.
7115 @defvr {Scheme Variable} ocaml-build-system
7116 This variable is exported by @code{(guix build-system ocaml)}. It implements
7117 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
7118 of choosing the correct set of commands to run for each package. OCaml
7119 packages can expect many different commands to be run. This build system will
7122 When the package has a @file{setup.ml} file present at the top-level, it will
7123 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
7124 @code{ocaml setup.ml -install}. The build system will assume that this file
7125 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
7126 care of setting the prefix and enabling tests if they are not disabled. You
7127 can pass configure and build flags with the @code{#:configure-flags} and
7128 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
7129 set of flags used to enable tests. The @code{#:use-make?} key can be used to
7130 bypass this system in the build and install phases.
7132 When the package has a @file{configure} file, it is assumed that it is a
7133 hand-made configure script that requires a different argument format than
7134 in the @code{gnu-build-system}. You can add more flags with the
7135 @code{#:configure-flags} key.
7137 When the package has a @file{Makefile} file (or @code{#:use-make?} is
7138 @code{#t}), it will be used and more flags can be passed to the build and
7139 install phases with the @code{#:make-flags} key.
7141 Finally, some packages do not have these files and use a somewhat standard
7142 location for its build system. In that case, the build system will run
7143 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
7144 providing the path to the required findlib module. Additional flags can
7145 be passed via the @code{#:build-flags} key. Install is taken care of by
7146 @command{opam-installer}. In this case, the @code{opam} package must
7147 be added to the @code{native-inputs} field of the package definition.
7149 Note that most OCaml packages assume they will be installed in the same
7150 directory as OCaml, which is not what we want in guix. In particular, they
7151 will install @file{.so} files in their module's directory, which is usually
7152 fine because it is in the OCaml compiler directory. In guix though, these
7153 libraries cannot be found and we use @env{CAML_LD_LIBRARY_PATH}. This
7154 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
7155 @file{.so} libraries should be installed.
7158 @defvr {Scheme Variable} python-build-system
7159 This variable is exported by @code{(guix build-system python)}. It
7160 implements the more or less standard build procedure used by Python
7161 packages, which consists in running @code{python setup.py build} and
7162 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
7164 For packages that install stand-alone Python programs under @code{bin/},
7165 it takes care of wrapping these programs so that their @env{PYTHONPATH}
7166 environment variable points to all the Python libraries they depend on.
7168 Which Python package is used to perform the build can be specified with
7169 the @code{#:python} parameter. This is a useful way to force a package
7170 to be built for a specific version of the Python interpreter, which
7171 might be necessary if the package is only compatible with a single
7172 interpreter version.
7174 By default guix calls @code{setup.py} under control of
7175 @code{setuptools}, much like @command{pip} does. Some packages are not
7176 compatible with setuptools (and pip), thus you can disable this by
7177 setting the @code{#:use-setuptools?} parameter to @code{#f}.
7180 @defvr {Scheme Variable} perl-build-system
7181 This variable is exported by @code{(guix build-system perl)}. It
7182 implements the standard build procedure for Perl packages, which either
7183 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
7184 followed by @code{Build} and @code{Build install}; or in running
7185 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
7186 @code{make} and @code{make install}, depending on which of
7187 @code{Build.PL} or @code{Makefile.PL} is present in the package
7188 distribution. Preference is given to the former if both @code{Build.PL}
7189 and @code{Makefile.PL} exist in the package distribution. This
7190 preference can be reversed by specifying @code{#t} for the
7191 @code{#:make-maker?} parameter.
7193 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
7194 passes flags specified by the @code{#:make-maker-flags} or
7195 @code{#:module-build-flags} parameter, respectively.
7197 Which Perl package is used can be specified with @code{#:perl}.
7200 @defvr {Scheme Variable} qt-build-system
7201 This variable is exported by @code{(guix build-system qt)}. It
7202 is intended for use with applications using Qt or KDE.
7204 This build system adds the following two phases to the ones defined by
7205 @code{cmake-build-system}:
7209 The phase @code{check-setup} prepares the environment for running
7210 the checks as commonly used by Qt test programs.
7211 For now this only sets some environment variables:
7212 @code{QT_QPA_PLATFORM=offscreen},
7213 @code{DBUS_FATAL_WARNINGS=0} and
7214 @code{CTEST_OUTPUT_ON_FAILURE=1}.
7216 This phase is added before the @code{check} phase.
7217 It's a separate phase to ease adjusting if necessary.
7220 The phase @code{qt-wrap}
7221 searches for Qt5 plugin paths, QML paths and some XDG in the inputs
7222 and output. In case some path is found, all programs in the output's
7223 @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
7224 are wrapped in scripts defining the necessary environment variables.
7226 It is possible to exclude specific package outputs from that wrapping process
7227 by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
7228 This is useful when an output is known not to contain any Qt binaries, and
7229 where wrapping would gratuitously add a dependency of that output on Qt, KDE,
7232 This phase is added after the @code{install} phase.
7236 @defvr {Scheme Variable} r-build-system
7237 This variable is exported by @code{(guix build-system r)}. It
7238 implements the build procedure used by @uref{https://r-project.org, R}
7239 packages, which essentially is little more than running @samp{R CMD
7240 INSTALL --library=/gnu/store/@dots{}} in an environment where
7241 @env{R_LIBS_SITE} contains the paths to all R package inputs. Tests are
7242 run after installation using the R function
7243 @code{tools::testInstalledPackage}.
7246 @defvr {Scheme Variable} rakudo-build-system
7247 This variable is exported by @code{(guix build-system rakudo)}. It
7248 implements the build procedure used by @uref{https://rakudo.org/,
7249 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
7250 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
7251 installs the binaries, library files and the resources, as well as wrap
7252 the files under the @code{bin/} directory. Tests can be skipped by
7253 passing @code{#f} to the @code{tests?} parameter.
7255 Which rakudo package is used can be specified with @code{rakudo}.
7256 Which perl6-tap-harness package used for the tests can be specified with
7257 @code{#:prove6} or removed by passing @code{#f} to the
7258 @code{with-prove6?} parameter.
7259 Which perl6-zef package used for tests and installing can be specified
7260 with @code{#:zef} or removed by passing @code{#f} to the
7261 @code{with-zef?} parameter.
7264 @defvr {Scheme Variable} texlive-build-system
7265 This variable is exported by @code{(guix build-system texlive)}. It is
7266 used to build TeX packages in batch mode with a specified engine. The
7267 build system sets the @env{TEXINPUTS} variable to find all TeX source
7268 files in the inputs.
7270 By default it runs @code{luatex} on all files ending on @code{ins}. A
7271 different engine and format can be specified with the
7272 @code{#:tex-format} argument. Different build targets can be specified
7273 with the @code{#:build-targets} argument, which expects a list of file
7274 names. The build system adds only @code{texlive-bin} and
7275 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
7276 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
7277 and @code{#:texlive-latex-base}, respectively.
7279 The @code{#:tex-directory} parameter tells the build system where to
7280 install the built files under the texmf tree.
7283 @defvr {Scheme Variable} ruby-build-system
7284 This variable is exported by @code{(guix build-system ruby)}. It
7285 implements the RubyGems build procedure used by Ruby packages, which
7286 involves running @code{gem build} followed by @code{gem install}.
7288 The @code{source} field of a package that uses this build system
7289 typically references a gem archive, since this is the format that Ruby
7290 developers use when releasing their software. The build system unpacks
7291 the gem archive, potentially patches the source, runs the test suite,
7292 repackages the gem, and installs it. Additionally, directories and
7293 tarballs may be referenced to allow building unreleased gems from Git or
7294 a traditional source release tarball.
7296 Which Ruby package is used can be specified with the @code{#:ruby}
7297 parameter. A list of additional flags to be passed to the @command{gem}
7298 command can be specified with the @code{#:gem-flags} parameter.
7301 @defvr {Scheme Variable} waf-build-system
7302 This variable is exported by @code{(guix build-system waf)}. It
7303 implements a build procedure around the @code{waf} script. The common
7304 phases---@code{configure}, @code{build}, and @code{install}---are
7305 implemented by passing their names as arguments to the @code{waf}
7308 The @code{waf} script is executed by the Python interpreter. Which
7309 Python package is used to run the script can be specified with the
7310 @code{#:python} parameter.
7313 @defvr {Scheme Variable} scons-build-system
7314 This variable is exported by @code{(guix build-system scons)}. It
7315 implements the build procedure used by the SCons software construction
7316 tool. This build system runs @code{scons} to build the package,
7317 @code{scons test} to run tests, and then @code{scons install} to install
7320 Additional flags to be passed to @code{scons} can be specified with the
7321 @code{#:scons-flags} parameter. The default build and install targets
7322 can be overridden with @code{#:build-targets} and
7323 @code{#:install-targets} respectively. The version of Python used to
7324 run SCons can be specified by selecting the appropriate SCons package
7325 with the @code{#:scons} parameter.
7328 @defvr {Scheme Variable} haskell-build-system
7329 This variable is exported by @code{(guix build-system haskell)}. It
7330 implements the Cabal build procedure used by Haskell packages, which
7331 involves running @code{runhaskell Setup.hs configure
7332 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
7333 Instead of installing the package by running @code{runhaskell Setup.hs
7334 install}, to avoid trying to register libraries in the read-only
7335 compiler store directory, the build system uses @code{runhaskell
7336 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
7337 addition, the build system generates the package documentation by
7338 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
7339 is passed. Optional Haddock parameters can be passed with the help of
7340 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
7341 not found, the build system looks for @code{Setup.lhs} instead.
7343 Which Haskell compiler is used can be specified with the @code{#:haskell}
7344 parameter which defaults to @code{ghc}.
7347 @defvr {Scheme Variable} dub-build-system
7348 This variable is exported by @code{(guix build-system dub)}. It
7349 implements the Dub build procedure used by D packages, which
7350 involves running @code{dub build} and @code{dub run}.
7351 Installation is done by copying the files manually.
7353 Which D compiler is used can be specified with the @code{#:ldc}
7354 parameter which defaults to @code{ldc}.
7357 @defvr {Scheme Variable} emacs-build-system
7358 This variable is exported by @code{(guix build-system emacs)}. It
7359 implements an installation procedure similar to the packaging system
7360 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
7362 It first creates the @code{@code{package}-autoloads.el} file, then it
7363 byte compiles all Emacs Lisp files. Differently from the Emacs
7364 packaging system, the Info documentation files are moved to the standard
7365 documentation directory and the @file{dir} file is deleted. The Elisp
7366 package files are installed directly under @file{share/emacs/site-lisp}.
7369 @defvr {Scheme Variable} font-build-system
7370 This variable is exported by @code{(guix build-system font)}. It
7371 implements an installation procedure for font packages where upstream
7372 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
7373 need to be copied into place. It copies font files to standard
7374 locations in the output directory.
7377 @defvr {Scheme Variable} meson-build-system
7378 This variable is exported by @code{(guix build-system meson)}. It
7379 implements the build procedure for packages that use
7380 @url{https://mesonbuild.com, Meson} as their build system.
7382 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
7383 of inputs, and they can be changed with the parameters @code{#:meson}
7384 and @code{#:ninja} if needed. The default Meson is
7385 @code{meson-for-build}, which is special because it doesn't clear the
7386 @code{RUNPATH} of binaries and libraries when they are installed.
7388 This build system is an extension of @code{gnu-build-system}, but with the
7389 following phases changed to some specific for Meson:
7394 The phase runs @code{meson} with the flags specified in
7395 @code{#:configure-flags}. The flag @option{--buildtype} is always set to
7396 @code{debugoptimized} unless something else is specified in
7397 @code{#:build-type}.
7400 The phase runs @code{ninja} to build the package in parallel by default, but
7401 this can be changed with @code{#:parallel-build?}.
7404 The phase runs @code{ninja} with the target specified in @code{#:test-target},
7405 which is @code{"test"} by default.
7408 The phase runs @code{ninja install} and can not be changed.
7411 Apart from that, the build system also adds the following phases:
7416 This phase ensures that all binaries can find the libraries they need.
7417 It searches for required libraries in subdirectories of the package being
7418 built, and adds those to @code{RUNPATH} where needed. It also removes
7419 references to libraries left over from the build phase by
7420 @code{meson-for-build}, such as test dependencies, that aren't actually
7421 required for the program to run.
7423 @item glib-or-gtk-wrap
7424 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
7425 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
7427 @item glib-or-gtk-compile-schemas
7428 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
7429 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
7433 @defvr {Scheme Variable} linux-module-build-system
7434 @code{linux-module-build-system} allows building Linux kernel modules.
7436 @cindex build phases
7437 This build system is an extension of @code{gnu-build-system}, but with the
7438 following phases changed:
7443 This phase configures the environment so that the Linux kernel's Makefile
7444 can be used to build the external kernel module.
7447 This phase uses the Linux kernel's Makefile in order to build the external
7451 This phase uses the Linux kernel's Makefile in order to install the external
7455 It is possible and useful to specify the Linux kernel to use for building
7456 the module (in the @code{arguments} form of a package using the
7457 @code{linux-module-build-system}, use the key @code{#:linux} to specify it).
7460 @defvr {Scheme Variable} node-build-system
7461 This variable is exported by @code{(guix build-system node)}. It
7462 implements the build procedure used by @uref{https://nodejs.org,
7463 Node.js}, which implements an approximation of the @code{npm install}
7464 command, followed by an @code{npm test} command.
7466 Which Node.js package is used to interpret the @code{npm} commands can
7467 be specified with the @code{#:node} parameter which defaults to
7471 Lastly, for packages that do not need anything as sophisticated, a
7472 ``trivial'' build system is provided. It is trivial in the sense that
7473 it provides basically no support: it does not pull any implicit inputs,
7474 and does not have a notion of build phases.
7476 @defvr {Scheme Variable} trivial-build-system
7477 This variable is exported by @code{(guix build-system trivial)}.
7479 This build system requires a @code{#:builder} argument. This argument
7480 must be a Scheme expression that builds the package output(s)---as
7481 with @code{build-expression->derivation} (@pxref{Derivations,
7482 @code{build-expression->derivation}}).
7492 Conceptually, the @dfn{store} is the place where derivations that have
7493 been built successfully are stored---by default, @file{/gnu/store}.
7494 Sub-directories in the store are referred to as @dfn{store items} or
7495 sometimes @dfn{store paths}. The store has an associated database that
7496 contains information such as the store paths referred to by each store
7497 path, and the list of @emph{valid} store items---results of successful
7498 builds. This database resides in @file{@var{localstatedir}/guix/db},
7499 where @var{localstatedir} is the state directory specified @i{via}
7500 @option{--localstatedir} at configure time, usually @file{/var}.
7502 The store is @emph{always} accessed by the daemon on behalf of its clients
7503 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
7504 connect to the daemon over a Unix-domain socket, send requests to it,
7505 and read the result---these are remote procedure calls, or RPCs.
7508 Users must @emph{never} modify files under @file{/gnu/store} directly.
7509 This would lead to inconsistencies and break the immutability
7510 assumptions of Guix's functional model (@pxref{Introduction}).
7512 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
7513 how to check the integrity of the store and attempt recovery from
7514 accidental modifications.
7517 The @code{(guix store)} module provides procedures to connect to the
7518 daemon, and to perform RPCs. These are described below. By default,
7519 @code{open-connection}, and thus all the @command{guix} commands,
7520 connect to the local daemon or to the URI specified by the
7521 @env{GUIX_DAEMON_SOCKET} environment variable.
7523 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
7524 When set, the value of this variable should be a file name or a URI
7525 designating the daemon endpoint. When it is a file name, it denotes a
7526 Unix-domain socket to connect to. In addition to file names, the
7527 supported URI schemes are:
7532 These are for Unix-domain sockets.
7533 @code{file:///var/guix/daemon-socket/socket} is equivalent to
7534 @file{/var/guix/daemon-socket/socket}.
7537 @cindex daemon, remote access
7538 @cindex remote access to the daemon
7539 @cindex daemon, cluster setup
7540 @cindex clusters, daemon setup
7541 These URIs denote connections over TCP/IP, without encryption nor
7542 authentication of the remote host. The URI must specify the host name
7543 and optionally a port number (by default port 44146 is used):
7546 guix://master.guix.example.org:1234
7549 This setup is suitable on local networks, such as clusters, where only
7550 trusted nodes may connect to the build daemon at
7551 @code{master.guix.example.org}.
7553 The @option{--listen} option of @command{guix-daemon} can be used to
7554 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
7555 @option{--listen}}).
7558 @cindex SSH access to build daemons
7559 These URIs allow you to connect to a remote daemon over SSH. This
7560 feature requires Guile-SSH (@pxref{Requirements}) and a working
7561 @command{guile} binary in @env{PATH} on the destination machine. It
7562 supports public key and GSSAPI authentication. A typical URL might look
7566 ssh://charlie@@guix.example.org:22
7569 As for @command{guix copy}, the usual OpenSSH client configuration files
7570 are honored (@pxref{Invoking guix copy}).
7573 Additional URI schemes may be supported in the future.
7575 @c XXX: Remove this note when the protocol incurs fewer round trips
7576 @c and when (guix derivations) no longer relies on file system access.
7578 The ability to connect to remote build daemons is considered
7579 experimental as of @value{VERSION}. Please get in touch with us to
7580 share any problems or suggestions you may have (@pxref{Contributing}).
7584 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
7585 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
7586 @var{reserve-space?} is true, instruct it to reserve a little bit of
7587 extra space on the file system so that the garbage collector can still
7588 operate should the disk become full. Return a server object.
7590 @var{file} defaults to @code{%default-socket-path}, which is the normal
7591 location given the options that were passed to @command{configure}.
7594 @deffn {Scheme Procedure} close-connection @var{server}
7595 Close the connection to @var{server}.
7598 @defvr {Scheme Variable} current-build-output-port
7599 This variable is bound to a SRFI-39 parameter, which refers to the port
7600 where build and error logs sent by the daemon should be written.
7603 Procedures that make RPCs all take a server object as their first
7606 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
7607 @cindex invalid store items
7608 Return @code{#t} when @var{path} designates a valid store item and
7609 @code{#f} otherwise (an invalid item may exist on disk but still be
7610 invalid, for instance because it is the result of an aborted or failed
7613 A @code{&store-protocol-error} condition is raised if @var{path} is not
7614 prefixed by the store directory (@file{/gnu/store}).
7617 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
7618 Add @var{text} under file @var{name} in the store, and return its store
7619 path. @var{references} is the list of store paths referred to by the
7620 resulting store path.
7623 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
7625 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
7626 file names, or derivation/output pairs, using the specified
7627 @var{mode}---@code{(build-mode normal)} by default.
7630 Note that the @code{(guix monads)} module provides a monad as well as
7631 monadic versions of the above procedures, with the goal of making it
7632 more convenient to work with code that accesses the store (@pxref{The
7636 @i{This section is currently incomplete.}
7639 @section Derivations
7642 Low-level build actions and the environment in which they are performed
7643 are represented by @dfn{derivations}. A derivation contains the
7644 following pieces of information:
7648 The outputs of the derivation---derivations produce at least one file or
7649 directory in the store, but may produce more.
7652 @cindex build-time dependencies
7653 @cindex dependencies, build-time
7654 The inputs of the derivations---i.e., its build-time dependencies---which may
7655 be other derivations or plain files in the store (patches, build scripts,
7659 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
7662 The file name of a build script in the store, along with the arguments
7666 A list of environment variables to be defined.
7670 @cindex derivation path
7671 Derivations allow clients of the daemon to communicate build actions to
7672 the store. They exist in two forms: as an in-memory representation,
7673 both on the client- and daemon-side, and as files in the store whose
7674 name end in @file{.drv}---these files are referred to as @dfn{derivation
7675 paths}. Derivations paths can be passed to the @code{build-derivations}
7676 procedure to perform the build actions they prescribe (@pxref{The
7679 @cindex fixed-output derivations
7680 Operations such as file downloads and version-control checkouts for
7681 which the expected content hash is known in advance are modeled as
7682 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
7683 of a fixed-output derivation are independent of its inputs---e.g., a
7684 source code download produces the same result regardless of the download
7685 method and tools being used.
7688 @cindex run-time dependencies
7689 @cindex dependencies, run-time
7690 The outputs of derivations---i.e., the build results---have a set of
7691 @dfn{references}, as reported by the @code{references} RPC or the
7692 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
7693 are the set of run-time dependencies of the build results. References are a
7694 subset of the inputs of the derivation; this subset is automatically computed
7695 by the build daemon by scanning all the files in the outputs.
7697 The @code{(guix derivations)} module provides a representation of
7698 derivations as Scheme objects, along with procedures to create and
7699 otherwise manipulate derivations. The lowest-level primitive to create
7700 a derivation is the @code{derivation} procedure:
7702 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
7703 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
7704 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
7705 [#:system (%current-system)] [#:references-graphs #f] @
7706 [#:allowed-references #f] [#:disallowed-references #f] @
7707 [#:leaked-env-vars #f] [#:local-build? #f] @
7708 [#:substitutable? #t] [#:properties '()]
7709 Build a derivation with the given arguments, and return the resulting
7710 @code{<derivation>} object.
7712 When @var{hash} and @var{hash-algo} are given, a
7713 @dfn{fixed-output derivation} is created---i.e., one whose result is
7714 known in advance, such as a file download. If, in addition,
7715 @var{recursive?} is true, then that fixed output may be an executable
7716 file or a directory and @var{hash} must be the hash of an archive
7717 containing this output.
7719 When @var{references-graphs} is true, it must be a list of file
7720 name/store path pairs. In that case, the reference graph of each store
7721 path is exported in the build environment in the corresponding file, in
7722 a simple text format.
7724 When @var{allowed-references} is true, it must be a list of store items
7725 or outputs that the derivation's output may refer to. Likewise,
7726 @var{disallowed-references}, if true, must be a list of things the
7727 outputs may @emph{not} refer to.
7729 When @var{leaked-env-vars} is true, it must be a list of strings
7730 denoting environment variables that are allowed to ``leak'' from the
7731 daemon's environment to the build environment. This is only applicable
7732 to fixed-output derivations---i.e., when @var{hash} is true. The main
7733 use is to allow variables such as @code{http_proxy} to be passed to
7734 derivations that download files.
7736 When @var{local-build?} is true, declare that the derivation is not a
7737 good candidate for offloading and should rather be built locally
7738 (@pxref{Daemon Offload Setup}). This is the case for small derivations
7739 where the costs of data transfers would outweigh the benefits.
7741 When @var{substitutable?} is false, declare that substitutes of the
7742 derivation's output should not be used (@pxref{Substitutes}). This is
7743 useful, for instance, when building packages that capture details of the
7744 host CPU instruction set.
7746 @var{properties} must be an association list describing ``properties'' of the
7747 derivation. It is kept as-is, uninterpreted, in the derivation.
7751 Here's an example with a shell script as its builder, assuming
7752 @var{store} is an open connection to the daemon, and @var{bash} points
7753 to a Bash executable in the store:
7756 (use-modules (guix utils)
7760 (let ((builder ; add the Bash script to the store
7761 (add-text-to-store store "my-builder.sh"
7762 "echo hello world > $out\n" '())))
7763 (derivation store "foo"
7764 bash `("-e" ,builder)
7765 #:inputs `((,bash) (,builder))
7766 #:env-vars '(("HOME" . "/homeless"))))
7767 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
7770 As can be guessed, this primitive is cumbersome to use directly. A
7771 better approach is to write build scripts in Scheme, of course! The
7772 best course of action for that is to write the build code as a
7773 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
7774 information, @pxref{G-Expressions}.
7776 Once upon a time, @code{gexp->derivation} did not exist and constructing
7777 derivations with build code written in Scheme was achieved with
7778 @code{build-expression->derivation}, documented below. This procedure
7779 is now deprecated in favor of the much nicer @code{gexp->derivation}.
7781 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
7782 @var{name} @var{exp} @
7783 [#:system (%current-system)] [#:inputs '()] @
7784 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
7785 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7786 [#:references-graphs #f] [#:allowed-references #f] @
7787 [#:disallowed-references #f] @
7788 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
7789 Return a derivation that executes Scheme expression @var{exp} as a
7790 builder for derivation @var{name}. @var{inputs} must be a list of
7791 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
7792 @code{"out"} is assumed. @var{modules} is a list of names of Guile
7793 modules from the current search path to be copied in the store,
7794 compiled, and made available in the load path during the execution of
7795 @var{exp}---e.g., @code{((guix build utils) (guix build
7796 gnu-build-system))}.
7798 @var{exp} is evaluated in an environment where @code{%outputs} is bound
7799 to a list of output/path pairs, and where @code{%build-inputs} is bound
7800 to a list of string/output-path pairs made from @var{inputs}.
7801 Optionally, @var{env-vars} is a list of string pairs specifying the name
7802 and value of environment variables visible to the builder. The builder
7803 terminates by passing the result of @var{exp} to @code{exit}; thus, when
7804 @var{exp} returns @code{#f}, the build is considered to have failed.
7806 @var{exp} is built using @var{guile-for-build} (a derivation). When
7807 @var{guile-for-build} is omitted or is @code{#f}, the value of the
7808 @code{%guile-for-build} fluid is used instead.
7810 See the @code{derivation} procedure for the meaning of
7811 @var{references-graphs}, @var{allowed-references},
7812 @var{disallowed-references}, @var{local-build?}, and
7813 @var{substitutable?}.
7817 Here's an example of a single-output derivation that creates a directory
7818 containing one file:
7821 (let ((builder '(let ((out (assoc-ref %outputs "out")))
7822 (mkdir out) ; create /gnu/store/@dots{}-goo
7823 (call-with-output-file (string-append out "/test")
7825 (display '(hello guix) p))))))
7826 (build-expression->derivation store "goo" builder))
7828 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
7832 @node The Store Monad
7833 @section The Store Monad
7837 The procedures that operate on the store described in the previous
7838 sections all take an open connection to the build daemon as their first
7839 argument. Although the underlying model is functional, they either have
7840 side effects or depend on the current state of the store.
7842 The former is inconvenient: the connection to the build daemon has to be
7843 carried around in all those functions, making it impossible to compose
7844 functions that do not take that parameter with functions that do. The
7845 latter can be problematic: since store operations have side effects
7846 and/or depend on external state, they have to be properly sequenced.
7848 @cindex monadic values
7849 @cindex monadic functions
7850 This is where the @code{(guix monads)} module comes in. This module
7851 provides a framework for working with @dfn{monads}, and a particularly
7852 useful monad for our uses, the @dfn{store monad}. Monads are a
7853 construct that allows two things: associating ``context'' with values
7854 (in our case, the context is the store), and building sequences of
7855 computations (here computations include accesses to the store). Values
7856 in a monad---values that carry this additional context---are called
7857 @dfn{monadic values}; procedures that return such values are called
7858 @dfn{monadic procedures}.
7860 Consider this ``normal'' procedure:
7863 (define (sh-symlink store)
7864 ;; Return a derivation that symlinks the 'bash' executable.
7865 (let* ((drv (package-derivation store bash))
7866 (out (derivation->output-path drv))
7867 (sh (string-append out "/bin/bash")))
7868 (build-expression->derivation store "sh"
7869 `(symlink ,sh %output))))
7872 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
7873 as a monadic function:
7876 (define (sh-symlink)
7877 ;; Same, but return a monadic value.
7878 (mlet %store-monad ((drv (package->derivation bash)))
7879 (gexp->derivation "sh"
7880 #~(symlink (string-append #$drv "/bin/bash")
7884 There are several things to note in the second version: the @code{store}
7885 parameter is now implicit and is ``threaded'' in the calls to the
7886 @code{package->derivation} and @code{gexp->derivation} monadic
7887 procedures, and the monadic value returned by @code{package->derivation}
7888 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
7890 As it turns out, the call to @code{package->derivation} can even be
7891 omitted since it will take place implicitly, as we will see later
7892 (@pxref{G-Expressions}):
7895 (define (sh-symlink)
7896 (gexp->derivation "sh"
7897 #~(symlink (string-append #$bash "/bin/bash")
7902 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
7903 @c for the funny quote.
7904 Calling the monadic @code{sh-symlink} has no effect. As someone once
7905 said, ``you exit a monad like you exit a building on fire: by running''.
7906 So, to exit the monad and get the desired effect, one must use
7907 @code{run-with-store}:
7910 (run-with-store (open-connection) (sh-symlink))
7911 @result{} /gnu/store/...-sh-symlink
7914 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
7915 new ``meta-commands'' to make it easier to deal with monadic procedures:
7916 @code{run-in-store}, and @code{enter-store-monad}. The former is used
7917 to ``run'' a single monadic value through the store:
7920 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
7921 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7924 The latter enters a recursive REPL, where all the return values are
7925 automatically run through the store:
7928 scheme@@(guile-user)> ,enter-store-monad
7929 store-monad@@(guile-user) [1]> (package->derivation hello)
7930 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7931 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
7932 $3 = "/gnu/store/@dots{}-foo"
7933 store-monad@@(guile-user) [1]> ,q
7934 scheme@@(guile-user)>
7938 Note that non-monadic values cannot be returned in the
7939 @code{store-monad} REPL.
7941 The main syntactic forms to deal with monads in general are provided by
7942 the @code{(guix monads)} module and are described below.
7944 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
7945 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
7949 @deffn {Scheme Syntax} return @var{val}
7950 Return a monadic value that encapsulates @var{val}.
7953 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
7954 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
7955 procedures @var{mproc}@dots{}@footnote{This operation is commonly
7956 referred to as ``bind'', but that name denotes an unrelated procedure in
7957 Guile. Thus we use this somewhat cryptic symbol inherited from the
7958 Haskell language.}. There can be one @var{mproc} or several of them, as
7963 (with-monad %state-monad
7965 (lambda (x) (return (+ 1 x)))
7966 (lambda (x) (return (* 2 x)))))
7970 @result{} some-state
7974 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
7976 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
7978 Bind the variables @var{var} to the monadic values @var{mval} in
7979 @var{body}, which is a sequence of expressions. As with the bind
7980 operator, this can be thought of as ``unpacking'' the raw, non-monadic
7981 value ``contained'' in @var{mval} and making @var{var} refer to that
7982 raw, non-monadic value within the scope of the @var{body}. The form
7983 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
7984 @var{val}, as per @code{let}. The binding operations occur in sequence
7985 from left to right. The last expression of @var{body} must be a monadic
7986 expression, and its result will become the result of the @code{mlet} or
7987 @code{mlet*} when run in the @var{monad}.
7989 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
7990 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
7993 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
7994 Bind @var{mexp} and the following monadic expressions in sequence,
7995 returning the result of the last expression. Every expression in the
7996 sequence must be a monadic expression.
7998 This is akin to @code{mlet}, except that the return values of the
7999 monadic expressions are ignored. In that sense, it is analogous to
8000 @code{begin}, but applied to monadic expressions.
8003 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
8004 When @var{condition} is true, evaluate the sequence of monadic
8005 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
8006 @var{condition} is false, return @code{*unspecified*} in the current
8007 monad. Every expression in the sequence must be a monadic expression.
8010 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
8011 When @var{condition} is false, evaluate the sequence of monadic
8012 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
8013 @var{condition} is true, return @code{*unspecified*} in the current
8014 monad. Every expression in the sequence must be a monadic expression.
8018 The @code{(guix monads)} module provides the @dfn{state monad}, which
8019 allows an additional value---the state---to be @emph{threaded} through
8020 monadic procedure calls.
8022 @defvr {Scheme Variable} %state-monad
8023 The state monad. Procedures in the state monad can access and change
8024 the state that is threaded.
8026 Consider the example below. The @code{square} procedure returns a value
8027 in the state monad. It returns the square of its argument, but also
8028 increments the current state value:
8032 (mlet %state-monad ((count (current-state)))
8033 (mbegin %state-monad
8034 (set-current-state (+ 1 count))
8037 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
8042 When ``run'' through @code{%state-monad}, we obtain that additional state
8043 value, which is the number of @code{square} calls.
8046 @deffn {Monadic Procedure} current-state
8047 Return the current state as a monadic value.
8050 @deffn {Monadic Procedure} set-current-state @var{value}
8051 Set the current state to @var{value} and return the previous state as a
8055 @deffn {Monadic Procedure} state-push @var{value}
8056 Push @var{value} to the current state, which is assumed to be a list,
8057 and return the previous state as a monadic value.
8060 @deffn {Monadic Procedure} state-pop
8061 Pop a value from the current state and return it as a monadic value.
8062 The state is assumed to be a list.
8065 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
8066 Run monadic value @var{mval} starting with @var{state} as the initial
8067 state. Return two values: the resulting value, and the resulting state.
8070 The main interface to the store monad, provided by the @code{(guix
8071 store)} module, is as follows.
8073 @defvr {Scheme Variable} %store-monad
8074 The store monad---an alias for @code{%state-monad}.
8076 Values in the store monad encapsulate accesses to the store. When its
8077 effect is needed, a value of the store monad must be ``evaluated'' by
8078 passing it to the @code{run-with-store} procedure (see below).
8081 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
8082 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
8083 open store connection.
8086 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
8087 Return as a monadic value the absolute file name in the store of the file
8088 containing @var{text}, a string. @var{references} is a list of store items that the
8089 resulting text file refers to; it defaults to the empty list.
8092 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
8093 Return as a monadic value the absolute file name in the store of the file
8094 containing @var{data}, a bytevector. @var{references} is a list of store
8095 items that the resulting binary file refers to; it defaults to the empty list.
8098 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
8099 [#:recursive? #t] [#:select? (const #t)]
8100 Return the name of @var{file} once interned in the store. Use
8101 @var{name} as its store name, or the basename of @var{file} if
8102 @var{name} is omitted.
8104 When @var{recursive?} is true, the contents of @var{file} are added
8105 recursively; if @var{file} designates a flat file and @var{recursive?}
8106 is true, its contents are added, and its permission bits are kept.
8108 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
8109 @var{stat})} for each directory entry, where @var{file} is the entry's
8110 absolute file name and @var{stat} is the result of @code{lstat}; exclude
8111 entries for which @var{select?} does not return true.
8113 The example below adds a file to the store, under two different names:
8116 (run-with-store (open-connection)
8117 (mlet %store-monad ((a (interned-file "README"))
8118 (b (interned-file "README" "LEGU-MIN")))
8119 (return (list a b))))
8121 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
8126 The @code{(guix packages)} module exports the following package-related
8129 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
8130 [#:system (%current-system)] [#:target #f] @
8133 value in the absolute file name of @var{file} within the @var{output}
8134 directory of @var{package}. When @var{file} is omitted, return the name
8135 of the @var{output} directory of @var{package}. When @var{target} is
8136 true, use it as a cross-compilation target triplet.
8138 Note that this procedure does @emph{not} build @var{package}. Thus, the
8139 result might or might not designate an existing file. We recommend not
8140 using this procedure unless you know what you are doing.
8143 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
8144 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
8145 @var{target} [@var{system}]
8146 Monadic version of @code{package-derivation} and
8147 @code{package-cross-derivation} (@pxref{Defining Packages}).
8152 @section G-Expressions
8154 @cindex G-expression
8155 @cindex build code quoting
8156 So we have ``derivations'', which represent a sequence of build actions
8157 to be performed to produce an item in the store (@pxref{Derivations}).
8158 These build actions are performed when asking the daemon to actually
8159 build the derivations; they are run by the daemon in a container
8160 (@pxref{Invoking guix-daemon}).
8162 @cindex strata of code
8163 It should come as no surprise that we like to write these build actions
8164 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
8165 code@footnote{The term @dfn{stratum} in this context was coined by
8166 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
8167 Kiselyov, who has written insightful
8168 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
8169 on this topic}, refers to this kind of code generation as
8170 @dfn{staging}.}: the ``host code''---code that defines packages, talks
8171 to the daemon, etc.---and the ``build code''---code that actually
8172 performs build actions, such as making directories, invoking
8173 @command{make}, etc.
8175 To describe a derivation and its build actions, one typically needs to
8176 embed build code inside host code. It boils down to manipulating build
8177 code as data, and the homoiconicity of Scheme---code has a direct
8178 representation as data---comes in handy for that. But we need more than
8179 the normal @code{quasiquote} mechanism in Scheme to construct build
8182 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
8183 S-expressions adapted to build expressions. G-expressions, or
8184 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
8185 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
8186 @code{#$}, and @code{#$@@}), which are comparable to
8187 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
8188 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
8189 GNU Guile Reference Manual}). However, there are major differences:
8193 Gexps are meant to be written to a file and run or manipulated by other
8197 When a high-level object such as a package or derivation is unquoted
8198 inside a gexp, the result is as if its output file name had been
8202 Gexps carry information about the packages or derivations they refer to,
8203 and these dependencies are automatically added as inputs to the build
8204 processes that use them.
8207 @cindex lowering, of high-level objects in gexps
8208 This mechanism is not limited to package and derivation
8209 objects: @dfn{compilers} able to ``lower'' other high-level objects to
8210 derivations or files in the store can be defined,
8211 such that these objects can also be inserted
8212 into gexps. For example, a useful type of high-level objects that can be
8213 inserted in a gexp is ``file-like objects'', which make it easy to
8214 add files to the store and to refer to them in
8215 derivations and such (see @code{local-file} and @code{plain-file}
8218 To illustrate the idea, here is an example of a gexp:
8225 (symlink (string-append #$coreutils "/bin/ls")
8229 This gexp can be passed to @code{gexp->derivation}; we obtain a
8230 derivation that builds a directory containing exactly one symlink to
8231 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
8234 (gexp->derivation "the-thing" build-exp)
8237 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
8238 substituted to the reference to the @var{coreutils} package in the
8239 actual build code, and @var{coreutils} is automatically made an input to
8240 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
8241 output)}) is replaced by a string containing the directory name of the
8242 output of the derivation.
8244 @cindex cross compilation
8245 In a cross-compilation context, it is useful to distinguish between
8246 references to the @emph{native} build of a package---that can run on the
8247 host---versus references to cross builds of a package. To that end, the
8248 @code{#+} plays the same role as @code{#$}, but is a reference to a
8249 native package build:
8252 (gexp->derivation "vi"
8255 (mkdir (string-append #$output "/bin"))
8256 (system* (string-append #+coreutils "/bin/ln")
8258 (string-append #$emacs "/bin/emacs")
8259 (string-append #$output "/bin/vi")))
8260 #:target "aarch64-linux-gnu")
8264 In the example above, the native build of @var{coreutils} is used, so
8265 that @command{ln} can actually run on the host; but then the
8266 cross-compiled build of @var{emacs} is referenced.
8268 @cindex imported modules, for gexps
8269 @findex with-imported-modules
8270 Another gexp feature is @dfn{imported modules}: sometimes you want to be
8271 able to use certain Guile modules from the ``host environment'' in the
8272 gexp, so those modules should be imported in the ``build environment''.
8273 The @code{with-imported-modules} form allows you to express that:
8276 (let ((build (with-imported-modules '((guix build utils))
8278 (use-modules (guix build utils))
8279 (mkdir-p (string-append #$output "/bin"))))))
8280 (gexp->derivation "empty-dir"
8283 (display "success!\n")
8288 In this example, the @code{(guix build utils)} module is automatically
8289 pulled into the isolated build environment of our gexp, such that
8290 @code{(use-modules (guix build utils))} works as expected.
8292 @cindex module closure
8293 @findex source-module-closure
8294 Usually you want the @emph{closure} of the module to be imported---i.e.,
8295 the module itself and all the modules it depends on---rather than just
8296 the module; failing to do that, attempts to use the module will fail
8297 because of missing dependent modules. The @code{source-module-closure}
8298 procedure computes the closure of a module by looking at its source file
8299 headers, which comes in handy in this case:
8302 (use-modules (guix modules)) ;for 'source-module-closure'
8304 (with-imported-modules (source-module-closure
8305 '((guix build utils)
8307 (gexp->derivation "something-with-vms"
8309 (use-modules (guix build utils)
8314 @cindex extensions, for gexps
8315 @findex with-extensions
8316 In the same vein, sometimes you want to import not just pure-Scheme
8317 modules, but also ``extensions'' such as Guile bindings to C libraries
8318 or other ``full-blown'' packages. Say you need the @code{guile-json}
8319 package available on the build side, here's how you would do it:
8322 (use-modules (gnu packages guile)) ;for 'guile-json'
8324 (with-extensions (list guile-json)
8325 (gexp->derivation "something-with-json"
8327 (use-modules (json))
8331 The syntactic form to construct gexps is summarized below.
8333 @deffn {Scheme Syntax} #~@var{exp}
8334 @deffnx {Scheme Syntax} (gexp @var{exp})
8335 Return a G-expression containing @var{exp}. @var{exp} may contain one
8336 or more of the following forms:
8340 @itemx (ungexp @var{obj})
8341 Introduce a reference to @var{obj}. @var{obj} may have one of the
8342 supported types, for example a package or a
8343 derivation, in which case the @code{ungexp} form is replaced by its
8344 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
8346 If @var{obj} is a list, it is traversed and references to supported
8347 objects are substituted similarly.
8349 If @var{obj} is another gexp, its contents are inserted and its
8350 dependencies are added to those of the containing gexp.
8352 If @var{obj} is another kind of object, it is inserted as is.
8354 @item #$@var{obj}:@var{output}
8355 @itemx (ungexp @var{obj} @var{output})
8356 This is like the form above, but referring explicitly to the
8357 @var{output} of @var{obj}---this is useful when @var{obj} produces
8358 multiple outputs (@pxref{Packages with Multiple Outputs}).
8361 @itemx #+@var{obj}:output
8362 @itemx (ungexp-native @var{obj})
8363 @itemx (ungexp-native @var{obj} @var{output})
8364 Same as @code{ungexp}, but produces a reference to the @emph{native}
8365 build of @var{obj} when used in a cross compilation context.
8367 @item #$output[:@var{output}]
8368 @itemx (ungexp output [@var{output}])
8369 Insert a reference to derivation output @var{output}, or to the main
8370 output when @var{output} is omitted.
8372 This only makes sense for gexps passed to @code{gexp->derivation}.
8375 @itemx (ungexp-splicing @var{lst})
8376 Like the above, but splices the contents of @var{lst} inside the
8380 @itemx (ungexp-native-splicing @var{lst})
8381 Like the above, but refers to native builds of the objects listed in
8386 G-expressions created by @code{gexp} or @code{#~} are run-time objects
8387 of the @code{gexp?} type (see below).
8390 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
8391 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
8392 in their execution environment.
8394 Each item in @var{modules} can be the name of a module, such as
8395 @code{(guix build utils)}, or it can be a module name, followed by an
8396 arrow, followed by a file-like object:
8399 `((guix build utils)
8401 ((guix config) => ,(scheme-file "config.scm"
8402 #~(define-module @dots{}))))
8406 In the example above, the first two modules are taken from the search
8407 path, and the last one is created from the given file-like object.
8409 This form has @emph{lexical} scope: it has an effect on the gexps
8410 directly defined in @var{body}@dots{}, but not on those defined, say, in
8411 procedures called from @var{body}@dots{}.
8414 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
8415 Mark the gexps defined in @var{body}@dots{} as requiring
8416 @var{extensions} in their build and execution environment.
8417 @var{extensions} is typically a list of package objects such as those
8418 defined in the @code{(gnu packages guile)} module.
8420 Concretely, the packages listed in @var{extensions} are added to the
8421 load path while compiling imported modules in @var{body}@dots{}; they
8422 are also added to the load path of the gexp returned by
8426 @deffn {Scheme Procedure} gexp? @var{obj}
8427 Return @code{#t} if @var{obj} is a G-expression.
8430 G-expressions are meant to be written to disk, either as code building
8431 some derivation, or as plain files in the store. The monadic procedures
8432 below allow you to do that (@pxref{The Store Monad}, for more
8433 information about monads).
8435 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
8436 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
8437 [#:hash #f] [#:hash-algo #f] @
8438 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
8439 [#:module-path @code{%load-path}] @
8440 [#:effective-version "2.2"] @
8441 [#:references-graphs #f] [#:allowed-references #f] @
8442 [#:disallowed-references #f] @
8443 [#:leaked-env-vars #f] @
8444 [#:script-name (string-append @var{name} "-builder")] @
8445 [#:deprecation-warnings #f] @
8446 [#:local-build? #f] [#:substitutable? #t] @
8447 [#:properties '()] [#:guile-for-build #f]
8448 Return a derivation @var{name} that runs @var{exp} (a gexp) with
8449 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
8450 stored in a file called @var{script-name}. When @var{target} is true,
8451 it is used as the cross-compilation target triplet for packages referred
8454 @var{modules} is deprecated in favor of @code{with-imported-modules}.
8456 make @var{modules} available in the evaluation context of @var{exp};
8457 @var{modules} is a list of names of Guile modules searched in
8458 @var{module-path} to be copied in the store, compiled, and made available in
8459 the load path during the execution of @var{exp}---e.g., @code{((guix
8460 build utils) (guix build gnu-build-system))}.
8462 @var{effective-version} determines the string to use when adding extensions of
8463 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
8465 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
8468 When @var{references-graphs} is true, it must be a list of tuples of one of the
8472 (@var{file-name} @var{package})
8473 (@var{file-name} @var{package} @var{output})
8474 (@var{file-name} @var{derivation})
8475 (@var{file-name} @var{derivation} @var{output})
8476 (@var{file-name} @var{store-item})
8479 The right-hand-side of each element of @var{references-graphs} is automatically made
8480 an input of the build process of @var{exp}. In the build environment, each
8481 @var{file-name} contains the reference graph of the corresponding item, in a simple
8484 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
8485 In the latter case, the list denotes store items that the result is allowed to
8486 refer to. Any reference to another store item will lead to a build error.
8487 Similarly for @var{disallowed-references}, which can list items that must not be
8488 referenced by the outputs.
8490 @var{deprecation-warnings} determines whether to show deprecation warnings while
8491 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
8493 The other arguments are as for @code{derivation} (@pxref{Derivations}).
8496 @cindex file-like objects
8497 The @code{local-file}, @code{plain-file}, @code{computed-file},
8498 @code{program-file}, and @code{scheme-file} procedures below return
8499 @dfn{file-like objects}. That is, when unquoted in a G-expression,
8500 these objects lead to a file in the store. Consider this G-expression:
8503 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
8504 #$(local-file "/tmp/my-nscd.conf"))
8507 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
8508 to the store. Once expanded, for instance @i{via}
8509 @code{gexp->derivation}, the G-expression refers to that copy under
8510 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
8511 does not have any effect on what the G-expression does.
8512 @code{plain-file} can be used similarly; it differs in that the file
8513 content is directly passed as a string.
8515 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
8516 [#:recursive? #f] [#:select? (const #t)]
8517 Return an object representing local file @var{file} to add to the store;
8518 this object can be used in a gexp. If @var{file} is a literal string
8519 denoting a relative file name, it is looked up relative to the source
8520 file where it appears; if @var{file} is not a literal string, it is
8521 looked up relative to the current working directory at run time.
8522 @var{file} will be added to the store under @var{name}--by default the
8523 base name of @var{file}.
8525 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
8526 designates a flat file and @var{recursive?} is true, its contents are added, and its
8527 permission bits are kept.
8529 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
8530 @var{stat})} for each directory entry, where @var{file} is the entry's
8531 absolute file name and @var{stat} is the result of @code{lstat}; exclude
8532 entries for which @var{select?} does not return true.
8534 This is the declarative counterpart of the @code{interned-file} monadic
8535 procedure (@pxref{The Store Monad, @code{interned-file}}).
8538 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
8539 Return an object representing a text file called @var{name} with the given
8540 @var{content} (a string or a bytevector) to be added to the store.
8542 This is the declarative counterpart of @code{text-file}.
8545 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
8548 Return an object representing the store item @var{name}, a file or
8549 directory computed by @var{gexp}. When @var{local-build?} is true (the
8550 default), the derivation is built locally. @var{options} is a list of
8551 additional arguments to pass to @code{gexp->derivation}.
8553 This is the declarative counterpart of @code{gexp->derivation}.
8556 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
8557 [#:guile (default-guile)] [#:module-path %load-path] @
8558 [#:system (%current-system)] [#:target #f]
8559 Return an executable script @var{name} that runs @var{exp} using
8560 @var{guile}, with @var{exp}'s imported modules in its search path.
8561 Look up @var{exp}'s modules in @var{module-path}.
8563 The example below builds a script that simply invokes the @command{ls}
8567 (use-modules (guix gexp) (gnu packages base))
8569 (gexp->script "list-files"
8570 #~(execl #$(file-append coreutils "/bin/ls")
8574 When ``running'' it through the store (@pxref{The Store Monad,
8575 @code{run-with-store}}), we obtain a derivation that produces an
8576 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
8579 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
8581 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
8585 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
8586 [#:guile #f] [#:module-path %load-path]
8587 Return an object representing the executable store item @var{name} that
8588 runs @var{gexp}. @var{guile} is the Guile package used to execute that
8589 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
8591 This is the declarative counterpart of @code{gexp->script}.
8594 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
8595 [#:set-load-path? #t] [#:module-path %load-path] @
8597 [#:guile (default-guile)]
8598 Return a derivation that builds a file @var{name} containing @var{exp}.
8599 When @var{splice?} is true, @var{exp} is considered to be a list of
8600 expressions that will be spliced in the resulting file.
8602 When @var{set-load-path?} is true, emit code in the resulting file to
8603 set @code{%load-path} and @code{%load-compiled-path} to honor
8604 @var{exp}'s imported modules. Look up @var{exp}'s modules in
8607 The resulting file holds references to all the dependencies of @var{exp}
8608 or a subset thereof.
8611 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} @
8612 [#:splice? #f] [#:set-load-path? #t]
8613 Return an object representing the Scheme file @var{name} that contains
8616 This is the declarative counterpart of @code{gexp->file}.
8619 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
8620 Return as a monadic value a derivation that builds a text file
8621 containing all of @var{text}. @var{text} may list, in addition to
8622 strings, objects of any type that can be used in a gexp: packages,
8623 derivations, local file objects, etc. The resulting store file holds
8624 references to all these.
8626 This variant should be preferred over @code{text-file} anytime the file
8627 to create will reference items from the store. This is typically the
8628 case when building a configuration file that embeds store file names,
8632 (define (profile.sh)
8633 ;; Return the name of a shell script in the store that
8634 ;; initializes the 'PATH' environment variable.
8635 (text-file* "profile.sh"
8636 "export PATH=" coreutils "/bin:"
8637 grep "/bin:" sed "/bin\n"))
8640 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
8641 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
8642 preventing them from being garbage-collected during its lifetime.
8645 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
8646 Return an object representing store file @var{name} containing
8647 @var{text}. @var{text} is a sequence of strings and file-like objects,
8651 (mixed-text-file "profile"
8652 "export PATH=" coreutils "/bin:" grep "/bin")
8655 This is the declarative counterpart of @code{text-file*}.
8658 @deffn {Scheme Procedure} file-union @var{name} @var{files}
8659 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
8660 Each item in @var{files} must be a two-element list where the first element is the
8661 file name to use in the new directory, and the second element is a gexp
8662 denoting the target file. Here's an example:
8666 `(("hosts" ,(plain-file "hosts"
8667 "127.0.0.1 localhost"))
8668 ("bashrc" ,(plain-file "bashrc"
8669 "alias ls='ls --color=auto'"))))
8672 This yields an @code{etc} directory containing these two files.
8675 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
8676 Return a directory that is the union of @var{things}, where @var{things} is a list of
8677 file-like objects denoting directories. For example:
8680 (directory-union "guile+emacs" (list guile emacs))
8683 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
8686 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
8687 Return a file-like object that expands to the concatenation of @var{obj}
8688 and @var{suffix}, where @var{obj} is a lowerable object and each
8689 @var{suffix} is a string.
8691 As an example, consider this gexp:
8694 (gexp->script "run-uname"
8695 #~(system* #$(file-append coreutils
8699 The same effect could be achieved with:
8702 (gexp->script "run-uname"
8703 #~(system* (string-append #$coreutils
8707 There is one difference though: in the @code{file-append} case, the
8708 resulting script contains the absolute file name as a string, whereas in
8709 the second case, the resulting script contains a @code{(string-append
8710 @dots{})} expression to construct the file name @emph{at run time}.
8713 @deffn {Scheme Syntax} let-system @var{system} @var{body}@dots{}
8714 @deffnx {Scheme Syntax} let-system (@var{system} @var{target}) @var{body}@dots{}
8715 Bind @var{system} to the currently targeted system---e.g.,
8716 @code{"x86_64-linux"}---within @var{body}.
8718 In the second case, additionally bind @var{target} to the current
8719 cross-compilation target---a GNU triplet such as
8720 @code{"arm-linux-gnueabihf"}---or @code{#f} if we are not
8723 @code{let-system} is useful in the occasional case where the object
8724 spliced into the gexp depends on the target system, as in this example:
8728 #+(let-system system
8729 (cond ((string-prefix? "armhf-" system)
8730 (file-append qemu "/bin/qemu-system-arm"))
8731 ((string-prefix? "x86_64-" system)
8732 (file-append qemu "/bin/qemu-system-x86_64"))
8735 "-net" "user" #$image)
8739 @deffn {Scheme Syntax} with-parameters ((@var{parameter} @var{value}) @dots{}) @var{exp}
8740 This macro is similar to the @code{parameterize} form for
8741 dynamically-bound @dfn{parameters} (@pxref{Parameters,,, guile, GNU
8742 Guile Reference Manual}). The key difference is that it takes effect
8743 when the file-like object returned by @var{exp} is lowered to a
8744 derivation or store item.
8746 A typical use of @code{with-parameters} is to force the system in effect
8750 (with-parameters ((%current-system "i686-linux"))
8754 The example above returns an object that corresponds to the i686 build
8755 of Coreutils, regardless of the current value of @code{%current-system}.
8759 Of course, in addition to gexps embedded in ``host'' code, there are
8760 also modules containing build tools. To make it clear that they are
8761 meant to be used in the build stratum, these modules are kept in the
8762 @code{(guix build @dots{})} name space.
8764 @cindex lowering, of high-level objects in gexps
8765 Internally, high-level objects are @dfn{lowered}, using their compiler,
8766 to either derivations or store items. For instance, lowering a package
8767 yields a derivation, and lowering a @code{plain-file} yields a store
8768 item. This is achieved using the @code{lower-object} monadic procedure.
8770 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
8772 Return as a value in @code{%store-monad} the derivation or store item
8773 corresponding to @var{obj} for @var{system}, cross-compiling for
8774 @var{target} if @var{target} is true. @var{obj} must be an object that
8775 has an associated gexp compiler, such as a @code{<package>}.
8778 @node Invoking guix repl
8779 @section Invoking @command{guix repl}
8781 @cindex REPL, read-eval-print loop, script
8782 The @command{guix repl} command makes it easier to program Guix in Guile
8783 by launching a Guile @dfn{read-eval-print loop} (REPL) for interactive
8784 programming (@pxref{Using Guile Interactively,,, guile,
8785 GNU Guile Reference Manual}), or by running Guile scripts
8786 (@pxref{Running Guile Scripts,,, guile,
8787 GNU Guile Reference Manual}).
8788 Compared to just launching the @command{guile}
8789 command, @command{guix repl} guarantees that all the Guix modules and all its
8790 dependencies are available in the search path.
8792 The general syntax is:
8795 guix repl @var{options} [@var{file} @var{args}]
8798 When a @var{file} argument is provided, @var{file} is
8799 executed as a Guile scripts:
8802 guix repl my-script.scm
8805 To pass arguments to the script, use @code{--} to prevent them from
8806 being interpreted as arguments to @command{guix repl} itself:
8809 guix repl -- my-script.scm --input=foo.txt
8812 To make a script executable directly from the shell, using the guix
8813 executable that is on the user's search path, add the following two
8814 lines at the top of the script:
8817 @code{#!/usr/bin/env -S guix repl --}
8821 Without a file name argument, a Guile REPL is started:
8825 scheme@@(guile-user)> ,use (gnu packages base)
8826 scheme@@(guile-user)> coreutils
8827 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
8831 In addition, @command{guix repl} implements a simple machine-readable REPL
8832 protocol for use by @code{(guix inferior)}, a facility to interact with
8833 @dfn{inferiors}, separate processes running a potentially different revision
8836 The available options are as follows:
8839 @item --type=@var{type}
8840 @itemx -t @var{type}
8841 Start a REPL of the given @var{TYPE}, which can be one of the following:
8845 This is default, and it spawns a standard full-featured Guile REPL.
8847 Spawn a REPL that uses the machine-readable protocol. This is the protocol
8848 that the @code{(guix inferior)} module speaks.
8851 @item --listen=@var{endpoint}
8852 By default, @command{guix repl} reads from standard input and writes to
8853 standard output. When this option is passed, it will instead listen for
8854 connections on @var{endpoint}. Here are examples of valid options:
8857 @item --listen=tcp:37146
8858 Accept connections on localhost on port 37146.
8860 @item --listen=unix:/tmp/socket
8861 Accept connections on the Unix-domain socket @file{/tmp/socket}.
8864 @item --load-path=@var{directory}
8865 @itemx -L @var{directory}
8866 Add @var{directory} to the front of the package module search path
8867 (@pxref{Package Modules}).
8869 This allows users to define their own packages and make them visible to
8873 Inhibit loading of the @file{~/.guile} file. By default, that
8874 configuration file is loaded when spawning a @code{guile} REPL.
8877 @c *********************************************************************
8881 This section describes Guix command-line utilities. Some of them are
8882 primarily targeted at developers and users who write new package
8883 definitions, while others are more generally useful. They complement
8884 the Scheme programming interface of Guix in a convenient way.
8887 * Invoking guix build:: Building packages from the command line.
8888 * Invoking guix edit:: Editing package definitions.
8889 * Invoking guix download:: Downloading a file and printing its hash.
8890 * Invoking guix hash:: Computing the cryptographic hash of a file.
8891 * Invoking guix import:: Importing package definitions.
8892 * Invoking guix refresh:: Updating package definitions.
8893 * Invoking guix lint:: Finding errors in package definitions.
8894 * Invoking guix size:: Profiling disk usage.
8895 * Invoking guix graph:: Visualizing the graph of packages.
8896 * Invoking guix publish:: Sharing substitutes.
8897 * Invoking guix challenge:: Challenging substitute servers.
8898 * Invoking guix copy:: Copying to and from a remote store.
8899 * Invoking guix container:: Process isolation.
8900 * Invoking guix weather:: Assessing substitute availability.
8901 * Invoking guix processes:: Listing client processes.
8904 @node Invoking guix build
8905 @section Invoking @command{guix build}
8907 @cindex package building
8908 @cindex @command{guix build}
8909 The @command{guix build} command builds packages or derivations and
8910 their dependencies, and prints the resulting store paths. Note that it
8911 does not modify the user's profile---this is the job of the
8912 @command{guix package} command (@pxref{Invoking guix package}). Thus,
8913 it is mainly useful for distribution developers.
8915 The general syntax is:
8918 guix build @var{options} @var{package-or-derivation}@dots{}
8921 As an example, the following command builds the latest versions of Emacs
8922 and of Guile, displays their build logs, and finally displays the
8923 resulting directories:
8926 guix build emacs guile
8929 Similarly, the following command builds all the available packages:
8932 guix build --quiet --keep-going \
8933 `guix package -A | cut -f1,2 --output-delimiter=@@`
8936 @var{package-or-derivation} may be either the name of a package found in
8937 the software distribution such as @code{coreutils} or
8938 @code{coreutils@@8.20}, or a derivation such as
8939 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
8940 package with the corresponding name (and optionally version) is searched
8941 for among the GNU distribution modules (@pxref{Package Modules}).
8943 Alternatively, the @option{--expression} option may be used to specify a
8944 Scheme expression that evaluates to a package; this is useful when
8945 disambiguating among several same-named packages or package variants is
8948 There may be zero or more @var{options}. The available options are
8949 described in the subsections below.
8952 * Common Build Options:: Build options for most commands.
8953 * Package Transformation Options:: Creating variants of packages.
8954 * Additional Build Options:: Options specific to 'guix build'.
8955 * Debugging Build Failures:: Real life packaging experience.
8958 @node Common Build Options
8959 @subsection Common Build Options
8961 A number of options that control the build process are common to
8962 @command{guix build} and other commands that can spawn builds, such as
8963 @command{guix package} or @command{guix archive}. These are the
8968 @item --load-path=@var{directory}
8969 @itemx -L @var{directory}
8970 Add @var{directory} to the front of the package module search path
8971 (@pxref{Package Modules}).
8973 This allows users to define their own packages and make them visible to
8974 the command-line tools.
8978 Keep the build tree of failed builds. Thus, if a build fails, its build
8979 tree is kept under @file{/tmp}, in a directory whose name is shown at
8980 the end of the build log. This is useful when debugging build issues.
8981 @xref{Debugging Build Failures}, for tips and tricks on how to debug
8984 This option implies @option{--no-offload}, and it has no effect when
8985 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
8986 Store, the @env{GUIX_DAEMON_SOCKET} variable}).
8990 Keep going when some of the derivations fail to build; return only once
8991 all the builds have either completed or failed.
8993 The default behavior is to stop as soon as one of the specified
8994 derivations has failed.
8998 Do not build the derivations.
9000 @anchor{fallback-option}
9002 When substituting a pre-built binary fails, fall back to building
9003 packages locally (@pxref{Substitution Failure}).
9005 @item --substitute-urls=@var{urls}
9006 @anchor{client-substitute-urls}
9007 Consider @var{urls} the whitespace-separated list of substitute source
9008 URLs, overriding the default list of URLs of @command{guix-daemon}
9009 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
9011 This means that substitutes may be downloaded from @var{urls}, provided
9012 they are signed by a key authorized by the system administrator
9013 (@pxref{Substitutes}).
9015 When @var{urls} is the empty string, substitutes are effectively
9018 @item --no-substitutes
9019 Do not use substitutes for build products. That is, always build things
9020 locally instead of allowing downloads of pre-built binaries
9021 (@pxref{Substitutes}).
9024 Do not ``graft'' packages. In practice, this means that package updates
9025 available as grafts are not applied. @xref{Security Updates}, for more
9026 information on grafts.
9028 @item --rounds=@var{n}
9029 Build each derivation @var{n} times in a row, and raise an error if
9030 consecutive build results are not bit-for-bit identical.
9032 This is a useful way to detect non-deterministic builds processes.
9033 Non-deterministic build processes are a problem because they make it
9034 practically impossible for users to @emph{verify} whether third-party
9035 binaries are genuine. @xref{Invoking guix challenge}, for more.
9037 Note that, currently, the differing build results are not kept around,
9038 so you will have to manually investigate in case of an error---e.g., by
9039 stashing one of the build results with @code{guix archive --export}
9040 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
9044 Do not use offload builds to other machines (@pxref{Daemon Offload
9045 Setup}). That is, always build things locally instead of offloading
9046 builds to remote machines.
9048 @item --max-silent-time=@var{seconds}
9049 When the build or substitution process remains silent for more than
9050 @var{seconds}, terminate it and report a build failure.
9052 By default, the daemon's setting is honored (@pxref{Invoking
9053 guix-daemon, @option{--max-silent-time}}).
9055 @item --timeout=@var{seconds}
9056 Likewise, when the build or substitution process lasts for more than
9057 @var{seconds}, terminate it and report a build failure.
9059 By default, the daemon's setting is honored (@pxref{Invoking
9060 guix-daemon, @option{--timeout}}).
9062 @c Note: This option is actually not part of %standard-build-options but
9063 @c most programs honor it.
9064 @cindex verbosity, of the command-line tools
9065 @cindex build logs, verbosity
9066 @item -v @var{level}
9067 @itemx --verbosity=@var{level}
9068 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
9069 output is produced, 1 is for quiet output, and 2 shows all the build log
9070 output on standard error.
9072 @item --cores=@var{n}
9074 Allow the use of up to @var{n} CPU cores for the build. The special
9075 value @code{0} means to use as many CPU cores as available.
9077 @item --max-jobs=@var{n}
9079 Allow at most @var{n} build jobs in parallel. @xref{Invoking
9080 guix-daemon, @option{--max-jobs}}, for details about this option and the
9081 equivalent @command{guix-daemon} option.
9083 @item --debug=@var{level}
9084 Produce debugging output coming from the build daemon. @var{level} must be an
9085 integer between 0 and 5; higher means more verbose output. Setting a level of
9086 4 or more may be helpful when debugging setup issues with the build daemon.
9090 Behind the scenes, @command{guix build} is essentially an interface to
9091 the @code{package-derivation} procedure of the @code{(guix packages)}
9092 module, and to the @code{build-derivations} procedure of the @code{(guix
9093 derivations)} module.
9095 In addition to options explicitly passed on the command line,
9096 @command{guix build} and other @command{guix} commands that support
9097 building honor the @env{GUIX_BUILD_OPTIONS} environment variable.
9099 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
9100 Users can define this variable to a list of command line options that
9101 will automatically be used by @command{guix build} and other
9102 @command{guix} commands that can perform builds, as in the example
9106 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
9109 These options are parsed independently, and the result is appended to
9110 the parsed command-line options.
9114 @node Package Transformation Options
9115 @subsection Package Transformation Options
9117 @cindex package variants
9118 Another set of command-line options supported by @command{guix build}
9119 and also @command{guix package} are @dfn{package transformation
9120 options}. These are options that make it possible to define @dfn{package
9121 variants}---for instance, packages built from different source code.
9122 This is a convenient way to create customized packages on the fly
9123 without having to type in the definitions of package variants
9124 (@pxref{Defining Packages}).
9128 @item --with-source=@var{source}
9129 @itemx --with-source=@var{package}=@var{source}
9130 @itemx --with-source=@var{package}@@@var{version}=@var{source}
9131 Use @var{source} as the source of @var{package}, and @var{version} as
9133 @var{source} must be a file name or a URL, as for @command{guix
9134 download} (@pxref{Invoking guix download}).
9136 When @var{package} is omitted,
9137 it is taken to be the package name specified on the
9138 command line that matches the base of @var{source}---e.g.,
9139 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
9140 package is @code{guile}.
9142 Likewise, when @var{version} is omitted, the version string is inferred from
9143 @var{source}; in the previous example, it is @code{2.0.10}.
9145 This option allows users to try out versions of packages other than the
9146 one provided by the distribution. The example below downloads
9147 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
9148 the @code{ed} package:
9151 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
9154 As a developer, @option{--with-source} makes it easy to test release
9158 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
9161 @dots{} or to build from a checkout in a pristine environment:
9164 $ git clone git://git.sv.gnu.org/guix.git
9165 $ guix build guix --with-source=guix@@1.0=./guix
9168 @item --with-input=@var{package}=@var{replacement}
9169 Replace dependency on @var{package} by a dependency on
9170 @var{replacement}. @var{package} must be a package name, and
9171 @var{replacement} must be a package specification such as @code{guile}
9172 or @code{guile@@1.8}.
9174 For instance, the following command builds Guix, but replaces its
9175 dependency on the current stable version of Guile with a dependency on
9176 the legacy version of Guile, @code{guile@@2.0}:
9179 guix build --with-input=guile=guile@@2.0 guix
9182 This is a recursive, deep replacement. So in this example, both
9183 @code{guix} and its dependency @code{guile-json} (which also depends on
9184 @code{guile}) get rebuilt against @code{guile@@2.0}.
9186 This is implemented using the @code{package-input-rewriting} Scheme
9187 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
9189 @item --with-graft=@var{package}=@var{replacement}
9190 This is similar to @option{--with-input} but with an important difference:
9191 instead of rebuilding the whole dependency chain, @var{replacement} is
9192 built and then @dfn{grafted} onto the binaries that were initially
9193 referring to @var{package}. @xref{Security Updates}, for more
9194 information on grafts.
9196 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
9197 and all its dependencies, replacing references to the version of GnuTLS
9198 they currently refer to:
9201 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
9204 This has the advantage of being much faster than rebuilding everything.
9205 But there is a caveat: it works if and only if @var{package} and
9206 @var{replacement} are strictly compatible---for example, if they provide
9207 a library, the application binary interface (ABI) of those libraries
9208 must be compatible. If @var{replacement} is somehow incompatible with
9209 @var{package}, then the resulting package may be unusable. Use with
9212 @item --with-git-url=@var{package}=@var{url}
9213 @cindex Git, using the latest commit
9214 @cindex latest commit, building
9215 Build @var{package} from the latest commit of the @code{master} branch of the
9216 Git repository at @var{url}. Git sub-modules of the repository are fetched,
9219 For example, the following command builds the NumPy Python library against the
9220 latest commit of the master branch of Python itself:
9223 guix build python-numpy \
9224 --with-git-url=python=https://github.com/python/cpython
9227 This option can also be combined with @option{--with-branch} or
9228 @option{--with-commit} (see below).
9230 @cindex continuous integration
9231 Obviously, since it uses the latest commit of the given branch, the result of
9232 such a command varies over time. Nevertheless it is a convenient way to
9233 rebuild entire software stacks against the latest commit of one or more
9234 packages. This is particularly useful in the context of continuous
9237 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
9238 consecutive accesses to the same repository. You may want to clean it up once
9239 in a while to save disk space.
9241 @item --with-branch=@var{package}=@var{branch}
9242 Build @var{package} from the latest commit of @var{branch}. If the
9243 @code{source} field of @var{package} is an origin with the @code{git-fetch}
9244 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
9245 repository URL is taken from that @code{source}. Otherwise you have to use
9246 @option{--with-git-url} to specify the URL of the Git repository.
9248 For instance, the following command builds @code{guile-sqlite3} from the
9249 latest commit of its @code{master} branch, and then builds @code{guix} (which
9250 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
9251 specific @code{guile-sqlite3} build:
9254 guix build --with-branch=guile-sqlite3=master cuirass
9257 @item --with-commit=@var{package}=@var{commit}
9258 This is similar to @option{--with-branch}, except that it builds from
9259 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
9260 Git commit SHA1 identifier or a tag.
9263 @node Additional Build Options
9264 @subsection Additional Build Options
9266 The command-line options presented below are specific to @command{guix
9273 Build quietly, without displaying the build log; this is equivalent to
9274 @option{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
9275 (or similar) and can always be retrieved using the @option{--log-file} option.
9277 @item --file=@var{file}
9278 @itemx -f @var{file}
9279 Build the package, derivation, or other file-like object that the code within
9280 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
9282 As an example, @var{file} might contain a package definition like this
9283 (@pxref{Defining Packages}):
9286 @include package-hello.scm
9289 The @var{file} may also contain a JSON representation of one or more
9290 package definitions. Running @code{guix build -f} on @file{hello.json}
9291 with the following contents would result in building the packages
9292 @code{myhello} and @code{greeter}:
9295 @verbatiminclude package-hello.json
9298 @item --manifest=@var{manifest}
9299 @itemx -m @var{manifest}
9300 Build all packages listed in the given @var{manifest}
9301 (@pxref{profile-manifest, @option{--manifest}}).
9303 @item --expression=@var{expr}
9304 @itemx -e @var{expr}
9305 Build the package or derivation @var{expr} evaluates to.
9307 For example, @var{expr} may be @code{(@@ (gnu packages guile)
9308 guile-1.8)}, which unambiguously designates this specific variant of
9309 version 1.8 of Guile.
9311 Alternatively, @var{expr} may be a G-expression, in which case it is used
9312 as a build program passed to @code{gexp->derivation}
9313 (@pxref{G-Expressions}).
9315 Lastly, @var{expr} may refer to a zero-argument monadic procedure
9316 (@pxref{The Store Monad}). The procedure must return a derivation as a
9317 monadic value, which is then passed through @code{run-with-store}.
9321 Build the source derivations of the packages, rather than the packages
9324 For instance, @code{guix build -S gcc} returns something like
9325 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
9328 The returned source tarball is the result of applying any patches and
9329 code snippets specified in the package @code{origin} (@pxref{Defining
9332 Note that @command{guix build -S} compiles the sources only of the
9333 specified packages. They do not include the sources of statically
9334 linked dependencies and by themselves are insufficient for reproducing
9338 Fetch and return the source of @var{package-or-derivation} and all their
9339 dependencies, recursively. This is a handy way to obtain a local copy
9340 of all the source code needed to build @var{packages}, allowing you to
9341 eventually build them even without network access. It is an extension
9342 of the @option{--source} option and can accept one of the following
9343 optional argument values:
9347 This value causes the @option{--sources} option to behave in the same way
9348 as the @option{--source} option.
9351 Build the source derivations of all packages, including any source that
9352 might be listed as @code{inputs}. This is the default value.
9355 $ guix build --sources tzdata
9356 The following derivations will be built:
9357 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
9358 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
9362 Build the source derivations of all packages, as well of all transitive
9363 inputs to the packages. This can be used e.g.@: to
9364 prefetch package source for later offline building.
9367 $ guix build --sources=transitive tzdata
9368 The following derivations will be built:
9369 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
9370 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
9371 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
9372 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
9373 /gnu/store/@dots{}-make-4.1.tar.xz.drv
9374 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
9380 @item --system=@var{system}
9381 @itemx -s @var{system}
9382 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
9383 the system type of the build host. The @command{guix build} command allows
9384 you to repeat this option several times, in which case it builds for all the
9385 specified systems; other commands ignore extraneous @option{-s} options.
9388 The @option{--system} flag is for @emph{native} compilation and must not
9389 be confused with cross-compilation. See @option{--target} below for
9390 information on cross-compilation.
9393 An example use of this is on Linux-based systems, which can emulate
9394 different personalities. For instance, passing
9395 @option{--system=i686-linux} on an @code{x86_64-linux} system or
9396 @option{--system=armhf-linux} on an @code{aarch64-linux} system allows
9397 you to build packages in a complete 32-bit environment.
9400 Building for an @code{armhf-linux} system is unconditionally enabled on
9401 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
9402 allow for this functionality, notably the ThunderX.
9405 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
9406 is enabled (@pxref{Virtualization Services,
9407 @code{qemu-binfmt-service-type}}), you can build for any system for
9408 which a QEMU @code{binfmt_misc} handler is installed.
9410 Builds for a system other than that of the machine you are using can
9411 also be offloaded to a remote machine of the right architecture.
9412 @xref{Daemon Offload Setup}, for more information on offloading.
9414 @item --target=@var{triplet}
9415 @cindex cross-compilation
9416 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
9417 as @code{"aarch64-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
9418 configuration triplets,, autoconf, Autoconf}).
9420 @anchor{build-check}
9422 @cindex determinism, checking
9423 @cindex reproducibility, checking
9424 Rebuild @var{package-or-derivation}, which are already available in the
9425 store, and raise an error if the build results are not bit-for-bit
9428 This mechanism allows you to check whether previously installed
9429 substitutes are genuine (@pxref{Substitutes}), or whether the build result
9430 of a package is deterministic. @xref{Invoking guix challenge}, for more
9431 background information and tools.
9433 When used in conjunction with @option{--keep-failed}, the differing
9434 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
9435 This makes it easy to look for differences between the two results.
9438 @cindex repairing store items
9439 @cindex corruption, recovering from
9440 Attempt to repair the specified store items, if they are corrupt, by
9441 re-downloading or rebuilding them.
9443 This operation is not atomic and thus restricted to @code{root}.
9447 Return the derivation paths, not the output paths, of the given
9450 @item --root=@var{file}
9451 @itemx -r @var{file}
9452 @cindex GC roots, adding
9453 @cindex garbage collector roots, adding
9454 Make @var{file} a symlink to the result, and register it as a garbage
9457 Consequently, the results of this @command{guix build} invocation are
9458 protected from garbage collection until @var{file} is removed. When
9459 that option is omitted, build results are eligible for garbage
9460 collection as soon as the build completes. @xref{Invoking guix gc}, for
9464 @cindex build logs, access
9465 Return the build log file names or URLs for the given
9466 @var{package-or-derivation}, or raise an error if build logs are
9469 This works regardless of how packages or derivations are specified. For
9470 instance, the following invocations are equivalent:
9473 guix build --log-file `guix build -d guile`
9474 guix build --log-file `guix build guile`
9475 guix build --log-file guile
9476 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
9479 If a log is unavailable locally, and unless @option{--no-substitutes} is
9480 passed, the command looks for a corresponding log on one of the
9481 substitute servers (as specified with @option{--substitute-urls}).
9483 So for instance, imagine you want to see the build log of GDB on MIPS,
9484 but you are actually on an @code{x86_64} machine:
9487 $ guix build --log-file gdb -s aarch64-linux
9488 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
9491 You can freely access a huge library of build logs!
9494 @node Debugging Build Failures
9495 @subsection Debugging Build Failures
9497 @cindex build failures, debugging
9498 When defining a new package (@pxref{Defining Packages}), you will
9499 probably find yourself spending some time debugging and tweaking the
9500 build until it succeeds. To do that, you need to operate the build
9501 commands yourself in an environment as close as possible to the one the
9504 To that end, the first thing to do is to use the @option{--keep-failed}
9505 or @option{-K} option of @command{guix build}, which will keep the
9506 failed build tree in @file{/tmp} or whatever directory you specified as
9507 @env{TMPDIR} (@pxref{Invoking guix build, @option{--keep-failed}}).
9509 From there on, you can @command{cd} to the failed build tree and source
9510 the @file{environment-variables} file, which contains all the
9511 environment variable definitions that were in place when the build
9512 failed. So let's say you're debugging a build failure in package
9513 @code{foo}; a typical session would look like this:
9517 @dots{} @i{build fails}
9518 $ cd /tmp/guix-build-foo.drv-0
9519 $ source ./environment-variables
9523 Now, you can invoke commands as if you were the daemon (almost) and
9524 troubleshoot your build process.
9526 Sometimes it happens that, for example, a package's tests pass when you
9527 run them manually but they fail when the daemon runs them. This can
9528 happen because the daemon runs builds in containers where, unlike in our
9529 environment above, network access is missing, @file{/bin/sh} does not
9530 exist, etc. (@pxref{Build Environment Setup}).
9532 In such cases, you may need to run inspect the build process from within
9533 a container similar to the one the build daemon creates:
9538 $ cd /tmp/guix-build-foo.drv-0
9539 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
9540 [env]# source ./environment-variables
9544 Here, @command{guix environment -C} creates a container and spawns a new
9545 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
9546 strace gdb} part adds the @command{strace} and @command{gdb} commands to
9547 the container, which you may find handy while debugging. The
9548 @option{--no-grafts} option makes sure we get the exact same
9549 environment, with ungrafted packages (@pxref{Security Updates}, for more
9552 To get closer to a container like that used by the build daemon, we can
9553 remove @file{/bin/sh}:
9559 (Don't worry, this is harmless: this is all happening in the throw-away
9560 container created by @command{guix environment}.)
9562 The @command{strace} command is probably not in the search path, but we
9566 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
9569 In this way, not only you will have reproduced the environment variables
9570 the daemon uses, you will also be running the build process in a container
9571 similar to the one the daemon uses.
9574 @node Invoking guix edit
9575 @section Invoking @command{guix edit}
9577 @cindex @command{guix edit}
9578 @cindex package definition, editing
9579 So many packages, so many source files! The @command{guix edit} command
9580 facilitates the life of users and packagers by pointing their editor at
9581 the source file containing the definition of the specified packages.
9585 guix edit gcc@@4.9 vim
9589 launches the program specified in the @env{VISUAL} or in the
9590 @env{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
9593 If you are using a Guix Git checkout (@pxref{Building from Git}), or
9594 have created your own packages on @env{GUIX_PACKAGE_PATH}
9595 (@pxref{Package Modules}), you will be able to edit the package
9596 recipes. In other cases, you will be able to examine the read-only recipes
9597 for packages currently in the store.
9599 Instead of @env{GUIX_PACKAGE_PATH}, the command-line option
9600 @option{--load-path=@var{directory}} (or in short @option{-L
9601 @var{directory}}) allows you to add @var{directory} to the front of the
9602 package module search path and so make your own packages visible.
9604 @node Invoking guix download
9605 @section Invoking @command{guix download}
9607 @cindex @command{guix download}
9608 @cindex downloading package sources
9609 When writing a package definition, developers typically need to download
9610 a source tarball, compute its SHA256 hash, and write that
9611 hash in the package definition (@pxref{Defining Packages}). The
9612 @command{guix download} tool helps with this task: it downloads a file
9613 from the given URI, adds it to the store, and prints both its file name
9614 in the store and its SHA256 hash.
9616 The fact that the downloaded file is added to the store saves bandwidth:
9617 when the developer eventually tries to build the newly defined package
9618 with @command{guix build}, the source tarball will not have to be
9619 downloaded again because it is already in the store. It is also a
9620 convenient way to temporarily stash files, which may be deleted
9621 eventually (@pxref{Invoking guix gc}).
9623 The @command{guix download} command supports the same URIs as used in
9624 package definitions. In particular, it supports @code{mirror://} URIs.
9625 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
9626 Guile bindings for GnuTLS are available in the user's environment; when
9627 they are not available, an error is raised. @xref{Guile Preparations,
9628 how to install the GnuTLS bindings for Guile,, gnutls-guile,
9629 GnuTLS-Guile}, for more information.
9631 @command{guix download} verifies HTTPS server certificates by loading
9632 the certificates of X.509 authorities from the directory pointed to by
9633 the @env{SSL_CERT_DIR} environment variable (@pxref{X.509
9634 Certificates}), unless @option{--no-check-certificate} is used.
9636 The following options are available:
9639 @item --hash=@var{algorithm}
9640 @itemx -H @var{algorithm}
9641 Compute a hash using the specified @var{algorithm}. @xref{Invoking guix
9642 hash}, for more information.
9644 @item --format=@var{fmt}
9646 Write the hash in the format specified by @var{fmt}. For more
9647 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
9649 @item --no-check-certificate
9650 Do not validate the X.509 certificates of HTTPS servers.
9652 When using this option, you have @emph{absolutely no guarantee} that you
9653 are communicating with the authentic server responsible for the given
9654 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
9656 @item --output=@var{file}
9657 @itemx -o @var{file}
9658 Save the downloaded file to @var{file} instead of adding it to the
9662 @node Invoking guix hash
9663 @section Invoking @command{guix hash}
9665 @cindex @command{guix hash}
9666 The @command{guix hash} command computes the hash of a file.
9667 It is primarily a convenience tool for anyone contributing to the
9668 distribution: it computes the cryptographic hash of a file, which can be
9669 used in the definition of a package (@pxref{Defining Packages}).
9671 The general syntax is:
9674 guix hash @var{option} @var{file}
9677 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
9678 hash of data read from standard input. @command{guix hash} has the
9683 @item --hash=@var{algorithm}
9684 @itemx -H @var{algorithm}
9685 Compute a hash using the specified @var{algorithm}, @code{sha256} by
9688 @var{algorithm} must the name of a cryptographic hash algorithm
9689 supported by Libgcrypt @i{via} Guile-Gcrypt---e.g., @code{sha512} or
9690 @code{sha3-256} (@pxref{Hash Functions,,, guile-gcrypt, Guile-Gcrypt
9693 @item --format=@var{fmt}
9695 Write the hash in the format specified by @var{fmt}.
9697 Supported formats: @code{base64}, @code{nix-base32}, @code{base32}, @code{base16}
9698 (@code{hex} and @code{hexadecimal} can be used as well).
9700 If the @option{--format} option is not specified, @command{guix hash}
9701 will output the hash in @code{nix-base32}. This representation is used
9702 in the definitions of packages.
9706 Compute the hash on @var{file} recursively.
9708 In this case, the hash is computed on an archive containing @var{file},
9709 including its children if it is a directory. Some of the metadata of
9710 @var{file} is part of the archive; for instance, when @var{file} is a
9711 regular file, the hash is different depending on whether @var{file} is
9712 executable or not. Metadata such as time stamps has no impact on the
9713 hash (@pxref{Invoking guix archive}).
9714 @c FIXME: Replace xref above with xref to an ``Archive'' section when
9719 When combined with @option{--recursive}, exclude version control system
9720 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.).
9723 As an example, here is how you would compute the hash of a Git checkout,
9724 which is useful when using the @code{git-fetch} method (@pxref{origin
9728 $ git clone http://example.org/foo.git
9734 @node Invoking guix import
9735 @section Invoking @command{guix import}
9737 @cindex importing packages
9738 @cindex package import
9739 @cindex package conversion
9740 @cindex Invoking @command{guix import}
9741 The @command{guix import} command is useful for people who would like to
9742 add a package to the distribution with as little work as
9743 possible---a legitimate demand. The command knows of a few
9744 repositories from which it can ``import'' package metadata. The result
9745 is a package definition, or a template thereof, in the format we know
9746 (@pxref{Defining Packages}).
9748 The general syntax is:
9751 guix import @var{importer} @var{options}@dots{}
9754 @var{importer} specifies the source from which to import package
9755 metadata, and @var{options} specifies a package identifier and other
9756 options specific to @var{importer}.
9758 Some of the importers rely on the ability to run the @command{gpgv} command.
9759 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
9762 Currently, the available ``importers'' are:
9766 Import metadata for the given GNU package. This provides a template
9767 for the latest version of that GNU package, including the hash of its
9768 source tarball, and its canonical synopsis and description.
9770 Additional information such as the package dependencies and its
9771 license needs to be figured out manually.
9773 For example, the following command returns a package definition for
9777 guix import gnu hello
9780 Specific command-line options are:
9783 @item --key-download=@var{policy}
9784 As for @command{guix refresh}, specify the policy to handle missing
9785 OpenPGP keys when verifying the package signature. @xref{Invoking guix
9786 refresh, @option{--key-download}}.
9791 Import metadata from the @uref{https://pypi.python.org/, Python Package
9792 Index}. Information is taken from the JSON-formatted description
9793 available at @code{pypi.python.org} and usually includes all the relevant
9794 information, including package dependencies. For maximum efficiency, it
9795 is recommended to install the @command{unzip} utility, so that the
9796 importer can unzip Python wheels and gather data from them.
9798 The command below imports metadata for the @code{itsdangerous} Python
9802 guix import pypi itsdangerous
9808 Traverse the dependency graph of the given upstream package recursively
9809 and generate package expressions for all those packages that are not yet
9815 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
9816 is taken from the JSON-formatted description available at
9817 @code{rubygems.org} and includes most relevant information, including
9818 runtime dependencies. There are some caveats, however. The metadata
9819 doesn't distinguish between synopses and descriptions, so the same string
9820 is used for both fields. Additionally, the details of non-Ruby
9821 dependencies required to build native extensions is unavailable and left
9822 as an exercise to the packager.
9824 The command below imports metadata for the @code{rails} Ruby package:
9827 guix import gem rails
9833 Traverse the dependency graph of the given upstream package recursively
9834 and generate package expressions for all those packages that are not yet
9840 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
9841 Information is taken from the JSON-formatted metadata provided through
9842 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
9843 relevant information, such as module dependencies. License information
9844 should be checked closely. If Perl is available in the store, then the
9845 @code{corelist} utility will be used to filter core modules out of the
9846 list of dependencies.
9848 The command command below imports metadata for the Acme::Boolean Perl
9852 guix import cpan Acme::Boolean
9857 @cindex Bioconductor
9858 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
9859 central repository for the @uref{https://r-project.org, GNU@tie{}R
9860 statistical and graphical environment}.
9862 Information is extracted from the @file{DESCRIPTION} file of the package.
9864 The command command below imports metadata for the Cairo R package:
9867 guix import cran Cairo
9870 When @option{--recursive} is added, the importer will traverse the
9871 dependency graph of the given upstream package recursively and generate
9872 package expressions for all those packages that are not yet in Guix.
9874 When @option{--archive=bioconductor} is added, metadata is imported from
9875 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
9876 packages for for the analysis and comprehension of high-throughput
9877 genomic data in bioinformatics.
9879 Information is extracted from the @file{DESCRIPTION} file contained in the
9882 The command below imports metadata for the GenomicRanges R package:
9885 guix import cran --archive=bioconductor GenomicRanges
9888 Finally, you can also import R packages that have not yet been published on
9889 CRAN or Bioconductor as long as they are in a git repository. Use
9890 @option{--archive=git} followed by the URL of the git repository:
9893 guix import cran --archive=git https://github.com/immunogenomics/harmony
9899 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
9900 comprehensive TeX archive network for TeX packages that are part of the
9901 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
9903 Information about the package is obtained through the XML API provided
9904 by CTAN, while the source code is downloaded from the SVN repository of
9905 the Tex Live project. This is done because the CTAN does not keep
9908 The command command below imports metadata for the @code{fontspec}
9912 guix import texlive fontspec
9915 When @option{--archive=@var{directory}} is added, the source code is
9916 downloaded not from the @file{latex} sub-directory of the
9917 @file{texmf-dist/source} tree in the TeX Live SVN repository, but from
9918 the specified sibling @var{directory} under the same root.
9920 The command below imports metadata for the @code{ifxetex} package from
9921 CTAN while fetching the sources from the directory
9922 @file{texmf/source/generic}:
9925 guix import texlive --archive=generic ifxetex
9929 @cindex JSON, import
9930 Import package metadata from a local JSON file. Consider the following
9931 example package definition in JSON format:
9937 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
9938 "build-system": "gnu",
9939 "home-page": "https://www.gnu.org/software/hello/",
9940 "synopsis": "Hello, GNU world: An example GNU package",
9941 "description": "GNU Hello prints a greeting.",
9942 "license": "GPL-3.0+",
9943 "native-inputs": ["gettext"]
9947 The field names are the same as for the @code{<package>} record
9948 (@xref{Defining Packages}). References to other packages are provided
9949 as JSON lists of quoted package specification strings such as
9950 @code{guile} or @code{guile@@2.0}.
9952 The importer also supports a more explicit source definition using the
9953 common fields for @code{<origin>} records:
9959 "method": "url-fetch",
9960 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
9962 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
9969 The command below reads metadata from the JSON file @code{hello.json}
9970 and outputs a package expression:
9973 guix import json hello.json
9977 Import metadata from a local copy of the source of the
9978 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
9979 relies on the @command{nix-instantiate} command of
9980 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
9981 typically written in a mixture of Nix-language and Bash code. This
9982 command only imports the high-level package structure that is written in
9983 the Nix language. It normally includes all the basic fields of a
9986 When importing a GNU package, the synopsis and descriptions are replaced
9987 by their canonical upstream variant.
9989 Usually, you will first need to do:
9992 export NIX_REMOTE=daemon
9996 so that @command{nix-instantiate} does not try to open the Nix database.
9998 As an example, the command below imports the package definition of
9999 LibreOffice (more precisely, it imports the definition of the package
10000 bound to the @code{libreoffice} top-level attribute):
10003 guix import nix ~/path/to/nixpkgs libreoffice
10008 Import metadata from the Haskell community's central package archive
10009 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
10010 Cabal files and includes all the relevant information, including package
10013 Specific command-line options are:
10018 Read a Cabal file from standard input.
10019 @item --no-test-dependencies
10021 Do not include dependencies required only by the test suites.
10022 @item --cabal-environment=@var{alist}
10023 @itemx -e @var{alist}
10024 @var{alist} is a Scheme alist defining the environment in which the
10025 Cabal conditionals are evaluated. The accepted keys are: @code{os},
10026 @code{arch}, @code{impl} and a string representing the name of a flag.
10027 The value associated with a flag has to be either the symbol
10028 @code{true} or @code{false}. The value associated with other keys
10029 has to conform to the Cabal file format definition. The default value
10030 associated with the keys @code{os}, @code{arch} and @code{impl} is
10031 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
10034 Traverse the dependency graph of the given upstream package recursively
10035 and generate package expressions for all those packages that are not yet
10039 The command below imports metadata for the latest version of the
10040 HTTP Haskell package without including test dependencies and
10041 specifying the value of the flag @samp{network-uri} as @code{false}:
10044 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
10047 A specific package version may optionally be specified by following the
10048 package name by an at-sign and a version number as in the following example:
10051 guix import hackage mtl@@2.1.3.1
10056 The @code{stackage} importer is a wrapper around the @code{hackage} one.
10057 It takes a package name, looks up the package version included in a
10058 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
10059 release and uses the @code{hackage} importer to retrieve its metadata.
10060 Note that it is up to you to select an LTS release compatible with the
10061 GHC compiler used by Guix.
10063 Specific command-line options are:
10066 @item --no-test-dependencies
10068 Do not include dependencies required only by the test suites.
10069 @item --lts-version=@var{version}
10070 @itemx -l @var{version}
10071 @var{version} is the desired LTS release version. If omitted the latest
10075 Traverse the dependency graph of the given upstream package recursively
10076 and generate package expressions for all those packages that are not yet
10080 The command below imports metadata for the HTTP Haskell package
10081 included in the LTS Stackage release version 7.18:
10084 guix import stackage --lts-version=7.18 HTTP
10089 Import metadata from an Emacs Lisp Package Archive (ELPA) package
10090 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
10092 Specific command-line options are:
10095 @item --archive=@var{repo}
10096 @itemx -a @var{repo}
10097 @var{repo} identifies the archive repository from which to retrieve the
10098 information. Currently the supported repositories and their identifiers
10102 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
10103 identifier. This is the default.
10105 Packages from @code{elpa.gnu.org} are signed with one of the keys
10106 contained in the GnuPG keyring at
10107 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
10108 @code{emacs} package (@pxref{Package Installation, ELPA package
10109 signatures,, emacs, The GNU Emacs Manual}).
10112 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
10113 @code{melpa-stable} identifier.
10116 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
10122 Traverse the dependency graph of the given upstream package recursively
10123 and generate package expressions for all those packages that are not yet
10129 Import metadata from the crates.io Rust package repository
10130 @uref{https://crates.io, crates.io}, as in this example:
10133 guix import crate blake2-rfc
10136 The crate importer also allows you to specify a version string:
10139 guix import crate constant-time-eq@@0.1.0
10142 Additional options include:
10147 Traverse the dependency graph of the given upstream package recursively
10148 and generate package expressions for all those packages that are not yet
10155 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
10156 repository used by the OCaml community.
10159 The structure of the @command{guix import} code is modular. It would be
10160 useful to have more importers for other package formats, and your help
10161 is welcome here (@pxref{Contributing}).
10163 @node Invoking guix refresh
10164 @section Invoking @command{guix refresh}
10166 @cindex @command {guix refresh}
10167 The primary audience of the @command{guix refresh} command is developers
10168 of the GNU software distribution. By default, it reports any packages
10169 provided by the distribution that are outdated compared to the latest
10170 upstream version, like this:
10174 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
10175 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
10178 Alternatively, one can specify packages to consider, in which case a
10179 warning is emitted for packages that lack an updater:
10182 $ guix refresh coreutils guile guile-ssh
10183 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
10184 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
10187 @command{guix refresh} browses the upstream repository of each package and determines
10188 the highest version number of the releases therein. The command
10189 knows how to update specific types of packages: GNU packages, ELPA
10190 packages, etc.---see the documentation for @option{--type} below. There
10191 are many packages, though, for which it lacks a method to determine
10192 whether a new upstream release is available. However, the mechanism is
10193 extensible, so feel free to get in touch with us to add a new method!
10198 Consider the packages specified, and all the packages upon which they depend.
10201 $ guix refresh --recursive coreutils
10202 gnu/packages/acl.scm:35:2: warning: no updater for acl
10203 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
10204 gnu/packages/xml.scm:68:2: warning: no updater for expat
10205 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
10211 Sometimes the upstream name differs from the package name used in Guix,
10212 and @command{guix refresh} needs a little help. Most updaters honor the
10213 @code{upstream-name} property in package definitions, which can be used
10217 (define-public network-manager
10219 (name "network-manager")
10221 (properties '((upstream-name . "NetworkManager")))))
10224 When passed @option{--update}, it modifies distribution source files to
10225 update the version numbers and source tarball hashes of those package
10226 recipes (@pxref{Defining Packages}). This is achieved by downloading
10227 each package's latest source tarball and its associated OpenPGP
10228 signature, authenticating the downloaded tarball against its signature
10229 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
10230 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
10233 key used to sign the tarball is missing from the user's keyring, an
10234 attempt is made to automatically retrieve it from a public key server;
10235 when this is successful, the key is added to the user's keyring; otherwise,
10236 @command{guix refresh} reports an error.
10238 The following options are supported:
10242 @item --expression=@var{expr}
10243 @itemx -e @var{expr}
10244 Consider the package @var{expr} evaluates to.
10246 This is useful to precisely refer to a package, as in this example:
10249 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
10252 This command lists the dependents of the ``final'' libc (essentially all
10257 Update distribution source files (package recipes) in place. This is
10258 usually run from a checkout of the Guix source tree (@pxref{Running
10259 Guix Before It Is Installed}):
10262 $ ./pre-inst-env guix refresh -s non-core -u
10265 @xref{Defining Packages}, for more information on package definitions.
10267 @item --select=[@var{subset}]
10268 @itemx -s @var{subset}
10269 Select all the packages in @var{subset}, one of @code{core} or
10272 The @code{core} subset refers to all the packages at the core of the
10273 distribution---i.e., packages that are used to build ``everything
10274 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
10275 changing one of these packages in the distribution entails a rebuild of
10276 all the others. Thus, such updates are an inconvenience to users in
10277 terms of build time or bandwidth used to achieve the upgrade.
10279 The @code{non-core} subset refers to the remaining packages. It is
10280 typically useful in cases where an update of the core packages would be
10283 @item --manifest=@var{file}
10284 @itemx -m @var{file}
10285 Select all the packages from the manifest in @var{file}. This is useful to
10286 check if any packages of the user manifest can be updated.
10288 @item --type=@var{updater}
10289 @itemx -t @var{updater}
10290 Select only packages handled by @var{updater} (may be a comma-separated
10291 list of updaters). Currently, @var{updater} may be one of:
10295 the updater for GNU packages;
10297 the updater for packages hosted at @uref{https://savannah.gnu.org, Savannah};
10299 the updater for GNOME packages;
10301 the updater for KDE packages;
10303 the updater for X.org packages;
10305 the updater for packages hosted on kernel.org;
10307 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
10309 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
10311 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
10313 the updater for @uref{https://www.cpan.org/, CPAN} packages;
10315 the updater for @uref{https://pypi.python.org, PyPI} packages.
10317 the updater for @uref{https://rubygems.org, RubyGems} packages.
10319 the updater for @uref{https://github.com, GitHub} packages.
10321 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
10323 the updater for @uref{https://www.stackage.org, Stackage} packages.
10325 the updater for @uref{https://crates.io, Crates} packages.
10327 the updater for @uref{https://launchpad.net, Launchpad} packages.
10330 For instance, the following command only checks for updates of Emacs
10331 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
10334 $ guix refresh --type=elpa,cran
10335 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
10336 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
10341 In addition, @command{guix refresh} can be passed one or more package
10342 names, as in this example:
10345 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
10349 The command above specifically updates the @code{emacs} and
10350 @code{idutils} packages. The @option{--select} option would have no
10351 effect in this case.
10353 When considering whether to upgrade a package, it is sometimes
10354 convenient to know which packages would be affected by the upgrade and
10355 should be checked for compatibility. For this the following option may
10356 be used when passing @command{guix refresh} one or more package names:
10360 @item --list-updaters
10362 List available updaters and exit (see @option{--type} above).
10364 For each updater, display the fraction of packages it covers; at the
10365 end, display the fraction of packages covered by all these updaters.
10367 @item --list-dependent
10369 List top-level dependent packages that would need to be rebuilt as a
10370 result of upgrading one or more packages.
10372 @xref{Invoking guix graph, the @code{reverse-package} type of
10373 @command{guix graph}}, for information on how to visualize the list of
10374 dependents of a package.
10378 Be aware that the @option{--list-dependent} option only
10379 @emph{approximates} the rebuilds that would be required as a result of
10380 an upgrade. More rebuilds might be required under some circumstances.
10383 $ guix refresh --list-dependent flex
10384 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
10385 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
10388 The command above lists a set of packages that could be built to check
10389 for compatibility with an upgraded @code{flex} package.
10393 @item --list-transitive
10394 List all the packages which one or more packages depend upon.
10397 $ guix refresh --list-transitive flex
10398 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
10399 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{}
10404 The command above lists a set of packages which, when changed, would cause
10405 @code{flex} to be rebuilt.
10407 The following options can be used to customize GnuPG operation:
10411 @item --gpg=@var{command}
10412 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
10413 for in @code{$PATH}.
10415 @item --keyring=@var{file}
10416 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
10417 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
10418 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
10419 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
10420 information on a tool to manipulate keybox files).
10422 When this option is omitted, @command{guix refresh} uses
10423 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
10424 signing keys. OpenPGP signatures are checked against keys from this keyring;
10425 missing keys are downloaded to this keyring as well (see
10426 @option{--key-download} below).
10428 You can export keys from your default GPG keyring into a keybox file using
10429 commands like this one:
10432 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
10435 Likewise, you can fetch keys to a specific keybox file like this:
10438 gpg --no-default-keyring --keyring mykeyring.kbx \
10439 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
10442 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
10443 Privacy Guard}, for more information on GPG's @option{--keyring} option.
10445 @item --key-download=@var{policy}
10446 Handle missing OpenPGP keys according to @var{policy}, which may be one
10451 Always download missing OpenPGP keys from the key server, and add them
10452 to the user's GnuPG keyring.
10455 Never try to download missing OpenPGP keys. Instead just bail out.
10458 When a package signed with an unknown OpenPGP key is encountered, ask
10459 the user whether to download it or not. This is the default behavior.
10462 @item --key-server=@var{host}
10463 Use @var{host} as the OpenPGP key server when importing a public key.
10465 @item --load-path=@var{directory}
10466 Add @var{directory} to the front of the package module search path
10467 (@pxref{Package Modules}).
10469 This allows users to define their own packages and make them visible to
10470 the command-line tools.
10474 The @code{github} updater uses the
10475 @uref{https://developer.github.com/v3/, GitHub API} to query for new
10476 releases. When used repeatedly e.g.@: when refreshing all packages,
10477 GitHub will eventually refuse to answer any further API requests. By
10478 default 60 API requests per hour are allowed, and a full refresh on all
10479 GitHub packages in Guix requires more than this. Authentication with
10480 GitHub through the use of an API token alleviates these limits. To use
10481 an API token, set the environment variable @env{GUIX_GITHUB_TOKEN} to a
10482 token procured from @uref{https://github.com/settings/tokens} or
10486 @node Invoking guix lint
10487 @section Invoking @command{guix lint}
10489 @cindex @command{guix lint}
10490 @cindex package, checking for errors
10491 The @command{guix lint} command is meant to help package developers avoid
10492 common errors and use a consistent style. It runs a number of checks on
10493 a given set of packages in order to find common mistakes in their
10494 definitions. Available @dfn{checkers} include (see
10495 @option{--list-checkers} for a complete list):
10500 Validate certain typographical and stylistic rules about package
10501 descriptions and synopses.
10503 @item inputs-should-be-native
10504 Identify inputs that should most likely be native inputs.
10510 @itemx source-file-name
10511 Probe @code{home-page} and @code{source} URLs and report those that are
10512 invalid. Suggest a @code{mirror://} URL when applicable. If the
10513 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
10514 URL. Check that the source file name is meaningful, e.g.@: is not just a
10515 version number or ``git-checkout'', without a declared @code{file-name}
10516 (@pxref{origin Reference}).
10518 @item source-unstable-tarball
10519 Parse the @code{source} URL to determine if a tarball from GitHub is
10520 autogenerated or if it is a release tarball. Unfortunately GitHub's
10521 autogenerated tarballs are sometimes regenerated.
10524 Check that the derivation of the given packages can be successfully
10525 computed for all the supported systems (@pxref{Derivations}).
10527 @item profile-collisions
10528 Check whether installing the given packages in a profile would lead to
10529 collisions. Collisions occur when several packages with the same name
10530 but a different version or a different store file name are propagated.
10531 @xref{package Reference, @code{propagated-inputs}}, for more information
10532 on propagated inputs.
10535 @cindex Software Heritage, source code archive
10536 @cindex archival of source code, Software Heritage
10537 Checks whether the package's source code is archived at
10538 @uref{https://www.softwareheritage.org, Software Heritage}.
10540 When the source code that is not archived comes from a version-control system
10541 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
10542 ``save'' request so that it eventually archives it. This ensures that the
10543 source will remain available in the long term, and that Guix can fall back to
10544 Software Heritage should the source code disappear from its original host.
10545 The status of recent ``save'' requests can be
10546 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
10548 When source code is a tarball obtained with @code{url-fetch}, simply print a
10549 message when it is not archived. As of this writing, Software Heritage does
10550 not allow requests to save arbitrary tarballs; we are working on ways to
10551 ensure that non-VCS source code is also archived.
10554 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
10555 request rate per IP address}. When the limit is reached, @command{guix lint}
10556 prints a message and the @code{archival} checker stops doing anything until
10557 that limit has been reset.
10560 @cindex security vulnerabilities
10561 @cindex CVE, Common Vulnerabilities and Exposures
10562 Report known vulnerabilities found in the Common Vulnerabilities and
10563 Exposures (CVE) databases of the current and past year
10564 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
10567 To view information about a particular vulnerability, visit pages such as:
10571 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
10573 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
10577 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
10578 @code{CVE-2015-7554}.
10580 Package developers can specify in package recipes the
10581 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
10582 name and version of the package when they differ from the name or version
10583 that Guix uses, as in this example:
10589 ;; CPE calls this package "grub2".
10590 (properties '((cpe-name . "grub2")
10591 (cpe-version . "2.3"))))
10594 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
10595 Some entries in the CVE database do not specify which version of a
10596 package they apply to, and would thus ``stick around'' forever. Package
10597 developers who found CVE alerts and verified they can be ignored can
10598 declare them as in this example:
10604 ;; These CVEs no longer apply and can be safely ignored.
10605 (properties `((lint-hidden-cve . ("CVE-2011-0433"
10608 "CVE-2011-5244")))))
10612 Warn about obvious source code formatting issues: trailing white space,
10613 use of tabulations, etc.
10616 The general syntax is:
10619 guix lint @var{options} @var{package}@dots{}
10622 If no package is given on the command line, then all packages are checked.
10623 The @var{options} may be zero or more of the following:
10626 @item --list-checkers
10628 List and describe all the available checkers that will be run on packages
10633 Only enable the checkers specified in a comma-separated list using the
10634 names returned by @option{--list-checkers}.
10636 @item --load-path=@var{directory}
10637 @itemx -L @var{directory}
10638 Add @var{directory} to the front of the package module search path
10639 (@pxref{Package Modules}).
10641 This allows users to define their own packages and make them visible to
10642 the command-line tools.
10646 @node Invoking guix size
10647 @section Invoking @command{guix size}
10650 @cindex package size
10652 @cindex @command{guix size}
10653 The @command{guix size} command helps package developers profile the
10654 disk usage of packages. It is easy to overlook the impact of an
10655 additional dependency added to a package, or the impact of using a
10656 single output for a package that could easily be split (@pxref{Packages
10657 with Multiple Outputs}). Such are the typical issues that
10658 @command{guix size} can highlight.
10660 The command can be passed one or more package specifications
10661 such as @code{gcc@@4.8}
10662 or @code{guile:debug}, or a file name in the store. Consider this
10666 $ guix size coreutils
10667 store item total self
10668 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
10669 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
10670 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
10671 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
10672 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
10673 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
10674 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
10675 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
10680 The store items listed here constitute the @dfn{transitive closure} of
10681 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
10682 would be returned by:
10685 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
10688 Here the output shows three columns next to store items. The first column,
10689 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
10690 the store item---that is, its own size plus the size of all its
10691 dependencies. The next column, labeled ``self'', shows the size of the
10692 item itself. The last column shows the ratio of the size of the item
10693 itself to the space occupied by all the items listed here.
10695 In this example, we see that the closure of Coreutils weighs in at
10696 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
10697 libraries. (That libc and GCC's libraries represent a large fraction of
10698 the closure is not a problem @i{per se} because they are always available
10699 on the system anyway.)
10701 Since the command also accepts store file names, assessing the size of
10702 a build result is straightforward:
10705 guix size $(guix system build config.scm)
10708 When the package(s) passed to @command{guix size} are available in the
10709 store@footnote{More precisely, @command{guix size} looks for the
10710 @emph{ungrafted} variant of the given package(s), as returned by
10711 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
10712 for information on grafts.}, @command{guix size} queries the daemon to determine its
10713 dependencies, and measures its size in the store, similar to @command{du
10714 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
10717 When the given packages are @emph{not} in the store, @command{guix size}
10718 reports information based on the available substitutes
10719 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
10720 store items that are not even on disk, only available remotely.
10722 You can also specify several package names:
10725 $ guix size coreutils grep sed bash
10726 store item total self
10727 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
10728 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
10729 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
10730 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
10736 In this example we see that the combination of the four packages takes
10737 102.3@tie{}MiB in total, which is much less than the sum of each closure
10738 since they have a lot of dependencies in common.
10740 When looking at the profile returned by @command{guix size}, you may
10741 find yourself wondering why a given package shows up in the profile at
10742 all. To understand it, you can use @command{guix graph --path -t
10743 references} to display the shortest path between the two packages
10744 (@pxref{Invoking guix graph}).
10746 The available options are:
10750 @item --substitute-urls=@var{urls}
10751 Use substitute information from @var{urls}.
10752 @xref{client-substitute-urls, the same option for @code{guix build}}.
10754 @item --sort=@var{key}
10755 Sort lines according to @var{key}, one of the following options:
10759 the size of each item (the default);
10761 the total size of the item's closure.
10764 @item --map-file=@var{file}
10765 Write a graphical map of disk usage in PNG format to @var{file}.
10767 For the example above, the map looks like this:
10769 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
10770 produced by @command{guix size}}
10772 This option requires that
10773 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
10774 installed and visible in Guile's module search path. When that is not
10775 the case, @command{guix size} fails as it tries to load it.
10777 @item --system=@var{system}
10778 @itemx -s @var{system}
10779 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
10781 @item --load-path=@var{directory}
10782 @itemx -L @var{directory}
10783 Add @var{directory} to the front of the package module search path
10784 (@pxref{Package Modules}).
10786 This allows users to define their own packages and make them visible to
10787 the command-line tools.
10790 @node Invoking guix graph
10791 @section Invoking @command{guix graph}
10794 @cindex @command{guix graph}
10795 @cindex package dependencies
10796 Packages and their dependencies form a @dfn{graph}, specifically a
10797 directed acyclic graph (DAG). It can quickly become difficult to have a
10798 mental model of the package DAG, so the @command{guix graph} command
10799 provides a visual representation of the DAG. By default,
10800 @command{guix graph} emits a DAG representation in the input format of
10801 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
10802 directly to the @command{dot} command of Graphviz. It can also emit an
10803 HTML page with embedded JavaScript code to display a ``chord diagram''
10804 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
10805 emit Cypher queries to construct a graph in a graph database supporting
10806 the @uref{https://www.opencypher.org/, openCypher} query language. With
10807 @option{--path}, it simply displays the shortest path between two
10808 packages. The general syntax is:
10811 guix graph @var{options} @var{package}@dots{}
10814 For example, the following command generates a PDF file representing the
10815 package DAG for the GNU@tie{}Core Utilities, showing its build-time
10819 guix graph coreutils | dot -Tpdf > dag.pdf
10822 The output looks like this:
10824 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
10826 Nice little graph, no?
10828 You may find it more pleasant to navigate the graph interactively with
10829 @command{xdot} (from the @code{xdot} package):
10832 guix graph coreutils | xdot -
10835 But there is more than one graph! The one above is concise: it is the
10836 graph of package objects, omitting implicit inputs such as GCC, libc,
10837 grep, etc. It is often useful to have such a concise graph, but
10838 sometimes one may want to see more details. @command{guix graph} supports
10839 several types of graphs, allowing you to choose the level of detail:
10843 This is the default type used in the example above. It shows the DAG of
10844 package objects, excluding implicit dependencies. It is concise, but
10845 filters out many details.
10847 @item reverse-package
10848 This shows the @emph{reverse} DAG of packages. For example:
10851 guix graph --type=reverse-package ocaml
10854 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
10855 you are also interested in cases where OCaml is an implicit dependency, see
10856 @code{reverse-bag} below).
10858 Note that for core packages this can yield huge graphs. If all you want
10859 is to know the number of packages that depend on a given package, use
10860 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
10861 @option{--list-dependent}}).
10864 This is the package DAG, @emph{including} implicit inputs.
10866 For instance, the following command:
10869 guix graph --type=bag-emerged coreutils
10872 ...@: yields this bigger graph:
10874 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
10876 At the bottom of the graph, we see all the implicit inputs of
10877 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
10879 Now, note that the dependencies of these implicit inputs---that is, the
10880 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
10881 here, for conciseness.
10884 Similar to @code{bag-emerged}, but this time including all the bootstrap
10887 @item bag-with-origins
10888 Similar to @code{bag}, but also showing origins and their dependencies.
10891 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
10892 it also takes implicit dependencies into account. For example:
10895 guix graph -t reverse-bag dune
10899 ...@: yields the graph of all packages that depend on Dune, directly or
10900 indirectly. Since Dune is an @emph{implicit} dependency of many packages
10901 @i{via} @code{dune-build-system}, this shows a large number of packages,
10902 whereas @code{reverse-package} would show very few if any.
10905 This is the most detailed representation: It shows the DAG of
10906 derivations (@pxref{Derivations}) and plain store items. Compared to
10907 the above representation, many additional nodes are visible, including
10908 build scripts, patches, Guile modules, etc.
10910 For this type of graph, it is also possible to pass a @file{.drv} file
10911 name instead of a package name, as in:
10914 guix graph -t derivation `guix system build -d my-config.scm`
10918 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
10919 For example, the following command shows the graph for the package
10920 module that defines the @code{guile} package:
10923 guix graph -t module guile | xdot -
10927 All the types above correspond to @emph{build-time dependencies}. The
10928 following graph type represents the @emph{run-time dependencies}:
10932 This is the graph of @dfn{references} of a package output, as returned
10933 by @command{guix gc --references} (@pxref{Invoking guix gc}).
10935 If the given package output is not available in the store, @command{guix
10936 graph} attempts to obtain dependency information from substitutes.
10938 Here you can also pass a store file name instead of a package name. For
10939 example, the command below produces the reference graph of your profile
10940 (which can be big!):
10943 guix graph -t references `readlink -f ~/.guix-profile`
10947 This is the graph of the @dfn{referrers} of a store item, as returned by
10948 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
10950 This relies exclusively on local information from your store. For
10951 instance, let us suppose that the current Inkscape is available in 10
10952 profiles on your machine; @command{guix graph -t referrers inkscape}
10953 will show a graph rooted at Inkscape and with those 10 profiles linked
10956 It can help determine what is preventing a store item from being garbage
10961 @cindex shortest path, between packages
10962 Often, the graph of the package you are interested in does not fit on
10963 your screen, and anyway all you want to know is @emph{why} that package
10964 actually depends on some seemingly unrelated package. The
10965 @option{--path} option instructs @command{guix graph} to display the
10966 shortest path between two packages (or derivations, or store items,
10970 $ guix graph --path emacs libunistring
10973 libunistring@@0.9.10
10974 $ guix graph --path -t derivation emacs libunistring
10975 /gnu/store/@dots{}-emacs-26.3.drv
10976 /gnu/store/@dots{}-mailutils-3.9.drv
10977 /gnu/store/@dots{}-libunistring-0.9.10.drv
10978 $ guix graph --path -t references emacs libunistring
10979 /gnu/store/@dots{}-emacs-26.3
10980 /gnu/store/@dots{}-libidn2-2.2.0
10981 /gnu/store/@dots{}-libunistring-0.9.10
10984 The available options are the following:
10987 @item --type=@var{type}
10988 @itemx -t @var{type}
10989 Produce a graph output of @var{type}, where @var{type} must be one of
10990 the values listed above.
10993 List the supported graph types.
10995 @item --backend=@var{backend}
10996 @itemx -b @var{backend}
10997 Produce a graph using the selected @var{backend}.
10999 @item --list-backends
11000 List the supported graph backends.
11002 Currently, the available backends are Graphviz and d3.js.
11005 Display the shortest path between two nodes of the type specified by
11006 @option{--type}. The example below shows the shortest path between
11007 @code{libreoffice} and @code{llvm} according to the references of
11008 @code{libreoffice}:
11011 $ guix graph --path -t references libreoffice llvm
11012 /gnu/store/@dots{}-libreoffice-6.4.2.2
11013 /gnu/store/@dots{}-libepoxy-1.5.4
11014 /gnu/store/@dots{}-mesa-19.3.4
11015 /gnu/store/@dots{}-llvm-9.0.1
11018 @item --expression=@var{expr}
11019 @itemx -e @var{expr}
11020 Consider the package @var{expr} evaluates to.
11022 This is useful to precisely refer to a package, as in this example:
11025 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
11028 @item --system=@var{system}
11029 @itemx -s @var{system}
11030 Display the graph for @var{system}---e.g., @code{i686-linux}.
11032 The package dependency graph is largely architecture-independent, but there
11033 are some architecture-dependent bits that this option allows you to visualize.
11035 @item --load-path=@var{directory}
11036 @itemx -L @var{directory}
11037 Add @var{directory} to the front of the package module search path
11038 (@pxref{Package Modules}).
11040 This allows users to define their own packages and make them visible to
11041 the command-line tools.
11044 On top of that, @command{guix graph} supports all the usual package
11045 transformation options (@pxref{Package Transformation Options}). This
11046 makes it easy to view the effect of a graph-rewriting transformation
11047 such as @option{--with-input}. For example, the command below outputs
11048 the graph of @code{git} once @code{openssl} has been replaced by
11049 @code{libressl} everywhere in the graph:
11052 guix graph git --with-input=openssl=libressl
11055 So many possibilities, so much fun!
11057 @node Invoking guix publish
11058 @section Invoking @command{guix publish}
11060 @cindex @command{guix publish}
11061 The purpose of @command{guix publish} is to enable users to easily share
11062 their store with others, who can then use it as a substitute server
11063 (@pxref{Substitutes}).
11065 When @command{guix publish} runs, it spawns an HTTP server which allows
11066 anyone with network access to obtain substitutes from it. This means
11067 that any machine running Guix can also act as if it were a build farm,
11068 since the HTTP interface is compatible with Cuirass, the software behind
11069 the @code{@value{SUBSTITUTE-SERVER}} build farm.
11071 For security, each substitute is signed, allowing recipients to check
11072 their authenticity and integrity (@pxref{Substitutes}). Because
11073 @command{guix publish} uses the signing key of the system, which is only
11074 readable by the system administrator, it must be started as root; the
11075 @option{--user} option makes it drop root privileges early on.
11077 The signing key pair must be generated before @command{guix publish} is
11078 launched, using @command{guix archive --generate-key} (@pxref{Invoking
11081 The general syntax is:
11084 guix publish @var{options}@dots{}
11087 Running @command{guix publish} without any additional arguments will
11088 spawn an HTTP server on port 8080:
11094 Once a publishing server has been authorized (@pxref{Invoking guix
11095 archive}), the daemon may download substitutes from it:
11098 guix-daemon --substitute-urls=http://example.org:8080
11101 By default, @command{guix publish} compresses archives on the fly as it
11102 serves them. This ``on-the-fly'' mode is convenient in that it requires
11103 no setup and is immediately available. However, when serving lots of
11104 clients, we recommend using the @option{--cache} option, which enables
11105 caching of the archives before they are sent to clients---see below for
11106 details. The @command{guix weather} command provides a handy way to
11107 check what a server provides (@pxref{Invoking guix weather}).
11109 As a bonus, @command{guix publish} also serves as a content-addressed
11110 mirror for source files referenced in @code{origin} records
11111 (@pxref{origin Reference}). For instance, assuming @command{guix
11112 publish} is running on @code{example.org}, the following URL returns the
11113 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
11114 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
11117 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
11120 Obviously, these URLs only work for files that are in the store; in
11121 other cases, they return 404 (``Not Found'').
11123 @cindex build logs, publication
11124 Build logs are available from @code{/log} URLs like:
11127 http://example.org/log/gwspk@dots{}-guile-2.2.3
11131 When @command{guix-daemon} is configured to save compressed build logs,
11132 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
11133 URLs return the compressed log as-is, with an appropriate
11134 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
11135 running @command{guix-daemon} with @option{--log-compression=gzip} since
11136 Web browsers can automatically decompress it, which is not the case with
11139 The following options are available:
11142 @item --port=@var{port}
11143 @itemx -p @var{port}
11144 Listen for HTTP requests on @var{port}.
11146 @item --listen=@var{host}
11147 Listen on the network interface for @var{host}. The default is to
11148 accept connections from any interface.
11150 @item --user=@var{user}
11151 @itemx -u @var{user}
11152 Change privileges to @var{user} as soon as possible---i.e., once the
11153 server socket is open and the signing key has been read.
11155 @item --compression[=@var{method}[:@var{level}]]
11156 @itemx -C [@var{method}[:@var{level}]]
11157 Compress data using the given @var{method} and @var{level}. @var{method} is
11158 one of @code{lzip} and @code{gzip}; when @var{method} is omitted, @code{gzip}
11161 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
11162 to different compression levels: 1 is the fastest, and 9 is the best
11163 (CPU-intensive). The default is 3.
11165 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a small
11166 increase in CPU usage; see
11167 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip Web
11170 Unless @option{--cache} is used, compression occurs on the fly and
11171 the compressed streams are not
11172 cached. Thus, to reduce load on the machine that runs @command{guix
11173 publish}, it may be a good idea to choose a low compression level, to
11174 run @command{guix publish} behind a caching proxy, or to use
11175 @option{--cache}. Using @option{--cache} has the advantage that it
11176 allows @command{guix publish} to add @code{Content-Length} HTTP header
11179 This option can be repeated, in which case every substitute gets compressed
11180 using all the selected methods, and all of them are advertised. This is
11181 useful when users may not support all the compression methods: they can select
11182 the one they support.
11184 @item --cache=@var{directory}
11185 @itemx -c @var{directory}
11186 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
11187 and only serve archives that are in cache.
11189 When this option is omitted, archives and meta-data are created
11190 on-the-fly. This can reduce the available bandwidth, especially when
11191 compression is enabled, since this may become CPU-bound. Another
11192 drawback of the default mode is that the length of archives is not known
11193 in advance, so @command{guix publish} does not add a
11194 @code{Content-Length} HTTP header to its responses, which in turn
11195 prevents clients from knowing the amount of data being downloaded.
11197 Conversely, when @option{--cache} is used, the first request for a store
11198 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
11199 background process to @dfn{bake} the archive---computing its
11200 @code{.narinfo} and compressing the archive, if needed. Once the
11201 archive is cached in @var{directory}, subsequent requests succeed and
11202 are served directly from the cache, which guarantees that clients get
11203 the best possible bandwidth.
11205 The ``baking'' process is performed by worker threads. By default, one
11206 thread per CPU core is created, but this can be customized. See
11207 @option{--workers} below.
11209 When @option{--ttl} is used, cached entries are automatically deleted
11210 when they have expired.
11212 @item --workers=@var{N}
11213 When @option{--cache} is used, request the allocation of @var{N} worker
11214 threads to ``bake'' archives.
11216 @item --ttl=@var{ttl}
11217 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
11218 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
11219 days, @code{1m} means 1 month, and so on.
11221 This allows the user's Guix to keep substitute information in cache for
11222 @var{ttl}. However, note that @code{guix publish} does not itself
11223 guarantee that the store items it provides will indeed remain available
11224 for as long as @var{ttl}.
11226 Additionally, when @option{--cache} is used, cached entries that have
11227 not been accessed for @var{ttl} and that no longer have a corresponding
11228 item in the store, may be deleted.
11230 @item --nar-path=@var{path}
11231 Use @var{path} as the prefix for the URLs of ``nar'' files
11232 (@pxref{Invoking guix archive, normalized archives}).
11234 By default, nars are served at a URL such as
11235 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
11236 change the @code{/nar} part to @var{path}.
11238 @item --public-key=@var{file}
11239 @itemx --private-key=@var{file}
11240 Use the specific @var{file}s as the public/private key pair used to sign
11241 the store items being published.
11243 The files must correspond to the same key pair (the private key is used
11244 for signing and the public key is merely advertised in the signature
11245 metadata). They must contain keys in the canonical s-expression format
11246 as produced by @command{guix archive --generate-key} (@pxref{Invoking
11247 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
11248 @file{/etc/guix/signing-key.sec} are used.
11250 @item --repl[=@var{port}]
11251 @itemx -r [@var{port}]
11252 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
11253 Reference Manual}) on @var{port} (37146 by default). This is used
11254 primarily for debugging a running @command{guix publish} server.
11257 Enabling @command{guix publish} on Guix System is a one-liner: just
11258 instantiate a @code{guix-publish-service-type} service in the @code{services} field
11259 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
11260 @code{guix-publish-service-type}}).
11262 If you are instead running Guix on a ``foreign distro'', follow these
11267 If your host distro uses the systemd init system:
11270 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
11271 /etc/systemd/system/
11272 # systemctl start guix-publish && systemctl enable guix-publish
11276 If your host distro uses the Upstart init system:
11279 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
11280 # start guix-publish
11284 Otherwise, proceed similarly with your distro's init system.
11287 @node Invoking guix challenge
11288 @section Invoking @command{guix challenge}
11290 @cindex reproducible builds
11291 @cindex verifiable builds
11292 @cindex @command{guix challenge}
11294 Do the binaries provided by this server really correspond to the source
11295 code it claims to build? Is a package build process deterministic?
11296 These are the questions the @command{guix challenge} command attempts to
11299 The former is obviously an important question: Before using a substitute
11300 server (@pxref{Substitutes}), one had better @emph{verify} that it
11301 provides the right binaries, and thus @emph{challenge} it. The latter
11302 is what enables the former: If package builds are deterministic, then
11303 independent builds of the package should yield the exact same result,
11304 bit for bit; if a server provides a binary different from the one
11305 obtained locally, it may be either corrupt or malicious.
11307 We know that the hash that shows up in @file{/gnu/store} file names is
11308 the hash of all the inputs of the process that built the file or
11309 directory---compilers, libraries, build scripts,
11310 etc. (@pxref{Introduction}). Assuming deterministic build processes,
11311 one store file name should map to exactly one build output.
11312 @command{guix challenge} checks whether there is, indeed, a single
11313 mapping by comparing the build outputs of several independent builds of
11314 any given store item.
11316 The command output looks like this:
11319 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
11320 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
11321 updating list of substitutes from 'https://guix.example.org'... 100.0%
11322 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
11323 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
11324 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
11325 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
11327 /lib/libcrypto.so.1.1
11330 /gnu/store/@dots{}-git-2.5.0 contents differ:
11331 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
11332 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
11333 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
11335 /libexec/git-core/git-fsck
11337 /gnu/store/@dots{}-pius-2.1.1 contents differ:
11338 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
11339 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
11340 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
11342 /share/man/man1/pius.1.gz
11346 6,406 store items were analyzed:
11347 - 4,749 (74.1%) were identical
11348 - 525 (8.2%) differed
11349 - 1,132 (17.7%) were inconclusive
11353 In this example, @command{guix challenge} first scans the store to
11354 determine the set of locally-built derivations---as opposed to store
11355 items that were downloaded from a substitute server---and then queries
11356 all the substitute servers. It then reports those store items for which
11357 the servers obtained a result different from the local build.
11359 @cindex non-determinism, in package builds
11360 As an example, @code{guix.example.org} always gets a different answer.
11361 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
11362 case of Git. This might indicate that the build process of Git is
11363 non-deterministic, meaning that its output varies as a function of
11364 various things that Guix does not fully control, in spite of building
11365 packages in isolated environments (@pxref{Features}). Most common
11366 sources of non-determinism include the addition of timestamps in build
11367 results, the inclusion of random numbers, and directory listings sorted
11368 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
11371 To find out what is wrong with this Git binary, the easiest approach is
11375 guix challenge git \
11376 --diff=diffoscope \
11377 --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
11380 This automatically invokes @command{diffoscope}, which displays detailed
11381 information about files that differ.
11383 Alternatively, we can do something along these lines (@pxref{Invoking guix
11387 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-git-2.5.0 \
11388 | lzip -d | guix archive -x /tmp/git
11389 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
11392 This command shows the difference between the files resulting from the
11393 local build, and the files resulting from the build on
11394 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
11395 diffutils, Comparing and Merging Files}). The @command{diff} command
11396 works great for text files. When binary files differ, a better option
11397 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
11398 visualize differences for all kinds of files.
11400 Once you have done that work, you can tell whether the differences are due
11401 to a non-deterministic build process or to a malicious server. We try
11402 hard to remove sources of non-determinism in packages to make it easier
11403 to verify substitutes, but of course, this is a process that
11404 involves not just Guix, but a large part of the free software community.
11405 In the meantime, @command{guix challenge} is one tool to help address
11408 If you are writing packages for Guix, you are encouraged to check
11409 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
11410 same build result as you did with:
11413 $ guix challenge @var{package}
11417 where @var{package} is a package specification such as
11418 @code{guile@@2.0} or @code{glibc:debug}.
11420 The general syntax is:
11423 guix challenge @var{options} [@var{packages}@dots{}]
11426 When a difference is found between the hash of a locally-built item and
11427 that of a server-provided substitute, or among substitutes provided by
11428 different servers, the command displays it as in the example above and
11429 its exit code is 2 (other non-zero exit codes denote other kinds of
11432 The one option that matters is:
11436 @item --substitute-urls=@var{urls}
11437 Consider @var{urls} the whitespace-separated list of substitute source
11438 URLs to compare to.
11440 @item --diff=@var{mode}
11441 Upon mismatches, show differences according to @var{mode}, one of:
11444 @item @code{simple} (the default)
11445 Show the list of files that differ.
11447 @item @code{diffoscope}
11448 @itemx @var{command}
11449 Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
11450 two directories whose contents do not match.
11452 When @var{command} is an absolute file name, run @var{command} instead
11456 Do not show further details about the differences.
11459 Thus, unless @option{--diff=none} is passed, @command{guix challenge}
11460 downloads the store items from the given substitute servers so that it
11465 Show details about matches (identical contents) in addition to
11466 information about mismatches.
11470 @node Invoking guix copy
11471 @section Invoking @command{guix copy}
11473 @cindex copy, of store items, over SSH
11474 @cindex SSH, copy of store items
11475 @cindex sharing store items across machines
11476 @cindex transferring store items across machines
11477 The @command{guix copy} command copies items from the store of one
11478 machine to that of another machine over a secure shell (SSH)
11479 connection@footnote{This command is available only when Guile-SSH was
11480 found. @xref{Requirements}, for details.}. For example, the following
11481 command copies the @code{coreutils} package, the user's profile, and all
11482 their dependencies over to @var{host}, logged in as @var{user}:
11485 guix copy --to=@var{user}@@@var{host} \
11486 coreutils `readlink -f ~/.guix-profile`
11489 If some of the items to be copied are already present on @var{host},
11490 they are not actually sent.
11492 The command below retrieves @code{libreoffice} and @code{gimp} from
11493 @var{host}, assuming they are available there:
11496 guix copy --from=@var{host} libreoffice gimp
11499 The SSH connection is established using the Guile-SSH client, which is
11500 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
11501 @file{~/.ssh/config}, and uses the SSH agent for authentication.
11503 The key used to sign items that are sent must be accepted by the remote
11504 machine. Likewise, the key used by the remote machine to sign items you
11505 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
11506 own daemon. @xref{Invoking guix archive}, for more information about
11507 store item authentication.
11509 The general syntax is:
11512 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
11515 You must always specify one of the following options:
11518 @item --to=@var{spec}
11519 @itemx --from=@var{spec}
11520 Specify the host to send to or receive from. @var{spec} must be an SSH
11521 spec such as @code{example.org}, @code{charlie@@example.org}, or
11522 @code{charlie@@example.org:2222}.
11525 The @var{items} can be either package names, such as @code{gimp}, or
11526 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
11528 When specifying the name of a package to send, it is first built if
11529 needed, unless @option{--dry-run} was specified. Common build options
11530 are supported (@pxref{Common Build Options}).
11533 @node Invoking guix container
11534 @section Invoking @command{guix container}
11536 @cindex @command{guix container}
11538 As of version @value{VERSION}, this tool is experimental. The interface
11539 is subject to radical change in the future.
11542 The purpose of @command{guix container} is to manipulate processes
11543 running within an isolated environment, commonly known as a
11544 ``container'', typically created by the @command{guix environment}
11545 (@pxref{Invoking guix environment}) and @command{guix system container}
11546 (@pxref{Invoking guix system}) commands.
11548 The general syntax is:
11551 guix container @var{action} @var{options}@dots{}
11554 @var{action} specifies the operation to perform with a container, and
11555 @var{options} specifies the context-specific arguments for the action.
11557 The following actions are available:
11561 Execute a command within the context of a running container.
11566 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
11569 @var{pid} specifies the process ID of the running container.
11570 @var{program} specifies an executable file name within the root file
11571 system of the container. @var{arguments} are the additional options that
11572 will be passed to @var{program}.
11574 The following command launches an interactive login shell inside a
11575 Guix system container, started by @command{guix system container}, and whose
11576 process ID is 9001:
11579 guix container exec 9001 /run/current-system/profile/bin/bash --login
11582 Note that the @var{pid} cannot be the parent process of a container. It
11583 must be PID 1 of the container or one of its child processes.
11587 @node Invoking guix weather
11588 @section Invoking @command{guix weather}
11590 Occasionally you're grumpy because substitutes are lacking and you end
11591 up building packages by yourself (@pxref{Substitutes}). The
11592 @command{guix weather} command reports on substitute availability on the
11593 specified servers so you can have an idea of whether you'll be grumpy
11594 today. It can sometimes be useful info as a user, but it is primarily
11595 useful to people running @command{guix publish} (@pxref{Invoking guix
11598 @cindex statistics, for substitutes
11599 @cindex availability of substitutes
11600 @cindex substitute availability
11601 @cindex weather, substitute availability
11602 Here's a sample run:
11605 $ guix weather --substitute-urls=https://guix.example.org
11606 computing 5,872 package derivations for x86_64-linux...
11607 looking for 6,128 store items on https://guix.example.org..
11608 updating list of substitutes from 'https://guix.example.org'... 100.0%
11609 https://guix.example.org
11610 43.4% substitutes available (2,658 out of 6,128)
11611 7,032.5 MiB of nars (compressed)
11612 19,824.2 MiB on disk (uncompressed)
11613 0.030 seconds per request (182.9 seconds in total)
11614 33.5 requests per second
11616 9.8% (342 out of 3,470) of the missing items are queued
11618 x86_64-linux: 518 (59.7%)
11619 i686-linux: 221 (25.5%)
11620 aarch64-linux: 128 (14.8%)
11621 build rate: 23.41 builds per hour
11622 x86_64-linux: 11.16 builds per hour
11623 i686-linux: 6.03 builds per hour
11624 aarch64-linux: 6.41 builds per hour
11627 @cindex continuous integration, statistics
11628 As you can see, it reports the fraction of all the packages for which
11629 substitutes are available on the server---regardless of whether
11630 substitutes are enabled, and regardless of whether this server's signing
11631 key is authorized. It also reports the size of the compressed archives
11632 (``nars'') provided by the server, the size the corresponding store
11633 items occupy in the store (assuming deduplication is turned off), and
11634 the server's throughput. The second part gives continuous integration
11635 (CI) statistics, if the server supports it. In addition, using the
11636 @option{--coverage} option, @command{guix weather} can list ``important''
11637 package substitutes missing on the server (see below).
11639 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
11640 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
11641 challenge}, it ignores signatures on those substitutes, which is
11642 innocuous since the command only gathers statistics and cannot install
11645 The general syntax is:
11648 guix weather @var{options}@dots{} [@var{packages}@dots{}]
11651 When @var{packages} is omitted, @command{guix weather} checks the availability
11652 of substitutes for @emph{all} the packages, or for those specified with
11653 @option{--manifest}; otherwise it only considers the specified packages. It
11654 is also possible to query specific system types with @option{--system}.
11655 @command{guix weather} exits with a non-zero code when the fraction of
11656 available substitutes is below 100%.
11658 The available options are listed below.
11661 @item --substitute-urls=@var{urls}
11662 @var{urls} is the space-separated list of substitute server URLs to
11663 query. When this option is omitted, the default set of substitute
11664 servers is queried.
11666 @item --system=@var{system}
11667 @itemx -s @var{system}
11668 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
11669 option can be repeated, in which case @command{guix weather} will query
11670 substitutes for several system types.
11672 @item --manifest=@var{file}
11673 Instead of querying substitutes for all the packages, only ask for those
11674 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
11675 with the @code{-m} option of @command{guix package} (@pxref{Invoking
11678 This option can be repeated several times, in which case the manifests
11681 @item --coverage[=@var{count}]
11682 @itemx -c [@var{count}]
11683 Report on substitute coverage for packages: list packages with at least
11684 @var{count} dependents (zero by default) for which substitutes are
11685 unavailable. Dependent packages themselves are not listed: if @var{b} depends
11686 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
11687 @var{b} usually lacks substitutes as well. The result looks like this:
11690 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
11691 computing 8,983 package derivations for x86_64-linux...
11692 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
11693 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
11694 @value{SUBSTITUTE-URL}
11695 64.7% substitutes available (6,047 out of 9,343)
11697 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
11698 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
11699 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
11700 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
11704 What this example shows is that @code{kcoreaddons} and presumably the 58
11705 packages that depend on it have no substitutes at @code{ci.guix.info};
11706 likewise for @code{qgpgme} and the 46 packages that depend on it.
11708 If you are a Guix developer, or if you are taking care of this build farm,
11709 you'll probably want to have a closer look at these packages: they may simply
11712 @item --display-missing
11713 Display the list of store items for which substitutes are missing.
11716 @node Invoking guix processes
11717 @section Invoking @command{guix processes}
11719 The @command{guix processes} command can be useful to developers and system
11720 administrators, especially on multi-user machines and on build farms: it lists
11721 the current sessions (connections to the daemon), as well as information about
11722 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
11723 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
11724 listed.}. Here's an example of the information it returns:
11727 $ sudo guix processes
11730 ClientCommand: guix environment --ad-hoc python
11734 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
11738 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
11739 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
11740 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
11741 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
11742 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
11743 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
11744 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
11747 In this example we see that @command{guix-daemon} has three clients:
11748 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
11749 integration tool; their process identifier (PID) is given by the
11750 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
11751 @command{guix-daemon} sub-process of this particular session.
11753 The @code{LockHeld} fields show which store items are currently locked by this
11754 session, which corresponds to store items being built or substituted (the
11755 @code{LockHeld} field is not displayed when @command{guix processes} is not
11756 running as root). Last, by looking at the @code{ChildProcess} field, we
11757 understand that these three builds are being offloaded (@pxref{Daemon Offload
11760 The output is in Recutils format so we can use the handy @command{recsel}
11761 command to select sessions of interest (@pxref{Selection Expressions,,,
11762 recutils, GNU recutils manual}). As an example, the command shows the command
11763 line and PID of the client that triggered the build of a Perl package:
11766 $ sudo guix processes | \
11767 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
11769 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
11772 @node System Configuration
11773 @chapter System Configuration
11775 @cindex system configuration
11776 Guix System supports a consistent whole-system configuration
11777 mechanism. By that we mean that all aspects of the global system
11778 configuration---such as the available system services, timezone and
11779 locale settings, user accounts---are declared in a single place. Such
11780 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
11782 One of the advantages of putting all the system configuration under the
11783 control of Guix is that it supports transactional system upgrades, and
11784 makes it possible to roll back to a previous system instantiation,
11785 should something go wrong with the new one (@pxref{Features}). Another
11786 advantage is that it makes it easy to replicate the exact same configuration
11787 across different machines, or at different points in time, without
11788 having to resort to additional administration tools layered on top of
11789 the own tools of the system.
11790 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
11792 This section describes this mechanism. First we focus on the system
11793 administrator's viewpoint---explaining how the system is configured and
11794 instantiated. Then we show how this mechanism can be extended, for
11795 instance to support new system services.
11798 * Using the Configuration System:: Customizing your GNU system.
11799 * operating-system Reference:: Detail of operating-system declarations.
11800 * File Systems:: Configuring file system mounts.
11801 * Mapped Devices:: Block device extra processing.
11802 * User Accounts:: Specifying user accounts.
11803 * Keyboard Layout:: How the system interprets key strokes.
11804 * Locales:: Language and cultural convention settings.
11805 * Services:: Specifying system services.
11806 * Setuid Programs:: Programs running with root privileges.
11807 * X.509 Certificates:: Authenticating HTTPS servers.
11808 * Name Service Switch:: Configuring libc's name service switch.
11809 * Initial RAM Disk:: Linux-Libre bootstrapping.
11810 * Bootloader Configuration:: Configuring the boot loader.
11811 * Invoking guix system:: Instantiating a system configuration.
11812 * Invoking guix deploy:: Deploying a system configuration to a remote host.
11813 * Running Guix in a VM:: How to run Guix System in a virtual machine.
11814 * Defining Services:: Adding new service definitions.
11817 @node Using the Configuration System
11818 @section Using the Configuration System
11820 The operating system is configured by providing an
11821 @code{operating-system} declaration in a file that can then be passed to
11822 the @command{guix system} command (@pxref{Invoking guix system}). A
11823 simple setup, with the default system services, the default Linux-Libre
11824 kernel, initial RAM disk, and boot loader looks like this:
11826 @findex operating-system
11828 @include os-config-bare-bones.texi
11831 This example should be self-describing. Some of the fields defined
11832 above, such as @code{host-name} and @code{bootloader}, are mandatory.
11833 Others, such as @code{packages} and @code{services}, can be omitted, in
11834 which case they get a default value.
11836 Below we discuss the effect of some of the most important fields
11837 (@pxref{operating-system Reference}, for details about all the available
11838 fields), and how to @dfn{instantiate} the operating system using
11839 @command{guix system}.
11841 @unnumberedsubsec Bootloader
11843 @cindex legacy boot, on Intel machines
11844 @cindex BIOS boot, on Intel machines
11847 The @code{bootloader} field describes the method that will be used to boot
11848 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
11849 mode, as in the example above. However, more recent machines rely instead on
11850 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
11851 the @code{bootloader} field should contain something along these lines:
11854 (bootloader-configuration
11855 (bootloader grub-efi-bootloader)
11856 (target "/boot/efi"))
11859 @xref{Bootloader Configuration}, for more information on the available
11860 configuration options.
11862 @unnumberedsubsec Globally-Visible Packages
11864 @vindex %base-packages
11865 The @code{packages} field lists packages that will be globally visible
11866 on the system, for all user accounts---i.e., in every user's @env{PATH}
11867 environment variable---in addition to the per-user profiles
11868 (@pxref{Invoking guix package}). The @code{%base-packages} variable
11869 provides all the tools one would expect for basic user and administrator
11870 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
11871 the GNU Zile lightweight text editor, @command{find}, @command{grep},
11872 etc. The example above adds GNU@tie{}Screen to those,
11873 taken from the @code{(gnu packages screen)}
11874 module (@pxref{Package Modules}). The
11875 @code{(list package output)} syntax can be used to add a specific output
11879 (use-modules (gnu packages))
11880 (use-modules (gnu packages dns))
11884 (packages (cons (list bind "utils")
11888 @findex specification->package
11889 Referring to packages by variable name, like @code{bind} above, has
11890 the advantage of being unambiguous; it also allows typos and such to be
11891 diagnosed right away as ``unbound variables''. The downside is that one
11892 needs to know which module defines which package, and to augment the
11893 @code{use-package-modules} line accordingly. To avoid that, one can use
11894 the @code{specification->package} procedure of the @code{(gnu packages)}
11895 module, which returns the best package for a given name or name and
11899 (use-modules (gnu packages))
11903 (packages (append (map specification->package
11904 '("tcpdump" "htop" "gnupg@@2.0"))
11908 @unnumberedsubsec System Services
11911 @vindex %base-services
11912 The @code{services} field lists @dfn{system services} to be made
11913 available when the system starts (@pxref{Services}).
11914 The @code{operating-system} declaration above specifies that, in
11915 addition to the basic services, we want the OpenSSH secure shell
11916 daemon listening on port 2222 (@pxref{Networking Services,
11917 @code{openssh-service-type}}). Under the hood,
11918 @code{openssh-service-type} arranges so that @command{sshd} is started with the
11919 right command-line options, possibly with supporting configuration files
11920 generated as needed (@pxref{Defining Services}).
11922 @cindex customization, of services
11923 @findex modify-services
11924 Occasionally, instead of using the base services as is, you will want to
11925 customize them. To do this, use @code{modify-services} (@pxref{Service
11926 Reference, @code{modify-services}}) to modify the list.
11928 For example, suppose you want to modify @code{guix-daemon} and Mingetty
11929 (the console log-in) in the @code{%base-services} list (@pxref{Base
11930 Services, @code{%base-services}}). To do that, you can write the
11931 following in your operating system declaration:
11934 (define %my-services
11935 ;; My very own list of services.
11936 (modify-services %base-services
11937 (guix-service-type config =>
11938 (guix-configuration
11940 (use-substitutes? #f)
11941 (extra-options '("--gc-keep-derivations"))))
11942 (mingetty-service-type config =>
11943 (mingetty-configuration
11944 (inherit config)))))
11948 (services %my-services))
11951 This changes the configuration---i.e., the service parameters---of the
11952 @code{guix-service-type} instance, and that of all the
11953 @code{mingetty-service-type} instances in the @code{%base-services} list.
11954 Observe how this is accomplished: first, we arrange for the original
11955 configuration to be bound to the identifier @code{config} in the
11956 @var{body}, and then we write the @var{body} so that it evaluates to the
11957 desired configuration. In particular, notice how we use @code{inherit}
11958 to create a new configuration which has the same values as the old
11959 configuration, but with a few modifications.
11961 @cindex encrypted disk
11962 The configuration for a typical ``desktop'' usage, with an encrypted
11963 root partition, the X11 display
11964 server, GNOME and Xfce (users can choose which of these desktop
11965 environments to use at the log-in screen by pressing @kbd{F1}), network
11966 management, power management, and more, would look like this:
11969 @include os-config-desktop.texi
11972 A graphical system with a choice of lightweight window managers
11973 instead of full-blown desktop environments would look like this:
11976 @include os-config-lightweight-desktop.texi
11979 This example refers to the @file{/boot/efi} file system by its UUID,
11980 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
11981 as returned by the @command{blkid} command.
11983 @xref{Desktop Services}, for the exact list of services provided by
11984 @code{%desktop-services}. @xref{X.509 Certificates}, for background
11985 information about the @code{nss-certs} package that is used here.
11987 Again, @code{%desktop-services} is just a list of service objects. If
11988 you want to remove services from there, you can do so using the
11989 procedures for list filtering (@pxref{SRFI-1 Filtering and
11990 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
11991 following expression returns a list that contains all the services in
11992 @code{%desktop-services} minus the Avahi service:
11995 (remove (lambda (service)
11996 (eq? (service-kind service) avahi-service-type))
12000 @unnumberedsubsec Instantiating the System
12002 Assuming the @code{operating-system} declaration
12003 is stored in the @file{my-system-config.scm}
12004 file, the @command{guix system reconfigure my-system-config.scm} command
12005 instantiates that configuration, and makes it the default GRUB boot
12006 entry (@pxref{Invoking guix system}).
12008 The normal way to change the system configuration is by updating this
12009 file and re-running @command{guix system reconfigure}. One should never
12010 have to touch files in @file{/etc} or to run commands that modify the
12011 system state such as @command{useradd} or @command{grub-install}. In
12012 fact, you must avoid that since that would not only void your warranty
12013 but also prevent you from rolling back to previous versions of your
12014 system, should you ever need to.
12016 @cindex roll-back, of the operating system
12017 Speaking of roll-back, each time you run @command{guix system
12018 reconfigure}, a new @dfn{generation} of the system is created---without
12019 modifying or deleting previous generations. Old system generations get
12020 an entry in the bootloader boot menu, allowing you to boot them in case
12021 something went wrong with the latest generation. Reassuring, no? The
12022 @command{guix system list-generations} command lists the system
12023 generations available on disk. It is also possible to roll back the
12024 system via the commands @command{guix system roll-back} and
12025 @command{guix system switch-generation}.
12027 Although the @command{guix system reconfigure} command will not modify
12028 previous generations, you must take care when the current generation is not
12029 the latest (e.g., after invoking @command{guix system roll-back}), since
12030 the operation might overwrite a later generation (@pxref{Invoking guix
12033 @unnumberedsubsec The Programming Interface
12035 At the Scheme level, the bulk of an @code{operating-system} declaration
12036 is instantiated with the following monadic procedure (@pxref{The Store
12039 @deffn {Monadic Procedure} operating-system-derivation os
12040 Return a derivation that builds @var{os}, an @code{operating-system}
12041 object (@pxref{Derivations}).
12043 The output of the derivation is a single directory that refers to all
12044 the packages, configuration files, and other supporting files needed to
12045 instantiate @var{os}.
12048 This procedure is provided by the @code{(gnu system)} module. Along
12049 with @code{(gnu services)} (@pxref{Services}), this module contains the
12050 guts of Guix System. Make sure to visit it!
12053 @node operating-system Reference
12054 @section @code{operating-system} Reference
12056 This section summarizes all the options available in
12057 @code{operating-system} declarations (@pxref{Using the Configuration
12060 @deftp {Data Type} operating-system
12061 This is the data type representing an operating system configuration.
12062 By that, we mean all the global system configuration, not per-user
12063 configuration (@pxref{Using the Configuration System}).
12066 @item @code{kernel} (default: @code{linux-libre})
12067 The package object of the operating system kernel to
12068 use@footnote{Currently only the Linux-libre kernel is fully supported.
12069 Using GNU@tie{}mach with the GNU@tie{}Hurd is experimental and only
12070 available when building a virtual machine disk image.}.
12073 @item @code{hurd} (default: @code{#f})
12074 The package object of the hurd to be started by the kernel. When this
12075 field is set, produce a GNU/Hurd operating system. In that case,
12076 @code{kernel} must also be set to the @code{gnumach} package---the
12077 microkernel the Hurd runs on.
12080 This feature is experimental and only supported for disk images.
12083 @item @code{kernel-loadable-modules} (default: '())
12084 A list of objects (usually packages) to collect loadable kernel modules
12085 from--e.g. @code{(list ddcci-driver-linux)}.
12087 @item @code{kernel-arguments} (default: @code{%default-kernel-arguments})
12088 List of strings or gexps representing additional arguments to pass on
12089 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
12091 @item @code{bootloader}
12092 The system bootloader configuration object. @xref{Bootloader Configuration}.
12095 This is the label (a string) as it appears in the bootloader's menu entry.
12096 The default label includes the kernel name and version.
12098 @item @code{keyboard-layout} (default: @code{#f})
12099 This field specifies the keyboard layout to use in the console. It can be
12100 either @code{#f}, in which case the default keyboard layout is used (usually
12101 US English), or a @code{<keyboard-layout>} record.
12103 This keyboard layout is in effect as soon as the kernel has booted. For
12104 instance, it is the keyboard layout in effect when you type a passphrase if
12105 your root file system is on a @code{luks-device-mapping} mapped device
12106 (@pxref{Mapped Devices}).
12109 This does @emph{not} specify the keyboard layout used by the bootloader, nor
12110 that used by the graphical display server. @xref{Bootloader Configuration},
12111 for information on how to specify the bootloader's keyboard layout. @xref{X
12112 Window}, for information on how to specify the keyboard layout used by the X
12116 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
12118 @cindex initial RAM disk
12119 The list of Linux kernel modules that need to be available in the
12120 initial RAM disk. @xref{Initial RAM Disk}.
12122 @item @code{initrd} (default: @code{base-initrd})
12123 A procedure that returns an initial RAM disk for the Linux
12124 kernel. This field is provided to support low-level customization and
12125 should rarely be needed for casual use. @xref{Initial RAM Disk}.
12127 @item @code{firmware} (default: @code{%base-firmware})
12129 List of firmware packages loadable by the operating system kernel.
12131 The default includes firmware needed for Atheros- and Broadcom-based
12132 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
12133 respectively). @xref{Hardware Considerations}, for more info on
12134 supported hardware.
12136 @item @code{host-name}
12139 @item @code{hosts-file}
12141 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
12142 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
12143 Reference Manual}). The default is a file with entries for
12144 @code{localhost} and @var{host-name}.
12146 @item @code{mapped-devices} (default: @code{'()})
12147 A list of mapped devices. @xref{Mapped Devices}.
12149 @item @code{file-systems}
12150 A list of file systems. @xref{File Systems}.
12152 @item @code{swap-devices} (default: @code{'()})
12153 @cindex swap devices
12154 A list of strings identifying devices or files to be used for ``swap
12155 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
12156 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
12157 It is possible to specify a swap file in a file system on a mapped
12158 device, provided that the necessary device mapping and file system are
12159 also specified. @xref{Mapped Devices} and @ref{File Systems}.
12161 @item @code{users} (default: @code{%base-user-accounts})
12162 @itemx @code{groups} (default: @code{%base-groups})
12163 List of user accounts and groups. @xref{User Accounts}.
12165 If the @code{users} list lacks a user account with UID@tie{}0, a
12166 ``root'' account with UID@tie{}0 is automatically added.
12168 @item @code{skeletons} (default: @code{(default-skeletons)})
12169 A list of target file name/file-like object tuples (@pxref{G-Expressions,
12170 file-like objects}). These are the skeleton files that will be added to
12171 the home directory of newly-created user accounts.
12173 For instance, a valid value may look like this:
12176 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
12177 (".guile" ,(plain-file "guile"
12178 "(use-modules (ice-9 readline))
12179 (activate-readline)")))
12182 @item @code{issue} (default: @code{%default-issue})
12183 A string denoting the contents of the @file{/etc/issue} file, which is
12184 displayed when users log in on a text console.
12186 @item @code{packages} (default: @code{%base-packages})
12187 A list of packages to be installed in the global profile, which is accessible
12188 at @file{/run/current-system/profile}. Each element is either a package
12189 variable or a package/output tuple. Here's a simple example of both:
12192 (cons* git ; the default "out" output
12193 (list git "send-email") ; another output of git
12194 %base-packages) ; the default set
12197 The default set includes core utilities and it is good practice to
12198 install non-core utilities in user profiles (@pxref{Invoking guix
12201 @item @code{timezone}
12202 A timezone identifying string---e.g., @code{"Europe/Paris"}.
12204 You can run the @command{tzselect} command to find out which timezone
12205 string corresponds to your region. Choosing an invalid timezone name
12206 causes @command{guix system} to fail.
12208 @item @code{locale} (default: @code{"en_US.utf8"})
12209 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
12210 Library Reference Manual}). @xref{Locales}, for more information.
12212 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
12213 The list of locale definitions to be compiled and that may be used at
12214 run time. @xref{Locales}.
12216 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
12217 The list of GNU@tie{}libc packages whose locale data and tools are used
12218 to build the locale definitions. @xref{Locales}, for compatibility
12219 considerations that justify this option.
12221 @item @code{name-service-switch} (default: @code{%default-nss})
12222 Configuration of the libc name service switch (NSS)---a
12223 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
12226 @item @code{services} (default: @code{%base-services})
12227 A list of service objects denoting system services. @xref{Services}.
12229 @cindex essential services
12230 @item @code{essential-services} (default: ...)
12231 The list of ``essential services''---i.e., things like instances of
12232 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
12233 Reference}), which are derived from the operating system definition itself.
12234 As a user you should @emph{never} need to touch this field.
12236 @item @code{pam-services} (default: @code{(base-pam-services)})
12238 @cindex pluggable authentication modules
12239 Linux @dfn{pluggable authentication module} (PAM) services.
12240 @c FIXME: Add xref to PAM services section.
12242 @item @code{setuid-programs} (default: @code{%setuid-programs})
12243 List of string-valued G-expressions denoting setuid programs.
12244 @xref{Setuid Programs}.
12246 @item @code{sudoers-file} (default: @code{%sudoers-specification})
12247 @cindex sudoers file
12248 The contents of the @file{/etc/sudoers} file as a file-like object
12249 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
12251 This file specifies which users can use the @command{sudo} command, what
12252 they are allowed to do, and what privileges they may gain. The default
12253 is that only @code{root} and members of the @code{wheel} group may use
12258 @deffn {Scheme Syntax} this-operating-system
12259 When used in the @emph{lexical scope} of an operating system field definition,
12260 this identifier resolves to the operating system being defined.
12262 The example below shows how to refer to the operating system being defined in
12263 the definition of the @code{label} field:
12266 (use-modules (gnu) (guix))
12270 (label (package-full-name
12271 (operating-system-kernel this-operating-system))))
12274 It is an error to refer to @code{this-operating-system} outside an operating
12281 @section File Systems
12283 The list of file systems to be mounted is specified in the
12284 @code{file-systems} field of the operating system declaration
12285 (@pxref{Using the Configuration System}). Each file system is declared
12286 using the @code{file-system} form, like this:
12290 (mount-point "/home")
12291 (device "/dev/sda3")
12295 As usual, some of the fields are mandatory---those shown in the example
12296 above---while others can be omitted. These are described below.
12298 @deftp {Data Type} file-system
12299 Objects of this type represent file systems to be mounted. They
12300 contain the following members:
12304 This is a string specifying the type of the file system---e.g.,
12307 @item @code{mount-point}
12308 This designates the place where the file system is to be mounted.
12310 @item @code{device}
12311 This names the ``source'' of the file system. It can be one of three
12312 things: a file system label, a file system UUID, or the name of a
12313 @file{/dev} node. Labels and UUIDs offer a way to refer to file
12314 systems without having to hard-code their actual device
12315 name@footnote{Note that, while it is tempting to use
12316 @file{/dev/disk/by-uuid} and similar device names to achieve the same
12317 result, this is not recommended: These special device nodes are created
12318 by the udev daemon and may be unavailable at the time the device is
12321 @findex file-system-label
12322 File system labels are created using the @code{file-system-label}
12323 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
12324 plain strings. Here's an example of a file system referred to by its
12325 label, as shown by the @command{e2label} command:
12329 (mount-point "/home")
12331 (device (file-system-label "my-home")))
12335 UUIDs are converted from their string representation (as shown by the
12336 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
12337 @code{uuid} form expects 16-byte UUIDs as defined in
12338 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
12339 form of UUID used by the ext2 family of file systems and others, but it
12340 is different from ``UUIDs'' found in FAT file systems, for instance.},
12345 (mount-point "/home")
12347 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
12350 When the source of a file system is a mapped device (@pxref{Mapped
12351 Devices}), its @code{device} field @emph{must} refer to the mapped
12352 device name---e.g., @file{"/dev/mapper/root-partition"}.
12353 This is required so that
12354 the system knows that mounting the file system depends on having the
12355 corresponding device mapping established.
12357 @item @code{flags} (default: @code{'()})
12358 This is a list of symbols denoting mount flags. Recognized flags
12359 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
12360 access to special files), @code{no-suid} (ignore setuid and setgid
12361 bits), @code{no-atime} (do not update file access times),
12362 @code{strict-atime} (update file access time), @code{lazy-time} (only
12363 update time on the in-memory version of the file inode), and
12364 @code{no-exec} (disallow program execution).
12365 @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
12366 Manual}, for more information on these flags.
12368 @item @code{options} (default: @code{#f})
12369 This is either @code{#f}, or a string denoting mount options passed to
12370 the file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C
12371 Library Reference Manual}, for details and run @command{man 8 mount} for
12372 options for various file systems. Note that the
12373 @code{file-system-options->alist} and @code{alist->file-system-options}
12374 procedures from @code{(gnu system file-systems)} can be used to convert
12375 file system options given as an association list to the string
12376 representation, and vice-versa.
12378 @item @code{mount?} (default: @code{#t})
12379 This value indicates whether to automatically mount the file system when
12380 the system is brought up. When set to @code{#f}, the file system gets
12381 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
12382 is not automatically mounted.
12384 @item @code{needed-for-boot?} (default: @code{#f})
12385 This Boolean value indicates whether the file system is needed when
12386 booting. If that is true, then the file system is mounted when the
12387 initial RAM disk (initrd) is loaded. This is always the case, for
12388 instance, for the root file system.
12390 @item @code{check?} (default: @code{#t})
12391 This Boolean indicates whether the file system needs to be checked for
12392 errors before being mounted.
12394 @item @code{create-mount-point?} (default: @code{#f})
12395 When true, the mount point is created if it does not exist yet.
12397 @item @code{mount-may-fail?} (default: @code{#f})
12398 When true, this indicates that mounting this file system can fail but
12399 that should not be considered an error. This is useful in unusual
12400 cases; an example of this is @code{efivarfs}, a file system that can
12401 only be mounted on EFI/UEFI systems.
12403 @item @code{dependencies} (default: @code{'()})
12404 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
12405 representing file systems that must be mounted or mapped devices that
12406 must be opened before (and unmounted or closed after) this one.
12408 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
12409 a dependency of @file{/sys/fs/cgroup/cpu} and
12410 @file{/sys/fs/cgroup/memory}.
12412 Another example is a file system that depends on a mapped device, for
12413 example for an encrypted partition (@pxref{Mapped Devices}).
12417 @deffn {Scheme Procedure} file-system-label @var{str}
12418 This procedure returns an opaque file system label from @var{str}, a
12422 (file-system-label "home")
12423 @result{} #<file-system-label "home">
12426 File system labels are used to refer to file systems by label rather
12427 than by device name. See above for examples.
12430 The @code{(gnu system file-systems)} exports the following useful
12433 @defvr {Scheme Variable} %base-file-systems
12434 These are essential file systems that are required on normal systems,
12435 such as @code{%pseudo-terminal-file-system} and @code{%immutable-store} (see
12436 below). Operating system declarations should always contain at least
12440 @defvr {Scheme Variable} %pseudo-terminal-file-system
12441 This is the file system to be mounted as @file{/dev/pts}. It supports
12442 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
12443 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
12444 Manual}). Pseudo-terminals are used by terminal emulators such as
12448 @defvr {Scheme Variable} %shared-memory-file-system
12449 This file system is mounted as @file{/dev/shm} and is used to support
12450 memory sharing across processes (@pxref{Memory-mapped I/O,
12451 @code{shm_open},, libc, The GNU C Library Reference Manual}).
12454 @defvr {Scheme Variable} %immutable-store
12455 This file system performs a read-only ``bind mount'' of
12456 @file{/gnu/store}, making it read-only for all the users including
12457 @code{root}. This prevents against accidental modification by software
12458 running as @code{root} or by system administrators.
12460 The daemon itself is still able to write to the store: it remounts it
12461 read-write in its own ``name space.''
12464 @defvr {Scheme Variable} %binary-format-file-system
12465 The @code{binfmt_misc} file system, which allows handling of arbitrary
12466 executable file types to be delegated to user space. This requires the
12467 @code{binfmt.ko} kernel module to be loaded.
12470 @defvr {Scheme Variable} %fuse-control-file-system
12471 The @code{fusectl} file system, which allows unprivileged users to mount
12472 and unmount user-space FUSE file systems. This requires the
12473 @code{fuse.ko} kernel module to be loaded.
12476 The @code{(gnu system uuid)} module provides tools to deal with file
12477 system ``unique identifiers'' (UUIDs).
12479 @deffn {Scheme Procedure} uuid @var{str} [@var{type}]
12480 Return an opaque UUID (unique identifier) object of the given @var{type}
12481 (a symbol) by parsing @var{str} (a string):
12484 (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")
12485 @result{} #<<uuid> type: dce bv: @dots{}>
12487 (uuid "1234-ABCD" 'fat)
12488 @result{} #<<uuid> type: fat bv: @dots{}>
12491 @var{type} may be one of @code{dce}, @code{iso9660}, @code{fat},
12492 @code{ntfs}, or one of the commonly found synonyms for these.
12494 UUIDs are another way to unambiguously refer to file systems in
12495 operating system configuration. See the examples above.
12499 @node Btrfs file system
12500 @subsection Btrfs file system
12502 The Btrfs has special features, such as subvolumes, that merit being
12503 explained in more details. The following section attempts to cover
12504 basic as well as complex uses of a Btrfs file system with the Guix
12507 In its simplest usage, a Btrfs file system can be described, for
12512 (mount-point "/home")
12514 (device (file-system-label "my-home")))
12517 The example below is more complex, as it makes use of a Btrfs
12518 subvolume, named @code{rootfs}. The parent Btrfs file system is labeled
12519 @code{my-btrfs-pool}, and is located on an encrypted device (hence the
12520 dependency on @code{mapped-devices}):
12524 (device (file-system-label "my-btrfs-pool"))
12527 (options "subvol=rootfs")
12528 (dependencies mapped-devices))
12531 Some bootloaders, for example GRUB, only mount a Btrfs partition at its
12532 top level during the early boot, and rely on their configuration to
12533 refer to the correct subvolume path within that top level. The
12534 bootloaders operating in this way typically produce their configuration
12535 on a running system where the Btrfs partitions are already mounted and
12536 where the subvolume information is readily available. As an example,
12537 @command{grub-mkconfig}, the configuration generator command shipped
12538 with GRUB, reads @file{/proc/self/mountinfo} to determine the top-level
12539 path of a subvolume.
12541 The Guix System produces a bootloader configuration using the operating
12542 system configuration as its sole input; it is therefore necessary to
12543 extract the subvolume name on which @file{/gnu/store} lives (if any)
12544 from that operating system configuration. To better illustrate,
12545 consider a subvolume named 'rootfs' which contains the root file system
12546 data. In such situation, the GRUB bootloader would only see the top
12547 level of the root Btrfs partition, e.g.:
12551 ├── rootfs (subvolume directory)
12552 ├── gnu (normal directory)
12553 ├── store (normal directory)
12557 Thus, the subvolume name must be prepended to the @file{/gnu/store} path
12558 of the kernel, initrd binaries and any other files referred to in the
12559 GRUB configuration that must be found during the early boot.
12561 The next example shows a nested hierarchy of subvolumes and
12566 ├── rootfs (subvolume)
12567 ├── gnu (normal directory)
12568 ├── store (subvolume)
12572 This scenario would work without mounting the 'store' subvolume.
12573 Mounting 'rootfs' is sufficient, since the subvolume name matches its
12574 intended mount point in the file system hierarchy. Alternatively, the
12575 'store' subvolume could be referred to by setting the @code{subvol}
12576 option to either @code{/rootfs/gnu/store} or @code{rootfs/gnu/store}.
12578 Finally, a more contrived example of nested subvolumes:
12582 ├── root-snapshots (subvolume)
12583 ├── root-current (subvolume)
12584 ├── guix-store (subvolume)
12588 Here, the 'guix-store' subvolume doesn't match its intended mount point,
12589 so it is necessary to mount it. The subvolume must be fully specified,
12590 by passing its file name to the @code{subvol} option. To illustrate,
12591 the 'guix-store' subvolume could be mounted on @file{/gnu/store} by using
12592 a file system declaration such as:
12596 (device (file-system-label "btrfs-pool-1"))
12597 (mount-point "/gnu/store")
12599 (options "subvol=root-snapshots/root-current/guix-store,\
12600 compress-force=zstd,space_cache=v2"))
12603 @node Mapped Devices
12604 @section Mapped Devices
12606 @cindex device mapping
12607 @cindex mapped devices
12608 The Linux kernel has a notion of @dfn{device mapping}: a block device,
12609 such as a hard disk partition, can be @dfn{mapped} into another device,
12610 usually in @code{/dev/mapper/},
12611 with additional processing over the data that flows through
12612 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
12613 concept of a ``mapped device'' and that of a file system: both boil down
12614 to @emph{translating} input/output operations made on a file to
12615 operations on its backing store. Thus, the Hurd implements mapped
12616 devices, like file systems, using the generic @dfn{translator} mechanism
12617 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
12618 typical example is encryption device mapping: all writes to the mapped
12619 device are encrypted, and all reads are deciphered, transparently.
12620 Guix extends this notion by considering any device or set of devices that
12621 are @dfn{transformed} in some way to create a new device; for instance,
12622 RAID devices are obtained by @dfn{assembling} several other devices, such
12623 as hard disks or partitions, into a new one that behaves as one partition.
12624 Other examples, not yet implemented, are LVM logical volumes.
12626 Mapped devices are declared using the @code{mapped-device} form,
12627 defined as follows; for examples, see below.
12629 @deftp {Data Type} mapped-device
12630 Objects of this type represent device mappings that will be made when
12631 the system boots up.
12635 This is either a string specifying the name of the block device to be mapped,
12636 such as @code{"/dev/sda3"}, or a list of such strings when several devices
12637 need to be assembled for creating a new one.
12640 This string specifies the name of the resulting mapped device. For
12641 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
12642 specifying @code{"my-partition"} leads to the creation of
12643 the @code{"/dev/mapper/my-partition"} device.
12644 For RAID devices of type @code{raid-device-mapping}, the full device name
12645 such as @code{"/dev/md0"} needs to be given.
12648 This must be a @code{mapped-device-kind} object, which specifies how
12649 @var{source} is mapped to @var{target}.
12653 @defvr {Scheme Variable} luks-device-mapping
12654 This defines LUKS block device encryption using the @command{cryptsetup}
12655 command from the package with the same name. It relies on the
12656 @code{dm-crypt} Linux kernel module.
12659 @defvr {Scheme Variable} raid-device-mapping
12660 This defines a RAID device, which is assembled using the @code{mdadm}
12661 command from the package with the same name. It requires a Linux kernel
12662 module for the appropriate RAID level to be loaded, such as @code{raid456}
12663 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
12666 @cindex disk encryption
12668 The following example specifies a mapping from @file{/dev/sda3} to
12669 @file{/dev/mapper/home} using LUKS---the
12670 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
12671 standard mechanism for disk encryption.
12672 The @file{/dev/mapper/home}
12673 device can then be used as the @code{device} of a @code{file-system}
12674 declaration (@pxref{File Systems}).
12678 (source "/dev/sda3")
12680 (type luks-device-mapping))
12683 Alternatively, to become independent of device numbering, one may obtain
12684 the LUKS UUID (@dfn{unique identifier}) of the source device by a
12688 cryptsetup luksUUID /dev/sda3
12691 and use it as follows:
12695 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
12697 (type luks-device-mapping))
12700 @cindex swap encryption
12701 It is also desirable to encrypt swap space, since swap space may contain
12702 sensitive data. One way to accomplish that is to use a swap file in a
12703 file system on a device mapped via LUKS encryption. In this way, the
12704 swap file is encrypted because the entire device is encrypted.
12705 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
12707 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
12708 may be declared as follows:
12712 (source (list "/dev/sda1" "/dev/sdb1"))
12713 (target "/dev/md0")
12714 (type raid-device-mapping))
12717 The @file{/dev/md0} device can then be used as the @code{device} of a
12718 @code{file-system} declaration (@pxref{File Systems}).
12719 Note that the RAID level need not be given; it is chosen during the
12720 initial creation and formatting of the RAID device and is determined
12721 automatically later.
12724 @node User Accounts
12725 @section User Accounts
12729 @cindex user accounts
12730 User accounts and groups are entirely managed through the
12731 @code{operating-system} declaration. They are specified with the
12732 @code{user-account} and @code{user-group} forms:
12738 (supplementary-groups '("wheel" ;allow use of sudo, etc.
12739 "audio" ;sound card
12740 "video" ;video devices such as webcams
12741 "cdrom")) ;the good ol' CD-ROM
12742 (comment "Bob's sister")
12743 (home-directory "/home/alice"))
12746 When booting or upon completion of @command{guix system reconfigure},
12747 the system ensures that only the user accounts and groups specified in
12748 the @code{operating-system} declaration exist, and with the specified
12749 properties. Thus, account or group creations or modifications made by
12750 directly invoking commands such as @command{useradd} are lost upon
12751 reconfiguration or reboot. This ensures that the system remains exactly
12754 @deftp {Data Type} user-account
12755 Objects of this type represent user accounts. The following members may
12760 The name of the user account.
12764 This is the name (a string) or identifier (a number) of the user group
12765 this account belongs to.
12767 @item @code{supplementary-groups} (default: @code{'()})
12768 Optionally, this can be defined as a list of group names that this
12769 account belongs to.
12771 @item @code{uid} (default: @code{#f})
12772 This is the user ID for this account (a number), or @code{#f}. In the
12773 latter case, a number is automatically chosen by the system when the
12774 account is created.
12776 @item @code{comment} (default: @code{""})
12777 A comment about the account, such as the account owner's full name.
12779 @item @code{home-directory}
12780 This is the name of the home directory for the account.
12782 @item @code{create-home-directory?} (default: @code{#t})
12783 Indicates whether the home directory of this account should be created
12784 if it does not exist yet.
12786 @item @code{shell} (default: Bash)
12787 This is a G-expression denoting the file name of a program to be used as
12788 the shell (@pxref{G-Expressions}).
12790 @item @code{system?} (default: @code{#f})
12791 This Boolean value indicates whether the account is a ``system''
12792 account. System accounts are sometimes treated specially; for instance,
12793 graphical login managers do not list them.
12795 @anchor{user-account-password}
12796 @cindex password, for user accounts
12797 @item @code{password} (default: @code{#f})
12798 You would normally leave this field to @code{#f}, initialize user
12799 passwords as @code{root} with the @command{passwd} command, and then let
12800 users change it with @command{passwd}. Passwords set with
12801 @command{passwd} are of course preserved across reboot and
12804 If you @emph{do} want to set an initial password for an account, then
12805 this field must contain the encrypted password, as a string. You can use the
12806 @code{crypt} procedure for this purpose:
12813 ;; Specify a SHA-512-hashed initial password.
12814 (password (crypt "InitialPassword!" "$6$abc")))
12818 The hash of this initial password will be available in a file in
12819 @file{/gnu/store}, readable by all the users, so this method must be used with
12823 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
12824 more information on password encryption, and @ref{Encryption,,, guile, GNU
12825 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
12831 User group declarations are even simpler:
12834 (user-group (name "students"))
12837 @deftp {Data Type} user-group
12838 This type is for, well, user groups. There are just a few fields:
12842 The name of the group.
12844 @item @code{id} (default: @code{#f})
12845 The group identifier (a number). If @code{#f}, a new number is
12846 automatically allocated when the group is created.
12848 @item @code{system?} (default: @code{#f})
12849 This Boolean value indicates whether the group is a ``system'' group.
12850 System groups have low numerical IDs.
12852 @item @code{password} (default: @code{#f})
12853 What, user groups can have a password? Well, apparently yes. Unless
12854 @code{#f}, this field specifies the password of the group.
12859 For convenience, a variable lists all the basic user groups one may
12862 @defvr {Scheme Variable} %base-groups
12863 This is the list of basic user groups that users and/or packages expect
12864 to be present on the system. This includes groups such as ``root'',
12865 ``wheel'', and ``users'', as well as groups used to control access to
12866 specific devices such as ``audio'', ``disk'', and ``cdrom''.
12869 @defvr {Scheme Variable} %base-user-accounts
12870 This is the list of basic system accounts that programs may expect to
12871 find on a GNU/Linux system, such as the ``nobody'' account.
12873 Note that the ``root'' account is not included here. It is a
12874 special-case and is automatically added whether or not it is specified.
12877 @node Keyboard Layout
12878 @section Keyboard Layout
12880 @cindex keyboard layout
12882 To specify what each key of your keyboard does, you need to tell the operating
12883 system what @dfn{keyboard layout} you want to use. The default, when nothing
12884 is specified, is the US English QWERTY layout for 105-key PC keyboards.
12885 However, German speakers will usually prefer the German QWERTZ layout, French
12886 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
12887 or bépo, and they might even want to further customize the effect of some of
12888 the keys. This section explains how to get that done.
12890 @cindex keyboard layout, definition
12891 There are three components that will want to know about your keyboard layout:
12895 The @emph{bootloader} may want to know what keyboard layout you want to use
12896 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
12897 you want, for instance, to make sure that you can type the passphrase of your
12898 encrypted root partition using the right layout.
12901 The @emph{operating system kernel}, Linux, will need that so that the console
12902 is properly configured (@pxref{operating-system Reference,
12903 @code{keyboard-layout}}).
12906 The @emph{graphical display server}, usually Xorg, also has its own idea of
12907 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
12910 Guix allows you to configure all three separately but, fortunately, it allows
12911 you to share the same keyboard layout for all three components.
12913 @cindex XKB, keyboard layouts
12914 Keyboard layouts are represented by records created by the
12915 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
12916 the X Keyboard extension (XKB), each layout has four attributes: a name (often
12917 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
12918 optional variant name, an optional keyboard model name, and a possibly empty
12919 list of additional options. In most cases the layout name is all you care
12920 about. Here are a few example:
12923 ;; The German QWERTZ layout. Here we assume a standard
12924 ;; "pc105" keyboard model.
12925 (keyboard-layout "de")
12927 ;; The bépo variant of the French layout.
12928 (keyboard-layout "fr" "bepo")
12930 ;; The Catalan layout.
12931 (keyboard-layout "es" "cat")
12933 ;; Arabic layout with "Alt-Shift" to switch to US layout.
12934 (keyboard-layout "ar,us" #:options '("grp:alt_shift_toggle"))
12936 ;; The Latin American Spanish layout. In addition, the
12937 ;; "Caps Lock" key is used as an additional "Ctrl" key,
12938 ;; and the "Menu" key is used as a "Compose" key to enter
12939 ;; accented letters.
12940 (keyboard-layout "latam"
12941 #:options '("ctrl:nocaps" "compose:menu"))
12943 ;; The Russian layout for a ThinkPad keyboard.
12944 (keyboard-layout "ru" #:model "thinkpad")
12946 ;; The "US international" layout, which is the US layout plus
12947 ;; dead keys to enter accented characters. This is for an
12948 ;; Apple MacBook keyboard.
12949 (keyboard-layout "us" "intl" #:model "macbook78")
12952 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
12953 for a complete list of supported layouts, variants, and models.
12955 @cindex keyboard layout, configuration
12956 Let's say you want your system to use the Turkish keyboard layout throughout
12957 your system---bootloader, console, and Xorg. Here's what your system
12958 configuration would look like:
12960 @findex set-xorg-configuration
12962 ;; Using the Turkish layout for the bootloader, the console,
12967 (keyboard-layout (keyboard-layout "tr")) ;for the console
12968 (bootloader (bootloader-configuration
12969 (bootloader grub-efi-bootloader)
12970 (target "/boot/efi")
12971 (keyboard-layout keyboard-layout))) ;for GRUB
12972 (services (cons (set-xorg-configuration
12973 (xorg-configuration ;for Xorg
12974 (keyboard-layout keyboard-layout)))
12975 %desktop-services)))
12978 In the example above, for GRUB and for Xorg, we just refer to the
12979 @code{keyboard-layout} field defined above, but we could just as well refer to
12980 a different layout. The @code{set-xorg-configuration} procedure communicates
12981 the desired Xorg configuration to the graphical log-in manager, by default
12984 We've discussed how to specify the @emph{default} keyboard layout of your
12985 system when it starts, but you can also adjust it at run time:
12989 If you're using GNOME, its settings panel has a ``Region & Language'' entry
12990 where you can select one or more keyboard layouts.
12993 Under Xorg, the @command{setxkbmap} command (from the same-named package)
12994 allows you to change the current layout. For example, this is how you would
12995 change the layout to US Dvorak:
12998 setxkbmap us dvorak
13002 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
13003 console. However, note that @code{loadkeys} does @emph{not} use the XKB
13004 keyboard layout categorization described above. The command below loads the
13005 French bépo layout:
13016 A @dfn{locale} defines cultural conventions for a particular language
13017 and region of the world (@pxref{Locales,,, libc, The GNU C Library
13018 Reference Manual}). Each locale has a name that typically has the form
13019 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
13020 @code{fr_LU.utf8} designates the locale for the French language, with
13021 cultural conventions from Luxembourg, and using the UTF-8 encoding.
13023 @cindex locale definition
13024 Usually, you will want to specify the default locale for the machine
13025 using the @code{locale} field of the @code{operating-system} declaration
13026 (@pxref{operating-system Reference, @code{locale}}).
13028 The selected locale is automatically added to the @dfn{locale
13029 definitions} known to the system if needed, with its codeset inferred
13030 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
13031 @code{UTF-8} codeset. Additional locale definitions can be specified in
13032 the @code{locale-definitions} slot of @code{operating-system}---this is
13033 useful, for instance, if the codeset could not be inferred from the
13034 locale name. The default set of locale definitions includes some widely
13035 used locales, but not all the available locales, in order to save space.
13037 For instance, to add the North Frisian locale for Germany, the value of
13041 (cons (locale-definition
13042 (name "fy_DE.utf8") (source "fy_DE"))
13043 %default-locale-definitions)
13046 Likewise, to save space, one might want @code{locale-definitions} to
13047 list only the locales that are actually used, as in:
13050 (list (locale-definition
13051 (name "ja_JP.eucjp") (source "ja_JP")
13052 (charset "EUC-JP")))
13056 The compiled locale definitions are available at
13057 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
13058 version, which is the default location where the GNU@tie{}libc provided
13059 by Guix looks for locale data. This can be overridden using the
13060 @env{LOCPATH} environment variable (@pxref{locales-and-locpath,
13061 @env{LOCPATH} and locale packages}).
13063 The @code{locale-definition} form is provided by the @code{(gnu system
13064 locale)} module. Details are given below.
13066 @deftp {Data Type} locale-definition
13067 This is the data type of a locale definition.
13072 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
13073 Reference Manual}, for more information on locale names.
13075 @item @code{source}
13076 The name of the source for that locale. This is typically the
13077 @code{@var{language}_@var{territory}} part of the locale name.
13079 @item @code{charset} (default: @code{"UTF-8"})
13080 The ``character set'' or ``code set'' for that locale,
13081 @uref{https://www.iana.org/assignments/character-sets, as defined by
13087 @defvr {Scheme Variable} %default-locale-definitions
13088 A list of commonly used UTF-8 locales, used as the default
13089 value of the @code{locale-definitions} field of @code{operating-system}
13092 @cindex locale name
13093 @cindex normalized codeset in locale names
13094 These locale definitions use the @dfn{normalized codeset} for the part
13095 that follows the dot in the name (@pxref{Using gettextized software,
13096 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
13097 instance it has @code{uk_UA.utf8} but @emph{not}, say,
13098 @code{uk_UA.UTF-8}.
13101 @subsection Locale Data Compatibility Considerations
13103 @cindex incompatibility, of locale data
13104 @code{operating-system} declarations provide a @code{locale-libcs} field
13105 to specify the GNU@tie{}libc packages that are used to compile locale
13106 declarations (@pxref{operating-system Reference}). ``Why would I
13107 care?'', you may ask. Well, it turns out that the binary format of
13108 locale data is occasionally incompatible from one libc version to
13111 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
13112 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
13113 For instance, a program linked against libc version 2.21 is unable to
13114 read locale data produced with libc 2.22; worse, that program
13115 @emph{aborts} instead of simply ignoring the incompatible locale
13116 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
13117 the incompatible locale data, which is already an improvement.}.
13118 Similarly, a program linked against libc 2.22 can read most, but not
13119 all, of the locale data from libc 2.21 (specifically, @env{LC_COLLATE}
13120 data is incompatible); thus calls to @code{setlocale} may fail, but
13121 programs will not abort.
13123 The ``problem'' with Guix is that users have a lot of freedom: They can
13124 choose whether and when to upgrade software in their profiles, and might
13125 be using a libc version different from the one the system administrator
13126 used to build the system-wide locale data.
13128 Fortunately, unprivileged users can also install their own locale data
13129 and define @env{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
13130 @env{GUIX_LOCPATH} and locale packages}).
13132 Still, it is best if the system-wide locale data at
13133 @file{/run/current-system/locale} is built for all the libc versions
13134 actually in use on the system, so that all the programs can access
13135 it---this is especially crucial on a multi-user system. To do that, the
13136 administrator can specify several libc packages in the
13137 @code{locale-libcs} field of @code{operating-system}:
13140 (use-package-modules base)
13144 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
13147 This example would lead to a system containing locale definitions for
13148 both libc 2.21 and the current version of libc in
13149 @file{/run/current-system/locale}.
13155 @cindex system services
13156 An important part of preparing an @code{operating-system} declaration is
13157 listing @dfn{system services} and their configuration (@pxref{Using the
13158 Configuration System}). System services are typically daemons launched
13159 when the system boots, or other actions needed at that time---e.g.,
13160 configuring network access.
13162 Guix has a broad definition of ``service'' (@pxref{Service
13163 Composition}), but many services are managed by the GNU@tie{}Shepherd
13164 (@pxref{Shepherd Services}). On a running system, the @command{herd}
13165 command allows you to list the available services, show their status,
13166 start and stop them, or do other specific operations (@pxref{Jump
13167 Start,,, shepherd, The GNU Shepherd Manual}). For example:
13173 The above command, run as @code{root}, lists the currently defined
13174 services. The @command{herd doc} command shows a synopsis of the given
13175 service and its associated actions:
13179 Run libc's name service cache daemon (nscd).
13181 # herd doc nscd action invalidate
13182 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
13185 The @command{start}, @command{stop}, and @command{restart} sub-commands
13186 have the effect you would expect. For instance, the commands below stop
13187 the nscd service and restart the Xorg display server:
13191 Service nscd has been stopped.
13192 # herd restart xorg-server
13193 Service xorg-server has been stopped.
13194 Service xorg-server has been started.
13197 The following sections document the available services, starting with
13198 the core services, that may be used in an @code{operating-system}
13202 * Base Services:: Essential system services.
13203 * Scheduled Job Execution:: The mcron service.
13204 * Log Rotation:: The rottlog service.
13205 * Networking Services:: Network setup, SSH daemon, etc.
13206 * Unattended Upgrades:: Automated system upgrades.
13207 * X Window:: Graphical display.
13208 * Printing Services:: Local and remote printer support.
13209 * Desktop Services:: D-Bus and desktop services.
13210 * Sound Services:: ALSA and Pulseaudio services.
13211 * Database Services:: SQL databases, key-value stores, etc.
13212 * Mail Services:: IMAP, POP3, SMTP, and all that.
13213 * Messaging Services:: Messaging services.
13214 * Telephony Services:: Telephony services.
13215 * Monitoring Services:: Monitoring services.
13216 * Kerberos Services:: Kerberos services.
13217 * LDAP Services:: LDAP services.
13218 * Web Services:: Web servers.
13219 * Certificate Services:: TLS certificates via Let's Encrypt.
13220 * DNS Services:: DNS daemons.
13221 * VPN Services:: VPN daemons.
13222 * Network File System:: NFS related services.
13223 * Continuous Integration:: The Cuirass service.
13224 * Power Management Services:: Extending battery life.
13225 * Audio Services:: The MPD.
13226 * Virtualization Services:: Virtualization services.
13227 * Version Control Services:: Providing remote access to Git repositories.
13228 * Game Services:: Game servers.
13229 * PAM Mount Service:: Service to mount volumes when logging in.
13230 * Guix Services:: Services relating specifically to Guix.
13231 * Linux Services:: Services tied to the Linux kernel.
13232 * Hurd Services:: Services specific for a Hurd System.
13233 * Miscellaneous Services:: Other services.
13236 @node Base Services
13237 @subsection Base Services
13239 The @code{(gnu services base)} module provides definitions for the basic
13240 services that one expects from the system. The services exported by
13241 this module are listed below.
13243 @defvr {Scheme Variable} %base-services
13244 This variable contains a list of basic services (@pxref{Service Types
13245 and Services}, for more information on service objects) one would
13246 expect from the system: a login service (mingetty) on each tty, syslogd,
13247 the libc name service cache daemon (nscd), the udev device manager, and
13250 This is the default value of the @code{services} field of
13251 @code{operating-system} declarations. Usually, when customizing a
13252 system, you will want to append services to @code{%base-services}, like
13256 (append (list (service avahi-service-type)
13257 (service openssh-service-type))
13262 @defvr {Scheme Variable} special-files-service-type
13263 This is the service that sets up ``special files'' such as
13264 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
13266 The value associated with @code{special-files-service-type} services
13267 must be a list of tuples where the first element is the ``special file''
13268 and the second element is its target. By default it is:
13270 @cindex @file{/bin/sh}
13271 @cindex @file{sh}, in @file{/bin}
13273 `(("/bin/sh" ,(file-append bash "/bin/sh")))
13276 @cindex @file{/usr/bin/env}
13277 @cindex @file{env}, in @file{/usr/bin}
13278 If you want to add, say, @code{/usr/bin/env} to your system, you can
13282 `(("/bin/sh" ,(file-append bash "/bin/sh"))
13283 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
13286 Since this is part of @code{%base-services}, you can use
13287 @code{modify-services} to customize the set of special files
13288 (@pxref{Service Reference, @code{modify-services}}). But the simple way
13289 to add a special file is @i{via} the @code{extra-special-file} procedure
13293 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
13294 Use @var{target} as the ``special file'' @var{file}.
13296 For example, adding the following lines to the @code{services} field of
13297 your operating system declaration leads to a @file{/usr/bin/env}
13301 (extra-special-file "/usr/bin/env"
13302 (file-append coreutils "/bin/env"))
13306 @deffn {Scheme Procedure} host-name-service @var{name}
13307 Return a service that sets the host name to @var{name}.
13310 @defvr {Scheme Variable} console-font-service-type
13311 Install the given fonts on the specified ttys (fonts are per
13312 virtual console on the kernel Linux). The value of this service is a list of
13313 tty/font pairs. The font can be the name of a font provided by the @code{kbd}
13314 package or any valid argument to @command{setfont}, as in this example:
13317 `(("tty1" . "LatGrkCyr-8x16")
13318 ("tty2" . ,(file-append
13320 "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
13321 ("tty3" . ,(file-append
13323 "/share/consolefonts/ter-132n"))) ; for HDPI
13327 @deffn {Scheme Procedure} login-service @var{config}
13328 Return a service to run login according to @var{config}, a
13329 @code{<login-configuration>} object, which specifies the message of the day,
13330 among other things.
13333 @deftp {Data Type} login-configuration
13334 This is the data type representing the configuration of login.
13339 @cindex message of the day
13340 A file-like object containing the ``message of the day''.
13342 @item @code{allow-empty-passwords?} (default: @code{#t})
13343 Allow empty passwords by default so that first-time users can log in when
13344 the 'root' account has just been created.
13349 @deffn {Scheme Procedure} mingetty-service @var{config}
13350 Return a service to run mingetty according to @var{config}, a
13351 @code{<mingetty-configuration>} object, which specifies the tty to run, among
13355 @deftp {Data Type} mingetty-configuration
13356 This is the data type representing the configuration of Mingetty, which
13357 provides the default implementation of virtual console log-in.
13362 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
13364 @item @code{auto-login} (default: @code{#f})
13365 When true, this field must be a string denoting the user name under
13366 which the system automatically logs in. When it is @code{#f}, a
13367 user name and password must be entered to log in.
13369 @item @code{login-program} (default: @code{#f})
13370 This must be either @code{#f}, in which case the default log-in program
13371 is used (@command{login} from the Shadow tool suite), or a gexp denoting
13372 the name of the log-in program.
13374 @item @code{login-pause?} (default: @code{#f})
13375 When set to @code{#t} in conjunction with @var{auto-login}, the user
13376 will have to press a key before the log-in shell is launched.
13378 @item @code{mingetty} (default: @var{mingetty})
13379 The Mingetty package to use.
13384 @deffn {Scheme Procedure} agetty-service @var{config}
13385 Return a service to run agetty according to @var{config}, an
13386 @code{<agetty-configuration>} object, which specifies the tty to run,
13387 among other things.
13390 @deftp {Data Type} agetty-configuration
13391 This is the data type representing the configuration of agetty, which
13392 implements virtual and serial console log-in. See the @code{agetty(8)}
13393 man page for more information.
13398 The name of the console this agetty runs on, as a string---e.g.,
13399 @code{"ttyS0"}. This argument is optional, it will default to
13400 a reasonable default serial port used by the kernel Linux.
13402 For this, if there is a value for an option @code{agetty.tty} in the kernel
13403 command line, agetty will extract the device name of the serial port
13404 from it and use that.
13406 If not and if there is a value for an option @code{console} with a tty in
13407 the Linux command line, agetty will extract the device name of the
13408 serial port from it and use that.
13410 In both cases, agetty will leave the other serial device settings
13411 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
13414 @item @code{baud-rate} (default: @code{#f})
13415 A string containing a comma-separated list of one or more baud rates, in
13418 @item @code{term} (default: @code{#f})
13419 A string containing the value used for the @env{TERM} environment
13422 @item @code{eight-bits?} (default: @code{#f})
13423 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
13426 @item @code{auto-login} (default: @code{#f})
13427 When passed a login name, as a string, the specified user will be logged
13428 in automatically without prompting for their login name or password.
13430 @item @code{no-reset?} (default: @code{#f})
13431 When @code{#t}, don't reset terminal cflags (control modes).
13433 @item @code{host} (default: @code{#f})
13434 This accepts a string containing the ``login_host'', which will be written
13435 into the @file{/var/run/utmpx} file.
13437 @item @code{remote?} (default: @code{#f})
13438 When set to @code{#t} in conjunction with @var{host}, this will add an
13439 @code{-r} fakehost option to the command line of the login program
13440 specified in @var{login-program}.
13442 @item @code{flow-control?} (default: @code{#f})
13443 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
13445 @item @code{no-issue?} (default: @code{#f})
13446 When set to @code{#t}, the contents of the @file{/etc/issue} file will
13447 not be displayed before presenting the login prompt.
13449 @item @code{init-string} (default: @code{#f})
13450 This accepts a string that will be sent to the tty or modem before
13451 sending anything else. It can be used to initialize a modem.
13453 @item @code{no-clear?} (default: @code{#f})
13454 When set to @code{#t}, agetty will not clear the screen before showing
13457 @item @code{login-program} (default: (file-append shadow "/bin/login"))
13458 This must be either a gexp denoting the name of a log-in program, or
13459 unset, in which case the default value is the @command{login} from the
13462 @item @code{local-line} (default: @code{#f})
13463 Control the CLOCAL line flag. This accepts one of three symbols as
13464 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
13465 the default value chosen by agetty is @code{'auto}.
13467 @item @code{extract-baud?} (default: @code{#f})
13468 When set to @code{#t}, instruct agetty to try to extract the baud rate
13469 from the status messages produced by certain types of modems.
13471 @item @code{skip-login?} (default: @code{#f})
13472 When set to @code{#t}, do not prompt the user for a login name. This
13473 can be used with @var{login-program} field to use non-standard login
13476 @item @code{no-newline?} (default: @code{#f})
13477 When set to @code{#t}, do not print a newline before printing the
13478 @file{/etc/issue} file.
13480 @c Is this dangerous only when used with login-program, or always?
13481 @item @code{login-options} (default: @code{#f})
13482 This option accepts a string containing options that are passed to the
13483 login program. When used with the @var{login-program}, be aware that a
13484 malicious user could try to enter a login name containing embedded
13485 options that could be parsed by the login program.
13487 @item @code{login-pause} (default: @code{#f})
13488 When set to @code{#t}, wait for any key before showing the login prompt.
13489 This can be used in conjunction with @var{auto-login} to save memory by
13490 lazily spawning shells.
13492 @item @code{chroot} (default: @code{#f})
13493 Change root to the specified directory. This option accepts a directory
13496 @item @code{hangup?} (default: @code{#f})
13497 Use the Linux system call @code{vhangup} to do a virtual hangup of the
13498 specified terminal.
13500 @item @code{keep-baud?} (default: @code{#f})
13501 When set to @code{#t}, try to keep the existing baud rate. The baud
13502 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
13505 @item @code{timeout} (default: @code{#f})
13506 When set to an integer value, terminate if no user name could be read
13507 within @var{timeout} seconds.
13509 @item @code{detect-case?} (default: @code{#f})
13510 When set to @code{#t}, turn on support for detecting an uppercase-only
13511 terminal. This setting will detect a login name containing only
13512 uppercase letters as indicating an uppercase-only terminal and turn on
13513 some upper-to-lower case conversions. Note that this will not support
13514 Unicode characters.
13516 @item @code{wait-cr?} (default: @code{#f})
13517 When set to @code{#t}, wait for the user or modem to send a
13518 carriage-return or linefeed character before displaying
13519 @file{/etc/issue} or login prompt. This is typically used with the
13520 @var{init-string} option.
13522 @item @code{no-hints?} (default: @code{#f})
13523 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
13526 @item @code{no-hostname?} (default: @code{#f})
13527 By default, the hostname is printed. When this option is set to
13528 @code{#t}, no hostname will be shown at all.
13530 @item @code{long-hostname?} (default: @code{#f})
13531 By default, the hostname is only printed until the first dot. When this
13532 option is set to @code{#t}, the fully qualified hostname by
13533 @code{gethostname} or @code{getaddrinfo} is shown.
13535 @item @code{erase-characters} (default: @code{#f})
13536 This option accepts a string of additional characters that should be
13537 interpreted as backspace when the user types their login name.
13539 @item @code{kill-characters} (default: @code{#f})
13540 This option accepts a string that should be interpreted to mean ``ignore
13541 all previous characters'' (also called a ``kill'' character) when the user
13542 types their login name.
13544 @item @code{chdir} (default: @code{#f})
13545 This option accepts, as a string, a directory path that will be changed
13548 @item @code{delay} (default: @code{#f})
13549 This options accepts, as an integer, the number of seconds to sleep
13550 before opening the tty and displaying the login prompt.
13552 @item @code{nice} (default: @code{#f})
13553 This option accepts, as an integer, the nice value with which to run the
13554 @command{login} program.
13556 @item @code{extra-options} (default: @code{'()})
13557 This option provides an ``escape hatch'' for the user to provide arbitrary
13558 command-line arguments to @command{agetty} as a list of strings.
13563 @deffn {Scheme Procedure} kmscon-service-type @var{config}
13564 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
13565 according to @var{config}, a @code{<kmscon-configuration>} object, which
13566 specifies the tty to run, among other things.
13569 @deftp {Data Type} kmscon-configuration
13570 This is the data type representing the configuration of Kmscon, which
13571 implements virtual console log-in.
13575 @item @code{virtual-terminal}
13576 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
13578 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
13579 A gexp denoting the name of the log-in program. The default log-in program is
13580 @command{login} from the Shadow tool suite.
13582 @item @code{login-arguments} (default: @code{'("-p")})
13583 A list of arguments to pass to @command{login}.
13585 @item @code{auto-login} (default: @code{#f})
13586 When passed a login name, as a string, the specified user will be logged
13587 in automatically without prompting for their login name or password.
13589 @item @code{hardware-acceleration?} (default: #f)
13590 Whether to use hardware acceleration.
13592 @item @code{kmscon} (default: @var{kmscon})
13593 The Kmscon package to use.
13598 @cindex name service cache daemon
13600 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
13601 [#:name-services '()]
13602 Return a service that runs the libc name service cache daemon (nscd) with the
13603 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
13604 Service Switch}, for an example.
13606 For convenience, the Shepherd service for nscd provides the following actions:
13610 @cindex cache invalidation, nscd
13611 @cindex nscd, cache invalidation
13612 This invalidate the given cache. For instance, running:
13615 herd invalidate nscd hosts
13619 invalidates the host name lookup cache of nscd.
13622 Running @command{herd statistics nscd} displays information about nscd usage
13628 @defvr {Scheme Variable} %nscd-default-configuration
13629 This is the default @code{<nscd-configuration>} value (see below) used
13630 by @code{nscd-service}. It uses the caches defined by
13631 @code{%nscd-default-caches}; see below.
13634 @deftp {Data Type} nscd-configuration
13635 This is the data type representing the name service cache daemon (nscd)
13640 @item @code{name-services} (default: @code{'()})
13641 List of packages denoting @dfn{name services} that must be visible to
13642 the nscd---e.g., @code{(list @var{nss-mdns})}.
13644 @item @code{glibc} (default: @var{glibc})
13645 Package object denoting the GNU C Library providing the @command{nscd}
13648 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
13649 Name of the nscd log file. This is where debugging output goes when
13650 @code{debug-level} is strictly positive.
13652 @item @code{debug-level} (default: @code{0})
13653 Integer denoting the debugging levels. Higher numbers mean that more
13654 debugging output is logged.
13656 @item @code{caches} (default: @code{%nscd-default-caches})
13657 List of @code{<nscd-cache>} objects denoting things to be cached; see
13663 @deftp {Data Type} nscd-cache
13664 Data type representing a cache database of nscd and its parameters.
13668 @item @code{database}
13669 This is a symbol representing the name of the database to be cached.
13670 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
13671 @code{services}, which designate the corresponding NSS database
13672 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
13674 @item @code{positive-time-to-live}
13675 @itemx @code{negative-time-to-live} (default: @code{20})
13676 A number representing the number of seconds during which a positive or
13677 negative lookup result remains in cache.
13679 @item @code{check-files?} (default: @code{#t})
13680 Whether to check for updates of the files corresponding to
13683 For instance, when @var{database} is @code{hosts}, setting this flag
13684 instructs nscd to check for updates in @file{/etc/hosts} and to take
13687 @item @code{persistent?} (default: @code{#t})
13688 Whether the cache should be stored persistently on disk.
13690 @item @code{shared?} (default: @code{#t})
13691 Whether the cache should be shared among users.
13693 @item @code{max-database-size} (default: 32@tie{}MiB)
13694 Maximum size in bytes of the database cache.
13696 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
13697 @c settings, so leave them out.
13702 @defvr {Scheme Variable} %nscd-default-caches
13703 List of @code{<nscd-cache>} objects used by default by
13704 @code{nscd-configuration} (see above).
13706 It enables persistent and aggressive caching of service and host name
13707 lookups. The latter provides better host name lookup performance,
13708 resilience in the face of unreliable name servers, and also better
13709 privacy---often the result of host name lookups is in local cache, so
13710 external name servers do not even need to be queried.
13713 @anchor{syslog-configuration-type}
13716 @deftp {Data Type} syslog-configuration
13717 This data type represents the configuration of the syslog daemon.
13720 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
13721 The syslog daemon to use.
13723 @item @code{config-file} (default: @code{%default-syslog.conf})
13724 The syslog configuration file to use.
13729 @anchor{syslog-service}
13731 @deffn {Scheme Procedure} syslog-service @var{config}
13732 Return a service that runs a syslog daemon according to @var{config}.
13734 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
13735 information on the configuration file syntax.
13738 @defvr {Scheme Variable} guix-service-type
13739 This is the type of the service that runs the build daemon,
13740 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
13741 @code{guix-configuration} record as described below.
13744 @anchor{guix-configuration-type}
13745 @deftp {Data Type} guix-configuration
13746 This data type represents the configuration of the Guix build daemon.
13747 @xref{Invoking guix-daemon}, for more information.
13750 @item @code{guix} (default: @var{guix})
13751 The Guix package to use.
13753 @item @code{build-group} (default: @code{"guixbuild"})
13754 Name of the group for build user accounts.
13756 @item @code{build-accounts} (default: @code{10})
13757 Number of build user accounts to create.
13759 @item @code{authorize-key?} (default: @code{#t})
13760 @cindex substitutes, authorization thereof
13761 Whether to authorize the substitute keys listed in
13762 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
13763 (@pxref{Substitutes}).
13765 @vindex %default-authorized-guix-keys
13766 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
13767 The list of authorized key files for archive imports, as a list of
13768 string-valued gexps (@pxref{Invoking guix archive}). By default, it
13769 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
13771 @item @code{use-substitutes?} (default: @code{#t})
13772 Whether to use substitutes.
13774 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
13775 The list of URLs where to look for substitutes by default.
13777 @item @code{max-silent-time} (default: @code{0})
13778 @itemx @code{timeout} (default: @code{0})
13779 The number of seconds of silence and the number of seconds of activity,
13780 respectively, after which a build process times out. A value of zero
13781 disables the timeout.
13783 @item @code{log-compression} (default: @code{'bzip2})
13784 The type of compression used for build logs---one of @code{gzip},
13785 @code{bzip2}, or @code{none}.
13787 @item @code{extra-options} (default: @code{'()})
13788 List of extra command-line options for @command{guix-daemon}.
13790 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
13791 File where @command{guix-daemon}'s standard output and standard error
13794 @cindex HTTP proxy, for @code{guix-daemon}
13795 @cindex proxy, for @code{guix-daemon} HTTP access
13796 @item @code{http-proxy} (default: @code{#f})
13797 The URL of the HTTP and HTTPS proxy used for downloading fixed-output
13798 derivations and substitutes.
13800 It is also possible to change the daemon's proxy at run time through the
13801 @code{set-http-proxy} action, which restarts it:
13804 herd set-http-proxy guix-daemon http://localhost:8118
13807 To clear the proxy settings, run:
13810 herd set-http-proxy guix-daemon
13813 @item @code{tmpdir} (default: @code{#f})
13814 A directory path where the @command{guix-daemon} will perform builds.
13819 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
13820 Run @var{udev}, which populates the @file{/dev} directory dynamically.
13821 udev rules can be provided as a list of files through the @var{rules}
13822 variable. The procedures @code{udev-rule}, @code{udev-rules-service}
13823 and @code{file->udev-rule} from @code{(gnu services base)} simplify the
13824 creation of such rule files.
13826 The @command{herd rules udev} command, as root, returns the name of the
13827 directory containing all the active udev rules.
13830 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
13831 Return a udev-rule file named @var{file-name} containing the rules
13832 defined by the @var{contents} literal.
13834 In the following example, a rule for a USB device is defined to be
13835 stored in the file @file{90-usb-thing.rules}. The rule runs a script
13836 upon detecting a USB device with a given product identifier.
13839 (define %example-udev-rule
13841 "90-usb-thing.rules"
13842 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
13843 "ATTR@{product@}==\"Example\", "
13844 "RUN+=\"/path/to/script\"")))
13848 @deffn {Scheme Procedure} udev-rules-service [@var{name} @var{rules}] @
13849 [#:groups @var{groups}]
13850 Return a service that extends @code{udev-service-type } with @var{rules}
13851 and @code{account-service-type} with @var{groups} as system groups.
13852 This works by creating a singleton service type
13853 @code{@var{name}-udev-rules}, of which the returned service is an
13856 Here we show how it can be used to extend @code{udev-service-type} with the
13857 previously defined rule @code{%example-udev-rule}.
13863 (cons (udev-rules-service 'usb-thing %example-udev-rule)
13864 %desktop-services)))
13868 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
13869 Return a udev file named @var{file-name} containing the rules defined
13870 within @var{file}, a file-like object.
13872 The following example showcases how we can use an existing rule file.
13875 (use-modules (guix download) ;for url-fetch
13876 (guix packages) ;for origin
13879 (define %android-udev-rules
13881 "51-android-udev.rules"
13882 (let ((version "20170910"))
13885 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
13886 "android-udev-rules/" version "/51-android.rules"))
13888 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
13892 Additionally, Guix package definitions can be included in @var{rules} in
13893 order to extend the udev rules with the definitions found under their
13894 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
13895 @var{file->udev-rule} example, we could have used the
13896 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
13897 packages android)} module.
13899 The following example shows how to use the @var{android-udev-rules}
13900 package so that the Android tool @command{adb} can detect devices
13901 without root privileges. It also details how to create the
13902 @code{adbusers} group, which is required for the proper functioning of
13903 the rules defined within the @code{android-udev-rules} package. To
13904 create such a group, we must define it both as part of the
13905 @code{supplementary-groups} of our @code{user-account} declaration, as
13906 well as in the @var{groups} of the @code{udev-rules-service} procedure.
13909 (use-modules (gnu packages android) ;for android-udev-rules
13910 (gnu system shadow) ;for user-group
13915 (users (cons (user-account
13917 (supplementary-groups
13918 '("adbusers" ;for adb
13919 "wheel" "netdev" "audio" "video")))))
13922 (cons (udev-rules-service 'android android-udev-rules
13923 #:groups '("adbusers"))
13924 %desktop-services)))
13927 @defvr {Scheme Variable} urandom-seed-service-type
13928 Save some entropy in @code{%random-seed-file} to seed @file{/dev/urandom}
13929 when rebooting. It also tries to seed @file{/dev/urandom} from
13930 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
13934 @defvr {Scheme Variable} %random-seed-file
13935 This is the name of the file where some random bytes are saved by
13936 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
13937 It defaults to @file{/var/lib/random-seed}.
13942 @defvr {Scheme Variable} gpm-service-type
13943 This is the type of the service that runs GPM, the @dfn{general-purpose
13944 mouse daemon}, which provides mouse support to the Linux console. GPM
13945 allows users to use the mouse in the console, notably to select, copy,
13948 The value for services of this type must be a @code{gpm-configuration}
13949 (see below). This service is not part of @code{%base-services}.
13952 @deftp {Data Type} gpm-configuration
13953 Data type representing the configuration of GPM.
13956 @item @code{options} (default: @code{%default-gpm-options})
13957 Command-line options passed to @command{gpm}. The default set of
13958 options instruct @command{gpm} to listen to mouse events on
13959 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
13962 @item @code{gpm} (default: @code{gpm})
13963 The GPM package to use.
13968 @anchor{guix-publish-service-type}
13969 @deffn {Scheme Variable} guix-publish-service-type
13970 This is the service type for @command{guix publish} (@pxref{Invoking
13971 guix publish}). Its value must be a @code{guix-publish-configuration}
13972 object, as described below.
13974 This assumes that @file{/etc/guix} already contains a signing key pair as
13975 created by @command{guix archive --generate-key} (@pxref{Invoking guix
13976 archive}). If that is not the case, the service will fail to start.
13979 @deftp {Data Type} guix-publish-configuration
13980 Data type representing the configuration of the @code{guix publish}
13984 @item @code{guix} (default: @code{guix})
13985 The Guix package to use.
13987 @item @code{port} (default: @code{80})
13988 The TCP port to listen for connections.
13990 @item @code{host} (default: @code{"localhost"})
13991 The host (and thus, network interface) to listen to. Use
13992 @code{"0.0.0.0"} to listen on all the network interfaces.
13994 @item @code{compression} (default: @code{'(("gzip" 3))})
13995 This is a list of compression method/level tuple used when compressing
13996 substitutes. For example, to compress all substitutes with @emph{both} lzip
13997 at level 7 and gzip at level 9, write:
14000 '(("lzip" 7) ("gzip" 9))
14003 Level 9 achieves the best compression ratio at the expense of increased CPU
14004 usage, whereas level 1 achieves fast compression.
14006 An empty list disables compression altogether.
14008 @item @code{nar-path} (default: @code{"nar"})
14009 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
14010 publish, @option{--nar-path}}, for details.
14012 @item @code{cache} (default: @code{#f})
14013 When it is @code{#f}, disable caching and instead generate archives on
14014 demand. Otherwise, this should be the name of a directory---e.g.,
14015 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
14016 archives and meta-data ready to be sent. @xref{Invoking guix publish,
14017 @option{--cache}}, for more information on the tradeoffs involved.
14019 @item @code{workers} (default: @code{#f})
14020 When it is an integer, this is the number of worker threads used for
14021 caching; when @code{#f}, the number of processors is used.
14022 @xref{Invoking guix publish, @option{--workers}}, for more information.
14024 @item @code{ttl} (default: @code{#f})
14025 When it is an integer, this denotes the @dfn{time-to-live} in seconds
14026 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
14027 for more information.
14031 @anchor{rngd-service}
14032 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
14033 [#:device "/dev/hwrng"]
14034 Return a service that runs the @command{rngd} program from @var{rng-tools}
14035 to add @var{device} to the kernel's entropy pool. The service will fail if
14036 @var{device} does not exist.
14039 @anchor{pam-limits-service}
14040 @cindex session limits
14045 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
14047 Return a service that installs a configuration file for the
14048 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
14049 @code{pam_limits} module}. The procedure optionally takes a list of
14050 @code{pam-limits-entry} values, which can be used to specify
14051 @code{ulimit} limits and nice priority limits to user sessions.
14053 The following limits definition sets two hard and soft limits for all
14054 login sessions of users in the @code{realtime} group:
14057 (pam-limits-service
14059 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
14060 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
14063 The first entry increases the maximum realtime priority for
14064 non-privileged processes; the second entry lifts any restriction of the
14065 maximum address space that can be locked in memory. These settings are
14066 commonly used for real-time audio systems.
14069 @node Scheduled Job Execution
14070 @subsection Scheduled Job Execution
14074 @cindex scheduling jobs
14075 The @code{(gnu services mcron)} module provides an interface to
14076 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
14077 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
14078 Unix @command{cron} daemon; the main difference is that it is
14079 implemented in Guile Scheme, which provides a lot of flexibility when
14080 specifying the scheduling of jobs and their actions.
14082 The example below defines an operating system that runs the
14083 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
14084 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
14085 well as the @command{mkid} command on behalf of an unprivileged user
14086 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
14087 gexps to introduce job definitions that are passed to mcron
14088 (@pxref{G-Expressions}).
14091 (use-modules (guix) (gnu) (gnu services mcron))
14092 (use-package-modules base idutils)
14094 (define updatedb-job
14095 ;; Run 'updatedb' at 3AM every day. Here we write the
14096 ;; job's action as a Scheme procedure.
14097 #~(job '(next-hour '(3))
14099 (execl (string-append #$findutils "/bin/updatedb")
14101 "--prunepaths=/tmp /var/tmp /gnu/store"))))
14103 (define garbage-collector-job
14104 ;; Collect garbage 5 minutes after midnight every day.
14105 ;; The job's action is a shell command.
14106 #~(job "5 0 * * *" ;Vixie cron syntax
14109 (define idutils-job
14110 ;; Update the index database as user "charlie" at 12:15PM
14111 ;; and 19:15PM. This runs from the user's home directory.
14112 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
14113 (string-append #$idutils "/bin/mkid src")
14118 (services (cons (service mcron-service-type
14119 (mcron-configuration
14120 (jobs (list garbage-collector-job
14126 For more complex jobs defined in Scheme where you need control over the top
14127 level, for instance to introduce a @code{use-modules} form, you can move your
14128 code to a separate program using the @code{program-file} procedure of the
14129 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
14133 (define %battery-alert-job
14134 ;; Beep when the battery percentage falls below %MIN-LEVEL.
14136 '(next-minute (range 0 60 1))
14138 "battery-alert.scm"
14139 (with-imported-modules (source-module-closure
14140 '((guix build utils)))
14142 (use-modules (guix build utils)
14145 (ice-9 textual-ports)
14148 (define %min-level 20)
14150 (setenv "LC_ALL" "C") ;ensure English output
14151 (and-let* ((input-pipe (open-pipe*
14153 #$(file-append acpi "/bin/acpi")))
14154 (output (get-string-all input-pipe))
14155 (m (string-match "Discharging, ([0-9]+)%" output))
14156 (level (string->number (match:substring m 1)))
14157 ((< level %min-level)))
14158 (format #t "warning: Battery level is low (~a%)~%" level)
14159 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
14162 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
14163 for more information on mcron job specifications. Below is the
14164 reference of the mcron service.
14166 On a running system, you can use the @code{schedule} action of the service to
14167 visualize the mcron jobs that will be executed next:
14170 # herd schedule mcron
14174 The example above lists the next five tasks that will be executed, but you can
14175 also specify the number of tasks to display:
14178 # herd schedule mcron 10
14181 @defvr {Scheme Variable} mcron-service-type
14182 This is the type of the @code{mcron} service, whose value is an
14183 @code{mcron-configuration} object.
14185 This service type can be the target of a service extension that provides
14186 it additional job specifications (@pxref{Service Composition}). In
14187 other words, it is possible to define services that provide additional
14191 @deftp {Data Type} mcron-configuration
14192 Data type representing the configuration of mcron.
14195 @item @code{mcron} (default: @var{mcron})
14196 The mcron package to use.
14199 This is a list of gexps (@pxref{G-Expressions}), where each gexp
14200 corresponds to an mcron job specification (@pxref{Syntax, mcron job
14201 specifications,, mcron, GNU@tie{}mcron}).
14207 @subsection Log Rotation
14210 @cindex log rotation
14212 Log files such as those found in @file{/var/log} tend to grow endlessly,
14213 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
14214 their contents in separate files, possibly compressed. The @code{(gnu
14215 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
14216 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
14218 This service is part of @code{%base-services}, and thus enabled by
14219 default, with the default settings, for commonly encountered log files.
14220 The example below shows how to extend it with an additional
14221 @dfn{rotation}, should you need to do that (usually, services that
14222 produce log files already take care of that):
14225 (use-modules (guix) (gnu))
14226 (use-service-modules admin)
14228 (define my-log-files
14229 ;; Log files that I want to rotate.
14230 '("/var/log/something.log" "/var/log/another.log"))
14234 (services (cons (simple-service 'rotate-my-stuff
14235 rottlog-service-type
14236 (list (log-rotation
14238 (files my-log-files))))
14242 @defvr {Scheme Variable} rottlog-service-type
14243 This is the type of the Rottlog service, whose value is a
14244 @code{rottlog-configuration} object.
14246 Other services can extend this one with new @code{log-rotation} objects
14247 (see below), thereby augmenting the set of files to be rotated.
14249 This service type can define mcron jobs (@pxref{Scheduled Job
14250 Execution}) to run the rottlog service.
14253 @deftp {Data Type} rottlog-configuration
14254 Data type representing the configuration of rottlog.
14257 @item @code{rottlog} (default: @code{rottlog})
14258 The Rottlog package to use.
14260 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
14261 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
14262 rottlog, GNU Rot[t]log Manual}).
14264 @item @code{rotations} (default: @code{%default-rotations})
14265 A list of @code{log-rotation} objects as defined below.
14268 This is a list of gexps where each gexp corresponds to an mcron job
14269 specification (@pxref{Scheduled Job Execution}).
14273 @deftp {Data Type} log-rotation
14274 Data type representing the rotation of a group of log files.
14276 Taking an example from the Rottlog manual (@pxref{Period Related File
14277 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
14283 (files '("/var/log/apache/*"))
14284 (options '("storedir apache-archives"
14290 The list of fields is as follows:
14293 @item @code{frequency} (default: @code{'weekly})
14294 The log rotation frequency, a symbol.
14297 The list of files or file glob patterns to rotate.
14299 @item @code{options} (default: @code{'()})
14300 The list of rottlog options for this rotation (@pxref{Configuration
14301 parameters,,, rottlog, GNU Rot[t]lg Manual}).
14303 @item @code{post-rotate} (default: @code{#f})
14304 Either @code{#f} or a gexp to execute once the rotation has completed.
14308 @defvr {Scheme Variable} %default-rotations
14309 Specifies weekly rotation of @code{%rotated-files} and of
14310 @file{/var/log/guix-daemon.log}.
14313 @defvr {Scheme Variable} %rotated-files
14314 The list of syslog-controlled files to be rotated. By default it is:
14315 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
14316 "/var/log/maillog")}.
14319 @node Networking Services
14320 @subsection Networking Services
14322 The @code{(gnu services networking)} module provides services to configure
14323 the network interface.
14325 @cindex DHCP, networking service
14326 @defvr {Scheme Variable} dhcp-client-service-type
14327 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
14328 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
14329 is the DHCP client package to use, @code{isc-dhcp} by default.
14332 @deffn {Scheme Procedure} dhcpd-service-type
14333 This type defines a service that runs a DHCP daemon. To create a
14334 service of this type, you must supply a @code{<dhcpd-configuration>}.
14338 (service dhcpd-service-type
14339 (dhcpd-configuration
14340 (config-file (local-file "my-dhcpd.conf"))
14341 (interfaces '("enp0s25"))))
14345 @deftp {Data Type} dhcpd-configuration
14347 @item @code{package} (default: @code{isc-dhcp})
14348 The package that provides the DHCP daemon. This package is expected to
14349 provide the daemon at @file{sbin/dhcpd} relative to its output
14350 directory. The default package is the
14351 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
14352 @item @code{config-file} (default: @code{#f})
14353 The configuration file to use. This is required. It will be passed to
14354 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
14355 object (@pxref{G-Expressions, file-like objects}). See @code{man
14356 dhcpd.conf} for details on the configuration file syntax.
14357 @item @code{version} (default: @code{"4"})
14358 The DHCP version to use. The ISC DHCP server supports the values ``4'',
14359 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
14360 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
14362 @item @code{run-directory} (default: @code{"/run/dhcpd"})
14363 The run directory to use. At service activation time, this directory
14364 will be created if it does not exist.
14365 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
14366 The PID file to use. This corresponds to the @code{-pf} option of
14367 @code{dhcpd}. See @code{man dhcpd} for details.
14368 @item @code{interfaces} (default: @code{'()})
14369 The names of the network interfaces on which dhcpd should listen for
14370 broadcasts. If this list is not empty, then its elements (which must be
14371 strings) will be appended to the @code{dhcpd} invocation when starting
14372 the daemon. It may not be necessary to explicitly specify any
14373 interfaces here; see @code{man dhcpd} for details.
14377 @defvr {Scheme Variable} static-networking-service-type
14378 This is the type for statically-configured network interfaces.
14379 @c TODO Document <static-networking> data structures.
14382 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
14383 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
14384 [#:requirement @code{'(udev)}]
14385 Return a service that starts @var{interface} with address @var{ip}. If
14386 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
14387 it must be a string specifying the default network gateway. @var{requirement}
14388 can be used to declare a dependency on another service before configuring the
14391 This procedure can be called several times, one for each network
14392 interface of interest. Behind the scenes what it does is extend
14393 @code{static-networking-service-type} with additional network interfaces
14399 (static-networking-service "eno1" "192.168.1.82"
14400 #:gateway "192.168.1.2"
14401 #:name-servers '("192.168.1.2"))
14408 @cindex network management
14409 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
14410 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
14411 management daemon that aims to simplify wired and wireless networking.
14413 This service adds the @var{wicd} package to the global profile, providing
14414 several commands to interact with the daemon and configure networking:
14415 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
14416 and @command{wicd-curses} user interfaces.
14419 @cindex ModemManager
14421 @defvr {Scheme Variable} modem-manager-service-type
14422 This is the service type for the
14423 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
14424 service. The value for this service type is a
14425 @code{modem-manager-configuration} record.
14427 This service is part of @code{%desktop-services} (@pxref{Desktop
14431 @deftp {Data Type} modem-manager-configuration
14432 Data type representing the configuration of ModemManager.
14435 @item @code{modem-manager} (default: @code{modem-manager})
14436 The ModemManager package to use.
14441 @cindex USB_ModeSwitch
14442 @cindex Modeswitching
14444 @defvr {Scheme Variable} usb-modeswitch-service-type
14445 This is the service type for the
14446 @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch} service. The
14447 value for this service type is a @code{usb-modeswitch-configuration} record.
14449 When plugged in, some USB modems (and other USB devices) initially present
14450 themselves as a read-only storage medium and not as a modem. They need to be
14451 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
14452 installs udev rules to automatically modeswitch these devices when they are
14455 This service is part of @code{%desktop-services} (@pxref{Desktop
14459 @deftp {Data Type} usb-modeswitch-configuration
14460 Data type representing the configuration of USB_ModeSwitch.
14463 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
14464 The USB_ModeSwitch package providing the binaries for modeswitching.
14466 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
14467 The package providing the device data and udev rules file used by
14470 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
14471 Which config file to use for the USB_ModeSwitch dispatcher. By default the
14472 config file shipped with USB_ModeSwitch is used which disables logging to
14473 @file{/var/log} among other default settings. If set to @code{#f}, no config
14479 @cindex NetworkManager
14481 @defvr {Scheme Variable} network-manager-service-type
14482 This is the service type for the
14483 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
14484 service. The value for this service type is a
14485 @code{network-manager-configuration} record.
14487 This service is part of @code{%desktop-services} (@pxref{Desktop
14491 @deftp {Data Type} network-manager-configuration
14492 Data type representing the configuration of NetworkManager.
14495 @item @code{network-manager} (default: @code{network-manager})
14496 The NetworkManager package to use.
14498 @item @code{dns} (default: @code{"default"})
14499 Processing mode for DNS, which affects how NetworkManager uses the
14500 @code{resolv.conf} configuration file.
14504 NetworkManager will update @code{resolv.conf} to reflect the nameservers
14505 provided by currently active connections.
14508 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
14509 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
14510 then update @code{resolv.conf} to point to the local nameserver.
14512 With this setting, you can share your network connection. For example when
14513 you want to share your network connection to another laptop @i{via} an
14514 Ethernet cable, you can open @command{nm-connection-editor} and configure the
14515 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
14516 and reestablish the connection (or reboot).
14518 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
14519 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
14520 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
14521 browser on your host system, or connect to the VM @i{via} SSH
14522 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
14523 host-to-guest connection, run this command once:
14526 nmcli connection add type tun \
14527 connection.interface-name tap0 \
14528 tun.mode tap tun.owner $(id -u) \
14529 ipv4.method shared \
14530 ipv4.addresses 172.28.112.1/24
14533 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
14534 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
14535 @command{qemu-system-...}.
14538 NetworkManager will not modify @code{resolv.conf}.
14541 @item @code{vpn-plugins} (default: @code{'()})
14542 This is the list of available plugins for virtual private networks
14543 (VPNs). An example of this is the @code{network-manager-openvpn}
14544 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
14550 @deffn {Scheme Variable} connman-service-type
14551 This is the service type to run @url{https://01.org/connman,Connman},
14552 a network connection manager.
14554 Its value must be an
14555 @code{connman-configuration} record as in this example:
14558 (service connman-service-type
14559 (connman-configuration
14560 (disable-vpn? #t)))
14563 See below for details about @code{connman-configuration}.
14566 @deftp {Data Type} connman-configuration
14567 Data Type representing the configuration of connman.
14570 @item @code{connman} (default: @var{connman})
14571 The connman package to use.
14573 @item @code{disable-vpn?} (default: @code{#f})
14574 When true, disable connman's vpn plugin.
14578 @cindex WPA Supplicant
14579 @defvr {Scheme Variable} wpa-supplicant-service-type
14580 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
14581 supplicant}, an authentication daemon required to authenticate against
14582 encrypted WiFi or ethernet networks.
14585 @deftp {Data Type} wpa-supplicant-configuration
14586 Data type representing the configuration of WPA Supplicant.
14588 It takes the following parameters:
14591 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
14592 The WPA Supplicant package to use.
14594 @item @code{requirement} (default: @code{'(user-processes dbus-system loopback syslogd)}
14595 List of services that should be started before WPA Supplicant starts.
14597 @item @code{dbus?} (default: @code{#t})
14598 Whether to listen for requests on D-Bus.
14600 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
14601 Where to store the PID file.
14603 @item @code{interface} (default: @code{#f})
14604 If this is set, it must specify the name of a network interface that
14605 WPA supplicant will control.
14607 @item @code{config-file} (default: @code{#f})
14608 Optional configuration file to use.
14610 @item @code{extra-options} (default: @code{'()})
14611 List of additional command-line arguments to pass to the daemon.
14615 @cindex hostapd service, for Wi-Fi access points
14616 @cindex Wi-Fi access points, hostapd service
14617 @defvr {Scheme Variable} hostapd-service-type
14618 This is the service type to run the @uref{https://w1.fi/hostapd/,
14619 hostapd} daemon to set up WiFi (IEEE 802.11) access points and
14620 authentication servers. Its associated value must be a
14621 @code{hostapd-configuration} as shown below:
14624 ;; Use wlan1 to run the access point for "My Network".
14625 (service hostapd-service-type
14626 (hostapd-configuration
14627 (interface "wlan1")
14628 (ssid "My Network")
14633 @deftp {Data Type} hostapd-configuration
14634 This data type represents the configuration of the hostapd service, with
14635 the following fields:
14638 @item @code{package} (default: @code{hostapd})
14639 The hostapd package to use.
14641 @item @code{interface} (default: @code{"wlan0"})
14642 The network interface to run the WiFi access point.
14645 The SSID (@dfn{service set identifier}), a string that identifies this
14648 @item @code{broadcast-ssid?} (default: @code{#t})
14649 Whether to broadcast this SSID.
14651 @item @code{channel} (default: @code{1})
14652 The WiFi channel to use.
14654 @item @code{driver} (default: @code{"nl80211"})
14655 The driver interface type. @code{"nl80211"} is used with all Linux
14656 mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
14657 RADIUS server that does # not control any wireless/wired driver.
14659 @item @code{extra-settings} (default: @code{""})
14660 Extra settings to append as-is to the hostapd configuration file. See
14661 @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
14662 configuration file reference.
14666 @defvr {Scheme Variable} simulated-wifi-service-type
14667 This is the type of a service to simulate WiFi networking, which can be
14668 useful in virtual machines for testing purposes. The service loads the
14670 @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
14671 @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
14672 network that can be seen on @code{wlan0}, by default.
14674 The service's value is a @code{hostapd-configuration} record.
14678 @defvr {Scheme Variable} iptables-service-type
14679 This is the service type to set up an iptables configuration. iptables is a
14680 packet filtering framework supported by the Linux kernel. This service
14681 supports configuring iptables for both IPv4 and IPv6. A simple example
14682 configuration rejecting all incoming connections except those to the ssh port
14686 (service iptables-service-type
14687 (iptables-configuration
14688 (ipv4-rules (plain-file "iptables.rules" "*filter
14692 -A INPUT -p tcp --dport 22 -j ACCEPT
14693 -A INPUT -j REJECT --reject-with icmp-port-unreachable
14696 (ipv6-rules (plain-file "ip6tables.rules" "*filter
14700 -A INPUT -p tcp --dport 22 -j ACCEPT
14701 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
14707 @deftp {Data Type} iptables-configuration
14708 The data type representing the configuration of iptables.
14711 @item @code{iptables} (default: @code{iptables})
14712 The iptables package that provides @code{iptables-restore} and
14713 @code{ip6tables-restore}.
14714 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
14715 The iptables rules to use. It will be passed to @code{iptables-restore}.
14716 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
14718 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
14719 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
14720 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
14726 @defvr {Scheme Variable} nftables-service-type
14727 This is the service type to set up a nftables configuration. nftables is a
14728 netfilter project that aims to replace the existing iptables, ip6tables,
14729 arptables and ebtables framework. It provides a new packet filtering
14730 framework, a new user-space utility @command{nft}, and a compatibility layer
14731 for iptables. This service comes with a default ruleset
14732 @code{%default-nftables-ruleset} that rejecting all incomming connections
14733 except those to the ssh port 22. To use it, simply write:
14736 (service nftables-service-type)
14740 @deftp {Data Type} nftables-configuration
14741 The data type representing the configuration of nftables.
14744 @item @code{package} (default: @code{nftables})
14745 The nftables package that provides @command{nft}.
14746 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
14747 The nftables ruleset to use. This may be any ``file-like'' object
14748 (@pxref{G-Expressions, file-like objects}).
14752 @cindex NTP (Network Time Protocol), service
14753 @cindex ntpd, service for the Network Time Protocol daemon
14754 @cindex real time clock
14755 @defvr {Scheme Variable} ntp-service-type
14756 This is the type of the service running the @uref{https://www.ntp.org,
14757 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
14758 system clock synchronized with that of the specified NTP servers.
14760 The value of this service is an @code{ntpd-configuration} object, as described
14764 @deftp {Data Type} ntp-configuration
14765 This is the data type for the NTP service configuration.
14768 @item @code{servers} (default: @code{%ntp-servers})
14769 This is the list of servers (@code{<ntp-server>} records) with which
14770 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
14773 @item @code{allow-large-adjustment?} (default: @code{#t})
14774 This determines whether @command{ntpd} is allowed to make an initial
14775 adjustment of more than 1,000 seconds.
14777 @item @code{ntp} (default: @code{ntp})
14778 The NTP package to use.
14782 @defvr {Scheme Variable} %ntp-servers
14783 List of host names used as the default NTP servers. These are servers of the
14784 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
14787 @deftp {Data Type} ntp-server
14788 The data type representing the configuration of a NTP server.
14791 @item @code{type} (default: @code{'server})
14792 The type of the NTP server, given as a symbol. One of @code{'pool},
14793 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
14795 @item @code{address}
14796 The address of the server, as a string.
14798 @item @code{options}
14799 NTPD options to use with that specific server, given as a list of option names
14800 and/or of option names and values tuples. The following example define a server
14801 to use with the options @option{iburst} and @option{prefer}, as well as
14802 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
14807 (address "some.ntp.server.org")
14808 (options `(iburst (version 3) (maxpoll 16) prefer))))
14814 @deffn {Scheme Procedure} openntpd-service-type
14815 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
14816 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
14817 clock synchronized with that of the given servers.
14821 openntpd-service-type
14822 (openntpd-configuration
14823 (listen-on '("127.0.0.1" "::1"))
14824 (sensor '("udcf0 correction 70000"))
14825 (constraint-from '("www.gnu.org"))
14826 (constraints-from '("https://www.google.com/"))
14827 (allow-large-adjustment? #t)))
14832 @defvr {Scheme Variable} %openntpd-servers
14833 This variable is a list of the server addresses defined in
14834 @code{%ntp-servers}.
14837 @deftp {Data Type} openntpd-configuration
14839 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
14840 The openntpd executable to use.
14841 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
14842 A list of local IP addresses or hostnames the ntpd daemon should listen on.
14843 @item @code{query-from} (default: @code{'()})
14844 A list of local IP address the ntpd daemon should use for outgoing queries.
14845 @item @code{sensor} (default: @code{'()})
14846 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
14847 will listen to each sensor that actually exists and ignore non-existent ones.
14848 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
14850 @item @code{server} (default: @code{'()})
14851 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
14852 @item @code{servers} (default: @code{%openntp-servers})
14853 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
14854 @item @code{constraint-from} (default: @code{'()})
14855 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
14856 This time information is not used for precision but acts as an authenticated
14857 constraint, thereby reducing the impact of unauthenticated NTP
14858 man-in-the-middle attacks.
14859 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
14861 @item @code{constraints-from} (default: @code{'()})
14862 As with constraint from, specify a list of URLs, IP addresses or hostnames of
14863 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
14864 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
14865 @item @code{allow-large-adjustment?} (default: @code{#f})
14866 Determines if @code{ntpd} is allowed to make an initial adjustment of more
14872 @deffn {Scheme variable} inetd-service-type
14873 This service runs the @command{inetd} (@pxref{inetd invocation,,,
14874 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
14875 connections on internet sockets, and lazily starts the specified server
14876 program when a connection is made on one of these sockets.
14878 The value of this service is an @code{inetd-configuration} object. The
14879 following example configures the @command{inetd} daemon to provide the
14880 built-in @command{echo} service, as well as an smtp service which
14881 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
14882 gateway @code{hostname}:
14887 (inetd-configuration
14891 (socket-type 'stream)
14898 (socket-type 'stream)
14902 (program (file-append openssh "/bin/ssh"))
14904 '("ssh" "-qT" "-i" "/path/to/ssh_key"
14905 "-W" "smtp-server:25" "user@@hostname")))))))
14908 See below for more details about @code{inetd-configuration}.
14911 @deftp {Data Type} inetd-configuration
14912 Data type representing the configuration of @command{inetd}.
14915 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
14916 The @command{inetd} executable to use.
14918 @item @code{entries} (default: @code{'()})
14919 A list of @command{inetd} service entries. Each entry should be created
14920 by the @code{inetd-entry} constructor.
14924 @deftp {Data Type} inetd-entry
14925 Data type representing an entry in the @command{inetd} configuration.
14926 Each entry corresponds to a socket where @command{inetd} will listen for
14930 @item @code{node} (default: @code{#f})
14931 Optional string, a comma-separated list of local addresses
14932 @command{inetd} should use when listening for this service.
14933 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
14934 description of all options.
14936 A string, the name must correspond to an entry in @code{/etc/services}.
14937 @item @code{socket-type}
14938 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
14940 @item @code{protocol}
14941 A string, must correspond to an entry in @code{/etc/protocols}.
14942 @item @code{wait?} (default: @code{#t})
14943 Whether @command{inetd} should wait for the server to exit before
14944 listening to new service requests.
14946 A string containing the user (and, optionally, group) name of the user
14947 as whom the server should run. The group name can be specified in a
14948 suffix, separated by a colon or period, i.e.@: @code{"user"},
14949 @code{"user:group"} or @code{"user.group"}.
14950 @item @code{program} (default: @code{"internal"})
14951 The server program which will serve the requests, or @code{"internal"}
14952 if @command{inetd} should use a built-in service.
14953 @item @code{arguments} (default: @code{'()})
14954 A list strings or file-like objects, which are the server program's
14955 arguments, starting with the zeroth argument, i.e.@: the name of the
14956 program itself. For @command{inetd}'s internal services, this entry
14957 must be @code{'()} or @code{'("internal")}.
14960 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
14961 detailed discussion of each configuration field.
14965 @defvr {Scheme Variable} tor-service-type
14966 This is the type for a service that runs the @uref{https://torproject.org,
14967 Tor} anonymous networking daemon. The service is configured using a
14968 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
14969 @code{tor} unprivileged user, which is a member of the @code{tor} group.
14973 @deftp {Data Type} tor-configuration
14975 @item @code{tor} (default: @code{tor})
14976 The package that provides the Tor daemon. This package is expected to provide
14977 the daemon at @file{bin/tor} relative to its output directory. The default
14978 package is the @uref{https://www.torproject.org, Tor Project's}
14981 @item @code{config-file} (default: @code{(plain-file "empty" "")})
14982 The configuration file to use. It will be appended to a default configuration
14983 file, and the final configuration file will be passed to @code{tor} via its
14984 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
14985 file-like objects}). See @code{man tor} for details on the configuration file
14988 @item @code{hidden-services} (default: @code{'()})
14989 The list of @code{<hidden-service>} records to use. For any hidden service
14990 you include in this list, appropriate configuration to enable the hidden
14991 service will be automatically added to the default configuration file. You
14992 may conveniently create @code{<hidden-service>} records using the
14993 @code{tor-hidden-service} procedure described below.
14995 @item @code{socks-socket-type} (default: @code{'tcp})
14996 The default socket type that Tor should use for its SOCKS socket. This must
14997 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
14998 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
14999 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
15000 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
15003 If you want to customize the SOCKS socket in more detail, leave
15004 @code{socks-socket-type} at its default value of @code{'tcp} and use
15005 @code{config-file} to override the default by providing your own
15006 @code{SocksPort} option.
15010 @cindex hidden service
15011 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
15012 Define a new Tor @dfn{hidden service} called @var{name} and implementing
15013 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
15016 '((22 "127.0.0.1:22")
15017 (80 "127.0.0.1:8080"))
15020 In this example, port 22 of the hidden service is mapped to local port 22, and
15021 port 80 is mapped to local port 8080.
15023 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
15024 the @file{hostname} file contains the @code{.onion} host name for the hidden
15027 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
15028 project's documentation} for more information.
15031 The @code{(gnu services rsync)} module provides the following services:
15033 You might want an rsync daemon if you have files that you want available
15034 so anyone (or just yourself) can download existing files or upload new
15037 @deffn {Scheme Variable} rsync-service-type
15038 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
15039 The value for this service type is a
15040 @command{rsync-configuration} record as in this example:
15043 (service rsync-service-type)
15046 See below for details about @code{rsync-configuration}.
15049 @deftp {Data Type} rsync-configuration
15050 Data type representing the configuration for @code{rsync-service}.
15053 @item @code{package} (default: @var{rsync})
15054 @code{rsync} package to use.
15056 @item @code{port-number} (default: @code{873})
15057 TCP port on which @command{rsync} listens for incoming connections. If port
15058 is less than @code{1024} @command{rsync} needs to be started as the
15059 @code{root} user and group.
15061 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
15062 Name of the file where @command{rsync} writes its PID.
15064 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
15065 Name of the file where @command{rsync} writes its lock file.
15067 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
15068 Name of the file where @command{rsync} writes its log file.
15070 @item @code{use-chroot?} (default: @var{#t})
15071 Whether to use chroot for @command{rsync} shared directory.
15073 @item @code{share-path} (default: @file{/srv/rsync})
15074 Location of the @command{rsync} shared directory.
15076 @item @code{share-comment} (default: @code{"Rsync share"})
15077 Comment of the @command{rsync} shared directory.
15079 @item @code{read-only?} (default: @var{#f})
15080 Read-write permissions to shared directory.
15082 @item @code{timeout} (default: @code{300})
15083 I/O timeout in seconds.
15085 @item @code{user} (default: @var{"root"})
15086 Owner of the @code{rsync} process.
15088 @item @code{group} (default: @var{"root"})
15089 Group of the @code{rsync} process.
15091 @item @code{uid} (default: @var{"rsyncd"})
15092 User name or user ID that file transfers to and from that module should take
15093 place as when the daemon was run as @code{root}.
15095 @item @code{gid} (default: @var{"rsyncd"})
15096 Group name or group ID that will be used when accessing the module.
15101 Furthermore, @code{(gnu services ssh)} provides the following services.
15105 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
15106 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
15107 [#:allow-empty-passwords? #f] [#:root-login? #f] @
15108 [#:syslog-output? #t] [#:x11-forwarding? #t] @
15109 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
15110 [#:public-key-authentication? #t] [#:initialize? #t]
15111 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
15112 @var{host-key} must designate a file containing the host key, and readable
15115 When @var{daemonic?} is true, @command{lshd} will detach from the
15116 controlling terminal and log its output to syslogd, unless one sets
15117 @var{syslog-output?} to false. Obviously, it also makes lsh-service
15118 depend on existence of syslogd service. When @var{pid-file?} is true,
15119 @command{lshd} writes its PID to the file called @var{pid-file}.
15121 When @var{initialize?} is true, automatically create the seed and host key
15122 upon service activation if they do not exist yet. This may take long and
15123 require interaction.
15125 When @var{initialize?} is false, it is up to the user to initialize the
15126 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
15127 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
15128 basics,,, lsh, LSH Manual}).
15130 When @var{interfaces} is empty, lshd listens for connections on all the
15131 network interfaces; otherwise, @var{interfaces} must be a list of host names
15134 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
15135 passwords, and @var{root-login?} specifies whether to accept log-ins as
15138 The other options should be self-descriptive.
15143 @deffn {Scheme Variable} openssh-service-type
15144 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
15145 shell daemon, @command{sshd}. Its value must be an
15146 @code{openssh-configuration} record as in this example:
15149 (service openssh-service-type
15150 (openssh-configuration
15151 (x11-forwarding? #t)
15152 (permit-root-login 'without-password)
15154 `(("alice" ,(local-file "alice.pub"))
15155 ("bob" ,(local-file "bob.pub"))))))
15158 See below for details about @code{openssh-configuration}.
15160 This service can be extended with extra authorized keys, as in this
15164 (service-extension openssh-service-type
15165 (const `(("charlie"
15166 ,(local-file "charlie.pub")))))
15170 @deftp {Data Type} openssh-configuration
15171 This is the configuration record for OpenSSH's @command{sshd}.
15174 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
15175 Name of the file where @command{sshd} writes its PID.
15177 @item @code{port-number} (default: @code{22})
15178 TCP port on which @command{sshd} listens for incoming connections.
15180 @item @code{permit-root-login} (default: @code{#f})
15181 This field determines whether and when to allow logins as root. If
15182 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
15183 If it's the symbol @code{'without-password}, then root logins are
15184 permitted but not with password-based authentication.
15186 @item @code{allow-empty-passwords?} (default: @code{#f})
15187 When true, users with empty passwords may log in. When false, they may
15190 @item @code{password-authentication?} (default: @code{#t})
15191 When true, users may log in with their password. When false, they have
15192 other authentication methods.
15194 @item @code{public-key-authentication?} (default: @code{#t})
15195 When true, users may log in using public key authentication. When
15196 false, users have to use other authentication method.
15198 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
15199 This is used only by protocol version 2.
15201 @item @code{x11-forwarding?} (default: @code{#f})
15202 When true, forwarding of X11 graphical client connections is
15203 enabled---in other words, @command{ssh} options @option{-X} and
15204 @option{-Y} will work.
15206 @item @code{allow-agent-forwarding?} (default: @code{#t})
15207 Whether to allow agent forwarding.
15209 @item @code{allow-tcp-forwarding?} (default: @code{#t})
15210 Whether to allow TCP forwarding.
15212 @item @code{gateway-ports?} (default: @code{#f})
15213 Whether to allow gateway ports.
15215 @item @code{challenge-response-authentication?} (default: @code{#f})
15216 Specifies whether challenge response authentication is allowed (e.g.@: via
15219 @item @code{use-pam?} (default: @code{#t})
15220 Enables the Pluggable Authentication Module interface. If set to
15221 @code{#t}, this will enable PAM authentication using
15222 @code{challenge-response-authentication?} and
15223 @code{password-authentication?}, in addition to PAM account and session
15224 module processing for all authentication types.
15226 Because PAM challenge response authentication usually serves an
15227 equivalent role to password authentication, you should disable either
15228 @code{challenge-response-authentication?} or
15229 @code{password-authentication?}.
15231 @item @code{print-last-log?} (default: @code{#t})
15232 Specifies whether @command{sshd} should print the date and time of the
15233 last user login when a user logs in interactively.
15235 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
15236 Configures external subsystems (e.g.@: file transfer daemon).
15238 This is a list of two-element lists, each of which containing the
15239 subsystem name and a command (with optional arguments) to execute upon
15242 The command @command{internal-sftp} implements an in-process SFTP
15243 server. Alternatively, one can specify the @command{sftp-server} command:
15245 (service openssh-service-type
15246 (openssh-configuration
15248 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
15251 @item @code{accepted-environment} (default: @code{'()})
15252 List of strings describing which environment variables may be exported.
15254 Each string gets on its own line. See the @code{AcceptEnv} option in
15255 @code{man sshd_config}.
15257 This example allows ssh-clients to export the @env{COLORTERM} variable.
15258 It is set by terminal emulators, which support colors. You can use it in
15259 your shell's resource file to enable colors for the prompt and commands
15260 if this variable is set.
15263 (service openssh-service-type
15264 (openssh-configuration
15265 (accepted-environment '("COLORTERM"))))
15268 @item @code{authorized-keys} (default: @code{'()})
15269 @cindex authorized keys, SSH
15270 @cindex SSH authorized keys
15271 This is the list of authorized keys. Each element of the list is a user
15272 name followed by one or more file-like objects that represent SSH public
15276 (openssh-configuration
15278 `(("rekado" ,(local-file "rekado.pub"))
15279 ("chris" ,(local-file "chris.pub"))
15280 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
15284 registers the specified public keys for user accounts @code{rekado},
15285 @code{chris}, and @code{root}.
15287 Additional authorized keys can be specified @i{via}
15288 @code{service-extension}.
15290 Note that this does @emph{not} interfere with the use of
15291 @file{~/.ssh/authorized_keys}.
15293 @item @code{log-level} (default: @code{'info})
15294 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
15295 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
15296 page for @file{sshd_config} for the full list of level names.
15298 @item @code{extra-content} (default: @code{""})
15299 This field can be used to append arbitrary text to the configuration file. It
15300 is especially useful for elaborate configurations that cannot be expressed
15301 otherwise. This configuration, for example, would generally disable root
15302 logins, but permit them from one specific IP address:
15305 (openssh-configuration
15307 Match Address 192.168.0.1
15308 PermitRootLogin yes"))
15314 @deffn {Scheme Procedure} dropbear-service [@var{config}]
15315 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
15316 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
15319 For example, to specify a Dropbear service listening on port 1234, add
15320 this call to the operating system's @code{services} field:
15323 (dropbear-service (dropbear-configuration
15324 (port-number 1234)))
15328 @deftp {Data Type} dropbear-configuration
15329 This data type represents the configuration of a Dropbear SSH daemon.
15332 @item @code{dropbear} (default: @var{dropbear})
15333 The Dropbear package to use.
15335 @item @code{port-number} (default: 22)
15336 The TCP port where the daemon waits for incoming connections.
15338 @item @code{syslog-output?} (default: @code{#t})
15339 Whether to enable syslog output.
15341 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
15342 File name of the daemon's PID file.
15344 @item @code{root-login?} (default: @code{#f})
15345 Whether to allow @code{root} logins.
15347 @item @code{allow-empty-passwords?} (default: @code{#f})
15348 Whether to allow empty passwords.
15350 @item @code{password-authentication?} (default: @code{#t})
15351 Whether to enable password-based authentication.
15356 @deffn {Scheme Variable} autossh-service-type
15357 This is the type for the @uref{https://www.harding.motd.ca/autossh,
15358 AutoSSH} program that runs a copy of @command{ssh} and monitors it,
15359 restarting it as necessary should it die or stop passing traffic.
15360 AutoSSH can be run manually from the command-line by passing arguments
15361 to the binary @command{autossh} from the package @code{autossh}, but it
15362 can also be run as a Guix service. This latter use case is documented
15365 AutoSSH can be used to forward local traffic to a remote machine using
15366 an SSH tunnel, and it respects the @file{~/.ssh/config} of the user it
15369 For example, to specify a service running autossh as the user
15370 @code{pino} and forwarding all local connections to port @code{8081} to
15371 @code{remote:8081} using an SSH tunnel, add this call to the operating
15372 system's @code{services} field:
15375 (service autossh-service-type
15376 (autossh-configuration
15378 (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
15382 @deftp {Data Type} autossh-configuration
15383 This data type represents the configuration of an AutoSSH service.
15387 @item @code{user} (default @code{"autossh"})
15388 The user as which the AutoSSH service is to be run.
15389 This assumes that the specified user exists.
15391 @item @code{poll} (default @code{600})
15392 Specifies the connection poll time in seconds.
15394 @item @code{first-poll} (default @code{#f})
15395 Specifies how many seconds AutoSSH waits before the first connection
15396 test. After this first test, polling is resumed at the pace defined in
15397 @code{poll}. When set to @code{#f}, the first poll is not treated
15398 specially and will also use the connection poll specified in
15401 @item @code{gate-time} (default @code{30})
15402 Specifies how many seconds an SSH connection must be active before it is
15403 considered successful.
15405 @item @code{log-level} (default @code{1})
15406 The log level, corresponding to the levels used by syslog---so @code{0}
15407 is the most silent while @code{7} is the chattiest.
15409 @item @code{max-start} (default @code{#f})
15410 The maximum number of times SSH may be (re)started before AutoSSH exits.
15411 When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
15413 @item @code{message} (default @code{""})
15414 The message to append to the echo message sent when testing connections.
15416 @item @code{port} (default @code{"0"})
15417 The ports used for monitoring the connection. When set to @code{"0"},
15418 monitoring is disabled. When set to @code{"@var{n}"} where @var{n} is
15419 a positive integer, ports @var{n} and @var{n}+1 are used for
15420 monitoring the connection, such that port @var{n} is the base
15421 monitoring port and @code{n+1} is the echo port. When set to
15422 @code{"@var{n}:@var{m}"} where @var{n} and @var{m} are positive
15423 integers, the ports @var{n} and @var{m} are used for monitoring the
15424 connection, such that port @var{n} is the base monitoring port and
15425 @var{m} is the echo port.
15427 @item @code{ssh-options} (default @code{'()})
15428 The list of command-line arguments to pass to @command{ssh} when it is
15429 run. Options @option{-f} and @option{-M} are reserved for AutoSSH and
15430 may cause undefined behaviour.
15435 @defvr {Scheme Variable} %facebook-host-aliases
15436 This variable contains a string for use in @file{/etc/hosts}
15437 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
15438 line contains a entry that maps a known server name of the Facebook
15439 on-line service---e.g., @code{www.facebook.com}---to the local
15440 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
15442 This variable is typically used in the @code{hosts-file} field of an
15443 @code{operating-system} declaration (@pxref{operating-system Reference,
15444 @file{/etc/hosts}}):
15447 (use-modules (gnu) (guix))
15450 (host-name "mymachine")
15453 ;; Create a /etc/hosts file with aliases for "localhost"
15454 ;; and "mymachine", as well as for Facebook servers.
15455 (plain-file "hosts"
15456 (string-append (local-host-aliases host-name)
15457 %facebook-host-aliases))))
15460 This mechanism can prevent programs running locally, such as Web
15461 browsers, from accessing Facebook.
15464 The @code{(gnu services avahi)} provides the following definition.
15466 @defvr {Scheme Variable} avahi-service-type
15467 This is the service that runs @command{avahi-daemon}, a system-wide
15468 mDNS/DNS-SD responder that allows for service discovery and
15469 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
15470 Its value must be a @code{zero-configuration} record---see below.
15472 This service extends the name service cache daemon (nscd) so that it can
15473 resolve @code{.local} host names using
15474 @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
15475 Service Switch}, for information on host name resolution.
15477 Additionally, add the @var{avahi} package to the system profile so that
15478 commands such as @command{avahi-browse} are directly usable.
15481 @deftp {Data Type} avahi-configuration
15482 Data type representation the configuration for Avahi.
15486 @item @code{host-name} (default: @code{#f})
15487 If different from @code{#f}, use that as the host name to
15488 publish for this machine; otherwise, use the machine's actual host name.
15490 @item @code{publish?} (default: @code{#t})
15491 When true, allow host names and services to be published (broadcast) over the
15494 @item @code{publish-workstation?} (default: @code{#t})
15495 When true, @command{avahi-daemon} publishes the machine's host name and IP
15496 address via mDNS on the local network. To view the host names published on
15497 your local network, you can run:
15500 avahi-browse _workstation._tcp
15503 @item @code{wide-area?} (default: @code{#f})
15504 When true, DNS-SD over unicast DNS is enabled.
15506 @item @code{ipv4?} (default: @code{#t})
15507 @itemx @code{ipv6?} (default: @code{#t})
15508 These fields determine whether to use IPv4/IPv6 sockets.
15510 @item @code{domains-to-browse} (default: @code{'()})
15511 This is a list of domains to browse.
15515 @deffn {Scheme Variable} openvswitch-service-type
15516 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
15517 service, whose value should be an @code{openvswitch-configuration}
15521 @deftp {Data Type} openvswitch-configuration
15522 Data type representing the configuration of Open vSwitch, a multilayer
15523 virtual switch which is designed to enable massive network automation
15524 through programmatic extension.
15527 @item @code{package} (default: @var{openvswitch})
15528 Package object of the Open vSwitch.
15533 @defvr {Scheme Variable} pagekite-service-type
15534 This is the service type for the @uref{https://pagekite.net, PageKite} service,
15535 a tunneling solution for making localhost servers publicly visible, even from
15536 behind restrictive firewalls or NAT without forwarded ports. The value for
15537 this service type is a @code{pagekite-configuration} record.
15539 Here's an example exposing the local HTTP and SSH daemons:
15542 (service pagekite-service-type
15543 (pagekite-configuration
15544 (kites '("http:@@kitename:localhost:80:@@kitesecret"
15545 "raw/22:@@kitename:localhost:22:@@kitesecret"))
15546 (extra-file "/etc/pagekite.rc")))
15550 @deftp {Data Type} pagekite-configuration
15551 Data type representing the configuration of PageKite.
15554 @item @code{package} (default: @var{pagekite})
15555 Package object of PageKite.
15557 @item @code{kitename} (default: @code{#f})
15558 PageKite name for authenticating to the frontend server.
15560 @item @code{kitesecret} (default: @code{#f})
15561 Shared secret for authenticating to the frontend server. You should probably
15562 put this inside @code{extra-file} instead.
15564 @item @code{frontend} (default: @code{#f})
15565 Connect to the named PageKite frontend server instead of the
15566 @uref{https://pagekite.net,,pagekite.net} service.
15568 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
15569 List of service kites to use. Exposes HTTP on port 80 by default. The format
15570 is @code{proto:kitename:host:port:secret}.
15572 @item @code{extra-file} (default: @code{#f})
15573 Extra configuration file to read, which you are expected to create manually.
15574 Use this to add additional options and manage shared secrets out-of-band.
15579 @node Unattended Upgrades
15580 @subsection Unattended Upgrades
15582 @cindex unattended upgrades
15583 @cindex upgrades, unattended
15584 Guix provides a service to perform @emph{unattended upgrades}:
15585 periodically, the system automatically reconfigures itself from the
15586 latest Guix. Guix System has several properties that make unattended
15591 upgrades are transactional (either the upgrade succeeds or it fails, but
15592 you cannot end up with an ``in-between'' system state);
15594 the upgrade log is kept---you can view it with @command{guix system
15595 list-generations}---and you can roll back to any previous generation,
15596 should the upgraded system fail to behave as intended;
15598 channel code is authenticated so you know you can only run genuine code
15599 (@pxref{Channels});
15601 @command{guix system reconfigure} prevents downgrades, which makes it
15602 immune to @dfn{downgrade attacks}.
15605 To set up unattended upgrades, add an instance of
15606 @code{unattended-upgrade-service-type} like the one below to the list of
15607 your operating system services:
15610 (service unattended-upgrade-service-type)
15613 The defaults above set up weekly upgrades: every Sunday at midnight.
15614 You do not need to provide the operating system configuration file: it
15615 uses @file{/run/current-system/configuration.scm}, which ensures it
15616 always uses your latest configuration---@pxref{provenance-service-type},
15617 for more information about this file.
15619 There are several things that can be configured, in particular the
15620 periodicity and services (daemons) to be restarted upon completion.
15621 When the upgrade is successful, the service takes care of deleting
15622 system generations older that some threshold, as per @command{guix
15623 system delete-generations}. See the reference below for details.
15625 To ensure that upgrades are actually happening, you can run
15626 @command{guix system describe}. To investigate upgrade failures, visit
15627 the unattended upgrade log file (see below).
15629 @defvr {Scheme Variable} unattended-upgrade-service-type
15630 This is the service type for unattended upgrades. It sets up an mcron
15631 job (@pxref{Scheduled Job Execution}) that runs @command{guix system
15632 reconfigure} from the latest version of the specified channels.
15634 Its value must be a @code{unattended-upgrade-configuration} record (see
15638 @deftp {Data Type} unattended-upgrade-configuration
15639 This data type represents the configuration of the unattended upgrade
15640 service. The following fields are available:
15643 @item @code{schedule} (default: @code{"30 01 * * 0"})
15644 This is the schedule of upgrades, expressed as a gexp containing an
15645 mcron job schedule (@pxref{Guile Syntax, mcron job specifications,,
15646 mcron, GNU@tie{}mcron}).
15648 @item @code{channels} (default: @code{#~%default-channels})
15649 This gexp specifies the channels to use for the upgrade
15650 (@pxref{Channels}). By default, the tip of the official @code{guix}
15653 @item @code{operating-system-file} (default: @code{"/run/current-system/configuration.scm"})
15654 This field specifies the operating system configuration file to use.
15655 The default is to reuse the config file of the current configuration.
15657 There are cases, though, where referring to
15658 @file{/run/current-system/configuration.scm} is not enough, for instance
15659 because that file refers to extra files (SSH public keys, extra
15660 configuration files, etc.) @i{via} @code{local-file} and similar
15661 constructs. For those cases, we recommend something along these lines:
15664 (unattended-upgrade-configuration
15665 (operating-system-file
15666 (file-append (local-file "." "config-dir" #:recursive? #t)
15670 The effect here is to import all of the current directory into the
15671 store, and to refer to @file{config.scm} within that directory.
15672 Therefore, uses of @code{local-file} within @file{config.scm} will work
15673 as expected. @xref{G-Expressions}, for information about
15674 @code{local-file} and @code{file-append}.
15676 @item @code{services-to-restart} (default: @code{'(mcron)})
15677 This field specifies the Shepherd services to restart when the upgrade
15680 Those services are restarted right away upon completion, as with
15681 @command{herd restart}, which ensures that the latest version is
15682 running---remember that by default @command{guix system reconfigure}
15683 only restarts services that are not currently running, which is
15684 conservative: it minimizes disruption but leaves outdated services
15687 By default, the @code{mcron} service is restarted. This ensures that
15688 the latest version of the unattended upgrade job will be used next time.
15690 @item @code{system-expiration} (default: @code{(* 3 30 24 3600)})
15691 This is the expiration time in seconds for system generations. System
15692 generations older that this amount of time are deleted with
15693 @command{guix system delete-generations} when an upgrade completes.
15696 The unattended upgrade service does not run the garbage collector. You
15697 will probably want to set up your own mcron job to run @command{guix gc}
15701 @item @code{maximum-duration} (default: @code{3600})
15702 Maximum duration in seconds for the upgrade; past that time, the upgrade
15705 This is primarily useful to ensure the upgrade does not end up
15706 rebuilding or re-downloading ``the world''.
15708 @item @code{log-file} (default: @code{"/var/log/unattended-upgrade.log"})
15709 File where unattended upgrades are logged.
15714 @subsection X Window
15717 @cindex X Window System
15718 @cindex login manager
15719 Support for the X Window graphical display system---specifically
15720 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
15721 there is no @code{xorg-service} procedure. Instead, the X server is
15722 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
15725 @cindex GNOME, login manager
15726 GDM of course allows users to log in into window managers and desktop
15727 environments other than GNOME; for those using GNOME, GDM is required for
15728 features such as automatic screen locking.
15730 @cindex window manager
15731 To use X11, you must install at least one @dfn{window manager}---for
15732 example the @code{windowmaker} or @code{openbox} packages---preferably
15733 by adding it to the @code{packages} field of your operating system
15734 definition (@pxref{operating-system Reference, system-wide packages}).
15736 @defvr {Scheme Variable} gdm-service-type
15737 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
15738 Desktop Manager} (GDM), a program that manages graphical display servers and
15739 handles graphical user logins. Its value must be a @code{gdm-configuration}
15742 @cindex session types (X11)
15743 @cindex X11 session types
15744 GDM looks for @dfn{session types} described by the @file{.desktop} files in
15745 @file{/run/current-system/profile/share/xsessions} and allows users to choose
15746 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
15747 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
15748 set of packages automatically makes them available at the log-in screen.
15750 In addition, @file{~/.xsession} files are honored. When available,
15751 @file{~/.xsession} must be an executable that starts a window manager
15752 and/or other X clients.
15755 @deftp {Data Type} gdm-configuration
15757 @item @code{auto-login?} (default: @code{#f})
15758 @itemx @code{default-user} (default: @code{#f})
15759 When @code{auto-login?} is false, GDM presents a log-in screen.
15761 When @code{auto-login?} is true, GDM logs in directly as
15762 @code{default-user}.
15764 @item @code{debug?} (default: @code{#f})
15765 When true, GDM writes debug messages to its log.
15767 @item @code{gnome-shell-assets} (default: ...)
15768 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
15770 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
15771 Configuration of the Xorg graphical server.
15773 @item @code{xsession} (default: @code{(xinitrc)})
15774 Script to run before starting a X session.
15776 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
15777 File name of the @code{dbus-daemon} executable.
15779 @item @code{gdm} (default: @code{gdm})
15780 The GDM package to use.
15784 @defvr {Scheme Variable} slim-service-type
15785 This is the type for the SLiM graphical login manager for X11.
15787 Like GDM, SLiM looks for session types described by @file{.desktop} files and
15788 allows users to choose a session from the log-in screen using @kbd{F1}. It
15789 also honors @file{~/.xsession} files.
15791 Unlike GDM, SLiM does not spawn the user session on a different VT after
15792 logging in, which means that you can only start one graphical session. If you
15793 want to be able to run multiple graphical sessions at the same time you have
15794 to add multiple SLiM services to your system services. The following example
15795 shows how to replace the default GDM service with two SLiM services on tty7
15799 (use-modules (gnu services)
15800 (gnu services desktop)
15801 (gnu services xorg)
15802 (srfi srfi-1)) ;for 'remove'
15806 (services (cons* (service slim-service-type (slim-configuration
15809 (service slim-service-type (slim-configuration
15812 (remove (lambda (service)
15813 (eq? (service-kind service) gdm-service-type))
15814 %desktop-services))))
15819 @deftp {Data Type} slim-configuration
15820 Data type representing the configuration of @code{slim-service-type}.
15823 @item @code{allow-empty-passwords?} (default: @code{#t})
15824 Whether to allow logins with empty passwords.
15826 @item @code{auto-login?} (default: @code{#f})
15827 @itemx @code{default-user} (default: @code{""})
15828 When @code{auto-login?} is false, SLiM presents a log-in screen.
15830 When @code{auto-login?} is true, SLiM logs in directly as
15831 @code{default-user}.
15833 @item @code{theme} (default: @code{%default-slim-theme})
15834 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
15835 The graphical theme to use and its name.
15837 @item @code{auto-login-session} (default: @code{#f})
15838 If true, this must be the name of the executable to start as the default
15839 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
15841 If false, a session described by one of the available @file{.desktop}
15842 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
15846 You must install at least one window manager in the system profile or in
15847 your user profile. Failing to do that, if @code{auto-login-session} is
15848 false, you will be unable to log in.
15851 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
15852 Configuration of the Xorg graphical server.
15854 @item @code{display} (default @code{":0"})
15855 The display on which to start the Xorg graphical server.
15857 @item @code{vt} (default @code{"vt7"})
15858 The VT on which to start the Xorg graphical server.
15860 @item @code{xauth} (default: @code{xauth})
15861 The XAuth package to use.
15863 @item @code{shepherd} (default: @code{shepherd})
15864 The Shepherd package used when invoking @command{halt} and
15867 @item @code{sessreg} (default: @code{sessreg})
15868 The sessreg package used in order to register the session.
15870 @item @code{slim} (default: @code{slim})
15871 The SLiM package to use.
15875 @defvr {Scheme Variable} %default-theme
15876 @defvrx {Scheme Variable} %default-theme-name
15877 The default SLiM theme and its name.
15881 @deftp {Data Type} sddm-configuration
15882 This is the data type representing the SDDM service configuration.
15885 @item @code{display-server} (default: "x11")
15886 Select display server to use for the greeter. Valid values are
15887 @samp{"x11"} or @samp{"wayland"}.
15889 @item @code{numlock} (default: "on")
15890 Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
15892 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
15893 Command to run when halting.
15895 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
15896 Command to run when rebooting.
15898 @item @code{theme} (default "maldives")
15899 Theme to use. Default themes provided by SDDM are @samp{"elarun"},
15900 @samp{"maldives"} or @samp{"maya"}.
15902 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
15903 Directory to look for themes.
15905 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
15906 Directory to look for faces.
15908 @item @code{default-path} (default "/run/current-system/profile/bin")
15909 Default PATH to use.
15911 @item @code{minimum-uid} (default: 1000)
15912 Minimum UID displayed in SDDM and allowed for log-in.
15914 @item @code{maximum-uid} (default: 2000)
15915 Maximum UID to display in SDDM.
15917 @item @code{remember-last-user?} (default #t)
15918 Remember last user.
15920 @item @code{remember-last-session?} (default #t)
15921 Remember last session.
15923 @item @code{hide-users} (default "")
15924 Usernames to hide from SDDM greeter.
15926 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
15927 Users with shells listed will be hidden from the SDDM greeter.
15929 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
15930 Script to run before starting a wayland session.
15932 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
15933 Directory to look for desktop files starting wayland sessions.
15935 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
15936 Configuration of the Xorg graphical server.
15938 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
15941 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
15944 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
15945 Script to run after starting xorg-server.
15947 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
15948 Script to run before stopping xorg-server.
15950 @item @code{xsession-command} (default: @code{xinitrc})
15951 Script to run before starting a X session.
15953 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
15954 Directory to look for desktop files starting X sessions.
15956 @item @code{minimum-vt} (default: 7)
15959 @item @code{auto-login-user} (default "")
15960 User to use for auto-login.
15962 @item @code{auto-login-session} (default "")
15963 Desktop file to use for auto-login.
15965 @item @code{relogin?} (default #f)
15966 Relogin after logout.
15971 @cindex login manager
15973 @defvr {Scheme Variable} sddm-service-type
15974 This is the type of the service to run the
15975 @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
15976 must be a @code{sddm-configuration} record (see below).
15978 Here's an example use:
15981 (service sddm-service-type
15982 (sddm-configuration
15983 (auto-login-user "alice")
15984 (auto-login-session "xfce.desktop")))
15988 @deftp {Data Type} sddm-configuration
15989 This data type represents the configuration of the SDDM login manager.
15990 The available fields are:
15993 @item @code{sddm} (default: @code{sddm})
15994 The SDDM package to use.
15996 @item @code{display-server} (default: @code{"x11"})
15997 This must be either @code{"x11"} or @code{"wayland"}.
15999 @c FIXME: Add more fields.
16001 @item @code{auto-login-user} (default: @code{""})
16002 If non-empty, this is the user account under which to log in
16005 @item @code{auto-login-session} (default: @code{""})
16006 If non-empty, this is the @file{.desktop} file name to use as the
16007 auto-login session.
16011 @cindex Xorg, configuration
16012 @deftp {Data Type} xorg-configuration
16013 This data type represents the configuration of the Xorg graphical display
16014 server. Note that there is no Xorg service; instead, the X server is started
16015 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
16016 of these display managers aggregates an @code{xorg-configuration} record.
16019 @item @code{modules} (default: @code{%default-xorg-modules})
16020 This is a list of @dfn{module packages} loaded by the Xorg
16021 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
16023 @item @code{fonts} (default: @code{%default-xorg-fonts})
16024 This is a list of font directories to add to the server's @dfn{font path}.
16026 @item @code{drivers} (default: @code{'()})
16027 This must be either the empty list, in which case Xorg chooses a graphics
16028 driver automatically, or a list of driver names that will be tried in this
16029 order---e.g., @code{("modesetting" "vesa")}.
16031 @item @code{resolutions} (default: @code{'()})
16032 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
16033 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
16036 @cindex keyboard layout, for Xorg
16037 @cindex keymap, for Xorg
16038 @item @code{keyboard-layout} (default: @code{#f})
16039 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
16040 English (``qwerty'') for a 105-key PC keyboard.
16042 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
16043 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
16044 information on how to specify the keyboard layout.
16046 @item @code{extra-config} (default: @code{'()})
16047 This is a list of strings or objects appended to the configuration file. It
16048 is used to pass extra text to be added verbatim to the configuration file.
16050 @item @code{server} (default: @code{xorg-server})
16051 This is the package providing the Xorg server.
16053 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
16054 This is the list of command-line arguments to pass to the X server. The
16055 default is @code{-nolisten tcp}.
16059 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
16060 [@var{login-manager-service-type}]
16061 Tell the log-in manager (of type @var{login-manager-service-type}) to use
16062 @var{config}, an @code{<xorg-configuration>} record.
16064 Since the Xorg configuration is embedded in the log-in manager's
16065 configuration---e.g., @code{gdm-configuration}---this procedure provides a
16066 shorthand to set the Xorg configuration.
16069 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
16070 Return a @code{startx} script in which the modules, fonts, etc. specified
16071 in @var{config}, are available. The result should be used in place of
16074 Usually the X server is started by a login manager.
16078 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
16079 Add @var{package}, a package for a screen locker or screen saver whose
16080 command is @var{program}, to the set of setuid programs and add a PAM entry
16081 for it. For example:
16084 (screen-locker-service xlockmore "xlock")
16087 makes the good ol' XlockMore usable.
16091 @node Printing Services
16092 @subsection Printing Services
16094 @cindex printer support with CUPS
16095 The @code{(gnu services cups)} module provides a Guix service definition
16096 for the CUPS printing service. To add printer support to a Guix
16097 system, add a @code{cups-service} to the operating system definition:
16099 @deffn {Scheme Variable} cups-service-type
16100 The service type for the CUPS print server. Its value should be a valid
16101 CUPS configuration (see below). To use the default settings, simply
16104 (service cups-service-type)
16108 The CUPS configuration controls the basic things about your CUPS
16109 installation: what interfaces it listens on, what to do if a print job
16110 fails, how much logging to do, and so on. To actually add a printer,
16111 you have to visit the @url{http://localhost:631} URL, or use a tool such
16112 as GNOME's printer configuration services. By default, configuring a
16113 CUPS service will generate a self-signed certificate if needed, for
16114 secure connections to the print server.
16116 Suppose you want to enable the Web interface of CUPS and also add
16117 support for Epson printers @i{via} the @code{escpr} package and for HP
16118 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
16119 like this (you need to use the @code{(gnu packages cups)} module):
16122 (service cups-service-type
16123 (cups-configuration
16124 (web-interface? #t)
16126 (list cups-filters escpr hplip-minimal))))
16129 Note: If you wish to use the Qt5 based GUI which comes with the hplip
16130 package then it is suggested that you install the @code{hplip} package,
16131 either in your OS configuration file or as your user.
16133 The available configuration parameters follow. Each parameter
16134 definition is preceded by its type; for example, @samp{string-list foo}
16135 indicates that the @code{foo} parameter should be specified as a list of
16136 strings. There is also a way to specify the configuration as a string,
16137 if you have an old @code{cupsd.conf} file that you want to port over
16138 from some other system; see the end for more details.
16140 @c The following documentation was initially generated by
16141 @c (generate-documentation) in (gnu services cups). Manually maintained
16142 @c documentation is better, so we shouldn't hesitate to edit below as
16143 @c needed. However if the change you want to make to this documentation
16144 @c can be done in an automated way, it's probably easier to change
16145 @c (generate-documentation) than to make it below and have to deal with
16146 @c the churn as CUPS updates.
16149 Available @code{cups-configuration} fields are:
16151 @deftypevr {@code{cups-configuration} parameter} package cups
16155 @deftypevr {@code{cups-configuration} parameter} package-list extensions
16156 Drivers and other extensions to the CUPS package.
16159 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
16160 Configuration of where to write logs, what directories to use for print
16161 spools, and related privileged configuration parameters.
16163 Available @code{files-configuration} fields are:
16165 @deftypevr {@code{files-configuration} parameter} log-location access-log
16166 Defines the access log filename. Specifying a blank filename disables
16167 access log generation. The value @code{stderr} causes log entries to be
16168 sent to the standard error file when the scheduler is running in the
16169 foreground, or to the system log daemon when run in the background. The
16170 value @code{syslog} causes log entries to be sent to the system log
16171 daemon. The server name may be included in filenames using the string
16172 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
16174 Defaults to @samp{"/var/log/cups/access_log"}.
16177 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
16178 Where CUPS should cache data.
16180 Defaults to @samp{"/var/cache/cups"}.
16183 @deftypevr {@code{files-configuration} parameter} string config-file-perm
16184 Specifies the permissions for all configuration files that the scheduler
16187 Note that the permissions for the printers.conf file are currently
16188 masked to only allow access from the scheduler user (typically root).
16189 This is done because printer device URIs sometimes contain sensitive
16190 authentication information that should not be generally known on the
16191 system. There is no way to disable this security feature.
16193 Defaults to @samp{"0640"}.
16196 @deftypevr {@code{files-configuration} parameter} log-location error-log
16197 Defines the error log filename. Specifying a blank filename disables
16198 error log generation. The value @code{stderr} causes log entries to be
16199 sent to the standard error file when the scheduler is running in the
16200 foreground, or to the system log daemon when run in the background. The
16201 value @code{syslog} causes log entries to be sent to the system log
16202 daemon. The server name may be included in filenames using the string
16203 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
16205 Defaults to @samp{"/var/log/cups/error_log"}.
16208 @deftypevr {@code{files-configuration} parameter} string fatal-errors
16209 Specifies which errors are fatal, causing the scheduler to exit. The
16214 No errors are fatal.
16217 All of the errors below are fatal.
16220 Browsing initialization errors are fatal, for example failed connections
16221 to the DNS-SD daemon.
16224 Configuration file syntax errors are fatal.
16227 Listen or Port errors are fatal, except for IPv6 failures on the
16228 loopback or @code{any} addresses.
16231 Log file creation or write errors are fatal.
16234 Bad startup file permissions are fatal, for example shared TLS
16235 certificate and key files with world-read permissions.
16238 Defaults to @samp{"all -browse"}.
16241 @deftypevr {@code{files-configuration} parameter} boolean file-device?
16242 Specifies whether the file pseudo-device can be used for new printer
16243 queues. The URI @uref{file:///dev/null} is always allowed.
16245 Defaults to @samp{#f}.
16248 @deftypevr {@code{files-configuration} parameter} string group
16249 Specifies the group name or ID that will be used when executing external
16252 Defaults to @samp{"lp"}.
16255 @deftypevr {@code{files-configuration} parameter} string log-file-perm
16256 Specifies the permissions for all log files that the scheduler writes.
16258 Defaults to @samp{"0644"}.
16261 @deftypevr {@code{files-configuration} parameter} log-location page-log
16262 Defines the page log filename. Specifying a blank filename disables
16263 page log generation. The value @code{stderr} causes log entries to be
16264 sent to the standard error file when the scheduler is running in the
16265 foreground, or to the system log daemon when run in the background. The
16266 value @code{syslog} causes log entries to be sent to the system log
16267 daemon. The server name may be included in filenames using the string
16268 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
16270 Defaults to @samp{"/var/log/cups/page_log"}.
16273 @deftypevr {@code{files-configuration} parameter} string remote-root
16274 Specifies the username that is associated with unauthenticated accesses
16275 by clients claiming to be the root user. The default is @code{remroot}.
16277 Defaults to @samp{"remroot"}.
16280 @deftypevr {@code{files-configuration} parameter} file-name request-root
16281 Specifies the directory that contains print jobs and other HTTP request
16284 Defaults to @samp{"/var/spool/cups"}.
16287 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
16288 Specifies the level of security sandboxing that is applied to print
16289 filters, backends, and other child processes of the scheduler; either
16290 @code{relaxed} or @code{strict}. This directive is currently only
16291 used/supported on macOS.
16293 Defaults to @samp{strict}.
16296 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
16297 Specifies the location of TLS certificates and private keys. CUPS will
16298 look for public and private keys in this directory: @file{.crt} files
16299 for PEM-encoded certificates and corresponding @file{.key} files for
16300 PEM-encoded private keys.
16302 Defaults to @samp{"/etc/cups/ssl"}.
16305 @deftypevr {@code{files-configuration} parameter} file-name server-root
16306 Specifies the directory containing the server configuration files.
16308 Defaults to @samp{"/etc/cups"}.
16311 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
16312 Specifies whether the scheduler calls fsync(2) after writing
16313 configuration or state files.
16315 Defaults to @samp{#f}.
16318 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
16319 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
16322 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
16323 Specifies the directory where temporary files are stored.
16325 Defaults to @samp{"/var/spool/cups/tmp"}.
16328 @deftypevr {@code{files-configuration} parameter} string user
16329 Specifies the user name or ID that is used when running external
16332 Defaults to @samp{"lp"}.
16335 @deftypevr {@code{files-configuration} parameter} string set-env
16336 Set the specified environment variable to be passed to child processes.
16338 Defaults to @samp{"variable value"}.
16342 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
16343 Specifies the logging level for the AccessLog file. The @code{config}
16344 level logs when printers and classes are added, deleted, or modified and
16345 when configuration files are accessed or updated. The @code{actions}
16346 level logs when print jobs are submitted, held, released, modified, or
16347 canceled, and any of the conditions for @code{config}. The @code{all}
16348 level logs all requests.
16350 Defaults to @samp{actions}.
16353 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
16354 Specifies whether to purge job history data automatically when it is no
16355 longer required for quotas.
16357 Defaults to @samp{#f}.
16360 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
16361 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
16362 For example, @samp{"_cups" "_print"} will tell network clients that both
16363 CUPS sharing and IPP Everywhere are supported.
16365 Defaults to @samp{"_cups"}.
16368 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
16369 Specifies which protocols to use for local printer sharing.
16371 Defaults to @samp{dnssd}.
16374 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
16375 Specifies whether the CUPS web interface is advertised.
16377 Defaults to @samp{#f}.
16380 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
16381 Specifies whether shared printers are advertised.
16383 Defaults to @samp{#f}.
16386 @deftypevr {@code{cups-configuration} parameter} string classification
16387 Specifies the security classification of the server. Any valid banner
16388 name can be used, including @samp{"classified"}, @samp{"confidential"},
16389 @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
16390 banner can be omitted to disable secure printing functions.
16392 Defaults to @samp{""}.
16395 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
16396 Specifies whether users may override the classification (cover page) of
16397 individual print jobs using the @code{job-sheets} option.
16399 Defaults to @samp{#f}.
16402 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
16403 Specifies the default type of authentication to use.
16405 Defaults to @samp{Basic}.
16408 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
16409 Specifies whether encryption will be used for authenticated requests.
16411 Defaults to @samp{Required}.
16414 @deftypevr {@code{cups-configuration} parameter} string default-language
16415 Specifies the default language to use for text and web content.
16417 Defaults to @samp{"en"}.
16420 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
16421 Specifies the default paper size for new print queues. @samp{"Auto"}
16422 uses a locale-specific default, while @samp{"None"} specifies there is
16423 no default paper size. Specific size names are typically
16424 @samp{"Letter"} or @samp{"A4"}.
16426 Defaults to @samp{"Auto"}.
16429 @deftypevr {@code{cups-configuration} parameter} string default-policy
16430 Specifies the default access policy to use.
16432 Defaults to @samp{"default"}.
16435 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
16436 Specifies whether local printers are shared by default.
16438 Defaults to @samp{#t}.
16441 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
16442 Specifies the delay for updating of configuration and state files, in
16443 seconds. A value of 0 causes the update to happen as soon as possible,
16444 typically within a few milliseconds.
16446 Defaults to @samp{30}.
16449 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
16450 Specifies what to do when an error occurs. Possible values are
16451 @code{abort-job}, which will discard the failed print job;
16452 @code{retry-job}, which will retry the job at a later time;
16453 @code{retry-current-job}, which retries the failed job immediately; and
16454 @code{stop-printer}, which stops the printer.
16456 Defaults to @samp{stop-printer}.
16459 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
16460 Specifies the maximum cost of filters that are run concurrently, which
16461 can be used to minimize disk, memory, and CPU resource problems. A
16462 limit of 0 disables filter limiting. An average print to a
16463 non-PostScript printer needs a filter limit of about 200. A PostScript
16464 printer needs about half that (100). Setting the limit below these
16465 thresholds will effectively limit the scheduler to printing a single job
16468 Defaults to @samp{0}.
16471 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
16472 Specifies the scheduling priority of filters that are run to print a
16473 job. The nice value ranges from 0, the highest priority, to 19, the
16476 Defaults to @samp{0}.
16479 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
16480 Specifies whether to do reverse lookups on connecting clients. The
16481 @code{double} setting causes @code{cupsd} to verify that the hostname
16482 resolved from the address matches one of the addresses returned for that
16483 hostname. Double lookups also prevent clients with unregistered
16484 addresses from connecting to your server. Only set this option to
16485 @code{#t} or @code{double} if absolutely required.
16487 Defaults to @samp{#f}.
16490 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
16491 Specifies the number of seconds to wait before killing the filters and
16492 backend associated with a canceled or held job.
16494 Defaults to @samp{30}.
16497 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
16498 Specifies the interval between retries of jobs in seconds. This is
16499 typically used for fax queues but can also be used with normal print
16500 queues whose error policy is @code{retry-job} or
16501 @code{retry-current-job}.
16503 Defaults to @samp{30}.
16506 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
16507 Specifies the number of retries that are done for jobs. This is
16508 typically used for fax queues but can also be used with normal print
16509 queues whose error policy is @code{retry-job} or
16510 @code{retry-current-job}.
16512 Defaults to @samp{5}.
16515 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
16516 Specifies whether to support HTTP keep-alive connections.
16518 Defaults to @samp{#t}.
16521 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
16522 Specifies how long an idle client connection remains open, in seconds.
16524 Defaults to @samp{30}.
16527 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
16528 Specifies the maximum size of print files, IPP requests, and HTML form
16529 data. A limit of 0 disables the limit check.
16531 Defaults to @samp{0}.
16534 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
16535 Listens on the specified interfaces for connections. Valid values are
16536 of the form @var{address}:@var{port}, where @var{address} is either an
16537 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
16538 indicate all addresses. Values can also be file names of local UNIX
16539 domain sockets. The Listen directive is similar to the Port directive
16540 but allows you to restrict access to specific interfaces or networks.
16543 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
16544 Specifies the number of pending connections that will be allowed. This
16545 normally only affects very busy servers that have reached the MaxClients
16546 limit, but can also be triggered by large numbers of simultaneous
16547 connections. When the limit is reached, the operating system will
16548 refuse additional connections until the scheduler can accept the pending
16551 Defaults to @samp{128}.
16554 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
16555 Specifies a set of additional access controls.
16557 Available @code{location-access-controls} fields are:
16559 @deftypevr {@code{location-access-controls} parameter} file-name path
16560 Specifies the URI path to which the access control applies.
16563 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
16564 Access controls for all access to this path, in the same format as the
16565 @code{access-controls} of @code{operation-access-control}.
16567 Defaults to @samp{()}.
16570 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
16571 Access controls for method-specific access to this path.
16573 Defaults to @samp{()}.
16575 Available @code{method-access-controls} fields are:
16577 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
16578 If @code{#t}, apply access controls to all methods except the listed
16579 methods. Otherwise apply to only the listed methods.
16581 Defaults to @samp{#f}.
16584 @deftypevr {@code{method-access-controls} parameter} method-list methods
16585 Methods to which this access control applies.
16587 Defaults to @samp{()}.
16590 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
16591 Access control directives, as a list of strings. Each string should be
16592 one directive, such as @samp{"Order allow,deny"}.
16594 Defaults to @samp{()}.
16599 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
16600 Specifies the number of debugging messages that are retained for logging
16601 if an error occurs in a print job. Debug messages are logged regardless
16602 of the LogLevel setting.
16604 Defaults to @samp{100}.
16607 @deftypevr {@code{cups-configuration} parameter} log-level log-level
16608 Specifies the level of logging for the ErrorLog file. The value
16609 @code{none} stops all logging while @code{debug2} logs everything.
16611 Defaults to @samp{info}.
16614 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
16615 Specifies the format of the date and time in the log files. The value
16616 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
16618 Defaults to @samp{standard}.
16621 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
16622 Specifies the maximum number of simultaneous clients that are allowed by
16625 Defaults to @samp{100}.
16628 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
16629 Specifies the maximum number of simultaneous clients that are allowed
16630 from a single address.
16632 Defaults to @samp{100}.
16635 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
16636 Specifies the maximum number of copies that a user can print of each
16639 Defaults to @samp{9999}.
16642 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
16643 Specifies the maximum time a job may remain in the @code{indefinite}
16644 hold state before it is canceled. A value of 0 disables cancellation of
16647 Defaults to @samp{0}.
16650 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
16651 Specifies the maximum number of simultaneous jobs that are allowed. Set
16652 to 0 to allow an unlimited number of jobs.
16654 Defaults to @samp{500}.
16657 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
16658 Specifies the maximum number of simultaneous jobs that are allowed per
16659 printer. A value of 0 allows up to MaxJobs jobs per printer.
16661 Defaults to @samp{0}.
16664 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
16665 Specifies the maximum number of simultaneous jobs that are allowed per
16666 user. A value of 0 allows up to MaxJobs jobs per user.
16668 Defaults to @samp{0}.
16671 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
16672 Specifies the maximum time a job may take to print before it is
16673 canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
16675 Defaults to @samp{10800}.
16678 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
16679 Specifies the maximum size of the log files before they are rotated, in
16680 bytes. The value 0 disables log rotation.
16682 Defaults to @samp{1048576}.
16685 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
16686 Specifies the maximum amount of time to allow between files in a
16687 multiple file print job, in seconds.
16689 Defaults to @samp{300}.
16692 @deftypevr {@code{cups-configuration} parameter} string page-log-format
16693 Specifies the format of PageLog lines. Sequences beginning with percent
16694 (@samp{%}) characters are replaced with the corresponding information,
16695 while all other characters are copied literally. The following percent
16696 sequences are recognized:
16700 insert a single percent character
16703 insert the value of the specified IPP attribute
16706 insert the number of copies for the current page
16709 insert the current page number
16712 insert the current date and time in common log format
16718 insert the printer name
16721 insert the username
16724 A value of the empty string disables page logging. The string @code{%p
16725 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
16726 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
16729 Defaults to @samp{""}.
16732 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
16733 Passes the specified environment variable(s) to child processes; a list
16736 Defaults to @samp{()}.
16739 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
16740 Specifies named access control policies.
16742 Available @code{policy-configuration} fields are:
16744 @deftypevr {@code{policy-configuration} parameter} string name
16745 Name of the policy.
16748 @deftypevr {@code{policy-configuration} parameter} string job-private-access
16749 Specifies an access list for a job's private values. @code{@@ACL} maps
16750 to the printer's requesting-user-name-allowed or
16751 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
16752 owner. @code{@@SYSTEM} maps to the groups listed for the
16753 @code{system-group} field of the @code{files-config} configuration,
16754 which is reified into the @code{cups-files.conf(5)} file. Other
16755 possible elements of the access list include specific user names, and
16756 @code{@@@var{group}} to indicate members of a specific group. The
16757 access list may also be simply @code{all} or @code{default}.
16759 Defaults to @samp{"@@OWNER @@SYSTEM"}.
16762 @deftypevr {@code{policy-configuration} parameter} string job-private-values
16763 Specifies the list of job values to make private, or @code{all},
16764 @code{default}, or @code{none}.
16766 Defaults to @samp{"job-name job-originating-host-name
16767 job-originating-user-name phone"}.
16770 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
16771 Specifies an access list for a subscription's private values.
16772 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
16773 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
16774 owner. @code{@@SYSTEM} maps to the groups listed for the
16775 @code{system-group} field of the @code{files-config} configuration,
16776 which is reified into the @code{cups-files.conf(5)} file. Other
16777 possible elements of the access list include specific user names, and
16778 @code{@@@var{group}} to indicate members of a specific group. The
16779 access list may also be simply @code{all} or @code{default}.
16781 Defaults to @samp{"@@OWNER @@SYSTEM"}.
16784 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
16785 Specifies the list of job values to make private, or @code{all},
16786 @code{default}, or @code{none}.
16788 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
16789 notify-subscriber-user-name notify-user-data"}.
16792 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
16793 Access control by IPP operation.
16795 Defaults to @samp{()}.
16799 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
16800 Specifies whether job files (documents) are preserved after a job is
16801 printed. If a numeric value is specified, job files are preserved for
16802 the indicated number of seconds after printing. Otherwise a boolean
16803 value applies indefinitely.
16805 Defaults to @samp{86400}.
16808 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
16809 Specifies whether the job history is preserved after a job is printed.
16810 If a numeric value is specified, the job history is preserved for the
16811 indicated number of seconds after printing. If @code{#t}, the job
16812 history is preserved until the MaxJobs limit is reached.
16814 Defaults to @samp{#t}.
16817 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
16818 Specifies the amount of time to wait for job completion before
16819 restarting the scheduler.
16821 Defaults to @samp{30}.
16824 @deftypevr {@code{cups-configuration} parameter} string rip-cache
16825 Specifies the maximum amount of memory to use when converting documents
16826 into bitmaps for a printer.
16828 Defaults to @samp{"128m"}.
16831 @deftypevr {@code{cups-configuration} parameter} string server-admin
16832 Specifies the email address of the server administrator.
16834 Defaults to @samp{"root@@localhost.localdomain"}.
16837 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
16838 The ServerAlias directive is used for HTTP Host header validation when
16839 clients connect to the scheduler from external interfaces. Using the
16840 special name @code{*} can expose your system to known browser-based DNS
16841 rebinding attacks, even when accessing sites through a firewall. If the
16842 auto-discovery of alternate names does not work, we recommend listing
16843 each alternate name with a ServerAlias directive instead of using
16846 Defaults to @samp{*}.
16849 @deftypevr {@code{cups-configuration} parameter} string server-name
16850 Specifies the fully-qualified host name of the server.
16852 Defaults to @samp{"localhost"}.
16855 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
16856 Specifies what information is included in the Server header of HTTP
16857 responses. @code{None} disables the Server header. @code{ProductOnly}
16858 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
16859 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
16860 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
16861 the output of the @code{uname} command. @code{Full} reports @code{CUPS
16862 2.0.0 (@var{uname}) IPP/2.0}.
16864 Defaults to @samp{Minimal}.
16867 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
16868 Listens on the specified interfaces for encrypted connections. Valid
16869 values are of the form @var{address}:@var{port}, where @var{address} is
16870 either an IPv6 address enclosed in brackets, an IPv4 address, or
16871 @code{*} to indicate all addresses.
16873 Defaults to @samp{()}.
16876 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
16877 Sets encryption options. By default, CUPS only supports encryption
16878 using TLS v1.0 or higher using known secure cipher suites. Security is
16879 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
16880 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
16881 suites, which are required for some older clients. The @code{AllowSSL3} option
16882 enables SSL v3.0, which is required for some older clients that do not support
16883 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
16884 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
16885 protocol version to TLS v1.1.
16887 Defaults to @samp{()}.
16890 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
16891 Specifies whether the scheduler requires clients to strictly adhere to
16892 the IPP specifications.
16894 Defaults to @samp{#f}.
16897 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
16898 Specifies the HTTP request timeout, in seconds.
16900 Defaults to @samp{300}.
16904 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
16905 Specifies whether the web interface is enabled.
16907 Defaults to @samp{#f}.
16910 At this point you're probably thinking ``oh dear, Guix manual, I like
16911 you but you can stop already with the configuration options''. Indeed.
16912 However, one more point: it could be that you have an existing
16913 @code{cupsd.conf} that you want to use. In that case, you can pass an
16914 @code{opaque-cups-configuration} as the configuration of a
16915 @code{cups-service-type}.
16917 Available @code{opaque-cups-configuration} fields are:
16919 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
16923 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
16924 The contents of the @code{cupsd.conf}, as a string.
16927 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
16928 The contents of the @code{cups-files.conf} file, as a string.
16931 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
16932 strings of the same name, you could instantiate a CUPS service like
16936 (service cups-service-type
16937 (opaque-cups-configuration
16938 (cupsd.conf cupsd.conf)
16939 (cups-files.conf cups-files.conf)))
16943 @node Desktop Services
16944 @subsection Desktop Services
16946 The @code{(gnu services desktop)} module provides services that are
16947 usually useful in the context of a ``desktop'' setup---that is, on a
16948 machine running a graphical display server, possibly with graphical user
16949 interfaces, etc. It also defines services that provide specific desktop
16950 environments like GNOME, Xfce or MATE.
16952 To simplify things, the module defines a variable containing the set of
16953 services that users typically expect on a machine with a graphical
16954 environment and networking:
16956 @defvr {Scheme Variable} %desktop-services
16957 This is a list of services that builds upon @code{%base-services} and
16958 adds or adjusts services for a typical ``desktop'' setup.
16960 In particular, it adds a graphical login manager (@pxref{X Window,
16961 @code{gdm-service-type}}), screen lockers, a network management tool
16962 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
16963 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
16964 energy and color management services, the @code{elogind} login and seat
16965 manager, the Polkit privilege service, the GeoClue location service, the
16966 AccountsService daemon that allows authorized users change system passwords,
16967 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
16968 name service switch service configured to be able to use @code{nss-mdns}
16969 (@pxref{Name Service Switch, mDNS}).
16972 The @code{%desktop-services} variable can be used as the @code{services}
16973 field of an @code{operating-system} declaration (@pxref{operating-system
16974 Reference, @code{services}}).
16976 Additionally, the @code{gnome-desktop-service-type},
16977 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
16978 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
16979 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
16980 services like the backlight adjustment helpers and the power management
16981 utilities are added to the system, extending @code{polkit} and @code{dbus}
16982 appropriately, allowing GNOME to operate with elevated privileges on a
16983 limited number of special-purpose system interfaces. Additionally,
16984 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
16985 metapackage to the system profile. Likewise, adding the Xfce service
16986 not only adds the @code{xfce} metapackage to the system profile, but it
16987 also gives the Thunar file manager the ability to open a ``root-mode''
16988 file management window, if the user authenticates using the
16989 administrator's password via the standard polkit graphical interface.
16990 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
16991 appropriately, allowing MATE to operate with elevated privileges on a
16992 limited number of special-purpose system interfaces. Additionally,
16993 adding a service of type @code{mate-desktop-service-type} adds the MATE
16994 metapackage to the system profile. ``Adding Enlightenment'' means that
16995 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
16996 are set as setuid, allowing Enlightenment's screen locker and other
16997 functionality to work as expected.
16999 The desktop environments in Guix use the Xorg display server by
17000 default. If you'd like to use the newer display server protocol
17001 called Wayland, you need to use the @code{sddm-service} instead of
17002 GDM as the graphical login manager. You should then
17003 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
17004 also try starting GNOME on Wayland manually from a TTY with the
17005 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
17006 gnome-session``. Currently only GNOME has support for Wayland.
17008 @defvr {Scheme Variable} gnome-desktop-service-type
17009 This is the type of the service that adds the @uref{https://www.gnome.org,
17010 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
17011 object (see below).
17013 This service adds the @code{gnome} package to the system profile, and extends
17014 polkit with the actions from @code{gnome-settings-daemon}.
17017 @deftp {Data Type} gnome-desktop-configuration
17018 Configuration record for the GNOME desktop environment.
17021 @item @code{gnome} (default: @code{gnome})
17022 The GNOME package to use.
17026 @defvr {Scheme Variable} xfce-desktop-service-type
17027 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
17028 desktop environment. Its value is an @code{xfce-desktop-configuration} object
17031 This service adds the @code{xfce} package to the system profile, and
17032 extends polkit with the ability for @code{thunar} to manipulate the file
17033 system as root from within a user session, after the user has authenticated
17034 with the administrator's password.
17037 @deftp {Data Type} xfce-desktop-configuration
17038 Configuration record for the Xfce desktop environment.
17041 @item @code{xfce} (default: @code{xfce})
17042 The Xfce package to use.
17046 @deffn {Scheme Variable} mate-desktop-service-type
17047 This is the type of the service that runs the @uref{https://mate-desktop.org/,
17048 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
17049 object (see below).
17051 This service adds the @code{mate} package to the system
17052 profile, and extends polkit with the actions from
17053 @code{mate-settings-daemon}.
17056 @deftp {Data Type} mate-desktop-configuration
17057 Configuration record for the MATE desktop environment.
17060 @item @code{mate} (default: @code{mate})
17061 The MATE package to use.
17065 @deffn {Scheme Variable} enlightenment-desktop-service-type
17066 Return a service that adds the @code{enlightenment} package to the system
17067 profile, and extends dbus with actions from @code{efl}.
17070 @deftp {Data Type} enlightenment-desktop-service-configuration
17072 @item @code{enlightenment} (default: @code{enlightenment})
17073 The enlightenment package to use.
17077 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
17078 the default @code{%desktop-services} variable doesn't include any of
17079 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
17080 @code{%desktop-services} in the @code{services} field of your
17081 @code{operating-system}:
17084 (use-modules (gnu))
17085 (use-service-modules desktop)
17088 ;; cons* adds items to the list given as its last argument.
17089 (services (cons* (service gnome-desktop-service-type)
17090 (service xfce-desktop-service)
17091 %desktop-services))
17095 These desktop environments will then be available as options in the
17096 graphical login window.
17098 The actual service definitions included in @code{%desktop-services} and
17099 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
17100 are described below.
17102 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
17103 Return a service that runs the ``system bus'', using @var{dbus}, with
17104 support for @var{services}.
17106 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
17107 facility. Its system bus is used to allow system services to communicate
17108 and to be notified of system-wide events.
17110 @var{services} must be a list of packages that provide an
17111 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
17112 and policy files. For example, to allow avahi-daemon to use the system bus,
17113 @var{services} must be equal to @code{(list avahi)}.
17116 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
17117 Return a service that runs the @code{elogind} login and
17118 seat management daemon. @uref{https://github.com/elogind/elogind,
17119 Elogind} exposes a D-Bus interface that can be used to know which users
17120 are logged in, know what kind of sessions they have open, suspend the
17121 system, inhibit system suspend, reboot the system, and other tasks.
17123 Elogind handles most system-level power events for a computer, for
17124 example suspending the system when a lid is closed, or shutting it down
17125 when the power button is pressed.
17127 The @var{config} keyword argument specifies the configuration for
17128 elogind, and should be the result of an @code{(elogind-configuration
17129 (@var{parameter} @var{value})...)} invocation. Available parameters and
17130 their default values are:
17133 @item kill-user-processes?
17135 @item kill-only-users
17137 @item kill-exclude-users
17139 @item inhibit-delay-max-seconds
17141 @item handle-power-key
17143 @item handle-suspend-key
17145 @item handle-hibernate-key
17147 @item handle-lid-switch
17149 @item handle-lid-switch-docked
17151 @item power-key-ignore-inhibited?
17153 @item suspend-key-ignore-inhibited?
17155 @item hibernate-key-ignore-inhibited?
17157 @item lid-switch-ignore-inhibited?
17159 @item holdoff-timeout-seconds
17163 @item idle-action-seconds
17165 @item runtime-directory-size-percent
17167 @item runtime-directory-size
17171 @item suspend-state
17172 @code{("mem" "standby" "freeze")}
17175 @item hibernate-state
17177 @item hibernate-mode
17178 @code{("platform" "shutdown")}
17179 @item hybrid-sleep-state
17181 @item hybrid-sleep-mode
17182 @code{("suspend" "platform" "shutdown")}
17186 @deffn {Scheme Procedure} accountsservice-service @
17187 [#:accountsservice @var{accountsservice}]
17188 Return a service that runs AccountsService, a system service that can
17189 list available accounts, change their passwords, and so on.
17190 AccountsService integrates with PolicyKit to enable unprivileged users
17191 to acquire the capability to modify their system configuration.
17192 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
17193 accountsservice web site} for more information.
17195 The @var{accountsservice} keyword argument is the @code{accountsservice}
17196 package to expose as a service.
17199 @deffn {Scheme Procedure} polkit-service @
17200 [#:polkit @var{polkit}]
17201 Return a service that runs the
17202 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
17203 management service}, which allows system administrators to grant access to
17204 privileged operations in a structured way. By querying the Polkit service, a
17205 privileged system component can know when it should grant additional
17206 capabilities to ordinary users. For example, an ordinary user can be granted
17207 the capability to suspend the system if the user is logged in locally.
17210 @defvr {Scheme Variable} polkit-wheel-service
17211 Service that adds the @code{wheel} group as admins to the Polkit
17212 service. This makes it so that users in the @code{wheel} group are queried
17213 for their own passwords when performing administrative actions instead of
17214 @code{root}'s, similar to the behaviour used by @code{sudo}.
17217 @defvr {Scheme Variable} upower-service-type
17218 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
17219 system-wide monitor for power consumption and battery levels, with the given
17220 configuration settings.
17222 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
17223 notably used by GNOME.
17226 @deftp {Data Type} upower-configuration
17227 Data type representation the configuration for UPower.
17231 @item @code{upower} (default: @var{upower})
17232 Package to use for @code{upower}.
17234 @item @code{watts-up-pro?} (default: @code{#f})
17235 Enable the Watts Up Pro device.
17237 @item @code{poll-batteries?} (default: @code{#t})
17238 Enable polling the kernel for battery level changes.
17240 @item @code{ignore-lid?} (default: @code{#f})
17241 Ignore the lid state, this can be useful if it's incorrect on a device.
17243 @item @code{use-percentage-for-policy?} (default: @code{#f})
17244 Whether battery percentage based policy should be used. The default is to use
17245 the time left, change to @code{#t} to use the percentage.
17247 @item @code{percentage-low} (default: @code{10})
17248 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
17249 at which the battery is considered low.
17251 @item @code{percentage-critical} (default: @code{3})
17252 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
17253 at which the battery is considered critical.
17255 @item @code{percentage-action} (default: @code{2})
17256 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
17257 at which action will be taken.
17259 @item @code{time-low} (default: @code{1200})
17260 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
17261 seconds at which the battery is considered low.
17263 @item @code{time-critical} (default: @code{300})
17264 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
17265 seconds at which the battery is considered critical.
17267 @item @code{time-action} (default: @code{120})
17268 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
17269 seconds at which action will be taken.
17271 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
17272 The action taken when @code{percentage-action} or @code{time-action} is
17273 reached (depending on the configuration of @code{use-percentage-for-policy?}).
17275 Possible values are:
17285 @code{'hybrid-sleep}.
17291 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
17292 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
17293 UDisks}, a @dfn{disk management} daemon that provides user interfaces
17294 with notifications and ways to mount/unmount disks. Programs that talk
17295 to UDisks include the @command{udisksctl} command, part of UDisks, and
17296 GNOME Disks. Note that Udisks relies on the @command{mount} command, so
17297 it will only be able to use the file-system utilities installed in the
17298 system profile. For example if you want to be able to mount NTFS
17299 file-systems in read and write fashion, you'll need to have
17300 @code{ntfs-3g} installed system-wide.
17303 @deffn {Scheme Variable} colord-service-type
17304 This is the type of the service that runs @command{colord}, a system
17305 service with a D-Bus
17306 interface to manage the color profiles of input and output devices such as
17307 screens and scanners. It is notably used by the GNOME Color Manager graphical
17308 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
17309 site} for more information.
17312 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
17313 Return a configuration allowing an application to access GeoClue
17314 location data. @var{name} is the Desktop ID of the application, without
17315 the @code{.desktop} part. If @var{allowed?} is true, the application
17316 will have access to location information by default. The boolean
17317 @var{system?} value indicates whether an application is a system component
17318 or not. Finally @var{users} is a list of UIDs of all users for which
17319 this application is allowed location info access. An empty users list
17320 means that all users are allowed.
17323 @cindex scanner access
17324 @deffn {Scheme Procedure} sane-service-type
17325 This service provides access to scanners @i{via}
17326 @uref{http://www.sane-project.org, SANE} by installing the necessary udev
17330 @defvr {Scheme Variable} %standard-geoclue-applications
17331 The standard list of well-known GeoClue application configurations,
17332 granting authority to the GNOME date-and-time utility to ask for the
17333 current location in order to set the time zone, and allowing the
17334 IceCat and Epiphany web browsers to request location information.
17335 IceCat and Epiphany both query the user before allowing a web page to
17336 know the user's location.
17339 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
17340 [#:whitelist '()] @
17341 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
17342 [#:submit-data? #f]
17343 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
17344 [#:submission-nick "geoclue"] @
17345 [#:applications %standard-geoclue-applications]
17346 Return a service that runs the GeoClue location service. This service
17347 provides a D-Bus interface to allow applications to request access to a
17348 user's physical location, and optionally to add information to online
17349 location databases. See
17350 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
17351 web site} for more information.
17354 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
17355 [@w{#:auto-enable? #f}]
17356 Return a service that runs the @command{bluetoothd} daemon, which
17357 manages all the Bluetooth devices and provides a number of D-Bus
17358 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
17359 powered automatically at boot, which can be useful when using a
17360 bluetooth keyboard or mouse.
17362 Users need to be in the @code{lp} group to access the D-Bus service.
17365 @defvr {Scheme Variable} gnome-keyring-service-type
17366 This is the type of the service that adds the
17367 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
17368 value is a @code{gnome-keyring-configuration} object (see below).
17370 This service adds the @code{gnome-keyring} package to the system profile
17371 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
17372 a user's login keyring when they log in or setting its password with passwd.
17375 @deftp {Data Type} gnome-keyring-configuration
17376 Configuration record for the GNOME Keyring service.
17379 @item @code{keyring} (default: @code{gnome-keyring})
17380 The GNOME keyring package to use.
17382 @item @code{pam-services}
17383 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
17384 services to extend, where @var{service} is the name of an existing
17385 service to extend and @var{kind} is one of @code{login} or
17388 If @code{login} is given, it adds an optional
17389 @code{pam_gnome_keyring.so} to the auth block without arguments and to
17390 the session block with @code{auto_start}. If @code{passwd} is given, it
17391 adds an optional @code{pam_gnome_keyring.so} to the password block
17394 By default, this field contains ``gdm-password'' with the value @code{login}
17395 and ``passwd'' is with the value @code{passwd}.
17400 @node Sound Services
17401 @subsection Sound Services
17403 @cindex sound support
17405 @cindex PulseAudio, sound support
17407 The @code{(gnu services sound)} module provides a service to configure the
17408 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
17409 preferred ALSA output driver.
17411 @deffn {Scheme Variable} alsa-service-type
17412 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
17413 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
17414 configuration file. The value for this type is a @command{alsa-configuration}
17415 record as in this example:
17418 (service alsa-service-type)
17421 See below for details about @code{alsa-configuration}.
17424 @deftp {Data Type} alsa-configuration
17425 Data type representing the configuration for @code{alsa-service}.
17428 @item @code{alsa-plugins} (default: @var{alsa-plugins})
17429 @code{alsa-plugins} package to use.
17431 @item @code{pulseaudio?} (default: @var{#t})
17432 Whether ALSA applications should transparently be made to use the
17433 @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
17435 Using PulseAudio allows you to run several sound-producing applications
17436 at the same time and to individual control them @i{via}
17437 @command{pavucontrol}, among other things.
17439 @item @code{extra-options} (default: @var{""})
17440 String to append to the @file{/etc/asound.conf} file.
17445 Individual users who want to override the system configuration of ALSA can do
17446 it with the @file{~/.asoundrc} file:
17449 # In guix, we have to specify the absolute path for plugins.
17451 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
17454 # Routing ALSA to jack:
17455 # <http://jackaudio.org/faq/routing_alsa.html>.
17459 0 system:playback_1
17460 1 system:playback_2
17477 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
17480 @deffn {Scheme Variable} pulseaudio-service-type
17481 This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
17482 sound server. It exists to allow system overrides of the default settings
17483 via @code{pulseaudio-configuration}, see below.
17486 This service overrides per-user configuration files. If you want
17487 PulseAudio to honor configuraton files in @file{~/.config/pulse} you
17488 have to unset the environment variables @env{PULSE_CONFIG} and
17489 @env{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
17493 This service on its own does not ensure, that the @code{pulseaudio} package
17494 exists on your machine. It merely adds configuration files for it, as
17495 detailed below. In the (admittedly unlikely) case, that you find yourself
17496 without a @code{pulseaudio} package, consider enabling it through the
17497 @code{alsa-service-type} above.
17501 @deftp {Data Type} pulseaudio-configuration
17502 Data type representing the configuration for @code{pulseaudio-service}.
17505 @item @var{client-conf} (default: @code{'()})
17506 List of settings to set in @file{client.conf}.
17507 Accepts a list of strings or a symbol-value pairs. A string will be
17508 inserted as-is with a newline added. A pair will be formatted as
17509 ``key = value'', again with a newline added.
17511 @item @var{daemon-conf} (default: @code{'((flat-volumes . no))})
17512 List of settings to set in @file{daemon.conf}, formatted just like
17515 @item @var{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
17516 Script file to use as as @file{default.pa}.
17518 @item @var{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
17519 Script file to use as as @file{system.pa}.
17523 @deffn {Scheme Variable} ladspa-service-type
17524 This service sets the @var{LADSPA_PATH} variable, so that programs, which
17525 respect it, e.g. PulseAudio, can load LADSPA plugins.
17527 The following example will setup the service to enable modules from the
17528 @code{swh-plugins} package:
17531 (service ladspa-service-type
17532 (ladspa-configuration (plugins (list swh-plugins))))
17535 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
17540 @node Database Services
17541 @subsection Database Services
17545 The @code{(gnu services databases)} module provides the following services.
17547 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
17548 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
17549 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
17550 Return a service that runs @var{postgresql}, the PostgreSQL database
17553 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
17554 creates a database cluster with @var{locale} as the default
17555 locale, stored in @var{data-directory}. It then listens on @var{port}.
17557 If the services fails to start, it may be due to an incompatible
17558 cluster already present in @var{data-directory}. Adjust it (or, if you
17559 don't need the cluster anymore, delete @var{data-directory}), then
17560 restart the service.
17562 Peer authentication is used by default and the @code{postgres} user
17563 account has no shell, which prevents the direct execution of @code{psql}
17564 commands as this user. To use @code{psql}, you can temporarily log in
17565 as @code{postgres} using a shell, create a PostgreSQL superuser with the
17566 same name as one of the system users and then create the associated
17570 sudo -u postgres -s /bin/sh
17571 createuser --interactive
17572 createdb $MY_USER_LOGIN # Replace appropriately.
17575 @cindex postgresql extension-packages
17576 Additional extensions are loaded from packages listed in
17577 @var{extension-packages}. Extensions are available at runtime. For instance,
17578 to create a geographic database using the @code{postgis} extension, a user can
17579 configure the postgresql-service as in this example:
17583 (use-package-modules databases geo)
17587 ;; postgresql is required to run `psql' but postgis is not required for
17588 ;; proper operation.
17589 (packages (cons* postgresql %base-packages))
17592 (postgresql-service #:extension-packages (list postgis))
17596 Then the extension becomes visible and you can initialise an empty geographic
17597 database in this way:
17601 > create database postgistest;
17602 > \connect postgistest;
17603 > create extension postgis;
17604 > create extension postgis_topology;
17607 There is no need to add this field for contrib extensions such as hstore or
17608 dblink as they are already loadable by postgresql. This field is only
17609 required to add extensions provided by other packages.
17612 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
17613 Return a service that runs @command{mysqld}, the MySQL or MariaDB
17616 The optional @var{config} argument specifies the configuration for
17617 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
17620 @deftp {Data Type} mysql-configuration
17621 Data type representing the configuration of @var{mysql-service}.
17624 @item @code{mysql} (default: @var{mariadb})
17625 Package object of the MySQL database server, can be either @var{mariadb}
17628 For MySQL, a temporary root password will be displayed at activation time.
17629 For MariaDB, the root password is empty.
17631 @item @code{port} (default: @code{3306})
17632 TCP port on which the database server listens for incoming connections.
17636 @defvr {Scheme Variable} memcached-service-type
17637 This is the service type for the @uref{https://memcached.org/,
17638 Memcached} service, which provides a distributed in memory cache. The
17639 value for the service type is a @code{memcached-configuration} object.
17643 (service memcached-service-type)
17646 @deftp {Data Type} memcached-configuration
17647 Data type representing the configuration of memcached.
17650 @item @code{memcached} (default: @code{memcached})
17651 The Memcached package to use.
17653 @item @code{interfaces} (default: @code{'("0.0.0.0")})
17654 Network interfaces on which to listen.
17656 @item @code{tcp-port} (default: @code{11211})
17657 Port on which to accept connections on,
17659 @item @code{udp-port} (default: @code{11211})
17660 Port on which to accept UDP connections on, a value of 0 will disable
17661 listening on a UDP socket.
17663 @item @code{additional-options} (default: @code{'()})
17664 Additional command line options to pass to @code{memcached}.
17668 @defvr {Scheme Variable} mongodb-service-type
17669 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
17670 The value for the service type is a @code{mongodb-configuration} object.
17674 (service mongodb-service-type)
17677 @deftp {Data Type} mongodb-configuration
17678 Data type representing the configuration of mongodb.
17681 @item @code{mongodb} (default: @code{mongodb})
17682 The MongoDB package to use.
17684 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
17685 The configuration file for MongoDB.
17687 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
17688 This value is used to create the directory, so that it exists and is
17689 owned by the mongodb user. It should match the data-directory which
17690 MongoDB is configured to use through the configuration file.
17694 @defvr {Scheme Variable} redis-service-type
17695 This is the service type for the @uref{https://redis.io/, Redis}
17696 key/value store, whose value is a @code{redis-configuration} object.
17699 @deftp {Data Type} redis-configuration
17700 Data type representing the configuration of redis.
17703 @item @code{redis} (default: @code{redis})
17704 The Redis package to use.
17706 @item @code{bind} (default: @code{"127.0.0.1"})
17707 Network interface on which to listen.
17709 @item @code{port} (default: @code{6379})
17710 Port on which to accept connections on, a value of 0 will disable
17711 listening on a TCP socket.
17713 @item @code{working-directory} (default: @code{"/var/lib/redis"})
17714 Directory in which to store the database and related files.
17718 @node Mail Services
17719 @subsection Mail Services
17723 The @code{(gnu services mail)} module provides Guix service definitions
17724 for email services: IMAP, POP3, and LMTP servers, as well as mail
17725 transport agents (MTAs). Lots of acronyms! These services are detailed
17726 in the subsections below.
17728 @subsubheading Dovecot Service
17730 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
17731 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
17734 By default, Dovecot does not need much configuration; the default
17735 configuration object created by @code{(dovecot-configuration)} will
17736 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
17737 certificate will be generated for TLS-protected connections, though
17738 Dovecot will also listen on cleartext ports by default. There are a
17739 number of options, though, which mail administrators might need to change,
17740 and as is the case with other services, Guix allows the system
17741 administrator to specify these parameters via a uniform Scheme interface.
17743 For example, to specify that mail is located at @code{maildir~/.mail},
17744 one would instantiate the Dovecot service like this:
17747 (dovecot-service #:config
17748 (dovecot-configuration
17749 (mail-location "maildir:~/.mail")))
17752 The available configuration parameters follow. Each parameter
17753 definition is preceded by its type; for example, @samp{string-list foo}
17754 indicates that the @code{foo} parameter should be specified as a list of
17755 strings. There is also a way to specify the configuration as a string,
17756 if you have an old @code{dovecot.conf} file that you want to port over
17757 from some other system; see the end for more details.
17759 @c The following documentation was initially generated by
17760 @c (generate-documentation) in (gnu services mail). Manually maintained
17761 @c documentation is better, so we shouldn't hesitate to edit below as
17762 @c needed. However if the change you want to make to this documentation
17763 @c can be done in an automated way, it's probably easier to change
17764 @c (generate-documentation) than to make it below and have to deal with
17765 @c the churn as dovecot updates.
17767 Available @code{dovecot-configuration} fields are:
17769 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
17770 The dovecot package.
17773 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
17774 A list of IPs or hosts where to listen for connections. @samp{*}
17775 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
17776 interfaces. If you want to specify non-default ports or anything more
17777 complex, customize the address and port fields of the
17778 @samp{inet-listener} of the specific services you are interested in.
17781 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
17782 List of protocols we want to serve. Available protocols include
17783 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
17785 Available @code{protocol-configuration} fields are:
17787 @deftypevr {@code{protocol-configuration} parameter} string name
17788 The name of the protocol.
17791 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
17792 UNIX socket path to the master authentication server to find users.
17793 This is used by imap (for shared users) and lda.
17794 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
17797 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
17798 Space separated list of plugins to load.
17801 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
17802 Maximum number of IMAP connections allowed for a user from each IP
17803 address. NOTE: The username is compared case-sensitively.
17804 Defaults to @samp{10}.
17809 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
17810 List of services to enable. Available services include @samp{imap},
17811 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
17814 Available @code{service-configuration} fields are:
17816 @deftypevr {@code{service-configuration} parameter} string kind
17817 The service kind. Valid values include @code{director},
17818 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
17819 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
17820 @code{tcpwrap}, @code{quota-warning}, or anything else.
17823 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
17824 Listeners for the service. A listener is either a
17825 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
17826 an @code{inet-listener-configuration}.
17827 Defaults to @samp{()}.
17829 Available @code{unix-listener-configuration} fields are:
17831 @deftypevr {@code{unix-listener-configuration} parameter} string path
17832 Path to the file, relative to @code{base-dir} field. This is also used as
17836 @deftypevr {@code{unix-listener-configuration} parameter} string mode
17837 The access mode for the socket.
17838 Defaults to @samp{"0600"}.
17841 @deftypevr {@code{unix-listener-configuration} parameter} string user
17842 The user to own the socket.
17843 Defaults to @samp{""}.
17846 @deftypevr {@code{unix-listener-configuration} parameter} string group
17847 The group to own the socket.
17848 Defaults to @samp{""}.
17852 Available @code{fifo-listener-configuration} fields are:
17854 @deftypevr {@code{fifo-listener-configuration} parameter} string path
17855 Path to the file, relative to @code{base-dir} field. This is also used as
17859 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
17860 The access mode for the socket.
17861 Defaults to @samp{"0600"}.
17864 @deftypevr {@code{fifo-listener-configuration} parameter} string user
17865 The user to own the socket.
17866 Defaults to @samp{""}.
17869 @deftypevr {@code{fifo-listener-configuration} parameter} string group
17870 The group to own the socket.
17871 Defaults to @samp{""}.
17875 Available @code{inet-listener-configuration} fields are:
17877 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
17878 The protocol to listen for.
17881 @deftypevr {@code{inet-listener-configuration} parameter} string address
17882 The address on which to listen, or empty for all addresses.
17883 Defaults to @samp{""}.
17886 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
17887 The port on which to listen.
17890 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
17891 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
17893 Defaults to @samp{#t}.
17898 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
17899 Maximum number of simultaneous client connections per process. Once
17900 this number of connections is received, the next incoming connection
17901 will prompt Dovecot to spawn another process. If set to 0,
17902 @code{default-client-limit} is used instead.
17904 Defaults to @samp{0}.
17908 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
17909 Number of connections to handle before starting a new process.
17910 Typically the only useful values are 0 (unlimited) or 1. 1 is more
17911 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
17912 Defaults to @samp{1}.
17916 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
17917 Maximum number of processes that can exist for this service. If set to
17918 0, @code{default-process-limit} is used instead.
17920 Defaults to @samp{0}.
17924 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
17925 Number of processes to always keep waiting for more connections.
17926 Defaults to @samp{0}.
17929 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
17930 If you set @samp{service-count 0}, you probably need to grow
17932 Defaults to @samp{256000000}.
17937 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
17938 Dict configuration, as created by the @code{dict-configuration}
17941 Available @code{dict-configuration} fields are:
17943 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
17944 A list of key-value pairs that this dict should hold.
17945 Defaults to @samp{()}.
17950 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
17951 A list of passdb configurations, each one created by the
17952 @code{passdb-configuration} constructor.
17954 Available @code{passdb-configuration} fields are:
17956 @deftypevr {@code{passdb-configuration} parameter} string driver
17957 The driver that the passdb should use. Valid values include
17958 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
17960 Defaults to @samp{"pam"}.
17963 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
17964 Space separated list of arguments to the passdb driver.
17965 Defaults to @samp{""}.
17970 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
17971 List of userdb configurations, each one created by the
17972 @code{userdb-configuration} constructor.
17974 Available @code{userdb-configuration} fields are:
17976 @deftypevr {@code{userdb-configuration} parameter} string driver
17977 The driver that the userdb should use. Valid values include
17978 @samp{passwd} and @samp{static}.
17979 Defaults to @samp{"passwd"}.
17982 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
17983 Space separated list of arguments to the userdb driver.
17984 Defaults to @samp{""}.
17987 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
17988 Override fields from passwd.
17989 Defaults to @samp{()}.
17994 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
17995 Plug-in configuration, created by the @code{plugin-configuration}
17999 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
18000 List of namespaces. Each item in the list is created by the
18001 @code{namespace-configuration} constructor.
18003 Available @code{namespace-configuration} fields are:
18005 @deftypevr {@code{namespace-configuration} parameter} string name
18006 Name for this namespace.
18009 @deftypevr {@code{namespace-configuration} parameter} string type
18010 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
18011 Defaults to @samp{"private"}.
18014 @deftypevr {@code{namespace-configuration} parameter} string separator
18015 Hierarchy separator to use. You should use the same separator for
18016 all namespaces or some clients get confused. @samp{/} is usually a good
18017 one. The default however depends on the underlying mail storage
18019 Defaults to @samp{""}.
18022 @deftypevr {@code{namespace-configuration} parameter} string prefix
18023 Prefix required to access this namespace. This needs to be
18024 different for all namespaces. For example @samp{Public/}.
18025 Defaults to @samp{""}.
18028 @deftypevr {@code{namespace-configuration} parameter} string location
18029 Physical location of the mailbox. This is in the same format as
18030 mail_location, which is also the default for it.
18031 Defaults to @samp{""}.
18034 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
18035 There can be only one INBOX, and this setting defines which
18037 Defaults to @samp{#f}.
18040 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
18041 If namespace is hidden, it's not advertised to clients via NAMESPACE
18042 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
18043 useful when converting from another server with different namespaces
18044 which you want to deprecate but still keep working. For example you can
18045 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
18047 Defaults to @samp{#f}.
18050 @deftypevr {@code{namespace-configuration} parameter} boolean list?
18051 Show the mailboxes under this namespace with the LIST command. This
18052 makes the namespace visible for clients that do not support the NAMESPACE
18053 extension. The special @code{children} value lists child mailboxes, but
18054 hides the namespace prefix.
18055 Defaults to @samp{#t}.
18058 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
18059 Namespace handles its own subscriptions. If set to @code{#f}, the
18060 parent namespace handles them. The empty prefix should always have this
18062 Defaults to @samp{#t}.
18065 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
18066 List of predefined mailboxes in this namespace.
18067 Defaults to @samp{()}.
18069 Available @code{mailbox-configuration} fields are:
18071 @deftypevr {@code{mailbox-configuration} parameter} string name
18072 Name for this mailbox.
18075 @deftypevr {@code{mailbox-configuration} parameter} string auto
18076 @samp{create} will automatically create this mailbox.
18077 @samp{subscribe} will both create and subscribe to the mailbox.
18078 Defaults to @samp{"no"}.
18081 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
18082 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
18083 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
18084 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
18085 Defaults to @samp{()}.
18092 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
18093 Base directory where to store runtime data.
18094 Defaults to @samp{"/var/run/dovecot/"}.
18097 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
18098 Greeting message for clients.
18099 Defaults to @samp{"Dovecot ready."}.
18102 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
18103 List of trusted network ranges. Connections from these IPs are
18104 allowed to override their IP addresses and ports (for logging and for
18105 authentication checks). @samp{disable-plaintext-auth} is also ignored
18106 for these networks. Typically you would specify your IMAP proxy servers
18108 Defaults to @samp{()}.
18111 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
18112 List of login access check sockets (e.g.@: tcpwrap).
18113 Defaults to @samp{()}.
18116 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
18117 Show more verbose process titles (in ps). Currently shows user name
18118 and IP address. Useful for seeing who is actually using the IMAP
18119 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
18121 Defaults to @samp{#f}.
18124 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
18125 Should all processes be killed when Dovecot master process shuts down.
18126 Setting this to @code{#f} means that Dovecot can be upgraded without
18127 forcing existing client connections to close (although that could also
18128 be a problem if the upgrade is e.g.@: due to a security fix).
18129 Defaults to @samp{#t}.
18132 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
18133 If non-zero, run mail commands via this many connections to doveadm
18134 server, instead of running them directly in the same process.
18135 Defaults to @samp{0}.
18138 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
18139 UNIX socket or host:port used for connecting to doveadm server.
18140 Defaults to @samp{"doveadm-server"}.
18143 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
18144 List of environment variables that are preserved on Dovecot startup
18145 and passed down to all of its child processes. You can also give
18146 key=value pairs to always set specific settings.
18149 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
18150 Disable LOGIN command and all other plaintext authentications unless
18151 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
18152 matches the local IP (i.e.@: you're connecting from the same computer),
18153 the connection is considered secure and plaintext authentication is
18154 allowed. See also ssl=required setting.
18155 Defaults to @samp{#t}.
18158 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
18159 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
18160 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
18161 for caching to be used.
18162 Defaults to @samp{0}.
18165 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
18166 Time to live for cached data. After TTL expires the cached record
18167 is no longer used, *except* if the main database lookup returns internal
18168 failure. We also try to handle password changes automatically: If
18169 user's previous authentication was successful, but this one wasn't, the
18170 cache isn't used. For now this works only with plaintext
18172 Defaults to @samp{"1 hour"}.
18175 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
18176 TTL for negative hits (user not found, password mismatch).
18177 0 disables caching them completely.
18178 Defaults to @samp{"1 hour"}.
18181 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
18182 List of realms for SASL authentication mechanisms that need them.
18183 You can leave it empty if you don't want to support multiple realms.
18184 Many clients simply use the first one listed here, so keep the default
18186 Defaults to @samp{()}.
18189 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
18190 Default realm/domain to use if none was specified. This is used for
18191 both SASL realms and appending @@domain to username in plaintext
18193 Defaults to @samp{""}.
18196 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
18197 List of allowed characters in username. If the user-given username
18198 contains a character not listed in here, the login automatically fails.
18199 This is just an extra check to make sure user can't exploit any
18200 potential quote escaping vulnerabilities with SQL/LDAP databases. If
18201 you want to allow all characters, set this value to empty.
18202 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
18205 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
18206 Username character translations before it's looked up from
18207 databases. The value contains series of from -> to characters. For
18208 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
18209 translated to @samp{@@}.
18210 Defaults to @samp{""}.
18213 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
18214 Username formatting before it's looked up from databases. You can
18215 use the standard variables here, e.g.@: %Lu would lowercase the username,
18216 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
18217 change the @samp{@@} into @samp{-AT-}. This translation is done after
18218 @samp{auth-username-translation} changes.
18219 Defaults to @samp{"%Lu"}.
18222 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
18223 If you want to allow master users to log in by specifying the master
18224 username within the normal username string (i.e.@: not using SASL
18225 mechanism's support for it), you can specify the separator character
18226 here. The format is then <username><separator><master username>.
18227 UW-IMAP uses @samp{*} as the separator, so that could be a good
18229 Defaults to @samp{""}.
18232 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
18233 Username to use for users logging in with ANONYMOUS SASL
18235 Defaults to @samp{"anonymous"}.
18238 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
18239 Maximum number of dovecot-auth worker processes. They're used to
18240 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
18241 They're automatically created and destroyed as needed.
18242 Defaults to @samp{30}.
18245 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
18246 Host name to use in GSSAPI principal names. The default is to use
18247 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
18248 allow all keytab entries.
18249 Defaults to @samp{""}.
18252 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
18253 Kerberos keytab to use for the GSSAPI mechanism. Will use the
18254 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
18255 need to change the auth service to run as root to be able to read this
18257 Defaults to @samp{""}.
18260 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
18261 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
18262 and @samp{ntlm-auth} helper.
18263 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
18264 Defaults to @samp{#f}.
18267 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
18268 Path for Samba's @samp{ntlm-auth} helper binary.
18269 Defaults to @samp{"/usr/bin/ntlm_auth"}.
18272 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
18273 Time to delay before replying to failed authentications.
18274 Defaults to @samp{"2 secs"}.
18277 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
18278 Require a valid SSL client certificate or the authentication
18280 Defaults to @samp{#f}.
18283 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
18284 Take the username from client's SSL certificate, using
18285 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
18287 Defaults to @samp{#f}.
18290 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
18291 List of wanted authentication mechanisms. Supported mechanisms are:
18292 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
18293 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
18294 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
18295 @samp{disable-plaintext-auth} setting.
18298 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
18299 List of IPs or hostnames to all director servers, including ourself.
18300 Ports can be specified as ip:port. The default port is the same as what
18301 director service's @samp{inet-listener} is using.
18302 Defaults to @samp{()}.
18305 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
18306 List of IPs or hostnames to all backend mail servers. Ranges are
18307 allowed too, like 10.0.0.10-10.0.0.30.
18308 Defaults to @samp{()}.
18311 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
18312 How long to redirect users to a specific server after it no longer
18313 has any connections.
18314 Defaults to @samp{"15 min"}.
18317 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
18318 How the username is translated before being hashed. Useful values
18319 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
18320 are shared within domain.
18321 Defaults to @samp{"%Lu"}.
18324 @deftypevr {@code{dovecot-configuration} parameter} string log-path
18325 Log file to use for error messages. @samp{syslog} logs to syslog,
18326 @samp{/dev/stderr} logs to stderr.
18327 Defaults to @samp{"syslog"}.
18330 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
18331 Log file to use for informational messages. Defaults to
18333 Defaults to @samp{""}.
18336 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
18337 Log file to use for debug messages. Defaults to
18338 @samp{info-log-path}.
18339 Defaults to @samp{""}.
18342 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
18343 Syslog facility to use if you're logging to syslog. Usually if you
18344 don't want to use @samp{mail}, you'll use local0..local7. Also other
18345 standard facilities are supported.
18346 Defaults to @samp{"mail"}.
18349 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
18350 Log unsuccessful authentication attempts and the reasons why they
18352 Defaults to @samp{#f}.
18355 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
18356 In case of password mismatches, log the attempted password. Valid
18357 values are no, plain and sha1. sha1 can be useful for detecting brute
18358 force password attempts vs. user simply trying the same password over
18359 and over again. You can also truncate the value to n chars by appending
18360 ":n" (e.g.@: sha1:6).
18361 Defaults to @samp{"no"}.
18364 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
18365 Even more verbose logging for debugging purposes. Shows for example
18367 Defaults to @samp{#f}.
18370 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
18371 In case of password mismatches, log the passwords and used scheme so
18372 the problem can be debugged. Enabling this also enables
18374 Defaults to @samp{#f}.
18377 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
18378 Enable mail process debugging. This can help you figure out why
18379 Dovecot isn't finding your mails.
18380 Defaults to @samp{#f}.
18383 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
18384 Show protocol level SSL errors.
18385 Defaults to @samp{#f}.
18388 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
18389 Prefix for each line written to log file. % codes are in
18390 strftime(3) format.
18391 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
18394 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
18395 List of elements we want to log. The elements which have a
18396 non-empty variable value are joined together to form a comma-separated
18400 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
18401 Login log format. %s contains @samp{login-log-format-elements}
18402 string, %$ contains the data we want to log.
18403 Defaults to @samp{"%$: %s"}.
18406 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
18407 Log prefix for mail processes. See doc/wiki/Variables.txt for list
18408 of possible variables you can use.
18409 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
18412 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
18413 Format to use for logging mail deliveries. You can use variables:
18416 Delivery status message (e.g.@: @samp{saved to INBOX})
18428 Defaults to @samp{"msgid=%m: %$"}.
18431 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
18432 Location for users' mailboxes. The default is empty, which means
18433 that Dovecot tries to find the mailboxes automatically. This won't work
18434 if the user doesn't yet have any mail, so you should explicitly tell
18435 Dovecot the full location.
18437 If you're using mbox, giving a path to the INBOX
18438 file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
18439 where the other mailboxes are kept. This is called the @emph{root mail
18440 directory}, and it must be the first path given in the
18441 @samp{mail-location} setting.
18443 There are a few special variables you can use, e.g.:
18449 user part in user@@domain, same as %u if there's no domain
18451 domain part in user@@domain, empty if there's no domain
18456 See doc/wiki/Variables.txt for full list. Some examples:
18458 @item maildir:~/Maildir
18459 @item mbox:~/mail:INBOX=/var/mail/%u
18460 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
18462 Defaults to @samp{""}.
18465 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
18466 System user and group used to access mails. If you use multiple,
18467 userdb can override these by returning uid or gid fields. You can use
18468 either numbers or names. <doc/wiki/UserIds.txt>.
18469 Defaults to @samp{""}.
18472 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
18474 Defaults to @samp{""}.
18477 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
18478 Group to enable temporarily for privileged operations. Currently
18479 this is used only with INBOX when either its initial creation or
18480 dotlocking fails. Typically this is set to @samp{"mail"} to give access to
18482 Defaults to @samp{""}.
18485 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
18486 Grant access to these supplementary groups for mail processes.
18487 Typically these are used to set up access to shared mailboxes. Note
18488 that it may be dangerous to set these if users can create symlinks
18489 (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
18490 could allow a user to delete others' mailboxes, or @code{ln -s
18491 /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
18495 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
18496 Allow full file system access to clients. There's no access checks
18497 other than what the operating system does for the active UID/GID. It
18498 works with both maildir and mboxes, allowing you to prefix mailboxes
18499 names with e.g.@: @file{/path/} or @file{~user/}.
18500 Defaults to @samp{#f}.
18503 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
18504 Don't use @code{mmap()} at all. This is required if you store indexes to
18505 shared file systems (NFS or clustered file system).
18506 Defaults to @samp{#f}.
18509 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
18510 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
18511 supports @samp{O_EXCL} since version 3, so this should be safe to use
18512 nowadays by default.
18513 Defaults to @samp{#t}.
18516 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
18517 When to use fsync() or fdatasync() calls:
18520 Whenever necessary to avoid losing important data
18522 Useful with e.g.@: NFS when @code{write()}s are delayed
18524 Never use it (best performance, but crashes can lose data).
18526 Defaults to @samp{"optimized"}.
18529 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
18530 Mail storage exists in NFS. Set this to yes to make Dovecot flush
18531 NFS caches whenever needed. If you're using only a single mail server
18533 Defaults to @samp{#f}.
18536 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
18537 Mail index files also exist in NFS. Setting this to yes requires
18538 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
18539 Defaults to @samp{#f}.
18542 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
18543 Locking method for index files. Alternatives are fcntl, flock and
18544 dotlock. Dotlocking uses some tricks which may create more disk I/O
18545 than other locking methods. NFS users: flock doesn't work, remember to
18546 change @samp{mmap-disable}.
18547 Defaults to @samp{"fcntl"}.
18550 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
18551 Directory in which LDA/LMTP temporarily stores incoming mails >128
18553 Defaults to @samp{"/tmp"}.
18556 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
18557 Valid UID range for users. This is mostly to make sure that users can't
18558 log in as daemons or other system users. Note that denying root logins is
18559 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
18561 Defaults to @samp{500}.
18564 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
18566 Defaults to @samp{0}.
18569 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
18570 Valid GID range for users. Users having non-valid GID as primary group ID
18571 aren't allowed to log in. If user belongs to supplementary groups with
18572 non-valid GIDs, those groups are not set.
18573 Defaults to @samp{1}.
18576 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
18578 Defaults to @samp{0}.
18581 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
18582 Maximum allowed length for mail keyword name. It's only forced when
18583 trying to create new keywords.
18584 Defaults to @samp{50}.
18587 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
18588 List of directories under which chrooting is allowed for mail
18589 processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
18590 too). This setting doesn't affect @samp{login-chroot}
18591 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
18592 @samp{/./} in home dirs are ignored. WARNING: Never add directories here
18593 which local users can modify, that may lead to root exploit. Usually
18594 this should be done only if you don't allow shell access for users.
18595 <doc/wiki/Chrooting.txt>.
18596 Defaults to @samp{()}.
18599 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
18600 Default chroot directory for mail processes. This can be overridden
18601 for specific users in user database by giving @samp{/./} in user's home
18602 directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
18603 there is no real need to do chrooting, Dovecot doesn't allow users to
18604 access files outside their mail directory anyway. If your home
18605 directories are prefixed with the chroot directory, append @samp{/.} to
18606 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
18607 Defaults to @samp{""}.
18610 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
18611 UNIX socket path to master authentication server to find users.
18612 This is used by imap (for shared users) and lda.
18613 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
18616 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
18617 Directory where to look up mail plugins.
18618 Defaults to @samp{"/usr/lib/dovecot"}.
18621 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
18622 List of plugins to load for all services. Plugins specific to IMAP,
18623 LDA, etc.@: are added to this list in their own .conf files.
18624 Defaults to @samp{()}.
18627 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
18628 The minimum number of mails in a mailbox before updates are done to
18629 cache file. This allows optimizing Dovecot's behavior to do less disk
18630 writes at the cost of more disk reads.
18631 Defaults to @samp{0}.
18634 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
18635 When IDLE command is running, mailbox is checked once in a while to
18636 see if there are any new mails or other changes. This setting defines
18637 the minimum time to wait between those checks. Dovecot can also use
18638 dnotify, inotify and kqueue to find out immediately when changes
18640 Defaults to @samp{"30 secs"}.
18643 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
18644 Save mails with CR+LF instead of plain LF. This makes sending those
18645 mails take less CPU, especially with sendfile() syscall with Linux and
18646 FreeBSD. But it also creates a bit more disk I/O which may just make it
18647 slower. Also note that if other software reads the mboxes/maildirs,
18648 they may handle the extra CRs wrong and cause problems.
18649 Defaults to @samp{#f}.
18652 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
18653 By default LIST command returns all entries in maildir beginning
18654 with a dot. Enabling this option makes Dovecot return only entries
18655 which are directories. This is done by stat()ing each entry, so it
18656 causes more disk I/O.
18657 (For systems setting struct @samp{dirent->d_type} this check is free
18658 and it's done always regardless of this setting).
18659 Defaults to @samp{#f}.
18662 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
18663 When copying a message, do it with hard links whenever possible.
18664 This makes the performance much better, and it's unlikely to have any
18666 Defaults to @samp{#t}.
18669 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
18670 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
18671 directory only when its mtime changes unexpectedly or when we can't find
18672 the mail otherwise.
18673 Defaults to @samp{#f}.
18676 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
18677 Which locking methods to use for locking mbox. There are four
18682 Create <mailbox>.lock file. This is the oldest and most NFS-safe
18683 solution. If you want to use /var/mail/ like directory, the users will
18684 need write access to that directory.
18686 Same as dotlock, but if it fails because of permissions or because there
18687 isn't enough disk space, just skip it.
18689 Use this if possible. Works with NFS too if lockd is used.
18691 May not exist in all systems. Doesn't work with NFS.
18693 May not exist in all systems. Doesn't work with NFS.
18696 You can use multiple locking methods; if you do the order they're declared
18697 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
18698 locking methods as well. Some operating systems don't allow using some of
18699 them simultaneously.
18702 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
18706 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
18707 Maximum time to wait for lock (all of them) before aborting.
18708 Defaults to @samp{"5 mins"}.
18711 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
18712 If dotlock exists but the mailbox isn't modified in any way,
18713 override the lock file after this much time.
18714 Defaults to @samp{"2 mins"}.
18717 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
18718 When mbox changes unexpectedly we have to fully read it to find out
18719 what changed. If the mbox is large this can take a long time. Since
18720 the change is usually just a newly appended mail, it'd be faster to
18721 simply read the new mails. If this setting is enabled, Dovecot does
18722 this but still safely fallbacks to re-reading the whole mbox file
18723 whenever something in mbox isn't how it's expected to be. The only real
18724 downside to this setting is that if some other MUA changes message
18725 flags, Dovecot doesn't notice it immediately. Note that a full sync is
18726 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
18727 Defaults to @samp{#t}.
18730 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
18731 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
18732 EXAMINE, EXPUNGE or CHECK commands. If this is set,
18733 @samp{mbox-dirty-syncs} is ignored.
18734 Defaults to @samp{#f}.
18737 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
18738 Delay writing mbox headers until doing a full write sync (EXPUNGE
18739 and CHECK commands and when closing the mailbox). This is especially
18740 useful for POP3 where clients often delete all mails. The downside is
18741 that our changes aren't immediately visible to other MUAs.
18742 Defaults to @samp{#t}.
18745 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
18746 If mbox size is smaller than this (e.g.@: 100k), don't write index
18747 files. If an index file already exists it's still read, just not
18749 Defaults to @samp{0}.
18752 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
18753 Maximum dbox file size until it's rotated.
18754 Defaults to @samp{10000000}.
18757 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
18758 Maximum dbox file age until it's rotated. Typically in days. Day
18759 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
18761 Defaults to @samp{"1d"}.
18764 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
18765 When creating new mdbox files, immediately preallocate their size to
18766 @samp{mdbox-rotate-size}. This setting currently works only in Linux
18767 with some file systems (ext4, xfs).
18768 Defaults to @samp{#f}.
18771 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
18772 sdbox and mdbox support saving mail attachments to external files,
18773 which also allows single instance storage for them. Other backends
18774 don't support this for now.
18776 WARNING: This feature hasn't been tested much yet. Use at your own risk.
18778 Directory root where to store mail attachments. Disabled, if empty.
18779 Defaults to @samp{""}.
18782 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
18783 Attachments smaller than this aren't saved externally. It's also
18784 possible to write a plugin to disable saving specific attachments
18786 Defaults to @samp{128000}.
18789 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
18790 File system backend to use for saving attachments:
18793 No SiS done by Dovecot (but this might help FS's own deduplication)
18795 SiS with immediate byte-by-byte comparison during saving
18796 @item sis-queue posix
18797 SiS with delayed comparison and deduplication.
18799 Defaults to @samp{"sis posix"}.
18802 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
18803 Hash format to use in attachment filenames. You can add any text and
18804 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
18805 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
18806 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
18807 Defaults to @samp{"%@{sha1@}"}.
18810 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
18812 Defaults to @samp{100}.
18815 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
18817 Defaults to @samp{1000}.
18820 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
18821 Default VSZ (virtual memory size) limit for service processes.
18822 This is mainly intended to catch and kill processes that leak memory
18823 before they eat up everything.
18824 Defaults to @samp{256000000}.
18827 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
18828 Login user is internally used by login processes. This is the most
18829 untrusted user in Dovecot system. It shouldn't have access to anything
18831 Defaults to @samp{"dovenull"}.
18834 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
18835 Internal user is used by unprivileged processes. It should be
18836 separate from login user, so that login processes can't disturb other
18838 Defaults to @samp{"dovecot"}.
18841 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
18842 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
18843 Defaults to @samp{"required"}.
18846 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
18847 PEM encoded X.509 SSL/TLS certificate (public key).
18848 Defaults to @samp{"</etc/dovecot/default.pem"}.
18851 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
18852 PEM encoded SSL/TLS private key. The key is opened before
18853 dropping root privileges, so keep the key file unreadable by anyone but
18855 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
18858 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
18859 If key file is password protected, give the password here.
18860 Alternatively give it when starting dovecot with -p parameter. Since
18861 this file is often world-readable, you may want to place this setting
18862 instead to a different.
18863 Defaults to @samp{""}.
18866 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
18867 PEM encoded trusted certificate authority. Set this only if you
18868 intend to use @samp{ssl-verify-client-cert? #t}. The file should
18869 contain the CA certificate(s) followed by the matching
18870 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
18871 Defaults to @samp{""}.
18874 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
18875 Require that CRL check succeeds for client certificates.
18876 Defaults to @samp{#t}.
18879 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
18880 Request client to send a certificate. If you also want to require
18881 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
18882 Defaults to @samp{#f}.
18885 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
18886 Which field from certificate to use for username. commonName and
18887 x500UniqueIdentifier are the usual choices. You'll also need to set
18888 @samp{auth-ssl-username-from-cert? #t}.
18889 Defaults to @samp{"commonName"}.
18892 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
18893 Minimum SSL protocol version to accept.
18894 Defaults to @samp{"TLSv1"}.
18897 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
18898 SSL ciphers to use.
18899 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
18902 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
18903 SSL crypto device to use, for valid values run "openssl engine".
18904 Defaults to @samp{""}.
18907 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
18908 Address to use when sending rejection mails.
18909 %d expands to recipient domain.
18910 Defaults to @samp{"postmaster@@%d"}.
18913 @deftypevr {@code{dovecot-configuration} parameter} string hostname
18914 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
18915 and in LMTP replies. Default is the system's real hostname@@domain.
18916 Defaults to @samp{""}.
18919 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
18920 If user is over quota, return with temporary failure instead of
18922 Defaults to @samp{#f}.
18925 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
18926 Binary to use for sending mails.
18927 Defaults to @samp{"/usr/sbin/sendmail"}.
18930 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
18931 If non-empty, send mails via this SMTP host[:port] instead of
18933 Defaults to @samp{""}.
18936 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
18937 Subject: header to use for rejection mails. You can use the same
18938 variables as for @samp{rejection-reason} below.
18939 Defaults to @samp{"Rejected: %s"}.
18942 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
18943 Human readable error message for rejection mails. You can use
18956 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
18959 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
18960 Delimiter character between local-part and detail in email
18962 Defaults to @samp{"+"}.
18965 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
18966 Header where the original recipient address (SMTP's RCPT TO:
18967 address) is taken from if not available elsewhere. With dovecot-lda -a
18968 parameter overrides this. A commonly used header for this is
18970 Defaults to @samp{""}.
18973 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
18974 Should saving a mail to a nonexistent mailbox automatically create
18976 Defaults to @samp{#f}.
18979 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
18980 Should automatically created mailboxes be also automatically
18982 Defaults to @samp{#f}.
18985 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
18986 Maximum IMAP command line length. Some clients generate very long
18987 command lines with huge mailboxes, so you may need to raise this if you
18988 get "Too long argument" or "IMAP command line too large" errors
18990 Defaults to @samp{64000}.
18993 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
18994 IMAP logout format string:
18997 total number of bytes read from client
18999 total number of bytes sent to client.
19001 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
19002 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@}"}.
19005 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
19006 Override the IMAP CAPABILITY response. If the value begins with '+',
19007 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
19008 Defaults to @samp{""}.
19011 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
19012 How long to wait between "OK Still here" notifications when client
19014 Defaults to @samp{"2 mins"}.
19017 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
19018 ID field names and values to send to clients. Using * as the value
19019 makes Dovecot use the default value. The following fields have default
19020 values currently: name, version, os, os-version, support-url,
19022 Defaults to @samp{""}.
19025 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
19026 ID fields sent by client to log. * means everything.
19027 Defaults to @samp{""}.
19030 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
19031 Workarounds for various client bugs:
19034 @item delay-newmail
19035 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
19036 CHECK commands. Some clients ignore them otherwise, for example OSX
19037 Mail (<v2.1). Outlook Express breaks more badly though, without this it
19038 may show user "Message no longer in server" errors. Note that OE6
19039 still breaks even with this workaround if synchronization is set to
19042 @item tb-extra-mailbox-sep
19043 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
19044 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
19045 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
19047 @item tb-lsub-flags
19048 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
19049 This makes Thunderbird realize they aren't selectable and show them
19050 greyed out, instead of only later giving "not selectable" popup error.
19052 Defaults to @samp{()}.
19055 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
19056 Host allowed in URLAUTH URLs sent by client. "*" allows all.
19057 Defaults to @samp{""}.
19061 Whew! Lots of configuration options. The nice thing about it though is
19062 that Guix has a complete interface to Dovecot's configuration
19063 language. This allows not only a nice way to declare configurations,
19064 but also offers reflective capabilities as well: users can write code to
19065 inspect and transform configurations from within Scheme.
19067 However, it could be that you just want to get a @code{dovecot.conf} up
19068 and running. In that case, you can pass an
19069 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
19070 @code{dovecot-service}. As its name indicates, an opaque configuration
19071 does not have easy reflective capabilities.
19073 Available @code{opaque-dovecot-configuration} fields are:
19075 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
19076 The dovecot package.
19079 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
19080 The contents of the @code{dovecot.conf}, as a string.
19083 For example, if your @code{dovecot.conf} is just the empty string, you
19084 could instantiate a dovecot service like this:
19087 (dovecot-service #:config
19088 (opaque-dovecot-configuration
19092 @subsubheading OpenSMTPD Service
19094 @deffn {Scheme Variable} opensmtpd-service-type
19095 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
19096 service, whose value should be an @code{opensmtpd-configuration} object
19097 as in this example:
19100 (service opensmtpd-service-type
19101 (opensmtpd-configuration
19102 (config-file (local-file "./my-smtpd.conf"))))
19106 @deftp {Data Type} opensmtpd-configuration
19107 Data type representing the configuration of opensmtpd.
19110 @item @code{package} (default: @var{opensmtpd})
19111 Package object of the OpenSMTPD SMTP server.
19113 @item @code{config-file} (default: @code{%default-opensmtpd-file})
19114 File-like object of the OpenSMTPD configuration file to use. By default
19115 it listens on the loopback network interface, and allows for mail from
19116 users and daemons on the local machine, as well as permitting email to
19117 remote servers. Run @command{man smtpd.conf} for more information.
19122 @subsubheading Exim Service
19124 @cindex mail transfer agent (MTA)
19125 @cindex MTA (mail transfer agent)
19128 @deffn {Scheme Variable} exim-service-type
19129 This is the type of the @uref{https://exim.org, Exim} mail transfer
19130 agent (MTA), whose value should be an @code{exim-configuration} object
19131 as in this example:
19134 (service exim-service-type
19135 (exim-configuration
19136 (config-file (local-file "./my-exim.conf"))))
19140 In order to use an @code{exim-service-type} service you must also have a
19141 @code{mail-aliases-service-type} service present in your
19142 @code{operating-system} (even if it has no aliases).
19144 @deftp {Data Type} exim-configuration
19145 Data type representing the configuration of exim.
19148 @item @code{package} (default: @var{exim})
19149 Package object of the Exim server.
19151 @item @code{config-file} (default: @code{#f})
19152 File-like object of the Exim configuration file to use. If its value is
19153 @code{#f} then use the default configuration file from the package
19154 provided in @code{package}. The resulting configuration file is loaded
19155 after setting the @code{exim_user} and @code{exim_group} configuration
19161 @subsubheading Getmail service
19166 @deffn {Scheme Variable} getmail-service-type
19167 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
19168 mail retriever, whose value should be an @code{getmail-configuration}.
19171 Available @code{getmail-configuration} fields are:
19173 @deftypevr {@code{getmail-configuration} parameter} symbol name
19174 A symbol to identify the getmail service.
19176 Defaults to @samp{"unset"}.
19180 @deftypevr {@code{getmail-configuration} parameter} package package
19181 The getmail package to use.
19185 @deftypevr {@code{getmail-configuration} parameter} string user
19186 The user to run getmail as.
19188 Defaults to @samp{"getmail"}.
19192 @deftypevr {@code{getmail-configuration} parameter} string group
19193 The group to run getmail as.
19195 Defaults to @samp{"getmail"}.
19199 @deftypevr {@code{getmail-configuration} parameter} string directory
19200 The getmail directory to use.
19202 Defaults to @samp{"/var/lib/getmail/default"}.
19206 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
19207 The getmail configuration file to use.
19209 Available @code{getmail-configuration-file} fields are:
19211 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
19212 What mail account to retrieve mail from, and how to access that account.
19214 Available @code{getmail-retriever-configuration} fields are:
19216 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
19217 The type of mail retriever to use. Valid values include @samp{passwd}
19220 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
19224 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
19225 Username to login to the mail server with.
19227 Defaults to @samp{unset}.
19231 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
19232 Username to login to the mail server with.
19234 Defaults to @samp{unset}.
19238 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
19239 Port number to connect to.
19241 Defaults to @samp{#f}.
19245 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
19246 Override fields from passwd.
19248 Defaults to @samp{""}.
19252 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
19253 Override fields from passwd.
19255 Defaults to @samp{()}.
19259 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
19260 PEM-formatted key file to use for the TLS negotiation.
19262 Defaults to @samp{""}.
19266 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
19267 PEM-formatted certificate file to use for the TLS negotiation.
19269 Defaults to @samp{""}.
19273 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
19274 CA certificates to use.
19276 Defaults to @samp{""}.
19280 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
19281 Extra retriever parameters.
19283 Defaults to @samp{()}.
19289 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
19290 What to do with retrieved messages.
19292 Available @code{getmail-destination-configuration} fields are:
19294 @deftypevr {@code{getmail-destination-configuration} parameter} string type
19295 The type of mail destination. Valid values include @samp{Maildir},
19296 @samp{Mboxrd} and @samp{MDA_external}.
19298 Defaults to @samp{unset}.
19302 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
19303 The path option for the mail destination. The behaviour depends on the
19306 Defaults to @samp{""}.
19310 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
19311 Extra destination parameters
19313 Defaults to @samp{()}.
19319 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
19322 Available @code{getmail-options-configuration} fields are:
19324 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
19325 If set to @samp{0}, getmail will only print warnings and errors. A
19326 value of @samp{1} means that messages will be printed about retrieving
19327 and deleting messages. If set to @samp{2}, getmail will print messages
19328 about each of it's actions.
19330 Defaults to @samp{1}.
19334 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
19335 If true, getmail will retrieve all available messages. Otherwise it
19336 will only retrieve messages it hasn't seen previously.
19338 Defaults to @samp{#t}.
19342 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
19343 If set to true, messages will be deleted from the server after
19344 retrieving and successfully delivering them. Otherwise, messages will
19345 be left on the server.
19347 Defaults to @samp{#f}.
19351 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
19352 Getmail will delete messages this number of days after seeing them, if
19353 they have been delivered. This means messages will be left on the
19354 server this number of days after delivering them. A value of @samp{0}
19355 disabled this feature.
19357 Defaults to @samp{0}.
19361 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
19362 Delete messages larger than this of bytes after retrieving them, even if
19363 the delete and delete-after options are disabled. A value of @samp{0}
19364 disables this feature.
19366 Defaults to @samp{0}.
19370 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
19371 Retrieve messages totalling up to this number of bytes before closing
19372 the session with the server. A value of @samp{0} disables this feature.
19374 Defaults to @samp{0}.
19378 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
19379 Don't retrieve messages larger than this number of bytes. A value of
19380 @samp{0} disables this feature.
19382 Defaults to @samp{0}.
19386 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
19387 If true, getmail will add a Delivered-To header to messages.
19389 Defaults to @samp{#t}.
19393 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
19394 If set, getmail adds a Received header to the messages.
19396 Defaults to @samp{#t}.
19400 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
19401 Getmail will record a log of its actions to the named file. A value of
19402 @samp{""} disables this feature.
19404 Defaults to @samp{""}.
19408 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
19409 If true, getmail will record a log of its actions using the system
19412 Defaults to @samp{#f}.
19416 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
19417 If true, getmail will log information about messages not retrieved and
19418 the reason for not retrieving them, as well as starting and ending
19421 Defaults to @samp{#f}.
19425 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
19426 Extra options to include.
19428 Defaults to @samp{()}.
19436 @deftypevr {@code{getmail-configuration} parameter} list idle
19437 A list of mailboxes that getmail should wait on the server for new mail
19438 notifications. This depends on the server supporting the IDLE
19441 Defaults to @samp{()}.
19445 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
19446 Environment variables to set for getmail.
19448 Defaults to @samp{()}.
19452 @subsubheading Mail Aliases Service
19454 @cindex email aliases
19455 @cindex aliases, for email addresses
19457 @deffn {Scheme Variable} mail-aliases-service-type
19458 This is the type of the service which provides @code{/etc/aliases},
19459 specifying how to deliver mail to users on this system.
19462 (service mail-aliases-service-type
19463 '(("postmaster" "bob")
19464 ("bob" "bob@@example.com" "bob@@example2.com")))
19468 The configuration for a @code{mail-aliases-service-type} service is an
19469 association list denoting how to deliver mail that comes to this
19470 system. Each entry is of the form @code{(alias addresses ...)}, with
19471 @code{alias} specifying the local alias and @code{addresses} specifying
19472 where to deliver this user's mail.
19474 The aliases aren't required to exist as users on the local system. In
19475 the above example, there doesn't need to be a @code{postmaster} entry in
19476 the @code{operating-system}'s @code{user-accounts} in order to deliver
19477 the @code{postmaster} mail to @code{bob} (which subsequently would
19478 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
19480 @subsubheading GNU Mailutils IMAP4 Daemon
19481 @cindex GNU Mailutils IMAP4 Daemon
19483 @deffn {Scheme Variable} imap4d-service-type
19484 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
19485 mailutils, GNU Mailutils Manual}), whose value should be an
19486 @code{imap4d-configuration} object as in this example:
19489 (service imap4d-service-type
19490 (imap4d-configuration
19491 (config-file (local-file "imap4d.conf"))))
19495 @deftp {Data Type} imap4d-configuration
19496 Data type representing the configuration of @command{imap4d}.
19499 @item @code{package} (default: @code{mailutils})
19500 The package that provides @command{imap4d}.
19502 @item @code{config-file} (default: @code{%default-imap4d-config-file})
19503 File-like object of the configuration file to use, by default it will listen
19504 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
19505 Mailutils Manual}, for details.
19510 @node Messaging Services
19511 @subsection Messaging Services
19516 The @code{(gnu services messaging)} module provides Guix service
19517 definitions for messaging services: currently only Prosody is supported.
19519 @subsubheading Prosody Service
19521 @deffn {Scheme Variable} prosody-service-type
19522 This is the type for the @uref{https://prosody.im, Prosody XMPP
19523 communication server}. Its value must be a @code{prosody-configuration}
19524 record as in this example:
19527 (service prosody-service-type
19528 (prosody-configuration
19529 (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
19532 (int-component-configuration
19533 (hostname "conference.example.net")
19535 (mod-muc (mod-muc-configuration)))))
19538 (virtualhost-configuration
19539 (domain "example.net"))))))
19542 See below for details about @code{prosody-configuration}.
19546 By default, Prosody does not need much configuration. Only one
19547 @code{virtualhosts} field is needed: it specifies the domain you wish
19550 You can perform various sanity checks on the generated configuration
19551 with the @code{prosodyctl check} command.
19553 Prosodyctl will also help you to import certificates from the
19554 @code{letsencrypt} directory so that the @code{prosody} user can access
19555 them. See @url{https://prosody.im/doc/letsencrypt}.
19558 prosodyctl --root cert import /etc/letsencrypt/live
19561 The available configuration parameters follow. Each parameter
19562 definition is preceded by its type; for example, @samp{string-list foo}
19563 indicates that the @code{foo} parameter should be specified as a list of
19564 strings. Types starting with @code{maybe-} denote parameters that won't
19565 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
19567 There is also a way to specify the configuration as a string, if you
19568 have an old @code{prosody.cfg.lua} file that you want to port over from
19569 some other system; see the end for more details.
19571 The @code{file-object} type designates either a file-like object
19572 (@pxref{G-Expressions, file-like objects}) or a file name.
19574 @c The following documentation was initially generated by
19575 @c (generate-documentation) in (gnu services messaging). Manually maintained
19576 @c documentation is better, so we shouldn't hesitate to edit below as
19577 @c needed. However if the change you want to make to this documentation
19578 @c can be done in an automated way, it's probably easier to change
19579 @c (generate-documentation) than to make it below and have to deal with
19580 @c the churn as Prosody updates.
19582 Available @code{prosody-configuration} fields are:
19584 @deftypevr {@code{prosody-configuration} parameter} package prosody
19585 The Prosody package.
19588 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
19589 Location of the Prosody data storage directory. See
19590 @url{https://prosody.im/doc/configure}.
19591 Defaults to @samp{"/var/lib/prosody"}.
19594 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
19595 Additional plugin directories. They are searched in all the specified
19596 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
19597 Defaults to @samp{()}.
19600 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
19601 Every virtual host and component needs a certificate so that clients and
19602 servers can securely verify its identity. Prosody will automatically load
19603 certificates/keys from the directory specified here.
19604 Defaults to @samp{"/etc/prosody/certs"}.
19607 @deftypevr {@code{prosody-configuration} parameter} string-list admins
19608 This is a list of accounts that are admins for the server. Note that you
19609 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
19610 @url{https://prosody.im/doc/creating_accounts}.
19611 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
19612 Defaults to @samp{()}.
19615 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
19616 Enable use of libevent for better performance under high load. See
19617 @url{https://prosody.im/doc/libevent}.
19618 Defaults to @samp{#f}.
19621 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
19622 This is the list of modules Prosody will load on startup. It looks for
19623 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
19624 Documentation on modules can be found at:
19625 @url{https://prosody.im/doc/modules}.
19626 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
19629 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
19630 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
19631 should you want to disable them then add them to this list.
19632 Defaults to @samp{()}.
19635 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
19636 Path to a text file where the shared groups are defined. If this path is
19637 empty then @samp{mod_groups} does nothing. See
19638 @url{https://prosody.im/doc/modules/mod_groups}.
19639 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
19642 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
19643 Disable account creation by default, for security. See
19644 @url{https://prosody.im/doc/creating_accounts}.
19645 Defaults to @samp{#f}.
19648 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
19649 These are the SSL/TLS-related settings. Most of them are disabled so to
19650 use Prosody's defaults. If you do not completely understand these options, do
19651 not add them to your config, it is easy to lower the security of your server
19652 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
19654 Available @code{ssl-configuration} fields are:
19656 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
19657 This determines what handshake to use.
19660 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
19661 Path to your private key file.
19664 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
19665 Path to your certificate file.
19668 @deftypevr {@code{ssl-configuration} parameter} file-object capath
19669 Path to directory containing root certificates that you wish Prosody to
19670 trust when verifying the certificates of remote servers.
19671 Defaults to @samp{"/etc/ssl/certs"}.
19674 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
19675 Path to a file containing root certificates that you wish Prosody to trust.
19676 Similar to @code{capath} but with all certificates concatenated together.
19679 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
19680 A list of verification options (these mostly map to OpenSSL's
19681 @code{set_verify()} flags).
19684 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
19685 A list of general options relating to SSL/TLS. These map to OpenSSL's
19686 @code{set_options()}. For a full list of options available in LuaSec, see the
19690 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
19691 How long a chain of certificate authorities to check when looking for a
19692 trusted root certificate.
19695 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
19696 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
19697 clients, and in what order.
19700 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
19701 A path to a file containing parameters for Diffie-Hellman key exchange. You
19702 can create such a file with:
19703 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
19706 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
19707 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
19708 @samp{"secp384r1"}.
19711 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
19712 A list of ``extra'' verification options.
19715 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
19716 Password for encrypted private keys.
19721 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
19722 Whether to force all client-to-server connections to be encrypted or not.
19723 See @url{https://prosody.im/doc/modules/mod_tls}.
19724 Defaults to @samp{#f}.
19727 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
19728 Set of mechanisms that will never be offered. See
19729 @url{https://prosody.im/doc/modules/mod_saslauth}.
19730 Defaults to @samp{("DIGEST-MD5")}.
19733 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
19734 Whether to force all server-to-server connections to be encrypted or not.
19735 See @url{https://prosody.im/doc/modules/mod_tls}.
19736 Defaults to @samp{#f}.
19739 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
19740 Whether to require encryption and certificate authentication. This
19741 provides ideal security, but requires servers you communicate with to support
19742 encryption AND present valid, trusted certificates. See
19743 @url{https://prosody.im/doc/s2s#security}.
19744 Defaults to @samp{#f}.
19747 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
19748 Many servers don't support encryption or have invalid or self-signed
19749 certificates. You can list domains here that will not be required to
19750 authenticate using certificates. They will be authenticated using DNS. See
19751 @url{https://prosody.im/doc/s2s#security}.
19752 Defaults to @samp{()}.
19755 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
19756 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
19757 valid certificates for some domains by specifying a list here. See
19758 @url{https://prosody.im/doc/s2s#security}.
19759 Defaults to @samp{()}.
19762 @deftypevr {@code{prosody-configuration} parameter} string authentication
19763 Select the authentication backend to use. The default provider stores
19764 passwords in plaintext and uses Prosody's configured data storage to store the
19765 authentication data. If you do not trust your server please see
19766 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
19767 about using the hashed backend. See also
19768 @url{https://prosody.im/doc/authentication}
19769 Defaults to @samp{"internal_plain"}.
19772 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
19773 Set logging options. Advanced logging configuration is not yet supported
19774 by the Prosody service. See @url{https://prosody.im/doc/logging}.
19775 Defaults to @samp{"*syslog"}.
19778 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
19779 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
19780 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
19783 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
19784 Maximum allowed size of the HTTP body (in bytes).
19787 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
19788 Some modules expose their own URL in various ways. This URL is built
19789 from the protocol, host and port used. If Prosody sits behind a proxy, the
19790 public URL will be @code{http-external-url} instead. See
19791 @url{https://prosody.im/doc/http#external_url}.
19794 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
19795 A host in Prosody is a domain on which user accounts can be created. For
19796 example if you want your users to have addresses like
19797 @samp{"john.smith@@example.com"} then you need to add a host
19798 @samp{"example.com"}. All options in this list will apply only to this host.
19800 Note: the name @emph{virtual} host is used in configuration to avoid confusion with
19801 the actual physical host that Prosody is installed on. A single Prosody
19802 instance can serve many domains, each one defined as a VirtualHost entry in
19803 Prosody's configuration. Conversely a server that hosts a single domain would
19804 have just one VirtualHost entry.
19806 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
19808 Available @code{virtualhost-configuration} fields are:
19810 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:
19811 @deftypevr {@code{virtualhost-configuration} parameter} string domain
19812 Domain you wish Prosody to serve.
19817 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
19818 Components are extra services on a server which are available to clients,
19819 usually on a subdomain of the main server (such as
19820 @samp{"mycomponent.example.com"}). Example components might be chatroom
19821 servers, user directories, or gateways to other protocols.
19823 Internal components are implemented with Prosody-specific plugins. To add an
19824 internal component, you simply fill the hostname field, and the plugin you wish
19825 to use for the component.
19827 See @url{https://prosody.im/doc/components}.
19828 Defaults to @samp{()}.
19830 Available @code{int-component-configuration} fields are:
19832 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:
19833 @deftypevr {@code{int-component-configuration} parameter} string hostname
19834 Hostname of the component.
19837 @deftypevr {@code{int-component-configuration} parameter} string plugin
19838 Plugin you wish to use for the component.
19841 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
19842 Multi-user chat (MUC) is Prosody's module for allowing you to create
19843 hosted chatrooms/conferences for XMPP users.
19845 General information on setting up and using multi-user chatrooms can be found
19846 in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
19847 which you should read if you are new to XMPP chatrooms.
19849 See also @url{https://prosody.im/doc/modules/mod_muc}.
19851 Available @code{mod-muc-configuration} fields are:
19853 @deftypevr {@code{mod-muc-configuration} parameter} string name
19854 The name to return in service discovery responses.
19855 Defaults to @samp{"Prosody Chatrooms"}.
19858 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
19859 If @samp{#t}, this will only allow admins to create new chatrooms.
19860 Otherwise anyone can create a room. The value @samp{"local"} restricts room
19861 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
19862 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
19863 restricts to service administrators only.
19864 Defaults to @samp{#f}.
19867 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
19868 Maximum number of history messages that will be sent to the member that has
19869 just joined the room.
19870 Defaults to @samp{20}.
19877 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
19878 External components use XEP-0114, which most standalone components
19879 support. To add an external component, you simply fill the hostname field. See
19880 @url{https://prosody.im/doc/components}.
19881 Defaults to @samp{()}.
19883 Available @code{ext-component-configuration} fields are:
19885 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:
19886 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
19887 Password which the component will use to log in.
19890 @deftypevr {@code{ext-component-configuration} parameter} string hostname
19891 Hostname of the component.
19896 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
19897 Port(s) Prosody listens on for component connections.
19898 Defaults to @samp{(5347)}.
19901 @deftypevr {@code{prosody-configuration} parameter} string component-interface
19902 Interface Prosody listens on for component connections.
19903 Defaults to @samp{"127.0.0.1"}.
19906 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
19907 Raw content that will be added to the configuration file.
19910 It could be that you just want to get a @code{prosody.cfg.lua}
19911 up and running. In that case, you can pass an
19912 @code{opaque-prosody-configuration} record as the value of
19913 @code{prosody-service-type}. As its name indicates, an opaque configuration
19914 does not have easy reflective capabilities.
19915 Available @code{opaque-prosody-configuration} fields are:
19917 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
19918 The prosody package.
19921 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
19922 The contents of the @code{prosody.cfg.lua} to use.
19925 For example, if your @code{prosody.cfg.lua} is just the empty
19926 string, you could instantiate a prosody service like this:
19929 (service prosody-service-type
19930 (opaque-prosody-configuration
19931 (prosody.cfg.lua "")))
19934 @c end of Prosody auto-generated documentation
19936 @subsubheading BitlBee Service
19938 @cindex IRC (Internet Relay Chat)
19939 @cindex IRC gateway
19940 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
19941 interface to a variety of messaging protocols such as XMPP.
19943 @defvr {Scheme Variable} bitlbee-service-type
19944 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
19945 gateway daemon. Its value is a @code{bitlbee-configuration} (see
19948 To have BitlBee listen on port 6667 on localhost, add this line to your
19952 (service bitlbee-service-type)
19956 @deftp {Data Type} bitlbee-configuration
19957 This is the configuration for BitlBee, with the following fields:
19960 @item @code{interface} (default: @code{"127.0.0.1"})
19961 @itemx @code{port} (default: @code{6667})
19962 Listen on the network interface corresponding to the IP address
19963 specified in @var{interface}, on @var{port}.
19965 When @var{interface} is @code{127.0.0.1}, only local clients can
19966 connect; when it is @code{0.0.0.0}, connections can come from any
19967 networking interface.
19969 @item @code{bitlbee} (default: @code{bitlbee})
19970 The BitlBee package to use.
19972 @item @code{plugins} (default: @code{'()})
19973 List of plugin packages to use---e.g., @code{bitlbee-discord}.
19975 @item @code{extra-settings} (default: @code{""})
19976 Configuration snippet added as-is to the BitlBee configuration file.
19980 @subsubheading Quassel Service
19982 @cindex IRC (Internet Relay Chat)
19983 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
19984 meaning that one or more clients can attach to and detach from the
19987 @defvr {Scheme Variable} quassel-service-type
19988 This is the service type for the @url{https://quassel-irc.org/,Quassel}
19989 IRC backend daemon. Its value is a @code{quassel-configuration}
19993 @deftp {Data Type} quassel-configuration
19994 This is the configuration for Quassel, with the following fields:
19997 @item @code{quassel} (default: @code{quassel})
19998 The Quassel package to use.
20000 @item @code{interface} (default: @code{"::,0.0.0.0"})
20001 @item @code{port} (default: @code{4242})
20002 Listen on the network interface(s) corresponding to the IPv4 or IPv6
20003 interfaces specified in the comma delimited @var{interface}, on
20006 @item @code{loglevel} (default: @code{"Info"})
20007 The level of logging desired. Accepted values are Debug, Info, Warning
20012 @node Telephony Services
20013 @subsection Telephony Services
20015 @cindex Murmur (VoIP server)
20016 @cindex VoIP server
20017 This section describes how to set up and run a Murmur server. Murmur is
20018 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
20021 @deftp {Data Type} murmur-configuration
20022 The service type for the Murmur server. An example configuration can
20026 (service murmur-service-type
20027 (murmur-configuration
20029 "Welcome to this Mumble server running on Guix!")
20030 (cert-required? #t) ;disallow text password logins
20031 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
20032 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
20035 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
20036 password with the command that is printed during the activation phase.
20038 It is recommended to register a normal Mumble user account
20039 and grant it admin or moderator rights.
20040 You can use the @code{mumble} client to
20041 login as new normal user, register yourself, and log out.
20042 For the next step login with the name @code{SuperUser} use
20043 the @code{SuperUser} password that you set previously,
20044 and grant your newly registered mumble user administrator or moderator
20045 rights and create some channels.
20047 Available @code{murmur-configuration} fields are:
20050 @item @code{package} (default: @code{mumble})
20051 Package that contains @code{bin/murmurd}.
20053 @item @code{user} (default: @code{"murmur"})
20054 User who will run the Murmur server.
20056 @item @code{group} (default: @code{"murmur"})
20057 Group of the user who will run the murmur server.
20059 @item @code{port} (default: @code{64738})
20060 Port on which the server will listen.
20062 @item @code{welcome-text} (default: @code{""})
20063 Welcome text sent to clients when they connect.
20065 @item @code{server-password} (default: @code{""})
20066 Password the clients have to enter in order to connect.
20068 @item @code{max-users} (default: @code{100})
20069 Maximum of users that can be connected to the server at once.
20071 @item @code{max-user-bandwidth} (default: @code{#f})
20072 Maximum voice traffic a user can send per second.
20074 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
20075 File name of the sqlite database.
20076 The service's user will become the owner of the directory.
20078 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
20079 File name of the log file.
20080 The service's user will become the owner of the directory.
20082 @item @code{autoban-attempts} (default: @code{10})
20083 Maximum number of logins a user can make in @code{autoban-timeframe}
20084 without getting auto banned for @code{autoban-time}.
20086 @item @code{autoban-timeframe} (default: @code{120})
20087 Timeframe for autoban in seconds.
20089 @item @code{autoban-time} (default: @code{300})
20090 Amount of time in seconds for which a client gets banned
20091 when violating the autoban limits.
20093 @item @code{opus-threshold} (default: @code{100})
20094 Percentage of clients that need to support opus
20095 before switching over to opus audio codec.
20097 @item @code{channel-nesting-limit} (default: @code{10})
20098 How deep channels can be nested at maximum.
20100 @item @code{channelname-regex} (default: @code{#f})
20101 A string in form of a Qt regular expression that channel names must conform to.
20103 @item @code{username-regex} (default: @code{#f})
20104 A string in form of a Qt regular expression that user names must conform to.
20106 @item @code{text-message-length} (default: @code{5000})
20107 Maximum size in bytes that a user can send in one text chat message.
20109 @item @code{image-message-length} (default: @code{(* 128 1024)})
20110 Maximum size in bytes that a user can send in one image message.
20112 @item @code{cert-required?} (default: @code{#f})
20113 If it is set to @code{#t} clients that use weak password authentication
20114 will not be accepted. Users must have completed the certificate wizard to join.
20116 @item @code{remember-channel?} (default: @code{#f})
20117 Should murmur remember the last channel each user was in when they disconnected
20118 and put them into the remembered channel when they rejoin.
20120 @item @code{allow-html?} (default: @code{#f})
20121 Should html be allowed in text messages, user comments, and channel descriptions.
20123 @item @code{allow-ping?} (default: @code{#f})
20124 Setting to true exposes the current user count, the maximum user count, and
20125 the server's maximum bandwidth per client to unauthenticated users. In the
20126 Mumble client, this information is shown in the Connect dialog.
20128 Disabling this setting will prevent public listing of the server.
20130 @item @code{bonjour?} (default: @code{#f})
20131 Should the server advertise itself in the local network through the bonjour protocol.
20133 @item @code{send-version?} (default: @code{#f})
20134 Should the murmur server version be exposed in ping requests.
20136 @item @code{log-days} (default: @code{31})
20137 Murmur also stores logs in the database, which are accessible via RPC.
20138 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
20139 or -1 to disable logging to the database.
20141 @item @code{obfuscate-ips?} (default: @code{#t})
20142 Should logged ips be obfuscated to protect the privacy of users.
20144 @item @code{ssl-cert} (default: @code{#f})
20145 File name of the SSL/TLS certificate used for encrypted connections.
20148 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
20150 @item @code{ssl-key} (default: @code{#f})
20151 Filepath to the ssl private key used for encrypted connections.
20153 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
20156 @item @code{ssl-dh-params} (default: @code{#f})
20157 File name of a PEM-encoded file with Diffie-Hellman parameters
20158 for the SSL/TLS encryption. Alternatively you set it to
20159 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
20160 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
20162 @item @code{ssl-ciphers} (default: @code{#f})
20163 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
20166 This option is specified using
20167 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
20168 OpenSSL cipher list notation}.
20170 It is recommended that you try your cipher string using 'openssl ciphers <string>'
20171 before setting it here, to get a feel for which cipher suites you will get.
20172 After setting this option, it is recommend that you inspect your Murmur log
20173 to ensure that Murmur is using the cipher suites that you expected it to.
20175 Note: Changing this option may impact the backwards compatibility of your
20176 Murmur server, and can remove the ability for older Mumble clients to be able
20179 @item @code{public-registration} (default: @code{#f})
20180 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
20182 You can optionally register your server in the public server list that the
20183 @code{mumble} client shows on startup.
20184 You cannot register your server if you have set a @code{server-password},
20185 or set @code{allow-ping} to @code{#f}.
20187 It might take a few hours until it shows up in the public list.
20189 @item @code{file} (default: @code{#f})
20190 Optional alternative override for this configuration.
20194 @deftp {Data Type} murmur-public-registration-configuration
20195 Configuration for public registration of a murmur service.
20199 This is a display name for your server. Not to be confused with the hostname.
20201 @item @code{password}
20202 A password to identify your registration.
20203 Subsequent updates will need the same password. Don't lose your password.
20206 This should be a @code{http://} or @code{https://} link to your web
20209 @item @code{hostname} (default: @code{#f})
20210 By default your server will be listed by its IP address.
20211 If it is set your server will be linked by this host name instead.
20217 @node Monitoring Services
20218 @subsection Monitoring Services
20220 @subsubheading Tailon Service
20222 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
20223 viewing and searching log files.
20225 The following example will configure the service with default values.
20226 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
20229 (service tailon-service-type)
20232 The following example customises more of the Tailon configuration,
20233 adding @command{sed} to the list of allowed commands.
20236 (service tailon-service-type
20237 (tailon-configuration
20239 (tailon-configuration-file
20240 (allowed-commands '("tail" "grep" "awk" "sed"))))))
20244 @deftp {Data Type} tailon-configuration
20245 Data type representing the configuration of Tailon.
20246 This type has the following parameters:
20249 @item @code{config-file} (default: @code{(tailon-configuration-file)})
20250 The configuration file to use for Tailon. This can be set to a
20251 @dfn{tailon-configuration-file} record value, or any gexp
20252 (@pxref{G-Expressions}).
20254 For example, to instead use a local file, the @code{local-file} function
20258 (service tailon-service-type
20259 (tailon-configuration
20260 (config-file (local-file "./my-tailon.conf"))))
20263 @item @code{package} (default: @code{tailon})
20264 The tailon package to use.
20269 @deftp {Data Type} tailon-configuration-file
20270 Data type representing the configuration options for Tailon.
20271 This type has the following parameters:
20274 @item @code{files} (default: @code{(list "/var/log")})
20275 List of files to display. The list can include strings for a single file
20276 or directory, or a list, where the first item is the name of a
20277 subsection, and the remaining items are the files or directories in that
20280 @item @code{bind} (default: @code{"localhost:8080"})
20281 Address and port to which Tailon should bind on.
20283 @item @code{relative-root} (default: @code{#f})
20284 URL path to use for Tailon, set to @code{#f} to not use a path.
20286 @item @code{allow-transfers?} (default: @code{#t})
20287 Allow downloading the log files in the web interface.
20289 @item @code{follow-names?} (default: @code{#t})
20290 Allow tailing of not-yet existent files.
20292 @item @code{tail-lines} (default: @code{200})
20293 Number of lines to read initially from each file.
20295 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
20296 Commands to allow running. By default, @code{sed} is disabled.
20298 @item @code{debug?} (default: @code{#f})
20299 Set @code{debug?} to @code{#t} to show debug messages.
20301 @item @code{wrap-lines} (default: @code{#t})
20302 Initial line wrapping state in the web interface. Set to @code{#t} to
20303 initially wrap lines (the default), or to @code{#f} to initially not
20306 @item @code{http-auth} (default: @code{#f})
20307 HTTP authentication type to use. Set to @code{#f} to disable
20308 authentication (the default). Supported values are @code{"digest"} or
20311 @item @code{users} (default: @code{#f})
20312 If HTTP authentication is enabled (see @code{http-auth}), access will be
20313 restricted to the credentials provided here. To configure users, use a
20314 list of pairs, where the first element of the pair is the username, and
20315 the 2nd element of the pair is the password.
20318 (tailon-configuration-file
20319 (http-auth "basic")
20320 (users '(("user1" . "password1")
20321 ("user2" . "password2"))))
20328 @subsubheading Darkstat Service
20330 Darkstat is a packet sniffer that captures network traffic, calculates
20331 statistics about usage, and serves reports over HTTP.
20333 @defvar {Scheme Variable} darkstat-service-type
20334 This is the service type for the
20335 @uref{https://unix4lyfe.org/darkstat/, darkstat}
20336 service, its value must be a @code{darkstat-configuration} record as in
20340 (service darkstat-service-type
20341 (darkstat-configuration
20342 (interface "eno1")))
20346 @deftp {Data Type} darkstat-configuration
20347 Data type representing the configuration of @command{darkstat}.
20350 @item @code{package} (default: @code{darkstat})
20351 The darkstat package to use.
20353 @item @code{interface}
20354 Capture traffic on the specified network interface.
20356 @item @code{port} (default: @code{"667"})
20357 Bind the web interface to the specified port.
20359 @item @code{bind-address} (default: @code{"127.0.0.1"})
20360 Bind the web interface to the specified address.
20362 @item @code{base} (default: @code{"/"})
20363 Specify the path of the base URL. This can be useful if
20364 @command{darkstat} is accessed via a reverse proxy.
20369 @subsubheading Prometheus Node Exporter Service
20371 @cindex prometheus-node-exporter
20372 The Prometheus ``node exporter'' makes hardware and operating system statistics
20373 provided by the Linux kernel available for the Prometheus monitoring system.
20374 This service should be deployed on all physical nodes and virtual machines,
20375 where monitoring these statistics is desirable.
20377 @defvar {Scheme variable} prometheus-node-exporter-service-type
20378 This is the service type for the
20379 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
20380 service, its value must be a @code{prometheus-node-exporter-configuration}
20381 record as in this example:
20384 (service prometheus-node-exporter-service-type
20385 (prometheus-node-exporter-configuration
20386 (web-listen-address ":9100")))
20390 @deftp {Data Type} prometheus-node-exporter-configuration
20391 Data type representing the configuration of @command{node_exporter}.
20394 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
20395 The prometheus-node-exporter package to use.
20397 @item @code{web-listen-address} (default: @code{":9100"})
20398 Bind the web interface to the specified address.
20403 @subsubheading Zabbix server
20404 @cindex zabbix zabbix-server
20405 Zabbix provides monitoring metrics, among others network utilization, CPU load
20406 and disk space consumption:
20409 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
20410 @item Auto-discovery of servers and network devices and interfaces.
20411 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
20412 @item Distributed monitoring with centralized web administration.
20413 @item Native high performance agents.
20414 @item SLA, and ITIL KPI metrics on reporting.
20415 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
20416 @item Remote command execution through Zabbix proxies.
20419 @c %start of fragment
20421 Available @code{zabbix-server-configuration} fields are:
20423 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
20424 The zabbix-server package.
20428 @deftypevr {@code{zabbix-server-configuration} parameter} string user
20429 User who will run the Zabbix server.
20431 Defaults to @samp{"zabbix"}.
20435 @deftypevr {@code{zabbix-server-configuration} parameter} group group
20436 Group who will run the Zabbix server.
20438 Defaults to @samp{"zabbix"}.
20442 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
20443 Database host name.
20445 Defaults to @samp{"127.0.0.1"}.
20449 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
20452 Defaults to @samp{"zabbix"}.
20456 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
20459 Defaults to @samp{"zabbix"}.
20463 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
20464 Database password. Please, use @code{include-files} with
20465 @code{DBPassword=SECRET} inside a specified file instead.
20467 Defaults to @samp{""}.
20471 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
20474 Defaults to @samp{5432}.
20478 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
20479 Specifies where log messages are written to:
20483 @code{system} - syslog.
20486 @code{file} - file specified with @code{log-file} parameter.
20489 @code{console} - standard output.
20493 Defaults to @samp{""}.
20497 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
20498 Log file name for @code{log-type} @code{file} parameter.
20500 Defaults to @samp{"/var/log/zabbix/server.log"}.
20504 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
20507 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
20511 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
20512 The location of certificate authority (CA) files for SSL server
20513 certificate verification.
20515 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
20519 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
20520 Location of SSL client certificates.
20522 Defaults to @samp{"/etc/ssl/certs"}.
20526 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
20527 Extra options will be appended to Zabbix server configuration file.
20529 Defaults to @samp{""}.
20533 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
20534 You may include individual files or all files in a directory in the
20535 configuration file.
20537 Defaults to @samp{()}.
20541 @c %end of fragment
20543 @subsubheading Zabbix agent
20544 @cindex zabbix zabbix-agent
20546 Zabbix agent gathers information for Zabbix server.
20548 @c %start of fragment
20550 Available @code{zabbix-agent-configuration} fields are:
20552 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
20553 The zabbix-agent package.
20557 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
20558 User who will run the Zabbix agent.
20560 Defaults to @samp{"zabbix"}.
20564 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
20565 Group who will run the Zabbix agent.
20567 Defaults to @samp{"zabbix"}.
20571 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
20572 Unique, case sensitive hostname which is required for active checks and
20573 must match hostname as configured on the server.
20575 Defaults to @samp{"Zabbix server"}.
20579 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
20580 Specifies where log messages are written to:
20584 @code{system} - syslog.
20587 @code{file} - file specified with @code{log-file} parameter.
20590 @code{console} - standard output.
20594 Defaults to @samp{""}.
20598 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
20599 Log file name for @code{log-type} @code{file} parameter.
20601 Defaults to @samp{"/var/log/zabbix/agent.log"}.
20605 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
20608 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
20612 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
20613 List of IP addresses, optionally in CIDR notation, or hostnames of
20614 Zabbix servers and Zabbix proxies. Incoming connections will be
20615 accepted only from the hosts listed here.
20617 Defaults to @samp{("127.0.0.1")}.
20621 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
20622 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
20623 proxies for active checks. If port is not specified, default port is
20624 used. If this parameter is not specified, active checks are disabled.
20626 Defaults to @samp{("127.0.0.1")}.
20630 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
20631 Extra options will be appended to Zabbix server configuration file.
20633 Defaults to @samp{""}.
20637 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
20638 You may include individual files or all files in a directory in the
20639 configuration file.
20641 Defaults to @samp{()}.
20645 @c %end of fragment
20647 @subsubheading Zabbix front-end
20648 @cindex zabbix zabbix-front-end
20650 This service provides a WEB interface to Zabbix server.
20652 @c %start of fragment
20654 Available @code{zabbix-front-end-configuration} fields are:
20656 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
20657 NGINX configuration.
20661 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
20662 Database host name.
20664 Defaults to @samp{"localhost"}.
20668 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
20671 Defaults to @samp{5432}.
20675 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
20678 Defaults to @samp{"zabbix"}.
20682 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
20685 Defaults to @samp{"zabbix"}.
20689 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
20690 Database password. Please, use @code{db-secret-file} instead.
20692 Defaults to @samp{""}.
20696 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
20697 Secret file which will be appended to @file{zabbix.conf.php} file. This
20698 file contains credentials for use by Zabbix front-end. You are expected
20699 to create it manually.
20701 Defaults to @samp{""}.
20705 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
20706 Zabbix server hostname.
20708 Defaults to @samp{"localhost"}.
20712 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
20713 Zabbix server port.
20715 Defaults to @samp{10051}.
20720 @c %end of fragment
20722 @node Kerberos Services
20723 @subsection Kerberos Services
20726 The @code{(gnu services kerberos)} module provides services relating to
20727 the authentication protocol @dfn{Kerberos}.
20729 @subsubheading Krb5 Service
20731 Programs using a Kerberos client library normally
20732 expect a configuration file in @file{/etc/krb5.conf}.
20733 This service generates such a file from a definition provided in the
20734 operating system declaration.
20735 It does not cause any daemon to be started.
20737 No ``keytab'' files are provided by this service---you must explicitly create them.
20738 This service is known to work with the MIT client library, @code{mit-krb5}.
20739 Other implementations have not been tested.
20741 @defvr {Scheme Variable} krb5-service-type
20742 A service type for Kerberos 5 clients.
20746 Here is an example of its use:
20748 (service krb5-service-type
20749 (krb5-configuration
20750 (default-realm "EXAMPLE.COM")
20751 (allow-weak-crypto? #t)
20754 (name "EXAMPLE.COM")
20755 (admin-server "groucho.example.com")
20756 (kdc "karl.example.com"))
20759 (admin-server "kerb-admin.argrx.edu")
20760 (kdc "keys.argrx.edu"))))))
20764 This example provides a Kerberos@tie{}5 client configuration which:
20766 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
20767 of which have distinct administration servers and key distribution centers;
20768 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
20769 specified by clients;
20770 @item Accepts services which only support encryption types known to be weak.
20773 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
20774 Only the most commonly used ones are described here.
20775 For a full list, and more detailed explanation of each, see the MIT
20776 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
20780 @deftp {Data Type} krb5-realm
20781 @cindex realm, kerberos
20784 This field is a string identifying the name of the realm.
20785 A common convention is to use the fully qualified DNS name of your organization,
20786 converted to upper case.
20788 @item @code{admin-server}
20789 This field is a string identifying the host where the administration server is
20793 This field is a string identifying the key distribution center
20798 @deftp {Data Type} krb5-configuration
20801 @item @code{allow-weak-crypto?} (default: @code{#f})
20802 If this flag is @code{#t} then services which only offer encryption algorithms
20803 known to be weak will be accepted.
20805 @item @code{default-realm} (default: @code{#f})
20806 This field should be a string identifying the default Kerberos
20807 realm for the client.
20808 You should set this field to the name of your Kerberos realm.
20809 If this value is @code{#f}
20810 then a realm must be specified with every Kerberos principal when invoking programs
20811 such as @command{kinit}.
20813 @item @code{realms}
20814 This should be a non-empty list of @code{krb5-realm} objects, which clients may
20816 Normally, one of them will have a @code{name} field matching the @code{default-realm}
20822 @subsubheading PAM krb5 Service
20825 The @code{pam-krb5} service allows for login authentication and password
20826 management via Kerberos.
20827 You will need this service if you want PAM enabled applications to authenticate
20828 users using Kerberos.
20830 @defvr {Scheme Variable} pam-krb5-service-type
20831 A service type for the Kerberos 5 PAM module.
20834 @deftp {Data Type} pam-krb5-configuration
20835 Data type representing the configuration of the Kerberos 5 PAM module.
20836 This type has the following parameters:
20838 @item @code{pam-krb5} (default: @code{pam-krb5})
20839 The pam-krb5 package to use.
20841 @item @code{minimum-uid} (default: @code{1000})
20842 The smallest user ID for which Kerberos authentications should be attempted.
20843 Local accounts with lower values will silently fail to authenticate.
20848 @node LDAP Services
20849 @subsection LDAP Services
20851 @cindex nslcd, LDAP service
20853 The @code{(gnu services authentication)} module provides the
20854 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
20855 server. In addition to configuring the service itself, you may want to add
20856 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
20857 Switch} for detailed information.
20859 Here is a simple operating system declaration with a default configuration of
20860 the @code{nslcd-service-type} and a Name Service Switch configuration that
20861 consults the @code{ldap} name service last:
20864 (use-service-modules authentication)
20865 (use-modules (gnu system nss))
20871 (service nslcd-service-type)
20872 (service dhcp-client-service-type)
20874 (name-service-switch
20875 (let ((services (list (name-service (name "db"))
20876 (name-service (name "files"))
20877 (name-service (name "ldap")))))
20878 (name-service-switch
20879 (inherit %mdns-host-lookup-nss)
20880 (password services)
20883 (netgroup services)
20884 (gshadow services)))))
20887 @c %start of generated documentation for nslcd-configuration
20889 Available @code{nslcd-configuration} fields are:
20891 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
20892 The @code{nss-pam-ldapd} package to use.
20896 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
20897 The number of threads to start that can handle requests and perform LDAP
20898 queries. Each thread opens a separate connection to the LDAP server.
20899 The default is to start 5 threads.
20901 Defaults to @samp{disabled}.
20905 @deftypevr {@code{nslcd-configuration} parameter} string uid
20906 This specifies the user id with which the daemon should be run.
20908 Defaults to @samp{"nslcd"}.
20912 @deftypevr {@code{nslcd-configuration} parameter} string gid
20913 This specifies the group id with which the daemon should be run.
20915 Defaults to @samp{"nslcd"}.
20919 @deftypevr {@code{nslcd-configuration} parameter} log-option log
20920 This option controls the way logging is done via a list containing
20921 SCHEME and LEVEL. The SCHEME argument may either be the symbols
20922 @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
20923 argument is optional and specifies the log level. The log level may be
20924 one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
20925 @samp{notice}, @samp{info} or @samp{debug}. All messages with the
20926 specified log level or higher are logged.
20928 Defaults to @samp{("/var/log/nslcd" info)}.
20932 @deftypevr {@code{nslcd-configuration} parameter} list uri
20933 The list of LDAP server URIs. Normally, only the first server will be
20934 used with the following servers as fall-back.
20936 Defaults to @samp{("ldap://localhost:389/")}.
20940 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
20941 The version of the LDAP protocol to use. The default is to use the
20942 maximum version supported by the LDAP library.
20944 Defaults to @samp{disabled}.
20948 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
20949 Specifies the distinguished name with which to bind to the directory
20950 server for lookups. The default is to bind anonymously.
20952 Defaults to @samp{disabled}.
20956 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
20957 Specifies the credentials with which to bind. This option is only
20958 applicable when used with binddn.
20960 Defaults to @samp{disabled}.
20964 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
20965 Specifies the distinguished name to use when the root user tries to
20966 modify a user's password using the PAM module.
20968 Defaults to @samp{disabled}.
20972 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
20973 Specifies the credentials with which to bind if the root user tries to
20974 change a user's password. This option is only applicable when used with
20977 Defaults to @samp{disabled}.
20981 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
20982 Specifies the SASL mechanism to be used when performing SASL
20985 Defaults to @samp{disabled}.
20989 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
20990 Specifies the SASL realm to be used when performing SASL authentication.
20992 Defaults to @samp{disabled}.
20996 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
20997 Specifies the authentication identity to be used when performing SASL
21000 Defaults to @samp{disabled}.
21004 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
21005 Specifies the authorization identity to be used when performing SASL
21008 Defaults to @samp{disabled}.
21012 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
21013 Determines whether the LDAP server host name should be canonicalised. If
21014 this is enabled the LDAP library will do a reverse host name lookup. By
21015 default, it is left up to the LDAP library whether this check is
21018 Defaults to @samp{disabled}.
21022 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
21023 Set the name for the GSS-API Kerberos credentials cache.
21025 Defaults to @samp{disabled}.
21029 @deftypevr {@code{nslcd-configuration} parameter} string base
21030 The directory search base.
21032 Defaults to @samp{"dc=example,dc=com"}.
21036 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
21037 Specifies the search scope (subtree, onelevel, base or children). The
21038 default scope is subtree; base scope is almost never useful for name
21039 service lookups; children scope is not supported on all servers.
21041 Defaults to @samp{(subtree)}.
21045 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
21046 Specifies the policy for dereferencing aliases. The default policy is
21047 to never dereference aliases.
21049 Defaults to @samp{disabled}.
21053 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
21054 Specifies whether automatic referral chasing should be enabled. The
21055 default behaviour is to chase referrals.
21057 Defaults to @samp{disabled}.
21061 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
21062 This option allows for custom attributes to be looked up instead of the
21063 default RFC 2307 attributes. It is a list of maps, each consisting of
21064 the name of a map, the RFC 2307 attribute to match and the query
21065 expression for the attribute as it is available in the directory.
21067 Defaults to @samp{()}.
21071 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
21072 A list of filters consisting of the name of a map to which the filter
21073 applies and an LDAP search filter expression.
21075 Defaults to @samp{()}.
21079 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
21080 Specifies the time limit in seconds to use when connecting to the
21081 directory server. The default value is 10 seconds.
21083 Defaults to @samp{disabled}.
21087 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
21088 Specifies the time limit (in seconds) to wait for a response from the
21089 LDAP server. A value of zero, which is the default, is to wait
21090 indefinitely for searches to be completed.
21092 Defaults to @samp{disabled}.
21096 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
21097 Specifies the period if inactivity (in seconds) after which the con‐
21098 nection to the LDAP server will be closed. The default is not to time
21101 Defaults to @samp{disabled}.
21105 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
21106 Specifies the number of seconds to sleep when connecting to all LDAP
21107 servers fails. By default one second is waited between the first
21108 failure and the first retry.
21110 Defaults to @samp{disabled}.
21114 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
21115 Specifies the time after which the LDAP server is considered to be
21116 permanently unavailable. Once this time is reached retries will be done
21117 only once per this time period. The default value is 10 seconds.
21119 Defaults to @samp{disabled}.
21123 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
21124 Specifies whether to use SSL/TLS or not (the default is not to). If
21125 'start-tls is specified then StartTLS is used rather than raw LDAP over
21128 Defaults to @samp{disabled}.
21132 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
21133 Specifies what checks to perform on a server-supplied certificate. The
21134 meaning of the values is described in the ldap.conf(5) manual page.
21136 Defaults to @samp{disabled}.
21140 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
21141 Specifies the directory containing X.509 certificates for peer authen‐
21142 tication. This parameter is ignored when using GnuTLS.
21144 Defaults to @samp{disabled}.
21148 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
21149 Specifies the path to the X.509 certificate for peer authentication.
21151 Defaults to @samp{disabled}.
21155 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
21156 Specifies the path to an entropy source. This parameter is ignored when
21159 Defaults to @samp{disabled}.
21163 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
21164 Specifies the ciphers to use for TLS as a string.
21166 Defaults to @samp{disabled}.
21170 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
21171 Specifies the path to the file containing the local certificate for
21172 client TLS authentication.
21174 Defaults to @samp{disabled}.
21178 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
21179 Specifies the path to the file containing the private key for client TLS
21182 Defaults to @samp{disabled}.
21186 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
21187 Set this to a number greater than 0 to request paged results from the
21188 LDAP server in accordance with RFC2696. The default (0) is to not
21189 request paged results.
21191 Defaults to @samp{disabled}.
21195 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
21196 This option prevents group membership lookups through LDAP for the
21197 specified users. Alternatively, the value 'all-local may be used. With
21198 that value nslcd builds a full list of non-LDAP users on startup.
21200 Defaults to @samp{disabled}.
21204 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
21205 This option ensures that LDAP users with a numeric user id lower than
21206 the specified value are ignored.
21208 Defaults to @samp{disabled}.
21212 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
21213 This option specifies an offset that is added to all LDAP numeric user
21214 ids. This can be used to avoid user id collisions with local users.
21216 Defaults to @samp{disabled}.
21220 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
21221 This option specifies an offset that is added to all LDAP numeric group
21222 ids. This can be used to avoid user id collisions with local groups.
21224 Defaults to @samp{disabled}.
21228 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
21229 If this option is set, the member attribute of a group may point to
21230 another group. Members of nested groups are also returned in the higher
21231 level group and parent groups are returned when finding groups for a
21232 specific user. The default is not to perform extra searches for nested
21235 Defaults to @samp{disabled}.
21239 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
21240 If this option is set, the group member list is not retrieved when
21241 looking up groups. Lookups for finding which groups a user belongs to
21242 will remain functional so the user will likely still get the correct
21243 groups assigned on login.
21245 Defaults to @samp{disabled}.
21249 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
21250 If this option is set, functions which cause all user/group entries to
21251 be loaded from the directory will not succeed in doing so. This can
21252 dramatically reduce LDAP server load in situations where there are a
21253 great number of users and/or groups. This option is not recommended for
21254 most configurations.
21256 Defaults to @samp{disabled}.
21260 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
21261 This option can be used to specify how user and group names are verified
21262 within the system. This pattern is used to check all user and group
21263 names that are requested and returned from LDAP.
21265 Defaults to @samp{disabled}.
21269 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
21270 This specifies whether or not to perform searches using case-insensitive
21271 matching. Enabling this could open up the system to authorization
21272 bypass vulnerabilities and introduce nscd cache poisoning
21273 vulnerabilities which allow denial of service.
21275 Defaults to @samp{disabled}.
21279 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
21280 This option specifies whether password policy controls are requested and
21281 handled from the LDAP server when performing user authentication.
21283 Defaults to @samp{disabled}.
21287 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
21288 By default nslcd performs an LDAP search with the user's credentials
21289 after BIND (authentication) to ensure that the BIND operation was
21290 successful. The default search is a simple check to see if the user's
21291 DN exists. A search filter can be specified that will be used instead.
21292 It should return at least one entry.
21294 Defaults to @samp{disabled}.
21298 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
21299 This option allows flexible fine tuning of the authorisation check that
21300 should be performed. The search filter specified is executed and if any
21301 entries match, access is granted, otherwise access is denied.
21303 Defaults to @samp{disabled}.
21307 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
21308 If this option is set password modification using pam_ldap will be
21309 denied and the specified message will be presented to the user instead.
21310 The message can be used to direct the user to an alternative means of
21311 changing their password.
21313 Defaults to @samp{disabled}.
21317 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
21318 List of pam service names for which LDAP authentication should suffice.
21320 Defaults to @samp{()}.
21324 @c %end of generated documentation for nslcd-configuration
21328 @subsection Web Services
21333 The @code{(gnu services web)} module provides the Apache HTTP Server,
21334 the nginx web server, and also a fastcgi wrapper daemon.
21336 @subsubheading Apache HTTP Server
21338 @deffn {Scheme Variable} httpd-service-type
21339 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
21340 (@dfn{httpd}). The value for this service type is a
21341 @code{httpd-configuration} record.
21343 A simple example configuration is given below.
21346 (service httpd-service-type
21347 (httpd-configuration
21350 (server-name "www.example.com")
21351 (document-root "/srv/http/www.example.com")))))
21354 Other services can also extend the @code{httpd-service-type} to add to
21358 (simple-service 'www.example.com-server httpd-service-type
21362 (list (string-join '("ServerName www.example.com"
21363 "DocumentRoot /srv/http/www.example.com")
21368 The details for the @code{httpd-configuration}, @code{httpd-module},
21369 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
21372 @deffn {Data Type} httpd-configuration
21373 This data type represents the configuration for the httpd service.
21376 @item @code{package} (default: @code{httpd})
21377 The httpd package to use.
21379 @item @code{pid-file} (default: @code{"/var/run/httpd"})
21380 The pid file used by the shepherd-service.
21382 @item @code{config} (default: @code{(httpd-config-file)})
21383 The configuration file to use with the httpd service. The default value
21384 is a @code{httpd-config-file} record, but this can also be a different
21385 G-expression that generates a file, for example a @code{plain-file}. A
21386 file outside of the store can also be specified through a string.
21391 @deffn {Data Type} httpd-module
21392 This data type represents a module for the httpd service.
21396 The name of the module.
21399 The file for the module. This can be relative to the httpd package being
21400 used, the absolute location of a file, or a G-expression for a file
21401 within the store, for example @code{(file-append mod-wsgi
21402 "/modules/mod_wsgi.so")}.
21407 @defvr {Scheme Variable} %default-httpd-modules
21408 A default list of @code{httpd-module} objects.
21411 @deffn {Data Type} httpd-config-file
21412 This data type represents a configuration file for the httpd service.
21415 @item @code{modules} (default: @code{%default-httpd-modules})
21416 The modules to load. Additional modules can be added here, or loaded by
21417 additional configuration.
21419 For example, in order to handle requests for PHP files, you can use Apache’s
21420 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
21423 (service httpd-service-type
21424 (httpd-configuration
21429 (name "proxy_module")
21430 (file "modules/mod_proxy.so"))
21432 (name "proxy_fcgi_module")
21433 (file "modules/mod_proxy_fcgi.so"))
21434 %default-httpd-modules))
21435 (extra-config (list "\
21436 <FilesMatch \\.php$>
21437 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
21438 </FilesMatch>"))))))
21439 (service php-fpm-service-type
21440 (php-fpm-configuration
21441 (socket "/var/run/php-fpm.sock")
21442 (socket-group "httpd")))
21445 @item @code{server-root} (default: @code{httpd})
21446 The @code{ServerRoot} in the configuration file, defaults to the httpd
21447 package. Directives including @code{Include} and @code{LoadModule} are
21448 taken as relative to the server root.
21450 @item @code{server-name} (default: @code{#f})
21451 The @code{ServerName} in the configuration file, used to specify the
21452 request scheme, hostname and port that the server uses to identify
21455 This doesn't need to be set in the server config, and can be specified
21456 in virtual hosts. The default is @code{#f} to not specify a
21459 @item @code{document-root} (default: @code{"/srv/http"})
21460 The @code{DocumentRoot} from which files will be served.
21462 @item @code{listen} (default: @code{'("80")})
21463 The list of values for the @code{Listen} directives in the config
21464 file. The value should be a list of strings, when each string can
21465 specify the port number to listen on, and optionally the IP address and
21468 @item @code{pid-file} (default: @code{"/var/run/httpd"})
21469 The @code{PidFile} to use. This should match the @code{pid-file} set in
21470 the @code{httpd-configuration} so that the Shepherd service is
21471 configured correctly.
21473 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
21474 The @code{ErrorLog} to which the server will log errors.
21476 @item @code{user} (default: @code{"httpd"})
21477 The @code{User} which the server will answer requests as.
21479 @item @code{group} (default: @code{"httpd"})
21480 The @code{Group} which the server will answer requests as.
21482 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
21483 A flat list of strings and G-expressions which will be added to the end
21484 of the configuration file.
21486 Any values which the service is extended with will be appended to this
21492 @deffn {Data Type} httpd-virtualhost
21493 This data type represents a virtualhost configuration block for the httpd service.
21495 These should be added to the extra-config for the httpd-service.
21498 (simple-service 'www.example.com-server httpd-service-type
21502 (list (string-join '("ServerName www.example.com"
21503 "DocumentRoot /srv/http/www.example.com")
21508 @item @code{addresses-and-ports}
21509 The addresses and ports for the @code{VirtualHost} directive.
21511 @item @code{contents}
21512 The contents of the @code{VirtualHost} directive, this should be a list
21513 of strings and G-expressions.
21518 @subsubheading NGINX
21520 @deffn {Scheme Variable} nginx-service-type
21521 Service type for the @uref{https://nginx.org/,NGinx} web server. The
21522 value for this service type is a @code{<nginx-configuration>} record.
21524 A simple example configuration is given below.
21527 (service nginx-service-type
21528 (nginx-configuration
21530 (list (nginx-server-configuration
21531 (server-name '("www.example.com"))
21532 (root "/srv/http/www.example.com"))))))
21535 In addition to adding server blocks to the service configuration
21536 directly, this service can be extended by other services to add server
21537 blocks, as in this example:
21540 (simple-service 'my-extra-server nginx-service-type
21541 (list (nginx-server-configuration
21542 (root "/srv/http/extra-website")
21543 (try-files (list "$uri" "$uri/index.html")))))
21547 At startup, @command{nginx} has not yet read its configuration file, so
21548 it uses a default file to log error messages. If it fails to load its
21549 configuration file, that is where error messages are logged. After the
21550 configuration file is loaded, the default error log file changes as per
21551 configuration. In our case, startup error messages can be found in
21552 @file{/var/run/nginx/logs/error.log}, and after configuration in
21553 @file{/var/log/nginx/error.log}. The second location can be changed
21554 with the @var{log-directory} configuration option.
21556 @deffn {Data Type} nginx-configuration
21557 This data type represents the configuration for NGinx. Some
21558 configuration can be done through this and the other provided record
21559 types, or alternatively, a config file can be provided.
21562 @item @code{nginx} (default: @code{nginx})
21563 The nginx package to use.
21565 @item @code{log-directory} (default: @code{"/var/log/nginx"})
21566 The directory to which NGinx will write log files.
21568 @item @code{run-directory} (default: @code{"/var/run/nginx"})
21569 The directory in which NGinx will create a pid file, and write temporary
21572 @item @code{server-blocks} (default: @code{'()})
21573 A list of @dfn{server blocks} to create in the generated configuration
21574 file, the elements should be of type
21575 @code{<nginx-server-configuration>}.
21577 The following example would setup NGinx to serve @code{www.example.com}
21578 from the @code{/srv/http/www.example.com} directory, without using
21581 (service nginx-service-type
21582 (nginx-configuration
21584 (list (nginx-server-configuration
21585 (server-name '("www.example.com"))
21586 (root "/srv/http/www.example.com"))))))
21589 @item @code{upstream-blocks} (default: @code{'()})
21590 A list of @dfn{upstream blocks} to create in the generated configuration
21591 file, the elements should be of type
21592 @code{<nginx-upstream-configuration>}.
21594 Configuring upstreams through the @code{upstream-blocks} can be useful
21595 when combined with @code{locations} in the
21596 @code{<nginx-server-configuration>} records. The following example
21597 creates a server configuration with one location configuration, that
21598 will proxy requests to a upstream configuration, which will handle
21599 requests with two servers.
21604 (nginx-configuration
21606 (list (nginx-server-configuration
21607 (server-name '("www.example.com"))
21608 (root "/srv/http/www.example.com")
21611 (nginx-location-configuration
21613 (body '("proxy_pass http://server-proxy;"))))))))
21615 (list (nginx-upstream-configuration
21616 (name "server-proxy")
21617 (servers (list "server1.example.com"
21618 "server2.example.com")))))))
21621 @item @code{file} (default: @code{#f})
21622 If a configuration @var{file} is provided, this will be used, rather than
21623 generating a configuration file from the provided @code{log-directory},
21624 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
21625 proper operation, these arguments should match what is in @var{file} to ensure
21626 that the directories are created when the service is activated.
21628 This can be useful if you have an existing configuration file, or it's
21629 not possible to do what is required through the other parts of the
21630 nginx-configuration record.
21632 @item @code{server-names-hash-bucket-size} (default: @code{#f})
21633 Bucket size for the server names hash tables, defaults to @code{#f} to
21634 use the size of the processors cache line.
21636 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
21637 Maximum bucket size for the server names hash tables.
21639 @item @code{modules} (default: @code{'()})
21640 List of nginx dynamic modules to load. This should be a list of file
21641 names of loadable modules, as in this example:
21646 (file-append nginx-accept-language-module "\
21647 /etc/nginx/modules/ngx_http_accept_language_module.so")))
21650 @item @code{global-directives} (default: @code{'((events . ()))})
21651 Association list of global directives for the top level of the nginx
21652 configuration. Values may themselves be association lists.
21656 `((worker_processes . 16)
21658 (events . ((worker_connections . 1024)))))
21661 @item @code{extra-content} (default: @code{""})
21662 Extra content for the @code{http} block. Should be string or a string
21663 valued G-expression.
21668 @deftp {Data Type} nginx-server-configuration
21669 Data type representing the configuration of an nginx server block.
21670 This type has the following parameters:
21673 @item @code{listen} (default: @code{'("80" "443 ssl")})
21674 Each @code{listen} directive sets the address and port for IP, or the
21675 path for a UNIX-domain socket on which the server will accept requests.
21676 Both address and port, or only address or only port can be specified.
21677 An address may also be a hostname, for example:
21680 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
21683 @item @code{server-name} (default: @code{(list 'default)})
21684 A list of server names this server represents. @code{'default} represents the
21685 default server for connections matching no other server.
21687 @item @code{root} (default: @code{"/srv/http"})
21688 Root of the website nginx will serve.
21690 @item @code{locations} (default: @code{'()})
21691 A list of @dfn{nginx-location-configuration} or
21692 @dfn{nginx-named-location-configuration} records to use within this
21695 @item @code{index} (default: @code{(list "index.html")})
21696 Index files to look for when clients ask for a directory. If it cannot be found,
21697 Nginx will send the list of files in the directory.
21699 @item @code{try-files} (default: @code{'()})
21700 A list of files whose existence is checked in the specified order.
21701 @code{nginx} will use the first file it finds to process the request.
21703 @item @code{ssl-certificate} (default: @code{#f})
21704 Where to find the certificate for secure connections. Set it to @code{#f} if
21705 you don't have a certificate or you don't want to use HTTPS.
21707 @item @code{ssl-certificate-key} (default: @code{#f})
21708 Where to find the private key for secure connections. Set it to @code{#f} if
21709 you don't have a key or you don't want to use HTTPS.
21711 @item @code{server-tokens?} (default: @code{#f})
21712 Whether the server should add its configuration to response.
21714 @item @code{raw-content} (default: @code{'()})
21715 A list of raw lines added to the server block.
21720 @deftp {Data Type} nginx-upstream-configuration
21721 Data type representing the configuration of an nginx @code{upstream}
21722 block. This type has the following parameters:
21726 Name for this group of servers.
21728 @item @code{servers}
21729 Specify the addresses of the servers in the group. The address can be
21730 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
21731 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
21732 prefix @samp{unix:}. For addresses using an IP address or domain name,
21733 the default port is 80, and a different port can be specified
21739 @deftp {Data Type} nginx-location-configuration
21740 Data type representing the configuration of an nginx @code{location}
21741 block. This type has the following parameters:
21745 URI which this location block matches.
21747 @anchor{nginx-location-configuration body}
21749 Body of the location block, specified as a list of strings. This can contain
21751 configuration directives. For example, to pass requests to a upstream
21752 server group defined using an @code{nginx-upstream-configuration} block,
21753 the following directive would be specified in the body @samp{(list "proxy_pass
21754 http://upstream-name;")}.
21759 @deftp {Data Type} nginx-named-location-configuration
21760 Data type representing the configuration of an nginx named location
21761 block. Named location blocks are used for request redirection, and not
21762 used for regular request processing. This type has the following
21767 Name to identify this location block.
21770 @xref{nginx-location-configuration body}, as the body for named location
21771 blocks can be used in a similar way to the
21772 @code{nginx-location-configuration body}. One restriction is that the
21773 body of a named location block cannot contain location blocks.
21778 @subsubheading Varnish Cache
21780 Varnish is a fast cache server that sits in between web applications
21781 and end users. It proxies requests from clients and caches the
21782 accessed URLs such that multiple requests for the same resource only
21783 creates one request to the back-end.
21785 @defvr {Scheme Variable} varnish-service-type
21786 Service type for the Varnish daemon.
21789 @deftp {Data Type} varnish-configuration
21790 Data type representing the @code{varnish} service configuration.
21791 This type has the following parameters:
21794 @item @code{package} (default: @code{varnish})
21795 The Varnish package to use.
21797 @item @code{name} (default: @code{"default"})
21798 A name for this Varnish instance. Varnish will create a directory in
21799 @file{/var/varnish/} with this name and keep temporary files there. If
21800 the name starts with a forward slash, it is interpreted as an absolute
21803 Pass the @code{-n} argument to other Varnish programs to connect to the
21804 named instance, e.g.@: @command{varnishncsa -n default}.
21806 @item @code{backend} (default: @code{"localhost:8080"})
21807 The backend to use. This option has no effect if @code{vcl} is set.
21809 @item @code{vcl} (default: #f)
21810 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
21811 is @code{#f}, Varnish will proxy @code{backend} using the default
21812 configuration. Otherwise this must be a file-like object with valid
21815 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
21816 For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
21817 can do something along these lines:
21820 (define %gnu-mirror
21821 (plain-file "gnu.vcl"
21823 backend gnu @{ .host = \"www.gnu.org\"; @}"))
21827 (services (cons (service varnish-service-type
21828 (varnish-configuration
21830 (vcl %gnu-mirror)))
21834 The configuration of an already running Varnish instance can be inspected
21835 and changed using the @command{varnishadm} program.
21837 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
21838 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
21839 comprehensive documentation on Varnish and its configuration language.
21841 @item @code{listen} (default: @code{'("localhost:80")})
21842 List of addresses Varnish will listen on.
21844 @item @code{storage} (default: @code{'("malloc,128m")})
21845 List of storage backends that will be available in VCL.
21847 @item @code{parameters} (default: @code{'()})
21848 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
21850 @item @code{extra-options} (default: @code{'()})
21851 Additional arguments to pass to the @command{varnishd} process.
21856 @subsubheading Patchwork
21858 Patchwork is a patch tracking system. It can collect patches sent to a
21859 mailing list, and display them in a web interface.
21861 @defvr {Scheme Variable} patchwork-service-type
21862 Service type for Patchwork.
21865 The following example is an example of a minimal service for Patchwork, for
21866 the @code{patchwork.example.com} domain.
21869 (service patchwork-service-type
21870 (patchwork-configuration
21871 (domain "patchwork.example.com")
21873 (patchwork-settings-module
21874 (allowed-hosts (list domain))
21875 (default-from-email "patchwork@@patchwork.example.com")))
21876 (getmail-retriever-config
21877 (getmail-retriever-configuration
21878 (type "SimpleIMAPSSLRetriever")
21879 (server "imap.example.com")
21881 (username "patchwork")
21883 (list (file-append coreutils "/bin/cat")
21884 "/etc/getmail-patchwork-imap-password"))
21886 '((mailboxes . ("Patches"))))))))
21890 There are three records for configuring the Patchwork service. The
21891 @code{<patchwork-configuration>} relates to the configuration for Patchwork
21892 within the HTTPD service.
21894 The @code{settings-module} field within the @code{<patchwork-configuration>}
21895 record can be populated with the @code{<patchwork-settings-module>} record,
21896 which describes a settings module that is generated within the Guix store.
21898 For the @code{database-configuration} field within the
21899 @code{<patchwork-settings-module>}, the
21900 @code{<patchwork-database-configuration>} must be used.
21902 @deftp {Data Type} patchwork-configuration
21903 Data type representing the Patchwork service configuration. This type has the
21904 following parameters:
21907 @item @code{patchwork} (default: @code{patchwork})
21908 The Patchwork package to use.
21910 @item @code{domain}
21911 The domain to use for Patchwork, this is used in the HTTPD service virtual
21914 @item @code{settings-module}
21915 The settings module to use for Patchwork. As a Django application, Patchwork
21916 is configured with a Python module containing the settings. This can either be
21917 an instance of the @code{<patchwork-settings-module>} record, any other record
21918 that represents the settings in the store, or a directory outside of the
21921 @item @code{static-path} (default: @code{"/static/"})
21922 The path under which the HTTPD service should serve the static files.
21924 @item @code{getmail-retriever-config}
21925 The getmail-retriever-configuration record value to use with
21926 Patchwork. Getmail will be configured with this value, the messages will be
21927 delivered to Patchwork.
21932 @deftp {Data Type} patchwork-settings-module
21933 Data type representing a settings module for Patchwork. Some of these
21934 settings relate directly to Patchwork, but others relate to Django, the web
21935 framework used by Patchwork, or the Django Rest Framework library. This type
21936 has the following parameters:
21939 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
21940 The database connection settings used for Patchwork. See the
21941 @code{<patchwork-database-configuration>} record type for more information.
21943 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
21944 Patchwork, as a Django web application uses a secret key for cryptographically
21945 signing values. This file should contain a unique unpredictable value.
21947 If this file does not exist, it will be created and populated with a random
21948 value by the patchwork-setup shepherd service.
21950 This setting relates to Django.
21952 @item @code{allowed-hosts}
21953 A list of valid hosts for this Patchwork service. This should at least include
21954 the domain specified in the @code{<patchwork-configuration>} record.
21956 This is a Django setting.
21958 @item @code{default-from-email}
21959 The email address from which Patchwork should send email by default.
21961 This is a Patchwork setting.
21963 @item @code{static-url} (default: @code{#f})
21964 The URL to use when serving static assets. It can be part of a URL, or a full
21965 URL, but must end in a @code{/}.
21967 If the default value is used, the @code{static-path} value from the
21968 @code{<patchwork-configuration>} record will be used.
21970 This is a Django setting.
21972 @item @code{admins} (default: @code{'()})
21973 Email addresses to send the details of errors that occur. Each value should
21974 be a list containing two elements, the name and then the email address.
21976 This is a Django setting.
21978 @item @code{debug?} (default: @code{#f})
21979 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
21980 messages will be shown.
21982 This is a Django setting.
21984 @item @code{enable-rest-api?} (default: @code{#t})
21985 Whether to enable the Patchwork REST API.
21987 This is a Patchwork setting.
21989 @item @code{enable-xmlrpc?} (default: @code{#t})
21990 Whether to enable the XML RPC API.
21992 This is a Patchwork setting.
21994 @item @code{force-https-links?} (default: @code{#t})
21995 Whether to use HTTPS links on Patchwork pages.
21997 This is a Patchwork setting.
21999 @item @code{extra-settings} (default: @code{""})
22000 Extra code to place at the end of the Patchwork settings module.
22005 @deftp {Data Type} patchwork-database-configuration
22006 Data type representing the database configuration for Patchwork.
22009 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
22010 The database engine to use.
22012 @item @code{name} (default: @code{"patchwork"})
22013 The name of the database to use.
22015 @item @code{user} (default: @code{"httpd"})
22016 The user to connect to the database as.
22018 @item @code{password} (default: @code{""})
22019 The password to use when connecting to the database.
22021 @item @code{host} (default: @code{""})
22022 The host to make the database connection to.
22024 @item @code{port} (default: @code{""})
22025 The port on which to connect to the database.
22030 @subsubheading Mumi
22032 @cindex Mumi, Debbugs Web interface
22033 @cindex Debbugs, Mumi Web interface
22034 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
22035 Web interface to the Debbugs bug tracker, by default for
22036 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
22037 but it also fetches and indexes mail retrieved from Debbugs.
22039 @defvr {Scheme Variable} mumi-service-type
22040 This is the service type for Mumi.
22043 @deftp {Data Type} mumi-configuration
22044 Data type representing the Mumi service configuration. This type has the
22048 @item @code{mumi} (default: @code{mumi})
22049 The Mumi package to use.
22051 @item @code{mailer?} (default: @code{#true})
22052 Whether to enable or disable the mailer component.
22054 @item @code{mumi-configuration-sender}
22055 The email address used as the sender for comments.
22057 @item @code{mumi-configuration-smtp}
22058 A URI to configure the SMTP settings for Mailutils. This could be
22059 something like @code{sendmail:///path/to/bin/msmtp} or any other URI
22060 supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
22061 mailutils, GNU@tie{}Mailutils}.
22067 @subsubheading FastCGI
22070 FastCGI is an interface between the front-end and the back-end of a web
22071 service. It is a somewhat legacy facility; new web services should
22072 generally just talk HTTP between the front-end and the back-end.
22073 However there are a number of back-end services such as PHP or the
22074 optimized HTTP Git repository access that use FastCGI, so we have
22075 support for it in Guix.
22077 To use FastCGI, you configure the front-end web server (e.g., nginx) to
22078 dispatch some subset of its requests to the fastcgi backend, which
22079 listens on a local TCP or UNIX socket. There is an intermediary
22080 @code{fcgiwrap} program that sits between the actual backend process and
22081 the web server. The front-end indicates which backend program to run,
22082 passing that information to the @code{fcgiwrap} process.
22084 @defvr {Scheme Variable} fcgiwrap-service-type
22085 A service type for the @code{fcgiwrap} FastCGI proxy.
22088 @deftp {Data Type} fcgiwrap-configuration
22089 Data type representing the configuration of the @code{fcgiwrap} service.
22090 This type has the following parameters:
22092 @item @code{package} (default: @code{fcgiwrap})
22093 The fcgiwrap package to use.
22095 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
22096 The socket on which the @code{fcgiwrap} process should listen, as a
22097 string. Valid @var{socket} values include
22098 @code{unix:@var{/path/to/unix/socket}},
22099 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
22100 @code{tcp6:[@var{ipv6_addr}]:port}.
22102 @item @code{user} (default: @code{fcgiwrap})
22103 @itemx @code{group} (default: @code{fcgiwrap})
22104 The user and group names, as strings, under which to run the
22105 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
22106 the user asks for the specific user or group names @code{fcgiwrap} that
22107 the corresponding user and/or group is present on the system.
22109 It is possible to configure a FastCGI-backed web service to pass HTTP
22110 authentication information from the front-end to the back-end, and to
22111 allow @code{fcgiwrap} to run the back-end process as a corresponding
22112 local user. To enable this capability on the back-end, run
22113 @code{fcgiwrap} as the @code{root} user and group. Note that this
22114 capability also has to be configured on the front-end as well.
22119 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
22120 with some additional features useful for sites of any size.
22122 These features include:
22124 @item Adaptive process spawning
22125 @item Basic statistics (similar to Apache's mod_status)
22126 @item Advanced process management with graceful stop/start
22127 @item Ability to start workers with different uid/gid/chroot/environment
22128 and different php.ini (replaces safe_mode)
22129 @item Stdout & stderr logging
22130 @item Emergency restart in case of accidental opcode cache destruction
22131 @item Accelerated upload support
22132 @item Support for a "slowlog"
22133 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
22134 a special function to finish request & flush all data while continuing to do
22135 something time-consuming (video converting, stats processing, etc.)
22137 ...@: and much more.
22139 @defvr {Scheme Variable} php-fpm-service-type
22140 A Service type for @code{php-fpm}.
22143 @deftp {Data Type} php-fpm-configuration
22144 Data Type for php-fpm service configuration.
22146 @item @code{php} (default: @code{php})
22147 The php package to use.
22148 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
22149 The address on which to accept FastCGI requests. Valid syntaxes are:
22151 @item @code{"ip.add.re.ss:port"}
22152 Listen on a TCP socket to a specific address on a specific port.
22153 @item @code{"port"}
22154 Listen on a TCP socket to all addresses on a specific port.
22155 @item @code{"/path/to/unix/socket"}
22156 Listen on a unix socket.
22159 @item @code{user} (default: @code{php-fpm})
22160 User who will own the php worker processes.
22161 @item @code{group} (default: @code{php-fpm})
22162 Group of the worker processes.
22163 @item @code{socket-user} (default: @code{php-fpm})
22164 User who can speak to the php-fpm socket.
22165 @item @code{socket-group} (default: @code{nginx})
22166 Group that can speak to the php-fpm socket.
22167 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
22168 The process id of the php-fpm process is written to this file
22169 once the service has started.
22170 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
22171 Log for the php-fpm master process.
22172 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
22173 Detailed settings for the php-fpm process manager.
22176 @item @code{<php-fpm-dynamic-process-manager-configuration>}
22177 @item @code{<php-fpm-static-process-manager-configuration>}
22178 @item @code{<php-fpm-on-demand-process-manager-configuration>}
22180 @item @code{display-errors} (default @code{#f})
22181 Determines whether php errors and warning should be sent to clients
22182 and displayed in their browsers.
22183 This is useful for local php development, but a security risk for public sites,
22184 as error messages can reveal passwords and personal data.
22185 @item @code{timezone} (default @code{#f})
22186 Specifies @code{php_admin_value[date.timezone]} parameter.
22187 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
22188 This file will log the @code{stderr} outputs of php worker processes.
22189 Can be set to @code{#f} to disable logging.
22190 @item @code{file} (default @code{#f})
22191 An optional override of the whole configuration.
22192 You can use the @code{mixed-text-file} function or an absolute filepath for it.
22196 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
22197 Data Type for the @code{dynamic} php-fpm process manager. With the
22198 @code{dynamic} process manager, spare worker processes are kept around
22199 based on it's configured limits.
22201 @item @code{max-children} (default: @code{5})
22202 Maximum of worker processes.
22203 @item @code{start-servers} (default: @code{2})
22204 How many worker processes should be started on start-up.
22205 @item @code{min-spare-servers} (default: @code{1})
22206 How many spare worker processes should be kept around at minimum.
22207 @item @code{max-spare-servers} (default: @code{3})
22208 How many spare worker processes should be kept around at maximum.
22212 @deftp {Data type} php-fpm-static-process-manager-configuration
22213 Data Type for the @code{static} php-fpm process manager. With the
22214 @code{static} process manager, an unchanging number of worker processes
22217 @item @code{max-children} (default: @code{5})
22218 Maximum of worker processes.
22222 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
22223 Data Type for the @code{on-demand} php-fpm process manager. With the
22224 @code{on-demand} process manager, worker processes are only created as
22227 @item @code{max-children} (default: @code{5})
22228 Maximum of worker processes.
22229 @item @code{process-idle-timeout} (default: @code{10})
22230 The time in seconds after which a process with no requests is killed.
22235 @deffn {Scheme Procedure} nginx-php-location @
22236 [#:nginx-package nginx] @
22237 [socket (string-append "/var/run/php" @
22238 (version-major (package-version php)) @
22240 A helper function to quickly add php to an @code{nginx-server-configuration}.
22243 A simple services setup for nginx with php can look like this:
22245 (services (cons* (service dhcp-client-service-type)
22246 (service php-fpm-service-type)
22247 (service nginx-service-type
22248 (nginx-server-configuration
22249 (server-name '("example.com"))
22250 (root "/srv/http/")
22252 (list (nginx-php-location)))
22254 (ssl-certificate #f)
22255 (ssl-certificate-key #f)))
22259 @cindex cat-avatar-generator
22260 The cat avatar generator is a simple service to demonstrate the use of php-fpm
22261 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
22262 the hash of a user's email address.
22264 @deffn {Scheme Procedure} cat-avatar-generator-service @
22265 [#:cache-dir "/var/cache/cat-avatar-generator"] @
22266 [#:package cat-avatar-generator] @
22267 [#:configuration (nginx-server-configuration)]
22268 Returns an nginx-server-configuration that inherits @code{configuration}. It
22269 extends the nginx configuration to add a server block that serves @code{package},
22270 a version of cat-avatar-generator. During execution, cat-avatar-generator will
22271 be able to use @code{cache-dir} as its cache directory.
22274 A simple setup for cat-avatar-generator can look like this:
22276 (services (cons* (cat-avatar-generator-service
22278 (nginx-server-configuration
22279 (server-name '("example.com"))))
22284 @subsubheading Hpcguix-web
22286 @cindex hpcguix-web
22287 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
22288 program is a customizable web interface to browse Guix packages,
22289 initially designed for users of high-performance computing (HPC)
22292 @defvr {Scheme Variable} hpcguix-web-service-type
22293 The service type for @code{hpcguix-web}.
22296 @deftp {Data Type} hpcguix-web-configuration
22297 Data type for the hpcguix-web service configuration.
22301 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
22302 configuration. The main items available in this spec are:
22305 @item @code{title-prefix} (default: @code{"hpcguix | "})
22306 The page title prefix.
22308 @item @code{guix-command} (default: @code{"guix"})
22309 The @command{guix} command.
22311 @item @code{package-filter-proc} (default: @code{(const #t)})
22312 A procedure specifying how to filter packages that are displayed.
22314 @item @code{package-page-extension-proc} (default: @code{(const '())})
22315 Extension package for @code{hpcguix-web}.
22317 @item @code{menu} (default: @code{'()})
22318 Additional entry in page @code{menu}.
22320 @item @code{channels} (default: @code{%default-channels})
22321 List of channels from which the package list is built (@pxref{Channels}).
22323 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
22324 The expiration time, in seconds, after which the package list is rebuilt from
22325 the latest instances of the given channels.
22328 See the hpcguix-web repository for a
22329 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
22332 @item @code{package} (default: @code{hpcguix-web})
22333 The hpcguix-web package to use.
22337 A typical hpcguix-web service declaration looks like this:
22340 (service hpcguix-web-service-type
22341 (hpcguix-web-configuration
22343 #~(define site-config
22344 (hpcweb-configuration
22345 (title-prefix "Guix-HPC - ")
22346 (menu '(("/about" "ABOUT"))))))))
22350 The hpcguix-web service periodically updates the package list it publishes by
22351 pulling channels from Git. To that end, it needs to access X.509 certificates
22352 so that it can authenticate Git servers when communicating over HTTPS, and it
22353 assumes that @file{/etc/ssl/certs} contains those certificates.
22355 Thus, make sure to add @code{nss-certs} or another certificate package to the
22356 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
22357 more information on X.509 certificates.
22360 @node Certificate Services
22361 @subsection Certificate Services
22364 @cindex HTTP, HTTPS
22365 @cindex Let's Encrypt
22366 @cindex TLS certificates
22367 The @code{(gnu services certbot)} module provides a service to
22368 automatically obtain a valid TLS certificate from the Let's Encrypt
22369 certificate authority. These certificates can then be used to serve
22370 content securely over HTTPS or other TLS-based protocols, with the
22371 knowledge that the client will be able to verify the server's
22374 @url{https://letsencrypt.org/, Let's Encrypt} provides the
22375 @code{certbot} tool to automate the certification process. This tool
22376 first securely generates a key on the server. It then makes a request
22377 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
22378 checks that the request originates from the host in question by using a
22379 challenge-response protocol, requiring the server to provide its
22380 response over HTTP. If that protocol completes successfully, the CA
22381 signs the key, resulting in a certificate. That certificate is valid
22382 for a limited period of time, and therefore to continue to provide TLS
22383 services, the server needs to periodically ask the CA to renew its
22386 The certbot service automates this process: the initial key
22387 generation, the initial certification request to the Let's Encrypt
22388 service, the web server challenge/response integration, writing the
22389 certificate to disk, the automated periodic renewals, and the deployment
22390 tasks associated with the renewal (e.g.@: reloading services, copying keys
22391 with different permissions).
22393 Certbot is run twice a day, at a random minute within the hour. It
22394 won't do anything until your certificates are due for renewal or
22395 revoked, but running it regularly would give your service a chance of
22396 staying online in case a Let's Encrypt-initiated revocation happened for
22399 By using this service, you agree to the ACME Subscriber Agreement, which
22400 can be found there:
22401 @url{https://acme-v01.api.letsencrypt.org/directory}.
22403 @defvr {Scheme Variable} certbot-service-type
22404 A service type for the @code{certbot} Let's Encrypt client. Its value
22405 must be a @code{certbot-configuration} record as in this example:
22408 (define %nginx-deploy-hook
22410 "nginx-deploy-hook"
22411 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
22412 (kill pid SIGHUP))))
22414 (service certbot-service-type
22415 (certbot-configuration
22416 (email "foo@@example.net")
22419 (certificate-configuration
22420 (domains '("example.net" "www.example.net"))
22421 (deploy-hook %nginx-deploy-hook))
22422 (certificate-configuration
22423 (domains '("bar.example.net")))))))
22426 See below for details about @code{certbot-configuration}.
22429 @deftp {Data Type} certbot-configuration
22430 Data type representing the configuration of the @code{certbot} service.
22431 This type has the following parameters:
22434 @item @code{package} (default: @code{certbot})
22435 The certbot package to use.
22437 @item @code{webroot} (default: @code{/var/www})
22438 The directory from which to serve the Let's Encrypt challenge/response
22441 @item @code{certificates} (default: @code{()})
22442 A list of @code{certificates-configuration}s for which to generate
22443 certificates and request signatures. Each certificate has a @code{name}
22444 and several @code{domains}.
22447 Mandatory email used for registration, recovery contact, and important
22448 account notifications.
22450 @item @code{server} (default: @code{#f})
22451 Optional URL of ACME server. Setting this overrides certbot's default,
22452 which is the Let's Encrypt server.
22454 @item @code{rsa-key-size} (default: @code{2048})
22455 Size of the RSA key.
22457 @item @code{default-location} (default: @i{see below})
22458 The default @code{nginx-location-configuration}. Because @code{certbot}
22459 needs to be able to serve challenges and responses, it needs to be able
22460 to run a web server. It does so by extending the @code{nginx} web
22461 service with an @code{nginx-server-configuration} listening on the
22462 @var{domains} on port 80, and which has a
22463 @code{nginx-location-configuration} for the @code{/.well-known/} URI
22464 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
22465 these nginx configuration data types.
22467 Requests to other URL paths will be matched by the
22468 @code{default-location}, which if present is added to all
22469 @code{nginx-server-configuration}s.
22471 By default, the @code{default-location} will issue a redirect from
22472 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
22473 you to define what to serve on your site via @code{https}.
22475 Pass @code{#f} to not issue a default location.
22479 @deftp {Data Type} certificate-configuration
22480 Data type representing the configuration of a certificate.
22481 This type has the following parameters:
22484 @item @code{name} (default: @i{see below})
22485 This name is used by Certbot for housekeeping and in file paths; it
22486 doesn't affect the content of the certificate itself. To see
22487 certificate names, run @code{certbot certificates}.
22489 Its default is the first provided domain.
22491 @item @code{domains} (default: @code{()})
22492 The first domain provided will be the subject CN of the certificate, and
22493 all domains will be Subject Alternative Names on the certificate.
22495 @item @code{challenge} (default: @code{#f})
22496 The challenge type that has to be run by certbot. If @code{#f} is specified,
22497 default to the HTTP challenge. If a value is specified, defaults to the
22498 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
22499 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
22500 and gives Let's Encrypt permission to log the public IP address of the
22501 requesting machine.
22503 @item @code{authentication-hook} (default: @code{#f})
22504 Command to be run in a shell once for each certificate challenge to be
22505 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
22506 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
22507 contains the validation string and @code{$CERTBOT_TOKEN} contains the
22508 file name of the resource requested when performing an HTTP-01 challenge.
22510 @item @code{cleanup-hook} (default: @code{#f})
22511 Command to be run in a shell once for each certificate challenge that
22512 have been answered by the @code{auth-hook}. For this command, the shell
22513 variables available in the @code{auth-hook} script are still available, and
22514 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
22515 of the @code{auth-hook} script.
22517 @item @code{deploy-hook} (default: @code{#f})
22518 Command to be run in a shell once for each successfully issued
22519 certificate. For this command, the shell variable
22520 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
22521 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
22522 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
22523 contain a space-delimited list of renewed certificate domains (for
22524 example, @samp{"example.com www.example.com"}.
22529 For each @code{certificate-configuration}, the certificate is saved to
22530 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
22531 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
22533 @subsection DNS Services
22534 @cindex DNS (domain name system)
22535 @cindex domain name system (DNS)
22537 The @code{(gnu services dns)} module provides services related to the
22538 @dfn{domain name system} (DNS). It provides a server service for hosting
22539 an @emph{authoritative} DNS server for multiple zones, slave or master.
22540 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
22541 caching and forwarding DNS server for the LAN, which uses
22542 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
22544 @subsubheading Knot Service
22546 An example configuration of an authoritative server for two zones, one master
22550 (define-zone-entries example.org.zone
22551 ;; Name TTL Class Type Data
22552 ("@@" "" "IN" "A" "127.0.0.1")
22553 ("@@" "" "IN" "NS" "ns")
22554 ("ns" "" "IN" "A" "127.0.0.1"))
22556 (define master-zone
22557 (knot-zone-configuration
22558 (domain "example.org")
22560 (origin "example.org")
22561 (entries example.org.zone)))))
22564 (knot-zone-configuration
22565 (domain "plop.org")
22566 (dnssec-policy "default")
22567 (master (list "plop-master"))))
22569 (define plop-master
22570 (knot-remote-configuration
22572 (address (list "208.76.58.171"))))
22576 (services (cons* (service knot-service-type
22577 (knot-configuration
22578 (remotes (list plop-master))
22579 (zones (list master-zone slave-zone))))
22584 @deffn {Scheme Variable} knot-service-type
22585 This is the type for the Knot DNS server.
22587 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
22588 zones, that is to say domain names you would buy from a registrar. This server
22589 is not a resolver, meaning that it can only resolve names for which it is
22590 authoritative. This server can be configured to serve zones as a master server
22591 or a slave server as a per-zone basis. Slave zones will get their data from
22592 masters, and will serve it as an authoritative server. From the point of view
22593 of a resolver, there is no difference between master and slave.
22595 The following data types are used to configure the Knot DNS server:
22598 @deftp {Data Type} knot-key-configuration
22599 Data type representing a key.
22600 This type has the following parameters:
22603 @item @code{id} (default: @code{""})
22604 An identifier for other configuration fields to refer to this key. IDs must
22605 be unique and must not be empty.
22607 @item @code{algorithm} (default: @code{#f})
22608 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
22609 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
22610 and @code{'hmac-sha512}.
22612 @item @code{secret} (default: @code{""})
22613 The secret key itself.
22618 @deftp {Data Type} knot-acl-configuration
22619 Data type representing an Access Control List (ACL) configuration.
22620 This type has the following parameters:
22623 @item @code{id} (default: @code{""})
22624 An identifier for ether configuration fields to refer to this key. IDs must be
22625 unique and must not be empty.
22627 @item @code{address} (default: @code{'()})
22628 An ordered list of IP addresses, network subnets, or network ranges represented
22629 with strings. The query must match one of them. Empty value means that
22630 address match is not required.
22632 @item @code{key} (default: @code{'()})
22633 An ordered list of references to keys represented with strings. The string
22634 must match a key ID defined in a @code{knot-key-configuration}. No key means
22635 that a key is not require to match that ACL.
22637 @item @code{action} (default: @code{'()})
22638 An ordered list of actions that are permitted or forbidden by this ACL. Possible
22639 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
22640 and @code{'update}.
22642 @item @code{deny?} (default: @code{#f})
22643 When true, the ACL defines restrictions. Listed actions are forbidden. When
22644 false, listed actions are allowed.
22649 @deftp {Data Type} zone-entry
22650 Data type representing a record entry in a zone file.
22651 This type has the following parameters:
22654 @item @code{name} (default: @code{"@@"})
22655 The name of the record. @code{"@@"} refers to the origin of the zone. Names
22656 are relative to the origin of the zone. For example, in the @code{example.org}
22657 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
22658 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
22659 refers to @code{ns.example.org}.
22661 @item @code{ttl} (default: @code{""})
22662 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
22664 @item @code{class} (default: @code{"IN"})
22665 The class of the record. Knot currently supports only @code{"IN"} and
22666 partially @code{"CH"}.
22668 @item @code{type} (default: @code{"A"})
22669 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
22670 address), NS (Name Server) and MX (Mail eXchange). Many other types are
22673 @item @code{data} (default: @code{""})
22674 The data contained in the record. For instance an IP address associated with
22675 an A record, or a domain name associated with an NS record. Remember that
22676 domain names are relative to the origin unless they end with a dot.
22681 @deftp {Data Type} zone-file
22682 Data type representing the content of a zone file.
22683 This type has the following parameters:
22686 @item @code{entries} (default: @code{'()})
22687 The list of entries. The SOA record is taken care of, so you don't need to
22688 put it in the list of entries. This list should probably contain an entry
22689 for your primary authoritative DNS server. Other than using a list of entries
22690 directly, you can use @code{define-zone-entries} to define a object containing
22691 the list of entries more easily, that you can later pass to the @code{entries}
22692 field of the @code{zone-file}.
22694 @item @code{origin} (default: @code{""})
22695 The name of your zone. This parameter cannot be empty.
22697 @item @code{ns} (default: @code{"ns"})
22698 The domain of your primary authoritative DNS server. The name is relative to
22699 the origin, unless it ends with a dot. It is mandatory that this primary
22700 DNS server corresponds to an NS record in the zone and that it is associated
22701 to an IP address in the list of entries.
22703 @item @code{mail} (default: @code{"hostmaster"})
22704 An email address people can contact you at, as the owner of the zone. This
22705 is translated as @code{<mail>@@<origin>}.
22707 @item @code{serial} (default: @code{1})
22708 The serial number of the zone. As this is used to keep track of changes by
22709 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
22710 Always increment it when you make a change in your zone.
22712 @item @code{refresh} (default: @code{(* 2 24 3600)})
22713 The frequency at which slaves will do a zone transfer. This value is a number
22714 of seconds. It can be computed by multiplications or with
22715 @code{(string->duration)}.
22717 @item @code{retry} (default: @code{(* 15 60)})
22718 The period after which a slave will retry to contact its master when it fails
22719 to do so a first time.
22721 @item @code{expiry} (default: @code{(* 14 24 3600)})
22722 Default TTL of records. Existing records are considered correct for at most
22723 this amount of time. After this period, resolvers will invalidate their cache
22724 and check again that it still exists.
22726 @item @code{nx} (default: @code{3600})
22727 Default TTL of inexistant records. This delay is usually short because you want
22728 your new domains to reach everyone quickly.
22733 @deftp {Data Type} knot-remote-configuration
22734 Data type representing a remote configuration.
22735 This type has the following parameters:
22738 @item @code{id} (default: @code{""})
22739 An identifier for other configuration fields to refer to this remote. IDs must
22740 be unique and must not be empty.
22742 @item @code{address} (default: @code{'()})
22743 An ordered list of destination IP addresses. Addresses are tried in sequence.
22744 An optional port can be given with the @@ separator. For instance:
22745 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
22747 @item @code{via} (default: @code{'()})
22748 An ordered list of source IP addresses. An empty list will have Knot choose
22749 an appropriate source IP. An optional port can be given with the @@ separator.
22750 The default is to choose at random.
22752 @item @code{key} (default: @code{#f})
22753 A reference to a key, that is a string containing the identifier of a key
22754 defined in a @code{knot-key-configuration} field.
22759 @deftp {Data Type} knot-keystore-configuration
22760 Data type representing a keystore to hold dnssec keys.
22761 This type has the following parameters:
22764 @item @code{id} (default: @code{""})
22765 The id of the keystore. It must not be empty.
22767 @item @code{backend} (default: @code{'pem})
22768 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
22770 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
22771 The configuration string of the backend. An example for the PKCS#11 is:
22772 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
22773 For the pem backend, the string represents a path in the file system.
22778 @deftp {Data Type} knot-policy-configuration
22779 Data type representing a dnssec policy. Knot DNS is able to automatically
22780 sign your zones. It can either generate and manage your keys automatically or
22781 use keys that you generate.
22783 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
22784 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
22785 zone. In order to be trusted, the KSK needs to be present in the parent zone
22786 (usually a top-level domain). If your registrar supports dnssec, you will
22787 have to send them your KSK's hash so they can add a DS record in their zone.
22788 This is not automated and need to be done each time you change your KSK.
22790 The policy also defines the lifetime of keys. Usually, ZSK can be changed
22791 easily and use weaker cryptographic functions (they use lower parameters) in
22792 order to sign records quickly, so they are changed often. The KSK however
22793 requires manual interaction with the registrar, so they are changed less often
22794 and use stronger parameters because they sign only one record.
22796 This type has the following parameters:
22799 @item @code{id} (default: @code{""})
22800 The id of the policy. It must not be empty.
22802 @item @code{keystore} (default: @code{"default"})
22803 A reference to a keystore, that is a string containing the identifier of a
22804 keystore defined in a @code{knot-keystore-configuration} field. The
22805 @code{"default"} identifier means the default keystore (a kasp database that
22806 was setup by this service).
22808 @item @code{manual?} (default: @code{#f})
22809 Whether the key management is manual or automatic.
22811 @item @code{single-type-signing?} (default: @code{#f})
22812 When @code{#t}, use the Single-Type Signing Scheme.
22814 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
22815 An algorithm of signing keys and issued signatures.
22817 @item @code{ksk-size} (default: @code{256})
22818 The length of the KSK. Note that this value is correct for the default
22819 algorithm, but would be unsecure for other algorithms.
22821 @item @code{zsk-size} (default: @code{256})
22822 The length of the ZSK. Note that this value is correct for the default
22823 algorithm, but would be unsecure for other algorithms.
22825 @item @code{dnskey-ttl} (default: @code{'default})
22826 The TTL value for DNSKEY records added into zone apex. The special
22827 @code{'default} value means same as the zone SOA TTL.
22829 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
22830 The period between ZSK publication and the next rollover initiation.
22832 @item @code{propagation-delay} (default: @code{(* 24 3600)})
22833 An extra delay added for each key rollover step. This value should be high
22834 enough to cover propagation of data from the master server to all slaves.
22836 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
22837 A validity period of newly issued signatures.
22839 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
22840 A period how long before a signature expiration the signature will be refreshed.
22842 @item @code{nsec3?} (default: @code{#f})
22843 When @code{#t}, NSEC3 will be used instead of NSEC.
22845 @item @code{nsec3-iterations} (default: @code{5})
22846 The number of additional times the hashing is performed.
22848 @item @code{nsec3-salt-length} (default: @code{8})
22849 The length of a salt field in octets, which is appended to the original owner
22850 name before hashing.
22852 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
22853 The validity period of newly issued salt field.
22858 @deftp {Data Type} knot-zone-configuration
22859 Data type representing a zone served by Knot.
22860 This type has the following parameters:
22863 @item @code{domain} (default: @code{""})
22864 The domain served by this configuration. It must not be empty.
22866 @item @code{file} (default: @code{""})
22867 The file where this zone is saved. This parameter is ignored by master zones.
22868 Empty means default location that depends on the domain name.
22870 @item @code{zone} (default: @code{(zone-file)})
22871 The content of the zone file. This parameter is ignored by slave zones. It
22872 must contain a zone-file record.
22874 @item @code{master} (default: @code{'()})
22875 A list of master remotes. When empty, this zone is a master. When set, this
22876 zone is a slave. This is a list of remotes identifiers.
22878 @item @code{ddns-master} (default: @code{#f})
22879 The main master. When empty, it defaults to the first master in the list of
22882 @item @code{notify} (default: @code{'()})
22883 A list of slave remote identifiers.
22885 @item @code{acl} (default: @code{'()})
22886 A list of acl identifiers.
22888 @item @code{semantic-checks?} (default: @code{#f})
22889 When set, this adds more semantic checks to the zone.
22891 @item @code{disable-any?} (default: @code{#f})
22892 When set, this forbids queries of the ANY type.
22894 @item @code{zonefile-sync} (default: @code{0})
22895 The delay between a modification in memory and on disk. 0 means immediate
22898 @item @code{zonefile-load} (default: @code{#f})
22899 The way the zone file contents are applied during zone load. Possible values
22903 @item @code{#f} for using the default value from Knot,
22904 @item @code{'none} for not using the zone file at all,
22905 @item @code{'difference} for computing the difference between already available
22906 contents and zone contents and applying it to the current zone contents,
22907 @item @code{'difference-no-serial} for the same as @code{'difference}, but
22908 ignoring the SOA serial in the zone file, while the server takes care of it
22910 @item @code{'whole} for loading zone contents from the zone file.
22913 @item @code{journal-content} (default: @code{#f})
22914 The way the journal is used to store zone and its changes. Possible values
22915 are @code{'none} to not use it at all, @code{'changes} to store changes and
22916 @code{'all} to store contents. @code{#f} does not set this option, so the
22917 default value from Knot is used.
22919 @item @code{max-journal-usage} (default: @code{#f})
22920 The maximum size for the journal on disk. @code{#f} does not set this option,
22921 so the default value from Knot is used.
22923 @item @code{max-journal-depth} (default: @code{#f})
22924 The maximum size of the history. @code{#f} does not set this option, so the
22925 default value from Knot is used.
22927 @item @code{max-zone-size} (default: @code{#f})
22928 The maximum size of the zone file. This limit is enforced for incoming
22929 transfer and updates. @code{#f} does not set this option, so the default
22930 value from Knot is used.
22932 @item @code{dnssec-policy} (default: @code{#f})
22933 A reference to a @code{knot-policy-configuration} record, or the special
22934 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
22937 @item @code{serial-policy} (default: @code{'increment})
22938 A policy between @code{'increment} and @code{'unixtime}.
22943 @deftp {Data Type} knot-configuration
22944 Data type representing the Knot configuration.
22945 This type has the following parameters:
22948 @item @code{knot} (default: @code{knot})
22951 @item @code{run-directory} (default: @code{"/var/run/knot"})
22952 The run directory. This directory will be used for pid file and sockets.
22954 @item @code{includes} (default: @code{'()})
22955 A list of strings or file-like objects denoting other files that must be
22956 included at the top of the configuration file.
22958 @cindex secrets, Knot service
22959 This can be used to manage secrets out-of-band. For example, secret
22960 keys may be stored in an out-of-band file not managed by Guix, and
22961 thus not visible in @file{/gnu/store}---e.g., you could store secret
22962 key configuration in @file{/etc/knot/secrets.conf} and add this file
22963 to the @code{includes} list.
22965 One can generate a secret tsig key (for nsupdate and zone transfers with the
22966 keymgr command from the knot package. Note that the package is not automatically
22967 installed by the service. The following example shows how to generate a new
22971 keymgr -t mysecret > /etc/knot/secrets.conf
22972 chmod 600 /etc/knot/secrets.conf
22975 Also note that the generated key will be named @var{mysecret}, so it is the
22976 name that needs to be used in the @var{key} field of the
22977 @code{knot-acl-configuration} record and in other places that need to refer
22980 It can also be used to add configuration not supported by this interface.
22982 @item @code{listen-v4} (default: @code{"0.0.0.0"})
22983 An ip address on which to listen.
22985 @item @code{listen-v6} (default: @code{"::"})
22986 An ip address on which to listen.
22988 @item @code{listen-port} (default: @code{53})
22989 A port on which to listen.
22991 @item @code{keys} (default: @code{'()})
22992 The list of knot-key-configuration used by this configuration.
22994 @item @code{acls} (default: @code{'()})
22995 The list of knot-acl-configuration used by this configuration.
22997 @item @code{remotes} (default: @code{'()})
22998 The list of knot-remote-configuration used by this configuration.
23000 @item @code{zones} (default: @code{'()})
23001 The list of knot-zone-configuration used by this configuration.
23006 @subsubheading Knot Resolver Service
23008 @deffn {Scheme Variable} knot-resolver-service-type
23009 This this the type of the knot resolver service, whose value should be
23010 an @code{knot-resolver-configuration} object as in this example:
23013 (service knot-resolver-service-type
23014 (knot-resolver-configuration
23015 (kresd-config-file (plain-file "kresd.conf" "
23016 net.listen('192.168.0.1', 5353)
23017 user('knot-resolver', 'knot-resolver')
23018 modules = @{ 'hints > iterate', 'stats', 'predict' @}
23019 cache.size = 100 * MB
23023 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
23026 @deftp {Data Type} knot-resolver-configuration
23027 Data type representing the configuration of knot-resolver.
23030 @item @code{package} (default: @var{knot-resolver})
23031 Package object of the knot DNS resolver.
23033 @item @code{kresd-config-file} (default: %kresd.conf)
23034 File-like object of the kresd configuration file to use, by default it
23035 will listen on @code{127.0.0.1} and @code{::1}.
23037 @item @code{garbage-collection-interval} (default: 1000)
23038 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
23044 @subsubheading Dnsmasq Service
23046 @deffn {Scheme Variable} dnsmasq-service-type
23047 This is the type of the dnsmasq service, whose value should be an
23048 @code{dnsmasq-configuration} object as in this example:
23051 (service dnsmasq-service-type
23052 (dnsmasq-configuration
23054 (servers '("192.168.1.1"))))
23058 @deftp {Data Type} dnsmasq-configuration
23059 Data type representing the configuration of dnsmasq.
23062 @item @code{package} (default: @var{dnsmasq})
23063 Package object of the dnsmasq server.
23065 @item @code{no-hosts?} (default: @code{#f})
23066 When true, don't read the hostnames in /etc/hosts.
23068 @item @code{port} (default: @code{53})
23069 The port to listen on. Setting this to zero completely disables DNS
23070 responses, leaving only DHCP and/or TFTP functions.
23072 @item @code{local-service?} (default: @code{#t})
23073 Accept DNS queries only from hosts whose address is on a local subnet,
23074 ie a subnet for which an interface exists on the server.
23076 @item @code{listen-addresses} (default: @code{'()})
23077 Listen on the given IP addresses.
23079 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
23080 The file to read the IP address of the upstream nameservers from.
23082 @item @code{no-resolv?} (default: @code{#f})
23083 When true, don't read @var{resolv-file}.
23085 @item @code{servers} (default: @code{'()})
23086 Specify IP address of upstream servers directly.
23088 @item @code{addresses} (default: @code{'()})
23089 For each entry, specify an IP address to return for any host in the
23090 given domains. Queries in the domains are never forwarded and always
23091 replied to with the specified IP address.
23093 This is useful for redirecting hosts locally, for example:
23096 (service dnsmasq-service-type
23097 (dnsmasq-configuration
23099 '(; Redirect to a local web-server.
23100 "/example.org/127.0.0.1"
23101 ; Redirect subdomain to a specific IP.
23102 "/subdomain.example.org/192.168.1.42"))))
23105 Note that rules in @file{/etc/hosts} take precedence over this.
23107 @item @code{cache-size} (default: @code{150})
23108 Set the size of dnsmasq's cache. Setting the cache size to zero
23111 @item @code{negative-cache?} (default: @code{#t})
23112 When false, disable negative caching.
23117 @subsubheading ddclient Service
23120 The ddclient service described below runs the ddclient daemon, which takes
23121 care of automatically updating DNS entries for service providers such as
23122 @uref{https://dyn.com/dns/, Dyn}.
23124 The following example show instantiates the service with its default
23128 (service ddclient-service-type)
23131 Note that ddclient needs to access credentials that are stored in a
23132 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
23133 @code{secret-file} below). You are expected to create this file manually, in
23134 an ``out-of-band'' fashion (you @emph{could} make this file part of the
23135 service configuration, for instance by using @code{plain-file}, but it will be
23136 world-readable @i{via} @file{/gnu/store}). See the examples in the
23137 @file{share/ddclient} directory of the @code{ddclient} package.
23139 @c %start of fragment
23141 Available @code{ddclient-configuration} fields are:
23143 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
23144 The ddclient package.
23148 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
23149 The period after which ddclient will retry to check IP and domain name.
23151 Defaults to @samp{300}.
23155 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
23156 Use syslog for the output.
23158 Defaults to @samp{#t}.
23162 @deftypevr {@code{ddclient-configuration} parameter} string mail
23165 Defaults to @samp{"root"}.
23169 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
23170 Mail failed update to user.
23172 Defaults to @samp{"root"}.
23176 @deftypevr {@code{ddclient-configuration} parameter} string pid
23177 The ddclient PID file.
23179 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
23183 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
23184 Enable SSL support.
23186 Defaults to @samp{#t}.
23190 @deftypevr {@code{ddclient-configuration} parameter} string user
23191 Specifies the user name or ID that is used when running ddclient
23194 Defaults to @samp{"ddclient"}.
23198 @deftypevr {@code{ddclient-configuration} parameter} string group
23199 Group of the user who will run the ddclient program.
23201 Defaults to @samp{"ddclient"}.
23205 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
23206 Secret file which will be appended to @file{ddclient.conf} file. This
23207 file contains credentials for use by ddclient. You are expected to
23208 create it manually.
23210 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
23214 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
23215 Extra options will be appended to @file{ddclient.conf} file.
23217 Defaults to @samp{()}.
23222 @c %end of fragment
23226 @subsection VPN Services
23227 @cindex VPN (virtual private network)
23228 @cindex virtual private network (VPN)
23230 The @code{(gnu services vpn)} module provides services related to
23231 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
23232 your machine to connect to a VPN, and a @emph{server} service for your machine
23233 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
23235 @deffn {Scheme Procedure} openvpn-client-service @
23236 [#:config (openvpn-client-configuration)]
23238 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
23241 @deffn {Scheme Procedure} openvpn-server-service @
23242 [#:config (openvpn-server-configuration)]
23244 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
23246 Both can be run simultaneously.
23249 @c %automatically generated documentation
23251 Available @code{openvpn-client-configuration} fields are:
23253 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
23254 The OpenVPN package.
23258 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
23259 The OpenVPN pid file.
23261 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
23265 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
23266 The protocol (UDP or TCP) used to open a channel between clients and
23269 Defaults to @samp{udp}.
23273 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
23274 The device type used to represent the VPN connection.
23276 Defaults to @samp{tun}.
23280 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
23281 The certificate authority to check connections against.
23283 Defaults to @samp{"/etc/openvpn/ca.crt"}.
23287 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
23288 The certificate of the machine the daemon is running on. It should be
23289 signed by the authority given in @code{ca}.
23291 Defaults to @samp{"/etc/openvpn/client.crt"}.
23295 @deftypevr {@code{openvpn-client-configuration} parameter} string key
23296 The key of the machine the daemon is running on. It must be the key whose
23297 certificate is @code{cert}.
23299 Defaults to @samp{"/etc/openvpn/client.key"}.
23303 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
23304 Whether to use the lzo compression algorithm.
23306 Defaults to @samp{#t}.
23310 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
23311 Don't re-read key files across SIGUSR1 or --ping-restart.
23313 Defaults to @samp{#t}.
23317 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
23318 Don't close and reopen TUN/TAP device or run up/down scripts across
23319 SIGUSR1 or --ping-restart restarts.
23321 Defaults to @samp{#t}.
23325 @deftypevr {@code{openvpn-client-configuration} parameter} boolean fast-io?
23326 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
23327 poll/epoll/select prior to the write operation.
23329 Defaults to @samp{#f}.
23332 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
23335 Defaults to @samp{3}.
23339 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
23340 Add an additional layer of HMAC authentication on top of the TLS control
23341 channel to protect against DoS attacks.
23343 Defaults to @samp{#f}.
23347 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string auth-user-pass
23348 Authenticate with server using username/password. The option is a file
23349 containing username/password on 2 lines. Do not use a file-like object as it
23350 would be added to the store and readable by any user.
23352 Defaults to @samp{'disabled}.
23355 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
23356 Whether to check the server certificate has server usage extension.
23358 Defaults to @samp{#t}.
23362 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
23363 Bind to a specific local port number.
23365 Defaults to @samp{#f}.
23369 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
23370 Retry resolving server address.
23372 Defaults to @samp{#t}.
23376 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
23377 A list of remote servers to connect to.
23379 Defaults to @samp{()}.
23381 Available @code{openvpn-remote-configuration} fields are:
23383 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
23386 Defaults to @samp{"my-server"}.
23390 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
23391 Port number the server listens to.
23393 Defaults to @samp{1194}.
23398 @c %end of automatic openvpn-client documentation
23400 @c %automatically generated documentation
23402 Available @code{openvpn-server-configuration} fields are:
23404 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
23405 The OpenVPN package.
23409 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
23410 The OpenVPN pid file.
23412 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
23416 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
23417 The protocol (UDP or TCP) used to open a channel between clients and
23420 Defaults to @samp{udp}.
23424 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
23425 The device type used to represent the VPN connection.
23427 Defaults to @samp{tun}.
23431 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
23432 The certificate authority to check connections against.
23434 Defaults to @samp{"/etc/openvpn/ca.crt"}.
23438 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
23439 The certificate of the machine the daemon is running on. It should be
23440 signed by the authority given in @code{ca}.
23442 Defaults to @samp{"/etc/openvpn/client.crt"}.
23446 @deftypevr {@code{openvpn-server-configuration} parameter} string key
23447 The key of the machine the daemon is running on. It must be the key whose
23448 certificate is @code{cert}.
23450 Defaults to @samp{"/etc/openvpn/client.key"}.
23454 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
23455 Whether to use the lzo compression algorithm.
23457 Defaults to @samp{#t}.
23461 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
23462 Don't re-read key files across SIGUSR1 or --ping-restart.
23464 Defaults to @samp{#t}.
23468 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
23469 Don't close and reopen TUN/TAP device or run up/down scripts across
23470 SIGUSR1 or --ping-restart restarts.
23472 Defaults to @samp{#t}.
23476 @deftypevr {@code{openvpn-server-configuration} parameter} boolean fast-io?
23477 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
23478 poll/epoll/select prior to the write operation.
23480 Defaults to @samp{#f}.
23483 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
23486 Defaults to @samp{3}.
23490 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
23491 Add an additional layer of HMAC authentication on top of the TLS control
23492 channel to protect against DoS attacks.
23494 Defaults to @samp{#f}.
23498 @deftypevr {@code{openvpn-server-configuration} parameter} number port
23499 Specifies the port number on which the server listens.
23501 Defaults to @samp{1194}.
23505 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
23506 An ip and mask specifying the subnet inside the virtual network.
23508 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
23512 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
23513 A CIDR notation specifying the IPv6 subnet inside the virtual network.
23515 Defaults to @samp{#f}.
23519 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
23520 The Diffie-Hellman parameters file.
23522 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
23526 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
23527 The file that records client IPs.
23529 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
23533 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
23534 When true, the server will act as a gateway for its clients.
23536 Defaults to @samp{#f}.
23540 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
23541 When true, clients are allowed to talk to each other inside the VPN.
23543 Defaults to @samp{#f}.
23547 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
23548 Causes ping-like messages to be sent back and forth over the link so
23549 that each side knows when the other side has gone down. @code{keepalive}
23550 requires a pair. The first element is the period of the ping sending,
23551 and the second element is the timeout before considering the other side
23556 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
23557 The maximum number of clients.
23559 Defaults to @samp{100}.
23563 @deftypevr {@code{openvpn-server-configuration} parameter} string status
23564 The status file. This file shows a small report on current connection.
23565 It is truncated and rewritten every minute.
23567 Defaults to @samp{"/var/run/openvpn/status"}.
23571 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
23572 The list of configuration for some clients.
23574 Defaults to @samp{()}.
23576 Available @code{openvpn-ccd-configuration} fields are:
23578 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
23581 Defaults to @samp{"client"}.
23585 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
23588 Defaults to @samp{#f}.
23592 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
23595 Defaults to @samp{#f}.
23602 @c %end of automatic openvpn-server documentation
23605 @node Network File System
23606 @subsection Network File System
23609 The @code{(gnu services nfs)} module provides the following services,
23610 which are most commonly used in relation to mounting or exporting
23611 directory trees as @dfn{network file systems} (NFS).
23613 While it is possible to use the individual components that together make
23614 up a Network File System service, we recommended to configure an NFS
23615 server with the @code{nfs-service-type}.
23617 @subsubheading NFS Service
23618 @cindex NFS, server
23620 The NFS service takes care of setting up all NFS component services,
23621 kernel configuration file systems, and installs configuration files in
23622 the locations that NFS expects.
23624 @defvr {Scheme Variable} nfs-service-type
23625 A service type for a complete NFS server.
23628 @deftp {Data Type} nfs-configuration
23629 This data type represents the configuration of the NFS service and all
23632 It has the following parameters:
23634 @item @code{nfs-utils} (default: @code{nfs-utils})
23635 The nfs-utils package to use.
23637 @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
23638 If a list of string values is provided, the @command{rpc.nfsd} daemon
23639 will be limited to supporting the given versions of the NFS protocol.
23641 @item @code{exports} (default: @code{'()})
23642 This is a list of directories the NFS server should export. Each entry
23643 is a list consisting of two elements: a directory name and a string
23644 containing all options. This is an example in which the directory
23645 @file{/export} is served to all NFS clients as a read-only share:
23651 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
23654 @item @code{rpcmountd-port} (default: @code{#f})
23655 The network port that the @command{rpc.mountd} daemon should use.
23657 @item @code{rpcstatd-port} (default: @code{#f})
23658 The network port that the @command{rpc.statd} daemon should use.
23660 @item @code{rpcbind} (default: @code{rpcbind})
23661 The rpcbind package to use.
23663 @item @code{idmap-domain} (default: @code{"localdomain"})
23664 The local NFSv4 domain name.
23666 @item @code{nfsd-port} (default: @code{2049})
23667 The network port that the @command{nfsd} daemon should use.
23669 @item @code{nfsd-threads} (default: @code{8})
23670 The number of threads used by the @command{nfsd} daemon.
23672 @item @code{nfsd-tcp?} (default: @code{#t})
23673 Whether the @command{nfsd} daemon should listen on a TCP socket.
23675 @item @code{nfsd-udp?} (default: @code{#f})
23676 Whether the @command{nfsd} daemon should listen on a UDP socket.
23678 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23679 The directory where the pipefs file system is mounted.
23681 @item @code{debug} (default: @code{'()"})
23682 A list of subsystems for which debugging output should be enabled. This
23683 is a list of symbols. Any of these symbols are valid: @code{nfsd},
23684 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
23688 If you don't need a complete NFS service or prefer to build it yourself
23689 you can use the individual component services that are documented below.
23691 @subsubheading RPC Bind Service
23694 The RPC Bind service provides a facility to map program numbers into
23695 universal addresses.
23696 Many NFS related services use this facility. Hence it is automatically
23697 started when a dependent service starts.
23699 @defvr {Scheme Variable} rpcbind-service-type
23700 A service type for the RPC portmapper daemon.
23704 @deftp {Data Type} rpcbind-configuration
23705 Data type representing the configuration of the RPC Bind Service.
23706 This type has the following parameters:
23708 @item @code{rpcbind} (default: @code{rpcbind})
23709 The rpcbind package to use.
23711 @item @code{warm-start?} (default: @code{#t})
23712 If this parameter is @code{#t}, then the daemon will read a
23713 state file on startup thus reloading state information saved by a previous
23719 @subsubheading Pipefs Pseudo File System
23723 The pipefs file system is used to transfer NFS related data
23724 between the kernel and user space programs.
23726 @defvr {Scheme Variable} pipefs-service-type
23727 A service type for the pipefs pseudo file system.
23730 @deftp {Data Type} pipefs-configuration
23731 Data type representing the configuration of the pipefs pseudo file system service.
23732 This type has the following parameters:
23734 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23735 The directory to which the file system is to be attached.
23740 @subsubheading GSS Daemon Service
23743 @cindex global security system
23745 The @dfn{global security system} (GSS) daemon provides strong security for RPC
23747 Before exchanging RPC requests an RPC client must establish a security
23748 context. Typically this is done using the Kerberos command @command{kinit}
23749 or automatically at login time using PAM services (@pxref{Kerberos Services}).
23751 @defvr {Scheme Variable} gss-service-type
23752 A service type for the Global Security System (GSS) daemon.
23755 @deftp {Data Type} gss-configuration
23756 Data type representing the configuration of the GSS daemon service.
23757 This type has the following parameters:
23759 @item @code{nfs-utils} (default: @code{nfs-utils})
23760 The package in which the @command{rpc.gssd} command is to be found.
23762 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23763 The directory where the pipefs file system is mounted.
23769 @subsubheading IDMAP Daemon Service
23771 @cindex name mapper
23773 The idmap daemon service provides mapping between user IDs and user names.
23774 Typically it is required in order to access file systems mounted via NFSv4.
23776 @defvr {Scheme Variable} idmap-service-type
23777 A service type for the Identity Mapper (IDMAP) daemon.
23780 @deftp {Data Type} idmap-configuration
23781 Data type representing the configuration of the IDMAP daemon service.
23782 This type has the following parameters:
23784 @item @code{nfs-utils} (default: @code{nfs-utils})
23785 The package in which the @command{rpc.idmapd} command is to be found.
23787 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23788 The directory where the pipefs file system is mounted.
23790 @item @code{domain} (default: @code{#f})
23791 The local NFSv4 domain name.
23792 This must be a string or @code{#f}.
23793 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
23795 @item @code{verbosity} (default: @code{0})
23796 The verbosity level of the daemon.
23801 @node Continuous Integration
23802 @subsection Continuous Integration
23804 @cindex continuous integration
23805 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
23806 continuous integration tool for Guix. It can be used both for development and
23807 for providing substitutes to others (@pxref{Substitutes}).
23809 The @code{(gnu services cuirass)} module provides the following service.
23811 @defvr {Scheme Procedure} cuirass-service-type
23812 The type of the Cuirass service. Its value must be a
23813 @code{cuirass-configuration} object, as described below.
23816 To add build jobs, you have to set the @code{specifications} field of the
23817 configuration. Here is an example of a service that polls the Guix repository
23818 and builds the packages from a manifest. Some of the packages are defined in
23819 the @code{"custom-packages"} input, which is the equivalent of
23820 @env{GUIX_PACKAGE_PATH}.
23823 (define %cuirass-specs
23825 '((#:name . "my-manifest")
23826 (#:load-path-inputs . ("guix"))
23827 (#:package-path-inputs . ("custom-packages"))
23828 (#:proc-input . "guix")
23829 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
23830 (#:proc . cuirass-jobs)
23831 (#:proc-args . ((subset . "manifests")
23832 (systems . ("x86_64-linux"))
23833 (manifests . (("config" . "guix/manifest.scm")))))
23834 (#:inputs . (((#:name . "guix")
23835 (#:url . "git://git.savannah.gnu.org/guix.git")
23836 (#:load-path . ".")
23837 (#:branch . "master")
23838 (#:no-compile? . #t))
23839 ((#:name . "config")
23840 (#:url . "https://git.example.org/config.git")
23841 (#:load-path . ".")
23842 (#:branch . "master")
23843 (#:no-compile? . #t))
23844 ((#:name . "custom-packages")
23845 (#:url . "https://git.example.org/custom-packages.git")
23846 (#:load-path . ".")
23847 (#:branch . "master")
23848 (#:no-compile? . #t)))))))
23850 (service cuirass-service-type
23851 (cuirass-configuration
23852 (specifications %cuirass-specs)))
23855 While information related to build jobs is located directly in the
23856 specifications, global settings for the @command{cuirass} process are
23857 accessible in other @code{cuirass-configuration} fields.
23859 @deftp {Data Type} cuirass-configuration
23860 Data type representing the configuration of Cuirass.
23863 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
23864 Location of the log file.
23866 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
23867 Location of the log file used by the web interface.
23869 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
23870 Location of the repository cache.
23872 @item @code{user} (default: @code{"cuirass"})
23873 Owner of the @code{cuirass} process.
23875 @item @code{group} (default: @code{"cuirass"})
23876 Owner's group of the @code{cuirass} process.
23878 @item @code{interval} (default: @code{60})
23879 Number of seconds between the poll of the repositories followed by the
23882 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
23883 Location of sqlite database which contains the build results and previously
23884 added specifications.
23886 @item @code{ttl} (default: @code{(* 30 24 3600)})
23887 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
23888 are registered for build results. This means that build results are protected
23889 from garbage collection for at least @var{ttl} seconds.
23891 @item @code{port} (default: @code{8081})
23892 Port number used by the HTTP server.
23894 @item @code{host} (default: @code{"localhost"})
23895 Listen on the network interface for @var{host}. The default is to
23896 accept connections from localhost.
23898 @item @code{specifications} (default: @code{#~'()})
23899 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
23900 where a specification is an association list
23901 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
23902 keys are keywords (@code{#:keyword-example}) as shown in the example
23905 @item @code{use-substitutes?} (default: @code{#f})
23906 This allows using substitutes to avoid building every dependencies of a job
23909 @item @code{one-shot?} (default: @code{#f})
23910 Only evaluate specifications and build derivations once.
23912 @item @code{fallback?} (default: @code{#f})
23913 When substituting a pre-built binary fails, fall back to building
23916 @item @code{extra-options} (default: @code{'()})
23917 Extra options to pass when running the Cuirass processes.
23919 @item @code{cuirass} (default: @code{cuirass})
23920 The Cuirass package to use.
23924 @node Power Management Services
23925 @subsection Power Management Services
23928 @cindex power management with TLP
23929 @subsubheading TLP daemon
23931 The @code{(gnu services pm)} module provides a Guix service definition
23932 for the Linux power management tool TLP.
23934 TLP enables various powersaving modes in userspace and kernel.
23935 Contrary to @code{upower-service}, it is not a passive,
23936 monitoring tool, as it will apply custom settings each time a new power
23937 source is detected. More information can be found at
23938 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
23940 @deffn {Scheme Variable} tlp-service-type
23941 The service type for the TLP tool. The default settings are optimised
23942 for battery life on most systems, but you can tweak them to your heart's
23943 content by adding a valid @code{tlp-configuration}:
23945 (service tlp-service-type
23947 (cpu-scaling-governor-on-ac (list "performance"))
23948 (sched-powersave-on-bat? #t)))
23952 Each parameter definition is preceded by its type; for example,
23953 @samp{boolean foo} indicates that the @code{foo} parameter
23954 should be specified as a boolean. Types starting with
23955 @code{maybe-} denote parameters that won't show up in TLP config file
23956 when their value is @code{'disabled}.
23958 @c The following documentation was initially generated by
23959 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
23960 @c documentation is better, so we shouldn't hesitate to edit below as
23961 @c needed. However if the change you want to make to this documentation
23962 @c can be done in an automated way, it's probably easier to change
23963 @c (generate-documentation) than to make it below and have to deal with
23964 @c the churn as TLP updates.
23966 Available @code{tlp-configuration} fields are:
23968 @deftypevr {@code{tlp-configuration} parameter} package tlp
23973 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
23974 Set to true if you wish to enable TLP.
23976 Defaults to @samp{#t}.
23980 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
23981 Default mode when no power supply can be detected. Alternatives are AC
23984 Defaults to @samp{"AC"}.
23988 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
23989 Number of seconds Linux kernel has to wait after the disk goes idle,
23990 before syncing on AC.
23992 Defaults to @samp{0}.
23996 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
23997 Same as @code{disk-idle-ac} but on BAT mode.
23999 Defaults to @samp{2}.
24003 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
24004 Dirty pages flushing periodicity, expressed in seconds.
24006 Defaults to @samp{15}.
24010 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
24011 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
24013 Defaults to @samp{60}.
24017 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
24018 CPU frequency scaling governor on AC mode. With intel_pstate driver,
24019 alternatives are powersave and performance. With acpi-cpufreq driver,
24020 alternatives are ondemand, powersave, performance and conservative.
24022 Defaults to @samp{disabled}.
24026 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
24027 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
24029 Defaults to @samp{disabled}.
24033 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
24034 Set the min available frequency for the scaling governor on AC.
24036 Defaults to @samp{disabled}.
24040 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
24041 Set the max available frequency for the scaling governor on AC.
24043 Defaults to @samp{disabled}.
24047 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
24048 Set the min available frequency for the scaling governor on BAT.
24050 Defaults to @samp{disabled}.
24054 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
24055 Set the max available frequency for the scaling governor on BAT.
24057 Defaults to @samp{disabled}.
24061 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
24062 Limit the min P-state to control the power dissipation of the CPU, in AC
24063 mode. Values are stated as a percentage of the available performance.
24065 Defaults to @samp{disabled}.
24069 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
24070 Limit the max P-state to control the power dissipation of the CPU, in AC
24071 mode. Values are stated as a percentage of the available performance.
24073 Defaults to @samp{disabled}.
24077 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
24078 Same as @code{cpu-min-perf-on-ac} on BAT mode.
24080 Defaults to @samp{disabled}.
24084 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
24085 Same as @code{cpu-max-perf-on-ac} on BAT mode.
24087 Defaults to @samp{disabled}.
24091 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
24092 Enable CPU turbo boost feature on AC mode.
24094 Defaults to @samp{disabled}.
24098 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
24099 Same as @code{cpu-boost-on-ac?} on BAT mode.
24101 Defaults to @samp{disabled}.
24105 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
24106 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
24107 used under light load conditions.
24109 Defaults to @samp{#f}.
24113 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
24114 Same as @code{sched-powersave-on-ac?} but on BAT mode.
24116 Defaults to @samp{#t}.
24120 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
24121 Enable Linux kernel NMI watchdog.
24123 Defaults to @samp{#f}.
24127 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
24128 For Linux kernels with PHC patch applied, change CPU voltages. An
24129 example value would be @samp{"F:V F:V F:V F:V"}.
24131 Defaults to @samp{disabled}.
24135 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
24136 Set CPU performance versus energy saving policy on AC. Alternatives are
24137 performance, normal, powersave.
24139 Defaults to @samp{"performance"}.
24143 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
24144 Same as @code{energy-perf-policy-ac} but on BAT mode.
24146 Defaults to @samp{"powersave"}.
24150 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
24155 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
24156 Hard disk advanced power management level.
24160 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
24161 Same as @code{disk-apm-bat} but on BAT mode.
24165 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
24166 Hard disk spin down timeout. One value has to be specified for each
24167 declared hard disk.
24169 Defaults to @samp{disabled}.
24173 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
24174 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
24176 Defaults to @samp{disabled}.
24180 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
24181 Select IO scheduler for disk devices. One value has to be specified for
24182 each declared hard disk. Example alternatives are cfq, deadline and
24185 Defaults to @samp{disabled}.
24189 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
24190 SATA aggressive link power management (ALPM) level. Alternatives are
24191 min_power, medium_power, max_performance.
24193 Defaults to @samp{"max_performance"}.
24197 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
24198 Same as @code{sata-linkpwr-ac} but on BAT mode.
24200 Defaults to @samp{"min_power"}.
24204 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
24205 Exclude specified SATA host devices for link power management.
24207 Defaults to @samp{disabled}.
24211 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
24212 Enable Runtime Power Management for AHCI controller and disks on AC
24215 Defaults to @samp{disabled}.
24219 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
24220 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
24222 Defaults to @samp{disabled}.
24226 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
24227 Seconds of inactivity before disk is suspended.
24229 Defaults to @samp{15}.
24233 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
24234 PCI Express Active State Power Management level. Alternatives are
24235 default, performance, powersave.
24237 Defaults to @samp{"performance"}.
24241 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
24242 Same as @code{pcie-aspm-ac} but on BAT mode.
24244 Defaults to @samp{"powersave"}.
24248 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
24249 Radeon graphics clock speed level. Alternatives are low, mid, high,
24252 Defaults to @samp{"high"}.
24256 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
24257 Same as @code{radeon-power-ac} but on BAT mode.
24259 Defaults to @samp{"low"}.
24263 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
24264 Radeon dynamic power management method (DPM). Alternatives are battery,
24267 Defaults to @samp{"performance"}.
24271 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
24272 Same as @code{radeon-dpm-state-ac} but on BAT mode.
24274 Defaults to @samp{"battery"}.
24278 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
24279 Radeon DPM performance level. Alternatives are auto, low, high.
24281 Defaults to @samp{"auto"}.
24285 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
24286 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
24288 Defaults to @samp{"auto"}.
24292 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
24293 Wifi power saving mode.
24295 Defaults to @samp{#f}.
24299 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
24300 Same as @code{wifi-power-ac?} but on BAT mode.
24302 Defaults to @samp{#t}.
24306 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
24307 Disable wake on LAN.
24309 Defaults to @samp{#t}.
24313 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
24314 Timeout duration in seconds before activating audio power saving on
24315 Intel HDA and AC97 devices. A value of 0 disables power saving.
24317 Defaults to @samp{0}.
24321 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
24322 Same as @code{sound-powersave-ac} but on BAT mode.
24324 Defaults to @samp{1}.
24328 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
24329 Disable controller in powersaving mode on Intel HDA devices.
24331 Defaults to @samp{#t}.
24335 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
24336 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
24337 powered on again by releasing (and reinserting) the eject lever or by
24338 pressing the disc eject button on newer models.
24340 Defaults to @samp{#f}.
24344 @deftypevr {@code{tlp-configuration} parameter} string bay-device
24345 Name of the optical drive device to power off.
24347 Defaults to @samp{"sr0"}.
24351 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
24352 Runtime Power Management for PCI(e) bus devices. Alternatives are on
24355 Defaults to @samp{"on"}.
24359 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
24360 Same as @code{runtime-pm-ac} but on BAT mode.
24362 Defaults to @samp{"auto"}.
24366 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
24367 Runtime Power Management for all PCI(e) bus devices, except blacklisted
24370 Defaults to @samp{#t}.
24374 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
24375 Exclude specified PCI(e) device addresses from Runtime Power Management.
24377 Defaults to @samp{disabled}.
24381 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
24382 Exclude PCI(e) devices assigned to the specified drivers from Runtime
24387 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
24388 Enable USB autosuspend feature.
24390 Defaults to @samp{#t}.
24394 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
24395 Exclude specified devices from USB autosuspend.
24397 Defaults to @samp{disabled}.
24401 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
24402 Exclude WWAN devices from USB autosuspend.
24404 Defaults to @samp{#t}.
24408 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
24409 Include specified devices into USB autosuspend, even if they are already
24410 excluded by the driver or via @code{usb-blacklist-wwan?}.
24412 Defaults to @samp{disabled}.
24416 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
24417 Enable USB autosuspend before shutdown.
24419 Defaults to @samp{disabled}.
24423 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
24424 Restore radio device state (bluetooth, wifi, wwan) from previous
24425 shutdown on system startup.
24427 Defaults to @samp{#f}.
24432 @cindex CPU frequency scaling with thermald
24433 @subsubheading Thermald daemon
24435 The @code{(gnu services pm)} module provides an interface to
24436 thermald, a CPU frequency scaling service which helps prevent overheating.
24438 @defvr {Scheme Variable} thermald-service-type
24439 This is the service type for
24440 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
24441 Thermal Daemon, which is responsible for controlling the thermal state
24442 of processors and preventing overheating.
24445 @deftp {Data Type} thermald-configuration
24446 Data type representing the configuration of @code{thermald-service-type}.
24449 @item @code{ignore-cpuid-check?} (default: @code{#f})
24450 Ignore cpuid check for supported CPU models.
24452 @item @code{thermald} (default: @var{thermald})
24453 Package object of thermald.
24458 @node Audio Services
24459 @subsection Audio Services
24461 The @code{(gnu services audio)} module provides a service to start MPD
24462 (the Music Player Daemon).
24465 @subsubheading Music Player Daemon
24467 The Music Player Daemon (MPD) is a service that can play music while
24468 being controlled from the local machine or over the network by a variety
24471 The following example shows how one might run @code{mpd} as user
24472 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
24475 (service mpd-service-type
24481 @defvr {Scheme Variable} mpd-service-type
24482 The service type for @command{mpd}
24485 @deftp {Data Type} mpd-configuration
24486 Data type representing the configuration of @command{mpd}.
24489 @item @code{user} (default: @code{"mpd"})
24490 The user to run mpd as.
24492 @item @code{music-dir} (default: @code{"~/Music"})
24493 The directory to scan for music files.
24495 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
24496 The directory to store playlists.
24498 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
24499 The location of the music database.
24501 @item @code{state-file} (default: @code{"~/.mpd/state"})
24502 The location of the file that stores current MPD's state.
24504 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
24505 The location of the sticker database.
24507 @item @code{port} (default: @code{"6600"})
24508 The port to run mpd on.
24510 @item @code{address} (default: @code{"any"})
24511 The address that mpd will bind to. To use a Unix domain socket,
24512 an absolute path can be specified here.
24514 @item @code{outputs} (default: @code{"(list (mpd-output))"})
24515 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
24520 @deftp {Data Type} mpd-output
24521 Data type representing an @command{mpd} audio output.
24524 @item @code{name} (default: @code{"MPD"})
24525 The name of the audio output.
24527 @item @code{type} (default: @code{"pulse"})
24528 The type of audio output.
24530 @item @code{enabled?} (default: @code{#t})
24531 Specifies whether this audio output is enabled when MPD is started. By
24532 default, all audio outputs are enabled. This is just the default
24533 setting when there is no state file; with a state file, the previous
24536 @item @code{tags?} (default: @code{#t})
24537 If set to @code{#f}, then MPD will not send tags to this output. This
24538 is only useful for output plugins that can receive tags, for example the
24539 @code{httpd} output plugin.
24541 @item @code{always-on?} (default: @code{#f})
24542 If set to @code{#t}, then MPD attempts to keep this audio output always
24543 open. This may be useful for streaming servers, when you don’t want to
24544 disconnect all listeners even when playback is accidentally stopped.
24546 @item @code{mixer-type}
24547 This field accepts a symbol that specifies which mixer should be used
24548 for this audio output: the @code{hardware} mixer, the @code{software}
24549 mixer, the @code{null} mixer (allows setting the volume, but with no
24550 effect; this can be used as a trick to implement an external mixer
24551 External Mixer) or no mixer (@code{none}).
24553 @item @code{extra-options} (default: @code{'()"})
24554 An association list of option symbols to string values to be appended to
24555 the audio output configuration.
24560 The following example shows a configuration of @code{mpd} that provides
24561 an HTTP audio streaming output.
24564 (service mpd-service-type
24572 `((encoder . "vorbis")
24573 (port . "8080"))))))))
24577 @node Virtualization Services
24578 @subsection Virtualization services
24580 The @code{(gnu services virtualization)} module provides services for
24581 the libvirt and virtlog daemons, as well as other virtualization-related
24584 @subsubheading Libvirt daemon
24585 @code{libvirtd} is the server side daemon component of the libvirt
24586 virtualization management system. This daemon runs on host servers
24587 and performs required management tasks for virtualized guests.
24589 @deffn {Scheme Variable} libvirt-service-type
24590 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
24591 Its value must be a @code{libvirt-configuration}.
24594 (service libvirt-service-type
24595 (libvirt-configuration
24596 (unix-sock-group "libvirt")
24597 (tls-port "16555")))
24601 @c Auto-generated with (generate-libvirt-documentation)
24602 Available @code{libvirt-configuration} fields are:
24604 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
24609 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
24610 Flag listening for secure TLS connections on the public TCP/IP port.
24611 must set @code{listen} for this to have any effect.
24613 It is necessary to setup a CA and issue server certificates before using
24616 Defaults to @samp{#t}.
24620 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
24621 Listen for unencrypted TCP connections on the public TCP/IP port. must
24622 set @code{listen} for this to have any effect.
24624 Using the TCP socket requires SASL authentication by default. Only SASL
24625 mechanisms which support data encryption are allowed. This is
24626 DIGEST_MD5 and GSSAPI (Kerberos5)
24628 Defaults to @samp{#f}.
24632 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
24633 Port for accepting secure TLS connections This can be a port number, or
24636 Defaults to @samp{"16514"}.
24640 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
24641 Port for accepting insecure TCP connections This can be a port number,
24644 Defaults to @samp{"16509"}.
24648 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
24649 IP address or hostname used for client connections.
24651 Defaults to @samp{"0.0.0.0"}.
24655 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
24656 Flag toggling mDNS advertisement of the libvirt service.
24658 Alternatively can disable for all services on a host by stopping the
24661 Defaults to @samp{#f}.
24665 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
24666 Default mDNS advertisement name. This must be unique on the immediate
24669 Defaults to @samp{"Virtualization Host <hostname>"}.
24673 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
24674 UNIX domain socket group ownership. This can be used to allow a
24675 'trusted' set of users access to management capabilities without
24678 Defaults to @samp{"root"}.
24682 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
24683 UNIX socket permissions for the R/O socket. This is used for monitoring
24686 Defaults to @samp{"0777"}.
24690 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
24691 UNIX socket permissions for the R/W socket. Default allows only root.
24692 If PolicyKit is enabled on the socket, the default will change to allow
24693 everyone (eg, 0777)
24695 Defaults to @samp{"0770"}.
24699 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
24700 UNIX socket permissions for the admin socket. Default allows only owner
24701 (root), do not change it unless you are sure to whom you are exposing
24704 Defaults to @samp{"0777"}.
24708 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
24709 The directory in which sockets will be found/created.
24711 Defaults to @samp{"/var/run/libvirt"}.
24715 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
24716 Authentication scheme for UNIX read-only sockets. By default socket
24717 permissions allow anyone to connect
24719 Defaults to @samp{"polkit"}.
24723 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
24724 Authentication scheme for UNIX read-write sockets. By default socket
24725 permissions only allow root. If PolicyKit support was compiled into
24726 libvirt, the default will be to use 'polkit' auth.
24728 Defaults to @samp{"polkit"}.
24732 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
24733 Authentication scheme for TCP sockets. If you don't enable SASL, then
24734 all TCP traffic is cleartext. Don't do this outside of a dev/test
24737 Defaults to @samp{"sasl"}.
24741 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
24742 Authentication scheme for TLS sockets. TLS sockets already have
24743 encryption provided by the TLS layer, and limited authentication is done
24746 It is possible to make use of any SASL authentication mechanism as well,
24747 by using 'sasl' for this option
24749 Defaults to @samp{"none"}.
24753 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
24754 API access control scheme.
24756 By default an authenticated user is allowed access to all APIs. Access
24757 drivers can place restrictions on this.
24759 Defaults to @samp{()}.
24763 @deftypevr {@code{libvirt-configuration} parameter} string key-file
24764 Server key file path. If set to an empty string, then no private key is
24767 Defaults to @samp{""}.
24771 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
24772 Server key file path. If set to an empty string, then no certificate is
24775 Defaults to @samp{""}.
24779 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
24780 Server key file path. If set to an empty string, then no CA certificate
24783 Defaults to @samp{""}.
24787 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
24788 Certificate revocation list path. If set to an empty string, then no
24791 Defaults to @samp{""}.
24795 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
24796 Disable verification of our own server certificates.
24798 When libvirtd starts it performs some sanity checks against its own
24801 Defaults to @samp{#f}.
24805 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
24806 Disable verification of client certificates.
24808 Client certificate verification is the primary authentication mechanism.
24809 Any client which does not present a certificate signed by the CA will be
24812 Defaults to @samp{#f}.
24816 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
24817 Whitelist of allowed x509 Distinguished Name.
24819 Defaults to @samp{()}.
24823 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
24824 Whitelist of allowed SASL usernames. The format for username depends on
24825 the SASL authentication mechanism.
24827 Defaults to @samp{()}.
24831 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
24832 Override the compile time default TLS priority string. The default is
24833 usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
24834 is desired for libvirt to deviate from the global default settings.
24836 Defaults to @samp{"NORMAL"}.
24840 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
24841 Maximum number of concurrent client connections to allow over all
24844 Defaults to @samp{5000}.
24848 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
24849 Maximum length of queue of connections waiting to be accepted by the
24850 daemon. Note, that some protocols supporting retransmission may obey
24851 this so that a later reattempt at connection succeeds.
24853 Defaults to @samp{1000}.
24857 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
24858 Maximum length of queue of accepted but not yet authenticated clients.
24859 Set this to zero to turn this feature off
24861 Defaults to @samp{20}.
24865 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
24866 Number of workers to start up initially.
24868 Defaults to @samp{5}.
24872 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
24873 Maximum number of worker threads.
24875 If the number of active clients exceeds @code{min-workers}, then more
24876 threads are spawned, up to max_workers limit. Typically you'd want
24877 max_workers to equal maximum number of clients allowed.
24879 Defaults to @samp{20}.
24883 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
24884 Number of priority workers. If all workers from above pool are stuck,
24885 some calls marked as high priority (notably domainDestroy) can be
24886 executed in this pool.
24888 Defaults to @samp{5}.
24892 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
24893 Total global limit on concurrent RPC calls.
24895 Defaults to @samp{20}.
24899 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
24900 Limit on concurrent requests from a single client connection. To avoid
24901 one client monopolizing the server this should be a small fraction of
24902 the global max_requests and max_workers parameter.
24904 Defaults to @samp{5}.
24908 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
24909 Same as @code{min-workers} but for the admin interface.
24911 Defaults to @samp{1}.
24915 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
24916 Same as @code{max-workers} but for the admin interface.
24918 Defaults to @samp{5}.
24922 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
24923 Same as @code{max-clients} but for the admin interface.
24925 Defaults to @samp{5}.
24929 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
24930 Same as @code{max-queued-clients} but for the admin interface.
24932 Defaults to @samp{5}.
24936 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
24937 Same as @code{max-client-requests} but for the admin interface.
24939 Defaults to @samp{5}.
24943 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
24944 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
24946 Defaults to @samp{3}.
24950 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
24953 A filter allows to select a different logging level for a given category
24954 of logs The format for a filter is one of:
24965 where @code{name} is a string which is matched against the category
24966 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
24967 file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
24968 name in the filter can be a substring of the full category name, in
24969 order to match multiple similar categories), the optional @samp{"+"}
24970 prefix tells libvirt to log stack trace for each message matching name,
24971 and @code{x} is the minimal level where matching messages should be
24989 Multiple filters can be defined in a single filters statement, they just
24990 need to be separated by spaces.
24992 Defaults to @samp{"3:remote 4:event"}.
24996 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
24999 An output is one of the places to save logging information. The format
25000 for an output can be:
25004 output goes to stderr
25006 @item x:syslog:name
25007 use syslog for the output and use the given name as the ident
25009 @item x:file:file_path
25010 output to a file, with the given filepath
25013 output to journald logging system
25017 In all case the x prefix is the minimal level, acting as a filter
25034 Multiple outputs can be defined, they just need to be separated by
25037 Defaults to @samp{"3:stderr"}.
25041 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
25042 Allows usage of the auditing subsystem to be altered
25046 0: disable all auditing
25049 1: enable auditing, only if enabled on host
25052 2: enable auditing, and exit if disabled on host.
25056 Defaults to @samp{1}.
25060 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
25061 Send audit messages via libvirt logging infrastructure.
25063 Defaults to @samp{#f}.
25067 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
25068 Host UUID. UUID must not have all digits be the same.
25070 Defaults to @samp{""}.
25074 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
25075 Source to read host UUID.
25079 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
25082 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
25086 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
25089 Defaults to @samp{"smbios"}.
25093 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
25094 A keepalive message is sent to a client after @code{keepalive_interval}
25095 seconds of inactivity to check if the client is still responding. If
25096 set to -1, libvirtd will never send keepalive requests; however clients
25097 can still send them and the daemon will send responses.
25099 Defaults to @samp{5}.
25103 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
25104 Maximum number of keepalive messages that are allowed to be sent to the
25105 client without getting any response before the connection is considered
25108 In other words, the connection is automatically closed approximately
25109 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
25110 the last message received from the client. When @code{keepalive-count}
25111 is set to 0, connections will be automatically closed after
25112 @code{keepalive-interval} seconds of inactivity without sending any
25113 keepalive messages.
25115 Defaults to @samp{5}.
25119 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
25120 Same as above but for admin interface.
25122 Defaults to @samp{5}.
25126 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
25127 Same as above but for admin interface.
25129 Defaults to @samp{5}.
25133 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
25134 Timeout for Open vSwitch calls.
25136 The @code{ovs-vsctl} utility is used for the configuration and its
25137 timeout option is set by default to 5 seconds to avoid potential
25138 infinite waits blocking libvirt.
25140 Defaults to @samp{5}.
25144 @c %end of autogenerated docs
25146 @subsubheading Virtlog daemon
25147 The virtlogd service is a server side daemon component of libvirt that is
25148 used to manage logs from virtual machine consoles.
25150 This daemon is not used directly by libvirt client applications, rather it
25151 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
25152 standalone daemon, the main @code{libvirtd} daemon can be restarted without
25153 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
25154 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
25156 @deffn {Scheme Variable} virtlog-service-type
25157 This is the type of the virtlog daemon.
25158 Its value must be a @code{virtlog-configuration}.
25161 (service virtlog-service-type
25162 (virtlog-configuration
25163 (max-clients 1000)))
25167 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
25168 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
25170 Defaults to @samp{3}.
25174 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
25177 A filter allows to select a different logging level for a given category
25178 of logs The format for a filter is one of:
25189 where @code{name} is a string which is matched against the category
25190 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
25191 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
25192 be a substring of the full category name, in order to match multiple
25193 similar categories), the optional "+" prefix tells libvirt to log stack
25194 trace for each message matching name, and @code{x} is the minimal level
25195 where matching messages should be logged:
25212 Multiple filters can be defined in a single filters statement, they just
25213 need to be separated by spaces.
25215 Defaults to @samp{"3:remote 4:event"}.
25219 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
25222 An output is one of the places to save logging information The format
25223 for an output can be:
25227 output goes to stderr
25229 @item x:syslog:name
25230 use syslog for the output and use the given name as the ident
25232 @item x:file:file_path
25233 output to a file, with the given filepath
25236 output to journald logging system
25240 In all case the x prefix is the minimal level, acting as a filter
25257 Multiple outputs can be defined, they just need to be separated by
25260 Defaults to @samp{"3:stderr"}.
25264 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
25265 Maximum number of concurrent client connections to allow over all
25268 Defaults to @samp{1024}.
25272 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
25273 Maximum file size before rolling over.
25275 Defaults to @samp{2MB}
25279 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
25280 Maximum number of backup files to keep.
25282 Defaults to @samp{3}
25285 @node Transparent Emulation with QEMU
25286 @subsubheading Transparent Emulation with QEMU
25289 @cindex @code{binfmt_misc}
25290 @code{qemu-binfmt-service-type} provides support for transparent
25291 emulation of program binaries built for different architectures---e.g.,
25292 it allows you to transparently execute an ARMv7 program on an x86_64
25293 machine. It achieves this by combining the @uref{https://www.qemu.org,
25294 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
25296 @defvr {Scheme Variable} qemu-binfmt-service-type
25297 This is the type of the QEMU/binfmt service for transparent emulation.
25298 Its value must be a @code{qemu-binfmt-configuration} object, which
25299 specifies the QEMU package to use as well as the architecture we want to
25303 (service qemu-binfmt-service-type
25304 (qemu-binfmt-configuration
25305 (platforms (lookup-qemu-platforms "arm" "aarch64"))))
25308 In this example, we enable transparent emulation for the ARM and aarch64
25309 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
25310 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
25311 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
25314 @deftp {Data Type} qemu-binfmt-configuration
25315 This is the configuration for the @code{qemu-binfmt} service.
25318 @item @code{platforms} (default: @code{'()})
25319 The list of emulated QEMU platforms. Each item must be a @dfn{platform
25320 object} as returned by @code{lookup-qemu-platforms} (see below).
25322 @item @code{guix-support?} (default: @code{#f})
25323 When it is true, QEMU and all its dependencies are added to the build
25324 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
25325 @option{--chroot-directory} option}). This allows the @code{binfmt_misc}
25326 handlers to be used within the build environment, which in turn means
25327 that you can transparently build programs for another architecture.
25329 For example, let's suppose you're on an x86_64 machine and you have this
25333 (service qemu-binfmt-service-type
25334 (qemu-binfmt-configuration
25335 (platforms (lookup-qemu-platforms "arm"))
25336 (guix-support? #t)))
25342 guix build -s armhf-linux inkscape
25346 and it will build Inkscape for ARMv7 @emph{as if it were a native
25347 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
25348 if you'd like to test a package build for an architecture you don't have
25351 @item @code{qemu} (default: @code{qemu})
25352 The QEMU package to use.
25356 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
25357 Return the list of QEMU platform objects corresponding to
25358 @var{platforms}@dots{}. @var{platforms} must be a list of strings
25359 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
25360 @code{"mips64el"}, and so on.
25363 @deffn {Scheme Procedure} qemu-platform? @var{obj}
25364 Return true if @var{obj} is a platform object.
25367 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
25368 Return the name of @var{platform}---a string such as @code{"arm"}.
25372 @subsubheading The Hurd in a Virtual Machine
25374 @cindex @code{hurd}
25378 Service @code{hurd-vm} provides support for running GNU/Hurd in a
25379 virtual machine (VM), a so-called ``Childhurd''. The virtual machine is
25380 a Shepherd service that can be referred to by the names @code{hurd-vm}
25381 and @code{childhurd} and be controlled with commands such as:
25385 herd stop childhurd
25388 The given GNU/Hurd operating system configuration is cross-compiled.
25390 @defvr {Scheme Variable} hurd-vm-service-type
25391 This is the type of the Hurd in a Virtual Machine service. Its value
25392 must be a @code{hurd-vm-configuration} object, which specifies the
25393 operating system (@pxref{operating-system Reference}) and the disk size
25394 for the Hurd Virtual Machine, the QEMU package to use as well as the
25395 options for running it.
25400 (service hurd-vm-service-type
25401 (hurd-vm-configuration
25402 (disk-size (* 5000 (expt 2 20))) ;5G
25403 (memory-size 1024))) ;1024MiB
25406 would create a disk image big enough to build GNU@tie{}Hello, with some
25410 @deftp {Data Type} hurd-vm-configuration
25411 The data type representing the configuration for
25412 @code{hurd-vm-service-type}.
25415 @item @code{os} (default: @var{%hurd-vm-operating-system})
25416 The operating system to instantiate. This default is bare-bones with a
25417 permissive OpenSSH secure shell daemon listening on port 2222
25418 (@pxref{Networking Services, @code{openssh-service-type}}).
25420 @item @code{qemu} (default: @code{qemu-minimal})
25421 The QEMU package to use.
25423 @item @code{image} (default: @var{hurd-vm-disk-image})
25424 The procedure used to build the disk-image built from this
25427 @item @code{disk-size} (default: @code{'guess})
25428 The size of the disk image.
25430 @item @code{memory-size} (default: @code{512})
25431 The memory size of the Virtual Machine in mebibytes.
25433 @item @code{options} (default: @code{'("--snapshot")})
25434 The extra options for running QEMU.
25436 @item @code{id} (default: @code{#f})
25437 If set, a non-zero positive integer used to parameterize Childhurd
25438 instances. It is appended to the service's name,
25439 e.g. @code{childhurd1}.
25441 @item @code{net-options} (default: @var{hurd-vm-net-options})
25442 The procedure used to produce the list of QEMU networking options.
25444 By default, it produces
25447 '("--device" "rtl8139,netdev=net0"
25448 "--netdev" "user,id=net0\
25449 ,hostfwd=tcp:127.0.0.1:<secrets-port>-:1004\
25450 ,hostfwd=tcp:127.0.0.1:<ssh-port>-:2222\
25451 ,hostfwd=tcp:127.0.0.1:<vnc-port>-:5900")
25453 with forwarded ports
25455 <ssh-port>: @code{(+ 11004 (* 1000 @var{ID}))}
25456 <ssh-port>: @code{(+ 10022 (* 1000 @var{ID}))}
25457 <vnc-port>: @code{(+ 15900 (* 1000 @var{ID}))}
25460 @item @code{secret-root} (default: @file{/etc/childhurd})
25461 The root directory with out-of-band secrets to be installed into the
25462 childhurd once it runs. Childhurds are volatile which means that on
25463 every startup, secrets such as the SSH host keys and Guix signing key
25466 If the @file{/etc/childhurd} directory does not exist, the
25467 @code{secret-service} running in the Childhurd will be sent an empty
25470 Typical use to populate @file{"/etc/childhurd"} with a tree of
25471 non-volatile secrets, like so
25474 /etc/childhurd/etc/guix/signing-key.pub
25475 /etc/childhurd/etc/guix/signing-key.sec
25476 /etc/childhurd/etc/ssh/ssh_host_ed25519_key
25477 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key
25478 /etc/childhurd/etc/ssh/ssh_host_ed25519_key.pub
25479 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key.pub
25482 to be sent to the Childhurd, including permissions.
25487 Note that by default the VM image is volatile, i.e., once stopped the
25488 contents are lost. If you want a stateful image instead, override the
25489 configuration's @code{image} and @code{options} without
25490 the @code{--snapshot} flag using something along these lines:
25493 (service hurd-vm-service-type
25494 (hurd-vm-configuration
25495 (image (const "/out/of/store/writable/hurd.img"))
25496 (options '("--hda"))))
25499 @subsubheading Ganeti
25504 This service is considered experimental. Configuration options may be changed
25505 in a backwards-incompatible manner, and not all features have been thorougly
25506 tested. Users of this service are encouraged to share their experience at
25507 @email{guix-devel@@gnu.org}.
25510 Ganeti is a virtual machine management system. It is designed to keep virtual
25511 machines running on a cluster of servers even in the event of hardware failures,
25512 and to make maintenance and recovery tasks easy. It consists of multiple
25513 services which are described later in this section. In addition to the Ganeti
25514 service, you will need the OpenSSH service (@pxref{Networking Services,
25515 @code{openssh-service-type}}), and update the @file{/etc/hosts} file
25516 (@pxref{operating-system Reference, @code{hosts-file}}) with the cluster name
25517 and address (or use a DNS server).
25519 All nodes participating in a Ganeti cluster should have the same Ganeti and
25520 @file{/etc/hosts} configuration. Here is an example configuration for a Ganeti
25521 cluster node that supports multiple storage backends, and installs the
25522 @code{debootstrap} and @code{guix} @dfn{OS providers}:
25525 (use-package-modules virtualization)
25526 (use-service-modules base ganeti networking ssh)
25529 (host-name "node1")
25530 (hosts-file (plain-file "hosts" (format #f "
25531 127.0.0.1 localhost
25534 192.168.1.200 ganeti.example.com
25535 192.168.1.201 node1.example.com node1
25536 192.168.1.202 node2.example.com node2
25539 ;; Install QEMU so we can use KVM-based instances, and LVM, DRBD and Ceph
25540 ;; in order to use the "plain", "drbd" and "rbd" storage backends.
25541 (packages (append (map specification->package
25542 '("qemu" "lvm2" "drbd-utils" "ceph"
25543 ;; Add the debootstrap and guix OS providers.
25544 "ganeti-instance-guix" "ganeti-instance-debootstrap"))
25547 (append (list (static-networking-service "eth0" "192.168.1.201"
25548 #:netmask "255.255.255.0"
25549 #:gateway "192.168.1.254"
25550 #:name-servers '("192.168.1.252"
25553 ;; Ganeti uses SSH to communicate between nodes.
25554 (service openssh-service-type
25555 (openssh-configuration
25556 (permit-root-login 'without-password)))
25558 (service ganeti-service-type
25559 (ganeti-configuration
25560 ;; This list specifies allowed file system paths
25561 ;; for storing virtual machine images.
25562 (file-storage-paths '("/srv/ganeti/file-storage"))
25563 ;; This variable configures a single "variant" for
25564 ;; both Debootstrap and Guix that works with KVM.
25565 (os %default-ganeti-os))))
25569 Users are advised to read the
25570 @url{http://docs.ganeti.org/ganeti/master/html/admin.html,Ganeti
25571 administrators guide} to learn about the various cluster options and
25572 day-to-day operations. There is also a
25573 @url{https://guix.gnu.org/blog/2020/running-a-ganeti-cluster-on-guix/,blog post}
25574 describing how to configure and initialize a small cluster.
25576 @defvr {Scheme Variable} ganeti-service-type
25577 This is a service type that includes all the various services that Ganeti
25580 Its value is a @code{ganeti-configuration} object that defines the package
25581 to use for CLI operations, as well as configuration for the various daemons.
25582 Allowed file storage paths and available guest operating systems are also
25583 configured through this data type.
25586 @deftp {Data Type} ganeti-configuration
25587 The @code{ganeti} service takes the following configuration options:
25590 @item @code{ganeti} (default: @code{ganeti})
25591 The @code{ganeti} package to use. It will be installed to the system profile
25592 and make @command{gnt-cluster}, @command{gnt-instance}, etc available. Note
25593 that the value specified here does not affect the other services as each refer
25594 to a specific @code{ganeti} package (see below).
25596 @item @code{noded-configuration} (default: @code{(ganeti-noded-configuration)})
25597 @itemx @code{confd-configuration} (default: @code{(ganeti-confd-configuration)})
25598 @itemx @code{wconfd-configuration} (default: @code{(ganeti-wconfd-configuration)})
25599 @itemx @code{luxid-configuration} (default: @code{(ganeti-luxid-configuration)})
25600 @itemx @code{rapi-configuration} (default: @code{(ganeti-rapi-configuration)})
25601 @itemx @code{kvmd-configuration} (default: @code{(ganeti-kvmd-configuration)})
25602 @itemx @code{mond-configuration} (default: @code{(ganeti-mond-configuration)})
25603 @itemx @code{metad-configuration} (default: @code{(ganeti-metad-configuration)})
25604 @itemx @code{watcher-configuration} (default: @code{(ganeti-watcher-configuration)})
25605 @itemx @code{cleaner-configuration} (default: @code{(ganeti-cleaner-configuration)})
25607 These options control the various daemons and cron jobs that are distributed
25608 with Ganeti. The possible values for these are described in detail below.
25609 To override a setting, you must use the configuration type for that service:
25612 (service ganeti-service-type
25613 (ganeti-configuration
25614 (rapi-configuration
25615 (ganeti-rapi-configuration
25616 (interface "eth1"))))
25617 (watcher-configuration
25618 (ganeti-watcher-configuration
25619 (rapi-ip "10.0.0.1"))))
25622 @item @code{file-storage-paths} (default: @code{'()})
25623 List of allowed directories for file storage backend.
25625 @item @code{os} (default: @code{%default-ganeti-os})
25626 List of @code{<ganeti-os>} records.
25629 In essence @code{ganeti-service-type} is shorthand for declaring each service
25633 (service ganeti-noded-service-type)
25634 (service ganeti-confd-service-type)
25635 (service ganeti-wconfd-service-type)
25636 (service ganeti-luxid-service-type)
25637 (service ganeti-kvmd-service-type)
25638 (service ganeti-mond-service-type)
25639 (service ganeti-metad-service-type)
25640 (service ganeti-watcher-service-type)
25641 (service ganeti-cleaner-service-type)
25644 Plus a service extension for @code{etc-service-type} that configures the file
25645 storage backend and OS variants.
25649 @deftp {Data Type} ganeti-os
25650 This data type is suitable for passing to the @code{os} parameter of
25651 @code{ganeti-configuration}. It takes the following parameters:
25655 The name for this OS provider. It is only used to specify where the
25656 configuration ends up. Setting it to ``debootstrap'' will create
25657 @file{/etc/ganeti/instance-debootstrap}.
25659 @item @code{extension}
25660 The file extension for variants of this OS type. For example
25661 @file{.conf} or @file{.scm}.
25663 @item @code{variants} (default: @code{'()})
25664 List of @code{ganeti-os-variant} objects for this OS.
25669 @deftp {Data Type} ganeti-os-variant
25670 This is the data type for a Ganeti OS variant. It takes the following
25675 The name of this variant.
25677 @item @code{configuration}
25678 A configuration file for this variant.
25682 @defvr {Scheme Variable} %default-debootstrap-hooks
25683 This variable contains hooks to configure networking and the GRUB bootloader.
25686 @defvr {Scheme Variable} %default-debootstrap-extra-pkgs
25687 This variable contains a list of packages suitable for a fully-virtualized guest.
25690 @deftp {Data Type} debootstrap-configuration
25692 This data type creates configuration files suitable for the debootstrap OS provider.
25695 @item @code{hooks} (default: @code{%default-debootstrap-hooks})
25696 When not @code{#f}, this must be a G-expression that specifies a directory with
25697 scripts that will run when the OS is installed. It can also be a list of
25698 @code{(name . file-like)} pairs. For example:
25701 `((99-hello-world . ,(plain-file "#!/bin/sh\necho Hello, World")))
25704 That will create a directory with one executable named @code{99-hello-world}
25705 and run it every time this variant is installed. If set to @code{#f}, hooks
25706 in @file{/etc/ganeti/instance-debootstrap/hooks} will be used, if any.
25707 @item @code{proxy} (default: @code{#f})
25708 Optional HTTP proxy to use.
25709 @item @code{mirror} (default: @code{#f})
25710 The Debian mirror. Typically something like @code{http://ftp.no.debian.org/debian}.
25711 The default varies depending on the distribution.
25712 @item @code{arch} (default: @code{#f})
25713 The dpkg architecture. Set to @code{armhf} to debootstrap an ARMv7 instance
25714 on an AArch64 host. Default is to use the current system architecture.
25715 @item @code{suite} (default: @code{"stable"})
25716 When set, this must be a Debian distribution ``suite'' such as @code{buster}
25717 or @code{focal}. If set to @code{#f}, the default for the OS provider is used.
25718 @item @code{extra-pkgs} (default: @code{%default-debootstrap-extra-pkgs})
25719 List of extra packages that will get installed by dpkg in addition
25720 to the minimal system.
25721 @item @code{components} (default: @code{#f})
25722 When set, must be a list of Debian repository ``components''. For example
25723 @code{'("main" "contrib")}.
25724 @item @code{generate-cache?} (default: @code{#t})
25725 Whether to automatically cache the generated debootstrap archive.
25726 @item @code{clean-cache} (default: @code{14})
25727 Discard the cache after this amount of days. Use @code{#f} to never
25729 @item @code{partition-style} (default: @code{'msdos})
25730 The type of partition to create. When set, it must be one of
25731 @code{'msdos}, @code{'none} or a string.
25732 @item @code{partition-alignment} (default: @code{2048})
25733 Alignment of the partition in sectors.
25737 @deffn {Scheme Procedure} debootstrap-variant @var{name} @var{configuration}
25738 This is a helper procedure that creates a @code{ganeti-os-variant} record. It
25739 takes two parameters: a name and a @code{debootstrap-configuration} object.
25742 @deffn {Scheme Procedure} debootstrap-os @var{variants}@dots{}
25743 This is a helper procedure that creates a @code{ganeti-os} record. It takes
25744 a list of variants created with @code{debootstrap-variant}.
25747 @deffn {Scheme Procedure} guix-variant @var{name} @var{configuration}
25748 This is a helper procedure that creates a @code{ganeti-os-variant} record for
25749 use with the Guix OS provider. It takes a name and a G-expression that returns
25750 a ``file-like'' (@pxref{G-Expressions, file-like objects}) object containing a
25751 Guix System configuration.
25754 @deffn {Scheme Procedure} guix-os @var{variants}@dots{}
25755 This is a helper procedure that creates a @code{ganeti-os} record. It
25756 takes a list of variants produced by @code{guix-variant}.
25759 @defvr {Scheme Variable} %default-debootstrap-variants
25760 This is a convenience variable to make the debootstrap provider work
25761 ``out of the box'' without users having to declare variants manually. It
25762 contains a single debootstrap variant with the default configuration:
25765 (list (debootstrap-variant
25767 (debootstrap-configuration)))
25771 @defvr {Scheme Variable} %default-guix-variants
25772 This is a convenience variable to make the Guix OS provider work without
25773 additional configuration. It creates a virtual machine that has an SSH
25774 server, a serial console, and authorizes the Ganeti hosts SSH keys.
25777 (list (guix-variant
25779 (file-append ganeti-instance-guix
25780 "/share/doc/ganeti-instance-guix/examples/dynamic.scm")))
25784 Users can implement support for OS providers unbeknownst to Guix by extending
25785 the @code{ganeti-os} and @code{ganeti-os-variant} records appropriately.
25791 (extension ".conf")
25793 (list (ganeti-os-variant
25795 (configuration (plain-file "bar" "this is fine"))))))
25798 That creates @file{/etc/ganeti/instance-custom/variants/foo.conf} which points
25799 to a file in the store with contents @code{this is fine}. It also creates
25800 @file{/etc/ganeti/instance-custom/variants/variants.list} with contents @code{foo}.
25802 Obviously this may not work for all OS providers out there. If you find the
25803 interface limiting, please reach out to @email{guix-devel@@gnu.org}.
25805 The rest of this section documents the various services that are included by
25806 @code{ganeti-service-type}.
25808 @defvr {Scheme Variable} ganeti-noded-service-type
25809 @command{ganeti-noded} is the daemon responsible for node-specific functions
25810 within the Ganeti system. The value of this service must be a
25811 @code{ganeti-noded-configuration} object.
25814 @deftp {Data Type} ganeti-noded-configuration
25815 This is the configuration for the @code{ganeti-noded} service.
25818 @item @code{ganeti} (default: @code{ganeti})
25819 The @code{ganeti} package to use for this service.
25821 @item @code{port} (default: @code{1811})
25822 The TCP port on which the node daemon listens for network requests.
25824 @item @code{address} (default: @code{"0.0.0.0"})
25825 The network address that the daemon will bind to. The default address means
25826 bind to all available addresses.
25828 @item @code{interface} (default: @code{#f})
25829 When this is set, it must be a specific network interface (e.g.@: @code{eth0})
25830 that the daemon will bind to.
25832 @item @code{max-clients} (default: @code{20})
25833 This sets a limit on the maximum number of simultaneous client connections
25834 that the daemon will handle. Connections above this count are accepted, but
25835 no responses will be sent until enough connections have closed.
25837 @item @code{ssl?} (default: @code{#t})
25838 Whether to use SSL/TLS to encrypt network communications. The certificate
25839 is automatically provisioned by the cluster and can be rotated with
25840 @command{gnt-cluster renew-crypto}.
25842 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
25843 This can be used to provide a specific encryption key for TLS communications.
25845 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
25846 This can be used to provide a specific certificate for TLS communications.
25848 @item @code{debug?} (default: @code{#f})
25849 When true, the daemon performs additional logging for debugging purposes.
25850 Note that this will leak encryption details to the log files, use with caution.
25855 @defvr {Scheme Variable} ganeti-confd-service-type
25856 @command{ganeti-confd} answers queries related to the configuration of a
25857 Ganeti cluster. The purpose of this daemon is to have a highly available
25858 and fast way to query cluster configuration values. It is automatically
25859 active on all @dfn{master candidates}. The value of this service must be a
25860 @code{ganeti-confd-configuration} object.
25864 @deftp {Data Type} ganeti-confd-configuration
25865 This is the configuration for the @code{ganeti-confd} service.
25868 @item @code{ganeti} (default: @code{ganeti})
25869 The @code{ganeti} package to use for this service.
25871 @item @code{port} (default: @code{1814})
25872 The UDP port on which to listen for network requests.
25874 @item @code{address} (default: @code{"0.0.0.0"})
25875 Network address that the daemon will bind to.
25877 @item @code{debug?} (default: @code{#f})
25878 When true, the daemon performs additional logging for debugging purposes.
25883 @defvr {Scheme Variable} ganeti-wconfd-service-type
25884 @command{ganeti-wconfd} is the daemon that has authoritative knowledge
25885 about the cluster configuration and is the only entity that can accept
25886 changes to it. All jobs that need to modify the configuration will do so
25887 by sending appropriate requests to this daemon. It only runs on the
25888 @dfn{master node} and will automatically disable itself on other nodes.
25890 The value of this service must be a
25891 @code{ganeti-wconfd-configuration} object.
25894 @deftp {Data Type} ganeti-wconfd-configuration
25895 This is the configuration for the @code{ganeti-wconfd} service.
25898 @item @code{ganeti} (default: @code{ganeti})
25899 The @code{ganeti} package to use for this service.
25901 @item @code{no-voting?} (default: @code{#f})
25902 The daemon will refuse to start if the majority of cluster nodes does not
25903 agree that it is running on the master node. Set to @code{#t} to start
25904 even if a quorum can not be reached (dangerous, use with caution).
25906 @item @code{debug?} (default: @code{#f})
25907 When true, the daemon performs additional logging for debugging purposes.
25912 @defvr {Scheme Variable} ganeti-luxid-service-type
25913 @command{ganeti-luxid} is a daemon used to answer queries related to the
25914 configuration and the current live state of a Ganeti cluster. Additionally,
25915 it is the authoritative daemon for the Ganeti job queue. Jobs can be
25916 submitted via this daemon and it schedules and starts them.
25918 It takes a @code{ganeti-luxid-configuration} object.
25921 @deftp {Data Type} ganeti-luxid-configuration
25922 This is the configuration for the @code{ganeti-wconfd} service.
25925 @item @code{ganeti} (default: @code{ganeti})
25926 The @code{ganeti} package to use for this service.
25928 @item @code{no-voting?} (default: @code{#f})
25929 The daemon will refuse to start if it cannot verify that the majority of
25930 cluster nodes believes that it is running on the master node. Set to
25931 @code{#t} to ignore such checks and start anyway (this can be dangerous).
25933 @item @code{debug?} (default: @code{#f})
25934 When true, the daemon performs additional logging for debugging purposes.
25939 @defvr {Scheme Variable} ganeti-rapi-service-type
25940 @command{ganeti-rapi} provides a remote API for Ganeti clusters. It runs on
25941 the master node and can be used to perform cluster actions programmatically
25942 via a JSON-based RPC protocol.
25944 Most query operations are allowed without authentication (unless
25945 @var{require-authentication?} is set), whereas write operations require
25946 explicit authorization via the @file{/var/lib/ganeti/rapi/users} file. See
25947 the @url{http://docs.ganeti.org/ganeti/master/html/rapi.html, Ganeti Remote
25948 API documentation} for more information.
25950 The value of this service must be a @code{ganeti-rapi-configuration} object.
25953 @deftp {Data Type} ganeti-rapi-configuration
25954 This is the configuration for the @code{ganeti-rapi} service.
25957 @item @code{ganeti} (default: @code{ganeti})
25958 The @code{ganeti} package to use for this service.
25960 @item @code{require-authentication?} (default: @code{#f})
25961 Whether to require authentication even for read-only operations.
25963 @item @code{port} (default: @code{5080})
25964 The TCP port on which to listen to API requests.
25966 @item @code{address} (default: @code{"0.0.0.0"})
25967 The network address that the service will bind to. By default it listens
25968 on all configured addresses.
25970 @item @code{interface} (default: @code{#f})
25971 When set, it must specify a specific network interface such as @code{eth0}
25972 that the daemon will bind to.
25974 @item @code{max-clients} (default: @code{20})
25975 The maximum number of simultaneous client requests to handle. Further
25976 connections are allowed, but no responses are sent until enough connections
25979 @item @code{ssl?} (default: @code{#t})
25980 Whether to use SSL/TLS encryption on the RAPI port.
25982 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
25983 This can be used to provide a specific encryption key for TLS communications.
25985 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
25986 This can be used to provide a specific certificate for TLS communications.
25988 @item @code{debug?} (default: @code{#f})
25989 When true, the daemon performs additional logging for debugging purposes.
25990 Note that this will leak encryption details to the log files, use with caution.
25995 @defvr {Scheme Variable} ganeti-kvmd-service-type
25996 @command{ganeti-kvmd} is responsible for determining whether a given KVM
25997 instance was shut down by an administrator or a user. Normally Ganeti will
25998 restart an instance that was not stopped through Ganeti itself. If the
25999 cluster option @code{user_shutdown} is true, this daemon monitors the
26000 @code{QMP} socket provided by QEMU and listens for shutdown events, and
26001 marks the instance as @dfn{USER_down} instead of @dfn{ERROR_down} when
26002 it shuts down gracefully by itself.
26004 It takes a @code{ganeti-kvmd-configuration} object.
26007 @deftp {Data Type} ganeti-kvmd-configuration
26010 @item @code{ganeti} (default: @code{ganeti})
26011 The @code{ganeti} package to use for this service.
26013 @item @code{debug?} (default: @code{#f})
26014 When true, the daemon performs additional logging for debugging purposes.
26019 @defvr {Scheme Variable} ganeti-mond-service-type
26020 @command{ganeti-mond} is an optional daemon that provides Ganeti monitoring
26021 functionality. It is responsible for running data collectors and publish the
26022 collected information through a HTTP interface.
26024 It takes a @code{ganeti-mond-configuration} object.
26027 @deftp {Data Type} ganeti-mond-configuration
26030 @item @code{ganeti} (default: @code{ganeti})
26031 The @code{ganeti} package to use for this service.
26033 @item @code{port} (default: @code{1815})
26034 The port on which the daemon will listen.
26036 @item @code{address} (default: @code{"0.0.0.0"})
26037 The network address that the daemon will bind to. By default it binds to all
26038 available interfaces.
26040 @item @code{debug?} (default: @code{#f})
26041 When true, the daemon performs additional logging for debugging purposes.
26046 @defvr {Scheme Variable} ganeti-metad-service-type
26047 @command{ganeti-metad} is an optional daemon that can be used to provide
26048 information about the cluster to instances or OS install scripts.
26050 It takes a @code{ganeti-metad-configuration} object.
26053 @deftp {Data Type} ganeti-metad-configuration
26056 @item @code{ganeti} (default: @code{ganeti})
26057 The @code{ganeti} package to use for this service.
26059 @item @code{port} (default: @code{80})
26060 The port on which the daemon will listen.
26062 @item @code{address} (default: @code{#f})
26063 If set, the daemon will bind to this address only. If left unset, the behavior
26064 depends on the cluster configuration.
26066 @item @code{debug?} (default: @code{#f})
26067 When true, the daemon performs additional logging for debugging purposes.
26072 @defvr {Scheme Variable} ganeti-watcher-service-type
26073 @command{ganeti-watcher} is a script designed to run periodically and ensure
26074 the health of a cluster. It will automatically restart instances that have
26075 stopped without Ganetis consent, and repairs DRBD links in case a node has
26076 rebooted. It also archives old cluster jobs and restarts Ganeti daemons
26077 that are not running. If the cluster parameter @code{ensure_node_health}
26078 is set, the watcher will also shutdown instances and DRBD devices if the
26079 node it is running on is declared offline by known master candidates.
26081 It can be paused on all nodes with @command{gnt-cluster watcher pause}.
26083 The service takes a @code{ganeti-watcher-configuration} object.
26086 @deftp {Data Type} ganeti-watcher-configuration
26089 @item @code{ganeti} (default: @code{ganeti})
26090 The @code{ganeti} package to use for this service.
26092 @item @code{schedule} (default: @code{'(next-second-from (next-minute (range 0 60 5)))})
26093 How often to run the script. The default is every five minutes.
26095 @item @code{rapi-ip} (default: @code{#f})
26096 This option needs to be specified only if the RAPI daemon is configured to use
26097 a particular interface or address. By default the cluster address is used.
26099 @item @code{job-age} (default: @code{(* 6 3600)})
26100 Archive cluster jobs older than this age, specified in seconds. The default
26101 is 6 hours. This keeps @command{gnt-job list} manageable.
26103 @item @code{verify-disks?} (default: @code{#t})
26104 If this is @code{#f}, the watcher will not try to repair broken DRBD links
26105 automatically. Administrators will need to use @command{gnt-cluster verify-disks}
26108 @item @code{debug?} (default: @code{#f})
26109 When @code{#t}, the script performs additional logging for debugging purposes.
26114 @defvr {Scheme Variable} ganeti-cleaner-service-type
26115 @command{ganeti-cleaner} is a script designed to run periodically and remove
26116 old files from the cluster. This service type controls two @dfn{cron jobs}:
26117 one intended for the master node that permanently purges old cluster jobs,
26118 and one intended for every node that removes expired X509 certificates, keys,
26119 and outdated @command{ganeti-watcher} information. Like all Ganeti services,
26120 it is safe to include even on non-master nodes as it will disable itself as
26123 It takes a @code{ganeti-cleaner-configuration} object.
26126 @deftp {Data Type} ganeti-cleaner-configuration
26129 @item @code{ganeti} (default: @code{ganeti})
26130 The @code{ganeti} package to use for the @command{gnt-cleaner} command.
26132 @item @code{master-schedule} (default: @code{"45 1 * * *"})
26133 How often to run the master cleaning job. The default is once per day, at
26136 @item @code{node-schedule} (default: @code{"45 2 * * *"})
26137 How often to run the node cleaning job. The default is once per day, at
26143 @node Version Control Services
26144 @subsection Version Control Services
26146 The @code{(gnu services version-control)} module provides a service to
26147 allow remote access to local Git repositories. There are three options:
26148 the @code{git-daemon-service}, which provides access to repositories via
26149 the @code{git://} unsecured TCP-based protocol, extending the
26150 @code{nginx} web server to proxy some requests to
26151 @code{git-http-backend}, or providing a web interface with
26152 @code{cgit-service-type}.
26154 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
26156 Return a service that runs @command{git daemon}, a simple TCP server to
26157 expose repositories over the Git protocol for anonymous access.
26159 The optional @var{config} argument should be a
26160 @code{<git-daemon-configuration>} object, by default it allows read-only
26161 access to exported@footnote{By creating the magic file
26162 @file{git-daemon-export-ok} in the repository directory.} repositories under
26167 @deftp {Data Type} git-daemon-configuration
26168 Data type representing the configuration for @code{git-daemon-service}.
26171 @item @code{package} (default: @code{git})
26172 Package object of the Git distributed version control system.
26174 @item @code{export-all?} (default: @code{#f})
26175 Whether to allow access for all Git repositories, even if they do not
26176 have the @file{git-daemon-export-ok} file.
26178 @item @code{base-path} (default: @file{/srv/git})
26179 Whether to remap all the path requests as relative to the given path.
26180 If you run @command{git daemon} with @code{(base-path "/srv/git")} on
26181 @samp{example.com}, then if you later try to pull
26182 @indicateurl{git://example.com/hello.git}, git daemon will interpret the
26183 path as @file{/srv/git/hello.git}.
26185 @item @code{user-path} (default: @code{#f})
26186 Whether to allow @code{~user} notation to be used in requests. When
26187 specified with empty string, requests to
26188 @indicateurl{git://host/~alice/foo} is taken as a request to access
26189 @code{foo} repository in the home directory of user @code{alice}. If
26190 @code{(user-path "@var{path}")} is specified, the same request is taken
26191 as a request to access @file{@var{path}/foo} repository in the home
26192 directory of user @code{alice}.
26194 @item @code{listen} (default: @code{'()})
26195 Whether to listen on specific IP addresses or hostnames, defaults to
26198 @item @code{port} (default: @code{#f})
26199 Whether to listen on an alternative port, which defaults to 9418.
26201 @item @code{whitelist} (default: @code{'()})
26202 If not empty, only allow access to this list of directories.
26204 @item @code{extra-options} (default: @code{'()})
26205 Extra options will be passed to @command{git daemon}, please run
26206 @command{man git-daemon} for more information.
26211 The @code{git://} protocol lacks authentication. When you pull from a
26212 repository fetched via @code{git://}, you don't know whether the data you
26213 receive was modified or is even coming from the specified host, and your
26214 connection is subject to eavesdropping. It's better to use an authenticated
26215 and encrypted transport, such as @code{https}. Although Git allows you
26216 to serve repositories using unsophisticated file-based web servers,
26217 there is a faster protocol implemented by the @code{git-http-backend}
26218 program. This program is the back-end of a proper Git web service. It
26219 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
26220 on running the necessary @code{fcgiwrap} daemon.
26222 Guix has a separate configuration data type for serving Git repositories
26225 @deftp {Data Type} git-http-configuration
26226 Data type representing the configuration for a future
26227 @code{git-http-service-type}; can currently be used to configure Nginx
26228 trough @code{git-http-nginx-location-configuration}.
26231 @item @code{package} (default: @var{git})
26232 Package object of the Git distributed version control system.
26234 @item @code{git-root} (default: @file{/srv/git})
26235 Directory containing the Git repositories to expose to the world.
26237 @item @code{export-all?} (default: @code{#f})
26238 Whether to expose access for all Git repositories in @var{git-root},
26239 even if they do not have the @file{git-daemon-export-ok} file.
26241 @item @code{uri-path} (default: @samp{/git/})
26242 Path prefix for Git access. With the default @samp{/git/} prefix, this
26243 will map @indicateurl{http://@var{server}/git/@var{repo}.git} to
26244 @file{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
26245 with this prefix are not passed on to this Git instance.
26247 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
26248 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
26253 There is no @code{git-http-service-type}, currently; instead you can
26254 create an @code{nginx-location-configuration} from a
26255 @code{git-http-configuration} and then add that location to a web
26258 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
26259 [config=(git-http-configuration)]
26260 Compute an @code{nginx-location-configuration} that corresponds to the
26261 given Git http configuration. An example nginx service definition to
26262 serve the default @file{/srv/git} over HTTPS might be:
26265 (service nginx-service-type
26266 (nginx-configuration
26269 (nginx-server-configuration
26270 (listen '("443 ssl"))
26271 (server-name "git.my-host.org")
26273 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
26274 (ssl-certificate-key
26275 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
26278 (git-http-nginx-location-configuration
26279 (git-http-configuration (uri-path "/"))))))))))
26282 This example assumes that you are using Let's Encrypt to get your TLS
26283 certificate. @xref{Certificate Services}. The default @code{certbot}
26284 service will redirect all HTTP traffic on @code{git.my-host.org} to
26285 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
26286 system services. @xref{Web Services}.
26289 @subsubheading Cgit Service
26291 @cindex Cgit service
26292 @cindex Git, web interface
26293 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
26294 repositories written in C.
26296 The following example will configure the service with default values.
26297 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
26300 (service cgit-service-type)
26303 The @code{file-object} type designates either a file-like object
26304 (@pxref{G-Expressions, file-like objects}) or a string.
26306 @c %start of fragment
26308 Available @code{cgit-configuration} fields are:
26310 @deftypevr {@code{cgit-configuration} parameter} package package
26315 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
26316 NGINX configuration.
26320 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
26321 Specifies a command which will be invoked to format the content of about
26322 pages (both top-level and for each repository).
26324 Defaults to @samp{""}.
26328 @deftypevr {@code{cgit-configuration} parameter} string agefile
26329 Specifies a path, relative to each repository path, which can be used to
26330 specify the date and time of the youngest commit in the repository.
26332 Defaults to @samp{""}.
26336 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
26337 Specifies a command that will be invoked for authenticating repository
26340 Defaults to @samp{""}.
26344 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
26345 Flag which, when set to @samp{age}, enables date ordering in the branch
26346 ref list, and when set @samp{name} enables ordering by branch name.
26348 Defaults to @samp{"name"}.
26352 @deftypevr {@code{cgit-configuration} parameter} string cache-root
26353 Path used to store the cgit cache entries.
26355 Defaults to @samp{"/var/cache/cgit"}.
26359 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
26360 Number which specifies the time-to-live, in minutes, for the cached
26361 version of repository pages accessed with a fixed SHA1.
26363 Defaults to @samp{-1}.
26367 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
26368 Number which specifies the time-to-live, in minutes, for the cached
26369 version of repository pages accessed without a fixed SHA1.
26371 Defaults to @samp{5}.
26375 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
26376 Number which specifies the time-to-live, in minutes, for the cached
26377 version of the repository summary page.
26379 Defaults to @samp{5}.
26383 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
26384 Number which specifies the time-to-live, in minutes, for the cached
26385 version of the repository index page.
26387 Defaults to @samp{5}.
26391 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
26392 Number which specifies the time-to-live, in minutes, for the result of
26393 scanning a path for Git repositories.
26395 Defaults to @samp{15}.
26399 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
26400 Number which specifies the time-to-live, in minutes, for the cached
26401 version of the repository about page.
26403 Defaults to @samp{15}.
26407 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
26408 Number which specifies the time-to-live, in minutes, for the cached
26409 version of snapshots.
26411 Defaults to @samp{5}.
26415 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
26416 The maximum number of entries in the cgit cache. When set to @samp{0},
26417 caching is disabled.
26419 Defaults to @samp{0}.
26423 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
26424 Sort items in the repo list case sensitively.
26426 Defaults to @samp{#t}.
26430 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
26431 List of common prefixes which, when combined with a repository URL,
26432 generates valid clone URLs for the repository.
26434 Defaults to @samp{()}.
26438 @deftypevr {@code{cgit-configuration} parameter} list clone-url
26439 List of @code{clone-url} templates.
26441 Defaults to @samp{()}.
26445 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
26446 Command which will be invoked to format commit messages.
26448 Defaults to @samp{""}.
26452 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
26453 Flag which, when set to @samp{date}, enables strict date ordering in the
26454 commit log, and when set to @samp{topo} enables strict topological
26457 Defaults to @samp{"git log"}.
26461 @deftypevr {@code{cgit-configuration} parameter} file-object css
26462 URL which specifies the css document to include in all cgit pages.
26464 Defaults to @samp{"/share/cgit/cgit.css"}.
26468 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
26469 Specifies a command which will be invoked to format names and email
26470 address of committers, authors, and taggers, as represented in various
26471 places throughout the cgit interface.
26473 Defaults to @samp{""}.
26477 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
26478 Flag which, when set to @samp{#t}, will make cgit generate a HTML
26479 fragment suitable for embedding in other HTML pages.
26481 Defaults to @samp{#f}.
26485 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
26486 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
26487 commit history graph to the left of the commit messages in the
26488 repository log page.
26490 Defaults to @samp{#f}.
26494 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
26495 Flag which, when set to @samp{#t}, allows all filter settings to be
26496 overridden in repository-specific cgitrc files.
26498 Defaults to @samp{#f}.
26502 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
26503 Flag which, when set to @samp{#t}, allows users to follow a file in the
26506 Defaults to @samp{#f}.
26510 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
26511 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
26514 Defaults to @samp{#t}.
26518 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
26519 Flag which, when set to @samp{#t}, will make cgit generate extra links
26520 "summary", "commit", "tree" for each repo in the repository index.
26522 Defaults to @samp{#f}.
26526 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
26527 Flag which, when set to @samp{#t}, will make cgit display the owner of
26528 each repo in the repository index.
26530 Defaults to @samp{#t}.
26534 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
26535 Flag which, when set to @samp{#t}, will make cgit print the number of
26536 modified files for each commit on the repository log page.
26538 Defaults to @samp{#f}.
26542 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
26543 Flag which, when set to @samp{#t}, will make cgit print the number of
26544 added and removed lines for each commit on the repository log page.
26546 Defaults to @samp{#f}.
26550 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
26551 Flag which, when set to @code{#t}, will make cgit display remote
26552 branches in the summary and refs views.
26554 Defaults to @samp{#f}.
26558 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
26559 Flag which, when set to @code{1}, will make cgit use the subject of the
26560 parent commit as link text when generating links to parent commits in
26563 Defaults to @samp{#f}.
26567 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
26568 Flag which, when set to @samp{#t}, will make cgit use the subject of the
26569 parent commit as link text when generating links to parent commits in
26572 Defaults to @samp{#f}.
26576 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
26577 Flag which, when set to @samp{#t}, will make cgit generate linenumber
26578 links for plaintext blobs printed in the tree view.
26580 Defaults to @samp{#t}.
26584 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
26585 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
26586 set any repo specific settings.
26588 Defaults to @samp{#f}.
26592 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
26593 URL used as link to a shortcut icon for cgit.
26595 Defaults to @samp{"/favicon.ico"}.
26599 @deftypevr {@code{cgit-configuration} parameter} string footer
26600 The content of the file specified with this option will be included
26601 verbatim at the bottom of all pages (i.e.@: it replaces the standard
26602 "generated by..."@: message).
26604 Defaults to @samp{""}.
26608 @deftypevr {@code{cgit-configuration} parameter} string head-include
26609 The content of the file specified with this option will be included
26610 verbatim in the HTML HEAD section on all pages.
26612 Defaults to @samp{""}.
26616 @deftypevr {@code{cgit-configuration} parameter} string header
26617 The content of the file specified with this option will be included
26618 verbatim at the top of all pages.
26620 Defaults to @samp{""}.
26624 @deftypevr {@code{cgit-configuration} parameter} file-object include
26625 Name of a configfile to include before the rest of the current config-
26628 Defaults to @samp{""}.
26632 @deftypevr {@code{cgit-configuration} parameter} string index-header
26633 The content of the file specified with this option will be included
26634 verbatim above the repository index.
26636 Defaults to @samp{""}.
26640 @deftypevr {@code{cgit-configuration} parameter} string index-info
26641 The content of the file specified with this option will be included
26642 verbatim below the heading on the repository index page.
26644 Defaults to @samp{""}.
26648 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
26649 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
26650 in the servers timezone.
26652 Defaults to @samp{#f}.
26656 @deftypevr {@code{cgit-configuration} parameter} file-object logo
26657 URL which specifies the source of an image which will be used as a logo
26660 Defaults to @samp{"/share/cgit/cgit.png"}.
26664 @deftypevr {@code{cgit-configuration} parameter} string logo-link
26665 URL loaded when clicking on the cgit logo image.
26667 Defaults to @samp{""}.
26671 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
26672 Command which will be invoked to format the Owner column of the main
26675 Defaults to @samp{""}.
26679 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
26680 Number of items to display in atom feeds view.
26682 Defaults to @samp{10}.
26686 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
26687 Number of entries to list per page in "log" view.
26689 Defaults to @samp{50}.
26693 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
26694 Number of commit message characters to display in "log" view.
26696 Defaults to @samp{80}.
26700 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
26701 Specifies the number of entries to list per page on the repository index
26704 Defaults to @samp{50}.
26708 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
26709 Specifies the maximum number of repo description characters to display
26710 on the repository index page.
26712 Defaults to @samp{80}.
26716 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
26717 Specifies the maximum size of a blob to display HTML for in KBytes.
26719 Defaults to @samp{0}.
26723 @deftypevr {@code{cgit-configuration} parameter} string max-stats
26724 Maximum statistics period. Valid values are @samp{week},@samp{month},
26725 @samp{quarter} and @samp{year}.
26727 Defaults to @samp{""}.
26731 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
26732 Mimetype for the specified filename extension.
26734 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
26735 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
26736 "image/png") (svg "image/svg+xml"))}.
26740 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
26741 Specifies the file to use for automatic mimetype lookup.
26743 Defaults to @samp{""}.
26747 @deftypevr {@code{cgit-configuration} parameter} string module-link
26748 Text which will be used as the formatstring for a hyperlink when a
26749 submodule is printed in a directory listing.
26751 Defaults to @samp{""}.
26755 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
26756 If set to the value @samp{#t} caching will be disabled.
26758 Defaults to @samp{#f}.
26762 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
26763 If set to @samp{#t} showing full author email addresses will be
26766 Defaults to @samp{#f}.
26770 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
26771 Flag which, when set to @samp{#t}, will make cgit omit the standard
26772 header on all pages.
26774 Defaults to @samp{#f}.
26778 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
26779 A list of subdirectories inside of @code{repository-directory}, relative
26780 to it, that should loaded as Git repositories. An empty list means that
26781 all subdirectories will be loaded.
26783 Defaults to @samp{()}.
26787 @deftypevr {@code{cgit-configuration} parameter} file-object readme
26788 Text which will be used as default value for @code{cgit-repo-readme}.
26790 Defaults to @samp{""}.
26794 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
26795 If set to @code{#t} and @code{repository-directory} is enabled, if any
26796 repositories are found with a suffix of @code{.git}, this suffix will be
26797 removed for the URL and name.
26799 Defaults to @samp{#f}.
26803 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
26804 Maximum number of files to consider when detecting renames.
26806 Defaults to @samp{-1}.
26810 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
26811 The way in which repositories in each section are sorted.
26813 Defaults to @samp{""}.
26817 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
26818 Text used as content for the @code{robots} meta-tag.
26820 Defaults to @samp{("noindex" "nofollow")}.
26824 @deftypevr {@code{cgit-configuration} parameter} string root-desc
26825 Text printed below the heading on the repository index page.
26827 Defaults to @samp{"a fast webinterface for the git dscm"}.
26831 @deftypevr {@code{cgit-configuration} parameter} string root-readme
26832 The content of the file specified with this option will be included
26833 verbatim below the ``about'' link on the repository index page.
26835 Defaults to @samp{""}.
26839 @deftypevr {@code{cgit-configuration} parameter} string root-title
26840 Text printed as heading on the repository index page.
26842 Defaults to @samp{""}.
26846 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
26847 If set to @samp{#t} and repository-directory is enabled,
26848 repository-directory will recurse into directories whose name starts
26849 with a period. Otherwise, repository-directory will stay away from such
26850 directories, considered as ``hidden''. Note that this does not apply to
26851 the @file{.git} directory in non-bare repos.
26853 Defaults to @samp{#f}.
26857 @deftypevr {@code{cgit-configuration} parameter} list snapshots
26858 Text which specifies the default set of snapshot formats that cgit
26859 generates links for.
26861 Defaults to @samp{()}.
26865 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
26866 Name of the directory to scan for repositories (represents
26869 Defaults to @samp{"/srv/git"}.
26873 @deftypevr {@code{cgit-configuration} parameter} string section
26874 The name of the current repository section - all repositories defined
26875 after this option will inherit the current section name.
26877 Defaults to @samp{""}.
26881 @deftypevr {@code{cgit-configuration} parameter} string section-sort
26882 Flag which, when set to @samp{1}, will sort the sections on the
26883 repository listing by name.
26885 Defaults to @samp{""}.
26889 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
26890 A number which, if defined prior to repository-directory, specifies how
26891 many path elements from each repo path to use as a default section name.
26893 Defaults to @samp{0}.
26897 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
26898 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
26901 Defaults to @samp{#f}.
26905 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
26906 Specifies a command which will be invoked to format plaintext blobs in
26909 Defaults to @samp{""}.
26913 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
26914 Specifies the number of branches to display in the repository ``summary''
26917 Defaults to @samp{10}.
26921 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
26922 Specifies the number of log entries to display in the repository
26925 Defaults to @samp{10}.
26929 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
26930 Specifies the number of tags to display in the repository ``summary''
26933 Defaults to @samp{10}.
26937 @deftypevr {@code{cgit-configuration} parameter} string strict-export
26938 Filename which, if specified, needs to be present within the repository
26939 for cgit to allow access to that repository.
26941 Defaults to @samp{""}.
26945 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
26946 URL which, if specified, will be used as root for all cgit links.
26948 Defaults to @samp{"/"}.
26952 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
26953 A list of @dfn{cgit-repo} records to use with config.
26955 Defaults to @samp{()}.
26957 Available @code{repository-cgit-configuration} fields are:
26959 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
26960 A mask of snapshot formats for this repo that cgit generates links for,
26961 restricted by the global @code{snapshots} setting.
26963 Defaults to @samp{()}.
26967 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
26968 Override the default @code{source-filter}.
26970 Defaults to @samp{""}.
26974 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
26975 The relative URL used to access the repository.
26977 Defaults to @samp{""}.
26981 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
26982 Override the default @code{about-filter}.
26984 Defaults to @samp{""}.
26988 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
26989 Flag which, when set to @samp{age}, enables date ordering in the branch
26990 ref list, and when set to @samp{name} enables ordering by branch name.
26992 Defaults to @samp{""}.
26996 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
26997 A list of URLs which can be used to clone repo.
26999 Defaults to @samp{()}.
27003 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
27004 Override the default @code{commit-filter}.
27006 Defaults to @samp{""}.
27010 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
27011 Flag which, when set to @samp{date}, enables strict date ordering in the
27012 commit log, and when set to @samp{topo} enables strict topological
27015 Defaults to @samp{""}.
27019 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
27020 The name of the default branch for this repository. If no such branch
27021 exists in the repository, the first branch name (when sorted) is used as
27022 default instead. By default branch pointed to by HEAD, or ``master'' if
27023 there is no suitable HEAD.
27025 Defaults to @samp{""}.
27029 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
27030 The value to show as repository description.
27032 Defaults to @samp{""}.
27036 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
27037 The value to show as repository homepage.
27039 Defaults to @samp{""}.
27043 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
27044 Override the default @code{email-filter}.
27046 Defaults to @samp{""}.
27050 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
27051 A flag which can be used to disable the global setting
27052 @code{enable-commit-graph?}.
27054 Defaults to @samp{disabled}.
27058 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
27059 A flag which can be used to disable the global setting
27060 @code{enable-log-filecount?}.
27062 Defaults to @samp{disabled}.
27066 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
27067 A flag which can be used to disable the global setting
27068 @code{enable-log-linecount?}.
27070 Defaults to @samp{disabled}.
27074 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
27075 Flag which, when set to @code{#t}, will make cgit display remote
27076 branches in the summary and refs views.
27078 Defaults to @samp{disabled}.
27082 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
27083 A flag which can be used to override the global setting
27084 @code{enable-subject-links?}.
27086 Defaults to @samp{disabled}.
27090 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
27091 A flag which can be used to override the global setting
27092 @code{enable-html-serving?}.
27094 Defaults to @samp{disabled}.
27098 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
27099 Flag which, when set to @code{#t}, hides the repository from the
27102 Defaults to @samp{#f}.
27106 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
27107 Flag which, when set to @samp{#t}, ignores the repository.
27109 Defaults to @samp{#f}.
27113 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
27114 URL which specifies the source of an image which will be used as a logo
27115 on this repo’s pages.
27117 Defaults to @samp{""}.
27121 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
27122 URL loaded when clicking on the cgit logo image.
27124 Defaults to @samp{""}.
27128 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
27129 Override the default @code{owner-filter}.
27131 Defaults to @samp{""}.
27135 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
27136 Text which will be used as the formatstring for a hyperlink when a
27137 submodule is printed in a directory listing. The arguments for the
27138 formatstring are the path and SHA1 of the submodule commit.
27140 Defaults to @samp{""}.
27144 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
27145 Text which will be used as the formatstring for a hyperlink when a
27146 submodule with the specified subdirectory path is printed in a directory
27149 Defaults to @samp{()}.
27153 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
27154 Override the default maximum statistics period.
27156 Defaults to @samp{""}.
27160 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
27161 The value to show as repository name.
27163 Defaults to @samp{""}.
27167 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
27168 A value used to identify the owner of the repository.
27170 Defaults to @samp{""}.
27174 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
27175 An absolute path to the repository directory.
27177 Defaults to @samp{""}.
27181 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
27182 A path (relative to repo) which specifies a file to include verbatim as
27183 the ``About'' page for this repo.
27185 Defaults to @samp{""}.
27189 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
27190 The name of the current repository section - all repositories defined
27191 after this option will inherit the current section name.
27193 Defaults to @samp{""}.
27197 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
27198 Extra options will be appended to cgitrc file.
27200 Defaults to @samp{()}.
27206 @deftypevr {@code{cgit-configuration} parameter} list extra-options
27207 Extra options will be appended to cgitrc file.
27209 Defaults to @samp{()}.
27214 @c %end of fragment
27216 However, it could be that you just want to get a @code{cgitrc} up and
27217 running. In that case, you can pass an @code{opaque-cgit-configuration}
27218 as a record to @code{cgit-service-type}. As its name indicates, an
27219 opaque configuration does not have easy reflective capabilities.
27221 Available @code{opaque-cgit-configuration} fields are:
27223 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
27227 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
27228 The contents of the @code{cgitrc}, as a string.
27231 For example, if your @code{cgitrc} is just the empty string, you
27232 could instantiate a cgit service like this:
27235 (service cgit-service-type
27236 (opaque-cgit-configuration
27240 @subsubheading Gitolite Service
27242 @cindex Gitolite service
27243 @cindex Git, hosting
27244 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
27245 repositories on a central server.
27247 Gitolite can handle multiple repositories and users, and supports flexible
27248 configuration of the permissions for the users on the repositories.
27250 The following example will configure Gitolite using the default @code{git}
27251 user, and the provided SSH public key.
27254 (service gitolite-service-type
27255 (gitolite-configuration
27256 (admin-pubkey (plain-file
27258 "ssh-rsa AAAA... guix@@example.com"))))
27261 Gitolite is configured through a special admin repository which you can clone,
27262 for example, if you setup Gitolite on @code{example.com}, you would run the
27263 following command to clone the admin repository.
27266 git clone git@@example.com:gitolite-admin
27269 When the Gitolite service is activated, the provided @code{admin-pubkey} will
27270 be inserted in to the @file{keydir} directory in the gitolite-admin
27271 repository. If this results in a change in the repository, it will be
27272 committed using the message ``gitolite setup by GNU Guix''.
27274 @deftp {Data Type} gitolite-configuration
27275 Data type representing the configuration for @code{gitolite-service-type}.
27278 @item @code{package} (default: @var{gitolite})
27279 Gitolite package to use.
27281 @item @code{user} (default: @var{git})
27282 User to use for Gitolite. This will be user that you use when accessing
27285 @item @code{group} (default: @var{git})
27286 Group to use for Gitolite.
27288 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
27289 Directory in which to store the Gitolite configuration and repositories.
27291 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
27292 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
27293 representing the configuration for Gitolite.
27295 @item @code{admin-pubkey} (default: @var{#f})
27296 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
27297 setup Gitolite. This will be inserted in to the @file{keydir} directory
27298 within the gitolite-admin repository.
27300 To specify the SSH key as a string, use the @code{plain-file} function.
27303 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
27309 @deftp {Data Type} gitolite-rc-file
27310 Data type representing the Gitolite RC file.
27313 @item @code{umask} (default: @code{#o0077})
27314 This controls the permissions Gitolite sets on the repositories and their
27317 A value like @code{#o0027} will give read access to the group used by Gitolite
27318 (by default: @code{git}). This is necessary when using Gitolite with software
27319 like cgit or gitweb.
27321 @item @code{git-config-keys} (default: @code{""})
27322 Gitolite allows you to set git config values using the @samp{config} keyword. This
27323 setting allows control over the config keys to accept.
27325 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
27326 Set the role names allowed to be used by users running the perms command.
27328 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
27329 This setting controls the commands and features to enable within Gitolite.
27335 @node Game Services
27336 @subsection Game Services
27338 @subsubheading The Battle for Wesnoth Service
27340 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
27341 based tactical strategy game, with several single player campaigns, and
27342 multiplayer games (both networked and local).
27344 @defvar {Scheme Variable} wesnothd-service-type
27345 Service type for the wesnothd service. Its value must be a
27346 @code{wesnothd-configuration} object. To run wesnothd in the default
27347 configuration, instantiate it as:
27350 (service wesnothd-service-type)
27354 @deftp {Data Type} wesnothd-configuration
27355 Data type representing the configuration of @command{wesnothd}.
27358 @item @code{package} (default: @code{wesnoth-server})
27359 The wesnoth server package to use.
27361 @item @code{port} (default: @code{15000})
27362 The port to bind the server to.
27367 @node PAM Mount Service
27368 @subsection PAM Mount Service
27371 The @code{(gnu services pam-mount)} module provides a service allowing
27372 users to mount volumes when they log in. It should be able to mount any
27373 volume format supported by the system.
27375 @defvar {Scheme Variable} pam-mount-service-type
27376 Service type for PAM Mount support.
27379 @deftp {Data Type} pam-mount-configuration
27380 Data type representing the configuration of PAM Mount.
27382 It takes the following parameters:
27386 The configuration rules that will be used to generate
27387 @file{/etc/security/pam_mount.conf.xml}.
27389 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
27390 Guile Reference Manual}), and the the default ones don't mount anything
27391 for anyone at login:
27394 `((debug (@@ (enable "0")))
27395 (mntoptions (@@ (allow ,(string-join
27396 '("nosuid" "nodev" "loop"
27397 "encryption" "fsck" "nonempty"
27398 "allow_root" "allow_other")
27400 (mntoptions (@@ (require "nosuid,nodev")))
27401 (logout (@@ (wait "0")
27405 (mkmountpoint (@@ (enable "1")
27409 Some @code{volume} elements must be added to automatically mount volumes
27410 at login. Here's an example allowing the user @code{alice} to mount her
27411 encrypted @env{HOME} directory and allowing the user @code{bob} to mount
27412 the partition where he stores his data:
27415 (define pam-mount-rules
27416 `((debug (@@ (enable "0")))
27417 (volume (@@ (user "alice")
27420 (mountpoint "/home/alice")))
27421 (volume (@@ (user "bob")
27424 (mountpoint "/home/bob/data")
27425 (options "defaults,autodefrag,compress")))
27426 (mntoptions (@@ (allow ,(string-join
27427 '("nosuid" "nodev" "loop"
27428 "encryption" "fsck" "nonempty"
27429 "allow_root" "allow_other")
27431 (mntoptions (@@ (require "nosuid,nodev")))
27432 (logout (@@ (wait "0")
27436 (mkmountpoint (@@ (enable "1")
27437 (remove "true")))))
27439 (service pam-mount-service-type
27440 (pam-mount-configuration
27441 (rules pam-mount-rules)))
27444 The complete list of possible options can be found in the man page for
27445 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
27450 @node Guix Services
27451 @subsection Guix Services
27453 @subsubheading Guix Data Service
27454 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
27455 and provides data about GNU Guix. This includes information about
27456 packages, derivations and lint warnings.
27458 The data is stored in a PostgreSQL database, and available through a web
27461 @defvar {Scheme Variable} guix-data-service-type
27462 Service type for the Guix Data Service. Its value must be a
27463 @code{guix-data-service-configuration} object. The service optionally
27464 extends the getmail service, as the guix-commits mailing list is used to
27465 find out about changes in the Guix git repository.
27468 @deftp {Data Type} guix-data-service-configuration
27469 Data type representing the configuration of the Guix Data Service.
27472 @item @code{package} (default: @code{guix-data-service})
27473 The Guix Data Service package to use.
27475 @item @code{user} (default: @code{"guix-data-service"})
27476 The system user to run the service as.
27478 @item @code{group} (default: @code{"guix-data-service"})
27479 The system group to run the service as.
27481 @item @code{port} (default: @code{8765})
27482 The port to bind the web service to.
27484 @item @code{host} (default: @code{"127.0.0.1"})
27485 The host to bind the web service to.
27487 @item @code{getmail-idle-mailboxes} (default: @code{#f})
27488 If set, this is the list of mailboxes that the getmail service will be
27489 configured to listen to.
27491 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
27492 If set, this is the @code{getmail-retriever-configuration} object with
27493 which to configure getmail to fetch mail from the guix-commits mailing
27496 @item @code{extra-options} (default: @var{'()})
27497 Extra command line options for @code{guix-data-service}.
27499 @item @code{extra-process-jobs-options} (default: @var{'()})
27500 Extra command line options for @code{guix-data-service-process-jobs}.
27505 @node Linux Services
27506 @subsection Linux Services
27509 @cindex out of memory killer
27511 @cindex early out of memory daemon
27512 @subsubheading Early OOM Service
27514 @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
27515 Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
27516 space and provides a more responsive and configurable alternative to the
27517 in-kernel OOM killer. It is useful to prevent the system from becoming
27518 unresponsive when it runs out of memory.
27520 @deffn {Scheme Variable} earlyoom-service-type
27521 The service type for running @command{earlyoom}, the Early OOM daemon.
27522 Its value must be a @code{earlyoom-configuration} object, described
27523 below. The service can be instantiated in its default configuration
27527 (service earlyoom-service-type)
27531 @deftp {Data Type} earlyoom-configuration
27532 This is the configuration record for the @code{earlyoom-service-type}.
27535 @item @code{earlyoom} (default: @var{earlyoom})
27536 The Earlyoom package to use.
27538 @item @code{minimum-available-memory} (default: @code{10})
27539 The threshold for the minimum @emph{available} memory, in percentages.
27541 @item @code{minimum-free-swap} (default: @code{10})
27542 The threshold for the minimum free swap memory, in percentages.
27544 @item @code{prefer-regexp} (default: @code{#f})
27545 A regular expression (as a string) to match the names of the processes
27546 that should be preferably killed.
27548 @item @code{avoid-regexp} (default: @code{#f})
27549 A regular expression (as a string) to match the names of the processes
27550 that should @emph{not} be killed.
27552 @item @code{memory-report-interval} (default: @code{0})
27553 The interval in seconds at which a memory report is printed. It is
27554 disabled by default.
27556 @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
27557 A boolean indicating whether the positive adjustments set in
27558 @file{/proc/*/oom_score_adj}.
27560 @item @code{show-debug-messages?} (default: @code{#f})
27561 A boolean indicating whether debug messages should be printed. The logs
27562 are saved at @file{/var/log/earlyoom.log}.
27564 @item @code{send-notification-command} (default: @code{#f})
27565 This can be used to provide a custom command used for sending
27571 @cindex kernel module loader
27572 @subsubheading Kernel Module Loader Service
27574 The kernel module loader service allows one to load loadable kernel
27575 modules at boot. This is especially useful for modules that don't
27576 autoload and need to be manually loaded, as it's the case with
27579 @deffn {Scheme Variable} kernel-module-loader-service-type
27580 The service type for loading loadable kernel modules at boot with
27581 @command{modprobe}. Its value must be a list of strings representing
27582 module names. For example loading the drivers provided by
27583 @code{ddcci-driver-linux}, in debugging mode by passing some module
27584 parameters, can be done as follow:
27587 (use-modules (gnu) (gnu services))
27588 (use-package-modules linux)
27589 (use-service-modules linux)
27591 (define ddcci-config
27592 (plain-file "ddcci.conf"
27593 "options ddcci dyndbg delay=120"))
27597 (services (cons* (service kernel-module-loader-service-type
27598 '("ddcci" "ddcci_backlight"))
27599 (simple-service 'ddcci-config etc-service-type
27600 (list `("modprobe.d/ddcci.conf"
27603 (kernel-loadable-modules (list ddcci-driver-linux)))
27608 @cindex compressed swap
27609 @cindex Compressed RAM-based block devices
27610 @subsubheading Zram Device Service
27612 The Zram device service provides a compressed swap device in system
27613 memory. The Linux Kernel documentation has more information about
27614 @uref{https://www.kernel.org/doc/html/latest/admin-guide/blockdev/zram.html,zram}
27617 @deffn {Scheme Variable} zram-device-service-type
27618 This service creates the zram block device, formats it as swap and
27619 enables it as a swap device. The service's value is a
27620 @code{zram-device-configuration} record.
27622 @deftp {Data Type} zram-device-configuration
27623 This is the data type representing the configuration for the zram-device
27627 @item @code{size} (default @var{"1G"})
27628 This is the amount of space you wish to provide for the zram device. It
27629 accepts a string and can be a number of bytes or use a suffix, eg.:
27630 @var{"512M"} or @var{1024000}.
27631 @item @code{compression-algorithm} (default @var{'lzo})
27632 This is the compression algorithm you wish to use. It is difficult to
27633 list all the possible compression options, but common ones supported by
27634 Guix's Linux Libre Kernel include @var{'lzo}, @var{'lz4} and @var{'zstd}.
27635 @item @code{memory-limit} (default @var{0})
27636 This is the maximum amount of memory which the zram device can use.
27637 Setting it to '0' disables the limit. While it is generally expected
27638 that compression will be 2:1, it is possible that uncompressable data
27639 can be written to swap and this is a method to limit how much memory can
27640 be used. It accepts a string and can be a number of bytes or use a
27641 suffix, eg.: @var{"2G"}.
27642 @item @code{priority} (default @var{-1})
27643 This is the priority of the swap device created from the zram device.
27644 @code{swapon} accepts values between -1 and 32767, with higher values
27645 indicating higher priority. Higher priority swap will generally be used
27652 @node Hurd Services
27653 @subsection Hurd Services
27655 @defvr {Scheme Variable} hurd-console-service-type
27656 This service starts the fancy @code{VGA} console client on the Hurd.
27658 The service's value is a @code{hurd-console-configuration} record.
27661 @deftp {Data Type} hurd-console-configuration
27662 This is the data type representing the configuration for the
27663 hurd-console-service.
27666 @item @code{hurd} (default: @var{hurd})
27667 The Hurd package to use.
27671 @defvr {Scheme Variable} hurd-getty-service-type
27672 This service starts a tty using the Hurd @code{getty} program.
27674 The service's value is a @code{hurd-getty-configuration} record.
27677 @deftp {Data Type} hurd-getty-configuration
27678 This is the data type representing the configuration for the
27679 hurd-getty-service.
27682 @item @code{hurd} (default: @var{hurd})
27683 The Hurd package to use.
27686 The name of the console this Getty runs on---e.g., @code{"tty1"}.
27688 @item @code{baud-rate} (default: @code{38400})
27689 An integer specifying the baud rate of the tty.
27694 @node Miscellaneous Services
27695 @subsection Miscellaneous Services
27697 @cindex fingerprint
27698 @subsubheading Fingerprint Service
27700 The @code{(gnu services authentication)} module provides a DBus service to
27701 read and identify fingerprints via a fingerprint sensor.
27703 @defvr {Scheme Variable} fprintd-service-type
27704 The service type for @command{fprintd}, which provides the fingerprint
27705 reading capability.
27708 (service fprintd-service-type)
27713 @subsubheading System Control Service
27715 The @code{(gnu services sysctl)} provides a service to configure kernel
27716 parameters at boot.
27718 @defvr {Scheme Variable} sysctl-service-type
27719 The service type for @command{sysctl}, which modifies kernel parameters
27720 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
27724 (service sysctl-service-type
27725 (sysctl-configuration
27726 (settings '(("net.ipv4.ip_forward" . "1")))))
27730 @deftp {Data Type} sysctl-configuration
27731 The data type representing the configuration of @command{sysctl}.
27734 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
27735 The @command{sysctl} executable to use.
27737 @item @code{settings} (default: @code{'()})
27738 An association list specifies kernel parameters and their values.
27743 @subsubheading PC/SC Smart Card Daemon Service
27745 The @code{(gnu services security-token)} module provides the following service
27746 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
27747 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
27748 manager that coordinates communications with smart card readers, smart cards
27749 and cryptographic tokens that are connected to the system.
27751 @defvr {Scheme Variable} pcscd-service-type
27752 Service type for the @command{pcscd} service. Its value must be a
27753 @code{pcscd-configuration} object. To run pcscd in the default
27754 configuration, instantiate it as:
27757 (service pcscd-service-type)
27761 @deftp {Data Type} pcscd-configuration
27762 The data type representing the configuration of @command{pcscd}.
27765 @item @code{pcsc-lite} (default: @code{pcsc-lite})
27766 The pcsc-lite package that provides pcscd.
27767 @item @code{usb-drivers} (default: @code{(list ccid)})
27768 List of packages that provide USB drivers to pcscd. Drivers are expected to be
27769 under @file{pcsc/drivers} in the store directory of the package.
27774 @subsubheading Lirc Service
27776 The @code{(gnu services lirc)} module provides the following service.
27778 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
27779 [#:device #f] [#:driver #f] [#:config-file #f] @
27780 [#:extra-options '()]
27781 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
27782 decodes infrared signals from remote controls.
27784 Optionally, @var{device}, @var{driver} and @var{config-file}
27785 (configuration file name) may be specified. See @command{lircd} manual
27788 Finally, @var{extra-options} is a list of additional command-line options
27789 passed to @command{lircd}.
27793 @subsubheading Spice Service
27795 The @code{(gnu services spice)} module provides the following service.
27797 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
27798 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
27799 that enables sharing the clipboard with a vm and setting the guest display
27800 resolution when the graphical console window resizes.
27803 @cindex inputattach
27804 @subsubheading inputattach Service
27806 @cindex tablet input, for Xorg
27807 @cindex touchscreen input, for Xorg
27808 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
27809 use input devices such as Wacom tablets, touchscreens, or joysticks with the
27810 Xorg display server.
27812 @deffn {Scheme Variable} inputattach-service-type
27813 Type of a service that runs @command{inputattach} on a device and
27814 dispatches events from it.
27817 @deftp {Data Type} inputattach-configuration
27819 @item @code{device-type} (default: @code{"wacom"})
27820 The type of device to connect to. Run @command{inputattach --help}, from the
27821 @code{inputattach} package, to see the list of supported device types.
27823 @item @code{device} (default: @code{"/dev/ttyS0"})
27824 The device file to connect to the device.
27826 @item @code{baud-rate} (default: @code{#f})
27827 Baud rate to use for the serial connection.
27828 Should be a number or @code{#f}.
27830 @item @code{log-file} (default: @code{#f})
27831 If true, this must be the name of a file to log messages to.
27835 @subsubheading Dictionary Service
27837 The @code{(gnu services dict)} module provides the following service:
27839 @defvr {Scheme Variable} dicod-service-type
27840 This is the type of the service that runs the @command{dicod} daemon, an
27841 implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
27844 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
27845 Return a service that runs the @command{dicod} daemon, an implementation
27846 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
27848 The optional @var{config} argument specifies the configuration for
27849 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
27850 default it serves the GNU Collaborative International Dictionary of English.
27852 You can add @command{open localhost} to your @file{~/.dico} file to make
27853 @code{localhost} the default server for @command{dico} client
27854 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
27857 @deftp {Data Type} dicod-configuration
27858 Data type representing the configuration of dicod.
27861 @item @code{dico} (default: @var{dico})
27862 Package object of the GNU Dico dictionary server.
27864 @item @code{interfaces} (default: @var{'("localhost")})
27865 This is the list of IP addresses and ports and possibly socket file
27866 names to listen to (@pxref{Server Settings, @code{listen} directive,,
27867 dico, GNU Dico Manual}).
27869 @item @code{handlers} (default: @var{'()})
27870 List of @code{<dicod-handler>} objects denoting handlers (module instances).
27872 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
27873 List of @code{<dicod-database>} objects denoting dictionaries to be served.
27877 @deftp {Data Type} dicod-handler
27878 Data type representing a dictionary handler (module instance).
27882 Name of the handler (module instance).
27884 @item @code{module} (default: @var{#f})
27885 Name of the dicod module of the handler (instance). If it is @code{#f},
27886 the module has the same name as the handler.
27887 (@pxref{Modules,,, dico, GNU Dico Manual}).
27889 @item @code{options}
27890 List of strings or gexps representing the arguments for the module handler
27894 @deftp {Data Type} dicod-database
27895 Data type representing a dictionary database.
27899 Name of the database, will be used in DICT commands.
27901 @item @code{handler}
27902 Name of the dicod handler (module instance) used by this database
27903 (@pxref{Handlers,,, dico, GNU Dico Manual}).
27905 @item @code{complex?} (default: @var{#f})
27906 Whether the database configuration complex. The complex configuration
27907 will need a corresponding @code{<dicod-handler>} object, otherwise not.
27909 @item @code{options}
27910 List of strings or gexps representing the arguments for the database
27911 (@pxref{Databases,,, dico, GNU Dico Manual}).
27915 @defvr {Scheme Variable} %dicod-database:gcide
27916 A @code{<dicod-database>} object serving the GNU Collaborative International
27917 Dictionary of English using the @code{gcide} package.
27920 The following is an example @code{dicod-service} configuration.
27923 (dicod-service #:config
27924 (dicod-configuration
27925 (handlers (list (dicod-handler
27929 (list #~(string-append "dbdir=" #$wordnet))))))
27930 (databases (list (dicod-database
27933 (handler "wordnet")
27934 (options '("database=wn")))
27935 %dicod-database:gcide))))
27939 @subsubheading Docker Service
27941 The @code{(gnu services docker)} module provides the following services.
27943 @defvr {Scheme Variable} docker-service-type
27945 This is the type of the service that runs @url{https://www.docker.com,Docker},
27946 a daemon that can execute application bundles (sometimes referred to as
27947 ``containers'') in isolated environments.
27951 @deftp {Data Type} docker-configuration
27952 This is the data type representing the configuration of Docker and Containerd.
27956 @item @code{package} (default: @code{docker})
27957 The Docker package to use.
27959 @item @code{containerd} (default: @var{containerd})
27960 The Containerd package to use.
27962 @item @code{proxy} (default @var{docker-libnetwork-cmd-proxy})
27963 The Docker user-land networking proxy package to use.
27965 @item @code{enable-proxy?} (default @code{#f})
27966 Enable or disable the use of the Docker user-land networking proxy.
27968 @item @code{debug?} (default @code{#f})
27969 Enable or disable debug output.
27971 @item @code{enable-iptables?} (default @code{#t})
27972 Enable or disable the addition of iptables rules.
27978 @subsubheading Auditd Service
27980 The @code{(gnu services auditd)} module provides the following service.
27982 @defvr {Scheme Variable} auditd-service-type
27984 This is the type of the service that runs
27985 @url{https://people.redhat.com/sgrubb/audit/,auditd},
27986 a daemon that tracks security-relevant information on your system.
27988 Examples of things that can be tracked:
27998 Failed login attempts
28005 @command{auditctl} from the @code{audit} package can be used in order
28006 to add or remove events to be tracked (until the next reboot).
28007 In order to permanently track events, put the command line arguments
28008 of auditctl into a file called @code{audit.rules} in the configuration
28009 directory (see below).
28010 @command{aureport} from the @code{audit} package can be used in order
28011 to view a report of all recorded events.
28012 The audit daemon by default logs into the file
28013 @file{/var/log/audit.log}.
28017 @deftp {Data Type} auditd-configuration
28018 This is the data type representing the configuration of auditd.
28022 @item @code{audit} (default: @code{audit})
28023 The audit package to use.
28025 @item @code{configuration-directory} (default: @code{%default-auditd-configuration-directory})
28026 The directory containing the configuration file for the audit package, which
28027 must be named @code{auditd.conf}, and optionally some audit rules to
28028 instantiate on startup.
28033 @defvr {Scheme Variable} singularity-service-type
28034 This is the type of the service that allows you to run
28035 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
28036 create and run application bundles (aka. ``containers''). The value for this
28037 service is the Singularity package to use.
28039 The service does not install a daemon; instead, it installs helper programs as
28040 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
28041 @command{singularity run} and similar commands.
28045 @subsubheading R-Shiny service
28047 The @code{(gnu services science)} module provides the following service.
28049 @defvr {Scheme Variable} rshiny-service-type
28051 This is a type of service which is used to run a webapp created with
28052 @code{r-shiny}. This service sets the @code{R_LIBS_USER} environment
28053 variable and runs the provided script to call @code{runApp}.
28055 @deftp {Data Type} rshiny-configuration
28056 This is the data type representing the configuration of rshiny.
28060 @item @code{package} (default: @code{r-shiny})
28061 The package to use.
28063 @item @code{binary} (defaunlt @code{"rshiny"})
28064 The name of the binary or shell script located at @code{package/bin/} to
28065 run when the service is run.
28067 The common way to create this file is as follows:
28071 (let* ((out (assoc-ref %outputs "out"))
28072 (targetdir (string-append out "/share/" ,name))
28073 (app (string-append out "/bin/" ,name))
28074 (Rbin (string-append (assoc-ref %build-inputs "r-min")
28077 (mkdir-p (string-append out "/bin"))
28078 (call-with-output-file app
28084 runApp(launch.browser=0, port=4202)~%\n"
28093 @subsubheading Nix service
28095 The @code{(gnu services nix)} module provides the following service.
28097 @defvr {Scheme Variable} nix-service-type
28099 This is the type of the service that runs build daemon of the
28100 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
28104 (use-modules (gnu))
28105 (use-service-modules nix)
28106 (use-package-modules package-management)
28110 (packages (append (list nix)
28113 (services (append (list (service nix-service-type))
28117 After @command{guix system reconfigure} configure Nix for your user:
28120 @item Add a Nix channel and update it. See
28121 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
28123 @item Create a symlink to your profile and activate Nix profile:
28127 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
28128 $ source /run/current-system/profile/etc/profile.d/nix.sh
28133 @deftp {Data Type} nix-configuration
28134 This data type represents the configuration of the Nix daemon.
28137 @item @code{nix} (default: @code{nix})
28138 The Nix package to use.
28140 @item @code{sandbox} (default: @code{#t})
28141 Specifies whether builds are sandboxed by default.
28143 @item @code{build-sandbox-items} (default: @code{'()})
28144 This is a list of strings or objects appended to the
28145 @code{build-sandbox-items} field of the configuration file.
28147 @item @code{extra-config} (default: @code{'()})
28148 This is a list of strings or objects appended to the configuration file.
28149 It is used to pass extra text to be added verbatim to the configuration
28152 @item @code{extra-options} (default: @code{'()})
28153 Extra command line options for @code{nix-service-type}.
28157 @node Setuid Programs
28158 @section Setuid Programs
28160 @cindex setuid programs
28161 Some programs need to run with ``root'' privileges, even when they are
28162 launched by unprivileged users. A notorious example is the
28163 @command{passwd} program, which users can run to change their
28164 password, and which needs to access the @file{/etc/passwd} and
28165 @file{/etc/shadow} files---something normally restricted to root, for
28166 obvious security reasons. To address that, these executables are
28167 @dfn{setuid-root}, meaning that they always run with root privileges
28168 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
28169 for more info about the setuid mechanism).
28171 The store itself @emph{cannot} contain setuid programs: that would be a
28172 security issue since any user on the system can write derivations that
28173 populate the store (@pxref{The Store}). Thus, a different mechanism is
28174 used: instead of changing the setuid bit directly on files that are in
28175 the store, we let the system administrator @emph{declare} which programs
28176 should be setuid root.
28178 The @code{setuid-programs} field of an @code{operating-system}
28179 declaration contains a list of G-expressions denoting the names of
28180 programs to be setuid-root (@pxref{Using the Configuration System}).
28181 For instance, the @command{passwd} program, which is part of the Shadow
28182 package, can be designated by this G-expression (@pxref{G-Expressions}):
28185 #~(string-append #$shadow "/bin/passwd")
28188 A default set of setuid programs is defined by the
28189 @code{%setuid-programs} variable of the @code{(gnu system)} module.
28191 @defvr {Scheme Variable} %setuid-programs
28192 A list of G-expressions denoting common programs that are setuid-root.
28194 The list includes commands such as @command{passwd}, @command{ping},
28195 @command{su}, and @command{sudo}.
28198 Under the hood, the actual setuid programs are created in the
28199 @file{/run/setuid-programs} directory at system activation time. The
28200 files in this directory refer to the ``real'' binaries, which are in the
28203 @node X.509 Certificates
28204 @section X.509 Certificates
28206 @cindex HTTPS, certificates
28207 @cindex X.509 certificates
28209 Web servers available over HTTPS (that is, HTTP over the transport-layer
28210 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
28211 that the client can then use to @emph{authenticate} the server. To do
28212 that, clients verify that the server's certificate is signed by a
28213 so-called @dfn{certificate authority} (CA). But to verify the CA's
28214 signature, clients must have first acquired the CA's certificate.
28216 Web browsers such as GNU@tie{}IceCat include their own set of CA
28217 certificates, such that they are able to verify CA signatures
28220 However, most other programs that can talk HTTPS---@command{wget},
28221 @command{git}, @command{w3m}, etc.---need to be told where CA
28222 certificates can be found.
28224 @cindex @code{nss-certs}
28225 In Guix, this is done by adding a package that provides certificates
28226 to the @code{packages} field of the @code{operating-system} declaration
28227 (@pxref{operating-system Reference}). Guix includes one such package,
28228 @code{nss-certs}, which is a set of CA certificates provided as part of
28229 Mozilla's Network Security Services.
28231 Note that it is @emph{not} part of @code{%base-packages}, so you need to
28232 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
28233 most applications and libraries look for certificates by default, points
28234 to the certificates installed globally.
28236 Unprivileged users, including users of Guix on a foreign distro,
28237 can also install their own certificate package in
28238 their profile. A number of environment variables need to be defined so
28239 that applications and libraries know where to find them. Namely, the
28240 OpenSSL library honors the @env{SSL_CERT_DIR} and @env{SSL_CERT_FILE}
28241 variables. Some applications add their own environment variables; for
28242 instance, the Git version control system honors the certificate bundle
28243 pointed to by the @env{GIT_SSL_CAINFO} environment variable. Thus, you
28244 would typically run something like:
28247 guix install nss-certs
28248 export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
28249 export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
28250 export GIT_SSL_CAINFO="$SSL_CERT_FILE"
28253 As another example, R requires the @env{CURL_CA_BUNDLE} environment
28254 variable to point to a certificate bundle, so you would have to run
28255 something like this:
28258 guix install nss-certs
28259 export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
28262 For other applications you may want to look up the required environment
28263 variable in the relevant documentation.
28266 @node Name Service Switch
28267 @section Name Service Switch
28269 @cindex name service switch
28271 The @code{(gnu system nss)} module provides bindings to the
28272 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
28273 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
28274 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
28275 extended with new ``name'' lookup methods for system databases, which
28276 includes host names, service names, user accounts, and more (@pxref{Name
28277 Service Switch, System Databases and Name Service Switch,, libc, The GNU
28278 C Library Reference Manual}).
28280 The NSS configuration specifies, for each system database, which lookup
28281 method is to be used, and how the various methods are chained
28282 together---for instance, under which circumstances NSS should try the
28283 next method in the list. The NSS configuration is given in the
28284 @code{name-service-switch} field of @code{operating-system} declarations
28285 (@pxref{operating-system Reference, @code{name-service-switch}}).
28288 @cindex .local, host name lookup
28289 As an example, the declaration below configures the NSS to use the
28290 @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
28291 back-end}, which supports host name lookups over multicast DNS (mDNS)
28292 for host names ending in @code{.local}:
28295 (name-service-switch
28296 (hosts (list %files ;first, check /etc/hosts
28298 ;; If the above did not succeed, try
28299 ;; with 'mdns_minimal'.
28301 (name "mdns_minimal")
28303 ;; 'mdns_minimal' is authoritative for
28304 ;; '.local'. When it returns "not found",
28305 ;; no need to try the next methods.
28306 (reaction (lookup-specification
28307 (not-found => return))))
28309 ;; Then fall back to DNS.
28313 ;; Finally, try with the "full" 'mdns'.
28318 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
28319 contains this configuration, so you will not have to type it if all you
28320 want is to have @code{.local} host lookup working.
28322 Note that, in this case, in addition to setting the
28323 @code{name-service-switch} of the @code{operating-system} declaration,
28324 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
28325 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
28326 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
28327 to the name service cache daemon (@pxref{Base Services,
28328 @code{nscd-service}}).
28330 For convenience, the following variables provide typical NSS
28333 @defvr {Scheme Variable} %default-nss
28334 This is the default name service switch configuration, a
28335 @code{name-service-switch} object.
28338 @defvr {Scheme Variable} %mdns-host-lookup-nss
28339 This is the name service switch configuration with support for host name
28340 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
28343 The reference for name service switch configuration is given below. It
28344 is a direct mapping of the configuration file format of the C library , so
28345 please refer to the C library manual for more information (@pxref{NSS
28346 Configuration File,,, libc, The GNU C Library Reference Manual}).
28347 Compared to the configuration file format of libc NSS, it has the advantage
28348 not only of adding this warm parenthetic feel that we like, but also
28349 static checks: you will know about syntax errors and typos as soon as you
28350 run @command{guix system}.
28352 @deftp {Data Type} name-service-switch
28354 This is the data type representation the configuration of libc's name
28355 service switch (NSS). Each field below represents one of the supported
28372 The system databases handled by the NSS. Each of these fields must be a
28373 list of @code{<name-service>} objects (see below).
28377 @deftp {Data Type} name-service
28379 This is the data type representing an actual name service and the
28380 associated lookup action.
28384 A string denoting the name service (@pxref{Services in the NSS
28385 configuration,,, libc, The GNU C Library Reference Manual}).
28387 Note that name services listed here must be visible to nscd. This is
28388 achieved by passing the @code{#:name-services} argument to
28389 @code{nscd-service} the list of packages providing the needed name
28390 services (@pxref{Base Services, @code{nscd-service}}).
28393 An action specified using the @code{lookup-specification} macro
28394 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
28395 Reference Manual}). For example:
28398 (lookup-specification (unavailable => continue)
28399 (success => return))
28404 @node Initial RAM Disk
28405 @section Initial RAM Disk
28408 @cindex initial RAM disk
28409 For bootstrapping purposes, the Linux-Libre kernel is passed an
28410 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
28411 root file system as well as an initialization script. The latter is
28412 responsible for mounting the real root file system, and for loading any
28413 kernel modules that may be needed to achieve that.
28415 The @code{initrd-modules} field of an @code{operating-system}
28416 declaration allows you to specify Linux-libre kernel modules that must
28417 be available in the initrd. In particular, this is where you would list
28418 modules needed to actually drive the hard disk where your root partition
28419 is---although the default value of @code{initrd-modules} should cover
28420 most use cases. For example, assuming you need the @code{megaraid_sas}
28421 module in addition to the default modules to be able to access your root
28422 file system, you would write:
28427 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
28430 @defvr {Scheme Variable} %base-initrd-modules
28431 This is the list of kernel modules included in the initrd by default.
28434 Furthermore, if you need lower-level customization, the @code{initrd}
28435 field of an @code{operating-system} declaration allows
28436 you to specify which initrd you would like to use. The @code{(gnu
28437 system linux-initrd)} module provides three ways to build an initrd: the
28438 high-level @code{base-initrd} procedure and the low-level
28439 @code{raw-initrd} and @code{expression->initrd} procedures.
28441 The @code{base-initrd} procedure is intended to cover most common uses.
28442 For example, if you want to add a bunch of kernel modules to be loaded
28443 at boot time, you can define the @code{initrd} field of the operating
28444 system declaration like this:
28447 (initrd (lambda (file-systems . rest)
28448 ;; Create a standard initrd but set up networking
28449 ;; with the parameters QEMU expects by default.
28450 (apply base-initrd file-systems
28451 #:qemu-networking? #t
28455 The @code{base-initrd} procedure also handles common use cases that
28456 involves using the system as a QEMU guest, or as a ``live'' system with
28457 volatile root file system.
28459 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
28460 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
28461 such as trying to guess which kernel modules and packages should be included
28462 to the initrd. An example use of @code{raw-initrd} is when a user has
28463 a custom Linux kernel configuration and default kernel modules included by
28464 @code{base-initrd} are not available.
28466 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
28467 honors several options passed on the Linux kernel command line
28468 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
28469 @code{-append} option of QEMU), notably:
28472 @item --load=@var{boot}
28473 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
28474 program, once it has mounted the root file system.
28476 Guix uses this option to yield control to a boot program that runs the
28477 service activation programs and then spawns the GNU@tie{}Shepherd, the
28478 initialization system.
28480 @item --root=@var{root}
28481 Mount @var{root} as the root file system. @var{root} can be a device
28482 name like @code{/dev/sda1}, a file system label, or a file system UUID.
28483 When unspecified, the device name from the root file system of the
28484 operating system declaration is used.
28486 @item --system=@var{system}
28487 Have @file{/run/booted-system} and @file{/run/current-system} point to
28490 @item modprobe.blacklist=@var{modules}@dots{}
28491 @cindex module, black-listing
28492 @cindex black list, of kernel modules
28493 Instruct the initial RAM disk as well as the @command{modprobe} command
28494 (from the kmod package) to refuse to load @var{modules}. @var{modules}
28495 must be a comma-separated list of module names---e.g.,
28496 @code{usbkbd,9pnet}.
28499 Start a read-eval-print loop (REPL) from the initial RAM disk before it
28500 tries to load kernel modules and to mount the root file system. Our
28501 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
28502 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
28503 Manual}, for more information on Guile's REPL.
28507 Now that you know all the features that initial RAM disks produced by
28508 @code{base-initrd} and @code{raw-initrd} provide,
28509 here is how to use it and customize it further.
28512 @cindex initial RAM disk
28513 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
28514 [#:linux-modules '()] [#:mapped-devices '()] @
28515 [#:keyboard-layout #f] @
28516 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
28517 Return a derivation that builds a raw initrd. @var{file-systems} is
28518 a list of file systems to be mounted by the initrd, possibly in addition to
28519 the root file system specified on the kernel command line via @option{--root}.
28520 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
28521 @var{mapped-devices} is a list of device mappings to realize before
28522 @var{file-systems} are mounted (@pxref{Mapped Devices}).
28523 @var{helper-packages} is a list of packages to be copied in the initrd. It may
28524 include @code{e2fsck/static} or other packages needed by the initrd to check
28525 the root file system.
28527 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
28528 the desired console keyboard layout. This is done before @var{mapped-devices}
28529 are set up and before @var{file-systems} are mounted such that, should the
28530 user need to enter a passphrase or use the REPL, this happens using the
28531 intended keyboard layout.
28533 When @var{qemu-networking?} is true, set up networking with the standard QEMU
28534 parameters. When @var{virtio?} is true, load additional modules so that the
28535 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
28537 When @var{volatile-root?} is true, the root file system is writable but any changes
28541 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
28542 [#:mapped-devices '()] [#:keyboard-layout #f] @
28543 [#:qemu-networking? #f] [#:volatile-root? #f] @
28544 [#:linux-modules '()]
28545 Return as a file-like object a generic initrd, with kernel
28546 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
28547 mounted by the initrd, possibly in addition to the root file system specified
28548 on the kernel command line via @option{--root}. @var{mapped-devices} is a list of device
28549 mappings to realize before @var{file-systems} are mounted.
28551 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
28552 the desired console keyboard layout. This is done before @var{mapped-devices}
28553 are set up and before @var{file-systems} are mounted such that, should the
28554 user need to enter a passphrase or use the REPL, this happens using the
28555 intended keyboard layout.
28557 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
28559 The initrd is automatically populated with all the kernel modules necessary
28560 for @var{file-systems} and for the given options. Additional kernel
28561 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
28562 loaded at boot time in the order in which they appear.
28565 Needless to say, the initrds we produce and use embed a
28566 statically-linked Guile, and the initialization program is a Guile
28567 program. That gives a lot of flexibility. The
28568 @code{expression->initrd} procedure builds such an initrd, given the
28569 program to run in that initrd.
28571 @deffn {Scheme Procedure} expression->initrd @var{exp} @
28572 [#:guile %guile-3.0-static-stripped] [#:name "guile-initrd"]
28573 Return as a file-like object a Linux initrd (a gzipped cpio archive)
28574 containing @var{guile} and that evaluates @var{exp}, a G-expression,
28575 upon booting. All the derivations referenced by @var{exp} are
28576 automatically copied to the initrd.
28579 @node Bootloader Configuration
28580 @section Bootloader Configuration
28583 @cindex boot loader
28585 The operating system supports multiple bootloaders. The bootloader is
28586 configured using @code{bootloader-configuration} declaration. All the
28587 fields of this structure are bootloader agnostic except for one field,
28588 @code{bootloader} that indicates the bootloader to be configured and
28591 Some of the bootloaders do not honor every field of
28592 @code{bootloader-configuration}. For instance, the extlinux
28593 bootloader does not support themes and thus ignores the @code{theme}
28596 @deftp {Data Type} bootloader-configuration
28597 The type of a bootloader configuration declaration.
28601 @item @code{bootloader}
28602 @cindex EFI, bootloader
28603 @cindex UEFI, bootloader
28604 @cindex BIOS, bootloader
28605 The bootloader to use, as a @code{bootloader} object. For now
28606 @code{grub-bootloader}, @code{grub-efi-bootloader},
28607 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
28609 @vindex grub-efi-bootloader
28610 @code{grub-efi-bootloader} allows to boot on modern systems using the
28611 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
28612 use if the installation image contains a @file{/sys/firmware/efi} directory
28613 when you boot it on your system.
28615 @vindex grub-bootloader
28616 @code{grub-bootloader} allows you to boot in particular Intel-based machines
28617 in ``legacy'' BIOS mode.
28619 @cindex ARM, bootloaders
28620 @cindex AArch64, bootloaders
28621 Available bootloaders are described in @code{(gnu bootloader @dots{})}
28622 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
28623 of bootloaders for a wide range of ARM and AArch64 systems, using the
28624 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
28626 @item @code{target}
28627 This is a string denoting the target onto which to install the
28630 The interpretation depends on the bootloader in question. For
28631 @code{grub-bootloader}, for example, it should be a device name understood by
28632 the bootloader @command{installer} command, such as @code{/dev/sda} or
28633 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
28634 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
28635 system, usually @file{/boot/efi}.
28637 @item @code{menu-entries} (default: @code{()})
28638 A possibly empty list of @code{menu-entry} objects (see below), denoting
28639 entries to appear in the bootloader menu, in addition to the current
28640 system entry and the entry pointing to previous system generations.
28642 @item @code{default-entry} (default: @code{0})
28643 The index of the default boot menu entry. Index 0 is for the entry of the
28646 @item @code{timeout} (default: @code{5})
28647 The number of seconds to wait for keyboard input before booting. Set to
28648 0 to boot immediately, and to -1 to wait indefinitely.
28650 @cindex keyboard layout, for the bootloader
28651 @item @code{keyboard-layout} (default: @code{#f})
28652 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
28653 layout, usually US@tie{}English (``qwerty'').
28655 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
28659 This option is currently ignored by bootloaders other than @code{grub} and
28663 @item @code{theme} (default: @var{#f})
28664 The bootloader theme object describing the theme to use. If no theme
28665 is provided, some bootloaders might use a default theme, that's true
28668 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
28669 The output terminals used for the bootloader boot menu, as a list of
28670 symbols. GRUB accepts the values: @code{console}, @code{serial},
28671 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
28672 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
28673 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
28674 configuration,,, grub,GNU GRUB manual}).
28676 @item @code{terminal-inputs} (default: @code{'()})
28677 The input terminals used for the bootloader boot menu, as a list of
28678 symbols. For GRUB, the default is the native platform terminal as
28679 determined at run-time. GRUB accepts the values: @code{console},
28680 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
28681 @code{usb_keyboard}. This field corresponds to the GRUB variable
28682 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
28685 @item @code{serial-unit} (default: @code{#f})
28686 The serial unit used by the bootloader, as an integer from 0 to 3.
28687 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
28688 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
28690 @item @code{serial-speed} (default: @code{#f})
28691 The speed of the serial interface, as an integer. For GRUB, the
28692 default value is chosen at run-time; currently GRUB chooses
28693 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
28700 Should you want to list additional boot menu entries @i{via} the
28701 @code{menu-entries} field above, you will need to create them with the
28702 @code{menu-entry} form. For example, imagine you want to be able to
28703 boot another distro (hard to imagine!), you can define a menu entry
28708 (label "The Other Distro")
28709 (linux "/boot/old/vmlinux-2.6.32")
28710 (linux-arguments '("root=/dev/sda2"))
28711 (initrd "/boot/old/initrd"))
28716 @deftp {Data Type} menu-entry
28717 The type of an entry in the bootloader menu.
28722 The label to show in the menu---e.g., @code{"GNU"}.
28724 @item @code{linux} (default: @code{#f})
28725 The Linux kernel image to boot, for example:
28728 (file-append linux-libre "/bzImage")
28731 For GRUB, it is also possible to specify a device explicitly in the
28732 file path using GRUB's device naming convention (@pxref{Naming
28733 convention,,, grub, GNU GRUB manual}), for example:
28736 "(hd0,msdos1)/boot/vmlinuz"
28739 If the device is specified explicitly as above, then the @code{device}
28740 field is ignored entirely.
28742 @item @code{linux-arguments} (default: @code{()})
28743 The list of extra Linux kernel command-line arguments---e.g.,
28744 @code{("console=ttyS0")}.
28746 @item @code{initrd} (default: @code{#f})
28747 A G-Expression or string denoting the file name of the initial RAM disk
28748 to use (@pxref{G-Expressions}).
28750 @item @code{device} (default: @code{#f})
28751 The device where the kernel and initrd are to be found---i.e., for GRUB,
28752 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
28754 This may be a file system label (a string), a file system UUID (a
28755 bytevector, @pxref{File Systems}), or @code{#f}, in which case
28756 the bootloader will search the device containing the file specified by
28757 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
28758 must @emph{not} be an OS device name such as @file{/dev/sda1}.
28760 @item @code{multiboot-kernel} (default: @code{#f})
28761 The kernel to boot in Multiboot-mode (@pxref{multiboot,,, grub, GNU GRUB
28762 manual}). When this field is set, a Multiboot menu-entry is generated.
28766 (file-append mach "/boot/gnumach")
28769 @item @code{multiboot-arguments} (default: @code{()})
28770 The list of extra command-line arguments for the multiboot-kernel.
28772 @item @code{multiboot-modules} (default: @code{()})
28773 The list of commands for loading Multiboot modules. For example:
28776 (list (list (file-append hurd "/hurd/ext2fs.static") "ext2fs"
28778 (list (file-append libc "/lib/ld.so.1") "exec"
28788 @c FIXME: Write documentation once it's stable.
28789 For now only GRUB has theme support. GRUB themes are created using
28790 the @code{grub-theme} form, which is not fully documented yet.
28792 @deftp {Data Type} grub-theme
28793 Data type representing the configuration of the GRUB theme.
28796 @item @code{gfxmode} (default: @code{'("auto")})
28797 The GRUB @code{gfxmode} to set (a list of screen resolution strings, see
28798 @pxref{gfxmode,,, grub, GNU GRUB manual}).
28802 @deffn {Scheme Procedure} grub-theme
28803 Return the default GRUB theme used by the operating system if no
28804 @code{theme} field is specified in @code{bootloader-configuration}
28807 It comes with a fancy background image displaying the GNU and Guix
28811 For example, to override the default resolution, you may use something
28816 (bootloader-configuration
28819 (inherit (grub-theme))
28820 (gfxmode '("1024x786x32" "auto"))))))
28823 @node Invoking guix system
28824 @section Invoking @code{guix system}
28826 Once you have written an operating system declaration as seen in the
28827 previous section, it can be @dfn{instantiated} using the @command{guix
28828 system} command. The synopsis is:
28831 guix system @var{options}@dots{} @var{action} @var{file}
28834 @var{file} must be the name of a file containing an
28835 @code{operating-system} declaration. @var{action} specifies how the
28836 operating system is instantiated. Currently the following values are
28841 Display available service type definitions that match the given regular
28842 expressions, sorted by relevance:
28848 $ guix system search console
28849 name: console-fonts
28850 location: gnu/services/base.scm:806:2
28851 extends: shepherd-root
28852 description: Install the given fonts on the specified ttys (fonts are per
28853 + virtual console on GNU/Linux). The value of this service is a list of
28854 + tty/font pairs. The font can be the name of a font provided by the `kbd'
28855 + package or any valid argument to `setfont', as in this example:
28857 + '(("tty1" . "LatGrkCyr-8x16")
28858 + ("tty2" . (file-append
28860 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
28861 + ("tty3" . (file-append
28863 + "/share/consolefonts/ter-132n"))) ; for HDPI
28867 location: gnu/services/base.scm:1190:2
28868 extends: shepherd-root
28869 description: Provide console login using the `mingetty' program.
28873 location: gnu/services/base.scm:860:2
28875 description: Provide a console log-in service as specified by its
28876 + configuration value, a `login-configuration' object.
28882 As for @command{guix package --search}, the result is written in
28883 @code{recutils} format, which makes it easy to filter the output
28884 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
28887 Build the operating system described in @var{file}, activate it, and
28888 switch to it@footnote{This action (and the related actions
28889 @code{switch-generation} and @code{roll-back}) are usable only on
28890 systems already running Guix System.}.
28893 @c The paragraph below refers to the problem discussed at
28894 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
28895 It is highly recommended to run @command{guix pull} once before you run
28896 @command{guix system reconfigure} for the first time (@pxref{Invoking
28897 guix pull}). Failing to do that you would see an older version of Guix
28898 once @command{reconfigure} has completed.
28901 This effects all the configuration specified in @var{file}: user
28902 accounts, system services, global package list, setuid programs, etc.
28903 The command starts system services specified in @var{file} that are not
28904 currently running; if a service is currently running this command will
28905 arrange for it to be upgraded the next time it is stopped (e.g.@: by
28906 @code{herd stop X} or @code{herd restart X}).
28908 This command creates a new generation whose number is one greater than
28909 the current generation (as reported by @command{guix system
28910 list-generations}). If that generation already exists, it will be
28911 overwritten. This behavior mirrors that of @command{guix package}
28912 (@pxref{Invoking guix package}).
28914 It also adds a bootloader menu entry for the new OS configuration,
28915 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
28916 entries for older configurations to a submenu, allowing you to choose
28917 an older system generation at boot time should you need it.
28919 @cindex provenance tracking, of the operating system
28920 Upon completion, the new system is deployed under
28921 @file{/run/current-system}. This directory contains @dfn{provenance
28922 meta-data}: the list of channels in use (@pxref{Channels}) and
28923 @var{file} itself, when available. You can view it by running:
28926 guix system describe
28929 This information is useful should you later want to inspect how this
28930 particular generation was built. In fact, assuming @var{file} is
28931 self-contained, you can later rebuild generation @var{n} of your
28932 operating system with:
28935 guix time-machine \
28936 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
28937 system reconfigure \
28938 /var/guix/profiles/system-@var{n}-link/configuration.scm
28941 You can think of it as some sort of built-in version control! Your
28942 system is not just a binary artifact: @emph{it carries its own source}.
28943 @xref{Service Reference, @code{provenance-service-type}}, for more
28944 information on provenance tracking.
28946 By default, @command{reconfigure} @emph{prevents you from downgrading
28947 your system}, which could (re)introduce security vulnerabilities and
28948 also cause problems with ``stateful'' services such as database
28949 management systems. You can override that behavior by passing
28950 @option{--allow-downgrades}.
28952 @item switch-generation
28953 @cindex generations
28954 Switch to an existing system generation. This action atomically
28955 switches the system profile to the specified system generation. It
28956 also rearranges the system's existing bootloader menu entries. It
28957 makes the menu entry for the specified system generation the default,
28958 and it moves the entries for the other generations to a submenu, if
28959 supported by the bootloader being used. The next time the system
28960 boots, it will use the specified system generation.
28962 The bootloader itself is not being reinstalled when using this
28963 command. Thus, the installed bootloader is used with an updated
28964 configuration file.
28966 The target generation can be specified explicitly by its generation
28967 number. For example, the following invocation would switch to system
28971 guix system switch-generation 7
28974 The target generation can also be specified relative to the current
28975 generation with the form @code{+N} or @code{-N}, where @code{+3} means
28976 ``3 generations ahead of the current generation,'' and @code{-1} means
28977 ``1 generation prior to the current generation.'' When specifying a
28978 negative value such as @code{-1}, you must precede it with @code{--} to
28979 prevent it from being parsed as an option. For example:
28982 guix system switch-generation -- -1
28985 Currently, the effect of invoking this action is @emph{only} to switch
28986 the system profile to an existing generation and rearrange the
28987 bootloader menu entries. To actually start using the target system
28988 generation, you must reboot after running this action. In the future,
28989 it will be updated to do the same things as @command{reconfigure},
28990 like activating and deactivating services.
28992 This action will fail if the specified generation does not exist.
28995 @cindex rolling back
28996 Switch to the preceding system generation. The next time the system
28997 boots, it will use the preceding system generation. This is the inverse
28998 of @command{reconfigure}, and it is exactly the same as invoking
28999 @command{switch-generation} with an argument of @code{-1}.
29001 Currently, as with @command{switch-generation}, you must reboot after
29002 running this action to actually start using the preceding system
29005 @item delete-generations
29006 @cindex deleting system generations
29007 @cindex saving space
29008 Delete system generations, making them candidates for garbage collection
29009 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
29012 This works in the same way as @samp{guix package --delete-generations}
29013 (@pxref{Invoking guix package, @option{--delete-generations}}). With no
29014 arguments, all system generations but the current one are deleted:
29017 guix system delete-generations
29020 You can also select the generations you want to delete. The example below
29021 deletes all the system generations that are more than two month old:
29024 guix system delete-generations 2m
29027 Running this command automatically reinstalls the bootloader with an updated
29028 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
29029 longer lists the generations that have been deleted.
29032 Build the derivation of the operating system, which includes all the
29033 configuration files and programs needed to boot and run the system.
29034 This action does not actually install anything.
29037 Populate the given directory with all the files necessary to run the
29038 operating system specified in @var{file}. This is useful for first-time
29039 installations of Guix System. For instance:
29042 guix system init my-os-config.scm /mnt
29045 copies to @file{/mnt} all the store items required by the configuration
29046 specified in @file{my-os-config.scm}. This includes configuration
29047 files, packages, and so on. It also creates other essential files
29048 needed for the system to operate correctly---e.g., the @file{/etc},
29049 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
29051 This command also installs bootloader on the target specified in
29052 @file{my-os-config}, unless the @option{--no-bootloader} option was
29056 @cindex virtual machine
29058 @anchor{guix system vm}
29059 Build a virtual machine that contains the operating system declared in
29060 @var{file}, and return a script to run that virtual machine (VM).
29063 The @code{vm} action and others below
29064 can use KVM support in the Linux-libre kernel. Specifically, if the
29065 machine has hardware virtualization support, the corresponding
29066 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
29067 must exist and be readable and writable by the user and by the
29068 build users of the daemon (@pxref{Build Environment Setup}).
29071 Arguments given to the script are passed to QEMU as in the example
29072 below, which enables networking and requests 1@tie{}GiB of RAM for the
29076 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
29079 The VM shares its store with the host system.
29081 Additional file systems can be shared between the host and the VM using
29082 the @option{--share} and @option{--expose} command-line options: the former
29083 specifies a directory to be shared with write access, while the latter
29084 provides read-only access to the shared directory.
29086 The example below creates a VM in which the user's home directory is
29087 accessible read-only, and where the @file{/exchange} directory is a
29088 read-write mapping of @file{$HOME/tmp} on the host:
29091 guix system vm my-config.scm \
29092 --expose=$HOME --share=$HOME/tmp=/exchange
29095 On GNU/Linux, the default is to boot directly to the kernel; this has
29096 the advantage of requiring only a very tiny root disk image since the
29097 store of the host can then be mounted.
29099 The @option{--full-boot} option forces a complete boot sequence, starting
29100 with the bootloader. This requires more disk space since a root image
29101 containing at least the kernel, initrd, and bootloader data files must
29102 be created. The @option{--image-size} option can be used to specify the
29105 @cindex System images, creation in various formats
29106 @cindex Creating system images in various formats
29109 @itemx docker-image
29110 Return a virtual machine, disk image, or Docker image of the operating
29111 system declared in @var{file} that stands alone. By default,
29112 @command{guix system} estimates the size of the image needed to store
29113 the system, but you can use the @option{--image-size} option to specify
29114 a value. Docker images are built to contain exactly what they need, so
29115 the @option{--image-size} option is ignored in the case of
29116 @code{docker-image}.
29118 You can specify the root file system type by using the
29119 @option{--file-system-type} option. It defaults to @code{ext4}. When its
29120 value is @code{iso9660}, the @option{--label} option can be used to specify
29121 a volume ID with @code{disk-image}.
29123 When using @code{vm-image}, the returned image is in qcow2 format, which
29124 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
29125 for more information on how to run the image in a virtual machine.
29127 When using @code{disk-image}, a raw disk image is produced; it can be
29128 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
29129 the device corresponding to a USB stick, one can copy the image to it
29130 using the following command:
29133 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc status=progress
29136 When using @code{docker-image}, a Docker image is produced. Guix builds
29137 the image from scratch, not from a pre-existing Docker base image. As a
29138 result, it contains @emph{exactly} what you define in the operating
29139 system configuration file. You can then load the image and launch a
29140 Docker container using commands like the following:
29143 image_id="`docker load < guix-system-docker-image.tar.gz`"
29144 container_id="`docker create $image_id`"
29145 docker start $container_id
29148 This command starts a new Docker container from the specified image. It
29149 will boot the Guix system in the usual manner, which means it will
29150 start any services you have defined in the operating system
29151 configuration. You can get an interactive shell running in the container
29152 using @command{docker exec}:
29155 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
29158 Depending on what you run in the Docker container, it
29159 may be necessary to give the container additional permissions. For
29160 example, if you intend to build software using Guix inside of the Docker
29161 container, you may need to pass the @option{--privileged} option to
29162 @code{docker create}.
29164 Last, the @option{--network} option applies to @command{guix system
29165 docker-image}: it produces an image where network is supposedly shared
29166 with the host, and thus without services like nscd or NetworkManager.
29169 Return a script to run the operating system declared in @var{file}
29170 within a container. Containers are a set of lightweight isolation
29171 mechanisms provided by the kernel Linux-libre. Containers are
29172 substantially less resource-demanding than full virtual machines since
29173 the kernel, shared objects, and other resources can be shared with the
29174 host system; this also means they provide thinner isolation.
29176 Currently, the script must be run as root in order to support more than
29177 a single user and group. The container shares its store with the host
29180 As with the @code{vm} action (@pxref{guix system vm}), additional file
29181 systems to be shared between the host and container can be specified
29182 using the @option{--share} and @option{--expose} options:
29185 guix system container my-config.scm \
29186 --expose=$HOME --share=$HOME/tmp=/exchange
29190 This option requires Linux-libre 3.19 or newer.
29195 @var{options} can contain any of the common build options (@pxref{Common
29196 Build Options}). In addition, @var{options} can contain one of the
29200 @item --expression=@var{expr}
29201 @itemx -e @var{expr}
29202 Consider the operating-system @var{expr} evaluates to.
29203 This is an alternative to specifying a file which evaluates to an
29205 This is used to generate the Guix system installer @pxref{Building the
29206 Installation Image}).
29208 @item --system=@var{system}
29209 @itemx -s @var{system}
29210 Attempt to build for @var{system} instead of the host system type.
29211 This works as per @command{guix build} (@pxref{Invoking guix build}).
29215 Return the derivation file name of the given operating system without
29218 @cindex provenance tracking, of the operating system
29219 @item --save-provenance
29220 As discussed above, @command{guix system init} and @command{guix system
29221 reconfigure} always save provenance information @i{via} a dedicated
29222 service (@pxref{Service Reference, @code{provenance-service-type}}).
29223 However, other commands don't do that by default. If you wish to, say,
29224 create a virtual machine image that contains provenance information, you
29228 guix system vm-image --save-provenance config.scm
29231 That way, the resulting image will effectively ``embed its own source''
29232 in the form of meta-data in @file{/run/current-system}. With that
29233 information, one can rebuild the image to make sure it really contains
29234 what it pretends to contain; or they could use that to derive a variant
29237 @item --file-system-type=@var{type}
29238 @itemx -t @var{type}
29239 For the @code{disk-image} action, create a file system of the given
29240 @var{type} on the image.
29242 When this option is omitted, @command{guix system} uses @code{ext4}.
29244 @cindex ISO-9660 format
29245 @cindex CD image format
29246 @cindex DVD image format
29247 @option{--file-system-type=iso9660} produces an ISO-9660 image, suitable
29248 for burning on CDs and DVDs.
29250 @item --image-size=@var{size}
29251 For the @code{vm-image} and @code{disk-image} actions, create an image
29252 of the given @var{size}. @var{size} may be a number of bytes, or it may
29253 include a unit as a suffix (@pxref{Block size, size specifications,,
29254 coreutils, GNU Coreutils}).
29256 When this option is omitted, @command{guix system} computes an estimate
29257 of the image size as a function of the size of the system declared in
29262 For the @code{container} action, allow containers to access the host network,
29263 that is, do not create a network namespace.
29265 @item --root=@var{file}
29266 @itemx -r @var{file}
29267 Make @var{file} a symlink to the result, and register it as a garbage
29270 @item --skip-checks
29271 Skip pre-installation safety checks.
29273 By default, @command{guix system init} and @command{guix system
29274 reconfigure} perform safety checks: they make sure the file systems that
29275 appear in the @code{operating-system} declaration actually exist
29276 (@pxref{File Systems}), and that any Linux kernel modules that may be
29277 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
29278 RAM Disk}). Passing this option skips these tests altogether.
29280 @item --allow-downgrades
29281 Instruct @command{guix system reconfigure} to allow system downgrades.
29283 By default, @command{reconfigure} prevents you from downgrading your
29284 system. It achieves that by comparing the provenance info of your
29285 system (shown by @command{guix system describe}) with that of your
29286 @command{guix} command (shown by @command{guix describe}). If the
29287 commits for @command{guix} are not descendants of those used for your
29288 system, @command{guix system reconfigure} errors out. Passing
29289 @option{--allow-downgrades} allows you to bypass these checks.
29292 Make sure you understand its security implications before using
29293 @option{--allow-downgrades}.
29297 @cindex on-error strategy
29298 @cindex error strategy
29299 @item --on-error=@var{strategy}
29300 Apply @var{strategy} when an error occurs when reading @var{file}.
29301 @var{strategy} may be one of the following:
29304 @item nothing-special
29305 Report the error concisely and exit. This is the default strategy.
29308 Likewise, but also display a backtrace.
29311 Report the error and enter Guile's debugger. From there, you can run
29312 commands such as @code{,bt} to get a backtrace, @code{,locals} to
29313 display local variable values, and more generally inspect the state of the
29314 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
29315 a list of available debugging commands.
29319 Once you have built, configured, re-configured, and re-re-configured
29320 your Guix installation, you may find it useful to list the operating
29321 system generations available on disk---and that you can choose from the
29322 bootloader boot menu:
29327 Describe the current system generation: its file name, the kernel and
29328 bootloader used, etc., as well as provenance information when available.
29330 @item list-generations
29331 List a summary of each generation of the operating system available on
29332 disk, in a human-readable way. This is similar to the
29333 @option{--list-generations} option of @command{guix package}
29334 (@pxref{Invoking guix package}).
29336 Optionally, one can specify a pattern, with the same syntax that is used
29337 in @command{guix package --list-generations}, to restrict the list of
29338 generations displayed. For instance, the following command displays
29339 generations that are up to 10 days old:
29342 $ guix system list-generations 10d
29347 The @command{guix system} command has even more to offer! The following
29348 sub-commands allow you to visualize how your system services relate to
29351 @anchor{system-extension-graph}
29354 @item extension-graph
29355 Emit in Dot/Graphviz format to standard output the @dfn{service
29356 extension graph} of the operating system defined in @var{file}
29357 (@pxref{Service Composition}, for more information on service
29363 $ guix system extension-graph @var{file} | xdot -
29366 shows the extension relations among services.
29368 @anchor{system-shepherd-graph}
29369 @item shepherd-graph
29370 Emit in Dot/Graphviz format to standard output the @dfn{dependency
29371 graph} of shepherd services of the operating system defined in
29372 @var{file}. @xref{Shepherd Services}, for more information and for an
29377 @node Invoking guix deploy
29378 @section Invoking @code{guix deploy}
29380 We've already seen @code{operating-system} declarations used to manage a
29381 machine's configuration locally. Suppose you need to configure multiple
29382 machines, though---perhaps you're managing a service on the web that's
29383 comprised of several servers. @command{guix deploy} enables you to use those
29384 same @code{operating-system} declarations to manage multiple remote hosts at
29385 once as a logical ``deployment''.
29388 The functionality described in this section is still under development
29389 and is subject to change. Get in touch with us on
29390 @email{guix-devel@@gnu.org}!
29394 guix deploy @var{file}
29397 Such an invocation will deploy the machines that the code within @var{file}
29398 evaluates to. As an example, @var{file} might contain a definition like this:
29401 ;; This is a Guix deployment of a "bare bones" setup, with
29402 ;; no X11 display server, to a machine with an SSH daemon
29403 ;; listening on localhost:2222. A configuration such as this
29404 ;; may be appropriate for virtual machine with ports
29405 ;; forwarded to the host's loopback interface.
29407 (use-service-modules networking ssh)
29408 (use-package-modules bootloaders)
29412 (host-name "gnu-deployed")
29413 (timezone "Etc/UTC")
29414 (bootloader (bootloader-configuration
29415 (bootloader grub-bootloader)
29416 (target "/dev/vda")
29417 (terminal-outputs '(console))))
29418 (file-systems (cons (file-system
29420 (device "/dev/vda1")
29422 %base-file-systems))
29424 (append (list (service dhcp-client-service-type)
29425 (service openssh-service-type
29426 (openssh-configuration
29427 (permit-root-login #t)
29428 (allow-empty-passwords? #t))))
29432 (operating-system %system)
29433 (environment managed-host-environment-type)
29434 (configuration (machine-ssh-configuration
29435 (host-name "localhost")
29436 (system "x86_64-linux")
29438 (identity "./id_rsa")
29442 The file should evaluate to a list of @var{machine} objects. This example,
29443 upon being deployed, will create a new generation on the remote system
29444 realizing the @code{operating-system} declaration @code{%system}.
29445 @code{environment} and @code{configuration} specify how the machine should be
29446 provisioned---that is, how the computing resources should be created and
29447 managed. The above example does not create any resources, as a
29448 @code{'managed-host} is a machine that is already running the Guix system and
29449 available over the network. This is a particularly simple case; a more
29450 complex deployment may involve, for example, starting virtual machines through
29451 a Virtual Private Server (VPS) provider. In such a case, a different
29452 @var{environment} type would be used.
29454 Do note that you first need to generate a key pair on the coordinator machine
29455 to allow the daemon to export signed archives of files from the store
29456 (@pxref{Invoking guix archive}).
29459 # guix archive --generate-key
29463 Each target machine must authorize the key of the master machine so that it
29464 accepts store items it receives from the coordinator:
29467 # guix archive --authorize < coordinator-public-key.txt
29470 @code{user}, in this example, specifies the name of the user account to log in
29471 as to perform the deployment. Its default value is @code{root}, but root
29472 login over SSH may be forbidden in some cases. To work around this,
29473 @command{guix deploy} can log in as an unprivileged user and employ
29474 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
29475 currently installed on the remote and can be invoked non-interactively as
29476 @code{user}. That is, the line in @code{sudoers} granting @code{user} the
29477 ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
29478 be accomplished with the following operating system configuration snippet:
29482 (gnu system)) ;for %sudoers-specification
29484 (define %user "username")
29489 (plain-file "sudoers"
29490 (string-append (plain-file-content %sudoers-specification)
29491 (format #f "~a ALL = NOPASSWD: ALL~%"
29496 For more information regarding the format of the @file{sudoers} file,
29497 consult @command{man sudoers}.
29499 @deftp {Data Type} machine
29500 This is the data type representing a single machine in a heterogeneous Guix
29504 @item @code{operating-system}
29505 The object of the operating system configuration to deploy.
29507 @item @code{environment}
29508 An @code{environment-type} describing how the machine should be provisioned.
29510 @item @code{configuration} (default: @code{#f})
29511 An object describing the configuration for the machine's @code{environment}.
29512 If the @code{environment} has a default configuration, @code{#f} may be used.
29513 If @code{#f} is used for an environment with no default configuration,
29514 however, an error will be thrown.
29518 @deftp {Data Type} machine-ssh-configuration
29519 This is the data type representing the SSH client parameters for a machine
29520 with an @code{environment} of @code{managed-host-environment-type}.
29523 @item @code{host-name}
29524 @item @code{build-locally?} (default: @code{#t})
29525 If false, system derivations will be built on the machine being deployed to.
29526 @item @code{system}
29527 The system type describing the architecture of the machine being deployed
29528 to---e.g., @code{"x86_64-linux"}.
29529 @item @code{authorize?} (default: @code{#t})
29530 If true, the coordinator's signing key will be added to the remote's ACL
29532 @item @code{port} (default: @code{22})
29533 @item @code{user} (default: @code{"root"})
29534 @item @code{identity} (default: @code{#f})
29535 If specified, the path to the SSH private key to use to authenticate with the
29538 @item @code{host-key} (default: @code{#f})
29539 This should be the SSH host key of the machine, which looks like this:
29542 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
29545 When @code{host-key} is @code{#f}, the server is authenticated against
29546 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
29549 @item @code{allow-downgrades?} (default: @code{#f})
29550 Whether to allow potential downgrades.
29552 Like @command{guix system reconfigure}, @command{guix deploy} compares
29553 the channel commits currently deployed on the remote host (as returned
29554 by @command{guix system describe}) to those currently in use (as
29555 returned by @command{guix describe}) to determine whether commits
29556 currently in use are descendants of those deployed. When this is not
29557 the case and @code{allow-downgrades?} is false, it raises an error.
29558 This ensures you do not accidentally downgrade remote machines.
29562 @deftp {Data Type} digital-ocean-configuration
29563 This is the data type describing the Droplet that should be created for a
29564 machine with an @code{environment} of @code{digital-ocean-environment-type}.
29567 @item @code{ssh-key}
29568 The path to the SSH private key to use to authenticate with the remote
29569 host. In the future, this field may not exist.
29571 A list of string ``tags'' that uniquely identify the machine. Must be given
29572 such that no two machines in the deployment have the same set of tags.
29573 @item @code{region}
29574 A Digital Ocean region slug, such as @code{"nyc3"}.
29576 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
29577 @item @code{enable-ipv6?}
29578 Whether or not the droplet should be created with IPv6 networking.
29582 @node Running Guix in a VM
29583 @section Running Guix in a Virtual Machine
29585 @cindex virtual machine
29586 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
29588 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
29589 This image is a compressed image in QCOW format. You will first need to
29590 decompress with @command{xz -d}, and then you can pass it to an emulator such
29591 as QEMU (see below for details).
29593 This image boots the Xfce graphical environment and it contains some
29594 commonly-used tools. You can install more software in the image by running
29595 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
29596 also reconfigure the system based on its initial configuration file available
29597 as @file{/run/current-system/configuration.scm} (@pxref{Using the
29598 Configuration System}).
29600 Instead of using this pre-built image, one can also build their own virtual
29601 machine image using @command{guix system vm-image} (@pxref{Invoking guix
29602 system}). The returned image is in qcow2 format, which the
29603 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
29606 If you built your own image, you must copy it out of the store
29607 (@pxref{The Store}) and give yourself permission to write to the copy
29608 before you can use it. When invoking QEMU, you must choose a system
29609 emulator that is suitable for your hardware platform. Here is a minimal
29610 QEMU invocation that will boot the result of @command{guix system
29611 vm-image} on x86_64 hardware:
29614 $ qemu-system-x86_64 \
29615 -nic user,model=virtio-net-pci \
29616 -enable-kvm -m 1024 \
29617 -device virtio-blk,drive=myhd \
29618 -drive if=none,file=/tmp/qemu-image,id=myhd
29621 Here is what each of these options means:
29624 @item qemu-system-x86_64
29625 This specifies the hardware platform to emulate. This should match the
29628 @item -nic user,model=virtio-net-pci
29629 Enable the unprivileged user-mode network stack. The guest OS can
29630 access the host but not vice versa. This is the simplest way to get the
29631 guest OS online. @code{model} specifies which network device to emulate:
29632 @code{virtio-net-pci} is a special device made for virtualized operating
29633 systems and recommended for most uses. Assuming your hardware platform is
29634 x86_64, you can get a list of available NIC models by running
29635 @command{qemu-system-x86_64 -nic model=help}.
29638 If your system has hardware virtualization extensions, enabling the
29639 virtual machine support (KVM) of the Linux kernel will make things run
29642 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
29644 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
29645 which may be insufficient for some operations.
29647 @item -device virtio-blk,drive=myhd
29648 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
29649 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
29650 better performance than if it were emulating a complete disk drive. See the
29651 QEMU and KVM documentation for more info.
29653 @item -drive if=none,file=/tmp/qemu-image,id=myhd
29654 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
29655 the ``myhd'' drive.
29658 The default @command{run-vm.sh} script that is returned by an invocation of
29659 @command{guix system vm} does not add a @command{-nic user} flag by default.
29660 To get network access from within the vm add the @code{(dhcp-client-service)}
29661 to your system definition and start the VM using
29662 @command{`guix system vm config.scm` -nic user}. An important caveat of using
29663 @command{-nic user} for networking is that @command{ping} will not work, because
29664 it uses the ICMP protocol. You'll have to use a different command to check for
29665 network connectivity, for example @command{guix download}.
29667 @subsection Connecting Through SSH
29671 To enable SSH inside a VM you need to add an SSH server like
29672 @code{openssh-service-type} to your VM (@pxref{Networking Services,
29673 @code{openssh-service-type}}). In addition you need to forward the SSH port,
29674 22 by default, to the host. You can do this with
29677 `guix system vm config.scm` -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
29680 To connect to the VM you can run
29683 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
29686 The @command{-p} tells @command{ssh} the port you want to connect to.
29687 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
29688 every time you modify your @command{config.scm} file and the
29689 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
29690 connection to an unknown host every time you connect.
29692 @subsection Using @command{virt-viewer} with Spice
29694 As an alternative to the default @command{qemu} graphical client you can
29695 use the @command{remote-viewer} from the @command{virt-viewer} package. To
29696 connect pass the @command{-spice port=5930,disable-ticketing} flag to
29697 @command{qemu}. See previous section for further information on how to do this.
29699 Spice also allows you to do some nice stuff like share your clipboard with your
29700 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
29703 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
29704 -chardev spicevmc,name=vdagent,id=vdagent
29705 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
29706 name=com.redhat.spice.0
29709 You'll also need to add the @code{(spice-vdagent-service)} to your
29710 system definition (@pxref{Miscellaneous Services, Spice service}).
29712 @node Defining Services
29713 @section Defining Services
29715 The previous sections show the available services and how one can combine
29716 them in an @code{operating-system} declaration. But how do we define
29717 them in the first place? And what is a service anyway?
29720 * Service Composition:: The model for composing services.
29721 * Service Types and Services:: Types and services.
29722 * Service Reference:: API reference.
29723 * Shepherd Services:: A particular type of service.
29726 @node Service Composition
29727 @subsection Service Composition
29731 Here we define a @dfn{service} as, broadly, something that extends the
29732 functionality of the operating system. Often a service is a process---a
29733 @dfn{daemon}---started when the system boots: a secure shell server, a
29734 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
29735 whose execution can be triggered by another daemon---e.g., an FTP server
29736 started by @command{inetd} or a D-Bus service activated by
29737 @command{dbus-daemon}. Occasionally, a service does not map to a
29738 daemon. For instance, the ``account'' service collects user accounts
29739 and makes sure they exist when the system runs; the ``udev'' service
29740 collects device management rules and makes them available to the eudev
29741 daemon; the @file{/etc} service populates the @file{/etc} directory
29744 @cindex service extensions
29745 Guix system services are connected by @dfn{extensions}. For instance, the
29746 secure shell service @emph{extends} the Shepherd---the
29747 initialization system, running as PID@tie{}1---by giving it the command
29748 lines to start and stop the secure shell daemon (@pxref{Networking
29749 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
29750 service by passing it its @file{.service} specification, and extends the
29751 udev service by passing it device management rules (@pxref{Desktop
29752 Services, @code{upower-service}}); the Guix daemon service extends the
29753 Shepherd by passing it the command lines to start and stop the daemon,
29754 and extends the account service by passing it a list of required build
29755 user accounts (@pxref{Base Services}).
29757 All in all, services and their ``extends'' relations form a directed
29758 acyclic graph (DAG). If we represent services as boxes and extensions
29759 as arrows, a typical system might provide something like this:
29761 @image{images/service-graph,,5in,Typical service extension graph.}
29763 @cindex system service
29764 At the bottom, we see the @dfn{system service}, which produces the
29765 directory containing everything to run and boot the system, as returned
29766 by the @command{guix system build} command. @xref{Service Reference},
29767 to learn about the other service types shown here.
29768 @xref{system-extension-graph, the @command{guix system extension-graph}
29769 command}, for information on how to generate this representation for a
29770 particular operating system definition.
29772 @cindex service types
29773 Technically, developers can define @dfn{service types} to express these
29774 relations. There can be any number of services of a given type on the
29775 system---for instance, a system running two instances of the GNU secure
29776 shell server (lsh) has two instances of @code{lsh-service-type}, with
29777 different parameters.
29779 The following section describes the programming interface for service
29780 types and services.
29782 @node Service Types and Services
29783 @subsection Service Types and Services
29785 A @dfn{service type} is a node in the DAG described above. Let us start
29786 with a simple example, the service type for the Guix build daemon
29787 (@pxref{Invoking guix-daemon}):
29790 (define guix-service-type
29794 (list (service-extension shepherd-root-service-type guix-shepherd-service)
29795 (service-extension account-service-type guix-accounts)
29796 (service-extension activation-service-type guix-activation)))
29797 (default-value (guix-configuration))))
29801 It defines three things:
29805 A name, whose sole purpose is to make inspection and debugging easier.
29808 A list of @dfn{service extensions}, where each extension designates the
29809 target service type and a procedure that, given the parameters of the
29810 service, returns a list of objects to extend the service of that type.
29812 Every service type has at least one service extension. The only
29813 exception is the @dfn{boot service type}, which is the ultimate service.
29816 Optionally, a default value for instances of this type.
29819 In this example, @code{guix-service-type} extends three services:
29822 @item shepherd-root-service-type
29823 The @code{guix-shepherd-service} procedure defines how the Shepherd
29824 service is extended. Namely, it returns a @code{<shepherd-service>}
29825 object that defines how @command{guix-daemon} is started and stopped
29826 (@pxref{Shepherd Services}).
29828 @item account-service-type
29829 This extension for this service is computed by @code{guix-accounts},
29830 which returns a list of @code{user-group} and @code{user-account}
29831 objects representing the build user accounts (@pxref{Invoking
29834 @item activation-service-type
29835 Here @code{guix-activation} is a procedure that returns a gexp, which is
29836 a code snippet to run at ``activation time''---e.g., when the service is
29840 A service of this type is instantiated like this:
29843 (service guix-service-type
29844 (guix-configuration
29846 (use-substitutes? #f)))
29849 The second argument to the @code{service} form is a value representing
29850 the parameters of this specific service instance.
29851 @xref{guix-configuration-type, @code{guix-configuration}}, for
29852 information about the @code{guix-configuration} data type. When the
29853 value is omitted, the default value specified by
29854 @code{guix-service-type} is used:
29857 (service guix-service-type)
29860 @code{guix-service-type} is quite simple because it extends other
29861 services but is not extensible itself.
29863 @c @subsubsubsection Extensible Service Types
29865 The service type for an @emph{extensible} service looks like this:
29868 (define udev-service-type
29869 (service-type (name 'udev)
29871 (list (service-extension shepherd-root-service-type
29872 udev-shepherd-service)))
29874 (compose concatenate) ;concatenate the list of rules
29875 (extend (lambda (config rules)
29877 (($ <udev-configuration> udev initial-rules)
29878 (udev-configuration
29879 (udev udev) ;the udev package to use
29880 (rules (append initial-rules rules)))))))))
29883 This is the service type for the
29884 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
29885 management daemon}. Compared to the previous example, in addition to an
29886 extension of @code{shepherd-root-service-type}, we see two new fields:
29890 This is the procedure to @dfn{compose} the list of extensions to
29891 services of this type.
29893 Services can extend the udev service by passing it lists of rules; we
29894 compose those extensions simply by concatenating them.
29897 This procedure defines how the value of the service is @dfn{extended} with
29898 the composition of the extensions.
29900 Udev extensions are composed into a list of rules, but the udev service
29901 value is itself a @code{<udev-configuration>} record. So here, we
29902 extend that record by appending the list of rules it contains to the
29903 list of contributed rules.
29906 This is a string giving an overview of the service type. The string can
29907 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
29908 @command{guix system search} command searches these strings and displays
29909 them (@pxref{Invoking guix system}).
29912 There can be only one instance of an extensible service type such as
29913 @code{udev-service-type}. If there were more, the
29914 @code{service-extension} specifications would be ambiguous.
29916 Still here? The next section provides a reference of the programming
29917 interface for services.
29919 @node Service Reference
29920 @subsection Service Reference
29922 We have seen an overview of service types (@pxref{Service Types and
29923 Services}). This section provides a reference on how to manipulate
29924 services and service types. This interface is provided by the
29925 @code{(gnu services)} module.
29927 @deffn {Scheme Procedure} service @var{type} [@var{value}]
29928 Return a new service of @var{type}, a @code{<service-type>} object (see
29929 below). @var{value} can be any object; it represents the parameters of
29930 this particular service instance.
29932 When @var{value} is omitted, the default value specified by @var{type}
29933 is used; if @var{type} does not specify a default value, an error is
29936 For instance, this:
29939 (service openssh-service-type)
29943 is equivalent to this:
29946 (service openssh-service-type
29947 (openssh-configuration))
29950 In both cases the result is an instance of @code{openssh-service-type}
29951 with the default configuration.
29954 @deffn {Scheme Procedure} service? @var{obj}
29955 Return true if @var{obj} is a service.
29958 @deffn {Scheme Procedure} service-kind @var{service}
29959 Return the type of @var{service}---i.e., a @code{<service-type>} object.
29962 @deffn {Scheme Procedure} service-value @var{service}
29963 Return the value associated with @var{service}. It represents its
29967 Here is an example of how a service is created and manipulated:
29971 (service nginx-service-type
29972 (nginx-configuration
29974 (log-directory log-directory)
29975 (run-directory run-directory)
29976 (file config-file))))
29981 (eq? (service-kind s) nginx-service-type)
29985 The @code{modify-services} form provides a handy way to change the
29986 parameters of some of the services of a list such as
29987 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
29988 evaluates to a list of services. Of course, you could always use
29989 standard list combinators such as @code{map} and @code{fold} to do that
29990 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
29991 @code{modify-services} simply provides a more concise form for this
29994 @deffn {Scheme Syntax} modify-services @var{services} @
29995 (@var{type} @var{variable} => @var{body}) @dots{}
29997 Modify the services listed in @var{services} according to the given
29998 clauses. Each clause has the form:
30001 (@var{type} @var{variable} => @var{body})
30004 where @var{type} is a service type---e.g.,
30005 @code{guix-service-type}---and @var{variable} is an identifier that is
30006 bound within the @var{body} to the service parameters---e.g., a
30007 @code{guix-configuration} instance---of the original service of that
30010 The @var{body} should evaluate to the new service parameters, which will
30011 be used to configure the new service. This new service will replace the
30012 original in the resulting list. Because a service's service parameters
30013 are created using @code{define-record-type*}, you can write a succinct
30014 @var{body} that evaluates to the new service parameters by using the
30015 @code{inherit} feature that @code{define-record-type*} provides.
30017 @xref{Using the Configuration System}, for example usage.
30021 Next comes the programming interface for service types. This is
30022 something you want to know when writing new service definitions, but not
30023 necessarily when simply looking for ways to customize your
30024 @code{operating-system} declaration.
30026 @deftp {Data Type} service-type
30027 @cindex service type
30028 This is the representation of a @dfn{service type} (@pxref{Service Types
30033 This is a symbol, used only to simplify inspection and debugging.
30035 @item @code{extensions}
30036 A non-empty list of @code{<service-extension>} objects (see below).
30038 @item @code{compose} (default: @code{#f})
30039 If this is @code{#f}, then the service type denotes services that cannot
30040 be extended---i.e., services that do not receive ``values'' from other
30043 Otherwise, it must be a one-argument procedure. The procedure is called
30044 by @code{fold-services} and is passed a list of values collected from
30045 extensions. It may return any single value.
30047 @item @code{extend} (default: @code{#f})
30048 If this is @code{#f}, services of this type cannot be extended.
30050 Otherwise, it must be a two-argument procedure: @code{fold-services}
30051 calls it, passing it the initial value of the service as the first
30052 argument and the result of applying @code{compose} to the extension
30053 values as the second argument. It must return a value that is a valid
30054 parameter value for the service instance.
30056 @item @code{description}
30057 This is a string, possibly using Texinfo markup, describing in a couple
30058 of sentences what the service is about. This string allows users to
30059 find about the service through @command{guix system search}
30060 (@pxref{Invoking guix system}).
30062 @item @code{default-value} (default: @code{&no-default-value})
30063 The default value associated for instances of this service type. This
30064 allows users to use the @code{service} form without its second argument:
30067 (service @var{type})
30070 The returned service in this case has the default value specified by
30074 @xref{Service Types and Services}, for examples.
30077 @deffn {Scheme Procedure} service-extension @var{target-type} @
30079 Return a new extension for services of type @var{target-type}.
30080 @var{compute} must be a one-argument procedure: @code{fold-services}
30081 calls it, passing it the value associated with the service that provides
30082 the extension; it must return a valid value for the target service.
30085 @deffn {Scheme Procedure} service-extension? @var{obj}
30086 Return true if @var{obj} is a service extension.
30089 Occasionally, you might want to simply extend an existing service. This
30090 involves creating a new service type and specifying the extension of
30091 interest, which can be verbose; the @code{simple-service} procedure
30092 provides a shorthand for this.
30094 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
30095 Return a service that extends @var{target} with @var{value}. This works
30096 by creating a singleton service type @var{name}, of which the returned
30097 service is an instance.
30099 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
30103 (simple-service 'my-mcron-job mcron-service-type
30104 #~(job '(next-hour (3)) "guix gc -F 2G"))
30108 At the core of the service abstraction lies the @code{fold-services}
30109 procedure, which is responsible for ``compiling'' a list of services
30110 down to a single directory that contains everything needed to boot and
30111 run the system---the directory shown by the @command{guix system build}
30112 command (@pxref{Invoking guix system}). In essence, it propagates
30113 service extensions down the service graph, updating each node parameters
30114 on the way, until it reaches the root node.
30116 @deffn {Scheme Procedure} fold-services @var{services} @
30117 [#:target-type @var{system-service-type}]
30118 Fold @var{services} by propagating their extensions down to the root of
30119 type @var{target-type}; return the root service adjusted accordingly.
30122 Lastly, the @code{(gnu services)} module also defines several essential
30123 service types, some of which are listed below.
30125 @defvr {Scheme Variable} system-service-type
30126 This is the root of the service graph. It produces the system directory
30127 as returned by the @command{guix system build} command.
30130 @defvr {Scheme Variable} boot-service-type
30131 The type of the ``boot service'', which produces the @dfn{boot script}.
30132 The boot script is what the initial RAM disk runs when booting.
30135 @defvr {Scheme Variable} etc-service-type
30136 The type of the @file{/etc} service. This service is used to create
30137 files under @file{/etc} and can be extended by
30138 passing it name/file tuples such as:
30141 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
30144 In this example, the effect would be to add an @file{/etc/issue} file
30145 pointing to the given file.
30148 @defvr {Scheme Variable} setuid-program-service-type
30149 Type for the ``setuid-program service''. This service collects lists of
30150 executable file names, passed as gexps, and adds them to the set of
30151 setuid-root programs on the system (@pxref{Setuid Programs}).
30154 @defvr {Scheme Variable} profile-service-type
30155 Type of the service that populates the @dfn{system profile}---i.e., the
30156 programs under @file{/run/current-system/profile}. Other services can
30157 extend it by passing it lists of packages to add to the system profile.
30160 @cindex provenance tracking, of the operating system
30161 @anchor{provenance-service-type}
30162 @defvr {Scheme Variable} provenance-service-type
30163 This is the type of the service that records @dfn{provenance meta-data}
30164 in the system itself. It creates several files under
30165 @file{/run/current-system}:
30169 This is a ``channel file'' that can be passed to @command{guix pull -C}
30170 or @command{guix time-machine -C}, and which describes the channels used
30171 to build the system, if that information was available
30172 (@pxref{Channels}).
30174 @item configuration.scm
30175 This is the file that was passed as the value for this
30176 @code{provenance-service-type} service. By default, @command{guix
30177 system reconfigure} automatically passes the OS configuration file it
30178 received on the command line.
30181 This contains the same information as the two other files but in a
30182 format that is more readily processable.
30185 In general, these two pieces of information (channels and configuration
30186 file) are enough to reproduce the operating system ``from source''.
30189 This information is necessary to rebuild your operating system, but it
30190 is not always sufficient. In particular, @file{configuration.scm}
30191 itself is insufficient if it is not self-contained---if it refers to
30192 external Guile modules or to extra files. If you want
30193 @file{configuration.scm} to be self-contained, we recommend that modules
30194 or files it refers to be part of a channel.
30196 Besides, provenance meta-data is ``silent'' in the sense that it does
30197 not change the bits contained in your system, @emph{except for the
30198 meta-data bits themselves}. Two different OS configurations or sets of
30199 channels can lead to the same system, bit-for-bit; when
30200 @code{provenance-service-type} is used, these two systems will have
30201 different meta-data and thus different store file names, which makes
30202 comparison less trivial.
30205 This service is automatically added to your operating system
30206 configuration when you use @command{guix system reconfigure},
30207 @command{guix system init}, or @command{guix deploy}.
30210 @node Shepherd Services
30211 @subsection Shepherd Services
30213 @cindex shepherd services
30215 @cindex init system
30216 The @code{(gnu services shepherd)} module provides a way to define
30217 services managed by the GNU@tie{}Shepherd, which is the
30218 initialization system---the first process that is started when the
30219 system boots, also known as PID@tie{}1
30220 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
30222 Services in the Shepherd can depend on each other. For instance, the
30223 SSH daemon may need to be started after the syslog daemon has been
30224 started, which in turn can only happen once all the file systems have
30225 been mounted. The simple operating system defined earlier (@pxref{Using
30226 the Configuration System}) results in a service graph like this:
30228 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
30230 You can actually generate such a graph for any operating system
30231 definition using the @command{guix system shepherd-graph} command
30232 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
30234 The @code{%shepherd-root-service} is a service object representing
30235 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
30236 by passing it lists of @code{<shepherd-service>} objects.
30238 @deftp {Data Type} shepherd-service
30239 The data type representing a service managed by the Shepherd.
30242 @item @code{provision}
30243 This is a list of symbols denoting what the service provides.
30245 These are the names that may be passed to @command{herd start},
30246 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
30247 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
30248 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
30250 @item @code{requirement} (default: @code{'()})
30251 List of symbols denoting the Shepherd services this one depends on.
30253 @cindex one-shot services, for the Shepherd
30254 @item @code{one-shot?} (default: @code{#f})
30255 Whether this service is @dfn{one-shot}. One-shot services stop immediately
30256 after their @code{start} action has completed. @xref{Slots of services,,,
30257 shepherd, The GNU Shepherd Manual}, for more info.
30259 @item @code{respawn?} (default: @code{#t})
30260 Whether to restart the service when it stops, for instance when the
30261 underlying process dies.
30264 @itemx @code{stop} (default: @code{#~(const #f)})
30265 The @code{start} and @code{stop} fields refer to the Shepherd's
30266 facilities to start and stop processes (@pxref{Service De- and
30267 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
30268 G-expressions that get expanded in the Shepherd configuration file
30269 (@pxref{G-Expressions}).
30271 @item @code{actions} (default: @code{'()})
30272 @cindex actions, of Shepherd services
30273 This is a list of @code{shepherd-action} objects (see below) defining
30274 @dfn{actions} supported by the service, in addition to the standard
30275 @code{start} and @code{stop} actions. Actions listed here become available as
30276 @command{herd} sub-commands:
30279 herd @var{action} @var{service} [@var{arguments}@dots{}]
30282 @item @code{auto-start?} (default: @code{#t})
30283 Whether this service should be started automatically by the Shepherd. If it
30284 is @code{#f} the service has to be started manually with @code{herd start}.
30286 @item @code{documentation}
30287 A documentation string, as shown when running:
30290 herd doc @var{service-name}
30293 where @var{service-name} is one of the symbols in @code{provision}
30294 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
30296 @item @code{modules} (default: @code{%default-modules})
30297 This is the list of modules that must be in scope when @code{start} and
30298 @code{stop} are evaluated.
30303 @deftp {Data Type} shepherd-action
30304 This is the data type that defines additional actions implemented by a
30305 Shepherd service (see above).
30309 Symbol naming the action.
30311 @item documentation
30312 This is a documentation string for the action. It can be viewed by running:
30315 herd doc @var{service} action @var{action}
30319 This should be a gexp that evaluates to a procedure of at least one argument,
30320 which is the ``running value'' of the service (@pxref{Slots of services,,,
30321 shepherd, The GNU Shepherd Manual}).
30324 The following example defines an action called @code{say-hello} that kindly
30330 (documentation "Say hi!")
30331 (procedure #~(lambda (running . args)
30332 (format #t "Hello, friend! arguments: ~s\n"
30337 Assuming this action is added to the @code{example} service, then you can do:
30340 # herd say-hello example
30341 Hello, friend! arguments: ()
30342 # herd say-hello example a b c
30343 Hello, friend! arguments: ("a" "b" "c")
30346 This, as you can see, is a fairly sophisticated way to say hello.
30347 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
30351 @defvr {Scheme Variable} shepherd-root-service-type
30352 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
30354 This is the service type that extensions target when they want to create
30355 shepherd services (@pxref{Service Types and Services}, for an example).
30356 Each extension must pass a list of @code{<shepherd-service>}.
30359 @defvr {Scheme Variable} %shepherd-root-service
30360 This service represents PID@tie{}1.
30364 @node Documentation
30365 @chapter Documentation
30367 @cindex documentation, searching for
30368 @cindex searching for documentation
30369 @cindex Info, documentation format
30371 @cindex manual pages
30372 In most cases packages installed with Guix come with documentation.
30373 There are two main documentation formats: ``Info'', a browseable
30374 hypertext format used for GNU software, and ``manual pages'' (or ``man
30375 pages''), the linear documentation format traditionally found on Unix.
30376 Info manuals are accessed with the @command{info} command or with Emacs,
30377 and man pages are accessed using @command{man}.
30379 You can look for documentation of software installed on your system by
30380 keyword. For example, the following command searches for information
30381 about ``TLS'' in Info manuals:
30385 "(emacs)Network Security" -- STARTTLS
30386 "(emacs)Network Security" -- TLS
30387 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
30388 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
30393 The command below searches for the same keyword in man pages:
30397 SSL (7) - OpenSSL SSL/TLS library
30398 certtool (1) - GnuTLS certificate tool
30402 These searches are purely local to your computer so you have the
30403 guarantee that documentation you find corresponds to what you have
30404 actually installed, you can access it off-line, and your privacy is
30407 Once you have these results, you can view the relevant documentation by
30411 $ info "(gnutls)Core TLS API"
30421 Info manuals contain sections and indices as well as hyperlinks like
30422 those found in Web pages. The @command{info} reader (@pxref{Top, Info
30423 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
30424 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
30425 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
30426 Introduction}, for an introduction to Info navigation.
30428 @node Installing Debugging Files
30429 @chapter Installing Debugging Files
30431 @cindex debugging files
30432 Program binaries, as produced by the GCC compilers for instance, are
30433 typically written in the ELF format, with a section containing
30434 @dfn{debugging information}. Debugging information is what allows the
30435 debugger, GDB, to map binary code to source code; it is required to
30436 debug a compiled program in good conditions.
30438 The problem with debugging information is that is takes up a fair amount
30439 of disk space. For example, debugging information for the GNU C Library
30440 weighs in at more than 60 MiB. Thus, as a user, keeping all the
30441 debugging info of all the installed programs is usually not an option.
30442 Yet, space savings should not come at the cost of an impediment to
30443 debugging---especially in the GNU system, which should make it easier
30444 for users to exert their computing freedom (@pxref{GNU Distribution}).
30446 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
30447 mechanism that allows users to get the best of both worlds: debugging
30448 information can be stripped from the binaries and stored in separate
30449 files. GDB is then able to load debugging information from those files,
30450 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
30453 The GNU distribution takes advantage of this by storing debugging
30454 information in the @code{lib/debug} sub-directory of a separate package
30455 output unimaginatively called @code{debug} (@pxref{Packages with
30456 Multiple Outputs}). Users can choose to install the @code{debug} output
30457 of a package when they need it. For instance, the following command
30458 installs the debugging information for the GNU C Library and for GNU
30462 guix install glibc:debug guile:debug
30465 GDB must then be told to look for debug files in the user's profile, by
30466 setting the @code{debug-file-directory} variable (consider setting it
30467 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
30471 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
30474 From there on, GDB will pick up debugging information from the
30475 @file{.debug} files under @file{~/.guix-profile/lib/debug}.
30477 In addition, you will most likely want GDB to be able to show the source
30478 code being debugged. To do that, you will have to unpack the source
30479 code of the package of interest (obtained with @code{guix build
30480 --source}, @pxref{Invoking guix build}), and to point GDB to that source
30481 directory using the @code{directory} command (@pxref{Source Path,
30482 @code{directory},, gdb, Debugging with GDB}).
30484 @c XXX: keep me up-to-date
30485 The @code{debug} output mechanism in Guix is implemented by the
30486 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
30487 opt-in---debugging information is available only for the packages
30488 with definitions explicitly declaring a @code{debug} output. This may be
30489 changed to opt-out in the future if our build farm servers can handle
30490 the load. To check whether a package has a @code{debug} output, use
30491 @command{guix package --list-available} (@pxref{Invoking guix package}).
30494 @node Security Updates
30495 @chapter Security Updates
30497 @cindex security updates
30498 @cindex security vulnerabilities
30499 Occasionally, important security vulnerabilities are discovered in software
30500 packages and must be patched. Guix developers try hard to keep track of
30501 known vulnerabilities and to apply fixes as soon as possible in the
30502 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
30503 containing only security updates). The @command{guix lint} tool helps
30504 developers find out about vulnerable versions of software packages in the
30509 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
30510 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
30511 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
30515 @xref{Invoking guix lint}, for more information.
30517 Guix follows a functional
30518 package management discipline (@pxref{Introduction}), which implies
30519 that, when a package is changed, @emph{every package that depends on it}
30520 must be rebuilt. This can significantly slow down the deployment of
30521 fixes in core packages such as libc or Bash, since basically the whole
30522 distribution would need to be rebuilt. Using pre-built binaries helps
30523 (@pxref{Substitutes}), but deployment may still take more time than
30527 To address this, Guix implements @dfn{grafts}, a mechanism that allows
30528 for fast deployment of critical updates without the costs associated
30529 with a whole-distribution rebuild. The idea is to rebuild only the
30530 package that needs to be patched, and then to ``graft'' it onto packages
30531 explicitly installed by the user and that were previously referring to
30532 the original package. The cost of grafting is typically very low, and
30533 order of magnitudes lower than a full rebuild of the dependency chain.
30535 @cindex replacements of packages, for grafts
30536 For instance, suppose a security update needs to be applied to Bash.
30537 Guix developers will provide a package definition for the ``fixed''
30538 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
30539 Packages}). Then, the original package definition is augmented with a
30540 @code{replacement} field pointing to the package containing the bug fix:
30547 (replacement bash-fixed)))
30550 From there on, any package depending directly or indirectly on Bash---as
30551 reported by @command{guix gc --requisites} (@pxref{Invoking guix
30552 gc})---that is installed is automatically ``rewritten'' to refer to
30553 @code{bash-fixed} instead of @code{bash}. This grafting process takes
30554 time proportional to the size of the package, usually less than a
30555 minute for an ``average'' package on a recent machine. Grafting is
30556 recursive: when an indirect dependency requires grafting, then grafting
30557 ``propagates'' up to the package that the user is installing.
30559 Currently, the length of the name and version of the graft and that of
30560 the package it replaces (@code{bash-fixed} and @code{bash} in the example
30561 above) must be equal. This restriction mostly comes from the fact that
30562 grafting works by patching files, including binary files, directly.
30563 Other restrictions may apply: for instance, when adding a graft to a
30564 package providing a shared library, the original shared library and its
30565 replacement must have the same @code{SONAME} and be binary-compatible.
30567 The @option{--no-grafts} command-line option allows you to forcefully
30568 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
30572 guix build bash --no-grafts
30576 returns the store file name of the original Bash, whereas:
30583 returns the store file name of the ``fixed'', replacement Bash. This
30584 allows you to distinguish between the two variants of Bash.
30586 To verify which Bash your whole profile refers to, you can run
30587 (@pxref{Invoking guix gc}):
30590 guix gc -R `readlink -f ~/.guix-profile` | grep bash
30594 @dots{} and compare the store file names that you get with those above.
30595 Likewise for a complete Guix system generation:
30598 guix gc -R `guix system build my-config.scm` | grep bash
30601 Lastly, to check which Bash running processes are using, you can use the
30602 @command{lsof} command:
30605 lsof | grep /gnu/store/.*bash
30609 @node Bootstrapping
30610 @chapter Bootstrapping
30612 @c Adapted from the ELS 2013 paper.
30614 @cindex bootstrapping
30616 Bootstrapping in our context refers to how the distribution gets built
30617 ``from nothing''. Remember that the build environment of a derivation
30618 contains nothing but its declared inputs (@pxref{Introduction}). So
30619 there's an obvious chicken-and-egg problem: how does the first package
30620 get built? How does the first compiler get compiled? Note that this is
30621 a question of interest only to the curious hacker, not to the regular
30622 user, so you can shamelessly skip this section if you consider yourself
30623 a ``regular user''.
30625 @cindex bootstrap binaries
30626 The GNU system is primarily made of C code, with libc at its core. The
30627 GNU build system itself assumes the availability of a Bourne shell and
30628 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
30629 `grep'. Furthermore, build programs---programs that run
30630 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
30631 (@pxref{Derivations}). Consequently, to be able to build anything at
30632 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
30633 Binutils, libc, and the other packages mentioned above---the
30634 @dfn{bootstrap binaries}.
30636 These bootstrap binaries are ``taken for granted'', though we can also
30637 re-create them if needed (@pxref{Preparing to Use the Bootstrap
30641 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
30642 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
30645 @node Reduced Binary Seed Bootstrap
30646 @section The Reduced Binary Seed Bootstrap
30648 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
30649 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
30650 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
30651 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
30652 ``taken for granted.''
30654 Taking the bootstrap binaries for granted means that we consider them to
30655 be a correct and trustworthy ``seed'' for building the complete system.
30656 Therein lies a problem: the combined size of these bootstrap binaries is
30657 about 250MB (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing
30658 or even inspecting these is next to impossible.
30660 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a
30661 ``Reduced Binary Seed'' bootstrap @footnote{We would like to say: ``Full
30662 Source Bootstrap'' and while we are working towards that goal it would
30663 be hyperbole to use that term for what we do now.}.
30665 The Reduced Binary Seed bootstrap removes the most critical tools---from a
30666 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
30667 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
30668 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
30669 written in Scheme and the Mes C Library, built for TinyCC and for GCC).
30671 Using these new binary seeds the ``missing'' Binutils, GCC, and the GNU
30672 C Library are built from source. From here on the more traditional
30673 bootstrap process resumes. This approach has reduced the bootstrap
30674 binaries in size to about 145MB in Guix v1.1.
30676 The next step that Guix has taken is to replace the shell and all its
30677 utilities with implementations in Guile Scheme, the @emph{Scheme-only
30678 bootstrap}. Gash (@pxref{Gash,,, gash, The Gash manual}) is a
30679 POSIX-compatible shell that replaces Bash, and it comes with Gash Utils
30680 which has minimalist replacements for Awk, the GNU Core Utilities, Grep,
30681 Gzip, Sed, and Tar. The rest of the bootstrap binary seeds that were
30682 removed are now built from source.
30684 Building the GNU System from source is currently only possibly by adding
30685 some historical GNU packages as intermediate steps@footnote{Packages
30686 such as @code{gcc-2.95.3}, @code{binutils-2.14}, @code{glibc-2.2.5},
30687 @code{gzip-1.2.4}, @code{tar-1.22}, and some others. For details, see
30688 @file{gnu/packages/commencement.scm}.}. As Gash and Gash Utils mature,
30689 and GNU packages become more bootstrappable again (e.g., new releases of
30690 GNU Sed will also ship as gzipped tarballs again, as alternative to the
30691 hard to bootstrap @code{xz}-compression), this set of added packages can
30692 hopefully be reduced again.
30694 The graph below shows the resulting dependency graph for
30695 @code{gcc-core-mesboot0}, the bootstrap compiler used for the
30696 traditional bootstrap of the rest of the Guix System.
30698 @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
30699 @image{images/gcc-core-mesboot0-graph,6in,,Dependency graph of gcc-core-mesboot0}
30701 The only significant binary bootstrap seeds that remain@footnote{
30702 Ignoring the 68KB @code{mescc-tools}; that will be removed later,
30703 together with @code{mes}.} are a Scheme intepreter and a Scheme
30704 compiler: GNU Mes and GNU Guile@footnote{Not shown in this graph are the
30705 static binaries for @file{bash}, @code{tar}, and @code{xz} that are used
30706 to get Guile running.}.
30708 This further reduction has brought down the size of the binary seed to
30709 about 60MB for @code{i686-linux} and @code{x86_64-linux}.
30711 Work is ongoing to remove all binary blobs from our free software
30712 bootstrap stack, working towards a Full Source Bootstrap. Also ongoing
30713 is work to bring these bootstraps to the @code{arm-linux} and
30714 @code{aarch64-linux} architectures and to the Hurd.
30716 If you are interested, join us on @samp{#bootstrappable} on the Freenode
30717 IRC network or discuss on @email{bug-mes@@gnu.org} or
30718 @email{gash-devel@@nongnu.org}.
30720 @node Preparing to Use the Bootstrap Binaries
30721 @section Preparing to Use the Bootstrap Binaries
30723 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
30724 @c large image, it's hard to scroll. Oh well.
30725 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
30727 The figure above shows the very beginning of the dependency graph of the
30728 distribution, corresponding to the package definitions of the @code{(gnu
30729 packages bootstrap)} module. A similar figure can be generated with
30730 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
30733 guix graph -t derivation \
30734 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
30735 | dot -Tps > gcc.ps
30738 or, for the further Reduced Binary Seed bootstrap
30741 guix graph -t derivation \
30742 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
30743 | dot -Tps > mes.ps
30746 At this level of detail, things are
30747 slightly complex. First, Guile itself consists of an ELF executable,
30748 along with many source and compiled Scheme files that are dynamically
30749 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
30750 tarball shown in this graph. This tarball is part of Guix's ``source''
30751 distribution, and gets inserted into the store with @code{add-to-store}
30752 (@pxref{The Store}).
30754 But how do we write a derivation that unpacks this tarball and adds it
30755 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
30756 derivation---the first one that gets built---uses @code{bash} as its
30757 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
30758 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
30759 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
30760 the Guix source distribution, whose sole purpose is to allow the Guile
30761 tarball to be unpacked.
30763 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
30764 Guile that can be used to run subsequent build programs. Its first task
30765 is to download tarballs containing the other pre-built binaries---this
30766 is what the @file{.tar.xz.drv} derivations do. Guix modules such as
30767 @code{ftp-client.scm} are used for this purpose. The
30768 @code{module-import.drv} derivations import those modules in a directory
30769 in the store, using the original layout. The
30770 @code{module-import-compiled.drv} derivations compile those modules, and
30771 write them in an output directory with the right layout. This
30772 corresponds to the @code{#:modules} argument of
30773 @code{build-expression->derivation} (@pxref{Derivations}).
30775 Finally, the various tarballs are unpacked by the derivations
30776 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
30777 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
30778 point we have a working C tool chain.
30780 @unnumberedsec Building the Build Tools
30782 Bootstrapping is complete when we have a full tool chain that does not
30783 depend on the pre-built bootstrap tools discussed above. This
30784 no-dependency requirement is verified by checking whether the files of
30785 the final tool chain contain references to the @file{/gnu/store}
30786 directories of the bootstrap inputs. The process that leads to this
30787 ``final'' tool chain is described by the package definitions found in
30788 the @code{(gnu packages commencement)} module.
30790 The @command{guix graph} command allows us to ``zoom out'' compared to
30791 the graph above, by looking at the level of package objects instead of
30792 individual derivations---remember that a package may translate to
30793 several derivations, typically one derivation to download its source,
30794 one to build the Guile modules it needs, and one to actually build the
30795 package from source. The command:
30798 guix graph -t bag \
30799 -e '(@@@@ (gnu packages commencement)
30800 glibc-final-with-bootstrap-bash)' | xdot -
30804 displays the dependency graph leading to the ``final'' C
30805 library@footnote{You may notice the @code{glibc-intermediate} label,
30806 suggesting that it is not @emph{quite} final, but as a good
30807 approximation, we will consider it final.}, depicted below.
30809 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
30811 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
30812 The first tool that gets built with the bootstrap binaries is
30813 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
30814 for all the following packages. From there Findutils and Diffutils get
30817 Then come the first-stage Binutils and GCC, built as pseudo cross
30818 tools---i.e., with @option{--target} equal to @option{--host}. They are
30819 used to build libc. Thanks to this cross-build trick, this libc is
30820 guaranteed not to hold any reference to the initial tool chain.
30822 From there the final Binutils and GCC (not shown above) are built. GCC
30823 uses @command{ld} from the final Binutils, and links programs against
30824 the just-built libc. This tool chain is used to build the other
30825 packages used by Guix and by the GNU Build System: Guile, Bash,
30828 And voilà! At this point we have the complete set of build tools that
30829 the GNU Build System expects. These are in the @code{%final-inputs}
30830 variable of the @code{(gnu packages commencement)} module, and are
30831 implicitly used by any package that uses @code{gnu-build-system}
30832 (@pxref{Build Systems, @code{gnu-build-system}}).
30835 @unnumberedsec Building the Bootstrap Binaries
30837 @cindex bootstrap binaries
30838 Because the final tool chain does not depend on the bootstrap binaries,
30839 those rarely need to be updated. Nevertheless, it is useful to have an
30840 automated way to produce them, should an update occur, and this is what
30841 the @code{(gnu packages make-bootstrap)} module provides.
30843 The following command builds the tarballs containing the bootstrap binaries
30844 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
30845 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
30846 and Guile, and a tarball containing a mixture of Coreutils and other basic
30847 command-line tools):
30850 guix build bootstrap-tarballs
30853 The generated tarballs are those that should be referred to in the
30854 @code{(gnu packages bootstrap)} module mentioned at the beginning of
30857 Still here? Then perhaps by now you've started to wonder: when do we
30858 reach a fixed point? That is an interesting question! The answer is
30859 unknown, but if you would like to investigate further (and have
30860 significant computational and storage resources to do so), then let us
30863 @unnumberedsec Reducing the Set of Bootstrap Binaries
30865 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
30866 binary code! Why is that a problem? It's a problem because these big chunks
30867 of binary code are practically non-auditable, which makes it hard to establish
30868 what source code produced them. Every unauditable binary also leaves us
30869 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
30870 paper @emph{Reflections on Trusting Trust}.
30872 This is mitigated by the fact that our bootstrap binaries were generated
30873 from an earlier Guix revision. Nevertheless it lacks the level of
30874 transparency that we get in the rest of the package dependency graph,
30875 where Guix always gives us a source-to-binary mapping. Thus, our goal
30876 is to reduce the set of bootstrap binaries to the bare minimum.
30878 The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
30879 on-going projects to do that. One of these is about replacing the
30880 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
30881 of increasing complexity, which could be built from source starting from
30882 a simple and auditable assembler.
30884 Our first major achievement is the replacement of of GCC, the GNU C Library
30885 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
30886 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
30887 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
30888 bootstrapped yet and thus we inject them as binary seeds. We call this the
30889 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
30890 binaries! Also, it has eliminated the C compiler binary; i686-linux and
30891 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
30893 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
30894 also looking at any other bootstrap binaries. Your help is welcome!
30897 @chapter Porting to a New Platform
30899 As discussed above, the GNU distribution is self-contained, and
30900 self-containment is achieved by relying on pre-built ``bootstrap
30901 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
30902 operating system kernel, CPU architecture, and application binary
30903 interface (ABI). Thus, to port the distribution to a platform that is
30904 not yet supported, one must build those bootstrap binaries, and update
30905 the @code{(gnu packages bootstrap)} module to use them on that platform.
30907 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
30908 When everything goes well, and assuming the GNU tool chain supports the
30909 target platform, this can be as simple as running a command like this
30913 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
30916 For this to work, the @code{glibc-dynamic-linker} procedure in
30917 @code{(gnu packages bootstrap)} must be augmented to return the right
30918 file name for libc's dynamic linker on that platform; likewise,
30919 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
30920 taught about the new platform.
30922 Once these are built, the @code{(gnu packages bootstrap)} module needs
30923 to be updated to refer to these binaries on the target platform. That
30924 is, the hashes and URLs of the bootstrap tarballs for the new platform
30925 must be added alongside those of the currently supported platforms. The
30926 bootstrap Guile tarball is treated specially: it is expected to be
30927 available locally, and @file{gnu/local.mk} has rules to download it for
30928 the supported architectures; a rule for the new platform must be added
30931 In practice, there may be some complications. First, it may be that the
30932 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
30933 above) is not recognized by all the GNU tools. Typically, glibc
30934 recognizes some of these, whereas GCC uses an extra @option{--with-abi}
30935 configure flag (see @code{gcc.scm} for examples of how to handle this).
30936 Second, some of the required packages could fail to build for that
30937 platform. Lastly, the generated binaries could be broken for some
30940 @c *********************************************************************
30941 @include contributing.texi
30943 @c *********************************************************************
30944 @node Acknowledgments
30945 @chapter Acknowledgments
30947 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
30948 which was designed and
30949 implemented by Eelco Dolstra, with contributions from other people (see
30950 the @file{nix/AUTHORS} file in Guix). Nix pioneered functional package
30951 management, and promoted unprecedented features, such as transactional
30952 package upgrades and rollbacks, per-user profiles, and referentially
30953 transparent build processes. Without this work, Guix would not exist.
30955 The Nix-based software distributions, Nixpkgs and NixOS, have also been
30956 an inspiration for Guix.
30958 GNU@tie{}Guix itself is a collective work with contributions from a
30959 number of people. See the @file{AUTHORS} file in Guix for more
30960 information on these fine people. The @file{THANKS} file lists people
30961 who have helped by reporting bugs, taking care of the infrastructure,
30962 providing artwork and themes, making suggestions, and more---thank you!
30965 @c *********************************************************************
30966 @node GNU Free Documentation License
30967 @appendix GNU Free Documentation License
30968 @cindex license, GNU Free Documentation License
30969 @include fdl-1.3.texi
30971 @c *********************************************************************
30972 @node Concept Index
30973 @unnumbered Concept Index
30976 @node Programming Index
30977 @unnumbered Programming Index
30978 @syncodeindex tp fn
30979 @syncodeindex vr fn
30984 @c Local Variables:
30985 @c ispell-local-dictionary: "american";