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 * Package Management:: Package installation, upgrade, etc.
148 * Development:: Guix-aided software development.
149 * Programming Interface:: Using Guix in Scheme.
150 * Utilities:: Package management commands.
151 * System Configuration:: Configuring the operating system.
152 * Documentation:: Browsing software user manuals.
153 * Installing Debugging Files:: Feeding the debugger.
154 * Security Updates:: Deploying security fixes quickly.
155 * Bootstrapping:: GNU/Linux built from scratch.
156 * Porting:: Targeting another platform or kernel.
157 * Contributing:: Your help needed!
159 * Acknowledgments:: Thanks!
160 * GNU Free Documentation License:: The license of this manual.
161 * Concept Index:: Concepts.
162 * Programming Index:: Data types, functions, and variables.
165 --- The Detailed Node Listing ---
169 * Managing Software the Guix Way:: What's special.
170 * GNU Distribution:: The packages and tools.
174 * Binary Installation:: Getting Guix running in no time!
175 * Requirements:: Software needed to build and run Guix.
176 * Running the Test Suite:: Testing Guix.
177 * Setting Up the Daemon:: Preparing the build daemon's environment.
178 * Invoking guix-daemon:: Running the build daemon.
179 * Application Setup:: Application-specific setup.
181 Setting Up the Daemon
183 * Build Environment Setup:: Preparing the isolated build environment.
184 * Daemon Offload Setup:: Offloading builds to remote machines.
185 * SELinux Support:: Using an SELinux policy for the daemon.
189 * Limitations:: What you can expect.
190 * Hardware Considerations:: Supported hardware.
191 * USB Stick and DVD Installation:: Preparing the installation medium.
192 * Preparing for Installation:: Networking, partitioning, etc.
193 * Guided Graphical Installation:: Easy graphical installation.
194 * Manual Installation:: Manual installation for wizards.
195 * After System Installation:: When installation succeeded.
196 * Installing Guix in a VM:: Guix System playground.
197 * Building the Installation Image:: How this comes to be.
201 * Keyboard Layout and Networking and Partitioning:: Initial setup.
202 * Proceeding with the Installation:: Installing.
206 * Features:: How Guix will make your life brighter.
207 * Invoking guix package:: Package installation, removal, etc.
208 * Substitutes:: Downloading pre-built binaries.
209 * Packages with Multiple Outputs:: Single source package, multiple outputs.
210 * Invoking guix gc:: Running the garbage collector.
211 * Invoking guix pull:: Fetching the latest Guix and distribution.
212 * Channels:: Customizing the package collection.
213 * Invoking guix time-machine:: Running an older revision of Guix.
214 * Inferiors:: Interacting with another revision of Guix.
215 * Invoking guix describe:: Display information about your Guix revision.
216 * Invoking guix archive:: Exporting and importing store files.
220 * Official Substitute Server:: One particular source of substitutes.
221 * Substitute Server Authorization:: How to enable or disable substitutes.
222 * Substitute Authentication:: How Guix verifies substitutes.
223 * Proxy Settings:: How to get substitutes via proxy.
224 * Substitution Failure:: What happens when substitution fails.
225 * On Trusting Binaries:: How can you trust that binary blob?
229 * Invoking guix environment:: Setting up development environments.
230 * Invoking guix pack:: Creating software bundles.
231 * The GCC toolchain:: Working with languages supported by GCC.
233 Programming Interface
235 * Package Modules:: Packages from the programmer's viewpoint.
236 * Defining Packages:: Defining new packages.
237 * Build Systems:: Specifying how packages are built.
238 * The Store:: Manipulating the package store.
239 * Derivations:: Low-level interface to package derivations.
240 * The Store Monad:: Purely functional interface to the store.
241 * G-Expressions:: Manipulating build expressions.
242 * Invoking guix repl:: Programming Guix in Guile
246 * package Reference:: The package data type.
247 * origin Reference:: The origin data type.
251 * Invoking guix build:: Building packages from the command line.
252 * Invoking guix edit:: Editing package definitions.
253 * Invoking guix download:: Downloading a file and printing its hash.
254 * Invoking guix hash:: Computing the cryptographic hash of a file.
255 * Invoking guix import:: Importing package definitions.
256 * Invoking guix refresh:: Updating package definitions.
257 * Invoking guix lint:: Finding errors in package definitions.
258 * Invoking guix size:: Profiling disk usage.
259 * Invoking guix graph:: Visualizing the graph of packages.
260 * Invoking guix publish:: Sharing substitutes.
261 * Invoking guix challenge:: Challenging substitute servers.
262 * Invoking guix copy:: Copying to and from a remote store.
263 * Invoking guix container:: Process isolation.
264 * Invoking guix weather:: Assessing substitute availability.
265 * Invoking guix processes:: Listing client processes.
267 Invoking @command{guix build}
269 * Common Build Options:: Build options for most commands.
270 * Package Transformation Options:: Creating variants of packages.
271 * Additional Build Options:: Options specific to 'guix build'.
272 * Debugging Build Failures:: Real life packaging experience.
276 * Using the Configuration System:: Customizing your GNU system.
277 * operating-system Reference:: Detail of operating-system declarations.
278 * File Systems:: Configuring file system mounts.
279 * Mapped Devices:: Block device extra processing.
280 * User Accounts:: Specifying user accounts.
281 * Keyboard Layout:: How the system interprets key strokes.
282 * Locales:: Language and cultural convention settings.
283 * Services:: Specifying system services.
284 * Setuid Programs:: Programs running with root privileges.
285 * X.509 Certificates:: Authenticating HTTPS servers.
286 * Name Service Switch:: Configuring libc's name service switch.
287 * Initial RAM Disk:: Linux-Libre bootstrapping.
288 * Bootloader Configuration:: Configuring the boot loader.
289 * Invoking guix system:: Instantiating a system configuration.
290 * Invoking guix deploy:: Deploying a system configuration to a remote host.
291 * Running Guix in a VM:: How to run Guix System in a virtual machine.
292 * Defining Services:: Adding new service definitions.
296 * Base Services:: Essential system services.
297 * Scheduled Job Execution:: The mcron service.
298 * Log Rotation:: The rottlog service.
299 * Networking Services:: Network setup, SSH daemon, etc.
300 * X Window:: Graphical display.
301 * Printing Services:: Local and remote printer support.
302 * Desktop Services:: D-Bus and desktop services.
303 * Sound Services:: ALSA and Pulseaudio services.
304 * Database Services:: SQL databases, key-value stores, etc.
305 * Mail Services:: IMAP, POP3, SMTP, and all that.
306 * Messaging Services:: Messaging services.
307 * Telephony Services:: Telephony services.
308 * Monitoring Services:: Monitoring services.
309 * Kerberos Services:: Kerberos services.
310 * Web Services:: Web servers.
311 * Certificate Services:: TLS certificates via Let's Encrypt.
312 * DNS Services:: DNS daemons.
313 * VPN Services:: VPN daemons.
314 * Network File System:: NFS related services.
315 * Continuous Integration:: The Cuirass service.
316 * Power Management Services:: Extending battery life.
317 * Audio Services:: The MPD.
318 * Virtualization Services:: Virtualization services.
319 * Version Control Services:: Providing remote access to Git repositories.
320 * Game Services:: Game servers.
321 * PAM Mount Service:: Service to mount volumes when logging in.
322 * Guix Services:: Services relating specifically to Guix.
323 * Linux Services:: Services tied to the Linux kernel.
324 * Hurd Services:: Services specific to a Hurd System.
325 * Miscellaneous Services:: Other services.
329 * Service Composition:: The model for composing services.
330 * Service Types and Services:: Types and services.
331 * Service Reference:: API reference.
332 * Shepherd Services:: A particular type of service.
337 @c *********************************************************************
339 @chapter Introduction
342 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
343 using the international phonetic alphabet (IPA).} is a package
344 management tool for and distribution of the GNU system.
345 Guix makes it easy for unprivileged
346 users to install, upgrade, or remove software packages, to roll back to a
347 previous package set, to build packages from source, and generally
348 assists with the creation and maintenance of software environments.
351 @cindex GuixSD, now Guix System
352 @cindex Guix System Distribution, now Guix System
353 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
354 complements the available tools without interference (@pxref{Installation}),
355 or you can use it as a standalone operating system distribution,
356 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
357 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
358 group everything under the ``Guix'' banner since, after all, Guix System is
359 readily available through the @command{guix system} command, even if you're
360 using a different distro underneath!}. @xref{GNU Distribution}.
363 * Managing Software the Guix Way:: What's special.
364 * GNU Distribution:: The packages and tools.
367 @node Managing Software the Guix Way
368 @section Managing Software the Guix Way
370 @cindex user interfaces
371 Guix provides a command-line package management interface
372 (@pxref{Package Management}), tools to help with software development
373 (@pxref{Development}), command-line utilities for more advanced usage,
374 (@pxref{Utilities}), as well as Scheme programming interfaces
375 (@pxref{Programming Interface}).
377 Its @dfn{build daemon} is responsible for building packages on behalf of
378 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
379 binaries from authorized sources (@pxref{Substitutes}).
381 @cindex extensibility of the distribution
382 @cindex customization, of packages
383 Guix includes package definitions for many GNU and non-GNU packages, all
384 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
385 user's computing freedom}. It is @emph{extensible}: users can write
386 their own package definitions (@pxref{Defining Packages}) and make them
387 available as independent package modules (@pxref{Package Modules}). It
388 is also @emph{customizable}: users can @emph{derive} specialized package
389 definitions from existing ones, including from the command line
390 (@pxref{Package Transformation Options}).
392 @cindex functional package management
394 Under the hood, Guix implements the @dfn{functional package management}
395 discipline pioneered by Nix (@pxref{Acknowledgments}).
396 In Guix, the package build and installation process is seen
397 as a @emph{function}, in the mathematical sense. That function takes inputs,
398 such as build scripts, a compiler, and libraries, and
399 returns an installed package. As a pure function, its result depends
400 solely on its inputs---for instance, it cannot refer to software or
401 scripts that were not explicitly passed as inputs. A build function
402 always produces the same result when passed a given set of inputs. It
403 cannot alter the environment of the running system in
404 any way; for instance, it cannot create, modify, or delete files outside
405 of its build and installation directories. This is achieved by running
406 build processes in isolated environments (or @dfn{containers}), where only their
407 explicit inputs are visible.
410 The result of package build functions is @dfn{cached} in the file
411 system, in a special directory called @dfn{the store} (@pxref{The
412 Store}). Each package is installed in a directory of its own in the
413 store---by default under @file{/gnu/store}. The directory name contains
414 a hash of all the inputs used to build that package; thus, changing an
415 input yields a different directory name.
417 This approach is the foundation for the salient features of Guix: support
418 for transactional package upgrade and rollback, per-user installation, and
419 garbage collection of packages (@pxref{Features}).
422 @node GNU Distribution
423 @section GNU Distribution
426 Guix comes with a distribution of the GNU system consisting entirely of
427 free software@footnote{The term ``free'' here refers to the
428 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
429 users of that software}.}. The
430 distribution can be installed on its own (@pxref{System Installation}),
431 but it is also possible to install Guix as a package manager on top of
432 an installed GNU/Linux system (@pxref{Installation}). When we need to
433 distinguish between the two, we refer to the standalone distribution as
436 The distribution provides core GNU packages such as GNU libc, GCC, and
437 Binutils, as well as many GNU and non-GNU applications. The complete
438 list of available packages can be browsed
439 @url{https://www.gnu.org/software/guix/packages,on-line} or by
440 running @command{guix package} (@pxref{Invoking guix package}):
443 guix package --list-available
446 Our goal is to provide a practical 100% free software distribution of
447 Linux-based and other variants of GNU, with a focus on the promotion and
448 tight integration of GNU components, and an emphasis on programs and
449 tools that help users exert that freedom.
451 Packages are currently available on the following platforms:
456 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
459 Intel 32-bit architecture (IA32), Linux-Libre kernel;
462 ARMv7-A architecture with hard float, Thumb-2 and NEON,
463 using the EABI hard-float application binary interface (ABI),
464 and Linux-Libre kernel.
467 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
469 @item mips64el-linux (deprecated)
470 little-endian 64-bit MIPS processors, specifically the Loongson series,
471 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
472 supported; in particular, there is no ongoing work to ensure that this
473 architecture still works. Should someone decide they wish to revive this
474 architecture then the code is still available.
478 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
479 configuration and Guix takes care of instantiating the configuration in a
480 transactional, reproducible, and stateless fashion (@pxref{System
481 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
482 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
483 Manual}), the well-known GNU utilities and tool chain, as well as the
484 graphical environment or system services of your choice.
486 Guix System is available on all the above platforms except
487 @code{mips64el-linux}.
490 For information on porting to other architectures or kernels,
493 Building this distribution is a cooperative effort, and you are invited
494 to join! @xref{Contributing}, for information about how you can help.
497 @c *********************************************************************
499 @chapter Installation
501 @cindex installing Guix
504 We recommend the use of this
505 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
506 shell installer script} to install Guix on top of a running GNU/Linux system,
507 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
508 with the installation of the package manager, which can be done on top of a
509 running GNU/Linux system. If, instead, you want to install the complete GNU
510 operating system, @pxref{System Installation}.} The script automates the
511 download, installation, and initial configuration of Guix. It should be run
515 @cindex foreign distro
516 @cindex directories related to foreign distro
517 When installed on a foreign distro, GNU@tie{}Guix complements the available
518 tools without interference. Its data lives exclusively in two directories,
519 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
520 such as @file{/etc}, are left untouched.
522 Once installed, Guix can be updated by running @command{guix pull}
523 (@pxref{Invoking guix pull}).
525 If you prefer to perform the installation steps manually or want to tweak
526 them, you may find the following subsections useful. They describe the
527 software requirements of Guix, as well as how to install it manually and get
531 * Binary Installation:: Getting Guix running in no time!
532 * Requirements:: Software needed to build and run Guix.
533 * Running the Test Suite:: Testing Guix.
534 * Setting Up the Daemon:: Preparing the build daemon's environment.
535 * Invoking guix-daemon:: Running the build daemon.
536 * Application Setup:: Application-specific setup.
537 * Upgrading Guix:: Upgrading Guix and its build daemon.
540 @node Binary Installation
541 @section Binary Installation
543 @cindex installing Guix from binaries
544 @cindex installer script
545 This section describes how to install Guix on an arbitrary system from a
546 self-contained tarball providing binaries for Guix and for all its
547 dependencies. This is often quicker than installing from source, which
548 is described in the next sections. The only requirement is to have
551 @c Note duplicated from the ``Installation'' node.
553 We recommend the use of this
554 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
555 shell installer script}. The script automates the download, installation, and
556 initial configuration steps described below. It should be run as the root
557 user. As root, you can thus run this:
561 wget https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh
562 chmod +x guix-install.sh
567 Installing goes along these lines:
571 @cindex downloading Guix binary
572 Download the binary tarball from
573 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz},
574 where @code{x86_64-linux} can be replaced with @code{i686-linux} for an
575 @code{i686} (32-bits) machine already running the kernel Linux, and so on
576 (@pxref{GNU Distribution}).
578 @c The following is somewhat duplicated in ``System Installation''.
579 Make sure to download the associated @file{.sig} file and to verify the
580 authenticity of the tarball against it, along these lines:
583 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
584 $ gpg --verify guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
587 If that command fails because you do not have the required public key,
588 then run this command to import it:
591 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
592 -qO - | gpg --import -
596 and rerun the @code{gpg --verify} command.
598 Take note that a warning like ``This key is not certified with a trusted
599 signature!'' is normal.
601 @c end authentication part
604 Now, you need to become the @code{root} user. Depending on your distribution,
605 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
609 # tar --warning=no-timestamp -xf \
610 /path/to/guix-binary-@value{VERSION}.x86_64-linux.tar.xz
611 # mv var/guix /var/ && mv gnu /
614 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
615 The latter contains a ready-to-use profile for @code{root} (see next
618 Do @emph{not} unpack the tarball on a working Guix system since that
619 would overwrite its own essential files.
621 The @option{--warning=no-timestamp} option makes sure GNU@tie{}tar does
622 not emit warnings about ``implausibly old time stamps'' (such
623 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
625 They stem from the fact that all the
626 files in the archive have their modification time set to zero (which
627 means January 1st, 1970). This is done on purpose to make sure the
628 archive content is independent of its creation time, thus making it
632 Make the profile available under @file{~root/.config/guix/current}, which is
633 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
636 # mkdir -p ~root/.config/guix
637 # ln -sf /var/guix/profiles/per-user/root/current-guix \
638 ~root/.config/guix/current
641 Source @file{etc/profile} to augment @env{PATH} and other relevant
642 environment variables:
645 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
646 source $GUIX_PROFILE/etc/profile
650 Create the group and user accounts for build users as explained below
651 (@pxref{Build Environment Setup}).
654 Run the daemon, and set it to automatically start on boot.
656 If your host distro uses the systemd init system, this can be achieved
659 @c Versions of systemd that supported symlinked service files are not
660 @c yet widely deployed, so we should suggest that users copy the service
663 @c See this thread for more information:
664 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
667 # cp ~root/.config/guix/current/lib/systemd/system/gnu-store.mount \
668 ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
670 # systemctl enable --now gnu-store.mount guix-daemon
673 If your host distro uses the Upstart init system:
676 # initctl reload-configuration
677 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
682 Otherwise, you can still start the daemon manually with:
685 # ~root/.config/guix/current/bin/guix-daemon \
686 --build-users-group=guixbuild
690 Make the @command{guix} command available to other users on the machine,
694 # mkdir -p /usr/local/bin
696 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
699 It is also a good idea to make the Info version of this manual available
703 # mkdir -p /usr/local/share/info
704 # cd /usr/local/share/info
705 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
709 That way, assuming @file{/usr/local/share/info} is in the search path,
710 running @command{info guix} will open this manual (@pxref{Other Info
711 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
715 @cindex substitutes, authorization thereof
716 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
717 (@pxref{Substitutes}), authorize them:
720 # guix archive --authorize < \
721 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
725 Each user may need to perform a few additional steps to make their Guix
726 environment ready for use, @pxref{Application Setup}.
729 Voilà, the installation is complete!
731 You can confirm that Guix is working by installing a sample package into
738 The binary installation tarball can be (re)produced and verified simply
739 by running the following command in the Guix source tree:
742 make guix-binary.@var{system}.tar.xz
746 ...@: which, in turn, runs:
749 guix pack -s @var{system} --localstatedir \
750 --profile-name=current-guix guix
753 @xref{Invoking guix pack}, for more info on this handy tool.
756 @section Requirements
758 This section lists requirements when building Guix from source. The
759 build procedure for Guix is the same as for other GNU software, and is
760 not covered here. Please see the files @file{README} and @file{INSTALL}
761 in the Guix source tree for additional details.
763 @cindex official website
764 GNU Guix is available for download from its website at
765 @url{https://www.gnu.org/software/guix/}.
767 GNU Guix depends on the following packages:
770 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 3.0.x or
772 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
775 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
776 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
777 Guile,, gnutls-guile, GnuTLS-Guile});
779 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
781 @item @uref{https://notabug.org/guile-zlib/guile-zlib, Guile-zlib};
782 @item @uref{https://notabug.org/guile-lzlib/guile-lzlib, Guile-lzlib};
784 @c FIXME: Specify a version number once a release has been made.
785 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
787 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON} 3.x;
788 @item @url{https://www.gnu.org/software/make/, GNU Make}.
791 The following dependencies are optional:
795 @c Note: We need at least 0.13.0 for #:nodelay.
796 Support for build offloading (@pxref{Daemon Offload Setup}) and
797 @command{guix copy} (@pxref{Invoking guix copy}) depends on
798 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
799 version 0.13.0 or later.
802 When @url{https://www.nongnu.org/lzip/lzlib.html, lzlib} is available, lzlib
803 substitutes can be used and @command{guix publish} can compress substitutes
807 When @url{http://www.bzip.org, libbz2} is available,
808 @command{guix-daemon} can use it to compress build logs.
811 Unless @option{--disable-daemon} was passed to @command{configure}, the
812 following packages are also needed:
815 @item @url{https://gnupg.org/, GNU libgcrypt};
816 @item @url{https://sqlite.org, SQLite 3};
817 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
821 @cindex state directory
822 When configuring Guix on a system that already has a Guix installation,
823 be sure to specify the same state directory as the existing installation
824 using the @option{--localstatedir} option of the @command{configure}
825 script (@pxref{Directory Variables, @code{localstatedir},, standards,
826 GNU Coding Standards}). Usually, this @var{localstatedir} option is
827 set to the value @file{/var}. The @command{configure} script protects
828 against unintended misconfiguration of @var{localstatedir} so you do not
829 inadvertently corrupt your store (@pxref{The Store}).
831 @node Running the Test Suite
832 @section Running the Test Suite
835 After a successful @command{configure} and @code{make} run, it is a good
836 idea to run the test suite. It can help catch issues with the setup or
837 environment, or bugs in Guix itself---and really, reporting test
838 failures is a good way to help improve the software. To run the test
845 Test cases can run in parallel: you can use the @code{-j} option of
846 GNU@tie{}make to speed things up. The first run may take a few minutes
847 on a recent machine; subsequent runs will be faster because the store
848 that is created for test purposes will already have various things in
851 It is also possible to run a subset of the tests by defining the
852 @code{TESTS} makefile variable as in this example:
855 make check TESTS="tests/store.scm tests/cpio.scm"
858 By default, tests results are displayed at a file level. In order to
859 see the details of every individual test cases, it is possible to define
860 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
863 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
866 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
867 @file{test-suite.log} file. Please specify the Guix version being used
868 as well as version numbers of the dependencies (@pxref{Requirements}) in
871 Guix also comes with a whole-system test suite that tests complete
872 Guix System instances. It can only run on systems where
873 Guix is already installed, using:
880 or, again, by defining @code{TESTS} to select a subset of tests to run:
883 make check-system TESTS="basic mcron"
886 These system tests are defined in the @code{(gnu tests @dots{})}
887 modules. They work by running the operating systems under test with
888 lightweight instrumentation in a virtual machine (VM). They can be
889 computationally intensive or rather cheap, depending on whether
890 substitutes are available for their dependencies (@pxref{Substitutes}).
891 Some of them require a lot of storage space to hold VM images.
893 Again in case of test failures, please send @email{bug-guix@@gnu.org}
896 @node Setting Up the Daemon
897 @section Setting Up the Daemon
900 Operations such as building a package or running the garbage collector
901 are all performed by a specialized process, the @dfn{build daemon}, on
902 behalf of clients. Only the daemon may access the store and its
903 associated database. Thus, any operation that manipulates the store
904 goes through the daemon. For instance, command-line tools such as
905 @command{guix package} and @command{guix build} communicate with the
906 daemon (@i{via} remote procedure calls) to instruct it what to do.
908 The following sections explain how to prepare the build daemon's
909 environment. See also @ref{Substitutes}, for information on how to allow
910 the daemon to download pre-built binaries.
913 * Build Environment Setup:: Preparing the isolated build environment.
914 * Daemon Offload Setup:: Offloading builds to remote machines.
915 * SELinux Support:: Using an SELinux policy for the daemon.
918 @node Build Environment Setup
919 @subsection Build Environment Setup
921 @cindex build environment
922 In a standard multi-user setup, Guix and its daemon---the
923 @command{guix-daemon} program---are installed by the system
924 administrator; @file{/gnu/store} is owned by @code{root} and
925 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
926 Guix tools to build packages or otherwise access the store, and the
927 daemon will do it on their behalf, ensuring that the store is kept in a
928 consistent state, and allowing built packages to be shared among users.
931 When @command{guix-daemon} runs as @code{root}, you may not want package
932 build processes themselves to run as @code{root} too, for obvious
933 security reasons. To avoid that, a special pool of @dfn{build users}
934 should be created for use by build processes started by the daemon.
935 These build users need not have a shell and a home directory: they will
936 just be used when the daemon drops @code{root} privileges in build
937 processes. Having several such users allows the daemon to launch
938 distinct build processes under separate UIDs, which guarantees that they
939 do not interfere with each other---an essential feature since builds are
940 regarded as pure functions (@pxref{Introduction}).
942 On a GNU/Linux system, a build user pool may be created like this (using
943 Bash syntax and the @code{shadow} commands):
945 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
946 @c for why `-G' is needed.
948 # groupadd --system guixbuild
949 # for i in `seq -w 1 10`;
951 useradd -g guixbuild -G guixbuild \
952 -d /var/empty -s `which nologin` \
953 -c "Guix build user $i" --system \
959 The number of build users determines how many build jobs may run in
960 parallel, as specified by the @option{--max-jobs} option
961 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
962 @command{guix system vm} and related commands, you may need to add the
963 build users to the @code{kvm} group so they can access @file{/dev/kvm},
964 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
965 (@pxref{Invoking guix system}).
967 The @code{guix-daemon} program may then be run as @code{root} with the
968 following command@footnote{If your machine uses the systemd init system,
969 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
970 file in @file{/etc/systemd/system} will ensure that
971 @command{guix-daemon} is automatically started. Similarly, if your
972 machine uses the Upstart init system, drop the
973 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
974 file in @file{/etc/init}.}:
977 # guix-daemon --build-users-group=guixbuild
982 This way, the daemon starts build processes in a chroot, under one of
983 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
984 environment contains nothing but:
986 @c Keep this list in sync with libstore/build.cc! -----------------------
989 a minimal @code{/dev} directory, created mostly independently from the
990 host @code{/dev}@footnote{``Mostly'', because while the set of files
991 that appear in the chroot's @code{/dev} is fixed, most of these files
992 can only be created if the host has them.};
995 the @code{/proc} directory; it only shows the processes of the container
996 since a separate PID name space is used;
999 @file{/etc/passwd} with an entry for the current user and an entry for
1003 @file{/etc/group} with an entry for the user's group;
1006 @file{/etc/hosts} with an entry that maps @code{localhost} to
1010 a writable @file{/tmp} directory.
1013 You can influence the directory where the daemon stores build trees
1014 @i{via} the @env{TMPDIR} environment variable. However, the build tree
1015 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
1016 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
1017 This way, the value of @env{TMPDIR} does not leak inside build
1018 environments, which avoids discrepancies in cases where build processes
1019 capture the name of their build tree.
1023 The daemon also honors the @env{http_proxy} and @env{https_proxy}
1024 environment variables for HTTP and HTTPS downloads it performs, be it
1025 for fixed-output derivations (@pxref{Derivations}) or for substitutes
1026 (@pxref{Substitutes}).
1028 If you are installing Guix as an unprivileged user, it is still possible
1029 to run @command{guix-daemon} provided you pass @option{--disable-chroot}.
1030 However, build processes will not be isolated from one another, and not
1031 from the rest of the system. Thus, build processes may interfere with
1032 each other, and may access programs, libraries, and other files
1033 available on the system---making it much harder to view them as
1034 @emph{pure} functions.
1037 @node Daemon Offload Setup
1038 @subsection Using the Offload Facility
1042 When desired, the build daemon can @dfn{offload} derivation builds to
1043 other machines running Guix, using the @code{offload} @dfn{build
1044 hook}@footnote{This feature is available only when
1045 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1046 present.}. When that feature is enabled, a list of user-specified build
1047 machines is read from @file{/etc/guix/machines.scm}; every time a build
1048 is requested, for instance via @code{guix build}, the daemon attempts to
1049 offload it to one of the machines that satisfy the constraints of the
1050 derivation, in particular its system types---e.g., @code{x86_64-linux}.
1051 A single machine can have multiple system types, either because its
1052 architecture natively supports it, via emulation (@pxref{Transparent
1053 Emulation with QEMU}), or both. Missing prerequisites for the build are
1054 copied over SSH to the target machine, which then proceeds with the
1055 build; upon success the output(s) of the build are copied back to the
1058 The @file{/etc/guix/machines.scm} file typically looks like this:
1061 (list (build-machine
1062 (name "eightysix.example.org")
1063 (systems (list "x86_64-linux" "i686-linux"))
1064 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1066 (speed 2.)) ;incredibly fast!
1069 (name "armeight.example.org")
1070 (systems (list "aarch64-linux"))
1071 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1074 (string-append (getenv "HOME")
1075 "/.ssh/identity-for-guix"))))
1079 In the example above we specify a list of two build machines, one for
1080 the @code{x86_64} and @code{i686} architectures and one for the
1081 @code{aarch64} architecture.
1083 In fact, this file is---not surprisingly!---a Scheme file that is
1084 evaluated when the @code{offload} hook is started. Its return value
1085 must be a list of @code{build-machine} objects. While this example
1086 shows a fixed list of build machines, one could imagine, say, using
1087 DNS-SD to return a list of potential build machines discovered in the
1088 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1089 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1092 @deftp {Data Type} build-machine
1093 This data type represents build machines to which the daemon may offload
1094 builds. The important fields are:
1099 The host name of the remote machine.
1102 The system types the remote machine supports---e.g., @code{(list
1103 "x86_64-linux" "i686-linux")}.
1106 The user account to use when connecting to the remote machine over SSH.
1107 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1108 allow non-interactive logins.
1111 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1112 This is used to authenticate the machine when we connect to it. It is a
1113 long string that looks like this:
1116 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1119 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1120 key can be found in a file such as
1121 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1123 If the machine is running the SSH daemon of GNU@tie{}lsh,
1124 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1125 similar file. It can be converted to the OpenSSH format using
1126 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1129 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1130 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1135 A number of optional fields may be specified:
1139 @item @code{port} (default: @code{22})
1140 Port number of SSH server on the machine.
1142 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1143 The SSH private key file to use when connecting to the machine, in
1144 OpenSSH format. This key must not be protected with a passphrase.
1146 Note that the default value is the private key @emph{of the root
1147 account}. Make sure it exists if you use the default.
1149 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1150 @itemx @code{compression-level} (default: @code{3})
1151 The SSH-level compression methods and compression level requested.
1153 Note that offloading relies on SSH compression to reduce bandwidth usage
1154 when transferring files to and from build machines.
1156 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1157 File name of the Unix-domain socket @command{guix-daemon} is listening
1160 @item @code{parallel-builds} (default: @code{1})
1161 The number of builds that may run in parallel on the machine.
1163 @item @code{speed} (default: @code{1.0})
1164 A ``relative speed factor''. The offload scheduler will tend to prefer
1165 machines with a higher speed factor.
1167 @item @code{features} (default: @code{'()})
1168 A list of strings denoting specific features supported by the machine.
1169 An example is @code{"kvm"} for machines that have the KVM Linux modules
1170 and corresponding hardware support. Derivations can request features by
1171 name, and they will be scheduled on matching build machines.
1176 The @command{guix} command must be in the search path on the build
1177 machines. You can check whether this is the case by running:
1180 ssh build-machine guix repl --version
1183 There is one last thing to do once @file{machines.scm} is in place. As
1184 explained above, when offloading, files are transferred back and forth
1185 between the machine stores. For this to work, you first need to
1186 generate a key pair on each machine to allow the daemon to export signed
1187 archives of files from the store (@pxref{Invoking guix archive}):
1190 # guix archive --generate-key
1194 Each build machine must authorize the key of the master machine so that
1195 it accepts store items it receives from the master:
1198 # guix archive --authorize < master-public-key.txt
1202 Likewise, the master machine must authorize the key of each build machine.
1204 All the fuss with keys is here to express pairwise mutual trust
1205 relations between the master and the build machines. Concretely, when
1206 the master receives files from a build machine (and @i{vice versa}), its
1207 build daemon can make sure they are genuine, have not been tampered
1208 with, and that they are signed by an authorized key.
1210 @cindex offload test
1211 To test whether your setup is operational, run this command on the
1218 This will attempt to connect to each of the build machines specified in
1219 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1220 available on each machine, attempt to export to the machine and import
1221 from it, and report any error in the process.
1223 If you want to test a different machine file, just specify it on the
1227 # guix offload test machines-qualif.scm
1230 Last, you can test the subset of the machines whose name matches a
1231 regular expression like this:
1234 # guix offload test machines.scm '\.gnu\.org$'
1237 @cindex offload status
1238 To display the current load of all build hosts, run this command on the
1242 # guix offload status
1246 @node SELinux Support
1247 @subsection SELinux Support
1249 @cindex SELinux, daemon policy
1250 @cindex mandatory access control, SELinux
1251 @cindex security, guix-daemon
1252 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1253 can be installed on a system where SELinux is enabled, in order to label
1254 Guix files and to specify the expected behavior of the daemon. Since
1255 Guix System does not provide an SELinux base policy, the daemon policy cannot
1256 be used on Guix System.
1258 @subsubsection Installing the SELinux policy
1259 @cindex SELinux, policy installation
1260 To install the policy run this command as root:
1263 semodule -i etc/guix-daemon.cil
1266 Then relabel the file system with @code{restorecon} or by a different
1267 mechanism provided by your system.
1269 Once the policy is installed, the file system has been relabeled, and
1270 the daemon has been restarted, it should be running in the
1271 @code{guix_daemon_t} context. You can confirm this with the following
1275 ps -Zax | grep guix-daemon
1278 Monitor the SELinux log files as you run a command like @code{guix build
1279 hello} to convince yourself that SELinux permits all necessary
1282 @subsubsection Limitations
1283 @cindex SELinux, limitations
1285 This policy is not perfect. Here is a list of limitations or quirks
1286 that should be considered when deploying the provided SELinux policy for
1291 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1292 operations involve contexts that have anything to do with
1293 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1294 but it would be preferrable to define socket rules for only this label.
1297 @code{guix gc} cannot access arbitrary links to profiles. By design,
1298 the file label of the destination of a symlink is independent of the
1299 file label of the link itself. Although all profiles under
1300 $localstatedir are labelled, the links to these profiles inherit the
1301 label of the directory they are in. For links in the user’s home
1302 directory this will be @code{user_home_t}. But for links from the root
1303 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1304 directory, etc, this won’t work. @code{guix gc} would be prevented from
1305 reading and following these links.
1308 The daemon’s feature to listen for TCP connections might no longer work.
1309 This might require extra rules, because SELinux treats network sockets
1310 differently from files.
1313 Currently all files with a name matching the regular expression
1314 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1315 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1316 that name in any profile would be permitted to run in the
1317 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1318 build a package that provides this executable and convince a user to
1319 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1320 At that point SELinux could not prevent it from accessing files that are
1321 allowed for processes in that domain.
1323 We could generate a much more restrictive policy at installation time,
1324 so that only the @emph{exact} file name of the currently installed
1325 @code{guix-daemon} executable would be labelled with
1326 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1327 The downside is that root would have to install or upgrade the policy at
1328 installation time whenever the Guix package that provides the
1329 effectively running @code{guix-daemon} executable is upgraded.
1332 @node Invoking guix-daemon
1333 @section Invoking @command{guix-daemon}
1335 The @command{guix-daemon} program implements all the functionality to
1336 access the store. This includes launching build processes, running the
1337 garbage collector, querying the availability of a build result, etc. It
1338 is normally run as @code{root} like this:
1341 # guix-daemon --build-users-group=guixbuild
1345 For details on how to set it up, @pxref{Setting Up the Daemon}.
1348 @cindex container, build environment
1349 @cindex build environment
1350 @cindex reproducible builds
1351 By default, @command{guix-daemon} launches build processes under
1352 different UIDs, taken from the build group specified with
1353 @option{--build-users-group}. In addition, each build process is run in a
1354 chroot environment that only contains the subset of the store that the
1355 build process depends on, as specified by its derivation
1356 (@pxref{Programming Interface, derivation}), plus a set of specific
1357 system directories. By default, the latter contains @file{/dev} and
1358 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1359 @dfn{container}: in addition to having its own file system tree, it has
1360 a separate mount name space, its own PID name space, network name space,
1361 etc. This helps achieve reproducible builds (@pxref{Features}).
1363 When the daemon performs a build on behalf of the user, it creates a
1364 build directory under @file{/tmp} or under the directory specified by
1365 its @env{TMPDIR} environment variable. This directory is shared with
1366 the container for the duration of the build, though within the container,
1367 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1369 The build directory is automatically deleted upon completion, unless the
1370 build failed and the client specified @option{--keep-failed}
1371 (@pxref{Invoking guix build, @option{--keep-failed}}).
1373 The daemon listens for connections and spawns one sub-process for each session
1374 started by a client (one of the @command{guix} sub-commands). The
1375 @command{guix processes} command allows you to get an overview of the activity
1376 on your system by viewing each of the active sessions and clients.
1377 @xref{Invoking guix processes}, for more information.
1379 The following command-line options are supported:
1382 @item --build-users-group=@var{group}
1383 Take users from @var{group} to run build processes (@pxref{Setting Up
1384 the Daemon, build users}).
1386 @item --no-substitutes
1388 Do not use substitutes for build products. That is, always build things
1389 locally instead of allowing downloads of pre-built binaries
1390 (@pxref{Substitutes}).
1392 When the daemon runs with @option{--no-substitutes}, clients can still
1393 explicitly enable substitution @i{via} the @code{set-build-options}
1394 remote procedure call (@pxref{The Store}).
1396 @item --substitute-urls=@var{urls}
1397 @anchor{daemon-substitute-urls}
1398 Consider @var{urls} the default whitespace-separated list of substitute
1399 source URLs. When this option is omitted,
1400 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1402 This means that substitutes may be downloaded from @var{urls}, as long
1403 as they are signed by a trusted signature (@pxref{Substitutes}).
1407 Do not use offload builds to other machines (@pxref{Daemon Offload
1408 Setup}). That is, always build things locally instead of offloading
1409 builds to remote machines.
1411 @item --cache-failures
1412 Cache build failures. By default, only successful builds are cached.
1414 When this option is used, @command{guix gc --list-failures} can be used
1415 to query the set of store items marked as failed; @command{guix gc
1416 --clear-failures} removes store items from the set of cached failures.
1417 @xref{Invoking guix gc}.
1419 @item --cores=@var{n}
1421 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1424 The default value is @code{0}, but it may be overridden by clients, such
1425 as the @option{--cores} option of @command{guix build} (@pxref{Invoking
1428 The effect is to define the @env{NIX_BUILD_CORES} environment variable
1429 in the build process, which can then use it to exploit internal
1430 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1432 @item --max-jobs=@var{n}
1434 Allow at most @var{n} build jobs in parallel. The default value is
1435 @code{1}. Setting it to @code{0} means that no builds will be performed
1436 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1437 Setup}), or simply fail.
1439 @item --max-silent-time=@var{seconds}
1440 When the build or substitution process remains silent for more than
1441 @var{seconds}, terminate it and report a build failure.
1443 The default value is @code{0}, which disables the timeout.
1445 The value specified here can be overridden by clients (@pxref{Common
1446 Build Options, @option{--max-silent-time}}).
1448 @item --timeout=@var{seconds}
1449 Likewise, when the build or substitution process lasts for more than
1450 @var{seconds}, terminate it and report a build failure.
1452 The default value is @code{0}, which disables the timeout.
1454 The value specified here can be overridden by clients (@pxref{Common
1455 Build Options, @option{--timeout}}).
1457 @item --rounds=@var{N}
1458 Build each derivation @var{n} times in a row, and raise an error if
1459 consecutive build results are not bit-for-bit identical. Note that this
1460 setting can be overridden by clients such as @command{guix build}
1461 (@pxref{Invoking guix build}).
1463 When used in conjunction with @option{--keep-failed}, the differing
1464 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1465 This makes it easy to look for differences between the two results.
1468 Produce debugging output.
1470 This is useful to debug daemon start-up issues, but then it may be
1471 overridden by clients, for example the @option{--verbosity} option of
1472 @command{guix build} (@pxref{Invoking guix build}).
1474 @item --chroot-directory=@var{dir}
1475 Add @var{dir} to the build chroot.
1477 Doing this may change the result of build processes---for instance if
1478 they use optional dependencies found in @var{dir} when it is available,
1479 and not otherwise. For that reason, it is not recommended to do so.
1480 Instead, make sure that each derivation declares all the inputs that it
1483 @item --disable-chroot
1484 Disable chroot builds.
1486 Using this option is not recommended since, again, it would allow build
1487 processes to gain access to undeclared dependencies. It is necessary,
1488 though, when @command{guix-daemon} is running under an unprivileged user
1491 @item --log-compression=@var{type}
1492 Compress build logs according to @var{type}, one of @code{gzip},
1493 @code{bzip2}, or @code{none}.
1495 Unless @option{--lose-logs} is used, all the build logs are kept in the
1496 @var{localstatedir}. To save space, the daemon automatically compresses
1497 them with Bzip2 by default.
1499 @item --disable-deduplication
1500 @cindex deduplication
1501 Disable automatic file ``deduplication'' in the store.
1503 By default, files added to the store are automatically ``deduplicated'':
1504 if a newly added file is identical to another one found in the store,
1505 the daemon makes the new file a hard link to the other file. This can
1506 noticeably reduce disk usage, at the expense of slightly increased
1507 input/output load at the end of a build process. This option disables
1510 @item --gc-keep-outputs[=yes|no]
1511 Tell whether the garbage collector (GC) must keep outputs of live
1515 @cindex garbage collector roots
1516 When set to @code{yes}, the GC will keep the outputs of any live
1517 derivation available in the store---the @file{.drv} files. The default
1518 is @code{no}, meaning that derivation outputs are kept only if they are
1519 reachable from a GC root. @xref{Invoking guix gc}, for more on GC
1522 @item --gc-keep-derivations[=yes|no]
1523 Tell whether the garbage collector (GC) must keep derivations
1524 corresponding to live outputs.
1526 When set to @code{yes}, as is the case by default, the GC keeps
1527 derivations---i.e., @file{.drv} files---as long as at least one of their
1528 outputs is live. This allows users to keep track of the origins of
1529 items in their store. Setting it to @code{no} saves a bit of disk
1532 In this way, setting @option{--gc-keep-derivations} to @code{yes} causes
1533 liveness to flow from outputs to derivations, and setting
1534 @option{--gc-keep-outputs} to @code{yes} causes liveness to flow from
1535 derivations to outputs. When both are set to @code{yes}, the effect is
1536 to keep all the build prerequisites (the sources, compiler, libraries,
1537 and other build-time tools) of live objects in the store, regardless of
1538 whether these prerequisites are reachable from a GC root. This is
1539 convenient for developers since it saves rebuilds or downloads.
1541 @item --impersonate-linux-2.6
1542 On Linux-based systems, impersonate Linux 2.6. This means that the
1543 kernel's @command{uname} system call will report 2.6 as the release number.
1545 This might be helpful to build programs that (usually wrongfully) depend
1546 on the kernel version number.
1549 Do not keep build logs. By default they are kept under
1550 @file{@var{localstatedir}/guix/log}.
1552 @item --system=@var{system}
1553 Assume @var{system} as the current system type. By default it is the
1554 architecture/kernel pair found at configure time, such as
1555 @code{x86_64-linux}.
1557 @item --listen=@var{endpoint}
1558 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1559 as the file name of a Unix-domain socket if it starts with
1560 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1561 host name or host name and port to listen to. Here are a few examples:
1564 @item --listen=/gnu/var/daemon
1565 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1566 creating it if needed.
1568 @item --listen=localhost
1569 @cindex daemon, remote access
1570 @cindex remote access to the daemon
1571 @cindex daemon, cluster setup
1572 @cindex clusters, daemon setup
1573 Listen for TCP connections on the network interface corresponding to
1574 @code{localhost}, on port 44146.
1576 @item --listen=128.0.0.42:1234
1577 Listen for TCP connections on the network interface corresponding to
1578 @code{128.0.0.42}, on port 1234.
1581 This option can be repeated multiple times, in which case
1582 @command{guix-daemon} accepts connections on all the specified
1583 endpoints. Users can tell client commands what endpoint to connect to
1584 by setting the @env{GUIX_DAEMON_SOCKET} environment variable
1585 (@pxref{The Store, @env{GUIX_DAEMON_SOCKET}}).
1588 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1589 @option{--listen=@var{host}} is suitable on local networks, such as
1590 clusters, where only trusted nodes may connect to the build daemon. In
1591 other cases where remote access to the daemon is needed, we recommend
1592 using Unix-domain sockets along with SSH.
1595 When @option{--listen} is omitted, @command{guix-daemon} listens for
1596 connections on the Unix-domain socket located at
1597 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1601 @node Application Setup
1602 @section Application Setup
1604 @cindex foreign distro
1605 When using Guix on top of GNU/Linux distribution other than Guix System---a
1606 so-called @dfn{foreign distro}---a few additional steps are needed to
1607 get everything in place. Here are some of them.
1611 @anchor{locales-and-locpath}
1612 @cindex locales, when not on Guix System
1614 @vindex GUIX_LOCPATH
1615 Packages installed @i{via} Guix will not use the locale data of the
1616 host system. Instead, you must first install one of the locale packages
1617 available with Guix and then define the @env{GUIX_LOCPATH} environment
1621 $ guix install glibc-locales
1622 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1625 Note that the @code{glibc-locales} package contains data for all the
1626 locales supported by the GNU@tie{}libc and weighs in at around
1627 917@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1628 limited to a few UTF-8 locales.
1630 The @env{GUIX_LOCPATH} variable plays a role similar to @env{LOCPATH}
1631 (@pxref{Locale Names, @env{LOCPATH},, libc, The GNU C Library Reference
1632 Manual}). There are two important differences though:
1636 @env{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1637 provided by foreign distros. Thus, using @env{GUIX_LOCPATH} allows you
1638 to make sure the programs of the foreign distro will not end up loading
1639 incompatible locale data.
1642 libc suffixes each entry of @env{GUIX_LOCPATH} with @code{/X.Y}, where
1643 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1644 should your Guix profile contain a mixture of programs linked against
1645 different libc version, each libc version will only try to load locale
1646 data in the right format.
1649 This is important because the locale data format used by different libc
1650 versions may be incompatible.
1652 @subsection Name Service Switch
1654 @cindex name service switch, glibc
1655 @cindex NSS (name service switch), glibc
1656 @cindex nscd (name service caching daemon)
1657 @cindex name service caching daemon (nscd)
1658 When using Guix on a foreign distro, we @emph{strongly recommend} that
1659 the system run the GNU C library's @dfn{name service cache daemon},
1660 @command{nscd}, which should be listening on the
1661 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1662 installed with Guix may fail to look up host names or user accounts, or
1663 may even crash. The next paragraphs explain why.
1665 @cindex @file{nsswitch.conf}
1666 The GNU C library implements a @dfn{name service switch} (NSS), which is
1667 an extensible mechanism for ``name lookups'' in general: host name
1668 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1669 The GNU C Library Reference Manual}).
1671 @cindex Network information service (NIS)
1672 @cindex NIS (Network information service)
1673 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1674 lookup implementations: for example, the @code{nss-mdns} plugin allow
1675 resolution of @code{.local} host names, the @code{nis} plugin allows
1676 user account lookup using the Network information service (NIS), and so
1677 on. These extra ``lookup services'' are configured system-wide in
1678 @file{/etc/nsswitch.conf}, and all the programs running on the system
1679 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1682 When they perform a name lookup---for instance by calling the
1683 @code{getaddrinfo} function in C---applications first try to connect to
1684 the nscd; on success, nscd performs name lookups on their behalf. If
1685 the nscd is not running, then they perform the name lookup by
1686 themselves, by loading the name lookup services into their own address
1687 space and running it. These name lookup services---the
1688 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1689 the host system's C library, rather than from the C library the
1690 application is linked against (the C library coming from Guix).
1692 And this is where the problem is: if your application is linked against
1693 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1694 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1695 likely crash or have its name lookups fail unexpectedly.
1697 Running @command{nscd} on the system, among other advantages, eliminates
1698 this binary incompatibility problem because those @code{libnss_*.so}
1699 files are loaded in the @command{nscd} process, not in applications
1702 @subsection X11 Fonts
1705 The majority of graphical applications use Fontconfig to locate and
1706 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1707 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1708 by default. Thus, to allow graphical applications installed with Guix
1709 to display fonts, you have to install fonts with Guix as well.
1710 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1711 @code{font-gnu-freefont}.
1713 @cindex @code{fc-cache}
1715 Once you have installed or removed fonts, or when you notice an
1716 application that does not find fonts, you may need to install Fontconfig
1717 and to force an update of its font cache by running:
1720 guix install fontconfig
1724 To display text written in Chinese languages, Japanese, or Korean in
1725 graphical applications, consider installing
1726 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1727 has multiple outputs, one per language family (@pxref{Packages with
1728 Multiple Outputs}). For instance, the following command installs fonts
1729 for Chinese languages:
1732 guix install font-adobe-source-han-sans:cn
1735 @cindex @code{xterm}
1736 Older programs such as @command{xterm} do not use Fontconfig and instead
1737 rely on server-side font rendering. Such programs require to specify a
1738 full name of a font using XLFD (X Logical Font Description), like this:
1741 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1744 To be able to use such full names for the TrueType fonts installed in
1745 your Guix profile, you need to extend the font path of the X server:
1747 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1748 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1750 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1753 @cindex @code{xlsfonts}
1754 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1755 to make sure your TrueType fonts are listed there.
1758 @subsection X.509 Certificates
1760 @cindex @code{nss-certs}
1761 The @code{nss-certs} package provides X.509 certificates, which allow
1762 programs to authenticate Web servers accessed over HTTPS.
1764 When using Guix on a foreign distro, you can install this package and
1765 define the relevant environment variables so that packages know where to
1766 look for certificates. @xref{X.509 Certificates}, for detailed
1769 @subsection Emacs Packages
1771 @cindex @code{emacs}
1772 When you install Emacs packages with Guix, the Elisp files are placed
1773 under the @file{share/emacs/site-lisp/} directory of the profile in
1774 which they are installed. The Elisp libraries are made available to
1775 Emacs through the @env{EMACSLOADPATH} environment variable, which is
1776 set when installing Emacs itself.
1778 Additionally, autoload definitions are automatically evaluated at the
1779 initialization of Emacs, by the Guix-specific
1780 @code{guix-emacs-autoload-packages} procedure. If, for some reason, you
1781 want to avoid auto-loading the Emacs packages installed with Guix, you
1782 can do so by running Emacs with the @option{--no-site-file} option
1783 (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1786 @node Upgrading Guix
1787 @section Upgrading Guix
1789 @cindex Upgrading Guix, on a foreign distro
1791 To upgrade Guix, run:
1797 @xref{Invoking guix pull}, for more information.
1799 @cindex upgrading Guix for the root user, on a foreign distro
1800 @cindex upgrading the Guix daemon, on a foreign distro
1801 @cindex @command{guix pull} for the root user, on a foreign distro
1803 On a foreign distro, you can upgrade the build daemon by running:
1810 followed by (assuming your distro uses the systemd service management
1814 systemctl restart guix-daemon.service
1817 On Guix System, upgrading the daemon is achieved by reconfiguring the
1818 system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
1822 @c *********************************************************************
1823 @node System Installation
1824 @chapter System Installation
1826 @cindex installing Guix System
1827 @cindex Guix System, installation
1828 This section explains how to install Guix System
1829 on a machine. Guix, as a package manager, can
1830 also be installed on top of a running GNU/Linux system,
1831 @pxref{Installation}.
1835 @c This paragraph is for people reading this from tty2 of the
1836 @c installation image.
1837 You are reading this documentation with an Info reader. For details on
1838 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1839 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1840 Info}. Hit @kbd{l} afterwards to come back here.
1842 Alternatively, run @command{info info} in another tty to keep the manual
1848 * Limitations:: What you can expect.
1849 * Hardware Considerations:: Supported hardware.
1850 * USB Stick and DVD Installation:: Preparing the installation medium.
1851 * Preparing for Installation:: Networking, partitioning, etc.
1852 * Guided Graphical Installation:: Easy graphical installation.
1853 * Manual Installation:: Manual installation for wizards.
1854 * After System Installation:: When installation succeeded.
1855 * Installing Guix in a VM:: Guix System playground.
1856 * Building the Installation Image:: How this comes to be.
1860 @section Limitations
1862 We consider Guix System to be ready for a wide range of ``desktop'' and server
1863 use cases. The reliability guarantees it provides---transactional upgrades
1864 and rollbacks, reproducibility---make it a solid foundation.
1866 Nevertheless, before you proceed with the installation, be aware of the
1867 following noteworthy limitations applicable to version @value{VERSION}:
1871 Support for the Logical Volume Manager (LVM) is missing.
1874 More and more system services are provided (@pxref{Services}), but some
1878 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1879 as well as a number of X11 window managers. However, KDE is currently
1883 More than a disclaimer, this is an invitation to report issues (and success
1884 stories!), and to join us in improving it. @xref{Contributing}, for more
1888 @node Hardware Considerations
1889 @section Hardware Considerations
1891 @cindex hardware support on Guix System
1892 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1893 builds around the kernel Linux-libre, which means that only hardware for
1894 which free software drivers and firmware exist is supported. Nowadays,
1895 a wide range of off-the-shelf hardware is supported on
1896 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1897 Ethernet controllers. Unfortunately, there are still areas where
1898 hardware vendors deny users control over their own computing, and such
1899 hardware is not supported on Guix System.
1901 @cindex WiFi, hardware support
1902 One of the main areas where free drivers or firmware are lacking is WiFi
1903 devices. WiFi devices known to work include those using Atheros chips
1904 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1905 driver, and those using Broadcom/AirForce chips (BCM43xx with
1906 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1907 Linux-libre driver. Free firmware exists for both and is available
1908 out-of-the-box on Guix System, as part of @code{%base-firmware}
1909 (@pxref{operating-system Reference, @code{firmware}}).
1911 @cindex RYF, Respects Your Freedom
1912 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1913 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1914 certification program for hardware products that respect your freedom
1915 and your privacy and ensure that you have control over your device. We
1916 encourage you to check the list of RYF-certified devices.
1918 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1919 web site. It contains a catalog of hardware devices with information
1920 about their support in GNU/Linux.
1923 @node USB Stick and DVD Installation
1924 @section USB Stick and DVD Installation
1926 An ISO-9660 installation image that can be written to a USB stick or
1927 burnt to a DVD can be downloaded from
1928 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz},
1929 where you can replace @code{x86_64-linux} with one of:
1933 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1936 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1939 @c start duplication of authentication part from ``Binary Installation''
1940 Make sure to download the associated @file{.sig} file and to verify the
1941 authenticity of the image against it, along these lines:
1944 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
1945 $ gpg --verify guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
1948 If that command fails because you do not have the required public key,
1949 then run this command to import it:
1952 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
1953 -qO - | gpg --import -
1957 and rerun the @code{gpg --verify} command.
1959 Take note that a warning like ``This key is not certified with a trusted
1960 signature!'' is normal.
1964 This image contains the tools necessary for an installation.
1965 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1967 @unnumberedsubsec Copying to a USB Stick
1969 To copy the image to a USB stick, follow these steps:
1973 Decompress the image using the @command{xz} command:
1976 xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
1980 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1981 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1982 copy the image with:
1985 dd if=guix-system-install-@value{VERSION}.x86_64-linux.iso of=/dev/sdX status=progress
1989 Access to @file{/dev/sdX} usually requires root privileges.
1992 @unnumberedsubsec Burning on a DVD
1994 To copy the image to a DVD, follow these steps:
1998 Decompress the image using the @command{xz} command:
2001 xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
2005 Insert a blank DVD into your machine, and determine
2006 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
2007 copy the image with:
2010 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.x86_64-linux.iso
2013 Access to @file{/dev/srX} usually requires root privileges.
2016 @unnumberedsubsec Booting
2018 Once this is done, you should be able to reboot the system and boot from
2019 the USB stick or DVD. The latter usually requires you to get in the
2020 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
2021 In order to boot from Libreboot, switch to the command mode by pressing
2022 the @kbd{c} key and type @command{search_grub usb}.
2024 @xref{Installing Guix in a VM}, if, instead, you would like to install
2025 Guix System in a virtual machine (VM).
2028 @node Preparing for Installation
2029 @section Preparing for Installation
2031 Once you have booted, you can use the guided graphical installer, which makes
2032 it easy to get started (@pxref{Guided Graphical Installation}). Alternatively,
2033 if you are already familiar with GNU/Linux and if you want more control than
2034 what the graphical installer provides, you can choose the ``manual''
2035 installation process (@pxref{Manual Installation}).
2037 The graphical installer is available on TTY1. You can obtain root shells on
2038 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
2039 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
2040 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
2041 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2042 which allows you to select text with the left mouse button and to paste it
2043 with the middle button.
2046 Installation requires access to the Internet so that any missing
2047 dependencies of your system configuration can be downloaded. See the
2048 ``Networking'' section below.
2051 @node Guided Graphical Installation
2052 @section Guided Graphical Installation
2054 The graphical installer is a text-based user interface. It will guide you,
2055 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2057 The first dialog boxes allow you to set up the system as you use it during the
2058 installation: you can choose the language, keyboard layout, and set up
2059 networking, which will be used during the installation. The image below shows
2060 the networking dialog.
2062 @image{images/installer-network,5in,, networking setup with the graphical installer}
2064 Later steps allow you to partition your hard disk, as shown in the image
2065 below, to choose whether or not to use encrypted file systems, to enter the
2066 host name and root password, and to create an additional account, among other
2069 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2071 Note that, at any time, the installer allows you to exit the current
2072 installation step and resume at a previous step, as show in the image below.
2074 @image{images/installer-resume,5in,, resuming the installation process}
2076 Once you're done, the installer produces an operating system configuration and
2077 displays it (@pxref{Using the Configuration System}). At that point you can
2078 hit ``OK'' and installation will proceed. On success, you can reboot into the
2079 new system and enjoy. @xref{After System Installation}, for what's next!
2082 @node Manual Installation
2083 @section Manual Installation
2085 This section describes how you would ``manually'' install GNU@tie{}Guix System
2086 on your machine. This option requires familiarity with GNU/Linux, with the
2087 shell, and with common administration tools. If you think this is not for
2088 you, consider using the guided graphical installer (@pxref{Guided Graphical
2091 The installation system provides root shells on TTYs 3 to 6; press
2092 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2093 many common tools needed to install the system. But it is also a full-blown
2094 Guix System, which means that you can install additional packages, should you
2095 need it, using @command{guix package} (@pxref{Invoking guix package}).
2098 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2099 * Proceeding with the Installation:: Installing.
2102 @node Keyboard Layout and Networking and Partitioning
2103 @subsection Keyboard Layout, Networking, and Partitioning
2105 Before you can install the system, you may want to adjust the keyboard layout,
2106 set up networking, and partition your target hard disk. This section will
2107 guide you through this.
2109 @subsubsection Keyboard Layout
2111 @cindex keyboard layout
2112 The installation image uses the US qwerty keyboard layout. If you want
2113 to change it, you can use the @command{loadkeys} command. For example,
2114 the following command selects the Dvorak keyboard layout:
2120 See the files under @file{/run/current-system/profile/share/keymaps} for
2121 a list of available keyboard layouts. Run @command{man loadkeys} for
2124 @subsubsection Networking
2126 Run the following command to see what your network interfaces are called:
2133 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2139 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2140 Wired interfaces have a name starting with @samp{e}; for example, the
2141 interface corresponding to the first on-board Ethernet controller is
2142 called @samp{eno1}. Wireless interfaces have a name starting with
2143 @samp{w}, like @samp{w1p2s0}.
2146 @item Wired connection
2147 To configure a wired network run the following command, substituting
2148 @var{interface} with the name of the wired interface you want to use.
2151 ifconfig @var{interface} up
2155 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2158 ip link set @var{interface} up
2161 @item Wireless connection
2164 To configure wireless networking, you can create a configuration file
2165 for the @command{wpa_supplicant} configuration tool (its location is not
2166 important) using one of the available text editors such as
2170 nano wpa_supplicant.conf
2173 As an example, the following stanza can go to this file and will work
2174 for many wireless networks, provided you give the actual SSID and
2175 passphrase for the network you are connecting to:
2179 ssid="@var{my-ssid}"
2181 psk="the network's secret passphrase"
2185 Start the wireless service and run it in the background with the
2186 following command (substitute @var{interface} with the name of the
2187 network interface you want to use):
2190 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2193 Run @command{man wpa_supplicant} for more information.
2197 At this point, you need to acquire an IP address. On a network where IP
2198 addresses are automatically assigned @i{via} DHCP, you can run:
2201 dhclient -v @var{interface}
2204 Try to ping a server to see if networking is up and running:
2210 Setting up network access is almost always a requirement because the
2211 image does not contain all the software and tools that may be needed.
2213 @cindex proxy, during system installation
2214 If you need HTTP and HTTPS access to go through a proxy, run the
2218 herd set-http-proxy guix-daemon @var{URL}
2222 where @var{URL} is the proxy URL, for example
2223 @code{http://example.org:8118}.
2225 @cindex installing over SSH
2226 If you want to, you can continue the installation remotely by starting
2230 herd start ssh-daemon
2233 Make sure to either set a password with @command{passwd}, or configure
2234 OpenSSH public key authentication before logging in.
2236 @subsubsection Disk Partitioning
2238 Unless this has already been done, the next step is to partition, and
2239 then format the target partition(s).
2241 The installation image includes several partitioning tools, including
2242 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2243 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2244 the partition layout you want:
2250 If your disk uses the GUID Partition Table (GPT) format and you plan to
2251 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2252 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2255 @cindex EFI, installation
2256 @cindex UEFI, installation
2257 @cindex ESP, EFI system partition
2258 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2259 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2260 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2263 parted /dev/sda set 1 esp on
2267 @vindex grub-bootloader
2268 @vindex grub-efi-bootloader
2269 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2270 @file{/sys/firmware/efi} exists in the installation image, then you should
2271 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2272 Otherwise you should use the BIOS-based GRUB, known as
2273 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2277 Once you are done partitioning the target hard disk drive, you have to
2278 create a file system on the relevant partition(s)@footnote{Currently
2279 Guix System only supports ext4, btrfs, and JFS file systems. In particular,
2280 code that reads file system UUIDs and labels only works for these file system
2281 types.}. For the ESP, if you have one and assuming it is
2282 @file{/dev/sda1}, run:
2285 mkfs.fat -F32 /dev/sda1
2288 For the root file system, ext4 is the most widely used format. Other
2289 file systems, such as Btrfs, support compression, which is reported to
2290 nicely complement file deduplication that the daemon performs
2291 independently of the file system (@pxref{Invoking guix-daemon,
2294 Preferably, assign file systems a label so that you can easily and
2295 reliably refer to them in @code{file-system} declarations (@pxref{File
2296 Systems}). This is typically done using the @code{-L} option of
2297 @command{mkfs.ext4} and related commands. So, assuming the target root
2298 partition lives at @file{/dev/sda2}, a file system with the label
2299 @code{my-root} can be created with:
2302 mkfs.ext4 -L my-root /dev/sda2
2305 @cindex encrypted disk
2306 If you are instead planning to encrypt the root partition, you can use
2307 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2308 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2309 @code{man cryptsetup}} for more information). Assuming you want to
2310 store the root partition on @file{/dev/sda2}, the command sequence would
2311 be along these lines:
2314 cryptsetup luksFormat /dev/sda2
2315 cryptsetup open --type luks /dev/sda2 my-partition
2316 mkfs.ext4 -L my-root /dev/mapper/my-partition
2319 Once that is done, mount the target file system under @file{/mnt}
2320 with a command like (again, assuming @code{my-root} is the label of the
2324 mount LABEL=my-root /mnt
2327 Also mount any other file systems you would like to use on the target
2328 system relative to this path. If you have opted for @file{/boot/efi} as an
2329 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2330 found by @code{guix system init} afterwards.
2332 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2333 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2334 sure to initialize them with @command{mkswap}. Assuming you have one
2335 swap partition on @file{/dev/sda3}, you would run:
2342 Alternatively, you may use a swap file. For example, assuming that in
2343 the new system you want to use the file @file{/swapfile} as a swap file,
2344 you would run@footnote{This example will work for many types of file
2345 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2346 btrfs), the required steps may be different. For details, see the
2347 manual pages for @command{mkswap} and @command{swapon}.}:
2350 # This is 10 GiB of swap space. Adjust "count" to change the size.
2351 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2352 # For security, make the file readable and writable only by root.
2353 chmod 600 /mnt/swapfile
2354 mkswap /mnt/swapfile
2355 swapon /mnt/swapfile
2358 Note that if you have encrypted the root partition and created a swap
2359 file in its file system as described above, then the encryption also
2360 protects the swap file, just like any other file in that file system.
2362 @node Proceeding with the Installation
2363 @subsection Proceeding with the Installation
2365 With the target partitions ready and the target root mounted on
2366 @file{/mnt}, we're ready to go. First, run:
2369 herd start cow-store /mnt
2372 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2373 during the installation phase are written to the target disk on @file{/mnt}
2374 rather than kept in memory. This is necessary because the first phase of
2375 the @command{guix system init} command (see below) entails downloads or
2376 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2378 Next, you have to edit a file and
2379 provide the declaration of the operating system to be installed. To
2380 that end, the installation system comes with three text editors. We
2381 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2382 supports syntax highlighting and parentheses matching; other editors
2383 include GNU Zile (an Emacs clone), and
2384 nvi (a clone of the original BSD @command{vi} editor).
2385 We strongly recommend storing that file on the target root file system, say,
2386 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2387 configuration file once you have rebooted into the newly-installed system.
2389 @xref{Using the Configuration System}, for an overview of the
2390 configuration file. The example configurations discussed in that
2391 section are available under @file{/etc/configuration} in the
2392 installation image. Thus, to get started with a system configuration
2393 providing a graphical display server (a ``desktop'' system), you can run
2394 something along these lines:
2398 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2399 # nano /mnt/etc/config.scm
2402 You should pay attention to what your configuration file contains, and
2407 Make sure the @code{bootloader-configuration} form refers to the target
2408 you want to install GRUB on. It should mention @code{grub-bootloader} if
2409 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2410 for newer UEFI systems. For legacy systems, the @code{target} field
2411 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2412 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2413 currently mounted and a @code{file-system} entry is specified in your
2417 Be sure that your file system labels match the value of their respective
2418 @code{device} fields in your @code{file-system} configuration, assuming
2419 your @code{file-system} configuration uses the @code{file-system-label}
2420 procedure in its @code{device} field.
2423 If there are encrypted or RAID partitions, make sure to add a
2424 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2427 Once you are done preparing the configuration file, the new system must
2428 be initialized (remember that the target root file system is mounted
2432 guix system init /mnt/etc/config.scm /mnt
2436 This copies all the necessary files and installs GRUB on
2437 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2438 more information, @pxref{Invoking guix system}. This command may trigger
2439 downloads or builds of missing packages, which can take some time.
2441 Once that command has completed---and hopefully succeeded!---you can run
2442 @command{reboot} and boot into the new system. The @code{root} password
2443 in the new system is initially empty; other users' passwords need to be
2444 initialized by running the @command{passwd} command as @code{root},
2445 unless your configuration specifies otherwise
2446 (@pxref{user-account-password, user account passwords}).
2447 @xref{After System Installation}, for what's next!
2450 @node After System Installation
2451 @section After System Installation
2453 Success, you've now booted into Guix System! From then on, you can update the
2454 system whenever you want by running, say:
2458 sudo guix system reconfigure /etc/config.scm
2462 This builds a new system generation with the latest packages and services
2463 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2464 your system includes the latest security updates (@pxref{Security Updates}).
2466 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2468 @cindex sudo vs. @command{guix pull}
2469 Note that @command{sudo guix} runs your user's @command{guix} command and
2470 @emph{not} root's, because @command{sudo} leaves @env{PATH} unchanged. To
2471 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2473 The difference matters here, because @command{guix pull} updates
2474 the @command{guix} command and package definitions only for the user it is ran
2475 as. This means that if you choose to use @command{guix system reconfigure} in
2476 root's login shell, you'll need to @command{guix pull} separately.
2479 Join us on @code{#guix} on the Freenode IRC network or on
2480 @email{guix-devel@@gnu.org} to share your experience!
2483 @node Installing Guix in a VM
2484 @section Installing Guix in a Virtual Machine
2486 @cindex virtual machine, Guix System installation
2487 @cindex virtual private server (VPS)
2488 @cindex VPS (virtual private server)
2489 If you'd like to install Guix System in a virtual machine (VM) or on a
2490 virtual private server (VPS) rather than on your beloved machine, this
2493 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2494 disk image, follow these steps:
2498 First, retrieve and decompress the Guix system installation image as
2499 described previously (@pxref{USB Stick and DVD Installation}).
2502 Create a disk image that will hold the installed system. To make a
2503 qcow2-formatted disk image, use the @command{qemu-img} command:
2506 qemu-img create -f qcow2 guix-system.img 50G
2509 The resulting file will be much smaller than 50 GB (typically less than
2510 1 MB), but it will grow as the virtualized storage device is filled up.
2513 Boot the USB installation image in an VM:
2516 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2517 -nic user,model=virtio-net-pci -boot menu=on,order=d \
2518 -drive file=guix-system.img \
2519 -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
2522 @code{-enable-kvm} is optional, but significantly improves performance,
2523 @pxref{Running Guix in a VM}.
2526 You're now root in the VM, proceed with the installation process.
2527 @xref{Preparing for Installation}, and follow the instructions.
2530 Once installation is complete, you can boot the system that's on your
2531 @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
2534 @node Building the Installation Image
2535 @section Building the Installation Image
2537 @cindex installation image
2538 The installation image described above was built using the @command{guix
2539 system} command, specifically:
2542 guix system disk-image --file-system-type=iso9660 \
2543 gnu/system/install.scm
2546 Have a look at @file{gnu/system/install.scm} in the source tree,
2547 and see also @ref{Invoking guix system} for more information
2548 about the installation image.
2550 @section Building the Installation Image for ARM Boards
2552 Many ARM boards require a specific variant of the
2553 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2555 If you build a disk image and the bootloader is not available otherwise
2556 (on another boot drive etc), it's advisable to build an image that
2557 includes the bootloader, specifically:
2560 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2563 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2564 board, a list of possible boards will be printed.
2566 @c *********************************************************************
2567 @node Package Management
2568 @chapter Package Management
2571 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2572 remove software packages, without having to know about their build
2573 procedures or dependencies. Guix also goes beyond this obvious set of
2576 This chapter describes the main features of Guix, as well as the
2577 package management tools it provides. Along with the command-line
2578 interface described below (@pxref{Invoking guix package, @code{guix
2579 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2580 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2581 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2585 guix install emacs-guix
2589 * Features:: How Guix will make your life brighter.
2590 * Invoking guix package:: Package installation, removal, etc.
2591 * Substitutes:: Downloading pre-built binaries.
2592 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2593 * Invoking guix gc:: Running the garbage collector.
2594 * Invoking guix pull:: Fetching the latest Guix and distribution.
2595 * Channels:: Customizing the package collection.
2596 * Invoking guix time-machine:: Running an older revision of Guix.
2597 * Inferiors:: Interacting with another revision of Guix.
2598 * Invoking guix describe:: Display information about your Guix revision.
2599 * Invoking guix archive:: Exporting and importing store files.
2605 When using Guix, each package ends up in the @dfn{package store}, in its
2606 own directory---something that resembles
2607 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2609 Instead of referring to these directories, users have their own
2610 @dfn{profile}, which points to the packages that they actually want to
2611 use. These profiles are stored within each user's home directory, at
2612 @code{$HOME/.guix-profile}.
2614 For example, @code{alice} installs GCC 4.7.2. As a result,
2615 @file{/home/alice/.guix-profile/bin/gcc} points to
2616 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2617 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2618 simply continues to point to
2619 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2620 coexist on the same system without any interference.
2622 The @command{guix package} command is the central tool to manage
2623 packages (@pxref{Invoking guix package}). It operates on the per-user
2624 profiles, and can be used @emph{with normal user privileges}.
2626 @cindex transactions
2627 The command provides the obvious install, remove, and upgrade
2628 operations. Each invocation is actually a @emph{transaction}: either
2629 the specified operation succeeds, or nothing happens. Thus, if the
2630 @command{guix package} process is terminated during the transaction,
2631 or if a power outage occurs during the transaction, then the user's
2632 profile remains in its previous state, and remains usable.
2634 In addition, any package transaction may be @emph{rolled back}. So, if,
2635 for example, an upgrade installs a new version of a package that turns
2636 out to have a serious bug, users may roll back to the previous instance
2637 of their profile, which was known to work well. Similarly, the global
2638 system configuration on Guix is subject to
2639 transactional upgrades and roll-back
2640 (@pxref{Using the Configuration System}).
2642 All packages in the package store may be @emph{garbage-collected}.
2643 Guix can determine which packages are still referenced by user
2644 profiles, and remove those that are provably no longer referenced
2645 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2646 generations of their profile so that the packages they refer to can be
2649 @cindex reproducibility
2650 @cindex reproducible builds
2651 Guix takes a @dfn{purely functional} approach to package
2652 management, as described in the introduction (@pxref{Introduction}).
2653 Each @file{/gnu/store} package directory name contains a hash of all the
2654 inputs that were used to build that package---compiler, libraries, build
2655 scripts, etc. This direct correspondence allows users to make sure a
2656 given package installation matches the current state of their
2657 distribution. It also helps maximize @dfn{build reproducibility}:
2658 thanks to the isolated build environments that are used, a given build
2659 is likely to yield bit-identical files when performed on different
2660 machines (@pxref{Invoking guix-daemon, container}).
2663 This foundation allows Guix to support @dfn{transparent binary/source
2664 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2665 available from an external source---a @dfn{substitute}, Guix just
2666 downloads it and unpacks it;
2667 otherwise, it builds the package from source, locally
2668 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2669 reproducible, users do not have to trust servers that provide
2670 substitutes: they can force a local build and @emph{challenge} providers
2671 (@pxref{Invoking guix challenge}).
2673 Control over the build environment is a feature that is also useful for
2674 developers. The @command{guix environment} command allows developers of
2675 a package to quickly set up the right development environment for their
2676 package, without having to manually install the dependencies of the
2677 package into their profile (@pxref{Invoking guix environment}).
2679 @cindex replication, of software environments
2680 @cindex provenance tracking, of software artifacts
2681 All of Guix and its package definitions is version-controlled, and
2682 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2683 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2684 Guix instance on a different machine or at a later point in time, which in
2685 turn allows you to @emph{replicate complete software environments}, while
2686 retaining precise @dfn{provenance tracking} of the software.
2688 @node Invoking guix package
2689 @section Invoking @command{guix package}
2691 @cindex installing packages
2692 @cindex removing packages
2693 @cindex package installation
2694 @cindex package removal
2695 The @command{guix package} command is the tool that allows users to
2696 install, upgrade, and remove packages, as well as rolling back to
2697 previous configurations. It operates only on the user's own profile,
2698 and works with normal user privileges (@pxref{Features}). Its syntax
2702 guix package @var{options}
2705 @cindex transactions
2706 Primarily, @var{options} specifies the operations to be performed during
2707 the transaction. Upon completion, a new profile is created, but
2708 previous @dfn{generations} of the profile remain available, should the user
2711 For example, to remove @code{lua} and install @code{guile} and
2712 @code{guile-cairo} in a single transaction:
2715 guix package -r lua -i guile guile-cairo
2718 @cindex aliases, for @command{guix package}
2719 For your convenience, we also provide the following aliases:
2723 @command{guix search} is an alias for @command{guix package -s},
2725 @command{guix install} is an alias for @command{guix package -i},
2727 @command{guix remove} is an alias for @command{guix package -r},
2729 @command{guix upgrade} is an alias for @command{guix package -u},
2731 and @command{guix show} is an alias for @command{guix package --show=}.
2734 These aliases are less expressive than @command{guix package} and provide
2735 fewer options, so in some cases you'll probably want to use @command{guix
2738 @command{guix package} also supports a @dfn{declarative approach}
2739 whereby the user specifies the exact set of packages to be available and
2740 passes it @i{via} the @option{--manifest} option
2741 (@pxref{profile-manifest, @option{--manifest}}).
2744 For each user, a symlink to the user's default profile is automatically
2745 created in @file{$HOME/.guix-profile}. This symlink always points to the
2746 current generation of the user's default profile. Thus, users can add
2747 @file{$HOME/.guix-profile/bin} to their @env{PATH} environment
2748 variable, and so on.
2749 @cindex search paths
2750 If you are not using Guix System, consider adding the
2751 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2752 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2753 shells get all the right environment variable definitions:
2756 GUIX_PROFILE="$HOME/.guix-profile" ; \
2757 source "$HOME/.guix-profile/etc/profile"
2760 In a multi-user setup, user profiles are stored in a place registered as
2761 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2762 to (@pxref{Invoking guix gc}). That directory is normally
2763 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2764 @var{localstatedir} is the value passed to @code{configure} as
2765 @option{--localstatedir}, and @var{user} is the user name. The
2766 @file{per-user} directory is created when @command{guix-daemon} is
2767 started, and the @var{user} sub-directory is created by @command{guix
2770 The @var{options} can be among the following:
2774 @item --install=@var{package} @dots{}
2775 @itemx -i @var{package} @dots{}
2776 Install the specified @var{package}s.
2778 Each @var{package} may specify either a simple package name, such as
2779 @code{guile}, or a package name followed by an at-sign and version number,
2780 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2781 case, the newest version prefixed by @code{1.8} is selected).
2783 If no version number is specified, the
2784 newest available version will be selected. In addition, @var{package}
2785 may contain a colon, followed by the name of one of the outputs of the
2786 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
2787 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
2788 name (and optionally version) are searched for among the GNU
2789 distribution modules (@pxref{Package Modules}).
2791 @cindex propagated inputs
2792 Sometimes packages have @dfn{propagated inputs}: these are dependencies
2793 that automatically get installed along with the required package
2794 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
2795 @code{package} objects}, for information about propagated inputs in
2796 package definitions).
2798 @anchor{package-cmd-propagated-inputs}
2799 An example is the GNU MPC library: its C header files refer to those of
2800 the GNU MPFR library, which in turn refer to those of the GMP library.
2801 Thus, when installing MPC, the MPFR and GMP libraries also get installed
2802 in the profile; removing MPC also removes MPFR and GMP---unless they had
2803 also been explicitly installed by the user.
2805 Besides, packages sometimes rely on the definition of environment
2806 variables for their search paths (see explanation of
2807 @option{--search-paths} below). Any missing or possibly incorrect
2808 environment variable definitions are reported here.
2810 @item --install-from-expression=@var{exp}
2812 Install the package @var{exp} evaluates to.
2814 @var{exp} must be a Scheme expression that evaluates to a
2815 @code{<package>} object. This option is notably useful to disambiguate
2816 between same-named variants of a package, with expressions such as
2817 @code{(@@ (gnu packages base) guile-final)}.
2819 Note that this option installs the first output of the specified
2820 package, which may be insufficient when needing a specific output of a
2821 multiple-output package.
2823 @item --install-from-file=@var{file}
2824 @itemx -f @var{file}
2825 Install the package that the code within @var{file} evaluates to.
2827 As an example, @var{file} might contain a definition like this
2828 (@pxref{Defining Packages}):
2831 @include package-hello.scm
2834 Developers may find it useful to include such a @file{guix.scm} file
2835 in the root of their project source tree that can be used to test
2836 development snapshots and create reproducible development environments
2837 (@pxref{Invoking guix environment}).
2839 The @var{file} may also contain a JSON representation of one or more
2840 package definitions. Running @code{guix package -f} on
2841 @file{hello.json} with the following contents would result in installing
2842 the package @code{greeter} after building @code{myhello}:
2845 @verbatiminclude package-hello.json
2848 @item --remove=@var{package} @dots{}
2849 @itemx -r @var{package} @dots{}
2850 Remove the specified @var{package}s.
2852 As for @option{--install}, each @var{package} may specify a version number
2853 and/or output name in addition to the package name. For instance,
2854 @samp{-r glibc:debug} would remove the @code{debug} output of
2857 @item --upgrade[=@var{regexp} @dots{}]
2858 @itemx -u [@var{regexp} @dots{}]
2859 @cindex upgrading packages
2860 Upgrade all the installed packages. If one or more @var{regexp}s are
2861 specified, upgrade only installed packages whose name matches a
2862 @var{regexp}. Also see the @option{--do-not-upgrade} option below.
2864 Note that this upgrades package to the latest version of packages found
2865 in the distribution currently installed. To update your distribution,
2866 you should regularly run @command{guix pull} (@pxref{Invoking guix
2869 @item --do-not-upgrade[=@var{regexp} @dots{}]
2870 When used together with the @option{--upgrade} option, do @emph{not}
2871 upgrade any packages whose name matches a @var{regexp}. For example, to
2872 upgrade all packages in the current profile except those containing the
2873 substring ``emacs'':
2876 $ guix package --upgrade . --do-not-upgrade emacs
2879 @item @anchor{profile-manifest}--manifest=@var{file}
2880 @itemx -m @var{file}
2881 @cindex profile declaration
2882 @cindex profile manifest
2883 Create a new generation of the profile from the manifest object
2884 returned by the Scheme code in @var{file}. This option can be repeated
2885 several times, in which case the manifests are concatenated.
2887 This allows you to @emph{declare} the profile's contents rather than
2888 constructing it through a sequence of @option{--install} and similar
2889 commands. The advantage is that @var{file} can be put under version
2890 control, copied to different machines to reproduce the same profile, and
2893 @c FIXME: Add reference to (guix profile) documentation when available.
2894 @var{file} must return a @dfn{manifest} object, which is roughly a list
2897 @findex packages->manifest
2899 (use-package-modules guile emacs)
2904 ;; Use a specific package output.
2905 (list guile-2.0 "debug")))
2908 @findex specifications->manifest
2909 In this example we have to know which modules define the @code{emacs}
2910 and @code{guile-2.0} variables to provide the right
2911 @code{use-package-modules} line, which can be cumbersome. We can
2912 instead provide regular package specifications and let
2913 @code{specifications->manifest} look up the corresponding package
2917 (specifications->manifest
2918 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2922 @cindex rolling back
2923 @cindex undoing transactions
2924 @cindex transactions, undoing
2925 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2926 the last transaction.
2928 When combined with options such as @option{--install}, roll back occurs
2929 before any other actions.
2931 When rolling back from the first generation that actually contains
2932 installed packages, the profile is made to point to the @dfn{zeroth
2933 generation}, which contains no files apart from its own metadata.
2935 After having rolled back, installing, removing, or upgrading packages
2936 overwrites previous future generations. Thus, the history of the
2937 generations in a profile is always linear.
2939 @item --switch-generation=@var{pattern}
2940 @itemx -S @var{pattern}
2942 Switch to a particular generation defined by @var{pattern}.
2944 @var{pattern} may be either a generation number or a number prefixed
2945 with ``+'' or ``-''. The latter means: move forward/backward by a
2946 specified number of generations. For example, if you want to return to
2947 the latest generation after @option{--roll-back}, use
2948 @option{--switch-generation=+1}.
2950 The difference between @option{--roll-back} and
2951 @option{--switch-generation=-1} is that @option{--switch-generation} will
2952 not make a zeroth generation, so if a specified generation does not
2953 exist, the current generation will not be changed.
2955 @item --search-paths[=@var{kind}]
2956 @cindex search paths
2957 Report environment variable definitions, in Bash syntax, that may be
2958 needed in order to use the set of installed packages. These environment
2959 variables are used to specify @dfn{search paths} for files used by some
2960 of the installed packages.
2962 For example, GCC needs the @env{CPATH} and @env{LIBRARY_PATH}
2963 environment variables to be defined so it can look for headers and
2964 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2965 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2966 library are installed in the profile, then @option{--search-paths} will
2967 suggest setting these variables to @file{@var{profile}/include} and
2968 @file{@var{profile}/lib}, respectively.
2970 The typical use case is to define these environment variables in the
2974 $ eval `guix package --search-paths`
2977 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2978 meaning that the returned environment variable definitions will either
2979 be exact settings, or prefixes or suffixes of the current value of these
2980 variables. When omitted, @var{kind} defaults to @code{exact}.
2982 This option can also be used to compute the @emph{combined} search paths
2983 of several profiles. Consider this example:
2986 $ guix package -p foo -i guile
2987 $ guix package -p bar -i guile-json
2988 $ guix package -p foo -p bar --search-paths
2991 The last command above reports about the @env{GUILE_LOAD_PATH}
2992 variable, even though, taken individually, neither @file{foo} nor
2993 @file{bar} would lead to that recommendation.
2996 @item --profile=@var{profile}
2997 @itemx -p @var{profile}
2998 Use @var{profile} instead of the user's default profile.
3000 @var{profile} must be the name of a file that will be created upon
3001 completion. Concretely, @var{profile} will be a mere symbolic link
3002 (``symlink'') pointing to the actual profile where packages are
3006 $ guix install hello -p ~/code/my-profile
3008 $ ~/code/my-profile/bin/hello
3012 All it takes to get rid of the profile is to remove this symlink and its
3013 siblings that point to specific generations:
3016 $ rm ~/code/my-profile ~/code/my-profile-*-link
3019 @item --list-profiles
3020 List all the user's profiles:
3023 $ guix package --list-profiles
3024 /home/charlie/.guix-profile
3025 /home/charlie/code/my-profile
3026 /home/charlie/code/devel-profile
3027 /home/charlie/tmp/test
3030 When running as root, list all the profiles of all the users.
3032 @cindex collisions, in a profile
3033 @cindex colliding packages in profiles
3034 @cindex profile collisions
3035 @item --allow-collisions
3036 Allow colliding packages in the new profile. Use at your own risk!
3038 By default, @command{guix package} reports as an error @dfn{collisions}
3039 in the profile. Collisions happen when two or more different versions
3040 or variants of a given package end up in the profile.
3043 Use the bootstrap Guile to build the profile. This option is only
3044 useful to distribution developers.
3048 In addition to these actions, @command{guix package} supports the
3049 following options to query the current state of a profile, or the
3050 availability of packages:
3054 @item --search=@var{regexp}
3055 @itemx -s @var{regexp}
3056 @anchor{guix-search}
3057 @cindex searching for packages
3058 List the available packages whose name, synopsis, or description matches
3059 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
3060 Print all the metadata of matching packages in
3061 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
3062 GNU recutils manual}).
3064 This allows specific fields to be extracted using the @command{recsel}
3065 command, for instance:
3068 $ guix package -s malloc | recsel -p name,version,relevance
3082 Similarly, to show the name of all the packages available under the
3083 terms of the GNU@tie{}LGPL version 3:
3086 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
3093 It is also possible to refine search results using several @code{-s} flags to
3094 @command{guix package}, or several arguments to @command{guix search}. For
3095 example, the following command returns a list of board games (this time using
3096 the @command{guix search} alias):
3099 $ guix search '\<board\>' game | recsel -p name
3104 If we were to omit @code{-s game}, we would also get software packages
3105 that deal with printed circuit boards; removing the angle brackets
3106 around @code{board} would further add packages that have to do with
3109 And now for a more elaborate example. The following command searches
3110 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
3111 libraries, and prints the name and synopsis of the matching packages:
3114 $ guix search crypto library | \
3115 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3119 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3120 information on @dfn{selection expressions} for @code{recsel -e}.
3122 @item --show=@var{package}
3123 Show details about @var{package}, taken from the list of available packages, in
3124 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3128 $ guix package --show=python | recsel -p name,version
3136 You may also specify the full name of a package to only get details about a
3137 specific version of it (this time using the @command{guix show} alias):
3139 $ guix show python@@3.4 | recsel -p name,version
3146 @item --list-installed[=@var{regexp}]
3147 @itemx -I [@var{regexp}]
3148 List the currently installed packages in the specified profile, with the
3149 most recently installed packages shown last. When @var{regexp} is
3150 specified, list only installed packages whose name matches @var{regexp}.
3152 For each installed package, print the following items, separated by
3153 tabs: the package name, its version string, the part of the package that
3154 is installed (for instance, @code{out} for the default output,
3155 @code{include} for its headers, etc.), and the path of this package in
3158 @item --list-available[=@var{regexp}]
3159 @itemx -A [@var{regexp}]
3160 List packages currently available in the distribution for this system
3161 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3162 available packages whose name matches @var{regexp}.
3164 For each package, print the following items separated by tabs: its name,
3165 its version string, the parts of the package (@pxref{Packages with
3166 Multiple Outputs}), and the source location of its definition.
3168 @item --list-generations[=@var{pattern}]
3169 @itemx -l [@var{pattern}]
3171 Return a list of generations along with their creation dates; for each
3172 generation, show the installed packages, with the most recently
3173 installed packages shown last. Note that the zeroth generation is never
3176 For each installed package, print the following items, separated by
3177 tabs: the name of a package, its version string, the part of the package
3178 that is installed (@pxref{Packages with Multiple Outputs}), and the
3179 location of this package in the store.
3181 When @var{pattern} is used, the command returns only matching
3182 generations. Valid patterns include:
3185 @item @emph{Integers and comma-separated integers}. Both patterns denote
3186 generation numbers. For instance, @option{--list-generations=1} returns
3189 And @option{--list-generations=1,8,2} outputs three generations in the
3190 specified order. Neither spaces nor trailing commas are allowed.
3192 @item @emph{Ranges}. @option{--list-generations=2..9} prints the
3193 specified generations and everything in between. Note that the start of
3194 a range must be smaller than its end.
3196 It is also possible to omit the endpoint. For example,
3197 @option{--list-generations=2..}, returns all generations starting from the
3200 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3201 or months by passing an integer along with the first letter of the
3202 duration. For example, @option{--list-generations=20d} lists generations
3203 that are up to 20 days old.
3206 @item --delete-generations[=@var{pattern}]
3207 @itemx -d [@var{pattern}]
3208 When @var{pattern} is omitted, delete all generations except the current
3211 This command accepts the same patterns as @option{--list-generations}.
3212 When @var{pattern} is specified, delete the matching generations. When
3213 @var{pattern} specifies a duration, generations @emph{older} than the
3214 specified duration match. For instance, @option{--delete-generations=1m}
3215 deletes generations that are more than one month old.
3217 If the current generation matches, it is @emph{not} deleted. Also, the
3218 zeroth generation is never deleted.
3220 Note that deleting generations prevents rolling back to them.
3221 Consequently, this command must be used with care.
3225 Finally, since @command{guix package} may actually start build
3226 processes, it supports all the common build options (@pxref{Common Build
3227 Options}). It also supports package transformation options, such as
3228 @option{--with-source} (@pxref{Package Transformation Options}).
3229 However, note that package transformations are lost when upgrading; to
3230 preserve transformations across upgrades, you should define your own
3231 package variant in a Guile module and add it to @env{GUIX_PACKAGE_PATH}
3232 (@pxref{Defining Packages}).
3235 @section Substitutes
3238 @cindex pre-built binaries
3239 Guix supports transparent source/binary deployment, which means that it
3240 can either build things locally, or download pre-built items from a
3241 server, or both. We call these pre-built items @dfn{substitutes}---they
3242 are substitutes for local build results. In many cases, downloading a
3243 substitute is much faster than building things locally.
3245 Substitutes can be anything resulting from a derivation build
3246 (@pxref{Derivations}). Of course, in the common case, they are
3247 pre-built package binaries, but source tarballs, for instance, which
3248 also result from derivation builds, can be available as substitutes.
3251 * Official Substitute Server:: One particular source of substitutes.
3252 * Substitute Server Authorization:: How to enable or disable substitutes.
3253 * Substitute Authentication:: How Guix verifies substitutes.
3254 * Proxy Settings:: How to get substitutes via proxy.
3255 * Substitution Failure:: What happens when substitution fails.
3256 * On Trusting Binaries:: How can you trust that binary blob?
3259 @node Official Substitute Server
3260 @subsection Official Substitute Server
3263 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3264 that builds packages from Guix continuously for some
3265 architectures, and makes them available as substitutes. This is the
3266 default source of substitutes; it can be overridden by passing the
3267 @option{--substitute-urls} option either to @command{guix-daemon}
3268 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3269 or to client tools such as @command{guix package}
3270 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3273 Substitute URLs can be either HTTP or HTTPS.
3274 HTTPS is recommended because communications are encrypted; conversely,
3275 using HTTP makes all communications visible to an eavesdropper, who
3276 could use the information gathered to determine, for instance, whether
3277 your system has unpatched security vulnerabilities.
3279 Substitutes from the official build farm are enabled by default when
3280 using Guix System (@pxref{GNU Distribution}). However,
3281 they are disabled by default when using Guix on a foreign distribution,
3282 unless you have explicitly enabled them via one of the recommended
3283 installation steps (@pxref{Installation}). The following paragraphs
3284 describe how to enable or disable substitutes for the official build
3285 farm; the same procedure can also be used to enable substitutes for any
3286 other substitute server.
3288 @node Substitute Server Authorization
3289 @subsection Substitute Server Authorization
3292 @cindex substitutes, authorization thereof
3293 @cindex access control list (ACL), for substitutes
3294 @cindex ACL (access control list), for substitutes
3295 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3297 must add its public key to the access control list (ACL) of archive
3298 imports, using the @command{guix archive} command (@pxref{Invoking guix
3299 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3300 be compromised and to serve genuine substitutes.
3302 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3303 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3304 the installation prefix of Guix. If you installed Guix from source,
3305 make sure you checked the GPG signature of
3306 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3307 Then, you can run something like this:
3310 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3313 Once this is in place, the output of a command like @code{guix build}
3314 should change from something like:
3317 $ guix build emacs --dry-run
3318 The following derivations would be built:
3319 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3320 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3321 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3322 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3330 $ guix build emacs --dry-run
3331 112.3 MB would be downloaded:
3332 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3333 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3334 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3335 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3340 The text changed from ``The following derivations would be built'' to
3341 ``112.3 MB would be downloaded''. This indicates that substitutes from
3342 @code{@value{SUBSTITUTE-SERVER}} are usable and will be downloaded, when
3343 possible, for future builds.
3345 @cindex substitutes, how to disable
3346 The substitute mechanism can be disabled globally by running
3347 @code{guix-daemon} with @option{--no-substitutes} (@pxref{Invoking
3348 guix-daemon}). It can also be disabled temporarily by passing the
3349 @option{--no-substitutes} option to @command{guix package},
3350 @command{guix build}, and other command-line tools.
3352 @node Substitute Authentication
3353 @subsection Substitute Authentication
3355 @cindex digital signatures
3356 Guix detects and raises an error when attempting to use a substitute
3357 that has been tampered with. Likewise, it ignores substitutes that are
3358 not signed, or that are not signed by one of the keys listed in the ACL.
3360 There is one exception though: if an unauthorized server provides
3361 substitutes that are @emph{bit-for-bit identical} to those provided by
3362 an authorized server, then the unauthorized server becomes eligible for
3363 downloads. For example, assume we have chosen two substitute servers
3367 --substitute-urls="https://a.example.org https://b.example.org"
3371 @cindex reproducible builds
3372 If the ACL contains only the key for @samp{b.example.org}, and if
3373 @samp{a.example.org} happens to serve the @emph{exact same} substitutes,
3374 then Guix will download substitutes from @samp{a.example.org} because it
3375 comes first in the list and can be considered a mirror of
3376 @samp{b.example.org}. In practice, independent build machines usually
3377 produce the same binaries, thanks to bit-reproducible builds (see
3380 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3381 (in other words, the server is not authenticated), contrary to what
3382 HTTPS clients such as Web browsers usually do. This is because Guix
3383 authenticates substitute information itself, as explained above, which
3384 is what we care about (whereas X.509 certificates are about
3385 authenticating bindings between domain names and public keys).
3387 @node Proxy Settings
3388 @subsection Proxy Settings
3392 Substitutes are downloaded over HTTP or HTTPS. The @env{http_proxy} and
3393 @env{https_proxy} environment variables can be set in the environment of
3394 @command{guix-daemon} and are honored for downloads of substitutes.
3395 Note that the value of those environment variables in the environment
3396 where @command{guix build}, @command{guix package}, and other client
3397 commands are run has @emph{absolutely no effect}.
3399 @node Substitution Failure
3400 @subsection Substitution Failure
3402 Even when a substitute for a derivation is available, sometimes the
3403 substitution attempt will fail. This can happen for a variety of
3404 reasons: the substitute server might be offline, the substitute may
3405 recently have been deleted, the connection might have been interrupted,
3408 When substitutes are enabled and a substitute for a derivation is
3409 available, but the substitution attempt fails, Guix will attempt to
3410 build the derivation locally depending on whether or not
3411 @option{--fallback} was given (@pxref{fallback-option,, common build
3412 option @option{--fallback}}). Specifically, if @option{--fallback} was
3413 omitted, then no local build will be performed, and the derivation is
3414 considered to have failed. However, if @option{--fallback} was given,
3415 then Guix will attempt to build the derivation locally, and the success
3416 or failure of the derivation depends on the success or failure of the
3417 local build. Note that when substitutes are disabled or no substitute
3418 is available for the derivation in question, a local build will
3419 @emph{always} be performed, regardless of whether or not
3420 @option{--fallback} was given.
3422 To get an idea of how many substitutes are available right now, you can
3423 try running the @command{guix weather} command (@pxref{Invoking guix
3424 weather}). This command provides statistics on the substitutes provided
3427 @node On Trusting Binaries
3428 @subsection On Trusting Binaries
3430 @cindex trust, of pre-built binaries
3431 Today, each individual's control over their own computing is at the
3432 mercy of institutions, corporations, and groups with enough power and
3433 determination to subvert the computing infrastructure and exploit its
3434 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3435 convenient, we encourage users to also build on their own, or even run
3436 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3437 interesting target. One way to help is by publishing the software you
3438 build using @command{guix publish} so that others have one more choice
3439 of server to download substitutes from (@pxref{Invoking guix publish}).
3441 Guix has the foundations to maximize build reproducibility
3442 (@pxref{Features}). In most cases, independent builds of a given
3443 package or derivation should yield bit-identical results. Thus, through
3444 a diverse set of independent package builds, we can strengthen the
3445 integrity of our systems. The @command{guix challenge} command aims to
3446 help users assess substitute servers, and to assist developers in
3447 finding out about non-deterministic package builds (@pxref{Invoking guix
3448 challenge}). Similarly, the @option{--check} option of @command{guix
3449 build} allows users to check whether previously-installed substitutes
3450 are genuine by rebuilding them locally (@pxref{build-check,
3451 @command{guix build --check}}).
3453 In the future, we want Guix to have support to publish and retrieve
3454 binaries to/from other users, in a peer-to-peer fashion. If you would
3455 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3457 @node Packages with Multiple Outputs
3458 @section Packages with Multiple Outputs
3460 @cindex multiple-output packages
3461 @cindex package outputs
3464 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3465 source package leads to exactly one directory in the store. When running
3466 @command{guix install glibc}, one installs the default output of the
3467 GNU libc package; the default output is called @code{out}, but its name
3468 can be omitted as shown in this command. In this particular case, the
3469 default output of @code{glibc} contains all the C header files, shared
3470 libraries, static libraries, Info documentation, and other supporting
3473 Sometimes it is more appropriate to separate the various types of files
3474 produced from a single source package into separate outputs. For
3475 instance, the GLib C library (used by GTK+ and related packages)
3476 installs more than 20 MiB of reference documentation as HTML pages.
3477 To save space for users who do not need it, the documentation goes to a
3478 separate output, called @code{doc}. To install the main GLib output,
3479 which contains everything but the documentation, one would run:
3485 @cindex documentation
3486 The command to install its documentation is:
3489 guix install glib:doc
3492 Some packages install programs with different ``dependency footprints''.
3493 For instance, the WordNet package installs both command-line tools and
3494 graphical user interfaces (GUIs). The former depend solely on the C
3495 library, whereas the latter depend on Tcl/Tk and the underlying X
3496 libraries. In this case, we leave the command-line tools in the default
3497 output, whereas the GUIs are in a separate output. This allows users
3498 who do not need the GUIs to save space. The @command{guix size} command
3499 can help find out about such situations (@pxref{Invoking guix size}).
3500 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3502 There are several such multiple-output packages in the GNU distribution.
3503 Other conventional output names include @code{lib} for libraries and
3504 possibly header files, @code{bin} for stand-alone programs, and
3505 @code{debug} for debugging information (@pxref{Installing Debugging
3506 Files}). The outputs of a packages are listed in the third column of
3507 the output of @command{guix package --list-available} (@pxref{Invoking
3511 @node Invoking guix gc
3512 @section Invoking @command{guix gc}
3514 @cindex garbage collector
3516 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3517 The @command{guix gc} command allows users to explicitly run the garbage
3518 collector to reclaim space from the @file{/gnu/store} directory. It is
3519 the @emph{only} way to remove files from @file{/gnu/store}---removing
3520 files or directories manually may break it beyond repair!
3523 @cindex garbage collector roots
3524 The garbage collector has a set of known @dfn{roots}: any file under
3525 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3526 cannot be deleted; any other file is considered @dfn{dead} and may be
3527 deleted. The set of garbage collector roots (``GC roots'' for short)
3528 includes default user profiles; by default, the symlinks under
3529 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3530 added with @command{guix build --root}, for example (@pxref{Invoking
3531 guix build}). The @command{guix gc --list-roots} command lists them.
3533 Prior to running @code{guix gc --collect-garbage} to make space, it is
3534 often useful to remove old generations from user profiles; that way, old
3535 package builds referenced by those generations can be reclaimed. This
3536 is achieved by running @code{guix package --delete-generations}
3537 (@pxref{Invoking guix package}).
3539 Our recommendation is to run a garbage collection periodically, or when
3540 you are short on disk space. For instance, to guarantee that at least
3541 5@tie{}GB are available on your disk, simply run:
3547 It is perfectly safe to run as a non-interactive periodic job
3548 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3549 Running @command{guix gc} with no arguments will collect as
3550 much garbage as it can, but that is often inconvenient: you may find
3551 yourself having to rebuild or re-download software that is ``dead'' from
3552 the GC viewpoint but that is necessary to build other pieces of
3553 software---e.g., the compiler tool chain.
3555 The @command{guix gc} command has three modes of operation: it can be
3556 used to garbage-collect any dead files (the default), to delete specific
3557 files (the @option{--delete} option), to print garbage-collector
3558 information, or for more advanced queries. The garbage collection
3559 options are as follows:
3562 @item --collect-garbage[=@var{min}]
3563 @itemx -C [@var{min}]
3564 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3565 sub-directories. This is the default operation when no option is
3568 When @var{min} is given, stop once @var{min} bytes have been collected.
3569 @var{min} may be a number of bytes, or it may include a unit as a
3570 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3571 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3573 When @var{min} is omitted, collect all the garbage.
3575 @item --free-space=@var{free}
3576 @itemx -F @var{free}
3577 Collect garbage until @var{free} space is available under
3578 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3579 as @code{500MiB}, as described above.
3581 When @var{free} or more is already available in @file{/gnu/store}, do
3582 nothing and exit immediately.
3584 @item --delete-generations[=@var{duration}]
3585 @itemx -d [@var{duration}]
3586 Before starting the garbage collection process, delete all the generations
3587 older than @var{duration}, for all the user profiles; when run as root, this
3588 applies to all the profiles @emph{of all the users}.
3590 For example, this command deletes all the generations of all your profiles
3591 that are older than 2 months (except generations that are current), and then
3592 proceeds to free space until at least 10 GiB are available:
3595 guix gc -d 2m -F 10G
3600 Attempt to delete all the store files and directories specified as
3601 arguments. This fails if some of the files are not in the store, or if
3602 they are still live.
3604 @item --list-failures
3605 List store items corresponding to cached build failures.
3607 This prints nothing unless the daemon was started with
3608 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3609 @option{--cache-failures}}).
3612 List the GC roots owned by the user; when run as root, list @emph{all} the GC
3616 List store items in use by currently running processes. These store
3617 items are effectively considered GC roots: they cannot be deleted.
3619 @item --clear-failures
3620 Remove the specified store items from the failed-build cache.
3622 Again, this option only makes sense when the daemon is started with
3623 @option{--cache-failures}. Otherwise, it does nothing.
3626 Show the list of dead files and directories still present in the
3627 store---i.e., files and directories no longer reachable from any root.
3630 Show the list of live store files and directories.
3634 In addition, the references among existing store files can be queried:
3640 @cindex package dependencies
3641 List the references (respectively, the referrers) of store files given
3647 List the requisites of the store files passed as arguments. Requisites
3648 include the store files themselves, their references, and the references
3649 of these, recursively. In other words, the returned list is the
3650 @dfn{transitive closure} of the store files.
3652 @xref{Invoking guix size}, for a tool to profile the size of the closure
3653 of an element. @xref{Invoking guix graph}, for a tool to visualize
3654 the graph of references.
3658 Return the derivation(s) leading to the given store items
3659 (@pxref{Derivations}).
3661 For example, this command:
3664 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3668 returns the @file{.drv} file(s) leading to the @code{emacs} package
3669 installed in your profile.
3671 Note that there may be zero matching @file{.drv} files, for instance
3672 because these files have been garbage-collected. There can also be more
3673 than one matching @file{.drv} due to fixed-output derivations.
3676 Lastly, the following options allow you to check the integrity of the
3677 store and to control disk usage.
3681 @item --verify[=@var{options}]
3682 @cindex integrity, of the store
3683 @cindex integrity checking
3684 Verify the integrity of the store.
3686 By default, make sure that all the store items marked as valid in the
3687 database of the daemon actually exist in @file{/gnu/store}.
3689 When provided, @var{options} must be a comma-separated list containing one
3690 or more of @code{contents} and @code{repair}.
3692 When passing @option{--verify=contents}, the daemon computes the
3693 content hash of each store item and compares it against its hash in the
3694 database. Hash mismatches are reported as data corruptions. Because it
3695 traverses @emph{all the files in the store}, this command can take a
3696 long time, especially on systems with a slow disk drive.
3698 @cindex repairing the store
3699 @cindex corruption, recovering from
3700 Using @option{--verify=repair} or @option{--verify=contents,repair}
3701 causes the daemon to try to repair corrupt store items by fetching
3702 substitutes for them (@pxref{Substitutes}). Because repairing is not
3703 atomic, and thus potentially dangerous, it is available only to the
3704 system administrator. A lightweight alternative, when you know exactly
3705 which items in the store are corrupt, is @command{guix build --repair}
3706 (@pxref{Invoking guix build}).
3709 @cindex deduplication
3710 Optimize the store by hard-linking identical files---this is
3711 @dfn{deduplication}.
3713 The daemon performs deduplication after each successful build or archive
3714 import, unless it was started with @option{--disable-deduplication}
3715 (@pxref{Invoking guix-daemon, @option{--disable-deduplication}}). Thus,
3716 this option is primarily useful when the daemon was running with
3717 @option{--disable-deduplication}.
3721 @node Invoking guix pull
3722 @section Invoking @command{guix pull}
3724 @cindex upgrading Guix
3725 @cindex updating Guix
3726 @cindex @command{guix pull}
3728 @cindex security, @command{guix pull}
3729 @cindex authenticity, of code obtained with @command{guix pull}
3730 Packages are installed or upgraded to the latest version available in
3731 the distribution currently available on your local machine. To update
3732 that distribution, along with the Guix tools, you must run @command{guix
3733 pull}: the command downloads the latest Guix source code and package
3734 descriptions, and deploys it. Source code is downloaded from a
3735 @uref{https://git-scm.com, Git} repository, by default the official
3736 GNU@tie{}Guix repository, though this can be customized. @command{guix
3737 pull} ensures that the code it downloads is @emph{authentic} by
3738 verifying that commits are signed by Guix developers.
3740 Specifically, @command{guix pull} downloads code from the @dfn{channels}
3741 (@pxref{Channels}) specified by one of the followings, in this order:
3745 the @option{--channels} option;
3747 the user's @file{~/.config/guix/channels.scm} file;
3749 the system-wide @file{/etc/guix/channels.scm} file;
3751 the built-in default channels specified in the @code{%default-channels}
3755 On completion, @command{guix package} will use packages and package
3756 versions from this just-retrieved copy of Guix. Not only that, but all
3757 the Guix commands and Scheme modules will also be taken from that latest
3758 version. New @command{guix} sub-commands added by the update also
3761 Any user can update their Guix copy using @command{guix pull}, and the
3762 effect is limited to the user who ran @command{guix pull}. For
3763 instance, when user @code{root} runs @command{guix pull}, this has no
3764 effect on the version of Guix that user @code{alice} sees, and vice
3767 The result of running @command{guix pull} is a @dfn{profile} available
3768 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3769 make sure to add it to the beginning of your search path so that you use
3770 the latest version, and similarly for the Info manual
3771 (@pxref{Documentation}):
3774 export PATH="$HOME/.config/guix/current/bin:$PATH"
3775 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3778 The @option{--list-generations} or @option{-l} option lists past generations
3779 produced by @command{guix pull}, along with details about their provenance:
3783 Generation 1 Jun 10 2018 00:18:18
3785 repository URL: https://git.savannah.gnu.org/git/guix.git
3786 branch: origin/master
3787 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
3789 Generation 2 Jun 11 2018 11:02:49
3791 repository URL: https://git.savannah.gnu.org/git/guix.git
3792 branch: origin/master
3793 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
3794 2 new packages: keepalived, libnfnetlink
3795 6 packages upgraded: emacs-nix-mode@@2.0.4,
3796 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
3797 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
3799 Generation 3 Jun 13 2018 23:31:07 (current)
3801 repository URL: https://git.savannah.gnu.org/git/guix.git
3802 branch: origin/master
3803 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
3804 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
3805 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
3808 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
3809 describe the current status of Guix.
3811 This @code{~/.config/guix/current} profile works exactly like the profiles
3812 created by @command{guix package} (@pxref{Invoking guix package}). That
3813 is, you can list generations, roll back to the previous
3814 generation---i.e., the previous Guix---and so on:
3817 $ guix pull --roll-back
3818 switched from generation 3 to 2
3819 $ guix pull --delete-generations=1
3820 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3823 You can also use @command{guix package} (@pxref{Invoking guix package})
3824 to manage the profile by naming it explicitly:
3826 $ guix package -p ~/.config/guix/current --roll-back
3827 switched from generation 3 to 2
3828 $ guix package -p ~/.config/guix/current --delete-generations=1
3829 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3832 The @command{guix pull} command is usually invoked with no arguments,
3833 but it supports the following options:
3836 @item --url=@var{url}
3837 @itemx --commit=@var{commit}
3838 @itemx --branch=@var{branch}
3839 Download code for the @code{guix} channel from the specified @var{url}, at the
3840 given @var{commit} (a valid Git commit ID represented as a hexadecimal
3841 string), or @var{branch}.
3843 @cindex @file{channels.scm}, configuration file
3844 @cindex configuration file for channels
3845 These options are provided for convenience, but you can also specify your
3846 configuration in the @file{~/.config/guix/channels.scm} file or using the
3847 @option{--channels} option (see below).
3849 @item --channels=@var{file}
3850 @itemx -C @var{file}
3851 Read the list of channels from @var{file} instead of
3852 @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
3853 @var{file} must contain Scheme code that
3854 evaluates to a list of channel objects. @xref{Channels}, for more
3857 @cindex channel news
3860 Display the list of packages added or upgraded since the previous
3861 generation, as well as, occasionally, news written by channel authors
3862 for their users (@pxref{Channels, Writing Channel News}).
3864 The package information is the same as displayed upon @command{guix
3865 pull} completion, but without ellipses; it is also similar to the output
3866 of @command{guix pull -l} for the last generation (see below).
3868 @item --list-generations[=@var{pattern}]
3869 @itemx -l [@var{pattern}]
3870 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
3871 is provided, the subset of generations that match @var{pattern}.
3872 The syntax of @var{pattern} is the same as with @code{guix package
3873 --list-generations} (@pxref{Invoking guix package}).
3876 @cindex rolling back
3877 @cindex undoing transactions
3878 @cindex transactions, undoing
3879 Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
3880 undo the last transaction.
3882 @item --switch-generation=@var{pattern}
3883 @itemx -S @var{pattern}
3885 Switch to a particular generation defined by @var{pattern}.
3887 @var{pattern} may be either a generation number or a number prefixed
3888 with ``+'' or ``-''. The latter means: move forward/backward by a
3889 specified number of generations. For example, if you want to return to
3890 the latest generation after @option{--roll-back}, use
3891 @option{--switch-generation=+1}.
3893 @item --delete-generations[=@var{pattern}]
3894 @itemx -d [@var{pattern}]
3895 When @var{pattern} is omitted, delete all generations except the current
3898 This command accepts the same patterns as @option{--list-generations}.
3899 When @var{pattern} is specified, delete the matching generations. When
3900 @var{pattern} specifies a duration, generations @emph{older} than the
3901 specified duration match. For instance, @option{--delete-generations=1m}
3902 deletes generations that are more than one month old.
3904 If the current generation matches, it is @emph{not} deleted.
3906 Note that deleting generations prevents rolling back to them.
3907 Consequently, this command must be used with care.
3909 @xref{Invoking guix describe}, for a way to display information about the
3910 current generation only.
3912 @item --profile=@var{profile}
3913 @itemx -p @var{profile}
3914 Use @var{profile} instead of @file{~/.config/guix/current}.
3918 Show which channel commit(s) would be used and what would be built or
3919 substituted but do not actually do it.
3921 @item --allow-downgrades
3922 Allow pulling older or unrelated revisions of channels than those
3925 @cindex downgrade attacks, protection against
3926 By default, @command{guix pull} protects against so-called ``downgrade
3927 attacks'' whereby the Git repository of a channel would be reset to an
3928 earlier or unrelated revision of itself, potentially leading you to
3929 install older, known-vulnerable versions of software packages.
3932 Make sure you understand its security implications before using
3933 @option{--allow-downgrades}.
3936 @item --disable-authentication
3937 Allow pulling channel code without authenticating it.
3939 @cindex authentication, of channel code
3940 By default, @command{guix pull} authenticates code downloaded from
3941 channels by verifying that its commits are signed by authorized
3942 developers, and raises an error if this is not the case. This option
3943 instructs it to not perform any such verification.
3946 Make sure you understand its security implications before using
3947 @option{--disable-authentication}.
3950 @item --system=@var{system}
3951 @itemx -s @var{system}
3952 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3953 the system type of the build host.
3956 Use the bootstrap Guile to build the latest Guix. This option is only
3957 useful to Guix developers.
3960 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
3961 repository and branch to pull from, as well as @emph{additional} repositories
3962 containing package modules that should be deployed. @xref{Channels}, for more
3965 In addition, @command{guix pull} supports all the common build options
3966 (@pxref{Common Build Options}).
3972 @cindex @file{channels.scm}, configuration file
3973 @cindex configuration file for channels
3974 @cindex @command{guix pull}, configuration file
3975 @cindex configuration of @command{guix pull}
3976 Guix and its package collection are updated by running @command{guix pull}
3977 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
3978 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
3979 customized by defining @dfn{channels} in the
3980 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
3981 of a Git repository to be deployed, and @command{guix pull} can be instructed
3982 to pull from one or more channels. In other words, channels can be used
3983 to @emph{customize} and to @emph{extend} Guix, as we will see below.
3984 Before that, some security considerations.
3986 @subsection Channel Authentication
3988 @anchor{channel-authentication}
3989 @cindex authentication, of channel code
3990 The @command{guix pull} and @command{guix time-machine} commands
3991 @dfn{authenticate} the code retrieved from channels: they make sure each
3992 commit that is fetched is signed by an authorized developer. The goal
3993 is to protect from unauthorized modifications to the channel that would
3994 lead users to run malicious code.
3996 As a user, you must provide a @dfn{channel introduction} in your
3997 channels file so that Guix knows how to authenticate its first commit.
3998 A channel specification, including its introduction, looks something
4004 (url "https://example.org/my-channel.git")
4006 (make-channel-introduction
4007 "6f0d8cc0d88abb59c324b2990bfee2876016bb86"
4008 (openpgp-fingerprint
4009 "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
4012 The specification above shows the name and URL of the channel. The call
4013 to @code{make-channel-introduction} above specifies that authentication
4014 of this channel starts at commit @code{6f0d8cc@dots{}}, which is signed
4015 by the OpenPGP key with fingerprint @code{CABB A931@dots{}}.
4017 For the main channel, called @code{guix}, you automatically get that
4018 information from your Guix installation. For other channels, include
4019 the channel introduction provided by the channel authors in your
4020 @file{channels.scm} file. Make sure you retrieve the channel
4021 introduction from a trusted source since that is the root of your trust.
4023 If you're curious about the authentication mechanics, read on!
4025 @subsection Using a Custom Guix Channel
4027 The channel called @code{guix} specifies where Guix itself---its command-line
4028 tools as well as its package collection---should be downloaded. For instance,
4029 suppose you want to update from your own copy of the Guix repository at
4030 @code{example.org}, and specifically the @code{super-hacks} branch, you can
4031 write in @code{~/.config/guix/channels.scm} this specification:
4034 ;; Tell 'guix pull' to use my own repo.
4037 (url "https://example.org/my-guix.git")
4038 (branch "super-hacks")))
4042 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
4043 branch of the repository at @code{example.org}.
4045 @subsection Specifying Additional Channels
4047 @cindex extending the package collection (channels)
4048 @cindex personal packages (channels)
4049 @cindex channels, for personal packages
4050 You can also specify @emph{additional channels} to pull from. Let's say you
4051 have a bunch of custom package variants or personal packages that you think
4052 would make little sense to contribute to the Guix project, but would like to
4053 have these packages transparently available to you at the command line. You
4054 would first write modules containing those package definitions (@pxref{Package
4055 Modules}), maintain them in a Git repository, and then you and anyone else can
4056 use it as an additional channel to get packages from. Neat, no?
4058 @c What follows stems from discussions at
4059 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
4060 @c earlier discussions on guix-devel@gnu.org.
4062 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
4063 publish your personal channel to the world, we would like to share a few words
4068 Before publishing a channel, please consider contributing your package
4069 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
4070 to free software of all sorts, and packages in Guix proper are readily
4071 available to all Guix users and benefit from the project's quality assurance
4075 When you maintain package definitions outside Guix, we, Guix developers,
4076 consider that @emph{the compatibility burden is on you}. Remember that
4077 package modules and package definitions are just Scheme code that uses various
4078 programming interfaces (APIs). We want to remain free to change these APIs to
4079 keep improving Guix, possibly in ways that break your channel. We never
4080 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
4084 Corollary: if you're using an external channel and that channel breaks, please
4085 @emph{report the issue to the channel authors}, not to the Guix project.
4088 You've been warned! Having said this, we believe external channels are a
4089 practical way to exert your freedom to augment Guix' package collection and to
4090 share your improvements, which are basic tenets of
4091 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
4092 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
4095 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
4096 @command{guix pull} to pull from it @emph{in addition} to the default Guix
4099 @vindex %default-channels
4101 ;; Add my personal packages to those Guix provides.
4103 (name 'my-personal-packages)
4104 (url "https://example.org/personal-packages.git"))
4109 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
4110 add a channel the list of channels that the variable @code{%default-channels}
4111 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
4112 Manual}). With this file in place, @command{guix pull} builds not only Guix
4113 but also the package modules from your own repository. The result in
4114 @file{~/.config/guix/current} is the union of Guix with your own package
4118 $ guix pull --list-generations
4120 Generation 19 Aug 27 2018 16:20:48
4122 repository URL: https://git.savannah.gnu.org/git/guix.git
4124 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
4125 my-personal-packages dd3df5e
4126 repository URL: https://example.org/personal-packages.git
4128 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
4129 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
4130 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
4134 The output of @command{guix pull} above shows that Generation@tie{}19 includes
4135 both Guix and packages from the @code{my-personal-packages} channel. Among
4136 the new and upgraded packages that are listed, some like @code{my-gimp} and
4137 @code{my-emacs-with-cool-features} might come from
4138 @code{my-personal-packages}, while others come from the Guix default channel.
4140 To create a channel, create a Git repository containing your own package
4141 modules and make it available. The repository can contain anything, but a
4142 useful channel will contain Guile modules that export packages. Once you
4143 start using a channel, Guix will behave as if the root directory of that
4144 channel's Git repository has been added to the Guile load path (@pxref{Load
4145 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
4146 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
4147 module, then the module will be available under the name @code{(my-packages
4148 my-tools)}, and you will be able to use it like any other module
4149 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
4151 @cindex dependencies, channels
4152 @cindex meta-data, channels
4153 @subsection Declaring Channel Dependencies
4155 Channel authors may decide to augment a package collection provided by other
4156 channels. They can declare their channel to be dependent on other channels in
4157 a meta-data file @file{.guix-channel}, which is to be placed in the root of
4158 the channel repository.
4160 The meta-data file should contain a simple S-expression like this:
4167 (name some-collection)
4168 (url "https://example.org/first-collection.git")
4170 ;; The 'introduction' bit below is optional: you would
4171 ;; provide it for dependencies that can be authenticated.
4173 (channel-introduction
4175 (commit "a8883b58dc82e167c96506cf05095f37c2c2c6cd")
4176 (signer "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
4178 (name some-other-collection)
4179 (url "https://example.org/second-collection.git")
4180 (branch "testing"))))
4183 In the above example this channel is declared to depend on two other channels,
4184 which will both be fetched automatically. The modules provided by the channel
4185 will be compiled in an environment where the modules of all these declared
4186 channels are available.
4188 For the sake of reliability and maintainability, you should avoid dependencies
4189 on channels that you don't control, and you should aim to keep the number of
4190 dependencies to a minimum.
4192 @cindex subdirectory, channels
4193 @subsection Package Modules in a Sub-directory
4195 As a channel author, you may want to keep your channel modules in a
4196 sub-directory. If your modules are in the sub-directory @file{guix}, you must
4197 add a meta-data file @file{.guix-channel} that contains:
4205 @cindex channel authorizations
4206 @subsection Specifying Channel Authorizations
4208 @anchor{channel-authorizations}
4209 As we saw above, Guix ensures the source code it pulls from channels
4210 comes from authorized developers. As a channel author, you need to
4211 specify the list of authorized developers in the
4212 @file{.guix-authorizations} file in the channel's Git repository. The
4213 authentication rule is simple: each commit must be signed by a key
4214 listed in the @file{.guix-authorizations} file of its parent
4215 commit(s)@footnote{Git commits form a @dfn{directed acyclic graph}
4216 (DAG). Each commit can have zero or more parents; ``regular'' commits
4217 have one parent and merge commits have two parent commits. Read
4218 @uref{https://eagain.net/articles/git-for-computer-scientists/, @i{Git
4219 for Computer Scientists}} for a great overview.} The
4220 @file{.guix-authorizations} file looks like this:
4223 ;; Example '.guix-authorizations' file.
4226 (version 0) ;current file format version
4228 (("AD17 A21E F8AE D8F1 CC02 DBD9 F8AE D8F1 765C 61E3"
4230 ("2A39 3FFF 68F4 EF7A 3D29 12AF 68F4 EF7A 22FB B2D5"
4232 ("CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"
4236 Each fingerprint is followed by optional key/value pairs, as in the
4237 example above. Currently these key/value pairs are ignored.
4239 This authentication rule creates a chicken-and-egg issue: how do we
4240 authenticate the first commit? Related to that: how do we deal with
4241 channels whose repository history contains unsigned commits and lack
4242 @file{.guix-authorizations}? And how do we fork existing channels?
4244 @cindex channel introduction
4245 Channel introductions answer these questions by describing the first
4246 commit of a channel that should be authenticated. The first time a
4247 channel is fetched with @command{guix pull} or @command{guix
4248 time-machine}, the command looks up the introductory commit and verifies
4249 that it is signed by the specified OpenPGP key. From then on, it
4250 authenticates commits according to the rule above.
4252 Additionally, your channel must provide all the OpenPGP keys that were
4253 ever mentioned in @file{.guix-authorizations}, stored as @file{.key}
4254 files, which can be either binary or ``ASCII-armored''. By default,
4255 those @file{.key} files are searched for in the branch named
4256 @code{keyring} but you can specify a different branch name in
4257 @code{.guix-channel} like so:
4262 (keyring-reference "my-keyring-branch"))
4265 To summarize, as the author of a channel, there are three things you have
4266 to do to allow users to authenticate your code:
4270 Export the OpenPGP keys of past and present committers with @command{gpg
4271 --export} and store them in @file{.key} files, by default in a branch
4272 named @code{keyring} (we recommend making it an @dfn{orphan branch}).
4275 Introduce an initial @file{.guix-authorizations} in the channel's
4276 repository. Do that in a signed commit (@pxref{Commit Access}, for
4277 information on how to sign Git commits.)
4280 Advertise the channel introduction, for instance on your channel's web
4281 page. The channel introduction, as we saw above, is the commit/key
4282 pair---i.e., the commit that introduced @file{.guix-authorizations}, and
4283 the fingerprint of the OpenPGP used to sign it.
4286 Before pushing to your public Git repository, you can run @command{guix
4287 git-authenticate} to verify that you did sign all the commits you are
4288 about to push with an authorized key:
4291 guix git authenticate @var{commit} @var{signer}
4295 where @var{commit} and @var{signer} are your channel introduction.
4296 @xref{Invoking guix git authenticate}, for details.
4298 Publishing a signed channel requires discipline: any mistake, such as an
4299 unsigned commit or a commit signed by an unauthorized key, will prevent
4300 users from pulling from your channel---well, that's the whole point of
4301 authentication! Pay attention to merges in particular: merge commits
4302 are considered authentic if and only if they are signed by a key present
4303 in the @file{.guix-authorizations} file of @emph{both} branches.
4305 @cindex primary URL, channels
4306 @subsection Primary URL
4308 Channel authors can indicate the primary URL of their channel's Git
4309 repository in the @file{.guix-channel} file, like so:
4314 (url "https://example.org/guix.git"))
4317 This allows @command{guix pull} to determine whether it is pulling code
4318 from a mirror of the channel; when that is the case, it warns the user
4319 that the mirror might be stale and displays the primary URL. That way,
4320 users cannot be tricked into fetching code from a stale mirror that does
4321 not receive security updates.
4323 This feature only makes sense for authenticated repositories, such as
4324 the official @code{guix} channel, for which @command{guix pull} ensures
4325 the code it fetches is authentic.
4327 @cindex news, for channels
4328 @subsection Writing Channel News
4330 Channel authors may occasionally want to communicate to their users
4331 information about important changes in the channel. You'd send them all
4332 an email, but that's not convenient.
4334 Instead, channels can provide a @dfn{news file}; when the channel users
4335 run @command{guix pull}, that news file is automatically read and
4336 @command{guix pull --news} can display the announcements that correspond
4337 to the new commits that have been pulled, if any.
4339 To do that, channel authors must first declare the name of the news file
4340 in their @file{.guix-channel} file:
4345 (news-file "etc/news.txt"))
4348 The news file itself, @file{etc/news.txt} in this example, must look
4349 something like this:
4354 (entry (tag "the-bug-fix")
4355 (title (en "Fixed terrible bug")
4357 (body (en "@@emph@{Good news@}! It's fixed!")
4358 (eo "Certe ĝi pli bone funkcias nun!")))
4359 (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
4360 (title (en "Added a great package")
4361 (ca "Què vol dir guix?"))
4362 (body (en "Don't miss the @@code@{hello@} package!"))))
4365 While the news file is using the Scheme syntax, avoid naming it with a
4366 @file{.scm} extension or else it will get picked up when building the
4367 channel and yield an error since it is not a valid module.
4368 Alternatively, you can move the channel module to a subdirectory and
4369 store the news file in another directory.
4371 The file consists of a list of @dfn{news entries}. Each entry is
4372 associated with a commit or tag: it describes changes made in this
4373 commit, possibly in preceding commits as well. Users see entries only
4374 the first time they obtain the commit the entry refers to.
4376 The @code{title} field should be a one-line summary while @code{body}
4377 can be arbitrarily long, and both can contain Texinfo markup
4378 (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
4379 a list of language tag/message tuples, which allows @command{guix pull}
4380 to display news in the language that corresponds to the user's locale.
4382 If you want to translate news using a gettext-based workflow, you can
4383 extract translatable strings with @command{xgettext} (@pxref{xgettext
4384 Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
4385 you write news entries in English first, the command below creates a PO
4386 file containing the strings to translate:
4389 xgettext -o news.po -l scheme -ken etc/news.txt
4392 To sum up, yes, you could use your channel as a blog. But beware, this
4393 is @emph{not quite} what your users might expect.
4395 @subsection Replicating Guix
4397 @cindex pinning, channels
4398 @cindex replicating Guix
4399 @cindex reproducibility, of Guix
4400 The @command{guix pull --list-generations} output above shows precisely which
4401 commits were used to build this instance of Guix. We can thus replicate it,
4402 say, on another machine, by providing a channel specification in
4403 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
4406 ;; Deploy specific commits of my channels of interest.
4409 (url "https://git.savannah.gnu.org/git/guix.git")
4410 (commit "6298c3ffd9654d3231a6f25390b056483e8f407c"))
4412 (name 'my-personal-packages)
4413 (url "https://example.org/personal-packages.git")
4414 (commit "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
4417 The @command{guix describe --format=channels} command can even generate this
4418 list of channels directly (@pxref{Invoking guix describe}). The resulting
4419 file can be used with the -C options of @command{guix pull}
4420 (@pxref{Invoking guix pull}) or @command{guix time-machine}
4421 (@pxref{Invoking guix time-machine}).
4423 At this point the two machines run the @emph{exact same Guix}, with access to
4424 the @emph{exact same packages}. The output of @command{guix build gimp} on
4425 one machine will be exactly the same, bit for bit, as the output of the same
4426 command on the other machine. It also means both machines have access to all
4427 the source code of Guix and, transitively, to all the source code of every
4430 This gives you super powers, allowing you to track the provenance of binary
4431 artifacts with very fine grain, and to reproduce software environments at
4432 will---some sort of ``meta reproducibility'' capabilities, if you will.
4433 @xref{Inferiors}, for another way to take advantage of these super powers.
4435 @node Invoking guix time-machine
4436 @section Invoking @command{guix time-machine}
4438 @cindex @command{guix time-machine}
4439 @cindex pinning, channels
4440 @cindex replicating Guix
4441 @cindex reproducibility, of Guix
4443 The @command{guix time-machine} command provides access to other
4444 revisions of Guix, for example to install older versions of packages,
4445 or to reproduce a computation in an identical environment. The revision
4446 of Guix to be used is defined by a commit or by a channel
4447 description file created by @command{guix describe}
4448 (@pxref{Invoking guix describe}).
4450 The general syntax is:
4453 guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
4456 where @var{command} and @var{arg}@dots{} are passed unmodified to the
4457 @command{guix} command of the specified revision. The @var{options} that define
4458 this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
4461 @item --url=@var{url}
4462 @itemx --commit=@var{commit}
4463 @itemx --branch=@var{branch}
4464 Use the @code{guix} channel from the specified @var{url}, at the
4465 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4466 string), or @var{branch}.
4468 @item --channels=@var{file}
4469 @itemx -C @var{file}
4470 Read the list of channels from @var{file}. @var{file} must contain
4471 Scheme code that evaluates to a list of channel objects.
4472 @xref{Channels} for more information.
4475 As for @command{guix pull}, the absence of any options means that the
4476 the latest commit on the master branch will be used. The command
4479 guix time-machine -- build hello
4482 will thus build the package @code{hello} as defined in the master branch,
4483 which is in general a newer revision of Guix than you have installed.
4484 Time travel works in both directions!
4486 Note that @command{guix time-machine} can trigger builds of channels and
4487 their dependencies, and these are controlled by the standard build
4488 options (@pxref{Common Build Options}).
4493 @c TODO: Remove this once we're more confident about API stability.
4495 The functionality described here is a ``technology preview'' as of version
4496 @value{VERSION}. As such, the interface is subject to change.
4500 @cindex composition of Guix revisions
4501 Sometimes you might need to mix packages from the revision of Guix you're
4502 currently running with packages available in a different revision of Guix.
4503 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
4504 revisions in arbitrary ways.
4506 @cindex inferior packages
4507 Technically, an ``inferior'' is essentially a separate Guix process connected
4508 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4509 @code{(guix inferior)} module allows you to create inferiors and to
4510 communicate with them. It also provides a high-level interface to browse and
4511 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4513 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4514 to interact with a separate revision of Guix. For example, let's assume you
4515 want to install in your profile the current @code{guile} package, along with
4516 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4517 because the newer @code{guile-json} has an incompatible API and you want to
4518 run your code against the old API@. To do that, you could write a manifest for
4519 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4520 manifest, you would create an inferior for that old Guix revision you care
4521 about, and you would look up the @code{guile-json} package in the inferior:
4524 (use-modules (guix inferior) (guix channels)
4525 (srfi srfi-1)) ;for 'first'
4528 ;; This is the old revision from which we want to
4529 ;; extract guile-json.
4532 (url "https://git.savannah.gnu.org/git/guix.git")
4534 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4537 ;; An inferior representing the above revision.
4538 (inferior-for-channels channels))
4540 ;; Now create a manifest with the current "guile" package
4541 ;; and the old "guile-json" package.
4543 (list (first (lookup-inferior-packages inferior "guile-json"))
4544 (specification->package "guile")))
4547 On its first run, @command{guix package --manifest} might have to build the
4548 channel you specified before it can create the inferior; subsequent runs will
4549 be much faster because the Guix revision will be cached.
4551 The @code{(guix inferior)} module provides the following procedures to open an
4554 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4555 [#:cache-directory] [#:ttl]
4556 Return an inferior for @var{channels}, a list of channels. Use the cache at
4557 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4558 This procedure opens a new connection to the build daemon.
4560 As a side effect, this procedure may build or substitute binaries for
4561 @var{channels}, which can take time.
4564 @deffn {Scheme Procedure} open-inferior @var{directory} @
4565 [#:command "bin/guix"]
4566 Open the inferior Guix in @var{directory}, running
4567 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4568 the inferior could not be launched.
4571 @cindex inferior packages
4572 The procedures listed below allow you to obtain and manipulate inferior
4575 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4576 Return the list of packages known to @var{inferior}.
4579 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4581 Return the sorted list of inferior packages matching @var{name} in
4582 @var{inferior}, with highest version numbers first. If @var{version} is true,
4583 return only packages with a version number prefixed by @var{version}.
4586 @deffn {Scheme Procedure} inferior-package? @var{obj}
4587 Return true if @var{obj} is an inferior package.
4590 @deffn {Scheme Procedure} inferior-package-name @var{package}
4591 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4592 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4593 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4594 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4595 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4596 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4597 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4598 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4599 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4600 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4601 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4602 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4603 These procedures are the counterpart of package record accessors
4604 (@pxref{package Reference}). Most of them work by querying the inferior
4605 @var{package} comes from, so the inferior must still be live when you call
4609 Inferior packages can be used transparently like any other package or
4610 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4611 transparently handled by the @code{packages->manifest} procedure, which is
4612 commonly use in manifests (@pxref{Invoking guix package, the
4613 @option{--manifest} option of @command{guix package}}). Thus you can insert
4614 an inferior package pretty much anywhere you would insert a regular package:
4615 in manifests, in the @code{packages} field of your @code{operating-system}
4616 declaration, and so on.
4618 @node Invoking guix describe
4619 @section Invoking @command{guix describe}
4621 @cindex reproducibility
4622 @cindex replicating Guix
4623 Often you may want to answer questions like: ``Which revision of Guix am I
4624 using?'' or ``Which channels am I using?'' This is useful information in many
4625 situations: if you want to @emph{replicate} an environment on a different
4626 machine or user account, if you want to report a bug or to determine what
4627 change in the channels you are using caused it, or if you want to record your
4628 system state for reproducibility purposes. The @command{guix describe}
4629 command answers these questions.
4631 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4632 displays the channel(s) that it was built from, including their repository URL
4633 and commit IDs (@pxref{Channels}):
4637 Generation 10 Sep 03 2018 17:32:44 (current)
4639 repository URL: https://git.savannah.gnu.org/git/guix.git
4641 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4644 If you're familiar with the Git version control system, this is similar in
4645 spirit to @command{git describe}; the output is also similar to that of
4646 @command{guix pull --list-generations}, but limited to the current generation
4647 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4648 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4649 information is all it takes to describe the revision of Guix you're using, and
4650 also to replicate it.
4652 To make it easier to replicate Guix, @command{guix describe} can also be asked
4653 to return a list of channels instead of the human-readable description above:
4656 $ guix describe -f channels
4659 (url "https://git.savannah.gnu.org/git/guix.git")
4661 "e0fa68c7718fffd33d81af415279d6ddb518f727")
4663 (make-channel-introduction
4664 "9edb3f66fd807b096b48283debdcddccfea34bad"
4665 (openpgp-fingerprint
4666 "BBB0 2DDF 2CEA F6A8 0D1D E643 A2A0 6DF2 A33A 54FA")))))
4670 You can save this to a file and feed it to @command{guix pull -C} on some
4671 other machine or at a later point in time, which will instantiate @emph{this
4672 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4673 From there on, since you're able to deploy the same revision of Guix, you can
4674 just as well @emph{replicate a complete software environment}. We humbly
4675 think that this is @emph{awesome}, and we hope you'll like it too!
4677 The details of the options supported by @command{guix describe} are as
4681 @item --format=@var{format}
4682 @itemx -f @var{format}
4683 Produce output in the specified @var{format}, one of:
4687 produce human-readable output;
4689 produce a list of channel specifications that can be passed to @command{guix
4690 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4692 @item channels-sans-intro
4693 like @code{channels}, but omit the @code{introduction} field; use it to
4694 produce a channel specification suitable for Guix version 1.1.0 or
4695 earlier---the @code{introduction} field has to do with channel
4696 authentication (@pxref{Channels, Channel Authentication}) and is not
4697 supported by these older versions;
4700 produce a list of channel specifications in JSON format;
4702 produce a list of channel specifications in Recutils format.
4705 @item --list-formats
4706 Display available formats for @option{--format} option.
4708 @item --profile=@var{profile}
4709 @itemx -p @var{profile}
4710 Display information about @var{profile}.
4713 @node Invoking guix archive
4714 @section Invoking @command{guix archive}
4716 @cindex @command{guix archive}
4718 The @command{guix archive} command allows users to @dfn{export} files
4719 from the store into a single archive, and to later @dfn{import} them on
4720 a machine that runs Guix.
4721 In particular, it allows store files to be transferred from one machine
4722 to the store on another machine.
4725 If you're looking for a way to produce archives in a format suitable for
4726 tools other than Guix, @pxref{Invoking guix pack}.
4729 @cindex exporting store items
4730 To export store files as an archive to standard output, run:
4733 guix archive --export @var{options} @var{specifications}...
4736 @var{specifications} may be either store file names or package
4737 specifications, as for @command{guix package} (@pxref{Invoking guix
4738 package}). For instance, the following command creates an archive
4739 containing the @code{gui} output of the @code{git} package and the main
4740 output of @code{emacs}:
4743 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4746 If the specified packages are not built yet, @command{guix archive}
4747 automatically builds them. The build process may be controlled with the
4748 common build options (@pxref{Common Build Options}).
4750 To transfer the @code{emacs} package to a machine connected over SSH,
4754 guix archive --export -r emacs | ssh the-machine guix archive --import
4758 Similarly, a complete user profile may be transferred from one machine
4759 to another like this:
4762 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4763 ssh the-machine guix archive --import
4767 However, note that, in both examples, all of @code{emacs} and the
4768 profile as well as all of their dependencies are transferred (due to
4769 @option{-r}), regardless of what is already available in the store on
4770 the target machine. The @option{--missing} option can help figure out
4771 which items are missing from the target store. The @command{guix copy}
4772 command simplifies and optimizes this whole process, so this is probably
4773 what you should use in this case (@pxref{Invoking guix copy}).
4775 @cindex nar, archive format
4776 @cindex normalized archive (nar)
4777 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
4778 comparable in spirit to `tar', but with differences
4779 that make it more appropriate for our purposes. First, rather than
4780 recording all Unix metadata for each file, the nar format only mentions
4781 the file type (regular, directory, or symbolic link); Unix permissions
4782 and owner/group are dismissed. Second, the order in which directory
4783 entries are stored always follows the order of file names according to
4784 the C locale collation order. This makes archive production fully
4787 When exporting, the daemon digitally signs the contents of the archive,
4788 and that digital signature is appended. When importing, the daemon
4789 verifies the signature and rejects the import in case of an invalid
4790 signature or if the signing key is not authorized.
4791 @c FIXME: Add xref to daemon doc about signatures.
4793 The main options are:
4797 Export the specified store files or packages (see below). Write the
4798 resulting archive to the standard output.
4800 Dependencies are @emph{not} included in the output, unless
4801 @option{--recursive} is passed.
4805 When combined with @option{--export}, this instructs @command{guix archive}
4806 to include dependencies of the given items in the archive. Thus, the
4807 resulting archive is self-contained: it contains the closure of the
4808 exported store items.
4811 Read an archive from the standard input, and import the files listed
4812 therein into the store. Abort if the archive has an invalid digital
4813 signature, or if it is signed by a public key not among the authorized
4814 keys (see @option{--authorize} below).
4817 Read a list of store file names from the standard input, one per line,
4818 and write on the standard output the subset of these files missing from
4821 @item --generate-key[=@var{parameters}]
4822 @cindex signing, archives
4823 Generate a new key pair for the daemon. This is a prerequisite before
4824 archives can be exported with @option{--export}. Note that this
4825 operation usually takes time, because it needs to gather enough entropy
4826 to generate the key pair.
4828 The generated key pair is typically stored under @file{/etc/guix}, in
4829 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4830 key, which must be kept secret). When @var{parameters} is omitted,
4831 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4832 versions before 1.6.0, it is a 4096-bit RSA key.
4833 Alternatively, @var{parameters} can specify
4834 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4835 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4836 Libgcrypt Reference Manual}).
4839 @cindex authorizing, archives
4840 Authorize imports signed by the public key passed on standard input.
4841 The public key must be in ``s-expression advanced format''---i.e., the
4842 same format as the @file{signing-key.pub} file.
4844 The list of authorized keys is kept in the human-editable file
4845 @file{/etc/guix/acl}. The file contains
4846 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4847 s-expressions''} and is structured as an access-control list in the
4848 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4851 @item --extract=@var{directory}
4852 @itemx -x @var{directory}
4853 Read a single-item archive as served by substitute servers
4854 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4855 low-level operation needed in only very narrow use cases; see below.
4857 For example, the following command extracts the substitute for Emacs
4858 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4862 https://@value{SUBSTITUTE-SERVER}/nar/gzip/@dots{}-emacs-24.5 \
4863 | gunzip | guix archive -x /tmp/emacs
4866 Single-item archives are different from multiple-item archives produced
4867 by @command{guix archive --export}; they contain a single store item,
4868 and they do @emph{not} embed a signature. Thus this operation does
4869 @emph{no} signature verification and its output should be considered
4872 The primary purpose of this operation is to facilitate inspection of
4873 archive contents coming from possibly untrusted substitute servers
4874 (@pxref{Invoking guix challenge}).
4878 Read a single-item archive as served by substitute servers
4879 (@pxref{Substitutes}) and print the list of files it contains, as in
4884 https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-emacs-26.3 \
4885 | lzip -d | guix archive -t
4891 @c *********************************************************************
4893 @chapter Development
4895 @cindex software development
4896 If you are a software developer, Guix provides tools that you should find
4897 helpful---independently of the language you're developing in. This is what
4898 this chapter is about.
4900 The @command{guix environment} command provides a convenient way to set up
4901 @dfn{development environments} containing all the dependencies and tools
4902 necessary to work on the software package of your choice. The @command{guix
4903 pack} command allows you to create @dfn{application bundles} that can be
4904 easily distributed to users who do not run Guix.
4907 * Invoking guix environment:: Setting up development environments.
4908 * Invoking guix pack:: Creating software bundles.
4909 * The GCC toolchain:: Working with languages supported by GCC.
4910 * Invoking guix git authenticate:: Authenticating Git repositories.
4913 @node Invoking guix environment
4914 @section Invoking @command{guix environment}
4916 @cindex reproducible build environments
4917 @cindex development environments
4918 @cindex @command{guix environment}
4919 @cindex environment, package build environment
4920 The purpose of @command{guix environment} is to assist hackers in
4921 creating reproducible development environments without polluting their
4922 package profile. The @command{guix environment} tool takes one or more
4923 packages, builds all of their inputs, and creates a shell
4924 environment to use them.
4926 The general syntax is:
4929 guix environment @var{options} @var{package}@dots{}
4932 The following example spawns a new shell set up for the development of
4936 guix environment guile
4939 If the needed dependencies are not built yet, @command{guix environment}
4940 automatically builds them. The environment of the new shell is an
4941 augmented version of the environment that @command{guix environment} was
4942 run in. It contains the necessary search paths for building the given
4943 package added to the existing environment variables. To create
4944 a ``pure'' environment, in which the original environment variables have
4945 been unset, use the @option{--pure} option@footnote{Users sometimes
4946 wrongfully augment environment variables such as @env{PATH} in their
4947 @file{~/.bashrc} file. As a consequence, when @command{guix
4948 environment} launches it, Bash may read @file{~/.bashrc}, thereby
4949 introducing ``impurities'' in these environment variables. It is an
4950 error to define such environment variables in @file{.bashrc}; instead,
4951 they should be defined in @file{.bash_profile}, which is sourced only by
4952 log-in shells. @xref{Bash Startup Files,,, bash, The GNU Bash Reference
4953 Manual}, for details on Bash start-up files.}.
4955 @vindex GUIX_ENVIRONMENT
4956 @command{guix environment} defines the @env{GUIX_ENVIRONMENT}
4957 variable in the shell it spawns; its value is the file name of the
4958 profile of this environment. This allows users to, say, define a
4959 specific prompt for development environments in their @file{.bashrc}
4960 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
4963 if [ -n "$GUIX_ENVIRONMENT" ]
4965 export PS1="\u@@\h \w [dev]\$ "
4970 ...@: or to browse the profile:
4973 $ ls "$GUIX_ENVIRONMENT/bin"
4976 Additionally, more than one package may be specified, in which case the
4977 union of the inputs for the given packages are used. For example, the
4978 command below spawns a shell where all of the dependencies of both Guile
4979 and Emacs are available:
4982 guix environment guile emacs
4985 Sometimes an interactive shell session is not desired. An arbitrary
4986 command may be invoked by placing the @code{--} token to separate the
4987 command from the rest of the arguments:
4990 guix environment guile -- make -j4
4993 In other situations, it is more convenient to specify the list of
4994 packages needed in the environment. For example, the following command
4995 runs @command{python} from an environment containing Python@tie{}2.7 and
4999 guix environment --ad-hoc python2-numpy python-2.7 -- python
5002 Furthermore, one might want the dependencies of a package and also some
5003 additional packages that are not build-time or runtime dependencies, but
5004 are useful when developing nonetheless. Because of this, the
5005 @option{--ad-hoc} flag is positional. Packages appearing before
5006 @option{--ad-hoc} are interpreted as packages whose dependencies will be
5007 added to the environment. Packages appearing after are interpreted as
5008 packages that will be added to the environment directly. For example,
5009 the following command creates a Guix development environment that
5010 additionally includes Git and strace:
5013 guix environment --pure guix --ad-hoc git strace
5017 Sometimes it is desirable to isolate the environment as much as
5018 possible, for maximal purity and reproducibility. In particular, when
5019 using Guix on a host distro that is not Guix System, it is desirable to
5020 prevent access to @file{/usr/bin} and other system-wide resources from
5021 the development environment. For example, the following command spawns
5022 a Guile REPL in a ``container'' where only the store and the current
5023 working directory are mounted:
5026 guix environment --ad-hoc --container guile -- guile
5030 The @option{--container} option requires Linux-libre 3.19 or newer.
5033 @cindex certificates
5034 Another typical use case for containers is to run security-sensitive
5035 applications such as a web browser. To run Eolie, we must expose and
5036 share some files and directories; we include @code{nss-certs} and expose
5037 @file{/etc/ssl/certs/} for HTTPS authentication; finally we preserve the
5038 the @env{DISPLAY} environment variable since containerized graphical
5039 applications won't display without it.
5042 guix environment --preserve='^DISPLAY$' --container --network \
5043 --expose=/etc/machine-id \
5044 --expose=/etc/ssl/certs/ \
5045 --share=$HOME/.local/share/eolie/=$HOME/.local/share/eolie/ \
5046 --ad-hoc eolie nss-certs dbus -- eolie
5049 The available options are summarized below.
5052 @item --root=@var{file}
5053 @itemx -r @var{file}
5054 @cindex persistent environment
5055 @cindex garbage collector root, for environments
5056 Make @var{file} a symlink to the profile for this environment, and
5057 register it as a garbage collector root.
5059 This is useful if you want to protect your environment from garbage
5060 collection, to make it ``persistent''.
5062 When this option is omitted, the environment is protected from garbage
5063 collection only for the duration of the @command{guix environment}
5064 session. This means that next time you recreate the same environment,
5065 you could have to rebuild or re-download packages. @xref{Invoking guix
5066 gc}, for more on GC roots.
5068 @item --expression=@var{expr}
5069 @itemx -e @var{expr}
5070 Create an environment for the package or list of packages that
5071 @var{expr} evaluates to.
5073 For example, running:
5076 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
5079 starts a shell with the environment for this specific variant of the
5085 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
5088 starts a shell with all the base system packages available.
5090 The above commands only use the default output of the given packages.
5091 To select other outputs, two element tuples can be specified:
5094 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
5097 @item --load=@var{file}
5098 @itemx -l @var{file}
5099 Create an environment for the package or list of packages that the code
5100 within @var{file} evaluates to.
5102 As an example, @var{file} might contain a definition like this
5103 (@pxref{Defining Packages}):
5106 @verbatiminclude environment-gdb.scm
5109 @item --manifest=@var{file}
5110 @itemx -m @var{file}
5111 Create an environment for the packages contained in the manifest object
5112 returned by the Scheme code in @var{file}. This option can be repeated
5113 several times, in which case the manifests are concatenated.
5115 This is similar to the same-named option in @command{guix package}
5116 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
5120 Include all specified packages in the resulting environment, as if an
5121 @i{ad hoc} package were defined with them as inputs. This option is
5122 useful for quickly creating an environment without having to write a
5123 package expression to contain the desired inputs.
5125 For instance, the command:
5128 guix environment --ad-hoc guile guile-sdl -- guile
5131 runs @command{guile} in an environment where Guile and Guile-SDL are
5134 Note that this example implicitly asks for the default output of
5135 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
5136 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
5137 of @code{glib} (@pxref{Packages with Multiple Outputs}).
5139 This option may be composed with the default behavior of @command{guix
5140 environment}. Packages appearing before @option{--ad-hoc} are
5141 interpreted as packages whose dependencies will be added to the
5142 environment, the default behavior. Packages appearing after are
5143 interpreted as packages that will be added to the environment directly.
5146 Unset existing environment variables when building the new environment, except
5147 those specified with @option{--preserve} (see below). This has the effect of
5148 creating an environment in which search paths only contain package inputs.
5150 @item --preserve=@var{regexp}
5151 @itemx -E @var{regexp}
5152 When used alongside @option{--pure}, preserve the environment variables
5153 matching @var{regexp}---in other words, put them on a ``white list'' of
5154 environment variables that must be preserved. This option can be repeated
5158 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
5162 This example runs @command{mpirun} in a context where the only environment
5163 variables defined are @env{PATH}, environment variables whose name starts
5164 with @samp{SLURM}, as well as the usual ``precious'' variables (@env{HOME},
5167 @item --search-paths
5168 Display the environment variable definitions that make up the
5171 @item --system=@var{system}
5172 @itemx -s @var{system}
5173 Attempt to build for @var{system}---e.g., @code{i686-linux}.
5178 Run @var{command} within an isolated container. The current working
5179 directory outside the container is mapped inside the container.
5180 Additionally, unless overridden with @option{--user}, a dummy home
5181 directory is created that matches the current user's home directory, and
5182 @file{/etc/passwd} is configured accordingly.
5184 The spawned process runs as the current user outside the container. Inside
5185 the container, it has the same UID and GID as the current user, unless
5186 @option{--user} is passed (see below).
5190 For containers, share the network namespace with the host system.
5191 Containers created without this flag only have access to the loopback
5194 @item --link-profile
5196 For containers, link the environment profile to @file{~/.guix-profile}
5197 within the container. This is equivalent to running the command
5198 @samp{ln -s $GUIX_ENVIRONMENT ~/.guix-profile} within the container.
5199 Linking will fail and abort the environment if the directory already
5200 exists, which will certainly be the case if @command{guix environment}
5201 was invoked in the user's home directory.
5203 Certain packages are configured to look in @file{~/.guix-profile} for
5204 configuration files and data;@footnote{For example, the
5205 @code{fontconfig} package inspects @file{~/.guix-profile/share/fonts}
5206 for additional fonts.} @option{--link-profile} allows these programs to
5207 behave as expected within the environment.
5209 @item --user=@var{user}
5210 @itemx -u @var{user}
5211 For containers, use the username @var{user} in place of the current
5212 user. The generated @file{/etc/passwd} entry within the container will
5213 contain the name @var{user}, the home directory will be
5214 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
5215 the UID and GID inside the container are 1000. @var{user}
5216 need not exist on the system.
5218 Additionally, any shared or exposed path (see @option{--share} and
5219 @option{--expose} respectively) whose target is within the current user's
5220 home directory will be remapped relative to @file{/home/USER}; this
5221 includes the automatic mapping of the current working directory.
5224 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
5226 guix environment --container --user=foo \
5227 --expose=$HOME/test \
5228 --expose=/tmp/target=$HOME/target
5231 While this will limit the leaking of user identity through home paths
5232 and each of the user fields, this is only one useful component of a
5233 broader privacy/anonymity solution---not one in and of itself.
5236 For containers, the default behavior is to share the current working
5237 directory with the isolated container and immediately change to that
5238 directory within the container. If this is undesirable,
5239 @option{--no-cwd} will cause the current working directory to @emph{not}
5240 be automatically shared and will change to the user's home directory
5241 within the container instead. See also @option{--user}.
5243 @item --expose=@var{source}[=@var{target}]
5244 @itemx --share=@var{source}[=@var{target}]
5245 For containers, @option{--expose} (resp. @option{--share}) exposes the
5246 file system @var{source} from the host system as the read-only
5247 (resp. writable) file system @var{target} within the container. If
5248 @var{target} is not specified, @var{source} is used as the target mount
5249 point in the container.
5251 The example below spawns a Guile REPL in a container in which the user's
5252 home directory is accessible read-only via the @file{/exchange}
5256 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
5261 @command{guix environment}
5262 also supports all of the common build options that @command{guix
5263 build} supports (@pxref{Common Build Options}) as well as package
5264 transformation options (@pxref{Package Transformation Options}).
5266 @node Invoking guix pack
5267 @section Invoking @command{guix pack}
5269 Occasionally you want to pass software to people who are not (yet!)
5270 lucky enough to be using Guix. You'd tell them to run @command{guix
5271 package -i @var{something}}, but that's not possible in this case. This
5272 is where @command{guix pack} comes in.
5275 If you are looking for ways to exchange binaries among machines that
5276 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
5277 publish}, and @ref{Invoking guix archive}.
5282 @cindex application bundle
5283 @cindex software bundle
5284 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
5285 @dfn{software bundle}: it creates a tarball or some other archive
5286 containing the binaries of the software you're interested in, and all
5287 its dependencies. The resulting archive can be used on any machine that
5288 does not have Guix, and people can run the exact same binaries as those
5289 you have with Guix. The pack itself is created in a bit-reproducible
5290 fashion, so anyone can verify that it really contains the build results
5291 that you pretend to be shipping.
5293 For example, to create a bundle containing Guile, Emacs, Geiser, and all
5294 their dependencies, you can run:
5297 $ guix pack guile emacs geiser
5299 /gnu/store/@dots{}-pack.tar.gz
5302 The result here is a tarball containing a @file{/gnu/store} directory
5303 with all the relevant packages. The resulting tarball contains a
5304 @dfn{profile} with the three packages of interest; the profile is the
5305 same as would be created by @command{guix package -i}. It is this
5306 mechanism that is used to create Guix's own standalone binary tarball
5307 (@pxref{Binary Installation}).
5309 Users of this pack would have to run
5310 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
5311 find inconvenient. To work around it, you can create, say, a
5312 @file{/opt/gnu/bin} symlink to the profile:
5315 guix pack -S /opt/gnu/bin=bin guile emacs geiser
5319 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
5321 @cindex relocatable binaries, with @command{guix pack}
5322 What if the recipient of your pack does not have root privileges on
5323 their machine, and thus cannot unpack it in the root file system? In
5324 that case, you will want to use the @option{--relocatable} option (see
5325 below). This option produces @dfn{relocatable binaries}, meaning they
5326 they can be placed anywhere in the file system hierarchy: in the example
5327 above, users can unpack your tarball in their home directory and
5328 directly run @file{./opt/gnu/bin/guile}.
5330 @cindex Docker, build an image with guix pack
5331 Alternatively, you can produce a pack in the Docker image format using
5332 the following command:
5335 guix pack -f docker -S /bin=bin guile guile-readline
5339 The result is a tarball that can be passed to the @command{docker load}
5340 command, followed by @code{docker run}:
5343 docker load < @var{file}
5344 docker run -ti guile-guile-readline /bin/guile
5348 where @var{file} is the image returned by @var{guix pack}, and
5349 @code{guile-guile-readline} is its ``image tag''. See the
5350 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5351 documentation} for more information.
5353 @cindex Singularity, build an image with guix pack
5354 @cindex SquashFS, build an image with guix pack
5355 Yet another option is to produce a SquashFS image with the following
5359 guix pack -f squashfs bash guile emacs geiser
5363 The result is a SquashFS file system image that can either be mounted or
5364 directly be used as a file system container image with the
5365 @uref{https://www.sylabs.io/docs/, Singularity container execution
5366 environment}, using commands like @command{singularity shell} or
5367 @command{singularity exec}.
5369 Several command-line options allow you to customize your pack:
5372 @item --format=@var{format}
5373 @itemx -f @var{format}
5374 Produce a pack in the given @var{format}.
5376 The available formats are:
5380 This is the default format. It produces a tarball containing all the
5381 specified binaries and symlinks.
5384 This produces a tarball that follows the
5385 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
5386 Docker Image Specification}. The ``repository name'' as it appears in
5387 the output of the @command{docker images} command is computed from
5388 package names passed on the command line or in the manifest file.
5391 This produces a SquashFS image containing all the specified binaries and
5392 symlinks, as well as empty mount points for virtual file systems like
5396 Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
5397 For that reason, @command{guix pack -f squashfs} always implies @code{-S
5398 /bin=bin}. Thus, your @command{guix pack} invocation must always start
5399 with something like:
5402 guix pack -f squashfs bash @dots{}
5405 If you forget the @code{bash} (or similar) package, @command{singularity
5406 run} and @command{singularity exec} will fail with an unhelpful ``no
5407 such file or directory'' message.
5411 @cindex relocatable binaries
5414 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
5415 anywhere in the file system hierarchy and run from there.
5417 When this option is passed once, the resulting binaries require support for
5418 @dfn{user namespaces} in the kernel Linux; when passed
5419 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
5420 PRoot support, can be thought of as the abbreviation of ``Really
5421 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to
5422 other techniques if user namespaces are unavailable, and essentially
5423 work anywhere---see below for the implications.
5425 For example, if you create a pack containing Bash with:
5428 guix pack -RR -S /mybin=bin bash
5432 ...@: you can copy that pack to a machine that lacks Guix, and from your
5433 home directory as a normal user, run:
5441 In that shell, if you type @code{ls /gnu/store}, you'll notice that
5442 @file{/gnu/store} shows up and contains all the dependencies of
5443 @code{bash}, even though the machine actually lacks @file{/gnu/store}
5444 altogether! That is probably the simplest way to deploy Guix-built
5445 software on a non-Guix machine.
5448 By default, relocatable binaries rely on the @dfn{user namespace} feature of
5449 the kernel Linux, which allows unprivileged users to mount or change root.
5450 Old versions of Linux did not support it, and some GNU/Linux distributions
5453 To produce relocatable binaries that work even in the absence of user
5454 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
5455 case, binaries will try user namespace support and fall back to another
5456 @dfn{execution engine} if user namespaces are not supported. The
5457 following execution engines are supported:
5461 Try user namespaces and fall back to PRoot if user namespaces are not
5462 supported (see below).
5465 Try user namespaces and fall back to Fakechroot if user namespaces are
5466 not supported (see below).
5469 Run the program through user namespaces and abort if they are not
5473 Run through PRoot. The @uref{https://proot-me.github.io/, PRoot} program
5474 provides the necessary
5475 support for file system virtualization. It achieves that by using the
5476 @code{ptrace} system call on the running program. This approach has the
5477 advantage to work without requiring special kernel support, but it incurs
5478 run-time overhead every time a system call is made.
5481 Run through Fakechroot. @uref{https://github.com/dex4er/fakechroot/,
5482 Fakechroot} virtualizes file system accesses by intercepting calls to C
5483 library functions such as @code{open}, @code{stat}, @code{exec}, and so
5484 on. Unlike PRoot, it incurs very little overhead. However, it does not
5485 always work: for example, some file system accesses made from within the
5486 C library are not intercepted, and file system accesses made @i{via}
5487 direct syscalls are not intercepted either, leading to erratic behavior.
5490 @vindex GUIX_EXECUTION_ENGINE
5491 When running a wrapped program, you can explicitly request one of the
5492 execution engines listed above by setting the
5493 @code{GUIX_EXECUTION_ENGINE} environment variable accordingly.
5496 @cindex entry point, for Docker images
5497 @item --entry-point=@var{command}
5498 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
5499 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
5500 support it. @var{command} must be relative to the profile contained in the
5503 The entry point specifies the command that tools like @code{docker run} or
5504 @code{singularity run} automatically start by default. For example, you can
5508 guix pack -f docker --entry-point=bin/guile guile
5511 The resulting pack can easily be loaded and @code{docker run} with no extra
5512 arguments will spawn @code{bin/guile}:
5515 docker load -i pack.tar.gz
5516 docker run @var{image-id}
5519 @item --expression=@var{expr}
5520 @itemx -e @var{expr}
5521 Consider the package @var{expr} evaluates to.
5523 This has the same purpose as the same-named option in @command{guix
5524 build} (@pxref{Additional Build Options, @option{--expression} in
5525 @command{guix build}}).
5527 @item --manifest=@var{file}
5528 @itemx -m @var{file}
5529 Use the packages contained in the manifest object returned by the Scheme
5530 code in @var{file}. This option can be repeated several times, in which
5531 case the manifests are concatenated.
5533 This has a similar purpose as the same-named option in @command{guix
5534 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
5535 same manifest files. It allows you to define a collection of packages
5536 once and use it both for creating profiles and for creating archives
5537 for use on machines that do not have Guix installed. Note that you can
5538 specify @emph{either} a manifest file @emph{or} a list of packages,
5541 @item --system=@var{system}
5542 @itemx -s @var{system}
5543 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
5544 the system type of the build host.
5546 @item --target=@var{triplet}
5547 @cindex cross-compilation
5548 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
5549 as @code{"aarch64-linux-gnu"} (@pxref{Specifying target triplets, GNU
5550 configuration triplets,, autoconf, Autoconf}).
5552 @item --compression=@var{tool}
5553 @itemx -C @var{tool}
5554 Compress the resulting tarball using @var{tool}---one of @code{gzip},
5555 @code{zstd}, @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no
5558 @item --symlink=@var{spec}
5559 @itemx -S @var{spec}
5560 Add the symlinks specified by @var{spec} to the pack. This option can
5561 appear several times.
5563 @var{spec} has the form @code{@var{source}=@var{target}}, where
5564 @var{source} is the symlink that will be created and @var{target} is the
5567 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
5568 symlink pointing to the @file{bin} sub-directory of the profile.
5570 @item --save-provenance
5571 Save provenance information for the packages passed on the command line.
5572 Provenance information includes the URL and commit of the channels in use
5575 Provenance information is saved in the
5576 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
5577 usual package metadata---the name and version of each package, their
5578 propagated inputs, and so on. It is useful information to the recipient of
5579 the pack, who then knows how the pack was (supposedly) obtained.
5581 This option is not enabled by default because, like timestamps, provenance
5582 information contributes nothing to the build process. In other words, there
5583 is an infinity of channel URLs and commit IDs that can lead to the same pack.
5584 Recording such ``silent'' metadata in the output thus potentially breaks the
5585 source-to-binary bitwise reproducibility property.
5587 @item --root=@var{file}
5588 @itemx -r @var{file}
5589 @cindex garbage collector root, for packs
5590 Make @var{file} a symlink to the resulting pack, and register it as a garbage
5593 @item --localstatedir
5594 @itemx --profile-name=@var{name}
5595 Include the ``local state directory'', @file{/var/guix}, in the resulting
5596 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
5597 profile---by default @var{name} is @code{guix-profile}, which corresponds to
5598 @file{~root/.guix-profile}.
5600 @file{/var/guix} contains the store database (@pxref{The Store}) as well
5601 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
5602 the pack means that the store is ``complete'' and manageable by Guix;
5603 not providing it pack means that the store is ``dead'': items cannot be
5604 added to it or removed from it after extraction of the pack.
5606 One use case for this is the Guix self-contained binary tarball
5607 (@pxref{Binary Installation}).
5611 Print the name of the derivation that builds the pack.
5614 Use the bootstrap binaries to build the pack. This option is only
5615 useful to Guix developers.
5618 In addition, @command{guix pack} supports all the common build options
5619 (@pxref{Common Build Options}) and all the package transformation
5620 options (@pxref{Package Transformation Options}).
5623 @node The GCC toolchain
5624 @section The GCC toolchain
5628 @cindex linker wrapper
5629 @cindex toolchain, for C development
5630 @cindex toolchain, for Fortran development
5632 If you need a complete toolchain for compiling and linking C or C++
5633 source code, use the @code{gcc-toolchain} package. This package
5634 provides a complete GCC toolchain for C/C++ development, including GCC
5635 itself, the GNU C Library (headers and binaries, plus debugging symbols
5636 in the @code{debug} output), Binutils, and a linker wrapper.
5638 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
5639 passed to the linker, add corresponding @code{-rpath} arguments, and
5640 invoke the actual linker with this new set of arguments. You can instruct the
5641 wrapper to refuse to link against libraries not in the store by setting the
5642 @env{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
5644 The package @code{gfortran-toolchain} provides a complete GCC toolchain
5645 for Fortran development. For other languages, please use
5646 @samp{guix search gcc toolchain} (@pxref{guix-search,, Invoking guix package}).
5649 @node Invoking guix git authenticate
5650 @section Invoking @command{guix git authenticate}
5652 The @command{guix git authenticate} command authenticates a Git checkout
5653 following the same rule as for channels (@pxref{channel-authentication,
5654 channel authentication}). That is, starting from a given commit, it
5655 ensures that all subsequent commits are signed by an OpenPGP key whose
5656 fingerprint appears in the @file{.guix-authorizations} file of its
5659 You will find this command useful if you maintain a channel. But in
5660 fact, this authentication mechanism is useful in a broader context, so
5661 you might want to use it for Git repositories that have nothing to do
5664 The general syntax is:
5667 guix git authenticate @var{commit} @var{signer} [@var{options}@dots{}]
5670 By default, this command authenticates the Git checkout in the current
5671 directory; it outputs nothing and exits with exit code zero on success
5672 and non-zero on failure. @var{commit} above denotes the first commit
5673 where authentication takes place, and @var{signer} is the OpenPGP
5674 fingerprint of public key used to sign @var{commit}. Together, they
5675 form a ``channel introduction'' (@pxref{channel-authentication, channel
5676 introduction}). The options below allow you to fine-tune the process.
5679 @item --repository=@var{directory}
5680 @itemx -r @var{directory}
5681 Open the Git repository in @var{directory} instead of the current
5684 @item --keyring=@var{reference}
5685 @itemx -k @var{reference}
5686 Load OpenPGP keyring from @var{reference}, the reference of a branch
5687 such as @code{origin/keyring} or @code{my-keyring}. The branch must
5688 contain OpenPGP public keys in @file{.key} files, either in binary form
5689 or ``ASCII-armored''. By default the keyring is loaded from the branch
5690 named @code{keyring}.
5693 Display commit signing statistics upon completion.
5695 @item --cache-key=@var{key}
5696 Previously-authenticated commits are cached in a file under
5697 @file{~/.cache/guix/authentication}. This option forces the cache to be
5698 stored in file @var{key} in that directory.
5700 @item --historical-authorizations=@var{file}
5701 By default, any commit whose parent commit(s) lack the
5702 @file{.guix-authorizations} file is considered inauthentic. In
5703 contrast, this option considers the authorizations in @var{file} for any
5704 commit that lacks @file{.guix-authorizations}. The format of @var{file}
5705 is the same as that of @file{.guix-authorizations}
5706 (@pxref{channel-authorizations, @file{.guix-authorizations} format}).
5710 @c *********************************************************************
5711 @node Programming Interface
5712 @chapter Programming Interface
5714 GNU Guix provides several Scheme programming interfaces (APIs) to
5715 define, build, and query packages. The first interface allows users to
5716 write high-level package definitions. These definitions refer to
5717 familiar packaging concepts, such as the name and version of a package,
5718 its build system, and its dependencies. These definitions can then be
5719 turned into concrete build actions.
5721 Build actions are performed by the Guix daemon, on behalf of users. In a
5722 standard setup, the daemon has write access to the store---the
5723 @file{/gnu/store} directory---whereas users do not. The recommended
5724 setup also has the daemon perform builds in chroots, under specific
5725 build users, to minimize interference with the rest of the system.
5728 Lower-level APIs are available to interact with the daemon and the
5729 store. To instruct the daemon to perform a build action, users actually
5730 provide it with a @dfn{derivation}. A derivation is a low-level
5731 representation of the build actions to be taken, and the environment in
5732 which they should occur---derivations are to package definitions what
5733 assembly is to C programs. The term ``derivation'' comes from the fact
5734 that build results @emph{derive} from them.
5736 This chapter describes all these APIs in turn, starting from high-level
5737 package definitions.
5740 * Package Modules:: Packages from the programmer's viewpoint.
5741 * Defining Packages:: Defining new packages.
5742 * Build Systems:: Specifying how packages are built.
5743 * The Store:: Manipulating the package store.
5744 * Derivations:: Low-level interface to package derivations.
5745 * The Store Monad:: Purely functional interface to the store.
5746 * G-Expressions:: Manipulating build expressions.
5747 * Invoking guix repl:: Programming Guix in Guile
5750 @node Package Modules
5751 @section Package Modules
5753 From a programming viewpoint, the package definitions of the
5754 GNU distribution are provided by Guile modules in the @code{(gnu packages
5755 @dots{})} name space@footnote{Note that packages under the @code{(gnu
5756 packages @dots{})} module name space are not necessarily ``GNU
5757 packages''. This module naming scheme follows the usual Guile module
5758 naming convention: @code{gnu} means that these modules are distributed
5759 as part of the GNU system, and @code{packages} identifies modules that
5760 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5761 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5762 module exports a variable named @code{emacs}, which is bound to a
5763 @code{<package>} object (@pxref{Defining Packages}).
5765 The @code{(gnu packages @dots{})} module name space is
5766 automatically scanned for packages by the command-line tools. For
5767 instance, when running @code{guix install emacs}, all the @code{(gnu
5768 packages @dots{})} modules are scanned until one that exports a package
5769 object whose name is @code{emacs} is found. This package search
5770 facility is implemented in the @code{(gnu packages)} module.
5772 @cindex customization, of packages
5773 @cindex package module search path
5774 Users can store package definitions in modules with different
5775 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
5776 name and module name must match. For instance, the @code{(my-packages
5777 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
5778 relative to the load path specified with @option{--load-path} or
5779 @env{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
5780 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
5781 these package definitions visible to the user interfaces:
5785 By adding the directory containing your package modules to the search path
5786 with the @code{-L} flag of @command{guix package} and other commands
5787 (@pxref{Common Build Options}), or by setting the @env{GUIX_PACKAGE_PATH}
5788 environment variable described below.
5791 By defining a @dfn{channel} and configuring @command{guix pull} so that it
5792 pulls from it. A channel is essentially a Git repository containing package
5793 modules. @xref{Channels}, for more information on how to define and use
5797 @env{GUIX_PACKAGE_PATH} works similarly to other search path variables:
5799 @defvr {Environment Variable} GUIX_PACKAGE_PATH
5800 This is a colon-separated list of directories to search for additional
5801 package modules. Directories listed in this variable take precedence
5802 over the own modules of the distribution.
5805 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
5806 each package is built based solely on other packages in the
5807 distribution. The root of this dependency graph is a small set of
5808 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
5809 bootstrap)} module. For more information on bootstrapping,
5810 @pxref{Bootstrapping}.
5812 @node Defining Packages
5813 @section Defining Packages
5815 The high-level interface to package definitions is implemented in the
5816 @code{(guix packages)} and @code{(guix build-system)} modules. As an
5817 example, the package definition, or @dfn{recipe}, for the GNU Hello
5818 package looks like this:
5821 (define-module (gnu packages hello)
5822 #:use-module (guix packages)
5823 #:use-module (guix download)
5824 #:use-module (guix build-system gnu)
5825 #:use-module (guix licenses)
5826 #:use-module (gnu packages gawk))
5828 (define-public hello
5834 (uri (string-append "mirror://gnu/hello/hello-" version
5838 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
5839 (build-system gnu-build-system)
5840 (arguments '(#:configure-flags '("--enable-silent-rules")))
5841 (inputs `(("gawk" ,gawk)))
5842 (synopsis "Hello, GNU world: An example GNU package")
5843 (description "Guess what GNU Hello prints!")
5844 (home-page "https://www.gnu.org/software/hello/")
5849 Without being a Scheme expert, the reader may have guessed the meaning
5850 of the various fields here. This expression binds the variable
5851 @code{hello} to a @code{<package>} object, which is essentially a record
5852 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
5853 This package object can be inspected using procedures found in the
5854 @code{(guix packages)} module; for instance, @code{(package-name hello)}
5855 returns---surprise!---@code{"hello"}.
5857 With luck, you may be able to import part or all of the definition of
5858 the package you are interested in from another repository, using the
5859 @code{guix import} command (@pxref{Invoking guix import}).
5861 In the example above, @var{hello} is defined in a module of its own,
5862 @code{(gnu packages hello)}. Technically, this is not strictly
5863 necessary, but it is convenient to do so: all the packages defined in
5864 modules under @code{(gnu packages @dots{})} are automatically known to
5865 the command-line tools (@pxref{Package Modules}).
5867 There are a few points worth noting in the above package definition:
5871 The @code{source} field of the package is an @code{<origin>} object
5872 (@pxref{origin Reference}, for the complete reference).
5873 Here, the @code{url-fetch} method from @code{(guix download)} is used,
5874 meaning that the source is a file to be downloaded over FTP or HTTP.
5876 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
5877 the GNU mirrors defined in @code{(guix download)}.
5879 The @code{sha256} field specifies the expected SHA256 hash of the file
5880 being downloaded. It is mandatory, and allows Guix to check the
5881 integrity of the file. The @code{(base32 @dots{})} form introduces the
5882 base32 representation of the hash. You can obtain this information with
5883 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
5884 hash} (@pxref{Invoking guix hash}).
5887 When needed, the @code{origin} form can also have a @code{patches} field
5888 listing patches to be applied, and a @code{snippet} field giving a
5889 Scheme expression to modify the source code.
5892 @cindex GNU Build System
5893 The @code{build-system} field specifies the procedure to build the
5894 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
5895 represents the familiar GNU Build System, where packages may be
5896 configured, built, and installed with the usual @code{./configure &&
5897 make && make check && make install} command sequence.
5900 The @code{arguments} field specifies options for the build system
5901 (@pxref{Build Systems}). Here it is interpreted by
5902 @var{gnu-build-system} as a request run @file{configure} with the
5903 @option{--enable-silent-rules} flag.
5909 What about these quote (@code{'}) characters? They are Scheme syntax to
5910 introduce a literal list; @code{'} is synonymous with @code{quote}.
5911 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
5912 for details. Here the value of the @code{arguments} field is a list of
5913 arguments passed to the build system down the road, as with @code{apply}
5914 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
5917 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
5918 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
5919 @code{#:configure-flags} is a keyword used to pass a keyword argument
5920 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
5924 The @code{inputs} field specifies inputs to the build process---i.e.,
5925 build-time or run-time dependencies of the package. Here, we define an
5926 input called @code{"gawk"} whose value is that of the @var{gawk}
5927 variable; @var{gawk} is itself bound to a @code{<package>} object.
5929 @cindex backquote (quasiquote)
5932 @cindex comma (unquote)
5936 @findex unquote-splicing
5937 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
5938 us to introduce a literal list in the @code{inputs} field, while
5939 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
5940 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
5943 Note that GCC, Coreutils, Bash, and other essential tools do not need to
5944 be specified as inputs here. Instead, @var{gnu-build-system} takes care
5945 of ensuring that they are present (@pxref{Build Systems}).
5947 However, any other dependencies need to be specified in the
5948 @code{inputs} field. Any dependency not specified here will simply be
5949 unavailable to the build process, possibly leading to a build failure.
5952 @xref{package Reference}, for a full description of possible fields.
5954 Once a package definition is in place, the
5955 package may actually be built using the @code{guix build} command-line
5956 tool (@pxref{Invoking guix build}), troubleshooting any build failures
5957 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
5958 package definition using the @command{guix edit} command
5959 (@pxref{Invoking guix edit}).
5960 @xref{Packaging Guidelines}, for
5961 more information on how to test package definitions, and
5962 @ref{Invoking guix lint}, for information on how to check a definition
5963 for style conformance.
5964 @vindex GUIX_PACKAGE_PATH
5965 Lastly, @pxref{Channels}, for information
5966 on how to extend the distribution by adding your own package definitions
5969 Finally, updating the package definition to a new upstream version
5970 can be partly automated by the @command{guix refresh} command
5971 (@pxref{Invoking guix refresh}).
5973 Behind the scenes, a derivation corresponding to the @code{<package>}
5974 object is first computed by the @code{package-derivation} procedure.
5975 That derivation is stored in a @file{.drv} file under @file{/gnu/store}.
5976 The build actions it prescribes may then be realized by using the
5977 @code{build-derivations} procedure (@pxref{The Store}).
5979 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
5980 Return the @code{<derivation>} object of @var{package} for @var{system}
5981 (@pxref{Derivations}).
5983 @var{package} must be a valid @code{<package>} object, and @var{system}
5984 must be a string denoting the target system type---e.g.,
5985 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
5986 must be a connection to the daemon, which operates on the store
5987 (@pxref{The Store}).
5991 @cindex cross-compilation
5992 Similarly, it is possible to compute a derivation that cross-builds a
5993 package for some other system:
5995 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
5996 @var{package} @var{target} [@var{system}]
5997 Return the @code{<derivation>} object of @var{package} cross-built from
5998 @var{system} to @var{target}.
6000 @var{target} must be a valid GNU triplet denoting the target hardware
6001 and operating system, such as @code{"aarch64-linux-gnu"}
6002 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
6005 @cindex package transformations
6006 @cindex input rewriting
6007 @cindex dependency tree rewriting
6008 Packages can be manipulated in arbitrary ways. An example of a useful
6009 transformation is @dfn{input rewriting}, whereby the dependency tree of
6010 a package is rewritten by replacing specific inputs by others:
6012 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
6013 [@var{rewrite-name}]
6014 Return a procedure that, when passed a package, replaces its direct and
6015 indirect dependencies (but not its implicit inputs) according to
6016 @var{replacements}. @var{replacements} is a list of package pairs; the
6017 first element of each pair is the package to replace, and the second one
6020 Optionally, @var{rewrite-name} is a one-argument procedure that takes
6021 the name of a package and returns its new name after rewrite.
6025 Consider this example:
6028 (define libressl-instead-of-openssl
6029 ;; This is a procedure to replace OPENSSL by LIBRESSL,
6031 (package-input-rewriting `((,openssl . ,libressl))))
6033 (define git-with-libressl
6034 (libressl-instead-of-openssl git))
6038 Here we first define a rewriting procedure that replaces @var{openssl}
6039 with @var{libressl}. Then we use it to define a @dfn{variant} of the
6040 @var{git} package that uses @var{libressl} instead of @var{openssl}.
6041 This is exactly what the @option{--with-input} command-line option does
6042 (@pxref{Package Transformation Options, @option{--with-input}}).
6044 The following variant of @code{package-input-rewriting} can match packages to
6045 be replaced by name rather than by identity.
6047 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
6048 Return a procedure that, given a package, applies the given @var{replacements} to
6049 all the package graph (excluding implicit inputs). @var{replacements} is a list of
6050 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
6051 @code{"guile@@2"}, and each procedure takes a matching package and returns a
6052 replacement for that package.
6055 The example above could be rewritten this way:
6058 (define libressl-instead-of-openssl
6059 ;; Replace all the packages called "openssl" with LibreSSL.
6060 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
6063 The key difference here is that, this time, packages are matched by spec and
6064 not by identity. In other words, any package in the graph that is called
6065 @code{openssl} will be replaced.
6067 A more generic procedure to rewrite a package dependency graph is
6068 @code{package-mapping}: it supports arbitrary changes to nodes in the
6071 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
6072 Return a procedure that, given a package, applies @var{proc} to all the packages
6073 depended on and returns the resulting package. The procedure stops recursion
6074 when @var{cut?} returns true for a given package.
6078 * package Reference:: The package data type.
6079 * origin Reference:: The origin data type.
6083 @node package Reference
6084 @subsection @code{package} Reference
6086 This section summarizes all the options available in @code{package}
6087 declarations (@pxref{Defining Packages}).
6089 @deftp {Data Type} package
6090 This is the data type representing a package recipe.
6094 The name of the package, as a string.
6096 @item @code{version}
6097 The version of the package, as a string.
6100 An object telling how the source code for the package should be
6101 acquired. Most of the time, this is an @code{origin} object, which
6102 denotes a file fetched from the Internet (@pxref{origin Reference}). It
6103 can also be any other ``file-like'' object such as a @code{local-file},
6104 which denotes a file from the local file system (@pxref{G-Expressions,
6105 @code{local-file}}).
6107 @item @code{build-system}
6108 The build system that should be used to build the package (@pxref{Build
6111 @item @code{arguments} (default: @code{'()})
6112 The arguments that should be passed to the build system. This is a
6113 list, typically containing sequential keyword-value pairs.
6115 @item @code{inputs} (default: @code{'()})
6116 @itemx @code{native-inputs} (default: @code{'()})
6117 @itemx @code{propagated-inputs} (default: @code{'()})
6118 @cindex inputs, of packages
6119 These fields list dependencies of the package. Each one is a list of
6120 tuples, where each tuple has a label for the input (a string) as its
6121 first element, a package, origin, or derivation as its second element,
6122 and optionally the name of the output thereof that should be used, which
6123 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
6124 more on package outputs). For example, the list below specifies three
6128 `(("libffi" ,libffi)
6129 ("libunistring" ,libunistring)
6130 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
6133 @cindex cross compilation, package dependencies
6134 The distinction between @code{native-inputs} and @code{inputs} is
6135 necessary when considering cross-compilation. When cross-compiling,
6136 dependencies listed in @code{inputs} are built for the @emph{target}
6137 architecture; conversely, dependencies listed in @code{native-inputs}
6138 are built for the architecture of the @emph{build} machine.
6140 @code{native-inputs} is typically used to list tools needed at
6141 build time, but not at run time, such as Autoconf, Automake, pkg-config,
6142 Gettext, or Bison. @command{guix lint} can report likely mistakes in
6143 this area (@pxref{Invoking guix lint}).
6145 @anchor{package-propagated-inputs}
6146 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
6147 specified packages will be automatically installed alongside the package
6148 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
6149 package}}, for information on how @command{guix package} deals with
6152 For example this is necessary when a C/C++ library needs headers of
6153 another library to compile, or when a pkg-config file refers to another
6154 one @i{via} its @code{Requires} field.
6156 Another example where @code{propagated-inputs} is useful is for languages
6157 that lack a facility to record the run-time search path akin to the
6158 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
6159 more. To ensure that libraries written in those languages can find
6160 library code they depend on at run time, run-time dependencies must be
6161 listed in @code{propagated-inputs} rather than @code{inputs}.
6163 @item @code{outputs} (default: @code{'("out")})
6164 The list of output names of the package. @xref{Packages with Multiple
6165 Outputs}, for typical uses of additional outputs.
6167 @item @code{native-search-paths} (default: @code{'()})
6168 @itemx @code{search-paths} (default: @code{'()})
6169 A list of @code{search-path-specification} objects describing
6170 search-path environment variables honored by the package.
6172 @item @code{replacement} (default: @code{#f})
6173 This must be either @code{#f} or a package object that will be used as a
6174 @dfn{replacement} for this package. @xref{Security Updates, grafts},
6177 @item @code{synopsis}
6178 A one-line description of the package.
6180 @item @code{description}
6181 A more elaborate description of the package.
6183 @item @code{license}
6184 @cindex license, of packages
6185 The license of the package; a value from @code{(guix licenses)},
6186 or a list of such values.
6188 @item @code{home-page}
6189 The URL to the home-page of the package, as a string.
6191 @item @code{supported-systems} (default: @code{%supported-systems})
6192 The list of systems supported by the package, as strings of the form
6193 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
6195 @item @code{location} (default: source location of the @code{package} form)
6196 The source location of the package. It is useful to override this when
6197 inheriting from another package, in which case this field is not
6198 automatically corrected.
6202 @deffn {Scheme Syntax} this-package
6203 When used in the @emph{lexical scope} of a package field definition, this
6204 identifier resolves to the package being defined.
6206 The example below shows how to add a package as a native input of itself when
6214 ;; When cross-compiled, Guile, for example, depends on
6215 ;; a native version of itself. Add it here.
6216 (native-inputs (if (%current-target-system)
6217 `(("self" ,this-package))
6221 It is an error to refer to @code{this-package} outside a package definition.
6224 @node origin Reference
6225 @subsection @code{origin} Reference
6227 This section summarizes all the options available in @code{origin}
6228 declarations (@pxref{Defining Packages}).
6230 @deftp {Data Type} origin
6231 This is the data type representing a source code origin.
6235 An object containing the URI of the source. The object type depends on
6236 the @code{method} (see below). For example, when using the
6237 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
6238 values are: a URL represented as a string, or a list thereof.
6241 A procedure that handles the URI.
6246 @item @var{url-fetch} from @code{(guix download)}
6247 download a file from the HTTP, HTTPS, or FTP URL specified in the
6251 @item @var{git-fetch} from @code{(guix git-download)}
6252 clone the Git version control repository, and check out the revision
6253 specified in the @code{uri} field as a @code{git-reference} object; a
6254 @code{git-reference} looks like this:
6258 (url "https://git.savannah.gnu.org/git/hello.git")
6264 A bytevector containing the SHA-256 hash of the source. This is
6265 equivalent to providing a @code{content-hash} SHA256 object in the
6266 @code{hash} field described below.
6269 The @code{content-hash} object of the source---see below for how to use
6270 @code{content-hash}.
6272 You can obtain this information using @code{guix download}
6273 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
6276 @item @code{file-name} (default: @code{#f})
6277 The file name under which the source code should be saved. When this is
6278 @code{#f}, a sensible default value will be used in most cases. In case
6279 the source is fetched from a URL, the file name from the URL will be
6280 used. For version control checkouts, it is recommended to provide the
6281 file name explicitly because the default is not very descriptive.
6283 @item @code{patches} (default: @code{'()})
6284 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
6285 file-like objects}) pointing to patches to be applied to the source.
6287 This list of patches must be unconditional. In particular, it cannot
6288 depend on the value of @code{%current-system} or
6289 @code{%current-target-system}.
6291 @item @code{snippet} (default: @code{#f})
6292 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
6293 in the source directory. This is a convenient way to modify the source,
6294 sometimes more convenient than a patch.
6296 @item @code{patch-flags} (default: @code{'("-p1")})
6297 A list of command-line flags that should be passed to the @code{patch}
6300 @item @code{patch-inputs} (default: @code{#f})
6301 Input packages or derivations to the patching process. When this is
6302 @code{#f}, the usual set of inputs necessary for patching are provided,
6303 such as GNU@tie{}Patch.
6305 @item @code{modules} (default: @code{'()})
6306 A list of Guile modules that should be loaded during the patching
6307 process and while running the code in the @code{snippet} field.
6309 @item @code{patch-guile} (default: @code{#f})
6310 The Guile package that should be used in the patching process. When
6311 this is @code{#f}, a sensible default is used.
6315 @deftp {Data Type} content-hash @var{value} [@var{algorithm}]
6316 Construct a content hash object for the given @var{algorithm}, and with
6317 @var{value} as its hash value. When @var{algorithm} is omitted, assume
6318 it is @code{sha256}.
6320 @var{value} can be a literal string, in which case it is base32-decoded,
6321 or it can be a bytevector.
6323 The following forms are all equivalent:
6326 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj")
6327 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"
6329 (content-hash (base32
6330 "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"))
6331 (content-hash (base64 "kkb+RPaP7uyMZmu4eXPVkM4BN8yhRd8BTHLslb6f/Rc=")
6335 Technically, @code{content-hash} is currently implemented as a macro.
6336 It performs sanity checks at macro-expansion time, when possible, such
6337 as ensuring that @var{value} has the right size for @var{algorithm}.
6341 @section Build Systems
6343 @cindex build system
6344 Each package definition specifies a @dfn{build system} and arguments for
6345 that build system (@pxref{Defining Packages}). This @code{build-system}
6346 field represents the build procedure of the package, as well as implicit
6347 dependencies of that build procedure.
6349 Build systems are @code{<build-system>} objects. The interface to
6350 create and manipulate them is provided by the @code{(guix build-system)}
6351 module, and actual build systems are exported by specific modules.
6353 @cindex bag (low-level package representation)
6354 Under the hood, build systems first compile package objects to
6355 @dfn{bags}. A @dfn{bag} is like a package, but with less
6356 ornamentation---in other words, a bag is a lower-level representation of
6357 a package, which includes all the inputs of that package, including some
6358 that were implicitly added by the build system. This intermediate
6359 representation is then compiled to a derivation (@pxref{Derivations}).
6361 Build systems accept an optional list of @dfn{arguments}. In package
6362 definitions, these are passed @i{via} the @code{arguments} field
6363 (@pxref{Defining Packages}). They are typically keyword arguments
6364 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
6365 Guile Reference Manual}). The value of these arguments is usually
6366 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
6367 by the daemon (@pxref{Derivations}).
6369 The main build system is @code{gnu-build-system}, which implements the
6370 standard build procedure for GNU and many other packages. It
6371 is provided by the @code{(guix build-system gnu)} module.
6373 @defvr {Scheme Variable} gnu-build-system
6374 @code{gnu-build-system} represents the GNU Build System, and variants
6375 thereof (@pxref{Configuration, configuration and makefile conventions,,
6376 standards, GNU Coding Standards}).
6378 @cindex build phases
6379 In a nutshell, packages using it are configured, built, and installed with
6380 the usual @code{./configure && make && make check && make install}
6381 command sequence. In practice, a few additional steps are often needed.
6382 All these steps are split up in separate @dfn{phases},
6383 notably@footnote{Please see the @code{(guix build gnu-build-system)}
6384 modules for more details about the build phases.}:
6388 Unpack the source tarball, and change the current directory to the
6389 extracted source tree. If the source is actually a directory, copy it
6390 to the build tree, and enter that directory.
6392 @item patch-source-shebangs
6393 Patch shebangs encountered in source files so they refer to the right
6394 store file names. For instance, this changes @code{#!/bin/sh} to
6395 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
6398 Run the @file{configure} script with a number of default options, such
6399 as @option{--prefix=/gnu/store/@dots{}}, as well as the options specified
6400 by the @code{#:configure-flags} argument.
6403 Run @code{make} with the list of flags specified with
6404 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
6405 (the default), build with @code{make -j}.
6408 Run @code{make check}, or some other target specified with
6409 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
6410 @code{#:parallel-tests?} argument is true (the default), run @code{make
6414 Run @code{make install} with the flags listed in @code{#:make-flags}.
6416 @item patch-shebangs
6417 Patch shebangs on the installed executable files.
6420 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
6421 is false), copying them to the @code{debug} output when available
6422 (@pxref{Installing Debugging Files}).
6425 @vindex %standard-phases
6426 The build-side module @code{(guix build gnu-build-system)} defines
6427 @code{%standard-phases} as the default list of build phases.
6428 @code{%standard-phases} is a list of symbol/procedure pairs, where the
6429 procedure implements the actual phase.
6431 The list of phases used for a particular package can be changed with the
6432 @code{#:phases} parameter. For instance, passing:
6435 #:phases (modify-phases %standard-phases (delete 'configure))
6438 means that all the phases described above will be used, except the
6439 @code{configure} phase.
6441 In addition, this build system ensures that the ``standard'' environment
6442 for GNU packages is available. This includes tools such as GCC, libc,
6443 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
6444 build-system gnu)} module for a complete list). We call these the
6445 @dfn{implicit inputs} of a package, because package definitions do not
6446 have to mention them.
6449 Other @code{<build-system>} objects are defined to support other
6450 conventions and tools used by free software packages. They inherit most
6451 of @code{gnu-build-system}, and differ mainly in the set of inputs
6452 implicitly added to the build process, and in the list of phases
6453 executed. Some of these build systems are listed below.
6455 @defvr {Scheme Variable} ant-build-system
6456 This variable is exported by @code{(guix build-system ant)}. It
6457 implements the build procedure for Java packages that can be built with
6458 @url{https://ant.apache.org/, Ant build tool}.
6460 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
6461 provided by the @code{icedtea} package to the set of inputs. Different
6462 packages can be specified with the @code{#:ant} and @code{#:jdk}
6463 parameters, respectively.
6465 When the original package does not provide a suitable Ant build file,
6466 the parameter @code{#:jar-name} can be used to generate a minimal Ant
6467 build file @file{build.xml} with tasks to build the specified jar
6468 archive. In this case the parameter @code{#:source-dir} can be used to
6469 specify the source sub-directory, defaulting to ``src''.
6471 The @code{#:main-class} parameter can be used with the minimal ant
6472 buildfile to specify the main class of the resulting jar. This makes the
6473 jar file executable. The @code{#:test-include} parameter can be used to
6474 specify the list of junit tests to run. It defaults to
6475 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
6476 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
6477 because abstract classes cannot be run as tests.
6479 The parameter @code{#:build-target} can be used to specify the Ant task
6480 that should be run during the @code{build} phase. By default the
6481 ``jar'' task will be run.
6485 @defvr {Scheme Variable} android-ndk-build-system
6486 @cindex Android distribution
6487 @cindex Android NDK build system
6488 This variable is exported by @code{(guix build-system android-ndk)}. It
6489 implements a build procedure for Android NDK (native development kit)
6490 packages using a Guix-specific build process.
6492 The build system assumes that packages install their public interface
6493 (header) files to the subdirectory @file{include} of the @code{out} output and
6494 their libraries to the subdirectory @file{lib} the @code{out} output.
6496 It's also assumed that the union of all the dependencies of a package
6497 has no conflicting files.
6499 For the time being, cross-compilation is not supported - so right now
6500 the libraries and header files are assumed to be host tools.
6504 @defvr {Scheme Variable} asdf-build-system/source
6505 @defvrx {Scheme Variable} asdf-build-system/sbcl
6506 @defvrx {Scheme Variable} asdf-build-system/ecl
6508 These variables, exported by @code{(guix build-system asdf)}, implement
6509 build procedures for Common Lisp packages using
6510 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
6511 definition facility for Common Lisp programs and libraries.
6513 The @code{asdf-build-system/source} system installs the packages in
6514 source form, and can be loaded using any common lisp implementation, via
6515 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
6516 systems in the format which a particular implementation understands.
6517 These build systems can also be used to produce executable programs, or
6518 lisp images which contain a set of packages pre-loaded.
6520 The build system uses naming conventions. For binary packages, the
6521 package name should be prefixed with the lisp implementation, such as
6522 @code{sbcl-} for @code{asdf-build-system/sbcl}.
6524 Additionally, the corresponding source package should be labeled using
6525 the same convention as python packages (see @ref{Python Modules}), using
6526 the @code{cl-} prefix.
6528 For binary packages, each system should be defined as a Guix package.
6529 If one package @code{origin} contains several systems, package variants
6530 can be created in order to build all the systems. Source packages,
6531 which use @code{asdf-build-system/source}, may contain several systems.
6533 In order to create executable programs and images, the build-side
6534 procedures @code{build-program} and @code{build-image} can be used.
6535 They should be called in a build phase after the @code{create-symlinks}
6536 phase, so that the system which was just built can be used within the
6537 resulting image. @code{build-program} requires a list of Common Lisp
6538 expressions to be passed as the @code{#:entry-program} argument.
6540 If the system is not defined within its own @file{.asd} file of the same
6541 name, then the @code{#:asd-file} parameter should be used to specify
6542 which file the system is defined in. Furthermore, if the package
6543 defines a system for its tests in a separate file, it will be loaded
6544 before the tests are run if it is specified by the
6545 @code{#:test-asd-file} parameter. If it is not set, the files
6546 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
6547 and @code{test.asd} will be tried if they exist.
6549 If for some reason the package must be named in a different way than the
6550 naming conventions suggest, the @code{#:asd-system-name} parameter can
6551 be used to specify the name of the system.
6555 @defvr {Scheme Variable} cargo-build-system
6556 @cindex Rust programming language
6557 @cindex Cargo (Rust build system)
6558 This variable is exported by @code{(guix build-system cargo)}. It
6559 supports builds of packages using Cargo, the build tool of the
6560 @uref{https://www.rust-lang.org, Rust programming language}.
6562 It adds @code{rustc} and @code{cargo} to the set of inputs.
6563 A different Rust package can be specified with the @code{#:rust} parameter.
6565 Regular cargo dependencies should be added to the package definition via the
6566 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
6567 spec can be a package or a source definition. Note that the spec must
6568 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
6569 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
6570 should be added to the package definition via the
6571 @code{#:cargo-development-inputs} parameter.
6573 In its @code{configure} phase, this build system will make any source inputs
6574 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
6575 parameters available to cargo. It will also remove an included
6576 @code{Cargo.lock} file to be recreated by @code{cargo} during the
6577 @code{build} phase. The @code{install} phase installs any crate the binaries
6578 if they are defined by the crate.
6582 @defvr {Scheme Variable} copy-build-system
6583 This variable is exported by @code{(guix build-system copy)}. It
6584 supports builds of simple packages that don't require much compiling,
6585 mostly just moving files around.
6587 It adds much of the @code{gnu-build-system} packages to the set of
6588 inputs. Because of this, the @code{copy-build-system} does not require
6589 all the boilerplate code often needed for the
6590 @code{trivial-build-system}.
6592 To further simplify the file installation process, an
6593 @code{#:install-plan} argument is exposed to let the packager specify
6594 which files go where. The install plan is a list of @code{(@var{source}
6595 @var{target} [@var{filters}])}. @var{filters} are optional.
6598 @item When @var{source} matches a file or directory without trailing slash, install it to @var{target}.
6600 @item If @var{target} has a trailing slash, install @var{source} basename beneath @var{target}.
6601 @item Otherwise install @var{source} as @var{target}.
6604 @item When @var{source} is a directory with a trailing slash, or when @var{filters} are used,
6605 the trailing slash of @var{target} is implied with the same meaning
6608 @item Without @var{filters}, install the full @var{source} @emph{content} to @var{target}.
6609 @item With @var{filters} among @code{#:include}, @code{#:include-regexp}, @code{#:exclude},
6610 @code{#:exclude-regexp}, only select files are installed depending on
6611 the filters. Each filters is specified by a list of strings.
6613 @item With @code{#:include}, install all the files which the path suffix matches
6614 at least one of the elements in the given list.
6615 @item With @code{#:include-regexp}, install all the files which the
6616 subpaths match at least one of the regular expressions in the given
6618 @item The @code{#:exclude} and @code{#:exclude-regexp} filters
6619 are the complement of their inclusion counterpart. Without @code{#:include} flags,
6620 install all files but those matching the exclusion filters.
6621 If both inclusions and exclusions are specified, the exclusions are done
6622 on top of the inclusions.
6625 In all cases, the paths relative to @var{source} are preserved within
6632 @item @code{("foo/bar" "share/my-app/")}: Install @file{bar} to @file{share/my-app/bar}.
6633 @item @code{("foo/bar" "share/my-app/baz")}: Install @file{bar} to @file{share/my-app/baz}.
6634 @item @code{("foo/" "share/my-app")}: Install the content of @file{foo} inside @file{share/my-app},
6635 e.g., install @file{foo/sub/file} to @file{share/my-app/sub/file}.
6636 @item @code{("foo/" "share/my-app" #:include ("sub/file"))}: Install only @file{foo/sub/file} to
6637 @file{share/my-app/sub/file}.
6638 @item @code{("foo/sub" "share/my-app" #:include ("file"))}: Install @file{foo/sub/file} to
6639 @file{share/my-app/file}.
6644 @cindex Clojure (programming language)
6645 @cindex simple Clojure build system
6646 @defvr {Scheme Variable} clojure-build-system
6647 This variable is exported by @code{(guix build-system clojure)}. It implements
6648 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
6649 using plain old @code{compile} in Clojure. Cross-compilation is not supported
6652 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
6653 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
6654 @code{#:zip} parameters, respectively.
6656 A list of source directories, test directories and jar names can be specified
6657 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
6658 parameters, respectively. Compile directory and main class can be specified
6659 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
6660 Other parameters are documented below.
6662 This build system is an extension of @code{ant-build-system}, but with the
6663 following phases changed:
6668 This phase calls @code{compile} in Clojure to compile source files and runs
6669 @command{jar} to create jars from both source files and compiled files
6670 according to the include list and exclude list specified in
6671 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
6672 has priority over the include list. These lists consist of symbols
6673 representing Clojure libraries or the special keyword @code{#:all} representing
6674 all Clojure libraries found under the source directories. The parameter
6675 @code{#:omit-source?} decides if source should be included into the jars.
6678 This phase runs tests according to the include list and exclude list specified
6679 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
6680 meanings are analogous to that of @code{#:aot-include} and
6681 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
6682 stands for all Clojure libraries found under the test directories. The
6683 parameter @code{#:tests?} decides if tests should be run.
6686 This phase installs all jars built previously.
6689 Apart from the above, this build system also contains an additional phase:
6694 This phase installs all top-level files with base name matching
6695 @code{%doc-regex}. A different regex can be specified with the
6696 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
6697 directories specified in @code{#:doc-dirs} are installed as well.
6701 @defvr {Scheme Variable} cmake-build-system
6702 This variable is exported by @code{(guix build-system cmake)}. It
6703 implements the build procedure for packages using the
6704 @url{https://www.cmake.org, CMake build tool}.
6706 It automatically adds the @code{cmake} package to the set of inputs.
6707 Which package is used can be specified with the @code{#:cmake}
6710 The @code{#:configure-flags} parameter is taken as a list of flags
6711 passed to the @command{cmake} command. The @code{#:build-type}
6712 parameter specifies in abstract terms the flags passed to the compiler;
6713 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
6714 debugging information''), which roughly means that code is compiled with
6715 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
6718 @defvr {Scheme Variable} dune-build-system
6719 This variable is exported by @code{(guix build-system dune)}. It
6720 supports builds of packages using @uref{https://dune.build/, Dune}, a build
6721 tool for the OCaml programming language. It is implemented as an extension
6722 of the @code{ocaml-build-system} which is described below. As such, the
6723 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
6726 It automatically adds the @code{dune} package to the set of inputs.
6727 Which package is used can be specified with the @code{#:dune}
6730 There is no @code{configure} phase because dune packages typically don't
6731 need to be configured. The @code{#:build-flags} parameter is taken as a
6732 list of flags passed to the @code{dune} command during the build.
6734 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
6735 command instead of the more recent @code{dune} command while building
6736 a package. Its default value is @code{#f}.
6738 The @code{#:package} parameter can be passed to specify a package name, which
6739 is useful when a package contains multiple packages and you want to build
6740 only one of them. This is equivalent to passing the @code{-p} argument to
6744 @defvr {Scheme Variable} go-build-system
6745 This variable is exported by @code{(guix build-system go)}. It
6746 implements a build procedure for Go packages using the standard
6747 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
6748 Go build mechanisms}.
6750 The user is expected to provide a value for the key @code{#:import-path}
6751 and, in some cases, @code{#:unpack-path}. The
6752 @url{https://golang.org/doc/code.html#ImportPaths, import path}
6753 corresponds to the file system path expected by the package's build
6754 scripts and any referring packages, and provides a unique way to
6755 refer to a Go package. It is typically based on a combination of the
6756 package source code's remote URI and file system hierarchy structure. In
6757 some cases, you will need to unpack the package's source code to a
6758 different directory structure than the one indicated by the import path,
6759 and @code{#:unpack-path} should be used in such cases.
6761 Packages that provide Go libraries should install their source code into
6762 the built output. The key @code{#:install-source?}, which defaults to
6763 @code{#t}, controls whether or not the source code is installed. It can
6764 be set to @code{#f} for packages that only provide executable files.
6767 @defvr {Scheme Variable} glib-or-gtk-build-system
6768 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
6769 is intended for use with packages making use of GLib or GTK+.
6771 This build system adds the following two phases to the ones defined by
6772 @code{gnu-build-system}:
6775 @item glib-or-gtk-wrap
6776 The phase @code{glib-or-gtk-wrap} ensures that programs in
6777 @file{bin/} are able to find GLib ``schemas'' and
6778 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
6779 modules}. This is achieved by wrapping the programs in launch scripts
6780 that appropriately set the @env{XDG_DATA_DIRS} and @env{GTK_PATH}
6781 environment variables.
6783 It is possible to exclude specific package outputs from that wrapping
6784 process by listing their names in the
6785 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
6786 when an output is known not to contain any GLib or GTK+ binaries, and
6787 where wrapping would gratuitously add a dependency of that output on
6790 @item glib-or-gtk-compile-schemas
6791 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
6792 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
6793 GSettings schemas} of GLib are compiled. Compilation is performed by the
6794 @command{glib-compile-schemas} program. It is provided by the package
6795 @code{glib:bin} which is automatically imported by the build system.
6796 The @code{glib} package providing @command{glib-compile-schemas} can be
6797 specified with the @code{#:glib} parameter.
6800 Both phases are executed after the @code{install} phase.
6803 @defvr {Scheme Variable} guile-build-system
6804 This build system is for Guile packages that consist exclusively of Scheme
6805 code and that are so lean that they don't even have a makefile, let alone a
6806 @file{configure} script. It compiles Scheme code using @command{guild
6807 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
6808 installs the @file{.scm} and @file{.go} files in the right place. It also
6809 installs documentation.
6811 This build system supports cross-compilation by using the
6812 @option{--target} option of @samp{guild compile}.
6814 Packages built with @code{guile-build-system} must provide a Guile package in
6815 their @code{native-inputs} field.
6818 @defvr {Scheme Variable} julia-build-system
6819 This variable is exported by @code{(guix build-system julia)}. It
6820 implements the build procedure used by @uref{https://julialang.org/,
6821 julia} packages, which essentially is similar to running @samp{julia -e
6822 'using Pkg; Pkg.add(package)'} in an environment where
6823 @env{JULIA_LOAD_PATH} contains the paths to all Julia package inputs.
6824 Tests are run not run.
6826 Julia packages require the source @code{file-name} to be the real name of the
6827 package, correctly capitalized.
6829 For packages requiring shared library dependencies, you may need to write the
6830 @file{/deps/deps.jl} file manually. It's usually a line of @code{const
6831 variable = /gnu/store/library.so} for each dependency, plus a void function
6832 @code{check_deps() = nothing}.
6834 Some older packages that aren't using @file{Package.toml} yet, will require
6835 this file to be created, too. The function @code{julia-create-package-toml}
6836 helps creating the file. You need to pass the outputs and the source of the
6837 package, it's name (the same as the @code{file-name} parameter), the package
6838 uuid, the package version, and a list of dependencies specified by their name
6842 @defvr {Scheme Variable} maven-build-system
6843 This variable is exported by @code{(guix build-system maven)}. It implements
6844 a build procedure for @uref{https://maven.apache.org, Maven} packages. Maven
6845 is a dependency and lifecycle management tool for Java. A user of Maven
6846 specifies dependencies and plugins in a @file{pom.xml} file that Maven reads.
6847 When Maven does not have one of the dependencies or plugins in its repository,
6848 it will download them and use them to build the package.
6850 The maven build system ensures that maven will not try to download any
6851 dependency by running in offline mode. Maven will fail if a dependency is
6852 missing. Before running Maven, the @file{pom.xml} (and subprojects) are
6853 modified to specify the version of dependencies and plugins that match the
6854 versions available in the guix build environment. Dependencies and plugins
6855 must be installed in the fake maven repository at @file{lib/m2}, and are
6856 symlinked into a proper repository before maven is run. Maven is instructed
6857 to use that repository for the build and installs built artifacts there.
6858 Changed files are copied to the @file{lib/m2} directory of the package output.
6860 You can specify a @file{pom.xml} file with the @code{#:pom-file} argument,
6861 or let the build system use the default @file{pom.xml} file in the sources.
6863 In case you need to specify a dependency's version manually, you can use the
6864 @code{#:local-packages} argument. It takes an association list where the key
6865 is the groupId of the package and its value is an association list where the
6866 key is the artifactId of the package and its value is the version you want to
6867 override in the @file{pom.xml}.
6869 Some packages use dependencies or plugins that are not useful at runtime nor
6870 at build time in Guix. You can alter the @file{pom.xml} file to remove them
6871 using the @code{#:exclude} argument. Its value is an association list where
6872 the key is the groupId of the plugin or dependency you want to remove, and
6873 the value is a list of artifactId you want to remove.
6875 You can override the default @code{jdk} and @code{maven} packages with the
6876 corresponding argument, @code{#:jdk} and @code{#:maven}.
6878 The @code{#:maven-plugins} argument is a list of maven plugins used during
6879 the build, with the same format as the @code{inputs} fields of the package
6880 declaration. Its default value is @code{(default-maven-plugins)} which is
6884 @defvr {Scheme Variable} minify-build-system
6885 This variable is exported by @code{(guix build-system minify)}. It
6886 implements a minification procedure for simple JavaScript packages.
6888 It adds @code{uglify-js} to the set of inputs and uses it to compress
6889 all JavaScript files in the @file{src} directory. A different minifier
6890 package can be specified with the @code{#:uglify-js} parameter, but it
6891 is expected that the package writes the minified code to the standard
6894 When the input JavaScript files are not all located in the @file{src}
6895 directory, the parameter @code{#:javascript-files} can be used to
6896 specify a list of file names to feed to the minifier.
6899 @defvr {Scheme Variable} ocaml-build-system
6900 This variable is exported by @code{(guix build-system ocaml)}. It implements
6901 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
6902 of choosing the correct set of commands to run for each package. OCaml
6903 packages can expect many different commands to be run. This build system will
6906 When the package has a @file{setup.ml} file present at the top-level, it will
6907 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
6908 @code{ocaml setup.ml -install}. The build system will assume that this file
6909 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
6910 care of setting the prefix and enabling tests if they are not disabled. You
6911 can pass configure and build flags with the @code{#:configure-flags} and
6912 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
6913 set of flags used to enable tests. The @code{#:use-make?} key can be used to
6914 bypass this system in the build and install phases.
6916 When the package has a @file{configure} file, it is assumed that it is a
6917 hand-made configure script that requires a different argument format than
6918 in the @code{gnu-build-system}. You can add more flags with the
6919 @code{#:configure-flags} key.
6921 When the package has a @file{Makefile} file (or @code{#:use-make?} is
6922 @code{#t}), it will be used and more flags can be passed to the build and
6923 install phases with the @code{#:make-flags} key.
6925 Finally, some packages do not have these files and use a somewhat standard
6926 location for its build system. In that case, the build system will run
6927 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
6928 providing the path to the required findlib module. Additional flags can
6929 be passed via the @code{#:build-flags} key. Install is taken care of by
6930 @command{opam-installer}. In this case, the @code{opam} package must
6931 be added to the @code{native-inputs} field of the package definition.
6933 Note that most OCaml packages assume they will be installed in the same
6934 directory as OCaml, which is not what we want in guix. In particular, they
6935 will install @file{.so} files in their module's directory, which is usually
6936 fine because it is in the OCaml compiler directory. In guix though, these
6937 libraries cannot be found and we use @env{CAML_LD_LIBRARY_PATH}. This
6938 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
6939 @file{.so} libraries should be installed.
6942 @defvr {Scheme Variable} python-build-system
6943 This variable is exported by @code{(guix build-system python)}. It
6944 implements the more or less standard build procedure used by Python
6945 packages, which consists in running @code{python setup.py build} and
6946 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
6948 For packages that install stand-alone Python programs under @code{bin/},
6949 it takes care of wrapping these programs so that their @env{PYTHONPATH}
6950 environment variable points to all the Python libraries they depend on.
6952 Which Python package is used to perform the build can be specified with
6953 the @code{#:python} parameter. This is a useful way to force a package
6954 to be built for a specific version of the Python interpreter, which
6955 might be necessary if the package is only compatible with a single
6956 interpreter version.
6958 By default guix calls @code{setup.py} under control of
6959 @code{setuptools}, much like @command{pip} does. Some packages are not
6960 compatible with setuptools (and pip), thus you can disable this by
6961 setting the @code{#:use-setuptools?} parameter to @code{#f}.
6964 @defvr {Scheme Variable} perl-build-system
6965 This variable is exported by @code{(guix build-system perl)}. It
6966 implements the standard build procedure for Perl packages, which either
6967 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
6968 followed by @code{Build} and @code{Build install}; or in running
6969 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
6970 @code{make} and @code{make install}, depending on which of
6971 @code{Build.PL} or @code{Makefile.PL} is present in the package
6972 distribution. Preference is given to the former if both @code{Build.PL}
6973 and @code{Makefile.PL} exist in the package distribution. This
6974 preference can be reversed by specifying @code{#t} for the
6975 @code{#:make-maker?} parameter.
6977 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
6978 passes flags specified by the @code{#:make-maker-flags} or
6979 @code{#:module-build-flags} parameter, respectively.
6981 Which Perl package is used can be specified with @code{#:perl}.
6984 @defvr {Scheme Variable} qt-build-system
6985 This variable is exported by @code{(guix build-system qt)}. It
6986 is intended for use with applications using Qt or KDE.
6988 This build system adds the following two phases to the ones defined by
6989 @code{cmake-build-system}:
6993 The phase @code{check-setup} prepares the environment for running
6994 the checks as commonly used by Qt test programs.
6995 For now this only sets some environment variables:
6996 @code{QT_QPA_PLATFORM=offscreen},
6997 @code{DBUS_FATAL_WARNINGS=0} and
6998 @code{CTEST_OUTPUT_ON_FAILURE=1}.
7000 This phase is added before the @code{check} phase.
7001 It's a separate phase to ease adjusting if necessary.
7004 The phase @code{qt-wrap}
7005 searches for Qt5 plugin paths, QML paths and some XDG in the inputs
7006 and output. In case some path is found, all programs in the output's
7007 @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
7008 are wrapped in scripts defining the necessary environment variables.
7010 It is possible to exclude specific package outputs from that wrapping process
7011 by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
7012 This is useful when an output is known not to contain any Qt binaries, and
7013 where wrapping would gratuitously add a dependency of that output on Qt, KDE,
7016 This phase is added after the @code{install} phase.
7020 @defvr {Scheme Variable} r-build-system
7021 This variable is exported by @code{(guix build-system r)}. It
7022 implements the build procedure used by @uref{https://r-project.org, R}
7023 packages, which essentially is little more than running @samp{R CMD
7024 INSTALL --library=/gnu/store/@dots{}} in an environment where
7025 @env{R_LIBS_SITE} contains the paths to all R package inputs. Tests are
7026 run after installation using the R function
7027 @code{tools::testInstalledPackage}.
7030 @defvr {Scheme Variable} rakudo-build-system
7031 This variable is exported by @code{(guix build-system rakudo)}. It
7032 implements the build procedure used by @uref{https://rakudo.org/,
7033 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
7034 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
7035 installs the binaries, library files and the resources, as well as wrap
7036 the files under the @code{bin/} directory. Tests can be skipped by
7037 passing @code{#f} to the @code{tests?} parameter.
7039 Which rakudo package is used can be specified with @code{rakudo}.
7040 Which perl6-tap-harness package used for the tests can be specified with
7041 @code{#:prove6} or removed by passing @code{#f} to the
7042 @code{with-prove6?} parameter.
7043 Which perl6-zef package used for tests and installing can be specified
7044 with @code{#:zef} or removed by passing @code{#f} to the
7045 @code{with-zef?} parameter.
7048 @defvr {Scheme Variable} texlive-build-system
7049 This variable is exported by @code{(guix build-system texlive)}. It is
7050 used to build TeX packages in batch mode with a specified engine. The
7051 build system sets the @env{TEXINPUTS} variable to find all TeX source
7052 files in the inputs.
7054 By default it runs @code{luatex} on all files ending on @code{ins}. A
7055 different engine and format can be specified with the
7056 @code{#:tex-format} argument. Different build targets can be specified
7057 with the @code{#:build-targets} argument, which expects a list of file
7058 names. The build system adds only @code{texlive-bin} and
7059 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
7060 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
7061 and @code{#:texlive-latex-base}, respectively.
7063 The @code{#:tex-directory} parameter tells the build system where to
7064 install the built files under the texmf tree.
7067 @defvr {Scheme Variable} ruby-build-system
7068 This variable is exported by @code{(guix build-system ruby)}. It
7069 implements the RubyGems build procedure used by Ruby packages, which
7070 involves running @code{gem build} followed by @code{gem install}.
7072 The @code{source} field of a package that uses this build system
7073 typically references a gem archive, since this is the format that Ruby
7074 developers use when releasing their software. The build system unpacks
7075 the gem archive, potentially patches the source, runs the test suite,
7076 repackages the gem, and installs it. Additionally, directories and
7077 tarballs may be referenced to allow building unreleased gems from Git or
7078 a traditional source release tarball.
7080 Which Ruby package is used can be specified with the @code{#:ruby}
7081 parameter. A list of additional flags to be passed to the @command{gem}
7082 command can be specified with the @code{#:gem-flags} parameter.
7085 @defvr {Scheme Variable} waf-build-system
7086 This variable is exported by @code{(guix build-system waf)}. It
7087 implements a build procedure around the @code{waf} script. The common
7088 phases---@code{configure}, @code{build}, and @code{install}---are
7089 implemented by passing their names as arguments to the @code{waf}
7092 The @code{waf} script is executed by the Python interpreter. Which
7093 Python package is used to run the script can be specified with the
7094 @code{#:python} parameter.
7097 @defvr {Scheme Variable} scons-build-system
7098 This variable is exported by @code{(guix build-system scons)}. It
7099 implements the build procedure used by the SCons software construction
7100 tool. This build system runs @code{scons} to build the package,
7101 @code{scons test} to run tests, and then @code{scons install} to install
7104 Additional flags to be passed to @code{scons} can be specified with the
7105 @code{#:scons-flags} parameter. The default build and install targets
7106 can be overridden with @code{#:build-targets} and
7107 @code{#:install-targets} respectively. The version of Python used to
7108 run SCons can be specified by selecting the appropriate SCons package
7109 with the @code{#:scons} parameter.
7112 @defvr {Scheme Variable} haskell-build-system
7113 This variable is exported by @code{(guix build-system haskell)}. It
7114 implements the Cabal build procedure used by Haskell packages, which
7115 involves running @code{runhaskell Setup.hs configure
7116 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
7117 Instead of installing the package by running @code{runhaskell Setup.hs
7118 install}, to avoid trying to register libraries in the read-only
7119 compiler store directory, the build system uses @code{runhaskell
7120 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
7121 addition, the build system generates the package documentation by
7122 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
7123 is passed. Optional Haddock parameters can be passed with the help of
7124 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
7125 not found, the build system looks for @code{Setup.lhs} instead.
7127 Which Haskell compiler is used can be specified with the @code{#:haskell}
7128 parameter which defaults to @code{ghc}.
7131 @defvr {Scheme Variable} dub-build-system
7132 This variable is exported by @code{(guix build-system dub)}. It
7133 implements the Dub build procedure used by D packages, which
7134 involves running @code{dub build} and @code{dub run}.
7135 Installation is done by copying the files manually.
7137 Which D compiler is used can be specified with the @code{#:ldc}
7138 parameter which defaults to @code{ldc}.
7141 @defvr {Scheme Variable} emacs-build-system
7142 This variable is exported by @code{(guix build-system emacs)}. It
7143 implements an installation procedure similar to the packaging system
7144 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
7146 It first creates the @code{@code{package}-autoloads.el} file, then it
7147 byte compiles all Emacs Lisp files. Differently from the Emacs
7148 packaging system, the Info documentation files are moved to the standard
7149 documentation directory and the @file{dir} file is deleted. The Elisp
7150 package files are installed directly under @file{share/emacs/site-lisp}.
7153 @defvr {Scheme Variable} font-build-system
7154 This variable is exported by @code{(guix build-system font)}. It
7155 implements an installation procedure for font packages where upstream
7156 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
7157 need to be copied into place. It copies font files to standard
7158 locations in the output directory.
7161 @defvr {Scheme Variable} meson-build-system
7162 This variable is exported by @code{(guix build-system meson)}. It
7163 implements the build procedure for packages that use
7164 @url{https://mesonbuild.com, Meson} as their build system.
7166 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
7167 of inputs, and they can be changed with the parameters @code{#:meson}
7168 and @code{#:ninja} if needed. The default Meson is
7169 @code{meson-for-build}, which is special because it doesn't clear the
7170 @code{RUNPATH} of binaries and libraries when they are installed.
7172 This build system is an extension of @code{gnu-build-system}, but with the
7173 following phases changed to some specific for Meson:
7178 The phase runs @code{meson} with the flags specified in
7179 @code{#:configure-flags}. The flag @option{--buildtype} is always set to
7180 @code{debugoptimized} unless something else is specified in
7181 @code{#:build-type}.
7184 The phase runs @code{ninja} to build the package in parallel by default, but
7185 this can be changed with @code{#:parallel-build?}.
7188 The phase runs @code{ninja} with the target specified in @code{#:test-target},
7189 which is @code{"test"} by default.
7192 The phase runs @code{ninja install} and can not be changed.
7195 Apart from that, the build system also adds the following phases:
7200 This phase ensures that all binaries can find the libraries they need.
7201 It searches for required libraries in subdirectories of the package being
7202 built, and adds those to @code{RUNPATH} where needed. It also removes
7203 references to libraries left over from the build phase by
7204 @code{meson-for-build}, such as test dependencies, that aren't actually
7205 required for the program to run.
7207 @item glib-or-gtk-wrap
7208 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
7209 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
7211 @item glib-or-gtk-compile-schemas
7212 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
7213 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
7217 @defvr {Scheme Variable} linux-module-build-system
7218 @code{linux-module-build-system} allows building Linux kernel modules.
7220 @cindex build phases
7221 This build system is an extension of @code{gnu-build-system}, but with the
7222 following phases changed:
7227 This phase configures the environment so that the Linux kernel's Makefile
7228 can be used to build the external kernel module.
7231 This phase uses the Linux kernel's Makefile in order to build the external
7235 This phase uses the Linux kernel's Makefile in order to install the external
7239 It is possible and useful to specify the Linux kernel to use for building
7240 the module (in the @code{arguments} form of a package using the
7241 @code{linux-module-build-system}, use the key @code{#:linux} to specify it).
7244 @defvr {Scheme Variable} node-build-system
7245 This variable is exported by @code{(guix build-system node)}. It
7246 implements the build procedure used by @uref{https://nodejs.org,
7247 Node.js}, which implements an approximation of the @code{npm install}
7248 command, followed by an @code{npm test} command.
7250 Which Node.js package is used to interpret the @code{npm} commands can
7251 be specified with the @code{#:node} parameter which defaults to
7255 Lastly, for packages that do not need anything as sophisticated, a
7256 ``trivial'' build system is provided. It is trivial in the sense that
7257 it provides basically no support: it does not pull any implicit inputs,
7258 and does not have a notion of build phases.
7260 @defvr {Scheme Variable} trivial-build-system
7261 This variable is exported by @code{(guix build-system trivial)}.
7263 This build system requires a @code{#:builder} argument. This argument
7264 must be a Scheme expression that builds the package output(s)---as
7265 with @code{build-expression->derivation} (@pxref{Derivations,
7266 @code{build-expression->derivation}}).
7276 Conceptually, the @dfn{store} is the place where derivations that have
7277 been built successfully are stored---by default, @file{/gnu/store}.
7278 Sub-directories in the store are referred to as @dfn{store items} or
7279 sometimes @dfn{store paths}. The store has an associated database that
7280 contains information such as the store paths referred to by each store
7281 path, and the list of @emph{valid} store items---results of successful
7282 builds. This database resides in @file{@var{localstatedir}/guix/db},
7283 where @var{localstatedir} is the state directory specified @i{via}
7284 @option{--localstatedir} at configure time, usually @file{/var}.
7286 The store is @emph{always} accessed by the daemon on behalf of its clients
7287 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
7288 connect to the daemon over a Unix-domain socket, send requests to it,
7289 and read the result---these are remote procedure calls, or RPCs.
7292 Users must @emph{never} modify files under @file{/gnu/store} directly.
7293 This would lead to inconsistencies and break the immutability
7294 assumptions of Guix's functional model (@pxref{Introduction}).
7296 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
7297 how to check the integrity of the store and attempt recovery from
7298 accidental modifications.
7301 The @code{(guix store)} module provides procedures to connect to the
7302 daemon, and to perform RPCs. These are described below. By default,
7303 @code{open-connection}, and thus all the @command{guix} commands,
7304 connect to the local daemon or to the URI specified by the
7305 @env{GUIX_DAEMON_SOCKET} environment variable.
7307 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
7308 When set, the value of this variable should be a file name or a URI
7309 designating the daemon endpoint. When it is a file name, it denotes a
7310 Unix-domain socket to connect to. In addition to file names, the
7311 supported URI schemes are:
7316 These are for Unix-domain sockets.
7317 @code{file:///var/guix/daemon-socket/socket} is equivalent to
7318 @file{/var/guix/daemon-socket/socket}.
7321 @cindex daemon, remote access
7322 @cindex remote access to the daemon
7323 @cindex daemon, cluster setup
7324 @cindex clusters, daemon setup
7325 These URIs denote connections over TCP/IP, without encryption nor
7326 authentication of the remote host. The URI must specify the host name
7327 and optionally a port number (by default port 44146 is used):
7330 guix://master.guix.example.org:1234
7333 This setup is suitable on local networks, such as clusters, where only
7334 trusted nodes may connect to the build daemon at
7335 @code{master.guix.example.org}.
7337 The @option{--listen} option of @command{guix-daemon} can be used to
7338 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
7339 @option{--listen}}).
7342 @cindex SSH access to build daemons
7343 These URIs allow you to connect to a remote daemon over SSH. This
7344 feature requires Guile-SSH (@pxref{Requirements}) and a working
7345 @command{guile} binary in @env{PATH} on the destination machine. It
7346 supports public key and GSSAPI authentication. A typical URL might look
7350 ssh://charlie@@guix.example.org:22
7353 As for @command{guix copy}, the usual OpenSSH client configuration files
7354 are honored (@pxref{Invoking guix copy}).
7357 Additional URI schemes may be supported in the future.
7359 @c XXX: Remove this note when the protocol incurs fewer round trips
7360 @c and when (guix derivations) no longer relies on file system access.
7362 The ability to connect to remote build daemons is considered
7363 experimental as of @value{VERSION}. Please get in touch with us to
7364 share any problems or suggestions you may have (@pxref{Contributing}).
7368 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
7369 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
7370 @var{reserve-space?} is true, instruct it to reserve a little bit of
7371 extra space on the file system so that the garbage collector can still
7372 operate should the disk become full. Return a server object.
7374 @var{file} defaults to @code{%default-socket-path}, which is the normal
7375 location given the options that were passed to @command{configure}.
7378 @deffn {Scheme Procedure} close-connection @var{server}
7379 Close the connection to @var{server}.
7382 @defvr {Scheme Variable} current-build-output-port
7383 This variable is bound to a SRFI-39 parameter, which refers to the port
7384 where build and error logs sent by the daemon should be written.
7387 Procedures that make RPCs all take a server object as their first
7390 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
7391 @cindex invalid store items
7392 Return @code{#t} when @var{path} designates a valid store item and
7393 @code{#f} otherwise (an invalid item may exist on disk but still be
7394 invalid, for instance because it is the result of an aborted or failed
7397 A @code{&store-protocol-error} condition is raised if @var{path} is not
7398 prefixed by the store directory (@file{/gnu/store}).
7401 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
7402 Add @var{text} under file @var{name} in the store, and return its store
7403 path. @var{references} is the list of store paths referred to by the
7404 resulting store path.
7407 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
7409 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
7410 file names, or derivation/output pairs, using the specified
7411 @var{mode}---@code{(build-mode normal)} by default.
7414 Note that the @code{(guix monads)} module provides a monad as well as
7415 monadic versions of the above procedures, with the goal of making it
7416 more convenient to work with code that accesses the store (@pxref{The
7420 @i{This section is currently incomplete.}
7423 @section Derivations
7426 Low-level build actions and the environment in which they are performed
7427 are represented by @dfn{derivations}. A derivation contains the
7428 following pieces of information:
7432 The outputs of the derivation---derivations produce at least one file or
7433 directory in the store, but may produce more.
7436 @cindex build-time dependencies
7437 @cindex dependencies, build-time
7438 The inputs of the derivations---i.e., its build-time dependencies---which may
7439 be other derivations or plain files in the store (patches, build scripts,
7443 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
7446 The file name of a build script in the store, along with the arguments
7450 A list of environment variables to be defined.
7454 @cindex derivation path
7455 Derivations allow clients of the daemon to communicate build actions to
7456 the store. They exist in two forms: as an in-memory representation,
7457 both on the client- and daemon-side, and as files in the store whose
7458 name end in @file{.drv}---these files are referred to as @dfn{derivation
7459 paths}. Derivations paths can be passed to the @code{build-derivations}
7460 procedure to perform the build actions they prescribe (@pxref{The
7463 @cindex fixed-output derivations
7464 Operations such as file downloads and version-control checkouts for
7465 which the expected content hash is known in advance are modeled as
7466 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
7467 of a fixed-output derivation are independent of its inputs---e.g., a
7468 source code download produces the same result regardless of the download
7469 method and tools being used.
7472 @cindex run-time dependencies
7473 @cindex dependencies, run-time
7474 The outputs of derivations---i.e., the build results---have a set of
7475 @dfn{references}, as reported by the @code{references} RPC or the
7476 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
7477 are the set of run-time dependencies of the build results. References are a
7478 subset of the inputs of the derivation; this subset is automatically computed
7479 by the build daemon by scanning all the files in the outputs.
7481 The @code{(guix derivations)} module provides a representation of
7482 derivations as Scheme objects, along with procedures to create and
7483 otherwise manipulate derivations. The lowest-level primitive to create
7484 a derivation is the @code{derivation} procedure:
7486 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
7487 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
7488 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
7489 [#:system (%current-system)] [#:references-graphs #f] @
7490 [#:allowed-references #f] [#:disallowed-references #f] @
7491 [#:leaked-env-vars #f] [#:local-build? #f] @
7492 [#:substitutable? #t] [#:properties '()]
7493 Build a derivation with the given arguments, and return the resulting
7494 @code{<derivation>} object.
7496 When @var{hash} and @var{hash-algo} are given, a
7497 @dfn{fixed-output derivation} is created---i.e., one whose result is
7498 known in advance, such as a file download. If, in addition,
7499 @var{recursive?} is true, then that fixed output may be an executable
7500 file or a directory and @var{hash} must be the hash of an archive
7501 containing this output.
7503 When @var{references-graphs} is true, it must be a list of file
7504 name/store path pairs. In that case, the reference graph of each store
7505 path is exported in the build environment in the corresponding file, in
7506 a simple text format.
7508 When @var{allowed-references} is true, it must be a list of store items
7509 or outputs that the derivation's output may refer to. Likewise,
7510 @var{disallowed-references}, if true, must be a list of things the
7511 outputs may @emph{not} refer to.
7513 When @var{leaked-env-vars} is true, it must be a list of strings
7514 denoting environment variables that are allowed to ``leak'' from the
7515 daemon's environment to the build environment. This is only applicable
7516 to fixed-output derivations---i.e., when @var{hash} is true. The main
7517 use is to allow variables such as @code{http_proxy} to be passed to
7518 derivations that download files.
7520 When @var{local-build?} is true, declare that the derivation is not a
7521 good candidate for offloading and should rather be built locally
7522 (@pxref{Daemon Offload Setup}). This is the case for small derivations
7523 where the costs of data transfers would outweigh the benefits.
7525 When @var{substitutable?} is false, declare that substitutes of the
7526 derivation's output should not be used (@pxref{Substitutes}). This is
7527 useful, for instance, when building packages that capture details of the
7528 host CPU instruction set.
7530 @var{properties} must be an association list describing ``properties'' of the
7531 derivation. It is kept as-is, uninterpreted, in the derivation.
7535 Here's an example with a shell script as its builder, assuming
7536 @var{store} is an open connection to the daemon, and @var{bash} points
7537 to a Bash executable in the store:
7540 (use-modules (guix utils)
7544 (let ((builder ; add the Bash script to the store
7545 (add-text-to-store store "my-builder.sh"
7546 "echo hello world > $out\n" '())))
7547 (derivation store "foo"
7548 bash `("-e" ,builder)
7549 #:inputs `((,bash) (,builder))
7550 #:env-vars '(("HOME" . "/homeless"))))
7551 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
7554 As can be guessed, this primitive is cumbersome to use directly. A
7555 better approach is to write build scripts in Scheme, of course! The
7556 best course of action for that is to write the build code as a
7557 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
7558 information, @pxref{G-Expressions}.
7560 Once upon a time, @code{gexp->derivation} did not exist and constructing
7561 derivations with build code written in Scheme was achieved with
7562 @code{build-expression->derivation}, documented below. This procedure
7563 is now deprecated in favor of the much nicer @code{gexp->derivation}.
7565 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
7566 @var{name} @var{exp} @
7567 [#:system (%current-system)] [#:inputs '()] @
7568 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
7569 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7570 [#:references-graphs #f] [#:allowed-references #f] @
7571 [#:disallowed-references #f] @
7572 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
7573 Return a derivation that executes Scheme expression @var{exp} as a
7574 builder for derivation @var{name}. @var{inputs} must be a list of
7575 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
7576 @code{"out"} is assumed. @var{modules} is a list of names of Guile
7577 modules from the current search path to be copied in the store,
7578 compiled, and made available in the load path during the execution of
7579 @var{exp}---e.g., @code{((guix build utils) (guix build
7580 gnu-build-system))}.
7582 @var{exp} is evaluated in an environment where @code{%outputs} is bound
7583 to a list of output/path pairs, and where @code{%build-inputs} is bound
7584 to a list of string/output-path pairs made from @var{inputs}.
7585 Optionally, @var{env-vars} is a list of string pairs specifying the name
7586 and value of environment variables visible to the builder. The builder
7587 terminates by passing the result of @var{exp} to @code{exit}; thus, when
7588 @var{exp} returns @code{#f}, the build is considered to have failed.
7590 @var{exp} is built using @var{guile-for-build} (a derivation). When
7591 @var{guile-for-build} is omitted or is @code{#f}, the value of the
7592 @code{%guile-for-build} fluid is used instead.
7594 See the @code{derivation} procedure for the meaning of
7595 @var{references-graphs}, @var{allowed-references},
7596 @var{disallowed-references}, @var{local-build?}, and
7597 @var{substitutable?}.
7601 Here's an example of a single-output derivation that creates a directory
7602 containing one file:
7605 (let ((builder '(let ((out (assoc-ref %outputs "out")))
7606 (mkdir out) ; create /gnu/store/@dots{}-goo
7607 (call-with-output-file (string-append out "/test")
7609 (display '(hello guix) p))))))
7610 (build-expression->derivation store "goo" builder))
7612 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
7616 @node The Store Monad
7617 @section The Store Monad
7621 The procedures that operate on the store described in the previous
7622 sections all take an open connection to the build daemon as their first
7623 argument. Although the underlying model is functional, they either have
7624 side effects or depend on the current state of the store.
7626 The former is inconvenient: the connection to the build daemon has to be
7627 carried around in all those functions, making it impossible to compose
7628 functions that do not take that parameter with functions that do. The
7629 latter can be problematic: since store operations have side effects
7630 and/or depend on external state, they have to be properly sequenced.
7632 @cindex monadic values
7633 @cindex monadic functions
7634 This is where the @code{(guix monads)} module comes in. This module
7635 provides a framework for working with @dfn{monads}, and a particularly
7636 useful monad for our uses, the @dfn{store monad}. Monads are a
7637 construct that allows two things: associating ``context'' with values
7638 (in our case, the context is the store), and building sequences of
7639 computations (here computations include accesses to the store). Values
7640 in a monad---values that carry this additional context---are called
7641 @dfn{monadic values}; procedures that return such values are called
7642 @dfn{monadic procedures}.
7644 Consider this ``normal'' procedure:
7647 (define (sh-symlink store)
7648 ;; Return a derivation that symlinks the 'bash' executable.
7649 (let* ((drv (package-derivation store bash))
7650 (out (derivation->output-path drv))
7651 (sh (string-append out "/bin/bash")))
7652 (build-expression->derivation store "sh"
7653 `(symlink ,sh %output))))
7656 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
7657 as a monadic function:
7660 (define (sh-symlink)
7661 ;; Same, but return a monadic value.
7662 (mlet %store-monad ((drv (package->derivation bash)))
7663 (gexp->derivation "sh"
7664 #~(symlink (string-append #$drv "/bin/bash")
7668 There are several things to note in the second version: the @code{store}
7669 parameter is now implicit and is ``threaded'' in the calls to the
7670 @code{package->derivation} and @code{gexp->derivation} monadic
7671 procedures, and the monadic value returned by @code{package->derivation}
7672 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
7674 As it turns out, the call to @code{package->derivation} can even be
7675 omitted since it will take place implicitly, as we will see later
7676 (@pxref{G-Expressions}):
7679 (define (sh-symlink)
7680 (gexp->derivation "sh"
7681 #~(symlink (string-append #$bash "/bin/bash")
7686 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
7687 @c for the funny quote.
7688 Calling the monadic @code{sh-symlink} has no effect. As someone once
7689 said, ``you exit a monad like you exit a building on fire: by running''.
7690 So, to exit the monad and get the desired effect, one must use
7691 @code{run-with-store}:
7694 (run-with-store (open-connection) (sh-symlink))
7695 @result{} /gnu/store/...-sh-symlink
7698 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
7699 new ``meta-commands'' to make it easier to deal with monadic procedures:
7700 @code{run-in-store}, and @code{enter-store-monad}. The former is used
7701 to ``run'' a single monadic value through the store:
7704 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
7705 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7708 The latter enters a recursive REPL, where all the return values are
7709 automatically run through the store:
7712 scheme@@(guile-user)> ,enter-store-monad
7713 store-monad@@(guile-user) [1]> (package->derivation hello)
7714 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7715 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
7716 $3 = "/gnu/store/@dots{}-foo"
7717 store-monad@@(guile-user) [1]> ,q
7718 scheme@@(guile-user)>
7722 Note that non-monadic values cannot be returned in the
7723 @code{store-monad} REPL.
7725 The main syntactic forms to deal with monads in general are provided by
7726 the @code{(guix monads)} module and are described below.
7728 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
7729 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
7733 @deffn {Scheme Syntax} return @var{val}
7734 Return a monadic value that encapsulates @var{val}.
7737 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
7738 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
7739 procedures @var{mproc}@dots{}@footnote{This operation is commonly
7740 referred to as ``bind'', but that name denotes an unrelated procedure in
7741 Guile. Thus we use this somewhat cryptic symbol inherited from the
7742 Haskell language.}. There can be one @var{mproc} or several of them, as
7747 (with-monad %state-monad
7749 (lambda (x) (return (+ 1 x)))
7750 (lambda (x) (return (* 2 x)))))
7754 @result{} some-state
7758 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
7760 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
7762 Bind the variables @var{var} to the monadic values @var{mval} in
7763 @var{body}, which is a sequence of expressions. As with the bind
7764 operator, this can be thought of as ``unpacking'' the raw, non-monadic
7765 value ``contained'' in @var{mval} and making @var{var} refer to that
7766 raw, non-monadic value within the scope of the @var{body}. The form
7767 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
7768 @var{val}, as per @code{let}. The binding operations occur in sequence
7769 from left to right. The last expression of @var{body} must be a monadic
7770 expression, and its result will become the result of the @code{mlet} or
7771 @code{mlet*} when run in the @var{monad}.
7773 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
7774 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
7777 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
7778 Bind @var{mexp} and the following monadic expressions in sequence,
7779 returning the result of the last expression. Every expression in the
7780 sequence must be a monadic expression.
7782 This is akin to @code{mlet}, except that the return values of the
7783 monadic expressions are ignored. In that sense, it is analogous to
7784 @code{begin}, but applied to monadic expressions.
7787 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
7788 When @var{condition} is true, evaluate the sequence of monadic
7789 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
7790 @var{condition} is false, return @code{*unspecified*} in the current
7791 monad. Every expression in the sequence must be a monadic expression.
7794 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
7795 When @var{condition} is false, evaluate the sequence of monadic
7796 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
7797 @var{condition} is true, return @code{*unspecified*} in the current
7798 monad. Every expression in the sequence must be a monadic expression.
7802 The @code{(guix monads)} module provides the @dfn{state monad}, which
7803 allows an additional value---the state---to be @emph{threaded} through
7804 monadic procedure calls.
7806 @defvr {Scheme Variable} %state-monad
7807 The state monad. Procedures in the state monad can access and change
7808 the state that is threaded.
7810 Consider the example below. The @code{square} procedure returns a value
7811 in the state monad. It returns the square of its argument, but also
7812 increments the current state value:
7816 (mlet %state-monad ((count (current-state)))
7817 (mbegin %state-monad
7818 (set-current-state (+ 1 count))
7821 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
7826 When ``run'' through @code{%state-monad}, we obtain that additional state
7827 value, which is the number of @code{square} calls.
7830 @deffn {Monadic Procedure} current-state
7831 Return the current state as a monadic value.
7834 @deffn {Monadic Procedure} set-current-state @var{value}
7835 Set the current state to @var{value} and return the previous state as a
7839 @deffn {Monadic Procedure} state-push @var{value}
7840 Push @var{value} to the current state, which is assumed to be a list,
7841 and return the previous state as a monadic value.
7844 @deffn {Monadic Procedure} state-pop
7845 Pop a value from the current state and return it as a monadic value.
7846 The state is assumed to be a list.
7849 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
7850 Run monadic value @var{mval} starting with @var{state} as the initial
7851 state. Return two values: the resulting value, and the resulting state.
7854 The main interface to the store monad, provided by the @code{(guix
7855 store)} module, is as follows.
7857 @defvr {Scheme Variable} %store-monad
7858 The store monad---an alias for @code{%state-monad}.
7860 Values in the store monad encapsulate accesses to the store. When its
7861 effect is needed, a value of the store monad must be ``evaluated'' by
7862 passing it to the @code{run-with-store} procedure (see below).
7865 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
7866 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
7867 open store connection.
7870 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
7871 Return as a monadic value the absolute file name in the store of the file
7872 containing @var{text}, a string. @var{references} is a list of store items that the
7873 resulting text file refers to; it defaults to the empty list.
7876 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
7877 Return as a monadic value the absolute file name in the store of the file
7878 containing @var{data}, a bytevector. @var{references} is a list of store
7879 items that the resulting binary file refers to; it defaults to the empty list.
7882 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
7883 [#:recursive? #t] [#:select? (const #t)]
7884 Return the name of @var{file} once interned in the store. Use
7885 @var{name} as its store name, or the basename of @var{file} if
7886 @var{name} is omitted.
7888 When @var{recursive?} is true, the contents of @var{file} are added
7889 recursively; if @var{file} designates a flat file and @var{recursive?}
7890 is true, its contents are added, and its permission bits are kept.
7892 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7893 @var{stat})} for each directory entry, where @var{file} is the entry's
7894 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7895 entries for which @var{select?} does not return true.
7897 The example below adds a file to the store, under two different names:
7900 (run-with-store (open-connection)
7901 (mlet %store-monad ((a (interned-file "README"))
7902 (b (interned-file "README" "LEGU-MIN")))
7903 (return (list a b))))
7905 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
7910 The @code{(guix packages)} module exports the following package-related
7913 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
7914 [#:system (%current-system)] [#:target #f] @
7917 value in the absolute file name of @var{file} within the @var{output}
7918 directory of @var{package}. When @var{file} is omitted, return the name
7919 of the @var{output} directory of @var{package}. When @var{target} is
7920 true, use it as a cross-compilation target triplet.
7922 Note that this procedure does @emph{not} build @var{package}. Thus, the
7923 result might or might not designate an existing file. We recommend not
7924 using this procedure unless you know what you are doing.
7927 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
7928 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
7929 @var{target} [@var{system}]
7930 Monadic version of @code{package-derivation} and
7931 @code{package-cross-derivation} (@pxref{Defining Packages}).
7936 @section G-Expressions
7938 @cindex G-expression
7939 @cindex build code quoting
7940 So we have ``derivations'', which represent a sequence of build actions
7941 to be performed to produce an item in the store (@pxref{Derivations}).
7942 These build actions are performed when asking the daemon to actually
7943 build the derivations; they are run by the daemon in a container
7944 (@pxref{Invoking guix-daemon}).
7946 @cindex strata of code
7947 It should come as no surprise that we like to write these build actions
7948 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
7949 code@footnote{The term @dfn{stratum} in this context was coined by
7950 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
7951 Kiselyov, who has written insightful
7952 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
7953 on this topic}, refers to this kind of code generation as
7954 @dfn{staging}.}: the ``host code''---code that defines packages, talks
7955 to the daemon, etc.---and the ``build code''---code that actually
7956 performs build actions, such as making directories, invoking
7957 @command{make}, etc.
7959 To describe a derivation and its build actions, one typically needs to
7960 embed build code inside host code. It boils down to manipulating build
7961 code as data, and the homoiconicity of Scheme---code has a direct
7962 representation as data---comes in handy for that. But we need more than
7963 the normal @code{quasiquote} mechanism in Scheme to construct build
7966 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
7967 S-expressions adapted to build expressions. G-expressions, or
7968 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
7969 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
7970 @code{#$}, and @code{#$@@}), which are comparable to
7971 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
7972 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
7973 GNU Guile Reference Manual}). However, there are major differences:
7977 Gexps are meant to be written to a file and run or manipulated by other
7981 When a high-level object such as a package or derivation is unquoted
7982 inside a gexp, the result is as if its output file name had been
7986 Gexps carry information about the packages or derivations they refer to,
7987 and these dependencies are automatically added as inputs to the build
7988 processes that use them.
7991 @cindex lowering, of high-level objects in gexps
7992 This mechanism is not limited to package and derivation
7993 objects: @dfn{compilers} able to ``lower'' other high-level objects to
7994 derivations or files in the store can be defined,
7995 such that these objects can also be inserted
7996 into gexps. For example, a useful type of high-level objects that can be
7997 inserted in a gexp is ``file-like objects'', which make it easy to
7998 add files to the store and to refer to them in
7999 derivations and such (see @code{local-file} and @code{plain-file}
8002 To illustrate the idea, here is an example of a gexp:
8009 (symlink (string-append #$coreutils "/bin/ls")
8013 This gexp can be passed to @code{gexp->derivation}; we obtain a
8014 derivation that builds a directory containing exactly one symlink to
8015 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
8018 (gexp->derivation "the-thing" build-exp)
8021 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
8022 substituted to the reference to the @var{coreutils} package in the
8023 actual build code, and @var{coreutils} is automatically made an input to
8024 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
8025 output)}) is replaced by a string containing the directory name of the
8026 output of the derivation.
8028 @cindex cross compilation
8029 In a cross-compilation context, it is useful to distinguish between
8030 references to the @emph{native} build of a package---that can run on the
8031 host---versus references to cross builds of a package. To that end, the
8032 @code{#+} plays the same role as @code{#$}, but is a reference to a
8033 native package build:
8036 (gexp->derivation "vi"
8039 (mkdir (string-append #$output "/bin"))
8040 (system* (string-append #+coreutils "/bin/ln")
8042 (string-append #$emacs "/bin/emacs")
8043 (string-append #$output "/bin/vi")))
8044 #:target "aarch64-linux-gnu")
8048 In the example above, the native build of @var{coreutils} is used, so
8049 that @command{ln} can actually run on the host; but then the
8050 cross-compiled build of @var{emacs} is referenced.
8052 @cindex imported modules, for gexps
8053 @findex with-imported-modules
8054 Another gexp feature is @dfn{imported modules}: sometimes you want to be
8055 able to use certain Guile modules from the ``host environment'' in the
8056 gexp, so those modules should be imported in the ``build environment''.
8057 The @code{with-imported-modules} form allows you to express that:
8060 (let ((build (with-imported-modules '((guix build utils))
8062 (use-modules (guix build utils))
8063 (mkdir-p (string-append #$output "/bin"))))))
8064 (gexp->derivation "empty-dir"
8067 (display "success!\n")
8072 In this example, the @code{(guix build utils)} module is automatically
8073 pulled into the isolated build environment of our gexp, such that
8074 @code{(use-modules (guix build utils))} works as expected.
8076 @cindex module closure
8077 @findex source-module-closure
8078 Usually you want the @emph{closure} of the module to be imported---i.e.,
8079 the module itself and all the modules it depends on---rather than just
8080 the module; failing to do that, attempts to use the module will fail
8081 because of missing dependent modules. The @code{source-module-closure}
8082 procedure computes the closure of a module by looking at its source file
8083 headers, which comes in handy in this case:
8086 (use-modules (guix modules)) ;for 'source-module-closure'
8088 (with-imported-modules (source-module-closure
8089 '((guix build utils)
8091 (gexp->derivation "something-with-vms"
8093 (use-modules (guix build utils)
8098 @cindex extensions, for gexps
8099 @findex with-extensions
8100 In the same vein, sometimes you want to import not just pure-Scheme
8101 modules, but also ``extensions'' such as Guile bindings to C libraries
8102 or other ``full-blown'' packages. Say you need the @code{guile-json}
8103 package available on the build side, here's how you would do it:
8106 (use-modules (gnu packages guile)) ;for 'guile-json'
8108 (with-extensions (list guile-json)
8109 (gexp->derivation "something-with-json"
8111 (use-modules (json))
8115 The syntactic form to construct gexps is summarized below.
8117 @deffn {Scheme Syntax} #~@var{exp}
8118 @deffnx {Scheme Syntax} (gexp @var{exp})
8119 Return a G-expression containing @var{exp}. @var{exp} may contain one
8120 or more of the following forms:
8124 @itemx (ungexp @var{obj})
8125 Introduce a reference to @var{obj}. @var{obj} may have one of the
8126 supported types, for example a package or a
8127 derivation, in which case the @code{ungexp} form is replaced by its
8128 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
8130 If @var{obj} is a list, it is traversed and references to supported
8131 objects are substituted similarly.
8133 If @var{obj} is another gexp, its contents are inserted and its
8134 dependencies are added to those of the containing gexp.
8136 If @var{obj} is another kind of object, it is inserted as is.
8138 @item #$@var{obj}:@var{output}
8139 @itemx (ungexp @var{obj} @var{output})
8140 This is like the form above, but referring explicitly to the
8141 @var{output} of @var{obj}---this is useful when @var{obj} produces
8142 multiple outputs (@pxref{Packages with Multiple Outputs}).
8145 @itemx #+@var{obj}:output
8146 @itemx (ungexp-native @var{obj})
8147 @itemx (ungexp-native @var{obj} @var{output})
8148 Same as @code{ungexp}, but produces a reference to the @emph{native}
8149 build of @var{obj} when used in a cross compilation context.
8151 @item #$output[:@var{output}]
8152 @itemx (ungexp output [@var{output}])
8153 Insert a reference to derivation output @var{output}, or to the main
8154 output when @var{output} is omitted.
8156 This only makes sense for gexps passed to @code{gexp->derivation}.
8159 @itemx (ungexp-splicing @var{lst})
8160 Like the above, but splices the contents of @var{lst} inside the
8164 @itemx (ungexp-native-splicing @var{lst})
8165 Like the above, but refers to native builds of the objects listed in
8170 G-expressions created by @code{gexp} or @code{#~} are run-time objects
8171 of the @code{gexp?} type (see below).
8174 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
8175 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
8176 in their execution environment.
8178 Each item in @var{modules} can be the name of a module, such as
8179 @code{(guix build utils)}, or it can be a module name, followed by an
8180 arrow, followed by a file-like object:
8183 `((guix build utils)
8185 ((guix config) => ,(scheme-file "config.scm"
8186 #~(define-module @dots{}))))
8190 In the example above, the first two modules are taken from the search
8191 path, and the last one is created from the given file-like object.
8193 This form has @emph{lexical} scope: it has an effect on the gexps
8194 directly defined in @var{body}@dots{}, but not on those defined, say, in
8195 procedures called from @var{body}@dots{}.
8198 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
8199 Mark the gexps defined in @var{body}@dots{} as requiring
8200 @var{extensions} in their build and execution environment.
8201 @var{extensions} is typically a list of package objects such as those
8202 defined in the @code{(gnu packages guile)} module.
8204 Concretely, the packages listed in @var{extensions} are added to the
8205 load path while compiling imported modules in @var{body}@dots{}; they
8206 are also added to the load path of the gexp returned by
8210 @deffn {Scheme Procedure} gexp? @var{obj}
8211 Return @code{#t} if @var{obj} is a G-expression.
8214 G-expressions are meant to be written to disk, either as code building
8215 some derivation, or as plain files in the store. The monadic procedures
8216 below allow you to do that (@pxref{The Store Monad}, for more
8217 information about monads).
8219 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
8220 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
8221 [#:hash #f] [#:hash-algo #f] @
8222 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
8223 [#:module-path @code{%load-path}] @
8224 [#:effective-version "2.2"] @
8225 [#:references-graphs #f] [#:allowed-references #f] @
8226 [#:disallowed-references #f] @
8227 [#:leaked-env-vars #f] @
8228 [#:script-name (string-append @var{name} "-builder")] @
8229 [#:deprecation-warnings #f] @
8230 [#:local-build? #f] [#:substitutable? #t] @
8231 [#:properties '()] [#:guile-for-build #f]
8232 Return a derivation @var{name} that runs @var{exp} (a gexp) with
8233 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
8234 stored in a file called @var{script-name}. When @var{target} is true,
8235 it is used as the cross-compilation target triplet for packages referred
8238 @var{modules} is deprecated in favor of @code{with-imported-modules}.
8240 make @var{modules} available in the evaluation context of @var{exp};
8241 @var{modules} is a list of names of Guile modules searched in
8242 @var{module-path} to be copied in the store, compiled, and made available in
8243 the load path during the execution of @var{exp}---e.g., @code{((guix
8244 build utils) (guix build gnu-build-system))}.
8246 @var{effective-version} determines the string to use when adding extensions of
8247 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
8249 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
8252 When @var{references-graphs} is true, it must be a list of tuples of one of the
8256 (@var{file-name} @var{package})
8257 (@var{file-name} @var{package} @var{output})
8258 (@var{file-name} @var{derivation})
8259 (@var{file-name} @var{derivation} @var{output})
8260 (@var{file-name} @var{store-item})
8263 The right-hand-side of each element of @var{references-graphs} is automatically made
8264 an input of the build process of @var{exp}. In the build environment, each
8265 @var{file-name} contains the reference graph of the corresponding item, in a simple
8268 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
8269 In the latter case, the list denotes store items that the result is allowed to
8270 refer to. Any reference to another store item will lead to a build error.
8271 Similarly for @var{disallowed-references}, which can list items that must not be
8272 referenced by the outputs.
8274 @var{deprecation-warnings} determines whether to show deprecation warnings while
8275 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
8277 The other arguments are as for @code{derivation} (@pxref{Derivations}).
8280 @cindex file-like objects
8281 The @code{local-file}, @code{plain-file}, @code{computed-file},
8282 @code{program-file}, and @code{scheme-file} procedures below return
8283 @dfn{file-like objects}. That is, when unquoted in a G-expression,
8284 these objects lead to a file in the store. Consider this G-expression:
8287 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
8288 #$(local-file "/tmp/my-nscd.conf"))
8291 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
8292 to the store. Once expanded, for instance @i{via}
8293 @code{gexp->derivation}, the G-expression refers to that copy under
8294 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
8295 does not have any effect on what the G-expression does.
8296 @code{plain-file} can be used similarly; it differs in that the file
8297 content is directly passed as a string.
8299 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
8300 [#:recursive? #f] [#:select? (const #t)]
8301 Return an object representing local file @var{file} to add to the store;
8302 this object can be used in a gexp. If @var{file} is a literal string
8303 denoting a relative file name, it is looked up relative to the source
8304 file where it appears; if @var{file} is not a literal string, it is
8305 looked up relative to the current working directory at run time.
8306 @var{file} will be added to the store under @var{name}--by default the
8307 base name of @var{file}.
8309 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
8310 designates a flat file and @var{recursive?} is true, its contents are added, and its
8311 permission bits are kept.
8313 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
8314 @var{stat})} for each directory entry, where @var{file} is the entry's
8315 absolute file name and @var{stat} is the result of @code{lstat}; exclude
8316 entries for which @var{select?} does not return true.
8318 This is the declarative counterpart of the @code{interned-file} monadic
8319 procedure (@pxref{The Store Monad, @code{interned-file}}).
8322 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
8323 Return an object representing a text file called @var{name} with the given
8324 @var{content} (a string or a bytevector) to be added to the store.
8326 This is the declarative counterpart of @code{text-file}.
8329 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
8330 [#:options '(#:local-build? #t)]
8331 Return an object representing the store item @var{name}, a file or
8332 directory computed by @var{gexp}. @var{options}
8333 is a list of additional arguments to pass to @code{gexp->derivation}.
8335 This is the declarative counterpart of @code{gexp->derivation}.
8338 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
8339 [#:guile (default-guile)] [#:module-path %load-path] @
8340 [#:system (%current-system)] [#:target #f]
8341 Return an executable script @var{name} that runs @var{exp} using
8342 @var{guile}, with @var{exp}'s imported modules in its search path.
8343 Look up @var{exp}'s modules in @var{module-path}.
8345 The example below builds a script that simply invokes the @command{ls}
8349 (use-modules (guix gexp) (gnu packages base))
8351 (gexp->script "list-files"
8352 #~(execl #$(file-append coreutils "/bin/ls")
8356 When ``running'' it through the store (@pxref{The Store Monad,
8357 @code{run-with-store}}), we obtain a derivation that produces an
8358 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
8361 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
8363 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
8367 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
8368 [#:guile #f] [#:module-path %load-path]
8369 Return an object representing the executable store item @var{name} that
8370 runs @var{gexp}. @var{guile} is the Guile package used to execute that
8371 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
8373 This is the declarative counterpart of @code{gexp->script}.
8376 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
8377 [#:set-load-path? #t] [#:module-path %load-path] @
8379 [#:guile (default-guile)]
8380 Return a derivation that builds a file @var{name} containing @var{exp}.
8381 When @var{splice?} is true, @var{exp} is considered to be a list of
8382 expressions that will be spliced in the resulting file.
8384 When @var{set-load-path?} is true, emit code in the resulting file to
8385 set @code{%load-path} and @code{%load-compiled-path} to honor
8386 @var{exp}'s imported modules. Look up @var{exp}'s modules in
8389 The resulting file holds references to all the dependencies of @var{exp}
8390 or a subset thereof.
8393 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} @
8394 [#:splice? #f] [#:set-load-path? #t]
8395 Return an object representing the Scheme file @var{name} that contains
8398 This is the declarative counterpart of @code{gexp->file}.
8401 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
8402 Return as a monadic value a derivation that builds a text file
8403 containing all of @var{text}. @var{text} may list, in addition to
8404 strings, objects of any type that can be used in a gexp: packages,
8405 derivations, local file objects, etc. The resulting store file holds
8406 references to all these.
8408 This variant should be preferred over @code{text-file} anytime the file
8409 to create will reference items from the store. This is typically the
8410 case when building a configuration file that embeds store file names,
8414 (define (profile.sh)
8415 ;; Return the name of a shell script in the store that
8416 ;; initializes the 'PATH' environment variable.
8417 (text-file* "profile.sh"
8418 "export PATH=" coreutils "/bin:"
8419 grep "/bin:" sed "/bin\n"))
8422 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
8423 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
8424 preventing them from being garbage-collected during its lifetime.
8427 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
8428 Return an object representing store file @var{name} containing
8429 @var{text}. @var{text} is a sequence of strings and file-like objects,
8433 (mixed-text-file "profile"
8434 "export PATH=" coreutils "/bin:" grep "/bin")
8437 This is the declarative counterpart of @code{text-file*}.
8440 @deffn {Scheme Procedure} file-union @var{name} @var{files}
8441 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
8442 Each item in @var{files} must be a two-element list where the first element is the
8443 file name to use in the new directory, and the second element is a gexp
8444 denoting the target file. Here's an example:
8448 `(("hosts" ,(plain-file "hosts"
8449 "127.0.0.1 localhost"))
8450 ("bashrc" ,(plain-file "bashrc"
8451 "alias ls='ls --color=auto'"))))
8454 This yields an @code{etc} directory containing these two files.
8457 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
8458 Return a directory that is the union of @var{things}, where @var{things} is a list of
8459 file-like objects denoting directories. For example:
8462 (directory-union "guile+emacs" (list guile emacs))
8465 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
8468 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
8469 Return a file-like object that expands to the concatenation of @var{obj}
8470 and @var{suffix}, where @var{obj} is a lowerable object and each
8471 @var{suffix} is a string.
8473 As an example, consider this gexp:
8476 (gexp->script "run-uname"
8477 #~(system* #$(file-append coreutils
8481 The same effect could be achieved with:
8484 (gexp->script "run-uname"
8485 #~(system* (string-append #$coreutils
8489 There is one difference though: in the @code{file-append} case, the
8490 resulting script contains the absolute file name as a string, whereas in
8491 the second case, the resulting script contains a @code{(string-append
8492 @dots{})} expression to construct the file name @emph{at run time}.
8495 @deffn {Scheme Syntax} let-system @var{system} @var{body}@dots{}
8496 @deffnx {Scheme Syntax} let-system (@var{system} @var{target}) @var{body}@dots{}
8497 Bind @var{system} to the currently targeted system---e.g.,
8498 @code{"x86_64-linux"}---within @var{body}.
8500 In the second case, additionally bind @var{target} to the current
8501 cross-compilation target---a GNU triplet such as
8502 @code{"arm-linux-gnueabihf"}---or @code{#f} if we are not
8505 @code{let-system} is useful in the occasional case where the object
8506 spliced into the gexp depends on the target system, as in this example:
8510 #+(let-system system
8511 (cond ((string-prefix? "armhf-" system)
8512 (file-append qemu "/bin/qemu-system-arm"))
8513 ((string-prefix? "x86_64-" system)
8514 (file-append qemu "/bin/qemu-system-x86_64"))
8517 "-net" "user" #$image)
8521 @deffn {Scheme Syntax} with-parameters ((@var{parameter} @var{value}) @dots{}) @var{exp}
8522 This macro is similar to the @code{parameterize} form for
8523 dynamically-bound @dfn{parameters} (@pxref{Parameters,,, guile, GNU
8524 Guile Reference Manual}). The key difference is that it takes effect
8525 when the file-like object returned by @var{exp} is lowered to a
8526 derivation or store item.
8528 A typical use of @code{with-parameters} is to force the system in effect
8532 (with-parameters ((%current-system "i686-linux"))
8536 The example above returns an object that corresponds to the i686 build
8537 of Coreutils, regardless of the current value of @code{%current-system}.
8541 Of course, in addition to gexps embedded in ``host'' code, there are
8542 also modules containing build tools. To make it clear that they are
8543 meant to be used in the build stratum, these modules are kept in the
8544 @code{(guix build @dots{})} name space.
8546 @cindex lowering, of high-level objects in gexps
8547 Internally, high-level objects are @dfn{lowered}, using their compiler,
8548 to either derivations or store items. For instance, lowering a package
8549 yields a derivation, and lowering a @code{plain-file} yields a store
8550 item. This is achieved using the @code{lower-object} monadic procedure.
8552 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
8554 Return as a value in @code{%store-monad} the derivation or store item
8555 corresponding to @var{obj} for @var{system}, cross-compiling for
8556 @var{target} if @var{target} is true. @var{obj} must be an object that
8557 has an associated gexp compiler, such as a @code{<package>}.
8560 @node Invoking guix repl
8561 @section Invoking @command{guix repl}
8563 @cindex REPL, read-eval-print loop, script
8564 The @command{guix repl} command makes it easier to program Guix in Guile
8565 by launching a Guile @dfn{read-eval-print loop} (REPL) for interactive
8566 programming (@pxref{Using Guile Interactively,,, guile,
8567 GNU Guile Reference Manual}), or by running Guile scripts
8568 (@pxref{Running Guile Scripts,,, guile,
8569 GNU Guile Reference Manual}).
8570 Compared to just launching the @command{guile}
8571 command, @command{guix repl} guarantees that all the Guix modules and all its
8572 dependencies are available in the search path.
8574 The general syntax is:
8577 guix repl @var{options} [@var{file} @var{args}]
8580 When a @var{file} argument is provided, @var{file} is
8581 executed as a Guile scripts:
8584 guix repl my-script.scm
8587 To pass arguments to the script, use @code{--} to prevent them from
8588 being interpreted as arguments to @command{guix repl} itself:
8591 guix repl -- my-script.scm --input=foo.txt
8594 To make a script executable directly from the shell, using the guix
8595 executable that is on the user's search path, add the following two
8596 lines at the top of the script:
8599 @code{#!/usr/bin/env -S guix repl --}
8603 Without a file name argument, a Guile REPL is started:
8607 scheme@@(guile-user)> ,use (gnu packages base)
8608 scheme@@(guile-user)> coreutils
8609 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
8613 In addition, @command{guix repl} implements a simple machine-readable REPL
8614 protocol for use by @code{(guix inferior)}, a facility to interact with
8615 @dfn{inferiors}, separate processes running a potentially different revision
8618 The available options are as follows:
8621 @item --type=@var{type}
8622 @itemx -t @var{type}
8623 Start a REPL of the given @var{TYPE}, which can be one of the following:
8627 This is default, and it spawns a standard full-featured Guile REPL.
8629 Spawn a REPL that uses the machine-readable protocol. This is the protocol
8630 that the @code{(guix inferior)} module speaks.
8633 @item --listen=@var{endpoint}
8634 By default, @command{guix repl} reads from standard input and writes to
8635 standard output. When this option is passed, it will instead listen for
8636 connections on @var{endpoint}. Here are examples of valid options:
8639 @item --listen=tcp:37146
8640 Accept connections on localhost on port 37146.
8642 @item --listen=unix:/tmp/socket
8643 Accept connections on the Unix-domain socket @file{/tmp/socket}.
8646 @item --load-path=@var{directory}
8647 @itemx -L @var{directory}
8648 Add @var{directory} to the front of the package module search path
8649 (@pxref{Package Modules}).
8651 This allows users to define their own packages and make them visible to
8655 Inhibit loading of the @file{~/.guile} file. By default, that
8656 configuration file is loaded when spawning a @code{guile} REPL.
8659 @c *********************************************************************
8663 This section describes Guix command-line utilities. Some of them are
8664 primarily targeted at developers and users who write new package
8665 definitions, while others are more generally useful. They complement
8666 the Scheme programming interface of Guix in a convenient way.
8669 * Invoking guix build:: Building packages from the command line.
8670 * Invoking guix edit:: Editing package definitions.
8671 * Invoking guix download:: Downloading a file and printing its hash.
8672 * Invoking guix hash:: Computing the cryptographic hash of a file.
8673 * Invoking guix import:: Importing package definitions.
8674 * Invoking guix refresh:: Updating package definitions.
8675 * Invoking guix lint:: Finding errors in package definitions.
8676 * Invoking guix size:: Profiling disk usage.
8677 * Invoking guix graph:: Visualizing the graph of packages.
8678 * Invoking guix publish:: Sharing substitutes.
8679 * Invoking guix challenge:: Challenging substitute servers.
8680 * Invoking guix copy:: Copying to and from a remote store.
8681 * Invoking guix container:: Process isolation.
8682 * Invoking guix weather:: Assessing substitute availability.
8683 * Invoking guix processes:: Listing client processes.
8686 @node Invoking guix build
8687 @section Invoking @command{guix build}
8689 @cindex package building
8690 @cindex @command{guix build}
8691 The @command{guix build} command builds packages or derivations and
8692 their dependencies, and prints the resulting store paths. Note that it
8693 does not modify the user's profile---this is the job of the
8694 @command{guix package} command (@pxref{Invoking guix package}). Thus,
8695 it is mainly useful for distribution developers.
8697 The general syntax is:
8700 guix build @var{options} @var{package-or-derivation}@dots{}
8703 As an example, the following command builds the latest versions of Emacs
8704 and of Guile, displays their build logs, and finally displays the
8705 resulting directories:
8708 guix build emacs guile
8711 Similarly, the following command builds all the available packages:
8714 guix build --quiet --keep-going \
8715 `guix package -A | cut -f1,2 --output-delimiter=@@`
8718 @var{package-or-derivation} may be either the name of a package found in
8719 the software distribution such as @code{coreutils} or
8720 @code{coreutils@@8.20}, or a derivation such as
8721 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
8722 package with the corresponding name (and optionally version) is searched
8723 for among the GNU distribution modules (@pxref{Package Modules}).
8725 Alternatively, the @option{--expression} option may be used to specify a
8726 Scheme expression that evaluates to a package; this is useful when
8727 disambiguating among several same-named packages or package variants is
8730 There may be zero or more @var{options}. The available options are
8731 described in the subsections below.
8734 * Common Build Options:: Build options for most commands.
8735 * Package Transformation Options:: Creating variants of packages.
8736 * Additional Build Options:: Options specific to 'guix build'.
8737 * Debugging Build Failures:: Real life packaging experience.
8740 @node Common Build Options
8741 @subsection Common Build Options
8743 A number of options that control the build process are common to
8744 @command{guix build} and other commands that can spawn builds, such as
8745 @command{guix package} or @command{guix archive}. These are the
8750 @item --load-path=@var{directory}
8751 @itemx -L @var{directory}
8752 Add @var{directory} to the front of the package module search path
8753 (@pxref{Package Modules}).
8755 This allows users to define their own packages and make them visible to
8756 the command-line tools.
8760 Keep the build tree of failed builds. Thus, if a build fails, its build
8761 tree is kept under @file{/tmp}, in a directory whose name is shown at
8762 the end of the build log. This is useful when debugging build issues.
8763 @xref{Debugging Build Failures}, for tips and tricks on how to debug
8766 This option implies @option{--no-offload}, and it has no effect when
8767 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
8768 Store, the @env{GUIX_DAEMON_SOCKET} variable}).
8772 Keep going when some of the derivations fail to build; return only once
8773 all the builds have either completed or failed.
8775 The default behavior is to stop as soon as one of the specified
8776 derivations has failed.
8780 Do not build the derivations.
8782 @anchor{fallback-option}
8784 When substituting a pre-built binary fails, fall back to building
8785 packages locally (@pxref{Substitution Failure}).
8787 @item --substitute-urls=@var{urls}
8788 @anchor{client-substitute-urls}
8789 Consider @var{urls} the whitespace-separated list of substitute source
8790 URLs, overriding the default list of URLs of @command{guix-daemon}
8791 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
8793 This means that substitutes may be downloaded from @var{urls}, provided
8794 they are signed by a key authorized by the system administrator
8795 (@pxref{Substitutes}).
8797 When @var{urls} is the empty string, substitutes are effectively
8800 @item --no-substitutes
8801 Do not use substitutes for build products. That is, always build things
8802 locally instead of allowing downloads of pre-built binaries
8803 (@pxref{Substitutes}).
8806 Do not ``graft'' packages. In practice, this means that package updates
8807 available as grafts are not applied. @xref{Security Updates}, for more
8808 information on grafts.
8810 @item --rounds=@var{n}
8811 Build each derivation @var{n} times in a row, and raise an error if
8812 consecutive build results are not bit-for-bit identical.
8814 This is a useful way to detect non-deterministic builds processes.
8815 Non-deterministic build processes are a problem because they make it
8816 practically impossible for users to @emph{verify} whether third-party
8817 binaries are genuine. @xref{Invoking guix challenge}, for more.
8819 Note that, currently, the differing build results are not kept around,
8820 so you will have to manually investigate in case of an error---e.g., by
8821 stashing one of the build results with @code{guix archive --export}
8822 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
8826 Do not use offload builds to other machines (@pxref{Daemon Offload
8827 Setup}). That is, always build things locally instead of offloading
8828 builds to remote machines.
8830 @item --max-silent-time=@var{seconds}
8831 When the build or substitution process remains silent for more than
8832 @var{seconds}, terminate it and report a build failure.
8834 By default, the daemon's setting is honored (@pxref{Invoking
8835 guix-daemon, @option{--max-silent-time}}).
8837 @item --timeout=@var{seconds}
8838 Likewise, when the build or substitution process lasts for more than
8839 @var{seconds}, terminate it and report a build failure.
8841 By default, the daemon's setting is honored (@pxref{Invoking
8842 guix-daemon, @option{--timeout}}).
8844 @c Note: This option is actually not part of %standard-build-options but
8845 @c most programs honor it.
8846 @cindex verbosity, of the command-line tools
8847 @cindex build logs, verbosity
8848 @item -v @var{level}
8849 @itemx --verbosity=@var{level}
8850 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
8851 output is produced, 1 is for quiet output, and 2 shows all the build log
8852 output on standard error.
8854 @item --cores=@var{n}
8856 Allow the use of up to @var{n} CPU cores for the build. The special
8857 value @code{0} means to use as many CPU cores as available.
8859 @item --max-jobs=@var{n}
8861 Allow at most @var{n} build jobs in parallel. @xref{Invoking
8862 guix-daemon, @option{--max-jobs}}, for details about this option and the
8863 equivalent @command{guix-daemon} option.
8865 @item --debug=@var{level}
8866 Produce debugging output coming from the build daemon. @var{level} must be an
8867 integer between 0 and 5; higher means more verbose output. Setting a level of
8868 4 or more may be helpful when debugging setup issues with the build daemon.
8872 Behind the scenes, @command{guix build} is essentially an interface to
8873 the @code{package-derivation} procedure of the @code{(guix packages)}
8874 module, and to the @code{build-derivations} procedure of the @code{(guix
8875 derivations)} module.
8877 In addition to options explicitly passed on the command line,
8878 @command{guix build} and other @command{guix} commands that support
8879 building honor the @env{GUIX_BUILD_OPTIONS} environment variable.
8881 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
8882 Users can define this variable to a list of command line options that
8883 will automatically be used by @command{guix build} and other
8884 @command{guix} commands that can perform builds, as in the example
8888 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
8891 These options are parsed independently, and the result is appended to
8892 the parsed command-line options.
8896 @node Package Transformation Options
8897 @subsection Package Transformation Options
8899 @cindex package variants
8900 Another set of command-line options supported by @command{guix build}
8901 and also @command{guix package} are @dfn{package transformation
8902 options}. These are options that make it possible to define @dfn{package
8903 variants}---for instance, packages built from different source code.
8904 This is a convenient way to create customized packages on the fly
8905 without having to type in the definitions of package variants
8906 (@pxref{Defining Packages}).
8910 @item --with-source=@var{source}
8911 @itemx --with-source=@var{package}=@var{source}
8912 @itemx --with-source=@var{package}@@@var{version}=@var{source}
8913 Use @var{source} as the source of @var{package}, and @var{version} as
8915 @var{source} must be a file name or a URL, as for @command{guix
8916 download} (@pxref{Invoking guix download}).
8918 When @var{package} is omitted,
8919 it is taken to be the package name specified on the
8920 command line that matches the base of @var{source}---e.g.,
8921 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
8922 package is @code{guile}.
8924 Likewise, when @var{version} is omitted, the version string is inferred from
8925 @var{source}; in the previous example, it is @code{2.0.10}.
8927 This option allows users to try out versions of packages other than the
8928 one provided by the distribution. The example below downloads
8929 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
8930 the @code{ed} package:
8933 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
8936 As a developer, @option{--with-source} makes it easy to test release
8940 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
8943 @dots{} or to build from a checkout in a pristine environment:
8946 $ git clone git://git.sv.gnu.org/guix.git
8947 $ guix build guix --with-source=guix@@1.0=./guix
8950 @item --with-input=@var{package}=@var{replacement}
8951 Replace dependency on @var{package} by a dependency on
8952 @var{replacement}. @var{package} must be a package name, and
8953 @var{replacement} must be a package specification such as @code{guile}
8954 or @code{guile@@1.8}.
8956 For instance, the following command builds Guix, but replaces its
8957 dependency on the current stable version of Guile with a dependency on
8958 the legacy version of Guile, @code{guile@@2.0}:
8961 guix build --with-input=guile=guile@@2.0 guix
8964 This is a recursive, deep replacement. So in this example, both
8965 @code{guix} and its dependency @code{guile-json} (which also depends on
8966 @code{guile}) get rebuilt against @code{guile@@2.0}.
8968 This is implemented using the @code{package-input-rewriting} Scheme
8969 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
8971 @item --with-graft=@var{package}=@var{replacement}
8972 This is similar to @option{--with-input} but with an important difference:
8973 instead of rebuilding the whole dependency chain, @var{replacement} is
8974 built and then @dfn{grafted} onto the binaries that were initially
8975 referring to @var{package}. @xref{Security Updates}, for more
8976 information on grafts.
8978 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
8979 and all its dependencies, replacing references to the version of GnuTLS
8980 they currently refer to:
8983 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
8986 This has the advantage of being much faster than rebuilding everything.
8987 But there is a caveat: it works if and only if @var{package} and
8988 @var{replacement} are strictly compatible---for example, if they provide
8989 a library, the application binary interface (ABI) of those libraries
8990 must be compatible. If @var{replacement} is somehow incompatible with
8991 @var{package}, then the resulting package may be unusable. Use with
8994 @item --with-git-url=@var{package}=@var{url}
8995 @cindex Git, using the latest commit
8996 @cindex latest commit, building
8997 Build @var{package} from the latest commit of the @code{master} branch of the
8998 Git repository at @var{url}. Git sub-modules of the repository are fetched,
9001 For example, the following command builds the NumPy Python library against the
9002 latest commit of the master branch of Python itself:
9005 guix build python-numpy \
9006 --with-git-url=python=https://github.com/python/cpython
9009 This option can also be combined with @option{--with-branch} or
9010 @option{--with-commit} (see below).
9012 @cindex continuous integration
9013 Obviously, since it uses the latest commit of the given branch, the result of
9014 such a command varies over time. Nevertheless it is a convenient way to
9015 rebuild entire software stacks against the latest commit of one or more
9016 packages. This is particularly useful in the context of continuous
9019 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
9020 consecutive accesses to the same repository. You may want to clean it up once
9021 in a while to save disk space.
9023 @item --with-branch=@var{package}=@var{branch}
9024 Build @var{package} from the latest commit of @var{branch}. If the
9025 @code{source} field of @var{package} is an origin with the @code{git-fetch}
9026 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
9027 repository URL is taken from that @code{source}. Otherwise you have to use
9028 @option{--with-git-url} to specify the URL of the Git repository.
9030 For instance, the following command builds @code{guile-sqlite3} from the
9031 latest commit of its @code{master} branch, and then builds @code{guix} (which
9032 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
9033 specific @code{guile-sqlite3} build:
9036 guix build --with-branch=guile-sqlite3=master cuirass
9039 @item --with-commit=@var{package}=@var{commit}
9040 This is similar to @option{--with-branch}, except that it builds from
9041 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
9042 Git commit SHA1 identifier or a tag.
9045 @node Additional Build Options
9046 @subsection Additional Build Options
9048 The command-line options presented below are specific to @command{guix
9055 Build quietly, without displaying the build log; this is equivalent to
9056 @option{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
9057 (or similar) and can always be retrieved using the @option{--log-file} option.
9059 @item --file=@var{file}
9060 @itemx -f @var{file}
9061 Build the package, derivation, or other file-like object that the code within
9062 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
9064 As an example, @var{file} might contain a package definition like this
9065 (@pxref{Defining Packages}):
9068 @include package-hello.scm
9071 The @var{file} may also contain a JSON representation of one or more
9072 package definitions. Running @code{guix build -f} on @file{hello.json}
9073 with the following contents would result in building the packages
9074 @code{myhello} and @code{greeter}:
9077 @verbatiminclude package-hello.json
9080 @item --manifest=@var{manifest}
9081 @itemx -m @var{manifest}
9082 Build all packages listed in the given @var{manifest}
9083 (@pxref{profile-manifest, @option{--manifest}}).
9085 @item --expression=@var{expr}
9086 @itemx -e @var{expr}
9087 Build the package or derivation @var{expr} evaluates to.
9089 For example, @var{expr} may be @code{(@@ (gnu packages guile)
9090 guile-1.8)}, which unambiguously designates this specific variant of
9091 version 1.8 of Guile.
9093 Alternatively, @var{expr} may be a G-expression, in which case it is used
9094 as a build program passed to @code{gexp->derivation}
9095 (@pxref{G-Expressions}).
9097 Lastly, @var{expr} may refer to a zero-argument monadic procedure
9098 (@pxref{The Store Monad}). The procedure must return a derivation as a
9099 monadic value, which is then passed through @code{run-with-store}.
9103 Build the source derivations of the packages, rather than the packages
9106 For instance, @code{guix build -S gcc} returns something like
9107 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
9110 The returned source tarball is the result of applying any patches and
9111 code snippets specified in the package @code{origin} (@pxref{Defining
9114 Note that @command{guix build -S} compiles the sources only of the
9115 specified packages. They do not include the sources of statically
9116 linked dependencies and by themselves are insufficient for reproducing
9120 Fetch and return the source of @var{package-or-derivation} and all their
9121 dependencies, recursively. This is a handy way to obtain a local copy
9122 of all the source code needed to build @var{packages}, allowing you to
9123 eventually build them even without network access. It is an extension
9124 of the @option{--source} option and can accept one of the following
9125 optional argument values:
9129 This value causes the @option{--sources} option to behave in the same way
9130 as the @option{--source} option.
9133 Build the source derivations of all packages, including any source that
9134 might be listed as @code{inputs}. This is the default value.
9137 $ guix build --sources tzdata
9138 The following derivations will be built:
9139 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
9140 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
9144 Build the source derivations of all packages, as well of all transitive
9145 inputs to the packages. This can be used e.g.@: to
9146 prefetch package source for later offline building.
9149 $ guix build --sources=transitive tzdata
9150 The following derivations will be built:
9151 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
9152 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
9153 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
9154 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
9155 /gnu/store/@dots{}-make-4.1.tar.xz.drv
9156 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
9162 @item --system=@var{system}
9163 @itemx -s @var{system}
9164 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
9165 the system type of the build host. The @command{guix build} command allows
9166 you to repeat this option several times, in which case it builds for all the
9167 specified systems; other commands ignore extraneous @option{-s} options.
9170 The @option{--system} flag is for @emph{native} compilation and must not
9171 be confused with cross-compilation. See @option{--target} below for
9172 information on cross-compilation.
9175 An example use of this is on Linux-based systems, which can emulate
9176 different personalities. For instance, passing
9177 @option{--system=i686-linux} on an @code{x86_64-linux} system or
9178 @option{--system=armhf-linux} on an @code{aarch64-linux} system allows
9179 you to build packages in a complete 32-bit environment.
9182 Building for an @code{armhf-linux} system is unconditionally enabled on
9183 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
9184 allow for this functionality, notably the ThunderX.
9187 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
9188 is enabled (@pxref{Virtualization Services,
9189 @code{qemu-binfmt-service-type}}), you can build for any system for
9190 which a QEMU @code{binfmt_misc} handler is installed.
9192 Builds for a system other than that of the machine you are using can
9193 also be offloaded to a remote machine of the right architecture.
9194 @xref{Daemon Offload Setup}, for more information on offloading.
9196 @item --target=@var{triplet}
9197 @cindex cross-compilation
9198 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
9199 as @code{"aarch64-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
9200 configuration triplets,, autoconf, Autoconf}).
9202 @anchor{build-check}
9204 @cindex determinism, checking
9205 @cindex reproducibility, checking
9206 Rebuild @var{package-or-derivation}, which are already available in the
9207 store, and raise an error if the build results are not bit-for-bit
9210 This mechanism allows you to check whether previously installed
9211 substitutes are genuine (@pxref{Substitutes}), or whether the build result
9212 of a package is deterministic. @xref{Invoking guix challenge}, for more
9213 background information and tools.
9215 When used in conjunction with @option{--keep-failed}, the differing
9216 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
9217 This makes it easy to look for differences between the two results.
9220 @cindex repairing store items
9221 @cindex corruption, recovering from
9222 Attempt to repair the specified store items, if they are corrupt, by
9223 re-downloading or rebuilding them.
9225 This operation is not atomic and thus restricted to @code{root}.
9229 Return the derivation paths, not the output paths, of the given
9232 @item --root=@var{file}
9233 @itemx -r @var{file}
9234 @cindex GC roots, adding
9235 @cindex garbage collector roots, adding
9236 Make @var{file} a symlink to the result, and register it as a garbage
9239 Consequently, the results of this @command{guix build} invocation are
9240 protected from garbage collection until @var{file} is removed. When
9241 that option is omitted, build results are eligible for garbage
9242 collection as soon as the build completes. @xref{Invoking guix gc}, for
9246 @cindex build logs, access
9247 Return the build log file names or URLs for the given
9248 @var{package-or-derivation}, or raise an error if build logs are
9251 This works regardless of how packages or derivations are specified. For
9252 instance, the following invocations are equivalent:
9255 guix build --log-file `guix build -d guile`
9256 guix build --log-file `guix build guile`
9257 guix build --log-file guile
9258 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
9261 If a log is unavailable locally, and unless @option{--no-substitutes} is
9262 passed, the command looks for a corresponding log on one of the
9263 substitute servers (as specified with @option{--substitute-urls}).
9265 So for instance, imagine you want to see the build log of GDB on MIPS,
9266 but you are actually on an @code{x86_64} machine:
9269 $ guix build --log-file gdb -s aarch64-linux
9270 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
9273 You can freely access a huge library of build logs!
9276 @node Debugging Build Failures
9277 @subsection Debugging Build Failures
9279 @cindex build failures, debugging
9280 When defining a new package (@pxref{Defining Packages}), you will
9281 probably find yourself spending some time debugging and tweaking the
9282 build until it succeeds. To do that, you need to operate the build
9283 commands yourself in an environment as close as possible to the one the
9286 To that end, the first thing to do is to use the @option{--keep-failed}
9287 or @option{-K} option of @command{guix build}, which will keep the
9288 failed build tree in @file{/tmp} or whatever directory you specified as
9289 @env{TMPDIR} (@pxref{Invoking guix build, @option{--keep-failed}}).
9291 From there on, you can @command{cd} to the failed build tree and source
9292 the @file{environment-variables} file, which contains all the
9293 environment variable definitions that were in place when the build
9294 failed. So let's say you're debugging a build failure in package
9295 @code{foo}; a typical session would look like this:
9299 @dots{} @i{build fails}
9300 $ cd /tmp/guix-build-foo.drv-0
9301 $ source ./environment-variables
9305 Now, you can invoke commands as if you were the daemon (almost) and
9306 troubleshoot your build process.
9308 Sometimes it happens that, for example, a package's tests pass when you
9309 run them manually but they fail when the daemon runs them. This can
9310 happen because the daemon runs builds in containers where, unlike in our
9311 environment above, network access is missing, @file{/bin/sh} does not
9312 exist, etc. (@pxref{Build Environment Setup}).
9314 In such cases, you may need to run inspect the build process from within
9315 a container similar to the one the build daemon creates:
9320 $ cd /tmp/guix-build-foo.drv-0
9321 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
9322 [env]# source ./environment-variables
9326 Here, @command{guix environment -C} creates a container and spawns a new
9327 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
9328 strace gdb} part adds the @command{strace} and @command{gdb} commands to
9329 the container, which you may find handy while debugging. The
9330 @option{--no-grafts} option makes sure we get the exact same
9331 environment, with ungrafted packages (@pxref{Security Updates}, for more
9334 To get closer to a container like that used by the build daemon, we can
9335 remove @file{/bin/sh}:
9341 (Don't worry, this is harmless: this is all happening in the throw-away
9342 container created by @command{guix environment}.)
9344 The @command{strace} command is probably not in the search path, but we
9348 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
9351 In this way, not only you will have reproduced the environment variables
9352 the daemon uses, you will also be running the build process in a container
9353 similar to the one the daemon uses.
9356 @node Invoking guix edit
9357 @section Invoking @command{guix edit}
9359 @cindex @command{guix edit}
9360 @cindex package definition, editing
9361 So many packages, so many source files! The @command{guix edit} command
9362 facilitates the life of users and packagers by pointing their editor at
9363 the source file containing the definition of the specified packages.
9367 guix edit gcc@@4.9 vim
9371 launches the program specified in the @env{VISUAL} or in the
9372 @env{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
9375 If you are using a Guix Git checkout (@pxref{Building from Git}), or
9376 have created your own packages on @env{GUIX_PACKAGE_PATH}
9377 (@pxref{Package Modules}), you will be able to edit the package
9378 recipes. In other cases, you will be able to examine the read-only recipes
9379 for packages currently in the store.
9381 Instead of @env{GUIX_PACKAGE_PATH}, the command-line option
9382 @option{--load-path=@var{directory}} (or in short @option{-L
9383 @var{directory}}) allows you to add @var{directory} to the front of the
9384 package module search path and so make your own packages visible.
9386 @node Invoking guix download
9387 @section Invoking @command{guix download}
9389 @cindex @command{guix download}
9390 @cindex downloading package sources
9391 When writing a package definition, developers typically need to download
9392 a source tarball, compute its SHA256 hash, and write that
9393 hash in the package definition (@pxref{Defining Packages}). The
9394 @command{guix download} tool helps with this task: it downloads a file
9395 from the given URI, adds it to the store, and prints both its file name
9396 in the store and its SHA256 hash.
9398 The fact that the downloaded file is added to the store saves bandwidth:
9399 when the developer eventually tries to build the newly defined package
9400 with @command{guix build}, the source tarball will not have to be
9401 downloaded again because it is already in the store. It is also a
9402 convenient way to temporarily stash files, which may be deleted
9403 eventually (@pxref{Invoking guix gc}).
9405 The @command{guix download} command supports the same URIs as used in
9406 package definitions. In particular, it supports @code{mirror://} URIs.
9407 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
9408 Guile bindings for GnuTLS are available in the user's environment; when
9409 they are not available, an error is raised. @xref{Guile Preparations,
9410 how to install the GnuTLS bindings for Guile,, gnutls-guile,
9411 GnuTLS-Guile}, for more information.
9413 @command{guix download} verifies HTTPS server certificates by loading
9414 the certificates of X.509 authorities from the directory pointed to by
9415 the @env{SSL_CERT_DIR} environment variable (@pxref{X.509
9416 Certificates}), unless @option{--no-check-certificate} is used.
9418 The following options are available:
9421 @item --hash=@var{algorithm}
9422 @itemx -H @var{algorithm}
9423 Compute a hash using the specified @var{algorithm}. @xref{Invoking guix
9424 hash}, for more information.
9426 @item --format=@var{fmt}
9428 Write the hash in the format specified by @var{fmt}. For more
9429 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
9431 @item --no-check-certificate
9432 Do not validate the X.509 certificates of HTTPS servers.
9434 When using this option, you have @emph{absolutely no guarantee} that you
9435 are communicating with the authentic server responsible for the given
9436 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
9438 @item --output=@var{file}
9439 @itemx -o @var{file}
9440 Save the downloaded file to @var{file} instead of adding it to the
9444 @node Invoking guix hash
9445 @section Invoking @command{guix hash}
9447 @cindex @command{guix hash}
9448 The @command{guix hash} command computes the hash of a file.
9449 It is primarily a convenience tool for anyone contributing to the
9450 distribution: it computes the cryptographic hash of a file, which can be
9451 used in the definition of a package (@pxref{Defining Packages}).
9453 The general syntax is:
9456 guix hash @var{option} @var{file}
9459 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
9460 hash of data read from standard input. @command{guix hash} has the
9465 @item --hash=@var{algorithm}
9466 @itemx -H @var{algorithm}
9467 Compute a hash using the specified @var{algorithm}, @code{sha256} by
9470 @var{algorithm} must the name of a cryptographic hash algorithm
9471 supported by Libgcrypt @i{via} Guile-Gcrypt---e.g., @code{sha512} or
9472 @code{sha3-256} (@pxref{Hash Functions,,, guile-gcrypt, Guile-Gcrypt
9475 @item --format=@var{fmt}
9477 Write the hash in the format specified by @var{fmt}.
9479 Supported formats: @code{base64}, @code{nix-base32}, @code{base32}, @code{base16}
9480 (@code{hex} and @code{hexadecimal} can be used as well).
9482 If the @option{--format} option is not specified, @command{guix hash}
9483 will output the hash in @code{nix-base32}. This representation is used
9484 in the definitions of packages.
9488 Compute the hash on @var{file} recursively.
9490 In this case, the hash is computed on an archive containing @var{file},
9491 including its children if it is a directory. Some of the metadata of
9492 @var{file} is part of the archive; for instance, when @var{file} is a
9493 regular file, the hash is different depending on whether @var{file} is
9494 executable or not. Metadata such as time stamps has no impact on the
9495 hash (@pxref{Invoking guix archive}).
9496 @c FIXME: Replace xref above with xref to an ``Archive'' section when
9501 When combined with @option{--recursive}, exclude version control system
9502 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.).
9505 As an example, here is how you would compute the hash of a Git checkout,
9506 which is useful when using the @code{git-fetch} method (@pxref{origin
9510 $ git clone http://example.org/foo.git
9516 @node Invoking guix import
9517 @section Invoking @command{guix import}
9519 @cindex importing packages
9520 @cindex package import
9521 @cindex package conversion
9522 @cindex Invoking @command{guix import}
9523 The @command{guix import} command is useful for people who would like to
9524 add a package to the distribution with as little work as
9525 possible---a legitimate demand. The command knows of a few
9526 repositories from which it can ``import'' package metadata. The result
9527 is a package definition, or a template thereof, in the format we know
9528 (@pxref{Defining Packages}).
9530 The general syntax is:
9533 guix import @var{importer} @var{options}@dots{}
9536 @var{importer} specifies the source from which to import package
9537 metadata, and @var{options} specifies a package identifier and other
9538 options specific to @var{importer}.
9540 Some of the importers rely on the ability to run the @command{gpgv} command.
9541 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
9544 Currently, the available ``importers'' are:
9548 Import metadata for the given GNU package. This provides a template
9549 for the latest version of that GNU package, including the hash of its
9550 source tarball, and its canonical synopsis and description.
9552 Additional information such as the package dependencies and its
9553 license needs to be figured out manually.
9555 For example, the following command returns a package definition for
9559 guix import gnu hello
9562 Specific command-line options are:
9565 @item --key-download=@var{policy}
9566 As for @command{guix refresh}, specify the policy to handle missing
9567 OpenPGP keys when verifying the package signature. @xref{Invoking guix
9568 refresh, @option{--key-download}}.
9573 Import metadata from the @uref{https://pypi.python.org/, Python Package
9574 Index}. Information is taken from the JSON-formatted description
9575 available at @code{pypi.python.org} and usually includes all the relevant
9576 information, including package dependencies. For maximum efficiency, it
9577 is recommended to install the @command{unzip} utility, so that the
9578 importer can unzip Python wheels and gather data from them.
9580 The command below imports metadata for the @code{itsdangerous} Python
9584 guix import pypi itsdangerous
9590 Traverse the dependency graph of the given upstream package recursively
9591 and generate package expressions for all those packages that are not yet
9597 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
9598 is taken from the JSON-formatted description available at
9599 @code{rubygems.org} and includes most relevant information, including
9600 runtime dependencies. There are some caveats, however. The metadata
9601 doesn't distinguish between synopses and descriptions, so the same string
9602 is used for both fields. Additionally, the details of non-Ruby
9603 dependencies required to build native extensions is unavailable and left
9604 as an exercise to the packager.
9606 The command below imports metadata for the @code{rails} Ruby package:
9609 guix import gem rails
9615 Traverse the dependency graph of the given upstream package recursively
9616 and generate package expressions for all those packages that are not yet
9622 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
9623 Information is taken from the JSON-formatted metadata provided through
9624 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
9625 relevant information, such as module dependencies. License information
9626 should be checked closely. If Perl is available in the store, then the
9627 @code{corelist} utility will be used to filter core modules out of the
9628 list of dependencies.
9630 The command command below imports metadata for the Acme::Boolean Perl
9634 guix import cpan Acme::Boolean
9639 @cindex Bioconductor
9640 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
9641 central repository for the @uref{https://r-project.org, GNU@tie{}R
9642 statistical and graphical environment}.
9644 Information is extracted from the @file{DESCRIPTION} file of the package.
9646 The command command below imports metadata for the Cairo R package:
9649 guix import cran Cairo
9652 When @option{--recursive} is added, the importer will traverse the
9653 dependency graph of the given upstream package recursively and generate
9654 package expressions for all those packages that are not yet in Guix.
9656 When @option{--archive=bioconductor} is added, metadata is imported from
9657 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
9658 packages for for the analysis and comprehension of high-throughput
9659 genomic data in bioinformatics.
9661 Information is extracted from the @file{DESCRIPTION} file contained in the
9664 The command below imports metadata for the GenomicRanges R package:
9667 guix import cran --archive=bioconductor GenomicRanges
9670 Finally, you can also import R packages that have not yet been published on
9671 CRAN or Bioconductor as long as they are in a git repository. Use
9672 @option{--archive=git} followed by the URL of the git repository:
9675 guix import cran --archive=git https://github.com/immunogenomics/harmony
9681 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
9682 comprehensive TeX archive network for TeX packages that are part of the
9683 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
9685 Information about the package is obtained through the XML API provided
9686 by CTAN, while the source code is downloaded from the SVN repository of
9687 the Tex Live project. This is done because the CTAN does not keep
9690 The command command below imports metadata for the @code{fontspec}
9694 guix import texlive fontspec
9697 When @option{--archive=@var{directory}} is added, the source code is
9698 downloaded not from the @file{latex} sub-directory of the
9699 @file{texmf-dist/source} tree in the TeX Live SVN repository, but from
9700 the specified sibling @var{directory} under the same root.
9702 The command below imports metadata for the @code{ifxetex} package from
9703 CTAN while fetching the sources from the directory
9704 @file{texmf/source/generic}:
9707 guix import texlive --archive=generic ifxetex
9711 @cindex JSON, import
9712 Import package metadata from a local JSON file. Consider the following
9713 example package definition in JSON format:
9719 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
9720 "build-system": "gnu",
9721 "home-page": "https://www.gnu.org/software/hello/",
9722 "synopsis": "Hello, GNU world: An example GNU package",
9723 "description": "GNU Hello prints a greeting.",
9724 "license": "GPL-3.0+",
9725 "native-inputs": ["gettext"]
9729 The field names are the same as for the @code{<package>} record
9730 (@xref{Defining Packages}). References to other packages are provided
9731 as JSON lists of quoted package specification strings such as
9732 @code{guile} or @code{guile@@2.0}.
9734 The importer also supports a more explicit source definition using the
9735 common fields for @code{<origin>} records:
9741 "method": "url-fetch",
9742 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
9744 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
9751 The command below reads metadata from the JSON file @code{hello.json}
9752 and outputs a package expression:
9755 guix import json hello.json
9759 Import metadata from a local copy of the source of the
9760 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
9761 relies on the @command{nix-instantiate} command of
9762 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
9763 typically written in a mixture of Nix-language and Bash code. This
9764 command only imports the high-level package structure that is written in
9765 the Nix language. It normally includes all the basic fields of a
9768 When importing a GNU package, the synopsis and descriptions are replaced
9769 by their canonical upstream variant.
9771 Usually, you will first need to do:
9774 export NIX_REMOTE=daemon
9778 so that @command{nix-instantiate} does not try to open the Nix database.
9780 As an example, the command below imports the package definition of
9781 LibreOffice (more precisely, it imports the definition of the package
9782 bound to the @code{libreoffice} top-level attribute):
9785 guix import nix ~/path/to/nixpkgs libreoffice
9790 Import metadata from the Haskell community's central package archive
9791 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
9792 Cabal files and includes all the relevant information, including package
9795 Specific command-line options are:
9800 Read a Cabal file from standard input.
9801 @item --no-test-dependencies
9803 Do not include dependencies required only by the test suites.
9804 @item --cabal-environment=@var{alist}
9805 @itemx -e @var{alist}
9806 @var{alist} is a Scheme alist defining the environment in which the
9807 Cabal conditionals are evaluated. The accepted keys are: @code{os},
9808 @code{arch}, @code{impl} and a string representing the name of a flag.
9809 The value associated with a flag has to be either the symbol
9810 @code{true} or @code{false}. The value associated with other keys
9811 has to conform to the Cabal file format definition. The default value
9812 associated with the keys @code{os}, @code{arch} and @code{impl} is
9813 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
9816 Traverse the dependency graph of the given upstream package recursively
9817 and generate package expressions for all those packages that are not yet
9821 The command below imports metadata for the latest version of the
9822 HTTP Haskell package without including test dependencies and
9823 specifying the value of the flag @samp{network-uri} as @code{false}:
9826 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
9829 A specific package version may optionally be specified by following the
9830 package name by an at-sign and a version number as in the following example:
9833 guix import hackage mtl@@2.1.3.1
9838 The @code{stackage} importer is a wrapper around the @code{hackage} one.
9839 It takes a package name, looks up the package version included in a
9840 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
9841 release and uses the @code{hackage} importer to retrieve its metadata.
9842 Note that it is up to you to select an LTS release compatible with the
9843 GHC compiler used by Guix.
9845 Specific command-line options are:
9848 @item --no-test-dependencies
9850 Do not include dependencies required only by the test suites.
9851 @item --lts-version=@var{version}
9852 @itemx -l @var{version}
9853 @var{version} is the desired LTS release version. If omitted the latest
9857 Traverse the dependency graph of the given upstream package recursively
9858 and generate package expressions for all those packages that are not yet
9862 The command below imports metadata for the HTTP Haskell package
9863 included in the LTS Stackage release version 7.18:
9866 guix import stackage --lts-version=7.18 HTTP
9871 Import metadata from an Emacs Lisp Package Archive (ELPA) package
9872 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
9874 Specific command-line options are:
9877 @item --archive=@var{repo}
9878 @itemx -a @var{repo}
9879 @var{repo} identifies the archive repository from which to retrieve the
9880 information. Currently the supported repositories and their identifiers
9884 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
9885 identifier. This is the default.
9887 Packages from @code{elpa.gnu.org} are signed with one of the keys
9888 contained in the GnuPG keyring at
9889 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
9890 @code{emacs} package (@pxref{Package Installation, ELPA package
9891 signatures,, emacs, The GNU Emacs Manual}).
9894 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
9895 @code{melpa-stable} identifier.
9898 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
9904 Traverse the dependency graph of the given upstream package recursively
9905 and generate package expressions for all those packages that are not yet
9911 Import metadata from the crates.io Rust package repository
9912 @uref{https://crates.io, crates.io}, as in this example:
9915 guix import crate blake2-rfc
9918 The crate importer also allows you to specify a version string:
9921 guix import crate constant-time-eq@@0.1.0
9924 Additional options include:
9929 Traverse the dependency graph of the given upstream package recursively
9930 and generate package expressions for all those packages that are not yet
9937 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
9938 repository used by the OCaml community.
9941 The structure of the @command{guix import} code is modular. It would be
9942 useful to have more importers for other package formats, and your help
9943 is welcome here (@pxref{Contributing}).
9945 @node Invoking guix refresh
9946 @section Invoking @command{guix refresh}
9948 @cindex @command {guix refresh}
9949 The primary audience of the @command{guix refresh} command is developers
9950 of the GNU software distribution. By default, it reports any packages
9951 provided by the distribution that are outdated compared to the latest
9952 upstream version, like this:
9956 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
9957 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
9960 Alternatively, one can specify packages to consider, in which case a
9961 warning is emitted for packages that lack an updater:
9964 $ guix refresh coreutils guile guile-ssh
9965 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
9966 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
9969 @command{guix refresh} browses the upstream repository of each package and determines
9970 the highest version number of the releases therein. The command
9971 knows how to update specific types of packages: GNU packages, ELPA
9972 packages, etc.---see the documentation for @option{--type} below. There
9973 are many packages, though, for which it lacks a method to determine
9974 whether a new upstream release is available. However, the mechanism is
9975 extensible, so feel free to get in touch with us to add a new method!
9980 Consider the packages specified, and all the packages upon which they depend.
9983 $ guix refresh --recursive coreutils
9984 gnu/packages/acl.scm:35:2: warning: no updater for acl
9985 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
9986 gnu/packages/xml.scm:68:2: warning: no updater for expat
9987 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
9993 Sometimes the upstream name differs from the package name used in Guix,
9994 and @command{guix refresh} needs a little help. Most updaters honor the
9995 @code{upstream-name} property in package definitions, which can be used
9999 (define-public network-manager
10001 (name "network-manager")
10003 (properties '((upstream-name . "NetworkManager")))))
10006 When passed @option{--update}, it modifies distribution source files to
10007 update the version numbers and source tarball hashes of those package
10008 recipes (@pxref{Defining Packages}). This is achieved by downloading
10009 each package's latest source tarball and its associated OpenPGP
10010 signature, authenticating the downloaded tarball against its signature
10011 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
10012 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
10015 key used to sign the tarball is missing from the user's keyring, an
10016 attempt is made to automatically retrieve it from a public key server;
10017 when this is successful, the key is added to the user's keyring; otherwise,
10018 @command{guix refresh} reports an error.
10020 The following options are supported:
10024 @item --expression=@var{expr}
10025 @itemx -e @var{expr}
10026 Consider the package @var{expr} evaluates to.
10028 This is useful to precisely refer to a package, as in this example:
10031 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
10034 This command lists the dependents of the ``final'' libc (essentially all
10039 Update distribution source files (package recipes) in place. This is
10040 usually run from a checkout of the Guix source tree (@pxref{Running
10041 Guix Before It Is Installed}):
10044 $ ./pre-inst-env guix refresh -s non-core -u
10047 @xref{Defining Packages}, for more information on package definitions.
10049 @item --select=[@var{subset}]
10050 @itemx -s @var{subset}
10051 Select all the packages in @var{subset}, one of @code{core} or
10054 The @code{core} subset refers to all the packages at the core of the
10055 distribution---i.e., packages that are used to build ``everything
10056 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
10057 changing one of these packages in the distribution entails a rebuild of
10058 all the others. Thus, such updates are an inconvenience to users in
10059 terms of build time or bandwidth used to achieve the upgrade.
10061 The @code{non-core} subset refers to the remaining packages. It is
10062 typically useful in cases where an update of the core packages would be
10065 @item --manifest=@var{file}
10066 @itemx -m @var{file}
10067 Select all the packages from the manifest in @var{file}. This is useful to
10068 check if any packages of the user manifest can be updated.
10070 @item --type=@var{updater}
10071 @itemx -t @var{updater}
10072 Select only packages handled by @var{updater} (may be a comma-separated
10073 list of updaters). Currently, @var{updater} may be one of:
10077 the updater for GNU packages;
10079 the updater for packages hosted at @uref{https://savannah.gnu.org, Savannah};
10081 the updater for GNOME packages;
10083 the updater for KDE packages;
10085 the updater for X.org packages;
10087 the updater for packages hosted on kernel.org;
10089 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
10091 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
10093 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
10095 the updater for @uref{https://www.cpan.org/, CPAN} packages;
10097 the updater for @uref{https://pypi.python.org, PyPI} packages.
10099 the updater for @uref{https://rubygems.org, RubyGems} packages.
10101 the updater for @uref{https://github.com, GitHub} packages.
10103 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
10105 the updater for @uref{https://www.stackage.org, Stackage} packages.
10107 the updater for @uref{https://crates.io, Crates} packages.
10109 the updater for @uref{https://launchpad.net, Launchpad} packages.
10112 For instance, the following command only checks for updates of Emacs
10113 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
10116 $ guix refresh --type=elpa,cran
10117 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
10118 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
10123 In addition, @command{guix refresh} can be passed one or more package
10124 names, as in this example:
10127 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
10131 The command above specifically updates the @code{emacs} and
10132 @code{idutils} packages. The @option{--select} option would have no
10133 effect in this case.
10135 When considering whether to upgrade a package, it is sometimes
10136 convenient to know which packages would be affected by the upgrade and
10137 should be checked for compatibility. For this the following option may
10138 be used when passing @command{guix refresh} one or more package names:
10142 @item --list-updaters
10144 List available updaters and exit (see @option{--type} above).
10146 For each updater, display the fraction of packages it covers; at the
10147 end, display the fraction of packages covered by all these updaters.
10149 @item --list-dependent
10151 List top-level dependent packages that would need to be rebuilt as a
10152 result of upgrading one or more packages.
10154 @xref{Invoking guix graph, the @code{reverse-package} type of
10155 @command{guix graph}}, for information on how to visualize the list of
10156 dependents of a package.
10160 Be aware that the @option{--list-dependent} option only
10161 @emph{approximates} the rebuilds that would be required as a result of
10162 an upgrade. More rebuilds might be required under some circumstances.
10165 $ guix refresh --list-dependent flex
10166 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
10167 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
10170 The command above lists a set of packages that could be built to check
10171 for compatibility with an upgraded @code{flex} package.
10175 @item --list-transitive
10176 List all the packages which one or more packages depend upon.
10179 $ guix refresh --list-transitive flex
10180 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
10181 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{}
10186 The command above lists a set of packages which, when changed, would cause
10187 @code{flex} to be rebuilt.
10189 The following options can be used to customize GnuPG operation:
10193 @item --gpg=@var{command}
10194 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
10195 for in @code{$PATH}.
10197 @item --keyring=@var{file}
10198 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
10199 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
10200 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
10201 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
10202 information on a tool to manipulate keybox files).
10204 When this option is omitted, @command{guix refresh} uses
10205 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
10206 signing keys. OpenPGP signatures are checked against keys from this keyring;
10207 missing keys are downloaded to this keyring as well (see
10208 @option{--key-download} below).
10210 You can export keys from your default GPG keyring into a keybox file using
10211 commands like this one:
10214 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
10217 Likewise, you can fetch keys to a specific keybox file like this:
10220 gpg --no-default-keyring --keyring mykeyring.kbx \
10221 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
10224 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
10225 Privacy Guard}, for more information on GPG's @option{--keyring} option.
10227 @item --key-download=@var{policy}
10228 Handle missing OpenPGP keys according to @var{policy}, which may be one
10233 Always download missing OpenPGP keys from the key server, and add them
10234 to the user's GnuPG keyring.
10237 Never try to download missing OpenPGP keys. Instead just bail out.
10240 When a package signed with an unknown OpenPGP key is encountered, ask
10241 the user whether to download it or not. This is the default behavior.
10244 @item --key-server=@var{host}
10245 Use @var{host} as the OpenPGP key server when importing a public key.
10247 @item --load-path=@var{directory}
10248 Add @var{directory} to the front of the package module search path
10249 (@pxref{Package Modules}).
10251 This allows users to define their own packages and make them visible to
10252 the command-line tools.
10256 The @code{github} updater uses the
10257 @uref{https://developer.github.com/v3/, GitHub API} to query for new
10258 releases. When used repeatedly e.g.@: when refreshing all packages,
10259 GitHub will eventually refuse to answer any further API requests. By
10260 default 60 API requests per hour are allowed, and a full refresh on all
10261 GitHub packages in Guix requires more than this. Authentication with
10262 GitHub through the use of an API token alleviates these limits. To use
10263 an API token, set the environment variable @env{GUIX_GITHUB_TOKEN} to a
10264 token procured from @uref{https://github.com/settings/tokens} or
10268 @node Invoking guix lint
10269 @section Invoking @command{guix lint}
10271 @cindex @command{guix lint}
10272 @cindex package, checking for errors
10273 The @command{guix lint} command is meant to help package developers avoid
10274 common errors and use a consistent style. It runs a number of checks on
10275 a given set of packages in order to find common mistakes in their
10276 definitions. Available @dfn{checkers} include (see
10277 @option{--list-checkers} for a complete list):
10282 Validate certain typographical and stylistic rules about package
10283 descriptions and synopses.
10285 @item inputs-should-be-native
10286 Identify inputs that should most likely be native inputs.
10292 @itemx source-file-name
10293 Probe @code{home-page} and @code{source} URLs and report those that are
10294 invalid. Suggest a @code{mirror://} URL when applicable. If the
10295 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
10296 URL. Check that the source file name is meaningful, e.g.@: is not just a
10297 version number or ``git-checkout'', without a declared @code{file-name}
10298 (@pxref{origin Reference}).
10300 @item source-unstable-tarball
10301 Parse the @code{source} URL to determine if a tarball from GitHub is
10302 autogenerated or if it is a release tarball. Unfortunately GitHub's
10303 autogenerated tarballs are sometimes regenerated.
10306 Check that the derivation of the given packages can be successfully
10307 computed for all the supported systems (@pxref{Derivations}).
10309 @item profile-collisions
10310 Check whether installing the given packages in a profile would lead to
10311 collisions. Collisions occur when several packages with the same name
10312 but a different version or a different store file name are propagated.
10313 @xref{package Reference, @code{propagated-inputs}}, for more information
10314 on propagated inputs.
10317 @cindex Software Heritage, source code archive
10318 @cindex archival of source code, Software Heritage
10319 Checks whether the package's source code is archived at
10320 @uref{https://www.softwareheritage.org, Software Heritage}.
10322 When the source code that is not archived comes from a version-control system
10323 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
10324 ``save'' request so that it eventually archives it. This ensures that the
10325 source will remain available in the long term, and that Guix can fall back to
10326 Software Heritage should the source code disappear from its original host.
10327 The status of recent ``save'' requests can be
10328 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
10330 When source code is a tarball obtained with @code{url-fetch}, simply print a
10331 message when it is not archived. As of this writing, Software Heritage does
10332 not allow requests to save arbitrary tarballs; we are working on ways to
10333 ensure that non-VCS source code is also archived.
10336 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
10337 request rate per IP address}. When the limit is reached, @command{guix lint}
10338 prints a message and the @code{archival} checker stops doing anything until
10339 that limit has been reset.
10342 @cindex security vulnerabilities
10343 @cindex CVE, Common Vulnerabilities and Exposures
10344 Report known vulnerabilities found in the Common Vulnerabilities and
10345 Exposures (CVE) databases of the current and past year
10346 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
10349 To view information about a particular vulnerability, visit pages such as:
10353 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
10355 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
10359 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
10360 @code{CVE-2015-7554}.
10362 Package developers can specify in package recipes the
10363 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
10364 name and version of the package when they differ from the name or version
10365 that Guix uses, as in this example:
10371 ;; CPE calls this package "grub2".
10372 (properties '((cpe-name . "grub2")
10373 (cpe-version . "2.3"))))
10376 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
10377 Some entries in the CVE database do not specify which version of a
10378 package they apply to, and would thus ``stick around'' forever. Package
10379 developers who found CVE alerts and verified they can be ignored can
10380 declare them as in this example:
10386 ;; These CVEs no longer apply and can be safely ignored.
10387 (properties `((lint-hidden-cve . ("CVE-2011-0433"
10390 "CVE-2011-5244")))))
10394 Warn about obvious source code formatting issues: trailing white space,
10395 use of tabulations, etc.
10398 The general syntax is:
10401 guix lint @var{options} @var{package}@dots{}
10404 If no package is given on the command line, then all packages are checked.
10405 The @var{options} may be zero or more of the following:
10408 @item --list-checkers
10410 List and describe all the available checkers that will be run on packages
10415 Only enable the checkers specified in a comma-separated list using the
10416 names returned by @option{--list-checkers}.
10418 @item --load-path=@var{directory}
10419 @itemx -L @var{directory}
10420 Add @var{directory} to the front of the package module search path
10421 (@pxref{Package Modules}).
10423 This allows users to define their own packages and make them visible to
10424 the command-line tools.
10428 @node Invoking guix size
10429 @section Invoking @command{guix size}
10432 @cindex package size
10434 @cindex @command{guix size}
10435 The @command{guix size} command helps package developers profile the
10436 disk usage of packages. It is easy to overlook the impact of an
10437 additional dependency added to a package, or the impact of using a
10438 single output for a package that could easily be split (@pxref{Packages
10439 with Multiple Outputs}). Such are the typical issues that
10440 @command{guix size} can highlight.
10442 The command can be passed one or more package specifications
10443 such as @code{gcc@@4.8}
10444 or @code{guile:debug}, or a file name in the store. Consider this
10448 $ guix size coreutils
10449 store item total self
10450 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
10451 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
10452 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
10453 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
10454 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
10455 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
10456 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
10457 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
10462 The store items listed here constitute the @dfn{transitive closure} of
10463 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
10464 would be returned by:
10467 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
10470 Here the output shows three columns next to store items. The first column,
10471 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
10472 the store item---that is, its own size plus the size of all its
10473 dependencies. The next column, labeled ``self'', shows the size of the
10474 item itself. The last column shows the ratio of the size of the item
10475 itself to the space occupied by all the items listed here.
10477 In this example, we see that the closure of Coreutils weighs in at
10478 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
10479 libraries. (That libc and GCC's libraries represent a large fraction of
10480 the closure is not a problem @i{per se} because they are always available
10481 on the system anyway.)
10483 Since the command also accepts store file names, assessing the size of
10484 a build result is straightforward:
10487 guix size $(guix system build config.scm)
10490 When the package(s) passed to @command{guix size} are available in the
10491 store@footnote{More precisely, @command{guix size} looks for the
10492 @emph{ungrafted} variant of the given package(s), as returned by
10493 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
10494 for information on grafts.}, @command{guix size} queries the daemon to determine its
10495 dependencies, and measures its size in the store, similar to @command{du
10496 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
10499 When the given packages are @emph{not} in the store, @command{guix size}
10500 reports information based on the available substitutes
10501 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
10502 store items that are not even on disk, only available remotely.
10504 You can also specify several package names:
10507 $ guix size coreutils grep sed bash
10508 store item total self
10509 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
10510 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
10511 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
10512 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
10518 In this example we see that the combination of the four packages takes
10519 102.3@tie{}MiB in total, which is much less than the sum of each closure
10520 since they have a lot of dependencies in common.
10522 When looking at the profile returned by @command{guix size}, you may
10523 find yourself wondering why a given package shows up in the profile at
10524 all. To understand it, you can use @command{guix graph --path -t
10525 references} to display the shortest path between the two packages
10526 (@pxref{Invoking guix graph}).
10528 The available options are:
10532 @item --substitute-urls=@var{urls}
10533 Use substitute information from @var{urls}.
10534 @xref{client-substitute-urls, the same option for @code{guix build}}.
10536 @item --sort=@var{key}
10537 Sort lines according to @var{key}, one of the following options:
10541 the size of each item (the default);
10543 the total size of the item's closure.
10546 @item --map-file=@var{file}
10547 Write a graphical map of disk usage in PNG format to @var{file}.
10549 For the example above, the map looks like this:
10551 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
10552 produced by @command{guix size}}
10554 This option requires that
10555 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
10556 installed and visible in Guile's module search path. When that is not
10557 the case, @command{guix size} fails as it tries to load it.
10559 @item --system=@var{system}
10560 @itemx -s @var{system}
10561 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
10563 @item --load-path=@var{directory}
10564 @itemx -L @var{directory}
10565 Add @var{directory} to the front of the package module search path
10566 (@pxref{Package Modules}).
10568 This allows users to define their own packages and make them visible to
10569 the command-line tools.
10572 @node Invoking guix graph
10573 @section Invoking @command{guix graph}
10576 @cindex @command{guix graph}
10577 @cindex package dependencies
10578 Packages and their dependencies form a @dfn{graph}, specifically a
10579 directed acyclic graph (DAG). It can quickly become difficult to have a
10580 mental model of the package DAG, so the @command{guix graph} command
10581 provides a visual representation of the DAG. By default,
10582 @command{guix graph} emits a DAG representation in the input format of
10583 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
10584 directly to the @command{dot} command of Graphviz. It can also emit an
10585 HTML page with embedded JavaScript code to display a ``chord diagram''
10586 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
10587 emit Cypher queries to construct a graph in a graph database supporting
10588 the @uref{https://www.opencypher.org/, openCypher} query language. With
10589 @option{--path}, it simply displays the shortest path between two
10590 packages. The general syntax is:
10593 guix graph @var{options} @var{package}@dots{}
10596 For example, the following command generates a PDF file representing the
10597 package DAG for the GNU@tie{}Core Utilities, showing its build-time
10601 guix graph coreutils | dot -Tpdf > dag.pdf
10604 The output looks like this:
10606 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
10608 Nice little graph, no?
10610 You may find it more pleasant to navigate the graph interactively with
10611 @command{xdot} (from the @code{xdot} package):
10614 guix graph coreutils | xdot -
10617 But there is more than one graph! The one above is concise: it is the
10618 graph of package objects, omitting implicit inputs such as GCC, libc,
10619 grep, etc. It is often useful to have such a concise graph, but
10620 sometimes one may want to see more details. @command{guix graph} supports
10621 several types of graphs, allowing you to choose the level of detail:
10625 This is the default type used in the example above. It shows the DAG of
10626 package objects, excluding implicit dependencies. It is concise, but
10627 filters out many details.
10629 @item reverse-package
10630 This shows the @emph{reverse} DAG of packages. For example:
10633 guix graph --type=reverse-package ocaml
10636 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
10637 you are also interested in cases where OCaml is an implicit dependency, see
10638 @code{reverse-bag} below).
10640 Note that for core packages this can yield huge graphs. If all you want
10641 is to know the number of packages that depend on a given package, use
10642 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
10643 @option{--list-dependent}}).
10646 This is the package DAG, @emph{including} implicit inputs.
10648 For instance, the following command:
10651 guix graph --type=bag-emerged coreutils
10654 ...@: yields this bigger graph:
10656 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
10658 At the bottom of the graph, we see all the implicit inputs of
10659 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
10661 Now, note that the dependencies of these implicit inputs---that is, the
10662 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
10663 here, for conciseness.
10666 Similar to @code{bag-emerged}, but this time including all the bootstrap
10669 @item bag-with-origins
10670 Similar to @code{bag}, but also showing origins and their dependencies.
10673 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
10674 it also takes implicit dependencies into account. For example:
10677 guix graph -t reverse-bag dune
10681 ...@: yields the graph of all packages that depend on Dune, directly or
10682 indirectly. Since Dune is an @emph{implicit} dependency of many packages
10683 @i{via} @code{dune-build-system}, this shows a large number of packages,
10684 whereas @code{reverse-package} would show very few if any.
10687 This is the most detailed representation: It shows the DAG of
10688 derivations (@pxref{Derivations}) and plain store items. Compared to
10689 the above representation, many additional nodes are visible, including
10690 build scripts, patches, Guile modules, etc.
10692 For this type of graph, it is also possible to pass a @file{.drv} file
10693 name instead of a package name, as in:
10696 guix graph -t derivation `guix system build -d my-config.scm`
10700 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
10701 For example, the following command shows the graph for the package
10702 module that defines the @code{guile} package:
10705 guix graph -t module guile | xdot -
10709 All the types above correspond to @emph{build-time dependencies}. The
10710 following graph type represents the @emph{run-time dependencies}:
10714 This is the graph of @dfn{references} of a package output, as returned
10715 by @command{guix gc --references} (@pxref{Invoking guix gc}).
10717 If the given package output is not available in the store, @command{guix
10718 graph} attempts to obtain dependency information from substitutes.
10720 Here you can also pass a store file name instead of a package name. For
10721 example, the command below produces the reference graph of your profile
10722 (which can be big!):
10725 guix graph -t references `readlink -f ~/.guix-profile`
10729 This is the graph of the @dfn{referrers} of a store item, as returned by
10730 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
10732 This relies exclusively on local information from your store. For
10733 instance, let us suppose that the current Inkscape is available in 10
10734 profiles on your machine; @command{guix graph -t referrers inkscape}
10735 will show a graph rooted at Inkscape and with those 10 profiles linked
10738 It can help determine what is preventing a store item from being garbage
10743 @cindex shortest path, between packages
10744 Often, the graph of the package you are interested in does not fit on
10745 your screen, and anyway all you want to know is @emph{why} that package
10746 actually depends on some seemingly unrelated package. The
10747 @option{--path} option instructs @command{guix graph} to display the
10748 shortest path between two packages (or derivations, or store items,
10752 $ guix graph --path emacs libunistring
10755 libunistring@@0.9.10
10756 $ guix graph --path -t derivation emacs libunistring
10757 /gnu/store/@dots{}-emacs-26.3.drv
10758 /gnu/store/@dots{}-mailutils-3.9.drv
10759 /gnu/store/@dots{}-libunistring-0.9.10.drv
10760 $ guix graph --path -t references emacs libunistring
10761 /gnu/store/@dots{}-emacs-26.3
10762 /gnu/store/@dots{}-libidn2-2.2.0
10763 /gnu/store/@dots{}-libunistring-0.9.10
10766 The available options are the following:
10769 @item --type=@var{type}
10770 @itemx -t @var{type}
10771 Produce a graph output of @var{type}, where @var{type} must be one of
10772 the values listed above.
10775 List the supported graph types.
10777 @item --backend=@var{backend}
10778 @itemx -b @var{backend}
10779 Produce a graph using the selected @var{backend}.
10781 @item --list-backends
10782 List the supported graph backends.
10784 Currently, the available backends are Graphviz and d3.js.
10787 Display the shortest path between two nodes of the type specified by
10788 @option{--type}. The example below shows the shortest path between
10789 @code{libreoffice} and @code{llvm} according to the references of
10790 @code{libreoffice}:
10793 $ guix graph --path -t references libreoffice llvm
10794 /gnu/store/@dots{}-libreoffice-6.4.2.2
10795 /gnu/store/@dots{}-libepoxy-1.5.4
10796 /gnu/store/@dots{}-mesa-19.3.4
10797 /gnu/store/@dots{}-llvm-9.0.1
10800 @item --expression=@var{expr}
10801 @itemx -e @var{expr}
10802 Consider the package @var{expr} evaluates to.
10804 This is useful to precisely refer to a package, as in this example:
10807 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
10810 @item --system=@var{system}
10811 @itemx -s @var{system}
10812 Display the graph for @var{system}---e.g., @code{i686-linux}.
10814 The package dependency graph is largely architecture-independent, but there
10815 are some architecture-dependent bits that this option allows you to visualize.
10817 @item --load-path=@var{directory}
10818 @itemx -L @var{directory}
10819 Add @var{directory} to the front of the package module search path
10820 (@pxref{Package Modules}).
10822 This allows users to define their own packages and make them visible to
10823 the command-line tools.
10826 On top of that, @command{guix graph} supports all the usual package
10827 transformation options (@pxref{Package Transformation Options}). This
10828 makes it easy to view the effect of a graph-rewriting transformation
10829 such as @option{--with-input}. For example, the command below outputs
10830 the graph of @code{git} once @code{openssl} has been replaced by
10831 @code{libressl} everywhere in the graph:
10834 guix graph git --with-input=openssl=libressl
10837 So many possibilities, so much fun!
10839 @node Invoking guix publish
10840 @section Invoking @command{guix publish}
10842 @cindex @command{guix publish}
10843 The purpose of @command{guix publish} is to enable users to easily share
10844 their store with others, who can then use it as a substitute server
10845 (@pxref{Substitutes}).
10847 When @command{guix publish} runs, it spawns an HTTP server which allows
10848 anyone with network access to obtain substitutes from it. This means
10849 that any machine running Guix can also act as if it were a build farm,
10850 since the HTTP interface is compatible with Cuirass, the software behind
10851 the @code{@value{SUBSTITUTE-SERVER}} build farm.
10853 For security, each substitute is signed, allowing recipients to check
10854 their authenticity and integrity (@pxref{Substitutes}). Because
10855 @command{guix publish} uses the signing key of the system, which is only
10856 readable by the system administrator, it must be started as root; the
10857 @option{--user} option makes it drop root privileges early on.
10859 The signing key pair must be generated before @command{guix publish} is
10860 launched, using @command{guix archive --generate-key} (@pxref{Invoking
10863 The general syntax is:
10866 guix publish @var{options}@dots{}
10869 Running @command{guix publish} without any additional arguments will
10870 spawn an HTTP server on port 8080:
10876 Once a publishing server has been authorized (@pxref{Invoking guix
10877 archive}), the daemon may download substitutes from it:
10880 guix-daemon --substitute-urls=http://example.org:8080
10883 By default, @command{guix publish} compresses archives on the fly as it
10884 serves them. This ``on-the-fly'' mode is convenient in that it requires
10885 no setup and is immediately available. However, when serving lots of
10886 clients, we recommend using the @option{--cache} option, which enables
10887 caching of the archives before they are sent to clients---see below for
10888 details. The @command{guix weather} command provides a handy way to
10889 check what a server provides (@pxref{Invoking guix weather}).
10891 As a bonus, @command{guix publish} also serves as a content-addressed
10892 mirror for source files referenced in @code{origin} records
10893 (@pxref{origin Reference}). For instance, assuming @command{guix
10894 publish} is running on @code{example.org}, the following URL returns the
10895 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
10896 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
10899 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
10902 Obviously, these URLs only work for files that are in the store; in
10903 other cases, they return 404 (``Not Found'').
10905 @cindex build logs, publication
10906 Build logs are available from @code{/log} URLs like:
10909 http://example.org/log/gwspk@dots{}-guile-2.2.3
10913 When @command{guix-daemon} is configured to save compressed build logs,
10914 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
10915 URLs return the compressed log as-is, with an appropriate
10916 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
10917 running @command{guix-daemon} with @option{--log-compression=gzip} since
10918 Web browsers can automatically decompress it, which is not the case with
10921 The following options are available:
10924 @item --port=@var{port}
10925 @itemx -p @var{port}
10926 Listen for HTTP requests on @var{port}.
10928 @item --listen=@var{host}
10929 Listen on the network interface for @var{host}. The default is to
10930 accept connections from any interface.
10932 @item --user=@var{user}
10933 @itemx -u @var{user}
10934 Change privileges to @var{user} as soon as possible---i.e., once the
10935 server socket is open and the signing key has been read.
10937 @item --compression[=@var{method}[:@var{level}]]
10938 @itemx -C [@var{method}[:@var{level}]]
10939 Compress data using the given @var{method} and @var{level}. @var{method} is
10940 one of @code{lzip} and @code{gzip}; when @var{method} is omitted, @code{gzip}
10943 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
10944 to different compression levels: 1 is the fastest, and 9 is the best
10945 (CPU-intensive). The default is 3.
10947 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a small
10948 increase in CPU usage; see
10949 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip Web
10952 Unless @option{--cache} is used, compression occurs on the fly and
10953 the compressed streams are not
10954 cached. Thus, to reduce load on the machine that runs @command{guix
10955 publish}, it may be a good idea to choose a low compression level, to
10956 run @command{guix publish} behind a caching proxy, or to use
10957 @option{--cache}. Using @option{--cache} has the advantage that it
10958 allows @command{guix publish} to add @code{Content-Length} HTTP header
10961 This option can be repeated, in which case every substitute gets compressed
10962 using all the selected methods, and all of them are advertised. This is
10963 useful when users may not support all the compression methods: they can select
10964 the one they support.
10966 @item --cache=@var{directory}
10967 @itemx -c @var{directory}
10968 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
10969 and only serve archives that are in cache.
10971 When this option is omitted, archives and meta-data are created
10972 on-the-fly. This can reduce the available bandwidth, especially when
10973 compression is enabled, since this may become CPU-bound. Another
10974 drawback of the default mode is that the length of archives is not known
10975 in advance, so @command{guix publish} does not add a
10976 @code{Content-Length} HTTP header to its responses, which in turn
10977 prevents clients from knowing the amount of data being downloaded.
10979 Conversely, when @option{--cache} is used, the first request for a store
10980 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
10981 background process to @dfn{bake} the archive---computing its
10982 @code{.narinfo} and compressing the archive, if needed. Once the
10983 archive is cached in @var{directory}, subsequent requests succeed and
10984 are served directly from the cache, which guarantees that clients get
10985 the best possible bandwidth.
10987 The ``baking'' process is performed by worker threads. By default, one
10988 thread per CPU core is created, but this can be customized. See
10989 @option{--workers} below.
10991 When @option{--ttl} is used, cached entries are automatically deleted
10992 when they have expired.
10994 @item --workers=@var{N}
10995 When @option{--cache} is used, request the allocation of @var{N} worker
10996 threads to ``bake'' archives.
10998 @item --ttl=@var{ttl}
10999 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
11000 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
11001 days, @code{1m} means 1 month, and so on.
11003 This allows the user's Guix to keep substitute information in cache for
11004 @var{ttl}. However, note that @code{guix publish} does not itself
11005 guarantee that the store items it provides will indeed remain available
11006 for as long as @var{ttl}.
11008 Additionally, when @option{--cache} is used, cached entries that have
11009 not been accessed for @var{ttl} and that no longer have a corresponding
11010 item in the store, may be deleted.
11012 @item --nar-path=@var{path}
11013 Use @var{path} as the prefix for the URLs of ``nar'' files
11014 (@pxref{Invoking guix archive, normalized archives}).
11016 By default, nars are served at a URL such as
11017 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
11018 change the @code{/nar} part to @var{path}.
11020 @item --public-key=@var{file}
11021 @itemx --private-key=@var{file}
11022 Use the specific @var{file}s as the public/private key pair used to sign
11023 the store items being published.
11025 The files must correspond to the same key pair (the private key is used
11026 for signing and the public key is merely advertised in the signature
11027 metadata). They must contain keys in the canonical s-expression format
11028 as produced by @command{guix archive --generate-key} (@pxref{Invoking
11029 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
11030 @file{/etc/guix/signing-key.sec} are used.
11032 @item --repl[=@var{port}]
11033 @itemx -r [@var{port}]
11034 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
11035 Reference Manual}) on @var{port} (37146 by default). This is used
11036 primarily for debugging a running @command{guix publish} server.
11039 Enabling @command{guix publish} on Guix System is a one-liner: just
11040 instantiate a @code{guix-publish-service-type} service in the @code{services} field
11041 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
11042 @code{guix-publish-service-type}}).
11044 If you are instead running Guix on a ``foreign distro'', follow these
11049 If your host distro uses the systemd init system:
11052 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
11053 /etc/systemd/system/
11054 # systemctl start guix-publish && systemctl enable guix-publish
11058 If your host distro uses the Upstart init system:
11061 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
11062 # start guix-publish
11066 Otherwise, proceed similarly with your distro's init system.
11069 @node Invoking guix challenge
11070 @section Invoking @command{guix challenge}
11072 @cindex reproducible builds
11073 @cindex verifiable builds
11074 @cindex @command{guix challenge}
11076 Do the binaries provided by this server really correspond to the source
11077 code it claims to build? Is a package build process deterministic?
11078 These are the questions the @command{guix challenge} command attempts to
11081 The former is obviously an important question: Before using a substitute
11082 server (@pxref{Substitutes}), one had better @emph{verify} that it
11083 provides the right binaries, and thus @emph{challenge} it. The latter
11084 is what enables the former: If package builds are deterministic, then
11085 independent builds of the package should yield the exact same result,
11086 bit for bit; if a server provides a binary different from the one
11087 obtained locally, it may be either corrupt or malicious.
11089 We know that the hash that shows up in @file{/gnu/store} file names is
11090 the hash of all the inputs of the process that built the file or
11091 directory---compilers, libraries, build scripts,
11092 etc. (@pxref{Introduction}). Assuming deterministic build processes,
11093 one store file name should map to exactly one build output.
11094 @command{guix challenge} checks whether there is, indeed, a single
11095 mapping by comparing the build outputs of several independent builds of
11096 any given store item.
11098 The command output looks like this:
11101 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
11102 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
11103 updating list of substitutes from 'https://guix.example.org'... 100.0%
11104 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
11105 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
11106 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
11107 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
11109 /lib/libcrypto.so.1.1
11112 /gnu/store/@dots{}-git-2.5.0 contents differ:
11113 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
11114 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
11115 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
11117 /libexec/git-core/git-fsck
11119 /gnu/store/@dots{}-pius-2.1.1 contents differ:
11120 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
11121 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
11122 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
11124 /share/man/man1/pius.1.gz
11128 6,406 store items were analyzed:
11129 - 4,749 (74.1%) were identical
11130 - 525 (8.2%) differed
11131 - 1,132 (17.7%) were inconclusive
11135 In this example, @command{guix challenge} first scans the store to
11136 determine the set of locally-built derivations---as opposed to store
11137 items that were downloaded from a substitute server---and then queries
11138 all the substitute servers. It then reports those store items for which
11139 the servers obtained a result different from the local build.
11141 @cindex non-determinism, in package builds
11142 As an example, @code{guix.example.org} always gets a different answer.
11143 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
11144 case of Git. This might indicate that the build process of Git is
11145 non-deterministic, meaning that its output varies as a function of
11146 various things that Guix does not fully control, in spite of building
11147 packages in isolated environments (@pxref{Features}). Most common
11148 sources of non-determinism include the addition of timestamps in build
11149 results, the inclusion of random numbers, and directory listings sorted
11150 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
11153 To find out what is wrong with this Git binary, the easiest approach is
11157 guix challenge git \
11158 --diff=diffoscope \
11159 --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
11162 This automatically invokes @command{diffoscope}, which displays detailed
11163 information about files that differ.
11165 Alternatively, we can do something along these lines (@pxref{Invoking guix
11169 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-git-2.5.0 \
11170 | lzip -d | guix archive -x /tmp/git
11171 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
11174 This command shows the difference between the files resulting from the
11175 local build, and the files resulting from the build on
11176 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
11177 diffutils, Comparing and Merging Files}). The @command{diff} command
11178 works great for text files. When binary files differ, a better option
11179 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
11180 visualize differences for all kinds of files.
11182 Once you have done that work, you can tell whether the differences are due
11183 to a non-deterministic build process or to a malicious server. We try
11184 hard to remove sources of non-determinism in packages to make it easier
11185 to verify substitutes, but of course, this is a process that
11186 involves not just Guix, but a large part of the free software community.
11187 In the meantime, @command{guix challenge} is one tool to help address
11190 If you are writing packages for Guix, you are encouraged to check
11191 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
11192 same build result as you did with:
11195 $ guix challenge @var{package}
11199 where @var{package} is a package specification such as
11200 @code{guile@@2.0} or @code{glibc:debug}.
11202 The general syntax is:
11205 guix challenge @var{options} [@var{packages}@dots{}]
11208 When a difference is found between the hash of a locally-built item and
11209 that of a server-provided substitute, or among substitutes provided by
11210 different servers, the command displays it as in the example above and
11211 its exit code is 2 (other non-zero exit codes denote other kinds of
11214 The one option that matters is:
11218 @item --substitute-urls=@var{urls}
11219 Consider @var{urls} the whitespace-separated list of substitute source
11220 URLs to compare to.
11222 @item --diff=@var{mode}
11223 Upon mismatches, show differences according to @var{mode}, one of:
11226 @item @code{simple} (the default)
11227 Show the list of files that differ.
11229 @item @code{diffoscope}
11230 @itemx @var{command}
11231 Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
11232 two directories whose contents do not match.
11234 When @var{command} is an absolute file name, run @var{command} instead
11238 Do not show further details about the differences.
11241 Thus, unless @option{--diff=none} is passed, @command{guix challenge}
11242 downloads the store items from the given substitute servers so that it
11247 Show details about matches (identical contents) in addition to
11248 information about mismatches.
11252 @node Invoking guix copy
11253 @section Invoking @command{guix copy}
11255 @cindex copy, of store items, over SSH
11256 @cindex SSH, copy of store items
11257 @cindex sharing store items across machines
11258 @cindex transferring store items across machines
11259 The @command{guix copy} command copies items from the store of one
11260 machine to that of another machine over a secure shell (SSH)
11261 connection@footnote{This command is available only when Guile-SSH was
11262 found. @xref{Requirements}, for details.}. For example, the following
11263 command copies the @code{coreutils} package, the user's profile, and all
11264 their dependencies over to @var{host}, logged in as @var{user}:
11267 guix copy --to=@var{user}@@@var{host} \
11268 coreutils `readlink -f ~/.guix-profile`
11271 If some of the items to be copied are already present on @var{host},
11272 they are not actually sent.
11274 The command below retrieves @code{libreoffice} and @code{gimp} from
11275 @var{host}, assuming they are available there:
11278 guix copy --from=@var{host} libreoffice gimp
11281 The SSH connection is established using the Guile-SSH client, which is
11282 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
11283 @file{~/.ssh/config}, and uses the SSH agent for authentication.
11285 The key used to sign items that are sent must be accepted by the remote
11286 machine. Likewise, the key used by the remote machine to sign items you
11287 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
11288 own daemon. @xref{Invoking guix archive}, for more information about
11289 store item authentication.
11291 The general syntax is:
11294 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
11297 You must always specify one of the following options:
11300 @item --to=@var{spec}
11301 @itemx --from=@var{spec}
11302 Specify the host to send to or receive from. @var{spec} must be an SSH
11303 spec such as @code{example.org}, @code{charlie@@example.org}, or
11304 @code{charlie@@example.org:2222}.
11307 The @var{items} can be either package names, such as @code{gimp}, or
11308 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
11310 When specifying the name of a package to send, it is first built if
11311 needed, unless @option{--dry-run} was specified. Common build options
11312 are supported (@pxref{Common Build Options}).
11315 @node Invoking guix container
11316 @section Invoking @command{guix container}
11318 @cindex @command{guix container}
11320 As of version @value{VERSION}, this tool is experimental. The interface
11321 is subject to radical change in the future.
11324 The purpose of @command{guix container} is to manipulate processes
11325 running within an isolated environment, commonly known as a
11326 ``container'', typically created by the @command{guix environment}
11327 (@pxref{Invoking guix environment}) and @command{guix system container}
11328 (@pxref{Invoking guix system}) commands.
11330 The general syntax is:
11333 guix container @var{action} @var{options}@dots{}
11336 @var{action} specifies the operation to perform with a container, and
11337 @var{options} specifies the context-specific arguments for the action.
11339 The following actions are available:
11343 Execute a command within the context of a running container.
11348 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
11351 @var{pid} specifies the process ID of the running container.
11352 @var{program} specifies an executable file name within the root file
11353 system of the container. @var{arguments} are the additional options that
11354 will be passed to @var{program}.
11356 The following command launches an interactive login shell inside a
11357 Guix system container, started by @command{guix system container}, and whose
11358 process ID is 9001:
11361 guix container exec 9001 /run/current-system/profile/bin/bash --login
11364 Note that the @var{pid} cannot be the parent process of a container. It
11365 must be PID 1 of the container or one of its child processes.
11369 @node Invoking guix weather
11370 @section Invoking @command{guix weather}
11372 Occasionally you're grumpy because substitutes are lacking and you end
11373 up building packages by yourself (@pxref{Substitutes}). The
11374 @command{guix weather} command reports on substitute availability on the
11375 specified servers so you can have an idea of whether you'll be grumpy
11376 today. It can sometimes be useful info as a user, but it is primarily
11377 useful to people running @command{guix publish} (@pxref{Invoking guix
11380 @cindex statistics, for substitutes
11381 @cindex availability of substitutes
11382 @cindex substitute availability
11383 @cindex weather, substitute availability
11384 Here's a sample run:
11387 $ guix weather --substitute-urls=https://guix.example.org
11388 computing 5,872 package derivations for x86_64-linux...
11389 looking for 6,128 store items on https://guix.example.org..
11390 updating list of substitutes from 'https://guix.example.org'... 100.0%
11391 https://guix.example.org
11392 43.4% substitutes available (2,658 out of 6,128)
11393 7,032.5 MiB of nars (compressed)
11394 19,824.2 MiB on disk (uncompressed)
11395 0.030 seconds per request (182.9 seconds in total)
11396 33.5 requests per second
11398 9.8% (342 out of 3,470) of the missing items are queued
11400 x86_64-linux: 518 (59.7%)
11401 i686-linux: 221 (25.5%)
11402 aarch64-linux: 128 (14.8%)
11403 build rate: 23.41 builds per hour
11404 x86_64-linux: 11.16 builds per hour
11405 i686-linux: 6.03 builds per hour
11406 aarch64-linux: 6.41 builds per hour
11409 @cindex continuous integration, statistics
11410 As you can see, it reports the fraction of all the packages for which
11411 substitutes are available on the server---regardless of whether
11412 substitutes are enabled, and regardless of whether this server's signing
11413 key is authorized. It also reports the size of the compressed archives
11414 (``nars'') provided by the server, the size the corresponding store
11415 items occupy in the store (assuming deduplication is turned off), and
11416 the server's throughput. The second part gives continuous integration
11417 (CI) statistics, if the server supports it. In addition, using the
11418 @option{--coverage} option, @command{guix weather} can list ``important''
11419 package substitutes missing on the server (see below).
11421 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
11422 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
11423 challenge}, it ignores signatures on those substitutes, which is
11424 innocuous since the command only gathers statistics and cannot install
11427 The general syntax is:
11430 guix weather @var{options}@dots{} [@var{packages}@dots{}]
11433 When @var{packages} is omitted, @command{guix weather} checks the availability
11434 of substitutes for @emph{all} the packages, or for those specified with
11435 @option{--manifest}; otherwise it only considers the specified packages. It
11436 is also possible to query specific system types with @option{--system}.
11437 @command{guix weather} exits with a non-zero code when the fraction of
11438 available substitutes is below 100%.
11440 The available options are listed below.
11443 @item --substitute-urls=@var{urls}
11444 @var{urls} is the space-separated list of substitute server URLs to
11445 query. When this option is omitted, the default set of substitute
11446 servers is queried.
11448 @item --system=@var{system}
11449 @itemx -s @var{system}
11450 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
11451 option can be repeated, in which case @command{guix weather} will query
11452 substitutes for several system types.
11454 @item --manifest=@var{file}
11455 Instead of querying substitutes for all the packages, only ask for those
11456 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
11457 with the @code{-m} option of @command{guix package} (@pxref{Invoking
11460 This option can be repeated several times, in which case the manifests
11463 @item --coverage[=@var{count}]
11464 @itemx -c [@var{count}]
11465 Report on substitute coverage for packages: list packages with at least
11466 @var{count} dependents (zero by default) for which substitutes are
11467 unavailable. Dependent packages themselves are not listed: if @var{b} depends
11468 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
11469 @var{b} usually lacks substitutes as well. The result looks like this:
11472 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
11473 computing 8,983 package derivations for x86_64-linux...
11474 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
11475 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
11476 @value{SUBSTITUTE-URL}
11477 64.7% substitutes available (6,047 out of 9,343)
11479 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
11480 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
11481 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
11482 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
11486 What this example shows is that @code{kcoreaddons} and presumably the 58
11487 packages that depend on it have no substitutes at @code{ci.guix.info};
11488 likewise for @code{qgpgme} and the 46 packages that depend on it.
11490 If you are a Guix developer, or if you are taking care of this build farm,
11491 you'll probably want to have a closer look at these packages: they may simply
11494 @item --display-missing
11495 Display the list of store items for which substitutes are missing.
11498 @node Invoking guix processes
11499 @section Invoking @command{guix processes}
11501 The @command{guix processes} command can be useful to developers and system
11502 administrators, especially on multi-user machines and on build farms: it lists
11503 the current sessions (connections to the daemon), as well as information about
11504 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
11505 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
11506 listed.}. Here's an example of the information it returns:
11509 $ sudo guix processes
11512 ClientCommand: guix environment --ad-hoc python
11516 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
11520 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
11521 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
11522 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
11523 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
11524 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
11525 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
11526 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
11529 In this example we see that @command{guix-daemon} has three clients:
11530 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
11531 integration tool; their process identifier (PID) is given by the
11532 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
11533 @command{guix-daemon} sub-process of this particular session.
11535 The @code{LockHeld} fields show which store items are currently locked by this
11536 session, which corresponds to store items being built or substituted (the
11537 @code{LockHeld} field is not displayed when @command{guix processes} is not
11538 running as root). Last, by looking at the @code{ChildProcess} field, we
11539 understand that these three builds are being offloaded (@pxref{Daemon Offload
11542 The output is in Recutils format so we can use the handy @command{recsel}
11543 command to select sessions of interest (@pxref{Selection Expressions,,,
11544 recutils, GNU recutils manual}). As an example, the command shows the command
11545 line and PID of the client that triggered the build of a Perl package:
11548 $ sudo guix processes | \
11549 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
11551 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
11554 @node System Configuration
11555 @chapter System Configuration
11557 @cindex system configuration
11558 Guix System supports a consistent whole-system configuration
11559 mechanism. By that we mean that all aspects of the global system
11560 configuration---such as the available system services, timezone and
11561 locale settings, user accounts---are declared in a single place. Such
11562 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
11564 One of the advantages of putting all the system configuration under the
11565 control of Guix is that it supports transactional system upgrades, and
11566 makes it possible to roll back to a previous system instantiation,
11567 should something go wrong with the new one (@pxref{Features}). Another
11568 advantage is that it makes it easy to replicate the exact same configuration
11569 across different machines, or at different points in time, without
11570 having to resort to additional administration tools layered on top of
11571 the own tools of the system.
11572 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
11574 This section describes this mechanism. First we focus on the system
11575 administrator's viewpoint---explaining how the system is configured and
11576 instantiated. Then we show how this mechanism can be extended, for
11577 instance to support new system services.
11580 * Using the Configuration System:: Customizing your GNU system.
11581 * operating-system Reference:: Detail of operating-system declarations.
11582 * File Systems:: Configuring file system mounts.
11583 * Mapped Devices:: Block device extra processing.
11584 * User Accounts:: Specifying user accounts.
11585 * Keyboard Layout:: How the system interprets key strokes.
11586 * Locales:: Language and cultural convention settings.
11587 * Services:: Specifying system services.
11588 * Setuid Programs:: Programs running with root privileges.
11589 * X.509 Certificates:: Authenticating HTTPS servers.
11590 * Name Service Switch:: Configuring libc's name service switch.
11591 * Initial RAM Disk:: Linux-Libre bootstrapping.
11592 * Bootloader Configuration:: Configuring the boot loader.
11593 * Invoking guix system:: Instantiating a system configuration.
11594 * Invoking guix deploy:: Deploying a system configuration to a remote host.
11595 * Running Guix in a VM:: How to run Guix System in a virtual machine.
11596 * Defining Services:: Adding new service definitions.
11599 @node Using the Configuration System
11600 @section Using the Configuration System
11602 The operating system is configured by providing an
11603 @code{operating-system} declaration in a file that can then be passed to
11604 the @command{guix system} command (@pxref{Invoking guix system}). A
11605 simple setup, with the default system services, the default Linux-Libre
11606 kernel, initial RAM disk, and boot loader looks like this:
11608 @findex operating-system
11610 @include os-config-bare-bones.texi
11613 This example should be self-describing. Some of the fields defined
11614 above, such as @code{host-name} and @code{bootloader}, are mandatory.
11615 Others, such as @code{packages} and @code{services}, can be omitted, in
11616 which case they get a default value.
11618 Below we discuss the effect of some of the most important fields
11619 (@pxref{operating-system Reference}, for details about all the available
11620 fields), and how to @dfn{instantiate} the operating system using
11621 @command{guix system}.
11623 @unnumberedsubsec Bootloader
11625 @cindex legacy boot, on Intel machines
11626 @cindex BIOS boot, on Intel machines
11629 The @code{bootloader} field describes the method that will be used to boot
11630 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
11631 mode, as in the example above. However, more recent machines rely instead on
11632 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
11633 the @code{bootloader} field should contain something along these lines:
11636 (bootloader-configuration
11637 (bootloader grub-efi-bootloader)
11638 (target "/boot/efi"))
11641 @xref{Bootloader Configuration}, for more information on the available
11642 configuration options.
11644 @unnumberedsubsec Globally-Visible Packages
11646 @vindex %base-packages
11647 The @code{packages} field lists packages that will be globally visible
11648 on the system, for all user accounts---i.e., in every user's @env{PATH}
11649 environment variable---in addition to the per-user profiles
11650 (@pxref{Invoking guix package}). The @code{%base-packages} variable
11651 provides all the tools one would expect for basic user and administrator
11652 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
11653 the GNU Zile lightweight text editor, @command{find}, @command{grep},
11654 etc. The example above adds GNU@tie{}Screen to those,
11655 taken from the @code{(gnu packages screen)}
11656 module (@pxref{Package Modules}). The
11657 @code{(list package output)} syntax can be used to add a specific output
11661 (use-modules (gnu packages))
11662 (use-modules (gnu packages dns))
11666 (packages (cons (list bind "utils")
11670 @findex specification->package
11671 Referring to packages by variable name, like @code{bind} above, has
11672 the advantage of being unambiguous; it also allows typos and such to be
11673 diagnosed right away as ``unbound variables''. The downside is that one
11674 needs to know which module defines which package, and to augment the
11675 @code{use-package-modules} line accordingly. To avoid that, one can use
11676 the @code{specification->package} procedure of the @code{(gnu packages)}
11677 module, which returns the best package for a given name or name and
11681 (use-modules (gnu packages))
11685 (packages (append (map specification->package
11686 '("tcpdump" "htop" "gnupg@@2.0"))
11690 @unnumberedsubsec System Services
11693 @vindex %base-services
11694 The @code{services} field lists @dfn{system services} to be made
11695 available when the system starts (@pxref{Services}).
11696 The @code{operating-system} declaration above specifies that, in
11697 addition to the basic services, we want the OpenSSH secure shell
11698 daemon listening on port 2222 (@pxref{Networking Services,
11699 @code{openssh-service-type}}). Under the hood,
11700 @code{openssh-service-type} arranges so that @command{sshd} is started with the
11701 right command-line options, possibly with supporting configuration files
11702 generated as needed (@pxref{Defining Services}).
11704 @cindex customization, of services
11705 @findex modify-services
11706 Occasionally, instead of using the base services as is, you will want to
11707 customize them. To do this, use @code{modify-services} (@pxref{Service
11708 Reference, @code{modify-services}}) to modify the list.
11710 For example, suppose you want to modify @code{guix-daemon} and Mingetty
11711 (the console log-in) in the @code{%base-services} list (@pxref{Base
11712 Services, @code{%base-services}}). To do that, you can write the
11713 following in your operating system declaration:
11716 (define %my-services
11717 ;; My very own list of services.
11718 (modify-services %base-services
11719 (guix-service-type config =>
11720 (guix-configuration
11722 (use-substitutes? #f)
11723 (extra-options '("--gc-keep-derivations"))))
11724 (mingetty-service-type config =>
11725 (mingetty-configuration
11726 (inherit config)))))
11730 (services %my-services))
11733 This changes the configuration---i.e., the service parameters---of the
11734 @code{guix-service-type} instance, and that of all the
11735 @code{mingetty-service-type} instances in the @code{%base-services} list.
11736 Observe how this is accomplished: first, we arrange for the original
11737 configuration to be bound to the identifier @code{config} in the
11738 @var{body}, and then we write the @var{body} so that it evaluates to the
11739 desired configuration. In particular, notice how we use @code{inherit}
11740 to create a new configuration which has the same values as the old
11741 configuration, but with a few modifications.
11743 @cindex encrypted disk
11744 The configuration for a typical ``desktop'' usage, with an encrypted
11745 root partition, the X11 display
11746 server, GNOME and Xfce (users can choose which of these desktop
11747 environments to use at the log-in screen by pressing @kbd{F1}), network
11748 management, power management, and more, would look like this:
11751 @include os-config-desktop.texi
11754 A graphical system with a choice of lightweight window managers
11755 instead of full-blown desktop environments would look like this:
11758 @include os-config-lightweight-desktop.texi
11761 This example refers to the @file{/boot/efi} file system by its UUID,
11762 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
11763 as returned by the @command{blkid} command.
11765 @xref{Desktop Services}, for the exact list of services provided by
11766 @code{%desktop-services}. @xref{X.509 Certificates}, for background
11767 information about the @code{nss-certs} package that is used here.
11769 Again, @code{%desktop-services} is just a list of service objects. If
11770 you want to remove services from there, you can do so using the
11771 procedures for list filtering (@pxref{SRFI-1 Filtering and
11772 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
11773 following expression returns a list that contains all the services in
11774 @code{%desktop-services} minus the Avahi service:
11777 (remove (lambda (service)
11778 (eq? (service-kind service) avahi-service-type))
11782 @unnumberedsubsec Instantiating the System
11784 Assuming the @code{operating-system} declaration
11785 is stored in the @file{my-system-config.scm}
11786 file, the @command{guix system reconfigure my-system-config.scm} command
11787 instantiates that configuration, and makes it the default GRUB boot
11788 entry (@pxref{Invoking guix system}).
11790 The normal way to change the system configuration is by updating this
11791 file and re-running @command{guix system reconfigure}. One should never
11792 have to touch files in @file{/etc} or to run commands that modify the
11793 system state such as @command{useradd} or @command{grub-install}. In
11794 fact, you must avoid that since that would not only void your warranty
11795 but also prevent you from rolling back to previous versions of your
11796 system, should you ever need to.
11798 @cindex roll-back, of the operating system
11799 Speaking of roll-back, each time you run @command{guix system
11800 reconfigure}, a new @dfn{generation} of the system is created---without
11801 modifying or deleting previous generations. Old system generations get
11802 an entry in the bootloader boot menu, allowing you to boot them in case
11803 something went wrong with the latest generation. Reassuring, no? The
11804 @command{guix system list-generations} command lists the system
11805 generations available on disk. It is also possible to roll back the
11806 system via the commands @command{guix system roll-back} and
11807 @command{guix system switch-generation}.
11809 Although the @command{guix system reconfigure} command will not modify
11810 previous generations, you must take care when the current generation is not
11811 the latest (e.g., after invoking @command{guix system roll-back}), since
11812 the operation might overwrite a later generation (@pxref{Invoking guix
11815 @unnumberedsubsec The Programming Interface
11817 At the Scheme level, the bulk of an @code{operating-system} declaration
11818 is instantiated with the following monadic procedure (@pxref{The Store
11821 @deffn {Monadic Procedure} operating-system-derivation os
11822 Return a derivation that builds @var{os}, an @code{operating-system}
11823 object (@pxref{Derivations}).
11825 The output of the derivation is a single directory that refers to all
11826 the packages, configuration files, and other supporting files needed to
11827 instantiate @var{os}.
11830 This procedure is provided by the @code{(gnu system)} module. Along
11831 with @code{(gnu services)} (@pxref{Services}), this module contains the
11832 guts of Guix System. Make sure to visit it!
11835 @node operating-system Reference
11836 @section @code{operating-system} Reference
11838 This section summarizes all the options available in
11839 @code{operating-system} declarations (@pxref{Using the Configuration
11842 @deftp {Data Type} operating-system
11843 This is the data type representing an operating system configuration.
11844 By that, we mean all the global system configuration, not per-user
11845 configuration (@pxref{Using the Configuration System}).
11848 @item @code{kernel} (default: @code{linux-libre})
11849 The package object of the operating system kernel to
11850 use@footnote{Currently only the Linux-libre kernel is fully supported.
11851 Using GNU@tie{}mach with the GNU@tie{}Hurd is experimental and only
11852 available when building a virtual machine disk image.}.
11855 @item @code{hurd} (default: @code{#f})
11856 The package object of the hurd to be started by the kernel. When this
11857 field is set, produce a GNU/Hurd operating system. In that case,
11858 @code{kernel} must also be set to the @code{gnumach} package---the
11859 microkernel the Hurd runs on.
11862 This feature is experimental and only supported for disk images.
11865 @item @code{kernel-loadable-modules} (default: '())
11866 A list of objects (usually packages) to collect loadable kernel modules
11867 from--e.g. @code{(list ddcci-driver-linux)}.
11869 @item @code{kernel-arguments} (default: @code{%default-kernel-arguments})
11870 List of strings or gexps representing additional arguments to pass on
11871 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
11873 @item @code{bootloader}
11874 The system bootloader configuration object. @xref{Bootloader Configuration}.
11877 This is the label (a string) as it appears in the bootloader's menu entry.
11878 The default label includes the kernel name and version.
11880 @item @code{keyboard-layout} (default: @code{#f})
11881 This field specifies the keyboard layout to use in the console. It can be
11882 either @code{#f}, in which case the default keyboard layout is used (usually
11883 US English), or a @code{<keyboard-layout>} record.
11885 This keyboard layout is in effect as soon as the kernel has booted. For
11886 instance, it is the keyboard layout in effect when you type a passphrase if
11887 your root file system is on a @code{luks-device-mapping} mapped device
11888 (@pxref{Mapped Devices}).
11891 This does @emph{not} specify the keyboard layout used by the bootloader, nor
11892 that used by the graphical display server. @xref{Bootloader Configuration},
11893 for information on how to specify the bootloader's keyboard layout. @xref{X
11894 Window}, for information on how to specify the keyboard layout used by the X
11898 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
11900 @cindex initial RAM disk
11901 The list of Linux kernel modules that need to be available in the
11902 initial RAM disk. @xref{Initial RAM Disk}.
11904 @item @code{initrd} (default: @code{base-initrd})
11905 A procedure that returns an initial RAM disk for the Linux
11906 kernel. This field is provided to support low-level customization and
11907 should rarely be needed for casual use. @xref{Initial RAM Disk}.
11909 @item @code{firmware} (default: @code{%base-firmware})
11911 List of firmware packages loadable by the operating system kernel.
11913 The default includes firmware needed for Atheros- and Broadcom-based
11914 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
11915 respectively). @xref{Hardware Considerations}, for more info on
11916 supported hardware.
11918 @item @code{host-name}
11921 @item @code{hosts-file}
11923 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
11924 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
11925 Reference Manual}). The default is a file with entries for
11926 @code{localhost} and @var{host-name}.
11928 @item @code{mapped-devices} (default: @code{'()})
11929 A list of mapped devices. @xref{Mapped Devices}.
11931 @item @code{file-systems}
11932 A list of file systems. @xref{File Systems}.
11934 @item @code{swap-devices} (default: @code{'()})
11935 @cindex swap devices
11936 A list of strings identifying devices or files to be used for ``swap
11937 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
11938 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
11939 It is possible to specify a swap file in a file system on a mapped
11940 device, provided that the necessary device mapping and file system are
11941 also specified. @xref{Mapped Devices} and @ref{File Systems}.
11943 @item @code{users} (default: @code{%base-user-accounts})
11944 @itemx @code{groups} (default: @code{%base-groups})
11945 List of user accounts and groups. @xref{User Accounts}.
11947 If the @code{users} list lacks a user account with UID@tie{}0, a
11948 ``root'' account with UID@tie{}0 is automatically added.
11950 @item @code{skeletons} (default: @code{(default-skeletons)})
11951 A list of target file name/file-like object tuples (@pxref{G-Expressions,
11952 file-like objects}). These are the skeleton files that will be added to
11953 the home directory of newly-created user accounts.
11955 For instance, a valid value may look like this:
11958 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
11959 (".guile" ,(plain-file "guile"
11960 "(use-modules (ice-9 readline))
11961 (activate-readline)")))
11964 @item @code{issue} (default: @code{%default-issue})
11965 A string denoting the contents of the @file{/etc/issue} file, which is
11966 displayed when users log in on a text console.
11968 @item @code{packages} (default: @code{%base-packages})
11969 A list of packages to be installed in the global profile, which is accessible
11970 at @file{/run/current-system/profile}. Each element is either a package
11971 variable or a package/output tuple. Here's a simple example of both:
11974 (cons* git ; the default "out" output
11975 (list git "send-email") ; another output of git
11976 %base-packages) ; the default set
11979 The default set includes core utilities and it is good practice to
11980 install non-core utilities in user profiles (@pxref{Invoking guix
11983 @item @code{timezone}
11984 A timezone identifying string---e.g., @code{"Europe/Paris"}.
11986 You can run the @command{tzselect} command to find out which timezone
11987 string corresponds to your region. Choosing an invalid timezone name
11988 causes @command{guix system} to fail.
11990 @item @code{locale} (default: @code{"en_US.utf8"})
11991 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
11992 Library Reference Manual}). @xref{Locales}, for more information.
11994 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
11995 The list of locale definitions to be compiled and that may be used at
11996 run time. @xref{Locales}.
11998 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
11999 The list of GNU@tie{}libc packages whose locale data and tools are used
12000 to build the locale definitions. @xref{Locales}, for compatibility
12001 considerations that justify this option.
12003 @item @code{name-service-switch} (default: @code{%default-nss})
12004 Configuration of the libc name service switch (NSS)---a
12005 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
12008 @item @code{services} (default: @code{%base-services})
12009 A list of service objects denoting system services. @xref{Services}.
12011 @cindex essential services
12012 @item @code{essential-services} (default: ...)
12013 The list of ``essential services''---i.e., things like instances of
12014 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
12015 Reference}), which are derived from the operating system definition itself.
12016 As a user you should @emph{never} need to touch this field.
12018 @item @code{pam-services} (default: @code{(base-pam-services)})
12020 @cindex pluggable authentication modules
12021 Linux @dfn{pluggable authentication module} (PAM) services.
12022 @c FIXME: Add xref to PAM services section.
12024 @item @code{setuid-programs} (default: @code{%setuid-programs})
12025 List of string-valued G-expressions denoting setuid programs.
12026 @xref{Setuid Programs}.
12028 @item @code{sudoers-file} (default: @code{%sudoers-specification})
12029 @cindex sudoers file
12030 The contents of the @file{/etc/sudoers} file as a file-like object
12031 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
12033 This file specifies which users can use the @command{sudo} command, what
12034 they are allowed to do, and what privileges they may gain. The default
12035 is that only @code{root} and members of the @code{wheel} group may use
12040 @deffn {Scheme Syntax} this-operating-system
12041 When used in the @emph{lexical scope} of an operating system field definition,
12042 this identifier resolves to the operating system being defined.
12044 The example below shows how to refer to the operating system being defined in
12045 the definition of the @code{label} field:
12048 (use-modules (gnu) (guix))
12052 (label (package-full-name
12053 (operating-system-kernel this-operating-system))))
12056 It is an error to refer to @code{this-operating-system} outside an operating
12063 @section File Systems
12065 The list of file systems to be mounted is specified in the
12066 @code{file-systems} field of the operating system declaration
12067 (@pxref{Using the Configuration System}). Each file system is declared
12068 using the @code{file-system} form, like this:
12072 (mount-point "/home")
12073 (device "/dev/sda3")
12077 As usual, some of the fields are mandatory---those shown in the example
12078 above---while others can be omitted. These are described below.
12080 @deftp {Data Type} file-system
12081 Objects of this type represent file systems to be mounted. They
12082 contain the following members:
12086 This is a string specifying the type of the file system---e.g.,
12089 @item @code{mount-point}
12090 This designates the place where the file system is to be mounted.
12092 @item @code{device}
12093 This names the ``source'' of the file system. It can be one of three
12094 things: a file system label, a file system UUID, or the name of a
12095 @file{/dev} node. Labels and UUIDs offer a way to refer to file
12096 systems without having to hard-code their actual device
12097 name@footnote{Note that, while it is tempting to use
12098 @file{/dev/disk/by-uuid} and similar device names to achieve the same
12099 result, this is not recommended: These special device nodes are created
12100 by the udev daemon and may be unavailable at the time the device is
12103 @findex file-system-label
12104 File system labels are created using the @code{file-system-label}
12105 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
12106 plain strings. Here's an example of a file system referred to by its
12107 label, as shown by the @command{e2label} command:
12111 (mount-point "/home")
12113 (device (file-system-label "my-home")))
12117 UUIDs are converted from their string representation (as shown by the
12118 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
12119 @code{uuid} form expects 16-byte UUIDs as defined in
12120 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
12121 form of UUID used by the ext2 family of file systems and others, but it
12122 is different from ``UUIDs'' found in FAT file systems, for instance.},
12127 (mount-point "/home")
12129 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
12132 When the source of a file system is a mapped device (@pxref{Mapped
12133 Devices}), its @code{device} field @emph{must} refer to the mapped
12134 device name---e.g., @file{"/dev/mapper/root-partition"}.
12135 This is required so that
12136 the system knows that mounting the file system depends on having the
12137 corresponding device mapping established.
12139 @item @code{flags} (default: @code{'()})
12140 This is a list of symbols denoting mount flags. Recognized flags
12141 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
12142 access to special files), @code{no-suid} (ignore setuid and setgid
12143 bits), @code{no-atime} (do not update file access times),
12144 @code{strict-atime} (update file access time), @code{lazy-time} (only
12145 update time on the in-memory version of the file inode), and
12146 @code{no-exec} (disallow program execution).
12147 @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
12148 Manual}, for more information on these flags.
12150 @item @code{options} (default: @code{#f})
12151 This is either @code{#f}, or a string denoting mount options passed to
12152 the file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C
12153 Library Reference Manual}, for details and run @command{man 8 mount} for
12154 options for various file systems. Note that the
12155 @code{file-system-options->alist} and @code{alist->file-system-options}
12156 procedures from @code{(gnu system file-systems)} can be used to convert
12157 file system options given as an association list to the string
12158 representation, and vice-versa.
12160 @item @code{mount?} (default: @code{#t})
12161 This value indicates whether to automatically mount the file system when
12162 the system is brought up. When set to @code{#f}, the file system gets
12163 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
12164 is not automatically mounted.
12166 @item @code{needed-for-boot?} (default: @code{#f})
12167 This Boolean value indicates whether the file system is needed when
12168 booting. If that is true, then the file system is mounted when the
12169 initial RAM disk (initrd) is loaded. This is always the case, for
12170 instance, for the root file system.
12172 @item @code{check?} (default: @code{#t})
12173 This Boolean indicates whether the file system needs to be checked for
12174 errors before being mounted.
12176 @item @code{create-mount-point?} (default: @code{#f})
12177 When true, the mount point is created if it does not exist yet.
12179 @item @code{mount-may-fail?} (default: @code{#f})
12180 When true, this indicates that mounting this file system can fail but
12181 that should not be considered an error. This is useful in unusual
12182 cases; an example of this is @code{efivarfs}, a file system that can
12183 only be mounted on EFI/UEFI systems.
12185 @item @code{dependencies} (default: @code{'()})
12186 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
12187 representing file systems that must be mounted or mapped devices that
12188 must be opened before (and unmounted or closed after) this one.
12190 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
12191 a dependency of @file{/sys/fs/cgroup/cpu} and
12192 @file{/sys/fs/cgroup/memory}.
12194 Another example is a file system that depends on a mapped device, for
12195 example for an encrypted partition (@pxref{Mapped Devices}).
12199 The @code{(gnu system file-systems)} exports the following useful
12202 @defvr {Scheme Variable} %base-file-systems
12203 These are essential file systems that are required on normal systems,
12204 such as @code{%pseudo-terminal-file-system} and @code{%immutable-store} (see
12205 below). Operating system declarations should always contain at least
12209 @defvr {Scheme Variable} %pseudo-terminal-file-system
12210 This is the file system to be mounted as @file{/dev/pts}. It supports
12211 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
12212 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
12213 Manual}). Pseudo-terminals are used by terminal emulators such as
12217 @defvr {Scheme Variable} %shared-memory-file-system
12218 This file system is mounted as @file{/dev/shm} and is used to support
12219 memory sharing across processes (@pxref{Memory-mapped I/O,
12220 @code{shm_open},, libc, The GNU C Library Reference Manual}).
12223 @defvr {Scheme Variable} %immutable-store
12224 This file system performs a read-only ``bind mount'' of
12225 @file{/gnu/store}, making it read-only for all the users including
12226 @code{root}. This prevents against accidental modification by software
12227 running as @code{root} or by system administrators.
12229 The daemon itself is still able to write to the store: it remounts it
12230 read-write in its own ``name space.''
12233 @defvr {Scheme Variable} %binary-format-file-system
12234 The @code{binfmt_misc} file system, which allows handling of arbitrary
12235 executable file types to be delegated to user space. This requires the
12236 @code{binfmt.ko} kernel module to be loaded.
12239 @defvr {Scheme Variable} %fuse-control-file-system
12240 The @code{fusectl} file system, which allows unprivileged users to mount
12241 and unmount user-space FUSE file systems. This requires the
12242 @code{fuse.ko} kernel module to be loaded.
12245 @node Btrfs file system
12246 @subsection Btrfs file system
12248 The Btrfs has special features, such as subvolumes, that merit being
12249 explained in more details. The following section attempts to cover
12250 basic as well as complex uses of a Btrfs file system with the Guix
12253 In its simplest usage, a Btrfs file system can be described, for
12258 (mount-point "/home")
12260 (device (file-system-label "my-home")))
12263 The example below is more complex, as it makes use of a Btrfs
12264 subvolume, named @code{rootfs}. The parent Btrfs file system is labeled
12265 @code{my-btrfs-pool}, and is located on an encrypted device (hence the
12266 dependency on @code{mapped-devices}):
12270 (device (file-system-label "my-btrfs-pool"))
12273 (options "subvol=rootfs")
12274 (dependencies mapped-devices))
12277 Some bootloaders, for example GRUB, only mount a Btrfs partition at its
12278 top level during the early boot, and rely on their configuration to
12279 refer to the correct subvolume path within that top level. The
12280 bootloaders operating in this way typically produce their configuration
12281 on a running system where the Btrfs partitions are already mounted and
12282 where the subvolume information is readily available. As an example,
12283 @command{grub-mkconfig}, the configuration generator command shipped
12284 with GRUB, reads @file{/proc/self/mountinfo} to determine the top-level
12285 path of a subvolume.
12287 The Guix System produces a bootloader configuration using the operating
12288 system configuration as its sole input; it is therefore necessary to
12289 extract the subvolume name on which @file{/gnu/store} lives (if any)
12290 from that operating system configuration. To better illustrate,
12291 consider a subvolume named 'rootfs' which contains the root file system
12292 data. In such situation, the GRUB bootloader would only see the top
12293 level of the root Btrfs partition, e.g.:
12297 ├── rootfs (subvolume directory)
12298 ├── gnu (normal directory)
12299 ├── store (normal directory)
12303 Thus, the subvolume name must be prepended to the @file{/gnu/store} path
12304 of the kernel, initrd binaries and any other files referred to in the
12305 GRUB configuration that must be found during the early boot.
12307 The next example shows a nested hierarchy of subvolumes and
12312 ├── rootfs (subvolume)
12313 ├── gnu (normal directory)
12314 ├── store (subvolume)
12318 This scenario would work without mounting the 'store' subvolume.
12319 Mounting 'rootfs' is sufficient, since the subvolume name matches its
12320 intended mount point in the file system hierarchy. Alternatively, the
12321 'store' subvolume could be referred to by setting the @code{subvol}
12322 option to either @code{/rootfs/gnu/store} or @code{rootfs/gnu/store}.
12324 Finally, a more contrived example of nested subvolumes:
12328 ├── root-snapshots (subvolume)
12329 ├── root-current (subvolume)
12330 ├── guix-store (subvolume)
12334 Here, the 'guix-store' subvolume doesn't match its intended mount point,
12335 so it is necessary to mount it. The subvolume must be fully specified,
12336 by passing its file name to the @code{subvol} option. To illustrate,
12337 the 'guix-store' subvolume could be mounted on @file{/gnu/store} by using
12338 a file system declaration such as:
12342 (device (file-system-label "btrfs-pool-1"))
12343 (mount-point "/gnu/store")
12345 (options "subvol=root-snapshots/root-current/guix-store,\
12346 compress-force=zstd,space_cache=v2"))
12349 @node Mapped Devices
12350 @section Mapped Devices
12352 @cindex device mapping
12353 @cindex mapped devices
12354 The Linux kernel has a notion of @dfn{device mapping}: a block device,
12355 such as a hard disk partition, can be @dfn{mapped} into another device,
12356 usually in @code{/dev/mapper/},
12357 with additional processing over the data that flows through
12358 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
12359 concept of a ``mapped device'' and that of a file system: both boil down
12360 to @emph{translating} input/output operations made on a file to
12361 operations on its backing store. Thus, the Hurd implements mapped
12362 devices, like file systems, using the generic @dfn{translator} mechanism
12363 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
12364 typical example is encryption device mapping: all writes to the mapped
12365 device are encrypted, and all reads are deciphered, transparently.
12366 Guix extends this notion by considering any device or set of devices that
12367 are @dfn{transformed} in some way to create a new device; for instance,
12368 RAID devices are obtained by @dfn{assembling} several other devices, such
12369 as hard disks or partitions, into a new one that behaves as one partition.
12370 Other examples, not yet implemented, are LVM logical volumes.
12372 Mapped devices are declared using the @code{mapped-device} form,
12373 defined as follows; for examples, see below.
12375 @deftp {Data Type} mapped-device
12376 Objects of this type represent device mappings that will be made when
12377 the system boots up.
12381 This is either a string specifying the name of the block device to be mapped,
12382 such as @code{"/dev/sda3"}, or a list of such strings when several devices
12383 need to be assembled for creating a new one.
12386 This string specifies the name of the resulting mapped device. For
12387 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
12388 specifying @code{"my-partition"} leads to the creation of
12389 the @code{"/dev/mapper/my-partition"} device.
12390 For RAID devices of type @code{raid-device-mapping}, the full device name
12391 such as @code{"/dev/md0"} needs to be given.
12394 This must be a @code{mapped-device-kind} object, which specifies how
12395 @var{source} is mapped to @var{target}.
12399 @defvr {Scheme Variable} luks-device-mapping
12400 This defines LUKS block device encryption using the @command{cryptsetup}
12401 command from the package with the same name. It relies on the
12402 @code{dm-crypt} Linux kernel module.
12405 @defvr {Scheme Variable} raid-device-mapping
12406 This defines a RAID device, which is assembled using the @code{mdadm}
12407 command from the package with the same name. It requires a Linux kernel
12408 module for the appropriate RAID level to be loaded, such as @code{raid456}
12409 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
12412 @cindex disk encryption
12414 The following example specifies a mapping from @file{/dev/sda3} to
12415 @file{/dev/mapper/home} using LUKS---the
12416 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
12417 standard mechanism for disk encryption.
12418 The @file{/dev/mapper/home}
12419 device can then be used as the @code{device} of a @code{file-system}
12420 declaration (@pxref{File Systems}).
12424 (source "/dev/sda3")
12426 (type luks-device-mapping))
12429 Alternatively, to become independent of device numbering, one may obtain
12430 the LUKS UUID (@dfn{unique identifier}) of the source device by a
12434 cryptsetup luksUUID /dev/sda3
12437 and use it as follows:
12441 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
12443 (type luks-device-mapping))
12446 @cindex swap encryption
12447 It is also desirable to encrypt swap space, since swap space may contain
12448 sensitive data. One way to accomplish that is to use a swap file in a
12449 file system on a device mapped via LUKS encryption. In this way, the
12450 swap file is encrypted because the entire device is encrypted.
12451 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
12453 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
12454 may be declared as follows:
12458 (source (list "/dev/sda1" "/dev/sdb1"))
12459 (target "/dev/md0")
12460 (type raid-device-mapping))
12463 The @file{/dev/md0} device can then be used as the @code{device} of a
12464 @code{file-system} declaration (@pxref{File Systems}).
12465 Note that the RAID level need not be given; it is chosen during the
12466 initial creation and formatting of the RAID device and is determined
12467 automatically later.
12470 @node User Accounts
12471 @section User Accounts
12475 @cindex user accounts
12476 User accounts and groups are entirely managed through the
12477 @code{operating-system} declaration. They are specified with the
12478 @code{user-account} and @code{user-group} forms:
12484 (supplementary-groups '("wheel" ;allow use of sudo, etc.
12485 "audio" ;sound card
12486 "video" ;video devices such as webcams
12487 "cdrom")) ;the good ol' CD-ROM
12488 (comment "Bob's sister")
12489 (home-directory "/home/alice"))
12492 When booting or upon completion of @command{guix system reconfigure},
12493 the system ensures that only the user accounts and groups specified in
12494 the @code{operating-system} declaration exist, and with the specified
12495 properties. Thus, account or group creations or modifications made by
12496 directly invoking commands such as @command{useradd} are lost upon
12497 reconfiguration or reboot. This ensures that the system remains exactly
12500 @deftp {Data Type} user-account
12501 Objects of this type represent user accounts. The following members may
12506 The name of the user account.
12510 This is the name (a string) or identifier (a number) of the user group
12511 this account belongs to.
12513 @item @code{supplementary-groups} (default: @code{'()})
12514 Optionally, this can be defined as a list of group names that this
12515 account belongs to.
12517 @item @code{uid} (default: @code{#f})
12518 This is the user ID for this account (a number), or @code{#f}. In the
12519 latter case, a number is automatically chosen by the system when the
12520 account is created.
12522 @item @code{comment} (default: @code{""})
12523 A comment about the account, such as the account owner's full name.
12525 @item @code{home-directory}
12526 This is the name of the home directory for the account.
12528 @item @code{create-home-directory?} (default: @code{#t})
12529 Indicates whether the home directory of this account should be created
12530 if it does not exist yet.
12532 @item @code{shell} (default: Bash)
12533 This is a G-expression denoting the file name of a program to be used as
12534 the shell (@pxref{G-Expressions}).
12536 @item @code{system?} (default: @code{#f})
12537 This Boolean value indicates whether the account is a ``system''
12538 account. System accounts are sometimes treated specially; for instance,
12539 graphical login managers do not list them.
12541 @anchor{user-account-password}
12542 @cindex password, for user accounts
12543 @item @code{password} (default: @code{#f})
12544 You would normally leave this field to @code{#f}, initialize user
12545 passwords as @code{root} with the @command{passwd} command, and then let
12546 users change it with @command{passwd}. Passwords set with
12547 @command{passwd} are of course preserved across reboot and
12550 If you @emph{do} want to set an initial password for an account, then
12551 this field must contain the encrypted password, as a string. You can use the
12552 @code{crypt} procedure for this purpose:
12559 ;; Specify a SHA-512-hashed initial password.
12560 (password (crypt "InitialPassword!" "$6$abc")))
12564 The hash of this initial password will be available in a file in
12565 @file{/gnu/store}, readable by all the users, so this method must be used with
12569 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
12570 more information on password encryption, and @ref{Encryption,,, guile, GNU
12571 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
12577 User group declarations are even simpler:
12580 (user-group (name "students"))
12583 @deftp {Data Type} user-group
12584 This type is for, well, user groups. There are just a few fields:
12588 The name of the group.
12590 @item @code{id} (default: @code{#f})
12591 The group identifier (a number). If @code{#f}, a new number is
12592 automatically allocated when the group is created.
12594 @item @code{system?} (default: @code{#f})
12595 This Boolean value indicates whether the group is a ``system'' group.
12596 System groups have low numerical IDs.
12598 @item @code{password} (default: @code{#f})
12599 What, user groups can have a password? Well, apparently yes. Unless
12600 @code{#f}, this field specifies the password of the group.
12605 For convenience, a variable lists all the basic user groups one may
12608 @defvr {Scheme Variable} %base-groups
12609 This is the list of basic user groups that users and/or packages expect
12610 to be present on the system. This includes groups such as ``root'',
12611 ``wheel'', and ``users'', as well as groups used to control access to
12612 specific devices such as ``audio'', ``disk'', and ``cdrom''.
12615 @defvr {Scheme Variable} %base-user-accounts
12616 This is the list of basic system accounts that programs may expect to
12617 find on a GNU/Linux system, such as the ``nobody'' account.
12619 Note that the ``root'' account is not included here. It is a
12620 special-case and is automatically added whether or not it is specified.
12623 @node Keyboard Layout
12624 @section Keyboard Layout
12626 @cindex keyboard layout
12628 To specify what each key of your keyboard does, you need to tell the operating
12629 system what @dfn{keyboard layout} you want to use. The default, when nothing
12630 is specified, is the US English QWERTY layout for 105-key PC keyboards.
12631 However, German speakers will usually prefer the German QWERTZ layout, French
12632 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
12633 or bépo, and they might even want to further customize the effect of some of
12634 the keys. This section explains how to get that done.
12636 @cindex keyboard layout, definition
12637 There are three components that will want to know about your keyboard layout:
12641 The @emph{bootloader} may want to know what keyboard layout you want to use
12642 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
12643 you want, for instance, to make sure that you can type the passphrase of your
12644 encrypted root partition using the right layout.
12647 The @emph{operating system kernel}, Linux, will need that so that the console
12648 is properly configured (@pxref{operating-system Reference,
12649 @code{keyboard-layout}}).
12652 The @emph{graphical display server}, usually Xorg, also has its own idea of
12653 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
12656 Guix allows you to configure all three separately but, fortunately, it allows
12657 you to share the same keyboard layout for all three components.
12659 @cindex XKB, keyboard layouts
12660 Keyboard layouts are represented by records created by the
12661 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
12662 the X Keyboard extension (XKB), each layout has four attributes: a name (often
12663 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
12664 optional variant name, an optional keyboard model name, and a possibly empty
12665 list of additional options. In most cases the layout name is all you care
12666 about. Here are a few example:
12669 ;; The German QWERTZ layout. Here we assume a standard
12670 ;; "pc105" keyboard model.
12671 (keyboard-layout "de")
12673 ;; The bépo variant of the French layout.
12674 (keyboard-layout "fr" "bepo")
12676 ;; The Catalan layout.
12677 (keyboard-layout "es" "cat")
12679 ;; Arabic layout with "Alt-Shift" to switch to US layout.
12680 (keyboard-layout "ar,us" #:options '("grp:alt_shift_toggle"))
12682 ;; The Latin American Spanish layout. In addition, the
12683 ;; "Caps Lock" key is used as an additional "Ctrl" key,
12684 ;; and the "Menu" key is used as a "Compose" key to enter
12685 ;; accented letters.
12686 (keyboard-layout "latam"
12687 #:options '("ctrl:nocaps" "compose:menu"))
12689 ;; The Russian layout for a ThinkPad keyboard.
12690 (keyboard-layout "ru" #:model "thinkpad")
12692 ;; The "US international" layout, which is the US layout plus
12693 ;; dead keys to enter accented characters. This is for an
12694 ;; Apple MacBook keyboard.
12695 (keyboard-layout "us" "intl" #:model "macbook78")
12698 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
12699 for a complete list of supported layouts, variants, and models.
12701 @cindex keyboard layout, configuration
12702 Let's say you want your system to use the Turkish keyboard layout throughout
12703 your system---bootloader, console, and Xorg. Here's what your system
12704 configuration would look like:
12706 @findex set-xorg-configuration
12708 ;; Using the Turkish layout for the bootloader, the console,
12713 (keyboard-layout (keyboard-layout "tr")) ;for the console
12714 (bootloader (bootloader-configuration
12715 (bootloader grub-efi-bootloader)
12716 (target "/boot/efi")
12717 (keyboard-layout keyboard-layout))) ;for GRUB
12718 (services (cons (set-xorg-configuration
12719 (xorg-configuration ;for Xorg
12720 (keyboard-layout keyboard-layout)))
12721 %desktop-services)))
12724 In the example above, for GRUB and for Xorg, we just refer to the
12725 @code{keyboard-layout} field defined above, but we could just as well refer to
12726 a different layout. The @code{set-xorg-configuration} procedure communicates
12727 the desired Xorg configuration to the graphical log-in manager, by default
12730 We've discussed how to specify the @emph{default} keyboard layout of your
12731 system when it starts, but you can also adjust it at run time:
12735 If you're using GNOME, its settings panel has a ``Region & Language'' entry
12736 where you can select one or more keyboard layouts.
12739 Under Xorg, the @command{setxkbmap} command (from the same-named package)
12740 allows you to change the current layout. For example, this is how you would
12741 change the layout to US Dvorak:
12744 setxkbmap us dvorak
12748 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
12749 console. However, note that @code{loadkeys} does @emph{not} use the XKB
12750 keyboard layout categorization described above. The command below loads the
12751 French bépo layout:
12762 A @dfn{locale} defines cultural conventions for a particular language
12763 and region of the world (@pxref{Locales,,, libc, The GNU C Library
12764 Reference Manual}). Each locale has a name that typically has the form
12765 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
12766 @code{fr_LU.utf8} designates the locale for the French language, with
12767 cultural conventions from Luxembourg, and using the UTF-8 encoding.
12769 @cindex locale definition
12770 Usually, you will want to specify the default locale for the machine
12771 using the @code{locale} field of the @code{operating-system} declaration
12772 (@pxref{operating-system Reference, @code{locale}}).
12774 The selected locale is automatically added to the @dfn{locale
12775 definitions} known to the system if needed, with its codeset inferred
12776 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
12777 @code{UTF-8} codeset. Additional locale definitions can be specified in
12778 the @code{locale-definitions} slot of @code{operating-system}---this is
12779 useful, for instance, if the codeset could not be inferred from the
12780 locale name. The default set of locale definitions includes some widely
12781 used locales, but not all the available locales, in order to save space.
12783 For instance, to add the North Frisian locale for Germany, the value of
12787 (cons (locale-definition
12788 (name "fy_DE.utf8") (source "fy_DE"))
12789 %default-locale-definitions)
12792 Likewise, to save space, one might want @code{locale-definitions} to
12793 list only the locales that are actually used, as in:
12796 (list (locale-definition
12797 (name "ja_JP.eucjp") (source "ja_JP")
12798 (charset "EUC-JP")))
12802 The compiled locale definitions are available at
12803 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
12804 version, which is the default location where the GNU@tie{}libc provided
12805 by Guix looks for locale data. This can be overridden using the
12806 @env{LOCPATH} environment variable (@pxref{locales-and-locpath,
12807 @env{LOCPATH} and locale packages}).
12809 The @code{locale-definition} form is provided by the @code{(gnu system
12810 locale)} module. Details are given below.
12812 @deftp {Data Type} locale-definition
12813 This is the data type of a locale definition.
12818 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
12819 Reference Manual}, for more information on locale names.
12821 @item @code{source}
12822 The name of the source for that locale. This is typically the
12823 @code{@var{language}_@var{territory}} part of the locale name.
12825 @item @code{charset} (default: @code{"UTF-8"})
12826 The ``character set'' or ``code set'' for that locale,
12827 @uref{https://www.iana.org/assignments/character-sets, as defined by
12833 @defvr {Scheme Variable} %default-locale-definitions
12834 A list of commonly used UTF-8 locales, used as the default
12835 value of the @code{locale-definitions} field of @code{operating-system}
12838 @cindex locale name
12839 @cindex normalized codeset in locale names
12840 These locale definitions use the @dfn{normalized codeset} for the part
12841 that follows the dot in the name (@pxref{Using gettextized software,
12842 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
12843 instance it has @code{uk_UA.utf8} but @emph{not}, say,
12844 @code{uk_UA.UTF-8}.
12847 @subsection Locale Data Compatibility Considerations
12849 @cindex incompatibility, of locale data
12850 @code{operating-system} declarations provide a @code{locale-libcs} field
12851 to specify the GNU@tie{}libc packages that are used to compile locale
12852 declarations (@pxref{operating-system Reference}). ``Why would I
12853 care?'', you may ask. Well, it turns out that the binary format of
12854 locale data is occasionally incompatible from one libc version to
12857 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
12858 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
12859 For instance, a program linked against libc version 2.21 is unable to
12860 read locale data produced with libc 2.22; worse, that program
12861 @emph{aborts} instead of simply ignoring the incompatible locale
12862 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
12863 the incompatible locale data, which is already an improvement.}.
12864 Similarly, a program linked against libc 2.22 can read most, but not
12865 all, of the locale data from libc 2.21 (specifically, @env{LC_COLLATE}
12866 data is incompatible); thus calls to @code{setlocale} may fail, but
12867 programs will not abort.
12869 The ``problem'' with Guix is that users have a lot of freedom: They can
12870 choose whether and when to upgrade software in their profiles, and might
12871 be using a libc version different from the one the system administrator
12872 used to build the system-wide locale data.
12874 Fortunately, unprivileged users can also install their own locale data
12875 and define @env{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
12876 @env{GUIX_LOCPATH} and locale packages}).
12878 Still, it is best if the system-wide locale data at
12879 @file{/run/current-system/locale} is built for all the libc versions
12880 actually in use on the system, so that all the programs can access
12881 it---this is especially crucial on a multi-user system. To do that, the
12882 administrator can specify several libc packages in the
12883 @code{locale-libcs} field of @code{operating-system}:
12886 (use-package-modules base)
12890 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
12893 This example would lead to a system containing locale definitions for
12894 both libc 2.21 and the current version of libc in
12895 @file{/run/current-system/locale}.
12901 @cindex system services
12902 An important part of preparing an @code{operating-system} declaration is
12903 listing @dfn{system services} and their configuration (@pxref{Using the
12904 Configuration System}). System services are typically daemons launched
12905 when the system boots, or other actions needed at that time---e.g.,
12906 configuring network access.
12908 Guix has a broad definition of ``service'' (@pxref{Service
12909 Composition}), but many services are managed by the GNU@tie{}Shepherd
12910 (@pxref{Shepherd Services}). On a running system, the @command{herd}
12911 command allows you to list the available services, show their status,
12912 start and stop them, or do other specific operations (@pxref{Jump
12913 Start,,, shepherd, The GNU Shepherd Manual}). For example:
12919 The above command, run as @code{root}, lists the currently defined
12920 services. The @command{herd doc} command shows a synopsis of the given
12921 service and its associated actions:
12925 Run libc's name service cache daemon (nscd).
12927 # herd doc nscd action invalidate
12928 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
12931 The @command{start}, @command{stop}, and @command{restart} sub-commands
12932 have the effect you would expect. For instance, the commands below stop
12933 the nscd service and restart the Xorg display server:
12937 Service nscd has been stopped.
12938 # herd restart xorg-server
12939 Service xorg-server has been stopped.
12940 Service xorg-server has been started.
12943 The following sections document the available services, starting with
12944 the core services, that may be used in an @code{operating-system}
12948 * Base Services:: Essential system services.
12949 * Scheduled Job Execution:: The mcron service.
12950 * Log Rotation:: The rottlog service.
12951 * Networking Services:: Network setup, SSH daemon, etc.
12952 * Unattended Upgrades:: Automated system upgrades.
12953 * X Window:: Graphical display.
12954 * Printing Services:: Local and remote printer support.
12955 * Desktop Services:: D-Bus and desktop services.
12956 * Sound Services:: ALSA and Pulseaudio services.
12957 * Database Services:: SQL databases, key-value stores, etc.
12958 * Mail Services:: IMAP, POP3, SMTP, and all that.
12959 * Messaging Services:: Messaging services.
12960 * Telephony Services:: Telephony services.
12961 * Monitoring Services:: Monitoring services.
12962 * Kerberos Services:: Kerberos services.
12963 * LDAP Services:: LDAP services.
12964 * Web Services:: Web servers.
12965 * Certificate Services:: TLS certificates via Let's Encrypt.
12966 * DNS Services:: DNS daemons.
12967 * VPN Services:: VPN daemons.
12968 * Network File System:: NFS related services.
12969 * Continuous Integration:: The Cuirass service.
12970 * Power Management Services:: Extending battery life.
12971 * Audio Services:: The MPD.
12972 * Virtualization Services:: Virtualization services.
12973 * Version Control Services:: Providing remote access to Git repositories.
12974 * Game Services:: Game servers.
12975 * PAM Mount Service:: Service to mount volumes when logging in.
12976 * Guix Services:: Services relating specifically to Guix.
12977 * Linux Services:: Services tied to the Linux kernel.
12978 * Hurd Services:: Services specific for a Hurd System.
12979 * Miscellaneous Services:: Other services.
12982 @node Base Services
12983 @subsection Base Services
12985 The @code{(gnu services base)} module provides definitions for the basic
12986 services that one expects from the system. The services exported by
12987 this module are listed below.
12989 @defvr {Scheme Variable} %base-services
12990 This variable contains a list of basic services (@pxref{Service Types
12991 and Services}, for more information on service objects) one would
12992 expect from the system: a login service (mingetty) on each tty, syslogd,
12993 the libc name service cache daemon (nscd), the udev device manager, and
12996 This is the default value of the @code{services} field of
12997 @code{operating-system} declarations. Usually, when customizing a
12998 system, you will want to append services to @code{%base-services}, like
13002 (append (list (service avahi-service-type)
13003 (service openssh-service-type))
13008 @defvr {Scheme Variable} special-files-service-type
13009 This is the service that sets up ``special files'' such as
13010 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
13012 The value associated with @code{special-files-service-type} services
13013 must be a list of tuples where the first element is the ``special file''
13014 and the second element is its target. By default it is:
13016 @cindex @file{/bin/sh}
13017 @cindex @file{sh}, in @file{/bin}
13019 `(("/bin/sh" ,(file-append bash "/bin/sh")))
13022 @cindex @file{/usr/bin/env}
13023 @cindex @file{env}, in @file{/usr/bin}
13024 If you want to add, say, @code{/usr/bin/env} to your system, you can
13028 `(("/bin/sh" ,(file-append bash "/bin/sh"))
13029 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
13032 Since this is part of @code{%base-services}, you can use
13033 @code{modify-services} to customize the set of special files
13034 (@pxref{Service Reference, @code{modify-services}}). But the simple way
13035 to add a special file is @i{via} the @code{extra-special-file} procedure
13039 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
13040 Use @var{target} as the ``special file'' @var{file}.
13042 For example, adding the following lines to the @code{services} field of
13043 your operating system declaration leads to a @file{/usr/bin/env}
13047 (extra-special-file "/usr/bin/env"
13048 (file-append coreutils "/bin/env"))
13052 @deffn {Scheme Procedure} host-name-service @var{name}
13053 Return a service that sets the host name to @var{name}.
13056 @defvr {Scheme Variable} console-font-service-type
13057 Install the given fonts on the specified ttys (fonts are per
13058 virtual console on the kernel Linux). The value of this service is a list of
13059 tty/font pairs. The font can be the name of a font provided by the @code{kbd}
13060 package or any valid argument to @command{setfont}, as in this example:
13063 `(("tty1" . "LatGrkCyr-8x16")
13064 ("tty2" . ,(file-append
13066 "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
13067 ("tty3" . ,(file-append
13069 "/share/consolefonts/ter-132n"))) ; for HDPI
13073 @deffn {Scheme Procedure} login-service @var{config}
13074 Return a service to run login according to @var{config}, a
13075 @code{<login-configuration>} object, which specifies the message of the day,
13076 among other things.
13079 @deftp {Data Type} login-configuration
13080 This is the data type representing the configuration of login.
13085 @cindex message of the day
13086 A file-like object containing the ``message of the day''.
13088 @item @code{allow-empty-passwords?} (default: @code{#t})
13089 Allow empty passwords by default so that first-time users can log in when
13090 the 'root' account has just been created.
13095 @deffn {Scheme Procedure} mingetty-service @var{config}
13096 Return a service to run mingetty according to @var{config}, a
13097 @code{<mingetty-configuration>} object, which specifies the tty to run, among
13101 @deftp {Data Type} mingetty-configuration
13102 This is the data type representing the configuration of Mingetty, which
13103 provides the default implementation of virtual console log-in.
13108 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
13110 @item @code{auto-login} (default: @code{#f})
13111 When true, this field must be a string denoting the user name under
13112 which the system automatically logs in. When it is @code{#f}, a
13113 user name and password must be entered to log in.
13115 @item @code{login-program} (default: @code{#f})
13116 This must be either @code{#f}, in which case the default log-in program
13117 is used (@command{login} from the Shadow tool suite), or a gexp denoting
13118 the name of the log-in program.
13120 @item @code{login-pause?} (default: @code{#f})
13121 When set to @code{#t} in conjunction with @var{auto-login}, the user
13122 will have to press a key before the log-in shell is launched.
13124 @item @code{mingetty} (default: @var{mingetty})
13125 The Mingetty package to use.
13130 @deffn {Scheme Procedure} agetty-service @var{config}
13131 Return a service to run agetty according to @var{config}, an
13132 @code{<agetty-configuration>} object, which specifies the tty to run,
13133 among other things.
13136 @deftp {Data Type} agetty-configuration
13137 This is the data type representing the configuration of agetty, which
13138 implements virtual and serial console log-in. See the @code{agetty(8)}
13139 man page for more information.
13144 The name of the console this agetty runs on, as a string---e.g.,
13145 @code{"ttyS0"}. This argument is optional, it will default to
13146 a reasonable default serial port used by the kernel Linux.
13148 For this, if there is a value for an option @code{agetty.tty} in the kernel
13149 command line, agetty will extract the device name of the serial port
13150 from it and use that.
13152 If not and if there is a value for an option @code{console} with a tty in
13153 the Linux command line, agetty will extract the device name of the
13154 serial port from it and use that.
13156 In both cases, agetty will leave the other serial device settings
13157 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
13160 @item @code{baud-rate} (default: @code{#f})
13161 A string containing a comma-separated list of one or more baud rates, in
13164 @item @code{term} (default: @code{#f})
13165 A string containing the value used for the @env{TERM} environment
13168 @item @code{eight-bits?} (default: @code{#f})
13169 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
13172 @item @code{auto-login} (default: @code{#f})
13173 When passed a login name, as a string, the specified user will be logged
13174 in automatically without prompting for their login name or password.
13176 @item @code{no-reset?} (default: @code{#f})
13177 When @code{#t}, don't reset terminal cflags (control modes).
13179 @item @code{host} (default: @code{#f})
13180 This accepts a string containing the ``login_host'', which will be written
13181 into the @file{/var/run/utmpx} file.
13183 @item @code{remote?} (default: @code{#f})
13184 When set to @code{#t} in conjunction with @var{host}, this will add an
13185 @code{-r} fakehost option to the command line of the login program
13186 specified in @var{login-program}.
13188 @item @code{flow-control?} (default: @code{#f})
13189 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
13191 @item @code{no-issue?} (default: @code{#f})
13192 When set to @code{#t}, the contents of the @file{/etc/issue} file will
13193 not be displayed before presenting the login prompt.
13195 @item @code{init-string} (default: @code{#f})
13196 This accepts a string that will be sent to the tty or modem before
13197 sending anything else. It can be used to initialize a modem.
13199 @item @code{no-clear?} (default: @code{#f})
13200 When set to @code{#t}, agetty will not clear the screen before showing
13203 @item @code{login-program} (default: (file-append shadow "/bin/login"))
13204 This must be either a gexp denoting the name of a log-in program, or
13205 unset, in which case the default value is the @command{login} from the
13208 @item @code{local-line} (default: @code{#f})
13209 Control the CLOCAL line flag. This accepts one of three symbols as
13210 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
13211 the default value chosen by agetty is @code{'auto}.
13213 @item @code{extract-baud?} (default: @code{#f})
13214 When set to @code{#t}, instruct agetty to try to extract the baud rate
13215 from the status messages produced by certain types of modems.
13217 @item @code{skip-login?} (default: @code{#f})
13218 When set to @code{#t}, do not prompt the user for a login name. This
13219 can be used with @var{login-program} field to use non-standard login
13222 @item @code{no-newline?} (default: @code{#f})
13223 When set to @code{#t}, do not print a newline before printing the
13224 @file{/etc/issue} file.
13226 @c Is this dangerous only when used with login-program, or always?
13227 @item @code{login-options} (default: @code{#f})
13228 This option accepts a string containing options that are passed to the
13229 login program. When used with the @var{login-program}, be aware that a
13230 malicious user could try to enter a login name containing embedded
13231 options that could be parsed by the login program.
13233 @item @code{login-pause} (default: @code{#f})
13234 When set to @code{#t}, wait for any key before showing the login prompt.
13235 This can be used in conjunction with @var{auto-login} to save memory by
13236 lazily spawning shells.
13238 @item @code{chroot} (default: @code{#f})
13239 Change root to the specified directory. This option accepts a directory
13242 @item @code{hangup?} (default: @code{#f})
13243 Use the Linux system call @code{vhangup} to do a virtual hangup of the
13244 specified terminal.
13246 @item @code{keep-baud?} (default: @code{#f})
13247 When set to @code{#t}, try to keep the existing baud rate. The baud
13248 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
13251 @item @code{timeout} (default: @code{#f})
13252 When set to an integer value, terminate if no user name could be read
13253 within @var{timeout} seconds.
13255 @item @code{detect-case?} (default: @code{#f})
13256 When set to @code{#t}, turn on support for detecting an uppercase-only
13257 terminal. This setting will detect a login name containing only
13258 uppercase letters as indicating an uppercase-only terminal and turn on
13259 some upper-to-lower case conversions. Note that this will not support
13260 Unicode characters.
13262 @item @code{wait-cr?} (default: @code{#f})
13263 When set to @code{#t}, wait for the user or modem to send a
13264 carriage-return or linefeed character before displaying
13265 @file{/etc/issue} or login prompt. This is typically used with the
13266 @var{init-string} option.
13268 @item @code{no-hints?} (default: @code{#f})
13269 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
13272 @item @code{no-hostname?} (default: @code{#f})
13273 By default, the hostname is printed. When this option is set to
13274 @code{#t}, no hostname will be shown at all.
13276 @item @code{long-hostname?} (default: @code{#f})
13277 By default, the hostname is only printed until the first dot. When this
13278 option is set to @code{#t}, the fully qualified hostname by
13279 @code{gethostname} or @code{getaddrinfo} is shown.
13281 @item @code{erase-characters} (default: @code{#f})
13282 This option accepts a string of additional characters that should be
13283 interpreted as backspace when the user types their login name.
13285 @item @code{kill-characters} (default: @code{#f})
13286 This option accepts a string that should be interpreted to mean ``ignore
13287 all previous characters'' (also called a ``kill'' character) when the user
13288 types their login name.
13290 @item @code{chdir} (default: @code{#f})
13291 This option accepts, as a string, a directory path that will be changed
13294 @item @code{delay} (default: @code{#f})
13295 This options accepts, as an integer, the number of seconds to sleep
13296 before opening the tty and displaying the login prompt.
13298 @item @code{nice} (default: @code{#f})
13299 This option accepts, as an integer, the nice value with which to run the
13300 @command{login} program.
13302 @item @code{extra-options} (default: @code{'()})
13303 This option provides an ``escape hatch'' for the user to provide arbitrary
13304 command-line arguments to @command{agetty} as a list of strings.
13309 @deffn {Scheme Procedure} kmscon-service-type @var{config}
13310 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
13311 according to @var{config}, a @code{<kmscon-configuration>} object, which
13312 specifies the tty to run, among other things.
13315 @deftp {Data Type} kmscon-configuration
13316 This is the data type representing the configuration of Kmscon, which
13317 implements virtual console log-in.
13321 @item @code{virtual-terminal}
13322 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
13324 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
13325 A gexp denoting the name of the log-in program. The default log-in program is
13326 @command{login} from the Shadow tool suite.
13328 @item @code{login-arguments} (default: @code{'("-p")})
13329 A list of arguments to pass to @command{login}.
13331 @item @code{auto-login} (default: @code{#f})
13332 When passed a login name, as a string, the specified user will be logged
13333 in automatically without prompting for their login name or password.
13335 @item @code{hardware-acceleration?} (default: #f)
13336 Whether to use hardware acceleration.
13338 @item @code{kmscon} (default: @var{kmscon})
13339 The Kmscon package to use.
13344 @cindex name service cache daemon
13346 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
13347 [#:name-services '()]
13348 Return a service that runs the libc name service cache daemon (nscd) with the
13349 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
13350 Service Switch}, for an example.
13352 For convenience, the Shepherd service for nscd provides the following actions:
13356 @cindex cache invalidation, nscd
13357 @cindex nscd, cache invalidation
13358 This invalidate the given cache. For instance, running:
13361 herd invalidate nscd hosts
13365 invalidates the host name lookup cache of nscd.
13368 Running @command{herd statistics nscd} displays information about nscd usage
13374 @defvr {Scheme Variable} %nscd-default-configuration
13375 This is the default @code{<nscd-configuration>} value (see below) used
13376 by @code{nscd-service}. It uses the caches defined by
13377 @code{%nscd-default-caches}; see below.
13380 @deftp {Data Type} nscd-configuration
13381 This is the data type representing the name service cache daemon (nscd)
13386 @item @code{name-services} (default: @code{'()})
13387 List of packages denoting @dfn{name services} that must be visible to
13388 the nscd---e.g., @code{(list @var{nss-mdns})}.
13390 @item @code{glibc} (default: @var{glibc})
13391 Package object denoting the GNU C Library providing the @command{nscd}
13394 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
13395 Name of the nscd log file. This is where debugging output goes when
13396 @code{debug-level} is strictly positive.
13398 @item @code{debug-level} (default: @code{0})
13399 Integer denoting the debugging levels. Higher numbers mean that more
13400 debugging output is logged.
13402 @item @code{caches} (default: @code{%nscd-default-caches})
13403 List of @code{<nscd-cache>} objects denoting things to be cached; see
13409 @deftp {Data Type} nscd-cache
13410 Data type representing a cache database of nscd and its parameters.
13414 @item @code{database}
13415 This is a symbol representing the name of the database to be cached.
13416 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
13417 @code{services}, which designate the corresponding NSS database
13418 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
13420 @item @code{positive-time-to-live}
13421 @itemx @code{negative-time-to-live} (default: @code{20})
13422 A number representing the number of seconds during which a positive or
13423 negative lookup result remains in cache.
13425 @item @code{check-files?} (default: @code{#t})
13426 Whether to check for updates of the files corresponding to
13429 For instance, when @var{database} is @code{hosts}, setting this flag
13430 instructs nscd to check for updates in @file{/etc/hosts} and to take
13433 @item @code{persistent?} (default: @code{#t})
13434 Whether the cache should be stored persistently on disk.
13436 @item @code{shared?} (default: @code{#t})
13437 Whether the cache should be shared among users.
13439 @item @code{max-database-size} (default: 32@tie{}MiB)
13440 Maximum size in bytes of the database cache.
13442 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
13443 @c settings, so leave them out.
13448 @defvr {Scheme Variable} %nscd-default-caches
13449 List of @code{<nscd-cache>} objects used by default by
13450 @code{nscd-configuration} (see above).
13452 It enables persistent and aggressive caching of service and host name
13453 lookups. The latter provides better host name lookup performance,
13454 resilience in the face of unreliable name servers, and also better
13455 privacy---often the result of host name lookups is in local cache, so
13456 external name servers do not even need to be queried.
13459 @anchor{syslog-configuration-type}
13462 @deftp {Data Type} syslog-configuration
13463 This data type represents the configuration of the syslog daemon.
13466 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
13467 The syslog daemon to use.
13469 @item @code{config-file} (default: @code{%default-syslog.conf})
13470 The syslog configuration file to use.
13475 @anchor{syslog-service}
13477 @deffn {Scheme Procedure} syslog-service @var{config}
13478 Return a service that runs a syslog daemon according to @var{config}.
13480 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
13481 information on the configuration file syntax.
13484 @defvr {Scheme Variable} guix-service-type
13485 This is the type of the service that runs the build daemon,
13486 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
13487 @code{guix-configuration} record as described below.
13490 @anchor{guix-configuration-type}
13491 @deftp {Data Type} guix-configuration
13492 This data type represents the configuration of the Guix build daemon.
13493 @xref{Invoking guix-daemon}, for more information.
13496 @item @code{guix} (default: @var{guix})
13497 The Guix package to use.
13499 @item @code{build-group} (default: @code{"guixbuild"})
13500 Name of the group for build user accounts.
13502 @item @code{build-accounts} (default: @code{10})
13503 Number of build user accounts to create.
13505 @item @code{authorize-key?} (default: @code{#t})
13506 @cindex substitutes, authorization thereof
13507 Whether to authorize the substitute keys listed in
13508 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
13509 (@pxref{Substitutes}).
13511 @vindex %default-authorized-guix-keys
13512 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
13513 The list of authorized key files for archive imports, as a list of
13514 string-valued gexps (@pxref{Invoking guix archive}). By default, it
13515 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
13517 @item @code{use-substitutes?} (default: @code{#t})
13518 Whether to use substitutes.
13520 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
13521 The list of URLs where to look for substitutes by default.
13523 @item @code{max-silent-time} (default: @code{0})
13524 @itemx @code{timeout} (default: @code{0})
13525 The number of seconds of silence and the number of seconds of activity,
13526 respectively, after which a build process times out. A value of zero
13527 disables the timeout.
13529 @item @code{log-compression} (default: @code{'bzip2})
13530 The type of compression used for build logs---one of @code{gzip},
13531 @code{bzip2}, or @code{none}.
13533 @item @code{extra-options} (default: @code{'()})
13534 List of extra command-line options for @command{guix-daemon}.
13536 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
13537 File where @command{guix-daemon}'s standard output and standard error
13540 @cindex HTTP proxy, for @code{guix-daemon}
13541 @cindex proxy, for @code{guix-daemon} HTTP access
13542 @item @code{http-proxy} (default: @code{#f})
13543 The URL of the HTTP and HTTPS proxy used for downloading fixed-output
13544 derivations and substitutes.
13546 It is also possible to change the daemon's proxy at run time through the
13547 @code{set-http-proxy} action, which restarts it:
13550 herd set-http-proxy guix-daemon http://localhost:8118
13553 To clear the proxy settings, run:
13556 herd set-http-proxy guix-daemon
13559 @item @code{tmpdir} (default: @code{#f})
13560 A directory path where the @command{guix-daemon} will perform builds.
13565 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
13566 Run @var{udev}, which populates the @file{/dev} directory dynamically.
13567 udev rules can be provided as a list of files through the @var{rules}
13568 variable. The procedures @code{udev-rule}, @code{udev-rules-service}
13569 and @code{file->udev-rule} from @code{(gnu services base)} simplify the
13570 creation of such rule files.
13572 The @command{herd rules udev} command, as root, returns the name of the
13573 directory containing all the active udev rules.
13576 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
13577 Return a udev-rule file named @var{file-name} containing the rules
13578 defined by the @var{contents} literal.
13580 In the following example, a rule for a USB device is defined to be
13581 stored in the file @file{90-usb-thing.rules}. The rule runs a script
13582 upon detecting a USB device with a given product identifier.
13585 (define %example-udev-rule
13587 "90-usb-thing.rules"
13588 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
13589 "ATTR@{product@}==\"Example\", "
13590 "RUN+=\"/path/to/script\"")))
13594 @deffn {Scheme Procedure} udev-rules-service [@var{name} @var{rules}] @
13595 [#:groups @var{groups}]
13596 Return a service that extends @code{udev-service-type } with @var{rules}
13597 and @code{account-service-type} with @var{groups} as system groups.
13598 This works by creating a singleton service type
13599 @code{@var{name}-udev-rules}, of which the returned service is an
13602 Here we show how it can be used to extend @code{udev-service-type} with the
13603 previously defined rule @code{%example-udev-rule}.
13609 (cons (udev-rules-service 'usb-thing %example-udev-rule)
13610 %desktop-services)))
13614 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
13615 Return a udev file named @var{file-name} containing the rules defined
13616 within @var{file}, a file-like object.
13618 The following example showcases how we can use an existing rule file.
13621 (use-modules (guix download) ;for url-fetch
13622 (guix packages) ;for origin
13625 (define %android-udev-rules
13627 "51-android-udev.rules"
13628 (let ((version "20170910"))
13631 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
13632 "android-udev-rules/" version "/51-android.rules"))
13634 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
13638 Additionally, Guix package definitions can be included in @var{rules} in
13639 order to extend the udev rules with the definitions found under their
13640 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
13641 @var{file->udev-rule} example, we could have used the
13642 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
13643 packages android)} module.
13645 The following example shows how to use the @var{android-udev-rules}
13646 package so that the Android tool @command{adb} can detect devices
13647 without root privileges. It also details how to create the
13648 @code{adbusers} group, which is required for the proper functioning of
13649 the rules defined within the @code{android-udev-rules} package. To
13650 create such a group, we must define it both as part of the
13651 @code{supplementary-groups} of our @code{user-account} declaration, as
13652 well as in the @var{groups} of the @code{udev-rules-service} procedure.
13655 (use-modules (gnu packages android) ;for android-udev-rules
13656 (gnu system shadow) ;for user-group
13661 (users (cons (user-account
13663 (supplementary-groups
13664 '("adbusers" ;for adb
13665 "wheel" "netdev" "audio" "video")))))
13668 (cons (udev-rules-service 'android android-udev-rules
13669 #:groups '("adbusers"))
13670 %desktop-services)))
13673 @defvr {Scheme Variable} urandom-seed-service-type
13674 Save some entropy in @code{%random-seed-file} to seed @file{/dev/urandom}
13675 when rebooting. It also tries to seed @file{/dev/urandom} from
13676 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
13680 @defvr {Scheme Variable} %random-seed-file
13681 This is the name of the file where some random bytes are saved by
13682 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
13683 It defaults to @file{/var/lib/random-seed}.
13688 @defvr {Scheme Variable} gpm-service-type
13689 This is the type of the service that runs GPM, the @dfn{general-purpose
13690 mouse daemon}, which provides mouse support to the Linux console. GPM
13691 allows users to use the mouse in the console, notably to select, copy,
13694 The value for services of this type must be a @code{gpm-configuration}
13695 (see below). This service is not part of @code{%base-services}.
13698 @deftp {Data Type} gpm-configuration
13699 Data type representing the configuration of GPM.
13702 @item @code{options} (default: @code{%default-gpm-options})
13703 Command-line options passed to @command{gpm}. The default set of
13704 options instruct @command{gpm} to listen to mouse events on
13705 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
13708 @item @code{gpm} (default: @code{gpm})
13709 The GPM package to use.
13714 @anchor{guix-publish-service-type}
13715 @deffn {Scheme Variable} guix-publish-service-type
13716 This is the service type for @command{guix publish} (@pxref{Invoking
13717 guix publish}). Its value must be a @code{guix-publish-configuration}
13718 object, as described below.
13720 This assumes that @file{/etc/guix} already contains a signing key pair as
13721 created by @command{guix archive --generate-key} (@pxref{Invoking guix
13722 archive}). If that is not the case, the service will fail to start.
13725 @deftp {Data Type} guix-publish-configuration
13726 Data type representing the configuration of the @code{guix publish}
13730 @item @code{guix} (default: @code{guix})
13731 The Guix package to use.
13733 @item @code{port} (default: @code{80})
13734 The TCP port to listen for connections.
13736 @item @code{host} (default: @code{"localhost"})
13737 The host (and thus, network interface) to listen to. Use
13738 @code{"0.0.0.0"} to listen on all the network interfaces.
13740 @item @code{compression} (default: @code{'(("gzip" 3))})
13741 This is a list of compression method/level tuple used when compressing
13742 substitutes. For example, to compress all substitutes with @emph{both} lzip
13743 at level 7 and gzip at level 9, write:
13746 '(("lzip" 7) ("gzip" 9))
13749 Level 9 achieves the best compression ratio at the expense of increased CPU
13750 usage, whereas level 1 achieves fast compression.
13752 An empty list disables compression altogether.
13754 @item @code{nar-path} (default: @code{"nar"})
13755 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
13756 publish, @option{--nar-path}}, for details.
13758 @item @code{cache} (default: @code{#f})
13759 When it is @code{#f}, disable caching and instead generate archives on
13760 demand. Otherwise, this should be the name of a directory---e.g.,
13761 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
13762 archives and meta-data ready to be sent. @xref{Invoking guix publish,
13763 @option{--cache}}, for more information on the tradeoffs involved.
13765 @item @code{workers} (default: @code{#f})
13766 When it is an integer, this is the number of worker threads used for
13767 caching; when @code{#f}, the number of processors is used.
13768 @xref{Invoking guix publish, @option{--workers}}, for more information.
13770 @item @code{ttl} (default: @code{#f})
13771 When it is an integer, this denotes the @dfn{time-to-live} in seconds
13772 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
13773 for more information.
13777 @anchor{rngd-service}
13778 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
13779 [#:device "/dev/hwrng"]
13780 Return a service that runs the @command{rngd} program from @var{rng-tools}
13781 to add @var{device} to the kernel's entropy pool. The service will fail if
13782 @var{device} does not exist.
13785 @anchor{pam-limits-service}
13786 @cindex session limits
13791 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
13793 Return a service that installs a configuration file for the
13794 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
13795 @code{pam_limits} module}. The procedure optionally takes a list of
13796 @code{pam-limits-entry} values, which can be used to specify
13797 @code{ulimit} limits and nice priority limits to user sessions.
13799 The following limits definition sets two hard and soft limits for all
13800 login sessions of users in the @code{realtime} group:
13803 (pam-limits-service
13805 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
13806 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
13809 The first entry increases the maximum realtime priority for
13810 non-privileged processes; the second entry lifts any restriction of the
13811 maximum address space that can be locked in memory. These settings are
13812 commonly used for real-time audio systems.
13815 @node Scheduled Job Execution
13816 @subsection Scheduled Job Execution
13820 @cindex scheduling jobs
13821 The @code{(gnu services mcron)} module provides an interface to
13822 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
13823 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
13824 Unix @command{cron} daemon; the main difference is that it is
13825 implemented in Guile Scheme, which provides a lot of flexibility when
13826 specifying the scheduling of jobs and their actions.
13828 The example below defines an operating system that runs the
13829 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
13830 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
13831 well as the @command{mkid} command on behalf of an unprivileged user
13832 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
13833 gexps to introduce job definitions that are passed to mcron
13834 (@pxref{G-Expressions}).
13837 (use-modules (guix) (gnu) (gnu services mcron))
13838 (use-package-modules base idutils)
13840 (define updatedb-job
13841 ;; Run 'updatedb' at 3AM every day. Here we write the
13842 ;; job's action as a Scheme procedure.
13843 #~(job '(next-hour '(3))
13845 (execl (string-append #$findutils "/bin/updatedb")
13847 "--prunepaths=/tmp /var/tmp /gnu/store"))))
13849 (define garbage-collector-job
13850 ;; Collect garbage 5 minutes after midnight every day.
13851 ;; The job's action is a shell command.
13852 #~(job "5 0 * * *" ;Vixie cron syntax
13855 (define idutils-job
13856 ;; Update the index database as user "charlie" at 12:15PM
13857 ;; and 19:15PM. This runs from the user's home directory.
13858 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
13859 (string-append #$idutils "/bin/mkid src")
13864 (services (cons (service mcron-service-type
13865 (mcron-configuration
13866 (jobs (list garbage-collector-job
13872 For more complex jobs defined in Scheme where you need control over the top
13873 level, for instance to introduce a @code{use-modules} form, you can move your
13874 code to a separate program using the @code{program-file} procedure of the
13875 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
13879 (define %battery-alert-job
13880 ;; Beep when the battery percentage falls below %MIN-LEVEL.
13882 '(next-minute (range 0 60 1))
13884 "battery-alert.scm"
13885 (with-imported-modules (source-module-closure
13886 '((guix build utils)))
13888 (use-modules (guix build utils)
13891 (ice-9 textual-ports)
13894 (define %min-level 20)
13896 (setenv "LC_ALL" "C") ;ensure English output
13897 (and-let* ((input-pipe (open-pipe*
13899 #$(file-append acpi "/bin/acpi")))
13900 (output (get-string-all input-pipe))
13901 (m (string-match "Discharging, ([0-9]+)%" output))
13902 (level (string->number (match:substring m 1)))
13903 ((< level %min-level)))
13904 (format #t "warning: Battery level is low (~a%)~%" level)
13905 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
13908 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
13909 for more information on mcron job specifications. Below is the
13910 reference of the mcron service.
13912 On a running system, you can use the @code{schedule} action of the service to
13913 visualize the mcron jobs that will be executed next:
13916 # herd schedule mcron
13920 The example above lists the next five tasks that will be executed, but you can
13921 also specify the number of tasks to display:
13924 # herd schedule mcron 10
13927 @defvr {Scheme Variable} mcron-service-type
13928 This is the type of the @code{mcron} service, whose value is an
13929 @code{mcron-configuration} object.
13931 This service type can be the target of a service extension that provides
13932 it additional job specifications (@pxref{Service Composition}). In
13933 other words, it is possible to define services that provide additional
13937 @deftp {Data Type} mcron-configuration
13938 Data type representing the configuration of mcron.
13941 @item @code{mcron} (default: @var{mcron})
13942 The mcron package to use.
13945 This is a list of gexps (@pxref{G-Expressions}), where each gexp
13946 corresponds to an mcron job specification (@pxref{Syntax, mcron job
13947 specifications,, mcron, GNU@tie{}mcron}).
13953 @subsection Log Rotation
13956 @cindex log rotation
13958 Log files such as those found in @file{/var/log} tend to grow endlessly,
13959 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
13960 their contents in separate files, possibly compressed. The @code{(gnu
13961 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
13962 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
13964 This service is part of @code{%base-services}, and thus enabled by
13965 default, with the default settings, for commonly encountered log files.
13966 The example below shows how to extend it with an additional
13967 @dfn{rotation}, should you need to do that (usually, services that
13968 produce log files already take care of that):
13971 (use-modules (guix) (gnu))
13972 (use-service-modules admin)
13974 (define my-log-files
13975 ;; Log files that I want to rotate.
13976 '("/var/log/something.log" "/var/log/another.log"))
13980 (services (cons (simple-service 'rotate-my-stuff
13981 rottlog-service-type
13982 (list (log-rotation
13984 (files my-log-files))))
13988 @defvr {Scheme Variable} rottlog-service-type
13989 This is the type of the Rottlog service, whose value is a
13990 @code{rottlog-configuration} object.
13992 Other services can extend this one with new @code{log-rotation} objects
13993 (see below), thereby augmenting the set of files to be rotated.
13995 This service type can define mcron jobs (@pxref{Scheduled Job
13996 Execution}) to run the rottlog service.
13999 @deftp {Data Type} rottlog-configuration
14000 Data type representing the configuration of rottlog.
14003 @item @code{rottlog} (default: @code{rottlog})
14004 The Rottlog package to use.
14006 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
14007 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
14008 rottlog, GNU Rot[t]log Manual}).
14010 @item @code{rotations} (default: @code{%default-rotations})
14011 A list of @code{log-rotation} objects as defined below.
14014 This is a list of gexps where each gexp corresponds to an mcron job
14015 specification (@pxref{Scheduled Job Execution}).
14019 @deftp {Data Type} log-rotation
14020 Data type representing the rotation of a group of log files.
14022 Taking an example from the Rottlog manual (@pxref{Period Related File
14023 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
14029 (files '("/var/log/apache/*"))
14030 (options '("storedir apache-archives"
14036 The list of fields is as follows:
14039 @item @code{frequency} (default: @code{'weekly})
14040 The log rotation frequency, a symbol.
14043 The list of files or file glob patterns to rotate.
14045 @item @code{options} (default: @code{'()})
14046 The list of rottlog options for this rotation (@pxref{Configuration
14047 parameters,,, rottlog, GNU Rot[t]lg Manual}).
14049 @item @code{post-rotate} (default: @code{#f})
14050 Either @code{#f} or a gexp to execute once the rotation has completed.
14054 @defvr {Scheme Variable} %default-rotations
14055 Specifies weekly rotation of @code{%rotated-files} and of
14056 @file{/var/log/guix-daemon.log}.
14059 @defvr {Scheme Variable} %rotated-files
14060 The list of syslog-controlled files to be rotated. By default it is:
14061 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
14062 "/var/log/maillog")}.
14065 @node Networking Services
14066 @subsection Networking Services
14068 The @code{(gnu services networking)} module provides services to configure
14069 the network interface.
14071 @cindex DHCP, networking service
14072 @defvr {Scheme Variable} dhcp-client-service-type
14073 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
14074 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
14075 is the DHCP client package to use, @code{isc-dhcp} by default.
14078 @deffn {Scheme Procedure} dhcpd-service-type
14079 This type defines a service that runs a DHCP daemon. To create a
14080 service of this type, you must supply a @code{<dhcpd-configuration>}.
14084 (service dhcpd-service-type
14085 (dhcpd-configuration
14086 (config-file (local-file "my-dhcpd.conf"))
14087 (interfaces '("enp0s25"))))
14091 @deftp {Data Type} dhcpd-configuration
14093 @item @code{package} (default: @code{isc-dhcp})
14094 The package that provides the DHCP daemon. This package is expected to
14095 provide the daemon at @file{sbin/dhcpd} relative to its output
14096 directory. The default package is the
14097 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
14098 @item @code{config-file} (default: @code{#f})
14099 The configuration file to use. This is required. It will be passed to
14100 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
14101 object (@pxref{G-Expressions, file-like objects}). See @code{man
14102 dhcpd.conf} for details on the configuration file syntax.
14103 @item @code{version} (default: @code{"4"})
14104 The DHCP version to use. The ISC DHCP server supports the values ``4'',
14105 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
14106 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
14108 @item @code{run-directory} (default: @code{"/run/dhcpd"})
14109 The run directory to use. At service activation time, this directory
14110 will be created if it does not exist.
14111 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
14112 The PID file to use. This corresponds to the @code{-pf} option of
14113 @code{dhcpd}. See @code{man dhcpd} for details.
14114 @item @code{interfaces} (default: @code{'()})
14115 The names of the network interfaces on which dhcpd should listen for
14116 broadcasts. If this list is not empty, then its elements (which must be
14117 strings) will be appended to the @code{dhcpd} invocation when starting
14118 the daemon. It may not be necessary to explicitly specify any
14119 interfaces here; see @code{man dhcpd} for details.
14123 @defvr {Scheme Variable} static-networking-service-type
14124 This is the type for statically-configured network interfaces.
14125 @c TODO Document <static-networking> data structures.
14128 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
14129 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
14130 [#:requirement @code{'(udev)}]
14131 Return a service that starts @var{interface} with address @var{ip}. If
14132 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
14133 it must be a string specifying the default network gateway. @var{requirement}
14134 can be used to declare a dependency on another service before configuring the
14137 This procedure can be called several times, one for each network
14138 interface of interest. Behind the scenes what it does is extend
14139 @code{static-networking-service-type} with additional network interfaces
14145 (static-networking-service "eno1" "192.168.1.82"
14146 #:gateway "192.168.1.2"
14147 #:name-servers '("192.168.1.2"))
14154 @cindex network management
14155 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
14156 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
14157 management daemon that aims to simplify wired and wireless networking.
14159 This service adds the @var{wicd} package to the global profile, providing
14160 several commands to interact with the daemon and configure networking:
14161 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
14162 and @command{wicd-curses} user interfaces.
14165 @cindex ModemManager
14167 @defvr {Scheme Variable} modem-manager-service-type
14168 This is the service type for the
14169 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
14170 service. The value for this service type is a
14171 @code{modem-manager-configuration} record.
14173 This service is part of @code{%desktop-services} (@pxref{Desktop
14177 @deftp {Data Type} modem-manager-configuration
14178 Data type representing the configuration of ModemManager.
14181 @item @code{modem-manager} (default: @code{modem-manager})
14182 The ModemManager package to use.
14187 @cindex USB_ModeSwitch
14188 @cindex Modeswitching
14190 @defvr {Scheme Variable} usb-modeswitch-service-type
14191 This is the service type for the
14192 @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch} service. The
14193 value for this service type is a @code{usb-modeswitch-configuration} record.
14195 When plugged in, some USB modems (and other USB devices) initially present
14196 themselves as a read-only storage medium and not as a modem. They need to be
14197 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
14198 installs udev rules to automatically modeswitch these devices when they are
14201 This service is part of @code{%desktop-services} (@pxref{Desktop
14205 @deftp {Data Type} usb-modeswitch-configuration
14206 Data type representing the configuration of USB_ModeSwitch.
14209 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
14210 The USB_ModeSwitch package providing the binaries for modeswitching.
14212 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
14213 The package providing the device data and udev rules file used by
14216 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
14217 Which config file to use for the USB_ModeSwitch dispatcher. By default the
14218 config file shipped with USB_ModeSwitch is used which disables logging to
14219 @file{/var/log} among other default settings. If set to @code{#f}, no config
14225 @cindex NetworkManager
14227 @defvr {Scheme Variable} network-manager-service-type
14228 This is the service type for the
14229 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
14230 service. The value for this service type is a
14231 @code{network-manager-configuration} record.
14233 This service is part of @code{%desktop-services} (@pxref{Desktop
14237 @deftp {Data Type} network-manager-configuration
14238 Data type representing the configuration of NetworkManager.
14241 @item @code{network-manager} (default: @code{network-manager})
14242 The NetworkManager package to use.
14244 @item @code{dns} (default: @code{"default"})
14245 Processing mode for DNS, which affects how NetworkManager uses the
14246 @code{resolv.conf} configuration file.
14250 NetworkManager will update @code{resolv.conf} to reflect the nameservers
14251 provided by currently active connections.
14254 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
14255 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
14256 then update @code{resolv.conf} to point to the local nameserver.
14258 With this setting, you can share your network connection. For example when
14259 you want to share your network connection to another laptop @i{via} an
14260 Ethernet cable, you can open @command{nm-connection-editor} and configure the
14261 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
14262 and reestablish the connection (or reboot).
14264 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
14265 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
14266 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
14267 browser on your host system, or connect to the VM @i{via} SSH
14268 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
14269 host-to-guest connection, run this command once:
14272 nmcli connection add type tun \
14273 connection.interface-name tap0 \
14274 tun.mode tap tun.owner $(id -u) \
14275 ipv4.method shared \
14276 ipv4.addresses 172.28.112.1/24
14279 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
14280 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
14281 @command{qemu-system-...}.
14284 NetworkManager will not modify @code{resolv.conf}.
14287 @item @code{vpn-plugins} (default: @code{'()})
14288 This is the list of available plugins for virtual private networks
14289 (VPNs). An example of this is the @code{network-manager-openvpn}
14290 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
14296 @deffn {Scheme Variable} connman-service-type
14297 This is the service type to run @url{https://01.org/connman,Connman},
14298 a network connection manager.
14300 Its value must be an
14301 @code{connman-configuration} record as in this example:
14304 (service connman-service-type
14305 (connman-configuration
14306 (disable-vpn? #t)))
14309 See below for details about @code{connman-configuration}.
14312 @deftp {Data Type} connman-configuration
14313 Data Type representing the configuration of connman.
14316 @item @code{connman} (default: @var{connman})
14317 The connman package to use.
14319 @item @code{disable-vpn?} (default: @code{#f})
14320 When true, disable connman's vpn plugin.
14324 @cindex WPA Supplicant
14325 @defvr {Scheme Variable} wpa-supplicant-service-type
14326 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
14327 supplicant}, an authentication daemon required to authenticate against
14328 encrypted WiFi or ethernet networks.
14331 @deftp {Data Type} wpa-supplicant-configuration
14332 Data type representing the configuration of WPA Supplicant.
14334 It takes the following parameters:
14337 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
14338 The WPA Supplicant package to use.
14340 @item @code{requirement} (default: @code{'(user-processes dbus-system loopback syslogd)}
14341 List of services that should be started before WPA Supplicant starts.
14343 @item @code{dbus?} (default: @code{#t})
14344 Whether to listen for requests on D-Bus.
14346 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
14347 Where to store the PID file.
14349 @item @code{interface} (default: @code{#f})
14350 If this is set, it must specify the name of a network interface that
14351 WPA supplicant will control.
14353 @item @code{config-file} (default: @code{#f})
14354 Optional configuration file to use.
14356 @item @code{extra-options} (default: @code{'()})
14357 List of additional command-line arguments to pass to the daemon.
14361 @cindex hostapd service, for Wi-Fi access points
14362 @cindex Wi-Fi access points, hostapd service
14363 @defvr {Scheme Variable} hostapd-service-type
14364 This is the service type to run the @uref{https://w1.fi/hostapd/,
14365 hostapd} daemon to set up WiFi (IEEE 802.11) access points and
14366 authentication servers. Its associated value must be a
14367 @code{hostapd-configuration} as shown below:
14370 ;; Use wlan1 to run the access point for "My Network".
14371 (service hostapd-service-type
14372 (hostapd-configuration
14373 (interface "wlan1")
14374 (ssid "My Network")
14379 @deftp {Data Type} hostapd-configuration
14380 This data type represents the configuration of the hostapd service, with
14381 the following fields:
14384 @item @code{package} (default: @code{hostapd})
14385 The hostapd package to use.
14387 @item @code{interface} (default: @code{"wlan0"})
14388 The network interface to run the WiFi access point.
14391 The SSID (@dfn{service set identifier}), a string that identifies this
14394 @item @code{broadcast-ssid?} (default: @code{#t})
14395 Whether to broadcast this SSID.
14397 @item @code{channel} (default: @code{1})
14398 The WiFi channel to use.
14400 @item @code{driver} (default: @code{"nl80211"})
14401 The driver interface type. @code{"nl80211"} is used with all Linux
14402 mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
14403 RADIUS server that does # not control any wireless/wired driver.
14405 @item @code{extra-settings} (default: @code{""})
14406 Extra settings to append as-is to the hostapd configuration file. See
14407 @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
14408 configuration file reference.
14412 @defvr {Scheme Variable} simulated-wifi-service-type
14413 This is the type of a service to simulate WiFi networking, which can be
14414 useful in virtual machines for testing purposes. The service loads the
14416 @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
14417 @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
14418 network that can be seen on @code{wlan0}, by default.
14420 The service's value is a @code{hostapd-configuration} record.
14424 @defvr {Scheme Variable} iptables-service-type
14425 This is the service type to set up an iptables configuration. iptables is a
14426 packet filtering framework supported by the Linux kernel. This service
14427 supports configuring iptables for both IPv4 and IPv6. A simple example
14428 configuration rejecting all incoming connections except those to the ssh port
14432 (service iptables-service-type
14433 (iptables-configuration
14434 (ipv4-rules (plain-file "iptables.rules" "*filter
14438 -A INPUT -p tcp --dport 22 -j ACCEPT
14439 -A INPUT -j REJECT --reject-with icmp-port-unreachable
14442 (ipv6-rules (plain-file "ip6tables.rules" "*filter
14446 -A INPUT -p tcp --dport 22 -j ACCEPT
14447 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
14453 @deftp {Data Type} iptables-configuration
14454 The data type representing the configuration of iptables.
14457 @item @code{iptables} (default: @code{iptables})
14458 The iptables package that provides @code{iptables-restore} and
14459 @code{ip6tables-restore}.
14460 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
14461 The iptables rules to use. It will be passed to @code{iptables-restore}.
14462 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
14464 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
14465 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
14466 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
14472 @defvr {Scheme Variable} nftables-service-type
14473 This is the service type to set up a nftables configuration. nftables is a
14474 netfilter project that aims to replace the existing iptables, ip6tables,
14475 arptables and ebtables framework. It provides a new packet filtering
14476 framework, a new user-space utility @command{nft}, and a compatibility layer
14477 for iptables. This service comes with a default ruleset
14478 @code{%default-nftables-ruleset} that rejecting all incomming connections
14479 except those to the ssh port 22. To use it, simply write:
14482 (service nftables-service-type)
14486 @deftp {Data Type} nftables-configuration
14487 The data type representing the configuration of nftables.
14490 @item @code{package} (default: @code{nftables})
14491 The nftables package that provides @command{nft}.
14492 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
14493 The nftables ruleset to use. This may be any ``file-like'' object
14494 (@pxref{G-Expressions, file-like objects}).
14498 @cindex NTP (Network Time Protocol), service
14499 @cindex ntpd, service for the Network Time Protocol daemon
14500 @cindex real time clock
14501 @defvr {Scheme Variable} ntp-service-type
14502 This is the type of the service running the @uref{https://www.ntp.org,
14503 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
14504 system clock synchronized with that of the specified NTP servers.
14506 The value of this service is an @code{ntpd-configuration} object, as described
14510 @deftp {Data Type} ntp-configuration
14511 This is the data type for the NTP service configuration.
14514 @item @code{servers} (default: @code{%ntp-servers})
14515 This is the list of servers (@code{<ntp-server>} records) with which
14516 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
14519 @item @code{allow-large-adjustment?} (default: @code{#t})
14520 This determines whether @command{ntpd} is allowed to make an initial
14521 adjustment of more than 1,000 seconds.
14523 @item @code{ntp} (default: @code{ntp})
14524 The NTP package to use.
14528 @defvr {Scheme Variable} %ntp-servers
14529 List of host names used as the default NTP servers. These are servers of the
14530 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
14533 @deftp {Data Type} ntp-server
14534 The data type representing the configuration of a NTP server.
14537 @item @code{type} (default: @code{'server})
14538 The type of the NTP server, given as a symbol. One of @code{'pool},
14539 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
14541 @item @code{address}
14542 The address of the server, as a string.
14544 @item @code{options}
14545 NTPD options to use with that specific server, given as a list of option names
14546 and/or of option names and values tuples. The following example define a server
14547 to use with the options @option{iburst} and @option{prefer}, as well as
14548 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
14553 (address "some.ntp.server.org")
14554 (options `(iburst (version 3) (maxpoll 16) prefer))))
14560 @deffn {Scheme Procedure} openntpd-service-type
14561 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
14562 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
14563 clock synchronized with that of the given servers.
14567 openntpd-service-type
14568 (openntpd-configuration
14569 (listen-on '("127.0.0.1" "::1"))
14570 (sensor '("udcf0 correction 70000"))
14571 (constraint-from '("www.gnu.org"))
14572 (constraints-from '("https://www.google.com/"))
14573 (allow-large-adjustment? #t)))
14578 @defvr {Scheme Variable} %openntpd-servers
14579 This variable is a list of the server addresses defined in
14580 @code{%ntp-servers}.
14583 @deftp {Data Type} openntpd-configuration
14585 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
14586 The openntpd executable to use.
14587 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
14588 A list of local IP addresses or hostnames the ntpd daemon should listen on.
14589 @item @code{query-from} (default: @code{'()})
14590 A list of local IP address the ntpd daemon should use for outgoing queries.
14591 @item @code{sensor} (default: @code{'()})
14592 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
14593 will listen to each sensor that actually exists and ignore non-existent ones.
14594 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
14596 @item @code{server} (default: @code{'()})
14597 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
14598 @item @code{servers} (default: @code{%openntp-servers})
14599 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
14600 @item @code{constraint-from} (default: @code{'()})
14601 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
14602 This time information is not used for precision but acts as an authenticated
14603 constraint, thereby reducing the impact of unauthenticated NTP
14604 man-in-the-middle attacks.
14605 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
14607 @item @code{constraints-from} (default: @code{'()})
14608 As with constraint from, specify a list of URLs, IP addresses or hostnames of
14609 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
14610 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
14611 @item @code{allow-large-adjustment?} (default: @code{#f})
14612 Determines if @code{ntpd} is allowed to make an initial adjustment of more
14618 @deffn {Scheme variable} inetd-service-type
14619 This service runs the @command{inetd} (@pxref{inetd invocation,,,
14620 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
14621 connections on internet sockets, and lazily starts the specified server
14622 program when a connection is made on one of these sockets.
14624 The value of this service is an @code{inetd-configuration} object. The
14625 following example configures the @command{inetd} daemon to provide the
14626 built-in @command{echo} service, as well as an smtp service which
14627 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
14628 gateway @code{hostname}:
14633 (inetd-configuration
14637 (socket-type 'stream)
14644 (socket-type 'stream)
14648 (program (file-append openssh "/bin/ssh"))
14650 '("ssh" "-qT" "-i" "/path/to/ssh_key"
14651 "-W" "smtp-server:25" "user@@hostname")))))))
14654 See below for more details about @code{inetd-configuration}.
14657 @deftp {Data Type} inetd-configuration
14658 Data type representing the configuration of @command{inetd}.
14661 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
14662 The @command{inetd} executable to use.
14664 @item @code{entries} (default: @code{'()})
14665 A list of @command{inetd} service entries. Each entry should be created
14666 by the @code{inetd-entry} constructor.
14670 @deftp {Data Type} inetd-entry
14671 Data type representing an entry in the @command{inetd} configuration.
14672 Each entry corresponds to a socket where @command{inetd} will listen for
14676 @item @code{node} (default: @code{#f})
14677 Optional string, a comma-separated list of local addresses
14678 @command{inetd} should use when listening for this service.
14679 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
14680 description of all options.
14682 A string, the name must correspond to an entry in @code{/etc/services}.
14683 @item @code{socket-type}
14684 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
14686 @item @code{protocol}
14687 A string, must correspond to an entry in @code{/etc/protocols}.
14688 @item @code{wait?} (default: @code{#t})
14689 Whether @command{inetd} should wait for the server to exit before
14690 listening to new service requests.
14692 A string containing the user (and, optionally, group) name of the user
14693 as whom the server should run. The group name can be specified in a
14694 suffix, separated by a colon or period, i.e.@: @code{"user"},
14695 @code{"user:group"} or @code{"user.group"}.
14696 @item @code{program} (default: @code{"internal"})
14697 The server program which will serve the requests, or @code{"internal"}
14698 if @command{inetd} should use a built-in service.
14699 @item @code{arguments} (default: @code{'()})
14700 A list strings or file-like objects, which are the server program's
14701 arguments, starting with the zeroth argument, i.e.@: the name of the
14702 program itself. For @command{inetd}'s internal services, this entry
14703 must be @code{'()} or @code{'("internal")}.
14706 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
14707 detailed discussion of each configuration field.
14711 @defvr {Scheme Variable} tor-service-type
14712 This is the type for a service that runs the @uref{https://torproject.org,
14713 Tor} anonymous networking daemon. The service is configured using a
14714 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
14715 @code{tor} unprivileged user, which is a member of the @code{tor} group.
14719 @deftp {Data Type} tor-configuration
14721 @item @code{tor} (default: @code{tor})
14722 The package that provides the Tor daemon. This package is expected to provide
14723 the daemon at @file{bin/tor} relative to its output directory. The default
14724 package is the @uref{https://www.torproject.org, Tor Project's}
14727 @item @code{config-file} (default: @code{(plain-file "empty" "")})
14728 The configuration file to use. It will be appended to a default configuration
14729 file, and the final configuration file will be passed to @code{tor} via its
14730 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
14731 file-like objects}). See @code{man tor} for details on the configuration file
14734 @item @code{hidden-services} (default: @code{'()})
14735 The list of @code{<hidden-service>} records to use. For any hidden service
14736 you include in this list, appropriate configuration to enable the hidden
14737 service will be automatically added to the default configuration file. You
14738 may conveniently create @code{<hidden-service>} records using the
14739 @code{tor-hidden-service} procedure described below.
14741 @item @code{socks-socket-type} (default: @code{'tcp})
14742 The default socket type that Tor should use for its SOCKS socket. This must
14743 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
14744 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
14745 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
14746 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
14749 If you want to customize the SOCKS socket in more detail, leave
14750 @code{socks-socket-type} at its default value of @code{'tcp} and use
14751 @code{config-file} to override the default by providing your own
14752 @code{SocksPort} option.
14756 @cindex hidden service
14757 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
14758 Define a new Tor @dfn{hidden service} called @var{name} and implementing
14759 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
14762 '((22 "127.0.0.1:22")
14763 (80 "127.0.0.1:8080"))
14766 In this example, port 22 of the hidden service is mapped to local port 22, and
14767 port 80 is mapped to local port 8080.
14769 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
14770 the @file{hostname} file contains the @code{.onion} host name for the hidden
14773 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
14774 project's documentation} for more information.
14777 The @code{(gnu services rsync)} module provides the following services:
14779 You might want an rsync daemon if you have files that you want available
14780 so anyone (or just yourself) can download existing files or upload new
14783 @deffn {Scheme Variable} rsync-service-type
14784 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
14785 The value for this service type is a
14786 @command{rsync-configuration} record as in this example:
14789 (service rsync-service-type)
14792 See below for details about @code{rsync-configuration}.
14795 @deftp {Data Type} rsync-configuration
14796 Data type representing the configuration for @code{rsync-service}.
14799 @item @code{package} (default: @var{rsync})
14800 @code{rsync} package to use.
14802 @item @code{port-number} (default: @code{873})
14803 TCP port on which @command{rsync} listens for incoming connections. If port
14804 is less than @code{1024} @command{rsync} needs to be started as the
14805 @code{root} user and group.
14807 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
14808 Name of the file where @command{rsync} writes its PID.
14810 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
14811 Name of the file where @command{rsync} writes its lock file.
14813 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
14814 Name of the file where @command{rsync} writes its log file.
14816 @item @code{use-chroot?} (default: @var{#t})
14817 Whether to use chroot for @command{rsync} shared directory.
14819 @item @code{share-path} (default: @file{/srv/rsync})
14820 Location of the @command{rsync} shared directory.
14822 @item @code{share-comment} (default: @code{"Rsync share"})
14823 Comment of the @command{rsync} shared directory.
14825 @item @code{read-only?} (default: @var{#f})
14826 Read-write permissions to shared directory.
14828 @item @code{timeout} (default: @code{300})
14829 I/O timeout in seconds.
14831 @item @code{user} (default: @var{"root"})
14832 Owner of the @code{rsync} process.
14834 @item @code{group} (default: @var{"root"})
14835 Group of the @code{rsync} process.
14837 @item @code{uid} (default: @var{"rsyncd"})
14838 User name or user ID that file transfers to and from that module should take
14839 place as when the daemon was run as @code{root}.
14841 @item @code{gid} (default: @var{"rsyncd"})
14842 Group name or group ID that will be used when accessing the module.
14847 Furthermore, @code{(gnu services ssh)} provides the following services.
14851 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
14852 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
14853 [#:allow-empty-passwords? #f] [#:root-login? #f] @
14854 [#:syslog-output? #t] [#:x11-forwarding? #t] @
14855 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
14856 [#:public-key-authentication? #t] [#:initialize? #t]
14857 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
14858 @var{host-key} must designate a file containing the host key, and readable
14861 When @var{daemonic?} is true, @command{lshd} will detach from the
14862 controlling terminal and log its output to syslogd, unless one sets
14863 @var{syslog-output?} to false. Obviously, it also makes lsh-service
14864 depend on existence of syslogd service. When @var{pid-file?} is true,
14865 @command{lshd} writes its PID to the file called @var{pid-file}.
14867 When @var{initialize?} is true, automatically create the seed and host key
14868 upon service activation if they do not exist yet. This may take long and
14869 require interaction.
14871 When @var{initialize?} is false, it is up to the user to initialize the
14872 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
14873 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
14874 basics,,, lsh, LSH Manual}).
14876 When @var{interfaces} is empty, lshd listens for connections on all the
14877 network interfaces; otherwise, @var{interfaces} must be a list of host names
14880 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
14881 passwords, and @var{root-login?} specifies whether to accept log-ins as
14884 The other options should be self-descriptive.
14889 @deffn {Scheme Variable} openssh-service-type
14890 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
14891 shell daemon, @command{sshd}. Its value must be an
14892 @code{openssh-configuration} record as in this example:
14895 (service openssh-service-type
14896 (openssh-configuration
14897 (x11-forwarding? #t)
14898 (permit-root-login 'without-password)
14900 `(("alice" ,(local-file "alice.pub"))
14901 ("bob" ,(local-file "bob.pub"))))))
14904 See below for details about @code{openssh-configuration}.
14906 This service can be extended with extra authorized keys, as in this
14910 (service-extension openssh-service-type
14911 (const `(("charlie"
14912 ,(local-file "charlie.pub")))))
14916 @deftp {Data Type} openssh-configuration
14917 This is the configuration record for OpenSSH's @command{sshd}.
14920 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
14921 Name of the file where @command{sshd} writes its PID.
14923 @item @code{port-number} (default: @code{22})
14924 TCP port on which @command{sshd} listens for incoming connections.
14926 @item @code{permit-root-login} (default: @code{#f})
14927 This field determines whether and when to allow logins as root. If
14928 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
14929 If it's the symbol @code{'without-password}, then root logins are
14930 permitted but not with password-based authentication.
14932 @item @code{allow-empty-passwords?} (default: @code{#f})
14933 When true, users with empty passwords may log in. When false, they may
14936 @item @code{password-authentication?} (default: @code{#t})
14937 When true, users may log in with their password. When false, they have
14938 other authentication methods.
14940 @item @code{public-key-authentication?} (default: @code{#t})
14941 When true, users may log in using public key authentication. When
14942 false, users have to use other authentication method.
14944 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
14945 This is used only by protocol version 2.
14947 @item @code{x11-forwarding?} (default: @code{#f})
14948 When true, forwarding of X11 graphical client connections is
14949 enabled---in other words, @command{ssh} options @option{-X} and
14950 @option{-Y} will work.
14952 @item @code{allow-agent-forwarding?} (default: @code{#t})
14953 Whether to allow agent forwarding.
14955 @item @code{allow-tcp-forwarding?} (default: @code{#t})
14956 Whether to allow TCP forwarding.
14958 @item @code{gateway-ports?} (default: @code{#f})
14959 Whether to allow gateway ports.
14961 @item @code{challenge-response-authentication?} (default: @code{#f})
14962 Specifies whether challenge response authentication is allowed (e.g.@: via
14965 @item @code{use-pam?} (default: @code{#t})
14966 Enables the Pluggable Authentication Module interface. If set to
14967 @code{#t}, this will enable PAM authentication using
14968 @code{challenge-response-authentication?} and
14969 @code{password-authentication?}, in addition to PAM account and session
14970 module processing for all authentication types.
14972 Because PAM challenge response authentication usually serves an
14973 equivalent role to password authentication, you should disable either
14974 @code{challenge-response-authentication?} or
14975 @code{password-authentication?}.
14977 @item @code{print-last-log?} (default: @code{#t})
14978 Specifies whether @command{sshd} should print the date and time of the
14979 last user login when a user logs in interactively.
14981 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
14982 Configures external subsystems (e.g.@: file transfer daemon).
14984 This is a list of two-element lists, each of which containing the
14985 subsystem name and a command (with optional arguments) to execute upon
14988 The command @command{internal-sftp} implements an in-process SFTP
14989 server. Alternatively, one can specify the @command{sftp-server} command:
14991 (service openssh-service-type
14992 (openssh-configuration
14994 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
14997 @item @code{accepted-environment} (default: @code{'()})
14998 List of strings describing which environment variables may be exported.
15000 Each string gets on its own line. See the @code{AcceptEnv} option in
15001 @code{man sshd_config}.
15003 This example allows ssh-clients to export the @env{COLORTERM} variable.
15004 It is set by terminal emulators, which support colors. You can use it in
15005 your shell's resource file to enable colors for the prompt and commands
15006 if this variable is set.
15009 (service openssh-service-type
15010 (openssh-configuration
15011 (accepted-environment '("COLORTERM"))))
15014 @item @code{authorized-keys} (default: @code{'()})
15015 @cindex authorized keys, SSH
15016 @cindex SSH authorized keys
15017 This is the list of authorized keys. Each element of the list is a user
15018 name followed by one or more file-like objects that represent SSH public
15022 (openssh-configuration
15024 `(("rekado" ,(local-file "rekado.pub"))
15025 ("chris" ,(local-file "chris.pub"))
15026 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
15030 registers the specified public keys for user accounts @code{rekado},
15031 @code{chris}, and @code{root}.
15033 Additional authorized keys can be specified @i{via}
15034 @code{service-extension}.
15036 Note that this does @emph{not} interfere with the use of
15037 @file{~/.ssh/authorized_keys}.
15039 @item @code{log-level} (default: @code{'info})
15040 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
15041 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
15042 page for @file{sshd_config} for the full list of level names.
15044 @item @code{extra-content} (default: @code{""})
15045 This field can be used to append arbitrary text to the configuration file. It
15046 is especially useful for elaborate configurations that cannot be expressed
15047 otherwise. This configuration, for example, would generally disable root
15048 logins, but permit them from one specific IP address:
15051 (openssh-configuration
15053 Match Address 192.168.0.1
15054 PermitRootLogin yes"))
15060 @deffn {Scheme Procedure} dropbear-service [@var{config}]
15061 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
15062 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
15065 For example, to specify a Dropbear service listening on port 1234, add
15066 this call to the operating system's @code{services} field:
15069 (dropbear-service (dropbear-configuration
15070 (port-number 1234)))
15074 @deftp {Data Type} dropbear-configuration
15075 This data type represents the configuration of a Dropbear SSH daemon.
15078 @item @code{dropbear} (default: @var{dropbear})
15079 The Dropbear package to use.
15081 @item @code{port-number} (default: 22)
15082 The TCP port where the daemon waits for incoming connections.
15084 @item @code{syslog-output?} (default: @code{#t})
15085 Whether to enable syslog output.
15087 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
15088 File name of the daemon's PID file.
15090 @item @code{root-login?} (default: @code{#f})
15091 Whether to allow @code{root} logins.
15093 @item @code{allow-empty-passwords?} (default: @code{#f})
15094 Whether to allow empty passwords.
15096 @item @code{password-authentication?} (default: @code{#t})
15097 Whether to enable password-based authentication.
15102 @deffn {Scheme Variable} autossh-service-type
15103 This is the type for the @uref{https://www.harding.motd.ca/autossh,
15104 AutoSSH} program that runs a copy of @command{ssh} and monitors it,
15105 restarting it as necessary should it die or stop passing traffic.
15106 AutoSSH can be run manually from the command-line by passing arguments
15107 to the binary @command{autossh} from the package @code{autossh}, but it
15108 can also be run as a Guix service. This latter use case is documented
15111 AutoSSH can be used to forward local traffic to a remote machine using
15112 an SSH tunnel, and it respects the @file{~/.ssh/config} of the user it
15115 For example, to specify a service running autossh as the user
15116 @code{pino} and forwarding all local connections to port @code{8081} to
15117 @code{remote:8081} using an SSH tunnel, add this call to the operating
15118 system's @code{services} field:
15121 (service autossh-service-type
15122 (autossh-configuration
15124 (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
15128 @deftp {Data Type} autossh-configuration
15129 This data type represents the configuration of an AutoSSH service.
15133 @item @code{user} (default @code{"autossh"})
15134 The user as which the AutoSSH service is to be run.
15135 This assumes that the specified user exists.
15137 @item @code{poll} (default @code{600})
15138 Specifies the connection poll time in seconds.
15140 @item @code{first-poll} (default @code{#f})
15141 Specifies how many seconds AutoSSH waits before the first connection
15142 test. After this first test, polling is resumed at the pace defined in
15143 @code{poll}. When set to @code{#f}, the first poll is not treated
15144 specially and will also use the connection poll specified in
15147 @item @code{gate-time} (default @code{30})
15148 Specifies how many seconds an SSH connection must be active before it is
15149 considered successful.
15151 @item @code{log-level} (default @code{1})
15152 The log level, corresponding to the levels used by syslog---so @code{0}
15153 is the most silent while @code{7} is the chattiest.
15155 @item @code{max-start} (default @code{#f})
15156 The maximum number of times SSH may be (re)started before AutoSSH exits.
15157 When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
15159 @item @code{message} (default @code{""})
15160 The message to append to the echo message sent when testing connections.
15162 @item @code{port} (default @code{"0"})
15163 The ports used for monitoring the connection. When set to @code{"0"},
15164 monitoring is disabled. When set to @code{"@var{n}"} where @var{n} is
15165 a positive integer, ports @var{n} and @var{n}+1 are used for
15166 monitoring the connection, such that port @var{n} is the base
15167 monitoring port and @code{n+1} is the echo port. When set to
15168 @code{"@var{n}:@var{m}"} where @var{n} and @var{m} are positive
15169 integers, the ports @var{n} and @var{m} are used for monitoring the
15170 connection, such that port @var{n} is the base monitoring port and
15171 @var{m} is the echo port.
15173 @item @code{ssh-options} (default @code{'()})
15174 The list of command-line arguments to pass to @command{ssh} when it is
15175 run. Options @option{-f} and @option{-M} are reserved for AutoSSH and
15176 may cause undefined behaviour.
15181 @defvr {Scheme Variable} %facebook-host-aliases
15182 This variable contains a string for use in @file{/etc/hosts}
15183 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
15184 line contains a entry that maps a known server name of the Facebook
15185 on-line service---e.g., @code{www.facebook.com}---to the local
15186 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
15188 This variable is typically used in the @code{hosts-file} field of an
15189 @code{operating-system} declaration (@pxref{operating-system Reference,
15190 @file{/etc/hosts}}):
15193 (use-modules (gnu) (guix))
15196 (host-name "mymachine")
15199 ;; Create a /etc/hosts file with aliases for "localhost"
15200 ;; and "mymachine", as well as for Facebook servers.
15201 (plain-file "hosts"
15202 (string-append (local-host-aliases host-name)
15203 %facebook-host-aliases))))
15206 This mechanism can prevent programs running locally, such as Web
15207 browsers, from accessing Facebook.
15210 The @code{(gnu services avahi)} provides the following definition.
15212 @defvr {Scheme Variable} avahi-service-type
15213 This is the service that runs @command{avahi-daemon}, a system-wide
15214 mDNS/DNS-SD responder that allows for service discovery and
15215 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
15216 Its value must be a @code{zero-configuration} record---see below.
15218 This service extends the name service cache daemon (nscd) so that it can
15219 resolve @code{.local} host names using
15220 @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
15221 Service Switch}, for information on host name resolution.
15223 Additionally, add the @var{avahi} package to the system profile so that
15224 commands such as @command{avahi-browse} are directly usable.
15227 @deftp {Data Type} avahi-configuration
15228 Data type representation the configuration for Avahi.
15232 @item @code{host-name} (default: @code{#f})
15233 If different from @code{#f}, use that as the host name to
15234 publish for this machine; otherwise, use the machine's actual host name.
15236 @item @code{publish?} (default: @code{#t})
15237 When true, allow host names and services to be published (broadcast) over the
15240 @item @code{publish-workstation?} (default: @code{#t})
15241 When true, @command{avahi-daemon} publishes the machine's host name and IP
15242 address via mDNS on the local network. To view the host names published on
15243 your local network, you can run:
15246 avahi-browse _workstation._tcp
15249 @item @code{wide-area?} (default: @code{#f})
15250 When true, DNS-SD over unicast DNS is enabled.
15252 @item @code{ipv4?} (default: @code{#t})
15253 @itemx @code{ipv6?} (default: @code{#t})
15254 These fields determine whether to use IPv4/IPv6 sockets.
15256 @item @code{domains-to-browse} (default: @code{'()})
15257 This is a list of domains to browse.
15261 @deffn {Scheme Variable} openvswitch-service-type
15262 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
15263 service, whose value should be an @code{openvswitch-configuration}
15267 @deftp {Data Type} openvswitch-configuration
15268 Data type representing the configuration of Open vSwitch, a multilayer
15269 virtual switch which is designed to enable massive network automation
15270 through programmatic extension.
15273 @item @code{package} (default: @var{openvswitch})
15274 Package object of the Open vSwitch.
15279 @defvr {Scheme Variable} pagekite-service-type
15280 This is the service type for the @uref{https://pagekite.net, PageKite} service,
15281 a tunneling solution for making localhost servers publicly visible, even from
15282 behind restrictive firewalls or NAT without forwarded ports. The value for
15283 this service type is a @code{pagekite-configuration} record.
15285 Here's an example exposing the local HTTP and SSH daemons:
15288 (service pagekite-service-type
15289 (pagekite-configuration
15290 (kites '("http:@@kitename:localhost:80:@@kitesecret"
15291 "raw/22:@@kitename:localhost:22:@@kitesecret"))
15292 (extra-file "/etc/pagekite.rc")))
15296 @deftp {Data Type} pagekite-configuration
15297 Data type representing the configuration of PageKite.
15300 @item @code{package} (default: @var{pagekite})
15301 Package object of PageKite.
15303 @item @code{kitename} (default: @code{#f})
15304 PageKite name for authenticating to the frontend server.
15306 @item @code{kitesecret} (default: @code{#f})
15307 Shared secret for authenticating to the frontend server. You should probably
15308 put this inside @code{extra-file} instead.
15310 @item @code{frontend} (default: @code{#f})
15311 Connect to the named PageKite frontend server instead of the
15312 @uref{https://pagekite.net,,pagekite.net} service.
15314 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
15315 List of service kites to use. Exposes HTTP on port 80 by default. The format
15316 is @code{proto:kitename:host:port:secret}.
15318 @item @code{extra-file} (default: @code{#f})
15319 Extra configuration file to read, which you are expected to create manually.
15320 Use this to add additional options and manage shared secrets out-of-band.
15325 @node Unattended Upgrades
15326 @subsection Unattended Upgrades
15328 @cindex unattended upgrades
15329 @cindex upgrades, unattended
15330 Guix provides a service to perform @emph{unattended upgrades}:
15331 periodically, the system automatically reconfigures itself from the
15332 latest Guix. Guix System has several properties that make unattended
15337 upgrades are transactional (either the upgrade succeeds or it fails, but
15338 you cannot end up with an ``in-between'' system state);
15340 the upgrade log is kept---you can view it with @command{guix system
15341 list-generations}---and you can roll back to any previous generation,
15342 should the upgraded system fail to behave as intended;
15344 channel code is authenticated so you know you can only run genuine code
15345 (@pxref{Channels});
15347 @command{guix system reconfigure} prevents downgrades, which makes it
15348 immune to @dfn{downgrade attacks}.
15351 To set up unattended upgrades, add an instance of
15352 @code{unattended-upgrade-service-type} like the one below to the list of
15353 your operating system services:
15356 (service unattended-upgrade-service-type)
15359 The defaults above set up weekly upgrades: every Sunday at midnight.
15360 You do not need to provide the operating system configuration file: it
15361 uses @file{/run/current-system/configuration.scm}, which ensures it
15362 always uses your latest configuration---@pxref{provenance-service-type},
15363 for more information about this file.
15365 There are several things that can be configured, in particular the
15366 periodicity and services (daemons) to be restarted upon completion.
15367 When the upgrade is successful, the service takes care of deleting
15368 system generations older that some threshold, as per @command{guix
15369 system delete-generations}. See the reference below for details.
15371 To ensure that upgrades are actually happening, you can run
15372 @command{guix system describe}. To investigate upgrade failures, visit
15373 the unattended upgrade log file (see below).
15375 @defvr {Scheme Variable} unattended-upgrade-service-type
15376 This is the service type for unattended upgrades. It sets up an mcron
15377 job (@pxref{Scheduled Job Execution}) that runs @command{guix system
15378 reconfigure} from the latest version of the specified channels.
15380 Its value must be a @code{unattended-upgrade-configuration} record (see
15384 @deftp {Data Type} unattended-upgrade-configuration
15385 This data type represents the configuration of the unattended upgrade
15386 service. The following fields are available:
15389 @item @code{schedule} (default: @code{"30 01 * * 0"})
15390 This is the schedule of upgrades, expressed as a gexp containing an
15391 mcron job schedule (@pxref{Guile Syntax, mcron job specifications,,
15392 mcron, GNU@tie{}mcron}).
15394 @item @code{channels} (default: @code{#~%default-channels})
15395 This gexp specifies the channels to use for the upgrade
15396 (@pxref{Channels}). By default, the tip of the official @code{guix}
15399 @item @code{operating-system-file} (default: @code{"/run/current-system/configuration.scm"})
15400 This field specifies the operating system configuration file to use.
15401 The default is to reuse the config file of the current configuration.
15403 There are cases, though, where referring to
15404 @file{/run/current-system/configuration.scm} is not enough, for instance
15405 because that file refers to extra files (SSH public keys, extra
15406 configuration files, etc.) @i{via} @code{local-file} and similar
15407 constructs. For those cases, we recommend something along these lines:
15410 (unattended-upgrade-configuration
15411 (operating-system-file
15412 (file-append (local-file "." "config-dir" #:recursive? #t)
15416 The effect here is to import all of the current directory into the
15417 store, and to refer to @file{config.scm} within that directory.
15418 Therefore, uses of @code{local-file} within @file{config.scm} will work
15419 as expected. @xref{G-Expressions}, for information about
15420 @code{local-file} and @code{file-append}.
15422 @item @code{services-to-restart} (default: @code{'(mcron)})
15423 This field specifies the Shepherd services to restart when the upgrade
15426 Those services are restarted right away upon completion, as with
15427 @command{herd restart}, which ensures that the latest version is
15428 running---remember that by default @command{guix system reconfigure}
15429 only restarts services that are not currently running, which is
15430 conservative: it minimizes disruption but leaves outdated services
15433 By default, the @code{mcron} service is restarted. This ensures that
15434 the latest version of the unattended upgrade job will be used next time.
15436 @item @code{system-expiration} (default: @code{(* 3 30 24 3600)})
15437 This is the expiration time in seconds for system generations. System
15438 generations older that this amount of time are deleted with
15439 @command{guix system delete-generations} when an upgrade completes.
15442 The unattended upgrade service does not run the garbage collector. You
15443 will probably want to set up your own mcron job to run @command{guix gc}
15447 @item @code{maximum-duration} (default: @code{3600})
15448 Maximum duration in seconds for the upgrade; past that time, the upgrade
15451 This is primarily useful to ensure the upgrade does not end up
15452 rebuilding or re-downloading ``the world''.
15454 @item @code{log-file} (default: @code{"/var/log/unattended-upgrade.log"})
15455 File where unattended upgrades are logged.
15460 @subsection X Window
15463 @cindex X Window System
15464 @cindex login manager
15465 Support for the X Window graphical display system---specifically
15466 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
15467 there is no @code{xorg-service} procedure. Instead, the X server is
15468 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
15471 @cindex GNOME, login manager
15472 GDM of course allows users to log in into window managers and desktop
15473 environments other than GNOME; for those using GNOME, GDM is required for
15474 features such as automatic screen locking.
15476 @cindex window manager
15477 To use X11, you must install at least one @dfn{window manager}---for
15478 example the @code{windowmaker} or @code{openbox} packages---preferably
15479 by adding it to the @code{packages} field of your operating system
15480 definition (@pxref{operating-system Reference, system-wide packages}).
15482 @defvr {Scheme Variable} gdm-service-type
15483 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
15484 Desktop Manager} (GDM), a program that manages graphical display servers and
15485 handles graphical user logins. Its value must be a @code{gdm-configuration}
15488 @cindex session types (X11)
15489 @cindex X11 session types
15490 GDM looks for @dfn{session types} described by the @file{.desktop} files in
15491 @file{/run/current-system/profile/share/xsessions} and allows users to choose
15492 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
15493 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
15494 set of packages automatically makes them available at the log-in screen.
15496 In addition, @file{~/.xsession} files are honored. When available,
15497 @file{~/.xsession} must be an executable that starts a window manager
15498 and/or other X clients.
15501 @deftp {Data Type} gdm-configuration
15503 @item @code{auto-login?} (default: @code{#f})
15504 @itemx @code{default-user} (default: @code{#f})
15505 When @code{auto-login?} is false, GDM presents a log-in screen.
15507 When @code{auto-login?} is true, GDM logs in directly as
15508 @code{default-user}.
15510 @item @code{debug?} (default: @code{#f})
15511 When true, GDM writes debug messages to its log.
15513 @item @code{gnome-shell-assets} (default: ...)
15514 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
15516 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
15517 Configuration of the Xorg graphical server.
15519 @item @code{xsession} (default: @code{(xinitrc)})
15520 Script to run before starting a X session.
15522 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
15523 File name of the @code{dbus-daemon} executable.
15525 @item @code{gdm} (default: @code{gdm})
15526 The GDM package to use.
15530 @defvr {Scheme Variable} slim-service-type
15531 This is the type for the SLiM graphical login manager for X11.
15533 Like GDM, SLiM looks for session types described by @file{.desktop} files and
15534 allows users to choose a session from the log-in screen using @kbd{F1}. It
15535 also honors @file{~/.xsession} files.
15537 Unlike GDM, SLiM does not spawn the user session on a different VT after
15538 logging in, which means that you can only start one graphical session. If you
15539 want to be able to run multiple graphical sessions at the same time you have
15540 to add multiple SLiM services to your system services. The following example
15541 shows how to replace the default GDM service with two SLiM services on tty7
15545 (use-modules (gnu services)
15546 (gnu services desktop)
15547 (gnu services xorg)
15548 (srfi srfi-1)) ;for 'remove'
15552 (services (cons* (service slim-service-type (slim-configuration
15555 (service slim-service-type (slim-configuration
15558 (remove (lambda (service)
15559 (eq? (service-kind service) gdm-service-type))
15560 %desktop-services))))
15565 @deftp {Data Type} slim-configuration
15566 Data type representing the configuration of @code{slim-service-type}.
15569 @item @code{allow-empty-passwords?} (default: @code{#t})
15570 Whether to allow logins with empty passwords.
15572 @item @code{auto-login?} (default: @code{#f})
15573 @itemx @code{default-user} (default: @code{""})
15574 When @code{auto-login?} is false, SLiM presents a log-in screen.
15576 When @code{auto-login?} is true, SLiM logs in directly as
15577 @code{default-user}.
15579 @item @code{theme} (default: @code{%default-slim-theme})
15580 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
15581 The graphical theme to use and its name.
15583 @item @code{auto-login-session} (default: @code{#f})
15584 If true, this must be the name of the executable to start as the default
15585 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
15587 If false, a session described by one of the available @file{.desktop}
15588 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
15592 You must install at least one window manager in the system profile or in
15593 your user profile. Failing to do that, if @code{auto-login-session} is
15594 false, you will be unable to log in.
15597 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
15598 Configuration of the Xorg graphical server.
15600 @item @code{display} (default @code{":0"})
15601 The display on which to start the Xorg graphical server.
15603 @item @code{vt} (default @code{"vt7"})
15604 The VT on which to start the Xorg graphical server.
15606 @item @code{xauth} (default: @code{xauth})
15607 The XAuth package to use.
15609 @item @code{shepherd} (default: @code{shepherd})
15610 The Shepherd package used when invoking @command{halt} and
15613 @item @code{sessreg} (default: @code{sessreg})
15614 The sessreg package used in order to register the session.
15616 @item @code{slim} (default: @code{slim})
15617 The SLiM package to use.
15621 @defvr {Scheme Variable} %default-theme
15622 @defvrx {Scheme Variable} %default-theme-name
15623 The default SLiM theme and its name.
15627 @deftp {Data Type} sddm-configuration
15628 This is the data type representing the SDDM service configuration.
15631 @item @code{display-server} (default: "x11")
15632 Select display server to use for the greeter. Valid values are
15633 @samp{"x11"} or @samp{"wayland"}.
15635 @item @code{numlock} (default: "on")
15636 Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
15638 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
15639 Command to run when halting.
15641 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
15642 Command to run when rebooting.
15644 @item @code{theme} (default "maldives")
15645 Theme to use. Default themes provided by SDDM are @samp{"elarun"},
15646 @samp{"maldives"} or @samp{"maya"}.
15648 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
15649 Directory to look for themes.
15651 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
15652 Directory to look for faces.
15654 @item @code{default-path} (default "/run/current-system/profile/bin")
15655 Default PATH to use.
15657 @item @code{minimum-uid} (default: 1000)
15658 Minimum UID displayed in SDDM and allowed for log-in.
15660 @item @code{maximum-uid} (default: 2000)
15661 Maximum UID to display in SDDM.
15663 @item @code{remember-last-user?} (default #t)
15664 Remember last user.
15666 @item @code{remember-last-session?} (default #t)
15667 Remember last session.
15669 @item @code{hide-users} (default "")
15670 Usernames to hide from SDDM greeter.
15672 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
15673 Users with shells listed will be hidden from the SDDM greeter.
15675 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
15676 Script to run before starting a wayland session.
15678 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
15679 Directory to look for desktop files starting wayland sessions.
15681 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
15682 Configuration of the Xorg graphical server.
15684 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
15687 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
15690 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
15691 Script to run after starting xorg-server.
15693 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
15694 Script to run before stopping xorg-server.
15696 @item @code{xsession-command} (default: @code{xinitrc})
15697 Script to run before starting a X session.
15699 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
15700 Directory to look for desktop files starting X sessions.
15702 @item @code{minimum-vt} (default: 7)
15705 @item @code{auto-login-user} (default "")
15706 User to use for auto-login.
15708 @item @code{auto-login-session} (default "")
15709 Desktop file to use for auto-login.
15711 @item @code{relogin?} (default #f)
15712 Relogin after logout.
15717 @cindex login manager
15719 @defvr {Scheme Variable} sddm-service-type
15720 This is the type of the service to run the
15721 @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
15722 must be a @code{sddm-configuration} record (see below).
15724 Here's an example use:
15727 (service sddm-service-type
15728 (sddm-configuration
15729 (auto-login-user "alice")
15730 (auto-login-session "xfce.desktop")))
15734 @deftp {Data Type} sddm-configuration
15735 This data type represents the configuration of the SDDM login manager.
15736 The available fields are:
15739 @item @code{sddm} (default: @code{sddm})
15740 The SDDM package to use.
15742 @item @code{display-server} (default: @code{"x11"})
15743 This must be either @code{"x11"} or @code{"wayland"}.
15745 @c FIXME: Add more fields.
15747 @item @code{auto-login-user} (default: @code{""})
15748 If non-empty, this is the user account under which to log in
15751 @item @code{auto-login-session} (default: @code{""})
15752 If non-empty, this is the @file{.desktop} file name to use as the
15753 auto-login session.
15757 @cindex Xorg, configuration
15758 @deftp {Data Type} xorg-configuration
15759 This data type represents the configuration of the Xorg graphical display
15760 server. Note that there is no Xorg service; instead, the X server is started
15761 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
15762 of these display managers aggregates an @code{xorg-configuration} record.
15765 @item @code{modules} (default: @code{%default-xorg-modules})
15766 This is a list of @dfn{module packages} loaded by the Xorg
15767 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
15769 @item @code{fonts} (default: @code{%default-xorg-fonts})
15770 This is a list of font directories to add to the server's @dfn{font path}.
15772 @item @code{drivers} (default: @code{'()})
15773 This must be either the empty list, in which case Xorg chooses a graphics
15774 driver automatically, or a list of driver names that will be tried in this
15775 order---e.g., @code{("modesetting" "vesa")}.
15777 @item @code{resolutions} (default: @code{'()})
15778 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
15779 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
15782 @cindex keyboard layout, for Xorg
15783 @cindex keymap, for Xorg
15784 @item @code{keyboard-layout} (default: @code{#f})
15785 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
15786 English (``qwerty'') for a 105-key PC keyboard.
15788 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
15789 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
15790 information on how to specify the keyboard layout.
15792 @item @code{extra-config} (default: @code{'()})
15793 This is a list of strings or objects appended to the configuration file. It
15794 is used to pass extra text to be added verbatim to the configuration file.
15796 @item @code{server} (default: @code{xorg-server})
15797 This is the package providing the Xorg server.
15799 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
15800 This is the list of command-line arguments to pass to the X server. The
15801 default is @code{-nolisten tcp}.
15805 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
15806 [@var{login-manager-service-type}]
15807 Tell the log-in manager (of type @var{login-manager-service-type}) to use
15808 @var{config}, an @code{<xorg-configuration>} record.
15810 Since the Xorg configuration is embedded in the log-in manager's
15811 configuration---e.g., @code{gdm-configuration}---this procedure provides a
15812 shorthand to set the Xorg configuration.
15815 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
15816 Return a @code{startx} script in which the modules, fonts, etc. specified
15817 in @var{config}, are available. The result should be used in place of
15820 Usually the X server is started by a login manager.
15824 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
15825 Add @var{package}, a package for a screen locker or screen saver whose
15826 command is @var{program}, to the set of setuid programs and add a PAM entry
15827 for it. For example:
15830 (screen-locker-service xlockmore "xlock")
15833 makes the good ol' XlockMore usable.
15837 @node Printing Services
15838 @subsection Printing Services
15840 @cindex printer support with CUPS
15841 The @code{(gnu services cups)} module provides a Guix service definition
15842 for the CUPS printing service. To add printer support to a Guix
15843 system, add a @code{cups-service} to the operating system definition:
15845 @deffn {Scheme Variable} cups-service-type
15846 The service type for the CUPS print server. Its value should be a valid
15847 CUPS configuration (see below). To use the default settings, simply
15850 (service cups-service-type)
15854 The CUPS configuration controls the basic things about your CUPS
15855 installation: what interfaces it listens on, what to do if a print job
15856 fails, how much logging to do, and so on. To actually add a printer,
15857 you have to visit the @url{http://localhost:631} URL, or use a tool such
15858 as GNOME's printer configuration services. By default, configuring a
15859 CUPS service will generate a self-signed certificate if needed, for
15860 secure connections to the print server.
15862 Suppose you want to enable the Web interface of CUPS and also add
15863 support for Epson printers @i{via} the @code{escpr} package and for HP
15864 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
15865 like this (you need to use the @code{(gnu packages cups)} module):
15868 (service cups-service-type
15869 (cups-configuration
15870 (web-interface? #t)
15872 (list cups-filters escpr hplip-minimal))))
15875 Note: If you wish to use the Qt5 based GUI which comes with the hplip
15876 package then it is suggested that you install the @code{hplip} package,
15877 either in your OS configuration file or as your user.
15879 The available configuration parameters follow. Each parameter
15880 definition is preceded by its type; for example, @samp{string-list foo}
15881 indicates that the @code{foo} parameter should be specified as a list of
15882 strings. There is also a way to specify the configuration as a string,
15883 if you have an old @code{cupsd.conf} file that you want to port over
15884 from some other system; see the end for more details.
15886 @c The following documentation was initially generated by
15887 @c (generate-documentation) in (gnu services cups). Manually maintained
15888 @c documentation is better, so we shouldn't hesitate to edit below as
15889 @c needed. However if the change you want to make to this documentation
15890 @c can be done in an automated way, it's probably easier to change
15891 @c (generate-documentation) than to make it below and have to deal with
15892 @c the churn as CUPS updates.
15895 Available @code{cups-configuration} fields are:
15897 @deftypevr {@code{cups-configuration} parameter} package cups
15901 @deftypevr {@code{cups-configuration} parameter} package-list extensions
15902 Drivers and other extensions to the CUPS package.
15905 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
15906 Configuration of where to write logs, what directories to use for print
15907 spools, and related privileged configuration parameters.
15909 Available @code{files-configuration} fields are:
15911 @deftypevr {@code{files-configuration} parameter} log-location access-log
15912 Defines the access log filename. Specifying a blank filename disables
15913 access log generation. The value @code{stderr} causes log entries to be
15914 sent to the standard error file when the scheduler is running in the
15915 foreground, or to the system log daemon when run in the background. The
15916 value @code{syslog} causes log entries to be sent to the system log
15917 daemon. The server name may be included in filenames using the string
15918 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
15920 Defaults to @samp{"/var/log/cups/access_log"}.
15923 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
15924 Where CUPS should cache data.
15926 Defaults to @samp{"/var/cache/cups"}.
15929 @deftypevr {@code{files-configuration} parameter} string config-file-perm
15930 Specifies the permissions for all configuration files that the scheduler
15933 Note that the permissions for the printers.conf file are currently
15934 masked to only allow access from the scheduler user (typically root).
15935 This is done because printer device URIs sometimes contain sensitive
15936 authentication information that should not be generally known on the
15937 system. There is no way to disable this security feature.
15939 Defaults to @samp{"0640"}.
15942 @deftypevr {@code{files-configuration} parameter} log-location error-log
15943 Defines the error log filename. Specifying a blank filename disables
15944 error log generation. The value @code{stderr} causes log entries to be
15945 sent to the standard error file when the scheduler is running in the
15946 foreground, or to the system log daemon when run in the background. The
15947 value @code{syslog} causes log entries to be sent to the system log
15948 daemon. The server name may be included in filenames using the string
15949 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
15951 Defaults to @samp{"/var/log/cups/error_log"}.
15954 @deftypevr {@code{files-configuration} parameter} string fatal-errors
15955 Specifies which errors are fatal, causing the scheduler to exit. The
15960 No errors are fatal.
15963 All of the errors below are fatal.
15966 Browsing initialization errors are fatal, for example failed connections
15967 to the DNS-SD daemon.
15970 Configuration file syntax errors are fatal.
15973 Listen or Port errors are fatal, except for IPv6 failures on the
15974 loopback or @code{any} addresses.
15977 Log file creation or write errors are fatal.
15980 Bad startup file permissions are fatal, for example shared TLS
15981 certificate and key files with world-read permissions.
15984 Defaults to @samp{"all -browse"}.
15987 @deftypevr {@code{files-configuration} parameter} boolean file-device?
15988 Specifies whether the file pseudo-device can be used for new printer
15989 queues. The URI @uref{file:///dev/null} is always allowed.
15991 Defaults to @samp{#f}.
15994 @deftypevr {@code{files-configuration} parameter} string group
15995 Specifies the group name or ID that will be used when executing external
15998 Defaults to @samp{"lp"}.
16001 @deftypevr {@code{files-configuration} parameter} string log-file-perm
16002 Specifies the permissions for all log files that the scheduler writes.
16004 Defaults to @samp{"0644"}.
16007 @deftypevr {@code{files-configuration} parameter} log-location page-log
16008 Defines the page log filename. Specifying a blank filename disables
16009 page log generation. The value @code{stderr} causes log entries to be
16010 sent to the standard error file when the scheduler is running in the
16011 foreground, or to the system log daemon when run in the background. The
16012 value @code{syslog} causes log entries to be sent to the system log
16013 daemon. The server name may be included in filenames using the string
16014 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
16016 Defaults to @samp{"/var/log/cups/page_log"}.
16019 @deftypevr {@code{files-configuration} parameter} string remote-root
16020 Specifies the username that is associated with unauthenticated accesses
16021 by clients claiming to be the root user. The default is @code{remroot}.
16023 Defaults to @samp{"remroot"}.
16026 @deftypevr {@code{files-configuration} parameter} file-name request-root
16027 Specifies the directory that contains print jobs and other HTTP request
16030 Defaults to @samp{"/var/spool/cups"}.
16033 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
16034 Specifies the level of security sandboxing that is applied to print
16035 filters, backends, and other child processes of the scheduler; either
16036 @code{relaxed} or @code{strict}. This directive is currently only
16037 used/supported on macOS.
16039 Defaults to @samp{strict}.
16042 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
16043 Specifies the location of TLS certificates and private keys. CUPS will
16044 look for public and private keys in this directory: @file{.crt} files
16045 for PEM-encoded certificates and corresponding @file{.key} files for
16046 PEM-encoded private keys.
16048 Defaults to @samp{"/etc/cups/ssl"}.
16051 @deftypevr {@code{files-configuration} parameter} file-name server-root
16052 Specifies the directory containing the server configuration files.
16054 Defaults to @samp{"/etc/cups"}.
16057 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
16058 Specifies whether the scheduler calls fsync(2) after writing
16059 configuration or state files.
16061 Defaults to @samp{#f}.
16064 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
16065 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
16068 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
16069 Specifies the directory where temporary files are stored.
16071 Defaults to @samp{"/var/spool/cups/tmp"}.
16074 @deftypevr {@code{files-configuration} parameter} string user
16075 Specifies the user name or ID that is used when running external
16078 Defaults to @samp{"lp"}.
16081 @deftypevr {@code{files-configuration} parameter} string set-env
16082 Set the specified environment variable to be passed to child processes.
16084 Defaults to @samp{"variable value"}.
16088 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
16089 Specifies the logging level for the AccessLog file. The @code{config}
16090 level logs when printers and classes are added, deleted, or modified and
16091 when configuration files are accessed or updated. The @code{actions}
16092 level logs when print jobs are submitted, held, released, modified, or
16093 canceled, and any of the conditions for @code{config}. The @code{all}
16094 level logs all requests.
16096 Defaults to @samp{actions}.
16099 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
16100 Specifies whether to purge job history data automatically when it is no
16101 longer required for quotas.
16103 Defaults to @samp{#f}.
16106 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
16107 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
16108 For example, @samp{"_cups" "_print"} will tell network clients that both
16109 CUPS sharing and IPP Everywhere are supported.
16111 Defaults to @samp{"_cups"}.
16114 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
16115 Specifies which protocols to use for local printer sharing.
16117 Defaults to @samp{dnssd}.
16120 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
16121 Specifies whether the CUPS web interface is advertised.
16123 Defaults to @samp{#f}.
16126 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
16127 Specifies whether shared printers are advertised.
16129 Defaults to @samp{#f}.
16132 @deftypevr {@code{cups-configuration} parameter} string classification
16133 Specifies the security classification of the server. Any valid banner
16134 name can be used, including @samp{"classified"}, @samp{"confidential"},
16135 @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
16136 banner can be omitted to disable secure printing functions.
16138 Defaults to @samp{""}.
16141 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
16142 Specifies whether users may override the classification (cover page) of
16143 individual print jobs using the @code{job-sheets} option.
16145 Defaults to @samp{#f}.
16148 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
16149 Specifies the default type of authentication to use.
16151 Defaults to @samp{Basic}.
16154 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
16155 Specifies whether encryption will be used for authenticated requests.
16157 Defaults to @samp{Required}.
16160 @deftypevr {@code{cups-configuration} parameter} string default-language
16161 Specifies the default language to use for text and web content.
16163 Defaults to @samp{"en"}.
16166 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
16167 Specifies the default paper size for new print queues. @samp{"Auto"}
16168 uses a locale-specific default, while @samp{"None"} specifies there is
16169 no default paper size. Specific size names are typically
16170 @samp{"Letter"} or @samp{"A4"}.
16172 Defaults to @samp{"Auto"}.
16175 @deftypevr {@code{cups-configuration} parameter} string default-policy
16176 Specifies the default access policy to use.
16178 Defaults to @samp{"default"}.
16181 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
16182 Specifies whether local printers are shared by default.
16184 Defaults to @samp{#t}.
16187 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
16188 Specifies the delay for updating of configuration and state files, in
16189 seconds. A value of 0 causes the update to happen as soon as possible,
16190 typically within a few milliseconds.
16192 Defaults to @samp{30}.
16195 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
16196 Specifies what to do when an error occurs. Possible values are
16197 @code{abort-job}, which will discard the failed print job;
16198 @code{retry-job}, which will retry the job at a later time;
16199 @code{retry-current-job}, which retries the failed job immediately; and
16200 @code{stop-printer}, which stops the printer.
16202 Defaults to @samp{stop-printer}.
16205 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
16206 Specifies the maximum cost of filters that are run concurrently, which
16207 can be used to minimize disk, memory, and CPU resource problems. A
16208 limit of 0 disables filter limiting. An average print to a
16209 non-PostScript printer needs a filter limit of about 200. A PostScript
16210 printer needs about half that (100). Setting the limit below these
16211 thresholds will effectively limit the scheduler to printing a single job
16214 Defaults to @samp{0}.
16217 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
16218 Specifies the scheduling priority of filters that are run to print a
16219 job. The nice value ranges from 0, the highest priority, to 19, the
16222 Defaults to @samp{0}.
16225 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
16226 Specifies whether to do reverse lookups on connecting clients. The
16227 @code{double} setting causes @code{cupsd} to verify that the hostname
16228 resolved from the address matches one of the addresses returned for that
16229 hostname. Double lookups also prevent clients with unregistered
16230 addresses from connecting to your server. Only set this option to
16231 @code{#t} or @code{double} if absolutely required.
16233 Defaults to @samp{#f}.
16236 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
16237 Specifies the number of seconds to wait before killing the filters and
16238 backend associated with a canceled or held job.
16240 Defaults to @samp{30}.
16243 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
16244 Specifies the interval between retries of jobs in seconds. This is
16245 typically used for fax queues but can also be used with normal print
16246 queues whose error policy is @code{retry-job} or
16247 @code{retry-current-job}.
16249 Defaults to @samp{30}.
16252 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
16253 Specifies the number of retries that are done for jobs. This is
16254 typically used for fax queues but can also be used with normal print
16255 queues whose error policy is @code{retry-job} or
16256 @code{retry-current-job}.
16258 Defaults to @samp{5}.
16261 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
16262 Specifies whether to support HTTP keep-alive connections.
16264 Defaults to @samp{#t}.
16267 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
16268 Specifies how long an idle client connection remains open, in seconds.
16270 Defaults to @samp{30}.
16273 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
16274 Specifies the maximum size of print files, IPP requests, and HTML form
16275 data. A limit of 0 disables the limit check.
16277 Defaults to @samp{0}.
16280 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
16281 Listens on the specified interfaces for connections. Valid values are
16282 of the form @var{address}:@var{port}, where @var{address} is either an
16283 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
16284 indicate all addresses. Values can also be file names of local UNIX
16285 domain sockets. The Listen directive is similar to the Port directive
16286 but allows you to restrict access to specific interfaces or networks.
16289 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
16290 Specifies the number of pending connections that will be allowed. This
16291 normally only affects very busy servers that have reached the MaxClients
16292 limit, but can also be triggered by large numbers of simultaneous
16293 connections. When the limit is reached, the operating system will
16294 refuse additional connections until the scheduler can accept the pending
16297 Defaults to @samp{128}.
16300 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
16301 Specifies a set of additional access controls.
16303 Available @code{location-access-controls} fields are:
16305 @deftypevr {@code{location-access-controls} parameter} file-name path
16306 Specifies the URI path to which the access control applies.
16309 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
16310 Access controls for all access to this path, in the same format as the
16311 @code{access-controls} of @code{operation-access-control}.
16313 Defaults to @samp{()}.
16316 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
16317 Access controls for method-specific access to this path.
16319 Defaults to @samp{()}.
16321 Available @code{method-access-controls} fields are:
16323 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
16324 If @code{#t}, apply access controls to all methods except the listed
16325 methods. Otherwise apply to only the listed methods.
16327 Defaults to @samp{#f}.
16330 @deftypevr {@code{method-access-controls} parameter} method-list methods
16331 Methods to which this access control applies.
16333 Defaults to @samp{()}.
16336 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
16337 Access control directives, as a list of strings. Each string should be
16338 one directive, such as @samp{"Order allow,deny"}.
16340 Defaults to @samp{()}.
16345 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
16346 Specifies the number of debugging messages that are retained for logging
16347 if an error occurs in a print job. Debug messages are logged regardless
16348 of the LogLevel setting.
16350 Defaults to @samp{100}.
16353 @deftypevr {@code{cups-configuration} parameter} log-level log-level
16354 Specifies the level of logging for the ErrorLog file. The value
16355 @code{none} stops all logging while @code{debug2} logs everything.
16357 Defaults to @samp{info}.
16360 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
16361 Specifies the format of the date and time in the log files. The value
16362 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
16364 Defaults to @samp{standard}.
16367 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
16368 Specifies the maximum number of simultaneous clients that are allowed by
16371 Defaults to @samp{100}.
16374 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
16375 Specifies the maximum number of simultaneous clients that are allowed
16376 from a single address.
16378 Defaults to @samp{100}.
16381 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
16382 Specifies the maximum number of copies that a user can print of each
16385 Defaults to @samp{9999}.
16388 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
16389 Specifies the maximum time a job may remain in the @code{indefinite}
16390 hold state before it is canceled. A value of 0 disables cancellation of
16393 Defaults to @samp{0}.
16396 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
16397 Specifies the maximum number of simultaneous jobs that are allowed. Set
16398 to 0 to allow an unlimited number of jobs.
16400 Defaults to @samp{500}.
16403 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
16404 Specifies the maximum number of simultaneous jobs that are allowed per
16405 printer. A value of 0 allows up to MaxJobs jobs per printer.
16407 Defaults to @samp{0}.
16410 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
16411 Specifies the maximum number of simultaneous jobs that are allowed per
16412 user. A value of 0 allows up to MaxJobs jobs per user.
16414 Defaults to @samp{0}.
16417 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
16418 Specifies the maximum time a job may take to print before it is
16419 canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
16421 Defaults to @samp{10800}.
16424 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
16425 Specifies the maximum size of the log files before they are rotated, in
16426 bytes. The value 0 disables log rotation.
16428 Defaults to @samp{1048576}.
16431 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
16432 Specifies the maximum amount of time to allow between files in a
16433 multiple file print job, in seconds.
16435 Defaults to @samp{300}.
16438 @deftypevr {@code{cups-configuration} parameter} string page-log-format
16439 Specifies the format of PageLog lines. Sequences beginning with percent
16440 (@samp{%}) characters are replaced with the corresponding information,
16441 while all other characters are copied literally. The following percent
16442 sequences are recognized:
16446 insert a single percent character
16449 insert the value of the specified IPP attribute
16452 insert the number of copies for the current page
16455 insert the current page number
16458 insert the current date and time in common log format
16464 insert the printer name
16467 insert the username
16470 A value of the empty string disables page logging. The string @code{%p
16471 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
16472 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
16475 Defaults to @samp{""}.
16478 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
16479 Passes the specified environment variable(s) to child processes; a list
16482 Defaults to @samp{()}.
16485 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
16486 Specifies named access control policies.
16488 Available @code{policy-configuration} fields are:
16490 @deftypevr {@code{policy-configuration} parameter} string name
16491 Name of the policy.
16494 @deftypevr {@code{policy-configuration} parameter} string job-private-access
16495 Specifies an access list for a job's private values. @code{@@ACL} maps
16496 to the printer's requesting-user-name-allowed or
16497 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
16498 owner. @code{@@SYSTEM} maps to the groups listed for the
16499 @code{system-group} field of the @code{files-config} configuration,
16500 which is reified into the @code{cups-files.conf(5)} file. Other
16501 possible elements of the access list include specific user names, and
16502 @code{@@@var{group}} to indicate members of a specific group. The
16503 access list may also be simply @code{all} or @code{default}.
16505 Defaults to @samp{"@@OWNER @@SYSTEM"}.
16508 @deftypevr {@code{policy-configuration} parameter} string job-private-values
16509 Specifies the list of job values to make private, or @code{all},
16510 @code{default}, or @code{none}.
16512 Defaults to @samp{"job-name job-originating-host-name
16513 job-originating-user-name phone"}.
16516 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
16517 Specifies an access list for a subscription's private values.
16518 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
16519 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
16520 owner. @code{@@SYSTEM} maps to the groups listed for the
16521 @code{system-group} field of the @code{files-config} configuration,
16522 which is reified into the @code{cups-files.conf(5)} file. Other
16523 possible elements of the access list include specific user names, and
16524 @code{@@@var{group}} to indicate members of a specific group. The
16525 access list may also be simply @code{all} or @code{default}.
16527 Defaults to @samp{"@@OWNER @@SYSTEM"}.
16530 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
16531 Specifies the list of job values to make private, or @code{all},
16532 @code{default}, or @code{none}.
16534 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
16535 notify-subscriber-user-name notify-user-data"}.
16538 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
16539 Access control by IPP operation.
16541 Defaults to @samp{()}.
16545 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
16546 Specifies whether job files (documents) are preserved after a job is
16547 printed. If a numeric value is specified, job files are preserved for
16548 the indicated number of seconds after printing. Otherwise a boolean
16549 value applies indefinitely.
16551 Defaults to @samp{86400}.
16554 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
16555 Specifies whether the job history is preserved after a job is printed.
16556 If a numeric value is specified, the job history is preserved for the
16557 indicated number of seconds after printing. If @code{#t}, the job
16558 history is preserved until the MaxJobs limit is reached.
16560 Defaults to @samp{#t}.
16563 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
16564 Specifies the amount of time to wait for job completion before
16565 restarting the scheduler.
16567 Defaults to @samp{30}.
16570 @deftypevr {@code{cups-configuration} parameter} string rip-cache
16571 Specifies the maximum amount of memory to use when converting documents
16572 into bitmaps for a printer.
16574 Defaults to @samp{"128m"}.
16577 @deftypevr {@code{cups-configuration} parameter} string server-admin
16578 Specifies the email address of the server administrator.
16580 Defaults to @samp{"root@@localhost.localdomain"}.
16583 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
16584 The ServerAlias directive is used for HTTP Host header validation when
16585 clients connect to the scheduler from external interfaces. Using the
16586 special name @code{*} can expose your system to known browser-based DNS
16587 rebinding attacks, even when accessing sites through a firewall. If the
16588 auto-discovery of alternate names does not work, we recommend listing
16589 each alternate name with a ServerAlias directive instead of using
16592 Defaults to @samp{*}.
16595 @deftypevr {@code{cups-configuration} parameter} string server-name
16596 Specifies the fully-qualified host name of the server.
16598 Defaults to @samp{"localhost"}.
16601 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
16602 Specifies what information is included in the Server header of HTTP
16603 responses. @code{None} disables the Server header. @code{ProductOnly}
16604 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
16605 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
16606 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
16607 the output of the @code{uname} command. @code{Full} reports @code{CUPS
16608 2.0.0 (@var{uname}) IPP/2.0}.
16610 Defaults to @samp{Minimal}.
16613 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
16614 Listens on the specified interfaces for encrypted connections. Valid
16615 values are of the form @var{address}:@var{port}, where @var{address} is
16616 either an IPv6 address enclosed in brackets, an IPv4 address, or
16617 @code{*} to indicate all addresses.
16619 Defaults to @samp{()}.
16622 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
16623 Sets encryption options. By default, CUPS only supports encryption
16624 using TLS v1.0 or higher using known secure cipher suites. Security is
16625 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
16626 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
16627 suites, which are required for some older clients. The @code{AllowSSL3} option
16628 enables SSL v3.0, which is required for some older clients that do not support
16629 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
16630 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
16631 protocol version to TLS v1.1.
16633 Defaults to @samp{()}.
16636 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
16637 Specifies whether the scheduler requires clients to strictly adhere to
16638 the IPP specifications.
16640 Defaults to @samp{#f}.
16643 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
16644 Specifies the HTTP request timeout, in seconds.
16646 Defaults to @samp{300}.
16650 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
16651 Specifies whether the web interface is enabled.
16653 Defaults to @samp{#f}.
16656 At this point you're probably thinking ``oh dear, Guix manual, I like
16657 you but you can stop already with the configuration options''. Indeed.
16658 However, one more point: it could be that you have an existing
16659 @code{cupsd.conf} that you want to use. In that case, you can pass an
16660 @code{opaque-cups-configuration} as the configuration of a
16661 @code{cups-service-type}.
16663 Available @code{opaque-cups-configuration} fields are:
16665 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
16669 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
16670 The contents of the @code{cupsd.conf}, as a string.
16673 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
16674 The contents of the @code{cups-files.conf} file, as a string.
16677 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
16678 strings of the same name, you could instantiate a CUPS service like
16682 (service cups-service-type
16683 (opaque-cups-configuration
16684 (cupsd.conf cupsd.conf)
16685 (cups-files.conf cups-files.conf)))
16689 @node Desktop Services
16690 @subsection Desktop Services
16692 The @code{(gnu services desktop)} module provides services that are
16693 usually useful in the context of a ``desktop'' setup---that is, on a
16694 machine running a graphical display server, possibly with graphical user
16695 interfaces, etc. It also defines services that provide specific desktop
16696 environments like GNOME, Xfce or MATE.
16698 To simplify things, the module defines a variable containing the set of
16699 services that users typically expect on a machine with a graphical
16700 environment and networking:
16702 @defvr {Scheme Variable} %desktop-services
16703 This is a list of services that builds upon @code{%base-services} and
16704 adds or adjusts services for a typical ``desktop'' setup.
16706 In particular, it adds a graphical login manager (@pxref{X Window,
16707 @code{gdm-service-type}}), screen lockers, a network management tool
16708 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
16709 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
16710 energy and color management services, the @code{elogind} login and seat
16711 manager, the Polkit privilege service, the GeoClue location service, the
16712 AccountsService daemon that allows authorized users change system passwords,
16713 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
16714 name service switch service configured to be able to use @code{nss-mdns}
16715 (@pxref{Name Service Switch, mDNS}).
16718 The @code{%desktop-services} variable can be used as the @code{services}
16719 field of an @code{operating-system} declaration (@pxref{operating-system
16720 Reference, @code{services}}).
16722 Additionally, the @code{gnome-desktop-service-type},
16723 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
16724 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
16725 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
16726 services like the backlight adjustment helpers and the power management
16727 utilities are added to the system, extending @code{polkit} and @code{dbus}
16728 appropriately, allowing GNOME to operate with elevated privileges on a
16729 limited number of special-purpose system interfaces. Additionally,
16730 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
16731 metapackage to the system profile. Likewise, adding the Xfce service
16732 not only adds the @code{xfce} metapackage to the system profile, but it
16733 also gives the Thunar file manager the ability to open a ``root-mode''
16734 file management window, if the user authenticates using the
16735 administrator's password via the standard polkit graphical interface.
16736 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
16737 appropriately, allowing MATE to operate with elevated privileges on a
16738 limited number of special-purpose system interfaces. Additionally,
16739 adding a service of type @code{mate-desktop-service-type} adds the MATE
16740 metapackage to the system profile. ``Adding Enlightenment'' means that
16741 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
16742 are set as setuid, allowing Enlightenment's screen locker and other
16743 functionality to work as expected.
16745 The desktop environments in Guix use the Xorg display server by
16746 default. If you'd like to use the newer display server protocol
16747 called Wayland, you need to use the @code{sddm-service} instead of
16748 GDM as the graphical login manager. You should then
16749 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
16750 also try starting GNOME on Wayland manually from a TTY with the
16751 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
16752 gnome-session``. Currently only GNOME has support for Wayland.
16754 @defvr {Scheme Variable} gnome-desktop-service-type
16755 This is the type of the service that adds the @uref{https://www.gnome.org,
16756 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
16757 object (see below).
16759 This service adds the @code{gnome} package to the system profile, and extends
16760 polkit with the actions from @code{gnome-settings-daemon}.
16763 @deftp {Data Type} gnome-desktop-configuration
16764 Configuration record for the GNOME desktop environment.
16767 @item @code{gnome} (default: @code{gnome})
16768 The GNOME package to use.
16772 @defvr {Scheme Variable} xfce-desktop-service-type
16773 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
16774 desktop environment. Its value is an @code{xfce-desktop-configuration} object
16777 This service adds the @code{xfce} package to the system profile, and
16778 extends polkit with the ability for @code{thunar} to manipulate the file
16779 system as root from within a user session, after the user has authenticated
16780 with the administrator's password.
16783 @deftp {Data Type} xfce-desktop-configuration
16784 Configuration record for the Xfce desktop environment.
16787 @item @code{xfce} (default: @code{xfce})
16788 The Xfce package to use.
16792 @deffn {Scheme Variable} mate-desktop-service-type
16793 This is the type of the service that runs the @uref{https://mate-desktop.org/,
16794 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
16795 object (see below).
16797 This service adds the @code{mate} package to the system
16798 profile, and extends polkit with the actions from
16799 @code{mate-settings-daemon}.
16802 @deftp {Data Type} mate-desktop-configuration
16803 Configuration record for the MATE desktop environment.
16806 @item @code{mate} (default: @code{mate})
16807 The MATE package to use.
16811 @deffn {Scheme Variable} enlightenment-desktop-service-type
16812 Return a service that adds the @code{enlightenment} package to the system
16813 profile, and extends dbus with actions from @code{efl}.
16816 @deftp {Data Type} enlightenment-desktop-service-configuration
16818 @item @code{enlightenment} (default: @code{enlightenment})
16819 The enlightenment package to use.
16823 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
16824 the default @code{%desktop-services} variable doesn't include any of
16825 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
16826 @code{%desktop-services} in the @code{services} field of your
16827 @code{operating-system}:
16830 (use-modules (gnu))
16831 (use-service-modules desktop)
16834 ;; cons* adds items to the list given as its last argument.
16835 (services (cons* (service gnome-desktop-service-type)
16836 (service xfce-desktop-service)
16837 %desktop-services))
16841 These desktop environments will then be available as options in the
16842 graphical login window.
16844 The actual service definitions included in @code{%desktop-services} and
16845 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
16846 are described below.
16848 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
16849 Return a service that runs the ``system bus'', using @var{dbus}, with
16850 support for @var{services}.
16852 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
16853 facility. Its system bus is used to allow system services to communicate
16854 and to be notified of system-wide events.
16856 @var{services} must be a list of packages that provide an
16857 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
16858 and policy files. For example, to allow avahi-daemon to use the system bus,
16859 @var{services} must be equal to @code{(list avahi)}.
16862 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
16863 Return a service that runs the @code{elogind} login and
16864 seat management daemon. @uref{https://github.com/elogind/elogind,
16865 Elogind} exposes a D-Bus interface that can be used to know which users
16866 are logged in, know what kind of sessions they have open, suspend the
16867 system, inhibit system suspend, reboot the system, and other tasks.
16869 Elogind handles most system-level power events for a computer, for
16870 example suspending the system when a lid is closed, or shutting it down
16871 when the power button is pressed.
16873 The @var{config} keyword argument specifies the configuration for
16874 elogind, and should be the result of an @code{(elogind-configuration
16875 (@var{parameter} @var{value})...)} invocation. Available parameters and
16876 their default values are:
16879 @item kill-user-processes?
16881 @item kill-only-users
16883 @item kill-exclude-users
16885 @item inhibit-delay-max-seconds
16887 @item handle-power-key
16889 @item handle-suspend-key
16891 @item handle-hibernate-key
16893 @item handle-lid-switch
16895 @item handle-lid-switch-docked
16897 @item power-key-ignore-inhibited?
16899 @item suspend-key-ignore-inhibited?
16901 @item hibernate-key-ignore-inhibited?
16903 @item lid-switch-ignore-inhibited?
16905 @item holdoff-timeout-seconds
16909 @item idle-action-seconds
16911 @item runtime-directory-size-percent
16913 @item runtime-directory-size
16917 @item suspend-state
16918 @code{("mem" "standby" "freeze")}
16921 @item hibernate-state
16923 @item hibernate-mode
16924 @code{("platform" "shutdown")}
16925 @item hybrid-sleep-state
16927 @item hybrid-sleep-mode
16928 @code{("suspend" "platform" "shutdown")}
16932 @deffn {Scheme Procedure} accountsservice-service @
16933 [#:accountsservice @var{accountsservice}]
16934 Return a service that runs AccountsService, a system service that can
16935 list available accounts, change their passwords, and so on.
16936 AccountsService integrates with PolicyKit to enable unprivileged users
16937 to acquire the capability to modify their system configuration.
16938 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
16939 accountsservice web site} for more information.
16941 The @var{accountsservice} keyword argument is the @code{accountsservice}
16942 package to expose as a service.
16945 @deffn {Scheme Procedure} polkit-service @
16946 [#:polkit @var{polkit}]
16947 Return a service that runs the
16948 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
16949 management service}, which allows system administrators to grant access to
16950 privileged operations in a structured way. By querying the Polkit service, a
16951 privileged system component can know when it should grant additional
16952 capabilities to ordinary users. For example, an ordinary user can be granted
16953 the capability to suspend the system if the user is logged in locally.
16956 @defvr {Scheme Variable} polkit-wheel-service
16957 Service that adds the @code{wheel} group as admins to the Polkit
16958 service. This makes it so that users in the @code{wheel} group are queried
16959 for their own passwords when performing administrative actions instead of
16960 @code{root}'s, similar to the behaviour used by @code{sudo}.
16963 @defvr {Scheme Variable} upower-service-type
16964 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
16965 system-wide monitor for power consumption and battery levels, with the given
16966 configuration settings.
16968 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
16969 notably used by GNOME.
16972 @deftp {Data Type} upower-configuration
16973 Data type representation the configuration for UPower.
16977 @item @code{upower} (default: @var{upower})
16978 Package to use for @code{upower}.
16980 @item @code{watts-up-pro?} (default: @code{#f})
16981 Enable the Watts Up Pro device.
16983 @item @code{poll-batteries?} (default: @code{#t})
16984 Enable polling the kernel for battery level changes.
16986 @item @code{ignore-lid?} (default: @code{#f})
16987 Ignore the lid state, this can be useful if it's incorrect on a device.
16989 @item @code{use-percentage-for-policy?} (default: @code{#f})
16990 Whether battery percentage based policy should be used. The default is to use
16991 the time left, change to @code{#t} to use the percentage.
16993 @item @code{percentage-low} (default: @code{10})
16994 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
16995 at which the battery is considered low.
16997 @item @code{percentage-critical} (default: @code{3})
16998 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
16999 at which the battery is considered critical.
17001 @item @code{percentage-action} (default: @code{2})
17002 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
17003 at which action will be taken.
17005 @item @code{time-low} (default: @code{1200})
17006 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
17007 seconds at which the battery is considered low.
17009 @item @code{time-critical} (default: @code{300})
17010 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
17011 seconds at which the battery is considered critical.
17013 @item @code{time-action} (default: @code{120})
17014 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
17015 seconds at which action will be taken.
17017 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
17018 The action taken when @code{percentage-action} or @code{time-action} is
17019 reached (depending on the configuration of @code{use-percentage-for-policy?}).
17021 Possible values are:
17031 @code{'hybrid-sleep}.
17037 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
17038 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
17039 UDisks}, a @dfn{disk management} daemon that provides user interfaces
17040 with notifications and ways to mount/unmount disks. Programs that talk
17041 to UDisks include the @command{udisksctl} command, part of UDisks, and
17042 GNOME Disks. Note that Udisks relies on the @command{mount} command, so
17043 it will only be able to use the file-system utilities installed in the
17044 system profile. For example if you want to be able to mount NTFS
17045 file-systems in read and write fashion, you'll need to have
17046 @code{ntfs-3g} installed system-wide.
17049 @deffn {Scheme Variable} colord-service-type
17050 This is the type of the service that runs @command{colord}, a system
17051 service with a D-Bus
17052 interface to manage the color profiles of input and output devices such as
17053 screens and scanners. It is notably used by the GNOME Color Manager graphical
17054 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
17055 site} for more information.
17058 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
17059 Return a configuration allowing an application to access GeoClue
17060 location data. @var{name} is the Desktop ID of the application, without
17061 the @code{.desktop} part. If @var{allowed?} is true, the application
17062 will have access to location information by default. The boolean
17063 @var{system?} value indicates whether an application is a system component
17064 or not. Finally @var{users} is a list of UIDs of all users for which
17065 this application is allowed location info access. An empty users list
17066 means that all users are allowed.
17069 @cindex scanner access
17070 @deffn {Scheme Procedure} sane-service-type
17071 This service provides access to scanners @i{via}
17072 @uref{http://www.sane-project.org, SANE} by installing the necessary udev
17076 @defvr {Scheme Variable} %standard-geoclue-applications
17077 The standard list of well-known GeoClue application configurations,
17078 granting authority to the GNOME date-and-time utility to ask for the
17079 current location in order to set the time zone, and allowing the
17080 IceCat and Epiphany web browsers to request location information.
17081 IceCat and Epiphany both query the user before allowing a web page to
17082 know the user's location.
17085 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
17086 [#:whitelist '()] @
17087 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
17088 [#:submit-data? #f]
17089 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
17090 [#:submission-nick "geoclue"] @
17091 [#:applications %standard-geoclue-applications]
17092 Return a service that runs the GeoClue location service. This service
17093 provides a D-Bus interface to allow applications to request access to a
17094 user's physical location, and optionally to add information to online
17095 location databases. See
17096 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
17097 web site} for more information.
17100 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
17101 [@w{#:auto-enable? #f}]
17102 Return a service that runs the @command{bluetoothd} daemon, which
17103 manages all the Bluetooth devices and provides a number of D-Bus
17104 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
17105 powered automatically at boot, which can be useful when using a
17106 bluetooth keyboard or mouse.
17108 Users need to be in the @code{lp} group to access the D-Bus service.
17111 @defvr {Scheme Variable} gnome-keyring-service-type
17112 This is the type of the service that adds the
17113 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
17114 value is a @code{gnome-keyring-configuration} object (see below).
17116 This service adds the @code{gnome-keyring} package to the system profile
17117 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
17118 a user's login keyring when they log in or setting its password with passwd.
17121 @deftp {Data Type} gnome-keyring-configuration
17122 Configuration record for the GNOME Keyring service.
17125 @item @code{keyring} (default: @code{gnome-keyring})
17126 The GNOME keyring package to use.
17128 @item @code{pam-services}
17129 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
17130 services to extend, where @var{service} is the name of an existing
17131 service to extend and @var{kind} is one of @code{login} or
17134 If @code{login} is given, it adds an optional
17135 @code{pam_gnome_keyring.so} to the auth block without arguments and to
17136 the session block with @code{auto_start}. If @code{passwd} is given, it
17137 adds an optional @code{pam_gnome_keyring.so} to the password block
17140 By default, this field contains ``gdm-password'' with the value @code{login}
17141 and ``passwd'' is with the value @code{passwd}.
17146 @node Sound Services
17147 @subsection Sound Services
17149 @cindex sound support
17151 @cindex PulseAudio, sound support
17153 The @code{(gnu services sound)} module provides a service to configure the
17154 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
17155 preferred ALSA output driver.
17157 @deffn {Scheme Variable} alsa-service-type
17158 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
17159 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
17160 configuration file. The value for this type is a @command{alsa-configuration}
17161 record as in this example:
17164 (service alsa-service-type)
17167 See below for details about @code{alsa-configuration}.
17170 @deftp {Data Type} alsa-configuration
17171 Data type representing the configuration for @code{alsa-service}.
17174 @item @code{alsa-plugins} (default: @var{alsa-plugins})
17175 @code{alsa-plugins} package to use.
17177 @item @code{pulseaudio?} (default: @var{#t})
17178 Whether ALSA applications should transparently be made to use the
17179 @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
17181 Using PulseAudio allows you to run several sound-producing applications
17182 at the same time and to individual control them @i{via}
17183 @command{pavucontrol}, among other things.
17185 @item @code{extra-options} (default: @var{""})
17186 String to append to the @file{/etc/asound.conf} file.
17191 Individual users who want to override the system configuration of ALSA can do
17192 it with the @file{~/.asoundrc} file:
17195 # In guix, we have to specify the absolute path for plugins.
17197 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
17200 # Routing ALSA to jack:
17201 # <http://jackaudio.org/faq/routing_alsa.html>.
17205 0 system:playback_1
17206 1 system:playback_2
17223 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
17226 @deffn {Scheme Variable} pulseaudio-service-type
17227 This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
17228 sound server. It exists to allow system overrides of the default settings
17229 via @code{pulseaudio-configuration}, see below.
17232 This service overrides per-user configuration files. If you want
17233 PulseAudio to honor configuraton files in @file{~/.config/pulse} you
17234 have to unset the environment variables @env{PULSE_CONFIG} and
17235 @env{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
17239 This service on its own does not ensure, that the @code{pulseaudio} package
17240 exists on your machine. It merely adds configuration files for it, as
17241 detailed below. In the (admittedly unlikely) case, that you find yourself
17242 without a @code{pulseaudio} package, consider enabling it through the
17243 @code{alsa-service-type} above.
17247 @deftp {Data Type} pulseaudio-configuration
17248 Data type representing the configuration for @code{pulseaudio-service}.
17251 @item @var{client-conf} (default: @code{'()})
17252 List of settings to set in @file{client.conf}.
17253 Accepts a list of strings or a symbol-value pairs. A string will be
17254 inserted as-is with a newline added. A pair will be formatted as
17255 ``key = value'', again with a newline added.
17257 @item @var{daemon-conf} (default: @code{'((flat-volumes . no))})
17258 List of settings to set in @file{daemon.conf}, formatted just like
17261 @item @var{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
17262 Script file to use as as @file{default.pa}.
17264 @item @var{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
17265 Script file to use as as @file{system.pa}.
17269 @deffn {Scheme Variable} ladspa-service-type
17270 This service sets the @var{LADSPA_PATH} variable, so that programs, which
17271 respect it, e.g. PulseAudio, can load LADSPA plugins.
17273 The following example will setup the service to enable modules from the
17274 @code{swh-plugins} package:
17277 (service ladspa-service-type
17278 (ladspa-configuration (plugins (list swh-plugins))))
17281 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
17286 @node Database Services
17287 @subsection Database Services
17291 The @code{(gnu services databases)} module provides the following services.
17293 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
17294 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
17295 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
17296 Return a service that runs @var{postgresql}, the PostgreSQL database
17299 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
17300 creates a database cluster with @var{locale} as the default
17301 locale, stored in @var{data-directory}. It then listens on @var{port}.
17303 If the services fails to start, it may be due to an incompatible
17304 cluster already present in @var{data-directory}. Adjust it (or, if you
17305 don't need the cluster anymore, delete @var{data-directory}), then
17306 restart the service.
17308 Peer authentication is used by default and the @code{postgres} user
17309 account has no shell, which prevents the direct execution of @code{psql}
17310 commands as this user. To use @code{psql}, you can temporarily log in
17311 as @code{postgres} using a shell, create a PostgreSQL superuser with the
17312 same name as one of the system users and then create the associated
17316 sudo -u postgres -s /bin/sh
17317 createuser --interactive
17318 createdb $MY_USER_LOGIN # Replace appropriately.
17321 @cindex postgresql extension-packages
17322 Additional extensions are loaded from packages listed in
17323 @var{extension-packages}. Extensions are available at runtime. For instance,
17324 to create a geographic database using the @code{postgis} extension, a user can
17325 configure the postgresql-service as in this example:
17329 (use-package-modules databases geo)
17333 ;; postgresql is required to run `psql' but postgis is not required for
17334 ;; proper operation.
17335 (packages (cons* postgresql %base-packages))
17338 (postgresql-service #:extension-packages (list postgis))
17342 Then the extension becomes visible and you can initialise an empty geographic
17343 database in this way:
17347 > create database postgistest;
17348 > \connect postgistest;
17349 > create extension postgis;
17350 > create extension postgis_topology;
17353 There is no need to add this field for contrib extensions such as hstore or
17354 dblink as they are already loadable by postgresql. This field is only
17355 required to add extensions provided by other packages.
17358 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
17359 Return a service that runs @command{mysqld}, the MySQL or MariaDB
17362 The optional @var{config} argument specifies the configuration for
17363 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
17366 @deftp {Data Type} mysql-configuration
17367 Data type representing the configuration of @var{mysql-service}.
17370 @item @code{mysql} (default: @var{mariadb})
17371 Package object of the MySQL database server, can be either @var{mariadb}
17374 For MySQL, a temporary root password will be displayed at activation time.
17375 For MariaDB, the root password is empty.
17377 @item @code{port} (default: @code{3306})
17378 TCP port on which the database server listens for incoming connections.
17382 @defvr {Scheme Variable} memcached-service-type
17383 This is the service type for the @uref{https://memcached.org/,
17384 Memcached} service, which provides a distributed in memory cache. The
17385 value for the service type is a @code{memcached-configuration} object.
17389 (service memcached-service-type)
17392 @deftp {Data Type} memcached-configuration
17393 Data type representing the configuration of memcached.
17396 @item @code{memcached} (default: @code{memcached})
17397 The Memcached package to use.
17399 @item @code{interfaces} (default: @code{'("0.0.0.0")})
17400 Network interfaces on which to listen.
17402 @item @code{tcp-port} (default: @code{11211})
17403 Port on which to accept connections on,
17405 @item @code{udp-port} (default: @code{11211})
17406 Port on which to accept UDP connections on, a value of 0 will disable
17407 listening on a UDP socket.
17409 @item @code{additional-options} (default: @code{'()})
17410 Additional command line options to pass to @code{memcached}.
17414 @defvr {Scheme Variable} mongodb-service-type
17415 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
17416 The value for the service type is a @code{mongodb-configuration} object.
17420 (service mongodb-service-type)
17423 @deftp {Data Type} mongodb-configuration
17424 Data type representing the configuration of mongodb.
17427 @item @code{mongodb} (default: @code{mongodb})
17428 The MongoDB package to use.
17430 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
17431 The configuration file for MongoDB.
17433 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
17434 This value is used to create the directory, so that it exists and is
17435 owned by the mongodb user. It should match the data-directory which
17436 MongoDB is configured to use through the configuration file.
17440 @defvr {Scheme Variable} redis-service-type
17441 This is the service type for the @uref{https://redis.io/, Redis}
17442 key/value store, whose value is a @code{redis-configuration} object.
17445 @deftp {Data Type} redis-configuration
17446 Data type representing the configuration of redis.
17449 @item @code{redis} (default: @code{redis})
17450 The Redis package to use.
17452 @item @code{bind} (default: @code{"127.0.0.1"})
17453 Network interface on which to listen.
17455 @item @code{port} (default: @code{6379})
17456 Port on which to accept connections on, a value of 0 will disable
17457 listening on a TCP socket.
17459 @item @code{working-directory} (default: @code{"/var/lib/redis"})
17460 Directory in which to store the database and related files.
17464 @node Mail Services
17465 @subsection Mail Services
17469 The @code{(gnu services mail)} module provides Guix service definitions
17470 for email services: IMAP, POP3, and LMTP servers, as well as mail
17471 transport agents (MTAs). Lots of acronyms! These services are detailed
17472 in the subsections below.
17474 @subsubheading Dovecot Service
17476 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
17477 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
17480 By default, Dovecot does not need much configuration; the default
17481 configuration object created by @code{(dovecot-configuration)} will
17482 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
17483 certificate will be generated for TLS-protected connections, though
17484 Dovecot will also listen on cleartext ports by default. There are a
17485 number of options, though, which mail administrators might need to change,
17486 and as is the case with other services, Guix allows the system
17487 administrator to specify these parameters via a uniform Scheme interface.
17489 For example, to specify that mail is located at @code{maildir~/.mail},
17490 one would instantiate the Dovecot service like this:
17493 (dovecot-service #:config
17494 (dovecot-configuration
17495 (mail-location "maildir:~/.mail")))
17498 The available configuration parameters follow. Each parameter
17499 definition is preceded by its type; for example, @samp{string-list foo}
17500 indicates that the @code{foo} parameter should be specified as a list of
17501 strings. There is also a way to specify the configuration as a string,
17502 if you have an old @code{dovecot.conf} file that you want to port over
17503 from some other system; see the end for more details.
17505 @c The following documentation was initially generated by
17506 @c (generate-documentation) in (gnu services mail). Manually maintained
17507 @c documentation is better, so we shouldn't hesitate to edit below as
17508 @c needed. However if the change you want to make to this documentation
17509 @c can be done in an automated way, it's probably easier to change
17510 @c (generate-documentation) than to make it below and have to deal with
17511 @c the churn as dovecot updates.
17513 Available @code{dovecot-configuration} fields are:
17515 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
17516 The dovecot package.
17519 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
17520 A list of IPs or hosts where to listen for connections. @samp{*}
17521 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
17522 interfaces. If you want to specify non-default ports or anything more
17523 complex, customize the address and port fields of the
17524 @samp{inet-listener} of the specific services you are interested in.
17527 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
17528 List of protocols we want to serve. Available protocols include
17529 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
17531 Available @code{protocol-configuration} fields are:
17533 @deftypevr {@code{protocol-configuration} parameter} string name
17534 The name of the protocol.
17537 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
17538 UNIX socket path to the master authentication server to find users.
17539 This is used by imap (for shared users) and lda.
17540 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
17543 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
17544 Space separated list of plugins to load.
17547 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
17548 Maximum number of IMAP connections allowed for a user from each IP
17549 address. NOTE: The username is compared case-sensitively.
17550 Defaults to @samp{10}.
17555 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
17556 List of services to enable. Available services include @samp{imap},
17557 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
17560 Available @code{service-configuration} fields are:
17562 @deftypevr {@code{service-configuration} parameter} string kind
17563 The service kind. Valid values include @code{director},
17564 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
17565 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
17566 @code{tcpwrap}, @code{quota-warning}, or anything else.
17569 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
17570 Listeners for the service. A listener is either a
17571 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
17572 an @code{inet-listener-configuration}.
17573 Defaults to @samp{()}.
17575 Available @code{unix-listener-configuration} fields are:
17577 @deftypevr {@code{unix-listener-configuration} parameter} string path
17578 Path to the file, relative to @code{base-dir} field. This is also used as
17582 @deftypevr {@code{unix-listener-configuration} parameter} string mode
17583 The access mode for the socket.
17584 Defaults to @samp{"0600"}.
17587 @deftypevr {@code{unix-listener-configuration} parameter} string user
17588 The user to own the socket.
17589 Defaults to @samp{""}.
17592 @deftypevr {@code{unix-listener-configuration} parameter} string group
17593 The group to own the socket.
17594 Defaults to @samp{""}.
17598 Available @code{fifo-listener-configuration} fields are:
17600 @deftypevr {@code{fifo-listener-configuration} parameter} string path
17601 Path to the file, relative to @code{base-dir} field. This is also used as
17605 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
17606 The access mode for the socket.
17607 Defaults to @samp{"0600"}.
17610 @deftypevr {@code{fifo-listener-configuration} parameter} string user
17611 The user to own the socket.
17612 Defaults to @samp{""}.
17615 @deftypevr {@code{fifo-listener-configuration} parameter} string group
17616 The group to own the socket.
17617 Defaults to @samp{""}.
17621 Available @code{inet-listener-configuration} fields are:
17623 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
17624 The protocol to listen for.
17627 @deftypevr {@code{inet-listener-configuration} parameter} string address
17628 The address on which to listen, or empty for all addresses.
17629 Defaults to @samp{""}.
17632 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
17633 The port on which to listen.
17636 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
17637 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
17639 Defaults to @samp{#t}.
17644 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
17645 Maximum number of simultaneous client connections per process. Once
17646 this number of connections is received, the next incoming connection
17647 will prompt Dovecot to spawn another process. If set to 0,
17648 @code{default-client-limit} is used instead.
17650 Defaults to @samp{0}.
17654 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
17655 Number of connections to handle before starting a new process.
17656 Typically the only useful values are 0 (unlimited) or 1. 1 is more
17657 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
17658 Defaults to @samp{1}.
17662 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
17663 Maximum number of processes that can exist for this service. If set to
17664 0, @code{default-process-limit} is used instead.
17666 Defaults to @samp{0}.
17670 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
17671 Number of processes to always keep waiting for more connections.
17672 Defaults to @samp{0}.
17675 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
17676 If you set @samp{service-count 0}, you probably need to grow
17678 Defaults to @samp{256000000}.
17683 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
17684 Dict configuration, as created by the @code{dict-configuration}
17687 Available @code{dict-configuration} fields are:
17689 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
17690 A list of key-value pairs that this dict should hold.
17691 Defaults to @samp{()}.
17696 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
17697 A list of passdb configurations, each one created by the
17698 @code{passdb-configuration} constructor.
17700 Available @code{passdb-configuration} fields are:
17702 @deftypevr {@code{passdb-configuration} parameter} string driver
17703 The driver that the passdb should use. Valid values include
17704 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
17706 Defaults to @samp{"pam"}.
17709 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
17710 Space separated list of arguments to the passdb driver.
17711 Defaults to @samp{""}.
17716 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
17717 List of userdb configurations, each one created by the
17718 @code{userdb-configuration} constructor.
17720 Available @code{userdb-configuration} fields are:
17722 @deftypevr {@code{userdb-configuration} parameter} string driver
17723 The driver that the userdb should use. Valid values include
17724 @samp{passwd} and @samp{static}.
17725 Defaults to @samp{"passwd"}.
17728 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
17729 Space separated list of arguments to the userdb driver.
17730 Defaults to @samp{""}.
17733 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
17734 Override fields from passwd.
17735 Defaults to @samp{()}.
17740 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
17741 Plug-in configuration, created by the @code{plugin-configuration}
17745 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
17746 List of namespaces. Each item in the list is created by the
17747 @code{namespace-configuration} constructor.
17749 Available @code{namespace-configuration} fields are:
17751 @deftypevr {@code{namespace-configuration} parameter} string name
17752 Name for this namespace.
17755 @deftypevr {@code{namespace-configuration} parameter} string type
17756 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
17757 Defaults to @samp{"private"}.
17760 @deftypevr {@code{namespace-configuration} parameter} string separator
17761 Hierarchy separator to use. You should use the same separator for
17762 all namespaces or some clients get confused. @samp{/} is usually a good
17763 one. The default however depends on the underlying mail storage
17765 Defaults to @samp{""}.
17768 @deftypevr {@code{namespace-configuration} parameter} string prefix
17769 Prefix required to access this namespace. This needs to be
17770 different for all namespaces. For example @samp{Public/}.
17771 Defaults to @samp{""}.
17774 @deftypevr {@code{namespace-configuration} parameter} string location
17775 Physical location of the mailbox. This is in the same format as
17776 mail_location, which is also the default for it.
17777 Defaults to @samp{""}.
17780 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
17781 There can be only one INBOX, and this setting defines which
17783 Defaults to @samp{#f}.
17786 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
17787 If namespace is hidden, it's not advertised to clients via NAMESPACE
17788 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
17789 useful when converting from another server with different namespaces
17790 which you want to deprecate but still keep working. For example you can
17791 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
17793 Defaults to @samp{#f}.
17796 @deftypevr {@code{namespace-configuration} parameter} boolean list?
17797 Show the mailboxes under this namespace with the LIST command. This
17798 makes the namespace visible for clients that do not support the NAMESPACE
17799 extension. The special @code{children} value lists child mailboxes, but
17800 hides the namespace prefix.
17801 Defaults to @samp{#t}.
17804 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
17805 Namespace handles its own subscriptions. If set to @code{#f}, the
17806 parent namespace handles them. The empty prefix should always have this
17808 Defaults to @samp{#t}.
17811 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
17812 List of predefined mailboxes in this namespace.
17813 Defaults to @samp{()}.
17815 Available @code{mailbox-configuration} fields are:
17817 @deftypevr {@code{mailbox-configuration} parameter} string name
17818 Name for this mailbox.
17821 @deftypevr {@code{mailbox-configuration} parameter} string auto
17822 @samp{create} will automatically create this mailbox.
17823 @samp{subscribe} will both create and subscribe to the mailbox.
17824 Defaults to @samp{"no"}.
17827 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
17828 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
17829 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
17830 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
17831 Defaults to @samp{()}.
17838 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
17839 Base directory where to store runtime data.
17840 Defaults to @samp{"/var/run/dovecot/"}.
17843 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
17844 Greeting message for clients.
17845 Defaults to @samp{"Dovecot ready."}.
17848 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
17849 List of trusted network ranges. Connections from these IPs are
17850 allowed to override their IP addresses and ports (for logging and for
17851 authentication checks). @samp{disable-plaintext-auth} is also ignored
17852 for these networks. Typically you would specify your IMAP proxy servers
17854 Defaults to @samp{()}.
17857 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
17858 List of login access check sockets (e.g.@: tcpwrap).
17859 Defaults to @samp{()}.
17862 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
17863 Show more verbose process titles (in ps). Currently shows user name
17864 and IP address. Useful for seeing who is actually using the IMAP
17865 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
17867 Defaults to @samp{#f}.
17870 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
17871 Should all processes be killed when Dovecot master process shuts down.
17872 Setting this to @code{#f} means that Dovecot can be upgraded without
17873 forcing existing client connections to close (although that could also
17874 be a problem if the upgrade is e.g.@: due to a security fix).
17875 Defaults to @samp{#t}.
17878 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
17879 If non-zero, run mail commands via this many connections to doveadm
17880 server, instead of running them directly in the same process.
17881 Defaults to @samp{0}.
17884 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
17885 UNIX socket or host:port used for connecting to doveadm server.
17886 Defaults to @samp{"doveadm-server"}.
17889 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
17890 List of environment variables that are preserved on Dovecot startup
17891 and passed down to all of its child processes. You can also give
17892 key=value pairs to always set specific settings.
17895 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
17896 Disable LOGIN command and all other plaintext authentications unless
17897 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
17898 matches the local IP (i.e.@: you're connecting from the same computer),
17899 the connection is considered secure and plaintext authentication is
17900 allowed. See also ssl=required setting.
17901 Defaults to @samp{#t}.
17904 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
17905 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
17906 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
17907 for caching to be used.
17908 Defaults to @samp{0}.
17911 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
17912 Time to live for cached data. After TTL expires the cached record
17913 is no longer used, *except* if the main database lookup returns internal
17914 failure. We also try to handle password changes automatically: If
17915 user's previous authentication was successful, but this one wasn't, the
17916 cache isn't used. For now this works only with plaintext
17918 Defaults to @samp{"1 hour"}.
17921 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
17922 TTL for negative hits (user not found, password mismatch).
17923 0 disables caching them completely.
17924 Defaults to @samp{"1 hour"}.
17927 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
17928 List of realms for SASL authentication mechanisms that need them.
17929 You can leave it empty if you don't want to support multiple realms.
17930 Many clients simply use the first one listed here, so keep the default
17932 Defaults to @samp{()}.
17935 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
17936 Default realm/domain to use if none was specified. This is used for
17937 both SASL realms and appending @@domain to username in plaintext
17939 Defaults to @samp{""}.
17942 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
17943 List of allowed characters in username. If the user-given username
17944 contains a character not listed in here, the login automatically fails.
17945 This is just an extra check to make sure user can't exploit any
17946 potential quote escaping vulnerabilities with SQL/LDAP databases. If
17947 you want to allow all characters, set this value to empty.
17948 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
17951 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
17952 Username character translations before it's looked up from
17953 databases. The value contains series of from -> to characters. For
17954 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
17955 translated to @samp{@@}.
17956 Defaults to @samp{""}.
17959 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
17960 Username formatting before it's looked up from databases. You can
17961 use the standard variables here, e.g.@: %Lu would lowercase the username,
17962 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
17963 change the @samp{@@} into @samp{-AT-}. This translation is done after
17964 @samp{auth-username-translation} changes.
17965 Defaults to @samp{"%Lu"}.
17968 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
17969 If you want to allow master users to log in by specifying the master
17970 username within the normal username string (i.e.@: not using SASL
17971 mechanism's support for it), you can specify the separator character
17972 here. The format is then <username><separator><master username>.
17973 UW-IMAP uses @samp{*} as the separator, so that could be a good
17975 Defaults to @samp{""}.
17978 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
17979 Username to use for users logging in with ANONYMOUS SASL
17981 Defaults to @samp{"anonymous"}.
17984 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
17985 Maximum number of dovecot-auth worker processes. They're used to
17986 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
17987 They're automatically created and destroyed as needed.
17988 Defaults to @samp{30}.
17991 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
17992 Host name to use in GSSAPI principal names. The default is to use
17993 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
17994 allow all keytab entries.
17995 Defaults to @samp{""}.
17998 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
17999 Kerberos keytab to use for the GSSAPI mechanism. Will use the
18000 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
18001 need to change the auth service to run as root to be able to read this
18003 Defaults to @samp{""}.
18006 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
18007 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
18008 and @samp{ntlm-auth} helper.
18009 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
18010 Defaults to @samp{#f}.
18013 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
18014 Path for Samba's @samp{ntlm-auth} helper binary.
18015 Defaults to @samp{"/usr/bin/ntlm_auth"}.
18018 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
18019 Time to delay before replying to failed authentications.
18020 Defaults to @samp{"2 secs"}.
18023 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
18024 Require a valid SSL client certificate or the authentication
18026 Defaults to @samp{#f}.
18029 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
18030 Take the username from client's SSL certificate, using
18031 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
18033 Defaults to @samp{#f}.
18036 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
18037 List of wanted authentication mechanisms. Supported mechanisms are:
18038 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
18039 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
18040 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
18041 @samp{disable-plaintext-auth} setting.
18044 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
18045 List of IPs or hostnames to all director servers, including ourself.
18046 Ports can be specified as ip:port. The default port is the same as what
18047 director service's @samp{inet-listener} is using.
18048 Defaults to @samp{()}.
18051 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
18052 List of IPs or hostnames to all backend mail servers. Ranges are
18053 allowed too, like 10.0.0.10-10.0.0.30.
18054 Defaults to @samp{()}.
18057 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
18058 How long to redirect users to a specific server after it no longer
18059 has any connections.
18060 Defaults to @samp{"15 min"}.
18063 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
18064 How the username is translated before being hashed. Useful values
18065 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
18066 are shared within domain.
18067 Defaults to @samp{"%Lu"}.
18070 @deftypevr {@code{dovecot-configuration} parameter} string log-path
18071 Log file to use for error messages. @samp{syslog} logs to syslog,
18072 @samp{/dev/stderr} logs to stderr.
18073 Defaults to @samp{"syslog"}.
18076 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
18077 Log file to use for informational messages. Defaults to
18079 Defaults to @samp{""}.
18082 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
18083 Log file to use for debug messages. Defaults to
18084 @samp{info-log-path}.
18085 Defaults to @samp{""}.
18088 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
18089 Syslog facility to use if you're logging to syslog. Usually if you
18090 don't want to use @samp{mail}, you'll use local0..local7. Also other
18091 standard facilities are supported.
18092 Defaults to @samp{"mail"}.
18095 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
18096 Log unsuccessful authentication attempts and the reasons why they
18098 Defaults to @samp{#f}.
18101 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
18102 In case of password mismatches, log the attempted password. Valid
18103 values are no, plain and sha1. sha1 can be useful for detecting brute
18104 force password attempts vs. user simply trying the same password over
18105 and over again. You can also truncate the value to n chars by appending
18106 ":n" (e.g.@: sha1:6).
18107 Defaults to @samp{"no"}.
18110 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
18111 Even more verbose logging for debugging purposes. Shows for example
18113 Defaults to @samp{#f}.
18116 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
18117 In case of password mismatches, log the passwords and used scheme so
18118 the problem can be debugged. Enabling this also enables
18120 Defaults to @samp{#f}.
18123 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
18124 Enable mail process debugging. This can help you figure out why
18125 Dovecot isn't finding your mails.
18126 Defaults to @samp{#f}.
18129 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
18130 Show protocol level SSL errors.
18131 Defaults to @samp{#f}.
18134 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
18135 Prefix for each line written to log file. % codes are in
18136 strftime(3) format.
18137 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
18140 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
18141 List of elements we want to log. The elements which have a
18142 non-empty variable value are joined together to form a comma-separated
18146 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
18147 Login log format. %s contains @samp{login-log-format-elements}
18148 string, %$ contains the data we want to log.
18149 Defaults to @samp{"%$: %s"}.
18152 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
18153 Log prefix for mail processes. See doc/wiki/Variables.txt for list
18154 of possible variables you can use.
18155 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
18158 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
18159 Format to use for logging mail deliveries. You can use variables:
18162 Delivery status message (e.g.@: @samp{saved to INBOX})
18174 Defaults to @samp{"msgid=%m: %$"}.
18177 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
18178 Location for users' mailboxes. The default is empty, which means
18179 that Dovecot tries to find the mailboxes automatically. This won't work
18180 if the user doesn't yet have any mail, so you should explicitly tell
18181 Dovecot the full location.
18183 If you're using mbox, giving a path to the INBOX
18184 file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
18185 where the other mailboxes are kept. This is called the @emph{root mail
18186 directory}, and it must be the first path given in the
18187 @samp{mail-location} setting.
18189 There are a few special variables you can use, e.g.:
18195 user part in user@@domain, same as %u if there's no domain
18197 domain part in user@@domain, empty if there's no domain
18202 See doc/wiki/Variables.txt for full list. Some examples:
18204 @item maildir:~/Maildir
18205 @item mbox:~/mail:INBOX=/var/mail/%u
18206 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
18208 Defaults to @samp{""}.
18211 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
18212 System user and group used to access mails. If you use multiple,
18213 userdb can override these by returning uid or gid fields. You can use
18214 either numbers or names. <doc/wiki/UserIds.txt>.
18215 Defaults to @samp{""}.
18218 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
18220 Defaults to @samp{""}.
18223 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
18224 Group to enable temporarily for privileged operations. Currently
18225 this is used only with INBOX when either its initial creation or
18226 dotlocking fails. Typically this is set to @samp{"mail"} to give access to
18228 Defaults to @samp{""}.
18231 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
18232 Grant access to these supplementary groups for mail processes.
18233 Typically these are used to set up access to shared mailboxes. Note
18234 that it may be dangerous to set these if users can create symlinks
18235 (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
18236 could allow a user to delete others' mailboxes, or @code{ln -s
18237 /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
18241 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
18242 Allow full file system access to clients. There's no access checks
18243 other than what the operating system does for the active UID/GID. It
18244 works with both maildir and mboxes, allowing you to prefix mailboxes
18245 names with e.g.@: @file{/path/} or @file{~user/}.
18246 Defaults to @samp{#f}.
18249 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
18250 Don't use @code{mmap()} at all. This is required if you store indexes to
18251 shared file systems (NFS or clustered file system).
18252 Defaults to @samp{#f}.
18255 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
18256 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
18257 supports @samp{O_EXCL} since version 3, so this should be safe to use
18258 nowadays by default.
18259 Defaults to @samp{#t}.
18262 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
18263 When to use fsync() or fdatasync() calls:
18266 Whenever necessary to avoid losing important data
18268 Useful with e.g.@: NFS when @code{write()}s are delayed
18270 Never use it (best performance, but crashes can lose data).
18272 Defaults to @samp{"optimized"}.
18275 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
18276 Mail storage exists in NFS. Set this to yes to make Dovecot flush
18277 NFS caches whenever needed. If you're using only a single mail server
18279 Defaults to @samp{#f}.
18282 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
18283 Mail index files also exist in NFS. Setting this to yes requires
18284 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
18285 Defaults to @samp{#f}.
18288 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
18289 Locking method for index files. Alternatives are fcntl, flock and
18290 dotlock. Dotlocking uses some tricks which may create more disk I/O
18291 than other locking methods. NFS users: flock doesn't work, remember to
18292 change @samp{mmap-disable}.
18293 Defaults to @samp{"fcntl"}.
18296 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
18297 Directory in which LDA/LMTP temporarily stores incoming mails >128
18299 Defaults to @samp{"/tmp"}.
18302 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
18303 Valid UID range for users. This is mostly to make sure that users can't
18304 log in as daemons or other system users. Note that denying root logins is
18305 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
18307 Defaults to @samp{500}.
18310 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
18312 Defaults to @samp{0}.
18315 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
18316 Valid GID range for users. Users having non-valid GID as primary group ID
18317 aren't allowed to log in. If user belongs to supplementary groups with
18318 non-valid GIDs, those groups are not set.
18319 Defaults to @samp{1}.
18322 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
18324 Defaults to @samp{0}.
18327 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
18328 Maximum allowed length for mail keyword name. It's only forced when
18329 trying to create new keywords.
18330 Defaults to @samp{50}.
18333 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
18334 List of directories under which chrooting is allowed for mail
18335 processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
18336 too). This setting doesn't affect @samp{login-chroot}
18337 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
18338 @samp{/./} in home dirs are ignored. WARNING: Never add directories here
18339 which local users can modify, that may lead to root exploit. Usually
18340 this should be done only if you don't allow shell access for users.
18341 <doc/wiki/Chrooting.txt>.
18342 Defaults to @samp{()}.
18345 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
18346 Default chroot directory for mail processes. This can be overridden
18347 for specific users in user database by giving @samp{/./} in user's home
18348 directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
18349 there is no real need to do chrooting, Dovecot doesn't allow users to
18350 access files outside their mail directory anyway. If your home
18351 directories are prefixed with the chroot directory, append @samp{/.} to
18352 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
18353 Defaults to @samp{""}.
18356 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
18357 UNIX socket path to master authentication server to find users.
18358 This is used by imap (for shared users) and lda.
18359 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
18362 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
18363 Directory where to look up mail plugins.
18364 Defaults to @samp{"/usr/lib/dovecot"}.
18367 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
18368 List of plugins to load for all services. Plugins specific to IMAP,
18369 LDA, etc.@: are added to this list in their own .conf files.
18370 Defaults to @samp{()}.
18373 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
18374 The minimum number of mails in a mailbox before updates are done to
18375 cache file. This allows optimizing Dovecot's behavior to do less disk
18376 writes at the cost of more disk reads.
18377 Defaults to @samp{0}.
18380 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
18381 When IDLE command is running, mailbox is checked once in a while to
18382 see if there are any new mails or other changes. This setting defines
18383 the minimum time to wait between those checks. Dovecot can also use
18384 dnotify, inotify and kqueue to find out immediately when changes
18386 Defaults to @samp{"30 secs"}.
18389 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
18390 Save mails with CR+LF instead of plain LF. This makes sending those
18391 mails take less CPU, especially with sendfile() syscall with Linux and
18392 FreeBSD. But it also creates a bit more disk I/O which may just make it
18393 slower. Also note that if other software reads the mboxes/maildirs,
18394 they may handle the extra CRs wrong and cause problems.
18395 Defaults to @samp{#f}.
18398 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
18399 By default LIST command returns all entries in maildir beginning
18400 with a dot. Enabling this option makes Dovecot return only entries
18401 which are directories. This is done by stat()ing each entry, so it
18402 causes more disk I/O.
18403 (For systems setting struct @samp{dirent->d_type} this check is free
18404 and it's done always regardless of this setting).
18405 Defaults to @samp{#f}.
18408 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
18409 When copying a message, do it with hard links whenever possible.
18410 This makes the performance much better, and it's unlikely to have any
18412 Defaults to @samp{#t}.
18415 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
18416 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
18417 directory only when its mtime changes unexpectedly or when we can't find
18418 the mail otherwise.
18419 Defaults to @samp{#f}.
18422 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
18423 Which locking methods to use for locking mbox. There are four
18428 Create <mailbox>.lock file. This is the oldest and most NFS-safe
18429 solution. If you want to use /var/mail/ like directory, the users will
18430 need write access to that directory.
18432 Same as dotlock, but if it fails because of permissions or because there
18433 isn't enough disk space, just skip it.
18435 Use this if possible. Works with NFS too if lockd is used.
18437 May not exist in all systems. Doesn't work with NFS.
18439 May not exist in all systems. Doesn't work with NFS.
18442 You can use multiple locking methods; if you do the order they're declared
18443 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
18444 locking methods as well. Some operating systems don't allow using some of
18445 them simultaneously.
18448 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
18452 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
18453 Maximum time to wait for lock (all of them) before aborting.
18454 Defaults to @samp{"5 mins"}.
18457 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
18458 If dotlock exists but the mailbox isn't modified in any way,
18459 override the lock file after this much time.
18460 Defaults to @samp{"2 mins"}.
18463 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
18464 When mbox changes unexpectedly we have to fully read it to find out
18465 what changed. If the mbox is large this can take a long time. Since
18466 the change is usually just a newly appended mail, it'd be faster to
18467 simply read the new mails. If this setting is enabled, Dovecot does
18468 this but still safely fallbacks to re-reading the whole mbox file
18469 whenever something in mbox isn't how it's expected to be. The only real
18470 downside to this setting is that if some other MUA changes message
18471 flags, Dovecot doesn't notice it immediately. Note that a full sync is
18472 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
18473 Defaults to @samp{#t}.
18476 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
18477 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
18478 EXAMINE, EXPUNGE or CHECK commands. If this is set,
18479 @samp{mbox-dirty-syncs} is ignored.
18480 Defaults to @samp{#f}.
18483 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
18484 Delay writing mbox headers until doing a full write sync (EXPUNGE
18485 and CHECK commands and when closing the mailbox). This is especially
18486 useful for POP3 where clients often delete all mails. The downside is
18487 that our changes aren't immediately visible to other MUAs.
18488 Defaults to @samp{#t}.
18491 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
18492 If mbox size is smaller than this (e.g.@: 100k), don't write index
18493 files. If an index file already exists it's still read, just not
18495 Defaults to @samp{0}.
18498 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
18499 Maximum dbox file size until it's rotated.
18500 Defaults to @samp{10000000}.
18503 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
18504 Maximum dbox file age until it's rotated. Typically in days. Day
18505 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
18507 Defaults to @samp{"1d"}.
18510 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
18511 When creating new mdbox files, immediately preallocate their size to
18512 @samp{mdbox-rotate-size}. This setting currently works only in Linux
18513 with some file systems (ext4, xfs).
18514 Defaults to @samp{#f}.
18517 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
18518 sdbox and mdbox support saving mail attachments to external files,
18519 which also allows single instance storage for them. Other backends
18520 don't support this for now.
18522 WARNING: This feature hasn't been tested much yet. Use at your own risk.
18524 Directory root where to store mail attachments. Disabled, if empty.
18525 Defaults to @samp{""}.
18528 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
18529 Attachments smaller than this aren't saved externally. It's also
18530 possible to write a plugin to disable saving specific attachments
18532 Defaults to @samp{128000}.
18535 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
18536 File system backend to use for saving attachments:
18539 No SiS done by Dovecot (but this might help FS's own deduplication)
18541 SiS with immediate byte-by-byte comparison during saving
18542 @item sis-queue posix
18543 SiS with delayed comparison and deduplication.
18545 Defaults to @samp{"sis posix"}.
18548 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
18549 Hash format to use in attachment filenames. You can add any text and
18550 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
18551 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
18552 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
18553 Defaults to @samp{"%@{sha1@}"}.
18556 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
18558 Defaults to @samp{100}.
18561 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
18563 Defaults to @samp{1000}.
18566 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
18567 Default VSZ (virtual memory size) limit for service processes.
18568 This is mainly intended to catch and kill processes that leak memory
18569 before they eat up everything.
18570 Defaults to @samp{256000000}.
18573 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
18574 Login user is internally used by login processes. This is the most
18575 untrusted user in Dovecot system. It shouldn't have access to anything
18577 Defaults to @samp{"dovenull"}.
18580 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
18581 Internal user is used by unprivileged processes. It should be
18582 separate from login user, so that login processes can't disturb other
18584 Defaults to @samp{"dovecot"}.
18587 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
18588 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
18589 Defaults to @samp{"required"}.
18592 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
18593 PEM encoded X.509 SSL/TLS certificate (public key).
18594 Defaults to @samp{"</etc/dovecot/default.pem"}.
18597 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
18598 PEM encoded SSL/TLS private key. The key is opened before
18599 dropping root privileges, so keep the key file unreadable by anyone but
18601 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
18604 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
18605 If key file is password protected, give the password here.
18606 Alternatively give it when starting dovecot with -p parameter. Since
18607 this file is often world-readable, you may want to place this setting
18608 instead to a different.
18609 Defaults to @samp{""}.
18612 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
18613 PEM encoded trusted certificate authority. Set this only if you
18614 intend to use @samp{ssl-verify-client-cert? #t}. The file should
18615 contain the CA certificate(s) followed by the matching
18616 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
18617 Defaults to @samp{""}.
18620 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
18621 Require that CRL check succeeds for client certificates.
18622 Defaults to @samp{#t}.
18625 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
18626 Request client to send a certificate. If you also want to require
18627 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
18628 Defaults to @samp{#f}.
18631 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
18632 Which field from certificate to use for username. commonName and
18633 x500UniqueIdentifier are the usual choices. You'll also need to set
18634 @samp{auth-ssl-username-from-cert? #t}.
18635 Defaults to @samp{"commonName"}.
18638 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
18639 Minimum SSL protocol version to accept.
18640 Defaults to @samp{"TLSv1"}.
18643 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
18644 SSL ciphers to use.
18645 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
18648 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
18649 SSL crypto device to use, for valid values run "openssl engine".
18650 Defaults to @samp{""}.
18653 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
18654 Address to use when sending rejection mails.
18655 %d expands to recipient domain.
18656 Defaults to @samp{"postmaster@@%d"}.
18659 @deftypevr {@code{dovecot-configuration} parameter} string hostname
18660 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
18661 and in LMTP replies. Default is the system's real hostname@@domain.
18662 Defaults to @samp{""}.
18665 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
18666 If user is over quota, return with temporary failure instead of
18668 Defaults to @samp{#f}.
18671 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
18672 Binary to use for sending mails.
18673 Defaults to @samp{"/usr/sbin/sendmail"}.
18676 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
18677 If non-empty, send mails via this SMTP host[:port] instead of
18679 Defaults to @samp{""}.
18682 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
18683 Subject: header to use for rejection mails. You can use the same
18684 variables as for @samp{rejection-reason} below.
18685 Defaults to @samp{"Rejected: %s"}.
18688 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
18689 Human readable error message for rejection mails. You can use
18702 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
18705 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
18706 Delimiter character between local-part and detail in email
18708 Defaults to @samp{"+"}.
18711 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
18712 Header where the original recipient address (SMTP's RCPT TO:
18713 address) is taken from if not available elsewhere. With dovecot-lda -a
18714 parameter overrides this. A commonly used header for this is
18716 Defaults to @samp{""}.
18719 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
18720 Should saving a mail to a nonexistent mailbox automatically create
18722 Defaults to @samp{#f}.
18725 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
18726 Should automatically created mailboxes be also automatically
18728 Defaults to @samp{#f}.
18731 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
18732 Maximum IMAP command line length. Some clients generate very long
18733 command lines with huge mailboxes, so you may need to raise this if you
18734 get "Too long argument" or "IMAP command line too large" errors
18736 Defaults to @samp{64000}.
18739 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
18740 IMAP logout format string:
18743 total number of bytes read from client
18745 total number of bytes sent to client.
18747 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
18748 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@}"}.
18751 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
18752 Override the IMAP CAPABILITY response. If the value begins with '+',
18753 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
18754 Defaults to @samp{""}.
18757 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
18758 How long to wait between "OK Still here" notifications when client
18760 Defaults to @samp{"2 mins"}.
18763 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
18764 ID field names and values to send to clients. Using * as the value
18765 makes Dovecot use the default value. The following fields have default
18766 values currently: name, version, os, os-version, support-url,
18768 Defaults to @samp{""}.
18771 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
18772 ID fields sent by client to log. * means everything.
18773 Defaults to @samp{""}.
18776 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
18777 Workarounds for various client bugs:
18780 @item delay-newmail
18781 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
18782 CHECK commands. Some clients ignore them otherwise, for example OSX
18783 Mail (<v2.1). Outlook Express breaks more badly though, without this it
18784 may show user "Message no longer in server" errors. Note that OE6
18785 still breaks even with this workaround if synchronization is set to
18788 @item tb-extra-mailbox-sep
18789 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
18790 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
18791 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
18793 @item tb-lsub-flags
18794 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
18795 This makes Thunderbird realize they aren't selectable and show them
18796 greyed out, instead of only later giving "not selectable" popup error.
18798 Defaults to @samp{()}.
18801 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
18802 Host allowed in URLAUTH URLs sent by client. "*" allows all.
18803 Defaults to @samp{""}.
18807 Whew! Lots of configuration options. The nice thing about it though is
18808 that Guix has a complete interface to Dovecot's configuration
18809 language. This allows not only a nice way to declare configurations,
18810 but also offers reflective capabilities as well: users can write code to
18811 inspect and transform configurations from within Scheme.
18813 However, it could be that you just want to get a @code{dovecot.conf} up
18814 and running. In that case, you can pass an
18815 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
18816 @code{dovecot-service}. As its name indicates, an opaque configuration
18817 does not have easy reflective capabilities.
18819 Available @code{opaque-dovecot-configuration} fields are:
18821 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
18822 The dovecot package.
18825 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
18826 The contents of the @code{dovecot.conf}, as a string.
18829 For example, if your @code{dovecot.conf} is just the empty string, you
18830 could instantiate a dovecot service like this:
18833 (dovecot-service #:config
18834 (opaque-dovecot-configuration
18838 @subsubheading OpenSMTPD Service
18840 @deffn {Scheme Variable} opensmtpd-service-type
18841 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
18842 service, whose value should be an @code{opensmtpd-configuration} object
18843 as in this example:
18846 (service opensmtpd-service-type
18847 (opensmtpd-configuration
18848 (config-file (local-file "./my-smtpd.conf"))))
18852 @deftp {Data Type} opensmtpd-configuration
18853 Data type representing the configuration of opensmtpd.
18856 @item @code{package} (default: @var{opensmtpd})
18857 Package object of the OpenSMTPD SMTP server.
18859 @item @code{config-file} (default: @code{%default-opensmtpd-file})
18860 File-like object of the OpenSMTPD configuration file to use. By default
18861 it listens on the loopback network interface, and allows for mail from
18862 users and daemons on the local machine, as well as permitting email to
18863 remote servers. Run @command{man smtpd.conf} for more information.
18868 @subsubheading Exim Service
18870 @cindex mail transfer agent (MTA)
18871 @cindex MTA (mail transfer agent)
18874 @deffn {Scheme Variable} exim-service-type
18875 This is the type of the @uref{https://exim.org, Exim} mail transfer
18876 agent (MTA), whose value should be an @code{exim-configuration} object
18877 as in this example:
18880 (service exim-service-type
18881 (exim-configuration
18882 (config-file (local-file "./my-exim.conf"))))
18886 In order to use an @code{exim-service-type} service you must also have a
18887 @code{mail-aliases-service-type} service present in your
18888 @code{operating-system} (even if it has no aliases).
18890 @deftp {Data Type} exim-configuration
18891 Data type representing the configuration of exim.
18894 @item @code{package} (default: @var{exim})
18895 Package object of the Exim server.
18897 @item @code{config-file} (default: @code{#f})
18898 File-like object of the Exim configuration file to use. If its value is
18899 @code{#f} then use the default configuration file from the package
18900 provided in @code{package}. The resulting configuration file is loaded
18901 after setting the @code{exim_user} and @code{exim_group} configuration
18907 @subsubheading Getmail service
18912 @deffn {Scheme Variable} getmail-service-type
18913 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
18914 mail retriever, whose value should be an @code{getmail-configuration}.
18917 Available @code{getmail-configuration} fields are:
18919 @deftypevr {@code{getmail-configuration} parameter} symbol name
18920 A symbol to identify the getmail service.
18922 Defaults to @samp{"unset"}.
18926 @deftypevr {@code{getmail-configuration} parameter} package package
18927 The getmail package to use.
18931 @deftypevr {@code{getmail-configuration} parameter} string user
18932 The user to run getmail as.
18934 Defaults to @samp{"getmail"}.
18938 @deftypevr {@code{getmail-configuration} parameter} string group
18939 The group to run getmail as.
18941 Defaults to @samp{"getmail"}.
18945 @deftypevr {@code{getmail-configuration} parameter} string directory
18946 The getmail directory to use.
18948 Defaults to @samp{"/var/lib/getmail/default"}.
18952 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
18953 The getmail configuration file to use.
18955 Available @code{getmail-configuration-file} fields are:
18957 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
18958 What mail account to retrieve mail from, and how to access that account.
18960 Available @code{getmail-retriever-configuration} fields are:
18962 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
18963 The type of mail retriever to use. Valid values include @samp{passwd}
18966 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
18970 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
18971 Username to login to the mail server with.
18973 Defaults to @samp{unset}.
18977 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
18978 Username to login to the mail server with.
18980 Defaults to @samp{unset}.
18984 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
18985 Port number to connect to.
18987 Defaults to @samp{#f}.
18991 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
18992 Override fields from passwd.
18994 Defaults to @samp{""}.
18998 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
18999 Override fields from passwd.
19001 Defaults to @samp{()}.
19005 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
19006 PEM-formatted key file to use for the TLS negotiation.
19008 Defaults to @samp{""}.
19012 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
19013 PEM-formatted certificate file to use for the TLS negotiation.
19015 Defaults to @samp{""}.
19019 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
19020 CA certificates to use.
19022 Defaults to @samp{""}.
19026 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
19027 Extra retriever parameters.
19029 Defaults to @samp{()}.
19035 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
19036 What to do with retrieved messages.
19038 Available @code{getmail-destination-configuration} fields are:
19040 @deftypevr {@code{getmail-destination-configuration} parameter} string type
19041 The type of mail destination. Valid values include @samp{Maildir},
19042 @samp{Mboxrd} and @samp{MDA_external}.
19044 Defaults to @samp{unset}.
19048 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
19049 The path option for the mail destination. The behaviour depends on the
19052 Defaults to @samp{""}.
19056 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
19057 Extra destination parameters
19059 Defaults to @samp{()}.
19065 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
19068 Available @code{getmail-options-configuration} fields are:
19070 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
19071 If set to @samp{0}, getmail will only print warnings and errors. A
19072 value of @samp{1} means that messages will be printed about retrieving
19073 and deleting messages. If set to @samp{2}, getmail will print messages
19074 about each of it's actions.
19076 Defaults to @samp{1}.
19080 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
19081 If true, getmail will retrieve all available messages. Otherwise it
19082 will only retrieve messages it hasn't seen previously.
19084 Defaults to @samp{#t}.
19088 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
19089 If set to true, messages will be deleted from the server after
19090 retrieving and successfully delivering them. Otherwise, messages will
19091 be left on the server.
19093 Defaults to @samp{#f}.
19097 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
19098 Getmail will delete messages this number of days after seeing them, if
19099 they have been delivered. This means messages will be left on the
19100 server this number of days after delivering them. A value of @samp{0}
19101 disabled this feature.
19103 Defaults to @samp{0}.
19107 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
19108 Delete messages larger than this of bytes after retrieving them, even if
19109 the delete and delete-after options are disabled. A value of @samp{0}
19110 disables this feature.
19112 Defaults to @samp{0}.
19116 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
19117 Retrieve messages totalling up to this number of bytes before closing
19118 the session with the server. A value of @samp{0} disables this feature.
19120 Defaults to @samp{0}.
19124 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
19125 Don't retrieve messages larger than this number of bytes. A value of
19126 @samp{0} disables this feature.
19128 Defaults to @samp{0}.
19132 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
19133 If true, getmail will add a Delivered-To header to messages.
19135 Defaults to @samp{#t}.
19139 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
19140 If set, getmail adds a Received header to the messages.
19142 Defaults to @samp{#t}.
19146 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
19147 Getmail will record a log of its actions to the named file. A value of
19148 @samp{""} disables this feature.
19150 Defaults to @samp{""}.
19154 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
19155 If true, getmail will record a log of its actions using the system
19158 Defaults to @samp{#f}.
19162 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
19163 If true, getmail will log information about messages not retrieved and
19164 the reason for not retrieving them, as well as starting and ending
19167 Defaults to @samp{#f}.
19171 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
19172 Extra options to include.
19174 Defaults to @samp{()}.
19182 @deftypevr {@code{getmail-configuration} parameter} list idle
19183 A list of mailboxes that getmail should wait on the server for new mail
19184 notifications. This depends on the server supporting the IDLE
19187 Defaults to @samp{()}.
19191 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
19192 Environment variables to set for getmail.
19194 Defaults to @samp{()}.
19198 @subsubheading Mail Aliases Service
19200 @cindex email aliases
19201 @cindex aliases, for email addresses
19203 @deffn {Scheme Variable} mail-aliases-service-type
19204 This is the type of the service which provides @code{/etc/aliases},
19205 specifying how to deliver mail to users on this system.
19208 (service mail-aliases-service-type
19209 '(("postmaster" "bob")
19210 ("bob" "bob@@example.com" "bob@@example2.com")))
19214 The configuration for a @code{mail-aliases-service-type} service is an
19215 association list denoting how to deliver mail that comes to this
19216 system. Each entry is of the form @code{(alias addresses ...)}, with
19217 @code{alias} specifying the local alias and @code{addresses} specifying
19218 where to deliver this user's mail.
19220 The aliases aren't required to exist as users on the local system. In
19221 the above example, there doesn't need to be a @code{postmaster} entry in
19222 the @code{operating-system}'s @code{user-accounts} in order to deliver
19223 the @code{postmaster} mail to @code{bob} (which subsequently would
19224 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
19226 @subsubheading GNU Mailutils IMAP4 Daemon
19227 @cindex GNU Mailutils IMAP4 Daemon
19229 @deffn {Scheme Variable} imap4d-service-type
19230 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
19231 mailutils, GNU Mailutils Manual}), whose value should be an
19232 @code{imap4d-configuration} object as in this example:
19235 (service imap4d-service-type
19236 (imap4d-configuration
19237 (config-file (local-file "imap4d.conf"))))
19241 @deftp {Data Type} imap4d-configuration
19242 Data type representing the configuration of @command{imap4d}.
19245 @item @code{package} (default: @code{mailutils})
19246 The package that provides @command{imap4d}.
19248 @item @code{config-file} (default: @code{%default-imap4d-config-file})
19249 File-like object of the configuration file to use, by default it will listen
19250 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
19251 Mailutils Manual}, for details.
19256 @node Messaging Services
19257 @subsection Messaging Services
19262 The @code{(gnu services messaging)} module provides Guix service
19263 definitions for messaging services: currently only Prosody is supported.
19265 @subsubheading Prosody Service
19267 @deffn {Scheme Variable} prosody-service-type
19268 This is the type for the @uref{https://prosody.im, Prosody XMPP
19269 communication server}. Its value must be a @code{prosody-configuration}
19270 record as in this example:
19273 (service prosody-service-type
19274 (prosody-configuration
19275 (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
19278 (int-component-configuration
19279 (hostname "conference.example.net")
19281 (mod-muc (mod-muc-configuration)))))
19284 (virtualhost-configuration
19285 (domain "example.net"))))))
19288 See below for details about @code{prosody-configuration}.
19292 By default, Prosody does not need much configuration. Only one
19293 @code{virtualhosts} field is needed: it specifies the domain you wish
19296 You can perform various sanity checks on the generated configuration
19297 with the @code{prosodyctl check} command.
19299 Prosodyctl will also help you to import certificates from the
19300 @code{letsencrypt} directory so that the @code{prosody} user can access
19301 them. See @url{https://prosody.im/doc/letsencrypt}.
19304 prosodyctl --root cert import /etc/letsencrypt/live
19307 The available configuration parameters follow. Each parameter
19308 definition is preceded by its type; for example, @samp{string-list foo}
19309 indicates that the @code{foo} parameter should be specified as a list of
19310 strings. Types starting with @code{maybe-} denote parameters that won't
19311 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
19313 There is also a way to specify the configuration as a string, if you
19314 have an old @code{prosody.cfg.lua} file that you want to port over from
19315 some other system; see the end for more details.
19317 The @code{file-object} type designates either a file-like object
19318 (@pxref{G-Expressions, file-like objects}) or a file name.
19320 @c The following documentation was initially generated by
19321 @c (generate-documentation) in (gnu services messaging). Manually maintained
19322 @c documentation is better, so we shouldn't hesitate to edit below as
19323 @c needed. However if the change you want to make to this documentation
19324 @c can be done in an automated way, it's probably easier to change
19325 @c (generate-documentation) than to make it below and have to deal with
19326 @c the churn as Prosody updates.
19328 Available @code{prosody-configuration} fields are:
19330 @deftypevr {@code{prosody-configuration} parameter} package prosody
19331 The Prosody package.
19334 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
19335 Location of the Prosody data storage directory. See
19336 @url{https://prosody.im/doc/configure}.
19337 Defaults to @samp{"/var/lib/prosody"}.
19340 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
19341 Additional plugin directories. They are searched in all the specified
19342 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
19343 Defaults to @samp{()}.
19346 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
19347 Every virtual host and component needs a certificate so that clients and
19348 servers can securely verify its identity. Prosody will automatically load
19349 certificates/keys from the directory specified here.
19350 Defaults to @samp{"/etc/prosody/certs"}.
19353 @deftypevr {@code{prosody-configuration} parameter} string-list admins
19354 This is a list of accounts that are admins for the server. Note that you
19355 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
19356 @url{https://prosody.im/doc/creating_accounts}.
19357 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
19358 Defaults to @samp{()}.
19361 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
19362 Enable use of libevent for better performance under high load. See
19363 @url{https://prosody.im/doc/libevent}.
19364 Defaults to @samp{#f}.
19367 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
19368 This is the list of modules Prosody will load on startup. It looks for
19369 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
19370 Documentation on modules can be found at:
19371 @url{https://prosody.im/doc/modules}.
19372 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
19375 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
19376 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
19377 should you want to disable them then add them to this list.
19378 Defaults to @samp{()}.
19381 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
19382 Path to a text file where the shared groups are defined. If this path is
19383 empty then @samp{mod_groups} does nothing. See
19384 @url{https://prosody.im/doc/modules/mod_groups}.
19385 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
19388 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
19389 Disable account creation by default, for security. See
19390 @url{https://prosody.im/doc/creating_accounts}.
19391 Defaults to @samp{#f}.
19394 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
19395 These are the SSL/TLS-related settings. Most of them are disabled so to
19396 use Prosody's defaults. If you do not completely understand these options, do
19397 not add them to your config, it is easy to lower the security of your server
19398 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
19400 Available @code{ssl-configuration} fields are:
19402 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
19403 This determines what handshake to use.
19406 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
19407 Path to your private key file.
19410 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
19411 Path to your certificate file.
19414 @deftypevr {@code{ssl-configuration} parameter} file-object capath
19415 Path to directory containing root certificates that you wish Prosody to
19416 trust when verifying the certificates of remote servers.
19417 Defaults to @samp{"/etc/ssl/certs"}.
19420 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
19421 Path to a file containing root certificates that you wish Prosody to trust.
19422 Similar to @code{capath} but with all certificates concatenated together.
19425 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
19426 A list of verification options (these mostly map to OpenSSL's
19427 @code{set_verify()} flags).
19430 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
19431 A list of general options relating to SSL/TLS. These map to OpenSSL's
19432 @code{set_options()}. For a full list of options available in LuaSec, see the
19436 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
19437 How long a chain of certificate authorities to check when looking for a
19438 trusted root certificate.
19441 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
19442 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
19443 clients, and in what order.
19446 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
19447 A path to a file containing parameters for Diffie-Hellman key exchange. You
19448 can create such a file with:
19449 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
19452 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
19453 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
19454 @samp{"secp384r1"}.
19457 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
19458 A list of ``extra'' verification options.
19461 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
19462 Password for encrypted private keys.
19467 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
19468 Whether to force all client-to-server connections to be encrypted or not.
19469 See @url{https://prosody.im/doc/modules/mod_tls}.
19470 Defaults to @samp{#f}.
19473 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
19474 Set of mechanisms that will never be offered. See
19475 @url{https://prosody.im/doc/modules/mod_saslauth}.
19476 Defaults to @samp{("DIGEST-MD5")}.
19479 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
19480 Whether to force all server-to-server connections to be encrypted or not.
19481 See @url{https://prosody.im/doc/modules/mod_tls}.
19482 Defaults to @samp{#f}.
19485 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
19486 Whether to require encryption and certificate authentication. This
19487 provides ideal security, but requires servers you communicate with to support
19488 encryption AND present valid, trusted certificates. See
19489 @url{https://prosody.im/doc/s2s#security}.
19490 Defaults to @samp{#f}.
19493 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
19494 Many servers don't support encryption or have invalid or self-signed
19495 certificates. You can list domains here that will not be required to
19496 authenticate using certificates. They will be authenticated using DNS. See
19497 @url{https://prosody.im/doc/s2s#security}.
19498 Defaults to @samp{()}.
19501 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
19502 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
19503 valid certificates for some domains by specifying a list here. See
19504 @url{https://prosody.im/doc/s2s#security}.
19505 Defaults to @samp{()}.
19508 @deftypevr {@code{prosody-configuration} parameter} string authentication
19509 Select the authentication backend to use. The default provider stores
19510 passwords in plaintext and uses Prosody's configured data storage to store the
19511 authentication data. If you do not trust your server please see
19512 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
19513 about using the hashed backend. See also
19514 @url{https://prosody.im/doc/authentication}
19515 Defaults to @samp{"internal_plain"}.
19518 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
19519 Set logging options. Advanced logging configuration is not yet supported
19520 by the Prosody service. See @url{https://prosody.im/doc/logging}.
19521 Defaults to @samp{"*syslog"}.
19524 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
19525 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
19526 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
19529 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
19530 Maximum allowed size of the HTTP body (in bytes).
19533 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
19534 Some modules expose their own URL in various ways. This URL is built
19535 from the protocol, host and port used. If Prosody sits behind a proxy, the
19536 public URL will be @code{http-external-url} instead. See
19537 @url{https://prosody.im/doc/http#external_url}.
19540 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
19541 A host in Prosody is a domain on which user accounts can be created. For
19542 example if you want your users to have addresses like
19543 @samp{"john.smith@@example.com"} then you need to add a host
19544 @samp{"example.com"}. All options in this list will apply only to this host.
19546 Note: the name @emph{virtual} host is used in configuration to avoid confusion with
19547 the actual physical host that Prosody is installed on. A single Prosody
19548 instance can serve many domains, each one defined as a VirtualHost entry in
19549 Prosody's configuration. Conversely a server that hosts a single domain would
19550 have just one VirtualHost entry.
19552 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
19554 Available @code{virtualhost-configuration} fields are:
19556 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:
19557 @deftypevr {@code{virtualhost-configuration} parameter} string domain
19558 Domain you wish Prosody to serve.
19563 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
19564 Components are extra services on a server which are available to clients,
19565 usually on a subdomain of the main server (such as
19566 @samp{"mycomponent.example.com"}). Example components might be chatroom
19567 servers, user directories, or gateways to other protocols.
19569 Internal components are implemented with Prosody-specific plugins. To add an
19570 internal component, you simply fill the hostname field, and the plugin you wish
19571 to use for the component.
19573 See @url{https://prosody.im/doc/components}.
19574 Defaults to @samp{()}.
19576 Available @code{int-component-configuration} fields are:
19578 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:
19579 @deftypevr {@code{int-component-configuration} parameter} string hostname
19580 Hostname of the component.
19583 @deftypevr {@code{int-component-configuration} parameter} string plugin
19584 Plugin you wish to use for the component.
19587 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
19588 Multi-user chat (MUC) is Prosody's module for allowing you to create
19589 hosted chatrooms/conferences for XMPP users.
19591 General information on setting up and using multi-user chatrooms can be found
19592 in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
19593 which you should read if you are new to XMPP chatrooms.
19595 See also @url{https://prosody.im/doc/modules/mod_muc}.
19597 Available @code{mod-muc-configuration} fields are:
19599 @deftypevr {@code{mod-muc-configuration} parameter} string name
19600 The name to return in service discovery responses.
19601 Defaults to @samp{"Prosody Chatrooms"}.
19604 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
19605 If @samp{#t}, this will only allow admins to create new chatrooms.
19606 Otherwise anyone can create a room. The value @samp{"local"} restricts room
19607 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
19608 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
19609 restricts to service administrators only.
19610 Defaults to @samp{#f}.
19613 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
19614 Maximum number of history messages that will be sent to the member that has
19615 just joined the room.
19616 Defaults to @samp{20}.
19623 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
19624 External components use XEP-0114, which most standalone components
19625 support. To add an external component, you simply fill the hostname field. See
19626 @url{https://prosody.im/doc/components}.
19627 Defaults to @samp{()}.
19629 Available @code{ext-component-configuration} fields are:
19631 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:
19632 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
19633 Password which the component will use to log in.
19636 @deftypevr {@code{ext-component-configuration} parameter} string hostname
19637 Hostname of the component.
19642 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
19643 Port(s) Prosody listens on for component connections.
19644 Defaults to @samp{(5347)}.
19647 @deftypevr {@code{prosody-configuration} parameter} string component-interface
19648 Interface Prosody listens on for component connections.
19649 Defaults to @samp{"127.0.0.1"}.
19652 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
19653 Raw content that will be added to the configuration file.
19656 It could be that you just want to get a @code{prosody.cfg.lua}
19657 up and running. In that case, you can pass an
19658 @code{opaque-prosody-configuration} record as the value of
19659 @code{prosody-service-type}. As its name indicates, an opaque configuration
19660 does not have easy reflective capabilities.
19661 Available @code{opaque-prosody-configuration} fields are:
19663 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
19664 The prosody package.
19667 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
19668 The contents of the @code{prosody.cfg.lua} to use.
19671 For example, if your @code{prosody.cfg.lua} is just the empty
19672 string, you could instantiate a prosody service like this:
19675 (service prosody-service-type
19676 (opaque-prosody-configuration
19677 (prosody.cfg.lua "")))
19680 @c end of Prosody auto-generated documentation
19682 @subsubheading BitlBee Service
19684 @cindex IRC (Internet Relay Chat)
19685 @cindex IRC gateway
19686 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
19687 interface to a variety of messaging protocols such as XMPP.
19689 @defvr {Scheme Variable} bitlbee-service-type
19690 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
19691 gateway daemon. Its value is a @code{bitlbee-configuration} (see
19694 To have BitlBee listen on port 6667 on localhost, add this line to your
19698 (service bitlbee-service-type)
19702 @deftp {Data Type} bitlbee-configuration
19703 This is the configuration for BitlBee, with the following fields:
19706 @item @code{interface} (default: @code{"127.0.0.1"})
19707 @itemx @code{port} (default: @code{6667})
19708 Listen on the network interface corresponding to the IP address
19709 specified in @var{interface}, on @var{port}.
19711 When @var{interface} is @code{127.0.0.1}, only local clients can
19712 connect; when it is @code{0.0.0.0}, connections can come from any
19713 networking interface.
19715 @item @code{bitlbee} (default: @code{bitlbee})
19716 The BitlBee package to use.
19718 @item @code{plugins} (default: @code{'()})
19719 List of plugin packages to use---e.g., @code{bitlbee-discord}.
19721 @item @code{extra-settings} (default: @code{""})
19722 Configuration snippet added as-is to the BitlBee configuration file.
19726 @subsubheading Quassel Service
19728 @cindex IRC (Internet Relay Chat)
19729 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
19730 meaning that one or more clients can attach to and detach from the
19733 @defvr {Scheme Variable} quassel-service-type
19734 This is the service type for the @url{https://quassel-irc.org/,Quassel}
19735 IRC backend daemon. Its value is a @code{quassel-configuration}
19739 @deftp {Data Type} quassel-configuration
19740 This is the configuration for Quassel, with the following fields:
19743 @item @code{quassel} (default: @code{quassel})
19744 The Quassel package to use.
19746 @item @code{interface} (default: @code{"::,0.0.0.0"})
19747 @item @code{port} (default: @code{4242})
19748 Listen on the network interface(s) corresponding to the IPv4 or IPv6
19749 interfaces specified in the comma delimited @var{interface}, on
19752 @item @code{loglevel} (default: @code{"Info"})
19753 The level of logging desired. Accepted values are Debug, Info, Warning
19758 @node Telephony Services
19759 @subsection Telephony Services
19761 @cindex Murmur (VoIP server)
19762 @cindex VoIP server
19763 This section describes how to set up and run a Murmur server. Murmur is
19764 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
19767 @deftp {Data Type} murmur-configuration
19768 The service type for the Murmur server. An example configuration can
19772 (service murmur-service-type
19773 (murmur-configuration
19775 "Welcome to this Mumble server running on Guix!")
19776 (cert-required? #t) ;disallow text password logins
19777 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
19778 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
19781 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
19782 password with the command that is printed during the activation phase.
19784 It is recommended to register a normal Mumble user account
19785 and grant it admin or moderator rights.
19786 You can use the @code{mumble} client to
19787 login as new normal user, register yourself, and log out.
19788 For the next step login with the name @code{SuperUser} use
19789 the @code{SuperUser} password that you set previously,
19790 and grant your newly registered mumble user administrator or moderator
19791 rights and create some channels.
19793 Available @code{murmur-configuration} fields are:
19796 @item @code{package} (default: @code{mumble})
19797 Package that contains @code{bin/murmurd}.
19799 @item @code{user} (default: @code{"murmur"})
19800 User who will run the Murmur server.
19802 @item @code{group} (default: @code{"murmur"})
19803 Group of the user who will run the murmur server.
19805 @item @code{port} (default: @code{64738})
19806 Port on which the server will listen.
19808 @item @code{welcome-text} (default: @code{""})
19809 Welcome text sent to clients when they connect.
19811 @item @code{server-password} (default: @code{""})
19812 Password the clients have to enter in order to connect.
19814 @item @code{max-users} (default: @code{100})
19815 Maximum of users that can be connected to the server at once.
19817 @item @code{max-user-bandwidth} (default: @code{#f})
19818 Maximum voice traffic a user can send per second.
19820 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
19821 File name of the sqlite database.
19822 The service's user will become the owner of the directory.
19824 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
19825 File name of the log file.
19826 The service's user will become the owner of the directory.
19828 @item @code{autoban-attempts} (default: @code{10})
19829 Maximum number of logins a user can make in @code{autoban-timeframe}
19830 without getting auto banned for @code{autoban-time}.
19832 @item @code{autoban-timeframe} (default: @code{120})
19833 Timeframe for autoban in seconds.
19835 @item @code{autoban-time} (default: @code{300})
19836 Amount of time in seconds for which a client gets banned
19837 when violating the autoban limits.
19839 @item @code{opus-threshold} (default: @code{100})
19840 Percentage of clients that need to support opus
19841 before switching over to opus audio codec.
19843 @item @code{channel-nesting-limit} (default: @code{10})
19844 How deep channels can be nested at maximum.
19846 @item @code{channelname-regex} (default: @code{#f})
19847 A string in form of a Qt regular expression that channel names must conform to.
19849 @item @code{username-regex} (default: @code{#f})
19850 A string in form of a Qt regular expression that user names must conform to.
19852 @item @code{text-message-length} (default: @code{5000})
19853 Maximum size in bytes that a user can send in one text chat message.
19855 @item @code{image-message-length} (default: @code{(* 128 1024)})
19856 Maximum size in bytes that a user can send in one image message.
19858 @item @code{cert-required?} (default: @code{#f})
19859 If it is set to @code{#t} clients that use weak password authentication
19860 will not be accepted. Users must have completed the certificate wizard to join.
19862 @item @code{remember-channel?} (default: @code{#f})
19863 Should murmur remember the last channel each user was in when they disconnected
19864 and put them into the remembered channel when they rejoin.
19866 @item @code{allow-html?} (default: @code{#f})
19867 Should html be allowed in text messages, user comments, and channel descriptions.
19869 @item @code{allow-ping?} (default: @code{#f})
19870 Setting to true exposes the current user count, the maximum user count, and
19871 the server's maximum bandwidth per client to unauthenticated users. In the
19872 Mumble client, this information is shown in the Connect dialog.
19874 Disabling this setting will prevent public listing of the server.
19876 @item @code{bonjour?} (default: @code{#f})
19877 Should the server advertise itself in the local network through the bonjour protocol.
19879 @item @code{send-version?} (default: @code{#f})
19880 Should the murmur server version be exposed in ping requests.
19882 @item @code{log-days} (default: @code{31})
19883 Murmur also stores logs in the database, which are accessible via RPC.
19884 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
19885 or -1 to disable logging to the database.
19887 @item @code{obfuscate-ips?} (default: @code{#t})
19888 Should logged ips be obfuscated to protect the privacy of users.
19890 @item @code{ssl-cert} (default: @code{#f})
19891 File name of the SSL/TLS certificate used for encrypted connections.
19894 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
19896 @item @code{ssl-key} (default: @code{#f})
19897 Filepath to the ssl private key used for encrypted connections.
19899 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
19902 @item @code{ssl-dh-params} (default: @code{#f})
19903 File name of a PEM-encoded file with Diffie-Hellman parameters
19904 for the SSL/TLS encryption. Alternatively you set it to
19905 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
19906 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
19908 @item @code{ssl-ciphers} (default: @code{#f})
19909 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
19912 This option is specified using
19913 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
19914 OpenSSL cipher list notation}.
19916 It is recommended that you try your cipher string using 'openssl ciphers <string>'
19917 before setting it here, to get a feel for which cipher suites you will get.
19918 After setting this option, it is recommend that you inspect your Murmur log
19919 to ensure that Murmur is using the cipher suites that you expected it to.
19921 Note: Changing this option may impact the backwards compatibility of your
19922 Murmur server, and can remove the ability for older Mumble clients to be able
19925 @item @code{public-registration} (default: @code{#f})
19926 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
19928 You can optionally register your server in the public server list that the
19929 @code{mumble} client shows on startup.
19930 You cannot register your server if you have set a @code{server-password},
19931 or set @code{allow-ping} to @code{#f}.
19933 It might take a few hours until it shows up in the public list.
19935 @item @code{file} (default: @code{#f})
19936 Optional alternative override for this configuration.
19940 @deftp {Data Type} murmur-public-registration-configuration
19941 Configuration for public registration of a murmur service.
19945 This is a display name for your server. Not to be confused with the hostname.
19947 @item @code{password}
19948 A password to identify your registration.
19949 Subsequent updates will need the same password. Don't lose your password.
19952 This should be a @code{http://} or @code{https://} link to your web
19955 @item @code{hostname} (default: @code{#f})
19956 By default your server will be listed by its IP address.
19957 If it is set your server will be linked by this host name instead.
19963 @node Monitoring Services
19964 @subsection Monitoring Services
19966 @subsubheading Tailon Service
19968 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
19969 viewing and searching log files.
19971 The following example will configure the service with default values.
19972 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
19975 (service tailon-service-type)
19978 The following example customises more of the Tailon configuration,
19979 adding @command{sed} to the list of allowed commands.
19982 (service tailon-service-type
19983 (tailon-configuration
19985 (tailon-configuration-file
19986 (allowed-commands '("tail" "grep" "awk" "sed"))))))
19990 @deftp {Data Type} tailon-configuration
19991 Data type representing the configuration of Tailon.
19992 This type has the following parameters:
19995 @item @code{config-file} (default: @code{(tailon-configuration-file)})
19996 The configuration file to use for Tailon. This can be set to a
19997 @dfn{tailon-configuration-file} record value, or any gexp
19998 (@pxref{G-Expressions}).
20000 For example, to instead use a local file, the @code{local-file} function
20004 (service tailon-service-type
20005 (tailon-configuration
20006 (config-file (local-file "./my-tailon.conf"))))
20009 @item @code{package} (default: @code{tailon})
20010 The tailon package to use.
20015 @deftp {Data Type} tailon-configuration-file
20016 Data type representing the configuration options for Tailon.
20017 This type has the following parameters:
20020 @item @code{files} (default: @code{(list "/var/log")})
20021 List of files to display. The list can include strings for a single file
20022 or directory, or a list, where the first item is the name of a
20023 subsection, and the remaining items are the files or directories in that
20026 @item @code{bind} (default: @code{"localhost:8080"})
20027 Address and port to which Tailon should bind on.
20029 @item @code{relative-root} (default: @code{#f})
20030 URL path to use for Tailon, set to @code{#f} to not use a path.
20032 @item @code{allow-transfers?} (default: @code{#t})
20033 Allow downloading the log files in the web interface.
20035 @item @code{follow-names?} (default: @code{#t})
20036 Allow tailing of not-yet existent files.
20038 @item @code{tail-lines} (default: @code{200})
20039 Number of lines to read initially from each file.
20041 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
20042 Commands to allow running. By default, @code{sed} is disabled.
20044 @item @code{debug?} (default: @code{#f})
20045 Set @code{debug?} to @code{#t} to show debug messages.
20047 @item @code{wrap-lines} (default: @code{#t})
20048 Initial line wrapping state in the web interface. Set to @code{#t} to
20049 initially wrap lines (the default), or to @code{#f} to initially not
20052 @item @code{http-auth} (default: @code{#f})
20053 HTTP authentication type to use. Set to @code{#f} to disable
20054 authentication (the default). Supported values are @code{"digest"} or
20057 @item @code{users} (default: @code{#f})
20058 If HTTP authentication is enabled (see @code{http-auth}), access will be
20059 restricted to the credentials provided here. To configure users, use a
20060 list of pairs, where the first element of the pair is the username, and
20061 the 2nd element of the pair is the password.
20064 (tailon-configuration-file
20065 (http-auth "basic")
20066 (users '(("user1" . "password1")
20067 ("user2" . "password2"))))
20074 @subsubheading Darkstat Service
20076 Darkstat is a packet sniffer that captures network traffic, calculates
20077 statistics about usage, and serves reports over HTTP.
20079 @defvar {Scheme Variable} darkstat-service-type
20080 This is the service type for the
20081 @uref{https://unix4lyfe.org/darkstat/, darkstat}
20082 service, its value must be a @code{darkstat-configuration} record as in
20086 (service darkstat-service-type
20087 (darkstat-configuration
20088 (interface "eno1")))
20092 @deftp {Data Type} darkstat-configuration
20093 Data type representing the configuration of @command{darkstat}.
20096 @item @code{package} (default: @code{darkstat})
20097 The darkstat package to use.
20099 @item @code{interface}
20100 Capture traffic on the specified network interface.
20102 @item @code{port} (default: @code{"667"})
20103 Bind the web interface to the specified port.
20105 @item @code{bind-address} (default: @code{"127.0.0.1"})
20106 Bind the web interface to the specified address.
20108 @item @code{base} (default: @code{"/"})
20109 Specify the path of the base URL. This can be useful if
20110 @command{darkstat} is accessed via a reverse proxy.
20115 @subsubheading Prometheus Node Exporter Service
20117 @cindex prometheus-node-exporter
20118 The Prometheus ``node exporter'' makes hardware and operating system statistics
20119 provided by the Linux kernel available for the Prometheus monitoring system.
20120 This service should be deployed on all physical nodes and virtual machines,
20121 where monitoring these statistics is desirable.
20123 @defvar {Scheme variable} prometheus-node-exporter-service-type
20124 This is the service type for the
20125 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
20126 service, its value must be a @code{prometheus-node-exporter-configuration}
20127 record as in this example:
20130 (service prometheus-node-exporter-service-type
20131 (prometheus-node-exporter-configuration
20132 (web-listen-address ":9100")))
20136 @deftp {Data Type} prometheus-node-exporter-configuration
20137 Data type representing the configuration of @command{node_exporter}.
20140 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
20141 The prometheus-node-exporter package to use.
20143 @item @code{web-listen-address} (default: @code{":9100"})
20144 Bind the web interface to the specified address.
20149 @subsubheading Zabbix server
20150 @cindex zabbix zabbix-server
20151 Zabbix provides monitoring metrics, among others network utilization, CPU load
20152 and disk space consumption:
20155 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
20156 @item Auto-discovery of servers and network devices and interfaces.
20157 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
20158 @item Distributed monitoring with centralized web administration.
20159 @item Native high performance agents.
20160 @item SLA, and ITIL KPI metrics on reporting.
20161 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
20162 @item Remote command execution through Zabbix proxies.
20165 @c %start of fragment
20167 Available @code{zabbix-server-configuration} fields are:
20169 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
20170 The zabbix-server package.
20174 @deftypevr {@code{zabbix-server-configuration} parameter} string user
20175 User who will run the Zabbix server.
20177 Defaults to @samp{"zabbix"}.
20181 @deftypevr {@code{zabbix-server-configuration} parameter} group group
20182 Group who will run the Zabbix server.
20184 Defaults to @samp{"zabbix"}.
20188 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
20189 Database host name.
20191 Defaults to @samp{"127.0.0.1"}.
20195 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
20198 Defaults to @samp{"zabbix"}.
20202 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
20205 Defaults to @samp{"zabbix"}.
20209 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
20210 Database password. Please, use @code{include-files} with
20211 @code{DBPassword=SECRET} inside a specified file instead.
20213 Defaults to @samp{""}.
20217 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
20220 Defaults to @samp{5432}.
20224 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
20225 Specifies where log messages are written to:
20229 @code{system} - syslog.
20232 @code{file} - file specified with @code{log-file} parameter.
20235 @code{console} - standard output.
20239 Defaults to @samp{""}.
20243 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
20244 Log file name for @code{log-type} @code{file} parameter.
20246 Defaults to @samp{"/var/log/zabbix/server.log"}.
20250 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
20253 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
20257 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
20258 The location of certificate authority (CA) files for SSL server
20259 certificate verification.
20261 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
20265 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
20266 Location of SSL client certificates.
20268 Defaults to @samp{"/etc/ssl/certs"}.
20272 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
20273 Extra options will be appended to Zabbix server configuration file.
20275 Defaults to @samp{""}.
20279 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
20280 You may include individual files or all files in a directory in the
20281 configuration file.
20283 Defaults to @samp{()}.
20287 @c %end of fragment
20289 @subsubheading Zabbix agent
20290 @cindex zabbix zabbix-agent
20292 Zabbix agent gathers information for Zabbix server.
20294 @c %start of fragment
20296 Available @code{zabbix-agent-configuration} fields are:
20298 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
20299 The zabbix-agent package.
20303 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
20304 User who will run the Zabbix agent.
20306 Defaults to @samp{"zabbix"}.
20310 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
20311 Group who will run the Zabbix agent.
20313 Defaults to @samp{"zabbix"}.
20317 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
20318 Unique, case sensitive hostname which is required for active checks and
20319 must match hostname as configured on the server.
20321 Defaults to @samp{"Zabbix server"}.
20325 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
20326 Specifies where log messages are written to:
20330 @code{system} - syslog.
20333 @code{file} - file specified with @code{log-file} parameter.
20336 @code{console} - standard output.
20340 Defaults to @samp{""}.
20344 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
20345 Log file name for @code{log-type} @code{file} parameter.
20347 Defaults to @samp{"/var/log/zabbix/agent.log"}.
20351 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
20354 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
20358 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
20359 List of IP addresses, optionally in CIDR notation, or hostnames of
20360 Zabbix servers and Zabbix proxies. Incoming connections will be
20361 accepted only from the hosts listed here.
20363 Defaults to @samp{("127.0.0.1")}.
20367 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
20368 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
20369 proxies for active checks. If port is not specified, default port is
20370 used. If this parameter is not specified, active checks are disabled.
20372 Defaults to @samp{("127.0.0.1")}.
20376 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
20377 Extra options will be appended to Zabbix server configuration file.
20379 Defaults to @samp{""}.
20383 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
20384 You may include individual files or all files in a directory in the
20385 configuration file.
20387 Defaults to @samp{()}.
20391 @c %end of fragment
20393 @subsubheading Zabbix front-end
20394 @cindex zabbix zabbix-front-end
20396 This service provides a WEB interface to Zabbix server.
20398 @c %start of fragment
20400 Available @code{zabbix-front-end-configuration} fields are:
20402 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
20403 NGINX configuration.
20407 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
20408 Database host name.
20410 Defaults to @samp{"localhost"}.
20414 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
20417 Defaults to @samp{5432}.
20421 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
20424 Defaults to @samp{"zabbix"}.
20428 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
20431 Defaults to @samp{"zabbix"}.
20435 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
20436 Database password. Please, use @code{db-secret-file} instead.
20438 Defaults to @samp{""}.
20442 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
20443 Secret file which will be appended to @file{zabbix.conf.php} file. This
20444 file contains credentials for use by Zabbix front-end. You are expected
20445 to create it manually.
20447 Defaults to @samp{""}.
20451 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
20452 Zabbix server hostname.
20454 Defaults to @samp{"localhost"}.
20458 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
20459 Zabbix server port.
20461 Defaults to @samp{10051}.
20466 @c %end of fragment
20468 @node Kerberos Services
20469 @subsection Kerberos Services
20472 The @code{(gnu services kerberos)} module provides services relating to
20473 the authentication protocol @dfn{Kerberos}.
20475 @subsubheading Krb5 Service
20477 Programs using a Kerberos client library normally
20478 expect a configuration file in @file{/etc/krb5.conf}.
20479 This service generates such a file from a definition provided in the
20480 operating system declaration.
20481 It does not cause any daemon to be started.
20483 No ``keytab'' files are provided by this service---you must explicitly create them.
20484 This service is known to work with the MIT client library, @code{mit-krb5}.
20485 Other implementations have not been tested.
20487 @defvr {Scheme Variable} krb5-service-type
20488 A service type for Kerberos 5 clients.
20492 Here is an example of its use:
20494 (service krb5-service-type
20495 (krb5-configuration
20496 (default-realm "EXAMPLE.COM")
20497 (allow-weak-crypto? #t)
20500 (name "EXAMPLE.COM")
20501 (admin-server "groucho.example.com")
20502 (kdc "karl.example.com"))
20505 (admin-server "kerb-admin.argrx.edu")
20506 (kdc "keys.argrx.edu"))))))
20510 This example provides a Kerberos@tie{}5 client configuration which:
20512 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
20513 of which have distinct administration servers and key distribution centers;
20514 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
20515 specified by clients;
20516 @item Accepts services which only support encryption types known to be weak.
20519 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
20520 Only the most commonly used ones are described here.
20521 For a full list, and more detailed explanation of each, see the MIT
20522 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
20526 @deftp {Data Type} krb5-realm
20527 @cindex realm, kerberos
20530 This field is a string identifying the name of the realm.
20531 A common convention is to use the fully qualified DNS name of your organization,
20532 converted to upper case.
20534 @item @code{admin-server}
20535 This field is a string identifying the host where the administration server is
20539 This field is a string identifying the key distribution center
20544 @deftp {Data Type} krb5-configuration
20547 @item @code{allow-weak-crypto?} (default: @code{#f})
20548 If this flag is @code{#t} then services which only offer encryption algorithms
20549 known to be weak will be accepted.
20551 @item @code{default-realm} (default: @code{#f})
20552 This field should be a string identifying the default Kerberos
20553 realm for the client.
20554 You should set this field to the name of your Kerberos realm.
20555 If this value is @code{#f}
20556 then a realm must be specified with every Kerberos principal when invoking programs
20557 such as @command{kinit}.
20559 @item @code{realms}
20560 This should be a non-empty list of @code{krb5-realm} objects, which clients may
20562 Normally, one of them will have a @code{name} field matching the @code{default-realm}
20568 @subsubheading PAM krb5 Service
20571 The @code{pam-krb5} service allows for login authentication and password
20572 management via Kerberos.
20573 You will need this service if you want PAM enabled applications to authenticate
20574 users using Kerberos.
20576 @defvr {Scheme Variable} pam-krb5-service-type
20577 A service type for the Kerberos 5 PAM module.
20580 @deftp {Data Type} pam-krb5-configuration
20581 Data type representing the configuration of the Kerberos 5 PAM module.
20582 This type has the following parameters:
20584 @item @code{pam-krb5} (default: @code{pam-krb5})
20585 The pam-krb5 package to use.
20587 @item @code{minimum-uid} (default: @code{1000})
20588 The smallest user ID for which Kerberos authentications should be attempted.
20589 Local accounts with lower values will silently fail to authenticate.
20594 @node LDAP Services
20595 @subsection LDAP Services
20597 @cindex nslcd, LDAP service
20599 The @code{(gnu services authentication)} module provides the
20600 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
20601 server. In addition to configuring the service itself, you may want to add
20602 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
20603 Switch} for detailed information.
20605 Here is a simple operating system declaration with a default configuration of
20606 the @code{nslcd-service-type} and a Name Service Switch configuration that
20607 consults the @code{ldap} name service last:
20610 (use-service-modules authentication)
20611 (use-modules (gnu system nss))
20617 (service nslcd-service-type)
20618 (service dhcp-client-service-type)
20620 (name-service-switch
20621 (let ((services (list (name-service (name "db"))
20622 (name-service (name "files"))
20623 (name-service (name "ldap")))))
20624 (name-service-switch
20625 (inherit %mdns-host-lookup-nss)
20626 (password services)
20629 (netgroup services)
20630 (gshadow services)))))
20633 @c %start of generated documentation for nslcd-configuration
20635 Available @code{nslcd-configuration} fields are:
20637 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
20638 The @code{nss-pam-ldapd} package to use.
20642 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
20643 The number of threads to start that can handle requests and perform LDAP
20644 queries. Each thread opens a separate connection to the LDAP server.
20645 The default is to start 5 threads.
20647 Defaults to @samp{disabled}.
20651 @deftypevr {@code{nslcd-configuration} parameter} string uid
20652 This specifies the user id with which the daemon should be run.
20654 Defaults to @samp{"nslcd"}.
20658 @deftypevr {@code{nslcd-configuration} parameter} string gid
20659 This specifies the group id with which the daemon should be run.
20661 Defaults to @samp{"nslcd"}.
20665 @deftypevr {@code{nslcd-configuration} parameter} log-option log
20666 This option controls the way logging is done via a list containing
20667 SCHEME and LEVEL. The SCHEME argument may either be the symbols
20668 @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
20669 argument is optional and specifies the log level. The log level may be
20670 one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
20671 @samp{notice}, @samp{info} or @samp{debug}. All messages with the
20672 specified log level or higher are logged.
20674 Defaults to @samp{("/var/log/nslcd" info)}.
20678 @deftypevr {@code{nslcd-configuration} parameter} list uri
20679 The list of LDAP server URIs. Normally, only the first server will be
20680 used with the following servers as fall-back.
20682 Defaults to @samp{("ldap://localhost:389/")}.
20686 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
20687 The version of the LDAP protocol to use. The default is to use the
20688 maximum version supported by the LDAP library.
20690 Defaults to @samp{disabled}.
20694 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
20695 Specifies the distinguished name with which to bind to the directory
20696 server for lookups. The default is to bind anonymously.
20698 Defaults to @samp{disabled}.
20702 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
20703 Specifies the credentials with which to bind. This option is only
20704 applicable when used with binddn.
20706 Defaults to @samp{disabled}.
20710 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
20711 Specifies the distinguished name to use when the root user tries to
20712 modify a user's password using the PAM module.
20714 Defaults to @samp{disabled}.
20718 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
20719 Specifies the credentials with which to bind if the root user tries to
20720 change a user's password. This option is only applicable when used with
20723 Defaults to @samp{disabled}.
20727 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
20728 Specifies the SASL mechanism to be used when performing SASL
20731 Defaults to @samp{disabled}.
20735 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
20736 Specifies the SASL realm to be used when performing SASL authentication.
20738 Defaults to @samp{disabled}.
20742 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
20743 Specifies the authentication identity to be used when performing SASL
20746 Defaults to @samp{disabled}.
20750 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
20751 Specifies the authorization identity to be used when performing SASL
20754 Defaults to @samp{disabled}.
20758 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
20759 Determines whether the LDAP server host name should be canonicalised. If
20760 this is enabled the LDAP library will do a reverse host name lookup. By
20761 default, it is left up to the LDAP library whether this check is
20764 Defaults to @samp{disabled}.
20768 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
20769 Set the name for the GSS-API Kerberos credentials cache.
20771 Defaults to @samp{disabled}.
20775 @deftypevr {@code{nslcd-configuration} parameter} string base
20776 The directory search base.
20778 Defaults to @samp{"dc=example,dc=com"}.
20782 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
20783 Specifies the search scope (subtree, onelevel, base or children). The
20784 default scope is subtree; base scope is almost never useful for name
20785 service lookups; children scope is not supported on all servers.
20787 Defaults to @samp{(subtree)}.
20791 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
20792 Specifies the policy for dereferencing aliases. The default policy is
20793 to never dereference aliases.
20795 Defaults to @samp{disabled}.
20799 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
20800 Specifies whether automatic referral chasing should be enabled. The
20801 default behaviour is to chase referrals.
20803 Defaults to @samp{disabled}.
20807 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
20808 This option allows for custom attributes to be looked up instead of the
20809 default RFC 2307 attributes. It is a list of maps, each consisting of
20810 the name of a map, the RFC 2307 attribute to match and the query
20811 expression for the attribute as it is available in the directory.
20813 Defaults to @samp{()}.
20817 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
20818 A list of filters consisting of the name of a map to which the filter
20819 applies and an LDAP search filter expression.
20821 Defaults to @samp{()}.
20825 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
20826 Specifies the time limit in seconds to use when connecting to the
20827 directory server. The default value is 10 seconds.
20829 Defaults to @samp{disabled}.
20833 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
20834 Specifies the time limit (in seconds) to wait for a response from the
20835 LDAP server. A value of zero, which is the default, is to wait
20836 indefinitely for searches to be completed.
20838 Defaults to @samp{disabled}.
20842 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
20843 Specifies the period if inactivity (in seconds) after which the con‐
20844 nection to the LDAP server will be closed. The default is not to time
20847 Defaults to @samp{disabled}.
20851 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
20852 Specifies the number of seconds to sleep when connecting to all LDAP
20853 servers fails. By default one second is waited between the first
20854 failure and the first retry.
20856 Defaults to @samp{disabled}.
20860 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
20861 Specifies the time after which the LDAP server is considered to be
20862 permanently unavailable. Once this time is reached retries will be done
20863 only once per this time period. The default value is 10 seconds.
20865 Defaults to @samp{disabled}.
20869 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
20870 Specifies whether to use SSL/TLS or not (the default is not to). If
20871 'start-tls is specified then StartTLS is used rather than raw LDAP over
20874 Defaults to @samp{disabled}.
20878 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
20879 Specifies what checks to perform on a server-supplied certificate. The
20880 meaning of the values is described in the ldap.conf(5) manual page.
20882 Defaults to @samp{disabled}.
20886 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
20887 Specifies the directory containing X.509 certificates for peer authen‐
20888 tication. This parameter is ignored when using GnuTLS.
20890 Defaults to @samp{disabled}.
20894 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
20895 Specifies the path to the X.509 certificate for peer authentication.
20897 Defaults to @samp{disabled}.
20901 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
20902 Specifies the path to an entropy source. This parameter is ignored when
20905 Defaults to @samp{disabled}.
20909 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
20910 Specifies the ciphers to use for TLS as a string.
20912 Defaults to @samp{disabled}.
20916 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
20917 Specifies the path to the file containing the local certificate for
20918 client TLS authentication.
20920 Defaults to @samp{disabled}.
20924 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
20925 Specifies the path to the file containing the private key for client TLS
20928 Defaults to @samp{disabled}.
20932 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
20933 Set this to a number greater than 0 to request paged results from the
20934 LDAP server in accordance with RFC2696. The default (0) is to not
20935 request paged results.
20937 Defaults to @samp{disabled}.
20941 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
20942 This option prevents group membership lookups through LDAP for the
20943 specified users. Alternatively, the value 'all-local may be used. With
20944 that value nslcd builds a full list of non-LDAP users on startup.
20946 Defaults to @samp{disabled}.
20950 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
20951 This option ensures that LDAP users with a numeric user id lower than
20952 the specified value are ignored.
20954 Defaults to @samp{disabled}.
20958 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
20959 This option specifies an offset that is added to all LDAP numeric user
20960 ids. This can be used to avoid user id collisions with local users.
20962 Defaults to @samp{disabled}.
20966 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
20967 This option specifies an offset that is added to all LDAP numeric group
20968 ids. This can be used to avoid user id collisions with local groups.
20970 Defaults to @samp{disabled}.
20974 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
20975 If this option is set, the member attribute of a group may point to
20976 another group. Members of nested groups are also returned in the higher
20977 level group and parent groups are returned when finding groups for a
20978 specific user. The default is not to perform extra searches for nested
20981 Defaults to @samp{disabled}.
20985 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
20986 If this option is set, the group member list is not retrieved when
20987 looking up groups. Lookups for finding which groups a user belongs to
20988 will remain functional so the user will likely still get the correct
20989 groups assigned on login.
20991 Defaults to @samp{disabled}.
20995 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
20996 If this option is set, functions which cause all user/group entries to
20997 be loaded from the directory will not succeed in doing so. This can
20998 dramatically reduce LDAP server load in situations where there are a
20999 great number of users and/or groups. This option is not recommended for
21000 most configurations.
21002 Defaults to @samp{disabled}.
21006 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
21007 This option can be used to specify how user and group names are verified
21008 within the system. This pattern is used to check all user and group
21009 names that are requested and returned from LDAP.
21011 Defaults to @samp{disabled}.
21015 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
21016 This specifies whether or not to perform searches using case-insensitive
21017 matching. Enabling this could open up the system to authorization
21018 bypass vulnerabilities and introduce nscd cache poisoning
21019 vulnerabilities which allow denial of service.
21021 Defaults to @samp{disabled}.
21025 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
21026 This option specifies whether password policy controls are requested and
21027 handled from the LDAP server when performing user authentication.
21029 Defaults to @samp{disabled}.
21033 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
21034 By default nslcd performs an LDAP search with the user's credentials
21035 after BIND (authentication) to ensure that the BIND operation was
21036 successful. The default search is a simple check to see if the user's
21037 DN exists. A search filter can be specified that will be used instead.
21038 It should return at least one entry.
21040 Defaults to @samp{disabled}.
21044 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
21045 This option allows flexible fine tuning of the authorisation check that
21046 should be performed. The search filter specified is executed and if any
21047 entries match, access is granted, otherwise access is denied.
21049 Defaults to @samp{disabled}.
21053 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
21054 If this option is set password modification using pam_ldap will be
21055 denied and the specified message will be presented to the user instead.
21056 The message can be used to direct the user to an alternative means of
21057 changing their password.
21059 Defaults to @samp{disabled}.
21063 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
21064 List of pam service names for which LDAP authentication should suffice.
21066 Defaults to @samp{()}.
21070 @c %end of generated documentation for nslcd-configuration
21074 @subsection Web Services
21079 The @code{(gnu services web)} module provides the Apache HTTP Server,
21080 the nginx web server, and also a fastcgi wrapper daemon.
21082 @subsubheading Apache HTTP Server
21084 @deffn {Scheme Variable} httpd-service-type
21085 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
21086 (@dfn{httpd}). The value for this service type is a
21087 @code{httpd-configuration} record.
21089 A simple example configuration is given below.
21092 (service httpd-service-type
21093 (httpd-configuration
21096 (server-name "www.example.com")
21097 (document-root "/srv/http/www.example.com")))))
21100 Other services can also extend the @code{httpd-service-type} to add to
21104 (simple-service 'www.example.com-server httpd-service-type
21108 (list (string-join '("ServerName www.example.com"
21109 "DocumentRoot /srv/http/www.example.com")
21114 The details for the @code{httpd-configuration}, @code{httpd-module},
21115 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
21118 @deffn {Data Type} httpd-configuration
21119 This data type represents the configuration for the httpd service.
21122 @item @code{package} (default: @code{httpd})
21123 The httpd package to use.
21125 @item @code{pid-file} (default: @code{"/var/run/httpd"})
21126 The pid file used by the shepherd-service.
21128 @item @code{config} (default: @code{(httpd-config-file)})
21129 The configuration file to use with the httpd service. The default value
21130 is a @code{httpd-config-file} record, but this can also be a different
21131 G-expression that generates a file, for example a @code{plain-file}. A
21132 file outside of the store can also be specified through a string.
21137 @deffn {Data Type} httpd-module
21138 This data type represents a module for the httpd service.
21142 The name of the module.
21145 The file for the module. This can be relative to the httpd package being
21146 used, the absolute location of a file, or a G-expression for a file
21147 within the store, for example @code{(file-append mod-wsgi
21148 "/modules/mod_wsgi.so")}.
21153 @defvr {Scheme Variable} %default-httpd-modules
21154 A default list of @code{httpd-module} objects.
21157 @deffn {Data Type} httpd-config-file
21158 This data type represents a configuration file for the httpd service.
21161 @item @code{modules} (default: @code{%default-httpd-modules})
21162 The modules to load. Additional modules can be added here, or loaded by
21163 additional configuration.
21165 For example, in order to handle requests for PHP files, you can use Apache’s
21166 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
21169 (service httpd-service-type
21170 (httpd-configuration
21175 (name "proxy_module")
21176 (file "modules/mod_proxy.so"))
21178 (name "proxy_fcgi_module")
21179 (file "modules/mod_proxy_fcgi.so"))
21180 %default-httpd-modules))
21181 (extra-config (list "\
21182 <FilesMatch \\.php$>
21183 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
21184 </FilesMatch>"))))))
21185 (service php-fpm-service-type
21186 (php-fpm-configuration
21187 (socket "/var/run/php-fpm.sock")
21188 (socket-group "httpd")))
21191 @item @code{server-root} (default: @code{httpd})
21192 The @code{ServerRoot} in the configuration file, defaults to the httpd
21193 package. Directives including @code{Include} and @code{LoadModule} are
21194 taken as relative to the server root.
21196 @item @code{server-name} (default: @code{#f})
21197 The @code{ServerName} in the configuration file, used to specify the
21198 request scheme, hostname and port that the server uses to identify
21201 This doesn't need to be set in the server config, and can be specified
21202 in virtual hosts. The default is @code{#f} to not specify a
21205 @item @code{document-root} (default: @code{"/srv/http"})
21206 The @code{DocumentRoot} from which files will be served.
21208 @item @code{listen} (default: @code{'("80")})
21209 The list of values for the @code{Listen} directives in the config
21210 file. The value should be a list of strings, when each string can
21211 specify the port number to listen on, and optionally the IP address and
21214 @item @code{pid-file} (default: @code{"/var/run/httpd"})
21215 The @code{PidFile} to use. This should match the @code{pid-file} set in
21216 the @code{httpd-configuration} so that the Shepherd service is
21217 configured correctly.
21219 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
21220 The @code{ErrorLog} to which the server will log errors.
21222 @item @code{user} (default: @code{"httpd"})
21223 The @code{User} which the server will answer requests as.
21225 @item @code{group} (default: @code{"httpd"})
21226 The @code{Group} which the server will answer requests as.
21228 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
21229 A flat list of strings and G-expressions which will be added to the end
21230 of the configuration file.
21232 Any values which the service is extended with will be appended to this
21238 @deffn {Data Type} httpd-virtualhost
21239 This data type represents a virtualhost configuration block for the httpd service.
21241 These should be added to the extra-config for the httpd-service.
21244 (simple-service 'www.example.com-server httpd-service-type
21248 (list (string-join '("ServerName www.example.com"
21249 "DocumentRoot /srv/http/www.example.com")
21254 @item @code{addresses-and-ports}
21255 The addresses and ports for the @code{VirtualHost} directive.
21257 @item @code{contents}
21258 The contents of the @code{VirtualHost} directive, this should be a list
21259 of strings and G-expressions.
21264 @subsubheading NGINX
21266 @deffn {Scheme Variable} nginx-service-type
21267 Service type for the @uref{https://nginx.org/,NGinx} web server. The
21268 value for this service type is a @code{<nginx-configuration>} record.
21270 A simple example configuration is given below.
21273 (service nginx-service-type
21274 (nginx-configuration
21276 (list (nginx-server-configuration
21277 (server-name '("www.example.com"))
21278 (root "/srv/http/www.example.com"))))))
21281 In addition to adding server blocks to the service configuration
21282 directly, this service can be extended by other services to add server
21283 blocks, as in this example:
21286 (simple-service 'my-extra-server nginx-service-type
21287 (list (nginx-server-configuration
21288 (root "/srv/http/extra-website")
21289 (try-files (list "$uri" "$uri/index.html")))))
21293 At startup, @command{nginx} has not yet read its configuration file, so
21294 it uses a default file to log error messages. If it fails to load its
21295 configuration file, that is where error messages are logged. After the
21296 configuration file is loaded, the default error log file changes as per
21297 configuration. In our case, startup error messages can be found in
21298 @file{/var/run/nginx/logs/error.log}, and after configuration in
21299 @file{/var/log/nginx/error.log}. The second location can be changed
21300 with the @var{log-directory} configuration option.
21302 @deffn {Data Type} nginx-configuration
21303 This data type represents the configuration for NGinx. Some
21304 configuration can be done through this and the other provided record
21305 types, or alternatively, a config file can be provided.
21308 @item @code{nginx} (default: @code{nginx})
21309 The nginx package to use.
21311 @item @code{log-directory} (default: @code{"/var/log/nginx"})
21312 The directory to which NGinx will write log files.
21314 @item @code{run-directory} (default: @code{"/var/run/nginx"})
21315 The directory in which NGinx will create a pid file, and write temporary
21318 @item @code{server-blocks} (default: @code{'()})
21319 A list of @dfn{server blocks} to create in the generated configuration
21320 file, the elements should be of type
21321 @code{<nginx-server-configuration>}.
21323 The following example would setup NGinx to serve @code{www.example.com}
21324 from the @code{/srv/http/www.example.com} directory, without using
21327 (service nginx-service-type
21328 (nginx-configuration
21330 (list (nginx-server-configuration
21331 (server-name '("www.example.com"))
21332 (root "/srv/http/www.example.com"))))))
21335 @item @code{upstream-blocks} (default: @code{'()})
21336 A list of @dfn{upstream blocks} to create in the generated configuration
21337 file, the elements should be of type
21338 @code{<nginx-upstream-configuration>}.
21340 Configuring upstreams through the @code{upstream-blocks} can be useful
21341 when combined with @code{locations} in the
21342 @code{<nginx-server-configuration>} records. The following example
21343 creates a server configuration with one location configuration, that
21344 will proxy requests to a upstream configuration, which will handle
21345 requests with two servers.
21350 (nginx-configuration
21352 (list (nginx-server-configuration
21353 (server-name '("www.example.com"))
21354 (root "/srv/http/www.example.com")
21357 (nginx-location-configuration
21359 (body '("proxy_pass http://server-proxy;"))))))))
21361 (list (nginx-upstream-configuration
21362 (name "server-proxy")
21363 (servers (list "server1.example.com"
21364 "server2.example.com")))))))
21367 @item @code{file} (default: @code{#f})
21368 If a configuration @var{file} is provided, this will be used, rather than
21369 generating a configuration file from the provided @code{log-directory},
21370 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
21371 proper operation, these arguments should match what is in @var{file} to ensure
21372 that the directories are created when the service is activated.
21374 This can be useful if you have an existing configuration file, or it's
21375 not possible to do what is required through the other parts of the
21376 nginx-configuration record.
21378 @item @code{server-names-hash-bucket-size} (default: @code{#f})
21379 Bucket size for the server names hash tables, defaults to @code{#f} to
21380 use the size of the processors cache line.
21382 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
21383 Maximum bucket size for the server names hash tables.
21385 @item @code{modules} (default: @code{'()})
21386 List of nginx dynamic modules to load. This should be a list of file
21387 names of loadable modules, as in this example:
21392 (file-append nginx-accept-language-module "\
21393 /etc/nginx/modules/ngx_http_accept_language_module.so")))
21396 @item @code{global-directives} (default: @code{'((events . ()))})
21397 Association list of global directives for the top level of the nginx
21398 configuration. Values may themselves be association lists.
21402 `((worker_processes . 16)
21404 (events . ((worker_connections . 1024)))))
21407 @item @code{extra-content} (default: @code{""})
21408 Extra content for the @code{http} block. Should be string or a string
21409 valued G-expression.
21414 @deftp {Data Type} nginx-server-configuration
21415 Data type representing the configuration of an nginx server block.
21416 This type has the following parameters:
21419 @item @code{listen} (default: @code{'("80" "443 ssl")})
21420 Each @code{listen} directive sets the address and port for IP, or the
21421 path for a UNIX-domain socket on which the server will accept requests.
21422 Both address and port, or only address or only port can be specified.
21423 An address may also be a hostname, for example:
21426 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
21429 @item @code{server-name} (default: @code{(list 'default)})
21430 A list of server names this server represents. @code{'default} represents the
21431 default server for connections matching no other server.
21433 @item @code{root} (default: @code{"/srv/http"})
21434 Root of the website nginx will serve.
21436 @item @code{locations} (default: @code{'()})
21437 A list of @dfn{nginx-location-configuration} or
21438 @dfn{nginx-named-location-configuration} records to use within this
21441 @item @code{index} (default: @code{(list "index.html")})
21442 Index files to look for when clients ask for a directory. If it cannot be found,
21443 Nginx will send the list of files in the directory.
21445 @item @code{try-files} (default: @code{'()})
21446 A list of files whose existence is checked in the specified order.
21447 @code{nginx} will use the first file it finds to process the request.
21449 @item @code{ssl-certificate} (default: @code{#f})
21450 Where to find the certificate for secure connections. Set it to @code{#f} if
21451 you don't have a certificate or you don't want to use HTTPS.
21453 @item @code{ssl-certificate-key} (default: @code{#f})
21454 Where to find the private key for secure connections. Set it to @code{#f} if
21455 you don't have a key or you don't want to use HTTPS.
21457 @item @code{server-tokens?} (default: @code{#f})
21458 Whether the server should add its configuration to response.
21460 @item @code{raw-content} (default: @code{'()})
21461 A list of raw lines added to the server block.
21466 @deftp {Data Type} nginx-upstream-configuration
21467 Data type representing the configuration of an nginx @code{upstream}
21468 block. This type has the following parameters:
21472 Name for this group of servers.
21474 @item @code{servers}
21475 Specify the addresses of the servers in the group. The address can be
21476 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
21477 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
21478 prefix @samp{unix:}. For addresses using an IP address or domain name,
21479 the default port is 80, and a different port can be specified
21485 @deftp {Data Type} nginx-location-configuration
21486 Data type representing the configuration of an nginx @code{location}
21487 block. This type has the following parameters:
21491 URI which this location block matches.
21493 @anchor{nginx-location-configuration body}
21495 Body of the location block, specified as a list of strings. This can contain
21497 configuration directives. For example, to pass requests to a upstream
21498 server group defined using an @code{nginx-upstream-configuration} block,
21499 the following directive would be specified in the body @samp{(list "proxy_pass
21500 http://upstream-name;")}.
21505 @deftp {Data Type} nginx-named-location-configuration
21506 Data type representing the configuration of an nginx named location
21507 block. Named location blocks are used for request redirection, and not
21508 used for regular request processing. This type has the following
21513 Name to identify this location block.
21516 @xref{nginx-location-configuration body}, as the body for named location
21517 blocks can be used in a similar way to the
21518 @code{nginx-location-configuration body}. One restriction is that the
21519 body of a named location block cannot contain location blocks.
21524 @subsubheading Varnish Cache
21526 Varnish is a fast cache server that sits in between web applications
21527 and end users. It proxies requests from clients and caches the
21528 accessed URLs such that multiple requests for the same resource only
21529 creates one request to the back-end.
21531 @defvr {Scheme Variable} varnish-service-type
21532 Service type for the Varnish daemon.
21535 @deftp {Data Type} varnish-configuration
21536 Data type representing the @code{varnish} service configuration.
21537 This type has the following parameters:
21540 @item @code{package} (default: @code{varnish})
21541 The Varnish package to use.
21543 @item @code{name} (default: @code{"default"})
21544 A name for this Varnish instance. Varnish will create a directory in
21545 @file{/var/varnish/} with this name and keep temporary files there. If
21546 the name starts with a forward slash, it is interpreted as an absolute
21549 Pass the @code{-n} argument to other Varnish programs to connect to the
21550 named instance, e.g.@: @command{varnishncsa -n default}.
21552 @item @code{backend} (default: @code{"localhost:8080"})
21553 The backend to use. This option has no effect if @code{vcl} is set.
21555 @item @code{vcl} (default: #f)
21556 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
21557 is @code{#f}, Varnish will proxy @code{backend} using the default
21558 configuration. Otherwise this must be a file-like object with valid
21561 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
21562 For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
21563 can do something along these lines:
21566 (define %gnu-mirror
21567 (plain-file "gnu.vcl"
21569 backend gnu @{ .host = \"www.gnu.org\"; @}"))
21573 (services (cons (service varnish-service-type
21574 (varnish-configuration
21576 (vcl %gnu-mirror)))
21580 The configuration of an already running Varnish instance can be inspected
21581 and changed using the @command{varnishadm} program.
21583 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
21584 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
21585 comprehensive documentation on Varnish and its configuration language.
21587 @item @code{listen} (default: @code{'("localhost:80")})
21588 List of addresses Varnish will listen on.
21590 @item @code{storage} (default: @code{'("malloc,128m")})
21591 List of storage backends that will be available in VCL.
21593 @item @code{parameters} (default: @code{'()})
21594 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
21596 @item @code{extra-options} (default: @code{'()})
21597 Additional arguments to pass to the @command{varnishd} process.
21602 @subsubheading Patchwork
21604 Patchwork is a patch tracking system. It can collect patches sent to a
21605 mailing list, and display them in a web interface.
21607 @defvr {Scheme Variable} patchwork-service-type
21608 Service type for Patchwork.
21611 The following example is an example of a minimal service for Patchwork, for
21612 the @code{patchwork.example.com} domain.
21615 (service patchwork-service-type
21616 (patchwork-configuration
21617 (domain "patchwork.example.com")
21619 (patchwork-settings-module
21620 (allowed-hosts (list domain))
21621 (default-from-email "patchwork@@patchwork.example.com")))
21622 (getmail-retriever-config
21623 (getmail-retriever-configuration
21624 (type "SimpleIMAPSSLRetriever")
21625 (server "imap.example.com")
21627 (username "patchwork")
21629 (list (file-append coreutils "/bin/cat")
21630 "/etc/getmail-patchwork-imap-password"))
21632 '((mailboxes . ("Patches"))))))))
21636 There are three records for configuring the Patchwork service. The
21637 @code{<patchwork-configuration>} relates to the configuration for Patchwork
21638 within the HTTPD service.
21640 The @code{settings-module} field within the @code{<patchwork-configuration>}
21641 record can be populated with the @code{<patchwork-settings-module>} record,
21642 which describes a settings module that is generated within the Guix store.
21644 For the @code{database-configuration} field within the
21645 @code{<patchwork-settings-module>}, the
21646 @code{<patchwork-database-configuration>} must be used.
21648 @deftp {Data Type} patchwork-configuration
21649 Data type representing the Patchwork service configuration. This type has the
21650 following parameters:
21653 @item @code{patchwork} (default: @code{patchwork})
21654 The Patchwork package to use.
21656 @item @code{domain}
21657 The domain to use for Patchwork, this is used in the HTTPD service virtual
21660 @item @code{settings-module}
21661 The settings module to use for Patchwork. As a Django application, Patchwork
21662 is configured with a Python module containing the settings. This can either be
21663 an instance of the @code{<patchwork-settings-module>} record, any other record
21664 that represents the settings in the store, or a directory outside of the
21667 @item @code{static-path} (default: @code{"/static/"})
21668 The path under which the HTTPD service should serve the static files.
21670 @item @code{getmail-retriever-config}
21671 The getmail-retriever-configuration record value to use with
21672 Patchwork. Getmail will be configured with this value, the messages will be
21673 delivered to Patchwork.
21678 @deftp {Data Type} patchwork-settings-module
21679 Data type representing a settings module for Patchwork. Some of these
21680 settings relate directly to Patchwork, but others relate to Django, the web
21681 framework used by Patchwork, or the Django Rest Framework library. This type
21682 has the following parameters:
21685 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
21686 The database connection settings used for Patchwork. See the
21687 @code{<patchwork-database-configuration>} record type for more information.
21689 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
21690 Patchwork, as a Django web application uses a secret key for cryptographically
21691 signing values. This file should contain a unique unpredictable value.
21693 If this file does not exist, it will be created and populated with a random
21694 value by the patchwork-setup shepherd service.
21696 This setting relates to Django.
21698 @item @code{allowed-hosts}
21699 A list of valid hosts for this Patchwork service. This should at least include
21700 the domain specified in the @code{<patchwork-configuration>} record.
21702 This is a Django setting.
21704 @item @code{default-from-email}
21705 The email address from which Patchwork should send email by default.
21707 This is a Patchwork setting.
21709 @item @code{static-url} (default: @code{#f})
21710 The URL to use when serving static assets. It can be part of a URL, or a full
21711 URL, but must end in a @code{/}.
21713 If the default value is used, the @code{static-path} value from the
21714 @code{<patchwork-configuration>} record will be used.
21716 This is a Django setting.
21718 @item @code{admins} (default: @code{'()})
21719 Email addresses to send the details of errors that occur. Each value should
21720 be a list containing two elements, the name and then the email address.
21722 This is a Django setting.
21724 @item @code{debug?} (default: @code{#f})
21725 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
21726 messages will be shown.
21728 This is a Django setting.
21730 @item @code{enable-rest-api?} (default: @code{#t})
21731 Whether to enable the Patchwork REST API.
21733 This is a Patchwork setting.
21735 @item @code{enable-xmlrpc?} (default: @code{#t})
21736 Whether to enable the XML RPC API.
21738 This is a Patchwork setting.
21740 @item @code{force-https-links?} (default: @code{#t})
21741 Whether to use HTTPS links on Patchwork pages.
21743 This is a Patchwork setting.
21745 @item @code{extra-settings} (default: @code{""})
21746 Extra code to place at the end of the Patchwork settings module.
21751 @deftp {Data Type} patchwork-database-configuration
21752 Data type representing the database configuration for Patchwork.
21755 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
21756 The database engine to use.
21758 @item @code{name} (default: @code{"patchwork"})
21759 The name of the database to use.
21761 @item @code{user} (default: @code{"httpd"})
21762 The user to connect to the database as.
21764 @item @code{password} (default: @code{""})
21765 The password to use when connecting to the database.
21767 @item @code{host} (default: @code{""})
21768 The host to make the database connection to.
21770 @item @code{port} (default: @code{""})
21771 The port on which to connect to the database.
21776 @subsubheading Mumi
21778 @cindex Mumi, Debbugs Web interface
21779 @cindex Debbugs, Mumi Web interface
21780 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
21781 Web interface to the Debbugs bug tracker, by default for
21782 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
21783 but it also fetches and indexes mail retrieved from Debbugs.
21785 @defvr {Scheme Variable} mumi-service-type
21786 This is the service type for Mumi.
21789 @deftp {Data Type} mumi-configuration
21790 Data type representing the Mumi service configuration. This type has the
21794 @item @code{mumi} (default: @code{mumi})
21795 The Mumi package to use.
21797 @item @code{mailer?} (default: @code{#true})
21798 Whether to enable or disable the mailer component.
21800 @item @code{mumi-configuration-sender}
21801 The email address used as the sender for comments.
21803 @item @code{mumi-configuration-smtp}
21804 A URI to configure the SMTP settings for Mailutils. This could be
21805 something like @code{sendmail:///path/to/bin/msmtp} or any other URI
21806 supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
21807 mailutils, GNU@tie{}Mailutils}.
21813 @subsubheading FastCGI
21816 FastCGI is an interface between the front-end and the back-end of a web
21817 service. It is a somewhat legacy facility; new web services should
21818 generally just talk HTTP between the front-end and the back-end.
21819 However there are a number of back-end services such as PHP or the
21820 optimized HTTP Git repository access that use FastCGI, so we have
21821 support for it in Guix.
21823 To use FastCGI, you configure the front-end web server (e.g., nginx) to
21824 dispatch some subset of its requests to the fastcgi backend, which
21825 listens on a local TCP or UNIX socket. There is an intermediary
21826 @code{fcgiwrap} program that sits between the actual backend process and
21827 the web server. The front-end indicates which backend program to run,
21828 passing that information to the @code{fcgiwrap} process.
21830 @defvr {Scheme Variable} fcgiwrap-service-type
21831 A service type for the @code{fcgiwrap} FastCGI proxy.
21834 @deftp {Data Type} fcgiwrap-configuration
21835 Data type representing the configuration of the @code{fcgiwrap} service.
21836 This type has the following parameters:
21838 @item @code{package} (default: @code{fcgiwrap})
21839 The fcgiwrap package to use.
21841 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
21842 The socket on which the @code{fcgiwrap} process should listen, as a
21843 string. Valid @var{socket} values include
21844 @code{unix:@var{/path/to/unix/socket}},
21845 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
21846 @code{tcp6:[@var{ipv6_addr}]:port}.
21848 @item @code{user} (default: @code{fcgiwrap})
21849 @itemx @code{group} (default: @code{fcgiwrap})
21850 The user and group names, as strings, under which to run the
21851 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
21852 the user asks for the specific user or group names @code{fcgiwrap} that
21853 the corresponding user and/or group is present on the system.
21855 It is possible to configure a FastCGI-backed web service to pass HTTP
21856 authentication information from the front-end to the back-end, and to
21857 allow @code{fcgiwrap} to run the back-end process as a corresponding
21858 local user. To enable this capability on the back-end, run
21859 @code{fcgiwrap} as the @code{root} user and group. Note that this
21860 capability also has to be configured on the front-end as well.
21865 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
21866 with some additional features useful for sites of any size.
21868 These features include:
21870 @item Adaptive process spawning
21871 @item Basic statistics (similar to Apache's mod_status)
21872 @item Advanced process management with graceful stop/start
21873 @item Ability to start workers with different uid/gid/chroot/environment
21874 and different php.ini (replaces safe_mode)
21875 @item Stdout & stderr logging
21876 @item Emergency restart in case of accidental opcode cache destruction
21877 @item Accelerated upload support
21878 @item Support for a "slowlog"
21879 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
21880 a special function to finish request & flush all data while continuing to do
21881 something time-consuming (video converting, stats processing, etc.)
21883 ...@: and much more.
21885 @defvr {Scheme Variable} php-fpm-service-type
21886 A Service type for @code{php-fpm}.
21889 @deftp {Data Type} php-fpm-configuration
21890 Data Type for php-fpm service configuration.
21892 @item @code{php} (default: @code{php})
21893 The php package to use.
21894 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
21895 The address on which to accept FastCGI requests. Valid syntaxes are:
21897 @item @code{"ip.add.re.ss:port"}
21898 Listen on a TCP socket to a specific address on a specific port.
21899 @item @code{"port"}
21900 Listen on a TCP socket to all addresses on a specific port.
21901 @item @code{"/path/to/unix/socket"}
21902 Listen on a unix socket.
21905 @item @code{user} (default: @code{php-fpm})
21906 User who will own the php worker processes.
21907 @item @code{group} (default: @code{php-fpm})
21908 Group of the worker processes.
21909 @item @code{socket-user} (default: @code{php-fpm})
21910 User who can speak to the php-fpm socket.
21911 @item @code{socket-group} (default: @code{nginx})
21912 Group that can speak to the php-fpm socket.
21913 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
21914 The process id of the php-fpm process is written to this file
21915 once the service has started.
21916 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
21917 Log for the php-fpm master process.
21918 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
21919 Detailed settings for the php-fpm process manager.
21922 @item @code{<php-fpm-dynamic-process-manager-configuration>}
21923 @item @code{<php-fpm-static-process-manager-configuration>}
21924 @item @code{<php-fpm-on-demand-process-manager-configuration>}
21926 @item @code{display-errors} (default @code{#f})
21927 Determines whether php errors and warning should be sent to clients
21928 and displayed in their browsers.
21929 This is useful for local php development, but a security risk for public sites,
21930 as error messages can reveal passwords and personal data.
21931 @item @code{timezone} (default @code{#f})
21932 Specifies @code{php_admin_value[date.timezone]} parameter.
21933 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
21934 This file will log the @code{stderr} outputs of php worker processes.
21935 Can be set to @code{#f} to disable logging.
21936 @item @code{file} (default @code{#f})
21937 An optional override of the whole configuration.
21938 You can use the @code{mixed-text-file} function or an absolute filepath for it.
21942 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
21943 Data Type for the @code{dynamic} php-fpm process manager. With the
21944 @code{dynamic} process manager, spare worker processes are kept around
21945 based on it's configured limits.
21947 @item @code{max-children} (default: @code{5})
21948 Maximum of worker processes.
21949 @item @code{start-servers} (default: @code{2})
21950 How many worker processes should be started on start-up.
21951 @item @code{min-spare-servers} (default: @code{1})
21952 How many spare worker processes should be kept around at minimum.
21953 @item @code{max-spare-servers} (default: @code{3})
21954 How many spare worker processes should be kept around at maximum.
21958 @deftp {Data type} php-fpm-static-process-manager-configuration
21959 Data Type for the @code{static} php-fpm process manager. With the
21960 @code{static} process manager, an unchanging number of worker processes
21963 @item @code{max-children} (default: @code{5})
21964 Maximum of worker processes.
21968 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
21969 Data Type for the @code{on-demand} php-fpm process manager. With the
21970 @code{on-demand} process manager, worker processes are only created as
21973 @item @code{max-children} (default: @code{5})
21974 Maximum of worker processes.
21975 @item @code{process-idle-timeout} (default: @code{10})
21976 The time in seconds after which a process with no requests is killed.
21981 @deffn {Scheme Procedure} nginx-php-location @
21982 [#:nginx-package nginx] @
21983 [socket (string-append "/var/run/php" @
21984 (version-major (package-version php)) @
21986 A helper function to quickly add php to an @code{nginx-server-configuration}.
21989 A simple services setup for nginx with php can look like this:
21991 (services (cons* (service dhcp-client-service-type)
21992 (service php-fpm-service-type)
21993 (service nginx-service-type
21994 (nginx-server-configuration
21995 (server-name '("example.com"))
21996 (root "/srv/http/")
21998 (list (nginx-php-location)))
22000 (ssl-certificate #f)
22001 (ssl-certificate-key #f)))
22005 @cindex cat-avatar-generator
22006 The cat avatar generator is a simple service to demonstrate the use of php-fpm
22007 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
22008 the hash of a user's email address.
22010 @deffn {Scheme Procedure} cat-avatar-generator-service @
22011 [#:cache-dir "/var/cache/cat-avatar-generator"] @
22012 [#:package cat-avatar-generator] @
22013 [#:configuration (nginx-server-configuration)]
22014 Returns an nginx-server-configuration that inherits @code{configuration}. It
22015 extends the nginx configuration to add a server block that serves @code{package},
22016 a version of cat-avatar-generator. During execution, cat-avatar-generator will
22017 be able to use @code{cache-dir} as its cache directory.
22020 A simple setup for cat-avatar-generator can look like this:
22022 (services (cons* (cat-avatar-generator-service
22024 (nginx-server-configuration
22025 (server-name '("example.com"))))
22030 @subsubheading Hpcguix-web
22032 @cindex hpcguix-web
22033 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
22034 program is a customizable web interface to browse Guix packages,
22035 initially designed for users of high-performance computing (HPC)
22038 @defvr {Scheme Variable} hpcguix-web-service-type
22039 The service type for @code{hpcguix-web}.
22042 @deftp {Data Type} hpcguix-web-configuration
22043 Data type for the hpcguix-web service configuration.
22047 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
22048 configuration. The main items available in this spec are:
22051 @item @code{title-prefix} (default: @code{"hpcguix | "})
22052 The page title prefix.
22054 @item @code{guix-command} (default: @code{"guix"})
22055 The @command{guix} command.
22057 @item @code{package-filter-proc} (default: @code{(const #t)})
22058 A procedure specifying how to filter packages that are displayed.
22060 @item @code{package-page-extension-proc} (default: @code{(const '())})
22061 Extension package for @code{hpcguix-web}.
22063 @item @code{menu} (default: @code{'()})
22064 Additional entry in page @code{menu}.
22066 @item @code{channels} (default: @code{%default-channels})
22067 List of channels from which the package list is built (@pxref{Channels}).
22069 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
22070 The expiration time, in seconds, after which the package list is rebuilt from
22071 the latest instances of the given channels.
22074 See the hpcguix-web repository for a
22075 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
22078 @item @code{package} (default: @code{hpcguix-web})
22079 The hpcguix-web package to use.
22083 A typical hpcguix-web service declaration looks like this:
22086 (service hpcguix-web-service-type
22087 (hpcguix-web-configuration
22089 #~(define site-config
22090 (hpcweb-configuration
22091 (title-prefix "Guix-HPC - ")
22092 (menu '(("/about" "ABOUT"))))))))
22096 The hpcguix-web service periodically updates the package list it publishes by
22097 pulling channels from Git. To that end, it needs to access X.509 certificates
22098 so that it can authenticate Git servers when communicating over HTTPS, and it
22099 assumes that @file{/etc/ssl/certs} contains those certificates.
22101 Thus, make sure to add @code{nss-certs} or another certificate package to the
22102 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
22103 more information on X.509 certificates.
22106 @node Certificate Services
22107 @subsection Certificate Services
22110 @cindex HTTP, HTTPS
22111 @cindex Let's Encrypt
22112 @cindex TLS certificates
22113 The @code{(gnu services certbot)} module provides a service to
22114 automatically obtain a valid TLS certificate from the Let's Encrypt
22115 certificate authority. These certificates can then be used to serve
22116 content securely over HTTPS or other TLS-based protocols, with the
22117 knowledge that the client will be able to verify the server's
22120 @url{https://letsencrypt.org/, Let's Encrypt} provides the
22121 @code{certbot} tool to automate the certification process. This tool
22122 first securely generates a key on the server. It then makes a request
22123 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
22124 checks that the request originates from the host in question by using a
22125 challenge-response protocol, requiring the server to provide its
22126 response over HTTP. If that protocol completes successfully, the CA
22127 signs the key, resulting in a certificate. That certificate is valid
22128 for a limited period of time, and therefore to continue to provide TLS
22129 services, the server needs to periodically ask the CA to renew its
22132 The certbot service automates this process: the initial key
22133 generation, the initial certification request to the Let's Encrypt
22134 service, the web server challenge/response integration, writing the
22135 certificate to disk, the automated periodic renewals, and the deployment
22136 tasks associated with the renewal (e.g.@: reloading services, copying keys
22137 with different permissions).
22139 Certbot is run twice a day, at a random minute within the hour. It
22140 won't do anything until your certificates are due for renewal or
22141 revoked, but running it regularly would give your service a chance of
22142 staying online in case a Let's Encrypt-initiated revocation happened for
22145 By using this service, you agree to the ACME Subscriber Agreement, which
22146 can be found there:
22147 @url{https://acme-v01.api.letsencrypt.org/directory}.
22149 @defvr {Scheme Variable} certbot-service-type
22150 A service type for the @code{certbot} Let's Encrypt client. Its value
22151 must be a @code{certbot-configuration} record as in this example:
22154 (define %nginx-deploy-hook
22156 "nginx-deploy-hook"
22157 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
22158 (kill pid SIGHUP))))
22160 (service certbot-service-type
22161 (certbot-configuration
22162 (email "foo@@example.net")
22165 (certificate-configuration
22166 (domains '("example.net" "www.example.net"))
22167 (deploy-hook %nginx-deploy-hook))
22168 (certificate-configuration
22169 (domains '("bar.example.net")))))))
22172 See below for details about @code{certbot-configuration}.
22175 @deftp {Data Type} certbot-configuration
22176 Data type representing the configuration of the @code{certbot} service.
22177 This type has the following parameters:
22180 @item @code{package} (default: @code{certbot})
22181 The certbot package to use.
22183 @item @code{webroot} (default: @code{/var/www})
22184 The directory from which to serve the Let's Encrypt challenge/response
22187 @item @code{certificates} (default: @code{()})
22188 A list of @code{certificates-configuration}s for which to generate
22189 certificates and request signatures. Each certificate has a @code{name}
22190 and several @code{domains}.
22193 Mandatory email used for registration, recovery contact, and important
22194 account notifications.
22196 @item @code{server} (default: @code{#f})
22197 Optional URL of ACME server. Setting this overrides certbot's default,
22198 which is the Let's Encrypt server.
22200 @item @code{rsa-key-size} (default: @code{2048})
22201 Size of the RSA key.
22203 @item @code{default-location} (default: @i{see below})
22204 The default @code{nginx-location-configuration}. Because @code{certbot}
22205 needs to be able to serve challenges and responses, it needs to be able
22206 to run a web server. It does so by extending the @code{nginx} web
22207 service with an @code{nginx-server-configuration} listening on the
22208 @var{domains} on port 80, and which has a
22209 @code{nginx-location-configuration} for the @code{/.well-known/} URI
22210 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
22211 these nginx configuration data types.
22213 Requests to other URL paths will be matched by the
22214 @code{default-location}, which if present is added to all
22215 @code{nginx-server-configuration}s.
22217 By default, the @code{default-location} will issue a redirect from
22218 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
22219 you to define what to serve on your site via @code{https}.
22221 Pass @code{#f} to not issue a default location.
22225 @deftp {Data Type} certificate-configuration
22226 Data type representing the configuration of a certificate.
22227 This type has the following parameters:
22230 @item @code{name} (default: @i{see below})
22231 This name is used by Certbot for housekeeping and in file paths; it
22232 doesn't affect the content of the certificate itself. To see
22233 certificate names, run @code{certbot certificates}.
22235 Its default is the first provided domain.
22237 @item @code{domains} (default: @code{()})
22238 The first domain provided will be the subject CN of the certificate, and
22239 all domains will be Subject Alternative Names on the certificate.
22241 @item @code{challenge} (default: @code{#f})
22242 The challenge type that has to be run by certbot. If @code{#f} is specified,
22243 default to the HTTP challenge. If a value is specified, defaults to the
22244 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
22245 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
22246 and gives Let's Encrypt permission to log the public IP address of the
22247 requesting machine.
22249 @item @code{authentication-hook} (default: @code{#f})
22250 Command to be run in a shell once for each certificate challenge to be
22251 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
22252 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
22253 contains the validation string and @code{$CERTBOT_TOKEN} contains the
22254 file name of the resource requested when performing an HTTP-01 challenge.
22256 @item @code{cleanup-hook} (default: @code{#f})
22257 Command to be run in a shell once for each certificate challenge that
22258 have been answered by the @code{auth-hook}. For this command, the shell
22259 variables available in the @code{auth-hook} script are still available, and
22260 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
22261 of the @code{auth-hook} script.
22263 @item @code{deploy-hook} (default: @code{#f})
22264 Command to be run in a shell once for each successfully issued
22265 certificate. For this command, the shell variable
22266 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
22267 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
22268 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
22269 contain a space-delimited list of renewed certificate domains (for
22270 example, @samp{"example.com www.example.com"}.
22275 For each @code{certificate-configuration}, the certificate is saved to
22276 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
22277 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
22279 @subsection DNS Services
22280 @cindex DNS (domain name system)
22281 @cindex domain name system (DNS)
22283 The @code{(gnu services dns)} module provides services related to the
22284 @dfn{domain name system} (DNS). It provides a server service for hosting
22285 an @emph{authoritative} DNS server for multiple zones, slave or master.
22286 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
22287 caching and forwarding DNS server for the LAN, which uses
22288 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
22290 @subsubheading Knot Service
22292 An example configuration of an authoritative server for two zones, one master
22296 (define-zone-entries example.org.zone
22297 ;; Name TTL Class Type Data
22298 ("@@" "" "IN" "A" "127.0.0.1")
22299 ("@@" "" "IN" "NS" "ns")
22300 ("ns" "" "IN" "A" "127.0.0.1"))
22302 (define master-zone
22303 (knot-zone-configuration
22304 (domain "example.org")
22306 (origin "example.org")
22307 (entries example.org.zone)))))
22310 (knot-zone-configuration
22311 (domain "plop.org")
22312 (dnssec-policy "default")
22313 (master (list "plop-master"))))
22315 (define plop-master
22316 (knot-remote-configuration
22318 (address (list "208.76.58.171"))))
22322 (services (cons* (service knot-service-type
22323 (knot-configuration
22324 (remotes (list plop-master))
22325 (zones (list master-zone slave-zone))))
22330 @deffn {Scheme Variable} knot-service-type
22331 This is the type for the Knot DNS server.
22333 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
22334 zones, that is to say domain names you would buy from a registrar. This server
22335 is not a resolver, meaning that it can only resolve names for which it is
22336 authoritative. This server can be configured to serve zones as a master server
22337 or a slave server as a per-zone basis. Slave zones will get their data from
22338 masters, and will serve it as an authoritative server. From the point of view
22339 of a resolver, there is no difference between master and slave.
22341 The following data types are used to configure the Knot DNS server:
22344 @deftp {Data Type} knot-key-configuration
22345 Data type representing a key.
22346 This type has the following parameters:
22349 @item @code{id} (default: @code{""})
22350 An identifier for other configuration fields to refer to this key. IDs must
22351 be unique and must not be empty.
22353 @item @code{algorithm} (default: @code{#f})
22354 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
22355 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
22356 and @code{'hmac-sha512}.
22358 @item @code{secret} (default: @code{""})
22359 The secret key itself.
22364 @deftp {Data Type} knot-acl-configuration
22365 Data type representing an Access Control List (ACL) configuration.
22366 This type has the following parameters:
22369 @item @code{id} (default: @code{""})
22370 An identifier for ether configuration fields to refer to this key. IDs must be
22371 unique and must not be empty.
22373 @item @code{address} (default: @code{'()})
22374 An ordered list of IP addresses, network subnets, or network ranges represented
22375 with strings. The query must match one of them. Empty value means that
22376 address match is not required.
22378 @item @code{key} (default: @code{'()})
22379 An ordered list of references to keys represented with strings. The string
22380 must match a key ID defined in a @code{knot-key-configuration}. No key means
22381 that a key is not require to match that ACL.
22383 @item @code{action} (default: @code{'()})
22384 An ordered list of actions that are permitted or forbidden by this ACL. Possible
22385 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
22386 and @code{'update}.
22388 @item @code{deny?} (default: @code{#f})
22389 When true, the ACL defines restrictions. Listed actions are forbidden. When
22390 false, listed actions are allowed.
22395 @deftp {Data Type} zone-entry
22396 Data type representing a record entry in a zone file.
22397 This type has the following parameters:
22400 @item @code{name} (default: @code{"@@"})
22401 The name of the record. @code{"@@"} refers to the origin of the zone. Names
22402 are relative to the origin of the zone. For example, in the @code{example.org}
22403 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
22404 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
22405 refers to @code{ns.example.org}.
22407 @item @code{ttl} (default: @code{""})
22408 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
22410 @item @code{class} (default: @code{"IN"})
22411 The class of the record. Knot currently supports only @code{"IN"} and
22412 partially @code{"CH"}.
22414 @item @code{type} (default: @code{"A"})
22415 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
22416 address), NS (Name Server) and MX (Mail eXchange). Many other types are
22419 @item @code{data} (default: @code{""})
22420 The data contained in the record. For instance an IP address associated with
22421 an A record, or a domain name associated with an NS record. Remember that
22422 domain names are relative to the origin unless they end with a dot.
22427 @deftp {Data Type} zone-file
22428 Data type representing the content of a zone file.
22429 This type has the following parameters:
22432 @item @code{entries} (default: @code{'()})
22433 The list of entries. The SOA record is taken care of, so you don't need to
22434 put it in the list of entries. This list should probably contain an entry
22435 for your primary authoritative DNS server. Other than using a list of entries
22436 directly, you can use @code{define-zone-entries} to define a object containing
22437 the list of entries more easily, that you can later pass to the @code{entries}
22438 field of the @code{zone-file}.
22440 @item @code{origin} (default: @code{""})
22441 The name of your zone. This parameter cannot be empty.
22443 @item @code{ns} (default: @code{"ns"})
22444 The domain of your primary authoritative DNS server. The name is relative to
22445 the origin, unless it ends with a dot. It is mandatory that this primary
22446 DNS server corresponds to an NS record in the zone and that it is associated
22447 to an IP address in the list of entries.
22449 @item @code{mail} (default: @code{"hostmaster"})
22450 An email address people can contact you at, as the owner of the zone. This
22451 is translated as @code{<mail>@@<origin>}.
22453 @item @code{serial} (default: @code{1})
22454 The serial number of the zone. As this is used to keep track of changes by
22455 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
22456 Always increment it when you make a change in your zone.
22458 @item @code{refresh} (default: @code{(* 2 24 3600)})
22459 The frequency at which slaves will do a zone transfer. This value is a number
22460 of seconds. It can be computed by multiplications or with
22461 @code{(string->duration)}.
22463 @item @code{retry} (default: @code{(* 15 60)})
22464 The period after which a slave will retry to contact its master when it fails
22465 to do so a first time.
22467 @item @code{expiry} (default: @code{(* 14 24 3600)})
22468 Default TTL of records. Existing records are considered correct for at most
22469 this amount of time. After this period, resolvers will invalidate their cache
22470 and check again that it still exists.
22472 @item @code{nx} (default: @code{3600})
22473 Default TTL of inexistant records. This delay is usually short because you want
22474 your new domains to reach everyone quickly.
22479 @deftp {Data Type} knot-remote-configuration
22480 Data type representing a remote configuration.
22481 This type has the following parameters:
22484 @item @code{id} (default: @code{""})
22485 An identifier for other configuration fields to refer to this remote. IDs must
22486 be unique and must not be empty.
22488 @item @code{address} (default: @code{'()})
22489 An ordered list of destination IP addresses. Addresses are tried in sequence.
22490 An optional port can be given with the @@ separator. For instance:
22491 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
22493 @item @code{via} (default: @code{'()})
22494 An ordered list of source IP addresses. An empty list will have Knot choose
22495 an appropriate source IP. An optional port can be given with the @@ separator.
22496 The default is to choose at random.
22498 @item @code{key} (default: @code{#f})
22499 A reference to a key, that is a string containing the identifier of a key
22500 defined in a @code{knot-key-configuration} field.
22505 @deftp {Data Type} knot-keystore-configuration
22506 Data type representing a keystore to hold dnssec keys.
22507 This type has the following parameters:
22510 @item @code{id} (default: @code{""})
22511 The id of the keystore. It must not be empty.
22513 @item @code{backend} (default: @code{'pem})
22514 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
22516 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
22517 The configuration string of the backend. An example for the PKCS#11 is:
22518 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
22519 For the pem backend, the string represents a path in the file system.
22524 @deftp {Data Type} knot-policy-configuration
22525 Data type representing a dnssec policy. Knot DNS is able to automatically
22526 sign your zones. It can either generate and manage your keys automatically or
22527 use keys that you generate.
22529 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
22530 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
22531 zone. In order to be trusted, the KSK needs to be present in the parent zone
22532 (usually a top-level domain). If your registrar supports dnssec, you will
22533 have to send them your KSK's hash so they can add a DS record in their zone.
22534 This is not automated and need to be done each time you change your KSK.
22536 The policy also defines the lifetime of keys. Usually, ZSK can be changed
22537 easily and use weaker cryptographic functions (they use lower parameters) in
22538 order to sign records quickly, so they are changed often. The KSK however
22539 requires manual interaction with the registrar, so they are changed less often
22540 and use stronger parameters because they sign only one record.
22542 This type has the following parameters:
22545 @item @code{id} (default: @code{""})
22546 The id of the policy. It must not be empty.
22548 @item @code{keystore} (default: @code{"default"})
22549 A reference to a keystore, that is a string containing the identifier of a
22550 keystore defined in a @code{knot-keystore-configuration} field. The
22551 @code{"default"} identifier means the default keystore (a kasp database that
22552 was setup by this service).
22554 @item @code{manual?} (default: @code{#f})
22555 Whether the key management is manual or automatic.
22557 @item @code{single-type-signing?} (default: @code{#f})
22558 When @code{#t}, use the Single-Type Signing Scheme.
22560 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
22561 An algorithm of signing keys and issued signatures.
22563 @item @code{ksk-size} (default: @code{256})
22564 The length of the KSK. Note that this value is correct for the default
22565 algorithm, but would be unsecure for other algorithms.
22567 @item @code{zsk-size} (default: @code{256})
22568 The length of the ZSK. Note that this value is correct for the default
22569 algorithm, but would be unsecure for other algorithms.
22571 @item @code{dnskey-ttl} (default: @code{'default})
22572 The TTL value for DNSKEY records added into zone apex. The special
22573 @code{'default} value means same as the zone SOA TTL.
22575 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
22576 The period between ZSK publication and the next rollover initiation.
22578 @item @code{propagation-delay} (default: @code{(* 24 3600)})
22579 An extra delay added for each key rollover step. This value should be high
22580 enough to cover propagation of data from the master server to all slaves.
22582 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
22583 A validity period of newly issued signatures.
22585 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
22586 A period how long before a signature expiration the signature will be refreshed.
22588 @item @code{nsec3?} (default: @code{#f})
22589 When @code{#t}, NSEC3 will be used instead of NSEC.
22591 @item @code{nsec3-iterations} (default: @code{5})
22592 The number of additional times the hashing is performed.
22594 @item @code{nsec3-salt-length} (default: @code{8})
22595 The length of a salt field in octets, which is appended to the original owner
22596 name before hashing.
22598 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
22599 The validity period of newly issued salt field.
22604 @deftp {Data Type} knot-zone-configuration
22605 Data type representing a zone served by Knot.
22606 This type has the following parameters:
22609 @item @code{domain} (default: @code{""})
22610 The domain served by this configuration. It must not be empty.
22612 @item @code{file} (default: @code{""})
22613 The file where this zone is saved. This parameter is ignored by master zones.
22614 Empty means default location that depends on the domain name.
22616 @item @code{zone} (default: @code{(zone-file)})
22617 The content of the zone file. This parameter is ignored by slave zones. It
22618 must contain a zone-file record.
22620 @item @code{master} (default: @code{'()})
22621 A list of master remotes. When empty, this zone is a master. When set, this
22622 zone is a slave. This is a list of remotes identifiers.
22624 @item @code{ddns-master} (default: @code{#f})
22625 The main master. When empty, it defaults to the first master in the list of
22628 @item @code{notify} (default: @code{'()})
22629 A list of slave remote identifiers.
22631 @item @code{acl} (default: @code{'()})
22632 A list of acl identifiers.
22634 @item @code{semantic-checks?} (default: @code{#f})
22635 When set, this adds more semantic checks to the zone.
22637 @item @code{disable-any?} (default: @code{#f})
22638 When set, this forbids queries of the ANY type.
22640 @item @code{zonefile-sync} (default: @code{0})
22641 The delay between a modification in memory and on disk. 0 means immediate
22644 @item @code{zonefile-load} (default: @code{#f})
22645 The way the zone file contents are applied during zone load. Possible values
22649 @item @code{#f} for using the default value from Knot,
22650 @item @code{'none} for not using the zone file at all,
22651 @item @code{'difference} for computing the difference between already available
22652 contents and zone contents and applying it to the current zone contents,
22653 @item @code{'difference-no-serial} for the same as @code{'difference}, but
22654 ignoring the SOA serial in the zone file, while the server takes care of it
22656 @item @code{'whole} for loading zone contents from the zone file.
22659 @item @code{journal-content} (default: @code{#f})
22660 The way the journal is used to store zone and its changes. Possible values
22661 are @code{'none} to not use it at all, @code{'changes} to store changes and
22662 @code{'all} to store contents. @code{#f} does not set this option, so the
22663 default value from Knot is used.
22665 @item @code{max-journal-usage} (default: @code{#f})
22666 The maximum size for the journal on disk. @code{#f} does not set this option,
22667 so the default value from Knot is used.
22669 @item @code{max-journal-depth} (default: @code{#f})
22670 The maximum size of the history. @code{#f} does not set this option, so the
22671 default value from Knot is used.
22673 @item @code{max-zone-size} (default: @code{#f})
22674 The maximum size of the zone file. This limit is enforced for incoming
22675 transfer and updates. @code{#f} does not set this option, so the default
22676 value from Knot is used.
22678 @item @code{dnssec-policy} (default: @code{#f})
22679 A reference to a @code{knot-policy-configuration} record, or the special
22680 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
22683 @item @code{serial-policy} (default: @code{'increment})
22684 A policy between @code{'increment} and @code{'unixtime}.
22689 @deftp {Data Type} knot-configuration
22690 Data type representing the Knot configuration.
22691 This type has the following parameters:
22694 @item @code{knot} (default: @code{knot})
22697 @item @code{run-directory} (default: @code{"/var/run/knot"})
22698 The run directory. This directory will be used for pid file and sockets.
22700 @item @code{includes} (default: @code{'()})
22701 A list of strings or file-like objects denoting other files that must be
22702 included at the top of the configuration file.
22704 @cindex secrets, Knot service
22705 This can be used to manage secrets out-of-band. For example, secret
22706 keys may be stored in an out-of-band file not managed by Guix, and
22707 thus not visible in @file{/gnu/store}---e.g., you could store secret
22708 key configuration in @file{/etc/knot/secrets.conf} and add this file
22709 to the @code{includes} list.
22711 One can generate a secret tsig key (for nsupdate and zone transfers with the
22712 keymgr command from the knot package. Note that the package is not automatically
22713 installed by the service. The following example shows how to generate a new
22717 keymgr -t mysecret > /etc/knot/secrets.conf
22718 chmod 600 /etc/knot/secrets.conf
22721 Also note that the generated key will be named @var{mysecret}, so it is the
22722 name that needs to be used in the @var{key} field of the
22723 @code{knot-acl-configuration} record and in other places that need to refer
22726 It can also be used to add configuration not supported by this interface.
22728 @item @code{listen-v4} (default: @code{"0.0.0.0"})
22729 An ip address on which to listen.
22731 @item @code{listen-v6} (default: @code{"::"})
22732 An ip address on which to listen.
22734 @item @code{listen-port} (default: @code{53})
22735 A port on which to listen.
22737 @item @code{keys} (default: @code{'()})
22738 The list of knot-key-configuration used by this configuration.
22740 @item @code{acls} (default: @code{'()})
22741 The list of knot-acl-configuration used by this configuration.
22743 @item @code{remotes} (default: @code{'()})
22744 The list of knot-remote-configuration used by this configuration.
22746 @item @code{zones} (default: @code{'()})
22747 The list of knot-zone-configuration used by this configuration.
22752 @subsubheading Knot Resolver Service
22754 @deffn {Scheme Variable} knot-resolver-service-type
22755 This this the type of the knot resolver service, whose value should be
22756 an @code{knot-resolver-configuration} object as in this example:
22759 (service knot-resolver-service-type
22760 (knot-resolver-configuration
22761 (kresd-config-file (plain-file "kresd.conf" "
22762 net.listen('192.168.0.1', 5353)
22763 user('knot-resolver', 'knot-resolver')
22764 modules = @{ 'hints > iterate', 'stats', 'predict' @}
22765 cache.size = 100 * MB
22769 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
22772 @deftp {Data Type} knot-resolver-configuration
22773 Data type representing the configuration of knot-resolver.
22776 @item @code{package} (default: @var{knot-resolver})
22777 Package object of the knot DNS resolver.
22779 @item @code{kresd-config-file} (default: %kresd.conf)
22780 File-like object of the kresd configuration file to use, by default it
22781 will listen on @code{127.0.0.1} and @code{::1}.
22783 @item @code{garbage-collection-interval} (default: 1000)
22784 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
22790 @subsubheading Dnsmasq Service
22792 @deffn {Scheme Variable} dnsmasq-service-type
22793 This is the type of the dnsmasq service, whose value should be an
22794 @code{dnsmasq-configuration} object as in this example:
22797 (service dnsmasq-service-type
22798 (dnsmasq-configuration
22800 (servers '("192.168.1.1"))))
22804 @deftp {Data Type} dnsmasq-configuration
22805 Data type representing the configuration of dnsmasq.
22808 @item @code{package} (default: @var{dnsmasq})
22809 Package object of the dnsmasq server.
22811 @item @code{no-hosts?} (default: @code{#f})
22812 When true, don't read the hostnames in /etc/hosts.
22814 @item @code{port} (default: @code{53})
22815 The port to listen on. Setting this to zero completely disables DNS
22816 responses, leaving only DHCP and/or TFTP functions.
22818 @item @code{local-service?} (default: @code{#t})
22819 Accept DNS queries only from hosts whose address is on a local subnet,
22820 ie a subnet for which an interface exists on the server.
22822 @item @code{listen-addresses} (default: @code{'()})
22823 Listen on the given IP addresses.
22825 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
22826 The file to read the IP address of the upstream nameservers from.
22828 @item @code{no-resolv?} (default: @code{#f})
22829 When true, don't read @var{resolv-file}.
22831 @item @code{servers} (default: @code{'()})
22832 Specify IP address of upstream servers directly.
22834 @item @code{addresses} (default: @code{'()})
22835 For each entry, specify an IP address to return for any host in the
22836 given domains. Queries in the domains are never forwarded and always
22837 replied to with the specified IP address.
22839 This is useful for redirecting hosts locally, for example:
22842 (service dnsmasq-service-type
22843 (dnsmasq-configuration
22845 '(; Redirect to a local web-server.
22846 "/example.org/127.0.0.1"
22847 ; Redirect subdomain to a specific IP.
22848 "/subdomain.example.org/192.168.1.42"))))
22851 Note that rules in @file{/etc/hosts} take precedence over this.
22853 @item @code{cache-size} (default: @code{150})
22854 Set the size of dnsmasq's cache. Setting the cache size to zero
22857 @item @code{negative-cache?} (default: @code{#t})
22858 When false, disable negative caching.
22863 @subsubheading ddclient Service
22866 The ddclient service described below runs the ddclient daemon, which takes
22867 care of automatically updating DNS entries for service providers such as
22868 @uref{https://dyn.com/dns/, Dyn}.
22870 The following example show instantiates the service with its default
22874 (service ddclient-service-type)
22877 Note that ddclient needs to access credentials that are stored in a
22878 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
22879 @code{secret-file} below). You are expected to create this file manually, in
22880 an ``out-of-band'' fashion (you @emph{could} make this file part of the
22881 service configuration, for instance by using @code{plain-file}, but it will be
22882 world-readable @i{via} @file{/gnu/store}). See the examples in the
22883 @file{share/ddclient} directory of the @code{ddclient} package.
22885 @c %start of fragment
22887 Available @code{ddclient-configuration} fields are:
22889 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
22890 The ddclient package.
22894 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
22895 The period after which ddclient will retry to check IP and domain name.
22897 Defaults to @samp{300}.
22901 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
22902 Use syslog for the output.
22904 Defaults to @samp{#t}.
22908 @deftypevr {@code{ddclient-configuration} parameter} string mail
22911 Defaults to @samp{"root"}.
22915 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
22916 Mail failed update to user.
22918 Defaults to @samp{"root"}.
22922 @deftypevr {@code{ddclient-configuration} parameter} string pid
22923 The ddclient PID file.
22925 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
22929 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
22930 Enable SSL support.
22932 Defaults to @samp{#t}.
22936 @deftypevr {@code{ddclient-configuration} parameter} string user
22937 Specifies the user name or ID that is used when running ddclient
22940 Defaults to @samp{"ddclient"}.
22944 @deftypevr {@code{ddclient-configuration} parameter} string group
22945 Group of the user who will run the ddclient program.
22947 Defaults to @samp{"ddclient"}.
22951 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
22952 Secret file which will be appended to @file{ddclient.conf} file. This
22953 file contains credentials for use by ddclient. You are expected to
22954 create it manually.
22956 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
22960 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
22961 Extra options will be appended to @file{ddclient.conf} file.
22963 Defaults to @samp{()}.
22968 @c %end of fragment
22972 @subsection VPN Services
22973 @cindex VPN (virtual private network)
22974 @cindex virtual private network (VPN)
22976 The @code{(gnu services vpn)} module provides services related to
22977 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
22978 your machine to connect to a VPN, and a @emph{server} service for your machine
22979 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
22981 @deffn {Scheme Procedure} openvpn-client-service @
22982 [#:config (openvpn-client-configuration)]
22984 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
22987 @deffn {Scheme Procedure} openvpn-server-service @
22988 [#:config (openvpn-server-configuration)]
22990 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
22992 Both can be run simultaneously.
22995 @c %automatically generated documentation
22997 Available @code{openvpn-client-configuration} fields are:
22999 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
23000 The OpenVPN package.
23004 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
23005 The OpenVPN pid file.
23007 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
23011 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
23012 The protocol (UDP or TCP) used to open a channel between clients and
23015 Defaults to @samp{udp}.
23019 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
23020 The device type used to represent the VPN connection.
23022 Defaults to @samp{tun}.
23026 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
23027 The certificate authority to check connections against.
23029 Defaults to @samp{"/etc/openvpn/ca.crt"}.
23033 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
23034 The certificate of the machine the daemon is running on. It should be
23035 signed by the authority given in @code{ca}.
23037 Defaults to @samp{"/etc/openvpn/client.crt"}.
23041 @deftypevr {@code{openvpn-client-configuration} parameter} string key
23042 The key of the machine the daemon is running on. It must be the key whose
23043 certificate is @code{cert}.
23045 Defaults to @samp{"/etc/openvpn/client.key"}.
23049 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
23050 Whether to use the lzo compression algorithm.
23052 Defaults to @samp{#t}.
23056 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
23057 Don't re-read key files across SIGUSR1 or --ping-restart.
23059 Defaults to @samp{#t}.
23063 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
23064 Don't close and reopen TUN/TAP device or run up/down scripts across
23065 SIGUSR1 or --ping-restart restarts.
23067 Defaults to @samp{#t}.
23071 @deftypevr {@code{openvpn-client-configuration} parameter} boolean fast-io?
23072 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
23073 poll/epoll/select prior to the write operation.
23075 Defaults to @samp{#f}.
23078 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
23081 Defaults to @samp{3}.
23085 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
23086 Add an additional layer of HMAC authentication on top of the TLS control
23087 channel to protect against DoS attacks.
23089 Defaults to @samp{#f}.
23093 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string auth-user-pass
23094 Authenticate with server using username/password. The option is a file
23095 containing username/password on 2 lines. Do not use a file-like object as it
23096 would be added to the store and readable by any user.
23098 Defaults to @samp{'disabled}.
23101 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
23102 Whether to check the server certificate has server usage extension.
23104 Defaults to @samp{#t}.
23108 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
23109 Bind to a specific local port number.
23111 Defaults to @samp{#f}.
23115 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
23116 Retry resolving server address.
23118 Defaults to @samp{#t}.
23122 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
23123 A list of remote servers to connect to.
23125 Defaults to @samp{()}.
23127 Available @code{openvpn-remote-configuration} fields are:
23129 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
23132 Defaults to @samp{"my-server"}.
23136 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
23137 Port number the server listens to.
23139 Defaults to @samp{1194}.
23144 @c %end of automatic openvpn-client documentation
23146 @c %automatically generated documentation
23148 Available @code{openvpn-server-configuration} fields are:
23150 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
23151 The OpenVPN package.
23155 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
23156 The OpenVPN pid file.
23158 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
23162 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
23163 The protocol (UDP or TCP) used to open a channel between clients and
23166 Defaults to @samp{udp}.
23170 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
23171 The device type used to represent the VPN connection.
23173 Defaults to @samp{tun}.
23177 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
23178 The certificate authority to check connections against.
23180 Defaults to @samp{"/etc/openvpn/ca.crt"}.
23184 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
23185 The certificate of the machine the daemon is running on. It should be
23186 signed by the authority given in @code{ca}.
23188 Defaults to @samp{"/etc/openvpn/client.crt"}.
23192 @deftypevr {@code{openvpn-server-configuration} parameter} string key
23193 The key of the machine the daemon is running on. It must be the key whose
23194 certificate is @code{cert}.
23196 Defaults to @samp{"/etc/openvpn/client.key"}.
23200 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
23201 Whether to use the lzo compression algorithm.
23203 Defaults to @samp{#t}.
23207 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
23208 Don't re-read key files across SIGUSR1 or --ping-restart.
23210 Defaults to @samp{#t}.
23214 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
23215 Don't close and reopen TUN/TAP device or run up/down scripts across
23216 SIGUSR1 or --ping-restart restarts.
23218 Defaults to @samp{#t}.
23222 @deftypevr {@code{openvpn-server-configuration} parameter} boolean fast-io?
23223 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
23224 poll/epoll/select prior to the write operation.
23226 Defaults to @samp{#f}.
23229 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
23232 Defaults to @samp{3}.
23236 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
23237 Add an additional layer of HMAC authentication on top of the TLS control
23238 channel to protect against DoS attacks.
23240 Defaults to @samp{#f}.
23244 @deftypevr {@code{openvpn-server-configuration} parameter} number port
23245 Specifies the port number on which the server listens.
23247 Defaults to @samp{1194}.
23251 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
23252 An ip and mask specifying the subnet inside the virtual network.
23254 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
23258 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
23259 A CIDR notation specifying the IPv6 subnet inside the virtual network.
23261 Defaults to @samp{#f}.
23265 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
23266 The Diffie-Hellman parameters file.
23268 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
23272 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
23273 The file that records client IPs.
23275 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
23279 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
23280 When true, the server will act as a gateway for its clients.
23282 Defaults to @samp{#f}.
23286 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
23287 When true, clients are allowed to talk to each other inside the VPN.
23289 Defaults to @samp{#f}.
23293 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
23294 Causes ping-like messages to be sent back and forth over the link so
23295 that each side knows when the other side has gone down. @code{keepalive}
23296 requires a pair. The first element is the period of the ping sending,
23297 and the second element is the timeout before considering the other side
23302 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
23303 The maximum number of clients.
23305 Defaults to @samp{100}.
23309 @deftypevr {@code{openvpn-server-configuration} parameter} string status
23310 The status file. This file shows a small report on current connection.
23311 It is truncated and rewritten every minute.
23313 Defaults to @samp{"/var/run/openvpn/status"}.
23317 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
23318 The list of configuration for some clients.
23320 Defaults to @samp{()}.
23322 Available @code{openvpn-ccd-configuration} fields are:
23324 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
23327 Defaults to @samp{"client"}.
23331 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
23334 Defaults to @samp{#f}.
23338 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
23341 Defaults to @samp{#f}.
23348 @c %end of automatic openvpn-server documentation
23351 @node Network File System
23352 @subsection Network File System
23355 The @code{(gnu services nfs)} module provides the following services,
23356 which are most commonly used in relation to mounting or exporting
23357 directory trees as @dfn{network file systems} (NFS).
23359 While it is possible to use the individual components that together make
23360 up a Network File System service, we recommended to configure an NFS
23361 server with the @code{nfs-service-type}.
23363 @subsubheading NFS Service
23364 @cindex NFS, server
23366 The NFS service takes care of setting up all NFS component services,
23367 kernel configuration file systems, and installs configuration files in
23368 the locations that NFS expects.
23370 @defvr {Scheme Variable} nfs-service-type
23371 A service type for a complete NFS server.
23374 @deftp {Data Type} nfs-configuration
23375 This data type represents the configuration of the NFS service and all
23378 It has the following parameters:
23380 @item @code{nfs-utils} (default: @code{nfs-utils})
23381 The nfs-utils package to use.
23383 @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
23384 If a list of string values is provided, the @command{rpc.nfsd} daemon
23385 will be limited to supporting the given versions of the NFS protocol.
23387 @item @code{exports} (default: @code{'()})
23388 This is a list of directories the NFS server should export. Each entry
23389 is a list consisting of two elements: a directory name and a string
23390 containing all options. This is an example in which the directory
23391 @file{/export} is served to all NFS clients as a read-only share:
23397 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
23400 @item @code{rpcmountd-port} (default: @code{#f})
23401 The network port that the @command{rpc.mountd} daemon should use.
23403 @item @code{rpcstatd-port} (default: @code{#f})
23404 The network port that the @command{rpc.statd} daemon should use.
23406 @item @code{rpcbind} (default: @code{rpcbind})
23407 The rpcbind package to use.
23409 @item @code{idmap-domain} (default: @code{"localdomain"})
23410 The local NFSv4 domain name.
23412 @item @code{nfsd-port} (default: @code{2049})
23413 The network port that the @command{nfsd} daemon should use.
23415 @item @code{nfsd-threads} (default: @code{8})
23416 The number of threads used by the @command{nfsd} daemon.
23418 @item @code{nfsd-tcp?} (default: @code{#t})
23419 Whether the @command{nfsd} daemon should listen on a TCP socket.
23421 @item @code{nfsd-udp?} (default: @code{#f})
23422 Whether the @command{nfsd} daemon should listen on a UDP socket.
23424 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23425 The directory where the pipefs file system is mounted.
23427 @item @code{debug} (default: @code{'()"})
23428 A list of subsystems for which debugging output should be enabled. This
23429 is a list of symbols. Any of these symbols are valid: @code{nfsd},
23430 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
23434 If you don't need a complete NFS service or prefer to build it yourself
23435 you can use the individual component services that are documented below.
23437 @subsubheading RPC Bind Service
23440 The RPC Bind service provides a facility to map program numbers into
23441 universal addresses.
23442 Many NFS related services use this facility. Hence it is automatically
23443 started when a dependent service starts.
23445 @defvr {Scheme Variable} rpcbind-service-type
23446 A service type for the RPC portmapper daemon.
23450 @deftp {Data Type} rpcbind-configuration
23451 Data type representing the configuration of the RPC Bind Service.
23452 This type has the following parameters:
23454 @item @code{rpcbind} (default: @code{rpcbind})
23455 The rpcbind package to use.
23457 @item @code{warm-start?} (default: @code{#t})
23458 If this parameter is @code{#t}, then the daemon will read a
23459 state file on startup thus reloading state information saved by a previous
23465 @subsubheading Pipefs Pseudo File System
23469 The pipefs file system is used to transfer NFS related data
23470 between the kernel and user space programs.
23472 @defvr {Scheme Variable} pipefs-service-type
23473 A service type for the pipefs pseudo file system.
23476 @deftp {Data Type} pipefs-configuration
23477 Data type representing the configuration of the pipefs pseudo file system service.
23478 This type has the following parameters:
23480 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23481 The directory to which the file system is to be attached.
23486 @subsubheading GSS Daemon Service
23489 @cindex global security system
23491 The @dfn{global security system} (GSS) daemon provides strong security for RPC
23493 Before exchanging RPC requests an RPC client must establish a security
23494 context. Typically this is done using the Kerberos command @command{kinit}
23495 or automatically at login time using PAM services (@pxref{Kerberos Services}).
23497 @defvr {Scheme Variable} gss-service-type
23498 A service type for the Global Security System (GSS) daemon.
23501 @deftp {Data Type} gss-configuration
23502 Data type representing the configuration of the GSS daemon service.
23503 This type has the following parameters:
23505 @item @code{nfs-utils} (default: @code{nfs-utils})
23506 The package in which the @command{rpc.gssd} command is to be found.
23508 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23509 The directory where the pipefs file system is mounted.
23515 @subsubheading IDMAP Daemon Service
23517 @cindex name mapper
23519 The idmap daemon service provides mapping between user IDs and user names.
23520 Typically it is required in order to access file systems mounted via NFSv4.
23522 @defvr {Scheme Variable} idmap-service-type
23523 A service type for the Identity Mapper (IDMAP) daemon.
23526 @deftp {Data Type} idmap-configuration
23527 Data type representing the configuration of the IDMAP daemon service.
23528 This type has the following parameters:
23530 @item @code{nfs-utils} (default: @code{nfs-utils})
23531 The package in which the @command{rpc.idmapd} command is to be found.
23533 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23534 The directory where the pipefs file system is mounted.
23536 @item @code{domain} (default: @code{#f})
23537 The local NFSv4 domain name.
23538 This must be a string or @code{#f}.
23539 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
23541 @item @code{verbosity} (default: @code{0})
23542 The verbosity level of the daemon.
23547 @node Continuous Integration
23548 @subsection Continuous Integration
23550 @cindex continuous integration
23551 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
23552 continuous integration tool for Guix. It can be used both for development and
23553 for providing substitutes to others (@pxref{Substitutes}).
23555 The @code{(gnu services cuirass)} module provides the following service.
23557 @defvr {Scheme Procedure} cuirass-service-type
23558 The type of the Cuirass service. Its value must be a
23559 @code{cuirass-configuration} object, as described below.
23562 To add build jobs, you have to set the @code{specifications} field of the
23563 configuration. Here is an example of a service that polls the Guix repository
23564 and builds the packages from a manifest. Some of the packages are defined in
23565 the @code{"custom-packages"} input, which is the equivalent of
23566 @env{GUIX_PACKAGE_PATH}.
23569 (define %cuirass-specs
23571 '((#:name . "my-manifest")
23572 (#:load-path-inputs . ("guix"))
23573 (#:package-path-inputs . ("custom-packages"))
23574 (#:proc-input . "guix")
23575 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
23576 (#:proc . cuirass-jobs)
23577 (#:proc-args . ((subset . "manifests")
23578 (systems . ("x86_64-linux"))
23579 (manifests . (("config" . "guix/manifest.scm")))))
23580 (#:inputs . (((#:name . "guix")
23581 (#:url . "git://git.savannah.gnu.org/guix.git")
23582 (#:load-path . ".")
23583 (#:branch . "master")
23584 (#:no-compile? . #t))
23585 ((#:name . "config")
23586 (#:url . "https://git.example.org/config.git")
23587 (#:load-path . ".")
23588 (#:branch . "master")
23589 (#:no-compile? . #t))
23590 ((#:name . "custom-packages")
23591 (#:url . "https://git.example.org/custom-packages.git")
23592 (#:load-path . ".")
23593 (#:branch . "master")
23594 (#:no-compile? . #t)))))))
23596 (service cuirass-service-type
23597 (cuirass-configuration
23598 (specifications %cuirass-specs)))
23601 While information related to build jobs is located directly in the
23602 specifications, global settings for the @command{cuirass} process are
23603 accessible in other @code{cuirass-configuration} fields.
23605 @deftp {Data Type} cuirass-configuration
23606 Data type representing the configuration of Cuirass.
23609 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
23610 Location of the log file.
23612 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
23613 Location of the log file used by the web interface.
23615 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
23616 Location of the repository cache.
23618 @item @code{user} (default: @code{"cuirass"})
23619 Owner of the @code{cuirass} process.
23621 @item @code{group} (default: @code{"cuirass"})
23622 Owner's group of the @code{cuirass} process.
23624 @item @code{interval} (default: @code{60})
23625 Number of seconds between the poll of the repositories followed by the
23628 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
23629 Location of sqlite database which contains the build results and previously
23630 added specifications.
23632 @item @code{ttl} (default: @code{(* 30 24 3600)})
23633 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
23634 are registered for build results. This means that build results are protected
23635 from garbage collection for at least @var{ttl} seconds.
23637 @item @code{port} (default: @code{8081})
23638 Port number used by the HTTP server.
23640 @item @code{host} (default: @code{"localhost"})
23641 Listen on the network interface for @var{host}. The default is to
23642 accept connections from localhost.
23644 @item @code{specifications} (default: @code{#~'()})
23645 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
23646 where a specification is an association list
23647 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
23648 keys are keywords (@code{#:keyword-example}) as shown in the example
23651 @item @code{use-substitutes?} (default: @code{#f})
23652 This allows using substitutes to avoid building every dependencies of a job
23655 @item @code{one-shot?} (default: @code{#f})
23656 Only evaluate specifications and build derivations once.
23658 @item @code{fallback?} (default: @code{#f})
23659 When substituting a pre-built binary fails, fall back to building
23662 @item @code{extra-options} (default: @code{'()})
23663 Extra options to pass when running the Cuirass processes.
23665 @item @code{cuirass} (default: @code{cuirass})
23666 The Cuirass package to use.
23670 @node Power Management Services
23671 @subsection Power Management Services
23674 @cindex power management with TLP
23675 @subsubheading TLP daemon
23677 The @code{(gnu services pm)} module provides a Guix service definition
23678 for the Linux power management tool TLP.
23680 TLP enables various powersaving modes in userspace and kernel.
23681 Contrary to @code{upower-service}, it is not a passive,
23682 monitoring tool, as it will apply custom settings each time a new power
23683 source is detected. More information can be found at
23684 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
23686 @deffn {Scheme Variable} tlp-service-type
23687 The service type for the TLP tool. The default settings are optimised
23688 for battery life on most systems, but you can tweak them to your heart's
23689 content by adding a valid @code{tlp-configuration}:
23691 (service tlp-service-type
23693 (cpu-scaling-governor-on-ac (list "performance"))
23694 (sched-powersave-on-bat? #t)))
23698 Each parameter definition is preceded by its type; for example,
23699 @samp{boolean foo} indicates that the @code{foo} parameter
23700 should be specified as a boolean. Types starting with
23701 @code{maybe-} denote parameters that won't show up in TLP config file
23702 when their value is @code{'disabled}.
23704 @c The following documentation was initially generated by
23705 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
23706 @c documentation is better, so we shouldn't hesitate to edit below as
23707 @c needed. However if the change you want to make to this documentation
23708 @c can be done in an automated way, it's probably easier to change
23709 @c (generate-documentation) than to make it below and have to deal with
23710 @c the churn as TLP updates.
23712 Available @code{tlp-configuration} fields are:
23714 @deftypevr {@code{tlp-configuration} parameter} package tlp
23719 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
23720 Set to true if you wish to enable TLP.
23722 Defaults to @samp{#t}.
23726 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
23727 Default mode when no power supply can be detected. Alternatives are AC
23730 Defaults to @samp{"AC"}.
23734 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
23735 Number of seconds Linux kernel has to wait after the disk goes idle,
23736 before syncing on AC.
23738 Defaults to @samp{0}.
23742 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
23743 Same as @code{disk-idle-ac} but on BAT mode.
23745 Defaults to @samp{2}.
23749 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
23750 Dirty pages flushing periodicity, expressed in seconds.
23752 Defaults to @samp{15}.
23756 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
23757 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
23759 Defaults to @samp{60}.
23763 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
23764 CPU frequency scaling governor on AC mode. With intel_pstate driver,
23765 alternatives are powersave and performance. With acpi-cpufreq driver,
23766 alternatives are ondemand, powersave, performance and conservative.
23768 Defaults to @samp{disabled}.
23772 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
23773 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
23775 Defaults to @samp{disabled}.
23779 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
23780 Set the min available frequency for the scaling governor on AC.
23782 Defaults to @samp{disabled}.
23786 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
23787 Set the max available frequency for the scaling governor on AC.
23789 Defaults to @samp{disabled}.
23793 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
23794 Set the min available frequency for the scaling governor on BAT.
23796 Defaults to @samp{disabled}.
23800 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
23801 Set the max available frequency for the scaling governor on BAT.
23803 Defaults to @samp{disabled}.
23807 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
23808 Limit the min P-state to control the power dissipation of the CPU, in AC
23809 mode. Values are stated as a percentage of the available performance.
23811 Defaults to @samp{disabled}.
23815 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
23816 Limit the max P-state to control the power dissipation of the CPU, in AC
23817 mode. Values are stated as a percentage of the available performance.
23819 Defaults to @samp{disabled}.
23823 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
23824 Same as @code{cpu-min-perf-on-ac} on BAT mode.
23826 Defaults to @samp{disabled}.
23830 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
23831 Same as @code{cpu-max-perf-on-ac} on BAT mode.
23833 Defaults to @samp{disabled}.
23837 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
23838 Enable CPU turbo boost feature on AC mode.
23840 Defaults to @samp{disabled}.
23844 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
23845 Same as @code{cpu-boost-on-ac?} on BAT mode.
23847 Defaults to @samp{disabled}.
23851 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
23852 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
23853 used under light load conditions.
23855 Defaults to @samp{#f}.
23859 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
23860 Same as @code{sched-powersave-on-ac?} but on BAT mode.
23862 Defaults to @samp{#t}.
23866 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
23867 Enable Linux kernel NMI watchdog.
23869 Defaults to @samp{#f}.
23873 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
23874 For Linux kernels with PHC patch applied, change CPU voltages. An
23875 example value would be @samp{"F:V F:V F:V F:V"}.
23877 Defaults to @samp{disabled}.
23881 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
23882 Set CPU performance versus energy saving policy on AC. Alternatives are
23883 performance, normal, powersave.
23885 Defaults to @samp{"performance"}.
23889 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
23890 Same as @code{energy-perf-policy-ac} but on BAT mode.
23892 Defaults to @samp{"powersave"}.
23896 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
23901 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
23902 Hard disk advanced power management level.
23906 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
23907 Same as @code{disk-apm-bat} but on BAT mode.
23911 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
23912 Hard disk spin down timeout. One value has to be specified for each
23913 declared hard disk.
23915 Defaults to @samp{disabled}.
23919 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
23920 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
23922 Defaults to @samp{disabled}.
23926 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
23927 Select IO scheduler for disk devices. One value has to be specified for
23928 each declared hard disk. Example alternatives are cfq, deadline and
23931 Defaults to @samp{disabled}.
23935 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
23936 SATA aggressive link power management (ALPM) level. Alternatives are
23937 min_power, medium_power, max_performance.
23939 Defaults to @samp{"max_performance"}.
23943 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
23944 Same as @code{sata-linkpwr-ac} but on BAT mode.
23946 Defaults to @samp{"min_power"}.
23950 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
23951 Exclude specified SATA host devices for link power management.
23953 Defaults to @samp{disabled}.
23957 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
23958 Enable Runtime Power Management for AHCI controller and disks on AC
23961 Defaults to @samp{disabled}.
23965 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
23966 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
23968 Defaults to @samp{disabled}.
23972 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
23973 Seconds of inactivity before disk is suspended.
23975 Defaults to @samp{15}.
23979 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
23980 PCI Express Active State Power Management level. Alternatives are
23981 default, performance, powersave.
23983 Defaults to @samp{"performance"}.
23987 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
23988 Same as @code{pcie-aspm-ac} but on BAT mode.
23990 Defaults to @samp{"powersave"}.
23994 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
23995 Radeon graphics clock speed level. Alternatives are low, mid, high,
23998 Defaults to @samp{"high"}.
24002 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
24003 Same as @code{radeon-power-ac} but on BAT mode.
24005 Defaults to @samp{"low"}.
24009 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
24010 Radeon dynamic power management method (DPM). Alternatives are battery,
24013 Defaults to @samp{"performance"}.
24017 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
24018 Same as @code{radeon-dpm-state-ac} but on BAT mode.
24020 Defaults to @samp{"battery"}.
24024 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
24025 Radeon DPM performance level. Alternatives are auto, low, high.
24027 Defaults to @samp{"auto"}.
24031 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
24032 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
24034 Defaults to @samp{"auto"}.
24038 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
24039 Wifi power saving mode.
24041 Defaults to @samp{#f}.
24045 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
24046 Same as @code{wifi-power-ac?} but on BAT mode.
24048 Defaults to @samp{#t}.
24052 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
24053 Disable wake on LAN.
24055 Defaults to @samp{#t}.
24059 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
24060 Timeout duration in seconds before activating audio power saving on
24061 Intel HDA and AC97 devices. A value of 0 disables power saving.
24063 Defaults to @samp{0}.
24067 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
24068 Same as @code{sound-powersave-ac} but on BAT mode.
24070 Defaults to @samp{1}.
24074 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
24075 Disable controller in powersaving mode on Intel HDA devices.
24077 Defaults to @samp{#t}.
24081 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
24082 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
24083 powered on again by releasing (and reinserting) the eject lever or by
24084 pressing the disc eject button on newer models.
24086 Defaults to @samp{#f}.
24090 @deftypevr {@code{tlp-configuration} parameter} string bay-device
24091 Name of the optical drive device to power off.
24093 Defaults to @samp{"sr0"}.
24097 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
24098 Runtime Power Management for PCI(e) bus devices. Alternatives are on
24101 Defaults to @samp{"on"}.
24105 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
24106 Same as @code{runtime-pm-ac} but on BAT mode.
24108 Defaults to @samp{"auto"}.
24112 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
24113 Runtime Power Management for all PCI(e) bus devices, except blacklisted
24116 Defaults to @samp{#t}.
24120 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
24121 Exclude specified PCI(e) device addresses from Runtime Power Management.
24123 Defaults to @samp{disabled}.
24127 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
24128 Exclude PCI(e) devices assigned to the specified drivers from Runtime
24133 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
24134 Enable USB autosuspend feature.
24136 Defaults to @samp{#t}.
24140 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
24141 Exclude specified devices from USB autosuspend.
24143 Defaults to @samp{disabled}.
24147 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
24148 Exclude WWAN devices from USB autosuspend.
24150 Defaults to @samp{#t}.
24154 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
24155 Include specified devices into USB autosuspend, even if they are already
24156 excluded by the driver or via @code{usb-blacklist-wwan?}.
24158 Defaults to @samp{disabled}.
24162 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
24163 Enable USB autosuspend before shutdown.
24165 Defaults to @samp{disabled}.
24169 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
24170 Restore radio device state (bluetooth, wifi, wwan) from previous
24171 shutdown on system startup.
24173 Defaults to @samp{#f}.
24178 @cindex CPU frequency scaling with thermald
24179 @subsubheading Thermald daemon
24181 The @code{(gnu services pm)} module provides an interface to
24182 thermald, a CPU frequency scaling service which helps prevent overheating.
24184 @defvr {Scheme Variable} thermald-service-type
24185 This is the service type for
24186 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
24187 Thermal Daemon, which is responsible for controlling the thermal state
24188 of processors and preventing overheating.
24191 @deftp {Data Type} thermald-configuration
24192 Data type representing the configuration of @code{thermald-service-type}.
24195 @item @code{ignore-cpuid-check?} (default: @code{#f})
24196 Ignore cpuid check for supported CPU models.
24198 @item @code{thermald} (default: @var{thermald})
24199 Package object of thermald.
24204 @node Audio Services
24205 @subsection Audio Services
24207 The @code{(gnu services audio)} module provides a service to start MPD
24208 (the Music Player Daemon).
24211 @subsubheading Music Player Daemon
24213 The Music Player Daemon (MPD) is a service that can play music while
24214 being controlled from the local machine or over the network by a variety
24217 The following example shows how one might run @code{mpd} as user
24218 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
24221 (service mpd-service-type
24227 @defvr {Scheme Variable} mpd-service-type
24228 The service type for @command{mpd}
24231 @deftp {Data Type} mpd-configuration
24232 Data type representing the configuration of @command{mpd}.
24235 @item @code{user} (default: @code{"mpd"})
24236 The user to run mpd as.
24238 @item @code{music-dir} (default: @code{"~/Music"})
24239 The directory to scan for music files.
24241 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
24242 The directory to store playlists.
24244 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
24245 The location of the music database.
24247 @item @code{state-file} (default: @code{"~/.mpd/state"})
24248 The location of the file that stores current MPD's state.
24250 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
24251 The location of the sticker database.
24253 @item @code{port} (default: @code{"6600"})
24254 The port to run mpd on.
24256 @item @code{address} (default: @code{"any"})
24257 The address that mpd will bind to. To use a Unix domain socket,
24258 an absolute path can be specified here.
24260 @item @code{outputs} (default: @code{"(list (mpd-output))"})
24261 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
24266 @deftp {Data Type} mpd-output
24267 Data type representing an @command{mpd} audio output.
24270 @item @code{name} (default: @code{"MPD"})
24271 The name of the audio output.
24273 @item @code{type} (default: @code{"pulse"})
24274 The type of audio output.
24276 @item @code{enabled?} (default: @code{#t})
24277 Specifies whether this audio output is enabled when MPD is started. By
24278 default, all audio outputs are enabled. This is just the default
24279 setting when there is no state file; with a state file, the previous
24282 @item @code{tags?} (default: @code{#t})
24283 If set to @code{#f}, then MPD will not send tags to this output. This
24284 is only useful for output plugins that can receive tags, for example the
24285 @code{httpd} output plugin.
24287 @item @code{always-on?} (default: @code{#f})
24288 If set to @code{#t}, then MPD attempts to keep this audio output always
24289 open. This may be useful for streaming servers, when you don’t want to
24290 disconnect all listeners even when playback is accidentally stopped.
24292 @item @code{mixer-type}
24293 This field accepts a symbol that specifies which mixer should be used
24294 for this audio output: the @code{hardware} mixer, the @code{software}
24295 mixer, the @code{null} mixer (allows setting the volume, but with no
24296 effect; this can be used as a trick to implement an external mixer
24297 External Mixer) or no mixer (@code{none}).
24299 @item @code{extra-options} (default: @code{'()"})
24300 An association list of option symbols to string values to be appended to
24301 the audio output configuration.
24306 The following example shows a configuration of @code{mpd} that provides
24307 an HTTP audio streaming output.
24310 (service mpd-service-type
24318 `((encoder . "vorbis")
24319 (port . "8080"))))))))
24323 @node Virtualization Services
24324 @subsection Virtualization services
24326 The @code{(gnu services virtualization)} module provides services for
24327 the libvirt and virtlog daemons, as well as other virtualization-related
24330 @subsubheading Libvirt daemon
24331 @code{libvirtd} is the server side daemon component of the libvirt
24332 virtualization management system. This daemon runs on host servers
24333 and performs required management tasks for virtualized guests.
24335 @deffn {Scheme Variable} libvirt-service-type
24336 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
24337 Its value must be a @code{libvirt-configuration}.
24340 (service libvirt-service-type
24341 (libvirt-configuration
24342 (unix-sock-group "libvirt")
24343 (tls-port "16555")))
24347 @c Auto-generated with (generate-libvirt-documentation)
24348 Available @code{libvirt-configuration} fields are:
24350 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
24355 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
24356 Flag listening for secure TLS connections on the public TCP/IP port.
24357 must set @code{listen} for this to have any effect.
24359 It is necessary to setup a CA and issue server certificates before using
24362 Defaults to @samp{#t}.
24366 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
24367 Listen for unencrypted TCP connections on the public TCP/IP port. must
24368 set @code{listen} for this to have any effect.
24370 Using the TCP socket requires SASL authentication by default. Only SASL
24371 mechanisms which support data encryption are allowed. This is
24372 DIGEST_MD5 and GSSAPI (Kerberos5)
24374 Defaults to @samp{#f}.
24378 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
24379 Port for accepting secure TLS connections This can be a port number, or
24382 Defaults to @samp{"16514"}.
24386 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
24387 Port for accepting insecure TCP connections This can be a port number,
24390 Defaults to @samp{"16509"}.
24394 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
24395 IP address or hostname used for client connections.
24397 Defaults to @samp{"0.0.0.0"}.
24401 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
24402 Flag toggling mDNS advertisement of the libvirt service.
24404 Alternatively can disable for all services on a host by stopping the
24407 Defaults to @samp{#f}.
24411 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
24412 Default mDNS advertisement name. This must be unique on the immediate
24415 Defaults to @samp{"Virtualization Host <hostname>"}.
24419 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
24420 UNIX domain socket group ownership. This can be used to allow a
24421 'trusted' set of users access to management capabilities without
24424 Defaults to @samp{"root"}.
24428 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
24429 UNIX socket permissions for the R/O socket. This is used for monitoring
24432 Defaults to @samp{"0777"}.
24436 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
24437 UNIX socket permissions for the R/W socket. Default allows only root.
24438 If PolicyKit is enabled on the socket, the default will change to allow
24439 everyone (eg, 0777)
24441 Defaults to @samp{"0770"}.
24445 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
24446 UNIX socket permissions for the admin socket. Default allows only owner
24447 (root), do not change it unless you are sure to whom you are exposing
24450 Defaults to @samp{"0777"}.
24454 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
24455 The directory in which sockets will be found/created.
24457 Defaults to @samp{"/var/run/libvirt"}.
24461 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
24462 Authentication scheme for UNIX read-only sockets. By default socket
24463 permissions allow anyone to connect
24465 Defaults to @samp{"polkit"}.
24469 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
24470 Authentication scheme for UNIX read-write sockets. By default socket
24471 permissions only allow root. If PolicyKit support was compiled into
24472 libvirt, the default will be to use 'polkit' auth.
24474 Defaults to @samp{"polkit"}.
24478 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
24479 Authentication scheme for TCP sockets. If you don't enable SASL, then
24480 all TCP traffic is cleartext. Don't do this outside of a dev/test
24483 Defaults to @samp{"sasl"}.
24487 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
24488 Authentication scheme for TLS sockets. TLS sockets already have
24489 encryption provided by the TLS layer, and limited authentication is done
24492 It is possible to make use of any SASL authentication mechanism as well,
24493 by using 'sasl' for this option
24495 Defaults to @samp{"none"}.
24499 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
24500 API access control scheme.
24502 By default an authenticated user is allowed access to all APIs. Access
24503 drivers can place restrictions on this.
24505 Defaults to @samp{()}.
24509 @deftypevr {@code{libvirt-configuration} parameter} string key-file
24510 Server key file path. If set to an empty string, then no private key is
24513 Defaults to @samp{""}.
24517 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
24518 Server key file path. If set to an empty string, then no certificate is
24521 Defaults to @samp{""}.
24525 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
24526 Server key file path. If set to an empty string, then no CA certificate
24529 Defaults to @samp{""}.
24533 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
24534 Certificate revocation list path. If set to an empty string, then no
24537 Defaults to @samp{""}.
24541 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
24542 Disable verification of our own server certificates.
24544 When libvirtd starts it performs some sanity checks against its own
24547 Defaults to @samp{#f}.
24551 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
24552 Disable verification of client certificates.
24554 Client certificate verification is the primary authentication mechanism.
24555 Any client which does not present a certificate signed by the CA will be
24558 Defaults to @samp{#f}.
24562 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
24563 Whitelist of allowed x509 Distinguished Name.
24565 Defaults to @samp{()}.
24569 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
24570 Whitelist of allowed SASL usernames. The format for username depends on
24571 the SASL authentication mechanism.
24573 Defaults to @samp{()}.
24577 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
24578 Override the compile time default TLS priority string. The default is
24579 usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
24580 is desired for libvirt to deviate from the global default settings.
24582 Defaults to @samp{"NORMAL"}.
24586 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
24587 Maximum number of concurrent client connections to allow over all
24590 Defaults to @samp{5000}.
24594 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
24595 Maximum length of queue of connections waiting to be accepted by the
24596 daemon. Note, that some protocols supporting retransmission may obey
24597 this so that a later reattempt at connection succeeds.
24599 Defaults to @samp{1000}.
24603 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
24604 Maximum length of queue of accepted but not yet authenticated clients.
24605 Set this to zero to turn this feature off
24607 Defaults to @samp{20}.
24611 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
24612 Number of workers to start up initially.
24614 Defaults to @samp{5}.
24618 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
24619 Maximum number of worker threads.
24621 If the number of active clients exceeds @code{min-workers}, then more
24622 threads are spawned, up to max_workers limit. Typically you'd want
24623 max_workers to equal maximum number of clients allowed.
24625 Defaults to @samp{20}.
24629 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
24630 Number of priority workers. If all workers from above pool are stuck,
24631 some calls marked as high priority (notably domainDestroy) can be
24632 executed in this pool.
24634 Defaults to @samp{5}.
24638 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
24639 Total global limit on concurrent RPC calls.
24641 Defaults to @samp{20}.
24645 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
24646 Limit on concurrent requests from a single client connection. To avoid
24647 one client monopolizing the server this should be a small fraction of
24648 the global max_requests and max_workers parameter.
24650 Defaults to @samp{5}.
24654 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
24655 Same as @code{min-workers} but for the admin interface.
24657 Defaults to @samp{1}.
24661 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
24662 Same as @code{max-workers} but for the admin interface.
24664 Defaults to @samp{5}.
24668 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
24669 Same as @code{max-clients} but for the admin interface.
24671 Defaults to @samp{5}.
24675 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
24676 Same as @code{max-queued-clients} but for the admin interface.
24678 Defaults to @samp{5}.
24682 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
24683 Same as @code{max-client-requests} but for the admin interface.
24685 Defaults to @samp{5}.
24689 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
24690 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
24692 Defaults to @samp{3}.
24696 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
24699 A filter allows to select a different logging level for a given category
24700 of logs The format for a filter is one of:
24711 where @code{name} is a string which is matched against the category
24712 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
24713 file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
24714 name in the filter can be a substring of the full category name, in
24715 order to match multiple similar categories), the optional @samp{"+"}
24716 prefix tells libvirt to log stack trace for each message matching name,
24717 and @code{x} is the minimal level where matching messages should be
24735 Multiple filters can be defined in a single filters statement, they just
24736 need to be separated by spaces.
24738 Defaults to @samp{"3:remote 4:event"}.
24742 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
24745 An output is one of the places to save logging information. The format
24746 for an output can be:
24750 output goes to stderr
24752 @item x:syslog:name
24753 use syslog for the output and use the given name as the ident
24755 @item x:file:file_path
24756 output to a file, with the given filepath
24759 output to journald logging system
24763 In all case the x prefix is the minimal level, acting as a filter
24780 Multiple outputs can be defined, they just need to be separated by
24783 Defaults to @samp{"3:stderr"}.
24787 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
24788 Allows usage of the auditing subsystem to be altered
24792 0: disable all auditing
24795 1: enable auditing, only if enabled on host
24798 2: enable auditing, and exit if disabled on host.
24802 Defaults to @samp{1}.
24806 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
24807 Send audit messages via libvirt logging infrastructure.
24809 Defaults to @samp{#f}.
24813 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
24814 Host UUID. UUID must not have all digits be the same.
24816 Defaults to @samp{""}.
24820 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
24821 Source to read host UUID.
24825 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
24828 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
24832 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
24835 Defaults to @samp{"smbios"}.
24839 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
24840 A keepalive message is sent to a client after @code{keepalive_interval}
24841 seconds of inactivity to check if the client is still responding. If
24842 set to -1, libvirtd will never send keepalive requests; however clients
24843 can still send them and the daemon will send responses.
24845 Defaults to @samp{5}.
24849 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
24850 Maximum number of keepalive messages that are allowed to be sent to the
24851 client without getting any response before the connection is considered
24854 In other words, the connection is automatically closed approximately
24855 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
24856 the last message received from the client. When @code{keepalive-count}
24857 is set to 0, connections will be automatically closed after
24858 @code{keepalive-interval} seconds of inactivity without sending any
24859 keepalive messages.
24861 Defaults to @samp{5}.
24865 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
24866 Same as above but for admin interface.
24868 Defaults to @samp{5}.
24872 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
24873 Same as above but for admin interface.
24875 Defaults to @samp{5}.
24879 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
24880 Timeout for Open vSwitch calls.
24882 The @code{ovs-vsctl} utility is used for the configuration and its
24883 timeout option is set by default to 5 seconds to avoid potential
24884 infinite waits blocking libvirt.
24886 Defaults to @samp{5}.
24890 @c %end of autogenerated docs
24892 @subsubheading Virtlog daemon
24893 The virtlogd service is a server side daemon component of libvirt that is
24894 used to manage logs from virtual machine consoles.
24896 This daemon is not used directly by libvirt client applications, rather it
24897 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
24898 standalone daemon, the main @code{libvirtd} daemon can be restarted without
24899 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
24900 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
24902 @deffn {Scheme Variable} virtlog-service-type
24903 This is the type of the virtlog daemon.
24904 Its value must be a @code{virtlog-configuration}.
24907 (service virtlog-service-type
24908 (virtlog-configuration
24909 (max-clients 1000)))
24913 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
24914 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
24916 Defaults to @samp{3}.
24920 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
24923 A filter allows to select a different logging level for a given category
24924 of logs The format for a filter is one of:
24935 where @code{name} is a string which is matched against the category
24936 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
24937 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
24938 be a substring of the full category name, in order to match multiple
24939 similar categories), the optional "+" prefix tells libvirt to log stack
24940 trace for each message matching name, and @code{x} is the minimal level
24941 where matching messages should be logged:
24958 Multiple filters can be defined in a single filters statement, they just
24959 need to be separated by spaces.
24961 Defaults to @samp{"3:remote 4:event"}.
24965 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
24968 An output is one of the places to save logging information The format
24969 for an output can be:
24973 output goes to stderr
24975 @item x:syslog:name
24976 use syslog for the output and use the given name as the ident
24978 @item x:file:file_path
24979 output to a file, with the given filepath
24982 output to journald logging system
24986 In all case the x prefix is the minimal level, acting as a filter
25003 Multiple outputs can be defined, they just need to be separated by
25006 Defaults to @samp{"3:stderr"}.
25010 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
25011 Maximum number of concurrent client connections to allow over all
25014 Defaults to @samp{1024}.
25018 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
25019 Maximum file size before rolling over.
25021 Defaults to @samp{2MB}
25025 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
25026 Maximum number of backup files to keep.
25028 Defaults to @samp{3}
25031 @node Transparent Emulation with QEMU
25032 @subsubheading Transparent Emulation with QEMU
25035 @cindex @code{binfmt_misc}
25036 @code{qemu-binfmt-service-type} provides support for transparent
25037 emulation of program binaries built for different architectures---e.g.,
25038 it allows you to transparently execute an ARMv7 program on an x86_64
25039 machine. It achieves this by combining the @uref{https://www.qemu.org,
25040 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
25042 @defvr {Scheme Variable} qemu-binfmt-service-type
25043 This is the type of the QEMU/binfmt service for transparent emulation.
25044 Its value must be a @code{qemu-binfmt-configuration} object, which
25045 specifies the QEMU package to use as well as the architecture we want to
25049 (service qemu-binfmt-service-type
25050 (qemu-binfmt-configuration
25051 (platforms (lookup-qemu-platforms "arm" "aarch64"))))
25054 In this example, we enable transparent emulation for the ARM and aarch64
25055 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
25056 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
25057 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
25060 @deftp {Data Type} qemu-binfmt-configuration
25061 This is the configuration for the @code{qemu-binfmt} service.
25064 @item @code{platforms} (default: @code{'()})
25065 The list of emulated QEMU platforms. Each item must be a @dfn{platform
25066 object} as returned by @code{lookup-qemu-platforms} (see below).
25068 @item @code{guix-support?} (default: @code{#f})
25069 When it is true, QEMU and all its dependencies are added to the build
25070 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
25071 @option{--chroot-directory} option}). This allows the @code{binfmt_misc}
25072 handlers to be used within the build environment, which in turn means
25073 that you can transparently build programs for another architecture.
25075 For example, let's suppose you're on an x86_64 machine and you have this
25079 (service qemu-binfmt-service-type
25080 (qemu-binfmt-configuration
25081 (platforms (lookup-qemu-platforms "arm"))
25082 (guix-support? #t)))
25088 guix build -s armhf-linux inkscape
25092 and it will build Inkscape for ARMv7 @emph{as if it were a native
25093 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
25094 if you'd like to test a package build for an architecture you don't have
25097 @item @code{qemu} (default: @code{qemu})
25098 The QEMU package to use.
25102 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
25103 Return the list of QEMU platform objects corresponding to
25104 @var{platforms}@dots{}. @var{platforms} must be a list of strings
25105 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
25106 @code{"mips64el"}, and so on.
25109 @deffn {Scheme Procedure} qemu-platform? @var{obj}
25110 Return true if @var{obj} is a platform object.
25113 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
25114 Return the name of @var{platform}---a string such as @code{"arm"}.
25118 @subsubheading The Hurd in a Virtual Machine
25120 @cindex @code{hurd}
25123 Service @code{hurd-vm} provides support for running GNU/Hurd in a
25124 virtual machine (VM), a so-called ``Childhurd''. The virtual machine is
25125 a Shepherd service that can be referred to by the names @code{hurd-vm}
25126 and @code{childhurd} and be controlled with commands such as:
25130 herd stop childhurd
25133 The given GNU/Hurd operating system configuration is cross-compiled.
25135 @defvr {Scheme Variable} hurd-vm-service-type
25136 This is the type of the Hurd in a Virtual Machine service. Its value
25137 must be a @code{hurd-vm-configuration} object, which specifies the
25138 operating system (@pxref{operating-system Reference}) and the disk size
25139 for the Hurd Virtual Machine, the QEMU package to use as well as the
25140 options for running it.
25145 (service hurd-vm-service-type
25146 (hurd-vm-configuration
25147 (disk-size (* 5000 (expt 2 20))) ;5G
25148 (memory-size 1024))) ;1024MiB
25151 would create a disk image big enough to build GNU@tie{}Hello, with some
25155 @deftp {Data Type} hurd-vm-configuration
25156 The data type representing the configuration for
25157 @code{hurd-vm-service-type}.
25160 @item @code{os} (default: @var{%hurd-vm-operating-system})
25161 The operating system to instantiate. This default is bare-bones with a
25162 permissive OpenSSH secure shell daemon listening on port 2222
25163 (@pxref{Networking Services, @code{openssh-service-type}}).
25165 @item @code{qemu} (default: @code{qemu-minimal})
25166 The QEMU package to use.
25168 @item @code{image} (default: @var{hurd-vm-disk-image})
25169 The procedure used to build the disk-image built from this
25172 @item @code{disk-size} (default: @code{'guess})
25173 The size of the disk image.
25175 @item @code{memory-size} (default: @code{512})
25176 The memory size of the Virtual Machine in mebibytes.
25178 @item @code{options} (default: @code{'("--snapshot")})
25179 The extra options for running QEMU.
25181 @item @code{id} (default: @code{#f})
25182 If set, a non-zero positive integer used to parameterize Childhurd
25183 instances. It is appended to the service's name,
25184 e.g. @code{childhurd1}.
25186 @item @code{net-options} (default: @var{hurd-vm-net-options})
25187 The procedure used to produce the list of QEMU networking options.
25189 By default, it produces
25192 '("--device" "rtl8139,netdev=net0"
25193 "--netdev" "user,id=net0\
25194 ,hostfwd=tcp:127.0.0.1:<ssh-port>-:2222\
25195 ,hostfwd=tcp:127.0.0.1:<vnc-port>-:5900")
25197 with forwarded ports
25199 <ssh-port>: @code{(+ 10022 (* 1000 @var{ID}))}
25200 <vnc-port>: @code{(+ 15900 (* 1000 @var{ID}))}
25206 Note that by default the VM image is volatile, i.e., once stopped the
25207 contents are lost. If you want a stateful image instead, override the
25208 configuration's @code{image} and @code{options} without
25209 the @code{--snapshot} flag using something along these lines:
25212 (service hurd-vm-service-type
25213 (hurd-vm-configuration
25214 (image (const "/out/of/store/writable/hurd.img"))
25215 (options '("--hda"))))
25218 @subsubheading Ganeti
25223 This service is considered experimental. Configuration options may be changed
25224 in a backwards-incompatible manner, and not all features have been thorougly
25225 tested. Users of this service are encouraged to share their experience at
25226 @email{guix-devel@@gnu.org}.
25229 Ganeti is a virtual machine management system. It is designed to keep virtual
25230 machines running on a cluster of servers even in the event of hardware failures,
25231 and to make maintenance and recovery tasks easy. It consists of multiple
25232 services which are described later in this section. In addition to the Ganeti
25233 service, you will need the OpenSSH service (@pxref{Networking Services,
25234 @code{openssh-service-type}}), and update the @file{/etc/hosts} file
25235 (@pxref{operating-system Reference, @code{hosts-file}}) with the cluster name
25236 and address (or use a DNS server).
25238 All nodes participating in a Ganeti cluster should have the same Ganeti and
25239 @file{/etc/hosts} configuration. Here is an example configuration for a Ganeti
25240 cluster node that supports multiple storage backends, and installs the
25241 @code{debootstrap} and @code{guix} @dfn{OS providers}:
25244 (use-package-modules virtualization)
25245 (use-service-modules base ganeti networking ssh)
25248 (host-name "node1")
25249 (hosts-file (plain-file "hosts" (format #f "
25250 127.0.0.1 localhost
25253 192.168.1.200 ganeti.example.com
25254 192.168.1.201 node1.example.com node1
25255 192.168.1.202 node2.example.com node2
25258 ;; Install QEMU so we can use KVM-based instances, and LVM, DRBD and Ceph
25259 ;; in order to use the "plain", "drbd" and "rbd" storage backends.
25260 (packages (append (map specification->package
25261 '("qemu" "lvm2" "drbd-utils" "ceph"
25262 ;; Add the debootstrap and guix OS providers.
25263 "ganeti-instance-guix" "ganeti-instance-debootstrap"))
25266 (append (list (static-networking-service "eth0" "192.168.1.201"
25267 #:netmask "255.255.255.0"
25268 #:gateway "192.168.1.254"
25269 #:name-servers '("192.168.1.252"
25272 ;; Ganeti uses SSH to communicate between nodes.
25273 (service openssh-service-type
25274 (openssh-configuration
25275 (permit-root-login 'without-password)))
25277 (service ganeti-service-type
25278 (ganeti-configuration
25279 ;; This list specifies allowed file system paths
25280 ;; for storing virtual machine images.
25281 (file-storage-paths '("/srv/ganeti/file-storage"))
25282 ;; This variable configures a single "variant" for
25283 ;; both Debootstrap and Guix that works with KVM.
25284 (os %default-ganeti-os))))
25288 Users are advised to read the
25289 @url{http://docs.ganeti.org/ganeti/master/html/admin.html,Ganeti
25290 administrators guide} to learn about the various cluster options and
25291 day-to-day operations. There is also a
25292 @url{https://guix.gnu.org/blog/2020/running-a-ganeti-cluster-on-guix/,blog post}
25293 describing how to configure and initialize a small cluster.
25295 @defvr {Scheme Variable} ganeti-service-type
25296 This is a service type that includes all the various services that Ganeti
25299 Its value is a @code{ganeti-configuration} object that defines the package
25300 to use for CLI operations, as well as configuration for the various daemons.
25301 Allowed file storage paths and available guest operating systems are also
25302 configured through this data type.
25305 @deftp {Data Type} ganeti-configuration
25306 The @code{ganeti} service takes the following configuration options:
25309 @item @code{ganeti} (default: @code{ganeti})
25310 The @code{ganeti} package to use. It will be installed to the system profile
25311 and make @command{gnt-cluster}, @command{gnt-instance}, etc available. Note
25312 that the value specified here does not affect the other services as each refer
25313 to a specific @code{ganeti} package (see below).
25315 @item @code{noded-configuration} (default: @code{(ganeti-noded-configuration)})
25316 @itemx @code{confd-configuration} (default: @code{(ganeti-confd-configuration)})
25317 @itemx @code{wconfd-configuration} (default: @code{(ganeti-wconfd-configuration)})
25318 @itemx @code{luxid-configuration} (default: @code{(ganeti-luxid-configuration)})
25319 @itemx @code{rapi-configuration} (default: @code{(ganeti-rapi-configuration)})
25320 @itemx @code{kvmd-configuration} (default: @code{(ganeti-kvmd-configuration)})
25321 @itemx @code{mond-configuration} (default: @code{(ganeti-mond-configuration)})
25322 @itemx @code{metad-configuration} (default: @code{(ganeti-metad-configuration)})
25323 @itemx @code{watcher-configuration} (default: @code{(ganeti-watcher-configuration)})
25324 @itemx @code{cleaner-configuration} (default: @code{(ganeti-cleaner-configuration)})
25326 These options control the various daemons and cron jobs that are distributed
25327 with Ganeti. The possible values for these are described in detail below.
25328 To override a setting, you must use the configuration type for that service:
25331 (service ganeti-service-type
25332 (ganeti-configuration
25333 (rapi-configuration
25334 (ganeti-rapi-configuration
25335 (interface "eth1"))))
25336 (watcher-configuration
25337 (ganeti-watcher-configuration
25338 (rapi-ip "10.0.0.1"))))
25341 @item @code{file-storage-paths} (default: @code{'()})
25342 List of allowed directories for file storage backend.
25344 @item @code{os} (default: @code{%default-ganeti-os})
25345 List of @code{<ganeti-os>} records.
25348 In essence @code{ganeti-service-type} is shorthand for declaring each service
25352 (service ganeti-noded-service-type)
25353 (service ganeti-confd-service-type)
25354 (service ganeti-wconfd-service-type)
25355 (service ganeti-luxid-service-type)
25356 (service ganeti-kvmd-service-type)
25357 (service ganeti-mond-service-type)
25358 (service ganeti-metad-service-type)
25359 (service ganeti-watcher-service-type)
25360 (service ganeti-cleaner-service-type)
25363 Plus a service extension for @code{etc-service-type} that configures the file
25364 storage backend and OS variants.
25368 @deftp {Data Type} ganeti-os
25369 This data type is suitable for passing to the @code{os} parameter of
25370 @code{ganeti-configuration}. It takes the following parameters:
25374 The name for this OS provider. It is only used to specify where the
25375 configuration ends up. Setting it to ``debootstrap'' will create
25376 @file{/etc/ganeti/instance-debootstrap}.
25378 @item @code{extension}
25379 The file extension for variants of this OS type. For example
25380 @file{.conf} or @file{.scm}.
25382 @item @code{variants} (default: @code{'()})
25383 List of @code{ganeti-os-variant} objects for this OS.
25388 @deftp {Data Type} ganeti-os-variant
25389 This is the data type for a Ganeti OS variant. It takes the following
25394 The name of this variant.
25396 @item @code{configuration}
25397 A configuration file for this variant.
25401 @defvr {Scheme Variable} %default-debootstrap-hooks
25402 This variable contains hooks to configure networking and the GRUB bootloader.
25405 @defvr {Scheme Variable} %default-debootstrap-extra-pkgs
25406 This variable contains a list of packages suitable for a fully-virtualized guest.
25409 @deftp {Data Type} debootstrap-configuration
25411 This data type creates configuration files suitable for the debootstrap OS provider.
25414 @item @code{hooks} (default: @code{%default-debootstrap-hooks})
25415 When not @code{#f}, this must be a G-expression that specifies a directory with
25416 scripts that will run when the OS is installed. It can also be a list of
25417 @code{(name . file-like)} pairs. For example:
25420 `((99-hello-world . ,(plain-file "#!/bin/sh\necho Hello, World")))
25423 That will create a directory with one executable named @code{99-hello-world}
25424 and run it every time this variant is installed. If set to @code{#f}, hooks
25425 in @file{/etc/ganeti/instance-debootstrap/hooks} will be used, if any.
25426 @item @code{proxy} (default: @code{#f})
25427 Optional HTTP proxy to use.
25428 @item @code{mirror} (default: @code{#f})
25429 The Debian mirror. Typically something like @code{http://ftp.no.debian.org/debian}.
25430 The default varies depending on the distribution.
25431 @item @code{arch} (default: @code{#f})
25432 The dpkg architecture. Set to @code{armhf} to debootstrap an ARMv7 instance
25433 on an AArch64 host. Default is to use the current system architecture.
25434 @item @code{suite} (default: @code{"stable"})
25435 When set, this must be a Debian distribution ``suite'' such as @code{buster}
25436 or @code{focal}. If set to @code{#f}, the default for the OS provider is used.
25437 @item @code{extra-pkgs} (default: @code{%default-debootstrap-extra-pkgs})
25438 List of extra packages that will get installed by dpkg in addition
25439 to the minimal system.
25440 @item @code{components} (default: @code{#f})
25441 When set, must be a list of Debian repository ``components''. For example
25442 @code{'("main" "contrib")}.
25443 @item @code{generate-cache?} (default: @code{#t})
25444 Whether to automatically cache the generated debootstrap archive.
25445 @item @code{clean-cache} (default: @code{14})
25446 Discard the cache after this amount of days. Use @code{#f} to never
25448 @item @code{partition-style} (default: @code{'msdos})
25449 The type of partition to create. When set, it must be one of
25450 @code{'msdos}, @code{'none} or a string.
25451 @item @code{partition-alignment} (default: @code{2048})
25452 Alignment of the partition in sectors.
25456 @deffn {Scheme Procedure} debootstrap-variant @var{name} @var{configuration}
25457 This is a helper procedure that creates a @code{ganeti-os-variant} record. It
25458 takes two parameters: a name and a @code{debootstrap-configuration} object.
25461 @deffn {Scheme Procedure} debootstrap-os @var{variants}@dots{}
25462 This is a helper procedure that creates a @code{ganeti-os} record. It takes
25463 a list of variants created with @code{debootstrap-variant}.
25466 @deffn {Scheme Procedure} guix-variant @var{name} @var{configuration}
25467 This is a helper procedure that creates a @code{ganeti-os-variant} record for
25468 use with the Guix OS provider. It takes a name and a G-expression that returns
25469 a ``file-like'' (@pxref{G-Expressions, file-like objects}) object containing a
25470 Guix System configuration.
25473 @deffn {Scheme Procedure} guix-os @var{variants}@dots{}
25474 This is a helper procedure that creates a @code{ganeti-os} record. It
25475 takes a list of variants produced by @code{guix-variant}.
25478 @defvr {Scheme Variable} %default-debootstrap-variants
25479 This is a convenience variable to make the debootstrap provider work
25480 ``out of the box'' without users having to declare variants manually. It
25481 contains a single debootstrap variant with the default configuration:
25484 (list (debootstrap-variant
25486 (debootstrap-configuration)))
25490 @defvr {Scheme Variable} %default-guix-variants
25491 This is a convenience variable to make the Guix OS provider work without
25492 additional configuration. It creates a virtual machine that has an SSH
25493 server, a serial console, and authorizes the Ganeti hosts SSH keys.
25496 (list (guix-variant
25498 (file-append ganeti-instance-guix
25499 "/share/doc/ganeti-instance-guix/examples/dynamic.scm")))
25503 Users can implement support for OS providers unbeknownst to Guix by extending
25504 the @code{ganeti-os} and @code{ganeti-os-variant} records appropriately.
25510 (extension ".conf")
25512 (list (ganeti-os-variant
25514 (configuration (plain-file "bar" "this is fine"))))))
25517 That creates @file{/etc/ganeti/instance-custom/variants/foo.conf} which points
25518 to a file in the store with contents @code{this is fine}. It also creates
25519 @file{/etc/ganeti/instance-custom/variants/variants.list} with contents @code{foo}.
25521 Obviously this may not work for all OS providers out there. If you find the
25522 interface limiting, please reach out to @email{guix-devel@@gnu.org}.
25524 The rest of this section documents the various services that are included by
25525 @code{ganeti-service-type}.
25527 @defvr {Scheme Variable} ganeti-noded-service-type
25528 @command{ganeti-noded} is the daemon responsible for node-specific functions
25529 within the Ganeti system. The value of this service must be a
25530 @code{ganeti-noded-configuration} object.
25533 @deftp {Data Type} ganeti-noded-configuration
25534 This is the configuration for the @code{ganeti-noded} service.
25537 @item @code{ganeti} (default: @code{ganeti})
25538 The @code{ganeti} package to use for this service.
25540 @item @code{port} (default: @code{1811})
25541 The TCP port on which the node daemon listens for network requests.
25543 @item @code{address} (default: @code{"0.0.0.0"})
25544 The network address that the daemon will bind to. The default address means
25545 bind to all available addresses.
25547 @item @code{interface} (default: @code{#f})
25548 When this is set, it must be a specific network interface (e.g.@: @code{eth0})
25549 that the daemon will bind to.
25551 @item @code{max-clients} (default: @code{20})
25552 This sets a limit on the maximum number of simultaneous client connections
25553 that the daemon will handle. Connections above this count are accepted, but
25554 no responses will be sent until enough connections have closed.
25556 @item @code{ssl?} (default: @code{#t})
25557 Whether to use SSL/TLS to encrypt network communications. The certificate
25558 is automatically provisioned by the cluster and can be rotated with
25559 @command{gnt-cluster renew-crypto}.
25561 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
25562 This can be used to provide a specific encryption key for TLS communications.
25564 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
25565 This can be used to provide a specific certificate for TLS communications.
25567 @item @code{debug?} (default: @code{#f})
25568 When true, the daemon performs additional logging for debugging purposes.
25569 Note that this will leak encryption details to the log files, use with caution.
25574 @defvr {Scheme Variable} ganeti-confd-service-type
25575 @command{ganeti-confd} answers queries related to the configuration of a
25576 Ganeti cluster. The purpose of this daemon is to have a highly available
25577 and fast way to query cluster configuration values. It is automatically
25578 active on all @dfn{master candidates}. The value of this service must be a
25579 @code{ganeti-confd-configuration} object.
25583 @deftp {Data Type} ganeti-confd-configuration
25584 This is the configuration for the @code{ganeti-confd} service.
25587 @item @code{ganeti} (default: @code{ganeti})
25588 The @code{ganeti} package to use for this service.
25590 @item @code{port} (default: @code{1814})
25591 The UDP port on which to listen for network requests.
25593 @item @code{address} (default: @code{"0.0.0.0"})
25594 Network address that the daemon will bind to.
25596 @item @code{debug?} (default: @code{#f})
25597 When true, the daemon performs additional logging for debugging purposes.
25602 @defvr {Scheme Variable} ganeti-wconfd-service-type
25603 @command{ganeti-wconfd} is the daemon that has authoritative knowledge
25604 about the cluster configuration and is the only entity that can accept
25605 changes to it. All jobs that need to modify the configuration will do so
25606 by sending appropriate requests to this daemon. It only runs on the
25607 @dfn{master node} and will automatically disable itself on other nodes.
25609 The value of this service must be a
25610 @code{ganeti-wconfd-configuration} object.
25613 @deftp {Data Type} ganeti-wconfd-configuration
25614 This is the configuration for the @code{ganeti-wconfd} service.
25617 @item @code{ganeti} (default: @code{ganeti})
25618 The @code{ganeti} package to use for this service.
25620 @item @code{no-voting?} (default: @code{#f})
25621 The daemon will refuse to start if the majority of cluster nodes does not
25622 agree that it is running on the master node. Set to @code{#t} to start
25623 even if a quorum can not be reached (dangerous, use with caution).
25625 @item @code{debug?} (default: @code{#f})
25626 When true, the daemon performs additional logging for debugging purposes.
25631 @defvr {Scheme Variable} ganeti-luxid-service-type
25632 @command{ganeti-luxid} is a daemon used to answer queries related to the
25633 configuration and the current live state of a Ganeti cluster. Additionally,
25634 it is the authoritative daemon for the Ganeti job queue. Jobs can be
25635 submitted via this daemon and it schedules and starts them.
25637 It takes a @code{ganeti-luxid-configuration} object.
25640 @deftp {Data Type} ganeti-luxid-configuration
25641 This is the configuration for the @code{ganeti-wconfd} service.
25644 @item @code{ganeti} (default: @code{ganeti})
25645 The @code{ganeti} package to use for this service.
25647 @item @code{no-voting?} (default: @code{#f})
25648 The daemon will refuse to start if it cannot verify that the majority of
25649 cluster nodes believes that it is running on the master node. Set to
25650 @code{#t} to ignore such checks and start anyway (this can be dangerous).
25652 @item @code{debug?} (default: @code{#f})
25653 When true, the daemon performs additional logging for debugging purposes.
25658 @defvr {Scheme Variable} ganeti-rapi-service-type
25659 @command{ganeti-rapi} provides a remote API for Ganeti clusters. It runs on
25660 the master node and can be used to perform cluster actions programmatically
25661 via a JSON-based RPC protocol.
25663 Most query operations are allowed without authentication (unless
25664 @var{require-authentication?} is set), whereas write operations require
25665 explicit authorization via the @file{/var/lib/ganeti/rapi/users} file. See
25666 the @url{http://docs.ganeti.org/ganeti/master/html/rapi.html, Ganeti Remote
25667 API documentation} for more information.
25669 The value of this service must be a @code{ganeti-rapi-configuration} object.
25672 @deftp {Data Type} ganeti-rapi-configuration
25673 This is the configuration for the @code{ganeti-rapi} service.
25676 @item @code{ganeti} (default: @code{ganeti})
25677 The @code{ganeti} package to use for this service.
25679 @item @code{require-authentication?} (default: @code{#f})
25680 Whether to require authentication even for read-only operations.
25682 @item @code{port} (default: @code{5080})
25683 The TCP port on which to listen to API requests.
25685 @item @code{address} (default: @code{"0.0.0.0"})
25686 The network address that the service will bind to. By default it listens
25687 on all configured addresses.
25689 @item @code{interface} (default: @code{#f})
25690 When set, it must specify a specific network interface such as @code{eth0}
25691 that the daemon will bind to.
25693 @item @code{max-clients} (default: @code{20})
25694 The maximum number of simultaneous client requests to handle. Further
25695 connections are allowed, but no responses are sent until enough connections
25698 @item @code{ssl?} (default: @code{#t})
25699 Whether to use SSL/TLS encryption on the RAPI port.
25701 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
25702 This can be used to provide a specific encryption key for TLS communications.
25704 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
25705 This can be used to provide a specific certificate for TLS communications.
25707 @item @code{debug?} (default: @code{#f})
25708 When true, the daemon performs additional logging for debugging purposes.
25709 Note that this will leak encryption details to the log files, use with caution.
25714 @defvr {Scheme Variable} ganeti-kvmd-service-type
25715 @command{ganeti-kvmd} is responsible for determining whether a given KVM
25716 instance was shut down by an administrator or a user. Normally Ganeti will
25717 restart an instance that was not stopped through Ganeti itself. If the
25718 cluster option @code{user_shutdown} is true, this daemon monitors the
25719 @code{QMP} socket provided by QEMU and listens for shutdown events, and
25720 marks the instance as @dfn{USER_down} instead of @dfn{ERROR_down} when
25721 it shuts down gracefully by itself.
25723 It takes a @code{ganeti-kvmd-configuration} object.
25726 @deftp {Data Type} ganeti-kvmd-configuration
25729 @item @code{ganeti} (default: @code{ganeti})
25730 The @code{ganeti} package to use for this service.
25732 @item @code{debug?} (default: @code{#f})
25733 When true, the daemon performs additional logging for debugging purposes.
25738 @defvr {Scheme Variable} ganeti-mond-service-type
25739 @command{ganeti-mond} is an optional daemon that provides Ganeti monitoring
25740 functionality. It is responsible for running data collectors and publish the
25741 collected information through a HTTP interface.
25743 It takes a @code{ganeti-mond-configuration} object.
25746 @deftp {Data Type} ganeti-mond-configuration
25749 @item @code{ganeti} (default: @code{ganeti})
25750 The @code{ganeti} package to use for this service.
25752 @item @code{port} (default: @code{1815})
25753 The port on which the daemon will listen.
25755 @item @code{address} (default: @code{"0.0.0.0"})
25756 The network address that the daemon will bind to. By default it binds to all
25757 available interfaces.
25759 @item @code{debug?} (default: @code{#f})
25760 When true, the daemon performs additional logging for debugging purposes.
25765 @defvr {Scheme Variable} ganeti-metad-service-type
25766 @command{ganeti-metad} is an optional daemon that can be used to provide
25767 information about the cluster to instances or OS install scripts.
25769 It takes a @code{ganeti-metad-configuration} object.
25772 @deftp {Data Type} ganeti-metad-configuration
25775 @item @code{ganeti} (default: @code{ganeti})
25776 The @code{ganeti} package to use for this service.
25778 @item @code{port} (default: @code{80})
25779 The port on which the daemon will listen.
25781 @item @code{address} (default: @code{#f})
25782 If set, the daemon will bind to this address only. If left unset, the behavior
25783 depends on the cluster configuration.
25785 @item @code{debug?} (default: @code{#f})
25786 When true, the daemon performs additional logging for debugging purposes.
25791 @defvr {Scheme Variable} ganeti-watcher-service-type
25792 @command{ganeti-watcher} is a script designed to run periodically and ensure
25793 the health of a cluster. It will automatically restart instances that have
25794 stopped without Ganetis consent, and repairs DRBD links in case a node has
25795 rebooted. It also archives old cluster jobs and restarts Ganeti daemons
25796 that are not running. If the cluster parameter @code{ensure_node_health}
25797 is set, the watcher will also shutdown instances and DRBD devices if the
25798 node it is running on is declared offline by known master candidates.
25800 It can be paused on all nodes with @command{gnt-cluster watcher pause}.
25802 The service takes a @code{ganeti-watcher-configuration} object.
25805 @deftp {Data Type} ganeti-watcher-configuration
25808 @item @code{ganeti} (default: @code{ganeti})
25809 The @code{ganeti} package to use for this service.
25811 @item @code{schedule} (default: @code{'(next-second-from (next-minute (range 0 60 5)))})
25812 How often to run the script. The default is every five minutes.
25814 @item @code{rapi-ip} (default: @code{#f})
25815 This option needs to be specified only if the RAPI daemon is configured to use
25816 a particular interface or address. By default the cluster address is used.
25818 @item @code{job-age} (default: @code{(* 6 3600)})
25819 Archive cluster jobs older than this age, specified in seconds. The default
25820 is 6 hours. This keeps @command{gnt-job list} manageable.
25822 @item @code{verify-disks?} (default: @code{#t})
25823 If this is @code{#f}, the watcher will not try to repair broken DRBD links
25824 automatically. Administrators will need to use @command{gnt-cluster verify-disks}
25827 @item @code{debug?} (default: @code{#f})
25828 When @code{#t}, the script performs additional logging for debugging purposes.
25833 @defvr {Scheme Variable} ganeti-cleaner-service-type
25834 @command{ganeti-cleaner} is a script designed to run periodically and remove
25835 old files from the cluster. This service type controls two @dfn{cron jobs}:
25836 one intended for the master node that permanently purges old cluster jobs,
25837 and one intended for every node that removes expired X509 certificates, keys,
25838 and outdated @command{ganeti-watcher} information. Like all Ganeti services,
25839 it is safe to include even on non-master nodes as it will disable itself as
25842 It takes a @code{ganeti-cleaner-configuration} object.
25845 @deftp {Data Type} ganeti-cleaner-configuration
25848 @item @code{ganeti} (default: @code{ganeti})
25849 The @code{ganeti} package to use for the @command{gnt-cleaner} command.
25851 @item @code{master-schedule} (default: @code{"45 1 * * *"})
25852 How often to run the master cleaning job. The default is once per day, at
25855 @item @code{node-schedule} (default: @code{"45 2 * * *"})
25856 How often to run the node cleaning job. The default is once per day, at
25862 @node Version Control Services
25863 @subsection Version Control Services
25865 The @code{(gnu services version-control)} module provides a service to
25866 allow remote access to local Git repositories. There are three options:
25867 the @code{git-daemon-service}, which provides access to repositories via
25868 the @code{git://} unsecured TCP-based protocol, extending the
25869 @code{nginx} web server to proxy some requests to
25870 @code{git-http-backend}, or providing a web interface with
25871 @code{cgit-service-type}.
25873 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
25875 Return a service that runs @command{git daemon}, a simple TCP server to
25876 expose repositories over the Git protocol for anonymous access.
25878 The optional @var{config} argument should be a
25879 @code{<git-daemon-configuration>} object, by default it allows read-only
25880 access to exported@footnote{By creating the magic file
25881 @file{git-daemon-export-ok} in the repository directory.} repositories under
25886 @deftp {Data Type} git-daemon-configuration
25887 Data type representing the configuration for @code{git-daemon-service}.
25890 @item @code{package} (default: @code{git})
25891 Package object of the Git distributed version control system.
25893 @item @code{export-all?} (default: @code{#f})
25894 Whether to allow access for all Git repositories, even if they do not
25895 have the @file{git-daemon-export-ok} file.
25897 @item @code{base-path} (default: @file{/srv/git})
25898 Whether to remap all the path requests as relative to the given path.
25899 If you run @command{git daemon} with @code{(base-path "/srv/git")} on
25900 @samp{example.com}, then if you later try to pull
25901 @indicateurl{git://example.com/hello.git}, git daemon will interpret the
25902 path as @file{/srv/git/hello.git}.
25904 @item @code{user-path} (default: @code{#f})
25905 Whether to allow @code{~user} notation to be used in requests. When
25906 specified with empty string, requests to
25907 @indicateurl{git://host/~alice/foo} is taken as a request to access
25908 @code{foo} repository in the home directory of user @code{alice}. If
25909 @code{(user-path "@var{path}")} is specified, the same request is taken
25910 as a request to access @file{@var{path}/foo} repository in the home
25911 directory of user @code{alice}.
25913 @item @code{listen} (default: @code{'()})
25914 Whether to listen on specific IP addresses or hostnames, defaults to
25917 @item @code{port} (default: @code{#f})
25918 Whether to listen on an alternative port, which defaults to 9418.
25920 @item @code{whitelist} (default: @code{'()})
25921 If not empty, only allow access to this list of directories.
25923 @item @code{extra-options} (default: @code{'()})
25924 Extra options will be passed to @command{git daemon}, please run
25925 @command{man git-daemon} for more information.
25930 The @code{git://} protocol lacks authentication. When you pull from a
25931 repository fetched via @code{git://}, you don't know whether the data you
25932 receive was modified or is even coming from the specified host, and your
25933 connection is subject to eavesdropping. It's better to use an authenticated
25934 and encrypted transport, such as @code{https}. Although Git allows you
25935 to serve repositories using unsophisticated file-based web servers,
25936 there is a faster protocol implemented by the @code{git-http-backend}
25937 program. This program is the back-end of a proper Git web service. It
25938 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
25939 on running the necessary @code{fcgiwrap} daemon.
25941 Guix has a separate configuration data type for serving Git repositories
25944 @deftp {Data Type} git-http-configuration
25945 Data type representing the configuration for a future
25946 @code{git-http-service-type}; can currently be used to configure Nginx
25947 trough @code{git-http-nginx-location-configuration}.
25950 @item @code{package} (default: @var{git})
25951 Package object of the Git distributed version control system.
25953 @item @code{git-root} (default: @file{/srv/git})
25954 Directory containing the Git repositories to expose to the world.
25956 @item @code{export-all?} (default: @code{#f})
25957 Whether to expose access for all Git repositories in @var{git-root},
25958 even if they do not have the @file{git-daemon-export-ok} file.
25960 @item @code{uri-path} (default: @samp{/git/})
25961 Path prefix for Git access. With the default @samp{/git/} prefix, this
25962 will map @indicateurl{http://@var{server}/git/@var{repo}.git} to
25963 @file{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
25964 with this prefix are not passed on to this Git instance.
25966 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
25967 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
25972 There is no @code{git-http-service-type}, currently; instead you can
25973 create an @code{nginx-location-configuration} from a
25974 @code{git-http-configuration} and then add that location to a web
25977 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
25978 [config=(git-http-configuration)]
25979 Compute an @code{nginx-location-configuration} that corresponds to the
25980 given Git http configuration. An example nginx service definition to
25981 serve the default @file{/srv/git} over HTTPS might be:
25984 (service nginx-service-type
25985 (nginx-configuration
25988 (nginx-server-configuration
25989 (listen '("443 ssl"))
25990 (server-name "git.my-host.org")
25992 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
25993 (ssl-certificate-key
25994 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
25997 (git-http-nginx-location-configuration
25998 (git-http-configuration (uri-path "/"))))))))))
26001 This example assumes that you are using Let's Encrypt to get your TLS
26002 certificate. @xref{Certificate Services}. The default @code{certbot}
26003 service will redirect all HTTP traffic on @code{git.my-host.org} to
26004 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
26005 system services. @xref{Web Services}.
26008 @subsubheading Cgit Service
26010 @cindex Cgit service
26011 @cindex Git, web interface
26012 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
26013 repositories written in C.
26015 The following example will configure the service with default values.
26016 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
26019 (service cgit-service-type)
26022 The @code{file-object} type designates either a file-like object
26023 (@pxref{G-Expressions, file-like objects}) or a string.
26025 @c %start of fragment
26027 Available @code{cgit-configuration} fields are:
26029 @deftypevr {@code{cgit-configuration} parameter} package package
26034 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
26035 NGINX configuration.
26039 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
26040 Specifies a command which will be invoked to format the content of about
26041 pages (both top-level and for each repository).
26043 Defaults to @samp{""}.
26047 @deftypevr {@code{cgit-configuration} parameter} string agefile
26048 Specifies a path, relative to each repository path, which can be used to
26049 specify the date and time of the youngest commit in the repository.
26051 Defaults to @samp{""}.
26055 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
26056 Specifies a command that will be invoked for authenticating repository
26059 Defaults to @samp{""}.
26063 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
26064 Flag which, when set to @samp{age}, enables date ordering in the branch
26065 ref list, and when set @samp{name} enables ordering by branch name.
26067 Defaults to @samp{"name"}.
26071 @deftypevr {@code{cgit-configuration} parameter} string cache-root
26072 Path used to store the cgit cache entries.
26074 Defaults to @samp{"/var/cache/cgit"}.
26078 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
26079 Number which specifies the time-to-live, in minutes, for the cached
26080 version of repository pages accessed with a fixed SHA1.
26082 Defaults to @samp{-1}.
26086 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
26087 Number which specifies the time-to-live, in minutes, for the cached
26088 version of repository pages accessed without a fixed SHA1.
26090 Defaults to @samp{5}.
26094 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
26095 Number which specifies the time-to-live, in minutes, for the cached
26096 version of the repository summary page.
26098 Defaults to @samp{5}.
26102 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
26103 Number which specifies the time-to-live, in minutes, for the cached
26104 version of the repository index page.
26106 Defaults to @samp{5}.
26110 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
26111 Number which specifies the time-to-live, in minutes, for the result of
26112 scanning a path for Git repositories.
26114 Defaults to @samp{15}.
26118 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
26119 Number which specifies the time-to-live, in minutes, for the cached
26120 version of the repository about page.
26122 Defaults to @samp{15}.
26126 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
26127 Number which specifies the time-to-live, in minutes, for the cached
26128 version of snapshots.
26130 Defaults to @samp{5}.
26134 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
26135 The maximum number of entries in the cgit cache. When set to @samp{0},
26136 caching is disabled.
26138 Defaults to @samp{0}.
26142 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
26143 Sort items in the repo list case sensitively.
26145 Defaults to @samp{#t}.
26149 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
26150 List of common prefixes which, when combined with a repository URL,
26151 generates valid clone URLs for the repository.
26153 Defaults to @samp{()}.
26157 @deftypevr {@code{cgit-configuration} parameter} list clone-url
26158 List of @code{clone-url} templates.
26160 Defaults to @samp{()}.
26164 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
26165 Command which will be invoked to format commit messages.
26167 Defaults to @samp{""}.
26171 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
26172 Flag which, when set to @samp{date}, enables strict date ordering in the
26173 commit log, and when set to @samp{topo} enables strict topological
26176 Defaults to @samp{"git log"}.
26180 @deftypevr {@code{cgit-configuration} parameter} file-object css
26181 URL which specifies the css document to include in all cgit pages.
26183 Defaults to @samp{"/share/cgit/cgit.css"}.
26187 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
26188 Specifies a command which will be invoked to format names and email
26189 address of committers, authors, and taggers, as represented in various
26190 places throughout the cgit interface.
26192 Defaults to @samp{""}.
26196 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
26197 Flag which, when set to @samp{#t}, will make cgit generate a HTML
26198 fragment suitable for embedding in other HTML pages.
26200 Defaults to @samp{#f}.
26204 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
26205 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
26206 commit history graph to the left of the commit messages in the
26207 repository log page.
26209 Defaults to @samp{#f}.
26213 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
26214 Flag which, when set to @samp{#t}, allows all filter settings to be
26215 overridden in repository-specific cgitrc files.
26217 Defaults to @samp{#f}.
26221 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
26222 Flag which, when set to @samp{#t}, allows users to follow a file in the
26225 Defaults to @samp{#f}.
26229 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
26230 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
26233 Defaults to @samp{#t}.
26237 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
26238 Flag which, when set to @samp{#t}, will make cgit generate extra links
26239 "summary", "commit", "tree" for each repo in the repository index.
26241 Defaults to @samp{#f}.
26245 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
26246 Flag which, when set to @samp{#t}, will make cgit display the owner of
26247 each repo in the repository index.
26249 Defaults to @samp{#t}.
26253 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
26254 Flag which, when set to @samp{#t}, will make cgit print the number of
26255 modified files for each commit on the repository log page.
26257 Defaults to @samp{#f}.
26261 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
26262 Flag which, when set to @samp{#t}, will make cgit print the number of
26263 added and removed lines for each commit on the repository log page.
26265 Defaults to @samp{#f}.
26269 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
26270 Flag which, when set to @code{#t}, will make cgit display remote
26271 branches in the summary and refs views.
26273 Defaults to @samp{#f}.
26277 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
26278 Flag which, when set to @code{1}, will make cgit use the subject of the
26279 parent commit as link text when generating links to parent commits in
26282 Defaults to @samp{#f}.
26286 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
26287 Flag which, when set to @samp{#t}, will make cgit use the subject of the
26288 parent commit as link text when generating links to parent commits in
26291 Defaults to @samp{#f}.
26295 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
26296 Flag which, when set to @samp{#t}, will make cgit generate linenumber
26297 links for plaintext blobs printed in the tree view.
26299 Defaults to @samp{#t}.
26303 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
26304 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
26305 set any repo specific settings.
26307 Defaults to @samp{#f}.
26311 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
26312 URL used as link to a shortcut icon for cgit.
26314 Defaults to @samp{"/favicon.ico"}.
26318 @deftypevr {@code{cgit-configuration} parameter} string footer
26319 The content of the file specified with this option will be included
26320 verbatim at the bottom of all pages (i.e.@: it replaces the standard
26321 "generated by..."@: message).
26323 Defaults to @samp{""}.
26327 @deftypevr {@code{cgit-configuration} parameter} string head-include
26328 The content of the file specified with this option will be included
26329 verbatim in the HTML HEAD section on all pages.
26331 Defaults to @samp{""}.
26335 @deftypevr {@code{cgit-configuration} parameter} string header
26336 The content of the file specified with this option will be included
26337 verbatim at the top of all pages.
26339 Defaults to @samp{""}.
26343 @deftypevr {@code{cgit-configuration} parameter} file-object include
26344 Name of a configfile to include before the rest of the current config-
26347 Defaults to @samp{""}.
26351 @deftypevr {@code{cgit-configuration} parameter} string index-header
26352 The content of the file specified with this option will be included
26353 verbatim above the repository index.
26355 Defaults to @samp{""}.
26359 @deftypevr {@code{cgit-configuration} parameter} string index-info
26360 The content of the file specified with this option will be included
26361 verbatim below the heading on the repository index page.
26363 Defaults to @samp{""}.
26367 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
26368 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
26369 in the servers timezone.
26371 Defaults to @samp{#f}.
26375 @deftypevr {@code{cgit-configuration} parameter} file-object logo
26376 URL which specifies the source of an image which will be used as a logo
26379 Defaults to @samp{"/share/cgit/cgit.png"}.
26383 @deftypevr {@code{cgit-configuration} parameter} string logo-link
26384 URL loaded when clicking on the cgit logo image.
26386 Defaults to @samp{""}.
26390 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
26391 Command which will be invoked to format the Owner column of the main
26394 Defaults to @samp{""}.
26398 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
26399 Number of items to display in atom feeds view.
26401 Defaults to @samp{10}.
26405 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
26406 Number of entries to list per page in "log" view.
26408 Defaults to @samp{50}.
26412 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
26413 Number of commit message characters to display in "log" view.
26415 Defaults to @samp{80}.
26419 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
26420 Specifies the number of entries to list per page on the repository index
26423 Defaults to @samp{50}.
26427 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
26428 Specifies the maximum number of repo description characters to display
26429 on the repository index page.
26431 Defaults to @samp{80}.
26435 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
26436 Specifies the maximum size of a blob to display HTML for in KBytes.
26438 Defaults to @samp{0}.
26442 @deftypevr {@code{cgit-configuration} parameter} string max-stats
26443 Maximum statistics period. Valid values are @samp{week},@samp{month},
26444 @samp{quarter} and @samp{year}.
26446 Defaults to @samp{""}.
26450 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
26451 Mimetype for the specified filename extension.
26453 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
26454 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
26455 "image/png") (svg "image/svg+xml"))}.
26459 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
26460 Specifies the file to use for automatic mimetype lookup.
26462 Defaults to @samp{""}.
26466 @deftypevr {@code{cgit-configuration} parameter} string module-link
26467 Text which will be used as the formatstring for a hyperlink when a
26468 submodule is printed in a directory listing.
26470 Defaults to @samp{""}.
26474 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
26475 If set to the value @samp{#t} caching will be disabled.
26477 Defaults to @samp{#f}.
26481 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
26482 If set to @samp{#t} showing full author email addresses will be
26485 Defaults to @samp{#f}.
26489 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
26490 Flag which, when set to @samp{#t}, will make cgit omit the standard
26491 header on all pages.
26493 Defaults to @samp{#f}.
26497 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
26498 A list of subdirectories inside of @code{repository-directory}, relative
26499 to it, that should loaded as Git repositories. An empty list means that
26500 all subdirectories will be loaded.
26502 Defaults to @samp{()}.
26506 @deftypevr {@code{cgit-configuration} parameter} file-object readme
26507 Text which will be used as default value for @code{cgit-repo-readme}.
26509 Defaults to @samp{""}.
26513 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
26514 If set to @code{#t} and @code{repository-directory} is enabled, if any
26515 repositories are found with a suffix of @code{.git}, this suffix will be
26516 removed for the URL and name.
26518 Defaults to @samp{#f}.
26522 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
26523 Maximum number of files to consider when detecting renames.
26525 Defaults to @samp{-1}.
26529 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
26530 The way in which repositories in each section are sorted.
26532 Defaults to @samp{""}.
26536 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
26537 Text used as content for the @code{robots} meta-tag.
26539 Defaults to @samp{("noindex" "nofollow")}.
26543 @deftypevr {@code{cgit-configuration} parameter} string root-desc
26544 Text printed below the heading on the repository index page.
26546 Defaults to @samp{"a fast webinterface for the git dscm"}.
26550 @deftypevr {@code{cgit-configuration} parameter} string root-readme
26551 The content of the file specified with this option will be included
26552 verbatim below the ``about'' link on the repository index page.
26554 Defaults to @samp{""}.
26558 @deftypevr {@code{cgit-configuration} parameter} string root-title
26559 Text printed as heading on the repository index page.
26561 Defaults to @samp{""}.
26565 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
26566 If set to @samp{#t} and repository-directory is enabled,
26567 repository-directory will recurse into directories whose name starts
26568 with a period. Otherwise, repository-directory will stay away from such
26569 directories, considered as ``hidden''. Note that this does not apply to
26570 the @file{.git} directory in non-bare repos.
26572 Defaults to @samp{#f}.
26576 @deftypevr {@code{cgit-configuration} parameter} list snapshots
26577 Text which specifies the default set of snapshot formats that cgit
26578 generates links for.
26580 Defaults to @samp{()}.
26584 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
26585 Name of the directory to scan for repositories (represents
26588 Defaults to @samp{"/srv/git"}.
26592 @deftypevr {@code{cgit-configuration} parameter} string section
26593 The name of the current repository section - all repositories defined
26594 after this option will inherit the current section name.
26596 Defaults to @samp{""}.
26600 @deftypevr {@code{cgit-configuration} parameter} string section-sort
26601 Flag which, when set to @samp{1}, will sort the sections on the
26602 repository listing by name.
26604 Defaults to @samp{""}.
26608 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
26609 A number which, if defined prior to repository-directory, specifies how
26610 many path elements from each repo path to use as a default section name.
26612 Defaults to @samp{0}.
26616 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
26617 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
26620 Defaults to @samp{#f}.
26624 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
26625 Specifies a command which will be invoked to format plaintext blobs in
26628 Defaults to @samp{""}.
26632 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
26633 Specifies the number of branches to display in the repository ``summary''
26636 Defaults to @samp{10}.
26640 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
26641 Specifies the number of log entries to display in the repository
26644 Defaults to @samp{10}.
26648 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
26649 Specifies the number of tags to display in the repository ``summary''
26652 Defaults to @samp{10}.
26656 @deftypevr {@code{cgit-configuration} parameter} string strict-export
26657 Filename which, if specified, needs to be present within the repository
26658 for cgit to allow access to that repository.
26660 Defaults to @samp{""}.
26664 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
26665 URL which, if specified, will be used as root for all cgit links.
26667 Defaults to @samp{"/"}.
26671 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
26672 A list of @dfn{cgit-repo} records to use with config.
26674 Defaults to @samp{()}.
26676 Available @code{repository-cgit-configuration} fields are:
26678 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
26679 A mask of snapshot formats for this repo that cgit generates links for,
26680 restricted by the global @code{snapshots} setting.
26682 Defaults to @samp{()}.
26686 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
26687 Override the default @code{source-filter}.
26689 Defaults to @samp{""}.
26693 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
26694 The relative URL used to access the repository.
26696 Defaults to @samp{""}.
26700 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
26701 Override the default @code{about-filter}.
26703 Defaults to @samp{""}.
26707 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
26708 Flag which, when set to @samp{age}, enables date ordering in the branch
26709 ref list, and when set to @samp{name} enables ordering by branch name.
26711 Defaults to @samp{""}.
26715 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
26716 A list of URLs which can be used to clone repo.
26718 Defaults to @samp{()}.
26722 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
26723 Override the default @code{commit-filter}.
26725 Defaults to @samp{""}.
26729 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
26730 Flag which, when set to @samp{date}, enables strict date ordering in the
26731 commit log, and when set to @samp{topo} enables strict topological
26734 Defaults to @samp{""}.
26738 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
26739 The name of the default branch for this repository. If no such branch
26740 exists in the repository, the first branch name (when sorted) is used as
26741 default instead. By default branch pointed to by HEAD, or ``master'' if
26742 there is no suitable HEAD.
26744 Defaults to @samp{""}.
26748 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
26749 The value to show as repository description.
26751 Defaults to @samp{""}.
26755 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
26756 The value to show as repository homepage.
26758 Defaults to @samp{""}.
26762 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
26763 Override the default @code{email-filter}.
26765 Defaults to @samp{""}.
26769 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
26770 A flag which can be used to disable the global setting
26771 @code{enable-commit-graph?}.
26773 Defaults to @samp{disabled}.
26777 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
26778 A flag which can be used to disable the global setting
26779 @code{enable-log-filecount?}.
26781 Defaults to @samp{disabled}.
26785 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
26786 A flag which can be used to disable the global setting
26787 @code{enable-log-linecount?}.
26789 Defaults to @samp{disabled}.
26793 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
26794 Flag which, when set to @code{#t}, will make cgit display remote
26795 branches in the summary and refs views.
26797 Defaults to @samp{disabled}.
26801 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
26802 A flag which can be used to override the global setting
26803 @code{enable-subject-links?}.
26805 Defaults to @samp{disabled}.
26809 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
26810 A flag which can be used to override the global setting
26811 @code{enable-html-serving?}.
26813 Defaults to @samp{disabled}.
26817 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
26818 Flag which, when set to @code{#t}, hides the repository from the
26821 Defaults to @samp{#f}.
26825 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
26826 Flag which, when set to @samp{#t}, ignores the repository.
26828 Defaults to @samp{#f}.
26832 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
26833 URL which specifies the source of an image which will be used as a logo
26834 on this repo’s pages.
26836 Defaults to @samp{""}.
26840 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
26841 URL loaded when clicking on the cgit logo image.
26843 Defaults to @samp{""}.
26847 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
26848 Override the default @code{owner-filter}.
26850 Defaults to @samp{""}.
26854 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
26855 Text which will be used as the formatstring for a hyperlink when a
26856 submodule is printed in a directory listing. The arguments for the
26857 formatstring are the path and SHA1 of the submodule commit.
26859 Defaults to @samp{""}.
26863 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
26864 Text which will be used as the formatstring for a hyperlink when a
26865 submodule with the specified subdirectory path is printed in a directory
26868 Defaults to @samp{()}.
26872 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
26873 Override the default maximum statistics period.
26875 Defaults to @samp{""}.
26879 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
26880 The value to show as repository name.
26882 Defaults to @samp{""}.
26886 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
26887 A value used to identify the owner of the repository.
26889 Defaults to @samp{""}.
26893 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
26894 An absolute path to the repository directory.
26896 Defaults to @samp{""}.
26900 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
26901 A path (relative to repo) which specifies a file to include verbatim as
26902 the ``About'' page for this repo.
26904 Defaults to @samp{""}.
26908 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
26909 The name of the current repository section - all repositories defined
26910 after this option will inherit the current section name.
26912 Defaults to @samp{""}.
26916 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
26917 Extra options will be appended to cgitrc file.
26919 Defaults to @samp{()}.
26925 @deftypevr {@code{cgit-configuration} parameter} list extra-options
26926 Extra options will be appended to cgitrc file.
26928 Defaults to @samp{()}.
26933 @c %end of fragment
26935 However, it could be that you just want to get a @code{cgitrc} up and
26936 running. In that case, you can pass an @code{opaque-cgit-configuration}
26937 as a record to @code{cgit-service-type}. As its name indicates, an
26938 opaque configuration does not have easy reflective capabilities.
26940 Available @code{opaque-cgit-configuration} fields are:
26942 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
26946 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
26947 The contents of the @code{cgitrc}, as a string.
26950 For example, if your @code{cgitrc} is just the empty string, you
26951 could instantiate a cgit service like this:
26954 (service cgit-service-type
26955 (opaque-cgit-configuration
26959 @subsubheading Gitolite Service
26961 @cindex Gitolite service
26962 @cindex Git, hosting
26963 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
26964 repositories on a central server.
26966 Gitolite can handle multiple repositories and users, and supports flexible
26967 configuration of the permissions for the users on the repositories.
26969 The following example will configure Gitolite using the default @code{git}
26970 user, and the provided SSH public key.
26973 (service gitolite-service-type
26974 (gitolite-configuration
26975 (admin-pubkey (plain-file
26977 "ssh-rsa AAAA... guix@@example.com"))))
26980 Gitolite is configured through a special admin repository which you can clone,
26981 for example, if you setup Gitolite on @code{example.com}, you would run the
26982 following command to clone the admin repository.
26985 git clone git@@example.com:gitolite-admin
26988 When the Gitolite service is activated, the provided @code{admin-pubkey} will
26989 be inserted in to the @file{keydir} directory in the gitolite-admin
26990 repository. If this results in a change in the repository, it will be
26991 committed using the message ``gitolite setup by GNU Guix''.
26993 @deftp {Data Type} gitolite-configuration
26994 Data type representing the configuration for @code{gitolite-service-type}.
26997 @item @code{package} (default: @var{gitolite})
26998 Gitolite package to use.
27000 @item @code{user} (default: @var{git})
27001 User to use for Gitolite. This will be user that you use when accessing
27004 @item @code{group} (default: @var{git})
27005 Group to use for Gitolite.
27007 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
27008 Directory in which to store the Gitolite configuration and repositories.
27010 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
27011 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
27012 representing the configuration for Gitolite.
27014 @item @code{admin-pubkey} (default: @var{#f})
27015 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
27016 setup Gitolite. This will be inserted in to the @file{keydir} directory
27017 within the gitolite-admin repository.
27019 To specify the SSH key as a string, use the @code{plain-file} function.
27022 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
27028 @deftp {Data Type} gitolite-rc-file
27029 Data type representing the Gitolite RC file.
27032 @item @code{umask} (default: @code{#o0077})
27033 This controls the permissions Gitolite sets on the repositories and their
27036 A value like @code{#o0027} will give read access to the group used by Gitolite
27037 (by default: @code{git}). This is necessary when using Gitolite with software
27038 like cgit or gitweb.
27040 @item @code{git-config-keys} (default: @code{""})
27041 Gitolite allows you to set git config values using the @samp{config} keyword. This
27042 setting allows control over the config keys to accept.
27044 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
27045 Set the role names allowed to be used by users running the perms command.
27047 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
27048 This setting controls the commands and features to enable within Gitolite.
27054 @node Game Services
27055 @subsection Game Services
27057 @subsubheading The Battle for Wesnoth Service
27059 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
27060 based tactical strategy game, with several single player campaigns, and
27061 multiplayer games (both networked and local).
27063 @defvar {Scheme Variable} wesnothd-service-type
27064 Service type for the wesnothd service. Its value must be a
27065 @code{wesnothd-configuration} object. To run wesnothd in the default
27066 configuration, instantiate it as:
27069 (service wesnothd-service-type)
27073 @deftp {Data Type} wesnothd-configuration
27074 Data type representing the configuration of @command{wesnothd}.
27077 @item @code{package} (default: @code{wesnoth-server})
27078 The wesnoth server package to use.
27080 @item @code{port} (default: @code{15000})
27081 The port to bind the server to.
27086 @node PAM Mount Service
27087 @subsection PAM Mount Service
27090 The @code{(gnu services pam-mount)} module provides a service allowing
27091 users to mount volumes when they log in. It should be able to mount any
27092 volume format supported by the system.
27094 @defvar {Scheme Variable} pam-mount-service-type
27095 Service type for PAM Mount support.
27098 @deftp {Data Type} pam-mount-configuration
27099 Data type representing the configuration of PAM Mount.
27101 It takes the following parameters:
27105 The configuration rules that will be used to generate
27106 @file{/etc/security/pam_mount.conf.xml}.
27108 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
27109 Guile Reference Manual}), and the the default ones don't mount anything
27110 for anyone at login:
27113 `((debug (@@ (enable "0")))
27114 (mntoptions (@@ (allow ,(string-join
27115 '("nosuid" "nodev" "loop"
27116 "encryption" "fsck" "nonempty"
27117 "allow_root" "allow_other")
27119 (mntoptions (@@ (require "nosuid,nodev")))
27120 (logout (@@ (wait "0")
27124 (mkmountpoint (@@ (enable "1")
27128 Some @code{volume} elements must be added to automatically mount volumes
27129 at login. Here's an example allowing the user @code{alice} to mount her
27130 encrypted @env{HOME} directory and allowing the user @code{bob} to mount
27131 the partition where he stores his data:
27134 (define pam-mount-rules
27135 `((debug (@@ (enable "0")))
27136 (volume (@@ (user "alice")
27139 (mountpoint "/home/alice")))
27140 (volume (@@ (user "bob")
27143 (mountpoint "/home/bob/data")
27144 (options "defaults,autodefrag,compress")))
27145 (mntoptions (@@ (allow ,(string-join
27146 '("nosuid" "nodev" "loop"
27147 "encryption" "fsck" "nonempty"
27148 "allow_root" "allow_other")
27150 (mntoptions (@@ (require "nosuid,nodev")))
27151 (logout (@@ (wait "0")
27155 (mkmountpoint (@@ (enable "1")
27156 (remove "true")))))
27158 (service pam-mount-service-type
27159 (pam-mount-configuration
27160 (rules pam-mount-rules)))
27163 The complete list of possible options can be found in the man page for
27164 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
27169 @node Guix Services
27170 @subsection Guix Services
27172 @subsubheading Guix Data Service
27173 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
27174 and provides data about GNU Guix. This includes information about
27175 packages, derivations and lint warnings.
27177 The data is stored in a PostgreSQL database, and available through a web
27180 @defvar {Scheme Variable} guix-data-service-type
27181 Service type for the Guix Data Service. Its value must be a
27182 @code{guix-data-service-configuration} object. The service optionally
27183 extends the getmail service, as the guix-commits mailing list is used to
27184 find out about changes in the Guix git repository.
27187 @deftp {Data Type} guix-data-service-configuration
27188 Data type representing the configuration of the Guix Data Service.
27191 @item @code{package} (default: @code{guix-data-service})
27192 The Guix Data Service package to use.
27194 @item @code{user} (default: @code{"guix-data-service"})
27195 The system user to run the service as.
27197 @item @code{group} (default: @code{"guix-data-service"})
27198 The system group to run the service as.
27200 @item @code{port} (default: @code{8765})
27201 The port to bind the web service to.
27203 @item @code{host} (default: @code{"127.0.0.1"})
27204 The host to bind the web service to.
27206 @item @code{getmail-idle-mailboxes} (default: @code{#f})
27207 If set, this is the list of mailboxes that the getmail service will be
27208 configured to listen to.
27210 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
27211 If set, this is the @code{getmail-retriever-configuration} object with
27212 which to configure getmail to fetch mail from the guix-commits mailing
27215 @item @code{extra-options} (default: @var{'()})
27216 Extra command line options for @code{guix-data-service}.
27218 @item @code{extra-process-jobs-options} (default: @var{'()})
27219 Extra command line options for @code{guix-data-service-process-jobs}.
27224 @node Linux Services
27225 @subsection Linux Services
27228 @cindex out of memory killer
27230 @cindex early out of memory daemon
27231 @subsubheading Early OOM Service
27233 @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
27234 Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
27235 space and provides a more responsive and configurable alternative to the
27236 in-kernel OOM killer. It is useful to prevent the system from becoming
27237 unresponsive when it runs out of memory.
27239 @deffn {Scheme Variable} earlyoom-service-type
27240 The service type for running @command{earlyoom}, the Early OOM daemon.
27241 Its value must be a @code{earlyoom-configuration} object, described
27242 below. The service can be instantiated in its default configuration
27246 (service earlyoom-service-type)
27250 @deftp {Data Type} earlyoom-configuration
27251 This is the configuration record for the @code{earlyoom-service-type}.
27254 @item @code{earlyoom} (default: @var{earlyoom})
27255 The Earlyoom package to use.
27257 @item @code{minimum-available-memory} (default: @code{10})
27258 The threshold for the minimum @emph{available} memory, in percentages.
27260 @item @code{minimum-free-swap} (default: @code{10})
27261 The threshold for the minimum free swap memory, in percentages.
27263 @item @code{prefer-regexp} (default: @code{#f})
27264 A regular expression (as a string) to match the names of the processes
27265 that should be preferably killed.
27267 @item @code{avoid-regexp} (default: @code{#f})
27268 A regular expression (as a string) to match the names of the processes
27269 that should @emph{not} be killed.
27271 @item @code{memory-report-interval} (default: @code{0})
27272 The interval in seconds at which a memory report is printed. It is
27273 disabled by default.
27275 @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
27276 A boolean indicating whether the positive adjustments set in
27277 @file{/proc/*/oom_score_adj}.
27279 @item @code{show-debug-messages?} (default: @code{#f})
27280 A boolean indicating whether debug messages should be printed. The logs
27281 are saved at @file{/var/log/earlyoom.log}.
27283 @item @code{send-notification-command} (default: @code{#f})
27284 This can be used to provide a custom command used for sending
27290 @cindex kernel module loader
27291 @subsubheading Kernel Module Loader Service
27293 The kernel module loader service allows one to load loadable kernel
27294 modules at boot. This is especially useful for modules that don't
27295 autoload and need to be manually loaded, as it's the case with
27298 @deffn {Scheme Variable} kernel-module-loader-service-type
27299 The service type for loading loadable kernel modules at boot with
27300 @command{modprobe}. Its value must be a list of strings representing
27301 module names. For example loading the drivers provided by
27302 @code{ddcci-driver-linux}, in debugging mode by passing some module
27303 parameters, can be done as follow:
27306 (use-modules (gnu) (gnu services))
27307 (use-package-modules linux)
27308 (use-service-modules linux)
27310 (define ddcci-config
27311 (plain-file "ddcci.conf"
27312 "options ddcci dyndbg delay=120"))
27316 (services (cons* (service kernel-module-loader-service-type
27317 '("ddcci" "ddcci_backlight"))
27318 (simple-service 'ddcci-config etc-service-type
27319 (list `("modprobe.d/ddcci.conf"
27322 (kernel-loadable-modules (list ddcci-driver-linux)))
27327 @cindex compressed swap
27328 @cindex Compressed RAM-based block devices
27329 @subsubheading Zram Device Service
27331 The Zram device service provides a compressed swap device in system
27332 memory. The Linux Kernel documentation has more information about
27333 @uref{https://www.kernel.org/doc/html/latest/admin-guide/blockdev/zram.html,zram}
27336 @deffn {Scheme Variable} zram-device-service-type
27337 This service creates the zram block device, formats it as swap and
27338 enables it as a swap device. The service's value is a
27339 @code{zram-device-configuration} record.
27341 @deftp {Data Type} zram-device-configuration
27342 This is the data type representing the configuration for the zram-device
27346 @item @code{size} (default @var{"1G"})
27347 This is the amount of space you wish to provide for the zram device. It
27348 accepts a string and can be a number of bytes or use a suffix, eg.:
27349 @var{"512M"} or @var{1024000}.
27350 @item @code{compression-algorithm} (default @var{'lzo})
27351 This is the compression algorithm you wish to use. It is difficult to
27352 list all the possible compression options, but common ones supported by
27353 Guix's Linux Libre Kernel include @var{'lzo}, @var{'lz4} and @var{'zstd}.
27354 @item @code{memory-limit} (default @var{0})
27355 This is the maximum amount of memory which the zram device can use.
27356 Setting it to '0' disables the limit. While it is generally expected
27357 that compression will be 2:1, it is possible that uncompressable data
27358 can be written to swap and this is a method to limit how much memory can
27359 be used. It accepts a string and can be a number of bytes or use a
27360 suffix, eg.: @var{"2G"}.
27361 @item @code{priority} (default @var{-1})
27362 This is the priority of the swap device created from the zram device.
27363 @code{swapon} accepts values between -1 and 32767, with higher values
27364 indicating higher priority. Higher priority swap will generally be used
27371 @node Hurd Services
27372 @subsection Hurd Services
27374 @defvr {Scheme Variable} hurd-console-service-type
27375 This service starts the fancy @code{VGA} console client on the Hurd.
27377 The service's value is a @code{hurd-console-configuration} record.
27380 @deftp {Data Type} hurd-console-configuration
27381 This is the data type representing the configuration for the
27382 hurd-console-service.
27385 @item @code{hurd} (default: @var{hurd})
27386 The Hurd package to use.
27390 @defvr {Scheme Variable} hurd-getty-service-type
27391 This service starts a tty using the Hurd @code{getty} program.
27393 The service's value is a @code{hurd-getty-configuration} record.
27396 @deftp {Data Type} hurd-getty-configuration
27397 This is the data type representing the configuration for the
27398 hurd-getty-service.
27401 @item @code{hurd} (default: @var{hurd})
27402 The Hurd package to use.
27405 The name of the console this Getty runs on---e.g., @code{"tty1"}.
27407 @item @code{baud-rate} (default: @code{38400})
27408 An integer specifying the baud rate of the tty.
27413 @node Miscellaneous Services
27414 @subsection Miscellaneous Services
27416 @cindex fingerprint
27417 @subsubheading Fingerprint Service
27419 The @code{(gnu services authentication)} module provides a DBus service to
27420 read and identify fingerprints via a fingerprint sensor.
27422 @defvr {Scheme Variable} fprintd-service-type
27423 The service type for @command{fprintd}, which provides the fingerprint
27424 reading capability.
27427 (service fprintd-service-type)
27432 @subsubheading System Control Service
27434 The @code{(gnu services sysctl)} provides a service to configure kernel
27435 parameters at boot.
27437 @defvr {Scheme Variable} sysctl-service-type
27438 The service type for @command{sysctl}, which modifies kernel parameters
27439 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
27443 (service sysctl-service-type
27444 (sysctl-configuration
27445 (settings '(("net.ipv4.ip_forward" . "1")))))
27449 @deftp {Data Type} sysctl-configuration
27450 The data type representing the configuration of @command{sysctl}.
27453 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
27454 The @command{sysctl} executable to use.
27456 @item @code{settings} (default: @code{'()})
27457 An association list specifies kernel parameters and their values.
27462 @subsubheading PC/SC Smart Card Daemon Service
27464 The @code{(gnu services security-token)} module provides the following service
27465 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
27466 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
27467 manager that coordinates communications with smart card readers, smart cards
27468 and cryptographic tokens that are connected to the system.
27470 @defvr {Scheme Variable} pcscd-service-type
27471 Service type for the @command{pcscd} service. Its value must be a
27472 @code{pcscd-configuration} object. To run pcscd in the default
27473 configuration, instantiate it as:
27476 (service pcscd-service-type)
27480 @deftp {Data Type} pcscd-configuration
27481 The data type representing the configuration of @command{pcscd}.
27484 @item @code{pcsc-lite} (default: @code{pcsc-lite})
27485 The pcsc-lite package that provides pcscd.
27486 @item @code{usb-drivers} (default: @code{(list ccid)})
27487 List of packages that provide USB drivers to pcscd. Drivers are expected to be
27488 under @file{pcsc/drivers} in the store directory of the package.
27493 @subsubheading Lirc Service
27495 The @code{(gnu services lirc)} module provides the following service.
27497 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
27498 [#:device #f] [#:driver #f] [#:config-file #f] @
27499 [#:extra-options '()]
27500 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
27501 decodes infrared signals from remote controls.
27503 Optionally, @var{device}, @var{driver} and @var{config-file}
27504 (configuration file name) may be specified. See @command{lircd} manual
27507 Finally, @var{extra-options} is a list of additional command-line options
27508 passed to @command{lircd}.
27512 @subsubheading Spice Service
27514 The @code{(gnu services spice)} module provides the following service.
27516 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
27517 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
27518 that enables sharing the clipboard with a vm and setting the guest display
27519 resolution when the graphical console window resizes.
27522 @cindex inputattach
27523 @subsubheading inputattach Service
27525 @cindex tablet input, for Xorg
27526 @cindex touchscreen input, for Xorg
27527 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
27528 use input devices such as Wacom tablets, touchscreens, or joysticks with the
27529 Xorg display server.
27531 @deffn {Scheme Variable} inputattach-service-type
27532 Type of a service that runs @command{inputattach} on a device and
27533 dispatches events from it.
27536 @deftp {Data Type} inputattach-configuration
27538 @item @code{device-type} (default: @code{"wacom"})
27539 The type of device to connect to. Run @command{inputattach --help}, from the
27540 @code{inputattach} package, to see the list of supported device types.
27542 @item @code{device} (default: @code{"/dev/ttyS0"})
27543 The device file to connect to the device.
27545 @item @code{baud-rate} (default: @code{#f})
27546 Baud rate to use for the serial connection.
27547 Should be a number or @code{#f}.
27549 @item @code{log-file} (default: @code{#f})
27550 If true, this must be the name of a file to log messages to.
27554 @subsubheading Dictionary Service
27556 The @code{(gnu services dict)} module provides the following service:
27558 @defvr {Scheme Variable} dicod-service-type
27559 This is the type of the service that runs the @command{dicod} daemon, an
27560 implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
27563 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
27564 Return a service that runs the @command{dicod} daemon, an implementation
27565 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
27567 The optional @var{config} argument specifies the configuration for
27568 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
27569 default it serves the GNU Collaborative International Dictionary of English.
27571 You can add @command{open localhost} to your @file{~/.dico} file to make
27572 @code{localhost} the default server for @command{dico} client
27573 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
27576 @deftp {Data Type} dicod-configuration
27577 Data type representing the configuration of dicod.
27580 @item @code{dico} (default: @var{dico})
27581 Package object of the GNU Dico dictionary server.
27583 @item @code{interfaces} (default: @var{'("localhost")})
27584 This is the list of IP addresses and ports and possibly socket file
27585 names to listen to (@pxref{Server Settings, @code{listen} directive,,
27586 dico, GNU Dico Manual}).
27588 @item @code{handlers} (default: @var{'()})
27589 List of @code{<dicod-handler>} objects denoting handlers (module instances).
27591 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
27592 List of @code{<dicod-database>} objects denoting dictionaries to be served.
27596 @deftp {Data Type} dicod-handler
27597 Data type representing a dictionary handler (module instance).
27601 Name of the handler (module instance).
27603 @item @code{module} (default: @var{#f})
27604 Name of the dicod module of the handler (instance). If it is @code{#f},
27605 the module has the same name as the handler.
27606 (@pxref{Modules,,, dico, GNU Dico Manual}).
27608 @item @code{options}
27609 List of strings or gexps representing the arguments for the module handler
27613 @deftp {Data Type} dicod-database
27614 Data type representing a dictionary database.
27618 Name of the database, will be used in DICT commands.
27620 @item @code{handler}
27621 Name of the dicod handler (module instance) used by this database
27622 (@pxref{Handlers,,, dico, GNU Dico Manual}).
27624 @item @code{complex?} (default: @var{#f})
27625 Whether the database configuration complex. The complex configuration
27626 will need a corresponding @code{<dicod-handler>} object, otherwise not.
27628 @item @code{options}
27629 List of strings or gexps representing the arguments for the database
27630 (@pxref{Databases,,, dico, GNU Dico Manual}).
27634 @defvr {Scheme Variable} %dicod-database:gcide
27635 A @code{<dicod-database>} object serving the GNU Collaborative International
27636 Dictionary of English using the @code{gcide} package.
27639 The following is an example @code{dicod-service} configuration.
27642 (dicod-service #:config
27643 (dicod-configuration
27644 (handlers (list (dicod-handler
27648 (list #~(string-append "dbdir=" #$wordnet))))))
27649 (databases (list (dicod-database
27652 (handler "wordnet")
27653 (options '("database=wn")))
27654 %dicod-database:gcide))))
27658 @subsubheading Docker Service
27660 The @code{(gnu services docker)} module provides the following services.
27662 @defvr {Scheme Variable} docker-service-type
27664 This is the type of the service that runs @url{https://www.docker.com,Docker},
27665 a daemon that can execute application bundles (sometimes referred to as
27666 ``containers'') in isolated environments.
27670 @deftp {Data Type} docker-configuration
27671 This is the data type representing the configuration of Docker and Containerd.
27675 @item @code{package} (default: @code{docker})
27676 The Docker package to use.
27678 @item @code{containerd} (default: @var{containerd})
27679 The Containerd package to use.
27681 @item @code{proxy} (default @var{docker-libnetwork-cmd-proxy})
27682 The Docker user-land networking proxy package to use.
27684 @item @code{enable-proxy?} (default @code{#f})
27685 Enable or disable the use of the Docker user-land networking proxy.
27687 @item @code{debug?} (default @code{#f})
27688 Enable or disable debug output.
27690 @item @code{enable-iptables?} (default @code{#t})
27691 Enable or disable the addition of iptables rules.
27697 @subsubheading Auditd Service
27699 The @code{(gnu services auditd)} module provides the following service.
27701 @defvr {Scheme Variable} auditd-service-type
27703 This is the type of the service that runs
27704 @url{https://people.redhat.com/sgrubb/audit/,auditd},
27705 a daemon that tracks security-relevant information on your system.
27707 Examples of things that can be tracked:
27717 Failed login attempts
27724 @command{auditctl} from the @code{audit} package can be used in order
27725 to add or remove events to be tracked (until the next reboot).
27726 In order to permanently track events, put the command line arguments
27727 of auditctl into a file called @code{audit.rules} in the configuration
27728 directory (see below).
27729 @command{aureport} from the @code{audit} package can be used in order
27730 to view a report of all recorded events.
27731 The audit daemon by default logs into the file
27732 @file{/var/log/audit.log}.
27736 @deftp {Data Type} auditd-configuration
27737 This is the data type representing the configuration of auditd.
27741 @item @code{audit} (default: @code{audit})
27742 The audit package to use.
27744 @item @code{configuration-directory} (default: @code{%default-auditd-configuration-directory})
27745 The directory containing the configuration file for the audit package, which
27746 must be named @code{auditd.conf}, and optionally some audit rules to
27747 instantiate on startup.
27752 @defvr {Scheme Variable} singularity-service-type
27753 This is the type of the service that allows you to run
27754 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
27755 create and run application bundles (aka. ``containers''). The value for this
27756 service is the Singularity package to use.
27758 The service does not install a daemon; instead, it installs helper programs as
27759 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
27760 @command{singularity run} and similar commands.
27764 @subsubheading R-Shiny service
27766 The @code{(gnu services science)} module provides the following service.
27768 @defvr {Scheme Variable} rshiny-service-type
27770 This is a type of service which is used to run a webapp created with
27771 @code{r-shiny}. This service sets the @code{R_LIBS_USER} environment
27772 variable and runs the provided script to call @code{runApp}.
27774 @deftp {Data Type} rshiny-configuration
27775 This is the data type representing the configuration of rshiny.
27779 @item @code{package} (default: @code{r-shiny})
27780 The package to use.
27782 @item @code{binary} (defaunlt @code{"rshiny"})
27783 The name of the binary or shell script located at @code{package/bin/} to
27784 run when the service is run.
27786 The common way to create this file is as follows:
27790 (let* ((out (assoc-ref %outputs "out"))
27791 (targetdir (string-append out "/share/" ,name))
27792 (app (string-append out "/bin/" ,name))
27793 (Rbin (string-append (assoc-ref %build-inputs "r-min")
27796 (mkdir-p (string-append out "/bin"))
27797 (call-with-output-file app
27803 runApp(launch.browser=0, port=4202)~%\n"
27813 @subsubheading Nix service
27815 The @code{(gnu services nix)} module provides the following service.
27817 @defvr {Scheme Variable} nix-service-type
27819 This is the type of the service that runs build daemon of the
27820 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
27824 (use-modules (gnu))
27825 (use-service-modules nix)
27826 (use-package-modules package-management)
27830 (packages (append (list nix)
27833 (services (append (list (service nix-service-type))
27837 After @command{guix system reconfigure} configure Nix for your user:
27840 @item Add a Nix channel and update it. See
27841 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
27843 @item Create a symlink to your profile and activate Nix profile:
27847 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
27848 $ source /run/current-system/profile/etc/profile.d/nix.sh
27853 @deftp {Data Type} nix-configuration
27854 This data type represents the configuration of the Nix daemon.
27857 @item @code{nix} (default: @code{nix})
27858 The Nix package to use.
27860 @item @code{sandbox} (default: @code{#t})
27861 Specifies whether builds are sandboxed by default.
27863 @item @code{build-sandbox-items} (default: @code{'()})
27864 This is a list of strings or objects appended to the
27865 @code{build-sandbox-items} field of the configuration file.
27867 @item @code{extra-config} (default: @code{'()})
27868 This is a list of strings or objects appended to the configuration file.
27869 It is used to pass extra text to be added verbatim to the configuration
27872 @item @code{extra-options} (default: @code{'()})
27873 Extra command line options for @code{nix-service-type}.
27877 @node Setuid Programs
27878 @section Setuid Programs
27880 @cindex setuid programs
27881 Some programs need to run with ``root'' privileges, even when they are
27882 launched by unprivileged users. A notorious example is the
27883 @command{passwd} program, which users can run to change their
27884 password, and which needs to access the @file{/etc/passwd} and
27885 @file{/etc/shadow} files---something normally restricted to root, for
27886 obvious security reasons. To address that, these executables are
27887 @dfn{setuid-root}, meaning that they always run with root privileges
27888 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
27889 for more info about the setuid mechanism).
27891 The store itself @emph{cannot} contain setuid programs: that would be a
27892 security issue since any user on the system can write derivations that
27893 populate the store (@pxref{The Store}). Thus, a different mechanism is
27894 used: instead of changing the setuid bit directly on files that are in
27895 the store, we let the system administrator @emph{declare} which programs
27896 should be setuid root.
27898 The @code{setuid-programs} field of an @code{operating-system}
27899 declaration contains a list of G-expressions denoting the names of
27900 programs to be setuid-root (@pxref{Using the Configuration System}).
27901 For instance, the @command{passwd} program, which is part of the Shadow
27902 package, can be designated by this G-expression (@pxref{G-Expressions}):
27905 #~(string-append #$shadow "/bin/passwd")
27908 A default set of setuid programs is defined by the
27909 @code{%setuid-programs} variable of the @code{(gnu system)} module.
27911 @defvr {Scheme Variable} %setuid-programs
27912 A list of G-expressions denoting common programs that are setuid-root.
27914 The list includes commands such as @command{passwd}, @command{ping},
27915 @command{su}, and @command{sudo}.
27918 Under the hood, the actual setuid programs are created in the
27919 @file{/run/setuid-programs} directory at system activation time. The
27920 files in this directory refer to the ``real'' binaries, which are in the
27923 @node X.509 Certificates
27924 @section X.509 Certificates
27926 @cindex HTTPS, certificates
27927 @cindex X.509 certificates
27929 Web servers available over HTTPS (that is, HTTP over the transport-layer
27930 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
27931 that the client can then use to @emph{authenticate} the server. To do
27932 that, clients verify that the server's certificate is signed by a
27933 so-called @dfn{certificate authority} (CA). But to verify the CA's
27934 signature, clients must have first acquired the CA's certificate.
27936 Web browsers such as GNU@tie{}IceCat include their own set of CA
27937 certificates, such that they are able to verify CA signatures
27940 However, most other programs that can talk HTTPS---@command{wget},
27941 @command{git}, @command{w3m}, etc.---need to be told where CA
27942 certificates can be found.
27944 @cindex @code{nss-certs}
27945 In Guix, this is done by adding a package that provides certificates
27946 to the @code{packages} field of the @code{operating-system} declaration
27947 (@pxref{operating-system Reference}). Guix includes one such package,
27948 @code{nss-certs}, which is a set of CA certificates provided as part of
27949 Mozilla's Network Security Services.
27951 Note that it is @emph{not} part of @code{%base-packages}, so you need to
27952 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
27953 most applications and libraries look for certificates by default, points
27954 to the certificates installed globally.
27956 Unprivileged users, including users of Guix on a foreign distro,
27957 can also install their own certificate package in
27958 their profile. A number of environment variables need to be defined so
27959 that applications and libraries know where to find them. Namely, the
27960 OpenSSL library honors the @env{SSL_CERT_DIR} and @env{SSL_CERT_FILE}
27961 variables. Some applications add their own environment variables; for
27962 instance, the Git version control system honors the certificate bundle
27963 pointed to by the @env{GIT_SSL_CAINFO} environment variable. Thus, you
27964 would typically run something like:
27967 guix install nss-certs
27968 export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
27969 export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
27970 export GIT_SSL_CAINFO="$SSL_CERT_FILE"
27973 As another example, R requires the @env{CURL_CA_BUNDLE} environment
27974 variable to point to a certificate bundle, so you would have to run
27975 something like this:
27978 guix install nss-certs
27979 export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
27982 For other applications you may want to look up the required environment
27983 variable in the relevant documentation.
27986 @node Name Service Switch
27987 @section Name Service Switch
27989 @cindex name service switch
27991 The @code{(gnu system nss)} module provides bindings to the
27992 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
27993 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
27994 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
27995 extended with new ``name'' lookup methods for system databases, which
27996 includes host names, service names, user accounts, and more (@pxref{Name
27997 Service Switch, System Databases and Name Service Switch,, libc, The GNU
27998 C Library Reference Manual}).
28000 The NSS configuration specifies, for each system database, which lookup
28001 method is to be used, and how the various methods are chained
28002 together---for instance, under which circumstances NSS should try the
28003 next method in the list. The NSS configuration is given in the
28004 @code{name-service-switch} field of @code{operating-system} declarations
28005 (@pxref{operating-system Reference, @code{name-service-switch}}).
28008 @cindex .local, host name lookup
28009 As an example, the declaration below configures the NSS to use the
28010 @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
28011 back-end}, which supports host name lookups over multicast DNS (mDNS)
28012 for host names ending in @code{.local}:
28015 (name-service-switch
28016 (hosts (list %files ;first, check /etc/hosts
28018 ;; If the above did not succeed, try
28019 ;; with 'mdns_minimal'.
28021 (name "mdns_minimal")
28023 ;; 'mdns_minimal' is authoritative for
28024 ;; '.local'. When it returns "not found",
28025 ;; no need to try the next methods.
28026 (reaction (lookup-specification
28027 (not-found => return))))
28029 ;; Then fall back to DNS.
28033 ;; Finally, try with the "full" 'mdns'.
28038 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
28039 contains this configuration, so you will not have to type it if all you
28040 want is to have @code{.local} host lookup working.
28042 Note that, in this case, in addition to setting the
28043 @code{name-service-switch} of the @code{operating-system} declaration,
28044 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
28045 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
28046 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
28047 to the name service cache daemon (@pxref{Base Services,
28048 @code{nscd-service}}).
28050 For convenience, the following variables provide typical NSS
28053 @defvr {Scheme Variable} %default-nss
28054 This is the default name service switch configuration, a
28055 @code{name-service-switch} object.
28058 @defvr {Scheme Variable} %mdns-host-lookup-nss
28059 This is the name service switch configuration with support for host name
28060 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
28063 The reference for name service switch configuration is given below. It
28064 is a direct mapping of the configuration file format of the C library , so
28065 please refer to the C library manual for more information (@pxref{NSS
28066 Configuration File,,, libc, The GNU C Library Reference Manual}).
28067 Compared to the configuration file format of libc NSS, it has the advantage
28068 not only of adding this warm parenthetic feel that we like, but also
28069 static checks: you will know about syntax errors and typos as soon as you
28070 run @command{guix system}.
28072 @deftp {Data Type} name-service-switch
28074 This is the data type representation the configuration of libc's name
28075 service switch (NSS). Each field below represents one of the supported
28092 The system databases handled by the NSS. Each of these fields must be a
28093 list of @code{<name-service>} objects (see below).
28097 @deftp {Data Type} name-service
28099 This is the data type representing an actual name service and the
28100 associated lookup action.
28104 A string denoting the name service (@pxref{Services in the NSS
28105 configuration,,, libc, The GNU C Library Reference Manual}).
28107 Note that name services listed here must be visible to nscd. This is
28108 achieved by passing the @code{#:name-services} argument to
28109 @code{nscd-service} the list of packages providing the needed name
28110 services (@pxref{Base Services, @code{nscd-service}}).
28113 An action specified using the @code{lookup-specification} macro
28114 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
28115 Reference Manual}). For example:
28118 (lookup-specification (unavailable => continue)
28119 (success => return))
28124 @node Initial RAM Disk
28125 @section Initial RAM Disk
28128 @cindex initial RAM disk
28129 For bootstrapping purposes, the Linux-Libre kernel is passed an
28130 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
28131 root file system as well as an initialization script. The latter is
28132 responsible for mounting the real root file system, and for loading any
28133 kernel modules that may be needed to achieve that.
28135 The @code{initrd-modules} field of an @code{operating-system}
28136 declaration allows you to specify Linux-libre kernel modules that must
28137 be available in the initrd. In particular, this is where you would list
28138 modules needed to actually drive the hard disk where your root partition
28139 is---although the default value of @code{initrd-modules} should cover
28140 most use cases. For example, assuming you need the @code{megaraid_sas}
28141 module in addition to the default modules to be able to access your root
28142 file system, you would write:
28147 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
28150 @defvr {Scheme Variable} %base-initrd-modules
28151 This is the list of kernel modules included in the initrd by default.
28154 Furthermore, if you need lower-level customization, the @code{initrd}
28155 field of an @code{operating-system} declaration allows
28156 you to specify which initrd you would like to use. The @code{(gnu
28157 system linux-initrd)} module provides three ways to build an initrd: the
28158 high-level @code{base-initrd} procedure and the low-level
28159 @code{raw-initrd} and @code{expression->initrd} procedures.
28161 The @code{base-initrd} procedure is intended to cover most common uses.
28162 For example, if you want to add a bunch of kernel modules to be loaded
28163 at boot time, you can define the @code{initrd} field of the operating
28164 system declaration like this:
28167 (initrd (lambda (file-systems . rest)
28168 ;; Create a standard initrd but set up networking
28169 ;; with the parameters QEMU expects by default.
28170 (apply base-initrd file-systems
28171 #:qemu-networking? #t
28175 The @code{base-initrd} procedure also handles common use cases that
28176 involves using the system as a QEMU guest, or as a ``live'' system with
28177 volatile root file system.
28179 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
28180 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
28181 such as trying to guess which kernel modules and packages should be included
28182 to the initrd. An example use of @code{raw-initrd} is when a user has
28183 a custom Linux kernel configuration and default kernel modules included by
28184 @code{base-initrd} are not available.
28186 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
28187 honors several options passed on the Linux kernel command line
28188 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
28189 @code{-append} option of QEMU), notably:
28192 @item --load=@var{boot}
28193 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
28194 program, once it has mounted the root file system.
28196 Guix uses this option to yield control to a boot program that runs the
28197 service activation programs and then spawns the GNU@tie{}Shepherd, the
28198 initialization system.
28200 @item --root=@var{root}
28201 Mount @var{root} as the root file system. @var{root} can be a device
28202 name like @code{/dev/sda1}, a file system label, or a file system UUID.
28203 When unspecified, the device name from the root file system of the
28204 operating system declaration is used.
28206 @item --system=@var{system}
28207 Have @file{/run/booted-system} and @file{/run/current-system} point to
28210 @item modprobe.blacklist=@var{modules}@dots{}
28211 @cindex module, black-listing
28212 @cindex black list, of kernel modules
28213 Instruct the initial RAM disk as well as the @command{modprobe} command
28214 (from the kmod package) to refuse to load @var{modules}. @var{modules}
28215 must be a comma-separated list of module names---e.g.,
28216 @code{usbkbd,9pnet}.
28219 Start a read-eval-print loop (REPL) from the initial RAM disk before it
28220 tries to load kernel modules and to mount the root file system. Our
28221 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
28222 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
28223 Manual}, for more information on Guile's REPL.
28227 Now that you know all the features that initial RAM disks produced by
28228 @code{base-initrd} and @code{raw-initrd} provide,
28229 here is how to use it and customize it further.
28232 @cindex initial RAM disk
28233 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
28234 [#:linux-modules '()] [#:mapped-devices '()] @
28235 [#:keyboard-layout #f] @
28236 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
28237 Return a derivation that builds a raw initrd. @var{file-systems} is
28238 a list of file systems to be mounted by the initrd, possibly in addition to
28239 the root file system specified on the kernel command line via @option{--root}.
28240 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
28241 @var{mapped-devices} is a list of device mappings to realize before
28242 @var{file-systems} are mounted (@pxref{Mapped Devices}).
28243 @var{helper-packages} is a list of packages to be copied in the initrd. It may
28244 include @code{e2fsck/static} or other packages needed by the initrd to check
28245 the root file system.
28247 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
28248 the desired console keyboard layout. This is done before @var{mapped-devices}
28249 are set up and before @var{file-systems} are mounted such that, should the
28250 user need to enter a passphrase or use the REPL, this happens using the
28251 intended keyboard layout.
28253 When @var{qemu-networking?} is true, set up networking with the standard QEMU
28254 parameters. When @var{virtio?} is true, load additional modules so that the
28255 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
28257 When @var{volatile-root?} is true, the root file system is writable but any changes
28261 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
28262 [#:mapped-devices '()] [#:keyboard-layout #f] @
28263 [#:qemu-networking? #f] [#:volatile-root? #f] @
28264 [#:linux-modules '()]
28265 Return as a file-like object a generic initrd, with kernel
28266 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
28267 mounted by the initrd, possibly in addition to the root file system specified
28268 on the kernel command line via @option{--root}. @var{mapped-devices} is a list of device
28269 mappings to realize before @var{file-systems} are mounted.
28271 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
28272 the desired console keyboard layout. This is done before @var{mapped-devices}
28273 are set up and before @var{file-systems} are mounted such that, should the
28274 user need to enter a passphrase or use the REPL, this happens using the
28275 intended keyboard layout.
28277 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
28279 The initrd is automatically populated with all the kernel modules necessary
28280 for @var{file-systems} and for the given options. Additional kernel
28281 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
28282 loaded at boot time in the order in which they appear.
28285 Needless to say, the initrds we produce and use embed a
28286 statically-linked Guile, and the initialization program is a Guile
28287 program. That gives a lot of flexibility. The
28288 @code{expression->initrd} procedure builds such an initrd, given the
28289 program to run in that initrd.
28291 @deffn {Scheme Procedure} expression->initrd @var{exp} @
28292 [#:guile %guile-3.0-static-stripped] [#:name "guile-initrd"]
28293 Return as a file-like object a Linux initrd (a gzipped cpio archive)
28294 containing @var{guile} and that evaluates @var{exp}, a G-expression,
28295 upon booting. All the derivations referenced by @var{exp} are
28296 automatically copied to the initrd.
28299 @node Bootloader Configuration
28300 @section Bootloader Configuration
28303 @cindex boot loader
28305 The operating system supports multiple bootloaders. The bootloader is
28306 configured using @code{bootloader-configuration} declaration. All the
28307 fields of this structure are bootloader agnostic except for one field,
28308 @code{bootloader} that indicates the bootloader to be configured and
28311 Some of the bootloaders do not honor every field of
28312 @code{bootloader-configuration}. For instance, the extlinux
28313 bootloader does not support themes and thus ignores the @code{theme}
28316 @deftp {Data Type} bootloader-configuration
28317 The type of a bootloader configuration declaration.
28321 @item @code{bootloader}
28322 @cindex EFI, bootloader
28323 @cindex UEFI, bootloader
28324 @cindex BIOS, bootloader
28325 The bootloader to use, as a @code{bootloader} object. For now
28326 @code{grub-bootloader}, @code{grub-efi-bootloader},
28327 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
28329 @vindex grub-efi-bootloader
28330 @code{grub-efi-bootloader} allows to boot on modern systems using the
28331 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
28332 use if the installation image contains a @file{/sys/firmware/efi} directory
28333 when you boot it on your system.
28335 @vindex grub-bootloader
28336 @code{grub-bootloader} allows you to boot in particular Intel-based machines
28337 in ``legacy'' BIOS mode.
28339 @cindex ARM, bootloaders
28340 @cindex AArch64, bootloaders
28341 Available bootloaders are described in @code{(gnu bootloader @dots{})}
28342 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
28343 of bootloaders for a wide range of ARM and AArch64 systems, using the
28344 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
28346 @item @code{target}
28347 This is a string denoting the target onto which to install the
28350 The interpretation depends on the bootloader in question. For
28351 @code{grub-bootloader}, for example, it should be a device name understood by
28352 the bootloader @command{installer} command, such as @code{/dev/sda} or
28353 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
28354 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
28355 system, usually @file{/boot/efi}.
28357 @item @code{menu-entries} (default: @code{()})
28358 A possibly empty list of @code{menu-entry} objects (see below), denoting
28359 entries to appear in the bootloader menu, in addition to the current
28360 system entry and the entry pointing to previous system generations.
28362 @item @code{default-entry} (default: @code{0})
28363 The index of the default boot menu entry. Index 0 is for the entry of the
28366 @item @code{timeout} (default: @code{5})
28367 The number of seconds to wait for keyboard input before booting. Set to
28368 0 to boot immediately, and to -1 to wait indefinitely.
28370 @cindex keyboard layout, for the bootloader
28371 @item @code{keyboard-layout} (default: @code{#f})
28372 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
28373 layout, usually US@tie{}English (``qwerty'').
28375 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
28379 This option is currently ignored by bootloaders other than @code{grub} and
28383 @item @code{theme} (default: @var{#f})
28384 The bootloader theme object describing the theme to use. If no theme
28385 is provided, some bootloaders might use a default theme, that's true
28388 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
28389 The output terminals used for the bootloader boot menu, as a list of
28390 symbols. GRUB accepts the values: @code{console}, @code{serial},
28391 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
28392 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
28393 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
28394 configuration,,, grub,GNU GRUB manual}).
28396 @item @code{terminal-inputs} (default: @code{'()})
28397 The input terminals used for the bootloader boot menu, as a list of
28398 symbols. For GRUB, the default is the native platform terminal as
28399 determined at run-time. GRUB accepts the values: @code{console},
28400 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
28401 @code{usb_keyboard}. This field corresponds to the GRUB variable
28402 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
28405 @item @code{serial-unit} (default: @code{#f})
28406 The serial unit used by the bootloader, as an integer from 0 to 3.
28407 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
28408 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
28410 @item @code{serial-speed} (default: @code{#f})
28411 The speed of the serial interface, as an integer. For GRUB, the
28412 default value is chosen at run-time; currently GRUB chooses
28413 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
28420 Should you want to list additional boot menu entries @i{via} the
28421 @code{menu-entries} field above, you will need to create them with the
28422 @code{menu-entry} form. For example, imagine you want to be able to
28423 boot another distro (hard to imagine!), you can define a menu entry
28428 (label "The Other Distro")
28429 (linux "/boot/old/vmlinux-2.6.32")
28430 (linux-arguments '("root=/dev/sda2"))
28431 (initrd "/boot/old/initrd"))
28436 @deftp {Data Type} menu-entry
28437 The type of an entry in the bootloader menu.
28442 The label to show in the menu---e.g., @code{"GNU"}.
28444 @item @code{linux} (default: @code{#f})
28445 The Linux kernel image to boot, for example:
28448 (file-append linux-libre "/bzImage")
28451 For GRUB, it is also possible to specify a device explicitly in the
28452 file path using GRUB's device naming convention (@pxref{Naming
28453 convention,,, grub, GNU GRUB manual}), for example:
28456 "(hd0,msdos1)/boot/vmlinuz"
28459 If the device is specified explicitly as above, then the @code{device}
28460 field is ignored entirely.
28462 @item @code{linux-arguments} (default: @code{()})
28463 The list of extra Linux kernel command-line arguments---e.g.,
28464 @code{("console=ttyS0")}.
28466 @item @code{initrd} (default: @code{#f})
28467 A G-Expression or string denoting the file name of the initial RAM disk
28468 to use (@pxref{G-Expressions}).
28470 @item @code{device} (default: @code{#f})
28471 The device where the kernel and initrd are to be found---i.e., for GRUB,
28472 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
28474 This may be a file system label (a string), a file system UUID (a
28475 bytevector, @pxref{File Systems}), or @code{#f}, in which case
28476 the bootloader will search the device containing the file specified by
28477 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
28478 must @emph{not} be an OS device name such as @file{/dev/sda1}.
28480 @item @code{multiboot-kernel} (default: @code{#f})
28481 The kernel to boot in Multiboot-mode (@pxref{multiboot,,, grub, GNU GRUB
28482 manual}). When this field is set, a Multiboot menu-entry is generated.
28486 (file-append mach "/boot/gnumach")
28489 @item @code{multiboot-arguments} (default: @code{()})
28490 The list of extra command-line arguments for the multiboot-kernel.
28492 @item @code{multiboot-modules} (default: @code{()})
28493 The list of commands for loading Multiboot modules. For example:
28496 (list (list (file-append hurd "/hurd/ext2fs.static") "ext2fs"
28498 (list (file-append libc "/lib/ld.so.1") "exec"
28508 @c FIXME: Write documentation once it's stable.
28509 For now only GRUB has theme support. GRUB themes are created using
28510 the @code{grub-theme} form, which is not fully documented yet.
28512 @deftp {Data Type} grub-theme
28513 Data type representing the configuration of the GRUB theme.
28516 @item @code{gfxmode} (default: @code{'("auto")})
28517 The GRUB @code{gfxmode} to set (a list of screen resolution strings, see
28518 @pxref{gfxmode,,, grub, GNU GRUB manual}).
28522 @deffn {Scheme Procedure} grub-theme
28523 Return the default GRUB theme used by the operating system if no
28524 @code{theme} field is specified in @code{bootloader-configuration}
28527 It comes with a fancy background image displaying the GNU and Guix
28531 For example, to override the default resolution, you may use something
28536 (bootloader-configuration
28539 (inherit (grub-theme))
28540 (gfxmode '("1024x786x32" "auto"))))))
28543 @node Invoking guix system
28544 @section Invoking @code{guix system}
28546 Once you have written an operating system declaration as seen in the
28547 previous section, it can be @dfn{instantiated} using the @command{guix
28548 system} command. The synopsis is:
28551 guix system @var{options}@dots{} @var{action} @var{file}
28554 @var{file} must be the name of a file containing an
28555 @code{operating-system} declaration. @var{action} specifies how the
28556 operating system is instantiated. Currently the following values are
28561 Display available service type definitions that match the given regular
28562 expressions, sorted by relevance:
28568 $ guix system search console
28569 name: console-fonts
28570 location: gnu/services/base.scm:806:2
28571 extends: shepherd-root
28572 description: Install the given fonts on the specified ttys (fonts are per
28573 + virtual console on GNU/Linux). The value of this service is a list of
28574 + tty/font pairs. The font can be the name of a font provided by the `kbd'
28575 + package or any valid argument to `setfont', as in this example:
28577 + '(("tty1" . "LatGrkCyr-8x16")
28578 + ("tty2" . (file-append
28580 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
28581 + ("tty3" . (file-append
28583 + "/share/consolefonts/ter-132n"))) ; for HDPI
28587 location: gnu/services/base.scm:1190:2
28588 extends: shepherd-root
28589 description: Provide console login using the `mingetty' program.
28593 location: gnu/services/base.scm:860:2
28595 description: Provide a console log-in service as specified by its
28596 + configuration value, a `login-configuration' object.
28602 As for @command{guix package --search}, the result is written in
28603 @code{recutils} format, which makes it easy to filter the output
28604 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
28607 Build the operating system described in @var{file}, activate it, and
28608 switch to it@footnote{This action (and the related actions
28609 @code{switch-generation} and @code{roll-back}) are usable only on
28610 systems already running Guix System.}.
28613 @c The paragraph below refers to the problem discussed at
28614 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
28615 It is highly recommended to run @command{guix pull} once before you run
28616 @command{guix system reconfigure} for the first time (@pxref{Invoking
28617 guix pull}). Failing to do that you would see an older version of Guix
28618 once @command{reconfigure} has completed.
28621 This effects all the configuration specified in @var{file}: user
28622 accounts, system services, global package list, setuid programs, etc.
28623 The command starts system services specified in @var{file} that are not
28624 currently running; if a service is currently running this command will
28625 arrange for it to be upgraded the next time it is stopped (e.g.@: by
28626 @code{herd stop X} or @code{herd restart X}).
28628 This command creates a new generation whose number is one greater than
28629 the current generation (as reported by @command{guix system
28630 list-generations}). If that generation already exists, it will be
28631 overwritten. This behavior mirrors that of @command{guix package}
28632 (@pxref{Invoking guix package}).
28634 It also adds a bootloader menu entry for the new OS configuration,
28635 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
28636 entries for older configurations to a submenu, allowing you to choose
28637 an older system generation at boot time should you need it.
28639 @cindex provenance tracking, of the operating system
28640 Upon completion, the new system is deployed under
28641 @file{/run/current-system}. This directory contains @dfn{provenance
28642 meta-data}: the list of channels in use (@pxref{Channels}) and
28643 @var{file} itself, when available. You can view it by running:
28646 guix system describe
28649 This information is useful should you later want to inspect how this
28650 particular generation was built. In fact, assuming @var{file} is
28651 self-contained, you can later rebuild generation @var{n} of your
28652 operating system with:
28655 guix time-machine \
28656 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
28657 system reconfigure \
28658 /var/guix/profiles/system-@var{n}-link/configuration.scm
28661 You can think of it as some sort of built-in version control! Your
28662 system is not just a binary artifact: @emph{it carries its own source}.
28663 @xref{Service Reference, @code{provenance-service-type}}, for more
28664 information on provenance tracking.
28666 By default, @command{reconfigure} @emph{prevents you from downgrading
28667 your system}, which could (re)introduce security vulnerabilities and
28668 also cause problems with ``stateful'' services such as database
28669 management systems. You can override that behavior by passing
28670 @option{--allow-downgrades}.
28672 @item switch-generation
28673 @cindex generations
28674 Switch to an existing system generation. This action atomically
28675 switches the system profile to the specified system generation. It
28676 also rearranges the system's existing bootloader menu entries. It
28677 makes the menu entry for the specified system generation the default,
28678 and it moves the entries for the other generations to a submenu, if
28679 supported by the bootloader being used. The next time the system
28680 boots, it will use the specified system generation.
28682 The bootloader itself is not being reinstalled when using this
28683 command. Thus, the installed bootloader is used with an updated
28684 configuration file.
28686 The target generation can be specified explicitly by its generation
28687 number. For example, the following invocation would switch to system
28691 guix system switch-generation 7
28694 The target generation can also be specified relative to the current
28695 generation with the form @code{+N} or @code{-N}, where @code{+3} means
28696 ``3 generations ahead of the current generation,'' and @code{-1} means
28697 ``1 generation prior to the current generation.'' When specifying a
28698 negative value such as @code{-1}, you must precede it with @code{--} to
28699 prevent it from being parsed as an option. For example:
28702 guix system switch-generation -- -1
28705 Currently, the effect of invoking this action is @emph{only} to switch
28706 the system profile to an existing generation and rearrange the
28707 bootloader menu entries. To actually start using the target system
28708 generation, you must reboot after running this action. In the future,
28709 it will be updated to do the same things as @command{reconfigure},
28710 like activating and deactivating services.
28712 This action will fail if the specified generation does not exist.
28715 @cindex rolling back
28716 Switch to the preceding system generation. The next time the system
28717 boots, it will use the preceding system generation. This is the inverse
28718 of @command{reconfigure}, and it is exactly the same as invoking
28719 @command{switch-generation} with an argument of @code{-1}.
28721 Currently, as with @command{switch-generation}, you must reboot after
28722 running this action to actually start using the preceding system
28725 @item delete-generations
28726 @cindex deleting system generations
28727 @cindex saving space
28728 Delete system generations, making them candidates for garbage collection
28729 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
28732 This works in the same way as @samp{guix package --delete-generations}
28733 (@pxref{Invoking guix package, @option{--delete-generations}}). With no
28734 arguments, all system generations but the current one are deleted:
28737 guix system delete-generations
28740 You can also select the generations you want to delete. The example below
28741 deletes all the system generations that are more than two month old:
28744 guix system delete-generations 2m
28747 Running this command automatically reinstalls the bootloader with an updated
28748 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
28749 longer lists the generations that have been deleted.
28752 Build the derivation of the operating system, which includes all the
28753 configuration files and programs needed to boot and run the system.
28754 This action does not actually install anything.
28757 Populate the given directory with all the files necessary to run the
28758 operating system specified in @var{file}. This is useful for first-time
28759 installations of Guix System. For instance:
28762 guix system init my-os-config.scm /mnt
28765 copies to @file{/mnt} all the store items required by the configuration
28766 specified in @file{my-os-config.scm}. This includes configuration
28767 files, packages, and so on. It also creates other essential files
28768 needed for the system to operate correctly---e.g., the @file{/etc},
28769 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
28771 This command also installs bootloader on the target specified in
28772 @file{my-os-config}, unless the @option{--no-bootloader} option was
28776 @cindex virtual machine
28778 @anchor{guix system vm}
28779 Build a virtual machine that contains the operating system declared in
28780 @var{file}, and return a script to run that virtual machine (VM).
28783 The @code{vm} action and others below
28784 can use KVM support in the Linux-libre kernel. Specifically, if the
28785 machine has hardware virtualization support, the corresponding
28786 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
28787 must exist and be readable and writable by the user and by the
28788 build users of the daemon (@pxref{Build Environment Setup}).
28791 Arguments given to the script are passed to QEMU as in the example
28792 below, which enables networking and requests 1@tie{}GiB of RAM for the
28796 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
28799 The VM shares its store with the host system.
28801 Additional file systems can be shared between the host and the VM using
28802 the @option{--share} and @option{--expose} command-line options: the former
28803 specifies a directory to be shared with write access, while the latter
28804 provides read-only access to the shared directory.
28806 The example below creates a VM in which the user's home directory is
28807 accessible read-only, and where the @file{/exchange} directory is a
28808 read-write mapping of @file{$HOME/tmp} on the host:
28811 guix system vm my-config.scm \
28812 --expose=$HOME --share=$HOME/tmp=/exchange
28815 On GNU/Linux, the default is to boot directly to the kernel; this has
28816 the advantage of requiring only a very tiny root disk image since the
28817 store of the host can then be mounted.
28819 The @option{--full-boot} option forces a complete boot sequence, starting
28820 with the bootloader. This requires more disk space since a root image
28821 containing at least the kernel, initrd, and bootloader data files must
28822 be created. The @option{--image-size} option can be used to specify the
28825 @cindex System images, creation in various formats
28826 @cindex Creating system images in various formats
28829 @itemx docker-image
28830 Return a virtual machine, disk image, or Docker image of the operating
28831 system declared in @var{file} that stands alone. By default,
28832 @command{guix system} estimates the size of the image needed to store
28833 the system, but you can use the @option{--image-size} option to specify
28834 a value. Docker images are built to contain exactly what they need, so
28835 the @option{--image-size} option is ignored in the case of
28836 @code{docker-image}.
28838 You can specify the root file system type by using the
28839 @option{--file-system-type} option. It defaults to @code{ext4}. When its
28840 value is @code{iso9660}, the @option{--label} option can be used to specify
28841 a volume ID with @code{disk-image}.
28843 When using @code{vm-image}, the returned image is in qcow2 format, which
28844 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
28845 for more information on how to run the image in a virtual machine.
28847 When using @code{disk-image}, a raw disk image is produced; it can be
28848 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
28849 the device corresponding to a USB stick, one can copy the image to it
28850 using the following command:
28853 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc status=progress
28856 When using @code{docker-image}, a Docker image is produced. Guix builds
28857 the image from scratch, not from a pre-existing Docker base image. As a
28858 result, it contains @emph{exactly} what you define in the operating
28859 system configuration file. You can then load the image and launch a
28860 Docker container using commands like the following:
28863 image_id="`docker load < guix-system-docker-image.tar.gz`"
28864 container_id="`docker create $image_id`"
28865 docker start $container_id
28868 This command starts a new Docker container from the specified image. It
28869 will boot the Guix system in the usual manner, which means it will
28870 start any services you have defined in the operating system
28871 configuration. You can get an interactive shell running in the container
28872 using @command{docker exec}:
28875 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
28878 Depending on what you run in the Docker container, it
28879 may be necessary to give the container additional permissions. For
28880 example, if you intend to build software using Guix inside of the Docker
28881 container, you may need to pass the @option{--privileged} option to
28882 @code{docker create}.
28884 Last, the @option{--network} option applies to @command{guix system
28885 docker-image}: it produces an image where network is supposedly shared
28886 with the host, and thus without services like nscd or NetworkManager.
28889 Return a script to run the operating system declared in @var{file}
28890 within a container. Containers are a set of lightweight isolation
28891 mechanisms provided by the kernel Linux-libre. Containers are
28892 substantially less resource-demanding than full virtual machines since
28893 the kernel, shared objects, and other resources can be shared with the
28894 host system; this also means they provide thinner isolation.
28896 Currently, the script must be run as root in order to support more than
28897 a single user and group. The container shares its store with the host
28900 As with the @code{vm} action (@pxref{guix system vm}), additional file
28901 systems to be shared between the host and container can be specified
28902 using the @option{--share} and @option{--expose} options:
28905 guix system container my-config.scm \
28906 --expose=$HOME --share=$HOME/tmp=/exchange
28910 This option requires Linux-libre 3.19 or newer.
28915 @var{options} can contain any of the common build options (@pxref{Common
28916 Build Options}). In addition, @var{options} can contain one of the
28920 @item --expression=@var{expr}
28921 @itemx -e @var{expr}
28922 Consider the operating-system @var{expr} evaluates to.
28923 This is an alternative to specifying a file which evaluates to an
28925 This is used to generate the Guix system installer @pxref{Building the
28926 Installation Image}).
28928 @item --system=@var{system}
28929 @itemx -s @var{system}
28930 Attempt to build for @var{system} instead of the host system type.
28931 This works as per @command{guix build} (@pxref{Invoking guix build}).
28935 Return the derivation file name of the given operating system without
28938 @cindex provenance tracking, of the operating system
28939 @item --save-provenance
28940 As discussed above, @command{guix system init} and @command{guix system
28941 reconfigure} always save provenance information @i{via} a dedicated
28942 service (@pxref{Service Reference, @code{provenance-service-type}}).
28943 However, other commands don't do that by default. If you wish to, say,
28944 create a virtual machine image that contains provenance information, you
28948 guix system vm-image --save-provenance config.scm
28951 That way, the resulting image will effectively ``embed its own source''
28952 in the form of meta-data in @file{/run/current-system}. With that
28953 information, one can rebuild the image to make sure it really contains
28954 what it pretends to contain; or they could use that to derive a variant
28957 @item --file-system-type=@var{type}
28958 @itemx -t @var{type}
28959 For the @code{disk-image} action, create a file system of the given
28960 @var{type} on the image.
28962 When this option is omitted, @command{guix system} uses @code{ext4}.
28964 @cindex ISO-9660 format
28965 @cindex CD image format
28966 @cindex DVD image format
28967 @option{--file-system-type=iso9660} produces an ISO-9660 image, suitable
28968 for burning on CDs and DVDs.
28970 @item --image-size=@var{size}
28971 For the @code{vm-image} and @code{disk-image} actions, create an image
28972 of the given @var{size}. @var{size} may be a number of bytes, or it may
28973 include a unit as a suffix (@pxref{Block size, size specifications,,
28974 coreutils, GNU Coreutils}).
28976 When this option is omitted, @command{guix system} computes an estimate
28977 of the image size as a function of the size of the system declared in
28982 For the @code{container} action, allow containers to access the host network,
28983 that is, do not create a network namespace.
28985 @item --root=@var{file}
28986 @itemx -r @var{file}
28987 Make @var{file} a symlink to the result, and register it as a garbage
28990 @item --skip-checks
28991 Skip pre-installation safety checks.
28993 By default, @command{guix system init} and @command{guix system
28994 reconfigure} perform safety checks: they make sure the file systems that
28995 appear in the @code{operating-system} declaration actually exist
28996 (@pxref{File Systems}), and that any Linux kernel modules that may be
28997 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
28998 RAM Disk}). Passing this option skips these tests altogether.
29000 @item --allow-downgrades
29001 Instruct @command{guix system reconfigure} to allow system downgrades.
29003 By default, @command{reconfigure} prevents you from downgrading your
29004 system. It achieves that by comparing the provenance info of your
29005 system (shown by @command{guix system describe}) with that of your
29006 @command{guix} command (shown by @command{guix describe}). If the
29007 commits for @command{guix} are not descendants of those used for your
29008 system, @command{guix system reconfigure} errors out. Passing
29009 @option{--allow-downgrades} allows you to bypass these checks.
29012 Make sure you understand its security implications before using
29013 @option{--allow-downgrades}.
29017 @cindex on-error strategy
29018 @cindex error strategy
29019 @item --on-error=@var{strategy}
29020 Apply @var{strategy} when an error occurs when reading @var{file}.
29021 @var{strategy} may be one of the following:
29024 @item nothing-special
29025 Report the error concisely and exit. This is the default strategy.
29028 Likewise, but also display a backtrace.
29031 Report the error and enter Guile's debugger. From there, you can run
29032 commands such as @code{,bt} to get a backtrace, @code{,locals} to
29033 display local variable values, and more generally inspect the state of the
29034 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
29035 a list of available debugging commands.
29039 Once you have built, configured, re-configured, and re-re-configured
29040 your Guix installation, you may find it useful to list the operating
29041 system generations available on disk---and that you can choose from the
29042 bootloader boot menu:
29047 Describe the current system generation: its file name, the kernel and
29048 bootloader used, etc., as well as provenance information when available.
29050 @item list-generations
29051 List a summary of each generation of the operating system available on
29052 disk, in a human-readable way. This is similar to the
29053 @option{--list-generations} option of @command{guix package}
29054 (@pxref{Invoking guix package}).
29056 Optionally, one can specify a pattern, with the same syntax that is used
29057 in @command{guix package --list-generations}, to restrict the list of
29058 generations displayed. For instance, the following command displays
29059 generations that are up to 10 days old:
29062 $ guix system list-generations 10d
29067 The @command{guix system} command has even more to offer! The following
29068 sub-commands allow you to visualize how your system services relate to
29071 @anchor{system-extension-graph}
29074 @item extension-graph
29075 Emit in Dot/Graphviz format to standard output the @dfn{service
29076 extension graph} of the operating system defined in @var{file}
29077 (@pxref{Service Composition}, for more information on service
29083 $ guix system extension-graph @var{file} | xdot -
29086 shows the extension relations among services.
29088 @anchor{system-shepherd-graph}
29089 @item shepherd-graph
29090 Emit in Dot/Graphviz format to standard output the @dfn{dependency
29091 graph} of shepherd services of the operating system defined in
29092 @var{file}. @xref{Shepherd Services}, for more information and for an
29097 @node Invoking guix deploy
29098 @section Invoking @code{guix deploy}
29100 We've already seen @code{operating-system} declarations used to manage a
29101 machine's configuration locally. Suppose you need to configure multiple
29102 machines, though---perhaps you're managing a service on the web that's
29103 comprised of several servers. @command{guix deploy} enables you to use those
29104 same @code{operating-system} declarations to manage multiple remote hosts at
29105 once as a logical ``deployment''.
29108 The functionality described in this section is still under development
29109 and is subject to change. Get in touch with us on
29110 @email{guix-devel@@gnu.org}!
29114 guix deploy @var{file}
29117 Such an invocation will deploy the machines that the code within @var{file}
29118 evaluates to. As an example, @var{file} might contain a definition like this:
29121 ;; This is a Guix deployment of a "bare bones" setup, with
29122 ;; no X11 display server, to a machine with an SSH daemon
29123 ;; listening on localhost:2222. A configuration such as this
29124 ;; may be appropriate for virtual machine with ports
29125 ;; forwarded to the host's loopback interface.
29127 (use-service-modules networking ssh)
29128 (use-package-modules bootloaders)
29132 (host-name "gnu-deployed")
29133 (timezone "Etc/UTC")
29134 (bootloader (bootloader-configuration
29135 (bootloader grub-bootloader)
29136 (target "/dev/vda")
29137 (terminal-outputs '(console))))
29138 (file-systems (cons (file-system
29140 (device "/dev/vda1")
29142 %base-file-systems))
29144 (append (list (service dhcp-client-service-type)
29145 (service openssh-service-type
29146 (openssh-configuration
29147 (permit-root-login #t)
29148 (allow-empty-passwords? #t))))
29152 (operating-system %system)
29153 (environment managed-host-environment-type)
29154 (configuration (machine-ssh-configuration
29155 (host-name "localhost")
29156 (system "x86_64-linux")
29158 (identity "./id_rsa")
29162 The file should evaluate to a list of @var{machine} objects. This example,
29163 upon being deployed, will create a new generation on the remote system
29164 realizing the @code{operating-system} declaration @code{%system}.
29165 @code{environment} and @code{configuration} specify how the machine should be
29166 provisioned---that is, how the computing resources should be created and
29167 managed. The above example does not create any resources, as a
29168 @code{'managed-host} is a machine that is already running the Guix system and
29169 available over the network. This is a particularly simple case; a more
29170 complex deployment may involve, for example, starting virtual machines through
29171 a Virtual Private Server (VPS) provider. In such a case, a different
29172 @var{environment} type would be used.
29174 Do note that you first need to generate a key pair on the coordinator machine
29175 to allow the daemon to export signed archives of files from the store
29176 (@pxref{Invoking guix archive}).
29179 # guix archive --generate-key
29183 Each target machine must authorize the key of the master machine so that it
29184 accepts store items it receives from the coordinator:
29187 # guix archive --authorize < coordinator-public-key.txt
29190 @code{user}, in this example, specifies the name of the user account to log in
29191 as to perform the deployment. Its default value is @code{root}, but root
29192 login over SSH may be forbidden in some cases. To work around this,
29193 @command{guix deploy} can log in as an unprivileged user and employ
29194 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
29195 currently installed on the remote and can be invoked non-interactively as
29196 @code{user}. That is, the line in @code{sudoers} granting @code{user} the
29197 ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
29198 be accomplished with the following operating system configuration snippet:
29202 (gnu system)) ;for %sudoers-specification
29204 (define %user "username")
29209 (plain-file "sudoers"
29210 (string-append (plain-file-content %sudoers-specification)
29211 (format #f "~a ALL = NOPASSWD: ALL~%"
29216 For more information regarding the format of the @file{sudoers} file,
29217 consult @command{man sudoers}.
29219 @deftp {Data Type} machine
29220 This is the data type representing a single machine in a heterogeneous Guix
29224 @item @code{operating-system}
29225 The object of the operating system configuration to deploy.
29227 @item @code{environment}
29228 An @code{environment-type} describing how the machine should be provisioned.
29230 @item @code{configuration} (default: @code{#f})
29231 An object describing the configuration for the machine's @code{environment}.
29232 If the @code{environment} has a default configuration, @code{#f} may be used.
29233 If @code{#f} is used for an environment with no default configuration,
29234 however, an error will be thrown.
29238 @deftp {Data Type} machine-ssh-configuration
29239 This is the data type representing the SSH client parameters for a machine
29240 with an @code{environment} of @code{managed-host-environment-type}.
29243 @item @code{host-name}
29244 @item @code{build-locally?} (default: @code{#t})
29245 If false, system derivations will be built on the machine being deployed to.
29246 @item @code{system}
29247 The system type describing the architecture of the machine being deployed
29248 to---e.g., @code{"x86_64-linux"}.
29249 @item @code{authorize?} (default: @code{#t})
29250 If true, the coordinator's signing key will be added to the remote's ACL
29252 @item @code{port} (default: @code{22})
29253 @item @code{user} (default: @code{"root"})
29254 @item @code{identity} (default: @code{#f})
29255 If specified, the path to the SSH private key to use to authenticate with the
29258 @item @code{host-key} (default: @code{#f})
29259 This should be the SSH host key of the machine, which looks like this:
29262 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
29265 When @code{host-key} is @code{#f}, the server is authenticated against
29266 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
29269 @item @code{allow-downgrades?} (default: @code{#f})
29270 Whether to allow potential downgrades.
29272 Like @command{guix system reconfigure}, @command{guix deploy} compares
29273 the channel commits currently deployed on the remote host (as returned
29274 by @command{guix system describe}) to those currently in use (as
29275 returned by @command{guix describe}) to determine whether commits
29276 currently in use are descendants of those deployed. When this is not
29277 the case and @code{allow-downgrades?} is false, it raises an error.
29278 This ensures you do not accidentally downgrade remote machines.
29282 @deftp {Data Type} digital-ocean-configuration
29283 This is the data type describing the Droplet that should be created for a
29284 machine with an @code{environment} of @code{digital-ocean-environment-type}.
29287 @item @code{ssh-key}
29288 The path to the SSH private key to use to authenticate with the remote
29289 host. In the future, this field may not exist.
29291 A list of string ``tags'' that uniquely identify the machine. Must be given
29292 such that no two machines in the deployment have the same set of tags.
29293 @item @code{region}
29294 A Digital Ocean region slug, such as @code{"nyc3"}.
29296 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
29297 @item @code{enable-ipv6?}
29298 Whether or not the droplet should be created with IPv6 networking.
29302 @node Running Guix in a VM
29303 @section Running Guix in a Virtual Machine
29305 @cindex virtual machine
29306 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
29308 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
29309 This image is a compressed image in QCOW format. You will first need to
29310 decompress with @command{xz -d}, and then you can pass it to an emulator such
29311 as QEMU (see below for details).
29313 This image boots the Xfce graphical environment and it contains some
29314 commonly-used tools. You can install more software in the image by running
29315 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
29316 also reconfigure the system based on its initial configuration file available
29317 as @file{/run/current-system/configuration.scm} (@pxref{Using the
29318 Configuration System}).
29320 Instead of using this pre-built image, one can also build their own virtual
29321 machine image using @command{guix system vm-image} (@pxref{Invoking guix
29322 system}). The returned image is in qcow2 format, which the
29323 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
29326 If you built your own image, you must copy it out of the store
29327 (@pxref{The Store}) and give yourself permission to write to the copy
29328 before you can use it. When invoking QEMU, you must choose a system
29329 emulator that is suitable for your hardware platform. Here is a minimal
29330 QEMU invocation that will boot the result of @command{guix system
29331 vm-image} on x86_64 hardware:
29334 $ qemu-system-x86_64 \
29335 -nic user,model=virtio-net-pci \
29336 -enable-kvm -m 1024 \
29337 -device virtio-blk,drive=myhd \
29338 -drive if=none,file=/tmp/qemu-image,id=myhd
29341 Here is what each of these options means:
29344 @item qemu-system-x86_64
29345 This specifies the hardware platform to emulate. This should match the
29348 @item -nic user,model=virtio-net-pci
29349 Enable the unprivileged user-mode network stack. The guest OS can
29350 access the host but not vice versa. This is the simplest way to get the
29351 guest OS online. @code{model} specifies which network device to emulate:
29352 @code{virtio-net-pci} is a special device made for virtualized operating
29353 systems and recommended for most uses. Assuming your hardware platform is
29354 x86_64, you can get a list of available NIC models by running
29355 @command{qemu-system-x86_64 -nic model=help}.
29358 If your system has hardware virtualization extensions, enabling the
29359 virtual machine support (KVM) of the Linux kernel will make things run
29362 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
29364 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
29365 which may be insufficient for some operations.
29367 @item -device virtio-blk,drive=myhd
29368 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
29369 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
29370 better performance than if it were emulating a complete disk drive. See the
29371 QEMU and KVM documentation for more info.
29373 @item -drive if=none,file=/tmp/qemu-image,id=myhd
29374 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
29375 the ``myhd'' drive.
29378 The default @command{run-vm.sh} script that is returned by an invocation of
29379 @command{guix system vm} does not add a @command{-nic user} flag by default.
29380 To get network access from within the vm add the @code{(dhcp-client-service)}
29381 to your system definition and start the VM using
29382 @command{`guix system vm config.scm` -nic user}. An important caveat of using
29383 @command{-nic user} for networking is that @command{ping} will not work, because
29384 it uses the ICMP protocol. You'll have to use a different command to check for
29385 network connectivity, for example @command{guix download}.
29387 @subsection Connecting Through SSH
29391 To enable SSH inside a VM you need to add an SSH server like
29392 @code{openssh-service-type} to your VM (@pxref{Networking Services,
29393 @code{openssh-service-type}}). In addition you need to forward the SSH port,
29394 22 by default, to the host. You can do this with
29397 `guix system vm config.scm` -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
29400 To connect to the VM you can run
29403 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
29406 The @command{-p} tells @command{ssh} the port you want to connect to.
29407 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
29408 every time you modify your @command{config.scm} file and the
29409 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
29410 connection to an unknown host every time you connect.
29412 @subsection Using @command{virt-viewer} with Spice
29414 As an alternative to the default @command{qemu} graphical client you can
29415 use the @command{remote-viewer} from the @command{virt-viewer} package. To
29416 connect pass the @command{-spice port=5930,disable-ticketing} flag to
29417 @command{qemu}. See previous section for further information on how to do this.
29419 Spice also allows you to do some nice stuff like share your clipboard with your
29420 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
29423 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
29424 -chardev spicevmc,name=vdagent,id=vdagent
29425 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
29426 name=com.redhat.spice.0
29429 You'll also need to add the @code{(spice-vdagent-service)} to your
29430 system definition (@pxref{Miscellaneous Services, Spice service}).
29432 @node Defining Services
29433 @section Defining Services
29435 The previous sections show the available services and how one can combine
29436 them in an @code{operating-system} declaration. But how do we define
29437 them in the first place? And what is a service anyway?
29440 * Service Composition:: The model for composing services.
29441 * Service Types and Services:: Types and services.
29442 * Service Reference:: API reference.
29443 * Shepherd Services:: A particular type of service.
29446 @node Service Composition
29447 @subsection Service Composition
29451 Here we define a @dfn{service} as, broadly, something that extends the
29452 functionality of the operating system. Often a service is a process---a
29453 @dfn{daemon}---started when the system boots: a secure shell server, a
29454 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
29455 whose execution can be triggered by another daemon---e.g., an FTP server
29456 started by @command{inetd} or a D-Bus service activated by
29457 @command{dbus-daemon}. Occasionally, a service does not map to a
29458 daemon. For instance, the ``account'' service collects user accounts
29459 and makes sure they exist when the system runs; the ``udev'' service
29460 collects device management rules and makes them available to the eudev
29461 daemon; the @file{/etc} service populates the @file{/etc} directory
29464 @cindex service extensions
29465 Guix system services are connected by @dfn{extensions}. For instance, the
29466 secure shell service @emph{extends} the Shepherd---the
29467 initialization system, running as PID@tie{}1---by giving it the command
29468 lines to start and stop the secure shell daemon (@pxref{Networking
29469 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
29470 service by passing it its @file{.service} specification, and extends the
29471 udev service by passing it device management rules (@pxref{Desktop
29472 Services, @code{upower-service}}); the Guix daemon service extends the
29473 Shepherd by passing it the command lines to start and stop the daemon,
29474 and extends the account service by passing it a list of required build
29475 user accounts (@pxref{Base Services}).
29477 All in all, services and their ``extends'' relations form a directed
29478 acyclic graph (DAG). If we represent services as boxes and extensions
29479 as arrows, a typical system might provide something like this:
29481 @image{images/service-graph,,5in,Typical service extension graph.}
29483 @cindex system service
29484 At the bottom, we see the @dfn{system service}, which produces the
29485 directory containing everything to run and boot the system, as returned
29486 by the @command{guix system build} command. @xref{Service Reference},
29487 to learn about the other service types shown here.
29488 @xref{system-extension-graph, the @command{guix system extension-graph}
29489 command}, for information on how to generate this representation for a
29490 particular operating system definition.
29492 @cindex service types
29493 Technically, developers can define @dfn{service types} to express these
29494 relations. There can be any number of services of a given type on the
29495 system---for instance, a system running two instances of the GNU secure
29496 shell server (lsh) has two instances of @code{lsh-service-type}, with
29497 different parameters.
29499 The following section describes the programming interface for service
29500 types and services.
29502 @node Service Types and Services
29503 @subsection Service Types and Services
29505 A @dfn{service type} is a node in the DAG described above. Let us start
29506 with a simple example, the service type for the Guix build daemon
29507 (@pxref{Invoking guix-daemon}):
29510 (define guix-service-type
29514 (list (service-extension shepherd-root-service-type guix-shepherd-service)
29515 (service-extension account-service-type guix-accounts)
29516 (service-extension activation-service-type guix-activation)))
29517 (default-value (guix-configuration))))
29521 It defines three things:
29525 A name, whose sole purpose is to make inspection and debugging easier.
29528 A list of @dfn{service extensions}, where each extension designates the
29529 target service type and a procedure that, given the parameters of the
29530 service, returns a list of objects to extend the service of that type.
29532 Every service type has at least one service extension. The only
29533 exception is the @dfn{boot service type}, which is the ultimate service.
29536 Optionally, a default value for instances of this type.
29539 In this example, @code{guix-service-type} extends three services:
29542 @item shepherd-root-service-type
29543 The @code{guix-shepherd-service} procedure defines how the Shepherd
29544 service is extended. Namely, it returns a @code{<shepherd-service>}
29545 object that defines how @command{guix-daemon} is started and stopped
29546 (@pxref{Shepherd Services}).
29548 @item account-service-type
29549 This extension for this service is computed by @code{guix-accounts},
29550 which returns a list of @code{user-group} and @code{user-account}
29551 objects representing the build user accounts (@pxref{Invoking
29554 @item activation-service-type
29555 Here @code{guix-activation} is a procedure that returns a gexp, which is
29556 a code snippet to run at ``activation time''---e.g., when the service is
29560 A service of this type is instantiated like this:
29563 (service guix-service-type
29564 (guix-configuration
29566 (use-substitutes? #f)))
29569 The second argument to the @code{service} form is a value representing
29570 the parameters of this specific service instance.
29571 @xref{guix-configuration-type, @code{guix-configuration}}, for
29572 information about the @code{guix-configuration} data type. When the
29573 value is omitted, the default value specified by
29574 @code{guix-service-type} is used:
29577 (service guix-service-type)
29580 @code{guix-service-type} is quite simple because it extends other
29581 services but is not extensible itself.
29583 @c @subsubsubsection Extensible Service Types
29585 The service type for an @emph{extensible} service looks like this:
29588 (define udev-service-type
29589 (service-type (name 'udev)
29591 (list (service-extension shepherd-root-service-type
29592 udev-shepherd-service)))
29594 (compose concatenate) ;concatenate the list of rules
29595 (extend (lambda (config rules)
29597 (($ <udev-configuration> udev initial-rules)
29598 (udev-configuration
29599 (udev udev) ;the udev package to use
29600 (rules (append initial-rules rules)))))))))
29603 This is the service type for the
29604 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
29605 management daemon}. Compared to the previous example, in addition to an
29606 extension of @code{shepherd-root-service-type}, we see two new fields:
29610 This is the procedure to @dfn{compose} the list of extensions to
29611 services of this type.
29613 Services can extend the udev service by passing it lists of rules; we
29614 compose those extensions simply by concatenating them.
29617 This procedure defines how the value of the service is @dfn{extended} with
29618 the composition of the extensions.
29620 Udev extensions are composed into a list of rules, but the udev service
29621 value is itself a @code{<udev-configuration>} record. So here, we
29622 extend that record by appending the list of rules it contains to the
29623 list of contributed rules.
29626 This is a string giving an overview of the service type. The string can
29627 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
29628 @command{guix system search} command searches these strings and displays
29629 them (@pxref{Invoking guix system}).
29632 There can be only one instance of an extensible service type such as
29633 @code{udev-service-type}. If there were more, the
29634 @code{service-extension} specifications would be ambiguous.
29636 Still here? The next section provides a reference of the programming
29637 interface for services.
29639 @node Service Reference
29640 @subsection Service Reference
29642 We have seen an overview of service types (@pxref{Service Types and
29643 Services}). This section provides a reference on how to manipulate
29644 services and service types. This interface is provided by the
29645 @code{(gnu services)} module.
29647 @deffn {Scheme Procedure} service @var{type} [@var{value}]
29648 Return a new service of @var{type}, a @code{<service-type>} object (see
29649 below). @var{value} can be any object; it represents the parameters of
29650 this particular service instance.
29652 When @var{value} is omitted, the default value specified by @var{type}
29653 is used; if @var{type} does not specify a default value, an error is
29656 For instance, this:
29659 (service openssh-service-type)
29663 is equivalent to this:
29666 (service openssh-service-type
29667 (openssh-configuration))
29670 In both cases the result is an instance of @code{openssh-service-type}
29671 with the default configuration.
29674 @deffn {Scheme Procedure} service? @var{obj}
29675 Return true if @var{obj} is a service.
29678 @deffn {Scheme Procedure} service-kind @var{service}
29679 Return the type of @var{service}---i.e., a @code{<service-type>} object.
29682 @deffn {Scheme Procedure} service-value @var{service}
29683 Return the value associated with @var{service}. It represents its
29687 Here is an example of how a service is created and manipulated:
29691 (service nginx-service-type
29692 (nginx-configuration
29694 (log-directory log-directory)
29695 (run-directory run-directory)
29696 (file config-file))))
29701 (eq? (service-kind s) nginx-service-type)
29705 The @code{modify-services} form provides a handy way to change the
29706 parameters of some of the services of a list such as
29707 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
29708 evaluates to a list of services. Of course, you could always use
29709 standard list combinators such as @code{map} and @code{fold} to do that
29710 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
29711 @code{modify-services} simply provides a more concise form for this
29714 @deffn {Scheme Syntax} modify-services @var{services} @
29715 (@var{type} @var{variable} => @var{body}) @dots{}
29717 Modify the services listed in @var{services} according to the given
29718 clauses. Each clause has the form:
29721 (@var{type} @var{variable} => @var{body})
29724 where @var{type} is a service type---e.g.,
29725 @code{guix-service-type}---and @var{variable} is an identifier that is
29726 bound within the @var{body} to the service parameters---e.g., a
29727 @code{guix-configuration} instance---of the original service of that
29730 The @var{body} should evaluate to the new service parameters, which will
29731 be used to configure the new service. This new service will replace the
29732 original in the resulting list. Because a service's service parameters
29733 are created using @code{define-record-type*}, you can write a succinct
29734 @var{body} that evaluates to the new service parameters by using the
29735 @code{inherit} feature that @code{define-record-type*} provides.
29737 @xref{Using the Configuration System}, for example usage.
29741 Next comes the programming interface for service types. This is
29742 something you want to know when writing new service definitions, but not
29743 necessarily when simply looking for ways to customize your
29744 @code{operating-system} declaration.
29746 @deftp {Data Type} service-type
29747 @cindex service type
29748 This is the representation of a @dfn{service type} (@pxref{Service Types
29753 This is a symbol, used only to simplify inspection and debugging.
29755 @item @code{extensions}
29756 A non-empty list of @code{<service-extension>} objects (see below).
29758 @item @code{compose} (default: @code{#f})
29759 If this is @code{#f}, then the service type denotes services that cannot
29760 be extended---i.e., services that do not receive ``values'' from other
29763 Otherwise, it must be a one-argument procedure. The procedure is called
29764 by @code{fold-services} and is passed a list of values collected from
29765 extensions. It may return any single value.
29767 @item @code{extend} (default: @code{#f})
29768 If this is @code{#f}, services of this type cannot be extended.
29770 Otherwise, it must be a two-argument procedure: @code{fold-services}
29771 calls it, passing it the initial value of the service as the first
29772 argument and the result of applying @code{compose} to the extension
29773 values as the second argument. It must return a value that is a valid
29774 parameter value for the service instance.
29776 @item @code{description}
29777 This is a string, possibly using Texinfo markup, describing in a couple
29778 of sentences what the service is about. This string allows users to
29779 find about the service through @command{guix system search}
29780 (@pxref{Invoking guix system}).
29782 @item @code{default-value} (default: @code{&no-default-value})
29783 The default value associated for instances of this service type. This
29784 allows users to use the @code{service} form without its second argument:
29787 (service @var{type})
29790 The returned service in this case has the default value specified by
29794 @xref{Service Types and Services}, for examples.
29797 @deffn {Scheme Procedure} service-extension @var{target-type} @
29799 Return a new extension for services of type @var{target-type}.
29800 @var{compute} must be a one-argument procedure: @code{fold-services}
29801 calls it, passing it the value associated with the service that provides
29802 the extension; it must return a valid value for the target service.
29805 @deffn {Scheme Procedure} service-extension? @var{obj}
29806 Return true if @var{obj} is a service extension.
29809 Occasionally, you might want to simply extend an existing service. This
29810 involves creating a new service type and specifying the extension of
29811 interest, which can be verbose; the @code{simple-service} procedure
29812 provides a shorthand for this.
29814 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
29815 Return a service that extends @var{target} with @var{value}. This works
29816 by creating a singleton service type @var{name}, of which the returned
29817 service is an instance.
29819 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
29823 (simple-service 'my-mcron-job mcron-service-type
29824 #~(job '(next-hour (3)) "guix gc -F 2G"))
29828 At the core of the service abstraction lies the @code{fold-services}
29829 procedure, which is responsible for ``compiling'' a list of services
29830 down to a single directory that contains everything needed to boot and
29831 run the system---the directory shown by the @command{guix system build}
29832 command (@pxref{Invoking guix system}). In essence, it propagates
29833 service extensions down the service graph, updating each node parameters
29834 on the way, until it reaches the root node.
29836 @deffn {Scheme Procedure} fold-services @var{services} @
29837 [#:target-type @var{system-service-type}]
29838 Fold @var{services} by propagating their extensions down to the root of
29839 type @var{target-type}; return the root service adjusted accordingly.
29842 Lastly, the @code{(gnu services)} module also defines several essential
29843 service types, some of which are listed below.
29845 @defvr {Scheme Variable} system-service-type
29846 This is the root of the service graph. It produces the system directory
29847 as returned by the @command{guix system build} command.
29850 @defvr {Scheme Variable} boot-service-type
29851 The type of the ``boot service'', which produces the @dfn{boot script}.
29852 The boot script is what the initial RAM disk runs when booting.
29855 @defvr {Scheme Variable} etc-service-type
29856 The type of the @file{/etc} service. This service is used to create
29857 files under @file{/etc} and can be extended by
29858 passing it name/file tuples such as:
29861 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
29864 In this example, the effect would be to add an @file{/etc/issue} file
29865 pointing to the given file.
29868 @defvr {Scheme Variable} setuid-program-service-type
29869 Type for the ``setuid-program service''. This service collects lists of
29870 executable file names, passed as gexps, and adds them to the set of
29871 setuid-root programs on the system (@pxref{Setuid Programs}).
29874 @defvr {Scheme Variable} profile-service-type
29875 Type of the service that populates the @dfn{system profile}---i.e., the
29876 programs under @file{/run/current-system/profile}. Other services can
29877 extend it by passing it lists of packages to add to the system profile.
29880 @cindex provenance tracking, of the operating system
29881 @anchor{provenance-service-type}
29882 @defvr {Scheme Variable} provenance-service-type
29883 This is the type of the service that records @dfn{provenance meta-data}
29884 in the system itself. It creates several files under
29885 @file{/run/current-system}:
29889 This is a ``channel file'' that can be passed to @command{guix pull -C}
29890 or @command{guix time-machine -C}, and which describes the channels used
29891 to build the system, if that information was available
29892 (@pxref{Channels}).
29894 @item configuration.scm
29895 This is the file that was passed as the value for this
29896 @code{provenance-service-type} service. By default, @command{guix
29897 system reconfigure} automatically passes the OS configuration file it
29898 received on the command line.
29901 This contains the same information as the two other files but in a
29902 format that is more readily processable.
29905 In general, these two pieces of information (channels and configuration
29906 file) are enough to reproduce the operating system ``from source''.
29909 This information is necessary to rebuild your operating system, but it
29910 is not always sufficient. In particular, @file{configuration.scm}
29911 itself is insufficient if it is not self-contained---if it refers to
29912 external Guile modules or to extra files. If you want
29913 @file{configuration.scm} to be self-contained, we recommend that modules
29914 or files it refers to be part of a channel.
29916 Besides, provenance meta-data is ``silent'' in the sense that it does
29917 not change the bits contained in your system, @emph{except for the
29918 meta-data bits themselves}. Two different OS configurations or sets of
29919 channels can lead to the same system, bit-for-bit; when
29920 @code{provenance-service-type} is used, these two systems will have
29921 different meta-data and thus different store file names, which makes
29922 comparison less trivial.
29925 This service is automatically added to your operating system
29926 configuration when you use @command{guix system reconfigure},
29927 @command{guix system init}, or @command{guix deploy}.
29930 @node Shepherd Services
29931 @subsection Shepherd Services
29933 @cindex shepherd services
29935 @cindex init system
29936 The @code{(gnu services shepherd)} module provides a way to define
29937 services managed by the GNU@tie{}Shepherd, which is the
29938 initialization system---the first process that is started when the
29939 system boots, also known as PID@tie{}1
29940 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
29942 Services in the Shepherd can depend on each other. For instance, the
29943 SSH daemon may need to be started after the syslog daemon has been
29944 started, which in turn can only happen once all the file systems have
29945 been mounted. The simple operating system defined earlier (@pxref{Using
29946 the Configuration System}) results in a service graph like this:
29948 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
29950 You can actually generate such a graph for any operating system
29951 definition using the @command{guix system shepherd-graph} command
29952 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
29954 The @code{%shepherd-root-service} is a service object representing
29955 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
29956 by passing it lists of @code{<shepherd-service>} objects.
29958 @deftp {Data Type} shepherd-service
29959 The data type representing a service managed by the Shepherd.
29962 @item @code{provision}
29963 This is a list of symbols denoting what the service provides.
29965 These are the names that may be passed to @command{herd start},
29966 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
29967 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
29968 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
29970 @item @code{requirement} (default: @code{'()})
29971 List of symbols denoting the Shepherd services this one depends on.
29973 @cindex one-shot services, for the Shepherd
29974 @item @code{one-shot?} (default: @code{#f})
29975 Whether this service is @dfn{one-shot}. One-shot services stop immediately
29976 after their @code{start} action has completed. @xref{Slots of services,,,
29977 shepherd, The GNU Shepherd Manual}, for more info.
29979 @item @code{respawn?} (default: @code{#t})
29980 Whether to restart the service when it stops, for instance when the
29981 underlying process dies.
29984 @itemx @code{stop} (default: @code{#~(const #f)})
29985 The @code{start} and @code{stop} fields refer to the Shepherd's
29986 facilities to start and stop processes (@pxref{Service De- and
29987 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
29988 G-expressions that get expanded in the Shepherd configuration file
29989 (@pxref{G-Expressions}).
29991 @item @code{actions} (default: @code{'()})
29992 @cindex actions, of Shepherd services
29993 This is a list of @code{shepherd-action} objects (see below) defining
29994 @dfn{actions} supported by the service, in addition to the standard
29995 @code{start} and @code{stop} actions. Actions listed here become available as
29996 @command{herd} sub-commands:
29999 herd @var{action} @var{service} [@var{arguments}@dots{}]
30002 @item @code{auto-start?} (default: @code{#t})
30003 Whether this service should be started automatically by the Shepherd. If it
30004 is @code{#f} the service has to be started manually with @code{herd start}.
30006 @item @code{documentation}
30007 A documentation string, as shown when running:
30010 herd doc @var{service-name}
30013 where @var{service-name} is one of the symbols in @code{provision}
30014 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
30016 @item @code{modules} (default: @code{%default-modules})
30017 This is the list of modules that must be in scope when @code{start} and
30018 @code{stop} are evaluated.
30023 @deftp {Data Type} shepherd-action
30024 This is the data type that defines additional actions implemented by a
30025 Shepherd service (see above).
30029 Symbol naming the action.
30031 @item documentation
30032 This is a documentation string for the action. It can be viewed by running:
30035 herd doc @var{service} action @var{action}
30039 This should be a gexp that evaluates to a procedure of at least one argument,
30040 which is the ``running value'' of the service (@pxref{Slots of services,,,
30041 shepherd, The GNU Shepherd Manual}).
30044 The following example defines an action called @code{say-hello} that kindly
30050 (documentation "Say hi!")
30051 (procedure #~(lambda (running . args)
30052 (format #t "Hello, friend! arguments: ~s\n"
30057 Assuming this action is added to the @code{example} service, then you can do:
30060 # herd say-hello example
30061 Hello, friend! arguments: ()
30062 # herd say-hello example a b c
30063 Hello, friend! arguments: ("a" "b" "c")
30066 This, as you can see, is a fairly sophisticated way to say hello.
30067 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
30071 @defvr {Scheme Variable} shepherd-root-service-type
30072 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
30074 This is the service type that extensions target when they want to create
30075 shepherd services (@pxref{Service Types and Services}, for an example).
30076 Each extension must pass a list of @code{<shepherd-service>}.
30079 @defvr {Scheme Variable} %shepherd-root-service
30080 This service represents PID@tie{}1.
30084 @node Documentation
30085 @chapter Documentation
30087 @cindex documentation, searching for
30088 @cindex searching for documentation
30089 @cindex Info, documentation format
30091 @cindex manual pages
30092 In most cases packages installed with Guix come with documentation.
30093 There are two main documentation formats: ``Info'', a browseable
30094 hypertext format used for GNU software, and ``manual pages'' (or ``man
30095 pages''), the linear documentation format traditionally found on Unix.
30096 Info manuals are accessed with the @command{info} command or with Emacs,
30097 and man pages are accessed using @command{man}.
30099 You can look for documentation of software installed on your system by
30100 keyword. For example, the following command searches for information
30101 about ``TLS'' in Info manuals:
30105 "(emacs)Network Security" -- STARTTLS
30106 "(emacs)Network Security" -- TLS
30107 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
30108 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
30113 The command below searches for the same keyword in man pages:
30117 SSL (7) - OpenSSL SSL/TLS library
30118 certtool (1) - GnuTLS certificate tool
30122 These searches are purely local to your computer so you have the
30123 guarantee that documentation you find corresponds to what you have
30124 actually installed, you can access it off-line, and your privacy is
30127 Once you have these results, you can view the relevant documentation by
30131 $ info "(gnutls)Core TLS API"
30141 Info manuals contain sections and indices as well as hyperlinks like
30142 those found in Web pages. The @command{info} reader (@pxref{Top, Info
30143 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
30144 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
30145 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
30146 Introduction}, for an introduction to Info navigation.
30148 @node Installing Debugging Files
30149 @chapter Installing Debugging Files
30151 @cindex debugging files
30152 Program binaries, as produced by the GCC compilers for instance, are
30153 typically written in the ELF format, with a section containing
30154 @dfn{debugging information}. Debugging information is what allows the
30155 debugger, GDB, to map binary code to source code; it is required to
30156 debug a compiled program in good conditions.
30158 The problem with debugging information is that is takes up a fair amount
30159 of disk space. For example, debugging information for the GNU C Library
30160 weighs in at more than 60 MiB. Thus, as a user, keeping all the
30161 debugging info of all the installed programs is usually not an option.
30162 Yet, space savings should not come at the cost of an impediment to
30163 debugging---especially in the GNU system, which should make it easier
30164 for users to exert their computing freedom (@pxref{GNU Distribution}).
30166 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
30167 mechanism that allows users to get the best of both worlds: debugging
30168 information can be stripped from the binaries and stored in separate
30169 files. GDB is then able to load debugging information from those files,
30170 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
30173 The GNU distribution takes advantage of this by storing debugging
30174 information in the @code{lib/debug} sub-directory of a separate package
30175 output unimaginatively called @code{debug} (@pxref{Packages with
30176 Multiple Outputs}). Users can choose to install the @code{debug} output
30177 of a package when they need it. For instance, the following command
30178 installs the debugging information for the GNU C Library and for GNU
30182 guix install glibc:debug guile:debug
30185 GDB must then be told to look for debug files in the user's profile, by
30186 setting the @code{debug-file-directory} variable (consider setting it
30187 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
30191 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
30194 From there on, GDB will pick up debugging information from the
30195 @file{.debug} files under @file{~/.guix-profile/lib/debug}.
30197 In addition, you will most likely want GDB to be able to show the source
30198 code being debugged. To do that, you will have to unpack the source
30199 code of the package of interest (obtained with @code{guix build
30200 --source}, @pxref{Invoking guix build}), and to point GDB to that source
30201 directory using the @code{directory} command (@pxref{Source Path,
30202 @code{directory},, gdb, Debugging with GDB}).
30204 @c XXX: keep me up-to-date
30205 The @code{debug} output mechanism in Guix is implemented by the
30206 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
30207 opt-in---debugging information is available only for the packages
30208 with definitions explicitly declaring a @code{debug} output. This may be
30209 changed to opt-out in the future if our build farm servers can handle
30210 the load. To check whether a package has a @code{debug} output, use
30211 @command{guix package --list-available} (@pxref{Invoking guix package}).
30214 @node Security Updates
30215 @chapter Security Updates
30217 @cindex security updates
30218 @cindex security vulnerabilities
30219 Occasionally, important security vulnerabilities are discovered in software
30220 packages and must be patched. Guix developers try hard to keep track of
30221 known vulnerabilities and to apply fixes as soon as possible in the
30222 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
30223 containing only security updates). The @command{guix lint} tool helps
30224 developers find out about vulnerable versions of software packages in the
30229 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
30230 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
30231 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
30235 @xref{Invoking guix lint}, for more information.
30237 Guix follows a functional
30238 package management discipline (@pxref{Introduction}), which implies
30239 that, when a package is changed, @emph{every package that depends on it}
30240 must be rebuilt. This can significantly slow down the deployment of
30241 fixes in core packages such as libc or Bash, since basically the whole
30242 distribution would need to be rebuilt. Using pre-built binaries helps
30243 (@pxref{Substitutes}), but deployment may still take more time than
30247 To address this, Guix implements @dfn{grafts}, a mechanism that allows
30248 for fast deployment of critical updates without the costs associated
30249 with a whole-distribution rebuild. The idea is to rebuild only the
30250 package that needs to be patched, and then to ``graft'' it onto packages
30251 explicitly installed by the user and that were previously referring to
30252 the original package. The cost of grafting is typically very low, and
30253 order of magnitudes lower than a full rebuild of the dependency chain.
30255 @cindex replacements of packages, for grafts
30256 For instance, suppose a security update needs to be applied to Bash.
30257 Guix developers will provide a package definition for the ``fixed''
30258 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
30259 Packages}). Then, the original package definition is augmented with a
30260 @code{replacement} field pointing to the package containing the bug fix:
30267 (replacement bash-fixed)))
30270 From there on, any package depending directly or indirectly on Bash---as
30271 reported by @command{guix gc --requisites} (@pxref{Invoking guix
30272 gc})---that is installed is automatically ``rewritten'' to refer to
30273 @code{bash-fixed} instead of @code{bash}. This grafting process takes
30274 time proportional to the size of the package, usually less than a
30275 minute for an ``average'' package on a recent machine. Grafting is
30276 recursive: when an indirect dependency requires grafting, then grafting
30277 ``propagates'' up to the package that the user is installing.
30279 Currently, the length of the name and version of the graft and that of
30280 the package it replaces (@code{bash-fixed} and @code{bash} in the example
30281 above) must be equal. This restriction mostly comes from the fact that
30282 grafting works by patching files, including binary files, directly.
30283 Other restrictions may apply: for instance, when adding a graft to a
30284 package providing a shared library, the original shared library and its
30285 replacement must have the same @code{SONAME} and be binary-compatible.
30287 The @option{--no-grafts} command-line option allows you to forcefully
30288 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
30292 guix build bash --no-grafts
30296 returns the store file name of the original Bash, whereas:
30303 returns the store file name of the ``fixed'', replacement Bash. This
30304 allows you to distinguish between the two variants of Bash.
30306 To verify which Bash your whole profile refers to, you can run
30307 (@pxref{Invoking guix gc}):
30310 guix gc -R `readlink -f ~/.guix-profile` | grep bash
30314 @dots{} and compare the store file names that you get with those above.
30315 Likewise for a complete Guix system generation:
30318 guix gc -R `guix system build my-config.scm` | grep bash
30321 Lastly, to check which Bash running processes are using, you can use the
30322 @command{lsof} command:
30325 lsof | grep /gnu/store/.*bash
30329 @node Bootstrapping
30330 @chapter Bootstrapping
30332 @c Adapted from the ELS 2013 paper.
30334 @cindex bootstrapping
30336 Bootstrapping in our context refers to how the distribution gets built
30337 ``from nothing''. Remember that the build environment of a derivation
30338 contains nothing but its declared inputs (@pxref{Introduction}). So
30339 there's an obvious chicken-and-egg problem: how does the first package
30340 get built? How does the first compiler get compiled? Note that this is
30341 a question of interest only to the curious hacker, not to the regular
30342 user, so you can shamelessly skip this section if you consider yourself
30343 a ``regular user''.
30345 @cindex bootstrap binaries
30346 The GNU system is primarily made of C code, with libc at its core. The
30347 GNU build system itself assumes the availability of a Bourne shell and
30348 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
30349 `grep'. Furthermore, build programs---programs that run
30350 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
30351 (@pxref{Derivations}). Consequently, to be able to build anything at
30352 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
30353 Binutils, libc, and the other packages mentioned above---the
30354 @dfn{bootstrap binaries}.
30356 These bootstrap binaries are ``taken for granted'', though we can also
30357 re-create them if needed (@pxref{Preparing to Use the Bootstrap
30361 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
30362 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
30365 @node Reduced Binary Seed Bootstrap
30366 @section The Reduced Binary Seed Bootstrap
30368 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
30369 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
30370 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
30371 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
30372 ``taken for granted.''
30374 Taking the bootstrap binaries for granted means that we consider them to
30375 be a correct and trustworthy ``seed'' for building the complete system.
30376 Therein lies a problem: the combined size of these bootstrap binaries is
30377 about 250MB (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing
30378 or even inspecting these is next to impossible.
30380 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a
30381 ``Reduced Binary Seed'' bootstrap @footnote{We would like to say: ``Full
30382 Source Bootstrap'' and while we are working towards that goal it would
30383 be hyperbole to use that term for what we do now.}.
30385 The Reduced Binary Seed bootstrap removes the most critical tools---from a
30386 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
30387 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
30388 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
30389 written in Scheme and the Mes C Library, built for TinyCC and for GCC).
30391 Using these new binary seeds the ``missing'' Binutils, GCC, and the GNU
30392 C Library are built from source. From here on the more traditional
30393 bootstrap process resumes. This approach has reduced the bootstrap
30394 binaries in size to about 145MB in Guix v1.1.
30396 The next step that Guix has taken is to replace the shell and all its
30397 utilities with implementations in Guile Scheme, the @emph{Scheme-only
30398 bootstrap}. Gash (@pxref{Gash,,, gash, The Gash manual}) is a
30399 POSIX-compatible shell that replaces Bash, and it comes with Gash Utils
30400 which has minimalist replacements for Awk, the GNU Core Utilities, Grep,
30401 Gzip, Sed, and Tar. The rest of the bootstrap binary seeds that were
30402 removed are now built from source.
30404 Building the GNU System from source is currently only possibly by adding
30405 some historical GNU packages as intermediate steps@footnote{Packages
30406 such as @code{gcc-2.95.3}, @code{binutils-2.14}, @code{glibc-2.2.5},
30407 @code{gzip-1.2.4}, @code{tar-1.22}, and some others. For details, see
30408 @file{gnu/packages/commencement.scm}.}. As Gash and Gash Utils mature,
30409 and GNU packages become more bootstrappable again (e.g., new releases of
30410 GNU Sed will also ship as gzipped tarballs again, as alternative to the
30411 hard to bootstrap @code{xz}-compression), this set of added packages can
30412 hopefully be reduced again.
30414 The graph below shows the resulting dependency graph for
30415 @code{gcc-core-mesboot0}, the bootstrap compiler used for the
30416 traditional bootstrap of the rest of the Guix System.
30418 @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
30419 @image{images/gcc-core-mesboot0-graph,6in,,Dependency graph of gcc-core-mesboot0}
30421 The only significant binary bootstrap seeds that remain@footnote{
30422 Ignoring the 68KB @code{mescc-tools}; that will be removed later,
30423 together with @code{mes}.} are a Scheme intepreter and a Scheme
30424 compiler: GNU Mes and GNU Guile@footnote{Not shown in this graph are the
30425 static binaries for @file{bash}, @code{tar}, and @code{xz} that are used
30426 to get Guile running.}.
30428 This further reduction has brought down the size of the binary seed to
30429 about 60MB for @code{i686-linux} and @code{x86_64-linux}.
30431 Work is ongoing to remove all binary blobs from our free software
30432 bootstrap stack, working towards a Full Source Bootstrap. Also ongoing
30433 is work to bring these bootstraps to the @code{arm-linux} and
30434 @code{aarch64-linux} architectures and to the Hurd.
30436 If you are interested, join us on @samp{#bootstrappable} on the Freenode
30437 IRC network or discuss on @email{bug-mes@@gnu.org} or
30438 @email{gash-devel@@nongnu.org}.
30440 @node Preparing to Use the Bootstrap Binaries
30441 @section Preparing to Use the Bootstrap Binaries
30443 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
30444 @c large image, it's hard to scroll. Oh well.
30445 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
30447 The figure above shows the very beginning of the dependency graph of the
30448 distribution, corresponding to the package definitions of the @code{(gnu
30449 packages bootstrap)} module. A similar figure can be generated with
30450 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
30453 guix graph -t derivation \
30454 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
30455 | dot -Tps > gcc.ps
30458 or, for the further Reduced Binary Seed bootstrap
30461 guix graph -t derivation \
30462 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
30463 | dot -Tps > mes.ps
30466 At this level of detail, things are
30467 slightly complex. First, Guile itself consists of an ELF executable,
30468 along with many source and compiled Scheme files that are dynamically
30469 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
30470 tarball shown in this graph. This tarball is part of Guix's ``source''
30471 distribution, and gets inserted into the store with @code{add-to-store}
30472 (@pxref{The Store}).
30474 But how do we write a derivation that unpacks this tarball and adds it
30475 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
30476 derivation---the first one that gets built---uses @code{bash} as its
30477 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
30478 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
30479 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
30480 the Guix source distribution, whose sole purpose is to allow the Guile
30481 tarball to be unpacked.
30483 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
30484 Guile that can be used to run subsequent build programs. Its first task
30485 is to download tarballs containing the other pre-built binaries---this
30486 is what the @file{.tar.xz.drv} derivations do. Guix modules such as
30487 @code{ftp-client.scm} are used for this purpose. The
30488 @code{module-import.drv} derivations import those modules in a directory
30489 in the store, using the original layout. The
30490 @code{module-import-compiled.drv} derivations compile those modules, and
30491 write them in an output directory with the right layout. This
30492 corresponds to the @code{#:modules} argument of
30493 @code{build-expression->derivation} (@pxref{Derivations}).
30495 Finally, the various tarballs are unpacked by the derivations
30496 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
30497 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
30498 point we have a working C tool chain.
30500 @unnumberedsec Building the Build Tools
30502 Bootstrapping is complete when we have a full tool chain that does not
30503 depend on the pre-built bootstrap tools discussed above. This
30504 no-dependency requirement is verified by checking whether the files of
30505 the final tool chain contain references to the @file{/gnu/store}
30506 directories of the bootstrap inputs. The process that leads to this
30507 ``final'' tool chain is described by the package definitions found in
30508 the @code{(gnu packages commencement)} module.
30510 The @command{guix graph} command allows us to ``zoom out'' compared to
30511 the graph above, by looking at the level of package objects instead of
30512 individual derivations---remember that a package may translate to
30513 several derivations, typically one derivation to download its source,
30514 one to build the Guile modules it needs, and one to actually build the
30515 package from source. The command:
30518 guix graph -t bag \
30519 -e '(@@@@ (gnu packages commencement)
30520 glibc-final-with-bootstrap-bash)' | xdot -
30524 displays the dependency graph leading to the ``final'' C
30525 library@footnote{You may notice the @code{glibc-intermediate} label,
30526 suggesting that it is not @emph{quite} final, but as a good
30527 approximation, we will consider it final.}, depicted below.
30529 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
30531 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
30532 The first tool that gets built with the bootstrap binaries is
30533 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
30534 for all the following packages. From there Findutils and Diffutils get
30537 Then come the first-stage Binutils and GCC, built as pseudo cross
30538 tools---i.e., with @option{--target} equal to @option{--host}. They are
30539 used to build libc. Thanks to this cross-build trick, this libc is
30540 guaranteed not to hold any reference to the initial tool chain.
30542 From there the final Binutils and GCC (not shown above) are built. GCC
30543 uses @command{ld} from the final Binutils, and links programs against
30544 the just-built libc. This tool chain is used to build the other
30545 packages used by Guix and by the GNU Build System: Guile, Bash,
30548 And voilà! At this point we have the complete set of build tools that
30549 the GNU Build System expects. These are in the @code{%final-inputs}
30550 variable of the @code{(gnu packages commencement)} module, and are
30551 implicitly used by any package that uses @code{gnu-build-system}
30552 (@pxref{Build Systems, @code{gnu-build-system}}).
30555 @unnumberedsec Building the Bootstrap Binaries
30557 @cindex bootstrap binaries
30558 Because the final tool chain does not depend on the bootstrap binaries,
30559 those rarely need to be updated. Nevertheless, it is useful to have an
30560 automated way to produce them, should an update occur, and this is what
30561 the @code{(gnu packages make-bootstrap)} module provides.
30563 The following command builds the tarballs containing the bootstrap binaries
30564 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
30565 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
30566 and Guile, and a tarball containing a mixture of Coreutils and other basic
30567 command-line tools):
30570 guix build bootstrap-tarballs
30573 The generated tarballs are those that should be referred to in the
30574 @code{(gnu packages bootstrap)} module mentioned at the beginning of
30577 Still here? Then perhaps by now you've started to wonder: when do we
30578 reach a fixed point? That is an interesting question! The answer is
30579 unknown, but if you would like to investigate further (and have
30580 significant computational and storage resources to do so), then let us
30583 @unnumberedsec Reducing the Set of Bootstrap Binaries
30585 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
30586 binary code! Why is that a problem? It's a problem because these big chunks
30587 of binary code are practically non-auditable, which makes it hard to establish
30588 what source code produced them. Every unauditable binary also leaves us
30589 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
30590 paper @emph{Reflections on Trusting Trust}.
30592 This is mitigated by the fact that our bootstrap binaries were generated
30593 from an earlier Guix revision. Nevertheless it lacks the level of
30594 transparency that we get in the rest of the package dependency graph,
30595 where Guix always gives us a source-to-binary mapping. Thus, our goal
30596 is to reduce the set of bootstrap binaries to the bare minimum.
30598 The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
30599 on-going projects to do that. One of these is about replacing the
30600 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
30601 of increasing complexity, which could be built from source starting from
30602 a simple and auditable assembler.
30604 Our first major achievement is the replacement of of GCC, the GNU C Library
30605 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
30606 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
30607 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
30608 bootstrapped yet and thus we inject them as binary seeds. We call this the
30609 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
30610 binaries! Also, it has eliminated the C compiler binary; i686-linux and
30611 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
30613 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
30614 also looking at any other bootstrap binaries. Your help is welcome!
30617 @chapter Porting to a New Platform
30619 As discussed above, the GNU distribution is self-contained, and
30620 self-containment is achieved by relying on pre-built ``bootstrap
30621 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
30622 operating system kernel, CPU architecture, and application binary
30623 interface (ABI). Thus, to port the distribution to a platform that is
30624 not yet supported, one must build those bootstrap binaries, and update
30625 the @code{(gnu packages bootstrap)} module to use them on that platform.
30627 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
30628 When everything goes well, and assuming the GNU tool chain supports the
30629 target platform, this can be as simple as running a command like this
30633 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
30636 For this to work, the @code{glibc-dynamic-linker} procedure in
30637 @code{(gnu packages bootstrap)} must be augmented to return the right
30638 file name for libc's dynamic linker on that platform; likewise,
30639 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
30640 taught about the new platform.
30642 Once these are built, the @code{(gnu packages bootstrap)} module needs
30643 to be updated to refer to these binaries on the target platform. That
30644 is, the hashes and URLs of the bootstrap tarballs for the new platform
30645 must be added alongside those of the currently supported platforms. The
30646 bootstrap Guile tarball is treated specially: it is expected to be
30647 available locally, and @file{gnu/local.mk} has rules to download it for
30648 the supported architectures; a rule for the new platform must be added
30651 In practice, there may be some complications. First, it may be that the
30652 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
30653 above) is not recognized by all the GNU tools. Typically, glibc
30654 recognizes some of these, whereas GCC uses an extra @option{--with-abi}
30655 configure flag (see @code{gcc.scm} for examples of how to handle this).
30656 Second, some of the required packages could fail to build for that
30657 platform. Lastly, the generated binaries could be broken for some
30660 @c *********************************************************************
30661 @include contributing.texi
30663 @c *********************************************************************
30664 @node Acknowledgments
30665 @chapter Acknowledgments
30667 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
30668 which was designed and
30669 implemented by Eelco Dolstra, with contributions from other people (see
30670 the @file{nix/AUTHORS} file in Guix). Nix pioneered functional package
30671 management, and promoted unprecedented features, such as transactional
30672 package upgrades and rollbacks, per-user profiles, and referentially
30673 transparent build processes. Without this work, Guix would not exist.
30675 The Nix-based software distributions, Nixpkgs and NixOS, have also been
30676 an inspiration for Guix.
30678 GNU@tie{}Guix itself is a collective work with contributions from a
30679 number of people. See the @file{AUTHORS} file in Guix for more
30680 information on these fine people. The @file{THANKS} file lists people
30681 who have helped by reporting bugs, taking care of the infrastructure,
30682 providing artwork and themes, making suggestions, and more---thank you!
30685 @c *********************************************************************
30686 @node GNU Free Documentation License
30687 @appendix GNU Free Documentation License
30688 @cindex license, GNU Free Documentation License
30689 @include fdl-1.3.texi
30691 @c *********************************************************************
30692 @node Concept Index
30693 @unnumbered Concept Index
30696 @node Programming Index
30697 @unnumbered Programming Index
30698 @syncodeindex tp fn
30699 @syncodeindex vr fn
30704 @c Local Variables:
30705 @c ispell-local-dictionary: "american";