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
782 @c FIXME: Specify a version number once a release has been made.
783 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
785 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON} 3.x;
786 @item @url{https://zlib.net, zlib};
787 @item @url{https://www.gnu.org/software/make/, GNU Make}.
790 The following dependencies are optional:
794 @c Note: We need at least 0.12.0 for 'userauth-gssapi!'.
795 Support for build offloading (@pxref{Daemon Offload Setup}) and
796 @command{guix copy} (@pxref{Invoking guix copy}) depends on
797 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
798 version 0.12.0 or later.
801 When @url{https://www.nongnu.org/lzip/lzlib.html, lzlib} is available, lzlib
802 substitutes can be used and @command{guix publish} can compress substitutes
806 When @url{http://www.bzip.org, libbz2} is available,
807 @command{guix-daemon} can use it to compress build logs.
810 Unless @option{--disable-daemon} was passed to @command{configure}, the
811 following packages are also needed:
814 @item @url{https://gnupg.org/, GNU libgcrypt};
815 @item @url{https://sqlite.org, SQLite 3};
816 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
820 @cindex state directory
821 When configuring Guix on a system that already has a Guix installation,
822 be sure to specify the same state directory as the existing installation
823 using the @option{--localstatedir} option of the @command{configure}
824 script (@pxref{Directory Variables, @code{localstatedir},, standards,
825 GNU Coding Standards}). Usually, this @var{localstatedir} option is
826 set to the value @file{/var}. The @command{configure} script protects
827 against unintended misconfiguration of @var{localstatedir} so you do not
828 inadvertently corrupt your store (@pxref{The Store}).
830 @node Running the Test Suite
831 @section Running the Test Suite
834 After a successful @command{configure} and @code{make} run, it is a good
835 idea to run the test suite. It can help catch issues with the setup or
836 environment, or bugs in Guix itself---and really, reporting test
837 failures is a good way to help improve the software. To run the test
844 Test cases can run in parallel: you can use the @code{-j} option of
845 GNU@tie{}make to speed things up. The first run may take a few minutes
846 on a recent machine; subsequent runs will be faster because the store
847 that is created for test purposes will already have various things in
850 It is also possible to run a subset of the tests by defining the
851 @code{TESTS} makefile variable as in this example:
854 make check TESTS="tests/store.scm tests/cpio.scm"
857 By default, tests results are displayed at a file level. In order to
858 see the details of every individual test cases, it is possible to define
859 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
862 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
865 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
866 @file{test-suite.log} file. Please specify the Guix version being used
867 as well as version numbers of the dependencies (@pxref{Requirements}) in
870 Guix also comes with a whole-system test suite that tests complete
871 Guix System instances. It can only run on systems where
872 Guix is already installed, using:
879 or, again, by defining @code{TESTS} to select a subset of tests to run:
882 make check-system TESTS="basic mcron"
885 These system tests are defined in the @code{(gnu tests @dots{})}
886 modules. They work by running the operating systems under test with
887 lightweight instrumentation in a virtual machine (VM). They can be
888 computationally intensive or rather cheap, depending on whether
889 substitutes are available for their dependencies (@pxref{Substitutes}).
890 Some of them require a lot of storage space to hold VM images.
892 Again in case of test failures, please send @email{bug-guix@@gnu.org}
895 @node Setting Up the Daemon
896 @section Setting Up the Daemon
899 Operations such as building a package or running the garbage collector
900 are all performed by a specialized process, the @dfn{build daemon}, on
901 behalf of clients. Only the daemon may access the store and its
902 associated database. Thus, any operation that manipulates the store
903 goes through the daemon. For instance, command-line tools such as
904 @command{guix package} and @command{guix build} communicate with the
905 daemon (@i{via} remote procedure calls) to instruct it what to do.
907 The following sections explain how to prepare the build daemon's
908 environment. See also @ref{Substitutes}, for information on how to allow
909 the daemon to download pre-built binaries.
912 * Build Environment Setup:: Preparing the isolated build environment.
913 * Daemon Offload Setup:: Offloading builds to remote machines.
914 * SELinux Support:: Using an SELinux policy for the daemon.
917 @node Build Environment Setup
918 @subsection Build Environment Setup
920 @cindex build environment
921 In a standard multi-user setup, Guix and its daemon---the
922 @command{guix-daemon} program---are installed by the system
923 administrator; @file{/gnu/store} is owned by @code{root} and
924 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
925 Guix tools to build packages or otherwise access the store, and the
926 daemon will do it on their behalf, ensuring that the store is kept in a
927 consistent state, and allowing built packages to be shared among users.
930 When @command{guix-daemon} runs as @code{root}, you may not want package
931 build processes themselves to run as @code{root} too, for obvious
932 security reasons. To avoid that, a special pool of @dfn{build users}
933 should be created for use by build processes started by the daemon.
934 These build users need not have a shell and a home directory: they will
935 just be used when the daemon drops @code{root} privileges in build
936 processes. Having several such users allows the daemon to launch
937 distinct build processes under separate UIDs, which guarantees that they
938 do not interfere with each other---an essential feature since builds are
939 regarded as pure functions (@pxref{Introduction}).
941 On a GNU/Linux system, a build user pool may be created like this (using
942 Bash syntax and the @code{shadow} commands):
944 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
945 @c for why `-G' is needed.
947 # groupadd --system guixbuild
948 # for i in `seq -w 1 10`;
950 useradd -g guixbuild -G guixbuild \
951 -d /var/empty -s `which nologin` \
952 -c "Guix build user $i" --system \
958 The number of build users determines how many build jobs may run in
959 parallel, as specified by the @option{--max-jobs} option
960 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
961 @command{guix system vm} and related commands, you may need to add the
962 build users to the @code{kvm} group so they can access @file{/dev/kvm},
963 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
964 (@pxref{Invoking guix system}).
966 The @code{guix-daemon} program may then be run as @code{root} with the
967 following command@footnote{If your machine uses the systemd init system,
968 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
969 file in @file{/etc/systemd/system} will ensure that
970 @command{guix-daemon} is automatically started. Similarly, if your
971 machine uses the Upstart init system, drop the
972 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
973 file in @file{/etc/init}.}:
976 # guix-daemon --build-users-group=guixbuild
981 This way, the daemon starts build processes in a chroot, under one of
982 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
983 environment contains nothing but:
985 @c Keep this list in sync with libstore/build.cc! -----------------------
988 a minimal @code{/dev} directory, created mostly independently from the
989 host @code{/dev}@footnote{``Mostly'', because while the set of files
990 that appear in the chroot's @code{/dev} is fixed, most of these files
991 can only be created if the host has them.};
994 the @code{/proc} directory; it only shows the processes of the container
995 since a separate PID name space is used;
998 @file{/etc/passwd} with an entry for the current user and an entry for
1002 @file{/etc/group} with an entry for the user's group;
1005 @file{/etc/hosts} with an entry that maps @code{localhost} to
1009 a writable @file{/tmp} directory.
1012 You can influence the directory where the daemon stores build trees
1013 @i{via} the @env{TMPDIR} environment variable. However, the build tree
1014 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
1015 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
1016 This way, the value of @env{TMPDIR} does not leak inside build
1017 environments, which avoids discrepancies in cases where build processes
1018 capture the name of their build tree.
1022 The daemon also honors the @env{http_proxy} and @env{https_proxy}
1023 environment variables for HTTP and HTTPS downloads it performs, be it
1024 for fixed-output derivations (@pxref{Derivations}) or for substitutes
1025 (@pxref{Substitutes}).
1027 If you are installing Guix as an unprivileged user, it is still possible
1028 to run @command{guix-daemon} provided you pass @option{--disable-chroot}.
1029 However, build processes will not be isolated from one another, and not
1030 from the rest of the system. Thus, build processes may interfere with
1031 each other, and may access programs, libraries, and other files
1032 available on the system---making it much harder to view them as
1033 @emph{pure} functions.
1036 @node Daemon Offload Setup
1037 @subsection Using the Offload Facility
1041 When desired, the build daemon can @dfn{offload} derivation builds to
1042 other machines running Guix, using the @code{offload} @dfn{build
1043 hook}@footnote{This feature is available only when
1044 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1045 present.}. When that
1046 feature is enabled, a list of user-specified build machines is read from
1047 @file{/etc/guix/machines.scm}; every time a build is requested, for
1048 instance via @code{guix build}, the daemon attempts to offload it to one
1049 of the machines that satisfy the constraints of the derivation, in
1050 particular its system type---e.g., @file{x86_64-linux}. Missing
1051 prerequisites for the build are copied over SSH to the target machine,
1052 which then proceeds with the build; upon success the output(s) of the
1053 build are copied back to the initial machine.
1055 The @file{/etc/guix/machines.scm} file typically looks like this:
1058 (list (build-machine
1059 (name "eightysix.example.org")
1060 (system "x86_64-linux")
1061 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1063 (speed 2.)) ;incredibly fast!
1066 (name "armeight.example.org")
1067 (system "aarch64-linux")
1068 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1071 (string-append (getenv "HOME")
1072 "/.ssh/identity-for-guix"))))
1076 In the example above we specify a list of two build machines, one for
1077 the @code{x86_64} architecture and one for the @code{aarch64}
1080 In fact, this file is---not surprisingly!---a Scheme file that is
1081 evaluated when the @code{offload} hook is started. Its return value
1082 must be a list of @code{build-machine} objects. While this example
1083 shows a fixed list of build machines, one could imagine, say, using
1084 DNS-SD to return a list of potential build machines discovered in the
1085 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1086 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1089 @deftp {Data Type} build-machine
1090 This data type represents build machines to which the daemon may offload
1091 builds. The important fields are:
1096 The host name of the remote machine.
1099 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
1102 The user account to use when connecting to the remote machine over SSH.
1103 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1104 allow non-interactive logins.
1107 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1108 This is used to authenticate the machine when we connect to it. It is a
1109 long string that looks like this:
1112 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1115 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1116 key can be found in a file such as
1117 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1119 If the machine is running the SSH daemon of GNU@tie{}lsh,
1120 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1121 similar file. It can be converted to the OpenSSH format using
1122 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1125 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1126 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1131 A number of optional fields may be specified:
1135 @item @code{port} (default: @code{22})
1136 Port number of SSH server on the machine.
1138 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1139 The SSH private key file to use when connecting to the machine, in
1140 OpenSSH format. This key must not be protected with a passphrase.
1142 Note that the default value is the private key @emph{of the root
1143 account}. Make sure it exists if you use the default.
1145 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1146 @itemx @code{compression-level} (default: @code{3})
1147 The SSH-level compression methods and compression level requested.
1149 Note that offloading relies on SSH compression to reduce bandwidth usage
1150 when transferring files to and from build machines.
1152 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1153 File name of the Unix-domain socket @command{guix-daemon} is listening
1156 @item @code{parallel-builds} (default: @code{1})
1157 The number of builds that may run in parallel on the machine.
1159 @item @code{speed} (default: @code{1.0})
1160 A ``relative speed factor''. The offload scheduler will tend to prefer
1161 machines with a higher speed factor.
1163 @item @code{features} (default: @code{'()})
1164 A list of strings denoting specific features supported by the machine.
1165 An example is @code{"kvm"} for machines that have the KVM Linux modules
1166 and corresponding hardware support. Derivations can request features by
1167 name, and they will be scheduled on matching build machines.
1172 The @command{guix} command must be in the search path on the build
1173 machines. You can check whether this is the case by running:
1176 ssh build-machine guix repl --version
1179 There is one last thing to do once @file{machines.scm} is in place. As
1180 explained above, when offloading, files are transferred back and forth
1181 between the machine stores. For this to work, you first need to
1182 generate a key pair on each machine to allow the daemon to export signed
1183 archives of files from the store (@pxref{Invoking guix archive}):
1186 # guix archive --generate-key
1190 Each build machine must authorize the key of the master machine so that
1191 it accepts store items it receives from the master:
1194 # guix archive --authorize < master-public-key.txt
1198 Likewise, the master machine must authorize the key of each build machine.
1200 All the fuss with keys is here to express pairwise mutual trust
1201 relations between the master and the build machines. Concretely, when
1202 the master receives files from a build machine (and @i{vice versa}), its
1203 build daemon can make sure they are genuine, have not been tampered
1204 with, and that they are signed by an authorized key.
1206 @cindex offload test
1207 To test whether your setup is operational, run this command on the
1214 This will attempt to connect to each of the build machines specified in
1215 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1216 available on each machine, attempt to export to the machine and import
1217 from it, and report any error in the process.
1219 If you want to test a different machine file, just specify it on the
1223 # guix offload test machines-qualif.scm
1226 Last, you can test the subset of the machines whose name matches a
1227 regular expression like this:
1230 # guix offload test machines.scm '\.gnu\.org$'
1233 @cindex offload status
1234 To display the current load of all build hosts, run this command on the
1238 # guix offload status
1242 @node SELinux Support
1243 @subsection SELinux Support
1245 @cindex SELinux, daemon policy
1246 @cindex mandatory access control, SELinux
1247 @cindex security, guix-daemon
1248 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1249 can be installed on a system where SELinux is enabled, in order to label
1250 Guix files and to specify the expected behavior of the daemon. Since
1251 Guix System does not provide an SELinux base policy, the daemon policy cannot
1252 be used on Guix System.
1254 @subsubsection Installing the SELinux policy
1255 @cindex SELinux, policy installation
1256 To install the policy run this command as root:
1259 semodule -i etc/guix-daemon.cil
1262 Then relabel the file system with @code{restorecon} or by a different
1263 mechanism provided by your system.
1265 Once the policy is installed, the file system has been relabeled, and
1266 the daemon has been restarted, it should be running in the
1267 @code{guix_daemon_t} context. You can confirm this with the following
1271 ps -Zax | grep guix-daemon
1274 Monitor the SELinux log files as you run a command like @code{guix build
1275 hello} to convince yourself that SELinux permits all necessary
1278 @subsubsection Limitations
1279 @cindex SELinux, limitations
1281 This policy is not perfect. Here is a list of limitations or quirks
1282 that should be considered when deploying the provided SELinux policy for
1287 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1288 operations involve contexts that have anything to do with
1289 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1290 but it would be preferrable to define socket rules for only this label.
1293 @code{guix gc} cannot access arbitrary links to profiles. By design,
1294 the file label of the destination of a symlink is independent of the
1295 file label of the link itself. Although all profiles under
1296 $localstatedir are labelled, the links to these profiles inherit the
1297 label of the directory they are in. For links in the user’s home
1298 directory this will be @code{user_home_t}. But for links from the root
1299 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1300 directory, etc, this won’t work. @code{guix gc} would be prevented from
1301 reading and following these links.
1304 The daemon’s feature to listen for TCP connections might no longer work.
1305 This might require extra rules, because SELinux treats network sockets
1306 differently from files.
1309 Currently all files with a name matching the regular expression
1310 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1311 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1312 that name in any profile would be permitted to run in the
1313 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1314 build a package that provides this executable and convince a user to
1315 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1316 At that point SELinux could not prevent it from accessing files that are
1317 allowed for processes in that domain.
1319 We could generate a much more restrictive policy at installation time,
1320 so that only the @emph{exact} file name of the currently installed
1321 @code{guix-daemon} executable would be labelled with
1322 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1323 The downside is that root would have to install or upgrade the policy at
1324 installation time whenever the Guix package that provides the
1325 effectively running @code{guix-daemon} executable is upgraded.
1328 @node Invoking guix-daemon
1329 @section Invoking @command{guix-daemon}
1331 The @command{guix-daemon} program implements all the functionality to
1332 access the store. This includes launching build processes, running the
1333 garbage collector, querying the availability of a build result, etc. It
1334 is normally run as @code{root} like this:
1337 # guix-daemon --build-users-group=guixbuild
1341 For details on how to set it up, @pxref{Setting Up the Daemon}.
1344 @cindex container, build environment
1345 @cindex build environment
1346 @cindex reproducible builds
1347 By default, @command{guix-daemon} launches build processes under
1348 different UIDs, taken from the build group specified with
1349 @option{--build-users-group}. In addition, each build process is run in a
1350 chroot environment that only contains the subset of the store that the
1351 build process depends on, as specified by its derivation
1352 (@pxref{Programming Interface, derivation}), plus a set of specific
1353 system directories. By default, the latter contains @file{/dev} and
1354 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1355 @dfn{container}: in addition to having its own file system tree, it has
1356 a separate mount name space, its own PID name space, network name space,
1357 etc. This helps achieve reproducible builds (@pxref{Features}).
1359 When the daemon performs a build on behalf of the user, it creates a
1360 build directory under @file{/tmp} or under the directory specified by
1361 its @env{TMPDIR} environment variable. This directory is shared with
1362 the container for the duration of the build, though within the container,
1363 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1365 The build directory is automatically deleted upon completion, unless the
1366 build failed and the client specified @option{--keep-failed}
1367 (@pxref{Invoking guix build, @option{--keep-failed}}).
1369 The daemon listens for connections and spawns one sub-process for each session
1370 started by a client (one of the @command{guix} sub-commands). The
1371 @command{guix processes} command allows you to get an overview of the activity
1372 on your system by viewing each of the active sessions and clients.
1373 @xref{Invoking guix processes}, for more information.
1375 The following command-line options are supported:
1378 @item --build-users-group=@var{group}
1379 Take users from @var{group} to run build processes (@pxref{Setting Up
1380 the Daemon, build users}).
1382 @item --no-substitutes
1384 Do not use substitutes for build products. That is, always build things
1385 locally instead of allowing downloads of pre-built binaries
1386 (@pxref{Substitutes}).
1388 When the daemon runs with @option{--no-substitutes}, clients can still
1389 explicitly enable substitution @i{via} the @code{set-build-options}
1390 remote procedure call (@pxref{The Store}).
1392 @item --substitute-urls=@var{urls}
1393 @anchor{daemon-substitute-urls}
1394 Consider @var{urls} the default whitespace-separated list of substitute
1395 source URLs. When this option is omitted,
1396 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1398 This means that substitutes may be downloaded from @var{urls}, as long
1399 as they are signed by a trusted signature (@pxref{Substitutes}).
1403 Do not use offload builds to other machines (@pxref{Daemon Offload
1404 Setup}). That is, always build things locally instead of offloading
1405 builds to remote machines.
1407 @item --cache-failures
1408 Cache build failures. By default, only successful builds are cached.
1410 When this option is used, @command{guix gc --list-failures} can be used
1411 to query the set of store items marked as failed; @command{guix gc
1412 --clear-failures} removes store items from the set of cached failures.
1413 @xref{Invoking guix gc}.
1415 @item --cores=@var{n}
1417 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1420 The default value is @code{0}, but it may be overridden by clients, such
1421 as the @option{--cores} option of @command{guix build} (@pxref{Invoking
1424 The effect is to define the @env{NIX_BUILD_CORES} environment variable
1425 in the build process, which can then use it to exploit internal
1426 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1428 @item --max-jobs=@var{n}
1430 Allow at most @var{n} build jobs in parallel. The default value is
1431 @code{1}. Setting it to @code{0} means that no builds will be performed
1432 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1433 Setup}), or simply fail.
1435 @item --max-silent-time=@var{seconds}
1436 When the build or substitution process remains silent for more than
1437 @var{seconds}, terminate it and report a build failure.
1439 The default value is @code{0}, which disables the timeout.
1441 The value specified here can be overridden by clients (@pxref{Common
1442 Build Options, @option{--max-silent-time}}).
1444 @item --timeout=@var{seconds}
1445 Likewise, when the build or substitution process lasts for more than
1446 @var{seconds}, terminate it and report a build failure.
1448 The default value is @code{0}, which disables the timeout.
1450 The value specified here can be overridden by clients (@pxref{Common
1451 Build Options, @option{--timeout}}).
1453 @item --rounds=@var{N}
1454 Build each derivation @var{n} times in a row, and raise an error if
1455 consecutive build results are not bit-for-bit identical. Note that this
1456 setting can be overridden by clients such as @command{guix build}
1457 (@pxref{Invoking guix build}).
1459 When used in conjunction with @option{--keep-failed}, the differing
1460 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1461 This makes it easy to look for differences between the two results.
1464 Produce debugging output.
1466 This is useful to debug daemon start-up issues, but then it may be
1467 overridden by clients, for example the @option{--verbosity} option of
1468 @command{guix build} (@pxref{Invoking guix build}).
1470 @item --chroot-directory=@var{dir}
1471 Add @var{dir} to the build chroot.
1473 Doing this may change the result of build processes---for instance if
1474 they use optional dependencies found in @var{dir} when it is available,
1475 and not otherwise. For that reason, it is not recommended to do so.
1476 Instead, make sure that each derivation declares all the inputs that it
1479 @item --disable-chroot
1480 Disable chroot builds.
1482 Using this option is not recommended since, again, it would allow build
1483 processes to gain access to undeclared dependencies. It is necessary,
1484 though, when @command{guix-daemon} is running under an unprivileged user
1487 @item --log-compression=@var{type}
1488 Compress build logs according to @var{type}, one of @code{gzip},
1489 @code{bzip2}, or @code{none}.
1491 Unless @option{--lose-logs} is used, all the build logs are kept in the
1492 @var{localstatedir}. To save space, the daemon automatically compresses
1493 them with Bzip2 by default.
1495 @item --disable-deduplication
1496 @cindex deduplication
1497 Disable automatic file ``deduplication'' in the store.
1499 By default, files added to the store are automatically ``deduplicated'':
1500 if a newly added file is identical to another one found in the store,
1501 the daemon makes the new file a hard link to the other file. This can
1502 noticeably reduce disk usage, at the expense of slightly increased
1503 input/output load at the end of a build process. This option disables
1506 @item --gc-keep-outputs[=yes|no]
1507 Tell whether the garbage collector (GC) must keep outputs of live
1511 @cindex garbage collector roots
1512 When set to @code{yes}, the GC will keep the outputs of any live
1513 derivation available in the store---the @file{.drv} files. The default
1514 is @code{no}, meaning that derivation outputs are kept only if they are
1515 reachable from a GC root. @xref{Invoking guix gc}, for more on GC
1518 @item --gc-keep-derivations[=yes|no]
1519 Tell whether the garbage collector (GC) must keep derivations
1520 corresponding to live outputs.
1522 When set to @code{yes}, as is the case by default, the GC keeps
1523 derivations---i.e., @file{.drv} files---as long as at least one of their
1524 outputs is live. This allows users to keep track of the origins of
1525 items in their store. Setting it to @code{no} saves a bit of disk
1528 In this way, setting @option{--gc-keep-derivations} to @code{yes} causes
1529 liveness to flow from outputs to derivations, and setting
1530 @option{--gc-keep-outputs} to @code{yes} causes liveness to flow from
1531 derivations to outputs. When both are set to @code{yes}, the effect is
1532 to keep all the build prerequisites (the sources, compiler, libraries,
1533 and other build-time tools) of live objects in the store, regardless of
1534 whether these prerequisites are reachable from a GC root. This is
1535 convenient for developers since it saves rebuilds or downloads.
1537 @item --impersonate-linux-2.6
1538 On Linux-based systems, impersonate Linux 2.6. This means that the
1539 kernel's @command{uname} system call will report 2.6 as the release number.
1541 This might be helpful to build programs that (usually wrongfully) depend
1542 on the kernel version number.
1545 Do not keep build logs. By default they are kept under
1546 @file{@var{localstatedir}/guix/log}.
1548 @item --system=@var{system}
1549 Assume @var{system} as the current system type. By default it is the
1550 architecture/kernel pair found at configure time, such as
1551 @code{x86_64-linux}.
1553 @item --listen=@var{endpoint}
1554 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1555 as the file name of a Unix-domain socket if it starts with
1556 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1557 host name or host name and port to listen to. Here are a few examples:
1560 @item --listen=/gnu/var/daemon
1561 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1562 creating it if needed.
1564 @item --listen=localhost
1565 @cindex daemon, remote access
1566 @cindex remote access to the daemon
1567 @cindex daemon, cluster setup
1568 @cindex clusters, daemon setup
1569 Listen for TCP connections on the network interface corresponding to
1570 @code{localhost}, on port 44146.
1572 @item --listen=128.0.0.42:1234
1573 Listen for TCP connections on the network interface corresponding to
1574 @code{128.0.0.42}, on port 1234.
1577 This option can be repeated multiple times, in which case
1578 @command{guix-daemon} accepts connections on all the specified
1579 endpoints. Users can tell client commands what endpoint to connect to
1580 by setting the @env{GUIX_DAEMON_SOCKET} environment variable
1581 (@pxref{The Store, @env{GUIX_DAEMON_SOCKET}}).
1584 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1585 @option{--listen=@var{host}} is suitable on local networks, such as
1586 clusters, where only trusted nodes may connect to the build daemon. In
1587 other cases where remote access to the daemon is needed, we recommend
1588 using Unix-domain sockets along with SSH.
1591 When @option{--listen} is omitted, @command{guix-daemon} listens for
1592 connections on the Unix-domain socket located at
1593 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1597 @node Application Setup
1598 @section Application Setup
1600 @cindex foreign distro
1601 When using Guix on top of GNU/Linux distribution other than Guix System---a
1602 so-called @dfn{foreign distro}---a few additional steps are needed to
1603 get everything in place. Here are some of them.
1607 @anchor{locales-and-locpath}
1608 @cindex locales, when not on Guix System
1610 @vindex GUIX_LOCPATH
1611 Packages installed @i{via} Guix will not use the locale data of the
1612 host system. Instead, you must first install one of the locale packages
1613 available with Guix and then define the @env{GUIX_LOCPATH} environment
1617 $ guix install glibc-locales
1618 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1621 Note that the @code{glibc-locales} package contains data for all the
1622 locales supported by the GNU@tie{}libc and weighs in at around
1623 917@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1624 limited to a few UTF-8 locales.
1626 The @env{GUIX_LOCPATH} variable plays a role similar to @env{LOCPATH}
1627 (@pxref{Locale Names, @env{LOCPATH},, libc, The GNU C Library Reference
1628 Manual}). There are two important differences though:
1632 @env{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1633 provided by foreign distros. Thus, using @env{GUIX_LOCPATH} allows you
1634 to make sure the programs of the foreign distro will not end up loading
1635 incompatible locale data.
1638 libc suffixes each entry of @env{GUIX_LOCPATH} with @code{/X.Y}, where
1639 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1640 should your Guix profile contain a mixture of programs linked against
1641 different libc version, each libc version will only try to load locale
1642 data in the right format.
1645 This is important because the locale data format used by different libc
1646 versions may be incompatible.
1648 @subsection Name Service Switch
1650 @cindex name service switch, glibc
1651 @cindex NSS (name service switch), glibc
1652 @cindex nscd (name service caching daemon)
1653 @cindex name service caching daemon (nscd)
1654 When using Guix on a foreign distro, we @emph{strongly recommend} that
1655 the system run the GNU C library's @dfn{name service cache daemon},
1656 @command{nscd}, which should be listening on the
1657 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1658 installed with Guix may fail to look up host names or user accounts, or
1659 may even crash. The next paragraphs explain why.
1661 @cindex @file{nsswitch.conf}
1662 The GNU C library implements a @dfn{name service switch} (NSS), which is
1663 an extensible mechanism for ``name lookups'' in general: host name
1664 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1665 The GNU C Library Reference Manual}).
1667 @cindex Network information service (NIS)
1668 @cindex NIS (Network information service)
1669 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1670 lookup implementations: for example, the @code{nss-mdns} plugin allow
1671 resolution of @code{.local} host names, the @code{nis} plugin allows
1672 user account lookup using the Network information service (NIS), and so
1673 on. These extra ``lookup services'' are configured system-wide in
1674 @file{/etc/nsswitch.conf}, and all the programs running on the system
1675 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1678 When they perform a name lookup---for instance by calling the
1679 @code{getaddrinfo} function in C---applications first try to connect to
1680 the nscd; on success, nscd performs name lookups on their behalf. If
1681 the nscd is not running, then they perform the name lookup by
1682 themselves, by loading the name lookup services into their own address
1683 space and running it. These name lookup services---the
1684 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1685 the host system's C library, rather than from the C library the
1686 application is linked against (the C library coming from Guix).
1688 And this is where the problem is: if your application is linked against
1689 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1690 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1691 likely crash or have its name lookups fail unexpectedly.
1693 Running @command{nscd} on the system, among other advantages, eliminates
1694 this binary incompatibility problem because those @code{libnss_*.so}
1695 files are loaded in the @command{nscd} process, not in applications
1698 @subsection X11 Fonts
1701 The majority of graphical applications use Fontconfig to locate and
1702 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1703 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1704 by default. Thus, to allow graphical applications installed with Guix
1705 to display fonts, you have to install fonts with Guix as well.
1706 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1707 @code{font-gnu-freefont}.
1709 @cindex @code{fc-cache}
1711 Once you have installed or removed fonts, or when you notice an
1712 application that does not find fonts, you may need to install Fontconfig
1713 and to force an update of its font cache by running:
1716 guix install fontconfig
1720 To display text written in Chinese languages, Japanese, or Korean in
1721 graphical applications, consider installing
1722 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1723 has multiple outputs, one per language family (@pxref{Packages with
1724 Multiple Outputs}). For instance, the following command installs fonts
1725 for Chinese languages:
1728 guix install font-adobe-source-han-sans:cn
1731 @cindex @code{xterm}
1732 Older programs such as @command{xterm} do not use Fontconfig and instead
1733 rely on server-side font rendering. Such programs require to specify a
1734 full name of a font using XLFD (X Logical Font Description), like this:
1737 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1740 To be able to use such full names for the TrueType fonts installed in
1741 your Guix profile, you need to extend the font path of the X server:
1743 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1744 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1746 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1749 @cindex @code{xlsfonts}
1750 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1751 to make sure your TrueType fonts are listed there.
1754 @subsection X.509 Certificates
1756 @cindex @code{nss-certs}
1757 The @code{nss-certs} package provides X.509 certificates, which allow
1758 programs to authenticate Web servers accessed over HTTPS.
1760 When using Guix on a foreign distro, you can install this package and
1761 define the relevant environment variables so that packages know where to
1762 look for certificates. @xref{X.509 Certificates}, for detailed
1765 @subsection Emacs Packages
1767 @cindex @code{emacs}
1768 When you install Emacs packages with Guix, the Elisp files are placed
1769 under the @file{share/emacs/site-lisp/} directory of the profile in
1770 which they are installed. The Elisp libraries are made available to
1771 Emacs through the @env{EMACSLOADPATH} environment variable, which is
1772 set when installing Emacs itself.
1774 Additionally, autoload definitions are automatically evaluated at the
1775 initialization of Emacs, by the Guix-specific
1776 @code{guix-emacs-autoload-packages} procedure. If, for some reason, you
1777 want to avoid auto-loading the Emacs packages installed with Guix, you
1778 can do so by running Emacs with the @option{--no-site-file} option
1779 (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1782 @node Upgrading Guix
1783 @section Upgrading Guix
1785 @cindex Upgrading Guix, on a foreign distro
1787 To upgrade Guix, run:
1793 @xref{Invoking guix pull}, for more information.
1795 @cindex upgrading Guix for the root user, on a foreign distro
1796 @cindex upgrading the Guix daemon, on a foreign distro
1797 @cindex @command{guix pull} for the root user, on a foreign distro
1799 On a foreign distro, you can upgrade the build daemon by running:
1806 followed by (assuming your distro uses the systemd service management
1810 systemctl restart guix-daemon.service
1813 On Guix System, upgrading the daemon is achieved by reconfiguring the
1814 system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
1818 @c *********************************************************************
1819 @node System Installation
1820 @chapter System Installation
1822 @cindex installing Guix System
1823 @cindex Guix System, installation
1824 This section explains how to install Guix System
1825 on a machine. Guix, as a package manager, can
1826 also be installed on top of a running GNU/Linux system,
1827 @pxref{Installation}.
1831 @c This paragraph is for people reading this from tty2 of the
1832 @c installation image.
1833 You are reading this documentation with an Info reader. For details on
1834 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1835 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1836 Info}. Hit @kbd{l} afterwards to come back here.
1838 Alternatively, run @command{info info} in another tty to keep the manual
1844 * Limitations:: What you can expect.
1845 * Hardware Considerations:: Supported hardware.
1846 * USB Stick and DVD Installation:: Preparing the installation medium.
1847 * Preparing for Installation:: Networking, partitioning, etc.
1848 * Guided Graphical Installation:: Easy graphical installation.
1849 * Manual Installation:: Manual installation for wizards.
1850 * After System Installation:: When installation succeeded.
1851 * Installing Guix in a VM:: Guix System playground.
1852 * Building the Installation Image:: How this comes to be.
1856 @section Limitations
1858 We consider Guix System to be ready for a wide range of ``desktop'' and server
1859 use cases. The reliability guarantees it provides---transactional upgrades
1860 and rollbacks, reproducibility---make it a solid foundation.
1862 Nevertheless, before you proceed with the installation, be aware of the
1863 following noteworthy limitations applicable to version @value{VERSION}:
1867 Support for the Logical Volume Manager (LVM) is missing.
1870 More and more system services are provided (@pxref{Services}), but some
1874 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1875 as well as a number of X11 window managers. However, KDE is currently
1879 More than a disclaimer, this is an invitation to report issues (and success
1880 stories!), and to join us in improving it. @xref{Contributing}, for more
1884 @node Hardware Considerations
1885 @section Hardware Considerations
1887 @cindex hardware support on Guix System
1888 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1889 builds around the kernel Linux-libre, which means that only hardware for
1890 which free software drivers and firmware exist is supported. Nowadays,
1891 a wide range of off-the-shelf hardware is supported on
1892 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1893 Ethernet controllers. Unfortunately, there are still areas where
1894 hardware vendors deny users control over their own computing, and such
1895 hardware is not supported on Guix System.
1897 @cindex WiFi, hardware support
1898 One of the main areas where free drivers or firmware are lacking is WiFi
1899 devices. WiFi devices known to work include those using Atheros chips
1900 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1901 driver, and those using Broadcom/AirForce chips (BCM43xx with
1902 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1903 Linux-libre driver. Free firmware exists for both and is available
1904 out-of-the-box on Guix System, as part of @code{%base-firmware}
1905 (@pxref{operating-system Reference, @code{firmware}}).
1907 @cindex RYF, Respects Your Freedom
1908 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1909 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1910 certification program for hardware products that respect your freedom
1911 and your privacy and ensure that you have control over your device. We
1912 encourage you to check the list of RYF-certified devices.
1914 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1915 web site. It contains a catalog of hardware devices with information
1916 about their support in GNU/Linux.
1919 @node USB Stick and DVD Installation
1920 @section USB Stick and DVD Installation
1922 An ISO-9660 installation image that can be written to a USB stick or
1923 burnt to a DVD can be downloaded from
1924 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz},
1925 where you can replace @code{x86_64-linux} with one of:
1929 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1932 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1935 @c start duplication of authentication part from ``Binary Installation''
1936 Make sure to download the associated @file{.sig} file and to verify the
1937 authenticity of the image against it, along these lines:
1940 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
1941 $ gpg --verify guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
1944 If that command fails because you do not have the required public key,
1945 then run this command to import it:
1948 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
1949 -qO - | gpg --import -
1953 and rerun the @code{gpg --verify} command.
1955 Take note that a warning like ``This key is not certified with a trusted
1956 signature!'' is normal.
1960 This image contains the tools necessary for an installation.
1961 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1963 @unnumberedsubsec Copying to a USB Stick
1965 To copy the image to a USB stick, follow these steps:
1969 Decompress the image using the @command{xz} command:
1972 xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
1976 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1977 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1978 copy the image with:
1981 dd if=guix-system-install-@value{VERSION}.x86_64-linux.iso of=/dev/sdX status=progress
1985 Access to @file{/dev/sdX} usually requires root privileges.
1988 @unnumberedsubsec Burning on a DVD
1990 To copy the image to a DVD, follow these steps:
1994 Decompress the image using the @command{xz} command:
1997 xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
2001 Insert a blank DVD into your machine, and determine
2002 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
2003 copy the image with:
2006 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.x86_64-linux.iso
2009 Access to @file{/dev/srX} usually requires root privileges.
2012 @unnumberedsubsec Booting
2014 Once this is done, you should be able to reboot the system and boot from
2015 the USB stick or DVD. The latter usually requires you to get in the
2016 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
2017 In order to boot from Libreboot, switch to the command mode by pressing
2018 the @kbd{c} key and type @command{search_grub usb}.
2020 @xref{Installing Guix in a VM}, if, instead, you would like to install
2021 Guix System in a virtual machine (VM).
2024 @node Preparing for Installation
2025 @section Preparing for Installation
2027 Once you have booted, you can use the guided graphical installer, which makes
2028 it easy to get started (@pxref{Guided Graphical Installation}). Alternatively,
2029 if you are already familiar with GNU/Linux and if you want more control than
2030 what the graphical installer provides, you can choose the ``manual''
2031 installation process (@pxref{Manual Installation}).
2033 The graphical installer is available on TTY1. You can obtain root shells on
2034 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
2035 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
2036 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
2037 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2038 which allows you to select text with the left mouse button and to paste it
2039 with the middle button.
2042 Installation requires access to the Internet so that any missing
2043 dependencies of your system configuration can be downloaded. See the
2044 ``Networking'' section below.
2047 @node Guided Graphical Installation
2048 @section Guided Graphical Installation
2050 The graphical installer is a text-based user interface. It will guide you,
2051 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2053 The first dialog boxes allow you to set up the system as you use it during the
2054 installation: you can choose the language, keyboard layout, and set up
2055 networking, which will be used during the installation. The image below shows
2056 the networking dialog.
2058 @image{images/installer-network,5in,, networking setup with the graphical installer}
2060 Later steps allow you to partition your hard disk, as shown in the image
2061 below, to choose whether or not to use encrypted file systems, to enter the
2062 host name and root password, and to create an additional account, among other
2065 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2067 Note that, at any time, the installer allows you to exit the current
2068 installation step and resume at a previous step, as show in the image below.
2070 @image{images/installer-resume,5in,, resuming the installation process}
2072 Once you're done, the installer produces an operating system configuration and
2073 displays it (@pxref{Using the Configuration System}). At that point you can
2074 hit ``OK'' and installation will proceed. On success, you can reboot into the
2075 new system and enjoy. @xref{After System Installation}, for what's next!
2078 @node Manual Installation
2079 @section Manual Installation
2081 This section describes how you would ``manually'' install GNU@tie{}Guix System
2082 on your machine. This option requires familiarity with GNU/Linux, with the
2083 shell, and with common administration tools. If you think this is not for
2084 you, consider using the guided graphical installer (@pxref{Guided Graphical
2087 The installation system provides root shells on TTYs 3 to 6; press
2088 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2089 many common tools needed to install the system. But it is also a full-blown
2090 Guix System, which means that you can install additional packages, should you
2091 need it, using @command{guix package} (@pxref{Invoking guix package}).
2094 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2095 * Proceeding with the Installation:: Installing.
2098 @node Keyboard Layout and Networking and Partitioning
2099 @subsection Keyboard Layout, Networking, and Partitioning
2101 Before you can install the system, you may want to adjust the keyboard layout,
2102 set up networking, and partition your target hard disk. This section will
2103 guide you through this.
2105 @subsubsection Keyboard Layout
2107 @cindex keyboard layout
2108 The installation image uses the US qwerty keyboard layout. If you want
2109 to change it, you can use the @command{loadkeys} command. For example,
2110 the following command selects the Dvorak keyboard layout:
2116 See the files under @file{/run/current-system/profile/share/keymaps} for
2117 a list of available keyboard layouts. Run @command{man loadkeys} for
2120 @subsubsection Networking
2122 Run the following command to see what your network interfaces are called:
2129 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2135 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2136 Wired interfaces have a name starting with @samp{e}; for example, the
2137 interface corresponding to the first on-board Ethernet controller is
2138 called @samp{eno1}. Wireless interfaces have a name starting with
2139 @samp{w}, like @samp{w1p2s0}.
2142 @item Wired connection
2143 To configure a wired network run the following command, substituting
2144 @var{interface} with the name of the wired interface you want to use.
2147 ifconfig @var{interface} up
2151 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2154 ip link set @var{interface} up
2157 @item Wireless connection
2160 To configure wireless networking, you can create a configuration file
2161 for the @command{wpa_supplicant} configuration tool (its location is not
2162 important) using one of the available text editors such as
2166 nano wpa_supplicant.conf
2169 As an example, the following stanza can go to this file and will work
2170 for many wireless networks, provided you give the actual SSID and
2171 passphrase for the network you are connecting to:
2175 ssid="@var{my-ssid}"
2177 psk="the network's secret passphrase"
2181 Start the wireless service and run it in the background with the
2182 following command (substitute @var{interface} with the name of the
2183 network interface you want to use):
2186 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2189 Run @command{man wpa_supplicant} for more information.
2193 At this point, you need to acquire an IP address. On a network where IP
2194 addresses are automatically assigned @i{via} DHCP, you can run:
2197 dhclient -v @var{interface}
2200 Try to ping a server to see if networking is up and running:
2206 Setting up network access is almost always a requirement because the
2207 image does not contain all the software and tools that may be needed.
2209 @cindex proxy, during system installation
2210 If you need HTTP and HTTPS access to go through a proxy, run the
2214 herd set-http-proxy guix-daemon @var{URL}
2218 where @var{URL} is the proxy URL, for example
2219 @code{http://example.org:8118}.
2221 @cindex installing over SSH
2222 If you want to, you can continue the installation remotely by starting
2226 herd start ssh-daemon
2229 Make sure to either set a password with @command{passwd}, or configure
2230 OpenSSH public key authentication before logging in.
2232 @subsubsection Disk Partitioning
2234 Unless this has already been done, the next step is to partition, and
2235 then format the target partition(s).
2237 The installation image includes several partitioning tools, including
2238 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2239 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2240 the partition layout you want:
2246 If your disk uses the GUID Partition Table (GPT) format and you plan to
2247 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2248 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2251 @cindex EFI, installation
2252 @cindex UEFI, installation
2253 @cindex ESP, EFI system partition
2254 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2255 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2256 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2259 parted /dev/sda set 1 esp on
2263 @vindex grub-bootloader
2264 @vindex grub-efi-bootloader
2265 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2266 @file{/sys/firmware/efi} exists in the installation image, then you should
2267 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2268 Otherwise you should use the BIOS-based GRUB, known as
2269 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2273 Once you are done partitioning the target hard disk drive, you have to
2274 create a file system on the relevant partition(s)@footnote{Currently
2275 Guix System only supports ext4, btrfs, and JFS file systems. In particular,
2276 code that reads file system UUIDs and labels only works for these file system
2277 types.}. For the ESP, if you have one and assuming it is
2278 @file{/dev/sda1}, run:
2281 mkfs.fat -F32 /dev/sda1
2284 For the root file system, ext4 is the most widely used format. Other
2285 file systems, such as Btrfs, support compression, which is reported to
2286 nicely complement file deduplication that the daemon performs
2287 independently of the file system (@pxref{Invoking guix-daemon,
2290 Preferably, assign file systems a label so that you can easily and
2291 reliably refer to them in @code{file-system} declarations (@pxref{File
2292 Systems}). This is typically done using the @code{-L} option of
2293 @command{mkfs.ext4} and related commands. So, assuming the target root
2294 partition lives at @file{/dev/sda2}, a file system with the label
2295 @code{my-root} can be created with:
2298 mkfs.ext4 -L my-root /dev/sda2
2301 @cindex encrypted disk
2302 If you are instead planning to encrypt the root partition, you can use
2303 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2304 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2305 @code{man cryptsetup}} for more information). Assuming you want to
2306 store the root partition on @file{/dev/sda2}, the command sequence would
2307 be along these lines:
2310 cryptsetup luksFormat /dev/sda2
2311 cryptsetup open --type luks /dev/sda2 my-partition
2312 mkfs.ext4 -L my-root /dev/mapper/my-partition
2315 Once that is done, mount the target file system under @file{/mnt}
2316 with a command like (again, assuming @code{my-root} is the label of the
2320 mount LABEL=my-root /mnt
2323 Also mount any other file systems you would like to use on the target
2324 system relative to this path. If you have opted for @file{/boot/efi} as an
2325 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2326 found by @code{guix system init} afterwards.
2328 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2329 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2330 sure to initialize them with @command{mkswap}. Assuming you have one
2331 swap partition on @file{/dev/sda3}, you would run:
2338 Alternatively, you may use a swap file. For example, assuming that in
2339 the new system you want to use the file @file{/swapfile} as a swap file,
2340 you would run@footnote{This example will work for many types of file
2341 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2342 btrfs), the required steps may be different. For details, see the
2343 manual pages for @command{mkswap} and @command{swapon}.}:
2346 # This is 10 GiB of swap space. Adjust "count" to change the size.
2347 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2348 # For security, make the file readable and writable only by root.
2349 chmod 600 /mnt/swapfile
2350 mkswap /mnt/swapfile
2351 swapon /mnt/swapfile
2354 Note that if you have encrypted the root partition and created a swap
2355 file in its file system as described above, then the encryption also
2356 protects the swap file, just like any other file in that file system.
2358 @node Proceeding with the Installation
2359 @subsection Proceeding with the Installation
2361 With the target partitions ready and the target root mounted on
2362 @file{/mnt}, we're ready to go. First, run:
2365 herd start cow-store /mnt
2368 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2369 during the installation phase are written to the target disk on @file{/mnt}
2370 rather than kept in memory. This is necessary because the first phase of
2371 the @command{guix system init} command (see below) entails downloads or
2372 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2374 Next, you have to edit a file and
2375 provide the declaration of the operating system to be installed. To
2376 that end, the installation system comes with three text editors. We
2377 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2378 supports syntax highlighting and parentheses matching; other editors
2379 include GNU Zile (an Emacs clone), and
2380 nvi (a clone of the original BSD @command{vi} editor).
2381 We strongly recommend storing that file on the target root file system, say,
2382 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2383 configuration file once you have rebooted into the newly-installed system.
2385 @xref{Using the Configuration System}, for an overview of the
2386 configuration file. The example configurations discussed in that
2387 section are available under @file{/etc/configuration} in the
2388 installation image. Thus, to get started with a system configuration
2389 providing a graphical display server (a ``desktop'' system), you can run
2390 something along these lines:
2394 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2395 # nano /mnt/etc/config.scm
2398 You should pay attention to what your configuration file contains, and
2403 Make sure the @code{bootloader-configuration} form refers to the target
2404 you want to install GRUB on. It should mention @code{grub-bootloader} if
2405 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2406 for newer UEFI systems. For legacy systems, the @code{target} field
2407 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2408 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2409 currently mounted and a @code{file-system} entry is specified in your
2413 Be sure that your file system labels match the value of their respective
2414 @code{device} fields in your @code{file-system} configuration, assuming
2415 your @code{file-system} configuration uses the @code{file-system-label}
2416 procedure in its @code{device} field.
2419 If there are encrypted or RAID partitions, make sure to add a
2420 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2423 Once you are done preparing the configuration file, the new system must
2424 be initialized (remember that the target root file system is mounted
2428 guix system init /mnt/etc/config.scm /mnt
2432 This copies all the necessary files and installs GRUB on
2433 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2434 more information, @pxref{Invoking guix system}. This command may trigger
2435 downloads or builds of missing packages, which can take some time.
2437 Once that command has completed---and hopefully succeeded!---you can run
2438 @command{reboot} and boot into the new system. The @code{root} password
2439 in the new system is initially empty; other users' passwords need to be
2440 initialized by running the @command{passwd} command as @code{root},
2441 unless your configuration specifies otherwise
2442 (@pxref{user-account-password, user account passwords}).
2443 @xref{After System Installation}, for what's next!
2446 @node After System Installation
2447 @section After System Installation
2449 Success, you've now booted into Guix System! From then on, you can update the
2450 system whenever you want by running, say:
2454 sudo guix system reconfigure /etc/config.scm
2458 This builds a new system generation with the latest packages and services
2459 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2460 your system includes the latest security updates (@pxref{Security Updates}).
2462 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2464 @cindex sudo vs. @command{guix pull}
2465 Note that @command{sudo guix} runs your user's @command{guix} command and
2466 @emph{not} root's, because @command{sudo} leaves @env{PATH} unchanged. To
2467 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2469 The difference matters here, because @command{guix pull} updates
2470 the @command{guix} command and package definitions only for the user it is ran
2471 as. This means that if you choose to use @command{guix system reconfigure} in
2472 root's login shell, you'll need to @command{guix pull} separately.
2475 Join us on @code{#guix} on the Freenode IRC network or on
2476 @email{guix-devel@@gnu.org} to share your experience!
2479 @node Installing Guix in a VM
2480 @section Installing Guix in a Virtual Machine
2482 @cindex virtual machine, Guix System installation
2483 @cindex virtual private server (VPS)
2484 @cindex VPS (virtual private server)
2485 If you'd like to install Guix System in a virtual machine (VM) or on a
2486 virtual private server (VPS) rather than on your beloved machine, this
2489 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2490 disk image, follow these steps:
2494 First, retrieve and decompress the Guix system installation image as
2495 described previously (@pxref{USB Stick and DVD Installation}).
2498 Create a disk image that will hold the installed system. To make a
2499 qcow2-formatted disk image, use the @command{qemu-img} command:
2502 qemu-img create -f qcow2 guix-system.img 50G
2505 The resulting file will be much smaller than 50 GB (typically less than
2506 1 MB), but it will grow as the virtualized storage device is filled up.
2509 Boot the USB installation image in an VM:
2512 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2513 -nic user,model=virtio-net-pci -boot menu=on,order=d \
2514 -drive file=guix-system.img \
2515 -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
2518 @code{-enable-kvm} is optional, but significantly improves performance,
2519 @pxref{Running Guix in a VM}.
2522 You're now root in the VM, proceed with the installation process.
2523 @xref{Preparing for Installation}, and follow the instructions.
2526 Once installation is complete, you can boot the system that's on your
2527 @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
2530 @node Building the Installation Image
2531 @section Building the Installation Image
2533 @cindex installation image
2534 The installation image described above was built using the @command{guix
2535 system} command, specifically:
2538 guix system disk-image --file-system-type=iso9660 \
2539 gnu/system/install.scm
2542 Have a look at @file{gnu/system/install.scm} in the source tree,
2543 and see also @ref{Invoking guix system} for more information
2544 about the installation image.
2546 @section Building the Installation Image for ARM Boards
2548 Many ARM boards require a specific variant of the
2549 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2551 If you build a disk image and the bootloader is not available otherwise
2552 (on another boot drive etc), it's advisable to build an image that
2553 includes the bootloader, specifically:
2556 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2559 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2560 board, a list of possible boards will be printed.
2562 @c *********************************************************************
2563 @node Package Management
2564 @chapter Package Management
2567 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2568 remove software packages, without having to know about their build
2569 procedures or dependencies. Guix also goes beyond this obvious set of
2572 This chapter describes the main features of Guix, as well as the
2573 package management tools it provides. Along with the command-line
2574 interface described below (@pxref{Invoking guix package, @code{guix
2575 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2576 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2577 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2581 guix install emacs-guix
2585 * Features:: How Guix will make your life brighter.
2586 * Invoking guix package:: Package installation, removal, etc.
2587 * Substitutes:: Downloading pre-built binaries.
2588 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2589 * Invoking guix gc:: Running the garbage collector.
2590 * Invoking guix pull:: Fetching the latest Guix and distribution.
2591 * Channels:: Customizing the package collection.
2592 * Invoking guix time-machine:: Running an older revision of Guix.
2593 * Inferiors:: Interacting with another revision of Guix.
2594 * Invoking guix describe:: Display information about your Guix revision.
2595 * Invoking guix archive:: Exporting and importing store files.
2601 When using Guix, each package ends up in the @dfn{package store}, in its
2602 own directory---something that resembles
2603 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2605 Instead of referring to these directories, users have their own
2606 @dfn{profile}, which points to the packages that they actually want to
2607 use. These profiles are stored within each user's home directory, at
2608 @code{$HOME/.guix-profile}.
2610 For example, @code{alice} installs GCC 4.7.2. As a result,
2611 @file{/home/alice/.guix-profile/bin/gcc} points to
2612 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2613 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2614 simply continues to point to
2615 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2616 coexist on the same system without any interference.
2618 The @command{guix package} command is the central tool to manage
2619 packages (@pxref{Invoking guix package}). It operates on the per-user
2620 profiles, and can be used @emph{with normal user privileges}.
2622 @cindex transactions
2623 The command provides the obvious install, remove, and upgrade
2624 operations. Each invocation is actually a @emph{transaction}: either
2625 the specified operation succeeds, or nothing happens. Thus, if the
2626 @command{guix package} process is terminated during the transaction,
2627 or if a power outage occurs during the transaction, then the user's
2628 profile remains in its previous state, and remains usable.
2630 In addition, any package transaction may be @emph{rolled back}. So, if,
2631 for example, an upgrade installs a new version of a package that turns
2632 out to have a serious bug, users may roll back to the previous instance
2633 of their profile, which was known to work well. Similarly, the global
2634 system configuration on Guix is subject to
2635 transactional upgrades and roll-back
2636 (@pxref{Using the Configuration System}).
2638 All packages in the package store may be @emph{garbage-collected}.
2639 Guix can determine which packages are still referenced by user
2640 profiles, and remove those that are provably no longer referenced
2641 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2642 generations of their profile so that the packages they refer to can be
2645 @cindex reproducibility
2646 @cindex reproducible builds
2647 Guix takes a @dfn{purely functional} approach to package
2648 management, as described in the introduction (@pxref{Introduction}).
2649 Each @file{/gnu/store} package directory name contains a hash of all the
2650 inputs that were used to build that package---compiler, libraries, build
2651 scripts, etc. This direct correspondence allows users to make sure a
2652 given package installation matches the current state of their
2653 distribution. It also helps maximize @dfn{build reproducibility}:
2654 thanks to the isolated build environments that are used, a given build
2655 is likely to yield bit-identical files when performed on different
2656 machines (@pxref{Invoking guix-daemon, container}).
2659 This foundation allows Guix to support @dfn{transparent binary/source
2660 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2661 available from an external source---a @dfn{substitute}, Guix just
2662 downloads it and unpacks it;
2663 otherwise, it builds the package from source, locally
2664 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2665 reproducible, users do not have to trust servers that provide
2666 substitutes: they can force a local build and @emph{challenge} providers
2667 (@pxref{Invoking guix challenge}).
2669 Control over the build environment is a feature that is also useful for
2670 developers. The @command{guix environment} command allows developers of
2671 a package to quickly set up the right development environment for their
2672 package, without having to manually install the dependencies of the
2673 package into their profile (@pxref{Invoking guix environment}).
2675 @cindex replication, of software environments
2676 @cindex provenance tracking, of software artifacts
2677 All of Guix and its package definitions is version-controlled, and
2678 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2679 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2680 Guix instance on a different machine or at a later point in time, which in
2681 turn allows you to @emph{replicate complete software environments}, while
2682 retaining precise @dfn{provenance tracking} of the software.
2684 @node Invoking guix package
2685 @section Invoking @command{guix package}
2687 @cindex installing packages
2688 @cindex removing packages
2689 @cindex package installation
2690 @cindex package removal
2691 The @command{guix package} command is the tool that allows users to
2692 install, upgrade, and remove packages, as well as rolling back to
2693 previous configurations. It operates only on the user's own profile,
2694 and works with normal user privileges (@pxref{Features}). Its syntax
2698 guix package @var{options}
2701 @cindex transactions
2702 Primarily, @var{options} specifies the operations to be performed during
2703 the transaction. Upon completion, a new profile is created, but
2704 previous @dfn{generations} of the profile remain available, should the user
2707 For example, to remove @code{lua} and install @code{guile} and
2708 @code{guile-cairo} in a single transaction:
2711 guix package -r lua -i guile guile-cairo
2714 @cindex aliases, for @command{guix package}
2715 For your convenience, we also provide the following aliases:
2719 @command{guix search} is an alias for @command{guix package -s},
2721 @command{guix install} is an alias for @command{guix package -i},
2723 @command{guix remove} is an alias for @command{guix package -r},
2725 @command{guix upgrade} is an alias for @command{guix package -u},
2727 and @command{guix show} is an alias for @command{guix package --show=}.
2730 These aliases are less expressive than @command{guix package} and provide
2731 fewer options, so in some cases you'll probably want to use @command{guix
2734 @command{guix package} also supports a @dfn{declarative approach}
2735 whereby the user specifies the exact set of packages to be available and
2736 passes it @i{via} the @option{--manifest} option
2737 (@pxref{profile-manifest, @option{--manifest}}).
2740 For each user, a symlink to the user's default profile is automatically
2741 created in @file{$HOME/.guix-profile}. This symlink always points to the
2742 current generation of the user's default profile. Thus, users can add
2743 @file{$HOME/.guix-profile/bin} to their @env{PATH} environment
2744 variable, and so on.
2745 @cindex search paths
2746 If you are not using Guix System, consider adding the
2747 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2748 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2749 shells get all the right environment variable definitions:
2752 GUIX_PROFILE="$HOME/.guix-profile" ; \
2753 source "$HOME/.guix-profile/etc/profile"
2756 In a multi-user setup, user profiles are stored in a place registered as
2757 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2758 to (@pxref{Invoking guix gc}). That directory is normally
2759 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2760 @var{localstatedir} is the value passed to @code{configure} as
2761 @option{--localstatedir}, and @var{user} is the user name. The
2762 @file{per-user} directory is created when @command{guix-daemon} is
2763 started, and the @var{user} sub-directory is created by @command{guix
2766 The @var{options} can be among the following:
2770 @item --install=@var{package} @dots{}
2771 @itemx -i @var{package} @dots{}
2772 Install the specified @var{package}s.
2774 Each @var{package} may specify either a simple package name, such as
2775 @code{guile}, or a package name followed by an at-sign and version number,
2776 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2777 case, the newest version prefixed by @code{1.8} is selected).
2779 If no version number is specified, the
2780 newest available version will be selected. In addition, @var{package}
2781 may contain a colon, followed by the name of one of the outputs of the
2782 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
2783 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
2784 name (and optionally version) are searched for among the GNU
2785 distribution modules (@pxref{Package Modules}).
2787 @cindex propagated inputs
2788 Sometimes packages have @dfn{propagated inputs}: these are dependencies
2789 that automatically get installed along with the required package
2790 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
2791 @code{package} objects}, for information about propagated inputs in
2792 package definitions).
2794 @anchor{package-cmd-propagated-inputs}
2795 An example is the GNU MPC library: its C header files refer to those of
2796 the GNU MPFR library, which in turn refer to those of the GMP library.
2797 Thus, when installing MPC, the MPFR and GMP libraries also get installed
2798 in the profile; removing MPC also removes MPFR and GMP---unless they had
2799 also been explicitly installed by the user.
2801 Besides, packages sometimes rely on the definition of environment
2802 variables for their search paths (see explanation of
2803 @option{--search-paths} below). Any missing or possibly incorrect
2804 environment variable definitions are reported here.
2806 @item --install-from-expression=@var{exp}
2808 Install the package @var{exp} evaluates to.
2810 @var{exp} must be a Scheme expression that evaluates to a
2811 @code{<package>} object. This option is notably useful to disambiguate
2812 between same-named variants of a package, with expressions such as
2813 @code{(@@ (gnu packages base) guile-final)}.
2815 Note that this option installs the first output of the specified
2816 package, which may be insufficient when needing a specific output of a
2817 multiple-output package.
2819 @item --install-from-file=@var{file}
2820 @itemx -f @var{file}
2821 Install the package that the code within @var{file} evaluates to.
2823 As an example, @var{file} might contain a definition like this
2824 (@pxref{Defining Packages}):
2827 @include package-hello.scm
2830 Developers may find it useful to include such a @file{guix.scm} file
2831 in the root of their project source tree that can be used to test
2832 development snapshots and create reproducible development environments
2833 (@pxref{Invoking guix environment}).
2835 The @var{file} may also contain a JSON representation of one or more
2836 package definitions. Running @code{guix package -f} on
2837 @file{hello.json} with the following contents would result in installing
2838 the package @code{greeter} after building @code{myhello}:
2841 @verbatiminclude package-hello.json
2844 @item --remove=@var{package} @dots{}
2845 @itemx -r @var{package} @dots{}
2846 Remove the specified @var{package}s.
2848 As for @option{--install}, each @var{package} may specify a version number
2849 and/or output name in addition to the package name. For instance,
2850 @samp{-r glibc:debug} would remove the @code{debug} output of
2853 @item --upgrade[=@var{regexp} @dots{}]
2854 @itemx -u [@var{regexp} @dots{}]
2855 @cindex upgrading packages
2856 Upgrade all the installed packages. If one or more @var{regexp}s are
2857 specified, upgrade only installed packages whose name matches a
2858 @var{regexp}. Also see the @option{--do-not-upgrade} option below.
2860 Note that this upgrades package to the latest version of packages found
2861 in the distribution currently installed. To update your distribution,
2862 you should regularly run @command{guix pull} (@pxref{Invoking guix
2865 @item --do-not-upgrade[=@var{regexp} @dots{}]
2866 When used together with the @option{--upgrade} option, do @emph{not}
2867 upgrade any packages whose name matches a @var{regexp}. For example, to
2868 upgrade all packages in the current profile except those containing the
2869 substring ``emacs'':
2872 $ guix package --upgrade . --do-not-upgrade emacs
2875 @item @anchor{profile-manifest}--manifest=@var{file}
2876 @itemx -m @var{file}
2877 @cindex profile declaration
2878 @cindex profile manifest
2879 Create a new generation of the profile from the manifest object
2880 returned by the Scheme code in @var{file}. This option can be repeated
2881 several times, in which case the manifests are concatenated.
2883 This allows you to @emph{declare} the profile's contents rather than
2884 constructing it through a sequence of @option{--install} and similar
2885 commands. The advantage is that @var{file} can be put under version
2886 control, copied to different machines to reproduce the same profile, and
2889 @c FIXME: Add reference to (guix profile) documentation when available.
2890 @var{file} must return a @dfn{manifest} object, which is roughly a list
2893 @findex packages->manifest
2895 (use-package-modules guile emacs)
2900 ;; Use a specific package output.
2901 (list guile-2.0 "debug")))
2904 @findex specifications->manifest
2905 In this example we have to know which modules define the @code{emacs}
2906 and @code{guile-2.0} variables to provide the right
2907 @code{use-package-modules} line, which can be cumbersome. We can
2908 instead provide regular package specifications and let
2909 @code{specifications->manifest} look up the corresponding package
2913 (specifications->manifest
2914 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2918 @cindex rolling back
2919 @cindex undoing transactions
2920 @cindex transactions, undoing
2921 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2922 the last transaction.
2924 When combined with options such as @option{--install}, roll back occurs
2925 before any other actions.
2927 When rolling back from the first generation that actually contains
2928 installed packages, the profile is made to point to the @dfn{zeroth
2929 generation}, which contains no files apart from its own metadata.
2931 After having rolled back, installing, removing, or upgrading packages
2932 overwrites previous future generations. Thus, the history of the
2933 generations in a profile is always linear.
2935 @item --switch-generation=@var{pattern}
2936 @itemx -S @var{pattern}
2938 Switch to a particular generation defined by @var{pattern}.
2940 @var{pattern} may be either a generation number or a number prefixed
2941 with ``+'' or ``-''. The latter means: move forward/backward by a
2942 specified number of generations. For example, if you want to return to
2943 the latest generation after @option{--roll-back}, use
2944 @option{--switch-generation=+1}.
2946 The difference between @option{--roll-back} and
2947 @option{--switch-generation=-1} is that @option{--switch-generation} will
2948 not make a zeroth generation, so if a specified generation does not
2949 exist, the current generation will not be changed.
2951 @item --search-paths[=@var{kind}]
2952 @cindex search paths
2953 Report environment variable definitions, in Bash syntax, that may be
2954 needed in order to use the set of installed packages. These environment
2955 variables are used to specify @dfn{search paths} for files used by some
2956 of the installed packages.
2958 For example, GCC needs the @env{CPATH} and @env{LIBRARY_PATH}
2959 environment variables to be defined so it can look for headers and
2960 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2961 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2962 library are installed in the profile, then @option{--search-paths} will
2963 suggest setting these variables to @file{@var{profile}/include} and
2964 @file{@var{profile}/lib}, respectively.
2966 The typical use case is to define these environment variables in the
2970 $ eval `guix package --search-paths`
2973 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2974 meaning that the returned environment variable definitions will either
2975 be exact settings, or prefixes or suffixes of the current value of these
2976 variables. When omitted, @var{kind} defaults to @code{exact}.
2978 This option can also be used to compute the @emph{combined} search paths
2979 of several profiles. Consider this example:
2982 $ guix package -p foo -i guile
2983 $ guix package -p bar -i guile-json
2984 $ guix package -p foo -p bar --search-paths
2987 The last command above reports about the @env{GUILE_LOAD_PATH}
2988 variable, even though, taken individually, neither @file{foo} nor
2989 @file{bar} would lead to that recommendation.
2992 @item --profile=@var{profile}
2993 @itemx -p @var{profile}
2994 Use @var{profile} instead of the user's default profile.
2996 @var{profile} must be the name of a file that will be created upon
2997 completion. Concretely, @var{profile} will be a mere symbolic link
2998 (``symlink'') pointing to the actual profile where packages are
3002 $ guix install hello -p ~/code/my-profile
3004 $ ~/code/my-profile/bin/hello
3008 All it takes to get rid of the profile is to remove this symlink and its
3009 siblings that point to specific generations:
3012 $ rm ~/code/my-profile ~/code/my-profile-*-link
3015 @item --list-profiles
3016 List all the user's profiles:
3019 $ guix package --list-profiles
3020 /home/charlie/.guix-profile
3021 /home/charlie/code/my-profile
3022 /home/charlie/code/devel-profile
3023 /home/charlie/tmp/test
3026 When running as root, list all the profiles of all the users.
3028 @cindex collisions, in a profile
3029 @cindex colliding packages in profiles
3030 @cindex profile collisions
3031 @item --allow-collisions
3032 Allow colliding packages in the new profile. Use at your own risk!
3034 By default, @command{guix package} reports as an error @dfn{collisions}
3035 in the profile. Collisions happen when two or more different versions
3036 or variants of a given package end up in the profile.
3039 Use the bootstrap Guile to build the profile. This option is only
3040 useful to distribution developers.
3044 In addition to these actions, @command{guix package} supports the
3045 following options to query the current state of a profile, or the
3046 availability of packages:
3050 @item --search=@var{regexp}
3051 @itemx -s @var{regexp}
3052 @anchor{guix-search}
3053 @cindex searching for packages
3054 List the available packages whose name, synopsis, or description matches
3055 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
3056 Print all the metadata of matching packages in
3057 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
3058 GNU recutils manual}).
3060 This allows specific fields to be extracted using the @command{recsel}
3061 command, for instance:
3064 $ guix package -s malloc | recsel -p name,version,relevance
3078 Similarly, to show the name of all the packages available under the
3079 terms of the GNU@tie{}LGPL version 3:
3082 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
3089 It is also possible to refine search results using several @code{-s} flags to
3090 @command{guix package}, or several arguments to @command{guix search}. For
3091 example, the following command returns a list of board games (this time using
3092 the @command{guix search} alias):
3095 $ guix search '\<board\>' game | recsel -p name
3100 If we were to omit @code{-s game}, we would also get software packages
3101 that deal with printed circuit boards; removing the angle brackets
3102 around @code{board} would further add packages that have to do with
3105 And now for a more elaborate example. The following command searches
3106 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
3107 libraries, and prints the name and synopsis of the matching packages:
3110 $ guix search crypto library | \
3111 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3115 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3116 information on @dfn{selection expressions} for @code{recsel -e}.
3118 @item --show=@var{package}
3119 Show details about @var{package}, taken from the list of available packages, in
3120 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3124 $ guix package --show=python | recsel -p name,version
3132 You may also specify the full name of a package to only get details about a
3133 specific version of it (this time using the @command{guix show} alias):
3135 $ guix show python@@3.4 | recsel -p name,version
3142 @item --list-installed[=@var{regexp}]
3143 @itemx -I [@var{regexp}]
3144 List the currently installed packages in the specified profile, with the
3145 most recently installed packages shown last. When @var{regexp} is
3146 specified, list only installed packages whose name matches @var{regexp}.
3148 For each installed package, print the following items, separated by
3149 tabs: the package name, its version string, the part of the package that
3150 is installed (for instance, @code{out} for the default output,
3151 @code{include} for its headers, etc.), and the path of this package in
3154 @item --list-available[=@var{regexp}]
3155 @itemx -A [@var{regexp}]
3156 List packages currently available in the distribution for this system
3157 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3158 available packages whose name matches @var{regexp}.
3160 For each package, print the following items separated by tabs: its name,
3161 its version string, the parts of the package (@pxref{Packages with
3162 Multiple Outputs}), and the source location of its definition.
3164 @item --list-generations[=@var{pattern}]
3165 @itemx -l [@var{pattern}]
3167 Return a list of generations along with their creation dates; for each
3168 generation, show the installed packages, with the most recently
3169 installed packages shown last. Note that the zeroth generation is never
3172 For each installed package, print the following items, separated by
3173 tabs: the name of a package, its version string, the part of the package
3174 that is installed (@pxref{Packages with Multiple Outputs}), and the
3175 location of this package in the store.
3177 When @var{pattern} is used, the command returns only matching
3178 generations. Valid patterns include:
3181 @item @emph{Integers and comma-separated integers}. Both patterns denote
3182 generation numbers. For instance, @option{--list-generations=1} returns
3185 And @option{--list-generations=1,8,2} outputs three generations in the
3186 specified order. Neither spaces nor trailing commas are allowed.
3188 @item @emph{Ranges}. @option{--list-generations=2..9} prints the
3189 specified generations and everything in between. Note that the start of
3190 a range must be smaller than its end.
3192 It is also possible to omit the endpoint. For example,
3193 @option{--list-generations=2..}, returns all generations starting from the
3196 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3197 or months by passing an integer along with the first letter of the
3198 duration. For example, @option{--list-generations=20d} lists generations
3199 that are up to 20 days old.
3202 @item --delete-generations[=@var{pattern}]
3203 @itemx -d [@var{pattern}]
3204 When @var{pattern} is omitted, delete all generations except the current
3207 This command accepts the same patterns as @option{--list-generations}.
3208 When @var{pattern} is specified, delete the matching generations. When
3209 @var{pattern} specifies a duration, generations @emph{older} than the
3210 specified duration match. For instance, @option{--delete-generations=1m}
3211 deletes generations that are more than one month old.
3213 If the current generation matches, it is @emph{not} deleted. Also, the
3214 zeroth generation is never deleted.
3216 Note that deleting generations prevents rolling back to them.
3217 Consequently, this command must be used with care.
3221 Finally, since @command{guix package} may actually start build
3222 processes, it supports all the common build options (@pxref{Common Build
3223 Options}). It also supports package transformation options, such as
3224 @option{--with-source} (@pxref{Package Transformation Options}).
3225 However, note that package transformations are lost when upgrading; to
3226 preserve transformations across upgrades, you should define your own
3227 package variant in a Guile module and add it to @env{GUIX_PACKAGE_PATH}
3228 (@pxref{Defining Packages}).
3231 @section Substitutes
3234 @cindex pre-built binaries
3235 Guix supports transparent source/binary deployment, which means that it
3236 can either build things locally, or download pre-built items from a
3237 server, or both. We call these pre-built items @dfn{substitutes}---they
3238 are substitutes for local build results. In many cases, downloading a
3239 substitute is much faster than building things locally.
3241 Substitutes can be anything resulting from a derivation build
3242 (@pxref{Derivations}). Of course, in the common case, they are
3243 pre-built package binaries, but source tarballs, for instance, which
3244 also result from derivation builds, can be available as substitutes.
3247 * Official Substitute Server:: One particular source of substitutes.
3248 * Substitute Server Authorization:: How to enable or disable substitutes.
3249 * Substitute Authentication:: How Guix verifies substitutes.
3250 * Proxy Settings:: How to get substitutes via proxy.
3251 * Substitution Failure:: What happens when substitution fails.
3252 * On Trusting Binaries:: How can you trust that binary blob?
3255 @node Official Substitute Server
3256 @subsection Official Substitute Server
3259 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3260 that builds packages from Guix continuously for some
3261 architectures, and makes them available as substitutes. This is the
3262 default source of substitutes; it can be overridden by passing the
3263 @option{--substitute-urls} option either to @command{guix-daemon}
3264 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3265 or to client tools such as @command{guix package}
3266 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3269 Substitute URLs can be either HTTP or HTTPS.
3270 HTTPS is recommended because communications are encrypted; conversely,
3271 using HTTP makes all communications visible to an eavesdropper, who
3272 could use the information gathered to determine, for instance, whether
3273 your system has unpatched security vulnerabilities.
3275 Substitutes from the official build farm are enabled by default when
3276 using Guix System (@pxref{GNU Distribution}). However,
3277 they are disabled by default when using Guix on a foreign distribution,
3278 unless you have explicitly enabled them via one of the recommended
3279 installation steps (@pxref{Installation}). The following paragraphs
3280 describe how to enable or disable substitutes for the official build
3281 farm; the same procedure can also be used to enable substitutes for any
3282 other substitute server.
3284 @node Substitute Server Authorization
3285 @subsection Substitute Server Authorization
3288 @cindex substitutes, authorization thereof
3289 @cindex access control list (ACL), for substitutes
3290 @cindex ACL (access control list), for substitutes
3291 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3293 must add its public key to the access control list (ACL) of archive
3294 imports, using the @command{guix archive} command (@pxref{Invoking guix
3295 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3296 be compromised and to serve genuine substitutes.
3298 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3299 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3300 the installation prefix of Guix. If you installed Guix from source,
3301 make sure you checked the GPG signature of
3302 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3303 Then, you can run something like this:
3306 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3309 Once this is in place, the output of a command like @code{guix build}
3310 should change from something like:
3313 $ guix build emacs --dry-run
3314 The following derivations would be built:
3315 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3316 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3317 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3318 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3326 $ guix build emacs --dry-run
3327 112.3 MB would be downloaded:
3328 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3329 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3330 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3331 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3336 The text changed from ``The following derivations would be built'' to
3337 ``112.3 MB would be downloaded''. This indicates that substitutes from
3338 @code{@value{SUBSTITUTE-SERVER}} are usable and will be downloaded, when
3339 possible, for future builds.
3341 @cindex substitutes, how to disable
3342 The substitute mechanism can be disabled globally by running
3343 @code{guix-daemon} with @option{--no-substitutes} (@pxref{Invoking
3344 guix-daemon}). It can also be disabled temporarily by passing the
3345 @option{--no-substitutes} option to @command{guix package},
3346 @command{guix build}, and other command-line tools.
3348 @node Substitute Authentication
3349 @subsection Substitute Authentication
3351 @cindex digital signatures
3352 Guix detects and raises an error when attempting to use a substitute
3353 that has been tampered with. Likewise, it ignores substitutes that are
3354 not signed, or that are not signed by one of the keys listed in the ACL.
3356 There is one exception though: if an unauthorized server provides
3357 substitutes that are @emph{bit-for-bit identical} to those provided by
3358 an authorized server, then the unauthorized server becomes eligible for
3359 downloads. For example, assume we have chosen two substitute servers
3363 --substitute-urls="https://a.example.org https://b.example.org"
3367 @cindex reproducible builds
3368 If the ACL contains only the key for @samp{b.example.org}, and if
3369 @samp{a.example.org} happens to serve the @emph{exact same} substitutes,
3370 then Guix will download substitutes from @samp{a.example.org} because it
3371 comes first in the list and can be considered a mirror of
3372 @samp{b.example.org}. In practice, independent build machines usually
3373 produce the same binaries, thanks to bit-reproducible builds (see
3376 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3377 (in other words, the server is not authenticated), contrary to what
3378 HTTPS clients such as Web browsers usually do. This is because Guix
3379 authenticates substitute information itself, as explained above, which
3380 is what we care about (whereas X.509 certificates are about
3381 authenticating bindings between domain names and public keys).
3383 @node Proxy Settings
3384 @subsection Proxy Settings
3388 Substitutes are downloaded over HTTP or HTTPS. The @env{http_proxy} and
3389 @env{https_proxy} environment variables can be set in the environment of
3390 @command{guix-daemon} and are honored for downloads of substitutes.
3391 Note that the value of those environment variables in the environment
3392 where @command{guix build}, @command{guix package}, and other client
3393 commands are run has @emph{absolutely no effect}.
3395 @node Substitution Failure
3396 @subsection Substitution Failure
3398 Even when a substitute for a derivation is available, sometimes the
3399 substitution attempt will fail. This can happen for a variety of
3400 reasons: the substitute server might be offline, the substitute may
3401 recently have been deleted, the connection might have been interrupted,
3404 When substitutes are enabled and a substitute for a derivation is
3405 available, but the substitution attempt fails, Guix will attempt to
3406 build the derivation locally depending on whether or not
3407 @option{--fallback} was given (@pxref{fallback-option,, common build
3408 option @option{--fallback}}). Specifically, if @option{--fallback} was
3409 omitted, then no local build will be performed, and the derivation is
3410 considered to have failed. However, if @option{--fallback} was given,
3411 then Guix will attempt to build the derivation locally, and the success
3412 or failure of the derivation depends on the success or failure of the
3413 local build. Note that when substitutes are disabled or no substitute
3414 is available for the derivation in question, a local build will
3415 @emph{always} be performed, regardless of whether or not
3416 @option{--fallback} was given.
3418 To get an idea of how many substitutes are available right now, you can
3419 try running the @command{guix weather} command (@pxref{Invoking guix
3420 weather}). This command provides statistics on the substitutes provided
3423 @node On Trusting Binaries
3424 @subsection On Trusting Binaries
3426 @cindex trust, of pre-built binaries
3427 Today, each individual's control over their own computing is at the
3428 mercy of institutions, corporations, and groups with enough power and
3429 determination to subvert the computing infrastructure and exploit its
3430 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3431 convenient, we encourage users to also build on their own, or even run
3432 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3433 interesting target. One way to help is by publishing the software you
3434 build using @command{guix publish} so that others have one more choice
3435 of server to download substitutes from (@pxref{Invoking guix publish}).
3437 Guix has the foundations to maximize build reproducibility
3438 (@pxref{Features}). In most cases, independent builds of a given
3439 package or derivation should yield bit-identical results. Thus, through
3440 a diverse set of independent package builds, we can strengthen the
3441 integrity of our systems. The @command{guix challenge} command aims to
3442 help users assess substitute servers, and to assist developers in
3443 finding out about non-deterministic package builds (@pxref{Invoking guix
3444 challenge}). Similarly, the @option{--check} option of @command{guix
3445 build} allows users to check whether previously-installed substitutes
3446 are genuine by rebuilding them locally (@pxref{build-check,
3447 @command{guix build --check}}).
3449 In the future, we want Guix to have support to publish and retrieve
3450 binaries to/from other users, in a peer-to-peer fashion. If you would
3451 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3453 @node Packages with Multiple Outputs
3454 @section Packages with Multiple Outputs
3456 @cindex multiple-output packages
3457 @cindex package outputs
3460 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3461 source package leads to exactly one directory in the store. When running
3462 @command{guix install glibc}, one installs the default output of the
3463 GNU libc package; the default output is called @code{out}, but its name
3464 can be omitted as shown in this command. In this particular case, the
3465 default output of @code{glibc} contains all the C header files, shared
3466 libraries, static libraries, Info documentation, and other supporting
3469 Sometimes it is more appropriate to separate the various types of files
3470 produced from a single source package into separate outputs. For
3471 instance, the GLib C library (used by GTK+ and related packages)
3472 installs more than 20 MiB of reference documentation as HTML pages.
3473 To save space for users who do not need it, the documentation goes to a
3474 separate output, called @code{doc}. To install the main GLib output,
3475 which contains everything but the documentation, one would run:
3481 @cindex documentation
3482 The command to install its documentation is:
3485 guix install glib:doc
3488 Some packages install programs with different ``dependency footprints''.
3489 For instance, the WordNet package installs both command-line tools and
3490 graphical user interfaces (GUIs). The former depend solely on the C
3491 library, whereas the latter depend on Tcl/Tk and the underlying X
3492 libraries. In this case, we leave the command-line tools in the default
3493 output, whereas the GUIs are in a separate output. This allows users
3494 who do not need the GUIs to save space. The @command{guix size} command
3495 can help find out about such situations (@pxref{Invoking guix size}).
3496 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3498 There are several such multiple-output packages in the GNU distribution.
3499 Other conventional output names include @code{lib} for libraries and
3500 possibly header files, @code{bin} for stand-alone programs, and
3501 @code{debug} for debugging information (@pxref{Installing Debugging
3502 Files}). The outputs of a packages are listed in the third column of
3503 the output of @command{guix package --list-available} (@pxref{Invoking
3507 @node Invoking guix gc
3508 @section Invoking @command{guix gc}
3510 @cindex garbage collector
3512 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3513 The @command{guix gc} command allows users to explicitly run the garbage
3514 collector to reclaim space from the @file{/gnu/store} directory. It is
3515 the @emph{only} way to remove files from @file{/gnu/store}---removing
3516 files or directories manually may break it beyond repair!
3519 @cindex garbage collector roots
3520 The garbage collector has a set of known @dfn{roots}: any file under
3521 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3522 cannot be deleted; any other file is considered @dfn{dead} and may be
3523 deleted. The set of garbage collector roots (``GC roots'' for short)
3524 includes default user profiles; by default, the symlinks under
3525 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3526 added with @command{guix build --root}, for example (@pxref{Invoking
3527 guix build}). The @command{guix gc --list-roots} command lists them.
3529 Prior to running @code{guix gc --collect-garbage} to make space, it is
3530 often useful to remove old generations from user profiles; that way, old
3531 package builds referenced by those generations can be reclaimed. This
3532 is achieved by running @code{guix package --delete-generations}
3533 (@pxref{Invoking guix package}).
3535 Our recommendation is to run a garbage collection periodically, or when
3536 you are short on disk space. For instance, to guarantee that at least
3537 5@tie{}GB are available on your disk, simply run:
3543 It is perfectly safe to run as a non-interactive periodic job
3544 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3545 Running @command{guix gc} with no arguments will collect as
3546 much garbage as it can, but that is often inconvenient: you may find
3547 yourself having to rebuild or re-download software that is ``dead'' from
3548 the GC viewpoint but that is necessary to build other pieces of
3549 software---e.g., the compiler tool chain.
3551 The @command{guix gc} command has three modes of operation: it can be
3552 used to garbage-collect any dead files (the default), to delete specific
3553 files (the @option{--delete} option), to print garbage-collector
3554 information, or for more advanced queries. The garbage collection
3555 options are as follows:
3558 @item --collect-garbage[=@var{min}]
3559 @itemx -C [@var{min}]
3560 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3561 sub-directories. This is the default operation when no option is
3564 When @var{min} is given, stop once @var{min} bytes have been collected.
3565 @var{min} may be a number of bytes, or it may include a unit as a
3566 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3567 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3569 When @var{min} is omitted, collect all the garbage.
3571 @item --free-space=@var{free}
3572 @itemx -F @var{free}
3573 Collect garbage until @var{free} space is available under
3574 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3575 as @code{500MiB}, as described above.
3577 When @var{free} or more is already available in @file{/gnu/store}, do
3578 nothing and exit immediately.
3580 @item --delete-generations[=@var{duration}]
3581 @itemx -d [@var{duration}]
3582 Before starting the garbage collection process, delete all the generations
3583 older than @var{duration}, for all the user profiles; when run as root, this
3584 applies to all the profiles @emph{of all the users}.
3586 For example, this command deletes all the generations of all your profiles
3587 that are older than 2 months (except generations that are current), and then
3588 proceeds to free space until at least 10 GiB are available:
3591 guix gc -d 2m -F 10G
3596 Attempt to delete all the store files and directories specified as
3597 arguments. This fails if some of the files are not in the store, or if
3598 they are still live.
3600 @item --list-failures
3601 List store items corresponding to cached build failures.
3603 This prints nothing unless the daemon was started with
3604 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3605 @option{--cache-failures}}).
3608 List the GC roots owned by the user; when run as root, list @emph{all} the GC
3612 List store items in use by currently running processes. These store
3613 items are effectively considered GC roots: they cannot be deleted.
3615 @item --clear-failures
3616 Remove the specified store items from the failed-build cache.
3618 Again, this option only makes sense when the daemon is started with
3619 @option{--cache-failures}. Otherwise, it does nothing.
3622 Show the list of dead files and directories still present in the
3623 store---i.e., files and directories no longer reachable from any root.
3626 Show the list of live store files and directories.
3630 In addition, the references among existing store files can be queried:
3636 @cindex package dependencies
3637 List the references (respectively, the referrers) of store files given
3643 List the requisites of the store files passed as arguments. Requisites
3644 include the store files themselves, their references, and the references
3645 of these, recursively. In other words, the returned list is the
3646 @dfn{transitive closure} of the store files.
3648 @xref{Invoking guix size}, for a tool to profile the size of the closure
3649 of an element. @xref{Invoking guix graph}, for a tool to visualize
3650 the graph of references.
3654 Return the derivation(s) leading to the given store items
3655 (@pxref{Derivations}).
3657 For example, this command:
3660 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3664 returns the @file{.drv} file(s) leading to the @code{emacs} package
3665 installed in your profile.
3667 Note that there may be zero matching @file{.drv} files, for instance
3668 because these files have been garbage-collected. There can also be more
3669 than one matching @file{.drv} due to fixed-output derivations.
3672 Lastly, the following options allow you to check the integrity of the
3673 store and to control disk usage.
3677 @item --verify[=@var{options}]
3678 @cindex integrity, of the store
3679 @cindex integrity checking
3680 Verify the integrity of the store.
3682 By default, make sure that all the store items marked as valid in the
3683 database of the daemon actually exist in @file{/gnu/store}.
3685 When provided, @var{options} must be a comma-separated list containing one
3686 or more of @code{contents} and @code{repair}.
3688 When passing @option{--verify=contents}, the daemon computes the
3689 content hash of each store item and compares it against its hash in the
3690 database. Hash mismatches are reported as data corruptions. Because it
3691 traverses @emph{all the files in the store}, this command can take a
3692 long time, especially on systems with a slow disk drive.
3694 @cindex repairing the store
3695 @cindex corruption, recovering from
3696 Using @option{--verify=repair} or @option{--verify=contents,repair}
3697 causes the daemon to try to repair corrupt store items by fetching
3698 substitutes for them (@pxref{Substitutes}). Because repairing is not
3699 atomic, and thus potentially dangerous, it is available only to the
3700 system administrator. A lightweight alternative, when you know exactly
3701 which items in the store are corrupt, is @command{guix build --repair}
3702 (@pxref{Invoking guix build}).
3705 @cindex deduplication
3706 Optimize the store by hard-linking identical files---this is
3707 @dfn{deduplication}.
3709 The daemon performs deduplication after each successful build or archive
3710 import, unless it was started with @option{--disable-deduplication}
3711 (@pxref{Invoking guix-daemon, @option{--disable-deduplication}}). Thus,
3712 this option is primarily useful when the daemon was running with
3713 @option{--disable-deduplication}.
3717 @node Invoking guix pull
3718 @section Invoking @command{guix pull}
3720 @cindex upgrading Guix
3721 @cindex updating Guix
3722 @cindex @command{guix pull}
3724 @cindex security, @command{guix pull}
3725 @cindex authenticity, of code obtained with @command{guix pull}
3726 Packages are installed or upgraded to the latest version available in
3727 the distribution currently available on your local machine. To update
3728 that distribution, along with the Guix tools, you must run @command{guix
3729 pull}: the command downloads the latest Guix source code and package
3730 descriptions, and deploys it. Source code is downloaded from a
3731 @uref{https://git-scm.com, Git} repository, by default the official
3732 GNU@tie{}Guix repository, though this can be customized. @command{guix
3733 pull} ensures that the code it downloads is @emph{authentic} by
3734 verifying that commits are signed by Guix developers.
3736 Specifically, @command{guix pull} downloads code from the @dfn{channels}
3737 (@pxref{Channels}) specified by one of the followings, in this order:
3741 the @option{--channels} option;
3743 the user's @file{~/.config/guix/channels.scm} file;
3745 the system-wide @file{/etc/guix/channels.scm} file;
3747 the built-in default channels specified in the @code{%default-channels}
3751 On completion, @command{guix package} will use packages and package
3752 versions from this just-retrieved copy of Guix. Not only that, but all
3753 the Guix commands and Scheme modules will also be taken from that latest
3754 version. New @command{guix} sub-commands added by the update also
3757 Any user can update their Guix copy using @command{guix pull}, and the
3758 effect is limited to the user who ran @command{guix pull}. For
3759 instance, when user @code{root} runs @command{guix pull}, this has no
3760 effect on the version of Guix that user @code{alice} sees, and vice
3763 The result of running @command{guix pull} is a @dfn{profile} available
3764 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3765 make sure to add it to the beginning of your search path so that you use
3766 the latest version, and similarly for the Info manual
3767 (@pxref{Documentation}):
3770 export PATH="$HOME/.config/guix/current/bin:$PATH"
3771 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3774 The @option{--list-generations} or @option{-l} option lists past generations
3775 produced by @command{guix pull}, along with details about their provenance:
3779 Generation 1 Jun 10 2018 00:18:18
3781 repository URL: https://git.savannah.gnu.org/git/guix.git
3782 branch: origin/master
3783 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
3785 Generation 2 Jun 11 2018 11:02:49
3787 repository URL: https://git.savannah.gnu.org/git/guix.git
3788 branch: origin/master
3789 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
3790 2 new packages: keepalived, libnfnetlink
3791 6 packages upgraded: emacs-nix-mode@@2.0.4,
3792 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
3793 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
3795 Generation 3 Jun 13 2018 23:31:07 (current)
3797 repository URL: https://git.savannah.gnu.org/git/guix.git
3798 branch: origin/master
3799 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
3800 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
3801 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
3804 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
3805 describe the current status of Guix.
3807 This @code{~/.config/guix/current} profile works exactly like the profiles
3808 created by @command{guix package} (@pxref{Invoking guix package}). That
3809 is, you can list generations, roll back to the previous
3810 generation---i.e., the previous Guix---and so on:
3813 $ guix pull --roll-back
3814 switched from generation 3 to 2
3815 $ guix pull --delete-generations=1
3816 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3819 You can also use @command{guix package} (@pxref{Invoking guix package})
3820 to manage the profile by naming it explicitly:
3822 $ guix package -p ~/.config/guix/current --roll-back
3823 switched from generation 3 to 2
3824 $ guix package -p ~/.config/guix/current --delete-generations=1
3825 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3828 The @command{guix pull} command is usually invoked with no arguments,
3829 but it supports the following options:
3832 @item --url=@var{url}
3833 @itemx --commit=@var{commit}
3834 @itemx --branch=@var{branch}
3835 Download code for the @code{guix} channel from the specified @var{url}, at the
3836 given @var{commit} (a valid Git commit ID represented as a hexadecimal
3837 string), or @var{branch}.
3839 @cindex @file{channels.scm}, configuration file
3840 @cindex configuration file for channels
3841 These options are provided for convenience, but you can also specify your
3842 configuration in the @file{~/.config/guix/channels.scm} file or using the
3843 @option{--channels} option (see below).
3845 @item --channels=@var{file}
3846 @itemx -C @var{file}
3847 Read the list of channels from @var{file} instead of
3848 @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
3849 @var{file} must contain Scheme code that
3850 evaluates to a list of channel objects. @xref{Channels}, for more
3853 @cindex channel news
3856 Display the list of packages added or upgraded since the previous
3857 generation, as well as, occasionally, news written by channel authors
3858 for their users (@pxref{Channels, Writing Channel News}).
3860 The package information is the same as displayed upon @command{guix
3861 pull} completion, but without ellipses; it is also similar to the output
3862 of @command{guix pull -l} for the last generation (see below).
3864 @item --list-generations[=@var{pattern}]
3865 @itemx -l [@var{pattern}]
3866 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
3867 is provided, the subset of generations that match @var{pattern}.
3868 The syntax of @var{pattern} is the same as with @code{guix package
3869 --list-generations} (@pxref{Invoking guix package}).
3872 @cindex rolling back
3873 @cindex undoing transactions
3874 @cindex transactions, undoing
3875 Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
3876 undo the last transaction.
3878 @item --switch-generation=@var{pattern}
3879 @itemx -S @var{pattern}
3881 Switch to a particular generation defined by @var{pattern}.
3883 @var{pattern} may be either a generation number or a number prefixed
3884 with ``+'' or ``-''. The latter means: move forward/backward by a
3885 specified number of generations. For example, if you want to return to
3886 the latest generation after @option{--roll-back}, use
3887 @option{--switch-generation=+1}.
3889 @item --delete-generations[=@var{pattern}]
3890 @itemx -d [@var{pattern}]
3891 When @var{pattern} is omitted, delete all generations except the current
3894 This command accepts the same patterns as @option{--list-generations}.
3895 When @var{pattern} is specified, delete the matching generations. When
3896 @var{pattern} specifies a duration, generations @emph{older} than the
3897 specified duration match. For instance, @option{--delete-generations=1m}
3898 deletes generations that are more than one month old.
3900 If the current generation matches, it is @emph{not} deleted.
3902 Note that deleting generations prevents rolling back to them.
3903 Consequently, this command must be used with care.
3905 @xref{Invoking guix describe}, for a way to display information about the
3906 current generation only.
3908 @item --profile=@var{profile}
3909 @itemx -p @var{profile}
3910 Use @var{profile} instead of @file{~/.config/guix/current}.
3914 Show which channel commit(s) would be used and what would be built or
3915 substituted but do not actually do it.
3917 @item --allow-downgrades
3918 Allow pulling older or unrelated revisions of channels than those
3921 @cindex downgrade attacks, protection against
3922 By default, @command{guix pull} protects against so-called ``downgrade
3923 attacks'' whereby the Git repository of a channel would be reset to an
3924 earlier or unrelated revision of itself, potentially leading you to
3925 install older, known-vulnerable versions of software packages.
3928 Make sure you understand its security implications before using
3929 @option{--allow-downgrades}.
3932 @item --disable-authentication
3933 Allow pulling channel code without authenticating it.
3935 @cindex authentication, of channel code
3936 By default, @command{guix pull} authenticates code downloaded from
3937 channels by verifying that its commits are signed by authorized
3938 developers, and raises an error if this is not the case. This option
3939 instructs it to not perform any such verification.
3942 Make sure you understand its security implications before using
3943 @option{--disable-authentication}.
3946 @item --system=@var{system}
3947 @itemx -s @var{system}
3948 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3949 the system type of the build host.
3952 Use the bootstrap Guile to build the latest Guix. This option is only
3953 useful to Guix developers.
3956 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
3957 repository and branch to pull from, as well as @emph{additional} repositories
3958 containing package modules that should be deployed. @xref{Channels}, for more
3961 In addition, @command{guix pull} supports all the common build options
3962 (@pxref{Common Build Options}).
3968 @cindex @file{channels.scm}, configuration file
3969 @cindex configuration file for channels
3970 @cindex @command{guix pull}, configuration file
3971 @cindex configuration of @command{guix pull}
3972 Guix and its package collection are updated by running @command{guix pull}
3973 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
3974 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
3975 customized by defining @dfn{channels} in the
3976 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
3977 of a Git repository to be deployed, and @command{guix pull} can be instructed
3978 to pull from one or more channels. In other words, channels can be used
3979 to @emph{customize} and to @emph{extend} Guix, as we will see below.
3980 Before that, some security considerations.
3982 @subsection Channel Authentication
3984 @anchor{channel-authentication}
3985 @cindex authentication, of channel code
3986 The @command{guix pull} and @command{guix time-machine} commands
3987 @dfn{authenticate} the code retrieved from channels: they make sure each
3988 commit that is fetched is signed by an authorized developer. The goal
3989 is to protect from unauthorized modifications to the channel that would
3990 lead users to run malicious code.
3992 As a user, you must provide a @dfn{channel introduction} in your
3993 channels file so that Guix knows how to authenticate its first commit.
3994 A channel specification, including its introduction, looks something
4000 (url "https://example.org/my-channel.git")
4002 (make-channel-introduction
4003 "6f0d8cc0d88abb59c324b2990bfee2876016bb86"
4004 (openpgp-fingerprint
4005 "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
4008 The specification above shows the name and URL of the channel. The call
4009 to @code{make-channel-introduction} above specifies that authentication
4010 of this channel starts at commit @code{6f0d8cc@dots{}}, which is signed
4011 by the OpenPGP key with fingerprint @code{CABB A931@dots{}}.
4013 For the main channel, called @code{guix}, you automatically get that
4014 information from your Guix installation. For other channels, include
4015 the channel introduction provided by the channel authors in your
4016 @file{channels.scm} file. Make sure you retrieve the channel
4017 introduction from a trusted source since that is the root of your trust.
4019 If you're curious about the authentication mechanics, read on!
4021 @subsection Using a Custom Guix Channel
4023 The channel called @code{guix} specifies where Guix itself---its command-line
4024 tools as well as its package collection---should be downloaded. For instance,
4025 suppose you want to update from your own copy of the Guix repository at
4026 @code{example.org}, and specifically the @code{super-hacks} branch, you can
4027 write in @code{~/.config/guix/channels.scm} this specification:
4030 ;; Tell 'guix pull' to use my own repo.
4033 (url "https://example.org/my-guix.git")
4034 (branch "super-hacks")))
4038 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
4039 branch of the repository at @code{example.org}.
4041 @subsection Specifying Additional Channels
4043 @cindex extending the package collection (channels)
4044 @cindex personal packages (channels)
4045 @cindex channels, for personal packages
4046 You can also specify @emph{additional channels} to pull from. Let's say you
4047 have a bunch of custom package variants or personal packages that you think
4048 would make little sense to contribute to the Guix project, but would like to
4049 have these packages transparently available to you at the command line. You
4050 would first write modules containing those package definitions (@pxref{Package
4051 Modules}), maintain them in a Git repository, and then you and anyone else can
4052 use it as an additional channel to get packages from. Neat, no?
4054 @c What follows stems from discussions at
4055 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
4056 @c earlier discussions on guix-devel@gnu.org.
4058 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
4059 publish your personal channel to the world, we would like to share a few words
4064 Before publishing a channel, please consider contributing your package
4065 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
4066 to free software of all sorts, and packages in Guix proper are readily
4067 available to all Guix users and benefit from the project's quality assurance
4071 When you maintain package definitions outside Guix, we, Guix developers,
4072 consider that @emph{the compatibility burden is on you}. Remember that
4073 package modules and package definitions are just Scheme code that uses various
4074 programming interfaces (APIs). We want to remain free to change these APIs to
4075 keep improving Guix, possibly in ways that break your channel. We never
4076 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
4080 Corollary: if you're using an external channel and that channel breaks, please
4081 @emph{report the issue to the channel authors}, not to the Guix project.
4084 You've been warned! Having said this, we believe external channels are a
4085 practical way to exert your freedom to augment Guix' package collection and to
4086 share your improvements, which are basic tenets of
4087 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
4088 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
4091 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
4092 @command{guix pull} to pull from it @emph{in addition} to the default Guix
4095 @vindex %default-channels
4097 ;; Add my personal packages to those Guix provides.
4099 (name 'my-personal-packages)
4100 (url "https://example.org/personal-packages.git"))
4105 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
4106 add a channel the list of channels that the variable @code{%default-channels}
4107 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
4108 Manual}). With this file in place, @command{guix pull} builds not only Guix
4109 but also the package modules from your own repository. The result in
4110 @file{~/.config/guix/current} is the union of Guix with your own package
4114 $ guix pull --list-generations
4116 Generation 19 Aug 27 2018 16:20:48
4118 repository URL: https://git.savannah.gnu.org/git/guix.git
4120 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
4121 my-personal-packages dd3df5e
4122 repository URL: https://example.org/personal-packages.git
4124 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
4125 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
4126 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
4130 The output of @command{guix pull} above shows that Generation@tie{}19 includes
4131 both Guix and packages from the @code{my-personal-packages} channel. Among
4132 the new and upgraded packages that are listed, some like @code{my-gimp} and
4133 @code{my-emacs-with-cool-features} might come from
4134 @code{my-personal-packages}, while others come from the Guix default channel.
4136 To create a channel, create a Git repository containing your own package
4137 modules and make it available. The repository can contain anything, but a
4138 useful channel will contain Guile modules that export packages. Once you
4139 start using a channel, Guix will behave as if the root directory of that
4140 channel's Git repository has been added to the Guile load path (@pxref{Load
4141 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
4142 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
4143 module, then the module will be available under the name @code{(my-packages
4144 my-tools)}, and you will be able to use it like any other module
4145 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
4147 @cindex dependencies, channels
4148 @cindex meta-data, channels
4149 @subsection Declaring Channel Dependencies
4151 Channel authors may decide to augment a package collection provided by other
4152 channels. They can declare their channel to be dependent on other channels in
4153 a meta-data file @file{.guix-channel}, which is to be placed in the root of
4154 the channel repository.
4156 The meta-data file should contain a simple S-expression like this:
4163 (name some-collection)
4164 (url "https://example.org/first-collection.git")
4166 ;; The 'introduction' bit below is optional: you would
4167 ;; provide it for dependencies that can be authenticated.
4169 (channel-introduction
4171 (commit "a8883b58dc82e167c96506cf05095f37c2c2c6cd")
4172 (signer "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
4174 (name some-other-collection)
4175 (url "https://example.org/second-collection.git")
4176 (branch "testing"))))
4179 In the above example this channel is declared to depend on two other channels,
4180 which will both be fetched automatically. The modules provided by the channel
4181 will be compiled in an environment where the modules of all these declared
4182 channels are available.
4184 For the sake of reliability and maintainability, you should avoid dependencies
4185 on channels that you don't control, and you should aim to keep the number of
4186 dependencies to a minimum.
4188 @cindex subdirectory, channels
4189 @subsection Package Modules in a Sub-directory
4191 As a channel author, you may want to keep your channel modules in a
4192 sub-directory. If your modules are in the sub-directory @file{guix}, you must
4193 add a meta-data file @file{.guix-channel} that contains:
4201 @cindex channel authorizations
4202 @subsection Specifying Channel Authorizations
4204 @anchor{channel-authorizations}
4205 As we saw above, Guix ensures the source code it pulls from channels
4206 comes from authorized developers. As a channel author, you need to
4207 specify the list of authorized developers in the
4208 @file{.guix-authorizations} file in the channel's Git repository. The
4209 authentication rule is simple: each commit must be signed by a key
4210 listed in the @file{.guix-authorizations} file of its parent
4211 commit(s)@footnote{Git commits form a @dfn{directed acyclic graph}
4212 (DAG). Each commit can have zero or more parents; ``regular'' commits
4213 have one parent and merge commits have two parent commits. Read
4214 @uref{https://eagain.net/articles/git-for-computer-scientists/, @i{Git
4215 for Computer Scientists}} for a great overview.} The
4216 @file{.guix-authorizations} file looks like this:
4219 ;; Example '.guix-authorizations' file.
4222 (version 0) ;current file format version
4224 (("AD17 A21E F8AE D8F1 CC02 DBD9 F8AE D8F1 765C 61E3"
4226 ("2A39 3FFF 68F4 EF7A 3D29 12AF 68F4 EF7A 22FB B2D5"
4228 ("CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"
4232 Each fingerprint is followed by optional key/value pairs, as in the
4233 example above. Currently these key/value pairs are ignored.
4235 This authentication rule creates a chicken-and-egg issue: how do we
4236 authenticate the first commit? Related to that: how do we deal with
4237 channels whose repository history contains unsigned commits and lack
4238 @file{.guix-authorizations}? And how do we fork existing channels?
4240 @cindex channel introduction
4241 Channel introductions answer these questions by describing the first
4242 commit of a channel that should be authenticated. The first time a
4243 channel is fetched with @command{guix pull} or @command{guix
4244 time-machine}, the command looks up the introductory commit and verifies
4245 that it is signed by the specified OpenPGP key. From then on, it
4246 authenticates commits according to the rule above.
4248 To summarize, as the author of a channel, there are two things you have
4249 to do to allow users to authenticate your code:
4253 Introduce an initial @file{.guix-authorizations} in the channel's
4254 repository. Do that in a signed commit (@pxref{Commit Access}, for
4255 information on how to sign Git commits.)
4258 Advertise the channel introduction, for instance on your channel's web
4259 page. The channel introduction, as we saw above, is the commit/key
4260 pair---i.e., the commit that introduced @file{.guix-authorizations}, and
4261 the fingerprint of the OpenPGP used to sign it.
4264 Before pushing to your public Git repository, you can run @command{guix
4265 git-authenticate} to verify that you did sign all the commits you are
4266 about to push with an authorized key:
4269 guix git authenticate @var{commit} @var{signer}
4273 where @var{commit} and @var{signer} are your channel introduction.
4274 @xref{Invoking guix git authenticate}, for details.
4276 Publishing a signed channel requires discipline: any mistake, such as an
4277 unsigned commit or a commit signed by an unauthorized key, will prevent
4278 users from pulling from your channel---well, that's the whole point of
4279 authentication! Pay attention to merges in particular: merge commits
4280 are considered authentic if and only if they are signed by a key present
4281 in the @file{.guix-authorizations} file of @emph{both} branches.
4283 @cindex primary URL, channels
4284 @subsection Primary URL
4286 Channel authors can indicate the primary URL of their channel's Git
4287 repository in the @file{.guix-channel} file, like so:
4292 (url "https://example.org/guix.git"))
4295 This allows @command{guix pull} to determine whether it is pulling code
4296 from a mirror of the channel; when that is the case, it warns the user
4297 that the mirror might be stale and displays the primary URL. That way,
4298 users cannot be tricked into fetching code from a stale mirror that does
4299 not receive security updates.
4301 This feature only makes sense for authenticated repositories, such as
4302 the official @code{guix} channel, for which @command{guix pull} ensures
4303 the code it fetches is authentic.
4305 @cindex news, for channels
4306 @subsection Writing Channel News
4308 Channel authors may occasionally want to communicate to their users
4309 information about important changes in the channel. You'd send them all
4310 an email, but that's not convenient.
4312 Instead, channels can provide a @dfn{news file}; when the channel users
4313 run @command{guix pull}, that news file is automatically read and
4314 @command{guix pull --news} can display the announcements that correspond
4315 to the new commits that have been pulled, if any.
4317 To do that, channel authors must first declare the name of the news file
4318 in their @file{.guix-channel} file:
4323 (news-file "etc/news.txt"))
4326 The news file itself, @file{etc/news.txt} in this example, must look
4327 something like this:
4332 (entry (tag "the-bug-fix")
4333 (title (en "Fixed terrible bug")
4335 (body (en "@@emph@{Good news@}! It's fixed!")
4336 (eo "Certe ĝi pli bone funkcias nun!")))
4337 (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
4338 (title (en "Added a great package")
4339 (ca "Què vol dir guix?"))
4340 (body (en "Don't miss the @@code@{hello@} package!"))))
4343 The file consists of a list of @dfn{news entries}. Each entry is
4344 associated with a commit or tag: it describes changes made in this
4345 commit, possibly in preceding commits as well. Users see entries only
4346 the first time they obtain the commit the entry refers to.
4348 The @code{title} field should be a one-line summary while @code{body}
4349 can be arbitrarily long, and both can contain Texinfo markup
4350 (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
4351 a list of language tag/message tuples, which allows @command{guix pull}
4352 to display news in the language that corresponds to the user's locale.
4354 If you want to translate news using a gettext-based workflow, you can
4355 extract translatable strings with @command{xgettext} (@pxref{xgettext
4356 Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
4357 you write news entries in English first, the command below creates a PO
4358 file containing the strings to translate:
4361 xgettext -o news.po -l scheme -ken etc/news.scm
4364 To sum up, yes, you could use your channel as a blog. But beware, this
4365 is @emph{not quite} what your users might expect.
4367 @subsection Replicating Guix
4369 @cindex pinning, channels
4370 @cindex replicating Guix
4371 @cindex reproducibility, of Guix
4372 The @command{guix pull --list-generations} output above shows precisely which
4373 commits were used to build this instance of Guix. We can thus replicate it,
4374 say, on another machine, by providing a channel specification in
4375 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
4378 ;; Deploy specific commits of my channels of interest.
4381 (url "https://git.savannah.gnu.org/git/guix.git")
4382 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
4384 (name 'my-personal-packages)
4385 (url "https://example.org/personal-packages.git")
4386 (commit "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
4389 The @command{guix describe --format=channels} command can even generate this
4390 list of channels directly (@pxref{Invoking guix describe}). The resulting
4391 file can be used with the -C options of @command{guix pull}
4392 (@pxref{Invoking guix pull}) or @command{guix time-machine}
4393 (@pxref{Invoking guix time-machine}).
4395 At this point the two machines run the @emph{exact same Guix}, with access to
4396 the @emph{exact same packages}. The output of @command{guix build gimp} on
4397 one machine will be exactly the same, bit for bit, as the output of the same
4398 command on the other machine. It also means both machines have access to all
4399 the source code of Guix and, transitively, to all the source code of every
4402 This gives you super powers, allowing you to track the provenance of binary
4403 artifacts with very fine grain, and to reproduce software environments at
4404 will---some sort of ``meta reproducibility'' capabilities, if you will.
4405 @xref{Inferiors}, for another way to take advantage of these super powers.
4407 @node Invoking guix time-machine
4408 @section Invoking @command{guix time-machine}
4410 @cindex @command{guix time-machine}
4411 @cindex pinning, channels
4412 @cindex replicating Guix
4413 @cindex reproducibility, of Guix
4415 The @command{guix time-machine} command provides access to other
4416 revisions of Guix, for example to install older versions of packages,
4417 or to reproduce a computation in an identical environment. The revision
4418 of Guix to be used is defined by a commit or by a channel
4419 description file created by @command{guix describe}
4420 (@pxref{Invoking guix describe}).
4422 The general syntax is:
4425 guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
4428 where @var{command} and @var{arg}@dots{} are passed unmodified to the
4429 @command{guix} command of the specified revision. The @var{options} that define
4430 this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
4433 @item --url=@var{url}
4434 @itemx --commit=@var{commit}
4435 @itemx --branch=@var{branch}
4436 Use the @code{guix} channel from the specified @var{url}, at the
4437 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4438 string), or @var{branch}.
4440 @item --channels=@var{file}
4441 @itemx -C @var{file}
4442 Read the list of channels from @var{file}. @var{file} must contain
4443 Scheme code that evaluates to a list of channel objects.
4444 @xref{Channels} for more information.
4447 As for @command{guix pull}, the absence of any options means that the
4448 the latest commit on the master branch will be used. The command
4451 guix time-machine -- build hello
4454 will thus build the package @code{hello} as defined in the master branch,
4455 which is in general a newer revision of Guix than you have installed.
4456 Time travel works in both directions!
4458 Note that @command{guix time-machine} can trigger builds of channels and
4459 their dependencies, and these are controlled by the standard build
4460 options (@pxref{Common Build Options}).
4465 @c TODO: Remove this once we're more confident about API stability.
4467 The functionality described here is a ``technology preview'' as of version
4468 @value{VERSION}. As such, the interface is subject to change.
4472 @cindex composition of Guix revisions
4473 Sometimes you might need to mix packages from the revision of Guix you're
4474 currently running with packages available in a different revision of Guix.
4475 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
4476 revisions in arbitrary ways.
4478 @cindex inferior packages
4479 Technically, an ``inferior'' is essentially a separate Guix process connected
4480 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4481 @code{(guix inferior)} module allows you to create inferiors and to
4482 communicate with them. It also provides a high-level interface to browse and
4483 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4485 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4486 to interact with a separate revision of Guix. For example, let's assume you
4487 want to install in your profile the current @code{guile} package, along with
4488 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4489 because the newer @code{guile-json} has an incompatible API and you want to
4490 run your code against the old API@. To do that, you could write a manifest for
4491 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4492 manifest, you would create an inferior for that old Guix revision you care
4493 about, and you would look up the @code{guile-json} package in the inferior:
4496 (use-modules (guix inferior) (guix channels)
4497 (srfi srfi-1)) ;for 'first'
4500 ;; This is the old revision from which we want to
4501 ;; extract guile-json.
4504 (url "https://git.savannah.gnu.org/git/guix.git")
4506 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4509 ;; An inferior representing the above revision.
4510 (inferior-for-channels channels))
4512 ;; Now create a manifest with the current "guile" package
4513 ;; and the old "guile-json" package.
4515 (list (first (lookup-inferior-packages inferior "guile-json"))
4516 (specification->package "guile")))
4519 On its first run, @command{guix package --manifest} might have to build the
4520 channel you specified before it can create the inferior; subsequent runs will
4521 be much faster because the Guix revision will be cached.
4523 The @code{(guix inferior)} module provides the following procedures to open an
4526 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4527 [#:cache-directory] [#:ttl]
4528 Return an inferior for @var{channels}, a list of channels. Use the cache at
4529 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4530 This procedure opens a new connection to the build daemon.
4532 As a side effect, this procedure may build or substitute binaries for
4533 @var{channels}, which can take time.
4536 @deffn {Scheme Procedure} open-inferior @var{directory} @
4537 [#:command "bin/guix"]
4538 Open the inferior Guix in @var{directory}, running
4539 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4540 the inferior could not be launched.
4543 @cindex inferior packages
4544 The procedures listed below allow you to obtain and manipulate inferior
4547 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4548 Return the list of packages known to @var{inferior}.
4551 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4553 Return the sorted list of inferior packages matching @var{name} in
4554 @var{inferior}, with highest version numbers first. If @var{version} is true,
4555 return only packages with a version number prefixed by @var{version}.
4558 @deffn {Scheme Procedure} inferior-package? @var{obj}
4559 Return true if @var{obj} is an inferior package.
4562 @deffn {Scheme Procedure} inferior-package-name @var{package}
4563 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4564 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4565 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4566 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4567 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4568 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4569 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4570 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4571 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4572 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4573 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4574 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4575 These procedures are the counterpart of package record accessors
4576 (@pxref{package Reference}). Most of them work by querying the inferior
4577 @var{package} comes from, so the inferior must still be live when you call
4581 Inferior packages can be used transparently like any other package or
4582 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4583 transparently handled by the @code{packages->manifest} procedure, which is
4584 commonly use in manifests (@pxref{Invoking guix package, the
4585 @option{--manifest} option of @command{guix package}}). Thus you can insert
4586 an inferior package pretty much anywhere you would insert a regular package:
4587 in manifests, in the @code{packages} field of your @code{operating-system}
4588 declaration, and so on.
4590 @node Invoking guix describe
4591 @section Invoking @command{guix describe}
4593 @cindex reproducibility
4594 @cindex replicating Guix
4595 Often you may want to answer questions like: ``Which revision of Guix am I
4596 using?'' or ``Which channels am I using?'' This is useful information in many
4597 situations: if you want to @emph{replicate} an environment on a different
4598 machine or user account, if you want to report a bug or to determine what
4599 change in the channels you are using caused it, or if you want to record your
4600 system state for reproducibility purposes. The @command{guix describe}
4601 command answers these questions.
4603 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4604 displays the channel(s) that it was built from, including their repository URL
4605 and commit IDs (@pxref{Channels}):
4609 Generation 10 Sep 03 2018 17:32:44 (current)
4611 repository URL: https://git.savannah.gnu.org/git/guix.git
4613 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4616 If you're familiar with the Git version control system, this is similar in
4617 spirit to @command{git describe}; the output is also similar to that of
4618 @command{guix pull --list-generations}, but limited to the current generation
4619 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4620 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4621 information is all it takes to describe the revision of Guix you're using, and
4622 also to replicate it.
4624 To make it easier to replicate Guix, @command{guix describe} can also be asked
4625 to return a list of channels instead of the human-readable description above:
4628 $ guix describe -f channels
4631 (url "https://git.savannah.gnu.org/git/guix.git")
4633 "e0fa68c7718fffd33d81af415279d6ddb518f727")
4635 (make-channel-introduction
4636 "9edb3f66fd807b096b48283debdcddccfea34bad"
4637 (openpgp-fingerprint
4638 "BBB0 2DDF 2CEA F6A8 0D1D E643 A2A0 6DF2 A33A 54FA")))))
4642 You can save this to a file and feed it to @command{guix pull -C} on some
4643 other machine or at a later point in time, which will instantiate @emph{this
4644 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4645 From there on, since you're able to deploy the same revision of Guix, you can
4646 just as well @emph{replicate a complete software environment}. We humbly
4647 think that this is @emph{awesome}, and we hope you'll like it too!
4649 The details of the options supported by @command{guix describe} are as
4653 @item --format=@var{format}
4654 @itemx -f @var{format}
4655 Produce output in the specified @var{format}, one of:
4659 produce human-readable output;
4661 produce a list of channel specifications that can be passed to @command{guix
4662 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4664 @item channels-sans-intro
4665 like @code{channels}, but omit the @code{introduction} field; use it to
4666 produce a channel specification suitable for Guix version 1.1.0 or
4667 earlier---the @code{introduction} field has to do with channel
4668 authentication (@pxref{Channels, Channel Authentication}) and is not
4669 supported by these older versions;
4672 produce a list of channel specifications in JSON format;
4674 produce a list of channel specifications in Recutils format.
4677 @item --list-formats
4678 Display available formats for @option{--format} option.
4680 @item --profile=@var{profile}
4681 @itemx -p @var{profile}
4682 Display information about @var{profile}.
4685 @node Invoking guix archive
4686 @section Invoking @command{guix archive}
4688 @cindex @command{guix archive}
4690 The @command{guix archive} command allows users to @dfn{export} files
4691 from the store into a single archive, and to later @dfn{import} them on
4692 a machine that runs Guix.
4693 In particular, it allows store files to be transferred from one machine
4694 to the store on another machine.
4697 If you're looking for a way to produce archives in a format suitable for
4698 tools other than Guix, @pxref{Invoking guix pack}.
4701 @cindex exporting store items
4702 To export store files as an archive to standard output, run:
4705 guix archive --export @var{options} @var{specifications}...
4708 @var{specifications} may be either store file names or package
4709 specifications, as for @command{guix package} (@pxref{Invoking guix
4710 package}). For instance, the following command creates an archive
4711 containing the @code{gui} output of the @code{git} package and the main
4712 output of @code{emacs}:
4715 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4718 If the specified packages are not built yet, @command{guix archive}
4719 automatically builds them. The build process may be controlled with the
4720 common build options (@pxref{Common Build Options}).
4722 To transfer the @code{emacs} package to a machine connected over SSH,
4726 guix archive --export -r emacs | ssh the-machine guix archive --import
4730 Similarly, a complete user profile may be transferred from one machine
4731 to another like this:
4734 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4735 ssh the-machine guix archive --import
4739 However, note that, in both examples, all of @code{emacs} and the
4740 profile as well as all of their dependencies are transferred (due to
4741 @option{-r}), regardless of what is already available in the store on
4742 the target machine. The @option{--missing} option can help figure out
4743 which items are missing from the target store. The @command{guix copy}
4744 command simplifies and optimizes this whole process, so this is probably
4745 what you should use in this case (@pxref{Invoking guix copy}).
4747 @cindex nar, archive format
4748 @cindex normalized archive (nar)
4749 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
4750 comparable in spirit to `tar', but with differences
4751 that make it more appropriate for our purposes. First, rather than
4752 recording all Unix metadata for each file, the nar format only mentions
4753 the file type (regular, directory, or symbolic link); Unix permissions
4754 and owner/group are dismissed. Second, the order in which directory
4755 entries are stored always follows the order of file names according to
4756 the C locale collation order. This makes archive production fully
4759 When exporting, the daemon digitally signs the contents of the archive,
4760 and that digital signature is appended. When importing, the daemon
4761 verifies the signature and rejects the import in case of an invalid
4762 signature or if the signing key is not authorized.
4763 @c FIXME: Add xref to daemon doc about signatures.
4765 The main options are:
4769 Export the specified store files or packages (see below). Write the
4770 resulting archive to the standard output.
4772 Dependencies are @emph{not} included in the output, unless
4773 @option{--recursive} is passed.
4777 When combined with @option{--export}, this instructs @command{guix archive}
4778 to include dependencies of the given items in the archive. Thus, the
4779 resulting archive is self-contained: it contains the closure of the
4780 exported store items.
4783 Read an archive from the standard input, and import the files listed
4784 therein into the store. Abort if the archive has an invalid digital
4785 signature, or if it is signed by a public key not among the authorized
4786 keys (see @option{--authorize} below).
4789 Read a list of store file names from the standard input, one per line,
4790 and write on the standard output the subset of these files missing from
4793 @item --generate-key[=@var{parameters}]
4794 @cindex signing, archives
4795 Generate a new key pair for the daemon. This is a prerequisite before
4796 archives can be exported with @option{--export}. Note that this
4797 operation usually takes time, because it needs to gather enough entropy
4798 to generate the key pair.
4800 The generated key pair is typically stored under @file{/etc/guix}, in
4801 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4802 key, which must be kept secret). When @var{parameters} is omitted,
4803 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4804 versions before 1.6.0, it is a 4096-bit RSA key.
4805 Alternatively, @var{parameters} can specify
4806 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4807 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4808 Libgcrypt Reference Manual}).
4811 @cindex authorizing, archives
4812 Authorize imports signed by the public key passed on standard input.
4813 The public key must be in ``s-expression advanced format''---i.e., the
4814 same format as the @file{signing-key.pub} file.
4816 The list of authorized keys is kept in the human-editable file
4817 @file{/etc/guix/acl}. The file contains
4818 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4819 s-expressions''} and is structured as an access-control list in the
4820 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4823 @item --extract=@var{directory}
4824 @itemx -x @var{directory}
4825 Read a single-item archive as served by substitute servers
4826 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4827 low-level operation needed in only very narrow use cases; see below.
4829 For example, the following command extracts the substitute for Emacs
4830 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4834 https://@value{SUBSTITUTE-SERVER}/nar/gzip/@dots{}-emacs-24.5 \
4835 | gunzip | guix archive -x /tmp/emacs
4838 Single-item archives are different from multiple-item archives produced
4839 by @command{guix archive --export}; they contain a single store item,
4840 and they do @emph{not} embed a signature. Thus this operation does
4841 @emph{no} signature verification and its output should be considered
4844 The primary purpose of this operation is to facilitate inspection of
4845 archive contents coming from possibly untrusted substitute servers
4846 (@pxref{Invoking guix challenge}).
4850 Read a single-item archive as served by substitute servers
4851 (@pxref{Substitutes}) and print the list of files it contains, as in
4856 https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-emacs-26.3 \
4857 | lzip -d | guix archive -t
4863 @c *********************************************************************
4865 @chapter Development
4867 @cindex software development
4868 If you are a software developer, Guix provides tools that you should find
4869 helpful---independently of the language you're developing in. This is what
4870 this chapter is about.
4872 The @command{guix environment} command provides a convenient way to set up
4873 @dfn{development environments} containing all the dependencies and tools
4874 necessary to work on the software package of your choice. The @command{guix
4875 pack} command allows you to create @dfn{application bundles} that can be
4876 easily distributed to users who do not run Guix.
4879 * Invoking guix environment:: Setting up development environments.
4880 * Invoking guix pack:: Creating software bundles.
4881 * The GCC toolchain:: Working with languages supported by GCC.
4882 * Invoking guix git authenticate:: Authenticating Git repositories.
4885 @node Invoking guix environment
4886 @section Invoking @command{guix environment}
4888 @cindex reproducible build environments
4889 @cindex development environments
4890 @cindex @command{guix environment}
4891 @cindex environment, package build environment
4892 The purpose of @command{guix environment} is to assist hackers in
4893 creating reproducible development environments without polluting their
4894 package profile. The @command{guix environment} tool takes one or more
4895 packages, builds all of their inputs, and creates a shell
4896 environment to use them.
4898 The general syntax is:
4901 guix environment @var{options} @var{package}@dots{}
4904 The following example spawns a new shell set up for the development of
4908 guix environment guile
4911 If the needed dependencies are not built yet, @command{guix environment}
4912 automatically builds them. The environment of the new shell is an
4913 augmented version of the environment that @command{guix environment} was
4914 run in. It contains the necessary search paths for building the given
4915 package added to the existing environment variables. To create
4916 a ``pure'' environment, in which the original environment variables have
4917 been unset, use the @option{--pure} option@footnote{Users sometimes
4918 wrongfully augment environment variables such as @env{PATH} in their
4919 @file{~/.bashrc} file. As a consequence, when @command{guix
4920 environment} launches it, Bash may read @file{~/.bashrc}, thereby
4921 introducing ``impurities'' in these environment variables. It is an
4922 error to define such environment variables in @file{.bashrc}; instead,
4923 they should be defined in @file{.bash_profile}, which is sourced only by
4924 log-in shells. @xref{Bash Startup Files,,, bash, The GNU Bash Reference
4925 Manual}, for details on Bash start-up files.}.
4927 @vindex GUIX_ENVIRONMENT
4928 @command{guix environment} defines the @env{GUIX_ENVIRONMENT}
4929 variable in the shell it spawns; its value is the file name of the
4930 profile of this environment. This allows users to, say, define a
4931 specific prompt for development environments in their @file{.bashrc}
4932 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
4935 if [ -n "$GUIX_ENVIRONMENT" ]
4937 export PS1="\u@@\h \w [dev]\$ "
4942 ...@: or to browse the profile:
4945 $ ls "$GUIX_ENVIRONMENT/bin"
4948 Additionally, more than one package may be specified, in which case the
4949 union of the inputs for the given packages are used. For example, the
4950 command below spawns a shell where all of the dependencies of both Guile
4951 and Emacs are available:
4954 guix environment guile emacs
4957 Sometimes an interactive shell session is not desired. An arbitrary
4958 command may be invoked by placing the @code{--} token to separate the
4959 command from the rest of the arguments:
4962 guix environment guile -- make -j4
4965 In other situations, it is more convenient to specify the list of
4966 packages needed in the environment. For example, the following command
4967 runs @command{python} from an environment containing Python@tie{}2.7 and
4971 guix environment --ad-hoc python2-numpy python-2.7 -- python
4974 Furthermore, one might want the dependencies of a package and also some
4975 additional packages that are not build-time or runtime dependencies, but
4976 are useful when developing nonetheless. Because of this, the
4977 @option{--ad-hoc} flag is positional. Packages appearing before
4978 @option{--ad-hoc} are interpreted as packages whose dependencies will be
4979 added to the environment. Packages appearing after are interpreted as
4980 packages that will be added to the environment directly. For example,
4981 the following command creates a Guix development environment that
4982 additionally includes Git and strace:
4985 guix environment --pure guix --ad-hoc git strace
4989 Sometimes it is desirable to isolate the environment as much as
4990 possible, for maximal purity and reproducibility. In particular, when
4991 using Guix on a host distro that is not Guix System, it is desirable to
4992 prevent access to @file{/usr/bin} and other system-wide resources from
4993 the development environment. For example, the following command spawns
4994 a Guile REPL in a ``container'' where only the store and the current
4995 working directory are mounted:
4998 guix environment --ad-hoc --container guile -- guile
5002 The @option{--container} option requires Linux-libre 3.19 or newer.
5005 @cindex certificates
5006 Another typical use case for containers is to run security-sensitive
5007 applications such as a web browser. To run Eolie, we must expose and
5008 share some files and directories; we include @code{nss-certs} and expose
5009 @file{/etc/ssl/certs/} for HTTPS authentication; finally we preserve the
5010 the @env{DISPLAY} environment variable since containerized graphical
5011 applications won't display without it.
5014 guix environment --preserve='^DISPLAY$' --container --network \
5015 --expose=/etc/machine-id \
5016 --expose=/etc/ssl/certs/ \
5017 --share=$HOME/.local/share/eolie/=$HOME/.local/share/eolie/ \
5018 --ad-hoc eolie nss-certs dbus -- eolie
5021 The available options are summarized below.
5024 @item --root=@var{file}
5025 @itemx -r @var{file}
5026 @cindex persistent environment
5027 @cindex garbage collector root, for environments
5028 Make @var{file} a symlink to the profile for this environment, and
5029 register it as a garbage collector root.
5031 This is useful if you want to protect your environment from garbage
5032 collection, to make it ``persistent''.
5034 When this option is omitted, the environment is protected from garbage
5035 collection only for the duration of the @command{guix environment}
5036 session. This means that next time you recreate the same environment,
5037 you could have to rebuild or re-download packages. @xref{Invoking guix
5038 gc}, for more on GC roots.
5040 @item --expression=@var{expr}
5041 @itemx -e @var{expr}
5042 Create an environment for the package or list of packages that
5043 @var{expr} evaluates to.
5045 For example, running:
5048 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
5051 starts a shell with the environment for this specific variant of the
5057 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
5060 starts a shell with all the base system packages available.
5062 The above commands only use the default output of the given packages.
5063 To select other outputs, two element tuples can be specified:
5066 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
5069 @item --load=@var{file}
5070 @itemx -l @var{file}
5071 Create an environment for the package or list of packages that the code
5072 within @var{file} evaluates to.
5074 As an example, @var{file} might contain a definition like this
5075 (@pxref{Defining Packages}):
5078 @verbatiminclude environment-gdb.scm
5081 @item --manifest=@var{file}
5082 @itemx -m @var{file}
5083 Create an environment for the packages contained in the manifest object
5084 returned by the Scheme code in @var{file}. This option can be repeated
5085 several times, in which case the manifests are concatenated.
5087 This is similar to the same-named option in @command{guix package}
5088 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
5092 Include all specified packages in the resulting environment, as if an
5093 @i{ad hoc} package were defined with them as inputs. This option is
5094 useful for quickly creating an environment without having to write a
5095 package expression to contain the desired inputs.
5097 For instance, the command:
5100 guix environment --ad-hoc guile guile-sdl -- guile
5103 runs @command{guile} in an environment where Guile and Guile-SDL are
5106 Note that this example implicitly asks for the default output of
5107 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
5108 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
5109 of @code{glib} (@pxref{Packages with Multiple Outputs}).
5111 This option may be composed with the default behavior of @command{guix
5112 environment}. Packages appearing before @option{--ad-hoc} are
5113 interpreted as packages whose dependencies will be added to the
5114 environment, the default behavior. Packages appearing after are
5115 interpreted as packages that will be added to the environment directly.
5118 Unset existing environment variables when building the new environment, except
5119 those specified with @option{--preserve} (see below). This has the effect of
5120 creating an environment in which search paths only contain package inputs.
5122 @item --preserve=@var{regexp}
5123 @itemx -E @var{regexp}
5124 When used alongside @option{--pure}, preserve the environment variables
5125 matching @var{regexp}---in other words, put them on a ``white list'' of
5126 environment variables that must be preserved. This option can be repeated
5130 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
5134 This example runs @command{mpirun} in a context where the only environment
5135 variables defined are @env{PATH}, environment variables whose name starts
5136 with @samp{SLURM}, as well as the usual ``precious'' variables (@env{HOME},
5139 @item --search-paths
5140 Display the environment variable definitions that make up the
5143 @item --system=@var{system}
5144 @itemx -s @var{system}
5145 Attempt to build for @var{system}---e.g., @code{i686-linux}.
5150 Run @var{command} within an isolated container. The current working
5151 directory outside the container is mapped inside the container.
5152 Additionally, unless overridden with @option{--user}, a dummy home
5153 directory is created that matches the current user's home directory, and
5154 @file{/etc/passwd} is configured accordingly.
5156 The spawned process runs as the current user outside the container. Inside
5157 the container, it has the same UID and GID as the current user, unless
5158 @option{--user} is passed (see below).
5162 For containers, share the network namespace with the host system.
5163 Containers created without this flag only have access to the loopback
5166 @item --link-profile
5168 For containers, link the environment profile to @file{~/.guix-profile}
5169 within the container. This is equivalent to running the command
5170 @samp{ln -s $GUIX_ENVIRONMENT ~/.guix-profile} within the container.
5171 Linking will fail and abort the environment if the directory already
5172 exists, which will certainly be the case if @command{guix environment}
5173 was invoked in the user's home directory.
5175 Certain packages are configured to look in @file{~/.guix-profile} for
5176 configuration files and data;@footnote{For example, the
5177 @code{fontconfig} package inspects @file{~/.guix-profile/share/fonts}
5178 for additional fonts.} @option{--link-profile} allows these programs to
5179 behave as expected within the environment.
5181 @item --user=@var{user}
5182 @itemx -u @var{user}
5183 For containers, use the username @var{user} in place of the current
5184 user. The generated @file{/etc/passwd} entry within the container will
5185 contain the name @var{user}, the home directory will be
5186 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
5187 the UID and GID inside the container are 1000. @var{user}
5188 need not exist on the system.
5190 Additionally, any shared or exposed path (see @option{--share} and
5191 @option{--expose} respectively) whose target is within the current user's
5192 home directory will be remapped relative to @file{/home/USER}; this
5193 includes the automatic mapping of the current working directory.
5196 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
5198 guix environment --container --user=foo \
5199 --expose=$HOME/test \
5200 --expose=/tmp/target=$HOME/target
5203 While this will limit the leaking of user identity through home paths
5204 and each of the user fields, this is only one useful component of a
5205 broader privacy/anonymity solution---not one in and of itself.
5208 For containers, the default behavior is to share the current working
5209 directory with the isolated container and immediately change to that
5210 directory within the container. If this is undesirable,
5211 @option{--no-cwd} will cause the current working directory to @emph{not}
5212 be automatically shared and will change to the user's home directory
5213 within the container instead. See also @option{--user}.
5215 @item --expose=@var{source}[=@var{target}]
5216 @itemx --share=@var{source}[=@var{target}]
5217 For containers, @option{--expose} (resp. @option{--share}) exposes the
5218 file system @var{source} from the host system as the read-only
5219 (resp. writable) file system @var{target} within the container. If
5220 @var{target} is not specified, @var{source} is used as the target mount
5221 point in the container.
5223 The example below spawns a Guile REPL in a container in which the user's
5224 home directory is accessible read-only via the @file{/exchange}
5228 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
5233 @command{guix environment}
5234 also supports all of the common build options that @command{guix
5235 build} supports (@pxref{Common Build Options}) as well as package
5236 transformation options (@pxref{Package Transformation Options}).
5238 @node Invoking guix pack
5239 @section Invoking @command{guix pack}
5241 Occasionally you want to pass software to people who are not (yet!)
5242 lucky enough to be using Guix. You'd tell them to run @command{guix
5243 package -i @var{something}}, but that's not possible in this case. This
5244 is where @command{guix pack} comes in.
5247 If you are looking for ways to exchange binaries among machines that
5248 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
5249 publish}, and @ref{Invoking guix archive}.
5254 @cindex application bundle
5255 @cindex software bundle
5256 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
5257 @dfn{software bundle}: it creates a tarball or some other archive
5258 containing the binaries of the software you're interested in, and all
5259 its dependencies. The resulting archive can be used on any machine that
5260 does not have Guix, and people can run the exact same binaries as those
5261 you have with Guix. The pack itself is created in a bit-reproducible
5262 fashion, so anyone can verify that it really contains the build results
5263 that you pretend to be shipping.
5265 For example, to create a bundle containing Guile, Emacs, Geiser, and all
5266 their dependencies, you can run:
5269 $ guix pack guile emacs geiser
5271 /gnu/store/@dots{}-pack.tar.gz
5274 The result here is a tarball containing a @file{/gnu/store} directory
5275 with all the relevant packages. The resulting tarball contains a
5276 @dfn{profile} with the three packages of interest; the profile is the
5277 same as would be created by @command{guix package -i}. It is this
5278 mechanism that is used to create Guix's own standalone binary tarball
5279 (@pxref{Binary Installation}).
5281 Users of this pack would have to run
5282 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
5283 find inconvenient. To work around it, you can create, say, a
5284 @file{/opt/gnu/bin} symlink to the profile:
5287 guix pack -S /opt/gnu/bin=bin guile emacs geiser
5291 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
5293 @cindex relocatable binaries, with @command{guix pack}
5294 What if the recipient of your pack does not have root privileges on
5295 their machine, and thus cannot unpack it in the root file system? In
5296 that case, you will want to use the @option{--relocatable} option (see
5297 below). This option produces @dfn{relocatable binaries}, meaning they
5298 they can be placed anywhere in the file system hierarchy: in the example
5299 above, users can unpack your tarball in their home directory and
5300 directly run @file{./opt/gnu/bin/guile}.
5302 @cindex Docker, build an image with guix pack
5303 Alternatively, you can produce a pack in the Docker image format using
5304 the following command:
5307 guix pack -f docker -S /bin=bin guile guile-readline
5311 The result is a tarball that can be passed to the @command{docker load}
5312 command, followed by @code{docker run}:
5315 docker load < @var{file}
5316 docker run -ti guile-guile-readline /bin/guile
5320 where @var{file} is the image returned by @var{guix pack}, and
5321 @code{guile-guile-readline} is its ``image tag''. See the
5322 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5323 documentation} for more information.
5325 @cindex Singularity, build an image with guix pack
5326 @cindex SquashFS, build an image with guix pack
5327 Yet another option is to produce a SquashFS image with the following
5331 guix pack -f squashfs bash guile emacs geiser
5335 The result is a SquashFS file system image that can either be mounted or
5336 directly be used as a file system container image with the
5337 @uref{https://www.sylabs.io/docs/, Singularity container execution
5338 environment}, using commands like @command{singularity shell} or
5339 @command{singularity exec}.
5341 Several command-line options allow you to customize your pack:
5344 @item --format=@var{format}
5345 @itemx -f @var{format}
5346 Produce a pack in the given @var{format}.
5348 The available formats are:
5352 This is the default format. It produces a tarball containing all the
5353 specified binaries and symlinks.
5356 This produces a tarball that follows the
5357 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
5358 Docker Image Specification}. The ``repository name'' as it appears in
5359 the output of the @command{docker images} command is computed from
5360 package names passed on the command line or in the manifest file.
5363 This produces a SquashFS image containing all the specified binaries and
5364 symlinks, as well as empty mount points for virtual file systems like
5368 Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
5369 For that reason, @command{guix pack -f squashfs} always implies @code{-S
5370 /bin=bin}. Thus, your @command{guix pack} invocation must always start
5371 with something like:
5374 guix pack -f squashfs bash @dots{}
5377 If you forget the @code{bash} (or similar) package, @command{singularity
5378 run} and @command{singularity exec} will fail with an unhelpful ``no
5379 such file or directory'' message.
5383 @cindex relocatable binaries
5386 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
5387 anywhere in the file system hierarchy and run from there.
5389 When this option is passed once, the resulting binaries require support for
5390 @dfn{user namespaces} in the kernel Linux; when passed
5391 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
5392 PRoot support, can be thought of as the abbreviation of ``Really
5393 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to
5394 other techniques if user namespaces are unavailable, and essentially
5395 work anywhere---see below for the implications.
5397 For example, if you create a pack containing Bash with:
5400 guix pack -RR -S /mybin=bin bash
5404 ...@: you can copy that pack to a machine that lacks Guix, and from your
5405 home directory as a normal user, run:
5413 In that shell, if you type @code{ls /gnu/store}, you'll notice that
5414 @file{/gnu/store} shows up and contains all the dependencies of
5415 @code{bash}, even though the machine actually lacks @file{/gnu/store}
5416 altogether! That is probably the simplest way to deploy Guix-built
5417 software on a non-Guix machine.
5420 By default, relocatable binaries rely on the @dfn{user namespace} feature of
5421 the kernel Linux, which allows unprivileged users to mount or change root.
5422 Old versions of Linux did not support it, and some GNU/Linux distributions
5425 To produce relocatable binaries that work even in the absence of user
5426 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
5427 case, binaries will try user namespace support and fall back to another
5428 @dfn{execution engine} if user namespaces are not supported. The
5429 following execution engines are supported:
5433 Try user namespaces and fall back to PRoot if user namespaces are not
5434 supported (see below).
5437 Try user namespaces and fall back to Fakechroot if user namespaces are
5438 not supported (see below).
5441 Run the program through user namespaces and abort if they are not
5445 Run through PRoot. The @uref{https://proot-me.github.io/, PRoot} program
5446 provides the necessary
5447 support for file system virtualization. It achieves that by using the
5448 @code{ptrace} system call on the running program. This approach has the
5449 advantage to work without requiring special kernel support, but it incurs
5450 run-time overhead every time a system call is made.
5453 Run through Fakechroot. @uref{https://github.com/dex4er/fakechroot/,
5454 Fakechroot} virtualizes file system accesses by intercepting calls to C
5455 library functions such as @code{open}, @code{stat}, @code{exec}, and so
5456 on. Unlike PRoot, it incurs very little overhead. However, it does not
5457 always work: for example, some file system accesses made from within the
5458 C library are not intercepted, and file system accesses made @i{via}
5459 direct syscalls are not intercepted either, leading to erratic behavior.
5462 @vindex GUIX_EXECUTION_ENGINE
5463 When running a wrapped program, you can explicitly request one of the
5464 execution engines listed above by setting the
5465 @code{GUIX_EXECUTION_ENGINE} environment variable accordingly.
5468 @cindex entry point, for Docker images
5469 @item --entry-point=@var{command}
5470 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
5471 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
5472 support it. @var{command} must be relative to the profile contained in the
5475 The entry point specifies the command that tools like @code{docker run} or
5476 @code{singularity run} automatically start by default. For example, you can
5480 guix pack -f docker --entry-point=bin/guile guile
5483 The resulting pack can easily be loaded and @code{docker run} with no extra
5484 arguments will spawn @code{bin/guile}:
5487 docker load -i pack.tar.gz
5488 docker run @var{image-id}
5491 @item --expression=@var{expr}
5492 @itemx -e @var{expr}
5493 Consider the package @var{expr} evaluates to.
5495 This has the same purpose as the same-named option in @command{guix
5496 build} (@pxref{Additional Build Options, @option{--expression} in
5497 @command{guix build}}).
5499 @item --manifest=@var{file}
5500 @itemx -m @var{file}
5501 Use the packages contained in the manifest object returned by the Scheme
5502 code in @var{file}. This option can be repeated several times, in which
5503 case the manifests are concatenated.
5505 This has a similar purpose as the same-named option in @command{guix
5506 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
5507 same manifest files. It allows you to define a collection of packages
5508 once and use it both for creating profiles and for creating archives
5509 for use on machines that do not have Guix installed. Note that you can
5510 specify @emph{either} a manifest file @emph{or} a list of packages,
5513 @item --system=@var{system}
5514 @itemx -s @var{system}
5515 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
5516 the system type of the build host.
5518 @item --target=@var{triplet}
5519 @cindex cross-compilation
5520 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
5521 as @code{"aarch64-linux-gnu"} (@pxref{Specifying target triplets, GNU
5522 configuration triplets,, autoconf, Autoconf}).
5524 @item --compression=@var{tool}
5525 @itemx -C @var{tool}
5526 Compress the resulting tarball using @var{tool}---one of @code{gzip},
5527 @code{zstd}, @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no
5530 @item --symlink=@var{spec}
5531 @itemx -S @var{spec}
5532 Add the symlinks specified by @var{spec} to the pack. This option can
5533 appear several times.
5535 @var{spec} has the form @code{@var{source}=@var{target}}, where
5536 @var{source} is the symlink that will be created and @var{target} is the
5539 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
5540 symlink pointing to the @file{bin} sub-directory of the profile.
5542 @item --save-provenance
5543 Save provenance information for the packages passed on the command line.
5544 Provenance information includes the URL and commit of the channels in use
5547 Provenance information is saved in the
5548 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
5549 usual package metadata---the name and version of each package, their
5550 propagated inputs, and so on. It is useful information to the recipient of
5551 the pack, who then knows how the pack was (supposedly) obtained.
5553 This option is not enabled by default because, like timestamps, provenance
5554 information contributes nothing to the build process. In other words, there
5555 is an infinity of channel URLs and commit IDs that can lead to the same pack.
5556 Recording such ``silent'' metadata in the output thus potentially breaks the
5557 source-to-binary bitwise reproducibility property.
5559 @item --root=@var{file}
5560 @itemx -r @var{file}
5561 @cindex garbage collector root, for packs
5562 Make @var{file} a symlink to the resulting pack, and register it as a garbage
5565 @item --localstatedir
5566 @itemx --profile-name=@var{name}
5567 Include the ``local state directory'', @file{/var/guix}, in the resulting
5568 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
5569 profile---by default @var{name} is @code{guix-profile}, which corresponds to
5570 @file{~root/.guix-profile}.
5572 @file{/var/guix} contains the store database (@pxref{The Store}) as well
5573 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
5574 the pack means that the store is ``complete'' and manageable by Guix;
5575 not providing it pack means that the store is ``dead'': items cannot be
5576 added to it or removed from it after extraction of the pack.
5578 One use case for this is the Guix self-contained binary tarball
5579 (@pxref{Binary Installation}).
5583 Print the name of the derivation that builds the pack.
5586 Use the bootstrap binaries to build the pack. This option is only
5587 useful to Guix developers.
5590 In addition, @command{guix pack} supports all the common build options
5591 (@pxref{Common Build Options}) and all the package transformation
5592 options (@pxref{Package Transformation Options}).
5595 @node The GCC toolchain
5596 @section The GCC toolchain
5600 @cindex linker wrapper
5601 @cindex toolchain, for C development
5602 @cindex toolchain, for Fortran development
5604 If you need a complete toolchain for compiling and linking C or C++
5605 source code, use the @code{gcc-toolchain} package. This package
5606 provides a complete GCC toolchain for C/C++ development, including GCC
5607 itself, the GNU C Library (headers and binaries, plus debugging symbols
5608 in the @code{debug} output), Binutils, and a linker wrapper.
5610 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
5611 passed to the linker, add corresponding @code{-rpath} arguments, and
5612 invoke the actual linker with this new set of arguments. You can instruct the
5613 wrapper to refuse to link against libraries not in the store by setting the
5614 @env{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
5616 The package @code{gfortran-toolchain} provides a complete GCC toolchain
5617 for Fortran development. For other languages, please use
5618 @samp{guix search gcc toolchain} (@pxref{guix-search,, Invoking guix package}).
5621 @node Invoking guix git authenticate
5622 @section Invoking @command{guix git authenticate}
5624 The @command{guix git authenticate} command authenticates a Git checkout
5625 following the same rule as for channels (@pxref{channel-authentication,
5626 channel authentication}). That is, starting from a given commit, it
5627 ensures that all subsequent commits are signed by an OpenPGP key whose
5628 fingerprint appears in the @file{.guix-authorizations} file of its
5631 You will find this command useful if you maintain a channel. But in
5632 fact, this authentication mechanism is useful in a broader context, so
5633 you might want to use it for Git repositories that have nothing to do
5636 The general syntax is:
5639 guix git authenticate @var{commit} @var{signer} [@var{options}@dots{}]
5642 By default, this command authenticates the Git checkout in the current
5643 directory; it outputs nothing and exits with exit code zero on success
5644 and non-zero on failure. @var{commit} above denotes the first commit
5645 where authentication takes place, and @var{signer} is the OpenPGP
5646 fingerprint of public key used to sign @var{commit}. Together, they
5647 form a ``channel introduction'' (@pxref{channel-authentication, channel
5648 introduction}). The options below allow you to fine-tune the process.
5651 @item --repository=@var{directory}
5652 @itemx -r @var{directory}
5653 Open the Git repository in @var{directory} instead of the current
5656 @item --keyring=@var{reference}
5657 @itemx -k @var{reference}
5658 Load OpenPGP keyring from @var{reference}, the reference of a branch
5659 such as @code{origin/keyring} or @code{my-keyring}. The branch must
5660 contain OpenPGP public keys in @file{.key} files, either in binary form
5661 or ``ASCII-armored''. By default the keyring is loaded from the branch
5662 named @code{keyring}.
5665 Display commit signing statistics upon completion.
5667 @item --cache-key=@var{key}
5668 Previously-authenticated commits are cached in a file under
5669 @file{~/.cache/guix/authentication}. This option forces the cache to be
5670 stored in file @var{key} in that directory.
5672 @item --historical-authorizations=@var{file}
5673 By default, any commit whose parent commit(s) lack the
5674 @file{.guix-authorizations} file is considered inauthentic. In
5675 contrast, this option considers the authorizations in @var{file} for any
5676 commit that lacks @file{.guix-authorizations}. The format of @var{file}
5677 is the same as that of @file{.guix-authorizations}
5678 (@pxref{channel-authorizations, @file{.guix-authorizations} format}).
5682 @c *********************************************************************
5683 @node Programming Interface
5684 @chapter Programming Interface
5686 GNU Guix provides several Scheme programming interfaces (APIs) to
5687 define, build, and query packages. The first interface allows users to
5688 write high-level package definitions. These definitions refer to
5689 familiar packaging concepts, such as the name and version of a package,
5690 its build system, and its dependencies. These definitions can then be
5691 turned into concrete build actions.
5693 Build actions are performed by the Guix daemon, on behalf of users. In a
5694 standard setup, the daemon has write access to the store---the
5695 @file{/gnu/store} directory---whereas users do not. The recommended
5696 setup also has the daemon perform builds in chroots, under specific
5697 build users, to minimize interference with the rest of the system.
5700 Lower-level APIs are available to interact with the daemon and the
5701 store. To instruct the daemon to perform a build action, users actually
5702 provide it with a @dfn{derivation}. A derivation is a low-level
5703 representation of the build actions to be taken, and the environment in
5704 which they should occur---derivations are to package definitions what
5705 assembly is to C programs. The term ``derivation'' comes from the fact
5706 that build results @emph{derive} from them.
5708 This chapter describes all these APIs in turn, starting from high-level
5709 package definitions.
5712 * Package Modules:: Packages from the programmer's viewpoint.
5713 * Defining Packages:: Defining new packages.
5714 * Build Systems:: Specifying how packages are built.
5715 * The Store:: Manipulating the package store.
5716 * Derivations:: Low-level interface to package derivations.
5717 * The Store Monad:: Purely functional interface to the store.
5718 * G-Expressions:: Manipulating build expressions.
5719 * Invoking guix repl:: Programming Guix in Guile
5722 @node Package Modules
5723 @section Package Modules
5725 From a programming viewpoint, the package definitions of the
5726 GNU distribution are provided by Guile modules in the @code{(gnu packages
5727 @dots{})} name space@footnote{Note that packages under the @code{(gnu
5728 packages @dots{})} module name space are not necessarily ``GNU
5729 packages''. This module naming scheme follows the usual Guile module
5730 naming convention: @code{gnu} means that these modules are distributed
5731 as part of the GNU system, and @code{packages} identifies modules that
5732 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5733 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5734 module exports a variable named @code{emacs}, which is bound to a
5735 @code{<package>} object (@pxref{Defining Packages}).
5737 The @code{(gnu packages @dots{})} module name space is
5738 automatically scanned for packages by the command-line tools. For
5739 instance, when running @code{guix install emacs}, all the @code{(gnu
5740 packages @dots{})} modules are scanned until one that exports a package
5741 object whose name is @code{emacs} is found. This package search
5742 facility is implemented in the @code{(gnu packages)} module.
5744 @cindex customization, of packages
5745 @cindex package module search path
5746 Users can store package definitions in modules with different
5747 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
5748 name and module name must match. For instance, the @code{(my-packages
5749 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
5750 relative to the load path specified with @option{--load-path} or
5751 @env{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
5752 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
5753 these package definitions visible to the user interfaces:
5757 By adding the directory containing your package modules to the search path
5758 with the @code{-L} flag of @command{guix package} and other commands
5759 (@pxref{Common Build Options}), or by setting the @env{GUIX_PACKAGE_PATH}
5760 environment variable described below.
5763 By defining a @dfn{channel} and configuring @command{guix pull} so that it
5764 pulls from it. A channel is essentially a Git repository containing package
5765 modules. @xref{Channels}, for more information on how to define and use
5769 @env{GUIX_PACKAGE_PATH} works similarly to other search path variables:
5771 @defvr {Environment Variable} GUIX_PACKAGE_PATH
5772 This is a colon-separated list of directories to search for additional
5773 package modules. Directories listed in this variable take precedence
5774 over the own modules of the distribution.
5777 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
5778 each package is built based solely on other packages in the
5779 distribution. The root of this dependency graph is a small set of
5780 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
5781 bootstrap)} module. For more information on bootstrapping,
5782 @pxref{Bootstrapping}.
5784 @node Defining Packages
5785 @section Defining Packages
5787 The high-level interface to package definitions is implemented in the
5788 @code{(guix packages)} and @code{(guix build-system)} modules. As an
5789 example, the package definition, or @dfn{recipe}, for the GNU Hello
5790 package looks like this:
5793 (define-module (gnu packages hello)
5794 #:use-module (guix packages)
5795 #:use-module (guix download)
5796 #:use-module (guix build-system gnu)
5797 #:use-module (guix licenses)
5798 #:use-module (gnu packages gawk))
5800 (define-public hello
5806 (uri (string-append "mirror://gnu/hello/hello-" version
5810 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
5811 (build-system gnu-build-system)
5812 (arguments '(#:configure-flags '("--enable-silent-rules")))
5813 (inputs `(("gawk" ,gawk)))
5814 (synopsis "Hello, GNU world: An example GNU package")
5815 (description "Guess what GNU Hello prints!")
5816 (home-page "https://www.gnu.org/software/hello/")
5821 Without being a Scheme expert, the reader may have guessed the meaning
5822 of the various fields here. This expression binds the variable
5823 @code{hello} to a @code{<package>} object, which is essentially a record
5824 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
5825 This package object can be inspected using procedures found in the
5826 @code{(guix packages)} module; for instance, @code{(package-name hello)}
5827 returns---surprise!---@code{"hello"}.
5829 With luck, you may be able to import part or all of the definition of
5830 the package you are interested in from another repository, using the
5831 @code{guix import} command (@pxref{Invoking guix import}).
5833 In the example above, @var{hello} is defined in a module of its own,
5834 @code{(gnu packages hello)}. Technically, this is not strictly
5835 necessary, but it is convenient to do so: all the packages defined in
5836 modules under @code{(gnu packages @dots{})} are automatically known to
5837 the command-line tools (@pxref{Package Modules}).
5839 There are a few points worth noting in the above package definition:
5843 The @code{source} field of the package is an @code{<origin>} object
5844 (@pxref{origin Reference}, for the complete reference).
5845 Here, the @code{url-fetch} method from @code{(guix download)} is used,
5846 meaning that the source is a file to be downloaded over FTP or HTTP.
5848 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
5849 the GNU mirrors defined in @code{(guix download)}.
5851 The @code{sha256} field specifies the expected SHA256 hash of the file
5852 being downloaded. It is mandatory, and allows Guix to check the
5853 integrity of the file. The @code{(base32 @dots{})} form introduces the
5854 base32 representation of the hash. You can obtain this information with
5855 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
5856 hash} (@pxref{Invoking guix hash}).
5859 When needed, the @code{origin} form can also have a @code{patches} field
5860 listing patches to be applied, and a @code{snippet} field giving a
5861 Scheme expression to modify the source code.
5864 @cindex GNU Build System
5865 The @code{build-system} field specifies the procedure to build the
5866 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
5867 represents the familiar GNU Build System, where packages may be
5868 configured, built, and installed with the usual @code{./configure &&
5869 make && make check && make install} command sequence.
5872 The @code{arguments} field specifies options for the build system
5873 (@pxref{Build Systems}). Here it is interpreted by
5874 @var{gnu-build-system} as a request run @file{configure} with the
5875 @option{--enable-silent-rules} flag.
5881 What about these quote (@code{'}) characters? They are Scheme syntax to
5882 introduce a literal list; @code{'} is synonymous with @code{quote}.
5883 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
5884 for details. Here the value of the @code{arguments} field is a list of
5885 arguments passed to the build system down the road, as with @code{apply}
5886 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
5889 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
5890 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
5891 @code{#:configure-flags} is a keyword used to pass a keyword argument
5892 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
5896 The @code{inputs} field specifies inputs to the build process---i.e.,
5897 build-time or run-time dependencies of the package. Here, we define an
5898 input called @code{"gawk"} whose value is that of the @var{gawk}
5899 variable; @var{gawk} is itself bound to a @code{<package>} object.
5901 @cindex backquote (quasiquote)
5904 @cindex comma (unquote)
5908 @findex unquote-splicing
5909 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
5910 us to introduce a literal list in the @code{inputs} field, while
5911 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
5912 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
5915 Note that GCC, Coreutils, Bash, and other essential tools do not need to
5916 be specified as inputs here. Instead, @var{gnu-build-system} takes care
5917 of ensuring that they are present (@pxref{Build Systems}).
5919 However, any other dependencies need to be specified in the
5920 @code{inputs} field. Any dependency not specified here will simply be
5921 unavailable to the build process, possibly leading to a build failure.
5924 @xref{package Reference}, for a full description of possible fields.
5926 Once a package definition is in place, the
5927 package may actually be built using the @code{guix build} command-line
5928 tool (@pxref{Invoking guix build}), troubleshooting any build failures
5929 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
5930 package definition using the @command{guix edit} command
5931 (@pxref{Invoking guix edit}).
5932 @xref{Packaging Guidelines}, for
5933 more information on how to test package definitions, and
5934 @ref{Invoking guix lint}, for information on how to check a definition
5935 for style conformance.
5936 @vindex GUIX_PACKAGE_PATH
5937 Lastly, @pxref{Channels}, for information
5938 on how to extend the distribution by adding your own package definitions
5941 Finally, updating the package definition to a new upstream version
5942 can be partly automated by the @command{guix refresh} command
5943 (@pxref{Invoking guix refresh}).
5945 Behind the scenes, a derivation corresponding to the @code{<package>}
5946 object is first computed by the @code{package-derivation} procedure.
5947 That derivation is stored in a @file{.drv} file under @file{/gnu/store}.
5948 The build actions it prescribes may then be realized by using the
5949 @code{build-derivations} procedure (@pxref{The Store}).
5951 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
5952 Return the @code{<derivation>} object of @var{package} for @var{system}
5953 (@pxref{Derivations}).
5955 @var{package} must be a valid @code{<package>} object, and @var{system}
5956 must be a string denoting the target system type---e.g.,
5957 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
5958 must be a connection to the daemon, which operates on the store
5959 (@pxref{The Store}).
5963 @cindex cross-compilation
5964 Similarly, it is possible to compute a derivation that cross-builds a
5965 package for some other system:
5967 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
5968 @var{package} @var{target} [@var{system}]
5969 Return the @code{<derivation>} object of @var{package} cross-built from
5970 @var{system} to @var{target}.
5972 @var{target} must be a valid GNU triplet denoting the target hardware
5973 and operating system, such as @code{"aarch64-linux-gnu"}
5974 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
5977 @cindex package transformations
5978 @cindex input rewriting
5979 @cindex dependency tree rewriting
5980 Packages can be manipulated in arbitrary ways. An example of a useful
5981 transformation is @dfn{input rewriting}, whereby the dependency tree of
5982 a package is rewritten by replacing specific inputs by others:
5984 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
5985 [@var{rewrite-name}]
5986 Return a procedure that, when passed a package, replaces its direct and
5987 indirect dependencies (but not its implicit inputs) according to
5988 @var{replacements}. @var{replacements} is a list of package pairs; the
5989 first element of each pair is the package to replace, and the second one
5992 Optionally, @var{rewrite-name} is a one-argument procedure that takes
5993 the name of a package and returns its new name after rewrite.
5997 Consider this example:
6000 (define libressl-instead-of-openssl
6001 ;; This is a procedure to replace OPENSSL by LIBRESSL,
6003 (package-input-rewriting `((,openssl . ,libressl))))
6005 (define git-with-libressl
6006 (libressl-instead-of-openssl git))
6010 Here we first define a rewriting procedure that replaces @var{openssl}
6011 with @var{libressl}. Then we use it to define a @dfn{variant} of the
6012 @var{git} package that uses @var{libressl} instead of @var{openssl}.
6013 This is exactly what the @option{--with-input} command-line option does
6014 (@pxref{Package Transformation Options, @option{--with-input}}).
6016 The following variant of @code{package-input-rewriting} can match packages to
6017 be replaced by name rather than by identity.
6019 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
6020 Return a procedure that, given a package, applies the given @var{replacements} to
6021 all the package graph (excluding implicit inputs). @var{replacements} is a list of
6022 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
6023 @code{"guile@@2"}, and each procedure takes a matching package and returns a
6024 replacement for that package.
6027 The example above could be rewritten this way:
6030 (define libressl-instead-of-openssl
6031 ;; Replace all the packages called "openssl" with LibreSSL.
6032 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
6035 The key difference here is that, this time, packages are matched by spec and
6036 not by identity. In other words, any package in the graph that is called
6037 @code{openssl} will be replaced.
6039 A more generic procedure to rewrite a package dependency graph is
6040 @code{package-mapping}: it supports arbitrary changes to nodes in the
6043 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
6044 Return a procedure that, given a package, applies @var{proc} to all the packages
6045 depended on and returns the resulting package. The procedure stops recursion
6046 when @var{cut?} returns true for a given package.
6050 * package Reference:: The package data type.
6051 * origin Reference:: The origin data type.
6055 @node package Reference
6056 @subsection @code{package} Reference
6058 This section summarizes all the options available in @code{package}
6059 declarations (@pxref{Defining Packages}).
6061 @deftp {Data Type} package
6062 This is the data type representing a package recipe.
6066 The name of the package, as a string.
6068 @item @code{version}
6069 The version of the package, as a string.
6072 An object telling how the source code for the package should be
6073 acquired. Most of the time, this is an @code{origin} object, which
6074 denotes a file fetched from the Internet (@pxref{origin Reference}). It
6075 can also be any other ``file-like'' object such as a @code{local-file},
6076 which denotes a file from the local file system (@pxref{G-Expressions,
6077 @code{local-file}}).
6079 @item @code{build-system}
6080 The build system that should be used to build the package (@pxref{Build
6083 @item @code{arguments} (default: @code{'()})
6084 The arguments that should be passed to the build system. This is a
6085 list, typically containing sequential keyword-value pairs.
6087 @item @code{inputs} (default: @code{'()})
6088 @itemx @code{native-inputs} (default: @code{'()})
6089 @itemx @code{propagated-inputs} (default: @code{'()})
6090 @cindex inputs, of packages
6091 These fields list dependencies of the package. Each one is a list of
6092 tuples, where each tuple has a label for the input (a string) as its
6093 first element, a package, origin, or derivation as its second element,
6094 and optionally the name of the output thereof that should be used, which
6095 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
6096 more on package outputs). For example, the list below specifies three
6100 `(("libffi" ,libffi)
6101 ("libunistring" ,libunistring)
6102 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
6105 @cindex cross compilation, package dependencies
6106 The distinction between @code{native-inputs} and @code{inputs} is
6107 necessary when considering cross-compilation. When cross-compiling,
6108 dependencies listed in @code{inputs} are built for the @emph{target}
6109 architecture; conversely, dependencies listed in @code{native-inputs}
6110 are built for the architecture of the @emph{build} machine.
6112 @code{native-inputs} is typically used to list tools needed at
6113 build time, but not at run time, such as Autoconf, Automake, pkg-config,
6114 Gettext, or Bison. @command{guix lint} can report likely mistakes in
6115 this area (@pxref{Invoking guix lint}).
6117 @anchor{package-propagated-inputs}
6118 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
6119 specified packages will be automatically installed alongside the package
6120 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
6121 package}}, for information on how @command{guix package} deals with
6124 For example this is necessary when a C/C++ library needs headers of
6125 another library to compile, or when a pkg-config file refers to another
6126 one @i{via} its @code{Requires} field.
6128 Another example where @code{propagated-inputs} is useful is for languages
6129 that lack a facility to record the run-time search path akin to the
6130 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
6131 more. To ensure that libraries written in those languages can find
6132 library code they depend on at run time, run-time dependencies must be
6133 listed in @code{propagated-inputs} rather than @code{inputs}.
6135 @item @code{outputs} (default: @code{'("out")})
6136 The list of output names of the package. @xref{Packages with Multiple
6137 Outputs}, for typical uses of additional outputs.
6139 @item @code{native-search-paths} (default: @code{'()})
6140 @itemx @code{search-paths} (default: @code{'()})
6141 A list of @code{search-path-specification} objects describing
6142 search-path environment variables honored by the package.
6144 @item @code{replacement} (default: @code{#f})
6145 This must be either @code{#f} or a package object that will be used as a
6146 @dfn{replacement} for this package. @xref{Security Updates, grafts},
6149 @item @code{synopsis}
6150 A one-line description of the package.
6152 @item @code{description}
6153 A more elaborate description of the package.
6155 @item @code{license}
6156 @cindex license, of packages
6157 The license of the package; a value from @code{(guix licenses)},
6158 or a list of such values.
6160 @item @code{home-page}
6161 The URL to the home-page of the package, as a string.
6163 @item @code{supported-systems} (default: @code{%supported-systems})
6164 The list of systems supported by the package, as strings of the form
6165 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
6167 @item @code{location} (default: source location of the @code{package} form)
6168 The source location of the package. It is useful to override this when
6169 inheriting from another package, in which case this field is not
6170 automatically corrected.
6174 @deffn {Scheme Syntax} this-package
6175 When used in the @emph{lexical scope} of a package field definition, this
6176 identifier resolves to the package being defined.
6178 The example below shows how to add a package as a native input of itself when
6186 ;; When cross-compiled, Guile, for example, depends on
6187 ;; a native version of itself. Add it here.
6188 (native-inputs (if (%current-target-system)
6189 `(("self" ,this-package))
6193 It is an error to refer to @code{this-package} outside a package definition.
6196 @node origin Reference
6197 @subsection @code{origin} Reference
6199 This section summarizes all the options available in @code{origin}
6200 declarations (@pxref{Defining Packages}).
6202 @deftp {Data Type} origin
6203 This is the data type representing a source code origin.
6207 An object containing the URI of the source. The object type depends on
6208 the @code{method} (see below). For example, when using the
6209 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
6210 values are: a URL represented as a string, or a list thereof.
6213 A procedure that handles the URI.
6218 @item @var{url-fetch} from @code{(guix download)}
6219 download a file from the HTTP, HTTPS, or FTP URL specified in the
6223 @item @var{git-fetch} from @code{(guix git-download)}
6224 clone the Git version control repository, and check out the revision
6225 specified in the @code{uri} field as a @code{git-reference} object; a
6226 @code{git-reference} looks like this:
6230 (url "https://git.savannah.gnu.org/git/hello.git")
6236 A bytevector containing the SHA-256 hash of the source. This is
6237 equivalent to providing a @code{content-hash} SHA256 object in the
6238 @code{hash} field described below.
6241 The @code{content-hash} object of the source---see below for how to use
6242 @code{content-hash}.
6244 You can obtain this information using @code{guix download}
6245 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
6248 @item @code{file-name} (default: @code{#f})
6249 The file name under which the source code should be saved. When this is
6250 @code{#f}, a sensible default value will be used in most cases. In case
6251 the source is fetched from a URL, the file name from the URL will be
6252 used. For version control checkouts, it is recommended to provide the
6253 file name explicitly because the default is not very descriptive.
6255 @item @code{patches} (default: @code{'()})
6256 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
6257 file-like objects}) pointing to patches to be applied to the source.
6259 This list of patches must be unconditional. In particular, it cannot
6260 depend on the value of @code{%current-system} or
6261 @code{%current-target-system}.
6263 @item @code{snippet} (default: @code{#f})
6264 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
6265 in the source directory. This is a convenient way to modify the source,
6266 sometimes more convenient than a patch.
6268 @item @code{patch-flags} (default: @code{'("-p1")})
6269 A list of command-line flags that should be passed to the @code{patch}
6272 @item @code{patch-inputs} (default: @code{#f})
6273 Input packages or derivations to the patching process. When this is
6274 @code{#f}, the usual set of inputs necessary for patching are provided,
6275 such as GNU@tie{}Patch.
6277 @item @code{modules} (default: @code{'()})
6278 A list of Guile modules that should be loaded during the patching
6279 process and while running the code in the @code{snippet} field.
6281 @item @code{patch-guile} (default: @code{#f})
6282 The Guile package that should be used in the patching process. When
6283 this is @code{#f}, a sensible default is used.
6287 @deftp {Data Type} content-hash @var{value} [@var{algorithm}]
6288 Construct a content hash object for the given @var{algorithm}, and with
6289 @var{value} as its hash value. When @var{algorithm} is omitted, assume
6290 it is @code{sha256}.
6292 @var{value} can be a literal string, in which case it is base32-decoded,
6293 or it can be a bytevector.
6295 The following forms are all equivalent:
6298 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj")
6299 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"
6301 (content-hash (base32
6302 "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"))
6303 (content-hash (base64 "kkb+RPaP7uyMZmu4eXPVkM4BN8yhRd8BTHLslb6f/Rc=")
6307 Technically, @code{content-hash} is currently implemented as a macro.
6308 It performs sanity checks at macro-expansion time, when possible, such
6309 as ensuring that @var{value} has the right size for @var{algorithm}.
6313 @section Build Systems
6315 @cindex build system
6316 Each package definition specifies a @dfn{build system} and arguments for
6317 that build system (@pxref{Defining Packages}). This @code{build-system}
6318 field represents the build procedure of the package, as well as implicit
6319 dependencies of that build procedure.
6321 Build systems are @code{<build-system>} objects. The interface to
6322 create and manipulate them is provided by the @code{(guix build-system)}
6323 module, and actual build systems are exported by specific modules.
6325 @cindex bag (low-level package representation)
6326 Under the hood, build systems first compile package objects to
6327 @dfn{bags}. A @dfn{bag} is like a package, but with less
6328 ornamentation---in other words, a bag is a lower-level representation of
6329 a package, which includes all the inputs of that package, including some
6330 that were implicitly added by the build system. This intermediate
6331 representation is then compiled to a derivation (@pxref{Derivations}).
6333 Build systems accept an optional list of @dfn{arguments}. In package
6334 definitions, these are passed @i{via} the @code{arguments} field
6335 (@pxref{Defining Packages}). They are typically keyword arguments
6336 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
6337 Guile Reference Manual}). The value of these arguments is usually
6338 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
6339 by the daemon (@pxref{Derivations}).
6341 The main build system is @code{gnu-build-system}, which implements the
6342 standard build procedure for GNU and many other packages. It
6343 is provided by the @code{(guix build-system gnu)} module.
6345 @defvr {Scheme Variable} gnu-build-system
6346 @code{gnu-build-system} represents the GNU Build System, and variants
6347 thereof (@pxref{Configuration, configuration and makefile conventions,,
6348 standards, GNU Coding Standards}).
6350 @cindex build phases
6351 In a nutshell, packages using it are configured, built, and installed with
6352 the usual @code{./configure && make && make check && make install}
6353 command sequence. In practice, a few additional steps are often needed.
6354 All these steps are split up in separate @dfn{phases},
6355 notably@footnote{Please see the @code{(guix build gnu-build-system)}
6356 modules for more details about the build phases.}:
6360 Unpack the source tarball, and change the current directory to the
6361 extracted source tree. If the source is actually a directory, copy it
6362 to the build tree, and enter that directory.
6364 @item patch-source-shebangs
6365 Patch shebangs encountered in source files so they refer to the right
6366 store file names. For instance, this changes @code{#!/bin/sh} to
6367 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
6370 Run the @file{configure} script with a number of default options, such
6371 as @option{--prefix=/gnu/store/@dots{}}, as well as the options specified
6372 by the @code{#:configure-flags} argument.
6375 Run @code{make} with the list of flags specified with
6376 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
6377 (the default), build with @code{make -j}.
6380 Run @code{make check}, or some other target specified with
6381 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
6382 @code{#:parallel-tests?} argument is true (the default), run @code{make
6386 Run @code{make install} with the flags listed in @code{#:make-flags}.
6388 @item patch-shebangs
6389 Patch shebangs on the installed executable files.
6392 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
6393 is false), copying them to the @code{debug} output when available
6394 (@pxref{Installing Debugging Files}).
6397 @vindex %standard-phases
6398 The build-side module @code{(guix build gnu-build-system)} defines
6399 @code{%standard-phases} as the default list of build phases.
6400 @code{%standard-phases} is a list of symbol/procedure pairs, where the
6401 procedure implements the actual phase.
6403 The list of phases used for a particular package can be changed with the
6404 @code{#:phases} parameter. For instance, passing:
6407 #:phases (modify-phases %standard-phases (delete 'configure))
6410 means that all the phases described above will be used, except the
6411 @code{configure} phase.
6413 In addition, this build system ensures that the ``standard'' environment
6414 for GNU packages is available. This includes tools such as GCC, libc,
6415 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
6416 build-system gnu)} module for a complete list). We call these the
6417 @dfn{implicit inputs} of a package, because package definitions do not
6418 have to mention them.
6421 Other @code{<build-system>} objects are defined to support other
6422 conventions and tools used by free software packages. They inherit most
6423 of @code{gnu-build-system}, and differ mainly in the set of inputs
6424 implicitly added to the build process, and in the list of phases
6425 executed. Some of these build systems are listed below.
6427 @defvr {Scheme Variable} ant-build-system
6428 This variable is exported by @code{(guix build-system ant)}. It
6429 implements the build procedure for Java packages that can be built with
6430 @url{https://ant.apache.org/, Ant build tool}.
6432 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
6433 provided by the @code{icedtea} package to the set of inputs. Different
6434 packages can be specified with the @code{#:ant} and @code{#:jdk}
6435 parameters, respectively.
6437 When the original package does not provide a suitable Ant build file,
6438 the parameter @code{#:jar-name} can be used to generate a minimal Ant
6439 build file @file{build.xml} with tasks to build the specified jar
6440 archive. In this case the parameter @code{#:source-dir} can be used to
6441 specify the source sub-directory, defaulting to ``src''.
6443 The @code{#:main-class} parameter can be used with the minimal ant
6444 buildfile to specify the main class of the resulting jar. This makes the
6445 jar file executable. The @code{#:test-include} parameter can be used to
6446 specify the list of junit tests to run. It defaults to
6447 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
6448 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
6449 because abstract classes cannot be run as tests.
6451 The parameter @code{#:build-target} can be used to specify the Ant task
6452 that should be run during the @code{build} phase. By default the
6453 ``jar'' task will be run.
6457 @defvr {Scheme Variable} android-ndk-build-system
6458 @cindex Android distribution
6459 @cindex Android NDK build system
6460 This variable is exported by @code{(guix build-system android-ndk)}. It
6461 implements a build procedure for Android NDK (native development kit)
6462 packages using a Guix-specific build process.
6464 The build system assumes that packages install their public interface
6465 (header) files to the subdirectory @file{include} of the @code{out} output and
6466 their libraries to the subdirectory @file{lib} the @code{out} output.
6468 It's also assumed that the union of all the dependencies of a package
6469 has no conflicting files.
6471 For the time being, cross-compilation is not supported - so right now
6472 the libraries and header files are assumed to be host tools.
6476 @defvr {Scheme Variable} asdf-build-system/source
6477 @defvrx {Scheme Variable} asdf-build-system/sbcl
6478 @defvrx {Scheme Variable} asdf-build-system/ecl
6480 These variables, exported by @code{(guix build-system asdf)}, implement
6481 build procedures for Common Lisp packages using
6482 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
6483 definition facility for Common Lisp programs and libraries.
6485 The @code{asdf-build-system/source} system installs the packages in
6486 source form, and can be loaded using any common lisp implementation, via
6487 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
6488 systems in the format which a particular implementation understands.
6489 These build systems can also be used to produce executable programs, or
6490 lisp images which contain a set of packages pre-loaded.
6492 The build system uses naming conventions. For binary packages, the
6493 package name should be prefixed with the lisp implementation, such as
6494 @code{sbcl-} for @code{asdf-build-system/sbcl}.
6496 Additionally, the corresponding source package should be labeled using
6497 the same convention as python packages (see @ref{Python Modules}), using
6498 the @code{cl-} prefix.
6500 For binary packages, each system should be defined as a Guix package.
6501 If one package @code{origin} contains several systems, package variants
6502 can be created in order to build all the systems. Source packages,
6503 which use @code{asdf-build-system/source}, may contain several systems.
6505 In order to create executable programs and images, the build-side
6506 procedures @code{build-program} and @code{build-image} can be used.
6507 They should be called in a build phase after the @code{create-symlinks}
6508 phase, so that the system which was just built can be used within the
6509 resulting image. @code{build-program} requires a list of Common Lisp
6510 expressions to be passed as the @code{#:entry-program} argument.
6512 If the system is not defined within its own @file{.asd} file of the same
6513 name, then the @code{#:asd-file} parameter should be used to specify
6514 which file the system is defined in. Furthermore, if the package
6515 defines a system for its tests in a separate file, it will be loaded
6516 before the tests are run if it is specified by the
6517 @code{#:test-asd-file} parameter. If it is not set, the files
6518 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
6519 and @code{test.asd} will be tried if they exist.
6521 If for some reason the package must be named in a different way than the
6522 naming conventions suggest, the @code{#:asd-system-name} parameter can
6523 be used to specify the name of the system.
6527 @defvr {Scheme Variable} cargo-build-system
6528 @cindex Rust programming language
6529 @cindex Cargo (Rust build system)
6530 This variable is exported by @code{(guix build-system cargo)}. It
6531 supports builds of packages using Cargo, the build tool of the
6532 @uref{https://www.rust-lang.org, Rust programming language}.
6534 It adds @code{rustc} and @code{cargo} to the set of inputs.
6535 A different Rust package can be specified with the @code{#:rust} parameter.
6537 Regular cargo dependencies should be added to the package definition via the
6538 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
6539 spec can be a package or a source definition. Note that the spec must
6540 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
6541 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
6542 should be added to the package definition via the
6543 @code{#:cargo-development-inputs} parameter.
6545 In its @code{configure} phase, this build system will make any source inputs
6546 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
6547 parameters available to cargo. It will also remove an included
6548 @code{Cargo.lock} file to be recreated by @code{cargo} during the
6549 @code{build} phase. The @code{install} phase installs any crate the binaries
6550 if they are defined by the crate.
6554 @defvr {Scheme Variable} copy-build-system
6555 This variable is exported by @code{(guix build-system copy)}. It
6556 supports builds of simple packages that don't require much compiling,
6557 mostly just moving files around.
6559 It adds much of the @code{gnu-build-system} packages to the set of
6560 inputs. Because of this, the @code{copy-build-system} does not require
6561 all the boilerplate code often needed for the
6562 @code{trivial-build-system}.
6564 To further simplify the file installation process, an
6565 @code{#:install-plan} argument is exposed to let the packager specify
6566 which files go where. The install plan is a list of @code{(@var{source}
6567 @var{target} [@var{filters}])}. @var{filters} are optional.
6570 @item When @var{source} matches a file or directory without trailing slash, install it to @var{target}.
6572 @item If @var{target} has a trailing slash, install @var{source} basename beneath @var{target}.
6573 @item Otherwise install @var{source} as @var{target}.
6576 @item When @var{source} is a directory with a trailing slash, or when @var{filters} are used,
6577 the trailing slash of @var{target} is implied with the same meaning
6580 @item Without @var{filters}, install the full @var{source} @emph{content} to @var{target}.
6581 @item With @var{filters} among @code{#:include}, @code{#:include-regexp}, @code{#:exclude},
6582 @code{#:exclude-regexp}, only select files are installed depending on
6583 the filters. Each filters is specified by a list of strings.
6585 @item With @code{#:include}, install all the files which the path suffix matches
6586 at least one of the elements in the given list.
6587 @item With @code{#:include-regexp}, install all the files which the
6588 subpaths match at least one of the regular expressions in the given
6590 @item The @code{#:exclude} and @code{#:exclude-regexp} filters
6591 are the complement of their inclusion counterpart. Without @code{#:include} flags,
6592 install all files but those matching the exclusion filters.
6593 If both inclusions and exclusions are specified, the exclusions are done
6594 on top of the inclusions.
6597 In all cases, the paths relative to @var{source} are preserved within
6604 @item @code{("foo/bar" "share/my-app/")}: Install @file{bar} to @file{share/my-app/bar}.
6605 @item @code{("foo/bar" "share/my-app/baz")}: Install @file{bar} to @file{share/my-app/baz}.
6606 @item @code{("foo/" "share/my-app")}: Install the content of @file{foo} inside @file{share/my-app},
6607 e.g., install @file{foo/sub/file} to @file{share/my-app/sub/file}.
6608 @item @code{("foo/" "share/my-app" #:include ("sub/file"))}: Install only @file{foo/sub/file} to
6609 @file{share/my-app/sub/file}.
6610 @item @code{("foo/sub" "share/my-app" #:include ("file"))}: Install @file{foo/sub/file} to
6611 @file{share/my-app/file}.
6616 @cindex Clojure (programming language)
6617 @cindex simple Clojure build system
6618 @defvr {Scheme Variable} clojure-build-system
6619 This variable is exported by @code{(guix build-system clojure)}. It implements
6620 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
6621 using plain old @code{compile} in Clojure. Cross-compilation is not supported
6624 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
6625 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
6626 @code{#:zip} parameters, respectively.
6628 A list of source directories, test directories and jar names can be specified
6629 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
6630 parameters, respectively. Compile directory and main class can be specified
6631 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
6632 Other parameters are documented below.
6634 This build system is an extension of @code{ant-build-system}, but with the
6635 following phases changed:
6640 This phase calls @code{compile} in Clojure to compile source files and runs
6641 @command{jar} to create jars from both source files and compiled files
6642 according to the include list and exclude list specified in
6643 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
6644 has priority over the include list. These lists consist of symbols
6645 representing Clojure libraries or the special keyword @code{#:all} representing
6646 all Clojure libraries found under the source directories. The parameter
6647 @code{#:omit-source?} decides if source should be included into the jars.
6650 This phase runs tests according to the include list and exclude list specified
6651 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
6652 meanings are analogous to that of @code{#:aot-include} and
6653 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
6654 stands for all Clojure libraries found under the test directories. The
6655 parameter @code{#:tests?} decides if tests should be run.
6658 This phase installs all jars built previously.
6661 Apart from the above, this build system also contains an additional phase:
6666 This phase installs all top-level files with base name matching
6667 @code{%doc-regex}. A different regex can be specified with the
6668 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
6669 directories specified in @code{#:doc-dirs} are installed as well.
6673 @defvr {Scheme Variable} cmake-build-system
6674 This variable is exported by @code{(guix build-system cmake)}. It
6675 implements the build procedure for packages using the
6676 @url{https://www.cmake.org, CMake build tool}.
6678 It automatically adds the @code{cmake} package to the set of inputs.
6679 Which package is used can be specified with the @code{#:cmake}
6682 The @code{#:configure-flags} parameter is taken as a list of flags
6683 passed to the @command{cmake} command. The @code{#:build-type}
6684 parameter specifies in abstract terms the flags passed to the compiler;
6685 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
6686 debugging information''), which roughly means that code is compiled with
6687 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
6690 @defvr {Scheme Variable} dune-build-system
6691 This variable is exported by @code{(guix build-system dune)}. It
6692 supports builds of packages using @uref{https://dune.build/, Dune}, a build
6693 tool for the OCaml programming language. It is implemented as an extension
6694 of the @code{ocaml-build-system} which is described below. As such, the
6695 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
6698 It automatically adds the @code{dune} package to the set of inputs.
6699 Which package is used can be specified with the @code{#:dune}
6702 There is no @code{configure} phase because dune packages typically don't
6703 need to be configured. The @code{#:build-flags} parameter is taken as a
6704 list of flags passed to the @code{dune} command during the build.
6706 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
6707 command instead of the more recent @code{dune} command while building
6708 a package. Its default value is @code{#f}.
6710 The @code{#:package} parameter can be passed to specify a package name, which
6711 is useful when a package contains multiple packages and you want to build
6712 only one of them. This is equivalent to passing the @code{-p} argument to
6716 @defvr {Scheme Variable} go-build-system
6717 This variable is exported by @code{(guix build-system go)}. It
6718 implements a build procedure for Go packages using the standard
6719 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
6720 Go build mechanisms}.
6722 The user is expected to provide a value for the key @code{#:import-path}
6723 and, in some cases, @code{#:unpack-path}. The
6724 @url{https://golang.org/doc/code.html#ImportPaths, import path}
6725 corresponds to the file system path expected by the package's build
6726 scripts and any referring packages, and provides a unique way to
6727 refer to a Go package. It is typically based on a combination of the
6728 package source code's remote URI and file system hierarchy structure. In
6729 some cases, you will need to unpack the package's source code to a
6730 different directory structure than the one indicated by the import path,
6731 and @code{#:unpack-path} should be used in such cases.
6733 Packages that provide Go libraries should install their source code into
6734 the built output. The key @code{#:install-source?}, which defaults to
6735 @code{#t}, controls whether or not the source code is installed. It can
6736 be set to @code{#f} for packages that only provide executable files.
6739 @defvr {Scheme Variable} glib-or-gtk-build-system
6740 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
6741 is intended for use with packages making use of GLib or GTK+.
6743 This build system adds the following two phases to the ones defined by
6744 @code{gnu-build-system}:
6747 @item glib-or-gtk-wrap
6748 The phase @code{glib-or-gtk-wrap} ensures that programs in
6749 @file{bin/} are able to find GLib ``schemas'' and
6750 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
6751 modules}. This is achieved by wrapping the programs in launch scripts
6752 that appropriately set the @env{XDG_DATA_DIRS} and @env{GTK_PATH}
6753 environment variables.
6755 It is possible to exclude specific package outputs from that wrapping
6756 process by listing their names in the
6757 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
6758 when an output is known not to contain any GLib or GTK+ binaries, and
6759 where wrapping would gratuitously add a dependency of that output on
6762 @item glib-or-gtk-compile-schemas
6763 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
6764 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
6765 GSettings schemas} of GLib are compiled. Compilation is performed by the
6766 @command{glib-compile-schemas} program. It is provided by the package
6767 @code{glib:bin} which is automatically imported by the build system.
6768 The @code{glib} package providing @command{glib-compile-schemas} can be
6769 specified with the @code{#:glib} parameter.
6772 Both phases are executed after the @code{install} phase.
6775 @defvr {Scheme Variable} guile-build-system
6776 This build system is for Guile packages that consist exclusively of Scheme
6777 code and that are so lean that they don't even have a makefile, let alone a
6778 @file{configure} script. It compiles Scheme code using @command{guild
6779 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
6780 installs the @file{.scm} and @file{.go} files in the right place. It also
6781 installs documentation.
6783 This build system supports cross-compilation by using the
6784 @option{--target} option of @samp{guild compile}.
6786 Packages built with @code{guile-build-system} must provide a Guile package in
6787 their @code{native-inputs} field.
6790 @defvr {Scheme Variable} julia-build-system
6791 This variable is exported by @code{(guix build-system julia)}. It
6792 implements the build procedure used by @uref{https://julialang.org/,
6793 julia} packages, which essentially is similar to running @samp{julia -e
6794 'using Pkg; Pkg.add(package)'} in an environment where
6795 @env{JULIA_LOAD_PATH} contains the paths to all Julia package inputs.
6796 Tests are run not run.
6798 Julia packages require the source @code{file-name} to be the real name of the
6799 package, correctly capitalized.
6801 For packages requiring shared library dependencies, you may need to write the
6802 @file{/deps/deps.jl} file manually. It's usually a line of @code{const
6803 variable = /gnu/store/library.so} for each dependency, plus a void function
6804 @code{check_deps() = nothing}.
6806 Some older packages that aren't using @file{Package.toml} yet, will require
6807 this file to be created, too. The function @code{julia-create-package-toml}
6808 helps creating the file. You need to pass the outputs and the source of the
6809 package, it's name (the same as the @code{file-name} parameter), the package
6810 uuid, the package version, and a list of dependencies specified by their name
6814 @defvr {Scheme Variable} minify-build-system
6815 This variable is exported by @code{(guix build-system minify)}. It
6816 implements a minification procedure for simple JavaScript packages.
6818 It adds @code{uglify-js} to the set of inputs and uses it to compress
6819 all JavaScript files in the @file{src} directory. A different minifier
6820 package can be specified with the @code{#:uglify-js} parameter, but it
6821 is expected that the package writes the minified code to the standard
6824 When the input JavaScript files are not all located in the @file{src}
6825 directory, the parameter @code{#:javascript-files} can be used to
6826 specify a list of file names to feed to the minifier.
6829 @defvr {Scheme Variable} ocaml-build-system
6830 This variable is exported by @code{(guix build-system ocaml)}. It implements
6831 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
6832 of choosing the correct set of commands to run for each package. OCaml
6833 packages can expect many different commands to be run. This build system will
6836 When the package has a @file{setup.ml} file present at the top-level, it will
6837 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
6838 @code{ocaml setup.ml -install}. The build system will assume that this file
6839 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
6840 care of setting the prefix and enabling tests if they are not disabled. You
6841 can pass configure and build flags with the @code{#:configure-flags} and
6842 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
6843 set of flags used to enable tests. The @code{#:use-make?} key can be used to
6844 bypass this system in the build and install phases.
6846 When the package has a @file{configure} file, it is assumed that it is a
6847 hand-made configure script that requires a different argument format than
6848 in the @code{gnu-build-system}. You can add more flags with the
6849 @code{#:configure-flags} key.
6851 When the package has a @file{Makefile} file (or @code{#:use-make?} is
6852 @code{#t}), it will be used and more flags can be passed to the build and
6853 install phases with the @code{#:make-flags} key.
6855 Finally, some packages do not have these files and use a somewhat standard
6856 location for its build system. In that case, the build system will run
6857 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
6858 providing the path to the required findlib module. Additional flags can
6859 be passed via the @code{#:build-flags} key. Install is taken care of by
6860 @command{opam-installer}. In this case, the @code{opam} package must
6861 be added to the @code{native-inputs} field of the package definition.
6863 Note that most OCaml packages assume they will be installed in the same
6864 directory as OCaml, which is not what we want in guix. In particular, they
6865 will install @file{.so} files in their module's directory, which is usually
6866 fine because it is in the OCaml compiler directory. In guix though, these
6867 libraries cannot be found and we use @env{CAML_LD_LIBRARY_PATH}. This
6868 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
6869 @file{.so} libraries should be installed.
6872 @defvr {Scheme Variable} python-build-system
6873 This variable is exported by @code{(guix build-system python)}. It
6874 implements the more or less standard build procedure used by Python
6875 packages, which consists in running @code{python setup.py build} and
6876 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
6878 For packages that install stand-alone Python programs under @code{bin/},
6879 it takes care of wrapping these programs so that their @env{PYTHONPATH}
6880 environment variable points to all the Python libraries they depend on.
6882 Which Python package is used to perform the build can be specified with
6883 the @code{#:python} parameter. This is a useful way to force a package
6884 to be built for a specific version of the Python interpreter, which
6885 might be necessary if the package is only compatible with a single
6886 interpreter version.
6888 By default guix calls @code{setup.py} under control of
6889 @code{setuptools}, much like @command{pip} does. Some packages are not
6890 compatible with setuptools (and pip), thus you can disable this by
6891 setting the @code{#:use-setuptools?} parameter to @code{#f}.
6894 @defvr {Scheme Variable} perl-build-system
6895 This variable is exported by @code{(guix build-system perl)}. It
6896 implements the standard build procedure for Perl packages, which either
6897 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
6898 followed by @code{Build} and @code{Build install}; or in running
6899 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
6900 @code{make} and @code{make install}, depending on which of
6901 @code{Build.PL} or @code{Makefile.PL} is present in the package
6902 distribution. Preference is given to the former if both @code{Build.PL}
6903 and @code{Makefile.PL} exist in the package distribution. This
6904 preference can be reversed by specifying @code{#t} for the
6905 @code{#:make-maker?} parameter.
6907 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
6908 passes flags specified by the @code{#:make-maker-flags} or
6909 @code{#:module-build-flags} parameter, respectively.
6911 Which Perl package is used can be specified with @code{#:perl}.
6914 @defvr {Scheme Variable} qt-build-system
6915 This variable is exported by @code{(guix build-system qt)}. It
6916 is intended for use with applications using Qt or KDE.
6918 This build system adds the following two phases to the ones defined by
6919 @code{cmake-build-system}:
6923 The phase @code{check-setup} prepares the environment for running
6924 the checks as commonly used by Qt test programs.
6925 For now this only sets some environment variables:
6926 @code{QT_QPA_PLATFORM=offscreen},
6927 @code{DBUS_FATAL_WARNINGS=0} and
6928 @code{CTEST_OUTPUT_ON_FAILURE=1}.
6930 This phase is added before the @code{check} phase.
6931 It's a separate phase to ease adjusting if necessary.
6934 The phase @code{qt-wrap}
6935 searches for Qt5 plugin paths, QML paths and some XDG in the inputs
6936 and output. In case some path is found, all programs in the output's
6937 @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
6938 are wrapped in scripts defining the necessary environment variables.
6940 It is possible to exclude specific package outputs from that wrapping process
6941 by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
6942 This is useful when an output is known not to contain any Qt binaries, and
6943 where wrapping would gratuitously add a dependency of that output on Qt, KDE,
6946 This phase is added after the @code{install} phase.
6950 @defvr {Scheme Variable} r-build-system
6951 This variable is exported by @code{(guix build-system r)}. It
6952 implements the build procedure used by @uref{https://r-project.org, R}
6953 packages, which essentially is little more than running @samp{R CMD
6954 INSTALL --library=/gnu/store/@dots{}} in an environment where
6955 @env{R_LIBS_SITE} contains the paths to all R package inputs. Tests are
6956 run after installation using the R function
6957 @code{tools::testInstalledPackage}.
6960 @defvr {Scheme Variable} rakudo-build-system
6961 This variable is exported by @code{(guix build-system rakudo)}. It
6962 implements the build procedure used by @uref{https://rakudo.org/,
6963 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
6964 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
6965 installs the binaries, library files and the resources, as well as wrap
6966 the files under the @code{bin/} directory. Tests can be skipped by
6967 passing @code{#f} to the @code{tests?} parameter.
6969 Which rakudo package is used can be specified with @code{rakudo}.
6970 Which perl6-tap-harness package used for the tests can be specified with
6971 @code{#:prove6} or removed by passing @code{#f} to the
6972 @code{with-prove6?} parameter.
6973 Which perl6-zef package used for tests and installing can be specified
6974 with @code{#:zef} or removed by passing @code{#f} to the
6975 @code{with-zef?} parameter.
6978 @defvr {Scheme Variable} texlive-build-system
6979 This variable is exported by @code{(guix build-system texlive)}. It is
6980 used to build TeX packages in batch mode with a specified engine. The
6981 build system sets the @env{TEXINPUTS} variable to find all TeX source
6982 files in the inputs.
6984 By default it runs @code{luatex} on all files ending on @code{ins}. A
6985 different engine and format can be specified with the
6986 @code{#:tex-format} argument. Different build targets can be specified
6987 with the @code{#:build-targets} argument, which expects a list of file
6988 names. The build system adds only @code{texlive-bin} and
6989 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
6990 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
6991 and @code{#:texlive-latex-base}, respectively.
6993 The @code{#:tex-directory} parameter tells the build system where to
6994 install the built files under the texmf tree.
6997 @defvr {Scheme Variable} ruby-build-system
6998 This variable is exported by @code{(guix build-system ruby)}. It
6999 implements the RubyGems build procedure used by Ruby packages, which
7000 involves running @code{gem build} followed by @code{gem install}.
7002 The @code{source} field of a package that uses this build system
7003 typically references a gem archive, since this is the format that Ruby
7004 developers use when releasing their software. The build system unpacks
7005 the gem archive, potentially patches the source, runs the test suite,
7006 repackages the gem, and installs it. Additionally, directories and
7007 tarballs may be referenced to allow building unreleased gems from Git or
7008 a traditional source release tarball.
7010 Which Ruby package is used can be specified with the @code{#:ruby}
7011 parameter. A list of additional flags to be passed to the @command{gem}
7012 command can be specified with the @code{#:gem-flags} parameter.
7015 @defvr {Scheme Variable} waf-build-system
7016 This variable is exported by @code{(guix build-system waf)}. It
7017 implements a build procedure around the @code{waf} script. The common
7018 phases---@code{configure}, @code{build}, and @code{install}---are
7019 implemented by passing their names as arguments to the @code{waf}
7022 The @code{waf} script is executed by the Python interpreter. Which
7023 Python package is used to run the script can be specified with the
7024 @code{#:python} parameter.
7027 @defvr {Scheme Variable} scons-build-system
7028 This variable is exported by @code{(guix build-system scons)}. It
7029 implements the build procedure used by the SCons software construction
7030 tool. This build system runs @code{scons} to build the package,
7031 @code{scons test} to run tests, and then @code{scons install} to install
7034 Additional flags to be passed to @code{scons} can be specified with the
7035 @code{#:scons-flags} parameter. The default build and install targets
7036 can be overridden with @code{#:build-targets} and
7037 @code{#:install-targets} respectively. The version of Python used to
7038 run SCons can be specified by selecting the appropriate SCons package
7039 with the @code{#:scons} parameter.
7042 @defvr {Scheme Variable} haskell-build-system
7043 This variable is exported by @code{(guix build-system haskell)}. It
7044 implements the Cabal build procedure used by Haskell packages, which
7045 involves running @code{runhaskell Setup.hs configure
7046 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
7047 Instead of installing the package by running @code{runhaskell Setup.hs
7048 install}, to avoid trying to register libraries in the read-only
7049 compiler store directory, the build system uses @code{runhaskell
7050 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
7051 addition, the build system generates the package documentation by
7052 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
7053 is passed. Optional Haddock parameters can be passed with the help of
7054 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
7055 not found, the build system looks for @code{Setup.lhs} instead.
7057 Which Haskell compiler is used can be specified with the @code{#:haskell}
7058 parameter which defaults to @code{ghc}.
7061 @defvr {Scheme Variable} dub-build-system
7062 This variable is exported by @code{(guix build-system dub)}. It
7063 implements the Dub build procedure used by D packages, which
7064 involves running @code{dub build} and @code{dub run}.
7065 Installation is done by copying the files manually.
7067 Which D compiler is used can be specified with the @code{#:ldc}
7068 parameter which defaults to @code{ldc}.
7071 @defvr {Scheme Variable} emacs-build-system
7072 This variable is exported by @code{(guix build-system emacs)}. It
7073 implements an installation procedure similar to the packaging system
7074 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
7076 It first creates the @code{@code{package}-autoloads.el} file, then it
7077 byte compiles all Emacs Lisp files. Differently from the Emacs
7078 packaging system, the Info documentation files are moved to the standard
7079 documentation directory and the @file{dir} file is deleted. The Elisp
7080 package files are installed directly under @file{share/emacs/site-lisp}.
7083 @defvr {Scheme Variable} font-build-system
7084 This variable is exported by @code{(guix build-system font)}. It
7085 implements an installation procedure for font packages where upstream
7086 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
7087 need to be copied into place. It copies font files to standard
7088 locations in the output directory.
7091 @defvr {Scheme Variable} meson-build-system
7092 This variable is exported by @code{(guix build-system meson)}. It
7093 implements the build procedure for packages that use
7094 @url{https://mesonbuild.com, Meson} as their build system.
7096 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
7097 of inputs, and they can be changed with the parameters @code{#:meson}
7098 and @code{#:ninja} if needed. The default Meson is
7099 @code{meson-for-build}, which is special because it doesn't clear the
7100 @code{RUNPATH} of binaries and libraries when they are installed.
7102 This build system is an extension of @code{gnu-build-system}, but with the
7103 following phases changed to some specific for Meson:
7108 The phase runs @code{meson} with the flags specified in
7109 @code{#:configure-flags}. The flag @option{--buildtype} is always set to
7110 @code{debugoptimized} unless something else is specified in
7111 @code{#:build-type}.
7114 The phase runs @code{ninja} to build the package in parallel by default, but
7115 this can be changed with @code{#:parallel-build?}.
7118 The phase runs @code{ninja} with the target specified in @code{#:test-target},
7119 which is @code{"test"} by default.
7122 The phase runs @code{ninja install} and can not be changed.
7125 Apart from that, the build system also adds the following phases:
7130 This phase ensures that all binaries can find the libraries they need.
7131 It searches for required libraries in subdirectories of the package being
7132 built, and adds those to @code{RUNPATH} where needed. It also removes
7133 references to libraries left over from the build phase by
7134 @code{meson-for-build}, such as test dependencies, that aren't actually
7135 required for the program to run.
7137 @item glib-or-gtk-wrap
7138 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
7139 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
7141 @item glib-or-gtk-compile-schemas
7142 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
7143 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
7147 @defvr {Scheme Variable} linux-module-build-system
7148 @code{linux-module-build-system} allows building Linux kernel modules.
7150 @cindex build phases
7151 This build system is an extension of @code{gnu-build-system}, but with the
7152 following phases changed:
7157 This phase configures the environment so that the Linux kernel's Makefile
7158 can be used to build the external kernel module.
7161 This phase uses the Linux kernel's Makefile in order to build the external
7165 This phase uses the Linux kernel's Makefile in order to install the external
7169 It is possible and useful to specify the Linux kernel to use for building
7170 the module (in the @code{arguments} form of a package using the
7171 @code{linux-module-build-system}, use the key @code{#:linux} to specify it).
7174 @defvr {Scheme Variable} node-build-system
7175 This variable is exported by @code{(guix build-system node)}. It
7176 implements the build procedure used by @uref{https://nodejs.org,
7177 Node.js}, which implements an approximation of the @code{npm install}
7178 command, followed by an @code{npm test} command.
7180 Which Node.js package is used to interpret the @code{npm} commands can
7181 be specified with the @code{#:node} parameter which defaults to
7185 Lastly, for packages that do not need anything as sophisticated, a
7186 ``trivial'' build system is provided. It is trivial in the sense that
7187 it provides basically no support: it does not pull any implicit inputs,
7188 and does not have a notion of build phases.
7190 @defvr {Scheme Variable} trivial-build-system
7191 This variable is exported by @code{(guix build-system trivial)}.
7193 This build system requires a @code{#:builder} argument. This argument
7194 must be a Scheme expression that builds the package output(s)---as
7195 with @code{build-expression->derivation} (@pxref{Derivations,
7196 @code{build-expression->derivation}}).
7206 Conceptually, the @dfn{store} is the place where derivations that have
7207 been built successfully are stored---by default, @file{/gnu/store}.
7208 Sub-directories in the store are referred to as @dfn{store items} or
7209 sometimes @dfn{store paths}. The store has an associated database that
7210 contains information such as the store paths referred to by each store
7211 path, and the list of @emph{valid} store items---results of successful
7212 builds. This database resides in @file{@var{localstatedir}/guix/db},
7213 where @var{localstatedir} is the state directory specified @i{via}
7214 @option{--localstatedir} at configure time, usually @file{/var}.
7216 The store is @emph{always} accessed by the daemon on behalf of its clients
7217 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
7218 connect to the daemon over a Unix-domain socket, send requests to it,
7219 and read the result---these are remote procedure calls, or RPCs.
7222 Users must @emph{never} modify files under @file{/gnu/store} directly.
7223 This would lead to inconsistencies and break the immutability
7224 assumptions of Guix's functional model (@pxref{Introduction}).
7226 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
7227 how to check the integrity of the store and attempt recovery from
7228 accidental modifications.
7231 The @code{(guix store)} module provides procedures to connect to the
7232 daemon, and to perform RPCs. These are described below. By default,
7233 @code{open-connection}, and thus all the @command{guix} commands,
7234 connect to the local daemon or to the URI specified by the
7235 @env{GUIX_DAEMON_SOCKET} environment variable.
7237 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
7238 When set, the value of this variable should be a file name or a URI
7239 designating the daemon endpoint. When it is a file name, it denotes a
7240 Unix-domain socket to connect to. In addition to file names, the
7241 supported URI schemes are:
7246 These are for Unix-domain sockets.
7247 @code{file:///var/guix/daemon-socket/socket} is equivalent to
7248 @file{/var/guix/daemon-socket/socket}.
7251 @cindex daemon, remote access
7252 @cindex remote access to the daemon
7253 @cindex daemon, cluster setup
7254 @cindex clusters, daemon setup
7255 These URIs denote connections over TCP/IP, without encryption nor
7256 authentication of the remote host. The URI must specify the host name
7257 and optionally a port number (by default port 44146 is used):
7260 guix://master.guix.example.org:1234
7263 This setup is suitable on local networks, such as clusters, where only
7264 trusted nodes may connect to the build daemon at
7265 @code{master.guix.example.org}.
7267 The @option{--listen} option of @command{guix-daemon} can be used to
7268 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
7269 @option{--listen}}).
7272 @cindex SSH access to build daemons
7273 These URIs allow you to connect to a remote daemon over SSH. This
7274 feature requires Guile-SSH (@pxref{Requirements}) and a working
7275 @command{guile} binary in @env{PATH} on the destination machine. It
7276 supports public key and GSSAPI authentication. A typical URL might look
7280 ssh://charlie@@guix.example.org:22
7283 As for @command{guix copy}, the usual OpenSSH client configuration files
7284 are honored (@pxref{Invoking guix copy}).
7287 Additional URI schemes may be supported in the future.
7289 @c XXX: Remove this note when the protocol incurs fewer round trips
7290 @c and when (guix derivations) no longer relies on file system access.
7292 The ability to connect to remote build daemons is considered
7293 experimental as of @value{VERSION}. Please get in touch with us to
7294 share any problems or suggestions you may have (@pxref{Contributing}).
7298 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
7299 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
7300 @var{reserve-space?} is true, instruct it to reserve a little bit of
7301 extra space on the file system so that the garbage collector can still
7302 operate should the disk become full. Return a server object.
7304 @var{file} defaults to @code{%default-socket-path}, which is the normal
7305 location given the options that were passed to @command{configure}.
7308 @deffn {Scheme Procedure} close-connection @var{server}
7309 Close the connection to @var{server}.
7312 @defvr {Scheme Variable} current-build-output-port
7313 This variable is bound to a SRFI-39 parameter, which refers to the port
7314 where build and error logs sent by the daemon should be written.
7317 Procedures that make RPCs all take a server object as their first
7320 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
7321 @cindex invalid store items
7322 Return @code{#t} when @var{path} designates a valid store item and
7323 @code{#f} otherwise (an invalid item may exist on disk but still be
7324 invalid, for instance because it is the result of an aborted or failed
7327 A @code{&store-protocol-error} condition is raised if @var{path} is not
7328 prefixed by the store directory (@file{/gnu/store}).
7331 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
7332 Add @var{text} under file @var{name} in the store, and return its store
7333 path. @var{references} is the list of store paths referred to by the
7334 resulting store path.
7337 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
7339 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
7340 file names, or derivation/output pairs, using the specified
7341 @var{mode}---@code{(build-mode normal)} by default.
7344 Note that the @code{(guix monads)} module provides a monad as well as
7345 monadic versions of the above procedures, with the goal of making it
7346 more convenient to work with code that accesses the store (@pxref{The
7350 @i{This section is currently incomplete.}
7353 @section Derivations
7356 Low-level build actions and the environment in which they are performed
7357 are represented by @dfn{derivations}. A derivation contains the
7358 following pieces of information:
7362 The outputs of the derivation---derivations produce at least one file or
7363 directory in the store, but may produce more.
7366 @cindex build-time dependencies
7367 @cindex dependencies, build-time
7368 The inputs of the derivations---i.e., its build-time dependencies---which may
7369 be other derivations or plain files in the store (patches, build scripts,
7373 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
7376 The file name of a build script in the store, along with the arguments
7380 A list of environment variables to be defined.
7384 @cindex derivation path
7385 Derivations allow clients of the daemon to communicate build actions to
7386 the store. They exist in two forms: as an in-memory representation,
7387 both on the client- and daemon-side, and as files in the store whose
7388 name end in @file{.drv}---these files are referred to as @dfn{derivation
7389 paths}. Derivations paths can be passed to the @code{build-derivations}
7390 procedure to perform the build actions they prescribe (@pxref{The
7393 @cindex fixed-output derivations
7394 Operations such as file downloads and version-control checkouts for
7395 which the expected content hash is known in advance are modeled as
7396 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
7397 of a fixed-output derivation are independent of its inputs---e.g., a
7398 source code download produces the same result regardless of the download
7399 method and tools being used.
7402 @cindex run-time dependencies
7403 @cindex dependencies, run-time
7404 The outputs of derivations---i.e., the build results---have a set of
7405 @dfn{references}, as reported by the @code{references} RPC or the
7406 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
7407 are the set of run-time dependencies of the build results. References are a
7408 subset of the inputs of the derivation; this subset is automatically computed
7409 by the build daemon by scanning all the files in the outputs.
7411 The @code{(guix derivations)} module provides a representation of
7412 derivations as Scheme objects, along with procedures to create and
7413 otherwise manipulate derivations. The lowest-level primitive to create
7414 a derivation is the @code{derivation} procedure:
7416 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
7417 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
7418 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
7419 [#:system (%current-system)] [#:references-graphs #f] @
7420 [#:allowed-references #f] [#:disallowed-references #f] @
7421 [#:leaked-env-vars #f] [#:local-build? #f] @
7422 [#:substitutable? #t] [#:properties '()]
7423 Build a derivation with the given arguments, and return the resulting
7424 @code{<derivation>} object.
7426 When @var{hash} and @var{hash-algo} are given, a
7427 @dfn{fixed-output derivation} is created---i.e., one whose result is
7428 known in advance, such as a file download. If, in addition,
7429 @var{recursive?} is true, then that fixed output may be an executable
7430 file or a directory and @var{hash} must be the hash of an archive
7431 containing this output.
7433 When @var{references-graphs} is true, it must be a list of file
7434 name/store path pairs. In that case, the reference graph of each store
7435 path is exported in the build environment in the corresponding file, in
7436 a simple text format.
7438 When @var{allowed-references} is true, it must be a list of store items
7439 or outputs that the derivation's output may refer to. Likewise,
7440 @var{disallowed-references}, if true, must be a list of things the
7441 outputs may @emph{not} refer to.
7443 When @var{leaked-env-vars} is true, it must be a list of strings
7444 denoting environment variables that are allowed to ``leak'' from the
7445 daemon's environment to the build environment. This is only applicable
7446 to fixed-output derivations---i.e., when @var{hash} is true. The main
7447 use is to allow variables such as @code{http_proxy} to be passed to
7448 derivations that download files.
7450 When @var{local-build?} is true, declare that the derivation is not a
7451 good candidate for offloading and should rather be built locally
7452 (@pxref{Daemon Offload Setup}). This is the case for small derivations
7453 where the costs of data transfers would outweigh the benefits.
7455 When @var{substitutable?} is false, declare that substitutes of the
7456 derivation's output should not be used (@pxref{Substitutes}). This is
7457 useful, for instance, when building packages that capture details of the
7458 host CPU instruction set.
7460 @var{properties} must be an association list describing ``properties'' of the
7461 derivation. It is kept as-is, uninterpreted, in the derivation.
7465 Here's an example with a shell script as its builder, assuming
7466 @var{store} is an open connection to the daemon, and @var{bash} points
7467 to a Bash executable in the store:
7470 (use-modules (guix utils)
7474 (let ((builder ; add the Bash script to the store
7475 (add-text-to-store store "my-builder.sh"
7476 "echo hello world > $out\n" '())))
7477 (derivation store "foo"
7478 bash `("-e" ,builder)
7479 #:inputs `((,bash) (,builder))
7480 #:env-vars '(("HOME" . "/homeless"))))
7481 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
7484 As can be guessed, this primitive is cumbersome to use directly. A
7485 better approach is to write build scripts in Scheme, of course! The
7486 best course of action for that is to write the build code as a
7487 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
7488 information, @pxref{G-Expressions}.
7490 Once upon a time, @code{gexp->derivation} did not exist and constructing
7491 derivations with build code written in Scheme was achieved with
7492 @code{build-expression->derivation}, documented below. This procedure
7493 is now deprecated in favor of the much nicer @code{gexp->derivation}.
7495 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
7496 @var{name} @var{exp} @
7497 [#:system (%current-system)] [#:inputs '()] @
7498 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
7499 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7500 [#:references-graphs #f] [#:allowed-references #f] @
7501 [#:disallowed-references #f] @
7502 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
7503 Return a derivation that executes Scheme expression @var{exp} as a
7504 builder for derivation @var{name}. @var{inputs} must be a list of
7505 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
7506 @code{"out"} is assumed. @var{modules} is a list of names of Guile
7507 modules from the current search path to be copied in the store,
7508 compiled, and made available in the load path during the execution of
7509 @var{exp}---e.g., @code{((guix build utils) (guix build
7510 gnu-build-system))}.
7512 @var{exp} is evaluated in an environment where @code{%outputs} is bound
7513 to a list of output/path pairs, and where @code{%build-inputs} is bound
7514 to a list of string/output-path pairs made from @var{inputs}.
7515 Optionally, @var{env-vars} is a list of string pairs specifying the name
7516 and value of environment variables visible to the builder. The builder
7517 terminates by passing the result of @var{exp} to @code{exit}; thus, when
7518 @var{exp} returns @code{#f}, the build is considered to have failed.
7520 @var{exp} is built using @var{guile-for-build} (a derivation). When
7521 @var{guile-for-build} is omitted or is @code{#f}, the value of the
7522 @code{%guile-for-build} fluid is used instead.
7524 See the @code{derivation} procedure for the meaning of
7525 @var{references-graphs}, @var{allowed-references},
7526 @var{disallowed-references}, @var{local-build?}, and
7527 @var{substitutable?}.
7531 Here's an example of a single-output derivation that creates a directory
7532 containing one file:
7535 (let ((builder '(let ((out (assoc-ref %outputs "out")))
7536 (mkdir out) ; create /gnu/store/@dots{}-goo
7537 (call-with-output-file (string-append out "/test")
7539 (display '(hello guix) p))))))
7540 (build-expression->derivation store "goo" builder))
7542 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
7546 @node The Store Monad
7547 @section The Store Monad
7551 The procedures that operate on the store described in the previous
7552 sections all take an open connection to the build daemon as their first
7553 argument. Although the underlying model is functional, they either have
7554 side effects or depend on the current state of the store.
7556 The former is inconvenient: the connection to the build daemon has to be
7557 carried around in all those functions, making it impossible to compose
7558 functions that do not take that parameter with functions that do. The
7559 latter can be problematic: since store operations have side effects
7560 and/or depend on external state, they have to be properly sequenced.
7562 @cindex monadic values
7563 @cindex monadic functions
7564 This is where the @code{(guix monads)} module comes in. This module
7565 provides a framework for working with @dfn{monads}, and a particularly
7566 useful monad for our uses, the @dfn{store monad}. Monads are a
7567 construct that allows two things: associating ``context'' with values
7568 (in our case, the context is the store), and building sequences of
7569 computations (here computations include accesses to the store). Values
7570 in a monad---values that carry this additional context---are called
7571 @dfn{monadic values}; procedures that return such values are called
7572 @dfn{monadic procedures}.
7574 Consider this ``normal'' procedure:
7577 (define (sh-symlink store)
7578 ;; Return a derivation that symlinks the 'bash' executable.
7579 (let* ((drv (package-derivation store bash))
7580 (out (derivation->output-path drv))
7581 (sh (string-append out "/bin/bash")))
7582 (build-expression->derivation store "sh"
7583 `(symlink ,sh %output))))
7586 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
7587 as a monadic function:
7590 (define (sh-symlink)
7591 ;; Same, but return a monadic value.
7592 (mlet %store-monad ((drv (package->derivation bash)))
7593 (gexp->derivation "sh"
7594 #~(symlink (string-append #$drv "/bin/bash")
7598 There are several things to note in the second version: the @code{store}
7599 parameter is now implicit and is ``threaded'' in the calls to the
7600 @code{package->derivation} and @code{gexp->derivation} monadic
7601 procedures, and the monadic value returned by @code{package->derivation}
7602 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
7604 As it turns out, the call to @code{package->derivation} can even be
7605 omitted since it will take place implicitly, as we will see later
7606 (@pxref{G-Expressions}):
7609 (define (sh-symlink)
7610 (gexp->derivation "sh"
7611 #~(symlink (string-append #$bash "/bin/bash")
7616 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
7617 @c for the funny quote.
7618 Calling the monadic @code{sh-symlink} has no effect. As someone once
7619 said, ``you exit a monad like you exit a building on fire: by running''.
7620 So, to exit the monad and get the desired effect, one must use
7621 @code{run-with-store}:
7624 (run-with-store (open-connection) (sh-symlink))
7625 @result{} /gnu/store/...-sh-symlink
7628 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
7629 new ``meta-commands'' to make it easier to deal with monadic procedures:
7630 @code{run-in-store}, and @code{enter-store-monad}. The former is used
7631 to ``run'' a single monadic value through the store:
7634 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
7635 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7638 The latter enters a recursive REPL, where all the return values are
7639 automatically run through the store:
7642 scheme@@(guile-user)> ,enter-store-monad
7643 store-monad@@(guile-user) [1]> (package->derivation hello)
7644 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7645 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
7646 $3 = "/gnu/store/@dots{}-foo"
7647 store-monad@@(guile-user) [1]> ,q
7648 scheme@@(guile-user)>
7652 Note that non-monadic values cannot be returned in the
7653 @code{store-monad} REPL.
7655 The main syntactic forms to deal with monads in general are provided by
7656 the @code{(guix monads)} module and are described below.
7658 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
7659 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
7663 @deffn {Scheme Syntax} return @var{val}
7664 Return a monadic value that encapsulates @var{val}.
7667 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
7668 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
7669 procedures @var{mproc}@dots{}@footnote{This operation is commonly
7670 referred to as ``bind'', but that name denotes an unrelated procedure in
7671 Guile. Thus we use this somewhat cryptic symbol inherited from the
7672 Haskell language.}. There can be one @var{mproc} or several of them, as
7677 (with-monad %state-monad
7679 (lambda (x) (return (+ 1 x)))
7680 (lambda (x) (return (* 2 x)))))
7684 @result{} some-state
7688 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
7690 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
7692 Bind the variables @var{var} to the monadic values @var{mval} in
7693 @var{body}, which is a sequence of expressions. As with the bind
7694 operator, this can be thought of as ``unpacking'' the raw, non-monadic
7695 value ``contained'' in @var{mval} and making @var{var} refer to that
7696 raw, non-monadic value within the scope of the @var{body}. The form
7697 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
7698 @var{val}, as per @code{let}. The binding operations occur in sequence
7699 from left to right. The last expression of @var{body} must be a monadic
7700 expression, and its result will become the result of the @code{mlet} or
7701 @code{mlet*} when run in the @var{monad}.
7703 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
7704 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
7707 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
7708 Bind @var{mexp} and the following monadic expressions in sequence,
7709 returning the result of the last expression. Every expression in the
7710 sequence must be a monadic expression.
7712 This is akin to @code{mlet}, except that the return values of the
7713 monadic expressions are ignored. In that sense, it is analogous to
7714 @code{begin}, but applied to monadic expressions.
7717 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
7718 When @var{condition} is true, evaluate the sequence of monadic
7719 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
7720 @var{condition} is false, return @code{*unspecified*} in the current
7721 monad. Every expression in the sequence must be a monadic expression.
7724 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
7725 When @var{condition} is false, evaluate the sequence of monadic
7726 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
7727 @var{condition} is true, return @code{*unspecified*} in the current
7728 monad. Every expression in the sequence must be a monadic expression.
7732 The @code{(guix monads)} module provides the @dfn{state monad}, which
7733 allows an additional value---the state---to be @emph{threaded} through
7734 monadic procedure calls.
7736 @defvr {Scheme Variable} %state-monad
7737 The state monad. Procedures in the state monad can access and change
7738 the state that is threaded.
7740 Consider the example below. The @code{square} procedure returns a value
7741 in the state monad. It returns the square of its argument, but also
7742 increments the current state value:
7746 (mlet %state-monad ((count (current-state)))
7747 (mbegin %state-monad
7748 (set-current-state (+ 1 count))
7751 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
7756 When ``run'' through @code{%state-monad}, we obtain that additional state
7757 value, which is the number of @code{square} calls.
7760 @deffn {Monadic Procedure} current-state
7761 Return the current state as a monadic value.
7764 @deffn {Monadic Procedure} set-current-state @var{value}
7765 Set the current state to @var{value} and return the previous state as a
7769 @deffn {Monadic Procedure} state-push @var{value}
7770 Push @var{value} to the current state, which is assumed to be a list,
7771 and return the previous state as a monadic value.
7774 @deffn {Monadic Procedure} state-pop
7775 Pop a value from the current state and return it as a monadic value.
7776 The state is assumed to be a list.
7779 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
7780 Run monadic value @var{mval} starting with @var{state} as the initial
7781 state. Return two values: the resulting value, and the resulting state.
7784 The main interface to the store monad, provided by the @code{(guix
7785 store)} module, is as follows.
7787 @defvr {Scheme Variable} %store-monad
7788 The store monad---an alias for @code{%state-monad}.
7790 Values in the store monad encapsulate accesses to the store. When its
7791 effect is needed, a value of the store monad must be ``evaluated'' by
7792 passing it to the @code{run-with-store} procedure (see below).
7795 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
7796 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
7797 open store connection.
7800 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
7801 Return as a monadic value the absolute file name in the store of the file
7802 containing @var{text}, a string. @var{references} is a list of store items that the
7803 resulting text file refers to; it defaults to the empty list.
7806 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
7807 Return as a monadic value the absolute file name in the store of the file
7808 containing @var{data}, a bytevector. @var{references} is a list of store
7809 items that the resulting binary file refers to; it defaults to the empty list.
7812 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
7813 [#:recursive? #t] [#:select? (const #t)]
7814 Return the name of @var{file} once interned in the store. Use
7815 @var{name} as its store name, or the basename of @var{file} if
7816 @var{name} is omitted.
7818 When @var{recursive?} is true, the contents of @var{file} are added
7819 recursively; if @var{file} designates a flat file and @var{recursive?}
7820 is true, its contents are added, and its permission bits are kept.
7822 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7823 @var{stat})} for each directory entry, where @var{file} is the entry's
7824 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7825 entries for which @var{select?} does not return true.
7827 The example below adds a file to the store, under two different names:
7830 (run-with-store (open-connection)
7831 (mlet %store-monad ((a (interned-file "README"))
7832 (b (interned-file "README" "LEGU-MIN")))
7833 (return (list a b))))
7835 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
7840 The @code{(guix packages)} module exports the following package-related
7843 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
7844 [#:system (%current-system)] [#:target #f] @
7847 value in the absolute file name of @var{file} within the @var{output}
7848 directory of @var{package}. When @var{file} is omitted, return the name
7849 of the @var{output} directory of @var{package}. When @var{target} is
7850 true, use it as a cross-compilation target triplet.
7852 Note that this procedure does @emph{not} build @var{package}. Thus, the
7853 result might or might not designate an existing file. We recommend not
7854 using this procedure unless you know what you are doing.
7857 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
7858 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
7859 @var{target} [@var{system}]
7860 Monadic version of @code{package-derivation} and
7861 @code{package-cross-derivation} (@pxref{Defining Packages}).
7866 @section G-Expressions
7868 @cindex G-expression
7869 @cindex build code quoting
7870 So we have ``derivations'', which represent a sequence of build actions
7871 to be performed to produce an item in the store (@pxref{Derivations}).
7872 These build actions are performed when asking the daemon to actually
7873 build the derivations; they are run by the daemon in a container
7874 (@pxref{Invoking guix-daemon}).
7876 @cindex strata of code
7877 It should come as no surprise that we like to write these build actions
7878 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
7879 code@footnote{The term @dfn{stratum} in this context was coined by
7880 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
7881 Kiselyov, who has written insightful
7882 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
7883 on this topic}, refers to this kind of code generation as
7884 @dfn{staging}.}: the ``host code''---code that defines packages, talks
7885 to the daemon, etc.---and the ``build code''---code that actually
7886 performs build actions, such as making directories, invoking
7887 @command{make}, etc.
7889 To describe a derivation and its build actions, one typically needs to
7890 embed build code inside host code. It boils down to manipulating build
7891 code as data, and the homoiconicity of Scheme---code has a direct
7892 representation as data---comes in handy for that. But we need more than
7893 the normal @code{quasiquote} mechanism in Scheme to construct build
7896 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
7897 S-expressions adapted to build expressions. G-expressions, or
7898 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
7899 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
7900 @code{#$}, and @code{#$@@}), which are comparable to
7901 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
7902 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
7903 GNU Guile Reference Manual}). However, there are major differences:
7907 Gexps are meant to be written to a file and run or manipulated by other
7911 When a high-level object such as a package or derivation is unquoted
7912 inside a gexp, the result is as if its output file name had been
7916 Gexps carry information about the packages or derivations they refer to,
7917 and these dependencies are automatically added as inputs to the build
7918 processes that use them.
7921 @cindex lowering, of high-level objects in gexps
7922 This mechanism is not limited to package and derivation
7923 objects: @dfn{compilers} able to ``lower'' other high-level objects to
7924 derivations or files in the store can be defined,
7925 such that these objects can also be inserted
7926 into gexps. For example, a useful type of high-level objects that can be
7927 inserted in a gexp is ``file-like objects'', which make it easy to
7928 add files to the store and to refer to them in
7929 derivations and such (see @code{local-file} and @code{plain-file}
7932 To illustrate the idea, here is an example of a gexp:
7939 (symlink (string-append #$coreutils "/bin/ls")
7943 This gexp can be passed to @code{gexp->derivation}; we obtain a
7944 derivation that builds a directory containing exactly one symlink to
7945 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
7948 (gexp->derivation "the-thing" build-exp)
7951 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
7952 substituted to the reference to the @var{coreutils} package in the
7953 actual build code, and @var{coreutils} is automatically made an input to
7954 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
7955 output)}) is replaced by a string containing the directory name of the
7956 output of the derivation.
7958 @cindex cross compilation
7959 In a cross-compilation context, it is useful to distinguish between
7960 references to the @emph{native} build of a package---that can run on the
7961 host---versus references to cross builds of a package. To that end, the
7962 @code{#+} plays the same role as @code{#$}, but is a reference to a
7963 native package build:
7966 (gexp->derivation "vi"
7969 (mkdir (string-append #$output "/bin"))
7970 (system* (string-append #+coreutils "/bin/ln")
7972 (string-append #$emacs "/bin/emacs")
7973 (string-append #$output "/bin/vi")))
7974 #:target "aarch64-linux-gnu")
7978 In the example above, the native build of @var{coreutils} is used, so
7979 that @command{ln} can actually run on the host; but then the
7980 cross-compiled build of @var{emacs} is referenced.
7982 @cindex imported modules, for gexps
7983 @findex with-imported-modules
7984 Another gexp feature is @dfn{imported modules}: sometimes you want to be
7985 able to use certain Guile modules from the ``host environment'' in the
7986 gexp, so those modules should be imported in the ``build environment''.
7987 The @code{with-imported-modules} form allows you to express that:
7990 (let ((build (with-imported-modules '((guix build utils))
7992 (use-modules (guix build utils))
7993 (mkdir-p (string-append #$output "/bin"))))))
7994 (gexp->derivation "empty-dir"
7997 (display "success!\n")
8002 In this example, the @code{(guix build utils)} module is automatically
8003 pulled into the isolated build environment of our gexp, such that
8004 @code{(use-modules (guix build utils))} works as expected.
8006 @cindex module closure
8007 @findex source-module-closure
8008 Usually you want the @emph{closure} of the module to be imported---i.e.,
8009 the module itself and all the modules it depends on---rather than just
8010 the module; failing to do that, attempts to use the module will fail
8011 because of missing dependent modules. The @code{source-module-closure}
8012 procedure computes the closure of a module by looking at its source file
8013 headers, which comes in handy in this case:
8016 (use-modules (guix modules)) ;for 'source-module-closure'
8018 (with-imported-modules (source-module-closure
8019 '((guix build utils)
8021 (gexp->derivation "something-with-vms"
8023 (use-modules (guix build utils)
8028 @cindex extensions, for gexps
8029 @findex with-extensions
8030 In the same vein, sometimes you want to import not just pure-Scheme
8031 modules, but also ``extensions'' such as Guile bindings to C libraries
8032 or other ``full-blown'' packages. Say you need the @code{guile-json}
8033 package available on the build side, here's how you would do it:
8036 (use-modules (gnu packages guile)) ;for 'guile-json'
8038 (with-extensions (list guile-json)
8039 (gexp->derivation "something-with-json"
8041 (use-modules (json))
8045 The syntactic form to construct gexps is summarized below.
8047 @deffn {Scheme Syntax} #~@var{exp}
8048 @deffnx {Scheme Syntax} (gexp @var{exp})
8049 Return a G-expression containing @var{exp}. @var{exp} may contain one
8050 or more of the following forms:
8054 @itemx (ungexp @var{obj})
8055 Introduce a reference to @var{obj}. @var{obj} may have one of the
8056 supported types, for example a package or a
8057 derivation, in which case the @code{ungexp} form is replaced by its
8058 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
8060 If @var{obj} is a list, it is traversed and references to supported
8061 objects are substituted similarly.
8063 If @var{obj} is another gexp, its contents are inserted and its
8064 dependencies are added to those of the containing gexp.
8066 If @var{obj} is another kind of object, it is inserted as is.
8068 @item #$@var{obj}:@var{output}
8069 @itemx (ungexp @var{obj} @var{output})
8070 This is like the form above, but referring explicitly to the
8071 @var{output} of @var{obj}---this is useful when @var{obj} produces
8072 multiple outputs (@pxref{Packages with Multiple Outputs}).
8075 @itemx #+@var{obj}:output
8076 @itemx (ungexp-native @var{obj})
8077 @itemx (ungexp-native @var{obj} @var{output})
8078 Same as @code{ungexp}, but produces a reference to the @emph{native}
8079 build of @var{obj} when used in a cross compilation context.
8081 @item #$output[:@var{output}]
8082 @itemx (ungexp output [@var{output}])
8083 Insert a reference to derivation output @var{output}, or to the main
8084 output when @var{output} is omitted.
8086 This only makes sense for gexps passed to @code{gexp->derivation}.
8089 @itemx (ungexp-splicing @var{lst})
8090 Like the above, but splices the contents of @var{lst} inside the
8094 @itemx (ungexp-native-splicing @var{lst})
8095 Like the above, but refers to native builds of the objects listed in
8100 G-expressions created by @code{gexp} or @code{#~} are run-time objects
8101 of the @code{gexp?} type (see below).
8104 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
8105 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
8106 in their execution environment.
8108 Each item in @var{modules} can be the name of a module, such as
8109 @code{(guix build utils)}, or it can be a module name, followed by an
8110 arrow, followed by a file-like object:
8113 `((guix build utils)
8115 ((guix config) => ,(scheme-file "config.scm"
8116 #~(define-module @dots{}))))
8120 In the example above, the first two modules are taken from the search
8121 path, and the last one is created from the given file-like object.
8123 This form has @emph{lexical} scope: it has an effect on the gexps
8124 directly defined in @var{body}@dots{}, but not on those defined, say, in
8125 procedures called from @var{body}@dots{}.
8128 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
8129 Mark the gexps defined in @var{body}@dots{} as requiring
8130 @var{extensions} in their build and execution environment.
8131 @var{extensions} is typically a list of package objects such as those
8132 defined in the @code{(gnu packages guile)} module.
8134 Concretely, the packages listed in @var{extensions} are added to the
8135 load path while compiling imported modules in @var{body}@dots{}; they
8136 are also added to the load path of the gexp returned by
8140 @deffn {Scheme Procedure} gexp? @var{obj}
8141 Return @code{#t} if @var{obj} is a G-expression.
8144 G-expressions are meant to be written to disk, either as code building
8145 some derivation, or as plain files in the store. The monadic procedures
8146 below allow you to do that (@pxref{The Store Monad}, for more
8147 information about monads).
8149 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
8150 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
8151 [#:hash #f] [#:hash-algo #f] @
8152 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
8153 [#:module-path @code{%load-path}] @
8154 [#:effective-version "2.2"] @
8155 [#:references-graphs #f] [#:allowed-references #f] @
8156 [#:disallowed-references #f] @
8157 [#:leaked-env-vars #f] @
8158 [#:script-name (string-append @var{name} "-builder")] @
8159 [#:deprecation-warnings #f] @
8160 [#:local-build? #f] [#:substitutable? #t] @
8161 [#:properties '()] [#:guile-for-build #f]
8162 Return a derivation @var{name} that runs @var{exp} (a gexp) with
8163 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
8164 stored in a file called @var{script-name}. When @var{target} is true,
8165 it is used as the cross-compilation target triplet for packages referred
8168 @var{modules} is deprecated in favor of @code{with-imported-modules}.
8170 make @var{modules} available in the evaluation context of @var{exp};
8171 @var{modules} is a list of names of Guile modules searched in
8172 @var{module-path} to be copied in the store, compiled, and made available in
8173 the load path during the execution of @var{exp}---e.g., @code{((guix
8174 build utils) (guix build gnu-build-system))}.
8176 @var{effective-version} determines the string to use when adding extensions of
8177 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
8179 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
8182 When @var{references-graphs} is true, it must be a list of tuples of one of the
8186 (@var{file-name} @var{package})
8187 (@var{file-name} @var{package} @var{output})
8188 (@var{file-name} @var{derivation})
8189 (@var{file-name} @var{derivation} @var{output})
8190 (@var{file-name} @var{store-item})
8193 The right-hand-side of each element of @var{references-graphs} is automatically made
8194 an input of the build process of @var{exp}. In the build environment, each
8195 @var{file-name} contains the reference graph of the corresponding item, in a simple
8198 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
8199 In the latter case, the list denotes store items that the result is allowed to
8200 refer to. Any reference to another store item will lead to a build error.
8201 Similarly for @var{disallowed-references}, which can list items that must not be
8202 referenced by the outputs.
8204 @var{deprecation-warnings} determines whether to show deprecation warnings while
8205 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
8207 The other arguments are as for @code{derivation} (@pxref{Derivations}).
8210 @cindex file-like objects
8211 The @code{local-file}, @code{plain-file}, @code{computed-file},
8212 @code{program-file}, and @code{scheme-file} procedures below return
8213 @dfn{file-like objects}. That is, when unquoted in a G-expression,
8214 these objects lead to a file in the store. Consider this G-expression:
8217 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
8218 #$(local-file "/tmp/my-nscd.conf"))
8221 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
8222 to the store. Once expanded, for instance @i{via}
8223 @code{gexp->derivation}, the G-expression refers to that copy under
8224 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
8225 does not have any effect on what the G-expression does.
8226 @code{plain-file} can be used similarly; it differs in that the file
8227 content is directly passed as a string.
8229 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
8230 [#:recursive? #f] [#:select? (const #t)]
8231 Return an object representing local file @var{file} to add to the store;
8232 this object can be used in a gexp. If @var{file} is a literal string
8233 denoting a relative file name, it is looked up relative to the source
8234 file where it appears; if @var{file} is not a literal string, it is
8235 looked up relative to the current working directory at run time.
8236 @var{file} will be added to the store under @var{name}--by default the
8237 base name of @var{file}.
8239 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
8240 designates a flat file and @var{recursive?} is true, its contents are added, and its
8241 permission bits are kept.
8243 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
8244 @var{stat})} for each directory entry, where @var{file} is the entry's
8245 absolute file name and @var{stat} is the result of @code{lstat}; exclude
8246 entries for which @var{select?} does not return true.
8248 This is the declarative counterpart of the @code{interned-file} monadic
8249 procedure (@pxref{The Store Monad, @code{interned-file}}).
8252 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
8253 Return an object representing a text file called @var{name} with the given
8254 @var{content} (a string or a bytevector) to be added to the store.
8256 This is the declarative counterpart of @code{text-file}.
8259 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
8260 [#:options '(#:local-build? #t)]
8261 Return an object representing the store item @var{name}, a file or
8262 directory computed by @var{gexp}. @var{options}
8263 is a list of additional arguments to pass to @code{gexp->derivation}.
8265 This is the declarative counterpart of @code{gexp->derivation}.
8268 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
8269 [#:guile (default-guile)] [#:module-path %load-path] @
8270 [#:system (%current-system)] [#:target #f]
8271 Return an executable script @var{name} that runs @var{exp} using
8272 @var{guile}, with @var{exp}'s imported modules in its search path.
8273 Look up @var{exp}'s modules in @var{module-path}.
8275 The example below builds a script that simply invokes the @command{ls}
8279 (use-modules (guix gexp) (gnu packages base))
8281 (gexp->script "list-files"
8282 #~(execl #$(file-append coreutils "/bin/ls")
8286 When ``running'' it through the store (@pxref{The Store Monad,
8287 @code{run-with-store}}), we obtain a derivation that produces an
8288 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
8291 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
8293 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
8297 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
8298 [#:guile #f] [#:module-path %load-path]
8299 Return an object representing the executable store item @var{name} that
8300 runs @var{gexp}. @var{guile} is the Guile package used to execute that
8301 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
8303 This is the declarative counterpart of @code{gexp->script}.
8306 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
8307 [#:set-load-path? #t] [#:module-path %load-path] @
8309 [#:guile (default-guile)]
8310 Return a derivation that builds a file @var{name} containing @var{exp}.
8311 When @var{splice?} is true, @var{exp} is considered to be a list of
8312 expressions that will be spliced in the resulting file.
8314 When @var{set-load-path?} is true, emit code in the resulting file to
8315 set @code{%load-path} and @code{%load-compiled-path} to honor
8316 @var{exp}'s imported modules. Look up @var{exp}'s modules in
8319 The resulting file holds references to all the dependencies of @var{exp}
8320 or a subset thereof.
8323 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} @
8324 [#:splice? #f] [#:set-load-path? #t]
8325 Return an object representing the Scheme file @var{name} that contains
8328 This is the declarative counterpart of @code{gexp->file}.
8331 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
8332 Return as a monadic value a derivation that builds a text file
8333 containing all of @var{text}. @var{text} may list, in addition to
8334 strings, objects of any type that can be used in a gexp: packages,
8335 derivations, local file objects, etc. The resulting store file holds
8336 references to all these.
8338 This variant should be preferred over @code{text-file} anytime the file
8339 to create will reference items from the store. This is typically the
8340 case when building a configuration file that embeds store file names,
8344 (define (profile.sh)
8345 ;; Return the name of a shell script in the store that
8346 ;; initializes the 'PATH' environment variable.
8347 (text-file* "profile.sh"
8348 "export PATH=" coreutils "/bin:"
8349 grep "/bin:" sed "/bin\n"))
8352 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
8353 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
8354 preventing them from being garbage-collected during its lifetime.
8357 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
8358 Return an object representing store file @var{name} containing
8359 @var{text}. @var{text} is a sequence of strings and file-like objects,
8363 (mixed-text-file "profile"
8364 "export PATH=" coreutils "/bin:" grep "/bin")
8367 This is the declarative counterpart of @code{text-file*}.
8370 @deffn {Scheme Procedure} file-union @var{name} @var{files}
8371 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
8372 Each item in @var{files} must be a two-element list where the first element is the
8373 file name to use in the new directory, and the second element is a gexp
8374 denoting the target file. Here's an example:
8378 `(("hosts" ,(plain-file "hosts"
8379 "127.0.0.1 localhost"))
8380 ("bashrc" ,(plain-file "bashrc"
8381 "alias ls='ls --color=auto'"))))
8384 This yields an @code{etc} directory containing these two files.
8387 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
8388 Return a directory that is the union of @var{things}, where @var{things} is a list of
8389 file-like objects denoting directories. For example:
8392 (directory-union "guile+emacs" (list guile emacs))
8395 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
8398 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
8399 Return a file-like object that expands to the concatenation of @var{obj}
8400 and @var{suffix}, where @var{obj} is a lowerable object and each
8401 @var{suffix} is a string.
8403 As an example, consider this gexp:
8406 (gexp->script "run-uname"
8407 #~(system* #$(file-append coreutils
8411 The same effect could be achieved with:
8414 (gexp->script "run-uname"
8415 #~(system* (string-append #$coreutils
8419 There is one difference though: in the @code{file-append} case, the
8420 resulting script contains the absolute file name as a string, whereas in
8421 the second case, the resulting script contains a @code{(string-append
8422 @dots{})} expression to construct the file name @emph{at run time}.
8425 @deffn {Scheme Syntax} let-system @var{system} @var{body}@dots{}
8426 @deffnx {Scheme Syntax} let-system (@var{system} @var{target}) @var{body}@dots{}
8427 Bind @var{system} to the currently targeted system---e.g.,
8428 @code{"x86_64-linux"}---within @var{body}.
8430 In the second case, additionally bind @var{target} to the current
8431 cross-compilation target---a GNU triplet such as
8432 @code{"arm-linux-gnueabihf"}---or @code{#f} if we are not
8435 @code{let-system} is useful in the occasional case where the object
8436 spliced into the gexp depends on the target system, as in this example:
8440 #+(let-system system
8441 (cond ((string-prefix? "armhf-" system)
8442 (file-append qemu "/bin/qemu-system-arm"))
8443 ((string-prefix? "x86_64-" system)
8444 (file-append qemu "/bin/qemu-system-x86_64"))
8447 "-net" "user" #$image)
8451 @deffn {Scheme Syntax} with-parameters ((@var{parameter} @var{value}) @dots{}) @var{exp}
8452 This macro is similar to the @code{parameterize} form for
8453 dynamically-bound @dfn{parameters} (@pxref{Parameters,,, guile, GNU
8454 Guile Reference Manual}). The key difference is that it takes effect
8455 when the file-like object returned by @var{exp} is lowered to a
8456 derivation or store item.
8458 A typical use of @code{with-parameters} is to force the system in effect
8462 (with-parameters ((%current-system "i686-linux"))
8466 The example above returns an object that corresponds to the i686 build
8467 of Coreutils, regardless of the current value of @code{%current-system}.
8471 Of course, in addition to gexps embedded in ``host'' code, there are
8472 also modules containing build tools. To make it clear that they are
8473 meant to be used in the build stratum, these modules are kept in the
8474 @code{(guix build @dots{})} name space.
8476 @cindex lowering, of high-level objects in gexps
8477 Internally, high-level objects are @dfn{lowered}, using their compiler,
8478 to either derivations or store items. For instance, lowering a package
8479 yields a derivation, and lowering a @code{plain-file} yields a store
8480 item. This is achieved using the @code{lower-object} monadic procedure.
8482 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
8484 Return as a value in @code{%store-monad} the derivation or store item
8485 corresponding to @var{obj} for @var{system}, cross-compiling for
8486 @var{target} if @var{target} is true. @var{obj} must be an object that
8487 has an associated gexp compiler, such as a @code{<package>}.
8490 @node Invoking guix repl
8491 @section Invoking @command{guix repl}
8493 @cindex REPL, read-eval-print loop, script
8494 The @command{guix repl} command makes it easier to program Guix in Guile
8495 by launching a Guile @dfn{read-eval-print loop} (REPL) for interactive
8496 programming (@pxref{Using Guile Interactively,,, guile,
8497 GNU Guile Reference Manual}), or by running Guile scripts
8498 (@pxref{Running Guile Scripts,,, guile,
8499 GNU Guile Reference Manual}).
8500 Compared to just launching the @command{guile}
8501 command, @command{guix repl} guarantees that all the Guix modules and all its
8502 dependencies are available in the search path.
8504 The general syntax is:
8507 guix repl @var{options} [@var{file} @var{args}]
8510 When a @var{file} argument is provided, @var{file} is
8511 executed as a Guile scripts:
8514 guix repl my-script.scm
8517 To pass arguments to the script, use @code{--} to prevent them from
8518 being interpreted as arguments to @command{guix repl} itself:
8521 guix repl -- my-script.scm --input=foo.txt
8524 To make a script executable directly from the shell, using the guix
8525 executable that is on the user's search path, add the following two
8526 lines at the top of the script:
8529 @code{#!/usr/bin/env -S guix repl --}
8533 Without a file name argument, a Guile REPL is started:
8537 scheme@@(guile-user)> ,use (gnu packages base)
8538 scheme@@(guile-user)> coreutils
8539 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
8543 In addition, @command{guix repl} implements a simple machine-readable REPL
8544 protocol for use by @code{(guix inferior)}, a facility to interact with
8545 @dfn{inferiors}, separate processes running a potentially different revision
8548 The available options are as follows:
8551 @item --type=@var{type}
8552 @itemx -t @var{type}
8553 Start a REPL of the given @var{TYPE}, which can be one of the following:
8557 This is default, and it spawns a standard full-featured Guile REPL.
8559 Spawn a REPL that uses the machine-readable protocol. This is the protocol
8560 that the @code{(guix inferior)} module speaks.
8563 @item --listen=@var{endpoint}
8564 By default, @command{guix repl} reads from standard input and writes to
8565 standard output. When this option is passed, it will instead listen for
8566 connections on @var{endpoint}. Here are examples of valid options:
8569 @item --listen=tcp:37146
8570 Accept connections on localhost on port 37146.
8572 @item --listen=unix:/tmp/socket
8573 Accept connections on the Unix-domain socket @file{/tmp/socket}.
8576 @item --load-path=@var{directory}
8577 @itemx -L @var{directory}
8578 Add @var{directory} to the front of the package module search path
8579 (@pxref{Package Modules}).
8581 This allows users to define their own packages and make them visible to
8585 Inhibit loading of the @file{~/.guile} file. By default, that
8586 configuration file is loaded when spawning a @code{guile} REPL.
8589 @c *********************************************************************
8593 This section describes Guix command-line utilities. Some of them are
8594 primarily targeted at developers and users who write new package
8595 definitions, while others are more generally useful. They complement
8596 the Scheme programming interface of Guix in a convenient way.
8599 * Invoking guix build:: Building packages from the command line.
8600 * Invoking guix edit:: Editing package definitions.
8601 * Invoking guix download:: Downloading a file and printing its hash.
8602 * Invoking guix hash:: Computing the cryptographic hash of a file.
8603 * Invoking guix import:: Importing package definitions.
8604 * Invoking guix refresh:: Updating package definitions.
8605 * Invoking guix lint:: Finding errors in package definitions.
8606 * Invoking guix size:: Profiling disk usage.
8607 * Invoking guix graph:: Visualizing the graph of packages.
8608 * Invoking guix publish:: Sharing substitutes.
8609 * Invoking guix challenge:: Challenging substitute servers.
8610 * Invoking guix copy:: Copying to and from a remote store.
8611 * Invoking guix container:: Process isolation.
8612 * Invoking guix weather:: Assessing substitute availability.
8613 * Invoking guix processes:: Listing client processes.
8616 @node Invoking guix build
8617 @section Invoking @command{guix build}
8619 @cindex package building
8620 @cindex @command{guix build}
8621 The @command{guix build} command builds packages or derivations and
8622 their dependencies, and prints the resulting store paths. Note that it
8623 does not modify the user's profile---this is the job of the
8624 @command{guix package} command (@pxref{Invoking guix package}). Thus,
8625 it is mainly useful for distribution developers.
8627 The general syntax is:
8630 guix build @var{options} @var{package-or-derivation}@dots{}
8633 As an example, the following command builds the latest versions of Emacs
8634 and of Guile, displays their build logs, and finally displays the
8635 resulting directories:
8638 guix build emacs guile
8641 Similarly, the following command builds all the available packages:
8644 guix build --quiet --keep-going \
8645 `guix package -A | cut -f1,2 --output-delimiter=@@`
8648 @var{package-or-derivation} may be either the name of a package found in
8649 the software distribution such as @code{coreutils} or
8650 @code{coreutils@@8.20}, or a derivation such as
8651 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
8652 package with the corresponding name (and optionally version) is searched
8653 for among the GNU distribution modules (@pxref{Package Modules}).
8655 Alternatively, the @option{--expression} option may be used to specify a
8656 Scheme expression that evaluates to a package; this is useful when
8657 disambiguating among several same-named packages or package variants is
8660 There may be zero or more @var{options}. The available options are
8661 described in the subsections below.
8664 * Common Build Options:: Build options for most commands.
8665 * Package Transformation Options:: Creating variants of packages.
8666 * Additional Build Options:: Options specific to 'guix build'.
8667 * Debugging Build Failures:: Real life packaging experience.
8670 @node Common Build Options
8671 @subsection Common Build Options
8673 A number of options that control the build process are common to
8674 @command{guix build} and other commands that can spawn builds, such as
8675 @command{guix package} or @command{guix archive}. These are the
8680 @item --load-path=@var{directory}
8681 @itemx -L @var{directory}
8682 Add @var{directory} to the front of the package module search path
8683 (@pxref{Package Modules}).
8685 This allows users to define their own packages and make them visible to
8686 the command-line tools.
8690 Keep the build tree of failed builds. Thus, if a build fails, its build
8691 tree is kept under @file{/tmp}, in a directory whose name is shown at
8692 the end of the build log. This is useful when debugging build issues.
8693 @xref{Debugging Build Failures}, for tips and tricks on how to debug
8696 This option implies @option{--no-offload}, and it has no effect when
8697 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
8698 Store, the @env{GUIX_DAEMON_SOCKET} variable}).
8702 Keep going when some of the derivations fail to build; return only once
8703 all the builds have either completed or failed.
8705 The default behavior is to stop as soon as one of the specified
8706 derivations has failed.
8710 Do not build the derivations.
8712 @anchor{fallback-option}
8714 When substituting a pre-built binary fails, fall back to building
8715 packages locally (@pxref{Substitution Failure}).
8717 @item --substitute-urls=@var{urls}
8718 @anchor{client-substitute-urls}
8719 Consider @var{urls} the whitespace-separated list of substitute source
8720 URLs, overriding the default list of URLs of @command{guix-daemon}
8721 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
8723 This means that substitutes may be downloaded from @var{urls}, provided
8724 they are signed by a key authorized by the system administrator
8725 (@pxref{Substitutes}).
8727 When @var{urls} is the empty string, substitutes are effectively
8730 @item --no-substitutes
8731 Do not use substitutes for build products. That is, always build things
8732 locally instead of allowing downloads of pre-built binaries
8733 (@pxref{Substitutes}).
8736 Do not ``graft'' packages. In practice, this means that package updates
8737 available as grafts are not applied. @xref{Security Updates}, for more
8738 information on grafts.
8740 @item --rounds=@var{n}
8741 Build each derivation @var{n} times in a row, and raise an error if
8742 consecutive build results are not bit-for-bit identical.
8744 This is a useful way to detect non-deterministic builds processes.
8745 Non-deterministic build processes are a problem because they make it
8746 practically impossible for users to @emph{verify} whether third-party
8747 binaries are genuine. @xref{Invoking guix challenge}, for more.
8749 Note that, currently, the differing build results are not kept around,
8750 so you will have to manually investigate in case of an error---e.g., by
8751 stashing one of the build results with @code{guix archive --export}
8752 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
8756 Do not use offload builds to other machines (@pxref{Daemon Offload
8757 Setup}). That is, always build things locally instead of offloading
8758 builds to remote machines.
8760 @item --max-silent-time=@var{seconds}
8761 When the build or substitution process remains silent for more than
8762 @var{seconds}, terminate it and report a build failure.
8764 By default, the daemon's setting is honored (@pxref{Invoking
8765 guix-daemon, @option{--max-silent-time}}).
8767 @item --timeout=@var{seconds}
8768 Likewise, when the build or substitution process lasts for more than
8769 @var{seconds}, terminate it and report a build failure.
8771 By default, the daemon's setting is honored (@pxref{Invoking
8772 guix-daemon, @option{--timeout}}).
8774 @c Note: This option is actually not part of %standard-build-options but
8775 @c most programs honor it.
8776 @cindex verbosity, of the command-line tools
8777 @cindex build logs, verbosity
8778 @item -v @var{level}
8779 @itemx --verbosity=@var{level}
8780 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
8781 output is produced, 1 is for quiet output, and 2 shows all the build log
8782 output on standard error.
8784 @item --cores=@var{n}
8786 Allow the use of up to @var{n} CPU cores for the build. The special
8787 value @code{0} means to use as many CPU cores as available.
8789 @item --max-jobs=@var{n}
8791 Allow at most @var{n} build jobs in parallel. @xref{Invoking
8792 guix-daemon, @option{--max-jobs}}, for details about this option and the
8793 equivalent @command{guix-daemon} option.
8795 @item --debug=@var{level}
8796 Produce debugging output coming from the build daemon. @var{level} must be an
8797 integer between 0 and 5; higher means more verbose output. Setting a level of
8798 4 or more may be helpful when debugging setup issues with the build daemon.
8802 Behind the scenes, @command{guix build} is essentially an interface to
8803 the @code{package-derivation} procedure of the @code{(guix packages)}
8804 module, and to the @code{build-derivations} procedure of the @code{(guix
8805 derivations)} module.
8807 In addition to options explicitly passed on the command line,
8808 @command{guix build} and other @command{guix} commands that support
8809 building honor the @env{GUIX_BUILD_OPTIONS} environment variable.
8811 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
8812 Users can define this variable to a list of command line options that
8813 will automatically be used by @command{guix build} and other
8814 @command{guix} commands that can perform builds, as in the example
8818 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
8821 These options are parsed independently, and the result is appended to
8822 the parsed command-line options.
8826 @node Package Transformation Options
8827 @subsection Package Transformation Options
8829 @cindex package variants
8830 Another set of command-line options supported by @command{guix build}
8831 and also @command{guix package} are @dfn{package transformation
8832 options}. These are options that make it possible to define @dfn{package
8833 variants}---for instance, packages built from different source code.
8834 This is a convenient way to create customized packages on the fly
8835 without having to type in the definitions of package variants
8836 (@pxref{Defining Packages}).
8840 @item --with-source=@var{source}
8841 @itemx --with-source=@var{package}=@var{source}
8842 @itemx --with-source=@var{package}@@@var{version}=@var{source}
8843 Use @var{source} as the source of @var{package}, and @var{version} as
8845 @var{source} must be a file name or a URL, as for @command{guix
8846 download} (@pxref{Invoking guix download}).
8848 When @var{package} is omitted,
8849 it is taken to be the package name specified on the
8850 command line that matches the base of @var{source}---e.g.,
8851 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
8852 package is @code{guile}.
8854 Likewise, when @var{version} is omitted, the version string is inferred from
8855 @var{source}; in the previous example, it is @code{2.0.10}.
8857 This option allows users to try out versions of packages other than the
8858 one provided by the distribution. The example below downloads
8859 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
8860 the @code{ed} package:
8863 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
8866 As a developer, @option{--with-source} makes it easy to test release
8870 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
8873 @dots{} or to build from a checkout in a pristine environment:
8876 $ git clone git://git.sv.gnu.org/guix.git
8877 $ guix build guix --with-source=guix@@1.0=./guix
8880 @item --with-input=@var{package}=@var{replacement}
8881 Replace dependency on @var{package} by a dependency on
8882 @var{replacement}. @var{package} must be a package name, and
8883 @var{replacement} must be a package specification such as @code{guile}
8884 or @code{guile@@1.8}.
8886 For instance, the following command builds Guix, but replaces its
8887 dependency on the current stable version of Guile with a dependency on
8888 the legacy version of Guile, @code{guile@@2.0}:
8891 guix build --with-input=guile=guile@@2.0 guix
8894 This is a recursive, deep replacement. So in this example, both
8895 @code{guix} and its dependency @code{guile-json} (which also depends on
8896 @code{guile}) get rebuilt against @code{guile@@2.0}.
8898 This is implemented using the @code{package-input-rewriting} Scheme
8899 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
8901 @item --with-graft=@var{package}=@var{replacement}
8902 This is similar to @option{--with-input} but with an important difference:
8903 instead of rebuilding the whole dependency chain, @var{replacement} is
8904 built and then @dfn{grafted} onto the binaries that were initially
8905 referring to @var{package}. @xref{Security Updates}, for more
8906 information on grafts.
8908 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
8909 and all its dependencies, replacing references to the version of GnuTLS
8910 they currently refer to:
8913 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
8916 This has the advantage of being much faster than rebuilding everything.
8917 But there is a caveat: it works if and only if @var{package} and
8918 @var{replacement} are strictly compatible---for example, if they provide
8919 a library, the application binary interface (ABI) of those libraries
8920 must be compatible. If @var{replacement} is somehow incompatible with
8921 @var{package}, then the resulting package may be unusable. Use with
8924 @item --with-git-url=@var{package}=@var{url}
8925 @cindex Git, using the latest commit
8926 @cindex latest commit, building
8927 Build @var{package} from the latest commit of the @code{master} branch of the
8928 Git repository at @var{url}. Git sub-modules of the repository are fetched,
8931 For example, the following command builds the NumPy Python library against the
8932 latest commit of the master branch of Python itself:
8935 guix build python-numpy \
8936 --with-git-url=python=https://github.com/python/cpython
8939 This option can also be combined with @option{--with-branch} or
8940 @option{--with-commit} (see below).
8942 @cindex continuous integration
8943 Obviously, since it uses the latest commit of the given branch, the result of
8944 such a command varies over time. Nevertheless it is a convenient way to
8945 rebuild entire software stacks against the latest commit of one or more
8946 packages. This is particularly useful in the context of continuous
8949 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
8950 consecutive accesses to the same repository. You may want to clean it up once
8951 in a while to save disk space.
8953 @item --with-branch=@var{package}=@var{branch}
8954 Build @var{package} from the latest commit of @var{branch}. If the
8955 @code{source} field of @var{package} is an origin with the @code{git-fetch}
8956 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
8957 repository URL is taken from that @code{source}. Otherwise you have to use
8958 @option{--with-git-url} to specify the URL of the Git repository.
8960 For instance, the following command builds @code{guile-sqlite3} from the
8961 latest commit of its @code{master} branch, and then builds @code{guix} (which
8962 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
8963 specific @code{guile-sqlite3} build:
8966 guix build --with-branch=guile-sqlite3=master cuirass
8969 @item --with-commit=@var{package}=@var{commit}
8970 This is similar to @option{--with-branch}, except that it builds from
8971 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
8972 Git commit SHA1 identifier or a tag.
8975 @node Additional Build Options
8976 @subsection Additional Build Options
8978 The command-line options presented below are specific to @command{guix
8985 Build quietly, without displaying the build log; this is equivalent to
8986 @option{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
8987 (or similar) and can always be retrieved using the @option{--log-file} option.
8989 @item --file=@var{file}
8990 @itemx -f @var{file}
8991 Build the package, derivation, or other file-like object that the code within
8992 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
8994 As an example, @var{file} might contain a package definition like this
8995 (@pxref{Defining Packages}):
8998 @include package-hello.scm
9001 The @var{file} may also contain a JSON representation of one or more
9002 package definitions. Running @code{guix build -f} on @file{hello.json}
9003 with the following contents would result in building the packages
9004 @code{myhello} and @code{greeter}:
9007 @verbatiminclude package-hello.json
9010 @item --manifest=@var{manifest}
9011 @itemx -m @var{manifest}
9012 Build all packages listed in the given @var{manifest}
9013 (@pxref{profile-manifest, @option{--manifest}}).
9015 @item --expression=@var{expr}
9016 @itemx -e @var{expr}
9017 Build the package or derivation @var{expr} evaluates to.
9019 For example, @var{expr} may be @code{(@@ (gnu packages guile)
9020 guile-1.8)}, which unambiguously designates this specific variant of
9021 version 1.8 of Guile.
9023 Alternatively, @var{expr} may be a G-expression, in which case it is used
9024 as a build program passed to @code{gexp->derivation}
9025 (@pxref{G-Expressions}).
9027 Lastly, @var{expr} may refer to a zero-argument monadic procedure
9028 (@pxref{The Store Monad}). The procedure must return a derivation as a
9029 monadic value, which is then passed through @code{run-with-store}.
9033 Build the source derivations of the packages, rather than the packages
9036 For instance, @code{guix build -S gcc} returns something like
9037 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
9040 The returned source tarball is the result of applying any patches and
9041 code snippets specified in the package @code{origin} (@pxref{Defining
9044 Note that @command{guix build -S} compiles the sources only of the
9045 specified packages. They do not include the sources of statically
9046 linked dependencies and by themselves are insufficient for reproducing
9050 Fetch and return the source of @var{package-or-derivation} and all their
9051 dependencies, recursively. This is a handy way to obtain a local copy
9052 of all the source code needed to build @var{packages}, allowing you to
9053 eventually build them even without network access. It is an extension
9054 of the @option{--source} option and can accept one of the following
9055 optional argument values:
9059 This value causes the @option{--sources} option to behave in the same way
9060 as the @option{--source} option.
9063 Build the source derivations of all packages, including any source that
9064 might be listed as @code{inputs}. This is the default value.
9067 $ guix build --sources tzdata
9068 The following derivations will be built:
9069 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
9070 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
9074 Build the source derivations of all packages, as well of all transitive
9075 inputs to the packages. This can be used e.g.@: to
9076 prefetch package source for later offline building.
9079 $ guix build --sources=transitive tzdata
9080 The following derivations will be built:
9081 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
9082 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
9083 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
9084 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
9085 /gnu/store/@dots{}-make-4.1.tar.xz.drv
9086 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
9092 @item --system=@var{system}
9093 @itemx -s @var{system}
9094 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
9095 the system type of the build host. The @command{guix build} command allows
9096 you to repeat this option several times, in which case it builds for all the
9097 specified systems; other commands ignore extraneous @option{-s} options.
9100 The @option{--system} flag is for @emph{native} compilation and must not
9101 be confused with cross-compilation. See @option{--target} below for
9102 information on cross-compilation.
9105 An example use of this is on Linux-based systems, which can emulate
9106 different personalities. For instance, passing
9107 @option{--system=i686-linux} on an @code{x86_64-linux} system or
9108 @option{--system=armhf-linux} on an @code{aarch64-linux} system allows
9109 you to build packages in a complete 32-bit environment.
9112 Building for an @code{armhf-linux} system is unconditionally enabled on
9113 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
9114 allow for this functionality, notably the ThunderX.
9117 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
9118 is enabled (@pxref{Virtualization Services,
9119 @code{qemu-binfmt-service-type}}), you can build for any system for
9120 which a QEMU @code{binfmt_misc} handler is installed.
9122 Builds for a system other than that of the machine you are using can
9123 also be offloaded to a remote machine of the right architecture.
9124 @xref{Daemon Offload Setup}, for more information on offloading.
9126 @item --target=@var{triplet}
9127 @cindex cross-compilation
9128 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
9129 as @code{"aarch64-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
9130 configuration triplets,, autoconf, Autoconf}).
9132 @anchor{build-check}
9134 @cindex determinism, checking
9135 @cindex reproducibility, checking
9136 Rebuild @var{package-or-derivation}, which are already available in the
9137 store, and raise an error if the build results are not bit-for-bit
9140 This mechanism allows you to check whether previously installed
9141 substitutes are genuine (@pxref{Substitutes}), or whether the build result
9142 of a package is deterministic. @xref{Invoking guix challenge}, for more
9143 background information and tools.
9145 When used in conjunction with @option{--keep-failed}, the differing
9146 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
9147 This makes it easy to look for differences between the two results.
9150 @cindex repairing store items
9151 @cindex corruption, recovering from
9152 Attempt to repair the specified store items, if they are corrupt, by
9153 re-downloading or rebuilding them.
9155 This operation is not atomic and thus restricted to @code{root}.
9159 Return the derivation paths, not the output paths, of the given
9162 @item --root=@var{file}
9163 @itemx -r @var{file}
9164 @cindex GC roots, adding
9165 @cindex garbage collector roots, adding
9166 Make @var{file} a symlink to the result, and register it as a garbage
9169 Consequently, the results of this @command{guix build} invocation are
9170 protected from garbage collection until @var{file} is removed. When
9171 that option is omitted, build results are eligible for garbage
9172 collection as soon as the build completes. @xref{Invoking guix gc}, for
9176 @cindex build logs, access
9177 Return the build log file names or URLs for the given
9178 @var{package-or-derivation}, or raise an error if build logs are
9181 This works regardless of how packages or derivations are specified. For
9182 instance, the following invocations are equivalent:
9185 guix build --log-file `guix build -d guile`
9186 guix build --log-file `guix build guile`
9187 guix build --log-file guile
9188 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
9191 If a log is unavailable locally, and unless @option{--no-substitutes} is
9192 passed, the command looks for a corresponding log on one of the
9193 substitute servers (as specified with @option{--substitute-urls}).
9195 So for instance, imagine you want to see the build log of GDB on MIPS,
9196 but you are actually on an @code{x86_64} machine:
9199 $ guix build --log-file gdb -s aarch64-linux
9200 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
9203 You can freely access a huge library of build logs!
9206 @node Debugging Build Failures
9207 @subsection Debugging Build Failures
9209 @cindex build failures, debugging
9210 When defining a new package (@pxref{Defining Packages}), you will
9211 probably find yourself spending some time debugging and tweaking the
9212 build until it succeeds. To do that, you need to operate the build
9213 commands yourself in an environment as close as possible to the one the
9216 To that end, the first thing to do is to use the @option{--keep-failed}
9217 or @option{-K} option of @command{guix build}, which will keep the
9218 failed build tree in @file{/tmp} or whatever directory you specified as
9219 @env{TMPDIR} (@pxref{Invoking guix build, @option{--keep-failed}}).
9221 From there on, you can @command{cd} to the failed build tree and source
9222 the @file{environment-variables} file, which contains all the
9223 environment variable definitions that were in place when the build
9224 failed. So let's say you're debugging a build failure in package
9225 @code{foo}; a typical session would look like this:
9229 @dots{} @i{build fails}
9230 $ cd /tmp/guix-build-foo.drv-0
9231 $ source ./environment-variables
9235 Now, you can invoke commands as if you were the daemon (almost) and
9236 troubleshoot your build process.
9238 Sometimes it happens that, for example, a package's tests pass when you
9239 run them manually but they fail when the daemon runs them. This can
9240 happen because the daemon runs builds in containers where, unlike in our
9241 environment above, network access is missing, @file{/bin/sh} does not
9242 exist, etc. (@pxref{Build Environment Setup}).
9244 In such cases, you may need to run inspect the build process from within
9245 a container similar to the one the build daemon creates:
9250 $ cd /tmp/guix-build-foo.drv-0
9251 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
9252 [env]# source ./environment-variables
9256 Here, @command{guix environment -C} creates a container and spawns a new
9257 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
9258 strace gdb} part adds the @command{strace} and @command{gdb} commands to
9259 the container, which you may find handy while debugging. The
9260 @option{--no-grafts} option makes sure we get the exact same
9261 environment, with ungrafted packages (@pxref{Security Updates}, for more
9264 To get closer to a container like that used by the build daemon, we can
9265 remove @file{/bin/sh}:
9271 (Don't worry, this is harmless: this is all happening in the throw-away
9272 container created by @command{guix environment}.)
9274 The @command{strace} command is probably not in the search path, but we
9278 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
9281 In this way, not only you will have reproduced the environment variables
9282 the daemon uses, you will also be running the build process in a container
9283 similar to the one the daemon uses.
9286 @node Invoking guix edit
9287 @section Invoking @command{guix edit}
9289 @cindex @command{guix edit}
9290 @cindex package definition, editing
9291 So many packages, so many source files! The @command{guix edit} command
9292 facilitates the life of users and packagers by pointing their editor at
9293 the source file containing the definition of the specified packages.
9297 guix edit gcc@@4.9 vim
9301 launches the program specified in the @env{VISUAL} or in the
9302 @env{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
9305 If you are using a Guix Git checkout (@pxref{Building from Git}), or
9306 have created your own packages on @env{GUIX_PACKAGE_PATH}
9307 (@pxref{Package Modules}), you will be able to edit the package
9308 recipes. In other cases, you will be able to examine the read-only recipes
9309 for packages currently in the store.
9311 Instead of @env{GUIX_PACKAGE_PATH}, the command-line option
9312 @option{--load-path=@var{directory}} (or in short @option{-L
9313 @var{directory}}) allows you to add @var{directory} to the front of the
9314 package module search path and so make your own packages visible.
9316 @node Invoking guix download
9317 @section Invoking @command{guix download}
9319 @cindex @command{guix download}
9320 @cindex downloading package sources
9321 When writing a package definition, developers typically need to download
9322 a source tarball, compute its SHA256 hash, and write that
9323 hash in the package definition (@pxref{Defining Packages}). The
9324 @command{guix download} tool helps with this task: it downloads a file
9325 from the given URI, adds it to the store, and prints both its file name
9326 in the store and its SHA256 hash.
9328 The fact that the downloaded file is added to the store saves bandwidth:
9329 when the developer eventually tries to build the newly defined package
9330 with @command{guix build}, the source tarball will not have to be
9331 downloaded again because it is already in the store. It is also a
9332 convenient way to temporarily stash files, which may be deleted
9333 eventually (@pxref{Invoking guix gc}).
9335 The @command{guix download} command supports the same URIs as used in
9336 package definitions. In particular, it supports @code{mirror://} URIs.
9337 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
9338 Guile bindings for GnuTLS are available in the user's environment; when
9339 they are not available, an error is raised. @xref{Guile Preparations,
9340 how to install the GnuTLS bindings for Guile,, gnutls-guile,
9341 GnuTLS-Guile}, for more information.
9343 @command{guix download} verifies HTTPS server certificates by loading
9344 the certificates of X.509 authorities from the directory pointed to by
9345 the @env{SSL_CERT_DIR} environment variable (@pxref{X.509
9346 Certificates}), unless @option{--no-check-certificate} is used.
9348 The following options are available:
9351 @item --hash=@var{algorithm}
9352 @itemx -H @var{algorithm}
9353 Compute a hash using the specified @var{algorithm}. @xref{Invoking guix
9354 hash}, for more information.
9356 @item --format=@var{fmt}
9358 Write the hash in the format specified by @var{fmt}. For more
9359 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
9361 @item --no-check-certificate
9362 Do not validate the X.509 certificates of HTTPS servers.
9364 When using this option, you have @emph{absolutely no guarantee} that you
9365 are communicating with the authentic server responsible for the given
9366 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
9368 @item --output=@var{file}
9369 @itemx -o @var{file}
9370 Save the downloaded file to @var{file} instead of adding it to the
9374 @node Invoking guix hash
9375 @section Invoking @command{guix hash}
9377 @cindex @command{guix hash}
9378 The @command{guix hash} command computes the hash of a file.
9379 It is primarily a convenience tool for anyone contributing to the
9380 distribution: it computes the cryptographic hash of a file, which can be
9381 used in the definition of a package (@pxref{Defining Packages}).
9383 The general syntax is:
9386 guix hash @var{option} @var{file}
9389 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
9390 hash of data read from standard input. @command{guix hash} has the
9395 @item --hash=@var{algorithm}
9396 @itemx -H @var{algorithm}
9397 Compute a hash using the specified @var{algorithm}, @code{sha256} by
9400 @var{algorithm} must the name of a cryptographic hash algorithm
9401 supported by Libgcrypt @i{via} Guile-Gcrypt---e.g., @code{sha512} or
9402 @code{sha3-256} (@pxref{Hash Functions,,, guile-gcrypt, Guile-Gcrypt
9405 @item --format=@var{fmt}
9407 Write the hash in the format specified by @var{fmt}.
9409 Supported formats: @code{base64}, @code{nix-base32}, @code{base32}, @code{base16}
9410 (@code{hex} and @code{hexadecimal} can be used as well).
9412 If the @option{--format} option is not specified, @command{guix hash}
9413 will output the hash in @code{nix-base32}. This representation is used
9414 in the definitions of packages.
9418 Compute the hash on @var{file} recursively.
9420 In this case, the hash is computed on an archive containing @var{file},
9421 including its children if it is a directory. Some of the metadata of
9422 @var{file} is part of the archive; for instance, when @var{file} is a
9423 regular file, the hash is different depending on whether @var{file} is
9424 executable or not. Metadata such as time stamps has no impact on the
9425 hash (@pxref{Invoking guix archive}).
9426 @c FIXME: Replace xref above with xref to an ``Archive'' section when
9431 When combined with @option{--recursive}, exclude version control system
9432 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.).
9435 As an example, here is how you would compute the hash of a Git checkout,
9436 which is useful when using the @code{git-fetch} method (@pxref{origin
9440 $ git clone http://example.org/foo.git
9446 @node Invoking guix import
9447 @section Invoking @command{guix import}
9449 @cindex importing packages
9450 @cindex package import
9451 @cindex package conversion
9452 @cindex Invoking @command{guix import}
9453 The @command{guix import} command is useful for people who would like to
9454 add a package to the distribution with as little work as
9455 possible---a legitimate demand. The command knows of a few
9456 repositories from which it can ``import'' package metadata. The result
9457 is a package definition, or a template thereof, in the format we know
9458 (@pxref{Defining Packages}).
9460 The general syntax is:
9463 guix import @var{importer} @var{options}@dots{}
9466 @var{importer} specifies the source from which to import package
9467 metadata, and @var{options} specifies a package identifier and other
9468 options specific to @var{importer}.
9470 Some of the importers rely on the ability to run the @command{gpgv} command.
9471 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
9474 Currently, the available ``importers'' are:
9478 Import metadata for the given GNU package. This provides a template
9479 for the latest version of that GNU package, including the hash of its
9480 source tarball, and its canonical synopsis and description.
9482 Additional information such as the package dependencies and its
9483 license needs to be figured out manually.
9485 For example, the following command returns a package definition for
9489 guix import gnu hello
9492 Specific command-line options are:
9495 @item --key-download=@var{policy}
9496 As for @command{guix refresh}, specify the policy to handle missing
9497 OpenPGP keys when verifying the package signature. @xref{Invoking guix
9498 refresh, @option{--key-download}}.
9503 Import metadata from the @uref{https://pypi.python.org/, Python Package
9504 Index}. Information is taken from the JSON-formatted description
9505 available at @code{pypi.python.org} and usually includes all the relevant
9506 information, including package dependencies. For maximum efficiency, it
9507 is recommended to install the @command{unzip} utility, so that the
9508 importer can unzip Python wheels and gather data from them.
9510 The command below imports metadata for the @code{itsdangerous} Python
9514 guix import pypi itsdangerous
9520 Traverse the dependency graph of the given upstream package recursively
9521 and generate package expressions for all those packages that are not yet
9527 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
9528 is taken from the JSON-formatted description available at
9529 @code{rubygems.org} and includes most relevant information, including
9530 runtime dependencies. There are some caveats, however. The metadata
9531 doesn't distinguish between synopses and descriptions, so the same string
9532 is used for both fields. Additionally, the details of non-Ruby
9533 dependencies required to build native extensions is unavailable and left
9534 as an exercise to the packager.
9536 The command below imports metadata for the @code{rails} Ruby package:
9539 guix import gem rails
9545 Traverse the dependency graph of the given upstream package recursively
9546 and generate package expressions for all those packages that are not yet
9552 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
9553 Information is taken from the JSON-formatted metadata provided through
9554 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
9555 relevant information, such as module dependencies. License information
9556 should be checked closely. If Perl is available in the store, then the
9557 @code{corelist} utility will be used to filter core modules out of the
9558 list of dependencies.
9560 The command command below imports metadata for the Acme::Boolean Perl
9564 guix import cpan Acme::Boolean
9569 @cindex Bioconductor
9570 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
9571 central repository for the @uref{https://r-project.org, GNU@tie{}R
9572 statistical and graphical environment}.
9574 Information is extracted from the @file{DESCRIPTION} file of the package.
9576 The command command below imports metadata for the Cairo R package:
9579 guix import cran Cairo
9582 When @option{--recursive} is added, the importer will traverse the
9583 dependency graph of the given upstream package recursively and generate
9584 package expressions for all those packages that are not yet in Guix.
9586 When @option{--archive=bioconductor} is added, metadata is imported from
9587 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
9588 packages for for the analysis and comprehension of high-throughput
9589 genomic data in bioinformatics.
9591 Information is extracted from the @file{DESCRIPTION} file contained in the
9594 The command below imports metadata for the GenomicRanges R package:
9597 guix import cran --archive=bioconductor GenomicRanges
9600 Finally, you can also import R packages that have not yet been published on
9601 CRAN or Bioconductor as long as they are in a git repository. Use
9602 @option{--archive=git} followed by the URL of the git repository:
9605 guix import cran --archive=git https://github.com/immunogenomics/harmony
9611 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
9612 comprehensive TeX archive network for TeX packages that are part of the
9613 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
9615 Information about the package is obtained through the XML API provided
9616 by CTAN, while the source code is downloaded from the SVN repository of
9617 the Tex Live project. This is done because the CTAN does not keep
9620 The command command below imports metadata for the @code{fontspec}
9624 guix import texlive fontspec
9627 When @option{--archive=@var{directory}} is added, the source code is
9628 downloaded not from the @file{latex} sub-directory of the
9629 @file{texmf-dist/source} tree in the TeX Live SVN repository, but from
9630 the specified sibling @var{directory} under the same root.
9632 The command below imports metadata for the @code{ifxetex} package from
9633 CTAN while fetching the sources from the directory
9634 @file{texmf/source/generic}:
9637 guix import texlive --archive=generic ifxetex
9641 @cindex JSON, import
9642 Import package metadata from a local JSON file. Consider the following
9643 example package definition in JSON format:
9649 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
9650 "build-system": "gnu",
9651 "home-page": "https://www.gnu.org/software/hello/",
9652 "synopsis": "Hello, GNU world: An example GNU package",
9653 "description": "GNU Hello prints a greeting.",
9654 "license": "GPL-3.0+",
9655 "native-inputs": ["gettext"]
9659 The field names are the same as for the @code{<package>} record
9660 (@xref{Defining Packages}). References to other packages are provided
9661 as JSON lists of quoted package specification strings such as
9662 @code{guile} or @code{guile@@2.0}.
9664 The importer also supports a more explicit source definition using the
9665 common fields for @code{<origin>} records:
9671 "method": "url-fetch",
9672 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
9674 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
9681 The command below reads metadata from the JSON file @code{hello.json}
9682 and outputs a package expression:
9685 guix import json hello.json
9689 Import metadata from a local copy of the source of the
9690 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
9691 relies on the @command{nix-instantiate} command of
9692 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
9693 typically written in a mixture of Nix-language and Bash code. This
9694 command only imports the high-level package structure that is written in
9695 the Nix language. It normally includes all the basic fields of a
9698 When importing a GNU package, the synopsis and descriptions are replaced
9699 by their canonical upstream variant.
9701 Usually, you will first need to do:
9704 export NIX_REMOTE=daemon
9708 so that @command{nix-instantiate} does not try to open the Nix database.
9710 As an example, the command below imports the package definition of
9711 LibreOffice (more precisely, it imports the definition of the package
9712 bound to the @code{libreoffice} top-level attribute):
9715 guix import nix ~/path/to/nixpkgs libreoffice
9720 Import metadata from the Haskell community's central package archive
9721 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
9722 Cabal files and includes all the relevant information, including package
9725 Specific command-line options are:
9730 Read a Cabal file from standard input.
9731 @item --no-test-dependencies
9733 Do not include dependencies required only by the test suites.
9734 @item --cabal-environment=@var{alist}
9735 @itemx -e @var{alist}
9736 @var{alist} is a Scheme alist defining the environment in which the
9737 Cabal conditionals are evaluated. The accepted keys are: @code{os},
9738 @code{arch}, @code{impl} and a string representing the name of a flag.
9739 The value associated with a flag has to be either the symbol
9740 @code{true} or @code{false}. The value associated with other keys
9741 has to conform to the Cabal file format definition. The default value
9742 associated with the keys @code{os}, @code{arch} and @code{impl} is
9743 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
9746 Traverse the dependency graph of the given upstream package recursively
9747 and generate package expressions for all those packages that are not yet
9751 The command below imports metadata for the latest version of the
9752 HTTP Haskell package without including test dependencies and
9753 specifying the value of the flag @samp{network-uri} as @code{false}:
9756 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
9759 A specific package version may optionally be specified by following the
9760 package name by an at-sign and a version number as in the following example:
9763 guix import hackage mtl@@2.1.3.1
9768 The @code{stackage} importer is a wrapper around the @code{hackage} one.
9769 It takes a package name, looks up the package version included in a
9770 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
9771 release and uses the @code{hackage} importer to retrieve its metadata.
9772 Note that it is up to you to select an LTS release compatible with the
9773 GHC compiler used by Guix.
9775 Specific command-line options are:
9778 @item --no-test-dependencies
9780 Do not include dependencies required only by the test suites.
9781 @item --lts-version=@var{version}
9782 @itemx -l @var{version}
9783 @var{version} is the desired LTS release version. If omitted the latest
9787 Traverse the dependency graph of the given upstream package recursively
9788 and generate package expressions for all those packages that are not yet
9792 The command below imports metadata for the HTTP Haskell package
9793 included in the LTS Stackage release version 7.18:
9796 guix import stackage --lts-version=7.18 HTTP
9801 Import metadata from an Emacs Lisp Package Archive (ELPA) package
9802 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
9804 Specific command-line options are:
9807 @item --archive=@var{repo}
9808 @itemx -a @var{repo}
9809 @var{repo} identifies the archive repository from which to retrieve the
9810 information. Currently the supported repositories and their identifiers
9814 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
9815 identifier. This is the default.
9817 Packages from @code{elpa.gnu.org} are signed with one of the keys
9818 contained in the GnuPG keyring at
9819 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
9820 @code{emacs} package (@pxref{Package Installation, ELPA package
9821 signatures,, emacs, The GNU Emacs Manual}).
9824 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
9825 @code{melpa-stable} identifier.
9828 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
9834 Traverse the dependency graph of the given upstream package recursively
9835 and generate package expressions for all those packages that are not yet
9841 Import metadata from the crates.io Rust package repository
9842 @uref{https://crates.io, crates.io}, as in this example:
9845 guix import crate blake2-rfc
9848 The crate importer also allows you to specify a version string:
9851 guix import crate constant-time-eq@@0.1.0
9854 Additional options include:
9859 Traverse the dependency graph of the given upstream package recursively
9860 and generate package expressions for all those packages that are not yet
9867 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
9868 repository used by the OCaml community.
9871 The structure of the @command{guix import} code is modular. It would be
9872 useful to have more importers for other package formats, and your help
9873 is welcome here (@pxref{Contributing}).
9875 @node Invoking guix refresh
9876 @section Invoking @command{guix refresh}
9878 @cindex @command {guix refresh}
9879 The primary audience of the @command{guix refresh} command is developers
9880 of the GNU software distribution. By default, it reports any packages
9881 provided by the distribution that are outdated compared to the latest
9882 upstream version, like this:
9886 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
9887 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
9890 Alternatively, one can specify packages to consider, in which case a
9891 warning is emitted for packages that lack an updater:
9894 $ guix refresh coreutils guile guile-ssh
9895 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
9896 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
9899 @command{guix refresh} browses the upstream repository of each package and determines
9900 the highest version number of the releases therein. The command
9901 knows how to update specific types of packages: GNU packages, ELPA
9902 packages, etc.---see the documentation for @option{--type} below. There
9903 are many packages, though, for which it lacks a method to determine
9904 whether a new upstream release is available. However, the mechanism is
9905 extensible, so feel free to get in touch with us to add a new method!
9910 Consider the packages specified, and all the packages upon which they depend.
9913 $ guix refresh --recursive coreutils
9914 gnu/packages/acl.scm:35:2: warning: no updater for acl
9915 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
9916 gnu/packages/xml.scm:68:2: warning: no updater for expat
9917 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
9923 Sometimes the upstream name differs from the package name used in Guix,
9924 and @command{guix refresh} needs a little help. Most updaters honor the
9925 @code{upstream-name} property in package definitions, which can be used
9929 (define-public network-manager
9931 (name "network-manager")
9933 (properties '((upstream-name . "NetworkManager")))))
9936 When passed @option{--update}, it modifies distribution source files to
9937 update the version numbers and source tarball hashes of those package
9938 recipes (@pxref{Defining Packages}). This is achieved by downloading
9939 each package's latest source tarball and its associated OpenPGP
9940 signature, authenticating the downloaded tarball against its signature
9941 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
9942 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
9945 key used to sign the tarball is missing from the user's keyring, an
9946 attempt is made to automatically retrieve it from a public key server;
9947 when this is successful, the key is added to the user's keyring; otherwise,
9948 @command{guix refresh} reports an error.
9950 The following options are supported:
9954 @item --expression=@var{expr}
9955 @itemx -e @var{expr}
9956 Consider the package @var{expr} evaluates to.
9958 This is useful to precisely refer to a package, as in this example:
9961 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
9964 This command lists the dependents of the ``final'' libc (essentially all
9969 Update distribution source files (package recipes) in place. This is
9970 usually run from a checkout of the Guix source tree (@pxref{Running
9971 Guix Before It Is Installed}):
9974 $ ./pre-inst-env guix refresh -s non-core -u
9977 @xref{Defining Packages}, for more information on package definitions.
9979 @item --select=[@var{subset}]
9980 @itemx -s @var{subset}
9981 Select all the packages in @var{subset}, one of @code{core} or
9984 The @code{core} subset refers to all the packages at the core of the
9985 distribution---i.e., packages that are used to build ``everything
9986 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
9987 changing one of these packages in the distribution entails a rebuild of
9988 all the others. Thus, such updates are an inconvenience to users in
9989 terms of build time or bandwidth used to achieve the upgrade.
9991 The @code{non-core} subset refers to the remaining packages. It is
9992 typically useful in cases where an update of the core packages would be
9995 @item --manifest=@var{file}
9996 @itemx -m @var{file}
9997 Select all the packages from the manifest in @var{file}. This is useful to
9998 check if any packages of the user manifest can be updated.
10000 @item --type=@var{updater}
10001 @itemx -t @var{updater}
10002 Select only packages handled by @var{updater} (may be a comma-separated
10003 list of updaters). Currently, @var{updater} may be one of:
10007 the updater for GNU packages;
10009 the updater for GNOME packages;
10011 the updater for KDE packages;
10013 the updater for X.org packages;
10015 the updater for packages hosted on kernel.org;
10017 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
10019 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
10021 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
10023 the updater for @uref{https://www.cpan.org/, CPAN} packages;
10025 the updater for @uref{https://pypi.python.org, PyPI} packages.
10027 the updater for @uref{https://rubygems.org, RubyGems} packages.
10029 the updater for @uref{https://github.com, GitHub} packages.
10031 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
10033 the updater for @uref{https://www.stackage.org, Stackage} packages.
10035 the updater for @uref{https://crates.io, Crates} packages.
10037 the updater for @uref{https://launchpad.net, Launchpad} packages.
10040 For instance, the following command only checks for updates of Emacs
10041 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
10044 $ guix refresh --type=elpa,cran
10045 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
10046 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
10051 In addition, @command{guix refresh} can be passed one or more package
10052 names, as in this example:
10055 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
10059 The command above specifically updates the @code{emacs} and
10060 @code{idutils} packages. The @option{--select} option would have no
10061 effect in this case.
10063 When considering whether to upgrade a package, it is sometimes
10064 convenient to know which packages would be affected by the upgrade and
10065 should be checked for compatibility. For this the following option may
10066 be used when passing @command{guix refresh} one or more package names:
10070 @item --list-updaters
10072 List available updaters and exit (see @option{--type} above).
10074 For each updater, display the fraction of packages it covers; at the
10075 end, display the fraction of packages covered by all these updaters.
10077 @item --list-dependent
10079 List top-level dependent packages that would need to be rebuilt as a
10080 result of upgrading one or more packages.
10082 @xref{Invoking guix graph, the @code{reverse-package} type of
10083 @command{guix graph}}, for information on how to visualize the list of
10084 dependents of a package.
10088 Be aware that the @option{--list-dependent} option only
10089 @emph{approximates} the rebuilds that would be required as a result of
10090 an upgrade. More rebuilds might be required under some circumstances.
10093 $ guix refresh --list-dependent flex
10094 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
10095 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
10098 The command above lists a set of packages that could be built to check
10099 for compatibility with an upgraded @code{flex} package.
10103 @item --list-transitive
10104 List all the packages which one or more packages depend upon.
10107 $ guix refresh --list-transitive flex
10108 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
10109 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{}
10114 The command above lists a set of packages which, when changed, would cause
10115 @code{flex} to be rebuilt.
10117 The following options can be used to customize GnuPG operation:
10121 @item --gpg=@var{command}
10122 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
10123 for in @code{$PATH}.
10125 @item --keyring=@var{file}
10126 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
10127 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
10128 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
10129 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
10130 information on a tool to manipulate keybox files).
10132 When this option is omitted, @command{guix refresh} uses
10133 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
10134 signing keys. OpenPGP signatures are checked against keys from this keyring;
10135 missing keys are downloaded to this keyring as well (see
10136 @option{--key-download} below).
10138 You can export keys from your default GPG keyring into a keybox file using
10139 commands like this one:
10142 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
10145 Likewise, you can fetch keys to a specific keybox file like this:
10148 gpg --no-default-keyring --keyring mykeyring.kbx \
10149 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
10152 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
10153 Privacy Guard}, for more information on GPG's @option{--keyring} option.
10155 @item --key-download=@var{policy}
10156 Handle missing OpenPGP keys according to @var{policy}, which may be one
10161 Always download missing OpenPGP keys from the key server, and add them
10162 to the user's GnuPG keyring.
10165 Never try to download missing OpenPGP keys. Instead just bail out.
10168 When a package signed with an unknown OpenPGP key is encountered, ask
10169 the user whether to download it or not. This is the default behavior.
10172 @item --key-server=@var{host}
10173 Use @var{host} as the OpenPGP key server when importing a public key.
10175 @item --load-path=@var{directory}
10176 Add @var{directory} to the front of the package module search path
10177 (@pxref{Package Modules}).
10179 This allows users to define their own packages and make them visible to
10180 the command-line tools.
10184 The @code{github} updater uses the
10185 @uref{https://developer.github.com/v3/, GitHub API} to query for new
10186 releases. When used repeatedly e.g.@: when refreshing all packages,
10187 GitHub will eventually refuse to answer any further API requests. By
10188 default 60 API requests per hour are allowed, and a full refresh on all
10189 GitHub packages in Guix requires more than this. Authentication with
10190 GitHub through the use of an API token alleviates these limits. To use
10191 an API token, set the environment variable @env{GUIX_GITHUB_TOKEN} to a
10192 token procured from @uref{https://github.com/settings/tokens} or
10196 @node Invoking guix lint
10197 @section Invoking @command{guix lint}
10199 @cindex @command{guix lint}
10200 @cindex package, checking for errors
10201 The @command{guix lint} command is meant to help package developers avoid
10202 common errors and use a consistent style. It runs a number of checks on
10203 a given set of packages in order to find common mistakes in their
10204 definitions. Available @dfn{checkers} include (see
10205 @option{--list-checkers} for a complete list):
10210 Validate certain typographical and stylistic rules about package
10211 descriptions and synopses.
10213 @item inputs-should-be-native
10214 Identify inputs that should most likely be native inputs.
10220 @itemx source-file-name
10221 Probe @code{home-page} and @code{source} URLs and report those that are
10222 invalid. Suggest a @code{mirror://} URL when applicable. If the
10223 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
10224 URL. Check that the source file name is meaningful, e.g.@: is not just a
10225 version number or ``git-checkout'', without a declared @code{file-name}
10226 (@pxref{origin Reference}).
10228 @item source-unstable-tarball
10229 Parse the @code{source} URL to determine if a tarball from GitHub is
10230 autogenerated or if it is a release tarball. Unfortunately GitHub's
10231 autogenerated tarballs are sometimes regenerated.
10234 Check that the derivation of the given packages can be successfully
10235 computed for all the supported systems (@pxref{Derivations}).
10237 @item profile-collisions
10238 Check whether installing the given packages in a profile would lead to
10239 collisions. Collisions occur when several packages with the same name
10240 but a different version or a different store file name are propagated.
10241 @xref{package Reference, @code{propagated-inputs}}, for more information
10242 on propagated inputs.
10245 @cindex Software Heritage, source code archive
10246 @cindex archival of source code, Software Heritage
10247 Checks whether the package's source code is archived at
10248 @uref{https://www.softwareheritage.org, Software Heritage}.
10250 When the source code that is not archived comes from a version-control system
10251 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
10252 ``save'' request so that it eventually archives it. This ensures that the
10253 source will remain available in the long term, and that Guix can fall back to
10254 Software Heritage should the source code disappear from its original host.
10255 The status of recent ``save'' requests can be
10256 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
10258 When source code is a tarball obtained with @code{url-fetch}, simply print a
10259 message when it is not archived. As of this writing, Software Heritage does
10260 not allow requests to save arbitrary tarballs; we are working on ways to
10261 ensure that non-VCS source code is also archived.
10264 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
10265 request rate per IP address}. When the limit is reached, @command{guix lint}
10266 prints a message and the @code{archival} checker stops doing anything until
10267 that limit has been reset.
10270 @cindex security vulnerabilities
10271 @cindex CVE, Common Vulnerabilities and Exposures
10272 Report known vulnerabilities found in the Common Vulnerabilities and
10273 Exposures (CVE) databases of the current and past year
10274 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
10277 To view information about a particular vulnerability, visit pages such as:
10281 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
10283 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
10287 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
10288 @code{CVE-2015-7554}.
10290 Package developers can specify in package recipes the
10291 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
10292 name and version of the package when they differ from the name or version
10293 that Guix uses, as in this example:
10299 ;; CPE calls this package "grub2".
10300 (properties '((cpe-name . "grub2")
10301 (cpe-version . "2.3"))))
10304 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
10305 Some entries in the CVE database do not specify which version of a
10306 package they apply to, and would thus ``stick around'' forever. Package
10307 developers who found CVE alerts and verified they can be ignored can
10308 declare them as in this example:
10314 ;; These CVEs no longer apply and can be safely ignored.
10315 (properties `((lint-hidden-cve . ("CVE-2011-0433"
10318 "CVE-2011-5244")))))
10322 Warn about obvious source code formatting issues: trailing white space,
10323 use of tabulations, etc.
10326 The general syntax is:
10329 guix lint @var{options} @var{package}@dots{}
10332 If no package is given on the command line, then all packages are checked.
10333 The @var{options} may be zero or more of the following:
10336 @item --list-checkers
10338 List and describe all the available checkers that will be run on packages
10343 Only enable the checkers specified in a comma-separated list using the
10344 names returned by @option{--list-checkers}.
10346 @item --load-path=@var{directory}
10347 @itemx -L @var{directory}
10348 Add @var{directory} to the front of the package module search path
10349 (@pxref{Package Modules}).
10351 This allows users to define their own packages and make them visible to
10352 the command-line tools.
10356 @node Invoking guix size
10357 @section Invoking @command{guix size}
10360 @cindex package size
10362 @cindex @command{guix size}
10363 The @command{guix size} command helps package developers profile the
10364 disk usage of packages. It is easy to overlook the impact of an
10365 additional dependency added to a package, or the impact of using a
10366 single output for a package that could easily be split (@pxref{Packages
10367 with Multiple Outputs}). Such are the typical issues that
10368 @command{guix size} can highlight.
10370 The command can be passed one or more package specifications
10371 such as @code{gcc@@4.8}
10372 or @code{guile:debug}, or a file name in the store. Consider this
10376 $ guix size coreutils
10377 store item total self
10378 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
10379 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
10380 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
10381 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
10382 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
10383 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
10384 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
10385 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
10390 The store items listed here constitute the @dfn{transitive closure} of
10391 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
10392 would be returned by:
10395 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
10398 Here the output shows three columns next to store items. The first column,
10399 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
10400 the store item---that is, its own size plus the size of all its
10401 dependencies. The next column, labeled ``self'', shows the size of the
10402 item itself. The last column shows the ratio of the size of the item
10403 itself to the space occupied by all the items listed here.
10405 In this example, we see that the closure of Coreutils weighs in at
10406 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
10407 libraries. (That libc and GCC's libraries represent a large fraction of
10408 the closure is not a problem @i{per se} because they are always available
10409 on the system anyway.)
10411 Since the command also accepts store file names, assessing the size of
10412 a build result is straightforward:
10415 guix size $(guix system build config.scm)
10418 When the package(s) passed to @command{guix size} are available in the
10419 store@footnote{More precisely, @command{guix size} looks for the
10420 @emph{ungrafted} variant of the given package(s), as returned by
10421 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
10422 for information on grafts.}, @command{guix size} queries the daemon to determine its
10423 dependencies, and measures its size in the store, similar to @command{du
10424 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
10427 When the given packages are @emph{not} in the store, @command{guix size}
10428 reports information based on the available substitutes
10429 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
10430 store items that are not even on disk, only available remotely.
10432 You can also specify several package names:
10435 $ guix size coreutils grep sed bash
10436 store item total self
10437 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
10438 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
10439 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
10440 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
10446 In this example we see that the combination of the four packages takes
10447 102.3@tie{}MiB in total, which is much less than the sum of each closure
10448 since they have a lot of dependencies in common.
10450 When looking at the profile returned by @command{guix size}, you may
10451 find yourself wondering why a given package shows up in the profile at
10452 all. To understand it, you can use @command{guix graph --path -t
10453 references} to display the shortest path between the two packages
10454 (@pxref{Invoking guix graph}).
10456 The available options are:
10460 @item --substitute-urls=@var{urls}
10461 Use substitute information from @var{urls}.
10462 @xref{client-substitute-urls, the same option for @code{guix build}}.
10464 @item --sort=@var{key}
10465 Sort lines according to @var{key}, one of the following options:
10469 the size of each item (the default);
10471 the total size of the item's closure.
10474 @item --map-file=@var{file}
10475 Write a graphical map of disk usage in PNG format to @var{file}.
10477 For the example above, the map looks like this:
10479 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
10480 produced by @command{guix size}}
10482 This option requires that
10483 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
10484 installed and visible in Guile's module search path. When that is not
10485 the case, @command{guix size} fails as it tries to load it.
10487 @item --system=@var{system}
10488 @itemx -s @var{system}
10489 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
10491 @item --load-path=@var{directory}
10492 @itemx -L @var{directory}
10493 Add @var{directory} to the front of the package module search path
10494 (@pxref{Package Modules}).
10496 This allows users to define their own packages and make them visible to
10497 the command-line tools.
10500 @node Invoking guix graph
10501 @section Invoking @command{guix graph}
10504 @cindex @command{guix graph}
10505 @cindex package dependencies
10506 Packages and their dependencies form a @dfn{graph}, specifically a
10507 directed acyclic graph (DAG). It can quickly become difficult to have a
10508 mental model of the package DAG, so the @command{guix graph} command
10509 provides a visual representation of the DAG. By default,
10510 @command{guix graph} emits a DAG representation in the input format of
10511 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
10512 directly to the @command{dot} command of Graphviz. It can also emit an
10513 HTML page with embedded JavaScript code to display a ``chord diagram''
10514 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
10515 emit Cypher queries to construct a graph in a graph database supporting
10516 the @uref{https://www.opencypher.org/, openCypher} query language. With
10517 @option{--path}, it simply displays the shortest path between two
10518 packages. The general syntax is:
10521 guix graph @var{options} @var{package}@dots{}
10524 For example, the following command generates a PDF file representing the
10525 package DAG for the GNU@tie{}Core Utilities, showing its build-time
10529 guix graph coreutils | dot -Tpdf > dag.pdf
10532 The output looks like this:
10534 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
10536 Nice little graph, no?
10538 You may find it more pleasant to navigate the graph interactively with
10539 @command{xdot} (from the @code{xdot} package):
10542 guix graph coreutils | xdot -
10545 But there is more than one graph! The one above is concise: it is the
10546 graph of package objects, omitting implicit inputs such as GCC, libc,
10547 grep, etc. It is often useful to have such a concise graph, but
10548 sometimes one may want to see more details. @command{guix graph} supports
10549 several types of graphs, allowing you to choose the level of detail:
10553 This is the default type used in the example above. It shows the DAG of
10554 package objects, excluding implicit dependencies. It is concise, but
10555 filters out many details.
10557 @item reverse-package
10558 This shows the @emph{reverse} DAG of packages. For example:
10561 guix graph --type=reverse-package ocaml
10564 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
10565 you are also interested in cases where OCaml is an implicit dependency, see
10566 @code{reverse-bag} below).
10568 Note that for core packages this can yield huge graphs. If all you want
10569 is to know the number of packages that depend on a given package, use
10570 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
10571 @option{--list-dependent}}).
10574 This is the package DAG, @emph{including} implicit inputs.
10576 For instance, the following command:
10579 guix graph --type=bag-emerged coreutils
10582 ...@: yields this bigger graph:
10584 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
10586 At the bottom of the graph, we see all the implicit inputs of
10587 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
10589 Now, note that the dependencies of these implicit inputs---that is, the
10590 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
10591 here, for conciseness.
10594 Similar to @code{bag-emerged}, but this time including all the bootstrap
10597 @item bag-with-origins
10598 Similar to @code{bag}, but also showing origins and their dependencies.
10601 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
10602 it also takes implicit dependencies into account. For example:
10605 guix graph -t reverse-bag dune
10609 ...@: yields the graph of all packages that depend on Dune, directly or
10610 indirectly. Since Dune is an @emph{implicit} dependency of many packages
10611 @i{via} @code{dune-build-system}, this shows a large number of packages,
10612 whereas @code{reverse-package} would show very few if any.
10615 This is the most detailed representation: It shows the DAG of
10616 derivations (@pxref{Derivations}) and plain store items. Compared to
10617 the above representation, many additional nodes are visible, including
10618 build scripts, patches, Guile modules, etc.
10620 For this type of graph, it is also possible to pass a @file{.drv} file
10621 name instead of a package name, as in:
10624 guix graph -t derivation `guix system build -d my-config.scm`
10628 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
10629 For example, the following command shows the graph for the package
10630 module that defines the @code{guile} package:
10633 guix graph -t module guile | xdot -
10637 All the types above correspond to @emph{build-time dependencies}. The
10638 following graph type represents the @emph{run-time dependencies}:
10642 This is the graph of @dfn{references} of a package output, as returned
10643 by @command{guix gc --references} (@pxref{Invoking guix gc}).
10645 If the given package output is not available in the store, @command{guix
10646 graph} attempts to obtain dependency information from substitutes.
10648 Here you can also pass a store file name instead of a package name. For
10649 example, the command below produces the reference graph of your profile
10650 (which can be big!):
10653 guix graph -t references `readlink -f ~/.guix-profile`
10657 This is the graph of the @dfn{referrers} of a store item, as returned by
10658 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
10660 This relies exclusively on local information from your store. For
10661 instance, let us suppose that the current Inkscape is available in 10
10662 profiles on your machine; @command{guix graph -t referrers inkscape}
10663 will show a graph rooted at Inkscape and with those 10 profiles linked
10666 It can help determine what is preventing a store item from being garbage
10671 @cindex shortest path, between packages
10672 Often, the graph of the package you are interested in does not fit on
10673 your screen, and anyway all you want to know is @emph{why} that package
10674 actually depends on some seemingly unrelated package. The
10675 @option{--path} option instructs @command{guix graph} to display the
10676 shortest path between two packages (or derivations, or store items,
10680 $ guix graph --path emacs libunistring
10683 libunistring@@0.9.10
10684 $ guix graph --path -t derivation emacs libunistring
10685 /gnu/store/@dots{}-emacs-26.3.drv
10686 /gnu/store/@dots{}-mailutils-3.9.drv
10687 /gnu/store/@dots{}-libunistring-0.9.10.drv
10688 $ guix graph --path -t references emacs libunistring
10689 /gnu/store/@dots{}-emacs-26.3
10690 /gnu/store/@dots{}-libidn2-2.2.0
10691 /gnu/store/@dots{}-libunistring-0.9.10
10694 The available options are the following:
10697 @item --type=@var{type}
10698 @itemx -t @var{type}
10699 Produce a graph output of @var{type}, where @var{type} must be one of
10700 the values listed above.
10703 List the supported graph types.
10705 @item --backend=@var{backend}
10706 @itemx -b @var{backend}
10707 Produce a graph using the selected @var{backend}.
10709 @item --list-backends
10710 List the supported graph backends.
10712 Currently, the available backends are Graphviz and d3.js.
10715 Display the shortest path between two nodes of the type specified by
10716 @option{--type}. The example below shows the shortest path between
10717 @code{libreoffice} and @code{llvm} according to the references of
10718 @code{libreoffice}:
10721 $ guix graph --path -t references libreoffice llvm
10722 /gnu/store/@dots{}-libreoffice-6.4.2.2
10723 /gnu/store/@dots{}-libepoxy-1.5.4
10724 /gnu/store/@dots{}-mesa-19.3.4
10725 /gnu/store/@dots{}-llvm-9.0.1
10728 @item --expression=@var{expr}
10729 @itemx -e @var{expr}
10730 Consider the package @var{expr} evaluates to.
10732 This is useful to precisely refer to a package, as in this example:
10735 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
10738 @item --system=@var{system}
10739 @itemx -s @var{system}
10740 Display the graph for @var{system}---e.g., @code{i686-linux}.
10742 The package dependency graph is largely architecture-independent, but there
10743 are some architecture-dependent bits that this option allows you to visualize.
10745 @item --load-path=@var{directory}
10746 @itemx -L @var{directory}
10747 Add @var{directory} to the front of the package module search path
10748 (@pxref{Package Modules}).
10750 This allows users to define their own packages and make them visible to
10751 the command-line tools.
10754 On top of that, @command{guix graph} supports all the usual package
10755 transformation options (@pxref{Package Transformation Options}). This
10756 makes it easy to view the effect of a graph-rewriting transformation
10757 such as @option{--with-input}. For example, the command below outputs
10758 the graph of @code{git} once @code{openssl} has been replaced by
10759 @code{libressl} everywhere in the graph:
10762 guix graph git --with-input=openssl=libressl
10765 So many possibilities, so much fun!
10767 @node Invoking guix publish
10768 @section Invoking @command{guix publish}
10770 @cindex @command{guix publish}
10771 The purpose of @command{guix publish} is to enable users to easily share
10772 their store with others, who can then use it as a substitute server
10773 (@pxref{Substitutes}).
10775 When @command{guix publish} runs, it spawns an HTTP server which allows
10776 anyone with network access to obtain substitutes from it. This means
10777 that any machine running Guix can also act as if it were a build farm,
10778 since the HTTP interface is compatible with Cuirass, the software behind
10779 the @code{@value{SUBSTITUTE-SERVER}} build farm.
10781 For security, each substitute is signed, allowing recipients to check
10782 their authenticity and integrity (@pxref{Substitutes}). Because
10783 @command{guix publish} uses the signing key of the system, which is only
10784 readable by the system administrator, it must be started as root; the
10785 @option{--user} option makes it drop root privileges early on.
10787 The signing key pair must be generated before @command{guix publish} is
10788 launched, using @command{guix archive --generate-key} (@pxref{Invoking
10791 The general syntax is:
10794 guix publish @var{options}@dots{}
10797 Running @command{guix publish} without any additional arguments will
10798 spawn an HTTP server on port 8080:
10804 Once a publishing server has been authorized (@pxref{Invoking guix
10805 archive}), the daemon may download substitutes from it:
10808 guix-daemon --substitute-urls=http://example.org:8080
10811 By default, @command{guix publish} compresses archives on the fly as it
10812 serves them. This ``on-the-fly'' mode is convenient in that it requires
10813 no setup and is immediately available. However, when serving lots of
10814 clients, we recommend using the @option{--cache} option, which enables
10815 caching of the archives before they are sent to clients---see below for
10816 details. The @command{guix weather} command provides a handy way to
10817 check what a server provides (@pxref{Invoking guix weather}).
10819 As a bonus, @command{guix publish} also serves as a content-addressed
10820 mirror for source files referenced in @code{origin} records
10821 (@pxref{origin Reference}). For instance, assuming @command{guix
10822 publish} is running on @code{example.org}, the following URL returns the
10823 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
10824 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
10827 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
10830 Obviously, these URLs only work for files that are in the store; in
10831 other cases, they return 404 (``Not Found'').
10833 @cindex build logs, publication
10834 Build logs are available from @code{/log} URLs like:
10837 http://example.org/log/gwspk@dots{}-guile-2.2.3
10841 When @command{guix-daemon} is configured to save compressed build logs,
10842 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
10843 URLs return the compressed log as-is, with an appropriate
10844 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
10845 running @command{guix-daemon} with @option{--log-compression=gzip} since
10846 Web browsers can automatically decompress it, which is not the case with
10849 The following options are available:
10852 @item --port=@var{port}
10853 @itemx -p @var{port}
10854 Listen for HTTP requests on @var{port}.
10856 @item --listen=@var{host}
10857 Listen on the network interface for @var{host}. The default is to
10858 accept connections from any interface.
10860 @item --user=@var{user}
10861 @itemx -u @var{user}
10862 Change privileges to @var{user} as soon as possible---i.e., once the
10863 server socket is open and the signing key has been read.
10865 @item --compression[=@var{method}[:@var{level}]]
10866 @itemx -C [@var{method}[:@var{level}]]
10867 Compress data using the given @var{method} and @var{level}. @var{method} is
10868 one of @code{lzip} and @code{gzip}; when @var{method} is omitted, @code{gzip}
10871 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
10872 to different compression levels: 1 is the fastest, and 9 is the best
10873 (CPU-intensive). The default is 3.
10875 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a small
10876 increase in CPU usage; see
10877 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip Web
10880 Unless @option{--cache} is used, compression occurs on the fly and
10881 the compressed streams are not
10882 cached. Thus, to reduce load on the machine that runs @command{guix
10883 publish}, it may be a good idea to choose a low compression level, to
10884 run @command{guix publish} behind a caching proxy, or to use
10885 @option{--cache}. Using @option{--cache} has the advantage that it
10886 allows @command{guix publish} to add @code{Content-Length} HTTP header
10889 This option can be repeated, in which case every substitute gets compressed
10890 using all the selected methods, and all of them are advertised. This is
10891 useful when users may not support all the compression methods: they can select
10892 the one they support.
10894 @item --cache=@var{directory}
10895 @itemx -c @var{directory}
10896 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
10897 and only serve archives that are in cache.
10899 When this option is omitted, archives and meta-data are created
10900 on-the-fly. This can reduce the available bandwidth, especially when
10901 compression is enabled, since this may become CPU-bound. Another
10902 drawback of the default mode is that the length of archives is not known
10903 in advance, so @command{guix publish} does not add a
10904 @code{Content-Length} HTTP header to its responses, which in turn
10905 prevents clients from knowing the amount of data being downloaded.
10907 Conversely, when @option{--cache} is used, the first request for a store
10908 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
10909 background process to @dfn{bake} the archive---computing its
10910 @code{.narinfo} and compressing the archive, if needed. Once the
10911 archive is cached in @var{directory}, subsequent requests succeed and
10912 are served directly from the cache, which guarantees that clients get
10913 the best possible bandwidth.
10915 The ``baking'' process is performed by worker threads. By default, one
10916 thread per CPU core is created, but this can be customized. See
10917 @option{--workers} below.
10919 When @option{--ttl} is used, cached entries are automatically deleted
10920 when they have expired.
10922 @item --workers=@var{N}
10923 When @option{--cache} is used, request the allocation of @var{N} worker
10924 threads to ``bake'' archives.
10926 @item --ttl=@var{ttl}
10927 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
10928 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
10929 days, @code{1m} means 1 month, and so on.
10931 This allows the user's Guix to keep substitute information in cache for
10932 @var{ttl}. However, note that @code{guix publish} does not itself
10933 guarantee that the store items it provides will indeed remain available
10934 for as long as @var{ttl}.
10936 Additionally, when @option{--cache} is used, cached entries that have
10937 not been accessed for @var{ttl} and that no longer have a corresponding
10938 item in the store, may be deleted.
10940 @item --nar-path=@var{path}
10941 Use @var{path} as the prefix for the URLs of ``nar'' files
10942 (@pxref{Invoking guix archive, normalized archives}).
10944 By default, nars are served at a URL such as
10945 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
10946 change the @code{/nar} part to @var{path}.
10948 @item --public-key=@var{file}
10949 @itemx --private-key=@var{file}
10950 Use the specific @var{file}s as the public/private key pair used to sign
10951 the store items being published.
10953 The files must correspond to the same key pair (the private key is used
10954 for signing and the public key is merely advertised in the signature
10955 metadata). They must contain keys in the canonical s-expression format
10956 as produced by @command{guix archive --generate-key} (@pxref{Invoking
10957 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
10958 @file{/etc/guix/signing-key.sec} are used.
10960 @item --repl[=@var{port}]
10961 @itemx -r [@var{port}]
10962 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
10963 Reference Manual}) on @var{port} (37146 by default). This is used
10964 primarily for debugging a running @command{guix publish} server.
10967 Enabling @command{guix publish} on Guix System is a one-liner: just
10968 instantiate a @code{guix-publish-service-type} service in the @code{services} field
10969 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
10970 @code{guix-publish-service-type}}).
10972 If you are instead running Guix on a ``foreign distro'', follow these
10977 If your host distro uses the systemd init system:
10980 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
10981 /etc/systemd/system/
10982 # systemctl start guix-publish && systemctl enable guix-publish
10986 If your host distro uses the Upstart init system:
10989 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
10990 # start guix-publish
10994 Otherwise, proceed similarly with your distro's init system.
10997 @node Invoking guix challenge
10998 @section Invoking @command{guix challenge}
11000 @cindex reproducible builds
11001 @cindex verifiable builds
11002 @cindex @command{guix challenge}
11004 Do the binaries provided by this server really correspond to the source
11005 code it claims to build? Is a package build process deterministic?
11006 These are the questions the @command{guix challenge} command attempts to
11009 The former is obviously an important question: Before using a substitute
11010 server (@pxref{Substitutes}), one had better @emph{verify} that it
11011 provides the right binaries, and thus @emph{challenge} it. The latter
11012 is what enables the former: If package builds are deterministic, then
11013 independent builds of the package should yield the exact same result,
11014 bit for bit; if a server provides a binary different from the one
11015 obtained locally, it may be either corrupt or malicious.
11017 We know that the hash that shows up in @file{/gnu/store} file names is
11018 the hash of all the inputs of the process that built the file or
11019 directory---compilers, libraries, build scripts,
11020 etc. (@pxref{Introduction}). Assuming deterministic build processes,
11021 one store file name should map to exactly one build output.
11022 @command{guix challenge} checks whether there is, indeed, a single
11023 mapping by comparing the build outputs of several independent builds of
11024 any given store item.
11026 The command output looks like this:
11029 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
11030 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
11031 updating list of substitutes from 'https://guix.example.org'... 100.0%
11032 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
11033 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
11034 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
11035 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
11037 /lib/libcrypto.so.1.1
11040 /gnu/store/@dots{}-git-2.5.0 contents differ:
11041 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
11042 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
11043 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
11045 /libexec/git-core/git-fsck
11047 /gnu/store/@dots{}-pius-2.1.1 contents differ:
11048 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
11049 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
11050 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
11052 /share/man/man1/pius.1.gz
11056 6,406 store items were analyzed:
11057 - 4,749 (74.1%) were identical
11058 - 525 (8.2%) differed
11059 - 1,132 (17.7%) were inconclusive
11063 In this example, @command{guix challenge} first scans the store to
11064 determine the set of locally-built derivations---as opposed to store
11065 items that were downloaded from a substitute server---and then queries
11066 all the substitute servers. It then reports those store items for which
11067 the servers obtained a result different from the local build.
11069 @cindex non-determinism, in package builds
11070 As an example, @code{guix.example.org} always gets a different answer.
11071 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
11072 case of Git. This might indicate that the build process of Git is
11073 non-deterministic, meaning that its output varies as a function of
11074 various things that Guix does not fully control, in spite of building
11075 packages in isolated environments (@pxref{Features}). Most common
11076 sources of non-determinism include the addition of timestamps in build
11077 results, the inclusion of random numbers, and directory listings sorted
11078 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
11081 To find out what is wrong with this Git binary, the easiest approach is
11085 guix challenge git \
11086 --diff=diffoscope \
11087 --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
11090 This automatically invokes @command{diffoscope}, which displays detailed
11091 information about files that differ.
11093 Alternatively, we can do something along these lines (@pxref{Invoking guix
11097 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-git-2.5.0 \
11098 | lzip -d | guix archive -x /tmp/git
11099 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
11102 This command shows the difference between the files resulting from the
11103 local build, and the files resulting from the build on
11104 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
11105 diffutils, Comparing and Merging Files}). The @command{diff} command
11106 works great for text files. When binary files differ, a better option
11107 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
11108 visualize differences for all kinds of files.
11110 Once you have done that work, you can tell whether the differences are due
11111 to a non-deterministic build process or to a malicious server. We try
11112 hard to remove sources of non-determinism in packages to make it easier
11113 to verify substitutes, but of course, this is a process that
11114 involves not just Guix, but a large part of the free software community.
11115 In the meantime, @command{guix challenge} is one tool to help address
11118 If you are writing packages for Guix, you are encouraged to check
11119 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
11120 same build result as you did with:
11123 $ guix challenge @var{package}
11127 where @var{package} is a package specification such as
11128 @code{guile@@2.0} or @code{glibc:debug}.
11130 The general syntax is:
11133 guix challenge @var{options} [@var{packages}@dots{}]
11136 When a difference is found between the hash of a locally-built item and
11137 that of a server-provided substitute, or among substitutes provided by
11138 different servers, the command displays it as in the example above and
11139 its exit code is 2 (other non-zero exit codes denote other kinds of
11142 The one option that matters is:
11146 @item --substitute-urls=@var{urls}
11147 Consider @var{urls} the whitespace-separated list of substitute source
11148 URLs to compare to.
11150 @item --diff=@var{mode}
11151 Upon mismatches, show differences according to @var{mode}, one of:
11154 @item @code{simple} (the default)
11155 Show the list of files that differ.
11157 @item @code{diffoscope}
11158 @itemx @var{command}
11159 Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
11160 two directories whose contents do not match.
11162 When @var{command} is an absolute file name, run @var{command} instead
11166 Do not show further details about the differences.
11169 Thus, unless @option{--diff=none} is passed, @command{guix challenge}
11170 downloads the store items from the given substitute servers so that it
11175 Show details about matches (identical contents) in addition to
11176 information about mismatches.
11180 @node Invoking guix copy
11181 @section Invoking @command{guix copy}
11183 @cindex copy, of store items, over SSH
11184 @cindex SSH, copy of store items
11185 @cindex sharing store items across machines
11186 @cindex transferring store items across machines
11187 The @command{guix copy} command copies items from the store of one
11188 machine to that of another machine over a secure shell (SSH)
11189 connection@footnote{This command is available only when Guile-SSH was
11190 found. @xref{Requirements}, for details.}. For example, the following
11191 command copies the @code{coreutils} package, the user's profile, and all
11192 their dependencies over to @var{host}, logged in as @var{user}:
11195 guix copy --to=@var{user}@@@var{host} \
11196 coreutils `readlink -f ~/.guix-profile`
11199 If some of the items to be copied are already present on @var{host},
11200 they are not actually sent.
11202 The command below retrieves @code{libreoffice} and @code{gimp} from
11203 @var{host}, assuming they are available there:
11206 guix copy --from=@var{host} libreoffice gimp
11209 The SSH connection is established using the Guile-SSH client, which is
11210 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
11211 @file{~/.ssh/config}, and uses the SSH agent for authentication.
11213 The key used to sign items that are sent must be accepted by the remote
11214 machine. Likewise, the key used by the remote machine to sign items you
11215 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
11216 own daemon. @xref{Invoking guix archive}, for more information about
11217 store item authentication.
11219 The general syntax is:
11222 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
11225 You must always specify one of the following options:
11228 @item --to=@var{spec}
11229 @itemx --from=@var{spec}
11230 Specify the host to send to or receive from. @var{spec} must be an SSH
11231 spec such as @code{example.org}, @code{charlie@@example.org}, or
11232 @code{charlie@@example.org:2222}.
11235 The @var{items} can be either package names, such as @code{gimp}, or
11236 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
11238 When specifying the name of a package to send, it is first built if
11239 needed, unless @option{--dry-run} was specified. Common build options
11240 are supported (@pxref{Common Build Options}).
11243 @node Invoking guix container
11244 @section Invoking @command{guix container}
11246 @cindex @command{guix container}
11248 As of version @value{VERSION}, this tool is experimental. The interface
11249 is subject to radical change in the future.
11252 The purpose of @command{guix container} is to manipulate processes
11253 running within an isolated environment, commonly known as a
11254 ``container'', typically created by the @command{guix environment}
11255 (@pxref{Invoking guix environment}) and @command{guix system container}
11256 (@pxref{Invoking guix system}) commands.
11258 The general syntax is:
11261 guix container @var{action} @var{options}@dots{}
11264 @var{action} specifies the operation to perform with a container, and
11265 @var{options} specifies the context-specific arguments for the action.
11267 The following actions are available:
11271 Execute a command within the context of a running container.
11276 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
11279 @var{pid} specifies the process ID of the running container.
11280 @var{program} specifies an executable file name within the root file
11281 system of the container. @var{arguments} are the additional options that
11282 will be passed to @var{program}.
11284 The following command launches an interactive login shell inside a
11285 Guix system container, started by @command{guix system container}, and whose
11286 process ID is 9001:
11289 guix container exec 9001 /run/current-system/profile/bin/bash --login
11292 Note that the @var{pid} cannot be the parent process of a container. It
11293 must be PID 1 of the container or one of its child processes.
11297 @node Invoking guix weather
11298 @section Invoking @command{guix weather}
11300 Occasionally you're grumpy because substitutes are lacking and you end
11301 up building packages by yourself (@pxref{Substitutes}). The
11302 @command{guix weather} command reports on substitute availability on the
11303 specified servers so you can have an idea of whether you'll be grumpy
11304 today. It can sometimes be useful info as a user, but it is primarily
11305 useful to people running @command{guix publish} (@pxref{Invoking guix
11308 @cindex statistics, for substitutes
11309 @cindex availability of substitutes
11310 @cindex substitute availability
11311 @cindex weather, substitute availability
11312 Here's a sample run:
11315 $ guix weather --substitute-urls=https://guix.example.org
11316 computing 5,872 package derivations for x86_64-linux...
11317 looking for 6,128 store items on https://guix.example.org..
11318 updating list of substitutes from 'https://guix.example.org'... 100.0%
11319 https://guix.example.org
11320 43.4% substitutes available (2,658 out of 6,128)
11321 7,032.5 MiB of nars (compressed)
11322 19,824.2 MiB on disk (uncompressed)
11323 0.030 seconds per request (182.9 seconds in total)
11324 33.5 requests per second
11326 9.8% (342 out of 3,470) of the missing items are queued
11328 x86_64-linux: 518 (59.7%)
11329 i686-linux: 221 (25.5%)
11330 aarch64-linux: 128 (14.8%)
11331 build rate: 23.41 builds per hour
11332 x86_64-linux: 11.16 builds per hour
11333 i686-linux: 6.03 builds per hour
11334 aarch64-linux: 6.41 builds per hour
11337 @cindex continuous integration, statistics
11338 As you can see, it reports the fraction of all the packages for which
11339 substitutes are available on the server---regardless of whether
11340 substitutes are enabled, and regardless of whether this server's signing
11341 key is authorized. It also reports the size of the compressed archives
11342 (``nars'') provided by the server, the size the corresponding store
11343 items occupy in the store (assuming deduplication is turned off), and
11344 the server's throughput. The second part gives continuous integration
11345 (CI) statistics, if the server supports it. In addition, using the
11346 @option{--coverage} option, @command{guix weather} can list ``important''
11347 package substitutes missing on the server (see below).
11349 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
11350 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
11351 challenge}, it ignores signatures on those substitutes, which is
11352 innocuous since the command only gathers statistics and cannot install
11355 The general syntax is:
11358 guix weather @var{options}@dots{} [@var{packages}@dots{}]
11361 When @var{packages} is omitted, @command{guix weather} checks the availability
11362 of substitutes for @emph{all} the packages, or for those specified with
11363 @option{--manifest}; otherwise it only considers the specified packages. It
11364 is also possible to query specific system types with @option{--system}.
11365 @command{guix weather} exits with a non-zero code when the fraction of
11366 available substitutes is below 100%.
11368 The available options are listed below.
11371 @item --substitute-urls=@var{urls}
11372 @var{urls} is the space-separated list of substitute server URLs to
11373 query. When this option is omitted, the default set of substitute
11374 servers is queried.
11376 @item --system=@var{system}
11377 @itemx -s @var{system}
11378 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
11379 option can be repeated, in which case @command{guix weather} will query
11380 substitutes for several system types.
11382 @item --manifest=@var{file}
11383 Instead of querying substitutes for all the packages, only ask for those
11384 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
11385 with the @code{-m} option of @command{guix package} (@pxref{Invoking
11388 This option can be repeated several times, in which case the manifests
11391 @item --coverage[=@var{count}]
11392 @itemx -c [@var{count}]
11393 Report on substitute coverage for packages: list packages with at least
11394 @var{count} dependents (zero by default) for which substitutes are
11395 unavailable. Dependent packages themselves are not listed: if @var{b} depends
11396 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
11397 @var{b} usually lacks substitutes as well. The result looks like this:
11400 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
11401 computing 8,983 package derivations for x86_64-linux...
11402 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
11403 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
11404 @value{SUBSTITUTE-URL}
11405 64.7% substitutes available (6,047 out of 9,343)
11407 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
11408 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
11409 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
11410 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
11414 What this example shows is that @code{kcoreaddons} and presumably the 58
11415 packages that depend on it have no substitutes at @code{ci.guix.info};
11416 likewise for @code{qgpgme} and the 46 packages that depend on it.
11418 If you are a Guix developer, or if you are taking care of this build farm,
11419 you'll probably want to have a closer look at these packages: they may simply
11422 @item --display-missing
11423 Display the list of store items for which substitutes are missing.
11426 @node Invoking guix processes
11427 @section Invoking @command{guix processes}
11429 The @command{guix processes} command can be useful to developers and system
11430 administrators, especially on multi-user machines and on build farms: it lists
11431 the current sessions (connections to the daemon), as well as information about
11432 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
11433 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
11434 listed.}. Here's an example of the information it returns:
11437 $ sudo guix processes
11440 ClientCommand: guix environment --ad-hoc python
11444 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
11448 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
11449 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
11450 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
11451 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
11452 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
11453 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
11454 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
11457 In this example we see that @command{guix-daemon} has three clients:
11458 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
11459 integration tool; their process identifier (PID) is given by the
11460 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
11461 @command{guix-daemon} sub-process of this particular session.
11463 The @code{LockHeld} fields show which store items are currently locked by this
11464 session, which corresponds to store items being built or substituted (the
11465 @code{LockHeld} field is not displayed when @command{guix processes} is not
11466 running as root). Last, by looking at the @code{ChildProcess} field, we
11467 understand that these three builds are being offloaded (@pxref{Daemon Offload
11470 The output is in Recutils format so we can use the handy @command{recsel}
11471 command to select sessions of interest (@pxref{Selection Expressions,,,
11472 recutils, GNU recutils manual}). As an example, the command shows the command
11473 line and PID of the client that triggered the build of a Perl package:
11476 $ sudo guix processes | \
11477 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
11479 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
11482 @node System Configuration
11483 @chapter System Configuration
11485 @cindex system configuration
11486 Guix System supports a consistent whole-system configuration
11487 mechanism. By that we mean that all aspects of the global system
11488 configuration---such as the available system services, timezone and
11489 locale settings, user accounts---are declared in a single place. Such
11490 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
11492 One of the advantages of putting all the system configuration under the
11493 control of Guix is that it supports transactional system upgrades, and
11494 makes it possible to roll back to a previous system instantiation,
11495 should something go wrong with the new one (@pxref{Features}). Another
11496 advantage is that it makes it easy to replicate the exact same configuration
11497 across different machines, or at different points in time, without
11498 having to resort to additional administration tools layered on top of
11499 the own tools of the system.
11500 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
11502 This section describes this mechanism. First we focus on the system
11503 administrator's viewpoint---explaining how the system is configured and
11504 instantiated. Then we show how this mechanism can be extended, for
11505 instance to support new system services.
11508 * Using the Configuration System:: Customizing your GNU system.
11509 * operating-system Reference:: Detail of operating-system declarations.
11510 * File Systems:: Configuring file system mounts.
11511 * Mapped Devices:: Block device extra processing.
11512 * User Accounts:: Specifying user accounts.
11513 * Keyboard Layout:: How the system interprets key strokes.
11514 * Locales:: Language and cultural convention settings.
11515 * Services:: Specifying system services.
11516 * Setuid Programs:: Programs running with root privileges.
11517 * X.509 Certificates:: Authenticating HTTPS servers.
11518 * Name Service Switch:: Configuring libc's name service switch.
11519 * Initial RAM Disk:: Linux-Libre bootstrapping.
11520 * Bootloader Configuration:: Configuring the boot loader.
11521 * Invoking guix system:: Instantiating a system configuration.
11522 * Invoking guix deploy:: Deploying a system configuration to a remote host.
11523 * Running Guix in a VM:: How to run Guix System in a virtual machine.
11524 * Defining Services:: Adding new service definitions.
11527 @node Using the Configuration System
11528 @section Using the Configuration System
11530 The operating system is configured by providing an
11531 @code{operating-system} declaration in a file that can then be passed to
11532 the @command{guix system} command (@pxref{Invoking guix system}). A
11533 simple setup, with the default system services, the default Linux-Libre
11534 kernel, initial RAM disk, and boot loader looks like this:
11536 @findex operating-system
11538 @include os-config-bare-bones.texi
11541 This example should be self-describing. Some of the fields defined
11542 above, such as @code{host-name} and @code{bootloader}, are mandatory.
11543 Others, such as @code{packages} and @code{services}, can be omitted, in
11544 which case they get a default value.
11546 Below we discuss the effect of some of the most important fields
11547 (@pxref{operating-system Reference}, for details about all the available
11548 fields), and how to @dfn{instantiate} the operating system using
11549 @command{guix system}.
11551 @unnumberedsubsec Bootloader
11553 @cindex legacy boot, on Intel machines
11554 @cindex BIOS boot, on Intel machines
11557 The @code{bootloader} field describes the method that will be used to boot
11558 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
11559 mode, as in the example above. However, more recent machines rely instead on
11560 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
11561 the @code{bootloader} field should contain something along these lines:
11564 (bootloader-configuration
11565 (bootloader grub-efi-bootloader)
11566 (target "/boot/efi"))
11569 @xref{Bootloader Configuration}, for more information on the available
11570 configuration options.
11572 @unnumberedsubsec Globally-Visible Packages
11574 @vindex %base-packages
11575 The @code{packages} field lists packages that will be globally visible
11576 on the system, for all user accounts---i.e., in every user's @env{PATH}
11577 environment variable---in addition to the per-user profiles
11578 (@pxref{Invoking guix package}). The @code{%base-packages} variable
11579 provides all the tools one would expect for basic user and administrator
11580 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
11581 the GNU Zile lightweight text editor, @command{find}, @command{grep},
11582 etc. The example above adds GNU@tie{}Screen to those,
11583 taken from the @code{(gnu packages screen)}
11584 module (@pxref{Package Modules}). The
11585 @code{(list package output)} syntax can be used to add a specific output
11589 (use-modules (gnu packages))
11590 (use-modules (gnu packages dns))
11594 (packages (cons (list bind "utils")
11598 @findex specification->package
11599 Referring to packages by variable name, like @code{bind} above, has
11600 the advantage of being unambiguous; it also allows typos and such to be
11601 diagnosed right away as ``unbound variables''. The downside is that one
11602 needs to know which module defines which package, and to augment the
11603 @code{use-package-modules} line accordingly. To avoid that, one can use
11604 the @code{specification->package} procedure of the @code{(gnu packages)}
11605 module, which returns the best package for a given name or name and
11609 (use-modules (gnu packages))
11613 (packages (append (map specification->package
11614 '("tcpdump" "htop" "gnupg@@2.0"))
11618 @unnumberedsubsec System Services
11621 @vindex %base-services
11622 The @code{services} field lists @dfn{system services} to be made
11623 available when the system starts (@pxref{Services}).
11624 The @code{operating-system} declaration above specifies that, in
11625 addition to the basic services, we want the OpenSSH secure shell
11626 daemon listening on port 2222 (@pxref{Networking Services,
11627 @code{openssh-service-type}}). Under the hood,
11628 @code{openssh-service-type} arranges so that @command{sshd} is started with the
11629 right command-line options, possibly with supporting configuration files
11630 generated as needed (@pxref{Defining Services}).
11632 @cindex customization, of services
11633 @findex modify-services
11634 Occasionally, instead of using the base services as is, you will want to
11635 customize them. To do this, use @code{modify-services} (@pxref{Service
11636 Reference, @code{modify-services}}) to modify the list.
11638 For example, suppose you want to modify @code{guix-daemon} and Mingetty
11639 (the console log-in) in the @code{%base-services} list (@pxref{Base
11640 Services, @code{%base-services}}). To do that, you can write the
11641 following in your operating system declaration:
11644 (define %my-services
11645 ;; My very own list of services.
11646 (modify-services %base-services
11647 (guix-service-type config =>
11648 (guix-configuration
11650 (use-substitutes? #f)
11651 (extra-options '("--gc-keep-derivations"))))
11652 (mingetty-service-type config =>
11653 (mingetty-configuration
11654 (inherit config)))))
11658 (services %my-services))
11661 This changes the configuration---i.e., the service parameters---of the
11662 @code{guix-service-type} instance, and that of all the
11663 @code{mingetty-service-type} instances in the @code{%base-services} list.
11664 Observe how this is accomplished: first, we arrange for the original
11665 configuration to be bound to the identifier @code{config} in the
11666 @var{body}, and then we write the @var{body} so that it evaluates to the
11667 desired configuration. In particular, notice how we use @code{inherit}
11668 to create a new configuration which has the same values as the old
11669 configuration, but with a few modifications.
11671 @cindex encrypted disk
11672 The configuration for a typical ``desktop'' usage, with an encrypted
11673 root partition, the X11 display
11674 server, GNOME and Xfce (users can choose which of these desktop
11675 environments to use at the log-in screen by pressing @kbd{F1}), network
11676 management, power management, and more, would look like this:
11679 @include os-config-desktop.texi
11682 A graphical system with a choice of lightweight window managers
11683 instead of full-blown desktop environments would look like this:
11686 @include os-config-lightweight-desktop.texi
11689 This example refers to the @file{/boot/efi} file system by its UUID,
11690 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
11691 as returned by the @command{blkid} command.
11693 @xref{Desktop Services}, for the exact list of services provided by
11694 @code{%desktop-services}. @xref{X.509 Certificates}, for background
11695 information about the @code{nss-certs} package that is used here.
11697 Again, @code{%desktop-services} is just a list of service objects. If
11698 you want to remove services from there, you can do so using the
11699 procedures for list filtering (@pxref{SRFI-1 Filtering and
11700 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
11701 following expression returns a list that contains all the services in
11702 @code{%desktop-services} minus the Avahi service:
11705 (remove (lambda (service)
11706 (eq? (service-kind service) avahi-service-type))
11710 @unnumberedsubsec Instantiating the System
11712 Assuming the @code{operating-system} declaration
11713 is stored in the @file{my-system-config.scm}
11714 file, the @command{guix system reconfigure my-system-config.scm} command
11715 instantiates that configuration, and makes it the default GRUB boot
11716 entry (@pxref{Invoking guix system}).
11718 The normal way to change the system configuration is by updating this
11719 file and re-running @command{guix system reconfigure}. One should never
11720 have to touch files in @file{/etc} or to run commands that modify the
11721 system state such as @command{useradd} or @command{grub-install}. In
11722 fact, you must avoid that since that would not only void your warranty
11723 but also prevent you from rolling back to previous versions of your
11724 system, should you ever need to.
11726 @cindex roll-back, of the operating system
11727 Speaking of roll-back, each time you run @command{guix system
11728 reconfigure}, a new @dfn{generation} of the system is created---without
11729 modifying or deleting previous generations. Old system generations get
11730 an entry in the bootloader boot menu, allowing you to boot them in case
11731 something went wrong with the latest generation. Reassuring, no? The
11732 @command{guix system list-generations} command lists the system
11733 generations available on disk. It is also possible to roll back the
11734 system via the commands @command{guix system roll-back} and
11735 @command{guix system switch-generation}.
11737 Although the @command{guix system reconfigure} command will not modify
11738 previous generations, you must take care when the current generation is not
11739 the latest (e.g., after invoking @command{guix system roll-back}), since
11740 the operation might overwrite a later generation (@pxref{Invoking guix
11743 @unnumberedsubsec The Programming Interface
11745 At the Scheme level, the bulk of an @code{operating-system} declaration
11746 is instantiated with the following monadic procedure (@pxref{The Store
11749 @deffn {Monadic Procedure} operating-system-derivation os
11750 Return a derivation that builds @var{os}, an @code{operating-system}
11751 object (@pxref{Derivations}).
11753 The output of the derivation is a single directory that refers to all
11754 the packages, configuration files, and other supporting files needed to
11755 instantiate @var{os}.
11758 This procedure is provided by the @code{(gnu system)} module. Along
11759 with @code{(gnu services)} (@pxref{Services}), this module contains the
11760 guts of Guix System. Make sure to visit it!
11763 @node operating-system Reference
11764 @section @code{operating-system} Reference
11766 This section summarizes all the options available in
11767 @code{operating-system} declarations (@pxref{Using the Configuration
11770 @deftp {Data Type} operating-system
11771 This is the data type representing an operating system configuration.
11772 By that, we mean all the global system configuration, not per-user
11773 configuration (@pxref{Using the Configuration System}).
11776 @item @code{kernel} (default: @code{linux-libre})
11777 The package object of the operating system kernel to
11778 use@footnote{Currently only the Linux-libre kernel is fully supported.
11779 Using GNU@tie{}mach with the GNU@tie{}Hurd is experimental and only
11780 available when building a virtual machine disk image.}.
11783 @item @code{hurd} (default: @code{#f})
11784 The package object of the hurd to be started by the kernel. When this
11785 field is set, produce a GNU/Hurd operating system. In that case,
11786 @code{kernel} must also be set to the @code{gnumach} package---the
11787 microkernel the Hurd runs on.
11790 This feature is experimental and only supported for disk images.
11793 @item @code{kernel-loadable-modules} (default: '())
11794 A list of objects (usually packages) to collect loadable kernel modules
11795 from--e.g. @code{(list ddcci-driver-linux)}.
11797 @item @code{kernel-arguments} (default: @code{%default-kernel-arguments})
11798 List of strings or gexps representing additional arguments to pass on
11799 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
11801 @item @code{bootloader}
11802 The system bootloader configuration object. @xref{Bootloader Configuration}.
11805 This is the label (a string) as it appears in the bootloader's menu entry.
11806 The default label includes the kernel name and version.
11808 @item @code{keyboard-layout} (default: @code{#f})
11809 This field specifies the keyboard layout to use in the console. It can be
11810 either @code{#f}, in which case the default keyboard layout is used (usually
11811 US English), or a @code{<keyboard-layout>} record.
11813 This keyboard layout is in effect as soon as the kernel has booted. For
11814 instance, it is the keyboard layout in effect when you type a passphrase if
11815 your root file system is on a @code{luks-device-mapping} mapped device
11816 (@pxref{Mapped Devices}).
11819 This does @emph{not} specify the keyboard layout used by the bootloader, nor
11820 that used by the graphical display server. @xref{Bootloader Configuration},
11821 for information on how to specify the bootloader's keyboard layout. @xref{X
11822 Window}, for information on how to specify the keyboard layout used by the X
11826 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
11828 @cindex initial RAM disk
11829 The list of Linux kernel modules that need to be available in the
11830 initial RAM disk. @xref{Initial RAM Disk}.
11832 @item @code{initrd} (default: @code{base-initrd})
11833 A procedure that returns an initial RAM disk for the Linux
11834 kernel. This field is provided to support low-level customization and
11835 should rarely be needed for casual use. @xref{Initial RAM Disk}.
11837 @item @code{firmware} (default: @code{%base-firmware})
11839 List of firmware packages loadable by the operating system kernel.
11841 The default includes firmware needed for Atheros- and Broadcom-based
11842 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
11843 respectively). @xref{Hardware Considerations}, for more info on
11844 supported hardware.
11846 @item @code{host-name}
11849 @item @code{hosts-file}
11851 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
11852 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
11853 Reference Manual}). The default is a file with entries for
11854 @code{localhost} and @var{host-name}.
11856 @item @code{mapped-devices} (default: @code{'()})
11857 A list of mapped devices. @xref{Mapped Devices}.
11859 @item @code{file-systems}
11860 A list of file systems. @xref{File Systems}.
11862 @item @code{swap-devices} (default: @code{'()})
11863 @cindex swap devices
11864 A list of strings identifying devices or files to be used for ``swap
11865 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
11866 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
11867 It is possible to specify a swap file in a file system on a mapped
11868 device, provided that the necessary device mapping and file system are
11869 also specified. @xref{Mapped Devices} and @ref{File Systems}.
11871 @item @code{users} (default: @code{%base-user-accounts})
11872 @itemx @code{groups} (default: @code{%base-groups})
11873 List of user accounts and groups. @xref{User Accounts}.
11875 If the @code{users} list lacks a user account with UID@tie{}0, a
11876 ``root'' account with UID@tie{}0 is automatically added.
11878 @item @code{skeletons} (default: @code{(default-skeletons)})
11879 A list target file name/file-like object tuples (@pxref{G-Expressions,
11880 file-like objects}). These are the skeleton files that will be added to
11881 the home directory of newly-created user accounts.
11883 For instance, a valid value may look like this:
11886 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
11887 (".guile" ,(plain-file "guile"
11888 "(use-modules (ice-9 readline))
11889 (activate-readline)")))
11892 @item @code{issue} (default: @code{%default-issue})
11893 A string denoting the contents of the @file{/etc/issue} file, which is
11894 displayed when users log in on a text console.
11896 @item @code{packages} (default: @code{%base-packages})
11897 The set of packages installed in the global profile, which is accessible
11898 at @file{/run/current-system/profile}.
11900 The default set includes core utilities and it is good practice to
11901 install non-core utilities in user profiles (@pxref{Invoking guix
11904 @item @code{timezone}
11905 A timezone identifying string---e.g., @code{"Europe/Paris"}.
11907 You can run the @command{tzselect} command to find out which timezone
11908 string corresponds to your region. Choosing an invalid timezone name
11909 causes @command{guix system} to fail.
11911 @item @code{locale} (default: @code{"en_US.utf8"})
11912 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
11913 Library Reference Manual}). @xref{Locales}, for more information.
11915 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
11916 The list of locale definitions to be compiled and that may be used at
11917 run time. @xref{Locales}.
11919 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
11920 The list of GNU@tie{}libc packages whose locale data and tools are used
11921 to build the locale definitions. @xref{Locales}, for compatibility
11922 considerations that justify this option.
11924 @item @code{name-service-switch} (default: @code{%default-nss})
11925 Configuration of the libc name service switch (NSS)---a
11926 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
11929 @item @code{services} (default: @code{%base-services})
11930 A list of service objects denoting system services. @xref{Services}.
11932 @cindex essential services
11933 @item @code{essential-services} (default: ...)
11934 The list of ``essential services''---i.e., things like instances of
11935 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
11936 Reference}), which are derived from the operating system definition itself.
11937 As a user you should @emph{never} need to touch this field.
11939 @item @code{pam-services} (default: @code{(base-pam-services)})
11941 @cindex pluggable authentication modules
11942 Linux @dfn{pluggable authentication module} (PAM) services.
11943 @c FIXME: Add xref to PAM services section.
11945 @item @code{setuid-programs} (default: @code{%setuid-programs})
11946 List of string-valued G-expressions denoting setuid programs.
11947 @xref{Setuid Programs}.
11949 @item @code{sudoers-file} (default: @code{%sudoers-specification})
11950 @cindex sudoers file
11951 The contents of the @file{/etc/sudoers} file as a file-like object
11952 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
11954 This file specifies which users can use the @command{sudo} command, what
11955 they are allowed to do, and what privileges they may gain. The default
11956 is that only @code{root} and members of the @code{wheel} group may use
11961 @deffn {Scheme Syntax} this-operating-system
11962 When used in the @emph{lexical scope} of an operating system field definition,
11963 this identifier resolves to the operating system being defined.
11965 The example below shows how to refer to the operating system being defined in
11966 the definition of the @code{label} field:
11969 (use-modules (gnu) (guix))
11973 (label (package-full-name
11974 (operating-system-kernel this-operating-system))))
11977 It is an error to refer to @code{this-operating-system} outside an operating
11984 @section File Systems
11986 The list of file systems to be mounted is specified in the
11987 @code{file-systems} field of the operating system declaration
11988 (@pxref{Using the Configuration System}). Each file system is declared
11989 using the @code{file-system} form, like this:
11993 (mount-point "/home")
11994 (device "/dev/sda3")
11998 As usual, some of the fields are mandatory---those shown in the example
11999 above---while others can be omitted. These are described below.
12001 @deftp {Data Type} file-system
12002 Objects of this type represent file systems to be mounted. They
12003 contain the following members:
12007 This is a string specifying the type of the file system---e.g.,
12010 @item @code{mount-point}
12011 This designates the place where the file system is to be mounted.
12013 @item @code{device}
12014 This names the ``source'' of the file system. It can be one of three
12015 things: a file system label, a file system UUID, or the name of a
12016 @file{/dev} node. Labels and UUIDs offer a way to refer to file
12017 systems without having to hard-code their actual device
12018 name@footnote{Note that, while it is tempting to use
12019 @file{/dev/disk/by-uuid} and similar device names to achieve the same
12020 result, this is not recommended: These special device nodes are created
12021 by the udev daemon and may be unavailable at the time the device is
12024 @findex file-system-label
12025 File system labels are created using the @code{file-system-label}
12026 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
12027 plain strings. Here's an example of a file system referred to by its
12028 label, as shown by the @command{e2label} command:
12032 (mount-point "/home")
12034 (device (file-system-label "my-home")))
12038 UUIDs are converted from their string representation (as shown by the
12039 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
12040 @code{uuid} form expects 16-byte UUIDs as defined in
12041 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
12042 form of UUID used by the ext2 family of file systems and others, but it
12043 is different from ``UUIDs'' found in FAT file systems, for instance.},
12048 (mount-point "/home")
12050 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
12053 When the source of a file system is a mapped device (@pxref{Mapped
12054 Devices}), its @code{device} field @emph{must} refer to the mapped
12055 device name---e.g., @file{"/dev/mapper/root-partition"}.
12056 This is required so that
12057 the system knows that mounting the file system depends on having the
12058 corresponding device mapping established.
12060 @item @code{flags} (default: @code{'()})
12061 This is a list of symbols denoting mount flags. Recognized flags
12062 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
12063 access to special files), @code{no-suid} (ignore setuid and setgid
12064 bits), @code{no-atime} (do not update file access times),
12065 @code{strict-atime} (update file access time), @code{lazy-time} (only
12066 update time on the in-memory version of the file inode), and
12067 @code{no-exec} (disallow program execution).
12068 @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
12069 Manual}, for more information on these flags.
12071 @item @code{options} (default: @code{#f})
12072 This is either @code{#f}, or a string denoting mount options passed to
12073 the file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C
12074 Library Reference Manual}, for details and run @command{man 8 mount} for
12075 options for various file systems. Note that the
12076 @code{file-system-options->alist} and @code{alist->file-system-options}
12077 procedures from @code{(gnu system file-systems)} can be used to convert
12078 file system options given as an association list to the string
12079 representation, and vice-versa.
12081 @item @code{mount?} (default: @code{#t})
12082 This value indicates whether to automatically mount the file system when
12083 the system is brought up. When set to @code{#f}, the file system gets
12084 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
12085 is not automatically mounted.
12087 @item @code{needed-for-boot?} (default: @code{#f})
12088 This Boolean value indicates whether the file system is needed when
12089 booting. If that is true, then the file system is mounted when the
12090 initial RAM disk (initrd) is loaded. This is always the case, for
12091 instance, for the root file system.
12093 @item @code{check?} (default: @code{#t})
12094 This Boolean indicates whether the file system needs to be checked for
12095 errors before being mounted.
12097 @item @code{create-mount-point?} (default: @code{#f})
12098 When true, the mount point is created if it does not exist yet.
12100 @item @code{dependencies} (default: @code{'()})
12101 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
12102 representing file systems that must be mounted or mapped devices that
12103 must be opened before (and unmounted or closed after) this one.
12105 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
12106 a dependency of @file{/sys/fs/cgroup/cpu} and
12107 @file{/sys/fs/cgroup/memory}.
12109 Another example is a file system that depends on a mapped device, for
12110 example for an encrypted partition (@pxref{Mapped Devices}).
12114 The @code{(gnu system file-systems)} exports the following useful
12117 @defvr {Scheme Variable} %base-file-systems
12118 These are essential file systems that are required on normal systems,
12119 such as @code{%pseudo-terminal-file-system} and @code{%immutable-store} (see
12120 below). Operating system declarations should always contain at least
12124 @defvr {Scheme Variable} %pseudo-terminal-file-system
12125 This is the file system to be mounted as @file{/dev/pts}. It supports
12126 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
12127 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
12128 Manual}). Pseudo-terminals are used by terminal emulators such as
12132 @defvr {Scheme Variable} %shared-memory-file-system
12133 This file system is mounted as @file{/dev/shm} and is used to support
12134 memory sharing across processes (@pxref{Memory-mapped I/O,
12135 @code{shm_open},, libc, The GNU C Library Reference Manual}).
12138 @defvr {Scheme Variable} %immutable-store
12139 This file system performs a read-only ``bind mount'' of
12140 @file{/gnu/store}, making it read-only for all the users including
12141 @code{root}. This prevents against accidental modification by software
12142 running as @code{root} or by system administrators.
12144 The daemon itself is still able to write to the store: it remounts it
12145 read-write in its own ``name space.''
12148 @defvr {Scheme Variable} %binary-format-file-system
12149 The @code{binfmt_misc} file system, which allows handling of arbitrary
12150 executable file types to be delegated to user space. This requires the
12151 @code{binfmt.ko} kernel module to be loaded.
12154 @defvr {Scheme Variable} %fuse-control-file-system
12155 The @code{fusectl} file system, which allows unprivileged users to mount
12156 and unmount user-space FUSE file systems. This requires the
12157 @code{fuse.ko} kernel module to be loaded.
12160 @node Btrfs file system
12161 @subsection Btrfs file system
12163 The Btrfs has special features, such as subvolumes, that merit being
12164 explained in more details. The following section attempts to cover
12165 basic as well as complex uses of a Btrfs file system with the Guix
12168 In its simplest usage, a Btrfs file system can be described, for
12173 (mount-point "/home")
12175 (device (file-system-label "my-home")))
12178 The example below is more complex, as it makes use of a Btrfs
12179 subvolume, named @code{rootfs}. The parent Btrfs file system is labeled
12180 @code{my-btrfs-pool}, and is located on an encrypted device (hence the
12181 dependency on @code{mapped-devices}):
12185 (device (file-system-label "my-btrfs-pool"))
12188 (options "subvol=rootfs")
12189 (dependencies mapped-devices))
12192 Some bootloaders, for example GRUB, only mount a Btrfs partition at its
12193 top level during the early boot, and rely on their configuration to
12194 refer to the correct subvolume path within that top level. The
12195 bootloaders operating in this way typically produce their configuration
12196 on a running system where the Btrfs partitions are already mounted and
12197 where the subvolume information is readily available. As an example,
12198 @command{grub-mkconfig}, the configuration generator command shipped
12199 with GRUB, reads @file{/proc/self/mountinfo} to determine the top-level
12200 path of a subvolume.
12202 The Guix System produces a bootloader configuration using the operating
12203 system configuration as its sole input; it is therefore necessary to
12204 extract the subvolume name on which @file{/gnu/store} lives (if any)
12205 from that operating system configuration. To better illustrate,
12206 consider a subvolume named 'rootfs' which contains the root file system
12207 data. In such situation, the GRUB bootloader would only see the top
12208 level of the root Btrfs partition, e.g.:
12212 ├── rootfs (subvolume directory)
12213 ├── gnu (normal directory)
12214 ├── store (normal directory)
12218 Thus, the subvolume name must be prepended to the @file{/gnu/store} path
12219 of the kernel, initrd binaries and any other files referred to in the
12220 GRUB configuration that must be found during the early boot.
12222 The next example shows a nested hierarchy of subvolumes and
12227 ├── rootfs (subvolume)
12228 ├── gnu (normal directory)
12229 ├── store (subvolume)
12233 This scenario would work without mounting the 'store' subvolume.
12234 Mounting 'rootfs' is sufficient, since the subvolume name matches its
12235 intended mount point in the file system hierarchy. Alternatively, the
12236 'store' subvolume could be referred to by setting the @code{subvol}
12237 option to either @code{/rootfs/gnu/store} or @code{rootfs/gnu/store}.
12239 Finally, a more contrived example of nested subvolumes:
12243 ├── root-snapshots (subvolume)
12244 ├── root-current (subvolume)
12245 ├── guix-store (subvolume)
12249 Here, the 'guix-store' subvolume doesn't match its intended mount point,
12250 so it is necessary to mount it. The subvolume must be fully specified,
12251 by passing its file name to the @code{subvol} option. To illustrate,
12252 the 'guix-store' subvolume could be mounted on @file{/gnu/store} by using
12253 a file system declaration such as:
12257 (device (file-system-label "btrfs-pool-1"))
12258 (mount-point "/gnu/store")
12260 (options "subvol=root-snapshots/root-current/guix-store,\
12261 compress-force=zstd,space_cache=v2"))
12264 @node Mapped Devices
12265 @section Mapped Devices
12267 @cindex device mapping
12268 @cindex mapped devices
12269 The Linux kernel has a notion of @dfn{device mapping}: a block device,
12270 such as a hard disk partition, can be @dfn{mapped} into another device,
12271 usually in @code{/dev/mapper/},
12272 with additional processing over the data that flows through
12273 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
12274 concept of a ``mapped device'' and that of a file system: both boil down
12275 to @emph{translating} input/output operations made on a file to
12276 operations on its backing store. Thus, the Hurd implements mapped
12277 devices, like file systems, using the generic @dfn{translator} mechanism
12278 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
12279 typical example is encryption device mapping: all writes to the mapped
12280 device are encrypted, and all reads are deciphered, transparently.
12281 Guix extends this notion by considering any device or set of devices that
12282 are @dfn{transformed} in some way to create a new device; for instance,
12283 RAID devices are obtained by @dfn{assembling} several other devices, such
12284 as hard disks or partitions, into a new one that behaves as one partition.
12285 Other examples, not yet implemented, are LVM logical volumes.
12287 Mapped devices are declared using the @code{mapped-device} form,
12288 defined as follows; for examples, see below.
12290 @deftp {Data Type} mapped-device
12291 Objects of this type represent device mappings that will be made when
12292 the system boots up.
12296 This is either a string specifying the name of the block device to be mapped,
12297 such as @code{"/dev/sda3"}, or a list of such strings when several devices
12298 need to be assembled for creating a new one.
12301 This string specifies the name of the resulting mapped device. For
12302 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
12303 specifying @code{"my-partition"} leads to the creation of
12304 the @code{"/dev/mapper/my-partition"} device.
12305 For RAID devices of type @code{raid-device-mapping}, the full device name
12306 such as @code{"/dev/md0"} needs to be given.
12309 This must be a @code{mapped-device-kind} object, which specifies how
12310 @var{source} is mapped to @var{target}.
12314 @defvr {Scheme Variable} luks-device-mapping
12315 This defines LUKS block device encryption using the @command{cryptsetup}
12316 command from the package with the same name. It relies on the
12317 @code{dm-crypt} Linux kernel module.
12320 @defvr {Scheme Variable} raid-device-mapping
12321 This defines a RAID device, which is assembled using the @code{mdadm}
12322 command from the package with the same name. It requires a Linux kernel
12323 module for the appropriate RAID level to be loaded, such as @code{raid456}
12324 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
12327 @cindex disk encryption
12329 The following example specifies a mapping from @file{/dev/sda3} to
12330 @file{/dev/mapper/home} using LUKS---the
12331 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
12332 standard mechanism for disk encryption.
12333 The @file{/dev/mapper/home}
12334 device can then be used as the @code{device} of a @code{file-system}
12335 declaration (@pxref{File Systems}).
12339 (source "/dev/sda3")
12341 (type luks-device-mapping))
12344 Alternatively, to become independent of device numbering, one may obtain
12345 the LUKS UUID (@dfn{unique identifier}) of the source device by a
12349 cryptsetup luksUUID /dev/sda3
12352 and use it as follows:
12356 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
12358 (type luks-device-mapping))
12361 @cindex swap encryption
12362 It is also desirable to encrypt swap space, since swap space may contain
12363 sensitive data. One way to accomplish that is to use a swap file in a
12364 file system on a device mapped via LUKS encryption. In this way, the
12365 swap file is encrypted because the entire device is encrypted.
12366 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
12368 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
12369 may be declared as follows:
12373 (source (list "/dev/sda1" "/dev/sdb1"))
12374 (target "/dev/md0")
12375 (type raid-device-mapping))
12378 The @file{/dev/md0} device can then be used as the @code{device} of a
12379 @code{file-system} declaration (@pxref{File Systems}).
12380 Note that the RAID level need not be given; it is chosen during the
12381 initial creation and formatting of the RAID device and is determined
12382 automatically later.
12385 @node User Accounts
12386 @section User Accounts
12390 @cindex user accounts
12391 User accounts and groups are entirely managed through the
12392 @code{operating-system} declaration. They are specified with the
12393 @code{user-account} and @code{user-group} forms:
12399 (supplementary-groups '("wheel" ;allow use of sudo, etc.
12400 "audio" ;sound card
12401 "video" ;video devices such as webcams
12402 "cdrom")) ;the good ol' CD-ROM
12403 (comment "Bob's sister")
12404 (home-directory "/home/alice"))
12407 When booting or upon completion of @command{guix system reconfigure},
12408 the system ensures that only the user accounts and groups specified in
12409 the @code{operating-system} declaration exist, and with the specified
12410 properties. Thus, account or group creations or modifications made by
12411 directly invoking commands such as @command{useradd} are lost upon
12412 reconfiguration or reboot. This ensures that the system remains exactly
12415 @deftp {Data Type} user-account
12416 Objects of this type represent user accounts. The following members may
12421 The name of the user account.
12425 This is the name (a string) or identifier (a number) of the user group
12426 this account belongs to.
12428 @item @code{supplementary-groups} (default: @code{'()})
12429 Optionally, this can be defined as a list of group names that this
12430 account belongs to.
12432 @item @code{uid} (default: @code{#f})
12433 This is the user ID for this account (a number), or @code{#f}. In the
12434 latter case, a number is automatically chosen by the system when the
12435 account is created.
12437 @item @code{comment} (default: @code{""})
12438 A comment about the account, such as the account owner's full name.
12440 @item @code{home-directory}
12441 This is the name of the home directory for the account.
12443 @item @code{create-home-directory?} (default: @code{#t})
12444 Indicates whether the home directory of this account should be created
12445 if it does not exist yet.
12447 @item @code{shell} (default: Bash)
12448 This is a G-expression denoting the file name of a program to be used as
12449 the shell (@pxref{G-Expressions}).
12451 @item @code{system?} (default: @code{#f})
12452 This Boolean value indicates whether the account is a ``system''
12453 account. System accounts are sometimes treated specially; for instance,
12454 graphical login managers do not list them.
12456 @anchor{user-account-password}
12457 @cindex password, for user accounts
12458 @item @code{password} (default: @code{#f})
12459 You would normally leave this field to @code{#f}, initialize user
12460 passwords as @code{root} with the @command{passwd} command, and then let
12461 users change it with @command{passwd}. Passwords set with
12462 @command{passwd} are of course preserved across reboot and
12465 If you @emph{do} want to set an initial password for an account, then
12466 this field must contain the encrypted password, as a string. You can use the
12467 @code{crypt} procedure for this purpose:
12474 ;; Specify a SHA-512-hashed initial password.
12475 (password (crypt "InitialPassword!" "$6$abc")))
12479 The hash of this initial password will be available in a file in
12480 @file{/gnu/store}, readable by all the users, so this method must be used with
12484 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
12485 more information on password encryption, and @ref{Encryption,,, guile, GNU
12486 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
12492 User group declarations are even simpler:
12495 (user-group (name "students"))
12498 @deftp {Data Type} user-group
12499 This type is for, well, user groups. There are just a few fields:
12503 The name of the group.
12505 @item @code{id} (default: @code{#f})
12506 The group identifier (a number). If @code{#f}, a new number is
12507 automatically allocated when the group is created.
12509 @item @code{system?} (default: @code{#f})
12510 This Boolean value indicates whether the group is a ``system'' group.
12511 System groups have low numerical IDs.
12513 @item @code{password} (default: @code{#f})
12514 What, user groups can have a password? Well, apparently yes. Unless
12515 @code{#f}, this field specifies the password of the group.
12520 For convenience, a variable lists all the basic user groups one may
12523 @defvr {Scheme Variable} %base-groups
12524 This is the list of basic user groups that users and/or packages expect
12525 to be present on the system. This includes groups such as ``root'',
12526 ``wheel'', and ``users'', as well as groups used to control access to
12527 specific devices such as ``audio'', ``disk'', and ``cdrom''.
12530 @defvr {Scheme Variable} %base-user-accounts
12531 This is the list of basic system accounts that programs may expect to
12532 find on a GNU/Linux system, such as the ``nobody'' account.
12534 Note that the ``root'' account is not included here. It is a
12535 special-case and is automatically added whether or not it is specified.
12538 @node Keyboard Layout
12539 @section Keyboard Layout
12541 @cindex keyboard layout
12543 To specify what each key of your keyboard does, you need to tell the operating
12544 system what @dfn{keyboard layout} you want to use. The default, when nothing
12545 is specified, is the US English QWERTY layout for 105-key PC keyboards.
12546 However, German speakers will usually prefer the German QWERTZ layout, French
12547 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
12548 or bépo, and they might even want to further customize the effect of some of
12549 the keys. This section explains how to get that done.
12551 @cindex keyboard layout, definition
12552 There are three components that will want to know about your keyboard layout:
12556 The @emph{bootloader} may want to know what keyboard layout you want to use
12557 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
12558 you want, for instance, to make sure that you can type the passphrase of your
12559 encrypted root partition using the right layout.
12562 The @emph{operating system kernel}, Linux, will need that so that the console
12563 is properly configured (@pxref{operating-system Reference,
12564 @code{keyboard-layout}}).
12567 The @emph{graphical display server}, usually Xorg, also has its own idea of
12568 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
12571 Guix allows you to configure all three separately but, fortunately, it allows
12572 you to share the same keyboard layout for all three components.
12574 @cindex XKB, keyboard layouts
12575 Keyboard layouts are represented by records created by the
12576 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
12577 the X Keyboard extension (XKB), each layout has four attributes: a name (often
12578 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
12579 optional variant name, an optional keyboard model name, and a possibly empty
12580 list of additional options. In most cases the layout name is all you care
12581 about. Here are a few example:
12584 ;; The German QWERTZ layout. Here we assume a standard
12585 ;; "pc105" keyboard model.
12586 (keyboard-layout "de")
12588 ;; The bépo variant of the French layout.
12589 (keyboard-layout "fr" "bepo")
12591 ;; The Catalan layout.
12592 (keyboard-layout "es" "cat")
12594 ;; Arabic layout with "Alt-Shift" to switch to US layout.
12595 (keyboard-layout "ar,us" #:options '("grp:alt_shift_toggle"))
12597 ;; The Latin American Spanish layout. In addition, the
12598 ;; "Caps Lock" key is used as an additional "Ctrl" key,
12599 ;; and the "Menu" key is used as a "Compose" key to enter
12600 ;; accented letters.
12601 (keyboard-layout "latam"
12602 #:options '("ctrl:nocaps" "compose:menu"))
12604 ;; The Russian layout for a ThinkPad keyboard.
12605 (keyboard-layout "ru" #:model "thinkpad")
12607 ;; The "US international" layout, which is the US layout plus
12608 ;; dead keys to enter accented characters. This is for an
12609 ;; Apple MacBook keyboard.
12610 (keyboard-layout "us" "intl" #:model "macbook78")
12613 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
12614 for a complete list of supported layouts, variants, and models.
12616 @cindex keyboard layout, configuration
12617 Let's say you want your system to use the Turkish keyboard layout throughout
12618 your system---bootloader, console, and Xorg. Here's what your system
12619 configuration would look like:
12621 @findex set-xorg-configuration
12623 ;; Using the Turkish layout for the bootloader, the console,
12628 (keyboard-layout (keyboard-layout "tr")) ;for the console
12629 (bootloader (bootloader-configuration
12630 (bootloader grub-efi-bootloader)
12631 (target "/boot/efi")
12632 (keyboard-layout keyboard-layout))) ;for GRUB
12633 (services (cons (set-xorg-configuration
12634 (xorg-configuration ;for Xorg
12635 (keyboard-layout keyboard-layout)))
12636 %desktop-services)))
12639 In the example above, for GRUB and for Xorg, we just refer to the
12640 @code{keyboard-layout} field defined above, but we could just as well refer to
12641 a different layout. The @code{set-xorg-configuration} procedure communicates
12642 the desired Xorg configuration to the graphical log-in manager, by default
12645 We've discussed how to specify the @emph{default} keyboard layout of your
12646 system when it starts, but you can also adjust it at run time:
12650 If you're using GNOME, its settings panel has a ``Region & Language'' entry
12651 where you can select one or more keyboard layouts.
12654 Under Xorg, the @command{setxkbmap} command (from the same-named package)
12655 allows you to change the current layout. For example, this is how you would
12656 change the layout to US Dvorak:
12659 setxkbmap us dvorak
12663 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
12664 console. However, note that @code{loadkeys} does @emph{not} use the XKB
12665 keyboard layout categorization described above. The command below loads the
12666 French bépo layout:
12677 A @dfn{locale} defines cultural conventions for a particular language
12678 and region of the world (@pxref{Locales,,, libc, The GNU C Library
12679 Reference Manual}). Each locale has a name that typically has the form
12680 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
12681 @code{fr_LU.utf8} designates the locale for the French language, with
12682 cultural conventions from Luxembourg, and using the UTF-8 encoding.
12684 @cindex locale definition
12685 Usually, you will want to specify the default locale for the machine
12686 using the @code{locale} field of the @code{operating-system} declaration
12687 (@pxref{operating-system Reference, @code{locale}}).
12689 The selected locale is automatically added to the @dfn{locale
12690 definitions} known to the system if needed, with its codeset inferred
12691 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
12692 @code{UTF-8} codeset. Additional locale definitions can be specified in
12693 the @code{locale-definitions} slot of @code{operating-system}---this is
12694 useful, for instance, if the codeset could not be inferred from the
12695 locale name. The default set of locale definitions includes some widely
12696 used locales, but not all the available locales, in order to save space.
12698 For instance, to add the North Frisian locale for Germany, the value of
12702 (cons (locale-definition
12703 (name "fy_DE.utf8") (source "fy_DE"))
12704 %default-locale-definitions)
12707 Likewise, to save space, one might want @code{locale-definitions} to
12708 list only the locales that are actually used, as in:
12711 (list (locale-definition
12712 (name "ja_JP.eucjp") (source "ja_JP")
12713 (charset "EUC-JP")))
12717 The compiled locale definitions are available at
12718 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
12719 version, which is the default location where the GNU@tie{}libc provided
12720 by Guix looks for locale data. This can be overridden using the
12721 @env{LOCPATH} environment variable (@pxref{locales-and-locpath,
12722 @env{LOCPATH} and locale packages}).
12724 The @code{locale-definition} form is provided by the @code{(gnu system
12725 locale)} module. Details are given below.
12727 @deftp {Data Type} locale-definition
12728 This is the data type of a locale definition.
12733 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
12734 Reference Manual}, for more information on locale names.
12736 @item @code{source}
12737 The name of the source for that locale. This is typically the
12738 @code{@var{language}_@var{territory}} part of the locale name.
12740 @item @code{charset} (default: @code{"UTF-8"})
12741 The ``character set'' or ``code set'' for that locale,
12742 @uref{https://www.iana.org/assignments/character-sets, as defined by
12748 @defvr {Scheme Variable} %default-locale-definitions
12749 A list of commonly used UTF-8 locales, used as the default
12750 value of the @code{locale-definitions} field of @code{operating-system}
12753 @cindex locale name
12754 @cindex normalized codeset in locale names
12755 These locale definitions use the @dfn{normalized codeset} for the part
12756 that follows the dot in the name (@pxref{Using gettextized software,
12757 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
12758 instance it has @code{uk_UA.utf8} but @emph{not}, say,
12759 @code{uk_UA.UTF-8}.
12762 @subsection Locale Data Compatibility Considerations
12764 @cindex incompatibility, of locale data
12765 @code{operating-system} declarations provide a @code{locale-libcs} field
12766 to specify the GNU@tie{}libc packages that are used to compile locale
12767 declarations (@pxref{operating-system Reference}). ``Why would I
12768 care?'', you may ask. Well, it turns out that the binary format of
12769 locale data is occasionally incompatible from one libc version to
12772 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
12773 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
12774 For instance, a program linked against libc version 2.21 is unable to
12775 read locale data produced with libc 2.22; worse, that program
12776 @emph{aborts} instead of simply ignoring the incompatible locale
12777 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
12778 the incompatible locale data, which is already an improvement.}.
12779 Similarly, a program linked against libc 2.22 can read most, but not
12780 all, of the locale data from libc 2.21 (specifically, @env{LC_COLLATE}
12781 data is incompatible); thus calls to @code{setlocale} may fail, but
12782 programs will not abort.
12784 The ``problem'' with Guix is that users have a lot of freedom: They can
12785 choose whether and when to upgrade software in their profiles, and might
12786 be using a libc version different from the one the system administrator
12787 used to build the system-wide locale data.
12789 Fortunately, unprivileged users can also install their own locale data
12790 and define @env{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
12791 @env{GUIX_LOCPATH} and locale packages}).
12793 Still, it is best if the system-wide locale data at
12794 @file{/run/current-system/locale} is built for all the libc versions
12795 actually in use on the system, so that all the programs can access
12796 it---this is especially crucial on a multi-user system. To do that, the
12797 administrator can specify several libc packages in the
12798 @code{locale-libcs} field of @code{operating-system}:
12801 (use-package-modules base)
12805 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
12808 This example would lead to a system containing locale definitions for
12809 both libc 2.21 and the current version of libc in
12810 @file{/run/current-system/locale}.
12816 @cindex system services
12817 An important part of preparing an @code{operating-system} declaration is
12818 listing @dfn{system services} and their configuration (@pxref{Using the
12819 Configuration System}). System services are typically daemons launched
12820 when the system boots, or other actions needed at that time---e.g.,
12821 configuring network access.
12823 Guix has a broad definition of ``service'' (@pxref{Service
12824 Composition}), but many services are managed by the GNU@tie{}Shepherd
12825 (@pxref{Shepherd Services}). On a running system, the @command{herd}
12826 command allows you to list the available services, show their status,
12827 start and stop them, or do other specific operations (@pxref{Jump
12828 Start,,, shepherd, The GNU Shepherd Manual}). For example:
12834 The above command, run as @code{root}, lists the currently defined
12835 services. The @command{herd doc} command shows a synopsis of the given
12836 service and its associated actions:
12840 Run libc's name service cache daemon (nscd).
12842 # herd doc nscd action invalidate
12843 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
12846 The @command{start}, @command{stop}, and @command{restart} sub-commands
12847 have the effect you would expect. For instance, the commands below stop
12848 the nscd service and restart the Xorg display server:
12852 Service nscd has been stopped.
12853 # herd restart xorg-server
12854 Service xorg-server has been stopped.
12855 Service xorg-server has been started.
12858 The following sections document the available services, starting with
12859 the core services, that may be used in an @code{operating-system}
12863 * Base Services:: Essential system services.
12864 * Scheduled Job Execution:: The mcron service.
12865 * Log Rotation:: The rottlog service.
12866 * Networking Services:: Network setup, SSH daemon, etc.
12867 * X Window:: Graphical display.
12868 * Printing Services:: Local and remote printer support.
12869 * Desktop Services:: D-Bus and desktop services.
12870 * Sound Services:: ALSA and Pulseaudio services.
12871 * Database Services:: SQL databases, key-value stores, etc.
12872 * Mail Services:: IMAP, POP3, SMTP, and all that.
12873 * Messaging Services:: Messaging services.
12874 * Telephony Services:: Telephony services.
12875 * Monitoring Services:: Monitoring services.
12876 * Kerberos Services:: Kerberos services.
12877 * LDAP Services:: LDAP services.
12878 * Web Services:: Web servers.
12879 * Certificate Services:: TLS certificates via Let's Encrypt.
12880 * DNS Services:: DNS daemons.
12881 * VPN Services:: VPN daemons.
12882 * Network File System:: NFS related services.
12883 * Continuous Integration:: The Cuirass service.
12884 * Power Management Services:: Extending battery life.
12885 * Audio Services:: The MPD.
12886 * Virtualization Services:: Virtualization services.
12887 * Version Control Services:: Providing remote access to Git repositories.
12888 * Game Services:: Game servers.
12889 * PAM Mount Service:: Service to mount volumes when logging in.
12890 * Guix Services:: Services relating specifically to Guix.
12891 * Linux Services:: Services tied to the Linux kernel.
12892 * Hurd Services:: Services specific for a Hurd System.
12893 * Miscellaneous Services:: Other services.
12896 @node Base Services
12897 @subsection Base Services
12899 The @code{(gnu services base)} module provides definitions for the basic
12900 services that one expects from the system. The services exported by
12901 this module are listed below.
12903 @defvr {Scheme Variable} %base-services
12904 This variable contains a list of basic services (@pxref{Service Types
12905 and Services}, for more information on service objects) one would
12906 expect from the system: a login service (mingetty) on each tty, syslogd,
12907 the libc name service cache daemon (nscd), the udev device manager, and
12910 This is the default value of the @code{services} field of
12911 @code{operating-system} declarations. Usually, when customizing a
12912 system, you will want to append services to @code{%base-services}, like
12916 (append (list (service avahi-service-type)
12917 (service openssh-service-type))
12922 @defvr {Scheme Variable} special-files-service-type
12923 This is the service that sets up ``special files'' such as
12924 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
12926 The value associated with @code{special-files-service-type} services
12927 must be a list of tuples where the first element is the ``special file''
12928 and the second element is its target. By default it is:
12930 @cindex @file{/bin/sh}
12931 @cindex @file{sh}, in @file{/bin}
12933 `(("/bin/sh" ,(file-append bash "/bin/sh")))
12936 @cindex @file{/usr/bin/env}
12937 @cindex @file{env}, in @file{/usr/bin}
12938 If you want to add, say, @code{/usr/bin/env} to your system, you can
12942 `(("/bin/sh" ,(file-append bash "/bin/sh"))
12943 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
12946 Since this is part of @code{%base-services}, you can use
12947 @code{modify-services} to customize the set of special files
12948 (@pxref{Service Reference, @code{modify-services}}). But the simple way
12949 to add a special file is @i{via} the @code{extra-special-file} procedure
12953 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
12954 Use @var{target} as the ``special file'' @var{file}.
12956 For example, adding the following lines to the @code{services} field of
12957 your operating system declaration leads to a @file{/usr/bin/env}
12961 (extra-special-file "/usr/bin/env"
12962 (file-append coreutils "/bin/env"))
12966 @deffn {Scheme Procedure} host-name-service @var{name}
12967 Return a service that sets the host name to @var{name}.
12970 @defvr {Scheme Variable} console-font-service-type
12971 Install the given fonts on the specified ttys (fonts are per
12972 virtual console on the kernel Linux). The value of this service is a list of
12973 tty/font pairs. The font can be the name of a font provided by the @code{kbd}
12974 package or any valid argument to @command{setfont}, as in this example:
12977 `(("tty1" . "LatGrkCyr-8x16")
12978 ("tty2" . ,(file-append
12980 "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
12981 ("tty3" . ,(file-append
12983 "/share/consolefonts/ter-132n"))) ; for HDPI
12987 @deffn {Scheme Procedure} login-service @var{config}
12988 Return a service to run login according to @var{config}, a
12989 @code{<login-configuration>} object, which specifies the message of the day,
12990 among other things.
12993 @deftp {Data Type} login-configuration
12994 This is the data type representing the configuration of login.
12999 @cindex message of the day
13000 A file-like object containing the ``message of the day''.
13002 @item @code{allow-empty-passwords?} (default: @code{#t})
13003 Allow empty passwords by default so that first-time users can log in when
13004 the 'root' account has just been created.
13009 @deffn {Scheme Procedure} mingetty-service @var{config}
13010 Return a service to run mingetty according to @var{config}, a
13011 @code{<mingetty-configuration>} object, which specifies the tty to run, among
13015 @deftp {Data Type} mingetty-configuration
13016 This is the data type representing the configuration of Mingetty, which
13017 provides the default implementation of virtual console log-in.
13022 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
13024 @item @code{auto-login} (default: @code{#f})
13025 When true, this field must be a string denoting the user name under
13026 which the system automatically logs in. When it is @code{#f}, a
13027 user name and password must be entered to log in.
13029 @item @code{login-program} (default: @code{#f})
13030 This must be either @code{#f}, in which case the default log-in program
13031 is used (@command{login} from the Shadow tool suite), or a gexp denoting
13032 the name of the log-in program.
13034 @item @code{login-pause?} (default: @code{#f})
13035 When set to @code{#t} in conjunction with @var{auto-login}, the user
13036 will have to press a key before the log-in shell is launched.
13038 @item @code{mingetty} (default: @var{mingetty})
13039 The Mingetty package to use.
13044 @deffn {Scheme Procedure} agetty-service @var{config}
13045 Return a service to run agetty according to @var{config}, an
13046 @code{<agetty-configuration>} object, which specifies the tty to run,
13047 among other things.
13050 @deftp {Data Type} agetty-configuration
13051 This is the data type representing the configuration of agetty, which
13052 implements virtual and serial console log-in. See the @code{agetty(8)}
13053 man page for more information.
13058 The name of the console this agetty runs on, as a string---e.g.,
13059 @code{"ttyS0"}. This argument is optional, it will default to
13060 a reasonable default serial port used by the kernel Linux.
13062 For this, if there is a value for an option @code{agetty.tty} in the kernel
13063 command line, agetty will extract the device name of the serial port
13064 from it and use that.
13066 If not and if there is a value for an option @code{console} with a tty in
13067 the Linux command line, agetty will extract the device name of the
13068 serial port from it and use that.
13070 In both cases, agetty will leave the other serial device settings
13071 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
13074 @item @code{baud-rate} (default: @code{#f})
13075 A string containing a comma-separated list of one or more baud rates, in
13078 @item @code{term} (default: @code{#f})
13079 A string containing the value used for the @env{TERM} environment
13082 @item @code{eight-bits?} (default: @code{#f})
13083 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
13086 @item @code{auto-login} (default: @code{#f})
13087 When passed a login name, as a string, the specified user will be logged
13088 in automatically without prompting for their login name or password.
13090 @item @code{no-reset?} (default: @code{#f})
13091 When @code{#t}, don't reset terminal cflags (control modes).
13093 @item @code{host} (default: @code{#f})
13094 This accepts a string containing the ``login_host'', which will be written
13095 into the @file{/var/run/utmpx} file.
13097 @item @code{remote?} (default: @code{#f})
13098 When set to @code{#t} in conjunction with @var{host}, this will add an
13099 @code{-r} fakehost option to the command line of the login program
13100 specified in @var{login-program}.
13102 @item @code{flow-control?} (default: @code{#f})
13103 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
13105 @item @code{no-issue?} (default: @code{#f})
13106 When set to @code{#t}, the contents of the @file{/etc/issue} file will
13107 not be displayed before presenting the login prompt.
13109 @item @code{init-string} (default: @code{#f})
13110 This accepts a string that will be sent to the tty or modem before
13111 sending anything else. It can be used to initialize a modem.
13113 @item @code{no-clear?} (default: @code{#f})
13114 When set to @code{#t}, agetty will not clear the screen before showing
13117 @item @code{login-program} (default: (file-append shadow "/bin/login"))
13118 This must be either a gexp denoting the name of a log-in program, or
13119 unset, in which case the default value is the @command{login} from the
13122 @item @code{local-line} (default: @code{#f})
13123 Control the CLOCAL line flag. This accepts one of three symbols as
13124 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
13125 the default value chosen by agetty is @code{'auto}.
13127 @item @code{extract-baud?} (default: @code{#f})
13128 When set to @code{#t}, instruct agetty to try to extract the baud rate
13129 from the status messages produced by certain types of modems.
13131 @item @code{skip-login?} (default: @code{#f})
13132 When set to @code{#t}, do not prompt the user for a login name. This
13133 can be used with @var{login-program} field to use non-standard login
13136 @item @code{no-newline?} (default: @code{#f})
13137 When set to @code{#t}, do not print a newline before printing the
13138 @file{/etc/issue} file.
13140 @c Is this dangerous only when used with login-program, or always?
13141 @item @code{login-options} (default: @code{#f})
13142 This option accepts a string containing options that are passed to the
13143 login program. When used with the @var{login-program}, be aware that a
13144 malicious user could try to enter a login name containing embedded
13145 options that could be parsed by the login program.
13147 @item @code{login-pause} (default: @code{#f})
13148 When set to @code{#t}, wait for any key before showing the login prompt.
13149 This can be used in conjunction with @var{auto-login} to save memory by
13150 lazily spawning shells.
13152 @item @code{chroot} (default: @code{#f})
13153 Change root to the specified directory. This option accepts a directory
13156 @item @code{hangup?} (default: @code{#f})
13157 Use the Linux system call @code{vhangup} to do a virtual hangup of the
13158 specified terminal.
13160 @item @code{keep-baud?} (default: @code{#f})
13161 When set to @code{#t}, try to keep the existing baud rate. The baud
13162 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
13165 @item @code{timeout} (default: @code{#f})
13166 When set to an integer value, terminate if no user name could be read
13167 within @var{timeout} seconds.
13169 @item @code{detect-case?} (default: @code{#f})
13170 When set to @code{#t}, turn on support for detecting an uppercase-only
13171 terminal. This setting will detect a login name containing only
13172 uppercase letters as indicating an uppercase-only terminal and turn on
13173 some upper-to-lower case conversions. Note that this will not support
13174 Unicode characters.
13176 @item @code{wait-cr?} (default: @code{#f})
13177 When set to @code{#t}, wait for the user or modem to send a
13178 carriage-return or linefeed character before displaying
13179 @file{/etc/issue} or login prompt. This is typically used with the
13180 @var{init-string} option.
13182 @item @code{no-hints?} (default: @code{#f})
13183 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
13186 @item @code{no-hostname?} (default: @code{#f})
13187 By default, the hostname is printed. When this option is set to
13188 @code{#t}, no hostname will be shown at all.
13190 @item @code{long-hostname?} (default: @code{#f})
13191 By default, the hostname is only printed until the first dot. When this
13192 option is set to @code{#t}, the fully qualified hostname by
13193 @code{gethostname} or @code{getaddrinfo} is shown.
13195 @item @code{erase-characters} (default: @code{#f})
13196 This option accepts a string of additional characters that should be
13197 interpreted as backspace when the user types their login name.
13199 @item @code{kill-characters} (default: @code{#f})
13200 This option accepts a string that should be interpreted to mean ``ignore
13201 all previous characters'' (also called a ``kill'' character) when the user
13202 types their login name.
13204 @item @code{chdir} (default: @code{#f})
13205 This option accepts, as a string, a directory path that will be changed
13208 @item @code{delay} (default: @code{#f})
13209 This options accepts, as an integer, the number of seconds to sleep
13210 before opening the tty and displaying the login prompt.
13212 @item @code{nice} (default: @code{#f})
13213 This option accepts, as an integer, the nice value with which to run the
13214 @command{login} program.
13216 @item @code{extra-options} (default: @code{'()})
13217 This option provides an ``escape hatch'' for the user to provide arbitrary
13218 command-line arguments to @command{agetty} as a list of strings.
13223 @deffn {Scheme Procedure} kmscon-service-type @var{config}
13224 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
13225 according to @var{config}, a @code{<kmscon-configuration>} object, which
13226 specifies the tty to run, among other things.
13229 @deftp {Data Type} kmscon-configuration
13230 This is the data type representing the configuration of Kmscon, which
13231 implements virtual console log-in.
13235 @item @code{virtual-terminal}
13236 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
13238 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
13239 A gexp denoting the name of the log-in program. The default log-in program is
13240 @command{login} from the Shadow tool suite.
13242 @item @code{login-arguments} (default: @code{'("-p")})
13243 A list of arguments to pass to @command{login}.
13245 @item @code{auto-login} (default: @code{#f})
13246 When passed a login name, as a string, the specified user will be logged
13247 in automatically without prompting for their login name or password.
13249 @item @code{hardware-acceleration?} (default: #f)
13250 Whether to use hardware acceleration.
13252 @item @code{kmscon} (default: @var{kmscon})
13253 The Kmscon package to use.
13258 @cindex name service cache daemon
13260 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
13261 [#:name-services '()]
13262 Return a service that runs the libc name service cache daemon (nscd) with the
13263 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
13264 Service Switch}, for an example.
13266 For convenience, the Shepherd service for nscd provides the following actions:
13270 @cindex cache invalidation, nscd
13271 @cindex nscd, cache invalidation
13272 This invalidate the given cache. For instance, running:
13275 herd invalidate nscd hosts
13279 invalidates the host name lookup cache of nscd.
13282 Running @command{herd statistics nscd} displays information about nscd usage
13288 @defvr {Scheme Variable} %nscd-default-configuration
13289 This is the default @code{<nscd-configuration>} value (see below) used
13290 by @code{nscd-service}. It uses the caches defined by
13291 @code{%nscd-default-caches}; see below.
13294 @deftp {Data Type} nscd-configuration
13295 This is the data type representing the name service cache daemon (nscd)
13300 @item @code{name-services} (default: @code{'()})
13301 List of packages denoting @dfn{name services} that must be visible to
13302 the nscd---e.g., @code{(list @var{nss-mdns})}.
13304 @item @code{glibc} (default: @var{glibc})
13305 Package object denoting the GNU C Library providing the @command{nscd}
13308 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
13309 Name of the nscd log file. This is where debugging output goes when
13310 @code{debug-level} is strictly positive.
13312 @item @code{debug-level} (default: @code{0})
13313 Integer denoting the debugging levels. Higher numbers mean that more
13314 debugging output is logged.
13316 @item @code{caches} (default: @code{%nscd-default-caches})
13317 List of @code{<nscd-cache>} objects denoting things to be cached; see
13323 @deftp {Data Type} nscd-cache
13324 Data type representing a cache database of nscd and its parameters.
13328 @item @code{database}
13329 This is a symbol representing the name of the database to be cached.
13330 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
13331 @code{services}, which designate the corresponding NSS database
13332 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
13334 @item @code{positive-time-to-live}
13335 @itemx @code{negative-time-to-live} (default: @code{20})
13336 A number representing the number of seconds during which a positive or
13337 negative lookup result remains in cache.
13339 @item @code{check-files?} (default: @code{#t})
13340 Whether to check for updates of the files corresponding to
13343 For instance, when @var{database} is @code{hosts}, setting this flag
13344 instructs nscd to check for updates in @file{/etc/hosts} and to take
13347 @item @code{persistent?} (default: @code{#t})
13348 Whether the cache should be stored persistently on disk.
13350 @item @code{shared?} (default: @code{#t})
13351 Whether the cache should be shared among users.
13353 @item @code{max-database-size} (default: 32@tie{}MiB)
13354 Maximum size in bytes of the database cache.
13356 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
13357 @c settings, so leave them out.
13362 @defvr {Scheme Variable} %nscd-default-caches
13363 List of @code{<nscd-cache>} objects used by default by
13364 @code{nscd-configuration} (see above).
13366 It enables persistent and aggressive caching of service and host name
13367 lookups. The latter provides better host name lookup performance,
13368 resilience in the face of unreliable name servers, and also better
13369 privacy---often the result of host name lookups is in local cache, so
13370 external name servers do not even need to be queried.
13373 @anchor{syslog-configuration-type}
13376 @deftp {Data Type} syslog-configuration
13377 This data type represents the configuration of the syslog daemon.
13380 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
13381 The syslog daemon to use.
13383 @item @code{config-file} (default: @code{%default-syslog.conf})
13384 The syslog configuration file to use.
13389 @anchor{syslog-service}
13391 @deffn {Scheme Procedure} syslog-service @var{config}
13392 Return a service that runs a syslog daemon according to @var{config}.
13394 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
13395 information on the configuration file syntax.
13398 @defvr {Scheme Variable} guix-service-type
13399 This is the type of the service that runs the build daemon,
13400 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
13401 @code{guix-configuration} record as described below.
13404 @anchor{guix-configuration-type}
13405 @deftp {Data Type} guix-configuration
13406 This data type represents the configuration of the Guix build daemon.
13407 @xref{Invoking guix-daemon}, for more information.
13410 @item @code{guix} (default: @var{guix})
13411 The Guix package to use.
13413 @item @code{build-group} (default: @code{"guixbuild"})
13414 Name of the group for build user accounts.
13416 @item @code{build-accounts} (default: @code{10})
13417 Number of build user accounts to create.
13419 @item @code{authorize-key?} (default: @code{#t})
13420 @cindex substitutes, authorization thereof
13421 Whether to authorize the substitute keys listed in
13422 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
13423 (@pxref{Substitutes}).
13425 @vindex %default-authorized-guix-keys
13426 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
13427 The list of authorized key files for archive imports, as a list of
13428 string-valued gexps (@pxref{Invoking guix archive}). By default, it
13429 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
13431 @item @code{use-substitutes?} (default: @code{#t})
13432 Whether to use substitutes.
13434 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
13435 The list of URLs where to look for substitutes by default.
13437 @item @code{max-silent-time} (default: @code{0})
13438 @itemx @code{timeout} (default: @code{0})
13439 The number of seconds of silence and the number of seconds of activity,
13440 respectively, after which a build process times out. A value of zero
13441 disables the timeout.
13443 @item @code{log-compression} (default: @code{'bzip2})
13444 The type of compression used for build logs---one of @code{gzip},
13445 @code{bzip2}, or @code{none}.
13447 @item @code{extra-options} (default: @code{'()})
13448 List of extra command-line options for @command{guix-daemon}.
13450 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
13451 File where @command{guix-daemon}'s standard output and standard error
13454 @cindex HTTP proxy, for @code{guix-daemon}
13455 @cindex proxy, for @code{guix-daemon} HTTP access
13456 @item @code{http-proxy} (default: @code{#f})
13457 The URL of the HTTP and HTTPS proxy used for downloading fixed-output
13458 derivations and substitutes.
13460 It is also possible to change the daemon's proxy at run time through the
13461 @code{set-http-proxy} action, which restarts it:
13464 herd set-http-proxy guix-daemon http://localhost:8118
13467 To clear the proxy settings, run:
13470 herd set-http-proxy guix-daemon
13473 @item @code{tmpdir} (default: @code{#f})
13474 A directory path where the @command{guix-daemon} will perform builds.
13479 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
13480 Run @var{udev}, which populates the @file{/dev} directory dynamically.
13481 udev rules can be provided as a list of files through the @var{rules}
13482 variable. The procedures @code{udev-rule}, @code{udev-rules-service}
13483 and @code{file->udev-rule} from @code{(gnu services base)} simplify the
13484 creation of such rule files.
13486 The @command{herd rules udev} command, as root, returns the name of the
13487 directory containing all the active udev rules.
13490 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
13491 Return a udev-rule file named @var{file-name} containing the rules
13492 defined by the @var{contents} literal.
13494 In the following example, a rule for a USB device is defined to be
13495 stored in the file @file{90-usb-thing.rules}. The rule runs a script
13496 upon detecting a USB device with a given product identifier.
13499 (define %example-udev-rule
13501 "90-usb-thing.rules"
13502 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
13503 "ATTR@{product@}==\"Example\", "
13504 "RUN+=\"/path/to/script\"")))
13508 @deffn {Scheme Procedure} udev-rules-service [@var{name} @var{rules}] @
13509 [#:groups @var{groups}]
13510 Return a service that extends @code{udev-service-type } with @var{rules}
13511 and @code{account-service-type} with @var{groups} as system groups.
13512 This works by creating a singleton service type
13513 @code{@var{name}-udev-rules}, of which the returned service is an
13516 Here we show how it can be used to extend @code{udev-service-type} with the
13517 previously defined rule @code{%example-udev-rule}.
13523 (cons (udev-rules-service 'usb-thing %example-udev-rule)
13524 %desktop-services)))
13528 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
13529 Return a udev file named @var{file-name} containing the rules defined
13530 within @var{file}, a file-like object.
13532 The following example showcases how we can use an existing rule file.
13535 (use-modules (guix download) ;for url-fetch
13536 (guix packages) ;for origin
13539 (define %android-udev-rules
13541 "51-android-udev.rules"
13542 (let ((version "20170910"))
13545 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
13546 "android-udev-rules/" version "/51-android.rules"))
13548 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
13552 Additionally, Guix package definitions can be included in @var{rules} in
13553 order to extend the udev rules with the definitions found under their
13554 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
13555 @var{file->udev-rule} example, we could have used the
13556 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
13557 packages android)} module.
13559 The following example shows how to use the @var{android-udev-rules}
13560 package so that the Android tool @command{adb} can detect devices
13561 without root privileges. It also details how to create the
13562 @code{adbusers} group, which is required for the proper functioning of
13563 the rules defined within the @code{android-udev-rules} package. To
13564 create such a group, we must define it both as part of the
13565 @code{supplementary-groups} of our @code{user-account} declaration, as
13566 well as in the @var{groups} of the @code{udev-rules-service} procedure.
13569 (use-modules (gnu packages android) ;for android-udev-rules
13570 (gnu system shadow) ;for user-group
13575 (users (cons (user-account
13577 (supplementary-groups
13578 '("adbusers" ;for adb
13579 "wheel" "netdev" "audio" "video")))))
13582 (cons (udev-rules-service 'android android-udev-rules
13583 #:groups '("adbusers"))
13584 %desktop-services)))
13587 @defvr {Scheme Variable} urandom-seed-service-type
13588 Save some entropy in @code{%random-seed-file} to seed @file{/dev/urandom}
13589 when rebooting. It also tries to seed @file{/dev/urandom} from
13590 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
13594 @defvr {Scheme Variable} %random-seed-file
13595 This is the name of the file where some random bytes are saved by
13596 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
13597 It defaults to @file{/var/lib/random-seed}.
13602 @defvr {Scheme Variable} gpm-service-type
13603 This is the type of the service that runs GPM, the @dfn{general-purpose
13604 mouse daemon}, which provides mouse support to the Linux console. GPM
13605 allows users to use the mouse in the console, notably to select, copy,
13608 The value for services of this type must be a @code{gpm-configuration}
13609 (see below). This service is not part of @code{%base-services}.
13612 @deftp {Data Type} gpm-configuration
13613 Data type representing the configuration of GPM.
13616 @item @code{options} (default: @code{%default-gpm-options})
13617 Command-line options passed to @command{gpm}. The default set of
13618 options instruct @command{gpm} to listen to mouse events on
13619 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
13622 @item @code{gpm} (default: @code{gpm})
13623 The GPM package to use.
13628 @anchor{guix-publish-service-type}
13629 @deffn {Scheme Variable} guix-publish-service-type
13630 This is the service type for @command{guix publish} (@pxref{Invoking
13631 guix publish}). Its value must be a @code{guix-publish-configuration}
13632 object, as described below.
13634 This assumes that @file{/etc/guix} already contains a signing key pair as
13635 created by @command{guix archive --generate-key} (@pxref{Invoking guix
13636 archive}). If that is not the case, the service will fail to start.
13639 @deftp {Data Type} guix-publish-configuration
13640 Data type representing the configuration of the @code{guix publish}
13644 @item @code{guix} (default: @code{guix})
13645 The Guix package to use.
13647 @item @code{port} (default: @code{80})
13648 The TCP port to listen for connections.
13650 @item @code{host} (default: @code{"localhost"})
13651 The host (and thus, network interface) to listen to. Use
13652 @code{"0.0.0.0"} to listen on all the network interfaces.
13654 @item @code{compression} (default: @code{'(("gzip" 3))})
13655 This is a list of compression method/level tuple used when compressing
13656 substitutes. For example, to compress all substitutes with @emph{both} lzip
13657 at level 7 and gzip at level 9, write:
13660 '(("lzip" 7) ("gzip" 9))
13663 Level 9 achieves the best compression ratio at the expense of increased CPU
13664 usage, whereas level 1 achieves fast compression.
13666 An empty list disables compression altogether.
13668 @item @code{nar-path} (default: @code{"nar"})
13669 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
13670 publish, @option{--nar-path}}, for details.
13672 @item @code{cache} (default: @code{#f})
13673 When it is @code{#f}, disable caching and instead generate archives on
13674 demand. Otherwise, this should be the name of a directory---e.g.,
13675 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
13676 archives and meta-data ready to be sent. @xref{Invoking guix publish,
13677 @option{--cache}}, for more information on the tradeoffs involved.
13679 @item @code{workers} (default: @code{#f})
13680 When it is an integer, this is the number of worker threads used for
13681 caching; when @code{#f}, the number of processors is used.
13682 @xref{Invoking guix publish, @option{--workers}}, for more information.
13684 @item @code{ttl} (default: @code{#f})
13685 When it is an integer, this denotes the @dfn{time-to-live} in seconds
13686 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
13687 for more information.
13691 @anchor{rngd-service}
13692 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
13693 [#:device "/dev/hwrng"]
13694 Return a service that runs the @command{rngd} program from @var{rng-tools}
13695 to add @var{device} to the kernel's entropy pool. The service will fail if
13696 @var{device} does not exist.
13699 @anchor{pam-limits-service}
13700 @cindex session limits
13705 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
13707 Return a service that installs a configuration file for the
13708 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
13709 @code{pam_limits} module}. The procedure optionally takes a list of
13710 @code{pam-limits-entry} values, which can be used to specify
13711 @code{ulimit} limits and nice priority limits to user sessions.
13713 The following limits definition sets two hard and soft limits for all
13714 login sessions of users in the @code{realtime} group:
13717 (pam-limits-service
13719 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
13720 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
13723 The first entry increases the maximum realtime priority for
13724 non-privileged processes; the second entry lifts any restriction of the
13725 maximum address space that can be locked in memory. These settings are
13726 commonly used for real-time audio systems.
13729 @node Scheduled Job Execution
13730 @subsection Scheduled Job Execution
13734 @cindex scheduling jobs
13735 The @code{(gnu services mcron)} module provides an interface to
13736 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
13737 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
13738 Unix @command{cron} daemon; the main difference is that it is
13739 implemented in Guile Scheme, which provides a lot of flexibility when
13740 specifying the scheduling of jobs and their actions.
13742 The example below defines an operating system that runs the
13743 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
13744 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
13745 well as the @command{mkid} command on behalf of an unprivileged user
13746 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
13747 gexps to introduce job definitions that are passed to mcron
13748 (@pxref{G-Expressions}).
13751 (use-modules (guix) (gnu) (gnu services mcron))
13752 (use-package-modules base idutils)
13754 (define updatedb-job
13755 ;; Run 'updatedb' at 3AM every day. Here we write the
13756 ;; job's action as a Scheme procedure.
13757 #~(job '(next-hour '(3))
13759 (execl (string-append #$findutils "/bin/updatedb")
13761 "--prunepaths=/tmp /var/tmp /gnu/store"))))
13763 (define garbage-collector-job
13764 ;; Collect garbage 5 minutes after midnight every day.
13765 ;; The job's action is a shell command.
13766 #~(job "5 0 * * *" ;Vixie cron syntax
13769 (define idutils-job
13770 ;; Update the index database as user "charlie" at 12:15PM
13771 ;; and 19:15PM. This runs from the user's home directory.
13772 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
13773 (string-append #$idutils "/bin/mkid src")
13778 (services (cons (service mcron-service-type
13779 (mcron-configuration
13780 (jobs (list garbage-collector-job
13786 For more complex jobs defined in Scheme where you need control over the top
13787 level, for instance to introduce a @code{use-modules} form, you can move your
13788 code to a separate program using the @code{program-file} procedure of the
13789 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
13793 (define %battery-alert-job
13794 ;; Beep when the battery percentage falls below %MIN-LEVEL.
13796 '(next-minute (range 0 60 1))
13798 "battery-alert.scm"
13799 (with-imported-modules (source-module-closure
13800 '((guix build utils)))
13802 (define %min-level 20)
13803 (use-modules (guix build utils)
13806 (ice-9 textual-ports)
13808 (setenv "LC_ALL" "C") ;ensure English output
13809 (and-let* ((input-pipe (open-pipe*
13811 #$(file-append acpi "/bin/acpi")))
13812 (output (get-string-all input-pipe))
13813 (m (string-match "Discharging, ([0-9]+)%" output))
13814 (level (string->number (match:substring m 1)))
13815 ((< level %min-level)))
13816 (format #t "warning: Battery level is low (~a%)~%" level)
13817 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
13820 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
13821 for more information on mcron job specifications. Below is the
13822 reference of the mcron service.
13824 On a running system, you can use the @code{schedule} action of the service to
13825 visualize the mcron jobs that will be executed next:
13828 # herd schedule mcron
13832 The example above lists the next five tasks that will be executed, but you can
13833 also specify the number of tasks to display:
13836 # herd schedule mcron 10
13839 @defvr {Scheme Variable} mcron-service-type
13840 This is the type of the @code{mcron} service, whose value is an
13841 @code{mcron-configuration} object.
13843 This service type can be the target of a service extension that provides
13844 it additional job specifications (@pxref{Service Composition}). In
13845 other words, it is possible to define services that provide additional
13849 @deftp {Data Type} mcron-configuration
13850 Data type representing the configuration of mcron.
13853 @item @code{mcron} (default: @var{mcron})
13854 The mcron package to use.
13857 This is a list of gexps (@pxref{G-Expressions}), where each gexp
13858 corresponds to an mcron job specification (@pxref{Syntax, mcron job
13859 specifications,, mcron, GNU@tie{}mcron}).
13865 @subsection Log Rotation
13868 @cindex log rotation
13870 Log files such as those found in @file{/var/log} tend to grow endlessly,
13871 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
13872 their contents in separate files, possibly compressed. The @code{(gnu
13873 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
13874 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
13876 This service is part of @code{%base-services}, and thus enabled by
13877 default, with the default settings, for commonly encountered log files.
13878 The example below shows how to extend it with an additional
13879 @dfn{rotation}, should you need to do that (usually, services that
13880 produce log files already take care of that):
13883 (use-modules (guix) (gnu))
13884 (use-service-modules admin)
13886 (define my-log-files
13887 ;; Log files that I want to rotate.
13888 '("/var/log/something.log" "/var/log/another.log"))
13892 (services (cons (simple-service 'rotate-my-stuff
13893 rottlog-service-type
13894 (list (log-rotation
13896 (files my-log-files))))
13900 @defvr {Scheme Variable} rottlog-service-type
13901 This is the type of the Rottlog service, whose value is a
13902 @code{rottlog-configuration} object.
13904 Other services can extend this one with new @code{log-rotation} objects
13905 (see below), thereby augmenting the set of files to be rotated.
13907 This service type can define mcron jobs (@pxref{Scheduled Job
13908 Execution}) to run the rottlog service.
13911 @deftp {Data Type} rottlog-configuration
13912 Data type representing the configuration of rottlog.
13915 @item @code{rottlog} (default: @code{rottlog})
13916 The Rottlog package to use.
13918 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
13919 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
13920 rottlog, GNU Rot[t]log Manual}).
13922 @item @code{rotations} (default: @code{%default-rotations})
13923 A list of @code{log-rotation} objects as defined below.
13926 This is a list of gexps where each gexp corresponds to an mcron job
13927 specification (@pxref{Scheduled Job Execution}).
13931 @deftp {Data Type} log-rotation
13932 Data type representing the rotation of a group of log files.
13934 Taking an example from the Rottlog manual (@pxref{Period Related File
13935 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
13941 (files '("/var/log/apache/*"))
13942 (options '("storedir apache-archives"
13948 The list of fields is as follows:
13951 @item @code{frequency} (default: @code{'weekly})
13952 The log rotation frequency, a symbol.
13955 The list of files or file glob patterns to rotate.
13957 @item @code{options} (default: @code{'()})
13958 The list of rottlog options for this rotation (@pxref{Configuration
13959 parameters,,, rottlog, GNU Rot[t]lg Manual}).
13961 @item @code{post-rotate} (default: @code{#f})
13962 Either @code{#f} or a gexp to execute once the rotation has completed.
13966 @defvr {Scheme Variable} %default-rotations
13967 Specifies weekly rotation of @code{%rotated-files} and of
13968 @file{/var/log/guix-daemon.log}.
13971 @defvr {Scheme Variable} %rotated-files
13972 The list of syslog-controlled files to be rotated. By default it is:
13973 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
13974 "/var/log/maillog")}.
13977 @node Networking Services
13978 @subsection Networking Services
13980 The @code{(gnu services networking)} module provides services to configure
13981 the network interface.
13983 @cindex DHCP, networking service
13984 @defvr {Scheme Variable} dhcp-client-service-type
13985 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
13986 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
13987 is the DHCP client package to use, @code{isc-dhcp} by default.
13990 @deffn {Scheme Procedure} dhcpd-service-type
13991 This type defines a service that runs a DHCP daemon. To create a
13992 service of this type, you must supply a @code{<dhcpd-configuration>}.
13996 (service dhcpd-service-type
13997 (dhcpd-configuration
13998 (config-file (local-file "my-dhcpd.conf"))
13999 (interfaces '("enp0s25"))))
14003 @deftp {Data Type} dhcpd-configuration
14005 @item @code{package} (default: @code{isc-dhcp})
14006 The package that provides the DHCP daemon. This package is expected to
14007 provide the daemon at @file{sbin/dhcpd} relative to its output
14008 directory. The default package is the
14009 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
14010 @item @code{config-file} (default: @code{#f})
14011 The configuration file to use. This is required. It will be passed to
14012 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
14013 object (@pxref{G-Expressions, file-like objects}). See @code{man
14014 dhcpd.conf} for details on the configuration file syntax.
14015 @item @code{version} (default: @code{"4"})
14016 The DHCP version to use. The ISC DHCP server supports the values ``4'',
14017 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
14018 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
14020 @item @code{run-directory} (default: @code{"/run/dhcpd"})
14021 The run directory to use. At service activation time, this directory
14022 will be created if it does not exist.
14023 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
14024 The PID file to use. This corresponds to the @code{-pf} option of
14025 @code{dhcpd}. See @code{man dhcpd} for details.
14026 @item @code{interfaces} (default: @code{'()})
14027 The names of the network interfaces on which dhcpd should listen for
14028 broadcasts. If this list is not empty, then its elements (which must be
14029 strings) will be appended to the @code{dhcpd} invocation when starting
14030 the daemon. It may not be necessary to explicitly specify any
14031 interfaces here; see @code{man dhcpd} for details.
14035 @defvr {Scheme Variable} static-networking-service-type
14036 This is the type for statically-configured network interfaces.
14037 @c TODO Document <static-networking> data structures.
14040 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
14041 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
14042 [#:requirement @code{'(udev)}]
14043 Return a service that starts @var{interface} with address @var{ip}. If
14044 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
14045 it must be a string specifying the default network gateway. @var{requirement}
14046 can be used to declare a dependency on another service before configuring the
14049 This procedure can be called several times, one for each network
14050 interface of interest. Behind the scenes what it does is extend
14051 @code{static-networking-service-type} with additional network interfaces
14057 (static-networking-service "eno1" "192.168.1.82"
14058 #:gateway "192.168.1.2"
14059 #:name-servers '("192.168.1.2"))
14066 @cindex network management
14067 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
14068 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
14069 management daemon that aims to simplify wired and wireless networking.
14071 This service adds the @var{wicd} package to the global profile, providing
14072 several commands to interact with the daemon and configure networking:
14073 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
14074 and @command{wicd-curses} user interfaces.
14077 @cindex ModemManager
14079 @defvr {Scheme Variable} modem-manager-service-type
14080 This is the service type for the
14081 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
14082 service. The value for this service type is a
14083 @code{modem-manager-configuration} record.
14085 This service is part of @code{%desktop-services} (@pxref{Desktop
14089 @deftp {Data Type} modem-manager-configuration
14090 Data type representing the configuration of ModemManager.
14093 @item @code{modem-manager} (default: @code{modem-manager})
14094 The ModemManager package to use.
14099 @cindex USB_ModeSwitch
14100 @cindex Modeswitching
14102 @defvr {Scheme Variable} usb-modeswitch-service-type
14103 This is the service type for the
14104 @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch} service. The
14105 value for this service type is a @code{usb-modeswitch-configuration} record.
14107 When plugged in, some USB modems (and other USB devices) initially present
14108 themselves as a read-only storage medium and not as a modem. They need to be
14109 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
14110 installs udev rules to automatically modeswitch these devices when they are
14113 This service is part of @code{%desktop-services} (@pxref{Desktop
14117 @deftp {Data Type} usb-modeswitch-configuration
14118 Data type representing the configuration of USB_ModeSwitch.
14121 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
14122 The USB_ModeSwitch package providing the binaries for modeswitching.
14124 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
14125 The package providing the device data and udev rules file used by
14128 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
14129 Which config file to use for the USB_ModeSwitch dispatcher. By default the
14130 config file shipped with USB_ModeSwitch is used which disables logging to
14131 @file{/var/log} among other default settings. If set to @code{#f}, no config
14137 @cindex NetworkManager
14139 @defvr {Scheme Variable} network-manager-service-type
14140 This is the service type for the
14141 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
14142 service. The value for this service type is a
14143 @code{network-manager-configuration} record.
14145 This service is part of @code{%desktop-services} (@pxref{Desktop
14149 @deftp {Data Type} network-manager-configuration
14150 Data type representing the configuration of NetworkManager.
14153 @item @code{network-manager} (default: @code{network-manager})
14154 The NetworkManager package to use.
14156 @item @code{dns} (default: @code{"default"})
14157 Processing mode for DNS, which affects how NetworkManager uses the
14158 @code{resolv.conf} configuration file.
14162 NetworkManager will update @code{resolv.conf} to reflect the nameservers
14163 provided by currently active connections.
14166 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
14167 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
14168 then update @code{resolv.conf} to point to the local nameserver.
14170 With this setting, you can share your network connection. For example when
14171 you want to share your network connection to another laptop @i{via} an
14172 Ethernet cable, you can open @command{nm-connection-editor} and configure the
14173 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
14174 and reestablish the connection (or reboot).
14176 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
14177 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
14178 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
14179 browser on your host system, or connect to the VM @i{via} SSH
14180 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
14181 host-to-guest connection, run this command once:
14184 nmcli connection add type tun \
14185 connection.interface-name tap0 \
14186 tun.mode tap tun.owner $(id -u) \
14187 ipv4.method shared \
14188 ipv4.addresses 172.28.112.1/24
14191 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
14192 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
14193 @command{qemu-system-...}.
14196 NetworkManager will not modify @code{resolv.conf}.
14199 @item @code{vpn-plugins} (default: @code{'()})
14200 This is the list of available plugins for virtual private networks
14201 (VPNs). An example of this is the @code{network-manager-openvpn}
14202 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
14208 @deffn {Scheme Variable} connman-service-type
14209 This is the service type to run @url{https://01.org/connman,Connman},
14210 a network connection manager.
14212 Its value must be an
14213 @code{connman-configuration} record as in this example:
14216 (service connman-service-type
14217 (connman-configuration
14218 (disable-vpn? #t)))
14221 See below for details about @code{connman-configuration}.
14224 @deftp {Data Type} connman-configuration
14225 Data Type representing the configuration of connman.
14228 @item @code{connman} (default: @var{connman})
14229 The connman package to use.
14231 @item @code{disable-vpn?} (default: @code{#f})
14232 When true, disable connman's vpn plugin.
14236 @cindex WPA Supplicant
14237 @defvr {Scheme Variable} wpa-supplicant-service-type
14238 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
14239 supplicant}, an authentication daemon required to authenticate against
14240 encrypted WiFi or ethernet networks.
14243 @deftp {Data Type} wpa-supplicant-configuration
14244 Data type representing the configuration of WPA Supplicant.
14246 It takes the following parameters:
14249 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
14250 The WPA Supplicant package to use.
14252 @item @code{requirement} (default: @code{'(user-processes dbus-system loopback syslogd)}
14253 List of services that should be started before WPA Supplicant starts.
14255 @item @code{dbus?} (default: @code{#t})
14256 Whether to listen for requests on D-Bus.
14258 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
14259 Where to store the PID file.
14261 @item @code{interface} (default: @code{#f})
14262 If this is set, it must specify the name of a network interface that
14263 WPA supplicant will control.
14265 @item @code{config-file} (default: @code{#f})
14266 Optional configuration file to use.
14268 @item @code{extra-options} (default: @code{'()})
14269 List of additional command-line arguments to pass to the daemon.
14273 @cindex hostapd service, for Wi-Fi access points
14274 @cindex Wi-Fi access points, hostapd service
14275 @defvr {Scheme Variable} hostapd-service-type
14276 This is the service type to run the @uref{https://w1.fi/hostapd/,
14277 hostapd} daemon to set up WiFi (IEEE 802.11) access points and
14278 authentication servers. Its associated value must be a
14279 @code{hostapd-configuration} as shown below:
14282 ;; Use wlan1 to run the access point for "My Network".
14283 (service hostapd-service-type
14284 (hostapd-configuration
14285 (interface "wlan1")
14286 (ssid "My Network")
14291 @deftp {Data Type} hostapd-configuration
14292 This data type represents the configuration of the hostapd service, with
14293 the following fields:
14296 @item @code{package} (default: @code{hostapd})
14297 The hostapd package to use.
14299 @item @code{interface} (default: @code{"wlan0"})
14300 The network interface to run the WiFi access point.
14303 The SSID (@dfn{service set identifier}), a string that identifies this
14306 @item @code{broadcast-ssid?} (default: @code{#t})
14307 Whether to broadcast this SSID.
14309 @item @code{channel} (default: @code{1})
14310 The WiFi channel to use.
14312 @item @code{driver} (default: @code{"nl80211"})
14313 The driver interface type. @code{"nl80211"} is used with all Linux
14314 mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
14315 RADIUS server that does # not control any wireless/wired driver.
14317 @item @code{extra-settings} (default: @code{""})
14318 Extra settings to append as-is to the hostapd configuration file. See
14319 @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
14320 configuration file reference.
14324 @defvr {Scheme Variable} simulated-wifi-service-type
14325 This is the type of a service to simulate WiFi networking, which can be
14326 useful in virtual machines for testing purposes. The service loads the
14328 @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
14329 @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
14330 network that can be seen on @code{wlan0}, by default.
14332 The service's value is a @code{hostapd-configuration} record.
14336 @defvr {Scheme Variable} iptables-service-type
14337 This is the service type to set up an iptables configuration. iptables is a
14338 packet filtering framework supported by the Linux kernel. This service
14339 supports configuring iptables for both IPv4 and IPv6. A simple example
14340 configuration rejecting all incoming connections except those to the ssh port
14344 (service iptables-service-type
14345 (iptables-configuration
14346 (ipv4-rules (plain-file "iptables.rules" "*filter
14350 -A INPUT -p tcp --dport 22 -j ACCEPT
14351 -A INPUT -j REJECT --reject-with icmp-port-unreachable
14354 (ipv6-rules (plain-file "ip6tables.rules" "*filter
14358 -A INPUT -p tcp --dport 22 -j ACCEPT
14359 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
14365 @deftp {Data Type} iptables-configuration
14366 The data type representing the configuration of iptables.
14369 @item @code{iptables} (default: @code{iptables})
14370 The iptables package that provides @code{iptables-restore} and
14371 @code{ip6tables-restore}.
14372 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
14373 The iptables rules to use. It will be passed to @code{iptables-restore}.
14374 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
14376 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
14377 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
14378 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
14384 @defvr {Scheme Variable} nftables-service-type
14385 This is the service type to set up a nftables configuration. nftables is a
14386 netfilter project that aims to replace the existing iptables, ip6tables,
14387 arptables and ebtables framework. It provides a new packet filtering
14388 framework, a new user-space utility @command{nft}, and a compatibility layer
14389 for iptables. This service comes with a default ruleset
14390 @code{%default-nftables-ruleset} that rejecting all incomming connections
14391 except those to the ssh port 22. To use it, simply write:
14394 (service nftables-service-type)
14398 @deftp {Data Type} nftables-configuration
14399 The data type representing the configuration of nftables.
14402 @item @code{package} (default: @code{nftables})
14403 The nftables package that provides @command{nft}.
14404 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
14405 The nftables ruleset to use. This may be any ``file-like'' object
14406 (@pxref{G-Expressions, file-like objects}).
14410 @cindex NTP (Network Time Protocol), service
14411 @cindex ntpd, service for the Network Time Protocol daemon
14412 @cindex real time clock
14413 @defvr {Scheme Variable} ntp-service-type
14414 This is the type of the service running the @uref{https://www.ntp.org,
14415 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
14416 system clock synchronized with that of the specified NTP servers.
14418 The value of this service is an @code{ntpd-configuration} object, as described
14422 @deftp {Data Type} ntp-configuration
14423 This is the data type for the NTP service configuration.
14426 @item @code{servers} (default: @code{%ntp-servers})
14427 This is the list of servers (@code{<ntp-server>} records) with which
14428 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
14431 @item @code{allow-large-adjustment?} (default: @code{#t})
14432 This determines whether @command{ntpd} is allowed to make an initial
14433 adjustment of more than 1,000 seconds.
14435 @item @code{ntp} (default: @code{ntp})
14436 The NTP package to use.
14440 @defvr {Scheme Variable} %ntp-servers
14441 List of host names used as the default NTP servers. These are servers of the
14442 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
14445 @deftp {Data Type} ntp-server
14446 The data type representing the configuration of a NTP server.
14449 @item @code{type} (default: @code{'server})
14450 The type of the NTP server, given as a symbol. One of @code{'pool},
14451 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
14453 @item @code{address}
14454 The address of the server, as a string.
14456 @item @code{options}
14457 NTPD options to use with that specific server, given as a list of option names
14458 and/or of option names and values tuples. The following example define a server
14459 to use with the options @option{iburst} and @option{prefer}, as well as
14460 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
14465 (address "some.ntp.server.org")
14466 (options `(iburst (version 3) (maxpoll 16) prefer))))
14472 @deffn {Scheme Procedure} openntpd-service-type
14473 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
14474 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
14475 clock synchronized with that of the given servers.
14479 openntpd-service-type
14480 (openntpd-configuration
14481 (listen-on '("127.0.0.1" "::1"))
14482 (sensor '("udcf0 correction 70000"))
14483 (constraint-from '("www.gnu.org"))
14484 (constraints-from '("https://www.google.com/"))
14485 (allow-large-adjustment? #t)))
14490 @defvr {Scheme Variable} %openntpd-servers
14491 This variable is a list of the server addresses defined in
14492 @code{%ntp-servers}.
14495 @deftp {Data Type} openntpd-configuration
14497 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
14498 The openntpd executable to use.
14499 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
14500 A list of local IP addresses or hostnames the ntpd daemon should listen on.
14501 @item @code{query-from} (default: @code{'()})
14502 A list of local IP address the ntpd daemon should use for outgoing queries.
14503 @item @code{sensor} (default: @code{'()})
14504 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
14505 will listen to each sensor that actually exists and ignore non-existent ones.
14506 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
14508 @item @code{server} (default: @code{'()})
14509 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
14510 @item @code{servers} (default: @code{%openntp-servers})
14511 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
14512 @item @code{constraint-from} (default: @code{'()})
14513 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
14514 This time information is not used for precision but acts as an authenticated
14515 constraint, thereby reducing the impact of unauthenticated NTP
14516 man-in-the-middle attacks.
14517 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
14519 @item @code{constraints-from} (default: @code{'()})
14520 As with constraint from, specify a list of URLs, IP addresses or hostnames of
14521 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
14522 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
14523 @item @code{allow-large-adjustment?} (default: @code{#f})
14524 Determines if @code{ntpd} is allowed to make an initial adjustment of more
14530 @deffn {Scheme variable} inetd-service-type
14531 This service runs the @command{inetd} (@pxref{inetd invocation,,,
14532 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
14533 connections on internet sockets, and lazily starts the specified server
14534 program when a connection is made on one of these sockets.
14536 The value of this service is an @code{inetd-configuration} object. The
14537 following example configures the @command{inetd} daemon to provide the
14538 built-in @command{echo} service, as well as an smtp service which
14539 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
14540 gateway @code{hostname}:
14545 (inetd-configuration
14549 (socket-type 'stream)
14556 (socket-type 'stream)
14560 (program (file-append openssh "/bin/ssh"))
14562 '("ssh" "-qT" "-i" "/path/to/ssh_key"
14563 "-W" "smtp-server:25" "user@@hostname")))))))
14566 See below for more details about @code{inetd-configuration}.
14569 @deftp {Data Type} inetd-configuration
14570 Data type representing the configuration of @command{inetd}.
14573 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
14574 The @command{inetd} executable to use.
14576 @item @code{entries} (default: @code{'()})
14577 A list of @command{inetd} service entries. Each entry should be created
14578 by the @code{inetd-entry} constructor.
14582 @deftp {Data Type} inetd-entry
14583 Data type representing an entry in the @command{inetd} configuration.
14584 Each entry corresponds to a socket where @command{inetd} will listen for
14588 @item @code{node} (default: @code{#f})
14589 Optional string, a comma-separated list of local addresses
14590 @command{inetd} should use when listening for this service.
14591 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
14592 description of all options.
14594 A string, the name must correspond to an entry in @code{/etc/services}.
14595 @item @code{socket-type}
14596 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
14598 @item @code{protocol}
14599 A string, must correspond to an entry in @code{/etc/protocols}.
14600 @item @code{wait?} (default: @code{#t})
14601 Whether @command{inetd} should wait for the server to exit before
14602 listening to new service requests.
14604 A string containing the user (and, optionally, group) name of the user
14605 as whom the server should run. The group name can be specified in a
14606 suffix, separated by a colon or period, i.e.@: @code{"user"},
14607 @code{"user:group"} or @code{"user.group"}.
14608 @item @code{program} (default: @code{"internal"})
14609 The server program which will serve the requests, or @code{"internal"}
14610 if @command{inetd} should use a built-in service.
14611 @item @code{arguments} (default: @code{'()})
14612 A list strings or file-like objects, which are the server program's
14613 arguments, starting with the zeroth argument, i.e.@: the name of the
14614 program itself. For @command{inetd}'s internal services, this entry
14615 must be @code{'()} or @code{'("internal")}.
14618 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
14619 detailed discussion of each configuration field.
14623 @defvr {Scheme Variable} tor-service-type
14624 This is the type for a service that runs the @uref{https://torproject.org,
14625 Tor} anonymous networking daemon. The service is configured using a
14626 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
14627 @code{tor} unprivileged user, which is a member of the @code{tor} group.
14631 @deftp {Data Type} tor-configuration
14633 @item @code{tor} (default: @code{tor})
14634 The package that provides the Tor daemon. This package is expected to provide
14635 the daemon at @file{bin/tor} relative to its output directory. The default
14636 package is the @uref{https://www.torproject.org, Tor Project's}
14639 @item @code{config-file} (default: @code{(plain-file "empty" "")})
14640 The configuration file to use. It will be appended to a default configuration
14641 file, and the final configuration file will be passed to @code{tor} via its
14642 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
14643 file-like objects}). See @code{man tor} for details on the configuration file
14646 @item @code{hidden-services} (default: @code{'()})
14647 The list of @code{<hidden-service>} records to use. For any hidden service
14648 you include in this list, appropriate configuration to enable the hidden
14649 service will be automatically added to the default configuration file. You
14650 may conveniently create @code{<hidden-service>} records using the
14651 @code{tor-hidden-service} procedure described below.
14653 @item @code{socks-socket-type} (default: @code{'tcp})
14654 The default socket type that Tor should use for its SOCKS socket. This must
14655 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
14656 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
14657 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
14658 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
14661 If you want to customize the SOCKS socket in more detail, leave
14662 @code{socks-socket-type} at its default value of @code{'tcp} and use
14663 @code{config-file} to override the default by providing your own
14664 @code{SocksPort} option.
14668 @cindex hidden service
14669 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
14670 Define a new Tor @dfn{hidden service} called @var{name} and implementing
14671 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
14674 '((22 "127.0.0.1:22")
14675 (80 "127.0.0.1:8080"))
14678 In this example, port 22 of the hidden service is mapped to local port 22, and
14679 port 80 is mapped to local port 8080.
14681 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
14682 the @file{hostname} file contains the @code{.onion} host name for the hidden
14685 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
14686 project's documentation} for more information.
14689 The @code{(gnu services rsync)} module provides the following services:
14691 You might want an rsync daemon if you have files that you want available
14692 so anyone (or just yourself) can download existing files or upload new
14695 @deffn {Scheme Variable} rsync-service-type
14696 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
14697 The value for this service type is a
14698 @command{rsync-configuration} record as in this example:
14701 (service rsync-service-type)
14704 See below for details about @code{rsync-configuration}.
14707 @deftp {Data Type} rsync-configuration
14708 Data type representing the configuration for @code{rsync-service}.
14711 @item @code{package} (default: @var{rsync})
14712 @code{rsync} package to use.
14714 @item @code{port-number} (default: @code{873})
14715 TCP port on which @command{rsync} listens for incoming connections. If port
14716 is less than @code{1024} @command{rsync} needs to be started as the
14717 @code{root} user and group.
14719 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
14720 Name of the file where @command{rsync} writes its PID.
14722 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
14723 Name of the file where @command{rsync} writes its lock file.
14725 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
14726 Name of the file where @command{rsync} writes its log file.
14728 @item @code{use-chroot?} (default: @var{#t})
14729 Whether to use chroot for @command{rsync} shared directory.
14731 @item @code{share-path} (default: @file{/srv/rsync})
14732 Location of the @command{rsync} shared directory.
14734 @item @code{share-comment} (default: @code{"Rsync share"})
14735 Comment of the @command{rsync} shared directory.
14737 @item @code{read-only?} (default: @var{#f})
14738 Read-write permissions to shared directory.
14740 @item @code{timeout} (default: @code{300})
14741 I/O timeout in seconds.
14743 @item @code{user} (default: @var{"root"})
14744 Owner of the @code{rsync} process.
14746 @item @code{group} (default: @var{"root"})
14747 Group of the @code{rsync} process.
14749 @item @code{uid} (default: @var{"rsyncd"})
14750 User name or user ID that file transfers to and from that module should take
14751 place as when the daemon was run as @code{root}.
14753 @item @code{gid} (default: @var{"rsyncd"})
14754 Group name or group ID that will be used when accessing the module.
14759 Furthermore, @code{(gnu services ssh)} provides the following services.
14763 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
14764 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
14765 [#:allow-empty-passwords? #f] [#:root-login? #f] @
14766 [#:syslog-output? #t] [#:x11-forwarding? #t] @
14767 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
14768 [#:public-key-authentication? #t] [#:initialize? #t]
14769 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
14770 @var{host-key} must designate a file containing the host key, and readable
14773 When @var{daemonic?} is true, @command{lshd} will detach from the
14774 controlling terminal and log its output to syslogd, unless one sets
14775 @var{syslog-output?} to false. Obviously, it also makes lsh-service
14776 depend on existence of syslogd service. When @var{pid-file?} is true,
14777 @command{lshd} writes its PID to the file called @var{pid-file}.
14779 When @var{initialize?} is true, automatically create the seed and host key
14780 upon service activation if they do not exist yet. This may take long and
14781 require interaction.
14783 When @var{initialize?} is false, it is up to the user to initialize the
14784 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
14785 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
14786 basics,,, lsh, LSH Manual}).
14788 When @var{interfaces} is empty, lshd listens for connections on all the
14789 network interfaces; otherwise, @var{interfaces} must be a list of host names
14792 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
14793 passwords, and @var{root-login?} specifies whether to accept log-ins as
14796 The other options should be self-descriptive.
14801 @deffn {Scheme Variable} openssh-service-type
14802 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
14803 shell daemon, @command{sshd}. Its value must be an
14804 @code{openssh-configuration} record as in this example:
14807 (service openssh-service-type
14808 (openssh-configuration
14809 (x11-forwarding? #t)
14810 (permit-root-login 'without-password)
14812 `(("alice" ,(local-file "alice.pub"))
14813 ("bob" ,(local-file "bob.pub"))))))
14816 See below for details about @code{openssh-configuration}.
14818 This service can be extended with extra authorized keys, as in this
14822 (service-extension openssh-service-type
14823 (const `(("charlie"
14824 ,(local-file "charlie.pub")))))
14828 @deftp {Data Type} openssh-configuration
14829 This is the configuration record for OpenSSH's @command{sshd}.
14832 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
14833 Name of the file where @command{sshd} writes its PID.
14835 @item @code{port-number} (default: @code{22})
14836 TCP port on which @command{sshd} listens for incoming connections.
14838 @item @code{permit-root-login} (default: @code{#f})
14839 This field determines whether and when to allow logins as root. If
14840 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
14841 If it's the symbol @code{'without-password}, then root logins are
14842 permitted but not with password-based authentication.
14844 @item @code{allow-empty-passwords?} (default: @code{#f})
14845 When true, users with empty passwords may log in. When false, they may
14848 @item @code{password-authentication?} (default: @code{#t})
14849 When true, users may log in with their password. When false, they have
14850 other authentication methods.
14852 @item @code{public-key-authentication?} (default: @code{#t})
14853 When true, users may log in using public key authentication. When
14854 false, users have to use other authentication method.
14856 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
14857 This is used only by protocol version 2.
14859 @item @code{x11-forwarding?} (default: @code{#f})
14860 When true, forwarding of X11 graphical client connections is
14861 enabled---in other words, @command{ssh} options @option{-X} and
14862 @option{-Y} will work.
14864 @item @code{allow-agent-forwarding?} (default: @code{#t})
14865 Whether to allow agent forwarding.
14867 @item @code{allow-tcp-forwarding?} (default: @code{#t})
14868 Whether to allow TCP forwarding.
14870 @item @code{gateway-ports?} (default: @code{#f})
14871 Whether to allow gateway ports.
14873 @item @code{challenge-response-authentication?} (default: @code{#f})
14874 Specifies whether challenge response authentication is allowed (e.g.@: via
14877 @item @code{use-pam?} (default: @code{#t})
14878 Enables the Pluggable Authentication Module interface. If set to
14879 @code{#t}, this will enable PAM authentication using
14880 @code{challenge-response-authentication?} and
14881 @code{password-authentication?}, in addition to PAM account and session
14882 module processing for all authentication types.
14884 Because PAM challenge response authentication usually serves an
14885 equivalent role to password authentication, you should disable either
14886 @code{challenge-response-authentication?} or
14887 @code{password-authentication?}.
14889 @item @code{print-last-log?} (default: @code{#t})
14890 Specifies whether @command{sshd} should print the date and time of the
14891 last user login when a user logs in interactively.
14893 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
14894 Configures external subsystems (e.g.@: file transfer daemon).
14896 This is a list of two-element lists, each of which containing the
14897 subsystem name and a command (with optional arguments) to execute upon
14900 The command @command{internal-sftp} implements an in-process SFTP
14901 server. Alternatively, one can specify the @command{sftp-server} command:
14903 (service openssh-service-type
14904 (openssh-configuration
14906 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
14909 @item @code{accepted-environment} (default: @code{'()})
14910 List of strings describing which environment variables may be exported.
14912 Each string gets on its own line. See the @code{AcceptEnv} option in
14913 @code{man sshd_config}.
14915 This example allows ssh-clients to export the @env{COLORTERM} variable.
14916 It is set by terminal emulators, which support colors. You can use it in
14917 your shell's resource file to enable colors for the prompt and commands
14918 if this variable is set.
14921 (service openssh-service-type
14922 (openssh-configuration
14923 (accepted-environment '("COLORTERM"))))
14926 @item @code{authorized-keys} (default: @code{'()})
14927 @cindex authorized keys, SSH
14928 @cindex SSH authorized keys
14929 This is the list of authorized keys. Each element of the list is a user
14930 name followed by one or more file-like objects that represent SSH public
14934 (openssh-configuration
14936 `(("rekado" ,(local-file "rekado.pub"))
14937 ("chris" ,(local-file "chris.pub"))
14938 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
14942 registers the specified public keys for user accounts @code{rekado},
14943 @code{chris}, and @code{root}.
14945 Additional authorized keys can be specified @i{via}
14946 @code{service-extension}.
14948 Note that this does @emph{not} interfere with the use of
14949 @file{~/.ssh/authorized_keys}.
14951 @item @code{log-level} (default: @code{'info})
14952 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
14953 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
14954 page for @file{sshd_config} for the full list of level names.
14956 @item @code{extra-content} (default: @code{""})
14957 This field can be used to append arbitrary text to the configuration file. It
14958 is especially useful for elaborate configurations that cannot be expressed
14959 otherwise. This configuration, for example, would generally disable root
14960 logins, but permit them from one specific IP address:
14963 (openssh-configuration
14965 Match Address 192.168.0.1
14966 PermitRootLogin yes"))
14972 @deffn {Scheme Procedure} dropbear-service [@var{config}]
14973 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
14974 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
14977 For example, to specify a Dropbear service listening on port 1234, add
14978 this call to the operating system's @code{services} field:
14981 (dropbear-service (dropbear-configuration
14982 (port-number 1234)))
14986 @deftp {Data Type} dropbear-configuration
14987 This data type represents the configuration of a Dropbear SSH daemon.
14990 @item @code{dropbear} (default: @var{dropbear})
14991 The Dropbear package to use.
14993 @item @code{port-number} (default: 22)
14994 The TCP port where the daemon waits for incoming connections.
14996 @item @code{syslog-output?} (default: @code{#t})
14997 Whether to enable syslog output.
14999 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
15000 File name of the daemon's PID file.
15002 @item @code{root-login?} (default: @code{#f})
15003 Whether to allow @code{root} logins.
15005 @item @code{allow-empty-passwords?} (default: @code{#f})
15006 Whether to allow empty passwords.
15008 @item @code{password-authentication?} (default: @code{#t})
15009 Whether to enable password-based authentication.
15014 @deffn {Scheme Variable} autossh-service-type
15015 This is the type for the @uref{https://www.harding.motd.ca/autossh,
15016 AutoSSH} program that runs a copy of @command{ssh} and monitors it,
15017 restarting it as necessary should it die or stop passing traffic.
15018 AutoSSH can be run manually from the command-line by passing arguments
15019 to the binary @command{autossh} from the package @code{autossh}, but it
15020 can also be run as a Guix service. This latter use case is documented
15023 AutoSSH can be used to forward local traffic to a remote machine using
15024 an SSH tunnel, and it respects the @file{~/.ssh/config} of the user it
15027 For example, to specify a service running autossh as the user
15028 @code{pino} and forwarding all local connections to port @code{8081} to
15029 @code{remote:8081} using an SSH tunnel, add this call to the operating
15030 system's @code{services} field:
15033 (service autossh-service-type
15034 (autossh-configuration
15036 (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
15040 @deftp {Data Type} autossh-configuration
15041 This data type represents the configuration of an AutoSSH service.
15045 @item @code{user} (default @code{"autossh"})
15046 The user as which the AutoSSH service is to be run.
15047 This assumes that the specified user exists.
15049 @item @code{poll} (default @code{600})
15050 Specifies the connection poll time in seconds.
15052 @item @code{first-poll} (default @code{#f})
15053 Specifies how many seconds AutoSSH waits before the first connection
15054 test. After this first test, polling is resumed at the pace defined in
15055 @code{poll}. When set to @code{#f}, the first poll is not treated
15056 specially and will also use the connection poll specified in
15059 @item @code{gate-time} (default @code{30})
15060 Specifies how many seconds an SSH connection must be active before it is
15061 considered successful.
15063 @item @code{log-level} (default @code{1})
15064 The log level, corresponding to the levels used by syslog---so @code{0}
15065 is the most silent while @code{7} is the chattiest.
15067 @item @code{max-start} (default @code{#f})
15068 The maximum number of times SSH may be (re)started before AutoSSH exits.
15069 When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
15071 @item @code{message} (default @code{""})
15072 The message to append to the echo message sent when testing connections.
15074 @item @code{port} (default @code{"0"})
15075 The ports used for monitoring the connection. When set to @code{"0"},
15076 monitoring is disabled. When set to @code{"@var{n}"} where @var{n} is
15077 a positive integer, ports @var{n} and @var{n}+1 are used for
15078 monitoring the connection, such that port @var{n} is the base
15079 monitoring port and @code{n+1} is the echo port. When set to
15080 @code{"@var{n}:@var{m}"} where @var{n} and @var{m} are positive
15081 integers, the ports @var{n} and @var{n}+1 are used for monitoring the
15082 connection, such that port @var{n} is the base monitoring port and
15083 @var{m} is the echo port.
15085 @item @code{ssh-options} (default @code{'()})
15086 The list of command-line arguments to pass to @command{ssh} when it is
15087 run. Options @option{-f} and @option{-M} are reserved for AutoSSH and
15088 may cause undefined behaviour.
15093 @defvr {Scheme Variable} %facebook-host-aliases
15094 This variable contains a string for use in @file{/etc/hosts}
15095 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
15096 line contains a entry that maps a known server name of the Facebook
15097 on-line service---e.g., @code{www.facebook.com}---to the local
15098 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
15100 This variable is typically used in the @code{hosts-file} field of an
15101 @code{operating-system} declaration (@pxref{operating-system Reference,
15102 @file{/etc/hosts}}):
15105 (use-modules (gnu) (guix))
15108 (host-name "mymachine")
15111 ;; Create a /etc/hosts file with aliases for "localhost"
15112 ;; and "mymachine", as well as for Facebook servers.
15113 (plain-file "hosts"
15114 (string-append (local-host-aliases host-name)
15115 %facebook-host-aliases))))
15118 This mechanism can prevent programs running locally, such as Web
15119 browsers, from accessing Facebook.
15122 The @code{(gnu services avahi)} provides the following definition.
15124 @defvr {Scheme Variable} avahi-service-type
15125 This is the service that runs @command{avahi-daemon}, a system-wide
15126 mDNS/DNS-SD responder that allows for service discovery and
15127 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
15128 Its value must be a @code{zero-configuration} record---see below.
15130 This service extends the name service cache daemon (nscd) so that it can
15131 resolve @code{.local} host names using
15132 @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
15133 Service Switch}, for information on host name resolution.
15135 Additionally, add the @var{avahi} package to the system profile so that
15136 commands such as @command{avahi-browse} are directly usable.
15139 @deftp {Data Type} avahi-configuration
15140 Data type representation the configuration for Avahi.
15144 @item @code{host-name} (default: @code{#f})
15145 If different from @code{#f}, use that as the host name to
15146 publish for this machine; otherwise, use the machine's actual host name.
15148 @item @code{publish?} (default: @code{#t})
15149 When true, allow host names and services to be published (broadcast) over the
15152 @item @code{publish-workstation?} (default: @code{#t})
15153 When true, @command{avahi-daemon} publishes the machine's host name and IP
15154 address via mDNS on the local network. To view the host names published on
15155 your local network, you can run:
15158 avahi-browse _workstation._tcp
15161 @item @code{wide-area?} (default: @code{#f})
15162 When true, DNS-SD over unicast DNS is enabled.
15164 @item @code{ipv4?} (default: @code{#t})
15165 @itemx @code{ipv6?} (default: @code{#t})
15166 These fields determine whether to use IPv4/IPv6 sockets.
15168 @item @code{domains-to-browse} (default: @code{'()})
15169 This is a list of domains to browse.
15173 @deffn {Scheme Variable} openvswitch-service-type
15174 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
15175 service, whose value should be an @code{openvswitch-configuration}
15179 @deftp {Data Type} openvswitch-configuration
15180 Data type representing the configuration of Open vSwitch, a multilayer
15181 virtual switch which is designed to enable massive network automation
15182 through programmatic extension.
15185 @item @code{package} (default: @var{openvswitch})
15186 Package object of the Open vSwitch.
15191 @defvr {Scheme Variable} pagekite-service-type
15192 This is the service type for the @uref{https://pagekite.net, PageKite} service,
15193 a tunneling solution for making localhost servers publicly visible, even from
15194 behind restrictive firewalls or NAT without forwarded ports. The value for
15195 this service type is a @code{pagekite-configuration} record.
15197 Here's an example exposing the local HTTP and SSH daemons:
15200 (service pagekite-service-type
15201 (pagekite-configuration
15202 (kites '("http:@@kitename:localhost:80:@@kitesecret"
15203 "raw/22:@@kitename:localhost:22:@@kitesecret"))
15204 (extra-file "/etc/pagekite.rc")))
15208 @deftp {Data Type} pagekite-configuration
15209 Data type representing the configuration of PageKite.
15212 @item @code{package} (default: @var{pagekite})
15213 Package object of PageKite.
15215 @item @code{kitename} (default: @code{#f})
15216 PageKite name for authenticating to the frontend server.
15218 @item @code{kitesecret} (default: @code{#f})
15219 Shared secret for authenticating to the frontend server. You should probably
15220 put this inside @code{extra-file} instead.
15222 @item @code{frontend} (default: @code{#f})
15223 Connect to the named PageKite frontend server instead of the
15224 @uref{https://pagekite.net,,pagekite.net} service.
15226 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
15227 List of service kites to use. Exposes HTTP on port 80 by default. The format
15228 is @code{proto:kitename:host:port:secret}.
15230 @item @code{extra-file} (default: @code{#f})
15231 Extra configuration file to read, which you are expected to create manually.
15232 Use this to add additional options and manage shared secrets out-of-band.
15238 @subsection X Window
15241 @cindex X Window System
15242 @cindex login manager
15243 Support for the X Window graphical display system---specifically
15244 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
15245 there is no @code{xorg-service} procedure. Instead, the X server is
15246 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
15249 @cindex GNOME, login manager
15250 GDM of course allows users to log in into window managers and desktop
15251 environments other than GNOME; for those using GNOME, GDM is required for
15252 features such as automatic screen locking.
15254 @cindex window manager
15255 To use X11, you must install at least one @dfn{window manager}---for
15256 example the @code{windowmaker} or @code{openbox} packages---preferably
15257 by adding it to the @code{packages} field of your operating system
15258 definition (@pxref{operating-system Reference, system-wide packages}).
15260 @defvr {Scheme Variable} gdm-service-type
15261 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
15262 Desktop Manager} (GDM), a program that manages graphical display servers and
15263 handles graphical user logins. Its value must be a @code{gdm-configuration}
15266 @cindex session types (X11)
15267 @cindex X11 session types
15268 GDM looks for @dfn{session types} described by the @file{.desktop} files in
15269 @file{/run/current-system/profile/share/xsessions} and allows users to choose
15270 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
15271 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
15272 set of packages automatically makes them available at the log-in screen.
15274 In addition, @file{~/.xsession} files are honored. When available,
15275 @file{~/.xsession} must be an executable that starts a window manager
15276 and/or other X clients.
15279 @deftp {Data Type} gdm-configuration
15281 @item @code{auto-login?} (default: @code{#f})
15282 @itemx @code{default-user} (default: @code{#f})
15283 When @code{auto-login?} is false, GDM presents a log-in screen.
15285 When @code{auto-login?} is true, GDM logs in directly as
15286 @code{default-user}.
15288 @item @code{debug?} (default: @code{#f})
15289 When true, GDM writes debug messages to its log.
15291 @item @code{gnome-shell-assets} (default: ...)
15292 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
15294 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
15295 Configuration of the Xorg graphical server.
15297 @item @code{xsession} (default: @code{(xinitrc)})
15298 Script to run before starting a X session.
15300 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
15301 File name of the @code{dbus-daemon} executable.
15303 @item @code{gdm} (default: @code{gdm})
15304 The GDM package to use.
15308 @defvr {Scheme Variable} slim-service-type
15309 This is the type for the SLiM graphical login manager for X11.
15311 Like GDM, SLiM looks for session types described by @file{.desktop} files and
15312 allows users to choose a session from the log-in screen using @kbd{F1}. It
15313 also honors @file{~/.xsession} files.
15315 Unlike GDM, SLiM does not spawn the user session on a different VT after
15316 logging in, which means that you can only start one graphical session. If you
15317 want to be able to run multiple graphical sessions at the same time you have
15318 to add multiple SLiM services to your system services. The following example
15319 shows how to replace the default GDM service with two SLiM services on tty7
15323 (use-modules (gnu services)
15324 (gnu services desktop)
15325 (gnu services xorg)
15326 (srfi srfi-1)) ;for 'remove'
15330 (services (cons* (service slim-service-type (slim-configuration
15333 (service slim-service-type (slim-configuration
15336 (remove (lambda (service)
15337 (eq? (service-kind service) gdm-service-type))
15338 %desktop-services))))
15343 @deftp {Data Type} slim-configuration
15344 Data type representing the configuration of @code{slim-service-type}.
15347 @item @code{allow-empty-passwords?} (default: @code{#t})
15348 Whether to allow logins with empty passwords.
15350 @item @code{auto-login?} (default: @code{#f})
15351 @itemx @code{default-user} (default: @code{""})
15352 When @code{auto-login?} is false, SLiM presents a log-in screen.
15354 When @code{auto-login?} is true, SLiM logs in directly as
15355 @code{default-user}.
15357 @item @code{theme} (default: @code{%default-slim-theme})
15358 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
15359 The graphical theme to use and its name.
15361 @item @code{auto-login-session} (default: @code{#f})
15362 If true, this must be the name of the executable to start as the default
15363 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
15365 If false, a session described by one of the available @file{.desktop}
15366 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
15370 You must install at least one window manager in the system profile or in
15371 your user profile. Failing to do that, if @code{auto-login-session} is
15372 false, you will be unable to log in.
15375 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
15376 Configuration of the Xorg graphical server.
15378 @item @code{display} (default @code{":0"})
15379 The display on which to start the Xorg graphical server.
15381 @item @code{vt} (default @code{"vt7"})
15382 The VT on which to start the Xorg graphical server.
15384 @item @code{xauth} (default: @code{xauth})
15385 The XAuth package to use.
15387 @item @code{shepherd} (default: @code{shepherd})
15388 The Shepherd package used when invoking @command{halt} and
15391 @item @code{sessreg} (default: @code{sessreg})
15392 The sessreg package used in order to register the session.
15394 @item @code{slim} (default: @code{slim})
15395 The SLiM package to use.
15399 @defvr {Scheme Variable} %default-theme
15400 @defvrx {Scheme Variable} %default-theme-name
15401 The default SLiM theme and its name.
15405 @deftp {Data Type} sddm-configuration
15406 This is the data type representing the SDDM service configuration.
15409 @item @code{display-server} (default: "x11")
15410 Select display server to use for the greeter. Valid values are
15411 @samp{"x11"} or @samp{"wayland"}.
15413 @item @code{numlock} (default: "on")
15414 Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
15416 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
15417 Command to run when halting.
15419 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
15420 Command to run when rebooting.
15422 @item @code{theme} (default "maldives")
15423 Theme to use. Default themes provided by SDDM are @samp{"elarun"},
15424 @samp{"maldives"} or @samp{"maya"}.
15426 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
15427 Directory to look for themes.
15429 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
15430 Directory to look for faces.
15432 @item @code{default-path} (default "/run/current-system/profile/bin")
15433 Default PATH to use.
15435 @item @code{minimum-uid} (default: 1000)
15436 Minimum UID displayed in SDDM and allowed for log-in.
15438 @item @code{maximum-uid} (default: 2000)
15439 Maximum UID to display in SDDM.
15441 @item @code{remember-last-user?} (default #t)
15442 Remember last user.
15444 @item @code{remember-last-session?} (default #t)
15445 Remember last session.
15447 @item @code{hide-users} (default "")
15448 Usernames to hide from SDDM greeter.
15450 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
15451 Users with shells listed will be hidden from the SDDM greeter.
15453 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
15454 Script to run before starting a wayland session.
15456 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
15457 Directory to look for desktop files starting wayland sessions.
15459 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
15460 Configuration of the Xorg graphical server.
15462 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
15465 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
15468 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
15469 Script to run after starting xorg-server.
15471 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
15472 Script to run before stopping xorg-server.
15474 @item @code{xsession-command} (default: @code{xinitrc})
15475 Script to run before starting a X session.
15477 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
15478 Directory to look for desktop files starting X sessions.
15480 @item @code{minimum-vt} (default: 7)
15483 @item @code{auto-login-user} (default "")
15484 User to use for auto-login.
15486 @item @code{auto-login-session} (default "")
15487 Desktop file to use for auto-login.
15489 @item @code{relogin?} (default #f)
15490 Relogin after logout.
15495 @cindex login manager
15497 @defvr {Scheme Variable} sddm-service-type
15498 This is the type of the service to run the
15499 @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
15500 must be a @code{sddm-configuration} record (see below).
15502 Here's an example use:
15505 (service sddm-service-type
15506 (sddm-configuration
15507 (auto-login-user "alice")
15508 (auto-login-session "xfce.desktop")))
15512 @deftp {Data Type} sddm-configuration
15513 This data type represents the configuration of the SDDM login manager.
15514 The available fields are:
15517 @item @code{sddm} (default: @code{sddm})
15518 The SDDM package to use.
15520 @item @code{display-server} (default: @code{"x11"})
15521 This must be either @code{"x11"} or @code{"wayland"}.
15523 @c FIXME: Add more fields.
15525 @item @code{auto-login-user} (default: @code{""})
15526 If non-empty, this is the user account under which to log in
15529 @item @code{auto-login-session} (default: @code{""})
15530 If non-empty, this is the @file{.desktop} file name to use as the
15531 auto-login session.
15535 @cindex Xorg, configuration
15536 @deftp {Data Type} xorg-configuration
15537 This data type represents the configuration of the Xorg graphical display
15538 server. Note that there is no Xorg service; instead, the X server is started
15539 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
15540 of these display managers aggregates an @code{xorg-configuration} record.
15543 @item @code{modules} (default: @code{%default-xorg-modules})
15544 This is a list of @dfn{module packages} loaded by the Xorg
15545 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
15547 @item @code{fonts} (default: @code{%default-xorg-fonts})
15548 This is a list of font directories to add to the server's @dfn{font path}.
15550 @item @code{drivers} (default: @code{'()})
15551 This must be either the empty list, in which case Xorg chooses a graphics
15552 driver automatically, or a list of driver names that will be tried in this
15553 order---e.g., @code{("modesetting" "vesa")}.
15555 @item @code{resolutions} (default: @code{'()})
15556 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
15557 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
15560 @cindex keyboard layout, for Xorg
15561 @cindex keymap, for Xorg
15562 @item @code{keyboard-layout} (default: @code{#f})
15563 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
15564 English (``qwerty'') for a 105-key PC keyboard.
15566 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
15567 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
15568 information on how to specify the keyboard layout.
15570 @item @code{extra-config} (default: @code{'()})
15571 This is a list of strings or objects appended to the configuration file. It
15572 is used to pass extra text to be added verbatim to the configuration file.
15574 @item @code{server} (default: @code{xorg-server})
15575 This is the package providing the Xorg server.
15577 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
15578 This is the list of command-line arguments to pass to the X server. The
15579 default is @code{-nolisten tcp}.
15583 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
15584 [@var{login-manager-service-type}]
15585 Tell the log-in manager (of type @var{login-manager-service-type}) to use
15586 @var{config}, an @code{<xorg-configuration>} record.
15588 Since the Xorg configuration is embedded in the log-in manager's
15589 configuration---e.g., @code{gdm-configuration}---this procedure provides a
15590 shorthand to set the Xorg configuration.
15593 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
15594 Return a @code{startx} script in which the modules, fonts, etc. specified
15595 in @var{config}, are available. The result should be used in place of
15598 Usually the X server is started by a login manager.
15602 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
15603 Add @var{package}, a package for a screen locker or screen saver whose
15604 command is @var{program}, to the set of setuid programs and add a PAM entry
15605 for it. For example:
15608 (screen-locker-service xlockmore "xlock")
15611 makes the good ol' XlockMore usable.
15615 @node Printing Services
15616 @subsection Printing Services
15618 @cindex printer support with CUPS
15619 The @code{(gnu services cups)} module provides a Guix service definition
15620 for the CUPS printing service. To add printer support to a Guix
15621 system, add a @code{cups-service} to the operating system definition:
15623 @deffn {Scheme Variable} cups-service-type
15624 The service type for the CUPS print server. Its value should be a valid
15625 CUPS configuration (see below). To use the default settings, simply
15628 (service cups-service-type)
15632 The CUPS configuration controls the basic things about your CUPS
15633 installation: what interfaces it listens on, what to do if a print job
15634 fails, how much logging to do, and so on. To actually add a printer,
15635 you have to visit the @url{http://localhost:631} URL, or use a tool such
15636 as GNOME's printer configuration services. By default, configuring a
15637 CUPS service will generate a self-signed certificate if needed, for
15638 secure connections to the print server.
15640 Suppose you want to enable the Web interface of CUPS and also add
15641 support for Epson printers @i{via} the @code{escpr} package and for HP
15642 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
15643 like this (you need to use the @code{(gnu packages cups)} module):
15646 (service cups-service-type
15647 (cups-configuration
15648 (web-interface? #t)
15650 (list cups-filters escpr hplip-minimal))))
15653 Note: If you wish to use the Qt5 based GUI which comes with the hplip
15654 package then it is suggested that you install the @code{hplip} package,
15655 either in your OS configuration file or as your user.
15657 The available configuration parameters follow. Each parameter
15658 definition is preceded by its type; for example, @samp{string-list foo}
15659 indicates that the @code{foo} parameter should be specified as a list of
15660 strings. There is also a way to specify the configuration as a string,
15661 if you have an old @code{cupsd.conf} file that you want to port over
15662 from some other system; see the end for more details.
15664 @c The following documentation was initially generated by
15665 @c (generate-documentation) in (gnu services cups). Manually maintained
15666 @c documentation is better, so we shouldn't hesitate to edit below as
15667 @c needed. However if the change you want to make to this documentation
15668 @c can be done in an automated way, it's probably easier to change
15669 @c (generate-documentation) than to make it below and have to deal with
15670 @c the churn as CUPS updates.
15673 Available @code{cups-configuration} fields are:
15675 @deftypevr {@code{cups-configuration} parameter} package cups
15679 @deftypevr {@code{cups-configuration} parameter} package-list extensions
15680 Drivers and other extensions to the CUPS package.
15683 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
15684 Configuration of where to write logs, what directories to use for print
15685 spools, and related privileged configuration parameters.
15687 Available @code{files-configuration} fields are:
15689 @deftypevr {@code{files-configuration} parameter} log-location access-log
15690 Defines the access log filename. Specifying a blank filename disables
15691 access log generation. The value @code{stderr} causes log entries to be
15692 sent to the standard error file when the scheduler is running in the
15693 foreground, or to the system log daemon when run in the background. The
15694 value @code{syslog} causes log entries to be sent to the system log
15695 daemon. The server name may be included in filenames using the string
15696 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
15698 Defaults to @samp{"/var/log/cups/access_log"}.
15701 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
15702 Where CUPS should cache data.
15704 Defaults to @samp{"/var/cache/cups"}.
15707 @deftypevr {@code{files-configuration} parameter} string config-file-perm
15708 Specifies the permissions for all configuration files that the scheduler
15711 Note that the permissions for the printers.conf file are currently
15712 masked to only allow access from the scheduler user (typically root).
15713 This is done because printer device URIs sometimes contain sensitive
15714 authentication information that should not be generally known on the
15715 system. There is no way to disable this security feature.
15717 Defaults to @samp{"0640"}.
15720 @deftypevr {@code{files-configuration} parameter} log-location error-log
15721 Defines the error log filename. Specifying a blank filename disables
15722 error log generation. The value @code{stderr} causes log entries to be
15723 sent to the standard error file when the scheduler is running in the
15724 foreground, or to the system log daemon when run in the background. The
15725 value @code{syslog} causes log entries to be sent to the system log
15726 daemon. The server name may be included in filenames using the string
15727 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
15729 Defaults to @samp{"/var/log/cups/error_log"}.
15732 @deftypevr {@code{files-configuration} parameter} string fatal-errors
15733 Specifies which errors are fatal, causing the scheduler to exit. The
15738 No errors are fatal.
15741 All of the errors below are fatal.
15744 Browsing initialization errors are fatal, for example failed connections
15745 to the DNS-SD daemon.
15748 Configuration file syntax errors are fatal.
15751 Listen or Port errors are fatal, except for IPv6 failures on the
15752 loopback or @code{any} addresses.
15755 Log file creation or write errors are fatal.
15758 Bad startup file permissions are fatal, for example shared TLS
15759 certificate and key files with world-read permissions.
15762 Defaults to @samp{"all -browse"}.
15765 @deftypevr {@code{files-configuration} parameter} boolean file-device?
15766 Specifies whether the file pseudo-device can be used for new printer
15767 queues. The URI @uref{file:///dev/null} is always allowed.
15769 Defaults to @samp{#f}.
15772 @deftypevr {@code{files-configuration} parameter} string group
15773 Specifies the group name or ID that will be used when executing external
15776 Defaults to @samp{"lp"}.
15779 @deftypevr {@code{files-configuration} parameter} string log-file-perm
15780 Specifies the permissions for all log files that the scheduler writes.
15782 Defaults to @samp{"0644"}.
15785 @deftypevr {@code{files-configuration} parameter} log-location page-log
15786 Defines the page log filename. Specifying a blank filename disables
15787 page log generation. The value @code{stderr} causes log entries to be
15788 sent to the standard error file when the scheduler is running in the
15789 foreground, or to the system log daemon when run in the background. The
15790 value @code{syslog} causes log entries to be sent to the system log
15791 daemon. The server name may be included in filenames using the string
15792 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
15794 Defaults to @samp{"/var/log/cups/page_log"}.
15797 @deftypevr {@code{files-configuration} parameter} string remote-root
15798 Specifies the username that is associated with unauthenticated accesses
15799 by clients claiming to be the root user. The default is @code{remroot}.
15801 Defaults to @samp{"remroot"}.
15804 @deftypevr {@code{files-configuration} parameter} file-name request-root
15805 Specifies the directory that contains print jobs and other HTTP request
15808 Defaults to @samp{"/var/spool/cups"}.
15811 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
15812 Specifies the level of security sandboxing that is applied to print
15813 filters, backends, and other child processes of the scheduler; either
15814 @code{relaxed} or @code{strict}. This directive is currently only
15815 used/supported on macOS.
15817 Defaults to @samp{strict}.
15820 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
15821 Specifies the location of TLS certificates and private keys. CUPS will
15822 look for public and private keys in this directory: @file{.crt} files
15823 for PEM-encoded certificates and corresponding @file{.key} files for
15824 PEM-encoded private keys.
15826 Defaults to @samp{"/etc/cups/ssl"}.
15829 @deftypevr {@code{files-configuration} parameter} file-name server-root
15830 Specifies the directory containing the server configuration files.
15832 Defaults to @samp{"/etc/cups"}.
15835 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
15836 Specifies whether the scheduler calls fsync(2) after writing
15837 configuration or state files.
15839 Defaults to @samp{#f}.
15842 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
15843 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
15846 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
15847 Specifies the directory where temporary files are stored.
15849 Defaults to @samp{"/var/spool/cups/tmp"}.
15852 @deftypevr {@code{files-configuration} parameter} string user
15853 Specifies the user name or ID that is used when running external
15856 Defaults to @samp{"lp"}.
15859 @deftypevr {@code{files-configuration} parameter} string set-env
15860 Set the specified environment variable to be passed to child processes.
15862 Defaults to @samp{"variable value"}.
15866 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
15867 Specifies the logging level for the AccessLog file. The @code{config}
15868 level logs when printers and classes are added, deleted, or modified and
15869 when configuration files are accessed or updated. The @code{actions}
15870 level logs when print jobs are submitted, held, released, modified, or
15871 canceled, and any of the conditions for @code{config}. The @code{all}
15872 level logs all requests.
15874 Defaults to @samp{actions}.
15877 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
15878 Specifies whether to purge job history data automatically when it is no
15879 longer required for quotas.
15881 Defaults to @samp{#f}.
15884 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
15885 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
15886 For example, @samp{"_cups" "_print"} will tell network clients that both
15887 CUPS sharing and IPP Everywhere are supported.
15889 Defaults to @samp{"_cups"}.
15892 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
15893 Specifies which protocols to use for local printer sharing.
15895 Defaults to @samp{dnssd}.
15898 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
15899 Specifies whether the CUPS web interface is advertised.
15901 Defaults to @samp{#f}.
15904 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
15905 Specifies whether shared printers are advertised.
15907 Defaults to @samp{#f}.
15910 @deftypevr {@code{cups-configuration} parameter} string classification
15911 Specifies the security classification of the server. Any valid banner
15912 name can be used, including @samp{"classified"}, @samp{"confidential"},
15913 @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
15914 banner can be omitted to disable secure printing functions.
15916 Defaults to @samp{""}.
15919 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
15920 Specifies whether users may override the classification (cover page) of
15921 individual print jobs using the @code{job-sheets} option.
15923 Defaults to @samp{#f}.
15926 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
15927 Specifies the default type of authentication to use.
15929 Defaults to @samp{Basic}.
15932 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
15933 Specifies whether encryption will be used for authenticated requests.
15935 Defaults to @samp{Required}.
15938 @deftypevr {@code{cups-configuration} parameter} string default-language
15939 Specifies the default language to use for text and web content.
15941 Defaults to @samp{"en"}.
15944 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
15945 Specifies the default paper size for new print queues. @samp{"Auto"}
15946 uses a locale-specific default, while @samp{"None"} specifies there is
15947 no default paper size. Specific size names are typically
15948 @samp{"Letter"} or @samp{"A4"}.
15950 Defaults to @samp{"Auto"}.
15953 @deftypevr {@code{cups-configuration} parameter} string default-policy
15954 Specifies the default access policy to use.
15956 Defaults to @samp{"default"}.
15959 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
15960 Specifies whether local printers are shared by default.
15962 Defaults to @samp{#t}.
15965 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
15966 Specifies the delay for updating of configuration and state files, in
15967 seconds. A value of 0 causes the update to happen as soon as possible,
15968 typically within a few milliseconds.
15970 Defaults to @samp{30}.
15973 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
15974 Specifies what to do when an error occurs. Possible values are
15975 @code{abort-job}, which will discard the failed print job;
15976 @code{retry-job}, which will retry the job at a later time;
15977 @code{retry-current-job}, which retries the failed job immediately; and
15978 @code{stop-printer}, which stops the printer.
15980 Defaults to @samp{stop-printer}.
15983 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
15984 Specifies the maximum cost of filters that are run concurrently, which
15985 can be used to minimize disk, memory, and CPU resource problems. A
15986 limit of 0 disables filter limiting. An average print to a
15987 non-PostScript printer needs a filter limit of about 200. A PostScript
15988 printer needs about half that (100). Setting the limit below these
15989 thresholds will effectively limit the scheduler to printing a single job
15992 Defaults to @samp{0}.
15995 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
15996 Specifies the scheduling priority of filters that are run to print a
15997 job. The nice value ranges from 0, the highest priority, to 19, the
16000 Defaults to @samp{0}.
16003 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
16004 Specifies whether to do reverse lookups on connecting clients. The
16005 @code{double} setting causes @code{cupsd} to verify that the hostname
16006 resolved from the address matches one of the addresses returned for that
16007 hostname. Double lookups also prevent clients with unregistered
16008 addresses from connecting to your server. Only set this option to
16009 @code{#t} or @code{double} if absolutely required.
16011 Defaults to @samp{#f}.
16014 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
16015 Specifies the number of seconds to wait before killing the filters and
16016 backend associated with a canceled or held job.
16018 Defaults to @samp{30}.
16021 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
16022 Specifies the interval between retries of jobs in seconds. This is
16023 typically used for fax queues but can also be used with normal print
16024 queues whose error policy is @code{retry-job} or
16025 @code{retry-current-job}.
16027 Defaults to @samp{30}.
16030 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
16031 Specifies the number of retries that are done for jobs. This is
16032 typically used for fax queues but can also be used with normal print
16033 queues whose error policy is @code{retry-job} or
16034 @code{retry-current-job}.
16036 Defaults to @samp{5}.
16039 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
16040 Specifies whether to support HTTP keep-alive connections.
16042 Defaults to @samp{#t}.
16045 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
16046 Specifies how long an idle client connection remains open, in seconds.
16048 Defaults to @samp{30}.
16051 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
16052 Specifies the maximum size of print files, IPP requests, and HTML form
16053 data. A limit of 0 disables the limit check.
16055 Defaults to @samp{0}.
16058 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
16059 Listens on the specified interfaces for connections. Valid values are
16060 of the form @var{address}:@var{port}, where @var{address} is either an
16061 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
16062 indicate all addresses. Values can also be file names of local UNIX
16063 domain sockets. The Listen directive is similar to the Port directive
16064 but allows you to restrict access to specific interfaces or networks.
16067 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
16068 Specifies the number of pending connections that will be allowed. This
16069 normally only affects very busy servers that have reached the MaxClients
16070 limit, but can also be triggered by large numbers of simultaneous
16071 connections. When the limit is reached, the operating system will
16072 refuse additional connections until the scheduler can accept the pending
16075 Defaults to @samp{128}.
16078 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
16079 Specifies a set of additional access controls.
16081 Available @code{location-access-controls} fields are:
16083 @deftypevr {@code{location-access-controls} parameter} file-name path
16084 Specifies the URI path to which the access control applies.
16087 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
16088 Access controls for all access to this path, in the same format as the
16089 @code{access-controls} of @code{operation-access-control}.
16091 Defaults to @samp{()}.
16094 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
16095 Access controls for method-specific access to this path.
16097 Defaults to @samp{()}.
16099 Available @code{method-access-controls} fields are:
16101 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
16102 If @code{#t}, apply access controls to all methods except the listed
16103 methods. Otherwise apply to only the listed methods.
16105 Defaults to @samp{#f}.
16108 @deftypevr {@code{method-access-controls} parameter} method-list methods
16109 Methods to which this access control applies.
16111 Defaults to @samp{()}.
16114 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
16115 Access control directives, as a list of strings. Each string should be
16116 one directive, such as @samp{"Order allow,deny"}.
16118 Defaults to @samp{()}.
16123 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
16124 Specifies the number of debugging messages that are retained for logging
16125 if an error occurs in a print job. Debug messages are logged regardless
16126 of the LogLevel setting.
16128 Defaults to @samp{100}.
16131 @deftypevr {@code{cups-configuration} parameter} log-level log-level
16132 Specifies the level of logging for the ErrorLog file. The value
16133 @code{none} stops all logging while @code{debug2} logs everything.
16135 Defaults to @samp{info}.
16138 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
16139 Specifies the format of the date and time in the log files. The value
16140 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
16142 Defaults to @samp{standard}.
16145 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
16146 Specifies the maximum number of simultaneous clients that are allowed by
16149 Defaults to @samp{100}.
16152 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
16153 Specifies the maximum number of simultaneous clients that are allowed
16154 from a single address.
16156 Defaults to @samp{100}.
16159 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
16160 Specifies the maximum number of copies that a user can print of each
16163 Defaults to @samp{9999}.
16166 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
16167 Specifies the maximum time a job may remain in the @code{indefinite}
16168 hold state before it is canceled. A value of 0 disables cancellation of
16171 Defaults to @samp{0}.
16174 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
16175 Specifies the maximum number of simultaneous jobs that are allowed. Set
16176 to 0 to allow an unlimited number of jobs.
16178 Defaults to @samp{500}.
16181 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
16182 Specifies the maximum number of simultaneous jobs that are allowed per
16183 printer. A value of 0 allows up to MaxJobs jobs per printer.
16185 Defaults to @samp{0}.
16188 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
16189 Specifies the maximum number of simultaneous jobs that are allowed per
16190 user. A value of 0 allows up to MaxJobs jobs per user.
16192 Defaults to @samp{0}.
16195 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
16196 Specifies the maximum time a job may take to print before it is
16197 canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
16199 Defaults to @samp{10800}.
16202 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
16203 Specifies the maximum size of the log files before they are rotated, in
16204 bytes. The value 0 disables log rotation.
16206 Defaults to @samp{1048576}.
16209 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
16210 Specifies the maximum amount of time to allow between files in a
16211 multiple file print job, in seconds.
16213 Defaults to @samp{300}.
16216 @deftypevr {@code{cups-configuration} parameter} string page-log-format
16217 Specifies the format of PageLog lines. Sequences beginning with percent
16218 (@samp{%}) characters are replaced with the corresponding information,
16219 while all other characters are copied literally. The following percent
16220 sequences are recognized:
16224 insert a single percent character
16227 insert the value of the specified IPP attribute
16230 insert the number of copies for the current page
16233 insert the current page number
16236 insert the current date and time in common log format
16242 insert the printer name
16245 insert the username
16248 A value of the empty string disables page logging. The string @code{%p
16249 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
16250 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
16253 Defaults to @samp{""}.
16256 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
16257 Passes the specified environment variable(s) to child processes; a list
16260 Defaults to @samp{()}.
16263 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
16264 Specifies named access control policies.
16266 Available @code{policy-configuration} fields are:
16268 @deftypevr {@code{policy-configuration} parameter} string name
16269 Name of the policy.
16272 @deftypevr {@code{policy-configuration} parameter} string job-private-access
16273 Specifies an access list for a job's private values. @code{@@ACL} maps
16274 to the printer's requesting-user-name-allowed or
16275 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
16276 owner. @code{@@SYSTEM} maps to the groups listed for the
16277 @code{system-group} field of the @code{files-config} configuration,
16278 which is reified into the @code{cups-files.conf(5)} file. Other
16279 possible elements of the access list include specific user names, and
16280 @code{@@@var{group}} to indicate members of a specific group. The
16281 access list may also be simply @code{all} or @code{default}.
16283 Defaults to @samp{"@@OWNER @@SYSTEM"}.
16286 @deftypevr {@code{policy-configuration} parameter} string job-private-values
16287 Specifies the list of job values to make private, or @code{all},
16288 @code{default}, or @code{none}.
16290 Defaults to @samp{"job-name job-originating-host-name
16291 job-originating-user-name phone"}.
16294 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
16295 Specifies an access list for a subscription's private values.
16296 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
16297 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
16298 owner. @code{@@SYSTEM} maps to the groups listed for the
16299 @code{system-group} field of the @code{files-config} configuration,
16300 which is reified into the @code{cups-files.conf(5)} file. Other
16301 possible elements of the access list include specific user names, and
16302 @code{@@@var{group}} to indicate members of a specific group. The
16303 access list may also be simply @code{all} or @code{default}.
16305 Defaults to @samp{"@@OWNER @@SYSTEM"}.
16308 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
16309 Specifies the list of job values to make private, or @code{all},
16310 @code{default}, or @code{none}.
16312 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
16313 notify-subscriber-user-name notify-user-data"}.
16316 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
16317 Access control by IPP operation.
16319 Defaults to @samp{()}.
16323 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
16324 Specifies whether job files (documents) are preserved after a job is
16325 printed. If a numeric value is specified, job files are preserved for
16326 the indicated number of seconds after printing. Otherwise a boolean
16327 value applies indefinitely.
16329 Defaults to @samp{86400}.
16332 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
16333 Specifies whether the job history is preserved after a job is printed.
16334 If a numeric value is specified, the job history is preserved for the
16335 indicated number of seconds after printing. If @code{#t}, the job
16336 history is preserved until the MaxJobs limit is reached.
16338 Defaults to @samp{#t}.
16341 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
16342 Specifies the amount of time to wait for job completion before
16343 restarting the scheduler.
16345 Defaults to @samp{30}.
16348 @deftypevr {@code{cups-configuration} parameter} string rip-cache
16349 Specifies the maximum amount of memory to use when converting documents
16350 into bitmaps for a printer.
16352 Defaults to @samp{"128m"}.
16355 @deftypevr {@code{cups-configuration} parameter} string server-admin
16356 Specifies the email address of the server administrator.
16358 Defaults to @samp{"root@@localhost.localdomain"}.
16361 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
16362 The ServerAlias directive is used for HTTP Host header validation when
16363 clients connect to the scheduler from external interfaces. Using the
16364 special name @code{*} can expose your system to known browser-based DNS
16365 rebinding attacks, even when accessing sites through a firewall. If the
16366 auto-discovery of alternate names does not work, we recommend listing
16367 each alternate name with a ServerAlias directive instead of using
16370 Defaults to @samp{*}.
16373 @deftypevr {@code{cups-configuration} parameter} string server-name
16374 Specifies the fully-qualified host name of the server.
16376 Defaults to @samp{"localhost"}.
16379 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
16380 Specifies what information is included in the Server header of HTTP
16381 responses. @code{None} disables the Server header. @code{ProductOnly}
16382 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
16383 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
16384 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
16385 the output of the @code{uname} command. @code{Full} reports @code{CUPS
16386 2.0.0 (@var{uname}) IPP/2.0}.
16388 Defaults to @samp{Minimal}.
16391 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
16392 Listens on the specified interfaces for encrypted connections. Valid
16393 values are of the form @var{address}:@var{port}, where @var{address} is
16394 either an IPv6 address enclosed in brackets, an IPv4 address, or
16395 @code{*} to indicate all addresses.
16397 Defaults to @samp{()}.
16400 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
16401 Sets encryption options. By default, CUPS only supports encryption
16402 using TLS v1.0 or higher using known secure cipher suites. Security is
16403 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
16404 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
16405 suites, which are required for some older clients. The @code{AllowSSL3} option
16406 enables SSL v3.0, which is required for some older clients that do not support
16407 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
16408 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
16409 protocol version to TLS v1.1.
16411 Defaults to @samp{()}.
16414 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
16415 Specifies whether the scheduler requires clients to strictly adhere to
16416 the IPP specifications.
16418 Defaults to @samp{#f}.
16421 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
16422 Specifies the HTTP request timeout, in seconds.
16424 Defaults to @samp{300}.
16428 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
16429 Specifies whether the web interface is enabled.
16431 Defaults to @samp{#f}.
16434 At this point you're probably thinking ``oh dear, Guix manual, I like
16435 you but you can stop already with the configuration options''. Indeed.
16436 However, one more point: it could be that you have an existing
16437 @code{cupsd.conf} that you want to use. In that case, you can pass an
16438 @code{opaque-cups-configuration} as the configuration of a
16439 @code{cups-service-type}.
16441 Available @code{opaque-cups-configuration} fields are:
16443 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
16447 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
16448 The contents of the @code{cupsd.conf}, as a string.
16451 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
16452 The contents of the @code{cups-files.conf} file, as a string.
16455 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
16456 strings of the same name, you could instantiate a CUPS service like
16460 (service cups-service-type
16461 (opaque-cups-configuration
16462 (cupsd.conf cupsd.conf)
16463 (cups-files.conf cups-files.conf)))
16467 @node Desktop Services
16468 @subsection Desktop Services
16470 The @code{(gnu services desktop)} module provides services that are
16471 usually useful in the context of a ``desktop'' setup---that is, on a
16472 machine running a graphical display server, possibly with graphical user
16473 interfaces, etc. It also defines services that provide specific desktop
16474 environments like GNOME, Xfce or MATE.
16476 To simplify things, the module defines a variable containing the set of
16477 services that users typically expect on a machine with a graphical
16478 environment and networking:
16480 @defvr {Scheme Variable} %desktop-services
16481 This is a list of services that builds upon @code{%base-services} and
16482 adds or adjusts services for a typical ``desktop'' setup.
16484 In particular, it adds a graphical login manager (@pxref{X Window,
16485 @code{gdm-service-type}}), screen lockers, a network management tool
16486 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
16487 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
16488 energy and color management services, the @code{elogind} login and seat
16489 manager, the Polkit privilege service, the GeoClue location service, the
16490 AccountsService daemon that allows authorized users change system passwords,
16491 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
16492 name service switch service configured to be able to use @code{nss-mdns}
16493 (@pxref{Name Service Switch, mDNS}).
16496 The @code{%desktop-services} variable can be used as the @code{services}
16497 field of an @code{operating-system} declaration (@pxref{operating-system
16498 Reference, @code{services}}).
16500 Additionally, the @code{gnome-desktop-service-type},
16501 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
16502 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
16503 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
16504 services like the backlight adjustment helpers and the power management
16505 utilities are added to the system, extending @code{polkit} and @code{dbus}
16506 appropriately, allowing GNOME to operate with elevated privileges on a
16507 limited number of special-purpose system interfaces. Additionally,
16508 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
16509 metapackage to the system profile. Likewise, adding the Xfce service
16510 not only adds the @code{xfce} metapackage to the system profile, but it
16511 also gives the Thunar file manager the ability to open a ``root-mode''
16512 file management window, if the user authenticates using the
16513 administrator's password via the standard polkit graphical interface.
16514 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
16515 appropriately, allowing MATE to operate with elevated privileges on a
16516 limited number of special-purpose system interfaces. Additionally,
16517 adding a service of type @code{mate-desktop-service-type} adds the MATE
16518 metapackage to the system profile. ``Adding Enlightenment'' means that
16519 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
16520 are set as setuid, allowing Enlightenment's screen locker and other
16521 functionality to work as expected.
16523 The desktop environments in Guix use the Xorg display server by
16524 default. If you'd like to use the newer display server protocol
16525 called Wayland, you need to use the @code{sddm-service} instead of
16526 GDM as the graphical login manager. You should then
16527 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
16528 also try starting GNOME on Wayland manually from a TTY with the
16529 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
16530 gnome-session``. Currently only GNOME has support for Wayland.
16532 @defvr {Scheme Variable} gnome-desktop-service-type
16533 This is the type of the service that adds the @uref{https://www.gnome.org,
16534 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
16535 object (see below).
16537 This service adds the @code{gnome} package to the system profile, and extends
16538 polkit with the actions from @code{gnome-settings-daemon}.
16541 @deftp {Data Type} gnome-desktop-configuration
16542 Configuration record for the GNOME desktop environment.
16545 @item @code{gnome} (default: @code{gnome})
16546 The GNOME package to use.
16550 @defvr {Scheme Variable} xfce-desktop-service-type
16551 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
16552 desktop environment. Its value is an @code{xfce-desktop-configuration} object
16555 This service adds the @code{xfce} package to the system profile, and
16556 extends polkit with the ability for @code{thunar} to manipulate the file
16557 system as root from within a user session, after the user has authenticated
16558 with the administrator's password.
16561 @deftp {Data Type} xfce-desktop-configuration
16562 Configuration record for the Xfce desktop environment.
16565 @item @code{xfce} (default: @code{xfce})
16566 The Xfce package to use.
16570 @deffn {Scheme Variable} mate-desktop-service-type
16571 This is the type of the service that runs the @uref{https://mate-desktop.org/,
16572 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
16573 object (see below).
16575 This service adds the @code{mate} package to the system
16576 profile, and extends polkit with the actions from
16577 @code{mate-settings-daemon}.
16580 @deftp {Data Type} mate-desktop-configuration
16581 Configuration record for the MATE desktop environment.
16584 @item @code{mate} (default: @code{mate})
16585 The MATE package to use.
16589 @deffn {Scheme Variable} enlightenment-desktop-service-type
16590 Return a service that adds the @code{enlightenment} package to the system
16591 profile, and extends dbus with actions from @code{efl}.
16594 @deftp {Data Type} enlightenment-desktop-service-configuration
16596 @item @code{enlightenment} (default: @code{enlightenment})
16597 The enlightenment package to use.
16601 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
16602 the default @code{%desktop-services} variable doesn't include any of
16603 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
16604 @code{%desktop-services} in the @code{services} field of your
16605 @code{operating-system}:
16608 (use-modules (gnu))
16609 (use-service-modules desktop)
16612 ;; cons* adds items to the list given as its last argument.
16613 (services (cons* (service gnome-desktop-service-type)
16614 (service xfce-desktop-service)
16615 %desktop-services))
16619 These desktop environments will then be available as options in the
16620 graphical login window.
16622 The actual service definitions included in @code{%desktop-services} and
16623 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
16624 are described below.
16626 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
16627 Return a service that runs the ``system bus'', using @var{dbus}, with
16628 support for @var{services}.
16630 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
16631 facility. Its system bus is used to allow system services to communicate
16632 and to be notified of system-wide events.
16634 @var{services} must be a list of packages that provide an
16635 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
16636 and policy files. For example, to allow avahi-daemon to use the system bus,
16637 @var{services} must be equal to @code{(list avahi)}.
16640 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
16641 Return a service that runs the @code{elogind} login and
16642 seat management daemon. @uref{https://github.com/elogind/elogind,
16643 Elogind} exposes a D-Bus interface that can be used to know which users
16644 are logged in, know what kind of sessions they have open, suspend the
16645 system, inhibit system suspend, reboot the system, and other tasks.
16647 Elogind handles most system-level power events for a computer, for
16648 example suspending the system when a lid is closed, or shutting it down
16649 when the power button is pressed.
16651 The @var{config} keyword argument specifies the configuration for
16652 elogind, and should be the result of an @code{(elogind-configuration
16653 (@var{parameter} @var{value})...)} invocation. Available parameters and
16654 their default values are:
16657 @item kill-user-processes?
16659 @item kill-only-users
16661 @item kill-exclude-users
16663 @item inhibit-delay-max-seconds
16665 @item handle-power-key
16667 @item handle-suspend-key
16669 @item handle-hibernate-key
16671 @item handle-lid-switch
16673 @item handle-lid-switch-docked
16675 @item power-key-ignore-inhibited?
16677 @item suspend-key-ignore-inhibited?
16679 @item hibernate-key-ignore-inhibited?
16681 @item lid-switch-ignore-inhibited?
16683 @item holdoff-timeout-seconds
16687 @item idle-action-seconds
16689 @item runtime-directory-size-percent
16691 @item runtime-directory-size
16695 @item suspend-state
16696 @code{("mem" "standby" "freeze")}
16699 @item hibernate-state
16701 @item hibernate-mode
16702 @code{("platform" "shutdown")}
16703 @item hybrid-sleep-state
16705 @item hybrid-sleep-mode
16706 @code{("suspend" "platform" "shutdown")}
16710 @deffn {Scheme Procedure} accountsservice-service @
16711 [#:accountsservice @var{accountsservice}]
16712 Return a service that runs AccountsService, a system service that can
16713 list available accounts, change their passwords, and so on.
16714 AccountsService integrates with PolicyKit to enable unprivileged users
16715 to acquire the capability to modify their system configuration.
16716 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
16717 accountsservice web site} for more information.
16719 The @var{accountsservice} keyword argument is the @code{accountsservice}
16720 package to expose as a service.
16723 @deffn {Scheme Procedure} polkit-service @
16724 [#:polkit @var{polkit}]
16725 Return a service that runs the
16726 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
16727 management service}, which allows system administrators to grant access to
16728 privileged operations in a structured way. By querying the Polkit service, a
16729 privileged system component can know when it should grant additional
16730 capabilities to ordinary users. For example, an ordinary user can be granted
16731 the capability to suspend the system if the user is logged in locally.
16734 @defvr {Scheme Variable} polkit-wheel-service
16735 Service that adds the @code{wheel} group as admins to the Polkit
16736 service. This makes it so that users in the @code{wheel} group are queried
16737 for their own passwords when performing administrative actions instead of
16738 @code{root}'s, similar to the behaviour used by @code{sudo}.
16741 @defvr {Scheme Variable} upower-service-type
16742 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
16743 system-wide monitor for power consumption and battery levels, with the given
16744 configuration settings.
16746 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
16747 notably used by GNOME.
16750 @deftp {Data Type} upower-configuration
16751 Data type representation the configuration for UPower.
16755 @item @code{upower} (default: @var{upower})
16756 Package to use for @code{upower}.
16758 @item @code{watts-up-pro?} (default: @code{#f})
16759 Enable the Watts Up Pro device.
16761 @item @code{poll-batteries?} (default: @code{#t})
16762 Enable polling the kernel for battery level changes.
16764 @item @code{ignore-lid?} (default: @code{#f})
16765 Ignore the lid state, this can be useful if it's incorrect on a device.
16767 @item @code{use-percentage-for-policy?} (default: @code{#f})
16768 Whether battery percentage based policy should be used. The default is to use
16769 the time left, change to @code{#t} to use the percentage.
16771 @item @code{percentage-low} (default: @code{10})
16772 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
16773 at which the battery is considered low.
16775 @item @code{percentage-critical} (default: @code{3})
16776 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
16777 at which the battery is considered critical.
16779 @item @code{percentage-action} (default: @code{2})
16780 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
16781 at which action will be taken.
16783 @item @code{time-low} (default: @code{1200})
16784 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
16785 seconds at which the battery is considered low.
16787 @item @code{time-critical} (default: @code{300})
16788 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
16789 seconds at which the battery is considered critical.
16791 @item @code{time-action} (default: @code{120})
16792 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
16793 seconds at which action will be taken.
16795 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
16796 The action taken when @code{percentage-action} or @code{time-action} is
16797 reached (depending on the configuration of @code{use-percentage-for-policy?}).
16799 Possible values are:
16809 @code{'hybrid-sleep}.
16815 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
16816 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
16817 UDisks}, a @dfn{disk management} daemon that provides user interfaces
16818 with notifications and ways to mount/unmount disks. Programs that talk
16819 to UDisks include the @command{udisksctl} command, part of UDisks, and
16820 GNOME Disks. Note that Udisks relies on the @command{mount} command, so
16821 it will only be able to use the file-system utilities installed in the
16822 system profile. For example if you want to be able to mount NTFS
16823 file-systems in read and write fashion, you'll need to have
16824 @code{ntfs-3g} installed system-wide.
16827 @deffn {Scheme Variable} colord-service-type
16828 This is the type of the service that runs @command{colord}, a system
16829 service with a D-Bus
16830 interface to manage the color profiles of input and output devices such as
16831 screens and scanners. It is notably used by the GNOME Color Manager graphical
16832 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
16833 site} for more information.
16836 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
16837 Return a configuration allowing an application to access GeoClue
16838 location data. @var{name} is the Desktop ID of the application, without
16839 the @code{.desktop} part. If @var{allowed?} is true, the application
16840 will have access to location information by default. The boolean
16841 @var{system?} value indicates whether an application is a system component
16842 or not. Finally @var{users} is a list of UIDs of all users for which
16843 this application is allowed location info access. An empty users list
16844 means that all users are allowed.
16847 @cindex scanner access
16848 @deffn {Scheme Procedure} sane-service-type
16849 This service provides access to scanners @i{via}
16850 @uref{http://www.sane-project.org, SANE} by installing the necessary udev
16854 @defvr {Scheme Variable} %standard-geoclue-applications
16855 The standard list of well-known GeoClue application configurations,
16856 granting authority to the GNOME date-and-time utility to ask for the
16857 current location in order to set the time zone, and allowing the
16858 IceCat and Epiphany web browsers to request location information.
16859 IceCat and Epiphany both query the user before allowing a web page to
16860 know the user's location.
16863 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
16864 [#:whitelist '()] @
16865 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
16866 [#:submit-data? #f]
16867 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
16868 [#:submission-nick "geoclue"] @
16869 [#:applications %standard-geoclue-applications]
16870 Return a service that runs the GeoClue location service. This service
16871 provides a D-Bus interface to allow applications to request access to a
16872 user's physical location, and optionally to add information to online
16873 location databases. See
16874 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
16875 web site} for more information.
16878 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
16879 [@w{#:auto-enable? #f}]
16880 Return a service that runs the @command{bluetoothd} daemon, which
16881 manages all the Bluetooth devices and provides a number of D-Bus
16882 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
16883 powered automatically at boot, which can be useful when using a
16884 bluetooth keyboard or mouse.
16886 Users need to be in the @code{lp} group to access the D-Bus service.
16889 @defvr {Scheme Variable} gnome-keyring-service-type
16890 This is the type of the service that adds the
16891 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
16892 value is a @code{gnome-keyring-configuration} object (see below).
16894 This service adds the @code{gnome-keyring} package to the system profile
16895 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
16896 a user's login keyring when they log in or setting its password with passwd.
16899 @deftp {Data Type} gnome-keyring-configuration
16900 Configuration record for the GNOME Keyring service.
16903 @item @code{keyring} (default: @code{gnome-keyring})
16904 The GNOME keyring package to use.
16906 @item @code{pam-services}
16907 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
16908 services to extend, where @var{service} is the name of an existing
16909 service to extend and @var{kind} is one of @code{login} or
16912 If @code{login} is given, it adds an optional
16913 @code{pam_gnome_keyring.so} to the auth block without arguments and to
16914 the session block with @code{auto_start}. If @code{passwd} is given, it
16915 adds an optional @code{pam_gnome_keyring.so} to the password block
16918 By default, this field contains ``gdm-password'' with the value @code{login}
16919 and ``passwd'' is with the value @code{passwd}.
16924 @node Sound Services
16925 @subsection Sound Services
16927 @cindex sound support
16929 @cindex PulseAudio, sound support
16931 The @code{(gnu services sound)} module provides a service to configure the
16932 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
16933 preferred ALSA output driver.
16935 @deffn {Scheme Variable} alsa-service-type
16936 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
16937 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
16938 configuration file. The value for this type is a @command{alsa-configuration}
16939 record as in this example:
16942 (service alsa-service-type)
16945 See below for details about @code{alsa-configuration}.
16948 @deftp {Data Type} alsa-configuration
16949 Data type representing the configuration for @code{alsa-service}.
16952 @item @code{alsa-plugins} (default: @var{alsa-plugins})
16953 @code{alsa-plugins} package to use.
16955 @item @code{pulseaudio?} (default: @var{#t})
16956 Whether ALSA applications should transparently be made to use the
16957 @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
16959 Using PulseAudio allows you to run several sound-producing applications
16960 at the same time and to individual control them @i{via}
16961 @command{pavucontrol}, among other things.
16963 @item @code{extra-options} (default: @var{""})
16964 String to append to the @file{/etc/asound.conf} file.
16969 Individual users who want to override the system configuration of ALSA can do
16970 it with the @file{~/.asoundrc} file:
16973 # In guix, we have to specify the absolute path for plugins.
16975 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
16978 # Routing ALSA to jack:
16979 # <http://jackaudio.org/faq/routing_alsa.html>.
16983 0 system:playback_1
16984 1 system:playback_2
17001 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
17004 @deffn {Scheme Variable} pulseaudio-service-type
17005 This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
17006 sound server. It exists to allow system overrides of the default settings
17007 via @code{pulseaudio-configuration}, see below.
17010 This service overrides per-user configuration files. If you want
17011 PulseAudio to honor configuraton files in @file{~/.config/pulse} you
17012 have to unset the environment variables @env{PULSE_CONFIG} and
17013 @env{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
17017 This service on its own does not ensure, that the @code{pulseaudio} package
17018 exists on your machine. It merely adds configuration files for it, as
17019 detailed below. In the (admittedly unlikely) case, that you find yourself
17020 without a @code{pulseaudio} package, consider enabling it through the
17021 @code{alsa-service-type} above.
17025 @deftp {Data Type} pulseaudio-configuration
17026 Data type representing the configuration for @code{pulseaudio-service}.
17029 @item @var{client-conf} (default: @code{'()})
17030 List of settings to set in @file{client.conf}.
17031 Accepts a list of strings or a symbol-value pairs. A string will be
17032 inserted as-is with a newline added. A pair will be formatted as
17033 ``key = value'', again with a newline added.
17035 @item @var{daemon-conf} (default: @code{'((flat-volumes . no))})
17036 List of settings to set in @file{daemon.conf}, formatted just like
17039 @item @var{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
17040 Script file to use as as @file{default.pa}.
17042 @item @var{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
17043 Script file to use as as @file{system.pa}.
17047 @deffn {Scheme Variable} ladspa-service-type
17048 This service sets the @var{LADSPA_PATH} variable, so that programs, which
17049 respect it, e.g. PulseAudio, can load LADSPA plugins.
17051 The following example will setup the service to enable modules from the
17052 @code{swh-plugins} package:
17055 (service ladspa-service-type
17056 (ladspa-configuration (plugins (list swh-plugins))))
17059 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
17064 @node Database Services
17065 @subsection Database Services
17069 The @code{(gnu services databases)} module provides the following services.
17071 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
17072 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
17073 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
17074 Return a service that runs @var{postgresql}, the PostgreSQL database
17077 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
17078 creates a database cluster with @var{locale} as the default
17079 locale, stored in @var{data-directory}. It then listens on @var{port}.
17081 @cindex postgresql extension-packages
17082 Additional extensions are loaded from packages listed in
17083 @var{extension-packages}. Extensions are available at runtime. For instance,
17084 to create a geographic database using the @code{postgis} extension, a user can
17085 configure the postgresql-service as in this example:
17089 (use-package-modules databases geo)
17093 ;; postgresql is required to run `psql' but postgis is not required for
17094 ;; proper operation.
17095 (packages (cons* postgresql %base-packages))
17098 (postgresql-service #:extension-packages (list postgis))
17102 Then the extension becomes visible and you can initialise an empty geographic
17103 database in this way:
17107 > create database postgistest;
17108 > \connect postgistest;
17109 > create extension postgis;
17110 > create extension postgis_topology;
17113 There is no need to add this field for contrib extensions such as hstore or
17114 dblink as they are already loadable by postgresql. This field is only
17115 required to add extensions provided by other packages.
17118 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
17119 Return a service that runs @command{mysqld}, the MySQL or MariaDB
17122 The optional @var{config} argument specifies the configuration for
17123 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
17126 @deftp {Data Type} mysql-configuration
17127 Data type representing the configuration of @var{mysql-service}.
17130 @item @code{mysql} (default: @var{mariadb})
17131 Package object of the MySQL database server, can be either @var{mariadb}
17134 For MySQL, a temporary root password will be displayed at activation time.
17135 For MariaDB, the root password is empty.
17137 @item @code{port} (default: @code{3306})
17138 TCP port on which the database server listens for incoming connections.
17142 @defvr {Scheme Variable} memcached-service-type
17143 This is the service type for the @uref{https://memcached.org/,
17144 Memcached} service, which provides a distributed in memory cache. The
17145 value for the service type is a @code{memcached-configuration} object.
17149 (service memcached-service-type)
17152 @deftp {Data Type} memcached-configuration
17153 Data type representing the configuration of memcached.
17156 @item @code{memcached} (default: @code{memcached})
17157 The Memcached package to use.
17159 @item @code{interfaces} (default: @code{'("0.0.0.0")})
17160 Network interfaces on which to listen.
17162 @item @code{tcp-port} (default: @code{11211})
17163 Port on which to accept connections on,
17165 @item @code{udp-port} (default: @code{11211})
17166 Port on which to accept UDP connections on, a value of 0 will disable
17167 listening on a UDP socket.
17169 @item @code{additional-options} (default: @code{'()})
17170 Additional command line options to pass to @code{memcached}.
17174 @defvr {Scheme Variable} mongodb-service-type
17175 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
17176 The value for the service type is a @code{mongodb-configuration} object.
17180 (service mongodb-service-type)
17183 @deftp {Data Type} mongodb-configuration
17184 Data type representing the configuration of mongodb.
17187 @item @code{mongodb} (default: @code{mongodb})
17188 The MongoDB package to use.
17190 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
17191 The configuration file for MongoDB.
17193 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
17194 This value is used to create the directory, so that it exists and is
17195 owned by the mongodb user. It should match the data-directory which
17196 MongoDB is configured to use through the configuration file.
17200 @defvr {Scheme Variable} redis-service-type
17201 This is the service type for the @uref{https://redis.io/, Redis}
17202 key/value store, whose value is a @code{redis-configuration} object.
17205 @deftp {Data Type} redis-configuration
17206 Data type representing the configuration of redis.
17209 @item @code{redis} (default: @code{redis})
17210 The Redis package to use.
17212 @item @code{bind} (default: @code{"127.0.0.1"})
17213 Network interface on which to listen.
17215 @item @code{port} (default: @code{6379})
17216 Port on which to accept connections on, a value of 0 will disable
17217 listening on a TCP socket.
17219 @item @code{working-directory} (default: @code{"/var/lib/redis"})
17220 Directory in which to store the database and related files.
17224 @node Mail Services
17225 @subsection Mail Services
17229 The @code{(gnu services mail)} module provides Guix service definitions
17230 for email services: IMAP, POP3, and LMTP servers, as well as mail
17231 transport agents (MTAs). Lots of acronyms! These services are detailed
17232 in the subsections below.
17234 @subsubheading Dovecot Service
17236 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
17237 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
17240 By default, Dovecot does not need much configuration; the default
17241 configuration object created by @code{(dovecot-configuration)} will
17242 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
17243 certificate will be generated for TLS-protected connections, though
17244 Dovecot will also listen on cleartext ports by default. There are a
17245 number of options, though, which mail administrators might need to change,
17246 and as is the case with other services, Guix allows the system
17247 administrator to specify these parameters via a uniform Scheme interface.
17249 For example, to specify that mail is located at @code{maildir~/.mail},
17250 one would instantiate the Dovecot service like this:
17253 (dovecot-service #:config
17254 (dovecot-configuration
17255 (mail-location "maildir:~/.mail")))
17258 The available configuration parameters follow. Each parameter
17259 definition is preceded by its type; for example, @samp{string-list foo}
17260 indicates that the @code{foo} parameter should be specified as a list of
17261 strings. There is also a way to specify the configuration as a string,
17262 if you have an old @code{dovecot.conf} file that you want to port over
17263 from some other system; see the end for more details.
17265 @c The following documentation was initially generated by
17266 @c (generate-documentation) in (gnu services mail). Manually maintained
17267 @c documentation is better, so we shouldn't hesitate to edit below as
17268 @c needed. However if the change you want to make to this documentation
17269 @c can be done in an automated way, it's probably easier to change
17270 @c (generate-documentation) than to make it below and have to deal with
17271 @c the churn as dovecot updates.
17273 Available @code{dovecot-configuration} fields are:
17275 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
17276 The dovecot package.
17279 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
17280 A list of IPs or hosts where to listen for connections. @samp{*}
17281 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
17282 interfaces. If you want to specify non-default ports or anything more
17283 complex, customize the address and port fields of the
17284 @samp{inet-listener} of the specific services you are interested in.
17287 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
17288 List of protocols we want to serve. Available protocols include
17289 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
17291 Available @code{protocol-configuration} fields are:
17293 @deftypevr {@code{protocol-configuration} parameter} string name
17294 The name of the protocol.
17297 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
17298 UNIX socket path to the master authentication server to find users.
17299 This is used by imap (for shared users) and lda.
17300 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
17303 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
17304 Space separated list of plugins to load.
17307 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
17308 Maximum number of IMAP connections allowed for a user from each IP
17309 address. NOTE: The username is compared case-sensitively.
17310 Defaults to @samp{10}.
17315 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
17316 List of services to enable. Available services include @samp{imap},
17317 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
17320 Available @code{service-configuration} fields are:
17322 @deftypevr {@code{service-configuration} parameter} string kind
17323 The service kind. Valid values include @code{director},
17324 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
17325 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
17326 @code{tcpwrap}, @code{quota-warning}, or anything else.
17329 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
17330 Listeners for the service. A listener is either a
17331 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
17332 an @code{inet-listener-configuration}.
17333 Defaults to @samp{()}.
17335 Available @code{unix-listener-configuration} fields are:
17337 @deftypevr {@code{unix-listener-configuration} parameter} string path
17338 Path to the file, relative to @code{base-dir} field. This is also used as
17342 @deftypevr {@code{unix-listener-configuration} parameter} string mode
17343 The access mode for the socket.
17344 Defaults to @samp{"0600"}.
17347 @deftypevr {@code{unix-listener-configuration} parameter} string user
17348 The user to own the socket.
17349 Defaults to @samp{""}.
17352 @deftypevr {@code{unix-listener-configuration} parameter} string group
17353 The group to own the socket.
17354 Defaults to @samp{""}.
17358 Available @code{fifo-listener-configuration} fields are:
17360 @deftypevr {@code{fifo-listener-configuration} parameter} string path
17361 Path to the file, relative to @code{base-dir} field. This is also used as
17365 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
17366 The access mode for the socket.
17367 Defaults to @samp{"0600"}.
17370 @deftypevr {@code{fifo-listener-configuration} parameter} string user
17371 The user to own the socket.
17372 Defaults to @samp{""}.
17375 @deftypevr {@code{fifo-listener-configuration} parameter} string group
17376 The group to own the socket.
17377 Defaults to @samp{""}.
17381 Available @code{inet-listener-configuration} fields are:
17383 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
17384 The protocol to listen for.
17387 @deftypevr {@code{inet-listener-configuration} parameter} string address
17388 The address on which to listen, or empty for all addresses.
17389 Defaults to @samp{""}.
17392 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
17393 The port on which to listen.
17396 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
17397 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
17399 Defaults to @samp{#t}.
17404 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
17405 Maximum number of simultaneous client connections per process. Once
17406 this number of connections is received, the next incoming connection
17407 will prompt Dovecot to spawn another process. If set to 0,
17408 @code{default-client-limit} is used instead.
17410 Defaults to @samp{0}.
17414 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
17415 Number of connections to handle before starting a new process.
17416 Typically the only useful values are 0 (unlimited) or 1. 1 is more
17417 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
17418 Defaults to @samp{1}.
17422 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
17423 Maximum number of processes that can exist for this service. If set to
17424 0, @code{default-process-limit} is used instead.
17426 Defaults to @samp{0}.
17430 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
17431 Number of processes to always keep waiting for more connections.
17432 Defaults to @samp{0}.
17435 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
17436 If you set @samp{service-count 0}, you probably need to grow
17438 Defaults to @samp{256000000}.
17443 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
17444 Dict configuration, as created by the @code{dict-configuration}
17447 Available @code{dict-configuration} fields are:
17449 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
17450 A list of key-value pairs that this dict should hold.
17451 Defaults to @samp{()}.
17456 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
17457 A list of passdb configurations, each one created by the
17458 @code{passdb-configuration} constructor.
17460 Available @code{passdb-configuration} fields are:
17462 @deftypevr {@code{passdb-configuration} parameter} string driver
17463 The driver that the passdb should use. Valid values include
17464 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
17466 Defaults to @samp{"pam"}.
17469 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
17470 Space separated list of arguments to the passdb driver.
17471 Defaults to @samp{""}.
17476 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
17477 List of userdb configurations, each one created by the
17478 @code{userdb-configuration} constructor.
17480 Available @code{userdb-configuration} fields are:
17482 @deftypevr {@code{userdb-configuration} parameter} string driver
17483 The driver that the userdb should use. Valid values include
17484 @samp{passwd} and @samp{static}.
17485 Defaults to @samp{"passwd"}.
17488 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
17489 Space separated list of arguments to the userdb driver.
17490 Defaults to @samp{""}.
17493 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
17494 Override fields from passwd.
17495 Defaults to @samp{()}.
17500 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
17501 Plug-in configuration, created by the @code{plugin-configuration}
17505 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
17506 List of namespaces. Each item in the list is created by the
17507 @code{namespace-configuration} constructor.
17509 Available @code{namespace-configuration} fields are:
17511 @deftypevr {@code{namespace-configuration} parameter} string name
17512 Name for this namespace.
17515 @deftypevr {@code{namespace-configuration} parameter} string type
17516 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
17517 Defaults to @samp{"private"}.
17520 @deftypevr {@code{namespace-configuration} parameter} string separator
17521 Hierarchy separator to use. You should use the same separator for
17522 all namespaces or some clients get confused. @samp{/} is usually a good
17523 one. The default however depends on the underlying mail storage
17525 Defaults to @samp{""}.
17528 @deftypevr {@code{namespace-configuration} parameter} string prefix
17529 Prefix required to access this namespace. This needs to be
17530 different for all namespaces. For example @samp{Public/}.
17531 Defaults to @samp{""}.
17534 @deftypevr {@code{namespace-configuration} parameter} string location
17535 Physical location of the mailbox. This is in the same format as
17536 mail_location, which is also the default for it.
17537 Defaults to @samp{""}.
17540 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
17541 There can be only one INBOX, and this setting defines which
17543 Defaults to @samp{#f}.
17546 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
17547 If namespace is hidden, it's not advertised to clients via NAMESPACE
17548 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
17549 useful when converting from another server with different namespaces
17550 which you want to deprecate but still keep working. For example you can
17551 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
17553 Defaults to @samp{#f}.
17556 @deftypevr {@code{namespace-configuration} parameter} boolean list?
17557 Show the mailboxes under this namespace with the LIST command. This
17558 makes the namespace visible for clients that do not support the NAMESPACE
17559 extension. The special @code{children} value lists child mailboxes, but
17560 hides the namespace prefix.
17561 Defaults to @samp{#t}.
17564 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
17565 Namespace handles its own subscriptions. If set to @code{#f}, the
17566 parent namespace handles them. The empty prefix should always have this
17568 Defaults to @samp{#t}.
17571 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
17572 List of predefined mailboxes in this namespace.
17573 Defaults to @samp{()}.
17575 Available @code{mailbox-configuration} fields are:
17577 @deftypevr {@code{mailbox-configuration} parameter} string name
17578 Name for this mailbox.
17581 @deftypevr {@code{mailbox-configuration} parameter} string auto
17582 @samp{create} will automatically create this mailbox.
17583 @samp{subscribe} will both create and subscribe to the mailbox.
17584 Defaults to @samp{"no"}.
17587 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
17588 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
17589 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
17590 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
17591 Defaults to @samp{()}.
17598 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
17599 Base directory where to store runtime data.
17600 Defaults to @samp{"/var/run/dovecot/"}.
17603 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
17604 Greeting message for clients.
17605 Defaults to @samp{"Dovecot ready."}.
17608 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
17609 List of trusted network ranges. Connections from these IPs are
17610 allowed to override their IP addresses and ports (for logging and for
17611 authentication checks). @samp{disable-plaintext-auth} is also ignored
17612 for these networks. Typically you would specify your IMAP proxy servers
17614 Defaults to @samp{()}.
17617 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
17618 List of login access check sockets (e.g.@: tcpwrap).
17619 Defaults to @samp{()}.
17622 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
17623 Show more verbose process titles (in ps). Currently shows user name
17624 and IP address. Useful for seeing who is actually using the IMAP
17625 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
17627 Defaults to @samp{#f}.
17630 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
17631 Should all processes be killed when Dovecot master process shuts down.
17632 Setting this to @code{#f} means that Dovecot can be upgraded without
17633 forcing existing client connections to close (although that could also
17634 be a problem if the upgrade is e.g.@: due to a security fix).
17635 Defaults to @samp{#t}.
17638 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
17639 If non-zero, run mail commands via this many connections to doveadm
17640 server, instead of running them directly in the same process.
17641 Defaults to @samp{0}.
17644 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
17645 UNIX socket or host:port used for connecting to doveadm server.
17646 Defaults to @samp{"doveadm-server"}.
17649 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
17650 List of environment variables that are preserved on Dovecot startup
17651 and passed down to all of its child processes. You can also give
17652 key=value pairs to always set specific settings.
17655 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
17656 Disable LOGIN command and all other plaintext authentications unless
17657 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
17658 matches the local IP (i.e.@: you're connecting from the same computer),
17659 the connection is considered secure and plaintext authentication is
17660 allowed. See also ssl=required setting.
17661 Defaults to @samp{#t}.
17664 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
17665 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
17666 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
17667 for caching to be used.
17668 Defaults to @samp{0}.
17671 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
17672 Time to live for cached data. After TTL expires the cached record
17673 is no longer used, *except* if the main database lookup returns internal
17674 failure. We also try to handle password changes automatically: If
17675 user's previous authentication was successful, but this one wasn't, the
17676 cache isn't used. For now this works only with plaintext
17678 Defaults to @samp{"1 hour"}.
17681 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
17682 TTL for negative hits (user not found, password mismatch).
17683 0 disables caching them completely.
17684 Defaults to @samp{"1 hour"}.
17687 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
17688 List of realms for SASL authentication mechanisms that need them.
17689 You can leave it empty if you don't want to support multiple realms.
17690 Many clients simply use the first one listed here, so keep the default
17692 Defaults to @samp{()}.
17695 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
17696 Default realm/domain to use if none was specified. This is used for
17697 both SASL realms and appending @@domain to username in plaintext
17699 Defaults to @samp{""}.
17702 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
17703 List of allowed characters in username. If the user-given username
17704 contains a character not listed in here, the login automatically fails.
17705 This is just an extra check to make sure user can't exploit any
17706 potential quote escaping vulnerabilities with SQL/LDAP databases. If
17707 you want to allow all characters, set this value to empty.
17708 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
17711 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
17712 Username character translations before it's looked up from
17713 databases. The value contains series of from -> to characters. For
17714 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
17715 translated to @samp{@@}.
17716 Defaults to @samp{""}.
17719 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
17720 Username formatting before it's looked up from databases. You can
17721 use the standard variables here, e.g.@: %Lu would lowercase the username,
17722 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
17723 change the @samp{@@} into @samp{-AT-}. This translation is done after
17724 @samp{auth-username-translation} changes.
17725 Defaults to @samp{"%Lu"}.
17728 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
17729 If you want to allow master users to log in by specifying the master
17730 username within the normal username string (i.e.@: not using SASL
17731 mechanism's support for it), you can specify the separator character
17732 here. The format is then <username><separator><master username>.
17733 UW-IMAP uses @samp{*} as the separator, so that could be a good
17735 Defaults to @samp{""}.
17738 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
17739 Username to use for users logging in with ANONYMOUS SASL
17741 Defaults to @samp{"anonymous"}.
17744 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
17745 Maximum number of dovecot-auth worker processes. They're used to
17746 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
17747 They're automatically created and destroyed as needed.
17748 Defaults to @samp{30}.
17751 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
17752 Host name to use in GSSAPI principal names. The default is to use
17753 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
17754 allow all keytab entries.
17755 Defaults to @samp{""}.
17758 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
17759 Kerberos keytab to use for the GSSAPI mechanism. Will use the
17760 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
17761 need to change the auth service to run as root to be able to read this
17763 Defaults to @samp{""}.
17766 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
17767 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
17768 and @samp{ntlm-auth} helper.
17769 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
17770 Defaults to @samp{#f}.
17773 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
17774 Path for Samba's @samp{ntlm-auth} helper binary.
17775 Defaults to @samp{"/usr/bin/ntlm_auth"}.
17778 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
17779 Time to delay before replying to failed authentications.
17780 Defaults to @samp{"2 secs"}.
17783 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
17784 Require a valid SSL client certificate or the authentication
17786 Defaults to @samp{#f}.
17789 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
17790 Take the username from client's SSL certificate, using
17791 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
17793 Defaults to @samp{#f}.
17796 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
17797 List of wanted authentication mechanisms. Supported mechanisms are:
17798 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
17799 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
17800 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
17801 @samp{disable-plaintext-auth} setting.
17804 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
17805 List of IPs or hostnames to all director servers, including ourself.
17806 Ports can be specified as ip:port. The default port is the same as what
17807 director service's @samp{inet-listener} is using.
17808 Defaults to @samp{()}.
17811 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
17812 List of IPs or hostnames to all backend mail servers. Ranges are
17813 allowed too, like 10.0.0.10-10.0.0.30.
17814 Defaults to @samp{()}.
17817 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
17818 How long to redirect users to a specific server after it no longer
17819 has any connections.
17820 Defaults to @samp{"15 min"}.
17823 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
17824 How the username is translated before being hashed. Useful values
17825 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
17826 are shared within domain.
17827 Defaults to @samp{"%Lu"}.
17830 @deftypevr {@code{dovecot-configuration} parameter} string log-path
17831 Log file to use for error messages. @samp{syslog} logs to syslog,
17832 @samp{/dev/stderr} logs to stderr.
17833 Defaults to @samp{"syslog"}.
17836 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
17837 Log file to use for informational messages. Defaults to
17839 Defaults to @samp{""}.
17842 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
17843 Log file to use for debug messages. Defaults to
17844 @samp{info-log-path}.
17845 Defaults to @samp{""}.
17848 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
17849 Syslog facility to use if you're logging to syslog. Usually if you
17850 don't want to use @samp{mail}, you'll use local0..local7. Also other
17851 standard facilities are supported.
17852 Defaults to @samp{"mail"}.
17855 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
17856 Log unsuccessful authentication attempts and the reasons why they
17858 Defaults to @samp{#f}.
17861 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
17862 In case of password mismatches, log the attempted password. Valid
17863 values are no, plain and sha1. sha1 can be useful for detecting brute
17864 force password attempts vs. user simply trying the same password over
17865 and over again. You can also truncate the value to n chars by appending
17866 ":n" (e.g.@: sha1:6).
17867 Defaults to @samp{"no"}.
17870 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
17871 Even more verbose logging for debugging purposes. Shows for example
17873 Defaults to @samp{#f}.
17876 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
17877 In case of password mismatches, log the passwords and used scheme so
17878 the problem can be debugged. Enabling this also enables
17880 Defaults to @samp{#f}.
17883 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
17884 Enable mail process debugging. This can help you figure out why
17885 Dovecot isn't finding your mails.
17886 Defaults to @samp{#f}.
17889 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
17890 Show protocol level SSL errors.
17891 Defaults to @samp{#f}.
17894 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
17895 Prefix for each line written to log file. % codes are in
17896 strftime(3) format.
17897 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
17900 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
17901 List of elements we want to log. The elements which have a
17902 non-empty variable value are joined together to form a comma-separated
17906 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
17907 Login log format. %s contains @samp{login-log-format-elements}
17908 string, %$ contains the data we want to log.
17909 Defaults to @samp{"%$: %s"}.
17912 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
17913 Log prefix for mail processes. See doc/wiki/Variables.txt for list
17914 of possible variables you can use.
17915 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
17918 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
17919 Format to use for logging mail deliveries. You can use variables:
17922 Delivery status message (e.g.@: @samp{saved to INBOX})
17934 Defaults to @samp{"msgid=%m: %$"}.
17937 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
17938 Location for users' mailboxes. The default is empty, which means
17939 that Dovecot tries to find the mailboxes automatically. This won't work
17940 if the user doesn't yet have any mail, so you should explicitly tell
17941 Dovecot the full location.
17943 If you're using mbox, giving a path to the INBOX
17944 file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
17945 where the other mailboxes are kept. This is called the @emph{root mail
17946 directory}, and it must be the first path given in the
17947 @samp{mail-location} setting.
17949 There are a few special variables you can use, e.g.:
17955 user part in user@@domain, same as %u if there's no domain
17957 domain part in user@@domain, empty if there's no domain
17962 See doc/wiki/Variables.txt for full list. Some examples:
17964 @item maildir:~/Maildir
17965 @item mbox:~/mail:INBOX=/var/mail/%u
17966 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
17968 Defaults to @samp{""}.
17971 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
17972 System user and group used to access mails. If you use multiple,
17973 userdb can override these by returning uid or gid fields. You can use
17974 either numbers or names. <doc/wiki/UserIds.txt>.
17975 Defaults to @samp{""}.
17978 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
17980 Defaults to @samp{""}.
17983 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
17984 Group to enable temporarily for privileged operations. Currently
17985 this is used only with INBOX when either its initial creation or
17986 dotlocking fails. Typically this is set to @samp{"mail"} to give access to
17988 Defaults to @samp{""}.
17991 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
17992 Grant access to these supplementary groups for mail processes.
17993 Typically these are used to set up access to shared mailboxes. Note
17994 that it may be dangerous to set these if users can create symlinks
17995 (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
17996 could allow a user to delete others' mailboxes, or @code{ln -s
17997 /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
18001 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
18002 Allow full file system access to clients. There's no access checks
18003 other than what the operating system does for the active UID/GID. It
18004 works with both maildir and mboxes, allowing you to prefix mailboxes
18005 names with e.g.@: @file{/path/} or @file{~user/}.
18006 Defaults to @samp{#f}.
18009 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
18010 Don't use @code{mmap()} at all. This is required if you store indexes to
18011 shared file systems (NFS or clustered file system).
18012 Defaults to @samp{#f}.
18015 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
18016 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
18017 supports @samp{O_EXCL} since version 3, so this should be safe to use
18018 nowadays by default.
18019 Defaults to @samp{#t}.
18022 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
18023 When to use fsync() or fdatasync() calls:
18026 Whenever necessary to avoid losing important data
18028 Useful with e.g.@: NFS when @code{write()}s are delayed
18030 Never use it (best performance, but crashes can lose data).
18032 Defaults to @samp{"optimized"}.
18035 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
18036 Mail storage exists in NFS. Set this to yes to make Dovecot flush
18037 NFS caches whenever needed. If you're using only a single mail server
18039 Defaults to @samp{#f}.
18042 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
18043 Mail index files also exist in NFS. Setting this to yes requires
18044 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
18045 Defaults to @samp{#f}.
18048 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
18049 Locking method for index files. Alternatives are fcntl, flock and
18050 dotlock. Dotlocking uses some tricks which may create more disk I/O
18051 than other locking methods. NFS users: flock doesn't work, remember to
18052 change @samp{mmap-disable}.
18053 Defaults to @samp{"fcntl"}.
18056 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
18057 Directory in which LDA/LMTP temporarily stores incoming mails >128
18059 Defaults to @samp{"/tmp"}.
18062 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
18063 Valid UID range for users. This is mostly to make sure that users can't
18064 log in as daemons or other system users. Note that denying root logins is
18065 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
18067 Defaults to @samp{500}.
18070 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
18072 Defaults to @samp{0}.
18075 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
18076 Valid GID range for users. Users having non-valid GID as primary group ID
18077 aren't allowed to log in. If user belongs to supplementary groups with
18078 non-valid GIDs, those groups are not set.
18079 Defaults to @samp{1}.
18082 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
18084 Defaults to @samp{0}.
18087 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
18088 Maximum allowed length for mail keyword name. It's only forced when
18089 trying to create new keywords.
18090 Defaults to @samp{50}.
18093 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
18094 List of directories under which chrooting is allowed for mail
18095 processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
18096 too). This setting doesn't affect @samp{login-chroot}
18097 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
18098 @samp{/./} in home dirs are ignored. WARNING: Never add directories here
18099 which local users can modify, that may lead to root exploit. Usually
18100 this should be done only if you don't allow shell access for users.
18101 <doc/wiki/Chrooting.txt>.
18102 Defaults to @samp{()}.
18105 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
18106 Default chroot directory for mail processes. This can be overridden
18107 for specific users in user database by giving @samp{/./} in user's home
18108 directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
18109 there is no real need to do chrooting, Dovecot doesn't allow users to
18110 access files outside their mail directory anyway. If your home
18111 directories are prefixed with the chroot directory, append @samp{/.} to
18112 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
18113 Defaults to @samp{""}.
18116 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
18117 UNIX socket path to master authentication server to find users.
18118 This is used by imap (for shared users) and lda.
18119 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
18122 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
18123 Directory where to look up mail plugins.
18124 Defaults to @samp{"/usr/lib/dovecot"}.
18127 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
18128 List of plugins to load for all services. Plugins specific to IMAP,
18129 LDA, etc.@: are added to this list in their own .conf files.
18130 Defaults to @samp{()}.
18133 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
18134 The minimum number of mails in a mailbox before updates are done to
18135 cache file. This allows optimizing Dovecot's behavior to do less disk
18136 writes at the cost of more disk reads.
18137 Defaults to @samp{0}.
18140 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
18141 When IDLE command is running, mailbox is checked once in a while to
18142 see if there are any new mails or other changes. This setting defines
18143 the minimum time to wait between those checks. Dovecot can also use
18144 dnotify, inotify and kqueue to find out immediately when changes
18146 Defaults to @samp{"30 secs"}.
18149 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
18150 Save mails with CR+LF instead of plain LF. This makes sending those
18151 mails take less CPU, especially with sendfile() syscall with Linux and
18152 FreeBSD. But it also creates a bit more disk I/O which may just make it
18153 slower. Also note that if other software reads the mboxes/maildirs,
18154 they may handle the extra CRs wrong and cause problems.
18155 Defaults to @samp{#f}.
18158 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
18159 By default LIST command returns all entries in maildir beginning
18160 with a dot. Enabling this option makes Dovecot return only entries
18161 which are directories. This is done by stat()ing each entry, so it
18162 causes more disk I/O.
18163 (For systems setting struct @samp{dirent->d_type} this check is free
18164 and it's done always regardless of this setting).
18165 Defaults to @samp{#f}.
18168 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
18169 When copying a message, do it with hard links whenever possible.
18170 This makes the performance much better, and it's unlikely to have any
18172 Defaults to @samp{#t}.
18175 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
18176 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
18177 directory only when its mtime changes unexpectedly or when we can't find
18178 the mail otherwise.
18179 Defaults to @samp{#f}.
18182 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
18183 Which locking methods to use for locking mbox. There are four
18188 Create <mailbox>.lock file. This is the oldest and most NFS-safe
18189 solution. If you want to use /var/mail/ like directory, the users will
18190 need write access to that directory.
18192 Same as dotlock, but if it fails because of permissions or because there
18193 isn't enough disk space, just skip it.
18195 Use this if possible. Works with NFS too if lockd is used.
18197 May not exist in all systems. Doesn't work with NFS.
18199 May not exist in all systems. Doesn't work with NFS.
18202 You can use multiple locking methods; if you do the order they're declared
18203 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
18204 locking methods as well. Some operating systems don't allow using some of
18205 them simultaneously.
18208 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
18212 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
18213 Maximum time to wait for lock (all of them) before aborting.
18214 Defaults to @samp{"5 mins"}.
18217 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
18218 If dotlock exists but the mailbox isn't modified in any way,
18219 override the lock file after this much time.
18220 Defaults to @samp{"2 mins"}.
18223 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
18224 When mbox changes unexpectedly we have to fully read it to find out
18225 what changed. If the mbox is large this can take a long time. Since
18226 the change is usually just a newly appended mail, it'd be faster to
18227 simply read the new mails. If this setting is enabled, Dovecot does
18228 this but still safely fallbacks to re-reading the whole mbox file
18229 whenever something in mbox isn't how it's expected to be. The only real
18230 downside to this setting is that if some other MUA changes message
18231 flags, Dovecot doesn't notice it immediately. Note that a full sync is
18232 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
18233 Defaults to @samp{#t}.
18236 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
18237 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
18238 EXAMINE, EXPUNGE or CHECK commands. If this is set,
18239 @samp{mbox-dirty-syncs} is ignored.
18240 Defaults to @samp{#f}.
18243 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
18244 Delay writing mbox headers until doing a full write sync (EXPUNGE
18245 and CHECK commands and when closing the mailbox). This is especially
18246 useful for POP3 where clients often delete all mails. The downside is
18247 that our changes aren't immediately visible to other MUAs.
18248 Defaults to @samp{#t}.
18251 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
18252 If mbox size is smaller than this (e.g.@: 100k), don't write index
18253 files. If an index file already exists it's still read, just not
18255 Defaults to @samp{0}.
18258 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
18259 Maximum dbox file size until it's rotated.
18260 Defaults to @samp{10000000}.
18263 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
18264 Maximum dbox file age until it's rotated. Typically in days. Day
18265 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
18267 Defaults to @samp{"1d"}.
18270 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
18271 When creating new mdbox files, immediately preallocate their size to
18272 @samp{mdbox-rotate-size}. This setting currently works only in Linux
18273 with some file systems (ext4, xfs).
18274 Defaults to @samp{#f}.
18277 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
18278 sdbox and mdbox support saving mail attachments to external files,
18279 which also allows single instance storage for them. Other backends
18280 don't support this for now.
18282 WARNING: This feature hasn't been tested much yet. Use at your own risk.
18284 Directory root where to store mail attachments. Disabled, if empty.
18285 Defaults to @samp{""}.
18288 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
18289 Attachments smaller than this aren't saved externally. It's also
18290 possible to write a plugin to disable saving specific attachments
18292 Defaults to @samp{128000}.
18295 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
18296 File system backend to use for saving attachments:
18299 No SiS done by Dovecot (but this might help FS's own deduplication)
18301 SiS with immediate byte-by-byte comparison during saving
18302 @item sis-queue posix
18303 SiS with delayed comparison and deduplication.
18305 Defaults to @samp{"sis posix"}.
18308 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
18309 Hash format to use in attachment filenames. You can add any text and
18310 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
18311 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
18312 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
18313 Defaults to @samp{"%@{sha1@}"}.
18316 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
18318 Defaults to @samp{100}.
18321 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
18323 Defaults to @samp{1000}.
18326 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
18327 Default VSZ (virtual memory size) limit for service processes.
18328 This is mainly intended to catch and kill processes that leak memory
18329 before they eat up everything.
18330 Defaults to @samp{256000000}.
18333 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
18334 Login user is internally used by login processes. This is the most
18335 untrusted user in Dovecot system. It shouldn't have access to anything
18337 Defaults to @samp{"dovenull"}.
18340 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
18341 Internal user is used by unprivileged processes. It should be
18342 separate from login user, so that login processes can't disturb other
18344 Defaults to @samp{"dovecot"}.
18347 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
18348 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
18349 Defaults to @samp{"required"}.
18352 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
18353 PEM encoded X.509 SSL/TLS certificate (public key).
18354 Defaults to @samp{"</etc/dovecot/default.pem"}.
18357 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
18358 PEM encoded SSL/TLS private key. The key is opened before
18359 dropping root privileges, so keep the key file unreadable by anyone but
18361 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
18364 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
18365 If key file is password protected, give the password here.
18366 Alternatively give it when starting dovecot with -p parameter. Since
18367 this file is often world-readable, you may want to place this setting
18368 instead to a different.
18369 Defaults to @samp{""}.
18372 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
18373 PEM encoded trusted certificate authority. Set this only if you
18374 intend to use @samp{ssl-verify-client-cert? #t}. The file should
18375 contain the CA certificate(s) followed by the matching
18376 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
18377 Defaults to @samp{""}.
18380 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
18381 Require that CRL check succeeds for client certificates.
18382 Defaults to @samp{#t}.
18385 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
18386 Request client to send a certificate. If you also want to require
18387 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
18388 Defaults to @samp{#f}.
18391 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
18392 Which field from certificate to use for username. commonName and
18393 x500UniqueIdentifier are the usual choices. You'll also need to set
18394 @samp{auth-ssl-username-from-cert? #t}.
18395 Defaults to @samp{"commonName"}.
18398 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
18399 Minimum SSL protocol version to accept.
18400 Defaults to @samp{"TLSv1"}.
18403 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
18404 SSL ciphers to use.
18405 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
18408 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
18409 SSL crypto device to use, for valid values run "openssl engine".
18410 Defaults to @samp{""}.
18413 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
18414 Address to use when sending rejection mails.
18415 %d expands to recipient domain.
18416 Defaults to @samp{"postmaster@@%d"}.
18419 @deftypevr {@code{dovecot-configuration} parameter} string hostname
18420 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
18421 and in LMTP replies. Default is the system's real hostname@@domain.
18422 Defaults to @samp{""}.
18425 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
18426 If user is over quota, return with temporary failure instead of
18428 Defaults to @samp{#f}.
18431 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
18432 Binary to use for sending mails.
18433 Defaults to @samp{"/usr/sbin/sendmail"}.
18436 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
18437 If non-empty, send mails via this SMTP host[:port] instead of
18439 Defaults to @samp{""}.
18442 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
18443 Subject: header to use for rejection mails. You can use the same
18444 variables as for @samp{rejection-reason} below.
18445 Defaults to @samp{"Rejected: %s"}.
18448 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
18449 Human readable error message for rejection mails. You can use
18462 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
18465 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
18466 Delimiter character between local-part and detail in email
18468 Defaults to @samp{"+"}.
18471 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
18472 Header where the original recipient address (SMTP's RCPT TO:
18473 address) is taken from if not available elsewhere. With dovecot-lda -a
18474 parameter overrides this. A commonly used header for this is
18476 Defaults to @samp{""}.
18479 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
18480 Should saving a mail to a nonexistent mailbox automatically create
18482 Defaults to @samp{#f}.
18485 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
18486 Should automatically created mailboxes be also automatically
18488 Defaults to @samp{#f}.
18491 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
18492 Maximum IMAP command line length. Some clients generate very long
18493 command lines with huge mailboxes, so you may need to raise this if you
18494 get "Too long argument" or "IMAP command line too large" errors
18496 Defaults to @samp{64000}.
18499 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
18500 IMAP logout format string:
18503 total number of bytes read from client
18505 total number of bytes sent to client.
18507 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
18508 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@}"}.
18511 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
18512 Override the IMAP CAPABILITY response. If the value begins with '+',
18513 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
18514 Defaults to @samp{""}.
18517 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
18518 How long to wait between "OK Still here" notifications when client
18520 Defaults to @samp{"2 mins"}.
18523 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
18524 ID field names and values to send to clients. Using * as the value
18525 makes Dovecot use the default value. The following fields have default
18526 values currently: name, version, os, os-version, support-url,
18528 Defaults to @samp{""}.
18531 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
18532 ID fields sent by client to log. * means everything.
18533 Defaults to @samp{""}.
18536 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
18537 Workarounds for various client bugs:
18540 @item delay-newmail
18541 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
18542 CHECK commands. Some clients ignore them otherwise, for example OSX
18543 Mail (<v2.1). Outlook Express breaks more badly though, without this it
18544 may show user "Message no longer in server" errors. Note that OE6
18545 still breaks even with this workaround if synchronization is set to
18548 @item tb-extra-mailbox-sep
18549 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
18550 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
18551 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
18553 @item tb-lsub-flags
18554 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
18555 This makes Thunderbird realize they aren't selectable and show them
18556 greyed out, instead of only later giving "not selectable" popup error.
18558 Defaults to @samp{()}.
18561 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
18562 Host allowed in URLAUTH URLs sent by client. "*" allows all.
18563 Defaults to @samp{""}.
18567 Whew! Lots of configuration options. The nice thing about it though is
18568 that Guix has a complete interface to Dovecot's configuration
18569 language. This allows not only a nice way to declare configurations,
18570 but also offers reflective capabilities as well: users can write code to
18571 inspect and transform configurations from within Scheme.
18573 However, it could be that you just want to get a @code{dovecot.conf} up
18574 and running. In that case, you can pass an
18575 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
18576 @code{dovecot-service}. As its name indicates, an opaque configuration
18577 does not have easy reflective capabilities.
18579 Available @code{opaque-dovecot-configuration} fields are:
18581 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
18582 The dovecot package.
18585 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
18586 The contents of the @code{dovecot.conf}, as a string.
18589 For example, if your @code{dovecot.conf} is just the empty string, you
18590 could instantiate a dovecot service like this:
18593 (dovecot-service #:config
18594 (opaque-dovecot-configuration
18598 @subsubheading OpenSMTPD Service
18600 @deffn {Scheme Variable} opensmtpd-service-type
18601 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
18602 service, whose value should be an @code{opensmtpd-configuration} object
18603 as in this example:
18606 (service opensmtpd-service-type
18607 (opensmtpd-configuration
18608 (config-file (local-file "./my-smtpd.conf"))))
18612 @deftp {Data Type} opensmtpd-configuration
18613 Data type representing the configuration of opensmtpd.
18616 @item @code{package} (default: @var{opensmtpd})
18617 Package object of the OpenSMTPD SMTP server.
18619 @item @code{config-file} (default: @code{%default-opensmtpd-file})
18620 File-like object of the OpenSMTPD configuration file to use. By default
18621 it listens on the loopback network interface, and allows for mail from
18622 users and daemons on the local machine, as well as permitting email to
18623 remote servers. Run @command{man smtpd.conf} for more information.
18628 @subsubheading Exim Service
18630 @cindex mail transfer agent (MTA)
18631 @cindex MTA (mail transfer agent)
18634 @deffn {Scheme Variable} exim-service-type
18635 This is the type of the @uref{https://exim.org, Exim} mail transfer
18636 agent (MTA), whose value should be an @code{exim-configuration} object
18637 as in this example:
18640 (service exim-service-type
18641 (exim-configuration
18642 (config-file (local-file "./my-exim.conf"))))
18646 In order to use an @code{exim-service-type} service you must also have a
18647 @code{mail-aliases-service-type} service present in your
18648 @code{operating-system} (even if it has no aliases).
18650 @deftp {Data Type} exim-configuration
18651 Data type representing the configuration of exim.
18654 @item @code{package} (default: @var{exim})
18655 Package object of the Exim server.
18657 @item @code{config-file} (default: @code{#f})
18658 File-like object of the Exim configuration file to use. If its value is
18659 @code{#f} then use the default configuration file from the package
18660 provided in @code{package}. The resulting configuration file is loaded
18661 after setting the @code{exim_user} and @code{exim_group} configuration
18667 @subsubheading Getmail service
18672 @deffn {Scheme Variable} getmail-service-type
18673 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
18674 mail retriever, whose value should be an @code{getmail-configuration}.
18677 Available @code{getmail-configuration} fields are:
18679 @deftypevr {@code{getmail-configuration} parameter} symbol name
18680 A symbol to identify the getmail service.
18682 Defaults to @samp{"unset"}.
18686 @deftypevr {@code{getmail-configuration} parameter} package package
18687 The getmail package to use.
18691 @deftypevr {@code{getmail-configuration} parameter} string user
18692 The user to run getmail as.
18694 Defaults to @samp{"getmail"}.
18698 @deftypevr {@code{getmail-configuration} parameter} string group
18699 The group to run getmail as.
18701 Defaults to @samp{"getmail"}.
18705 @deftypevr {@code{getmail-configuration} parameter} string directory
18706 The getmail directory to use.
18708 Defaults to @samp{"/var/lib/getmail/default"}.
18712 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
18713 The getmail configuration file to use.
18715 Available @code{getmail-configuration-file} fields are:
18717 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
18718 What mail account to retrieve mail from, and how to access that account.
18720 Available @code{getmail-retriever-configuration} fields are:
18722 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
18723 The type of mail retriever to use. Valid values include @samp{passwd}
18726 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
18730 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
18731 Username to login to the mail server with.
18733 Defaults to @samp{unset}.
18737 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
18738 Username to login to the mail server with.
18740 Defaults to @samp{unset}.
18744 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
18745 Port number to connect to.
18747 Defaults to @samp{#f}.
18751 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
18752 Override fields from passwd.
18754 Defaults to @samp{""}.
18758 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
18759 Override fields from passwd.
18761 Defaults to @samp{()}.
18765 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
18766 PEM-formatted key file to use for the TLS negotiation.
18768 Defaults to @samp{""}.
18772 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
18773 PEM-formatted certificate file to use for the TLS negotiation.
18775 Defaults to @samp{""}.
18779 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
18780 CA certificates to use.
18782 Defaults to @samp{""}.
18786 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
18787 Extra retriever parameters.
18789 Defaults to @samp{()}.
18795 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
18796 What to do with retrieved messages.
18798 Available @code{getmail-destination-configuration} fields are:
18800 @deftypevr {@code{getmail-destination-configuration} parameter} string type
18801 The type of mail destination. Valid values include @samp{Maildir},
18802 @samp{Mboxrd} and @samp{MDA_external}.
18804 Defaults to @samp{unset}.
18808 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
18809 The path option for the mail destination. The behaviour depends on the
18812 Defaults to @samp{""}.
18816 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
18817 Extra destination parameters
18819 Defaults to @samp{()}.
18825 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
18828 Available @code{getmail-options-configuration} fields are:
18830 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
18831 If set to @samp{0}, getmail will only print warnings and errors. A
18832 value of @samp{1} means that messages will be printed about retrieving
18833 and deleting messages. If set to @samp{2}, getmail will print messages
18834 about each of it's actions.
18836 Defaults to @samp{1}.
18840 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
18841 If true, getmail will retrieve all available messages. Otherwise it
18842 will only retrieve messages it hasn't seen previously.
18844 Defaults to @samp{#t}.
18848 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
18849 If set to true, messages will be deleted from the server after
18850 retrieving and successfully delivering them. Otherwise, messages will
18851 be left on the server.
18853 Defaults to @samp{#f}.
18857 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
18858 Getmail will delete messages this number of days after seeing them, if
18859 they have been delivered. This means messages will be left on the
18860 server this number of days after delivering them. A value of @samp{0}
18861 disabled this feature.
18863 Defaults to @samp{0}.
18867 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
18868 Delete messages larger than this of bytes after retrieving them, even if
18869 the delete and delete-after options are disabled. A value of @samp{0}
18870 disables this feature.
18872 Defaults to @samp{0}.
18876 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
18877 Retrieve messages totalling up to this number of bytes before closing
18878 the session with the server. A value of @samp{0} disables this feature.
18880 Defaults to @samp{0}.
18884 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
18885 Don't retrieve messages larger than this number of bytes. A value of
18886 @samp{0} disables this feature.
18888 Defaults to @samp{0}.
18892 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
18893 If true, getmail will add a Delivered-To header to messages.
18895 Defaults to @samp{#t}.
18899 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
18900 If set, getmail adds a Received header to the messages.
18902 Defaults to @samp{#t}.
18906 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
18907 Getmail will record a log of its actions to the named file. A value of
18908 @samp{""} disables this feature.
18910 Defaults to @samp{""}.
18914 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
18915 If true, getmail will record a log of its actions using the system
18918 Defaults to @samp{#f}.
18922 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
18923 If true, getmail will log information about messages not retrieved and
18924 the reason for not retrieving them, as well as starting and ending
18927 Defaults to @samp{#f}.
18931 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
18932 Extra options to include.
18934 Defaults to @samp{()}.
18942 @deftypevr {@code{getmail-configuration} parameter} list idle
18943 A list of mailboxes that getmail should wait on the server for new mail
18944 notifications. This depends on the server supporting the IDLE
18947 Defaults to @samp{()}.
18951 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
18952 Environment variables to set for getmail.
18954 Defaults to @samp{()}.
18958 @subsubheading Mail Aliases Service
18960 @cindex email aliases
18961 @cindex aliases, for email addresses
18963 @deffn {Scheme Variable} mail-aliases-service-type
18964 This is the type of the service which provides @code{/etc/aliases},
18965 specifying how to deliver mail to users on this system.
18968 (service mail-aliases-service-type
18969 '(("postmaster" "bob")
18970 ("bob" "bob@@example.com" "bob@@example2.com")))
18974 The configuration for a @code{mail-aliases-service-type} service is an
18975 association list denoting how to deliver mail that comes to this
18976 system. Each entry is of the form @code{(alias addresses ...)}, with
18977 @code{alias} specifying the local alias and @code{addresses} specifying
18978 where to deliver this user's mail.
18980 The aliases aren't required to exist as users on the local system. In
18981 the above example, there doesn't need to be a @code{postmaster} entry in
18982 the @code{operating-system}'s @code{user-accounts} in order to deliver
18983 the @code{postmaster} mail to @code{bob} (which subsequently would
18984 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
18986 @subsubheading GNU Mailutils IMAP4 Daemon
18987 @cindex GNU Mailutils IMAP4 Daemon
18989 @deffn {Scheme Variable} imap4d-service-type
18990 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
18991 mailutils, GNU Mailutils Manual}), whose value should be an
18992 @code{imap4d-configuration} object as in this example:
18995 (service imap4d-service-type
18996 (imap4d-configuration
18997 (config-file (local-file "imap4d.conf"))))
19001 @deftp {Data Type} imap4d-configuration
19002 Data type representing the configuration of @command{imap4d}.
19005 @item @code{package} (default: @code{mailutils})
19006 The package that provides @command{imap4d}.
19008 @item @code{config-file} (default: @code{%default-imap4d-config-file})
19009 File-like object of the configuration file to use, by default it will listen
19010 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
19011 Mailutils Manual}, for details.
19016 @node Messaging Services
19017 @subsection Messaging Services
19022 The @code{(gnu services messaging)} module provides Guix service
19023 definitions for messaging services: currently only Prosody is supported.
19025 @subsubheading Prosody Service
19027 @deffn {Scheme Variable} prosody-service-type
19028 This is the type for the @uref{https://prosody.im, Prosody XMPP
19029 communication server}. Its value must be a @code{prosody-configuration}
19030 record as in this example:
19033 (service prosody-service-type
19034 (prosody-configuration
19035 (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
19038 (int-component-configuration
19039 (hostname "conference.example.net")
19041 (mod-muc (mod-muc-configuration)))))
19044 (virtualhost-configuration
19045 (domain "example.net"))))))
19048 See below for details about @code{prosody-configuration}.
19052 By default, Prosody does not need much configuration. Only one
19053 @code{virtualhosts} field is needed: it specifies the domain you wish
19056 You can perform various sanity checks on the generated configuration
19057 with the @code{prosodyctl check} command.
19059 Prosodyctl will also help you to import certificates from the
19060 @code{letsencrypt} directory so that the @code{prosody} user can access
19061 them. See @url{https://prosody.im/doc/letsencrypt}.
19064 prosodyctl --root cert import /etc/letsencrypt/live
19067 The available configuration parameters follow. Each parameter
19068 definition is preceded by its type; for example, @samp{string-list foo}
19069 indicates that the @code{foo} parameter should be specified as a list of
19070 strings. Types starting with @code{maybe-} denote parameters that won't
19071 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
19073 There is also a way to specify the configuration as a string, if you
19074 have an old @code{prosody.cfg.lua} file that you want to port over from
19075 some other system; see the end for more details.
19077 The @code{file-object} type designates either a file-like object
19078 (@pxref{G-Expressions, file-like objects}) or a file name.
19080 @c The following documentation was initially generated by
19081 @c (generate-documentation) in (gnu services messaging). Manually maintained
19082 @c documentation is better, so we shouldn't hesitate to edit below as
19083 @c needed. However if the change you want to make to this documentation
19084 @c can be done in an automated way, it's probably easier to change
19085 @c (generate-documentation) than to make it below and have to deal with
19086 @c the churn as Prosody updates.
19088 Available @code{prosody-configuration} fields are:
19090 @deftypevr {@code{prosody-configuration} parameter} package prosody
19091 The Prosody package.
19094 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
19095 Location of the Prosody data storage directory. See
19096 @url{https://prosody.im/doc/configure}.
19097 Defaults to @samp{"/var/lib/prosody"}.
19100 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
19101 Additional plugin directories. They are searched in all the specified
19102 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
19103 Defaults to @samp{()}.
19106 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
19107 Every virtual host and component needs a certificate so that clients and
19108 servers can securely verify its identity. Prosody will automatically load
19109 certificates/keys from the directory specified here.
19110 Defaults to @samp{"/etc/prosody/certs"}.
19113 @deftypevr {@code{prosody-configuration} parameter} string-list admins
19114 This is a list of accounts that are admins for the server. Note that you
19115 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
19116 @url{https://prosody.im/doc/creating_accounts}.
19117 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
19118 Defaults to @samp{()}.
19121 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
19122 Enable use of libevent for better performance under high load. See
19123 @url{https://prosody.im/doc/libevent}.
19124 Defaults to @samp{#f}.
19127 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
19128 This is the list of modules Prosody will load on startup. It looks for
19129 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
19130 Documentation on modules can be found at:
19131 @url{https://prosody.im/doc/modules}.
19132 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
19135 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
19136 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
19137 should you want to disable them then add them to this list.
19138 Defaults to @samp{()}.
19141 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
19142 Path to a text file where the shared groups are defined. If this path is
19143 empty then @samp{mod_groups} does nothing. See
19144 @url{https://prosody.im/doc/modules/mod_groups}.
19145 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
19148 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
19149 Disable account creation by default, for security. See
19150 @url{https://prosody.im/doc/creating_accounts}.
19151 Defaults to @samp{#f}.
19154 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
19155 These are the SSL/TLS-related settings. Most of them are disabled so to
19156 use Prosody's defaults. If you do not completely understand these options, do
19157 not add them to your config, it is easy to lower the security of your server
19158 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
19160 Available @code{ssl-configuration} fields are:
19162 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
19163 This determines what handshake to use.
19166 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
19167 Path to your private key file.
19170 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
19171 Path to your certificate file.
19174 @deftypevr {@code{ssl-configuration} parameter} file-object capath
19175 Path to directory containing root certificates that you wish Prosody to
19176 trust when verifying the certificates of remote servers.
19177 Defaults to @samp{"/etc/ssl/certs"}.
19180 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
19181 Path to a file containing root certificates that you wish Prosody to trust.
19182 Similar to @code{capath} but with all certificates concatenated together.
19185 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
19186 A list of verification options (these mostly map to OpenSSL's
19187 @code{set_verify()} flags).
19190 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
19191 A list of general options relating to SSL/TLS. These map to OpenSSL's
19192 @code{set_options()}. For a full list of options available in LuaSec, see the
19196 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
19197 How long a chain of certificate authorities to check when looking for a
19198 trusted root certificate.
19201 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
19202 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
19203 clients, and in what order.
19206 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
19207 A path to a file containing parameters for Diffie-Hellman key exchange. You
19208 can create such a file with:
19209 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
19212 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
19213 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
19214 @samp{"secp384r1"}.
19217 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
19218 A list of ``extra'' verification options.
19221 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
19222 Password for encrypted private keys.
19227 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
19228 Whether to force all client-to-server connections to be encrypted or not.
19229 See @url{https://prosody.im/doc/modules/mod_tls}.
19230 Defaults to @samp{#f}.
19233 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
19234 Set of mechanisms that will never be offered. See
19235 @url{https://prosody.im/doc/modules/mod_saslauth}.
19236 Defaults to @samp{("DIGEST-MD5")}.
19239 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
19240 Whether to force all server-to-server connections to be encrypted or not.
19241 See @url{https://prosody.im/doc/modules/mod_tls}.
19242 Defaults to @samp{#f}.
19245 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
19246 Whether to require encryption and certificate authentication. This
19247 provides ideal security, but requires servers you communicate with to support
19248 encryption AND present valid, trusted certificates. See
19249 @url{https://prosody.im/doc/s2s#security}.
19250 Defaults to @samp{#f}.
19253 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
19254 Many servers don't support encryption or have invalid or self-signed
19255 certificates. You can list domains here that will not be required to
19256 authenticate using certificates. They will be authenticated using DNS. See
19257 @url{https://prosody.im/doc/s2s#security}.
19258 Defaults to @samp{()}.
19261 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
19262 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
19263 valid certificates for some domains by specifying a list here. See
19264 @url{https://prosody.im/doc/s2s#security}.
19265 Defaults to @samp{()}.
19268 @deftypevr {@code{prosody-configuration} parameter} string authentication
19269 Select the authentication backend to use. The default provider stores
19270 passwords in plaintext and uses Prosody's configured data storage to store the
19271 authentication data. If you do not trust your server please see
19272 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
19273 about using the hashed backend. See also
19274 @url{https://prosody.im/doc/authentication}
19275 Defaults to @samp{"internal_plain"}.
19278 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
19279 Set logging options. Advanced logging configuration is not yet supported
19280 by the Prosody service. See @url{https://prosody.im/doc/logging}.
19281 Defaults to @samp{"*syslog"}.
19284 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
19285 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
19286 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
19289 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
19290 Maximum allowed size of the HTTP body (in bytes).
19293 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
19294 Some modules expose their own URL in various ways. This URL is built
19295 from the protocol, host and port used. If Prosody sits behind a proxy, the
19296 public URL will be @code{http-external-url} instead. See
19297 @url{https://prosody.im/doc/http#external_url}.
19300 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
19301 A host in Prosody is a domain on which user accounts can be created. For
19302 example if you want your users to have addresses like
19303 @samp{"john.smith@@example.com"} then you need to add a host
19304 @samp{"example.com"}. All options in this list will apply only to this host.
19306 Note: the name @emph{virtual} host is used in configuration to avoid confusion with
19307 the actual physical host that Prosody is installed on. A single Prosody
19308 instance can serve many domains, each one defined as a VirtualHost entry in
19309 Prosody's configuration. Conversely a server that hosts a single domain would
19310 have just one VirtualHost entry.
19312 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
19314 Available @code{virtualhost-configuration} fields are:
19316 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:
19317 @deftypevr {@code{virtualhost-configuration} parameter} string domain
19318 Domain you wish Prosody to serve.
19323 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
19324 Components are extra services on a server which are available to clients,
19325 usually on a subdomain of the main server (such as
19326 @samp{"mycomponent.example.com"}). Example components might be chatroom
19327 servers, user directories, or gateways to other protocols.
19329 Internal components are implemented with Prosody-specific plugins. To add an
19330 internal component, you simply fill the hostname field, and the plugin you wish
19331 to use for the component.
19333 See @url{https://prosody.im/doc/components}.
19334 Defaults to @samp{()}.
19336 Available @code{int-component-configuration} fields are:
19338 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:
19339 @deftypevr {@code{int-component-configuration} parameter} string hostname
19340 Hostname of the component.
19343 @deftypevr {@code{int-component-configuration} parameter} string plugin
19344 Plugin you wish to use for the component.
19347 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
19348 Multi-user chat (MUC) is Prosody's module for allowing you to create
19349 hosted chatrooms/conferences for XMPP users.
19351 General information on setting up and using multi-user chatrooms can be found
19352 in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
19353 which you should read if you are new to XMPP chatrooms.
19355 See also @url{https://prosody.im/doc/modules/mod_muc}.
19357 Available @code{mod-muc-configuration} fields are:
19359 @deftypevr {@code{mod-muc-configuration} parameter} string name
19360 The name to return in service discovery responses.
19361 Defaults to @samp{"Prosody Chatrooms"}.
19364 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
19365 If @samp{#t}, this will only allow admins to create new chatrooms.
19366 Otherwise anyone can create a room. The value @samp{"local"} restricts room
19367 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
19368 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
19369 restricts to service administrators only.
19370 Defaults to @samp{#f}.
19373 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
19374 Maximum number of history messages that will be sent to the member that has
19375 just joined the room.
19376 Defaults to @samp{20}.
19383 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
19384 External components use XEP-0114, which most standalone components
19385 support. To add an external component, you simply fill the hostname field. See
19386 @url{https://prosody.im/doc/components}.
19387 Defaults to @samp{()}.
19389 Available @code{ext-component-configuration} fields are:
19391 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:
19392 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
19393 Password which the component will use to log in.
19396 @deftypevr {@code{ext-component-configuration} parameter} string hostname
19397 Hostname of the component.
19402 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
19403 Port(s) Prosody listens on for component connections.
19404 Defaults to @samp{(5347)}.
19407 @deftypevr {@code{prosody-configuration} parameter} string component-interface
19408 Interface Prosody listens on for component connections.
19409 Defaults to @samp{"127.0.0.1"}.
19412 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
19413 Raw content that will be added to the configuration file.
19416 It could be that you just want to get a @code{prosody.cfg.lua}
19417 up and running. In that case, you can pass an
19418 @code{opaque-prosody-configuration} record as the value of
19419 @code{prosody-service-type}. As its name indicates, an opaque configuration
19420 does not have easy reflective capabilities.
19421 Available @code{opaque-prosody-configuration} fields are:
19423 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
19424 The prosody package.
19427 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
19428 The contents of the @code{prosody.cfg.lua} to use.
19431 For example, if your @code{prosody.cfg.lua} is just the empty
19432 string, you could instantiate a prosody service like this:
19435 (service prosody-service-type
19436 (opaque-prosody-configuration
19437 (prosody.cfg.lua "")))
19440 @c end of Prosody auto-generated documentation
19442 @subsubheading BitlBee Service
19444 @cindex IRC (Internet Relay Chat)
19445 @cindex IRC gateway
19446 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
19447 interface to a variety of messaging protocols such as XMPP.
19449 @defvr {Scheme Variable} bitlbee-service-type
19450 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
19451 gateway daemon. Its value is a @code{bitlbee-configuration} (see
19454 To have BitlBee listen on port 6667 on localhost, add this line to your
19458 (service bitlbee-service-type)
19462 @deftp {Data Type} bitlbee-configuration
19463 This is the configuration for BitlBee, with the following fields:
19466 @item @code{interface} (default: @code{"127.0.0.1"})
19467 @itemx @code{port} (default: @code{6667})
19468 Listen on the network interface corresponding to the IP address
19469 specified in @var{interface}, on @var{port}.
19471 When @var{interface} is @code{127.0.0.1}, only local clients can
19472 connect; when it is @code{0.0.0.0}, connections can come from any
19473 networking interface.
19475 @item @code{bitlbee} (default: @code{bitlbee})
19476 The BitlBee package to use.
19478 @item @code{plugins} (default: @code{'()})
19479 List of plugin packages to use---e.g., @code{bitlbee-discord}.
19481 @item @code{extra-settings} (default: @code{""})
19482 Configuration snippet added as-is to the BitlBee configuration file.
19486 @subsubheading Quassel Service
19488 @cindex IRC (Internet Relay Chat)
19489 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
19490 meaning that one or more clients can attach to and detach from the
19493 @defvr {Scheme Variable} quassel-service-type
19494 This is the service type for the @url{https://quassel-irc.org/,Quassel}
19495 IRC backend daemon. Its value is a @code{quassel-configuration}
19499 @deftp {Data Type} quassel-configuration
19500 This is the configuration for Quassel, with the following fields:
19503 @item @code{quassel} (default: @code{quassel})
19504 The Quassel package to use.
19506 @item @code{interface} (default: @code{"::,0.0.0.0"})
19507 @item @code{port} (default: @code{4242})
19508 Listen on the network interface(s) corresponding to the IPv4 or IPv6
19509 interfaces specified in the comma delimited @var{interface}, on
19512 @item @code{loglevel} (default: @code{"Info"})
19513 The level of logging desired. Accepted values are Debug, Info, Warning
19518 @node Telephony Services
19519 @subsection Telephony Services
19521 @cindex Murmur (VoIP server)
19522 @cindex VoIP server
19523 This section describes how to set up and run a Murmur server. Murmur is
19524 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
19527 @deftp {Data Type} murmur-configuration
19528 The service type for the Murmur server. An example configuration can
19532 (service murmur-service-type
19533 (murmur-configuration
19535 "Welcome to this Mumble server running on Guix!")
19536 (cert-required? #t) ;disallow text password logins
19537 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
19538 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
19541 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
19542 password with the command that is printed during the activation phase.
19544 It is recommended to register a normal Mumble user account
19545 and grant it admin or moderator rights.
19546 You can use the @code{mumble} client to
19547 login as new normal user, register yourself, and log out.
19548 For the next step login with the name @code{SuperUser} use
19549 the @code{SuperUser} password that you set previously,
19550 and grant your newly registered mumble user administrator or moderator
19551 rights and create some channels.
19553 Available @code{murmur-configuration} fields are:
19556 @item @code{package} (default: @code{mumble})
19557 Package that contains @code{bin/murmurd}.
19559 @item @code{user} (default: @code{"murmur"})
19560 User who will run the Murmur server.
19562 @item @code{group} (default: @code{"murmur"})
19563 Group of the user who will run the murmur server.
19565 @item @code{port} (default: @code{64738})
19566 Port on which the server will listen.
19568 @item @code{welcome-text} (default: @code{""})
19569 Welcome text sent to clients when they connect.
19571 @item @code{server-password} (default: @code{""})
19572 Password the clients have to enter in order to connect.
19574 @item @code{max-users} (default: @code{100})
19575 Maximum of users that can be connected to the server at once.
19577 @item @code{max-user-bandwidth} (default: @code{#f})
19578 Maximum voice traffic a user can send per second.
19580 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
19581 File name of the sqlite database.
19582 The service's user will become the owner of the directory.
19584 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
19585 File name of the log file.
19586 The service's user will become the owner of the directory.
19588 @item @code{autoban-attempts} (default: @code{10})
19589 Maximum number of logins a user can make in @code{autoban-timeframe}
19590 without getting auto banned for @code{autoban-time}.
19592 @item @code{autoban-timeframe} (default: @code{120})
19593 Timeframe for autoban in seconds.
19595 @item @code{autoban-time} (default: @code{300})
19596 Amount of time in seconds for which a client gets banned
19597 when violating the autoban limits.
19599 @item @code{opus-threshold} (default: @code{100})
19600 Percentage of clients that need to support opus
19601 before switching over to opus audio codec.
19603 @item @code{channel-nesting-limit} (default: @code{10})
19604 How deep channels can be nested at maximum.
19606 @item @code{channelname-regex} (default: @code{#f})
19607 A string in form of a Qt regular expression that channel names must conform to.
19609 @item @code{username-regex} (default: @code{#f})
19610 A string in form of a Qt regular expression that user names must conform to.
19612 @item @code{text-message-length} (default: @code{5000})
19613 Maximum size in bytes that a user can send in one text chat message.
19615 @item @code{image-message-length} (default: @code{(* 128 1024)})
19616 Maximum size in bytes that a user can send in one image message.
19618 @item @code{cert-required?} (default: @code{#f})
19619 If it is set to @code{#t} clients that use weak password authentication
19620 will not be accepted. Users must have completed the certificate wizard to join.
19622 @item @code{remember-channel?} (default: @code{#f})
19623 Should murmur remember the last channel each user was in when they disconnected
19624 and put them into the remembered channel when they rejoin.
19626 @item @code{allow-html?} (default: @code{#f})
19627 Should html be allowed in text messages, user comments, and channel descriptions.
19629 @item @code{allow-ping?} (default: @code{#f})
19630 Setting to true exposes the current user count, the maximum user count, and
19631 the server's maximum bandwidth per client to unauthenticated users. In the
19632 Mumble client, this information is shown in the Connect dialog.
19634 Disabling this setting will prevent public listing of the server.
19636 @item @code{bonjour?} (default: @code{#f})
19637 Should the server advertise itself in the local network through the bonjour protocol.
19639 @item @code{send-version?} (default: @code{#f})
19640 Should the murmur server version be exposed in ping requests.
19642 @item @code{log-days} (default: @code{31})
19643 Murmur also stores logs in the database, which are accessible via RPC.
19644 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
19645 or -1 to disable logging to the database.
19647 @item @code{obfuscate-ips?} (default: @code{#t})
19648 Should logged ips be obfuscated to protect the privacy of users.
19650 @item @code{ssl-cert} (default: @code{#f})
19651 File name of the SSL/TLS certificate used for encrypted connections.
19654 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
19656 @item @code{ssl-key} (default: @code{#f})
19657 Filepath to the ssl private key used for encrypted connections.
19659 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
19662 @item @code{ssl-dh-params} (default: @code{#f})
19663 File name of a PEM-encoded file with Diffie-Hellman parameters
19664 for the SSL/TLS encryption. Alternatively you set it to
19665 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
19666 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
19668 @item @code{ssl-ciphers} (default: @code{#f})
19669 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
19672 This option is specified using
19673 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
19674 OpenSSL cipher list notation}.
19676 It is recommended that you try your cipher string using 'openssl ciphers <string>'
19677 before setting it here, to get a feel for which cipher suites you will get.
19678 After setting this option, it is recommend that you inspect your Murmur log
19679 to ensure that Murmur is using the cipher suites that you expected it to.
19681 Note: Changing this option may impact the backwards compatibility of your
19682 Murmur server, and can remove the ability for older Mumble clients to be able
19685 @item @code{public-registration} (default: @code{#f})
19686 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
19688 You can optionally register your server in the public server list that the
19689 @code{mumble} client shows on startup.
19690 You cannot register your server if you have set a @code{server-password},
19691 or set @code{allow-ping} to @code{#f}.
19693 It might take a few hours until it shows up in the public list.
19695 @item @code{file} (default: @code{#f})
19696 Optional alternative override for this configuration.
19700 @deftp {Data Type} murmur-public-registration-configuration
19701 Configuration for public registration of a murmur service.
19705 This is a display name for your server. Not to be confused with the hostname.
19707 @item @code{password}
19708 A password to identify your registration.
19709 Subsequent updates will need the same password. Don't lose your password.
19712 This should be a @code{http://} or @code{https://} link to your web
19715 @item @code{hostname} (default: @code{#f})
19716 By default your server will be listed by its IP address.
19717 If it is set your server will be linked by this host name instead.
19723 @node Monitoring Services
19724 @subsection Monitoring Services
19726 @subsubheading Tailon Service
19728 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
19729 viewing and searching log files.
19731 The following example will configure the service with default values.
19732 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
19735 (service tailon-service-type)
19738 The following example customises more of the Tailon configuration,
19739 adding @command{sed} to the list of allowed commands.
19742 (service tailon-service-type
19743 (tailon-configuration
19745 (tailon-configuration-file
19746 (allowed-commands '("tail" "grep" "awk" "sed"))))))
19750 @deftp {Data Type} tailon-configuration
19751 Data type representing the configuration of Tailon.
19752 This type has the following parameters:
19755 @item @code{config-file} (default: @code{(tailon-configuration-file)})
19756 The configuration file to use for Tailon. This can be set to a
19757 @dfn{tailon-configuration-file} record value, or any gexp
19758 (@pxref{G-Expressions}).
19760 For example, to instead use a local file, the @code{local-file} function
19764 (service tailon-service-type
19765 (tailon-configuration
19766 (config-file (local-file "./my-tailon.conf"))))
19769 @item @code{package} (default: @code{tailon})
19770 The tailon package to use.
19775 @deftp {Data Type} tailon-configuration-file
19776 Data type representing the configuration options for Tailon.
19777 This type has the following parameters:
19780 @item @code{files} (default: @code{(list "/var/log")})
19781 List of files to display. The list can include strings for a single file
19782 or directory, or a list, where the first item is the name of a
19783 subsection, and the remaining items are the files or directories in that
19786 @item @code{bind} (default: @code{"localhost:8080"})
19787 Address and port to which Tailon should bind on.
19789 @item @code{relative-root} (default: @code{#f})
19790 URL path to use for Tailon, set to @code{#f} to not use a path.
19792 @item @code{allow-transfers?} (default: @code{#t})
19793 Allow downloading the log files in the web interface.
19795 @item @code{follow-names?} (default: @code{#t})
19796 Allow tailing of not-yet existent files.
19798 @item @code{tail-lines} (default: @code{200})
19799 Number of lines to read initially from each file.
19801 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
19802 Commands to allow running. By default, @code{sed} is disabled.
19804 @item @code{debug?} (default: @code{#f})
19805 Set @code{debug?} to @code{#t} to show debug messages.
19807 @item @code{wrap-lines} (default: @code{#t})
19808 Initial line wrapping state in the web interface. Set to @code{#t} to
19809 initially wrap lines (the default), or to @code{#f} to initially not
19812 @item @code{http-auth} (default: @code{#f})
19813 HTTP authentication type to use. Set to @code{#f} to disable
19814 authentication (the default). Supported values are @code{"digest"} or
19817 @item @code{users} (default: @code{#f})
19818 If HTTP authentication is enabled (see @code{http-auth}), access will be
19819 restricted to the credentials provided here. To configure users, use a
19820 list of pairs, where the first element of the pair is the username, and
19821 the 2nd element of the pair is the password.
19824 (tailon-configuration-file
19825 (http-auth "basic")
19826 (users '(("user1" . "password1")
19827 ("user2" . "password2"))))
19834 @subsubheading Darkstat Service
19836 Darkstat is a packet sniffer that captures network traffic, calculates
19837 statistics about usage, and serves reports over HTTP.
19839 @defvar {Scheme Variable} darkstat-service-type
19840 This is the service type for the
19841 @uref{https://unix4lyfe.org/darkstat/, darkstat}
19842 service, its value must be a @code{darkstat-configuration} record as in
19846 (service darkstat-service-type
19847 (darkstat-configuration
19848 (interface "eno1")))
19852 @deftp {Data Type} darkstat-configuration
19853 Data type representing the configuration of @command{darkstat}.
19856 @item @code{package} (default: @code{darkstat})
19857 The darkstat package to use.
19859 @item @code{interface}
19860 Capture traffic on the specified network interface.
19862 @item @code{port} (default: @code{"667"})
19863 Bind the web interface to the specified port.
19865 @item @code{bind-address} (default: @code{"127.0.0.1"})
19866 Bind the web interface to the specified address.
19868 @item @code{base} (default: @code{"/"})
19869 Specify the path of the base URL. This can be useful if
19870 @command{darkstat} is accessed via a reverse proxy.
19875 @subsubheading Prometheus Node Exporter Service
19877 @cindex prometheus-node-exporter
19878 The Prometheus ``node exporter'' makes hardware and operating system statistics
19879 provided by the Linux kernel available for the Prometheus monitoring system.
19880 This service should be deployed on all physical nodes and virtual machines,
19881 where monitoring these statistics is desirable.
19883 @defvar {Scheme variable} prometheus-node-exporter-service-type
19884 This is the service type for the
19885 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
19886 service, its value must be a @code{prometheus-node-exporter-configuration}
19887 record as in this example:
19890 (service prometheus-node-exporter-service-type
19891 (prometheus-node-exporter-configuration
19892 (web-listen-address ":9100")))
19896 @deftp {Data Type} prometheus-node-exporter-configuration
19897 Data type representing the configuration of @command{node_exporter}.
19900 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
19901 The prometheus-node-exporter package to use.
19903 @item @code{web-listen-address} (default: @code{":9100"})
19904 Bind the web interface to the specified address.
19909 @subsubheading Zabbix server
19910 @cindex zabbix zabbix-server
19911 Zabbix provides monitoring metrics, among others network utilization, CPU load
19912 and disk space consumption:
19915 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
19916 @item Auto-discovery of servers and network devices and interfaces.
19917 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
19918 @item Distributed monitoring with centralized web administration.
19919 @item Native high performance agents.
19920 @item SLA, and ITIL KPI metrics on reporting.
19921 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
19922 @item Remote command execution through Zabbix proxies.
19925 @c %start of fragment
19927 Available @code{zabbix-server-configuration} fields are:
19929 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
19930 The zabbix-server package.
19934 @deftypevr {@code{zabbix-server-configuration} parameter} string user
19935 User who will run the Zabbix server.
19937 Defaults to @samp{"zabbix"}.
19941 @deftypevr {@code{zabbix-server-configuration} parameter} group group
19942 Group who will run the Zabbix server.
19944 Defaults to @samp{"zabbix"}.
19948 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
19949 Database host name.
19951 Defaults to @samp{"127.0.0.1"}.
19955 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
19958 Defaults to @samp{"zabbix"}.
19962 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
19965 Defaults to @samp{"zabbix"}.
19969 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
19970 Database password. Please, use @code{include-files} with
19971 @code{DBPassword=SECRET} inside a specified file instead.
19973 Defaults to @samp{""}.
19977 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
19980 Defaults to @samp{5432}.
19984 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
19985 Specifies where log messages are written to:
19989 @code{system} - syslog.
19992 @code{file} - file specified with @code{log-file} parameter.
19995 @code{console} - standard output.
19999 Defaults to @samp{""}.
20003 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
20004 Log file name for @code{log-type} @code{file} parameter.
20006 Defaults to @samp{"/var/log/zabbix/server.log"}.
20010 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
20013 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
20017 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
20018 The location of certificate authority (CA) files for SSL server
20019 certificate verification.
20021 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
20025 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
20026 Location of SSL client certificates.
20028 Defaults to @samp{"/etc/ssl/certs"}.
20032 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
20033 Extra options will be appended to Zabbix server configuration file.
20035 Defaults to @samp{""}.
20039 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
20040 You may include individual files or all files in a directory in the
20041 configuration file.
20043 Defaults to @samp{()}.
20047 @c %end of fragment
20049 @subsubheading Zabbix agent
20050 @cindex zabbix zabbix-agent
20052 Zabbix agent gathers information for Zabbix server.
20054 @c %start of fragment
20056 Available @code{zabbix-agent-configuration} fields are:
20058 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
20059 The zabbix-agent package.
20063 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
20064 User who will run the Zabbix agent.
20066 Defaults to @samp{"zabbix"}.
20070 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
20071 Group who will run the Zabbix agent.
20073 Defaults to @samp{"zabbix"}.
20077 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
20078 Unique, case sensitive hostname which is required for active checks and
20079 must match hostname as configured on the server.
20081 Defaults to @samp{"Zabbix server"}.
20085 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
20086 Specifies where log messages are written to:
20090 @code{system} - syslog.
20093 @code{file} - file specified with @code{log-file} parameter.
20096 @code{console} - standard output.
20100 Defaults to @samp{""}.
20104 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
20105 Log file name for @code{log-type} @code{file} parameter.
20107 Defaults to @samp{"/var/log/zabbix/agent.log"}.
20111 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
20114 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
20118 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
20119 List of IP addresses, optionally in CIDR notation, or hostnames of
20120 Zabbix servers and Zabbix proxies. Incoming connections will be
20121 accepted only from the hosts listed here.
20123 Defaults to @samp{("127.0.0.1")}.
20127 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
20128 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
20129 proxies for active checks. If port is not specified, default port is
20130 used. If this parameter is not specified, active checks are disabled.
20132 Defaults to @samp{("127.0.0.1")}.
20136 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
20137 Extra options will be appended to Zabbix server configuration file.
20139 Defaults to @samp{""}.
20143 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
20144 You may include individual files or all files in a directory in the
20145 configuration file.
20147 Defaults to @samp{()}.
20151 @c %end of fragment
20153 @subsubheading Zabbix front-end
20154 @cindex zabbix zabbix-front-end
20156 This service provides a WEB interface to Zabbix server.
20158 @c %start of fragment
20160 Available @code{zabbix-front-end-configuration} fields are:
20162 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
20163 NGINX configuration.
20167 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
20168 Database host name.
20170 Defaults to @samp{"localhost"}.
20174 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
20177 Defaults to @samp{5432}.
20181 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
20184 Defaults to @samp{"zabbix"}.
20188 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
20191 Defaults to @samp{"zabbix"}.
20195 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
20196 Database password. Please, use @code{db-secret-file} instead.
20198 Defaults to @samp{""}.
20202 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
20203 Secret file which will be appended to @file{zabbix.conf.php} file. This
20204 file contains credentials for use by Zabbix front-end. You are expected
20205 to create it manually.
20207 Defaults to @samp{""}.
20211 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
20212 Zabbix server hostname.
20214 Defaults to @samp{"localhost"}.
20218 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
20219 Zabbix server port.
20221 Defaults to @samp{10051}.
20226 @c %end of fragment
20228 @node Kerberos Services
20229 @subsection Kerberos Services
20232 The @code{(gnu services kerberos)} module provides services relating to
20233 the authentication protocol @dfn{Kerberos}.
20235 @subsubheading Krb5 Service
20237 Programs using a Kerberos client library normally
20238 expect a configuration file in @file{/etc/krb5.conf}.
20239 This service generates such a file from a definition provided in the
20240 operating system declaration.
20241 It does not cause any daemon to be started.
20243 No ``keytab'' files are provided by this service---you must explicitly create them.
20244 This service is known to work with the MIT client library, @code{mit-krb5}.
20245 Other implementations have not been tested.
20247 @defvr {Scheme Variable} krb5-service-type
20248 A service type for Kerberos 5 clients.
20252 Here is an example of its use:
20254 (service krb5-service-type
20255 (krb5-configuration
20256 (default-realm "EXAMPLE.COM")
20257 (allow-weak-crypto? #t)
20260 (name "EXAMPLE.COM")
20261 (admin-server "groucho.example.com")
20262 (kdc "karl.example.com"))
20265 (admin-server "kerb-admin.argrx.edu")
20266 (kdc "keys.argrx.edu"))))))
20270 This example provides a Kerberos@tie{}5 client configuration which:
20272 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
20273 of which have distinct administration servers and key distribution centers;
20274 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
20275 specified by clients;
20276 @item Accepts services which only support encryption types known to be weak.
20279 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
20280 Only the most commonly used ones are described here.
20281 For a full list, and more detailed explanation of each, see the MIT
20282 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
20286 @deftp {Data Type} krb5-realm
20287 @cindex realm, kerberos
20290 This field is a string identifying the name of the realm.
20291 A common convention is to use the fully qualified DNS name of your organization,
20292 converted to upper case.
20294 @item @code{admin-server}
20295 This field is a string identifying the host where the administration server is
20299 This field is a string identifying the key distribution center
20304 @deftp {Data Type} krb5-configuration
20307 @item @code{allow-weak-crypto?} (default: @code{#f})
20308 If this flag is @code{#t} then services which only offer encryption algorithms
20309 known to be weak will be accepted.
20311 @item @code{default-realm} (default: @code{#f})
20312 This field should be a string identifying the default Kerberos
20313 realm for the client.
20314 You should set this field to the name of your Kerberos realm.
20315 If this value is @code{#f}
20316 then a realm must be specified with every Kerberos principal when invoking programs
20317 such as @command{kinit}.
20319 @item @code{realms}
20320 This should be a non-empty list of @code{krb5-realm} objects, which clients may
20322 Normally, one of them will have a @code{name} field matching the @code{default-realm}
20328 @subsubheading PAM krb5 Service
20331 The @code{pam-krb5} service allows for login authentication and password
20332 management via Kerberos.
20333 You will need this service if you want PAM enabled applications to authenticate
20334 users using Kerberos.
20336 @defvr {Scheme Variable} pam-krb5-service-type
20337 A service type for the Kerberos 5 PAM module.
20340 @deftp {Data Type} pam-krb5-configuration
20341 Data type representing the configuration of the Kerberos 5 PAM module.
20342 This type has the following parameters:
20344 @item @code{pam-krb5} (default: @code{pam-krb5})
20345 The pam-krb5 package to use.
20347 @item @code{minimum-uid} (default: @code{1000})
20348 The smallest user ID for which Kerberos authentications should be attempted.
20349 Local accounts with lower values will silently fail to authenticate.
20354 @node LDAP Services
20355 @subsection LDAP Services
20357 @cindex nslcd, LDAP service
20359 The @code{(gnu services authentication)} module provides the
20360 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
20361 server. In addition to configuring the service itself, you may want to add
20362 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
20363 Switch} for detailed information.
20365 Here is a simple operating system declaration with a default configuration of
20366 the @code{nslcd-service-type} and a Name Service Switch configuration that
20367 consults the @code{ldap} name service last:
20370 (use-service-modules authentication)
20371 (use-modules (gnu system nss))
20377 (service nslcd-service-type)
20378 (service dhcp-client-service-type)
20380 (name-service-switch
20381 (let ((services (list (name-service (name "db"))
20382 (name-service (name "files"))
20383 (name-service (name "ldap")))))
20384 (name-service-switch
20385 (inherit %mdns-host-lookup-nss)
20386 (password services)
20389 (netgroup services)
20390 (gshadow services)))))
20393 @c %start of generated documentation for nslcd-configuration
20395 Available @code{nslcd-configuration} fields are:
20397 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
20398 The @code{nss-pam-ldapd} package to use.
20402 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
20403 The number of threads to start that can handle requests and perform LDAP
20404 queries. Each thread opens a separate connection to the LDAP server.
20405 The default is to start 5 threads.
20407 Defaults to @samp{disabled}.
20411 @deftypevr {@code{nslcd-configuration} parameter} string uid
20412 This specifies the user id with which the daemon should be run.
20414 Defaults to @samp{"nslcd"}.
20418 @deftypevr {@code{nslcd-configuration} parameter} string gid
20419 This specifies the group id with which the daemon should be run.
20421 Defaults to @samp{"nslcd"}.
20425 @deftypevr {@code{nslcd-configuration} parameter} log-option log
20426 This option controls the way logging is done via a list containing
20427 SCHEME and LEVEL. The SCHEME argument may either be the symbols
20428 @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
20429 argument is optional and specifies the log level. The log level may be
20430 one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
20431 @samp{notice}, @samp{info} or @samp{debug}. All messages with the
20432 specified log level or higher are logged.
20434 Defaults to @samp{("/var/log/nslcd" info)}.
20438 @deftypevr {@code{nslcd-configuration} parameter} list uri
20439 The list of LDAP server URIs. Normally, only the first server will be
20440 used with the following servers as fall-back.
20442 Defaults to @samp{("ldap://localhost:389/")}.
20446 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
20447 The version of the LDAP protocol to use. The default is to use the
20448 maximum version supported by the LDAP library.
20450 Defaults to @samp{disabled}.
20454 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
20455 Specifies the distinguished name with which to bind to the directory
20456 server for lookups. The default is to bind anonymously.
20458 Defaults to @samp{disabled}.
20462 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
20463 Specifies the credentials with which to bind. This option is only
20464 applicable when used with binddn.
20466 Defaults to @samp{disabled}.
20470 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
20471 Specifies the distinguished name to use when the root user tries to
20472 modify a user's password using the PAM module.
20474 Defaults to @samp{disabled}.
20478 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
20479 Specifies the credentials with which to bind if the root user tries to
20480 change a user's password. This option is only applicable when used with
20483 Defaults to @samp{disabled}.
20487 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
20488 Specifies the SASL mechanism to be used when performing SASL
20491 Defaults to @samp{disabled}.
20495 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
20496 Specifies the SASL realm to be used when performing SASL authentication.
20498 Defaults to @samp{disabled}.
20502 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
20503 Specifies the authentication identity to be used when performing SASL
20506 Defaults to @samp{disabled}.
20510 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
20511 Specifies the authorization identity to be used when performing SASL
20514 Defaults to @samp{disabled}.
20518 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
20519 Determines whether the LDAP server host name should be canonicalised. If
20520 this is enabled the LDAP library will do a reverse host name lookup. By
20521 default, it is left up to the LDAP library whether this check is
20524 Defaults to @samp{disabled}.
20528 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
20529 Set the name for the GSS-API Kerberos credentials cache.
20531 Defaults to @samp{disabled}.
20535 @deftypevr {@code{nslcd-configuration} parameter} string base
20536 The directory search base.
20538 Defaults to @samp{"dc=example,dc=com"}.
20542 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
20543 Specifies the search scope (subtree, onelevel, base or children). The
20544 default scope is subtree; base scope is almost never useful for name
20545 service lookups; children scope is not supported on all servers.
20547 Defaults to @samp{(subtree)}.
20551 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
20552 Specifies the policy for dereferencing aliases. The default policy is
20553 to never dereference aliases.
20555 Defaults to @samp{disabled}.
20559 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
20560 Specifies whether automatic referral chasing should be enabled. The
20561 default behaviour is to chase referrals.
20563 Defaults to @samp{disabled}.
20567 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
20568 This option allows for custom attributes to be looked up instead of the
20569 default RFC 2307 attributes. It is a list of maps, each consisting of
20570 the name of a map, the RFC 2307 attribute to match and the query
20571 expression for the attribute as it is available in the directory.
20573 Defaults to @samp{()}.
20577 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
20578 A list of filters consisting of the name of a map to which the filter
20579 applies and an LDAP search filter expression.
20581 Defaults to @samp{()}.
20585 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
20586 Specifies the time limit in seconds to use when connecting to the
20587 directory server. The default value is 10 seconds.
20589 Defaults to @samp{disabled}.
20593 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
20594 Specifies the time limit (in seconds) to wait for a response from the
20595 LDAP server. A value of zero, which is the default, is to wait
20596 indefinitely for searches to be completed.
20598 Defaults to @samp{disabled}.
20602 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
20603 Specifies the period if inactivity (in seconds) after which the con‐
20604 nection to the LDAP server will be closed. The default is not to time
20607 Defaults to @samp{disabled}.
20611 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
20612 Specifies the number of seconds to sleep when connecting to all LDAP
20613 servers fails. By default one second is waited between the first
20614 failure and the first retry.
20616 Defaults to @samp{disabled}.
20620 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
20621 Specifies the time after which the LDAP server is considered to be
20622 permanently unavailable. Once this time is reached retries will be done
20623 only once per this time period. The default value is 10 seconds.
20625 Defaults to @samp{disabled}.
20629 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
20630 Specifies whether to use SSL/TLS or not (the default is not to). If
20631 'start-tls is specified then StartTLS is used rather than raw LDAP over
20634 Defaults to @samp{disabled}.
20638 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
20639 Specifies what checks to perform on a server-supplied certificate. The
20640 meaning of the values is described in the ldap.conf(5) manual page.
20642 Defaults to @samp{disabled}.
20646 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
20647 Specifies the directory containing X.509 certificates for peer authen‐
20648 tication. This parameter is ignored when using GnuTLS.
20650 Defaults to @samp{disabled}.
20654 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
20655 Specifies the path to the X.509 certificate for peer authentication.
20657 Defaults to @samp{disabled}.
20661 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
20662 Specifies the path to an entropy source. This parameter is ignored when
20665 Defaults to @samp{disabled}.
20669 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
20670 Specifies the ciphers to use for TLS as a string.
20672 Defaults to @samp{disabled}.
20676 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
20677 Specifies the path to the file containing the local certificate for
20678 client TLS authentication.
20680 Defaults to @samp{disabled}.
20684 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
20685 Specifies the path to the file containing the private key for client TLS
20688 Defaults to @samp{disabled}.
20692 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
20693 Set this to a number greater than 0 to request paged results from the
20694 LDAP server in accordance with RFC2696. The default (0) is to not
20695 request paged results.
20697 Defaults to @samp{disabled}.
20701 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
20702 This option prevents group membership lookups through LDAP for the
20703 specified users. Alternatively, the value 'all-local may be used. With
20704 that value nslcd builds a full list of non-LDAP users on startup.
20706 Defaults to @samp{disabled}.
20710 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
20711 This option ensures that LDAP users with a numeric user id lower than
20712 the specified value are ignored.
20714 Defaults to @samp{disabled}.
20718 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
20719 This option specifies an offset that is added to all LDAP numeric user
20720 ids. This can be used to avoid user id collisions with local users.
20722 Defaults to @samp{disabled}.
20726 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
20727 This option specifies an offset that is added to all LDAP numeric group
20728 ids. This can be used to avoid user id collisions with local groups.
20730 Defaults to @samp{disabled}.
20734 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
20735 If this option is set, the member attribute of a group may point to
20736 another group. Members of nested groups are also returned in the higher
20737 level group and parent groups are returned when finding groups for a
20738 specific user. The default is not to perform extra searches for nested
20741 Defaults to @samp{disabled}.
20745 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
20746 If this option is set, the group member list is not retrieved when
20747 looking up groups. Lookups for finding which groups a user belongs to
20748 will remain functional so the user will likely still get the correct
20749 groups assigned on login.
20751 Defaults to @samp{disabled}.
20755 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
20756 If this option is set, functions which cause all user/group entries to
20757 be loaded from the directory will not succeed in doing so. This can
20758 dramatically reduce LDAP server load in situations where there are a
20759 great number of users and/or groups. This option is not recommended for
20760 most configurations.
20762 Defaults to @samp{disabled}.
20766 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
20767 This option can be used to specify how user and group names are verified
20768 within the system. This pattern is used to check all user and group
20769 names that are requested and returned from LDAP.
20771 Defaults to @samp{disabled}.
20775 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
20776 This specifies whether or not to perform searches using case-insensitive
20777 matching. Enabling this could open up the system to authorization
20778 bypass vulnerabilities and introduce nscd cache poisoning
20779 vulnerabilities which allow denial of service.
20781 Defaults to @samp{disabled}.
20785 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
20786 This option specifies whether password policy controls are requested and
20787 handled from the LDAP server when performing user authentication.
20789 Defaults to @samp{disabled}.
20793 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
20794 By default nslcd performs an LDAP search with the user's credentials
20795 after BIND (authentication) to ensure that the BIND operation was
20796 successful. The default search is a simple check to see if the user's
20797 DN exists. A search filter can be specified that will be used instead.
20798 It should return at least one entry.
20800 Defaults to @samp{disabled}.
20804 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
20805 This option allows flexible fine tuning of the authorisation check that
20806 should be performed. The search filter specified is executed and if any
20807 entries match, access is granted, otherwise access is denied.
20809 Defaults to @samp{disabled}.
20813 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
20814 If this option is set password modification using pam_ldap will be
20815 denied and the specified message will be presented to the user instead.
20816 The message can be used to direct the user to an alternative means of
20817 changing their password.
20819 Defaults to @samp{disabled}.
20823 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
20824 List of pam service names for which LDAP authentication should suffice.
20826 Defaults to @samp{()}.
20830 @c %end of generated documentation for nslcd-configuration
20834 @subsection Web Services
20839 The @code{(gnu services web)} module provides the Apache HTTP Server,
20840 the nginx web server, and also a fastcgi wrapper daemon.
20842 @subsubheading Apache HTTP Server
20844 @deffn {Scheme Variable} httpd-service-type
20845 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
20846 (@dfn{httpd}). The value for this service type is a
20847 @code{httpd-configuration} record.
20849 A simple example configuration is given below.
20852 (service httpd-service-type
20853 (httpd-configuration
20856 (server-name "www.example.com")
20857 (document-root "/srv/http/www.example.com")))))
20860 Other services can also extend the @code{httpd-service-type} to add to
20864 (simple-service 'www.example.com-server httpd-service-type
20868 (list (string-join '("ServerName www.example.com"
20869 "DocumentRoot /srv/http/www.example.com")
20874 The details for the @code{httpd-configuration}, @code{httpd-module},
20875 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
20878 @deffn {Data Type} httpd-configuration
20879 This data type represents the configuration for the httpd service.
20882 @item @code{package} (default: @code{httpd})
20883 The httpd package to use.
20885 @item @code{pid-file} (default: @code{"/var/run/httpd"})
20886 The pid file used by the shepherd-service.
20888 @item @code{config} (default: @code{(httpd-config-file)})
20889 The configuration file to use with the httpd service. The default value
20890 is a @code{httpd-config-file} record, but this can also be a different
20891 G-expression that generates a file, for example a @code{plain-file}. A
20892 file outside of the store can also be specified through a string.
20897 @deffn {Data Type} httpd-module
20898 This data type represents a module for the httpd service.
20902 The name of the module.
20905 The file for the module. This can be relative to the httpd package being
20906 used, the absolute location of a file, or a G-expression for a file
20907 within the store, for example @code{(file-append mod-wsgi
20908 "/modules/mod_wsgi.so")}.
20913 @defvr {Scheme Variable} %default-httpd-modules
20914 A default list of @code{httpd-module} objects.
20917 @deffn {Data Type} httpd-config-file
20918 This data type represents a configuration file for the httpd service.
20921 @item @code{modules} (default: @code{%default-httpd-modules})
20922 The modules to load. Additional modules can be added here, or loaded by
20923 additional configuration.
20925 For example, in order to handle requests for PHP files, you can use Apache’s
20926 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
20929 (service httpd-service-type
20930 (httpd-configuration
20935 (name "proxy_module")
20936 (file "modules/mod_proxy.so"))
20938 (name "proxy_fcgi_module")
20939 (file "modules/mod_proxy_fcgi.so"))
20940 %default-httpd-modules))
20941 (extra-config (list "\
20942 <FilesMatch \\.php$>
20943 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
20944 </FilesMatch>"))))))
20945 (service php-fpm-service-type
20946 (php-fpm-configuration
20947 (socket "/var/run/php-fpm.sock")
20948 (socket-group "httpd")))
20951 @item @code{server-root} (default: @code{httpd})
20952 The @code{ServerRoot} in the configuration file, defaults to the httpd
20953 package. Directives including @code{Include} and @code{LoadModule} are
20954 taken as relative to the server root.
20956 @item @code{server-name} (default: @code{#f})
20957 The @code{ServerName} in the configuration file, used to specify the
20958 request scheme, hostname and port that the server uses to identify
20961 This doesn't need to be set in the server config, and can be specified
20962 in virtual hosts. The default is @code{#f} to not specify a
20965 @item @code{document-root} (default: @code{"/srv/http"})
20966 The @code{DocumentRoot} from which files will be served.
20968 @item @code{listen} (default: @code{'("80")})
20969 The list of values for the @code{Listen} directives in the config
20970 file. The value should be a list of strings, when each string can
20971 specify the port number to listen on, and optionally the IP address and
20974 @item @code{pid-file} (default: @code{"/var/run/httpd"})
20975 The @code{PidFile} to use. This should match the @code{pid-file} set in
20976 the @code{httpd-configuration} so that the Shepherd service is
20977 configured correctly.
20979 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
20980 The @code{ErrorLog} to which the server will log errors.
20982 @item @code{user} (default: @code{"httpd"})
20983 The @code{User} which the server will answer requests as.
20985 @item @code{group} (default: @code{"httpd"})
20986 The @code{Group} which the server will answer requests as.
20988 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
20989 A flat list of strings and G-expressions which will be added to the end
20990 of the configuration file.
20992 Any values which the service is extended with will be appended to this
20998 @deffn {Data Type} httpd-virtualhost
20999 This data type represents a virtualhost configuration block for the httpd service.
21001 These should be added to the extra-config for the httpd-service.
21004 (simple-service 'www.example.com-server httpd-service-type
21008 (list (string-join '("ServerName www.example.com"
21009 "DocumentRoot /srv/http/www.example.com")
21014 @item @code{addresses-and-ports}
21015 The addresses and ports for the @code{VirtualHost} directive.
21017 @item @code{contents}
21018 The contents of the @code{VirtualHost} directive, this should be a list
21019 of strings and G-expressions.
21024 @subsubheading NGINX
21026 @deffn {Scheme Variable} nginx-service-type
21027 Service type for the @uref{https://nginx.org/,NGinx} web server. The
21028 value for this service type is a @code{<nginx-configuration>} record.
21030 A simple example configuration is given below.
21033 (service nginx-service-type
21034 (nginx-configuration
21036 (list (nginx-server-configuration
21037 (server-name '("www.example.com"))
21038 (root "/srv/http/www.example.com"))))))
21041 In addition to adding server blocks to the service configuration
21042 directly, this service can be extended by other services to add server
21043 blocks, as in this example:
21046 (simple-service 'my-extra-server nginx-service-type
21047 (list (nginx-server-configuration
21048 (root "/srv/http/extra-website")
21049 (try-files (list "$uri" "$uri/index.html")))))
21053 At startup, @command{nginx} has not yet read its configuration file, so
21054 it uses a default file to log error messages. If it fails to load its
21055 configuration file, that is where error messages are logged. After the
21056 configuration file is loaded, the default error log file changes as per
21057 configuration. In our case, startup error messages can be found in
21058 @file{/var/run/nginx/logs/error.log}, and after configuration in
21059 @file{/var/log/nginx/error.log}. The second location can be changed
21060 with the @var{log-directory} configuration option.
21062 @deffn {Data Type} nginx-configuration
21063 This data type represents the configuration for NGinx. Some
21064 configuration can be done through this and the other provided record
21065 types, or alternatively, a config file can be provided.
21068 @item @code{nginx} (default: @code{nginx})
21069 The nginx package to use.
21071 @item @code{log-directory} (default: @code{"/var/log/nginx"})
21072 The directory to which NGinx will write log files.
21074 @item @code{run-directory} (default: @code{"/var/run/nginx"})
21075 The directory in which NGinx will create a pid file, and write temporary
21078 @item @code{server-blocks} (default: @code{'()})
21079 A list of @dfn{server blocks} to create in the generated configuration
21080 file, the elements should be of type
21081 @code{<nginx-server-configuration>}.
21083 The following example would setup NGinx to serve @code{www.example.com}
21084 from the @code{/srv/http/www.example.com} directory, without using
21087 (service nginx-service-type
21088 (nginx-configuration
21090 (list (nginx-server-configuration
21091 (server-name '("www.example.com"))
21092 (root "/srv/http/www.example.com"))))))
21095 @item @code{upstream-blocks} (default: @code{'()})
21096 A list of @dfn{upstream blocks} to create in the generated configuration
21097 file, the elements should be of type
21098 @code{<nginx-upstream-configuration>}.
21100 Configuring upstreams through the @code{upstream-blocks} can be useful
21101 when combined with @code{locations} in the
21102 @code{<nginx-server-configuration>} records. The following example
21103 creates a server configuration with one location configuration, that
21104 will proxy requests to a upstream configuration, which will handle
21105 requests with two servers.
21110 (nginx-configuration
21112 (list (nginx-server-configuration
21113 (server-name '("www.example.com"))
21114 (root "/srv/http/www.example.com")
21117 (nginx-location-configuration
21119 (body '("proxy_pass http://server-proxy;"))))))))
21121 (list (nginx-upstream-configuration
21122 (name "server-proxy")
21123 (servers (list "server1.example.com"
21124 "server2.example.com")))))))
21127 @item @code{file} (default: @code{#f})
21128 If a configuration @var{file} is provided, this will be used, rather than
21129 generating a configuration file from the provided @code{log-directory},
21130 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
21131 proper operation, these arguments should match what is in @var{file} to ensure
21132 that the directories are created when the service is activated.
21134 This can be useful if you have an existing configuration file, or it's
21135 not possible to do what is required through the other parts of the
21136 nginx-configuration record.
21138 @item @code{server-names-hash-bucket-size} (default: @code{#f})
21139 Bucket size for the server names hash tables, defaults to @code{#f} to
21140 use the size of the processors cache line.
21142 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
21143 Maximum bucket size for the server names hash tables.
21145 @item @code{modules} (default: @code{'()})
21146 List of nginx dynamic modules to load. This should be a list of file
21147 names of loadable modules, as in this example:
21152 (file-append nginx-accept-language-module "\
21153 /etc/nginx/modules/ngx_http_accept_language_module.so")))
21156 @item @code{global-directives} (default: @code{'((events . ()))})
21157 Association list of global directives for the top level of the nginx
21158 configuration. Values may themselves be association lists.
21162 `((worker_processes . 16)
21164 (events . ((worker_connections . 1024)))))
21167 @item @code{extra-content} (default: @code{""})
21168 Extra content for the @code{http} block. Should be string or a string
21169 valued G-expression.
21174 @deftp {Data Type} nginx-server-configuration
21175 Data type representing the configuration of an nginx server block.
21176 This type has the following parameters:
21179 @item @code{listen} (default: @code{'("80" "443 ssl")})
21180 Each @code{listen} directive sets the address and port for IP, or the
21181 path for a UNIX-domain socket on which the server will accept requests.
21182 Both address and port, or only address or only port can be specified.
21183 An address may also be a hostname, for example:
21186 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
21189 @item @code{server-name} (default: @code{(list 'default)})
21190 A list of server names this server represents. @code{'default} represents the
21191 default server for connections matching no other server.
21193 @item @code{root} (default: @code{"/srv/http"})
21194 Root of the website nginx will serve.
21196 @item @code{locations} (default: @code{'()})
21197 A list of @dfn{nginx-location-configuration} or
21198 @dfn{nginx-named-location-configuration} records to use within this
21201 @item @code{index} (default: @code{(list "index.html")})
21202 Index files to look for when clients ask for a directory. If it cannot be found,
21203 Nginx will send the list of files in the directory.
21205 @item @code{try-files} (default: @code{'()})
21206 A list of files whose existence is checked in the specified order.
21207 @code{nginx} will use the first file it finds to process the request.
21209 @item @code{ssl-certificate} (default: @code{#f})
21210 Where to find the certificate for secure connections. Set it to @code{#f} if
21211 you don't have a certificate or you don't want to use HTTPS.
21213 @item @code{ssl-certificate-key} (default: @code{#f})
21214 Where to find the private key for secure connections. Set it to @code{#f} if
21215 you don't have a key or you don't want to use HTTPS.
21217 @item @code{server-tokens?} (default: @code{#f})
21218 Whether the server should add its configuration to response.
21220 @item @code{raw-content} (default: @code{'()})
21221 A list of raw lines added to the server block.
21226 @deftp {Data Type} nginx-upstream-configuration
21227 Data type representing the configuration of an nginx @code{upstream}
21228 block. This type has the following parameters:
21232 Name for this group of servers.
21234 @item @code{servers}
21235 Specify the addresses of the servers in the group. The address can be
21236 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
21237 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
21238 prefix @samp{unix:}. For addresses using an IP address or domain name,
21239 the default port is 80, and a different port can be specified
21245 @deftp {Data Type} nginx-location-configuration
21246 Data type representing the configuration of an nginx @code{location}
21247 block. This type has the following parameters:
21251 URI which this location block matches.
21253 @anchor{nginx-location-configuration body}
21255 Body of the location block, specified as a list of strings. This can contain
21257 configuration directives. For example, to pass requests to a upstream
21258 server group defined using an @code{nginx-upstream-configuration} block,
21259 the following directive would be specified in the body @samp{(list "proxy_pass
21260 http://upstream-name;")}.
21265 @deftp {Data Type} nginx-named-location-configuration
21266 Data type representing the configuration of an nginx named location
21267 block. Named location blocks are used for request redirection, and not
21268 used for regular request processing. This type has the following
21273 Name to identify this location block.
21276 @xref{nginx-location-configuration body}, as the body for named location
21277 blocks can be used in a similar way to the
21278 @code{nginx-location-configuration body}. One restriction is that the
21279 body of a named location block cannot contain location blocks.
21284 @subsubheading Varnish Cache
21286 Varnish is a fast cache server that sits in between web applications
21287 and end users. It proxies requests from clients and caches the
21288 accessed URLs such that multiple requests for the same resource only
21289 creates one request to the back-end.
21291 @defvr {Scheme Variable} varnish-service-type
21292 Service type for the Varnish daemon.
21295 @deftp {Data Type} varnish-configuration
21296 Data type representing the @code{varnish} service configuration.
21297 This type has the following parameters:
21300 @item @code{package} (default: @code{varnish})
21301 The Varnish package to use.
21303 @item @code{name} (default: @code{"default"})
21304 A name for this Varnish instance. Varnish will create a directory in
21305 @file{/var/varnish/} with this name and keep temporary files there. If
21306 the name starts with a forward slash, it is interpreted as an absolute
21309 Pass the @code{-n} argument to other Varnish programs to connect to the
21310 named instance, e.g.@: @command{varnishncsa -n default}.
21312 @item @code{backend} (default: @code{"localhost:8080"})
21313 The backend to use. This option has no effect if @code{vcl} is set.
21315 @item @code{vcl} (default: #f)
21316 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
21317 is @code{#f}, Varnish will proxy @code{backend} using the default
21318 configuration. Otherwise this must be a file-like object with valid
21321 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
21322 For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
21323 can do something along these lines:
21326 (define %gnu-mirror
21327 (plain-file "gnu.vcl"
21329 backend gnu @{ .host = \"www.gnu.org\"; @}"))
21333 (services (cons (service varnish-service-type
21334 (varnish-configuration
21336 (vcl %gnu-mirror)))
21340 The configuration of an already running Varnish instance can be inspected
21341 and changed using the @command{varnishadm} program.
21343 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
21344 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
21345 comprehensive documentation on Varnish and its configuration language.
21347 @item @code{listen} (default: @code{'("localhost:80")})
21348 List of addresses Varnish will listen on.
21350 @item @code{storage} (default: @code{'("malloc,128m")})
21351 List of storage backends that will be available in VCL.
21353 @item @code{parameters} (default: @code{'()})
21354 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
21356 @item @code{extra-options} (default: @code{'()})
21357 Additional arguments to pass to the @command{varnishd} process.
21362 @subsubheading Patchwork
21364 Patchwork is a patch tracking system. It can collect patches sent to a
21365 mailing list, and display them in a web interface.
21367 @defvr {Scheme Variable} patchwork-service-type
21368 Service type for Patchwork.
21371 The following example is an example of a minimal service for Patchwork, for
21372 the @code{patchwork.example.com} domain.
21375 (service patchwork-service-type
21376 (patchwork-configuration
21377 (domain "patchwork.example.com")
21379 (patchwork-settings-module
21380 (allowed-hosts (list domain))
21381 (default-from-email "patchwork@@patchwork.example.com")))
21382 (getmail-retriever-config
21383 (getmail-retriever-configuration
21384 (type "SimpleIMAPSSLRetriever")
21385 (server "imap.example.com")
21387 (username "patchwork")
21389 (list (file-append coreutils "/bin/cat")
21390 "/etc/getmail-patchwork-imap-password"))
21392 '((mailboxes . ("Patches"))))))))
21396 There are three records for configuring the Patchwork service. The
21397 @code{<patchwork-configuration>} relates to the configuration for Patchwork
21398 within the HTTPD service.
21400 The @code{settings-module} field within the @code{<patchwork-configuration>}
21401 record can be populated with the @code{<patchwork-settings-module>} record,
21402 which describes a settings module that is generated within the Guix store.
21404 For the @code{database-configuration} field within the
21405 @code{<patchwork-settings-module>}, the
21406 @code{<patchwork-database-configuration>} must be used.
21408 @deftp {Data Type} patchwork-configuration
21409 Data type representing the Patchwork service configuration. This type has the
21410 following parameters:
21413 @item @code{patchwork} (default: @code{patchwork})
21414 The Patchwork package to use.
21416 @item @code{domain}
21417 The domain to use for Patchwork, this is used in the HTTPD service virtual
21420 @item @code{settings-module}
21421 The settings module to use for Patchwork. As a Django application, Patchwork
21422 is configured with a Python module containing the settings. This can either be
21423 an instance of the @code{<patchwork-settings-module>} record, any other record
21424 that represents the settings in the store, or a directory outside of the
21427 @item @code{static-path} (default: @code{"/static/"})
21428 The path under which the HTTPD service should serve the static files.
21430 @item @code{getmail-retriever-config}
21431 The getmail-retriever-configuration record value to use with
21432 Patchwork. Getmail will be configured with this value, the messages will be
21433 delivered to Patchwork.
21438 @deftp {Data Type} patchwork-settings-module
21439 Data type representing a settings module for Patchwork. Some of these
21440 settings relate directly to Patchwork, but others relate to Django, the web
21441 framework used by Patchwork, or the Django Rest Framework library. This type
21442 has the following parameters:
21445 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
21446 The database connection settings used for Patchwork. See the
21447 @code{<patchwork-database-configuration>} record type for more information.
21449 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
21450 Patchwork, as a Django web application uses a secret key for cryptographically
21451 signing values. This file should contain a unique unpredictable value.
21453 If this file does not exist, it will be created and populated with a random
21454 value by the patchwork-setup shepherd service.
21456 This setting relates to Django.
21458 @item @code{allowed-hosts}
21459 A list of valid hosts for this Patchwork service. This should at least include
21460 the domain specified in the @code{<patchwork-configuration>} record.
21462 This is a Django setting.
21464 @item @code{default-from-email}
21465 The email address from which Patchwork should send email by default.
21467 This is a Patchwork setting.
21469 @item @code{static-url} (default: @code{#f})
21470 The URL to use when serving static assets. It can be part of a URL, or a full
21471 URL, but must end in a @code{/}.
21473 If the default value is used, the @code{static-path} value from the
21474 @code{<patchwork-configuration>} record will be used.
21476 This is a Django setting.
21478 @item @code{admins} (default: @code{'()})
21479 Email addresses to send the details of errors that occur. Each value should
21480 be a list containing two elements, the name and then the email address.
21482 This is a Django setting.
21484 @item @code{debug?} (default: @code{#f})
21485 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
21486 messages will be shown.
21488 This is a Django setting.
21490 @item @code{enable-rest-api?} (default: @code{#t})
21491 Whether to enable the Patchwork REST API.
21493 This is a Patchwork setting.
21495 @item @code{enable-xmlrpc?} (default: @code{#t})
21496 Whether to enable the XML RPC API.
21498 This is a Patchwork setting.
21500 @item @code{force-https-links?} (default: @code{#t})
21501 Whether to use HTTPS links on Patchwork pages.
21503 This is a Patchwork setting.
21505 @item @code{extra-settings} (default: @code{""})
21506 Extra code to place at the end of the Patchwork settings module.
21511 @deftp {Data Type} patchwork-database-configuration
21512 Data type representing the database configuration for Patchwork.
21515 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
21516 The database engine to use.
21518 @item @code{name} (default: @code{"patchwork"})
21519 The name of the database to use.
21521 @item @code{user} (default: @code{"httpd"})
21522 The user to connect to the database as.
21524 @item @code{password} (default: @code{""})
21525 The password to use when connecting to the database.
21527 @item @code{host} (default: @code{""})
21528 The host to make the database connection to.
21530 @item @code{port} (default: @code{""})
21531 The port on which to connect to the database.
21536 @subsubheading Mumi
21538 @cindex Mumi, Debbugs Web interface
21539 @cindex Debbugs, Mumi Web interface
21540 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
21541 Web interface to the Debbugs bug tracker, by default for
21542 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
21543 but it also fetches and indexes mail retrieved from Debbugs.
21545 @defvr {Scheme Variable} mumi-service-type
21546 This is the service type for Mumi.
21549 @deftp {Data Type} mumi-configuration
21550 Data type representing the Mumi service configuration. This type has the
21554 @item @code{mumi} (default: @code{mumi})
21555 The Mumi package to use.
21557 @item @code{mailer?} (default: @code{#true})
21558 Whether to enable or disable the mailer component.
21560 @item @code{mumi-configuration-sender}
21561 The email address used as the sender for comments.
21563 @item @code{mumi-configuration-smtp}
21564 A URI to configure the SMTP settings for Mailutils. This could be
21565 something like @code{sendmail:///path/to/bin/msmtp} or any other URI
21566 supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
21567 mailutils, GNU@tie{}Mailutils}.
21573 @subsubheading FastCGI
21576 FastCGI is an interface between the front-end and the back-end of a web
21577 service. It is a somewhat legacy facility; new web services should
21578 generally just talk HTTP between the front-end and the back-end.
21579 However there are a number of back-end services such as PHP or the
21580 optimized HTTP Git repository access that use FastCGI, so we have
21581 support for it in Guix.
21583 To use FastCGI, you configure the front-end web server (e.g., nginx) to
21584 dispatch some subset of its requests to the fastcgi backend, which
21585 listens on a local TCP or UNIX socket. There is an intermediary
21586 @code{fcgiwrap} program that sits between the actual backend process and
21587 the web server. The front-end indicates which backend program to run,
21588 passing that information to the @code{fcgiwrap} process.
21590 @defvr {Scheme Variable} fcgiwrap-service-type
21591 A service type for the @code{fcgiwrap} FastCGI proxy.
21594 @deftp {Data Type} fcgiwrap-configuration
21595 Data type representing the configuration of the @code{fcgiwrap} service.
21596 This type has the following parameters:
21598 @item @code{package} (default: @code{fcgiwrap})
21599 The fcgiwrap package to use.
21601 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
21602 The socket on which the @code{fcgiwrap} process should listen, as a
21603 string. Valid @var{socket} values include
21604 @code{unix:@var{/path/to/unix/socket}},
21605 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
21606 @code{tcp6:[@var{ipv6_addr}]:port}.
21608 @item @code{user} (default: @code{fcgiwrap})
21609 @itemx @code{group} (default: @code{fcgiwrap})
21610 The user and group names, as strings, under which to run the
21611 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
21612 the user asks for the specific user or group names @code{fcgiwrap} that
21613 the corresponding user and/or group is present on the system.
21615 It is possible to configure a FastCGI-backed web service to pass HTTP
21616 authentication information from the front-end to the back-end, and to
21617 allow @code{fcgiwrap} to run the back-end process as a corresponding
21618 local user. To enable this capability on the back-end, run
21619 @code{fcgiwrap} as the @code{root} user and group. Note that this
21620 capability also has to be configured on the front-end as well.
21625 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
21626 with some additional features useful for sites of any size.
21628 These features include:
21630 @item Adaptive process spawning
21631 @item Basic statistics (similar to Apache's mod_status)
21632 @item Advanced process management with graceful stop/start
21633 @item Ability to start workers with different uid/gid/chroot/environment
21634 and different php.ini (replaces safe_mode)
21635 @item Stdout & stderr logging
21636 @item Emergency restart in case of accidental opcode cache destruction
21637 @item Accelerated upload support
21638 @item Support for a "slowlog"
21639 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
21640 a special function to finish request & flush all data while continuing to do
21641 something time-consuming (video converting, stats processing, etc.)
21643 ...@: and much more.
21645 @defvr {Scheme Variable} php-fpm-service-type
21646 A Service type for @code{php-fpm}.
21649 @deftp {Data Type} php-fpm-configuration
21650 Data Type for php-fpm service configuration.
21652 @item @code{php} (default: @code{php})
21653 The php package to use.
21654 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
21655 The address on which to accept FastCGI requests. Valid syntaxes are:
21657 @item @code{"ip.add.re.ss:port"}
21658 Listen on a TCP socket to a specific address on a specific port.
21659 @item @code{"port"}
21660 Listen on a TCP socket to all addresses on a specific port.
21661 @item @code{"/path/to/unix/socket"}
21662 Listen on a unix socket.
21665 @item @code{user} (default: @code{php-fpm})
21666 User who will own the php worker processes.
21667 @item @code{group} (default: @code{php-fpm})
21668 Group of the worker processes.
21669 @item @code{socket-user} (default: @code{php-fpm})
21670 User who can speak to the php-fpm socket.
21671 @item @code{socket-group} (default: @code{nginx})
21672 Group that can speak to the php-fpm socket.
21673 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
21674 The process id of the php-fpm process is written to this file
21675 once the service has started.
21676 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
21677 Log for the php-fpm master process.
21678 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
21679 Detailed settings for the php-fpm process manager.
21682 @item @code{<php-fpm-dynamic-process-manager-configuration>}
21683 @item @code{<php-fpm-static-process-manager-configuration>}
21684 @item @code{<php-fpm-on-demand-process-manager-configuration>}
21686 @item @code{display-errors} (default @code{#f})
21687 Determines whether php errors and warning should be sent to clients
21688 and displayed in their browsers.
21689 This is useful for local php development, but a security risk for public sites,
21690 as error messages can reveal passwords and personal data.
21691 @item @code{timezone} (default @code{#f})
21692 Specifies @code{php_admin_value[date.timezone]} parameter.
21693 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
21694 This file will log the @code{stderr} outputs of php worker processes.
21695 Can be set to @code{#f} to disable logging.
21696 @item @code{file} (default @code{#f})
21697 An optional override of the whole configuration.
21698 You can use the @code{mixed-text-file} function or an absolute filepath for it.
21702 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
21703 Data Type for the @code{dynamic} php-fpm process manager. With the
21704 @code{dynamic} process manager, spare worker processes are kept around
21705 based on it's configured limits.
21707 @item @code{max-children} (default: @code{5})
21708 Maximum of worker processes.
21709 @item @code{start-servers} (default: @code{2})
21710 How many worker processes should be started on start-up.
21711 @item @code{min-spare-servers} (default: @code{1})
21712 How many spare worker processes should be kept around at minimum.
21713 @item @code{max-spare-servers} (default: @code{3})
21714 How many spare worker processes should be kept around at maximum.
21718 @deftp {Data type} php-fpm-static-process-manager-configuration
21719 Data Type for the @code{static} php-fpm process manager. With the
21720 @code{static} process manager, an unchanging number of worker processes
21723 @item @code{max-children} (default: @code{5})
21724 Maximum of worker processes.
21728 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
21729 Data Type for the @code{on-demand} php-fpm process manager. With the
21730 @code{on-demand} process manager, worker processes are only created as
21733 @item @code{max-children} (default: @code{5})
21734 Maximum of worker processes.
21735 @item @code{process-idle-timeout} (default: @code{10})
21736 The time in seconds after which a process with no requests is killed.
21741 @deffn {Scheme Procedure} nginx-php-location @
21742 [#:nginx-package nginx] @
21743 [socket (string-append "/var/run/php" @
21744 (version-major (package-version php)) @
21746 A helper function to quickly add php to an @code{nginx-server-configuration}.
21749 A simple services setup for nginx with php can look like this:
21751 (services (cons* (service dhcp-client-service-type)
21752 (service php-fpm-service-type)
21753 (service nginx-service-type
21754 (nginx-server-configuration
21755 (server-name '("example.com"))
21756 (root "/srv/http/")
21758 (list (nginx-php-location)))
21760 (ssl-certificate #f)
21761 (ssl-certificate-key #f)))
21765 @cindex cat-avatar-generator
21766 The cat avatar generator is a simple service to demonstrate the use of php-fpm
21767 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
21768 the hash of a user's email address.
21770 @deffn {Scheme Procedure} cat-avatar-generator-service @
21771 [#:cache-dir "/var/cache/cat-avatar-generator"] @
21772 [#:package cat-avatar-generator] @
21773 [#:configuration (nginx-server-configuration)]
21774 Returns an nginx-server-configuration that inherits @code{configuration}. It
21775 extends the nginx configuration to add a server block that serves @code{package},
21776 a version of cat-avatar-generator. During execution, cat-avatar-generator will
21777 be able to use @code{cache-dir} as its cache directory.
21780 A simple setup for cat-avatar-generator can look like this:
21782 (services (cons* (cat-avatar-generator-service
21784 (nginx-server-configuration
21785 (server-name '("example.com"))))
21790 @subsubheading Hpcguix-web
21792 @cindex hpcguix-web
21793 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
21794 program is a customizable web interface to browse Guix packages,
21795 initially designed for users of high-performance computing (HPC)
21798 @defvr {Scheme Variable} hpcguix-web-service-type
21799 The service type for @code{hpcguix-web}.
21802 @deftp {Data Type} hpcguix-web-configuration
21803 Data type for the hpcguix-web service configuration.
21807 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
21808 configuration. The main items available in this spec are:
21811 @item @code{title-prefix} (default: @code{"hpcguix | "})
21812 The page title prefix.
21814 @item @code{guix-command} (default: @code{"guix"})
21815 The @command{guix} command.
21817 @item @code{package-filter-proc} (default: @code{(const #t)})
21818 A procedure specifying how to filter packages that are displayed.
21820 @item @code{package-page-extension-proc} (default: @code{(const '())})
21821 Extension package for @code{hpcguix-web}.
21823 @item @code{menu} (default: @code{'()})
21824 Additional entry in page @code{menu}.
21826 @item @code{channels} (default: @code{%default-channels})
21827 List of channels from which the package list is built (@pxref{Channels}).
21829 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
21830 The expiration time, in seconds, after which the package list is rebuilt from
21831 the latest instances of the given channels.
21834 See the hpcguix-web repository for a
21835 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
21838 @item @code{package} (default: @code{hpcguix-web})
21839 The hpcguix-web package to use.
21843 A typical hpcguix-web service declaration looks like this:
21846 (service hpcguix-web-service-type
21847 (hpcguix-web-configuration
21849 #~(define site-config
21850 (hpcweb-configuration
21851 (title-prefix "Guix-HPC - ")
21852 (menu '(("/about" "ABOUT"))))))))
21856 The hpcguix-web service periodically updates the package list it publishes by
21857 pulling channels from Git. To that end, it needs to access X.509 certificates
21858 so that it can authenticate Git servers when communicating over HTTPS, and it
21859 assumes that @file{/etc/ssl/certs} contains those certificates.
21861 Thus, make sure to add @code{nss-certs} or another certificate package to the
21862 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
21863 more information on X.509 certificates.
21866 @node Certificate Services
21867 @subsection Certificate Services
21870 @cindex HTTP, HTTPS
21871 @cindex Let's Encrypt
21872 @cindex TLS certificates
21873 The @code{(gnu services certbot)} module provides a service to
21874 automatically obtain a valid TLS certificate from the Let's Encrypt
21875 certificate authority. These certificates can then be used to serve
21876 content securely over HTTPS or other TLS-based protocols, with the
21877 knowledge that the client will be able to verify the server's
21880 @url{https://letsencrypt.org/, Let's Encrypt} provides the
21881 @code{certbot} tool to automate the certification process. This tool
21882 first securely generates a key on the server. It then makes a request
21883 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
21884 checks that the request originates from the host in question by using a
21885 challenge-response protocol, requiring the server to provide its
21886 response over HTTP. If that protocol completes successfully, the CA
21887 signs the key, resulting in a certificate. That certificate is valid
21888 for a limited period of time, and therefore to continue to provide TLS
21889 services, the server needs to periodically ask the CA to renew its
21892 The certbot service automates this process: the initial key
21893 generation, the initial certification request to the Let's Encrypt
21894 service, the web server challenge/response integration, writing the
21895 certificate to disk, the automated periodic renewals, and the deployment
21896 tasks associated with the renewal (e.g.@: reloading services, copying keys
21897 with different permissions).
21899 Certbot is run twice a day, at a random minute within the hour. It
21900 won't do anything until your certificates are due for renewal or
21901 revoked, but running it regularly would give your service a chance of
21902 staying online in case a Let's Encrypt-initiated revocation happened for
21905 By using this service, you agree to the ACME Subscriber Agreement, which
21906 can be found there:
21907 @url{https://acme-v01.api.letsencrypt.org/directory}.
21909 @defvr {Scheme Variable} certbot-service-type
21910 A service type for the @code{certbot} Let's Encrypt client. Its value
21911 must be a @code{certbot-configuration} record as in this example:
21914 (define %nginx-deploy-hook
21916 "nginx-deploy-hook"
21917 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
21918 (kill pid SIGHUP))))
21920 (service certbot-service-type
21921 (certbot-configuration
21922 (email "foo@@example.net")
21925 (certificate-configuration
21926 (domains '("example.net" "www.example.net"))
21927 (deploy-hook %nginx-deploy-hook))
21928 (certificate-configuration
21929 (domains '("bar.example.net")))))))
21932 See below for details about @code{certbot-configuration}.
21935 @deftp {Data Type} certbot-configuration
21936 Data type representing the configuration of the @code{certbot} service.
21937 This type has the following parameters:
21940 @item @code{package} (default: @code{certbot})
21941 The certbot package to use.
21943 @item @code{webroot} (default: @code{/var/www})
21944 The directory from which to serve the Let's Encrypt challenge/response
21947 @item @code{certificates} (default: @code{()})
21948 A list of @code{certificates-configuration}s for which to generate
21949 certificates and request signatures. Each certificate has a @code{name}
21950 and several @code{domains}.
21953 Mandatory email used for registration, recovery contact, and important
21954 account notifications.
21956 @item @code{server} (default: @code{#f})
21957 Optional URL of ACME server. Setting this overrides certbot's default,
21958 which is the Let's Encrypt server.
21960 @item @code{rsa-key-size} (default: @code{2048})
21961 Size of the RSA key.
21963 @item @code{default-location} (default: @i{see below})
21964 The default @code{nginx-location-configuration}. Because @code{certbot}
21965 needs to be able to serve challenges and responses, it needs to be able
21966 to run a web server. It does so by extending the @code{nginx} web
21967 service with an @code{nginx-server-configuration} listening on the
21968 @var{domains} on port 80, and which has a
21969 @code{nginx-location-configuration} for the @code{/.well-known/} URI
21970 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
21971 these nginx configuration data types.
21973 Requests to other URL paths will be matched by the
21974 @code{default-location}, which if present is added to all
21975 @code{nginx-server-configuration}s.
21977 By default, the @code{default-location} will issue a redirect from
21978 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
21979 you to define what to serve on your site via @code{https}.
21981 Pass @code{#f} to not issue a default location.
21985 @deftp {Data Type} certificate-configuration
21986 Data type representing the configuration of a certificate.
21987 This type has the following parameters:
21990 @item @code{name} (default: @i{see below})
21991 This name is used by Certbot for housekeeping and in file paths; it
21992 doesn't affect the content of the certificate itself. To see
21993 certificate names, run @code{certbot certificates}.
21995 Its default is the first provided domain.
21997 @item @code{domains} (default: @code{()})
21998 The first domain provided will be the subject CN of the certificate, and
21999 all domains will be Subject Alternative Names on the certificate.
22001 @item @code{challenge} (default: @code{#f})
22002 The challenge type that has to be run by certbot. If @code{#f} is specified,
22003 default to the HTTP challenge. If a value is specified, defaults to the
22004 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
22005 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
22006 and gives Let's Encrypt permission to log the public IP address of the
22007 requesting machine.
22009 @item @code{authentication-hook} (default: @code{#f})
22010 Command to be run in a shell once for each certificate challenge to be
22011 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
22012 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
22013 contains the validation string and @code{$CERTBOT_TOKEN} contains the
22014 file name of the resource requested when performing an HTTP-01 challenge.
22016 @item @code{cleanup-hook} (default: @code{#f})
22017 Command to be run in a shell once for each certificate challenge that
22018 have been answered by the @code{auth-hook}. For this command, the shell
22019 variables available in the @code{auth-hook} script are still available, and
22020 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
22021 of the @code{auth-hook} script.
22023 @item @code{deploy-hook} (default: @code{#f})
22024 Command to be run in a shell once for each successfully issued
22025 certificate. For this command, the shell variable
22026 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
22027 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
22028 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
22029 contain a space-delimited list of renewed certificate domains (for
22030 example, @samp{"example.com www.example.com"}.
22035 For each @code{certificate-configuration}, the certificate is saved to
22036 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
22037 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
22039 @subsection DNS Services
22040 @cindex DNS (domain name system)
22041 @cindex domain name system (DNS)
22043 The @code{(gnu services dns)} module provides services related to the
22044 @dfn{domain name system} (DNS). It provides a server service for hosting
22045 an @emph{authoritative} DNS server for multiple zones, slave or master.
22046 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
22047 caching and forwarding DNS server for the LAN, which uses
22048 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
22050 @subsubheading Knot Service
22052 An example configuration of an authoritative server for two zones, one master
22056 (define-zone-entries example.org.zone
22057 ;; Name TTL Class Type Data
22058 ("@@" "" "IN" "A" "127.0.0.1")
22059 ("@@" "" "IN" "NS" "ns")
22060 ("ns" "" "IN" "A" "127.0.0.1"))
22062 (define master-zone
22063 (knot-zone-configuration
22064 (domain "example.org")
22066 (origin "example.org")
22067 (entries example.org.zone)))))
22070 (knot-zone-configuration
22071 (domain "plop.org")
22072 (dnssec-policy "default")
22073 (master (list "plop-master"))))
22075 (define plop-master
22076 (knot-remote-configuration
22078 (address (list "208.76.58.171"))))
22082 (services (cons* (service knot-service-type
22083 (knot-configuration
22084 (remotes (list plop-master))
22085 (zones (list master-zone slave-zone))))
22090 @deffn {Scheme Variable} knot-service-type
22091 This is the type for the Knot DNS server.
22093 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
22094 zones, that is to say domain names you would buy from a registrar. This server
22095 is not a resolver, meaning that it can only resolve names for which it is
22096 authoritative. This server can be configured to serve zones as a master server
22097 or a slave server as a per-zone basis. Slave zones will get their data from
22098 masters, and will serve it as an authoritative server. From the point of view
22099 of a resolver, there is no difference between master and slave.
22101 The following data types are used to configure the Knot DNS server:
22104 @deftp {Data Type} knot-key-configuration
22105 Data type representing a key.
22106 This type has the following parameters:
22109 @item @code{id} (default: @code{""})
22110 An identifier for other configuration fields to refer to this key. IDs must
22111 be unique and must not be empty.
22113 @item @code{algorithm} (default: @code{#f})
22114 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
22115 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
22116 and @code{'hmac-sha512}.
22118 @item @code{secret} (default: @code{""})
22119 The secret key itself.
22124 @deftp {Data Type} knot-acl-configuration
22125 Data type representing an Access Control List (ACL) configuration.
22126 This type has the following parameters:
22129 @item @code{id} (default: @code{""})
22130 An identifier for ether configuration fields to refer to this key. IDs must be
22131 unique and must not be empty.
22133 @item @code{address} (default: @code{'()})
22134 An ordered list of IP addresses, network subnets, or network ranges represented
22135 with strings. The query must match one of them. Empty value means that
22136 address match is not required.
22138 @item @code{key} (default: @code{'()})
22139 An ordered list of references to keys represented with strings. The string
22140 must match a key ID defined in a @code{knot-key-configuration}. No key means
22141 that a key is not require to match that ACL.
22143 @item @code{action} (default: @code{'()})
22144 An ordered list of actions that are permitted or forbidden by this ACL. Possible
22145 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
22146 and @code{'update}.
22148 @item @code{deny?} (default: @code{#f})
22149 When true, the ACL defines restrictions. Listed actions are forbidden. When
22150 false, listed actions are allowed.
22155 @deftp {Data Type} zone-entry
22156 Data type representing a record entry in a zone file.
22157 This type has the following parameters:
22160 @item @code{name} (default: @code{"@@"})
22161 The name of the record. @code{"@@"} refers to the origin of the zone. Names
22162 are relative to the origin of the zone. For example, in the @code{example.org}
22163 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
22164 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
22165 refers to @code{ns.example.org}.
22167 @item @code{ttl} (default: @code{""})
22168 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
22170 @item @code{class} (default: @code{"IN"})
22171 The class of the record. Knot currently supports only @code{"IN"} and
22172 partially @code{"CH"}.
22174 @item @code{type} (default: @code{"A"})
22175 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
22176 address), NS (Name Server) and MX (Mail eXchange). Many other types are
22179 @item @code{data} (default: @code{""})
22180 The data contained in the record. For instance an IP address associated with
22181 an A record, or a domain name associated with an NS record. Remember that
22182 domain names are relative to the origin unless they end with a dot.
22187 @deftp {Data Type} zone-file
22188 Data type representing the content of a zone file.
22189 This type has the following parameters:
22192 @item @code{entries} (default: @code{'()})
22193 The list of entries. The SOA record is taken care of, so you don't need to
22194 put it in the list of entries. This list should probably contain an entry
22195 for your primary authoritative DNS server. Other than using a list of entries
22196 directly, you can use @code{define-zone-entries} to define a object containing
22197 the list of entries more easily, that you can later pass to the @code{entries}
22198 field of the @code{zone-file}.
22200 @item @code{origin} (default: @code{""})
22201 The name of your zone. This parameter cannot be empty.
22203 @item @code{ns} (default: @code{"ns"})
22204 The domain of your primary authoritative DNS server. The name is relative to
22205 the origin, unless it ends with a dot. It is mandatory that this primary
22206 DNS server corresponds to an NS record in the zone and that it is associated
22207 to an IP address in the list of entries.
22209 @item @code{mail} (default: @code{"hostmaster"})
22210 An email address people can contact you at, as the owner of the zone. This
22211 is translated as @code{<mail>@@<origin>}.
22213 @item @code{serial} (default: @code{1})
22214 The serial number of the zone. As this is used to keep track of changes by
22215 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
22216 Always increment it when you make a change in your zone.
22218 @item @code{refresh} (default: @code{(* 2 24 3600)})
22219 The frequency at which slaves will do a zone transfer. This value is a number
22220 of seconds. It can be computed by multiplications or with
22221 @code{(string->duration)}.
22223 @item @code{retry} (default: @code{(* 15 60)})
22224 The period after which a slave will retry to contact its master when it fails
22225 to do so a first time.
22227 @item @code{expiry} (default: @code{(* 14 24 3600)})
22228 Default TTL of records. Existing records are considered correct for at most
22229 this amount of time. After this period, resolvers will invalidate their cache
22230 and check again that it still exists.
22232 @item @code{nx} (default: @code{3600})
22233 Default TTL of inexistant records. This delay is usually short because you want
22234 your new domains to reach everyone quickly.
22239 @deftp {Data Type} knot-remote-configuration
22240 Data type representing a remote configuration.
22241 This type has the following parameters:
22244 @item @code{id} (default: @code{""})
22245 An identifier for other configuration fields to refer to this remote. IDs must
22246 be unique and must not be empty.
22248 @item @code{address} (default: @code{'()})
22249 An ordered list of destination IP addresses. Addresses are tried in sequence.
22250 An optional port can be given with the @@ separator. For instance:
22251 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
22253 @item @code{via} (default: @code{'()})
22254 An ordered list of source IP addresses. An empty list will have Knot choose
22255 an appropriate source IP. An optional port can be given with the @@ separator.
22256 The default is to choose at random.
22258 @item @code{key} (default: @code{#f})
22259 A reference to a key, that is a string containing the identifier of a key
22260 defined in a @code{knot-key-configuration} field.
22265 @deftp {Data Type} knot-keystore-configuration
22266 Data type representing a keystore to hold dnssec keys.
22267 This type has the following parameters:
22270 @item @code{id} (default: @code{""})
22271 The id of the keystore. It must not be empty.
22273 @item @code{backend} (default: @code{'pem})
22274 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
22276 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
22277 The configuration string of the backend. An example for the PKCS#11 is:
22278 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
22279 For the pem backend, the string represents a path in the file system.
22284 @deftp {Data Type} knot-policy-configuration
22285 Data type representing a dnssec policy. Knot DNS is able to automatically
22286 sign your zones. It can either generate and manage your keys automatically or
22287 use keys that you generate.
22289 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
22290 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
22291 zone. In order to be trusted, the KSK needs to be present in the parent zone
22292 (usually a top-level domain). If your registrar supports dnssec, you will
22293 have to send them your KSK's hash so they can add a DS record in their zone.
22294 This is not automated and need to be done each time you change your KSK.
22296 The policy also defines the lifetime of keys. Usually, ZSK can be changed
22297 easily and use weaker cryptographic functions (they use lower parameters) in
22298 order to sign records quickly, so they are changed often. The KSK however
22299 requires manual interaction with the registrar, so they are changed less often
22300 and use stronger parameters because they sign only one record.
22302 This type has the following parameters:
22305 @item @code{id} (default: @code{""})
22306 The id of the policy. It must not be empty.
22308 @item @code{keystore} (default: @code{"default"})
22309 A reference to a keystore, that is a string containing the identifier of a
22310 keystore defined in a @code{knot-keystore-configuration} field. The
22311 @code{"default"} identifier means the default keystore (a kasp database that
22312 was setup by this service).
22314 @item @code{manual?} (default: @code{#f})
22315 Whether the key management is manual or automatic.
22317 @item @code{single-type-signing?} (default: @code{#f})
22318 When @code{#t}, use the Single-Type Signing Scheme.
22320 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
22321 An algorithm of signing keys and issued signatures.
22323 @item @code{ksk-size} (default: @code{256})
22324 The length of the KSK. Note that this value is correct for the default
22325 algorithm, but would be unsecure for other algorithms.
22327 @item @code{zsk-size} (default: @code{256})
22328 The length of the ZSK. Note that this value is correct for the default
22329 algorithm, but would be unsecure for other algorithms.
22331 @item @code{dnskey-ttl} (default: @code{'default})
22332 The TTL value for DNSKEY records added into zone apex. The special
22333 @code{'default} value means same as the zone SOA TTL.
22335 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
22336 The period between ZSK publication and the next rollover initiation.
22338 @item @code{propagation-delay} (default: @code{(* 24 3600)})
22339 An extra delay added for each key rollover step. This value should be high
22340 enough to cover propagation of data from the master server to all slaves.
22342 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
22343 A validity period of newly issued signatures.
22345 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
22346 A period how long before a signature expiration the signature will be refreshed.
22348 @item @code{nsec3?} (default: @code{#f})
22349 When @code{#t}, NSEC3 will be used instead of NSEC.
22351 @item @code{nsec3-iterations} (default: @code{5})
22352 The number of additional times the hashing is performed.
22354 @item @code{nsec3-salt-length} (default: @code{8})
22355 The length of a salt field in octets, which is appended to the original owner
22356 name before hashing.
22358 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
22359 The validity period of newly issued salt field.
22364 @deftp {Data Type} knot-zone-configuration
22365 Data type representing a zone served by Knot.
22366 This type has the following parameters:
22369 @item @code{domain} (default: @code{""})
22370 The domain served by this configuration. It must not be empty.
22372 @item @code{file} (default: @code{""})
22373 The file where this zone is saved. This parameter is ignored by master zones.
22374 Empty means default location that depends on the domain name.
22376 @item @code{zone} (default: @code{(zone-file)})
22377 The content of the zone file. This parameter is ignored by slave zones. It
22378 must contain a zone-file record.
22380 @item @code{master} (default: @code{'()})
22381 A list of master remotes. When empty, this zone is a master. When set, this
22382 zone is a slave. This is a list of remotes identifiers.
22384 @item @code{ddns-master} (default: @code{#f})
22385 The main master. When empty, it defaults to the first master in the list of
22388 @item @code{notify} (default: @code{'()})
22389 A list of slave remote identifiers.
22391 @item @code{acl} (default: @code{'()})
22392 A list of acl identifiers.
22394 @item @code{semantic-checks?} (default: @code{#f})
22395 When set, this adds more semantic checks to the zone.
22397 @item @code{disable-any?} (default: @code{#f})
22398 When set, this forbids queries of the ANY type.
22400 @item @code{zonefile-sync} (default: @code{0})
22401 The delay between a modification in memory and on disk. 0 means immediate
22404 @item @code{zonefile-load} (default: @code{#f})
22405 The way the zone file contents are applied during zone load. Possible values
22409 @item @code{#f} for using the default value from Knot,
22410 @item @code{'none} for not using the zone file at all,
22411 @item @code{'difference} for computing the difference between already available
22412 contents and zone contents and applying it to the current zone contents,
22413 @item @code{'difference-no-serial} for the same as @code{'difference}, but
22414 ignoring the SOA serial in the zone file, while the server takes care of it
22416 @item @code{'whole} for loading zone contents from the zone file.
22419 @item @code{journal-content} (default: @code{#f})
22420 The way the journal is used to store zone and its changes. Possible values
22421 are @code{'none} to not use it at all, @code{'changes} to store changes and
22422 @code{'all} to store contents. @code{#f} does not set this option, so the
22423 default value from Knot is used.
22425 @item @code{max-journal-usage} (default: @code{#f})
22426 The maximum size for the journal on disk. @code{#f} does not set this option,
22427 so the default value from Knot is used.
22429 @item @code{max-journal-depth} (default: @code{#f})
22430 The maximum size of the history. @code{#f} does not set this option, so the
22431 default value from Knot is used.
22433 @item @code{max-zone-size} (default: @code{#f})
22434 The maximum size of the zone file. This limit is enforced for incoming
22435 transfer and updates. @code{#f} does not set this option, so the default
22436 value from Knot is used.
22438 @item @code{dnssec-policy} (default: @code{#f})
22439 A reference to a @code{knot-policy-configuration} record, or the special
22440 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
22443 @item @code{serial-policy} (default: @code{'increment})
22444 A policy between @code{'increment} and @code{'unixtime}.
22449 @deftp {Data Type} knot-configuration
22450 Data type representing the Knot configuration.
22451 This type has the following parameters:
22454 @item @code{knot} (default: @code{knot})
22457 @item @code{run-directory} (default: @code{"/var/run/knot"})
22458 The run directory. This directory will be used for pid file and sockets.
22460 @item @code{includes} (default: @code{'()})
22461 A list of strings or file-like objects denoting other files that must be
22462 included at the top of the configuration file.
22464 @cindex secrets, Knot service
22465 This can be used to manage secrets out-of-band. For example, secret
22466 keys may be stored in an out-of-band file not managed by Guix, and
22467 thus not visible in @file{/gnu/store}---e.g., you could store secret
22468 key configuration in @file{/etc/knot/secrets.conf} and add this file
22469 to the @code{includes} list.
22471 One can generate a secret tsig key (for nsupdate and zone transfers with the
22472 keymgr command from the knot package. Note that the package is not automatically
22473 installed by the service. The following example shows how to generate a new
22477 keymgr -t mysecret > /etc/knot/secrets.conf
22478 chmod 600 /etc/knot/secrets.conf
22481 Also note that the generated key will be named @var{mysecret}, so it is the
22482 name that needs to be used in the @var{key} field of the
22483 @code{knot-acl-configuration} record and in other places that need to refer
22486 It can also be used to add configuration not supported by this interface.
22488 @item @code{listen-v4} (default: @code{"0.0.0.0"})
22489 An ip address on which to listen.
22491 @item @code{listen-v6} (default: @code{"::"})
22492 An ip address on which to listen.
22494 @item @code{listen-port} (default: @code{53})
22495 A port on which to listen.
22497 @item @code{keys} (default: @code{'()})
22498 The list of knot-key-configuration used by this configuration.
22500 @item @code{acls} (default: @code{'()})
22501 The list of knot-acl-configuration used by this configuration.
22503 @item @code{remotes} (default: @code{'()})
22504 The list of knot-remote-configuration used by this configuration.
22506 @item @code{zones} (default: @code{'()})
22507 The list of knot-zone-configuration used by this configuration.
22512 @subsubheading Knot Resolver Service
22514 @deffn {Scheme Variable} knot-resolver-service-type
22515 This this the type of the knot resolver service, whose value should be
22516 an @code{knot-resolver-configuration} object as in this example:
22519 (service knot-resolver-service-type
22520 (knot-resolver-configuration
22521 (kresd-config-file (plain-file "kresd.conf" "
22522 net.listen('192.168.0.1', 5353)
22523 user('knot-resolver', 'knot-resolver')
22524 modules = @{ 'hints > iterate', 'stats', 'predict' @}
22525 cache.size = 100 * MB
22529 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
22532 @deftp {Data Type} knot-resolver-configuration
22533 Data type representing the configuration of knot-resolver.
22536 @item @code{package} (default: @var{knot-resolver})
22537 Package object of the knot DNS resolver.
22539 @item @code{kresd-config-file} (default: %kresd.conf)
22540 File-like object of the kresd configuration file to use, by default it
22541 will listen on @code{127.0.0.1} and @code{::1}.
22543 @item @code{garbage-collection-interval} (default: 1000)
22544 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
22550 @subsubheading Dnsmasq Service
22552 @deffn {Scheme Variable} dnsmasq-service-type
22553 This is the type of the dnsmasq service, whose value should be an
22554 @code{dnsmasq-configuration} object as in this example:
22557 (service dnsmasq-service-type
22558 (dnsmasq-configuration
22560 (servers '("192.168.1.1"))))
22564 @deftp {Data Type} dnsmasq-configuration
22565 Data type representing the configuration of dnsmasq.
22568 @item @code{package} (default: @var{dnsmasq})
22569 Package object of the dnsmasq server.
22571 @item @code{no-hosts?} (default: @code{#f})
22572 When true, don't read the hostnames in /etc/hosts.
22574 @item @code{port} (default: @code{53})
22575 The port to listen on. Setting this to zero completely disables DNS
22576 responses, leaving only DHCP and/or TFTP functions.
22578 @item @code{local-service?} (default: @code{#t})
22579 Accept DNS queries only from hosts whose address is on a local subnet,
22580 ie a subnet for which an interface exists on the server.
22582 @item @code{listen-addresses} (default: @code{'()})
22583 Listen on the given IP addresses.
22585 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
22586 The file to read the IP address of the upstream nameservers from.
22588 @item @code{no-resolv?} (default: @code{#f})
22589 When true, don't read @var{resolv-file}.
22591 @item @code{servers} (default: @code{'()})
22592 Specify IP address of upstream servers directly.
22594 @item @code{addresses} (default: @code{'()})
22595 For each entry, specify an IP address to return for any host in the
22596 given domains. Queries in the domains are never forwarded and always
22597 replied to with the specified IP address.
22599 This is useful for redirecting hosts locally, for example:
22602 (service dnsmasq-service-type
22603 (dnsmasq-configuration
22605 '(; Redirect to a local web-server.
22606 "/example.org/127.0.0.1"
22607 ; Redirect subdomain to a specific IP.
22608 "/subdomain.example.org/192.168.1.42"))))
22611 Note that rules in @file{/etc/hosts} take precedence over this.
22613 @item @code{cache-size} (default: @code{150})
22614 Set the size of dnsmasq's cache. Setting the cache size to zero
22617 @item @code{negative-cache?} (default: @code{#t})
22618 When false, disable negative caching.
22623 @subsubheading ddclient Service
22626 The ddclient service described below runs the ddclient daemon, which takes
22627 care of automatically updating DNS entries for service providers such as
22628 @uref{https://dyn.com/dns/, Dyn}.
22630 The following example show instantiates the service with its default
22634 (service ddclient-service-type)
22637 Note that ddclient needs to access credentials that are stored in a
22638 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
22639 @code{secret-file} below). You are expected to create this file manually, in
22640 an ``out-of-band'' fashion (you @emph{could} make this file part of the
22641 service configuration, for instance by using @code{plain-file}, but it will be
22642 world-readable @i{via} @file{/gnu/store}). See the examples in the
22643 @file{share/ddclient} directory of the @code{ddclient} package.
22645 @c %start of fragment
22647 Available @code{ddclient-configuration} fields are:
22649 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
22650 The ddclient package.
22654 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
22655 The period after which ddclient will retry to check IP and domain name.
22657 Defaults to @samp{300}.
22661 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
22662 Use syslog for the output.
22664 Defaults to @samp{#t}.
22668 @deftypevr {@code{ddclient-configuration} parameter} string mail
22671 Defaults to @samp{"root"}.
22675 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
22676 Mail failed update to user.
22678 Defaults to @samp{"root"}.
22682 @deftypevr {@code{ddclient-configuration} parameter} string pid
22683 The ddclient PID file.
22685 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
22689 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
22690 Enable SSL support.
22692 Defaults to @samp{#t}.
22696 @deftypevr {@code{ddclient-configuration} parameter} string user
22697 Specifies the user name or ID that is used when running ddclient
22700 Defaults to @samp{"ddclient"}.
22704 @deftypevr {@code{ddclient-configuration} parameter} string group
22705 Group of the user who will run the ddclient program.
22707 Defaults to @samp{"ddclient"}.
22711 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
22712 Secret file which will be appended to @file{ddclient.conf} file. This
22713 file contains credentials for use by ddclient. You are expected to
22714 create it manually.
22716 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
22720 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
22721 Extra options will be appended to @file{ddclient.conf} file.
22723 Defaults to @samp{()}.
22728 @c %end of fragment
22732 @subsection VPN Services
22733 @cindex VPN (virtual private network)
22734 @cindex virtual private network (VPN)
22736 The @code{(gnu services vpn)} module provides services related to
22737 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
22738 your machine to connect to a VPN, and a @emph{server} service for your machine
22739 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
22741 @deffn {Scheme Procedure} openvpn-client-service @
22742 [#:config (openvpn-client-configuration)]
22744 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
22747 @deffn {Scheme Procedure} openvpn-server-service @
22748 [#:config (openvpn-server-configuration)]
22750 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
22752 Both can be run simultaneously.
22755 @c %automatically generated documentation
22757 Available @code{openvpn-client-configuration} fields are:
22759 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
22760 The OpenVPN package.
22764 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
22765 The OpenVPN pid file.
22767 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
22771 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
22772 The protocol (UDP or TCP) used to open a channel between clients and
22775 Defaults to @samp{udp}.
22779 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
22780 The device type used to represent the VPN connection.
22782 Defaults to @samp{tun}.
22786 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
22787 The certificate authority to check connections against.
22789 Defaults to @samp{"/etc/openvpn/ca.crt"}.
22793 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
22794 The certificate of the machine the daemon is running on. It should be
22795 signed by the authority given in @code{ca}.
22797 Defaults to @samp{"/etc/openvpn/client.crt"}.
22801 @deftypevr {@code{openvpn-client-configuration} parameter} string key
22802 The key of the machine the daemon is running on. It must be the key whose
22803 certificate is @code{cert}.
22805 Defaults to @samp{"/etc/openvpn/client.key"}.
22809 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
22810 Whether to use the lzo compression algorithm.
22812 Defaults to @samp{#t}.
22816 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
22817 Don't re-read key files across SIGUSR1 or --ping-restart.
22819 Defaults to @samp{#t}.
22823 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
22824 Don't close and reopen TUN/TAP device or run up/down scripts across
22825 SIGUSR1 or --ping-restart restarts.
22827 Defaults to @samp{#t}.
22831 @deftypevr {@code{openvpn-client-configuration} parameter} boolean fast-io?
22832 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
22833 poll/epoll/select prior to the write operation.
22835 Defaults to @samp{#f}.
22838 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
22841 Defaults to @samp{3}.
22845 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
22846 Add an additional layer of HMAC authentication on top of the TLS control
22847 channel to protect against DoS attacks.
22849 Defaults to @samp{#f}.
22853 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string auth-user-pass
22854 Authenticate with server using username/password. The option is a file
22855 containing username/password on 2 lines. Do not use a file-like object as it
22856 would be added to the store and readable by any user.
22858 Defaults to @samp{'disabled}.
22861 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
22862 Whether to check the server certificate has server usage extension.
22864 Defaults to @samp{#t}.
22868 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
22869 Bind to a specific local port number.
22871 Defaults to @samp{#f}.
22875 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
22876 Retry resolving server address.
22878 Defaults to @samp{#t}.
22882 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
22883 A list of remote servers to connect to.
22885 Defaults to @samp{()}.
22887 Available @code{openvpn-remote-configuration} fields are:
22889 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
22892 Defaults to @samp{"my-server"}.
22896 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
22897 Port number the server listens to.
22899 Defaults to @samp{1194}.
22904 @c %end of automatic openvpn-client documentation
22906 @c %automatically generated documentation
22908 Available @code{openvpn-server-configuration} fields are:
22910 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
22911 The OpenVPN package.
22915 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
22916 The OpenVPN pid file.
22918 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
22922 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
22923 The protocol (UDP or TCP) used to open a channel between clients and
22926 Defaults to @samp{udp}.
22930 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
22931 The device type used to represent the VPN connection.
22933 Defaults to @samp{tun}.
22937 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
22938 The certificate authority to check connections against.
22940 Defaults to @samp{"/etc/openvpn/ca.crt"}.
22944 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
22945 The certificate of the machine the daemon is running on. It should be
22946 signed by the authority given in @code{ca}.
22948 Defaults to @samp{"/etc/openvpn/client.crt"}.
22952 @deftypevr {@code{openvpn-server-configuration} parameter} string key
22953 The key of the machine the daemon is running on. It must be the key whose
22954 certificate is @code{cert}.
22956 Defaults to @samp{"/etc/openvpn/client.key"}.
22960 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
22961 Whether to use the lzo compression algorithm.
22963 Defaults to @samp{#t}.
22967 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
22968 Don't re-read key files across SIGUSR1 or --ping-restart.
22970 Defaults to @samp{#t}.
22974 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
22975 Don't close and reopen TUN/TAP device or run up/down scripts across
22976 SIGUSR1 or --ping-restart restarts.
22978 Defaults to @samp{#t}.
22982 @deftypevr {@code{openvpn-server-configuration} parameter} boolean fast-io?
22983 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
22984 poll/epoll/select prior to the write operation.
22986 Defaults to @samp{#f}.
22989 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
22992 Defaults to @samp{3}.
22996 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
22997 Add an additional layer of HMAC authentication on top of the TLS control
22998 channel to protect against DoS attacks.
23000 Defaults to @samp{#f}.
23004 @deftypevr {@code{openvpn-server-configuration} parameter} number port
23005 Specifies the port number on which the server listens.
23007 Defaults to @samp{1194}.
23011 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
23012 An ip and mask specifying the subnet inside the virtual network.
23014 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
23018 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
23019 A CIDR notation specifying the IPv6 subnet inside the virtual network.
23021 Defaults to @samp{#f}.
23025 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
23026 The Diffie-Hellman parameters file.
23028 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
23032 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
23033 The file that records client IPs.
23035 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
23039 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
23040 When true, the server will act as a gateway for its clients.
23042 Defaults to @samp{#f}.
23046 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
23047 When true, clients are allowed to talk to each other inside the VPN.
23049 Defaults to @samp{#f}.
23053 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
23054 Causes ping-like messages to be sent back and forth over the link so
23055 that each side knows when the other side has gone down. @code{keepalive}
23056 requires a pair. The first element is the period of the ping sending,
23057 and the second element is the timeout before considering the other side
23062 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
23063 The maximum number of clients.
23065 Defaults to @samp{100}.
23069 @deftypevr {@code{openvpn-server-configuration} parameter} string status
23070 The status file. This file shows a small report on current connection.
23071 It is truncated and rewritten every minute.
23073 Defaults to @samp{"/var/run/openvpn/status"}.
23077 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
23078 The list of configuration for some clients.
23080 Defaults to @samp{()}.
23082 Available @code{openvpn-ccd-configuration} fields are:
23084 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
23087 Defaults to @samp{"client"}.
23091 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
23094 Defaults to @samp{#f}.
23098 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
23101 Defaults to @samp{#f}.
23108 @c %end of automatic openvpn-server documentation
23111 @node Network File System
23112 @subsection Network File System
23115 The @code{(gnu services nfs)} module provides the following services,
23116 which are most commonly used in relation to mounting or exporting
23117 directory trees as @dfn{network file systems} (NFS).
23119 While it is possible to use the individual components that together make
23120 up a Network File System service, we recommended to configure an NFS
23121 server with the @code{nfs-service-type}.
23123 @subsubheading NFS Service
23124 @cindex NFS, server
23126 The NFS service takes care of setting up all NFS component services,
23127 kernel configuration file systems, and installs configuration files in
23128 the locations that NFS expects.
23130 @defvr {Scheme Variable} nfs-service-type
23131 A service type for a complete NFS server.
23134 @deftp {Data Type} nfs-configuration
23135 This data type represents the configuration of the NFS service and all
23138 It has the following parameters:
23140 @item @code{nfs-utils} (default: @code{nfs-utils})
23141 The nfs-utils package to use.
23143 @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
23144 If a list of string values is provided, the @command{rpc.nfsd} daemon
23145 will be limited to supporting the given versions of the NFS protocol.
23147 @item @code{exports} (default: @code{'()})
23148 This is a list of directories the NFS server should export. Each entry
23149 is a list consisting of two elements: a directory name and a string
23150 containing all options. This is an example in which the directory
23151 @file{/export} is served to all NFS clients as a read-only share:
23157 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
23160 @item @code{rpcmountd-port} (default: @code{#f})
23161 The network port that the @command{rpc.mountd} daemon should use.
23163 @item @code{rpcstatd-port} (default: @code{#f})
23164 The network port that the @command{rpc.statd} daemon should use.
23166 @item @code{rpcbind} (default: @code{rpcbind})
23167 The rpcbind package to use.
23169 @item @code{idmap-domain} (default: @code{"localdomain"})
23170 The local NFSv4 domain name.
23172 @item @code{nfsd-port} (default: @code{2049})
23173 The network port that the @command{nfsd} daemon should use.
23175 @item @code{nfsd-threads} (default: @code{8})
23176 The number of threads used by the @command{nfsd} daemon.
23178 @item @code{nfsd-tcp?} (default: @code{#t})
23179 Whether the @command{nfsd} daemon should listen on a TCP socket.
23181 @item @code{nfsd-udp?} (default: @code{#f})
23182 Whether the @command{nfsd} daemon should listen on a UDP socket.
23184 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23185 The directory where the pipefs file system is mounted.
23187 @item @code{debug} (default: @code{'()"})
23188 A list of subsystems for which debugging output should be enabled. This
23189 is a list of symbols. Any of these symbols are valid: @code{nfsd},
23190 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
23194 If you don't need a complete NFS service or prefer to build it yourself
23195 you can use the individual component services that are documented below.
23197 @subsubheading RPC Bind Service
23200 The RPC Bind service provides a facility to map program numbers into
23201 universal addresses.
23202 Many NFS related services use this facility. Hence it is automatically
23203 started when a dependent service starts.
23205 @defvr {Scheme Variable} rpcbind-service-type
23206 A service type for the RPC portmapper daemon.
23210 @deftp {Data Type} rpcbind-configuration
23211 Data type representing the configuration of the RPC Bind Service.
23212 This type has the following parameters:
23214 @item @code{rpcbind} (default: @code{rpcbind})
23215 The rpcbind package to use.
23217 @item @code{warm-start?} (default: @code{#t})
23218 If this parameter is @code{#t}, then the daemon will read a
23219 state file on startup thus reloading state information saved by a previous
23225 @subsubheading Pipefs Pseudo File System
23229 The pipefs file system is used to transfer NFS related data
23230 between the kernel and user space programs.
23232 @defvr {Scheme Variable} pipefs-service-type
23233 A service type for the pipefs pseudo file system.
23236 @deftp {Data Type} pipefs-configuration
23237 Data type representing the configuration of the pipefs pseudo file system service.
23238 This type has the following parameters:
23240 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23241 The directory to which the file system is to be attached.
23246 @subsubheading GSS Daemon Service
23249 @cindex global security system
23251 The @dfn{global security system} (GSS) daemon provides strong security for RPC
23253 Before exchanging RPC requests an RPC client must establish a security
23254 context. Typically this is done using the Kerberos command @command{kinit}
23255 or automatically at login time using PAM services (@pxref{Kerberos Services}).
23257 @defvr {Scheme Variable} gss-service-type
23258 A service type for the Global Security System (GSS) daemon.
23261 @deftp {Data Type} gss-configuration
23262 Data type representing the configuration of the GSS daemon service.
23263 This type has the following parameters:
23265 @item @code{nfs-utils} (default: @code{nfs-utils})
23266 The package in which the @command{rpc.gssd} command is to be found.
23268 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23269 The directory where the pipefs file system is mounted.
23275 @subsubheading IDMAP Daemon Service
23277 @cindex name mapper
23279 The idmap daemon service provides mapping between user IDs and user names.
23280 Typically it is required in order to access file systems mounted via NFSv4.
23282 @defvr {Scheme Variable} idmap-service-type
23283 A service type for the Identity Mapper (IDMAP) daemon.
23286 @deftp {Data Type} idmap-configuration
23287 Data type representing the configuration of the IDMAP daemon service.
23288 This type has the following parameters:
23290 @item @code{nfs-utils} (default: @code{nfs-utils})
23291 The package in which the @command{rpc.idmapd} command is to be found.
23293 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23294 The directory where the pipefs file system is mounted.
23296 @item @code{domain} (default: @code{#f})
23297 The local NFSv4 domain name.
23298 This must be a string or @code{#f}.
23299 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
23301 @item @code{verbosity} (default: @code{0})
23302 The verbosity level of the daemon.
23307 @node Continuous Integration
23308 @subsection Continuous Integration
23310 @cindex continuous integration
23311 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
23312 continuous integration tool for Guix. It can be used both for development and
23313 for providing substitutes to others (@pxref{Substitutes}).
23315 The @code{(gnu services cuirass)} module provides the following service.
23317 @defvr {Scheme Procedure} cuirass-service-type
23318 The type of the Cuirass service. Its value must be a
23319 @code{cuirass-configuration} object, as described below.
23322 To add build jobs, you have to set the @code{specifications} field of the
23323 configuration. Here is an example of a service that polls the Guix repository
23324 and builds the packages from a manifest. Some of the packages are defined in
23325 the @code{"custom-packages"} input, which is the equivalent of
23326 @env{GUIX_PACKAGE_PATH}.
23329 (define %cuirass-specs
23331 '((#:name . "my-manifest")
23332 (#:load-path-inputs . ("guix"))
23333 (#:package-path-inputs . ("custom-packages"))
23334 (#:proc-input . "guix")
23335 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
23336 (#:proc . cuirass-jobs)
23337 (#:proc-args . ((subset . "manifests")
23338 (systems . ("x86_64-linux"))
23339 (manifests . (("config" . "guix/manifest.scm")))))
23340 (#:inputs . (((#:name . "guix")
23341 (#:url . "git://git.savannah.gnu.org/guix.git")
23342 (#:load-path . ".")
23343 (#:branch . "master")
23344 (#:no-compile? . #t))
23345 ((#:name . "config")
23346 (#:url . "https://git.example.org/config.git")
23347 (#:load-path . ".")
23348 (#:branch . "master")
23349 (#:no-compile? . #t))
23350 ((#:name . "custom-packages")
23351 (#:url . "https://git.example.org/custom-packages.git")
23352 (#:load-path . ".")
23353 (#:branch . "master")
23354 (#:no-compile? . #t)))))))
23356 (service cuirass-service-type
23357 (cuirass-configuration
23358 (specifications %cuirass-specs)))
23361 While information related to build jobs is located directly in the
23362 specifications, global settings for the @command{cuirass} process are
23363 accessible in other @code{cuirass-configuration} fields.
23365 @deftp {Data Type} cuirass-configuration
23366 Data type representing the configuration of Cuirass.
23369 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
23370 Location of the log file.
23372 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
23373 Location of the log file used by the web interface.
23375 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
23376 Location of the repository cache.
23378 @item @code{user} (default: @code{"cuirass"})
23379 Owner of the @code{cuirass} process.
23381 @item @code{group} (default: @code{"cuirass"})
23382 Owner's group of the @code{cuirass} process.
23384 @item @code{interval} (default: @code{60})
23385 Number of seconds between the poll of the repositories followed by the
23388 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
23389 Location of sqlite database which contains the build results and previously
23390 added specifications.
23392 @item @code{ttl} (default: @code{(* 30 24 3600)})
23393 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
23394 are registered for build results. This means that build results are protected
23395 from garbage collection for at least @var{ttl} seconds.
23397 @item @code{port} (default: @code{8081})
23398 Port number used by the HTTP server.
23400 @item @code{host} (default: @code{"localhost"})
23401 Listen on the network interface for @var{host}. The default is to
23402 accept connections from localhost.
23404 @item @code{specifications} (default: @code{#~'()})
23405 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
23406 where a specification is an association list
23407 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
23408 keys are keywords (@code{#:keyword-example}) as shown in the example
23411 @item @code{use-substitutes?} (default: @code{#f})
23412 This allows using substitutes to avoid building every dependencies of a job
23415 @item @code{one-shot?} (default: @code{#f})
23416 Only evaluate specifications and build derivations once.
23418 @item @code{fallback?} (default: @code{#f})
23419 When substituting a pre-built binary fails, fall back to building
23422 @item @code{extra-options} (default: @code{'()})
23423 Extra options to pass when running the Cuirass processes.
23425 @item @code{cuirass} (default: @code{cuirass})
23426 The Cuirass package to use.
23430 @node Power Management Services
23431 @subsection Power Management Services
23434 @cindex power management with TLP
23435 @subsubheading TLP daemon
23437 The @code{(gnu services pm)} module provides a Guix service definition
23438 for the Linux power management tool TLP.
23440 TLP enables various powersaving modes in userspace and kernel.
23441 Contrary to @code{upower-service}, it is not a passive,
23442 monitoring tool, as it will apply custom settings each time a new power
23443 source is detected. More information can be found at
23444 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
23446 @deffn {Scheme Variable} tlp-service-type
23447 The service type for the TLP tool. Its value should be a valid
23448 TLP configuration (see below). To use the default settings, simply
23451 (service tlp-service-type)
23455 By default TLP does not need much configuration but most TLP parameters
23456 can be tweaked using @code{tlp-configuration}.
23458 Each parameter definition is preceded by its type; for example,
23459 @samp{boolean foo} indicates that the @code{foo} parameter
23460 should be specified as a boolean. Types starting with
23461 @code{maybe-} denote parameters that won't show up in TLP config file
23462 when their value is @code{'disabled}.
23464 @c The following documentation was initially generated by
23465 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
23466 @c documentation is better, so we shouldn't hesitate to edit below as
23467 @c needed. However if the change you want to make to this documentation
23468 @c can be done in an automated way, it's probably easier to change
23469 @c (generate-documentation) than to make it below and have to deal with
23470 @c the churn as TLP updates.
23472 Available @code{tlp-configuration} fields are:
23474 @deftypevr {@code{tlp-configuration} parameter} package tlp
23479 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
23480 Set to true if you wish to enable TLP.
23482 Defaults to @samp{#t}.
23486 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
23487 Default mode when no power supply can be detected. Alternatives are AC
23490 Defaults to @samp{"AC"}.
23494 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
23495 Number of seconds Linux kernel has to wait after the disk goes idle,
23496 before syncing on AC.
23498 Defaults to @samp{0}.
23502 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
23503 Same as @code{disk-idle-ac} but on BAT mode.
23505 Defaults to @samp{2}.
23509 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
23510 Dirty pages flushing periodicity, expressed in seconds.
23512 Defaults to @samp{15}.
23516 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
23517 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
23519 Defaults to @samp{60}.
23523 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
23524 CPU frequency scaling governor on AC mode. With intel_pstate driver,
23525 alternatives are powersave and performance. With acpi-cpufreq driver,
23526 alternatives are ondemand, powersave, performance and conservative.
23528 Defaults to @samp{disabled}.
23532 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
23533 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
23535 Defaults to @samp{disabled}.
23539 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
23540 Set the min available frequency for the scaling governor on AC.
23542 Defaults to @samp{disabled}.
23546 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
23547 Set the max available frequency for the scaling governor on AC.
23549 Defaults to @samp{disabled}.
23553 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
23554 Set the min available frequency for the scaling governor on BAT.
23556 Defaults to @samp{disabled}.
23560 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
23561 Set the max available frequency for the scaling governor on BAT.
23563 Defaults to @samp{disabled}.
23567 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
23568 Limit the min P-state to control the power dissipation of the CPU, in AC
23569 mode. Values are stated as a percentage of the available performance.
23571 Defaults to @samp{disabled}.
23575 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
23576 Limit the max P-state to control the power dissipation of the CPU, in AC
23577 mode. Values are stated as a percentage of the available performance.
23579 Defaults to @samp{disabled}.
23583 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
23584 Same as @code{cpu-min-perf-on-ac} on BAT mode.
23586 Defaults to @samp{disabled}.
23590 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
23591 Same as @code{cpu-max-perf-on-ac} on BAT mode.
23593 Defaults to @samp{disabled}.
23597 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
23598 Enable CPU turbo boost feature on AC mode.
23600 Defaults to @samp{disabled}.
23604 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
23605 Same as @code{cpu-boost-on-ac?} on BAT mode.
23607 Defaults to @samp{disabled}.
23611 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
23612 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
23613 used under light load conditions.
23615 Defaults to @samp{#f}.
23619 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
23620 Same as @code{sched-powersave-on-ac?} but on BAT mode.
23622 Defaults to @samp{#t}.
23626 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
23627 Enable Linux kernel NMI watchdog.
23629 Defaults to @samp{#f}.
23633 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
23634 For Linux kernels with PHC patch applied, change CPU voltages. An
23635 example value would be @samp{"F:V F:V F:V F:V"}.
23637 Defaults to @samp{disabled}.
23641 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
23642 Set CPU performance versus energy saving policy on AC. Alternatives are
23643 performance, normal, powersave.
23645 Defaults to @samp{"performance"}.
23649 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
23650 Same as @code{energy-perf-policy-ac} but on BAT mode.
23652 Defaults to @samp{"powersave"}.
23656 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
23661 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
23662 Hard disk advanced power management level.
23666 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
23667 Same as @code{disk-apm-bat} but on BAT mode.
23671 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
23672 Hard disk spin down timeout. One value has to be specified for each
23673 declared hard disk.
23675 Defaults to @samp{disabled}.
23679 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
23680 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
23682 Defaults to @samp{disabled}.
23686 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
23687 Select IO scheduler for disk devices. One value has to be specified for
23688 each declared hard disk. Example alternatives are cfq, deadline and
23691 Defaults to @samp{disabled}.
23695 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
23696 SATA aggressive link power management (ALPM) level. Alternatives are
23697 min_power, medium_power, max_performance.
23699 Defaults to @samp{"max_performance"}.
23703 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
23704 Same as @code{sata-linkpwr-ac} but on BAT mode.
23706 Defaults to @samp{"min_power"}.
23710 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
23711 Exclude specified SATA host devices for link power management.
23713 Defaults to @samp{disabled}.
23717 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
23718 Enable Runtime Power Management for AHCI controller and disks on AC
23721 Defaults to @samp{disabled}.
23725 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
23726 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
23728 Defaults to @samp{disabled}.
23732 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
23733 Seconds of inactivity before disk is suspended.
23735 Defaults to @samp{15}.
23739 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
23740 PCI Express Active State Power Management level. Alternatives are
23741 default, performance, powersave.
23743 Defaults to @samp{"performance"}.
23747 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
23748 Same as @code{pcie-aspm-ac} but on BAT mode.
23750 Defaults to @samp{"powersave"}.
23754 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
23755 Radeon graphics clock speed level. Alternatives are low, mid, high,
23758 Defaults to @samp{"high"}.
23762 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
23763 Same as @code{radeon-power-ac} but on BAT mode.
23765 Defaults to @samp{"low"}.
23769 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
23770 Radeon dynamic power management method (DPM). Alternatives are battery,
23773 Defaults to @samp{"performance"}.
23777 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
23778 Same as @code{radeon-dpm-state-ac} but on BAT mode.
23780 Defaults to @samp{"battery"}.
23784 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
23785 Radeon DPM performance level. Alternatives are auto, low, high.
23787 Defaults to @samp{"auto"}.
23791 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
23792 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
23794 Defaults to @samp{"auto"}.
23798 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
23799 Wifi power saving mode.
23801 Defaults to @samp{#f}.
23805 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
23806 Same as @code{wifi-power-ac?} but on BAT mode.
23808 Defaults to @samp{#t}.
23812 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
23813 Disable wake on LAN.
23815 Defaults to @samp{#t}.
23819 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
23820 Timeout duration in seconds before activating audio power saving on
23821 Intel HDA and AC97 devices. A value of 0 disables power saving.
23823 Defaults to @samp{0}.
23827 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
23828 Same as @code{sound-powersave-ac} but on BAT mode.
23830 Defaults to @samp{1}.
23834 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
23835 Disable controller in powersaving mode on Intel HDA devices.
23837 Defaults to @samp{#t}.
23841 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
23842 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
23843 powered on again by releasing (and reinserting) the eject lever or by
23844 pressing the disc eject button on newer models.
23846 Defaults to @samp{#f}.
23850 @deftypevr {@code{tlp-configuration} parameter} string bay-device
23851 Name of the optical drive device to power off.
23853 Defaults to @samp{"sr0"}.
23857 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
23858 Runtime Power Management for PCI(e) bus devices. Alternatives are on
23861 Defaults to @samp{"on"}.
23865 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
23866 Same as @code{runtime-pm-ac} but on BAT mode.
23868 Defaults to @samp{"auto"}.
23872 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
23873 Runtime Power Management for all PCI(e) bus devices, except blacklisted
23876 Defaults to @samp{#t}.
23880 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
23881 Exclude specified PCI(e) device addresses from Runtime Power Management.
23883 Defaults to @samp{disabled}.
23887 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
23888 Exclude PCI(e) devices assigned to the specified drivers from Runtime
23893 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
23894 Enable USB autosuspend feature.
23896 Defaults to @samp{#t}.
23900 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
23901 Exclude specified devices from USB autosuspend.
23903 Defaults to @samp{disabled}.
23907 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
23908 Exclude WWAN devices from USB autosuspend.
23910 Defaults to @samp{#t}.
23914 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
23915 Include specified devices into USB autosuspend, even if they are already
23916 excluded by the driver or via @code{usb-blacklist-wwan?}.
23918 Defaults to @samp{disabled}.
23922 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
23923 Enable USB autosuspend before shutdown.
23925 Defaults to @samp{disabled}.
23929 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
23930 Restore radio device state (bluetooth, wifi, wwan) from previous
23931 shutdown on system startup.
23933 Defaults to @samp{#f}.
23938 @cindex CPU frequency scaling with thermald
23939 @subsubheading Thermald daemon
23941 The @code{(gnu services pm)} module provides an interface to
23942 thermald, a CPU frequency scaling service which helps prevent overheating.
23944 @defvr {Scheme Variable} thermald-service-type
23945 This is the service type for
23946 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
23947 Thermal Daemon, which is responsible for controlling the thermal state
23948 of processors and preventing overheating.
23951 @deftp {Data Type} thermald-configuration
23952 Data type representing the configuration of @code{thermald-service-type}.
23955 @item @code{ignore-cpuid-check?} (default: @code{#f})
23956 Ignore cpuid check for supported CPU models.
23958 @item @code{thermald} (default: @var{thermald})
23959 Package object of thermald.
23964 @node Audio Services
23965 @subsection Audio Services
23967 The @code{(gnu services audio)} module provides a service to start MPD
23968 (the Music Player Daemon).
23971 @subsubheading Music Player Daemon
23973 The Music Player Daemon (MPD) is a service that can play music while
23974 being controlled from the local machine or over the network by a variety
23977 The following example shows how one might run @code{mpd} as user
23978 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
23981 (service mpd-service-type
23987 @defvr {Scheme Variable} mpd-service-type
23988 The service type for @command{mpd}
23991 @deftp {Data Type} mpd-configuration
23992 Data type representing the configuration of @command{mpd}.
23995 @item @code{user} (default: @code{"mpd"})
23996 The user to run mpd as.
23998 @item @code{music-dir} (default: @code{"~/Music"})
23999 The directory to scan for music files.
24001 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
24002 The directory to store playlists.
24004 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
24005 The location of the music database.
24007 @item @code{state-file} (default: @code{"~/.mpd/state"})
24008 The location of the file that stores current MPD's state.
24010 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
24011 The location of the sticker database.
24013 @item @code{port} (default: @code{"6600"})
24014 The port to run mpd on.
24016 @item @code{address} (default: @code{"any"})
24017 The address that mpd will bind to. To use a Unix domain socket,
24018 an absolute path can be specified here.
24020 @item @code{outputs} (default: @code{"(list (mpd-output))"})
24021 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
24026 @deftp {Data Type} mpd-output
24027 Data type representing an @command{mpd} audio output.
24030 @item @code{name} (default: @code{"MPD"})
24031 The name of the audio output.
24033 @item @code{type} (default: @code{"pulse"})
24034 The type of audio output.
24036 @item @code{enabled?} (default: @code{#t})
24037 Specifies whether this audio output is enabled when MPD is started. By
24038 default, all audio outputs are enabled. This is just the default
24039 setting when there is no state file; with a state file, the previous
24042 @item @code{tags?} (default: @code{#t})
24043 If set to @code{#f}, then MPD will not send tags to this output. This
24044 is only useful for output plugins that can receive tags, for example the
24045 @code{httpd} output plugin.
24047 @item @code{always-on?} (default: @code{#f})
24048 If set to @code{#t}, then MPD attempts to keep this audio output always
24049 open. This may be useful for streaming servers, when you don’t want to
24050 disconnect all listeners even when playback is accidentally stopped.
24052 @item @code{mixer-type}
24053 This field accepts a symbol that specifies which mixer should be used
24054 for this audio output: the @code{hardware} mixer, the @code{software}
24055 mixer, the @code{null} mixer (allows setting the volume, but with no
24056 effect; this can be used as a trick to implement an external mixer
24057 External Mixer) or no mixer (@code{none}).
24059 @item @code{extra-options} (default: @code{'()"})
24060 An association list of option symbols to string values to be appended to
24061 the audio output configuration.
24066 The following example shows a configuration of @code{mpd} that provides
24067 an HTTP audio streaming output.
24070 (service mpd-service-type
24078 `((encoder . "vorbis")
24079 (port . "8080"))))))))
24083 @node Virtualization Services
24084 @subsection Virtualization services
24086 The @code{(gnu services virtualization)} module provides services for
24087 the libvirt and virtlog daemons, as well as other virtualization-related
24090 @subsubheading Libvirt daemon
24091 @code{libvirtd} is the server side daemon component of the libvirt
24092 virtualization management system. This daemon runs on host servers
24093 and performs required management tasks for virtualized guests.
24095 @deffn {Scheme Variable} libvirt-service-type
24096 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
24097 Its value must be a @code{libvirt-configuration}.
24100 (service libvirt-service-type
24101 (libvirt-configuration
24102 (unix-sock-group "libvirt")
24103 (tls-port "16555")))
24107 @c Auto-generated with (generate-libvirt-documentation)
24108 Available @code{libvirt-configuration} fields are:
24110 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
24115 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
24116 Flag listening for secure TLS connections on the public TCP/IP port.
24117 must set @code{listen} for this to have any effect.
24119 It is necessary to setup a CA and issue server certificates before using
24122 Defaults to @samp{#t}.
24126 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
24127 Listen for unencrypted TCP connections on the public TCP/IP port. must
24128 set @code{listen} for this to have any effect.
24130 Using the TCP socket requires SASL authentication by default. Only SASL
24131 mechanisms which support data encryption are allowed. This is
24132 DIGEST_MD5 and GSSAPI (Kerberos5)
24134 Defaults to @samp{#f}.
24138 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
24139 Port for accepting secure TLS connections This can be a port number, or
24142 Defaults to @samp{"16514"}.
24146 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
24147 Port for accepting insecure TCP connections This can be a port number,
24150 Defaults to @samp{"16509"}.
24154 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
24155 IP address or hostname used for client connections.
24157 Defaults to @samp{"0.0.0.0"}.
24161 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
24162 Flag toggling mDNS advertisement of the libvirt service.
24164 Alternatively can disable for all services on a host by stopping the
24167 Defaults to @samp{#f}.
24171 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
24172 Default mDNS advertisement name. This must be unique on the immediate
24175 Defaults to @samp{"Virtualization Host <hostname>"}.
24179 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
24180 UNIX domain socket group ownership. This can be used to allow a
24181 'trusted' set of users access to management capabilities without
24184 Defaults to @samp{"root"}.
24188 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
24189 UNIX socket permissions for the R/O socket. This is used for monitoring
24192 Defaults to @samp{"0777"}.
24196 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
24197 UNIX socket permissions for the R/W socket. Default allows only root.
24198 If PolicyKit is enabled on the socket, the default will change to allow
24199 everyone (eg, 0777)
24201 Defaults to @samp{"0770"}.
24205 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
24206 UNIX socket permissions for the admin socket. Default allows only owner
24207 (root), do not change it unless you are sure to whom you are exposing
24210 Defaults to @samp{"0777"}.
24214 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
24215 The directory in which sockets will be found/created.
24217 Defaults to @samp{"/var/run/libvirt"}.
24221 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
24222 Authentication scheme for UNIX read-only sockets. By default socket
24223 permissions allow anyone to connect
24225 Defaults to @samp{"polkit"}.
24229 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
24230 Authentication scheme for UNIX read-write sockets. By default socket
24231 permissions only allow root. If PolicyKit support was compiled into
24232 libvirt, the default will be to use 'polkit' auth.
24234 Defaults to @samp{"polkit"}.
24238 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
24239 Authentication scheme for TCP sockets. If you don't enable SASL, then
24240 all TCP traffic is cleartext. Don't do this outside of a dev/test
24243 Defaults to @samp{"sasl"}.
24247 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
24248 Authentication scheme for TLS sockets. TLS sockets already have
24249 encryption provided by the TLS layer, and limited authentication is done
24252 It is possible to make use of any SASL authentication mechanism as well,
24253 by using 'sasl' for this option
24255 Defaults to @samp{"none"}.
24259 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
24260 API access control scheme.
24262 By default an authenticated user is allowed access to all APIs. Access
24263 drivers can place restrictions on this.
24265 Defaults to @samp{()}.
24269 @deftypevr {@code{libvirt-configuration} parameter} string key-file
24270 Server key file path. If set to an empty string, then no private key is
24273 Defaults to @samp{""}.
24277 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
24278 Server key file path. If set to an empty string, then no certificate is
24281 Defaults to @samp{""}.
24285 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
24286 Server key file path. If set to an empty string, then no CA certificate
24289 Defaults to @samp{""}.
24293 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
24294 Certificate revocation list path. If set to an empty string, then no
24297 Defaults to @samp{""}.
24301 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
24302 Disable verification of our own server certificates.
24304 When libvirtd starts it performs some sanity checks against its own
24307 Defaults to @samp{#f}.
24311 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
24312 Disable verification of client certificates.
24314 Client certificate verification is the primary authentication mechanism.
24315 Any client which does not present a certificate signed by the CA will be
24318 Defaults to @samp{#f}.
24322 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
24323 Whitelist of allowed x509 Distinguished Name.
24325 Defaults to @samp{()}.
24329 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
24330 Whitelist of allowed SASL usernames. The format for username depends on
24331 the SASL authentication mechanism.
24333 Defaults to @samp{()}.
24337 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
24338 Override the compile time default TLS priority string. The default is
24339 usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
24340 is desired for libvirt to deviate from the global default settings.
24342 Defaults to @samp{"NORMAL"}.
24346 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
24347 Maximum number of concurrent client connections to allow over all
24350 Defaults to @samp{5000}.
24354 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
24355 Maximum length of queue of connections waiting to be accepted by the
24356 daemon. Note, that some protocols supporting retransmission may obey
24357 this so that a later reattempt at connection succeeds.
24359 Defaults to @samp{1000}.
24363 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
24364 Maximum length of queue of accepted but not yet authenticated clients.
24365 Set this to zero to turn this feature off
24367 Defaults to @samp{20}.
24371 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
24372 Number of workers to start up initially.
24374 Defaults to @samp{5}.
24378 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
24379 Maximum number of worker threads.
24381 If the number of active clients exceeds @code{min-workers}, then more
24382 threads are spawned, up to max_workers limit. Typically you'd want
24383 max_workers to equal maximum number of clients allowed.
24385 Defaults to @samp{20}.
24389 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
24390 Number of priority workers. If all workers from above pool are stuck,
24391 some calls marked as high priority (notably domainDestroy) can be
24392 executed in this pool.
24394 Defaults to @samp{5}.
24398 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
24399 Total global limit on concurrent RPC calls.
24401 Defaults to @samp{20}.
24405 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
24406 Limit on concurrent requests from a single client connection. To avoid
24407 one client monopolizing the server this should be a small fraction of
24408 the global max_requests and max_workers parameter.
24410 Defaults to @samp{5}.
24414 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
24415 Same as @code{min-workers} but for the admin interface.
24417 Defaults to @samp{1}.
24421 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
24422 Same as @code{max-workers} but for the admin interface.
24424 Defaults to @samp{5}.
24428 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
24429 Same as @code{max-clients} but for the admin interface.
24431 Defaults to @samp{5}.
24435 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
24436 Same as @code{max-queued-clients} but for the admin interface.
24438 Defaults to @samp{5}.
24442 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
24443 Same as @code{max-client-requests} but for the admin interface.
24445 Defaults to @samp{5}.
24449 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
24450 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
24452 Defaults to @samp{3}.
24456 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
24459 A filter allows to select a different logging level for a given category
24460 of logs The format for a filter is one of:
24471 where @code{name} is a string which is matched against the category
24472 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
24473 file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
24474 name in the filter can be a substring of the full category name, in
24475 order to match multiple similar categories), the optional @samp{"+"}
24476 prefix tells libvirt to log stack trace for each message matching name,
24477 and @code{x} is the minimal level where matching messages should be
24495 Multiple filters can be defined in a single filters statement, they just
24496 need to be separated by spaces.
24498 Defaults to @samp{"3:remote 4:event"}.
24502 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
24505 An output is one of the places to save logging information. The format
24506 for an output can be:
24510 output goes to stderr
24512 @item x:syslog:name
24513 use syslog for the output and use the given name as the ident
24515 @item x:file:file_path
24516 output to a file, with the given filepath
24519 output to journald logging system
24523 In all case the x prefix is the minimal level, acting as a filter
24540 Multiple outputs can be defined, they just need to be separated by
24543 Defaults to @samp{"3:stderr"}.
24547 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
24548 Allows usage of the auditing subsystem to be altered
24552 0: disable all auditing
24555 1: enable auditing, only if enabled on host
24558 2: enable auditing, and exit if disabled on host.
24562 Defaults to @samp{1}.
24566 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
24567 Send audit messages via libvirt logging infrastructure.
24569 Defaults to @samp{#f}.
24573 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
24574 Host UUID. UUID must not have all digits be the same.
24576 Defaults to @samp{""}.
24580 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
24581 Source to read host UUID.
24585 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
24588 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
24592 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
24595 Defaults to @samp{"smbios"}.
24599 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
24600 A keepalive message is sent to a client after @code{keepalive_interval}
24601 seconds of inactivity to check if the client is still responding. If
24602 set to -1, libvirtd will never send keepalive requests; however clients
24603 can still send them and the daemon will send responses.
24605 Defaults to @samp{5}.
24609 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
24610 Maximum number of keepalive messages that are allowed to be sent to the
24611 client without getting any response before the connection is considered
24614 In other words, the connection is automatically closed approximately
24615 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
24616 the last message received from the client. When @code{keepalive-count}
24617 is set to 0, connections will be automatically closed after
24618 @code{keepalive-interval} seconds of inactivity without sending any
24619 keepalive messages.
24621 Defaults to @samp{5}.
24625 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
24626 Same as above but for admin interface.
24628 Defaults to @samp{5}.
24632 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
24633 Same as above but for admin interface.
24635 Defaults to @samp{5}.
24639 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
24640 Timeout for Open vSwitch calls.
24642 The @code{ovs-vsctl} utility is used for the configuration and its
24643 timeout option is set by default to 5 seconds to avoid potential
24644 infinite waits blocking libvirt.
24646 Defaults to @samp{5}.
24650 @c %end of autogenerated docs
24652 @subsubheading Virtlog daemon
24653 The virtlogd service is a server side daemon component of libvirt that is
24654 used to manage logs from virtual machine consoles.
24656 This daemon is not used directly by libvirt client applications, rather it
24657 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
24658 standalone daemon, the main @code{libvirtd} daemon can be restarted without
24659 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
24660 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
24662 @deffn {Scheme Variable} virtlog-service-type
24663 This is the type of the virtlog daemon.
24664 Its value must be a @code{virtlog-configuration}.
24667 (service virtlog-service-type
24668 (virtlog-configuration
24669 (max-clients 1000)))
24673 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
24674 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
24676 Defaults to @samp{3}.
24680 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
24683 A filter allows to select a different logging level for a given category
24684 of logs The format for a filter is one of:
24695 where @code{name} is a string which is matched against the category
24696 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
24697 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
24698 be a substring of the full category name, in order to match multiple
24699 similar categories), the optional "+" prefix tells libvirt to log stack
24700 trace for each message matching name, and @code{x} is the minimal level
24701 where matching messages should be logged:
24718 Multiple filters can be defined in a single filters statement, they just
24719 need to be separated by spaces.
24721 Defaults to @samp{"3:remote 4:event"}.
24725 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
24728 An output is one of the places to save logging information The format
24729 for an output can be:
24733 output goes to stderr
24735 @item x:syslog:name
24736 use syslog for the output and use the given name as the ident
24738 @item x:file:file_path
24739 output to a file, with the given filepath
24742 output to journald logging system
24746 In all case the x prefix is the minimal level, acting as a filter
24763 Multiple outputs can be defined, they just need to be separated by
24766 Defaults to @samp{"3:stderr"}.
24770 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
24771 Maximum number of concurrent client connections to allow over all
24774 Defaults to @samp{1024}.
24778 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
24779 Maximum file size before rolling over.
24781 Defaults to @samp{2MB}
24785 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
24786 Maximum number of backup files to keep.
24788 Defaults to @samp{3}
24792 @subsubheading Transparent Emulation with QEMU
24795 @cindex @code{binfmt_misc}
24796 @code{qemu-binfmt-service-type} provides support for transparent
24797 emulation of program binaries built for different architectures---e.g.,
24798 it allows you to transparently execute an ARMv7 program on an x86_64
24799 machine. It achieves this by combining the @uref{https://www.qemu.org,
24800 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
24802 @defvr {Scheme Variable} qemu-binfmt-service-type
24803 This is the type of the QEMU/binfmt service for transparent emulation.
24804 Its value must be a @code{qemu-binfmt-configuration} object, which
24805 specifies the QEMU package to use as well as the architecture we want to
24809 (service qemu-binfmt-service-type
24810 (qemu-binfmt-configuration
24811 (platforms (lookup-qemu-platforms "arm" "aarch64"))))
24814 In this example, we enable transparent emulation for the ARM and aarch64
24815 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
24816 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
24817 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
24820 @deftp {Data Type} qemu-binfmt-configuration
24821 This is the configuration for the @code{qemu-binfmt} service.
24824 @item @code{platforms} (default: @code{'()})
24825 The list of emulated QEMU platforms. Each item must be a @dfn{platform
24826 object} as returned by @code{lookup-qemu-platforms} (see below).
24828 @item @code{guix-support?} (default: @code{#f})
24829 When it is true, QEMU and all its dependencies are added to the build
24830 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
24831 @option{--chroot-directory} option}). This allows the @code{binfmt_misc}
24832 handlers to be used within the build environment, which in turn means
24833 that you can transparently build programs for another architecture.
24835 For example, let's suppose you're on an x86_64 machine and you have this
24839 (service qemu-binfmt-service-type
24840 (qemu-binfmt-configuration
24841 (platforms (lookup-qemu-platforms "arm"))
24842 (guix-support? #t)))
24848 guix build -s armhf-linux inkscape
24852 and it will build Inkscape for ARMv7 @emph{as if it were a native
24853 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
24854 if you'd like to test a package build for an architecture you don't have
24857 @item @code{qemu} (default: @code{qemu})
24858 The QEMU package to use.
24862 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
24863 Return the list of QEMU platform objects corresponding to
24864 @var{platforms}@dots{}. @var{platforms} must be a list of strings
24865 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
24866 @code{"mips64el"}, and so on.
24869 @deffn {Scheme Procedure} qemu-platform? @var{obj}
24870 Return true if @var{obj} is a platform object.
24873 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
24874 Return the name of @var{platform}---a string such as @code{"arm"}.
24878 @subsubheading The Hurd in a Virtual Machine
24880 @cindex @code{hurd}
24883 Service @code{hurd-vm} provides support for running GNU/Hurd in a
24884 virtual machine (VM), a so-called ``Childhurd''. The virtual machine is
24885 a Shepherd service that can be referred to by the names @code{hurd-vm}
24886 and @code{childhurd} and be controlled with commands such as:
24890 herd stop childhurd
24893 The given GNU/Hurd operating system configuration is cross-compiled.
24895 @defvr {Scheme Variable} hurd-vm-service-type
24896 This is the type of the Hurd in a Virtual Machine service. Its value
24897 must be a @code{hurd-vm-configuration} object, which specifies the
24898 operating system (@pxref{operating-system Reference}) and the disk size
24899 for the Hurd Virtual Machine, the QEMU package to use as well as the
24900 options for running it.
24905 (service hurd-vm-service-type
24906 (hurd-vm-configuration
24907 (disk-size (* 5000 (expt 2 20))) ;5G
24908 (memory-size 1024))) ;1024MiB
24911 would create a disk image big enough to build GNU@tie{}Hello, with some
24915 @deftp {Data Type} hurd-vm-configuration
24916 The data type representing the configuration for
24917 @code{hurd-vm-service-type}.
24920 @item @code{os} (default: @var{%hurd-vm-operating-system})
24921 The operating system to instantiate. This default is bare-bones with a
24922 permissive OpenSSH secure shell daemon listening on port 2222
24923 (@pxref{Networking Services, @code{openssh-service-type}}).
24925 @item @code{qemu} (default: @code{qemu-minimal})
24926 The QEMU package to use.
24928 @item @code{image} (default: @var{hurd-vm-disk-image})
24929 The procedure used to build the disk-image built from this
24932 @item @code{disk-size} (default: @code{'guess})
24933 The size of the disk image.
24935 @item @code{memory-size} (default: @code{512})
24936 The memory size of the Virtual Machine in mebibytes.
24938 @item @code{options} (default: @code{'("--snapshot")})
24939 The extra options for running QEMU.
24941 @item @code{id} (default: @code{#f})
24942 If set, a non-zero positive integer used to parameterize Childhurd
24943 instances. It is appended to the service's name,
24944 e.g. @code{childhurd1}.
24946 @item @code{net-options} (default: @var{hurd-vm-net-options})
24947 The procedure used to produce the list of QEMU networking options.
24949 By default, it produces
24952 '("--device" "rtl8139,netdev=net0"
24953 "--netdev" "user,id=net0\
24954 ,hostfwd=tcp:127.0.0.1:<ssh-port>-:2222\
24955 ,hostfwd=tcp:127.0.0.1:<vnc-port>-:5900")
24957 with forwarded ports
24959 <ssh-port>: @code{(+ 10022 (* 1000 @var{ID}))}
24960 <vnc-port>: @code{(+ 15900 (* 1000 @var{ID}))}
24966 Note that by default the VM image is volatile, i.e., once stopped the
24967 contents are lost. If you want a stateful image instead, override the
24968 configuration's @code{image} and @code{options} without
24969 the @code{--snapshot} flag using something along these lines:
24972 (service hurd-vm-service-type
24973 (hurd-vm-configuration
24974 (image (const "/out/of/store/writable/hurd.img"))
24975 (options '("--hda"))))
24978 @subsubheading Ganeti
24983 This service is considered experimental. Configuration options may be changed
24984 in a backwards-incompatible manner, and not all features have been thorougly
24985 tested. Users of this service are encouraged to share their experience at
24986 @email{guix-devel@@gnu.org}.
24989 Ganeti is a virtual machine management system. It is designed to keep virtual
24990 machines running on a cluster of servers even in the event of hardware failures,
24991 and to make maintenance and recovery tasks easy. It consists of multiple
24992 services which are described later in this section. In addition to the Ganeti
24993 service, you will need the OpenSSH service (@pxref{Networking Services,
24994 @code{openssh-service-type}}), and update the @file{/etc/hosts} file
24995 (@pxref{operating-system Reference, @code{hosts-file}}) with the cluster name
24996 and address (or use a DNS server).
24998 All nodes participating in a Ganeti cluster should have the same Ganeti and
24999 @file{/etc/hosts} configuration. Here is an example configuration for a Ganeti
25000 cluster node that supports multiple storage backends, and installs the
25001 @code{debootstrap} and @code{guix} @dfn{OS providers}:
25004 (use-package-modules virtualization)
25005 (use-service-modules base ganeti networking ssh)
25008 (host-name "node1")
25009 (hosts-file (plain-file "hosts" (format #f "
25010 127.0.0.1 localhost
25013 192.168.1.200 ganeti.example.com
25014 192.168.1.201 node1.example.com node1
25015 192.168.1.202 node2.example.com node2
25018 ;; Install QEMU so we can use KVM-based instances, and LVM, DRBD and Ceph
25019 ;; in order to use the "plain", "drbd" and "rbd" storage backends.
25020 (packages (append (map specification->package
25021 '("qemu" "lvm2" "drbd-utils" "ceph"
25022 ;; Add the debootstrap and guix OS providers.
25023 "ganeti-instance-guix" "ganeti-instance-debootstrap"))
25026 (append (list (static-networking-service "eth0" "192.168.1.201"
25027 #:netmask "255.255.255.0"
25028 #:gateway "192.168.1.254"
25029 #:name-servers '("192.168.1.252"
25032 ;; Ganeti uses SSH to communicate between nodes.
25033 (service openssh-service-type
25034 (openssh-configuration
25035 (permit-root-login 'without-password)))
25037 (service ganeti-service-type
25038 (ganeti-configuration
25039 ;; This list specifies allowed file system paths
25040 ;; for storing virtual machine images.
25041 (file-storage-paths '("/srv/ganeti/file-storage"))
25042 ;; This variable configures a single "variant" for
25043 ;; both Debootstrap and Guix that works with KVM.
25044 (os %default-ganeti-os))))
25048 Users are advised to read the
25049 @url{http://docs.ganeti.org/ganeti/master/html/admin.html,Ganeti
25050 administrators guide} to learn about the various cluster options and
25051 day-to-day operations. There is also a
25052 @url{https://guix.gnu.org/blog/2020/ganeti-on-guix/,blog post}
25053 describing how to configure and initialize a small cluster.
25055 @defvr {Scheme Variable} ganeti-service-type
25056 This is a service type that includes all the various services that Ganeti
25059 Its value is a @code{ganeti-configuration} object that defines the package
25060 to use for CLI operations, as well as configuration for the various daemons.
25061 Allowed file storage paths and available guest operating systems are also
25062 configured through this data type.
25065 @deftp {Data Type} ganeti-configuration
25066 The @code{ganeti} service takes the following configuration options:
25069 @item @code{ganeti} (default: @code{ganeti})
25070 The @code{ganeti} package to use. It will be installed to the system profile
25071 and make @command{gnt-cluster}, @command{gnt-instance}, etc available. Note
25072 that the value specified here does not affect the other services as each refer
25073 to a specific @code{ganeti} package (see below).
25075 @item @code{noded-configuration} (default: @code{(ganeti-noded-configuration)})
25076 @itemx @code{confd-configuration} (default: @code{(ganeti-confd-configuration)})
25077 @itemx @code{wconfd-configuration} (default: @code{(ganeti-wconfd-configuration)})
25078 @itemx @code{luxid-configuration} (default: @code{(ganeti-luxid-configuration)})
25079 @itemx @code{rapi-configuration} (default: @code{(ganeti-rapi-configuration)})
25080 @itemx @code{kvmd-configuration} (default: @code{(ganeti-kvmd-configuration)})
25081 @itemx @code{mond-configuration} (default: @code{(ganeti-mond-configuration)})
25082 @itemx @code{metad-configuration} (default: @code{(ganeti-metad-configuration)})
25083 @itemx @code{watcher-configuration} (default: @code{(ganeti-watcher-configuration)})
25084 @itemx @code{cleaner-configuration} (default: @code{(ganeti-cleaner-configuration)})
25086 These options control the various daemons and cron jobs that are distributed
25087 with Ganeti. The possible values for these are described in detail below.
25088 To override a setting, you must use the configuration type for that service:
25091 (service ganeti-service-type
25092 (ganeti-configuration
25093 (rapi-configuration
25094 (ganeti-rapi-configuration
25095 (interface "eth1"))))
25096 (watcher-configuration
25097 (ganeti-watcher-configuration
25098 (rapi-ip "10.0.0.1"))))
25101 @item @code{file-storage-paths} (default: @code{'()})
25102 List of allowed directories for file storage backend.
25104 @item @code{os} (default: @code{%default-ganeti-os})
25105 List of @code{<ganeti-os>} records.
25108 In essence @code{ganeti-service-type} is shorthand for declaring each service
25112 (service ganeti-noded-service-type)
25113 (service ganeti-confd-service-type)
25114 (service ganeti-wconfd-service-type)
25115 (service ganeti-luxid-service-type)
25116 (service ganeti-kvmd-service-type)
25117 (service ganeti-mond-service-type)
25118 (service ganeti-metad-service-type)
25119 (service ganeti-watcher-service-type)
25120 (service ganeti-cleaner-service-type)
25123 Plus a service extension for @code{etc-service-type} that configures the file
25124 storage backend and OS variants.
25128 @deftp {Data Type} ganeti-os
25129 This data type is suitable for passing to the @code{os} parameter of
25130 @code{ganeti-configuration}. It takes the following parameters:
25134 The name for this OS provider. It is only used to specify where the
25135 configuration ends up. Setting it to ``debootstrap'' will create
25136 @file{/etc/ganeti/instance-debootstrap}.
25138 @item @code{extension}
25139 The file extension for variants of this OS type. For example
25140 @file{.conf} or @file{.scm}.
25142 @item @code{variants} (default: @code{'()})
25143 List of @code{ganeti-os-variant} objects for this OS.
25148 @deftp {Data Type} ganeti-os-variant
25149 This is the data type for a Ganeti OS variant. It takes the following
25154 The name of this variant.
25156 @item @code{configuration}
25157 A configuration file for this variant.
25161 @defvr {Scheme Variable} %default-debootstrap-hooks
25162 This variable contains hooks to configure networking and the GRUB bootloader.
25165 @defvr {Scheme Variable} %default-debootstrap-extra-pkgs
25166 This variable contains a list of packages suitable for a fully-virtualized guest.
25169 @deftp {Data Type} debootstrap-configuration
25171 This data type creates configuration files suitable for the debootstrap OS provider.
25174 @item @code{hooks} (default: @code{%default-debootstrap-hooks})
25175 When not @code{#f}, this must be a G-expression that specifies a directory with
25176 scripts that will run when the OS is installed. It can also be a list of
25177 @code{(name . file-like)} pairs. For example:
25180 `((99-hello-world . ,(plain-file "#!/bin/sh\necho Hello, World")))
25183 That will create a directory with one executable named @code{99-hello-world}
25184 and run it every time this variant is installed. If set to @code{#f}, hooks
25185 in @file{/etc/ganeti/instance-debootstrap/hooks} will be used, if any.
25186 @item @code{proxy} (default: @code{#f})
25187 Optional HTTP proxy to use.
25188 @item @code{mirror} (default: @code{#f})
25189 The Debian mirror. Typically something like @code{http://ftp.no.debian.org/debian}.
25190 The default varies depending on the distribution.
25191 @item @code{arch} (default: @code{#f})
25192 The dpkg architecture. Set to @code{armhf} to debootstrap an ARMv7 instance
25193 on an AArch64 host. Default is to use the current system architecture.
25194 @item @code{suite} (default: @code{"stable"})
25195 When set, this must be a Debian distribution ``suite'' such as @code{buster}
25196 or @code{focal}. If set to @code{#f}, the default for the OS provider is used.
25197 @item @code{extra-pkgs} (default: @code{%default-debootstrap-extra-pkgs})
25198 List of extra packages that will get installed by dpkg in addition
25199 to the minimal system.
25200 @item @code{components} (default: @code{#f})
25201 When set, must be a list of Debian repository ``components''. For example
25202 @code{'("main" "contrib")}.
25203 @item @code{generate-cache?} (default: @code{#t})
25204 Whether to automatically cache the generated debootstrap archive.
25205 @item @code{clean-cache} (default: @code{14})
25206 Discard the cache after this amount of days. Use @code{#f} to never
25208 @item @code{partition-style} (default: @code{'msdos})
25209 The type of partition to create. When set, it must be one of
25210 @code{'msdos}, @code{'none} or a string.
25211 @item @code{partition-alignment} (default: @code{2048})
25212 Alignment of the partition in sectors.
25216 @deffn {Scheme Procedure} debootstrap-variant @var{name} @var{configuration}
25217 This is a helper procedure that creates a @code{ganeti-os-variant} record. It
25218 takes two parameters: a name and a @code{debootstrap-configuration} object.
25221 @deffn {Scheme Procedure} debootstrap-os @var{variants}@dots{}
25222 This is a helper procedure that creates a @code{ganeti-os} record. It takes
25223 a list of variants created with @code{debootstrap-variant}.
25226 @deffn {Scheme Procedure} guix-variant @var{name} @var{configuration}
25227 This is a helper procedure that creates a @code{ganeti-os-variant} record for
25228 use with the Guix OS provider. It takes a name and a G-expression that returns
25229 a ``file-like'' (@pxref{G-Expressions, file-like objects}) object containing a
25230 Guix System configuration.
25233 @deffn {Scheme Procedure} guix-os @var{variants}@dots{}
25234 This is a helper procedure that creates a @code{ganeti-os} record. It
25235 takes a list of variants produced by @code{guix-variant}.
25238 @defvr {Scheme Variable} %default-debootstrap-variants
25239 This is a convenience variable to make the debootstrap provider work
25240 ``out of the box'' without users having to declare variants manually. It
25241 contains a single debootstrap variant with the default configuration:
25244 (list (debootstrap-variant
25246 (debootstrap-configuration)))
25250 @defvr {Scheme Variable} %default-guix-variants
25251 This is a convenience variable to make the Guix OS provider work without
25252 additional configuration. It creates a virtual machine that has an SSH
25253 server, a serial console, and authorizes the Ganeti hosts SSH keys.
25256 (list (guix-variant
25258 (file-append ganeti-instance-guix
25259 "/share/doc/ganeti-instance-guix/examples/dynamic.scm")))
25263 Users can implement support for OS providers unbeknownst to Guix by extending
25264 the @code{ganeti-os} and @code{ganeti-os-variant} records appropriately.
25270 (extension ".conf")
25272 (list (ganeti-os-variant
25274 (configuration (plain-file "bar" "this is fine"))))))
25277 That creates @file{/etc/ganeti/instance-custom/variants/foo.conf} which points
25278 to a file in the store with contents @code{this is fine}. It also creates
25279 @file{/etc/ganeti/instance-custom/variants/variants.list} with contents @code{foo}.
25281 Obviously this may not work for all OS providers out there. If you find the
25282 interface limiting, please reach out to @email{guix-devel@@gnu.org}.
25284 The rest of this section documents the various services that are included by
25285 @code{ganeti-service-type}.
25287 @defvr {Scheme Variable} ganeti-noded-service-type
25288 @command{ganeti-noded} is the daemon responsible for node-specific functions
25289 within the Ganeti system. The value of this service must be a
25290 @code{ganeti-noded-configuration} object.
25293 @deftp {Data Type} ganeti-noded-configuration
25294 This is the configuration for the @code{ganeti-noded} service.
25297 @item @code{ganeti} (default: @code{ganeti})
25298 The @code{ganeti} package to use for this service.
25300 @item @code{port} (default: @code{1811})
25301 The TCP port on which the node daemon listens for network requests.
25303 @item @code{address} (default: @code{"0.0.0.0"})
25304 The network address that the daemon will bind to. The default address means
25305 bind to all available addresses.
25307 @item @code{interface} (default: @code{#f})
25308 When this is set, it must be a specific network interface (e.g.@: @code{eth0})
25309 that the daemon will bind to.
25311 @item @code{max-clients} (default: @code{20})
25312 This sets a limit on the maximum number of simultaneous client connections
25313 that the daemon will handle. Connections above this count are accepted, but
25314 no responses will be sent until enough connections have closed.
25316 @item @code{ssl?} (default: @code{#t})
25317 Whether to use SSL/TLS to encrypt network communications. The certificate
25318 is automatically provisioned by the cluster and can be rotated with
25319 @command{gnt-cluster renew-crypto}.
25321 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
25322 This can be used to provide a specific encryption key for TLS communications.
25324 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
25325 This can be used to provide a specific certificate for TLS communications.
25327 @item @code{debug?} (default: @code{#f})
25328 When true, the daemon performs additional logging for debugging purposes.
25329 Note that this will leak encryption details to the log files, use with caution.
25334 @defvr {Scheme Variable} ganeti-confd-service-type
25335 @command{ganeti-confd} answers queries related to the configuration of a
25336 Ganeti cluster. The purpose of this daemon is to have a highly available
25337 and fast way to query cluster configuration values. It is automatically
25338 active on all @dfn{master candidates}. The value of this service must be a
25339 @code{ganeti-confd-configuration} object.
25343 @deftp {Data Type} ganeti-confd-configuration
25344 This is the configuration for the @code{ganeti-confd} service.
25347 @item @code{ganeti} (default: @code{ganeti})
25348 The @code{ganeti} package to use for this service.
25350 @item @code{port} (default: @code{1814})
25351 The UDP port on which to listen for network requests.
25353 @item @code{address} (default: @code{"0.0.0.0"})
25354 Network address that the daemon will bind to.
25356 @item @code{debug?} (default: @code{#f})
25357 When true, the daemon performs additional logging for debugging purposes.
25362 @defvr {Scheme Variable} ganeti-wconfd-service-type
25363 @command{ganeti-wconfd} is the daemon that has authoritative knowledge
25364 about the cluster configuration and is the only entity that can accept
25365 changes to it. All jobs that need to modify the configuration will do so
25366 by sending appropriate requests to this daemon. It only runs on the
25367 @dfn{master node} and will automatically disable itself on other nodes.
25369 The value of this service must be a
25370 @code{ganeti-wconfd-configuration} object.
25373 @deftp {Data Type} ganeti-wconfd-configuration
25374 This is the configuration for the @code{ganeti-wconfd} service.
25377 @item @code{ganeti} (default: @code{ganeti})
25378 The @code{ganeti} package to use for this service.
25380 @item @code{no-voting?} (default: @code{#f})
25381 The daemon will refuse to start if the majority of cluster nodes does not
25382 agree that it is running on the master node. Set to @code{#t} to start
25383 even if a quorum can not be reached (dangerous, use with caution).
25385 @item @code{debug?} (default: @code{#f})
25386 When true, the daemon performs additional logging for debugging purposes.
25391 @defvr {Scheme Variable} ganeti-luxid-service-type
25392 @command{ganeti-luxid} is a daemon used to answer queries related to the
25393 configuration and the current live state of a Ganeti cluster. Additionally,
25394 it is the authorative daemon for the Ganeti job queue. Jobs can be
25395 submitted via this daemon and it schedules and starts them.
25397 It takes a @code{ganeti-luxid-configuration} object.
25400 @deftp {Data Type} ganeti-luxid-configuration
25401 This is the configuration for the @code{ganeti-wconfd} service.
25404 @item @code{ganeti} (default: @code{ganeti})
25405 The @code{ganeti} package to use for this service.
25407 @item @code{no-voting?} (default: @code{#f})
25408 The daemon will refuse to start if it cannot verify that the majority of
25409 cluster nodes believes that it is running on the master node. Set to
25410 @code{#t} to ignore such checks and start anyway (this can be dangerous).
25412 @item @code{debug?} (default: @code{#f})
25413 When true, the daemon performs additional logging for debugging purposes.
25418 @defvr {Scheme Variable} ganeti-rapi-service-type
25419 @command{ganeti-rapi} provides a remote API for Ganeti clusters. It runs on
25420 the master node and can be used to perform cluster actions programmatically
25421 via a JSON-based RPC protocol.
25423 Most query operations are allowed without authentication (unless
25424 @var{require-authentication?} is set), whereas write operations require
25425 explicit authorization via the @file{/var/lib/ganeti/rapi/users} file. See
25426 the @url{http://docs.ganeti.org/ganeti/master/html/rapi.html, Ganeti Remote
25427 API documentation} for more information.
25429 The value of this service must be a @code{ganeti-rapi-configuration} object.
25432 @deftp {Data Type} ganeti-rapi-configuration
25433 This is the configuration for the @code{ganeti-rapi} service.
25436 @item @code{ganeti} (default: @code{ganeti})
25437 The @code{ganeti} package to use for this service.
25439 @item @code{require-authentication?} (default: @code{#f})
25440 Whether to require authentication even for read-only operations.
25442 @item @code{port} (default: @code{5080})
25443 The TCP port on which to listen to API requests.
25445 @item @code{address} (default: @code{"0.0.0.0"})
25446 The network address that the service will bind to. By default it listens
25447 on all configured addresses.
25449 @item @code{interface} (default: @code{#f})
25450 When set, it must specify a specific network interface such as @code{eth0}
25451 that the daemon will bind to.
25453 @item @code{max-clients} (default: @code{20})
25454 The maximum number of simultaneous client requests to handle. Further
25455 connections are allowed, but no responses are sent until enough connections
25458 @item @code{ssl?} (default: @code{#f})
25459 Whether to use SSL/TLS encryption on the RAPI port.
25461 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
25462 This can be used to provide a specific encryption key for TLS communications.
25464 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
25465 This can be used to provide a specific certificate for TLS communications.
25467 @item @code{debug?} (default: @code{#f})
25468 When true, the daemon performs additional logging for debugging purposes.
25469 Note that this will leak encryption details to the log files, use with caution.
25474 @defvr {Scheme Variable} ganeti-kvmd-service-type
25475 @command{ganeti-kvmd} is responsible for determining whether a given KVM
25476 instance was shut down by an administrator or a user. Normally Ganeti will
25477 restart an instance that was not stopped through Ganeti itself. If the
25478 cluster option @code{user_shutdown} is true, this daemon monitors the
25479 @code{QMP} socket provided by QEMU and listens for shutdown events, and
25480 marks the instance as @dfn{USER_down} instead of @dfn{ERROR_down} when
25481 it shuts down gracefully by itself.
25483 It takes a @code{ganeti-kvmd-configuration} object.
25486 @deftp {Data Type} ganeti-kvmd-configuration
25489 @item @code{ganeti} (default: @code{ganeti})
25490 The @code{ganeti} package to use for this service.
25492 @item @code{debug?} (default: @code{#f})
25493 When true, the daemon performs additional logging for debugging purposes.
25498 @defvr {Scheme Variable} ganeti-mond-service-type
25499 @command{ganeti-mond} is an optional daemon that provides Ganeti monitoring
25500 functionality. It is responsible for running data collectors and publish the
25501 collected information through a HTTP interface.
25503 It takes a @code{ganeti-mond-configuration} object.
25506 @deftp {Data Type} ganeti-mond-configuration
25509 @item @code{ganeti} (default: @code{ganeti})
25510 The @code{ganeti} package to use for this service.
25512 @item @code{port} (default: @code{1815})
25513 The port on which the daemon will listen.
25515 @item @code{address} (default: @code{"0.0.0.0"})
25516 The network address that the daemon will bind to. By default it binds to all
25517 available interfaces.
25519 @item @code{debug?} (default: @code{#f})
25520 When true, the daemon performs additional logging for debugging purposes.
25525 @defvr {Scheme Variable} ganeti-metad-service-type
25526 @command{ganeti-metad} is an optional daemon that can be used to provide
25527 information about the cluster to instances or OS install scripts.
25529 It takes a @code{ganeti-metad-configuration} object.
25532 @deftp {Data Type} ganeti-metad-configuration
25535 @item @code{ganeti} (default: @code{ganeti})
25536 The @code{ganeti} package to use for this service.
25538 @item @code{port} (default: @code{80})
25539 The port on which the daemon will listen.
25541 @item @code{address} (default: @code{#f})
25542 If set, the daemon will bind to this address only. If left unset, the behavior
25543 depends on the cluster configuration.
25545 @item @code{debug?} (default: @code{#f})
25546 When true, the daemon performs additional logging for debugging purposes.
25551 @defvr {Scheme Variable} ganeti-watcher-service-type
25552 @command{ganeti-watcher} is a script designed to run periodically and ensure
25553 the health of a cluster. It will automatically restart instances that have
25554 stopped without Ganetis consent, and repairs DRBD links in case a node has
25555 rebooted. It also archives old cluster jobs and restarts Ganeti daemons
25556 that are not running. If the cluster parameter @code{ensure_node_health}
25557 is set, the watcher will also shutdown instances and DRBD devices if the
25558 node it is running on is declared offline by known master candidates.
25560 It can be paused on all nodes with @command{gnt-cluster watcher pause}.
25562 The service takes a @code{ganeti-watcher-configuration} object.
25565 @deftp {Data Type} ganeti-watcher-configuration
25568 @item @code{ganeti} (default: @code{ganeti})
25569 The @code{ganeti} package to use for this service.
25571 @item @code{schedule} (default: @code{'(next-second-from (next-minute (range 0 60 5)))})
25572 How often to run the script. The default is every five minutes.
25574 @item @code{rapi-ip} (default: @code{#f})
25575 This option needs to be specified only if the RAPI daemon is configured to use
25576 a particular interface or address. By default the cluster address is used.
25578 @item @code{job-age} (default: @code{(* 6 3600)})
25579 Archive cluster jobs older than this age, specified in seconds. The default
25580 is 6 hours. This keeps @command{gnt-job list} manageable.
25582 @item @code{verify-disks?} (default: @code{#t})
25583 If this is @code{#f}, the watcher will not try to repair broken DRBD links
25584 automatically. Administrators will need to use @command{gnt-cluster verify-disks}
25587 @item @code{debug?} (default: @code{#f})
25588 When @code{#t}, the script performs additional logging for debugging purposes.
25593 @defvr {Scheme Variable} ganeti-cleaner-service-type
25594 @command{ganeti-cleaner} is a script designed to run periodically and remove
25595 old files from the cluster. This service type controls two @dfn{cron jobs}:
25596 one intended for the master node that permanently purges old cluster jobs,
25597 and one intended for every node that removes expired X509 certificates, keys,
25598 and outdated @command{ganeti-watcher} information. Like all Ganeti services,
25599 it is safe to include even on non-master nodes as it will disable itself as
25602 It takes a @code{ganeti-cleaner-configuration} object.
25605 @deftp {Data Type} ganeti-cleaner-configuration
25608 @item @code{ganeti} (default: @code{ganeti})
25609 The @code{ganeti} package to use for the @command{gnt-cleaner} command.
25611 @item @code{master-schedule} (default: @code{"45 1 * * *"})
25612 How often to run the master cleaning job. The default is once per day, at
25615 @item @code{node-schedule} (default: @code{"45 2 * * *"})
25616 How often to run the node cleaning job. The default is once per day, at
25622 @node Version Control Services
25623 @subsection Version Control Services
25625 The @code{(gnu services version-control)} module provides a service to
25626 allow remote access to local Git repositories. There are three options:
25627 the @code{git-daemon-service}, which provides access to repositories via
25628 the @code{git://} unsecured TCP-based protocol, extending the
25629 @code{nginx} web server to proxy some requests to
25630 @code{git-http-backend}, or providing a web interface with
25631 @code{cgit-service-type}.
25633 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
25635 Return a service that runs @command{git daemon}, a simple TCP server to
25636 expose repositories over the Git protocol for anonymous access.
25638 The optional @var{config} argument should be a
25639 @code{<git-daemon-configuration>} object, by default it allows read-only
25640 access to exported@footnote{By creating the magic file
25641 @file{git-daemon-export-ok} in the repository directory.} repositories under
25646 @deftp {Data Type} git-daemon-configuration
25647 Data type representing the configuration for @code{git-daemon-service}.
25650 @item @code{package} (default: @code{git})
25651 Package object of the Git distributed version control system.
25653 @item @code{export-all?} (default: @code{#f})
25654 Whether to allow access for all Git repositories, even if they do not
25655 have the @file{git-daemon-export-ok} file.
25657 @item @code{base-path} (default: @file{/srv/git})
25658 Whether to remap all the path requests as relative to the given path.
25659 If you run @command{git daemon} with @code{(base-path "/srv/git")} on
25660 @samp{example.com}, then if you later try to pull
25661 @indicateurl{git://example.com/hello.git}, git daemon will interpret the
25662 path as @file{/srv/git/hello.git}.
25664 @item @code{user-path} (default: @code{#f})
25665 Whether to allow @code{~user} notation to be used in requests. When
25666 specified with empty string, requests to
25667 @indicateurl{git://host/~alice/foo} is taken as a request to access
25668 @code{foo} repository in the home directory of user @code{alice}. If
25669 @code{(user-path "@var{path}")} is specified, the same request is taken
25670 as a request to access @file{@var{path}/foo} repository in the home
25671 directory of user @code{alice}.
25673 @item @code{listen} (default: @code{'()})
25674 Whether to listen on specific IP addresses or hostnames, defaults to
25677 @item @code{port} (default: @code{#f})
25678 Whether to listen on an alternative port, which defaults to 9418.
25680 @item @code{whitelist} (default: @code{'()})
25681 If not empty, only allow access to this list of directories.
25683 @item @code{extra-options} (default: @code{'()})
25684 Extra options will be passed to @command{git daemon}, please run
25685 @command{man git-daemon} for more information.
25690 The @code{git://} protocol lacks authentication. When you pull from a
25691 repository fetched via @code{git://}, you don't know whether the data you
25692 receive was modified or is even coming from the specified host, and your
25693 connection is subject to eavesdropping. It's better to use an authenticated
25694 and encrypted transport, such as @code{https}. Although Git allows you
25695 to serve repositories using unsophisticated file-based web servers,
25696 there is a faster protocol implemented by the @code{git-http-backend}
25697 program. This program is the back-end of a proper Git web service. It
25698 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
25699 on running the necessary @code{fcgiwrap} daemon.
25701 Guix has a separate configuration data type for serving Git repositories
25704 @deftp {Data Type} git-http-configuration
25705 Data type representing the configuration for a future
25706 @code{git-http-service-type}; can currently be used to configure Nginx
25707 trough @code{git-http-nginx-location-configuration}.
25710 @item @code{package} (default: @var{git})
25711 Package object of the Git distributed version control system.
25713 @item @code{git-root} (default: @file{/srv/git})
25714 Directory containing the Git repositories to expose to the world.
25716 @item @code{export-all?} (default: @code{#f})
25717 Whether to expose access for all Git repositories in @var{git-root},
25718 even if they do not have the @file{git-daemon-export-ok} file.
25720 @item @code{uri-path} (default: @samp{/git/})
25721 Path prefix for Git access. With the default @samp{/git/} prefix, this
25722 will map @indicateurl{http://@var{server}/git/@var{repo}.git} to
25723 @file{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
25724 with this prefix are not passed on to this Git instance.
25726 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
25727 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
25732 There is no @code{git-http-service-type}, currently; instead you can
25733 create an @code{nginx-location-configuration} from a
25734 @code{git-http-configuration} and then add that location to a web
25737 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
25738 [config=(git-http-configuration)]
25739 Compute an @code{nginx-location-configuration} that corresponds to the
25740 given Git http configuration. An example nginx service definition to
25741 serve the default @file{/srv/git} over HTTPS might be:
25744 (service nginx-service-type
25745 (nginx-configuration
25748 (nginx-server-configuration
25749 (listen '("443 ssl"))
25750 (server-name "git.my-host.org")
25752 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
25753 (ssl-certificate-key
25754 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
25757 (git-http-nginx-location-configuration
25758 (git-http-configuration (uri-path "/"))))))))))
25761 This example assumes that you are using Let's Encrypt to get your TLS
25762 certificate. @xref{Certificate Services}. The default @code{certbot}
25763 service will redirect all HTTP traffic on @code{git.my-host.org} to
25764 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
25765 system services. @xref{Web Services}.
25768 @subsubheading Cgit Service
25770 @cindex Cgit service
25771 @cindex Git, web interface
25772 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
25773 repositories written in C.
25775 The following example will configure the service with default values.
25776 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
25779 (service cgit-service-type)
25782 The @code{file-object} type designates either a file-like object
25783 (@pxref{G-Expressions, file-like objects}) or a string.
25785 @c %start of fragment
25787 Available @code{cgit-configuration} fields are:
25789 @deftypevr {@code{cgit-configuration} parameter} package package
25794 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
25795 NGINX configuration.
25799 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
25800 Specifies a command which will be invoked to format the content of about
25801 pages (both top-level and for each repository).
25803 Defaults to @samp{""}.
25807 @deftypevr {@code{cgit-configuration} parameter} string agefile
25808 Specifies a path, relative to each repository path, which can be used to
25809 specify the date and time of the youngest commit in the repository.
25811 Defaults to @samp{""}.
25815 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
25816 Specifies a command that will be invoked for authenticating repository
25819 Defaults to @samp{""}.
25823 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
25824 Flag which, when set to @samp{age}, enables date ordering in the branch
25825 ref list, and when set @samp{name} enables ordering by branch name.
25827 Defaults to @samp{"name"}.
25831 @deftypevr {@code{cgit-configuration} parameter} string cache-root
25832 Path used to store the cgit cache entries.
25834 Defaults to @samp{"/var/cache/cgit"}.
25838 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
25839 Number which specifies the time-to-live, in minutes, for the cached
25840 version of repository pages accessed with a fixed SHA1.
25842 Defaults to @samp{-1}.
25846 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
25847 Number which specifies the time-to-live, in minutes, for the cached
25848 version of repository pages accessed without a fixed SHA1.
25850 Defaults to @samp{5}.
25854 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
25855 Number which specifies the time-to-live, in minutes, for the cached
25856 version of the repository summary page.
25858 Defaults to @samp{5}.
25862 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
25863 Number which specifies the time-to-live, in minutes, for the cached
25864 version of the repository index page.
25866 Defaults to @samp{5}.
25870 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
25871 Number which specifies the time-to-live, in minutes, for the result of
25872 scanning a path for Git repositories.
25874 Defaults to @samp{15}.
25878 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
25879 Number which specifies the time-to-live, in minutes, for the cached
25880 version of the repository about page.
25882 Defaults to @samp{15}.
25886 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
25887 Number which specifies the time-to-live, in minutes, for the cached
25888 version of snapshots.
25890 Defaults to @samp{5}.
25894 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
25895 The maximum number of entries in the cgit cache. When set to @samp{0},
25896 caching is disabled.
25898 Defaults to @samp{0}.
25902 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
25903 Sort items in the repo list case sensitively.
25905 Defaults to @samp{#t}.
25909 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
25910 List of common prefixes which, when combined with a repository URL,
25911 generates valid clone URLs for the repository.
25913 Defaults to @samp{()}.
25917 @deftypevr {@code{cgit-configuration} parameter} list clone-url
25918 List of @code{clone-url} templates.
25920 Defaults to @samp{()}.
25924 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
25925 Command which will be invoked to format commit messages.
25927 Defaults to @samp{""}.
25931 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
25932 Flag which, when set to @samp{date}, enables strict date ordering in the
25933 commit log, and when set to @samp{topo} enables strict topological
25936 Defaults to @samp{"git log"}.
25940 @deftypevr {@code{cgit-configuration} parameter} file-object css
25941 URL which specifies the css document to include in all cgit pages.
25943 Defaults to @samp{"/share/cgit/cgit.css"}.
25947 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
25948 Specifies a command which will be invoked to format names and email
25949 address of committers, authors, and taggers, as represented in various
25950 places throughout the cgit interface.
25952 Defaults to @samp{""}.
25956 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
25957 Flag which, when set to @samp{#t}, will make cgit generate a HTML
25958 fragment suitable for embedding in other HTML pages.
25960 Defaults to @samp{#f}.
25964 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
25965 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
25966 commit history graph to the left of the commit messages in the
25967 repository log page.
25969 Defaults to @samp{#f}.
25973 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
25974 Flag which, when set to @samp{#t}, allows all filter settings to be
25975 overridden in repository-specific cgitrc files.
25977 Defaults to @samp{#f}.
25981 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
25982 Flag which, when set to @samp{#t}, allows users to follow a file in the
25985 Defaults to @samp{#f}.
25989 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
25990 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
25993 Defaults to @samp{#t}.
25997 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
25998 Flag which, when set to @samp{#t}, will make cgit generate extra links
25999 "summary", "commit", "tree" for each repo in the repository index.
26001 Defaults to @samp{#f}.
26005 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
26006 Flag which, when set to @samp{#t}, will make cgit display the owner of
26007 each repo in the repository index.
26009 Defaults to @samp{#t}.
26013 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
26014 Flag which, when set to @samp{#t}, will make cgit print the number of
26015 modified files for each commit on the repository log page.
26017 Defaults to @samp{#f}.
26021 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
26022 Flag which, when set to @samp{#t}, will make cgit print the number of
26023 added and removed lines for each commit on the repository log page.
26025 Defaults to @samp{#f}.
26029 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
26030 Flag which, when set to @code{#t}, will make cgit display remote
26031 branches in the summary and refs views.
26033 Defaults to @samp{#f}.
26037 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
26038 Flag which, when set to @code{1}, will make cgit use the subject of the
26039 parent commit as link text when generating links to parent commits in
26042 Defaults to @samp{#f}.
26046 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
26047 Flag which, when set to @samp{#t}, will make cgit use the subject of the
26048 parent commit as link text when generating links to parent commits in
26051 Defaults to @samp{#f}.
26055 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
26056 Flag which, when set to @samp{#t}, will make cgit generate linenumber
26057 links for plaintext blobs printed in the tree view.
26059 Defaults to @samp{#t}.
26063 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
26064 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
26065 set any repo specific settings.
26067 Defaults to @samp{#f}.
26071 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
26072 URL used as link to a shortcut icon for cgit.
26074 Defaults to @samp{"/favicon.ico"}.
26078 @deftypevr {@code{cgit-configuration} parameter} string footer
26079 The content of the file specified with this option will be included
26080 verbatim at the bottom of all pages (i.e.@: it replaces the standard
26081 "generated by..."@: message).
26083 Defaults to @samp{""}.
26087 @deftypevr {@code{cgit-configuration} parameter} string head-include
26088 The content of the file specified with this option will be included
26089 verbatim in the HTML HEAD section on all pages.
26091 Defaults to @samp{""}.
26095 @deftypevr {@code{cgit-configuration} parameter} string header
26096 The content of the file specified with this option will be included
26097 verbatim at the top of all pages.
26099 Defaults to @samp{""}.
26103 @deftypevr {@code{cgit-configuration} parameter} file-object include
26104 Name of a configfile to include before the rest of the current config-
26107 Defaults to @samp{""}.
26111 @deftypevr {@code{cgit-configuration} parameter} string index-header
26112 The content of the file specified with this option will be included
26113 verbatim above the repository index.
26115 Defaults to @samp{""}.
26119 @deftypevr {@code{cgit-configuration} parameter} string index-info
26120 The content of the file specified with this option will be included
26121 verbatim below the heading on the repository index page.
26123 Defaults to @samp{""}.
26127 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
26128 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
26129 in the servers timezone.
26131 Defaults to @samp{#f}.
26135 @deftypevr {@code{cgit-configuration} parameter} file-object logo
26136 URL which specifies the source of an image which will be used as a logo
26139 Defaults to @samp{"/share/cgit/cgit.png"}.
26143 @deftypevr {@code{cgit-configuration} parameter} string logo-link
26144 URL loaded when clicking on the cgit logo image.
26146 Defaults to @samp{""}.
26150 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
26151 Command which will be invoked to format the Owner column of the main
26154 Defaults to @samp{""}.
26158 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
26159 Number of items to display in atom feeds view.
26161 Defaults to @samp{10}.
26165 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
26166 Number of entries to list per page in "log" view.
26168 Defaults to @samp{50}.
26172 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
26173 Number of commit message characters to display in "log" view.
26175 Defaults to @samp{80}.
26179 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
26180 Specifies the number of entries to list per page on the repository index
26183 Defaults to @samp{50}.
26187 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
26188 Specifies the maximum number of repo description characters to display
26189 on the repository index page.
26191 Defaults to @samp{80}.
26195 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
26196 Specifies the maximum size of a blob to display HTML for in KBytes.
26198 Defaults to @samp{0}.
26202 @deftypevr {@code{cgit-configuration} parameter} string max-stats
26203 Maximum statistics period. Valid values are @samp{week},@samp{month},
26204 @samp{quarter} and @samp{year}.
26206 Defaults to @samp{""}.
26210 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
26211 Mimetype for the specified filename extension.
26213 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
26214 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
26215 "image/png") (svg "image/svg+xml"))}.
26219 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
26220 Specifies the file to use for automatic mimetype lookup.
26222 Defaults to @samp{""}.
26226 @deftypevr {@code{cgit-configuration} parameter} string module-link
26227 Text which will be used as the formatstring for a hyperlink when a
26228 submodule is printed in a directory listing.
26230 Defaults to @samp{""}.
26234 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
26235 If set to the value @samp{#t} caching will be disabled.
26237 Defaults to @samp{#f}.
26241 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
26242 If set to @samp{#t} showing full author email addresses will be
26245 Defaults to @samp{#f}.
26249 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
26250 Flag which, when set to @samp{#t}, will make cgit omit the standard
26251 header on all pages.
26253 Defaults to @samp{#f}.
26257 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
26258 A list of subdirectories inside of @code{repository-directory}, relative
26259 to it, that should loaded as Git repositories. An empty list means that
26260 all subdirectories will be loaded.
26262 Defaults to @samp{()}.
26266 @deftypevr {@code{cgit-configuration} parameter} file-object readme
26267 Text which will be used as default value for @code{cgit-repo-readme}.
26269 Defaults to @samp{""}.
26273 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
26274 If set to @code{#t} and @code{repository-directory} is enabled, if any
26275 repositories are found with a suffix of @code{.git}, this suffix will be
26276 removed for the URL and name.
26278 Defaults to @samp{#f}.
26282 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
26283 Maximum number of files to consider when detecting renames.
26285 Defaults to @samp{-1}.
26289 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
26290 The way in which repositories in each section are sorted.
26292 Defaults to @samp{""}.
26296 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
26297 Text used as content for the @code{robots} meta-tag.
26299 Defaults to @samp{("noindex" "nofollow")}.
26303 @deftypevr {@code{cgit-configuration} parameter} string root-desc
26304 Text printed below the heading on the repository index page.
26306 Defaults to @samp{"a fast webinterface for the git dscm"}.
26310 @deftypevr {@code{cgit-configuration} parameter} string root-readme
26311 The content of the file specified with this option will be included
26312 verbatim below the ``about'' link on the repository index page.
26314 Defaults to @samp{""}.
26318 @deftypevr {@code{cgit-configuration} parameter} string root-title
26319 Text printed as heading on the repository index page.
26321 Defaults to @samp{""}.
26325 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
26326 If set to @samp{#t} and repository-directory is enabled,
26327 repository-directory will recurse into directories whose name starts
26328 with a period. Otherwise, repository-directory will stay away from such
26329 directories, considered as ``hidden''. Note that this does not apply to
26330 the @file{.git} directory in non-bare repos.
26332 Defaults to @samp{#f}.
26336 @deftypevr {@code{cgit-configuration} parameter} list snapshots
26337 Text which specifies the default set of snapshot formats that cgit
26338 generates links for.
26340 Defaults to @samp{()}.
26344 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
26345 Name of the directory to scan for repositories (represents
26348 Defaults to @samp{"/srv/git"}.
26352 @deftypevr {@code{cgit-configuration} parameter} string section
26353 The name of the current repository section - all repositories defined
26354 after this option will inherit the current section name.
26356 Defaults to @samp{""}.
26360 @deftypevr {@code{cgit-configuration} parameter} string section-sort
26361 Flag which, when set to @samp{1}, will sort the sections on the
26362 repository listing by name.
26364 Defaults to @samp{""}.
26368 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
26369 A number which, if defined prior to repository-directory, specifies how
26370 many path elements from each repo path to use as a default section name.
26372 Defaults to @samp{0}.
26376 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
26377 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
26380 Defaults to @samp{#f}.
26384 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
26385 Specifies a command which will be invoked to format plaintext blobs in
26388 Defaults to @samp{""}.
26392 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
26393 Specifies the number of branches to display in the repository ``summary''
26396 Defaults to @samp{10}.
26400 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
26401 Specifies the number of log entries to display in the repository
26404 Defaults to @samp{10}.
26408 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
26409 Specifies the number of tags to display in the repository ``summary''
26412 Defaults to @samp{10}.
26416 @deftypevr {@code{cgit-configuration} parameter} string strict-export
26417 Filename which, if specified, needs to be present within the repository
26418 for cgit to allow access to that repository.
26420 Defaults to @samp{""}.
26424 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
26425 URL which, if specified, will be used as root for all cgit links.
26427 Defaults to @samp{"/"}.
26431 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
26432 A list of @dfn{cgit-repo} records to use with config.
26434 Defaults to @samp{()}.
26436 Available @code{repository-cgit-configuration} fields are:
26438 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
26439 A mask of snapshot formats for this repo that cgit generates links for,
26440 restricted by the global @code{snapshots} setting.
26442 Defaults to @samp{()}.
26446 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
26447 Override the default @code{source-filter}.
26449 Defaults to @samp{""}.
26453 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
26454 The relative URL used to access the repository.
26456 Defaults to @samp{""}.
26460 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
26461 Override the default @code{about-filter}.
26463 Defaults to @samp{""}.
26467 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
26468 Flag which, when set to @samp{age}, enables date ordering in the branch
26469 ref list, and when set to @samp{name} enables ordering by branch name.
26471 Defaults to @samp{""}.
26475 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
26476 A list of URLs which can be used to clone repo.
26478 Defaults to @samp{()}.
26482 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
26483 Override the default @code{commit-filter}.
26485 Defaults to @samp{""}.
26489 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
26490 Flag which, when set to @samp{date}, enables strict date ordering in the
26491 commit log, and when set to @samp{topo} enables strict topological
26494 Defaults to @samp{""}.
26498 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
26499 The name of the default branch for this repository. If no such branch
26500 exists in the repository, the first branch name (when sorted) is used as
26501 default instead. By default branch pointed to by HEAD, or ``master'' if
26502 there is no suitable HEAD.
26504 Defaults to @samp{""}.
26508 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
26509 The value to show as repository description.
26511 Defaults to @samp{""}.
26515 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
26516 The value to show as repository homepage.
26518 Defaults to @samp{""}.
26522 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
26523 Override the default @code{email-filter}.
26525 Defaults to @samp{""}.
26529 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
26530 A flag which can be used to disable the global setting
26531 @code{enable-commit-graph?}.
26533 Defaults to @samp{disabled}.
26537 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
26538 A flag which can be used to disable the global setting
26539 @code{enable-log-filecount?}.
26541 Defaults to @samp{disabled}.
26545 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
26546 A flag which can be used to disable the global setting
26547 @code{enable-log-linecount?}.
26549 Defaults to @samp{disabled}.
26553 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
26554 Flag which, when set to @code{#t}, will make cgit display remote
26555 branches in the summary and refs views.
26557 Defaults to @samp{disabled}.
26561 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
26562 A flag which can be used to override the global setting
26563 @code{enable-subject-links?}.
26565 Defaults to @samp{disabled}.
26569 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
26570 A flag which can be used to override the global setting
26571 @code{enable-html-serving?}.
26573 Defaults to @samp{disabled}.
26577 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
26578 Flag which, when set to @code{#t}, hides the repository from the
26581 Defaults to @samp{#f}.
26585 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
26586 Flag which, when set to @samp{#t}, ignores the repository.
26588 Defaults to @samp{#f}.
26592 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
26593 URL which specifies the source of an image which will be used as a logo
26594 on this repo’s pages.
26596 Defaults to @samp{""}.
26600 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
26601 URL loaded when clicking on the cgit logo image.
26603 Defaults to @samp{""}.
26607 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
26608 Override the default @code{owner-filter}.
26610 Defaults to @samp{""}.
26614 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
26615 Text which will be used as the formatstring for a hyperlink when a
26616 submodule is printed in a directory listing. The arguments for the
26617 formatstring are the path and SHA1 of the submodule commit.
26619 Defaults to @samp{""}.
26623 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
26624 Text which will be used as the formatstring for a hyperlink when a
26625 submodule with the specified subdirectory path is printed in a directory
26628 Defaults to @samp{()}.
26632 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
26633 Override the default maximum statistics period.
26635 Defaults to @samp{""}.
26639 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
26640 The value to show as repository name.
26642 Defaults to @samp{""}.
26646 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
26647 A value used to identify the owner of the repository.
26649 Defaults to @samp{""}.
26653 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
26654 An absolute path to the repository directory.
26656 Defaults to @samp{""}.
26660 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
26661 A path (relative to repo) which specifies a file to include verbatim as
26662 the ``About'' page for this repo.
26664 Defaults to @samp{""}.
26668 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
26669 The name of the current repository section - all repositories defined
26670 after this option will inherit the current section name.
26672 Defaults to @samp{""}.
26676 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
26677 Extra options will be appended to cgitrc file.
26679 Defaults to @samp{()}.
26685 @deftypevr {@code{cgit-configuration} parameter} list extra-options
26686 Extra options will be appended to cgitrc file.
26688 Defaults to @samp{()}.
26693 @c %end of fragment
26695 However, it could be that you just want to get a @code{cgitrc} up and
26696 running. In that case, you can pass an @code{opaque-cgit-configuration}
26697 as a record to @code{cgit-service-type}. As its name indicates, an
26698 opaque configuration does not have easy reflective capabilities.
26700 Available @code{opaque-cgit-configuration} fields are:
26702 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
26706 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
26707 The contents of the @code{cgitrc}, as a string.
26710 For example, if your @code{cgitrc} is just the empty string, you
26711 could instantiate a cgit service like this:
26714 (service cgit-service-type
26715 (opaque-cgit-configuration
26719 @subsubheading Gitolite Service
26721 @cindex Gitolite service
26722 @cindex Git, hosting
26723 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
26724 repositories on a central server.
26726 Gitolite can handle multiple repositories and users, and supports flexible
26727 configuration of the permissions for the users on the repositories.
26729 The following example will configure Gitolite using the default @code{git}
26730 user, and the provided SSH public key.
26733 (service gitolite-service-type
26734 (gitolite-configuration
26735 (admin-pubkey (plain-file
26737 "ssh-rsa AAAA... guix@@example.com"))))
26740 Gitolite is configured through a special admin repository which you can clone,
26741 for example, if you setup Gitolite on @code{example.com}, you would run the
26742 following command to clone the admin repository.
26745 git clone git@@example.com:gitolite-admin
26748 When the Gitolite service is activated, the provided @code{admin-pubkey} will
26749 be inserted in to the @file{keydir} directory in the gitolite-admin
26750 repository. If this results in a change in the repository, it will be
26751 committed using the message ``gitolite setup by GNU Guix''.
26753 @deftp {Data Type} gitolite-configuration
26754 Data type representing the configuration for @code{gitolite-service-type}.
26757 @item @code{package} (default: @var{gitolite})
26758 Gitolite package to use.
26760 @item @code{user} (default: @var{git})
26761 User to use for Gitolite. This will be user that you use when accessing
26764 @item @code{group} (default: @var{git})
26765 Group to use for Gitolite.
26767 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
26768 Directory in which to store the Gitolite configuration and repositories.
26770 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
26771 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
26772 representing the configuration for Gitolite.
26774 @item @code{admin-pubkey} (default: @var{#f})
26775 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
26776 setup Gitolite. This will be inserted in to the @file{keydir} directory
26777 within the gitolite-admin repository.
26779 To specify the SSH key as a string, use the @code{plain-file} function.
26782 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
26788 @deftp {Data Type} gitolite-rc-file
26789 Data type representing the Gitolite RC file.
26792 @item @code{umask} (default: @code{#o0077})
26793 This controls the permissions Gitolite sets on the repositories and their
26796 A value like @code{#o0027} will give read access to the group used by Gitolite
26797 (by default: @code{git}). This is necessary when using Gitolite with software
26798 like cgit or gitweb.
26800 @item @code{git-config-keys} (default: @code{""})
26801 Gitolite allows you to set git config values using the @samp{config} keyword. This
26802 setting allows control over the config keys to accept.
26804 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
26805 Set the role names allowed to be used by users running the perms command.
26807 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
26808 This setting controls the commands and features to enable within Gitolite.
26814 @node Game Services
26815 @subsection Game Services
26817 @subsubheading The Battle for Wesnoth Service
26819 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
26820 based tactical strategy game, with several single player campaigns, and
26821 multiplayer games (both networked and local).
26823 @defvar {Scheme Variable} wesnothd-service-type
26824 Service type for the wesnothd service. Its value must be a
26825 @code{wesnothd-configuration} object. To run wesnothd in the default
26826 configuration, instantiate it as:
26829 (service wesnothd-service-type)
26833 @deftp {Data Type} wesnothd-configuration
26834 Data type representing the configuration of @command{wesnothd}.
26837 @item @code{package} (default: @code{wesnoth-server})
26838 The wesnoth server package to use.
26840 @item @code{port} (default: @code{15000})
26841 The port to bind the server to.
26846 @node PAM Mount Service
26847 @subsection PAM Mount Service
26850 The @code{(gnu services pam-mount)} module provides a service allowing
26851 users to mount volumes when they log in. It should be able to mount any
26852 volume format supported by the system.
26854 @defvar {Scheme Variable} pam-mount-service-type
26855 Service type for PAM Mount support.
26858 @deftp {Data Type} pam-mount-configuration
26859 Data type representing the configuration of PAM Mount.
26861 It takes the following parameters:
26865 The configuration rules that will be used to generate
26866 @file{/etc/security/pam_mount.conf.xml}.
26868 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
26869 Guile Reference Manual}), and the the default ones don't mount anything
26870 for anyone at login:
26873 `((debug (@@ (enable "0")))
26874 (mntoptions (@@ (allow ,(string-join
26875 '("nosuid" "nodev" "loop"
26876 "encryption" "fsck" "nonempty"
26877 "allow_root" "allow_other")
26879 (mntoptions (@@ (require "nosuid,nodev")))
26880 (logout (@@ (wait "0")
26884 (mkmountpoint (@@ (enable "1")
26888 Some @code{volume} elements must be added to automatically mount volumes
26889 at login. Here's an example allowing the user @code{alice} to mount her
26890 encrypted @env{HOME} directory and allowing the user @code{bob} to mount
26891 the partition where he stores his data:
26894 (define pam-mount-rules
26895 `((debug (@@ (enable "0")))
26896 (volume (@@ (user "alice")
26899 (mountpoint "/home/alice")))
26900 (volume (@@ (user "bob")
26903 (mountpoint "/home/bob/data")
26904 (options "defaults,autodefrag,compress")))
26905 (mntoptions (@@ (allow ,(string-join
26906 '("nosuid" "nodev" "loop"
26907 "encryption" "fsck" "nonempty"
26908 "allow_root" "allow_other")
26910 (mntoptions (@@ (require "nosuid,nodev")))
26911 (logout (@@ (wait "0")
26915 (mkmountpoint (@@ (enable "1")
26916 (remove "true")))))
26918 (service pam-mount-service-type
26919 (pam-mount-configuration
26920 (rules pam-mount-rules)))
26923 The complete list of possible options can be found in the man page for
26924 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
26929 @node Guix Services
26930 @subsection Guix Services
26932 @subsubheading Guix Data Service
26933 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
26934 and provides data about GNU Guix. This includes information about
26935 packages, derivations and lint warnings.
26937 The data is stored in a PostgreSQL database, and available through a web
26940 @defvar {Scheme Variable} guix-data-service-type
26941 Service type for the Guix Data Service. Its value must be a
26942 @code{guix-data-service-configuration} object. The service optionally
26943 extends the getmail service, as the guix-commits mailing list is used to
26944 find out about changes in the Guix git repository.
26947 @deftp {Data Type} guix-data-service-configuration
26948 Data type representing the configuration of the Guix Data Service.
26951 @item @code{package} (default: @code{guix-data-service})
26952 The Guix Data Service package to use.
26954 @item @code{user} (default: @code{"guix-data-service"})
26955 The system user to run the service as.
26957 @item @code{group} (default: @code{"guix-data-service"})
26958 The system group to run the service as.
26960 @item @code{port} (default: @code{8765})
26961 The port to bind the web service to.
26963 @item @code{host} (default: @code{"127.0.0.1"})
26964 The host to bind the web service to.
26966 @item @code{getmail-idle-mailboxes} (default: @code{#f})
26967 If set, this is the list of mailboxes that the getmail service will be
26968 configured to listen to.
26970 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
26971 If set, this is the @code{getmail-retriever-configuration} object with
26972 which to configure getmail to fetch mail from the guix-commits mailing
26975 @item @code{extra-options} (default: @var{'()})
26976 Extra command line options for @code{guix-data-service}.
26978 @item @code{extra-process-jobs-options} (default: @var{'()})
26979 Extra command line options for @code{guix-data-service-process-jobs}.
26984 @node Linux Services
26985 @subsection Linux Services
26988 @cindex out of memory killer
26990 @cindex early out of memory daemon
26991 @subsubheading Early OOM Service
26993 @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
26994 Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
26995 space and provides a more responsive and configurable alternative to the
26996 in-kernel OOM killer. It is useful to prevent the system from becoming
26997 unresponsive when it runs out of memory.
26999 @deffn {Scheme Variable} earlyoom-service-type
27000 The service type for running @command{earlyoom}, the Early OOM daemon.
27001 Its value must be a @code{earlyoom-configuration} object, described
27002 below. The service can be instantiated in its default configuration
27006 (service earlyoom-service-type)
27010 @deftp {Data Type} earlyoom-configuration
27011 This is the configuration record for the @code{earlyoom-service-type}.
27014 @item @code{earlyoom} (default: @var{earlyoom})
27015 The Earlyoom package to use.
27017 @item @code{minimum-available-memory} (default: @code{10})
27018 The threshold for the minimum @emph{available} memory, in percentages.
27020 @item @code{minimum-free-swap} (default: @code{10})
27021 The threshold for the minimum free swap memory, in percentages.
27023 @item @code{prefer-regexp} (default: @code{#f})
27024 A regular expression (as a string) to match the names of the processes
27025 that should be preferably killed.
27027 @item @code{avoid-regexp} (default: @code{#f})
27028 A regular expression (as a string) to match the names of the processes
27029 that should @emph{not} be killed.
27031 @item @code{memory-report-interval} (default: @code{0})
27032 The interval in seconds at which a memory report is printed. It is
27033 disabled by default.
27035 @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
27036 A boolean indicating whether the positive adjustments set in
27037 @file{/proc/*/oom_score_adj}.
27039 @item @code{show-debug-messages?} (default: @code{#f})
27040 A boolean indicating whether debug messages should be printed. The logs
27041 are saved at @file{/var/log/earlyoom.log}.
27043 @item @code{send-notification-command} (default: @code{#f})
27044 This can be used to provide a custom command used for sending
27050 @cindex kernel module loader
27051 @subsubheading Kernel Module Loader Service
27053 The kernel module loader service allows one to load loadable kernel
27054 modules at boot. This is especially useful for modules that don't
27055 autoload and need to be manually loaded, as it's the case with
27058 @deffn {Scheme Variable} kernel-module-loader-service-type
27059 The service type for loading loadable kernel modules at boot with
27060 @command{modprobe}. Its value must be a list of strings representing
27061 module names. For example loading the drivers provided by
27062 @code{ddcci-driver-linux}, in debugging mode by passing some module
27063 parameters, can be done as follow:
27066 (use-modules (gnu) (gnu services))
27067 (use-package-modules linux)
27068 (use-service-modules linux)
27070 (define ddcci-config
27071 (plain-file "ddcci.conf"
27072 "options ddcci dyndbg delay=120"))
27076 (services (cons* (service kernel-module-loader-service-type
27077 '("ddcci" "ddcci_backlight"))
27078 (simple-service 'ddcci-config etc-service-type
27079 (list `("modprobe.d/ddcci.conf"
27082 (kernel-loadable-modules (list ddcci-driver-linux)))
27086 @node Hurd Services
27087 @subsection Hurd Services
27089 @defvr {Scheme Variable} hurd-console-service-type
27090 This service starts the fancy @code{VGA} console client on the Hurd.
27092 The service's value is a @code{hurd-console-configuration} record.
27095 @deftp {Data Type} hurd-console-configuration
27096 This is the data type representing the configuration for the
27097 hurd-console-service.
27100 @item @code{hurd} (default: @var{hurd})
27101 The Hurd package to use.
27105 @defvr {Scheme Variable} hurd-getty-service-type
27106 This service starts a tty using the Hurd @code{getty} program.
27108 The service's value is a @code{hurd-getty-configuration} record.
27111 @deftp {Data Type} hurd-getty-configuration
27112 This is the data type representing the configuration for the
27113 hurd-getty-service.
27116 @item @code{hurd} (default: @var{hurd})
27117 The Hurd package to use.
27120 The name of the console this Getty runs on---e.g., @code{"tty1"}.
27122 @item @code{baud-rate} (default: @code{38400})
27123 An integer specifying the baud rate of the tty.
27128 @node Miscellaneous Services
27129 @subsection Miscellaneous Services
27131 @cindex fingerprint
27132 @subsubheading Fingerprint Service
27134 The @code{(gnu services authentication)} module provides a DBus service to
27135 read and identify fingerprints via a fingerprint sensor.
27137 @defvr {Scheme Variable} fprintd-service-type
27138 The service type for @command{fprintd}, which provides the fingerprint
27139 reading capability.
27142 (service fprintd-service-type)
27147 @subsubheading System Control Service
27149 The @code{(gnu services sysctl)} provides a service to configure kernel
27150 parameters at boot.
27152 @defvr {Scheme Variable} sysctl-service-type
27153 The service type for @command{sysctl}, which modifies kernel parameters
27154 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
27158 (service sysctl-service-type
27159 (sysctl-configuration
27160 (settings '(("net.ipv4.ip_forward" . "1")))))
27164 @deftp {Data Type} sysctl-configuration
27165 The data type representing the configuration of @command{sysctl}.
27168 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
27169 The @command{sysctl} executable to use.
27171 @item @code{settings} (default: @code{'()})
27172 An association list specifies kernel parameters and their values.
27177 @subsubheading PC/SC Smart Card Daemon Service
27179 The @code{(gnu services security-token)} module provides the following service
27180 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
27181 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
27182 manager that coordinates communications with smart card readers, smart cards
27183 and cryptographic tokens that are connected to the system.
27185 @defvr {Scheme Variable} pcscd-service-type
27186 Service type for the @command{pcscd} service. Its value must be a
27187 @code{pcscd-configuration} object. To run pcscd in the default
27188 configuration, instantiate it as:
27191 (service pcscd-service-type)
27195 @deftp {Data Type} pcscd-configuration
27196 The data type representing the configuration of @command{pcscd}.
27199 @item @code{pcsc-lite} (default: @code{pcsc-lite})
27200 The pcsc-lite package that provides pcscd.
27201 @item @code{usb-drivers} (default: @code{(list ccid)})
27202 List of packages that provide USB drivers to pcscd. Drivers are expected to be
27203 under @file{pcsc/drivers} in the store directory of the package.
27208 @subsubheading Lirc Service
27210 The @code{(gnu services lirc)} module provides the following service.
27212 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
27213 [#:device #f] [#:driver #f] [#:config-file #f] @
27214 [#:extra-options '()]
27215 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
27216 decodes infrared signals from remote controls.
27218 Optionally, @var{device}, @var{driver} and @var{config-file}
27219 (configuration file name) may be specified. See @command{lircd} manual
27222 Finally, @var{extra-options} is a list of additional command-line options
27223 passed to @command{lircd}.
27227 @subsubheading Spice Service
27229 The @code{(gnu services spice)} module provides the following service.
27231 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
27232 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
27233 that enables sharing the clipboard with a vm and setting the guest display
27234 resolution when the graphical console window resizes.
27237 @cindex inputattach
27238 @subsubheading inputattach Service
27240 @cindex tablet input, for Xorg
27241 @cindex touchscreen input, for Xorg
27242 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
27243 use input devices such as Wacom tablets, touchscreens, or joysticks with the
27244 Xorg display server.
27246 @deffn {Scheme Variable} inputattach-service-type
27247 Type of a service that runs @command{inputattach} on a device and
27248 dispatches events from it.
27251 @deftp {Data Type} inputattach-configuration
27253 @item @code{device-type} (default: @code{"wacom"})
27254 The type of device to connect to. Run @command{inputattach --help}, from the
27255 @code{inputattach} package, to see the list of supported device types.
27257 @item @code{device} (default: @code{"/dev/ttyS0"})
27258 The device file to connect to the device.
27260 @item @code{baud-rate} (default: @code{#f})
27261 Baud rate to use for the serial connection.
27262 Should be a number or @code{#f}.
27264 @item @code{log-file} (default: @code{#f})
27265 If true, this must be the name of a file to log messages to.
27269 @subsubheading Dictionary Service
27271 The @code{(gnu services dict)} module provides the following service:
27273 @defvr {Scheme Variable} dicod-service-type
27274 This is the type of the service that runs the @command{dicod} daemon, an
27275 implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
27278 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
27279 Return a service that runs the @command{dicod} daemon, an implementation
27280 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
27282 The optional @var{config} argument specifies the configuration for
27283 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
27284 default it serves the GNU Collaborative International Dictionary of English.
27286 You can add @command{open localhost} to your @file{~/.dico} file to make
27287 @code{localhost} the default server for @command{dico} client
27288 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
27291 @deftp {Data Type} dicod-configuration
27292 Data type representing the configuration of dicod.
27295 @item @code{dico} (default: @var{dico})
27296 Package object of the GNU Dico dictionary server.
27298 @item @code{interfaces} (default: @var{'("localhost")})
27299 This is the list of IP addresses and ports and possibly socket file
27300 names to listen to (@pxref{Server Settings, @code{listen} directive,,
27301 dico, GNU Dico Manual}).
27303 @item @code{handlers} (default: @var{'()})
27304 List of @code{<dicod-handler>} objects denoting handlers (module instances).
27306 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
27307 List of @code{<dicod-database>} objects denoting dictionaries to be served.
27311 @deftp {Data Type} dicod-handler
27312 Data type representing a dictionary handler (module instance).
27316 Name of the handler (module instance).
27318 @item @code{module} (default: @var{#f})
27319 Name of the dicod module of the handler (instance). If it is @code{#f},
27320 the module has the same name as the handler.
27321 (@pxref{Modules,,, dico, GNU Dico Manual}).
27323 @item @code{options}
27324 List of strings or gexps representing the arguments for the module handler
27328 @deftp {Data Type} dicod-database
27329 Data type representing a dictionary database.
27333 Name of the database, will be used in DICT commands.
27335 @item @code{handler}
27336 Name of the dicod handler (module instance) used by this database
27337 (@pxref{Handlers,,, dico, GNU Dico Manual}).
27339 @item @code{complex?} (default: @var{#f})
27340 Whether the database configuration complex. The complex configuration
27341 will need a corresponding @code{<dicod-handler>} object, otherwise not.
27343 @item @code{options}
27344 List of strings or gexps representing the arguments for the database
27345 (@pxref{Databases,,, dico, GNU Dico Manual}).
27349 @defvr {Scheme Variable} %dicod-database:gcide
27350 A @code{<dicod-database>} object serving the GNU Collaborative International
27351 Dictionary of English using the @code{gcide} package.
27354 The following is an example @code{dicod-service} configuration.
27357 (dicod-service #:config
27358 (dicod-configuration
27359 (handlers (list (dicod-handler
27363 (list #~(string-append "dbdir=" #$wordnet))))))
27364 (databases (list (dicod-database
27367 (handler "wordnet")
27368 (options '("database=wn")))
27369 %dicod-database:gcide))))
27373 @subsubheading Docker Service
27375 The @code{(gnu services docker)} module provides the following services.
27377 @defvr {Scheme Variable} docker-service-type
27379 This is the type of the service that runs @url{https://www.docker.com,Docker},
27380 a daemon that can execute application bundles (sometimes referred to as
27381 ``containers'') in isolated environments.
27385 @deftp {Data Type} docker-configuration
27386 This is the data type representing the configuration of Docker and Containerd.
27390 @item @code{package} (default: @code{docker})
27391 The Docker package to use.
27393 @item @code{containerd} (default: @var{containerd})
27394 The Containerd package to use.
27396 @item @code{proxy} (default @var{docker-libnetwork-cmd-proxy})
27397 The Docker user-land networking proxy package to use.
27399 @item @code{enable-proxy?} (default @code{#f})
27400 Enable or disable the use of the Docker user-land networking proxy.
27402 @item @code{debug?} (default @code{#f})
27403 Enable or disable debug output.
27409 @subsubheading Auditd Service
27411 The @code{(gnu services auditd)} module provides the following service.
27413 @defvr {Scheme Variable} auditd-service-type
27415 This is the type of the service that runs
27416 @url{https://people.redhat.com/sgrubb/audit/,auditd},
27417 a daemon that tracks security-relevant information on your system.
27419 Examples of things that can be tracked:
27429 Failed login attempts
27436 @command{auditctl} from the @code{audit} package can be used in order
27437 to add or remove events to be tracked (until the next reboot).
27438 In order to permanently track events, put the command line arguments
27439 of auditctl into @file{/etc/audit/audit.rules}.
27440 @command{aureport} from the @code{audit} package can be used in order
27441 to view a report of all recorded events.
27442 The audit daemon usually logs into the directory @file{/var/log/audit}.
27446 @deftp {Data Type} auditd-configuration
27447 This is the data type representing the configuration of auditd.
27451 @item @code{audit} (default: @code{audit})
27452 The audit package to use.
27457 @defvr {Scheme Variable} singularity-service-type
27458 This is the type of the service that allows you to run
27459 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
27460 create and run application bundles (aka. ``containers''). The value for this
27461 service is the Singularity package to use.
27463 The service does not install a daemon; instead, it installs helper programs as
27464 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
27465 @command{singularity run} and similar commands.
27469 @subsubheading R-Shiny service
27471 The @code{(gnu services science)} module provides the following service.
27473 @defvr {Scheme Variable} rshiny-service-type
27475 This is a type of service which is used to run a webapp created with
27476 @code{r-shiny}. This service sets the @code{R_LIBS_USER} environment
27477 variable and runs the provided script to call @code{runApp}.
27479 @deftp {Data Type} rshiny-configuration
27480 This is the data type representing the configuration of rshiny.
27484 @item @code{package} (default: @code{r-shiny})
27485 The package to use.
27487 @item @code{binary} (defaunlt @code{"rshiny"})
27488 The name of the binary or shell script located at @code{package/bin/} to
27489 run when the service is run.
27491 The common way to create this file is as follows:
27495 (let* ((out (assoc-ref %outputs "out"))
27496 (targetdir (string-append out "/share/" ,name))
27497 (app (string-append out "/bin/" ,name))
27498 (Rbin (string-append (assoc-ref %build-inputs "r-min")
27501 (mkdir-p (string-append out "/bin"))
27502 (call-with-output-file app
27508 runApp(launch.browser=0, port=4202)~%\n"
27518 @subsubheading Nix service
27520 The @code{(gnu services nix)} module provides the following service.
27522 @defvr {Scheme Variable} nix-service-type
27524 This is the type of the service that runs build daemon of the
27525 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
27529 (use-modules (gnu))
27530 (use-service-modules nix)
27531 (use-package-modules package-management)
27535 (packages (append (list nix)
27538 (services (append (list (service nix-service-type))
27542 After @command{guix system reconfigure} configure Nix for your user:
27545 @item Add a Nix channel and update it. See
27546 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
27548 @item Create a symlink to your profile and activate Nix profile:
27552 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
27553 $ source /run/current-system/profile/etc/profile.d/nix.sh
27558 @node Setuid Programs
27559 @section Setuid Programs
27561 @cindex setuid programs
27562 Some programs need to run with ``root'' privileges, even when they are
27563 launched by unprivileged users. A notorious example is the
27564 @command{passwd} program, which users can run to change their
27565 password, and which needs to access the @file{/etc/passwd} and
27566 @file{/etc/shadow} files---something normally restricted to root, for
27567 obvious security reasons. To address that, these executables are
27568 @dfn{setuid-root}, meaning that they always run with root privileges
27569 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
27570 for more info about the setuid mechanism).
27572 The store itself @emph{cannot} contain setuid programs: that would be a
27573 security issue since any user on the system can write derivations that
27574 populate the store (@pxref{The Store}). Thus, a different mechanism is
27575 used: instead of changing the setuid bit directly on files that are in
27576 the store, we let the system administrator @emph{declare} which programs
27577 should be setuid root.
27579 The @code{setuid-programs} field of an @code{operating-system}
27580 declaration contains a list of G-expressions denoting the names of
27581 programs to be setuid-root (@pxref{Using the Configuration System}).
27582 For instance, the @command{passwd} program, which is part of the Shadow
27583 package, can be designated by this G-expression (@pxref{G-Expressions}):
27586 #~(string-append #$shadow "/bin/passwd")
27589 A default set of setuid programs is defined by the
27590 @code{%setuid-programs} variable of the @code{(gnu system)} module.
27592 @defvr {Scheme Variable} %setuid-programs
27593 A list of G-expressions denoting common programs that are setuid-root.
27595 The list includes commands such as @command{passwd}, @command{ping},
27596 @command{su}, and @command{sudo}.
27599 Under the hood, the actual setuid programs are created in the
27600 @file{/run/setuid-programs} directory at system activation time. The
27601 files in this directory refer to the ``real'' binaries, which are in the
27604 @node X.509 Certificates
27605 @section X.509 Certificates
27607 @cindex HTTPS, certificates
27608 @cindex X.509 certificates
27610 Web servers available over HTTPS (that is, HTTP over the transport-layer
27611 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
27612 that the client can then use to @emph{authenticate} the server. To do
27613 that, clients verify that the server's certificate is signed by a
27614 so-called @dfn{certificate authority} (CA). But to verify the CA's
27615 signature, clients must have first acquired the CA's certificate.
27617 Web browsers such as GNU@tie{}IceCat include their own set of CA
27618 certificates, such that they are able to verify CA signatures
27621 However, most other programs that can talk HTTPS---@command{wget},
27622 @command{git}, @command{w3m}, etc.---need to be told where CA
27623 certificates can be found.
27625 @cindex @code{nss-certs}
27626 In Guix, this is done by adding a package that provides certificates
27627 to the @code{packages} field of the @code{operating-system} declaration
27628 (@pxref{operating-system Reference}). Guix includes one such package,
27629 @code{nss-certs}, which is a set of CA certificates provided as part of
27630 Mozilla's Network Security Services.
27632 Note that it is @emph{not} part of @code{%base-packages}, so you need to
27633 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
27634 most applications and libraries look for certificates by default, points
27635 to the certificates installed globally.
27637 Unprivileged users, including users of Guix on a foreign distro,
27638 can also install their own certificate package in
27639 their profile. A number of environment variables need to be defined so
27640 that applications and libraries know where to find them. Namely, the
27641 OpenSSL library honors the @env{SSL_CERT_DIR} and @env{SSL_CERT_FILE}
27642 variables. Some applications add their own environment variables; for
27643 instance, the Git version control system honors the certificate bundle
27644 pointed to by the @env{GIT_SSL_CAINFO} environment variable. Thus, you
27645 would typically run something like:
27648 guix install nss-certs
27649 export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
27650 export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
27651 export GIT_SSL_CAINFO="$SSL_CERT_FILE"
27654 As another example, R requires the @env{CURL_CA_BUNDLE} environment
27655 variable to point to a certificate bundle, so you would have to run
27656 something like this:
27659 guix install nss-certs
27660 export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
27663 For other applications you may want to look up the required environment
27664 variable in the relevant documentation.
27667 @node Name Service Switch
27668 @section Name Service Switch
27670 @cindex name service switch
27672 The @code{(gnu system nss)} module provides bindings to the
27673 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
27674 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
27675 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
27676 extended with new ``name'' lookup methods for system databases, which
27677 includes host names, service names, user accounts, and more (@pxref{Name
27678 Service Switch, System Databases and Name Service Switch,, libc, The GNU
27679 C Library Reference Manual}).
27681 The NSS configuration specifies, for each system database, which lookup
27682 method is to be used, and how the various methods are chained
27683 together---for instance, under which circumstances NSS should try the
27684 next method in the list. The NSS configuration is given in the
27685 @code{name-service-switch} field of @code{operating-system} declarations
27686 (@pxref{operating-system Reference, @code{name-service-switch}}).
27689 @cindex .local, host name lookup
27690 As an example, the declaration below configures the NSS to use the
27691 @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
27692 back-end}, which supports host name lookups over multicast DNS (mDNS)
27693 for host names ending in @code{.local}:
27696 (name-service-switch
27697 (hosts (list %files ;first, check /etc/hosts
27699 ;; If the above did not succeed, try
27700 ;; with 'mdns_minimal'.
27702 (name "mdns_minimal")
27704 ;; 'mdns_minimal' is authoritative for
27705 ;; '.local'. When it returns "not found",
27706 ;; no need to try the next methods.
27707 (reaction (lookup-specification
27708 (not-found => return))))
27710 ;; Then fall back to DNS.
27714 ;; Finally, try with the "full" 'mdns'.
27719 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
27720 contains this configuration, so you will not have to type it if all you
27721 want is to have @code{.local} host lookup working.
27723 Note that, in this case, in addition to setting the
27724 @code{name-service-switch} of the @code{operating-system} declaration,
27725 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
27726 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
27727 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
27728 to the name service cache daemon (@pxref{Base Services,
27729 @code{nscd-service}}).
27731 For convenience, the following variables provide typical NSS
27734 @defvr {Scheme Variable} %default-nss
27735 This is the default name service switch configuration, a
27736 @code{name-service-switch} object.
27739 @defvr {Scheme Variable} %mdns-host-lookup-nss
27740 This is the name service switch configuration with support for host name
27741 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
27744 The reference for name service switch configuration is given below. It
27745 is a direct mapping of the configuration file format of the C library , so
27746 please refer to the C library manual for more information (@pxref{NSS
27747 Configuration File,,, libc, The GNU C Library Reference Manual}).
27748 Compared to the configuration file format of libc NSS, it has the advantage
27749 not only of adding this warm parenthetic feel that we like, but also
27750 static checks: you will know about syntax errors and typos as soon as you
27751 run @command{guix system}.
27753 @deftp {Data Type} name-service-switch
27755 This is the data type representation the configuration of libc's name
27756 service switch (NSS). Each field below represents one of the supported
27773 The system databases handled by the NSS. Each of these fields must be a
27774 list of @code{<name-service>} objects (see below).
27778 @deftp {Data Type} name-service
27780 This is the data type representing an actual name service and the
27781 associated lookup action.
27785 A string denoting the name service (@pxref{Services in the NSS
27786 configuration,,, libc, The GNU C Library Reference Manual}).
27788 Note that name services listed here must be visible to nscd. This is
27789 achieved by passing the @code{#:name-services} argument to
27790 @code{nscd-service} the list of packages providing the needed name
27791 services (@pxref{Base Services, @code{nscd-service}}).
27794 An action specified using the @code{lookup-specification} macro
27795 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
27796 Reference Manual}). For example:
27799 (lookup-specification (unavailable => continue)
27800 (success => return))
27805 @node Initial RAM Disk
27806 @section Initial RAM Disk
27809 @cindex initial RAM disk
27810 For bootstrapping purposes, the Linux-Libre kernel is passed an
27811 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
27812 root file system as well as an initialization script. The latter is
27813 responsible for mounting the real root file system, and for loading any
27814 kernel modules that may be needed to achieve that.
27816 The @code{initrd-modules} field of an @code{operating-system}
27817 declaration allows you to specify Linux-libre kernel modules that must
27818 be available in the initrd. In particular, this is where you would list
27819 modules needed to actually drive the hard disk where your root partition
27820 is---although the default value of @code{initrd-modules} should cover
27821 most use cases. For example, assuming you need the @code{megaraid_sas}
27822 module in addition to the default modules to be able to access your root
27823 file system, you would write:
27828 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
27831 @defvr {Scheme Variable} %base-initrd-modules
27832 This is the list of kernel modules included in the initrd by default.
27835 Furthermore, if you need lower-level customization, the @code{initrd}
27836 field of an @code{operating-system} declaration allows
27837 you to specify which initrd you would like to use. The @code{(gnu
27838 system linux-initrd)} module provides three ways to build an initrd: the
27839 high-level @code{base-initrd} procedure and the low-level
27840 @code{raw-initrd} and @code{expression->initrd} procedures.
27842 The @code{base-initrd} procedure is intended to cover most common uses.
27843 For example, if you want to add a bunch of kernel modules to be loaded
27844 at boot time, you can define the @code{initrd} field of the operating
27845 system declaration like this:
27848 (initrd (lambda (file-systems . rest)
27849 ;; Create a standard initrd but set up networking
27850 ;; with the parameters QEMU expects by default.
27851 (apply base-initrd file-systems
27852 #:qemu-networking? #t
27856 The @code{base-initrd} procedure also handles common use cases that
27857 involves using the system as a QEMU guest, or as a ``live'' system with
27858 volatile root file system.
27860 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
27861 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
27862 such as trying to guess which kernel modules and packages should be included
27863 to the initrd. An example use of @code{raw-initrd} is when a user has
27864 a custom Linux kernel configuration and default kernel modules included by
27865 @code{base-initrd} are not available.
27867 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
27868 honors several options passed on the Linux kernel command line
27869 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
27870 @code{-append} option of QEMU), notably:
27873 @item --load=@var{boot}
27874 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
27875 program, once it has mounted the root file system.
27877 Guix uses this option to yield control to a boot program that runs the
27878 service activation programs and then spawns the GNU@tie{}Shepherd, the
27879 initialization system.
27881 @item --root=@var{root}
27882 Mount @var{root} as the root file system. @var{root} can be a device
27883 name like @code{/dev/sda1}, a file system label, or a file system UUID.
27884 When unspecified, the device name from the root file system of the
27885 operating system declaration is used.
27887 @item --system=@var{system}
27888 Have @file{/run/booted-system} and @file{/run/current-system} point to
27891 @item modprobe.blacklist=@var{modules}@dots{}
27892 @cindex module, black-listing
27893 @cindex black list, of kernel modules
27894 Instruct the initial RAM disk as well as the @command{modprobe} command
27895 (from the kmod package) to refuse to load @var{modules}. @var{modules}
27896 must be a comma-separated list of module names---e.g.,
27897 @code{usbkbd,9pnet}.
27900 Start a read-eval-print loop (REPL) from the initial RAM disk before it
27901 tries to load kernel modules and to mount the root file system. Our
27902 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
27903 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
27904 Manual}, for more information on Guile's REPL.
27908 Now that you know all the features that initial RAM disks produced by
27909 @code{base-initrd} and @code{raw-initrd} provide,
27910 here is how to use it and customize it further.
27913 @cindex initial RAM disk
27914 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
27915 [#:linux-modules '()] [#:mapped-devices '()] @
27916 [#:keyboard-layout #f] @
27917 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
27918 Return a derivation that builds a raw initrd. @var{file-systems} is
27919 a list of file systems to be mounted by the initrd, possibly in addition to
27920 the root file system specified on the kernel command line via @option{--root}.
27921 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
27922 @var{mapped-devices} is a list of device mappings to realize before
27923 @var{file-systems} are mounted (@pxref{Mapped Devices}).
27924 @var{helper-packages} is a list of packages to be copied in the initrd. It may
27925 include @code{e2fsck/static} or other packages needed by the initrd to check
27926 the root file system.
27928 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
27929 the desired console keyboard layout. This is done before @var{mapped-devices}
27930 are set up and before @var{file-systems} are mounted such that, should the
27931 user need to enter a passphrase or use the REPL, this happens using the
27932 intended keyboard layout.
27934 When @var{qemu-networking?} is true, set up networking with the standard QEMU
27935 parameters. When @var{virtio?} is true, load additional modules so that the
27936 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
27938 When @var{volatile-root?} is true, the root file system is writable but any changes
27942 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
27943 [#:mapped-devices '()] [#:keyboard-layout #f] @
27944 [#:qemu-networking? #f] [#:volatile-root? #f] @
27945 [#:linux-modules '()]
27946 Return as a file-like object a generic initrd, with kernel
27947 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
27948 mounted by the initrd, possibly in addition to the root file system specified
27949 on the kernel command line via @option{--root}. @var{mapped-devices} is a list of device
27950 mappings to realize before @var{file-systems} are mounted.
27952 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
27953 the desired console keyboard layout. This is done before @var{mapped-devices}
27954 are set up and before @var{file-systems} are mounted such that, should the
27955 user need to enter a passphrase or use the REPL, this happens using the
27956 intended keyboard layout.
27958 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
27960 The initrd is automatically populated with all the kernel modules necessary
27961 for @var{file-systems} and for the given options. Additional kernel
27962 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
27963 loaded at boot time in the order in which they appear.
27966 Needless to say, the initrds we produce and use embed a
27967 statically-linked Guile, and the initialization program is a Guile
27968 program. That gives a lot of flexibility. The
27969 @code{expression->initrd} procedure builds such an initrd, given the
27970 program to run in that initrd.
27972 @deffn {Scheme Procedure} expression->initrd @var{exp} @
27973 [#:guile %guile-3.0-static-stripped] [#:name "guile-initrd"]
27974 Return as a file-like object a Linux initrd (a gzipped cpio archive)
27975 containing @var{guile} and that evaluates @var{exp}, a G-expression,
27976 upon booting. All the derivations referenced by @var{exp} are
27977 automatically copied to the initrd.
27980 @node Bootloader Configuration
27981 @section Bootloader Configuration
27984 @cindex boot loader
27986 The operating system supports multiple bootloaders. The bootloader is
27987 configured using @code{bootloader-configuration} declaration. All the
27988 fields of this structure are bootloader agnostic except for one field,
27989 @code{bootloader} that indicates the bootloader to be configured and
27992 Some of the bootloaders do not honor every field of
27993 @code{bootloader-configuration}. For instance, the extlinux
27994 bootloader does not support themes and thus ignores the @code{theme}
27997 @deftp {Data Type} bootloader-configuration
27998 The type of a bootloader configuration declaration.
28002 @item @code{bootloader}
28003 @cindex EFI, bootloader
28004 @cindex UEFI, bootloader
28005 @cindex BIOS, bootloader
28006 The bootloader to use, as a @code{bootloader} object. For now
28007 @code{grub-bootloader}, @code{grub-efi-bootloader},
28008 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
28010 @vindex grub-efi-bootloader
28011 @code{grub-efi-bootloader} allows to boot on modern systems using the
28012 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
28013 use if the installation image contains a @file{/sys/firmware/efi} directory
28014 when you boot it on your system.
28016 @vindex grub-bootloader
28017 @code{grub-bootloader} allows you to boot in particular Intel-based machines
28018 in ``legacy'' BIOS mode.
28020 @cindex ARM, bootloaders
28021 @cindex AArch64, bootloaders
28022 Available bootloaders are described in @code{(gnu bootloader @dots{})}
28023 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
28024 of bootloaders for a wide range of ARM and AArch64 systems, using the
28025 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
28027 @item @code{target}
28028 This is a string denoting the target onto which to install the
28031 The interpretation depends on the bootloader in question. For
28032 @code{grub-bootloader}, for example, it should be a device name understood by
28033 the bootloader @command{installer} command, such as @code{/dev/sda} or
28034 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
28035 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
28036 system, usually @file{/boot/efi}.
28038 @item @code{menu-entries} (default: @code{()})
28039 A possibly empty list of @code{menu-entry} objects (see below), denoting
28040 entries to appear in the bootloader menu, in addition to the current
28041 system entry and the entry pointing to previous system generations.
28043 @item @code{default-entry} (default: @code{0})
28044 The index of the default boot menu entry. Index 0 is for the entry of the
28047 @item @code{timeout} (default: @code{5})
28048 The number of seconds to wait for keyboard input before booting. Set to
28049 0 to boot immediately, and to -1 to wait indefinitely.
28051 @cindex keyboard layout, for the bootloader
28052 @item @code{keyboard-layout} (default: @code{#f})
28053 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
28054 layout, usually US@tie{}English (``qwerty'').
28056 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
28060 This option is currently ignored by bootloaders other than @code{grub} and
28064 @item @code{theme} (default: @var{#f})
28065 The bootloader theme object describing the theme to use. If no theme
28066 is provided, some bootloaders might use a default theme, that's true
28069 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
28070 The output terminals used for the bootloader boot menu, as a list of
28071 symbols. GRUB accepts the values: @code{console}, @code{serial},
28072 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
28073 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
28074 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
28075 configuration,,, grub,GNU GRUB manual}).
28077 @item @code{terminal-inputs} (default: @code{'()})
28078 The input terminals used for the bootloader boot menu, as a list of
28079 symbols. For GRUB, the default is the native platform terminal as
28080 determined at run-time. GRUB accepts the values: @code{console},
28081 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
28082 @code{usb_keyboard}. This field corresponds to the GRUB variable
28083 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
28086 @item @code{serial-unit} (default: @code{#f})
28087 The serial unit used by the bootloader, as an integer from 0 to 3.
28088 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
28089 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
28091 @item @code{serial-speed} (default: @code{#f})
28092 The speed of the serial interface, as an integer. For GRUB, the
28093 default value is chosen at run-time; currently GRUB chooses
28094 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
28101 Should you want to list additional boot menu entries @i{via} the
28102 @code{menu-entries} field above, you will need to create them with the
28103 @code{menu-entry} form. For example, imagine you want to be able to
28104 boot another distro (hard to imagine!), you can define a menu entry
28109 (label "The Other Distro")
28110 (linux "/boot/old/vmlinux-2.6.32")
28111 (linux-arguments '("root=/dev/sda2"))
28112 (initrd "/boot/old/initrd"))
28117 @deftp {Data Type} menu-entry
28118 The type of an entry in the bootloader menu.
28123 The label to show in the menu---e.g., @code{"GNU"}.
28125 @item @code{linux} (default: @code{#f})
28126 The Linux kernel image to boot, for example:
28129 (file-append linux-libre "/bzImage")
28132 For GRUB, it is also possible to specify a device explicitly in the
28133 file path using GRUB's device naming convention (@pxref{Naming
28134 convention,,, grub, GNU GRUB manual}), for example:
28137 "(hd0,msdos1)/boot/vmlinuz"
28140 If the device is specified explicitly as above, then the @code{device}
28141 field is ignored entirely.
28143 @item @code{linux-arguments} (default: @code{()})
28144 The list of extra Linux kernel command-line arguments---e.g.,
28145 @code{("console=ttyS0")}.
28147 @item @code{initrd} (default: @code{#f})
28148 A G-Expression or string denoting the file name of the initial RAM disk
28149 to use (@pxref{G-Expressions}).
28151 @item @code{device} (default: @code{#f})
28152 The device where the kernel and initrd are to be found---i.e., for GRUB,
28153 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
28155 This may be a file system label (a string), a file system UUID (a
28156 bytevector, @pxref{File Systems}), or @code{#f}, in which case
28157 the bootloader will search the device containing the file specified by
28158 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
28159 must @emph{not} be an OS device name such as @file{/dev/sda1}.
28161 @item @code{multiboot-kernel} (default: @code{#f})
28162 The kernel to boot in Multiboot-mode (@pxref{multiboot,,, grub, GNU GRUB
28163 manual}). When this field is set, a Multiboot menu-entry is generated.
28167 (file-append mach "/boot/gnumach")
28170 @item @code{multiboot-arguments} (default: @code{()})
28171 The list of extra command-line arguments for the multiboot-kernel.
28173 @item @code{multiboot-modules} (default: @code{()})
28174 The list of commands for loading Multiboot modules. For example:
28177 (list (list (file-append hurd "/hurd/ext2fs.static") "ext2fs"
28179 (list (file-append libc "/lib/ld.so.1") "exec"
28189 @c FIXME: Write documentation once it's stable.
28190 For now only GRUB has theme support. GRUB themes are created using
28191 the @code{grub-theme} form, which is not fully documented yet.
28193 @deftp {Data Type} grub-theme
28194 Data type representing the configuration of the GRUB theme.
28197 @item @code{gfxmode} (default: @code{'("auto")})
28198 The GRUB @code{gfxmode} to set (a list of screen resolution strings, see
28199 @pxref{gfxmode,,, grub, GNU GRUB manual}).
28203 @deffn {Scheme Procedure} grub-theme
28204 Return the default GRUB theme used by the operating system if no
28205 @code{theme} field is specified in @code{bootloader-configuration}
28208 It comes with a fancy background image displaying the GNU and Guix
28212 For example, to override the default resolution, you may use something
28217 (bootloader-configuration
28220 (inherit (grub-theme))
28221 (gfxmode '("1024x786x32" "auto"))))))
28224 @node Invoking guix system
28225 @section Invoking @code{guix system}
28227 Once you have written an operating system declaration as seen in the
28228 previous section, it can be @dfn{instantiated} using the @command{guix
28229 system} command. The synopsis is:
28232 guix system @var{options}@dots{} @var{action} @var{file}
28235 @var{file} must be the name of a file containing an
28236 @code{operating-system} declaration. @var{action} specifies how the
28237 operating system is instantiated. Currently the following values are
28242 Display available service type definitions that match the given regular
28243 expressions, sorted by relevance:
28249 $ guix system search console
28250 name: console-fonts
28251 location: gnu/services/base.scm:806:2
28252 extends: shepherd-root
28253 description: Install the given fonts on the specified ttys (fonts are per
28254 + virtual console on GNU/Linux). The value of this service is a list of
28255 + tty/font pairs. The font can be the name of a font provided by the `kbd'
28256 + package or any valid argument to `setfont', as in this example:
28258 + '(("tty1" . "LatGrkCyr-8x16")
28259 + ("tty2" . (file-append
28261 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
28262 + ("tty3" . (file-append
28264 + "/share/consolefonts/ter-132n"))) ; for HDPI
28268 location: gnu/services/base.scm:1190:2
28269 extends: shepherd-root
28270 description: Provide console login using the `mingetty' program.
28274 location: gnu/services/base.scm:860:2
28276 description: Provide a console log-in service as specified by its
28277 + configuration value, a `login-configuration' object.
28283 As for @command{guix package --search}, the result is written in
28284 @code{recutils} format, which makes it easy to filter the output
28285 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
28288 Build the operating system described in @var{file}, activate it, and
28289 switch to it@footnote{This action (and the related actions
28290 @code{switch-generation} and @code{roll-back}) are usable only on
28291 systems already running Guix System.}.
28294 @c The paragraph below refers to the problem discussed at
28295 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
28296 It is highly recommended to run @command{guix pull} once before you run
28297 @command{guix system reconfigure} for the first time (@pxref{Invoking
28298 guix pull}). Failing to do that you would see an older version of Guix
28299 once @command{reconfigure} has completed.
28302 This effects all the configuration specified in @var{file}: user
28303 accounts, system services, global package list, setuid programs, etc.
28304 The command starts system services specified in @var{file} that are not
28305 currently running; if a service is currently running this command will
28306 arrange for it to be upgraded the next time it is stopped (e.g.@: by
28307 @code{herd stop X} or @code{herd restart X}).
28309 This command creates a new generation whose number is one greater than
28310 the current generation (as reported by @command{guix system
28311 list-generations}). If that generation already exists, it will be
28312 overwritten. This behavior mirrors that of @command{guix package}
28313 (@pxref{Invoking guix package}).
28315 It also adds a bootloader menu entry for the new OS configuration,
28316 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
28317 entries for older configurations to a submenu, allowing you to choose
28318 an older system generation at boot time should you need it.
28320 @cindex provenance tracking, of the operating system
28321 Upon completion, the new system is deployed under
28322 @file{/run/current-system}. This directory contains @dfn{provenance
28323 meta-data}: the list of channels in use (@pxref{Channels}) and
28324 @var{file} itself, when available. This information is useful should
28325 you later want to inspect how this particular generation was built.
28327 In fact, assuming @var{file} is self-contained, you can later rebuild
28328 generation @var{n} of your operating system with:
28331 guix time-machine \
28332 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
28333 system reconfigure \
28334 /var/guix/profiles/system-@var{n}-link/configuration.scm
28337 You can think of it as some sort of built-in version control! Your
28338 system is not just a binary artifact: @emph{it carries its own source}.
28339 @xref{Service Reference, @code{provenance-service-type}}, for more
28340 information on provenance tracking.
28342 @item switch-generation
28343 @cindex generations
28344 Switch to an existing system generation. This action atomically
28345 switches the system profile to the specified system generation. It
28346 also rearranges the system's existing bootloader menu entries. It
28347 makes the menu entry for the specified system generation the default,
28348 and it moves the entries for the other generations to a submenu, if
28349 supported by the bootloader being used. The next time the system
28350 boots, it will use the specified system generation.
28352 The bootloader itself is not being reinstalled when using this
28353 command. Thus, the installed bootloader is used with an updated
28354 configuration file.
28356 The target generation can be specified explicitly by its generation
28357 number. For example, the following invocation would switch to system
28361 guix system switch-generation 7
28364 The target generation can also be specified relative to the current
28365 generation with the form @code{+N} or @code{-N}, where @code{+3} means
28366 ``3 generations ahead of the current generation,'' and @code{-1} means
28367 ``1 generation prior to the current generation.'' When specifying a
28368 negative value such as @code{-1}, you must precede it with @code{--} to
28369 prevent it from being parsed as an option. For example:
28372 guix system switch-generation -- -1
28375 Currently, the effect of invoking this action is @emph{only} to switch
28376 the system profile to an existing generation and rearrange the
28377 bootloader menu entries. To actually start using the target system
28378 generation, you must reboot after running this action. In the future,
28379 it will be updated to do the same things as @command{reconfigure},
28380 like activating and deactivating services.
28382 This action will fail if the specified generation does not exist.
28385 @cindex rolling back
28386 Switch to the preceding system generation. The next time the system
28387 boots, it will use the preceding system generation. This is the inverse
28388 of @command{reconfigure}, and it is exactly the same as invoking
28389 @command{switch-generation} with an argument of @code{-1}.
28391 Currently, as with @command{switch-generation}, you must reboot after
28392 running this action to actually start using the preceding system
28395 @item delete-generations
28396 @cindex deleting system generations
28397 @cindex saving space
28398 Delete system generations, making them candidates for garbage collection
28399 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
28402 This works in the same way as @samp{guix package --delete-generations}
28403 (@pxref{Invoking guix package, @option{--delete-generations}}). With no
28404 arguments, all system generations but the current one are deleted:
28407 guix system delete-generations
28410 You can also select the generations you want to delete. The example below
28411 deletes all the system generations that are more than two month old:
28414 guix system delete-generations 2m
28417 Running this command automatically reinstalls the bootloader with an updated
28418 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
28419 longer lists the generations that have been deleted.
28422 Build the derivation of the operating system, which includes all the
28423 configuration files and programs needed to boot and run the system.
28424 This action does not actually install anything.
28427 Populate the given directory with all the files necessary to run the
28428 operating system specified in @var{file}. This is useful for first-time
28429 installations of Guix System. For instance:
28432 guix system init my-os-config.scm /mnt
28435 copies to @file{/mnt} all the store items required by the configuration
28436 specified in @file{my-os-config.scm}. This includes configuration
28437 files, packages, and so on. It also creates other essential files
28438 needed for the system to operate correctly---e.g., the @file{/etc},
28439 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
28441 This command also installs bootloader on the target specified in
28442 @file{my-os-config}, unless the @option{--no-bootloader} option was
28446 @cindex virtual machine
28448 @anchor{guix system vm}
28449 Build a virtual machine that contains the operating system declared in
28450 @var{file}, and return a script to run that virtual machine (VM).
28453 The @code{vm} action and others below
28454 can use KVM support in the Linux-libre kernel. Specifically, if the
28455 machine has hardware virtualization support, the corresponding
28456 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
28457 must exist and be readable and writable by the user and by the
28458 build users of the daemon (@pxref{Build Environment Setup}).
28461 Arguments given to the script are passed to QEMU as in the example
28462 below, which enables networking and requests 1@tie{}GiB of RAM for the
28466 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
28469 The VM shares its store with the host system.
28471 Additional file systems can be shared between the host and the VM using
28472 the @option{--share} and @option{--expose} command-line options: the former
28473 specifies a directory to be shared with write access, while the latter
28474 provides read-only access to the shared directory.
28476 The example below creates a VM in which the user's home directory is
28477 accessible read-only, and where the @file{/exchange} directory is a
28478 read-write mapping of @file{$HOME/tmp} on the host:
28481 guix system vm my-config.scm \
28482 --expose=$HOME --share=$HOME/tmp=/exchange
28485 On GNU/Linux, the default is to boot directly to the kernel; this has
28486 the advantage of requiring only a very tiny root disk image since the
28487 store of the host can then be mounted.
28489 The @option{--full-boot} option forces a complete boot sequence, starting
28490 with the bootloader. This requires more disk space since a root image
28491 containing at least the kernel, initrd, and bootloader data files must
28492 be created. The @option{--image-size} option can be used to specify the
28495 @cindex System images, creation in various formats
28496 @cindex Creating system images in various formats
28499 @itemx docker-image
28500 Return a virtual machine, disk image, or Docker image of the operating
28501 system declared in @var{file} that stands alone. By default,
28502 @command{guix system} estimates the size of the image needed to store
28503 the system, but you can use the @option{--image-size} option to specify
28504 a value. Docker images are built to contain exactly what they need, so
28505 the @option{--image-size} option is ignored in the case of
28506 @code{docker-image}.
28508 You can specify the root file system type by using the
28509 @option{--file-system-type} option. It defaults to @code{ext4}.
28511 When using @code{vm-image}, the returned image is in qcow2 format, which
28512 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
28513 for more information on how to run the image in a virtual machine.
28515 When using @code{disk-image}, a raw disk image is produced; it can be
28516 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
28517 the device corresponding to a USB stick, one can copy the image to it
28518 using the following command:
28521 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc status=progress
28524 When using @code{docker-image}, a Docker image is produced. Guix builds
28525 the image from scratch, not from a pre-existing Docker base image. As a
28526 result, it contains @emph{exactly} what you define in the operating
28527 system configuration file. You can then load the image and launch a
28528 Docker container using commands like the following:
28531 image_id="`docker load < guix-system-docker-image.tar.gz`"
28532 container_id="`docker create $image_id`"
28533 docker start $container_id
28536 This command starts a new Docker container from the specified image. It
28537 will boot the Guix system in the usual manner, which means it will
28538 start any services you have defined in the operating system
28539 configuration. You can get an interactive shell running in the container
28540 using @command{docker exec}:
28543 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
28546 Depending on what you run in the Docker container, it
28547 may be necessary to give the container additional permissions. For
28548 example, if you intend to build software using Guix inside of the Docker
28549 container, you may need to pass the @option{--privileged} option to
28550 @code{docker create}.
28552 Last, the @option{--network} option applies to @command{guix system
28553 docker-image}: it produces an image where network is supposedly shared
28554 with the host, and thus without services like nscd or NetworkManager.
28557 Return a script to run the operating system declared in @var{file}
28558 within a container. Containers are a set of lightweight isolation
28559 mechanisms provided by the kernel Linux-libre. Containers are
28560 substantially less resource-demanding than full virtual machines since
28561 the kernel, shared objects, and other resources can be shared with the
28562 host system; this also means they provide thinner isolation.
28564 Currently, the script must be run as root in order to support more than
28565 a single user and group. The container shares its store with the host
28568 As with the @code{vm} action (@pxref{guix system vm}), additional file
28569 systems to be shared between the host and container can be specified
28570 using the @option{--share} and @option{--expose} options:
28573 guix system container my-config.scm \
28574 --expose=$HOME --share=$HOME/tmp=/exchange
28578 This option requires Linux-libre 3.19 or newer.
28583 @var{options} can contain any of the common build options (@pxref{Common
28584 Build Options}). In addition, @var{options} can contain one of the
28588 @item --expression=@var{expr}
28589 @itemx -e @var{expr}
28590 Consider the operating-system @var{expr} evaluates to.
28591 This is an alternative to specifying a file which evaluates to an
28593 This is used to generate the Guix system installer @pxref{Building the
28594 Installation Image}).
28596 @item --system=@var{system}
28597 @itemx -s @var{system}
28598 Attempt to build for @var{system} instead of the host system type.
28599 This works as per @command{guix build} (@pxref{Invoking guix build}).
28603 Return the derivation file name of the given operating system without
28606 @cindex provenance tracking, of the operating system
28607 @item --save-provenance
28608 As discussed above, @command{guix system init} and @command{guix system
28609 reconfigure} always save provenance information @i{via} a dedicated
28610 service (@pxref{Service Reference, @code{provenance-service-type}}).
28611 However, other commands don't do that by default. If you wish to, say,
28612 create a virtual machine image that contains provenance information, you
28616 guix system vm-image --save-provenance config.scm
28619 That way, the resulting image will effectively ``embed its own source''
28620 in the form of meta-data in @file{/run/current-system}. With that
28621 information, one can rebuild the image to make sure it really contains
28622 what it pretends to contain; or they could use that to derive a variant
28625 @item --file-system-type=@var{type}
28626 @itemx -t @var{type}
28627 For the @code{disk-image} action, create a file system of the given
28628 @var{type} on the image.
28630 When this option is omitted, @command{guix system} uses @code{ext4}.
28632 @cindex ISO-9660 format
28633 @cindex CD image format
28634 @cindex DVD image format
28635 @option{--file-system-type=iso9660} produces an ISO-9660 image, suitable
28636 for burning on CDs and DVDs.
28638 @item --image-size=@var{size}
28639 For the @code{vm-image} and @code{disk-image} actions, create an image
28640 of the given @var{size}. @var{size} may be a number of bytes, or it may
28641 include a unit as a suffix (@pxref{Block size, size specifications,,
28642 coreutils, GNU Coreutils}).
28644 When this option is omitted, @command{guix system} computes an estimate
28645 of the image size as a function of the size of the system declared in
28650 For the @code{container} action, allow containers to access the host network,
28651 that is, do not create a network namespace.
28653 @item --root=@var{file}
28654 @itemx -r @var{file}
28655 Make @var{file} a symlink to the result, and register it as a garbage
28658 @item --skip-checks
28659 Skip pre-installation safety checks.
28661 By default, @command{guix system init} and @command{guix system
28662 reconfigure} perform safety checks: they make sure the file systems that
28663 appear in the @code{operating-system} declaration actually exist
28664 (@pxref{File Systems}), and that any Linux kernel modules that may be
28665 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
28666 RAM Disk}). Passing this option skips these tests altogether.
28669 @cindex on-error strategy
28670 @cindex error strategy
28671 @item --on-error=@var{strategy}
28672 Apply @var{strategy} when an error occurs when reading @var{file}.
28673 @var{strategy} may be one of the following:
28676 @item nothing-special
28677 Report the error concisely and exit. This is the default strategy.
28680 Likewise, but also display a backtrace.
28683 Report the error and enter Guile's debugger. From there, you can run
28684 commands such as @code{,bt} to get a backtrace, @code{,locals} to
28685 display local variable values, and more generally inspect the state of the
28686 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
28687 a list of available debugging commands.
28691 Once you have built, configured, re-configured, and re-re-configured
28692 your Guix installation, you may find it useful to list the operating
28693 system generations available on disk---and that you can choose from the
28694 bootloader boot menu:
28699 Describe the current system generation: its file name, the kernel and
28700 bootloader used, etc., as well as provenance information when available.
28702 @item list-generations
28703 List a summary of each generation of the operating system available on
28704 disk, in a human-readable way. This is similar to the
28705 @option{--list-generations} option of @command{guix package}
28706 (@pxref{Invoking guix package}).
28708 Optionally, one can specify a pattern, with the same syntax that is used
28709 in @command{guix package --list-generations}, to restrict the list of
28710 generations displayed. For instance, the following command displays
28711 generations that are up to 10 days old:
28714 $ guix system list-generations 10d
28719 The @command{guix system} command has even more to offer! The following
28720 sub-commands allow you to visualize how your system services relate to
28723 @anchor{system-extension-graph}
28726 @item extension-graph
28727 Emit in Dot/Graphviz format to standard output the @dfn{service
28728 extension graph} of the operating system defined in @var{file}
28729 (@pxref{Service Composition}, for more information on service
28735 $ guix system extension-graph @var{file} | xdot -
28738 shows the extension relations among services.
28740 @anchor{system-shepherd-graph}
28741 @item shepherd-graph
28742 Emit in Dot/Graphviz format to standard output the @dfn{dependency
28743 graph} of shepherd services of the operating system defined in
28744 @var{file}. @xref{Shepherd Services}, for more information and for an
28749 @node Invoking guix deploy
28750 @section Invoking @code{guix deploy}
28752 We've already seen @code{operating-system} declarations used to manage a
28753 machine's configuration locally. Suppose you need to configure multiple
28754 machines, though---perhaps you're managing a service on the web that's
28755 comprised of several servers. @command{guix deploy} enables you to use those
28756 same @code{operating-system} declarations to manage multiple remote hosts at
28757 once as a logical ``deployment''.
28760 The functionality described in this section is still under development
28761 and is subject to change. Get in touch with us on
28762 @email{guix-devel@@gnu.org}!
28766 guix deploy @var{file}
28769 Such an invocation will deploy the machines that the code within @var{file}
28770 evaluates to. As an example, @var{file} might contain a definition like this:
28773 ;; This is a Guix deployment of a "bare bones" setup, with
28774 ;; no X11 display server, to a machine with an SSH daemon
28775 ;; listening on localhost:2222. A configuration such as this
28776 ;; may be appropriate for virtual machine with ports
28777 ;; forwarded to the host's loopback interface.
28779 (use-service-modules networking ssh)
28780 (use-package-modules bootloaders)
28784 (host-name "gnu-deployed")
28785 (timezone "Etc/UTC")
28786 (bootloader (bootloader-configuration
28787 (bootloader grub-bootloader)
28788 (target "/dev/vda")
28789 (terminal-outputs '(console))))
28790 (file-systems (cons (file-system
28792 (device "/dev/vda1")
28794 %base-file-systems))
28796 (append (list (service dhcp-client-service-type)
28797 (service openssh-service-type
28798 (openssh-configuration
28799 (permit-root-login #t)
28800 (allow-empty-passwords? #t))))
28804 (operating-system %system)
28805 (environment managed-host-environment-type)
28806 (configuration (machine-ssh-configuration
28807 (host-name "localhost")
28808 (system "x86_64-linux")
28810 (identity "./id_rsa")
28814 The file should evaluate to a list of @var{machine} objects. This example,
28815 upon being deployed, will create a new generation on the remote system
28816 realizing the @code{operating-system} declaration @code{%system}.
28817 @code{environment} and @code{configuration} specify how the machine should be
28818 provisioned---that is, how the computing resources should be created and
28819 managed. The above example does not create any resources, as a
28820 @code{'managed-host} is a machine that is already running the Guix system and
28821 available over the network. This is a particularly simple case; a more
28822 complex deployment may involve, for example, starting virtual machines through
28823 a Virtual Private Server (VPS) provider. In such a case, a different
28824 @var{environment} type would be used.
28826 Do note that you first need to generate a key pair on the coordinator machine
28827 to allow the daemon to export signed archives of files from the store
28828 (@pxref{Invoking guix archive}).
28831 # guix archive --generate-key
28835 Each target machine must authorize the key of the master machine so that it
28836 accepts store items it receives from the coordinator:
28839 # guix archive --authorize < coordinator-public-key.txt
28842 @code{user}, in this example, specifies the name of the user account to log in
28843 as to perform the deployment. Its default value is @code{root}, but root
28844 login over SSH may be forbidden in some cases. To work around this,
28845 @command{guix deploy} can log in as an unprivileged user and employ
28846 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
28847 currently installed on the remote and can be invoked non-interactively as
28848 @code{user}. That is, the line in @code{sudoers} granting @code{user} the
28849 ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
28850 be accomplished with the following operating system configuration snippet:
28854 (gnu system)) ;for %sudoers-specification
28856 (define %user "username")
28861 (plain-file "sudoers"
28862 (string-append (plain-file-content %sudoers-specification)
28863 (format #f "~a ALL = NOPASSWD: ALL~%"
28868 For more information regarding the format of the @file{sudoers} file,
28869 consult @command{man sudoers}.
28871 @deftp {Data Type} machine
28872 This is the data type representing a single machine in a heterogeneous Guix
28876 @item @code{operating-system}
28877 The object of the operating system configuration to deploy.
28879 @item @code{environment}
28880 An @code{environment-type} describing how the machine should be provisioned.
28882 @item @code{configuration} (default: @code{#f})
28883 An object describing the configuration for the machine's @code{environment}.
28884 If the @code{environment} has a default configuration, @code{#f} may be used.
28885 If @code{#f} is used for an environment with no default configuration,
28886 however, an error will be thrown.
28890 @deftp {Data Type} machine-ssh-configuration
28891 This is the data type representing the SSH client parameters for a machine
28892 with an @code{environment} of @code{managed-host-environment-type}.
28895 @item @code{host-name}
28896 @item @code{build-locally?} (default: @code{#t})
28897 If false, system derivations will be built on the machine being deployed to.
28898 @item @code{system}
28899 The system type describing the architecture of the machine being deployed
28900 to---e.g., @code{"x86_64-linux"}.
28901 @item @code{authorize?} (default: @code{#t})
28902 If true, the coordinator's signing key will be added to the remote's ACL
28904 @item @code{port} (default: @code{22})
28905 @item @code{user} (default: @code{"root"})
28906 @item @code{identity} (default: @code{#f})
28907 If specified, the path to the SSH private key to use to authenticate with the
28910 @item @code{host-key} (default: @code{#f})
28911 This should be the SSH host key of the machine, which looks like this:
28914 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
28917 When @code{host-key} is @code{#f}, the server is authenticated against
28918 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
28924 @deftp {Data Type} digital-ocean-configuration
28925 This is the data type describing the Droplet that should be created for a
28926 machine with an @code{environment} of @code{digital-ocean-environment-type}.
28929 @item @code{ssh-key}
28930 The path to the SSH private key to use to authenticate with the remote
28931 host. In the future, this field may not exist.
28933 A list of string ``tags'' that uniquely identify the machine. Must be given
28934 such that no two machines in the deployment have the same set of tags.
28935 @item @code{region}
28936 A Digital Ocean region slug, such as @code{"nyc3"}.
28938 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
28939 @item @code{enable-ipv6?}
28940 Whether or not the droplet should be created with IPv6 networking.
28944 @node Running Guix in a VM
28945 @section Running Guix in a Virtual Machine
28947 @cindex virtual machine
28948 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
28950 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
28951 This image is a compressed image in QCOW format. You will first need to
28952 decompress with @command{xz -d}, and then you can pass it to an emulator such
28953 as QEMU (see below for details).
28955 This image boots the Xfce graphical environment and it contains some
28956 commonly-used tools. You can install more software in the image by running
28957 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
28958 also reconfigure the system based on its initial configuration file available
28959 as @file{/run/current-system/configuration.scm} (@pxref{Using the
28960 Configuration System}).
28962 Instead of using this pre-built image, one can also build their own virtual
28963 machine image using @command{guix system vm-image} (@pxref{Invoking guix
28964 system}). The returned image is in qcow2 format, which the
28965 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
28968 If you built your own image, you must copy it out of the store
28969 (@pxref{The Store}) and give yourself permission to write to the copy
28970 before you can use it. When invoking QEMU, you must choose a system
28971 emulator that is suitable for your hardware platform. Here is a minimal
28972 QEMU invocation that will boot the result of @command{guix system
28973 vm-image} on x86_64 hardware:
28976 $ qemu-system-x86_64 \
28977 -nic user,model=virtio-net-pci \
28978 -enable-kvm -m 1024 \
28979 -device virtio-blk,drive=myhd \
28980 -drive if=none,file=/tmp/qemu-image,id=myhd
28983 Here is what each of these options means:
28986 @item qemu-system-x86_64
28987 This specifies the hardware platform to emulate. This should match the
28990 @item -nic user,model=virtio-net-pci
28991 Enable the unprivileged user-mode network stack. The guest OS can
28992 access the host but not vice versa. This is the simplest way to get the
28993 guest OS online. @code{model} specifies which network device to emulate:
28994 @code{virtio-net-pci} is a special device made for virtualized operating
28995 systems and recommended for most uses. Assuming your hardware platform is
28996 x86_64, you can get a list of available NIC models by running
28997 @command{qemu-system-x86_64 -nic model=help}.
29000 If your system has hardware virtualization extensions, enabling the
29001 virtual machine support (KVM) of the Linux kernel will make things run
29004 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
29006 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
29007 which may be insufficient for some operations.
29009 @item -device virtio-blk,drive=myhd
29010 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
29011 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
29012 better performance than if it were emulating a complete disk drive. See the
29013 QEMU and KVM documentation for more info.
29015 @item -drive if=none,file=/tmp/qemu-image,id=myhd
29016 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
29017 the ``myhd'' drive.
29020 The default @command{run-vm.sh} script that is returned by an invocation of
29021 @command{guix system vm} does not add a @command{-nic user} flag by default.
29022 To get network access from within the vm add the @code{(dhcp-client-service)}
29023 to your system definition and start the VM using
29024 @command{`guix system vm config.scm` -nic user}. An important caveat of using
29025 @command{-nic user} for networking is that @command{ping} will not work, because
29026 it uses the ICMP protocol. You'll have to use a different command to check for
29027 network connectivity, for example @command{guix download}.
29029 @subsection Connecting Through SSH
29033 To enable SSH inside a VM you need to add an SSH server like
29034 @code{openssh-service-type} to your VM (@pxref{Networking Services,
29035 @code{openssh-service-type}}). In addition you need to forward the SSH port,
29036 22 by default, to the host. You can do this with
29039 `guix system vm config.scm` -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
29042 To connect to the VM you can run
29045 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
29048 The @command{-p} tells @command{ssh} the port you want to connect to.
29049 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
29050 every time you modify your @command{config.scm} file and the
29051 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
29052 connection to an unknown host every time you connect.
29054 @subsection Using @command{virt-viewer} with Spice
29056 As an alternative to the default @command{qemu} graphical client you can
29057 use the @command{remote-viewer} from the @command{virt-viewer} package. To
29058 connect pass the @command{-spice port=5930,disable-ticketing} flag to
29059 @command{qemu}. See previous section for further information on how to do this.
29061 Spice also allows you to do some nice stuff like share your clipboard with your
29062 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
29065 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
29066 -chardev spicevmc,name=vdagent,id=vdagent
29067 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
29068 name=com.redhat.spice.0
29071 You'll also need to add the @code{(spice-vdagent-service)} to your
29072 system definition (@pxref{Miscellaneous Services, Spice service}).
29074 @node Defining Services
29075 @section Defining Services
29077 The previous sections show the available services and how one can combine
29078 them in an @code{operating-system} declaration. But how do we define
29079 them in the first place? And what is a service anyway?
29082 * Service Composition:: The model for composing services.
29083 * Service Types and Services:: Types and services.
29084 * Service Reference:: API reference.
29085 * Shepherd Services:: A particular type of service.
29088 @node Service Composition
29089 @subsection Service Composition
29093 Here we define a @dfn{service} as, broadly, something that extends the
29094 functionality of the operating system. Often a service is a process---a
29095 @dfn{daemon}---started when the system boots: a secure shell server, a
29096 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
29097 whose execution can be triggered by another daemon---e.g., an FTP server
29098 started by @command{inetd} or a D-Bus service activated by
29099 @command{dbus-daemon}. Occasionally, a service does not map to a
29100 daemon. For instance, the ``account'' service collects user accounts
29101 and makes sure they exist when the system runs; the ``udev'' service
29102 collects device management rules and makes them available to the eudev
29103 daemon; the @file{/etc} service populates the @file{/etc} directory
29106 @cindex service extensions
29107 Guix system services are connected by @dfn{extensions}. For instance, the
29108 secure shell service @emph{extends} the Shepherd---the
29109 initialization system, running as PID@tie{}1---by giving it the command
29110 lines to start and stop the secure shell daemon (@pxref{Networking
29111 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
29112 service by passing it its @file{.service} specification, and extends the
29113 udev service by passing it device management rules (@pxref{Desktop
29114 Services, @code{upower-service}}); the Guix daemon service extends the
29115 Shepherd by passing it the command lines to start and stop the daemon,
29116 and extends the account service by passing it a list of required build
29117 user accounts (@pxref{Base Services}).
29119 All in all, services and their ``extends'' relations form a directed
29120 acyclic graph (DAG). If we represent services as boxes and extensions
29121 as arrows, a typical system might provide something like this:
29123 @image{images/service-graph,,5in,Typical service extension graph.}
29125 @cindex system service
29126 At the bottom, we see the @dfn{system service}, which produces the
29127 directory containing everything to run and boot the system, as returned
29128 by the @command{guix system build} command. @xref{Service Reference},
29129 to learn about the other service types shown here.
29130 @xref{system-extension-graph, the @command{guix system extension-graph}
29131 command}, for information on how to generate this representation for a
29132 particular operating system definition.
29134 @cindex service types
29135 Technically, developers can define @dfn{service types} to express these
29136 relations. There can be any number of services of a given type on the
29137 system---for instance, a system running two instances of the GNU secure
29138 shell server (lsh) has two instances of @code{lsh-service-type}, with
29139 different parameters.
29141 The following section describes the programming interface for service
29142 types and services.
29144 @node Service Types and Services
29145 @subsection Service Types and Services
29147 A @dfn{service type} is a node in the DAG described above. Let us start
29148 with a simple example, the service type for the Guix build daemon
29149 (@pxref{Invoking guix-daemon}):
29152 (define guix-service-type
29156 (list (service-extension shepherd-root-service-type guix-shepherd-service)
29157 (service-extension account-service-type guix-accounts)
29158 (service-extension activation-service-type guix-activation)))
29159 (default-value (guix-configuration))))
29163 It defines three things:
29167 A name, whose sole purpose is to make inspection and debugging easier.
29170 A list of @dfn{service extensions}, where each extension designates the
29171 target service type and a procedure that, given the parameters of the
29172 service, returns a list of objects to extend the service of that type.
29174 Every service type has at least one service extension. The only
29175 exception is the @dfn{boot service type}, which is the ultimate service.
29178 Optionally, a default value for instances of this type.
29181 In this example, @code{guix-service-type} extends three services:
29184 @item shepherd-root-service-type
29185 The @code{guix-shepherd-service} procedure defines how the Shepherd
29186 service is extended. Namely, it returns a @code{<shepherd-service>}
29187 object that defines how @command{guix-daemon} is started and stopped
29188 (@pxref{Shepherd Services}).
29190 @item account-service-type
29191 This extension for this service is computed by @code{guix-accounts},
29192 which returns a list of @code{user-group} and @code{user-account}
29193 objects representing the build user accounts (@pxref{Invoking
29196 @item activation-service-type
29197 Here @code{guix-activation} is a procedure that returns a gexp, which is
29198 a code snippet to run at ``activation time''---e.g., when the service is
29202 A service of this type is instantiated like this:
29205 (service guix-service-type
29206 (guix-configuration
29208 (use-substitutes? #f)))
29211 The second argument to the @code{service} form is a value representing
29212 the parameters of this specific service instance.
29213 @xref{guix-configuration-type, @code{guix-configuration}}, for
29214 information about the @code{guix-configuration} data type. When the
29215 value is omitted, the default value specified by
29216 @code{guix-service-type} is used:
29219 (service guix-service-type)
29222 @code{guix-service-type} is quite simple because it extends other
29223 services but is not extensible itself.
29225 @c @subsubsubsection Extensible Service Types
29227 The service type for an @emph{extensible} service looks like this:
29230 (define udev-service-type
29231 (service-type (name 'udev)
29233 (list (service-extension shepherd-root-service-type
29234 udev-shepherd-service)))
29236 (compose concatenate) ;concatenate the list of rules
29237 (extend (lambda (config rules)
29239 (($ <udev-configuration> udev initial-rules)
29240 (udev-configuration
29241 (udev udev) ;the udev package to use
29242 (rules (append initial-rules rules)))))))))
29245 This is the service type for the
29246 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
29247 management daemon}. Compared to the previous example, in addition to an
29248 extension of @code{shepherd-root-service-type}, we see two new fields:
29252 This is the procedure to @dfn{compose} the list of extensions to
29253 services of this type.
29255 Services can extend the udev service by passing it lists of rules; we
29256 compose those extensions simply by concatenating them.
29259 This procedure defines how the value of the service is @dfn{extended} with
29260 the composition of the extensions.
29262 Udev extensions are composed into a list of rules, but the udev service
29263 value is itself a @code{<udev-configuration>} record. So here, we
29264 extend that record by appending the list of rules it contains to the
29265 list of contributed rules.
29268 This is a string giving an overview of the service type. The string can
29269 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
29270 @command{guix system search} command searches these strings and displays
29271 them (@pxref{Invoking guix system}).
29274 There can be only one instance of an extensible service type such as
29275 @code{udev-service-type}. If there were more, the
29276 @code{service-extension} specifications would be ambiguous.
29278 Still here? The next section provides a reference of the programming
29279 interface for services.
29281 @node Service Reference
29282 @subsection Service Reference
29284 We have seen an overview of service types (@pxref{Service Types and
29285 Services}). This section provides a reference on how to manipulate
29286 services and service types. This interface is provided by the
29287 @code{(gnu services)} module.
29289 @deffn {Scheme Procedure} service @var{type} [@var{value}]
29290 Return a new service of @var{type}, a @code{<service-type>} object (see
29291 below). @var{value} can be any object; it represents the parameters of
29292 this particular service instance.
29294 When @var{value} is omitted, the default value specified by @var{type}
29295 is used; if @var{type} does not specify a default value, an error is
29298 For instance, this:
29301 (service openssh-service-type)
29305 is equivalent to this:
29308 (service openssh-service-type
29309 (openssh-configuration))
29312 In both cases the result is an instance of @code{openssh-service-type}
29313 with the default configuration.
29316 @deffn {Scheme Procedure} service? @var{obj}
29317 Return true if @var{obj} is a service.
29320 @deffn {Scheme Procedure} service-kind @var{service}
29321 Return the type of @var{service}---i.e., a @code{<service-type>} object.
29324 @deffn {Scheme Procedure} service-value @var{service}
29325 Return the value associated with @var{service}. It represents its
29329 Here is an example of how a service is created and manipulated:
29333 (service nginx-service-type
29334 (nginx-configuration
29336 (log-directory log-directory)
29337 (run-directory run-directory)
29338 (file config-file))))
29343 (eq? (service-kind s) nginx-service-type)
29347 The @code{modify-services} form provides a handy way to change the
29348 parameters of some of the services of a list such as
29349 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
29350 evaluates to a list of services. Of course, you could always use
29351 standard list combinators such as @code{map} and @code{fold} to do that
29352 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
29353 @code{modify-services} simply provides a more concise form for this
29356 @deffn {Scheme Syntax} modify-services @var{services} @
29357 (@var{type} @var{variable} => @var{body}) @dots{}
29359 Modify the services listed in @var{services} according to the given
29360 clauses. Each clause has the form:
29363 (@var{type} @var{variable} => @var{body})
29366 where @var{type} is a service type---e.g.,
29367 @code{guix-service-type}---and @var{variable} is an identifier that is
29368 bound within the @var{body} to the service parameters---e.g., a
29369 @code{guix-configuration} instance---of the original service of that
29372 The @var{body} should evaluate to the new service parameters, which will
29373 be used to configure the new service. This new service will replace the
29374 original in the resulting list. Because a service's service parameters
29375 are created using @code{define-record-type*}, you can write a succinct
29376 @var{body} that evaluates to the new service parameters by using the
29377 @code{inherit} feature that @code{define-record-type*} provides.
29379 @xref{Using the Configuration System}, for example usage.
29383 Next comes the programming interface for service types. This is
29384 something you want to know when writing new service definitions, but not
29385 necessarily when simply looking for ways to customize your
29386 @code{operating-system} declaration.
29388 @deftp {Data Type} service-type
29389 @cindex service type
29390 This is the representation of a @dfn{service type} (@pxref{Service Types
29395 This is a symbol, used only to simplify inspection and debugging.
29397 @item @code{extensions}
29398 A non-empty list of @code{<service-extension>} objects (see below).
29400 @item @code{compose} (default: @code{#f})
29401 If this is @code{#f}, then the service type denotes services that cannot
29402 be extended---i.e., services that do not receive ``values'' from other
29405 Otherwise, it must be a one-argument procedure. The procedure is called
29406 by @code{fold-services} and is passed a list of values collected from
29407 extensions. It may return any single value.
29409 @item @code{extend} (default: @code{#f})
29410 If this is @code{#f}, services of this type cannot be extended.
29412 Otherwise, it must be a two-argument procedure: @code{fold-services}
29413 calls it, passing it the initial value of the service as the first
29414 argument and the result of applying @code{compose} to the extension
29415 values as the second argument. It must return a value that is a valid
29416 parameter value for the service instance.
29419 @xref{Service Types and Services}, for examples.
29422 @deffn {Scheme Procedure} service-extension @var{target-type} @
29424 Return a new extension for services of type @var{target-type}.
29425 @var{compute} must be a one-argument procedure: @code{fold-services}
29426 calls it, passing it the value associated with the service that provides
29427 the extension; it must return a valid value for the target service.
29430 @deffn {Scheme Procedure} service-extension? @var{obj}
29431 Return true if @var{obj} is a service extension.
29434 Occasionally, you might want to simply extend an existing service. This
29435 involves creating a new service type and specifying the extension of
29436 interest, which can be verbose; the @code{simple-service} procedure
29437 provides a shorthand for this.
29439 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
29440 Return a service that extends @var{target} with @var{value}. This works
29441 by creating a singleton service type @var{name}, of which the returned
29442 service is an instance.
29444 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
29448 (simple-service 'my-mcron-job mcron-service-type
29449 #~(job '(next-hour (3)) "guix gc -F 2G"))
29453 At the core of the service abstraction lies the @code{fold-services}
29454 procedure, which is responsible for ``compiling'' a list of services
29455 down to a single directory that contains everything needed to boot and
29456 run the system---the directory shown by the @command{guix system build}
29457 command (@pxref{Invoking guix system}). In essence, it propagates
29458 service extensions down the service graph, updating each node parameters
29459 on the way, until it reaches the root node.
29461 @deffn {Scheme Procedure} fold-services @var{services} @
29462 [#:target-type @var{system-service-type}]
29463 Fold @var{services} by propagating their extensions down to the root of
29464 type @var{target-type}; return the root service adjusted accordingly.
29467 Lastly, the @code{(gnu services)} module also defines several essential
29468 service types, some of which are listed below.
29470 @defvr {Scheme Variable} system-service-type
29471 This is the root of the service graph. It produces the system directory
29472 as returned by the @command{guix system build} command.
29475 @defvr {Scheme Variable} boot-service-type
29476 The type of the ``boot service'', which produces the @dfn{boot script}.
29477 The boot script is what the initial RAM disk runs when booting.
29480 @defvr {Scheme Variable} etc-service-type
29481 The type of the @file{/etc} service. This service is used to create
29482 files under @file{/etc} and can be extended by
29483 passing it name/file tuples such as:
29486 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
29489 In this example, the effect would be to add an @file{/etc/issue} file
29490 pointing to the given file.
29493 @defvr {Scheme Variable} setuid-program-service-type
29494 Type for the ``setuid-program service''. This service collects lists of
29495 executable file names, passed as gexps, and adds them to the set of
29496 setuid-root programs on the system (@pxref{Setuid Programs}).
29499 @defvr {Scheme Variable} profile-service-type
29500 Type of the service that populates the @dfn{system profile}---i.e., the
29501 programs under @file{/run/current-system/profile}. Other services can
29502 extend it by passing it lists of packages to add to the system profile.
29505 @cindex provenance tracking, of the operating system
29506 @defvr {Scheme Variable} provenance-service-type
29507 This is the type of the service that records @dfn{provenance meta-data}
29508 in the system itself. It creates several files under
29509 @file{/run/current-system}:
29513 This is a ``channel file'' that can be passed to @command{guix pull -C}
29514 or @command{guix time-machine -C}, and which describes the channels used
29515 to build the system, if that information was available
29516 (@pxref{Channels}).
29518 @item configuration.scm
29519 This is the file that was passed as the value for this
29520 @code{provenance-service-type} service. By default, @command{guix
29521 system reconfigure} automatically passes the OS configuration file it
29522 received on the command line.
29525 This contains the same information as the two other files but in a
29526 format that is more readily processable.
29529 In general, these two pieces of information (channels and configuration
29530 file) are enough to reproduce the operating system ``from source''.
29533 This information is necessary to rebuild your operating system, but it
29534 is not always sufficient. In particular, @file{configuration.scm}
29535 itself is insufficient if it is not self-contained---if it refers to
29536 external Guile modules or to extra files. If you want
29537 @file{configuration.scm} to be self-contained, we recommend that modules
29538 or files it refers to be part of a channel.
29540 Besides, provenance meta-data is ``silent'' in the sense that it does
29541 not change the bits contained in your system, @emph{except for the
29542 meta-data bits themselves}. Two different OS configurations or sets of
29543 channels can lead to the same system, bit-for-bit; when
29544 @code{provenance-service-type} is used, these two systems will have
29545 different meta-data and thus different store file names, which makes
29546 comparison less trivial.
29549 This service is automatically added to your operating system
29550 configuration when you use @command{guix system reconfigure},
29551 @command{guix system init}, or @command{guix deploy}.
29554 @node Shepherd Services
29555 @subsection Shepherd Services
29557 @cindex shepherd services
29559 @cindex init system
29560 The @code{(gnu services shepherd)} module provides a way to define
29561 services managed by the GNU@tie{}Shepherd, which is the
29562 initialization system---the first process that is started when the
29563 system boots, also known as PID@tie{}1
29564 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
29566 Services in the Shepherd can depend on each other. For instance, the
29567 SSH daemon may need to be started after the syslog daemon has been
29568 started, which in turn can only happen once all the file systems have
29569 been mounted. The simple operating system defined earlier (@pxref{Using
29570 the Configuration System}) results in a service graph like this:
29572 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
29574 You can actually generate such a graph for any operating system
29575 definition using the @command{guix system shepherd-graph} command
29576 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
29578 The @code{%shepherd-root-service} is a service object representing
29579 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
29580 by passing it lists of @code{<shepherd-service>} objects.
29582 @deftp {Data Type} shepherd-service
29583 The data type representing a service managed by the Shepherd.
29586 @item @code{provision}
29587 This is a list of symbols denoting what the service provides.
29589 These are the names that may be passed to @command{herd start},
29590 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
29591 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
29592 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
29594 @item @code{requirement} (default: @code{'()})
29595 List of symbols denoting the Shepherd services this one depends on.
29597 @cindex one-shot services, for the Shepherd
29598 @item @code{one-shot?} (default: @code{#f})
29599 Whether this service is @dfn{one-shot}. One-shot services stop immediately
29600 after their @code{start} action has completed. @xref{Slots of services,,,
29601 shepherd, The GNU Shepherd Manual}, for more info.
29603 @item @code{respawn?} (default: @code{#t})
29604 Whether to restart the service when it stops, for instance when the
29605 underlying process dies.
29608 @itemx @code{stop} (default: @code{#~(const #f)})
29609 The @code{start} and @code{stop} fields refer to the Shepherd's
29610 facilities to start and stop processes (@pxref{Service De- and
29611 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
29612 G-expressions that get expanded in the Shepherd configuration file
29613 (@pxref{G-Expressions}).
29615 @item @code{actions} (default: @code{'()})
29616 @cindex actions, of Shepherd services
29617 This is a list of @code{shepherd-action} objects (see below) defining
29618 @dfn{actions} supported by the service, in addition to the standard
29619 @code{start} and @code{stop} actions. Actions listed here become available as
29620 @command{herd} sub-commands:
29623 herd @var{action} @var{service} [@var{arguments}@dots{}]
29626 @item @code{auto-start?} (default: @code{#t})
29627 Whether this service should be started automatically by the Shepherd. If it
29628 is @code{#f} the service has to be started manually with @code{herd start}.
29630 @item @code{documentation}
29631 A documentation string, as shown when running:
29634 herd doc @var{service-name}
29637 where @var{service-name} is one of the symbols in @code{provision}
29638 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
29640 @item @code{modules} (default: @code{%default-modules})
29641 This is the list of modules that must be in scope when @code{start} and
29642 @code{stop} are evaluated.
29647 @deftp {Data Type} shepherd-action
29648 This is the data type that defines additional actions implemented by a
29649 Shepherd service (see above).
29653 Symbol naming the action.
29655 @item documentation
29656 This is a documentation string for the action. It can be viewed by running:
29659 herd doc @var{service} action @var{action}
29663 This should be a gexp that evaluates to a procedure of at least one argument,
29664 which is the ``running value'' of the service (@pxref{Slots of services,,,
29665 shepherd, The GNU Shepherd Manual}).
29668 The following example defines an action called @code{say-hello} that kindly
29674 (documentation "Say hi!")
29675 (procedure #~(lambda (running . args)
29676 (format #t "Hello, friend! arguments: ~s\n"
29681 Assuming this action is added to the @code{example} service, then you can do:
29684 # herd say-hello example
29685 Hello, friend! arguments: ()
29686 # herd say-hello example a b c
29687 Hello, friend! arguments: ("a" "b" "c")
29690 This, as you can see, is a fairly sophisticated way to say hello.
29691 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
29695 @defvr {Scheme Variable} shepherd-root-service-type
29696 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
29698 This is the service type that extensions target when they want to create
29699 shepherd services (@pxref{Service Types and Services}, for an example).
29700 Each extension must pass a list of @code{<shepherd-service>}.
29703 @defvr {Scheme Variable} %shepherd-root-service
29704 This service represents PID@tie{}1.
29708 @node Documentation
29709 @chapter Documentation
29711 @cindex documentation, searching for
29712 @cindex searching for documentation
29713 @cindex Info, documentation format
29715 @cindex manual pages
29716 In most cases packages installed with Guix come with documentation.
29717 There are two main documentation formats: ``Info'', a browseable
29718 hypertext format used for GNU software, and ``manual pages'' (or ``man
29719 pages''), the linear documentation format traditionally found on Unix.
29720 Info manuals are accessed with the @command{info} command or with Emacs,
29721 and man pages are accessed using @command{man}.
29723 You can look for documentation of software installed on your system by
29724 keyword. For example, the following command searches for information
29725 about ``TLS'' in Info manuals:
29729 "(emacs)Network Security" -- STARTTLS
29730 "(emacs)Network Security" -- TLS
29731 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
29732 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
29737 The command below searches for the same keyword in man pages:
29741 SSL (7) - OpenSSL SSL/TLS library
29742 certtool (1) - GnuTLS certificate tool
29746 These searches are purely local to your computer so you have the
29747 guarantee that documentation you find corresponds to what you have
29748 actually installed, you can access it off-line, and your privacy is
29751 Once you have these results, you can view the relevant documentation by
29755 $ info "(gnutls)Core TLS API"
29765 Info manuals contain sections and indices as well as hyperlinks like
29766 those found in Web pages. The @command{info} reader (@pxref{Top, Info
29767 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
29768 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
29769 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
29770 Introduction}, for an introduction to Info navigation.
29772 @node Installing Debugging Files
29773 @chapter Installing Debugging Files
29775 @cindex debugging files
29776 Program binaries, as produced by the GCC compilers for instance, are
29777 typically written in the ELF format, with a section containing
29778 @dfn{debugging information}. Debugging information is what allows the
29779 debugger, GDB, to map binary code to source code; it is required to
29780 debug a compiled program in good conditions.
29782 The problem with debugging information is that is takes up a fair amount
29783 of disk space. For example, debugging information for the GNU C Library
29784 weighs in at more than 60 MiB. Thus, as a user, keeping all the
29785 debugging info of all the installed programs is usually not an option.
29786 Yet, space savings should not come at the cost of an impediment to
29787 debugging---especially in the GNU system, which should make it easier
29788 for users to exert their computing freedom (@pxref{GNU Distribution}).
29790 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
29791 mechanism that allows users to get the best of both worlds: debugging
29792 information can be stripped from the binaries and stored in separate
29793 files. GDB is then able to load debugging information from those files,
29794 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
29797 The GNU distribution takes advantage of this by storing debugging
29798 information in the @code{lib/debug} sub-directory of a separate package
29799 output unimaginatively called @code{debug} (@pxref{Packages with
29800 Multiple Outputs}). Users can choose to install the @code{debug} output
29801 of a package when they need it. For instance, the following command
29802 installs the debugging information for the GNU C Library and for GNU
29806 guix install glibc:debug guile:debug
29809 GDB must then be told to look for debug files in the user's profile, by
29810 setting the @code{debug-file-directory} variable (consider setting it
29811 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
29815 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
29818 From there on, GDB will pick up debugging information from the
29819 @file{.debug} files under @file{~/.guix-profile/lib/debug}.
29821 In addition, you will most likely want GDB to be able to show the source
29822 code being debugged. To do that, you will have to unpack the source
29823 code of the package of interest (obtained with @code{guix build
29824 --source}, @pxref{Invoking guix build}), and to point GDB to that source
29825 directory using the @code{directory} command (@pxref{Source Path,
29826 @code{directory},, gdb, Debugging with GDB}).
29828 @c XXX: keep me up-to-date
29829 The @code{debug} output mechanism in Guix is implemented by the
29830 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
29831 opt-in---debugging information is available only for the packages
29832 with definitions explicitly declaring a @code{debug} output. This may be
29833 changed to opt-out in the future if our build farm servers can handle
29834 the load. To check whether a package has a @code{debug} output, use
29835 @command{guix package --list-available} (@pxref{Invoking guix package}).
29838 @node Security Updates
29839 @chapter Security Updates
29841 @cindex security updates
29842 @cindex security vulnerabilities
29843 Occasionally, important security vulnerabilities are discovered in software
29844 packages and must be patched. Guix developers try hard to keep track of
29845 known vulnerabilities and to apply fixes as soon as possible in the
29846 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
29847 containing only security updates). The @command{guix lint} tool helps
29848 developers find out about vulnerable versions of software packages in the
29853 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
29854 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
29855 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
29859 @xref{Invoking guix lint}, for more information.
29861 Guix follows a functional
29862 package management discipline (@pxref{Introduction}), which implies
29863 that, when a package is changed, @emph{every package that depends on it}
29864 must be rebuilt. This can significantly slow down the deployment of
29865 fixes in core packages such as libc or Bash, since basically the whole
29866 distribution would need to be rebuilt. Using pre-built binaries helps
29867 (@pxref{Substitutes}), but deployment may still take more time than
29871 To address this, Guix implements @dfn{grafts}, a mechanism that allows
29872 for fast deployment of critical updates without the costs associated
29873 with a whole-distribution rebuild. The idea is to rebuild only the
29874 package that needs to be patched, and then to ``graft'' it onto packages
29875 explicitly installed by the user and that were previously referring to
29876 the original package. The cost of grafting is typically very low, and
29877 order of magnitudes lower than a full rebuild of the dependency chain.
29879 @cindex replacements of packages, for grafts
29880 For instance, suppose a security update needs to be applied to Bash.
29881 Guix developers will provide a package definition for the ``fixed''
29882 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
29883 Packages}). Then, the original package definition is augmented with a
29884 @code{replacement} field pointing to the package containing the bug fix:
29891 (replacement bash-fixed)))
29894 From there on, any package depending directly or indirectly on Bash---as
29895 reported by @command{guix gc --requisites} (@pxref{Invoking guix
29896 gc})---that is installed is automatically ``rewritten'' to refer to
29897 @code{bash-fixed} instead of @code{bash}. This grafting process takes
29898 time proportional to the size of the package, usually less than a
29899 minute for an ``average'' package on a recent machine. Grafting is
29900 recursive: when an indirect dependency requires grafting, then grafting
29901 ``propagates'' up to the package that the user is installing.
29903 Currently, the length of the name and version of the graft and that of
29904 the package it replaces (@code{bash-fixed} and @code{bash} in the example
29905 above) must be equal. This restriction mostly comes from the fact that
29906 grafting works by patching files, including binary files, directly.
29907 Other restrictions may apply: for instance, when adding a graft to a
29908 package providing a shared library, the original shared library and its
29909 replacement must have the same @code{SONAME} and be binary-compatible.
29911 The @option{--no-grafts} command-line option allows you to forcefully
29912 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
29916 guix build bash --no-grafts
29920 returns the store file name of the original Bash, whereas:
29927 returns the store file name of the ``fixed'', replacement Bash. This
29928 allows you to distinguish between the two variants of Bash.
29930 To verify which Bash your whole profile refers to, you can run
29931 (@pxref{Invoking guix gc}):
29934 guix gc -R `readlink -f ~/.guix-profile` | grep bash
29938 @dots{} and compare the store file names that you get with those above.
29939 Likewise for a complete Guix system generation:
29942 guix gc -R `guix system build my-config.scm` | grep bash
29945 Lastly, to check which Bash running processes are using, you can use the
29946 @command{lsof} command:
29949 lsof | grep /gnu/store/.*bash
29953 @node Bootstrapping
29954 @chapter Bootstrapping
29956 @c Adapted from the ELS 2013 paper.
29958 @cindex bootstrapping
29960 Bootstrapping in our context refers to how the distribution gets built
29961 ``from nothing''. Remember that the build environment of a derivation
29962 contains nothing but its declared inputs (@pxref{Introduction}). So
29963 there's an obvious chicken-and-egg problem: how does the first package
29964 get built? How does the first compiler get compiled? Note that this is
29965 a question of interest only to the curious hacker, not to the regular
29966 user, so you can shamelessly skip this section if you consider yourself
29967 a ``regular user''.
29969 @cindex bootstrap binaries
29970 The GNU system is primarily made of C code, with libc at its core. The
29971 GNU build system itself assumes the availability of a Bourne shell and
29972 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
29973 `grep'. Furthermore, build programs---programs that run
29974 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
29975 (@pxref{Derivations}). Consequently, to be able to build anything at
29976 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
29977 Binutils, libc, and the other packages mentioned above---the
29978 @dfn{bootstrap binaries}.
29980 These bootstrap binaries are ``taken for granted'', though we can also
29981 re-create them if needed (@pxref{Preparing to Use the Bootstrap
29985 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
29986 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
29989 @node Reduced Binary Seed Bootstrap
29990 @section The Reduced Binary Seed Bootstrap
29992 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
29993 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
29994 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
29995 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
29996 ``taken for granted.''
29998 Taking the bootstrap binaries for granted means that we consider them to
29999 be a correct and trustworthy ``seed'' for building the complete system.
30000 Therein lies a problem: the combined size of these bootstrap binaries is
30001 about 250MB (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing
30002 or even inspecting these is next to impossible.
30004 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a
30005 ``Reduced Binary Seed'' bootstrap @footnote{We would like to say: ``Full
30006 Source Bootstrap'' and while we are working towards that goal it would
30007 be hyperbole to use that term for what we do now.}.
30009 The Reduced Binary Seed bootstrap removes the most critical tools---from a
30010 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
30011 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
30012 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
30013 written in Scheme and the Mes C Library, built for TinyCC and for GCC).
30015 Using these new binary seeds the ``missing'' Binutils, GCC, and the GNU
30016 C Library are built from source. From here on the more traditional
30017 bootstrap process resumes. This approach has reduced the bootstrap
30018 binaries in size to about 145MB in Guix v1.1.
30020 The next step that Guix has taken is to replace the shell and all its
30021 utilities with implementations in Guile Scheme, the @emph{Scheme-only
30022 bootstrap}. Gash (@pxref{Gash,,, gash, The Gash manual}) is a
30023 POSIX-compatible shell that replaces Bash, and it comes with Gash Utils
30024 which has minimalist replacements for Awk, the GNU Core Utilities, Grep,
30025 Gzip, Sed, and Tar. The rest of the bootstrap binary seeds that were
30026 removed are now built from source.
30028 Building the GNU System from source is currently only possibly by adding
30029 some historical GNU packages as intermediate steps@footnote{Packages
30030 such as @code{gcc-2.95.3}, @code{binutils-2.14}, @code{glibc-2.2.5},
30031 @code{gzip-1.2.4}, @code{tar-1.22}, and some others. For details, see
30032 @file{gnu/packages/commencement.scm}.}. As Gash and Gash Utils mature,
30033 and GNU packages become more bootstrappable again (e.g., new releases of
30034 GNU Sed will also ship as gzipped tarballs again, as alternative to the
30035 hard to bootstrap @code{xz}-compression), this set of added packages can
30036 hopefully be reduced again.
30038 The graph below shows the resulting dependency graph for
30039 @code{gcc-core-mesboot0}, the bootstrap compiler used for the
30040 traditional bootstrap of the rest of the Guix System.
30042 @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
30043 @image{images/gcc-core-mesboot0-graph,6in,,Dependency graph of gcc-core-mesboot0}
30045 The only significant binary bootstrap seeds that remain@footnote{
30046 Ignoring the 68KB @code{mescc-tools}; that will be removed later,
30047 together with @code{mes}.} are a Scheme intepreter and a Scheme
30048 compiler: GNU Mes and GNU Guile@footnote{Not shown in this graph are the
30049 static binaries for @file{bash}, @code{tar}, and @code{xz} that are used
30050 to get Guile running.}.
30052 This further reduction has brought down the size of the binary seed to
30053 about 60MB for @code{i686-linux} and @code{x86_64-linux}.
30055 Work is ongoing to remove all binary blobs from our free software
30056 bootstrap stack, working towards a Full Source Bootstrap. Also ongoing
30057 is work to bring these bootstraps to the @code{arm-linux} and
30058 @code{aarch64-linux} architectures and to the Hurd.
30060 If you are interested, join us on @samp{#bootstrappable} on the Freenode
30061 IRC network or discuss on @email{bug-mes@@gnu.org} or
30062 @email{gash-devel@@nongnu.org}.
30064 @node Preparing to Use the Bootstrap Binaries
30065 @section Preparing to Use the Bootstrap Binaries
30067 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
30068 @c large image, it's hard to scroll. Oh well.
30069 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
30071 The figure above shows the very beginning of the dependency graph of the
30072 distribution, corresponding to the package definitions of the @code{(gnu
30073 packages bootstrap)} module. A similar figure can be generated with
30074 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
30077 guix graph -t derivation \
30078 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
30079 | dot -Tps > gcc.ps
30082 or, for the further Reduced Binary Seed bootstrap
30085 guix graph -t derivation \
30086 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
30087 | dot -Tps > mes.ps
30090 At this level of detail, things are
30091 slightly complex. First, Guile itself consists of an ELF executable,
30092 along with many source and compiled Scheme files that are dynamically
30093 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
30094 tarball shown in this graph. This tarball is part of Guix's ``source''
30095 distribution, and gets inserted into the store with @code{add-to-store}
30096 (@pxref{The Store}).
30098 But how do we write a derivation that unpacks this tarball and adds it
30099 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
30100 derivation---the first one that gets built---uses @code{bash} as its
30101 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
30102 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
30103 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
30104 the Guix source distribution, whose sole purpose is to allow the Guile
30105 tarball to be unpacked.
30107 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
30108 Guile that can be used to run subsequent build programs. Its first task
30109 is to download tarballs containing the other pre-built binaries---this
30110 is what the @file{.tar.xz.drv} derivations do. Guix modules such as
30111 @code{ftp-client.scm} are used for this purpose. The
30112 @code{module-import.drv} derivations import those modules in a directory
30113 in the store, using the original layout. The
30114 @code{module-import-compiled.drv} derivations compile those modules, and
30115 write them in an output directory with the right layout. This
30116 corresponds to the @code{#:modules} argument of
30117 @code{build-expression->derivation} (@pxref{Derivations}).
30119 Finally, the various tarballs are unpacked by the derivations
30120 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
30121 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
30122 point we have a working C tool chain.
30124 @unnumberedsec Building the Build Tools
30126 Bootstrapping is complete when we have a full tool chain that does not
30127 depend on the pre-built bootstrap tools discussed above. This
30128 no-dependency requirement is verified by checking whether the files of
30129 the final tool chain contain references to the @file{/gnu/store}
30130 directories of the bootstrap inputs. The process that leads to this
30131 ``final'' tool chain is described by the package definitions found in
30132 the @code{(gnu packages commencement)} module.
30134 The @command{guix graph} command allows us to ``zoom out'' compared to
30135 the graph above, by looking at the level of package objects instead of
30136 individual derivations---remember that a package may translate to
30137 several derivations, typically one derivation to download its source,
30138 one to build the Guile modules it needs, and one to actually build the
30139 package from source. The command:
30142 guix graph -t bag \
30143 -e '(@@@@ (gnu packages commencement)
30144 glibc-final-with-bootstrap-bash)' | xdot -
30148 displays the dependency graph leading to the ``final'' C
30149 library@footnote{You may notice the @code{glibc-intermediate} label,
30150 suggesting that it is not @emph{quite} final, but as a good
30151 approximation, we will consider it final.}, depicted below.
30153 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
30155 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
30156 The first tool that gets built with the bootstrap binaries is
30157 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
30158 for all the following packages. From there Findutils and Diffutils get
30161 Then come the first-stage Binutils and GCC, built as pseudo cross
30162 tools---i.e., with @option{--target} equal to @option{--host}. They are
30163 used to build libc. Thanks to this cross-build trick, this libc is
30164 guaranteed not to hold any reference to the initial tool chain.
30166 From there the final Binutils and GCC (not shown above) are built. GCC
30167 uses @command{ld} from the final Binutils, and links programs against
30168 the just-built libc. This tool chain is used to build the other
30169 packages used by Guix and by the GNU Build System: Guile, Bash,
30172 And voilà! At this point we have the complete set of build tools that
30173 the GNU Build System expects. These are in the @code{%final-inputs}
30174 variable of the @code{(gnu packages commencement)} module, and are
30175 implicitly used by any package that uses @code{gnu-build-system}
30176 (@pxref{Build Systems, @code{gnu-build-system}}).
30179 @unnumberedsec Building the Bootstrap Binaries
30181 @cindex bootstrap binaries
30182 Because the final tool chain does not depend on the bootstrap binaries,
30183 those rarely need to be updated. Nevertheless, it is useful to have an
30184 automated way to produce them, should an update occur, and this is what
30185 the @code{(gnu packages make-bootstrap)} module provides.
30187 The following command builds the tarballs containing the bootstrap binaries
30188 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
30189 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
30190 and Guile, and a tarball containing a mixture of Coreutils and other basic
30191 command-line tools):
30194 guix build bootstrap-tarballs
30197 The generated tarballs are those that should be referred to in the
30198 @code{(gnu packages bootstrap)} module mentioned at the beginning of
30201 Still here? Then perhaps by now you've started to wonder: when do we
30202 reach a fixed point? That is an interesting question! The answer is
30203 unknown, but if you would like to investigate further (and have
30204 significant computational and storage resources to do so), then let us
30207 @unnumberedsec Reducing the Set of Bootstrap Binaries
30209 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
30210 binary code! Why is that a problem? It's a problem because these big chunks
30211 of binary code are practically non-auditable, which makes it hard to establish
30212 what source code produced them. Every unauditable binary also leaves us
30213 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
30214 paper @emph{Reflections on Trusting Trust}.
30216 This is mitigated by the fact that our bootstrap binaries were generated
30217 from an earlier Guix revision. Nevertheless it lacks the level of
30218 transparency that we get in the rest of the package dependency graph,
30219 where Guix always gives us a source-to-binary mapping. Thus, our goal
30220 is to reduce the set of bootstrap binaries to the bare minimum.
30222 The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
30223 on-going projects to do that. One of these is about replacing the
30224 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
30225 of increasing complexity, which could be built from source starting from
30226 a simple and auditable assembler.
30228 Our first major achievement is the replacement of of GCC, the GNU C Library
30229 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
30230 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
30231 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
30232 bootstrapped yet and thus we inject them as binary seeds. We call this the
30233 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
30234 binaries! Also, it has eliminated the C compiler binary; i686-linux and
30235 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
30237 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
30238 also looking at any other bootstrap binaries. Your help is welcome!
30241 @chapter Porting to a New Platform
30243 As discussed above, the GNU distribution is self-contained, and
30244 self-containment is achieved by relying on pre-built ``bootstrap
30245 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
30246 operating system kernel, CPU architecture, and application binary
30247 interface (ABI). Thus, to port the distribution to a platform that is
30248 not yet supported, one must build those bootstrap binaries, and update
30249 the @code{(gnu packages bootstrap)} module to use them on that platform.
30251 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
30252 When everything goes well, and assuming the GNU tool chain supports the
30253 target platform, this can be as simple as running a command like this
30257 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
30260 For this to work, the @code{glibc-dynamic-linker} procedure in
30261 @code{(gnu packages bootstrap)} must be augmented to return the right
30262 file name for libc's dynamic linker on that platform; likewise,
30263 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
30264 taught about the new platform.
30266 Once these are built, the @code{(gnu packages bootstrap)} module needs
30267 to be updated to refer to these binaries on the target platform. That
30268 is, the hashes and URLs of the bootstrap tarballs for the new platform
30269 must be added alongside those of the currently supported platforms. The
30270 bootstrap Guile tarball is treated specially: it is expected to be
30271 available locally, and @file{gnu/local.mk} has rules to download it for
30272 the supported architectures; a rule for the new platform must be added
30275 In practice, there may be some complications. First, it may be that the
30276 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
30277 above) is not recognized by all the GNU tools. Typically, glibc
30278 recognizes some of these, whereas GCC uses an extra @option{--with-abi}
30279 configure flag (see @code{gcc.scm} for examples of how to handle this).
30280 Second, some of the required packages could fail to build for that
30281 platform. Lastly, the generated binaries could be broken for some
30284 @c *********************************************************************
30285 @include contributing.texi
30287 @c *********************************************************************
30288 @node Acknowledgments
30289 @chapter Acknowledgments
30291 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
30292 which was designed and
30293 implemented by Eelco Dolstra, with contributions from other people (see
30294 the @file{nix/AUTHORS} file in Guix). Nix pioneered functional package
30295 management, and promoted unprecedented features, such as transactional
30296 package upgrades and rollbacks, per-user profiles, and referentially
30297 transparent build processes. Without this work, Guix would not exist.
30299 The Nix-based software distributions, Nixpkgs and NixOS, have also been
30300 an inspiration for Guix.
30302 GNU@tie{}Guix itself is a collective work with contributions from a
30303 number of people. See the @file{AUTHORS} file in Guix for more
30304 information on these fine people. The @file{THANKS} file lists people
30305 who have helped by reporting bugs, taking care of the infrastructure,
30306 providing artwork and themes, making suggestions, and more---thank you!
30309 @c *********************************************************************
30310 @node GNU Free Documentation License
30311 @appendix GNU Free Documentation License
30312 @cindex license, GNU Free Documentation License
30313 @include fdl-1.3.texi
30315 @c *********************************************************************
30316 @node Concept Index
30317 @unnumbered Concept Index
30320 @node Programming Index
30321 @unnumbered Programming Index
30322 @syncodeindex tp fn
30323 @syncodeindex vr fn
30328 @c Local Variables:
30329 @c ispell-local-dictionary: "american";