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, 2020 Mathieu Othacehe@*
44 Copyright @copyright{} 2017 Federico Beffa@*
45 Copyright @copyright{} 2017, 2018 Carlo Zancanaro@*
46 Copyright @copyright{} 2017 Thomas Danckaert@*
47 Copyright @copyright{} 2017 humanitiesNerd@*
48 Copyright @copyright{} 2017 Christopher Allan Webber@*
49 Copyright @copyright{} 2017, 2018, 2019, 2020 Marius Bakke@*
50 Copyright @copyright{} 2017, 2019, 2020 Hartmut Goebel@*
51 Copyright @copyright{} 2017, 2019, 2020 Maxim Cournoyer@*
52 Copyright @copyright{} 2017, 2018, 2019, 2020 Tobias Geerinckx-Rice@*
53 Copyright @copyright{} 2017 George Clemmer@*
54 Copyright @copyright{} 2017 Andy Wingo@*
55 Copyright @copyright{} 2017, 2018, 2019, 2020 Arun Isaac@*
56 Copyright @copyright{} 2017 nee@*
57 Copyright @copyright{} 2018 Rutger Helling@*
58 Copyright @copyright{} 2018 Oleg Pykhalov@*
59 Copyright @copyright{} 2018 Mike Gerwitz@*
60 Copyright @copyright{} 2018 Pierre-Antoine Rouby@*
61 Copyright @copyright{} 2018, 2019 Gábor Boskovits@*
62 Copyright @copyright{} 2018, 2019, 2020 Florian Pelz@*
63 Copyright @copyright{} 2018 Laura Lazzati@*
64 Copyright @copyright{} 2018 Alex Vong@*
65 Copyright @copyright{} 2019 Josh Holland@*
66 Copyright @copyright{} 2019, 2020 Diego Nicola Barbato@*
67 Copyright @copyright{} 2019 Ivan Petkov@*
68 Copyright @copyright{} 2019 Jakob L. Kreuze@*
69 Copyright @copyright{} 2019 Kyle Andrews@*
70 Copyright @copyright{} 2019 Alex Griffin@*
71 Copyright @copyright{} 2019, 2020 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@*
83 Copyright @copyright{} 2020 André Batista@*
84 Copyright @copyright{} 2020 Alexandru-Sergiu Marton@*
85 Copyright @copyright{} 2020 raingloom@*
86 Copyright @copyright{} 2020 Daniel Brooks@*
88 Permission is granted to copy, distribute and/or modify this document
89 under the terms of the GNU Free Documentation License, Version 1.3 or
90 any later version published by the Free Software Foundation; with no
91 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
92 copy of the license is included in the section entitled ``GNU Free
93 Documentation License''.
96 @dircategory System administration
98 * Guix: (guix). Manage installed software and system configuration.
99 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
100 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
101 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
102 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
103 * guix deploy: (guix)Invoking guix deploy. Manage operating system configurations for remote hosts.
106 @dircategory Software development
108 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
109 * guix build: (guix)Invoking guix build. Building packages.
110 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
114 @title GNU Guix Reference Manual
115 @subtitle Using the GNU Guix Functional Package Manager
116 @author The GNU Guix Developers
119 @vskip 0pt plus 1filll
120 Edition @value{EDITION} @*
128 @c *********************************************************************
132 This document describes GNU Guix version @value{VERSION}, a functional
133 package management tool written for the GNU system.
135 @c TRANSLATORS: You can replace the following paragraph with information on
136 @c how to join your own translation team and how to report issues with the
138 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
139 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
140 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
141 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
142 Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
143 would like to translate it in your native language, consider joining the
144 @uref{https://translationproject.org/domain/guix-manual.html, Translation
148 * Introduction:: What is Guix about?
149 * Installation:: Installing Guix.
150 * System Installation:: Installing the whole operating system.
151 * Getting Started:: Your first steps.
152 * Package Management:: Package installation, upgrade, etc.
153 * Channels:: Customizing the package collection.
154 * Development:: Guix-aided software development.
155 * Programming Interface:: Using Guix in Scheme.
156 * Utilities:: Package management commands.
157 * System Configuration:: Configuring the operating system.
158 * Documentation:: Browsing software user manuals.
159 * Installing Debugging Files:: Feeding the debugger.
160 * Security Updates:: Deploying security fixes quickly.
161 * Bootstrapping:: GNU/Linux built from scratch.
162 * Porting:: Targeting another platform or kernel.
163 * Contributing:: Your help needed!
165 * Acknowledgments:: Thanks!
166 * GNU Free Documentation License:: The license of this manual.
167 * Concept Index:: Concepts.
168 * Programming Index:: Data types, functions, and variables.
171 --- The Detailed Node Listing ---
175 * Managing Software the Guix Way:: What's special.
176 * GNU Distribution:: The packages and tools.
180 * Binary Installation:: Getting Guix running in no time!
181 * Requirements:: Software needed to build and run Guix.
182 * Running the Test Suite:: Testing Guix.
183 * Setting Up the Daemon:: Preparing the build daemon's environment.
184 * Invoking guix-daemon:: Running the build daemon.
185 * Application Setup:: Application-specific setup.
186 * Upgrading Guix:: Upgrading Guix and its build daemon.
188 Setting Up the Daemon
190 * Build Environment Setup:: Preparing the isolated build environment.
191 * Daemon Offload Setup:: Offloading builds to remote machines.
192 * SELinux Support:: Using an SELinux policy for the daemon.
196 * Limitations:: What you can expect.
197 * Hardware Considerations:: Supported hardware.
198 * USB Stick and DVD Installation:: Preparing the installation medium.
199 * Preparing for Installation:: Networking, partitioning, etc.
200 * Guided Graphical Installation:: Easy graphical installation.
201 * Manual Installation:: Manual installation for wizards.
202 * After System Installation:: When installation succeeded.
203 * Installing Guix in a VM:: Guix System playground.
204 * Building the Installation Image:: How this comes to be.
208 * Keyboard Layout and Networking and Partitioning:: Initial setup.
209 * Proceeding with the Installation:: Installing.
213 * Features:: How Guix will make your life brighter.
214 * Invoking guix package:: Package installation, removal, etc.
215 * Substitutes:: Downloading pre-built binaries.
216 * Packages with Multiple Outputs:: Single source package, multiple outputs.
217 * Invoking guix gc:: Running the garbage collector.
218 * Invoking guix pull:: Fetching the latest Guix and distribution.
219 * Invoking guix time-machine:: Running an older revision of Guix.
220 * Inferiors:: Interacting with another revision of Guix.
221 * Invoking guix describe:: Display information about your Guix revision.
222 * Invoking guix archive:: Exporting and importing store files.
226 * Official Substitute Server:: One particular source of substitutes.
227 * Substitute Server Authorization:: How to enable or disable substitutes.
228 * Getting Substitutes from Other Servers:: Substitute diversity.
229 * Substitute Authentication:: How Guix verifies substitutes.
230 * Proxy Settings:: How to get substitutes via proxy.
231 * Substitution Failure:: What happens when substitution fails.
232 * On Trusting Binaries:: How can you trust that binary blob?
236 * Specifying Additional Channels:: Extending the package collection.
237 * Using a Custom Guix Channel:: Using a customized Guix.
238 * Replicating Guix:: Running the @emph{exact same} Guix.
239 * Channel Authentication:: How Guix verifies what it fetches.
240 * Creating a Channel:: How to write your custom channel.
241 * Package Modules in a Sub-directory:: Specifying the channel's package modules location.
242 * Declaring Channel Dependencies:: How to depend on other channels.
243 * Specifying Channel Authorizations:: Defining channel authors authorizations.
244 * Primary URL:: Distinguishing mirror to original.
245 * Writing Channel News:: Communicating information to channel's users.
249 * Invoking guix environment:: Setting up development environments.
250 * Invoking guix pack:: Creating software bundles.
251 * The GCC toolchain:: Working with languages supported by GCC.
252 * Invoking guix git authenticate:: Authenticating Git repositories.
254 Programming Interface
256 * Package Modules:: Packages from the programmer's viewpoint.
257 * Defining Packages:: Defining new packages.
258 * Defining Package Variants:: Customizing packages.
259 * Build Systems:: Specifying how packages are built.
260 * Build Phases:: Phases of the build process of a package.
261 * Build Utilities:: Helpers for your package definitions and more.
262 * The Store:: Manipulating the package store.
263 * Derivations:: Low-level interface to package derivations.
264 * The Store Monad:: Purely functional interface to the store.
265 * G-Expressions:: Manipulating build expressions.
266 * Invoking guix repl:: Programming Guix in Guile.
270 * package Reference:: The package data type.
271 * origin Reference:: The origin data type.
275 * Invoking guix build:: Building packages from the command line.
276 * Invoking guix edit:: Editing package definitions.
277 * Invoking guix download:: Downloading a file and printing its hash.
278 * Invoking guix hash:: Computing the cryptographic hash of a file.
279 * Invoking guix import:: Importing package definitions.
280 * Invoking guix refresh:: Updating package definitions.
281 * Invoking guix lint:: Finding errors in package definitions.
282 * Invoking guix size:: Profiling disk usage.
283 * Invoking guix graph:: Visualizing the graph of packages.
284 * Invoking guix publish:: Sharing substitutes.
285 * Invoking guix challenge:: Challenging substitute servers.
286 * Invoking guix copy:: Copying to and from a remote store.
287 * Invoking guix container:: Process isolation.
288 * Invoking guix weather:: Assessing substitute availability.
289 * Invoking guix processes:: Listing client processes.
291 Invoking @command{guix build}
293 * Common Build Options:: Build options for most commands.
294 * Package Transformation Options:: Creating variants of packages.
295 * Additional Build Options:: Options specific to 'guix build'.
296 * Debugging Build Failures:: Real life packaging experience.
300 * Using the Configuration System:: Customizing your GNU system.
301 * operating-system Reference:: Detail of operating-system declarations.
302 * File Systems:: Configuring file system mounts.
303 * Mapped Devices:: Block device extra processing.
304 * User Accounts:: Specifying user accounts.
305 * Keyboard Layout:: How the system interprets key strokes.
306 * Locales:: Language and cultural convention settings.
307 * Services:: Specifying system services.
308 * Setuid Programs:: Programs running with root privileges.
309 * X.509 Certificates:: Authenticating HTTPS servers.
310 * Name Service Switch:: Configuring libc's name service switch.
311 * Initial RAM Disk:: Linux-Libre bootstrapping.
312 * Bootloader Configuration:: Configuring the boot loader.
313 * Invoking guix system:: Instantiating a system configuration.
314 * Invoking guix deploy:: Deploying a system configuration to a remote host.
315 * Running Guix in a VM:: How to run Guix System in a virtual machine.
316 * Defining Services:: Adding new service definitions.
320 * Base Services:: Essential system services.
321 * Scheduled Job Execution:: The mcron service.
322 * Log Rotation:: The rottlog service.
323 * Networking Services:: Network setup, SSH daemon, etc.
324 * Unattended Upgrades:: Automated system upgrades.
325 * X Window:: Graphical display.
326 * Printing Services:: Local and remote printer support.
327 * Desktop Services:: D-Bus and desktop services.
328 * Sound Services:: ALSA and Pulseaudio services.
329 * Database Services:: SQL databases, key-value stores, etc.
330 * Mail Services:: IMAP, POP3, SMTP, and all that.
331 * Messaging Services:: Messaging services.
332 * Telephony Services:: Telephony services.
333 * Monitoring Services:: Monitoring services.
334 * Kerberos Services:: Kerberos services.
335 * LDAP Services:: LDAP services.
336 * Web Services:: Web servers.
337 * Certificate Services:: TLS certificates via Let's Encrypt.
338 * DNS Services:: DNS daemons.
339 * VPN Services:: VPN daemons.
340 * Network File System:: NFS related services.
341 * Continuous Integration:: The Cuirass service.
342 * Power Management Services:: Extending battery life.
343 * Audio Services:: The MPD.
344 * Virtualization Services:: Virtualization services.
345 * Version Control Services:: Providing remote access to Git repositories.
346 * Game Services:: Game servers.
347 * PAM Mount Service:: Service to mount volumes when logging in.
348 * Guix Services:: Services relating specifically to Guix.
349 * Linux Services:: Services tied to the Linux kernel.
350 * Hurd Services:: Services specific for a Hurd System.
351 * Miscellaneous Services:: Other services.
355 * Service Composition:: The model for composing services.
356 * Service Types and Services:: Types and services.
357 * Service Reference:: API reference.
358 * Shepherd Services:: A particular type of service.
360 Installing Debugging Files
362 * Separate Debug Info:: Installing 'debug' outputs.
363 * Rebuilding Debug Info:: Building missing debug info.
367 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
368 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
373 @c *********************************************************************
375 @chapter Introduction
378 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
379 using the international phonetic alphabet (IPA).} is a package
380 management tool for and distribution of the GNU system.
381 Guix makes it easy for unprivileged
382 users to install, upgrade, or remove software packages, to roll back to a
383 previous package set, to build packages from source, and generally
384 assists with the creation and maintenance of software environments.
387 @cindex GuixSD, now Guix System
388 @cindex Guix System Distribution, now Guix System
389 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
390 complements the available tools without interference (@pxref{Installation}),
391 or you can use it as a standalone operating system distribution,
392 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
393 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
394 group everything under the ``Guix'' banner since, after all, Guix System is
395 readily available through the @command{guix system} command, even if you're
396 using a different distro underneath!}. @xref{GNU Distribution}.
399 * Managing Software the Guix Way:: What's special.
400 * GNU Distribution:: The packages and tools.
403 @node Managing Software the Guix Way
404 @section Managing Software the Guix Way
406 @cindex user interfaces
407 Guix provides a command-line package management interface
408 (@pxref{Package Management}), tools to help with software development
409 (@pxref{Development}), command-line utilities for more advanced usage
410 (@pxref{Utilities}), as well as Scheme programming interfaces
411 (@pxref{Programming Interface}).
413 Its @dfn{build daemon} is responsible for building packages on behalf of
414 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
415 binaries from authorized sources (@pxref{Substitutes}).
417 @cindex extensibility of the distribution
418 @cindex customization, of packages
419 Guix includes package definitions for many GNU and non-GNU packages, all
420 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
421 user's computing freedom}. It is @emph{extensible}: users can write
422 their own package definitions (@pxref{Defining Packages}) and make them
423 available as independent package modules (@pxref{Package Modules}). It
424 is also @emph{customizable}: users can @emph{derive} specialized package
425 definitions from existing ones, including from the command line
426 (@pxref{Package Transformation Options}).
428 @cindex functional package management
430 Under the hood, Guix implements the @dfn{functional package management}
431 discipline pioneered by Nix (@pxref{Acknowledgments}).
432 In Guix, the package build and installation process is seen
433 as a @emph{function}, in the mathematical sense. That function takes inputs,
434 such as build scripts, a compiler, and libraries, and
435 returns an installed package. As a pure function, its result depends
436 solely on its inputs---for instance, it cannot refer to software or
437 scripts that were not explicitly passed as inputs. A build function
438 always produces the same result when passed a given set of inputs. It
439 cannot alter the environment of the running system in
440 any way; for instance, it cannot create, modify, or delete files outside
441 of its build and installation directories. This is achieved by running
442 build processes in isolated environments (or @dfn{containers}), where only their
443 explicit inputs are visible.
446 The result of package build functions is @dfn{cached} in the file
447 system, in a special directory called @dfn{the store} (@pxref{The
448 Store}). Each package is installed in a directory of its own in the
449 store---by default under @file{/gnu/store}. The directory name contains
450 a hash of all the inputs used to build that package; thus, changing an
451 input yields a different directory name.
453 This approach is the foundation for the salient features of Guix: support
454 for transactional package upgrade and rollback, per-user installation, and
455 garbage collection of packages (@pxref{Features}).
458 @node GNU Distribution
459 @section GNU Distribution
462 Guix comes with a distribution of the GNU system consisting entirely of
463 free software@footnote{The term ``free'' here refers to the
464 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
465 users of that software}.}. The
466 distribution can be installed on its own (@pxref{System Installation}),
467 but it is also possible to install Guix as a package manager on top of
468 an installed GNU/Linux system (@pxref{Installation}). When we need to
469 distinguish between the two, we refer to the standalone distribution as
472 The distribution provides core GNU packages such as GNU libc, GCC, and
473 Binutils, as well as many GNU and non-GNU applications. The complete
474 list of available packages can be browsed
475 @url{https://www.gnu.org/software/guix/packages,on-line} or by
476 running @command{guix package} (@pxref{Invoking guix package}):
479 guix package --list-available
482 Our goal is to provide a practical 100% free software distribution of
483 Linux-based and other variants of GNU, with a focus on the promotion and
484 tight integration of GNU components, and an emphasis on programs and
485 tools that help users exert that freedom.
487 Packages are currently available on the following platforms:
492 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel.
495 Intel 32-bit architecture (IA32), Linux-Libre kernel.
498 ARMv7-A architecture with hard float, Thumb-2 and NEON,
499 using the EABI hard-float application binary interface (ABI),
500 and Linux-Libre kernel.
503 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
506 @uref{https://hurd.gnu.org, GNU/Hurd} on the Intel 32-bit architecture
509 This configuration is experimental and under development. The easiest
510 way for you to give it a try is by setting up an instance of
511 @code{hurd-vm-service-type} on your GNU/Linux machine
512 (@pxref{transparent-emulation-qemu, @code{hurd-vm-service-type}}).
513 @xref{Contributing}, on how to help!
515 @item mips64el-linux (deprecated)
516 little-endian 64-bit MIPS processors, specifically the Loongson series,
517 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
518 supported; in particular, there is no ongoing work to ensure that this
519 architecture still works. Should someone decide they wish to revive this
520 architecture then the code is still available.
524 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
525 configuration and Guix takes care of instantiating the configuration in a
526 transactional, reproducible, and stateless fashion (@pxref{System
527 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
528 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
529 Manual}), the well-known GNU utilities and tool chain, as well as the
530 graphical environment or system services of your choice.
532 Guix System is available on all the above platforms except
533 @code{mips64el-linux}.
536 For information on porting to other architectures or kernels,
539 Building this distribution is a cooperative effort, and you are invited
540 to join! @xref{Contributing}, for information about how you can help.
543 @c *********************************************************************
545 @chapter Installation
547 @cindex installing Guix
550 We recommend the use of this
551 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
552 shell installer script} to install Guix on top of a running GNU/Linux system,
553 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
554 with the installation of the package manager, which can be done on top of a
555 running GNU/Linux system. If, instead, you want to install the complete GNU
556 operating system, @pxref{System Installation}.} The script automates the
557 download, installation, and initial configuration of Guix. It should be run
561 @cindex foreign distro
562 @cindex directories related to foreign distro
563 When installed on a foreign distro, GNU@tie{}Guix complements the available
564 tools without interference. Its data lives exclusively in two directories,
565 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
566 such as @file{/etc}, are left untouched.
568 Once installed, Guix can be updated by running @command{guix pull}
569 (@pxref{Invoking guix pull}).
571 If you prefer to perform the installation steps manually or want to tweak
572 them, you may find the following subsections useful. They describe the
573 software requirements of Guix, as well as how to install it manually and get
577 * Binary Installation:: Getting Guix running in no time!
578 * Requirements:: Software needed to build and run Guix.
579 * Running the Test Suite:: Testing Guix.
580 * Setting Up the Daemon:: Preparing the build daemon's environment.
581 * Invoking guix-daemon:: Running the build daemon.
582 * Application Setup:: Application-specific setup.
583 * Upgrading Guix:: Upgrading Guix and its build daemon.
586 @node Binary Installation
587 @section Binary Installation
589 @cindex installing Guix from binaries
590 @cindex installer script
591 This section describes how to install Guix on an arbitrary system from a
592 self-contained tarball providing binaries for Guix and for all its
593 dependencies. This is often quicker than installing from source, which
594 is described in the next sections. The only requirement is to have
597 @c Note duplicated from the ``Installation'' node.
599 We recommend the use of this
600 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
601 shell installer script}. The script automates the download, installation, and
602 initial configuration steps described below. It should be run as the root
603 user. As root, you can thus run this:
607 wget https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh
608 chmod +x guix-install.sh
612 When you're done, @pxref{Application Setup} for extra configuration you
613 might need, and @ref{Getting Started} for your first steps!
616 Installing goes along these lines:
620 @cindex downloading Guix binary
621 Download the binary tarball from
622 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz},
623 where @code{x86_64-linux} can be replaced with @code{i686-linux} for an
624 @code{i686} (32-bits) machine already running the kernel Linux, and so on
625 (@pxref{GNU Distribution}).
627 @c The following is somewhat duplicated in ``System Installation''.
628 Make sure to download the associated @file{.sig} file and to verify the
629 authenticity of the tarball against it, along these lines:
632 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
633 $ gpg --verify guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
636 If that command fails because you do not have the required public key,
637 then run this command to import it:
640 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
641 -qO - | gpg --import -
645 and rerun the @code{gpg --verify} command.
647 Take note that a warning like ``This key is not certified with a trusted
648 signature!'' is normal.
650 @c end authentication part
653 Now, you need to become the @code{root} user. Depending on your distribution,
654 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
658 # tar --warning=no-timestamp -xf \
659 /path/to/guix-binary-@value{VERSION}.x86_64-linux.tar.xz
660 # mv var/guix /var/ && mv gnu /
663 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
664 The latter contains a ready-to-use profile for @code{root} (see next
667 Do @emph{not} unpack the tarball on a working Guix system since that
668 would overwrite its own essential files.
670 The @option{--warning=no-timestamp} option makes sure GNU@tie{}tar does
671 not emit warnings about ``implausibly old time stamps'' (such
672 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
674 They stem from the fact that all the
675 files in the archive have their modification time set to 1 (which
676 means January 1st, 1970). This is done on purpose to make sure the
677 archive content is independent of its creation time, thus making it
681 Make the profile available under @file{~root/.config/guix/current}, which is
682 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
685 # mkdir -p ~root/.config/guix
686 # ln -sf /var/guix/profiles/per-user/root/current-guix \
687 ~root/.config/guix/current
690 Source @file{etc/profile} to augment @env{PATH} and other relevant
691 environment variables:
694 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
695 source $GUIX_PROFILE/etc/profile
699 Create the group and user accounts for build users as explained below
700 (@pxref{Build Environment Setup}).
703 Run the daemon, and set it to automatically start on boot.
705 If your host distro uses the systemd init system, this can be achieved
708 @c Versions of systemd that supported symlinked service files are not
709 @c yet widely deployed, so we should suggest that users copy the service
712 @c See this thread for more information:
713 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
716 # cp ~root/.config/guix/current/lib/systemd/system/gnu-store.mount \
717 ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
719 # systemctl enable --now gnu-store.mount guix-daemon
722 If your host distro uses the Upstart init system:
725 # initctl reload-configuration
726 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
731 Otherwise, you can still start the daemon manually with:
734 # ~root/.config/guix/current/bin/guix-daemon \
735 --build-users-group=guixbuild
739 Make the @command{guix} command available to other users on the machine,
743 # mkdir -p /usr/local/bin
745 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
748 It is also a good idea to make the Info version of this manual available
752 # mkdir -p /usr/local/share/info
753 # cd /usr/local/share/info
754 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
758 That way, assuming @file{/usr/local/share/info} is in the search path,
759 running @command{info guix} will open this manual (@pxref{Other Info
760 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
764 @cindex substitutes, authorization thereof
765 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
766 (@pxref{Substitutes}), authorize them:
769 # guix archive --authorize < \
770 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
774 Each user may need to perform a few additional steps to make their Guix
775 environment ready for use, @pxref{Application Setup}.
778 Voilà, the installation is complete!
780 You can confirm that Guix is working by installing a sample package into
787 The binary installation tarball can be (re)produced and verified simply
788 by running the following command in the Guix source tree:
791 make guix-binary.@var{system}.tar.xz
795 ...@: which, in turn, runs:
798 guix pack -s @var{system} --localstatedir \
799 --profile-name=current-guix guix
802 @xref{Invoking guix pack}, for more info on this handy tool.
805 @section Requirements
807 This section lists requirements when building Guix from source. The
808 build procedure for Guix is the same as for other GNU software, and is
809 not covered here. Please see the files @file{README} and @file{INSTALL}
810 in the Guix source tree for additional details.
812 @cindex official website
813 GNU Guix is available for download from its website at
814 @url{https://www.gnu.org/software/guix/}.
816 GNU Guix depends on the following packages:
819 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 3.0.x or
821 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
824 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
825 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
826 Guile,, gnutls-guile, GnuTLS-Guile});
828 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
830 @item @uref{https://notabug.org/guile-zlib/guile-zlib, Guile-zlib};
831 @item @uref{https://notabug.org/guile-lzlib/guile-lzlib, Guile-lzlib};
832 @item @uref{https://www.nongnu.org/guile-avahi/, Guile-Avahi};
834 @c FIXME: Specify a version number once a release has been made.
835 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, version 0.3.0
837 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON}
839 @item @url{https://www.gnu.org/software/make/, GNU Make}.
842 The following dependencies are optional:
846 @c Note: We need at least 0.13.0 for #:nodelay.
847 Support for build offloading (@pxref{Daemon Offload Setup}) and
848 @command{guix copy} (@pxref{Invoking guix copy}) depends on
849 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
850 version 0.13.0 or later.
853 When @url{http://www.bzip.org, libbz2} is available,
854 @command{guix-daemon} can use it to compress build logs.
857 Unless @option{--disable-daemon} was passed to @command{configure}, the
858 following packages are also needed:
861 @item @url{https://gnupg.org/, GNU libgcrypt};
862 @item @url{https://sqlite.org, SQLite 3};
863 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
867 @cindex state directory
868 When configuring Guix on a system that already has a Guix installation,
869 be sure to specify the same state directory as the existing installation
870 using the @option{--localstatedir} option of the @command{configure}
871 script (@pxref{Directory Variables, @code{localstatedir},, standards,
872 GNU Coding Standards}). Usually, this @var{localstatedir} option is
873 set to the value @file{/var}. The @command{configure} script protects
874 against unintended misconfiguration of @var{localstatedir} so you do not
875 inadvertently corrupt your store (@pxref{The Store}).
877 @node Running the Test Suite
878 @section Running the Test Suite
881 After a successful @command{configure} and @code{make} run, it is a good
882 idea to run the test suite. It can help catch issues with the setup or
883 environment, or bugs in Guix itself---and really, reporting test
884 failures is a good way to help improve the software. To run the test
891 Test cases can run in parallel: you can use the @code{-j} option of
892 GNU@tie{}make to speed things up. The first run may take a few minutes
893 on a recent machine; subsequent runs will be faster because the store
894 that is created for test purposes will already have various things in
897 It is also possible to run a subset of the tests by defining the
898 @code{TESTS} makefile variable as in this example:
901 make check TESTS="tests/store.scm tests/cpio.scm"
904 By default, tests results are displayed at a file level. In order to
905 see the details of every individual test cases, it is possible to define
906 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
909 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
912 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
913 @file{test-suite.log} file. Please specify the Guix version being used
914 as well as version numbers of the dependencies (@pxref{Requirements}) in
917 Guix also comes with a whole-system test suite that tests complete
918 Guix System instances. It can only run on systems where
919 Guix is already installed, using:
926 or, again, by defining @code{TESTS} to select a subset of tests to run:
929 make check-system TESTS="basic mcron"
932 These system tests are defined in the @code{(gnu tests @dots{})}
933 modules. They work by running the operating systems under test with
934 lightweight instrumentation in a virtual machine (VM). They can be
935 computationally intensive or rather cheap, depending on whether
936 substitutes are available for their dependencies (@pxref{Substitutes}).
937 Some of them require a lot of storage space to hold VM images.
939 Again in case of test failures, please send @email{bug-guix@@gnu.org}
942 @node Setting Up the Daemon
943 @section Setting Up the Daemon
946 Operations such as building a package or running the garbage collector
947 are all performed by a specialized process, the @dfn{build daemon}, on
948 behalf of clients. Only the daemon may access the store and its
949 associated database. Thus, any operation that manipulates the store
950 goes through the daemon. For instance, command-line tools such as
951 @command{guix package} and @command{guix build} communicate with the
952 daemon (@i{via} remote procedure calls) to instruct it what to do.
954 The following sections explain how to prepare the build daemon's
955 environment. See also @ref{Substitutes}, for information on how to allow
956 the daemon to download pre-built binaries.
959 * Build Environment Setup:: Preparing the isolated build environment.
960 * Daemon Offload Setup:: Offloading builds to remote machines.
961 * SELinux Support:: Using an SELinux policy for the daemon.
964 @node Build Environment Setup
965 @subsection Build Environment Setup
967 @cindex build environment
968 In a standard multi-user setup, Guix and its daemon---the
969 @command{guix-daemon} program---are installed by the system
970 administrator; @file{/gnu/store} is owned by @code{root} and
971 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
972 Guix tools to build packages or otherwise access the store, and the
973 daemon will do it on their behalf, ensuring that the store is kept in a
974 consistent state, and allowing built packages to be shared among users.
977 When @command{guix-daemon} runs as @code{root}, you may not want package
978 build processes themselves to run as @code{root} too, for obvious
979 security reasons. To avoid that, a special pool of @dfn{build users}
980 should be created for use by build processes started by the daemon.
981 These build users need not have a shell and a home directory: they will
982 just be used when the daemon drops @code{root} privileges in build
983 processes. Having several such users allows the daemon to launch
984 distinct build processes under separate UIDs, which guarantees that they
985 do not interfere with each other---an essential feature since builds are
986 regarded as pure functions (@pxref{Introduction}).
988 On a GNU/Linux system, a build user pool may be created like this (using
989 Bash syntax and the @code{shadow} commands):
991 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
992 @c for why `-G' is needed.
994 # groupadd --system guixbuild
995 # for i in `seq -w 1 10`;
997 useradd -g guixbuild -G guixbuild \
998 -d /var/empty -s `which nologin` \
999 -c "Guix build user $i" --system \
1005 The number of build users determines how many build jobs may run in
1006 parallel, as specified by the @option{--max-jobs} option
1007 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
1008 @command{guix system vm} and related commands, you may need to add the
1009 build users to the @code{kvm} group so they can access @file{/dev/kvm},
1010 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
1011 (@pxref{Invoking guix system}).
1013 The @code{guix-daemon} program may then be run as @code{root} with the
1014 following command@footnote{If your machine uses the systemd init system,
1015 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
1016 file in @file{/etc/systemd/system} will ensure that
1017 @command{guix-daemon} is automatically started. Similarly, if your
1018 machine uses the Upstart init system, drop the
1019 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
1020 file in @file{/etc/init}.}:
1023 # guix-daemon --build-users-group=guixbuild
1028 This way, the daemon starts build processes in a chroot, under one of
1029 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
1030 environment contains nothing but:
1032 @c Keep this list in sync with libstore/build.cc! -----------------------
1035 a minimal @code{/dev} directory, created mostly independently from the
1036 host @code{/dev}@footnote{``Mostly'', because while the set of files
1037 that appear in the chroot's @code{/dev} is fixed, most of these files
1038 can only be created if the host has them.};
1041 the @code{/proc} directory; it only shows the processes of the container
1042 since a separate PID name space is used;
1045 @file{/etc/passwd} with an entry for the current user and an entry for
1049 @file{/etc/group} with an entry for the user's group;
1052 @file{/etc/hosts} with an entry that maps @code{localhost} to
1056 a writable @file{/tmp} directory.
1059 You can influence the directory where the daemon stores build trees
1060 @i{via} the @env{TMPDIR} environment variable. However, the build tree
1061 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
1062 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
1063 This way, the value of @env{TMPDIR} does not leak inside build
1064 environments, which avoids discrepancies in cases where build processes
1065 capture the name of their build tree.
1069 The daemon also honors the @env{http_proxy} and @env{https_proxy}
1070 environment variables for HTTP and HTTPS downloads it performs, be it
1071 for fixed-output derivations (@pxref{Derivations}) or for substitutes
1072 (@pxref{Substitutes}).
1074 If you are installing Guix as an unprivileged user, it is still possible
1075 to run @command{guix-daemon} provided you pass @option{--disable-chroot}.
1076 However, build processes will not be isolated from one another, and not
1077 from the rest of the system. Thus, build processes may interfere with
1078 each other, and may access programs, libraries, and other files
1079 available on the system---making it much harder to view them as
1080 @emph{pure} functions.
1083 @node Daemon Offload Setup
1084 @subsection Using the Offload Facility
1088 When desired, the build daemon can @dfn{offload} derivation builds to
1089 other machines running Guix, using the @code{offload} @dfn{build
1090 hook}@footnote{This feature is available only when
1091 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1092 present.}. When that feature is enabled, a list of user-specified build
1093 machines is read from @file{/etc/guix/machines.scm}; every time a build
1094 is requested, for instance via @code{guix build}, the daemon attempts to
1095 offload it to one of the machines that satisfy the constraints of the
1096 derivation, in particular its system types---e.g., @code{x86_64-linux}.
1097 A single machine can have multiple system types, either because its
1098 architecture natively supports it, via emulation
1099 (@pxref{transparent-emulation-qemu, Transparent Emulation with QEMU}),
1100 or both. Missing prerequisites for the build are
1101 copied over SSH to the target machine, which then proceeds with the
1102 build; upon success the output(s) of the build are copied back to the
1103 initial machine. The offload facility comes with a basic scheduler that
1104 attempts to select the best machine. The best machine is chosen among
1105 the available machines based on criteria such as:
1109 The availability of a build slot. A build machine can have as many
1110 build slots (connections) as the value of the @code{parallel-builds}
1111 field of its @code{build-machine} object.
1114 Its relative speed, as defined via the @code{speed} field of its
1115 @code{build-machine} object.
1118 Its load. The normalized machine load must be lower than a threshold
1119 value, configurable via the @code{overload-threshold} field of its
1120 @code{build-machine} object.
1123 Disk space availability. More than a 100 MiB must be available.
1126 The @file{/etc/guix/machines.scm} file typically looks like this:
1129 (list (build-machine
1130 (name "eightysix.example.org")
1131 (systems (list "x86_64-linux" "i686-linux"))
1132 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1134 (speed 2.)) ;incredibly fast!
1137 (name "armeight.example.org")
1138 (systems (list "aarch64-linux"))
1139 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1142 (string-append (getenv "HOME")
1143 "/.ssh/identity-for-guix"))))
1147 In the example above we specify a list of two build machines, one for
1148 the @code{x86_64} and @code{i686} architectures and one for the
1149 @code{aarch64} architecture.
1151 In fact, this file is---not surprisingly!---a Scheme file that is
1152 evaluated when the @code{offload} hook is started. Its return value
1153 must be a list of @code{build-machine} objects. While this example
1154 shows a fixed list of build machines, one could imagine, say, using
1155 DNS-SD to return a list of potential build machines discovered in the
1156 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1157 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1160 @deftp {Data Type} build-machine
1161 This data type represents build machines to which the daemon may offload
1162 builds. The important fields are:
1167 The host name of the remote machine.
1170 The system types the remote machine supports---e.g., @code{(list
1171 "x86_64-linux" "i686-linux")}.
1174 The user account to use when connecting to the remote machine over SSH.
1175 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1176 allow non-interactive logins.
1179 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1180 This is used to authenticate the machine when we connect to it. It is a
1181 long string that looks like this:
1184 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1187 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1188 key can be found in a file such as
1189 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1191 If the machine is running the SSH daemon of GNU@tie{}lsh,
1192 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1193 similar file. It can be converted to the OpenSSH format using
1194 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1197 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1198 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1203 A number of optional fields may be specified:
1207 @item @code{port} (default: @code{22})
1208 Port number of SSH server on the machine.
1210 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1211 The SSH private key file to use when connecting to the machine, in
1212 OpenSSH format. This key must not be protected with a passphrase.
1214 Note that the default value is the private key @emph{of the root
1215 account}. Make sure it exists if you use the default.
1217 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1218 @itemx @code{compression-level} (default: @code{3})
1219 The SSH-level compression methods and compression level requested.
1221 Note that offloading relies on SSH compression to reduce bandwidth usage
1222 when transferring files to and from build machines.
1224 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1225 File name of the Unix-domain socket @command{guix-daemon} is listening
1228 @item @code{overload-threshold} (default: @code{0.6})
1229 The load threshold above which a potential offload machine is
1230 disregarded by the offload scheduler. The value roughly translates to
1231 the total processor usage of the build machine, ranging from 0.0 (0%) to
1232 1.0 (100%). It can also be disabled by setting
1233 @code{overload-threshold} to @code{#f}.
1235 @item @code{parallel-builds} (default: @code{1})
1236 The number of builds that may run in parallel on the machine.
1238 @item @code{speed} (default: @code{1.0})
1239 A ``relative speed factor''. The offload scheduler will tend to prefer
1240 machines with a higher speed factor.
1242 @item @code{features} (default: @code{'()})
1243 A list of strings denoting specific features supported by the machine.
1244 An example is @code{"kvm"} for machines that have the KVM Linux modules
1245 and corresponding hardware support. Derivations can request features by
1246 name, and they will be scheduled on matching build machines.
1251 The @command{guix} command must be in the search path on the build
1252 machines. You can check whether this is the case by running:
1255 ssh build-machine guix repl --version
1258 There is one last thing to do once @file{machines.scm} is in place. As
1259 explained above, when offloading, files are transferred back and forth
1260 between the machine stores. For this to work, you first need to
1261 generate a key pair on each machine to allow the daemon to export signed
1262 archives of files from the store (@pxref{Invoking guix archive}):
1265 # guix archive --generate-key
1269 Each build machine must authorize the key of the master machine so that
1270 it accepts store items it receives from the master:
1273 # guix archive --authorize < master-public-key.txt
1277 Likewise, the master machine must authorize the key of each build machine.
1279 All the fuss with keys is here to express pairwise mutual trust
1280 relations between the master and the build machines. Concretely, when
1281 the master receives files from a build machine (and @i{vice versa}), its
1282 build daemon can make sure they are genuine, have not been tampered
1283 with, and that they are signed by an authorized key.
1285 @cindex offload test
1286 To test whether your setup is operational, run this command on the
1293 This will attempt to connect to each of the build machines specified in
1294 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1295 available on each machine, attempt to export to the machine and import
1296 from it, and report any error in the process.
1298 If you want to test a different machine file, just specify it on the
1302 # guix offload test machines-qualif.scm
1305 Last, you can test the subset of the machines whose name matches a
1306 regular expression like this:
1309 # guix offload test machines.scm '\.gnu\.org$'
1312 @cindex offload status
1313 To display the current load of all build hosts, run this command on the
1317 # guix offload status
1321 @node SELinux Support
1322 @subsection SELinux Support
1324 @cindex SELinux, daemon policy
1325 @cindex mandatory access control, SELinux
1326 @cindex security, guix-daemon
1327 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1328 can be installed on a system where SELinux is enabled, in order to label
1329 Guix files and to specify the expected behavior of the daemon. Since
1330 Guix System does not provide an SELinux base policy, the daemon policy cannot
1331 be used on Guix System.
1333 @subsubsection Installing the SELinux policy
1334 @cindex SELinux, policy installation
1335 To install the policy run this command as root:
1338 semodule -i etc/guix-daemon.cil
1341 Then relabel the file system with @code{restorecon} or by a different
1342 mechanism provided by your system.
1344 Once the policy is installed, the file system has been relabeled, and
1345 the daemon has been restarted, it should be running in the
1346 @code{guix_daemon_t} context. You can confirm this with the following
1350 ps -Zax | grep guix-daemon
1353 Monitor the SELinux log files as you run a command like @code{guix build
1354 hello} to convince yourself that SELinux permits all necessary
1357 @subsubsection Limitations
1358 @cindex SELinux, limitations
1360 This policy is not perfect. Here is a list of limitations or quirks
1361 that should be considered when deploying the provided SELinux policy for
1366 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1367 operations involve contexts that have anything to do with
1368 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1369 but it would be preferrable to define socket rules for only this label.
1372 @code{guix gc} cannot access arbitrary links to profiles. By design,
1373 the file label of the destination of a symlink is independent of the
1374 file label of the link itself. Although all profiles under
1375 $localstatedir are labelled, the links to these profiles inherit the
1376 label of the directory they are in. For links in the user’s home
1377 directory this will be @code{user_home_t}. But for links from the root
1378 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1379 directory, etc, this won’t work. @code{guix gc} would be prevented from
1380 reading and following these links.
1383 The daemon’s feature to listen for TCP connections might no longer work.
1384 This might require extra rules, because SELinux treats network sockets
1385 differently from files.
1388 Currently all files with a name matching the regular expression
1389 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1390 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1391 that name in any profile would be permitted to run in the
1392 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1393 build a package that provides this executable and convince a user to
1394 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1395 At that point SELinux could not prevent it from accessing files that are
1396 allowed for processes in that domain.
1398 You will need to relabel the store directory after all upgrades to
1399 @file{guix-daemon}, such as after running @code{guix pull}. Assuming the
1400 store is in @file{/gnu}, you can do this with @code{restorecon -vR /gnu},
1401 or by other means provided by your operating system.
1403 We could generate a much more restrictive policy at installation time,
1404 so that only the @emph{exact} file name of the currently installed
1405 @code{guix-daemon} executable would be labelled with
1406 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1407 The downside is that root would have to install or upgrade the policy at
1408 installation time whenever the Guix package that provides the
1409 effectively running @code{guix-daemon} executable is upgraded.
1412 @node Invoking guix-daemon
1413 @section Invoking @command{guix-daemon}
1415 The @command{guix-daemon} program implements all the functionality to
1416 access the store. This includes launching build processes, running the
1417 garbage collector, querying the availability of a build result, etc. It
1418 is normally run as @code{root} like this:
1421 # guix-daemon --build-users-group=guixbuild
1425 For details on how to set it up, @pxref{Setting Up the Daemon}.
1428 @cindex container, build environment
1429 @cindex build environment
1430 @cindex reproducible builds
1431 By default, @command{guix-daemon} launches build processes under
1432 different UIDs, taken from the build group specified with
1433 @option{--build-users-group}. In addition, each build process is run in a
1434 chroot environment that only contains the subset of the store that the
1435 build process depends on, as specified by its derivation
1436 (@pxref{Programming Interface, derivation}), plus a set of specific
1437 system directories. By default, the latter contains @file{/dev} and
1438 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1439 @dfn{container}: in addition to having its own file system tree, it has
1440 a separate mount name space, its own PID name space, network name space,
1441 etc. This helps achieve reproducible builds (@pxref{Features}).
1443 When the daemon performs a build on behalf of the user, it creates a
1444 build directory under @file{/tmp} or under the directory specified by
1445 its @env{TMPDIR} environment variable. This directory is shared with
1446 the container for the duration of the build, though within the container,
1447 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1449 The build directory is automatically deleted upon completion, unless the
1450 build failed and the client specified @option{--keep-failed}
1451 (@pxref{Invoking guix build, @option{--keep-failed}}).
1453 The daemon listens for connections and spawns one sub-process for each session
1454 started by a client (one of the @command{guix} sub-commands). The
1455 @command{guix processes} command allows you to get an overview of the activity
1456 on your system by viewing each of the active sessions and clients.
1457 @xref{Invoking guix processes}, for more information.
1459 The following command-line options are supported:
1462 @item --build-users-group=@var{group}
1463 Take users from @var{group} to run build processes (@pxref{Setting Up
1464 the Daemon, build users}).
1466 @item --no-substitutes
1468 Do not use substitutes for build products. That is, always build things
1469 locally instead of allowing downloads of pre-built binaries
1470 (@pxref{Substitutes}).
1472 When the daemon runs with @option{--no-substitutes}, clients can still
1473 explicitly enable substitution @i{via} the @code{set-build-options}
1474 remote procedure call (@pxref{The Store}).
1476 @anchor{daemon-substitute-urls}
1477 @item --substitute-urls=@var{urls}
1478 Consider @var{urls} the default whitespace-separated list of substitute
1479 source URLs. When this option is omitted,
1480 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1482 This means that substitutes may be downloaded from @var{urls}, as long
1483 as they are signed by a trusted signature (@pxref{Substitutes}).
1485 @xref{Getting Substitutes from Other Servers}, for more information on
1486 how to configure the daemon to get substitutes from other servers.
1490 Do not use offload builds to other machines (@pxref{Daemon Offload
1491 Setup}). That is, always build things locally instead of offloading
1492 builds to remote machines.
1494 @item --cache-failures
1495 Cache build failures. By default, only successful builds are cached.
1497 When this option is used, @command{guix gc --list-failures} can be used
1498 to query the set of store items marked as failed; @command{guix gc
1499 --clear-failures} removes store items from the set of cached failures.
1500 @xref{Invoking guix gc}.
1502 @item --cores=@var{n}
1504 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1507 The default value is @code{0}, but it may be overridden by clients, such
1508 as the @option{--cores} option of @command{guix build} (@pxref{Invoking
1511 The effect is to define the @env{NIX_BUILD_CORES} environment variable
1512 in the build process, which can then use it to exploit internal
1513 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1515 @item --max-jobs=@var{n}
1517 Allow at most @var{n} build jobs in parallel. The default value is
1518 @code{1}. Setting it to @code{0} means that no builds will be performed
1519 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1520 Setup}), or simply fail.
1522 @item --max-silent-time=@var{seconds}
1523 When the build or substitution process remains silent for more than
1524 @var{seconds}, terminate it and report a build failure.
1526 The default value is @code{0}, which disables the timeout.
1528 The value specified here can be overridden by clients (@pxref{Common
1529 Build Options, @option{--max-silent-time}}).
1531 @item --timeout=@var{seconds}
1532 Likewise, when the build or substitution process lasts for more than
1533 @var{seconds}, terminate it and report a build failure.
1535 The default value is @code{0}, which disables the timeout.
1537 The value specified here can be overridden by clients (@pxref{Common
1538 Build Options, @option{--timeout}}).
1540 @item --rounds=@var{N}
1541 Build each derivation @var{n} times in a row, and raise an error if
1542 consecutive build results are not bit-for-bit identical. Note that this
1543 setting can be overridden by clients such as @command{guix build}
1544 (@pxref{Invoking guix build}).
1546 When used in conjunction with @option{--keep-failed}, the differing
1547 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1548 This makes it easy to look for differences between the two results.
1551 Produce debugging output.
1553 This is useful to debug daemon start-up issues, but then it may be
1554 overridden by clients, for example the @option{--verbosity} option of
1555 @command{guix build} (@pxref{Invoking guix build}).
1557 @item --chroot-directory=@var{dir}
1558 Add @var{dir} to the build chroot.
1560 Doing this may change the result of build processes---for instance if
1561 they use optional dependencies found in @var{dir} when it is available,
1562 and not otherwise. For that reason, it is not recommended to do so.
1563 Instead, make sure that each derivation declares all the inputs that it
1566 @item --disable-chroot
1567 Disable chroot builds.
1569 Using this option is not recommended since, again, it would allow build
1570 processes to gain access to undeclared dependencies. It is necessary,
1571 though, when @command{guix-daemon} is running under an unprivileged user
1574 @item --log-compression=@var{type}
1575 Compress build logs according to @var{type}, one of @code{gzip},
1576 @code{bzip2}, or @code{none}.
1578 Unless @option{--lose-logs} is used, all the build logs are kept in the
1579 @var{localstatedir}. To save space, the daemon automatically compresses
1580 them with Bzip2 by default.
1582 @item --disable-deduplication
1583 @cindex deduplication
1584 Disable automatic file ``deduplication'' in the store.
1586 By default, files added to the store are automatically ``deduplicated'':
1587 if a newly added file is identical to another one found in the store,
1588 the daemon makes the new file a hard link to the other file. This can
1589 noticeably reduce disk usage, at the expense of slightly increased
1590 input/output load at the end of a build process. This option disables
1593 @item --gc-keep-outputs[=yes|no]
1594 Tell whether the garbage collector (GC) must keep outputs of live
1598 @cindex garbage collector roots
1599 When set to @code{yes}, the GC will keep the outputs of any live
1600 derivation available in the store---the @file{.drv} files. The default
1601 is @code{no}, meaning that derivation outputs are kept only if they are
1602 reachable from a GC root. @xref{Invoking guix gc}, for more on GC
1605 @item --gc-keep-derivations[=yes|no]
1606 Tell whether the garbage collector (GC) must keep derivations
1607 corresponding to live outputs.
1609 When set to @code{yes}, as is the case by default, the GC keeps
1610 derivations---i.e., @file{.drv} files---as long as at least one of their
1611 outputs is live. This allows users to keep track of the origins of
1612 items in their store. Setting it to @code{no} saves a bit of disk
1615 In this way, setting @option{--gc-keep-derivations} to @code{yes} causes
1616 liveness to flow from outputs to derivations, and setting
1617 @option{--gc-keep-outputs} to @code{yes} causes liveness to flow from
1618 derivations to outputs. When both are set to @code{yes}, the effect is
1619 to keep all the build prerequisites (the sources, compiler, libraries,
1620 and other build-time tools) of live objects in the store, regardless of
1621 whether these prerequisites are reachable from a GC root. This is
1622 convenient for developers since it saves rebuilds or downloads.
1624 @item --impersonate-linux-2.6
1625 On Linux-based systems, impersonate Linux 2.6. This means that the
1626 kernel's @command{uname} system call will report 2.6 as the release number.
1628 This might be helpful to build programs that (usually wrongfully) depend
1629 on the kernel version number.
1632 Do not keep build logs. By default they are kept under
1633 @file{@var{localstatedir}/guix/log}.
1635 @item --system=@var{system}
1636 Assume @var{system} as the current system type. By default it is the
1637 architecture/kernel pair found at configure time, such as
1638 @code{x86_64-linux}.
1640 @item --listen=@var{endpoint}
1641 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1642 as the file name of a Unix-domain socket if it starts with
1643 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1644 host name or host name and port to listen to. Here are a few examples:
1647 @item --listen=/gnu/var/daemon
1648 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1649 creating it if needed.
1651 @item --listen=localhost
1652 @cindex daemon, remote access
1653 @cindex remote access to the daemon
1654 @cindex daemon, cluster setup
1655 @cindex clusters, daemon setup
1656 Listen for TCP connections on the network interface corresponding to
1657 @code{localhost}, on port 44146.
1659 @item --listen=128.0.0.42:1234
1660 Listen for TCP connections on the network interface corresponding to
1661 @code{128.0.0.42}, on port 1234.
1664 This option can be repeated multiple times, in which case
1665 @command{guix-daemon} accepts connections on all the specified
1666 endpoints. Users can tell client commands what endpoint to connect to
1667 by setting the @env{GUIX_DAEMON_SOCKET} environment variable
1668 (@pxref{The Store, @env{GUIX_DAEMON_SOCKET}}).
1671 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1672 @option{--listen=@var{host}} is suitable on local networks, such as
1673 clusters, where only trusted nodes may connect to the build daemon. In
1674 other cases where remote access to the daemon is needed, we recommend
1675 using Unix-domain sockets along with SSH.
1678 When @option{--listen} is omitted, @command{guix-daemon} listens for
1679 connections on the Unix-domain socket located at
1680 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1684 @node Application Setup
1685 @section Application Setup
1687 @cindex foreign distro
1688 When using Guix on top of GNU/Linux distribution other than Guix System---a
1689 so-called @dfn{foreign distro}---a few additional steps are needed to
1690 get everything in place. Here are some of them.
1694 @anchor{locales-and-locpath}
1695 @cindex locales, when not on Guix System
1697 @vindex GUIX_LOCPATH
1698 Packages installed @i{via} Guix will not use the locale data of the
1699 host system. Instead, you must first install one of the locale packages
1700 available with Guix and then define the @env{GUIX_LOCPATH} environment
1704 $ guix install glibc-locales
1705 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1708 Note that the @code{glibc-locales} package contains data for all the
1709 locales supported by the GNU@tie{}libc and weighs in at around
1710 917@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1711 limited to a few UTF-8 locales.
1713 The @env{GUIX_LOCPATH} variable plays a role similar to @env{LOCPATH}
1714 (@pxref{Locale Names, @env{LOCPATH},, libc, The GNU C Library Reference
1715 Manual}). There are two important differences though:
1719 @env{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1720 provided by foreign distros. Thus, using @env{GUIX_LOCPATH} allows you
1721 to make sure the programs of the foreign distro will not end up loading
1722 incompatible locale data.
1725 libc suffixes each entry of @env{GUIX_LOCPATH} with @code{/X.Y}, where
1726 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1727 should your Guix profile contain a mixture of programs linked against
1728 different libc version, each libc version will only try to load locale
1729 data in the right format.
1732 This is important because the locale data format used by different libc
1733 versions may be incompatible.
1735 @subsection Name Service Switch
1737 @cindex name service switch, glibc
1738 @cindex NSS (name service switch), glibc
1739 @cindex nscd (name service caching daemon)
1740 @cindex name service caching daemon (nscd)
1741 When using Guix on a foreign distro, we @emph{strongly recommend} that
1742 the system run the GNU C library's @dfn{name service cache daemon},
1743 @command{nscd}, which should be listening on the
1744 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1745 installed with Guix may fail to look up host names or user accounts, or
1746 may even crash. The next paragraphs explain why.
1748 @cindex @file{nsswitch.conf}
1749 The GNU C library implements a @dfn{name service switch} (NSS), which is
1750 an extensible mechanism for ``name lookups'' in general: host name
1751 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1752 The GNU C Library Reference Manual}).
1754 @cindex Network information service (NIS)
1755 @cindex NIS (Network information service)
1756 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1757 lookup implementations: for example, the @code{nss-mdns} plugin allow
1758 resolution of @code{.local} host names, the @code{nis} plugin allows
1759 user account lookup using the Network information service (NIS), and so
1760 on. These extra ``lookup services'' are configured system-wide in
1761 @file{/etc/nsswitch.conf}, and all the programs running on the system
1762 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1765 When they perform a name lookup---for instance by calling the
1766 @code{getaddrinfo} function in C---applications first try to connect to
1767 the nscd; on success, nscd performs name lookups on their behalf. If
1768 the nscd is not running, then they perform the name lookup by
1769 themselves, by loading the name lookup services into their own address
1770 space and running it. These name lookup services---the
1771 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1772 the host system's C library, rather than from the C library the
1773 application is linked against (the C library coming from Guix).
1775 And this is where the problem is: if your application is linked against
1776 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1777 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1778 likely crash or have its name lookups fail unexpectedly.
1780 Running @command{nscd} on the system, among other advantages, eliminates
1781 this binary incompatibility problem because those @code{libnss_*.so}
1782 files are loaded in the @command{nscd} process, not in applications
1785 @subsection X11 Fonts
1788 The majority of graphical applications use Fontconfig to locate and
1789 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1790 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1791 by default. Thus, to allow graphical applications installed with Guix
1792 to display fonts, you have to install fonts with Guix as well.
1793 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1794 @code{font-gnu-freefont}.
1796 @cindex @code{fc-cache}
1798 Once you have installed or removed fonts, or when you notice an
1799 application that does not find fonts, you may need to install Fontconfig
1800 and to force an update of its font cache by running:
1803 guix install fontconfig
1807 To display text written in Chinese languages, Japanese, or Korean in
1808 graphical applications, consider installing
1809 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1810 has multiple outputs, one per language family (@pxref{Packages with
1811 Multiple Outputs}). For instance, the following command installs fonts
1812 for Chinese languages:
1815 guix install font-adobe-source-han-sans:cn
1818 @cindex @code{xterm}
1819 Older programs such as @command{xterm} do not use Fontconfig and instead
1820 rely on server-side font rendering. Such programs require to specify a
1821 full name of a font using XLFD (X Logical Font Description), like this:
1824 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1827 To be able to use such full names for the TrueType fonts installed in
1828 your Guix profile, you need to extend the font path of the X server:
1830 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1831 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1833 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1836 @cindex @code{xlsfonts}
1837 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1838 to make sure your TrueType fonts are listed there.
1841 @subsection X.509 Certificates
1843 @cindex @code{nss-certs}
1844 The @code{nss-certs} package provides X.509 certificates, which allow
1845 programs to authenticate Web servers accessed over HTTPS.
1847 When using Guix on a foreign distro, you can install this package and
1848 define the relevant environment variables so that packages know where to
1849 look for certificates. @xref{X.509 Certificates}, for detailed
1852 @subsection Emacs Packages
1854 @cindex @code{emacs}
1855 When you install Emacs packages with Guix, the Elisp files are placed
1856 under the @file{share/emacs/site-lisp/} directory of the profile in
1857 which they are installed. The Elisp libraries are made available to
1858 Emacs through the @env{EMACSLOADPATH} environment variable, which is
1859 set when installing Emacs itself.
1861 Additionally, autoload definitions are automatically evaluated at the
1862 initialization of Emacs, by the Guix-specific
1863 @code{guix-emacs-autoload-packages} procedure. If, for some reason, you
1864 want to avoid auto-loading the Emacs packages installed with Guix, you
1865 can do so by running Emacs with the @option{--no-site-file} option
1866 (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1869 @node Upgrading Guix
1870 @section Upgrading Guix
1872 @cindex Upgrading Guix, on a foreign distro
1874 To upgrade Guix, run:
1880 @xref{Invoking guix pull}, for more information.
1882 @cindex upgrading Guix for the root user, on a foreign distro
1883 @cindex upgrading the Guix daemon, on a foreign distro
1884 @cindex @command{guix pull} for the root user, on a foreign distro
1886 On a foreign distro, you can upgrade the build daemon by running:
1893 followed by (assuming your distro uses the systemd service management
1897 systemctl restart guix-daemon.service
1900 On Guix System, upgrading the daemon is achieved by reconfiguring the
1901 system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
1905 @c *********************************************************************
1906 @node System Installation
1907 @chapter System Installation
1909 @cindex installing Guix System
1910 @cindex Guix System, installation
1911 This section explains how to install Guix System
1912 on a machine. Guix, as a package manager, can
1913 also be installed on top of a running GNU/Linux system,
1914 @pxref{Installation}.
1918 @c This paragraph is for people reading this from tty2 of the
1919 @c installation image.
1920 You are reading this documentation with an Info reader. For details on
1921 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1922 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1923 Info}. Hit @kbd{l} afterwards to come back here.
1925 Alternatively, run @command{info info} in another tty to keep the manual
1931 * Limitations:: What you can expect.
1932 * Hardware Considerations:: Supported hardware.
1933 * USB Stick and DVD Installation:: Preparing the installation medium.
1934 * Preparing for Installation:: Networking, partitioning, etc.
1935 * Guided Graphical Installation:: Easy graphical installation.
1936 * Manual Installation:: Manual installation for wizards.
1937 * After System Installation:: When installation succeeded.
1938 * Installing Guix in a VM:: Guix System playground.
1939 * Building the Installation Image:: How this comes to be.
1943 @section Limitations
1945 We consider Guix System to be ready for a wide range of ``desktop'' and server
1946 use cases. The reliability guarantees it provides---transactional upgrades
1947 and rollbacks, reproducibility---make it a solid foundation.
1949 Nevertheless, before you proceed with the installation, be aware of the
1950 following noteworthy limitations applicable to version @value{VERSION}:
1954 More and more system services are provided (@pxref{Services}), but some
1958 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1959 as well as a number of X11 window managers. However, KDE is currently
1963 More than a disclaimer, this is an invitation to report issues (and success
1964 stories!), and to join us in improving it. @xref{Contributing}, for more
1968 @node Hardware Considerations
1969 @section Hardware Considerations
1971 @cindex hardware support on Guix System
1972 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1973 builds around the kernel Linux-libre, which means that only hardware for
1974 which free software drivers and firmware exist is supported. Nowadays,
1975 a wide range of off-the-shelf hardware is supported on
1976 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1977 Ethernet controllers. Unfortunately, there are still areas where
1978 hardware vendors deny users control over their own computing, and such
1979 hardware is not supported on Guix System.
1981 @cindex WiFi, hardware support
1982 One of the main areas where free drivers or firmware are lacking is WiFi
1983 devices. WiFi devices known to work include those using Atheros chips
1984 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1985 driver, and those using Broadcom/AirForce chips (BCM43xx with
1986 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1987 Linux-libre driver. Free firmware exists for both and is available
1988 out-of-the-box on Guix System, as part of @code{%base-firmware}
1989 (@pxref{operating-system Reference, @code{firmware}}).
1991 @cindex RYF, Respects Your Freedom
1992 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1993 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1994 certification program for hardware products that respect your freedom
1995 and your privacy and ensure that you have control over your device. We
1996 encourage you to check the list of RYF-certified devices.
1998 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1999 web site. It contains a catalog of hardware devices with information
2000 about their support in GNU/Linux.
2003 @node USB Stick and DVD Installation
2004 @section USB Stick and DVD Installation
2006 An ISO-9660 installation image that can be written to a USB stick or
2007 burnt to a DVD can be downloaded from
2008 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz},
2009 where you can replace @code{x86_64-linux} with one of:
2013 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
2016 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
2019 @c start duplication of authentication part from ``Binary Installation''
2020 Make sure to download the associated @file{.sig} file and to verify the
2021 authenticity of the image against it, along these lines:
2024 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
2025 $ gpg --verify guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
2028 If that command fails because you do not have the required public key,
2029 then run this command to import it:
2032 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
2033 -qO - | gpg --import -
2037 and rerun the @code{gpg --verify} command.
2039 Take note that a warning like ``This key is not certified with a trusted
2040 signature!'' is normal.
2044 This image contains the tools necessary for an installation.
2045 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
2047 @unnumberedsubsec Copying to a USB Stick
2049 To copy the image to a USB stick, follow these steps:
2053 Decompress the image using the @command{xz} command:
2056 xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
2060 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
2061 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
2062 copy the image with:
2065 dd if=guix-system-install-@value{VERSION}.x86_64-linux.iso of=/dev/sdX status=progress
2069 Access to @file{/dev/sdX} usually requires root privileges.
2072 @unnumberedsubsec Burning on a DVD
2074 To copy the image to a DVD, follow these steps:
2078 Decompress the image using the @command{xz} command:
2081 xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
2085 Insert a blank DVD into your machine, and determine
2086 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
2087 copy the image with:
2090 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.x86_64-linux.iso
2093 Access to @file{/dev/srX} usually requires root privileges.
2096 @unnumberedsubsec Booting
2098 Once this is done, you should be able to reboot the system and boot from
2099 the USB stick or DVD. The latter usually requires you to get in the
2100 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
2101 In order to boot from Libreboot, switch to the command mode by pressing
2102 the @kbd{c} key and type @command{search_grub usb}.
2104 @xref{Installing Guix in a VM}, if, instead, you would like to install
2105 Guix System in a virtual machine (VM).
2108 @node Preparing for Installation
2109 @section Preparing for Installation
2111 Once you have booted, you can use the guided graphical installer, which makes
2112 it easy to get started (@pxref{Guided Graphical Installation}). Alternatively,
2113 if you are already familiar with GNU/Linux and if you want more control than
2114 what the graphical installer provides, you can choose the ``manual''
2115 installation process (@pxref{Manual Installation}).
2117 The graphical installer is available on TTY1. You can obtain root shells on
2118 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
2119 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
2120 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
2121 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2122 which allows you to select text with the left mouse button and to paste it
2123 with the middle button.
2126 Installation requires access to the Internet so that any missing
2127 dependencies of your system configuration can be downloaded. See the
2128 ``Networking'' section below.
2131 @node Guided Graphical Installation
2132 @section Guided Graphical Installation
2134 The graphical installer is a text-based user interface. It will guide you,
2135 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2137 The first dialog boxes allow you to set up the system as you use it during the
2138 installation: you can choose the language, keyboard layout, and set up
2139 networking, which will be used during the installation. The image below shows
2140 the networking dialog.
2142 @image{images/installer-network,5in,, networking setup with the graphical installer}
2144 Later steps allow you to partition your hard disk, as shown in the image
2145 below, to choose whether or not to use encrypted file systems, to enter the
2146 host name and root password, and to create an additional account, among other
2149 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2151 Note that, at any time, the installer allows you to exit the current
2152 installation step and resume at a previous step, as show in the image below.
2154 @image{images/installer-resume,5in,, resuming the installation process}
2156 Once you're done, the installer produces an operating system configuration and
2157 displays it (@pxref{Using the Configuration System}). At that point you can
2158 hit ``OK'' and installation will proceed. On success, you can reboot into the
2159 new system and enjoy. @xref{After System Installation}, for what's next!
2162 @node Manual Installation
2163 @section Manual Installation
2165 This section describes how you would ``manually'' install GNU@tie{}Guix System
2166 on your machine. This option requires familiarity with GNU/Linux, with the
2167 shell, and with common administration tools. If you think this is not for
2168 you, consider using the guided graphical installer (@pxref{Guided Graphical
2171 The installation system provides root shells on TTYs 3 to 6; press
2172 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2173 many common tools needed to install the system. But it is also a full-blown
2174 Guix System, which means that you can install additional packages, should you
2175 need it, using @command{guix package} (@pxref{Invoking guix package}).
2178 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2179 * Proceeding with the Installation:: Installing.
2182 @node Keyboard Layout and Networking and Partitioning
2183 @subsection Keyboard Layout, Networking, and Partitioning
2185 Before you can install the system, you may want to adjust the keyboard layout,
2186 set up networking, and partition your target hard disk. This section will
2187 guide you through this.
2189 @subsubsection Keyboard Layout
2191 @cindex keyboard layout
2192 The installation image uses the US qwerty keyboard layout. If you want
2193 to change it, you can use the @command{loadkeys} command. For example,
2194 the following command selects the Dvorak keyboard layout:
2200 See the files under @file{/run/current-system/profile/share/keymaps} for
2201 a list of available keyboard layouts. Run @command{man loadkeys} for
2204 @subsubsection Networking
2206 Run the following command to see what your network interfaces are called:
2213 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2219 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2220 Wired interfaces have a name starting with @samp{e}; for example, the
2221 interface corresponding to the first on-board Ethernet controller is
2222 called @samp{eno1}. Wireless interfaces have a name starting with
2223 @samp{w}, like @samp{w1p2s0}.
2226 @item Wired connection
2227 To configure a wired network run the following command, substituting
2228 @var{interface} with the name of the wired interface you want to use.
2231 ifconfig @var{interface} up
2235 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2238 ip link set @var{interface} up
2241 @item Wireless connection
2244 To configure wireless networking, you can create a configuration file
2245 for the @command{wpa_supplicant} configuration tool (its location is not
2246 important) using one of the available text editors such as
2250 nano wpa_supplicant.conf
2253 As an example, the following stanza can go to this file and will work
2254 for many wireless networks, provided you give the actual SSID and
2255 passphrase for the network you are connecting to:
2259 ssid="@var{my-ssid}"
2261 psk="the network's secret passphrase"
2265 Start the wireless service and run it in the background with the
2266 following command (substitute @var{interface} with the name of the
2267 network interface you want to use):
2270 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2273 Run @command{man wpa_supplicant} for more information.
2277 At this point, you need to acquire an IP address. On a network where IP
2278 addresses are automatically assigned @i{via} DHCP, you can run:
2281 dhclient -v @var{interface}
2284 Try to ping a server to see if networking is up and running:
2290 Setting up network access is almost always a requirement because the
2291 image does not contain all the software and tools that may be needed.
2293 @cindex proxy, during system installation
2294 If you need HTTP and HTTPS access to go through a proxy, run the
2298 herd set-http-proxy guix-daemon @var{URL}
2302 where @var{URL} is the proxy URL, for example
2303 @code{http://example.org:8118}.
2305 @cindex installing over SSH
2306 If you want to, you can continue the installation remotely by starting
2310 herd start ssh-daemon
2313 Make sure to either set a password with @command{passwd}, or configure
2314 OpenSSH public key authentication before logging in.
2316 @subsubsection Disk Partitioning
2318 Unless this has already been done, the next step is to partition, and
2319 then format the target partition(s).
2321 The installation image includes several partitioning tools, including
2322 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2323 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2324 the partition layout you want:
2330 If your disk uses the GUID Partition Table (GPT) format and you plan to
2331 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2332 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2335 @cindex EFI, installation
2336 @cindex UEFI, installation
2337 @cindex ESP, EFI system partition
2338 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2339 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2340 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2343 parted /dev/sda set 1 esp on
2347 @vindex grub-bootloader
2348 @vindex grub-efi-bootloader
2349 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2350 @file{/sys/firmware/efi} exists in the installation image, then you should
2351 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2352 Otherwise you should use the BIOS-based GRUB, known as
2353 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2357 Once you are done partitioning the target hard disk drive, you have to
2358 create a file system on the relevant partition(s)@footnote{Currently
2359 Guix System only supports ext4, btrfs, and JFS file systems. In particular,
2360 code that reads file system UUIDs and labels only works for these file system
2361 types.}. For the ESP, if you have one and assuming it is
2362 @file{/dev/sda1}, run:
2365 mkfs.fat -F32 /dev/sda1
2368 For the root file system, ext4 is the most widely used format. Other
2369 file systems, such as Btrfs, support compression, which is reported to
2370 nicely complement file deduplication that the daemon performs
2371 independently of the file system (@pxref{Invoking guix-daemon,
2374 Preferably, assign file systems a label so that you can easily and
2375 reliably refer to them in @code{file-system} declarations (@pxref{File
2376 Systems}). This is typically done using the @code{-L} option of
2377 @command{mkfs.ext4} and related commands. So, assuming the target root
2378 partition lives at @file{/dev/sda2}, a file system with the label
2379 @code{my-root} can be created with:
2382 mkfs.ext4 -L my-root /dev/sda2
2385 @cindex encrypted disk
2386 If you are instead planning to encrypt the root partition, you can use
2387 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2388 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2389 @code{man cryptsetup}} for more information). Assuming you want to
2390 store the root partition on @file{/dev/sda2}, the command sequence would
2391 be along these lines:
2394 cryptsetup luksFormat /dev/sda2
2395 cryptsetup open --type luks /dev/sda2 my-partition
2396 mkfs.ext4 -L my-root /dev/mapper/my-partition
2399 Once that is done, mount the target file system under @file{/mnt}
2400 with a command like (again, assuming @code{my-root} is the label of the
2404 mount LABEL=my-root /mnt
2407 Also mount any other file systems you would like to use on the target
2408 system relative to this path. If you have opted for @file{/boot/efi} as an
2409 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2410 found by @code{guix system init} afterwards.
2412 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2413 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2414 sure to initialize them with @command{mkswap}. Assuming you have one
2415 swap partition on @file{/dev/sda3}, you would run:
2422 Alternatively, you may use a swap file. For example, assuming that in
2423 the new system you want to use the file @file{/swapfile} as a swap file,
2424 you would run@footnote{This example will work for many types of file
2425 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2426 btrfs), the required steps may be different. For details, see the
2427 manual pages for @command{mkswap} and @command{swapon}.}:
2430 # This is 10 GiB of swap space. Adjust "count" to change the size.
2431 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2432 # For security, make the file readable and writable only by root.
2433 chmod 600 /mnt/swapfile
2434 mkswap /mnt/swapfile
2435 swapon /mnt/swapfile
2438 Note that if you have encrypted the root partition and created a swap
2439 file in its file system as described above, then the encryption also
2440 protects the swap file, just like any other file in that file system.
2442 @node Proceeding with the Installation
2443 @subsection Proceeding with the Installation
2445 With the target partitions ready and the target root mounted on
2446 @file{/mnt}, we're ready to go. First, run:
2449 herd start cow-store /mnt
2452 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2453 during the installation phase are written to the target disk on @file{/mnt}
2454 rather than kept in memory. This is necessary because the first phase of
2455 the @command{guix system init} command (see below) entails downloads or
2456 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2458 Next, you have to edit a file and
2459 provide the declaration of the operating system to be installed. To
2460 that end, the installation system comes with three text editors. We
2461 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2462 supports syntax highlighting and parentheses matching; other editors
2463 include GNU Zile (an Emacs clone), and
2464 nvi (a clone of the original BSD @command{vi} editor).
2465 We strongly recommend storing that file on the target root file system, say,
2466 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2467 configuration file once you have rebooted into the newly-installed system.
2469 @xref{Using the Configuration System}, for an overview of the
2470 configuration file. The example configurations discussed in that
2471 section are available under @file{/etc/configuration} in the
2472 installation image. Thus, to get started with a system configuration
2473 providing a graphical display server (a ``desktop'' system), you can run
2474 something along these lines:
2478 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2479 # nano /mnt/etc/config.scm
2482 You should pay attention to what your configuration file contains, and
2487 Make sure the @code{bootloader-configuration} form refers to the target
2488 you want to install GRUB on. It should mention @code{grub-bootloader} if
2489 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2490 for newer UEFI systems. For legacy systems, the @code{target} field
2491 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2492 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2493 currently mounted and a @code{file-system} entry is specified in your
2497 Be sure that your file system labels match the value of their respective
2498 @code{device} fields in your @code{file-system} configuration, assuming
2499 your @code{file-system} configuration uses the @code{file-system-label}
2500 procedure in its @code{device} field.
2503 If there are encrypted or RAID partitions, make sure to add a
2504 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2507 Once you are done preparing the configuration file, the new system must
2508 be initialized (remember that the target root file system is mounted
2512 guix system init /mnt/etc/config.scm /mnt
2516 This copies all the necessary files and installs GRUB on
2517 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2518 more information, @pxref{Invoking guix system}. This command may trigger
2519 downloads or builds of missing packages, which can take some time.
2521 Once that command has completed---and hopefully succeeded!---you can run
2522 @command{reboot} and boot into the new system. The @code{root} password
2523 in the new system is initially empty; other users' passwords need to be
2524 initialized by running the @command{passwd} command as @code{root},
2525 unless your configuration specifies otherwise
2526 (@pxref{user-account-password, user account passwords}).
2527 @xref{After System Installation}, for what's next!
2530 @node After System Installation
2531 @section After System Installation
2533 Success, you've now booted into Guix System! From then on, you can update the
2534 system whenever you want by running, say:
2538 sudo guix system reconfigure /etc/config.scm
2542 This builds a new system generation with the latest packages and services
2543 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2544 your system includes the latest security updates (@pxref{Security Updates}).
2546 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2548 @cindex sudo vs. @command{guix pull}
2549 Note that @command{sudo guix} runs your user's @command{guix} command and
2550 @emph{not} root's, because @command{sudo} leaves @env{PATH} unchanged. To
2551 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2553 The difference matters here, because @command{guix pull} updates
2554 the @command{guix} command and package definitions only for the user it is ran
2555 as. This means that if you choose to use @command{guix system reconfigure} in
2556 root's login shell, you'll need to @command{guix pull} separately.
2559 Now, @pxref{Getting Started}, and
2560 join us on @code{#guix} on the Freenode IRC network or on
2561 @email{guix-devel@@gnu.org} to share your experience!
2564 @node Installing Guix in a VM
2565 @section Installing Guix in a Virtual Machine
2567 @cindex virtual machine, Guix System installation
2568 @cindex virtual private server (VPS)
2569 @cindex VPS (virtual private server)
2570 If you'd like to install Guix System in a virtual machine (VM) or on a
2571 virtual private server (VPS) rather than on your beloved machine, this
2574 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2575 disk image, follow these steps:
2579 First, retrieve and decompress the Guix system installation image as
2580 described previously (@pxref{USB Stick and DVD Installation}).
2583 Create a disk image that will hold the installed system. To make a
2584 qcow2-formatted disk image, use the @command{qemu-img} command:
2587 qemu-img create -f qcow2 guix-system.img 50G
2590 The resulting file will be much smaller than 50 GB (typically less than
2591 1 MB), but it will grow as the virtualized storage device is filled up.
2594 Boot the USB installation image in an VM:
2597 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2598 -nic user,model=virtio-net-pci -boot menu=on,order=d \
2599 -drive file=guix-system.img \
2600 -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
2603 @code{-enable-kvm} is optional, but significantly improves performance,
2604 @pxref{Running Guix in a VM}.
2607 You're now root in the VM, proceed with the installation process.
2608 @xref{Preparing for Installation}, and follow the instructions.
2611 Once installation is complete, you can boot the system that's on your
2612 @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
2615 @node Building the Installation Image
2616 @section Building the Installation Image
2618 @cindex installation image
2619 The installation image described above was built using the @command{guix
2620 system} command, specifically:
2623 guix system disk-image -t iso9660 gnu/system/install.scm
2626 Have a look at @file{gnu/system/install.scm} in the source tree,
2627 and see also @ref{Invoking guix system} for more information
2628 about the installation image.
2630 @section Building the Installation Image for ARM Boards
2632 Many ARM boards require a specific variant of the
2633 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2635 If you build a disk image and the bootloader is not available otherwise
2636 (on another boot drive etc), it's advisable to build an image that
2637 includes the bootloader, specifically:
2640 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2643 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2644 board, a list of possible boards will be printed.
2646 @c *********************************************************************
2647 @node Getting Started
2648 @chapter Getting Started
2650 Presumably, you've reached this section because either you have
2651 installed Guix on top of another distribution (@pxref{Installation}), or
2652 you've installed the standalone Guix System (@pxref{System
2653 Installation}). It's time for you to get started using Guix and this
2654 section aims to help you do that and give you a feel of what it's like.
2656 Guix is about installing software, so probably the first thing you'll
2657 want to do is to actually look for software. Let's say you're looking
2658 for a text editor, you can run:
2661 guix search text editor
2664 This command shows you a number of matching @dfn{packages}, each time
2665 showing the package's name, version, a description, and additional info.
2666 Once you've found out the one you want to use, let's say Emacs (ah ha!),
2667 you can go ahead and install it (run this command as a regular user,
2668 @emph{no need for root privileges}!):
2674 You've installed your first package, congrats! In the process, you've
2675 probably noticed that Guix downloaded pre-built binaries; or, if you
2676 explicitly chose to @emph{not} use pre-built binaries, then probably
2677 Guix is still building software (@pxref{Substitutes}, for more info).
2679 Unless you're using Guix System, the @command{guix install} command must
2680 have printed this hint:
2683 hint: Consider setting the necessary environment variables by running:
2685 GUIX_PROFILE="$HOME/.guix-profile"
2686 . "$GUIX_PROFILE/etc/profile"
2688 Alternately, see `guix package --search-paths -p "$HOME/.guix-profile"'.
2691 Indeed, you must now tell your shell where @command{emacs} and other
2692 programs installed with Guix are to be found. Pasting the two lines
2693 above will do just that: it will add
2694 @code{$HOME/.guix-profile/bin}---which is where the installed package
2695 is---to the @code{PATH} environment variable. You can paste these two
2696 lines in your shell so they take effect right away, but more importantly
2697 you should add them to @file{~/.bash_profile} (or equivalent file if you
2698 do not use Bash) so that environment variables are set next time you
2699 spawn a shell. You only need to do this once and other search paths
2700 environment variables will be taken care of similarly---e.g., if you
2701 eventually install @code{python} and Python libraries, @code{PYTHONPATH}
2704 You can go on installing packages at your will. To list installed
2708 guix package --list-installed
2711 To remove a package, you would unsurprisingly run @command{guix remove}.
2712 A distinguishing feature is the ability to @dfn{roll back} any operation
2713 you made---installation, removal, upgrade---by simply typing:
2716 guix package --roll-back
2719 This is because each operation is in fact a @dfn{transaction} that
2720 creates a new @dfn{generation}. These generations and the difference
2721 between them can be displayed by running:
2724 guix package --list-generations
2727 Now you know the basics of package management!
2729 @quotation Going further
2730 @xref{Package Management}, for more about package management. You may
2731 like @dfn{declarative} package management with @command{guix package
2732 --manifest}, managing separate @dfn{profiles} with @option{--profile},
2733 deleting old generations, collecting garbage, and other nifty features
2734 that will come in handy as you become more familiar with Guix. If you
2735 are a developer, @pxref{Development} for additional tools. And if
2736 you're curious, @pxref{Features}, to peek under the hood.
2739 Once you've installed a set of packages, you will want to periodically
2740 @emph{upgrade} them to the latest and greatest version. To do that, you
2741 will first pull the latest revision of Guix and its package collection:
2747 The end result is a new @command{guix} command, under
2748 @file{~/.config/guix/current/bin}. Unless you're on Guix System, the
2749 first time you run @command{guix pull}, be sure to follow the hint that
2750 the command prints and, similar to what we saw above, paste these two
2751 lines in your terminal and @file{.bash_profile}:
2754 GUIX_PROFILE="$HOME/.config/guix/current/etc/profile"
2755 . "$GUIX_PROFILE/etc/profile"
2759 You must also instruct your shell to point to this new @command{guix}:
2765 At this point, you're running a brand new Guix. You can thus go ahead
2766 and actually upgrade all the packages you previously installed:
2772 As you run this command, you will see that binaries are downloaded (or
2773 perhaps some packages are built), and eventually you end up with the
2774 upgraded packages. Should one of these upgraded packages not be to your
2775 liking, remember you can always roll back!
2777 You can display the exact revision of Guix you're currently using by
2784 The information it displays is @emph{all it takes to reproduce the exact
2785 same Guix}, be it at a different point in time or on a different
2788 @quotation Going further
2789 @xref{Invoking guix pull}, for more information. @xref{Channels}, on
2790 how to specify additional @dfn{channels} to pull packages from, how to
2791 replicate Guix, and more. You may also find @command{time-machine}
2792 handy (@pxref{Invoking guix time-machine}).
2795 If you installed Guix System, one of the first things you'll want to do
2796 is to upgrade your system. Once you've run @command{guix pull} to get
2797 the latest Guix, you can upgrade the system like this:
2800 sudo guix system reconfigure /etc/config.scm
2803 Upon completion, the system runs the latest versions of its software
2804 packages. When you eventually reboot, you'll notice a sub-menu in the
2805 bootloader that reads ``Old system generations'': it's what allows you
2806 to boot @emph{an older generation of your system}, should the latest
2807 generation be ``broken'' or otherwise unsatisfying. Just like for
2808 packages, you can always @emph{roll back} to a previous generation
2809 @emph{of the whole system}:
2812 sudo guix system roll-back
2815 There are many things you'll probably want to tweak on your system:
2816 adding new user accounts, adding new system services, fiddling with the
2817 configuration of those services, etc. The system configuration is
2818 @emph{entirely} described in the @file{/etc/config.scm} file.
2819 @xref{Using the Configuration System}, to learn how to change it.
2821 Now you know enough to get started!
2823 @quotation Resources
2824 The rest of this manual provides a reference for all things Guix. Here
2825 are some additional resources you may find useful:
2829 @xref{Top,,, guix-cookbook, The GNU Guix Cookbook}, for a list of
2830 ``how-to'' style of recipes for a variety of applications.
2833 The @uref{https://guix.gnu.org/guix-refcard.pdf, GNU Guix Reference
2834 Card} lists in two pages most of the commands and options you'll ever
2838 The web site contains @uref{https://guix.gnu.org/en/videos/,
2839 instructional videos} covering topics such as everyday use of Guix, how
2840 to get help, and how to become a contributor.
2843 @xref{Documentation}, to learn how to access documentation on your
2847 We hope you will enjoy Guix as much as the community enjoys building it!
2850 @c *********************************************************************
2851 @node Package Management
2852 @chapter Package Management
2855 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2856 remove software packages, without having to know about their build
2857 procedures or dependencies. Guix also goes beyond this obvious set of
2860 This chapter describes the main features of Guix, as well as the
2861 package management tools it provides. Along with the command-line
2862 interface described below (@pxref{Invoking guix package, @code{guix
2863 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2864 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2865 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2869 guix install emacs-guix
2873 * Features:: How Guix will make your life brighter.
2874 * Invoking guix package:: Package installation, removal, etc.
2875 * Substitutes:: Downloading pre-built binaries.
2876 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2877 * Invoking guix gc:: Running the garbage collector.
2878 * Invoking guix pull:: Fetching the latest Guix and distribution.
2879 * Invoking guix time-machine:: Running an older revision of Guix.
2880 * Inferiors:: Interacting with another revision of Guix.
2881 * Invoking guix describe:: Display information about your Guix revision.
2882 * Invoking guix archive:: Exporting and importing store files.
2888 Here we assume you've already made your first steps with Guix
2889 (@pxref{Getting Started}) and would like to get an overview about what's
2890 going on under the hood.
2892 When using Guix, each package ends up in the @dfn{package store}, in its
2893 own directory---something that resembles
2894 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2896 Instead of referring to these directories, users have their own
2897 @dfn{profile}, which points to the packages that they actually want to
2898 use. These profiles are stored within each user's home directory, at
2899 @code{$HOME/.guix-profile}.
2901 For example, @code{alice} installs GCC 4.7.2. As a result,
2902 @file{/home/alice/.guix-profile/bin/gcc} points to
2903 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2904 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2905 simply continues to point to
2906 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2907 coexist on the same system without any interference.
2909 The @command{guix package} command is the central tool to manage
2910 packages (@pxref{Invoking guix package}). It operates on the per-user
2911 profiles, and can be used @emph{with normal user privileges}.
2913 @cindex transactions
2914 The command provides the obvious install, remove, and upgrade
2915 operations. Each invocation is actually a @emph{transaction}: either
2916 the specified operation succeeds, or nothing happens. Thus, if the
2917 @command{guix package} process is terminated during the transaction,
2918 or if a power outage occurs during the transaction, then the user's
2919 profile remains in its previous state, and remains usable.
2921 In addition, any package transaction may be @emph{rolled back}. So, if,
2922 for example, an upgrade installs a new version of a package that turns
2923 out to have a serious bug, users may roll back to the previous instance
2924 of their profile, which was known to work well. Similarly, the global
2925 system configuration on Guix is subject to
2926 transactional upgrades and roll-back
2927 (@pxref{Using the Configuration System}).
2929 All packages in the package store may be @emph{garbage-collected}.
2930 Guix can determine which packages are still referenced by user
2931 profiles, and remove those that are provably no longer referenced
2932 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2933 generations of their profile so that the packages they refer to can be
2936 @cindex reproducibility
2937 @cindex reproducible builds
2938 Guix takes a @dfn{purely functional} approach to package
2939 management, as described in the introduction (@pxref{Introduction}).
2940 Each @file{/gnu/store} package directory name contains a hash of all the
2941 inputs that were used to build that package---compiler, libraries, build
2942 scripts, etc. This direct correspondence allows users to make sure a
2943 given package installation matches the current state of their
2944 distribution. It also helps maximize @dfn{build reproducibility}:
2945 thanks to the isolated build environments that are used, a given build
2946 is likely to yield bit-identical files when performed on different
2947 machines (@pxref{Invoking guix-daemon, container}).
2950 This foundation allows Guix to support @dfn{transparent binary/source
2951 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2952 available from an external source---a @dfn{substitute}, Guix just
2953 downloads it and unpacks it;
2954 otherwise, it builds the package from source, locally
2955 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2956 reproducible, users do not have to trust servers that provide
2957 substitutes: they can force a local build and @emph{challenge} providers
2958 (@pxref{Invoking guix challenge}).
2960 Control over the build environment is a feature that is also useful for
2961 developers. The @command{guix environment} command allows developers of
2962 a package to quickly set up the right development environment for their
2963 package, without having to manually install the dependencies of the
2964 package into their profile (@pxref{Invoking guix environment}).
2966 @cindex replication, of software environments
2967 @cindex provenance tracking, of software artifacts
2968 All of Guix and its package definitions is version-controlled, and
2969 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2970 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2971 Guix instance on a different machine or at a later point in time, which in
2972 turn allows you to @emph{replicate complete software environments}, while
2973 retaining precise @dfn{provenance tracking} of the software.
2975 @node Invoking guix package
2976 @section Invoking @command{guix package}
2978 @cindex installing packages
2979 @cindex removing packages
2980 @cindex package installation
2981 @cindex package removal
2982 The @command{guix package} command is the tool that allows users to
2983 install, upgrade, and remove packages, as well as rolling back to
2984 previous configurations. It operates only on the user's own profile,
2985 and works with normal user privileges (@pxref{Features}). Its syntax
2989 guix package @var{options}
2992 @cindex transactions
2993 Primarily, @var{options} specifies the operations to be performed during
2994 the transaction. Upon completion, a new profile is created, but
2995 previous @dfn{generations} of the profile remain available, should the user
2998 For example, to remove @code{lua} and install @code{guile} and
2999 @code{guile-cairo} in a single transaction:
3002 guix package -r lua -i guile guile-cairo
3005 @cindex aliases, for @command{guix package}
3006 For your convenience, we also provide the following aliases:
3010 @command{guix search} is an alias for @command{guix package -s},
3012 @command{guix install} is an alias for @command{guix package -i},
3014 @command{guix remove} is an alias for @command{guix package -r},
3016 @command{guix upgrade} is an alias for @command{guix package -u},
3018 and @command{guix show} is an alias for @command{guix package --show=}.
3021 These aliases are less expressive than @command{guix package} and provide
3022 fewer options, so in some cases you'll probably want to use @command{guix
3025 @command{guix package} also supports a @dfn{declarative approach}
3026 whereby the user specifies the exact set of packages to be available and
3027 passes it @i{via} the @option{--manifest} option
3028 (@pxref{profile-manifest, @option{--manifest}}).
3031 For each user, a symlink to the user's default profile is automatically
3032 created in @file{$HOME/.guix-profile}. This symlink always points to the
3033 current generation of the user's default profile. Thus, users can add
3034 @file{$HOME/.guix-profile/bin} to their @env{PATH} environment
3035 variable, and so on.
3036 @cindex search paths
3037 If you are not using Guix System, consider adding the
3038 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
3039 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
3040 shells get all the right environment variable definitions:
3043 GUIX_PROFILE="$HOME/.guix-profile" ; \
3044 source "$HOME/.guix-profile/etc/profile"
3047 In a multi-user setup, user profiles are stored in a place registered as
3048 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
3049 to (@pxref{Invoking guix gc}). That directory is normally
3050 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
3051 @var{localstatedir} is the value passed to @code{configure} as
3052 @option{--localstatedir}, and @var{user} is the user name. The
3053 @file{per-user} directory is created when @command{guix-daemon} is
3054 started, and the @var{user} sub-directory is created by @command{guix
3057 The @var{options} can be among the following:
3061 @item --install=@var{package} @dots{}
3062 @itemx -i @var{package} @dots{}
3063 Install the specified @var{package}s.
3065 Each @var{package} may specify either a simple package name, such as
3066 @code{guile}, or a package name followed by an at-sign and version number,
3067 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
3068 case, the newest version prefixed by @code{1.8} is selected).
3070 If no version number is specified, the
3071 newest available version will be selected. In addition, @var{package}
3072 may contain a colon, followed by the name of one of the outputs of the
3073 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
3074 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
3075 name (and optionally version) are searched for among the GNU
3076 distribution modules (@pxref{Package Modules}).
3078 @cindex propagated inputs
3079 Sometimes packages have @dfn{propagated inputs}: these are dependencies
3080 that automatically get installed along with the required package
3081 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
3082 @code{package} objects}, for information about propagated inputs in
3083 package definitions).
3085 @anchor{package-cmd-propagated-inputs}
3086 An example is the GNU MPC library: its C header files refer to those of
3087 the GNU MPFR library, which in turn refer to those of the GMP library.
3088 Thus, when installing MPC, the MPFR and GMP libraries also get installed
3089 in the profile; removing MPC also removes MPFR and GMP---unless they had
3090 also been explicitly installed by the user.
3092 Besides, packages sometimes rely on the definition of environment
3093 variables for their search paths (see explanation of
3094 @option{--search-paths} below). Any missing or possibly incorrect
3095 environment variable definitions are reported here.
3097 @item --install-from-expression=@var{exp}
3099 Install the package @var{exp} evaluates to.
3101 @var{exp} must be a Scheme expression that evaluates to a
3102 @code{<package>} object. This option is notably useful to disambiguate
3103 between same-named variants of a package, with expressions such as
3104 @code{(@@ (gnu packages base) guile-final)}.
3106 Note that this option installs the first output of the specified
3107 package, which may be insufficient when needing a specific output of a
3108 multiple-output package.
3110 @item --install-from-file=@var{file}
3111 @itemx -f @var{file}
3112 Install the package that the code within @var{file} evaluates to.
3114 As an example, @var{file} might contain a definition like this
3115 (@pxref{Defining Packages}):
3118 @include package-hello.scm
3121 Developers may find it useful to include such a @file{guix.scm} file
3122 in the root of their project source tree that can be used to test
3123 development snapshots and create reproducible development environments
3124 (@pxref{Invoking guix environment}).
3126 The @var{file} may also contain a JSON representation of one or more
3127 package definitions. Running @code{guix package -f} on
3128 @file{hello.json} with the following contents would result in installing
3129 the package @code{greeter} after building @code{myhello}:
3132 @verbatiminclude package-hello.json
3135 @item --remove=@var{package} @dots{}
3136 @itemx -r @var{package} @dots{}
3137 Remove the specified @var{package}s.
3139 As for @option{--install}, each @var{package} may specify a version number
3140 and/or output name in addition to the package name. For instance,
3141 @samp{-r glibc:debug} would remove the @code{debug} output of
3144 @item --upgrade[=@var{regexp} @dots{}]
3145 @itemx -u [@var{regexp} @dots{}]
3146 @cindex upgrading packages
3147 Upgrade all the installed packages. If one or more @var{regexp}s are
3148 specified, upgrade only installed packages whose name matches a
3149 @var{regexp}. Also see the @option{--do-not-upgrade} option below.
3151 Note that this upgrades package to the latest version of packages found
3152 in the distribution currently installed. To update your distribution,
3153 you should regularly run @command{guix pull} (@pxref{Invoking guix
3156 @cindex package transformations, upgrades
3157 When upgrading, package transformations that were originally applied
3158 when creating the profile are automatically re-applied (@pxref{Package
3159 Transformation Options}). For example, assume you first installed Emacs
3160 from the tip of its development branch with:
3163 guix install emacs-next --with-branch=emacs-next=master
3166 Next time you run @command{guix upgrade}, Guix will again pull the tip
3167 of the Emacs development branch and build @code{emacs-next} from that
3170 Note that transformation options such as @option{--with-branch} and
3171 @option{--with-source} depend on external state; it is up to you to
3172 ensure that they work as expected. You can also discard a
3173 transformations that apply to a package by running:
3176 guix install @var{package}
3179 @item --do-not-upgrade[=@var{regexp} @dots{}]
3180 When used together with the @option{--upgrade} option, do @emph{not}
3181 upgrade any packages whose name matches a @var{regexp}. For example, to
3182 upgrade all packages in the current profile except those containing the
3183 substring ``emacs'':
3186 $ guix package --upgrade . --do-not-upgrade emacs
3189 @item @anchor{profile-manifest}--manifest=@var{file}
3190 @itemx -m @var{file}
3191 @cindex profile declaration
3192 @cindex profile manifest
3193 Create a new generation of the profile from the manifest object
3194 returned by the Scheme code in @var{file}. This option can be repeated
3195 several times, in which case the manifests are concatenated.
3197 This allows you to @emph{declare} the profile's contents rather than
3198 constructing it through a sequence of @option{--install} and similar
3199 commands. The advantage is that @var{file} can be put under version
3200 control, copied to different machines to reproduce the same profile, and
3203 @c FIXME: Add reference to (guix profile) documentation when available.
3204 @var{file} must return a @dfn{manifest} object, which is roughly a list
3207 @findex packages->manifest
3209 (use-package-modules guile emacs)
3214 ;; Use a specific package output.
3215 (list guile-2.0 "debug")))
3218 @findex specifications->manifest
3219 In this example we have to know which modules define the @code{emacs}
3220 and @code{guile-2.0} variables to provide the right
3221 @code{use-package-modules} line, which can be cumbersome. We can
3222 instead provide regular package specifications and let
3223 @code{specifications->manifest} look up the corresponding package
3227 (specifications->manifest
3228 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
3232 @cindex rolling back
3233 @cindex undoing transactions
3234 @cindex transactions, undoing
3235 Roll back to the previous @dfn{generation} of the profile---i.e., undo
3236 the last transaction.
3238 When combined with options such as @option{--install}, roll back occurs
3239 before any other actions.
3241 When rolling back from the first generation that actually contains
3242 installed packages, the profile is made to point to the @dfn{zeroth
3243 generation}, which contains no files apart from its own metadata.
3245 After having rolled back, installing, removing, or upgrading packages
3246 overwrites previous future generations. Thus, the history of the
3247 generations in a profile is always linear.
3249 @item --switch-generation=@var{pattern}
3250 @itemx -S @var{pattern}
3252 Switch to a particular generation defined by @var{pattern}.
3254 @var{pattern} may be either a generation number or a number prefixed
3255 with ``+'' or ``-''. The latter means: move forward/backward by a
3256 specified number of generations. For example, if you want to return to
3257 the latest generation after @option{--roll-back}, use
3258 @option{--switch-generation=+1}.
3260 The difference between @option{--roll-back} and
3261 @option{--switch-generation=-1} is that @option{--switch-generation} will
3262 not make a zeroth generation, so if a specified generation does not
3263 exist, the current generation will not be changed.
3265 @item --search-paths[=@var{kind}]
3266 @cindex search paths
3267 Report environment variable definitions, in Bash syntax, that may be
3268 needed in order to use the set of installed packages. These environment
3269 variables are used to specify @dfn{search paths} for files used by some
3270 of the installed packages.
3272 For example, GCC needs the @env{CPATH} and @env{LIBRARY_PATH}
3273 environment variables to be defined so it can look for headers and
3274 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
3275 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
3276 library are installed in the profile, then @option{--search-paths} will
3277 suggest setting these variables to @file{@var{profile}/include} and
3278 @file{@var{profile}/lib}, respectively.
3280 The typical use case is to define these environment variables in the
3284 $ eval `guix package --search-paths`
3287 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
3288 meaning that the returned environment variable definitions will either
3289 be exact settings, or prefixes or suffixes of the current value of these
3290 variables. When omitted, @var{kind} defaults to @code{exact}.
3292 This option can also be used to compute the @emph{combined} search paths
3293 of several profiles. Consider this example:
3296 $ guix package -p foo -i guile
3297 $ guix package -p bar -i guile-json
3298 $ guix package -p foo -p bar --search-paths
3301 The last command above reports about the @env{GUILE_LOAD_PATH}
3302 variable, even though, taken individually, neither @file{foo} nor
3303 @file{bar} would lead to that recommendation.
3306 @item --profile=@var{profile}
3307 @itemx -p @var{profile}
3308 Use @var{profile} instead of the user's default profile.
3310 @var{profile} must be the name of a file that will be created upon
3311 completion. Concretely, @var{profile} will be a mere symbolic link
3312 (``symlink'') pointing to the actual profile where packages are
3316 $ guix install hello -p ~/code/my-profile
3318 $ ~/code/my-profile/bin/hello
3322 All it takes to get rid of the profile is to remove this symlink and its
3323 siblings that point to specific generations:
3326 $ rm ~/code/my-profile ~/code/my-profile-*-link
3329 @item --list-profiles
3330 List all the user's profiles:
3333 $ guix package --list-profiles
3334 /home/charlie/.guix-profile
3335 /home/charlie/code/my-profile
3336 /home/charlie/code/devel-profile
3337 /home/charlie/tmp/test
3340 When running as root, list all the profiles of all the users.
3342 @cindex collisions, in a profile
3343 @cindex colliding packages in profiles
3344 @cindex profile collisions
3345 @item --allow-collisions
3346 Allow colliding packages in the new profile. Use at your own risk!
3348 By default, @command{guix package} reports as an error @dfn{collisions}
3349 in the profile. Collisions happen when two or more different versions
3350 or variants of a given package end up in the profile.
3353 Use the bootstrap Guile to build the profile. This option is only
3354 useful to distribution developers.
3358 In addition to these actions, @command{guix package} supports the
3359 following options to query the current state of a profile, or the
3360 availability of packages:
3364 @item --search=@var{regexp}
3365 @itemx -s @var{regexp}
3366 @anchor{guix-search}
3367 @cindex searching for packages
3368 List the available packages whose name, synopsis, or description matches
3369 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
3370 Print all the metadata of matching packages in
3371 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
3372 GNU recutils manual}).
3374 This allows specific fields to be extracted using the @command{recsel}
3375 command, for instance:
3378 $ guix package -s malloc | recsel -p name,version,relevance
3392 Similarly, to show the name of all the packages available under the
3393 terms of the GNU@tie{}LGPL version 3:
3396 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
3403 It is also possible to refine search results using several @code{-s} flags to
3404 @command{guix package}, or several arguments to @command{guix search}. For
3405 example, the following command returns a list of board games (this time using
3406 the @command{guix search} alias):
3409 $ guix search '\<board\>' game | recsel -p name
3414 If we were to omit @code{-s game}, we would also get software packages
3415 that deal with printed circuit boards; removing the angle brackets
3416 around @code{board} would further add packages that have to do with
3419 And now for a more elaborate example. The following command searches
3420 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
3421 libraries, and prints the name and synopsis of the matching packages:
3424 $ guix search crypto library | \
3425 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3429 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3430 information on @dfn{selection expressions} for @code{recsel -e}.
3432 @item --show=@var{package}
3433 Show details about @var{package}, taken from the list of available packages, in
3434 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3438 $ guix package --show=python | recsel -p name,version
3446 You may also specify the full name of a package to only get details about a
3447 specific version of it (this time using the @command{guix show} alias):
3449 $ guix show python@@3.4 | recsel -p name,version
3456 @item --list-installed[=@var{regexp}]
3457 @itemx -I [@var{regexp}]
3458 List the currently installed packages in the specified profile, with the
3459 most recently installed packages shown last. When @var{regexp} is
3460 specified, list only installed packages whose name matches @var{regexp}.
3462 For each installed package, print the following items, separated by
3463 tabs: the package name, its version string, the part of the package that
3464 is installed (for instance, @code{out} for the default output,
3465 @code{include} for its headers, etc.), and the path of this package in
3468 @item --list-available[=@var{regexp}]
3469 @itemx -A [@var{regexp}]
3470 List packages currently available in the distribution for this system
3471 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3472 available packages whose name matches @var{regexp}.
3474 For each package, print the following items separated by tabs: its name,
3475 its version string, the parts of the package (@pxref{Packages with
3476 Multiple Outputs}), and the source location of its definition.
3478 @item --list-generations[=@var{pattern}]
3479 @itemx -l [@var{pattern}]
3481 Return a list of generations along with their creation dates; for each
3482 generation, show the installed packages, with the most recently
3483 installed packages shown last. Note that the zeroth generation is never
3486 For each installed package, print the following items, separated by
3487 tabs: the name of a package, its version string, the part of the package
3488 that is installed (@pxref{Packages with Multiple Outputs}), and the
3489 location of this package in the store.
3491 When @var{pattern} is used, the command returns only matching
3492 generations. Valid patterns include:
3495 @item @emph{Integers and comma-separated integers}. Both patterns denote
3496 generation numbers. For instance, @option{--list-generations=1} returns
3499 And @option{--list-generations=1,8,2} outputs three generations in the
3500 specified order. Neither spaces nor trailing commas are allowed.
3502 @item @emph{Ranges}. @option{--list-generations=2..9} prints the
3503 specified generations and everything in between. Note that the start of
3504 a range must be smaller than its end.
3506 It is also possible to omit the endpoint. For example,
3507 @option{--list-generations=2..}, returns all generations starting from the
3510 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3511 or months by passing an integer along with the first letter of the
3512 duration. For example, @option{--list-generations=20d} lists generations
3513 that are up to 20 days old.
3516 @item --delete-generations[=@var{pattern}]
3517 @itemx -d [@var{pattern}]
3518 When @var{pattern} is omitted, delete all generations except the current
3521 This command accepts the same patterns as @option{--list-generations}.
3522 When @var{pattern} is specified, delete the matching generations. When
3523 @var{pattern} specifies a duration, generations @emph{older} than the
3524 specified duration match. For instance, @option{--delete-generations=1m}
3525 deletes generations that are more than one month old.
3527 If the current generation matches, it is @emph{not} deleted. Also, the
3528 zeroth generation is never deleted.
3530 Note that deleting generations prevents rolling back to them.
3531 Consequently, this command must be used with care.
3535 Finally, since @command{guix package} may actually start build
3536 processes, it supports all the common build options (@pxref{Common Build
3537 Options}). It also supports package transformation options, such as
3538 @option{--with-source} (@pxref{Package Transformation Options}).
3539 However, note that package transformations are lost when upgrading; to
3540 preserve transformations across upgrades, you should define your own
3541 package variant in a Guile module and add it to @env{GUIX_PACKAGE_PATH}
3542 (@pxref{Defining Packages}).
3545 @section Substitutes
3548 @cindex pre-built binaries
3549 Guix supports transparent source/binary deployment, which means that it
3550 can either build things locally, or download pre-built items from a
3551 server, or both. We call these pre-built items @dfn{substitutes}---they
3552 are substitutes for local build results. In many cases, downloading a
3553 substitute is much faster than building things locally.
3555 Substitutes can be anything resulting from a derivation build
3556 (@pxref{Derivations}). Of course, in the common case, they are
3557 pre-built package binaries, but source tarballs, for instance, which
3558 also result from derivation builds, can be available as substitutes.
3561 * Official Substitute Server:: One particular source of substitutes.
3562 * Substitute Server Authorization:: How to enable or disable substitutes.
3563 * Getting Substitutes from Other Servers:: Substitute diversity.
3564 * Substitute Authentication:: How Guix verifies substitutes.
3565 * Proxy Settings:: How to get substitutes via proxy.
3566 * Substitution Failure:: What happens when substitution fails.
3567 * On Trusting Binaries:: How can you trust that binary blob?
3570 @node Official Substitute Server
3571 @subsection Official Substitute Server
3574 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3575 that builds packages from Guix continuously for some
3576 architectures, and makes them available as substitutes. This is the
3577 default source of substitutes; it can be overridden by passing the
3578 @option{--substitute-urls} option either to @command{guix-daemon}
3579 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3580 or to client tools such as @command{guix package}
3581 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3584 Substitute URLs can be either HTTP or HTTPS.
3585 HTTPS is recommended because communications are encrypted; conversely,
3586 using HTTP makes all communications visible to an eavesdropper, who
3587 could use the information gathered to determine, for instance, whether
3588 your system has unpatched security vulnerabilities.
3590 Substitutes from the official build farm are enabled by default when
3591 using Guix System (@pxref{GNU Distribution}). However,
3592 they are disabled by default when using Guix on a foreign distribution,
3593 unless you have explicitly enabled them via one of the recommended
3594 installation steps (@pxref{Installation}). The following paragraphs
3595 describe how to enable or disable substitutes for the official build
3596 farm; the same procedure can also be used to enable substitutes for any
3597 other substitute server.
3599 @node Substitute Server Authorization
3600 @subsection Substitute Server Authorization
3603 @cindex substitutes, authorization thereof
3604 @cindex access control list (ACL), for substitutes
3605 @cindex ACL (access control list), for substitutes
3606 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3608 must add its public key to the access control list (ACL) of archive
3609 imports, using the @command{guix archive} command (@pxref{Invoking guix
3610 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3611 be compromised and to serve genuine substitutes.
3614 If you are using Guix System, you can skip this section: Guix System
3615 authorizes substitutes from @code{@value{SUBSTITUTE-SERVER}} by default.
3618 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3619 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3620 the installation prefix of Guix. If you installed Guix from source,
3621 make sure you checked the GPG signature of
3622 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3623 Then, you can run something like this:
3626 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3629 Once this is in place, the output of a command like @code{guix build}
3630 should change from something like:
3633 $ guix build emacs --dry-run
3634 The following derivations would be built:
3635 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3636 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3637 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3638 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3646 $ guix build emacs --dry-run
3647 112.3 MB would be downloaded:
3648 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3649 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3650 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3651 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3656 The text changed from ``The following derivations would be built'' to
3657 ``112.3 MB would be downloaded''. This indicates that substitutes from
3658 @code{@value{SUBSTITUTE-SERVER}} are usable and will be downloaded, when
3659 possible, for future builds.
3661 @cindex substitutes, how to disable
3662 The substitute mechanism can be disabled globally by running
3663 @code{guix-daemon} with @option{--no-substitutes} (@pxref{Invoking
3664 guix-daemon}). It can also be disabled temporarily by passing the
3665 @option{--no-substitutes} option to @command{guix package},
3666 @command{guix build}, and other command-line tools.
3668 @node Getting Substitutes from Other Servers
3669 @subsection Getting Substitutes from Other Servers
3671 @cindex substitute servers, adding more
3672 Guix can look up and fetch substitutes from several servers. This is
3673 useful when you are using packages from additional channels for which
3674 the official server does not have substitutes but another server
3675 provides them. Another situation where this is useful is when you would
3676 prefer to download from your organization's substitute server, resorting
3677 to the official server only as a fallback or dismissing it altogether.
3679 You can give Guix a list of substitute server URLs and it will check
3680 them in the specified order. You also need to explicitly authorize the
3681 public keys of substitute servers to instruct Guix to accept the
3682 substitutes they sign.
3684 On Guix System, this is achieved by modifying the configuration of the
3685 @code{guix} service. Since the @code{guix} service is part of the
3686 default lists of services, @code{%base-services} and
3687 @code{%desktop-services}, you can use @code{modify-services} to change
3688 its configuration and add the URLs and substitute keys that you want
3689 (@pxref{Service Reference, @code{modify-services}}).
3691 As an example, suppose you want to fetch substitutes from
3692 @code{guix.example.org} and to authorize the signing key of that server,
3693 in addition to the default @code{@value{SUBSTITUTE-SERVER}}. The
3694 resulting operating system configuration will look something like:
3700 ;; Assume we're starting from '%desktop-services'. Replace it
3701 ;; with the list of services you're actually using.
3702 (modify-services %desktop-services
3703 (guix-service-type config =>
3707 (append (list "https://guix.example.org")
3708 %default-substitute-urls))
3710 (append (list (local-file "./key.pub"))
3711 %default-authorized-guix-keys)))))))
3714 This assumes that the file @file{key.pub} contains the signing key of
3715 @code{guix.example.org}. With this change in place in your operating
3716 system configuration file (say @file{/etc/config.scm}), you can
3717 reconfigure and restart the @code{guix-daemon} service or reboot so the
3718 changes take effect:
3721 $ sudo guix system reconfigure /etc/config.scm
3722 $ sudo herd restart guix-daemon
3725 If you're running Guix on a ``foreign distro'', you would instead take
3726 the following steps to get substitutes from additional servers:
3730 Edit the service configuration file for @code{guix-daemon}; when using
3731 systemd, this is normally
3732 @file{/etc/systemd/system/guix-daemon.service}. Add the
3733 @option{--substitute-urls} option on the @command{guix-daemon} command
3734 line and list the URLs of interest (@pxref{daemon-substitute-urls,
3735 @code{guix-daemon --substitute-urls}}):
3738 @dots{} --substitute-urls='https://guix.example.org https://@value{SUBSTITUTE-SERVER}'
3742 Restart the daemon. For systemd, it goes like this:
3745 systemctl daemon-reload
3746 systemctl restart guix-daemon.service
3750 Authorize the key of the new server (@pxref{Invoking guix archive}):
3753 guix archive --authorize < key.pub
3756 Again this assumes @file{key.pub} contains the public key that
3757 @code{guix.example.org} uses to sign substitutes.
3760 Now you're all set! Substitutes will be preferably taken from
3761 @code{https://guix.example.org}, using @code{@value{SUBSTITUTE-SERVER}}
3762 as a fallback. Of course you can list as many substitute servers as you
3763 like, with the caveat that substitute lookup can be slowed down if too
3764 many servers need to be contacted.
3766 Note that there are also situations where one may want to add the URL of
3767 a substitute server @emph{without} authorizing its key.
3768 @xref{Substitute Authentication}, to understand this fine point.
3770 @node Substitute Authentication
3771 @subsection Substitute Authentication
3773 @cindex digital signatures
3774 Guix detects and raises an error when attempting to use a substitute
3775 that has been tampered with. Likewise, it ignores substitutes that are
3776 not signed, or that are not signed by one of the keys listed in the ACL.
3778 There is one exception though: if an unauthorized server provides
3779 substitutes that are @emph{bit-for-bit identical} to those provided by
3780 an authorized server, then the unauthorized server becomes eligible for
3781 downloads. For example, assume we have chosen two substitute servers
3785 --substitute-urls="https://a.example.org https://b.example.org"
3789 @cindex reproducible builds
3790 If the ACL contains only the key for @samp{b.example.org}, and if
3791 @samp{a.example.org} happens to serve the @emph{exact same} substitutes,
3792 then Guix will download substitutes from @samp{a.example.org} because it
3793 comes first in the list and can be considered a mirror of
3794 @samp{b.example.org}. In practice, independent build machines usually
3795 produce the same binaries, thanks to bit-reproducible builds (see
3798 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3799 (in other words, the server is not authenticated), contrary to what
3800 HTTPS clients such as Web browsers usually do. This is because Guix
3801 authenticates substitute information itself, as explained above, which
3802 is what we care about (whereas X.509 certificates are about
3803 authenticating bindings between domain names and public keys).
3805 @node Proxy Settings
3806 @subsection Proxy Settings
3810 Substitutes are downloaded over HTTP or HTTPS. The @env{http_proxy} and
3811 @env{https_proxy} environment variables can be set in the environment of
3812 @command{guix-daemon} and are honored for downloads of substitutes.
3813 Note that the value of those environment variables in the environment
3814 where @command{guix build}, @command{guix package}, and other client
3815 commands are run has @emph{absolutely no effect}.
3817 @node Substitution Failure
3818 @subsection Substitution Failure
3820 Even when a substitute for a derivation is available, sometimes the
3821 substitution attempt will fail. This can happen for a variety of
3822 reasons: the substitute server might be offline, the substitute may
3823 recently have been deleted, the connection might have been interrupted,
3826 When substitutes are enabled and a substitute for a derivation is
3827 available, but the substitution attempt fails, Guix will attempt to
3828 build the derivation locally depending on whether or not
3829 @option{--fallback} was given (@pxref{fallback-option,, common build
3830 option @option{--fallback}}). Specifically, if @option{--fallback} was
3831 omitted, then no local build will be performed, and the derivation is
3832 considered to have failed. However, if @option{--fallback} was given,
3833 then Guix will attempt to build the derivation locally, and the success
3834 or failure of the derivation depends on the success or failure of the
3835 local build. Note that when substitutes are disabled or no substitute
3836 is available for the derivation in question, a local build will
3837 @emph{always} be performed, regardless of whether or not
3838 @option{--fallback} was given.
3840 To get an idea of how many substitutes are available right now, you can
3841 try running the @command{guix weather} command (@pxref{Invoking guix
3842 weather}). This command provides statistics on the substitutes provided
3845 @node On Trusting Binaries
3846 @subsection On Trusting Binaries
3848 @cindex trust, of pre-built binaries
3849 Today, each individual's control over their own computing is at the
3850 mercy of institutions, corporations, and groups with enough power and
3851 determination to subvert the computing infrastructure and exploit its
3852 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3853 convenient, we encourage users to also build on their own, or even run
3854 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3855 interesting target. One way to help is by publishing the software you
3856 build using @command{guix publish} so that others have one more choice
3857 of server to download substitutes from (@pxref{Invoking guix publish}).
3859 Guix has the foundations to maximize build reproducibility
3860 (@pxref{Features}). In most cases, independent builds of a given
3861 package or derivation should yield bit-identical results. Thus, through
3862 a diverse set of independent package builds, we can strengthen the
3863 integrity of our systems. The @command{guix challenge} command aims to
3864 help users assess substitute servers, and to assist developers in
3865 finding out about non-deterministic package builds (@pxref{Invoking guix
3866 challenge}). Similarly, the @option{--check} option of @command{guix
3867 build} allows users to check whether previously-installed substitutes
3868 are genuine by rebuilding them locally (@pxref{build-check,
3869 @command{guix build --check}}).
3871 In the future, we want Guix to have support to publish and retrieve
3872 binaries to/from other users, in a peer-to-peer fashion. If you would
3873 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3875 @node Packages with Multiple Outputs
3876 @section Packages with Multiple Outputs
3878 @cindex multiple-output packages
3879 @cindex package outputs
3882 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3883 source package leads to exactly one directory in the store. When running
3884 @command{guix install glibc}, one installs the default output of the
3885 GNU libc package; the default output is called @code{out}, but its name
3886 can be omitted as shown in this command. In this particular case, the
3887 default output of @code{glibc} contains all the C header files, shared
3888 libraries, static libraries, Info documentation, and other supporting
3891 Sometimes it is more appropriate to separate the various types of files
3892 produced from a single source package into separate outputs. For
3893 instance, the GLib C library (used by GTK+ and related packages)
3894 installs more than 20 MiB of reference documentation as HTML pages.
3895 To save space for users who do not need it, the documentation goes to a
3896 separate output, called @code{doc}. To install the main GLib output,
3897 which contains everything but the documentation, one would run:
3903 @cindex documentation
3904 The command to install its documentation is:
3907 guix install glib:doc
3910 Some packages install programs with different ``dependency footprints''.
3911 For instance, the WordNet package installs both command-line tools and
3912 graphical user interfaces (GUIs). The former depend solely on the C
3913 library, whereas the latter depend on Tcl/Tk and the underlying X
3914 libraries. In this case, we leave the command-line tools in the default
3915 output, whereas the GUIs are in a separate output. This allows users
3916 who do not need the GUIs to save space. The @command{guix size} command
3917 can help find out about such situations (@pxref{Invoking guix size}).
3918 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3920 There are several such multiple-output packages in the GNU distribution.
3921 Other conventional output names include @code{lib} for libraries and
3922 possibly header files, @code{bin} for stand-alone programs, and
3923 @code{debug} for debugging information (@pxref{Installing Debugging
3924 Files}). The outputs of a packages are listed in the third column of
3925 the output of @command{guix package --list-available} (@pxref{Invoking
3929 @node Invoking guix gc
3930 @section Invoking @command{guix gc}
3932 @cindex garbage collector
3934 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3935 The @command{guix gc} command allows users to explicitly run the garbage
3936 collector to reclaim space from the @file{/gnu/store} directory. It is
3937 the @emph{only} way to remove files from @file{/gnu/store}---removing
3938 files or directories manually may break it beyond repair!
3941 @cindex garbage collector roots
3942 The garbage collector has a set of known @dfn{roots}: any file under
3943 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3944 cannot be deleted; any other file is considered @dfn{dead} and may be
3945 deleted. The set of garbage collector roots (``GC roots'' for short)
3946 includes default user profiles; by default, the symlinks under
3947 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3948 added with @command{guix build --root}, for example (@pxref{Invoking
3949 guix build}). The @command{guix gc --list-roots} command lists them.
3951 Prior to running @code{guix gc --collect-garbage} to make space, it is
3952 often useful to remove old generations from user profiles; that way, old
3953 package builds referenced by those generations can be reclaimed. This
3954 is achieved by running @code{guix package --delete-generations}
3955 (@pxref{Invoking guix package}).
3957 Our recommendation is to run a garbage collection periodically, or when
3958 you are short on disk space. For instance, to guarantee that at least
3959 5@tie{}GB are available on your disk, simply run:
3965 It is perfectly safe to run as a non-interactive periodic job
3966 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3967 Running @command{guix gc} with no arguments will collect as
3968 much garbage as it can, but that is often inconvenient: you may find
3969 yourself having to rebuild or re-download software that is ``dead'' from
3970 the GC viewpoint but that is necessary to build other pieces of
3971 software---e.g., the compiler tool chain.
3973 The @command{guix gc} command has three modes of operation: it can be
3974 used to garbage-collect any dead files (the default), to delete specific
3975 files (the @option{--delete} option), to print garbage-collector
3976 information, or for more advanced queries. The garbage collection
3977 options are as follows:
3980 @item --collect-garbage[=@var{min}]
3981 @itemx -C [@var{min}]
3982 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3983 sub-directories. This is the default operation when no option is
3986 When @var{min} is given, stop once @var{min} bytes have been collected.
3987 @var{min} may be a number of bytes, or it may include a unit as a
3988 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3989 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3991 When @var{min} is omitted, collect all the garbage.
3993 @item --free-space=@var{free}
3994 @itemx -F @var{free}
3995 Collect garbage until @var{free} space is available under
3996 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3997 as @code{500MiB}, as described above.
3999 When @var{free} or more is already available in @file{/gnu/store}, do
4000 nothing and exit immediately.
4002 @item --delete-generations[=@var{duration}]
4003 @itemx -d [@var{duration}]
4004 Before starting the garbage collection process, delete all the generations
4005 older than @var{duration}, for all the user profiles; when run as root, this
4006 applies to all the profiles @emph{of all the users}.
4008 For example, this command deletes all the generations of all your profiles
4009 that are older than 2 months (except generations that are current), and then
4010 proceeds to free space until at least 10 GiB are available:
4013 guix gc -d 2m -F 10G
4018 Attempt to delete all the store files and directories specified as
4019 arguments. This fails if some of the files are not in the store, or if
4020 they are still live.
4022 @item --list-failures
4023 List store items corresponding to cached build failures.
4025 This prints nothing unless the daemon was started with
4026 @option{--cache-failures} (@pxref{Invoking guix-daemon,
4027 @option{--cache-failures}}).
4030 List the GC roots owned by the user; when run as root, list @emph{all} the GC
4034 List store items in use by currently running processes. These store
4035 items are effectively considered GC roots: they cannot be deleted.
4037 @item --clear-failures
4038 Remove the specified store items from the failed-build cache.
4040 Again, this option only makes sense when the daemon is started with
4041 @option{--cache-failures}. Otherwise, it does nothing.
4044 Show the list of dead files and directories still present in the
4045 store---i.e., files and directories no longer reachable from any root.
4048 Show the list of live store files and directories.
4052 In addition, the references among existing store files can be queried:
4058 @cindex package dependencies
4059 List the references (respectively, the referrers) of store files given
4065 List the requisites of the store files passed as arguments. Requisites
4066 include the store files themselves, their references, and the references
4067 of these, recursively. In other words, the returned list is the
4068 @dfn{transitive closure} of the store files.
4070 @xref{Invoking guix size}, for a tool to profile the size of the closure
4071 of an element. @xref{Invoking guix graph}, for a tool to visualize
4072 the graph of references.
4076 Return the derivation(s) leading to the given store items
4077 (@pxref{Derivations}).
4079 For example, this command:
4082 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
4086 returns the @file{.drv} file(s) leading to the @code{emacs} package
4087 installed in your profile.
4089 Note that there may be zero matching @file{.drv} files, for instance
4090 because these files have been garbage-collected. There can also be more
4091 than one matching @file{.drv} due to fixed-output derivations.
4094 Lastly, the following options allow you to check the integrity of the
4095 store and to control disk usage.
4099 @item --verify[=@var{options}]
4100 @cindex integrity, of the store
4101 @cindex integrity checking
4102 Verify the integrity of the store.
4104 By default, make sure that all the store items marked as valid in the
4105 database of the daemon actually exist in @file{/gnu/store}.
4107 When provided, @var{options} must be a comma-separated list containing one
4108 or more of @code{contents} and @code{repair}.
4110 When passing @option{--verify=contents}, the daemon computes the
4111 content hash of each store item and compares it against its hash in the
4112 database. Hash mismatches are reported as data corruptions. Because it
4113 traverses @emph{all the files in the store}, this command can take a
4114 long time, especially on systems with a slow disk drive.
4116 @cindex repairing the store
4117 @cindex corruption, recovering from
4118 Using @option{--verify=repair} or @option{--verify=contents,repair}
4119 causes the daemon to try to repair corrupt store items by fetching
4120 substitutes for them (@pxref{Substitutes}). Because repairing is not
4121 atomic, and thus potentially dangerous, it is available only to the
4122 system administrator. A lightweight alternative, when you know exactly
4123 which items in the store are corrupt, is @command{guix build --repair}
4124 (@pxref{Invoking guix build}).
4127 @cindex deduplication
4128 Optimize the store by hard-linking identical files---this is
4129 @dfn{deduplication}.
4131 The daemon performs deduplication after each successful build or archive
4132 import, unless it was started with @option{--disable-deduplication}
4133 (@pxref{Invoking guix-daemon, @option{--disable-deduplication}}). Thus,
4134 this option is primarily useful when the daemon was running with
4135 @option{--disable-deduplication}.
4139 @node Invoking guix pull
4140 @section Invoking @command{guix pull}
4142 @cindex upgrading Guix
4143 @cindex updating Guix
4144 @cindex @command{guix pull}
4146 @cindex security, @command{guix pull}
4147 @cindex authenticity, of code obtained with @command{guix pull}
4148 Packages are installed or upgraded to the latest version available in
4149 the distribution currently available on your local machine. To update
4150 that distribution, along with the Guix tools, you must run @command{guix
4151 pull}: the command downloads the latest Guix source code and package
4152 descriptions, and deploys it. Source code is downloaded from a
4153 @uref{https://git-scm.com, Git} repository, by default the official
4154 GNU@tie{}Guix repository, though this can be customized. @command{guix
4155 pull} ensures that the code it downloads is @emph{authentic} by
4156 verifying that commits are signed by Guix developers.
4158 Specifically, @command{guix pull} downloads code from the @dfn{channels}
4159 (@pxref{Channels}) specified by one of the followings, in this order:
4163 the @option{--channels} option;
4165 the user's @file{~/.config/guix/channels.scm} file;
4167 the system-wide @file{/etc/guix/channels.scm} file;
4169 the built-in default channels specified in the @code{%default-channels}
4173 On completion, @command{guix package} will use packages and package
4174 versions from this just-retrieved copy of Guix. Not only that, but all
4175 the Guix commands and Scheme modules will also be taken from that latest
4176 version. New @command{guix} sub-commands added by the update also
4179 Any user can update their Guix copy using @command{guix pull}, and the
4180 effect is limited to the user who ran @command{guix pull}. For
4181 instance, when user @code{root} runs @command{guix pull}, this has no
4182 effect on the version of Guix that user @code{alice} sees, and vice
4185 The result of running @command{guix pull} is a @dfn{profile} available
4186 under @file{~/.config/guix/current} containing the latest Guix. Thus,
4187 make sure to add it to the beginning of your search path so that you use
4188 the latest version, and similarly for the Info manual
4189 (@pxref{Documentation}):
4192 export PATH="$HOME/.config/guix/current/bin:$PATH"
4193 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
4196 The @option{--list-generations} or @option{-l} option lists past generations
4197 produced by @command{guix pull}, along with details about their provenance:
4201 Generation 1 Jun 10 2018 00:18:18
4203 repository URL: https://git.savannah.gnu.org/git/guix.git
4204 branch: origin/master
4205 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
4207 Generation 2 Jun 11 2018 11:02:49
4209 repository URL: https://git.savannah.gnu.org/git/guix.git
4210 branch: origin/master
4211 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
4212 2 new packages: keepalived, libnfnetlink
4213 6 packages upgraded: emacs-nix-mode@@2.0.4,
4214 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
4215 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
4217 Generation 3 Jun 13 2018 23:31:07 (current)
4219 repository URL: https://git.savannah.gnu.org/git/guix.git
4220 branch: origin/master
4221 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
4222 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
4223 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
4226 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
4227 describe the current status of Guix.
4229 This @code{~/.config/guix/current} profile works exactly like the profiles
4230 created by @command{guix package} (@pxref{Invoking guix package}). That
4231 is, you can list generations, roll back to the previous
4232 generation---i.e., the previous Guix---and so on:
4235 $ guix pull --roll-back
4236 switched from generation 3 to 2
4237 $ guix pull --delete-generations=1
4238 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
4241 You can also use @command{guix package} (@pxref{Invoking guix package})
4242 to manage the profile by naming it explicitly:
4244 $ guix package -p ~/.config/guix/current --roll-back
4245 switched from generation 3 to 2
4246 $ guix package -p ~/.config/guix/current --delete-generations=1
4247 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
4250 The @command{guix pull} command is usually invoked with no arguments,
4251 but it supports the following options:
4254 @item --url=@var{url}
4255 @itemx --commit=@var{commit}
4256 @itemx --branch=@var{branch}
4257 Download code for the @code{guix} channel from the specified @var{url}, at the
4258 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4259 string), or @var{branch}.
4261 @cindex @file{channels.scm}, configuration file
4262 @cindex configuration file for channels
4263 These options are provided for convenience, but you can also specify your
4264 configuration in the @file{~/.config/guix/channels.scm} file or using the
4265 @option{--channels} option (see below).
4267 @item --channels=@var{file}
4268 @itemx -C @var{file}
4269 Read the list of channels from @var{file} instead of
4270 @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
4271 @var{file} must contain Scheme code that
4272 evaluates to a list of channel objects. @xref{Channels}, for more
4275 @cindex channel news
4278 Display the list of packages added or upgraded since the previous
4279 generation, as well as, occasionally, news written by channel authors
4280 for their users (@pxref{Channels, Writing Channel News}).
4282 The package information is the same as displayed upon @command{guix
4283 pull} completion, but without ellipses; it is also similar to the output
4284 of @command{guix pull -l} for the last generation (see below).
4286 @item --list-generations[=@var{pattern}]
4287 @itemx -l [@var{pattern}]
4288 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
4289 is provided, the subset of generations that match @var{pattern}.
4290 The syntax of @var{pattern} is the same as with @code{guix package
4291 --list-generations} (@pxref{Invoking guix package}).
4294 @cindex rolling back
4295 @cindex undoing transactions
4296 @cindex transactions, undoing
4297 Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
4298 undo the last transaction.
4300 @item --switch-generation=@var{pattern}
4301 @itemx -S @var{pattern}
4303 Switch to a particular generation defined by @var{pattern}.
4305 @var{pattern} may be either a generation number or a number prefixed
4306 with ``+'' or ``-''. The latter means: move forward/backward by a
4307 specified number of generations. For example, if you want to return to
4308 the latest generation after @option{--roll-back}, use
4309 @option{--switch-generation=+1}.
4311 @item --delete-generations[=@var{pattern}]
4312 @itemx -d [@var{pattern}]
4313 When @var{pattern} is omitted, delete all generations except the current
4316 This command accepts the same patterns as @option{--list-generations}.
4317 When @var{pattern} is specified, delete the matching generations. When
4318 @var{pattern} specifies a duration, generations @emph{older} than the
4319 specified duration match. For instance, @option{--delete-generations=1m}
4320 deletes generations that are more than one month old.
4322 If the current generation matches, it is @emph{not} deleted.
4324 Note that deleting generations prevents rolling back to them.
4325 Consequently, this command must be used with care.
4327 @xref{Invoking guix describe}, for a way to display information about the
4328 current generation only.
4330 @item --profile=@var{profile}
4331 @itemx -p @var{profile}
4332 Use @var{profile} instead of @file{~/.config/guix/current}.
4336 Show which channel commit(s) would be used and what would be built or
4337 substituted but do not actually do it.
4339 @item --allow-downgrades
4340 Allow pulling older or unrelated revisions of channels than those
4343 @cindex downgrade attacks, protection against
4344 By default, @command{guix pull} protects against so-called ``downgrade
4345 attacks'' whereby the Git repository of a channel would be reset to an
4346 earlier or unrelated revision of itself, potentially leading you to
4347 install older, known-vulnerable versions of software packages.
4350 Make sure you understand its security implications before using
4351 @option{--allow-downgrades}.
4354 @item --disable-authentication
4355 Allow pulling channel code without authenticating it.
4357 @cindex authentication, of channel code
4358 By default, @command{guix pull} authenticates code downloaded from
4359 channels by verifying that its commits are signed by authorized
4360 developers, and raises an error if this is not the case. This option
4361 instructs it to not perform any such verification.
4364 Make sure you understand its security implications before using
4365 @option{--disable-authentication}.
4368 @item --system=@var{system}
4369 @itemx -s @var{system}
4370 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
4371 the system type of the build host.
4374 Use the bootstrap Guile to build the latest Guix. This option is only
4375 useful to Guix developers.
4378 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
4379 repository and branch to pull from, as well as @emph{additional} repositories
4380 containing package modules that should be deployed. @xref{Channels}, for more
4383 In addition, @command{guix pull} supports all the common build options
4384 (@pxref{Common Build Options}).
4386 @node Invoking guix time-machine
4387 @section Invoking @command{guix time-machine}
4389 @cindex @command{guix time-machine}
4390 @cindex pinning, channels
4391 @cindex replicating Guix
4392 @cindex reproducibility, of Guix
4394 The @command{guix time-machine} command provides access to other
4395 revisions of Guix, for example to install older versions of packages,
4396 or to reproduce a computation in an identical environment. The revision
4397 of Guix to be used is defined by a commit or by a channel
4398 description file created by @command{guix describe}
4399 (@pxref{Invoking guix describe}).
4401 The general syntax is:
4404 guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
4407 where @var{command} and @var{arg}@dots{} are passed unmodified to the
4408 @command{guix} command of the specified revision. The @var{options} that define
4409 this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
4412 @item --url=@var{url}
4413 @itemx --commit=@var{commit}
4414 @itemx --branch=@var{branch}
4415 Use the @code{guix} channel from the specified @var{url}, at the
4416 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4417 string), or @var{branch}.
4419 @item --channels=@var{file}
4420 @itemx -C @var{file}
4421 Read the list of channels from @var{file}. @var{file} must contain
4422 Scheme code that evaluates to a list of channel objects.
4423 @xref{Channels} for more information.
4426 As for @command{guix pull}, the absence of any options means that the
4427 latest commit on the master branch will be used. The command
4430 guix time-machine -- build hello
4433 will thus build the package @code{hello} as defined in the master branch,
4434 which is in general a newer revision of Guix than you have installed.
4435 Time travel works in both directions!
4437 Note that @command{guix time-machine} can trigger builds of channels and
4438 their dependencies, and these are controlled by the standard build
4439 options (@pxref{Common Build Options}).
4444 @c TODO: Remove this once we're more confident about API stability.
4446 The functionality described here is a ``technology preview'' as of version
4447 @value{VERSION}. As such, the interface is subject to change.
4451 @cindex composition of Guix revisions
4452 Sometimes you might need to mix packages from the revision of Guix you're
4453 currently running with packages available in a different revision of Guix.
4454 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
4455 revisions in arbitrary ways.
4457 @cindex inferior packages
4458 Technically, an ``inferior'' is essentially a separate Guix process connected
4459 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4460 @code{(guix inferior)} module allows you to create inferiors and to
4461 communicate with them. It also provides a high-level interface to browse and
4462 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4464 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4465 to interact with a separate revision of Guix. For example, let's assume you
4466 want to install in your profile the current @code{guile} package, along with
4467 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4468 because the newer @code{guile-json} has an incompatible API and you want to
4469 run your code against the old API@. To do that, you could write a manifest for
4470 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4471 manifest, you would create an inferior for that old Guix revision you care
4472 about, and you would look up the @code{guile-json} package in the inferior:
4475 (use-modules (guix inferior) (guix channels)
4476 (srfi srfi-1)) ;for 'first'
4479 ;; This is the old revision from which we want to
4480 ;; extract guile-json.
4483 (url "https://git.savannah.gnu.org/git/guix.git")
4485 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4488 ;; An inferior representing the above revision.
4489 (inferior-for-channels channels))
4491 ;; Now create a manifest with the current "guile" package
4492 ;; and the old "guile-json" package.
4494 (list (first (lookup-inferior-packages inferior "guile-json"))
4495 (specification->package "guile")))
4498 On its first run, @command{guix package --manifest} might have to build the
4499 channel you specified before it can create the inferior; subsequent runs will
4500 be much faster because the Guix revision will be cached.
4502 The @code{(guix inferior)} module provides the following procedures to open an
4505 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4506 [#:cache-directory] [#:ttl]
4507 Return an inferior for @var{channels}, a list of channels. Use the cache at
4508 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4509 This procedure opens a new connection to the build daemon.
4511 As a side effect, this procedure may build or substitute binaries for
4512 @var{channels}, which can take time.
4515 @deffn {Scheme Procedure} open-inferior @var{directory} @
4516 [#:command "bin/guix"]
4517 Open the inferior Guix in @var{directory}, running
4518 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4519 the inferior could not be launched.
4522 @cindex inferior packages
4523 The procedures listed below allow you to obtain and manipulate inferior
4526 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4527 Return the list of packages known to @var{inferior}.
4530 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4532 Return the sorted list of inferior packages matching @var{name} in
4533 @var{inferior}, with highest version numbers first. If @var{version} is true,
4534 return only packages with a version number prefixed by @var{version}.
4537 @deffn {Scheme Procedure} inferior-package? @var{obj}
4538 Return true if @var{obj} is an inferior package.
4541 @deffn {Scheme Procedure} inferior-package-name @var{package}
4542 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4543 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4544 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4545 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4546 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4547 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4548 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4549 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4550 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4551 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4552 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4553 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4554 These procedures are the counterpart of package record accessors
4555 (@pxref{package Reference}). Most of them work by querying the inferior
4556 @var{package} comes from, so the inferior must still be live when you call
4560 Inferior packages can be used transparently like any other package or
4561 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4562 transparently handled by the @code{packages->manifest} procedure, which is
4563 commonly use in manifests (@pxref{Invoking guix package, the
4564 @option{--manifest} option of @command{guix package}}). Thus you can insert
4565 an inferior package pretty much anywhere you would insert a regular package:
4566 in manifests, in the @code{packages} field of your @code{operating-system}
4567 declaration, and so on.
4569 @node Invoking guix describe
4570 @section Invoking @command{guix describe}
4572 @cindex reproducibility
4573 @cindex replicating Guix
4574 Often you may want to answer questions like: ``Which revision of Guix am I
4575 using?'' or ``Which channels am I using?'' This is useful information in many
4576 situations: if you want to @emph{replicate} an environment on a different
4577 machine or user account, if you want to report a bug or to determine what
4578 change in the channels you are using caused it, or if you want to record your
4579 system state for reproducibility purposes. The @command{guix describe}
4580 command answers these questions.
4582 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4583 displays the channel(s) that it was built from, including their repository URL
4584 and commit IDs (@pxref{Channels}):
4588 Generation 10 Sep 03 2018 17:32:44 (current)
4590 repository URL: https://git.savannah.gnu.org/git/guix.git
4592 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4595 If you're familiar with the Git version control system, this is similar in
4596 spirit to @command{git describe}; the output is also similar to that of
4597 @command{guix pull --list-generations}, but limited to the current generation
4598 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4599 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4600 information is all it takes to describe the revision of Guix you're using, and
4601 also to replicate it.
4603 To make it easier to replicate Guix, @command{guix describe} can also be asked
4604 to return a list of channels instead of the human-readable description above:
4607 $ guix describe -f channels
4610 (url "https://git.savannah.gnu.org/git/guix.git")
4612 "e0fa68c7718fffd33d81af415279d6ddb518f727")
4614 (make-channel-introduction
4615 "9edb3f66fd807b096b48283debdcddccfea34bad"
4616 (openpgp-fingerprint
4617 "BBB0 2DDF 2CEA F6A8 0D1D E643 A2A0 6DF2 A33A 54FA")))))
4621 You can save this to a file and feed it to @command{guix pull -C} on some
4622 other machine or at a later point in time, which will instantiate @emph{this
4623 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4624 From there on, since you're able to deploy the same revision of Guix, you can
4625 just as well @emph{replicate a complete software environment}. We humbly
4626 think that this is @emph{awesome}, and we hope you'll like it too!
4628 The details of the options supported by @command{guix describe} are as
4632 @item --format=@var{format}
4633 @itemx -f @var{format}
4634 Produce output in the specified @var{format}, one of:
4638 produce human-readable output;
4640 produce a list of channel specifications that can be passed to @command{guix
4641 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4643 @item channels-sans-intro
4644 like @code{channels}, but omit the @code{introduction} field; use it to
4645 produce a channel specification suitable for Guix version 1.1.0 or
4646 earlier---the @code{introduction} field has to do with channel
4647 authentication (@pxref{Channels, Channel Authentication}) and is not
4648 supported by these older versions;
4651 produce a list of channel specifications in JSON format;
4653 produce a list of channel specifications in Recutils format.
4656 @item --list-formats
4657 Display available formats for @option{--format} option.
4659 @item --profile=@var{profile}
4660 @itemx -p @var{profile}
4661 Display information about @var{profile}.
4664 @node Invoking guix archive
4665 @section Invoking @command{guix archive}
4667 @cindex @command{guix archive}
4669 The @command{guix archive} command allows users to @dfn{export} files
4670 from the store into a single archive, and to later @dfn{import} them on
4671 a machine that runs Guix.
4672 In particular, it allows store files to be transferred from one machine
4673 to the store on another machine.
4676 If you're looking for a way to produce archives in a format suitable for
4677 tools other than Guix, @pxref{Invoking guix pack}.
4680 @cindex exporting store items
4681 To export store files as an archive to standard output, run:
4684 guix archive --export @var{options} @var{specifications}...
4687 @var{specifications} may be either store file names or package
4688 specifications, as for @command{guix package} (@pxref{Invoking guix
4689 package}). For instance, the following command creates an archive
4690 containing the @code{gui} output of the @code{git} package and the main
4691 output of @code{emacs}:
4694 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4697 If the specified packages are not built yet, @command{guix archive}
4698 automatically builds them. The build process may be controlled with the
4699 common build options (@pxref{Common Build Options}).
4701 To transfer the @code{emacs} package to a machine connected over SSH,
4705 guix archive --export -r emacs | ssh the-machine guix archive --import
4709 Similarly, a complete user profile may be transferred from one machine
4710 to another like this:
4713 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4714 ssh the-machine guix archive --import
4718 However, note that, in both examples, all of @code{emacs} and the
4719 profile as well as all of their dependencies are transferred (due to
4720 @option{-r}), regardless of what is already available in the store on
4721 the target machine. The @option{--missing} option can help figure out
4722 which items are missing from the target store. The @command{guix copy}
4723 command simplifies and optimizes this whole process, so this is probably
4724 what you should use in this case (@pxref{Invoking guix copy}).
4726 @cindex nar, archive format
4727 @cindex normalized archive (nar)
4728 @cindex nar bundle, archive format
4729 Each store item is written in the @dfn{normalized archive} or @dfn{nar}
4730 format (described below), and the output of @command{guix archive
4731 --export} (and input of @command{guix archive --import}) is a @dfn{nar
4735 comparable in spirit to `tar', but with differences
4736 that make it more appropriate for our purposes. First, rather than
4737 recording all Unix metadata for each file, the nar format only mentions
4738 the file type (regular, directory, or symbolic link); Unix permissions
4739 and owner/group are dismissed. Second, the order in which directory
4740 entries are stored always follows the order of file names according to
4741 the C locale collation order. This makes archive production fully
4744 That nar bundle format is essentially the concatenation of zero or more
4745 nars along with metadata for each store item it contains: its file name,
4746 references, corresponding derivation, and a digital signature.
4748 When exporting, the daemon digitally signs the contents of the archive,
4749 and that digital signature is appended. When importing, the daemon
4750 verifies the signature and rejects the import in case of an invalid
4751 signature or if the signing key is not authorized.
4752 @c FIXME: Add xref to daemon doc about signatures.
4754 The main options are:
4758 Export the specified store files or packages (see below). Write the
4759 resulting archive to the standard output.
4761 Dependencies are @emph{not} included in the output, unless
4762 @option{--recursive} is passed.
4766 When combined with @option{--export}, this instructs @command{guix archive}
4767 to include dependencies of the given items in the archive. Thus, the
4768 resulting archive is self-contained: it contains the closure of the
4769 exported store items.
4772 Read an archive from the standard input, and import the files listed
4773 therein into the store. Abort if the archive has an invalid digital
4774 signature, or if it is signed by a public key not among the authorized
4775 keys (see @option{--authorize} below).
4778 Read a list of store file names from the standard input, one per line,
4779 and write on the standard output the subset of these files missing from
4782 @item --generate-key[=@var{parameters}]
4783 @cindex signing, archives
4784 Generate a new key pair for the daemon. This is a prerequisite before
4785 archives can be exported with @option{--export}. This
4786 operation is usually instantaneous but it can take time if the system's
4787 entropy pool needs to be refilled. On Guix System,
4788 @code{guix-service-type} takes care of generating this key pair the
4791 The generated key pair is typically stored under @file{/etc/guix}, in
4792 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4793 key, which must be kept secret). When @var{parameters} is omitted,
4794 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4795 versions before 1.6.0, it is a 4096-bit RSA key.
4796 Alternatively, @var{parameters} can specify
4797 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4798 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4799 Libgcrypt Reference Manual}).
4802 @cindex authorizing, archives
4803 Authorize imports signed by the public key passed on standard input.
4804 The public key must be in ``s-expression advanced format''---i.e., the
4805 same format as the @file{signing-key.pub} file.
4807 The list of authorized keys is kept in the human-editable file
4808 @file{/etc/guix/acl}. The file contains
4809 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4810 s-expressions''} and is structured as an access-control list in the
4811 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4814 @item --extract=@var{directory}
4815 @itemx -x @var{directory}
4816 Read a single-item archive as served by substitute servers
4817 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4818 low-level operation needed in only very narrow use cases; see below.
4820 For example, the following command extracts the substitute for Emacs
4821 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4825 https://@value{SUBSTITUTE-SERVER}/nar/gzip/@dots{}-emacs-24.5 \
4826 | gunzip | guix archive -x /tmp/emacs
4829 Single-item archives are different from multiple-item archives produced
4830 by @command{guix archive --export}; they contain a single store item,
4831 and they do @emph{not} embed a signature. Thus this operation does
4832 @emph{no} signature verification and its output should be considered
4835 The primary purpose of this operation is to facilitate inspection of
4836 archive contents coming from possibly untrusted substitute servers
4837 (@pxref{Invoking guix challenge}).
4841 Read a single-item archive as served by substitute servers
4842 (@pxref{Substitutes}) and print the list of files it contains, as in
4847 https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-emacs-26.3 \
4848 | lzip -d | guix archive -t
4853 @c *********************************************************************
4858 @cindex @file{channels.scm}, configuration file
4859 @cindex configuration file for channels
4860 @cindex @command{guix pull}, configuration file
4861 @cindex configuration of @command{guix pull}
4862 Guix and its package collection are updated by running @command{guix pull}
4863 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
4864 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
4865 customized by defining @dfn{channels} in the
4866 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
4867 of a Git repository to be deployed, and @command{guix pull} can be instructed
4868 to pull from one or more channels. In other words, channels can be used
4869 to @emph{customize} and to @emph{extend} Guix, as we will see below.
4870 Guix is able to take into account security concerns and deal with authenticated
4874 * Specifying Additional Channels:: Extending the package collection.
4875 * Using a Custom Guix Channel:: Using a customized Guix.
4876 * Replicating Guix:: Running the @emph{exact same} Guix.
4877 * Channel Authentication:: How Guix verifies what it fetches.
4878 * Creating a Channel:: How to write your custom channel.
4879 * Package Modules in a Sub-directory:: Specifying the channel's package modules location.
4880 * Declaring Channel Dependencies:: How to depend on other channels.
4881 * Specifying Channel Authorizations:: Defining channel authors authorizations.
4882 * Primary URL:: Distinguishing mirror to original.
4883 * Writing Channel News:: Communicating information to channel's users.
4886 @node Specifying Additional Channels
4887 @section Specifying Additional Channels
4889 @cindex extending the package collection (channels)
4890 @cindex variant packages (channels)
4891 You can specify @emph{additional channels} to pull from. To use a channel, write
4892 @code{~/.config/guix/channels.scm} to instruct @command{guix pull} to pull from it
4893 @emph{in addition} to the default Guix channel(s):
4895 @vindex %default-channels
4897 ;; Add variant packages to those Guix provides.
4899 (name 'variant-packages)
4900 (url "https://example.org/variant-packages.git"))
4905 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
4906 add a channel the list of channels that the variable @code{%default-channels}
4907 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
4908 Manual}). With this file in place, @command{guix pull} builds not only Guix
4909 but also the package modules from your own repository. The result in
4910 @file{~/.config/guix/current} is the union of Guix with your own package
4914 $ guix pull --list-generations
4916 Generation 19 Aug 27 2018 16:20:48
4918 repository URL: https://git.savannah.gnu.org/git/guix.git
4920 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
4921 variant-packages dd3df5e
4922 repository URL: https://example.org/variant-packages.git
4924 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
4925 11 new packages: variant-gimp, variant-emacs-with-cool-features, @dots{}
4926 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
4930 The output of @command{guix pull} above shows that Generation@tie{}19 includes
4931 both Guix and packages from the @code{variant-personal-packages} channel. Among
4932 the new and upgraded packages that are listed, some like @code{variant-gimp} and
4933 @code{variant-emacs-with-cool-features} might come from
4934 @code{variant-packages}, while others come from the Guix default channel.
4936 @node Using a Custom Guix Channel
4937 @section Using a Custom Guix Channel
4939 The channel called @code{guix} specifies where Guix itself---its command-line
4940 tools as well as its package collection---should be downloaded. For instance,
4941 suppose you want to update from another copy of the Guix repository at
4942 @code{example.org}, and specifically the @code{super-hacks} branch, you can
4943 write in @code{~/.config/guix/channels.scm} this specification:
4946 ;; Tell 'guix pull' to use another repo.
4949 (url "https://example.org/another-guix.git")
4950 (branch "super-hacks")))
4954 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
4955 branch of the repository at @code{example.org}. The authentication concern is
4956 addressed below ((@pxref{Channel Authentication}).
4958 @node Replicating Guix
4959 @section Replicating Guix
4961 @cindex pinning, channels
4962 @cindex replicating Guix
4963 @cindex reproducibility, of Guix
4964 The @command{guix pull --list-generations} output above shows precisely which
4965 commits were used to build this instance of Guix. We can thus replicate it,
4966 say, on another machine, by providing a channel specification in
4967 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
4970 ;; Deploy specific commits of my channels of interest.
4973 (url "https://git.savannah.gnu.org/git/guix.git")
4974 (commit "6298c3ffd9654d3231a6f25390b056483e8f407c"))
4976 (name 'variant-packages)
4977 (url "https://example.org/variant-packages.git")
4978 (commit "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
4981 The @command{guix describe --format=channels} command can even generate this
4982 list of channels directly (@pxref{Invoking guix describe}). The resulting
4983 file can be used with the -C options of @command{guix pull}
4984 (@pxref{Invoking guix pull}) or @command{guix time-machine}
4985 (@pxref{Invoking guix time-machine}).
4987 At this point the two machines run the @emph{exact same Guix}, with access to
4988 the @emph{exact same packages}. The output of @command{guix build gimp} on
4989 one machine will be exactly the same, bit for bit, as the output of the same
4990 command on the other machine. It also means both machines have access to all
4991 the source code of Guix and, transitively, to all the source code of every
4994 This gives you super powers, allowing you to track the provenance of binary
4995 artifacts with very fine grain, and to reproduce software environments at
4996 will---some sort of ``meta reproducibility'' capabilities, if you will.
4997 @xref{Inferiors}, for another way to take advantage of these super powers.
4999 @node Channel Authentication
5000 @section Channel Authentication
5002 @anchor{channel-authentication}
5003 @cindex authentication, of channel code
5004 The @command{guix pull} and @command{guix time-machine} commands
5005 @dfn{authenticate} the code retrieved from channels: they make sure each
5006 commit that is fetched is signed by an authorized developer. The goal
5007 is to protect from unauthorized modifications to the channel that would
5008 lead users to run malicious code.
5010 As a user, you must provide a @dfn{channel introduction} in your
5011 channels file so that Guix knows how to authenticate its first commit.
5012 A channel specification, including its introduction, looks something
5017 (name 'some-channel)
5018 (url "https://example.org/some-channel.git")
5020 (make-channel-introduction
5021 "6f0d8cc0d88abb59c324b2990bfee2876016bb86"
5022 (openpgp-fingerprint
5023 "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
5026 The specification above shows the name and URL of the channel. The call
5027 to @code{make-channel-introduction} above specifies that authentication
5028 of this channel starts at commit @code{6f0d8cc@dots{}}, which is signed
5029 by the OpenPGP key with fingerprint @code{CABB A931@dots{}}.
5031 For the main channel, called @code{guix}, you automatically get that
5032 information from your Guix installation. For other channels, include
5033 the channel introduction provided by the channel authors in your
5034 @file{channels.scm} file. Make sure you retrieve the channel
5035 introduction from a trusted source since that is the root of your trust.
5037 If you're curious about the authentication mechanics, read on!
5039 @node Creating a Channel
5040 @section Creating a Channel
5042 @cindex personal packages (channels)
5043 @cindex channels, for personal packages
5044 Let's say you have a bunch of custom package variants or personal packages
5045 that you think would make little sense to contribute to the Guix project, but
5046 would like to have these packages transparently available to you at the
5047 command line. You would first write modules containing those package
5048 definitions (@pxref{Package Modules}), maintain them in a Git repository, and
5049 then you and anyone else can use it as an additional channel to get packages
5052 @c What follows stems from discussions at
5053 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
5054 @c earlier discussions on guix-devel@gnu.org.
5056 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
5057 publish your personal channel to the world, we would like to share a few words
5062 Before publishing a channel, please consider contributing your package
5063 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
5064 to free software of all sorts, and packages in Guix proper are readily
5065 available to all Guix users and benefit from the project's quality assurance
5069 When you maintain package definitions outside Guix, we, Guix developers,
5070 consider that @emph{the compatibility burden is on you}. Remember that
5071 package modules and package definitions are just Scheme code that uses various
5072 programming interfaces (APIs). We want to remain free to change these APIs to
5073 keep improving Guix, possibly in ways that break your channel. We never
5074 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
5078 Corollary: if you're using an external channel and that channel breaks, please
5079 @emph{report the issue to the channel authors}, not to the Guix project.
5082 You've been warned! Having said this, we believe external channels are a
5083 practical way to exert your freedom to augment Guix' package collection and to
5084 share your improvements, which are basic tenets of
5085 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
5086 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
5089 To create a channel, create a Git repository containing your own package
5090 modules and make it available. The repository can contain anything, but a
5091 useful channel will contain Guile modules that export packages. Once you
5092 start using a channel, Guix will behave as if the root directory of that
5093 channel's Git repository has been added to the Guile load path (@pxref{Load
5094 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
5095 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
5096 module, then the module will be available under the name @code{(my-packages
5097 my-tools)}, and you will be able to use it like any other module
5098 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
5100 As a channel author, consider bundling authentication material with your
5101 channel so that users can authenticate it. @xref{Channel
5102 Authentication}, and @ref{Specifying Channel Authorizations}, for info
5106 @node Package Modules in a Sub-directory
5107 @section Package Modules in a Sub-directory
5109 @cindex subdirectory, channels
5110 As a channel author, you may want to keep your channel modules in a
5111 sub-directory. If your modules are in the sub-directory @file{guix}, you must
5112 add a meta-data file @file{.guix-channel} that contains:
5120 @node Declaring Channel Dependencies
5121 @section Declaring Channel Dependencies
5123 @cindex dependencies, channels
5124 @cindex meta-data, channels
5125 Channel authors may decide to augment a package collection provided by other
5126 channels. They can declare their channel to be dependent on other channels in
5127 a meta-data file @file{.guix-channel}, which is to be placed in the root of
5128 the channel repository.
5130 The meta-data file should contain a simple S-expression like this:
5137 (name 'some-collection)
5138 (url "https://example.org/first-collection.git")
5140 ;; The 'introduction' bit below is optional: you would
5141 ;; provide it for dependencies that can be authenticated.
5143 (channel-introduction
5145 (commit "a8883b58dc82e167c96506cf05095f37c2c2c6cd")
5146 (signer "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
5148 (name 'some-other-collection)
5149 (url "https://example.org/second-collection.git")
5150 (branch "testing"))))
5153 In the above example this channel is declared to depend on two other channels,
5154 which will both be fetched automatically. The modules provided by the channel
5155 will be compiled in an environment where the modules of all these declared
5156 channels are available.
5158 For the sake of reliability and maintainability, you should avoid dependencies
5159 on channels that you don't control, and you should aim to keep the number of
5160 dependencies to a minimum.
5162 @node Specifying Channel Authorizations
5163 @section Specifying Channel Authorizations
5165 @cindex channel authorizations
5166 @anchor{channel-authorizations}
5167 As we saw above, Guix ensures the source code it pulls from channels
5168 comes from authorized developers. As a channel author, you need to
5169 specify the list of authorized developers in the
5170 @file{.guix-authorizations} file in the channel's Git repository. The
5171 authentication rule is simple: each commit must be signed by a key
5172 listed in the @file{.guix-authorizations} file of its parent
5173 commit(s)@footnote{Git commits form a @dfn{directed acyclic graph}
5174 (DAG). Each commit can have zero or more parents; ``regular'' commits
5175 have one parent and merge commits have two parent commits. Read
5176 @uref{https://eagain.net/articles/git-for-computer-scientists/, @i{Git
5177 for Computer Scientists}} for a great overview.} The
5178 @file{.guix-authorizations} file looks like this:
5181 ;; Example '.guix-authorizations' file.
5184 (version 0) ;current file format version
5186 (("AD17 A21E F8AE D8F1 CC02 DBD9 F8AE D8F1 765C 61E3"
5188 ("2A39 3FFF 68F4 EF7A 3D29 12AF 68F4 EF7A 22FB B2D5"
5190 ("CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"
5194 Each fingerprint is followed by optional key/value pairs, as in the
5195 example above. Currently these key/value pairs are ignored.
5197 This authentication rule creates a chicken-and-egg issue: how do we
5198 authenticate the first commit? Related to that: how do we deal with
5199 channels whose repository history contains unsigned commits and lack
5200 @file{.guix-authorizations}? And how do we fork existing channels?
5202 @cindex channel introduction
5203 Channel introductions answer these questions by describing the first
5204 commit of a channel that should be authenticated. The first time a
5205 channel is fetched with @command{guix pull} or @command{guix
5206 time-machine}, the command looks up the introductory commit and verifies
5207 that it is signed by the specified OpenPGP key. From then on, it
5208 authenticates commits according to the rule above.
5210 Additionally, your channel must provide all the OpenPGP keys that were
5211 ever mentioned in @file{.guix-authorizations}, stored as @file{.key}
5212 files, which can be either binary or ``ASCII-armored''. By default,
5213 those @file{.key} files are searched for in the branch named
5214 @code{keyring} but you can specify a different branch name in
5215 @code{.guix-channel} like so:
5220 (keyring-reference "my-keyring-branch"))
5223 To summarize, as the author of a channel, there are three things you have
5224 to do to allow users to authenticate your code:
5228 Export the OpenPGP keys of past and present committers with @command{gpg
5229 --export} and store them in @file{.key} files, by default in a branch
5230 named @code{keyring} (we recommend making it an @dfn{orphan branch}).
5233 Introduce an initial @file{.guix-authorizations} in the channel's
5234 repository. Do that in a signed commit (@pxref{Commit Access}, for
5235 information on how to sign Git commits.)
5238 Advertise the channel introduction, for instance on your channel's web
5239 page. The channel introduction, as we saw above, is the commit/key
5240 pair---i.e., the commit that introduced @file{.guix-authorizations}, and
5241 the fingerprint of the OpenPGP used to sign it.
5244 Before pushing to your public Git repository, you can run @command{guix
5245 git-authenticate} to verify that you did sign all the commits you are
5246 about to push with an authorized key:
5249 guix git authenticate @var{commit} @var{signer}
5253 where @var{commit} and @var{signer} are your channel introduction.
5254 @xref{Invoking guix git authenticate}, for details.
5256 Publishing a signed channel requires discipline: any mistake, such as an
5257 unsigned commit or a commit signed by an unauthorized key, will prevent
5258 users from pulling from your channel---well, that's the whole point of
5259 authentication! Pay attention to merges in particular: merge commits
5260 are considered authentic if and only if they are signed by a key present
5261 in the @file{.guix-authorizations} file of @emph{both} branches.
5264 @section Primary URL
5266 @cindex primary URL, channels
5267 Channel authors can indicate the primary URL of their channel's Git
5268 repository in the @file{.guix-channel} file, like so:
5273 (url "https://example.org/guix.git"))
5276 This allows @command{guix pull} to determine whether it is pulling code
5277 from a mirror of the channel; when that is the case, it warns the user
5278 that the mirror might be stale and displays the primary URL. That way,
5279 users cannot be tricked into fetching code from a stale mirror that does
5280 not receive security updates.
5282 This feature only makes sense for authenticated repositories, such as
5283 the official @code{guix} channel, for which @command{guix pull} ensures
5284 the code it fetches is authentic.
5286 @node Writing Channel News
5287 @section Writing Channel News
5289 @cindex news, for channels
5290 Channel authors may occasionally want to communicate to their users
5291 information about important changes in the channel. You'd send them all
5292 an email, but that's not convenient.
5294 Instead, channels can provide a @dfn{news file}; when the channel users
5295 run @command{guix pull}, that news file is automatically read and
5296 @command{guix pull --news} can display the announcements that correspond
5297 to the new commits that have been pulled, if any.
5299 To do that, channel authors must first declare the name of the news file
5300 in their @file{.guix-channel} file:
5305 (news-file "etc/news.txt"))
5308 The news file itself, @file{etc/news.txt} in this example, must look
5309 something like this:
5314 (entry (tag "the-bug-fix")
5315 (title (en "Fixed terrible bug")
5317 (body (en "@@emph@{Good news@}! It's fixed!")
5318 (eo "Certe ĝi pli bone funkcias nun!")))
5319 (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
5320 (title (en "Added a great package")
5321 (ca "Què vol dir guix?"))
5322 (body (en "Don't miss the @@code@{hello@} package!"))))
5325 While the news file is using the Scheme syntax, avoid naming it with a
5326 @file{.scm} extension or else it will get picked up when building the
5327 channel and yield an error since it is not a valid module.
5328 Alternatively, you can move the channel module to a subdirectory and
5329 store the news file in another directory.
5331 The file consists of a list of @dfn{news entries}. Each entry is
5332 associated with a commit or tag: it describes changes made in this
5333 commit, possibly in preceding commits as well. Users see entries only
5334 the first time they obtain the commit the entry refers to.
5336 The @code{title} field should be a one-line summary while @code{body}
5337 can be arbitrarily long, and both can contain Texinfo markup
5338 (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
5339 a list of language tag/message tuples, which allows @command{guix pull}
5340 to display news in the language that corresponds to the user's locale.
5342 If you want to translate news using a gettext-based workflow, you can
5343 extract translatable strings with @command{xgettext} (@pxref{xgettext
5344 Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
5345 you write news entries in English first, the command below creates a PO
5346 file containing the strings to translate:
5349 xgettext -o news.po -l scheme -ken etc/news.txt
5352 To sum up, yes, you could use your channel as a blog. But beware, this
5353 is @emph{not quite} what your users might expect.
5356 @c *********************************************************************
5358 @chapter Development
5360 @cindex software development
5361 If you are a software developer, Guix provides tools that you should find
5362 helpful---independently of the language you're developing in. This is what
5363 this chapter is about.
5365 The @command{guix environment} command provides a convenient way to set up
5366 @dfn{development environments} containing all the dependencies and tools
5367 necessary to work on the software package of your choice. The @command{guix
5368 pack} command allows you to create @dfn{application bundles} that can be
5369 easily distributed to users who do not run Guix.
5372 * Invoking guix environment:: Setting up development environments.
5373 * Invoking guix pack:: Creating software bundles.
5374 * The GCC toolchain:: Working with languages supported by GCC.
5375 * Invoking guix git authenticate:: Authenticating Git repositories.
5378 @node Invoking guix environment
5379 @section Invoking @command{guix environment}
5381 @cindex reproducible build environments
5382 @cindex development environments
5383 @cindex @command{guix environment}
5384 @cindex environment, package build environment
5385 The purpose of @command{guix environment} is to assist hackers in
5386 creating reproducible development environments without polluting their
5387 package profile. The @command{guix environment} tool takes one or more
5388 packages, builds all of their inputs, and creates a shell
5389 environment to use them.
5391 The general syntax is:
5394 guix environment @var{options} @var{package}@dots{}
5397 The following example spawns a new shell set up for the development of
5401 guix environment guile
5404 If the needed dependencies are not built yet, @command{guix environment}
5405 automatically builds them. The environment of the new shell is an
5406 augmented version of the environment that @command{guix environment} was
5407 run in. It contains the necessary search paths for building the given
5408 package added to the existing environment variables. To create
5409 a ``pure'' environment, in which the original environment variables have
5410 been unset, use the @option{--pure} option@footnote{Users sometimes
5411 wrongfully augment environment variables such as @env{PATH} in their
5412 @file{~/.bashrc} file. As a consequence, when @command{guix
5413 environment} launches it, Bash may read @file{~/.bashrc}, thereby
5414 introducing ``impurities'' in these environment variables. It is an
5415 error to define such environment variables in @file{.bashrc}; instead,
5416 they should be defined in @file{.bash_profile}, which is sourced only by
5417 log-in shells. @xref{Bash Startup Files,,, bash, The GNU Bash Reference
5418 Manual}, for details on Bash start-up files.}.
5420 @vindex GUIX_ENVIRONMENT
5421 @command{guix environment} defines the @env{GUIX_ENVIRONMENT}
5422 variable in the shell it spawns; its value is the file name of the
5423 profile of this environment. This allows users to, say, define a
5424 specific prompt for development environments in their @file{.bashrc}
5425 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
5428 if [ -n "$GUIX_ENVIRONMENT" ]
5430 export PS1="\u@@\h \w [dev]\$ "
5435 ...@: or to browse the profile:
5438 $ ls "$GUIX_ENVIRONMENT/bin"
5441 Additionally, more than one package may be specified, in which case the
5442 union of the inputs for the given packages are used. For example, the
5443 command below spawns a shell where all of the dependencies of both Guile
5444 and Emacs are available:
5447 guix environment guile emacs
5450 Sometimes an interactive shell session is not desired. An arbitrary
5451 command may be invoked by placing the @code{--} token to separate the
5452 command from the rest of the arguments:
5455 guix environment guile -- make -j4
5458 In other situations, it is more convenient to specify the list of
5459 packages needed in the environment. For example, the following command
5460 runs @command{python} from an environment containing Python@tie{}2.7 and
5464 guix environment --ad-hoc python2-numpy python-2.7 -- python
5467 Furthermore, one might want the dependencies of a package and also some
5468 additional packages that are not build-time or runtime dependencies, but
5469 are useful when developing nonetheless. Because of this, the
5470 @option{--ad-hoc} flag is positional. Packages appearing before
5471 @option{--ad-hoc} are interpreted as packages whose dependencies will be
5472 added to the environment. Packages appearing after are interpreted as
5473 packages that will be added to the environment directly. For example,
5474 the following command creates a Guix development environment that
5475 additionally includes Git and strace:
5478 guix environment --pure guix --ad-hoc git strace
5482 Sometimes it is desirable to isolate the environment as much as
5483 possible, for maximal purity and reproducibility. In particular, when
5484 using Guix on a host distro that is not Guix System, it is desirable to
5485 prevent access to @file{/usr/bin} and other system-wide resources from
5486 the development environment. For example, the following command spawns
5487 a Guile REPL in a ``container'' where only the store and the current
5488 working directory are mounted:
5491 guix environment --ad-hoc --container guile -- guile
5495 The @option{--container} option requires Linux-libre 3.19 or newer.
5498 @cindex certificates
5499 Another typical use case for containers is to run security-sensitive
5500 applications such as a web browser. To run Eolie, we must expose and
5501 share some files and directories; we include @code{nss-certs} and expose
5502 @file{/etc/ssl/certs/} for HTTPS authentication; finally we preserve the
5503 @env{DISPLAY} environment variable since containerized graphical
5504 applications won't display without it.
5507 guix environment --preserve='^DISPLAY$' --container --network \
5508 --expose=/etc/machine-id \
5509 --expose=/etc/ssl/certs/ \
5510 --share=$HOME/.local/share/eolie/=$HOME/.local/share/eolie/ \
5511 --ad-hoc eolie nss-certs dbus -- eolie
5514 The available options are summarized below.
5517 @item --root=@var{file}
5518 @itemx -r @var{file}
5519 @cindex persistent environment
5520 @cindex garbage collector root, for environments
5521 Make @var{file} a symlink to the profile for this environment, and
5522 register it as a garbage collector root.
5524 This is useful if you want to protect your environment from garbage
5525 collection, to make it ``persistent''.
5527 When this option is omitted, the environment is protected from garbage
5528 collection only for the duration of the @command{guix environment}
5529 session. This means that next time you recreate the same environment,
5530 you could have to rebuild or re-download packages. @xref{Invoking guix
5531 gc}, for more on GC roots.
5533 @item --expression=@var{expr}
5534 @itemx -e @var{expr}
5535 Create an environment for the package or list of packages that
5536 @var{expr} evaluates to.
5538 For example, running:
5541 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
5544 starts a shell with the environment for this specific variant of the
5550 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
5553 starts a shell with all the base system packages available.
5555 The above commands only use the default output of the given packages.
5556 To select other outputs, two element tuples can be specified:
5559 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
5562 @item --load=@var{file}
5563 @itemx -l @var{file}
5564 Create an environment for the package or list of packages that the code
5565 within @var{file} evaluates to.
5567 As an example, @var{file} might contain a definition like this
5568 (@pxref{Defining Packages}):
5571 @verbatiminclude environment-gdb.scm
5574 @item --manifest=@var{file}
5575 @itemx -m @var{file}
5576 Create an environment for the packages contained in the manifest object
5577 returned by the Scheme code in @var{file}. This option can be repeated
5578 several times, in which case the manifests are concatenated.
5580 This is similar to the same-named option in @command{guix package}
5581 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
5585 Include all specified packages in the resulting environment, as if an
5586 @i{ad hoc} package were defined with them as inputs. This option is
5587 useful for quickly creating an environment without having to write a
5588 package expression to contain the desired inputs.
5590 For instance, the command:
5593 guix environment --ad-hoc guile guile-sdl -- guile
5596 runs @command{guile} in an environment where Guile and Guile-SDL are
5599 Note that this example implicitly asks for the default output of
5600 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
5601 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
5602 of @code{glib} (@pxref{Packages with Multiple Outputs}).
5604 This option may be composed with the default behavior of @command{guix
5605 environment}. Packages appearing before @option{--ad-hoc} are
5606 interpreted as packages whose dependencies will be added to the
5607 environment, the default behavior. Packages appearing after are
5608 interpreted as packages that will be added to the environment directly.
5611 Unset existing environment variables when building the new environment, except
5612 those specified with @option{--preserve} (see below). This has the effect of
5613 creating an environment in which search paths only contain package inputs.
5615 @item --preserve=@var{regexp}
5616 @itemx -E @var{regexp}
5617 When used alongside @option{--pure}, preserve the environment variables
5618 matching @var{regexp}---in other words, put them on a ``white list'' of
5619 environment variables that must be preserved. This option can be repeated
5623 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
5627 This example runs @command{mpirun} in a context where the only environment
5628 variables defined are @env{PATH}, environment variables whose name starts
5629 with @samp{SLURM}, as well as the usual ``precious'' variables (@env{HOME},
5632 @item --search-paths
5633 Display the environment variable definitions that make up the
5636 @item --system=@var{system}
5637 @itemx -s @var{system}
5638 Attempt to build for @var{system}---e.g., @code{i686-linux}.
5643 Run @var{command} within an isolated container. The current working
5644 directory outside the container is mapped inside the container.
5645 Additionally, unless overridden with @option{--user}, a dummy home
5646 directory is created that matches the current user's home directory, and
5647 @file{/etc/passwd} is configured accordingly.
5649 The spawned process runs as the current user outside the container. Inside
5650 the container, it has the same UID and GID as the current user, unless
5651 @option{--user} is passed (see below).
5655 For containers, share the network namespace with the host system.
5656 Containers created without this flag only have access to the loopback
5659 @item --link-profile
5661 For containers, link the environment profile to @file{~/.guix-profile}
5662 within the container and set @code{GUIX_ENVIRONMENT} to that.
5663 This is equivalent to making @file{~/.guix-profile} a symlink to the
5664 actual profile within the container.
5665 Linking will fail and abort the environment if the directory already
5666 exists, which will certainly be the case if @command{guix environment}
5667 was invoked in the user's home directory.
5669 Certain packages are configured to look in @file{~/.guix-profile} for
5670 configuration files and data;@footnote{For example, the
5671 @code{fontconfig} package inspects @file{~/.guix-profile/share/fonts}
5672 for additional fonts.} @option{--link-profile} allows these programs to
5673 behave as expected within the environment.
5675 @item --user=@var{user}
5676 @itemx -u @var{user}
5677 For containers, use the username @var{user} in place of the current
5678 user. The generated @file{/etc/passwd} entry within the container will
5679 contain the name @var{user}, the home directory will be
5680 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
5681 the UID and GID inside the container are 1000. @var{user}
5682 need not exist on the system.
5684 Additionally, any shared or exposed path (see @option{--share} and
5685 @option{--expose} respectively) whose target is within the current user's
5686 home directory will be remapped relative to @file{/home/USER}; this
5687 includes the automatic mapping of the current working directory.
5690 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
5692 guix environment --container --user=foo \
5693 --expose=$HOME/test \
5694 --expose=/tmp/target=$HOME/target
5697 While this will limit the leaking of user identity through home paths
5698 and each of the user fields, this is only one useful component of a
5699 broader privacy/anonymity solution---not one in and of itself.
5702 For containers, the default behavior is to share the current working
5703 directory with the isolated container and immediately change to that
5704 directory within the container. If this is undesirable,
5705 @option{--no-cwd} will cause the current working directory to @emph{not}
5706 be automatically shared and will change to the user's home directory
5707 within the container instead. See also @option{--user}.
5709 @item --expose=@var{source}[=@var{target}]
5710 @itemx --share=@var{source}[=@var{target}]
5711 For containers, @option{--expose} (resp. @option{--share}) exposes the
5712 file system @var{source} from the host system as the read-only
5713 (resp. writable) file system @var{target} within the container. If
5714 @var{target} is not specified, @var{source} is used as the target mount
5715 point in the container.
5717 The example below spawns a Guile REPL in a container in which the user's
5718 home directory is accessible read-only via the @file{/exchange}
5722 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
5727 @command{guix environment}
5728 also supports all of the common build options that @command{guix
5729 build} supports (@pxref{Common Build Options}) as well as package
5730 transformation options (@pxref{Package Transformation Options}).
5732 @node Invoking guix pack
5733 @section Invoking @command{guix pack}
5735 Occasionally you want to pass software to people who are not (yet!)
5736 lucky enough to be using Guix. You'd tell them to run @command{guix
5737 package -i @var{something}}, but that's not possible in this case. This
5738 is where @command{guix pack} comes in.
5741 If you are looking for ways to exchange binaries among machines that
5742 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
5743 publish}, and @ref{Invoking guix archive}.
5748 @cindex application bundle
5749 @cindex software bundle
5750 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
5751 @dfn{software bundle}: it creates a tarball or some other archive
5752 containing the binaries of the software you're interested in, and all
5753 its dependencies. The resulting archive can be used on any machine that
5754 does not have Guix, and people can run the exact same binaries as those
5755 you have with Guix. The pack itself is created in a bit-reproducible
5756 fashion, so anyone can verify that it really contains the build results
5757 that you pretend to be shipping.
5759 For example, to create a bundle containing Guile, Emacs, Geiser, and all
5760 their dependencies, you can run:
5763 $ guix pack guile emacs geiser
5765 /gnu/store/@dots{}-pack.tar.gz
5768 The result here is a tarball containing a @file{/gnu/store} directory
5769 with all the relevant packages. The resulting tarball contains a
5770 @dfn{profile} with the three packages of interest; the profile is the
5771 same as would be created by @command{guix package -i}. It is this
5772 mechanism that is used to create Guix's own standalone binary tarball
5773 (@pxref{Binary Installation}).
5775 Users of this pack would have to run
5776 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
5777 find inconvenient. To work around it, you can create, say, a
5778 @file{/opt/gnu/bin} symlink to the profile:
5781 guix pack -S /opt/gnu/bin=bin guile emacs geiser
5785 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
5787 @cindex relocatable binaries, with @command{guix pack}
5788 What if the recipient of your pack does not have root privileges on
5789 their machine, and thus cannot unpack it in the root file system? In
5790 that case, you will want to use the @option{--relocatable} option (see
5791 below). This option produces @dfn{relocatable binaries}, meaning they
5792 they can be placed anywhere in the file system hierarchy: in the example
5793 above, users can unpack your tarball in their home directory and
5794 directly run @file{./opt/gnu/bin/guile}.
5796 @cindex Docker, build an image with guix pack
5797 Alternatively, you can produce a pack in the Docker image format using
5798 the following command:
5801 guix pack -f docker -S /bin=bin guile guile-readline
5805 The result is a tarball that can be passed to the @command{docker load}
5806 command, followed by @code{docker run}:
5809 docker load < @var{file}
5810 docker run -ti guile-guile-readline /bin/guile
5814 where @var{file} is the image returned by @var{guix pack}, and
5815 @code{guile-guile-readline} is its ``image tag''. See the
5816 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5817 documentation} for more information.
5819 @cindex Singularity, build an image with guix pack
5820 @cindex SquashFS, build an image with guix pack
5821 Yet another option is to produce a SquashFS image with the following
5825 guix pack -f squashfs bash guile emacs geiser
5829 The result is a SquashFS file system image that can either be mounted or
5830 directly be used as a file system container image with the
5831 @uref{https://www.sylabs.io/docs/, Singularity container execution
5832 environment}, using commands like @command{singularity shell} or
5833 @command{singularity exec}.
5835 Several command-line options allow you to customize your pack:
5838 @item --format=@var{format}
5839 @itemx -f @var{format}
5840 Produce a pack in the given @var{format}.
5842 The available formats are:
5846 This is the default format. It produces a tarball containing all the
5847 specified binaries and symlinks.
5850 This produces a tarball that follows the
5851 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
5852 Docker Image Specification}. The ``repository name'' as it appears in
5853 the output of the @command{docker images} command is computed from
5854 package names passed on the command line or in the manifest file.
5857 This produces a SquashFS image containing all the specified binaries and
5858 symlinks, as well as empty mount points for virtual file systems like
5862 Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
5863 For that reason, @command{guix pack -f squashfs} always implies @code{-S
5864 /bin=bin}. Thus, your @command{guix pack} invocation must always start
5865 with something like:
5868 guix pack -f squashfs bash @dots{}
5871 If you forget the @code{bash} (or similar) package, @command{singularity
5872 run} and @command{singularity exec} will fail with an unhelpful ``no
5873 such file or directory'' message.
5877 @cindex relocatable binaries
5880 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
5881 anywhere in the file system hierarchy and run from there.
5883 When this option is passed once, the resulting binaries require support for
5884 @dfn{user namespaces} in the kernel Linux; when passed
5885 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
5886 PRoot support, can be thought of as the abbreviation of ``Really
5887 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to
5888 other techniques if user namespaces are unavailable, and essentially
5889 work anywhere---see below for the implications.
5891 For example, if you create a pack containing Bash with:
5894 guix pack -RR -S /mybin=bin bash
5898 ...@: you can copy that pack to a machine that lacks Guix, and from your
5899 home directory as a normal user, run:
5907 In that shell, if you type @code{ls /gnu/store}, you'll notice that
5908 @file{/gnu/store} shows up and contains all the dependencies of
5909 @code{bash}, even though the machine actually lacks @file{/gnu/store}
5910 altogether! That is probably the simplest way to deploy Guix-built
5911 software on a non-Guix machine.
5914 By default, relocatable binaries rely on the @dfn{user namespace} feature of
5915 the kernel Linux, which allows unprivileged users to mount or change root.
5916 Old versions of Linux did not support it, and some GNU/Linux distributions
5919 To produce relocatable binaries that work even in the absence of user
5920 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
5921 case, binaries will try user namespace support and fall back to another
5922 @dfn{execution engine} if user namespaces are not supported. The
5923 following execution engines are supported:
5927 Try user namespaces and fall back to PRoot if user namespaces are not
5928 supported (see below).
5931 Try user namespaces and fall back to Fakechroot if user namespaces are
5932 not supported (see below).
5935 Run the program through user namespaces and abort if they are not
5939 Run through PRoot. The @uref{https://proot-me.github.io/, PRoot} program
5940 provides the necessary
5941 support for file system virtualization. It achieves that by using the
5942 @code{ptrace} system call on the running program. This approach has the
5943 advantage to work without requiring special kernel support, but it incurs
5944 run-time overhead every time a system call is made.
5947 Run through Fakechroot. @uref{https://github.com/dex4er/fakechroot/,
5948 Fakechroot} virtualizes file system accesses by intercepting calls to C
5949 library functions such as @code{open}, @code{stat}, @code{exec}, and so
5950 on. Unlike PRoot, it incurs very little overhead. However, it does not
5951 always work: for example, some file system accesses made from within the
5952 C library are not intercepted, and file system accesses made @i{via}
5953 direct syscalls are not intercepted either, leading to erratic behavior.
5956 @vindex GUIX_EXECUTION_ENGINE
5957 When running a wrapped program, you can explicitly request one of the
5958 execution engines listed above by setting the
5959 @env{GUIX_EXECUTION_ENGINE} environment variable accordingly.
5962 @cindex entry point, for Docker images
5963 @item --entry-point=@var{command}
5964 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
5965 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
5966 support it. @var{command} must be relative to the profile contained in the
5969 The entry point specifies the command that tools like @code{docker run} or
5970 @code{singularity run} automatically start by default. For example, you can
5974 guix pack -f docker --entry-point=bin/guile guile
5977 The resulting pack can easily be loaded and @code{docker run} with no extra
5978 arguments will spawn @code{bin/guile}:
5981 docker load -i pack.tar.gz
5982 docker run @var{image-id}
5985 @item --expression=@var{expr}
5986 @itemx -e @var{expr}
5987 Consider the package @var{expr} evaluates to.
5989 This has the same purpose as the same-named option in @command{guix
5990 build} (@pxref{Additional Build Options, @option{--expression} in
5991 @command{guix build}}).
5993 @item --manifest=@var{file}
5994 @itemx -m @var{file}
5995 Use the packages contained in the manifest object returned by the Scheme
5996 code in @var{file}. This option can be repeated several times, in which
5997 case the manifests are concatenated.
5999 This has a similar purpose as the same-named option in @command{guix
6000 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
6001 same manifest files. It allows you to define a collection of packages
6002 once and use it both for creating profiles and for creating archives
6003 for use on machines that do not have Guix installed. Note that you can
6004 specify @emph{either} a manifest file @emph{or} a list of packages,
6007 @item --system=@var{system}
6008 @itemx -s @var{system}
6009 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
6010 the system type of the build host.
6012 @item --target=@var{triplet}
6013 @cindex cross-compilation
6014 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
6015 as @code{"aarch64-linux-gnu"} (@pxref{Specifying target triplets, GNU
6016 configuration triplets,, autoconf, Autoconf}).
6018 @item --compression=@var{tool}
6019 @itemx -C @var{tool}
6020 Compress the resulting tarball using @var{tool}---one of @code{gzip},
6021 @code{zstd}, @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no
6024 @item --symlink=@var{spec}
6025 @itemx -S @var{spec}
6026 Add the symlinks specified by @var{spec} to the pack. This option can
6027 appear several times.
6029 @var{spec} has the form @code{@var{source}=@var{target}}, where
6030 @var{source} is the symlink that will be created and @var{target} is the
6033 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
6034 symlink pointing to the @file{bin} sub-directory of the profile.
6036 @item --save-provenance
6037 Save provenance information for the packages passed on the command line.
6038 Provenance information includes the URL and commit of the channels in use
6041 Provenance information is saved in the
6042 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
6043 usual package metadata---the name and version of each package, their
6044 propagated inputs, and so on. It is useful information to the recipient of
6045 the pack, who then knows how the pack was (supposedly) obtained.
6047 This option is not enabled by default because, like timestamps, provenance
6048 information contributes nothing to the build process. In other words, there
6049 is an infinity of channel URLs and commit IDs that can lead to the same pack.
6050 Recording such ``silent'' metadata in the output thus potentially breaks the
6051 source-to-binary bitwise reproducibility property.
6053 @item --root=@var{file}
6054 @itemx -r @var{file}
6055 @cindex garbage collector root, for packs
6056 Make @var{file} a symlink to the resulting pack, and register it as a garbage
6059 @item --localstatedir
6060 @itemx --profile-name=@var{name}
6061 Include the ``local state directory'', @file{/var/guix}, in the resulting
6062 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
6063 profile---by default @var{name} is @code{guix-profile}, which corresponds to
6064 @file{~root/.guix-profile}.
6066 @file{/var/guix} contains the store database (@pxref{The Store}) as well
6067 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
6068 the pack means that the store is ``complete'' and manageable by Guix;
6069 not providing it pack means that the store is ``dead'': items cannot be
6070 added to it or removed from it after extraction of the pack.
6072 One use case for this is the Guix self-contained binary tarball
6073 (@pxref{Binary Installation}).
6077 Print the name of the derivation that builds the pack.
6080 Use the bootstrap binaries to build the pack. This option is only
6081 useful to Guix developers.
6084 In addition, @command{guix pack} supports all the common build options
6085 (@pxref{Common Build Options}) and all the package transformation
6086 options (@pxref{Package Transformation Options}).
6089 @node The GCC toolchain
6090 @section The GCC toolchain
6094 @cindex linker wrapper
6095 @cindex toolchain, for C development
6096 @cindex toolchain, for Fortran development
6098 If you need a complete toolchain for compiling and linking C or C++
6099 source code, use the @code{gcc-toolchain} package. This package
6100 provides a complete GCC toolchain for C/C++ development, including GCC
6101 itself, the GNU C Library (headers and binaries, plus debugging symbols
6102 in the @code{debug} output), Binutils, and a linker wrapper.
6104 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
6105 passed to the linker, add corresponding @code{-rpath} arguments, and
6106 invoke the actual linker with this new set of arguments. You can instruct the
6107 wrapper to refuse to link against libraries not in the store by setting the
6108 @env{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
6110 The package @code{gfortran-toolchain} provides a complete GCC toolchain
6111 for Fortran development. For other languages, please use
6112 @samp{guix search gcc toolchain} (@pxref{guix-search,, Invoking guix package}).
6115 @node Invoking guix git authenticate
6116 @section Invoking @command{guix git authenticate}
6118 The @command{guix git authenticate} command authenticates a Git checkout
6119 following the same rule as for channels (@pxref{channel-authentication,
6120 channel authentication}). That is, starting from a given commit, it
6121 ensures that all subsequent commits are signed by an OpenPGP key whose
6122 fingerprint appears in the @file{.guix-authorizations} file of its
6125 You will find this command useful if you maintain a channel. But in
6126 fact, this authentication mechanism is useful in a broader context, so
6127 you might want to use it for Git repositories that have nothing to do
6130 The general syntax is:
6133 guix git authenticate @var{commit} @var{signer} [@var{options}@dots{}]
6136 By default, this command authenticates the Git checkout in the current
6137 directory; it outputs nothing and exits with exit code zero on success
6138 and non-zero on failure. @var{commit} above denotes the first commit
6139 where authentication takes place, and @var{signer} is the OpenPGP
6140 fingerprint of public key used to sign @var{commit}. Together, they
6141 form a ``channel introduction'' (@pxref{channel-authentication, channel
6142 introduction}). The options below allow you to fine-tune the process.
6145 @item --repository=@var{directory}
6146 @itemx -r @var{directory}
6147 Open the Git repository in @var{directory} instead of the current
6150 @item --keyring=@var{reference}
6151 @itemx -k @var{reference}
6152 Load OpenPGP keyring from @var{reference}, the reference of a branch
6153 such as @code{origin/keyring} or @code{my-keyring}. The branch must
6154 contain OpenPGP public keys in @file{.key} files, either in binary form
6155 or ``ASCII-armored''. By default the keyring is loaded from the branch
6156 named @code{keyring}.
6159 Display commit signing statistics upon completion.
6161 @item --cache-key=@var{key}
6162 Previously-authenticated commits are cached in a file under
6163 @file{~/.cache/guix/authentication}. This option forces the cache to be
6164 stored in file @var{key} in that directory.
6166 @item --historical-authorizations=@var{file}
6167 By default, any commit whose parent commit(s) lack the
6168 @file{.guix-authorizations} file is considered inauthentic. In
6169 contrast, this option considers the authorizations in @var{file} for any
6170 commit that lacks @file{.guix-authorizations}. The format of @var{file}
6171 is the same as that of @file{.guix-authorizations}
6172 (@pxref{channel-authorizations, @file{.guix-authorizations} format}).
6176 @c *********************************************************************
6177 @node Programming Interface
6178 @chapter Programming Interface
6180 GNU Guix provides several Scheme programming interfaces (APIs) to
6181 define, build, and query packages. The first interface allows users to
6182 write high-level package definitions. These definitions refer to
6183 familiar packaging concepts, such as the name and version of a package,
6184 its build system, and its dependencies. These definitions can then be
6185 turned into concrete build actions.
6187 Build actions are performed by the Guix daemon, on behalf of users. In a
6188 standard setup, the daemon has write access to the store---the
6189 @file{/gnu/store} directory---whereas users do not. The recommended
6190 setup also has the daemon perform builds in chroots, under specific
6191 build users, to minimize interference with the rest of the system.
6194 Lower-level APIs are available to interact with the daemon and the
6195 store. To instruct the daemon to perform a build action, users actually
6196 provide it with a @dfn{derivation}. A derivation is a low-level
6197 representation of the build actions to be taken, and the environment in
6198 which they should occur---derivations are to package definitions what
6199 assembly is to C programs. The term ``derivation'' comes from the fact
6200 that build results @emph{derive} from them.
6202 This chapter describes all these APIs in turn, starting from high-level
6203 package definitions.
6206 * Package Modules:: Packages from the programmer's viewpoint.
6207 * Defining Packages:: Defining new packages.
6208 * Defining Package Variants:: Customizing packages.
6209 * Build Systems:: Specifying how packages are built.
6210 * Build Phases:: Phases of the build process of a package.
6211 * Build Utilities:: Helpers for your package definitions and more.
6212 * The Store:: Manipulating the package store.
6213 * Derivations:: Low-level interface to package derivations.
6214 * The Store Monad:: Purely functional interface to the store.
6215 * G-Expressions:: Manipulating build expressions.
6216 * Invoking guix repl:: Programming Guix in Guile
6219 @node Package Modules
6220 @section Package Modules
6222 From a programming viewpoint, the package definitions of the
6223 GNU distribution are provided by Guile modules in the @code{(gnu packages
6224 @dots{})} name space@footnote{Note that packages under the @code{(gnu
6225 packages @dots{})} module name space are not necessarily ``GNU
6226 packages''. This module naming scheme follows the usual Guile module
6227 naming convention: @code{gnu} means that these modules are distributed
6228 as part of the GNU system, and @code{packages} identifies modules that
6229 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
6230 Reference Manual}). For instance, the @code{(gnu packages emacs)}
6231 module exports a variable named @code{emacs}, which is bound to a
6232 @code{<package>} object (@pxref{Defining Packages}).
6234 The @code{(gnu packages @dots{})} module name space is
6235 automatically scanned for packages by the command-line tools. For
6236 instance, when running @code{guix install emacs}, all the @code{(gnu
6237 packages @dots{})} modules are scanned until one that exports a package
6238 object whose name is @code{emacs} is found. This package search
6239 facility is implemented in the @code{(gnu packages)} module.
6241 @cindex customization, of packages
6242 @cindex package module search path
6243 Users can store package definitions in modules with different
6244 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
6245 name and module name must match. For instance, the @code{(my-packages
6246 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
6247 relative to the load path specified with @option{--load-path} or
6248 @env{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
6249 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
6250 these package definitions visible to the user interfaces:
6254 By adding the directory containing your package modules to the search path
6255 with the @code{-L} flag of @command{guix package} and other commands
6256 (@pxref{Common Build Options}), or by setting the @env{GUIX_PACKAGE_PATH}
6257 environment variable described below.
6260 By defining a @dfn{channel} and configuring @command{guix pull} so that it
6261 pulls from it. A channel is essentially a Git repository containing package
6262 modules. @xref{Channels}, for more information on how to define and use
6266 @env{GUIX_PACKAGE_PATH} works similarly to other search path variables:
6268 @defvr {Environment Variable} GUIX_PACKAGE_PATH
6269 This is a colon-separated list of directories to search for additional
6270 package modules. Directories listed in this variable take precedence
6271 over the own modules of the distribution.
6274 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
6275 each package is built based solely on other packages in the
6276 distribution. The root of this dependency graph is a small set of
6277 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
6278 bootstrap)} module. For more information on bootstrapping,
6279 @pxref{Bootstrapping}.
6281 @node Defining Packages
6282 @section Defining Packages
6284 The high-level interface to package definitions is implemented in the
6285 @code{(guix packages)} and @code{(guix build-system)} modules. As an
6286 example, the package definition, or @dfn{recipe}, for the GNU Hello
6287 package looks like this:
6290 (define-module (gnu packages hello)
6291 #:use-module (guix packages)
6292 #:use-module (guix download)
6293 #:use-module (guix build-system gnu)
6294 #:use-module (guix licenses)
6295 #:use-module (gnu packages gawk))
6297 (define-public hello
6303 (uri (string-append "mirror://gnu/hello/hello-" version
6307 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
6308 (build-system gnu-build-system)
6309 (arguments '(#:configure-flags '("--enable-silent-rules")))
6310 (inputs `(("gawk" ,gawk)))
6311 (synopsis "Hello, GNU world: An example GNU package")
6312 (description "Guess what GNU Hello prints!")
6313 (home-page "https://www.gnu.org/software/hello/")
6318 Without being a Scheme expert, the reader may have guessed the meaning
6319 of the various fields here. This expression binds the variable
6320 @code{hello} to a @code{<package>} object, which is essentially a record
6321 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
6322 This package object can be inspected using procedures found in the
6323 @code{(guix packages)} module; for instance, @code{(package-name hello)}
6324 returns---surprise!---@code{"hello"}.
6326 With luck, you may be able to import part or all of the definition of
6327 the package you are interested in from another repository, using the
6328 @code{guix import} command (@pxref{Invoking guix import}).
6330 In the example above, @code{hello} is defined in a module of its own,
6331 @code{(gnu packages hello)}. Technically, this is not strictly
6332 necessary, but it is convenient to do so: all the packages defined in
6333 modules under @code{(gnu packages @dots{})} are automatically known to
6334 the command-line tools (@pxref{Package Modules}).
6336 There are a few points worth noting in the above package definition:
6340 The @code{source} field of the package is an @code{<origin>} object
6341 (@pxref{origin Reference}, for the complete reference).
6342 Here, the @code{url-fetch} method from @code{(guix download)} is used,
6343 meaning that the source is a file to be downloaded over FTP or HTTP.
6345 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
6346 the GNU mirrors defined in @code{(guix download)}.
6348 The @code{sha256} field specifies the expected SHA256 hash of the file
6349 being downloaded. It is mandatory, and allows Guix to check the
6350 integrity of the file. The @code{(base32 @dots{})} form introduces the
6351 base32 representation of the hash. You can obtain this information with
6352 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
6353 hash} (@pxref{Invoking guix hash}).
6356 When needed, the @code{origin} form can also have a @code{patches} field
6357 listing patches to be applied, and a @code{snippet} field giving a
6358 Scheme expression to modify the source code.
6361 @cindex GNU Build System
6362 The @code{build-system} field specifies the procedure to build the
6363 package (@pxref{Build Systems}). Here, @code{gnu-build-system}
6364 represents the familiar GNU Build System, where packages may be
6365 configured, built, and installed with the usual @code{./configure &&
6366 make && make check && make install} command sequence.
6368 When you start packaging non-trivial software, you may need tools to
6369 manipulate those build phases, manipulate files, and so on. @xref{Build
6370 Utilities}, for more on this.
6373 The @code{arguments} field specifies options for the build system
6374 (@pxref{Build Systems}). Here it is interpreted by
6375 @code{gnu-build-system} as a request run @file{configure} with the
6376 @option{--enable-silent-rules} flag.
6382 What about these quote (@code{'}) characters? They are Scheme syntax to
6383 introduce a literal list; @code{'} is synonymous with @code{quote}.
6384 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
6385 for details. Here the value of the @code{arguments} field is a list of
6386 arguments passed to the build system down the road, as with @code{apply}
6387 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
6390 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
6391 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
6392 @code{#:configure-flags} is a keyword used to pass a keyword argument
6393 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
6397 The @code{inputs} field specifies inputs to the build process---i.e.,
6398 build-time or run-time dependencies of the package. Here, we define an
6399 input called @code{"gawk"} whose value is that of the @code{gawk}
6400 variable; @code{gawk} is itself bound to a @code{<package>} object.
6402 @cindex backquote (quasiquote)
6405 @cindex comma (unquote)
6409 @findex unquote-splicing
6410 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
6411 us to introduce a literal list in the @code{inputs} field, while
6412 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
6413 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
6416 Note that GCC, Coreutils, Bash, and other essential tools do not need to
6417 be specified as inputs here. Instead, @code{gnu-build-system} takes care
6418 of ensuring that they are present (@pxref{Build Systems}).
6420 However, any other dependencies need to be specified in the
6421 @code{inputs} field. Any dependency not specified here will simply be
6422 unavailable to the build process, possibly leading to a build failure.
6425 @xref{package Reference}, for a full description of possible fields.
6427 Once a package definition is in place, the
6428 package may actually be built using the @code{guix build} command-line
6429 tool (@pxref{Invoking guix build}), troubleshooting any build failures
6430 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
6431 package definition using the @command{guix edit} command
6432 (@pxref{Invoking guix edit}).
6433 @xref{Packaging Guidelines}, for
6434 more information on how to test package definitions, and
6435 @ref{Invoking guix lint}, for information on how to check a definition
6436 for style conformance.
6437 @vindex GUIX_PACKAGE_PATH
6438 Lastly, @pxref{Channels}, for information
6439 on how to extend the distribution by adding your own package definitions
6442 Finally, updating the package definition to a new upstream version
6443 can be partly automated by the @command{guix refresh} command
6444 (@pxref{Invoking guix refresh}).
6446 Behind the scenes, a derivation corresponding to the @code{<package>}
6447 object is first computed by the @code{package-derivation} procedure.
6448 That derivation is stored in a @file{.drv} file under @file{/gnu/store}.
6449 The build actions it prescribes may then be realized by using the
6450 @code{build-derivations} procedure (@pxref{The Store}).
6452 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
6453 Return the @code{<derivation>} object of @var{package} for @var{system}
6454 (@pxref{Derivations}).
6456 @var{package} must be a valid @code{<package>} object, and @var{system}
6457 must be a string denoting the target system type---e.g.,
6458 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
6459 must be a connection to the daemon, which operates on the store
6460 (@pxref{The Store}).
6464 @cindex cross-compilation
6465 Similarly, it is possible to compute a derivation that cross-builds a
6466 package for some other system:
6468 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
6469 @var{package} @var{target} [@var{system}]
6470 Return the @code{<derivation>} object of @var{package} cross-built from
6471 @var{system} to @var{target}.
6473 @var{target} must be a valid GNU triplet denoting the target hardware
6474 and operating system, such as @code{"aarch64-linux-gnu"}
6475 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
6478 Once you have package definitions, you can easily define @emph{variants}
6479 of those packages. @xref{Defining Package Variants}, for more on that.
6482 * package Reference:: The package data type.
6483 * origin Reference:: The origin data type.
6487 @node package Reference
6488 @subsection @code{package} Reference
6490 This section summarizes all the options available in @code{package}
6491 declarations (@pxref{Defining Packages}).
6493 @deftp {Data Type} package
6494 This is the data type representing a package recipe.
6498 The name of the package, as a string.
6500 @item @code{version}
6501 The version of the package, as a string.
6504 An object telling how the source code for the package should be
6505 acquired. Most of the time, this is an @code{origin} object, which
6506 denotes a file fetched from the Internet (@pxref{origin Reference}). It
6507 can also be any other ``file-like'' object such as a @code{local-file},
6508 which denotes a file from the local file system (@pxref{G-Expressions,
6509 @code{local-file}}).
6511 @item @code{build-system}
6512 The build system that should be used to build the package (@pxref{Build
6515 @item @code{arguments} (default: @code{'()})
6516 The arguments that should be passed to the build system. This is a
6517 list, typically containing sequential keyword-value pairs.
6519 @item @code{inputs} (default: @code{'()})
6520 @itemx @code{native-inputs} (default: @code{'()})
6521 @itemx @code{propagated-inputs} (default: @code{'()})
6522 @cindex inputs, of packages
6523 These fields list dependencies of the package. Each one is a list of
6524 tuples, where each tuple has a label for the input (a string) as its
6525 first element, a package, origin, or derivation as its second element,
6526 and optionally the name of the output thereof that should be used, which
6527 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
6528 more on package outputs). For example, the list below specifies three
6532 `(("libffi" ,libffi)
6533 ("libunistring" ,libunistring)
6534 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
6537 @cindex cross compilation, package dependencies
6538 The distinction between @code{native-inputs} and @code{inputs} is
6539 necessary when considering cross-compilation. When cross-compiling,
6540 dependencies listed in @code{inputs} are built for the @emph{target}
6541 architecture; conversely, dependencies listed in @code{native-inputs}
6542 are built for the architecture of the @emph{build} machine.
6544 @code{native-inputs} is typically used to list tools needed at
6545 build time, but not at run time, such as Autoconf, Automake, pkg-config,
6546 Gettext, or Bison. @command{guix lint} can report likely mistakes in
6547 this area (@pxref{Invoking guix lint}).
6549 @anchor{package-propagated-inputs}
6550 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
6551 specified packages will be automatically installed to profiles
6552 (@pxref{Features, the role of profiles in Guix}) alongside the package
6553 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
6554 package}}, for information on how @command{guix package} deals with
6557 For example this is necessary when packaging a C/C++ library that needs
6558 headers of another library to compile, or when a pkg-config file refers
6559 to another one @i{via} its @code{Requires} field.
6561 Another example where @code{propagated-inputs} is useful is for languages
6562 that lack a facility to record the run-time search path akin to the
6563 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
6564 more. When packaging libraries written in those languages, ensure they
6565 can find library code they depend on at run time by listing run-time
6566 dependencies in @code{propagated-inputs} rather than @code{inputs}.
6568 @item @code{outputs} (default: @code{'("out")})
6569 The list of output names of the package. @xref{Packages with Multiple
6570 Outputs}, for typical uses of additional outputs.
6572 @item @code{native-search-paths} (default: @code{'()})
6573 @itemx @code{search-paths} (default: @code{'()})
6574 A list of @code{search-path-specification} objects describing
6575 search-path environment variables honored by the package.
6577 @item @code{replacement} (default: @code{#f})
6578 This must be either @code{#f} or a package object that will be used as a
6579 @dfn{replacement} for this package. @xref{Security Updates, grafts},
6582 @item @code{synopsis}
6583 A one-line description of the package.
6585 @item @code{description}
6586 A more elaborate description of the package.
6588 @item @code{license}
6589 @cindex license, of packages
6590 The license of the package; a value from @code{(guix licenses)},
6591 or a list of such values.
6593 @item @code{home-page}
6594 The URL to the home-page of the package, as a string.
6596 @item @code{supported-systems} (default: @code{%supported-systems})
6597 The list of systems supported by the package, as strings of the form
6598 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
6600 @item @code{location} (default: source location of the @code{package} form)
6601 The source location of the package. It is useful to override this when
6602 inheriting from another package, in which case this field is not
6603 automatically corrected.
6607 @deffn {Scheme Syntax} this-package
6608 When used in the @emph{lexical scope} of a package field definition, this
6609 identifier resolves to the package being defined.
6611 The example below shows how to add a package as a native input of itself when
6619 ;; When cross-compiled, Guile, for example, depends on
6620 ;; a native version of itself. Add it here.
6621 (native-inputs (if (%current-target-system)
6622 `(("self" ,this-package))
6626 It is an error to refer to @code{this-package} outside a package definition.
6629 Because packages are regular Scheme objects that capture a complete
6630 dependency graph and associated build procedures, it is often useful to
6631 write procedures that take a package and return a modified version
6632 thereof according to some parameters. Below are a few examples.
6634 @cindex tool chain, choosing a package's tool chain
6635 @deffn {Scheme Procedure} package-with-c-toolchain @var{package} @var{toolchain}
6636 Return a variant of @var{package} that uses @var{toolchain} instead of
6637 the default GNU C/C++ toolchain. @var{toolchain} must be a list of
6638 inputs (label/package tuples) providing equivalent functionality, such
6639 as the @code{gcc-toolchain} package.
6641 The example below returns a variant of the @code{hello} package built
6642 with GCC@tie{}10.x and the rest of the GNU tool chain (Binutils and the
6643 GNU C Library) instead of the default tool chain:
6646 (let ((toolchain (specification->package "gcc-toolchain@@10")))
6647 (package-with-c-toolchain hello `(("toolchain" ,toolchain))))
6650 The build tool chain is part of the @dfn{implicit inputs} of
6651 packages---it's usually not listed as part of the various ``inputs''
6652 fields and is instead pulled in by the build system. Consequently, this
6653 procedure works by changing the build system of @var{package} so that it
6654 pulls in @var{toolchain} instead of the defaults. @ref{Build Systems},
6655 for more on build systems.
6658 @node origin Reference
6659 @subsection @code{origin} Reference
6661 This section documents @dfn{origins}. An @code{origin} declaration
6662 specifies data that must be ``produced''---downloaded, usually---and
6663 whose content hash is known in advance. Origins are primarily used to
6664 represent the source code of packages (@pxref{Defining Packages}). For
6665 that reason, the @code{origin} form allows you to declare patches to
6666 apply to the original source code as well as code snippets to modify it.
6668 @deftp {Data Type} origin
6669 This is the data type representing a source code origin.
6673 An object containing the URI of the source. The object type depends on
6674 the @code{method} (see below). For example, when using the
6675 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
6676 values are: a URL represented as a string, or a list thereof.
6678 @cindex fixed-output derivations, for download
6680 A monadic procedure that handles the given URI. The procedure must
6681 accept at least three arguments: the value of the @code{uri} field and
6682 the hash algorithm and hash value specified by the @code{hash} field.
6683 It must return a store item or a derivation in the store monad
6684 (@pxref{The Store Monad}); most methods return a fixed-output derivation
6685 (@pxref{Derivations}).
6687 Commonly used methods include @code{url-fetch}, which fetches data from
6688 a URL, and @code{git-fetch}, which fetches data from a Git repository
6692 A bytevector containing the SHA-256 hash of the source. This is
6693 equivalent to providing a @code{content-hash} SHA256 object in the
6694 @code{hash} field described below.
6697 The @code{content-hash} object of the source---see below for how to use
6698 @code{content-hash}.
6700 You can obtain this information using @code{guix download}
6701 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
6704 @item @code{file-name} (default: @code{#f})
6705 The file name under which the source code should be saved. When this is
6706 @code{#f}, a sensible default value will be used in most cases. In case
6707 the source is fetched from a URL, the file name from the URL will be
6708 used. For version control checkouts, it is recommended to provide the
6709 file name explicitly because the default is not very descriptive.
6711 @item @code{patches} (default: @code{'()})
6712 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
6713 file-like objects}) pointing to patches to be applied to the source.
6715 This list of patches must be unconditional. In particular, it cannot
6716 depend on the value of @code{%current-system} or
6717 @code{%current-target-system}.
6719 @item @code{snippet} (default: @code{#f})
6720 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
6721 in the source directory. This is a convenient way to modify the source,
6722 sometimes more convenient than a patch.
6724 @item @code{patch-flags} (default: @code{'("-p1")})
6725 A list of command-line flags that should be passed to the @code{patch}
6728 @item @code{patch-inputs} (default: @code{#f})
6729 Input packages or derivations to the patching process. When this is
6730 @code{#f}, the usual set of inputs necessary for patching are provided,
6731 such as GNU@tie{}Patch.
6733 @item @code{modules} (default: @code{'()})
6734 A list of Guile modules that should be loaded during the patching
6735 process and while running the code in the @code{snippet} field.
6737 @item @code{patch-guile} (default: @code{#f})
6738 The Guile package that should be used in the patching process. When
6739 this is @code{#f}, a sensible default is used.
6743 @deftp {Data Type} content-hash @var{value} [@var{algorithm}]
6744 Construct a content hash object for the given @var{algorithm}, and with
6745 @var{value} as its hash value. When @var{algorithm} is omitted, assume
6746 it is @code{sha256}.
6748 @var{value} can be a literal string, in which case it is base32-decoded,
6749 or it can be a bytevector.
6751 The following forms are all equivalent:
6754 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj")
6755 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"
6757 (content-hash (base32
6758 "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"))
6759 (content-hash (base64 "kkb+RPaP7uyMZmu4eXPVkM4BN8yhRd8BTHLslb6f/Rc=")
6763 Technically, @code{content-hash} is currently implemented as a macro.
6764 It performs sanity checks at macro-expansion time, when possible, such
6765 as ensuring that @var{value} has the right size for @var{algorithm}.
6768 As we have seen above, how exactly the data an origin refers to is
6769 retrieved is determined by its @code{method} field. The @code{(guix
6770 download)} module provides the most common method, @code{url-fetch},
6773 @deffn {Scheme Procedure} url-fetch @var{url} @var{hash-algo} @var{hash} @
6774 [name] [#:executable? #f]
6775 Return a fixed-output derivation that fetches data from @var{url} (a
6776 string, or a list of strings denoting alternate URLs), which is expected
6777 to have hash @var{hash} of type @var{hash-algo} (a symbol). By default,
6778 the file name is the base name of URL; optionally, @var{name} can
6779 specify a different file name. When @var{executable?} is true, make the
6780 downloaded file executable.
6782 When one of the URL starts with @code{mirror://}, then its host part is
6783 interpreted as the name of a mirror scheme, taken from @file{%mirror-file}.
6785 Alternatively, when URL starts with @code{file://}, return the
6786 corresponding file name in the store.
6789 Likewise, the @code{(guix git-download)} module defines the
6790 @code{git-fetch} origin method, which fetches data from a Git version
6791 control repository, and the @code{git-reference} data type to describe
6792 the repository and revision to fetch.
6794 @deffn {Scheme Procedure} git-fetch @var{ref} @var{hash-algo} @var{hash}
6795 Return a fixed-output derivation that fetches @var{ref}, a
6796 @code{<git-reference>} object. The output is expected to have recursive
6797 hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
6798 the file name, or a generic name if @code{#f}.
6801 @deftp {Data Type} git-reference
6802 This data type represents a Git reference for @code{git-fetch} to
6807 The URL of the Git repository to clone.
6810 This string denotes either the commit to fetch (a hexadecimal string,
6811 either the full SHA1 commit or a ``short'' commit string; the latter is
6812 not recommended) or the tag to fetch.
6814 @item @code{recursive?} (default: @code{#f})
6815 This Boolean indicates whether to recursively fetch Git sub-modules.
6818 The example below denotes the @code{v2.10} tag of the GNU@tie{}Hello
6823 (url "https://git.savannah.gnu.org/git/hello.git")
6827 This is equivalent to the reference below, which explicitly names the
6832 (url "https://git.savannah.gnu.org/git/hello.git")
6833 (commit "dc7dc56a00e48fe6f231a58f6537139fe2908fb9"))
6837 For Mercurial repositories, the module @code{(guix hg-download)} defines
6838 the @code{hg-fetch} origin method and @code{hg-reference} data type for
6839 support of the Mercurial version control system.
6841 @deffn {Scheme Procedure} hg-fetch @var{ref} @var{hash-algo} @var{hash} @
6843 Return a fixed-output derivation that fetches @var{ref}, a
6844 @code{<hg-reference>} object. The output is expected to have recursive
6845 hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
6846 the file name, or a generic name if @code{#false}.
6849 @node Defining Package Variants
6850 @section Defining Package Variants
6852 @cindex customizing packages
6853 @cindex variants, of packages
6854 One of the nice things with Guix is that, given a package definition,
6855 you can easily @emph{derive} variants of that package---for a different
6856 upstream version, with different dependencies, different compilation
6857 options, and so on. Some of these custom packages can be defined
6858 straight from the command line (@pxref{Package Transformation Options}).
6859 This section describes how to define package variants in code. This can
6860 be useful in ``manifests'' (@pxref{profile-manifest,
6861 @option{--manifest}}) and in your own package collection
6862 (@pxref{Creating a Channel}), among others!
6864 @cindex inherit, for package definitions
6865 As discussed earlier, packages are first-class objects in the Scheme
6866 language. The @code{(guix packages)} module provides the @code{package}
6867 construct to define new package objects (@pxref{package Reference}).
6868 The easiest way to define a package variant is using the @code{inherit}
6869 keyword together with @code{package}. This allows you to inherit from a
6870 package definition while overriding the fields you want.
6872 For example, given the @code{hello} variable, which contains a
6873 definition for the current version of GNU@tie{}Hello, here's how you
6874 would define a variant for version 2.2 (released in 2006, it's
6878 (use-modules (gnu packages base)) ;for 'hello'
6886 (uri (string-append "mirror://gnu/hello/hello-" version
6890 "0lappv4slgb5spyqbh6yl5r013zv72yqg2pcl30mginf3wdqd8k9"))))))
6893 The example above corresponds to what the @option{--with-source} package
6894 transformation option does. Essentially @code{hello-2.2} preserves all
6895 the fields of @code{hello}, except @code{version} and @code{source},
6896 which it overrides. Note that the original @code{hello} variable is
6897 still there, in the @code{(gnu packages base)} module, unchanged. When
6898 you define a custom package like this, you are really @emph{adding} a
6899 new package definition; the original one remains available.
6901 You can just as well define variants with a different set of
6902 dependencies than the original package. For example, the default
6903 @code{gdb} package depends on @code{guile}, but since that is an
6904 optional dependency, you can define a variant that removes that
6908 (use-modules (gnu packages gdb) ;for 'gdb'
6909 (srfi srfi-1)) ;for 'alist-delete'
6911 (define gdb-sans-guile
6914 (inputs (alist-delete "guile"
6915 (package-inputs gdb)))))
6918 The @code{alist-delete} call above removes the tuple from the
6919 @code{inputs} field that has @code{"guile"} as its first element
6920 (@pxref{SRFI-1 Association Lists,,, guile, GNU Guile Reference
6923 In some cases, you may find it useful to write functions
6924 (``procedures'', in Scheme parlance) that return a package based on some
6925 parameters. For example, consider the @code{luasocket} library for the
6926 Lua programming language. We want to create @code{luasocket} packages
6927 for major versions of Lua. One way to do that is to define a procedure
6928 that takes a Lua package and returns a @code{luasocket} package that
6932 (define (make-lua-socket name lua)
6933 ;; Return a luasocket package built with LUA.
6937 ;; several fields omitted
6940 (synopsis "Socket library for Lua")))
6942 (define-public lua5.1-socket
6943 (make-lua-socket "lua5.1-socket" lua-5.1))
6945 (define-public lua5.2-socket
6946 (make-lua-socket "lua5.2-socket" lua-5.2))
6949 Here we have defined packages @code{lua5.1-socket} and
6950 @code{lua5.2-socket} by calling @code{make-lua-socket} with different
6951 arguments. @xref{Procedures,,, guile, GNU Guile Reference Manual}, for
6952 more info on procedures. Having top-level public definitions for these
6953 two packages means that they can be referred to from the command line
6954 (@pxref{Package Modules}).
6956 @cindex package transformations
6957 These are pretty simple package variants. As a convenience, the
6958 @code{(guix transformations)} module provides a high-level interface
6959 that directly maps to the more sophisticated package transformation
6960 options (@pxref{Package Transformation Options}):
6962 @deffn {Scheme Procedure} options->transformation @var{opts}
6963 Return a procedure that, when passed an object to build (package,
6964 derivation, etc.), applies the transformations specified by @var{opts} and returns
6965 the resulting objects. @var{opts} must be a list of symbol/string pairs such as:
6968 ((with-branch . "guile-gcrypt=master")
6969 (without-tests . "libgcrypt"))
6972 Each symbol names a transformation and the corresponding string is an argument
6973 to that transformation.
6976 For instance, a manifest equivalent to this command:
6980 --with-branch=guile-gcrypt=master \
6981 --with-debug-info=zlib
6985 ... would look like this:
6988 (use-modules (guix transformations))
6991 ;; The package transformation procedure.
6992 (options->transformation
6993 '((with-branch . "guile-gcrypt=master")
6994 (with-debug-info . "zlib"))))
6997 (list (transform (specification->package "guix"))))
7000 @cindex input rewriting
7001 @cindex dependency graph rewriting
7002 The @code{options->transformation} procedure is convenient, but it's
7003 perhaps also not as flexible as you may like. How is it implemented?
7004 The astute reader probably noticed that most package transformation
7005 options go beyond the superficial changes shown in the first examples of
7006 this section: they involve @dfn{input rewriting}, whereby the dependency
7007 graph of a package is rewritten by replacing specific inputs by others.
7009 Dependency graph rewriting, for the purposes of swapping packages in the
7010 graph, is what the @code{package-input-rewriting} procedure in
7011 @code{(guix packages)} implements.
7013 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
7014 [@var{rewrite-name}] [#:deep? #t]
7015 Return a procedure that, when passed a package, replaces its direct and
7016 indirect dependencies, including implicit inputs when @var{deep?} is
7017 true, according to @var{replacements}. @var{replacements} is a list of
7018 package pairs; the first element of each pair is the package to replace,
7019 and the second one is the replacement.
7021 Optionally, @var{rewrite-name} is a one-argument procedure that takes
7022 the name of a package and returns its new name after rewrite.
7026 Consider this example:
7029 (define libressl-instead-of-openssl
7030 ;; This is a procedure to replace OPENSSL by LIBRESSL,
7032 (package-input-rewriting `((,openssl . ,libressl))))
7034 (define git-with-libressl
7035 (libressl-instead-of-openssl git))
7039 Here we first define a rewriting procedure that replaces @var{openssl}
7040 with @var{libressl}. Then we use it to define a @dfn{variant} of the
7041 @var{git} package that uses @var{libressl} instead of @var{openssl}.
7042 This is exactly what the @option{--with-input} command-line option does
7043 (@pxref{Package Transformation Options, @option{--with-input}}).
7045 The following variant of @code{package-input-rewriting} can match packages to
7046 be replaced by name rather than by identity.
7048 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements} [#:deep? #t]
7049 Return a procedure that, given a package, applies the given
7050 @var{replacements} to all the package graph, including implicit inputs
7051 unless @var{deep?} is false. @var{replacements} is a list of
7052 spec/procedures pair; each spec is a package specification such as
7053 @code{"gcc"} or @code{"guile@@2"}, and each procedure takes a matching
7054 package and returns a replacement for that package.
7057 The example above could be rewritten this way:
7060 (define libressl-instead-of-openssl
7061 ;; Replace all the packages called "openssl" with LibreSSL.
7062 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
7065 The key difference here is that, this time, packages are matched by spec and
7066 not by identity. In other words, any package in the graph that is called
7067 @code{openssl} will be replaced.
7069 A more generic procedure to rewrite a package dependency graph is
7070 @code{package-mapping}: it supports arbitrary changes to nodes in the
7073 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}] [#:deep? #f]
7074 Return a procedure that, given a package, applies @var{proc} to all the packages
7075 depended on and returns the resulting package. The procedure stops recursion
7076 when @var{cut?} returns true for a given package. When @var{deep?} is true, @var{proc} is
7077 applied to implicit inputs as well.
7082 @section Build Systems
7084 @cindex build system
7085 Each package definition specifies a @dfn{build system} and arguments for
7086 that build system (@pxref{Defining Packages}). This @code{build-system}
7087 field represents the build procedure of the package, as well as implicit
7088 dependencies of that build procedure.
7090 Build systems are @code{<build-system>} objects. The interface to
7091 create and manipulate them is provided by the @code{(guix build-system)}
7092 module, and actual build systems are exported by specific modules.
7094 @cindex bag (low-level package representation)
7095 Under the hood, build systems first compile package objects to
7096 @dfn{bags}. A @dfn{bag} is like a package, but with less
7097 ornamentation---in other words, a bag is a lower-level representation of
7098 a package, which includes all the inputs of that package, including some
7099 that were implicitly added by the build system. This intermediate
7100 representation is then compiled to a derivation (@pxref{Derivations}).
7101 The @code{package-with-c-toolchain} is an example of a way to change the
7102 implicit inputs that a package's build system pulls in (@pxref{package
7103 Reference, @code{package-with-c-toolchain}}).
7105 Build systems accept an optional list of @dfn{arguments}. In package
7106 definitions, these are passed @i{via} the @code{arguments} field
7107 (@pxref{Defining Packages}). They are typically keyword arguments
7108 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
7109 Guile Reference Manual}). The value of these arguments is usually
7110 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
7111 by the daemon (@pxref{Derivations}).
7113 The main build system is @code{gnu-build-system}, which implements the
7114 standard build procedure for GNU and many other packages. It
7115 is provided by the @code{(guix build-system gnu)} module.
7117 @defvr {Scheme Variable} gnu-build-system
7118 @code{gnu-build-system} represents the GNU Build System, and variants
7119 thereof (@pxref{Configuration, configuration and makefile conventions,,
7120 standards, GNU Coding Standards}).
7122 @cindex build phases
7123 In a nutshell, packages using it are configured, built, and installed with
7124 the usual @code{./configure && make && make check && make install}
7125 command sequence. In practice, a few additional steps are often needed.
7126 All these steps are split up in separate @dfn{phases},
7127 notably@footnote{Please see the @code{(guix build gnu-build-system)}
7128 modules for more details about the build phases.}:
7132 Unpack the source tarball, and change the current directory to the
7133 extracted source tree. If the source is actually a directory, copy it
7134 to the build tree, and enter that directory.
7136 @item patch-source-shebangs
7137 Patch shebangs encountered in source files so they refer to the right
7138 store file names. For instance, this changes @code{#!/bin/sh} to
7139 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
7142 Run the @file{configure} script with a number of default options, such
7143 as @option{--prefix=/gnu/store/@dots{}}, as well as the options specified
7144 by the @code{#:configure-flags} argument.
7147 Run @code{make} with the list of flags specified with
7148 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
7149 (the default), build with @code{make -j}.
7152 Run @code{make check}, or some other target specified with
7153 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
7154 @code{#:parallel-tests?} argument is true (the default), run @code{make
7158 Run @code{make install} with the flags listed in @code{#:make-flags}.
7160 @item patch-shebangs
7161 Patch shebangs on the installed executable files.
7164 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
7165 is false), copying them to the @code{debug} output when available
7166 (@pxref{Installing Debugging Files}).
7169 @vindex %standard-phases
7170 The build-side module @code{(guix build gnu-build-system)} defines
7171 @code{%standard-phases} as the default list of build phases.
7172 @code{%standard-phases} is a list of symbol/procedure pairs, where the
7173 procedure implements the actual phase.
7175 @xref{Build Phases}, for more info on build phases and ways to customize
7178 In addition, this build system ensures that the ``standard'' environment
7179 for GNU packages is available. This includes tools such as GCC, libc,
7180 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
7181 build-system gnu)} module for a complete list). We call these the
7182 @dfn{implicit inputs} of a package, because package definitions do not
7183 have to mention them.
7186 Other @code{<build-system>} objects are defined to support other
7187 conventions and tools used by free software packages. They inherit most
7188 of @code{gnu-build-system}, and differ mainly in the set of inputs
7189 implicitly added to the build process, and in the list of phases
7190 executed. Some of these build systems are listed below.
7192 @defvr {Scheme Variable} ant-build-system
7193 This variable is exported by @code{(guix build-system ant)}. It
7194 implements the build procedure for Java packages that can be built with
7195 @url{https://ant.apache.org/, Ant build tool}.
7197 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
7198 provided by the @code{icedtea} package to the set of inputs. Different
7199 packages can be specified with the @code{#:ant} and @code{#:jdk}
7200 parameters, respectively.
7202 When the original package does not provide a suitable Ant build file,
7203 the parameter @code{#:jar-name} can be used to generate a minimal Ant
7204 build file @file{build.xml} with tasks to build the specified jar
7205 archive. In this case the parameter @code{#:source-dir} can be used to
7206 specify the source sub-directory, defaulting to ``src''.
7208 The @code{#:main-class} parameter can be used with the minimal ant
7209 buildfile to specify the main class of the resulting jar. This makes the
7210 jar file executable. The @code{#:test-include} parameter can be used to
7211 specify the list of junit tests to run. It defaults to
7212 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
7213 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
7214 because abstract classes cannot be run as tests.
7216 The parameter @code{#:build-target} can be used to specify the Ant task
7217 that should be run during the @code{build} phase. By default the
7218 ``jar'' task will be run.
7222 @defvr {Scheme Variable} android-ndk-build-system
7223 @cindex Android distribution
7224 @cindex Android NDK build system
7225 This variable is exported by @code{(guix build-system android-ndk)}. It
7226 implements a build procedure for Android NDK (native development kit)
7227 packages using a Guix-specific build process.
7229 The build system assumes that packages install their public interface
7230 (header) files to the subdirectory @file{include} of the @code{out} output and
7231 their libraries to the subdirectory @file{lib} the @code{out} output.
7233 It's also assumed that the union of all the dependencies of a package
7234 has no conflicting files.
7236 For the time being, cross-compilation is not supported - so right now
7237 the libraries and header files are assumed to be host tools.
7241 @defvr {Scheme Variable} asdf-build-system/source
7242 @defvrx {Scheme Variable} asdf-build-system/sbcl
7243 @defvrx {Scheme Variable} asdf-build-system/ecl
7245 These variables, exported by @code{(guix build-system asdf)}, implement
7246 build procedures for Common Lisp packages using
7247 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
7248 definition facility for Common Lisp programs and libraries.
7250 The @code{asdf-build-system/source} system installs the packages in
7251 source form, and can be loaded using any common lisp implementation, via
7252 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
7253 systems in the format which a particular implementation understands.
7254 These build systems can also be used to produce executable programs, or
7255 lisp images which contain a set of packages pre-loaded.
7257 The build system uses naming conventions. For binary packages, the
7258 package name should be prefixed with the lisp implementation, such as
7259 @code{sbcl-} for @code{asdf-build-system/sbcl}.
7261 Additionally, the corresponding source package should be labeled using
7262 the same convention as python packages (see @ref{Python Modules}), using
7263 the @code{cl-} prefix.
7265 In order to create executable programs and images, the build-side
7266 procedures @code{build-program} and @code{build-image} can be used.
7267 They should be called in a build phase after the
7268 @code{create-asdf-configuration} phase, so that the system which was
7269 just built can be used within the resulting image. @code{build-program}
7270 requires a list of Common Lisp expressions to be passed as the
7271 @code{#:entry-program} argument.
7273 By default, all the @file{.asd} files present in the sources are read to
7274 find system definitions. The @code{#:asd-files} parameter can be used
7275 to specify the list of @file{.asd} files to read. Furthermore, if the
7276 package defines a system for its tests in a separate file, it will be
7277 loaded before the tests are run if it is specified by the
7278 @code{#:test-asd-file} parameter. If it is not set, the files
7279 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
7280 and @code{test.asd} will be tried if they exist.
7282 If for some reason the package must be named in a different way than the
7283 naming conventions suggest, or if several systems must be compiled, the
7284 @code{#:asd-systems} parameter can be used to specify the list of system
7289 @defvr {Scheme Variable} cargo-build-system
7290 @cindex Rust programming language
7291 @cindex Cargo (Rust build system)
7292 This variable is exported by @code{(guix build-system cargo)}. It
7293 supports builds of packages using Cargo, the build tool of the
7294 @uref{https://www.rust-lang.org, Rust programming language}.
7296 It adds @code{rustc} and @code{cargo} to the set of inputs.
7297 A different Rust package can be specified with the @code{#:rust} parameter.
7299 Regular cargo dependencies should be added to the package definition via the
7300 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
7301 spec can be a package or a source definition. Note that the spec must
7302 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
7303 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
7304 should be added to the package definition via the
7305 @code{#:cargo-development-inputs} parameter.
7307 In its @code{configure} phase, this build system will make any source inputs
7308 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
7309 parameters available to cargo. It will also remove an included
7310 @code{Cargo.lock} file to be recreated by @code{cargo} during the
7311 @code{build} phase. The @code{install} phase installs the binaries
7312 defined by the crate.
7316 @defvr {Scheme Variable} copy-build-system
7317 This variable is exported by @code{(guix build-system copy)}. It
7318 supports builds of simple packages that don't require much compiling,
7319 mostly just moving files around.
7321 It adds much of the @code{gnu-build-system} packages to the set of
7322 inputs. Because of this, the @code{copy-build-system} does not require
7323 all the boilerplate code often needed for the
7324 @code{trivial-build-system}.
7326 To further simplify the file installation process, an
7327 @code{#:install-plan} argument is exposed to let the packager specify
7328 which files go where. The install plan is a list of @code{(@var{source}
7329 @var{target} [@var{filters}])}. @var{filters} are optional.
7332 @item When @var{source} matches a file or directory without trailing slash, install it to @var{target}.
7334 @item If @var{target} has a trailing slash, install @var{source} basename beneath @var{target}.
7335 @item Otherwise install @var{source} as @var{target}.
7338 @item When @var{source} is a directory with a trailing slash, or when @var{filters} are used,
7339 the trailing slash of @var{target} is implied with the same meaning
7342 @item Without @var{filters}, install the full @var{source} @emph{content} to @var{target}.
7343 @item With @var{filters} among @code{#:include}, @code{#:include-regexp}, @code{#:exclude},
7344 @code{#:exclude-regexp}, only select files are installed depending on
7345 the filters. Each filters is specified by a list of strings.
7347 @item With @code{#:include}, install all the files which the path suffix matches
7348 at least one of the elements in the given list.
7349 @item With @code{#:include-regexp}, install all the files which the
7350 subpaths match at least one of the regular expressions in the given
7352 @item The @code{#:exclude} and @code{#:exclude-regexp} filters
7353 are the complement of their inclusion counterpart. Without @code{#:include} flags,
7354 install all files but those matching the exclusion filters.
7355 If both inclusions and exclusions are specified, the exclusions are done
7356 on top of the inclusions.
7359 In all cases, the paths relative to @var{source} are preserved within
7366 @item @code{("foo/bar" "share/my-app/")}: Install @file{bar} to @file{share/my-app/bar}.
7367 @item @code{("foo/bar" "share/my-app/baz")}: Install @file{bar} to @file{share/my-app/baz}.
7368 @item @code{("foo/" "share/my-app")}: Install the content of @file{foo} inside @file{share/my-app},
7369 e.g., install @file{foo/sub/file} to @file{share/my-app/sub/file}.
7370 @item @code{("foo/" "share/my-app" #:include ("sub/file"))}: Install only @file{foo/sub/file} to
7371 @file{share/my-app/sub/file}.
7372 @item @code{("foo/sub" "share/my-app" #:include ("file"))}: Install @file{foo/sub/file} to
7373 @file{share/my-app/file}.
7378 @cindex Clojure (programming language)
7379 @cindex simple Clojure build system
7380 @defvr {Scheme Variable} clojure-build-system
7381 This variable is exported by @code{(guix build-system clojure)}. It implements
7382 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
7383 using plain old @code{compile} in Clojure. Cross-compilation is not supported
7386 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
7387 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
7388 @code{#:zip} parameters, respectively.
7390 A list of source directories, test directories and jar names can be specified
7391 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
7392 parameters, respectively. Compile directory and main class can be specified
7393 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
7394 Other parameters are documented below.
7396 This build system is an extension of @code{ant-build-system}, but with the
7397 following phases changed:
7402 This phase calls @code{compile} in Clojure to compile source files and runs
7403 @command{jar} to create jars from both source files and compiled files
7404 according to the include list and exclude list specified in
7405 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
7406 has priority over the include list. These lists consist of symbols
7407 representing Clojure libraries or the special keyword @code{#:all} representing
7408 all Clojure libraries found under the source directories. The parameter
7409 @code{#:omit-source?} decides if source should be included into the jars.
7412 This phase runs tests according to the include list and exclude list specified
7413 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
7414 meanings are analogous to that of @code{#:aot-include} and
7415 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
7416 stands for all Clojure libraries found under the test directories. The
7417 parameter @code{#:tests?} decides if tests should be run.
7420 This phase installs all jars built previously.
7423 Apart from the above, this build system also contains an additional phase:
7428 This phase installs all top-level files with base name matching
7429 @code{%doc-regex}. A different regex can be specified with the
7430 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
7431 directories specified in @code{#:doc-dirs} are installed as well.
7435 @defvr {Scheme Variable} cmake-build-system
7436 This variable is exported by @code{(guix build-system cmake)}. It
7437 implements the build procedure for packages using the
7438 @url{https://www.cmake.org, CMake build tool}.
7440 It automatically adds the @code{cmake} package to the set of inputs.
7441 Which package is used can be specified with the @code{#:cmake}
7444 The @code{#:configure-flags} parameter is taken as a list of flags
7445 passed to the @command{cmake} command. The @code{#:build-type}
7446 parameter specifies in abstract terms the flags passed to the compiler;
7447 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
7448 debugging information''), which roughly means that code is compiled with
7449 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
7452 @defvr {Scheme Variable} dune-build-system
7453 This variable is exported by @code{(guix build-system dune)}. It
7454 supports builds of packages using @uref{https://dune.build/, Dune}, a build
7455 tool for the OCaml programming language. It is implemented as an extension
7456 of the @code{ocaml-build-system} which is described below. As such, the
7457 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
7460 It automatically adds the @code{dune} package to the set of inputs.
7461 Which package is used can be specified with the @code{#:dune}
7464 There is no @code{configure} phase because dune packages typically don't
7465 need to be configured. The @code{#:build-flags} parameter is taken as a
7466 list of flags passed to the @code{dune} command during the build.
7468 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
7469 command instead of the more recent @code{dune} command while building
7470 a package. Its default value is @code{#f}.
7472 The @code{#:package} parameter can be passed to specify a package name, which
7473 is useful when a package contains multiple packages and you want to build
7474 only one of them. This is equivalent to passing the @code{-p} argument to
7478 @defvr {Scheme Variable} go-build-system
7479 This variable is exported by @code{(guix build-system go)}. It
7480 implements a build procedure for Go packages using the standard
7481 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
7482 Go build mechanisms}.
7484 The user is expected to provide a value for the key @code{#:import-path}
7485 and, in some cases, @code{#:unpack-path}. The
7486 @url{https://golang.org/doc/code.html#ImportPaths, import path}
7487 corresponds to the file system path expected by the package's build
7488 scripts and any referring packages, and provides a unique way to
7489 refer to a Go package. It is typically based on a combination of the
7490 package source code's remote URI and file system hierarchy structure. In
7491 some cases, you will need to unpack the package's source code to a
7492 different directory structure than the one indicated by the import path,
7493 and @code{#:unpack-path} should be used in such cases.
7495 Packages that provide Go libraries should install their source code into
7496 the built output. The key @code{#:install-source?}, which defaults to
7497 @code{#t}, controls whether or not the source code is installed. It can
7498 be set to @code{#f} for packages that only provide executable files.
7501 @defvr {Scheme Variable} glib-or-gtk-build-system
7502 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
7503 is intended for use with packages making use of GLib or GTK+.
7505 This build system adds the following two phases to the ones defined by
7506 @code{gnu-build-system}:
7509 @item glib-or-gtk-wrap
7510 The phase @code{glib-or-gtk-wrap} ensures that programs in
7511 @file{bin/} are able to find GLib ``schemas'' and
7512 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
7513 modules}. This is achieved by wrapping the programs in launch scripts
7514 that appropriately set the @env{XDG_DATA_DIRS} and @env{GTK_PATH}
7515 environment variables.
7517 It is possible to exclude specific package outputs from that wrapping
7518 process by listing their names in the
7519 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
7520 when an output is known not to contain any GLib or GTK+ binaries, and
7521 where wrapping would gratuitously add a dependency of that output on
7524 @item glib-or-gtk-compile-schemas
7525 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
7526 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
7527 GSettings schemas} of GLib are compiled. Compilation is performed by the
7528 @command{glib-compile-schemas} program. It is provided by the package
7529 @code{glib:bin} which is automatically imported by the build system.
7530 The @code{glib} package providing @command{glib-compile-schemas} can be
7531 specified with the @code{#:glib} parameter.
7534 Both phases are executed after the @code{install} phase.
7537 @defvr {Scheme Variable} guile-build-system
7538 This build system is for Guile packages that consist exclusively of Scheme
7539 code and that are so lean that they don't even have a makefile, let alone a
7540 @file{configure} script. It compiles Scheme code using @command{guild
7541 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
7542 installs the @file{.scm} and @file{.go} files in the right place. It also
7543 installs documentation.
7545 This build system supports cross-compilation by using the
7546 @option{--target} option of @samp{guild compile}.
7548 Packages built with @code{guile-build-system} must provide a Guile package in
7549 their @code{native-inputs} field.
7552 @defvr {Scheme Variable} julia-build-system
7553 This variable is exported by @code{(guix build-system julia)}. It
7554 implements the build procedure used by @uref{https://julialang.org/,
7555 julia} packages, which essentially is similar to running @samp{julia -e
7556 'using Pkg; Pkg.add(package)'} in an environment where
7557 @env{JULIA_LOAD_PATH} contains the paths to all Julia package inputs.
7558 Tests are run with @code{Pkg.test}.
7560 Julia packages require the source @code{file-name} to be the real name of the
7561 package, correctly capitalized.
7563 For packages requiring shared library dependencies, you may need to write the
7564 @file{/deps/deps.jl} file manually. It's usually a line of @code{const
7565 variable = /gnu/store/library.so} for each dependency, plus a void function
7566 @code{check_deps() = nothing}.
7568 Some older packages that aren't using @file{Package.toml} yet, will require
7569 this file to be created, too. The function @code{julia-create-package-toml}
7570 helps creating the file. You need to pass the outputs and the source of the
7571 package, it's name (the same as the @code{file-name} parameter), the package
7572 uuid, the package version, and a list of dependencies specified by their name
7576 @defvr {Scheme Variable} maven-build-system
7577 This variable is exported by @code{(guix build-system maven)}. It implements
7578 a build procedure for @uref{https://maven.apache.org, Maven} packages. Maven
7579 is a dependency and lifecycle management tool for Java. A user of Maven
7580 specifies dependencies and plugins in a @file{pom.xml} file that Maven reads.
7581 When Maven does not have one of the dependencies or plugins in its repository,
7582 it will download them and use them to build the package.
7584 The maven build system ensures that maven will not try to download any
7585 dependency by running in offline mode. Maven will fail if a dependency is
7586 missing. Before running Maven, the @file{pom.xml} (and subprojects) are
7587 modified to specify the version of dependencies and plugins that match the
7588 versions available in the guix build environment. Dependencies and plugins
7589 must be installed in the fake maven repository at @file{lib/m2}, and are
7590 symlinked into a proper repository before maven is run. Maven is instructed
7591 to use that repository for the build and installs built artifacts there.
7592 Changed files are copied to the @file{lib/m2} directory of the package output.
7594 You can specify a @file{pom.xml} file with the @code{#:pom-file} argument,
7595 or let the build system use the default @file{pom.xml} file in the sources.
7597 In case you need to specify a dependency's version manually, you can use the
7598 @code{#:local-packages} argument. It takes an association list where the key
7599 is the groupId of the package and its value is an association list where the
7600 key is the artifactId of the package and its value is the version you want to
7601 override in the @file{pom.xml}.
7603 Some packages use dependencies or plugins that are not useful at runtime nor
7604 at build time in Guix. You can alter the @file{pom.xml} file to remove them
7605 using the @code{#:exclude} argument. Its value is an association list where
7606 the key is the groupId of the plugin or dependency you want to remove, and
7607 the value is a list of artifactId you want to remove.
7609 You can override the default @code{jdk} and @code{maven} packages with the
7610 corresponding argument, @code{#:jdk} and @code{#:maven}.
7612 The @code{#:maven-plugins} argument is a list of maven plugins used during
7613 the build, with the same format as the @code{inputs} fields of the package
7614 declaration. Its default value is @code{(default-maven-plugins)} which is
7618 @defvr {Scheme Variable} minify-build-system
7619 This variable is exported by @code{(guix build-system minify)}. It
7620 implements a minification procedure for simple JavaScript packages.
7622 It adds @code{uglify-js} to the set of inputs and uses it to compress
7623 all JavaScript files in the @file{src} directory. A different minifier
7624 package can be specified with the @code{#:uglify-js} parameter, but it
7625 is expected that the package writes the minified code to the standard
7628 When the input JavaScript files are not all located in the @file{src}
7629 directory, the parameter @code{#:javascript-files} can be used to
7630 specify a list of file names to feed to the minifier.
7633 @defvr {Scheme Variable} ocaml-build-system
7634 This variable is exported by @code{(guix build-system ocaml)}. It implements
7635 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
7636 of choosing the correct set of commands to run for each package. OCaml
7637 packages can expect many different commands to be run. This build system will
7640 When the package has a @file{setup.ml} file present at the top-level, it will
7641 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
7642 @code{ocaml setup.ml -install}. The build system will assume that this file
7643 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
7644 care of setting the prefix and enabling tests if they are not disabled. You
7645 can pass configure and build flags with the @code{#:configure-flags} and
7646 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
7647 set of flags used to enable tests. The @code{#:use-make?} key can be used to
7648 bypass this system in the build and install phases.
7650 When the package has a @file{configure} file, it is assumed that it is a
7651 hand-made configure script that requires a different argument format than
7652 in the @code{gnu-build-system}. You can add more flags with the
7653 @code{#:configure-flags} key.
7655 When the package has a @file{Makefile} file (or @code{#:use-make?} is
7656 @code{#t}), it will be used and more flags can be passed to the build and
7657 install phases with the @code{#:make-flags} key.
7659 Finally, some packages do not have these files and use a somewhat standard
7660 location for its build system. In that case, the build system will run
7661 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
7662 providing the path to the required findlib module. Additional flags can
7663 be passed via the @code{#:build-flags} key. Install is taken care of by
7664 @command{opam-installer}. In this case, the @code{opam} package must
7665 be added to the @code{native-inputs} field of the package definition.
7667 Note that most OCaml packages assume they will be installed in the same
7668 directory as OCaml, which is not what we want in guix. In particular, they
7669 will install @file{.so} files in their module's directory, which is usually
7670 fine because it is in the OCaml compiler directory. In guix though, these
7671 libraries cannot be found and we use @env{CAML_LD_LIBRARY_PATH}. This
7672 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
7673 @file{.so} libraries should be installed.
7676 @defvr {Scheme Variable} python-build-system
7677 This variable is exported by @code{(guix build-system python)}. It
7678 implements the more or less standard build procedure used by Python
7679 packages, which consists in running @code{python setup.py build} and
7680 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
7682 For packages that install stand-alone Python programs under @code{bin/},
7683 it takes care of wrapping these programs so that their @env{PYTHONPATH}
7684 environment variable points to all the Python libraries they depend on.
7686 Which Python package is used to perform the build can be specified with
7687 the @code{#:python} parameter. This is a useful way to force a package
7688 to be built for a specific version of the Python interpreter, which
7689 might be necessary if the package is only compatible with a single
7690 interpreter version.
7692 By default guix calls @code{setup.py} under control of
7693 @code{setuptools}, much like @command{pip} does. Some packages are not
7694 compatible with setuptools (and pip), thus you can disable this by
7695 setting the @code{#:use-setuptools?} parameter to @code{#f}.
7698 @defvr {Scheme Variable} perl-build-system
7699 This variable is exported by @code{(guix build-system perl)}. It
7700 implements the standard build procedure for Perl packages, which either
7701 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
7702 followed by @code{Build} and @code{Build install}; or in running
7703 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
7704 @code{make} and @code{make install}, depending on which of
7705 @code{Build.PL} or @code{Makefile.PL} is present in the package
7706 distribution. Preference is given to the former if both @code{Build.PL}
7707 and @code{Makefile.PL} exist in the package distribution. This
7708 preference can be reversed by specifying @code{#t} for the
7709 @code{#:make-maker?} parameter.
7711 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
7712 passes flags specified by the @code{#:make-maker-flags} or
7713 @code{#:module-build-flags} parameter, respectively.
7715 Which Perl package is used can be specified with @code{#:perl}.
7718 @defvr {Scheme Variable} qt-build-system
7719 This variable is exported by @code{(guix build-system qt)}. It
7720 is intended for use with applications using Qt or KDE.
7722 This build system adds the following two phases to the ones defined by
7723 @code{cmake-build-system}:
7727 The phase @code{check-setup} prepares the environment for running
7728 the checks as commonly used by Qt test programs.
7729 For now this only sets some environment variables:
7730 @code{QT_QPA_PLATFORM=offscreen},
7731 @code{DBUS_FATAL_WARNINGS=0} and
7732 @code{CTEST_OUTPUT_ON_FAILURE=1}.
7734 This phase is added before the @code{check} phase.
7735 It's a separate phase to ease adjusting if necessary.
7738 The phase @code{qt-wrap}
7739 searches for Qt5 plugin paths, QML paths and some XDG in the inputs
7740 and output. In case some path is found, all programs in the output's
7741 @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
7742 are wrapped in scripts defining the necessary environment variables.
7744 It is possible to exclude specific package outputs from that wrapping process
7745 by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
7746 This is useful when an output is known not to contain any Qt binaries, and
7747 where wrapping would gratuitously add a dependency of that output on Qt, KDE,
7750 This phase is added after the @code{install} phase.
7754 @defvr {Scheme Variable} r-build-system
7755 This variable is exported by @code{(guix build-system r)}. It
7756 implements the build procedure used by @uref{https://r-project.org, R}
7757 packages, which essentially is little more than running @samp{R CMD
7758 INSTALL --library=/gnu/store/@dots{}} in an environment where
7759 @env{R_LIBS_SITE} contains the paths to all R package inputs. Tests are
7760 run after installation using the R function
7761 @code{tools::testInstalledPackage}.
7764 @defvr {Scheme Variable} rakudo-build-system
7765 This variable is exported by @code{(guix build-system rakudo)}. It
7766 implements the build procedure used by @uref{https://rakudo.org/,
7767 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
7768 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
7769 installs the binaries, library files and the resources, as well as wrap
7770 the files under the @code{bin/} directory. Tests can be skipped by
7771 passing @code{#f} to the @code{tests?} parameter.
7773 Which rakudo package is used can be specified with @code{rakudo}.
7774 Which perl6-tap-harness package used for the tests can be specified with
7775 @code{#:prove6} or removed by passing @code{#f} to the
7776 @code{with-prove6?} parameter.
7777 Which perl6-zef package used for tests and installing can be specified
7778 with @code{#:zef} or removed by passing @code{#f} to the
7779 @code{with-zef?} parameter.
7782 @defvr {Scheme Variable} texlive-build-system
7783 This variable is exported by @code{(guix build-system texlive)}. It is
7784 used to build TeX packages in batch mode with a specified engine. The
7785 build system sets the @env{TEXINPUTS} variable to find all TeX source
7786 files in the inputs.
7788 By default it runs @code{luatex} on all files ending on @code{ins}. A
7789 different engine and format can be specified with the
7790 @code{#:tex-format} argument. Different build targets can be specified
7791 with the @code{#:build-targets} argument, which expects a list of file
7792 names. The build system adds only @code{texlive-bin} and
7793 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
7794 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
7795 and @code{#:texlive-latex-base}, respectively.
7797 The @code{#:tex-directory} parameter tells the build system where to
7798 install the built files under the texmf tree.
7801 @defvr {Scheme Variable} ruby-build-system
7802 This variable is exported by @code{(guix build-system ruby)}. It
7803 implements the RubyGems build procedure used by Ruby packages, which
7804 involves running @code{gem build} followed by @code{gem install}.
7806 The @code{source} field of a package that uses this build system
7807 typically references a gem archive, since this is the format that Ruby
7808 developers use when releasing their software. The build system unpacks
7809 the gem archive, potentially patches the source, runs the test suite,
7810 repackages the gem, and installs it. Additionally, directories and
7811 tarballs may be referenced to allow building unreleased gems from Git or
7812 a traditional source release tarball.
7814 Which Ruby package is used can be specified with the @code{#:ruby}
7815 parameter. A list of additional flags to be passed to the @command{gem}
7816 command can be specified with the @code{#:gem-flags} parameter.
7819 @defvr {Scheme Variable} waf-build-system
7820 This variable is exported by @code{(guix build-system waf)}. It
7821 implements a build procedure around the @code{waf} script. The common
7822 phases---@code{configure}, @code{build}, and @code{install}---are
7823 implemented by passing their names as arguments to the @code{waf}
7826 The @code{waf} script is executed by the Python interpreter. Which
7827 Python package is used to run the script can be specified with the
7828 @code{#:python} parameter.
7831 @defvr {Scheme Variable} scons-build-system
7832 This variable is exported by @code{(guix build-system scons)}. It
7833 implements the build procedure used by the SCons software construction
7834 tool. This build system runs @code{scons} to build the package,
7835 @code{scons test} to run tests, and then @code{scons install} to install
7838 Additional flags to be passed to @code{scons} can be specified with the
7839 @code{#:scons-flags} parameter. The default build and install targets
7840 can be overridden with @code{#:build-targets} and
7841 @code{#:install-targets} respectively. The version of Python used to
7842 run SCons can be specified by selecting the appropriate SCons package
7843 with the @code{#:scons} parameter.
7846 @defvr {Scheme Variable} haskell-build-system
7847 This variable is exported by @code{(guix build-system haskell)}. It
7848 implements the Cabal build procedure used by Haskell packages, which
7849 involves running @code{runhaskell Setup.hs configure
7850 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
7851 Instead of installing the package by running @code{runhaskell Setup.hs
7852 install}, to avoid trying to register libraries in the read-only
7853 compiler store directory, the build system uses @code{runhaskell
7854 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
7855 addition, the build system generates the package documentation by
7856 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
7857 is passed. Optional Haddock parameters can be passed with the help of
7858 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
7859 not found, the build system looks for @code{Setup.lhs} instead.
7861 Which Haskell compiler is used can be specified with the @code{#:haskell}
7862 parameter which defaults to @code{ghc}.
7865 @defvr {Scheme Variable} dub-build-system
7866 This variable is exported by @code{(guix build-system dub)}. It
7867 implements the Dub build procedure used by D packages, which
7868 involves running @code{dub build} and @code{dub run}.
7869 Installation is done by copying the files manually.
7871 Which D compiler is used can be specified with the @code{#:ldc}
7872 parameter which defaults to @code{ldc}.
7875 @defvr {Scheme Variable} emacs-build-system
7876 This variable is exported by @code{(guix build-system emacs)}. It
7877 implements an installation procedure similar to the packaging system
7878 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
7880 It first creates the @code{@code{package}-autoloads.el} file, then it
7881 byte compiles all Emacs Lisp files. Differently from the Emacs
7882 packaging system, the Info documentation files are moved to the standard
7883 documentation directory and the @file{dir} file is deleted. The Elisp
7884 package files are installed directly under @file{share/emacs/site-lisp}.
7887 @defvr {Scheme Variable} font-build-system
7888 This variable is exported by @code{(guix build-system font)}. It
7889 implements an installation procedure for font packages where upstream
7890 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
7891 need to be copied into place. It copies font files to standard
7892 locations in the output directory.
7895 @defvr {Scheme Variable} meson-build-system
7896 This variable is exported by @code{(guix build-system meson)}. It
7897 implements the build procedure for packages that use
7898 @url{https://mesonbuild.com, Meson} as their build system.
7900 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
7901 of inputs, and they can be changed with the parameters @code{#:meson}
7902 and @code{#:ninja} if needed. The default Meson is
7903 @code{meson-for-build}, which is special because it doesn't clear the
7904 @code{RUNPATH} of binaries and libraries when they are installed.
7906 This build system is an extension of @code{gnu-build-system}, but with the
7907 following phases changed to some specific for Meson:
7912 The phase runs @code{meson} with the flags specified in
7913 @code{#:configure-flags}. The flag @option{--buildtype} is always set to
7914 @code{debugoptimized} unless something else is specified in
7915 @code{#:build-type}.
7918 The phase runs @code{ninja} to build the package in parallel by default, but
7919 this can be changed with @code{#:parallel-build?}.
7922 The phase runs @code{ninja} with the target specified in @code{#:test-target},
7923 which is @code{"test"} by default.
7926 The phase runs @code{ninja install} and can not be changed.
7929 Apart from that, the build system also adds the following phases:
7934 This phase ensures that all binaries can find the libraries they need.
7935 It searches for required libraries in subdirectories of the package being
7936 built, and adds those to @code{RUNPATH} where needed. It also removes
7937 references to libraries left over from the build phase by
7938 @code{meson-for-build}, such as test dependencies, that aren't actually
7939 required for the program to run.
7941 @item glib-or-gtk-wrap
7942 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
7943 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
7945 @item glib-or-gtk-compile-schemas
7946 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
7947 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
7951 @defvr {Scheme Variable} linux-module-build-system
7952 @code{linux-module-build-system} allows building Linux kernel modules.
7954 @cindex build phases
7955 This build system is an extension of @code{gnu-build-system}, but with the
7956 following phases changed:
7961 This phase configures the environment so that the Linux kernel's Makefile
7962 can be used to build the external kernel module.
7965 This phase uses the Linux kernel's Makefile in order to build the external
7969 This phase uses the Linux kernel's Makefile in order to install the external
7973 It is possible and useful to specify the Linux kernel to use for building
7974 the module (in the @code{arguments} form of a package using the
7975 @code{linux-module-build-system}, use the key @code{#:linux} to specify it).
7978 @defvr {Scheme Variable} node-build-system
7979 This variable is exported by @code{(guix build-system node)}. It
7980 implements the build procedure used by @uref{https://nodejs.org,
7981 Node.js}, which implements an approximation of the @code{npm install}
7982 command, followed by an @code{npm test} command.
7984 Which Node.js package is used to interpret the @code{npm} commands can
7985 be specified with the @code{#:node} parameter which defaults to
7989 Lastly, for packages that do not need anything as sophisticated, a
7990 ``trivial'' build system is provided. It is trivial in the sense that
7991 it provides basically no support: it does not pull any implicit inputs,
7992 and does not have a notion of build phases.
7994 @defvr {Scheme Variable} trivial-build-system
7995 This variable is exported by @code{(guix build-system trivial)}.
7997 This build system requires a @code{#:builder} argument. This argument
7998 must be a Scheme expression that builds the package output(s)---as
7999 with @code{build-expression->derivation} (@pxref{Derivations,
8000 @code{build-expression->derivation}}).
8004 @section Build Phases
8006 @cindex build phases, for packages
8007 Almost all package build systems implement a notion @dfn{build phases}:
8008 a sequence of actions that the build system executes, when you build the
8009 package, leading to the installed byproducts in the store. A notable
8010 exception is the ``bare-bones'' @code{trivial-build-system}
8011 (@pxref{Build Systems}).
8013 As discussed in the previous section, those build systems provide a
8014 standard list of phases. For @code{gnu-build-system}, the standard
8015 phases include an @code{unpack} phase to unpack the source code tarball,
8016 a @command{configure} phase to run @code{./configure}, a @code{build}
8017 phase to run @command{make}, and (among others) an @code{install} phase
8018 to run @command{make install}; @pxref{Build Systems}, for a more
8019 detailed view of these phases. Likewise, @code{cmake-build-system}
8020 inherits these phases, but its @code{configure} phase runs
8021 @command{cmake} instead of @command{./configure}. Other build systems,
8022 such as @code{python-build-system}, have a wholly different list of
8023 standard phases. All this code runs on the @dfn{build side}: it is
8024 evaluated when you actually build the package, in a dedicated build
8025 process spawned by the build daemon (@pxref{Invoking guix-daemon}).
8027 Build phases are represented as association lists or ``alists''
8028 (@pxref{Association Lists,,, guile, GNU Guile Reference Manual}) where
8029 each key is a symbol for the name of the phase and the associated value
8030 is a procedure that accepts an arbitrary number of arguments. By
8031 convention, those procedures receive information about the build in the
8032 form of @dfn{keyword parameters}, which they can use or ignore.
8034 For example, here is how @code{(guix build gnu-build-system)} defines
8035 @code{%standard-phases}, the variable holding its alist of build
8036 phases@footnote{We present a simplified view of those build phases, but
8037 do take a look at @code{(guix build gnu-build-system)} to see all the
8041 ;; The build phases of 'gnu-build-system'.
8043 (define* (unpack #:key source #:allow-other-keys)
8044 ;; Extract the source tarball.
8045 (invoke "tar" "xvf" source))
8047 (define* (configure #:key outputs #:allow-other-keys)
8048 ;; Run the 'configure' script. Install to output "out".
8049 (let ((out (assoc-ref outputs "out")))
8050 (invoke "./configure"
8051 (string-append "--prefix=" out))))
8053 (define* (build #:allow-other-keys)
8057 (define* (check #:key (test-target "check") (tests? #true)
8059 ;; Run the test suite.
8061 (invoke "make" test-target)
8062 (display "test suite not run\n")))
8064 (define* (install #:allow-other-keys)
8065 ;; Install files to the prefix 'configure' specified.
8066 (invoke "make" "install"))
8068 (define %standard-phases
8069 ;; The list of standard phases (quite a few are omitted
8070 ;; for brevity). Each element is a symbol/procedure pair.
8071 (list (cons 'unpack unpack)
8072 (cons 'configure configure)
8075 (cons 'install install)))
8078 This shows how @code{%standard-phases} is defined as a list of
8079 symbol/procedure pairs (@pxref{Pairs,,, guile, GNU Guile Reference
8080 Manual}). The first pair associates the @code{unpack} procedure with
8081 the @code{unpack} symbol---a name; the second pair defines the
8082 @code{configure} phase similarly, and so on. When building a package
8083 that uses @code{gnu-build-system} with its default list of phases, those
8084 phases are executed sequentially. You can see the name of each phase
8085 started and completed in the build log of packages that you build.
8087 Let's now look at the procedures themselves. Each one is defined with
8088 @code{define*}: @code{#:key} lists keyword parameters the procedure
8089 accepts, possibly with a default value, and @code{#:allow-other-keys}
8090 specifies that other keyword parameters are ignored (@pxref{Optional
8091 Arguments,,, guile, GNU Guile Reference Manual}).
8093 The @code{unpack} procedure honors the @code{source} parameter, which
8094 the build system uses to pass the file name of the source tarball (or
8095 version control checkout), and it ignores other parameters. The
8096 @code{configure} phase only cares about the @code{outputs} parameter, an
8097 alist mapping package output names to their store file name
8098 (@pxref{Packages with Multiple Outputs}). It extracts the file name of
8099 for @code{out}, the default output, and passes it to
8100 @command{./configure} as the installation prefix, meaning that
8101 @command{make install} will eventually copy all the files in that
8102 directory (@pxref{Configuration, configuration and makefile
8103 conventions,, standards, GNU Coding Standards}). @code{build} and
8104 @code{install} ignore all their arguments. @code{check} honors the
8105 @code{test-target} argument, which specifies the name of the Makefile
8106 target to run tests; it prints a message and skips tests when
8107 @code{tests?} is false.
8109 @cindex build phases, customizing
8110 The list of phases used for a particular package can be changed with the
8111 @code{#:phases} parameter of the build system. Changing the set of
8112 build phases boils down to building a new alist of phases based on the
8113 @code{%standard-phases} alist described above. This can be done with
8114 standard alist procedures such as @code{alist-delete} (@pxref{SRFI-1
8115 Association Lists,,, guile, GNU Guile Reference Manual}); however, it is
8116 more convenient to do so with @code{modify-phases} (@pxref{Build
8117 Utilities, @code{modify-phases}}).
8119 Here is an example of a package definition that removes the
8120 @code{configure} phase of @code{%standard-phases} and inserts a new
8121 phase before the @code{build} phase, called
8122 @code{set-prefix-in-makefile}:
8125 (define-public example
8128 ;; other fields omitted
8129 (build-system gnu-build-system)
8131 '(#:phases (modify-phases %standard-phases
8133 (add-before 'build 'set-prefix-in-makefile
8134 (lambda* (#:key outputs #:allow-other-keys)
8135 ;; Modify the makefile so that its
8136 ;; 'PREFIX' variable points to "out".
8137 (let ((out (assoc-ref outputs "out")))
8138 (substitute* "Makefile"
8140 (string-append "PREFIX = "
8145 The new phase that is inserted is written as an anonymous procedure,
8146 introduced with @code{lambda*}; it honors the @code{outputs} parameter
8147 we have seen before. @xref{Build Utilities}, for more about the helpers
8148 used by this phase, and for more examples of @code{modify-phases}.
8150 @cindex code staging
8151 @cindex staging, of code
8152 Keep in mind that build phases are code evaluated at the time the
8153 package is actually built. This explains why the whole
8154 @code{modify-phases} expression above is quoted (it comes after the
8155 @code{'} or apostrophe): it is @dfn{staged} for later execution.
8156 @xref{G-Expressions}, for an explanation of code staging and the
8157 @dfn{code strata} involved.
8159 @node Build Utilities
8160 @section Build Utilities
8162 As soon as you start writing non-trivial package definitions
8163 (@pxref{Defining Packages}) or other build actions
8164 (@pxref{G-Expressions}), you will likely start looking for helpers for
8165 ``shell-like'' actions---creating directories, copying and deleting
8166 files recursively, manipulating build phases, and so on. The
8167 @code{(guix build utils)} module provides such utility procedures.
8169 Most build systems load @code{(guix build utils)} (@pxref{Build
8170 Systems}). Thus, when writing custom build phases for your package
8171 definitions, you can usually assume those procedures are in scope.
8173 When writing G-expressions, you can import @code{(guix build utils)} on
8174 the ``build side'' using @code{with-imported-modules} and then put it in
8175 scope with the @code{use-modules} form (@pxref{Using Guile Modules,,,
8176 guile, GNU Guile Reference Manual}):
8179 (with-imported-modules '((guix build utils)) ;import it
8180 (computed-file "empty-tree"
8183 (use-modules (guix build utils))
8185 ;; Happily use its 'mkdir-p' procedure.
8186 (mkdir-p (string-append #$output "/a/b/c")))))
8189 The remainder of this section is the reference for most of the utility
8190 procedures provided by @code{(guix build utils)}.
8192 @c TODO Document what's missing.
8194 @subsection Dealing with Store File Names
8196 This section documents procedures that deal with store file names.
8198 @deffn {Scheme Procedure} %store-directory
8199 Return the directory name of the store.
8202 @deffn {Scheme Procedure} store-file-name? @var{file}
8203 Return true if @var{file} is in the store.
8206 @deffn {Scheme Procedure} strip-store-file-name @var{file}
8207 Strip the @file{/gnu/store} and hash from @var{file}, a store file name.
8208 The result is typically a @code{"@var{package}-@var{version}"} string.
8211 @deffn {Scheme Procedure} package-name->name+version @var{name}
8212 Given @var{name}, a package name like @code{"foo-0.9.1b"}, return two
8213 values: @code{"foo"} and @code{"0.9.1b"}. When the version part is
8214 unavailable, @var{name} and @code{#f} are returned. The first hyphen
8215 followed by a digit is considered to introduce the version part.
8218 @subsection File Types
8220 The procedures below deal with files and file types.
8222 @deffn {Scheme Procedure} directory-exists? @var{dir}
8223 Return @code{#t} if @var{dir} exists and is a directory.
8226 @deffn {Scheme Procedure} executable-file? @var{file}
8227 Return @code{#t} if @var{file} exists and is executable.
8230 @deffn {Scheme Procedure} symbolic-link? @var{file}
8231 Return @code{#t} if @var{file} is a symbolic link (aka. a ``symlink'').
8234 @deffn {Scheme Procedure} elf-file? @var{file}
8235 @deffnx {Scheme Procedure} ar-file? @var{file}
8236 @deffnx {Scheme Procedure} gzip-file? @var{file}
8237 Return @code{#t} if @var{file} is, respectively, an ELF file, an
8238 @code{ar} archive (such as a @file{.a} static library), or a gzip file.
8241 @deffn {Scheme Procedure} reset-gzip-timestamp @var{file} [#:keep-mtime? #t]
8242 If @var{file} is a gzip file, reset its embedded timestamp (as with
8243 @command{gzip --no-name}) and return true. Otherwise return @code{#f}.
8244 When @var{keep-mtime?} is true, preserve @var{file}'s modification time.
8247 @subsection File Manipulation
8249 The following procedures and macros help create, modify, and delete
8250 files. They provide functionality comparable to common shell utilities
8251 such as @command{mkdir -p}, @command{cp -r}, @command{rm -r}, and
8252 @command{sed}. They complement Guile's extensive, but low-level, file
8253 system interface (@pxref{POSIX,,, guile, GNU Guile Reference Manual}).
8255 @deffn {Scheme Syntax} with-directory-excursion @var{directory} @var{body}@dots{}
8256 Run @var{body} with @var{directory} as the process's current directory.
8258 Essentially, this macro changes the current directory to @var{directory}
8259 before evaluating @var{body}, using @code{chdir} (@pxref{Processes,,,
8260 guile, GNU Guile Reference Manual}). It changes back to the initial
8261 directory when the dynamic extent of @var{body} is left, be it @i{via}
8262 normal procedure return or @i{via} a non-local exit such as an
8266 @deffn {Scheme Procedure} mkdir-p @var{dir}
8267 Create directory @var{dir} and all its ancestors.
8270 @deffn {Scheme Procedure} install-file @var{file} @var{directory}
8271 Create @var{directory} if it does not exist and copy @var{file} in there
8272 under the same name.
8275 @deffn {Scheme Procedure} make-file-writable @var{file}
8276 Make @var{file} writable for its owner.
8279 @deffn {Scheme Procedure} copy-recursively @var{source} @var{destination} @
8280 [#:log (current-output-port)] [#:follow-symlinks? #f] [#:keep-mtime? #f]
8281 Copy @var{source} directory to @var{destination}. Follow symlinks if
8282 @var{follow-symlinks?} is true; otherwise, just preserve them. When
8283 @var{keep-mtime?} is true, keep the modification time of the files in
8284 @var{source} on those of @var{destination}. Write verbose output to the
8288 @deffn {Scheme Procedure} delete-file-recursively @var{dir} @
8289 [#:follow-mounts? #f]
8290 Delete @var{dir} recursively, like @command{rm -rf}, without following
8291 symlinks. Don't follow mount points either, unless @var{follow-mounts?}
8292 is true. Report but ignore errors.
8295 @deffn {Scheme Syntax} substitute* @var{file} @
8296 ((@var{regexp} @var{match-var}@dots{}) @var{body}@dots{}) @dots{}
8297 Substitute @var{regexp} in @var{file} by the string returned by
8298 @var{body}. @var{body} is evaluated with each @var{match-var} bound to
8299 the corresponding positional regexp sub-expression. For example:
8305 (("foo([a-z]+)bar(.*)$" all letters end)
8306 (string-append "baz" letter end)))
8309 Here, anytime a line of @var{file} contains @code{hello}, it is replaced
8310 by @code{good morning}. Anytime a line of @var{file} matches the second
8311 regexp, @code{all} is bound to the complete match, @code{letters} is bound
8312 to the first sub-expression, and @code{end} is bound to the last one.
8314 When one of the @var{match-var} is @code{_}, no variable is bound to the
8315 corresponding match substring.
8317 Alternatively, @var{file} may be a list of file names, in which case
8318 they are all subject to the substitutions.
8320 Be careful about using @code{$} to match the end of a line; by itself it
8321 won't match the terminating newline of a line.
8324 @subsection File Search
8326 @cindex file, searching
8327 This section documents procedures to search and filter files.
8329 @deffn {Scheme Procedure} file-name-predicate @var{regexp}
8330 Return a predicate that returns true when passed a file name whose base
8331 name matches @var{regexp}.
8334 @deffn {Scheme Procedure} find-files @var{dir} [@var{pred}] @
8335 [#:stat lstat] [#:directories? #f] [#:fail-on-error? #f]
8336 Return the lexicographically sorted list of files under @var{dir} for
8337 which @var{pred} returns true. @var{pred} is passed two arguments: the
8338 absolute file name, and its stat buffer; the default predicate always
8339 returns true. @var{pred} can also be a regular expression, in which
8340 case it is equivalent to @code{(file-name-predicate @var{pred})}.
8341 @var{stat} is used to obtain file information; using @code{lstat} means
8342 that symlinks are not followed. If @var{directories?} is true, then
8343 directories will also be included. If @var{fail-on-error?} is true,
8344 raise an exception upon error.
8347 Here are a few examples where we assume that the current directory is
8348 the root of the Guix source tree:
8351 ;; List all the regular files in the current directory.
8353 @result{} ("./.dir-locals.el" "./.gitignore" @dots{})
8355 ;; List all the .scm files under gnu/services.
8356 (find-files "gnu/services" "\\.scm$")
8357 @result{} ("gnu/services/admin.scm" "gnu/services/audio.scm" @dots{})
8359 ;; List ar files in the current directory.
8360 (find-files "." (lambda (file stat) (ar-file? file)))
8361 @result{} ("./libformat.a" "./libstore.a" @dots{})
8364 @deffn {Scheme Procedure} which @var{program}
8365 Return the complete file name for @var{program} as found in
8366 @code{$PATH}, or @code{#f} if @var{program} could not be found.
8369 @subsection Build Phases
8371 @cindex build phases
8372 The @code{(guix build utils)} also contains tools to manipulate build
8373 phases as used by build systems (@pxref{Build Systems}). Build phases
8374 are represented as association lists or ``alists'' (@pxref{Association
8375 Lists,,, guile, GNU Guile Reference Manual}) where each key is a symbol
8376 naming the phase and the associated value is a procedure (@pxref{Build
8379 Guile core and the @code{(srfi srfi-1)} module both provide tools to
8380 manipulate alists. The @code{(guix build utils)} module complements
8381 those with tools written with build phases in mind.
8383 @cindex build phases, modifying
8384 @deffn {Scheme Syntax} modify-phases @var{phases} @var{clause}@dots{}
8385 Modify @var{phases} sequentially as per each @var{clause}, which may
8386 have one of the following forms:
8389 (delete @var{old-phase-name})
8390 (replace @var{old-phase-name} @var{new-phase})
8391 (add-before @var{old-phase-name} @var{new-phase-name} @var{new-phase})
8392 (add-after @var{old-phase-name} @var{new-phase-name} @var{new-phase})
8395 Where every @var{phase-name} above is an expression evaluating to a
8396 symbol, and @var{new-phase} an expression evaluating to a procedure.
8399 The example below is taken from the definition of the @code{grep}
8400 package. It adds a phase to run after the @code{install} phase, called
8401 @code{fix-egrep-and-fgrep}. That phase is a procedure (@code{lambda*}
8402 is for anonymous procedures) that takes a @code{#:outputs} keyword
8403 argument and ignores extra keyword arguments (@pxref{Optional
8404 Arguments,,, guile, GNU Guile Reference Manual}, for more on
8405 @code{lambda*} and optional and keyword arguments.) The phase uses
8406 @code{substitute*} to modify the installed @file{egrep} and @file{fgrep}
8407 scripts so that they refer to @code{grep} by its absolute file name:
8410 (modify-phases %standard-phases
8411 (add-after 'install 'fix-egrep-and-fgrep
8412 ;; Patch 'egrep' and 'fgrep' to execute 'grep' via its
8413 ;; absolute file name instead of searching for it in $PATH.
8414 (lambda* (#:key outputs #:allow-other-keys)
8415 (let* ((out (assoc-ref outputs "out"))
8416 (bin (string-append out "/bin")))
8417 (substitute* (list (string-append bin "/egrep")
8418 (string-append bin "/fgrep"))
8420 (string-append "exec " bin "/grep")))
8424 In the example below, phases are modified in two ways: the standard
8425 @code{configure} phase is deleted, presumably because the package does
8426 not have a @file{configure} script or anything similar, and the default
8427 @code{install} phase is replaced by one that manually copies the
8428 executable files to be installed:
8431 (modify-phases %standard-phases
8432 (delete 'configure) ;no 'configure' script
8434 (lambda* (#:key outputs #:allow-other-keys)
8435 ;; The package's Makefile doesn't provide an "install"
8436 ;; rule so do it by ourselves.
8437 (let ((bin (string-append (assoc-ref outputs "out")
8439 (install-file "footswitch" bin)
8440 (install-file "scythe" bin)
8444 @c TODO: Add more examples.
8453 Conceptually, the @dfn{store} is the place where derivations that have
8454 been built successfully are stored---by default, @file{/gnu/store}.
8455 Sub-directories in the store are referred to as @dfn{store items} or
8456 sometimes @dfn{store paths}. The store has an associated database that
8457 contains information such as the store paths referred to by each store
8458 path, and the list of @emph{valid} store items---results of successful
8459 builds. This database resides in @file{@var{localstatedir}/guix/db},
8460 where @var{localstatedir} is the state directory specified @i{via}
8461 @option{--localstatedir} at configure time, usually @file{/var}.
8463 The store is @emph{always} accessed by the daemon on behalf of its clients
8464 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
8465 connect to the daemon over a Unix-domain socket, send requests to it,
8466 and read the result---these are remote procedure calls, or RPCs.
8469 Users must @emph{never} modify files under @file{/gnu/store} directly.
8470 This would lead to inconsistencies and break the immutability
8471 assumptions of Guix's functional model (@pxref{Introduction}).
8473 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
8474 how to check the integrity of the store and attempt recovery from
8475 accidental modifications.
8478 The @code{(guix store)} module provides procedures to connect to the
8479 daemon, and to perform RPCs. These are described below. By default,
8480 @code{open-connection}, and thus all the @command{guix} commands,
8481 connect to the local daemon or to the URI specified by the
8482 @env{GUIX_DAEMON_SOCKET} environment variable.
8484 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
8485 When set, the value of this variable should be a file name or a URI
8486 designating the daemon endpoint. When it is a file name, it denotes a
8487 Unix-domain socket to connect to. In addition to file names, the
8488 supported URI schemes are:
8493 These are for Unix-domain sockets.
8494 @code{file:///var/guix/daemon-socket/socket} is equivalent to
8495 @file{/var/guix/daemon-socket/socket}.
8498 @cindex daemon, remote access
8499 @cindex remote access to the daemon
8500 @cindex daemon, cluster setup
8501 @cindex clusters, daemon setup
8502 These URIs denote connections over TCP/IP, without encryption nor
8503 authentication of the remote host. The URI must specify the host name
8504 and optionally a port number (by default port 44146 is used):
8507 guix://master.guix.example.org:1234
8510 This setup is suitable on local networks, such as clusters, where only
8511 trusted nodes may connect to the build daemon at
8512 @code{master.guix.example.org}.
8514 The @option{--listen} option of @command{guix-daemon} can be used to
8515 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
8516 @option{--listen}}).
8519 @cindex SSH access to build daemons
8520 These URIs allow you to connect to a remote daemon over SSH. This
8521 feature requires Guile-SSH (@pxref{Requirements}) and a working
8522 @command{guile} binary in @env{PATH} on the destination machine. It
8523 supports public key and GSSAPI authentication. A typical URL might look
8527 ssh://charlie@@guix.example.org:22
8530 As for @command{guix copy}, the usual OpenSSH client configuration files
8531 are honored (@pxref{Invoking guix copy}).
8534 Additional URI schemes may be supported in the future.
8536 @c XXX: Remove this note when the protocol incurs fewer round trips
8537 @c and when (guix derivations) no longer relies on file system access.
8539 The ability to connect to remote build daemons is considered
8540 experimental as of @value{VERSION}. Please get in touch with us to
8541 share any problems or suggestions you may have (@pxref{Contributing}).
8545 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
8546 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
8547 @var{reserve-space?} is true, instruct it to reserve a little bit of
8548 extra space on the file system so that the garbage collector can still
8549 operate should the disk become full. Return a server object.
8551 @var{file} defaults to @code{%default-socket-path}, which is the normal
8552 location given the options that were passed to @command{configure}.
8555 @deffn {Scheme Procedure} close-connection @var{server}
8556 Close the connection to @var{server}.
8559 @defvr {Scheme Variable} current-build-output-port
8560 This variable is bound to a SRFI-39 parameter, which refers to the port
8561 where build and error logs sent by the daemon should be written.
8564 Procedures that make RPCs all take a server object as their first
8567 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
8568 @cindex invalid store items
8569 Return @code{#t} when @var{path} designates a valid store item and
8570 @code{#f} otherwise (an invalid item may exist on disk but still be
8571 invalid, for instance because it is the result of an aborted or failed
8574 A @code{&store-protocol-error} condition is raised if @var{path} is not
8575 prefixed by the store directory (@file{/gnu/store}).
8578 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
8579 Add @var{text} under file @var{name} in the store, and return its store
8580 path. @var{references} is the list of store paths referred to by the
8581 resulting store path.
8584 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
8586 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
8587 file names, or derivation/output pairs, using the specified
8588 @var{mode}---@code{(build-mode normal)} by default.
8591 Note that the @code{(guix monads)} module provides a monad as well as
8592 monadic versions of the above procedures, with the goal of making it
8593 more convenient to work with code that accesses the store (@pxref{The
8597 @i{This section is currently incomplete.}
8600 @section Derivations
8603 Low-level build actions and the environment in which they are performed
8604 are represented by @dfn{derivations}. A derivation contains the
8605 following pieces of information:
8609 The outputs of the derivation---derivations produce at least one file or
8610 directory in the store, but may produce more.
8613 @cindex build-time dependencies
8614 @cindex dependencies, build-time
8615 The inputs of the derivations---i.e., its build-time dependencies---which may
8616 be other derivations or plain files in the store (patches, build scripts,
8620 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
8623 The file name of a build script in the store, along with the arguments
8627 A list of environment variables to be defined.
8631 @cindex derivation path
8632 Derivations allow clients of the daemon to communicate build actions to
8633 the store. They exist in two forms: as an in-memory representation,
8634 both on the client- and daemon-side, and as files in the store whose
8635 name end in @file{.drv}---these files are referred to as @dfn{derivation
8636 paths}. Derivations paths can be passed to the @code{build-derivations}
8637 procedure to perform the build actions they prescribe (@pxref{The
8640 @cindex fixed-output derivations
8641 Operations such as file downloads and version-control checkouts for
8642 which the expected content hash is known in advance are modeled as
8643 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
8644 of a fixed-output derivation are independent of its inputs---e.g., a
8645 source code download produces the same result regardless of the download
8646 method and tools being used.
8649 @cindex run-time dependencies
8650 @cindex dependencies, run-time
8651 The outputs of derivations---i.e., the build results---have a set of
8652 @dfn{references}, as reported by the @code{references} RPC or the
8653 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
8654 are the set of run-time dependencies of the build results. References are a
8655 subset of the inputs of the derivation; this subset is automatically computed
8656 by the build daemon by scanning all the files in the outputs.
8658 The @code{(guix derivations)} module provides a representation of
8659 derivations as Scheme objects, along with procedures to create and
8660 otherwise manipulate derivations. The lowest-level primitive to create
8661 a derivation is the @code{derivation} procedure:
8663 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
8664 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
8665 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
8666 [#:system (%current-system)] [#:references-graphs #f] @
8667 [#:allowed-references #f] [#:disallowed-references #f] @
8668 [#:leaked-env-vars #f] [#:local-build? #f] @
8669 [#:substitutable? #t] [#:properties '()]
8670 Build a derivation with the given arguments, and return the resulting
8671 @code{<derivation>} object.
8673 When @var{hash} and @var{hash-algo} are given, a
8674 @dfn{fixed-output derivation} is created---i.e., one whose result is
8675 known in advance, such as a file download. If, in addition,
8676 @var{recursive?} is true, then that fixed output may be an executable
8677 file or a directory and @var{hash} must be the hash of an archive
8678 containing this output.
8680 When @var{references-graphs} is true, it must be a list of file
8681 name/store path pairs. In that case, the reference graph of each store
8682 path is exported in the build environment in the corresponding file, in
8683 a simple text format.
8685 When @var{allowed-references} is true, it must be a list of store items
8686 or outputs that the derivation's output may refer to. Likewise,
8687 @var{disallowed-references}, if true, must be a list of things the
8688 outputs may @emph{not} refer to.
8690 When @var{leaked-env-vars} is true, it must be a list of strings
8691 denoting environment variables that are allowed to ``leak'' from the
8692 daemon's environment to the build environment. This is only applicable
8693 to fixed-output derivations---i.e., when @var{hash} is true. The main
8694 use is to allow variables such as @code{http_proxy} to be passed to
8695 derivations that download files.
8697 When @var{local-build?} is true, declare that the derivation is not a
8698 good candidate for offloading and should rather be built locally
8699 (@pxref{Daemon Offload Setup}). This is the case for small derivations
8700 where the costs of data transfers would outweigh the benefits.
8702 When @var{substitutable?} is false, declare that substitutes of the
8703 derivation's output should not be used (@pxref{Substitutes}). This is
8704 useful, for instance, when building packages that capture details of the
8705 host CPU instruction set.
8707 @var{properties} must be an association list describing ``properties'' of the
8708 derivation. It is kept as-is, uninterpreted, in the derivation.
8712 Here's an example with a shell script as its builder, assuming
8713 @var{store} is an open connection to the daemon, and @var{bash} points
8714 to a Bash executable in the store:
8717 (use-modules (guix utils)
8721 (let ((builder ; add the Bash script to the store
8722 (add-text-to-store store "my-builder.sh"
8723 "echo hello world > $out\n" '())))
8724 (derivation store "foo"
8725 bash `("-e" ,builder)
8726 #:inputs `((,bash) (,builder))
8727 #:env-vars '(("HOME" . "/homeless"))))
8728 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
8731 As can be guessed, this primitive is cumbersome to use directly. A
8732 better approach is to write build scripts in Scheme, of course! The
8733 best course of action for that is to write the build code as a
8734 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
8735 information, @pxref{G-Expressions}.
8737 Once upon a time, @code{gexp->derivation} did not exist and constructing
8738 derivations with build code written in Scheme was achieved with
8739 @code{build-expression->derivation}, documented below. This procedure
8740 is now deprecated in favor of the much nicer @code{gexp->derivation}.
8742 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
8743 @var{name} @var{exp} @
8744 [#:system (%current-system)] [#:inputs '()] @
8745 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
8746 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
8747 [#:references-graphs #f] [#:allowed-references #f] @
8748 [#:disallowed-references #f] @
8749 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
8750 Return a derivation that executes Scheme expression @var{exp} as a
8751 builder for derivation @var{name}. @var{inputs} must be a list of
8752 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
8753 @code{"out"} is assumed. @var{modules} is a list of names of Guile
8754 modules from the current search path to be copied in the store,
8755 compiled, and made available in the load path during the execution of
8756 @var{exp}---e.g., @code{((guix build utils) (guix build
8757 gnu-build-system))}.
8759 @var{exp} is evaluated in an environment where @code{%outputs} is bound
8760 to a list of output/path pairs, and where @code{%build-inputs} is bound
8761 to a list of string/output-path pairs made from @var{inputs}.
8762 Optionally, @var{env-vars} is a list of string pairs specifying the name
8763 and value of environment variables visible to the builder. The builder
8764 terminates by passing the result of @var{exp} to @code{exit}; thus, when
8765 @var{exp} returns @code{#f}, the build is considered to have failed.
8767 @var{exp} is built using @var{guile-for-build} (a derivation). When
8768 @var{guile-for-build} is omitted or is @code{#f}, the value of the
8769 @code{%guile-for-build} fluid is used instead.
8771 See the @code{derivation} procedure for the meaning of
8772 @var{references-graphs}, @var{allowed-references},
8773 @var{disallowed-references}, @var{local-build?}, and
8774 @var{substitutable?}.
8778 Here's an example of a single-output derivation that creates a directory
8779 containing one file:
8782 (let ((builder '(let ((out (assoc-ref %outputs "out")))
8783 (mkdir out) ; create /gnu/store/@dots{}-goo
8784 (call-with-output-file (string-append out "/test")
8786 (display '(hello guix) p))))))
8787 (build-expression->derivation store "goo" builder))
8789 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
8793 @node The Store Monad
8794 @section The Store Monad
8798 The procedures that operate on the store described in the previous
8799 sections all take an open connection to the build daemon as their first
8800 argument. Although the underlying model is functional, they either have
8801 side effects or depend on the current state of the store.
8803 The former is inconvenient: the connection to the build daemon has to be
8804 carried around in all those functions, making it impossible to compose
8805 functions that do not take that parameter with functions that do. The
8806 latter can be problematic: since store operations have side effects
8807 and/or depend on external state, they have to be properly sequenced.
8809 @cindex monadic values
8810 @cindex monadic functions
8811 This is where the @code{(guix monads)} module comes in. This module
8812 provides a framework for working with @dfn{monads}, and a particularly
8813 useful monad for our uses, the @dfn{store monad}. Monads are a
8814 construct that allows two things: associating ``context'' with values
8815 (in our case, the context is the store), and building sequences of
8816 computations (here computations include accesses to the store). Values
8817 in a monad---values that carry this additional context---are called
8818 @dfn{monadic values}; procedures that return such values are called
8819 @dfn{monadic procedures}.
8821 Consider this ``normal'' procedure:
8824 (define (sh-symlink store)
8825 ;; Return a derivation that symlinks the 'bash' executable.
8826 (let* ((drv (package-derivation store bash))
8827 (out (derivation->output-path drv))
8828 (sh (string-append out "/bin/bash")))
8829 (build-expression->derivation store "sh"
8830 `(symlink ,sh %output))))
8833 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
8834 as a monadic function:
8837 (define (sh-symlink)
8838 ;; Same, but return a monadic value.
8839 (mlet %store-monad ((drv (package->derivation bash)))
8840 (gexp->derivation "sh"
8841 #~(symlink (string-append #$drv "/bin/bash")
8845 There are several things to note in the second version: the @code{store}
8846 parameter is now implicit and is ``threaded'' in the calls to the
8847 @code{package->derivation} and @code{gexp->derivation} monadic
8848 procedures, and the monadic value returned by @code{package->derivation}
8849 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
8851 As it turns out, the call to @code{package->derivation} can even be
8852 omitted since it will take place implicitly, as we will see later
8853 (@pxref{G-Expressions}):
8856 (define (sh-symlink)
8857 (gexp->derivation "sh"
8858 #~(symlink (string-append #$bash "/bin/bash")
8863 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
8864 @c for the funny quote.
8865 Calling the monadic @code{sh-symlink} has no effect. As someone once
8866 said, ``you exit a monad like you exit a building on fire: by running''.
8867 So, to exit the monad and get the desired effect, one must use
8868 @code{run-with-store}:
8871 (run-with-store (open-connection) (sh-symlink))
8872 @result{} /gnu/store/...-sh-symlink
8875 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
8876 new ``meta-commands'' to make it easier to deal with monadic procedures:
8877 @code{run-in-store}, and @code{enter-store-monad}. The former is used
8878 to ``run'' a single monadic value through the store:
8881 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
8882 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
8885 The latter enters a recursive REPL, where all the return values are
8886 automatically run through the store:
8889 scheme@@(guile-user)> ,enter-store-monad
8890 store-monad@@(guile-user) [1]> (package->derivation hello)
8891 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
8892 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
8893 $3 = "/gnu/store/@dots{}-foo"
8894 store-monad@@(guile-user) [1]> ,q
8895 scheme@@(guile-user)>
8899 Note that non-monadic values cannot be returned in the
8900 @code{store-monad} REPL.
8902 The main syntactic forms to deal with monads in general are provided by
8903 the @code{(guix monads)} module and are described below.
8905 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
8906 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
8910 @deffn {Scheme Syntax} return @var{val}
8911 Return a monadic value that encapsulates @var{val}.
8914 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
8915 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
8916 procedures @var{mproc}@dots{}@footnote{This operation is commonly
8917 referred to as ``bind'', but that name denotes an unrelated procedure in
8918 Guile. Thus we use this somewhat cryptic symbol inherited from the
8919 Haskell language.}. There can be one @var{mproc} or several of them, as
8924 (with-monad %state-monad
8926 (lambda (x) (return (+ 1 x)))
8927 (lambda (x) (return (* 2 x)))))
8931 @result{} some-state
8935 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
8937 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
8939 Bind the variables @var{var} to the monadic values @var{mval} in
8940 @var{body}, which is a sequence of expressions. As with the bind
8941 operator, this can be thought of as ``unpacking'' the raw, non-monadic
8942 value ``contained'' in @var{mval} and making @var{var} refer to that
8943 raw, non-monadic value within the scope of the @var{body}. The form
8944 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
8945 @var{val}, as per @code{let}. The binding operations occur in sequence
8946 from left to right. The last expression of @var{body} must be a monadic
8947 expression, and its result will become the result of the @code{mlet} or
8948 @code{mlet*} when run in the @var{monad}.
8950 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
8951 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
8954 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
8955 Bind @var{mexp} and the following monadic expressions in sequence,
8956 returning the result of the last expression. Every expression in the
8957 sequence must be a monadic expression.
8959 This is akin to @code{mlet}, except that the return values of the
8960 monadic expressions are ignored. In that sense, it is analogous to
8961 @code{begin}, but applied to monadic expressions.
8964 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
8965 When @var{condition} is true, evaluate the sequence of monadic
8966 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
8967 @var{condition} is false, return @code{*unspecified*} in the current
8968 monad. Every expression in the sequence must be a monadic expression.
8971 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
8972 When @var{condition} is false, evaluate the sequence of monadic
8973 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
8974 @var{condition} is true, return @code{*unspecified*} in the current
8975 monad. Every expression in the sequence must be a monadic expression.
8979 The @code{(guix monads)} module provides the @dfn{state monad}, which
8980 allows an additional value---the state---to be @emph{threaded} through
8981 monadic procedure calls.
8983 @defvr {Scheme Variable} %state-monad
8984 The state monad. Procedures in the state monad can access and change
8985 the state that is threaded.
8987 Consider the example below. The @code{square} procedure returns a value
8988 in the state monad. It returns the square of its argument, but also
8989 increments the current state value:
8993 (mlet %state-monad ((count (current-state)))
8994 (mbegin %state-monad
8995 (set-current-state (+ 1 count))
8998 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
9003 When ``run'' through @code{%state-monad}, we obtain that additional state
9004 value, which is the number of @code{square} calls.
9007 @deffn {Monadic Procedure} current-state
9008 Return the current state as a monadic value.
9011 @deffn {Monadic Procedure} set-current-state @var{value}
9012 Set the current state to @var{value} and return the previous state as a
9016 @deffn {Monadic Procedure} state-push @var{value}
9017 Push @var{value} to the current state, which is assumed to be a list,
9018 and return the previous state as a monadic value.
9021 @deffn {Monadic Procedure} state-pop
9022 Pop a value from the current state and return it as a monadic value.
9023 The state is assumed to be a list.
9026 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
9027 Run monadic value @var{mval} starting with @var{state} as the initial
9028 state. Return two values: the resulting value, and the resulting state.
9031 The main interface to the store monad, provided by the @code{(guix
9032 store)} module, is as follows.
9034 @defvr {Scheme Variable} %store-monad
9035 The store monad---an alias for @code{%state-monad}.
9037 Values in the store monad encapsulate accesses to the store. When its
9038 effect is needed, a value of the store monad must be ``evaluated'' by
9039 passing it to the @code{run-with-store} procedure (see below).
9042 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
9043 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
9044 open store connection.
9047 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
9048 Return as a monadic value the absolute file name in the store of the file
9049 containing @var{text}, a string. @var{references} is a list of store items that the
9050 resulting text file refers to; it defaults to the empty list.
9053 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
9054 Return as a monadic value the absolute file name in the store of the file
9055 containing @var{data}, a bytevector. @var{references} is a list of store
9056 items that the resulting binary file refers to; it defaults to the empty list.
9059 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
9060 [#:recursive? #t] [#:select? (const #t)]
9061 Return the name of @var{file} once interned in the store. Use
9062 @var{name} as its store name, or the basename of @var{file} if
9063 @var{name} is omitted.
9065 When @var{recursive?} is true, the contents of @var{file} are added
9066 recursively; if @var{file} designates a flat file and @var{recursive?}
9067 is true, its contents are added, and its permission bits are kept.
9069 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
9070 @var{stat})} for each directory entry, where @var{file} is the entry's
9071 absolute file name and @var{stat} is the result of @code{lstat}; exclude
9072 entries for which @var{select?} does not return true.
9074 The example below adds a file to the store, under two different names:
9077 (run-with-store (open-connection)
9078 (mlet %store-monad ((a (interned-file "README"))
9079 (b (interned-file "README" "LEGU-MIN")))
9080 (return (list a b))))
9082 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
9087 The @code{(guix packages)} module exports the following package-related
9090 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
9091 [#:system (%current-system)] [#:target #f] @
9094 value in the absolute file name of @var{file} within the @var{output}
9095 directory of @var{package}. When @var{file} is omitted, return the name
9096 of the @var{output} directory of @var{package}. When @var{target} is
9097 true, use it as a cross-compilation target triplet.
9099 Note that this procedure does @emph{not} build @var{package}. Thus, the
9100 result might or might not designate an existing file. We recommend not
9101 using this procedure unless you know what you are doing.
9104 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
9105 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
9106 @var{target} [@var{system}]
9107 Monadic version of @code{package-derivation} and
9108 @code{package-cross-derivation} (@pxref{Defining Packages}).
9113 @section G-Expressions
9115 @cindex G-expression
9116 @cindex build code quoting
9117 So we have ``derivations'', which represent a sequence of build actions
9118 to be performed to produce an item in the store (@pxref{Derivations}).
9119 These build actions are performed when asking the daemon to actually
9120 build the derivations; they are run by the daemon in a container
9121 (@pxref{Invoking guix-daemon}).
9123 @cindex code staging
9124 @cindex staging, of code
9125 @cindex strata of code
9126 It should come as no surprise that we like to write these build actions
9127 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
9128 code@footnote{The term @dfn{stratum} in this context was coined by
9129 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
9130 Kiselyov, who has written insightful
9131 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
9132 on this topic}, refers to this kind of code generation as
9133 @dfn{staging}.}: the ``host code''---code that defines packages, talks
9134 to the daemon, etc.---and the ``build code''---code that actually
9135 performs build actions, such as making directories, invoking
9136 @command{make}, and so on (@pxref{Build Phases}).
9138 To describe a derivation and its build actions, one typically needs to
9139 embed build code inside host code. It boils down to manipulating build
9140 code as data, and the homoiconicity of Scheme---code has a direct
9141 representation as data---comes in handy for that. But we need more than
9142 the normal @code{quasiquote} mechanism in Scheme to construct build
9145 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
9146 S-expressions adapted to build expressions. G-expressions, or
9147 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
9148 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
9149 @code{#$}, and @code{#$@@}), which are comparable to
9150 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
9151 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
9152 GNU Guile Reference Manual}). However, there are major differences:
9156 Gexps are meant to be written to a file and run or manipulated by other
9160 When a high-level object such as a package or derivation is unquoted
9161 inside a gexp, the result is as if its output file name had been
9165 Gexps carry information about the packages or derivations they refer to,
9166 and these dependencies are automatically added as inputs to the build
9167 processes that use them.
9170 @cindex lowering, of high-level objects in gexps
9171 This mechanism is not limited to package and derivation
9172 objects: @dfn{compilers} able to ``lower'' other high-level objects to
9173 derivations or files in the store can be defined,
9174 such that these objects can also be inserted
9175 into gexps. For example, a useful type of high-level objects that can be
9176 inserted in a gexp is ``file-like objects'', which make it easy to
9177 add files to the store and to refer to them in
9178 derivations and such (see @code{local-file} and @code{plain-file}
9181 To illustrate the idea, here is an example of a gexp:
9188 (symlink (string-append #$coreutils "/bin/ls")
9192 This gexp can be passed to @code{gexp->derivation}; we obtain a
9193 derivation that builds a directory containing exactly one symlink to
9194 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
9197 (gexp->derivation "the-thing" build-exp)
9200 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
9201 substituted to the reference to the @var{coreutils} package in the
9202 actual build code, and @var{coreutils} is automatically made an input to
9203 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
9204 output)}) is replaced by a string containing the directory name of the
9205 output of the derivation.
9207 @cindex cross compilation
9208 In a cross-compilation context, it is useful to distinguish between
9209 references to the @emph{native} build of a package---that can run on the
9210 host---versus references to cross builds of a package. To that end, the
9211 @code{#+} plays the same role as @code{#$}, but is a reference to a
9212 native package build:
9215 (gexp->derivation "vi"
9218 (mkdir (string-append #$output "/bin"))
9219 (system* (string-append #+coreutils "/bin/ln")
9221 (string-append #$emacs "/bin/emacs")
9222 (string-append #$output "/bin/vi")))
9223 #:target "aarch64-linux-gnu")
9227 In the example above, the native build of @var{coreutils} is used, so
9228 that @command{ln} can actually run on the host; but then the
9229 cross-compiled build of @var{emacs} is referenced.
9231 @cindex imported modules, for gexps
9232 @findex with-imported-modules
9233 Another gexp feature is @dfn{imported modules}: sometimes you want to be
9234 able to use certain Guile modules from the ``host environment'' in the
9235 gexp, so those modules should be imported in the ``build environment''.
9236 The @code{with-imported-modules} form allows you to express that:
9239 (let ((build (with-imported-modules '((guix build utils))
9241 (use-modules (guix build utils))
9242 (mkdir-p (string-append #$output "/bin"))))))
9243 (gexp->derivation "empty-dir"
9246 (display "success!\n")
9251 In this example, the @code{(guix build utils)} module is automatically
9252 pulled into the isolated build environment of our gexp, such that
9253 @code{(use-modules (guix build utils))} works as expected.
9255 @cindex module closure
9256 @findex source-module-closure
9257 Usually you want the @emph{closure} of the module to be imported---i.e.,
9258 the module itself and all the modules it depends on---rather than just
9259 the module; failing to do that, attempts to use the module will fail
9260 because of missing dependent modules. The @code{source-module-closure}
9261 procedure computes the closure of a module by looking at its source file
9262 headers, which comes in handy in this case:
9265 (use-modules (guix modules)) ;for 'source-module-closure'
9267 (with-imported-modules (source-module-closure
9268 '((guix build utils)
9270 (gexp->derivation "something-with-vms"
9272 (use-modules (guix build utils)
9277 @cindex extensions, for gexps
9278 @findex with-extensions
9279 In the same vein, sometimes you want to import not just pure-Scheme
9280 modules, but also ``extensions'' such as Guile bindings to C libraries
9281 or other ``full-blown'' packages. Say you need the @code{guile-json}
9282 package available on the build side, here's how you would do it:
9285 (use-modules (gnu packages guile)) ;for 'guile-json'
9287 (with-extensions (list guile-json)
9288 (gexp->derivation "something-with-json"
9290 (use-modules (json))
9294 The syntactic form to construct gexps is summarized below.
9296 @deffn {Scheme Syntax} #~@var{exp}
9297 @deffnx {Scheme Syntax} (gexp @var{exp})
9298 Return a G-expression containing @var{exp}. @var{exp} may contain one
9299 or more of the following forms:
9303 @itemx (ungexp @var{obj})
9304 Introduce a reference to @var{obj}. @var{obj} may have one of the
9305 supported types, for example a package or a
9306 derivation, in which case the @code{ungexp} form is replaced by its
9307 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
9309 If @var{obj} is a list, it is traversed and references to supported
9310 objects are substituted similarly.
9312 If @var{obj} is another gexp, its contents are inserted and its
9313 dependencies are added to those of the containing gexp.
9315 If @var{obj} is another kind of object, it is inserted as is.
9317 @item #$@var{obj}:@var{output}
9318 @itemx (ungexp @var{obj} @var{output})
9319 This is like the form above, but referring explicitly to the
9320 @var{output} of @var{obj}---this is useful when @var{obj} produces
9321 multiple outputs (@pxref{Packages with Multiple Outputs}).
9324 @itemx #+@var{obj}:output
9325 @itemx (ungexp-native @var{obj})
9326 @itemx (ungexp-native @var{obj} @var{output})
9327 Same as @code{ungexp}, but produces a reference to the @emph{native}
9328 build of @var{obj} when used in a cross compilation context.
9330 @item #$output[:@var{output}]
9331 @itemx (ungexp output [@var{output}])
9332 Insert a reference to derivation output @var{output}, or to the main
9333 output when @var{output} is omitted.
9335 This only makes sense for gexps passed to @code{gexp->derivation}.
9338 @itemx (ungexp-splicing @var{lst})
9339 Like the above, but splices the contents of @var{lst} inside the
9343 @itemx (ungexp-native-splicing @var{lst})
9344 Like the above, but refers to native builds of the objects listed in
9349 G-expressions created by @code{gexp} or @code{#~} are run-time objects
9350 of the @code{gexp?} type (see below).
9353 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
9354 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
9355 in their execution environment.
9357 Each item in @var{modules} can be the name of a module, such as
9358 @code{(guix build utils)}, or it can be a module name, followed by an
9359 arrow, followed by a file-like object:
9362 `((guix build utils)
9364 ((guix config) => ,(scheme-file "config.scm"
9365 #~(define-module @dots{}))))
9369 In the example above, the first two modules are taken from the search
9370 path, and the last one is created from the given file-like object.
9372 This form has @emph{lexical} scope: it has an effect on the gexps
9373 directly defined in @var{body}@dots{}, but not on those defined, say, in
9374 procedures called from @var{body}@dots{}.
9377 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
9378 Mark the gexps defined in @var{body}@dots{} as requiring
9379 @var{extensions} in their build and execution environment.
9380 @var{extensions} is typically a list of package objects such as those
9381 defined in the @code{(gnu packages guile)} module.
9383 Concretely, the packages listed in @var{extensions} are added to the
9384 load path while compiling imported modules in @var{body}@dots{}; they
9385 are also added to the load path of the gexp returned by
9389 @deffn {Scheme Procedure} gexp? @var{obj}
9390 Return @code{#t} if @var{obj} is a G-expression.
9393 G-expressions are meant to be written to disk, either as code building
9394 some derivation, or as plain files in the store. The monadic procedures
9395 below allow you to do that (@pxref{The Store Monad}, for more
9396 information about monads).
9398 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
9399 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
9400 [#:hash #f] [#:hash-algo #f] @
9401 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
9402 [#:module-path @code{%load-path}] @
9403 [#:effective-version "2.2"] @
9404 [#:references-graphs #f] [#:allowed-references #f] @
9405 [#:disallowed-references #f] @
9406 [#:leaked-env-vars #f] @
9407 [#:script-name (string-append @var{name} "-builder")] @
9408 [#:deprecation-warnings #f] @
9409 [#:local-build? #f] [#:substitutable? #t] @
9410 [#:properties '()] [#:guile-for-build #f]
9411 Return a derivation @var{name} that runs @var{exp} (a gexp) with
9412 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
9413 stored in a file called @var{script-name}. When @var{target} is true,
9414 it is used as the cross-compilation target triplet for packages referred
9417 @var{modules} is deprecated in favor of @code{with-imported-modules}.
9419 make @var{modules} available in the evaluation context of @var{exp};
9420 @var{modules} is a list of names of Guile modules searched in
9421 @var{module-path} to be copied in the store, compiled, and made available in
9422 the load path during the execution of @var{exp}---e.g., @code{((guix
9423 build utils) (guix build gnu-build-system))}.
9425 @var{effective-version} determines the string to use when adding extensions of
9426 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
9428 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
9431 When @var{references-graphs} is true, it must be a list of tuples of one of the
9435 (@var{file-name} @var{package})
9436 (@var{file-name} @var{package} @var{output})
9437 (@var{file-name} @var{derivation})
9438 (@var{file-name} @var{derivation} @var{output})
9439 (@var{file-name} @var{store-item})
9442 The right-hand-side of each element of @var{references-graphs} is automatically made
9443 an input of the build process of @var{exp}. In the build environment, each
9444 @var{file-name} contains the reference graph of the corresponding item, in a simple
9447 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
9448 In the latter case, the list denotes store items that the result is allowed to
9449 refer to. Any reference to another store item will lead to a build error.
9450 Similarly for @var{disallowed-references}, which can list items that must not be
9451 referenced by the outputs.
9453 @var{deprecation-warnings} determines whether to show deprecation warnings while
9454 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
9456 The other arguments are as for @code{derivation} (@pxref{Derivations}).
9459 @cindex file-like objects
9460 The @code{local-file}, @code{plain-file}, @code{computed-file},
9461 @code{program-file}, and @code{scheme-file} procedures below return
9462 @dfn{file-like objects}. That is, when unquoted in a G-expression,
9463 these objects lead to a file in the store. Consider this G-expression:
9466 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
9467 #$(local-file "/tmp/my-nscd.conf"))
9470 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
9471 to the store. Once expanded, for instance @i{via}
9472 @code{gexp->derivation}, the G-expression refers to that copy under
9473 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
9474 does not have any effect on what the G-expression does.
9475 @code{plain-file} can be used similarly; it differs in that the file
9476 content is directly passed as a string.
9478 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
9479 [#:recursive? #f] [#:select? (const #t)]
9480 Return an object representing local file @var{file} to add to the store;
9481 this object can be used in a gexp. If @var{file} is a literal string
9482 denoting a relative file name, it is looked up relative to the source
9483 file where it appears; if @var{file} is not a literal string, it is
9484 looked up relative to the current working directory at run time.
9485 @var{file} will be added to the store under @var{name}--by default the
9486 base name of @var{file}.
9488 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
9489 designates a flat file and @var{recursive?} is true, its contents are added, and its
9490 permission bits are kept.
9492 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
9493 @var{stat})} for each directory entry, where @var{file} is the entry's
9494 absolute file name and @var{stat} is the result of @code{lstat}; exclude
9495 entries for which @var{select?} does not return true.
9497 This is the declarative counterpart of the @code{interned-file} monadic
9498 procedure (@pxref{The Store Monad, @code{interned-file}}).
9501 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
9502 Return an object representing a text file called @var{name} with the given
9503 @var{content} (a string or a bytevector) to be added to the store.
9505 This is the declarative counterpart of @code{text-file}.
9508 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
9511 Return an object representing the store item @var{name}, a file or
9512 directory computed by @var{gexp}. When @var{local-build?} is true (the
9513 default), the derivation is built locally. @var{options} is a list of
9514 additional arguments to pass to @code{gexp->derivation}.
9516 This is the declarative counterpart of @code{gexp->derivation}.
9519 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
9520 [#:guile (default-guile)] [#:module-path %load-path] @
9521 [#:system (%current-system)] [#:target #f]
9522 Return an executable script @var{name} that runs @var{exp} using
9523 @var{guile}, with @var{exp}'s imported modules in its search path.
9524 Look up @var{exp}'s modules in @var{module-path}.
9526 The example below builds a script that simply invokes the @command{ls}
9530 (use-modules (guix gexp) (gnu packages base))
9532 (gexp->script "list-files"
9533 #~(execl #$(file-append coreutils "/bin/ls")
9537 When ``running'' it through the store (@pxref{The Store Monad,
9538 @code{run-with-store}}), we obtain a derivation that produces an
9539 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
9542 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
9544 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
9548 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
9549 [#:guile #f] [#:module-path %load-path]
9550 Return an object representing the executable store item @var{name} that
9551 runs @var{gexp}. @var{guile} is the Guile package used to execute that
9552 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
9554 This is the declarative counterpart of @code{gexp->script}.
9557 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
9558 [#:set-load-path? #t] [#:module-path %load-path] @
9560 [#:guile (default-guile)]
9561 Return a derivation that builds a file @var{name} containing @var{exp}.
9562 When @var{splice?} is true, @var{exp} is considered to be a list of
9563 expressions that will be spliced in the resulting file.
9565 When @var{set-load-path?} is true, emit code in the resulting file to
9566 set @code{%load-path} and @code{%load-compiled-path} to honor
9567 @var{exp}'s imported modules. Look up @var{exp}'s modules in
9570 The resulting file holds references to all the dependencies of @var{exp}
9571 or a subset thereof.
9574 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} @
9575 [#:splice? #f] [#:set-load-path? #t]
9576 Return an object representing the Scheme file @var{name} that contains
9579 This is the declarative counterpart of @code{gexp->file}.
9582 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
9583 Return as a monadic value a derivation that builds a text file
9584 containing all of @var{text}. @var{text} may list, in addition to
9585 strings, objects of any type that can be used in a gexp: packages,
9586 derivations, local file objects, etc. The resulting store file holds
9587 references to all these.
9589 This variant should be preferred over @code{text-file} anytime the file
9590 to create will reference items from the store. This is typically the
9591 case when building a configuration file that embeds store file names,
9595 (define (profile.sh)
9596 ;; Return the name of a shell script in the store that
9597 ;; initializes the 'PATH' environment variable.
9598 (text-file* "profile.sh"
9599 "export PATH=" coreutils "/bin:"
9600 grep "/bin:" sed "/bin\n"))
9603 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
9604 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
9605 preventing them from being garbage-collected during its lifetime.
9608 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
9609 Return an object representing store file @var{name} containing
9610 @var{text}. @var{text} is a sequence of strings and file-like objects,
9614 (mixed-text-file "profile"
9615 "export PATH=" coreutils "/bin:" grep "/bin")
9618 This is the declarative counterpart of @code{text-file*}.
9621 @deffn {Scheme Procedure} file-union @var{name} @var{files}
9622 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
9623 Each item in @var{files} must be a two-element list where the first element is the
9624 file name to use in the new directory, and the second element is a gexp
9625 denoting the target file. Here's an example:
9629 `(("hosts" ,(plain-file "hosts"
9630 "127.0.0.1 localhost"))
9631 ("bashrc" ,(plain-file "bashrc"
9632 "alias ls='ls --color=auto'"))))
9635 This yields an @code{etc} directory containing these two files.
9638 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
9639 Return a directory that is the union of @var{things}, where @var{things} is a list of
9640 file-like objects denoting directories. For example:
9643 (directory-union "guile+emacs" (list guile emacs))
9646 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
9649 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
9650 Return a file-like object that expands to the concatenation of @var{obj}
9651 and @var{suffix}, where @var{obj} is a lowerable object and each
9652 @var{suffix} is a string.
9654 As an example, consider this gexp:
9657 (gexp->script "run-uname"
9658 #~(system* #$(file-append coreutils
9662 The same effect could be achieved with:
9665 (gexp->script "run-uname"
9666 #~(system* (string-append #$coreutils
9670 There is one difference though: in the @code{file-append} case, the
9671 resulting script contains the absolute file name as a string, whereas in
9672 the second case, the resulting script contains a @code{(string-append
9673 @dots{})} expression to construct the file name @emph{at run time}.
9676 @deffn {Scheme Syntax} let-system @var{system} @var{body}@dots{}
9677 @deffnx {Scheme Syntax} let-system (@var{system} @var{target}) @var{body}@dots{}
9678 Bind @var{system} to the currently targeted system---e.g.,
9679 @code{"x86_64-linux"}---within @var{body}.
9681 In the second case, additionally bind @var{target} to the current
9682 cross-compilation target---a GNU triplet such as
9683 @code{"arm-linux-gnueabihf"}---or @code{#f} if we are not
9686 @code{let-system} is useful in the occasional case where the object
9687 spliced into the gexp depends on the target system, as in this example:
9691 #+(let-system system
9692 (cond ((string-prefix? "armhf-" system)
9693 (file-append qemu "/bin/qemu-system-arm"))
9694 ((string-prefix? "x86_64-" system)
9695 (file-append qemu "/bin/qemu-system-x86_64"))
9698 "-net" "user" #$image)
9702 @deffn {Scheme Syntax} with-parameters ((@var{parameter} @var{value}) @dots{}) @var{exp}
9703 This macro is similar to the @code{parameterize} form for
9704 dynamically-bound @dfn{parameters} (@pxref{Parameters,,, guile, GNU
9705 Guile Reference Manual}). The key difference is that it takes effect
9706 when the file-like object returned by @var{exp} is lowered to a
9707 derivation or store item.
9709 A typical use of @code{with-parameters} is to force the system in effect
9713 (with-parameters ((%current-system "i686-linux"))
9717 The example above returns an object that corresponds to the i686 build
9718 of Coreutils, regardless of the current value of @code{%current-system}.
9722 Of course, in addition to gexps embedded in ``host'' code, there are
9723 also modules containing build tools. To make it clear that they are
9724 meant to be used in the build stratum, these modules are kept in the
9725 @code{(guix build @dots{})} name space.
9727 @cindex lowering, of high-level objects in gexps
9728 Internally, high-level objects are @dfn{lowered}, using their compiler,
9729 to either derivations or store items. For instance, lowering a package
9730 yields a derivation, and lowering a @code{plain-file} yields a store
9731 item. This is achieved using the @code{lower-object} monadic procedure.
9733 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
9735 Return as a value in @code{%store-monad} the derivation or store item
9736 corresponding to @var{obj} for @var{system}, cross-compiling for
9737 @var{target} if @var{target} is true. @var{obj} must be an object that
9738 has an associated gexp compiler, such as a @code{<package>}.
9741 @node Invoking guix repl
9742 @section Invoking @command{guix repl}
9744 @cindex REPL, read-eval-print loop, script
9745 The @command{guix repl} command makes it easier to program Guix in Guile
9746 by launching a Guile @dfn{read-eval-print loop} (REPL) for interactive
9747 programming (@pxref{Using Guile Interactively,,, guile,
9748 GNU Guile Reference Manual}), or by running Guile scripts
9749 (@pxref{Running Guile Scripts,,, guile,
9750 GNU Guile Reference Manual}).
9751 Compared to just launching the @command{guile}
9752 command, @command{guix repl} guarantees that all the Guix modules and all its
9753 dependencies are available in the search path.
9755 The general syntax is:
9758 guix repl @var{options} [@var{file} @var{args}]
9761 When a @var{file} argument is provided, @var{file} is
9762 executed as a Guile scripts:
9765 guix repl my-script.scm
9768 To pass arguments to the script, use @code{--} to prevent them from
9769 being interpreted as arguments to @command{guix repl} itself:
9772 guix repl -- my-script.scm --input=foo.txt
9775 To make a script executable directly from the shell, using the guix
9776 executable that is on the user's search path, add the following two
9777 lines at the top of the script:
9780 @code{#!/usr/bin/env -S guix repl --}
9784 Without a file name argument, a Guile REPL is started:
9788 scheme@@(guile-user)> ,use (gnu packages base)
9789 scheme@@(guile-user)> coreutils
9790 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
9794 In addition, @command{guix repl} implements a simple machine-readable REPL
9795 protocol for use by @code{(guix inferior)}, a facility to interact with
9796 @dfn{inferiors}, separate processes running a potentially different revision
9799 The available options are as follows:
9802 @item --type=@var{type}
9803 @itemx -t @var{type}
9804 Start a REPL of the given @var{TYPE}, which can be one of the following:
9808 This is default, and it spawns a standard full-featured Guile REPL.
9810 Spawn a REPL that uses the machine-readable protocol. This is the protocol
9811 that the @code{(guix inferior)} module speaks.
9814 @item --listen=@var{endpoint}
9815 By default, @command{guix repl} reads from standard input and writes to
9816 standard output. When this option is passed, it will instead listen for
9817 connections on @var{endpoint}. Here are examples of valid options:
9820 @item --listen=tcp:37146
9821 Accept connections on localhost on port 37146.
9823 @item --listen=unix:/tmp/socket
9824 Accept connections on the Unix-domain socket @file{/tmp/socket}.
9827 @item --load-path=@var{directory}
9828 @itemx -L @var{directory}
9829 Add @var{directory} to the front of the package module search path
9830 (@pxref{Package Modules}).
9832 This allows users to define their own packages and make them visible to
9836 Inhibit loading of the @file{~/.guile} file. By default, that
9837 configuration file is loaded when spawning a @code{guile} REPL.
9840 @c *********************************************************************
9844 This section describes Guix command-line utilities. Some of them are
9845 primarily targeted at developers and users who write new package
9846 definitions, while others are more generally useful. They complement
9847 the Scheme programming interface of Guix in a convenient way.
9850 * Invoking guix build:: Building packages from the command line.
9851 * Invoking guix edit:: Editing package definitions.
9852 * Invoking guix download:: Downloading a file and printing its hash.
9853 * Invoking guix hash:: Computing the cryptographic hash of a file.
9854 * Invoking guix import:: Importing package definitions.
9855 * Invoking guix refresh:: Updating package definitions.
9856 * Invoking guix lint:: Finding errors in package definitions.
9857 * Invoking guix size:: Profiling disk usage.
9858 * Invoking guix graph:: Visualizing the graph of packages.
9859 * Invoking guix publish:: Sharing substitutes.
9860 * Invoking guix challenge:: Challenging substitute servers.
9861 * Invoking guix copy:: Copying to and from a remote store.
9862 * Invoking guix container:: Process isolation.
9863 * Invoking guix weather:: Assessing substitute availability.
9864 * Invoking guix processes:: Listing client processes.
9867 @node Invoking guix build
9868 @section Invoking @command{guix build}
9870 @cindex package building
9871 @cindex @command{guix build}
9872 The @command{guix build} command builds packages or derivations and
9873 their dependencies, and prints the resulting store paths. Note that it
9874 does not modify the user's profile---this is the job of the
9875 @command{guix package} command (@pxref{Invoking guix package}). Thus,
9876 it is mainly useful for distribution developers.
9878 The general syntax is:
9881 guix build @var{options} @var{package-or-derivation}@dots{}
9884 As an example, the following command builds the latest versions of Emacs
9885 and of Guile, displays their build logs, and finally displays the
9886 resulting directories:
9889 guix build emacs guile
9892 Similarly, the following command builds all the available packages:
9895 guix build --quiet --keep-going \
9896 `guix package -A | cut -f1,2 --output-delimiter=@@`
9899 @var{package-or-derivation} may be either the name of a package found in
9900 the software distribution such as @code{coreutils} or
9901 @code{coreutils@@8.20}, or a derivation such as
9902 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
9903 package with the corresponding name (and optionally version) is searched
9904 for among the GNU distribution modules (@pxref{Package Modules}).
9906 Alternatively, the @option{--expression} option may be used to specify a
9907 Scheme expression that evaluates to a package; this is useful when
9908 disambiguating among several same-named packages or package variants is
9911 There may be zero or more @var{options}. The available options are
9912 described in the subsections below.
9915 * Common Build Options:: Build options for most commands.
9916 * Package Transformation Options:: Creating variants of packages.
9917 * Additional Build Options:: Options specific to 'guix build'.
9918 * Debugging Build Failures:: Real life packaging experience.
9921 @node Common Build Options
9922 @subsection Common Build Options
9924 A number of options that control the build process are common to
9925 @command{guix build} and other commands that can spawn builds, such as
9926 @command{guix package} or @command{guix archive}. These are the
9931 @item --load-path=@var{directory}
9932 @itemx -L @var{directory}
9933 Add @var{directory} to the front of the package module search path
9934 (@pxref{Package Modules}).
9936 This allows users to define their own packages and make them visible to
9937 the command-line tools.
9941 Keep the build tree of failed builds. Thus, if a build fails, its build
9942 tree is kept under @file{/tmp}, in a directory whose name is shown at
9943 the end of the build log. This is useful when debugging build issues.
9944 @xref{Debugging Build Failures}, for tips and tricks on how to debug
9947 This option implies @option{--no-offload}, and it has no effect when
9948 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
9949 Store, the @env{GUIX_DAEMON_SOCKET} variable}).
9953 Keep going when some of the derivations fail to build; return only once
9954 all the builds have either completed or failed.
9956 The default behavior is to stop as soon as one of the specified
9957 derivations has failed.
9961 Do not build the derivations.
9963 @anchor{fallback-option}
9965 When substituting a pre-built binary fails, fall back to building
9966 packages locally (@pxref{Substitution Failure}).
9968 @item --substitute-urls=@var{urls}
9969 @anchor{client-substitute-urls}
9970 Consider @var{urls} the whitespace-separated list of substitute source
9971 URLs, overriding the default list of URLs of @command{guix-daemon}
9972 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
9974 This means that substitutes may be downloaded from @var{urls}, provided
9975 they are signed by a key authorized by the system administrator
9976 (@pxref{Substitutes}).
9978 When @var{urls} is the empty string, substitutes are effectively
9981 @item --no-substitutes
9982 Do not use substitutes for build products. That is, always build things
9983 locally instead of allowing downloads of pre-built binaries
9984 (@pxref{Substitutes}).
9987 Do not ``graft'' packages. In practice, this means that package updates
9988 available as grafts are not applied. @xref{Security Updates}, for more
9989 information on grafts.
9991 @item --rounds=@var{n}
9992 Build each derivation @var{n} times in a row, and raise an error if
9993 consecutive build results are not bit-for-bit identical.
9995 This is a useful way to detect non-deterministic builds processes.
9996 Non-deterministic build processes are a problem because they make it
9997 practically impossible for users to @emph{verify} whether third-party
9998 binaries are genuine. @xref{Invoking guix challenge}, for more.
10000 When used in conjunction with @option{--keep-failed}, the differing
10001 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
10002 This makes it easy to look for differences between the two results.
10005 Do not use offload builds to other machines (@pxref{Daemon Offload
10006 Setup}). That is, always build things locally instead of offloading
10007 builds to remote machines.
10009 @item --max-silent-time=@var{seconds}
10010 When the build or substitution process remains silent for more than
10011 @var{seconds}, terminate it and report a build failure.
10013 By default, the daemon's setting is honored (@pxref{Invoking
10014 guix-daemon, @option{--max-silent-time}}).
10016 @item --timeout=@var{seconds}
10017 Likewise, when the build or substitution process lasts for more than
10018 @var{seconds}, terminate it and report a build failure.
10020 By default, the daemon's setting is honored (@pxref{Invoking
10021 guix-daemon, @option{--timeout}}).
10023 @c Note: This option is actually not part of %standard-build-options but
10024 @c most programs honor it.
10025 @cindex verbosity, of the command-line tools
10026 @cindex build logs, verbosity
10027 @item -v @var{level}
10028 @itemx --verbosity=@var{level}
10029 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
10030 output is produced, 1 is for quiet output, and 2 shows all the build log
10031 output on standard error.
10033 @item --cores=@var{n}
10035 Allow the use of up to @var{n} CPU cores for the build. The special
10036 value @code{0} means to use as many CPU cores as available.
10038 @item --max-jobs=@var{n}
10040 Allow at most @var{n} build jobs in parallel. @xref{Invoking
10041 guix-daemon, @option{--max-jobs}}, for details about this option and the
10042 equivalent @command{guix-daemon} option.
10044 @item --debug=@var{level}
10045 Produce debugging output coming from the build daemon. @var{level} must be an
10046 integer between 0 and 5; higher means more verbose output. Setting a level of
10047 4 or more may be helpful when debugging setup issues with the build daemon.
10051 Behind the scenes, @command{guix build} is essentially an interface to
10052 the @code{package-derivation} procedure of the @code{(guix packages)}
10053 module, and to the @code{build-derivations} procedure of the @code{(guix
10054 derivations)} module.
10056 In addition to options explicitly passed on the command line,
10057 @command{guix build} and other @command{guix} commands that support
10058 building honor the @env{GUIX_BUILD_OPTIONS} environment variable.
10060 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
10061 Users can define this variable to a list of command line options that
10062 will automatically be used by @command{guix build} and other
10063 @command{guix} commands that can perform builds, as in the example
10067 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
10070 These options are parsed independently, and the result is appended to
10071 the parsed command-line options.
10075 @node Package Transformation Options
10076 @subsection Package Transformation Options
10078 @cindex package variants
10079 Another set of command-line options supported by @command{guix build}
10080 and also @command{guix package} are @dfn{package transformation
10081 options}. These are options that make it possible to define @dfn{package
10082 variants}---for instance, packages built from different source code.
10083 This is a convenient way to create customized packages on the fly
10084 without having to type in the definitions of package variants
10085 (@pxref{Defining Packages}).
10087 Package transformation options are preserved across upgrades:
10088 @command{guix upgrade} attempts to apply transformation options
10089 initially used when creating the profile to the upgraded packages.
10091 The available options are listed below. Most commands support them and
10092 also support a @option{--help-transform} option that lists all the
10093 available options and a synopsis (these options are not shown in the
10094 @option{--help} output for brevity).
10098 @item --with-source=@var{source}
10099 @itemx --with-source=@var{package}=@var{source}
10100 @itemx --with-source=@var{package}@@@var{version}=@var{source}
10101 Use @var{source} as the source of @var{package}, and @var{version} as
10102 its version number.
10103 @var{source} must be a file name or a URL, as for @command{guix
10104 download} (@pxref{Invoking guix download}).
10106 When @var{package} is omitted,
10107 it is taken to be the package name specified on the
10108 command line that matches the base of @var{source}---e.g.,
10109 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
10110 package is @code{guile}.
10112 Likewise, when @var{version} is omitted, the version string is inferred from
10113 @var{source}; in the previous example, it is @code{2.0.10}.
10115 This option allows users to try out versions of packages other than the
10116 one provided by the distribution. The example below downloads
10117 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
10118 the @code{ed} package:
10121 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
10124 As a developer, @option{--with-source} makes it easy to test release
10128 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
10131 @dots{} or to build from a checkout in a pristine environment:
10134 $ git clone git://git.sv.gnu.org/guix.git
10135 $ guix build guix --with-source=guix@@1.0=./guix
10138 @item --with-input=@var{package}=@var{replacement}
10139 Replace dependency on @var{package} by a dependency on
10140 @var{replacement}. @var{package} must be a package name, and
10141 @var{replacement} must be a package specification such as @code{guile}
10142 or @code{guile@@1.8}.
10144 For instance, the following command builds Guix, but replaces its
10145 dependency on the current stable version of Guile with a dependency on
10146 the legacy version of Guile, @code{guile@@2.0}:
10149 guix build --with-input=guile=guile@@2.0 guix
10152 This is a recursive, deep replacement. So in this example, both
10153 @code{guix} and its dependency @code{guile-json} (which also depends on
10154 @code{guile}) get rebuilt against @code{guile@@2.0}.
10156 This is implemented using the @code{package-input-rewriting} Scheme
10157 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
10159 @item --with-graft=@var{package}=@var{replacement}
10160 This is similar to @option{--with-input} but with an important difference:
10161 instead of rebuilding the whole dependency chain, @var{replacement} is
10162 built and then @dfn{grafted} onto the binaries that were initially
10163 referring to @var{package}. @xref{Security Updates}, for more
10164 information on grafts.
10166 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
10167 and all its dependencies, replacing references to the version of GnuTLS
10168 they currently refer to:
10171 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
10174 This has the advantage of being much faster than rebuilding everything.
10175 But there is a caveat: it works if and only if @var{package} and
10176 @var{replacement} are strictly compatible---for example, if they provide
10177 a library, the application binary interface (ABI) of those libraries
10178 must be compatible. If @var{replacement} is somehow incompatible with
10179 @var{package}, then the resulting package may be unusable. Use with
10182 @cindex debugging info, rebuilding
10183 @item --with-debug-info=@var{package}
10184 Build @var{package} in a way that preserves its debugging info and graft
10185 it onto packages that depend on it. This is useful if @var{package}
10186 does not already provide debugging info as a @code{debug} output
10187 (@pxref{Installing Debugging Files}).
10189 For example, suppose you're experiencing a crash in Inkscape and would
10190 like to see what's up in GLib, a library deep down in Inkscape's
10191 dependency graph. GLib lacks a @code{debug} output, so debugging is
10192 tough. Fortunately, you rebuild GLib with debugging info and tack it on
10196 guix install inkscape --with-debug-info=glib
10199 Only GLib needs to be recompiled so this takes a reasonable amount of
10200 time. @xref{Installing Debugging Files}, for more info.
10203 Under the hood, this option works by passing the @samp{#:strip-binaries?
10204 #f} to the build system of the package of interest (@pxref{Build
10205 Systems}). Most build systems support that option but some do not. In
10206 that case, an error is raised.
10208 Likewise, if a C/C++ package is built without @code{-g} (which is rarely
10209 the case), debugging info will remain unavailable even when
10210 @code{#:strip-binaries?} is false.
10213 @cindex tool chain, changing the build tool chain of a package
10214 @item --with-c-toolchain=@var{package}=@var{toolchain}
10215 This option changes the compilation of @var{package} and everything that
10216 depends on it so that they get built with @var{toolchain} instead of the
10217 default GNU tool chain for C/C++.
10219 Consider this example:
10222 guix build octave-cli \
10223 --with-c-toolchain=fftw=gcc-toolchain@@10 \
10224 --with-c-toolchain=fftwf=gcc-toolchain@@10
10227 The command above builds a variant of the @code{fftw} and @code{fftwf}
10228 packages using version 10 of @code{gcc-toolchain} instead of the default
10229 tool chain, and then builds a variant of the GNU@tie{}Octave
10230 command-line interface using them. GNU@tie{}Octave itself is also built
10231 with @code{gcc-toolchain@@10}.
10233 This other example builds the Hardware Locality (@code{hwloc}) library
10234 and its dependents up to @code{intel-mpi-benchmarks} with the Clang C
10238 guix build --with-c-toolchain=hwloc=clang-toolchain \
10239 intel-mpi-benchmarks
10243 There can be application binary interface (ABI) incompatibilities among
10244 tool chains. This is particularly true of the C++ standard library and
10245 run-time support libraries such as that of OpenMP. By rebuilding all
10246 dependents with the same tool chain, @option{--with-c-toolchain} minimizes
10247 the risks of incompatibility but cannot entirely eliminate them. Choose
10248 @var{package} wisely.
10251 @item --with-git-url=@var{package}=@var{url}
10252 @cindex Git, using the latest commit
10253 @cindex latest commit, building
10254 Build @var{package} from the latest commit of the @code{master} branch of the
10255 Git repository at @var{url}. Git sub-modules of the repository are fetched,
10258 For example, the following command builds the NumPy Python library against the
10259 latest commit of the master branch of Python itself:
10262 guix build python-numpy \
10263 --with-git-url=python=https://github.com/python/cpython
10266 This option can also be combined with @option{--with-branch} or
10267 @option{--with-commit} (see below).
10269 @cindex continuous integration
10270 Obviously, since it uses the latest commit of the given branch, the result of
10271 such a command varies over time. Nevertheless it is a convenient way to
10272 rebuild entire software stacks against the latest commit of one or more
10273 packages. This is particularly useful in the context of continuous
10276 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
10277 consecutive accesses to the same repository. You may want to clean it up once
10278 in a while to save disk space.
10280 @item --with-branch=@var{package}=@var{branch}
10281 Build @var{package} from the latest commit of @var{branch}. If the
10282 @code{source} field of @var{package} is an origin with the @code{git-fetch}
10283 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
10284 repository URL is taken from that @code{source}. Otherwise you have to use
10285 @option{--with-git-url} to specify the URL of the Git repository.
10287 For instance, the following command builds @code{guile-sqlite3} from the
10288 latest commit of its @code{master} branch, and then builds @code{guix} (which
10289 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
10290 specific @code{guile-sqlite3} build:
10293 guix build --with-branch=guile-sqlite3=master cuirass
10296 @item --with-commit=@var{package}=@var{commit}
10297 This is similar to @option{--with-branch}, except that it builds from
10298 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
10299 Git commit SHA1 identifier or a tag.
10301 @cindex test suite, skipping
10302 @item --without-tests=@var{package}
10303 Build @var{package} without running its tests. This can be useful in
10304 situations where you want to skip the lengthy test suite of a
10305 intermediate package, or if a package's test suite fails in a
10306 non-deterministic fashion. It should be used with care because running
10307 the test suite is a good way to ensure a package is working as intended.
10309 Turning off tests leads to a different store item. Consequently, when
10310 using this option, anything that depends on @var{package} must be
10311 rebuilt, as in this example:
10314 guix install --without-tests=python python-notebook
10317 The command above installs @code{python-notebook} on top of
10318 @code{python} built without running its test suite. To do so, it also
10319 rebuilds everything that depends on @code{python}, including
10320 @code{python-notebook} itself.
10322 Internally, @option{--without-tests} relies on changing the
10323 @code{#:tests?} option of a package's @code{check} phase (@pxref{Build
10324 Systems}). Note that some packages use a customized @code{check} phase
10325 that does not respect a @code{#:tests? #f} setting. Therefore,
10326 @option{--without-tests} has no effect on these packages.
10330 Wondering how to achieve the same effect using Scheme code, for example
10331 in your manifest, or how to write your own package transformation?
10332 @xref{Defining Package Variants}, for an overview of the programming
10333 interfaces available.
10335 @node Additional Build Options
10336 @subsection Additional Build Options
10338 The command-line options presented below are specific to @command{guix
10345 Build quietly, without displaying the build log; this is equivalent to
10346 @option{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
10347 (or similar) and can always be retrieved using the @option{--log-file} option.
10349 @item --file=@var{file}
10350 @itemx -f @var{file}
10351 Build the package, derivation, or other file-like object that the code within
10352 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
10354 As an example, @var{file} might contain a package definition like this
10355 (@pxref{Defining Packages}):
10358 @include package-hello.scm
10361 The @var{file} may also contain a JSON representation of one or more
10362 package definitions. Running @code{guix build -f} on @file{hello.json}
10363 with the following contents would result in building the packages
10364 @code{myhello} and @code{greeter}:
10367 @verbatiminclude package-hello.json
10370 @item --manifest=@var{manifest}
10371 @itemx -m @var{manifest}
10372 Build all packages listed in the given @var{manifest}
10373 (@pxref{profile-manifest, @option{--manifest}}).
10375 @item --expression=@var{expr}
10376 @itemx -e @var{expr}
10377 Build the package or derivation @var{expr} evaluates to.
10379 For example, @var{expr} may be @code{(@@ (gnu packages guile)
10380 guile-1.8)}, which unambiguously designates this specific variant of
10381 version 1.8 of Guile.
10383 Alternatively, @var{expr} may be a G-expression, in which case it is used
10384 as a build program passed to @code{gexp->derivation}
10385 (@pxref{G-Expressions}).
10387 Lastly, @var{expr} may refer to a zero-argument monadic procedure
10388 (@pxref{The Store Monad}). The procedure must return a derivation as a
10389 monadic value, which is then passed through @code{run-with-store}.
10393 Build the source derivations of the packages, rather than the packages
10396 For instance, @code{guix build -S gcc} returns something like
10397 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
10400 The returned source tarball is the result of applying any patches and
10401 code snippets specified in the package @code{origin} (@pxref{Defining
10404 Note that @command{guix build -S} compiles the sources only of the
10405 specified packages. They do not include the sources of statically
10406 linked dependencies and by themselves are insufficient for reproducing
10410 Fetch and return the source of @var{package-or-derivation} and all their
10411 dependencies, recursively. This is a handy way to obtain a local copy
10412 of all the source code needed to build @var{packages}, allowing you to
10413 eventually build them even without network access. It is an extension
10414 of the @option{--source} option and can accept one of the following
10415 optional argument values:
10419 This value causes the @option{--sources} option to behave in the same way
10420 as the @option{--source} option.
10423 Build the source derivations of all packages, including any source that
10424 might be listed as @code{inputs}. This is the default value.
10427 $ guix build --sources tzdata
10428 The following derivations will be built:
10429 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
10430 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
10434 Build the source derivations of all packages, as well of all transitive
10435 inputs to the packages. This can be used e.g.@: to
10436 prefetch package source for later offline building.
10439 $ guix build --sources=transitive tzdata
10440 The following derivations will be built:
10441 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
10442 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
10443 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
10444 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
10445 /gnu/store/@dots{}-make-4.1.tar.xz.drv
10446 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
10452 @item --system=@var{system}
10453 @itemx -s @var{system}
10454 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
10455 the system type of the build host. The @command{guix build} command allows
10456 you to repeat this option several times, in which case it builds for all the
10457 specified systems; other commands ignore extraneous @option{-s} options.
10460 The @option{--system} flag is for @emph{native} compilation and must not
10461 be confused with cross-compilation. See @option{--target} below for
10462 information on cross-compilation.
10465 An example use of this is on Linux-based systems, which can emulate
10466 different personalities. For instance, passing
10467 @option{--system=i686-linux} on an @code{x86_64-linux} system or
10468 @option{--system=armhf-linux} on an @code{aarch64-linux} system allows
10469 you to build packages in a complete 32-bit environment.
10472 Building for an @code{armhf-linux} system is unconditionally enabled on
10473 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
10474 allow for this functionality, notably the ThunderX.
10477 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
10478 is enabled (@pxref{Virtualization Services,
10479 @code{qemu-binfmt-service-type}}), you can build for any system for
10480 which a QEMU @code{binfmt_misc} handler is installed.
10482 Builds for a system other than that of the machine you are using can
10483 also be offloaded to a remote machine of the right architecture.
10484 @xref{Daemon Offload Setup}, for more information on offloading.
10486 @item --target=@var{triplet}
10487 @cindex cross-compilation
10488 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
10489 as @code{"aarch64-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
10490 configuration triplets,, autoconf, Autoconf}).
10492 @anchor{build-check}
10494 @cindex determinism, checking
10495 @cindex reproducibility, checking
10496 Rebuild @var{package-or-derivation}, which are already available in the
10497 store, and raise an error if the build results are not bit-for-bit
10500 This mechanism allows you to check whether previously installed
10501 substitutes are genuine (@pxref{Substitutes}), or whether the build result
10502 of a package is deterministic. @xref{Invoking guix challenge}, for more
10503 background information and tools.
10505 When used in conjunction with @option{--keep-failed}, the differing
10506 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
10507 This makes it easy to look for differences between the two results.
10510 @cindex repairing store items
10511 @cindex corruption, recovering from
10512 Attempt to repair the specified store items, if they are corrupt, by
10513 re-downloading or rebuilding them.
10515 This operation is not atomic and thus restricted to @code{root}.
10517 @item --derivations
10519 Return the derivation paths, not the output paths, of the given
10522 @item --root=@var{file}
10523 @itemx -r @var{file}
10524 @cindex GC roots, adding
10525 @cindex garbage collector roots, adding
10526 Make @var{file} a symlink to the result, and register it as a garbage
10529 Consequently, the results of this @command{guix build} invocation are
10530 protected from garbage collection until @var{file} is removed. When
10531 that option is omitted, build results are eligible for garbage
10532 collection as soon as the build completes. @xref{Invoking guix gc}, for
10536 @cindex build logs, access
10537 Return the build log file names or URLs for the given
10538 @var{package-or-derivation}, or raise an error if build logs are
10541 This works regardless of how packages or derivations are specified. For
10542 instance, the following invocations are equivalent:
10545 guix build --log-file `guix build -d guile`
10546 guix build --log-file `guix build guile`
10547 guix build --log-file guile
10548 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
10551 If a log is unavailable locally, and unless @option{--no-substitutes} is
10552 passed, the command looks for a corresponding log on one of the
10553 substitute servers (as specified with @option{--substitute-urls}).
10555 So for instance, imagine you want to see the build log of GDB on MIPS,
10556 but you are actually on an @code{x86_64} machine:
10559 $ guix build --log-file gdb -s aarch64-linux
10560 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
10563 You can freely access a huge library of build logs!
10566 @node Debugging Build Failures
10567 @subsection Debugging Build Failures
10569 @cindex build failures, debugging
10570 When defining a new package (@pxref{Defining Packages}), you will
10571 probably find yourself spending some time debugging and tweaking the
10572 build until it succeeds. To do that, you need to operate the build
10573 commands yourself in an environment as close as possible to the one the
10576 To that end, the first thing to do is to use the @option{--keep-failed}
10577 or @option{-K} option of @command{guix build}, which will keep the
10578 failed build tree in @file{/tmp} or whatever directory you specified as
10579 @env{TMPDIR} (@pxref{Invoking guix build, @option{--keep-failed}}).
10581 From there on, you can @command{cd} to the failed build tree and source
10582 the @file{environment-variables} file, which contains all the
10583 environment variable definitions that were in place when the build
10584 failed. So let's say you're debugging a build failure in package
10585 @code{foo}; a typical session would look like this:
10588 $ guix build foo -K
10589 @dots{} @i{build fails}
10590 $ cd /tmp/guix-build-foo.drv-0
10591 $ source ./environment-variables
10595 Now, you can invoke commands as if you were the daemon (almost) and
10596 troubleshoot your build process.
10598 Sometimes it happens that, for example, a package's tests pass when you
10599 run them manually but they fail when the daemon runs them. This can
10600 happen because the daemon runs builds in containers where, unlike in our
10601 environment above, network access is missing, @file{/bin/sh} does not
10602 exist, etc. (@pxref{Build Environment Setup}).
10604 In such cases, you may need to run inspect the build process from within
10605 a container similar to the one the build daemon creates:
10608 $ guix build -K foo
10610 $ cd /tmp/guix-build-foo.drv-0
10611 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
10612 [env]# source ./environment-variables
10616 Here, @command{guix environment -C} creates a container and spawns a new
10617 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
10618 strace gdb} part adds the @command{strace} and @command{gdb} commands to
10619 the container, which you may find handy while debugging. The
10620 @option{--no-grafts} option makes sure we get the exact same
10621 environment, with ungrafted packages (@pxref{Security Updates}, for more
10624 To get closer to a container like that used by the build daemon, we can
10625 remove @file{/bin/sh}:
10631 (Don't worry, this is harmless: this is all happening in the throw-away
10632 container created by @command{guix environment}.)
10634 The @command{strace} command is probably not in the search path, but we
10638 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
10641 In this way, not only you will have reproduced the environment variables
10642 the daemon uses, you will also be running the build process in a container
10643 similar to the one the daemon uses.
10646 @node Invoking guix edit
10647 @section Invoking @command{guix edit}
10649 @cindex @command{guix edit}
10650 @cindex package definition, editing
10651 So many packages, so many source files! The @command{guix edit} command
10652 facilitates the life of users and packagers by pointing their editor at
10653 the source file containing the definition of the specified packages.
10657 guix edit gcc@@4.9 vim
10661 launches the program specified in the @env{VISUAL} or in the
10662 @env{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
10665 If you are using a Guix Git checkout (@pxref{Building from Git}), or
10666 have created your own packages on @env{GUIX_PACKAGE_PATH}
10667 (@pxref{Package Modules}), you will be able to edit the package
10668 recipes. In other cases, you will be able to examine the read-only recipes
10669 for packages currently in the store.
10671 Instead of @env{GUIX_PACKAGE_PATH}, the command-line option
10672 @option{--load-path=@var{directory}} (or in short @option{-L
10673 @var{directory}}) allows you to add @var{directory} to the front of the
10674 package module search path and so make your own packages visible.
10676 @node Invoking guix download
10677 @section Invoking @command{guix download}
10679 @cindex @command{guix download}
10680 @cindex downloading package sources
10681 When writing a package definition, developers typically need to download
10682 a source tarball, compute its SHA256 hash, and write that
10683 hash in the package definition (@pxref{Defining Packages}). The
10684 @command{guix download} tool helps with this task: it downloads a file
10685 from the given URI, adds it to the store, and prints both its file name
10686 in the store and its SHA256 hash.
10688 The fact that the downloaded file is added to the store saves bandwidth:
10689 when the developer eventually tries to build the newly defined package
10690 with @command{guix build}, the source tarball will not have to be
10691 downloaded again because it is already in the store. It is also a
10692 convenient way to temporarily stash files, which may be deleted
10693 eventually (@pxref{Invoking guix gc}).
10695 The @command{guix download} command supports the same URIs as used in
10696 package definitions. In particular, it supports @code{mirror://} URIs.
10697 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
10698 Guile bindings for GnuTLS are available in the user's environment; when
10699 they are not available, an error is raised. @xref{Guile Preparations,
10700 how to install the GnuTLS bindings for Guile,, gnutls-guile,
10701 GnuTLS-Guile}, for more information.
10703 @command{guix download} verifies HTTPS server certificates by loading
10704 the certificates of X.509 authorities from the directory pointed to by
10705 the @env{SSL_CERT_DIR} environment variable (@pxref{X.509
10706 Certificates}), unless @option{--no-check-certificate} is used.
10708 The following options are available:
10711 @item --hash=@var{algorithm}
10712 @itemx -H @var{algorithm}
10713 Compute a hash using the specified @var{algorithm}. @xref{Invoking guix
10714 hash}, for more information.
10716 @item --format=@var{fmt}
10717 @itemx -f @var{fmt}
10718 Write the hash in the format specified by @var{fmt}. For more
10719 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
10721 @item --no-check-certificate
10722 Do not validate the X.509 certificates of HTTPS servers.
10724 When using this option, you have @emph{absolutely no guarantee} that you
10725 are communicating with the authentic server responsible for the given
10726 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
10728 @item --output=@var{file}
10729 @itemx -o @var{file}
10730 Save the downloaded file to @var{file} instead of adding it to the
10734 @node Invoking guix hash
10735 @section Invoking @command{guix hash}
10737 @cindex @command{guix hash}
10738 The @command{guix hash} command computes the hash of a file.
10739 It is primarily a convenience tool for anyone contributing to the
10740 distribution: it computes the cryptographic hash of a file, which can be
10741 used in the definition of a package (@pxref{Defining Packages}).
10743 The general syntax is:
10746 guix hash @var{option} @var{file}
10749 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
10750 hash of data read from standard input. @command{guix hash} has the
10755 @item --hash=@var{algorithm}
10756 @itemx -H @var{algorithm}
10757 Compute a hash using the specified @var{algorithm}, @code{sha256} by
10760 @var{algorithm} must the name of a cryptographic hash algorithm
10761 supported by Libgcrypt @i{via} Guile-Gcrypt---e.g., @code{sha512} or
10762 @code{sha3-256} (@pxref{Hash Functions,,, guile-gcrypt, Guile-Gcrypt
10763 Reference Manual}).
10765 @item --format=@var{fmt}
10766 @itemx -f @var{fmt}
10767 Write the hash in the format specified by @var{fmt}.
10769 Supported formats: @code{base64}, @code{nix-base32}, @code{base32}, @code{base16}
10770 (@code{hex} and @code{hexadecimal} can be used as well).
10772 If the @option{--format} option is not specified, @command{guix hash}
10773 will output the hash in @code{nix-base32}. This representation is used
10774 in the definitions of packages.
10778 Compute the hash on @var{file} recursively.
10780 In this case, the hash is computed on an archive containing @var{file},
10781 including its children if it is a directory. Some of the metadata of
10782 @var{file} is part of the archive; for instance, when @var{file} is a
10783 regular file, the hash is different depending on whether @var{file} is
10784 executable or not. Metadata such as time stamps has no impact on the
10785 hash (@pxref{Invoking guix archive}).
10786 @c FIXME: Replace xref above with xref to an ``Archive'' section when
10789 @item --exclude-vcs
10791 When combined with @option{--recursive}, exclude version control system
10792 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.).
10795 As an example, here is how you would compute the hash of a Git checkout,
10796 which is useful when using the @code{git-fetch} method (@pxref{origin
10800 $ git clone http://example.org/foo.git
10806 @node Invoking guix import
10807 @section Invoking @command{guix import}
10809 @cindex importing packages
10810 @cindex package import
10811 @cindex package conversion
10812 @cindex Invoking @command{guix import}
10813 The @command{guix import} command is useful for people who would like to
10814 add a package to the distribution with as little work as
10815 possible---a legitimate demand. The command knows of a few
10816 repositories from which it can ``import'' package metadata. The result
10817 is a package definition, or a template thereof, in the format we know
10818 (@pxref{Defining Packages}).
10820 The general syntax is:
10823 guix import @var{importer} @var{options}@dots{}
10826 @var{importer} specifies the source from which to import package
10827 metadata, and @var{options} specifies a package identifier and other
10828 options specific to @var{importer}.
10830 Some of the importers rely on the ability to run the @command{gpgv} command.
10831 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
10834 Currently, the available ``importers'' are:
10838 Import metadata for the given GNU package. This provides a template
10839 for the latest version of that GNU package, including the hash of its
10840 source tarball, and its canonical synopsis and description.
10842 Additional information such as the package dependencies and its
10843 license needs to be figured out manually.
10845 For example, the following command returns a package definition for
10849 guix import gnu hello
10852 Specific command-line options are:
10855 @item --key-download=@var{policy}
10856 As for @command{guix refresh}, specify the policy to handle missing
10857 OpenPGP keys when verifying the package signature. @xref{Invoking guix
10858 refresh, @option{--key-download}}.
10863 Import metadata from the @uref{https://pypi.python.org/, Python Package
10864 Index}. Information is taken from the JSON-formatted description
10865 available at @code{pypi.python.org} and usually includes all the relevant
10866 information, including package dependencies. For maximum efficiency, it
10867 is recommended to install the @command{unzip} utility, so that the
10868 importer can unzip Python wheels and gather data from them.
10870 The command below imports metadata for the @code{itsdangerous} Python
10874 guix import pypi itsdangerous
10880 Traverse the dependency graph of the given upstream package recursively
10881 and generate package expressions for all those packages that are not yet
10887 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
10888 is taken from the JSON-formatted description available at
10889 @code{rubygems.org} and includes most relevant information, including
10890 runtime dependencies. There are some caveats, however. The metadata
10891 doesn't distinguish between synopses and descriptions, so the same string
10892 is used for both fields. Additionally, the details of non-Ruby
10893 dependencies required to build native extensions is unavailable and left
10894 as an exercise to the packager.
10896 The command below imports metadata for the @code{rails} Ruby package:
10899 guix import gem rails
10905 Traverse the dependency graph of the given upstream package recursively
10906 and generate package expressions for all those packages that are not yet
10912 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
10913 Information is taken from the JSON-formatted metadata provided through
10914 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
10915 relevant information, such as module dependencies. License information
10916 should be checked closely. If Perl is available in the store, then the
10917 @code{corelist} utility will be used to filter core modules out of the
10918 list of dependencies.
10920 The command command below imports metadata for the Acme::Boolean Perl
10924 guix import cpan Acme::Boolean
10929 @cindex Bioconductor
10930 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
10931 central repository for the @uref{https://r-project.org, GNU@tie{}R
10932 statistical and graphical environment}.
10934 Information is extracted from the @file{DESCRIPTION} file of the package.
10936 The command command below imports metadata for the Cairo R package:
10939 guix import cran Cairo
10942 When @option{--recursive} is added, the importer will traverse the
10943 dependency graph of the given upstream package recursively and generate
10944 package expressions for all those packages that are not yet in Guix.
10946 When @option{--archive=bioconductor} is added, metadata is imported from
10947 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
10948 packages for the analysis and comprehension of high-throughput
10949 genomic data in bioinformatics.
10951 Information is extracted from the @file{DESCRIPTION} file contained in the
10954 The command below imports metadata for the GenomicRanges R package:
10957 guix import cran --archive=bioconductor GenomicRanges
10960 Finally, you can also import R packages that have not yet been published on
10961 CRAN or Bioconductor as long as they are in a git repository. Use
10962 @option{--archive=git} followed by the URL of the git repository:
10965 guix import cran --archive=git https://github.com/immunogenomics/harmony
10971 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
10972 comprehensive TeX archive network for TeX packages that are part of the
10973 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
10975 Information about the package is obtained through the XML API provided
10976 by CTAN, while the source code is downloaded from the SVN repository of
10977 the Tex Live project. This is done because the CTAN does not keep
10978 versioned archives.
10980 The command command below imports metadata for the @code{fontspec}
10984 guix import texlive fontspec
10987 When @option{--archive=@var{directory}} is added, the source code is
10988 downloaded not from the @file{latex} sub-directory of the
10989 @file{texmf-dist/source} tree in the TeX Live SVN repository, but from
10990 the specified sibling @var{directory} under the same root.
10992 The command below imports metadata for the @code{ifxetex} package from
10993 CTAN while fetching the sources from the directory
10994 @file{texmf/source/generic}:
10997 guix import texlive --archive=generic ifxetex
11001 @cindex JSON, import
11002 Import package metadata from a local JSON file. Consider the following
11003 example package definition in JSON format:
11009 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
11010 "build-system": "gnu",
11011 "home-page": "https://www.gnu.org/software/hello/",
11012 "synopsis": "Hello, GNU world: An example GNU package",
11013 "description": "GNU Hello prints a greeting.",
11014 "license": "GPL-3.0+",
11015 "native-inputs": ["gettext"]
11019 The field names are the same as for the @code{<package>} record
11020 (@xref{Defining Packages}). References to other packages are provided
11021 as JSON lists of quoted package specification strings such as
11022 @code{guile} or @code{guile@@2.0}.
11024 The importer also supports a more explicit source definition using the
11025 common fields for @code{<origin>} records:
11031 "method": "url-fetch",
11032 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
11034 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
11041 The command below reads metadata from the JSON file @code{hello.json}
11042 and outputs a package expression:
11045 guix import json hello.json
11049 Import metadata from a local copy of the source of the
11050 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
11051 relies on the @command{nix-instantiate} command of
11052 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
11053 typically written in a mixture of Nix-language and Bash code. This
11054 command only imports the high-level package structure that is written in
11055 the Nix language. It normally includes all the basic fields of a
11056 package definition.
11058 When importing a GNU package, the synopsis and descriptions are replaced
11059 by their canonical upstream variant.
11061 Usually, you will first need to do:
11064 export NIX_REMOTE=daemon
11068 so that @command{nix-instantiate} does not try to open the Nix database.
11070 As an example, the command below imports the package definition of
11071 LibreOffice (more precisely, it imports the definition of the package
11072 bound to the @code{libreoffice} top-level attribute):
11075 guix import nix ~/path/to/nixpkgs libreoffice
11080 Import metadata from the Haskell community's central package archive
11081 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
11082 Cabal files and includes all the relevant information, including package
11085 Specific command-line options are:
11090 Read a Cabal file from standard input.
11091 @item --no-test-dependencies
11093 Do not include dependencies required only by the test suites.
11094 @item --cabal-environment=@var{alist}
11095 @itemx -e @var{alist}
11096 @var{alist} is a Scheme alist defining the environment in which the
11097 Cabal conditionals are evaluated. The accepted keys are: @code{os},
11098 @code{arch}, @code{impl} and a string representing the name of a flag.
11099 The value associated with a flag has to be either the symbol
11100 @code{true} or @code{false}. The value associated with other keys
11101 has to conform to the Cabal file format definition. The default value
11102 associated with the keys @code{os}, @code{arch} and @code{impl} is
11103 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
11106 Traverse the dependency graph of the given upstream package recursively
11107 and generate package expressions for all those packages that are not yet
11111 The command below imports metadata for the latest version of the
11112 HTTP Haskell package without including test dependencies and
11113 specifying the value of the flag @samp{network-uri} as @code{false}:
11116 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
11119 A specific package version may optionally be specified by following the
11120 package name by an at-sign and a version number as in the following example:
11123 guix import hackage mtl@@2.1.3.1
11128 The @code{stackage} importer is a wrapper around the @code{hackage} one.
11129 It takes a package name, looks up the package version included in a
11130 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
11131 release and uses the @code{hackage} importer to retrieve its metadata.
11132 Note that it is up to you to select an LTS release compatible with the
11133 GHC compiler used by Guix.
11135 Specific command-line options are:
11138 @item --no-test-dependencies
11140 Do not include dependencies required only by the test suites.
11141 @item --lts-version=@var{version}
11142 @itemx -l @var{version}
11143 @var{version} is the desired LTS release version. If omitted the latest
11147 Traverse the dependency graph of the given upstream package recursively
11148 and generate package expressions for all those packages that are not yet
11152 The command below imports metadata for the HTTP Haskell package
11153 included in the LTS Stackage release version 7.18:
11156 guix import stackage --lts-version=7.18 HTTP
11161 Import metadata from an Emacs Lisp Package Archive (ELPA) package
11162 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
11164 Specific command-line options are:
11167 @item --archive=@var{repo}
11168 @itemx -a @var{repo}
11169 @var{repo} identifies the archive repository from which to retrieve the
11170 information. Currently the supported repositories and their identifiers
11174 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
11175 identifier. This is the default.
11177 Packages from @code{elpa.gnu.org} are signed with one of the keys
11178 contained in the GnuPG keyring at
11179 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
11180 @code{emacs} package (@pxref{Package Installation, ELPA package
11181 signatures,, emacs, The GNU Emacs Manual}).
11184 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
11185 @code{melpa-stable} identifier.
11188 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
11194 Traverse the dependency graph of the given upstream package recursively
11195 and generate package expressions for all those packages that are not yet
11201 Import metadata from the crates.io Rust package repository
11202 @uref{https://crates.io, crates.io}, as in this example:
11205 guix import crate blake2-rfc
11208 The crate importer also allows you to specify a version string:
11211 guix import crate constant-time-eq@@0.1.0
11214 Additional options include:
11219 Traverse the dependency graph of the given upstream package recursively
11220 and generate package expressions for all those packages that are not yet
11227 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
11228 repository used by the OCaml community.
11231 The structure of the @command{guix import} code is modular. It would be
11232 useful to have more importers for other package formats, and your help
11233 is welcome here (@pxref{Contributing}).
11235 @node Invoking guix refresh
11236 @section Invoking @command{guix refresh}
11238 @cindex @command {guix refresh}
11239 The primary audience of the @command{guix refresh} command is developers
11240 of the GNU software distribution. By default, it reports any packages
11241 provided by the distribution that are outdated compared to the latest
11242 upstream version, like this:
11246 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
11247 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
11250 Alternatively, one can specify packages to consider, in which case a
11251 warning is emitted for packages that lack an updater:
11254 $ guix refresh coreutils guile guile-ssh
11255 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
11256 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
11259 @command{guix refresh} browses the upstream repository of each package and determines
11260 the highest version number of the releases therein. The command
11261 knows how to update specific types of packages: GNU packages, ELPA
11262 packages, etc.---see the documentation for @option{--type} below. There
11263 are many packages, though, for which it lacks a method to determine
11264 whether a new upstream release is available. However, the mechanism is
11265 extensible, so feel free to get in touch with us to add a new method!
11270 Consider the packages specified, and all the packages upon which they depend.
11273 $ guix refresh --recursive coreutils
11274 gnu/packages/acl.scm:35:2: warning: no updater for acl
11275 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
11276 gnu/packages/xml.scm:68:2: warning: no updater for expat
11277 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
11283 Sometimes the upstream name differs from the package name used in Guix,
11284 and @command{guix refresh} needs a little help. Most updaters honor the
11285 @code{upstream-name} property in package definitions, which can be used
11289 (define-public network-manager
11291 (name "network-manager")
11293 (properties '((upstream-name . "NetworkManager")))))
11296 When passed @option{--update}, it modifies distribution source files to
11297 update the version numbers and source tarball hashes of those package
11298 recipes (@pxref{Defining Packages}). This is achieved by downloading
11299 each package's latest source tarball and its associated OpenPGP
11300 signature, authenticating the downloaded tarball against its signature
11301 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
11302 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
11305 key used to sign the tarball is missing from the user's keyring, an
11306 attempt is made to automatically retrieve it from a public key server;
11307 when this is successful, the key is added to the user's keyring; otherwise,
11308 @command{guix refresh} reports an error.
11310 The following options are supported:
11314 @item --expression=@var{expr}
11315 @itemx -e @var{expr}
11316 Consider the package @var{expr} evaluates to.
11318 This is useful to precisely refer to a package, as in this example:
11321 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
11324 This command lists the dependents of the ``final'' libc (essentially all
11329 Update distribution source files (package recipes) in place. This is
11330 usually run from a checkout of the Guix source tree (@pxref{Running
11331 Guix Before It Is Installed}):
11334 $ ./pre-inst-env guix refresh -s non-core -u
11337 @xref{Defining Packages}, for more information on package definitions.
11339 @item --select=[@var{subset}]
11340 @itemx -s @var{subset}
11341 Select all the packages in @var{subset}, one of @code{core} or
11344 The @code{core} subset refers to all the packages at the core of the
11345 distribution---i.e., packages that are used to build ``everything
11346 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
11347 changing one of these packages in the distribution entails a rebuild of
11348 all the others. Thus, such updates are an inconvenience to users in
11349 terms of build time or bandwidth used to achieve the upgrade.
11351 The @code{non-core} subset refers to the remaining packages. It is
11352 typically useful in cases where an update of the core packages would be
11355 @item --manifest=@var{file}
11356 @itemx -m @var{file}
11357 Select all the packages from the manifest in @var{file}. This is useful to
11358 check if any packages of the user manifest can be updated.
11360 @item --type=@var{updater}
11361 @itemx -t @var{updater}
11362 Select only packages handled by @var{updater} (may be a comma-separated
11363 list of updaters). Currently, @var{updater} may be one of:
11367 the updater for GNU packages;
11369 the updater for packages hosted at @uref{https://savannah.gnu.org, Savannah};
11371 the updater for GNOME packages;
11373 the updater for KDE packages;
11375 the updater for X.org packages;
11377 the updater for packages hosted on kernel.org;
11379 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
11381 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
11383 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
11385 the updater for @uref{https://www.cpan.org/, CPAN} packages;
11387 the updater for @uref{https://pypi.python.org, PyPI} packages.
11389 the updater for @uref{https://rubygems.org, RubyGems} packages.
11391 the updater for @uref{https://github.com, GitHub} packages.
11393 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
11395 the updater for @uref{https://www.stackage.org, Stackage} packages.
11397 the updater for @uref{https://crates.io, Crates} packages.
11399 the updater for @uref{https://launchpad.net, Launchpad} packages.
11402 For instance, the following command only checks for updates of Emacs
11403 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
11406 $ guix refresh --type=elpa,cran
11407 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
11408 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
11413 In addition, @command{guix refresh} can be passed one or more package
11414 names, as in this example:
11417 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
11421 The command above specifically updates the @code{emacs} and
11422 @code{idutils} packages. The @option{--select} option would have no
11423 effect in this case.
11425 When considering whether to upgrade a package, it is sometimes
11426 convenient to know which packages would be affected by the upgrade and
11427 should be checked for compatibility. For this the following option may
11428 be used when passing @command{guix refresh} one or more package names:
11432 @item --list-updaters
11434 List available updaters and exit (see @option{--type} above).
11436 For each updater, display the fraction of packages it covers; at the
11437 end, display the fraction of packages covered by all these updaters.
11439 @item --list-dependent
11441 List top-level dependent packages that would need to be rebuilt as a
11442 result of upgrading one or more packages.
11444 @xref{Invoking guix graph, the @code{reverse-package} type of
11445 @command{guix graph}}, for information on how to visualize the list of
11446 dependents of a package.
11450 Be aware that the @option{--list-dependent} option only
11451 @emph{approximates} the rebuilds that would be required as a result of
11452 an upgrade. More rebuilds might be required under some circumstances.
11455 $ guix refresh --list-dependent flex
11456 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
11457 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
11460 The command above lists a set of packages that could be built to check
11461 for compatibility with an upgraded @code{flex} package.
11465 @item --list-transitive
11466 List all the packages which one or more packages depend upon.
11469 $ guix refresh --list-transitive flex
11470 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
11471 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{}
11476 The command above lists a set of packages which, when changed, would cause
11477 @code{flex} to be rebuilt.
11479 The following options can be used to customize GnuPG operation:
11483 @item --gpg=@var{command}
11484 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
11485 for in @code{$PATH}.
11487 @item --keyring=@var{file}
11488 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
11489 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
11490 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
11491 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
11492 information on a tool to manipulate keybox files).
11494 When this option is omitted, @command{guix refresh} uses
11495 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
11496 signing keys. OpenPGP signatures are checked against keys from this keyring;
11497 missing keys are downloaded to this keyring as well (see
11498 @option{--key-download} below).
11500 You can export keys from your default GPG keyring into a keybox file using
11501 commands like this one:
11504 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
11507 Likewise, you can fetch keys to a specific keybox file like this:
11510 gpg --no-default-keyring --keyring mykeyring.kbx \
11511 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
11514 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
11515 Privacy Guard}, for more information on GPG's @option{--keyring} option.
11517 @item --key-download=@var{policy}
11518 Handle missing OpenPGP keys according to @var{policy}, which may be one
11523 Always download missing OpenPGP keys from the key server, and add them
11524 to the user's GnuPG keyring.
11527 Never try to download missing OpenPGP keys. Instead just bail out.
11530 When a package signed with an unknown OpenPGP key is encountered, ask
11531 the user whether to download it or not. This is the default behavior.
11534 @item --key-server=@var{host}
11535 Use @var{host} as the OpenPGP key server when importing a public key.
11537 @item --load-path=@var{directory}
11538 Add @var{directory} to the front of the package module search path
11539 (@pxref{Package Modules}).
11541 This allows users to define their own packages and make them visible to
11542 the command-line tools.
11546 The @code{github} updater uses the
11547 @uref{https://developer.github.com/v3/, GitHub API} to query for new
11548 releases. When used repeatedly e.g.@: when refreshing all packages,
11549 GitHub will eventually refuse to answer any further API requests. By
11550 default 60 API requests per hour are allowed, and a full refresh on all
11551 GitHub packages in Guix requires more than this. Authentication with
11552 GitHub through the use of an API token alleviates these limits. To use
11553 an API token, set the environment variable @env{GUIX_GITHUB_TOKEN} to a
11554 token procured from @uref{https://github.com/settings/tokens} or
11558 @node Invoking guix lint
11559 @section Invoking @command{guix lint}
11561 @cindex @command{guix lint}
11562 @cindex package, checking for errors
11563 The @command{guix lint} command is meant to help package developers avoid
11564 common errors and use a consistent style. It runs a number of checks on
11565 a given set of packages in order to find common mistakes in their
11566 definitions. Available @dfn{checkers} include (see
11567 @option{--list-checkers} for a complete list):
11572 Validate certain typographical and stylistic rules about package
11573 descriptions and synopses.
11575 @item inputs-should-be-native
11576 Identify inputs that should most likely be native inputs.
11582 @itemx source-file-name
11583 Probe @code{home-page} and @code{source} URLs and report those that are
11584 invalid. Suggest a @code{mirror://} URL when applicable. If the
11585 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
11586 URL. Check that the source file name is meaningful, e.g.@: is not just a
11587 version number or ``git-checkout'', without a declared @code{file-name}
11588 (@pxref{origin Reference}).
11590 @item source-unstable-tarball
11591 Parse the @code{source} URL to determine if a tarball from GitHub is
11592 autogenerated or if it is a release tarball. Unfortunately GitHub's
11593 autogenerated tarballs are sometimes regenerated.
11596 Check that the derivation of the given packages can be successfully
11597 computed for all the supported systems (@pxref{Derivations}).
11599 @item profile-collisions
11600 Check whether installing the given packages in a profile would lead to
11601 collisions. Collisions occur when several packages with the same name
11602 but a different version or a different store file name are propagated.
11603 @xref{package Reference, @code{propagated-inputs}}, for more information
11604 on propagated inputs.
11607 @cindex Software Heritage, source code archive
11608 @cindex archival of source code, Software Heritage
11609 Checks whether the package's source code is archived at
11610 @uref{https://www.softwareheritage.org, Software Heritage}.
11612 When the source code that is not archived comes from a version-control system
11613 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
11614 ``save'' request so that it eventually archives it. This ensures that the
11615 source will remain available in the long term, and that Guix can fall back to
11616 Software Heritage should the source code disappear from its original host.
11617 The status of recent ``save'' requests can be
11618 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
11620 When source code is a tarball obtained with @code{url-fetch}, simply print a
11621 message when it is not archived. As of this writing, Software Heritage does
11622 not allow requests to save arbitrary tarballs; we are working on ways to
11623 ensure that non-VCS source code is also archived.
11626 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
11627 request rate per IP address}. When the limit is reached, @command{guix lint}
11628 prints a message and the @code{archival} checker stops doing anything until
11629 that limit has been reset.
11632 @cindex security vulnerabilities
11633 @cindex CVE, Common Vulnerabilities and Exposures
11634 Report known vulnerabilities found in the Common Vulnerabilities and
11635 Exposures (CVE) databases of the current and past year
11636 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
11639 To view information about a particular vulnerability, visit pages such as:
11643 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
11645 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
11649 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
11650 @code{CVE-2015-7554}.
11652 Package developers can specify in package recipes the
11653 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
11654 name and version of the package when they differ from the name or version
11655 that Guix uses, as in this example:
11661 ;; CPE calls this package "grub2".
11662 (properties '((cpe-name . "grub2")
11663 (cpe-version . "2.3"))))
11666 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
11667 Some entries in the CVE database do not specify which version of a
11668 package they apply to, and would thus ``stick around'' forever. Package
11669 developers who found CVE alerts and verified they can be ignored can
11670 declare them as in this example:
11676 ;; These CVEs no longer apply and can be safely ignored.
11677 (properties `((lint-hidden-cve . ("CVE-2011-0433"
11680 "CVE-2011-5244")))))
11684 Warn about obvious source code formatting issues: trailing white space,
11685 use of tabulations, etc.
11688 The general syntax is:
11691 guix lint @var{options} @var{package}@dots{}
11694 If no package is given on the command line, then all packages are checked.
11695 The @var{options} may be zero or more of the following:
11698 @item --list-checkers
11700 List and describe all the available checkers that will be run on packages
11705 Only enable the checkers specified in a comma-separated list using the
11706 names returned by @option{--list-checkers}.
11710 Only disable the checkers specified in a comma-separated list using the
11711 names returned by @option{--list-checkers}.
11715 Only enable the checkers that do not depend on Internet access.
11717 @item --load-path=@var{directory}
11718 @itemx -L @var{directory}
11719 Add @var{directory} to the front of the package module search path
11720 (@pxref{Package Modules}).
11722 This allows users to define their own packages and make them visible to
11723 the command-line tools.
11727 @node Invoking guix size
11728 @section Invoking @command{guix size}
11731 @cindex package size
11733 @cindex @command{guix size}
11734 The @command{guix size} command helps package developers profile the
11735 disk usage of packages. It is easy to overlook the impact of an
11736 additional dependency added to a package, or the impact of using a
11737 single output for a package that could easily be split (@pxref{Packages
11738 with Multiple Outputs}). Such are the typical issues that
11739 @command{guix size} can highlight.
11741 The command can be passed one or more package specifications
11742 such as @code{gcc@@4.8}
11743 or @code{guile:debug}, or a file name in the store. Consider this
11747 $ guix size coreutils
11748 store item total self
11749 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
11750 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
11751 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
11752 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
11753 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
11754 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
11755 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
11756 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
11761 The store items listed here constitute the @dfn{transitive closure} of
11762 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
11763 would be returned by:
11766 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
11769 Here the output shows three columns next to store items. The first column,
11770 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
11771 the store item---that is, its own size plus the size of all its
11772 dependencies. The next column, labeled ``self'', shows the size of the
11773 item itself. The last column shows the ratio of the size of the item
11774 itself to the space occupied by all the items listed here.
11776 In this example, we see that the closure of Coreutils weighs in at
11777 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
11778 libraries. (That libc and GCC's libraries represent a large fraction of
11779 the closure is not a problem @i{per se} because they are always available
11780 on the system anyway.)
11782 Since the command also accepts store file names, assessing the size of
11783 a build result is straightforward:
11786 guix size $(guix system build config.scm)
11789 When the package(s) passed to @command{guix size} are available in the
11790 store@footnote{More precisely, @command{guix size} looks for the
11791 @emph{ungrafted} variant of the given package(s), as returned by
11792 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
11793 for information on grafts.}, @command{guix size} queries the daemon to determine its
11794 dependencies, and measures its size in the store, similar to @command{du
11795 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
11798 When the given packages are @emph{not} in the store, @command{guix size}
11799 reports information based on the available substitutes
11800 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
11801 store items that are not even on disk, only available remotely.
11803 You can also specify several package names:
11806 $ guix size coreutils grep sed bash
11807 store item total self
11808 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
11809 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
11810 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
11811 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
11817 In this example we see that the combination of the four packages takes
11818 102.3@tie{}MiB in total, which is much less than the sum of each closure
11819 since they have a lot of dependencies in common.
11821 When looking at the profile returned by @command{guix size}, you may
11822 find yourself wondering why a given package shows up in the profile at
11823 all. To understand it, you can use @command{guix graph --path -t
11824 references} to display the shortest path between the two packages
11825 (@pxref{Invoking guix graph}).
11827 The available options are:
11831 @item --substitute-urls=@var{urls}
11832 Use substitute information from @var{urls}.
11833 @xref{client-substitute-urls, the same option for @code{guix build}}.
11835 @item --sort=@var{key}
11836 Sort lines according to @var{key}, one of the following options:
11840 the size of each item (the default);
11842 the total size of the item's closure.
11845 @item --map-file=@var{file}
11846 Write a graphical map of disk usage in PNG format to @var{file}.
11848 For the example above, the map looks like this:
11850 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
11851 produced by @command{guix size}}
11853 This option requires that
11854 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
11855 installed and visible in Guile's module search path. When that is not
11856 the case, @command{guix size} fails as it tries to load it.
11858 @item --system=@var{system}
11859 @itemx -s @var{system}
11860 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
11862 @item --load-path=@var{directory}
11863 @itemx -L @var{directory}
11864 Add @var{directory} to the front of the package module search path
11865 (@pxref{Package Modules}).
11867 This allows users to define their own packages and make them visible to
11868 the command-line tools.
11871 @node Invoking guix graph
11872 @section Invoking @command{guix graph}
11875 @cindex @command{guix graph}
11876 @cindex package dependencies
11877 Packages and their dependencies form a @dfn{graph}, specifically a
11878 directed acyclic graph (DAG). It can quickly become difficult to have a
11879 mental model of the package DAG, so the @command{guix graph} command
11880 provides a visual representation of the DAG. By default,
11881 @command{guix graph} emits a DAG representation in the input format of
11882 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
11883 directly to the @command{dot} command of Graphviz. It can also emit an
11884 HTML page with embedded JavaScript code to display a ``chord diagram''
11885 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
11886 emit Cypher queries to construct a graph in a graph database supporting
11887 the @uref{https://www.opencypher.org/, openCypher} query language. With
11888 @option{--path}, it simply displays the shortest path between two
11889 packages. The general syntax is:
11892 guix graph @var{options} @var{package}@dots{}
11895 For example, the following command generates a PDF file representing the
11896 package DAG for the GNU@tie{}Core Utilities, showing its build-time
11900 guix graph coreutils | dot -Tpdf > dag.pdf
11903 The output looks like this:
11905 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
11907 Nice little graph, no?
11909 You may find it more pleasant to navigate the graph interactively with
11910 @command{xdot} (from the @code{xdot} package):
11913 guix graph coreutils | xdot -
11916 But there is more than one graph! The one above is concise: it is the
11917 graph of package objects, omitting implicit inputs such as GCC, libc,
11918 grep, etc. It is often useful to have such a concise graph, but
11919 sometimes one may want to see more details. @command{guix graph} supports
11920 several types of graphs, allowing you to choose the level of detail:
11924 This is the default type used in the example above. It shows the DAG of
11925 package objects, excluding implicit dependencies. It is concise, but
11926 filters out many details.
11928 @item reverse-package
11929 This shows the @emph{reverse} DAG of packages. For example:
11932 guix graph --type=reverse-package ocaml
11935 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
11936 you are also interested in cases where OCaml is an implicit dependency, see
11937 @code{reverse-bag} below).
11939 Note that for core packages this can yield huge graphs. If all you want
11940 is to know the number of packages that depend on a given package, use
11941 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
11942 @option{--list-dependent}}).
11945 This is the package DAG, @emph{including} implicit inputs.
11947 For instance, the following command:
11950 guix graph --type=bag-emerged coreutils
11953 ...@: yields this bigger graph:
11955 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
11957 At the bottom of the graph, we see all the implicit inputs of
11958 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
11960 Now, note that the dependencies of these implicit inputs---that is, the
11961 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
11962 here, for conciseness.
11965 Similar to @code{bag-emerged}, but this time including all the bootstrap
11968 @item bag-with-origins
11969 Similar to @code{bag}, but also showing origins and their dependencies.
11972 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
11973 it also takes implicit dependencies into account. For example:
11976 guix graph -t reverse-bag dune
11980 ...@: yields the graph of all packages that depend on Dune, directly or
11981 indirectly. Since Dune is an @emph{implicit} dependency of many packages
11982 @i{via} @code{dune-build-system}, this shows a large number of packages,
11983 whereas @code{reverse-package} would show very few if any.
11986 This is the most detailed representation: It shows the DAG of
11987 derivations (@pxref{Derivations}) and plain store items. Compared to
11988 the above representation, many additional nodes are visible, including
11989 build scripts, patches, Guile modules, etc.
11991 For this type of graph, it is also possible to pass a @file{.drv} file
11992 name instead of a package name, as in:
11995 guix graph -t derivation `guix system build -d my-config.scm`
11999 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
12000 For example, the following command shows the graph for the package
12001 module that defines the @code{guile} package:
12004 guix graph -t module guile | xdot -
12008 All the types above correspond to @emph{build-time dependencies}. The
12009 following graph type represents the @emph{run-time dependencies}:
12013 This is the graph of @dfn{references} of a package output, as returned
12014 by @command{guix gc --references} (@pxref{Invoking guix gc}).
12016 If the given package output is not available in the store, @command{guix
12017 graph} attempts to obtain dependency information from substitutes.
12019 Here you can also pass a store file name instead of a package name. For
12020 example, the command below produces the reference graph of your profile
12021 (which can be big!):
12024 guix graph -t references `readlink -f ~/.guix-profile`
12028 This is the graph of the @dfn{referrers} of a store item, as returned by
12029 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
12031 This relies exclusively on local information from your store. For
12032 instance, let us suppose that the current Inkscape is available in 10
12033 profiles on your machine; @command{guix graph -t referrers inkscape}
12034 will show a graph rooted at Inkscape and with those 10 profiles linked
12037 It can help determine what is preventing a store item from being garbage
12042 @cindex shortest path, between packages
12043 Often, the graph of the package you are interested in does not fit on
12044 your screen, and anyway all you want to know is @emph{why} that package
12045 actually depends on some seemingly unrelated package. The
12046 @option{--path} option instructs @command{guix graph} to display the
12047 shortest path between two packages (or derivations, or store items,
12051 $ guix graph --path emacs libunistring
12054 libunistring@@0.9.10
12055 $ guix graph --path -t derivation emacs libunistring
12056 /gnu/store/@dots{}-emacs-26.3.drv
12057 /gnu/store/@dots{}-mailutils-3.9.drv
12058 /gnu/store/@dots{}-libunistring-0.9.10.drv
12059 $ guix graph --path -t references emacs libunistring
12060 /gnu/store/@dots{}-emacs-26.3
12061 /gnu/store/@dots{}-libidn2-2.2.0
12062 /gnu/store/@dots{}-libunistring-0.9.10
12065 The available options are the following:
12068 @item --type=@var{type}
12069 @itemx -t @var{type}
12070 Produce a graph output of @var{type}, where @var{type} must be one of
12071 the values listed above.
12074 List the supported graph types.
12076 @item --backend=@var{backend}
12077 @itemx -b @var{backend}
12078 Produce a graph using the selected @var{backend}.
12080 @item --list-backends
12081 List the supported graph backends.
12083 Currently, the available backends are Graphviz and d3.js.
12086 Display the shortest path between two nodes of the type specified by
12087 @option{--type}. The example below shows the shortest path between
12088 @code{libreoffice} and @code{llvm} according to the references of
12089 @code{libreoffice}:
12092 $ guix graph --path -t references libreoffice llvm
12093 /gnu/store/@dots{}-libreoffice-6.4.2.2
12094 /gnu/store/@dots{}-libepoxy-1.5.4
12095 /gnu/store/@dots{}-mesa-19.3.4
12096 /gnu/store/@dots{}-llvm-9.0.1
12099 @item --expression=@var{expr}
12100 @itemx -e @var{expr}
12101 Consider the package @var{expr} evaluates to.
12103 This is useful to precisely refer to a package, as in this example:
12106 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
12109 @item --system=@var{system}
12110 @itemx -s @var{system}
12111 Display the graph for @var{system}---e.g., @code{i686-linux}.
12113 The package dependency graph is largely architecture-independent, but there
12114 are some architecture-dependent bits that this option allows you to visualize.
12116 @item --load-path=@var{directory}
12117 @itemx -L @var{directory}
12118 Add @var{directory} to the front of the package module search path
12119 (@pxref{Package Modules}).
12121 This allows users to define their own packages and make them visible to
12122 the command-line tools.
12125 On top of that, @command{guix graph} supports all the usual package
12126 transformation options (@pxref{Package Transformation Options}). This
12127 makes it easy to view the effect of a graph-rewriting transformation
12128 such as @option{--with-input}. For example, the command below outputs
12129 the graph of @code{git} once @code{openssl} has been replaced by
12130 @code{libressl} everywhere in the graph:
12133 guix graph git --with-input=openssl=libressl
12136 So many possibilities, so much fun!
12138 @node Invoking guix publish
12139 @section Invoking @command{guix publish}
12141 @cindex @command{guix publish}
12142 The purpose of @command{guix publish} is to enable users to easily share
12143 their store with others, who can then use it as a substitute server
12144 (@pxref{Substitutes}).
12146 When @command{guix publish} runs, it spawns an HTTP server which allows
12147 anyone with network access to obtain substitutes from it. This means
12148 that any machine running Guix can also act as if it were a build farm,
12149 since the HTTP interface is compatible with Cuirass, the software behind
12150 the @code{@value{SUBSTITUTE-SERVER}} build farm.
12152 For security, each substitute is signed, allowing recipients to check
12153 their authenticity and integrity (@pxref{Substitutes}). Because
12154 @command{guix publish} uses the signing key of the system, which is only
12155 readable by the system administrator, it must be started as root; the
12156 @option{--user} option makes it drop root privileges early on.
12158 The signing key pair must be generated before @command{guix publish} is
12159 launched, using @command{guix archive --generate-key} (@pxref{Invoking
12162 The general syntax is:
12165 guix publish @var{options}@dots{}
12168 Running @command{guix publish} without any additional arguments will
12169 spawn an HTTP server on port 8080:
12175 Once a publishing server has been authorized, the daemon may download
12176 substitutes from it. @xref{Getting Substitutes from Other Servers}.
12178 By default, @command{guix publish} compresses archives on the fly as it
12179 serves them. This ``on-the-fly'' mode is convenient in that it requires
12180 no setup and is immediately available. However, when serving lots of
12181 clients, we recommend using the @option{--cache} option, which enables
12182 caching of the archives before they are sent to clients---see below for
12183 details. The @command{guix weather} command provides a handy way to
12184 check what a server provides (@pxref{Invoking guix weather}).
12186 As a bonus, @command{guix publish} also serves as a content-addressed
12187 mirror for source files referenced in @code{origin} records
12188 (@pxref{origin Reference}). For instance, assuming @command{guix
12189 publish} is running on @code{example.org}, the following URL returns the
12190 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
12191 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
12194 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
12197 Obviously, these URLs only work for files that are in the store; in
12198 other cases, they return 404 (``Not Found'').
12200 @cindex build logs, publication
12201 Build logs are available from @code{/log} URLs like:
12204 http://example.org/log/gwspk@dots{}-guile-2.2.3
12208 When @command{guix-daemon} is configured to save compressed build logs,
12209 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
12210 URLs return the compressed log as-is, with an appropriate
12211 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
12212 running @command{guix-daemon} with @option{--log-compression=gzip} since
12213 Web browsers can automatically decompress it, which is not the case with
12216 The following options are available:
12219 @item --port=@var{port}
12220 @itemx -p @var{port}
12221 Listen for HTTP requests on @var{port}.
12223 @item --listen=@var{host}
12224 Listen on the network interface for @var{host}. The default is to
12225 accept connections from any interface.
12227 @item --user=@var{user}
12228 @itemx -u @var{user}
12229 Change privileges to @var{user} as soon as possible---i.e., once the
12230 server socket is open and the signing key has been read.
12232 @item --compression[=@var{method}[:@var{level}]]
12233 @itemx -C [@var{method}[:@var{level}]]
12234 Compress data using the given @var{method} and @var{level}. @var{method} is
12235 one of @code{lzip} and @code{gzip}; when @var{method} is omitted, @code{gzip}
12238 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
12239 to different compression levels: 1 is the fastest, and 9 is the best
12240 (CPU-intensive). The default is 3.
12242 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a small
12243 increase in CPU usage; see
12244 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip Web
12247 Unless @option{--cache} is used, compression occurs on the fly and
12248 the compressed streams are not
12249 cached. Thus, to reduce load on the machine that runs @command{guix
12250 publish}, it may be a good idea to choose a low compression level, to
12251 run @command{guix publish} behind a caching proxy, or to use
12252 @option{--cache}. Using @option{--cache} has the advantage that it
12253 allows @command{guix publish} to add @code{Content-Length} HTTP header
12256 This option can be repeated, in which case every substitute gets compressed
12257 using all the selected methods, and all of them are advertised. This is
12258 useful when users may not support all the compression methods: they can select
12259 the one they support.
12261 @item --cache=@var{directory}
12262 @itemx -c @var{directory}
12263 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
12264 and only serve archives that are in cache.
12266 When this option is omitted, archives and meta-data are created
12267 on-the-fly. This can reduce the available bandwidth, especially when
12268 compression is enabled, since this may become CPU-bound. Another
12269 drawback of the default mode is that the length of archives is not known
12270 in advance, so @command{guix publish} does not add a
12271 @code{Content-Length} HTTP header to its responses, which in turn
12272 prevents clients from knowing the amount of data being downloaded.
12274 Conversely, when @option{--cache} is used, the first request for a store
12275 item (@i{via} a @code{.narinfo} URL) triggers a
12276 background process to @dfn{bake} the archive---computing its
12277 @code{.narinfo} and compressing the archive, if needed. Once the
12278 archive is cached in @var{directory}, subsequent requests succeed and
12279 are served directly from the cache, which guarantees that clients get
12280 the best possible bandwidth.
12282 That first @code{.narinfo} request nonetheless returns 200, provided the
12283 requested store item is ``small enough'', below the cache bypass
12284 threshold---see @option{--cache-bypass-threshold} below. That way,
12285 clients do not have to wait until the archive is baked. For larger
12286 store items, the first @code{.narinfo} request returns 404, meaning that
12287 clients have to wait until the archive is baked.
12289 The ``baking'' process is performed by worker threads. By default, one
12290 thread per CPU core is created, but this can be customized. See
12291 @option{--workers} below.
12293 When @option{--ttl} is used, cached entries are automatically deleted
12294 when they have expired.
12296 @item --workers=@var{N}
12297 When @option{--cache} is used, request the allocation of @var{N} worker
12298 threads to ``bake'' archives.
12300 @item --ttl=@var{ttl}
12301 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
12302 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
12303 days, @code{1m} means 1 month, and so on.
12305 This allows the user's Guix to keep substitute information in cache for
12306 @var{ttl}. However, note that @code{guix publish} does not itself
12307 guarantee that the store items it provides will indeed remain available
12308 for as long as @var{ttl}.
12310 Additionally, when @option{--cache} is used, cached entries that have
12311 not been accessed for @var{ttl} and that no longer have a corresponding
12312 item in the store, may be deleted.
12314 @item --cache-bypass-threshold=@var{size}
12315 When used in conjunction with @option{--cache}, store items smaller than
12316 @var{size} are immediately available, even when they are not yet in
12317 cache. @var{size} is a size in bytes, or it can be suffixed by @code{M}
12318 for megabytes and so on. The default is @code{10M}.
12320 ``Cache bypass'' allows you to reduce the publication delay for clients
12321 at the expense of possibly additional I/O and CPU use on the server
12322 side: depending on the client access patterns, those store items can end
12323 up being baked several times until a copy is available in cache.
12325 Increasing the threshold may be useful for sites that have few users, or
12326 to guarantee that users get substitutes even for store items that are
12329 @item --nar-path=@var{path}
12330 Use @var{path} as the prefix for the URLs of ``nar'' files
12331 (@pxref{Invoking guix archive, normalized archives}).
12333 By default, nars are served at a URL such as
12334 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
12335 change the @code{/nar} part to @var{path}.
12337 @item --public-key=@var{file}
12338 @itemx --private-key=@var{file}
12339 Use the specific @var{file}s as the public/private key pair used to sign
12340 the store items being published.
12342 The files must correspond to the same key pair (the private key is used
12343 for signing and the public key is merely advertised in the signature
12344 metadata). They must contain keys in the canonical s-expression format
12345 as produced by @command{guix archive --generate-key} (@pxref{Invoking
12346 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
12347 @file{/etc/guix/signing-key.sec} are used.
12349 @item --repl[=@var{port}]
12350 @itemx -r [@var{port}]
12351 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
12352 Reference Manual}) on @var{port} (37146 by default). This is used
12353 primarily for debugging a running @command{guix publish} server.
12356 Enabling @command{guix publish} on Guix System is a one-liner: just
12357 instantiate a @code{guix-publish-service-type} service in the @code{services} field
12358 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
12359 @code{guix-publish-service-type}}).
12361 If you are instead running Guix on a ``foreign distro'', follow these
12366 If your host distro uses the systemd init system:
12369 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
12370 /etc/systemd/system/
12371 # systemctl start guix-publish && systemctl enable guix-publish
12375 If your host distro uses the Upstart init system:
12378 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
12379 # start guix-publish
12383 Otherwise, proceed similarly with your distro's init system.
12386 @node Invoking guix challenge
12387 @section Invoking @command{guix challenge}
12389 @cindex reproducible builds
12390 @cindex verifiable builds
12391 @cindex @command{guix challenge}
12393 Do the binaries provided by this server really correspond to the source
12394 code it claims to build? Is a package build process deterministic?
12395 These are the questions the @command{guix challenge} command attempts to
12398 The former is obviously an important question: Before using a substitute
12399 server (@pxref{Substitutes}), one had better @emph{verify} that it
12400 provides the right binaries, and thus @emph{challenge} it. The latter
12401 is what enables the former: If package builds are deterministic, then
12402 independent builds of the package should yield the exact same result,
12403 bit for bit; if a server provides a binary different from the one
12404 obtained locally, it may be either corrupt or malicious.
12406 We know that the hash that shows up in @file{/gnu/store} file names is
12407 the hash of all the inputs of the process that built the file or
12408 directory---compilers, libraries, build scripts,
12409 etc. (@pxref{Introduction}). Assuming deterministic build processes,
12410 one store file name should map to exactly one build output.
12411 @command{guix challenge} checks whether there is, indeed, a single
12412 mapping by comparing the build outputs of several independent builds of
12413 any given store item.
12415 The command output looks like this:
12418 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
12419 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
12420 updating list of substitutes from 'https://guix.example.org'... 100.0%
12421 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
12422 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
12423 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
12424 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
12426 /lib/libcrypto.so.1.1
12429 /gnu/store/@dots{}-git-2.5.0 contents differ:
12430 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
12431 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
12432 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
12434 /libexec/git-core/git-fsck
12436 /gnu/store/@dots{}-pius-2.1.1 contents differ:
12437 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
12438 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
12439 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
12441 /share/man/man1/pius.1.gz
12445 6,406 store items were analyzed:
12446 - 4,749 (74.1%) were identical
12447 - 525 (8.2%) differed
12448 - 1,132 (17.7%) were inconclusive
12452 In this example, @command{guix challenge} first scans the store to
12453 determine the set of locally-built derivations---as opposed to store
12454 items that were downloaded from a substitute server---and then queries
12455 all the substitute servers. It then reports those store items for which
12456 the servers obtained a result different from the local build.
12458 @cindex non-determinism, in package builds
12459 As an example, @code{guix.example.org} always gets a different answer.
12460 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
12461 case of Git. This might indicate that the build process of Git is
12462 non-deterministic, meaning that its output varies as a function of
12463 various things that Guix does not fully control, in spite of building
12464 packages in isolated environments (@pxref{Features}). Most common
12465 sources of non-determinism include the addition of timestamps in build
12466 results, the inclusion of random numbers, and directory listings sorted
12467 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
12470 To find out what is wrong with this Git binary, the easiest approach is
12474 guix challenge git \
12475 --diff=diffoscope \
12476 --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
12479 This automatically invokes @command{diffoscope}, which displays detailed
12480 information about files that differ.
12482 Alternatively, we can do something along these lines (@pxref{Invoking guix
12486 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-git-2.5.0 \
12487 | lzip -d | guix archive -x /tmp/git
12488 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
12491 This command shows the difference between the files resulting from the
12492 local build, and the files resulting from the build on
12493 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
12494 diffutils, Comparing and Merging Files}). The @command{diff} command
12495 works great for text files. When binary files differ, a better option
12496 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
12497 visualize differences for all kinds of files.
12499 Once you have done that work, you can tell whether the differences are due
12500 to a non-deterministic build process or to a malicious server. We try
12501 hard to remove sources of non-determinism in packages to make it easier
12502 to verify substitutes, but of course, this is a process that
12503 involves not just Guix, but a large part of the free software community.
12504 In the meantime, @command{guix challenge} is one tool to help address
12507 If you are writing packages for Guix, you are encouraged to check
12508 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
12509 same build result as you did with:
12512 $ guix challenge @var{package}
12516 where @var{package} is a package specification such as
12517 @code{guile@@2.0} or @code{glibc:debug}.
12519 The general syntax is:
12522 guix challenge @var{options} [@var{packages}@dots{}]
12525 When a difference is found between the hash of a locally-built item and
12526 that of a server-provided substitute, or among substitutes provided by
12527 different servers, the command displays it as in the example above and
12528 its exit code is 2 (other non-zero exit codes denote other kinds of
12531 The one option that matters is:
12535 @item --substitute-urls=@var{urls}
12536 Consider @var{urls} the whitespace-separated list of substitute source
12537 URLs to compare to.
12539 @item --diff=@var{mode}
12540 Upon mismatches, show differences according to @var{mode}, one of:
12543 @item @code{simple} (the default)
12544 Show the list of files that differ.
12546 @item @code{diffoscope}
12547 @itemx @var{command}
12548 Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
12549 two directories whose contents do not match.
12551 When @var{command} is an absolute file name, run @var{command} instead
12555 Do not show further details about the differences.
12558 Thus, unless @option{--diff=none} is passed, @command{guix challenge}
12559 downloads the store items from the given substitute servers so that it
12564 Show details about matches (identical contents) in addition to
12565 information about mismatches.
12569 @node Invoking guix copy
12570 @section Invoking @command{guix copy}
12572 @cindex copy, of store items, over SSH
12573 @cindex SSH, copy of store items
12574 @cindex sharing store items across machines
12575 @cindex transferring store items across machines
12576 The @command{guix copy} command copies items from the store of one
12577 machine to that of another machine over a secure shell (SSH)
12578 connection@footnote{This command is available only when Guile-SSH was
12579 found. @xref{Requirements}, for details.}. For example, the following
12580 command copies the @code{coreutils} package, the user's profile, and all
12581 their dependencies over to @var{host}, logged in as @var{user}:
12584 guix copy --to=@var{user}@@@var{host} \
12585 coreutils `readlink -f ~/.guix-profile`
12588 If some of the items to be copied are already present on @var{host},
12589 they are not actually sent.
12591 The command below retrieves @code{libreoffice} and @code{gimp} from
12592 @var{host}, assuming they are available there:
12595 guix copy --from=@var{host} libreoffice gimp
12598 The SSH connection is established using the Guile-SSH client, which is
12599 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
12600 @file{~/.ssh/config}, and uses the SSH agent for authentication.
12602 The key used to sign items that are sent must be accepted by the remote
12603 machine. Likewise, the key used by the remote machine to sign items you
12604 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
12605 own daemon. @xref{Invoking guix archive}, for more information about
12606 store item authentication.
12608 The general syntax is:
12611 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
12614 You must always specify one of the following options:
12617 @item --to=@var{spec}
12618 @itemx --from=@var{spec}
12619 Specify the host to send to or receive from. @var{spec} must be an SSH
12620 spec such as @code{example.org}, @code{charlie@@example.org}, or
12621 @code{charlie@@example.org:2222}.
12624 The @var{items} can be either package names, such as @code{gimp}, or
12625 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
12627 When specifying the name of a package to send, it is first built if
12628 needed, unless @option{--dry-run} was specified. Common build options
12629 are supported (@pxref{Common Build Options}).
12632 @node Invoking guix container
12633 @section Invoking @command{guix container}
12635 @cindex @command{guix container}
12637 As of version @value{VERSION}, this tool is experimental. The interface
12638 is subject to radical change in the future.
12641 The purpose of @command{guix container} is to manipulate processes
12642 running within an isolated environment, commonly known as a
12643 ``container'', typically created by the @command{guix environment}
12644 (@pxref{Invoking guix environment}) and @command{guix system container}
12645 (@pxref{Invoking guix system}) commands.
12647 The general syntax is:
12650 guix container @var{action} @var{options}@dots{}
12653 @var{action} specifies the operation to perform with a container, and
12654 @var{options} specifies the context-specific arguments for the action.
12656 The following actions are available:
12660 Execute a command within the context of a running container.
12665 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
12668 @var{pid} specifies the process ID of the running container.
12669 @var{program} specifies an executable file name within the root file
12670 system of the container. @var{arguments} are the additional options that
12671 will be passed to @var{program}.
12673 The following command launches an interactive login shell inside a
12674 Guix system container, started by @command{guix system container}, and whose
12675 process ID is 9001:
12678 guix container exec 9001 /run/current-system/profile/bin/bash --login
12681 Note that the @var{pid} cannot be the parent process of a container. It
12682 must be PID 1 of the container or one of its child processes.
12686 @node Invoking guix weather
12687 @section Invoking @command{guix weather}
12689 Occasionally you're grumpy because substitutes are lacking and you end
12690 up building packages by yourself (@pxref{Substitutes}). The
12691 @command{guix weather} command reports on substitute availability on the
12692 specified servers so you can have an idea of whether you'll be grumpy
12693 today. It can sometimes be useful info as a user, but it is primarily
12694 useful to people running @command{guix publish} (@pxref{Invoking guix
12697 @cindex statistics, for substitutes
12698 @cindex availability of substitutes
12699 @cindex substitute availability
12700 @cindex weather, substitute availability
12701 Here's a sample run:
12704 $ guix weather --substitute-urls=https://guix.example.org
12705 computing 5,872 package derivations for x86_64-linux...
12706 looking for 6,128 store items on https://guix.example.org..
12707 updating list of substitutes from 'https://guix.example.org'... 100.0%
12708 https://guix.example.org
12709 43.4% substitutes available (2,658 out of 6,128)
12710 7,032.5 MiB of nars (compressed)
12711 19,824.2 MiB on disk (uncompressed)
12712 0.030 seconds per request (182.9 seconds in total)
12713 33.5 requests per second
12715 9.8% (342 out of 3,470) of the missing items are queued
12717 x86_64-linux: 518 (59.7%)
12718 i686-linux: 221 (25.5%)
12719 aarch64-linux: 128 (14.8%)
12720 build rate: 23.41 builds per hour
12721 x86_64-linux: 11.16 builds per hour
12722 i686-linux: 6.03 builds per hour
12723 aarch64-linux: 6.41 builds per hour
12726 @cindex continuous integration, statistics
12727 As you can see, it reports the fraction of all the packages for which
12728 substitutes are available on the server---regardless of whether
12729 substitutes are enabled, and regardless of whether this server's signing
12730 key is authorized. It also reports the size of the compressed archives
12731 (``nars'') provided by the server, the size the corresponding store
12732 items occupy in the store (assuming deduplication is turned off), and
12733 the server's throughput. The second part gives continuous integration
12734 (CI) statistics, if the server supports it. In addition, using the
12735 @option{--coverage} option, @command{guix weather} can list ``important''
12736 package substitutes missing on the server (see below).
12738 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
12739 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
12740 challenge}, it ignores signatures on those substitutes, which is
12741 innocuous since the command only gathers statistics and cannot install
12744 The general syntax is:
12747 guix weather @var{options}@dots{} [@var{packages}@dots{}]
12750 When @var{packages} is omitted, @command{guix weather} checks the availability
12751 of substitutes for @emph{all} the packages, or for those specified with
12752 @option{--manifest}; otherwise it only considers the specified packages. It
12753 is also possible to query specific system types with @option{--system}.
12754 @command{guix weather} exits with a non-zero code when the fraction of
12755 available substitutes is below 100%.
12757 The available options are listed below.
12760 @item --substitute-urls=@var{urls}
12761 @var{urls} is the space-separated list of substitute server URLs to
12762 query. When this option is omitted, the default set of substitute
12763 servers is queried.
12765 @item --system=@var{system}
12766 @itemx -s @var{system}
12767 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
12768 option can be repeated, in which case @command{guix weather} will query
12769 substitutes for several system types.
12771 @item --manifest=@var{file}
12772 Instead of querying substitutes for all the packages, only ask for those
12773 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
12774 with the @code{-m} option of @command{guix package} (@pxref{Invoking
12777 This option can be repeated several times, in which case the manifests
12780 @item --coverage[=@var{count}]
12781 @itemx -c [@var{count}]
12782 Report on substitute coverage for packages: list packages with at least
12783 @var{count} dependents (zero by default) for which substitutes are
12784 unavailable. Dependent packages themselves are not listed: if @var{b} depends
12785 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
12786 @var{b} usually lacks substitutes as well. The result looks like this:
12789 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
12790 computing 8,983 package derivations for x86_64-linux...
12791 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
12792 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
12793 @value{SUBSTITUTE-URL}
12794 64.7% substitutes available (6,047 out of 9,343)
12796 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
12797 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
12798 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
12799 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
12803 What this example shows is that @code{kcoreaddons} and presumably the 58
12804 packages that depend on it have no substitutes at @code{ci.guix.info};
12805 likewise for @code{qgpgme} and the 46 packages that depend on it.
12807 If you are a Guix developer, or if you are taking care of this build farm,
12808 you'll probably want to have a closer look at these packages: they may simply
12811 @item --display-missing
12812 Display the list of store items for which substitutes are missing.
12815 @node Invoking guix processes
12816 @section Invoking @command{guix processes}
12818 The @command{guix processes} command can be useful to developers and system
12819 administrators, especially on multi-user machines and on build farms: it lists
12820 the current sessions (connections to the daemon), as well as information about
12821 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
12822 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
12823 listed.}. Here's an example of the information it returns:
12826 $ sudo guix processes
12829 ClientCommand: guix environment --ad-hoc python
12833 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
12837 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
12838 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
12839 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
12840 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
12841 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
12842 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
12843 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
12846 In this example we see that @command{guix-daemon} has three clients:
12847 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
12848 integration tool; their process identifier (PID) is given by the
12849 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
12850 @command{guix-daemon} sub-process of this particular session.
12852 The @code{LockHeld} fields show which store items are currently locked by this
12853 session, which corresponds to store items being built or substituted (the
12854 @code{LockHeld} field is not displayed when @command{guix processes} is not
12855 running as root). Last, by looking at the @code{ChildProcess} field, we
12856 understand that these three builds are being offloaded (@pxref{Daemon Offload
12859 The output is in Recutils format so we can use the handy @command{recsel}
12860 command to select sessions of interest (@pxref{Selection Expressions,,,
12861 recutils, GNU recutils manual}). As an example, the command shows the command
12862 line and PID of the client that triggered the build of a Perl package:
12865 $ sudo guix processes | \
12866 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
12868 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
12871 @node System Configuration
12872 @chapter System Configuration
12874 @cindex system configuration
12875 Guix System supports a consistent whole-system configuration
12876 mechanism. By that we mean that all aspects of the global system
12877 configuration---such as the available system services, timezone and
12878 locale settings, user accounts---are declared in a single place. Such
12879 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
12881 One of the advantages of putting all the system configuration under the
12882 control of Guix is that it supports transactional system upgrades, and
12883 makes it possible to roll back to a previous system instantiation,
12884 should something go wrong with the new one (@pxref{Features}). Another
12885 advantage is that it makes it easy to replicate the exact same configuration
12886 across different machines, or at different points in time, without
12887 having to resort to additional administration tools layered on top of
12888 the own tools of the system.
12889 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
12891 This section describes this mechanism. First we focus on the system
12892 administrator's viewpoint---explaining how the system is configured and
12893 instantiated. Then we show how this mechanism can be extended, for
12894 instance to support new system services.
12897 * Using the Configuration System:: Customizing your GNU system.
12898 * operating-system Reference:: Detail of operating-system declarations.
12899 * File Systems:: Configuring file system mounts.
12900 * Mapped Devices:: Block device extra processing.
12901 * User Accounts:: Specifying user accounts.
12902 * Keyboard Layout:: How the system interprets key strokes.
12903 * Locales:: Language and cultural convention settings.
12904 * Services:: Specifying system services.
12905 * Setuid Programs:: Programs running with root privileges.
12906 * X.509 Certificates:: Authenticating HTTPS servers.
12907 * Name Service Switch:: Configuring libc's name service switch.
12908 * Initial RAM Disk:: Linux-Libre bootstrapping.
12909 * Bootloader Configuration:: Configuring the boot loader.
12910 * Invoking guix system:: Instantiating a system configuration.
12911 * Invoking guix deploy:: Deploying a system configuration to a remote host.
12912 * Running Guix in a VM:: How to run Guix System in a virtual machine.
12913 * Defining Services:: Adding new service definitions.
12916 @node Using the Configuration System
12917 @section Using the Configuration System
12919 The operating system is configured by providing an
12920 @code{operating-system} declaration in a file that can then be passed to
12921 the @command{guix system} command (@pxref{Invoking guix system}). A
12922 simple setup, with the default system services, the default Linux-Libre
12923 kernel, initial RAM disk, and boot loader looks like this:
12925 @findex operating-system
12927 @include os-config-bare-bones.texi
12930 This example should be self-describing. Some of the fields defined
12931 above, such as @code{host-name} and @code{bootloader}, are mandatory.
12932 Others, such as @code{packages} and @code{services}, can be omitted, in
12933 which case they get a default value.
12935 Below we discuss the effect of some of the most important fields
12936 (@pxref{operating-system Reference}, for details about all the available
12937 fields), and how to @dfn{instantiate} the operating system using
12938 @command{guix system}.
12940 @unnumberedsubsec Bootloader
12942 @cindex legacy boot, on Intel machines
12943 @cindex BIOS boot, on Intel machines
12946 The @code{bootloader} field describes the method that will be used to boot
12947 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
12948 mode, as in the example above. However, more recent machines rely instead on
12949 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
12950 the @code{bootloader} field should contain something along these lines:
12953 (bootloader-configuration
12954 (bootloader grub-efi-bootloader)
12955 (target "/boot/efi"))
12958 @xref{Bootloader Configuration}, for more information on the available
12959 configuration options.
12961 @unnumberedsubsec Globally-Visible Packages
12963 @vindex %base-packages
12964 The @code{packages} field lists packages that will be globally visible
12965 on the system, for all user accounts---i.e., in every user's @env{PATH}
12966 environment variable---in addition to the per-user profiles
12967 (@pxref{Invoking guix package}). The @code{%base-packages} variable
12968 provides all the tools one would expect for basic user and administrator
12969 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
12970 the GNU Zile lightweight text editor, @command{find}, @command{grep},
12971 etc. The example above adds GNU@tie{}Screen to those,
12972 taken from the @code{(gnu packages screen)}
12973 module (@pxref{Package Modules}). The
12974 @code{(list package output)} syntax can be used to add a specific output
12978 (use-modules (gnu packages))
12979 (use-modules (gnu packages dns))
12983 (packages (cons (list bind "utils")
12987 @findex specification->package
12988 Referring to packages by variable name, like @code{bind} above, has
12989 the advantage of being unambiguous; it also allows typos and such to be
12990 diagnosed right away as ``unbound variables''. The downside is that one
12991 needs to know which module defines which package, and to augment the
12992 @code{use-package-modules} line accordingly. To avoid that, one can use
12993 the @code{specification->package} procedure of the @code{(gnu packages)}
12994 module, which returns the best package for a given name or name and
12998 (use-modules (gnu packages))
13002 (packages (append (map specification->package
13003 '("tcpdump" "htop" "gnupg@@2.0"))
13007 @unnumberedsubsec System Services
13010 @vindex %base-services
13011 The @code{services} field lists @dfn{system services} to be made
13012 available when the system starts (@pxref{Services}).
13013 The @code{operating-system} declaration above specifies that, in
13014 addition to the basic services, we want the OpenSSH secure shell
13015 daemon listening on port 2222 (@pxref{Networking Services,
13016 @code{openssh-service-type}}). Under the hood,
13017 @code{openssh-service-type} arranges so that @command{sshd} is started with the
13018 right command-line options, possibly with supporting configuration files
13019 generated as needed (@pxref{Defining Services}).
13021 @cindex customization, of services
13022 @findex modify-services
13023 Occasionally, instead of using the base services as is, you will want to
13024 customize them. To do this, use @code{modify-services} (@pxref{Service
13025 Reference, @code{modify-services}}) to modify the list.
13027 For example, suppose you want to modify @code{guix-daemon} and Mingetty
13028 (the console log-in) in the @code{%base-services} list (@pxref{Base
13029 Services, @code{%base-services}}). To do that, you can write the
13030 following in your operating system declaration:
13033 (define %my-services
13034 ;; My very own list of services.
13035 (modify-services %base-services
13036 (guix-service-type config =>
13037 (guix-configuration
13039 ;; Fetch substitutes from example.org.
13041 (list "https://example.org/guix"
13042 "https://ci.guix.gnu.org"))))
13043 (mingetty-service-type config =>
13044 (mingetty-configuration
13046 ;; Automatially log in as "guest".
13047 (auto-login "guest")))))
13051 (services %my-services))
13054 This changes the configuration---i.e., the service parameters---of the
13055 @code{guix-service-type} instance, and that of all the
13056 @code{mingetty-service-type} instances in the @code{%base-services} list.
13057 Observe how this is accomplished: first, we arrange for the original
13058 configuration to be bound to the identifier @code{config} in the
13059 @var{body}, and then we write the @var{body} so that it evaluates to the
13060 desired configuration. In particular, notice how we use @code{inherit}
13061 to create a new configuration which has the same values as the old
13062 configuration, but with a few modifications.
13064 @cindex encrypted disk
13065 The configuration for a typical ``desktop'' usage, with an encrypted
13066 root partition, the X11 display
13067 server, GNOME and Xfce (users can choose which of these desktop
13068 environments to use at the log-in screen by pressing @kbd{F1}), network
13069 management, power management, and more, would look like this:
13072 @include os-config-desktop.texi
13075 A graphical system with a choice of lightweight window managers
13076 instead of full-blown desktop environments would look like this:
13079 @include os-config-lightweight-desktop.texi
13082 This example refers to the @file{/boot/efi} file system by its UUID,
13083 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
13084 as returned by the @command{blkid} command.
13086 @xref{Desktop Services}, for the exact list of services provided by
13087 @code{%desktop-services}. @xref{X.509 Certificates}, for background
13088 information about the @code{nss-certs} package that is used here.
13090 Again, @code{%desktop-services} is just a list of service objects. If
13091 you want to remove services from there, you can do so using the
13092 procedures for list filtering (@pxref{SRFI-1 Filtering and
13093 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
13094 following expression returns a list that contains all the services in
13095 @code{%desktop-services} minus the Avahi service:
13098 (remove (lambda (service)
13099 (eq? (service-kind service) avahi-service-type))
13103 @unnumberedsubsec Instantiating the System
13105 Assuming the @code{operating-system} declaration
13106 is stored in the @file{my-system-config.scm}
13107 file, the @command{guix system reconfigure my-system-config.scm} command
13108 instantiates that configuration, and makes it the default GRUB boot
13109 entry (@pxref{Invoking guix system}).
13111 The normal way to change the system configuration is by updating this
13112 file and re-running @command{guix system reconfigure}. One should never
13113 have to touch files in @file{/etc} or to run commands that modify the
13114 system state such as @command{useradd} or @command{grub-install}. In
13115 fact, you must avoid that since that would not only void your warranty
13116 but also prevent you from rolling back to previous versions of your
13117 system, should you ever need to.
13119 @cindex roll-back, of the operating system
13120 Speaking of roll-back, each time you run @command{guix system
13121 reconfigure}, a new @dfn{generation} of the system is created---without
13122 modifying or deleting previous generations. Old system generations get
13123 an entry in the bootloader boot menu, allowing you to boot them in case
13124 something went wrong with the latest generation. Reassuring, no? The
13125 @command{guix system list-generations} command lists the system
13126 generations available on disk. It is also possible to roll back the
13127 system via the commands @command{guix system roll-back} and
13128 @command{guix system switch-generation}.
13130 Although the @command{guix system reconfigure} command will not modify
13131 previous generations, you must take care when the current generation is not
13132 the latest (e.g., after invoking @command{guix system roll-back}), since
13133 the operation might overwrite a later generation (@pxref{Invoking guix
13136 @unnumberedsubsec The Programming Interface
13138 At the Scheme level, the bulk of an @code{operating-system} declaration
13139 is instantiated with the following monadic procedure (@pxref{The Store
13142 @deffn {Monadic Procedure} operating-system-derivation os
13143 Return a derivation that builds @var{os}, an @code{operating-system}
13144 object (@pxref{Derivations}).
13146 The output of the derivation is a single directory that refers to all
13147 the packages, configuration files, and other supporting files needed to
13148 instantiate @var{os}.
13151 This procedure is provided by the @code{(gnu system)} module. Along
13152 with @code{(gnu services)} (@pxref{Services}), this module contains the
13153 guts of Guix System. Make sure to visit it!
13156 @node operating-system Reference
13157 @section @code{operating-system} Reference
13159 This section summarizes all the options available in
13160 @code{operating-system} declarations (@pxref{Using the Configuration
13163 @deftp {Data Type} operating-system
13164 This is the data type representing an operating system configuration.
13165 By that, we mean all the global system configuration, not per-user
13166 configuration (@pxref{Using the Configuration System}).
13169 @item @code{kernel} (default: @code{linux-libre})
13170 The package object of the operating system kernel to
13171 use@footnote{Currently only the Linux-libre kernel is fully supported.
13172 Using GNU@tie{}mach with the GNU@tie{}Hurd is experimental and only
13173 available when building a virtual machine disk image.}.
13176 @item @code{hurd} (default: @code{#f})
13177 The package object of the Hurd to be started by the kernel. When this
13178 field is set, produce a GNU/Hurd operating system. In that case,
13179 @code{kernel} must also be set to the @code{gnumach} package---the
13180 microkernel the Hurd runs on.
13183 This feature is experimental and only supported for disk images.
13186 @item @code{kernel-loadable-modules} (default: '())
13187 A list of objects (usually packages) to collect loadable kernel modules
13188 from--e.g. @code{(list ddcci-driver-linux)}.
13190 @item @code{kernel-arguments} (default: @code{%default-kernel-arguments})
13191 List of strings or gexps representing additional arguments to pass on
13192 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
13194 @item @code{bootloader}
13195 The system bootloader configuration object. @xref{Bootloader Configuration}.
13198 This is the label (a string) as it appears in the bootloader's menu entry.
13199 The default label includes the kernel name and version.
13201 @item @code{keyboard-layout} (default: @code{#f})
13202 This field specifies the keyboard layout to use in the console. It can be
13203 either @code{#f}, in which case the default keyboard layout is used (usually
13204 US English), or a @code{<keyboard-layout>} record.
13206 This keyboard layout is in effect as soon as the kernel has booted. For
13207 instance, it is the keyboard layout in effect when you type a passphrase if
13208 your root file system is on a @code{luks-device-mapping} mapped device
13209 (@pxref{Mapped Devices}).
13212 This does @emph{not} specify the keyboard layout used by the bootloader, nor
13213 that used by the graphical display server. @xref{Bootloader Configuration},
13214 for information on how to specify the bootloader's keyboard layout. @xref{X
13215 Window}, for information on how to specify the keyboard layout used by the X
13219 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
13221 @cindex initial RAM disk
13222 The list of Linux kernel modules that need to be available in the
13223 initial RAM disk. @xref{Initial RAM Disk}.
13225 @item @code{initrd} (default: @code{base-initrd})
13226 A procedure that returns an initial RAM disk for the Linux
13227 kernel. This field is provided to support low-level customization and
13228 should rarely be needed for casual use. @xref{Initial RAM Disk}.
13230 @item @code{firmware} (default: @code{%base-firmware})
13232 List of firmware packages loadable by the operating system kernel.
13234 The default includes firmware needed for Atheros- and Broadcom-based
13235 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
13236 respectively). @xref{Hardware Considerations}, for more info on
13237 supported hardware.
13239 @item @code{host-name}
13242 @item @code{hosts-file}
13244 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
13245 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
13246 Reference Manual}). The default is a file with entries for
13247 @code{localhost} and @var{host-name}.
13249 @item @code{mapped-devices} (default: @code{'()})
13250 A list of mapped devices. @xref{Mapped Devices}.
13252 @item @code{file-systems}
13253 A list of file systems. @xref{File Systems}.
13255 @cindex swap devices
13257 @item @code{swap-devices} (default: @code{'()})
13258 A list of UUIDs, file system labels, or strings identifying devices or
13259 files to be used for ``swap
13260 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
13261 Manual}). Here are some examples:
13264 @item (list (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb"))
13265 Use the swap partition with the given UUID. You can learn the UUID of a
13266 Linux swap partition by running @command{swaplabel @var{device}}, where
13267 @var{device} is the @file{/dev} file name of that partition.
13269 @item (list (file-system-label "swap"))
13270 Use the partition with label @code{swap}. Again, the
13271 @command{swaplabel} command allows you to view and change the label of a
13272 Linux swap partition.
13274 @item (list "/swapfile")
13275 Use the file @file{/swapfile} as swap space.
13277 @item (list "/dev/sda3" "/dev/sdb2")
13278 Use the @file{/dev/sda3} and @file{/dev/sdb2} partitions as swap space.
13279 We recommend referring to swap devices by UUIDs or labels as shown above
13283 It is possible to specify a swap file in a file system on a mapped
13284 device (under @file{/dev/mapper}), provided that the necessary device
13285 mapping and file system are also specified. @xref{Mapped Devices} and
13286 @ref{File Systems}.
13288 @item @code{users} (default: @code{%base-user-accounts})
13289 @itemx @code{groups} (default: @code{%base-groups})
13290 List of user accounts and groups. @xref{User Accounts}.
13292 If the @code{users} list lacks a user account with UID@tie{}0, a
13293 ``root'' account with UID@tie{}0 is automatically added.
13295 @item @code{skeletons} (default: @code{(default-skeletons)})
13296 A list of target file name/file-like object tuples (@pxref{G-Expressions,
13297 file-like objects}). These are the skeleton files that will be added to
13298 the home directory of newly-created user accounts.
13300 For instance, a valid value may look like this:
13303 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
13304 (".guile" ,(plain-file "guile"
13305 "(use-modules (ice-9 readline))
13306 (activate-readline)")))
13309 @item @code{issue} (default: @code{%default-issue})
13310 A string denoting the contents of the @file{/etc/issue} file, which is
13311 displayed when users log in on a text console.
13313 @item @code{packages} (default: @code{%base-packages})
13314 A list of packages to be installed in the global profile, which is accessible
13315 at @file{/run/current-system/profile}. Each element is either a package
13316 variable or a package/output tuple. Here's a simple example of both:
13319 (cons* git ; the default "out" output
13320 (list git "send-email") ; another output of git
13321 %base-packages) ; the default set
13324 The default set includes core utilities and it is good practice to
13325 install non-core utilities in user profiles (@pxref{Invoking guix
13328 @item @code{timezone}
13329 A timezone identifying string---e.g., @code{"Europe/Paris"}.
13331 You can run the @command{tzselect} command to find out which timezone
13332 string corresponds to your region. Choosing an invalid timezone name
13333 causes @command{guix system} to fail.
13335 @item @code{locale} (default: @code{"en_US.utf8"})
13336 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
13337 Library Reference Manual}). @xref{Locales}, for more information.
13339 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
13340 The list of locale definitions to be compiled and that may be used at
13341 run time. @xref{Locales}.
13343 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
13344 The list of GNU@tie{}libc packages whose locale data and tools are used
13345 to build the locale definitions. @xref{Locales}, for compatibility
13346 considerations that justify this option.
13348 @item @code{name-service-switch} (default: @code{%default-nss})
13349 Configuration of the libc name service switch (NSS)---a
13350 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
13353 @item @code{services} (default: @code{%base-services})
13354 A list of service objects denoting system services. @xref{Services}.
13356 @cindex essential services
13357 @item @code{essential-services} (default: ...)
13358 The list of ``essential services''---i.e., things like instances of
13359 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
13360 Reference}), which are derived from the operating system definition itself.
13361 As a user you should @emph{never} need to touch this field.
13363 @item @code{pam-services} (default: @code{(base-pam-services)})
13365 @cindex pluggable authentication modules
13366 Linux @dfn{pluggable authentication module} (PAM) services.
13367 @c FIXME: Add xref to PAM services section.
13369 @item @code{setuid-programs} (default: @code{%setuid-programs})
13370 List of string-valued G-expressions denoting setuid programs.
13371 @xref{Setuid Programs}.
13373 @item @code{sudoers-file} (default: @code{%sudoers-specification})
13374 @cindex sudoers file
13375 The contents of the @file{/etc/sudoers} file as a file-like object
13376 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
13378 This file specifies which users can use the @command{sudo} command, what
13379 they are allowed to do, and what privileges they may gain. The default
13380 is that only @code{root} and members of the @code{wheel} group may use
13385 @deffn {Scheme Syntax} this-operating-system
13386 When used in the @emph{lexical scope} of an operating system field definition,
13387 this identifier resolves to the operating system being defined.
13389 The example below shows how to refer to the operating system being defined in
13390 the definition of the @code{label} field:
13393 (use-modules (gnu) (guix))
13397 (label (package-full-name
13398 (operating-system-kernel this-operating-system))))
13401 It is an error to refer to @code{this-operating-system} outside an operating
13408 @section File Systems
13410 The list of file systems to be mounted is specified in the
13411 @code{file-systems} field of the operating system declaration
13412 (@pxref{Using the Configuration System}). Each file system is declared
13413 using the @code{file-system} form, like this:
13417 (mount-point "/home")
13418 (device "/dev/sda3")
13422 As usual, some of the fields are mandatory---those shown in the example
13423 above---while others can be omitted. These are described below.
13425 @deftp {Data Type} file-system
13426 Objects of this type represent file systems to be mounted. They
13427 contain the following members:
13431 This is a string specifying the type of the file system---e.g.,
13434 @item @code{mount-point}
13435 This designates the place where the file system is to be mounted.
13437 @item @code{device}
13438 This names the ``source'' of the file system. It can be one of three
13439 things: a file system label, a file system UUID, or the name of a
13440 @file{/dev} node. Labels and UUIDs offer a way to refer to file
13441 systems without having to hard-code their actual device
13442 name@footnote{Note that, while it is tempting to use
13443 @file{/dev/disk/by-uuid} and similar device names to achieve the same
13444 result, this is not recommended: These special device nodes are created
13445 by the udev daemon and may be unavailable at the time the device is
13448 @findex file-system-label
13449 File system labels are created using the @code{file-system-label}
13450 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
13451 plain strings. Here's an example of a file system referred to by its
13452 label, as shown by the @command{e2label} command:
13456 (mount-point "/home")
13458 (device (file-system-label "my-home")))
13462 UUIDs are converted from their string representation (as shown by the
13463 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
13464 @code{uuid} form expects 16-byte UUIDs as defined in
13465 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
13466 form of UUID used by the ext2 family of file systems and others, but it
13467 is different from ``UUIDs'' found in FAT file systems, for instance.},
13472 (mount-point "/home")
13474 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
13477 When the source of a file system is a mapped device (@pxref{Mapped
13478 Devices}), its @code{device} field @emph{must} refer to the mapped
13479 device name---e.g., @file{"/dev/mapper/root-partition"}.
13480 This is required so that
13481 the system knows that mounting the file system depends on having the
13482 corresponding device mapping established.
13484 @item @code{flags} (default: @code{'()})
13485 This is a list of symbols denoting mount flags. Recognized flags
13486 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
13487 access to special files), @code{no-suid} (ignore setuid and setgid
13488 bits), @code{no-atime} (do not update file access times),
13489 @code{strict-atime} (update file access time), @code{lazy-time} (only
13490 update time on the in-memory version of the file inode), and
13491 @code{no-exec} (disallow program execution).
13492 @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
13493 Manual}, for more information on these flags.
13495 @item @code{options} (default: @code{#f})
13496 This is either @code{#f}, or a string denoting mount options passed to
13497 the file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C
13498 Library Reference Manual}, for details and run @command{man 8 mount} for
13499 options for various file systems. Note that the
13500 @code{file-system-options->alist} and @code{alist->file-system-options}
13501 procedures from @code{(gnu system file-systems)} can be used to convert
13502 file system options given as an association list to the string
13503 representation, and vice-versa.
13505 @item @code{mount?} (default: @code{#t})
13506 This value indicates whether to automatically mount the file system when
13507 the system is brought up. When set to @code{#f}, the file system gets
13508 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
13509 is not automatically mounted.
13511 @item @code{needed-for-boot?} (default: @code{#f})
13512 This Boolean value indicates whether the file system is needed when
13513 booting. If that is true, then the file system is mounted when the
13514 initial RAM disk (initrd) is loaded. This is always the case, for
13515 instance, for the root file system.
13517 @item @code{check?} (default: @code{#t})
13518 This Boolean indicates whether the file system needs to be checked for
13519 errors before being mounted.
13521 @item @code{create-mount-point?} (default: @code{#f})
13522 When true, the mount point is created if it does not exist yet.
13524 @item @code{mount-may-fail?} (default: @code{#f})
13525 When true, this indicates that mounting this file system can fail but
13526 that should not be considered an error. This is useful in unusual
13527 cases; an example of this is @code{efivarfs}, a file system that can
13528 only be mounted on EFI/UEFI systems.
13530 @item @code{dependencies} (default: @code{'()})
13531 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
13532 representing file systems that must be mounted or mapped devices that
13533 must be opened before (and unmounted or closed after) this one.
13535 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
13536 a dependency of @file{/sys/fs/cgroup/cpu} and
13537 @file{/sys/fs/cgroup/memory}.
13539 Another example is a file system that depends on a mapped device, for
13540 example for an encrypted partition (@pxref{Mapped Devices}).
13544 @deffn {Scheme Procedure} file-system-label @var{str}
13545 This procedure returns an opaque file system label from @var{str}, a
13549 (file-system-label "home")
13550 @result{} #<file-system-label "home">
13553 File system labels are used to refer to file systems by label rather
13554 than by device name. See above for examples.
13557 The @code{(gnu system file-systems)} exports the following useful
13560 @defvr {Scheme Variable} %base-file-systems
13561 These are essential file systems that are required on normal systems,
13562 such as @code{%pseudo-terminal-file-system} and @code{%immutable-store} (see
13563 below). Operating system declarations should always contain at least
13567 @defvr {Scheme Variable} %pseudo-terminal-file-system
13568 This is the file system to be mounted as @file{/dev/pts}. It supports
13569 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
13570 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
13571 Manual}). Pseudo-terminals are used by terminal emulators such as
13575 @defvr {Scheme Variable} %shared-memory-file-system
13576 This file system is mounted as @file{/dev/shm} and is used to support
13577 memory sharing across processes (@pxref{Memory-mapped I/O,
13578 @code{shm_open},, libc, The GNU C Library Reference Manual}).
13581 @defvr {Scheme Variable} %immutable-store
13582 This file system performs a read-only ``bind mount'' of
13583 @file{/gnu/store}, making it read-only for all the users including
13584 @code{root}. This prevents against accidental modification by software
13585 running as @code{root} or by system administrators.
13587 The daemon itself is still able to write to the store: it remounts it
13588 read-write in its own ``name space.''
13591 @defvr {Scheme Variable} %binary-format-file-system
13592 The @code{binfmt_misc} file system, which allows handling of arbitrary
13593 executable file types to be delegated to user space. This requires the
13594 @code{binfmt.ko} kernel module to be loaded.
13597 @defvr {Scheme Variable} %fuse-control-file-system
13598 The @code{fusectl} file system, which allows unprivileged users to mount
13599 and unmount user-space FUSE file systems. This requires the
13600 @code{fuse.ko} kernel module to be loaded.
13603 The @code{(gnu system uuid)} module provides tools to deal with file
13604 system ``unique identifiers'' (UUIDs).
13606 @deffn {Scheme Procedure} uuid @var{str} [@var{type}]
13607 Return an opaque UUID (unique identifier) object of the given @var{type}
13608 (a symbol) by parsing @var{str} (a string):
13611 (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")
13612 @result{} #<<uuid> type: dce bv: @dots{}>
13614 (uuid "1234-ABCD" 'fat)
13615 @result{} #<<uuid> type: fat bv: @dots{}>
13618 @var{type} may be one of @code{dce}, @code{iso9660}, @code{fat},
13619 @code{ntfs}, or one of the commonly found synonyms for these.
13621 UUIDs are another way to unambiguously refer to file systems in
13622 operating system configuration. See the examples above.
13626 @node Btrfs file system
13627 @subsection Btrfs file system
13629 The Btrfs has special features, such as subvolumes, that merit being
13630 explained in more details. The following section attempts to cover
13631 basic as well as complex uses of a Btrfs file system with the Guix
13634 In its simplest usage, a Btrfs file system can be described, for
13639 (mount-point "/home")
13641 (device (file-system-label "my-home")))
13644 The example below is more complex, as it makes use of a Btrfs
13645 subvolume, named @code{rootfs}. The parent Btrfs file system is labeled
13646 @code{my-btrfs-pool}, and is located on an encrypted device (hence the
13647 dependency on @code{mapped-devices}):
13651 (device (file-system-label "my-btrfs-pool"))
13654 (options "subvol=rootfs")
13655 (dependencies mapped-devices))
13658 Some bootloaders, for example GRUB, only mount a Btrfs partition at its
13659 top level during the early boot, and rely on their configuration to
13660 refer to the correct subvolume path within that top level. The
13661 bootloaders operating in this way typically produce their configuration
13662 on a running system where the Btrfs partitions are already mounted and
13663 where the subvolume information is readily available. As an example,
13664 @command{grub-mkconfig}, the configuration generator command shipped
13665 with GRUB, reads @file{/proc/self/mountinfo} to determine the top-level
13666 path of a subvolume.
13668 The Guix System produces a bootloader configuration using the operating
13669 system configuration as its sole input; it is therefore necessary to
13670 extract the subvolume name on which @file{/gnu/store} lives (if any)
13671 from that operating system configuration. To better illustrate,
13672 consider a subvolume named 'rootfs' which contains the root file system
13673 data. In such situation, the GRUB bootloader would only see the top
13674 level of the root Btrfs partition, e.g.:
13678 ├── rootfs (subvolume directory)
13679 ├── gnu (normal directory)
13680 ├── store (normal directory)
13684 Thus, the subvolume name must be prepended to the @file{/gnu/store} path
13685 of the kernel, initrd binaries and any other files referred to in the
13686 GRUB configuration that must be found during the early boot.
13688 The next example shows a nested hierarchy of subvolumes and
13693 ├── rootfs (subvolume)
13694 ├── gnu (normal directory)
13695 ├── store (subvolume)
13699 This scenario would work without mounting the 'store' subvolume.
13700 Mounting 'rootfs' is sufficient, since the subvolume name matches its
13701 intended mount point in the file system hierarchy. Alternatively, the
13702 'store' subvolume could be referred to by setting the @code{subvol}
13703 option to either @code{/rootfs/gnu/store} or @code{rootfs/gnu/store}.
13705 Finally, a more contrived example of nested subvolumes:
13709 ├── root-snapshots (subvolume)
13710 ├── root-current (subvolume)
13711 ├── guix-store (subvolume)
13715 Here, the 'guix-store' subvolume doesn't match its intended mount point,
13716 so it is necessary to mount it. The subvolume must be fully specified,
13717 by passing its file name to the @code{subvol} option. To illustrate,
13718 the 'guix-store' subvolume could be mounted on @file{/gnu/store} by using
13719 a file system declaration such as:
13723 (device (file-system-label "btrfs-pool-1"))
13724 (mount-point "/gnu/store")
13726 (options "subvol=root-snapshots/root-current/guix-store,\
13727 compress-force=zstd,space_cache=v2"))
13730 @node Mapped Devices
13731 @section Mapped Devices
13733 @cindex device mapping
13734 @cindex mapped devices
13735 The Linux kernel has a notion of @dfn{device mapping}: a block device,
13736 such as a hard disk partition, can be @dfn{mapped} into another device,
13737 usually in @code{/dev/mapper/},
13738 with additional processing over the data that flows through
13739 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
13740 concept of a ``mapped device'' and that of a file system: both boil down
13741 to @emph{translating} input/output operations made on a file to
13742 operations on its backing store. Thus, the Hurd implements mapped
13743 devices, like file systems, using the generic @dfn{translator} mechanism
13744 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
13745 typical example is encryption device mapping: all writes to the mapped
13746 device are encrypted, and all reads are deciphered, transparently.
13747 Guix extends this notion by considering any device or set of devices that
13748 are @dfn{transformed} in some way to create a new device; for instance,
13749 RAID devices are obtained by @dfn{assembling} several other devices, such
13750 as hard disks or partitions, into a new one that behaves as one partition.
13752 Mapped devices are declared using the @code{mapped-device} form,
13753 defined as follows; for examples, see below.
13755 @deftp {Data Type} mapped-device
13756 Objects of this type represent device mappings that will be made when
13757 the system boots up.
13761 This is either a string specifying the name of the block device to be mapped,
13762 such as @code{"/dev/sda3"}, or a list of such strings when several devices
13763 need to be assembled for creating a new one. In case of LVM this is a
13764 string specifying name of the volume group to be mapped.
13767 This string specifies the name of the resulting mapped device. For
13768 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
13769 specifying @code{"my-partition"} leads to the creation of
13770 the @code{"/dev/mapper/my-partition"} device.
13771 For RAID devices of type @code{raid-device-mapping}, the full device name
13772 such as @code{"/dev/md0"} needs to be given.
13773 LVM logical volumes of type @code{lvm-device-mapping} need to
13774 be specified as @code{"VGNAME-LVNAME"}.
13777 This list of strings specifies names of the resulting mapped devices in case
13778 there are several. The format is identical to @var{target}.
13781 This must be a @code{mapped-device-kind} object, which specifies how
13782 @var{source} is mapped to @var{target}.
13786 @defvr {Scheme Variable} luks-device-mapping
13787 This defines LUKS block device encryption using the @command{cryptsetup}
13788 command from the package with the same name. It relies on the
13789 @code{dm-crypt} Linux kernel module.
13792 @defvr {Scheme Variable} raid-device-mapping
13793 This defines a RAID device, which is assembled using the @code{mdadm}
13794 command from the package with the same name. It requires a Linux kernel
13795 module for the appropriate RAID level to be loaded, such as @code{raid456}
13796 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
13799 @cindex LVM, logical volume manager
13800 @defvr {Scheme Variable} lvm-device-mapping
13801 This defines one or more logical volumes for the Linux
13802 @uref{https://www.sourceware.org/lvm2/, Logical Volume Manager (LVM)}.
13803 The volume group is activated by the @command{vgchange} command from the
13804 @code{lvm2} package.
13807 @cindex disk encryption
13809 The following example specifies a mapping from @file{/dev/sda3} to
13810 @file{/dev/mapper/home} using LUKS---the
13811 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
13812 standard mechanism for disk encryption.
13813 The @file{/dev/mapper/home}
13814 device can then be used as the @code{device} of a @code{file-system}
13815 declaration (@pxref{File Systems}).
13819 (source "/dev/sda3")
13821 (type luks-device-mapping))
13824 Alternatively, to become independent of device numbering, one may obtain
13825 the LUKS UUID (@dfn{unique identifier}) of the source device by a
13829 cryptsetup luksUUID /dev/sda3
13832 and use it as follows:
13836 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
13838 (type luks-device-mapping))
13841 @cindex swap encryption
13842 It is also desirable to encrypt swap space, since swap space may contain
13843 sensitive data. One way to accomplish that is to use a swap file in a
13844 file system on a device mapped via LUKS encryption. In this way, the
13845 swap file is encrypted because the entire device is encrypted.
13846 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
13848 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
13849 may be declared as follows:
13853 (source (list "/dev/sda1" "/dev/sdb1"))
13854 (target "/dev/md0")
13855 (type raid-device-mapping))
13858 The @file{/dev/md0} device can then be used as the @code{device} of a
13859 @code{file-system} declaration (@pxref{File Systems}).
13860 Note that the RAID level need not be given; it is chosen during the
13861 initial creation and formatting of the RAID device and is determined
13862 automatically later.
13864 LVM logical volumes ``alpha'' and ``beta'' from volume group ``vg0'' can
13865 be declared as follows:
13870 (target (list "vg0-alpha" "vg0-beta"))
13871 (type lvm-device-mapping))
13874 Devices @file{/dev/mapper/vg0-alpha} and @file{/dev/mapper/vg0-beta} can
13875 then be used as the @code{device} of a @code{file-system} declaration
13876 (@pxref{File Systems}).
13878 @node User Accounts
13879 @section User Accounts
13883 @cindex user accounts
13884 User accounts and groups are entirely managed through the
13885 @code{operating-system} declaration. They are specified with the
13886 @code{user-account} and @code{user-group} forms:
13892 (supplementary-groups '("wheel" ;allow use of sudo, etc.
13893 "audio" ;sound card
13894 "video" ;video devices such as webcams
13895 "cdrom")) ;the good ol' CD-ROM
13896 (comment "Bob's sister"))
13899 Here's a user account that uses a different shell and a custom home
13900 directory (the default would be @file{"/home/bob"}):
13906 (comment "Alice's bro")
13907 (shell (file-append zsh "/bin/zsh"))
13908 (home-directory "/home/robert"))
13911 When booting or upon completion of @command{guix system reconfigure},
13912 the system ensures that only the user accounts and groups specified in
13913 the @code{operating-system} declaration exist, and with the specified
13914 properties. Thus, account or group creations or modifications made by
13915 directly invoking commands such as @command{useradd} are lost upon
13916 reconfiguration or reboot. This ensures that the system remains exactly
13919 @deftp {Data Type} user-account
13920 Objects of this type represent user accounts. The following members may
13925 The name of the user account.
13929 This is the name (a string) or identifier (a number) of the user group
13930 this account belongs to.
13932 @item @code{supplementary-groups} (default: @code{'()})
13933 Optionally, this can be defined as a list of group names that this
13934 account belongs to.
13936 @item @code{uid} (default: @code{#f})
13937 This is the user ID for this account (a number), or @code{#f}. In the
13938 latter case, a number is automatically chosen by the system when the
13939 account is created.
13941 @item @code{comment} (default: @code{""})
13942 A comment about the account, such as the account owner's full name.
13944 @item @code{home-directory}
13945 This is the name of the home directory for the account.
13947 @item @code{create-home-directory?} (default: @code{#t})
13948 Indicates whether the home directory of this account should be created
13949 if it does not exist yet.
13951 @item @code{shell} (default: Bash)
13952 This is a G-expression denoting the file name of a program to be used as
13953 the shell (@pxref{G-Expressions}). For example, you would refer to the
13954 Bash executable like this:
13957 (file-append bash "/bin/bash")
13961 ... and to the Zsh executable like that:
13964 (file-append zsh "/bin/zsh")
13967 @item @code{system?} (default: @code{#f})
13968 This Boolean value indicates whether the account is a ``system''
13969 account. System accounts are sometimes treated specially; for instance,
13970 graphical login managers do not list them.
13972 @anchor{user-account-password}
13973 @cindex password, for user accounts
13974 @item @code{password} (default: @code{#f})
13975 You would normally leave this field to @code{#f}, initialize user
13976 passwords as @code{root} with the @command{passwd} command, and then let
13977 users change it with @command{passwd}. Passwords set with
13978 @command{passwd} are of course preserved across reboot and
13981 If you @emph{do} want to set an initial password for an account, then
13982 this field must contain the encrypted password, as a string. You can use the
13983 @code{crypt} procedure for this purpose:
13990 ;; Specify a SHA-512-hashed initial password.
13991 (password (crypt "InitialPassword!" "$6$abc")))
13995 The hash of this initial password will be available in a file in
13996 @file{/gnu/store}, readable by all the users, so this method must be used with
14000 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
14001 more information on password encryption, and @ref{Encryption,,, guile, GNU
14002 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
14008 User group declarations are even simpler:
14011 (user-group (name "students"))
14014 @deftp {Data Type} user-group
14015 This type is for, well, user groups. There are just a few fields:
14019 The name of the group.
14021 @item @code{id} (default: @code{#f})
14022 The group identifier (a number). If @code{#f}, a new number is
14023 automatically allocated when the group is created.
14025 @item @code{system?} (default: @code{#f})
14026 This Boolean value indicates whether the group is a ``system'' group.
14027 System groups have low numerical IDs.
14029 @item @code{password} (default: @code{#f})
14030 What, user groups can have a password? Well, apparently yes. Unless
14031 @code{#f}, this field specifies the password of the group.
14036 For convenience, a variable lists all the basic user groups one may
14039 @defvr {Scheme Variable} %base-groups
14040 This is the list of basic user groups that users and/or packages expect
14041 to be present on the system. This includes groups such as ``root'',
14042 ``wheel'', and ``users'', as well as groups used to control access to
14043 specific devices such as ``audio'', ``disk'', and ``cdrom''.
14046 @defvr {Scheme Variable} %base-user-accounts
14047 This is the list of basic system accounts that programs may expect to
14048 find on a GNU/Linux system, such as the ``nobody'' account.
14050 Note that the ``root'' account is not included here. It is a
14051 special-case and is automatically added whether or not it is specified.
14054 @node Keyboard Layout
14055 @section Keyboard Layout
14057 @cindex keyboard layout
14059 To specify what each key of your keyboard does, you need to tell the operating
14060 system what @dfn{keyboard layout} you want to use. The default, when nothing
14061 is specified, is the US English QWERTY layout for 105-key PC keyboards.
14062 However, German speakers will usually prefer the German QWERTZ layout, French
14063 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
14064 or bépo, and they might even want to further customize the effect of some of
14065 the keys. This section explains how to get that done.
14067 @cindex keyboard layout, definition
14068 There are three components that will want to know about your keyboard layout:
14072 The @emph{bootloader} may want to know what keyboard layout you want to use
14073 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
14074 you want, for instance, to make sure that you can type the passphrase of your
14075 encrypted root partition using the right layout.
14078 The @emph{operating system kernel}, Linux, will need that so that the console
14079 is properly configured (@pxref{operating-system Reference,
14080 @code{keyboard-layout}}).
14083 The @emph{graphical display server}, usually Xorg, also has its own idea of
14084 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
14087 Guix allows you to configure all three separately but, fortunately, it allows
14088 you to share the same keyboard layout for all three components.
14090 @cindex XKB, keyboard layouts
14091 Keyboard layouts are represented by records created by the
14092 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
14093 the X Keyboard extension (XKB), each layout has four attributes: a name (often
14094 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
14095 optional variant name, an optional keyboard model name, and a possibly empty
14096 list of additional options. In most cases the layout name is all you care
14099 @deffn {Scheme Procedure} keyboard-layout @var{name} [@var{variant}] @
14100 [#:model] [#:options '()]
14101 Return a new keyboard layout with the given @var{name} and @var{variant}.
14103 @var{name} must be a string such as @code{"fr"}; @var{variant} must be a
14104 string such as @code{"bepo"} or @code{"nodeadkeys"}. See the
14105 @code{xkeyboard-config} package for valid options.
14108 Here are a few examples:
14111 ;; The German QWERTZ layout. Here we assume a standard
14112 ;; "pc105" keyboard model.
14113 (keyboard-layout "de")
14115 ;; The bépo variant of the French layout.
14116 (keyboard-layout "fr" "bepo")
14118 ;; The Catalan layout.
14119 (keyboard-layout "es" "cat")
14121 ;; Arabic layout with "Alt-Shift" to switch to US layout.
14122 (keyboard-layout "ar,us" #:options '("grp:alt_shift_toggle"))
14124 ;; The Latin American Spanish layout. In addition, the
14125 ;; "Caps Lock" key is used as an additional "Ctrl" key,
14126 ;; and the "Menu" key is used as a "Compose" key to enter
14127 ;; accented letters.
14128 (keyboard-layout "latam"
14129 #:options '("ctrl:nocaps" "compose:menu"))
14131 ;; The Russian layout for a ThinkPad keyboard.
14132 (keyboard-layout "ru" #:model "thinkpad")
14134 ;; The "US international" layout, which is the US layout plus
14135 ;; dead keys to enter accented characters. This is for an
14136 ;; Apple MacBook keyboard.
14137 (keyboard-layout "us" "intl" #:model "macbook78")
14140 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
14141 for a complete list of supported layouts, variants, and models.
14143 @cindex keyboard layout, configuration
14144 Let's say you want your system to use the Turkish keyboard layout throughout
14145 your system---bootloader, console, and Xorg. Here's what your system
14146 configuration would look like:
14148 @findex set-xorg-configuration
14150 ;; Using the Turkish layout for the bootloader, the console,
14155 (keyboard-layout (keyboard-layout "tr")) ;for the console
14156 (bootloader (bootloader-configuration
14157 (bootloader grub-efi-bootloader)
14158 (target "/boot/efi")
14159 (keyboard-layout keyboard-layout))) ;for GRUB
14160 (services (cons (set-xorg-configuration
14161 (xorg-configuration ;for Xorg
14162 (keyboard-layout keyboard-layout)))
14163 %desktop-services)))
14166 In the example above, for GRUB and for Xorg, we just refer to the
14167 @code{keyboard-layout} field defined above, but we could just as well refer to
14168 a different layout. The @code{set-xorg-configuration} procedure communicates
14169 the desired Xorg configuration to the graphical log-in manager, by default
14172 We've discussed how to specify the @emph{default} keyboard layout of your
14173 system when it starts, but you can also adjust it at run time:
14177 If you're using GNOME, its settings panel has a ``Region & Language'' entry
14178 where you can select one or more keyboard layouts.
14181 Under Xorg, the @command{setxkbmap} command (from the same-named package)
14182 allows you to change the current layout. For example, this is how you would
14183 change the layout to US Dvorak:
14186 setxkbmap us dvorak
14190 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
14191 console. However, note that @code{loadkeys} does @emph{not} use the XKB
14192 keyboard layout categorization described above. The command below loads the
14193 French bépo layout:
14204 A @dfn{locale} defines cultural conventions for a particular language
14205 and region of the world (@pxref{Locales,,, libc, The GNU C Library
14206 Reference Manual}). Each locale has a name that typically has the form
14207 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
14208 @code{fr_LU.utf8} designates the locale for the French language, with
14209 cultural conventions from Luxembourg, and using the UTF-8 encoding.
14211 @cindex locale definition
14212 Usually, you will want to specify the default locale for the machine
14213 using the @code{locale} field of the @code{operating-system} declaration
14214 (@pxref{operating-system Reference, @code{locale}}).
14216 The selected locale is automatically added to the @dfn{locale
14217 definitions} known to the system if needed, with its codeset inferred
14218 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
14219 @code{UTF-8} codeset. Additional locale definitions can be specified in
14220 the @code{locale-definitions} slot of @code{operating-system}---this is
14221 useful, for instance, if the codeset could not be inferred from the
14222 locale name. The default set of locale definitions includes some widely
14223 used locales, but not all the available locales, in order to save space.
14225 For instance, to add the North Frisian locale for Germany, the value of
14229 (cons (locale-definition
14230 (name "fy_DE.utf8") (source "fy_DE"))
14231 %default-locale-definitions)
14234 Likewise, to save space, one might want @code{locale-definitions} to
14235 list only the locales that are actually used, as in:
14238 (list (locale-definition
14239 (name "ja_JP.eucjp") (source "ja_JP")
14240 (charset "EUC-JP")))
14244 The compiled locale definitions are available at
14245 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
14246 version, which is the default location where the GNU@tie{}libc provided
14247 by Guix looks for locale data. This can be overridden using the
14248 @env{LOCPATH} environment variable (@pxref{locales-and-locpath,
14249 @env{LOCPATH} and locale packages}).
14251 The @code{locale-definition} form is provided by the @code{(gnu system
14252 locale)} module. Details are given below.
14254 @deftp {Data Type} locale-definition
14255 This is the data type of a locale definition.
14260 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
14261 Reference Manual}, for more information on locale names.
14263 @item @code{source}
14264 The name of the source for that locale. This is typically the
14265 @code{@var{language}_@var{territory}} part of the locale name.
14267 @item @code{charset} (default: @code{"UTF-8"})
14268 The ``character set'' or ``code set'' for that locale,
14269 @uref{https://www.iana.org/assignments/character-sets, as defined by
14275 @defvr {Scheme Variable} %default-locale-definitions
14276 A list of commonly used UTF-8 locales, used as the default
14277 value of the @code{locale-definitions} field of @code{operating-system}
14280 @cindex locale name
14281 @cindex normalized codeset in locale names
14282 These locale definitions use the @dfn{normalized codeset} for the part
14283 that follows the dot in the name (@pxref{Using gettextized software,
14284 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
14285 instance it has @code{uk_UA.utf8} but @emph{not}, say,
14286 @code{uk_UA.UTF-8}.
14289 @subsection Locale Data Compatibility Considerations
14291 @cindex incompatibility, of locale data
14292 @code{operating-system} declarations provide a @code{locale-libcs} field
14293 to specify the GNU@tie{}libc packages that are used to compile locale
14294 declarations (@pxref{operating-system Reference}). ``Why would I
14295 care?'', you may ask. Well, it turns out that the binary format of
14296 locale data is occasionally incompatible from one libc version to
14299 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
14300 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
14301 For instance, a program linked against libc version 2.21 is unable to
14302 read locale data produced with libc 2.22; worse, that program
14303 @emph{aborts} instead of simply ignoring the incompatible locale
14304 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
14305 the incompatible locale data, which is already an improvement.}.
14306 Similarly, a program linked against libc 2.22 can read most, but not
14307 all, of the locale data from libc 2.21 (specifically, @env{LC_COLLATE}
14308 data is incompatible); thus calls to @code{setlocale} may fail, but
14309 programs will not abort.
14311 The ``problem'' with Guix is that users have a lot of freedom: They can
14312 choose whether and when to upgrade software in their profiles, and might
14313 be using a libc version different from the one the system administrator
14314 used to build the system-wide locale data.
14316 Fortunately, unprivileged users can also install their own locale data
14317 and define @env{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
14318 @env{GUIX_LOCPATH} and locale packages}).
14320 Still, it is best if the system-wide locale data at
14321 @file{/run/current-system/locale} is built for all the libc versions
14322 actually in use on the system, so that all the programs can access
14323 it---this is especially crucial on a multi-user system. To do that, the
14324 administrator can specify several libc packages in the
14325 @code{locale-libcs} field of @code{operating-system}:
14328 (use-package-modules base)
14332 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
14335 This example would lead to a system containing locale definitions for
14336 both libc 2.21 and the current version of libc in
14337 @file{/run/current-system/locale}.
14343 @cindex system services
14344 An important part of preparing an @code{operating-system} declaration is
14345 listing @dfn{system services} and their configuration (@pxref{Using the
14346 Configuration System}). System services are typically daemons launched
14347 when the system boots, or other actions needed at that time---e.g.,
14348 configuring network access.
14350 Guix has a broad definition of ``service'' (@pxref{Service
14351 Composition}), but many services are managed by the GNU@tie{}Shepherd
14352 (@pxref{Shepherd Services}). On a running system, the @command{herd}
14353 command allows you to list the available services, show their status,
14354 start and stop them, or do other specific operations (@pxref{Jump
14355 Start,,, shepherd, The GNU Shepherd Manual}). For example:
14361 The above command, run as @code{root}, lists the currently defined
14362 services. The @command{herd doc} command shows a synopsis of the given
14363 service and its associated actions:
14367 Run libc's name service cache daemon (nscd).
14369 # herd doc nscd action invalidate
14370 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
14373 The @command{start}, @command{stop}, and @command{restart} sub-commands
14374 have the effect you would expect. For instance, the commands below stop
14375 the nscd service and restart the Xorg display server:
14379 Service nscd has been stopped.
14380 # herd restart xorg-server
14381 Service xorg-server has been stopped.
14382 Service xorg-server has been started.
14385 The following sections document the available services, starting with
14386 the core services, that may be used in an @code{operating-system}
14390 * Base Services:: Essential system services.
14391 * Scheduled Job Execution:: The mcron service.
14392 * Log Rotation:: The rottlog service.
14393 * Networking Services:: Network setup, SSH daemon, etc.
14394 * Unattended Upgrades:: Automated system upgrades.
14395 * X Window:: Graphical display.
14396 * Printing Services:: Local and remote printer support.
14397 * Desktop Services:: D-Bus and desktop services.
14398 * Sound Services:: ALSA and Pulseaudio services.
14399 * Database Services:: SQL databases, key-value stores, etc.
14400 * Mail Services:: IMAP, POP3, SMTP, and all that.
14401 * Messaging Services:: Messaging services.
14402 * Telephony Services:: Telephony services.
14403 * Monitoring Services:: Monitoring services.
14404 * Kerberos Services:: Kerberos services.
14405 * LDAP Services:: LDAP services.
14406 * Web Services:: Web servers.
14407 * Certificate Services:: TLS certificates via Let's Encrypt.
14408 * DNS Services:: DNS daemons.
14409 * VPN Services:: VPN daemons.
14410 * Network File System:: NFS related services.
14411 * Continuous Integration:: The Cuirass service.
14412 * Power Management Services:: Extending battery life.
14413 * Audio Services:: The MPD.
14414 * Virtualization Services:: Virtualization services.
14415 * Version Control Services:: Providing remote access to Git repositories.
14416 * Game Services:: Game servers.
14417 * PAM Mount Service:: Service to mount volumes when logging in.
14418 * Guix Services:: Services relating specifically to Guix.
14419 * Linux Services:: Services tied to the Linux kernel.
14420 * Hurd Services:: Services specific for a Hurd System.
14421 * Miscellaneous Services:: Other services.
14424 @node Base Services
14425 @subsection Base Services
14427 The @code{(gnu services base)} module provides definitions for the basic
14428 services that one expects from the system. The services exported by
14429 this module are listed below.
14431 @defvr {Scheme Variable} %base-services
14432 This variable contains a list of basic services (@pxref{Service Types
14433 and Services}, for more information on service objects) one would
14434 expect from the system: a login service (mingetty) on each tty, syslogd,
14435 the libc name service cache daemon (nscd), the udev device manager, and
14438 This is the default value of the @code{services} field of
14439 @code{operating-system} declarations. Usually, when customizing a
14440 system, you will want to append services to @code{%base-services}, like
14444 (append (list (service avahi-service-type)
14445 (service openssh-service-type))
14450 @defvr {Scheme Variable} special-files-service-type
14451 This is the service that sets up ``special files'' such as
14452 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
14454 The value associated with @code{special-files-service-type} services
14455 must be a list of tuples where the first element is the ``special file''
14456 and the second element is its target. By default it is:
14458 @cindex @file{/bin/sh}
14459 @cindex @file{sh}, in @file{/bin}
14461 `(("/bin/sh" ,(file-append bash "/bin/sh")))
14464 @cindex @file{/usr/bin/env}
14465 @cindex @file{env}, in @file{/usr/bin}
14466 If you want to add, say, @code{/usr/bin/env} to your system, you can
14470 `(("/bin/sh" ,(file-append bash "/bin/sh"))
14471 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
14474 Since this is part of @code{%base-services}, you can use
14475 @code{modify-services} to customize the set of special files
14476 (@pxref{Service Reference, @code{modify-services}}). But the simple way
14477 to add a special file is @i{via} the @code{extra-special-file} procedure
14481 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
14482 Use @var{target} as the ``special file'' @var{file}.
14484 For example, adding the following lines to the @code{services} field of
14485 your operating system declaration leads to a @file{/usr/bin/env}
14489 (extra-special-file "/usr/bin/env"
14490 (file-append coreutils "/bin/env"))
14494 @deffn {Scheme Procedure} host-name-service @var{name}
14495 Return a service that sets the host name to @var{name}.
14498 @defvr {Scheme Variable} console-font-service-type
14499 Install the given fonts on the specified ttys (fonts are per
14500 virtual console on the kernel Linux). The value of this service is a list of
14501 tty/font pairs. The font can be the name of a font provided by the @code{kbd}
14502 package or any valid argument to @command{setfont}, as in this example:
14505 `(("tty1" . "LatGrkCyr-8x16")
14506 ("tty2" . ,(file-append
14508 "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
14509 ("tty3" . ,(file-append
14511 "/share/consolefonts/ter-132n"))) ; for HDPI
14515 @deffn {Scheme Procedure} login-service @var{config}
14516 Return a service to run login according to @var{config}, a
14517 @code{<login-configuration>} object, which specifies the message of the day,
14518 among other things.
14521 @deftp {Data Type} login-configuration
14522 This is the data type representing the configuration of login.
14527 @cindex message of the day
14528 A file-like object containing the ``message of the day''.
14530 @item @code{allow-empty-passwords?} (default: @code{#t})
14531 Allow empty passwords by default so that first-time users can log in when
14532 the 'root' account has just been created.
14537 @deffn {Scheme Procedure} mingetty-service @var{config}
14538 Return a service to run mingetty according to @var{config}, a
14539 @code{<mingetty-configuration>} object, which specifies the tty to run, among
14543 @deftp {Data Type} mingetty-configuration
14544 This is the data type representing the configuration of Mingetty, which
14545 provides the default implementation of virtual console log-in.
14550 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
14552 @item @code{auto-login} (default: @code{#f})
14553 When true, this field must be a string denoting the user name under
14554 which the system automatically logs in. When it is @code{#f}, a
14555 user name and password must be entered to log in.
14557 @item @code{login-program} (default: @code{#f})
14558 This must be either @code{#f}, in which case the default log-in program
14559 is used (@command{login} from the Shadow tool suite), or a gexp denoting
14560 the name of the log-in program.
14562 @item @code{login-pause?} (default: @code{#f})
14563 When set to @code{#t} in conjunction with @var{auto-login}, the user
14564 will have to press a key before the log-in shell is launched.
14566 @item @code{clear-on-logout?} (default: @code{#t})
14567 When set to @code{#t}, the screen will be cleared after logout.
14569 @item @code{mingetty} (default: @var{mingetty})
14570 The Mingetty package to use.
14575 @deffn {Scheme Procedure} agetty-service @var{config}
14576 Return a service to run agetty according to @var{config}, an
14577 @code{<agetty-configuration>} object, which specifies the tty to run,
14578 among other things.
14581 @deftp {Data Type} agetty-configuration
14582 This is the data type representing the configuration of agetty, which
14583 implements virtual and serial console log-in. See the @code{agetty(8)}
14584 man page for more information.
14589 The name of the console this agetty runs on, as a string---e.g.,
14590 @code{"ttyS0"}. This argument is optional, it will default to
14591 a reasonable default serial port used by the kernel Linux.
14593 For this, if there is a value for an option @code{agetty.tty} in the kernel
14594 command line, agetty will extract the device name of the serial port
14595 from it and use that.
14597 If not and if there is a value for an option @code{console} with a tty in
14598 the Linux command line, agetty will extract the device name of the
14599 serial port from it and use that.
14601 In both cases, agetty will leave the other serial device settings
14602 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
14605 @item @code{baud-rate} (default: @code{#f})
14606 A string containing a comma-separated list of one or more baud rates, in
14609 @item @code{term} (default: @code{#f})
14610 A string containing the value used for the @env{TERM} environment
14613 @item @code{eight-bits?} (default: @code{#f})
14614 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
14617 @item @code{auto-login} (default: @code{#f})
14618 When passed a login name, as a string, the specified user will be logged
14619 in automatically without prompting for their login name or password.
14621 @item @code{no-reset?} (default: @code{#f})
14622 When @code{#t}, don't reset terminal cflags (control modes).
14624 @item @code{host} (default: @code{#f})
14625 This accepts a string containing the ``login_host'', which will be written
14626 into the @file{/var/run/utmpx} file.
14628 @item @code{remote?} (default: @code{#f})
14629 When set to @code{#t} in conjunction with @var{host}, this will add an
14630 @code{-r} fakehost option to the command line of the login program
14631 specified in @var{login-program}.
14633 @item @code{flow-control?} (default: @code{#f})
14634 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
14636 @item @code{no-issue?} (default: @code{#f})
14637 When set to @code{#t}, the contents of the @file{/etc/issue} file will
14638 not be displayed before presenting the login prompt.
14640 @item @code{init-string} (default: @code{#f})
14641 This accepts a string that will be sent to the tty or modem before
14642 sending anything else. It can be used to initialize a modem.
14644 @item @code{no-clear?} (default: @code{#f})
14645 When set to @code{#t}, agetty will not clear the screen before showing
14648 @item @code{login-program} (default: (file-append shadow "/bin/login"))
14649 This must be either a gexp denoting the name of a log-in program, or
14650 unset, in which case the default value is the @command{login} from the
14653 @item @code{local-line} (default: @code{#f})
14654 Control the CLOCAL line flag. This accepts one of three symbols as
14655 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
14656 the default value chosen by agetty is @code{'auto}.
14658 @item @code{extract-baud?} (default: @code{#f})
14659 When set to @code{#t}, instruct agetty to try to extract the baud rate
14660 from the status messages produced by certain types of modems.
14662 @item @code{skip-login?} (default: @code{#f})
14663 When set to @code{#t}, do not prompt the user for a login name. This
14664 can be used with @var{login-program} field to use non-standard login
14667 @item @code{no-newline?} (default: @code{#f})
14668 When set to @code{#t}, do not print a newline before printing the
14669 @file{/etc/issue} file.
14671 @c Is this dangerous only when used with login-program, or always?
14672 @item @code{login-options} (default: @code{#f})
14673 This option accepts a string containing options that are passed to the
14674 login program. When used with the @var{login-program}, be aware that a
14675 malicious user could try to enter a login name containing embedded
14676 options that could be parsed by the login program.
14678 @item @code{login-pause} (default: @code{#f})
14679 When set to @code{#t}, wait for any key before showing the login prompt.
14680 This can be used in conjunction with @var{auto-login} to save memory by
14681 lazily spawning shells.
14683 @item @code{chroot} (default: @code{#f})
14684 Change root to the specified directory. This option accepts a directory
14687 @item @code{hangup?} (default: @code{#f})
14688 Use the Linux system call @code{vhangup} to do a virtual hangup of the
14689 specified terminal.
14691 @item @code{keep-baud?} (default: @code{#f})
14692 When set to @code{#t}, try to keep the existing baud rate. The baud
14693 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
14696 @item @code{timeout} (default: @code{#f})
14697 When set to an integer value, terminate if no user name could be read
14698 within @var{timeout} seconds.
14700 @item @code{detect-case?} (default: @code{#f})
14701 When set to @code{#t}, turn on support for detecting an uppercase-only
14702 terminal. This setting will detect a login name containing only
14703 uppercase letters as indicating an uppercase-only terminal and turn on
14704 some upper-to-lower case conversions. Note that this will not support
14705 Unicode characters.
14707 @item @code{wait-cr?} (default: @code{#f})
14708 When set to @code{#t}, wait for the user or modem to send a
14709 carriage-return or linefeed character before displaying
14710 @file{/etc/issue} or login prompt. This is typically used with the
14711 @var{init-string} option.
14713 @item @code{no-hints?} (default: @code{#f})
14714 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
14717 @item @code{no-hostname?} (default: @code{#f})
14718 By default, the hostname is printed. When this option is set to
14719 @code{#t}, no hostname will be shown at all.
14721 @item @code{long-hostname?} (default: @code{#f})
14722 By default, the hostname is only printed until the first dot. When this
14723 option is set to @code{#t}, the fully qualified hostname by
14724 @code{gethostname} or @code{getaddrinfo} is shown.
14726 @item @code{erase-characters} (default: @code{#f})
14727 This option accepts a string of additional characters that should be
14728 interpreted as backspace when the user types their login name.
14730 @item @code{kill-characters} (default: @code{#f})
14731 This option accepts a string that should be interpreted to mean ``ignore
14732 all previous characters'' (also called a ``kill'' character) when the user
14733 types their login name.
14735 @item @code{chdir} (default: @code{#f})
14736 This option accepts, as a string, a directory path that will be changed
14739 @item @code{delay} (default: @code{#f})
14740 This options accepts, as an integer, the number of seconds to sleep
14741 before opening the tty and displaying the login prompt.
14743 @item @code{nice} (default: @code{#f})
14744 This option accepts, as an integer, the nice value with which to run the
14745 @command{login} program.
14747 @item @code{extra-options} (default: @code{'()})
14748 This option provides an ``escape hatch'' for the user to provide arbitrary
14749 command-line arguments to @command{agetty} as a list of strings.
14754 @deffn {Scheme Procedure} kmscon-service-type @var{config}
14755 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
14756 according to @var{config}, a @code{<kmscon-configuration>} object, which
14757 specifies the tty to run, among other things.
14760 @deftp {Data Type} kmscon-configuration
14761 This is the data type representing the configuration of Kmscon, which
14762 implements virtual console log-in.
14766 @item @code{virtual-terminal}
14767 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
14769 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
14770 A gexp denoting the name of the log-in program. The default log-in program is
14771 @command{login} from the Shadow tool suite.
14773 @item @code{login-arguments} (default: @code{'("-p")})
14774 A list of arguments to pass to @command{login}.
14776 @item @code{auto-login} (default: @code{#f})
14777 When passed a login name, as a string, the specified user will be logged
14778 in automatically without prompting for their login name or password.
14780 @item @code{hardware-acceleration?} (default: #f)
14781 Whether to use hardware acceleration.
14783 @item @code{kmscon} (default: @var{kmscon})
14784 The Kmscon package to use.
14789 @cindex name service cache daemon
14791 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
14792 [#:name-services '()]
14793 Return a service that runs the libc name service cache daemon (nscd) with the
14794 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
14795 Service Switch}, for an example.
14797 For convenience, the Shepherd service for nscd provides the following actions:
14801 @cindex cache invalidation, nscd
14802 @cindex nscd, cache invalidation
14803 This invalidate the given cache. For instance, running:
14806 herd invalidate nscd hosts
14810 invalidates the host name lookup cache of nscd.
14813 Running @command{herd statistics nscd} displays information about nscd usage
14819 @defvr {Scheme Variable} %nscd-default-configuration
14820 This is the default @code{<nscd-configuration>} value (see below) used
14821 by @code{nscd-service}. It uses the caches defined by
14822 @code{%nscd-default-caches}; see below.
14825 @deftp {Data Type} nscd-configuration
14826 This is the data type representing the name service cache daemon (nscd)
14831 @item @code{name-services} (default: @code{'()})
14832 List of packages denoting @dfn{name services} that must be visible to
14833 the nscd---e.g., @code{(list @var{nss-mdns})}.
14835 @item @code{glibc} (default: @var{glibc})
14836 Package object denoting the GNU C Library providing the @command{nscd}
14839 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
14840 Name of the nscd log file. This is where debugging output goes when
14841 @code{debug-level} is strictly positive.
14843 @item @code{debug-level} (default: @code{0})
14844 Integer denoting the debugging levels. Higher numbers mean that more
14845 debugging output is logged.
14847 @item @code{caches} (default: @code{%nscd-default-caches})
14848 List of @code{<nscd-cache>} objects denoting things to be cached; see
14854 @deftp {Data Type} nscd-cache
14855 Data type representing a cache database of nscd and its parameters.
14859 @item @code{database}
14860 This is a symbol representing the name of the database to be cached.
14861 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
14862 @code{services}, which designate the corresponding NSS database
14863 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
14865 @item @code{positive-time-to-live}
14866 @itemx @code{negative-time-to-live} (default: @code{20})
14867 A number representing the number of seconds during which a positive or
14868 negative lookup result remains in cache.
14870 @item @code{check-files?} (default: @code{#t})
14871 Whether to check for updates of the files corresponding to
14874 For instance, when @var{database} is @code{hosts}, setting this flag
14875 instructs nscd to check for updates in @file{/etc/hosts} and to take
14878 @item @code{persistent?} (default: @code{#t})
14879 Whether the cache should be stored persistently on disk.
14881 @item @code{shared?} (default: @code{#t})
14882 Whether the cache should be shared among users.
14884 @item @code{max-database-size} (default: 32@tie{}MiB)
14885 Maximum size in bytes of the database cache.
14887 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
14888 @c settings, so leave them out.
14893 @defvr {Scheme Variable} %nscd-default-caches
14894 List of @code{<nscd-cache>} objects used by default by
14895 @code{nscd-configuration} (see above).
14897 It enables persistent and aggressive caching of service and host name
14898 lookups. The latter provides better host name lookup performance,
14899 resilience in the face of unreliable name servers, and also better
14900 privacy---often the result of host name lookups is in local cache, so
14901 external name servers do not even need to be queried.
14904 @anchor{syslog-configuration-type}
14907 @deftp {Data Type} syslog-configuration
14908 This data type represents the configuration of the syslog daemon.
14911 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
14912 The syslog daemon to use.
14914 @item @code{config-file} (default: @code{%default-syslog.conf})
14915 The syslog configuration file to use.
14920 @anchor{syslog-service}
14922 @deffn {Scheme Procedure} syslog-service @var{config}
14923 Return a service that runs a syslog daemon according to @var{config}.
14925 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
14926 information on the configuration file syntax.
14929 @defvr {Scheme Variable} guix-service-type
14930 This is the type of the service that runs the build daemon,
14931 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
14932 @code{guix-configuration} record as described below.
14935 @anchor{guix-configuration-type}
14936 @deftp {Data Type} guix-configuration
14937 This data type represents the configuration of the Guix build daemon.
14938 @xref{Invoking guix-daemon}, for more information.
14941 @item @code{guix} (default: @var{guix})
14942 The Guix package to use.
14944 @item @code{build-group} (default: @code{"guixbuild"})
14945 Name of the group for build user accounts.
14947 @item @code{build-accounts} (default: @code{10})
14948 Number of build user accounts to create.
14950 @item @code{authorize-key?} (default: @code{#t})
14951 @cindex substitutes, authorization thereof
14952 Whether to authorize the substitute keys listed in
14953 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
14954 (@pxref{Substitutes}).
14956 When @code{authorize-key?} is true, @file{/etc/guix/acl} cannot be
14957 changed by invoking @command{guix archive --authorize}. You must
14958 instead adjust @code{guix-configuration} as you wish and reconfigure the
14959 system. This ensures that your operating system configuration file is
14963 When booting or reconfiguring to a system where @code{authorize-key?}
14964 is true, the existing @file{/etc/guix/acl} file is backed up as
14965 @file{/etc/guix/acl.bak} if it was determined to be a manually modified
14966 file. This is to facilitate migration from earlier versions, which
14967 allowed for in-place modifications to @file{/etc/guix/acl}.
14970 @vindex %default-authorized-guix-keys
14971 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
14972 The list of authorized key files for archive imports, as a list of
14973 string-valued gexps (@pxref{Invoking guix archive}). By default, it
14974 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
14975 See @code{substitute-urls} below for an example on how to change it.
14977 @item @code{use-substitutes?} (default: @code{#t})
14978 Whether to use substitutes.
14980 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
14981 The list of URLs where to look for substitutes by default.
14983 Suppose you would like to fetch substitutes from @code{guix.example.org}
14984 in addition to @code{@value{SUBSTITUTE-SERVER}}. You will need to do
14985 two things: (1) add @code{guix.example.org} to @code{substitute-urls},
14986 and (2) authorize its signing key, having done appropriate checks
14987 (@pxref{Substitute Server Authorization}). The configuration below does
14991 (guix-configuration
14993 (append (list "https://guix.example.org")
14994 %default-substitute-urls))
14996 (append (list (local-file "./guix.example.org-key.pub"))
14997 %default-authorized-guix-keys)))
15000 This example assumes that the file @file{./guix.example.org-key.pub}
15001 contains the public key that @code{guix.example.org} uses to sign
15004 @item @code{max-silent-time} (default: @code{0})
15005 @itemx @code{timeout} (default: @code{0})
15006 The number of seconds of silence and the number of seconds of activity,
15007 respectively, after which a build process times out. A value of zero
15008 disables the timeout.
15010 @item @code{log-compression} (default: @code{'bzip2})
15011 The type of compression used for build logs---one of @code{gzip},
15012 @code{bzip2}, or @code{none}.
15014 @item @code{extra-options} (default: @code{'()})
15015 List of extra command-line options for @command{guix-daemon}.
15017 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
15018 File where @command{guix-daemon}'s standard output and standard error
15021 @cindex HTTP proxy, for @code{guix-daemon}
15022 @cindex proxy, for @code{guix-daemon} HTTP access
15023 @item @code{http-proxy} (default: @code{#f})
15024 The URL of the HTTP and HTTPS proxy used for downloading fixed-output
15025 derivations and substitutes.
15027 It is also possible to change the daemon's proxy at run time through the
15028 @code{set-http-proxy} action, which restarts it:
15031 herd set-http-proxy guix-daemon http://localhost:8118
15034 To clear the proxy settings, run:
15037 herd set-http-proxy guix-daemon
15040 @item @code{tmpdir} (default: @code{#f})
15041 A directory path where the @command{guix-daemon} will perform builds.
15046 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
15047 Run @var{udev}, which populates the @file{/dev} directory dynamically.
15048 udev rules can be provided as a list of files through the @var{rules}
15049 variable. The procedures @code{udev-rule}, @code{udev-rules-service}
15050 and @code{file->udev-rule} from @code{(gnu services base)} simplify the
15051 creation of such rule files.
15053 The @command{herd rules udev} command, as root, returns the name of the
15054 directory containing all the active udev rules.
15057 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
15058 Return a udev-rule file named @var{file-name} containing the rules
15059 defined by the @var{contents} literal.
15061 In the following example, a rule for a USB device is defined to be
15062 stored in the file @file{90-usb-thing.rules}. The rule runs a script
15063 upon detecting a USB device with a given product identifier.
15066 (define %example-udev-rule
15068 "90-usb-thing.rules"
15069 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
15070 "ATTR@{product@}==\"Example\", "
15071 "RUN+=\"/path/to/script\"")))
15075 @deffn {Scheme Procedure} udev-rules-service [@var{name} @var{rules}] @
15076 [#:groups @var{groups}]
15077 Return a service that extends @code{udev-service-type } with @var{rules}
15078 and @code{account-service-type} with @var{groups} as system groups.
15079 This works by creating a singleton service type
15080 @code{@var{name}-udev-rules}, of which the returned service is an
15083 Here we show how it can be used to extend @code{udev-service-type} with the
15084 previously defined rule @code{%example-udev-rule}.
15090 (cons (udev-rules-service 'usb-thing %example-udev-rule)
15091 %desktop-services)))
15095 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
15096 Return a udev file named @var{file-name} containing the rules defined
15097 within @var{file}, a file-like object.
15099 The following example showcases how we can use an existing rule file.
15102 (use-modules (guix download) ;for url-fetch
15103 (guix packages) ;for origin
15106 (define %android-udev-rules
15108 "51-android-udev.rules"
15109 (let ((version "20170910"))
15112 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
15113 "android-udev-rules/" version "/51-android.rules"))
15115 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
15119 Additionally, Guix package definitions can be included in @var{rules} in
15120 order to extend the udev rules with the definitions found under their
15121 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
15122 @var{file->udev-rule} example, we could have used the
15123 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
15124 packages android)} module.
15126 The following example shows how to use the @var{android-udev-rules}
15127 package so that the Android tool @command{adb} can detect devices
15128 without root privileges. It also details how to create the
15129 @code{adbusers} group, which is required for the proper functioning of
15130 the rules defined within the @code{android-udev-rules} package. To
15131 create such a group, we must define it both as part of the
15132 @code{supplementary-groups} of our @code{user-account} declaration, as
15133 well as in the @var{groups} of the @code{udev-rules-service} procedure.
15136 (use-modules (gnu packages android) ;for android-udev-rules
15137 (gnu system shadow) ;for user-group
15142 (users (cons (user-account
15144 (supplementary-groups
15145 '("adbusers" ;for adb
15146 "wheel" "netdev" "audio" "video")))))
15149 (cons (udev-rules-service 'android android-udev-rules
15150 #:groups '("adbusers"))
15151 %desktop-services)))
15154 @defvr {Scheme Variable} urandom-seed-service-type
15155 Save some entropy in @code{%random-seed-file} to seed @file{/dev/urandom}
15156 when rebooting. It also tries to seed @file{/dev/urandom} from
15157 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
15161 @defvr {Scheme Variable} %random-seed-file
15162 This is the name of the file where some random bytes are saved by
15163 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
15164 It defaults to @file{/var/lib/random-seed}.
15169 @defvr {Scheme Variable} gpm-service-type
15170 This is the type of the service that runs GPM, the @dfn{general-purpose
15171 mouse daemon}, which provides mouse support to the Linux console. GPM
15172 allows users to use the mouse in the console, notably to select, copy,
15175 The value for services of this type must be a @code{gpm-configuration}
15176 (see below). This service is not part of @code{%base-services}.
15179 @deftp {Data Type} gpm-configuration
15180 Data type representing the configuration of GPM.
15183 @item @code{options} (default: @code{%default-gpm-options})
15184 Command-line options passed to @command{gpm}. The default set of
15185 options instruct @command{gpm} to listen to mouse events on
15186 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
15189 @item @code{gpm} (default: @code{gpm})
15190 The GPM package to use.
15195 @anchor{guix-publish-service-type}
15196 @deffn {Scheme Variable} guix-publish-service-type
15197 This is the service type for @command{guix publish} (@pxref{Invoking
15198 guix publish}). Its value must be a @code{guix-publish-configuration}
15199 object, as described below.
15201 This assumes that @file{/etc/guix} already contains a signing key pair as
15202 created by @command{guix archive --generate-key} (@pxref{Invoking guix
15203 archive}). If that is not the case, the service will fail to start.
15206 @deftp {Data Type} guix-publish-configuration
15207 Data type representing the configuration of the @code{guix publish}
15211 @item @code{guix} (default: @code{guix})
15212 The Guix package to use.
15214 @item @code{port} (default: @code{80})
15215 The TCP port to listen for connections.
15217 @item @code{host} (default: @code{"localhost"})
15218 The host (and thus, network interface) to listen to. Use
15219 @code{"0.0.0.0"} to listen on all the network interfaces.
15221 @item @code{compression} (default: @code{'(("gzip" 3))})
15222 This is a list of compression method/level tuple used when compressing
15223 substitutes. For example, to compress all substitutes with @emph{both} lzip
15224 at level 7 and gzip at level 9, write:
15227 '(("lzip" 7) ("gzip" 9))
15230 Level 9 achieves the best compression ratio at the expense of increased CPU
15231 usage, whereas level 1 achieves fast compression.
15233 An empty list disables compression altogether.
15235 @item @code{nar-path} (default: @code{"nar"})
15236 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
15237 publish, @option{--nar-path}}, for details.
15239 @item @code{cache} (default: @code{#f})
15240 When it is @code{#f}, disable caching and instead generate archives on
15241 demand. Otherwise, this should be the name of a directory---e.g.,
15242 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
15243 archives and meta-data ready to be sent. @xref{Invoking guix publish,
15244 @option{--cache}}, for more information on the tradeoffs involved.
15246 @item @code{workers} (default: @code{#f})
15247 When it is an integer, this is the number of worker threads used for
15248 caching; when @code{#f}, the number of processors is used.
15249 @xref{Invoking guix publish, @option{--workers}}, for more information.
15251 @item @code{cache-bypass-threshold} (default: 10 MiB)
15252 When @code{cache} is true, this is the maximum size in bytes of a store
15253 item for which @command{guix publish} may bypass its cache in case of a
15254 cache miss. @xref{Invoking guix publish,
15255 @option{--cache-bypass-threshold}}, for more information.
15257 @item @code{ttl} (default: @code{#f})
15258 When it is an integer, this denotes the @dfn{time-to-live} in seconds
15259 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
15260 for more information.
15264 @anchor{rngd-service}
15265 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
15266 [#:device "/dev/hwrng"]
15267 Return a service that runs the @command{rngd} program from @var{rng-tools}
15268 to add @var{device} to the kernel's entropy pool. The service will fail if
15269 @var{device} does not exist.
15272 @anchor{pam-limits-service}
15273 @cindex session limits
15278 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
15280 Return a service that installs a configuration file for the
15281 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
15282 @code{pam_limits} module}. The procedure optionally takes a list of
15283 @code{pam-limits-entry} values, which can be used to specify
15284 @code{ulimit} limits and nice priority limits to user sessions.
15286 The following limits definition sets two hard and soft limits for all
15287 login sessions of users in the @code{realtime} group:
15290 (pam-limits-service
15292 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
15293 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
15296 The first entry increases the maximum realtime priority for
15297 non-privileged processes; the second entry lifts any restriction of the
15298 maximum address space that can be locked in memory. These settings are
15299 commonly used for real-time audio systems.
15302 @node Scheduled Job Execution
15303 @subsection Scheduled Job Execution
15307 @cindex scheduling jobs
15308 The @code{(gnu services mcron)} module provides an interface to
15309 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
15310 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
15311 Unix @command{cron} daemon; the main difference is that it is
15312 implemented in Guile Scheme, which provides a lot of flexibility when
15313 specifying the scheduling of jobs and their actions.
15315 The example below defines an operating system that runs the
15316 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
15317 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
15318 well as the @command{mkid} command on behalf of an unprivileged user
15319 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
15320 gexps to introduce job definitions that are passed to mcron
15321 (@pxref{G-Expressions}).
15324 (use-modules (guix) (gnu) (gnu services mcron))
15325 (use-package-modules base idutils)
15327 (define updatedb-job
15328 ;; Run 'updatedb' at 3AM every day. Here we write the
15329 ;; job's action as a Scheme procedure.
15330 #~(job '(next-hour '(3))
15332 (execl (string-append #$findutils "/bin/updatedb")
15334 "--prunepaths=/tmp /var/tmp /gnu/store"))))
15336 (define garbage-collector-job
15337 ;; Collect garbage 5 minutes after midnight every day.
15338 ;; The job's action is a shell command.
15339 #~(job "5 0 * * *" ;Vixie cron syntax
15342 (define idutils-job
15343 ;; Update the index database as user "charlie" at 12:15PM
15344 ;; and 19:15PM. This runs from the user's home directory.
15345 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
15346 (string-append #$idutils "/bin/mkid src")
15352 ;; %BASE-SERVICES already includes an instance of
15353 ;; 'mcron-service-type', which we extend with additional
15354 ;; jobs using 'simple-service'.
15355 (services (cons (simple-service 'my-cron-jobs
15357 (list garbage-collector-job
15363 For more complex jobs defined in Scheme where you need control over the top
15364 level, for instance to introduce a @code{use-modules} form, you can move your
15365 code to a separate program using the @code{program-file} procedure of the
15366 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
15370 (define %battery-alert-job
15371 ;; Beep when the battery percentage falls below %MIN-LEVEL.
15373 '(next-minute (range 0 60 1))
15375 "battery-alert.scm"
15376 (with-imported-modules (source-module-closure
15377 '((guix build utils)))
15379 (use-modules (guix build utils)
15382 (ice-9 textual-ports)
15385 (define %min-level 20)
15387 (setenv "LC_ALL" "C") ;ensure English output
15388 (and-let* ((input-pipe (open-pipe*
15390 #$(file-append acpi "/bin/acpi")))
15391 (output (get-string-all input-pipe))
15392 (m (string-match "Discharging, ([0-9]+)%" output))
15393 (level (string->number (match:substring m 1)))
15394 ((< level %min-level)))
15395 (format #t "warning: Battery level is low (~a%)~%" level)
15396 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
15399 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
15400 for more information on mcron job specifications. Below is the
15401 reference of the mcron service.
15403 On a running system, you can use the @code{schedule} action of the service to
15404 visualize the mcron jobs that will be executed next:
15407 # herd schedule mcron
15411 The example above lists the next five tasks that will be executed, but you can
15412 also specify the number of tasks to display:
15415 # herd schedule mcron 10
15418 @defvr {Scheme Variable} mcron-service-type
15419 This is the type of the @code{mcron} service, whose value is an
15420 @code{mcron-configuration} object.
15422 This service type can be the target of a service extension that provides
15423 it additional job specifications (@pxref{Service Composition}). In
15424 other words, it is possible to define services that provide additional
15428 @deftp {Data Type} mcron-configuration
15429 Data type representing the configuration of mcron.
15432 @item @code{mcron} (default: @var{mcron})
15433 The mcron package to use.
15436 This is a list of gexps (@pxref{G-Expressions}), where each gexp
15437 corresponds to an mcron job specification (@pxref{Syntax, mcron job
15438 specifications,, mcron, GNU@tie{}mcron}).
15444 @subsection Log Rotation
15447 @cindex log rotation
15449 Log files such as those found in @file{/var/log} tend to grow endlessly,
15450 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
15451 their contents in separate files, possibly compressed. The @code{(gnu
15452 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
15453 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
15455 This service is part of @code{%base-services}, and thus enabled by
15456 default, with the default settings, for commonly encountered log files.
15457 The example below shows how to extend it with an additional
15458 @dfn{rotation}, should you need to do that (usually, services that
15459 produce log files already take care of that):
15462 (use-modules (guix) (gnu))
15463 (use-service-modules admin)
15465 (define my-log-files
15466 ;; Log files that I want to rotate.
15467 '("/var/log/something.log" "/var/log/another.log"))
15471 (services (cons (simple-service 'rotate-my-stuff
15472 rottlog-service-type
15473 (list (log-rotation
15475 (files my-log-files))))
15479 @defvr {Scheme Variable} rottlog-service-type
15480 This is the type of the Rottlog service, whose value is a
15481 @code{rottlog-configuration} object.
15483 Other services can extend this one with new @code{log-rotation} objects
15484 (see below), thereby augmenting the set of files to be rotated.
15486 This service type can define mcron jobs (@pxref{Scheduled Job
15487 Execution}) to run the rottlog service.
15490 @deftp {Data Type} rottlog-configuration
15491 Data type representing the configuration of rottlog.
15494 @item @code{rottlog} (default: @code{rottlog})
15495 The Rottlog package to use.
15497 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
15498 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
15499 rottlog, GNU Rot[t]log Manual}).
15501 @item @code{rotations} (default: @code{%default-rotations})
15502 A list of @code{log-rotation} objects as defined below.
15505 This is a list of gexps where each gexp corresponds to an mcron job
15506 specification (@pxref{Scheduled Job Execution}).
15510 @deftp {Data Type} log-rotation
15511 Data type representing the rotation of a group of log files.
15513 Taking an example from the Rottlog manual (@pxref{Period Related File
15514 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
15520 (files '("/var/log/apache/*"))
15521 (options '("storedir apache-archives"
15527 The list of fields is as follows:
15530 @item @code{frequency} (default: @code{'weekly})
15531 The log rotation frequency, a symbol.
15534 The list of files or file glob patterns to rotate.
15536 @item @code{options} (default: @code{'()})
15537 The list of rottlog options for this rotation (@pxref{Configuration
15538 parameters,,, rottlog, GNU Rot[t]lg Manual}).
15540 @item @code{post-rotate} (default: @code{#f})
15541 Either @code{#f} or a gexp to execute once the rotation has completed.
15545 @defvr {Scheme Variable} %default-rotations
15546 Specifies weekly rotation of @code{%rotated-files} and of
15547 @file{/var/log/guix-daemon.log}.
15550 @defvr {Scheme Variable} %rotated-files
15551 The list of syslog-controlled files to be rotated. By default it is:
15552 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
15553 "/var/log/maillog")}.
15556 @node Networking Services
15557 @subsection Networking Services
15559 The @code{(gnu services networking)} module provides services to configure
15560 the network interface.
15562 @cindex DHCP, networking service
15563 @defvr {Scheme Variable} dhcp-client-service-type
15564 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
15565 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
15566 is the DHCP client package to use, @code{isc-dhcp} by default.
15569 @deffn {Scheme Procedure} dhcpd-service-type
15570 This type defines a service that runs a DHCP daemon. To create a
15571 service of this type, you must supply a @code{<dhcpd-configuration>}.
15575 (service dhcpd-service-type
15576 (dhcpd-configuration
15577 (config-file (local-file "my-dhcpd.conf"))
15578 (interfaces '("enp0s25"))))
15582 @deftp {Data Type} dhcpd-configuration
15584 @item @code{package} (default: @code{isc-dhcp})
15585 The package that provides the DHCP daemon. This package is expected to
15586 provide the daemon at @file{sbin/dhcpd} relative to its output
15587 directory. The default package is the
15588 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
15589 @item @code{config-file} (default: @code{#f})
15590 The configuration file to use. This is required. It will be passed to
15591 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
15592 object (@pxref{G-Expressions, file-like objects}). See @code{man
15593 dhcpd.conf} for details on the configuration file syntax.
15594 @item @code{version} (default: @code{"4"})
15595 The DHCP version to use. The ISC DHCP server supports the values ``4'',
15596 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
15597 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
15599 @item @code{run-directory} (default: @code{"/run/dhcpd"})
15600 The run directory to use. At service activation time, this directory
15601 will be created if it does not exist.
15602 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
15603 The PID file to use. This corresponds to the @code{-pf} option of
15604 @code{dhcpd}. See @code{man dhcpd} for details.
15605 @item @code{interfaces} (default: @code{'()})
15606 The names of the network interfaces on which dhcpd should listen for
15607 broadcasts. If this list is not empty, then its elements (which must be
15608 strings) will be appended to the @code{dhcpd} invocation when starting
15609 the daemon. It may not be necessary to explicitly specify any
15610 interfaces here; see @code{man dhcpd} for details.
15614 @defvr {Scheme Variable} static-networking-service-type
15615 This is the type for statically-configured network interfaces.
15616 @c TODO Document <static-networking> data structures.
15619 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
15620 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
15621 [#:requirement @code{'(udev)}]
15622 Return a service that starts @var{interface} with address @var{ip}. If
15623 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
15624 it must be a string specifying the default network gateway. @var{requirement}
15625 can be used to declare a dependency on another service before configuring the
15628 This procedure can be called several times, one for each network
15629 interface of interest. Behind the scenes what it does is extend
15630 @code{static-networking-service-type} with additional network interfaces
15636 (static-networking-service "eno1" "192.168.1.82"
15637 #:gateway "192.168.1.2"
15638 #:name-servers '("192.168.1.2"))
15645 @cindex network management
15646 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
15647 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
15648 management daemon that aims to simplify wired and wireless networking.
15650 This service adds the @var{wicd} package to the global profile, providing
15651 several commands to interact with the daemon and configure networking:
15652 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
15653 and @command{wicd-curses} user interfaces.
15656 @cindex ModemManager
15658 @defvr {Scheme Variable} modem-manager-service-type
15659 This is the service type for the
15660 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
15661 service. The value for this service type is a
15662 @code{modem-manager-configuration} record.
15664 This service is part of @code{%desktop-services} (@pxref{Desktop
15668 @deftp {Data Type} modem-manager-configuration
15669 Data type representing the configuration of ModemManager.
15672 @item @code{modem-manager} (default: @code{modem-manager})
15673 The ModemManager package to use.
15678 @cindex USB_ModeSwitch
15679 @cindex Modeswitching
15681 @defvr {Scheme Variable} usb-modeswitch-service-type
15682 This is the service type for the
15683 @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch} service. The
15684 value for this service type is a @code{usb-modeswitch-configuration} record.
15686 When plugged in, some USB modems (and other USB devices) initially present
15687 themselves as a read-only storage medium and not as a modem. They need to be
15688 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
15689 installs udev rules to automatically modeswitch these devices when they are
15692 This service is part of @code{%desktop-services} (@pxref{Desktop
15696 @deftp {Data Type} usb-modeswitch-configuration
15697 Data type representing the configuration of USB_ModeSwitch.
15700 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
15701 The USB_ModeSwitch package providing the binaries for modeswitching.
15703 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
15704 The package providing the device data and udev rules file used by
15707 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
15708 Which config file to use for the USB_ModeSwitch dispatcher. By default the
15709 config file shipped with USB_ModeSwitch is used which disables logging to
15710 @file{/var/log} among other default settings. If set to @code{#f}, no config
15716 @cindex NetworkManager
15718 @defvr {Scheme Variable} network-manager-service-type
15719 This is the service type for the
15720 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
15721 service. The value for this service type is a
15722 @code{network-manager-configuration} record.
15724 This service is part of @code{%desktop-services} (@pxref{Desktop
15728 @deftp {Data Type} network-manager-configuration
15729 Data type representing the configuration of NetworkManager.
15732 @item @code{network-manager} (default: @code{network-manager})
15733 The NetworkManager package to use.
15735 @item @code{dns} (default: @code{"default"})
15736 Processing mode for DNS, which affects how NetworkManager uses the
15737 @code{resolv.conf} configuration file.
15741 NetworkManager will update @code{resolv.conf} to reflect the nameservers
15742 provided by currently active connections.
15745 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
15746 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
15747 then update @code{resolv.conf} to point to the local nameserver.
15749 With this setting, you can share your network connection. For example when
15750 you want to share your network connection to another laptop @i{via} an
15751 Ethernet cable, you can open @command{nm-connection-editor} and configure the
15752 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
15753 and reestablish the connection (or reboot).
15755 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
15756 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
15757 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
15758 browser on your host system, or connect to the VM @i{via} SSH
15759 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
15760 host-to-guest connection, run this command once:
15763 nmcli connection add type tun \
15764 connection.interface-name tap0 \
15765 tun.mode tap tun.owner $(id -u) \
15766 ipv4.method shared \
15767 ipv4.addresses 172.28.112.1/24
15770 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
15771 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
15772 @command{qemu-system-...}.
15775 NetworkManager will not modify @code{resolv.conf}.
15778 @item @code{vpn-plugins} (default: @code{'()})
15779 This is the list of available plugins for virtual private networks
15780 (VPNs). An example of this is the @code{network-manager-openvpn}
15781 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
15787 @deffn {Scheme Variable} connman-service-type
15788 This is the service type to run @url{https://01.org/connman,Connman},
15789 a network connection manager.
15791 Its value must be an
15792 @code{connman-configuration} record as in this example:
15795 (service connman-service-type
15796 (connman-configuration
15797 (disable-vpn? #t)))
15800 See below for details about @code{connman-configuration}.
15803 @deftp {Data Type} connman-configuration
15804 Data Type representing the configuration of connman.
15807 @item @code{connman} (default: @var{connman})
15808 The connman package to use.
15810 @item @code{disable-vpn?} (default: @code{#f})
15811 When true, disable connman's vpn plugin.
15815 @cindex WPA Supplicant
15816 @defvr {Scheme Variable} wpa-supplicant-service-type
15817 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
15818 supplicant}, an authentication daemon required to authenticate against
15819 encrypted WiFi or ethernet networks.
15822 @deftp {Data Type} wpa-supplicant-configuration
15823 Data type representing the configuration of WPA Supplicant.
15825 It takes the following parameters:
15828 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
15829 The WPA Supplicant package to use.
15831 @item @code{requirement} (default: @code{'(user-processes loopback syslogd)}
15832 List of services that should be started before WPA Supplicant starts.
15834 @item @code{dbus?} (default: @code{#t})
15835 Whether to listen for requests on D-Bus.
15837 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
15838 Where to store the PID file.
15840 @item @code{interface} (default: @code{#f})
15841 If this is set, it must specify the name of a network interface that
15842 WPA supplicant will control.
15844 @item @code{config-file} (default: @code{#f})
15845 Optional configuration file to use.
15847 @item @code{extra-options} (default: @code{'()})
15848 List of additional command-line arguments to pass to the daemon.
15852 @cindex hostapd service, for Wi-Fi access points
15853 @cindex Wi-Fi access points, hostapd service
15854 @defvr {Scheme Variable} hostapd-service-type
15855 This is the service type to run the @uref{https://w1.fi/hostapd/,
15856 hostapd} daemon to set up WiFi (IEEE 802.11) access points and
15857 authentication servers. Its associated value must be a
15858 @code{hostapd-configuration} as shown below:
15861 ;; Use wlan1 to run the access point for "My Network".
15862 (service hostapd-service-type
15863 (hostapd-configuration
15864 (interface "wlan1")
15865 (ssid "My Network")
15870 @deftp {Data Type} hostapd-configuration
15871 This data type represents the configuration of the hostapd service, with
15872 the following fields:
15875 @item @code{package} (default: @code{hostapd})
15876 The hostapd package to use.
15878 @item @code{interface} (default: @code{"wlan0"})
15879 The network interface to run the WiFi access point.
15882 The SSID (@dfn{service set identifier}), a string that identifies this
15885 @item @code{broadcast-ssid?} (default: @code{#t})
15886 Whether to broadcast this SSID.
15888 @item @code{channel} (default: @code{1})
15889 The WiFi channel to use.
15891 @item @code{driver} (default: @code{"nl80211"})
15892 The driver interface type. @code{"nl80211"} is used with all Linux
15893 mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
15894 RADIUS server that does # not control any wireless/wired driver.
15896 @item @code{extra-settings} (default: @code{""})
15897 Extra settings to append as-is to the hostapd configuration file. See
15898 @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
15899 configuration file reference.
15903 @defvr {Scheme Variable} simulated-wifi-service-type
15904 This is the type of a service to simulate WiFi networking, which can be
15905 useful in virtual machines for testing purposes. The service loads the
15907 @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
15908 @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
15909 network that can be seen on @code{wlan0}, by default.
15911 The service's value is a @code{hostapd-configuration} record.
15915 @defvr {Scheme Variable} iptables-service-type
15916 This is the service type to set up an iptables configuration. iptables is a
15917 packet filtering framework supported by the Linux kernel. This service
15918 supports configuring iptables for both IPv4 and IPv6. A simple example
15919 configuration rejecting all incoming connections except those to the ssh port
15923 (service iptables-service-type
15924 (iptables-configuration
15925 (ipv4-rules (plain-file "iptables.rules" "*filter
15929 -A INPUT -p tcp --dport 22 -j ACCEPT
15930 -A INPUT -j REJECT --reject-with icmp-port-unreachable
15933 (ipv6-rules (plain-file "ip6tables.rules" "*filter
15937 -A INPUT -p tcp --dport 22 -j ACCEPT
15938 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
15944 @deftp {Data Type} iptables-configuration
15945 The data type representing the configuration of iptables.
15948 @item @code{iptables} (default: @code{iptables})
15949 The iptables package that provides @code{iptables-restore} and
15950 @code{ip6tables-restore}.
15951 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
15952 The iptables rules to use. It will be passed to @code{iptables-restore}.
15953 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
15955 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
15956 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
15957 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
15963 @defvr {Scheme Variable} nftables-service-type
15964 This is the service type to set up a nftables configuration. nftables is a
15965 netfilter project that aims to replace the existing iptables, ip6tables,
15966 arptables and ebtables framework. It provides a new packet filtering
15967 framework, a new user-space utility @command{nft}, and a compatibility layer
15968 for iptables. This service comes with a default ruleset
15969 @code{%default-nftables-ruleset} that rejecting all incomming connections
15970 except those to the ssh port 22. To use it, simply write:
15973 (service nftables-service-type)
15977 @deftp {Data Type} nftables-configuration
15978 The data type representing the configuration of nftables.
15981 @item @code{package} (default: @code{nftables})
15982 The nftables package that provides @command{nft}.
15983 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
15984 The nftables ruleset to use. This may be any ``file-like'' object
15985 (@pxref{G-Expressions, file-like objects}).
15989 @cindex NTP (Network Time Protocol), service
15990 @cindex ntpd, service for the Network Time Protocol daemon
15991 @cindex real time clock
15992 @defvr {Scheme Variable} ntp-service-type
15993 This is the type of the service running the @uref{https://www.ntp.org,
15994 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
15995 system clock synchronized with that of the specified NTP servers.
15997 The value of this service is an @code{ntpd-configuration} object, as described
16001 @deftp {Data Type} ntp-configuration
16002 This is the data type for the NTP service configuration.
16005 @item @code{servers} (default: @code{%ntp-servers})
16006 This is the list of servers (@code{<ntp-server>} records) with which
16007 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
16010 @item @code{allow-large-adjustment?} (default: @code{#t})
16011 This determines whether @command{ntpd} is allowed to make an initial
16012 adjustment of more than 1,000 seconds.
16014 @item @code{ntp} (default: @code{ntp})
16015 The NTP package to use.
16019 @defvr {Scheme Variable} %ntp-servers
16020 List of host names used as the default NTP servers. These are servers of the
16021 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
16024 @deftp {Data Type} ntp-server
16025 The data type representing the configuration of a NTP server.
16028 @item @code{type} (default: @code{'server})
16029 The type of the NTP server, given as a symbol. One of @code{'pool},
16030 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
16032 @item @code{address}
16033 The address of the server, as a string.
16035 @item @code{options}
16036 NTPD options to use with that specific server, given as a list of option names
16037 and/or of option names and values tuples. The following example define a server
16038 to use with the options @option{iburst} and @option{prefer}, as well as
16039 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
16044 (address "some.ntp.server.org")
16045 (options `(iburst (version 3) (maxpoll 16) prefer))))
16051 @deffn {Scheme Procedure} openntpd-service-type
16052 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
16053 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
16054 clock synchronized with that of the given servers.
16058 openntpd-service-type
16059 (openntpd-configuration
16060 (listen-on '("127.0.0.1" "::1"))
16061 (sensor '("udcf0 correction 70000"))
16062 (constraint-from '("www.gnu.org"))
16063 (constraints-from '("https://www.google.com/"))
16064 (allow-large-adjustment? #t)))
16069 @defvr {Scheme Variable} %openntpd-servers
16070 This variable is a list of the server addresses defined in
16071 @code{%ntp-servers}.
16074 @deftp {Data Type} openntpd-configuration
16076 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
16077 The openntpd executable to use.
16078 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
16079 A list of local IP addresses or hostnames the ntpd daemon should listen on.
16080 @item @code{query-from} (default: @code{'()})
16081 A list of local IP address the ntpd daemon should use for outgoing queries.
16082 @item @code{sensor} (default: @code{'()})
16083 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
16084 will listen to each sensor that actually exists and ignore non-existent ones.
16085 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
16087 @item @code{server} (default: @code{'()})
16088 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
16089 @item @code{servers} (default: @code{%openntp-servers})
16090 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
16091 @item @code{constraint-from} (default: @code{'()})
16092 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
16093 This time information is not used for precision but acts as an authenticated
16094 constraint, thereby reducing the impact of unauthenticated NTP
16095 man-in-the-middle attacks.
16096 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
16098 @item @code{constraints-from} (default: @code{'()})
16099 As with constraint from, specify a list of URLs, IP addresses or hostnames of
16100 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
16101 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
16102 @item @code{allow-large-adjustment?} (default: @code{#f})
16103 Determines if @code{ntpd} is allowed to make an initial adjustment of more
16109 @deffn {Scheme variable} inetd-service-type
16110 This service runs the @command{inetd} (@pxref{inetd invocation,,,
16111 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
16112 connections on internet sockets, and lazily starts the specified server
16113 program when a connection is made on one of these sockets.
16115 The value of this service is an @code{inetd-configuration} object. The
16116 following example configures the @command{inetd} daemon to provide the
16117 built-in @command{echo} service, as well as an smtp service which
16118 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
16119 gateway @code{hostname}:
16124 (inetd-configuration
16128 (socket-type 'stream)
16135 (socket-type 'stream)
16139 (program (file-append openssh "/bin/ssh"))
16141 '("ssh" "-qT" "-i" "/path/to/ssh_key"
16142 "-W" "smtp-server:25" "user@@hostname")))))))
16145 See below for more details about @code{inetd-configuration}.
16148 @deftp {Data Type} inetd-configuration
16149 Data type representing the configuration of @command{inetd}.
16152 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
16153 The @command{inetd} executable to use.
16155 @item @code{entries} (default: @code{'()})
16156 A list of @command{inetd} service entries. Each entry should be created
16157 by the @code{inetd-entry} constructor.
16161 @deftp {Data Type} inetd-entry
16162 Data type representing an entry in the @command{inetd} configuration.
16163 Each entry corresponds to a socket where @command{inetd} will listen for
16167 @item @code{node} (default: @code{#f})
16168 Optional string, a comma-separated list of local addresses
16169 @command{inetd} should use when listening for this service.
16170 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
16171 description of all options.
16173 A string, the name must correspond to an entry in @code{/etc/services}.
16174 @item @code{socket-type}
16175 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
16177 @item @code{protocol}
16178 A string, must correspond to an entry in @code{/etc/protocols}.
16179 @item @code{wait?} (default: @code{#t})
16180 Whether @command{inetd} should wait for the server to exit before
16181 listening to new service requests.
16183 A string containing the user (and, optionally, group) name of the user
16184 as whom the server should run. The group name can be specified in a
16185 suffix, separated by a colon or period, i.e.@: @code{"user"},
16186 @code{"user:group"} or @code{"user.group"}.
16187 @item @code{program} (default: @code{"internal"})
16188 The server program which will serve the requests, or @code{"internal"}
16189 if @command{inetd} should use a built-in service.
16190 @item @code{arguments} (default: @code{'()})
16191 A list strings or file-like objects, which are the server program's
16192 arguments, starting with the zeroth argument, i.e.@: the name of the
16193 program itself. For @command{inetd}'s internal services, this entry
16194 must be @code{'()} or @code{'("internal")}.
16197 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
16198 detailed discussion of each configuration field.
16202 @defvr {Scheme Variable} tor-service-type
16203 This is the type for a service that runs the @uref{https://torproject.org,
16204 Tor} anonymous networking daemon. The service is configured using a
16205 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
16206 @code{tor} unprivileged user, which is a member of the @code{tor} group.
16210 @deftp {Data Type} tor-configuration
16212 @item @code{tor} (default: @code{tor})
16213 The package that provides the Tor daemon. This package is expected to provide
16214 the daemon at @file{bin/tor} relative to its output directory. The default
16215 package is the @uref{https://www.torproject.org, Tor Project's}
16218 @item @code{config-file} (default: @code{(plain-file "empty" "")})
16219 The configuration file to use. It will be appended to a default configuration
16220 file, and the final configuration file will be passed to @code{tor} via its
16221 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
16222 file-like objects}). See @code{man tor} for details on the configuration file
16225 @item @code{hidden-services} (default: @code{'()})
16226 The list of @code{<hidden-service>} records to use. For any hidden service
16227 you include in this list, appropriate configuration to enable the hidden
16228 service will be automatically added to the default configuration file. You
16229 may conveniently create @code{<hidden-service>} records using the
16230 @code{tor-hidden-service} procedure described below.
16232 @item @code{socks-socket-type} (default: @code{'tcp})
16233 The default socket type that Tor should use for its SOCKS socket. This must
16234 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
16235 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
16236 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
16237 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
16240 If you want to customize the SOCKS socket in more detail, leave
16241 @code{socks-socket-type} at its default value of @code{'tcp} and use
16242 @code{config-file} to override the default by providing your own
16243 @code{SocksPort} option.
16247 @cindex hidden service
16248 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
16249 Define a new Tor @dfn{hidden service} called @var{name} and implementing
16250 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
16253 '((22 "127.0.0.1:22")
16254 (80 "127.0.0.1:8080"))
16257 In this example, port 22 of the hidden service is mapped to local port 22, and
16258 port 80 is mapped to local port 8080.
16260 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
16261 the @file{hostname} file contains the @code{.onion} host name for the hidden
16264 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
16265 project's documentation} for more information.
16268 The @code{(gnu services rsync)} module provides the following services:
16270 You might want an rsync daemon if you have files that you want available
16271 so anyone (or just yourself) can download existing files or upload new
16274 @deffn {Scheme Variable} rsync-service-type
16275 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
16276 The value for this service type is a
16277 @command{rsync-configuration} record as in this example:
16280 (service rsync-service-type)
16283 See below for details about @code{rsync-configuration}.
16286 @deftp {Data Type} rsync-configuration
16287 Data type representing the configuration for @code{rsync-service}.
16290 @item @code{package} (default: @var{rsync})
16291 @code{rsync} package to use.
16293 @item @code{port-number} (default: @code{873})
16294 TCP port on which @command{rsync} listens for incoming connections. If port
16295 is less than @code{1024} @command{rsync} needs to be started as the
16296 @code{root} user and group.
16298 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
16299 Name of the file where @command{rsync} writes its PID.
16301 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
16302 Name of the file where @command{rsync} writes its lock file.
16304 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
16305 Name of the file where @command{rsync} writes its log file.
16307 @item @code{use-chroot?} (default: @var{#t})
16308 Whether to use chroot for @command{rsync} shared directory.
16310 @item @code{share-path} (default: @file{/srv/rsync})
16311 Location of the @command{rsync} shared directory.
16313 @item @code{share-comment} (default: @code{"Rsync share"})
16314 Comment of the @command{rsync} shared directory.
16316 @item @code{read-only?} (default: @var{#f})
16317 Read-write permissions to shared directory.
16319 @item @code{timeout} (default: @code{300})
16320 I/O timeout in seconds.
16322 @item @code{user} (default: @var{"root"})
16323 Owner of the @code{rsync} process.
16325 @item @code{group} (default: @var{"root"})
16326 Group of the @code{rsync} process.
16328 @item @code{uid} (default: @var{"rsyncd"})
16329 User name or user ID that file transfers to and from that module should take
16330 place as when the daemon was run as @code{root}.
16332 @item @code{gid} (default: @var{"rsyncd"})
16333 Group name or group ID that will be used when accessing the module.
16338 Furthermore, @code{(gnu services ssh)} provides the following services.
16342 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
16343 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
16344 [#:allow-empty-passwords? #f] [#:root-login? #f] @
16345 [#:syslog-output? #t] [#:x11-forwarding? #t] @
16346 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
16347 [#:public-key-authentication? #t] [#:initialize? #t]
16348 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
16349 @var{host-key} must designate a file containing the host key, and readable
16352 When @var{daemonic?} is true, @command{lshd} will detach from the
16353 controlling terminal and log its output to syslogd, unless one sets
16354 @var{syslog-output?} to false. Obviously, it also makes lsh-service
16355 depend on existence of syslogd service. When @var{pid-file?} is true,
16356 @command{lshd} writes its PID to the file called @var{pid-file}.
16358 When @var{initialize?} is true, automatically create the seed and host key
16359 upon service activation if they do not exist yet. This may take long and
16360 require interaction.
16362 When @var{initialize?} is false, it is up to the user to initialize the
16363 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
16364 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
16365 basics,,, lsh, LSH Manual}).
16367 When @var{interfaces} is empty, lshd listens for connections on all the
16368 network interfaces; otherwise, @var{interfaces} must be a list of host names
16371 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
16372 passwords, and @var{root-login?} specifies whether to accept log-ins as
16375 The other options should be self-descriptive.
16380 @deffn {Scheme Variable} openssh-service-type
16381 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
16382 shell daemon, @command{sshd}. Its value must be an
16383 @code{openssh-configuration} record as in this example:
16386 (service openssh-service-type
16387 (openssh-configuration
16388 (x11-forwarding? #t)
16389 (permit-root-login 'without-password)
16391 `(("alice" ,(local-file "alice.pub"))
16392 ("bob" ,(local-file "bob.pub"))))))
16395 See below for details about @code{openssh-configuration}.
16397 This service can be extended with extra authorized keys, as in this
16401 (service-extension openssh-service-type
16402 (const `(("charlie"
16403 ,(local-file "charlie.pub")))))
16407 @deftp {Data Type} openssh-configuration
16408 This is the configuration record for OpenSSH's @command{sshd}.
16411 @item @code{openssh} (default @var{openssh})
16412 The Openssh package to use.
16414 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
16415 Name of the file where @command{sshd} writes its PID.
16417 @item @code{port-number} (default: @code{22})
16418 TCP port on which @command{sshd} listens for incoming connections.
16420 @item @code{permit-root-login} (default: @code{#f})
16421 This field determines whether and when to allow logins as root. If
16422 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
16423 If it's the symbol @code{'without-password}, then root logins are
16424 permitted but not with password-based authentication.
16426 @item @code{allow-empty-passwords?} (default: @code{#f})
16427 When true, users with empty passwords may log in. When false, they may
16430 @item @code{password-authentication?} (default: @code{#t})
16431 When true, users may log in with their password. When false, they have
16432 other authentication methods.
16434 @item @code{public-key-authentication?} (default: @code{#t})
16435 When true, users may log in using public key authentication. When
16436 false, users have to use other authentication method.
16438 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
16439 This is used only by protocol version 2.
16441 @item @code{x11-forwarding?} (default: @code{#f})
16442 When true, forwarding of X11 graphical client connections is
16443 enabled---in other words, @command{ssh} options @option{-X} and
16444 @option{-Y} will work.
16446 @item @code{allow-agent-forwarding?} (default: @code{#t})
16447 Whether to allow agent forwarding.
16449 @item @code{allow-tcp-forwarding?} (default: @code{#t})
16450 Whether to allow TCP forwarding.
16452 @item @code{gateway-ports?} (default: @code{#f})
16453 Whether to allow gateway ports.
16455 @item @code{challenge-response-authentication?} (default: @code{#f})
16456 Specifies whether challenge response authentication is allowed (e.g.@: via
16459 @item @code{use-pam?} (default: @code{#t})
16460 Enables the Pluggable Authentication Module interface. If set to
16461 @code{#t}, this will enable PAM authentication using
16462 @code{challenge-response-authentication?} and
16463 @code{password-authentication?}, in addition to PAM account and session
16464 module processing for all authentication types.
16466 Because PAM challenge response authentication usually serves an
16467 equivalent role to password authentication, you should disable either
16468 @code{challenge-response-authentication?} or
16469 @code{password-authentication?}.
16471 @item @code{print-last-log?} (default: @code{#t})
16472 Specifies whether @command{sshd} should print the date and time of the
16473 last user login when a user logs in interactively.
16475 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
16476 Configures external subsystems (e.g.@: file transfer daemon).
16478 This is a list of two-element lists, each of which containing the
16479 subsystem name and a command (with optional arguments) to execute upon
16482 The command @command{internal-sftp} implements an in-process SFTP
16483 server. Alternatively, one can specify the @command{sftp-server} command:
16485 (service openssh-service-type
16486 (openssh-configuration
16488 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
16491 @item @code{accepted-environment} (default: @code{'()})
16492 List of strings describing which environment variables may be exported.
16494 Each string gets on its own line. See the @code{AcceptEnv} option in
16495 @code{man sshd_config}.
16497 This example allows ssh-clients to export the @env{COLORTERM} variable.
16498 It is set by terminal emulators, which support colors. You can use it in
16499 your shell's resource file to enable colors for the prompt and commands
16500 if this variable is set.
16503 (service openssh-service-type
16504 (openssh-configuration
16505 (accepted-environment '("COLORTERM"))))
16508 @item @code{authorized-keys} (default: @code{'()})
16509 @cindex authorized keys, SSH
16510 @cindex SSH authorized keys
16511 This is the list of authorized keys. Each element of the list is a user
16512 name followed by one or more file-like objects that represent SSH public
16516 (openssh-configuration
16518 `(("rekado" ,(local-file "rekado.pub"))
16519 ("chris" ,(local-file "chris.pub"))
16520 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
16524 registers the specified public keys for user accounts @code{rekado},
16525 @code{chris}, and @code{root}.
16527 Additional authorized keys can be specified @i{via}
16528 @code{service-extension}.
16530 Note that this does @emph{not} interfere with the use of
16531 @file{~/.ssh/authorized_keys}.
16533 @item @code{log-level} (default: @code{'info})
16534 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
16535 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
16536 page for @file{sshd_config} for the full list of level names.
16538 @item @code{extra-content} (default: @code{""})
16539 This field can be used to append arbitrary text to the configuration file. It
16540 is especially useful for elaborate configurations that cannot be expressed
16541 otherwise. This configuration, for example, would generally disable root
16542 logins, but permit them from one specific IP address:
16545 (openssh-configuration
16547 Match Address 192.168.0.1
16548 PermitRootLogin yes"))
16554 @deffn {Scheme Procedure} dropbear-service [@var{config}]
16555 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
16556 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
16559 For example, to specify a Dropbear service listening on port 1234, add
16560 this call to the operating system's @code{services} field:
16563 (dropbear-service (dropbear-configuration
16564 (port-number 1234)))
16568 @deftp {Data Type} dropbear-configuration
16569 This data type represents the configuration of a Dropbear SSH daemon.
16572 @item @code{dropbear} (default: @var{dropbear})
16573 The Dropbear package to use.
16575 @item @code{port-number} (default: 22)
16576 The TCP port where the daemon waits for incoming connections.
16578 @item @code{syslog-output?} (default: @code{#t})
16579 Whether to enable syslog output.
16581 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
16582 File name of the daemon's PID file.
16584 @item @code{root-login?} (default: @code{#f})
16585 Whether to allow @code{root} logins.
16587 @item @code{allow-empty-passwords?} (default: @code{#f})
16588 Whether to allow empty passwords.
16590 @item @code{password-authentication?} (default: @code{#t})
16591 Whether to enable password-based authentication.
16596 @deffn {Scheme Variable} autossh-service-type
16597 This is the type for the @uref{https://www.harding.motd.ca/autossh,
16598 AutoSSH} program that runs a copy of @command{ssh} and monitors it,
16599 restarting it as necessary should it die or stop passing traffic.
16600 AutoSSH can be run manually from the command-line by passing arguments
16601 to the binary @command{autossh} from the package @code{autossh}, but it
16602 can also be run as a Guix service. This latter use case is documented
16605 AutoSSH can be used to forward local traffic to a remote machine using
16606 an SSH tunnel, and it respects the @file{~/.ssh/config} of the user it
16609 For example, to specify a service running autossh as the user
16610 @code{pino} and forwarding all local connections to port @code{8081} to
16611 @code{remote:8081} using an SSH tunnel, add this call to the operating
16612 system's @code{services} field:
16615 (service autossh-service-type
16616 (autossh-configuration
16618 (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
16622 @deftp {Data Type} autossh-configuration
16623 This data type represents the configuration of an AutoSSH service.
16627 @item @code{user} (default @code{"autossh"})
16628 The user as which the AutoSSH service is to be run.
16629 This assumes that the specified user exists.
16631 @item @code{poll} (default @code{600})
16632 Specifies the connection poll time in seconds.
16634 @item @code{first-poll} (default @code{#f})
16635 Specifies how many seconds AutoSSH waits before the first connection
16636 test. After this first test, polling is resumed at the pace defined in
16637 @code{poll}. When set to @code{#f}, the first poll is not treated
16638 specially and will also use the connection poll specified in
16641 @item @code{gate-time} (default @code{30})
16642 Specifies how many seconds an SSH connection must be active before it is
16643 considered successful.
16645 @item @code{log-level} (default @code{1})
16646 The log level, corresponding to the levels used by syslog---so @code{0}
16647 is the most silent while @code{7} is the chattiest.
16649 @item @code{max-start} (default @code{#f})
16650 The maximum number of times SSH may be (re)started before AutoSSH exits.
16651 When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
16653 @item @code{message} (default @code{""})
16654 The message to append to the echo message sent when testing connections.
16656 @item @code{port} (default @code{"0"})
16657 The ports used for monitoring the connection. When set to @code{"0"},
16658 monitoring is disabled. When set to @code{"@var{n}"} where @var{n} is
16659 a positive integer, ports @var{n} and @var{n}+1 are used for
16660 monitoring the connection, such that port @var{n} is the base
16661 monitoring port and @code{n+1} is the echo port. When set to
16662 @code{"@var{n}:@var{m}"} where @var{n} and @var{m} are positive
16663 integers, the ports @var{n} and @var{m} are used for monitoring the
16664 connection, such that port @var{n} is the base monitoring port and
16665 @var{m} is the echo port.
16667 @item @code{ssh-options} (default @code{'()})
16668 The list of command-line arguments to pass to @command{ssh} when it is
16669 run. Options @option{-f} and @option{-M} are reserved for AutoSSH and
16670 may cause undefined behaviour.
16676 @deffn {Scheme Variable} webssh-service-type
16677 This is the type for the @uref{https://webssh.huashengdun.org/, WebSSH}
16678 program that runs a web SSH client. WebSSH can be run manually from the
16679 command-line by passing arguments to the binary @command{wssh} from the
16680 package @code{webssh}, but it can also be run as a Guix service. This
16681 latter use case is documented here.
16683 For example, to specify a service running WebSSH on loopback interface
16684 on port @code{8888} with reject policy with a list of allowed to
16685 connection hosts, and NGINX as a reverse-proxy to this service listening
16686 for HTTPS connection, add this call to the operating system's
16687 @code{services} field:
16690 (service webssh-service-type
16691 (webssh-configuration (address "127.0.0.1")
16694 (known-hosts '("localhost ecdsa-sha2-nistp256 AAAA…"
16695 "127.0.0.1 ecdsa-sha2-nistp256 AAAA…"))))
16697 (service nginx-service-type
16698 (nginx-configuration
16701 (nginx-server-configuration
16702 (inherit %webssh-configuration-nginx)
16703 (server-name '("webssh.example.com"))
16704 (listen '("443 ssl"))
16705 (ssl-certificate (letsencrypt-certificate "webssh.example.com"))
16706 (ssl-certificate-key (letsencrypt-key "webssh.example.com"))
16708 (cons (nginx-location-configuration
16709 (uri "/.well-known")
16710 (body '("root /var/www;")))
16711 (nginx-server-configuration-locations %webssh-configuration-nginx))))))))
16715 @deftp {Data Type} webssh-configuration
16716 Data type representing the configuration for @code{webssh-service}.
16719 @item @code{package} (default: @var{webssh})
16720 @code{webssh} package to use.
16722 @item @code{user-name} (default: @var{"webssh"})
16723 User name or user ID that file transfers to and from that module should take
16726 @item @code{group-name} (default: @var{"webssh"})
16727 Group name or group ID that will be used when accessing the module.
16729 @item @code{address} (default: @var{#f})
16730 IP address on which @command{webssh} listens for incoming connections.
16732 @item @code{port} (default: @var{8888})
16733 TCP port on which @command{webssh} listens for incoming connections.
16735 @item @code{policy} (default: @var{#f})
16736 Connection policy. @var{reject} policy requires to specify @var{known-hosts}.
16738 @item @code{known-hosts} (default: @var{'()})
16739 List of hosts which allowed for SSH connection from @command{webssh}.
16741 @item @code{log-file} (default: @file{"/var/log/webssh.log"})
16742 Name of the file where @command{webssh} writes its log file.
16744 @item @code{log-level} (default: @var{#f})
16750 @defvr {Scheme Variable} %facebook-host-aliases
16751 This variable contains a string for use in @file{/etc/hosts}
16752 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
16753 line contains a entry that maps a known server name of the Facebook
16754 on-line service---e.g., @code{www.facebook.com}---to the local
16755 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
16757 This variable is typically used in the @code{hosts-file} field of an
16758 @code{operating-system} declaration (@pxref{operating-system Reference,
16759 @file{/etc/hosts}}):
16762 (use-modules (gnu) (guix))
16765 (host-name "mymachine")
16768 ;; Create a /etc/hosts file with aliases for "localhost"
16769 ;; and "mymachine", as well as for Facebook servers.
16770 (plain-file "hosts"
16771 (string-append (local-host-aliases host-name)
16772 %facebook-host-aliases))))
16775 This mechanism can prevent programs running locally, such as Web
16776 browsers, from accessing Facebook.
16779 The @code{(gnu services avahi)} provides the following definition.
16781 @defvr {Scheme Variable} avahi-service-type
16782 This is the service that runs @command{avahi-daemon}, a system-wide
16783 mDNS/DNS-SD responder that allows for service discovery and
16784 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
16785 Its value must be an @code{avahi-configuration} record---see below.
16787 This service extends the name service cache daemon (nscd) so that it can
16788 resolve @code{.local} host names using
16789 @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
16790 Service Switch}, for information on host name resolution.
16792 Additionally, add the @var{avahi} package to the system profile so that
16793 commands such as @command{avahi-browse} are directly usable.
16796 @deftp {Data Type} avahi-configuration
16797 Data type representation the configuration for Avahi.
16801 @item @code{host-name} (default: @code{#f})
16802 If different from @code{#f}, use that as the host name to
16803 publish for this machine; otherwise, use the machine's actual host name.
16805 @item @code{publish?} (default: @code{#t})
16806 When true, allow host names and services to be published (broadcast) over the
16809 @item @code{publish-workstation?} (default: @code{#t})
16810 When true, @command{avahi-daemon} publishes the machine's host name and IP
16811 address via mDNS on the local network. To view the host names published on
16812 your local network, you can run:
16815 avahi-browse _workstation._tcp
16818 @item @code{wide-area?} (default: @code{#f})
16819 When true, DNS-SD over unicast DNS is enabled.
16821 @item @code{ipv4?} (default: @code{#t})
16822 @itemx @code{ipv6?} (default: @code{#t})
16823 These fields determine whether to use IPv4/IPv6 sockets.
16825 @item @code{domains-to-browse} (default: @code{'()})
16826 This is a list of domains to browse.
16830 @deffn {Scheme Variable} openvswitch-service-type
16831 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
16832 service, whose value should be an @code{openvswitch-configuration}
16836 @deftp {Data Type} openvswitch-configuration
16837 Data type representing the configuration of Open vSwitch, a multilayer
16838 virtual switch which is designed to enable massive network automation
16839 through programmatic extension.
16842 @item @code{package} (default: @var{openvswitch})
16843 Package object of the Open vSwitch.
16848 @defvr {Scheme Variable} pagekite-service-type
16849 This is the service type for the @uref{https://pagekite.net, PageKite} service,
16850 a tunneling solution for making localhost servers publicly visible, even from
16851 behind restrictive firewalls or NAT without forwarded ports. The value for
16852 this service type is a @code{pagekite-configuration} record.
16854 Here's an example exposing the local HTTP and SSH daemons:
16857 (service pagekite-service-type
16858 (pagekite-configuration
16859 (kites '("http:@@kitename:localhost:80:@@kitesecret"
16860 "raw/22:@@kitename:localhost:22:@@kitesecret"))
16861 (extra-file "/etc/pagekite.rc")))
16865 @deftp {Data Type} pagekite-configuration
16866 Data type representing the configuration of PageKite.
16869 @item @code{package} (default: @var{pagekite})
16870 Package object of PageKite.
16872 @item @code{kitename} (default: @code{#f})
16873 PageKite name for authenticating to the frontend server.
16875 @item @code{kitesecret} (default: @code{#f})
16876 Shared secret for authenticating to the frontend server. You should probably
16877 put this inside @code{extra-file} instead.
16879 @item @code{frontend} (default: @code{#f})
16880 Connect to the named PageKite frontend server instead of the
16881 @uref{https://pagekite.net,,pagekite.net} service.
16883 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
16884 List of service kites to use. Exposes HTTP on port 80 by default. The format
16885 is @code{proto:kitename:host:port:secret}.
16887 @item @code{extra-file} (default: @code{#f})
16888 Extra configuration file to read, which you are expected to create manually.
16889 Use this to add additional options and manage shared secrets out-of-band.
16894 @defvr {Scheme Variable} yggdrasil-service-type
16895 The service type for connecting to the @uref{https://yggdrasil-network.github.io/,
16896 Yggdrasil network}, an early-stage implementation of a fully end-to-end
16897 encrypted IPv6 network.
16900 Yggdrasil provides name-independent routing with cryptographically generated
16901 addresses. Static addressing means you can keep the same address as long as
16902 you want, even if you move to a new location, or generate a new address (by
16903 generating new keys) whenever you want.
16904 @uref{https://yggdrasil-network.github.io/2018/07/28/addressing.html}
16907 Pass it a value of @code{yggdrasil-configuration} to connect it to public
16908 peers and/or local peers.
16910 Here is an example using public peers and a static address. The static
16911 signing and encryption keys are defined in @file{/etc/yggdrasil-private.conf}
16912 (the default value for @code{config-file}).
16915 ;; part of the operating-system declaration
16916 (service yggdrasil-service-type
16917 (yggdrasil-configuration
16918 (autoconf? #f) ;; use only the public peers
16921 ;; https://github.com/yggdrasil-network/public-peers
16922 '((peers . #("tcp://1.2.3.4:1337"))))
16923 ;; /etc/yggdrasil-private.conf is the default value for config-file
16927 # sample content for /etc/yggdrasil-private.conf
16929 # Your public encryption key. Your peers may ask you for this to put
16930 # into their AllowedEncryptionPublicKeys configuration.
16931 EncryptionPublicKey: 378dc5...
16933 # Your private encryption key. DO NOT share this with anyone!
16934 EncryptionPrivateKey: 0777...
16936 # Your public signing key. You should not ordinarily need to share
16937 # this with anyone.
16938 SigningPublicKey: e1664...
16940 # Your private signing key. DO NOT share this with anyone!
16941 SigningPrivateKey: 0589d...
16946 @deftp {Data Type} yggdrasil-configuration
16947 Data type representing the configuration of Yggdrasil.
16950 @item @code{package} (default: @code{yggdrasil})
16951 Package object of Yggdrasil.
16953 @item @code{json-config} (default: @code{'()})
16954 Contents of @file{/etc/yggdrasil.conf}. Will be merged with
16955 @file{/etc/yggdrasil-private.conf}. Note that these settings are stored in
16956 the Guix store, which is readable to all users. @strong{Do not store your
16957 private keys in it}. See the output of @code{yggdrasil -genconf} for a
16958 quick overview of valid keys and their default values.
16960 @item @code{autoconf?} (default: @code{#f})
16961 Whether to use automatic mode. Enabling it makes Yggdrasil use adynamic IP
16962 and peer with IPv6 neighbors.
16964 @item @code{log-level} (default: @code{'info})
16965 How much detail to include in logs. Use @code{'debug} for more detail.
16967 @item @code{log-to} (default: @code{'stdout})
16968 Where to send logs. By default, the service logs standard output to
16969 @file{/var/log/yggdrasil.log}. The alternative is @code{'syslog}, which
16970 sends output to the running syslog service.
16972 @item @code{config-file} (default: @code{"/etc/yggdrasil-private.conf"})
16973 What HJSON file to load sensitive data from. This is where private keys
16974 should be stored, which are necessary to specify if you don't want a
16975 randomized address after each restart. Use @code{#f} to disable. Options
16976 defined in this file take precedence over @code{json-config}. Use the output
16977 of @code{yggdrasil -genconf} as a starting point. To configure a static
16978 address, delete everything except these options:
16981 @item @code{EncryptionPublicKey}
16982 @item @code{EncryptionPrivateKey}
16983 @item @code{SigningPublicKey}
16984 @item @code{SigningPrivateKey}
16989 @node Unattended Upgrades
16990 @subsection Unattended Upgrades
16992 @cindex unattended upgrades
16993 @cindex upgrades, unattended
16994 Guix provides a service to perform @emph{unattended upgrades}:
16995 periodically, the system automatically reconfigures itself from the
16996 latest Guix. Guix System has several properties that make unattended
17001 upgrades are transactional (either the upgrade succeeds or it fails, but
17002 you cannot end up with an ``in-between'' system state);
17004 the upgrade log is kept---you can view it with @command{guix system
17005 list-generations}---and you can roll back to any previous generation,
17006 should the upgraded system fail to behave as intended;
17008 channel code is authenticated so you know you can only run genuine code
17009 (@pxref{Channels});
17011 @command{guix system reconfigure} prevents downgrades, which makes it
17012 immune to @dfn{downgrade attacks}.
17015 To set up unattended upgrades, add an instance of
17016 @code{unattended-upgrade-service-type} like the one below to the list of
17017 your operating system services:
17020 (service unattended-upgrade-service-type)
17023 The defaults above set up weekly upgrades: every Sunday at midnight.
17024 You do not need to provide the operating system configuration file: it
17025 uses @file{/run/current-system/configuration.scm}, which ensures it
17026 always uses your latest configuration---@pxref{provenance-service-type},
17027 for more information about this file.
17029 There are several things that can be configured, in particular the
17030 periodicity and services (daemons) to be restarted upon completion.
17031 When the upgrade is successful, the service takes care of deleting
17032 system generations older that some threshold, as per @command{guix
17033 system delete-generations}. See the reference below for details.
17035 To ensure that upgrades are actually happening, you can run
17036 @command{guix system describe}. To investigate upgrade failures, visit
17037 the unattended upgrade log file (see below).
17039 @defvr {Scheme Variable} unattended-upgrade-service-type
17040 This is the service type for unattended upgrades. It sets up an mcron
17041 job (@pxref{Scheduled Job Execution}) that runs @command{guix system
17042 reconfigure} from the latest version of the specified channels.
17044 Its value must be a @code{unattended-upgrade-configuration} record (see
17048 @deftp {Data Type} unattended-upgrade-configuration
17049 This data type represents the configuration of the unattended upgrade
17050 service. The following fields are available:
17053 @item @code{schedule} (default: @code{"30 01 * * 0"})
17054 This is the schedule of upgrades, expressed as a gexp containing an
17055 mcron job schedule (@pxref{Guile Syntax, mcron job specifications,,
17056 mcron, GNU@tie{}mcron}).
17058 @item @code{channels} (default: @code{#~%default-channels})
17059 This gexp specifies the channels to use for the upgrade
17060 (@pxref{Channels}). By default, the tip of the official @code{guix}
17063 @item @code{operating-system-file} (default: @code{"/run/current-system/configuration.scm"})
17064 This field specifies the operating system configuration file to use.
17065 The default is to reuse the config file of the current configuration.
17067 There are cases, though, where referring to
17068 @file{/run/current-system/configuration.scm} is not enough, for instance
17069 because that file refers to extra files (SSH public keys, extra
17070 configuration files, etc.) @i{via} @code{local-file} and similar
17071 constructs. For those cases, we recommend something along these lines:
17074 (unattended-upgrade-configuration
17075 (operating-system-file
17076 (file-append (local-file "." "config-dir" #:recursive? #t)
17080 The effect here is to import all of the current directory into the
17081 store, and to refer to @file{config.scm} within that directory.
17082 Therefore, uses of @code{local-file} within @file{config.scm} will work
17083 as expected. @xref{G-Expressions}, for information about
17084 @code{local-file} and @code{file-append}.
17086 @item @code{services-to-restart} (default: @code{'(mcron)})
17087 This field specifies the Shepherd services to restart when the upgrade
17090 Those services are restarted right away upon completion, as with
17091 @command{herd restart}, which ensures that the latest version is
17092 running---remember that by default @command{guix system reconfigure}
17093 only restarts services that are not currently running, which is
17094 conservative: it minimizes disruption but leaves outdated services
17097 By default, the @code{mcron} service is restarted. This ensures that
17098 the latest version of the unattended upgrade job will be used next time.
17100 @item @code{system-expiration} (default: @code{(* 3 30 24 3600)})
17101 This is the expiration time in seconds for system generations. System
17102 generations older that this amount of time are deleted with
17103 @command{guix system delete-generations} when an upgrade completes.
17106 The unattended upgrade service does not run the garbage collector. You
17107 will probably want to set up your own mcron job to run @command{guix gc}
17111 @item @code{maximum-duration} (default: @code{3600})
17112 Maximum duration in seconds for the upgrade; past that time, the upgrade
17115 This is primarily useful to ensure the upgrade does not end up
17116 rebuilding or re-downloading ``the world''.
17118 @item @code{log-file} (default: @code{"/var/log/unattended-upgrade.log"})
17119 File where unattended upgrades are logged.
17124 @subsection X Window
17127 @cindex X Window System
17128 @cindex login manager
17129 Support for the X Window graphical display system---specifically
17130 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
17131 there is no @code{xorg-service} procedure. Instead, the X server is
17132 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
17135 @cindex GNOME, login manager
17136 GDM of course allows users to log in into window managers and desktop
17137 environments other than GNOME; for those using GNOME, GDM is required for
17138 features such as automatic screen locking.
17140 @cindex window manager
17141 To use X11, you must install at least one @dfn{window manager}---for
17142 example the @code{windowmaker} or @code{openbox} packages---preferably
17143 by adding it to the @code{packages} field of your operating system
17144 definition (@pxref{operating-system Reference, system-wide packages}).
17146 @defvr {Scheme Variable} gdm-service-type
17147 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
17148 Desktop Manager} (GDM), a program that manages graphical display servers and
17149 handles graphical user logins. Its value must be a @code{gdm-configuration}
17152 @cindex session types (X11)
17153 @cindex X11 session types
17154 GDM looks for @dfn{session types} described by the @file{.desktop} files in
17155 @file{/run/current-system/profile/share/xsessions} and allows users to choose
17156 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
17157 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
17158 set of packages automatically makes them available at the log-in screen.
17160 In addition, @file{~/.xsession} files are honored. When available,
17161 @file{~/.xsession} must be an executable that starts a window manager
17162 and/or other X clients.
17165 @deftp {Data Type} gdm-configuration
17167 @item @code{auto-login?} (default: @code{#f})
17168 @itemx @code{default-user} (default: @code{#f})
17169 When @code{auto-login?} is false, GDM presents a log-in screen.
17171 When @code{auto-login?} is true, GDM logs in directly as
17172 @code{default-user}.
17174 @item @code{debug?} (default: @code{#f})
17175 When true, GDM writes debug messages to its log.
17177 @item @code{gnome-shell-assets} (default: ...)
17178 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
17180 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
17181 Configuration of the Xorg graphical server.
17183 @item @code{xsession} (default: @code{(xinitrc)})
17184 Script to run before starting a X session.
17186 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
17187 File name of the @code{dbus-daemon} executable.
17189 @item @code{gdm} (default: @code{gdm})
17190 The GDM package to use.
17194 @defvr {Scheme Variable} slim-service-type
17195 This is the type for the SLiM graphical login manager for X11.
17197 Like GDM, SLiM looks for session types described by @file{.desktop} files and
17198 allows users to choose a session from the log-in screen using @kbd{F1}. It
17199 also honors @file{~/.xsession} files.
17201 Unlike GDM, SLiM does not spawn the user session on a different VT after
17202 logging in, which means that you can only start one graphical session. If you
17203 want to be able to run multiple graphical sessions at the same time you have
17204 to add multiple SLiM services to your system services. The following example
17205 shows how to replace the default GDM service with two SLiM services on tty7
17209 (use-modules (gnu services)
17210 (gnu services desktop)
17211 (gnu services xorg)
17212 (srfi srfi-1)) ;for 'remove'
17216 (services (cons* (service slim-service-type (slim-configuration
17219 (service slim-service-type (slim-configuration
17222 (remove (lambda (service)
17223 (eq? (service-kind service) gdm-service-type))
17224 %desktop-services))))
17229 @deftp {Data Type} slim-configuration
17230 Data type representing the configuration of @code{slim-service-type}.
17233 @item @code{allow-empty-passwords?} (default: @code{#t})
17234 Whether to allow logins with empty passwords.
17236 @item @code{auto-login?} (default: @code{#f})
17237 @itemx @code{default-user} (default: @code{""})
17238 When @code{auto-login?} is false, SLiM presents a log-in screen.
17240 When @code{auto-login?} is true, SLiM logs in directly as
17241 @code{default-user}.
17243 @item @code{theme} (default: @code{%default-slim-theme})
17244 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
17245 The graphical theme to use and its name.
17247 @item @code{auto-login-session} (default: @code{#f})
17248 If true, this must be the name of the executable to start as the default
17249 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
17251 If false, a session described by one of the available @file{.desktop}
17252 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
17256 You must install at least one window manager in the system profile or in
17257 your user profile. Failing to do that, if @code{auto-login-session} is
17258 false, you will be unable to log in.
17261 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
17262 Configuration of the Xorg graphical server.
17264 @item @code{display} (default @code{":0"})
17265 The display on which to start the Xorg graphical server.
17267 @item @code{vt} (default @code{"vt7"})
17268 The VT on which to start the Xorg graphical server.
17270 @item @code{xauth} (default: @code{xauth})
17271 The XAuth package to use.
17273 @item @code{shepherd} (default: @code{shepherd})
17274 The Shepherd package used when invoking @command{halt} and
17277 @item @code{sessreg} (default: @code{sessreg})
17278 The sessreg package used in order to register the session.
17280 @item @code{slim} (default: @code{slim})
17281 The SLiM package to use.
17285 @defvr {Scheme Variable} %default-theme
17286 @defvrx {Scheme Variable} %default-theme-name
17287 The default SLiM theme and its name.
17291 @deftp {Data Type} sddm-configuration
17292 This is the data type representing the SDDM service configuration.
17295 @item @code{display-server} (default: "x11")
17296 Select display server to use for the greeter. Valid values are
17297 @samp{"x11"} or @samp{"wayland"}.
17299 @item @code{numlock} (default: "on")
17300 Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
17302 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
17303 Command to run when halting.
17305 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
17306 Command to run when rebooting.
17308 @item @code{theme} (default "maldives")
17309 Theme to use. Default themes provided by SDDM are @samp{"elarun"},
17310 @samp{"maldives"} or @samp{"maya"}.
17312 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
17313 Directory to look for themes.
17315 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
17316 Directory to look for faces.
17318 @item @code{default-path} (default "/run/current-system/profile/bin")
17319 Default PATH to use.
17321 @item @code{minimum-uid} (default: 1000)
17322 Minimum UID displayed in SDDM and allowed for log-in.
17324 @item @code{maximum-uid} (default: 2000)
17325 Maximum UID to display in SDDM.
17327 @item @code{remember-last-user?} (default #t)
17328 Remember last user.
17330 @item @code{remember-last-session?} (default #t)
17331 Remember last session.
17333 @item @code{hide-users} (default "")
17334 Usernames to hide from SDDM greeter.
17336 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
17337 Users with shells listed will be hidden from the SDDM greeter.
17339 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
17340 Script to run before starting a wayland session.
17342 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
17343 Directory to look for desktop files starting wayland sessions.
17345 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
17346 Configuration of the Xorg graphical server.
17348 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
17351 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
17354 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
17355 Script to run after starting xorg-server.
17357 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
17358 Script to run before stopping xorg-server.
17360 @item @code{xsession-command} (default: @code{xinitrc})
17361 Script to run before starting a X session.
17363 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
17364 Directory to look for desktop files starting X sessions.
17366 @item @code{minimum-vt} (default: 7)
17369 @item @code{auto-login-user} (default "")
17370 User to use for auto-login.
17372 @item @code{auto-login-session} (default "")
17373 Desktop file to use for auto-login.
17375 @item @code{relogin?} (default #f)
17376 Relogin after logout.
17381 @cindex login manager
17383 @defvr {Scheme Variable} sddm-service-type
17384 This is the type of the service to run the
17385 @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
17386 must be a @code{sddm-configuration} record (see below).
17388 Here's an example use:
17391 (service sddm-service-type
17392 (sddm-configuration
17393 (auto-login-user "alice")
17394 (auto-login-session "xfce.desktop")))
17398 @deftp {Data Type} sddm-configuration
17399 This data type represents the configuration of the SDDM login manager.
17400 The available fields are:
17403 @item @code{sddm} (default: @code{sddm})
17404 The SDDM package to use.
17406 @item @code{display-server} (default: @code{"x11"})
17407 This must be either @code{"x11"} or @code{"wayland"}.
17409 @c FIXME: Add more fields.
17411 @item @code{auto-login-user} (default: @code{""})
17412 If non-empty, this is the user account under which to log in
17415 @item @code{auto-login-session} (default: @code{""})
17416 If non-empty, this is the @file{.desktop} file name to use as the
17417 auto-login session.
17421 @cindex Xorg, configuration
17422 @deftp {Data Type} xorg-configuration
17423 This data type represents the configuration of the Xorg graphical display
17424 server. Note that there is no Xorg service; instead, the X server is started
17425 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
17426 of these display managers aggregates an @code{xorg-configuration} record.
17429 @item @code{modules} (default: @code{%default-xorg-modules})
17430 This is a list of @dfn{module packages} loaded by the Xorg
17431 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
17433 @item @code{fonts} (default: @code{%default-xorg-fonts})
17434 This is a list of font directories to add to the server's @dfn{font path}.
17436 @item @code{drivers} (default: @code{'()})
17437 This must be either the empty list, in which case Xorg chooses a graphics
17438 driver automatically, or a list of driver names that will be tried in this
17439 order---e.g., @code{("modesetting" "vesa")}.
17441 @item @code{resolutions} (default: @code{'()})
17442 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
17443 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
17446 @cindex keyboard layout, for Xorg
17447 @cindex keymap, for Xorg
17448 @item @code{keyboard-layout} (default: @code{#f})
17449 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
17450 English (``qwerty'') for a 105-key PC keyboard.
17452 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
17453 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
17454 information on how to specify the keyboard layout.
17456 @item @code{extra-config} (default: @code{'()})
17457 This is a list of strings or objects appended to the configuration file. It
17458 is used to pass extra text to be added verbatim to the configuration file.
17460 @item @code{server} (default: @code{xorg-server})
17461 This is the package providing the Xorg server.
17463 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
17464 This is the list of command-line arguments to pass to the X server. The
17465 default is @code{-nolisten tcp}.
17469 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
17470 [@var{login-manager-service-type}]
17471 Tell the log-in manager (of type @var{login-manager-service-type}) to use
17472 @var{config}, an @code{<xorg-configuration>} record.
17474 Since the Xorg configuration is embedded in the log-in manager's
17475 configuration---e.g., @code{gdm-configuration}---this procedure provides a
17476 shorthand to set the Xorg configuration.
17479 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
17480 Return a @code{startx} script in which the modules, fonts, etc. specified
17481 in @var{config}, are available. The result should be used in place of
17484 Usually the X server is started by a login manager.
17488 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
17489 Add @var{package}, a package for a screen locker or screen saver whose
17490 command is @var{program}, to the set of setuid programs and add a PAM entry
17491 for it. For example:
17494 (screen-locker-service xlockmore "xlock")
17497 makes the good ol' XlockMore usable.
17501 @node Printing Services
17502 @subsection Printing Services
17504 @cindex printer support with CUPS
17505 The @code{(gnu services cups)} module provides a Guix service definition
17506 for the CUPS printing service. To add printer support to a Guix
17507 system, add a @code{cups-service} to the operating system definition:
17509 @deffn {Scheme Variable} cups-service-type
17510 The service type for the CUPS print server. Its value should be a valid
17511 CUPS configuration (see below). To use the default settings, simply
17514 (service cups-service-type)
17518 The CUPS configuration controls the basic things about your CUPS
17519 installation: what interfaces it listens on, what to do if a print job
17520 fails, how much logging to do, and so on. To actually add a printer,
17521 you have to visit the @url{http://localhost:631} URL, or use a tool such
17522 as GNOME's printer configuration services. By default, configuring a
17523 CUPS service will generate a self-signed certificate if needed, for
17524 secure connections to the print server.
17526 Suppose you want to enable the Web interface of CUPS and also add
17527 support for Epson printers @i{via} the @code{epson-inkjet-printer-escpr}
17528 package and for HP printers @i{via} the @code{hplip-minimal} package.
17529 You can do that directly, like this (you need to use the
17530 @code{(gnu packages cups)} module):
17533 (service cups-service-type
17534 (cups-configuration
17535 (web-interface? #t)
17537 (list cups-filters epson-inkjet-printer-escpr hplip-minimal))))
17540 Note: If you wish to use the Qt5 based GUI which comes with the hplip
17541 package then it is suggested that you install the @code{hplip} package,
17542 either in your OS configuration file or as your user.
17544 The available configuration parameters follow. Each parameter
17545 definition is preceded by its type; for example, @samp{string-list foo}
17546 indicates that the @code{foo} parameter should be specified as a list of
17547 strings. There is also a way to specify the configuration as a string,
17548 if you have an old @code{cupsd.conf} file that you want to port over
17549 from some other system; see the end for more details.
17551 @c The following documentation was initially generated by
17552 @c (generate-documentation) in (gnu services cups). Manually maintained
17553 @c documentation is better, so we shouldn't hesitate to edit below as
17554 @c needed. However if the change you want to make to this documentation
17555 @c can be done in an automated way, it's probably easier to change
17556 @c (generate-documentation) than to make it below and have to deal with
17557 @c the churn as CUPS updates.
17560 Available @code{cups-configuration} fields are:
17562 @deftypevr {@code{cups-configuration} parameter} package cups
17566 @deftypevr {@code{cups-configuration} parameter} package-list extensions (default: @code{(list epson-inkjet-printer-escpr hplip-minimal foomatic-filters splix)})
17567 Drivers and other extensions to the CUPS package.
17570 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
17571 Configuration of where to write logs, what directories to use for print
17572 spools, and related privileged configuration parameters.
17574 Available @code{files-configuration} fields are:
17576 @deftypevr {@code{files-configuration} parameter} log-location access-log
17577 Defines the access log filename. Specifying a blank filename disables
17578 access log generation. The value @code{stderr} causes log entries to be
17579 sent to the standard error file when the scheduler is running in the
17580 foreground, or to the system log daemon when run in the background. The
17581 value @code{syslog} causes log entries to be sent to the system log
17582 daemon. The server name may be included in filenames using the string
17583 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
17585 Defaults to @samp{"/var/log/cups/access_log"}.
17588 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
17589 Where CUPS should cache data.
17591 Defaults to @samp{"/var/cache/cups"}.
17594 @deftypevr {@code{files-configuration} parameter} string config-file-perm
17595 Specifies the permissions for all configuration files that the scheduler
17598 Note that the permissions for the printers.conf file are currently
17599 masked to only allow access from the scheduler user (typically root).
17600 This is done because printer device URIs sometimes contain sensitive
17601 authentication information that should not be generally known on the
17602 system. There is no way to disable this security feature.
17604 Defaults to @samp{"0640"}.
17607 @deftypevr {@code{files-configuration} parameter} log-location error-log
17608 Defines the error log filename. Specifying a blank filename disables
17609 error log generation. The value @code{stderr} causes log entries to be
17610 sent to the standard error file when the scheduler is running in the
17611 foreground, or to the system log daemon when run in the background. The
17612 value @code{syslog} causes log entries to be sent to the system log
17613 daemon. The server name may be included in filenames using the string
17614 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
17616 Defaults to @samp{"/var/log/cups/error_log"}.
17619 @deftypevr {@code{files-configuration} parameter} string fatal-errors
17620 Specifies which errors are fatal, causing the scheduler to exit. The
17625 No errors are fatal.
17628 All of the errors below are fatal.
17631 Browsing initialization errors are fatal, for example failed connections
17632 to the DNS-SD daemon.
17635 Configuration file syntax errors are fatal.
17638 Listen or Port errors are fatal, except for IPv6 failures on the
17639 loopback or @code{any} addresses.
17642 Log file creation or write errors are fatal.
17645 Bad startup file permissions are fatal, for example shared TLS
17646 certificate and key files with world-read permissions.
17649 Defaults to @samp{"all -browse"}.
17652 @deftypevr {@code{files-configuration} parameter} boolean file-device?
17653 Specifies whether the file pseudo-device can be used for new printer
17654 queues. The URI @uref{file:///dev/null} is always allowed.
17656 Defaults to @samp{#f}.
17659 @deftypevr {@code{files-configuration} parameter} string group
17660 Specifies the group name or ID that will be used when executing external
17663 Defaults to @samp{"lp"}.
17666 @deftypevr {@code{files-configuration} parameter} string log-file-perm
17667 Specifies the permissions for all log files that the scheduler writes.
17669 Defaults to @samp{"0644"}.
17672 @deftypevr {@code{files-configuration} parameter} log-location page-log
17673 Defines the page log filename. Specifying a blank filename disables
17674 page log generation. The value @code{stderr} causes log entries to be
17675 sent to the standard error file when the scheduler is running in the
17676 foreground, or to the system log daemon when run in the background. The
17677 value @code{syslog} causes log entries to be sent to the system log
17678 daemon. The server name may be included in filenames using the string
17679 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
17681 Defaults to @samp{"/var/log/cups/page_log"}.
17684 @deftypevr {@code{files-configuration} parameter} string remote-root
17685 Specifies the username that is associated with unauthenticated accesses
17686 by clients claiming to be the root user. The default is @code{remroot}.
17688 Defaults to @samp{"remroot"}.
17691 @deftypevr {@code{files-configuration} parameter} file-name request-root
17692 Specifies the directory that contains print jobs and other HTTP request
17695 Defaults to @samp{"/var/spool/cups"}.
17698 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
17699 Specifies the level of security sandboxing that is applied to print
17700 filters, backends, and other child processes of the scheduler; either
17701 @code{relaxed} or @code{strict}. This directive is currently only
17702 used/supported on macOS.
17704 Defaults to @samp{strict}.
17707 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
17708 Specifies the location of TLS certificates and private keys. CUPS will
17709 look for public and private keys in this directory: @file{.crt} files
17710 for PEM-encoded certificates and corresponding @file{.key} files for
17711 PEM-encoded private keys.
17713 Defaults to @samp{"/etc/cups/ssl"}.
17716 @deftypevr {@code{files-configuration} parameter} file-name server-root
17717 Specifies the directory containing the server configuration files.
17719 Defaults to @samp{"/etc/cups"}.
17722 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
17723 Specifies whether the scheduler calls fsync(2) after writing
17724 configuration or state files.
17726 Defaults to @samp{#f}.
17729 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
17730 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
17733 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
17734 Specifies the directory where temporary files are stored.
17736 Defaults to @samp{"/var/spool/cups/tmp"}.
17739 @deftypevr {@code{files-configuration} parameter} string user
17740 Specifies the user name or ID that is used when running external
17743 Defaults to @samp{"lp"}.
17746 @deftypevr {@code{files-configuration} parameter} string set-env
17747 Set the specified environment variable to be passed to child processes.
17749 Defaults to @samp{"variable value"}.
17753 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
17754 Specifies the logging level for the AccessLog file. The @code{config}
17755 level logs when printers and classes are added, deleted, or modified and
17756 when configuration files are accessed or updated. The @code{actions}
17757 level logs when print jobs are submitted, held, released, modified, or
17758 canceled, and any of the conditions for @code{config}. The @code{all}
17759 level logs all requests.
17761 Defaults to @samp{actions}.
17764 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
17765 Specifies whether to purge job history data automatically when it is no
17766 longer required for quotas.
17768 Defaults to @samp{#f}.
17771 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
17772 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
17773 For example, @samp{"_cups" "_print"} will tell network clients that both
17774 CUPS sharing and IPP Everywhere are supported.
17776 Defaults to @samp{"_cups"}.
17779 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
17780 Specifies which protocols to use for local printer sharing.
17782 Defaults to @samp{dnssd}.
17785 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
17786 Specifies whether the CUPS web interface is advertised.
17788 Defaults to @samp{#f}.
17791 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
17792 Specifies whether shared printers are advertised.
17794 Defaults to @samp{#f}.
17797 @deftypevr {@code{cups-configuration} parameter} string classification
17798 Specifies the security classification of the server. Any valid banner
17799 name can be used, including @samp{"classified"}, @samp{"confidential"},
17800 @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
17801 banner can be omitted to disable secure printing functions.
17803 Defaults to @samp{""}.
17806 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
17807 Specifies whether users may override the classification (cover page) of
17808 individual print jobs using the @code{job-sheets} option.
17810 Defaults to @samp{#f}.
17813 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
17814 Specifies the default type of authentication to use.
17816 Defaults to @samp{Basic}.
17819 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
17820 Specifies whether encryption will be used for authenticated requests.
17822 Defaults to @samp{Required}.
17825 @deftypevr {@code{cups-configuration} parameter} string default-language
17826 Specifies the default language to use for text and web content.
17828 Defaults to @samp{"en"}.
17831 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
17832 Specifies the default paper size for new print queues. @samp{"Auto"}
17833 uses a locale-specific default, while @samp{"None"} specifies there is
17834 no default paper size. Specific size names are typically
17835 @samp{"Letter"} or @samp{"A4"}.
17837 Defaults to @samp{"Auto"}.
17840 @deftypevr {@code{cups-configuration} parameter} string default-policy
17841 Specifies the default access policy to use.
17843 Defaults to @samp{"default"}.
17846 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
17847 Specifies whether local printers are shared by default.
17849 Defaults to @samp{#t}.
17852 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
17853 Specifies the delay for updating of configuration and state files, in
17854 seconds. A value of 0 causes the update to happen as soon as possible,
17855 typically within a few milliseconds.
17857 Defaults to @samp{30}.
17860 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
17861 Specifies what to do when an error occurs. Possible values are
17862 @code{abort-job}, which will discard the failed print job;
17863 @code{retry-job}, which will retry the job at a later time;
17864 @code{retry-current-job}, which retries the failed job immediately; and
17865 @code{stop-printer}, which stops the printer.
17867 Defaults to @samp{stop-printer}.
17870 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
17871 Specifies the maximum cost of filters that are run concurrently, which
17872 can be used to minimize disk, memory, and CPU resource problems. A
17873 limit of 0 disables filter limiting. An average print to a
17874 non-PostScript printer needs a filter limit of about 200. A PostScript
17875 printer needs about half that (100). Setting the limit below these
17876 thresholds will effectively limit the scheduler to printing a single job
17879 Defaults to @samp{0}.
17882 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
17883 Specifies the scheduling priority of filters that are run to print a
17884 job. The nice value ranges from 0, the highest priority, to 19, the
17887 Defaults to @samp{0}.
17890 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
17891 Specifies whether to do reverse lookups on connecting clients. The
17892 @code{double} setting causes @code{cupsd} to verify that the hostname
17893 resolved from the address matches one of the addresses returned for that
17894 hostname. Double lookups also prevent clients with unregistered
17895 addresses from connecting to your server. Only set this option to
17896 @code{#t} or @code{double} if absolutely required.
17898 Defaults to @samp{#f}.
17901 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
17902 Specifies the number of seconds to wait before killing the filters and
17903 backend associated with a canceled or held job.
17905 Defaults to @samp{30}.
17908 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
17909 Specifies the interval between retries of jobs in seconds. This is
17910 typically used for fax queues but can also be used with normal print
17911 queues whose error policy is @code{retry-job} or
17912 @code{retry-current-job}.
17914 Defaults to @samp{30}.
17917 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
17918 Specifies the number of retries that are done for jobs. This is
17919 typically used for fax queues but can also be used with normal print
17920 queues whose error policy is @code{retry-job} or
17921 @code{retry-current-job}.
17923 Defaults to @samp{5}.
17926 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
17927 Specifies whether to support HTTP keep-alive connections.
17929 Defaults to @samp{#t}.
17932 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
17933 Specifies how long an idle client connection remains open, in seconds.
17935 Defaults to @samp{30}.
17938 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
17939 Specifies the maximum size of print files, IPP requests, and HTML form
17940 data. A limit of 0 disables the limit check.
17942 Defaults to @samp{0}.
17945 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
17946 Listens on the specified interfaces for connections. Valid values are
17947 of the form @var{address}:@var{port}, where @var{address} is either an
17948 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
17949 indicate all addresses. Values can also be file names of local UNIX
17950 domain sockets. The Listen directive is similar to the Port directive
17951 but allows you to restrict access to specific interfaces or networks.
17954 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
17955 Specifies the number of pending connections that will be allowed. This
17956 normally only affects very busy servers that have reached the MaxClients
17957 limit, but can also be triggered by large numbers of simultaneous
17958 connections. When the limit is reached, the operating system will
17959 refuse additional connections until the scheduler can accept the pending
17962 Defaults to @samp{128}.
17965 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
17966 Specifies a set of additional access controls.
17968 Available @code{location-access-controls} fields are:
17970 @deftypevr {@code{location-access-controls} parameter} file-name path
17971 Specifies the URI path to which the access control applies.
17974 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
17975 Access controls for all access to this path, in the same format as the
17976 @code{access-controls} of @code{operation-access-control}.
17978 Defaults to @samp{()}.
17981 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
17982 Access controls for method-specific access to this path.
17984 Defaults to @samp{()}.
17986 Available @code{method-access-controls} fields are:
17988 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
17989 If @code{#t}, apply access controls to all methods except the listed
17990 methods. Otherwise apply to only the listed methods.
17992 Defaults to @samp{#f}.
17995 @deftypevr {@code{method-access-controls} parameter} method-list methods
17996 Methods to which this access control applies.
17998 Defaults to @samp{()}.
18001 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
18002 Access control directives, as a list of strings. Each string should be
18003 one directive, such as @samp{"Order allow,deny"}.
18005 Defaults to @samp{()}.
18010 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
18011 Specifies the number of debugging messages that are retained for logging
18012 if an error occurs in a print job. Debug messages are logged regardless
18013 of the LogLevel setting.
18015 Defaults to @samp{100}.
18018 @deftypevr {@code{cups-configuration} parameter} log-level log-level
18019 Specifies the level of logging for the ErrorLog file. The value
18020 @code{none} stops all logging while @code{debug2} logs everything.
18022 Defaults to @samp{info}.
18025 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
18026 Specifies the format of the date and time in the log files. The value
18027 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
18029 Defaults to @samp{standard}.
18032 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
18033 Specifies the maximum number of simultaneous clients that are allowed by
18036 Defaults to @samp{100}.
18039 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
18040 Specifies the maximum number of simultaneous clients that are allowed
18041 from a single address.
18043 Defaults to @samp{100}.
18046 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
18047 Specifies the maximum number of copies that a user can print of each
18050 Defaults to @samp{9999}.
18053 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
18054 Specifies the maximum time a job may remain in the @code{indefinite}
18055 hold state before it is canceled. A value of 0 disables cancellation of
18058 Defaults to @samp{0}.
18061 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
18062 Specifies the maximum number of simultaneous jobs that are allowed. Set
18063 to 0 to allow an unlimited number of jobs.
18065 Defaults to @samp{500}.
18068 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
18069 Specifies the maximum number of simultaneous jobs that are allowed per
18070 printer. A value of 0 allows up to MaxJobs jobs per printer.
18072 Defaults to @samp{0}.
18075 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
18076 Specifies the maximum number of simultaneous jobs that are allowed per
18077 user. A value of 0 allows up to MaxJobs jobs per user.
18079 Defaults to @samp{0}.
18082 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
18083 Specifies the maximum time a job may take to print before it is
18084 canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
18086 Defaults to @samp{10800}.
18089 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
18090 Specifies the maximum size of the log files before they are rotated, in
18091 bytes. The value 0 disables log rotation.
18093 Defaults to @samp{1048576}.
18096 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
18097 Specifies the maximum amount of time to allow between files in a
18098 multiple file print job, in seconds.
18100 Defaults to @samp{300}.
18103 @deftypevr {@code{cups-configuration} parameter} string page-log-format
18104 Specifies the format of PageLog lines. Sequences beginning with percent
18105 (@samp{%}) characters are replaced with the corresponding information,
18106 while all other characters are copied literally. The following percent
18107 sequences are recognized:
18111 insert a single percent character
18114 insert the value of the specified IPP attribute
18117 insert the number of copies for the current page
18120 insert the current page number
18123 insert the current date and time in common log format
18129 insert the printer name
18132 insert the username
18135 A value of the empty string disables page logging. The string @code{%p
18136 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
18137 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
18140 Defaults to @samp{""}.
18143 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
18144 Passes the specified environment variable(s) to child processes; a list
18147 Defaults to @samp{()}.
18150 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
18151 Specifies named access control policies.
18153 Available @code{policy-configuration} fields are:
18155 @deftypevr {@code{policy-configuration} parameter} string name
18156 Name of the policy.
18159 @deftypevr {@code{policy-configuration} parameter} string job-private-access
18160 Specifies an access list for a job's private values. @code{@@ACL} maps
18161 to the printer's requesting-user-name-allowed or
18162 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
18163 owner. @code{@@SYSTEM} maps to the groups listed for the
18164 @code{system-group} field of the @code{files-config} configuration,
18165 which is reified into the @code{cups-files.conf(5)} file. Other
18166 possible elements of the access list include specific user names, and
18167 @code{@@@var{group}} to indicate members of a specific group. The
18168 access list may also be simply @code{all} or @code{default}.
18170 Defaults to @samp{"@@OWNER @@SYSTEM"}.
18173 @deftypevr {@code{policy-configuration} parameter} string job-private-values
18174 Specifies the list of job values to make private, or @code{all},
18175 @code{default}, or @code{none}.
18177 Defaults to @samp{"job-name job-originating-host-name
18178 job-originating-user-name phone"}.
18181 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
18182 Specifies an access list for a subscription's private values.
18183 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
18184 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
18185 owner. @code{@@SYSTEM} maps to the groups listed for the
18186 @code{system-group} field of the @code{files-config} configuration,
18187 which is reified into the @code{cups-files.conf(5)} file. Other
18188 possible elements of the access list include specific user names, and
18189 @code{@@@var{group}} to indicate members of a specific group. The
18190 access list may also be simply @code{all} or @code{default}.
18192 Defaults to @samp{"@@OWNER @@SYSTEM"}.
18195 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
18196 Specifies the list of job values to make private, or @code{all},
18197 @code{default}, or @code{none}.
18199 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
18200 notify-subscriber-user-name notify-user-data"}.
18203 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
18204 Access control by IPP operation.
18206 Defaults to @samp{()}.
18210 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
18211 Specifies whether job files (documents) are preserved after a job is
18212 printed. If a numeric value is specified, job files are preserved for
18213 the indicated number of seconds after printing. Otherwise a boolean
18214 value applies indefinitely.
18216 Defaults to @samp{86400}.
18219 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
18220 Specifies whether the job history is preserved after a job is printed.
18221 If a numeric value is specified, the job history is preserved for the
18222 indicated number of seconds after printing. If @code{#t}, the job
18223 history is preserved until the MaxJobs limit is reached.
18225 Defaults to @samp{#t}.
18228 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
18229 Specifies the amount of time to wait for job completion before
18230 restarting the scheduler.
18232 Defaults to @samp{30}.
18235 @deftypevr {@code{cups-configuration} parameter} string rip-cache
18236 Specifies the maximum amount of memory to use when converting documents
18237 into bitmaps for a printer.
18239 Defaults to @samp{"128m"}.
18242 @deftypevr {@code{cups-configuration} parameter} string server-admin
18243 Specifies the email address of the server administrator.
18245 Defaults to @samp{"root@@localhost.localdomain"}.
18248 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
18249 The ServerAlias directive is used for HTTP Host header validation when
18250 clients connect to the scheduler from external interfaces. Using the
18251 special name @code{*} can expose your system to known browser-based DNS
18252 rebinding attacks, even when accessing sites through a firewall. If the
18253 auto-discovery of alternate names does not work, we recommend listing
18254 each alternate name with a ServerAlias directive instead of using
18257 Defaults to @samp{*}.
18260 @deftypevr {@code{cups-configuration} parameter} string server-name
18261 Specifies the fully-qualified host name of the server.
18263 Defaults to @samp{"localhost"}.
18266 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
18267 Specifies what information is included in the Server header of HTTP
18268 responses. @code{None} disables the Server header. @code{ProductOnly}
18269 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
18270 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
18271 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
18272 the output of the @code{uname} command. @code{Full} reports @code{CUPS
18273 2.0.0 (@var{uname}) IPP/2.0}.
18275 Defaults to @samp{Minimal}.
18278 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
18279 Listens on the specified interfaces for encrypted connections. Valid
18280 values are of the form @var{address}:@var{port}, where @var{address} is
18281 either an IPv6 address enclosed in brackets, an IPv4 address, or
18282 @code{*} to indicate all addresses.
18284 Defaults to @samp{()}.
18287 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
18288 Sets encryption options. By default, CUPS only supports encryption
18289 using TLS v1.0 or higher using known secure cipher suites. Security is
18290 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
18291 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
18292 suites, which are required for some older clients. The @code{AllowSSL3} option
18293 enables SSL v3.0, which is required for some older clients that do not support
18294 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
18295 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
18296 protocol version to TLS v1.1.
18298 Defaults to @samp{()}.
18301 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
18302 Specifies whether the scheduler requires clients to strictly adhere to
18303 the IPP specifications.
18305 Defaults to @samp{#f}.
18308 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
18309 Specifies the HTTP request timeout, in seconds.
18311 Defaults to @samp{300}.
18315 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
18316 Specifies whether the web interface is enabled.
18318 Defaults to @samp{#f}.
18321 At this point you're probably thinking ``oh dear, Guix manual, I like
18322 you but you can stop already with the configuration options''. Indeed.
18323 However, one more point: it could be that you have an existing
18324 @code{cupsd.conf} that you want to use. In that case, you can pass an
18325 @code{opaque-cups-configuration} as the configuration of a
18326 @code{cups-service-type}.
18328 Available @code{opaque-cups-configuration} fields are:
18330 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
18334 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
18335 The contents of the @code{cupsd.conf}, as a string.
18338 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
18339 The contents of the @code{cups-files.conf} file, as a string.
18342 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
18343 strings of the same name, you could instantiate a CUPS service like
18347 (service cups-service-type
18348 (opaque-cups-configuration
18349 (cupsd.conf cupsd.conf)
18350 (cups-files.conf cups-files.conf)))
18354 @node Desktop Services
18355 @subsection Desktop Services
18357 The @code{(gnu services desktop)} module provides services that are
18358 usually useful in the context of a ``desktop'' setup---that is, on a
18359 machine running a graphical display server, possibly with graphical user
18360 interfaces, etc. It also defines services that provide specific desktop
18361 environments like GNOME, Xfce or MATE.
18363 To simplify things, the module defines a variable containing the set of
18364 services that users typically expect on a machine with a graphical
18365 environment and networking:
18367 @defvr {Scheme Variable} %desktop-services
18368 This is a list of services that builds upon @code{%base-services} and
18369 adds or adjusts services for a typical ``desktop'' setup.
18371 In particular, it adds a graphical login manager (@pxref{X Window,
18372 @code{gdm-service-type}}), screen lockers, a network management tool
18373 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
18374 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
18375 energy and color management services, the @code{elogind} login and seat
18376 manager, the Polkit privilege service, the GeoClue location service, the
18377 AccountsService daemon that allows authorized users change system passwords,
18378 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
18379 name service switch service configured to be able to use @code{nss-mdns}
18380 (@pxref{Name Service Switch, mDNS}).
18383 The @code{%desktop-services} variable can be used as the @code{services}
18384 field of an @code{operating-system} declaration (@pxref{operating-system
18385 Reference, @code{services}}).
18387 Additionally, the @code{gnome-desktop-service-type},
18388 @code{xfce-desktop-service}, @code{mate-desktop-service-type},
18389 @code{lxqt-desktop-service-type} and @code{enlightenment-desktop-service-type}
18390 procedures can add GNOME, Xfce, MATE and/or Enlightenment to a system. To
18391 ``add GNOME'' means that system-level services like the backlight adjustment
18392 helpers and the power management utilities are added to the system, extending
18393 @code{polkit} and @code{dbus} appropriately, allowing GNOME to operate with
18394 elevated privileges on a limited number of special-purpose system interfaces.
18395 Additionally, adding a service made by @code{gnome-desktop-service-type} adds
18396 the GNOME metapackage to the system profile. Likewise, adding the Xfce
18397 service not only adds the @code{xfce} metapackage to the system profile, but
18398 it also gives the Thunar file manager the ability to open a ``root-mode'' file
18399 management window, if the user authenticates using the administrator's
18400 password via the standard polkit graphical interface. To ``add MATE'' means
18401 that @code{polkit} and @code{dbus} are extended appropriately, allowing MATE
18402 to operate with elevated privileges on a limited number of special-purpose
18403 system interfaces. Additionally, adding a service of type
18404 @code{mate-desktop-service-type} adds the MATE metapackage to the system
18405 profile. ``Adding Enlightenment'' means that @code{dbus} is extended
18406 appropriately, and several of Enlightenment's binaries are set as setuid,
18407 allowing Enlightenment's screen locker and other functionality to work as
18410 The desktop environments in Guix use the Xorg display server by
18411 default. If you'd like to use the newer display server protocol
18412 called Wayland, you need to use the @code{sddm-service} instead of
18413 GDM as the graphical login manager. You should then
18414 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
18415 also try starting GNOME on Wayland manually from a TTY with the
18416 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
18417 gnome-session``. Currently only GNOME has support for Wayland.
18419 @defvr {Scheme Variable} gnome-desktop-service-type
18420 This is the type of the service that adds the @uref{https://www.gnome.org,
18421 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
18422 object (see below).
18424 This service adds the @code{gnome} package to the system profile, and extends
18425 polkit with the actions from @code{gnome-settings-daemon}.
18428 @deftp {Data Type} gnome-desktop-configuration
18429 Configuration record for the GNOME desktop environment.
18432 @item @code{gnome} (default: @code{gnome})
18433 The GNOME package to use.
18437 @defvr {Scheme Variable} xfce-desktop-service-type
18438 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
18439 desktop environment. Its value is an @code{xfce-desktop-configuration} object
18442 This service adds the @code{xfce} package to the system profile, and
18443 extends polkit with the ability for @code{thunar} to manipulate the file
18444 system as root from within a user session, after the user has authenticated
18445 with the administrator's password.
18448 @deftp {Data Type} xfce-desktop-configuration
18449 Configuration record for the Xfce desktop environment.
18452 @item @code{xfce} (default: @code{xfce})
18453 The Xfce package to use.
18457 @deffn {Scheme Variable} mate-desktop-service-type
18458 This is the type of the service that runs the @uref{https://mate-desktop.org/,
18459 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
18460 object (see below).
18462 This service adds the @code{mate} package to the system
18463 profile, and extends polkit with the actions from
18464 @code{mate-settings-daemon}.
18467 @deftp {Data Type} mate-desktop-configuration
18468 Configuration record for the MATE desktop environment.
18471 @item @code{mate} (default: @code{mate})
18472 The MATE package to use.
18476 @deffn {Scheme Variable} lxqt-desktop-service-type
18477 This is the type of the service that runs the @uref{https://lxqt.github.io,
18478 LXQt desktop environment}. Its value is a @code{lxqt-desktop-configuration}
18479 object (see below).
18481 This service adds the @code{lxqt} package to the system
18485 @deftp {Data Type} lxqt-desktop-configuration
18486 Configuration record for the LXQt desktop environment.
18489 @item @code{lxqt} (default: @code{lxqt})
18490 The LXQT package to use.
18494 @deffn {Scheme Variable} enlightenment-desktop-service-type
18495 Return a service that adds the @code{enlightenment} package to the system
18496 profile, and extends dbus with actions from @code{efl}.
18499 @deftp {Data Type} enlightenment-desktop-service-configuration
18501 @item @code{enlightenment} (default: @code{enlightenment})
18502 The enlightenment package to use.
18506 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
18507 the default @code{%desktop-services} variable doesn't include any of
18508 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
18509 @code{%desktop-services} in the @code{services} field of your
18510 @code{operating-system}:
18513 (use-modules (gnu))
18514 (use-service-modules desktop)
18517 ;; cons* adds items to the list given as its last argument.
18518 (services (cons* (service gnome-desktop-service-type)
18519 (service xfce-desktop-service)
18520 %desktop-services))
18524 These desktop environments will then be available as options in the
18525 graphical login window.
18527 The actual service definitions included in @code{%desktop-services} and
18528 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
18529 are described below.
18531 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
18532 Return a service that runs the ``system bus'', using @var{dbus}, with
18533 support for @var{services}.
18535 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
18536 facility. Its system bus is used to allow system services to communicate
18537 and to be notified of system-wide events.
18539 @var{services} must be a list of packages that provide an
18540 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
18541 and policy files. For example, to allow avahi-daemon to use the system bus,
18542 @var{services} must be equal to @code{(list avahi)}.
18545 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
18546 Return a service that runs the @code{elogind} login and
18547 seat management daemon. @uref{https://github.com/elogind/elogind,
18548 Elogind} exposes a D-Bus interface that can be used to know which users
18549 are logged in, know what kind of sessions they have open, suspend the
18550 system, inhibit system suspend, reboot the system, and other tasks.
18552 Elogind handles most system-level power events for a computer, for
18553 example suspending the system when a lid is closed, or shutting it down
18554 when the power button is pressed.
18556 The @var{config} keyword argument specifies the configuration for
18557 elogind, and should be the result of an @code{(elogind-configuration
18558 (@var{parameter} @var{value})...)} invocation. Available parameters and
18559 their default values are:
18562 @item kill-user-processes?
18564 @item kill-only-users
18566 @item kill-exclude-users
18568 @item inhibit-delay-max-seconds
18570 @item handle-power-key
18572 @item handle-suspend-key
18574 @item handle-hibernate-key
18576 @item handle-lid-switch
18578 @item handle-lid-switch-docked
18580 @item handle-lid-switch-external-power
18582 @item power-key-ignore-inhibited?
18584 @item suspend-key-ignore-inhibited?
18586 @item hibernate-key-ignore-inhibited?
18588 @item lid-switch-ignore-inhibited?
18590 @item holdoff-timeout-seconds
18594 @item idle-action-seconds
18596 @item runtime-directory-size-percent
18598 @item runtime-directory-size
18602 @item suspend-state
18603 @code{("mem" "standby" "freeze")}
18606 @item hibernate-state
18608 @item hibernate-mode
18609 @code{("platform" "shutdown")}
18610 @item hybrid-sleep-state
18612 @item hybrid-sleep-mode
18613 @code{("suspend" "platform" "shutdown")}
18617 @deffn {Scheme Procedure} accountsservice-service @
18618 [#:accountsservice @var{accountsservice}]
18619 Return a service that runs AccountsService, a system service that can
18620 list available accounts, change their passwords, and so on.
18621 AccountsService integrates with PolicyKit to enable unprivileged users
18622 to acquire the capability to modify their system configuration.
18623 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
18624 accountsservice web site} for more information.
18626 The @var{accountsservice} keyword argument is the @code{accountsservice}
18627 package to expose as a service.
18630 @deffn {Scheme Procedure} polkit-service @
18631 [#:polkit @var{polkit}]
18632 Return a service that runs the
18633 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
18634 management service}, which allows system administrators to grant access to
18635 privileged operations in a structured way. By querying the Polkit service, a
18636 privileged system component can know when it should grant additional
18637 capabilities to ordinary users. For example, an ordinary user can be granted
18638 the capability to suspend the system if the user is logged in locally.
18641 @defvr {Scheme Variable} polkit-wheel-service
18642 Service that adds the @code{wheel} group as admins to the Polkit
18643 service. This makes it so that users in the @code{wheel} group are queried
18644 for their own passwords when performing administrative actions instead of
18645 @code{root}'s, similar to the behaviour used by @code{sudo}.
18648 @defvr {Scheme Variable} upower-service-type
18649 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
18650 system-wide monitor for power consumption and battery levels, with the given
18651 configuration settings.
18653 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
18654 notably used by GNOME.
18657 @deftp {Data Type} upower-configuration
18658 Data type representation the configuration for UPower.
18662 @item @code{upower} (default: @var{upower})
18663 Package to use for @code{upower}.
18665 @item @code{watts-up-pro?} (default: @code{#f})
18666 Enable the Watts Up Pro device.
18668 @item @code{poll-batteries?} (default: @code{#t})
18669 Enable polling the kernel for battery level changes.
18671 @item @code{ignore-lid?} (default: @code{#f})
18672 Ignore the lid state, this can be useful if it's incorrect on a device.
18674 @item @code{use-percentage-for-policy?} (default: @code{#f})
18675 Whether battery percentage based policy should be used. The default is to use
18676 the time left, change to @code{#t} to use the percentage.
18678 @item @code{percentage-low} (default: @code{10})
18679 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
18680 at which the battery is considered low.
18682 @item @code{percentage-critical} (default: @code{3})
18683 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
18684 at which the battery is considered critical.
18686 @item @code{percentage-action} (default: @code{2})
18687 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
18688 at which action will be taken.
18690 @item @code{time-low} (default: @code{1200})
18691 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
18692 seconds at which the battery is considered low.
18694 @item @code{time-critical} (default: @code{300})
18695 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
18696 seconds at which the battery is considered critical.
18698 @item @code{time-action} (default: @code{120})
18699 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
18700 seconds at which action will be taken.
18702 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
18703 The action taken when @code{percentage-action} or @code{time-action} is
18704 reached (depending on the configuration of @code{use-percentage-for-policy?}).
18706 Possible values are:
18716 @code{'hybrid-sleep}.
18722 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
18723 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
18724 UDisks}, a @dfn{disk management} daemon that provides user interfaces
18725 with notifications and ways to mount/unmount disks. Programs that talk
18726 to UDisks include the @command{udisksctl} command, part of UDisks, and
18727 GNOME Disks. Note that Udisks relies on the @command{mount} command, so
18728 it will only be able to use the file-system utilities installed in the
18729 system profile. For example if you want to be able to mount NTFS
18730 file-systems in read and write fashion, you'll need to have
18731 @code{ntfs-3g} installed system-wide.
18734 @deffn {Scheme Variable} colord-service-type
18735 This is the type of the service that runs @command{colord}, a system
18736 service with a D-Bus
18737 interface to manage the color profiles of input and output devices such as
18738 screens and scanners. It is notably used by the GNOME Color Manager graphical
18739 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
18740 site} for more information.
18743 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
18744 Return a configuration allowing an application to access GeoClue
18745 location data. @var{name} is the Desktop ID of the application, without
18746 the @code{.desktop} part. If @var{allowed?} is true, the application
18747 will have access to location information by default. The boolean
18748 @var{system?} value indicates whether an application is a system component
18749 or not. Finally @var{users} is a list of UIDs of all users for which
18750 this application is allowed location info access. An empty users list
18751 means that all users are allowed.
18754 @cindex scanner access
18755 @deffn {Scheme Procedure} sane-service-type
18756 This service provides access to scanners @i{via}
18757 @uref{http://www.sane-project.org, SANE} by installing the necessary udev
18761 @defvr {Scheme Variable} %standard-geoclue-applications
18762 The standard list of well-known GeoClue application configurations,
18763 granting authority to the GNOME date-and-time utility to ask for the
18764 current location in order to set the time zone, and allowing the
18765 IceCat and Epiphany web browsers to request location information.
18766 IceCat and Epiphany both query the user before allowing a web page to
18767 know the user's location.
18770 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
18771 [#:whitelist '()] @
18772 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
18773 [#:submit-data? #f]
18774 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
18775 [#:submission-nick "geoclue"] @
18776 [#:applications %standard-geoclue-applications]
18777 Return a service that runs the GeoClue location service. This service
18778 provides a D-Bus interface to allow applications to request access to a
18779 user's physical location, and optionally to add information to online
18780 location databases. See
18781 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
18782 web site} for more information.
18785 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
18786 [@w{#:auto-enable? #f}]
18787 Return a service that runs the @command{bluetoothd} daemon, which
18788 manages all the Bluetooth devices and provides a number of D-Bus
18789 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
18790 powered automatically at boot, which can be useful when using a
18791 bluetooth keyboard or mouse.
18793 Users need to be in the @code{lp} group to access the D-Bus service.
18796 @defvr {Scheme Variable} gnome-keyring-service-type
18797 This is the type of the service that adds the
18798 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
18799 value is a @code{gnome-keyring-configuration} object (see below).
18801 This service adds the @code{gnome-keyring} package to the system profile
18802 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
18803 a user's login keyring when they log in or setting its password with passwd.
18806 @deftp {Data Type} gnome-keyring-configuration
18807 Configuration record for the GNOME Keyring service.
18810 @item @code{keyring} (default: @code{gnome-keyring})
18811 The GNOME keyring package to use.
18813 @item @code{pam-services}
18814 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
18815 services to extend, where @var{service} is the name of an existing
18816 service to extend and @var{kind} is one of @code{login} or
18819 If @code{login} is given, it adds an optional
18820 @code{pam_gnome_keyring.so} to the auth block without arguments and to
18821 the session block with @code{auto_start}. If @code{passwd} is given, it
18822 adds an optional @code{pam_gnome_keyring.so} to the password block
18825 By default, this field contains ``gdm-password'' with the value @code{login}
18826 and ``passwd'' is with the value @code{passwd}.
18831 @node Sound Services
18832 @subsection Sound Services
18834 @cindex sound support
18836 @cindex PulseAudio, sound support
18838 The @code{(gnu services sound)} module provides a service to configure the
18839 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
18840 preferred ALSA output driver.
18842 @deffn {Scheme Variable} alsa-service-type
18843 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
18844 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
18845 configuration file. The value for this type is a @command{alsa-configuration}
18846 record as in this example:
18849 (service alsa-service-type)
18852 See below for details about @code{alsa-configuration}.
18855 @deftp {Data Type} alsa-configuration
18856 Data type representing the configuration for @code{alsa-service}.
18859 @item @code{alsa-plugins} (default: @var{alsa-plugins})
18860 @code{alsa-plugins} package to use.
18862 @item @code{pulseaudio?} (default: @var{#t})
18863 Whether ALSA applications should transparently be made to use the
18864 @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
18866 Using PulseAudio allows you to run several sound-producing applications
18867 at the same time and to individual control them @i{via}
18868 @command{pavucontrol}, among other things.
18870 @item @code{extra-options} (default: @var{""})
18871 String to append to the @file{/etc/asound.conf} file.
18876 Individual users who want to override the system configuration of ALSA can do
18877 it with the @file{~/.asoundrc} file:
18880 # In guix, we have to specify the absolute path for plugins.
18882 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
18885 # Routing ALSA to jack:
18886 # <http://jackaudio.org/faq/routing_alsa.html>.
18890 0 system:playback_1
18891 1 system:playback_2
18908 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
18911 @deffn {Scheme Variable} pulseaudio-service-type
18912 This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
18913 sound server. It exists to allow system overrides of the default settings
18914 via @code{pulseaudio-configuration}, see below.
18917 This service overrides per-user configuration files. If you want
18918 PulseAudio to honor configuration files in @file{~/.config/pulse} you
18919 have to unset the environment variables @env{PULSE_CONFIG} and
18920 @env{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
18924 This service on its own does not ensure, that the @code{pulseaudio} package
18925 exists on your machine. It merely adds configuration files for it, as
18926 detailed below. In the (admittedly unlikely) case, that you find yourself
18927 without a @code{pulseaudio} package, consider enabling it through the
18928 @code{alsa-service-type} above.
18932 @deftp {Data Type} pulseaudio-configuration
18933 Data type representing the configuration for @code{pulseaudio-service}.
18936 @item @code{client-conf} (default: @code{'()})
18937 List of settings to set in @file{client.conf}.
18938 Accepts a list of strings or a symbol-value pairs. A string will be
18939 inserted as-is with a newline added. A pair will be formatted as
18940 ``key = value'', again with a newline added.
18942 @item @code{daemon-conf} (default: @code{'((flat-volumes . no))})
18943 List of settings to set in @file{daemon.conf}, formatted just like
18946 @item @code{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
18947 Script file to use as @file{default.pa}.
18949 @item @code{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
18950 Script file to use as @file{system.pa}.
18954 @deffn {Scheme Variable} ladspa-service-type
18955 This service sets the @var{LADSPA_PATH} variable, so that programs, which
18956 respect it, e.g. PulseAudio, can load LADSPA plugins.
18958 The following example will setup the service to enable modules from the
18959 @code{swh-plugins} package:
18962 (service ladspa-service-type
18963 (ladspa-configuration (plugins (list swh-plugins))))
18966 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
18971 @node Database Services
18972 @subsection Database Services
18976 The @code{(gnu services databases)} module provides the following services.
18978 @subsubheading PostgreSQL
18980 The following example describes a PostgreSQL service with the default
18984 (service postgresql-service-type
18985 (postgresql-configuration
18986 (postgresql postgresql-10)))
18989 If the services fails to start, it may be due to an incompatible
18990 cluster already present in @var{data-directory}. Adjust it (or, if you
18991 don't need the cluster anymore, delete @var{data-directory}), then
18992 restart the service.
18994 Peer authentication is used by default and the @code{postgres} user
18995 account has no shell, which prevents the direct execution of @code{psql}
18996 commands as this user. To use @code{psql}, you can temporarily log in
18997 as @code{postgres} using a shell, create a PostgreSQL superuser with the
18998 same name as one of the system users and then create the associated
19002 sudo -u postgres -s /bin/sh
19003 createuser --interactive
19004 createdb $MY_USER_LOGIN # Replace appropriately.
19007 @deftp {Data Type} postgresql-configuration
19008 Data type representing the configuration for the
19009 @code{postgresql-service-type}.
19012 @item @code{postgresql}
19013 PostgreSQL package to use for the service.
19015 @item @code{port} (default: @code{5432})
19016 Port on which PostgreSQL should listen.
19018 @item @code{locale} (default: @code{"en_US.utf8"})
19019 Locale to use as the default when creating the database cluster.
19021 @item @code{config-file} (default: @code{(postgresql-config-file)})
19022 The configuration file to use when running PostgreSQL. The default
19023 behaviour uses the postgresql-config-file record with the default values
19026 @item @code{data-directory} (default: @code{"/var/lib/postgresql/data"})
19027 Directory in which to store the data.
19029 @item @code{extension-packages} (default: @code{'()})
19030 @cindex postgresql extension-packages
19031 Additional extensions are loaded from packages listed in
19032 @var{extension-packages}. Extensions are available at runtime. For instance,
19033 to create a geographic database using the @code{postgis} extension, a user can
19034 configure the postgresql-service as in this example:
19038 (use-package-modules databases geo)
19042 ;; postgresql is required to run `psql' but postgis is not required for
19043 ;; proper operation.
19044 (packages (cons* postgresql %base-packages))
19047 (service postgresql-service-type
19048 (postgresql-configuration
19049 (postgresql postgresql-10)
19050 (extension-packages (list postgis))))
19054 Then the extension becomes visible and you can initialise an empty geographic
19055 database in this way:
19059 > create database postgistest;
19060 > \connect postgistest;
19061 > create extension postgis;
19062 > create extension postgis_topology;
19065 There is no need to add this field for contrib extensions such as hstore or
19066 dblink as they are already loadable by postgresql. This field is only
19067 required to add extensions provided by other packages.
19072 @deftp {Data Type} postgresql-config-file
19073 Data type representing the PostgreSQL configuration file. As shown in
19074 the following example, this can be used to customize the configuration
19075 of PostgreSQL. Note that you can use any G-expression or filename in
19076 place of this record, if you already have a configuration file you'd
19077 like to use for example.
19080 (service postgresql-service-type
19081 (postgresql-configuration
19083 (postgresql-config-file
19084 (log-destination "stderr")
19086 (plain-file "pg_hba.conf"
19088 local all all trust
19089 host all all 127.0.0.1/32 md5
19090 host all all ::1/128 md5"))
19092 '(("session_preload_libraries" "'auto_explain'")
19093 ("random_page_cost" "2")
19094 ("auto_explain.log_min_duration" "'100ms'")
19095 ("work_mem" "'500MB'")
19096 ("logging_collector" "on")
19097 ("log_directory" "'/var/log/postgresql'")))))))
19101 @item @code{log-destination} (default: @code{"syslog"})
19102 The logging method to use for PostgreSQL. Multiple values are accepted,
19103 separated by commas.
19105 @item @code{hba-file} (default: @code{%default-postgres-hba})
19106 Filename or G-expression for the host-based authentication
19109 @item @code{ident-file} (default: @code{%default-postgres-ident})
19110 Filename or G-expression for the user name mapping configuration.
19112 @item @code{extra-config} (default: @code{'()})
19113 List of additional keys and values to include in the PostgreSQL config
19114 file. Each entry in the list should be a list where the first element
19115 is the key, and the remaining elements are the values.
19120 @subsubheading MariaDB/MySQL
19122 @defvr {Scheme Variable} mysql-service-type
19123 This is the service type for a MySQL or MariaDB database server. Its value
19124 is a @code{mysql-configuration} object that specifies which package to use,
19125 as well as various settings for the @command{mysqld} daemon.
19128 @deftp {Data Type} mysql-configuration
19129 Data type representing the configuration of @var{mysql-service-type}.
19132 @item @code{mysql} (default: @var{mariadb})
19133 Package object of the MySQL database server, can be either @var{mariadb}
19136 For MySQL, a temporary root password will be displayed at activation time.
19137 For MariaDB, the root password is empty.
19139 @item @code{bind-address} (default: @code{"127.0.0.1"})
19140 The IP on which to listen for network connections. Use @code{"0.0.0.0"}
19141 to bind to all available network interfaces.
19143 @item @code{port} (default: @code{3306})
19144 TCP port on which the database server listens for incoming connections.
19146 @item @code{socket} (default: @code{"/run/mysqld/mysqld.sock"})
19147 Socket file to use for local (non-network) connections.
19149 @item @code{extra-content} (default: @code{""})
19150 Additional settings for the @file{my.cnf} configuration file.
19152 @item @code{auto-upgrade?} (default: @code{#t})
19153 Whether to automatically run @command{mysql_upgrade} after starting the
19154 service. This is necessary to upgrade the @dfn{system schema} after
19155 ``major'' updates (such as switching from MariaDB 10.4 to 10.5), but can
19156 be disabled if you would rather do that manually.
19161 @subsubheading Memcached
19163 @defvr {Scheme Variable} memcached-service-type
19164 This is the service type for the @uref{https://memcached.org/,
19165 Memcached} service, which provides a distributed in memory cache. The
19166 value for the service type is a @code{memcached-configuration} object.
19170 (service memcached-service-type)
19173 @deftp {Data Type} memcached-configuration
19174 Data type representing the configuration of memcached.
19177 @item @code{memcached} (default: @code{memcached})
19178 The Memcached package to use.
19180 @item @code{interfaces} (default: @code{'("0.0.0.0")})
19181 Network interfaces on which to listen.
19183 @item @code{tcp-port} (default: @code{11211})
19184 Port on which to accept connections.
19186 @item @code{udp-port} (default: @code{11211})
19187 Port on which to accept UDP connections on, a value of 0 will disable
19188 listening on a UDP socket.
19190 @item @code{additional-options} (default: @code{'()})
19191 Additional command line options to pass to @code{memcached}.
19195 @subsubheading MongoDB
19197 @defvr {Scheme Variable} mongodb-service-type
19198 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
19199 The value for the service type is a @code{mongodb-configuration} object.
19203 (service mongodb-service-type)
19206 @deftp {Data Type} mongodb-configuration
19207 Data type representing the configuration of mongodb.
19210 @item @code{mongodb} (default: @code{mongodb})
19211 The MongoDB package to use.
19213 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
19214 The configuration file for MongoDB.
19216 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
19217 This value is used to create the directory, so that it exists and is
19218 owned by the mongodb user. It should match the data-directory which
19219 MongoDB is configured to use through the configuration file.
19223 @subsubheading Redis
19225 @defvr {Scheme Variable} redis-service-type
19226 This is the service type for the @uref{https://redis.io/, Redis}
19227 key/value store, whose value is a @code{redis-configuration} object.
19230 @deftp {Data Type} redis-configuration
19231 Data type representing the configuration of redis.
19234 @item @code{redis} (default: @code{redis})
19235 The Redis package to use.
19237 @item @code{bind} (default: @code{"127.0.0.1"})
19238 Network interface on which to listen.
19240 @item @code{port} (default: @code{6379})
19241 Port on which to accept connections on, a value of 0 will disable
19242 listening on a TCP socket.
19244 @item @code{working-directory} (default: @code{"/var/lib/redis"})
19245 Directory in which to store the database and related files.
19249 @node Mail Services
19250 @subsection Mail Services
19254 The @code{(gnu services mail)} module provides Guix service definitions
19255 for email services: IMAP, POP3, and LMTP servers, as well as mail
19256 transport agents (MTAs). Lots of acronyms! These services are detailed
19257 in the subsections below.
19259 @subsubheading Dovecot Service
19261 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
19262 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
19265 By default, Dovecot does not need much configuration; the default
19266 configuration object created by @code{(dovecot-configuration)} will
19267 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
19268 certificate will be generated for TLS-protected connections, though
19269 Dovecot will also listen on cleartext ports by default. There are a
19270 number of options, though, which mail administrators might need to change,
19271 and as is the case with other services, Guix allows the system
19272 administrator to specify these parameters via a uniform Scheme interface.
19274 For example, to specify that mail is located at @code{maildir~/.mail},
19275 one would instantiate the Dovecot service like this:
19278 (dovecot-service #:config
19279 (dovecot-configuration
19280 (mail-location "maildir:~/.mail")))
19283 The available configuration parameters follow. Each parameter
19284 definition is preceded by its type; for example, @samp{string-list foo}
19285 indicates that the @code{foo} parameter should be specified as a list of
19286 strings. There is also a way to specify the configuration as a string,
19287 if you have an old @code{dovecot.conf} file that you want to port over
19288 from some other system; see the end for more details.
19290 @c The following documentation was initially generated by
19291 @c (generate-documentation) in (gnu services mail). Manually maintained
19292 @c documentation is better, so we shouldn't hesitate to edit below as
19293 @c needed. However if the change you want to make to this documentation
19294 @c can be done in an automated way, it's probably easier to change
19295 @c (generate-documentation) than to make it below and have to deal with
19296 @c the churn as dovecot updates.
19298 Available @code{dovecot-configuration} fields are:
19300 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
19301 The dovecot package.
19304 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
19305 A list of IPs or hosts where to listen for connections. @samp{*}
19306 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
19307 interfaces. If you want to specify non-default ports or anything more
19308 complex, customize the address and port fields of the
19309 @samp{inet-listener} of the specific services you are interested in.
19312 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
19313 List of protocols we want to serve. Available protocols include
19314 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
19316 Available @code{protocol-configuration} fields are:
19318 @deftypevr {@code{protocol-configuration} parameter} string name
19319 The name of the protocol.
19322 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
19323 UNIX socket path to the master authentication server to find users.
19324 This is used by imap (for shared users) and lda.
19325 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
19328 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
19329 Space separated list of plugins to load.
19332 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
19333 Maximum number of IMAP connections allowed for a user from each IP
19334 address. NOTE: The username is compared case-sensitively.
19335 Defaults to @samp{10}.
19340 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
19341 List of services to enable. Available services include @samp{imap},
19342 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
19345 Available @code{service-configuration} fields are:
19347 @deftypevr {@code{service-configuration} parameter} string kind
19348 The service kind. Valid values include @code{director},
19349 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
19350 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
19351 @code{tcpwrap}, @code{quota-warning}, or anything else.
19354 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
19355 Listeners for the service. A listener is either a
19356 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
19357 an @code{inet-listener-configuration}.
19358 Defaults to @samp{()}.
19360 Available @code{unix-listener-configuration} fields are:
19362 @deftypevr {@code{unix-listener-configuration} parameter} string path
19363 Path to the file, relative to @code{base-dir} field. This is also used as
19367 @deftypevr {@code{unix-listener-configuration} parameter} string mode
19368 The access mode for the socket.
19369 Defaults to @samp{"0600"}.
19372 @deftypevr {@code{unix-listener-configuration} parameter} string user
19373 The user to own the socket.
19374 Defaults to @samp{""}.
19377 @deftypevr {@code{unix-listener-configuration} parameter} string group
19378 The group to own the socket.
19379 Defaults to @samp{""}.
19383 Available @code{fifo-listener-configuration} fields are:
19385 @deftypevr {@code{fifo-listener-configuration} parameter} string path
19386 Path to the file, relative to @code{base-dir} field. This is also used as
19390 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
19391 The access mode for the socket.
19392 Defaults to @samp{"0600"}.
19395 @deftypevr {@code{fifo-listener-configuration} parameter} string user
19396 The user to own the socket.
19397 Defaults to @samp{""}.
19400 @deftypevr {@code{fifo-listener-configuration} parameter} string group
19401 The group to own the socket.
19402 Defaults to @samp{""}.
19406 Available @code{inet-listener-configuration} fields are:
19408 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
19409 The protocol to listen for.
19412 @deftypevr {@code{inet-listener-configuration} parameter} string address
19413 The address on which to listen, or empty for all addresses.
19414 Defaults to @samp{""}.
19417 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
19418 The port on which to listen.
19421 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
19422 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
19424 Defaults to @samp{#t}.
19429 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
19430 Maximum number of simultaneous client connections per process. Once
19431 this number of connections is received, the next incoming connection
19432 will prompt Dovecot to spawn another process. If set to 0,
19433 @code{default-client-limit} is used instead.
19435 Defaults to @samp{0}.
19439 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
19440 Number of connections to handle before starting a new process.
19441 Typically the only useful values are 0 (unlimited) or 1. 1 is more
19442 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
19443 Defaults to @samp{1}.
19447 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
19448 Maximum number of processes that can exist for this service. If set to
19449 0, @code{default-process-limit} is used instead.
19451 Defaults to @samp{0}.
19455 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
19456 Number of processes to always keep waiting for more connections.
19457 Defaults to @samp{0}.
19460 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
19461 If you set @samp{service-count 0}, you probably need to grow
19463 Defaults to @samp{256000000}.
19468 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
19469 Dict configuration, as created by the @code{dict-configuration}
19472 Available @code{dict-configuration} fields are:
19474 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
19475 A list of key-value pairs that this dict should hold.
19476 Defaults to @samp{()}.
19481 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
19482 A list of passdb configurations, each one created by the
19483 @code{passdb-configuration} constructor.
19485 Available @code{passdb-configuration} fields are:
19487 @deftypevr {@code{passdb-configuration} parameter} string driver
19488 The driver that the passdb should use. Valid values include
19489 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
19491 Defaults to @samp{"pam"}.
19494 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
19495 Space separated list of arguments to the passdb driver.
19496 Defaults to @samp{""}.
19501 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
19502 List of userdb configurations, each one created by the
19503 @code{userdb-configuration} constructor.
19505 Available @code{userdb-configuration} fields are:
19507 @deftypevr {@code{userdb-configuration} parameter} string driver
19508 The driver that the userdb should use. Valid values include
19509 @samp{passwd} and @samp{static}.
19510 Defaults to @samp{"passwd"}.
19513 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
19514 Space separated list of arguments to the userdb driver.
19515 Defaults to @samp{""}.
19518 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
19519 Override fields from passwd.
19520 Defaults to @samp{()}.
19525 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
19526 Plug-in configuration, created by the @code{plugin-configuration}
19530 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
19531 List of namespaces. Each item in the list is created by the
19532 @code{namespace-configuration} constructor.
19534 Available @code{namespace-configuration} fields are:
19536 @deftypevr {@code{namespace-configuration} parameter} string name
19537 Name for this namespace.
19540 @deftypevr {@code{namespace-configuration} parameter} string type
19541 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
19542 Defaults to @samp{"private"}.
19545 @deftypevr {@code{namespace-configuration} parameter} string separator
19546 Hierarchy separator to use. You should use the same separator for
19547 all namespaces or some clients get confused. @samp{/} is usually a good
19548 one. The default however depends on the underlying mail storage
19550 Defaults to @samp{""}.
19553 @deftypevr {@code{namespace-configuration} parameter} string prefix
19554 Prefix required to access this namespace. This needs to be
19555 different for all namespaces. For example @samp{Public/}.
19556 Defaults to @samp{""}.
19559 @deftypevr {@code{namespace-configuration} parameter} string location
19560 Physical location of the mailbox. This is in the same format as
19561 mail_location, which is also the default for it.
19562 Defaults to @samp{""}.
19565 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
19566 There can be only one INBOX, and this setting defines which
19568 Defaults to @samp{#f}.
19571 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
19572 If namespace is hidden, it's not advertised to clients via NAMESPACE
19573 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
19574 useful when converting from another server with different namespaces
19575 which you want to deprecate but still keep working. For example you can
19576 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
19578 Defaults to @samp{#f}.
19581 @deftypevr {@code{namespace-configuration} parameter} boolean list?
19582 Show the mailboxes under this namespace with the LIST command. This
19583 makes the namespace visible for clients that do not support the NAMESPACE
19584 extension. The special @code{children} value lists child mailboxes, but
19585 hides the namespace prefix.
19586 Defaults to @samp{#t}.
19589 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
19590 Namespace handles its own subscriptions. If set to @code{#f}, the
19591 parent namespace handles them. The empty prefix should always have this
19593 Defaults to @samp{#t}.
19596 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
19597 List of predefined mailboxes in this namespace.
19598 Defaults to @samp{()}.
19600 Available @code{mailbox-configuration} fields are:
19602 @deftypevr {@code{mailbox-configuration} parameter} string name
19603 Name for this mailbox.
19606 @deftypevr {@code{mailbox-configuration} parameter} string auto
19607 @samp{create} will automatically create this mailbox.
19608 @samp{subscribe} will both create and subscribe to the mailbox.
19609 Defaults to @samp{"no"}.
19612 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
19613 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
19614 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
19615 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
19616 Defaults to @samp{()}.
19623 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
19624 Base directory where to store runtime data.
19625 Defaults to @samp{"/var/run/dovecot/"}.
19628 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
19629 Greeting message for clients.
19630 Defaults to @samp{"Dovecot ready."}.
19633 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
19634 List of trusted network ranges. Connections from these IPs are
19635 allowed to override their IP addresses and ports (for logging and for
19636 authentication checks). @samp{disable-plaintext-auth} is also ignored
19637 for these networks. Typically you would specify your IMAP proxy servers
19639 Defaults to @samp{()}.
19642 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
19643 List of login access check sockets (e.g.@: tcpwrap).
19644 Defaults to @samp{()}.
19647 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
19648 Show more verbose process titles (in ps). Currently shows user name
19649 and IP address. Useful for seeing who is actually using the IMAP
19650 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
19652 Defaults to @samp{#f}.
19655 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
19656 Should all processes be killed when Dovecot master process shuts down.
19657 Setting this to @code{#f} means that Dovecot can be upgraded without
19658 forcing existing client connections to close (although that could also
19659 be a problem if the upgrade is e.g.@: due to a security fix).
19660 Defaults to @samp{#t}.
19663 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
19664 If non-zero, run mail commands via this many connections to doveadm
19665 server, instead of running them directly in the same process.
19666 Defaults to @samp{0}.
19669 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
19670 UNIX socket or host:port used for connecting to doveadm server.
19671 Defaults to @samp{"doveadm-server"}.
19674 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
19675 List of environment variables that are preserved on Dovecot startup
19676 and passed down to all of its child processes. You can also give
19677 key=value pairs to always set specific settings.
19680 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
19681 Disable LOGIN command and all other plaintext authentications unless
19682 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
19683 matches the local IP (i.e.@: you're connecting from the same computer),
19684 the connection is considered secure and plaintext authentication is
19685 allowed. See also ssl=required setting.
19686 Defaults to @samp{#t}.
19689 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
19690 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
19691 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
19692 for caching to be used.
19693 Defaults to @samp{0}.
19696 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
19697 Time to live for cached data. After TTL expires the cached record
19698 is no longer used, *except* if the main database lookup returns internal
19699 failure. We also try to handle password changes automatically: If
19700 user's previous authentication was successful, but this one wasn't, the
19701 cache isn't used. For now this works only with plaintext
19703 Defaults to @samp{"1 hour"}.
19706 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
19707 TTL for negative hits (user not found, password mismatch).
19708 0 disables caching them completely.
19709 Defaults to @samp{"1 hour"}.
19712 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
19713 List of realms for SASL authentication mechanisms that need them.
19714 You can leave it empty if you don't want to support multiple realms.
19715 Many clients simply use the first one listed here, so keep the default
19717 Defaults to @samp{()}.
19720 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
19721 Default realm/domain to use if none was specified. This is used for
19722 both SASL realms and appending @@domain to username in plaintext
19724 Defaults to @samp{""}.
19727 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
19728 List of allowed characters in username. If the user-given username
19729 contains a character not listed in here, the login automatically fails.
19730 This is just an extra check to make sure user can't exploit any
19731 potential quote escaping vulnerabilities with SQL/LDAP databases. If
19732 you want to allow all characters, set this value to empty.
19733 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
19736 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
19737 Username character translations before it's looked up from
19738 databases. The value contains series of from -> to characters. For
19739 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
19740 translated to @samp{@@}.
19741 Defaults to @samp{""}.
19744 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
19745 Username formatting before it's looked up from databases. You can
19746 use the standard variables here, e.g.@: %Lu would lowercase the username,
19747 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
19748 change the @samp{@@} into @samp{-AT-}. This translation is done after
19749 @samp{auth-username-translation} changes.
19750 Defaults to @samp{"%Lu"}.
19753 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
19754 If you want to allow master users to log in by specifying the master
19755 username within the normal username string (i.e.@: not using SASL
19756 mechanism's support for it), you can specify the separator character
19757 here. The format is then <username><separator><master username>.
19758 UW-IMAP uses @samp{*} as the separator, so that could be a good
19760 Defaults to @samp{""}.
19763 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
19764 Username to use for users logging in with ANONYMOUS SASL
19766 Defaults to @samp{"anonymous"}.
19769 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
19770 Maximum number of dovecot-auth worker processes. They're used to
19771 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
19772 They're automatically created and destroyed as needed.
19773 Defaults to @samp{30}.
19776 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
19777 Host name to use in GSSAPI principal names. The default is to use
19778 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
19779 allow all keytab entries.
19780 Defaults to @samp{""}.
19783 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
19784 Kerberos keytab to use for the GSSAPI mechanism. Will use the
19785 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
19786 need to change the auth service to run as root to be able to read this
19788 Defaults to @samp{""}.
19791 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
19792 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
19793 and @samp{ntlm-auth} helper.
19794 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
19795 Defaults to @samp{#f}.
19798 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
19799 Path for Samba's @samp{ntlm-auth} helper binary.
19800 Defaults to @samp{"/usr/bin/ntlm_auth"}.
19803 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
19804 Time to delay before replying to failed authentications.
19805 Defaults to @samp{"2 secs"}.
19808 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
19809 Require a valid SSL client certificate or the authentication
19811 Defaults to @samp{#f}.
19814 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
19815 Take the username from client's SSL certificate, using
19816 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
19818 Defaults to @samp{#f}.
19821 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
19822 List of wanted authentication mechanisms. Supported mechanisms are:
19823 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
19824 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
19825 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
19826 @samp{disable-plaintext-auth} setting.
19829 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
19830 List of IPs or hostnames to all director servers, including ourself.
19831 Ports can be specified as ip:port. The default port is the same as what
19832 director service's @samp{inet-listener} is using.
19833 Defaults to @samp{()}.
19836 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
19837 List of IPs or hostnames to all backend mail servers. Ranges are
19838 allowed too, like 10.0.0.10-10.0.0.30.
19839 Defaults to @samp{()}.
19842 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
19843 How long to redirect users to a specific server after it no longer
19844 has any connections.
19845 Defaults to @samp{"15 min"}.
19848 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
19849 How the username is translated before being hashed. Useful values
19850 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
19851 are shared within domain.
19852 Defaults to @samp{"%Lu"}.
19855 @deftypevr {@code{dovecot-configuration} parameter} string log-path
19856 Log file to use for error messages. @samp{syslog} logs to syslog,
19857 @samp{/dev/stderr} logs to stderr.
19858 Defaults to @samp{"syslog"}.
19861 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
19862 Log file to use for informational messages. Defaults to
19864 Defaults to @samp{""}.
19867 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
19868 Log file to use for debug messages. Defaults to
19869 @samp{info-log-path}.
19870 Defaults to @samp{""}.
19873 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
19874 Syslog facility to use if you're logging to syslog. Usually if you
19875 don't want to use @samp{mail}, you'll use local0..local7. Also other
19876 standard facilities are supported.
19877 Defaults to @samp{"mail"}.
19880 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
19881 Log unsuccessful authentication attempts and the reasons why they
19883 Defaults to @samp{#f}.
19886 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
19887 In case of password mismatches, log the attempted password. Valid
19888 values are no, plain and sha1. sha1 can be useful for detecting brute
19889 force password attempts vs. user simply trying the same password over
19890 and over again. You can also truncate the value to n chars by appending
19891 ":n" (e.g.@: sha1:6).
19892 Defaults to @samp{"no"}.
19895 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
19896 Even more verbose logging for debugging purposes. Shows for example
19898 Defaults to @samp{#f}.
19901 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
19902 In case of password mismatches, log the passwords and used scheme so
19903 the problem can be debugged. Enabling this also enables
19905 Defaults to @samp{#f}.
19908 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
19909 Enable mail process debugging. This can help you figure out why
19910 Dovecot isn't finding your mails.
19911 Defaults to @samp{#f}.
19914 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
19915 Show protocol level SSL errors.
19916 Defaults to @samp{#f}.
19919 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
19920 Prefix for each line written to log file. % codes are in
19921 strftime(3) format.
19922 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
19925 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
19926 List of elements we want to log. The elements which have a
19927 non-empty variable value are joined together to form a comma-separated
19931 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
19932 Login log format. %s contains @samp{login-log-format-elements}
19933 string, %$ contains the data we want to log.
19934 Defaults to @samp{"%$: %s"}.
19937 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
19938 Log prefix for mail processes. See doc/wiki/Variables.txt for list
19939 of possible variables you can use.
19940 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
19943 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
19944 Format to use for logging mail deliveries. You can use variables:
19947 Delivery status message (e.g.@: @samp{saved to INBOX})
19959 Defaults to @samp{"msgid=%m: %$"}.
19962 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
19963 Location for users' mailboxes. The default is empty, which means
19964 that Dovecot tries to find the mailboxes automatically. This won't work
19965 if the user doesn't yet have any mail, so you should explicitly tell
19966 Dovecot the full location.
19968 If you're using mbox, giving a path to the INBOX
19969 file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
19970 where the other mailboxes are kept. This is called the @emph{root mail
19971 directory}, and it must be the first path given in the
19972 @samp{mail-location} setting.
19974 There are a few special variables you can use, e.g.:
19980 user part in user@@domain, same as %u if there's no domain
19982 domain part in user@@domain, empty if there's no domain
19987 See doc/wiki/Variables.txt for full list. Some examples:
19989 @item maildir:~/Maildir
19990 @item mbox:~/mail:INBOX=/var/mail/%u
19991 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
19993 Defaults to @samp{""}.
19996 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
19997 System user and group used to access mails. If you use multiple,
19998 userdb can override these by returning uid or gid fields. You can use
19999 either numbers or names. <doc/wiki/UserIds.txt>.
20000 Defaults to @samp{""}.
20003 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
20005 Defaults to @samp{""}.
20008 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
20009 Group to enable temporarily for privileged operations. Currently
20010 this is used only with INBOX when either its initial creation or
20011 dotlocking fails. Typically this is set to @samp{"mail"} to give access to
20013 Defaults to @samp{""}.
20016 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
20017 Grant access to these supplementary groups for mail processes.
20018 Typically these are used to set up access to shared mailboxes. Note
20019 that it may be dangerous to set these if users can create symlinks
20020 (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
20021 could allow a user to delete others' mailboxes, or @code{ln -s
20022 /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
20026 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
20027 Allow full file system access to clients. There's no access checks
20028 other than what the operating system does for the active UID/GID. It
20029 works with both maildir and mboxes, allowing you to prefix mailboxes
20030 names with e.g.@: @file{/path/} or @file{~user/}.
20031 Defaults to @samp{#f}.
20034 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
20035 Don't use @code{mmap()} at all. This is required if you store indexes to
20036 shared file systems (NFS or clustered file system).
20037 Defaults to @samp{#f}.
20040 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
20041 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
20042 supports @samp{O_EXCL} since version 3, so this should be safe to use
20043 nowadays by default.
20044 Defaults to @samp{#t}.
20047 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
20048 When to use fsync() or fdatasync() calls:
20051 Whenever necessary to avoid losing important data
20053 Useful with e.g.@: NFS when @code{write()}s are delayed
20055 Never use it (best performance, but crashes can lose data).
20057 Defaults to @samp{"optimized"}.
20060 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
20061 Mail storage exists in NFS. Set this to yes to make Dovecot flush
20062 NFS caches whenever needed. If you're using only a single mail server
20064 Defaults to @samp{#f}.
20067 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
20068 Mail index files also exist in NFS. Setting this to yes requires
20069 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
20070 Defaults to @samp{#f}.
20073 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
20074 Locking method for index files. Alternatives are fcntl, flock and
20075 dotlock. Dotlocking uses some tricks which may create more disk I/O
20076 than other locking methods. NFS users: flock doesn't work, remember to
20077 change @samp{mmap-disable}.
20078 Defaults to @samp{"fcntl"}.
20081 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
20082 Directory in which LDA/LMTP temporarily stores incoming mails >128
20084 Defaults to @samp{"/tmp"}.
20087 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
20088 Valid UID range for users. This is mostly to make sure that users can't
20089 log in as daemons or other system users. Note that denying root logins is
20090 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
20092 Defaults to @samp{500}.
20095 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
20097 Defaults to @samp{0}.
20100 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
20101 Valid GID range for users. Users having non-valid GID as primary group ID
20102 aren't allowed to log in. If user belongs to supplementary groups with
20103 non-valid GIDs, those groups are not set.
20104 Defaults to @samp{1}.
20107 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
20109 Defaults to @samp{0}.
20112 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
20113 Maximum allowed length for mail keyword name. It's only forced when
20114 trying to create new keywords.
20115 Defaults to @samp{50}.
20118 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
20119 List of directories under which chrooting is allowed for mail
20120 processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
20121 too). This setting doesn't affect @samp{login-chroot}
20122 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
20123 @samp{/./} in home dirs are ignored. WARNING: Never add directories here
20124 which local users can modify, that may lead to root exploit. Usually
20125 this should be done only if you don't allow shell access for users.
20126 <doc/wiki/Chrooting.txt>.
20127 Defaults to @samp{()}.
20130 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
20131 Default chroot directory for mail processes. This can be overridden
20132 for specific users in user database by giving @samp{/./} in user's home
20133 directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
20134 there is no real need to do chrooting, Dovecot doesn't allow users to
20135 access files outside their mail directory anyway. If your home
20136 directories are prefixed with the chroot directory, append @samp{/.} to
20137 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
20138 Defaults to @samp{""}.
20141 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
20142 UNIX socket path to master authentication server to find users.
20143 This is used by imap (for shared users) and lda.
20144 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
20147 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
20148 Directory where to look up mail plugins.
20149 Defaults to @samp{"/usr/lib/dovecot"}.
20152 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
20153 List of plugins to load for all services. Plugins specific to IMAP,
20154 LDA, etc.@: are added to this list in their own .conf files.
20155 Defaults to @samp{()}.
20158 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
20159 The minimum number of mails in a mailbox before updates are done to
20160 cache file. This allows optimizing Dovecot's behavior to do less disk
20161 writes at the cost of more disk reads.
20162 Defaults to @samp{0}.
20165 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
20166 When IDLE command is running, mailbox is checked once in a while to
20167 see if there are any new mails or other changes. This setting defines
20168 the minimum time to wait between those checks. Dovecot can also use
20169 dnotify, inotify and kqueue to find out immediately when changes
20171 Defaults to @samp{"30 secs"}.
20174 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
20175 Save mails with CR+LF instead of plain LF. This makes sending those
20176 mails take less CPU, especially with sendfile() syscall with Linux and
20177 FreeBSD. But it also creates a bit more disk I/O which may just make it
20178 slower. Also note that if other software reads the mboxes/maildirs,
20179 they may handle the extra CRs wrong and cause problems.
20180 Defaults to @samp{#f}.
20183 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
20184 By default LIST command returns all entries in maildir beginning
20185 with a dot. Enabling this option makes Dovecot return only entries
20186 which are directories. This is done by stat()ing each entry, so it
20187 causes more disk I/O.
20188 (For systems setting struct @samp{dirent->d_type} this check is free
20189 and it's done always regardless of this setting).
20190 Defaults to @samp{#f}.
20193 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
20194 When copying a message, do it with hard links whenever possible.
20195 This makes the performance much better, and it's unlikely to have any
20197 Defaults to @samp{#t}.
20200 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
20201 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
20202 directory only when its mtime changes unexpectedly or when we can't find
20203 the mail otherwise.
20204 Defaults to @samp{#f}.
20207 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
20208 Which locking methods to use for locking mbox. There are four
20213 Create <mailbox>.lock file. This is the oldest and most NFS-safe
20214 solution. If you want to use /var/mail/ like directory, the users will
20215 need write access to that directory.
20217 Same as dotlock, but if it fails because of permissions or because there
20218 isn't enough disk space, just skip it.
20220 Use this if possible. Works with NFS too if lockd is used.
20222 May not exist in all systems. Doesn't work with NFS.
20224 May not exist in all systems. Doesn't work with NFS.
20227 You can use multiple locking methods; if you do the order they're declared
20228 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
20229 locking methods as well. Some operating systems don't allow using some of
20230 them simultaneously.
20233 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
20237 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
20238 Maximum time to wait for lock (all of them) before aborting.
20239 Defaults to @samp{"5 mins"}.
20242 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
20243 If dotlock exists but the mailbox isn't modified in any way,
20244 override the lock file after this much time.
20245 Defaults to @samp{"2 mins"}.
20248 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
20249 When mbox changes unexpectedly we have to fully read it to find out
20250 what changed. If the mbox is large this can take a long time. Since
20251 the change is usually just a newly appended mail, it'd be faster to
20252 simply read the new mails. If this setting is enabled, Dovecot does
20253 this but still safely fallbacks to re-reading the whole mbox file
20254 whenever something in mbox isn't how it's expected to be. The only real
20255 downside to this setting is that if some other MUA changes message
20256 flags, Dovecot doesn't notice it immediately. Note that a full sync is
20257 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
20258 Defaults to @samp{#t}.
20261 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
20262 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
20263 EXAMINE, EXPUNGE or CHECK commands. If this is set,
20264 @samp{mbox-dirty-syncs} is ignored.
20265 Defaults to @samp{#f}.
20268 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
20269 Delay writing mbox headers until doing a full write sync (EXPUNGE
20270 and CHECK commands and when closing the mailbox). This is especially
20271 useful for POP3 where clients often delete all mails. The downside is
20272 that our changes aren't immediately visible to other MUAs.
20273 Defaults to @samp{#t}.
20276 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
20277 If mbox size is smaller than this (e.g.@: 100k), don't write index
20278 files. If an index file already exists it's still read, just not
20280 Defaults to @samp{0}.
20283 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
20284 Maximum dbox file size until it's rotated.
20285 Defaults to @samp{10000000}.
20288 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
20289 Maximum dbox file age until it's rotated. Typically in days. Day
20290 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
20292 Defaults to @samp{"1d"}.
20295 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
20296 When creating new mdbox files, immediately preallocate their size to
20297 @samp{mdbox-rotate-size}. This setting currently works only in Linux
20298 with some file systems (ext4, xfs).
20299 Defaults to @samp{#f}.
20302 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
20303 sdbox and mdbox support saving mail attachments to external files,
20304 which also allows single instance storage for them. Other backends
20305 don't support this for now.
20307 WARNING: This feature hasn't been tested much yet. Use at your own risk.
20309 Directory root where to store mail attachments. Disabled, if empty.
20310 Defaults to @samp{""}.
20313 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
20314 Attachments smaller than this aren't saved externally. It's also
20315 possible to write a plugin to disable saving specific attachments
20317 Defaults to @samp{128000}.
20320 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
20321 File system backend to use for saving attachments:
20324 No SiS done by Dovecot (but this might help FS's own deduplication)
20326 SiS with immediate byte-by-byte comparison during saving
20327 @item sis-queue posix
20328 SiS with delayed comparison and deduplication.
20330 Defaults to @samp{"sis posix"}.
20333 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
20334 Hash format to use in attachment filenames. You can add any text and
20335 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
20336 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
20337 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
20338 Defaults to @samp{"%@{sha1@}"}.
20341 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
20343 Defaults to @samp{100}.
20346 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
20348 Defaults to @samp{1000}.
20351 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
20352 Default VSZ (virtual memory size) limit for service processes.
20353 This is mainly intended to catch and kill processes that leak memory
20354 before they eat up everything.
20355 Defaults to @samp{256000000}.
20358 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
20359 Login user is internally used by login processes. This is the most
20360 untrusted user in Dovecot system. It shouldn't have access to anything
20362 Defaults to @samp{"dovenull"}.
20365 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
20366 Internal user is used by unprivileged processes. It should be
20367 separate from login user, so that login processes can't disturb other
20369 Defaults to @samp{"dovecot"}.
20372 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
20373 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
20374 Defaults to @samp{"required"}.
20377 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
20378 PEM encoded X.509 SSL/TLS certificate (public key).
20379 Defaults to @samp{"</etc/dovecot/default.pem"}.
20382 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
20383 PEM encoded SSL/TLS private key. The key is opened before
20384 dropping root privileges, so keep the key file unreadable by anyone but
20386 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
20389 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
20390 If key file is password protected, give the password here.
20391 Alternatively give it when starting dovecot with -p parameter. Since
20392 this file is often world-readable, you may want to place this setting
20393 instead to a different.
20394 Defaults to @samp{""}.
20397 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
20398 PEM encoded trusted certificate authority. Set this only if you
20399 intend to use @samp{ssl-verify-client-cert? #t}. The file should
20400 contain the CA certificate(s) followed by the matching
20401 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
20402 Defaults to @samp{""}.
20405 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
20406 Require that CRL check succeeds for client certificates.
20407 Defaults to @samp{#t}.
20410 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
20411 Request client to send a certificate. If you also want to require
20412 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
20413 Defaults to @samp{#f}.
20416 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
20417 Which field from certificate to use for username. commonName and
20418 x500UniqueIdentifier are the usual choices. You'll also need to set
20419 @samp{auth-ssl-username-from-cert? #t}.
20420 Defaults to @samp{"commonName"}.
20423 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
20424 Minimum SSL protocol version to accept.
20425 Defaults to @samp{"TLSv1"}.
20428 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
20429 SSL ciphers to use.
20430 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
20433 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
20434 SSL crypto device to use, for valid values run "openssl engine".
20435 Defaults to @samp{""}.
20438 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
20439 Address to use when sending rejection mails.
20440 %d expands to recipient domain.
20441 Defaults to @samp{"postmaster@@%d"}.
20444 @deftypevr {@code{dovecot-configuration} parameter} string hostname
20445 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
20446 and in LMTP replies. Default is the system's real hostname@@domain.
20447 Defaults to @samp{""}.
20450 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
20451 If user is over quota, return with temporary failure instead of
20453 Defaults to @samp{#f}.
20456 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
20457 Binary to use for sending mails.
20458 Defaults to @samp{"/usr/sbin/sendmail"}.
20461 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
20462 If non-empty, send mails via this SMTP host[:port] instead of
20464 Defaults to @samp{""}.
20467 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
20468 Subject: header to use for rejection mails. You can use the same
20469 variables as for @samp{rejection-reason} below.
20470 Defaults to @samp{"Rejected: %s"}.
20473 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
20474 Human readable error message for rejection mails. You can use
20487 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
20490 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
20491 Delimiter character between local-part and detail in email
20493 Defaults to @samp{"+"}.
20496 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
20497 Header where the original recipient address (SMTP's RCPT TO:
20498 address) is taken from if not available elsewhere. With dovecot-lda -a
20499 parameter overrides this. A commonly used header for this is
20501 Defaults to @samp{""}.
20504 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
20505 Should saving a mail to a nonexistent mailbox automatically create
20507 Defaults to @samp{#f}.
20510 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
20511 Should automatically created mailboxes be also automatically
20513 Defaults to @samp{#f}.
20516 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
20517 Maximum IMAP command line length. Some clients generate very long
20518 command lines with huge mailboxes, so you may need to raise this if you
20519 get "Too long argument" or "IMAP command line too large" errors
20521 Defaults to @samp{64000}.
20524 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
20525 IMAP logout format string:
20528 total number of bytes read from client
20530 total number of bytes sent to client.
20532 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
20533 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@}"}.
20536 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
20537 Override the IMAP CAPABILITY response. If the value begins with '+',
20538 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
20539 Defaults to @samp{""}.
20542 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
20543 How long to wait between "OK Still here" notifications when client
20545 Defaults to @samp{"2 mins"}.
20548 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
20549 ID field names and values to send to clients. Using * as the value
20550 makes Dovecot use the default value. The following fields have default
20551 values currently: name, version, os, os-version, support-url,
20553 Defaults to @samp{""}.
20556 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
20557 ID fields sent by client to log. * means everything.
20558 Defaults to @samp{""}.
20561 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
20562 Workarounds for various client bugs:
20565 @item delay-newmail
20566 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
20567 CHECK commands. Some clients ignore them otherwise, for example OSX
20568 Mail (<v2.1). Outlook Express breaks more badly though, without this it
20569 may show user "Message no longer in server" errors. Note that OE6
20570 still breaks even with this workaround if synchronization is set to
20573 @item tb-extra-mailbox-sep
20574 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
20575 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
20576 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
20578 @item tb-lsub-flags
20579 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
20580 This makes Thunderbird realize they aren't selectable and show them
20581 greyed out, instead of only later giving "not selectable" popup error.
20583 Defaults to @samp{()}.
20586 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
20587 Host allowed in URLAUTH URLs sent by client. "*" allows all.
20588 Defaults to @samp{""}.
20592 Whew! Lots of configuration options. The nice thing about it though is
20593 that Guix has a complete interface to Dovecot's configuration
20594 language. This allows not only a nice way to declare configurations,
20595 but also offers reflective capabilities as well: users can write code to
20596 inspect and transform configurations from within Scheme.
20598 However, it could be that you just want to get a @code{dovecot.conf} up
20599 and running. In that case, you can pass an
20600 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
20601 @code{dovecot-service}. As its name indicates, an opaque configuration
20602 does not have easy reflective capabilities.
20604 Available @code{opaque-dovecot-configuration} fields are:
20606 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
20607 The dovecot package.
20610 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
20611 The contents of the @code{dovecot.conf}, as a string.
20614 For example, if your @code{dovecot.conf} is just the empty string, you
20615 could instantiate a dovecot service like this:
20618 (dovecot-service #:config
20619 (opaque-dovecot-configuration
20623 @subsubheading OpenSMTPD Service
20625 @deffn {Scheme Variable} opensmtpd-service-type
20626 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
20627 service, whose value should be an @code{opensmtpd-configuration} object
20628 as in this example:
20631 (service opensmtpd-service-type
20632 (opensmtpd-configuration
20633 (config-file (local-file "./my-smtpd.conf"))))
20637 @deftp {Data Type} opensmtpd-configuration
20638 Data type representing the configuration of opensmtpd.
20641 @item @code{package} (default: @var{opensmtpd})
20642 Package object of the OpenSMTPD SMTP server.
20644 @item @code{config-file} (default: @code{%default-opensmtpd-file})
20645 File-like object of the OpenSMTPD configuration file to use. By default
20646 it listens on the loopback network interface, and allows for mail from
20647 users and daemons on the local machine, as well as permitting email to
20648 remote servers. Run @command{man smtpd.conf} for more information.
20653 @subsubheading Exim Service
20655 @cindex mail transfer agent (MTA)
20656 @cindex MTA (mail transfer agent)
20659 @deffn {Scheme Variable} exim-service-type
20660 This is the type of the @uref{https://exim.org, Exim} mail transfer
20661 agent (MTA), whose value should be an @code{exim-configuration} object
20662 as in this example:
20665 (service exim-service-type
20666 (exim-configuration
20667 (config-file (local-file "./my-exim.conf"))))
20671 In order to use an @code{exim-service-type} service you must also have a
20672 @code{mail-aliases-service-type} service present in your
20673 @code{operating-system} (even if it has no aliases).
20675 @deftp {Data Type} exim-configuration
20676 Data type representing the configuration of exim.
20679 @item @code{package} (default: @var{exim})
20680 Package object of the Exim server.
20682 @item @code{config-file} (default: @code{#f})
20683 File-like object of the Exim configuration file to use. If its value is
20684 @code{#f} then use the default configuration file from the package
20685 provided in @code{package}. The resulting configuration file is loaded
20686 after setting the @code{exim_user} and @code{exim_group} configuration
20692 @subsubheading Getmail service
20697 @deffn {Scheme Variable} getmail-service-type
20698 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
20699 mail retriever, whose value should be an @code{getmail-configuration}.
20702 Available @code{getmail-configuration} fields are:
20704 @deftypevr {@code{getmail-configuration} parameter} symbol name
20705 A symbol to identify the getmail service.
20707 Defaults to @samp{"unset"}.
20711 @deftypevr {@code{getmail-configuration} parameter} package package
20712 The getmail package to use.
20716 @deftypevr {@code{getmail-configuration} parameter} string user
20717 The user to run getmail as.
20719 Defaults to @samp{"getmail"}.
20723 @deftypevr {@code{getmail-configuration} parameter} string group
20724 The group to run getmail as.
20726 Defaults to @samp{"getmail"}.
20730 @deftypevr {@code{getmail-configuration} parameter} string directory
20731 The getmail directory to use.
20733 Defaults to @samp{"/var/lib/getmail/default"}.
20737 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
20738 The getmail configuration file to use.
20740 Available @code{getmail-configuration-file} fields are:
20742 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
20743 What mail account to retrieve mail from, and how to access that account.
20745 Available @code{getmail-retriever-configuration} fields are:
20747 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
20748 The type of mail retriever to use. Valid values include @samp{passwd}
20751 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
20755 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
20756 Username to login to the mail server with.
20758 Defaults to @samp{unset}.
20762 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
20763 Username to login to the mail server with.
20765 Defaults to @samp{unset}.
20769 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
20770 Port number to connect to.
20772 Defaults to @samp{#f}.
20776 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
20777 Override fields from passwd.
20779 Defaults to @samp{""}.
20783 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
20784 Override fields from passwd.
20786 Defaults to @samp{()}.
20790 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
20791 PEM-formatted key file to use for the TLS negotiation.
20793 Defaults to @samp{""}.
20797 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
20798 PEM-formatted certificate file to use for the TLS negotiation.
20800 Defaults to @samp{""}.
20804 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
20805 CA certificates to use.
20807 Defaults to @samp{""}.
20811 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
20812 Extra retriever parameters.
20814 Defaults to @samp{()}.
20820 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
20821 What to do with retrieved messages.
20823 Available @code{getmail-destination-configuration} fields are:
20825 @deftypevr {@code{getmail-destination-configuration} parameter} string type
20826 The type of mail destination. Valid values include @samp{Maildir},
20827 @samp{Mboxrd} and @samp{MDA_external}.
20829 Defaults to @samp{unset}.
20833 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
20834 The path option for the mail destination. The behaviour depends on the
20837 Defaults to @samp{""}.
20841 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
20842 Extra destination parameters
20844 Defaults to @samp{()}.
20850 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
20853 Available @code{getmail-options-configuration} fields are:
20855 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
20856 If set to @samp{0}, getmail will only print warnings and errors. A
20857 value of @samp{1} means that messages will be printed about retrieving
20858 and deleting messages. If set to @samp{2}, getmail will print messages
20859 about each of it's actions.
20861 Defaults to @samp{1}.
20865 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
20866 If true, getmail will retrieve all available messages. Otherwise it
20867 will only retrieve messages it hasn't seen previously.
20869 Defaults to @samp{#t}.
20873 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
20874 If set to true, messages will be deleted from the server after
20875 retrieving and successfully delivering them. Otherwise, messages will
20876 be left on the server.
20878 Defaults to @samp{#f}.
20882 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
20883 Getmail will delete messages this number of days after seeing them, if
20884 they have been delivered. This means messages will be left on the
20885 server this number of days after delivering them. A value of @samp{0}
20886 disabled this feature.
20888 Defaults to @samp{0}.
20892 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
20893 Delete messages larger than this of bytes after retrieving them, even if
20894 the delete and delete-after options are disabled. A value of @samp{0}
20895 disables this feature.
20897 Defaults to @samp{0}.
20901 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
20902 Retrieve messages totalling up to this number of bytes before closing
20903 the session with the server. A value of @samp{0} disables this feature.
20905 Defaults to @samp{0}.
20909 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
20910 Don't retrieve messages larger than this number of bytes. A value of
20911 @samp{0} disables this feature.
20913 Defaults to @samp{0}.
20917 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
20918 If true, getmail will add a Delivered-To header to messages.
20920 Defaults to @samp{#t}.
20924 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
20925 If set, getmail adds a Received header to the messages.
20927 Defaults to @samp{#t}.
20931 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
20932 Getmail will record a log of its actions to the named file. A value of
20933 @samp{""} disables this feature.
20935 Defaults to @samp{""}.
20939 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
20940 If true, getmail will record a log of its actions using the system
20943 Defaults to @samp{#f}.
20947 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
20948 If true, getmail will log information about messages not retrieved and
20949 the reason for not retrieving them, as well as starting and ending
20952 Defaults to @samp{#f}.
20956 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
20957 Extra options to include.
20959 Defaults to @samp{()}.
20967 @deftypevr {@code{getmail-configuration} parameter} list idle
20968 A list of mailboxes that getmail should wait on the server for new mail
20969 notifications. This depends on the server supporting the IDLE
20972 Defaults to @samp{()}.
20976 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
20977 Environment variables to set for getmail.
20979 Defaults to @samp{()}.
20983 @subsubheading Mail Aliases Service
20985 @cindex email aliases
20986 @cindex aliases, for email addresses
20988 @deffn {Scheme Variable} mail-aliases-service-type
20989 This is the type of the service which provides @code{/etc/aliases},
20990 specifying how to deliver mail to users on this system.
20993 (service mail-aliases-service-type
20994 '(("postmaster" "bob")
20995 ("bob" "bob@@example.com" "bob@@example2.com")))
20999 The configuration for a @code{mail-aliases-service-type} service is an
21000 association list denoting how to deliver mail that comes to this
21001 system. Each entry is of the form @code{(alias addresses ...)}, with
21002 @code{alias} specifying the local alias and @code{addresses} specifying
21003 where to deliver this user's mail.
21005 The aliases aren't required to exist as users on the local system. In
21006 the above example, there doesn't need to be a @code{postmaster} entry in
21007 the @code{operating-system}'s @code{user-accounts} in order to deliver
21008 the @code{postmaster} mail to @code{bob} (which subsequently would
21009 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
21011 @subsubheading GNU Mailutils IMAP4 Daemon
21012 @cindex GNU Mailutils IMAP4 Daemon
21014 @deffn {Scheme Variable} imap4d-service-type
21015 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
21016 mailutils, GNU Mailutils Manual}), whose value should be an
21017 @code{imap4d-configuration} object as in this example:
21020 (service imap4d-service-type
21021 (imap4d-configuration
21022 (config-file (local-file "imap4d.conf"))))
21026 @deftp {Data Type} imap4d-configuration
21027 Data type representing the configuration of @command{imap4d}.
21030 @item @code{package} (default: @code{mailutils})
21031 The package that provides @command{imap4d}.
21033 @item @code{config-file} (default: @code{%default-imap4d-config-file})
21034 File-like object of the configuration file to use, by default it will listen
21035 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
21036 Mailutils Manual}, for details.
21041 @node Messaging Services
21042 @subsection Messaging Services
21047 The @code{(gnu services messaging)} module provides Guix service
21048 definitions for messaging services. Currently it provides the following
21051 @subsubheading Prosody Service
21053 @deffn {Scheme Variable} prosody-service-type
21054 This is the type for the @uref{https://prosody.im, Prosody XMPP
21055 communication server}. Its value must be a @code{prosody-configuration}
21056 record as in this example:
21059 (service prosody-service-type
21060 (prosody-configuration
21061 (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
21064 (int-component-configuration
21065 (hostname "conference.example.net")
21067 (mod-muc (mod-muc-configuration)))))
21070 (virtualhost-configuration
21071 (domain "example.net"))))))
21074 See below for details about @code{prosody-configuration}.
21078 By default, Prosody does not need much configuration. Only one
21079 @code{virtualhosts} field is needed: it specifies the domain you wish
21082 You can perform various sanity checks on the generated configuration
21083 with the @code{prosodyctl check} command.
21085 Prosodyctl will also help you to import certificates from the
21086 @code{letsencrypt} directory so that the @code{prosody} user can access
21087 them. See @url{https://prosody.im/doc/letsencrypt}.
21090 prosodyctl --root cert import /etc/letsencrypt/live
21093 The available configuration parameters follow. Each parameter
21094 definition is preceded by its type; for example, @samp{string-list foo}
21095 indicates that the @code{foo} parameter should be specified as a list of
21096 strings. Types starting with @code{maybe-} denote parameters that won't
21097 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
21099 There is also a way to specify the configuration as a string, if you
21100 have an old @code{prosody.cfg.lua} file that you want to port over from
21101 some other system; see the end for more details.
21103 The @code{file-object} type designates either a file-like object
21104 (@pxref{G-Expressions, file-like objects}) or a file name.
21106 @c The following documentation was initially generated by
21107 @c (generate-documentation) in (gnu services messaging). Manually maintained
21108 @c documentation is better, so we shouldn't hesitate to edit below as
21109 @c needed. However if the change you want to make to this documentation
21110 @c can be done in an automated way, it's probably easier to change
21111 @c (generate-documentation) than to make it below and have to deal with
21112 @c the churn as Prosody updates.
21114 Available @code{prosody-configuration} fields are:
21116 @deftypevr {@code{prosody-configuration} parameter} package prosody
21117 The Prosody package.
21120 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
21121 Location of the Prosody data storage directory. See
21122 @url{https://prosody.im/doc/configure}.
21123 Defaults to @samp{"/var/lib/prosody"}.
21126 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
21127 Additional plugin directories. They are searched in all the specified
21128 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
21129 Defaults to @samp{()}.
21132 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
21133 Every virtual host and component needs a certificate so that clients and
21134 servers can securely verify its identity. Prosody will automatically load
21135 certificates/keys from the directory specified here.
21136 Defaults to @samp{"/etc/prosody/certs"}.
21139 @deftypevr {@code{prosody-configuration} parameter} string-list admins
21140 This is a list of accounts that are admins for the server. Note that you
21141 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
21142 @url{https://prosody.im/doc/creating_accounts}.
21143 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
21144 Defaults to @samp{()}.
21147 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
21148 Enable use of libevent for better performance under high load. See
21149 @url{https://prosody.im/doc/libevent}.
21150 Defaults to @samp{#f}.
21153 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
21154 This is the list of modules Prosody will load on startup. It looks for
21155 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
21156 Documentation on modules can be found at:
21157 @url{https://prosody.im/doc/modules}.
21158 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
21161 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
21162 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
21163 should you want to disable them then add them to this list.
21164 Defaults to @samp{()}.
21167 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
21168 Path to a text file where the shared groups are defined. If this path is
21169 empty then @samp{mod_groups} does nothing. See
21170 @url{https://prosody.im/doc/modules/mod_groups}.
21171 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
21174 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
21175 Disable account creation by default, for security. See
21176 @url{https://prosody.im/doc/creating_accounts}.
21177 Defaults to @samp{#f}.
21180 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
21181 These are the SSL/TLS-related settings. Most of them are disabled so to
21182 use Prosody's defaults. If you do not completely understand these options, do
21183 not add them to your config, it is easy to lower the security of your server
21184 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
21186 Available @code{ssl-configuration} fields are:
21188 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
21189 This determines what handshake to use.
21192 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
21193 Path to your private key file.
21196 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
21197 Path to your certificate file.
21200 @deftypevr {@code{ssl-configuration} parameter} file-object capath
21201 Path to directory containing root certificates that you wish Prosody to
21202 trust when verifying the certificates of remote servers.
21203 Defaults to @samp{"/etc/ssl/certs"}.
21206 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
21207 Path to a file containing root certificates that you wish Prosody to trust.
21208 Similar to @code{capath} but with all certificates concatenated together.
21211 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
21212 A list of verification options (these mostly map to OpenSSL's
21213 @code{set_verify()} flags).
21216 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
21217 A list of general options relating to SSL/TLS. These map to OpenSSL's
21218 @code{set_options()}. For a full list of options available in LuaSec, see the
21222 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
21223 How long a chain of certificate authorities to check when looking for a
21224 trusted root certificate.
21227 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
21228 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
21229 clients, and in what order.
21232 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
21233 A path to a file containing parameters for Diffie-Hellman key exchange. You
21234 can create such a file with:
21235 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
21238 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
21239 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
21240 @samp{"secp384r1"}.
21243 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
21244 A list of ``extra'' verification options.
21247 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
21248 Password for encrypted private keys.
21253 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
21254 Whether to force all client-to-server connections to be encrypted or not.
21255 See @url{https://prosody.im/doc/modules/mod_tls}.
21256 Defaults to @samp{#f}.
21259 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
21260 Set of mechanisms that will never be offered. See
21261 @url{https://prosody.im/doc/modules/mod_saslauth}.
21262 Defaults to @samp{("DIGEST-MD5")}.
21265 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
21266 Whether to force all server-to-server connections to be encrypted or not.
21267 See @url{https://prosody.im/doc/modules/mod_tls}.
21268 Defaults to @samp{#f}.
21271 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
21272 Whether to require encryption and certificate authentication. This
21273 provides ideal security, but requires servers you communicate with to support
21274 encryption AND present valid, trusted certificates. See
21275 @url{https://prosody.im/doc/s2s#security}.
21276 Defaults to @samp{#f}.
21279 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
21280 Many servers don't support encryption or have invalid or self-signed
21281 certificates. You can list domains here that will not be required to
21282 authenticate using certificates. They will be authenticated using DNS. See
21283 @url{https://prosody.im/doc/s2s#security}.
21284 Defaults to @samp{()}.
21287 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
21288 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
21289 valid certificates for some domains by specifying a list here. See
21290 @url{https://prosody.im/doc/s2s#security}.
21291 Defaults to @samp{()}.
21294 @deftypevr {@code{prosody-configuration} parameter} string authentication
21295 Select the authentication backend to use. The default provider stores
21296 passwords in plaintext and uses Prosody's configured data storage to store the
21297 authentication data. If you do not trust your server please see
21298 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
21299 about using the hashed backend. See also
21300 @url{https://prosody.im/doc/authentication}
21301 Defaults to @samp{"internal_plain"}.
21304 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
21305 Set logging options. Advanced logging configuration is not yet supported
21306 by the Prosody service. See @url{https://prosody.im/doc/logging}.
21307 Defaults to @samp{"*syslog"}.
21310 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
21311 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
21312 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
21315 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
21316 Maximum allowed size of the HTTP body (in bytes).
21319 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
21320 Some modules expose their own URL in various ways. This URL is built
21321 from the protocol, host and port used. If Prosody sits behind a proxy, the
21322 public URL will be @code{http-external-url} instead. See
21323 @url{https://prosody.im/doc/http#external_url}.
21326 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
21327 A host in Prosody is a domain on which user accounts can be created. For
21328 example if you want your users to have addresses like
21329 @samp{"john.smith@@example.com"} then you need to add a host
21330 @samp{"example.com"}. All options in this list will apply only to this host.
21332 Note: the name @emph{virtual} host is used in configuration to avoid confusion with
21333 the actual physical host that Prosody is installed on. A single Prosody
21334 instance can serve many domains, each one defined as a VirtualHost entry in
21335 Prosody's configuration. Conversely a server that hosts a single domain would
21336 have just one VirtualHost entry.
21338 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
21340 Available @code{virtualhost-configuration} fields are:
21342 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:
21343 @deftypevr {@code{virtualhost-configuration} parameter} string domain
21344 Domain you wish Prosody to serve.
21349 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
21350 Components are extra services on a server which are available to clients,
21351 usually on a subdomain of the main server (such as
21352 @samp{"mycomponent.example.com"}). Example components might be chatroom
21353 servers, user directories, or gateways to other protocols.
21355 Internal components are implemented with Prosody-specific plugins. To add an
21356 internal component, you simply fill the hostname field, and the plugin you wish
21357 to use for the component.
21359 See @url{https://prosody.im/doc/components}.
21360 Defaults to @samp{()}.
21362 Available @code{int-component-configuration} fields are:
21364 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:
21365 @deftypevr {@code{int-component-configuration} parameter} string hostname
21366 Hostname of the component.
21369 @deftypevr {@code{int-component-configuration} parameter} string plugin
21370 Plugin you wish to use for the component.
21373 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
21374 Multi-user chat (MUC) is Prosody's module for allowing you to create
21375 hosted chatrooms/conferences for XMPP users.
21377 General information on setting up and using multi-user chatrooms can be found
21378 in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
21379 which you should read if you are new to XMPP chatrooms.
21381 See also @url{https://prosody.im/doc/modules/mod_muc}.
21383 Available @code{mod-muc-configuration} fields are:
21385 @deftypevr {@code{mod-muc-configuration} parameter} string name
21386 The name to return in service discovery responses.
21387 Defaults to @samp{"Prosody Chatrooms"}.
21390 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
21391 If @samp{#t}, this will only allow admins to create new chatrooms.
21392 Otherwise anyone can create a room. The value @samp{"local"} restricts room
21393 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
21394 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
21395 restricts to service administrators only.
21396 Defaults to @samp{#f}.
21399 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
21400 Maximum number of history messages that will be sent to the member that has
21401 just joined the room.
21402 Defaults to @samp{20}.
21409 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
21410 External components use XEP-0114, which most standalone components
21411 support. To add an external component, you simply fill the hostname field. See
21412 @url{https://prosody.im/doc/components}.
21413 Defaults to @samp{()}.
21415 Available @code{ext-component-configuration} fields are:
21417 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:
21418 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
21419 Password which the component will use to log in.
21422 @deftypevr {@code{ext-component-configuration} parameter} string hostname
21423 Hostname of the component.
21428 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
21429 Port(s) Prosody listens on for component connections.
21430 Defaults to @samp{(5347)}.
21433 @deftypevr {@code{prosody-configuration} parameter} string component-interface
21434 Interface Prosody listens on for component connections.
21435 Defaults to @samp{"127.0.0.1"}.
21438 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
21439 Raw content that will be added to the configuration file.
21442 It could be that you just want to get a @code{prosody.cfg.lua}
21443 up and running. In that case, you can pass an
21444 @code{opaque-prosody-configuration} record as the value of
21445 @code{prosody-service-type}. As its name indicates, an opaque configuration
21446 does not have easy reflective capabilities.
21447 Available @code{opaque-prosody-configuration} fields are:
21449 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
21450 The prosody package.
21453 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
21454 The contents of the @code{prosody.cfg.lua} to use.
21457 For example, if your @code{prosody.cfg.lua} is just the empty
21458 string, you could instantiate a prosody service like this:
21461 (service prosody-service-type
21462 (opaque-prosody-configuration
21463 (prosody.cfg.lua "")))
21466 @c end of Prosody auto-generated documentation
21468 @subsubheading BitlBee Service
21470 @cindex IRC (Internet Relay Chat)
21471 @cindex IRC gateway
21472 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
21473 interface to a variety of messaging protocols such as XMPP.
21475 @defvr {Scheme Variable} bitlbee-service-type
21476 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
21477 gateway daemon. Its value is a @code{bitlbee-configuration} (see
21480 To have BitlBee listen on port 6667 on localhost, add this line to your
21484 (service bitlbee-service-type)
21488 @deftp {Data Type} bitlbee-configuration
21489 This is the configuration for BitlBee, with the following fields:
21492 @item @code{interface} (default: @code{"127.0.0.1"})
21493 @itemx @code{port} (default: @code{6667})
21494 Listen on the network interface corresponding to the IP address
21495 specified in @var{interface}, on @var{port}.
21497 When @var{interface} is @code{127.0.0.1}, only local clients can
21498 connect; when it is @code{0.0.0.0}, connections can come from any
21499 networking interface.
21501 @item @code{bitlbee} (default: @code{bitlbee})
21502 The BitlBee package to use.
21504 @item @code{plugins} (default: @code{'()})
21505 List of plugin packages to use---e.g., @code{bitlbee-discord}.
21507 @item @code{extra-settings} (default: @code{""})
21508 Configuration snippet added as-is to the BitlBee configuration file.
21512 @subsubheading Quassel Service
21514 @cindex IRC (Internet Relay Chat)
21515 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
21516 meaning that one or more clients can attach to and detach from the
21519 @defvr {Scheme Variable} quassel-service-type
21520 This is the service type for the @url{https://quassel-irc.org/,Quassel}
21521 IRC backend daemon. Its value is a @code{quassel-configuration}
21525 @deftp {Data Type} quassel-configuration
21526 This is the configuration for Quassel, with the following fields:
21529 @item @code{quassel} (default: @code{quassel})
21530 The Quassel package to use.
21532 @item @code{interface} (default: @code{"::,0.0.0.0"})
21533 @item @code{port} (default: @code{4242})
21534 Listen on the network interface(s) corresponding to the IPv4 or IPv6
21535 interfaces specified in the comma delimited @var{interface}, on
21538 @item @code{loglevel} (default: @code{"Info"})
21539 The level of logging desired. Accepted values are Debug, Info, Warning
21544 @node Telephony Services
21545 @subsection Telephony Services
21547 @cindex Murmur (VoIP server)
21548 @cindex VoIP server
21549 This section describes how to set up and run a Murmur server. Murmur is
21550 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
21553 @deftp {Data Type} murmur-configuration
21554 The service type for the Murmur server. An example configuration can
21558 (service murmur-service-type
21559 (murmur-configuration
21561 "Welcome to this Mumble server running on Guix!")
21562 (cert-required? #t) ;disallow text password logins
21563 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
21564 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
21567 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
21568 password with the command that is printed during the activation phase.
21570 It is recommended to register a normal Mumble user account
21571 and grant it admin or moderator rights.
21572 You can use the @code{mumble} client to
21573 login as new normal user, register yourself, and log out.
21574 For the next step login with the name @code{SuperUser} use
21575 the @code{SuperUser} password that you set previously,
21576 and grant your newly registered mumble user administrator or moderator
21577 rights and create some channels.
21579 Available @code{murmur-configuration} fields are:
21582 @item @code{package} (default: @code{mumble})
21583 Package that contains @code{bin/murmurd}.
21585 @item @code{user} (default: @code{"murmur"})
21586 User who will run the Murmur server.
21588 @item @code{group} (default: @code{"murmur"})
21589 Group of the user who will run the murmur server.
21591 @item @code{port} (default: @code{64738})
21592 Port on which the server will listen.
21594 @item @code{welcome-text} (default: @code{""})
21595 Welcome text sent to clients when they connect.
21597 @item @code{server-password} (default: @code{""})
21598 Password the clients have to enter in order to connect.
21600 @item @code{max-users} (default: @code{100})
21601 Maximum of users that can be connected to the server at once.
21603 @item @code{max-user-bandwidth} (default: @code{#f})
21604 Maximum voice traffic a user can send per second.
21606 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
21607 File name of the sqlite database.
21608 The service's user will become the owner of the directory.
21610 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
21611 File name of the log file.
21612 The service's user will become the owner of the directory.
21614 @item @code{autoban-attempts} (default: @code{10})
21615 Maximum number of logins a user can make in @code{autoban-timeframe}
21616 without getting auto banned for @code{autoban-time}.
21618 @item @code{autoban-timeframe} (default: @code{120})
21619 Timeframe for autoban in seconds.
21621 @item @code{autoban-time} (default: @code{300})
21622 Amount of time in seconds for which a client gets banned
21623 when violating the autoban limits.
21625 @item @code{opus-threshold} (default: @code{100})
21626 Percentage of clients that need to support opus
21627 before switching over to opus audio codec.
21629 @item @code{channel-nesting-limit} (default: @code{10})
21630 How deep channels can be nested at maximum.
21632 @item @code{channelname-regex} (default: @code{#f})
21633 A string in form of a Qt regular expression that channel names must conform to.
21635 @item @code{username-regex} (default: @code{#f})
21636 A string in form of a Qt regular expression that user names must conform to.
21638 @item @code{text-message-length} (default: @code{5000})
21639 Maximum size in bytes that a user can send in one text chat message.
21641 @item @code{image-message-length} (default: @code{(* 128 1024)})
21642 Maximum size in bytes that a user can send in one image message.
21644 @item @code{cert-required?} (default: @code{#f})
21645 If it is set to @code{#t} clients that use weak password authentication
21646 will not be accepted. Users must have completed the certificate wizard to join.
21648 @item @code{remember-channel?} (default: @code{#f})
21649 Should murmur remember the last channel each user was in when they disconnected
21650 and put them into the remembered channel when they rejoin.
21652 @item @code{allow-html?} (default: @code{#f})
21653 Should html be allowed in text messages, user comments, and channel descriptions.
21655 @item @code{allow-ping?} (default: @code{#f})
21656 Setting to true exposes the current user count, the maximum user count, and
21657 the server's maximum bandwidth per client to unauthenticated users. In the
21658 Mumble client, this information is shown in the Connect dialog.
21660 Disabling this setting will prevent public listing of the server.
21662 @item @code{bonjour?} (default: @code{#f})
21663 Should the server advertise itself in the local network through the bonjour protocol.
21665 @item @code{send-version?} (default: @code{#f})
21666 Should the murmur server version be exposed in ping requests.
21668 @item @code{log-days} (default: @code{31})
21669 Murmur also stores logs in the database, which are accessible via RPC.
21670 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
21671 or -1 to disable logging to the database.
21673 @item @code{obfuscate-ips?} (default: @code{#t})
21674 Should logged ips be obfuscated to protect the privacy of users.
21676 @item @code{ssl-cert} (default: @code{#f})
21677 File name of the SSL/TLS certificate used for encrypted connections.
21680 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
21682 @item @code{ssl-key} (default: @code{#f})
21683 Filepath to the ssl private key used for encrypted connections.
21685 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
21688 @item @code{ssl-dh-params} (default: @code{#f})
21689 File name of a PEM-encoded file with Diffie-Hellman parameters
21690 for the SSL/TLS encryption. Alternatively you set it to
21691 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
21692 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
21694 @item @code{ssl-ciphers} (default: @code{#f})
21695 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
21698 This option is specified using
21699 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
21700 OpenSSL cipher list notation}.
21702 It is recommended that you try your cipher string using 'openssl ciphers <string>'
21703 before setting it here, to get a feel for which cipher suites you will get.
21704 After setting this option, it is recommend that you inspect your Murmur log
21705 to ensure that Murmur is using the cipher suites that you expected it to.
21707 Note: Changing this option may impact the backwards compatibility of your
21708 Murmur server, and can remove the ability for older Mumble clients to be able
21711 @item @code{public-registration} (default: @code{#f})
21712 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
21714 You can optionally register your server in the public server list that the
21715 @code{mumble} client shows on startup.
21716 You cannot register your server if you have set a @code{server-password},
21717 or set @code{allow-ping} to @code{#f}.
21719 It might take a few hours until it shows up in the public list.
21721 @item @code{file} (default: @code{#f})
21722 Optional alternative override for this configuration.
21726 @deftp {Data Type} murmur-public-registration-configuration
21727 Configuration for public registration of a murmur service.
21731 This is a display name for your server. Not to be confused with the hostname.
21733 @item @code{password}
21734 A password to identify your registration.
21735 Subsequent updates will need the same password. Don't lose your password.
21738 This should be a @code{http://} or @code{https://} link to your web
21741 @item @code{hostname} (default: @code{#f})
21742 By default your server will be listed by its IP address.
21743 If it is set your server will be linked by this host name instead.
21749 @node Monitoring Services
21750 @subsection Monitoring Services
21752 @subsubheading Tailon Service
21754 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
21755 viewing and searching log files.
21757 The following example will configure the service with default values.
21758 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
21761 (service tailon-service-type)
21764 The following example customises more of the Tailon configuration,
21765 adding @command{sed} to the list of allowed commands.
21768 (service tailon-service-type
21769 (tailon-configuration
21771 (tailon-configuration-file
21772 (allowed-commands '("tail" "grep" "awk" "sed"))))))
21776 @deftp {Data Type} tailon-configuration
21777 Data type representing the configuration of Tailon.
21778 This type has the following parameters:
21781 @item @code{config-file} (default: @code{(tailon-configuration-file)})
21782 The configuration file to use for Tailon. This can be set to a
21783 @dfn{tailon-configuration-file} record value, or any gexp
21784 (@pxref{G-Expressions}).
21786 For example, to instead use a local file, the @code{local-file} function
21790 (service tailon-service-type
21791 (tailon-configuration
21792 (config-file (local-file "./my-tailon.conf"))))
21795 @item @code{package} (default: @code{tailon})
21796 The tailon package to use.
21801 @deftp {Data Type} tailon-configuration-file
21802 Data type representing the configuration options for Tailon.
21803 This type has the following parameters:
21806 @item @code{files} (default: @code{(list "/var/log")})
21807 List of files to display. The list can include strings for a single file
21808 or directory, or a list, where the first item is the name of a
21809 subsection, and the remaining items are the files or directories in that
21812 @item @code{bind} (default: @code{"localhost:8080"})
21813 Address and port to which Tailon should bind on.
21815 @item @code{relative-root} (default: @code{#f})
21816 URL path to use for Tailon, set to @code{#f} to not use a path.
21818 @item @code{allow-transfers?} (default: @code{#t})
21819 Allow downloading the log files in the web interface.
21821 @item @code{follow-names?} (default: @code{#t})
21822 Allow tailing of not-yet existent files.
21824 @item @code{tail-lines} (default: @code{200})
21825 Number of lines to read initially from each file.
21827 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
21828 Commands to allow running. By default, @code{sed} is disabled.
21830 @item @code{debug?} (default: @code{#f})
21831 Set @code{debug?} to @code{#t} to show debug messages.
21833 @item @code{wrap-lines} (default: @code{#t})
21834 Initial line wrapping state in the web interface. Set to @code{#t} to
21835 initially wrap lines (the default), or to @code{#f} to initially not
21838 @item @code{http-auth} (default: @code{#f})
21839 HTTP authentication type to use. Set to @code{#f} to disable
21840 authentication (the default). Supported values are @code{"digest"} or
21843 @item @code{users} (default: @code{#f})
21844 If HTTP authentication is enabled (see @code{http-auth}), access will be
21845 restricted to the credentials provided here. To configure users, use a
21846 list of pairs, where the first element of the pair is the username, and
21847 the 2nd element of the pair is the password.
21850 (tailon-configuration-file
21851 (http-auth "basic")
21852 (users '(("user1" . "password1")
21853 ("user2" . "password2"))))
21860 @subsubheading Darkstat Service
21862 Darkstat is a packet sniffer that captures network traffic, calculates
21863 statistics about usage, and serves reports over HTTP.
21865 @defvar {Scheme Variable} darkstat-service-type
21866 This is the service type for the
21867 @uref{https://unix4lyfe.org/darkstat/, darkstat}
21868 service, its value must be a @code{darkstat-configuration} record as in
21872 (service darkstat-service-type
21873 (darkstat-configuration
21874 (interface "eno1")))
21878 @deftp {Data Type} darkstat-configuration
21879 Data type representing the configuration of @command{darkstat}.
21882 @item @code{package} (default: @code{darkstat})
21883 The darkstat package to use.
21885 @item @code{interface}
21886 Capture traffic on the specified network interface.
21888 @item @code{port} (default: @code{"667"})
21889 Bind the web interface to the specified port.
21891 @item @code{bind-address} (default: @code{"127.0.0.1"})
21892 Bind the web interface to the specified address.
21894 @item @code{base} (default: @code{"/"})
21895 Specify the path of the base URL. This can be useful if
21896 @command{darkstat} is accessed via a reverse proxy.
21901 @subsubheading Prometheus Node Exporter Service
21903 @cindex prometheus-node-exporter
21904 The Prometheus ``node exporter'' makes hardware and operating system statistics
21905 provided by the Linux kernel available for the Prometheus monitoring system.
21906 This service should be deployed on all physical nodes and virtual machines,
21907 where monitoring these statistics is desirable.
21909 @defvar {Scheme variable} prometheus-node-exporter-service-type
21910 This is the service type for the
21911 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
21912 service, its value must be a @code{prometheus-node-exporter-configuration}
21913 record as in this example:
21916 (service prometheus-node-exporter-service-type
21917 (prometheus-node-exporter-configuration
21918 (web-listen-address ":9100")))
21922 @deftp {Data Type} prometheus-node-exporter-configuration
21923 Data type representing the configuration of @command{node_exporter}.
21926 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
21927 The prometheus-node-exporter package to use.
21929 @item @code{web-listen-address} (default: @code{":9100"})
21930 Bind the web interface to the specified address.
21935 @subsubheading Zabbix server
21936 @cindex zabbix zabbix-server
21937 Zabbix provides monitoring metrics, among others network utilization, CPU load
21938 and disk space consumption:
21941 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
21942 @item Auto-discovery of servers and network devices and interfaces.
21943 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
21944 @item Distributed monitoring with centralized web administration.
21945 @item Native high performance agents.
21946 @item SLA, and ITIL KPI metrics on reporting.
21947 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
21948 @item Remote command execution through Zabbix proxies.
21951 @c %start of fragment
21953 Available @code{zabbix-server-configuration} fields are:
21955 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
21956 The zabbix-server package.
21960 @deftypevr {@code{zabbix-server-configuration} parameter} string user
21961 User who will run the Zabbix server.
21963 Defaults to @samp{"zabbix"}.
21967 @deftypevr {@code{zabbix-server-configuration} parameter} group group
21968 Group who will run the Zabbix server.
21970 Defaults to @samp{"zabbix"}.
21974 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
21975 Database host name.
21977 Defaults to @samp{"127.0.0.1"}.
21981 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
21984 Defaults to @samp{"zabbix"}.
21988 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
21991 Defaults to @samp{"zabbix"}.
21995 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
21996 Database password. Please, use @code{include-files} with
21997 @code{DBPassword=SECRET} inside a specified file instead.
21999 Defaults to @samp{""}.
22003 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
22006 Defaults to @samp{5432}.
22010 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
22011 Specifies where log messages are written to:
22015 @code{system} - syslog.
22018 @code{file} - file specified with @code{log-file} parameter.
22021 @code{console} - standard output.
22025 Defaults to @samp{""}.
22029 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
22030 Log file name for @code{log-type} @code{file} parameter.
22032 Defaults to @samp{"/var/log/zabbix/server.log"}.
22036 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
22039 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
22043 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
22044 The location of certificate authority (CA) files for SSL server
22045 certificate verification.
22047 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
22051 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
22052 Location of SSL client certificates.
22054 Defaults to @samp{"/etc/ssl/certs"}.
22058 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
22059 Extra options will be appended to Zabbix server configuration file.
22061 Defaults to @samp{""}.
22065 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
22066 You may include individual files or all files in a directory in the
22067 configuration file.
22069 Defaults to @samp{()}.
22073 @c %end of fragment
22075 @subsubheading Zabbix agent
22076 @cindex zabbix zabbix-agent
22078 Zabbix agent gathers information for Zabbix server.
22080 @c %start of fragment
22082 Available @code{zabbix-agent-configuration} fields are:
22084 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
22085 The zabbix-agent package.
22089 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
22090 User who will run the Zabbix agent.
22092 Defaults to @samp{"zabbix"}.
22096 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
22097 Group who will run the Zabbix agent.
22099 Defaults to @samp{"zabbix"}.
22103 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
22104 Unique, case sensitive hostname which is required for active checks and
22105 must match hostname as configured on the server.
22107 Defaults to @samp{"Zabbix server"}.
22111 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
22112 Specifies where log messages are written to:
22116 @code{system} - syslog.
22119 @code{file} - file specified with @code{log-file} parameter.
22122 @code{console} - standard output.
22126 Defaults to @samp{""}.
22130 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
22131 Log file name for @code{log-type} @code{file} parameter.
22133 Defaults to @samp{"/var/log/zabbix/agent.log"}.
22137 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
22140 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
22144 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
22145 List of IP addresses, optionally in CIDR notation, or hostnames of
22146 Zabbix servers and Zabbix proxies. Incoming connections will be
22147 accepted only from the hosts listed here.
22149 Defaults to @samp{("127.0.0.1")}.
22153 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
22154 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
22155 proxies for active checks. If port is not specified, default port is
22156 used. If this parameter is not specified, active checks are disabled.
22158 Defaults to @samp{("127.0.0.1")}.
22162 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
22163 Extra options will be appended to Zabbix server configuration file.
22165 Defaults to @samp{""}.
22169 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
22170 You may include individual files or all files in a directory in the
22171 configuration file.
22173 Defaults to @samp{()}.
22177 @c %end of fragment
22179 @subsubheading Zabbix front-end
22180 @cindex zabbix zabbix-front-end
22182 This service provides a WEB interface to Zabbix server.
22184 @c %start of fragment
22186 Available @code{zabbix-front-end-configuration} fields are:
22188 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
22189 NGINX configuration.
22193 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
22194 Database host name.
22196 Defaults to @samp{"localhost"}.
22200 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
22203 Defaults to @samp{5432}.
22207 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
22210 Defaults to @samp{"zabbix"}.
22214 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
22217 Defaults to @samp{"zabbix"}.
22221 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
22222 Database password. Please, use @code{db-secret-file} instead.
22224 Defaults to @samp{""}.
22228 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
22229 Secret file containing the credentials for the Zabbix front-end. The value
22230 must be a local file name, not a G-expression. You are expected to create
22231 this file manually. Its contents will be copied into @file{zabbix.conf.php}
22232 as the value of @code{$DB['PASSWORD']}.
22234 Defaults to @samp{""}.
22238 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
22239 Zabbix server hostname.
22241 Defaults to @samp{"localhost"}.
22245 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
22246 Zabbix server port.
22248 Defaults to @samp{10051}.
22253 @c %end of fragment
22255 @node Kerberos Services
22256 @subsection Kerberos Services
22259 The @code{(gnu services kerberos)} module provides services relating to
22260 the authentication protocol @dfn{Kerberos}.
22262 @subsubheading Krb5 Service
22264 Programs using a Kerberos client library normally
22265 expect a configuration file in @file{/etc/krb5.conf}.
22266 This service generates such a file from a definition provided in the
22267 operating system declaration.
22268 It does not cause any daemon to be started.
22270 No ``keytab'' files are provided by this service---you must explicitly create them.
22271 This service is known to work with the MIT client library, @code{mit-krb5}.
22272 Other implementations have not been tested.
22274 @defvr {Scheme Variable} krb5-service-type
22275 A service type for Kerberos 5 clients.
22279 Here is an example of its use:
22281 (service krb5-service-type
22282 (krb5-configuration
22283 (default-realm "EXAMPLE.COM")
22284 (allow-weak-crypto? #t)
22287 (name "EXAMPLE.COM")
22288 (admin-server "groucho.example.com")
22289 (kdc "karl.example.com"))
22292 (admin-server "kerb-admin.argrx.edu")
22293 (kdc "keys.argrx.edu"))))))
22297 This example provides a Kerberos@tie{}5 client configuration which:
22299 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
22300 of which have distinct administration servers and key distribution centers;
22301 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
22302 specified by clients;
22303 @item Accepts services which only support encryption types known to be weak.
22306 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
22307 Only the most commonly used ones are described here.
22308 For a full list, and more detailed explanation of each, see the MIT
22309 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
22313 @deftp {Data Type} krb5-realm
22314 @cindex realm, kerberos
22317 This field is a string identifying the name of the realm.
22318 A common convention is to use the fully qualified DNS name of your organization,
22319 converted to upper case.
22321 @item @code{admin-server}
22322 This field is a string identifying the host where the administration server is
22326 This field is a string identifying the key distribution center
22331 @deftp {Data Type} krb5-configuration
22334 @item @code{allow-weak-crypto?} (default: @code{#f})
22335 If this flag is @code{#t} then services which only offer encryption algorithms
22336 known to be weak will be accepted.
22338 @item @code{default-realm} (default: @code{#f})
22339 This field should be a string identifying the default Kerberos
22340 realm for the client.
22341 You should set this field to the name of your Kerberos realm.
22342 If this value is @code{#f}
22343 then a realm must be specified with every Kerberos principal when invoking programs
22344 such as @command{kinit}.
22346 @item @code{realms}
22347 This should be a non-empty list of @code{krb5-realm} objects, which clients may
22349 Normally, one of them will have a @code{name} field matching the @code{default-realm}
22355 @subsubheading PAM krb5 Service
22358 The @code{pam-krb5} service allows for login authentication and password
22359 management via Kerberos.
22360 You will need this service if you want PAM enabled applications to authenticate
22361 users using Kerberos.
22363 @defvr {Scheme Variable} pam-krb5-service-type
22364 A service type for the Kerberos 5 PAM module.
22367 @deftp {Data Type} pam-krb5-configuration
22368 Data type representing the configuration of the Kerberos 5 PAM module.
22369 This type has the following parameters:
22371 @item @code{pam-krb5} (default: @code{pam-krb5})
22372 The pam-krb5 package to use.
22374 @item @code{minimum-uid} (default: @code{1000})
22375 The smallest user ID for which Kerberos authentications should be attempted.
22376 Local accounts with lower values will silently fail to authenticate.
22381 @node LDAP Services
22382 @subsection LDAP Services
22384 @cindex nslcd, LDAP service
22386 The @code{(gnu services authentication)} module provides the
22387 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
22388 server. In addition to configuring the service itself, you may want to add
22389 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
22390 Switch} for detailed information.
22392 Here is a simple operating system declaration with a default configuration of
22393 the @code{nslcd-service-type} and a Name Service Switch configuration that
22394 consults the @code{ldap} name service last:
22397 (use-service-modules authentication)
22398 (use-modules (gnu system nss))
22404 (service nslcd-service-type)
22405 (service dhcp-client-service-type)
22407 (name-service-switch
22408 (let ((services (list (name-service (name "db"))
22409 (name-service (name "files"))
22410 (name-service (name "ldap")))))
22411 (name-service-switch
22412 (inherit %mdns-host-lookup-nss)
22413 (password services)
22416 (netgroup services)
22417 (gshadow services)))))
22420 @c %start of generated documentation for nslcd-configuration
22422 Available @code{nslcd-configuration} fields are:
22424 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
22425 The @code{nss-pam-ldapd} package to use.
22429 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
22430 The number of threads to start that can handle requests and perform LDAP
22431 queries. Each thread opens a separate connection to the LDAP server.
22432 The default is to start 5 threads.
22434 Defaults to @samp{disabled}.
22438 @deftypevr {@code{nslcd-configuration} parameter} string uid
22439 This specifies the user id with which the daemon should be run.
22441 Defaults to @samp{"nslcd"}.
22445 @deftypevr {@code{nslcd-configuration} parameter} string gid
22446 This specifies the group id with which the daemon should be run.
22448 Defaults to @samp{"nslcd"}.
22452 @deftypevr {@code{nslcd-configuration} parameter} log-option log
22453 This option controls the way logging is done via a list containing
22454 SCHEME and LEVEL. The SCHEME argument may either be the symbols
22455 @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
22456 argument is optional and specifies the log level. The log level may be
22457 one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
22458 @samp{notice}, @samp{info} or @samp{debug}. All messages with the
22459 specified log level or higher are logged.
22461 Defaults to @samp{("/var/log/nslcd" info)}.
22465 @deftypevr {@code{nslcd-configuration} parameter} list uri
22466 The list of LDAP server URIs. Normally, only the first server will be
22467 used with the following servers as fall-back.
22469 Defaults to @samp{("ldap://localhost:389/")}.
22473 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
22474 The version of the LDAP protocol to use. The default is to use the
22475 maximum version supported by the LDAP library.
22477 Defaults to @samp{disabled}.
22481 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
22482 Specifies the distinguished name with which to bind to the directory
22483 server for lookups. The default is to bind anonymously.
22485 Defaults to @samp{disabled}.
22489 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
22490 Specifies the credentials with which to bind. This option is only
22491 applicable when used with binddn.
22493 Defaults to @samp{disabled}.
22497 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
22498 Specifies the distinguished name to use when the root user tries to
22499 modify a user's password using the PAM module.
22501 Defaults to @samp{disabled}.
22505 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
22506 Specifies the credentials with which to bind if the root user tries to
22507 change a user's password. This option is only applicable when used with
22510 Defaults to @samp{disabled}.
22514 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
22515 Specifies the SASL mechanism to be used when performing SASL
22518 Defaults to @samp{disabled}.
22522 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
22523 Specifies the SASL realm to be used when performing SASL authentication.
22525 Defaults to @samp{disabled}.
22529 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
22530 Specifies the authentication identity to be used when performing SASL
22533 Defaults to @samp{disabled}.
22537 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
22538 Specifies the authorization identity to be used when performing SASL
22541 Defaults to @samp{disabled}.
22545 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
22546 Determines whether the LDAP server host name should be canonicalised. If
22547 this is enabled the LDAP library will do a reverse host name lookup. By
22548 default, it is left up to the LDAP library whether this check is
22551 Defaults to @samp{disabled}.
22555 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
22556 Set the name for the GSS-API Kerberos credentials cache.
22558 Defaults to @samp{disabled}.
22562 @deftypevr {@code{nslcd-configuration} parameter} string base
22563 The directory search base.
22565 Defaults to @samp{"dc=example,dc=com"}.
22569 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
22570 Specifies the search scope (subtree, onelevel, base or children). The
22571 default scope is subtree; base scope is almost never useful for name
22572 service lookups; children scope is not supported on all servers.
22574 Defaults to @samp{(subtree)}.
22578 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
22579 Specifies the policy for dereferencing aliases. The default policy is
22580 to never dereference aliases.
22582 Defaults to @samp{disabled}.
22586 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
22587 Specifies whether automatic referral chasing should be enabled. The
22588 default behaviour is to chase referrals.
22590 Defaults to @samp{disabled}.
22594 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
22595 This option allows for custom attributes to be looked up instead of the
22596 default RFC 2307 attributes. It is a list of maps, each consisting of
22597 the name of a map, the RFC 2307 attribute to match and the query
22598 expression for the attribute as it is available in the directory.
22600 Defaults to @samp{()}.
22604 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
22605 A list of filters consisting of the name of a map to which the filter
22606 applies and an LDAP search filter expression.
22608 Defaults to @samp{()}.
22612 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
22613 Specifies the time limit in seconds to use when connecting to the
22614 directory server. The default value is 10 seconds.
22616 Defaults to @samp{disabled}.
22620 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
22621 Specifies the time limit (in seconds) to wait for a response from the
22622 LDAP server. A value of zero, which is the default, is to wait
22623 indefinitely for searches to be completed.
22625 Defaults to @samp{disabled}.
22629 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
22630 Specifies the period if inactivity (in seconds) after which the con‐
22631 nection to the LDAP server will be closed. The default is not to time
22634 Defaults to @samp{disabled}.
22638 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
22639 Specifies the number of seconds to sleep when connecting to all LDAP
22640 servers fails. By default one second is waited between the first
22641 failure and the first retry.
22643 Defaults to @samp{disabled}.
22647 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
22648 Specifies the time after which the LDAP server is considered to be
22649 permanently unavailable. Once this time is reached retries will be done
22650 only once per this time period. The default value is 10 seconds.
22652 Defaults to @samp{disabled}.
22656 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
22657 Specifies whether to use SSL/TLS or not (the default is not to). If
22658 'start-tls is specified then StartTLS is used rather than raw LDAP over
22661 Defaults to @samp{disabled}.
22665 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
22666 Specifies what checks to perform on a server-supplied certificate. The
22667 meaning of the values is described in the ldap.conf(5) manual page.
22669 Defaults to @samp{disabled}.
22673 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
22674 Specifies the directory containing X.509 certificates for peer authen‐
22675 tication. This parameter is ignored when using GnuTLS.
22677 Defaults to @samp{disabled}.
22681 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
22682 Specifies the path to the X.509 certificate for peer authentication.
22684 Defaults to @samp{disabled}.
22688 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
22689 Specifies the path to an entropy source. This parameter is ignored when
22692 Defaults to @samp{disabled}.
22696 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
22697 Specifies the ciphers to use for TLS as a string.
22699 Defaults to @samp{disabled}.
22703 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
22704 Specifies the path to the file containing the local certificate for
22705 client TLS authentication.
22707 Defaults to @samp{disabled}.
22711 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
22712 Specifies the path to the file containing the private key for client TLS
22715 Defaults to @samp{disabled}.
22719 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
22720 Set this to a number greater than 0 to request paged results from the
22721 LDAP server in accordance with RFC2696. The default (0) is to not
22722 request paged results.
22724 Defaults to @samp{disabled}.
22728 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
22729 This option prevents group membership lookups through LDAP for the
22730 specified users. Alternatively, the value 'all-local may be used. With
22731 that value nslcd builds a full list of non-LDAP users on startup.
22733 Defaults to @samp{disabled}.
22737 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
22738 This option ensures that LDAP users with a numeric user id lower than
22739 the specified value are ignored.
22741 Defaults to @samp{disabled}.
22745 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
22746 This option specifies an offset that is added to all LDAP numeric user
22747 ids. This can be used to avoid user id collisions with local users.
22749 Defaults to @samp{disabled}.
22753 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
22754 This option specifies an offset that is added to all LDAP numeric group
22755 ids. This can be used to avoid user id collisions with local groups.
22757 Defaults to @samp{disabled}.
22761 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
22762 If this option is set, the member attribute of a group may point to
22763 another group. Members of nested groups are also returned in the higher
22764 level group and parent groups are returned when finding groups for a
22765 specific user. The default is not to perform extra searches for nested
22768 Defaults to @samp{disabled}.
22772 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
22773 If this option is set, the group member list is not retrieved when
22774 looking up groups. Lookups for finding which groups a user belongs to
22775 will remain functional so the user will likely still get the correct
22776 groups assigned on login.
22778 Defaults to @samp{disabled}.
22782 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
22783 If this option is set, functions which cause all user/group entries to
22784 be loaded from the directory will not succeed in doing so. This can
22785 dramatically reduce LDAP server load in situations where there are a
22786 great number of users and/or groups. This option is not recommended for
22787 most configurations.
22789 Defaults to @samp{disabled}.
22793 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
22794 This option can be used to specify how user and group names are verified
22795 within the system. This pattern is used to check all user and group
22796 names that are requested and returned from LDAP.
22798 Defaults to @samp{disabled}.
22802 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
22803 This specifies whether or not to perform searches using case-insensitive
22804 matching. Enabling this could open up the system to authorization
22805 bypass vulnerabilities and introduce nscd cache poisoning
22806 vulnerabilities which allow denial of service.
22808 Defaults to @samp{disabled}.
22812 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
22813 This option specifies whether password policy controls are requested and
22814 handled from the LDAP server when performing user authentication.
22816 Defaults to @samp{disabled}.
22820 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
22821 By default nslcd performs an LDAP search with the user's credentials
22822 after BIND (authentication) to ensure that the BIND operation was
22823 successful. The default search is a simple check to see if the user's
22824 DN exists. A search filter can be specified that will be used instead.
22825 It should return at least one entry.
22827 Defaults to @samp{disabled}.
22831 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
22832 This option allows flexible fine tuning of the authorisation check that
22833 should be performed. The search filter specified is executed and if any
22834 entries match, access is granted, otherwise access is denied.
22836 Defaults to @samp{disabled}.
22840 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
22841 If this option is set password modification using pam_ldap will be
22842 denied and the specified message will be presented to the user instead.
22843 The message can be used to direct the user to an alternative means of
22844 changing their password.
22846 Defaults to @samp{disabled}.
22850 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
22851 List of pam service names for which LDAP authentication should suffice.
22853 Defaults to @samp{()}.
22857 @c %end of generated documentation for nslcd-configuration
22861 @subsection Web Services
22866 The @code{(gnu services web)} module provides the Apache HTTP Server,
22867 the nginx web server, and also a fastcgi wrapper daemon.
22869 @subsubheading Apache HTTP Server
22871 @deffn {Scheme Variable} httpd-service-type
22872 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
22873 (@dfn{httpd}). The value for this service type is a
22874 @code{httpd-configuration} record.
22876 A simple example configuration is given below.
22879 (service httpd-service-type
22880 (httpd-configuration
22883 (server-name "www.example.com")
22884 (document-root "/srv/http/www.example.com")))))
22887 Other services can also extend the @code{httpd-service-type} to add to
22891 (simple-service 'www.example.com-server httpd-service-type
22895 (list (string-join '("ServerName www.example.com"
22896 "DocumentRoot /srv/http/www.example.com")
22901 The details for the @code{httpd-configuration}, @code{httpd-module},
22902 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
22905 @deffn {Data Type} httpd-configuration
22906 This data type represents the configuration for the httpd service.
22909 @item @code{package} (default: @code{httpd})
22910 The httpd package to use.
22912 @item @code{pid-file} (default: @code{"/var/run/httpd"})
22913 The pid file used by the shepherd-service.
22915 @item @code{config} (default: @code{(httpd-config-file)})
22916 The configuration file to use with the httpd service. The default value
22917 is a @code{httpd-config-file} record, but this can also be a different
22918 G-expression that generates a file, for example a @code{plain-file}. A
22919 file outside of the store can also be specified through a string.
22924 @deffn {Data Type} httpd-module
22925 This data type represents a module for the httpd service.
22929 The name of the module.
22932 The file for the module. This can be relative to the httpd package being
22933 used, the absolute location of a file, or a G-expression for a file
22934 within the store, for example @code{(file-append mod-wsgi
22935 "/modules/mod_wsgi.so")}.
22940 @defvr {Scheme Variable} %default-httpd-modules
22941 A default list of @code{httpd-module} objects.
22944 @deffn {Data Type} httpd-config-file
22945 This data type represents a configuration file for the httpd service.
22948 @item @code{modules} (default: @code{%default-httpd-modules})
22949 The modules to load. Additional modules can be added here, or loaded by
22950 additional configuration.
22952 For example, in order to handle requests for PHP files, you can use Apache’s
22953 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
22956 (service httpd-service-type
22957 (httpd-configuration
22962 (name "proxy_module")
22963 (file "modules/mod_proxy.so"))
22965 (name "proxy_fcgi_module")
22966 (file "modules/mod_proxy_fcgi.so"))
22967 %default-httpd-modules))
22968 (extra-config (list "\
22969 <FilesMatch \\.php$>
22970 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
22971 </FilesMatch>"))))))
22972 (service php-fpm-service-type
22973 (php-fpm-configuration
22974 (socket "/var/run/php-fpm.sock")
22975 (socket-group "httpd")))
22978 @item @code{server-root} (default: @code{httpd})
22979 The @code{ServerRoot} in the configuration file, defaults to the httpd
22980 package. Directives including @code{Include} and @code{LoadModule} are
22981 taken as relative to the server root.
22983 @item @code{server-name} (default: @code{#f})
22984 The @code{ServerName} in the configuration file, used to specify the
22985 request scheme, hostname and port that the server uses to identify
22988 This doesn't need to be set in the server config, and can be specified
22989 in virtual hosts. The default is @code{#f} to not specify a
22992 @item @code{document-root} (default: @code{"/srv/http"})
22993 The @code{DocumentRoot} from which files will be served.
22995 @item @code{listen} (default: @code{'("80")})
22996 The list of values for the @code{Listen} directives in the config
22997 file. The value should be a list of strings, when each string can
22998 specify the port number to listen on, and optionally the IP address and
23001 @item @code{pid-file} (default: @code{"/var/run/httpd"})
23002 The @code{PidFile} to use. This should match the @code{pid-file} set in
23003 the @code{httpd-configuration} so that the Shepherd service is
23004 configured correctly.
23006 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
23007 The @code{ErrorLog} to which the server will log errors.
23009 @item @code{user} (default: @code{"httpd"})
23010 The @code{User} which the server will answer requests as.
23012 @item @code{group} (default: @code{"httpd"})
23013 The @code{Group} which the server will answer requests as.
23015 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
23016 A flat list of strings and G-expressions which will be added to the end
23017 of the configuration file.
23019 Any values which the service is extended with will be appended to this
23025 @deffn {Data Type} httpd-virtualhost
23026 This data type represents a virtualhost configuration block for the httpd service.
23028 These should be added to the extra-config for the httpd-service.
23031 (simple-service 'www.example.com-server httpd-service-type
23035 (list (string-join '("ServerName www.example.com"
23036 "DocumentRoot /srv/http/www.example.com")
23041 @item @code{addresses-and-ports}
23042 The addresses and ports for the @code{VirtualHost} directive.
23044 @item @code{contents}
23045 The contents of the @code{VirtualHost} directive, this should be a list
23046 of strings and G-expressions.
23051 @subsubheading NGINX
23053 @deffn {Scheme Variable} nginx-service-type
23054 Service type for the @uref{https://nginx.org/,NGinx} web server. The
23055 value for this service type is a @code{<nginx-configuration>} record.
23057 A simple example configuration is given below.
23060 (service nginx-service-type
23061 (nginx-configuration
23063 (list (nginx-server-configuration
23064 (server-name '("www.example.com"))
23065 (root "/srv/http/www.example.com"))))))
23068 In addition to adding server blocks to the service configuration
23069 directly, this service can be extended by other services to add server
23070 blocks, as in this example:
23073 (simple-service 'my-extra-server nginx-service-type
23074 (list (nginx-server-configuration
23075 (root "/srv/http/extra-website")
23076 (try-files (list "$uri" "$uri/index.html")))))
23080 At startup, @command{nginx} has not yet read its configuration file, so
23081 it uses a default file to log error messages. If it fails to load its
23082 configuration file, that is where error messages are logged. After the
23083 configuration file is loaded, the default error log file changes as per
23084 configuration. In our case, startup error messages can be found in
23085 @file{/var/run/nginx/logs/error.log}, and after configuration in
23086 @file{/var/log/nginx/error.log}. The second location can be changed
23087 with the @var{log-directory} configuration option.
23089 @deffn {Data Type} nginx-configuration
23090 This data type represents the configuration for NGinx. Some
23091 configuration can be done through this and the other provided record
23092 types, or alternatively, a config file can be provided.
23095 @item @code{nginx} (default: @code{nginx})
23096 The nginx package to use.
23098 @item @code{log-directory} (default: @code{"/var/log/nginx"})
23099 The directory to which NGinx will write log files.
23101 @item @code{run-directory} (default: @code{"/var/run/nginx"})
23102 The directory in which NGinx will create a pid file, and write temporary
23105 @item @code{server-blocks} (default: @code{'()})
23106 A list of @dfn{server blocks} to create in the generated configuration
23107 file, the elements should be of type
23108 @code{<nginx-server-configuration>}.
23110 The following example would setup NGinx to serve @code{www.example.com}
23111 from the @code{/srv/http/www.example.com} directory, without using
23114 (service nginx-service-type
23115 (nginx-configuration
23117 (list (nginx-server-configuration
23118 (server-name '("www.example.com"))
23119 (root "/srv/http/www.example.com"))))))
23122 @item @code{upstream-blocks} (default: @code{'()})
23123 A list of @dfn{upstream blocks} to create in the generated configuration
23124 file, the elements should be of type
23125 @code{<nginx-upstream-configuration>}.
23127 Configuring upstreams through the @code{upstream-blocks} can be useful
23128 when combined with @code{locations} in the
23129 @code{<nginx-server-configuration>} records. The following example
23130 creates a server configuration with one location configuration, that
23131 will proxy requests to a upstream configuration, which will handle
23132 requests with two servers.
23137 (nginx-configuration
23139 (list (nginx-server-configuration
23140 (server-name '("www.example.com"))
23141 (root "/srv/http/www.example.com")
23144 (nginx-location-configuration
23146 (body '("proxy_pass http://server-proxy;"))))))))
23148 (list (nginx-upstream-configuration
23149 (name "server-proxy")
23150 (servers (list "server1.example.com"
23151 "server2.example.com")))))))
23154 @item @code{file} (default: @code{#f})
23155 If a configuration @var{file} is provided, this will be used, rather than
23156 generating a configuration file from the provided @code{log-directory},
23157 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
23158 proper operation, these arguments should match what is in @var{file} to ensure
23159 that the directories are created when the service is activated.
23161 This can be useful if you have an existing configuration file, or it's
23162 not possible to do what is required through the other parts of the
23163 nginx-configuration record.
23165 @item @code{server-names-hash-bucket-size} (default: @code{#f})
23166 Bucket size for the server names hash tables, defaults to @code{#f} to
23167 use the size of the processors cache line.
23169 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
23170 Maximum bucket size for the server names hash tables.
23172 @item @code{modules} (default: @code{'()})
23173 List of nginx dynamic modules to load. This should be a list of file
23174 names of loadable modules, as in this example:
23179 (file-append nginx-accept-language-module "\
23180 /etc/nginx/modules/ngx_http_accept_language_module.so")
23181 (file-append nginx-lua-module "\
23182 /etc/nginx/modules/ngx_http_lua_module.so")))
23185 @item @code{lua-package-path} (default: @code{'()})
23186 List of nginx lua packages to load. This should be a list of package
23187 names of loadable lua modules, as in this example:
23190 (lua-package-path (list lua-resty-core
23197 @item @code{lua-package-cpath} (default: @code{'()})
23198 List of nginx lua C packages to load. This should be a list of package
23199 names of loadable lua C modules, as in this example:
23202 (lua-package-cpath (list lua-resty-signal))
23205 @item @code{global-directives} (default: @code{'((events . ()))})
23206 Association list of global directives for the top level of the nginx
23207 configuration. Values may themselves be association lists.
23211 `((worker_processes . 16)
23213 (events . ((worker_connections . 1024)))))
23216 @item @code{extra-content} (default: @code{""})
23217 Extra content for the @code{http} block. Should be string or a string
23218 valued G-expression.
23223 @deftp {Data Type} nginx-server-configuration
23224 Data type representing the configuration of an nginx server block.
23225 This type has the following parameters:
23228 @item @code{listen} (default: @code{'("80" "443 ssl")})
23229 Each @code{listen} directive sets the address and port for IP, or the
23230 path for a UNIX-domain socket on which the server will accept requests.
23231 Both address and port, or only address or only port can be specified.
23232 An address may also be a hostname, for example:
23235 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
23238 @item @code{server-name} (default: @code{(list 'default)})
23239 A list of server names this server represents. @code{'default} represents the
23240 default server for connections matching no other server.
23242 @item @code{root} (default: @code{"/srv/http"})
23243 Root of the website nginx will serve.
23245 @item @code{locations} (default: @code{'()})
23246 A list of @dfn{nginx-location-configuration} or
23247 @dfn{nginx-named-location-configuration} records to use within this
23250 @item @code{index} (default: @code{(list "index.html")})
23251 Index files to look for when clients ask for a directory. If it cannot be found,
23252 Nginx will send the list of files in the directory.
23254 @item @code{try-files} (default: @code{'()})
23255 A list of files whose existence is checked in the specified order.
23256 @code{nginx} will use the first file it finds to process the request.
23258 @item @code{ssl-certificate} (default: @code{#f})
23259 Where to find the certificate for secure connections. Set it to @code{#f} if
23260 you don't have a certificate or you don't want to use HTTPS.
23262 @item @code{ssl-certificate-key} (default: @code{#f})
23263 Where to find the private key for secure connections. Set it to @code{#f} if
23264 you don't have a key or you don't want to use HTTPS.
23266 @item @code{server-tokens?} (default: @code{#f})
23267 Whether the server should add its configuration to response.
23269 @item @code{raw-content} (default: @code{'()})
23270 A list of raw lines added to the server block.
23275 @deftp {Data Type} nginx-upstream-configuration
23276 Data type representing the configuration of an nginx @code{upstream}
23277 block. This type has the following parameters:
23281 Name for this group of servers.
23283 @item @code{servers}
23284 Specify the addresses of the servers in the group. The address can be
23285 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
23286 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
23287 prefix @samp{unix:}. For addresses using an IP address or domain name,
23288 the default port is 80, and a different port can be specified
23294 @deftp {Data Type} nginx-location-configuration
23295 Data type representing the configuration of an nginx @code{location}
23296 block. This type has the following parameters:
23300 URI which this location block matches.
23302 @anchor{nginx-location-configuration body}
23304 Body of the location block, specified as a list of strings. This can contain
23306 configuration directives. For example, to pass requests to a upstream
23307 server group defined using an @code{nginx-upstream-configuration} block,
23308 the following directive would be specified in the body @samp{(list "proxy_pass
23309 http://upstream-name;")}.
23314 @deftp {Data Type} nginx-named-location-configuration
23315 Data type representing the configuration of an nginx named location
23316 block. Named location blocks are used for request redirection, and not
23317 used for regular request processing. This type has the following
23322 Name to identify this location block.
23325 @xref{nginx-location-configuration body}, as the body for named location
23326 blocks can be used in a similar way to the
23327 @code{nginx-location-configuration body}. One restriction is that the
23328 body of a named location block cannot contain location blocks.
23333 @subsubheading Varnish Cache
23335 Varnish is a fast cache server that sits in between web applications
23336 and end users. It proxies requests from clients and caches the
23337 accessed URLs such that multiple requests for the same resource only
23338 creates one request to the back-end.
23340 @defvr {Scheme Variable} varnish-service-type
23341 Service type for the Varnish daemon.
23344 @deftp {Data Type} varnish-configuration
23345 Data type representing the @code{varnish} service configuration.
23346 This type has the following parameters:
23349 @item @code{package} (default: @code{varnish})
23350 The Varnish package to use.
23352 @item @code{name} (default: @code{"default"})
23353 A name for this Varnish instance. Varnish will create a directory in
23354 @file{/var/varnish/} with this name and keep temporary files there. If
23355 the name starts with a forward slash, it is interpreted as an absolute
23358 Pass the @code{-n} argument to other Varnish programs to connect to the
23359 named instance, e.g.@: @command{varnishncsa -n default}.
23361 @item @code{backend} (default: @code{"localhost:8080"})
23362 The backend to use. This option has no effect if @code{vcl} is set.
23364 @item @code{vcl} (default: #f)
23365 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
23366 is @code{#f}, Varnish will proxy @code{backend} using the default
23367 configuration. Otherwise this must be a file-like object with valid
23370 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
23371 For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
23372 can do something along these lines:
23375 (define %gnu-mirror
23376 (plain-file "gnu.vcl"
23378 backend gnu @{ .host = \"www.gnu.org\"; @}"))
23382 (services (cons (service varnish-service-type
23383 (varnish-configuration
23385 (vcl %gnu-mirror)))
23389 The configuration of an already running Varnish instance can be inspected
23390 and changed using the @command{varnishadm} program.
23392 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
23393 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
23394 comprehensive documentation on Varnish and its configuration language.
23396 @item @code{listen} (default: @code{'("localhost:80")})
23397 List of addresses Varnish will listen on.
23399 @item @code{storage} (default: @code{'("malloc,128m")})
23400 List of storage backends that will be available in VCL.
23402 @item @code{parameters} (default: @code{'()})
23403 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
23405 @item @code{extra-options} (default: @code{'()})
23406 Additional arguments to pass to the @command{varnishd} process.
23411 @subsubheading Patchwork
23413 Patchwork is a patch tracking system. It can collect patches sent to a
23414 mailing list, and display them in a web interface.
23416 @defvr {Scheme Variable} patchwork-service-type
23417 Service type for Patchwork.
23420 The following example is an example of a minimal service for Patchwork, for
23421 the @code{patchwork.example.com} domain.
23424 (service patchwork-service-type
23425 (patchwork-configuration
23426 (domain "patchwork.example.com")
23428 (patchwork-settings-module
23429 (allowed-hosts (list domain))
23430 (default-from-email "patchwork@@patchwork.example.com")))
23431 (getmail-retriever-config
23432 (getmail-retriever-configuration
23433 (type "SimpleIMAPSSLRetriever")
23434 (server "imap.example.com")
23436 (username "patchwork")
23438 (list (file-append coreutils "/bin/cat")
23439 "/etc/getmail-patchwork-imap-password"))
23441 '((mailboxes . ("Patches"))))))))
23445 There are three records for configuring the Patchwork service. The
23446 @code{<patchwork-configuration>} relates to the configuration for Patchwork
23447 within the HTTPD service.
23449 The @code{settings-module} field within the @code{<patchwork-configuration>}
23450 record can be populated with the @code{<patchwork-settings-module>} record,
23451 which describes a settings module that is generated within the Guix store.
23453 For the @code{database-configuration} field within the
23454 @code{<patchwork-settings-module>}, the
23455 @code{<patchwork-database-configuration>} must be used.
23457 @deftp {Data Type} patchwork-configuration
23458 Data type representing the Patchwork service configuration. This type has the
23459 following parameters:
23462 @item @code{patchwork} (default: @code{patchwork})
23463 The Patchwork package to use.
23465 @item @code{domain}
23466 The domain to use for Patchwork, this is used in the HTTPD service virtual
23469 @item @code{settings-module}
23470 The settings module to use for Patchwork. As a Django application, Patchwork
23471 is configured with a Python module containing the settings. This can either be
23472 an instance of the @code{<patchwork-settings-module>} record, any other record
23473 that represents the settings in the store, or a directory outside of the
23476 @item @code{static-path} (default: @code{"/static/"})
23477 The path under which the HTTPD service should serve the static files.
23479 @item @code{getmail-retriever-config}
23480 The getmail-retriever-configuration record value to use with
23481 Patchwork. Getmail will be configured with this value, the messages will be
23482 delivered to Patchwork.
23487 @deftp {Data Type} patchwork-settings-module
23488 Data type representing a settings module for Patchwork. Some of these
23489 settings relate directly to Patchwork, but others relate to Django, the web
23490 framework used by Patchwork, or the Django Rest Framework library. This type
23491 has the following parameters:
23494 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
23495 The database connection settings used for Patchwork. See the
23496 @code{<patchwork-database-configuration>} record type for more information.
23498 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
23499 Patchwork, as a Django web application uses a secret key for cryptographically
23500 signing values. This file should contain a unique unpredictable value.
23502 If this file does not exist, it will be created and populated with a random
23503 value by the patchwork-setup shepherd service.
23505 This setting relates to Django.
23507 @item @code{allowed-hosts}
23508 A list of valid hosts for this Patchwork service. This should at least include
23509 the domain specified in the @code{<patchwork-configuration>} record.
23511 This is a Django setting.
23513 @item @code{default-from-email}
23514 The email address from which Patchwork should send email by default.
23516 This is a Patchwork setting.
23518 @item @code{static-url} (default: @code{#f})
23519 The URL to use when serving static assets. It can be part of a URL, or a full
23520 URL, but must end in a @code{/}.
23522 If the default value is used, the @code{static-path} value from the
23523 @code{<patchwork-configuration>} record will be used.
23525 This is a Django setting.
23527 @item @code{admins} (default: @code{'()})
23528 Email addresses to send the details of errors that occur. Each value should
23529 be a list containing two elements, the name and then the email address.
23531 This is a Django setting.
23533 @item @code{debug?} (default: @code{#f})
23534 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
23535 messages will be shown.
23537 This is a Django setting.
23539 @item @code{enable-rest-api?} (default: @code{#t})
23540 Whether to enable the Patchwork REST API.
23542 This is a Patchwork setting.
23544 @item @code{enable-xmlrpc?} (default: @code{#t})
23545 Whether to enable the XML RPC API.
23547 This is a Patchwork setting.
23549 @item @code{force-https-links?} (default: @code{#t})
23550 Whether to use HTTPS links on Patchwork pages.
23552 This is a Patchwork setting.
23554 @item @code{extra-settings} (default: @code{""})
23555 Extra code to place at the end of the Patchwork settings module.
23560 @deftp {Data Type} patchwork-database-configuration
23561 Data type representing the database configuration for Patchwork.
23564 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
23565 The database engine to use.
23567 @item @code{name} (default: @code{"patchwork"})
23568 The name of the database to use.
23570 @item @code{user} (default: @code{"httpd"})
23571 The user to connect to the database as.
23573 @item @code{password} (default: @code{""})
23574 The password to use when connecting to the database.
23576 @item @code{host} (default: @code{""})
23577 The host to make the database connection to.
23579 @item @code{port} (default: @code{""})
23580 The port on which to connect to the database.
23585 @subsubheading Mumi
23587 @cindex Mumi, Debbugs Web interface
23588 @cindex Debbugs, Mumi Web interface
23589 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
23590 Web interface to the Debbugs bug tracker, by default for
23591 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
23592 but it also fetches and indexes mail retrieved from Debbugs.
23594 @defvr {Scheme Variable} mumi-service-type
23595 This is the service type for Mumi.
23598 @deftp {Data Type} mumi-configuration
23599 Data type representing the Mumi service configuration. This type has the
23603 @item @code{mumi} (default: @code{mumi})
23604 The Mumi package to use.
23606 @item @code{mailer?} (default: @code{#true})
23607 Whether to enable or disable the mailer component.
23609 @item @code{mumi-configuration-sender}
23610 The email address used as the sender for comments.
23612 @item @code{mumi-configuration-smtp}
23613 A URI to configure the SMTP settings for Mailutils. This could be
23614 something like @code{sendmail:///path/to/bin/msmtp} or any other URI
23615 supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
23616 mailutils, GNU@tie{}Mailutils}.
23622 @subsubheading FastCGI
23625 FastCGI is an interface between the front-end and the back-end of a web
23626 service. It is a somewhat legacy facility; new web services should
23627 generally just talk HTTP between the front-end and the back-end.
23628 However there are a number of back-end services such as PHP or the
23629 optimized HTTP Git repository access that use FastCGI, so we have
23630 support for it in Guix.
23632 To use FastCGI, you configure the front-end web server (e.g., nginx) to
23633 dispatch some subset of its requests to the fastcgi backend, which
23634 listens on a local TCP or UNIX socket. There is an intermediary
23635 @code{fcgiwrap} program that sits between the actual backend process and
23636 the web server. The front-end indicates which backend program to run,
23637 passing that information to the @code{fcgiwrap} process.
23639 @defvr {Scheme Variable} fcgiwrap-service-type
23640 A service type for the @code{fcgiwrap} FastCGI proxy.
23643 @deftp {Data Type} fcgiwrap-configuration
23644 Data type representing the configuration of the @code{fcgiwrap} service.
23645 This type has the following parameters:
23647 @item @code{package} (default: @code{fcgiwrap})
23648 The fcgiwrap package to use.
23650 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
23651 The socket on which the @code{fcgiwrap} process should listen, as a
23652 string. Valid @var{socket} values include
23653 @code{unix:@var{/path/to/unix/socket}},
23654 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
23655 @code{tcp6:[@var{ipv6_addr}]:port}.
23657 @item @code{user} (default: @code{fcgiwrap})
23658 @itemx @code{group} (default: @code{fcgiwrap})
23659 The user and group names, as strings, under which to run the
23660 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
23661 the user asks for the specific user or group names @code{fcgiwrap} that
23662 the corresponding user and/or group is present on the system.
23664 It is possible to configure a FastCGI-backed web service to pass HTTP
23665 authentication information from the front-end to the back-end, and to
23666 allow @code{fcgiwrap} to run the back-end process as a corresponding
23667 local user. To enable this capability on the back-end, run
23668 @code{fcgiwrap} as the @code{root} user and group. Note that this
23669 capability also has to be configured on the front-end as well.
23674 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
23675 with some additional features useful for sites of any size.
23677 These features include:
23679 @item Adaptive process spawning
23680 @item Basic statistics (similar to Apache's mod_status)
23681 @item Advanced process management with graceful stop/start
23682 @item Ability to start workers with different uid/gid/chroot/environment
23683 and different php.ini (replaces safe_mode)
23684 @item Stdout & stderr logging
23685 @item Emergency restart in case of accidental opcode cache destruction
23686 @item Accelerated upload support
23687 @item Support for a "slowlog"
23688 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
23689 a special function to finish request & flush all data while continuing to do
23690 something time-consuming (video converting, stats processing, etc.)
23692 ...@: and much more.
23694 @defvr {Scheme Variable} php-fpm-service-type
23695 A Service type for @code{php-fpm}.
23698 @deftp {Data Type} php-fpm-configuration
23699 Data Type for php-fpm service configuration.
23701 @item @code{php} (default: @code{php})
23702 The php package to use.
23703 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
23704 The address on which to accept FastCGI requests. Valid syntaxes are:
23706 @item @code{"ip.add.re.ss:port"}
23707 Listen on a TCP socket to a specific address on a specific port.
23708 @item @code{"port"}
23709 Listen on a TCP socket to all addresses on a specific port.
23710 @item @code{"/path/to/unix/socket"}
23711 Listen on a unix socket.
23714 @item @code{user} (default: @code{php-fpm})
23715 User who will own the php worker processes.
23716 @item @code{group} (default: @code{php-fpm})
23717 Group of the worker processes.
23718 @item @code{socket-user} (default: @code{php-fpm})
23719 User who can speak to the php-fpm socket.
23720 @item @code{socket-group} (default: @code{nginx})
23721 Group that can speak to the php-fpm socket.
23722 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
23723 The process id of the php-fpm process is written to this file
23724 once the service has started.
23725 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
23726 Log for the php-fpm master process.
23727 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
23728 Detailed settings for the php-fpm process manager.
23731 @item @code{<php-fpm-dynamic-process-manager-configuration>}
23732 @item @code{<php-fpm-static-process-manager-configuration>}
23733 @item @code{<php-fpm-on-demand-process-manager-configuration>}
23735 @item @code{display-errors} (default @code{#f})
23736 Determines whether php errors and warning should be sent to clients
23737 and displayed in their browsers.
23738 This is useful for local php development, but a security risk for public sites,
23739 as error messages can reveal passwords and personal data.
23740 @item @code{timezone} (default @code{#f})
23741 Specifies @code{php_admin_value[date.timezone]} parameter.
23742 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
23743 This file will log the @code{stderr} outputs of php worker processes.
23744 Can be set to @code{#f} to disable logging.
23745 @item @code{file} (default @code{#f})
23746 An optional override of the whole configuration.
23747 You can use the @code{mixed-text-file} function or an absolute filepath for it.
23748 @item @code{php-ini-file} (default @code{#f})
23749 An optional override of the default php settings.
23750 It may be any ``file-like'' object (@pxref{G-Expressions, file-like objects}).
23751 You can use the @code{mixed-text-file} function or an absolute filepath for it.
23753 For local development it is useful to set a higher timeout and memory
23754 limit for spawned php processes. This be accomplished with the
23755 following operating system configuration snippet:
23757 (define %local-php-ini
23758 (plain-file "php.ini"
23760 max_execution_time = 1800"))
23764 (services (cons (service php-fpm-service-type
23765 (php-fpm-configuration
23766 (php-ini-file %local-php-ini)))
23770 Consult the @url{https://www.php.net/manual/en/ini.core.php,core php.ini
23771 directives} for comprehensive documentation on the acceptable
23772 @file{php.ini} directives.
23776 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
23777 Data Type for the @code{dynamic} php-fpm process manager. With the
23778 @code{dynamic} process manager, spare worker processes are kept around
23779 based on it's configured limits.
23781 @item @code{max-children} (default: @code{5})
23782 Maximum of worker processes.
23783 @item @code{start-servers} (default: @code{2})
23784 How many worker processes should be started on start-up.
23785 @item @code{min-spare-servers} (default: @code{1})
23786 How many spare worker processes should be kept around at minimum.
23787 @item @code{max-spare-servers} (default: @code{3})
23788 How many spare worker processes should be kept around at maximum.
23792 @deftp {Data type} php-fpm-static-process-manager-configuration
23793 Data Type for the @code{static} php-fpm process manager. With the
23794 @code{static} process manager, an unchanging number of worker processes
23797 @item @code{max-children} (default: @code{5})
23798 Maximum of worker processes.
23802 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
23803 Data Type for the @code{on-demand} php-fpm process manager. With the
23804 @code{on-demand} process manager, worker processes are only created as
23807 @item @code{max-children} (default: @code{5})
23808 Maximum of worker processes.
23809 @item @code{process-idle-timeout} (default: @code{10})
23810 The time in seconds after which a process with no requests is killed.
23815 @deffn {Scheme Procedure} nginx-php-location @
23816 [#:nginx-package nginx] @
23817 [socket (string-append "/var/run/php" @
23818 (version-major (package-version php)) @
23820 A helper function to quickly add php to an @code{nginx-server-configuration}.
23823 A simple services setup for nginx with php can look like this:
23825 (services (cons* (service dhcp-client-service-type)
23826 (service php-fpm-service-type)
23827 (service nginx-service-type
23828 (nginx-server-configuration
23829 (server-name '("example.com"))
23830 (root "/srv/http/")
23832 (list (nginx-php-location)))
23834 (ssl-certificate #f)
23835 (ssl-certificate-key #f)))
23839 @cindex cat-avatar-generator
23840 The cat avatar generator is a simple service to demonstrate the use of php-fpm
23841 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
23842 the hash of a user's email address.
23844 @deffn {Scheme Procedure} cat-avatar-generator-service @
23845 [#:cache-dir "/var/cache/cat-avatar-generator"] @
23846 [#:package cat-avatar-generator] @
23847 [#:configuration (nginx-server-configuration)]
23848 Returns an nginx-server-configuration that inherits @code{configuration}. It
23849 extends the nginx configuration to add a server block that serves @code{package},
23850 a version of cat-avatar-generator. During execution, cat-avatar-generator will
23851 be able to use @code{cache-dir} as its cache directory.
23854 A simple setup for cat-avatar-generator can look like this:
23856 (services (cons* (cat-avatar-generator-service
23858 (nginx-server-configuration
23859 (server-name '("example.com"))))
23864 @subsubheading Hpcguix-web
23866 @cindex hpcguix-web
23867 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
23868 program is a customizable web interface to browse Guix packages,
23869 initially designed for users of high-performance computing (HPC)
23872 @defvr {Scheme Variable} hpcguix-web-service-type
23873 The service type for @code{hpcguix-web}.
23876 @deftp {Data Type} hpcguix-web-configuration
23877 Data type for the hpcguix-web service configuration.
23881 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
23882 configuration. The main items available in this spec are:
23885 @item @code{title-prefix} (default: @code{"hpcguix | "})
23886 The page title prefix.
23888 @item @code{guix-command} (default: @code{"guix"})
23889 The @command{guix} command.
23891 @item @code{package-filter-proc} (default: @code{(const #t)})
23892 A procedure specifying how to filter packages that are displayed.
23894 @item @code{package-page-extension-proc} (default: @code{(const '())})
23895 Extension package for @code{hpcguix-web}.
23897 @item @code{menu} (default: @code{'()})
23898 Additional entry in page @code{menu}.
23900 @item @code{channels} (default: @code{%default-channels})
23901 List of channels from which the package list is built (@pxref{Channels}).
23903 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
23904 The expiration time, in seconds, after which the package list is rebuilt from
23905 the latest instances of the given channels.
23908 See the hpcguix-web repository for a
23909 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
23912 @item @code{package} (default: @code{hpcguix-web})
23913 The hpcguix-web package to use.
23917 A typical hpcguix-web service declaration looks like this:
23920 (service hpcguix-web-service-type
23921 (hpcguix-web-configuration
23923 #~(define site-config
23924 (hpcweb-configuration
23925 (title-prefix "Guix-HPC - ")
23926 (menu '(("/about" "ABOUT"))))))))
23930 The hpcguix-web service periodically updates the package list it publishes by
23931 pulling channels from Git. To that end, it needs to access X.509 certificates
23932 so that it can authenticate Git servers when communicating over HTTPS, and it
23933 assumes that @file{/etc/ssl/certs} contains those certificates.
23935 Thus, make sure to add @code{nss-certs} or another certificate package to the
23936 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
23937 more information on X.509 certificates.
23940 @subsubheading gmnisrv
23943 The @uref{https://git.sr.ht/~sircmpwn/gmnisrv, gmnisrv} program is a
23944 simple @uref{https://gemini.circumlunar.space/, Gemini} protocol server.
23946 @deffn {Scheme Variable} gmnisrv-service-type
23947 This is the type of the gmnisrv service, whose value should be a
23948 @code{gmnisrv-configuration} object, as in this example:
23951 (service gmnisrv-service-type
23952 (gmnisrv-configuration
23953 (config-file (local-file "./my-gmnisrv.ini"))))
23957 @deftp {Data Type} gmnisrv-configuration
23958 Data type representing the configuration of gmnisrv.
23961 @item @code{package} (default: @var{gmnisrv})
23962 Package object of the gmnisrv server.
23964 @item @code{config-file} (default: @code{%default-gmnisrv-config-file})
23965 File-like object of the gmnisrv configuration file to use. The default
23966 configuration listens on port 1965 and serves files from
23967 @file{/srv/gemini}. Certificates are stored in
23968 @file{/var/lib/gemini/certs}. For more information, run @command{man
23969 gmnisrv} and @command{man gmnisrv.ini}.
23974 @node Certificate Services
23975 @subsection Certificate Services
23978 @cindex HTTP, HTTPS
23979 @cindex Let's Encrypt
23980 @cindex TLS certificates
23981 The @code{(gnu services certbot)} module provides a service to
23982 automatically obtain a valid TLS certificate from the Let's Encrypt
23983 certificate authority. These certificates can then be used to serve
23984 content securely over HTTPS or other TLS-based protocols, with the
23985 knowledge that the client will be able to verify the server's
23988 @url{https://letsencrypt.org/, Let's Encrypt} provides the
23989 @code{certbot} tool to automate the certification process. This tool
23990 first securely generates a key on the server. It then makes a request
23991 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
23992 checks that the request originates from the host in question by using a
23993 challenge-response protocol, requiring the server to provide its
23994 response over HTTP. If that protocol completes successfully, the CA
23995 signs the key, resulting in a certificate. That certificate is valid
23996 for a limited period of time, and therefore to continue to provide TLS
23997 services, the server needs to periodically ask the CA to renew its
24000 The certbot service automates this process: the initial key
24001 generation, the initial certification request to the Let's Encrypt
24002 service, the web server challenge/response integration, writing the
24003 certificate to disk, the automated periodic renewals, and the deployment
24004 tasks associated with the renewal (e.g.@: reloading services, copying keys
24005 with different permissions).
24007 Certbot is run twice a day, at a random minute within the hour. It
24008 won't do anything until your certificates are due for renewal or
24009 revoked, but running it regularly would give your service a chance of
24010 staying online in case a Let's Encrypt-initiated revocation happened for
24013 By using this service, you agree to the ACME Subscriber Agreement, which
24014 can be found there:
24015 @url{https://acme-v01.api.letsencrypt.org/directory}.
24017 @defvr {Scheme Variable} certbot-service-type
24018 A service type for the @code{certbot} Let's Encrypt client. Its value
24019 must be a @code{certbot-configuration} record as in this example:
24022 (define %nginx-deploy-hook
24024 "nginx-deploy-hook"
24025 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
24026 (kill pid SIGHUP))))
24028 (service certbot-service-type
24029 (certbot-configuration
24030 (email "foo@@example.net")
24033 (certificate-configuration
24034 (domains '("example.net" "www.example.net"))
24035 (deploy-hook %nginx-deploy-hook))
24036 (certificate-configuration
24037 (domains '("bar.example.net")))))))
24040 See below for details about @code{certbot-configuration}.
24043 @deftp {Data Type} certbot-configuration
24044 Data type representing the configuration of the @code{certbot} service.
24045 This type has the following parameters:
24048 @item @code{package} (default: @code{certbot})
24049 The certbot package to use.
24051 @item @code{webroot} (default: @code{/var/www})
24052 The directory from which to serve the Let's Encrypt challenge/response
24055 @item @code{certificates} (default: @code{()})
24056 A list of @code{certificates-configuration}s for which to generate
24057 certificates and request signatures. Each certificate has a @code{name}
24058 and several @code{domains}.
24060 @item @code{email} (default: @code{#f})
24061 Optional email address used for registration and recovery contact.
24062 Setting this is encouraged as it allows you to receive important
24063 notifications about the account and issued certificates.
24065 @item @code{server} (default: @code{#f})
24066 Optional URL of ACME server. Setting this overrides certbot's default,
24067 which is the Let's Encrypt server.
24069 @item @code{rsa-key-size} (default: @code{2048})
24070 Size of the RSA key.
24072 @item @code{default-location} (default: @i{see below})
24073 The default @code{nginx-location-configuration}. Because @code{certbot}
24074 needs to be able to serve challenges and responses, it needs to be able
24075 to run a web server. It does so by extending the @code{nginx} web
24076 service with an @code{nginx-server-configuration} listening on the
24077 @var{domains} on port 80, and which has a
24078 @code{nginx-location-configuration} for the @code{/.well-known/} URI
24079 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
24080 these nginx configuration data types.
24082 Requests to other URL paths will be matched by the
24083 @code{default-location}, which if present is added to all
24084 @code{nginx-server-configuration}s.
24086 By default, the @code{default-location} will issue a redirect from
24087 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
24088 you to define what to serve on your site via @code{https}.
24090 Pass @code{#f} to not issue a default location.
24094 @deftp {Data Type} certificate-configuration
24095 Data type representing the configuration of a certificate.
24096 This type has the following parameters:
24099 @item @code{name} (default: @i{see below})
24100 This name is used by Certbot for housekeeping and in file paths; it
24101 doesn't affect the content of the certificate itself. To see
24102 certificate names, run @code{certbot certificates}.
24104 Its default is the first provided domain.
24106 @item @code{domains} (default: @code{()})
24107 The first domain provided will be the subject CN of the certificate, and
24108 all domains will be Subject Alternative Names on the certificate.
24110 @item @code{challenge} (default: @code{#f})
24111 The challenge type that has to be run by certbot. If @code{#f} is specified,
24112 default to the HTTP challenge. If a value is specified, defaults to the
24113 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
24114 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
24115 and gives Let's Encrypt permission to log the public IP address of the
24116 requesting machine.
24118 @item @code{authentication-hook} (default: @code{#f})
24119 Command to be run in a shell once for each certificate challenge to be
24120 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
24121 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
24122 contains the validation string and @code{$CERTBOT_TOKEN} contains the
24123 file name of the resource requested when performing an HTTP-01 challenge.
24125 @item @code{cleanup-hook} (default: @code{#f})
24126 Command to be run in a shell once for each certificate challenge that
24127 have been answered by the @code{auth-hook}. For this command, the shell
24128 variables available in the @code{auth-hook} script are still available, and
24129 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
24130 of the @code{auth-hook} script.
24132 @item @code{deploy-hook} (default: @code{#f})
24133 Command to be run in a shell once for each successfully issued
24134 certificate. For this command, the shell variable
24135 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
24136 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
24137 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
24138 contain a space-delimited list of renewed certificate domains (for
24139 example, @samp{"example.com www.example.com"}.
24144 For each @code{certificate-configuration}, the certificate is saved to
24145 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
24146 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
24148 @subsection DNS Services
24149 @cindex DNS (domain name system)
24150 @cindex domain name system (DNS)
24152 The @code{(gnu services dns)} module provides services related to the
24153 @dfn{domain name system} (DNS). It provides a server service for hosting
24154 an @emph{authoritative} DNS server for multiple zones, slave or master.
24155 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
24156 caching and forwarding DNS server for the LAN, which uses
24157 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
24159 @subsubheading Knot Service
24161 An example configuration of an authoritative server for two zones, one master
24165 (define-zone-entries example.org.zone
24166 ;; Name TTL Class Type Data
24167 ("@@" "" "IN" "A" "127.0.0.1")
24168 ("@@" "" "IN" "NS" "ns")
24169 ("ns" "" "IN" "A" "127.0.0.1"))
24171 (define master-zone
24172 (knot-zone-configuration
24173 (domain "example.org")
24175 (origin "example.org")
24176 (entries example.org.zone)))))
24179 (knot-zone-configuration
24180 (domain "plop.org")
24181 (dnssec-policy "default")
24182 (master (list "plop-master"))))
24184 (define plop-master
24185 (knot-remote-configuration
24187 (address (list "208.76.58.171"))))
24191 (services (cons* (service knot-service-type
24192 (knot-configuration
24193 (remotes (list plop-master))
24194 (zones (list master-zone slave-zone))))
24199 @deffn {Scheme Variable} knot-service-type
24200 This is the type for the Knot DNS server.
24202 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
24203 zones, that is to say domain names you would buy from a registrar. This server
24204 is not a resolver, meaning that it can only resolve names for which it is
24205 authoritative. This server can be configured to serve zones as a master server
24206 or a slave server as a per-zone basis. Slave zones will get their data from
24207 masters, and will serve it as an authoritative server. From the point of view
24208 of a resolver, there is no difference between master and slave.
24210 The following data types are used to configure the Knot DNS server:
24213 @deftp {Data Type} knot-key-configuration
24214 Data type representing a key.
24215 This type has the following parameters:
24218 @item @code{id} (default: @code{""})
24219 An identifier for other configuration fields to refer to this key. IDs must
24220 be unique and must not be empty.
24222 @item @code{algorithm} (default: @code{#f})
24223 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
24224 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
24225 and @code{'hmac-sha512}.
24227 @item @code{secret} (default: @code{""})
24228 The secret key itself.
24233 @deftp {Data Type} knot-acl-configuration
24234 Data type representing an Access Control List (ACL) configuration.
24235 This type has the following parameters:
24238 @item @code{id} (default: @code{""})
24239 An identifier for other configuration fields to refer to this key. IDs must be
24240 unique and must not be empty.
24242 @item @code{address} (default: @code{'()})
24243 An ordered list of IP addresses, network subnets, or network ranges represented
24244 with strings. The query must match one of them. Empty value means that
24245 address match is not required.
24247 @item @code{key} (default: @code{'()})
24248 An ordered list of references to keys represented with strings. The string
24249 must match a key ID defined in a @code{knot-key-configuration}. No key means
24250 that a key is not require to match that ACL.
24252 @item @code{action} (default: @code{'()})
24253 An ordered list of actions that are permitted or forbidden by this ACL. Possible
24254 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
24255 and @code{'update}.
24257 @item @code{deny?} (default: @code{#f})
24258 When true, the ACL defines restrictions. Listed actions are forbidden. When
24259 false, listed actions are allowed.
24264 @deftp {Data Type} zone-entry
24265 Data type representing a record entry in a zone file.
24266 This type has the following parameters:
24269 @item @code{name} (default: @code{"@@"})
24270 The name of the record. @code{"@@"} refers to the origin of the zone. Names
24271 are relative to the origin of the zone. For example, in the @code{example.org}
24272 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
24273 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
24274 refers to @code{ns.example.org}.
24276 @item @code{ttl} (default: @code{""})
24277 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
24279 @item @code{class} (default: @code{"IN"})
24280 The class of the record. Knot currently supports only @code{"IN"} and
24281 partially @code{"CH"}.
24283 @item @code{type} (default: @code{"A"})
24284 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
24285 address), NS (Name Server) and MX (Mail eXchange). Many other types are
24288 @item @code{data} (default: @code{""})
24289 The data contained in the record. For instance an IP address associated with
24290 an A record, or a domain name associated with an NS record. Remember that
24291 domain names are relative to the origin unless they end with a dot.
24296 @deftp {Data Type} zone-file
24297 Data type representing the content of a zone file.
24298 This type has the following parameters:
24301 @item @code{entries} (default: @code{'()})
24302 The list of entries. The SOA record is taken care of, so you don't need to
24303 put it in the list of entries. This list should probably contain an entry
24304 for your primary authoritative DNS server. Other than using a list of entries
24305 directly, you can use @code{define-zone-entries} to define a object containing
24306 the list of entries more easily, that you can later pass to the @code{entries}
24307 field of the @code{zone-file}.
24309 @item @code{origin} (default: @code{""})
24310 The name of your zone. This parameter cannot be empty.
24312 @item @code{ns} (default: @code{"ns"})
24313 The domain of your primary authoritative DNS server. The name is relative to
24314 the origin, unless it ends with a dot. It is mandatory that this primary
24315 DNS server corresponds to an NS record in the zone and that it is associated
24316 to an IP address in the list of entries.
24318 @item @code{mail} (default: @code{"hostmaster"})
24319 An email address people can contact you at, as the owner of the zone. This
24320 is translated as @code{<mail>@@<origin>}.
24322 @item @code{serial} (default: @code{1})
24323 The serial number of the zone. As this is used to keep track of changes by
24324 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
24325 Always increment it when you make a change in your zone.
24327 @item @code{refresh} (default: @code{(* 2 24 3600)})
24328 The frequency at which slaves will do a zone transfer. This value is a number
24329 of seconds. It can be computed by multiplications or with
24330 @code{(string->duration)}.
24332 @item @code{retry} (default: @code{(* 15 60)})
24333 The period after which a slave will retry to contact its master when it fails
24334 to do so a first time.
24336 @item @code{expiry} (default: @code{(* 14 24 3600)})
24337 Default TTL of records. Existing records are considered correct for at most
24338 this amount of time. After this period, resolvers will invalidate their cache
24339 and check again that it still exists.
24341 @item @code{nx} (default: @code{3600})
24342 Default TTL of inexistant records. This delay is usually short because you want
24343 your new domains to reach everyone quickly.
24348 @deftp {Data Type} knot-remote-configuration
24349 Data type representing a remote configuration.
24350 This type has the following parameters:
24353 @item @code{id} (default: @code{""})
24354 An identifier for other configuration fields to refer to this remote. IDs must
24355 be unique and must not be empty.
24357 @item @code{address} (default: @code{'()})
24358 An ordered list of destination IP addresses. Addresses are tried in sequence.
24359 An optional port can be given with the @@ separator. For instance:
24360 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
24362 @item @code{via} (default: @code{'()})
24363 An ordered list of source IP addresses. An empty list will have Knot choose
24364 an appropriate source IP. An optional port can be given with the @@ separator.
24365 The default is to choose at random.
24367 @item @code{key} (default: @code{#f})
24368 A reference to a key, that is a string containing the identifier of a key
24369 defined in a @code{knot-key-configuration} field.
24374 @deftp {Data Type} knot-keystore-configuration
24375 Data type representing a keystore to hold dnssec keys.
24376 This type has the following parameters:
24379 @item @code{id} (default: @code{""})
24380 The id of the keystore. It must not be empty.
24382 @item @code{backend} (default: @code{'pem})
24383 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
24385 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
24386 The configuration string of the backend. An example for the PKCS#11 is:
24387 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
24388 For the pem backend, the string represents a path in the file system.
24393 @deftp {Data Type} knot-policy-configuration
24394 Data type representing a dnssec policy. Knot DNS is able to automatically
24395 sign your zones. It can either generate and manage your keys automatically or
24396 use keys that you generate.
24398 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
24399 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
24400 zone. In order to be trusted, the KSK needs to be present in the parent zone
24401 (usually a top-level domain). If your registrar supports dnssec, you will
24402 have to send them your KSK's hash so they can add a DS record in their zone.
24403 This is not automated and need to be done each time you change your KSK.
24405 The policy also defines the lifetime of keys. Usually, ZSK can be changed
24406 easily and use weaker cryptographic functions (they use lower parameters) in
24407 order to sign records quickly, so they are changed often. The KSK however
24408 requires manual interaction with the registrar, so they are changed less often
24409 and use stronger parameters because they sign only one record.
24411 This type has the following parameters:
24414 @item @code{id} (default: @code{""})
24415 The id of the policy. It must not be empty.
24417 @item @code{keystore} (default: @code{"default"})
24418 A reference to a keystore, that is a string containing the identifier of a
24419 keystore defined in a @code{knot-keystore-configuration} field. The
24420 @code{"default"} identifier means the default keystore (a kasp database that
24421 was setup by this service).
24423 @item @code{manual?} (default: @code{#f})
24424 Whether the key management is manual or automatic.
24426 @item @code{single-type-signing?} (default: @code{#f})
24427 When @code{#t}, use the Single-Type Signing Scheme.
24429 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
24430 An algorithm of signing keys and issued signatures.
24432 @item @code{ksk-size} (default: @code{256})
24433 The length of the KSK. Note that this value is correct for the default
24434 algorithm, but would be unsecure for other algorithms.
24436 @item @code{zsk-size} (default: @code{256})
24437 The length of the ZSK. Note that this value is correct for the default
24438 algorithm, but would be unsecure for other algorithms.
24440 @item @code{dnskey-ttl} (default: @code{'default})
24441 The TTL value for DNSKEY records added into zone apex. The special
24442 @code{'default} value means same as the zone SOA TTL.
24444 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
24445 The period between ZSK publication and the next rollover initiation.
24447 @item @code{propagation-delay} (default: @code{(* 24 3600)})
24448 An extra delay added for each key rollover step. This value should be high
24449 enough to cover propagation of data from the master server to all slaves.
24451 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
24452 A validity period of newly issued signatures.
24454 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
24455 A period how long before a signature expiration the signature will be refreshed.
24457 @item @code{nsec3?} (default: @code{#f})
24458 When @code{#t}, NSEC3 will be used instead of NSEC.
24460 @item @code{nsec3-iterations} (default: @code{5})
24461 The number of additional times the hashing is performed.
24463 @item @code{nsec3-salt-length} (default: @code{8})
24464 The length of a salt field in octets, which is appended to the original owner
24465 name before hashing.
24467 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
24468 The validity period of newly issued salt field.
24473 @deftp {Data Type} knot-zone-configuration
24474 Data type representing a zone served by Knot.
24475 This type has the following parameters:
24478 @item @code{domain} (default: @code{""})
24479 The domain served by this configuration. It must not be empty.
24481 @item @code{file} (default: @code{""})
24482 The file where this zone is saved. This parameter is ignored by master zones.
24483 Empty means default location that depends on the domain name.
24485 @item @code{zone} (default: @code{(zone-file)})
24486 The content of the zone file. This parameter is ignored by slave zones. It
24487 must contain a zone-file record.
24489 @item @code{master} (default: @code{'()})
24490 A list of master remotes. When empty, this zone is a master. When set, this
24491 zone is a slave. This is a list of remotes identifiers.
24493 @item @code{ddns-master} (default: @code{#f})
24494 The main master. When empty, it defaults to the first master in the list of
24497 @item @code{notify} (default: @code{'()})
24498 A list of slave remote identifiers.
24500 @item @code{acl} (default: @code{'()})
24501 A list of acl identifiers.
24503 @item @code{semantic-checks?} (default: @code{#f})
24504 When set, this adds more semantic checks to the zone.
24506 @item @code{disable-any?} (default: @code{#f})
24507 When set, this forbids queries of the ANY type.
24509 @item @code{zonefile-sync} (default: @code{0})
24510 The delay between a modification in memory and on disk. 0 means immediate
24513 @item @code{zonefile-load} (default: @code{#f})
24514 The way the zone file contents are applied during zone load. Possible values
24518 @item @code{#f} for using the default value from Knot,
24519 @item @code{'none} for not using the zone file at all,
24520 @item @code{'difference} for computing the difference between already available
24521 contents and zone contents and applying it to the current zone contents,
24522 @item @code{'difference-no-serial} for the same as @code{'difference}, but
24523 ignoring the SOA serial in the zone file, while the server takes care of it
24525 @item @code{'whole} for loading zone contents from the zone file.
24528 @item @code{journal-content} (default: @code{#f})
24529 The way the journal is used to store zone and its changes. Possible values
24530 are @code{'none} to not use it at all, @code{'changes} to store changes and
24531 @code{'all} to store contents. @code{#f} does not set this option, so the
24532 default value from Knot is used.
24534 @item @code{max-journal-usage} (default: @code{#f})
24535 The maximum size for the journal on disk. @code{#f} does not set this option,
24536 so the default value from Knot is used.
24538 @item @code{max-journal-depth} (default: @code{#f})
24539 The maximum size of the history. @code{#f} does not set this option, so the
24540 default value from Knot is used.
24542 @item @code{max-zone-size} (default: @code{#f})
24543 The maximum size of the zone file. This limit is enforced for incoming
24544 transfer and updates. @code{#f} does not set this option, so the default
24545 value from Knot is used.
24547 @item @code{dnssec-policy} (default: @code{#f})
24548 A reference to a @code{knot-policy-configuration} record, or the special
24549 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
24552 @item @code{serial-policy} (default: @code{'increment})
24553 A policy between @code{'increment} and @code{'unixtime}.
24558 @deftp {Data Type} knot-configuration
24559 Data type representing the Knot configuration.
24560 This type has the following parameters:
24563 @item @code{knot} (default: @code{knot})
24566 @item @code{run-directory} (default: @code{"/var/run/knot"})
24567 The run directory. This directory will be used for pid file and sockets.
24569 @item @code{includes} (default: @code{'()})
24570 A list of strings or file-like objects denoting other files that must be
24571 included at the top of the configuration file.
24573 @cindex secrets, Knot service
24574 This can be used to manage secrets out-of-band. For example, secret
24575 keys may be stored in an out-of-band file not managed by Guix, and
24576 thus not visible in @file{/gnu/store}---e.g., you could store secret
24577 key configuration in @file{/etc/knot/secrets.conf} and add this file
24578 to the @code{includes} list.
24580 One can generate a secret tsig key (for nsupdate and zone transfers with the
24581 keymgr command from the knot package. Note that the package is not automatically
24582 installed by the service. The following example shows how to generate a new
24586 keymgr -t mysecret > /etc/knot/secrets.conf
24587 chmod 600 /etc/knot/secrets.conf
24590 Also note that the generated key will be named @var{mysecret}, so it is the
24591 name that needs to be used in the @var{key} field of the
24592 @code{knot-acl-configuration} record and in other places that need to refer
24595 It can also be used to add configuration not supported by this interface.
24597 @item @code{listen-v4} (default: @code{"0.0.0.0"})
24598 An ip address on which to listen.
24600 @item @code{listen-v6} (default: @code{"::"})
24601 An ip address on which to listen.
24603 @item @code{listen-port} (default: @code{53})
24604 A port on which to listen.
24606 @item @code{keys} (default: @code{'()})
24607 The list of knot-key-configuration used by this configuration.
24609 @item @code{acls} (default: @code{'()})
24610 The list of knot-acl-configuration used by this configuration.
24612 @item @code{remotes} (default: @code{'()})
24613 The list of knot-remote-configuration used by this configuration.
24615 @item @code{zones} (default: @code{'()})
24616 The list of knot-zone-configuration used by this configuration.
24621 @subsubheading Knot Resolver Service
24623 @deffn {Scheme Variable} knot-resolver-service-type
24624 This is the type of the knot resolver service, whose value should be
24625 an @code{knot-resolver-configuration} object as in this example:
24628 (service knot-resolver-service-type
24629 (knot-resolver-configuration
24630 (kresd-config-file (plain-file "kresd.conf" "
24631 net.listen('192.168.0.1', 5353)
24632 user('knot-resolver', 'knot-resolver')
24633 modules = @{ 'hints > iterate', 'stats', 'predict' @}
24634 cache.size = 100 * MB
24638 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
24641 @deftp {Data Type} knot-resolver-configuration
24642 Data type representing the configuration of knot-resolver.
24645 @item @code{package} (default: @var{knot-resolver})
24646 Package object of the knot DNS resolver.
24648 @item @code{kresd-config-file} (default: %kresd.conf)
24649 File-like object of the kresd configuration file to use, by default it
24650 will listen on @code{127.0.0.1} and @code{::1}.
24652 @item @code{garbage-collection-interval} (default: 1000)
24653 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
24659 @subsubheading Dnsmasq Service
24661 @deffn {Scheme Variable} dnsmasq-service-type
24662 This is the type of the dnsmasq service, whose value should be an
24663 @code{dnsmasq-configuration} object as in this example:
24666 (service dnsmasq-service-type
24667 (dnsmasq-configuration
24669 (servers '("192.168.1.1"))))
24673 @deftp {Data Type} dnsmasq-configuration
24674 Data type representing the configuration of dnsmasq.
24677 @item @code{package} (default: @var{dnsmasq})
24678 Package object of the dnsmasq server.
24680 @item @code{no-hosts?} (default: @code{#f})
24681 When true, don't read the hostnames in /etc/hosts.
24683 @item @code{port} (default: @code{53})
24684 The port to listen on. Setting this to zero completely disables DNS
24685 responses, leaving only DHCP and/or TFTP functions.
24687 @item @code{local-service?} (default: @code{#t})
24688 Accept DNS queries only from hosts whose address is on a local subnet,
24689 ie a subnet for which an interface exists on the server.
24691 @item @code{listen-addresses} (default: @code{'()})
24692 Listen on the given IP addresses.
24694 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
24695 The file to read the IP address of the upstream nameservers from.
24697 @item @code{no-resolv?} (default: @code{#f})
24698 When true, don't read @var{resolv-file}.
24700 @item @code{servers} (default: @code{'()})
24701 Specify IP address of upstream servers directly.
24703 @item @code{addresses} (default: @code{'()})
24704 For each entry, specify an IP address to return for any host in the
24705 given domains. Queries in the domains are never forwarded and always
24706 replied to with the specified IP address.
24708 This is useful for redirecting hosts locally, for example:
24711 (service dnsmasq-service-type
24712 (dnsmasq-configuration
24714 '(; Redirect to a local web-server.
24715 "/example.org/127.0.0.1"
24716 ; Redirect subdomain to a specific IP.
24717 "/subdomain.example.org/192.168.1.42"))))
24720 Note that rules in @file{/etc/hosts} take precedence over this.
24722 @item @code{cache-size} (default: @code{150})
24723 Set the size of dnsmasq's cache. Setting the cache size to zero
24726 @item @code{negative-cache?} (default: @code{#t})
24727 When false, disable negative caching.
24729 @item @code{tftp-enable?} (default: @code{#f})
24730 Whether to enable the built-in TFTP server.
24732 @item @code{tftp-no-fail?} (default: @code{#f})
24733 If true, does not fail dnsmasq if the TFTP server could not start up.
24735 @item @code{tftp-single-port?} (default: @code{#f})
24736 Whether to use only one single port for TFTP.
24738 @item @code{tftp-secure?} (default: @code{#f})
24739 If true, only files owned by the user running the dnsmasq process are accessible.
24741 If dnsmasq is being run as root, different rules apply:
24742 @code{tftp-secure?} has no effect, but only files which have the
24743 world-readable bit set are accessible.
24745 @item @code{tftp-max} (default: @code{#f})
24746 If set, sets the maximal number of concurrent connections allowed.
24748 @item @code{tftp-mtu} (default: @code{#f})
24749 If set, sets the MTU for TFTP packets to that value.
24751 @item @code{tftp-no-blocksize?} (default: @code{#f})
24752 If true, stops the TFTP server from negotiating the blocksize with a client.
24754 @item @code{tftp-lowercase?} (default: @code{#f})
24755 Whether to convert all filenames in TFTP requests to lowercase.
24757 @item @code{tftp-port-range} (default: @code{#f})
24758 If set, fixes the dynamical ports (one per client) to the given range
24759 (@code{"<start>,<end>"}).
24761 @item @code{tftp-root} (default: @code{/var/empty,lo})
24762 Look for files to transfer using TFTP relative to the given directory.
24763 When this is set, TFTP paths which include ".." are rejected, to stop clients
24764 getting outside the specified root. Absolute paths (starting with /) are
24765 allowed, but they must be within the tftp-root. If the optional interface
24766 argument is given, the directory is only used for TFTP requests via that
24769 @item @code{tftp-unique-root} (default: @code{#f})
24770 If set, add the IP or hardware address of the TFTP client as a path component
24771 on the end of the TFTP-root. Only valid if a TFTP root is set and the
24772 directory exists. Defaults to adding IP address (in standard dotted-quad
24775 For instance, if --tftp-root is "/tftp" and client 1.2.3.4 requests file
24776 "myfile" then the effective path will be "/tftp/1.2.3.4/myfile" if
24777 /tftp/1.2.3.4 exists or /tftp/myfile otherwise. When "=mac" is specified
24778 it will append the MAC address instead, using lowercase zero padded digits
24779 separated by dashes, e.g.: 01-02-03-04-aa-bb Note that resolving MAC
24780 addresses is only possible if the client is in the local network or obtained
24781 a DHCP lease from dnsmasq.
24786 @subsubheading ddclient Service
24789 The ddclient service described below runs the ddclient daemon, which takes
24790 care of automatically updating DNS entries for service providers such as
24791 @uref{https://dyn.com/dns/, Dyn}.
24793 The following example show instantiates the service with its default
24797 (service ddclient-service-type)
24800 Note that ddclient needs to access credentials that are stored in a
24801 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
24802 @code{secret-file} below). You are expected to create this file manually, in
24803 an ``out-of-band'' fashion (you @emph{could} make this file part of the
24804 service configuration, for instance by using @code{plain-file}, but it will be
24805 world-readable @i{via} @file{/gnu/store}). See the examples in the
24806 @file{share/ddclient} directory of the @code{ddclient} package.
24808 @c %start of fragment
24810 Available @code{ddclient-configuration} fields are:
24812 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
24813 The ddclient package.
24817 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
24818 The period after which ddclient will retry to check IP and domain name.
24820 Defaults to @samp{300}.
24824 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
24825 Use syslog for the output.
24827 Defaults to @samp{#t}.
24831 @deftypevr {@code{ddclient-configuration} parameter} string mail
24834 Defaults to @samp{"root"}.
24838 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
24839 Mail failed update to user.
24841 Defaults to @samp{"root"}.
24845 @deftypevr {@code{ddclient-configuration} parameter} string pid
24846 The ddclient PID file.
24848 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
24852 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
24853 Enable SSL support.
24855 Defaults to @samp{#t}.
24859 @deftypevr {@code{ddclient-configuration} parameter} string user
24860 Specifies the user name or ID that is used when running ddclient
24863 Defaults to @samp{"ddclient"}.
24867 @deftypevr {@code{ddclient-configuration} parameter} string group
24868 Group of the user who will run the ddclient program.
24870 Defaults to @samp{"ddclient"}.
24874 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
24875 Secret file which will be appended to @file{ddclient.conf} file. This
24876 file contains credentials for use by ddclient. You are expected to
24877 create it manually.
24879 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
24883 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
24884 Extra options will be appended to @file{ddclient.conf} file.
24886 Defaults to @samp{()}.
24891 @c %end of fragment
24895 @subsection VPN Services
24896 @cindex VPN (virtual private network)
24897 @cindex virtual private network (VPN)
24899 The @code{(gnu services vpn)} module provides services related to
24900 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
24901 your machine to connect to a VPN, and a @emph{server} service for your machine
24902 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
24904 @deffn {Scheme Procedure} openvpn-client-service @
24905 [#:config (openvpn-client-configuration)]
24907 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
24910 @deffn {Scheme Procedure} openvpn-server-service @
24911 [#:config (openvpn-server-configuration)]
24913 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
24915 Both can be run simultaneously.
24918 @c %automatically generated documentation
24920 Available @code{openvpn-client-configuration} fields are:
24922 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
24923 The OpenVPN package.
24927 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
24928 The OpenVPN pid file.
24930 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
24934 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
24935 The protocol (UDP or TCP) used to open a channel between clients and
24938 Defaults to @samp{udp}.
24942 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
24943 The device type used to represent the VPN connection.
24945 Defaults to @samp{tun}.
24949 If you do not have some of these files (eg.@: you use a username and
24950 password), you can disable any of the following three fields by setting
24951 it to @code{'disabled}.
24953 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string ca
24954 The certificate authority to check connections against.
24956 Defaults to @samp{"/etc/openvpn/ca.crt"}.
24960 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string cert
24961 The certificate of the machine the daemon is running on. It should be
24962 signed by the authority given in @code{ca}.
24964 Defaults to @samp{"/etc/openvpn/client.crt"}.
24968 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string key
24969 The key of the machine the daemon is running on. It must be the key whose
24970 certificate is @code{cert}.
24972 Defaults to @samp{"/etc/openvpn/client.key"}.
24976 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
24977 Whether to use the lzo compression algorithm.
24979 Defaults to @samp{#t}.
24983 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
24984 Don't re-read key files across SIGUSR1 or --ping-restart.
24986 Defaults to @samp{#t}.
24990 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
24991 Don't close and reopen TUN/TAP device or run up/down scripts across
24992 SIGUSR1 or --ping-restart restarts.
24994 Defaults to @samp{#t}.
24998 @deftypevr {@code{openvpn-client-configuration} parameter} boolean fast-io?
24999 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
25000 poll/epoll/select prior to the write operation.
25002 Defaults to @samp{#f}.
25005 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
25008 Defaults to @samp{3}.
25012 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
25013 Add an additional layer of HMAC authentication on top of the TLS control
25014 channel to protect against DoS attacks.
25016 Defaults to @samp{#f}.
25020 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string auth-user-pass
25021 Authenticate with server using username/password. The option is a file
25022 containing username/password on 2 lines. Do not use a file-like object as it
25023 would be added to the store and readable by any user.
25025 Defaults to @samp{'disabled}.
25028 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
25029 Whether to check the server certificate has server usage extension.
25031 Defaults to @samp{#t}.
25035 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
25036 Bind to a specific local port number.
25038 Defaults to @samp{#f}.
25042 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
25043 Retry resolving server address.
25045 Defaults to @samp{#t}.
25049 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
25050 A list of remote servers to connect to.
25052 Defaults to @samp{()}.
25054 Available @code{openvpn-remote-configuration} fields are:
25056 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
25059 Defaults to @samp{"my-server"}.
25063 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
25064 Port number the server listens to.
25066 Defaults to @samp{1194}.
25071 @c %end of automatic openvpn-client documentation
25073 @c %automatically generated documentation
25075 Available @code{openvpn-server-configuration} fields are:
25077 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
25078 The OpenVPN package.
25082 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
25083 The OpenVPN pid file.
25085 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
25089 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
25090 The protocol (UDP or TCP) used to open a channel between clients and
25093 Defaults to @samp{udp}.
25097 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
25098 The device type used to represent the VPN connection.
25100 Defaults to @samp{tun}.
25104 If you do not have some of these files (eg.@: you use a username and
25105 password), you can disable any of the following three fields by setting
25106 it to @code{'disabled}.
25108 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string ca
25109 The certificate authority to check connections against.
25111 Defaults to @samp{"/etc/openvpn/ca.crt"}.
25115 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string cert
25116 The certificate of the machine the daemon is running on. It should be
25117 signed by the authority given in @code{ca}.
25119 Defaults to @samp{"/etc/openvpn/client.crt"}.
25123 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string key
25124 The key of the machine the daemon is running on. It must be the key whose
25125 certificate is @code{cert}.
25127 Defaults to @samp{"/etc/openvpn/client.key"}.
25131 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
25132 Whether to use the lzo compression algorithm.
25134 Defaults to @samp{#t}.
25138 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
25139 Don't re-read key files across SIGUSR1 or --ping-restart.
25141 Defaults to @samp{#t}.
25145 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
25146 Don't close and reopen TUN/TAP device or run up/down scripts across
25147 SIGUSR1 or --ping-restart restarts.
25149 Defaults to @samp{#t}.
25153 @deftypevr {@code{openvpn-server-configuration} parameter} boolean fast-io?
25154 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
25155 poll/epoll/select prior to the write operation.
25157 Defaults to @samp{#f}.
25160 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
25163 Defaults to @samp{3}.
25167 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
25168 Add an additional layer of HMAC authentication on top of the TLS control
25169 channel to protect against DoS attacks.
25171 Defaults to @samp{#f}.
25175 @deftypevr {@code{openvpn-server-configuration} parameter} number port
25176 Specifies the port number on which the server listens.
25178 Defaults to @samp{1194}.
25182 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
25183 An ip and mask specifying the subnet inside the virtual network.
25185 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
25189 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
25190 A CIDR notation specifying the IPv6 subnet inside the virtual network.
25192 Defaults to @samp{#f}.
25196 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
25197 The Diffie-Hellman parameters file.
25199 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
25203 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
25204 The file that records client IPs.
25206 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
25210 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
25211 When true, the server will act as a gateway for its clients.
25213 Defaults to @samp{#f}.
25217 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
25218 When true, clients are allowed to talk to each other inside the VPN.
25220 Defaults to @samp{#f}.
25224 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
25225 Causes ping-like messages to be sent back and forth over the link so
25226 that each side knows when the other side has gone down. @code{keepalive}
25227 requires a pair. The first element is the period of the ping sending,
25228 and the second element is the timeout before considering the other side
25233 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
25234 The maximum number of clients.
25236 Defaults to @samp{100}.
25240 @deftypevr {@code{openvpn-server-configuration} parameter} string status
25241 The status file. This file shows a small report on current connection.
25242 It is truncated and rewritten every minute.
25244 Defaults to @samp{"/var/run/openvpn/status"}.
25248 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
25249 The list of configuration for some clients.
25251 Defaults to @samp{()}.
25253 Available @code{openvpn-ccd-configuration} fields are:
25255 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
25258 Defaults to @samp{"client"}.
25262 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
25265 Defaults to @samp{#f}.
25269 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
25272 Defaults to @samp{#f}.
25279 @c %end of automatic openvpn-server documentation
25282 @node Network File System
25283 @subsection Network File System
25286 The @code{(gnu services nfs)} module provides the following services,
25287 which are most commonly used in relation to mounting or exporting
25288 directory trees as @dfn{network file systems} (NFS).
25290 While it is possible to use the individual components that together make
25291 up a Network File System service, we recommended to configure an NFS
25292 server with the @code{nfs-service-type}.
25294 @subsubheading NFS Service
25295 @cindex NFS, server
25297 The NFS service takes care of setting up all NFS component services,
25298 kernel configuration file systems, and installs configuration files in
25299 the locations that NFS expects.
25301 @defvr {Scheme Variable} nfs-service-type
25302 A service type for a complete NFS server.
25305 @deftp {Data Type} nfs-configuration
25306 This data type represents the configuration of the NFS service and all
25309 It has the following parameters:
25311 @item @code{nfs-utils} (default: @code{nfs-utils})
25312 The nfs-utils package to use.
25314 @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
25315 If a list of string values is provided, the @command{rpc.nfsd} daemon
25316 will be limited to supporting the given versions of the NFS protocol.
25318 @item @code{exports} (default: @code{'()})
25319 This is a list of directories the NFS server should export. Each entry
25320 is a list consisting of two elements: a directory name and a string
25321 containing all options. This is an example in which the directory
25322 @file{/export} is served to all NFS clients as a read-only share:
25328 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
25331 @item @code{rpcmountd-port} (default: @code{#f})
25332 The network port that the @command{rpc.mountd} daemon should use.
25334 @item @code{rpcstatd-port} (default: @code{#f})
25335 The network port that the @command{rpc.statd} daemon should use.
25337 @item @code{rpcbind} (default: @code{rpcbind})
25338 The rpcbind package to use.
25340 @item @code{idmap-domain} (default: @code{"localdomain"})
25341 The local NFSv4 domain name.
25343 @item @code{nfsd-port} (default: @code{2049})
25344 The network port that the @command{nfsd} daemon should use.
25346 @item @code{nfsd-threads} (default: @code{8})
25347 The number of threads used by the @command{nfsd} daemon.
25349 @item @code{nfsd-tcp?} (default: @code{#t})
25350 Whether the @command{nfsd} daemon should listen on a TCP socket.
25352 @item @code{nfsd-udp?} (default: @code{#f})
25353 Whether the @command{nfsd} daemon should listen on a UDP socket.
25355 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
25356 The directory where the pipefs file system is mounted.
25358 @item @code{debug} (default: @code{'()"})
25359 A list of subsystems for which debugging output should be enabled. This
25360 is a list of symbols. Any of these symbols are valid: @code{nfsd},
25361 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
25365 If you don't need a complete NFS service or prefer to build it yourself
25366 you can use the individual component services that are documented below.
25368 @subsubheading RPC Bind Service
25371 The RPC Bind service provides a facility to map program numbers into
25372 universal addresses.
25373 Many NFS related services use this facility. Hence it is automatically
25374 started when a dependent service starts.
25376 @defvr {Scheme Variable} rpcbind-service-type
25377 A service type for the RPC portmapper daemon.
25381 @deftp {Data Type} rpcbind-configuration
25382 Data type representing the configuration of the RPC Bind Service.
25383 This type has the following parameters:
25385 @item @code{rpcbind} (default: @code{rpcbind})
25386 The rpcbind package to use.
25388 @item @code{warm-start?} (default: @code{#t})
25389 If this parameter is @code{#t}, then the daemon will read a
25390 state file on startup thus reloading state information saved by a previous
25396 @subsubheading Pipefs Pseudo File System
25400 The pipefs file system is used to transfer NFS related data
25401 between the kernel and user space programs.
25403 @defvr {Scheme Variable} pipefs-service-type
25404 A service type for the pipefs pseudo file system.
25407 @deftp {Data Type} pipefs-configuration
25408 Data type representing the configuration of the pipefs pseudo file system service.
25409 This type has the following parameters:
25411 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
25412 The directory to which the file system is to be attached.
25417 @subsubheading GSS Daemon Service
25420 @cindex global security system
25422 The @dfn{global security system} (GSS) daemon provides strong security for RPC
25424 Before exchanging RPC requests an RPC client must establish a security
25425 context. Typically this is done using the Kerberos command @command{kinit}
25426 or automatically at login time using PAM services (@pxref{Kerberos Services}).
25428 @defvr {Scheme Variable} gss-service-type
25429 A service type for the Global Security System (GSS) daemon.
25432 @deftp {Data Type} gss-configuration
25433 Data type representing the configuration of the GSS daemon service.
25434 This type has the following parameters:
25436 @item @code{nfs-utils} (default: @code{nfs-utils})
25437 The package in which the @command{rpc.gssd} command is to be found.
25439 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
25440 The directory where the pipefs file system is mounted.
25446 @subsubheading IDMAP Daemon Service
25448 @cindex name mapper
25450 The idmap daemon service provides mapping between user IDs and user names.
25451 Typically it is required in order to access file systems mounted via NFSv4.
25453 @defvr {Scheme Variable} idmap-service-type
25454 A service type for the Identity Mapper (IDMAP) daemon.
25457 @deftp {Data Type} idmap-configuration
25458 Data type representing the configuration of the IDMAP daemon service.
25459 This type has the following parameters:
25461 @item @code{nfs-utils} (default: @code{nfs-utils})
25462 The package in which the @command{rpc.idmapd} command is to be found.
25464 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
25465 The directory where the pipefs file system is mounted.
25467 @item @code{domain} (default: @code{#f})
25468 The local NFSv4 domain name.
25469 This must be a string or @code{#f}.
25470 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
25472 @item @code{verbosity} (default: @code{0})
25473 The verbosity level of the daemon.
25478 @node Continuous Integration
25479 @subsection Continuous Integration
25481 @cindex continuous integration
25482 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
25483 continuous integration tool for Guix. It can be used both for development and
25484 for providing substitutes to others (@pxref{Substitutes}).
25486 The @code{(gnu services cuirass)} module provides the following service.
25488 @defvr {Scheme Procedure} cuirass-service-type
25489 The type of the Cuirass service. Its value must be a
25490 @code{cuirass-configuration} object, as described below.
25493 To add build jobs, you have to set the @code{specifications} field of the
25494 configuration. Here is an example of a service that polls the Guix repository
25495 and builds the packages from a manifest. Some of the packages are defined in
25496 the @code{"custom-packages"} input, which is the equivalent of
25497 @env{GUIX_PACKAGE_PATH}.
25500 (define %cuirass-specs
25502 '((#:name . "my-manifest")
25503 (#:load-path-inputs . ("guix"))
25504 (#:package-path-inputs . ("custom-packages"))
25505 (#:proc-input . "guix")
25506 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
25507 (#:proc . cuirass-jobs)
25508 (#:proc-args . ((subset . "manifests")
25509 (systems . ("x86_64-linux"))
25510 (manifests . (("config" . "guix/manifest.scm")))))
25511 (#:inputs . (((#:name . "guix")
25512 (#:url . "git://git.savannah.gnu.org/guix.git")
25513 (#:load-path . ".")
25514 (#:branch . "master")
25515 (#:no-compile? . #t))
25516 ((#:name . "config")
25517 (#:url . "https://git.example.org/config.git")
25518 (#:load-path . ".")
25519 (#:branch . "master")
25520 (#:no-compile? . #t))
25521 ((#:name . "custom-packages")
25522 (#:url . "https://git.example.org/custom-packages.git")
25523 (#:load-path . ".")
25524 (#:branch . "master")
25525 (#:no-compile? . #t)))))))
25527 (service cuirass-service-type
25528 (cuirass-configuration
25529 (specifications %cuirass-specs)))
25532 While information related to build jobs is located directly in the
25533 specifications, global settings for the @command{cuirass} process are
25534 accessible in other @code{cuirass-configuration} fields.
25536 @deftp {Data Type} cuirass-configuration
25537 Data type representing the configuration of Cuirass.
25540 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
25541 Location of the log file.
25543 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
25544 Location of the log file used by the web interface.
25546 @item @code{queries-log-file} (default: @code{#f})
25547 Location of the SQL queries log file. By default, SQL queries logging is
25550 @item @code{web-queries-log-file} (default: @code{#f})
25551 Location of the web SQL queries log file. By default, web SQL queries
25552 logging is disabled.
25554 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
25555 Location of the repository cache.
25557 @item @code{user} (default: @code{"cuirass"})
25558 Owner of the @code{cuirass} process.
25560 @item @code{group} (default: @code{"cuirass"})
25561 Owner's group of the @code{cuirass} process.
25563 @item @code{interval} (default: @code{60})
25564 Number of seconds between the poll of the repositories followed by the
25567 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
25568 Location of sqlite database which contains the build results and previously
25569 added specifications.
25571 @item @code{ttl} (default: @code{(* 30 24 3600)})
25572 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
25573 are registered for build results. This means that build results are protected
25574 from garbage collection for at least @var{ttl} seconds.
25576 @item @code{port} (default: @code{8081})
25577 Port number used by the HTTP server.
25579 @item @code{host} (default: @code{"localhost"})
25580 Listen on the network interface for @var{host}. The default is to
25581 accept connections from localhost.
25583 @item @code{specifications} (default: @code{#~'()})
25584 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
25585 where a specification is an association list
25586 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
25587 keys are keywords (@code{#:keyword-example}) as shown in the example
25590 @item @code{use-substitutes?} (default: @code{#f})
25591 This allows using substitutes to avoid building every dependencies of a job
25594 @item @code{one-shot?} (default: @code{#f})
25595 Only evaluate specifications and build derivations once.
25597 @item @code{fallback?} (default: @code{#f})
25598 When substituting a pre-built binary fails, fall back to building
25601 @item @code{extra-options} (default: @code{'()})
25602 Extra options to pass when running the Cuirass processes.
25604 @item @code{cuirass} (default: @code{cuirass})
25605 The Cuirass package to use.
25609 @node Power Management Services
25610 @subsection Power Management Services
25613 @cindex power management with TLP
25614 @subsubheading TLP daemon
25616 The @code{(gnu services pm)} module provides a Guix service definition
25617 for the Linux power management tool TLP.
25619 TLP enables various powersaving modes in userspace and kernel.
25620 Contrary to @code{upower-service}, it is not a passive,
25621 monitoring tool, as it will apply custom settings each time a new power
25622 source is detected. More information can be found at
25623 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
25625 @deffn {Scheme Variable} tlp-service-type
25626 The service type for the TLP tool. The default settings are optimised
25627 for battery life on most systems, but you can tweak them to your heart's
25628 content by adding a valid @code{tlp-configuration}:
25630 (service tlp-service-type
25632 (cpu-scaling-governor-on-ac (list "performance"))
25633 (sched-powersave-on-bat? #t)))
25637 Each parameter definition is preceded by its type; for example,
25638 @samp{boolean foo} indicates that the @code{foo} parameter
25639 should be specified as a boolean. Types starting with
25640 @code{maybe-} denote parameters that won't show up in TLP config file
25641 when their value is @code{'disabled}.
25643 @c The following documentation was initially generated by
25644 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
25645 @c documentation is better, so we shouldn't hesitate to edit below as
25646 @c needed. However if the change you want to make to this documentation
25647 @c can be done in an automated way, it's probably easier to change
25648 @c (generate-documentation) than to make it below and have to deal with
25649 @c the churn as TLP updates.
25651 Available @code{tlp-configuration} fields are:
25653 @deftypevr {@code{tlp-configuration} parameter} package tlp
25658 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
25659 Set to true if you wish to enable TLP.
25661 Defaults to @samp{#t}.
25665 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
25666 Default mode when no power supply can be detected. Alternatives are AC
25669 Defaults to @samp{"AC"}.
25673 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
25674 Number of seconds Linux kernel has to wait after the disk goes idle,
25675 before syncing on AC.
25677 Defaults to @samp{0}.
25681 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
25682 Same as @code{disk-idle-ac} but on BAT mode.
25684 Defaults to @samp{2}.
25688 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
25689 Dirty pages flushing periodicity, expressed in seconds.
25691 Defaults to @samp{15}.
25695 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
25696 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
25698 Defaults to @samp{60}.
25702 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
25703 CPU frequency scaling governor on AC mode. With intel_pstate driver,
25704 alternatives are powersave and performance. With acpi-cpufreq driver,
25705 alternatives are ondemand, powersave, performance and conservative.
25707 Defaults to @samp{disabled}.
25711 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
25712 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
25714 Defaults to @samp{disabled}.
25718 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
25719 Set the min available frequency for the scaling governor on AC.
25721 Defaults to @samp{disabled}.
25725 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
25726 Set the max available frequency for the scaling governor on AC.
25728 Defaults to @samp{disabled}.
25732 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
25733 Set the min available frequency for the scaling governor on BAT.
25735 Defaults to @samp{disabled}.
25739 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
25740 Set the max available frequency for the scaling governor on BAT.
25742 Defaults to @samp{disabled}.
25746 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
25747 Limit the min P-state to control the power dissipation of the CPU, in AC
25748 mode. Values are stated as a percentage of the available performance.
25750 Defaults to @samp{disabled}.
25754 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
25755 Limit the max P-state to control the power dissipation of the CPU, in AC
25756 mode. Values are stated as a percentage of the available performance.
25758 Defaults to @samp{disabled}.
25762 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
25763 Same as @code{cpu-min-perf-on-ac} on BAT mode.
25765 Defaults to @samp{disabled}.
25769 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
25770 Same as @code{cpu-max-perf-on-ac} on BAT mode.
25772 Defaults to @samp{disabled}.
25776 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
25777 Enable CPU turbo boost feature on AC mode.
25779 Defaults to @samp{disabled}.
25783 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
25784 Same as @code{cpu-boost-on-ac?} on BAT mode.
25786 Defaults to @samp{disabled}.
25790 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
25791 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
25792 used under light load conditions.
25794 Defaults to @samp{#f}.
25798 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
25799 Same as @code{sched-powersave-on-ac?} but on BAT mode.
25801 Defaults to @samp{#t}.
25805 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
25806 Enable Linux kernel NMI watchdog.
25808 Defaults to @samp{#f}.
25812 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
25813 For Linux kernels with PHC patch applied, change CPU voltages. An
25814 example value would be @samp{"F:V F:V F:V F:V"}.
25816 Defaults to @samp{disabled}.
25820 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
25821 Set CPU performance versus energy saving policy on AC. Alternatives are
25822 performance, normal, powersave.
25824 Defaults to @samp{"performance"}.
25828 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
25829 Same as @code{energy-perf-policy-ac} but on BAT mode.
25831 Defaults to @samp{"powersave"}.
25835 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
25840 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
25841 Hard disk advanced power management level.
25845 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
25846 Same as @code{disk-apm-bat} but on BAT mode.
25850 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
25851 Hard disk spin down timeout. One value has to be specified for each
25852 declared hard disk.
25854 Defaults to @samp{disabled}.
25858 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
25859 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
25861 Defaults to @samp{disabled}.
25865 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
25866 Select IO scheduler for disk devices. One value has to be specified for
25867 each declared hard disk. Example alternatives are cfq, deadline and
25870 Defaults to @samp{disabled}.
25874 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
25875 SATA aggressive link power management (ALPM) level. Alternatives are
25876 min_power, medium_power, max_performance.
25878 Defaults to @samp{"max_performance"}.
25882 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
25883 Same as @code{sata-linkpwr-ac} but on BAT mode.
25885 Defaults to @samp{"min_power"}.
25889 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
25890 Exclude specified SATA host devices for link power management.
25892 Defaults to @samp{disabled}.
25896 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
25897 Enable Runtime Power Management for AHCI controller and disks on AC
25900 Defaults to @samp{disabled}.
25904 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
25905 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
25907 Defaults to @samp{disabled}.
25911 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
25912 Seconds of inactivity before disk is suspended.
25914 Defaults to @samp{15}.
25918 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
25919 PCI Express Active State Power Management level. Alternatives are
25920 default, performance, powersave.
25922 Defaults to @samp{"performance"}.
25926 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
25927 Same as @code{pcie-aspm-ac} but on BAT mode.
25929 Defaults to @samp{"powersave"}.
25933 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
25934 Radeon graphics clock speed level. Alternatives are low, mid, high,
25937 Defaults to @samp{"high"}.
25941 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
25942 Same as @code{radeon-power-ac} but on BAT mode.
25944 Defaults to @samp{"low"}.
25948 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
25949 Radeon dynamic power management method (DPM). Alternatives are battery,
25952 Defaults to @samp{"performance"}.
25956 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
25957 Same as @code{radeon-dpm-state-ac} but on BAT mode.
25959 Defaults to @samp{"battery"}.
25963 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
25964 Radeon DPM performance level. Alternatives are auto, low, high.
25966 Defaults to @samp{"auto"}.
25970 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
25971 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
25973 Defaults to @samp{"auto"}.
25977 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
25978 Wifi power saving mode.
25980 Defaults to @samp{#f}.
25984 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
25985 Same as @code{wifi-power-ac?} but on BAT mode.
25987 Defaults to @samp{#t}.
25991 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
25992 Disable wake on LAN.
25994 Defaults to @samp{#t}.
25998 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
25999 Timeout duration in seconds before activating audio power saving on
26000 Intel HDA and AC97 devices. A value of 0 disables power saving.
26002 Defaults to @samp{0}.
26006 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
26007 Same as @code{sound-powersave-ac} but on BAT mode.
26009 Defaults to @samp{1}.
26013 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
26014 Disable controller in powersaving mode on Intel HDA devices.
26016 Defaults to @samp{#t}.
26020 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
26021 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
26022 powered on again by releasing (and reinserting) the eject lever or by
26023 pressing the disc eject button on newer models.
26025 Defaults to @samp{#f}.
26029 @deftypevr {@code{tlp-configuration} parameter} string bay-device
26030 Name of the optical drive device to power off.
26032 Defaults to @samp{"sr0"}.
26036 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
26037 Runtime Power Management for PCI(e) bus devices. Alternatives are on
26040 Defaults to @samp{"on"}.
26044 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
26045 Same as @code{runtime-pm-ac} but on BAT mode.
26047 Defaults to @samp{"auto"}.
26051 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
26052 Runtime Power Management for all PCI(e) bus devices, except blacklisted
26055 Defaults to @samp{#t}.
26059 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
26060 Exclude specified PCI(e) device addresses from Runtime Power Management.
26062 Defaults to @samp{disabled}.
26066 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
26067 Exclude PCI(e) devices assigned to the specified drivers from Runtime
26072 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
26073 Enable USB autosuspend feature.
26075 Defaults to @samp{#t}.
26079 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
26080 Exclude specified devices from USB autosuspend.
26082 Defaults to @samp{disabled}.
26086 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
26087 Exclude WWAN devices from USB autosuspend.
26089 Defaults to @samp{#t}.
26093 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
26094 Include specified devices into USB autosuspend, even if they are already
26095 excluded by the driver or via @code{usb-blacklist-wwan?}.
26097 Defaults to @samp{disabled}.
26101 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
26102 Enable USB autosuspend before shutdown.
26104 Defaults to @samp{disabled}.
26108 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
26109 Restore radio device state (bluetooth, wifi, wwan) from previous
26110 shutdown on system startup.
26112 Defaults to @samp{#f}.
26117 @cindex CPU frequency scaling with thermald
26118 @subsubheading Thermald daemon
26120 The @code{(gnu services pm)} module provides an interface to
26121 thermald, a CPU frequency scaling service which helps prevent overheating.
26123 @defvr {Scheme Variable} thermald-service-type
26124 This is the service type for
26125 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
26126 Thermal Daemon, which is responsible for controlling the thermal state
26127 of processors and preventing overheating.
26130 @deftp {Data Type} thermald-configuration
26131 Data type representing the configuration of @code{thermald-service-type}.
26134 @item @code{ignore-cpuid-check?} (default: @code{#f})
26135 Ignore cpuid check for supported CPU models.
26137 @item @code{thermald} (default: @var{thermald})
26138 Package object of thermald.
26143 @node Audio Services
26144 @subsection Audio Services
26146 The @code{(gnu services audio)} module provides a service to start MPD
26147 (the Music Player Daemon).
26150 @subsubheading Music Player Daemon
26152 The Music Player Daemon (MPD) is a service that can play music while
26153 being controlled from the local machine or over the network by a variety
26156 The following example shows how one might run @code{mpd} as user
26157 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
26160 (service mpd-service-type
26166 @defvr {Scheme Variable} mpd-service-type
26167 The service type for @command{mpd}
26170 @deftp {Data Type} mpd-configuration
26171 Data type representing the configuration of @command{mpd}.
26174 @item @code{user} (default: @code{"mpd"})
26175 The user to run mpd as.
26177 @item @code{music-dir} (default: @code{"~/Music"})
26178 The directory to scan for music files.
26180 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
26181 The directory to store playlists.
26183 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
26184 The location of the music database.
26186 @item @code{state-file} (default: @code{"~/.mpd/state"})
26187 The location of the file that stores current MPD's state.
26189 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
26190 The location of the sticker database.
26192 @item @code{port} (default: @code{"6600"})
26193 The port to run mpd on.
26195 @item @code{address} (default: @code{"any"})
26196 The address that mpd will bind to. To use a Unix domain socket,
26197 an absolute path can be specified here.
26199 @item @code{outputs} (default: @code{"(list (mpd-output))"})
26200 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
26205 @deftp {Data Type} mpd-output
26206 Data type representing an @command{mpd} audio output.
26209 @item @code{name} (default: @code{"MPD"})
26210 The name of the audio output.
26212 @item @code{type} (default: @code{"pulse"})
26213 The type of audio output.
26215 @item @code{enabled?} (default: @code{#t})
26216 Specifies whether this audio output is enabled when MPD is started. By
26217 default, all audio outputs are enabled. This is just the default
26218 setting when there is no state file; with a state file, the previous
26221 @item @code{tags?} (default: @code{#t})
26222 If set to @code{#f}, then MPD will not send tags to this output. This
26223 is only useful for output plugins that can receive tags, for example the
26224 @code{httpd} output plugin.
26226 @item @code{always-on?} (default: @code{#f})
26227 If set to @code{#t}, then MPD attempts to keep this audio output always
26228 open. This may be useful for streaming servers, when you don’t want to
26229 disconnect all listeners even when playback is accidentally stopped.
26231 @item @code{mixer-type}
26232 This field accepts a symbol that specifies which mixer should be used
26233 for this audio output: the @code{hardware} mixer, the @code{software}
26234 mixer, the @code{null} mixer (allows setting the volume, but with no
26235 effect; this can be used as a trick to implement an external mixer
26236 External Mixer) or no mixer (@code{none}).
26238 @item @code{extra-options} (default: @code{'()})
26239 An association list of option symbols to string values to be appended to
26240 the audio output configuration.
26245 The following example shows a configuration of @code{mpd} that provides
26246 an HTTP audio streaming output.
26249 (service mpd-service-type
26257 `((encoder . "vorbis")
26258 (port . "8080"))))))))
26262 @node Virtualization Services
26263 @subsection Virtualization Services
26265 The @code{(gnu services virtualization)} module provides services for
26266 the libvirt and virtlog daemons, as well as other virtualization-related
26269 @subsubheading Libvirt daemon
26271 @code{libvirtd} is the server side daemon component of the libvirt
26272 virtualization management system. This daemon runs on host servers
26273 and performs required management tasks for virtualized guests.
26275 @deffn {Scheme Variable} libvirt-service-type
26276 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
26277 Its value must be a @code{libvirt-configuration}.
26280 (service libvirt-service-type
26281 (libvirt-configuration
26282 (unix-sock-group "libvirt")
26283 (tls-port "16555")))
26287 @c Auto-generated with (generate-libvirt-documentation)
26288 Available @code{libvirt-configuration} fields are:
26290 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
26295 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
26296 Flag listening for secure TLS connections on the public TCP/IP port.
26297 You must set @code{listen} for this to have any effect.
26299 It is necessary to setup a CA and issue server certificates before using
26302 Defaults to @samp{#t}.
26306 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
26307 Listen for unencrypted TCP connections on the public TCP/IP port. You must
26308 set @code{listen} for this to have any effect.
26310 Using the TCP socket requires SASL authentication by default. Only SASL
26311 mechanisms which support data encryption are allowed. This is
26312 DIGEST_MD5 and GSSAPI (Kerberos5).
26314 Defaults to @samp{#f}.
26318 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
26319 Port for accepting secure TLS connections. This can be a port number,
26322 Defaults to @samp{"16514"}.
26326 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
26327 Port for accepting insecure TCP connections. This can be a port number,
26330 Defaults to @samp{"16509"}.
26334 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
26335 IP address or hostname used for client connections.
26337 Defaults to @samp{"0.0.0.0"}.
26341 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
26342 Flag toggling mDNS advertisement of the libvirt service.
26344 Alternatively can disable for all services on a host by stopping the
26347 Defaults to @samp{#f}.
26351 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
26352 Default mDNS advertisement name. This must be unique on the immediate
26355 Defaults to @samp{"Virtualization Host <hostname>"}.
26359 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
26360 UNIX domain socket group ownership. This can be used to allow a
26361 'trusted' set of users access to management capabilities without
26364 Defaults to @samp{"root"}.
26368 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
26369 UNIX socket permissions for the R/O socket. This is used for monitoring
26372 Defaults to @samp{"0777"}.
26376 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
26377 UNIX socket permissions for the R/W socket. Default allows only root.
26378 If PolicyKit is enabled on the socket, the default will change to allow
26379 everyone (eg, 0777)
26381 Defaults to @samp{"0770"}.
26385 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
26386 UNIX socket permissions for the admin socket. Default allows only owner
26387 (root), do not change it unless you are sure to whom you are exposing
26390 Defaults to @samp{"0777"}.
26394 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
26395 The directory in which sockets will be found/created.
26397 Defaults to @samp{"/var/run/libvirt"}.
26401 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
26402 Authentication scheme for UNIX read-only sockets. By default socket
26403 permissions allow anyone to connect
26405 Defaults to @samp{"polkit"}.
26409 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
26410 Authentication scheme for UNIX read-write sockets. By default socket
26411 permissions only allow root. If PolicyKit support was compiled into
26412 libvirt, the default will be to use 'polkit' auth.
26414 Defaults to @samp{"polkit"}.
26418 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
26419 Authentication scheme for TCP sockets. If you don't enable SASL, then
26420 all TCP traffic is cleartext. Don't do this outside of a dev/test
26423 Defaults to @samp{"sasl"}.
26427 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
26428 Authentication scheme for TLS sockets. TLS sockets already have
26429 encryption provided by the TLS layer, and limited authentication is done
26432 It is possible to make use of any SASL authentication mechanism as well,
26433 by using 'sasl' for this option
26435 Defaults to @samp{"none"}.
26439 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
26440 API access control scheme.
26442 By default an authenticated user is allowed access to all APIs. Access
26443 drivers can place restrictions on this.
26445 Defaults to @samp{()}.
26449 @deftypevr {@code{libvirt-configuration} parameter} string key-file
26450 Server key file path. If set to an empty string, then no private key is
26453 Defaults to @samp{""}.
26457 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
26458 Server key file path. If set to an empty string, then no certificate is
26461 Defaults to @samp{""}.
26465 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
26466 Server key file path. If set to an empty string, then no CA certificate
26469 Defaults to @samp{""}.
26473 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
26474 Certificate revocation list path. If set to an empty string, then no
26477 Defaults to @samp{""}.
26481 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
26482 Disable verification of our own server certificates.
26484 When libvirtd starts it performs some sanity checks against its own
26487 Defaults to @samp{#f}.
26491 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
26492 Disable verification of client certificates.
26494 Client certificate verification is the primary authentication mechanism.
26495 Any client which does not present a certificate signed by the CA will be
26498 Defaults to @samp{#f}.
26502 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
26503 Whitelist of allowed x509 Distinguished Name.
26505 Defaults to @samp{()}.
26509 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
26510 Whitelist of allowed SASL usernames. The format for username depends on
26511 the SASL authentication mechanism.
26513 Defaults to @samp{()}.
26517 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
26518 Override the compile time default TLS priority string. The default is
26519 usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
26520 is desired for libvirt to deviate from the global default settings.
26522 Defaults to @samp{"NORMAL"}.
26526 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
26527 Maximum number of concurrent client connections to allow over all
26530 Defaults to @samp{5000}.
26534 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
26535 Maximum length of queue of connections waiting to be accepted by the
26536 daemon. Note, that some protocols supporting retransmission may obey
26537 this so that a later reattempt at connection succeeds.
26539 Defaults to @samp{1000}.
26543 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
26544 Maximum length of queue of accepted but not yet authenticated clients.
26545 Set this to zero to turn this feature off
26547 Defaults to @samp{20}.
26551 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
26552 Number of workers to start up initially.
26554 Defaults to @samp{5}.
26558 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
26559 Maximum number of worker threads.
26561 If the number of active clients exceeds @code{min-workers}, then more
26562 threads are spawned, up to max_workers limit. Typically you'd want
26563 max_workers to equal maximum number of clients allowed.
26565 Defaults to @samp{20}.
26569 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
26570 Number of priority workers. If all workers from above pool are stuck,
26571 some calls marked as high priority (notably domainDestroy) can be
26572 executed in this pool.
26574 Defaults to @samp{5}.
26578 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
26579 Total global limit on concurrent RPC calls.
26581 Defaults to @samp{20}.
26585 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
26586 Limit on concurrent requests from a single client connection. To avoid
26587 one client monopolizing the server this should be a small fraction of
26588 the global max_requests and max_workers parameter.
26590 Defaults to @samp{5}.
26594 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
26595 Same as @code{min-workers} but for the admin interface.
26597 Defaults to @samp{1}.
26601 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
26602 Same as @code{max-workers} but for the admin interface.
26604 Defaults to @samp{5}.
26608 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
26609 Same as @code{max-clients} but for the admin interface.
26611 Defaults to @samp{5}.
26615 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
26616 Same as @code{max-queued-clients} but for the admin interface.
26618 Defaults to @samp{5}.
26622 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
26623 Same as @code{max-client-requests} but for the admin interface.
26625 Defaults to @samp{5}.
26629 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
26630 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
26632 Defaults to @samp{3}.
26636 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
26639 A filter allows to select a different logging level for a given category
26640 of logs. The format for a filter is one of:
26651 where @code{name} is a string which is matched against the category
26652 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
26653 file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
26654 name in the filter can be a substring of the full category name, in
26655 order to match multiple similar categories), the optional @samp{"+"}
26656 prefix tells libvirt to log stack trace for each message matching name,
26657 and @code{x} is the minimal level where matching messages should be
26675 Multiple filters can be defined in a single filters statement, they just
26676 need to be separated by spaces.
26678 Defaults to @samp{"3:remote 4:event"}.
26682 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
26685 An output is one of the places to save logging information. The format
26686 for an output can be:
26690 output goes to stderr
26692 @item x:syslog:name
26693 use syslog for the output and use the given name as the ident
26695 @item x:file:file_path
26696 output to a file, with the given filepath
26699 output to journald logging system
26703 In all case the x prefix is the minimal level, acting as a filter
26720 Multiple outputs can be defined, they just need to be separated by
26723 Defaults to @samp{"3:stderr"}.
26727 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
26728 Allows usage of the auditing subsystem to be altered
26732 0: disable all auditing
26735 1: enable auditing, only if enabled on host
26738 2: enable auditing, and exit if disabled on host.
26742 Defaults to @samp{1}.
26746 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
26747 Send audit messages via libvirt logging infrastructure.
26749 Defaults to @samp{#f}.
26753 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
26754 Host UUID. UUID must not have all digits be the same.
26756 Defaults to @samp{""}.
26760 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
26761 Source to read host UUID.
26765 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
26768 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
26772 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
26775 Defaults to @samp{"smbios"}.
26779 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
26780 A keepalive message is sent to a client after @code{keepalive_interval}
26781 seconds of inactivity to check if the client is still responding. If
26782 set to -1, libvirtd will never send keepalive requests; however clients
26783 can still send them and the daemon will send responses.
26785 Defaults to @samp{5}.
26789 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
26790 Maximum number of keepalive messages that are allowed to be sent to the
26791 client without getting any response before the connection is considered
26794 In other words, the connection is automatically closed approximately
26795 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
26796 the last message received from the client. When @code{keepalive-count}
26797 is set to 0, connections will be automatically closed after
26798 @code{keepalive-interval} seconds of inactivity without sending any
26799 keepalive messages.
26801 Defaults to @samp{5}.
26805 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
26806 Same as above but for admin interface.
26808 Defaults to @samp{5}.
26812 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
26813 Same as above but for admin interface.
26815 Defaults to @samp{5}.
26819 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
26820 Timeout for Open vSwitch calls.
26822 The @code{ovs-vsctl} utility is used for the configuration and its
26823 timeout option is set by default to 5 seconds to avoid potential
26824 infinite waits blocking libvirt.
26826 Defaults to @samp{5}.
26830 @c %end of autogenerated docs
26832 @subsubheading Virtlog daemon
26833 The virtlogd service is a server side daemon component of libvirt that is
26834 used to manage logs from virtual machine consoles.
26836 This daemon is not used directly by libvirt client applications, rather it
26837 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
26838 standalone daemon, the main @code{libvirtd} daemon can be restarted without
26839 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
26840 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
26842 @deffn {Scheme Variable} virtlog-service-type
26843 This is the type of the virtlog daemon.
26844 Its value must be a @code{virtlog-configuration}.
26847 (service virtlog-service-type
26848 (virtlog-configuration
26849 (max-clients 1000)))
26853 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
26854 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
26856 Defaults to @samp{3}.
26860 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
26863 A filter allows to select a different logging level for a given category
26864 of logs The format for a filter is one of:
26875 where @code{name} is a string which is matched against the category
26876 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
26877 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
26878 be a substring of the full category name, in order to match multiple
26879 similar categories), the optional "+" prefix tells libvirt to log stack
26880 trace for each message matching name, and @code{x} is the minimal level
26881 where matching messages should be logged:
26898 Multiple filters can be defined in a single filters statement, they just
26899 need to be separated by spaces.
26901 Defaults to @samp{"3:remote 4:event"}.
26905 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
26908 An output is one of the places to save logging information The format
26909 for an output can be:
26913 output goes to stderr
26915 @item x:syslog:name
26916 use syslog for the output and use the given name as the ident
26918 @item x:file:file_path
26919 output to a file, with the given filepath
26922 output to journald logging system
26926 In all case the x prefix is the minimal level, acting as a filter
26943 Multiple outputs can be defined, they just need to be separated by
26946 Defaults to @samp{"3:stderr"}.
26950 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
26951 Maximum number of concurrent client connections to allow over all
26954 Defaults to @samp{1024}.
26958 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
26959 Maximum file size before rolling over.
26961 Defaults to @samp{2MB}
26965 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
26966 Maximum number of backup files to keep.
26968 Defaults to @samp{3}
26972 @anchor{transparent-emulation-qemu}
26973 @subsubheading Transparent Emulation with QEMU
26976 @cindex @code{binfmt_misc}
26977 @code{qemu-binfmt-service-type} provides support for transparent
26978 emulation of program binaries built for different architectures---e.g.,
26979 it allows you to transparently execute an ARMv7 program on an x86_64
26980 machine. It achieves this by combining the @uref{https://www.qemu.org,
26981 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
26982 This feature only allows you to emulate GNU/Linux on a different
26983 architecture, but see below for GNU/Hurd support.
26985 @defvr {Scheme Variable} qemu-binfmt-service-type
26986 This is the type of the QEMU/binfmt service for transparent emulation.
26987 Its value must be a @code{qemu-binfmt-configuration} object, which
26988 specifies the QEMU package to use as well as the architecture we want to
26992 (service qemu-binfmt-service-type
26993 (qemu-binfmt-configuration
26994 (platforms (lookup-qemu-platforms "arm" "aarch64"))))
26997 In this example, we enable transparent emulation for the ARM and aarch64
26998 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
26999 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
27000 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
27003 @deftp {Data Type} qemu-binfmt-configuration
27004 This is the configuration for the @code{qemu-binfmt} service.
27007 @item @code{platforms} (default: @code{'()})
27008 The list of emulated QEMU platforms. Each item must be a @dfn{platform
27009 object} as returned by @code{lookup-qemu-platforms} (see below).
27011 @item @code{guix-support?} (default: @code{#f})
27012 When it is true, QEMU and all its dependencies are added to the build
27013 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
27014 @option{--chroot-directory} option}). This allows the @code{binfmt_misc}
27015 handlers to be used within the build environment, which in turn means
27016 that you can transparently build programs for another architecture.
27018 For example, let's suppose you're on an x86_64 machine and you have this
27022 (service qemu-binfmt-service-type
27023 (qemu-binfmt-configuration
27024 (platforms (lookup-qemu-platforms "arm"))
27025 (guix-support? #t)))
27031 guix build -s armhf-linux inkscape
27035 and it will build Inkscape for ARMv7 @emph{as if it were a native
27036 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
27037 if you'd like to test a package build for an architecture you don't have
27040 @item @code{qemu} (default: @code{qemu})
27041 The QEMU package to use.
27045 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
27046 Return the list of QEMU platform objects corresponding to
27047 @var{platforms}@dots{}. @var{platforms} must be a list of strings
27048 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
27049 @code{"mips64el"}, and so on.
27052 @deffn {Scheme Procedure} qemu-platform? @var{obj}
27053 Return true if @var{obj} is a platform object.
27056 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
27057 Return the name of @var{platform}---a string such as @code{"arm"}.
27061 @subsubheading The Hurd in a Virtual Machine
27063 @cindex @code{hurd}
27067 Service @code{hurd-vm} provides support for running GNU/Hurd in a
27068 virtual machine (VM), a so-called @dfn{childhurd}. This service is meant
27069 to be used on GNU/Linux and the given GNU/Hurd operating system
27070 configuration is cross-compiled. The virtual machine is a Shepherd
27071 service that can be referred to by the names @code{hurd-vm} and
27072 @code{childhurd} and be controlled with commands such as:
27076 herd stop childhurd
27079 When the service is running, you can view its console by connecting to
27080 it with a VNC client, for example with:
27083 guix environment --ad-hoc tigervnc-client -- \
27084 vncviewer localhost:5900
27087 The default configuration (see @code{hurd-vm-configuration} below)
27088 spawns a secure shell (SSH) server in your GNU/Hurd system, which QEMU
27089 (the virtual machine emulator) redirects to port 10222 on the host.
27090 Thus, you can connect over SSH to the childhurd with:
27093 ssh root@@localhost -p 10022
27096 The childhurd is volatile and stateless: it starts with a fresh root
27097 file system every time you restart it. By default though, all the files
27098 under @file{/etc/childhurd} on the host are copied as is to the root
27099 file system of the childhurd when it boots. This allows you to
27100 initialize ``secrets'' inside the VM: SSH host keys, authorized
27101 substitute keys, and so on---see the explanation of @code{secret-root}
27104 @defvr {Scheme Variable} hurd-vm-service-type
27105 This is the type of the Hurd in a Virtual Machine service. Its value
27106 must be a @code{hurd-vm-configuration} object, which specifies the
27107 operating system (@pxref{operating-system Reference}) and the disk size
27108 for the Hurd Virtual Machine, the QEMU package to use as well as the
27109 options for running it.
27114 (service hurd-vm-service-type
27115 (hurd-vm-configuration
27116 (disk-size (* 5000 (expt 2 20))) ;5G
27117 (memory-size 1024))) ;1024MiB
27120 would create a disk image big enough to build GNU@tie{}Hello, with some
27124 @deftp {Data Type} hurd-vm-configuration
27125 The data type representing the configuration for
27126 @code{hurd-vm-service-type}.
27129 @item @code{os} (default: @var{%hurd-vm-operating-system})
27130 The operating system to instantiate. This default is bare-bones with a
27131 permissive OpenSSH secure shell daemon listening on port 2222
27132 (@pxref{Networking Services, @code{openssh-service-type}}).
27134 @item @code{qemu} (default: @code{qemu-minimal})
27135 The QEMU package to use.
27137 @item @code{image} (default: @var{hurd-vm-disk-image})
27138 The procedure used to build the disk-image built from this
27141 @item @code{disk-size} (default: @code{'guess})
27142 The size of the disk image.
27144 @item @code{memory-size} (default: @code{512})
27145 The memory size of the Virtual Machine in mebibytes.
27147 @item @code{options} (default: @code{'("--snapshot")})
27148 The extra options for running QEMU.
27150 @item @code{id} (default: @code{#f})
27151 If set, a non-zero positive integer used to parameterize Childhurd
27152 instances. It is appended to the service's name,
27153 e.g. @code{childhurd1}.
27155 @item @code{net-options} (default: @var{hurd-vm-net-options})
27156 The procedure used to produce the list of QEMU networking options.
27158 By default, it produces
27161 '("--device" "rtl8139,netdev=net0"
27162 "--netdev" "user,id=net0\
27163 ,hostfwd=tcp:127.0.0.1:@var{secrets-port}-:1004\
27164 ,hostfwd=tcp:127.0.0.1:@var{ssh-port}-:2222\
27165 ,hostfwd=tcp:127.0.0.1:@var{vnc-port}-:5900")
27168 with forwarded ports:
27171 @var{secrets-port}: @code{(+ 11004 (* 1000 @var{ID}))}
27172 @var{ssh-port}: @code{(+ 10022 (* 1000 @var{ID}))}
27173 @var{vnc-port}: @code{(+ 15900 (* 1000 @var{ID}))}
27176 @item @code{secret-root} (default: @file{/etc/childhurd})
27177 The root directory with out-of-band secrets to be installed into the
27178 childhurd once it runs. Childhurds are volatile which means that on
27179 every startup, secrets such as the SSH host keys and Guix signing key
27182 If the @file{/etc/childhurd} directory does not exist, the
27183 @code{secret-service} running in the Childhurd will be sent an empty
27186 By default, the service automatically populates @file{/etc/childhurd}
27187 with the following non-volatile secrets, unless they already exist:
27190 /etc/childhurd/etc/guix/acl
27191 /etc/childhurd/etc/guix/signing-key.pub
27192 /etc/childhurd/etc/guix/signing-key.sec
27193 /etc/childhurd/etc/ssh/ssh_host_ed25519_key
27194 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key
27195 /etc/childhurd/etc/ssh/ssh_host_ed25519_key.pub
27196 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key.pub
27199 These files are automatically sent to the guest Hurd VM when it boots,
27200 including permissions.
27202 @cindex childhurd, offloading
27203 @cindex Hurd, offloading
27204 Having these files in place means that only a couple of things are
27205 missing to allow the host to offload @code{i586-gnu} builds to the
27210 Authorizing the childhurd's key on the host so that the host accepts
27211 build results coming from the childhurd, which can be done like so:
27214 guix archive --authorize < \
27215 /etc/childhurd/etc/guix/signing-key.pub
27219 Adding the childhurd to @file{/etc/guix/machines.scm} (@pxref{Daemon
27223 We're working towards making that happen automatically---get in touch
27224 with us at @email{guix-devel@@gnu.org} to discuss it!
27228 Note that by default the VM image is volatile, i.e., once stopped the
27229 contents are lost. If you want a stateful image instead, override the
27230 configuration's @code{image} and @code{options} without
27231 the @code{--snapshot} flag using something along these lines:
27234 (service hurd-vm-service-type
27235 (hurd-vm-configuration
27236 (image (const "/out/of/store/writable/hurd.img"))
27240 @subsubheading Ganeti
27245 This service is considered experimental. Configuration options may be changed
27246 in a backwards-incompatible manner, and not all features have been thorougly
27247 tested. Users of this service are encouraged to share their experience at
27248 @email{guix-devel@@gnu.org}.
27251 Ganeti is a virtual machine management system. It is designed to keep virtual
27252 machines running on a cluster of servers even in the event of hardware failures,
27253 and to make maintenance and recovery tasks easy. It consists of multiple
27254 services which are described later in this section. In addition to the Ganeti
27255 service, you will need the OpenSSH service (@pxref{Networking Services,
27256 @code{openssh-service-type}}), and update the @file{/etc/hosts} file
27257 (@pxref{operating-system Reference, @code{hosts-file}}) with the cluster name
27258 and address (or use a DNS server).
27260 All nodes participating in a Ganeti cluster should have the same Ganeti and
27261 @file{/etc/hosts} configuration. Here is an example configuration for a Ganeti
27262 cluster node that supports multiple storage backends, and installs the
27263 @code{debootstrap} and @code{guix} @dfn{OS providers}:
27266 (use-package-modules virtualization)
27267 (use-service-modules base ganeti networking ssh)
27270 (host-name "node1")
27271 (hosts-file (plain-file "hosts" (format #f "
27272 127.0.0.1 localhost
27275 192.168.1.200 ganeti.example.com
27276 192.168.1.201 node1.example.com node1
27277 192.168.1.202 node2.example.com node2
27280 ;; Install QEMU so we can use KVM-based instances, and LVM, DRBD and Ceph
27281 ;; in order to use the "plain", "drbd" and "rbd" storage backends.
27282 (packages (append (map specification->package
27283 '("qemu" "lvm2" "drbd-utils" "ceph"
27284 ;; Add the debootstrap and guix OS providers.
27285 "ganeti-instance-guix" "ganeti-instance-debootstrap"))
27288 (append (list (static-networking-service "eth0" "192.168.1.201"
27289 #:netmask "255.255.255.0"
27290 #:gateway "192.168.1.254"
27291 #:name-servers '("192.168.1.252"
27294 ;; Ganeti uses SSH to communicate between nodes.
27295 (service openssh-service-type
27296 (openssh-configuration
27297 (permit-root-login 'without-password)))
27299 (service ganeti-service-type
27300 (ganeti-configuration
27301 ;; This list specifies allowed file system paths
27302 ;; for storing virtual machine images.
27303 (file-storage-paths '("/srv/ganeti/file-storage"))
27304 ;; This variable configures a single "variant" for
27305 ;; both Debootstrap and Guix that works with KVM.
27306 (os %default-ganeti-os))))
27310 Users are advised to read the
27311 @url{http://docs.ganeti.org/ganeti/master/html/admin.html,Ganeti
27312 administrators guide} to learn about the various cluster options and
27313 day-to-day operations. There is also a
27314 @url{https://guix.gnu.org/blog/2020/running-a-ganeti-cluster-on-guix/,blog post}
27315 describing how to configure and initialize a small cluster.
27317 @defvr {Scheme Variable} ganeti-service-type
27318 This is a service type that includes all the various services that Ganeti
27321 Its value is a @code{ganeti-configuration} object that defines the package
27322 to use for CLI operations, as well as configuration for the various daemons.
27323 Allowed file storage paths and available guest operating systems are also
27324 configured through this data type.
27327 @deftp {Data Type} ganeti-configuration
27328 The @code{ganeti} service takes the following configuration options:
27331 @item @code{ganeti} (default: @code{ganeti})
27332 The @code{ganeti} package to use. It will be installed to the system profile
27333 and make @command{gnt-cluster}, @command{gnt-instance}, etc available. Note
27334 that the value specified here does not affect the other services as each refer
27335 to a specific @code{ganeti} package (see below).
27337 @item @code{noded-configuration} (default: @code{(ganeti-noded-configuration)})
27338 @itemx @code{confd-configuration} (default: @code{(ganeti-confd-configuration)})
27339 @itemx @code{wconfd-configuration} (default: @code{(ganeti-wconfd-configuration)})
27340 @itemx @code{luxid-configuration} (default: @code{(ganeti-luxid-configuration)})
27341 @itemx @code{rapi-configuration} (default: @code{(ganeti-rapi-configuration)})
27342 @itemx @code{kvmd-configuration} (default: @code{(ganeti-kvmd-configuration)})
27343 @itemx @code{mond-configuration} (default: @code{(ganeti-mond-configuration)})
27344 @itemx @code{metad-configuration} (default: @code{(ganeti-metad-configuration)})
27345 @itemx @code{watcher-configuration} (default: @code{(ganeti-watcher-configuration)})
27346 @itemx @code{cleaner-configuration} (default: @code{(ganeti-cleaner-configuration)})
27348 These options control the various daemons and cron jobs that are distributed
27349 with Ganeti. The possible values for these are described in detail below.
27350 To override a setting, you must use the configuration type for that service:
27353 (service ganeti-service-type
27354 (ganeti-configuration
27355 (rapi-configuration
27356 (ganeti-rapi-configuration
27357 (interface "eth1"))))
27358 (watcher-configuration
27359 (ganeti-watcher-configuration
27360 (rapi-ip "10.0.0.1"))))
27363 @item @code{file-storage-paths} (default: @code{'()})
27364 List of allowed directories for file storage backend.
27366 @item @code{os} (default: @code{%default-ganeti-os})
27367 List of @code{<ganeti-os>} records.
27370 In essence @code{ganeti-service-type} is shorthand for declaring each service
27374 (service ganeti-noded-service-type)
27375 (service ganeti-confd-service-type)
27376 (service ganeti-wconfd-service-type)
27377 (service ganeti-luxid-service-type)
27378 (service ganeti-kvmd-service-type)
27379 (service ganeti-mond-service-type)
27380 (service ganeti-metad-service-type)
27381 (service ganeti-watcher-service-type)
27382 (service ganeti-cleaner-service-type)
27385 Plus a service extension for @code{etc-service-type} that configures the file
27386 storage backend and OS variants.
27390 @deftp {Data Type} ganeti-os
27391 This data type is suitable for passing to the @code{os} parameter of
27392 @code{ganeti-configuration}. It takes the following parameters:
27396 The name for this OS provider. It is only used to specify where the
27397 configuration ends up. Setting it to ``debootstrap'' will create
27398 @file{/etc/ganeti/instance-debootstrap}.
27400 @item @code{extension}
27401 The file extension for variants of this OS type. For example
27402 @file{.conf} or @file{.scm}.
27404 @item @code{variants} (default: @code{'()})
27405 List of @code{ganeti-os-variant} objects for this OS.
27410 @deftp {Data Type} ganeti-os-variant
27411 This is the data type for a Ganeti OS variant. It takes the following
27416 The name of this variant.
27418 @item @code{configuration}
27419 A configuration file for this variant.
27423 @defvr {Scheme Variable} %default-debootstrap-hooks
27424 This variable contains hooks to configure networking and the GRUB bootloader.
27427 @defvr {Scheme Variable} %default-debootstrap-extra-pkgs
27428 This variable contains a list of packages suitable for a fully-virtualized guest.
27431 @deftp {Data Type} debootstrap-configuration
27433 This data type creates configuration files suitable for the debootstrap OS provider.
27436 @item @code{hooks} (default: @code{%default-debootstrap-hooks})
27437 When not @code{#f}, this must be a G-expression that specifies a directory with
27438 scripts that will run when the OS is installed. It can also be a list of
27439 @code{(name . file-like)} pairs. For example:
27442 `((99-hello-world . ,(plain-file "#!/bin/sh\necho Hello, World")))
27445 That will create a directory with one executable named @code{99-hello-world}
27446 and run it every time this variant is installed. If set to @code{#f}, hooks
27447 in @file{/etc/ganeti/instance-debootstrap/hooks} will be used, if any.
27448 @item @code{proxy} (default: @code{#f})
27449 Optional HTTP proxy to use.
27450 @item @code{mirror} (default: @code{#f})
27451 The Debian mirror. Typically something like @code{http://ftp.no.debian.org/debian}.
27452 The default varies depending on the distribution.
27453 @item @code{arch} (default: @code{#f})
27454 The dpkg architecture. Set to @code{armhf} to debootstrap an ARMv7 instance
27455 on an AArch64 host. Default is to use the current system architecture.
27456 @item @code{suite} (default: @code{"stable"})
27457 When set, this must be a Debian distribution ``suite'' such as @code{buster}
27458 or @code{focal}. If set to @code{#f}, the default for the OS provider is used.
27459 @item @code{extra-pkgs} (default: @code{%default-debootstrap-extra-pkgs})
27460 List of extra packages that will get installed by dpkg in addition
27461 to the minimal system.
27462 @item @code{components} (default: @code{#f})
27463 When set, must be a list of Debian repository ``components''. For example
27464 @code{'("main" "contrib")}.
27465 @item @code{generate-cache?} (default: @code{#t})
27466 Whether to automatically cache the generated debootstrap archive.
27467 @item @code{clean-cache} (default: @code{14})
27468 Discard the cache after this amount of days. Use @code{#f} to never
27470 @item @code{partition-style} (default: @code{'msdos})
27471 The type of partition to create. When set, it must be one of
27472 @code{'msdos}, @code{'none} or a string.
27473 @item @code{partition-alignment} (default: @code{2048})
27474 Alignment of the partition in sectors.
27478 @deffn {Scheme Procedure} debootstrap-variant @var{name} @var{configuration}
27479 This is a helper procedure that creates a @code{ganeti-os-variant} record. It
27480 takes two parameters: a name and a @code{debootstrap-configuration} object.
27483 @deffn {Scheme Procedure} debootstrap-os @var{variants}@dots{}
27484 This is a helper procedure that creates a @code{ganeti-os} record. It takes
27485 a list of variants created with @code{debootstrap-variant}.
27488 @deffn {Scheme Procedure} guix-variant @var{name} @var{configuration}
27489 This is a helper procedure that creates a @code{ganeti-os-variant} record for
27490 use with the Guix OS provider. It takes a name and a G-expression that returns
27491 a ``file-like'' (@pxref{G-Expressions, file-like objects}) object containing a
27492 Guix System configuration.
27495 @deffn {Scheme Procedure} guix-os @var{variants}@dots{}
27496 This is a helper procedure that creates a @code{ganeti-os} record. It
27497 takes a list of variants produced by @code{guix-variant}.
27500 @defvr {Scheme Variable} %default-debootstrap-variants
27501 This is a convenience variable to make the debootstrap provider work
27502 ``out of the box'' without users having to declare variants manually. It
27503 contains a single debootstrap variant with the default configuration:
27506 (list (debootstrap-variant
27508 (debootstrap-configuration)))
27512 @defvr {Scheme Variable} %default-guix-variants
27513 This is a convenience variable to make the Guix OS provider work without
27514 additional configuration. It creates a virtual machine that has an SSH
27515 server, a serial console, and authorizes the Ganeti hosts SSH keys.
27518 (list (guix-variant
27520 (file-append ganeti-instance-guix
27521 "/share/doc/ganeti-instance-guix/examples/dynamic.scm")))
27525 Users can implement support for OS providers unbeknownst to Guix by extending
27526 the @code{ganeti-os} and @code{ganeti-os-variant} records appropriately.
27532 (extension ".conf")
27534 (list (ganeti-os-variant
27536 (configuration (plain-file "bar" "this is fine"))))))
27539 That creates @file{/etc/ganeti/instance-custom/variants/foo.conf} which points
27540 to a file in the store with contents @code{this is fine}. It also creates
27541 @file{/etc/ganeti/instance-custom/variants/variants.list} with contents @code{foo}.
27543 Obviously this may not work for all OS providers out there. If you find the
27544 interface limiting, please reach out to @email{guix-devel@@gnu.org}.
27546 The rest of this section documents the various services that are included by
27547 @code{ganeti-service-type}.
27549 @defvr {Scheme Variable} ganeti-noded-service-type
27550 @command{ganeti-noded} is the daemon responsible for node-specific functions
27551 within the Ganeti system. The value of this service must be a
27552 @code{ganeti-noded-configuration} object.
27555 @deftp {Data Type} ganeti-noded-configuration
27556 This is the configuration for the @code{ganeti-noded} service.
27559 @item @code{ganeti} (default: @code{ganeti})
27560 The @code{ganeti} package to use for this service.
27562 @item @code{port} (default: @code{1811})
27563 The TCP port on which the node daemon listens for network requests.
27565 @item @code{address} (default: @code{"0.0.0.0"})
27566 The network address that the daemon will bind to. The default address means
27567 bind to all available addresses.
27569 @item @code{interface} (default: @code{#f})
27570 When this is set, it must be a specific network interface (e.g.@: @code{eth0})
27571 that the daemon will bind to.
27573 @item @code{max-clients} (default: @code{20})
27574 This sets a limit on the maximum number of simultaneous client connections
27575 that the daemon will handle. Connections above this count are accepted, but
27576 no responses will be sent until enough connections have closed.
27578 @item @code{ssl?} (default: @code{#t})
27579 Whether to use SSL/TLS to encrypt network communications. The certificate
27580 is automatically provisioned by the cluster and can be rotated with
27581 @command{gnt-cluster renew-crypto}.
27583 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
27584 This can be used to provide a specific encryption key for TLS communications.
27586 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
27587 This can be used to provide a specific certificate for TLS communications.
27589 @item @code{debug?} (default: @code{#f})
27590 When true, the daemon performs additional logging for debugging purposes.
27591 Note that this will leak encryption details to the log files, use with caution.
27596 @defvr {Scheme Variable} ganeti-confd-service-type
27597 @command{ganeti-confd} answers queries related to the configuration of a
27598 Ganeti cluster. The purpose of this daemon is to have a highly available
27599 and fast way to query cluster configuration values. It is automatically
27600 active on all @dfn{master candidates}. The value of this service must be a
27601 @code{ganeti-confd-configuration} object.
27605 @deftp {Data Type} ganeti-confd-configuration
27606 This is the configuration for the @code{ganeti-confd} service.
27609 @item @code{ganeti} (default: @code{ganeti})
27610 The @code{ganeti} package to use for this service.
27612 @item @code{port} (default: @code{1814})
27613 The UDP port on which to listen for network requests.
27615 @item @code{address} (default: @code{"0.0.0.0"})
27616 Network address that the daemon will bind to.
27618 @item @code{debug?} (default: @code{#f})
27619 When true, the daemon performs additional logging for debugging purposes.
27624 @defvr {Scheme Variable} ganeti-wconfd-service-type
27625 @command{ganeti-wconfd} is the daemon that has authoritative knowledge
27626 about the cluster configuration and is the only entity that can accept
27627 changes to it. All jobs that need to modify the configuration will do so
27628 by sending appropriate requests to this daemon. It only runs on the
27629 @dfn{master node} and will automatically disable itself on other nodes.
27631 The value of this service must be a
27632 @code{ganeti-wconfd-configuration} object.
27635 @deftp {Data Type} ganeti-wconfd-configuration
27636 This is the configuration for the @code{ganeti-wconfd} service.
27639 @item @code{ganeti} (default: @code{ganeti})
27640 The @code{ganeti} package to use for this service.
27642 @item @code{no-voting?} (default: @code{#f})
27643 The daemon will refuse to start if the majority of cluster nodes does not
27644 agree that it is running on the master node. Set to @code{#t} to start
27645 even if a quorum can not be reached (dangerous, use with caution).
27647 @item @code{debug?} (default: @code{#f})
27648 When true, the daemon performs additional logging for debugging purposes.
27653 @defvr {Scheme Variable} ganeti-luxid-service-type
27654 @command{ganeti-luxid} is a daemon used to answer queries related to the
27655 configuration and the current live state of a Ganeti cluster. Additionally,
27656 it is the authoritative daemon for the Ganeti job queue. Jobs can be
27657 submitted via this daemon and it schedules and starts them.
27659 It takes a @code{ganeti-luxid-configuration} object.
27662 @deftp {Data Type} ganeti-luxid-configuration
27663 This is the configuration for the @code{ganeti-wconfd} service.
27666 @item @code{ganeti} (default: @code{ganeti})
27667 The @code{ganeti} package to use for this service.
27669 @item @code{no-voting?} (default: @code{#f})
27670 The daemon will refuse to start if it cannot verify that the majority of
27671 cluster nodes believes that it is running on the master node. Set to
27672 @code{#t} to ignore such checks and start anyway (this can be dangerous).
27674 @item @code{debug?} (default: @code{#f})
27675 When true, the daemon performs additional logging for debugging purposes.
27680 @defvr {Scheme Variable} ganeti-rapi-service-type
27681 @command{ganeti-rapi} provides a remote API for Ganeti clusters. It runs on
27682 the master node and can be used to perform cluster actions programmatically
27683 via a JSON-based RPC protocol.
27685 Most query operations are allowed without authentication (unless
27686 @var{require-authentication?} is set), whereas write operations require
27687 explicit authorization via the @file{/var/lib/ganeti/rapi/users} file. See
27688 the @url{http://docs.ganeti.org/ganeti/master/html/rapi.html, Ganeti Remote
27689 API documentation} for more information.
27691 The value of this service must be a @code{ganeti-rapi-configuration} object.
27694 @deftp {Data Type} ganeti-rapi-configuration
27695 This is the configuration for the @code{ganeti-rapi} service.
27698 @item @code{ganeti} (default: @code{ganeti})
27699 The @code{ganeti} package to use for this service.
27701 @item @code{require-authentication?} (default: @code{#f})
27702 Whether to require authentication even for read-only operations.
27704 @item @code{port} (default: @code{5080})
27705 The TCP port on which to listen to API requests.
27707 @item @code{address} (default: @code{"0.0.0.0"})
27708 The network address that the service will bind to. By default it listens
27709 on all configured addresses.
27711 @item @code{interface} (default: @code{#f})
27712 When set, it must specify a specific network interface such as @code{eth0}
27713 that the daemon will bind to.
27715 @item @code{max-clients} (default: @code{20})
27716 The maximum number of simultaneous client requests to handle. Further
27717 connections are allowed, but no responses are sent until enough connections
27720 @item @code{ssl?} (default: @code{#t})
27721 Whether to use SSL/TLS encryption on the RAPI port.
27723 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
27724 This can be used to provide a specific encryption key for TLS communications.
27726 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
27727 This can be used to provide a specific certificate for TLS communications.
27729 @item @code{debug?} (default: @code{#f})
27730 When true, the daemon performs additional logging for debugging purposes.
27731 Note that this will leak encryption details to the log files, use with caution.
27736 @defvr {Scheme Variable} ganeti-kvmd-service-type
27737 @command{ganeti-kvmd} is responsible for determining whether a given KVM
27738 instance was shut down by an administrator or a user. Normally Ganeti will
27739 restart an instance that was not stopped through Ganeti itself. If the
27740 cluster option @code{user_shutdown} is true, this daemon monitors the
27741 @code{QMP} socket provided by QEMU and listens for shutdown events, and
27742 marks the instance as @dfn{USER_down} instead of @dfn{ERROR_down} when
27743 it shuts down gracefully by itself.
27745 It takes a @code{ganeti-kvmd-configuration} object.
27748 @deftp {Data Type} ganeti-kvmd-configuration
27751 @item @code{ganeti} (default: @code{ganeti})
27752 The @code{ganeti} package to use for this service.
27754 @item @code{debug?} (default: @code{#f})
27755 When true, the daemon performs additional logging for debugging purposes.
27760 @defvr {Scheme Variable} ganeti-mond-service-type
27761 @command{ganeti-mond} is an optional daemon that provides Ganeti monitoring
27762 functionality. It is responsible for running data collectors and publish the
27763 collected information through a HTTP interface.
27765 It takes a @code{ganeti-mond-configuration} object.
27768 @deftp {Data Type} ganeti-mond-configuration
27771 @item @code{ganeti} (default: @code{ganeti})
27772 The @code{ganeti} package to use for this service.
27774 @item @code{port} (default: @code{1815})
27775 The port on which the daemon will listen.
27777 @item @code{address} (default: @code{"0.0.0.0"})
27778 The network address that the daemon will bind to. By default it binds to all
27779 available interfaces.
27781 @item @code{debug?} (default: @code{#f})
27782 When true, the daemon performs additional logging for debugging purposes.
27787 @defvr {Scheme Variable} ganeti-metad-service-type
27788 @command{ganeti-metad} is an optional daemon that can be used to provide
27789 information about the cluster to instances or OS install scripts.
27791 It takes a @code{ganeti-metad-configuration} object.
27794 @deftp {Data Type} ganeti-metad-configuration
27797 @item @code{ganeti} (default: @code{ganeti})
27798 The @code{ganeti} package to use for this service.
27800 @item @code{port} (default: @code{80})
27801 The port on which the daemon will listen.
27803 @item @code{address} (default: @code{#f})
27804 If set, the daemon will bind to this address only. If left unset, the behavior
27805 depends on the cluster configuration.
27807 @item @code{debug?} (default: @code{#f})
27808 When true, the daemon performs additional logging for debugging purposes.
27813 @defvr {Scheme Variable} ganeti-watcher-service-type
27814 @command{ganeti-watcher} is a script designed to run periodically and ensure
27815 the health of a cluster. It will automatically restart instances that have
27816 stopped without Ganeti's consent, and repairs DRBD links in case a node has
27817 rebooted. It also archives old cluster jobs and restarts Ganeti daemons
27818 that are not running. If the cluster parameter @code{ensure_node_health}
27819 is set, the watcher will also shutdown instances and DRBD devices if the
27820 node it is running on is declared offline by known master candidates.
27822 It can be paused on all nodes with @command{gnt-cluster watcher pause}.
27824 The service takes a @code{ganeti-watcher-configuration} object.
27827 @deftp {Data Type} ganeti-watcher-configuration
27830 @item @code{ganeti} (default: @code{ganeti})
27831 The @code{ganeti} package to use for this service.
27833 @item @code{schedule} (default: @code{'(next-second-from (next-minute (range 0 60 5)))})
27834 How often to run the script. The default is every five minutes.
27836 @item @code{rapi-ip} (default: @code{#f})
27837 This option needs to be specified only if the RAPI daemon is configured to use
27838 a particular interface or address. By default the cluster address is used.
27840 @item @code{job-age} (default: @code{(* 6 3600)})
27841 Archive cluster jobs older than this age, specified in seconds. The default
27842 is 6 hours. This keeps @command{gnt-job list} manageable.
27844 @item @code{verify-disks?} (default: @code{#t})
27845 If this is @code{#f}, the watcher will not try to repair broken DRBD links
27846 automatically. Administrators will need to use @command{gnt-cluster verify-disks}
27849 @item @code{debug?} (default: @code{#f})
27850 When @code{#t}, the script performs additional logging for debugging purposes.
27855 @defvr {Scheme Variable} ganeti-cleaner-service-type
27856 @command{ganeti-cleaner} is a script designed to run periodically and remove
27857 old files from the cluster. This service type controls two @dfn{cron jobs}:
27858 one intended for the master node that permanently purges old cluster jobs,
27859 and one intended for every node that removes expired X509 certificates, keys,
27860 and outdated @command{ganeti-watcher} information. Like all Ganeti services,
27861 it is safe to include even on non-master nodes as it will disable itself as
27864 It takes a @code{ganeti-cleaner-configuration} object.
27867 @deftp {Data Type} ganeti-cleaner-configuration
27870 @item @code{ganeti} (default: @code{ganeti})
27871 The @code{ganeti} package to use for the @command{gnt-cleaner} command.
27873 @item @code{master-schedule} (default: @code{"45 1 * * *"})
27874 How often to run the master cleaning job. The default is once per day, at
27877 @item @code{node-schedule} (default: @code{"45 2 * * *"})
27878 How often to run the node cleaning job. The default is once per day, at
27884 @node Version Control Services
27885 @subsection Version Control Services
27887 The @code{(gnu services version-control)} module provides a service to
27888 allow remote access to local Git repositories. There are three options:
27889 the @code{git-daemon-service}, which provides access to repositories via
27890 the @code{git://} unsecured TCP-based protocol, extending the
27891 @code{nginx} web server to proxy some requests to
27892 @code{git-http-backend}, or providing a web interface with
27893 @code{cgit-service-type}.
27895 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
27897 Return a service that runs @command{git daemon}, a simple TCP server to
27898 expose repositories over the Git protocol for anonymous access.
27900 The optional @var{config} argument should be a
27901 @code{<git-daemon-configuration>} object, by default it allows read-only
27902 access to exported@footnote{By creating the magic file
27903 @file{git-daemon-export-ok} in the repository directory.} repositories under
27908 @deftp {Data Type} git-daemon-configuration
27909 Data type representing the configuration for @code{git-daemon-service}.
27912 @item @code{package} (default: @code{git})
27913 Package object of the Git distributed version control system.
27915 @item @code{export-all?} (default: @code{#f})
27916 Whether to allow access for all Git repositories, even if they do not
27917 have the @file{git-daemon-export-ok} file.
27919 @item @code{base-path} (default: @file{/srv/git})
27920 Whether to remap all the path requests as relative to the given path.
27921 If you run @command{git daemon} with @code{(base-path "/srv/git")} on
27922 @samp{example.com}, then if you later try to pull
27923 @indicateurl{git://example.com/hello.git}, git daemon will interpret the
27924 path as @file{/srv/git/hello.git}.
27926 @item @code{user-path} (default: @code{#f})
27927 Whether to allow @code{~user} notation to be used in requests. When
27928 specified with empty string, requests to
27929 @indicateurl{git://host/~alice/foo} is taken as a request to access
27930 @code{foo} repository in the home directory of user @code{alice}. If
27931 @code{(user-path "@var{path}")} is specified, the same request is taken
27932 as a request to access @file{@var{path}/foo} repository in the home
27933 directory of user @code{alice}.
27935 @item @code{listen} (default: @code{'()})
27936 Whether to listen on specific IP addresses or hostnames, defaults to
27939 @item @code{port} (default: @code{#f})
27940 Whether to listen on an alternative port, which defaults to 9418.
27942 @item @code{whitelist} (default: @code{'()})
27943 If not empty, only allow access to this list of directories.
27945 @item @code{extra-options} (default: @code{'()})
27946 Extra options will be passed to @command{git daemon}, please run
27947 @command{man git-daemon} for more information.
27952 The @code{git://} protocol lacks authentication. When you pull from a
27953 repository fetched via @code{git://}, you don't know whether the data you
27954 receive was modified or is even coming from the specified host, and your
27955 connection is subject to eavesdropping. It's better to use an authenticated
27956 and encrypted transport, such as @code{https}. Although Git allows you
27957 to serve repositories using unsophisticated file-based web servers,
27958 there is a faster protocol implemented by the @code{git-http-backend}
27959 program. This program is the back-end of a proper Git web service. It
27960 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
27961 on running the necessary @code{fcgiwrap} daemon.
27963 Guix has a separate configuration data type for serving Git repositories
27966 @deftp {Data Type} git-http-configuration
27967 Data type representing the configuration for a future
27968 @code{git-http-service-type}; can currently be used to configure Nginx
27969 through @code{git-http-nginx-location-configuration}.
27972 @item @code{package} (default: @var{git})
27973 Package object of the Git distributed version control system.
27975 @item @code{git-root} (default: @file{/srv/git})
27976 Directory containing the Git repositories to expose to the world.
27978 @item @code{export-all?} (default: @code{#f})
27979 Whether to expose access for all Git repositories in @var{git-root},
27980 even if they do not have the @file{git-daemon-export-ok} file.
27982 @item @code{uri-path} (default: @samp{/git/})
27983 Path prefix for Git access. With the default @samp{/git/} prefix, this
27984 will map @indicateurl{http://@var{server}/git/@var{repo}.git} to
27985 @file{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
27986 with this prefix are not passed on to this Git instance.
27988 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
27989 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
27994 There is no @code{git-http-service-type}, currently; instead you can
27995 create an @code{nginx-location-configuration} from a
27996 @code{git-http-configuration} and then add that location to a web
27999 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
28000 [config=(git-http-configuration)]
28001 Compute an @code{nginx-location-configuration} that corresponds to the
28002 given Git http configuration. An example nginx service definition to
28003 serve the default @file{/srv/git} over HTTPS might be:
28006 (service nginx-service-type
28007 (nginx-configuration
28010 (nginx-server-configuration
28011 (listen '("443 ssl"))
28012 (server-name "git.my-host.org")
28014 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
28015 (ssl-certificate-key
28016 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
28019 (git-http-nginx-location-configuration
28020 (git-http-configuration (uri-path "/"))))))))))
28023 This example assumes that you are using Let's Encrypt to get your TLS
28024 certificate. @xref{Certificate Services}. The default @code{certbot}
28025 service will redirect all HTTP traffic on @code{git.my-host.org} to
28026 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
28027 system services. @xref{Web Services}.
28030 @subsubheading Cgit Service
28032 @cindex Cgit service
28033 @cindex Git, web interface
28034 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
28035 repositories written in C.
28037 The following example will configure the service with default values.
28038 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
28041 (service cgit-service-type)
28044 The @code{file-object} type designates either a file-like object
28045 (@pxref{G-Expressions, file-like objects}) or a string.
28047 @c %start of fragment
28049 Available @code{cgit-configuration} fields are:
28051 @deftypevr {@code{cgit-configuration} parameter} package package
28056 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
28057 NGINX configuration.
28061 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
28062 Specifies a command which will be invoked to format the content of about
28063 pages (both top-level and for each repository).
28065 Defaults to @samp{""}.
28069 @deftypevr {@code{cgit-configuration} parameter} string agefile
28070 Specifies a path, relative to each repository path, which can be used to
28071 specify the date and time of the youngest commit in the repository.
28073 Defaults to @samp{""}.
28077 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
28078 Specifies a command that will be invoked for authenticating repository
28081 Defaults to @samp{""}.
28085 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
28086 Flag which, when set to @samp{age}, enables date ordering in the branch
28087 ref list, and when set @samp{name} enables ordering by branch name.
28089 Defaults to @samp{"name"}.
28093 @deftypevr {@code{cgit-configuration} parameter} string cache-root
28094 Path used to store the cgit cache entries.
28096 Defaults to @samp{"/var/cache/cgit"}.
28100 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
28101 Number which specifies the time-to-live, in minutes, for the cached
28102 version of repository pages accessed with a fixed SHA1.
28104 Defaults to @samp{-1}.
28108 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
28109 Number which specifies the time-to-live, in minutes, for the cached
28110 version of repository pages accessed without a fixed SHA1.
28112 Defaults to @samp{5}.
28116 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
28117 Number which specifies the time-to-live, in minutes, for the cached
28118 version of the repository summary page.
28120 Defaults to @samp{5}.
28124 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
28125 Number which specifies the time-to-live, in minutes, for the cached
28126 version of the repository index page.
28128 Defaults to @samp{5}.
28132 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
28133 Number which specifies the time-to-live, in minutes, for the result of
28134 scanning a path for Git repositories.
28136 Defaults to @samp{15}.
28140 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
28141 Number which specifies the time-to-live, in minutes, for the cached
28142 version of the repository about page.
28144 Defaults to @samp{15}.
28148 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
28149 Number which specifies the time-to-live, in minutes, for the cached
28150 version of snapshots.
28152 Defaults to @samp{5}.
28156 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
28157 The maximum number of entries in the cgit cache. When set to @samp{0},
28158 caching is disabled.
28160 Defaults to @samp{0}.
28164 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
28165 Sort items in the repo list case sensitively.
28167 Defaults to @samp{#t}.
28171 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
28172 List of common prefixes which, when combined with a repository URL,
28173 generates valid clone URLs for the repository.
28175 Defaults to @samp{()}.
28179 @deftypevr {@code{cgit-configuration} parameter} list clone-url
28180 List of @code{clone-url} templates.
28182 Defaults to @samp{()}.
28186 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
28187 Command which will be invoked to format commit messages.
28189 Defaults to @samp{""}.
28193 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
28194 Flag which, when set to @samp{date}, enables strict date ordering in the
28195 commit log, and when set to @samp{topo} enables strict topological
28198 Defaults to @samp{"git log"}.
28202 @deftypevr {@code{cgit-configuration} parameter} file-object css
28203 URL which specifies the css document to include in all cgit pages.
28205 Defaults to @samp{"/share/cgit/cgit.css"}.
28209 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
28210 Specifies a command which will be invoked to format names and email
28211 address of committers, authors, and taggers, as represented in various
28212 places throughout the cgit interface.
28214 Defaults to @samp{""}.
28218 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
28219 Flag which, when set to @samp{#t}, will make cgit generate a HTML
28220 fragment suitable for embedding in other HTML pages.
28222 Defaults to @samp{#f}.
28226 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
28227 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
28228 commit history graph to the left of the commit messages in the
28229 repository log page.
28231 Defaults to @samp{#f}.
28235 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
28236 Flag which, when set to @samp{#t}, allows all filter settings to be
28237 overridden in repository-specific cgitrc files.
28239 Defaults to @samp{#f}.
28243 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
28244 Flag which, when set to @samp{#t}, allows users to follow a file in the
28247 Defaults to @samp{#f}.
28251 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
28252 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
28255 Defaults to @samp{#t}.
28259 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
28260 Flag which, when set to @samp{#t}, will make cgit generate extra links
28261 "summary", "commit", "tree" for each repo in the repository index.
28263 Defaults to @samp{#f}.
28267 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
28268 Flag which, when set to @samp{#t}, will make cgit display the owner of
28269 each repo in the repository index.
28271 Defaults to @samp{#t}.
28275 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
28276 Flag which, when set to @samp{#t}, will make cgit print the number of
28277 modified files for each commit on the repository log page.
28279 Defaults to @samp{#f}.
28283 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
28284 Flag which, when set to @samp{#t}, will make cgit print the number of
28285 added and removed lines for each commit on the repository log page.
28287 Defaults to @samp{#f}.
28291 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
28292 Flag which, when set to @code{#t}, will make cgit display remote
28293 branches in the summary and refs views.
28295 Defaults to @samp{#f}.
28299 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
28300 Flag which, when set to @code{1}, will make cgit use the subject of the
28301 parent commit as link text when generating links to parent commits in
28304 Defaults to @samp{#f}.
28308 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
28309 Flag which, when set to @samp{#t}, will make cgit use the subject of the
28310 parent commit as link text when generating links to parent commits in
28313 Defaults to @samp{#f}.
28317 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
28318 Flag which, when set to @samp{#t}, will make cgit generate linenumber
28319 links for plaintext blobs printed in the tree view.
28321 Defaults to @samp{#t}.
28325 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
28326 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
28327 set any repo specific settings.
28329 Defaults to @samp{#f}.
28333 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
28334 URL used as link to a shortcut icon for cgit.
28336 Defaults to @samp{"/favicon.ico"}.
28340 @deftypevr {@code{cgit-configuration} parameter} string footer
28341 The content of the file specified with this option will be included
28342 verbatim at the bottom of all pages (i.e.@: it replaces the standard
28343 "generated by..."@: message).
28345 Defaults to @samp{""}.
28349 @deftypevr {@code{cgit-configuration} parameter} string head-include
28350 The content of the file specified with this option will be included
28351 verbatim in the HTML HEAD section on all pages.
28353 Defaults to @samp{""}.
28357 @deftypevr {@code{cgit-configuration} parameter} string header
28358 The content of the file specified with this option will be included
28359 verbatim at the top of all pages.
28361 Defaults to @samp{""}.
28365 @deftypevr {@code{cgit-configuration} parameter} file-object include
28366 Name of a configfile to include before the rest of the current config-
28369 Defaults to @samp{""}.
28373 @deftypevr {@code{cgit-configuration} parameter} string index-header
28374 The content of the file specified with this option will be included
28375 verbatim above the repository index.
28377 Defaults to @samp{""}.
28381 @deftypevr {@code{cgit-configuration} parameter} string index-info
28382 The content of the file specified with this option will be included
28383 verbatim below the heading on the repository index page.
28385 Defaults to @samp{""}.
28389 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
28390 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
28391 in the servers timezone.
28393 Defaults to @samp{#f}.
28397 @deftypevr {@code{cgit-configuration} parameter} file-object logo
28398 URL which specifies the source of an image which will be used as a logo
28401 Defaults to @samp{"/share/cgit/cgit.png"}.
28405 @deftypevr {@code{cgit-configuration} parameter} string logo-link
28406 URL loaded when clicking on the cgit logo image.
28408 Defaults to @samp{""}.
28412 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
28413 Command which will be invoked to format the Owner column of the main
28416 Defaults to @samp{""}.
28420 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
28421 Number of items to display in atom feeds view.
28423 Defaults to @samp{10}.
28427 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
28428 Number of entries to list per page in "log" view.
28430 Defaults to @samp{50}.
28434 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
28435 Number of commit message characters to display in "log" view.
28437 Defaults to @samp{80}.
28441 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
28442 Specifies the number of entries to list per page on the repository index
28445 Defaults to @samp{50}.
28449 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
28450 Specifies the maximum number of repo description characters to display
28451 on the repository index page.
28453 Defaults to @samp{80}.
28457 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
28458 Specifies the maximum size of a blob to display HTML for in KBytes.
28460 Defaults to @samp{0}.
28464 @deftypevr {@code{cgit-configuration} parameter} string max-stats
28465 Maximum statistics period. Valid values are @samp{week},@samp{month},
28466 @samp{quarter} and @samp{year}.
28468 Defaults to @samp{""}.
28472 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
28473 Mimetype for the specified filename extension.
28475 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
28476 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
28477 "image/png") (svg "image/svg+xml"))}.
28481 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
28482 Specifies the file to use for automatic mimetype lookup.
28484 Defaults to @samp{""}.
28488 @deftypevr {@code{cgit-configuration} parameter} string module-link
28489 Text which will be used as the formatstring for a hyperlink when a
28490 submodule is printed in a directory listing.
28492 Defaults to @samp{""}.
28496 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
28497 If set to the value @samp{#t} caching will be disabled.
28499 Defaults to @samp{#f}.
28503 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
28504 If set to @samp{#t} showing full author email addresses will be
28507 Defaults to @samp{#f}.
28511 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
28512 Flag which, when set to @samp{#t}, will make cgit omit the standard
28513 header on all pages.
28515 Defaults to @samp{#f}.
28519 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
28520 A list of subdirectories inside of @code{repository-directory}, relative
28521 to it, that should loaded as Git repositories. An empty list means that
28522 all subdirectories will be loaded.
28524 Defaults to @samp{()}.
28528 @deftypevr {@code{cgit-configuration} parameter} file-object readme
28529 Text which will be used as default value for @code{cgit-repo-readme}.
28531 Defaults to @samp{""}.
28535 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
28536 If set to @code{#t} and @code{repository-directory} is enabled, if any
28537 repositories are found with a suffix of @code{.git}, this suffix will be
28538 removed for the URL and name.
28540 Defaults to @samp{#f}.
28544 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
28545 Maximum number of files to consider when detecting renames.
28547 Defaults to @samp{-1}.
28551 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
28552 The way in which repositories in each section are sorted.
28554 Defaults to @samp{""}.
28558 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
28559 Text used as content for the @code{robots} meta-tag.
28561 Defaults to @samp{("noindex" "nofollow")}.
28565 @deftypevr {@code{cgit-configuration} parameter} string root-desc
28566 Text printed below the heading on the repository index page.
28568 Defaults to @samp{"a fast webinterface for the git dscm"}.
28572 @deftypevr {@code{cgit-configuration} parameter} string root-readme
28573 The content of the file specified with this option will be included
28574 verbatim below the ``about'' link on the repository index page.
28576 Defaults to @samp{""}.
28580 @deftypevr {@code{cgit-configuration} parameter} string root-title
28581 Text printed as heading on the repository index page.
28583 Defaults to @samp{""}.
28587 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
28588 If set to @samp{#t} and repository-directory is enabled,
28589 repository-directory will recurse into directories whose name starts
28590 with a period. Otherwise, repository-directory will stay away from such
28591 directories, considered as ``hidden''. Note that this does not apply to
28592 the @file{.git} directory in non-bare repos.
28594 Defaults to @samp{#f}.
28598 @deftypevr {@code{cgit-configuration} parameter} list snapshots
28599 Text which specifies the default set of snapshot formats that cgit
28600 generates links for.
28602 Defaults to @samp{()}.
28606 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
28607 Name of the directory to scan for repositories (represents
28610 Defaults to @samp{"/srv/git"}.
28614 @deftypevr {@code{cgit-configuration} parameter} string section
28615 The name of the current repository section - all repositories defined
28616 after this option will inherit the current section name.
28618 Defaults to @samp{""}.
28622 @deftypevr {@code{cgit-configuration} parameter} string section-sort
28623 Flag which, when set to @samp{1}, will sort the sections on the
28624 repository listing by name.
28626 Defaults to @samp{""}.
28630 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
28631 A number which, if defined prior to repository-directory, specifies how
28632 many path elements from each repo path to use as a default section name.
28634 Defaults to @samp{0}.
28638 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
28639 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
28642 Defaults to @samp{#f}.
28646 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
28647 Specifies a command which will be invoked to format plaintext blobs in
28650 Defaults to @samp{""}.
28654 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
28655 Specifies the number of branches to display in the repository ``summary''
28658 Defaults to @samp{10}.
28662 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
28663 Specifies the number of log entries to display in the repository
28666 Defaults to @samp{10}.
28670 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
28671 Specifies the number of tags to display in the repository ``summary''
28674 Defaults to @samp{10}.
28678 @deftypevr {@code{cgit-configuration} parameter} string strict-export
28679 Filename which, if specified, needs to be present within the repository
28680 for cgit to allow access to that repository.
28682 Defaults to @samp{""}.
28686 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
28687 URL which, if specified, will be used as root for all cgit links.
28689 Defaults to @samp{"/"}.
28693 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
28694 A list of @dfn{cgit-repo} records to use with config.
28696 Defaults to @samp{()}.
28698 Available @code{repository-cgit-configuration} fields are:
28700 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
28701 A mask of snapshot formats for this repo that cgit generates links for,
28702 restricted by the global @code{snapshots} setting.
28704 Defaults to @samp{()}.
28708 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
28709 Override the default @code{source-filter}.
28711 Defaults to @samp{""}.
28715 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
28716 The relative URL used to access the repository.
28718 Defaults to @samp{""}.
28722 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
28723 Override the default @code{about-filter}.
28725 Defaults to @samp{""}.
28729 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
28730 Flag which, when set to @samp{age}, enables date ordering in the branch
28731 ref list, and when set to @samp{name} enables ordering by branch name.
28733 Defaults to @samp{""}.
28737 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
28738 A list of URLs which can be used to clone repo.
28740 Defaults to @samp{()}.
28744 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
28745 Override the default @code{commit-filter}.
28747 Defaults to @samp{""}.
28751 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
28752 Flag which, when set to @samp{date}, enables strict date ordering in the
28753 commit log, and when set to @samp{topo} enables strict topological
28756 Defaults to @samp{""}.
28760 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
28761 The name of the default branch for this repository. If no such branch
28762 exists in the repository, the first branch name (when sorted) is used as
28763 default instead. By default branch pointed to by HEAD, or ``master'' if
28764 there is no suitable HEAD.
28766 Defaults to @samp{""}.
28770 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
28771 The value to show as repository description.
28773 Defaults to @samp{""}.
28777 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
28778 The value to show as repository homepage.
28780 Defaults to @samp{""}.
28784 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
28785 Override the default @code{email-filter}.
28787 Defaults to @samp{""}.
28791 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
28792 A flag which can be used to disable the global setting
28793 @code{enable-commit-graph?}.
28795 Defaults to @samp{disabled}.
28799 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
28800 A flag which can be used to disable the global setting
28801 @code{enable-log-filecount?}.
28803 Defaults to @samp{disabled}.
28807 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
28808 A flag which can be used to disable the global setting
28809 @code{enable-log-linecount?}.
28811 Defaults to @samp{disabled}.
28815 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
28816 Flag which, when set to @code{#t}, will make cgit display remote
28817 branches in the summary and refs views.
28819 Defaults to @samp{disabled}.
28823 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
28824 A flag which can be used to override the global setting
28825 @code{enable-subject-links?}.
28827 Defaults to @samp{disabled}.
28831 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
28832 A flag which can be used to override the global setting
28833 @code{enable-html-serving?}.
28835 Defaults to @samp{disabled}.
28839 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
28840 Flag which, when set to @code{#t}, hides the repository from the
28843 Defaults to @samp{#f}.
28847 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
28848 Flag which, when set to @samp{#t}, ignores the repository.
28850 Defaults to @samp{#f}.
28854 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
28855 URL which specifies the source of an image which will be used as a logo
28856 on this repo’s pages.
28858 Defaults to @samp{""}.
28862 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
28863 URL loaded when clicking on the cgit logo image.
28865 Defaults to @samp{""}.
28869 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
28870 Override the default @code{owner-filter}.
28872 Defaults to @samp{""}.
28876 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
28877 Text which will be used as the formatstring for a hyperlink when a
28878 submodule is printed in a directory listing. The arguments for the
28879 formatstring are the path and SHA1 of the submodule commit.
28881 Defaults to @samp{""}.
28885 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
28886 Text which will be used as the formatstring for a hyperlink when a
28887 submodule with the specified subdirectory path is printed in a directory
28890 Defaults to @samp{()}.
28894 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
28895 Override the default maximum statistics period.
28897 Defaults to @samp{""}.
28901 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
28902 The value to show as repository name.
28904 Defaults to @samp{""}.
28908 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
28909 A value used to identify the owner of the repository.
28911 Defaults to @samp{""}.
28915 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
28916 An absolute path to the repository directory.
28918 Defaults to @samp{""}.
28922 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
28923 A path (relative to repo) which specifies a file to include verbatim as
28924 the ``About'' page for this repo.
28926 Defaults to @samp{""}.
28930 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
28931 The name of the current repository section - all repositories defined
28932 after this option will inherit the current section name.
28934 Defaults to @samp{""}.
28938 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
28939 Extra options will be appended to cgitrc file.
28941 Defaults to @samp{()}.
28947 @deftypevr {@code{cgit-configuration} parameter} list extra-options
28948 Extra options will be appended to cgitrc file.
28950 Defaults to @samp{()}.
28955 @c %end of fragment
28957 However, it could be that you just want to get a @code{cgitrc} up and
28958 running. In that case, you can pass an @code{opaque-cgit-configuration}
28959 as a record to @code{cgit-service-type}. As its name indicates, an
28960 opaque configuration does not have easy reflective capabilities.
28962 Available @code{opaque-cgit-configuration} fields are:
28964 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
28968 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
28969 The contents of the @code{cgitrc}, as a string.
28972 For example, if your @code{cgitrc} is just the empty string, you
28973 could instantiate a cgit service like this:
28976 (service cgit-service-type
28977 (opaque-cgit-configuration
28981 @subsubheading Gitolite Service
28983 @cindex Gitolite service
28984 @cindex Git, hosting
28985 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
28986 repositories on a central server.
28988 Gitolite can handle multiple repositories and users, and supports flexible
28989 configuration of the permissions for the users on the repositories.
28991 The following example will configure Gitolite using the default @code{git}
28992 user, and the provided SSH public key.
28995 (service gitolite-service-type
28996 (gitolite-configuration
28997 (admin-pubkey (plain-file
28999 "ssh-rsa AAAA... guix@@example.com"))))
29002 Gitolite is configured through a special admin repository which you can clone,
29003 for example, if you setup Gitolite on @code{example.com}, you would run the
29004 following command to clone the admin repository.
29007 git clone git@@example.com:gitolite-admin
29010 When the Gitolite service is activated, the provided @code{admin-pubkey} will
29011 be inserted in to the @file{keydir} directory in the gitolite-admin
29012 repository. If this results in a change in the repository, it will be
29013 committed using the message ``gitolite setup by GNU Guix''.
29015 @deftp {Data Type} gitolite-configuration
29016 Data type representing the configuration for @code{gitolite-service-type}.
29019 @item @code{package} (default: @var{gitolite})
29020 Gitolite package to use.
29022 @item @code{user} (default: @var{git})
29023 User to use for Gitolite. This will be user that you use when accessing
29026 @item @code{group} (default: @var{git})
29027 Group to use for Gitolite.
29029 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
29030 Directory in which to store the Gitolite configuration and repositories.
29032 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
29033 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
29034 representing the configuration for Gitolite.
29036 @item @code{admin-pubkey} (default: @var{#f})
29037 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
29038 setup Gitolite. This will be inserted in to the @file{keydir} directory
29039 within the gitolite-admin repository.
29041 To specify the SSH key as a string, use the @code{plain-file} function.
29044 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
29050 @deftp {Data Type} gitolite-rc-file
29051 Data type representing the Gitolite RC file.
29054 @item @code{umask} (default: @code{#o0077})
29055 This controls the permissions Gitolite sets on the repositories and their
29058 A value like @code{#o0027} will give read access to the group used by Gitolite
29059 (by default: @code{git}). This is necessary when using Gitolite with software
29060 like cgit or gitweb.
29062 @item @code{git-config-keys} (default: @code{""})
29063 Gitolite allows you to set git config values using the @samp{config} keyword. This
29064 setting allows control over the config keys to accept.
29066 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
29067 Set the role names allowed to be used by users running the perms command.
29069 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
29070 This setting controls the commands and features to enable within Gitolite.
29076 @node Game Services
29077 @subsection Game Services
29079 @subsubheading The Battle for Wesnoth Service
29081 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
29082 based tactical strategy game, with several single player campaigns, and
29083 multiplayer games (both networked and local).
29085 @defvar {Scheme Variable} wesnothd-service-type
29086 Service type for the wesnothd service. Its value must be a
29087 @code{wesnothd-configuration} object. To run wesnothd in the default
29088 configuration, instantiate it as:
29091 (service wesnothd-service-type)
29095 @deftp {Data Type} wesnothd-configuration
29096 Data type representing the configuration of @command{wesnothd}.
29099 @item @code{package} (default: @code{wesnoth-server})
29100 The wesnoth server package to use.
29102 @item @code{port} (default: @code{15000})
29103 The port to bind the server to.
29108 @node PAM Mount Service
29109 @subsection PAM Mount Service
29112 The @code{(gnu services pam-mount)} module provides a service allowing
29113 users to mount volumes when they log in. It should be able to mount any
29114 volume format supported by the system.
29116 @defvar {Scheme Variable} pam-mount-service-type
29117 Service type for PAM Mount support.
29120 @deftp {Data Type} pam-mount-configuration
29121 Data type representing the configuration of PAM Mount.
29123 It takes the following parameters:
29127 The configuration rules that will be used to generate
29128 @file{/etc/security/pam_mount.conf.xml}.
29130 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
29131 Guile Reference Manual}), and the default ones don't mount anything for
29135 `((debug (@@ (enable "0")))
29136 (mntoptions (@@ (allow ,(string-join
29137 '("nosuid" "nodev" "loop"
29138 "encryption" "fsck" "nonempty"
29139 "allow_root" "allow_other")
29141 (mntoptions (@@ (require "nosuid,nodev")))
29142 (logout (@@ (wait "0")
29146 (mkmountpoint (@@ (enable "1")
29150 Some @code{volume} elements must be added to automatically mount volumes
29151 at login. Here's an example allowing the user @code{alice} to mount her
29152 encrypted @env{HOME} directory and allowing the user @code{bob} to mount
29153 the partition where he stores his data:
29156 (define pam-mount-rules
29157 `((debug (@@ (enable "0")))
29158 (volume (@@ (user "alice")
29161 (mountpoint "/home/alice")))
29162 (volume (@@ (user "bob")
29165 (mountpoint "/home/bob/data")
29166 (options "defaults,autodefrag,compress")))
29167 (mntoptions (@@ (allow ,(string-join
29168 '("nosuid" "nodev" "loop"
29169 "encryption" "fsck" "nonempty"
29170 "allow_root" "allow_other")
29172 (mntoptions (@@ (require "nosuid,nodev")))
29173 (logout (@@ (wait "0")
29177 (mkmountpoint (@@ (enable "1")
29178 (remove "true")))))
29180 (service pam-mount-service-type
29181 (pam-mount-configuration
29182 (rules pam-mount-rules)))
29185 The complete list of possible options can be found in the man page for
29186 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
29191 @node Guix Services
29192 @subsection Guix Services
29194 @subsubheading Guix Build Coordinator
29195 The @uref{https://git.cbaines.net/guix/build-coordinator/,Guix Build
29196 Coordinator} aids in distributing derivation builds among machines
29197 running an @dfn{agent}. The build daemon is still used to build the
29198 derivations, but the Guix Build Coordinator manages allocating builds
29199 and working with the results.
29202 This service is considered experimental. Configuration options may be
29203 changed in a backwards-incompatible manner, and not all features have
29204 been thorougly tested.
29207 The Guix Build Coordinator consists of one @dfn{coordinator}, and one or
29208 more connected @dfn{agent} processes. The coordinator process handles
29209 clients submitting builds, and allocating builds to agents. The agent
29210 processes talk to a build daemon to actually perform the builds, then
29211 send the results back to the coordinator.
29213 There is a script to run the coordinator component of the Guix Build
29214 Coordinator, but the Guix service uses a custom Guile script instead, to
29215 provide better integration with G-expressions used in the configuration.
29217 @defvar {Scheme Variable} guix-build-coordinator-service-type
29218 Service type for the Guix Build Coordinator. Its value must be a
29219 @code{guix-build-coordinator-configuration} object.
29222 @deftp {Data Type} guix-build-coordinator-configuration
29223 Data type representing the configuration of the Guix Build Coordinator.
29226 @item @code{package} (default: @code{guix-build-coordinator})
29227 The Guix Build Coordinator package to use.
29229 @item @code{user} (default: @code{"guix-build-coordinator"})
29230 The system user to run the service as.
29232 @item @code{group} (default: @code{"guix-build-coordinator"})
29233 The system group to run the service as.
29235 @item @code{database-uri-string} (default: @code{"sqlite:///var/lib/guix-build-coordinator/guix_build_coordinator.db"})
29236 The URI to use for the database.
29238 @item @code{agent-communication-uri} (default: @code{"http://0.0.0.0:8745"})
29239 The URI describing how to listen to requests from agent processes.
29241 @item @code{client-communication-uri} (default: @code{"http://127.0.0.1:8746"})
29242 The URI describing how to listen to requests from clients. The client
29243 API allows submitting builds and currently isn't authenticated, so take
29244 care when configuring this value.
29246 @item @code{allocation-strategy} (default: @code{#~basic-build-allocation-strategy})
29247 A G-expression for the allocation strategy to be used. This is a
29248 procedure that takes the datastore as an argument and populates the
29249 allocation plan in the database.
29251 @item @code{hooks} (default: @var{'()})
29252 An association list of hooks. These provide a way to execute arbitrary
29253 code upon certain events, like a build result being processed.
29255 @item @code{guile} (default: @code{guile-3.0-latest})
29256 The Guile package with which to run the Guix Build Coordinator.
29261 @defvar {Scheme Variable} guix-build-coordinator-agent-service-type
29262 Service type for a Guix Build Coordinator agent. Its value must be a
29263 @code{guix-build-coordinator-agent-configuration} object.
29266 @deftp {Data Type} guix-build-coordinator-agent-configuration
29267 Data type representing the configuration a Guix Build Coordinator agent.
29270 @item @code{package} (default: @code{guix-build-coordinator})
29271 The Guix Build Coordinator package to use.
29273 @item @code{user} (default: @code{"guix-build-coordinator-agent"})
29274 The system user to run the service as.
29276 @item @code{coordinator} (default: @code{"http://localhost:8745"})
29277 The URI to use when connecting to the coordinator.
29280 The UUID of the agent. This should be generated by the coordinator
29281 process, stored in the coordinator database, and used by the intended
29284 @item @code{password} (default: @code{#f})
29285 The password to use when connecting to the coordinator. A file to read
29286 the password from can also be specified, and this is more secure.
29288 @item @code{password-file} (default: @code{#f})
29289 A file containing the password to use when connecting to the
29292 @item @code{systems} (default: @code{#f})
29293 The systems for which this agent should fetch builds. The agent process
29294 will use the current system it's running on as the default.
29296 @item @code{max-parallel-builds} (default: @code{1})
29297 The number of builds to perform in parallel.
29299 @item @code{derivation-substitute-urls} (default: @code{#f})
29300 URLs from which to attempt to fetch substitutes for derivations, if the
29301 derivations aren't already available.
29303 @item @code{non-derivation-substitute-urls} (default: @code{#f})
29304 URLs from which to attempt to fetch substitutes for build inputs, if the
29305 input store items aren't already available.
29310 The Guix Build Coordinator package contains a script to query an
29311 instance of the Guix Data Service for derivations to build, and then
29312 submit builds for those derivations to the coordinator. The service
29313 type below assists in running this script. This is an additional tool
29314 that may be useful when building derivations contained within an
29315 instance of the Guix Data Service.
29317 @defvar {Scheme Variable} guix-build-coordinator-queue-builds-service-type
29318 Service type for the
29319 guix-build-coordinator-queue-builds-from-guix-data-service script. Its
29320 value must be a @code{guix-build-coordinator-queue-builds-configuration}
29324 @deftp {Data Type} guix-build-coordinator-queue-builds-configuration
29325 Data type representing the options to the queue builds from guix data
29329 @item @code{package} (default: @code{guix-build-coordinator})
29330 The Guix Build Coordinator package to use.
29332 @item @code{user} (default: @code{"guix-build-coordinator-queue-builds"})
29333 The system user to run the service as.
29335 @item @code{coordinator} (default: @code{"http://localhost:8745"})
29336 The URI to use when connecting to the coordinator.
29338 @item @code{systems} (default: @code{#f})
29339 The systems for which to fetch derivations to build.
29341 @item @code{systems-and-targets} (default: @code{#f})
29342 An association list of system and target pairs for which to fetch
29343 derivations to build.
29345 @item @code{guix-data-service} (default: @code{"https://data.guix.gnu.org"})
29346 The Guix Data Service instance from which to query to find out about
29347 derivations to build.
29349 @item @code{processed-commits-file} (default: @code{"/var/cache/guix-build-coordinator-queue-builds/processed-commits"})
29350 A file to record which commits have been processed, to avoid needlessly
29351 processing them again if the service is restarted.
29356 @subsubheading Guix Data Service
29357 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
29358 and provides data about GNU Guix. This includes information about
29359 packages, derivations and lint warnings.
29361 The data is stored in a PostgreSQL database, and available through a web
29364 @defvar {Scheme Variable} guix-data-service-type
29365 Service type for the Guix Data Service. Its value must be a
29366 @code{guix-data-service-configuration} object. The service optionally
29367 extends the getmail service, as the guix-commits mailing list is used to
29368 find out about changes in the Guix git repository.
29371 @deftp {Data Type} guix-data-service-configuration
29372 Data type representing the configuration of the Guix Data Service.
29375 @item @code{package} (default: @code{guix-data-service})
29376 The Guix Data Service package to use.
29378 @item @code{user} (default: @code{"guix-data-service"})
29379 The system user to run the service as.
29381 @item @code{group} (default: @code{"guix-data-service"})
29382 The system group to run the service as.
29384 @item @code{port} (default: @code{8765})
29385 The port to bind the web service to.
29387 @item @code{host} (default: @code{"127.0.0.1"})
29388 The host to bind the web service to.
29390 @item @code{getmail-idle-mailboxes} (default: @code{#f})
29391 If set, this is the list of mailboxes that the getmail service will be
29392 configured to listen to.
29394 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
29395 If set, this is the @code{getmail-retriever-configuration} object with
29396 which to configure getmail to fetch mail from the guix-commits mailing
29399 @item @code{extra-options} (default: @var{'()})
29400 Extra command line options for @code{guix-data-service}.
29402 @item @code{extra-process-jobs-options} (default: @var{'()})
29403 Extra command line options for @code{guix-data-service-process-jobs}.
29408 @node Linux Services
29409 @subsection Linux Services
29412 @cindex out of memory killer
29414 @cindex early out of memory daemon
29415 @subsubheading Early OOM Service
29417 @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
29418 Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
29419 space and provides a more responsive and configurable alternative to the
29420 in-kernel OOM killer. It is useful to prevent the system from becoming
29421 unresponsive when it runs out of memory.
29423 @deffn {Scheme Variable} earlyoom-service-type
29424 The service type for running @command{earlyoom}, the Early OOM daemon.
29425 Its value must be a @code{earlyoom-configuration} object, described
29426 below. The service can be instantiated in its default configuration
29430 (service earlyoom-service-type)
29434 @deftp {Data Type} earlyoom-configuration
29435 This is the configuration record for the @code{earlyoom-service-type}.
29438 @item @code{earlyoom} (default: @var{earlyoom})
29439 The Earlyoom package to use.
29441 @item @code{minimum-available-memory} (default: @code{10})
29442 The threshold for the minimum @emph{available} memory, in percentages.
29444 @item @code{minimum-free-swap} (default: @code{10})
29445 The threshold for the minimum free swap memory, in percentages.
29447 @item @code{prefer-regexp} (default: @code{#f})
29448 A regular expression (as a string) to match the names of the processes
29449 that should be preferably killed.
29451 @item @code{avoid-regexp} (default: @code{#f})
29452 A regular expression (as a string) to match the names of the processes
29453 that should @emph{not} be killed.
29455 @item @code{memory-report-interval} (default: @code{0})
29456 The interval in seconds at which a memory report is printed. It is
29457 disabled by default.
29459 @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
29460 A boolean indicating whether the positive adjustments set in
29461 @file{/proc/*/oom_score_adj} should be ignored.
29463 @item @code{show-debug-messages?} (default: @code{#f})
29464 A boolean indicating whether debug messages should be printed. The logs
29465 are saved at @file{/var/log/earlyoom.log}.
29467 @item @code{send-notification-command} (default: @code{#f})
29468 This can be used to provide a custom command used for sending
29474 @cindex kernel module loader
29475 @subsubheading Kernel Module Loader Service
29477 The kernel module loader service allows one to load loadable kernel
29478 modules at boot. This is especially useful for modules that don't
29479 autoload and need to be manually loaded, as it's the case with
29482 @deffn {Scheme Variable} kernel-module-loader-service-type
29483 The service type for loading loadable kernel modules at boot with
29484 @command{modprobe}. Its value must be a list of strings representing
29485 module names. For example loading the drivers provided by
29486 @code{ddcci-driver-linux}, in debugging mode by passing some module
29487 parameters, can be done as follow:
29490 (use-modules (gnu) (gnu services))
29491 (use-package-modules linux)
29492 (use-service-modules linux)
29494 (define ddcci-config
29495 (plain-file "ddcci.conf"
29496 "options ddcci dyndbg delay=120"))
29500 (services (cons* (service kernel-module-loader-service-type
29501 '("ddcci" "ddcci_backlight"))
29502 (simple-service 'ddcci-config etc-service-type
29503 (list `("modprobe.d/ddcci.conf"
29506 (kernel-loadable-modules (list ddcci-driver-linux)))
29511 @cindex compressed swap
29512 @cindex Compressed RAM-based block devices
29513 @subsubheading Zram Device Service
29515 The Zram device service provides a compressed swap device in system
29516 memory. The Linux Kernel documentation has more information about
29517 @uref{https://www.kernel.org/doc/html/latest/admin-guide/blockdev/zram.html,zram}
29520 @deffn {Scheme Variable} zram-device-service-type
29521 This service creates the zram block device, formats it as swap and
29522 enables it as a swap device. The service's value is a
29523 @code{zram-device-configuration} record.
29525 @deftp {Data Type} zram-device-configuration
29526 This is the data type representing the configuration for the zram-device
29530 @item @code{size} (default @code{"1G"})
29531 This is the amount of space you wish to provide for the zram device. It
29532 accepts a string and can be a number of bytes or use a suffix, eg.:
29533 @code{"512M"} or @code{1024000}.
29534 @item @code{compression-algorithm} (default @code{'lzo})
29535 This is the compression algorithm you wish to use. It is difficult to
29536 list all the possible compression options, but common ones supported by
29537 Guix's Linux Libre Kernel include @code{'lzo}, @code{'lz4} and @code{'zstd}.
29538 @item @code{memory-limit} (default @code{0})
29539 This is the maximum amount of memory which the zram device can use.
29540 Setting it to '0' disables the limit. While it is generally expected
29541 that compression will be 2:1, it is possible that uncompressable data
29542 can be written to swap and this is a method to limit how much memory can
29543 be used. It accepts a string and can be a number of bytes or use a
29544 suffix, eg.: @code{"2G"}.
29545 @item @code{priority} (default @code{-1})
29546 This is the priority of the swap device created from the zram device.
29547 @code{swapon} accepts values between -1 and 32767, with higher values
29548 indicating higher priority. Higher priority swap will generally be used
29555 @node Hurd Services
29556 @subsection Hurd Services
29558 @defvr {Scheme Variable} hurd-console-service-type
29559 This service starts the fancy @code{VGA} console client on the Hurd.
29561 The service's value is a @code{hurd-console-configuration} record.
29564 @deftp {Data Type} hurd-console-configuration
29565 This is the data type representing the configuration for the
29566 hurd-console-service.
29569 @item @code{hurd} (default: @var{hurd})
29570 The Hurd package to use.
29574 @defvr {Scheme Variable} hurd-getty-service-type
29575 This service starts a tty using the Hurd @code{getty} program.
29577 The service's value is a @code{hurd-getty-configuration} record.
29580 @deftp {Data Type} hurd-getty-configuration
29581 This is the data type representing the configuration for the
29582 hurd-getty-service.
29585 @item @code{hurd} (default: @var{hurd})
29586 The Hurd package to use.
29589 The name of the console this Getty runs on---e.g., @code{"tty1"}.
29591 @item @code{baud-rate} (default: @code{38400})
29592 An integer specifying the baud rate of the tty.
29597 @node Miscellaneous Services
29598 @subsection Miscellaneous Services
29600 @cindex fingerprint
29601 @subsubheading Fingerprint Service
29603 The @code{(gnu services authentication)} module provides a DBus service to
29604 read and identify fingerprints via a fingerprint sensor.
29606 @defvr {Scheme Variable} fprintd-service-type
29607 The service type for @command{fprintd}, which provides the fingerprint
29608 reading capability.
29611 (service fprintd-service-type)
29616 @subsubheading System Control Service
29618 The @code{(gnu services sysctl)} provides a service to configure kernel
29619 parameters at boot.
29621 @defvr {Scheme Variable} sysctl-service-type
29622 The service type for @command{sysctl}, which modifies kernel parameters
29623 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
29627 (service sysctl-service-type
29628 (sysctl-configuration
29629 (settings '(("net.ipv4.ip_forward" . "1")))))
29633 @deftp {Data Type} sysctl-configuration
29634 The data type representing the configuration of @command{sysctl}.
29637 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
29638 The @command{sysctl} executable to use.
29640 @item @code{settings} (default: @code{'()})
29641 An association list specifies kernel parameters and their values.
29646 @subsubheading PC/SC Smart Card Daemon Service
29648 The @code{(gnu services security-token)} module provides the following service
29649 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
29650 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
29651 manager that coordinates communications with smart card readers, smart cards
29652 and cryptographic tokens that are connected to the system.
29654 @defvr {Scheme Variable} pcscd-service-type
29655 Service type for the @command{pcscd} service. Its value must be a
29656 @code{pcscd-configuration} object. To run pcscd in the default
29657 configuration, instantiate it as:
29660 (service pcscd-service-type)
29664 @deftp {Data Type} pcscd-configuration
29665 The data type representing the configuration of @command{pcscd}.
29668 @item @code{pcsc-lite} (default: @code{pcsc-lite})
29669 The pcsc-lite package that provides pcscd.
29670 @item @code{usb-drivers} (default: @code{(list ccid)})
29671 List of packages that provide USB drivers to pcscd. Drivers are expected to be
29672 under @file{pcsc/drivers} in the store directory of the package.
29677 @subsubheading Lirc Service
29679 The @code{(gnu services lirc)} module provides the following service.
29681 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
29682 [#:device #f] [#:driver #f] [#:config-file #f] @
29683 [#:extra-options '()]
29684 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
29685 decodes infrared signals from remote controls.
29687 Optionally, @var{device}, @var{driver} and @var{config-file}
29688 (configuration file name) may be specified. See @command{lircd} manual
29691 Finally, @var{extra-options} is a list of additional command-line options
29692 passed to @command{lircd}.
29696 @subsubheading Spice Service
29698 The @code{(gnu services spice)} module provides the following service.
29700 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
29701 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
29702 that enables sharing the clipboard with a vm and setting the guest display
29703 resolution when the graphical console window resizes.
29706 @cindex inputattach
29707 @subsubheading inputattach Service
29709 @cindex tablet input, for Xorg
29710 @cindex touchscreen input, for Xorg
29711 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
29712 use input devices such as Wacom tablets, touchscreens, or joysticks with the
29713 Xorg display server.
29715 @deffn {Scheme Variable} inputattach-service-type
29716 Type of a service that runs @command{inputattach} on a device and
29717 dispatches events from it.
29720 @deftp {Data Type} inputattach-configuration
29722 @item @code{device-type} (default: @code{"wacom"})
29723 The type of device to connect to. Run @command{inputattach --help}, from the
29724 @code{inputattach} package, to see the list of supported device types.
29726 @item @code{device} (default: @code{"/dev/ttyS0"})
29727 The device file to connect to the device.
29729 @item @code{baud-rate} (default: @code{#f})
29730 Baud rate to use for the serial connection.
29731 Should be a number or @code{#f}.
29733 @item @code{log-file} (default: @code{#f})
29734 If true, this must be the name of a file to log messages to.
29738 @subsubheading Dictionary Service
29740 The @code{(gnu services dict)} module provides the following service:
29742 @defvr {Scheme Variable} dicod-service-type
29743 This is the type of the service that runs the @command{dicod} daemon, an
29744 implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
29747 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
29748 Return a service that runs the @command{dicod} daemon, an implementation
29749 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
29751 The optional @var{config} argument specifies the configuration for
29752 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
29753 default it serves the GNU Collaborative International Dictionary of English.
29755 You can add @command{open localhost} to your @file{~/.dico} file to make
29756 @code{localhost} the default server for @command{dico} client
29757 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
29760 @deftp {Data Type} dicod-configuration
29761 Data type representing the configuration of dicod.
29764 @item @code{dico} (default: @var{dico})
29765 Package object of the GNU Dico dictionary server.
29767 @item @code{interfaces} (default: @var{'("localhost")})
29768 This is the list of IP addresses and ports and possibly socket file
29769 names to listen to (@pxref{Server Settings, @code{listen} directive,,
29770 dico, GNU Dico Manual}).
29772 @item @code{handlers} (default: @var{'()})
29773 List of @code{<dicod-handler>} objects denoting handlers (module instances).
29775 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
29776 List of @code{<dicod-database>} objects denoting dictionaries to be served.
29780 @deftp {Data Type} dicod-handler
29781 Data type representing a dictionary handler (module instance).
29785 Name of the handler (module instance).
29787 @item @code{module} (default: @var{#f})
29788 Name of the dicod module of the handler (instance). If it is @code{#f},
29789 the module has the same name as the handler.
29790 (@pxref{Modules,,, dico, GNU Dico Manual}).
29792 @item @code{options}
29793 List of strings or gexps representing the arguments for the module handler
29797 @deftp {Data Type} dicod-database
29798 Data type representing a dictionary database.
29802 Name of the database, will be used in DICT commands.
29804 @item @code{handler}
29805 Name of the dicod handler (module instance) used by this database
29806 (@pxref{Handlers,,, dico, GNU Dico Manual}).
29808 @item @code{complex?} (default: @var{#f})
29809 Whether the database configuration complex. The complex configuration
29810 will need a corresponding @code{<dicod-handler>} object, otherwise not.
29812 @item @code{options}
29813 List of strings or gexps representing the arguments for the database
29814 (@pxref{Databases,,, dico, GNU Dico Manual}).
29818 @defvr {Scheme Variable} %dicod-database:gcide
29819 A @code{<dicod-database>} object serving the GNU Collaborative International
29820 Dictionary of English using the @code{gcide} package.
29823 The following is an example @code{dicod-service} configuration.
29826 (dicod-service #:config
29827 (dicod-configuration
29828 (handlers (list (dicod-handler
29832 (list #~(string-append "dbdir=" #$wordnet))))))
29833 (databases (list (dicod-database
29836 (handler "wordnet")
29837 (options '("database=wn")))
29838 %dicod-database:gcide))))
29842 @subsubheading Docker Service
29844 The @code{(gnu services docker)} module provides the following services.
29846 @defvr {Scheme Variable} docker-service-type
29848 This is the type of the service that runs @url{https://www.docker.com,Docker},
29849 a daemon that can execute application bundles (sometimes referred to as
29850 ``containers'') in isolated environments.
29854 @deftp {Data Type} docker-configuration
29855 This is the data type representing the configuration of Docker and Containerd.
29859 @item @code{package} (default: @code{docker})
29860 The Docker daemon package to use.
29862 @item @code{package} (default: @code{docker-cli})
29863 The Docker client package to use.
29865 @item @code{containerd} (default: @var{containerd})
29866 The Containerd package to use.
29868 @item @code{proxy} (default @var{docker-libnetwork-cmd-proxy})
29869 The Docker user-land networking proxy package to use.
29871 @item @code{enable-proxy?} (default @code{#t})
29872 Enable or disable the use of the Docker user-land networking proxy.
29874 @item @code{debug?} (default @code{#f})
29875 Enable or disable debug output.
29877 @item @code{enable-iptables?} (default @code{#t})
29878 Enable or disable the addition of iptables rules.
29883 @cindex Singularity, container service
29884 @defvr {Scheme Variable} singularity-service-type
29885 This is the type of the service that allows you to run
29886 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
29887 create and run application bundles (aka. ``containers''). The value for this
29888 service is the Singularity package to use.
29890 The service does not install a daemon; instead, it installs helper programs as
29891 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
29892 @command{singularity run} and similar commands.
29896 @subsubheading Auditd Service
29898 The @code{(gnu services auditd)} module provides the following service.
29900 @defvr {Scheme Variable} auditd-service-type
29902 This is the type of the service that runs
29903 @url{https://people.redhat.com/sgrubb/audit/,auditd},
29904 a daemon that tracks security-relevant information on your system.
29906 Examples of things that can be tracked:
29916 Failed login attempts
29923 @command{auditctl} from the @code{audit} package can be used in order
29924 to add or remove events to be tracked (until the next reboot).
29925 In order to permanently track events, put the command line arguments
29926 of auditctl into a file called @code{audit.rules} in the configuration
29927 directory (see below).
29928 @command{aureport} from the @code{audit} package can be used in order
29929 to view a report of all recorded events.
29930 The audit daemon by default logs into the file
29931 @file{/var/log/audit.log}.
29935 @deftp {Data Type} auditd-configuration
29936 This is the data type representing the configuration of auditd.
29940 @item @code{audit} (default: @code{audit})
29941 The audit package to use.
29943 @item @code{configuration-directory} (default: @code{%default-auditd-configuration-directory})
29944 The directory containing the configuration file for the audit package, which
29945 must be named @code{auditd.conf}, and optionally some audit rules to
29946 instantiate on startup.
29952 @subsubheading R-Shiny service
29954 The @code{(gnu services science)} module provides the following service.
29956 @defvr {Scheme Variable} rshiny-service-type
29958 This is a type of service which is used to run a webapp created with
29959 @code{r-shiny}. This service sets the @env{R_LIBS_USER} environment
29960 variable and runs the provided script to call @code{runApp}.
29962 @deftp {Data Type} rshiny-configuration
29963 This is the data type representing the configuration of rshiny.
29967 @item @code{package} (default: @code{r-shiny})
29968 The package to use.
29970 @item @code{binary} (defaunlt @code{"rshiny"})
29971 The name of the binary or shell script located at @code{package/bin/} to
29972 run when the service is run.
29974 The common way to create this file is as follows:
29978 (let* ((out (assoc-ref %outputs "out"))
29979 (targetdir (string-append out "/share/" ,name))
29980 (app (string-append out "/bin/" ,name))
29981 (Rbin (string-append (assoc-ref %build-inputs "r-min")
29984 (mkdir-p (string-append out "/bin"))
29985 (call-with-output-file app
29991 runApp(launch.browser=0, port=4202)~%\n"
30000 @subsubheading Nix service
30002 The @code{(gnu services nix)} module provides the following service.
30004 @defvr {Scheme Variable} nix-service-type
30006 This is the type of the service that runs build daemon of the
30007 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
30011 (use-modules (gnu))
30012 (use-service-modules nix)
30013 (use-package-modules package-management)
30017 (packages (append (list nix)
30020 (services (append (list (service nix-service-type))
30024 After @command{guix system reconfigure} configure Nix for your user:
30027 @item Add a Nix channel and update it. See
30028 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
30030 @item Create a symlink to your profile and activate Nix profile:
30034 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
30035 $ source /run/current-system/profile/etc/profile.d/nix.sh
30040 @deftp {Data Type} nix-configuration
30041 This data type represents the configuration of the Nix daemon.
30044 @item @code{nix} (default: @code{nix})
30045 The Nix package to use.
30047 @item @code{sandbox} (default: @code{#t})
30048 Specifies whether builds are sandboxed by default.
30050 @item @code{build-sandbox-items} (default: @code{'()})
30051 This is a list of strings or objects appended to the
30052 @code{build-sandbox-items} field of the configuration file.
30054 @item @code{extra-config} (default: @code{'()})
30055 This is a list of strings or objects appended to the configuration file.
30056 It is used to pass extra text to be added verbatim to the configuration
30059 @item @code{extra-options} (default: @code{'()})
30060 Extra command line options for @code{nix-service-type}.
30064 @node Setuid Programs
30065 @section Setuid Programs
30067 @cindex setuid programs
30068 Some programs need to run with ``root'' privileges, even when they are
30069 launched by unprivileged users. A notorious example is the
30070 @command{passwd} program, which users can run to change their
30071 password, and which needs to access the @file{/etc/passwd} and
30072 @file{/etc/shadow} files---something normally restricted to root, for
30073 obvious security reasons. To address that, these executables are
30074 @dfn{setuid-root}, meaning that they always run with root privileges
30075 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
30076 for more info about the setuid mechanism).
30078 The store itself @emph{cannot} contain setuid programs: that would be a
30079 security issue since any user on the system can write derivations that
30080 populate the store (@pxref{The Store}). Thus, a different mechanism is
30081 used: instead of changing the setuid bit directly on files that are in
30082 the store, we let the system administrator @emph{declare} which programs
30083 should be setuid root.
30085 The @code{setuid-programs} field of an @code{operating-system}
30086 declaration contains a list of G-expressions denoting the names of
30087 programs to be setuid-root (@pxref{Using the Configuration System}).
30088 For instance, the @command{passwd} program, which is part of the Shadow
30089 package, can be designated by this G-expression (@pxref{G-Expressions}):
30092 #~(string-append #$shadow "/bin/passwd")
30095 A default set of setuid programs is defined by the
30096 @code{%setuid-programs} variable of the @code{(gnu system)} module.
30098 @defvr {Scheme Variable} %setuid-programs
30099 A list of G-expressions denoting common programs that are setuid-root.
30101 The list includes commands such as @command{passwd}, @command{ping},
30102 @command{su}, and @command{sudo}.
30105 Under the hood, the actual setuid programs are created in the
30106 @file{/run/setuid-programs} directory at system activation time. The
30107 files in this directory refer to the ``real'' binaries, which are in the
30110 @node X.509 Certificates
30111 @section X.509 Certificates
30113 @cindex HTTPS, certificates
30114 @cindex X.509 certificates
30116 Web servers available over HTTPS (that is, HTTP over the transport-layer
30117 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
30118 that the client can then use to @emph{authenticate} the server. To do
30119 that, clients verify that the server's certificate is signed by a
30120 so-called @dfn{certificate authority} (CA). But to verify the CA's
30121 signature, clients must have first acquired the CA's certificate.
30123 Web browsers such as GNU@tie{}IceCat include their own set of CA
30124 certificates, such that they are able to verify CA signatures
30127 However, most other programs that can talk HTTPS---@command{wget},
30128 @command{git}, @command{w3m}, etc.---need to be told where CA
30129 certificates can be found.
30131 @cindex @code{nss-certs}
30132 In Guix, this is done by adding a package that provides certificates
30133 to the @code{packages} field of the @code{operating-system} declaration
30134 (@pxref{operating-system Reference}). Guix includes one such package,
30135 @code{nss-certs}, which is a set of CA certificates provided as part of
30136 Mozilla's Network Security Services.
30138 Note that it is @emph{not} part of @code{%base-packages}, so you need to
30139 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
30140 most applications and libraries look for certificates by default, points
30141 to the certificates installed globally.
30143 Unprivileged users, including users of Guix on a foreign distro,
30144 can also install their own certificate package in
30145 their profile. A number of environment variables need to be defined so
30146 that applications and libraries know where to find them. Namely, the
30147 OpenSSL library honors the @env{SSL_CERT_DIR} and @env{SSL_CERT_FILE}
30148 variables. Some applications add their own environment variables; for
30149 instance, the Git version control system honors the certificate bundle
30150 pointed to by the @env{GIT_SSL_CAINFO} environment variable. Thus, you
30151 would typically run something like:
30154 guix install nss-certs
30155 export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
30156 export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
30157 export GIT_SSL_CAINFO="$SSL_CERT_FILE"
30160 As another example, R requires the @env{CURL_CA_BUNDLE} environment
30161 variable to point to a certificate bundle, so you would have to run
30162 something like this:
30165 guix install nss-certs
30166 export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
30169 For other applications you may want to look up the required environment
30170 variable in the relevant documentation.
30173 @node Name Service Switch
30174 @section Name Service Switch
30176 @cindex name service switch
30178 The @code{(gnu system nss)} module provides bindings to the
30179 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
30180 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
30181 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
30182 extended with new ``name'' lookup methods for system databases, which
30183 includes host names, service names, user accounts, and more (@pxref{Name
30184 Service Switch, System Databases and Name Service Switch,, libc, The GNU
30185 C Library Reference Manual}).
30187 The NSS configuration specifies, for each system database, which lookup
30188 method is to be used, and how the various methods are chained
30189 together---for instance, under which circumstances NSS should try the
30190 next method in the list. The NSS configuration is given in the
30191 @code{name-service-switch} field of @code{operating-system} declarations
30192 (@pxref{operating-system Reference, @code{name-service-switch}}).
30195 @cindex .local, host name lookup
30196 As an example, the declaration below configures the NSS to use the
30197 @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
30198 back-end}, which supports host name lookups over multicast DNS (mDNS)
30199 for host names ending in @code{.local}:
30202 (name-service-switch
30203 (hosts (list %files ;first, check /etc/hosts
30205 ;; If the above did not succeed, try
30206 ;; with 'mdns_minimal'.
30208 (name "mdns_minimal")
30210 ;; 'mdns_minimal' is authoritative for
30211 ;; '.local'. When it returns "not found",
30212 ;; no need to try the next methods.
30213 (reaction (lookup-specification
30214 (not-found => return))))
30216 ;; Then fall back to DNS.
30220 ;; Finally, try with the "full" 'mdns'.
30225 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
30226 contains this configuration, so you will not have to type it if all you
30227 want is to have @code{.local} host lookup working.
30229 Note that, in this case, in addition to setting the
30230 @code{name-service-switch} of the @code{operating-system} declaration,
30231 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
30232 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
30233 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
30234 to the name service cache daemon (@pxref{Base Services,
30235 @code{nscd-service}}).
30237 For convenience, the following variables provide typical NSS
30240 @defvr {Scheme Variable} %default-nss
30241 This is the default name service switch configuration, a
30242 @code{name-service-switch} object.
30245 @defvr {Scheme Variable} %mdns-host-lookup-nss
30246 This is the name service switch configuration with support for host name
30247 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
30250 The reference for name service switch configuration is given below. It
30251 is a direct mapping of the configuration file format of the C library , so
30252 please refer to the C library manual for more information (@pxref{NSS
30253 Configuration File,,, libc, The GNU C Library Reference Manual}).
30254 Compared to the configuration file format of libc NSS, it has the advantage
30255 not only of adding this warm parenthetic feel that we like, but also
30256 static checks: you will know about syntax errors and typos as soon as you
30257 run @command{guix system}.
30259 @deftp {Data Type} name-service-switch
30261 This is the data type representation the configuration of libc's name
30262 service switch (NSS). Each field below represents one of the supported
30279 The system databases handled by the NSS. Each of these fields must be a
30280 list of @code{<name-service>} objects (see below).
30284 @deftp {Data Type} name-service
30286 This is the data type representing an actual name service and the
30287 associated lookup action.
30291 A string denoting the name service (@pxref{Services in the NSS
30292 configuration,,, libc, The GNU C Library Reference Manual}).
30294 Note that name services listed here must be visible to nscd. This is
30295 achieved by passing the @code{#:name-services} argument to
30296 @code{nscd-service} the list of packages providing the needed name
30297 services (@pxref{Base Services, @code{nscd-service}}).
30300 An action specified using the @code{lookup-specification} macro
30301 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
30302 Reference Manual}). For example:
30305 (lookup-specification (unavailable => continue)
30306 (success => return))
30311 @node Initial RAM Disk
30312 @section Initial RAM Disk
30315 @cindex initial RAM disk
30316 For bootstrapping purposes, the Linux-Libre kernel is passed an
30317 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
30318 root file system as well as an initialization script. The latter is
30319 responsible for mounting the real root file system, and for loading any
30320 kernel modules that may be needed to achieve that.
30322 The @code{initrd-modules} field of an @code{operating-system}
30323 declaration allows you to specify Linux-libre kernel modules that must
30324 be available in the initrd. In particular, this is where you would list
30325 modules needed to actually drive the hard disk where your root partition
30326 is---although the default value of @code{initrd-modules} should cover
30327 most use cases. For example, assuming you need the @code{megaraid_sas}
30328 module in addition to the default modules to be able to access your root
30329 file system, you would write:
30334 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
30337 @defvr {Scheme Variable} %base-initrd-modules
30338 This is the list of kernel modules included in the initrd by default.
30341 Furthermore, if you need lower-level customization, the @code{initrd}
30342 field of an @code{operating-system} declaration allows
30343 you to specify which initrd you would like to use. The @code{(gnu
30344 system linux-initrd)} module provides three ways to build an initrd: the
30345 high-level @code{base-initrd} procedure and the low-level
30346 @code{raw-initrd} and @code{expression->initrd} procedures.
30348 The @code{base-initrd} procedure is intended to cover most common uses.
30349 For example, if you want to add a bunch of kernel modules to be loaded
30350 at boot time, you can define the @code{initrd} field of the operating
30351 system declaration like this:
30354 (initrd (lambda (file-systems . rest)
30355 ;; Create a standard initrd but set up networking
30356 ;; with the parameters QEMU expects by default.
30357 (apply base-initrd file-systems
30358 #:qemu-networking? #t
30362 The @code{base-initrd} procedure also handles common use cases that
30363 involves using the system as a QEMU guest, or as a ``live'' system with
30364 volatile root file system.
30366 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
30367 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
30368 such as trying to guess which kernel modules and packages should be included
30369 to the initrd. An example use of @code{raw-initrd} is when a user has
30370 a custom Linux kernel configuration and default kernel modules included by
30371 @code{base-initrd} are not available.
30373 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
30374 honors several options passed on the Linux kernel command line
30375 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
30376 @code{-append} option of QEMU), notably:
30379 @item --load=@var{boot}
30380 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
30381 program, once it has mounted the root file system.
30383 Guix uses this option to yield control to a boot program that runs the
30384 service activation programs and then spawns the GNU@tie{}Shepherd, the
30385 initialization system.
30387 @item --root=@var{root}
30388 Mount @var{root} as the root file system. @var{root} can be a device
30389 name like @code{/dev/sda1}, a file system label, or a file system UUID.
30390 When unspecified, the device name from the root file system of the
30391 operating system declaration is used.
30393 @item --system=@var{system}
30394 Have @file{/run/booted-system} and @file{/run/current-system} point to
30397 @item modprobe.blacklist=@var{modules}@dots{}
30398 @cindex module, black-listing
30399 @cindex black list, of kernel modules
30400 Instruct the initial RAM disk as well as the @command{modprobe} command
30401 (from the kmod package) to refuse to load @var{modules}. @var{modules}
30402 must be a comma-separated list of module names---e.g.,
30403 @code{usbkbd,9pnet}.
30406 Start a read-eval-print loop (REPL) from the initial RAM disk before it
30407 tries to load kernel modules and to mount the root file system. Our
30408 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
30409 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
30410 Manual}, for more information on Guile's REPL.
30414 Now that you know all the features that initial RAM disks produced by
30415 @code{base-initrd} and @code{raw-initrd} provide,
30416 here is how to use it and customize it further.
30419 @cindex initial RAM disk
30420 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
30421 [#:linux-modules '()] [#:mapped-devices '()] @
30422 [#:keyboard-layout #f] @
30423 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
30424 Return a derivation that builds a raw initrd. @var{file-systems} is
30425 a list of file systems to be mounted by the initrd, possibly in addition to
30426 the root file system specified on the kernel command line via @option{--root}.
30427 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
30428 @var{mapped-devices} is a list of device mappings to realize before
30429 @var{file-systems} are mounted (@pxref{Mapped Devices}).
30430 @var{helper-packages} is a list of packages to be copied in the initrd. It may
30431 include @code{e2fsck/static} or other packages needed by the initrd to check
30432 the root file system.
30434 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
30435 the desired console keyboard layout. This is done before @var{mapped-devices}
30436 are set up and before @var{file-systems} are mounted such that, should the
30437 user need to enter a passphrase or use the REPL, this happens using the
30438 intended keyboard layout.
30440 When @var{qemu-networking?} is true, set up networking with the standard QEMU
30441 parameters. When @var{virtio?} is true, load additional modules so that the
30442 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
30444 When @var{volatile-root?} is true, the root file system is writable but any changes
30448 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
30449 [#:mapped-devices '()] [#:keyboard-layout #f] @
30450 [#:qemu-networking? #f] [#:volatile-root? #f] @
30451 [#:linux-modules '()]
30452 Return as a file-like object a generic initrd, with kernel
30453 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
30454 mounted by the initrd, possibly in addition to the root file system specified
30455 on the kernel command line via @option{--root}. @var{mapped-devices} is a list of device
30456 mappings to realize before @var{file-systems} are mounted.
30458 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
30459 the desired console keyboard layout. This is done before @var{mapped-devices}
30460 are set up and before @var{file-systems} are mounted such that, should the
30461 user need to enter a passphrase or use the REPL, this happens using the
30462 intended keyboard layout.
30464 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
30466 The initrd is automatically populated with all the kernel modules necessary
30467 for @var{file-systems} and for the given options. Additional kernel
30468 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
30469 loaded at boot time in the order in which they appear.
30472 Needless to say, the initrds we produce and use embed a
30473 statically-linked Guile, and the initialization program is a Guile
30474 program. That gives a lot of flexibility. The
30475 @code{expression->initrd} procedure builds such an initrd, given the
30476 program to run in that initrd.
30478 @deffn {Scheme Procedure} expression->initrd @var{exp} @
30479 [#:guile %guile-3.0-static-stripped] [#:name "guile-initrd"]
30480 Return as a file-like object a Linux initrd (a gzipped cpio archive)
30481 containing @var{guile} and that evaluates @var{exp}, a G-expression,
30482 upon booting. All the derivations referenced by @var{exp} are
30483 automatically copied to the initrd.
30486 @node Bootloader Configuration
30487 @section Bootloader Configuration
30490 @cindex boot loader
30492 The operating system supports multiple bootloaders. The bootloader is
30493 configured using @code{bootloader-configuration} declaration. All the
30494 fields of this structure are bootloader agnostic except for one field,
30495 @code{bootloader} that indicates the bootloader to be configured and
30498 Some of the bootloaders do not honor every field of
30499 @code{bootloader-configuration}. For instance, the extlinux
30500 bootloader does not support themes and thus ignores the @code{theme}
30503 @deftp {Data Type} bootloader-configuration
30504 The type of a bootloader configuration declaration.
30508 @item @code{bootloader}
30509 @cindex EFI, bootloader
30510 @cindex UEFI, bootloader
30511 @cindex BIOS, bootloader
30512 The bootloader to use, as a @code{bootloader} object. For now
30513 @code{grub-bootloader}, @code{grub-efi-bootloader},
30514 @code{grub-efi-netboot-bootloader}, @code{extlinux-bootloader} and
30515 @code{u-boot-bootloader} are supported.
30517 @cindex ARM, bootloaders
30518 @cindex AArch64, bootloaders
30519 Available bootloaders are described in @code{(gnu bootloader @dots{})}
30520 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
30521 of bootloaders for a wide range of ARM and AArch64 systems, using the
30522 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
30524 @vindex grub-efi-bootloader
30525 @code{grub-efi-bootloader} allows to boot on modern systems using the
30526 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
30527 use if the installation image contains a @file{/sys/firmware/efi} directory
30528 when you boot it on your system.
30530 @vindex grub-bootloader
30531 @code{grub-bootloader} allows you to boot in particular Intel-based machines
30532 in ``legacy'' BIOS mode.
30534 @vindex grub-efi-netboot-bootloader
30535 @code{grub-efi-netboot-bootloader} allows you to boot your system over network
30536 through TFTP. In combination with an NFS root file system this allows you to
30537 build a diskless Guix system.
30539 The installation of the @code{grub-efi-netboot-bootloader} generates the content
30540 of the TFTP root directory at @code{target}
30541 (@pxref{Bootloader Configuration, @code{target}}), to be served by a TFTP server.
30542 You may want to mount your TFTP server directory onto @code{target} to move the
30543 required files to the TFTP server automatically.
30545 If you plan to use an NFS root file system as well (actually if you mount the
30546 store from an NFS share), then the TFTP server needs to serve the file
30547 @file{/boot/grub/grub.cfg} and other files from the store (like GRUBs background
30548 image, the kernel (@pxref{operating-system Reference, @code{kernel}}) and the
30549 initrd (@pxref{operating-system Reference, @code{initrd}})), too. All these
30550 files from the store will be accessed by GRUB through TFTP with their normal
30551 store path, for example as
30552 @file{tftp://tftp-server/gnu/store/…-initrd/initrd.cpio.gz}.
30554 Two symlinks are created to make this possible. The first symlink is
30555 @code{target}@file{/efi/Guix/boot/grub/grub.cfg} pointing to
30556 @file{../../../boot/grub/grub.cfg},
30557 where @code{target} may be @file{/boot}. In this case the link is not leaving
30558 the served TFTP root directory, but otherwise it does. The second link is
30559 @code{target}@file{/gnu/store} and points to @file{../gnu/store}. This link
30560 is leaving the served TFTP root directory.
30562 The assumption behind all this is that you have an NFS server exporting the root
30563 file system for your Guix system, and additionally a TFTP server exporting your
30564 @code{target} directory—usually @file{/boot}—from that same root file system for
30565 your Guix system. In this constellation the symlinks will work.
30567 For other constellations you will have to program your own bootloader installer,
30568 which then takes care to make necessary files from the store accessible through
30569 TFTP, for example by copying them into the TFTP root directory at @code{target}.
30571 It is important to note that symlinks pointing outside the TFTP root directory
30572 may need to be allowed in the configuration of your TFTP server. Further the
30573 store link exposes the whole store through TFTP. Both points need to be
30574 considered carefully for security aspects.
30576 Beside the @code{grub-efi-netboot-bootloader}, the already mentioned TFTP and
30577 NFS servers, you also need a properly configured DHCP server to make the booting
30578 over netboot possible. For all this we can currently only recommend you to look
30579 for instructions about @acronym{PXE, Preboot eXecution Environment}.
30581 @item @code{target}
30582 This is a string denoting the target onto which to install the
30585 The interpretation depends on the bootloader in question. For
30586 @code{grub-bootloader}, for example, it should be a device name understood by
30587 the bootloader @command{installer} command, such as @code{/dev/sda} or
30588 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
30589 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
30590 system, usually @file{/boot/efi}. For @code{grub-efi-netboot-bootloader},
30591 @code{target} should be the mount point corresponding to the TFTP root
30592 directory of your TFTP server.
30594 @item @code{menu-entries} (default: @code{()})
30595 A possibly empty list of @code{menu-entry} objects (see below), denoting
30596 entries to appear in the bootloader menu, in addition to the current
30597 system entry and the entry pointing to previous system generations.
30599 @item @code{default-entry} (default: @code{0})
30600 The index of the default boot menu entry. Index 0 is for the entry of the
30603 @item @code{timeout} (default: @code{5})
30604 The number of seconds to wait for keyboard input before booting. Set to
30605 0 to boot immediately, and to -1 to wait indefinitely.
30607 @cindex keyboard layout, for the bootloader
30608 @item @code{keyboard-layout} (default: @code{#f})
30609 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
30610 layout, usually US@tie{}English (``qwerty'').
30612 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
30616 This option is currently ignored by bootloaders other than @code{grub} and
30620 @item @code{theme} (default: @var{#f})
30621 The bootloader theme object describing the theme to use. If no theme
30622 is provided, some bootloaders might use a default theme, that's true
30625 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
30626 The output terminals used for the bootloader boot menu, as a list of
30627 symbols. GRUB accepts the values: @code{console}, @code{serial},
30628 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
30629 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
30630 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
30631 configuration,,, grub,GNU GRUB manual}).
30633 @item @code{terminal-inputs} (default: @code{'()})
30634 The input terminals used for the bootloader boot menu, as a list of
30635 symbols. For GRUB, the default is the native platform terminal as
30636 determined at run-time. GRUB accepts the values: @code{console},
30637 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
30638 @code{usb_keyboard}. This field corresponds to the GRUB variable
30639 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
30642 @item @code{serial-unit} (default: @code{#f})
30643 The serial unit used by the bootloader, as an integer from 0 to 3.
30644 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
30645 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
30647 @item @code{serial-speed} (default: @code{#f})
30648 The speed of the serial interface, as an integer. For GRUB, the
30649 default value is chosen at run-time; currently GRUB chooses
30650 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
30657 Should you want to list additional boot menu entries @i{via} the
30658 @code{menu-entries} field above, you will need to create them with the
30659 @code{menu-entry} form. For example, imagine you want to be able to
30660 boot another distro (hard to imagine!), you can define a menu entry
30665 (label "The Other Distro")
30666 (linux "/boot/old/vmlinux-2.6.32")
30667 (linux-arguments '("root=/dev/sda2"))
30668 (initrd "/boot/old/initrd"))
30673 @deftp {Data Type} menu-entry
30674 The type of an entry in the bootloader menu.
30679 The label to show in the menu---e.g., @code{"GNU"}.
30681 @item @code{linux} (default: @code{#f})
30682 The Linux kernel image to boot, for example:
30685 (file-append linux-libre "/bzImage")
30688 For GRUB, it is also possible to specify a device explicitly in the
30689 file path using GRUB's device naming convention (@pxref{Naming
30690 convention,,, grub, GNU GRUB manual}), for example:
30693 "(hd0,msdos1)/boot/vmlinuz"
30696 If the device is specified explicitly as above, then the @code{device}
30697 field is ignored entirely.
30699 @item @code{linux-arguments} (default: @code{()})
30700 The list of extra Linux kernel command-line arguments---e.g.,
30701 @code{("console=ttyS0")}.
30703 @item @code{initrd} (default: @code{#f})
30704 A G-Expression or string denoting the file name of the initial RAM disk
30705 to use (@pxref{G-Expressions}).
30707 @item @code{device} (default: @code{#f})
30708 The device where the kernel and initrd are to be found---i.e., for GRUB,
30709 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
30711 This may be a file system label (a string), a file system UUID (a
30712 bytevector, @pxref{File Systems}), or @code{#f}, in which case
30713 the bootloader will search the device containing the file specified by
30714 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
30715 must @emph{not} be an OS device name such as @file{/dev/sda1}.
30717 @item @code{multiboot-kernel} (default: @code{#f})
30718 The kernel to boot in Multiboot-mode (@pxref{multiboot,,, grub, GNU GRUB
30719 manual}). When this field is set, a Multiboot menu-entry is generated.
30723 (file-append mach "/boot/gnumach")
30726 @item @code{multiboot-arguments} (default: @code{()})
30727 The list of extra command-line arguments for the multiboot-kernel.
30729 @item @code{multiboot-modules} (default: @code{()})
30730 The list of commands for loading Multiboot modules. For example:
30733 (list (list (file-append hurd "/hurd/ext2fs.static") "ext2fs"
30735 (list (file-append libc "/lib/ld.so.1") "exec"
30745 @c FIXME: Write documentation once it's stable.
30746 For now only GRUB has theme support. GRUB themes are created using
30747 the @code{grub-theme} form, which is not fully documented yet.
30749 @deftp {Data Type} grub-theme
30750 Data type representing the configuration of the GRUB theme.
30753 @item @code{gfxmode} (default: @code{'("auto")})
30754 The GRUB @code{gfxmode} to set (a list of screen resolution strings,
30755 @pxref{gfxmode,,, grub, GNU GRUB manual}).
30759 @deffn {Scheme Procedure} grub-theme
30760 Return the default GRUB theme used by the operating system if no
30761 @code{theme} field is specified in @code{bootloader-configuration}
30764 It comes with a fancy background image displaying the GNU and Guix
30768 For example, to override the default resolution, you may use something
30773 (bootloader-configuration
30776 (inherit (grub-theme))
30777 (gfxmode '("1024x786x32" "auto"))))))
30780 @node Invoking guix system
30781 @section Invoking @code{guix system}
30783 Once you have written an operating system declaration as seen in the
30784 previous section, it can be @dfn{instantiated} using the @command{guix
30785 system} command. The synopsis is:
30788 guix system @var{options}@dots{} @var{action} @var{file}
30791 @var{file} must be the name of a file containing an
30792 @code{operating-system} declaration. @var{action} specifies how the
30793 operating system is instantiated. Currently the following values are
30798 Display available service type definitions that match the given regular
30799 expressions, sorted by relevance:
30805 $ guix system search console
30806 name: console-fonts
30807 location: gnu/services/base.scm:806:2
30808 extends: shepherd-root
30809 description: Install the given fonts on the specified ttys (fonts are per
30810 + virtual console on GNU/Linux). The value of this service is a list of
30811 + tty/font pairs. The font can be the name of a font provided by the `kbd'
30812 + package or any valid argument to `setfont', as in this example:
30814 + '(("tty1" . "LatGrkCyr-8x16")
30815 + ("tty2" . (file-append
30817 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
30818 + ("tty3" . (file-append
30820 + "/share/consolefonts/ter-132n"))) ; for HDPI
30824 location: gnu/services/base.scm:1190:2
30825 extends: shepherd-root
30826 description: Provide console login using the `mingetty' program.
30830 location: gnu/services/base.scm:860:2
30832 description: Provide a console log-in service as specified by its
30833 + configuration value, a `login-configuration' object.
30839 As for @command{guix package --search}, the result is written in
30840 @code{recutils} format, which makes it easy to filter the output
30841 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
30844 Build the operating system described in @var{file}, activate it, and
30845 switch to it@footnote{This action (and the related actions
30846 @code{switch-generation} and @code{roll-back}) are usable only on
30847 systems already running Guix System.}.
30850 @c The paragraph below refers to the problem discussed at
30851 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
30852 It is highly recommended to run @command{guix pull} once before you run
30853 @command{guix system reconfigure} for the first time (@pxref{Invoking
30854 guix pull}). Failing to do that you would see an older version of Guix
30855 once @command{reconfigure} has completed.
30858 This effects all the configuration specified in @var{file}: user
30859 accounts, system services, global package list, setuid programs, etc.
30860 The command starts system services specified in @var{file} that are not
30861 currently running; if a service is currently running this command will
30862 arrange for it to be upgraded the next time it is stopped (e.g.@: by
30863 @code{herd stop X} or @code{herd restart X}).
30865 This command creates a new generation whose number is one greater than
30866 the current generation (as reported by @command{guix system
30867 list-generations}). If that generation already exists, it will be
30868 overwritten. This behavior mirrors that of @command{guix package}
30869 (@pxref{Invoking guix package}).
30871 It also adds a bootloader menu entry for the new OS configuration,
30872 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
30873 entries for older configurations to a submenu, allowing you to choose
30874 an older system generation at boot time should you need it.
30876 @cindex provenance tracking, of the operating system
30877 Upon completion, the new system is deployed under
30878 @file{/run/current-system}. This directory contains @dfn{provenance
30879 meta-data}: the list of channels in use (@pxref{Channels}) and
30880 @var{file} itself, when available. You can view it by running:
30883 guix system describe
30886 This information is useful should you later want to inspect how this
30887 particular generation was built. In fact, assuming @var{file} is
30888 self-contained, you can later rebuild generation @var{n} of your
30889 operating system with:
30892 guix time-machine \
30893 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
30894 system reconfigure \
30895 /var/guix/profiles/system-@var{n}-link/configuration.scm
30898 You can think of it as some sort of built-in version control! Your
30899 system is not just a binary artifact: @emph{it carries its own source}.
30900 @xref{Service Reference, @code{provenance-service-type}}, for more
30901 information on provenance tracking.
30903 By default, @command{reconfigure} @emph{prevents you from downgrading
30904 your system}, which could (re)introduce security vulnerabilities and
30905 also cause problems with ``stateful'' services such as database
30906 management systems. You can override that behavior by passing
30907 @option{--allow-downgrades}.
30909 @item switch-generation
30910 @cindex generations
30911 Switch to an existing system generation. This action atomically
30912 switches the system profile to the specified system generation. It
30913 also rearranges the system's existing bootloader menu entries. It
30914 makes the menu entry for the specified system generation the default,
30915 and it moves the entries for the other generations to a submenu, if
30916 supported by the bootloader being used. The next time the system
30917 boots, it will use the specified system generation.
30919 The bootloader itself is not being reinstalled when using this
30920 command. Thus, the installed bootloader is used with an updated
30921 configuration file.
30923 The target generation can be specified explicitly by its generation
30924 number. For example, the following invocation would switch to system
30928 guix system switch-generation 7
30931 The target generation can also be specified relative to the current
30932 generation with the form @code{+N} or @code{-N}, where @code{+3} means
30933 ``3 generations ahead of the current generation,'' and @code{-1} means
30934 ``1 generation prior to the current generation.'' When specifying a
30935 negative value such as @code{-1}, you must precede it with @code{--} to
30936 prevent it from being parsed as an option. For example:
30939 guix system switch-generation -- -1
30942 Currently, the effect of invoking this action is @emph{only} to switch
30943 the system profile to an existing generation and rearrange the
30944 bootloader menu entries. To actually start using the target system
30945 generation, you must reboot after running this action. In the future,
30946 it will be updated to do the same things as @command{reconfigure},
30947 like activating and deactivating services.
30949 This action will fail if the specified generation does not exist.
30952 @cindex rolling back
30953 Switch to the preceding system generation. The next time the system
30954 boots, it will use the preceding system generation. This is the inverse
30955 of @command{reconfigure}, and it is exactly the same as invoking
30956 @command{switch-generation} with an argument of @code{-1}.
30958 Currently, as with @command{switch-generation}, you must reboot after
30959 running this action to actually start using the preceding system
30962 @item delete-generations
30963 @cindex deleting system generations
30964 @cindex saving space
30965 Delete system generations, making them candidates for garbage collection
30966 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
30969 This works in the same way as @samp{guix package --delete-generations}
30970 (@pxref{Invoking guix package, @option{--delete-generations}}). With no
30971 arguments, all system generations but the current one are deleted:
30974 guix system delete-generations
30977 You can also select the generations you want to delete. The example below
30978 deletes all the system generations that are more than two month old:
30981 guix system delete-generations 2m
30984 Running this command automatically reinstalls the bootloader with an updated
30985 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
30986 longer lists the generations that have been deleted.
30989 Build the derivation of the operating system, which includes all the
30990 configuration files and programs needed to boot and run the system.
30991 This action does not actually install anything.
30994 Populate the given directory with all the files necessary to run the
30995 operating system specified in @var{file}. This is useful for first-time
30996 installations of Guix System. For instance:
30999 guix system init my-os-config.scm /mnt
31002 copies to @file{/mnt} all the store items required by the configuration
31003 specified in @file{my-os-config.scm}. This includes configuration
31004 files, packages, and so on. It also creates other essential files
31005 needed for the system to operate correctly---e.g., the @file{/etc},
31006 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
31008 This command also installs bootloader on the target specified in
31009 @file{my-os-config}, unless the @option{--no-bootloader} option was
31013 @cindex virtual machine
31015 @anchor{guix system vm}
31016 Build a virtual machine that contains the operating system declared in
31017 @var{file}, and return a script to run that virtual machine (VM).
31020 The @code{vm} action and others below
31021 can use KVM support in the Linux-libre kernel. Specifically, if the
31022 machine has hardware virtualization support, the corresponding
31023 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
31024 must exist and be readable and writable by the user and by the
31025 build users of the daemon (@pxref{Build Environment Setup}).
31028 Arguments given to the script are passed to QEMU as in the example
31029 below, which enables networking and requests 1@tie{}GiB of RAM for the
31033 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
31036 The VM shares its store with the host system.
31038 Additional file systems can be shared between the host and the VM using
31039 the @option{--share} and @option{--expose} command-line options: the former
31040 specifies a directory to be shared with write access, while the latter
31041 provides read-only access to the shared directory.
31043 The example below creates a VM in which the user's home directory is
31044 accessible read-only, and where the @file{/exchange} directory is a
31045 read-write mapping of @file{$HOME/tmp} on the host:
31048 guix system vm my-config.scm \
31049 --expose=$HOME --share=$HOME/tmp=/exchange
31052 On GNU/Linux, the default is to boot directly to the kernel; this has
31053 the advantage of requiring only a very tiny root disk image since the
31054 store of the host can then be mounted.
31056 The @option{--full-boot} option forces a complete boot sequence, starting
31057 with the bootloader. This requires more disk space since a root image
31058 containing at least the kernel, initrd, and bootloader data files must
31059 be created. The @option{--image-size} option can be used to specify the
31062 @cindex System images, creation in various formats
31063 @cindex Creating system images in various formats
31066 @itemx docker-image
31067 Return a virtual machine, disk image, or Docker image of the operating
31068 system declared in @var{file} that stands alone. By default,
31069 @command{guix system} estimates the size of the image needed to store
31070 the system, but you can use the @option{--image-size} option to specify
31071 a value. Docker images are built to contain exactly what they need, so
31072 the @option{--image-size} option is ignored in the case of
31073 @code{docker-image}.
31075 @cindex disk-image, creating disk images
31076 The @code{disk-image} command can produce various image types. The
31077 image type can be selected using the @option{--image-type} option. It
31078 defaults to @code{raw}. When its value is @code{iso9660}, the
31079 @option{--label} option can be used to specify a volume ID with
31080 @code{disk-image}. By default, the root file system of a disk image is
31081 mounted non-volatile; the @option{--volatile} option can be provided to
31082 make it volatile instead. When using @code{disk-image}, the bootloader
31083 installed on the generated image is taken from the provided
31084 @code{operating-system} definition. The following example demonstrates
31085 how to generate an image that uses the @code{grub-efi-bootloader}
31086 bootloader and boot it with QEMU:
31089 image=$(guix system disk-image --image-type=qcow2 \
31090 gnu/system/examples/lightweight-desktop.tmpl)
31091 cp $image /tmp/my-image.qcow2
31092 chmod +w /tmp/my-image.qcow2
31093 qemu-system-x86_64 -enable-kvm -hda /tmp/my-image.qcow2 -m 1000 \
31094 -bios $(guix build ovmf)/share/firmware/ovmf_x64.bin
31097 When using the @code{raw} image type, a raw disk image is produced; it
31098 can be copied as is to a USB stick, for instance. Assuming
31099 @code{/dev/sdc} is the device corresponding to a USB stick, one can copy
31100 the image to it using the following command:
31103 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc status=progress
31106 The @code{--list-image-types} command lists all the available image
31109 @cindex vm-image, creating virtual machine images
31110 When using @code{vm-image}, the returned image is in qcow2 format, which
31111 the QEMU emulator can efficiently use. @xref{Running Guix in a VM}, for
31112 more information on how to run the image in a virtual machine. The
31113 @code{grub-bootloader} bootloader is always used independently of what
31114 is declared in the @code{operating-system} file passed as argument.
31115 This is to make it easier to work with QEMU, which uses the SeaBIOS BIOS
31116 by default, expecting a bootloader to be installed in the Master Boot
31119 @cindex docker-image, creating docker images
31120 When using @code{docker-image}, a Docker image is produced. Guix builds
31121 the image from scratch, not from a pre-existing Docker base image. As a
31122 result, it contains @emph{exactly} what you define in the operating
31123 system configuration file. You can then load the image and launch a
31124 Docker container using commands like the following:
31127 image_id="`docker load < guix-system-docker-image.tar.gz`"
31128 container_id="`docker create $image_id`"
31129 docker start $container_id
31132 This command starts a new Docker container from the specified image. It
31133 will boot the Guix system in the usual manner, which means it will
31134 start any services you have defined in the operating system
31135 configuration. You can get an interactive shell running in the container
31136 using @command{docker exec}:
31139 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
31142 Depending on what you run in the Docker container, it
31143 may be necessary to give the container additional permissions. For
31144 example, if you intend to build software using Guix inside of the Docker
31145 container, you may need to pass the @option{--privileged} option to
31146 @code{docker create}.
31148 Last, the @option{--network} option applies to @command{guix system
31149 docker-image}: it produces an image where network is supposedly shared
31150 with the host, and thus without services like nscd or NetworkManager.
31153 Return a script to run the operating system declared in @var{file}
31154 within a container. Containers are a set of lightweight isolation
31155 mechanisms provided by the kernel Linux-libre. Containers are
31156 substantially less resource-demanding than full virtual machines since
31157 the kernel, shared objects, and other resources can be shared with the
31158 host system; this also means they provide thinner isolation.
31160 Currently, the script must be run as root in order to support more than
31161 a single user and group. The container shares its store with the host
31164 As with the @code{vm} action (@pxref{guix system vm}), additional file
31165 systems to be shared between the host and container can be specified
31166 using the @option{--share} and @option{--expose} options:
31169 guix system container my-config.scm \
31170 --expose=$HOME --share=$HOME/tmp=/exchange
31174 This option requires Linux-libre 3.19 or newer.
31179 @var{options} can contain any of the common build options (@pxref{Common
31180 Build Options}). In addition, @var{options} can contain one of the
31184 @item --expression=@var{expr}
31185 @itemx -e @var{expr}
31186 Consider the operating-system @var{expr} evaluates to.
31187 This is an alternative to specifying a file which evaluates to an
31189 This is used to generate the Guix system installer @pxref{Building the
31190 Installation Image}).
31192 @item --system=@var{system}
31193 @itemx -s @var{system}
31194 Attempt to build for @var{system} instead of the host system type.
31195 This works as per @command{guix build} (@pxref{Invoking guix build}).
31199 Return the derivation file name of the given operating system without
31202 @cindex provenance tracking, of the operating system
31203 @item --save-provenance
31204 As discussed above, @command{guix system init} and @command{guix system
31205 reconfigure} always save provenance information @i{via} a dedicated
31206 service (@pxref{Service Reference, @code{provenance-service-type}}).
31207 However, other commands don't do that by default. If you wish to, say,
31208 create a virtual machine image that contains provenance information, you
31212 guix system vm-image --save-provenance config.scm
31215 That way, the resulting image will effectively ``embed its own source''
31216 in the form of meta-data in @file{/run/current-system}. With that
31217 information, one can rebuild the image to make sure it really contains
31218 what it pretends to contain; or they could use that to derive a variant
31221 @item --image-type=@var{type}
31222 @itemx -t @var{type}
31223 For the @code{disk-image} action, create an image with given @var{type}.
31225 When this option is omitted, @command{guix system} uses the @code{raw}
31228 @cindex ISO-9660 format
31229 @cindex CD image format
31230 @cindex DVD image format
31231 @option{--image-type=iso9660} produces an ISO-9660 image, suitable
31232 for burning on CDs and DVDs.
31234 @item --image-size=@var{size}
31235 For the @code{vm-image} and @code{disk-image} actions, create an image
31236 of the given @var{size}. @var{size} may be a number of bytes, or it may
31237 include a unit as a suffix (@pxref{Block size, size specifications,,
31238 coreutils, GNU Coreutils}).
31240 When this option is omitted, @command{guix system} computes an estimate
31241 of the image size as a function of the size of the system declared in
31246 For the @code{container} action, allow containers to access the host network,
31247 that is, do not create a network namespace.
31249 @item --root=@var{file}
31250 @itemx -r @var{file}
31251 Make @var{file} a symlink to the result, and register it as a garbage
31254 @item --skip-checks
31255 Skip pre-installation safety checks.
31257 By default, @command{guix system init} and @command{guix system
31258 reconfigure} perform safety checks: they make sure the file systems that
31259 appear in the @code{operating-system} declaration actually exist
31260 (@pxref{File Systems}), and that any Linux kernel modules that may be
31261 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
31262 RAM Disk}). Passing this option skips these tests altogether.
31264 @item --allow-downgrades
31265 Instruct @command{guix system reconfigure} to allow system downgrades.
31267 By default, @command{reconfigure} prevents you from downgrading your
31268 system. It achieves that by comparing the provenance info of your
31269 system (shown by @command{guix system describe}) with that of your
31270 @command{guix} command (shown by @command{guix describe}). If the
31271 commits for @command{guix} are not descendants of those used for your
31272 system, @command{guix system reconfigure} errors out. Passing
31273 @option{--allow-downgrades} allows you to bypass these checks.
31276 Make sure you understand its security implications before using
31277 @option{--allow-downgrades}.
31281 @cindex on-error strategy
31282 @cindex error strategy
31283 @item --on-error=@var{strategy}
31284 Apply @var{strategy} when an error occurs when reading @var{file}.
31285 @var{strategy} may be one of the following:
31288 @item nothing-special
31289 Report the error concisely and exit. This is the default strategy.
31292 Likewise, but also display a backtrace.
31295 Report the error and enter Guile's debugger. From there, you can run
31296 commands such as @code{,bt} to get a backtrace, @code{,locals} to
31297 display local variable values, and more generally inspect the state of the
31298 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
31299 a list of available debugging commands.
31303 Once you have built, configured, re-configured, and re-re-configured
31304 your Guix installation, you may find it useful to list the operating
31305 system generations available on disk---and that you can choose from the
31306 bootloader boot menu:
31311 Describe the current system generation: its file name, the kernel and
31312 bootloader used, etc., as well as provenance information when available.
31314 @item list-generations
31315 List a summary of each generation of the operating system available on
31316 disk, in a human-readable way. This is similar to the
31317 @option{--list-generations} option of @command{guix package}
31318 (@pxref{Invoking guix package}).
31320 Optionally, one can specify a pattern, with the same syntax that is used
31321 in @command{guix package --list-generations}, to restrict the list of
31322 generations displayed. For instance, the following command displays
31323 generations that are up to 10 days old:
31326 $ guix system list-generations 10d
31331 The @command{guix system} command has even more to offer! The following
31332 sub-commands allow you to visualize how your system services relate to
31335 @anchor{system-extension-graph}
31338 @item extension-graph
31339 Emit in Dot/Graphviz format to standard output the @dfn{service
31340 extension graph} of the operating system defined in @var{file}
31341 (@pxref{Service Composition}, for more information on service
31347 $ guix system extension-graph @var{file} | xdot -
31350 shows the extension relations among services.
31352 @anchor{system-shepherd-graph}
31353 @item shepherd-graph
31354 Emit in Dot/Graphviz format to standard output the @dfn{dependency
31355 graph} of shepherd services of the operating system defined in
31356 @var{file}. @xref{Shepherd Services}, for more information and for an
31361 @node Invoking guix deploy
31362 @section Invoking @code{guix deploy}
31364 We've already seen @code{operating-system} declarations used to manage a
31365 machine's configuration locally. Suppose you need to configure multiple
31366 machines, though---perhaps you're managing a service on the web that's
31367 comprised of several servers. @command{guix deploy} enables you to use those
31368 same @code{operating-system} declarations to manage multiple remote hosts at
31369 once as a logical ``deployment''.
31372 The functionality described in this section is still under development
31373 and is subject to change. Get in touch with us on
31374 @email{guix-devel@@gnu.org}!
31378 guix deploy @var{file}
31381 Such an invocation will deploy the machines that the code within @var{file}
31382 evaluates to. As an example, @var{file} might contain a definition like this:
31385 ;; This is a Guix deployment of a "bare bones" setup, with
31386 ;; no X11 display server, to a machine with an SSH daemon
31387 ;; listening on localhost:2222. A configuration such as this
31388 ;; may be appropriate for virtual machine with ports
31389 ;; forwarded to the host's loopback interface.
31391 (use-service-modules networking ssh)
31392 (use-package-modules bootloaders)
31396 (host-name "gnu-deployed")
31397 (timezone "Etc/UTC")
31398 (bootloader (bootloader-configuration
31399 (bootloader grub-bootloader)
31400 (target "/dev/vda")
31401 (terminal-outputs '(console))))
31402 (file-systems (cons (file-system
31404 (device "/dev/vda1")
31406 %base-file-systems))
31408 (append (list (service dhcp-client-service-type)
31409 (service openssh-service-type
31410 (openssh-configuration
31411 (permit-root-login #t)
31412 (allow-empty-passwords? #t))))
31416 (operating-system %system)
31417 (environment managed-host-environment-type)
31418 (configuration (machine-ssh-configuration
31419 (host-name "localhost")
31420 (system "x86_64-linux")
31422 (identity "./id_rsa")
31426 The file should evaluate to a list of @var{machine} objects. This example,
31427 upon being deployed, will create a new generation on the remote system
31428 realizing the @code{operating-system} declaration @code{%system}.
31429 @code{environment} and @code{configuration} specify how the machine should be
31430 provisioned---that is, how the computing resources should be created and
31431 managed. The above example does not create any resources, as a
31432 @code{'managed-host} is a machine that is already running the Guix system and
31433 available over the network. This is a particularly simple case; a more
31434 complex deployment may involve, for example, starting virtual machines through
31435 a Virtual Private Server (VPS) provider. In such a case, a different
31436 @var{environment} type would be used.
31438 Do note that you first need to generate a key pair on the coordinator machine
31439 to allow the daemon to export signed archives of files from the store
31440 (@pxref{Invoking guix archive}), though this step is automatic on Guix
31444 # guix archive --generate-key
31448 Each target machine must authorize the key of the master machine so that it
31449 accepts store items it receives from the coordinator:
31452 # guix archive --authorize < coordinator-public-key.txt
31455 @code{user}, in this example, specifies the name of the user account to log in
31456 as to perform the deployment. Its default value is @code{root}, but root
31457 login over SSH may be forbidden in some cases. To work around this,
31458 @command{guix deploy} can log in as an unprivileged user and employ
31459 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
31460 currently installed on the remote and can be invoked non-interactively as
31461 @code{user}. That is, the line in @code{sudoers} granting @code{user} the
31462 ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
31463 be accomplished with the following operating system configuration snippet:
31467 (gnu system)) ;for %sudoers-specification
31469 (define %user "username")
31474 (plain-file "sudoers"
31475 (string-append (plain-file-content %sudoers-specification)
31476 (format #f "~a ALL = NOPASSWD: ALL~%"
31481 For more information regarding the format of the @file{sudoers} file,
31482 consult @command{man sudoers}.
31484 @deftp {Data Type} machine
31485 This is the data type representing a single machine in a heterogeneous Guix
31489 @item @code{operating-system}
31490 The object of the operating system configuration to deploy.
31492 @item @code{environment}
31493 An @code{environment-type} describing how the machine should be provisioned.
31495 @item @code{configuration} (default: @code{#f})
31496 An object describing the configuration for the machine's @code{environment}.
31497 If the @code{environment} has a default configuration, @code{#f} may be used.
31498 If @code{#f} is used for an environment with no default configuration,
31499 however, an error will be thrown.
31503 @deftp {Data Type} machine-ssh-configuration
31504 This is the data type representing the SSH client parameters for a machine
31505 with an @code{environment} of @code{managed-host-environment-type}.
31508 @item @code{host-name}
31509 @item @code{build-locally?} (default: @code{#t})
31510 If false, system derivations will be built on the machine being deployed to.
31511 @item @code{system}
31512 The system type describing the architecture of the machine being deployed
31513 to---e.g., @code{"x86_64-linux"}.
31514 @item @code{authorize?} (default: @code{#t})
31515 If true, the coordinator's signing key will be added to the remote's ACL
31517 @item @code{port} (default: @code{22})
31518 @item @code{user} (default: @code{"root"})
31519 @item @code{identity} (default: @code{#f})
31520 If specified, the path to the SSH private key to use to authenticate with the
31523 @item @code{host-key} (default: @code{#f})
31524 This should be the SSH host key of the machine, which looks like this:
31527 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
31530 When @code{host-key} is @code{#f}, the server is authenticated against
31531 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
31534 @item @code{allow-downgrades?} (default: @code{#f})
31535 Whether to allow potential downgrades.
31537 Like @command{guix system reconfigure}, @command{guix deploy} compares
31538 the channel commits currently deployed on the remote host (as returned
31539 by @command{guix system describe}) to those currently in use (as
31540 returned by @command{guix describe}) to determine whether commits
31541 currently in use are descendants of those deployed. When this is not
31542 the case and @code{allow-downgrades?} is false, it raises an error.
31543 This ensures you do not accidentally downgrade remote machines.
31547 @deftp {Data Type} digital-ocean-configuration
31548 This is the data type describing the Droplet that should be created for a
31549 machine with an @code{environment} of @code{digital-ocean-environment-type}.
31552 @item @code{ssh-key}
31553 The path to the SSH private key to use to authenticate with the remote
31554 host. In the future, this field may not exist.
31556 A list of string ``tags'' that uniquely identify the machine. Must be given
31557 such that no two machines in the deployment have the same set of tags.
31558 @item @code{region}
31559 A Digital Ocean region slug, such as @code{"nyc3"}.
31561 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
31562 @item @code{enable-ipv6?}
31563 Whether or not the droplet should be created with IPv6 networking.
31567 @node Running Guix in a VM
31568 @section Running Guix in a Virtual Machine
31570 @cindex virtual machine
31571 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
31573 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
31574 This image is a compressed image in QCOW format. You will first need to
31575 decompress with @command{xz -d}, and then you can pass it to an emulator such
31576 as QEMU (see below for details).
31578 This image boots the Xfce graphical environment and it contains some
31579 commonly used tools. You can install more software in the image by running
31580 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
31581 also reconfigure the system based on its initial configuration file available
31582 as @file{/run/current-system/configuration.scm} (@pxref{Using the
31583 Configuration System}).
31585 Instead of using this pre-built image, one can also build their own virtual
31586 machine image using @command{guix system vm-image} (@pxref{Invoking guix
31587 system}). The returned image is in qcow2 format, which the
31588 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
31591 If you built your own image, you must copy it out of the store
31592 (@pxref{The Store}) and give yourself permission to write to the copy
31593 before you can use it. When invoking QEMU, you must choose a system
31594 emulator that is suitable for your hardware platform. Here is a minimal
31595 QEMU invocation that will boot the result of @command{guix system
31596 vm-image} on x86_64 hardware:
31599 $ qemu-system-x86_64 \
31600 -nic user,model=virtio-net-pci \
31601 -enable-kvm -m 1024 \
31602 -device virtio-blk,drive=myhd \
31603 -drive if=none,file=/tmp/qemu-image,id=myhd
31606 Here is what each of these options means:
31609 @item qemu-system-x86_64
31610 This specifies the hardware platform to emulate. This should match the
31613 @item -nic user,model=virtio-net-pci
31614 Enable the unprivileged user-mode network stack. The guest OS can
31615 access the host but not vice versa. This is the simplest way to get the
31616 guest OS online. @code{model} specifies which network device to emulate:
31617 @code{virtio-net-pci} is a special device made for virtualized operating
31618 systems and recommended for most uses. Assuming your hardware platform is
31619 x86_64, you can get a list of available NIC models by running
31620 @command{qemu-system-x86_64 -nic model=help}.
31623 If your system has hardware virtualization extensions, enabling the
31624 virtual machine support (KVM) of the Linux kernel will make things run
31627 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
31629 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
31630 which may be insufficient for some operations.
31632 @item -device virtio-blk,drive=myhd
31633 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
31634 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
31635 better performance than if it were emulating a complete disk drive. See the
31636 QEMU and KVM documentation for more info.
31638 @item -drive if=none,file=/tmp/qemu-image,id=myhd
31639 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing
31640 store of the ``myhd'' drive.
31643 The default @command{run-vm.sh} script that is returned by an invocation of
31644 @command{guix system vm} does not add a @command{-nic user} flag by default.
31645 To get network access from within the vm add the @code{(dhcp-client-service)}
31646 to your system definition and start the VM using
31647 @command{`guix system vm config.scm` -nic user}. An important caveat of using
31648 @command{-nic user} for networking is that @command{ping} will not work, because
31649 it uses the ICMP protocol. You'll have to use a different command to check for
31650 network connectivity, for example @command{guix download}.
31652 @subsection Connecting Through SSH
31656 To enable SSH inside a VM you need to add an SSH server like
31657 @code{openssh-service-type} to your VM (@pxref{Networking Services,
31658 @code{openssh-service-type}}). In addition you need to forward the SSH port,
31659 22 by default, to the host. You can do this with
31662 `guix system vm config.scm` -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
31665 To connect to the VM you can run
31668 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
31671 The @command{-p} tells @command{ssh} the port you want to connect to.
31672 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
31673 every time you modify your @command{config.scm} file and the
31674 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
31675 connection to an unknown host every time you connect.
31677 @subsection Using @command{virt-viewer} with Spice
31679 As an alternative to the default @command{qemu} graphical client you can
31680 use the @command{remote-viewer} from the @command{virt-viewer} package. To
31681 connect pass the @command{-spice port=5930,disable-ticketing} flag to
31682 @command{qemu}. See previous section for further information on how to do this.
31684 Spice also allows you to do some nice stuff like share your clipboard with your
31685 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
31688 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
31689 -chardev spicevmc,name=vdagent,id=vdagent
31690 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
31691 name=com.redhat.spice.0
31694 You'll also need to add the @code{(spice-vdagent-service)} to your
31695 system definition (@pxref{Miscellaneous Services, Spice service}).
31697 @node Defining Services
31698 @section Defining Services
31700 The previous sections show the available services and how one can combine
31701 them in an @code{operating-system} declaration. But how do we define
31702 them in the first place? And what is a service anyway?
31705 * Service Composition:: The model for composing services.
31706 * Service Types and Services:: Types and services.
31707 * Service Reference:: API reference.
31708 * Shepherd Services:: A particular type of service.
31711 @node Service Composition
31712 @subsection Service Composition
31716 Here we define a @dfn{service} as, broadly, something that extends the
31717 functionality of the operating system. Often a service is a process---a
31718 @dfn{daemon}---started when the system boots: a secure shell server, a
31719 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
31720 whose execution can be triggered by another daemon---e.g., an FTP server
31721 started by @command{inetd} or a D-Bus service activated by
31722 @command{dbus-daemon}. Occasionally, a service does not map to a
31723 daemon. For instance, the ``account'' service collects user accounts
31724 and makes sure they exist when the system runs; the ``udev'' service
31725 collects device management rules and makes them available to the eudev
31726 daemon; the @file{/etc} service populates the @file{/etc} directory
31729 @cindex service extensions
31730 Guix system services are connected by @dfn{extensions}. For instance, the
31731 secure shell service @emph{extends} the Shepherd---the
31732 initialization system, running as PID@tie{}1---by giving it the command
31733 lines to start and stop the secure shell daemon (@pxref{Networking
31734 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
31735 service by passing it its @file{.service} specification, and extends the
31736 udev service by passing it device management rules (@pxref{Desktop
31737 Services, @code{upower-service}}); the Guix daemon service extends the
31738 Shepherd by passing it the command lines to start and stop the daemon,
31739 and extends the account service by passing it a list of required build
31740 user accounts (@pxref{Base Services}).
31742 All in all, services and their ``extends'' relations form a directed
31743 acyclic graph (DAG). If we represent services as boxes and extensions
31744 as arrows, a typical system might provide something like this:
31746 @image{images/service-graph,,5in,Typical service extension graph.}
31748 @cindex system service
31749 At the bottom, we see the @dfn{system service}, which produces the
31750 directory containing everything to run and boot the system, as returned
31751 by the @command{guix system build} command. @xref{Service Reference},
31752 to learn about the other service types shown here.
31753 @xref{system-extension-graph, the @command{guix system extension-graph}
31754 command}, for information on how to generate this representation for a
31755 particular operating system definition.
31757 @cindex service types
31758 Technically, developers can define @dfn{service types} to express these
31759 relations. There can be any number of services of a given type on the
31760 system---for instance, a system running two instances of the GNU secure
31761 shell server (lsh) has two instances of @code{lsh-service-type}, with
31762 different parameters.
31764 The following section describes the programming interface for service
31765 types and services.
31767 @node Service Types and Services
31768 @subsection Service Types and Services
31770 A @dfn{service type} is a node in the DAG described above. Let us start
31771 with a simple example, the service type for the Guix build daemon
31772 (@pxref{Invoking guix-daemon}):
31775 (define guix-service-type
31779 (list (service-extension shepherd-root-service-type guix-shepherd-service)
31780 (service-extension account-service-type guix-accounts)
31781 (service-extension activation-service-type guix-activation)))
31782 (default-value (guix-configuration))))
31786 It defines three things:
31790 A name, whose sole purpose is to make inspection and debugging easier.
31793 A list of @dfn{service extensions}, where each extension designates the
31794 target service type and a procedure that, given the parameters of the
31795 service, returns a list of objects to extend the service of that type.
31797 Every service type has at least one service extension. The only
31798 exception is the @dfn{boot service type}, which is the ultimate service.
31801 Optionally, a default value for instances of this type.
31804 In this example, @code{guix-service-type} extends three services:
31807 @item shepherd-root-service-type
31808 The @code{guix-shepherd-service} procedure defines how the Shepherd
31809 service is extended. Namely, it returns a @code{<shepherd-service>}
31810 object that defines how @command{guix-daemon} is started and stopped
31811 (@pxref{Shepherd Services}).
31813 @item account-service-type
31814 This extension for this service is computed by @code{guix-accounts},
31815 which returns a list of @code{user-group} and @code{user-account}
31816 objects representing the build user accounts (@pxref{Invoking
31819 @item activation-service-type
31820 Here @code{guix-activation} is a procedure that returns a gexp, which is
31821 a code snippet to run at ``activation time''---e.g., when the service is
31825 A service of this type is instantiated like this:
31828 (service guix-service-type
31829 (guix-configuration
31831 (extra-options '("--gc-keep-derivations"))))
31834 The second argument to the @code{service} form is a value representing
31835 the parameters of this specific service instance.
31836 @xref{guix-configuration-type, @code{guix-configuration}}, for
31837 information about the @code{guix-configuration} data type. When the
31838 value is omitted, the default value specified by
31839 @code{guix-service-type} is used:
31842 (service guix-service-type)
31845 @code{guix-service-type} is quite simple because it extends other
31846 services but is not extensible itself.
31848 @c @subsubsubsection Extensible Service Types
31850 The service type for an @emph{extensible} service looks like this:
31853 (define udev-service-type
31854 (service-type (name 'udev)
31856 (list (service-extension shepherd-root-service-type
31857 udev-shepherd-service)))
31859 (compose concatenate) ;concatenate the list of rules
31860 (extend (lambda (config rules)
31862 (($ <udev-configuration> udev initial-rules)
31863 (udev-configuration
31864 (udev udev) ;the udev package to use
31865 (rules (append initial-rules rules)))))))))
31868 This is the service type for the
31869 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
31870 management daemon}. Compared to the previous example, in addition to an
31871 extension of @code{shepherd-root-service-type}, we see two new fields:
31875 This is the procedure to @dfn{compose} the list of extensions to
31876 services of this type.
31878 Services can extend the udev service by passing it lists of rules; we
31879 compose those extensions simply by concatenating them.
31882 This procedure defines how the value of the service is @dfn{extended} with
31883 the composition of the extensions.
31885 Udev extensions are composed into a list of rules, but the udev service
31886 value is itself a @code{<udev-configuration>} record. So here, we
31887 extend that record by appending the list of rules it contains to the
31888 list of contributed rules.
31891 This is a string giving an overview of the service type. The string can
31892 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
31893 @command{guix system search} command searches these strings and displays
31894 them (@pxref{Invoking guix system}).
31897 There can be only one instance of an extensible service type such as
31898 @code{udev-service-type}. If there were more, the
31899 @code{service-extension} specifications would be ambiguous.
31901 Still here? The next section provides a reference of the programming
31902 interface for services.
31904 @node Service Reference
31905 @subsection Service Reference
31907 We have seen an overview of service types (@pxref{Service Types and
31908 Services}). This section provides a reference on how to manipulate
31909 services and service types. This interface is provided by the
31910 @code{(gnu services)} module.
31912 @deffn {Scheme Procedure} service @var{type} [@var{value}]
31913 Return a new service of @var{type}, a @code{<service-type>} object (see
31914 below). @var{value} can be any object; it represents the parameters of
31915 this particular service instance.
31917 When @var{value} is omitted, the default value specified by @var{type}
31918 is used; if @var{type} does not specify a default value, an error is
31921 For instance, this:
31924 (service openssh-service-type)
31928 is equivalent to this:
31931 (service openssh-service-type
31932 (openssh-configuration))
31935 In both cases the result is an instance of @code{openssh-service-type}
31936 with the default configuration.
31939 @deffn {Scheme Procedure} service? @var{obj}
31940 Return true if @var{obj} is a service.
31943 @deffn {Scheme Procedure} service-kind @var{service}
31944 Return the type of @var{service}---i.e., a @code{<service-type>} object.
31947 @deffn {Scheme Procedure} service-value @var{service}
31948 Return the value associated with @var{service}. It represents its
31952 Here is an example of how a service is created and manipulated:
31956 (service nginx-service-type
31957 (nginx-configuration
31959 (log-directory log-directory)
31960 (run-directory run-directory)
31961 (file config-file))))
31966 (eq? (service-kind s) nginx-service-type)
31970 The @code{modify-services} form provides a handy way to change the
31971 parameters of some of the services of a list such as
31972 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
31973 evaluates to a list of services. Of course, you could always use
31974 standard list combinators such as @code{map} and @code{fold} to do that
31975 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
31976 @code{modify-services} simply provides a more concise form for this
31979 @deffn {Scheme Syntax} modify-services @var{services} @
31980 (@var{type} @var{variable} => @var{body}) @dots{}
31982 Modify the services listed in @var{services} according to the given
31983 clauses. Each clause has the form:
31986 (@var{type} @var{variable} => @var{body})
31989 where @var{type} is a service type---e.g.,
31990 @code{guix-service-type}---and @var{variable} is an identifier that is
31991 bound within the @var{body} to the service parameters---e.g., a
31992 @code{guix-configuration} instance---of the original service of that
31995 The @var{body} should evaluate to the new service parameters, which will
31996 be used to configure the new service. This new service will replace the
31997 original in the resulting list. Because a service's service parameters
31998 are created using @code{define-record-type*}, you can write a succinct
31999 @var{body} that evaluates to the new service parameters by using the
32000 @code{inherit} feature that @code{define-record-type*} provides.
32002 @xref{Using the Configuration System}, for example usage.
32006 Next comes the programming interface for service types. This is
32007 something you want to know when writing new service definitions, but not
32008 necessarily when simply looking for ways to customize your
32009 @code{operating-system} declaration.
32011 @deftp {Data Type} service-type
32012 @cindex service type
32013 This is the representation of a @dfn{service type} (@pxref{Service Types
32018 This is a symbol, used only to simplify inspection and debugging.
32020 @item @code{extensions}
32021 A non-empty list of @code{<service-extension>} objects (see below).
32023 @item @code{compose} (default: @code{#f})
32024 If this is @code{#f}, then the service type denotes services that cannot
32025 be extended---i.e., services that do not receive ``values'' from other
32028 Otherwise, it must be a one-argument procedure. The procedure is called
32029 by @code{fold-services} and is passed a list of values collected from
32030 extensions. It may return any single value.
32032 @item @code{extend} (default: @code{#f})
32033 If this is @code{#f}, services of this type cannot be extended.
32035 Otherwise, it must be a two-argument procedure: @code{fold-services}
32036 calls it, passing it the initial value of the service as the first
32037 argument and the result of applying @code{compose} to the extension
32038 values as the second argument. It must return a value that is a valid
32039 parameter value for the service instance.
32041 @item @code{description}
32042 This is a string, possibly using Texinfo markup, describing in a couple
32043 of sentences what the service is about. This string allows users to
32044 find about the service through @command{guix system search}
32045 (@pxref{Invoking guix system}).
32047 @item @code{default-value} (default: @code{&no-default-value})
32048 The default value associated for instances of this service type. This
32049 allows users to use the @code{service} form without its second argument:
32052 (service @var{type})
32055 The returned service in this case has the default value specified by
32059 @xref{Service Types and Services}, for examples.
32062 @deffn {Scheme Procedure} service-extension @var{target-type} @
32064 Return a new extension for services of type @var{target-type}.
32065 @var{compute} must be a one-argument procedure: @code{fold-services}
32066 calls it, passing it the value associated with the service that provides
32067 the extension; it must return a valid value for the target service.
32070 @deffn {Scheme Procedure} service-extension? @var{obj}
32071 Return true if @var{obj} is a service extension.
32074 Occasionally, you might want to simply extend an existing service. This
32075 involves creating a new service type and specifying the extension of
32076 interest, which can be verbose; the @code{simple-service} procedure
32077 provides a shorthand for this.
32079 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
32080 Return a service that extends @var{target} with @var{value}. This works
32081 by creating a singleton service type @var{name}, of which the returned
32082 service is an instance.
32084 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
32088 (simple-service 'my-mcron-job mcron-service-type
32089 #~(job '(next-hour (3)) "guix gc -F 2G"))
32093 At the core of the service abstraction lies the @code{fold-services}
32094 procedure, which is responsible for ``compiling'' a list of services
32095 down to a single directory that contains everything needed to boot and
32096 run the system---the directory shown by the @command{guix system build}
32097 command (@pxref{Invoking guix system}). In essence, it propagates
32098 service extensions down the service graph, updating each node parameters
32099 on the way, until it reaches the root node.
32101 @deffn {Scheme Procedure} fold-services @var{services} @
32102 [#:target-type @var{system-service-type}]
32103 Fold @var{services} by propagating their extensions down to the root of
32104 type @var{target-type}; return the root service adjusted accordingly.
32107 Lastly, the @code{(gnu services)} module also defines several essential
32108 service types, some of which are listed below.
32110 @defvr {Scheme Variable} system-service-type
32111 This is the root of the service graph. It produces the system directory
32112 as returned by the @command{guix system build} command.
32115 @defvr {Scheme Variable} boot-service-type
32116 The type of the ``boot service'', which produces the @dfn{boot script}.
32117 The boot script is what the initial RAM disk runs when booting.
32120 @defvr {Scheme Variable} etc-service-type
32121 The type of the @file{/etc} service. This service is used to create
32122 files under @file{/etc} and can be extended by
32123 passing it name/file tuples such as:
32126 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
32129 In this example, the effect would be to add an @file{/etc/issue} file
32130 pointing to the given file.
32133 @defvr {Scheme Variable} setuid-program-service-type
32134 Type for the ``setuid-program service''. This service collects lists of
32135 executable file names, passed as gexps, and adds them to the set of
32136 setuid-root programs on the system (@pxref{Setuid Programs}).
32139 @defvr {Scheme Variable} profile-service-type
32140 Type of the service that populates the @dfn{system profile}---i.e., the
32141 programs under @file{/run/current-system/profile}. Other services can
32142 extend it by passing it lists of packages to add to the system profile.
32145 @cindex provenance tracking, of the operating system
32146 @anchor{provenance-service-type}
32147 @defvr {Scheme Variable} provenance-service-type
32148 This is the type of the service that records @dfn{provenance meta-data}
32149 in the system itself. It creates several files under
32150 @file{/run/current-system}:
32154 This is a ``channel file'' that can be passed to @command{guix pull -C}
32155 or @command{guix time-machine -C}, and which describes the channels used
32156 to build the system, if that information was available
32157 (@pxref{Channels}).
32159 @item configuration.scm
32160 This is the file that was passed as the value for this
32161 @code{provenance-service-type} service. By default, @command{guix
32162 system reconfigure} automatically passes the OS configuration file it
32163 received on the command line.
32166 This contains the same information as the two other files but in a
32167 format that is more readily processable.
32170 In general, these two pieces of information (channels and configuration
32171 file) are enough to reproduce the operating system ``from source''.
32174 This information is necessary to rebuild your operating system, but it
32175 is not always sufficient. In particular, @file{configuration.scm}
32176 itself is insufficient if it is not self-contained---if it refers to
32177 external Guile modules or to extra files. If you want
32178 @file{configuration.scm} to be self-contained, we recommend that modules
32179 or files it refers to be part of a channel.
32181 Besides, provenance meta-data is ``silent'' in the sense that it does
32182 not change the bits contained in your system, @emph{except for the
32183 meta-data bits themselves}. Two different OS configurations or sets of
32184 channels can lead to the same system, bit-for-bit; when
32185 @code{provenance-service-type} is used, these two systems will have
32186 different meta-data and thus different store file names, which makes
32187 comparison less trivial.
32190 This service is automatically added to your operating system
32191 configuration when you use @command{guix system reconfigure},
32192 @command{guix system init}, or @command{guix deploy}.
32195 @node Shepherd Services
32196 @subsection Shepherd Services
32198 @cindex shepherd services
32200 @cindex init system
32201 The @code{(gnu services shepherd)} module provides a way to define
32202 services managed by the GNU@tie{}Shepherd, which is the
32203 initialization system---the first process that is started when the
32204 system boots, also known as PID@tie{}1
32205 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
32207 Services in the Shepherd can depend on each other. For instance, the
32208 SSH daemon may need to be started after the syslog daemon has been
32209 started, which in turn can only happen once all the file systems have
32210 been mounted. The simple operating system defined earlier (@pxref{Using
32211 the Configuration System}) results in a service graph like this:
32213 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
32215 You can actually generate such a graph for any operating system
32216 definition using the @command{guix system shepherd-graph} command
32217 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
32219 The @code{%shepherd-root-service} is a service object representing
32220 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
32221 by passing it lists of @code{<shepherd-service>} objects.
32223 @deftp {Data Type} shepherd-service
32224 The data type representing a service managed by the Shepherd.
32227 @item @code{provision}
32228 This is a list of symbols denoting what the service provides.
32230 These are the names that may be passed to @command{herd start},
32231 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
32232 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
32233 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
32235 @item @code{requirement} (default: @code{'()})
32236 List of symbols denoting the Shepherd services this one depends on.
32238 @cindex one-shot services, for the Shepherd
32239 @item @code{one-shot?} (default: @code{#f})
32240 Whether this service is @dfn{one-shot}. One-shot services stop immediately
32241 after their @code{start} action has completed. @xref{Slots of services,,,
32242 shepherd, The GNU Shepherd Manual}, for more info.
32244 @item @code{respawn?} (default: @code{#t})
32245 Whether to restart the service when it stops, for instance when the
32246 underlying process dies.
32249 @itemx @code{stop} (default: @code{#~(const #f)})
32250 The @code{start} and @code{stop} fields refer to the Shepherd's
32251 facilities to start and stop processes (@pxref{Service De- and
32252 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
32253 G-expressions that get expanded in the Shepherd configuration file
32254 (@pxref{G-Expressions}).
32256 @item @code{actions} (default: @code{'()})
32257 @cindex actions, of Shepherd services
32258 This is a list of @code{shepherd-action} objects (see below) defining
32259 @dfn{actions} supported by the service, in addition to the standard
32260 @code{start} and @code{stop} actions. Actions listed here become available as
32261 @command{herd} sub-commands:
32264 herd @var{action} @var{service} [@var{arguments}@dots{}]
32267 @item @code{auto-start?} (default: @code{#t})
32268 Whether this service should be started automatically by the Shepherd. If it
32269 is @code{#f} the service has to be started manually with @code{herd start}.
32271 @item @code{documentation}
32272 A documentation string, as shown when running:
32275 herd doc @var{service-name}
32278 where @var{service-name} is one of the symbols in @code{provision}
32279 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
32281 @item @code{modules} (default: @code{%default-modules})
32282 This is the list of modules that must be in scope when @code{start} and
32283 @code{stop} are evaluated.
32288 @deftp {Data Type} shepherd-action
32289 This is the data type that defines additional actions implemented by a
32290 Shepherd service (see above).
32294 Symbol naming the action.
32296 @item documentation
32297 This is a documentation string for the action. It can be viewed by running:
32300 herd doc @var{service} action @var{action}
32304 This should be a gexp that evaluates to a procedure of at least one argument,
32305 which is the ``running value'' of the service (@pxref{Slots of services,,,
32306 shepherd, The GNU Shepherd Manual}).
32309 The following example defines an action called @code{say-hello} that kindly
32315 (documentation "Say hi!")
32316 (procedure #~(lambda (running . args)
32317 (format #t "Hello, friend! arguments: ~s\n"
32322 Assuming this action is added to the @code{example} service, then you can do:
32325 # herd say-hello example
32326 Hello, friend! arguments: ()
32327 # herd say-hello example a b c
32328 Hello, friend! arguments: ("a" "b" "c")
32331 This, as you can see, is a fairly sophisticated way to say hello.
32332 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
32336 @defvr {Scheme Variable} shepherd-root-service-type
32337 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
32339 This is the service type that extensions target when they want to create
32340 shepherd services (@pxref{Service Types and Services}, for an example).
32341 Each extension must pass a list of @code{<shepherd-service>}.
32344 @defvr {Scheme Variable} %shepherd-root-service
32345 This service represents PID@tie{}1.
32349 @node Documentation
32350 @chapter Documentation
32352 @cindex documentation, searching for
32353 @cindex searching for documentation
32354 @cindex Info, documentation format
32356 @cindex manual pages
32357 In most cases packages installed with Guix come with documentation.
32358 There are two main documentation formats: ``Info'', a browseable
32359 hypertext format used for GNU software, and ``manual pages'' (or ``man
32360 pages''), the linear documentation format traditionally found on Unix.
32361 Info manuals are accessed with the @command{info} command or with Emacs,
32362 and man pages are accessed using @command{man}.
32364 You can look for documentation of software installed on your system by
32365 keyword. For example, the following command searches for information
32366 about ``TLS'' in Info manuals:
32370 "(emacs)Network Security" -- STARTTLS
32371 "(emacs)Network Security" -- TLS
32372 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
32373 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
32378 The command below searches for the same keyword in man pages:
32382 SSL (7) - OpenSSL SSL/TLS library
32383 certtool (1) - GnuTLS certificate tool
32387 These searches are purely local to your computer so you have the
32388 guarantee that documentation you find corresponds to what you have
32389 actually installed, you can access it off-line, and your privacy is
32392 Once you have these results, you can view the relevant documentation by
32396 $ info "(gnutls)Core TLS API"
32406 Info manuals contain sections and indices as well as hyperlinks like
32407 those found in Web pages. The @command{info} reader (@pxref{Top, Info
32408 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
32409 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
32410 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
32411 Introduction}, for an introduction to Info navigation.
32413 @node Installing Debugging Files
32414 @chapter Installing Debugging Files
32416 @cindex debugging files
32417 Program binaries, as produced by the GCC compilers for instance, are
32418 typically written in the ELF format, with a section containing
32419 @dfn{debugging information}. Debugging information is what allows the
32420 debugger, GDB, to map binary code to source code; it is required to
32421 debug a compiled program in good conditions.
32423 This chapter explains how to use separate debug info when packages
32424 provide it, and how to rebuild packages with debug info when it's
32428 * Separate Debug Info:: Installing 'debug' outputs.
32429 * Rebuilding Debug Info:: Building missing debug info.
32432 @node Separate Debug Info
32433 @section Separate Debug Info
32435 The problem with debugging information is that is takes up a fair amount
32436 of disk space. For example, debugging information for the GNU C Library
32437 weighs in at more than 60 MiB. Thus, as a user, keeping all the
32438 debugging info of all the installed programs is usually not an option.
32439 Yet, space savings should not come at the cost of an impediment to
32440 debugging---especially in the GNU system, which should make it easier
32441 for users to exert their computing freedom (@pxref{GNU Distribution}).
32443 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
32444 mechanism that allows users to get the best of both worlds: debugging
32445 information can be stripped from the binaries and stored in separate
32446 files. GDB is then able to load debugging information from those files,
32447 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
32450 The GNU distribution takes advantage of this by storing debugging
32451 information in the @code{lib/debug} sub-directory of a separate package
32452 output unimaginatively called @code{debug} (@pxref{Packages with
32453 Multiple Outputs}). Users can choose to install the @code{debug} output
32454 of a package when they need it. For instance, the following command
32455 installs the debugging information for the GNU C Library and for GNU
32459 guix install glibc:debug guile:debug
32462 GDB must then be told to look for debug files in the user's profile, by
32463 setting the @code{debug-file-directory} variable (consider setting it
32464 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
32468 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
32471 From there on, GDB will pick up debugging information from the
32472 @file{.debug} files under @file{~/.guix-profile/lib/debug}.
32474 In addition, you will most likely want GDB to be able to show the source
32475 code being debugged. To do that, you will have to unpack the source
32476 code of the package of interest (obtained with @code{guix build
32477 --source}, @pxref{Invoking guix build}), and to point GDB to that source
32478 directory using the @code{directory} command (@pxref{Source Path,
32479 @code{directory},, gdb, Debugging with GDB}).
32481 @c XXX: keep me up-to-date
32482 The @code{debug} output mechanism in Guix is implemented by the
32483 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
32484 opt-in---debugging information is available only for the packages with
32485 definitions explicitly declaring a @code{debug} output. To check
32486 whether a package has a @code{debug} output, use @command{guix package
32487 --list-available} (@pxref{Invoking guix package}).
32489 Read on for how to deal with packages lacking a @code{debug} output.
32491 @node Rebuilding Debug Info
32492 @section Rebuilding Debug Info
32494 @cindex debugging info, rebuilding
32495 As we saw above, some packages, but not all, provide debugging info in a
32496 @code{debug} output. What can you do when debugging info is missing?
32497 The @option{--with-debug-info} option provides a solution to that: it
32498 allows you to rebuild the package(s) for which debugging info is
32499 missing---and only those---and to graft those onto the application
32500 you're debugging. Thus, while it's not as fast as installing a
32501 @code{debug} output, it is relatively inexpensive.
32503 Let's illustrate that. Suppose you're experiencing a bug in Inkscape
32504 and would like to see what's going on in GLib, a library that's deep
32505 down in its dependency graph. As it turns out, GLib does not have a
32506 @code{debug} output and the backtrace GDB shows is all sadness:
32510 #0 0x00007ffff5f92190 in g_getenv ()
32511 from /gnu/store/@dots{}-glib-2.62.6/lib/libglib-2.0.so.0
32512 #1 0x00007ffff608a7d6 in gobject_init_ctor ()
32513 from /gnu/store/@dots{}-glib-2.62.6/lib/libgobject-2.0.so.0
32514 #2 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=1, argv=argv@@entry=0x7fffffffcfd8,
32515 env=env@@entry=0x7fffffffcfe8) at dl-init.c:72
32516 #3 0x00007ffff7fe2866 in call_init (env=0x7fffffffcfe8, argv=0x7fffffffcfd8, argc=1, l=<optimized out>)
32520 To address that, you install Inkscape linked against a variant GLib that
32521 contains debug info:
32524 guix install inkscape --with-debug-info=glib
32527 This time, debugging will be a whole lot nicer:
32530 $ gdb --args sh -c 'exec inkscape'
32533 Function "g_getenv" not defined.
32534 Make breakpoint pending on future shared library load? (y or [n]) y
32535 Breakpoint 1 (g_getenv) pending.
32537 Starting program: /gnu/store/@dots{}-profile/bin/sh -c exec\ inkscape
32540 #0 g_getenv (variable=variable@@entry=0x7ffff60c7a2e "GOBJECT_DEBUG") at ../glib-2.62.6/glib/genviron.c:252
32541 #1 0x00007ffff608a7d6 in gobject_init () at ../glib-2.62.6/gobject/gtype.c:4380
32542 #2 gobject_init_ctor () at ../glib-2.62.6/gobject/gtype.c:4493
32543 #3 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=3, argv=argv@@entry=0x7fffffffd088,
32544 env=env@@entry=0x7fffffffd0a8) at dl-init.c:72
32550 Note that there can be packages for which @option{--with-debug-info}
32551 will not have the desired effect. @xref{Package Transformation Options,
32552 @option{--with-debug-info}}, for more information.
32554 @node Security Updates
32555 @chapter Security Updates
32557 @cindex security updates
32558 @cindex security vulnerabilities
32559 Occasionally, important security vulnerabilities are discovered in software
32560 packages and must be patched. Guix developers try hard to keep track of
32561 known vulnerabilities and to apply fixes as soon as possible in the
32562 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
32563 containing only security updates). The @command{guix lint} tool helps
32564 developers find out about vulnerable versions of software packages in the
32569 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
32570 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
32571 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
32575 @xref{Invoking guix lint}, for more information.
32577 Guix follows a functional
32578 package management discipline (@pxref{Introduction}), which implies
32579 that, when a package is changed, @emph{every package that depends on it}
32580 must be rebuilt. This can significantly slow down the deployment of
32581 fixes in core packages such as libc or Bash, since basically the whole
32582 distribution would need to be rebuilt. Using pre-built binaries helps
32583 (@pxref{Substitutes}), but deployment may still take more time than
32587 To address this, Guix implements @dfn{grafts}, a mechanism that allows
32588 for fast deployment of critical updates without the costs associated
32589 with a whole-distribution rebuild. The idea is to rebuild only the
32590 package that needs to be patched, and then to ``graft'' it onto packages
32591 explicitly installed by the user and that were previously referring to
32592 the original package. The cost of grafting is typically very low, and
32593 order of magnitudes lower than a full rebuild of the dependency chain.
32595 @cindex replacements of packages, for grafts
32596 For instance, suppose a security update needs to be applied to Bash.
32597 Guix developers will provide a package definition for the ``fixed''
32598 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
32599 Packages}). Then, the original package definition is augmented with a
32600 @code{replacement} field pointing to the package containing the bug fix:
32607 (replacement bash-fixed)))
32610 From there on, any package depending directly or indirectly on Bash---as
32611 reported by @command{guix gc --requisites} (@pxref{Invoking guix
32612 gc})---that is installed is automatically ``rewritten'' to refer to
32613 @code{bash-fixed} instead of @code{bash}. This grafting process takes
32614 time proportional to the size of the package, usually less than a
32615 minute for an ``average'' package on a recent machine. Grafting is
32616 recursive: when an indirect dependency requires grafting, then grafting
32617 ``propagates'' up to the package that the user is installing.
32619 Currently, the length of the name and version of the graft and that of
32620 the package it replaces (@code{bash-fixed} and @code{bash} in the example
32621 above) must be equal. This restriction mostly comes from the fact that
32622 grafting works by patching files, including binary files, directly.
32623 Other restrictions may apply: for instance, when adding a graft to a
32624 package providing a shared library, the original shared library and its
32625 replacement must have the same @code{SONAME} and be binary-compatible.
32627 The @option{--no-grafts} command-line option allows you to forcefully
32628 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
32632 guix build bash --no-grafts
32636 returns the store file name of the original Bash, whereas:
32643 returns the store file name of the ``fixed'', replacement Bash. This
32644 allows you to distinguish between the two variants of Bash.
32646 To verify which Bash your whole profile refers to, you can run
32647 (@pxref{Invoking guix gc}):
32650 guix gc -R `readlink -f ~/.guix-profile` | grep bash
32654 @dots{} and compare the store file names that you get with those above.
32655 Likewise for a complete Guix system generation:
32658 guix gc -R `guix system build my-config.scm` | grep bash
32661 Lastly, to check which Bash running processes are using, you can use the
32662 @command{lsof} command:
32665 lsof | grep /gnu/store/.*bash
32669 @node Bootstrapping
32670 @chapter Bootstrapping
32672 @c Adapted from the ELS 2013 paper.
32674 @cindex bootstrapping
32676 Bootstrapping in our context refers to how the distribution gets built
32677 ``from nothing''. Remember that the build environment of a derivation
32678 contains nothing but its declared inputs (@pxref{Introduction}). So
32679 there's an obvious chicken-and-egg problem: how does the first package
32680 get built? How does the first compiler get compiled? Note that this is
32681 a question of interest only to the curious hacker, not to the regular
32682 user, so you can shamelessly skip this section if you consider yourself
32683 a ``regular user''.
32685 @cindex bootstrap binaries
32686 The GNU system is primarily made of C code, with libc at its core. The
32687 GNU build system itself assumes the availability of a Bourne shell and
32688 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
32689 `grep'. Furthermore, build programs---programs that run
32690 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
32691 (@pxref{Derivations}). Consequently, to be able to build anything at
32692 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
32693 Binutils, libc, and the other packages mentioned above---the
32694 @dfn{bootstrap binaries}.
32696 These bootstrap binaries are ``taken for granted'', though we can also
32697 re-create them if needed (@pxref{Preparing to Use the Bootstrap
32701 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
32702 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
32705 @node Reduced Binary Seed Bootstrap
32706 @section The Reduced Binary Seed Bootstrap
32708 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
32709 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
32710 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
32711 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
32712 ``taken for granted.''
32714 Taking the bootstrap binaries for granted means that we consider them to
32715 be a correct and trustworthy ``seed'' for building the complete system.
32716 Therein lies a problem: the combined size of these bootstrap binaries is
32717 about 250MB (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing
32718 or even inspecting these is next to impossible.
32720 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a
32721 ``Reduced Binary Seed'' bootstrap @footnote{We would like to say: ``Full
32722 Source Bootstrap'' and while we are working towards that goal it would
32723 be hyperbole to use that term for what we do now.}.
32725 The Reduced Binary Seed bootstrap removes the most critical tools---from a
32726 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
32727 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
32728 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
32729 written in Scheme and the Mes C Library, built for TinyCC and for GCC).
32731 Using these new binary seeds the ``missing'' Binutils, GCC, and the GNU
32732 C Library are built from source. From here on the more traditional
32733 bootstrap process resumes. This approach has reduced the bootstrap
32734 binaries in size to about 145MB in Guix v1.1.
32736 The next step that Guix has taken is to replace the shell and all its
32737 utilities with implementations in Guile Scheme, the @emph{Scheme-only
32738 bootstrap}. Gash (@pxref{Gash,,, gash, The Gash manual}) is a
32739 POSIX-compatible shell that replaces Bash, and it comes with Gash Utils
32740 which has minimalist replacements for Awk, the GNU Core Utilities, Grep,
32741 Gzip, Sed, and Tar. The rest of the bootstrap binary seeds that were
32742 removed are now built from source.
32744 Building the GNU System from source is currently only possibly by adding
32745 some historical GNU packages as intermediate steps@footnote{Packages
32746 such as @code{gcc-2.95.3}, @code{binutils-2.14}, @code{glibc-2.2.5},
32747 @code{gzip-1.2.4}, @code{tar-1.22}, and some others. For details, see
32748 @file{gnu/packages/commencement.scm}.}. As Gash and Gash Utils mature,
32749 and GNU packages become more bootstrappable again (e.g., new releases of
32750 GNU Sed will also ship as gzipped tarballs again, as alternative to the
32751 hard to bootstrap @code{xz}-compression), this set of added packages can
32752 hopefully be reduced again.
32754 The graph below shows the resulting dependency graph for
32755 @code{gcc-core-mesboot0}, the bootstrap compiler used for the
32756 traditional bootstrap of the rest of the Guix System.
32758 @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
32759 @image{images/gcc-core-mesboot0-graph,6in,,Dependency graph of gcc-core-mesboot0}
32761 The only significant binary bootstrap seeds that remain@footnote{
32762 Ignoring the 68KB @code{mescc-tools}; that will be removed later,
32763 together with @code{mes}.} are a Scheme intepreter and a Scheme
32764 compiler: GNU Mes and GNU Guile@footnote{Not shown in this graph are the
32765 static binaries for @file{bash}, @code{tar}, and @code{xz} that are used
32766 to get Guile running.}.
32768 This further reduction has brought down the size of the binary seed to
32769 about 60MB for @code{i686-linux} and @code{x86_64-linux}.
32771 Work is ongoing to remove all binary blobs from our free software
32772 bootstrap stack, working towards a Full Source Bootstrap. Also ongoing
32773 is work to bring these bootstraps to the @code{arm-linux} and
32774 @code{aarch64-linux} architectures and to the Hurd.
32776 If you are interested, join us on @samp{#bootstrappable} on the Freenode
32777 IRC network or discuss on @email{bug-mes@@gnu.org} or
32778 @email{gash-devel@@nongnu.org}.
32780 @node Preparing to Use the Bootstrap Binaries
32781 @section Preparing to Use the Bootstrap Binaries
32783 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
32784 @c large image, it's hard to scroll. Oh well.
32785 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
32787 The figure above shows the very beginning of the dependency graph of the
32788 distribution, corresponding to the package definitions of the @code{(gnu
32789 packages bootstrap)} module. A similar figure can be generated with
32790 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
32793 guix graph -t derivation \
32794 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
32795 | dot -Tps > gcc.ps
32798 or, for the further Reduced Binary Seed bootstrap
32801 guix graph -t derivation \
32802 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
32803 | dot -Tps > mes.ps
32806 At this level of detail, things are
32807 slightly complex. First, Guile itself consists of an ELF executable,
32808 along with many source and compiled Scheme files that are dynamically
32809 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
32810 tarball shown in this graph. This tarball is part of Guix's ``source''
32811 distribution, and gets inserted into the store with @code{add-to-store}
32812 (@pxref{The Store}).
32814 But how do we write a derivation that unpacks this tarball and adds it
32815 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
32816 derivation---the first one that gets built---uses @code{bash} as its
32817 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
32818 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
32819 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
32820 the Guix source distribution, whose sole purpose is to allow the Guile
32821 tarball to be unpacked.
32823 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
32824 Guile that can be used to run subsequent build programs. Its first task
32825 is to download tarballs containing the other pre-built binaries---this
32826 is what the @file{.tar.xz.drv} derivations do. Guix modules such as
32827 @code{ftp-client.scm} are used for this purpose. The
32828 @code{module-import.drv} derivations import those modules in a directory
32829 in the store, using the original layout. The
32830 @code{module-import-compiled.drv} derivations compile those modules, and
32831 write them in an output directory with the right layout. This
32832 corresponds to the @code{#:modules} argument of
32833 @code{build-expression->derivation} (@pxref{Derivations}).
32835 Finally, the various tarballs are unpacked by the derivations
32836 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
32837 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
32838 point we have a working C tool chain.
32840 @unnumberedsec Building the Build Tools
32842 Bootstrapping is complete when we have a full tool chain that does not
32843 depend on the pre-built bootstrap tools discussed above. This
32844 no-dependency requirement is verified by checking whether the files of
32845 the final tool chain contain references to the @file{/gnu/store}
32846 directories of the bootstrap inputs. The process that leads to this
32847 ``final'' tool chain is described by the package definitions found in
32848 the @code{(gnu packages commencement)} module.
32850 The @command{guix graph} command allows us to ``zoom out'' compared to
32851 the graph above, by looking at the level of package objects instead of
32852 individual derivations---remember that a package may translate to
32853 several derivations, typically one derivation to download its source,
32854 one to build the Guile modules it needs, and one to actually build the
32855 package from source. The command:
32858 guix graph -t bag \
32859 -e '(@@@@ (gnu packages commencement)
32860 glibc-final-with-bootstrap-bash)' | xdot -
32864 displays the dependency graph leading to the ``final'' C
32865 library@footnote{You may notice the @code{glibc-intermediate} label,
32866 suggesting that it is not @emph{quite} final, but as a good
32867 approximation, we will consider it final.}, depicted below.
32869 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
32871 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
32872 The first tool that gets built with the bootstrap binaries is
32873 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
32874 for all the following packages. From there Findutils and Diffutils get
32877 Then come the first-stage Binutils and GCC, built as pseudo cross
32878 tools---i.e., with @option{--target} equal to @option{--host}. They are
32879 used to build libc. Thanks to this cross-build trick, this libc is
32880 guaranteed not to hold any reference to the initial tool chain.
32882 From there the final Binutils and GCC (not shown above) are built. GCC
32883 uses @command{ld} from the final Binutils, and links programs against
32884 the just-built libc. This tool chain is used to build the other
32885 packages used by Guix and by the GNU Build System: Guile, Bash,
32888 And voilà! At this point we have the complete set of build tools that
32889 the GNU Build System expects. These are in the @code{%final-inputs}
32890 variable of the @code{(gnu packages commencement)} module, and are
32891 implicitly used by any package that uses @code{gnu-build-system}
32892 (@pxref{Build Systems, @code{gnu-build-system}}).
32895 @unnumberedsec Building the Bootstrap Binaries
32897 @cindex bootstrap binaries
32898 Because the final tool chain does not depend on the bootstrap binaries,
32899 those rarely need to be updated. Nevertheless, it is useful to have an
32900 automated way to produce them, should an update occur, and this is what
32901 the @code{(gnu packages make-bootstrap)} module provides.
32903 The following command builds the tarballs containing the bootstrap binaries
32904 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
32905 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
32906 and Guile, and a tarball containing a mixture of Coreutils and other basic
32907 command-line tools):
32910 guix build bootstrap-tarballs
32913 The generated tarballs are those that should be referred to in the
32914 @code{(gnu packages bootstrap)} module mentioned at the beginning of
32917 Still here? Then perhaps by now you've started to wonder: when do we
32918 reach a fixed point? That is an interesting question! The answer is
32919 unknown, but if you would like to investigate further (and have
32920 significant computational and storage resources to do so), then let us
32923 @unnumberedsec Reducing the Set of Bootstrap Binaries
32925 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
32926 binary code! Why is that a problem? It's a problem because these big chunks
32927 of binary code are practically non-auditable, which makes it hard to establish
32928 what source code produced them. Every unauditable binary also leaves us
32929 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
32930 paper @emph{Reflections on Trusting Trust}.
32932 This is mitigated by the fact that our bootstrap binaries were generated
32933 from an earlier Guix revision. Nevertheless it lacks the level of
32934 transparency that we get in the rest of the package dependency graph,
32935 where Guix always gives us a source-to-binary mapping. Thus, our goal
32936 is to reduce the set of bootstrap binaries to the bare minimum.
32938 The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
32939 on-going projects to do that. One of these is about replacing the
32940 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
32941 of increasing complexity, which could be built from source starting from
32942 a simple and auditable assembler.
32944 Our first major achievement is the replacement of of GCC, the GNU C Library
32945 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
32946 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
32947 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
32948 bootstrapped yet and thus we inject them as binary seeds. We call this the
32949 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
32950 binaries! Also, it has eliminated the C compiler binary; i686-linux and
32951 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
32953 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
32954 also looking at any other bootstrap binaries. Your help is welcome!
32957 @chapter Porting to a New Platform
32959 As discussed above, the GNU distribution is self-contained, and
32960 self-containment is achieved by relying on pre-built ``bootstrap
32961 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
32962 operating system kernel, CPU architecture, and application binary
32963 interface (ABI). Thus, to port the distribution to a platform that is
32964 not yet supported, one must build those bootstrap binaries, and update
32965 the @code{(gnu packages bootstrap)} module to use them on that platform.
32967 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
32968 When everything goes well, and assuming the GNU tool chain supports the
32969 target platform, this can be as simple as running a command like this
32973 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
32976 For this to work, the @code{glibc-dynamic-linker} procedure in
32977 @code{(gnu packages bootstrap)} must be augmented to return the right
32978 file name for libc's dynamic linker on that platform; likewise,
32979 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
32980 taught about the new platform.
32982 Once these are built, the @code{(gnu packages bootstrap)} module needs
32983 to be updated to refer to these binaries on the target platform. That
32984 is, the hashes and URLs of the bootstrap tarballs for the new platform
32985 must be added alongside those of the currently supported platforms. The
32986 bootstrap Guile tarball is treated specially: it is expected to be
32987 available locally, and @file{gnu/local.mk} has rules to download it for
32988 the supported architectures; a rule for the new platform must be added
32991 In practice, there may be some complications. First, it may be that the
32992 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
32993 above) is not recognized by all the GNU tools. Typically, glibc
32994 recognizes some of these, whereas GCC uses an extra @option{--with-abi}
32995 configure flag (see @code{gcc.scm} for examples of how to handle this).
32996 Second, some of the required packages could fail to build for that
32997 platform. Lastly, the generated binaries could be broken for some
33000 @c *********************************************************************
33001 @include contributing.texi
33003 @c *********************************************************************
33004 @node Acknowledgments
33005 @chapter Acknowledgments
33007 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
33008 which was designed and
33009 implemented by Eelco Dolstra, with contributions from other people (see
33010 the @file{nix/AUTHORS} file in Guix). Nix pioneered functional package
33011 management, and promoted unprecedented features, such as transactional
33012 package upgrades and rollbacks, per-user profiles, and referentially
33013 transparent build processes. Without this work, Guix would not exist.
33015 The Nix-based software distributions, Nixpkgs and NixOS, have also been
33016 an inspiration for Guix.
33018 GNU@tie{}Guix itself is a collective work with contributions from a
33019 number of people. See the @file{AUTHORS} file in Guix for more
33020 information on these fine people. The @file{THANKS} file lists people
33021 who have helped by reporting bugs, taking care of the infrastructure,
33022 providing artwork and themes, making suggestions, and more---thank you!
33025 @c *********************************************************************
33026 @node GNU Free Documentation License
33027 @appendix GNU Free Documentation License
33028 @cindex license, GNU Free Documentation License
33029 @include fdl-1.3.texi
33031 @c *********************************************************************
33032 @node Concept Index
33033 @unnumbered Concept Index
33036 @node Programming Index
33037 @unnumbered Programming Index
33038 @syncodeindex tp fn
33039 @syncodeindex vr fn
33044 @c Local Variables:
33045 @c ispell-local-dictionary: "american";