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};
833 @c FIXME: Specify a version number once a release has been made.
834 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, version 0.3.0
836 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON}
838 @item @url{https://www.gnu.org/software/make/, GNU Make}.
841 The following dependencies are optional:
845 @c Note: We need at least 0.13.0 for #:nodelay.
846 Support for build offloading (@pxref{Daemon Offload Setup}) and
847 @command{guix copy} (@pxref{Invoking guix copy}) depends on
848 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
849 version 0.13.0 or later.
852 When @url{https://www.nongnu.org/lzip/lzlib.html, lzlib} is available, lzlib
853 substitutes can be used and @command{guix publish} can compress substitutes
857 When @url{http://www.bzip.org, libbz2} is available,
858 @command{guix-daemon} can use it to compress build logs.
861 Unless @option{--disable-daemon} was passed to @command{configure}, the
862 following packages are also needed:
865 @item @url{https://gnupg.org/, GNU libgcrypt};
866 @item @url{https://sqlite.org, SQLite 3};
867 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
871 @cindex state directory
872 When configuring Guix on a system that already has a Guix installation,
873 be sure to specify the same state directory as the existing installation
874 using the @option{--localstatedir} option of the @command{configure}
875 script (@pxref{Directory Variables, @code{localstatedir},, standards,
876 GNU Coding Standards}). Usually, this @var{localstatedir} option is
877 set to the value @file{/var}. The @command{configure} script protects
878 against unintended misconfiguration of @var{localstatedir} so you do not
879 inadvertently corrupt your store (@pxref{The Store}).
881 @node Running the Test Suite
882 @section Running the Test Suite
885 After a successful @command{configure} and @code{make} run, it is a good
886 idea to run the test suite. It can help catch issues with the setup or
887 environment, or bugs in Guix itself---and really, reporting test
888 failures is a good way to help improve the software. To run the test
895 Test cases can run in parallel: you can use the @code{-j} option of
896 GNU@tie{}make to speed things up. The first run may take a few minutes
897 on a recent machine; subsequent runs will be faster because the store
898 that is created for test purposes will already have various things in
901 It is also possible to run a subset of the tests by defining the
902 @code{TESTS} makefile variable as in this example:
905 make check TESTS="tests/store.scm tests/cpio.scm"
908 By default, tests results are displayed at a file level. In order to
909 see the details of every individual test cases, it is possible to define
910 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
913 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
916 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
917 @file{test-suite.log} file. Please specify the Guix version being used
918 as well as version numbers of the dependencies (@pxref{Requirements}) in
921 Guix also comes with a whole-system test suite that tests complete
922 Guix System instances. It can only run on systems where
923 Guix is already installed, using:
930 or, again, by defining @code{TESTS} to select a subset of tests to run:
933 make check-system TESTS="basic mcron"
936 These system tests are defined in the @code{(gnu tests @dots{})}
937 modules. They work by running the operating systems under test with
938 lightweight instrumentation in a virtual machine (VM). They can be
939 computationally intensive or rather cheap, depending on whether
940 substitutes are available for their dependencies (@pxref{Substitutes}).
941 Some of them require a lot of storage space to hold VM images.
943 Again in case of test failures, please send @email{bug-guix@@gnu.org}
946 @node Setting Up the Daemon
947 @section Setting Up the Daemon
950 Operations such as building a package or running the garbage collector
951 are all performed by a specialized process, the @dfn{build daemon}, on
952 behalf of clients. Only the daemon may access the store and its
953 associated database. Thus, any operation that manipulates the store
954 goes through the daemon. For instance, command-line tools such as
955 @command{guix package} and @command{guix build} communicate with the
956 daemon (@i{via} remote procedure calls) to instruct it what to do.
958 The following sections explain how to prepare the build daemon's
959 environment. See also @ref{Substitutes}, for information on how to allow
960 the daemon to download pre-built binaries.
963 * Build Environment Setup:: Preparing the isolated build environment.
964 * Daemon Offload Setup:: Offloading builds to remote machines.
965 * SELinux Support:: Using an SELinux policy for the daemon.
968 @node Build Environment Setup
969 @subsection Build Environment Setup
971 @cindex build environment
972 In a standard multi-user setup, Guix and its daemon---the
973 @command{guix-daemon} program---are installed by the system
974 administrator; @file{/gnu/store} is owned by @code{root} and
975 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
976 Guix tools to build packages or otherwise access the store, and the
977 daemon will do it on their behalf, ensuring that the store is kept in a
978 consistent state, and allowing built packages to be shared among users.
981 When @command{guix-daemon} runs as @code{root}, you may not want package
982 build processes themselves to run as @code{root} too, for obvious
983 security reasons. To avoid that, a special pool of @dfn{build users}
984 should be created for use by build processes started by the daemon.
985 These build users need not have a shell and a home directory: they will
986 just be used when the daemon drops @code{root} privileges in build
987 processes. Having several such users allows the daemon to launch
988 distinct build processes under separate UIDs, which guarantees that they
989 do not interfere with each other---an essential feature since builds are
990 regarded as pure functions (@pxref{Introduction}).
992 On a GNU/Linux system, a build user pool may be created like this (using
993 Bash syntax and the @code{shadow} commands):
995 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
996 @c for why `-G' is needed.
998 # groupadd --system guixbuild
999 # for i in `seq -w 1 10`;
1001 useradd -g guixbuild -G guixbuild \
1002 -d /var/empty -s `which nologin` \
1003 -c "Guix build user $i" --system \
1009 The number of build users determines how many build jobs may run in
1010 parallel, as specified by the @option{--max-jobs} option
1011 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
1012 @command{guix system vm} and related commands, you may need to add the
1013 build users to the @code{kvm} group so they can access @file{/dev/kvm},
1014 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
1015 (@pxref{Invoking guix system}).
1017 The @code{guix-daemon} program may then be run as @code{root} with the
1018 following command@footnote{If your machine uses the systemd init system,
1019 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
1020 file in @file{/etc/systemd/system} will ensure that
1021 @command{guix-daemon} is automatically started. Similarly, if your
1022 machine uses the Upstart init system, drop the
1023 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
1024 file in @file{/etc/init}.}:
1027 # guix-daemon --build-users-group=guixbuild
1032 This way, the daemon starts build processes in a chroot, under one of
1033 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
1034 environment contains nothing but:
1036 @c Keep this list in sync with libstore/build.cc! -----------------------
1039 a minimal @code{/dev} directory, created mostly independently from the
1040 host @code{/dev}@footnote{``Mostly'', because while the set of files
1041 that appear in the chroot's @code{/dev} is fixed, most of these files
1042 can only be created if the host has them.};
1045 the @code{/proc} directory; it only shows the processes of the container
1046 since a separate PID name space is used;
1049 @file{/etc/passwd} with an entry for the current user and an entry for
1053 @file{/etc/group} with an entry for the user's group;
1056 @file{/etc/hosts} with an entry that maps @code{localhost} to
1060 a writable @file{/tmp} directory.
1063 You can influence the directory where the daemon stores build trees
1064 @i{via} the @env{TMPDIR} environment variable. However, the build tree
1065 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
1066 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
1067 This way, the value of @env{TMPDIR} does not leak inside build
1068 environments, which avoids discrepancies in cases where build processes
1069 capture the name of their build tree.
1073 The daemon also honors the @env{http_proxy} and @env{https_proxy}
1074 environment variables for HTTP and HTTPS downloads it performs, be it
1075 for fixed-output derivations (@pxref{Derivations}) or for substitutes
1076 (@pxref{Substitutes}).
1078 If you are installing Guix as an unprivileged user, it is still possible
1079 to run @command{guix-daemon} provided you pass @option{--disable-chroot}.
1080 However, build processes will not be isolated from one another, and not
1081 from the rest of the system. Thus, build processes may interfere with
1082 each other, and may access programs, libraries, and other files
1083 available on the system---making it much harder to view them as
1084 @emph{pure} functions.
1087 @node Daemon Offload Setup
1088 @subsection Using the Offload Facility
1092 When desired, the build daemon can @dfn{offload} derivation builds to
1093 other machines running Guix, using the @code{offload} @dfn{build
1094 hook}@footnote{This feature is available only when
1095 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1096 present.}. When that feature is enabled, a list of user-specified build
1097 machines is read from @file{/etc/guix/machines.scm}; every time a build
1098 is requested, for instance via @code{guix build}, the daemon attempts to
1099 offload it to one of the machines that satisfy the constraints of the
1100 derivation, in particular its system types---e.g., @code{x86_64-linux}.
1101 A single machine can have multiple system types, either because its
1102 architecture natively supports it, via emulation
1103 (@pxref{transparent-emulation-qemu, Transparent Emulation with QEMU}),
1104 or both. Missing prerequisites for the build are
1105 copied over SSH to the target machine, which then proceeds with the
1106 build; upon success the output(s) of the build are copied back to the
1107 initial machine. The offload facility comes with a basic scheduler that
1108 attempts to select the best machine. The best machine is chosen among
1109 the available machines based on criteria such as:
1113 The availability of a build slot. A build machine can have as many
1114 build slots (connections) as the value of the @code{parallel-builds}
1115 field of its @code{build-machine} object.
1118 Its relative speed, as defined via the @code{speed} field of its
1119 @code{build-machine} object.
1122 Its load. The normalized machine load must be lower than a threshold
1123 value, configurable via the @code{overload-threshold} field of its
1124 @code{build-machine} object.
1127 Disk space availability. More than a 100 MiB must be available.
1130 The @file{/etc/guix/machines.scm} file typically looks like this:
1133 (list (build-machine
1134 (name "eightysix.example.org")
1135 (systems (list "x86_64-linux" "i686-linux"))
1136 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1138 (speed 2.)) ;incredibly fast!
1141 (name "armeight.example.org")
1142 (systems (list "aarch64-linux"))
1143 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1146 (string-append (getenv "HOME")
1147 "/.ssh/identity-for-guix"))))
1151 In the example above we specify a list of two build machines, one for
1152 the @code{x86_64} and @code{i686} architectures and one for the
1153 @code{aarch64} architecture.
1155 In fact, this file is---not surprisingly!---a Scheme file that is
1156 evaluated when the @code{offload} hook is started. Its return value
1157 must be a list of @code{build-machine} objects. While this example
1158 shows a fixed list of build machines, one could imagine, say, using
1159 DNS-SD to return a list of potential build machines discovered in the
1160 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1161 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1164 @deftp {Data Type} build-machine
1165 This data type represents build machines to which the daemon may offload
1166 builds. The important fields are:
1171 The host name of the remote machine.
1174 The system types the remote machine supports---e.g., @code{(list
1175 "x86_64-linux" "i686-linux")}.
1178 The user account to use when connecting to the remote machine over SSH.
1179 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1180 allow non-interactive logins.
1183 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1184 This is used to authenticate the machine when we connect to it. It is a
1185 long string that looks like this:
1188 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1191 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1192 key can be found in a file such as
1193 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1195 If the machine is running the SSH daemon of GNU@tie{}lsh,
1196 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1197 similar file. It can be converted to the OpenSSH format using
1198 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1201 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1202 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1207 A number of optional fields may be specified:
1211 @item @code{port} (default: @code{22})
1212 Port number of SSH server on the machine.
1214 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1215 The SSH private key file to use when connecting to the machine, in
1216 OpenSSH format. This key must not be protected with a passphrase.
1218 Note that the default value is the private key @emph{of the root
1219 account}. Make sure it exists if you use the default.
1221 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1222 @itemx @code{compression-level} (default: @code{3})
1223 The SSH-level compression methods and compression level requested.
1225 Note that offloading relies on SSH compression to reduce bandwidth usage
1226 when transferring files to and from build machines.
1228 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1229 File name of the Unix-domain socket @command{guix-daemon} is listening
1232 @item @code{overload-threshold} (default: @code{0.6})
1233 The load threshold above which a potential offload machine is
1234 disregarded by the offload scheduler. The value roughly translates to
1235 the total processor usage of the build machine, ranging from 0.0 (0%) to
1236 1.0 (100%). It can also be disabled by setting
1237 @code{overload-threshold} to @code{#f}.
1239 @item @code{parallel-builds} (default: @code{1})
1240 The number of builds that may run in parallel on the machine.
1242 @item @code{speed} (default: @code{1.0})
1243 A ``relative speed factor''. The offload scheduler will tend to prefer
1244 machines with a higher speed factor.
1246 @item @code{features} (default: @code{'()})
1247 A list of strings denoting specific features supported by the machine.
1248 An example is @code{"kvm"} for machines that have the KVM Linux modules
1249 and corresponding hardware support. Derivations can request features by
1250 name, and they will be scheduled on matching build machines.
1255 The @command{guix} command must be in the search path on the build
1256 machines. You can check whether this is the case by running:
1259 ssh build-machine guix repl --version
1262 There is one last thing to do once @file{machines.scm} is in place. As
1263 explained above, when offloading, files are transferred back and forth
1264 between the machine stores. For this to work, you first need to
1265 generate a key pair on each machine to allow the daemon to export signed
1266 archives of files from the store (@pxref{Invoking guix archive}):
1269 # guix archive --generate-key
1273 Each build machine must authorize the key of the master machine so that
1274 it accepts store items it receives from the master:
1277 # guix archive --authorize < master-public-key.txt
1281 Likewise, the master machine must authorize the key of each build machine.
1283 All the fuss with keys is here to express pairwise mutual trust
1284 relations between the master and the build machines. Concretely, when
1285 the master receives files from a build machine (and @i{vice versa}), its
1286 build daemon can make sure they are genuine, have not been tampered
1287 with, and that they are signed by an authorized key.
1289 @cindex offload test
1290 To test whether your setup is operational, run this command on the
1297 This will attempt to connect to each of the build machines specified in
1298 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1299 available on each machine, attempt to export to the machine and import
1300 from it, and report any error in the process.
1302 If you want to test a different machine file, just specify it on the
1306 # guix offload test machines-qualif.scm
1309 Last, you can test the subset of the machines whose name matches a
1310 regular expression like this:
1313 # guix offload test machines.scm '\.gnu\.org$'
1316 @cindex offload status
1317 To display the current load of all build hosts, run this command on the
1321 # guix offload status
1325 @node SELinux Support
1326 @subsection SELinux Support
1328 @cindex SELinux, daemon policy
1329 @cindex mandatory access control, SELinux
1330 @cindex security, guix-daemon
1331 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1332 can be installed on a system where SELinux is enabled, in order to label
1333 Guix files and to specify the expected behavior of the daemon. Since
1334 Guix System does not provide an SELinux base policy, the daemon policy cannot
1335 be used on Guix System.
1337 @subsubsection Installing the SELinux policy
1338 @cindex SELinux, policy installation
1339 To install the policy run this command as root:
1342 semodule -i etc/guix-daemon.cil
1345 Then relabel the file system with @code{restorecon} or by a different
1346 mechanism provided by your system.
1348 Once the policy is installed, the file system has been relabeled, and
1349 the daemon has been restarted, it should be running in the
1350 @code{guix_daemon_t} context. You can confirm this with the following
1354 ps -Zax | grep guix-daemon
1357 Monitor the SELinux log files as you run a command like @code{guix build
1358 hello} to convince yourself that SELinux permits all necessary
1361 @subsubsection Limitations
1362 @cindex SELinux, limitations
1364 This policy is not perfect. Here is a list of limitations or quirks
1365 that should be considered when deploying the provided SELinux policy for
1370 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1371 operations involve contexts that have anything to do with
1372 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1373 but it would be preferrable to define socket rules for only this label.
1376 @code{guix gc} cannot access arbitrary links to profiles. By design,
1377 the file label of the destination of a symlink is independent of the
1378 file label of the link itself. Although all profiles under
1379 $localstatedir are labelled, the links to these profiles inherit the
1380 label of the directory they are in. For links in the user’s home
1381 directory this will be @code{user_home_t}. But for links from the root
1382 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1383 directory, etc, this won’t work. @code{guix gc} would be prevented from
1384 reading and following these links.
1387 The daemon’s feature to listen for TCP connections might no longer work.
1388 This might require extra rules, because SELinux treats network sockets
1389 differently from files.
1392 Currently all files with a name matching the regular expression
1393 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1394 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1395 that name in any profile would be permitted to run in the
1396 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1397 build a package that provides this executable and convince a user to
1398 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1399 At that point SELinux could not prevent it from accessing files that are
1400 allowed for processes in that domain.
1402 You will need to relabel the store directory after all upgrades to
1403 @file{guix-daemon}, such as after running @code{guix pull}. Assuming the
1404 store is in @file{/gnu}, you can do this with @code{restorecon -vR /gnu},
1405 or by other means provided by your operating system.
1407 We could generate a much more restrictive policy at installation time,
1408 so that only the @emph{exact} file name of the currently installed
1409 @code{guix-daemon} executable would be labelled with
1410 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1411 The downside is that root would have to install or upgrade the policy at
1412 installation time whenever the Guix package that provides the
1413 effectively running @code{guix-daemon} executable is upgraded.
1416 @node Invoking guix-daemon
1417 @section Invoking @command{guix-daemon}
1419 The @command{guix-daemon} program implements all the functionality to
1420 access the store. This includes launching build processes, running the
1421 garbage collector, querying the availability of a build result, etc. It
1422 is normally run as @code{root} like this:
1425 # guix-daemon --build-users-group=guixbuild
1429 For details on how to set it up, @pxref{Setting Up the Daemon}.
1432 @cindex container, build environment
1433 @cindex build environment
1434 @cindex reproducible builds
1435 By default, @command{guix-daemon} launches build processes under
1436 different UIDs, taken from the build group specified with
1437 @option{--build-users-group}. In addition, each build process is run in a
1438 chroot environment that only contains the subset of the store that the
1439 build process depends on, as specified by its derivation
1440 (@pxref{Programming Interface, derivation}), plus a set of specific
1441 system directories. By default, the latter contains @file{/dev} and
1442 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1443 @dfn{container}: in addition to having its own file system tree, it has
1444 a separate mount name space, its own PID name space, network name space,
1445 etc. This helps achieve reproducible builds (@pxref{Features}).
1447 When the daemon performs a build on behalf of the user, it creates a
1448 build directory under @file{/tmp} or under the directory specified by
1449 its @env{TMPDIR} environment variable. This directory is shared with
1450 the container for the duration of the build, though within the container,
1451 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1453 The build directory is automatically deleted upon completion, unless the
1454 build failed and the client specified @option{--keep-failed}
1455 (@pxref{Invoking guix build, @option{--keep-failed}}).
1457 The daemon listens for connections and spawns one sub-process for each session
1458 started by a client (one of the @command{guix} sub-commands). The
1459 @command{guix processes} command allows you to get an overview of the activity
1460 on your system by viewing each of the active sessions and clients.
1461 @xref{Invoking guix processes}, for more information.
1463 The following command-line options are supported:
1466 @item --build-users-group=@var{group}
1467 Take users from @var{group} to run build processes (@pxref{Setting Up
1468 the Daemon, build users}).
1470 @item --no-substitutes
1472 Do not use substitutes for build products. That is, always build things
1473 locally instead of allowing downloads of pre-built binaries
1474 (@pxref{Substitutes}).
1476 When the daemon runs with @option{--no-substitutes}, clients can still
1477 explicitly enable substitution @i{via} the @code{set-build-options}
1478 remote procedure call (@pxref{The Store}).
1480 @anchor{daemon-substitute-urls}
1481 @item --substitute-urls=@var{urls}
1482 Consider @var{urls} the default whitespace-separated list of substitute
1483 source URLs. When this option is omitted,
1484 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1486 This means that substitutes may be downloaded from @var{urls}, as long
1487 as they are signed by a trusted signature (@pxref{Substitutes}).
1489 @xref{Getting Substitutes from Other Servers}, for more information on
1490 how to configure the daemon to get substitutes from other servers.
1494 Do not use offload builds to other machines (@pxref{Daemon Offload
1495 Setup}). That is, always build things locally instead of offloading
1496 builds to remote machines.
1498 @item --cache-failures
1499 Cache build failures. By default, only successful builds are cached.
1501 When this option is used, @command{guix gc --list-failures} can be used
1502 to query the set of store items marked as failed; @command{guix gc
1503 --clear-failures} removes store items from the set of cached failures.
1504 @xref{Invoking guix gc}.
1506 @item --cores=@var{n}
1508 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1511 The default value is @code{0}, but it may be overridden by clients, such
1512 as the @option{--cores} option of @command{guix build} (@pxref{Invoking
1515 The effect is to define the @env{NIX_BUILD_CORES} environment variable
1516 in the build process, which can then use it to exploit internal
1517 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1519 @item --max-jobs=@var{n}
1521 Allow at most @var{n} build jobs in parallel. The default value is
1522 @code{1}. Setting it to @code{0} means that no builds will be performed
1523 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1524 Setup}), or simply fail.
1526 @item --max-silent-time=@var{seconds}
1527 When the build or substitution process remains silent for more than
1528 @var{seconds}, terminate it and report a build failure.
1530 The default value is @code{0}, which disables the timeout.
1532 The value specified here can be overridden by clients (@pxref{Common
1533 Build Options, @option{--max-silent-time}}).
1535 @item --timeout=@var{seconds}
1536 Likewise, when the build or substitution process lasts for more than
1537 @var{seconds}, terminate it and report a build failure.
1539 The default value is @code{0}, which disables the timeout.
1541 The value specified here can be overridden by clients (@pxref{Common
1542 Build Options, @option{--timeout}}).
1544 @item --rounds=@var{N}
1545 Build each derivation @var{n} times in a row, and raise an error if
1546 consecutive build results are not bit-for-bit identical. Note that this
1547 setting can be overridden by clients such as @command{guix build}
1548 (@pxref{Invoking guix build}).
1550 When used in conjunction with @option{--keep-failed}, the differing
1551 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1552 This makes it easy to look for differences between the two results.
1555 Produce debugging output.
1557 This is useful to debug daemon start-up issues, but then it may be
1558 overridden by clients, for example the @option{--verbosity} option of
1559 @command{guix build} (@pxref{Invoking guix build}).
1561 @item --chroot-directory=@var{dir}
1562 Add @var{dir} to the build chroot.
1564 Doing this may change the result of build processes---for instance if
1565 they use optional dependencies found in @var{dir} when it is available,
1566 and not otherwise. For that reason, it is not recommended to do so.
1567 Instead, make sure that each derivation declares all the inputs that it
1570 @item --disable-chroot
1571 Disable chroot builds.
1573 Using this option is not recommended since, again, it would allow build
1574 processes to gain access to undeclared dependencies. It is necessary,
1575 though, when @command{guix-daemon} is running under an unprivileged user
1578 @item --log-compression=@var{type}
1579 Compress build logs according to @var{type}, one of @code{gzip},
1580 @code{bzip2}, or @code{none}.
1582 Unless @option{--lose-logs} is used, all the build logs are kept in the
1583 @var{localstatedir}. To save space, the daemon automatically compresses
1584 them with Bzip2 by default.
1586 @item --disable-deduplication
1587 @cindex deduplication
1588 Disable automatic file ``deduplication'' in the store.
1590 By default, files added to the store are automatically ``deduplicated'':
1591 if a newly added file is identical to another one found in the store,
1592 the daemon makes the new file a hard link to the other file. This can
1593 noticeably reduce disk usage, at the expense of slightly increased
1594 input/output load at the end of a build process. This option disables
1597 @item --gc-keep-outputs[=yes|no]
1598 Tell whether the garbage collector (GC) must keep outputs of live
1602 @cindex garbage collector roots
1603 When set to @code{yes}, the GC will keep the outputs of any live
1604 derivation available in the store---the @file{.drv} files. The default
1605 is @code{no}, meaning that derivation outputs are kept only if they are
1606 reachable from a GC root. @xref{Invoking guix gc}, for more on GC
1609 @item --gc-keep-derivations[=yes|no]
1610 Tell whether the garbage collector (GC) must keep derivations
1611 corresponding to live outputs.
1613 When set to @code{yes}, as is the case by default, the GC keeps
1614 derivations---i.e., @file{.drv} files---as long as at least one of their
1615 outputs is live. This allows users to keep track of the origins of
1616 items in their store. Setting it to @code{no} saves a bit of disk
1619 In this way, setting @option{--gc-keep-derivations} to @code{yes} causes
1620 liveness to flow from outputs to derivations, and setting
1621 @option{--gc-keep-outputs} to @code{yes} causes liveness to flow from
1622 derivations to outputs. When both are set to @code{yes}, the effect is
1623 to keep all the build prerequisites (the sources, compiler, libraries,
1624 and other build-time tools) of live objects in the store, regardless of
1625 whether these prerequisites are reachable from a GC root. This is
1626 convenient for developers since it saves rebuilds or downloads.
1628 @item --impersonate-linux-2.6
1629 On Linux-based systems, impersonate Linux 2.6. This means that the
1630 kernel's @command{uname} system call will report 2.6 as the release number.
1632 This might be helpful to build programs that (usually wrongfully) depend
1633 on the kernel version number.
1636 Do not keep build logs. By default they are kept under
1637 @file{@var{localstatedir}/guix/log}.
1639 @item --system=@var{system}
1640 Assume @var{system} as the current system type. By default it is the
1641 architecture/kernel pair found at configure time, such as
1642 @code{x86_64-linux}.
1644 @item --listen=@var{endpoint}
1645 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1646 as the file name of a Unix-domain socket if it starts with
1647 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1648 host name or host name and port to listen to. Here are a few examples:
1651 @item --listen=/gnu/var/daemon
1652 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1653 creating it if needed.
1655 @item --listen=localhost
1656 @cindex daemon, remote access
1657 @cindex remote access to the daemon
1658 @cindex daemon, cluster setup
1659 @cindex clusters, daemon setup
1660 Listen for TCP connections on the network interface corresponding to
1661 @code{localhost}, on port 44146.
1663 @item --listen=128.0.0.42:1234
1664 Listen for TCP connections on the network interface corresponding to
1665 @code{128.0.0.42}, on port 1234.
1668 This option can be repeated multiple times, in which case
1669 @command{guix-daemon} accepts connections on all the specified
1670 endpoints. Users can tell client commands what endpoint to connect to
1671 by setting the @env{GUIX_DAEMON_SOCKET} environment variable
1672 (@pxref{The Store, @env{GUIX_DAEMON_SOCKET}}).
1675 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1676 @option{--listen=@var{host}} is suitable on local networks, such as
1677 clusters, where only trusted nodes may connect to the build daemon. In
1678 other cases where remote access to the daemon is needed, we recommend
1679 using Unix-domain sockets along with SSH.
1682 When @option{--listen} is omitted, @command{guix-daemon} listens for
1683 connections on the Unix-domain socket located at
1684 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1688 @node Application Setup
1689 @section Application Setup
1691 @cindex foreign distro
1692 When using Guix on top of GNU/Linux distribution other than Guix System---a
1693 so-called @dfn{foreign distro}---a few additional steps are needed to
1694 get everything in place. Here are some of them.
1698 @anchor{locales-and-locpath}
1699 @cindex locales, when not on Guix System
1701 @vindex GUIX_LOCPATH
1702 Packages installed @i{via} Guix will not use the locale data of the
1703 host system. Instead, you must first install one of the locale packages
1704 available with Guix and then define the @env{GUIX_LOCPATH} environment
1708 $ guix install glibc-locales
1709 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1712 Note that the @code{glibc-locales} package contains data for all the
1713 locales supported by the GNU@tie{}libc and weighs in at around
1714 917@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1715 limited to a few UTF-8 locales.
1717 The @env{GUIX_LOCPATH} variable plays a role similar to @env{LOCPATH}
1718 (@pxref{Locale Names, @env{LOCPATH},, libc, The GNU C Library Reference
1719 Manual}). There are two important differences though:
1723 @env{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1724 provided by foreign distros. Thus, using @env{GUIX_LOCPATH} allows you
1725 to make sure the programs of the foreign distro will not end up loading
1726 incompatible locale data.
1729 libc suffixes each entry of @env{GUIX_LOCPATH} with @code{/X.Y}, where
1730 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1731 should your Guix profile contain a mixture of programs linked against
1732 different libc version, each libc version will only try to load locale
1733 data in the right format.
1736 This is important because the locale data format used by different libc
1737 versions may be incompatible.
1739 @subsection Name Service Switch
1741 @cindex name service switch, glibc
1742 @cindex NSS (name service switch), glibc
1743 @cindex nscd (name service caching daemon)
1744 @cindex name service caching daemon (nscd)
1745 When using Guix on a foreign distro, we @emph{strongly recommend} that
1746 the system run the GNU C library's @dfn{name service cache daemon},
1747 @command{nscd}, which should be listening on the
1748 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1749 installed with Guix may fail to look up host names or user accounts, or
1750 may even crash. The next paragraphs explain why.
1752 @cindex @file{nsswitch.conf}
1753 The GNU C library implements a @dfn{name service switch} (NSS), which is
1754 an extensible mechanism for ``name lookups'' in general: host name
1755 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1756 The GNU C Library Reference Manual}).
1758 @cindex Network information service (NIS)
1759 @cindex NIS (Network information service)
1760 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1761 lookup implementations: for example, the @code{nss-mdns} plugin allow
1762 resolution of @code{.local} host names, the @code{nis} plugin allows
1763 user account lookup using the Network information service (NIS), and so
1764 on. These extra ``lookup services'' are configured system-wide in
1765 @file{/etc/nsswitch.conf}, and all the programs running on the system
1766 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1769 When they perform a name lookup---for instance by calling the
1770 @code{getaddrinfo} function in C---applications first try to connect to
1771 the nscd; on success, nscd performs name lookups on their behalf. If
1772 the nscd is not running, then they perform the name lookup by
1773 themselves, by loading the name lookup services into their own address
1774 space and running it. These name lookup services---the
1775 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1776 the host system's C library, rather than from the C library the
1777 application is linked against (the C library coming from Guix).
1779 And this is where the problem is: if your application is linked against
1780 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1781 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1782 likely crash or have its name lookups fail unexpectedly.
1784 Running @command{nscd} on the system, among other advantages, eliminates
1785 this binary incompatibility problem because those @code{libnss_*.so}
1786 files are loaded in the @command{nscd} process, not in applications
1789 @subsection X11 Fonts
1792 The majority of graphical applications use Fontconfig to locate and
1793 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1794 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1795 by default. Thus, to allow graphical applications installed with Guix
1796 to display fonts, you have to install fonts with Guix as well.
1797 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1798 @code{font-gnu-freefont}.
1800 @cindex @code{fc-cache}
1802 Once you have installed or removed fonts, or when you notice an
1803 application that does not find fonts, you may need to install Fontconfig
1804 and to force an update of its font cache by running:
1807 guix install fontconfig
1811 To display text written in Chinese languages, Japanese, or Korean in
1812 graphical applications, consider installing
1813 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1814 has multiple outputs, one per language family (@pxref{Packages with
1815 Multiple Outputs}). For instance, the following command installs fonts
1816 for Chinese languages:
1819 guix install font-adobe-source-han-sans:cn
1822 @cindex @code{xterm}
1823 Older programs such as @command{xterm} do not use Fontconfig and instead
1824 rely on server-side font rendering. Such programs require to specify a
1825 full name of a font using XLFD (X Logical Font Description), like this:
1828 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1831 To be able to use such full names for the TrueType fonts installed in
1832 your Guix profile, you need to extend the font path of the X server:
1834 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1835 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1837 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1840 @cindex @code{xlsfonts}
1841 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1842 to make sure your TrueType fonts are listed there.
1845 @subsection X.509 Certificates
1847 @cindex @code{nss-certs}
1848 The @code{nss-certs} package provides X.509 certificates, which allow
1849 programs to authenticate Web servers accessed over HTTPS.
1851 When using Guix on a foreign distro, you can install this package and
1852 define the relevant environment variables so that packages know where to
1853 look for certificates. @xref{X.509 Certificates}, for detailed
1856 @subsection Emacs Packages
1858 @cindex @code{emacs}
1859 When you install Emacs packages with Guix, the Elisp files are placed
1860 under the @file{share/emacs/site-lisp/} directory of the profile in
1861 which they are installed. The Elisp libraries are made available to
1862 Emacs through the @env{EMACSLOADPATH} environment variable, which is
1863 set when installing Emacs itself.
1865 Additionally, autoload definitions are automatically evaluated at the
1866 initialization of Emacs, by the Guix-specific
1867 @code{guix-emacs-autoload-packages} procedure. If, for some reason, you
1868 want to avoid auto-loading the Emacs packages installed with Guix, you
1869 can do so by running Emacs with the @option{--no-site-file} option
1870 (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1873 @node Upgrading Guix
1874 @section Upgrading Guix
1876 @cindex Upgrading Guix, on a foreign distro
1878 To upgrade Guix, run:
1884 @xref{Invoking guix pull}, for more information.
1886 @cindex upgrading Guix for the root user, on a foreign distro
1887 @cindex upgrading the Guix daemon, on a foreign distro
1888 @cindex @command{guix pull} for the root user, on a foreign distro
1890 On a foreign distro, you can upgrade the build daemon by running:
1897 followed by (assuming your distro uses the systemd service management
1901 systemctl restart guix-daemon.service
1904 On Guix System, upgrading the daemon is achieved by reconfiguring the
1905 system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
1909 @c *********************************************************************
1910 @node System Installation
1911 @chapter System Installation
1913 @cindex installing Guix System
1914 @cindex Guix System, installation
1915 This section explains how to install Guix System
1916 on a machine. Guix, as a package manager, can
1917 also be installed on top of a running GNU/Linux system,
1918 @pxref{Installation}.
1922 @c This paragraph is for people reading this from tty2 of the
1923 @c installation image.
1924 You are reading this documentation with an Info reader. For details on
1925 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1926 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1927 Info}. Hit @kbd{l} afterwards to come back here.
1929 Alternatively, run @command{info info} in another tty to keep the manual
1935 * Limitations:: What you can expect.
1936 * Hardware Considerations:: Supported hardware.
1937 * USB Stick and DVD Installation:: Preparing the installation medium.
1938 * Preparing for Installation:: Networking, partitioning, etc.
1939 * Guided Graphical Installation:: Easy graphical installation.
1940 * Manual Installation:: Manual installation for wizards.
1941 * After System Installation:: When installation succeeded.
1942 * Installing Guix in a VM:: Guix System playground.
1943 * Building the Installation Image:: How this comes to be.
1947 @section Limitations
1949 We consider Guix System to be ready for a wide range of ``desktop'' and server
1950 use cases. The reliability guarantees it provides---transactional upgrades
1951 and rollbacks, reproducibility---make it a solid foundation.
1953 Nevertheless, before you proceed with the installation, be aware of the
1954 following noteworthy limitations applicable to version @value{VERSION}:
1958 Support for the Logical Volume Manager (LVM) is missing.
1961 More and more system services are provided (@pxref{Services}), but some
1965 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1966 as well as a number of X11 window managers. However, KDE is currently
1970 More than a disclaimer, this is an invitation to report issues (and success
1971 stories!), and to join us in improving it. @xref{Contributing}, for more
1975 @node Hardware Considerations
1976 @section Hardware Considerations
1978 @cindex hardware support on Guix System
1979 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1980 builds around the kernel Linux-libre, which means that only hardware for
1981 which free software drivers and firmware exist is supported. Nowadays,
1982 a wide range of off-the-shelf hardware is supported on
1983 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1984 Ethernet controllers. Unfortunately, there are still areas where
1985 hardware vendors deny users control over their own computing, and such
1986 hardware is not supported on Guix System.
1988 @cindex WiFi, hardware support
1989 One of the main areas where free drivers or firmware are lacking is WiFi
1990 devices. WiFi devices known to work include those using Atheros chips
1991 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1992 driver, and those using Broadcom/AirForce chips (BCM43xx with
1993 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1994 Linux-libre driver. Free firmware exists for both and is available
1995 out-of-the-box on Guix System, as part of @code{%base-firmware}
1996 (@pxref{operating-system Reference, @code{firmware}}).
1998 @cindex RYF, Respects Your Freedom
1999 The @uref{https://www.fsf.org/, Free Software Foundation} runs
2000 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
2001 certification program for hardware products that respect your freedom
2002 and your privacy and ensure that you have control over your device. We
2003 encourage you to check the list of RYF-certified devices.
2005 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
2006 web site. It contains a catalog of hardware devices with information
2007 about their support in GNU/Linux.
2010 @node USB Stick and DVD Installation
2011 @section USB Stick and DVD Installation
2013 An ISO-9660 installation image that can be written to a USB stick or
2014 burnt to a DVD can be downloaded from
2015 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz},
2016 where you can replace @code{x86_64-linux} with one of:
2020 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
2023 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
2026 @c start duplication of authentication part from ``Binary Installation''
2027 Make sure to download the associated @file{.sig} file and to verify the
2028 authenticity of the image against it, along these lines:
2031 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
2032 $ gpg --verify guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
2035 If that command fails because you do not have the required public key,
2036 then run this command to import it:
2039 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
2040 -qO - | gpg --import -
2044 and rerun the @code{gpg --verify} command.
2046 Take note that a warning like ``This key is not certified with a trusted
2047 signature!'' is normal.
2051 This image contains the tools necessary for an installation.
2052 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
2054 @unnumberedsubsec Copying to a USB Stick
2056 To copy the image to a USB stick, follow these steps:
2060 Decompress the image using the @command{xz} command:
2063 xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
2067 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
2068 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
2069 copy the image with:
2072 dd if=guix-system-install-@value{VERSION}.x86_64-linux.iso of=/dev/sdX status=progress
2076 Access to @file{/dev/sdX} usually requires root privileges.
2079 @unnumberedsubsec Burning on a DVD
2081 To copy the image to a DVD, follow these steps:
2085 Decompress the image using the @command{xz} command:
2088 xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
2092 Insert a blank DVD into your machine, and determine
2093 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
2094 copy the image with:
2097 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.x86_64-linux.iso
2100 Access to @file{/dev/srX} usually requires root privileges.
2103 @unnumberedsubsec Booting
2105 Once this is done, you should be able to reboot the system and boot from
2106 the USB stick or DVD. The latter usually requires you to get in the
2107 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
2108 In order to boot from Libreboot, switch to the command mode by pressing
2109 the @kbd{c} key and type @command{search_grub usb}.
2111 @xref{Installing Guix in a VM}, if, instead, you would like to install
2112 Guix System in a virtual machine (VM).
2115 @node Preparing for Installation
2116 @section Preparing for Installation
2118 Once you have booted, you can use the guided graphical installer, which makes
2119 it easy to get started (@pxref{Guided Graphical Installation}). Alternatively,
2120 if you are already familiar with GNU/Linux and if you want more control than
2121 what the graphical installer provides, you can choose the ``manual''
2122 installation process (@pxref{Manual Installation}).
2124 The graphical installer is available on TTY1. You can obtain root shells on
2125 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
2126 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
2127 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
2128 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2129 which allows you to select text with the left mouse button and to paste it
2130 with the middle button.
2133 Installation requires access to the Internet so that any missing
2134 dependencies of your system configuration can be downloaded. See the
2135 ``Networking'' section below.
2138 @node Guided Graphical Installation
2139 @section Guided Graphical Installation
2141 The graphical installer is a text-based user interface. It will guide you,
2142 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2144 The first dialog boxes allow you to set up the system as you use it during the
2145 installation: you can choose the language, keyboard layout, and set up
2146 networking, which will be used during the installation. The image below shows
2147 the networking dialog.
2149 @image{images/installer-network,5in,, networking setup with the graphical installer}
2151 Later steps allow you to partition your hard disk, as shown in the image
2152 below, to choose whether or not to use encrypted file systems, to enter the
2153 host name and root password, and to create an additional account, among other
2156 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2158 Note that, at any time, the installer allows you to exit the current
2159 installation step and resume at a previous step, as show in the image below.
2161 @image{images/installer-resume,5in,, resuming the installation process}
2163 Once you're done, the installer produces an operating system configuration and
2164 displays it (@pxref{Using the Configuration System}). At that point you can
2165 hit ``OK'' and installation will proceed. On success, you can reboot into the
2166 new system and enjoy. @xref{After System Installation}, for what's next!
2169 @node Manual Installation
2170 @section Manual Installation
2172 This section describes how you would ``manually'' install GNU@tie{}Guix System
2173 on your machine. This option requires familiarity with GNU/Linux, with the
2174 shell, and with common administration tools. If you think this is not for
2175 you, consider using the guided graphical installer (@pxref{Guided Graphical
2178 The installation system provides root shells on TTYs 3 to 6; press
2179 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2180 many common tools needed to install the system. But it is also a full-blown
2181 Guix System, which means that you can install additional packages, should you
2182 need it, using @command{guix package} (@pxref{Invoking guix package}).
2185 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2186 * Proceeding with the Installation:: Installing.
2189 @node Keyboard Layout and Networking and Partitioning
2190 @subsection Keyboard Layout, Networking, and Partitioning
2192 Before you can install the system, you may want to adjust the keyboard layout,
2193 set up networking, and partition your target hard disk. This section will
2194 guide you through this.
2196 @subsubsection Keyboard Layout
2198 @cindex keyboard layout
2199 The installation image uses the US qwerty keyboard layout. If you want
2200 to change it, you can use the @command{loadkeys} command. For example,
2201 the following command selects the Dvorak keyboard layout:
2207 See the files under @file{/run/current-system/profile/share/keymaps} for
2208 a list of available keyboard layouts. Run @command{man loadkeys} for
2211 @subsubsection Networking
2213 Run the following command to see what your network interfaces are called:
2220 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2226 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2227 Wired interfaces have a name starting with @samp{e}; for example, the
2228 interface corresponding to the first on-board Ethernet controller is
2229 called @samp{eno1}. Wireless interfaces have a name starting with
2230 @samp{w}, like @samp{w1p2s0}.
2233 @item Wired connection
2234 To configure a wired network run the following command, substituting
2235 @var{interface} with the name of the wired interface you want to use.
2238 ifconfig @var{interface} up
2242 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2245 ip link set @var{interface} up
2248 @item Wireless connection
2251 To configure wireless networking, you can create a configuration file
2252 for the @command{wpa_supplicant} configuration tool (its location is not
2253 important) using one of the available text editors such as
2257 nano wpa_supplicant.conf
2260 As an example, the following stanza can go to this file and will work
2261 for many wireless networks, provided you give the actual SSID and
2262 passphrase for the network you are connecting to:
2266 ssid="@var{my-ssid}"
2268 psk="the network's secret passphrase"
2272 Start the wireless service and run it in the background with the
2273 following command (substitute @var{interface} with the name of the
2274 network interface you want to use):
2277 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2280 Run @command{man wpa_supplicant} for more information.
2284 At this point, you need to acquire an IP address. On a network where IP
2285 addresses are automatically assigned @i{via} DHCP, you can run:
2288 dhclient -v @var{interface}
2291 Try to ping a server to see if networking is up and running:
2297 Setting up network access is almost always a requirement because the
2298 image does not contain all the software and tools that may be needed.
2300 @cindex proxy, during system installation
2301 If you need HTTP and HTTPS access to go through a proxy, run the
2305 herd set-http-proxy guix-daemon @var{URL}
2309 where @var{URL} is the proxy URL, for example
2310 @code{http://example.org:8118}.
2312 @cindex installing over SSH
2313 If you want to, you can continue the installation remotely by starting
2317 herd start ssh-daemon
2320 Make sure to either set a password with @command{passwd}, or configure
2321 OpenSSH public key authentication before logging in.
2323 @subsubsection Disk Partitioning
2325 Unless this has already been done, the next step is to partition, and
2326 then format the target partition(s).
2328 The installation image includes several partitioning tools, including
2329 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2330 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2331 the partition layout you want:
2337 If your disk uses the GUID Partition Table (GPT) format and you plan to
2338 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2339 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2342 @cindex EFI, installation
2343 @cindex UEFI, installation
2344 @cindex ESP, EFI system partition
2345 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2346 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2347 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2350 parted /dev/sda set 1 esp on
2354 @vindex grub-bootloader
2355 @vindex grub-efi-bootloader
2356 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2357 @file{/sys/firmware/efi} exists in the installation image, then you should
2358 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2359 Otherwise you should use the BIOS-based GRUB, known as
2360 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2364 Once you are done partitioning the target hard disk drive, you have to
2365 create a file system on the relevant partition(s)@footnote{Currently
2366 Guix System only supports ext4, btrfs, and JFS file systems. In particular,
2367 code that reads file system UUIDs and labels only works for these file system
2368 types.}. For the ESP, if you have one and assuming it is
2369 @file{/dev/sda1}, run:
2372 mkfs.fat -F32 /dev/sda1
2375 For the root file system, ext4 is the most widely used format. Other
2376 file systems, such as Btrfs, support compression, which is reported to
2377 nicely complement file deduplication that the daemon performs
2378 independently of the file system (@pxref{Invoking guix-daemon,
2381 Preferably, assign file systems a label so that you can easily and
2382 reliably refer to them in @code{file-system} declarations (@pxref{File
2383 Systems}). This is typically done using the @code{-L} option of
2384 @command{mkfs.ext4} and related commands. So, assuming the target root
2385 partition lives at @file{/dev/sda2}, a file system with the label
2386 @code{my-root} can be created with:
2389 mkfs.ext4 -L my-root /dev/sda2
2392 @cindex encrypted disk
2393 If you are instead planning to encrypt the root partition, you can use
2394 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2395 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2396 @code{man cryptsetup}} for more information). Assuming you want to
2397 store the root partition on @file{/dev/sda2}, the command sequence would
2398 be along these lines:
2401 cryptsetup luksFormat /dev/sda2
2402 cryptsetup open --type luks /dev/sda2 my-partition
2403 mkfs.ext4 -L my-root /dev/mapper/my-partition
2406 Once that is done, mount the target file system under @file{/mnt}
2407 with a command like (again, assuming @code{my-root} is the label of the
2411 mount LABEL=my-root /mnt
2414 Also mount any other file systems you would like to use on the target
2415 system relative to this path. If you have opted for @file{/boot/efi} as an
2416 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2417 found by @code{guix system init} afterwards.
2419 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2420 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2421 sure to initialize them with @command{mkswap}. Assuming you have one
2422 swap partition on @file{/dev/sda3}, you would run:
2429 Alternatively, you may use a swap file. For example, assuming that in
2430 the new system you want to use the file @file{/swapfile} as a swap file,
2431 you would run@footnote{This example will work for many types of file
2432 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2433 btrfs), the required steps may be different. For details, see the
2434 manual pages for @command{mkswap} and @command{swapon}.}:
2437 # This is 10 GiB of swap space. Adjust "count" to change the size.
2438 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2439 # For security, make the file readable and writable only by root.
2440 chmod 600 /mnt/swapfile
2441 mkswap /mnt/swapfile
2442 swapon /mnt/swapfile
2445 Note that if you have encrypted the root partition and created a swap
2446 file in its file system as described above, then the encryption also
2447 protects the swap file, just like any other file in that file system.
2449 @node Proceeding with the Installation
2450 @subsection Proceeding with the Installation
2452 With the target partitions ready and the target root mounted on
2453 @file{/mnt}, we're ready to go. First, run:
2456 herd start cow-store /mnt
2459 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2460 during the installation phase are written to the target disk on @file{/mnt}
2461 rather than kept in memory. This is necessary because the first phase of
2462 the @command{guix system init} command (see below) entails downloads or
2463 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2465 Next, you have to edit a file and
2466 provide the declaration of the operating system to be installed. To
2467 that end, the installation system comes with three text editors. We
2468 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2469 supports syntax highlighting and parentheses matching; other editors
2470 include GNU Zile (an Emacs clone), and
2471 nvi (a clone of the original BSD @command{vi} editor).
2472 We strongly recommend storing that file on the target root file system, say,
2473 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2474 configuration file once you have rebooted into the newly-installed system.
2476 @xref{Using the Configuration System}, for an overview of the
2477 configuration file. The example configurations discussed in that
2478 section are available under @file{/etc/configuration} in the
2479 installation image. Thus, to get started with a system configuration
2480 providing a graphical display server (a ``desktop'' system), you can run
2481 something along these lines:
2485 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2486 # nano /mnt/etc/config.scm
2489 You should pay attention to what your configuration file contains, and
2494 Make sure the @code{bootloader-configuration} form refers to the target
2495 you want to install GRUB on. It should mention @code{grub-bootloader} if
2496 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2497 for newer UEFI systems. For legacy systems, the @code{target} field
2498 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2499 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2500 currently mounted and a @code{file-system} entry is specified in your
2504 Be sure that your file system labels match the value of their respective
2505 @code{device} fields in your @code{file-system} configuration, assuming
2506 your @code{file-system} configuration uses the @code{file-system-label}
2507 procedure in its @code{device} field.
2510 If there are encrypted or RAID partitions, make sure to add a
2511 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2514 Once you are done preparing the configuration file, the new system must
2515 be initialized (remember that the target root file system is mounted
2519 guix system init /mnt/etc/config.scm /mnt
2523 This copies all the necessary files and installs GRUB on
2524 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2525 more information, @pxref{Invoking guix system}. This command may trigger
2526 downloads or builds of missing packages, which can take some time.
2528 Once that command has completed---and hopefully succeeded!---you can run
2529 @command{reboot} and boot into the new system. The @code{root} password
2530 in the new system is initially empty; other users' passwords need to be
2531 initialized by running the @command{passwd} command as @code{root},
2532 unless your configuration specifies otherwise
2533 (@pxref{user-account-password, user account passwords}).
2534 @xref{After System Installation}, for what's next!
2537 @node After System Installation
2538 @section After System Installation
2540 Success, you've now booted into Guix System! From then on, you can update the
2541 system whenever you want by running, say:
2545 sudo guix system reconfigure /etc/config.scm
2549 This builds a new system generation with the latest packages and services
2550 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2551 your system includes the latest security updates (@pxref{Security Updates}).
2553 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2555 @cindex sudo vs. @command{guix pull}
2556 Note that @command{sudo guix} runs your user's @command{guix} command and
2557 @emph{not} root's, because @command{sudo} leaves @env{PATH} unchanged. To
2558 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2560 The difference matters here, because @command{guix pull} updates
2561 the @command{guix} command and package definitions only for the user it is ran
2562 as. This means that if you choose to use @command{guix system reconfigure} in
2563 root's login shell, you'll need to @command{guix pull} separately.
2566 Now, @pxref{Getting Started}, and
2567 join us on @code{#guix} on the Freenode IRC network or on
2568 @email{guix-devel@@gnu.org} to share your experience!
2571 @node Installing Guix in a VM
2572 @section Installing Guix in a Virtual Machine
2574 @cindex virtual machine, Guix System installation
2575 @cindex virtual private server (VPS)
2576 @cindex VPS (virtual private server)
2577 If you'd like to install Guix System in a virtual machine (VM) or on a
2578 virtual private server (VPS) rather than on your beloved machine, this
2581 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2582 disk image, follow these steps:
2586 First, retrieve and decompress the Guix system installation image as
2587 described previously (@pxref{USB Stick and DVD Installation}).
2590 Create a disk image that will hold the installed system. To make a
2591 qcow2-formatted disk image, use the @command{qemu-img} command:
2594 qemu-img create -f qcow2 guix-system.img 50G
2597 The resulting file will be much smaller than 50 GB (typically less than
2598 1 MB), but it will grow as the virtualized storage device is filled up.
2601 Boot the USB installation image in an VM:
2604 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2605 -nic user,model=virtio-net-pci -boot menu=on,order=d \
2606 -drive file=guix-system.img \
2607 -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
2610 @code{-enable-kvm} is optional, but significantly improves performance,
2611 @pxref{Running Guix in a VM}.
2614 You're now root in the VM, proceed with the installation process.
2615 @xref{Preparing for Installation}, and follow the instructions.
2618 Once installation is complete, you can boot the system that's on your
2619 @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
2622 @node Building the Installation Image
2623 @section Building the Installation Image
2625 @cindex installation image
2626 The installation image described above was built using the @command{guix
2627 system} command, specifically:
2630 guix system disk-image -t iso9660 gnu/system/install.scm
2633 Have a look at @file{gnu/system/install.scm} in the source tree,
2634 and see also @ref{Invoking guix system} for more information
2635 about the installation image.
2637 @section Building the Installation Image for ARM Boards
2639 Many ARM boards require a specific variant of the
2640 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2642 If you build a disk image and the bootloader is not available otherwise
2643 (on another boot drive etc), it's advisable to build an image that
2644 includes the bootloader, specifically:
2647 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2650 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2651 board, a list of possible boards will be printed.
2653 @c *********************************************************************
2654 @node Getting Started
2655 @chapter Getting Started
2657 Presumably, you've reached this section because either you have
2658 installed Guix on top of another distribution (@pxref{Installation}), or
2659 you've installed the standalone Guix System (@pxref{System
2660 Installation}). It's time for you to get started using Guix and this
2661 section aims to help you do that and give you a feel of what it's like.
2663 Guix is about installing software, so probably the first thing you'll
2664 want to do is to actually look for software. Let's say you're looking
2665 for a text editor, you can run:
2668 guix search text editor
2671 This command shows you a number of matching @dfn{packages}, each time
2672 showing the package's name, version, a description, and additional info.
2673 Once you've found out the one you want to use, let's say Emacs (ah ha!),
2674 you can go ahead and install it (run this command as a regular user,
2675 @emph{no need for root privileges}!):
2681 You've installed your first package, congrats! In the process, you've
2682 probably noticed that Guix downloaded pre-built binaries; or, if you
2683 explicitly chose to @emph{not} use pre-built binaries, then probably
2684 Guix is still building software (@pxref{Substitutes}, for more info).
2686 Unless you're using Guix System, the @command{guix install} command must
2687 have printed this hint:
2690 hint: Consider setting the necessary environment variables by running:
2692 GUIX_PROFILE="$HOME/.guix-profile"
2693 . "$GUIX_PROFILE/etc/profile"
2695 Alternately, see `guix package --search-paths -p "$HOME/.guix-profile"'.
2698 Indeed, you must now tell your shell where @command{emacs} and other
2699 programs installed with Guix are to be found. Pasting the two lines
2700 above will do just that: it will add
2701 @code{$HOME/.guix-profile/bin}---which is where the installed package
2702 is---to the @code{PATH} environment variable. You can paste these two
2703 lines in your shell so they take effect right away, but more importantly
2704 you should add them to @file{~/.bash_profile} (or equivalent file if you
2705 do not use Bash) so that environment variables are set next time you
2706 spawn a shell. You only need to do this once and other search paths
2707 environment variables will be taken care of similarly---e.g., if you
2708 eventually install @code{python} and Python libraries, @code{PYTHONPATH}
2711 You can go on installing packages at your will. To list installed
2715 guix package --list-installed
2718 To remove a package, you would unsurprisingly run @command{guix remove}.
2719 A distinguishing feature is the ability to @dfn{roll back} any operation
2720 you made---installation, removal, upgrade---by simply typing:
2723 guix package --roll-back
2726 This is because each operation is in fact a @dfn{transaction} that
2727 creates a new @dfn{generation}. These generations and the difference
2728 between them can be displayed by running:
2731 guix package --list-generations
2734 Now you know the basics of package management!
2736 @quotation Going further
2737 @xref{Package Management}, for more about package management. You may
2738 like @dfn{declarative} package management with @command{guix package
2739 --manifest}, managing separate @dfn{profiles} with @option{--profile},
2740 deleting old generations, collecting garbage, and other nifty features
2741 that will come in handy as you become more familiar with Guix. If you
2742 are a developer, @pxref{Development} for additional tools. And if
2743 you're curious, @pxref{Features}, to peek under the hood.
2746 Once you've installed a set of packages, you will want to periodically
2747 @emph{upgrade} them to the latest and greatest version. To do that, you
2748 will first pull the latest revision of Guix and its package collection:
2754 The end result is a new @command{guix} command, under
2755 @file{~/.config/guix/current/bin}. Unless you're on Guix System, the
2756 first time you run @command{guix pull}, be sure to follow the hint that
2757 the command prints and, similar to what we saw above, paste these two
2758 lines in your terminal and @file{.bash_profile}:
2761 GUIX_PROFILE="$HOME/.config/guix/current/etc/profile"
2762 . "$GUIX_PROFILE/etc/profile"
2766 You must also instruct your shell to point to this new @command{guix}:
2772 At this point, you're running a brand new Guix. You can thus go ahead
2773 and actually upgrade all the packages you previously installed:
2779 As you run this command, you will see that binaries are downloaded (or
2780 perhaps some packages are built), and eventually you end up with the
2781 upgraded packages. Should one of these upgraded packages not be to your
2782 liking, remember you can always roll back!
2784 You can display the exact revision of Guix you're currently using by
2791 The information it displays is @emph{all it takes to reproduce the exact
2792 same Guix}, be it at a different point in time or on a different
2795 @quotation Going further
2796 @xref{Invoking guix pull}, for more information. @xref{Channels}, on
2797 how to specify additional @dfn{channels} to pull packages from, how to
2798 replicate Guix, and more. You may also find @command{time-machine}
2799 handy (@pxref{Invoking guix time-machine}).
2802 If you installed Guix System, one of the first things you'll want to do
2803 is to upgrade your system. Once you've run @command{guix pull} to get
2804 the latest Guix, you can upgrade the system like this:
2807 sudo guix system reconfigure /etc/config.scm
2810 Upon completion, the system runs the latest versions of its software
2811 packages. When you eventually reboot, you'll notice a sub-menu in the
2812 bootloader that reads ``Old system generations'': it's what allows you
2813 to boot @emph{an older generation of your system}, should the latest
2814 generation be ``broken'' or otherwise unsatisfying. Just like for
2815 packages, you can always @emph{roll back} to a previous generation
2816 @emph{of the whole system}:
2819 sudo guix system roll-back
2822 There are many things you'll probably want to tweak on your system:
2823 adding new user accounts, adding new system services, fiddling with the
2824 configuration of those services, etc. The system configuration is
2825 @emph{entirely} described in the @file{/etc/config.scm} file.
2826 @xref{Using the Configuration System}, to learn how to change it.
2828 Now you know enough to get started!
2830 @quotation Resources
2831 The rest of this manual provides a reference for all things Guix. Here
2832 are some additional resources you may find useful:
2836 @xref{Top,,, guix-cookbook, The GNU Guix Cookbook}, for a list of
2837 ``how-to'' style of recipes for a variety of applications.
2840 The @uref{https://guix.gnu.org/guix-refcard.pdf, GNU Guix Reference
2841 Card} lists in two pages most of the commands and options you'll ever
2845 The web site contains @uref{https://guix.gnu.org/en/videos/,
2846 instructional videos} covering topics such as everyday use of Guix, how
2847 to get help, and how to become a contributor.
2850 @xref{Documentation}, to learn how to access documentation on your
2854 We hope you will enjoy Guix as much as the community enjoys building it!
2857 @c *********************************************************************
2858 @node Package Management
2859 @chapter Package Management
2862 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2863 remove software packages, without having to know about their build
2864 procedures or dependencies. Guix also goes beyond this obvious set of
2867 This chapter describes the main features of Guix, as well as the
2868 package management tools it provides. Along with the command-line
2869 interface described below (@pxref{Invoking guix package, @code{guix
2870 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2871 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2872 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2876 guix install emacs-guix
2880 * Features:: How Guix will make your life brighter.
2881 * Invoking guix package:: Package installation, removal, etc.
2882 * Substitutes:: Downloading pre-built binaries.
2883 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2884 * Invoking guix gc:: Running the garbage collector.
2885 * Invoking guix pull:: Fetching the latest Guix and distribution.
2886 * Invoking guix time-machine:: Running an older revision of Guix.
2887 * Inferiors:: Interacting with another revision of Guix.
2888 * Invoking guix describe:: Display information about your Guix revision.
2889 * Invoking guix archive:: Exporting and importing store files.
2895 Here we assume you've already made your first steps with Guix
2896 (@pxref{Getting Started}) and would like to get an overview about what's
2897 going on under the hood.
2899 When using Guix, each package ends up in the @dfn{package store}, in its
2900 own directory---something that resembles
2901 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2903 Instead of referring to these directories, users have their own
2904 @dfn{profile}, which points to the packages that they actually want to
2905 use. These profiles are stored within each user's home directory, at
2906 @code{$HOME/.guix-profile}.
2908 For example, @code{alice} installs GCC 4.7.2. As a result,
2909 @file{/home/alice/.guix-profile/bin/gcc} points to
2910 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2911 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2912 simply continues to point to
2913 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2914 coexist on the same system without any interference.
2916 The @command{guix package} command is the central tool to manage
2917 packages (@pxref{Invoking guix package}). It operates on the per-user
2918 profiles, and can be used @emph{with normal user privileges}.
2920 @cindex transactions
2921 The command provides the obvious install, remove, and upgrade
2922 operations. Each invocation is actually a @emph{transaction}: either
2923 the specified operation succeeds, or nothing happens. Thus, if the
2924 @command{guix package} process is terminated during the transaction,
2925 or if a power outage occurs during the transaction, then the user's
2926 profile remains in its previous state, and remains usable.
2928 In addition, any package transaction may be @emph{rolled back}. So, if,
2929 for example, an upgrade installs a new version of a package that turns
2930 out to have a serious bug, users may roll back to the previous instance
2931 of their profile, which was known to work well. Similarly, the global
2932 system configuration on Guix is subject to
2933 transactional upgrades and roll-back
2934 (@pxref{Using the Configuration System}).
2936 All packages in the package store may be @emph{garbage-collected}.
2937 Guix can determine which packages are still referenced by user
2938 profiles, and remove those that are provably no longer referenced
2939 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2940 generations of their profile so that the packages they refer to can be
2943 @cindex reproducibility
2944 @cindex reproducible builds
2945 Guix takes a @dfn{purely functional} approach to package
2946 management, as described in the introduction (@pxref{Introduction}).
2947 Each @file{/gnu/store} package directory name contains a hash of all the
2948 inputs that were used to build that package---compiler, libraries, build
2949 scripts, etc. This direct correspondence allows users to make sure a
2950 given package installation matches the current state of their
2951 distribution. It also helps maximize @dfn{build reproducibility}:
2952 thanks to the isolated build environments that are used, a given build
2953 is likely to yield bit-identical files when performed on different
2954 machines (@pxref{Invoking guix-daemon, container}).
2957 This foundation allows Guix to support @dfn{transparent binary/source
2958 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2959 available from an external source---a @dfn{substitute}, Guix just
2960 downloads it and unpacks it;
2961 otherwise, it builds the package from source, locally
2962 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2963 reproducible, users do not have to trust servers that provide
2964 substitutes: they can force a local build and @emph{challenge} providers
2965 (@pxref{Invoking guix challenge}).
2967 Control over the build environment is a feature that is also useful for
2968 developers. The @command{guix environment} command allows developers of
2969 a package to quickly set up the right development environment for their
2970 package, without having to manually install the dependencies of the
2971 package into their profile (@pxref{Invoking guix environment}).
2973 @cindex replication, of software environments
2974 @cindex provenance tracking, of software artifacts
2975 All of Guix and its package definitions is version-controlled, and
2976 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2977 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2978 Guix instance on a different machine or at a later point in time, which in
2979 turn allows you to @emph{replicate complete software environments}, while
2980 retaining precise @dfn{provenance tracking} of the software.
2982 @node Invoking guix package
2983 @section Invoking @command{guix package}
2985 @cindex installing packages
2986 @cindex removing packages
2987 @cindex package installation
2988 @cindex package removal
2989 The @command{guix package} command is the tool that allows users to
2990 install, upgrade, and remove packages, as well as rolling back to
2991 previous configurations. It operates only on the user's own profile,
2992 and works with normal user privileges (@pxref{Features}). Its syntax
2996 guix package @var{options}
2999 @cindex transactions
3000 Primarily, @var{options} specifies the operations to be performed during
3001 the transaction. Upon completion, a new profile is created, but
3002 previous @dfn{generations} of the profile remain available, should the user
3005 For example, to remove @code{lua} and install @code{guile} and
3006 @code{guile-cairo} in a single transaction:
3009 guix package -r lua -i guile guile-cairo
3012 @cindex aliases, for @command{guix package}
3013 For your convenience, we also provide the following aliases:
3017 @command{guix search} is an alias for @command{guix package -s},
3019 @command{guix install} is an alias for @command{guix package -i},
3021 @command{guix remove} is an alias for @command{guix package -r},
3023 @command{guix upgrade} is an alias for @command{guix package -u},
3025 and @command{guix show} is an alias for @command{guix package --show=}.
3028 These aliases are less expressive than @command{guix package} and provide
3029 fewer options, so in some cases you'll probably want to use @command{guix
3032 @command{guix package} also supports a @dfn{declarative approach}
3033 whereby the user specifies the exact set of packages to be available and
3034 passes it @i{via} the @option{--manifest} option
3035 (@pxref{profile-manifest, @option{--manifest}}).
3038 For each user, a symlink to the user's default profile is automatically
3039 created in @file{$HOME/.guix-profile}. This symlink always points to the
3040 current generation of the user's default profile. Thus, users can add
3041 @file{$HOME/.guix-profile/bin} to their @env{PATH} environment
3042 variable, and so on.
3043 @cindex search paths
3044 If you are not using Guix System, consider adding the
3045 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
3046 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
3047 shells get all the right environment variable definitions:
3050 GUIX_PROFILE="$HOME/.guix-profile" ; \
3051 source "$HOME/.guix-profile/etc/profile"
3054 In a multi-user setup, user profiles are stored in a place registered as
3055 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
3056 to (@pxref{Invoking guix gc}). That directory is normally
3057 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
3058 @var{localstatedir} is the value passed to @code{configure} as
3059 @option{--localstatedir}, and @var{user} is the user name. The
3060 @file{per-user} directory is created when @command{guix-daemon} is
3061 started, and the @var{user} sub-directory is created by @command{guix
3064 The @var{options} can be among the following:
3068 @item --install=@var{package} @dots{}
3069 @itemx -i @var{package} @dots{}
3070 Install the specified @var{package}s.
3072 Each @var{package} may specify either a simple package name, such as
3073 @code{guile}, or a package name followed by an at-sign and version number,
3074 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
3075 case, the newest version prefixed by @code{1.8} is selected).
3077 If no version number is specified, the
3078 newest available version will be selected. In addition, @var{package}
3079 may contain a colon, followed by the name of one of the outputs of the
3080 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
3081 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
3082 name (and optionally version) are searched for among the GNU
3083 distribution modules (@pxref{Package Modules}).
3085 @cindex propagated inputs
3086 Sometimes packages have @dfn{propagated inputs}: these are dependencies
3087 that automatically get installed along with the required package
3088 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
3089 @code{package} objects}, for information about propagated inputs in
3090 package definitions).
3092 @anchor{package-cmd-propagated-inputs}
3093 An example is the GNU MPC library: its C header files refer to those of
3094 the GNU MPFR library, which in turn refer to those of the GMP library.
3095 Thus, when installing MPC, the MPFR and GMP libraries also get installed
3096 in the profile; removing MPC also removes MPFR and GMP---unless they had
3097 also been explicitly installed by the user.
3099 Besides, packages sometimes rely on the definition of environment
3100 variables for their search paths (see explanation of
3101 @option{--search-paths} below). Any missing or possibly incorrect
3102 environment variable definitions are reported here.
3104 @item --install-from-expression=@var{exp}
3106 Install the package @var{exp} evaluates to.
3108 @var{exp} must be a Scheme expression that evaluates to a
3109 @code{<package>} object. This option is notably useful to disambiguate
3110 between same-named variants of a package, with expressions such as
3111 @code{(@@ (gnu packages base) guile-final)}.
3113 Note that this option installs the first output of the specified
3114 package, which may be insufficient when needing a specific output of a
3115 multiple-output package.
3117 @item --install-from-file=@var{file}
3118 @itemx -f @var{file}
3119 Install the package that the code within @var{file} evaluates to.
3121 As an example, @var{file} might contain a definition like this
3122 (@pxref{Defining Packages}):
3125 @include package-hello.scm
3128 Developers may find it useful to include such a @file{guix.scm} file
3129 in the root of their project source tree that can be used to test
3130 development snapshots and create reproducible development environments
3131 (@pxref{Invoking guix environment}).
3133 The @var{file} may also contain a JSON representation of one or more
3134 package definitions. Running @code{guix package -f} on
3135 @file{hello.json} with the following contents would result in installing
3136 the package @code{greeter} after building @code{myhello}:
3139 @verbatiminclude package-hello.json
3142 @item --remove=@var{package} @dots{}
3143 @itemx -r @var{package} @dots{}
3144 Remove the specified @var{package}s.
3146 As for @option{--install}, each @var{package} may specify a version number
3147 and/or output name in addition to the package name. For instance,
3148 @samp{-r glibc:debug} would remove the @code{debug} output of
3151 @item --upgrade[=@var{regexp} @dots{}]
3152 @itemx -u [@var{regexp} @dots{}]
3153 @cindex upgrading packages
3154 Upgrade all the installed packages. If one or more @var{regexp}s are
3155 specified, upgrade only installed packages whose name matches a
3156 @var{regexp}. Also see the @option{--do-not-upgrade} option below.
3158 Note that this upgrades package to the latest version of packages found
3159 in the distribution currently installed. To update your distribution,
3160 you should regularly run @command{guix pull} (@pxref{Invoking guix
3163 @cindex package transformations, upgrades
3164 When upgrading, package transformations that were originally applied
3165 when creating the profile are automatically re-applied (@pxref{Package
3166 Transformation Options}). For example, assume you first installed Emacs
3167 from the tip of its development branch with:
3170 guix install emacs-next --with-branch=emacs-next=master
3173 Next time you run @command{guix upgrade}, Guix will again pull the tip
3174 of the Emacs development branch and build @code{emacs-next} from that
3177 Note that transformation options such as @option{--with-branch} and
3178 @option{--with-source} depend on external state; it is up to you to
3179 ensure that they work as expected. You can also discard a
3180 transformations that apply to a package by running:
3183 guix install @var{package}
3186 @item --do-not-upgrade[=@var{regexp} @dots{}]
3187 When used together with the @option{--upgrade} option, do @emph{not}
3188 upgrade any packages whose name matches a @var{regexp}. For example, to
3189 upgrade all packages in the current profile except those containing the
3190 substring ``emacs'':
3193 $ guix package --upgrade . --do-not-upgrade emacs
3196 @item @anchor{profile-manifest}--manifest=@var{file}
3197 @itemx -m @var{file}
3198 @cindex profile declaration
3199 @cindex profile manifest
3200 Create a new generation of the profile from the manifest object
3201 returned by the Scheme code in @var{file}. This option can be repeated
3202 several times, in which case the manifests are concatenated.
3204 This allows you to @emph{declare} the profile's contents rather than
3205 constructing it through a sequence of @option{--install} and similar
3206 commands. The advantage is that @var{file} can be put under version
3207 control, copied to different machines to reproduce the same profile, and
3210 @c FIXME: Add reference to (guix profile) documentation when available.
3211 @var{file} must return a @dfn{manifest} object, which is roughly a list
3214 @findex packages->manifest
3216 (use-package-modules guile emacs)
3221 ;; Use a specific package output.
3222 (list guile-2.0 "debug")))
3225 @findex specifications->manifest
3226 In this example we have to know which modules define the @code{emacs}
3227 and @code{guile-2.0} variables to provide the right
3228 @code{use-package-modules} line, which can be cumbersome. We can
3229 instead provide regular package specifications and let
3230 @code{specifications->manifest} look up the corresponding package
3234 (specifications->manifest
3235 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
3239 @cindex rolling back
3240 @cindex undoing transactions
3241 @cindex transactions, undoing
3242 Roll back to the previous @dfn{generation} of the profile---i.e., undo
3243 the last transaction.
3245 When combined with options such as @option{--install}, roll back occurs
3246 before any other actions.
3248 When rolling back from the first generation that actually contains
3249 installed packages, the profile is made to point to the @dfn{zeroth
3250 generation}, which contains no files apart from its own metadata.
3252 After having rolled back, installing, removing, or upgrading packages
3253 overwrites previous future generations. Thus, the history of the
3254 generations in a profile is always linear.
3256 @item --switch-generation=@var{pattern}
3257 @itemx -S @var{pattern}
3259 Switch to a particular generation defined by @var{pattern}.
3261 @var{pattern} may be either a generation number or a number prefixed
3262 with ``+'' or ``-''. The latter means: move forward/backward by a
3263 specified number of generations. For example, if you want to return to
3264 the latest generation after @option{--roll-back}, use
3265 @option{--switch-generation=+1}.
3267 The difference between @option{--roll-back} and
3268 @option{--switch-generation=-1} is that @option{--switch-generation} will
3269 not make a zeroth generation, so if a specified generation does not
3270 exist, the current generation will not be changed.
3272 @item --search-paths[=@var{kind}]
3273 @cindex search paths
3274 Report environment variable definitions, in Bash syntax, that may be
3275 needed in order to use the set of installed packages. These environment
3276 variables are used to specify @dfn{search paths} for files used by some
3277 of the installed packages.
3279 For example, GCC needs the @env{CPATH} and @env{LIBRARY_PATH}
3280 environment variables to be defined so it can look for headers and
3281 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
3282 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
3283 library are installed in the profile, then @option{--search-paths} will
3284 suggest setting these variables to @file{@var{profile}/include} and
3285 @file{@var{profile}/lib}, respectively.
3287 The typical use case is to define these environment variables in the
3291 $ eval `guix package --search-paths`
3294 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
3295 meaning that the returned environment variable definitions will either
3296 be exact settings, or prefixes or suffixes of the current value of these
3297 variables. When omitted, @var{kind} defaults to @code{exact}.
3299 This option can also be used to compute the @emph{combined} search paths
3300 of several profiles. Consider this example:
3303 $ guix package -p foo -i guile
3304 $ guix package -p bar -i guile-json
3305 $ guix package -p foo -p bar --search-paths
3308 The last command above reports about the @env{GUILE_LOAD_PATH}
3309 variable, even though, taken individually, neither @file{foo} nor
3310 @file{bar} would lead to that recommendation.
3313 @item --profile=@var{profile}
3314 @itemx -p @var{profile}
3315 Use @var{profile} instead of the user's default profile.
3317 @var{profile} must be the name of a file that will be created upon
3318 completion. Concretely, @var{profile} will be a mere symbolic link
3319 (``symlink'') pointing to the actual profile where packages are
3323 $ guix install hello -p ~/code/my-profile
3325 $ ~/code/my-profile/bin/hello
3329 All it takes to get rid of the profile is to remove this symlink and its
3330 siblings that point to specific generations:
3333 $ rm ~/code/my-profile ~/code/my-profile-*-link
3336 @item --list-profiles
3337 List all the user's profiles:
3340 $ guix package --list-profiles
3341 /home/charlie/.guix-profile
3342 /home/charlie/code/my-profile
3343 /home/charlie/code/devel-profile
3344 /home/charlie/tmp/test
3347 When running as root, list all the profiles of all the users.
3349 @cindex collisions, in a profile
3350 @cindex colliding packages in profiles
3351 @cindex profile collisions
3352 @item --allow-collisions
3353 Allow colliding packages in the new profile. Use at your own risk!
3355 By default, @command{guix package} reports as an error @dfn{collisions}
3356 in the profile. Collisions happen when two or more different versions
3357 or variants of a given package end up in the profile.
3360 Use the bootstrap Guile to build the profile. This option is only
3361 useful to distribution developers.
3365 In addition to these actions, @command{guix package} supports the
3366 following options to query the current state of a profile, or the
3367 availability of packages:
3371 @item --search=@var{regexp}
3372 @itemx -s @var{regexp}
3373 @anchor{guix-search}
3374 @cindex searching for packages
3375 List the available packages whose name, synopsis, or description matches
3376 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
3377 Print all the metadata of matching packages in
3378 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
3379 GNU recutils manual}).
3381 This allows specific fields to be extracted using the @command{recsel}
3382 command, for instance:
3385 $ guix package -s malloc | recsel -p name,version,relevance
3399 Similarly, to show the name of all the packages available under the
3400 terms of the GNU@tie{}LGPL version 3:
3403 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
3410 It is also possible to refine search results using several @code{-s} flags to
3411 @command{guix package}, or several arguments to @command{guix search}. For
3412 example, the following command returns a list of board games (this time using
3413 the @command{guix search} alias):
3416 $ guix search '\<board\>' game | recsel -p name
3421 If we were to omit @code{-s game}, we would also get software packages
3422 that deal with printed circuit boards; removing the angle brackets
3423 around @code{board} would further add packages that have to do with
3426 And now for a more elaborate example. The following command searches
3427 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
3428 libraries, and prints the name and synopsis of the matching packages:
3431 $ guix search crypto library | \
3432 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3436 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3437 information on @dfn{selection expressions} for @code{recsel -e}.
3439 @item --show=@var{package}
3440 Show details about @var{package}, taken from the list of available packages, in
3441 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3445 $ guix package --show=python | recsel -p name,version
3453 You may also specify the full name of a package to only get details about a
3454 specific version of it (this time using the @command{guix show} alias):
3456 $ guix show python@@3.4 | recsel -p name,version
3463 @item --list-installed[=@var{regexp}]
3464 @itemx -I [@var{regexp}]
3465 List the currently installed packages in the specified profile, with the
3466 most recently installed packages shown last. When @var{regexp} is
3467 specified, list only installed packages whose name matches @var{regexp}.
3469 For each installed package, print the following items, separated by
3470 tabs: the package name, its version string, the part of the package that
3471 is installed (for instance, @code{out} for the default output,
3472 @code{include} for its headers, etc.), and the path of this package in
3475 @item --list-available[=@var{regexp}]
3476 @itemx -A [@var{regexp}]
3477 List packages currently available in the distribution for this system
3478 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3479 available packages whose name matches @var{regexp}.
3481 For each package, print the following items separated by tabs: its name,
3482 its version string, the parts of the package (@pxref{Packages with
3483 Multiple Outputs}), and the source location of its definition.
3485 @item --list-generations[=@var{pattern}]
3486 @itemx -l [@var{pattern}]
3488 Return a list of generations along with their creation dates; for each
3489 generation, show the installed packages, with the most recently
3490 installed packages shown last. Note that the zeroth generation is never
3493 For each installed package, print the following items, separated by
3494 tabs: the name of a package, its version string, the part of the package
3495 that is installed (@pxref{Packages with Multiple Outputs}), and the
3496 location of this package in the store.
3498 When @var{pattern} is used, the command returns only matching
3499 generations. Valid patterns include:
3502 @item @emph{Integers and comma-separated integers}. Both patterns denote
3503 generation numbers. For instance, @option{--list-generations=1} returns
3506 And @option{--list-generations=1,8,2} outputs three generations in the
3507 specified order. Neither spaces nor trailing commas are allowed.
3509 @item @emph{Ranges}. @option{--list-generations=2..9} prints the
3510 specified generations and everything in between. Note that the start of
3511 a range must be smaller than its end.
3513 It is also possible to omit the endpoint. For example,
3514 @option{--list-generations=2..}, returns all generations starting from the
3517 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3518 or months by passing an integer along with the first letter of the
3519 duration. For example, @option{--list-generations=20d} lists generations
3520 that are up to 20 days old.
3523 @item --delete-generations[=@var{pattern}]
3524 @itemx -d [@var{pattern}]
3525 When @var{pattern} is omitted, delete all generations except the current
3528 This command accepts the same patterns as @option{--list-generations}.
3529 When @var{pattern} is specified, delete the matching generations. When
3530 @var{pattern} specifies a duration, generations @emph{older} than the
3531 specified duration match. For instance, @option{--delete-generations=1m}
3532 deletes generations that are more than one month old.
3534 If the current generation matches, it is @emph{not} deleted. Also, the
3535 zeroth generation is never deleted.
3537 Note that deleting generations prevents rolling back to them.
3538 Consequently, this command must be used with care.
3542 Finally, since @command{guix package} may actually start build
3543 processes, it supports all the common build options (@pxref{Common Build
3544 Options}). It also supports package transformation options, such as
3545 @option{--with-source} (@pxref{Package Transformation Options}).
3546 However, note that package transformations are lost when upgrading; to
3547 preserve transformations across upgrades, you should define your own
3548 package variant in a Guile module and add it to @env{GUIX_PACKAGE_PATH}
3549 (@pxref{Defining Packages}).
3552 @section Substitutes
3555 @cindex pre-built binaries
3556 Guix supports transparent source/binary deployment, which means that it
3557 can either build things locally, or download pre-built items from a
3558 server, or both. We call these pre-built items @dfn{substitutes}---they
3559 are substitutes for local build results. In many cases, downloading a
3560 substitute is much faster than building things locally.
3562 Substitutes can be anything resulting from a derivation build
3563 (@pxref{Derivations}). Of course, in the common case, they are
3564 pre-built package binaries, but source tarballs, for instance, which
3565 also result from derivation builds, can be available as substitutes.
3568 * Official Substitute Server:: One particular source of substitutes.
3569 * Substitute Server Authorization:: How to enable or disable substitutes.
3570 * Getting Substitutes from Other Servers:: Substitute diversity.
3571 * Substitute Authentication:: How Guix verifies substitutes.
3572 * Proxy Settings:: How to get substitutes via proxy.
3573 * Substitution Failure:: What happens when substitution fails.
3574 * On Trusting Binaries:: How can you trust that binary blob?
3577 @node Official Substitute Server
3578 @subsection Official Substitute Server
3581 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3582 that builds packages from Guix continuously for some
3583 architectures, and makes them available as substitutes. This is the
3584 default source of substitutes; it can be overridden by passing the
3585 @option{--substitute-urls} option either to @command{guix-daemon}
3586 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3587 or to client tools such as @command{guix package}
3588 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3591 Substitute URLs can be either HTTP or HTTPS.
3592 HTTPS is recommended because communications are encrypted; conversely,
3593 using HTTP makes all communications visible to an eavesdropper, who
3594 could use the information gathered to determine, for instance, whether
3595 your system has unpatched security vulnerabilities.
3597 Substitutes from the official build farm are enabled by default when
3598 using Guix System (@pxref{GNU Distribution}). However,
3599 they are disabled by default when using Guix on a foreign distribution,
3600 unless you have explicitly enabled them via one of the recommended
3601 installation steps (@pxref{Installation}). The following paragraphs
3602 describe how to enable or disable substitutes for the official build
3603 farm; the same procedure can also be used to enable substitutes for any
3604 other substitute server.
3606 @node Substitute Server Authorization
3607 @subsection Substitute Server Authorization
3610 @cindex substitutes, authorization thereof
3611 @cindex access control list (ACL), for substitutes
3612 @cindex ACL (access control list), for substitutes
3613 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3615 must add its public key to the access control list (ACL) of archive
3616 imports, using the @command{guix archive} command (@pxref{Invoking guix
3617 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3618 be compromised and to serve genuine substitutes.
3621 If you are using Guix System, you can skip this section: Guix System
3622 authorizes substitutes from @code{@value{SUBSTITUTE-SERVER}} by default.
3625 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3626 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3627 the installation prefix of Guix. If you installed Guix from source,
3628 make sure you checked the GPG signature of
3629 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3630 Then, you can run something like this:
3633 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3636 Once this is in place, the output of a command like @code{guix build}
3637 should change from something like:
3640 $ guix build emacs --dry-run
3641 The following derivations would be built:
3642 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3643 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3644 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3645 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3653 $ guix build emacs --dry-run
3654 112.3 MB would be downloaded:
3655 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3656 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3657 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3658 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3663 The text changed from ``The following derivations would be built'' to
3664 ``112.3 MB would be downloaded''. This indicates that substitutes from
3665 @code{@value{SUBSTITUTE-SERVER}} are usable and will be downloaded, when
3666 possible, for future builds.
3668 @cindex substitutes, how to disable
3669 The substitute mechanism can be disabled globally by running
3670 @code{guix-daemon} with @option{--no-substitutes} (@pxref{Invoking
3671 guix-daemon}). It can also be disabled temporarily by passing the
3672 @option{--no-substitutes} option to @command{guix package},
3673 @command{guix build}, and other command-line tools.
3675 @node Getting Substitutes from Other Servers
3676 @subsection Getting Substitutes from Other Servers
3678 @cindex substitute servers, adding more
3679 Guix can look up and fetch substitutes from several servers. This is
3680 useful when you are using packages from additional channels for which
3681 the official server does not have substitutes but another server
3682 provides them. Another situation where this is useful is when you would
3683 prefer to download from your organization's substitute server, resorting
3684 to the official server only as a fallback or dismissing it altogether.
3686 You can give Guix a list of substitute server URLs and it will check
3687 them in the specified order. You also need to explicitly authorize the
3688 public keys of substitute servers to instruct Guix to accept the
3689 substitutes they sign.
3691 On Guix System, this is achieved by modifying the configuration of the
3692 @code{guix} service. Since the @code{guix} service is part of the
3693 default lists of services, @code{%base-services} and
3694 @code{%desktop-services}, you can use @code{modify-services} to change
3695 its configuration and add the URLs and substitute keys that you want
3696 (@pxref{Service Reference, @code{modify-services}}).
3698 As an example, suppose you want to fetch substitutes from
3699 @code{guix.example.org} and to authorize the signing key of that server,
3700 in addition to the default @code{@value{SUBSTITUTE-SERVER}}. The
3701 resulting operating system configuration will look something like:
3707 ;; Assume we're starting from '%desktop-services'. Replace it
3708 ;; with the list of services you're actually using.
3709 (modify-services %desktop-services
3710 (guix-service-type config =>
3714 (append (list "https://guix.example.org")
3715 %default-substitute-urls))
3717 (append (list (local-file "./key.pub"))
3718 %default-authorized-guix-keys)))))))
3721 This assumes that the file @file{key.pub} contains the signing key of
3722 @code{guix.example.org}. With this change in place in your operating
3723 system configuration file (say @file{/etc/config.scm}), you can
3724 reconfigure and restart the @code{guix-daemon} service or reboot so the
3725 changes take effect:
3728 $ sudo guix system reconfigure /etc/config.scm
3729 $ sudo herd restart guix-daemon
3732 If you're running Guix on a ``foreign distro'', you would instead take
3733 the following steps to get substitutes from additional servers:
3737 Edit the service configuration file for @code{guix-daemon}; when using
3738 systemd, this is normally
3739 @file{/etc/systemd/system/guix-daemon.service}. Add the
3740 @option{--substitute-urls} option on the @command{guix-daemon} command
3741 line and list the URLs of interest (@pxref{daemon-substitute-urls,
3742 @code{guix-daemon --substitute-urls}}):
3745 @dots{} --substitute-urls='https://guix.example.org https://@value{SUBSTITUTE-SERVER}'
3749 Restart the daemon. For systemd, it goes like this:
3752 systemctl daemon-reload
3753 systemctl restart guix-daemon.service
3757 Authorize the key of the new server (@pxref{Invoking guix archive}):
3760 guix archive --authorize < key.pub
3763 Again this assumes @file{key.pub} contains the public key that
3764 @code{guix.example.org} uses to sign substitutes.
3767 Now you're all set! Substitutes will be preferably taken from
3768 @code{https://guix.example.org}, using @code{@value{SUBSTITUTE-SERVER}}
3769 as a fallback. Of course you can list as many substitute servers as you
3770 like, with the caveat that substitute lookup can be slowed down if too
3771 many servers need to be contacted.
3773 Note that there are also situations where one may want to add the URL of
3774 a substitute server @emph{without} authorizing its key.
3775 @xref{Substitute Authentication}, to understand this fine point.
3777 @node Substitute Authentication
3778 @subsection Substitute Authentication
3780 @cindex digital signatures
3781 Guix detects and raises an error when attempting to use a substitute
3782 that has been tampered with. Likewise, it ignores substitutes that are
3783 not signed, or that are not signed by one of the keys listed in the ACL.
3785 There is one exception though: if an unauthorized server provides
3786 substitutes that are @emph{bit-for-bit identical} to those provided by
3787 an authorized server, then the unauthorized server becomes eligible for
3788 downloads. For example, assume we have chosen two substitute servers
3792 --substitute-urls="https://a.example.org https://b.example.org"
3796 @cindex reproducible builds
3797 If the ACL contains only the key for @samp{b.example.org}, and if
3798 @samp{a.example.org} happens to serve the @emph{exact same} substitutes,
3799 then Guix will download substitutes from @samp{a.example.org} because it
3800 comes first in the list and can be considered a mirror of
3801 @samp{b.example.org}. In practice, independent build machines usually
3802 produce the same binaries, thanks to bit-reproducible builds (see
3805 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3806 (in other words, the server is not authenticated), contrary to what
3807 HTTPS clients such as Web browsers usually do. This is because Guix
3808 authenticates substitute information itself, as explained above, which
3809 is what we care about (whereas X.509 certificates are about
3810 authenticating bindings between domain names and public keys).
3812 @node Proxy Settings
3813 @subsection Proxy Settings
3817 Substitutes are downloaded over HTTP or HTTPS. The @env{http_proxy} and
3818 @env{https_proxy} environment variables can be set in the environment of
3819 @command{guix-daemon} and are honored for downloads of substitutes.
3820 Note that the value of those environment variables in the environment
3821 where @command{guix build}, @command{guix package}, and other client
3822 commands are run has @emph{absolutely no effect}.
3824 @node Substitution Failure
3825 @subsection Substitution Failure
3827 Even when a substitute for a derivation is available, sometimes the
3828 substitution attempt will fail. This can happen for a variety of
3829 reasons: the substitute server might be offline, the substitute may
3830 recently have been deleted, the connection might have been interrupted,
3833 When substitutes are enabled and a substitute for a derivation is
3834 available, but the substitution attempt fails, Guix will attempt to
3835 build the derivation locally depending on whether or not
3836 @option{--fallback} was given (@pxref{fallback-option,, common build
3837 option @option{--fallback}}). Specifically, if @option{--fallback} was
3838 omitted, then no local build will be performed, and the derivation is
3839 considered to have failed. However, if @option{--fallback} was given,
3840 then Guix will attempt to build the derivation locally, and the success
3841 or failure of the derivation depends on the success or failure of the
3842 local build. Note that when substitutes are disabled or no substitute
3843 is available for the derivation in question, a local build will
3844 @emph{always} be performed, regardless of whether or not
3845 @option{--fallback} was given.
3847 To get an idea of how many substitutes are available right now, you can
3848 try running the @command{guix weather} command (@pxref{Invoking guix
3849 weather}). This command provides statistics on the substitutes provided
3852 @node On Trusting Binaries
3853 @subsection On Trusting Binaries
3855 @cindex trust, of pre-built binaries
3856 Today, each individual's control over their own computing is at the
3857 mercy of institutions, corporations, and groups with enough power and
3858 determination to subvert the computing infrastructure and exploit its
3859 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3860 convenient, we encourage users to also build on their own, or even run
3861 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3862 interesting target. One way to help is by publishing the software you
3863 build using @command{guix publish} so that others have one more choice
3864 of server to download substitutes from (@pxref{Invoking guix publish}).
3866 Guix has the foundations to maximize build reproducibility
3867 (@pxref{Features}). In most cases, independent builds of a given
3868 package or derivation should yield bit-identical results. Thus, through
3869 a diverse set of independent package builds, we can strengthen the
3870 integrity of our systems. The @command{guix challenge} command aims to
3871 help users assess substitute servers, and to assist developers in
3872 finding out about non-deterministic package builds (@pxref{Invoking guix
3873 challenge}). Similarly, the @option{--check} option of @command{guix
3874 build} allows users to check whether previously-installed substitutes
3875 are genuine by rebuilding them locally (@pxref{build-check,
3876 @command{guix build --check}}).
3878 In the future, we want Guix to have support to publish and retrieve
3879 binaries to/from other users, in a peer-to-peer fashion. If you would
3880 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3882 @node Packages with Multiple Outputs
3883 @section Packages with Multiple Outputs
3885 @cindex multiple-output packages
3886 @cindex package outputs
3889 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3890 source package leads to exactly one directory in the store. When running
3891 @command{guix install glibc}, one installs the default output of the
3892 GNU libc package; the default output is called @code{out}, but its name
3893 can be omitted as shown in this command. In this particular case, the
3894 default output of @code{glibc} contains all the C header files, shared
3895 libraries, static libraries, Info documentation, and other supporting
3898 Sometimes it is more appropriate to separate the various types of files
3899 produced from a single source package into separate outputs. For
3900 instance, the GLib C library (used by GTK+ and related packages)
3901 installs more than 20 MiB of reference documentation as HTML pages.
3902 To save space for users who do not need it, the documentation goes to a
3903 separate output, called @code{doc}. To install the main GLib output,
3904 which contains everything but the documentation, one would run:
3910 @cindex documentation
3911 The command to install its documentation is:
3914 guix install glib:doc
3917 Some packages install programs with different ``dependency footprints''.
3918 For instance, the WordNet package installs both command-line tools and
3919 graphical user interfaces (GUIs). The former depend solely on the C
3920 library, whereas the latter depend on Tcl/Tk and the underlying X
3921 libraries. In this case, we leave the command-line tools in the default
3922 output, whereas the GUIs are in a separate output. This allows users
3923 who do not need the GUIs to save space. The @command{guix size} command
3924 can help find out about such situations (@pxref{Invoking guix size}).
3925 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3927 There are several such multiple-output packages in the GNU distribution.
3928 Other conventional output names include @code{lib} for libraries and
3929 possibly header files, @code{bin} for stand-alone programs, and
3930 @code{debug} for debugging information (@pxref{Installing Debugging
3931 Files}). The outputs of a packages are listed in the third column of
3932 the output of @command{guix package --list-available} (@pxref{Invoking
3936 @node Invoking guix gc
3937 @section Invoking @command{guix gc}
3939 @cindex garbage collector
3941 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3942 The @command{guix gc} command allows users to explicitly run the garbage
3943 collector to reclaim space from the @file{/gnu/store} directory. It is
3944 the @emph{only} way to remove files from @file{/gnu/store}---removing
3945 files or directories manually may break it beyond repair!
3948 @cindex garbage collector roots
3949 The garbage collector has a set of known @dfn{roots}: any file under
3950 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3951 cannot be deleted; any other file is considered @dfn{dead} and may be
3952 deleted. The set of garbage collector roots (``GC roots'' for short)
3953 includes default user profiles; by default, the symlinks under
3954 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3955 added with @command{guix build --root}, for example (@pxref{Invoking
3956 guix build}). The @command{guix gc --list-roots} command lists them.
3958 Prior to running @code{guix gc --collect-garbage} to make space, it is
3959 often useful to remove old generations from user profiles; that way, old
3960 package builds referenced by those generations can be reclaimed. This
3961 is achieved by running @code{guix package --delete-generations}
3962 (@pxref{Invoking guix package}).
3964 Our recommendation is to run a garbage collection periodically, or when
3965 you are short on disk space. For instance, to guarantee that at least
3966 5@tie{}GB are available on your disk, simply run:
3972 It is perfectly safe to run as a non-interactive periodic job
3973 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3974 Running @command{guix gc} with no arguments will collect as
3975 much garbage as it can, but that is often inconvenient: you may find
3976 yourself having to rebuild or re-download software that is ``dead'' from
3977 the GC viewpoint but that is necessary to build other pieces of
3978 software---e.g., the compiler tool chain.
3980 The @command{guix gc} command has three modes of operation: it can be
3981 used to garbage-collect any dead files (the default), to delete specific
3982 files (the @option{--delete} option), to print garbage-collector
3983 information, or for more advanced queries. The garbage collection
3984 options are as follows:
3987 @item --collect-garbage[=@var{min}]
3988 @itemx -C [@var{min}]
3989 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3990 sub-directories. This is the default operation when no option is
3993 When @var{min} is given, stop once @var{min} bytes have been collected.
3994 @var{min} may be a number of bytes, or it may include a unit as a
3995 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3996 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3998 When @var{min} is omitted, collect all the garbage.
4000 @item --free-space=@var{free}
4001 @itemx -F @var{free}
4002 Collect garbage until @var{free} space is available under
4003 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
4004 as @code{500MiB}, as described above.
4006 When @var{free} or more is already available in @file{/gnu/store}, do
4007 nothing and exit immediately.
4009 @item --delete-generations[=@var{duration}]
4010 @itemx -d [@var{duration}]
4011 Before starting the garbage collection process, delete all the generations
4012 older than @var{duration}, for all the user profiles; when run as root, this
4013 applies to all the profiles @emph{of all the users}.
4015 For example, this command deletes all the generations of all your profiles
4016 that are older than 2 months (except generations that are current), and then
4017 proceeds to free space until at least 10 GiB are available:
4020 guix gc -d 2m -F 10G
4025 Attempt to delete all the store files and directories specified as
4026 arguments. This fails if some of the files are not in the store, or if
4027 they are still live.
4029 @item --list-failures
4030 List store items corresponding to cached build failures.
4032 This prints nothing unless the daemon was started with
4033 @option{--cache-failures} (@pxref{Invoking guix-daemon,
4034 @option{--cache-failures}}).
4037 List the GC roots owned by the user; when run as root, list @emph{all} the GC
4041 List store items in use by currently running processes. These store
4042 items are effectively considered GC roots: they cannot be deleted.
4044 @item --clear-failures
4045 Remove the specified store items from the failed-build cache.
4047 Again, this option only makes sense when the daemon is started with
4048 @option{--cache-failures}. Otherwise, it does nothing.
4051 Show the list of dead files and directories still present in the
4052 store---i.e., files and directories no longer reachable from any root.
4055 Show the list of live store files and directories.
4059 In addition, the references among existing store files can be queried:
4065 @cindex package dependencies
4066 List the references (respectively, the referrers) of store files given
4072 List the requisites of the store files passed as arguments. Requisites
4073 include the store files themselves, their references, and the references
4074 of these, recursively. In other words, the returned list is the
4075 @dfn{transitive closure} of the store files.
4077 @xref{Invoking guix size}, for a tool to profile the size of the closure
4078 of an element. @xref{Invoking guix graph}, for a tool to visualize
4079 the graph of references.
4083 Return the derivation(s) leading to the given store items
4084 (@pxref{Derivations}).
4086 For example, this command:
4089 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
4093 returns the @file{.drv} file(s) leading to the @code{emacs} package
4094 installed in your profile.
4096 Note that there may be zero matching @file{.drv} files, for instance
4097 because these files have been garbage-collected. There can also be more
4098 than one matching @file{.drv} due to fixed-output derivations.
4101 Lastly, the following options allow you to check the integrity of the
4102 store and to control disk usage.
4106 @item --verify[=@var{options}]
4107 @cindex integrity, of the store
4108 @cindex integrity checking
4109 Verify the integrity of the store.
4111 By default, make sure that all the store items marked as valid in the
4112 database of the daemon actually exist in @file{/gnu/store}.
4114 When provided, @var{options} must be a comma-separated list containing one
4115 or more of @code{contents} and @code{repair}.
4117 When passing @option{--verify=contents}, the daemon computes the
4118 content hash of each store item and compares it against its hash in the
4119 database. Hash mismatches are reported as data corruptions. Because it
4120 traverses @emph{all the files in the store}, this command can take a
4121 long time, especially on systems with a slow disk drive.
4123 @cindex repairing the store
4124 @cindex corruption, recovering from
4125 Using @option{--verify=repair} or @option{--verify=contents,repair}
4126 causes the daemon to try to repair corrupt store items by fetching
4127 substitutes for them (@pxref{Substitutes}). Because repairing is not
4128 atomic, and thus potentially dangerous, it is available only to the
4129 system administrator. A lightweight alternative, when you know exactly
4130 which items in the store are corrupt, is @command{guix build --repair}
4131 (@pxref{Invoking guix build}).
4134 @cindex deduplication
4135 Optimize the store by hard-linking identical files---this is
4136 @dfn{deduplication}.
4138 The daemon performs deduplication after each successful build or archive
4139 import, unless it was started with @option{--disable-deduplication}
4140 (@pxref{Invoking guix-daemon, @option{--disable-deduplication}}). Thus,
4141 this option is primarily useful when the daemon was running with
4142 @option{--disable-deduplication}.
4146 @node Invoking guix pull
4147 @section Invoking @command{guix pull}
4149 @cindex upgrading Guix
4150 @cindex updating Guix
4151 @cindex @command{guix pull}
4153 @cindex security, @command{guix pull}
4154 @cindex authenticity, of code obtained with @command{guix pull}
4155 Packages are installed or upgraded to the latest version available in
4156 the distribution currently available on your local machine. To update
4157 that distribution, along with the Guix tools, you must run @command{guix
4158 pull}: the command downloads the latest Guix source code and package
4159 descriptions, and deploys it. Source code is downloaded from a
4160 @uref{https://git-scm.com, Git} repository, by default the official
4161 GNU@tie{}Guix repository, though this can be customized. @command{guix
4162 pull} ensures that the code it downloads is @emph{authentic} by
4163 verifying that commits are signed by Guix developers.
4165 Specifically, @command{guix pull} downloads code from the @dfn{channels}
4166 (@pxref{Channels}) specified by one of the followings, in this order:
4170 the @option{--channels} option;
4172 the user's @file{~/.config/guix/channels.scm} file;
4174 the system-wide @file{/etc/guix/channels.scm} file;
4176 the built-in default channels specified in the @code{%default-channels}
4180 On completion, @command{guix package} will use packages and package
4181 versions from this just-retrieved copy of Guix. Not only that, but all
4182 the Guix commands and Scheme modules will also be taken from that latest
4183 version. New @command{guix} sub-commands added by the update also
4186 Any user can update their Guix copy using @command{guix pull}, and the
4187 effect is limited to the user who ran @command{guix pull}. For
4188 instance, when user @code{root} runs @command{guix pull}, this has no
4189 effect on the version of Guix that user @code{alice} sees, and vice
4192 The result of running @command{guix pull} is a @dfn{profile} available
4193 under @file{~/.config/guix/current} containing the latest Guix. Thus,
4194 make sure to add it to the beginning of your search path so that you use
4195 the latest version, and similarly for the Info manual
4196 (@pxref{Documentation}):
4199 export PATH="$HOME/.config/guix/current/bin:$PATH"
4200 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
4203 The @option{--list-generations} or @option{-l} option lists past generations
4204 produced by @command{guix pull}, along with details about their provenance:
4208 Generation 1 Jun 10 2018 00:18:18
4210 repository URL: https://git.savannah.gnu.org/git/guix.git
4211 branch: origin/master
4212 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
4214 Generation 2 Jun 11 2018 11:02:49
4216 repository URL: https://git.savannah.gnu.org/git/guix.git
4217 branch: origin/master
4218 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
4219 2 new packages: keepalived, libnfnetlink
4220 6 packages upgraded: emacs-nix-mode@@2.0.4,
4221 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
4222 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
4224 Generation 3 Jun 13 2018 23:31:07 (current)
4226 repository URL: https://git.savannah.gnu.org/git/guix.git
4227 branch: origin/master
4228 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
4229 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
4230 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
4233 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
4234 describe the current status of Guix.
4236 This @code{~/.config/guix/current} profile works exactly like the profiles
4237 created by @command{guix package} (@pxref{Invoking guix package}). That
4238 is, you can list generations, roll back to the previous
4239 generation---i.e., the previous Guix---and so on:
4242 $ guix pull --roll-back
4243 switched from generation 3 to 2
4244 $ guix pull --delete-generations=1
4245 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
4248 You can also use @command{guix package} (@pxref{Invoking guix package})
4249 to manage the profile by naming it explicitly:
4251 $ guix package -p ~/.config/guix/current --roll-back
4252 switched from generation 3 to 2
4253 $ guix package -p ~/.config/guix/current --delete-generations=1
4254 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
4257 The @command{guix pull} command is usually invoked with no arguments,
4258 but it supports the following options:
4261 @item --url=@var{url}
4262 @itemx --commit=@var{commit}
4263 @itemx --branch=@var{branch}
4264 Download code for the @code{guix} channel from the specified @var{url}, at the
4265 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4266 string), or @var{branch}.
4268 @cindex @file{channels.scm}, configuration file
4269 @cindex configuration file for channels
4270 These options are provided for convenience, but you can also specify your
4271 configuration in the @file{~/.config/guix/channels.scm} file or using the
4272 @option{--channels} option (see below).
4274 @item --channels=@var{file}
4275 @itemx -C @var{file}
4276 Read the list of channels from @var{file} instead of
4277 @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
4278 @var{file} must contain Scheme code that
4279 evaluates to a list of channel objects. @xref{Channels}, for more
4282 @cindex channel news
4285 Display the list of packages added or upgraded since the previous
4286 generation, as well as, occasionally, news written by channel authors
4287 for their users (@pxref{Channels, Writing Channel News}).
4289 The package information is the same as displayed upon @command{guix
4290 pull} completion, but without ellipses; it is also similar to the output
4291 of @command{guix pull -l} for the last generation (see below).
4293 @item --list-generations[=@var{pattern}]
4294 @itemx -l [@var{pattern}]
4295 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
4296 is provided, the subset of generations that match @var{pattern}.
4297 The syntax of @var{pattern} is the same as with @code{guix package
4298 --list-generations} (@pxref{Invoking guix package}).
4301 @cindex rolling back
4302 @cindex undoing transactions
4303 @cindex transactions, undoing
4304 Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
4305 undo the last transaction.
4307 @item --switch-generation=@var{pattern}
4308 @itemx -S @var{pattern}
4310 Switch to a particular generation defined by @var{pattern}.
4312 @var{pattern} may be either a generation number or a number prefixed
4313 with ``+'' or ``-''. The latter means: move forward/backward by a
4314 specified number of generations. For example, if you want to return to
4315 the latest generation after @option{--roll-back}, use
4316 @option{--switch-generation=+1}.
4318 @item --delete-generations[=@var{pattern}]
4319 @itemx -d [@var{pattern}]
4320 When @var{pattern} is omitted, delete all generations except the current
4323 This command accepts the same patterns as @option{--list-generations}.
4324 When @var{pattern} is specified, delete the matching generations. When
4325 @var{pattern} specifies a duration, generations @emph{older} than the
4326 specified duration match. For instance, @option{--delete-generations=1m}
4327 deletes generations that are more than one month old.
4329 If the current generation matches, it is @emph{not} deleted.
4331 Note that deleting generations prevents rolling back to them.
4332 Consequently, this command must be used with care.
4334 @xref{Invoking guix describe}, for a way to display information about the
4335 current generation only.
4337 @item --profile=@var{profile}
4338 @itemx -p @var{profile}
4339 Use @var{profile} instead of @file{~/.config/guix/current}.
4343 Show which channel commit(s) would be used and what would be built or
4344 substituted but do not actually do it.
4346 @item --allow-downgrades
4347 Allow pulling older or unrelated revisions of channels than those
4350 @cindex downgrade attacks, protection against
4351 By default, @command{guix pull} protects against so-called ``downgrade
4352 attacks'' whereby the Git repository of a channel would be reset to an
4353 earlier or unrelated revision of itself, potentially leading you to
4354 install older, known-vulnerable versions of software packages.
4357 Make sure you understand its security implications before using
4358 @option{--allow-downgrades}.
4361 @item --disable-authentication
4362 Allow pulling channel code without authenticating it.
4364 @cindex authentication, of channel code
4365 By default, @command{guix pull} authenticates code downloaded from
4366 channels by verifying that its commits are signed by authorized
4367 developers, and raises an error if this is not the case. This option
4368 instructs it to not perform any such verification.
4371 Make sure you understand its security implications before using
4372 @option{--disable-authentication}.
4375 @item --system=@var{system}
4376 @itemx -s @var{system}
4377 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
4378 the system type of the build host.
4381 Use the bootstrap Guile to build the latest Guix. This option is only
4382 useful to Guix developers.
4385 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
4386 repository and branch to pull from, as well as @emph{additional} repositories
4387 containing package modules that should be deployed. @xref{Channels}, for more
4390 In addition, @command{guix pull} supports all the common build options
4391 (@pxref{Common Build Options}).
4393 @node Invoking guix time-machine
4394 @section Invoking @command{guix time-machine}
4396 @cindex @command{guix time-machine}
4397 @cindex pinning, channels
4398 @cindex replicating Guix
4399 @cindex reproducibility, of Guix
4401 The @command{guix time-machine} command provides access to other
4402 revisions of Guix, for example to install older versions of packages,
4403 or to reproduce a computation in an identical environment. The revision
4404 of Guix to be used is defined by a commit or by a channel
4405 description file created by @command{guix describe}
4406 (@pxref{Invoking guix describe}).
4408 The general syntax is:
4411 guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
4414 where @var{command} and @var{arg}@dots{} are passed unmodified to the
4415 @command{guix} command of the specified revision. The @var{options} that define
4416 this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
4419 @item --url=@var{url}
4420 @itemx --commit=@var{commit}
4421 @itemx --branch=@var{branch}
4422 Use the @code{guix} channel from the specified @var{url}, at the
4423 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4424 string), or @var{branch}.
4426 @item --channels=@var{file}
4427 @itemx -C @var{file}
4428 Read the list of channels from @var{file}. @var{file} must contain
4429 Scheme code that evaluates to a list of channel objects.
4430 @xref{Channels} for more information.
4433 As for @command{guix pull}, the absence of any options means that the
4434 latest commit on the master branch will be used. The command
4437 guix time-machine -- build hello
4440 will thus build the package @code{hello} as defined in the master branch,
4441 which is in general a newer revision of Guix than you have installed.
4442 Time travel works in both directions!
4444 Note that @command{guix time-machine} can trigger builds of channels and
4445 their dependencies, and these are controlled by the standard build
4446 options (@pxref{Common Build Options}).
4451 @c TODO: Remove this once we're more confident about API stability.
4453 The functionality described here is a ``technology preview'' as of version
4454 @value{VERSION}. As such, the interface is subject to change.
4458 @cindex composition of Guix revisions
4459 Sometimes you might need to mix packages from the revision of Guix you're
4460 currently running with packages available in a different revision of Guix.
4461 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
4462 revisions in arbitrary ways.
4464 @cindex inferior packages
4465 Technically, an ``inferior'' is essentially a separate Guix process connected
4466 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4467 @code{(guix inferior)} module allows you to create inferiors and to
4468 communicate with them. It also provides a high-level interface to browse and
4469 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4471 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4472 to interact with a separate revision of Guix. For example, let's assume you
4473 want to install in your profile the current @code{guile} package, along with
4474 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4475 because the newer @code{guile-json} has an incompatible API and you want to
4476 run your code against the old API@. To do that, you could write a manifest for
4477 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4478 manifest, you would create an inferior for that old Guix revision you care
4479 about, and you would look up the @code{guile-json} package in the inferior:
4482 (use-modules (guix inferior) (guix channels)
4483 (srfi srfi-1)) ;for 'first'
4486 ;; This is the old revision from which we want to
4487 ;; extract guile-json.
4490 (url "https://git.savannah.gnu.org/git/guix.git")
4492 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4495 ;; An inferior representing the above revision.
4496 (inferior-for-channels channels))
4498 ;; Now create a manifest with the current "guile" package
4499 ;; and the old "guile-json" package.
4501 (list (first (lookup-inferior-packages inferior "guile-json"))
4502 (specification->package "guile")))
4505 On its first run, @command{guix package --manifest} might have to build the
4506 channel you specified before it can create the inferior; subsequent runs will
4507 be much faster because the Guix revision will be cached.
4509 The @code{(guix inferior)} module provides the following procedures to open an
4512 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4513 [#:cache-directory] [#:ttl]
4514 Return an inferior for @var{channels}, a list of channels. Use the cache at
4515 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4516 This procedure opens a new connection to the build daemon.
4518 As a side effect, this procedure may build or substitute binaries for
4519 @var{channels}, which can take time.
4522 @deffn {Scheme Procedure} open-inferior @var{directory} @
4523 [#:command "bin/guix"]
4524 Open the inferior Guix in @var{directory}, running
4525 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4526 the inferior could not be launched.
4529 @cindex inferior packages
4530 The procedures listed below allow you to obtain and manipulate inferior
4533 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4534 Return the list of packages known to @var{inferior}.
4537 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4539 Return the sorted list of inferior packages matching @var{name} in
4540 @var{inferior}, with highest version numbers first. If @var{version} is true,
4541 return only packages with a version number prefixed by @var{version}.
4544 @deffn {Scheme Procedure} inferior-package? @var{obj}
4545 Return true if @var{obj} is an inferior package.
4548 @deffn {Scheme Procedure} inferior-package-name @var{package}
4549 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4550 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4551 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4552 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4553 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4554 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4555 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4556 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4557 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4558 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4559 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4560 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4561 These procedures are the counterpart of package record accessors
4562 (@pxref{package Reference}). Most of them work by querying the inferior
4563 @var{package} comes from, so the inferior must still be live when you call
4567 Inferior packages can be used transparently like any other package or
4568 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4569 transparently handled by the @code{packages->manifest} procedure, which is
4570 commonly use in manifests (@pxref{Invoking guix package, the
4571 @option{--manifest} option of @command{guix package}}). Thus you can insert
4572 an inferior package pretty much anywhere you would insert a regular package:
4573 in manifests, in the @code{packages} field of your @code{operating-system}
4574 declaration, and so on.
4576 @node Invoking guix describe
4577 @section Invoking @command{guix describe}
4579 @cindex reproducibility
4580 @cindex replicating Guix
4581 Often you may want to answer questions like: ``Which revision of Guix am I
4582 using?'' or ``Which channels am I using?'' This is useful information in many
4583 situations: if you want to @emph{replicate} an environment on a different
4584 machine or user account, if you want to report a bug or to determine what
4585 change in the channels you are using caused it, or if you want to record your
4586 system state for reproducibility purposes. The @command{guix describe}
4587 command answers these questions.
4589 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4590 displays the channel(s) that it was built from, including their repository URL
4591 and commit IDs (@pxref{Channels}):
4595 Generation 10 Sep 03 2018 17:32:44 (current)
4597 repository URL: https://git.savannah.gnu.org/git/guix.git
4599 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4602 If you're familiar with the Git version control system, this is similar in
4603 spirit to @command{git describe}; the output is also similar to that of
4604 @command{guix pull --list-generations}, but limited to the current generation
4605 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4606 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4607 information is all it takes to describe the revision of Guix you're using, and
4608 also to replicate it.
4610 To make it easier to replicate Guix, @command{guix describe} can also be asked
4611 to return a list of channels instead of the human-readable description above:
4614 $ guix describe -f channels
4617 (url "https://git.savannah.gnu.org/git/guix.git")
4619 "e0fa68c7718fffd33d81af415279d6ddb518f727")
4621 (make-channel-introduction
4622 "9edb3f66fd807b096b48283debdcddccfea34bad"
4623 (openpgp-fingerprint
4624 "BBB0 2DDF 2CEA F6A8 0D1D E643 A2A0 6DF2 A33A 54FA")))))
4628 You can save this to a file and feed it to @command{guix pull -C} on some
4629 other machine or at a later point in time, which will instantiate @emph{this
4630 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4631 From there on, since you're able to deploy the same revision of Guix, you can
4632 just as well @emph{replicate a complete software environment}. We humbly
4633 think that this is @emph{awesome}, and we hope you'll like it too!
4635 The details of the options supported by @command{guix describe} are as
4639 @item --format=@var{format}
4640 @itemx -f @var{format}
4641 Produce output in the specified @var{format}, one of:
4645 produce human-readable output;
4647 produce a list of channel specifications that can be passed to @command{guix
4648 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4650 @item channels-sans-intro
4651 like @code{channels}, but omit the @code{introduction} field; use it to
4652 produce a channel specification suitable for Guix version 1.1.0 or
4653 earlier---the @code{introduction} field has to do with channel
4654 authentication (@pxref{Channels, Channel Authentication}) and is not
4655 supported by these older versions;
4658 produce a list of channel specifications in JSON format;
4660 produce a list of channel specifications in Recutils format.
4663 @item --list-formats
4664 Display available formats for @option{--format} option.
4666 @item --profile=@var{profile}
4667 @itemx -p @var{profile}
4668 Display information about @var{profile}.
4671 @node Invoking guix archive
4672 @section Invoking @command{guix archive}
4674 @cindex @command{guix archive}
4676 The @command{guix archive} command allows users to @dfn{export} files
4677 from the store into a single archive, and to later @dfn{import} them on
4678 a machine that runs Guix.
4679 In particular, it allows store files to be transferred from one machine
4680 to the store on another machine.
4683 If you're looking for a way to produce archives in a format suitable for
4684 tools other than Guix, @pxref{Invoking guix pack}.
4687 @cindex exporting store items
4688 To export store files as an archive to standard output, run:
4691 guix archive --export @var{options} @var{specifications}...
4694 @var{specifications} may be either store file names or package
4695 specifications, as for @command{guix package} (@pxref{Invoking guix
4696 package}). For instance, the following command creates an archive
4697 containing the @code{gui} output of the @code{git} package and the main
4698 output of @code{emacs}:
4701 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4704 If the specified packages are not built yet, @command{guix archive}
4705 automatically builds them. The build process may be controlled with the
4706 common build options (@pxref{Common Build Options}).
4708 To transfer the @code{emacs} package to a machine connected over SSH,
4712 guix archive --export -r emacs | ssh the-machine guix archive --import
4716 Similarly, a complete user profile may be transferred from one machine
4717 to another like this:
4720 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4721 ssh the-machine guix archive --import
4725 However, note that, in both examples, all of @code{emacs} and the
4726 profile as well as all of their dependencies are transferred (due to
4727 @option{-r}), regardless of what is already available in the store on
4728 the target machine. The @option{--missing} option can help figure out
4729 which items are missing from the target store. The @command{guix copy}
4730 command simplifies and optimizes this whole process, so this is probably
4731 what you should use in this case (@pxref{Invoking guix copy}).
4733 @cindex nar, archive format
4734 @cindex normalized archive (nar)
4735 @cindex nar bundle, archive format
4736 Each store item is written in the @dfn{normalized archive} or @dfn{nar}
4737 format (described below), and the output of @command{guix archive
4738 --export} (and input of @command{guix archive --import}) is a @dfn{nar
4742 comparable in spirit to `tar', but with differences
4743 that make it more appropriate for our purposes. First, rather than
4744 recording all Unix metadata for each file, the nar format only mentions
4745 the file type (regular, directory, or symbolic link); Unix permissions
4746 and owner/group are dismissed. Second, the order in which directory
4747 entries are stored always follows the order of file names according to
4748 the C locale collation order. This makes archive production fully
4751 That nar bundle format is essentially the concatenation of zero or more
4752 nars along with metadata for each store item it contains: its file name,
4753 references, corresponding derivation, and a digital signature.
4755 When exporting, the daemon digitally signs the contents of the archive,
4756 and that digital signature is appended. When importing, the daemon
4757 verifies the signature and rejects the import in case of an invalid
4758 signature or if the signing key is not authorized.
4759 @c FIXME: Add xref to daemon doc about signatures.
4761 The main options are:
4765 Export the specified store files or packages (see below). Write the
4766 resulting archive to the standard output.
4768 Dependencies are @emph{not} included in the output, unless
4769 @option{--recursive} is passed.
4773 When combined with @option{--export}, this instructs @command{guix archive}
4774 to include dependencies of the given items in the archive. Thus, the
4775 resulting archive is self-contained: it contains the closure of the
4776 exported store items.
4779 Read an archive from the standard input, and import the files listed
4780 therein into the store. Abort if the archive has an invalid digital
4781 signature, or if it is signed by a public key not among the authorized
4782 keys (see @option{--authorize} below).
4785 Read a list of store file names from the standard input, one per line,
4786 and write on the standard output the subset of these files missing from
4789 @item --generate-key[=@var{parameters}]
4790 @cindex signing, archives
4791 Generate a new key pair for the daemon. This is a prerequisite before
4792 archives can be exported with @option{--export}. This
4793 operation is usually instantaneous but it can take time if the system's
4794 entropy pool needs to be refilled. On Guix System,
4795 @code{guix-service-type} takes care of generating this key pair the
4798 The generated key pair is typically stored under @file{/etc/guix}, in
4799 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4800 key, which must be kept secret). When @var{parameters} is omitted,
4801 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4802 versions before 1.6.0, it is a 4096-bit RSA key.
4803 Alternatively, @var{parameters} can specify
4804 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4805 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4806 Libgcrypt Reference Manual}).
4809 @cindex authorizing, archives
4810 Authorize imports signed by the public key passed on standard input.
4811 The public key must be in ``s-expression advanced format''---i.e., the
4812 same format as the @file{signing-key.pub} file.
4814 The list of authorized keys is kept in the human-editable file
4815 @file{/etc/guix/acl}. The file contains
4816 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4817 s-expressions''} and is structured as an access-control list in the
4818 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4821 @item --extract=@var{directory}
4822 @itemx -x @var{directory}
4823 Read a single-item archive as served by substitute servers
4824 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4825 low-level operation needed in only very narrow use cases; see below.
4827 For example, the following command extracts the substitute for Emacs
4828 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4832 https://@value{SUBSTITUTE-SERVER}/nar/gzip/@dots{}-emacs-24.5 \
4833 | gunzip | guix archive -x /tmp/emacs
4836 Single-item archives are different from multiple-item archives produced
4837 by @command{guix archive --export}; they contain a single store item,
4838 and they do @emph{not} embed a signature. Thus this operation does
4839 @emph{no} signature verification and its output should be considered
4842 The primary purpose of this operation is to facilitate inspection of
4843 archive contents coming from possibly untrusted substitute servers
4844 (@pxref{Invoking guix challenge}).
4848 Read a single-item archive as served by substitute servers
4849 (@pxref{Substitutes}) and print the list of files it contains, as in
4854 https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-emacs-26.3 \
4855 | lzip -d | guix archive -t
4860 @c *********************************************************************
4865 @cindex @file{channels.scm}, configuration file
4866 @cindex configuration file for channels
4867 @cindex @command{guix pull}, configuration file
4868 @cindex configuration of @command{guix pull}
4869 Guix and its package collection are updated by running @command{guix pull}
4870 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
4871 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
4872 customized by defining @dfn{channels} in the
4873 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
4874 of a Git repository to be deployed, and @command{guix pull} can be instructed
4875 to pull from one or more channels. In other words, channels can be used
4876 to @emph{customize} and to @emph{extend} Guix, as we will see below.
4877 Guix is able to take into account security concerns and deal with authenticated
4881 * Specifying Additional Channels:: Extending the package collection.
4882 * Using a Custom Guix Channel:: Using a customized Guix.
4883 * Replicating Guix:: Running the @emph{exact same} Guix.
4884 * Channel Authentication:: How Guix verifies what it fetches.
4885 * Creating a Channel:: How to write your custom channel.
4886 * Package Modules in a Sub-directory:: Specifying the channel's package modules location.
4887 * Declaring Channel Dependencies:: How to depend on other channels.
4888 * Specifying Channel Authorizations:: Defining channel authors authorizations.
4889 * Primary URL:: Distinguishing mirror to original.
4890 * Writing Channel News:: Communicating information to channel's users.
4893 @node Specifying Additional Channels
4894 @section Specifying Additional Channels
4896 @cindex extending the package collection (channels)
4897 @cindex variant packages (channels)
4898 You can specify @emph{additional channels} to pull from. To use a channel, write
4899 @code{~/.config/guix/channels.scm} to instruct @command{guix pull} to pull from it
4900 @emph{in addition} to the default Guix channel(s):
4902 @vindex %default-channels
4904 ;; Add variant packages to those Guix provides.
4906 (name 'variant-packages)
4907 (url "https://example.org/variant-packages.git"))
4912 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
4913 add a channel the list of channels that the variable @code{%default-channels}
4914 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
4915 Manual}). With this file in place, @command{guix pull} builds not only Guix
4916 but also the package modules from your own repository. The result in
4917 @file{~/.config/guix/current} is the union of Guix with your own package
4921 $ guix pull --list-generations
4923 Generation 19 Aug 27 2018 16:20:48
4925 repository URL: https://git.savannah.gnu.org/git/guix.git
4927 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
4928 variant-packages dd3df5e
4929 repository URL: https://example.org/variant-packages.git
4931 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
4932 11 new packages: variant-gimp, variant-emacs-with-cool-features, @dots{}
4933 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
4937 The output of @command{guix pull} above shows that Generation@tie{}19 includes
4938 both Guix and packages from the @code{variant-personal-packages} channel. Among
4939 the new and upgraded packages that are listed, some like @code{variant-gimp} and
4940 @code{variant-emacs-with-cool-features} might come from
4941 @code{variant-packages}, while others come from the Guix default channel.
4943 @node Using a Custom Guix Channel
4944 @section Using a Custom Guix Channel
4946 The channel called @code{guix} specifies where Guix itself---its command-line
4947 tools as well as its package collection---should be downloaded. For instance,
4948 suppose you want to update from another copy of the Guix repository at
4949 @code{example.org}, and specifically the @code{super-hacks} branch, you can
4950 write in @code{~/.config/guix/channels.scm} this specification:
4953 ;; Tell 'guix pull' to use another repo.
4956 (url "https://example.org/another-guix.git")
4957 (branch "super-hacks")))
4961 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
4962 branch of the repository at @code{example.org}. The authentication concern is
4963 addressed below ((@pxref{Channel Authentication}).
4965 @node Replicating Guix
4966 @section Replicating Guix
4968 @cindex pinning, channels
4969 @cindex replicating Guix
4970 @cindex reproducibility, of Guix
4971 The @command{guix pull --list-generations} output above shows precisely which
4972 commits were used to build this instance of Guix. We can thus replicate it,
4973 say, on another machine, by providing a channel specification in
4974 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
4977 ;; Deploy specific commits of my channels of interest.
4980 (url "https://git.savannah.gnu.org/git/guix.git")
4981 (commit "6298c3ffd9654d3231a6f25390b056483e8f407c"))
4983 (name 'variant-packages)
4984 (url "https://example.org/variant-packages.git")
4985 (commit "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
4988 The @command{guix describe --format=channels} command can even generate this
4989 list of channels directly (@pxref{Invoking guix describe}). The resulting
4990 file can be used with the -C options of @command{guix pull}
4991 (@pxref{Invoking guix pull}) or @command{guix time-machine}
4992 (@pxref{Invoking guix time-machine}).
4994 At this point the two machines run the @emph{exact same Guix}, with access to
4995 the @emph{exact same packages}. The output of @command{guix build gimp} on
4996 one machine will be exactly the same, bit for bit, as the output of the same
4997 command on the other machine. It also means both machines have access to all
4998 the source code of Guix and, transitively, to all the source code of every
5001 This gives you super powers, allowing you to track the provenance of binary
5002 artifacts with very fine grain, and to reproduce software environments at
5003 will---some sort of ``meta reproducibility'' capabilities, if you will.
5004 @xref{Inferiors}, for another way to take advantage of these super powers.
5006 @node Channel Authentication
5007 @section Channel Authentication
5009 @anchor{channel-authentication}
5010 @cindex authentication, of channel code
5011 The @command{guix pull} and @command{guix time-machine} commands
5012 @dfn{authenticate} the code retrieved from channels: they make sure each
5013 commit that is fetched is signed by an authorized developer. The goal
5014 is to protect from unauthorized modifications to the channel that would
5015 lead users to run malicious code.
5017 As a user, you must provide a @dfn{channel introduction} in your
5018 channels file so that Guix knows how to authenticate its first commit.
5019 A channel specification, including its introduction, looks something
5024 (name 'some-channel)
5025 (url "https://example.org/some-channel.git")
5027 (make-channel-introduction
5028 "6f0d8cc0d88abb59c324b2990bfee2876016bb86"
5029 (openpgp-fingerprint
5030 "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
5033 The specification above shows the name and URL of the channel. The call
5034 to @code{make-channel-introduction} above specifies that authentication
5035 of this channel starts at commit @code{6f0d8cc@dots{}}, which is signed
5036 by the OpenPGP key with fingerprint @code{CABB A931@dots{}}.
5038 For the main channel, called @code{guix}, you automatically get that
5039 information from your Guix installation. For other channels, include
5040 the channel introduction provided by the channel authors in your
5041 @file{channels.scm} file. Make sure you retrieve the channel
5042 introduction from a trusted source since that is the root of your trust.
5044 If you're curious about the authentication mechanics, read on!
5046 @node Creating a Channel
5047 @section Creating a Channel
5049 @cindex personal packages (channels)
5050 @cindex channels, for personal packages
5051 Let's say you have a bunch of custom package variants or personal packages
5052 that you think would make little sense to contribute to the Guix project, but
5053 would like to have these packages transparently available to you at the
5054 command line. You would first write modules containing those package
5055 definitions (@pxref{Package Modules}), maintain them in a Git repository, and
5056 then you and anyone else can use it as an additional channel to get packages
5059 @c What follows stems from discussions at
5060 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
5061 @c earlier discussions on guix-devel@gnu.org.
5063 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
5064 publish your personal channel to the world, we would like to share a few words
5069 Before publishing a channel, please consider contributing your package
5070 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
5071 to free software of all sorts, and packages in Guix proper are readily
5072 available to all Guix users and benefit from the project's quality assurance
5076 When you maintain package definitions outside Guix, we, Guix developers,
5077 consider that @emph{the compatibility burden is on you}. Remember that
5078 package modules and package definitions are just Scheme code that uses various
5079 programming interfaces (APIs). We want to remain free to change these APIs to
5080 keep improving Guix, possibly in ways that break your channel. We never
5081 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
5085 Corollary: if you're using an external channel and that channel breaks, please
5086 @emph{report the issue to the channel authors}, not to the Guix project.
5089 You've been warned! Having said this, we believe external channels are a
5090 practical way to exert your freedom to augment Guix' package collection and to
5091 share your improvements, which are basic tenets of
5092 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
5093 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
5096 To create a channel, create a Git repository containing your own package
5097 modules and make it available. The repository can contain anything, but a
5098 useful channel will contain Guile modules that export packages. Once you
5099 start using a channel, Guix will behave as if the root directory of that
5100 channel's Git repository has been added to the Guile load path (@pxref{Load
5101 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
5102 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
5103 module, then the module will be available under the name @code{(my-packages
5104 my-tools)}, and you will be able to use it like any other module
5105 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
5107 As a channel author, consider bundling authentication material with your
5108 channel so that users can authenticate it. @xref{Channel
5109 Authentication}, and @ref{Specifying Channel Authorizations}, for info
5113 @node Package Modules in a Sub-directory
5114 @section Package Modules in a Sub-directory
5116 @cindex subdirectory, channels
5117 As a channel author, you may want to keep your channel modules in a
5118 sub-directory. If your modules are in the sub-directory @file{guix}, you must
5119 add a meta-data file @file{.guix-channel} that contains:
5127 @node Declaring Channel Dependencies
5128 @section Declaring Channel Dependencies
5130 @cindex dependencies, channels
5131 @cindex meta-data, channels
5132 Channel authors may decide to augment a package collection provided by other
5133 channels. They can declare their channel to be dependent on other channels in
5134 a meta-data file @file{.guix-channel}, which is to be placed in the root of
5135 the channel repository.
5137 The meta-data file should contain a simple S-expression like this:
5144 (name 'some-collection)
5145 (url "https://example.org/first-collection.git")
5147 ;; The 'introduction' bit below is optional: you would
5148 ;; provide it for dependencies that can be authenticated.
5150 (channel-introduction
5152 (commit "a8883b58dc82e167c96506cf05095f37c2c2c6cd")
5153 (signer "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
5155 (name 'some-other-collection)
5156 (url "https://example.org/second-collection.git")
5157 (branch "testing"))))
5160 In the above example this channel is declared to depend on two other channels,
5161 which will both be fetched automatically. The modules provided by the channel
5162 will be compiled in an environment where the modules of all these declared
5163 channels are available.
5165 For the sake of reliability and maintainability, you should avoid dependencies
5166 on channels that you don't control, and you should aim to keep the number of
5167 dependencies to a minimum.
5169 @node Specifying Channel Authorizations
5170 @section Specifying Channel Authorizations
5172 @cindex channel authorizations
5173 @anchor{channel-authorizations}
5174 As we saw above, Guix ensures the source code it pulls from channels
5175 comes from authorized developers. As a channel author, you need to
5176 specify the list of authorized developers in the
5177 @file{.guix-authorizations} file in the channel's Git repository. The
5178 authentication rule is simple: each commit must be signed by a key
5179 listed in the @file{.guix-authorizations} file of its parent
5180 commit(s)@footnote{Git commits form a @dfn{directed acyclic graph}
5181 (DAG). Each commit can have zero or more parents; ``regular'' commits
5182 have one parent and merge commits have two parent commits. Read
5183 @uref{https://eagain.net/articles/git-for-computer-scientists/, @i{Git
5184 for Computer Scientists}} for a great overview.} The
5185 @file{.guix-authorizations} file looks like this:
5188 ;; Example '.guix-authorizations' file.
5191 (version 0) ;current file format version
5193 (("AD17 A21E F8AE D8F1 CC02 DBD9 F8AE D8F1 765C 61E3"
5195 ("2A39 3FFF 68F4 EF7A 3D29 12AF 68F4 EF7A 22FB B2D5"
5197 ("CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"
5201 Each fingerprint is followed by optional key/value pairs, as in the
5202 example above. Currently these key/value pairs are ignored.
5204 This authentication rule creates a chicken-and-egg issue: how do we
5205 authenticate the first commit? Related to that: how do we deal with
5206 channels whose repository history contains unsigned commits and lack
5207 @file{.guix-authorizations}? And how do we fork existing channels?
5209 @cindex channel introduction
5210 Channel introductions answer these questions by describing the first
5211 commit of a channel that should be authenticated. The first time a
5212 channel is fetched with @command{guix pull} or @command{guix
5213 time-machine}, the command looks up the introductory commit and verifies
5214 that it is signed by the specified OpenPGP key. From then on, it
5215 authenticates commits according to the rule above.
5217 Additionally, your channel must provide all the OpenPGP keys that were
5218 ever mentioned in @file{.guix-authorizations}, stored as @file{.key}
5219 files, which can be either binary or ``ASCII-armored''. By default,
5220 those @file{.key} files are searched for in the branch named
5221 @code{keyring} but you can specify a different branch name in
5222 @code{.guix-channel} like so:
5227 (keyring-reference "my-keyring-branch"))
5230 To summarize, as the author of a channel, there are three things you have
5231 to do to allow users to authenticate your code:
5235 Export the OpenPGP keys of past and present committers with @command{gpg
5236 --export} and store them in @file{.key} files, by default in a branch
5237 named @code{keyring} (we recommend making it an @dfn{orphan branch}).
5240 Introduce an initial @file{.guix-authorizations} in the channel's
5241 repository. Do that in a signed commit (@pxref{Commit Access}, for
5242 information on how to sign Git commits.)
5245 Advertise the channel introduction, for instance on your channel's web
5246 page. The channel introduction, as we saw above, is the commit/key
5247 pair---i.e., the commit that introduced @file{.guix-authorizations}, and
5248 the fingerprint of the OpenPGP used to sign it.
5251 Before pushing to your public Git repository, you can run @command{guix
5252 git-authenticate} to verify that you did sign all the commits you are
5253 about to push with an authorized key:
5256 guix git authenticate @var{commit} @var{signer}
5260 where @var{commit} and @var{signer} are your channel introduction.
5261 @xref{Invoking guix git authenticate}, for details.
5263 Publishing a signed channel requires discipline: any mistake, such as an
5264 unsigned commit or a commit signed by an unauthorized key, will prevent
5265 users from pulling from your channel---well, that's the whole point of
5266 authentication! Pay attention to merges in particular: merge commits
5267 are considered authentic if and only if they are signed by a key present
5268 in the @file{.guix-authorizations} file of @emph{both} branches.
5271 @section Primary URL
5273 @cindex primary URL, channels
5274 Channel authors can indicate the primary URL of their channel's Git
5275 repository in the @file{.guix-channel} file, like so:
5280 (url "https://example.org/guix.git"))
5283 This allows @command{guix pull} to determine whether it is pulling code
5284 from a mirror of the channel; when that is the case, it warns the user
5285 that the mirror might be stale and displays the primary URL. That way,
5286 users cannot be tricked into fetching code from a stale mirror that does
5287 not receive security updates.
5289 This feature only makes sense for authenticated repositories, such as
5290 the official @code{guix} channel, for which @command{guix pull} ensures
5291 the code it fetches is authentic.
5293 @node Writing Channel News
5294 @section Writing Channel News
5296 @cindex news, for channels
5297 Channel authors may occasionally want to communicate to their users
5298 information about important changes in the channel. You'd send them all
5299 an email, but that's not convenient.
5301 Instead, channels can provide a @dfn{news file}; when the channel users
5302 run @command{guix pull}, that news file is automatically read and
5303 @command{guix pull --news} can display the announcements that correspond
5304 to the new commits that have been pulled, if any.
5306 To do that, channel authors must first declare the name of the news file
5307 in their @file{.guix-channel} file:
5312 (news-file "etc/news.txt"))
5315 The news file itself, @file{etc/news.txt} in this example, must look
5316 something like this:
5321 (entry (tag "the-bug-fix")
5322 (title (en "Fixed terrible bug")
5324 (body (en "@@emph@{Good news@}! It's fixed!")
5325 (eo "Certe ĝi pli bone funkcias nun!")))
5326 (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
5327 (title (en "Added a great package")
5328 (ca "Què vol dir guix?"))
5329 (body (en "Don't miss the @@code@{hello@} package!"))))
5332 While the news file is using the Scheme syntax, avoid naming it with a
5333 @file{.scm} extension or else it will get picked up when building the
5334 channel and yield an error since it is not a valid module.
5335 Alternatively, you can move the channel module to a subdirectory and
5336 store the news file in another directory.
5338 The file consists of a list of @dfn{news entries}. Each entry is
5339 associated with a commit or tag: it describes changes made in this
5340 commit, possibly in preceding commits as well. Users see entries only
5341 the first time they obtain the commit the entry refers to.
5343 The @code{title} field should be a one-line summary while @code{body}
5344 can be arbitrarily long, and both can contain Texinfo markup
5345 (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
5346 a list of language tag/message tuples, which allows @command{guix pull}
5347 to display news in the language that corresponds to the user's locale.
5349 If you want to translate news using a gettext-based workflow, you can
5350 extract translatable strings with @command{xgettext} (@pxref{xgettext
5351 Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
5352 you write news entries in English first, the command below creates a PO
5353 file containing the strings to translate:
5356 xgettext -o news.po -l scheme -ken etc/news.txt
5359 To sum up, yes, you could use your channel as a blog. But beware, this
5360 is @emph{not quite} what your users might expect.
5363 @c *********************************************************************
5365 @chapter Development
5367 @cindex software development
5368 If you are a software developer, Guix provides tools that you should find
5369 helpful---independently of the language you're developing in. This is what
5370 this chapter is about.
5372 The @command{guix environment} command provides a convenient way to set up
5373 @dfn{development environments} containing all the dependencies and tools
5374 necessary to work on the software package of your choice. The @command{guix
5375 pack} command allows you to create @dfn{application bundles} that can be
5376 easily distributed to users who do not run Guix.
5379 * Invoking guix environment:: Setting up development environments.
5380 * Invoking guix pack:: Creating software bundles.
5381 * The GCC toolchain:: Working with languages supported by GCC.
5382 * Invoking guix git authenticate:: Authenticating Git repositories.
5385 @node Invoking guix environment
5386 @section Invoking @command{guix environment}
5388 @cindex reproducible build environments
5389 @cindex development environments
5390 @cindex @command{guix environment}
5391 @cindex environment, package build environment
5392 The purpose of @command{guix environment} is to assist hackers in
5393 creating reproducible development environments without polluting their
5394 package profile. The @command{guix environment} tool takes one or more
5395 packages, builds all of their inputs, and creates a shell
5396 environment to use them.
5398 The general syntax is:
5401 guix environment @var{options} @var{package}@dots{}
5404 The following example spawns a new shell set up for the development of
5408 guix environment guile
5411 If the needed dependencies are not built yet, @command{guix environment}
5412 automatically builds them. The environment of the new shell is an
5413 augmented version of the environment that @command{guix environment} was
5414 run in. It contains the necessary search paths for building the given
5415 package added to the existing environment variables. To create
5416 a ``pure'' environment, in which the original environment variables have
5417 been unset, use the @option{--pure} option@footnote{Users sometimes
5418 wrongfully augment environment variables such as @env{PATH} in their
5419 @file{~/.bashrc} file. As a consequence, when @command{guix
5420 environment} launches it, Bash may read @file{~/.bashrc}, thereby
5421 introducing ``impurities'' in these environment variables. It is an
5422 error to define such environment variables in @file{.bashrc}; instead,
5423 they should be defined in @file{.bash_profile}, which is sourced only by
5424 log-in shells. @xref{Bash Startup Files,,, bash, The GNU Bash Reference
5425 Manual}, for details on Bash start-up files.}.
5427 @vindex GUIX_ENVIRONMENT
5428 @command{guix environment} defines the @env{GUIX_ENVIRONMENT}
5429 variable in the shell it spawns; its value is the file name of the
5430 profile of this environment. This allows users to, say, define a
5431 specific prompt for development environments in their @file{.bashrc}
5432 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
5435 if [ -n "$GUIX_ENVIRONMENT" ]
5437 export PS1="\u@@\h \w [dev]\$ "
5442 ...@: or to browse the profile:
5445 $ ls "$GUIX_ENVIRONMENT/bin"
5448 Additionally, more than one package may be specified, in which case the
5449 union of the inputs for the given packages are used. For example, the
5450 command below spawns a shell where all of the dependencies of both Guile
5451 and Emacs are available:
5454 guix environment guile emacs
5457 Sometimes an interactive shell session is not desired. An arbitrary
5458 command may be invoked by placing the @code{--} token to separate the
5459 command from the rest of the arguments:
5462 guix environment guile -- make -j4
5465 In other situations, it is more convenient to specify the list of
5466 packages needed in the environment. For example, the following command
5467 runs @command{python} from an environment containing Python@tie{}2.7 and
5471 guix environment --ad-hoc python2-numpy python-2.7 -- python
5474 Furthermore, one might want the dependencies of a package and also some
5475 additional packages that are not build-time or runtime dependencies, but
5476 are useful when developing nonetheless. Because of this, the
5477 @option{--ad-hoc} flag is positional. Packages appearing before
5478 @option{--ad-hoc} are interpreted as packages whose dependencies will be
5479 added to the environment. Packages appearing after are interpreted as
5480 packages that will be added to the environment directly. For example,
5481 the following command creates a Guix development environment that
5482 additionally includes Git and strace:
5485 guix environment --pure guix --ad-hoc git strace
5489 Sometimes it is desirable to isolate the environment as much as
5490 possible, for maximal purity and reproducibility. In particular, when
5491 using Guix on a host distro that is not Guix System, it is desirable to
5492 prevent access to @file{/usr/bin} and other system-wide resources from
5493 the development environment. For example, the following command spawns
5494 a Guile REPL in a ``container'' where only the store and the current
5495 working directory are mounted:
5498 guix environment --ad-hoc --container guile -- guile
5502 The @option{--container} option requires Linux-libre 3.19 or newer.
5505 @cindex certificates
5506 Another typical use case for containers is to run security-sensitive
5507 applications such as a web browser. To run Eolie, we must expose and
5508 share some files and directories; we include @code{nss-certs} and expose
5509 @file{/etc/ssl/certs/} for HTTPS authentication; finally we preserve the
5510 @env{DISPLAY} environment variable since containerized graphical
5511 applications won't display without it.
5514 guix environment --preserve='^DISPLAY$' --container --network \
5515 --expose=/etc/machine-id \
5516 --expose=/etc/ssl/certs/ \
5517 --share=$HOME/.local/share/eolie/=$HOME/.local/share/eolie/ \
5518 --ad-hoc eolie nss-certs dbus -- eolie
5521 The available options are summarized below.
5524 @item --root=@var{file}
5525 @itemx -r @var{file}
5526 @cindex persistent environment
5527 @cindex garbage collector root, for environments
5528 Make @var{file} a symlink to the profile for this environment, and
5529 register it as a garbage collector root.
5531 This is useful if you want to protect your environment from garbage
5532 collection, to make it ``persistent''.
5534 When this option is omitted, the environment is protected from garbage
5535 collection only for the duration of the @command{guix environment}
5536 session. This means that next time you recreate the same environment,
5537 you could have to rebuild or re-download packages. @xref{Invoking guix
5538 gc}, for more on GC roots.
5540 @item --expression=@var{expr}
5541 @itemx -e @var{expr}
5542 Create an environment for the package or list of packages that
5543 @var{expr} evaluates to.
5545 For example, running:
5548 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
5551 starts a shell with the environment for this specific variant of the
5557 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
5560 starts a shell with all the base system packages available.
5562 The above commands only use the default output of the given packages.
5563 To select other outputs, two element tuples can be specified:
5566 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
5569 @item --load=@var{file}
5570 @itemx -l @var{file}
5571 Create an environment for the package or list of packages that the code
5572 within @var{file} evaluates to.
5574 As an example, @var{file} might contain a definition like this
5575 (@pxref{Defining Packages}):
5578 @verbatiminclude environment-gdb.scm
5581 @item --manifest=@var{file}
5582 @itemx -m @var{file}
5583 Create an environment for the packages contained in the manifest object
5584 returned by the Scheme code in @var{file}. This option can be repeated
5585 several times, in which case the manifests are concatenated.
5587 This is similar to the same-named option in @command{guix package}
5588 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
5592 Include all specified packages in the resulting environment, as if an
5593 @i{ad hoc} package were defined with them as inputs. This option is
5594 useful for quickly creating an environment without having to write a
5595 package expression to contain the desired inputs.
5597 For instance, the command:
5600 guix environment --ad-hoc guile guile-sdl -- guile
5603 runs @command{guile} in an environment where Guile and Guile-SDL are
5606 Note that this example implicitly asks for the default output of
5607 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
5608 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
5609 of @code{glib} (@pxref{Packages with Multiple Outputs}).
5611 This option may be composed with the default behavior of @command{guix
5612 environment}. Packages appearing before @option{--ad-hoc} are
5613 interpreted as packages whose dependencies will be added to the
5614 environment, the default behavior. Packages appearing after are
5615 interpreted as packages that will be added to the environment directly.
5618 Unset existing environment variables when building the new environment, except
5619 those specified with @option{--preserve} (see below). This has the effect of
5620 creating an environment in which search paths only contain package inputs.
5622 @item --preserve=@var{regexp}
5623 @itemx -E @var{regexp}
5624 When used alongside @option{--pure}, preserve the environment variables
5625 matching @var{regexp}---in other words, put them on a ``white list'' of
5626 environment variables that must be preserved. This option can be repeated
5630 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
5634 This example runs @command{mpirun} in a context where the only environment
5635 variables defined are @env{PATH}, environment variables whose name starts
5636 with @samp{SLURM}, as well as the usual ``precious'' variables (@env{HOME},
5639 @item --search-paths
5640 Display the environment variable definitions that make up the
5643 @item --system=@var{system}
5644 @itemx -s @var{system}
5645 Attempt to build for @var{system}---e.g., @code{i686-linux}.
5650 Run @var{command} within an isolated container. The current working
5651 directory outside the container is mapped inside the container.
5652 Additionally, unless overridden with @option{--user}, a dummy home
5653 directory is created that matches the current user's home directory, and
5654 @file{/etc/passwd} is configured accordingly.
5656 The spawned process runs as the current user outside the container. Inside
5657 the container, it has the same UID and GID as the current user, unless
5658 @option{--user} is passed (see below).
5662 For containers, share the network namespace with the host system.
5663 Containers created without this flag only have access to the loopback
5666 @item --link-profile
5668 For containers, link the environment profile to @file{~/.guix-profile}
5669 within the container and set @code{GUIX_ENVIRONMENT} to that.
5670 This is equivalent to making @file{~/.guix-profile} a symlink to the
5671 actual profile within the container.
5672 Linking will fail and abort the environment if the directory already
5673 exists, which will certainly be the case if @command{guix environment}
5674 was invoked in the user's home directory.
5676 Certain packages are configured to look in @file{~/.guix-profile} for
5677 configuration files and data;@footnote{For example, the
5678 @code{fontconfig} package inspects @file{~/.guix-profile/share/fonts}
5679 for additional fonts.} @option{--link-profile} allows these programs to
5680 behave as expected within the environment.
5682 @item --user=@var{user}
5683 @itemx -u @var{user}
5684 For containers, use the username @var{user} in place of the current
5685 user. The generated @file{/etc/passwd} entry within the container will
5686 contain the name @var{user}, the home directory will be
5687 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
5688 the UID and GID inside the container are 1000. @var{user}
5689 need not exist on the system.
5691 Additionally, any shared or exposed path (see @option{--share} and
5692 @option{--expose} respectively) whose target is within the current user's
5693 home directory will be remapped relative to @file{/home/USER}; this
5694 includes the automatic mapping of the current working directory.
5697 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
5699 guix environment --container --user=foo \
5700 --expose=$HOME/test \
5701 --expose=/tmp/target=$HOME/target
5704 While this will limit the leaking of user identity through home paths
5705 and each of the user fields, this is only one useful component of a
5706 broader privacy/anonymity solution---not one in and of itself.
5709 For containers, the default behavior is to share the current working
5710 directory with the isolated container and immediately change to that
5711 directory within the container. If this is undesirable,
5712 @option{--no-cwd} will cause the current working directory to @emph{not}
5713 be automatically shared and will change to the user's home directory
5714 within the container instead. See also @option{--user}.
5716 @item --expose=@var{source}[=@var{target}]
5717 @itemx --share=@var{source}[=@var{target}]
5718 For containers, @option{--expose} (resp. @option{--share}) exposes the
5719 file system @var{source} from the host system as the read-only
5720 (resp. writable) file system @var{target} within the container. If
5721 @var{target} is not specified, @var{source} is used as the target mount
5722 point in the container.
5724 The example below spawns a Guile REPL in a container in which the user's
5725 home directory is accessible read-only via the @file{/exchange}
5729 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
5734 @command{guix environment}
5735 also supports all of the common build options that @command{guix
5736 build} supports (@pxref{Common Build Options}) as well as package
5737 transformation options (@pxref{Package Transformation Options}).
5739 @node Invoking guix pack
5740 @section Invoking @command{guix pack}
5742 Occasionally you want to pass software to people who are not (yet!)
5743 lucky enough to be using Guix. You'd tell them to run @command{guix
5744 package -i @var{something}}, but that's not possible in this case. This
5745 is where @command{guix pack} comes in.
5748 If you are looking for ways to exchange binaries among machines that
5749 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
5750 publish}, and @ref{Invoking guix archive}.
5755 @cindex application bundle
5756 @cindex software bundle
5757 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
5758 @dfn{software bundle}: it creates a tarball or some other archive
5759 containing the binaries of the software you're interested in, and all
5760 its dependencies. The resulting archive can be used on any machine that
5761 does not have Guix, and people can run the exact same binaries as those
5762 you have with Guix. The pack itself is created in a bit-reproducible
5763 fashion, so anyone can verify that it really contains the build results
5764 that you pretend to be shipping.
5766 For example, to create a bundle containing Guile, Emacs, Geiser, and all
5767 their dependencies, you can run:
5770 $ guix pack guile emacs geiser
5772 /gnu/store/@dots{}-pack.tar.gz
5775 The result here is a tarball containing a @file{/gnu/store} directory
5776 with all the relevant packages. The resulting tarball contains a
5777 @dfn{profile} with the three packages of interest; the profile is the
5778 same as would be created by @command{guix package -i}. It is this
5779 mechanism that is used to create Guix's own standalone binary tarball
5780 (@pxref{Binary Installation}).
5782 Users of this pack would have to run
5783 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
5784 find inconvenient. To work around it, you can create, say, a
5785 @file{/opt/gnu/bin} symlink to the profile:
5788 guix pack -S /opt/gnu/bin=bin guile emacs geiser
5792 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
5794 @cindex relocatable binaries, with @command{guix pack}
5795 What if the recipient of your pack does not have root privileges on
5796 their machine, and thus cannot unpack it in the root file system? In
5797 that case, you will want to use the @option{--relocatable} option (see
5798 below). This option produces @dfn{relocatable binaries}, meaning they
5799 they can be placed anywhere in the file system hierarchy: in the example
5800 above, users can unpack your tarball in their home directory and
5801 directly run @file{./opt/gnu/bin/guile}.
5803 @cindex Docker, build an image with guix pack
5804 Alternatively, you can produce a pack in the Docker image format using
5805 the following command:
5808 guix pack -f docker -S /bin=bin guile guile-readline
5812 The result is a tarball that can be passed to the @command{docker load}
5813 command, followed by @code{docker run}:
5816 docker load < @var{file}
5817 docker run -ti guile-guile-readline /bin/guile
5821 where @var{file} is the image returned by @var{guix pack}, and
5822 @code{guile-guile-readline} is its ``image tag''. See the
5823 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5824 documentation} for more information.
5826 @cindex Singularity, build an image with guix pack
5827 @cindex SquashFS, build an image with guix pack
5828 Yet another option is to produce a SquashFS image with the following
5832 guix pack -f squashfs bash guile emacs geiser
5836 The result is a SquashFS file system image that can either be mounted or
5837 directly be used as a file system container image with the
5838 @uref{https://www.sylabs.io/docs/, Singularity container execution
5839 environment}, using commands like @command{singularity shell} or
5840 @command{singularity exec}.
5842 Several command-line options allow you to customize your pack:
5845 @item --format=@var{format}
5846 @itemx -f @var{format}
5847 Produce a pack in the given @var{format}.
5849 The available formats are:
5853 This is the default format. It produces a tarball containing all the
5854 specified binaries and symlinks.
5857 This produces a tarball that follows the
5858 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
5859 Docker Image Specification}. The ``repository name'' as it appears in
5860 the output of the @command{docker images} command is computed from
5861 package names passed on the command line or in the manifest file.
5864 This produces a SquashFS image containing all the specified binaries and
5865 symlinks, as well as empty mount points for virtual file systems like
5869 Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
5870 For that reason, @command{guix pack -f squashfs} always implies @code{-S
5871 /bin=bin}. Thus, your @command{guix pack} invocation must always start
5872 with something like:
5875 guix pack -f squashfs bash @dots{}
5878 If you forget the @code{bash} (or similar) package, @command{singularity
5879 run} and @command{singularity exec} will fail with an unhelpful ``no
5880 such file or directory'' message.
5884 @cindex relocatable binaries
5887 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
5888 anywhere in the file system hierarchy and run from there.
5890 When this option is passed once, the resulting binaries require support for
5891 @dfn{user namespaces} in the kernel Linux; when passed
5892 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
5893 PRoot support, can be thought of as the abbreviation of ``Really
5894 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to
5895 other techniques if user namespaces are unavailable, and essentially
5896 work anywhere---see below for the implications.
5898 For example, if you create a pack containing Bash with:
5901 guix pack -RR -S /mybin=bin bash
5905 ...@: you can copy that pack to a machine that lacks Guix, and from your
5906 home directory as a normal user, run:
5914 In that shell, if you type @code{ls /gnu/store}, you'll notice that
5915 @file{/gnu/store} shows up and contains all the dependencies of
5916 @code{bash}, even though the machine actually lacks @file{/gnu/store}
5917 altogether! That is probably the simplest way to deploy Guix-built
5918 software on a non-Guix machine.
5921 By default, relocatable binaries rely on the @dfn{user namespace} feature of
5922 the kernel Linux, which allows unprivileged users to mount or change root.
5923 Old versions of Linux did not support it, and some GNU/Linux distributions
5926 To produce relocatable binaries that work even in the absence of user
5927 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
5928 case, binaries will try user namespace support and fall back to another
5929 @dfn{execution engine} if user namespaces are not supported. The
5930 following execution engines are supported:
5934 Try user namespaces and fall back to PRoot if user namespaces are not
5935 supported (see below).
5938 Try user namespaces and fall back to Fakechroot if user namespaces are
5939 not supported (see below).
5942 Run the program through user namespaces and abort if they are not
5946 Run through PRoot. The @uref{https://proot-me.github.io/, PRoot} program
5947 provides the necessary
5948 support for file system virtualization. It achieves that by using the
5949 @code{ptrace} system call on the running program. This approach has the
5950 advantage to work without requiring special kernel support, but it incurs
5951 run-time overhead every time a system call is made.
5954 Run through Fakechroot. @uref{https://github.com/dex4er/fakechroot/,
5955 Fakechroot} virtualizes file system accesses by intercepting calls to C
5956 library functions such as @code{open}, @code{stat}, @code{exec}, and so
5957 on. Unlike PRoot, it incurs very little overhead. However, it does not
5958 always work: for example, some file system accesses made from within the
5959 C library are not intercepted, and file system accesses made @i{via}
5960 direct syscalls are not intercepted either, leading to erratic behavior.
5963 @vindex GUIX_EXECUTION_ENGINE
5964 When running a wrapped program, you can explicitly request one of the
5965 execution engines listed above by setting the
5966 @env{GUIX_EXECUTION_ENGINE} environment variable accordingly.
5969 @cindex entry point, for Docker images
5970 @item --entry-point=@var{command}
5971 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
5972 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
5973 support it. @var{command} must be relative to the profile contained in the
5976 The entry point specifies the command that tools like @code{docker run} or
5977 @code{singularity run} automatically start by default. For example, you can
5981 guix pack -f docker --entry-point=bin/guile guile
5984 The resulting pack can easily be loaded and @code{docker run} with no extra
5985 arguments will spawn @code{bin/guile}:
5988 docker load -i pack.tar.gz
5989 docker run @var{image-id}
5992 @item --expression=@var{expr}
5993 @itemx -e @var{expr}
5994 Consider the package @var{expr} evaluates to.
5996 This has the same purpose as the same-named option in @command{guix
5997 build} (@pxref{Additional Build Options, @option{--expression} in
5998 @command{guix build}}).
6000 @item --manifest=@var{file}
6001 @itemx -m @var{file}
6002 Use the packages contained in the manifest object returned by the Scheme
6003 code in @var{file}. This option can be repeated several times, in which
6004 case the manifests are concatenated.
6006 This has a similar purpose as the same-named option in @command{guix
6007 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
6008 same manifest files. It allows you to define a collection of packages
6009 once and use it both for creating profiles and for creating archives
6010 for use on machines that do not have Guix installed. Note that you can
6011 specify @emph{either} a manifest file @emph{or} a list of packages,
6014 @item --system=@var{system}
6015 @itemx -s @var{system}
6016 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
6017 the system type of the build host.
6019 @item --target=@var{triplet}
6020 @cindex cross-compilation
6021 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
6022 as @code{"aarch64-linux-gnu"} (@pxref{Specifying target triplets, GNU
6023 configuration triplets,, autoconf, Autoconf}).
6025 @item --compression=@var{tool}
6026 @itemx -C @var{tool}
6027 Compress the resulting tarball using @var{tool}---one of @code{gzip},
6028 @code{zstd}, @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no
6031 @item --symlink=@var{spec}
6032 @itemx -S @var{spec}
6033 Add the symlinks specified by @var{spec} to the pack. This option can
6034 appear several times.
6036 @var{spec} has the form @code{@var{source}=@var{target}}, where
6037 @var{source} is the symlink that will be created and @var{target} is the
6040 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
6041 symlink pointing to the @file{bin} sub-directory of the profile.
6043 @item --save-provenance
6044 Save provenance information for the packages passed on the command line.
6045 Provenance information includes the URL and commit of the channels in use
6048 Provenance information is saved in the
6049 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
6050 usual package metadata---the name and version of each package, their
6051 propagated inputs, and so on. It is useful information to the recipient of
6052 the pack, who then knows how the pack was (supposedly) obtained.
6054 This option is not enabled by default because, like timestamps, provenance
6055 information contributes nothing to the build process. In other words, there
6056 is an infinity of channel URLs and commit IDs that can lead to the same pack.
6057 Recording such ``silent'' metadata in the output thus potentially breaks the
6058 source-to-binary bitwise reproducibility property.
6060 @item --root=@var{file}
6061 @itemx -r @var{file}
6062 @cindex garbage collector root, for packs
6063 Make @var{file} a symlink to the resulting pack, and register it as a garbage
6066 @item --localstatedir
6067 @itemx --profile-name=@var{name}
6068 Include the ``local state directory'', @file{/var/guix}, in the resulting
6069 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
6070 profile---by default @var{name} is @code{guix-profile}, which corresponds to
6071 @file{~root/.guix-profile}.
6073 @file{/var/guix} contains the store database (@pxref{The Store}) as well
6074 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
6075 the pack means that the store is ``complete'' and manageable by Guix;
6076 not providing it pack means that the store is ``dead'': items cannot be
6077 added to it or removed from it after extraction of the pack.
6079 One use case for this is the Guix self-contained binary tarball
6080 (@pxref{Binary Installation}).
6084 Print the name of the derivation that builds the pack.
6087 Use the bootstrap binaries to build the pack. This option is only
6088 useful to Guix developers.
6091 In addition, @command{guix pack} supports all the common build options
6092 (@pxref{Common Build Options}) and all the package transformation
6093 options (@pxref{Package Transformation Options}).
6096 @node The GCC toolchain
6097 @section The GCC toolchain
6101 @cindex linker wrapper
6102 @cindex toolchain, for C development
6103 @cindex toolchain, for Fortran development
6105 If you need a complete toolchain for compiling and linking C or C++
6106 source code, use the @code{gcc-toolchain} package. This package
6107 provides a complete GCC toolchain for C/C++ development, including GCC
6108 itself, the GNU C Library (headers and binaries, plus debugging symbols
6109 in the @code{debug} output), Binutils, and a linker wrapper.
6111 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
6112 passed to the linker, add corresponding @code{-rpath} arguments, and
6113 invoke the actual linker with this new set of arguments. You can instruct the
6114 wrapper to refuse to link against libraries not in the store by setting the
6115 @env{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
6117 The package @code{gfortran-toolchain} provides a complete GCC toolchain
6118 for Fortran development. For other languages, please use
6119 @samp{guix search gcc toolchain} (@pxref{guix-search,, Invoking guix package}).
6122 @node Invoking guix git authenticate
6123 @section Invoking @command{guix git authenticate}
6125 The @command{guix git authenticate} command authenticates a Git checkout
6126 following the same rule as for channels (@pxref{channel-authentication,
6127 channel authentication}). That is, starting from a given commit, it
6128 ensures that all subsequent commits are signed by an OpenPGP key whose
6129 fingerprint appears in the @file{.guix-authorizations} file of its
6132 You will find this command useful if you maintain a channel. But in
6133 fact, this authentication mechanism is useful in a broader context, so
6134 you might want to use it for Git repositories that have nothing to do
6137 The general syntax is:
6140 guix git authenticate @var{commit} @var{signer} [@var{options}@dots{}]
6143 By default, this command authenticates the Git checkout in the current
6144 directory; it outputs nothing and exits with exit code zero on success
6145 and non-zero on failure. @var{commit} above denotes the first commit
6146 where authentication takes place, and @var{signer} is the OpenPGP
6147 fingerprint of public key used to sign @var{commit}. Together, they
6148 form a ``channel introduction'' (@pxref{channel-authentication, channel
6149 introduction}). The options below allow you to fine-tune the process.
6152 @item --repository=@var{directory}
6153 @itemx -r @var{directory}
6154 Open the Git repository in @var{directory} instead of the current
6157 @item --keyring=@var{reference}
6158 @itemx -k @var{reference}
6159 Load OpenPGP keyring from @var{reference}, the reference of a branch
6160 such as @code{origin/keyring} or @code{my-keyring}. The branch must
6161 contain OpenPGP public keys in @file{.key} files, either in binary form
6162 or ``ASCII-armored''. By default the keyring is loaded from the branch
6163 named @code{keyring}.
6166 Display commit signing statistics upon completion.
6168 @item --cache-key=@var{key}
6169 Previously-authenticated commits are cached in a file under
6170 @file{~/.cache/guix/authentication}. This option forces the cache to be
6171 stored in file @var{key} in that directory.
6173 @item --historical-authorizations=@var{file}
6174 By default, any commit whose parent commit(s) lack the
6175 @file{.guix-authorizations} file is considered inauthentic. In
6176 contrast, this option considers the authorizations in @var{file} for any
6177 commit that lacks @file{.guix-authorizations}. The format of @var{file}
6178 is the same as that of @file{.guix-authorizations}
6179 (@pxref{channel-authorizations, @file{.guix-authorizations} format}).
6183 @c *********************************************************************
6184 @node Programming Interface
6185 @chapter Programming Interface
6187 GNU Guix provides several Scheme programming interfaces (APIs) to
6188 define, build, and query packages. The first interface allows users to
6189 write high-level package definitions. These definitions refer to
6190 familiar packaging concepts, such as the name and version of a package,
6191 its build system, and its dependencies. These definitions can then be
6192 turned into concrete build actions.
6194 Build actions are performed by the Guix daemon, on behalf of users. In a
6195 standard setup, the daemon has write access to the store---the
6196 @file{/gnu/store} directory---whereas users do not. The recommended
6197 setup also has the daemon perform builds in chroots, under specific
6198 build users, to minimize interference with the rest of the system.
6201 Lower-level APIs are available to interact with the daemon and the
6202 store. To instruct the daemon to perform a build action, users actually
6203 provide it with a @dfn{derivation}. A derivation is a low-level
6204 representation of the build actions to be taken, and the environment in
6205 which they should occur---derivations are to package definitions what
6206 assembly is to C programs. The term ``derivation'' comes from the fact
6207 that build results @emph{derive} from them.
6209 This chapter describes all these APIs in turn, starting from high-level
6210 package definitions.
6213 * Package Modules:: Packages from the programmer's viewpoint.
6214 * Defining Packages:: Defining new packages.
6215 * Defining Package Variants:: Customizing packages.
6216 * Build Systems:: Specifying how packages are built.
6217 * Build Phases:: Phases of the build process of a package.
6218 * Build Utilities:: Helpers for your package definitions and more.
6219 * The Store:: Manipulating the package store.
6220 * Derivations:: Low-level interface to package derivations.
6221 * The Store Monad:: Purely functional interface to the store.
6222 * G-Expressions:: Manipulating build expressions.
6223 * Invoking guix repl:: Programming Guix in Guile
6226 @node Package Modules
6227 @section Package Modules
6229 From a programming viewpoint, the package definitions of the
6230 GNU distribution are provided by Guile modules in the @code{(gnu packages
6231 @dots{})} name space@footnote{Note that packages under the @code{(gnu
6232 packages @dots{})} module name space are not necessarily ``GNU
6233 packages''. This module naming scheme follows the usual Guile module
6234 naming convention: @code{gnu} means that these modules are distributed
6235 as part of the GNU system, and @code{packages} identifies modules that
6236 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
6237 Reference Manual}). For instance, the @code{(gnu packages emacs)}
6238 module exports a variable named @code{emacs}, which is bound to a
6239 @code{<package>} object (@pxref{Defining Packages}).
6241 The @code{(gnu packages @dots{})} module name space is
6242 automatically scanned for packages by the command-line tools. For
6243 instance, when running @code{guix install emacs}, all the @code{(gnu
6244 packages @dots{})} modules are scanned until one that exports a package
6245 object whose name is @code{emacs} is found. This package search
6246 facility is implemented in the @code{(gnu packages)} module.
6248 @cindex customization, of packages
6249 @cindex package module search path
6250 Users can store package definitions in modules with different
6251 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
6252 name and module name must match. For instance, the @code{(my-packages
6253 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
6254 relative to the load path specified with @option{--load-path} or
6255 @env{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
6256 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
6257 these package definitions visible to the user interfaces:
6261 By adding the directory containing your package modules to the search path
6262 with the @code{-L} flag of @command{guix package} and other commands
6263 (@pxref{Common Build Options}), or by setting the @env{GUIX_PACKAGE_PATH}
6264 environment variable described below.
6267 By defining a @dfn{channel} and configuring @command{guix pull} so that it
6268 pulls from it. A channel is essentially a Git repository containing package
6269 modules. @xref{Channels}, for more information on how to define and use
6273 @env{GUIX_PACKAGE_PATH} works similarly to other search path variables:
6275 @defvr {Environment Variable} GUIX_PACKAGE_PATH
6276 This is a colon-separated list of directories to search for additional
6277 package modules. Directories listed in this variable take precedence
6278 over the own modules of the distribution.
6281 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
6282 each package is built based solely on other packages in the
6283 distribution. The root of this dependency graph is a small set of
6284 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
6285 bootstrap)} module. For more information on bootstrapping,
6286 @pxref{Bootstrapping}.
6288 @node Defining Packages
6289 @section Defining Packages
6291 The high-level interface to package definitions is implemented in the
6292 @code{(guix packages)} and @code{(guix build-system)} modules. As an
6293 example, the package definition, or @dfn{recipe}, for the GNU Hello
6294 package looks like this:
6297 (define-module (gnu packages hello)
6298 #:use-module (guix packages)
6299 #:use-module (guix download)
6300 #:use-module (guix build-system gnu)
6301 #:use-module (guix licenses)
6302 #:use-module (gnu packages gawk))
6304 (define-public hello
6310 (uri (string-append "mirror://gnu/hello/hello-" version
6314 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
6315 (build-system gnu-build-system)
6316 (arguments '(#:configure-flags '("--enable-silent-rules")))
6317 (inputs `(("gawk" ,gawk)))
6318 (synopsis "Hello, GNU world: An example GNU package")
6319 (description "Guess what GNU Hello prints!")
6320 (home-page "https://www.gnu.org/software/hello/")
6325 Without being a Scheme expert, the reader may have guessed the meaning
6326 of the various fields here. This expression binds the variable
6327 @code{hello} to a @code{<package>} object, which is essentially a record
6328 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
6329 This package object can be inspected using procedures found in the
6330 @code{(guix packages)} module; for instance, @code{(package-name hello)}
6331 returns---surprise!---@code{"hello"}.
6333 With luck, you may be able to import part or all of the definition of
6334 the package you are interested in from another repository, using the
6335 @code{guix import} command (@pxref{Invoking guix import}).
6337 In the example above, @code{hello} is defined in a module of its own,
6338 @code{(gnu packages hello)}. Technically, this is not strictly
6339 necessary, but it is convenient to do so: all the packages defined in
6340 modules under @code{(gnu packages @dots{})} are automatically known to
6341 the command-line tools (@pxref{Package Modules}).
6343 There are a few points worth noting in the above package definition:
6347 The @code{source} field of the package is an @code{<origin>} object
6348 (@pxref{origin Reference}, for the complete reference).
6349 Here, the @code{url-fetch} method from @code{(guix download)} is used,
6350 meaning that the source is a file to be downloaded over FTP or HTTP.
6352 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
6353 the GNU mirrors defined in @code{(guix download)}.
6355 The @code{sha256} field specifies the expected SHA256 hash of the file
6356 being downloaded. It is mandatory, and allows Guix to check the
6357 integrity of the file. The @code{(base32 @dots{})} form introduces the
6358 base32 representation of the hash. You can obtain this information with
6359 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
6360 hash} (@pxref{Invoking guix hash}).
6363 When needed, the @code{origin} form can also have a @code{patches} field
6364 listing patches to be applied, and a @code{snippet} field giving a
6365 Scheme expression to modify the source code.
6368 @cindex GNU Build System
6369 The @code{build-system} field specifies the procedure to build the
6370 package (@pxref{Build Systems}). Here, @code{gnu-build-system}
6371 represents the familiar GNU Build System, where packages may be
6372 configured, built, and installed with the usual @code{./configure &&
6373 make && make check && make install} command sequence.
6375 When you start packaging non-trivial software, you may need tools to
6376 manipulate those build phases, manipulate files, and so on. @xref{Build
6377 Utilities}, for more on this.
6380 The @code{arguments} field specifies options for the build system
6381 (@pxref{Build Systems}). Here it is interpreted by
6382 @code{gnu-build-system} as a request run @file{configure} with the
6383 @option{--enable-silent-rules} flag.
6389 What about these quote (@code{'}) characters? They are Scheme syntax to
6390 introduce a literal list; @code{'} is synonymous with @code{quote}.
6391 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
6392 for details. Here the value of the @code{arguments} field is a list of
6393 arguments passed to the build system down the road, as with @code{apply}
6394 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
6397 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
6398 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
6399 @code{#:configure-flags} is a keyword used to pass a keyword argument
6400 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
6404 The @code{inputs} field specifies inputs to the build process---i.e.,
6405 build-time or run-time dependencies of the package. Here, we define an
6406 input called @code{"gawk"} whose value is that of the @code{gawk}
6407 variable; @code{gawk} is itself bound to a @code{<package>} object.
6409 @cindex backquote (quasiquote)
6412 @cindex comma (unquote)
6416 @findex unquote-splicing
6417 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
6418 us to introduce a literal list in the @code{inputs} field, while
6419 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
6420 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
6423 Note that GCC, Coreutils, Bash, and other essential tools do not need to
6424 be specified as inputs here. Instead, @code{gnu-build-system} takes care
6425 of ensuring that they are present (@pxref{Build Systems}).
6427 However, any other dependencies need to be specified in the
6428 @code{inputs} field. Any dependency not specified here will simply be
6429 unavailable to the build process, possibly leading to a build failure.
6432 @xref{package Reference}, for a full description of possible fields.
6434 Once a package definition is in place, the
6435 package may actually be built using the @code{guix build} command-line
6436 tool (@pxref{Invoking guix build}), troubleshooting any build failures
6437 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
6438 package definition using the @command{guix edit} command
6439 (@pxref{Invoking guix edit}).
6440 @xref{Packaging Guidelines}, for
6441 more information on how to test package definitions, and
6442 @ref{Invoking guix lint}, for information on how to check a definition
6443 for style conformance.
6444 @vindex GUIX_PACKAGE_PATH
6445 Lastly, @pxref{Channels}, for information
6446 on how to extend the distribution by adding your own package definitions
6449 Finally, updating the package definition to a new upstream version
6450 can be partly automated by the @command{guix refresh} command
6451 (@pxref{Invoking guix refresh}).
6453 Behind the scenes, a derivation corresponding to the @code{<package>}
6454 object is first computed by the @code{package-derivation} procedure.
6455 That derivation is stored in a @file{.drv} file under @file{/gnu/store}.
6456 The build actions it prescribes may then be realized by using the
6457 @code{build-derivations} procedure (@pxref{The Store}).
6459 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
6460 Return the @code{<derivation>} object of @var{package} for @var{system}
6461 (@pxref{Derivations}).
6463 @var{package} must be a valid @code{<package>} object, and @var{system}
6464 must be a string denoting the target system type---e.g.,
6465 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
6466 must be a connection to the daemon, which operates on the store
6467 (@pxref{The Store}).
6471 @cindex cross-compilation
6472 Similarly, it is possible to compute a derivation that cross-builds a
6473 package for some other system:
6475 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
6476 @var{package} @var{target} [@var{system}]
6477 Return the @code{<derivation>} object of @var{package} cross-built from
6478 @var{system} to @var{target}.
6480 @var{target} must be a valid GNU triplet denoting the target hardware
6481 and operating system, such as @code{"aarch64-linux-gnu"}
6482 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
6485 Once you have package definitions, you can easily define @emph{variants}
6486 of those packages. @xref{Defining Package Variants}, for more on that.
6489 * package Reference:: The package data type.
6490 * origin Reference:: The origin data type.
6494 @node package Reference
6495 @subsection @code{package} Reference
6497 This section summarizes all the options available in @code{package}
6498 declarations (@pxref{Defining Packages}).
6500 @deftp {Data Type} package
6501 This is the data type representing a package recipe.
6505 The name of the package, as a string.
6507 @item @code{version}
6508 The version of the package, as a string.
6511 An object telling how the source code for the package should be
6512 acquired. Most of the time, this is an @code{origin} object, which
6513 denotes a file fetched from the Internet (@pxref{origin Reference}). It
6514 can also be any other ``file-like'' object such as a @code{local-file},
6515 which denotes a file from the local file system (@pxref{G-Expressions,
6516 @code{local-file}}).
6518 @item @code{build-system}
6519 The build system that should be used to build the package (@pxref{Build
6522 @item @code{arguments} (default: @code{'()})
6523 The arguments that should be passed to the build system. This is a
6524 list, typically containing sequential keyword-value pairs.
6526 @item @code{inputs} (default: @code{'()})
6527 @itemx @code{native-inputs} (default: @code{'()})
6528 @itemx @code{propagated-inputs} (default: @code{'()})
6529 @cindex inputs, of packages
6530 These fields list dependencies of the package. Each one is a list of
6531 tuples, where each tuple has a label for the input (a string) as its
6532 first element, a package, origin, or derivation as its second element,
6533 and optionally the name of the output thereof that should be used, which
6534 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
6535 more on package outputs). For example, the list below specifies three
6539 `(("libffi" ,libffi)
6540 ("libunistring" ,libunistring)
6541 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
6544 @cindex cross compilation, package dependencies
6545 The distinction between @code{native-inputs} and @code{inputs} is
6546 necessary when considering cross-compilation. When cross-compiling,
6547 dependencies listed in @code{inputs} are built for the @emph{target}
6548 architecture; conversely, dependencies listed in @code{native-inputs}
6549 are built for the architecture of the @emph{build} machine.
6551 @code{native-inputs} is typically used to list tools needed at
6552 build time, but not at run time, such as Autoconf, Automake, pkg-config,
6553 Gettext, or Bison. @command{guix lint} can report likely mistakes in
6554 this area (@pxref{Invoking guix lint}).
6556 @anchor{package-propagated-inputs}
6557 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
6558 specified packages will be automatically installed to profiles
6559 (@pxref{Features, the role of profiles in Guix}) alongside the package
6560 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
6561 package}}, for information on how @command{guix package} deals with
6564 For example this is necessary when packaging a C/C++ library that needs
6565 headers of another library to compile, or when a pkg-config file refers
6566 to another one @i{via} its @code{Requires} field.
6568 Another example where @code{propagated-inputs} is useful is for languages
6569 that lack a facility to record the run-time search path akin to the
6570 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
6571 more. When packaging libraries written in those languages, ensure they
6572 can find library code they depend on at run time by listing run-time
6573 dependencies in @code{propagated-inputs} rather than @code{inputs}.
6575 @item @code{outputs} (default: @code{'("out")})
6576 The list of output names of the package. @xref{Packages with Multiple
6577 Outputs}, for typical uses of additional outputs.
6579 @item @code{native-search-paths} (default: @code{'()})
6580 @itemx @code{search-paths} (default: @code{'()})
6581 A list of @code{search-path-specification} objects describing
6582 search-path environment variables honored by the package.
6584 @item @code{replacement} (default: @code{#f})
6585 This must be either @code{#f} or a package object that will be used as a
6586 @dfn{replacement} for this package. @xref{Security Updates, grafts},
6589 @item @code{synopsis}
6590 A one-line description of the package.
6592 @item @code{description}
6593 A more elaborate description of the package.
6595 @item @code{license}
6596 @cindex license, of packages
6597 The license of the package; a value from @code{(guix licenses)},
6598 or a list of such values.
6600 @item @code{home-page}
6601 The URL to the home-page of the package, as a string.
6603 @item @code{supported-systems} (default: @code{%supported-systems})
6604 The list of systems supported by the package, as strings of the form
6605 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
6607 @item @code{location} (default: source location of the @code{package} form)
6608 The source location of the package. It is useful to override this when
6609 inheriting from another package, in which case this field is not
6610 automatically corrected.
6614 @deffn {Scheme Syntax} this-package
6615 When used in the @emph{lexical scope} of a package field definition, this
6616 identifier resolves to the package being defined.
6618 The example below shows how to add a package as a native input of itself when
6626 ;; When cross-compiled, Guile, for example, depends on
6627 ;; a native version of itself. Add it here.
6628 (native-inputs (if (%current-target-system)
6629 `(("self" ,this-package))
6633 It is an error to refer to @code{this-package} outside a package definition.
6636 Because packages are regular Scheme objects that capture a complete
6637 dependency graph and associated build procedures, it is often useful to
6638 write procedures that take a package and return a modified version
6639 thereof according to some parameters. Below are a few examples.
6641 @cindex tool chain, choosing a package's tool chain
6642 @deffn {Scheme Procedure} package-with-c-toolchain @var{package} @var{toolchain}
6643 Return a variant of @var{package} that uses @var{toolchain} instead of
6644 the default GNU C/C++ toolchain. @var{toolchain} must be a list of
6645 inputs (label/package tuples) providing equivalent functionality, such
6646 as the @code{gcc-toolchain} package.
6648 The example below returns a variant of the @code{hello} package built
6649 with GCC@tie{}10.x and the rest of the GNU tool chain (Binutils and the
6650 GNU C Library) instead of the default tool chain:
6653 (let ((toolchain (specification->package "gcc-toolchain@@10")))
6654 (package-with-c-toolchain hello `(("toolchain" ,toolchain))))
6657 The build tool chain is part of the @dfn{implicit inputs} of
6658 packages---it's usually not listed as part of the various ``inputs''
6659 fields and is instead pulled in by the build system. Consequently, this
6660 procedure works by changing the build system of @var{package} so that it
6661 pulls in @var{toolchain} instead of the defaults. @ref{Build Systems},
6662 for more on build systems.
6665 @node origin Reference
6666 @subsection @code{origin} Reference
6668 This section documents @dfn{origins}. An @code{origin} declaration
6669 specifies data that must be ``produced''---downloaded, usually---and
6670 whose content hash is known in advance. Origins are primarily used to
6671 represent the source code of packages (@pxref{Defining Packages}). For
6672 that reason, the @code{origin} form allows you to declare patches to
6673 apply to the original source code as well as code snippets to modify it.
6675 @deftp {Data Type} origin
6676 This is the data type representing a source code origin.
6680 An object containing the URI of the source. The object type depends on
6681 the @code{method} (see below). For example, when using the
6682 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
6683 values are: a URL represented as a string, or a list thereof.
6685 @cindex fixed-output derivations, for download
6687 A monadic procedure that handles the given URI. The procedure must
6688 accept at least three arguments: the value of the @code{uri} field and
6689 the hash algorithm and hash value specified by the @code{hash} field.
6690 It must return a store item or a derivation in the store monad
6691 (@pxref{The Store Monad}); most methods return a fixed-output derivation
6692 (@pxref{Derivations}).
6694 Commonly used methods include @code{url-fetch}, which fetches data from
6695 a URL, and @code{git-fetch}, which fetches data from a Git repository
6699 A bytevector containing the SHA-256 hash of the source. This is
6700 equivalent to providing a @code{content-hash} SHA256 object in the
6701 @code{hash} field described below.
6704 The @code{content-hash} object of the source---see below for how to use
6705 @code{content-hash}.
6707 You can obtain this information using @code{guix download}
6708 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
6711 @item @code{file-name} (default: @code{#f})
6712 The file name under which the source code should be saved. When this is
6713 @code{#f}, a sensible default value will be used in most cases. In case
6714 the source is fetched from a URL, the file name from the URL will be
6715 used. For version control checkouts, it is recommended to provide the
6716 file name explicitly because the default is not very descriptive.
6718 @item @code{patches} (default: @code{'()})
6719 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
6720 file-like objects}) pointing to patches to be applied to the source.
6722 This list of patches must be unconditional. In particular, it cannot
6723 depend on the value of @code{%current-system} or
6724 @code{%current-target-system}.
6726 @item @code{snippet} (default: @code{#f})
6727 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
6728 in the source directory. This is a convenient way to modify the source,
6729 sometimes more convenient than a patch.
6731 @item @code{patch-flags} (default: @code{'("-p1")})
6732 A list of command-line flags that should be passed to the @code{patch}
6735 @item @code{patch-inputs} (default: @code{#f})
6736 Input packages or derivations to the patching process. When this is
6737 @code{#f}, the usual set of inputs necessary for patching are provided,
6738 such as GNU@tie{}Patch.
6740 @item @code{modules} (default: @code{'()})
6741 A list of Guile modules that should be loaded during the patching
6742 process and while running the code in the @code{snippet} field.
6744 @item @code{patch-guile} (default: @code{#f})
6745 The Guile package that should be used in the patching process. When
6746 this is @code{#f}, a sensible default is used.
6750 @deftp {Data Type} content-hash @var{value} [@var{algorithm}]
6751 Construct a content hash object for the given @var{algorithm}, and with
6752 @var{value} as its hash value. When @var{algorithm} is omitted, assume
6753 it is @code{sha256}.
6755 @var{value} can be a literal string, in which case it is base32-decoded,
6756 or it can be a bytevector.
6758 The following forms are all equivalent:
6761 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj")
6762 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"
6764 (content-hash (base32
6765 "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"))
6766 (content-hash (base64 "kkb+RPaP7uyMZmu4eXPVkM4BN8yhRd8BTHLslb6f/Rc=")
6770 Technically, @code{content-hash} is currently implemented as a macro.
6771 It performs sanity checks at macro-expansion time, when possible, such
6772 as ensuring that @var{value} has the right size for @var{algorithm}.
6775 As we have seen above, how exactly the data an origin refers to is
6776 retrieved is determined by its @code{method} field. The @code{(guix
6777 download)} module provides the most common method, @code{url-fetch},
6780 @deffn {Scheme Procedure} url-fetch @var{url} @var{hash-algo} @var{hash} @
6781 [name] [#:executable? #f]
6782 Return a fixed-output derivation that fetches data from @var{url} (a
6783 string, or a list of strings denoting alternate URLs), which is expected
6784 to have hash @var{hash} of type @var{hash-algo} (a symbol). By default,
6785 the file name is the base name of URL; optionally, @var{name} can
6786 specify a different file name. When @var{executable?} is true, make the
6787 downloaded file executable.
6789 When one of the URL starts with @code{mirror://}, then its host part is
6790 interpreted as the name of a mirror scheme, taken from @file{%mirror-file}.
6792 Alternatively, when URL starts with @code{file://}, return the
6793 corresponding file name in the store.
6796 Likewise, the @code{(guix git-download)} module defines the
6797 @code{git-fetch} origin method, which fetches data from a Git version
6798 control repository, and the @code{git-reference} data type to describe
6799 the repository and revision to fetch.
6801 @deffn {Scheme Procedure} git-fetch @var{ref} @var{hash-algo} @var{hash}
6802 Return a fixed-output derivation that fetches @var{ref}, a
6803 @code{<git-reference>} object. The output is expected to have recursive
6804 hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
6805 the file name, or a generic name if @code{#f}.
6808 @deftp {Data Type} git-reference
6809 This data type represents a Git reference for @code{git-fetch} to
6814 The URL of the Git repository to clone.
6817 This string denotes either the commit to fetch (a hexadecimal string,
6818 either the full SHA1 commit or a ``short'' commit string; the latter is
6819 not recommended) or the tag to fetch.
6821 @item @code{recursive?} (default: @code{#f})
6822 This Boolean indicates whether to recursively fetch Git sub-modules.
6825 The example below denotes the @code{v2.10} tag of the GNU@tie{}Hello
6830 (url "https://git.savannah.gnu.org/git/hello.git")
6834 This is equivalent to the reference below, which explicitly names the
6839 (url "https://git.savannah.gnu.org/git/hello.git")
6840 (commit "dc7dc56a00e48fe6f231a58f6537139fe2908fb9"))
6844 For Mercurial repositories, the module @code{(guix hg-download)} defines
6845 the @code{hg-fetch} origin method and @code{hg-reference} data type for
6846 support of the Mercurial version control system.
6848 @deffn {Scheme Procedure} hg-fetch @var{ref} @var{hash-algo} @var{hash} @
6850 Return a fixed-output derivation that fetches @var{ref}, a
6851 @code{<hg-reference>} object. The output is expected to have recursive
6852 hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
6853 the file name, or a generic name if @code{#false}.
6856 @node Defining Package Variants
6857 @section Defining Package Variants
6859 @cindex customizing packages
6860 @cindex variants, of packages
6861 One of the nice things with Guix is that, given a package definition,
6862 you can easily @emph{derive} variants of that package---for a different
6863 upstream version, with different dependencies, different compilation
6864 options, and so on. Some of these custom packages can be defined
6865 straight from the command line (@pxref{Package Transformation Options}).
6866 This section describes how to define package variants in code. This can
6867 be useful in ``manifests'' (@pxref{profile-manifest,
6868 @option{--manifest}}) and in your own package collection
6869 (@pxref{Creating a Channel}), among others!
6871 @cindex inherit, for package definitions
6872 As discussed earlier, packages are first-class objects in the Scheme
6873 language. The @code{(guix packages)} module provides the @code{package}
6874 construct to define new package objects (@pxref{package Reference}).
6875 The easiest way to define a package variant is using the @code{inherit}
6876 keyword together with @code{package}. This allows you to inherit from a
6877 package definition while overriding the fields you want.
6879 For example, given the @code{hello} variable, which contains a
6880 definition for the current version of GNU@tie{}Hello, here's how you
6881 would define a variant for version 2.2 (released in 2006, it's
6885 (use-modules (gnu packages base)) ;for 'hello'
6893 (uri (string-append "mirror://gnu/hello/hello-" version
6897 "0lappv4slgb5spyqbh6yl5r013zv72yqg2pcl30mginf3wdqd8k9"))))))
6900 The example above corresponds to what the @option{--with-source} package
6901 transformation option does. Essentially @code{hello-2.2} preserves all
6902 the fields of @code{hello}, except @code{version} and @code{source},
6903 which it overrides. Note that the original @code{hello} variable is
6904 still there, in the @code{(gnu packages base)} module, unchanged. When
6905 you define a custom package like this, you are really @emph{adding} a
6906 new package definition; the original one remains available.
6908 You can just as well define variants with a different set of
6909 dependencies than the original package. For example, the default
6910 @code{gdb} package depends on @code{guile}, but since that is an
6911 optional dependency, you can define a variant that removes that
6915 (use-modules (gnu packages gdb) ;for 'gdb'
6916 (srfi srfi-1)) ;for 'alist-delete'
6918 (define gdb-sans-guile
6921 (inputs (alist-delete "guile"
6922 (package-inputs gdb)))))
6925 The @code{alist-delete} call above removes the tuple from the
6926 @code{inputs} field that has @code{"guile"} as its first element
6927 (@pxref{SRFI-1 Association Lists,,, guile, GNU Guile Reference
6930 In some cases, you may find it useful to write functions
6931 (``procedures'', in Scheme parlance) that return a package based on some
6932 parameters. For example, consider the @code{luasocket} library for the
6933 Lua programming language. We want to create @code{luasocket} packages
6934 for major versions of Lua. One way to do that is to define a procedure
6935 that takes a Lua package and returns a @code{luasocket} package that
6939 (define (make-lua-socket name lua)
6940 ;; Return a luasocket package built with LUA.
6944 ;; several fields omitted
6947 (synopsis "Socket library for Lua")))
6949 (define-public lua5.1-socket
6950 (make-lua-socket "lua5.1-socket" lua-5.1))
6952 (define-public lua5.2-socket
6953 (make-lua-socket "lua5.2-socket" lua-5.2))
6956 Here we have defined packages @code{lua5.1-socket} and
6957 @code{lua5.2-socket} by calling @code{make-lua-socket} with different
6958 arguments. @xref{Procedures,,, guile, GNU Guile Reference Manual}, for
6959 more info on procedures. Having top-level public definitions for these
6960 two packages means that they can be referred to from the command line
6961 (@pxref{Package Modules}).
6963 @cindex package transformations
6964 These are pretty simple package variants. As a convenience, the
6965 @code{(guix transformations)} module provides a high-level interface
6966 that directly maps to the more sophisticated package transformation
6967 options (@pxref{Package Transformation Options}):
6969 @deffn {Scheme Procedure} options->transformation @var{opts}
6970 Return a procedure that, when passed an object to build (package,
6971 derivation, etc.), applies the transformations specified by @var{opts} and returns
6972 the resulting objects. @var{opts} must be a list of symbol/string pairs such as:
6975 ((with-branch . "guile-gcrypt=master")
6976 (without-tests . "libgcrypt"))
6979 Each symbol names a transformation and the corresponding string is an argument
6980 to that transformation.
6983 For instance, a manifest equivalent to this command:
6987 --with-branch=guile-gcrypt=master \
6988 --with-debug-info=zlib
6992 ... would look like this:
6995 (use-modules (guix transformations))
6998 ;; The package transformation procedure.
6999 (options->transformation
7000 '((with-branch . "guile-gcrypt=master")
7001 (with-debug-info . "zlib"))))
7004 (list (transform (specification->package "guix"))))
7007 @cindex input rewriting
7008 @cindex dependency graph rewriting
7009 The @code{options->transformation} procedure is convenient, but it's
7010 perhaps also not as flexible as you may like. How is it implemented?
7011 The astute reader probably noticed that most package transformation
7012 options go beyond the superficial changes shown in the first examples of
7013 this section: they involve @dfn{input rewriting}, whereby the dependency
7014 graph of a package is rewritten by replacing specific inputs by others.
7016 Dependency graph rewriting, for the purposes of swapping packages in the
7017 graph, is what the @code{package-input-rewriting} procedure in
7018 @code{(guix packages)} implements.
7020 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
7021 [@var{rewrite-name}] [#:deep? #t]
7022 Return a procedure that, when passed a package, replaces its direct and
7023 indirect dependencies, including implicit inputs when @var{deep?} is
7024 true, according to @var{replacements}. @var{replacements} is a list of
7025 package pairs; the first element of each pair is the package to replace,
7026 and the second one is the replacement.
7028 Optionally, @var{rewrite-name} is a one-argument procedure that takes
7029 the name of a package and returns its new name after rewrite.
7033 Consider this example:
7036 (define libressl-instead-of-openssl
7037 ;; This is a procedure to replace OPENSSL by LIBRESSL,
7039 (package-input-rewriting `((,openssl . ,libressl))))
7041 (define git-with-libressl
7042 (libressl-instead-of-openssl git))
7046 Here we first define a rewriting procedure that replaces @var{openssl}
7047 with @var{libressl}. Then we use it to define a @dfn{variant} of the
7048 @var{git} package that uses @var{libressl} instead of @var{openssl}.
7049 This is exactly what the @option{--with-input} command-line option does
7050 (@pxref{Package Transformation Options, @option{--with-input}}).
7052 The following variant of @code{package-input-rewriting} can match packages to
7053 be replaced by name rather than by identity.
7055 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements} [#:deep? #t]
7056 Return a procedure that, given a package, applies the given
7057 @var{replacements} to all the package graph, including implicit inputs
7058 unless @var{deep?} is false. @var{replacements} is a list of
7059 spec/procedures pair; each spec is a package specification such as
7060 @code{"gcc"} or @code{"guile@@2"}, and each procedure takes a matching
7061 package and returns a replacement for that package.
7064 The example above could be rewritten this way:
7067 (define libressl-instead-of-openssl
7068 ;; Replace all the packages called "openssl" with LibreSSL.
7069 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
7072 The key difference here is that, this time, packages are matched by spec and
7073 not by identity. In other words, any package in the graph that is called
7074 @code{openssl} will be replaced.
7076 A more generic procedure to rewrite a package dependency graph is
7077 @code{package-mapping}: it supports arbitrary changes to nodes in the
7080 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}] [#:deep? #f]
7081 Return a procedure that, given a package, applies @var{proc} to all the packages
7082 depended on and returns the resulting package. The procedure stops recursion
7083 when @var{cut?} returns true for a given package. When @var{deep?} is true, @var{proc} is
7084 applied to implicit inputs as well.
7089 @section Build Systems
7091 @cindex build system
7092 Each package definition specifies a @dfn{build system} and arguments for
7093 that build system (@pxref{Defining Packages}). This @code{build-system}
7094 field represents the build procedure of the package, as well as implicit
7095 dependencies of that build procedure.
7097 Build systems are @code{<build-system>} objects. The interface to
7098 create and manipulate them is provided by the @code{(guix build-system)}
7099 module, and actual build systems are exported by specific modules.
7101 @cindex bag (low-level package representation)
7102 Under the hood, build systems first compile package objects to
7103 @dfn{bags}. A @dfn{bag} is like a package, but with less
7104 ornamentation---in other words, a bag is a lower-level representation of
7105 a package, which includes all the inputs of that package, including some
7106 that were implicitly added by the build system. This intermediate
7107 representation is then compiled to a derivation (@pxref{Derivations}).
7108 The @code{package-with-c-toolchain} is an example of a way to change the
7109 implicit inputs that a package's build system pulls in (@pxref{package
7110 Reference, @code{package-with-c-toolchain}}).
7112 Build systems accept an optional list of @dfn{arguments}. In package
7113 definitions, these are passed @i{via} the @code{arguments} field
7114 (@pxref{Defining Packages}). They are typically keyword arguments
7115 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
7116 Guile Reference Manual}). The value of these arguments is usually
7117 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
7118 by the daemon (@pxref{Derivations}).
7120 The main build system is @code{gnu-build-system}, which implements the
7121 standard build procedure for GNU and many other packages. It
7122 is provided by the @code{(guix build-system gnu)} module.
7124 @defvr {Scheme Variable} gnu-build-system
7125 @code{gnu-build-system} represents the GNU Build System, and variants
7126 thereof (@pxref{Configuration, configuration and makefile conventions,,
7127 standards, GNU Coding Standards}).
7129 @cindex build phases
7130 In a nutshell, packages using it are configured, built, and installed with
7131 the usual @code{./configure && make && make check && make install}
7132 command sequence. In practice, a few additional steps are often needed.
7133 All these steps are split up in separate @dfn{phases},
7134 notably@footnote{Please see the @code{(guix build gnu-build-system)}
7135 modules for more details about the build phases.}:
7139 Unpack the source tarball, and change the current directory to the
7140 extracted source tree. If the source is actually a directory, copy it
7141 to the build tree, and enter that directory.
7143 @item patch-source-shebangs
7144 Patch shebangs encountered in source files so they refer to the right
7145 store file names. For instance, this changes @code{#!/bin/sh} to
7146 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
7149 Run the @file{configure} script with a number of default options, such
7150 as @option{--prefix=/gnu/store/@dots{}}, as well as the options specified
7151 by the @code{#:configure-flags} argument.
7154 Run @code{make} with the list of flags specified with
7155 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
7156 (the default), build with @code{make -j}.
7159 Run @code{make check}, or some other target specified with
7160 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
7161 @code{#:parallel-tests?} argument is true (the default), run @code{make
7165 Run @code{make install} with the flags listed in @code{#:make-flags}.
7167 @item patch-shebangs
7168 Patch shebangs on the installed executable files.
7171 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
7172 is false), copying them to the @code{debug} output when available
7173 (@pxref{Installing Debugging Files}).
7176 @vindex %standard-phases
7177 The build-side module @code{(guix build gnu-build-system)} defines
7178 @code{%standard-phases} as the default list of build phases.
7179 @code{%standard-phases} is a list of symbol/procedure pairs, where the
7180 procedure implements the actual phase.
7182 @xref{Build Phases}, for more info on build phases and ways to customize
7185 In addition, this build system ensures that the ``standard'' environment
7186 for GNU packages is available. This includes tools such as GCC, libc,
7187 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
7188 build-system gnu)} module for a complete list). We call these the
7189 @dfn{implicit inputs} of a package, because package definitions do not
7190 have to mention them.
7193 Other @code{<build-system>} objects are defined to support other
7194 conventions and tools used by free software packages. They inherit most
7195 of @code{gnu-build-system}, and differ mainly in the set of inputs
7196 implicitly added to the build process, and in the list of phases
7197 executed. Some of these build systems are listed below.
7199 @defvr {Scheme Variable} ant-build-system
7200 This variable is exported by @code{(guix build-system ant)}. It
7201 implements the build procedure for Java packages that can be built with
7202 @url{https://ant.apache.org/, Ant build tool}.
7204 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
7205 provided by the @code{icedtea} package to the set of inputs. Different
7206 packages can be specified with the @code{#:ant} and @code{#:jdk}
7207 parameters, respectively.
7209 When the original package does not provide a suitable Ant build file,
7210 the parameter @code{#:jar-name} can be used to generate a minimal Ant
7211 build file @file{build.xml} with tasks to build the specified jar
7212 archive. In this case the parameter @code{#:source-dir} can be used to
7213 specify the source sub-directory, defaulting to ``src''.
7215 The @code{#:main-class} parameter can be used with the minimal ant
7216 buildfile to specify the main class of the resulting jar. This makes the
7217 jar file executable. The @code{#:test-include} parameter can be used to
7218 specify the list of junit tests to run. It defaults to
7219 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
7220 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
7221 because abstract classes cannot be run as tests.
7223 The parameter @code{#:build-target} can be used to specify the Ant task
7224 that should be run during the @code{build} phase. By default the
7225 ``jar'' task will be run.
7229 @defvr {Scheme Variable} android-ndk-build-system
7230 @cindex Android distribution
7231 @cindex Android NDK build system
7232 This variable is exported by @code{(guix build-system android-ndk)}. It
7233 implements a build procedure for Android NDK (native development kit)
7234 packages using a Guix-specific build process.
7236 The build system assumes that packages install their public interface
7237 (header) files to the subdirectory @file{include} of the @code{out} output and
7238 their libraries to the subdirectory @file{lib} the @code{out} output.
7240 It's also assumed that the union of all the dependencies of a package
7241 has no conflicting files.
7243 For the time being, cross-compilation is not supported - so right now
7244 the libraries and header files are assumed to be host tools.
7248 @defvr {Scheme Variable} asdf-build-system/source
7249 @defvrx {Scheme Variable} asdf-build-system/sbcl
7250 @defvrx {Scheme Variable} asdf-build-system/ecl
7252 These variables, exported by @code{(guix build-system asdf)}, implement
7253 build procedures for Common Lisp packages using
7254 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
7255 definition facility for Common Lisp programs and libraries.
7257 The @code{asdf-build-system/source} system installs the packages in
7258 source form, and can be loaded using any common lisp implementation, via
7259 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
7260 systems in the format which a particular implementation understands.
7261 These build systems can also be used to produce executable programs, or
7262 lisp images which contain a set of packages pre-loaded.
7264 The build system uses naming conventions. For binary packages, the
7265 package name should be prefixed with the lisp implementation, such as
7266 @code{sbcl-} for @code{asdf-build-system/sbcl}.
7268 Additionally, the corresponding source package should be labeled using
7269 the same convention as python packages (see @ref{Python Modules}), using
7270 the @code{cl-} prefix.
7272 In order to create executable programs and images, the build-side
7273 procedures @code{build-program} and @code{build-image} can be used.
7274 They should be called in a build phase after the
7275 @code{create-asdf-configuration} phase, so that the system which was
7276 just built can be used within the resulting image. @code{build-program}
7277 requires a list of Common Lisp expressions to be passed as the
7278 @code{#:entry-program} argument.
7280 By default, all the @file{.asd} files present in the sources are read to
7281 find system definitions. The @code{#:asd-files} parameter can be used
7282 to specify the list of @file{.asd} files to read. Furthermore, if the
7283 package defines a system for its tests in a separate file, it will be
7284 loaded before the tests are run if it is specified by the
7285 @code{#:test-asd-file} parameter. If it is not set, the files
7286 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
7287 and @code{test.asd} will be tried if they exist.
7289 If for some reason the package must be named in a different way than the
7290 naming conventions suggest, or if several systems must be compiled, the
7291 @code{#:asd-systems} parameter can be used to specify the list of system
7296 @defvr {Scheme Variable} cargo-build-system
7297 @cindex Rust programming language
7298 @cindex Cargo (Rust build system)
7299 This variable is exported by @code{(guix build-system cargo)}. It
7300 supports builds of packages using Cargo, the build tool of the
7301 @uref{https://www.rust-lang.org, Rust programming language}.
7303 It adds @code{rustc} and @code{cargo} to the set of inputs.
7304 A different Rust package can be specified with the @code{#:rust} parameter.
7306 Regular cargo dependencies should be added to the package definition via the
7307 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
7308 spec can be a package or a source definition. Note that the spec must
7309 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
7310 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
7311 should be added to the package definition via the
7312 @code{#:cargo-development-inputs} parameter.
7314 In its @code{configure} phase, this build system will make any source inputs
7315 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
7316 parameters available to cargo. It will also remove an included
7317 @code{Cargo.lock} file to be recreated by @code{cargo} during the
7318 @code{build} phase. The @code{install} phase installs the binaries
7319 defined by the crate.
7323 @defvr {Scheme Variable} copy-build-system
7324 This variable is exported by @code{(guix build-system copy)}. It
7325 supports builds of simple packages that don't require much compiling,
7326 mostly just moving files around.
7328 It adds much of the @code{gnu-build-system} packages to the set of
7329 inputs. Because of this, the @code{copy-build-system} does not require
7330 all the boilerplate code often needed for the
7331 @code{trivial-build-system}.
7333 To further simplify the file installation process, an
7334 @code{#:install-plan} argument is exposed to let the packager specify
7335 which files go where. The install plan is a list of @code{(@var{source}
7336 @var{target} [@var{filters}])}. @var{filters} are optional.
7339 @item When @var{source} matches a file or directory without trailing slash, install it to @var{target}.
7341 @item If @var{target} has a trailing slash, install @var{source} basename beneath @var{target}.
7342 @item Otherwise install @var{source} as @var{target}.
7345 @item When @var{source} is a directory with a trailing slash, or when @var{filters} are used,
7346 the trailing slash of @var{target} is implied with the same meaning
7349 @item Without @var{filters}, install the full @var{source} @emph{content} to @var{target}.
7350 @item With @var{filters} among @code{#:include}, @code{#:include-regexp}, @code{#:exclude},
7351 @code{#:exclude-regexp}, only select files are installed depending on
7352 the filters. Each filters is specified by a list of strings.
7354 @item With @code{#:include}, install all the files which the path suffix matches
7355 at least one of the elements in the given list.
7356 @item With @code{#:include-regexp}, install all the files which the
7357 subpaths match at least one of the regular expressions in the given
7359 @item The @code{#:exclude} and @code{#:exclude-regexp} filters
7360 are the complement of their inclusion counterpart. Without @code{#:include} flags,
7361 install all files but those matching the exclusion filters.
7362 If both inclusions and exclusions are specified, the exclusions are done
7363 on top of the inclusions.
7366 In all cases, the paths relative to @var{source} are preserved within
7373 @item @code{("foo/bar" "share/my-app/")}: Install @file{bar} to @file{share/my-app/bar}.
7374 @item @code{("foo/bar" "share/my-app/baz")}: Install @file{bar} to @file{share/my-app/baz}.
7375 @item @code{("foo/" "share/my-app")}: Install the content of @file{foo} inside @file{share/my-app},
7376 e.g., install @file{foo/sub/file} to @file{share/my-app/sub/file}.
7377 @item @code{("foo/" "share/my-app" #:include ("sub/file"))}: Install only @file{foo/sub/file} to
7378 @file{share/my-app/sub/file}.
7379 @item @code{("foo/sub" "share/my-app" #:include ("file"))}: Install @file{foo/sub/file} to
7380 @file{share/my-app/file}.
7385 @cindex Clojure (programming language)
7386 @cindex simple Clojure build system
7387 @defvr {Scheme Variable} clojure-build-system
7388 This variable is exported by @code{(guix build-system clojure)}. It implements
7389 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
7390 using plain old @code{compile} in Clojure. Cross-compilation is not supported
7393 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
7394 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
7395 @code{#:zip} parameters, respectively.
7397 A list of source directories, test directories and jar names can be specified
7398 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
7399 parameters, respectively. Compile directory and main class can be specified
7400 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
7401 Other parameters are documented below.
7403 This build system is an extension of @code{ant-build-system}, but with the
7404 following phases changed:
7409 This phase calls @code{compile} in Clojure to compile source files and runs
7410 @command{jar} to create jars from both source files and compiled files
7411 according to the include list and exclude list specified in
7412 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
7413 has priority over the include list. These lists consist of symbols
7414 representing Clojure libraries or the special keyword @code{#:all} representing
7415 all Clojure libraries found under the source directories. The parameter
7416 @code{#:omit-source?} decides if source should be included into the jars.
7419 This phase runs tests according to the include list and exclude list specified
7420 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
7421 meanings are analogous to that of @code{#:aot-include} and
7422 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
7423 stands for all Clojure libraries found under the test directories. The
7424 parameter @code{#:tests?} decides if tests should be run.
7427 This phase installs all jars built previously.
7430 Apart from the above, this build system also contains an additional phase:
7435 This phase installs all top-level files with base name matching
7436 @code{%doc-regex}. A different regex can be specified with the
7437 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
7438 directories specified in @code{#:doc-dirs} are installed as well.
7442 @defvr {Scheme Variable} cmake-build-system
7443 This variable is exported by @code{(guix build-system cmake)}. It
7444 implements the build procedure for packages using the
7445 @url{https://www.cmake.org, CMake build tool}.
7447 It automatically adds the @code{cmake} package to the set of inputs.
7448 Which package is used can be specified with the @code{#:cmake}
7451 The @code{#:configure-flags} parameter is taken as a list of flags
7452 passed to the @command{cmake} command. The @code{#:build-type}
7453 parameter specifies in abstract terms the flags passed to the compiler;
7454 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
7455 debugging information''), which roughly means that code is compiled with
7456 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
7459 @defvr {Scheme Variable} dune-build-system
7460 This variable is exported by @code{(guix build-system dune)}. It
7461 supports builds of packages using @uref{https://dune.build/, Dune}, a build
7462 tool for the OCaml programming language. It is implemented as an extension
7463 of the @code{ocaml-build-system} which is described below. As such, the
7464 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
7467 It automatically adds the @code{dune} package to the set of inputs.
7468 Which package is used can be specified with the @code{#:dune}
7471 There is no @code{configure} phase because dune packages typically don't
7472 need to be configured. The @code{#:build-flags} parameter is taken as a
7473 list of flags passed to the @code{dune} command during the build.
7475 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
7476 command instead of the more recent @code{dune} command while building
7477 a package. Its default value is @code{#f}.
7479 The @code{#:package} parameter can be passed to specify a package name, which
7480 is useful when a package contains multiple packages and you want to build
7481 only one of them. This is equivalent to passing the @code{-p} argument to
7485 @defvr {Scheme Variable} go-build-system
7486 This variable is exported by @code{(guix build-system go)}. It
7487 implements a build procedure for Go packages using the standard
7488 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
7489 Go build mechanisms}.
7491 The user is expected to provide a value for the key @code{#:import-path}
7492 and, in some cases, @code{#:unpack-path}. The
7493 @url{https://golang.org/doc/code.html#ImportPaths, import path}
7494 corresponds to the file system path expected by the package's build
7495 scripts and any referring packages, and provides a unique way to
7496 refer to a Go package. It is typically based on a combination of the
7497 package source code's remote URI and file system hierarchy structure. In
7498 some cases, you will need to unpack the package's source code to a
7499 different directory structure than the one indicated by the import path,
7500 and @code{#:unpack-path} should be used in such cases.
7502 Packages that provide Go libraries should install their source code into
7503 the built output. The key @code{#:install-source?}, which defaults to
7504 @code{#t}, controls whether or not the source code is installed. It can
7505 be set to @code{#f} for packages that only provide executable files.
7508 @defvr {Scheme Variable} glib-or-gtk-build-system
7509 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
7510 is intended for use with packages making use of GLib or GTK+.
7512 This build system adds the following two phases to the ones defined by
7513 @code{gnu-build-system}:
7516 @item glib-or-gtk-wrap
7517 The phase @code{glib-or-gtk-wrap} ensures that programs in
7518 @file{bin/} are able to find GLib ``schemas'' and
7519 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
7520 modules}. This is achieved by wrapping the programs in launch scripts
7521 that appropriately set the @env{XDG_DATA_DIRS} and @env{GTK_PATH}
7522 environment variables.
7524 It is possible to exclude specific package outputs from that wrapping
7525 process by listing their names in the
7526 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
7527 when an output is known not to contain any GLib or GTK+ binaries, and
7528 where wrapping would gratuitously add a dependency of that output on
7531 @item glib-or-gtk-compile-schemas
7532 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
7533 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
7534 GSettings schemas} of GLib are compiled. Compilation is performed by the
7535 @command{glib-compile-schemas} program. It is provided by the package
7536 @code{glib:bin} which is automatically imported by the build system.
7537 The @code{glib} package providing @command{glib-compile-schemas} can be
7538 specified with the @code{#:glib} parameter.
7541 Both phases are executed after the @code{install} phase.
7544 @defvr {Scheme Variable} guile-build-system
7545 This build system is for Guile packages that consist exclusively of Scheme
7546 code and that are so lean that they don't even have a makefile, let alone a
7547 @file{configure} script. It compiles Scheme code using @command{guild
7548 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
7549 installs the @file{.scm} and @file{.go} files in the right place. It also
7550 installs documentation.
7552 This build system supports cross-compilation by using the
7553 @option{--target} option of @samp{guild compile}.
7555 Packages built with @code{guile-build-system} must provide a Guile package in
7556 their @code{native-inputs} field.
7559 @defvr {Scheme Variable} julia-build-system
7560 This variable is exported by @code{(guix build-system julia)}. It
7561 implements the build procedure used by @uref{https://julialang.org/,
7562 julia} packages, which essentially is similar to running @samp{julia -e
7563 'using Pkg; Pkg.add(package)'} in an environment where
7564 @env{JULIA_LOAD_PATH} contains the paths to all Julia package inputs.
7565 Tests are run with @code{Pkg.test}.
7567 Julia packages require the source @code{file-name} to be the real name of the
7568 package, correctly capitalized.
7570 For packages requiring shared library dependencies, you may need to write the
7571 @file{/deps/deps.jl} file manually. It's usually a line of @code{const
7572 variable = /gnu/store/library.so} for each dependency, plus a void function
7573 @code{check_deps() = nothing}.
7575 Some older packages that aren't using @file{Package.toml} yet, will require
7576 this file to be created, too. The function @code{julia-create-package-toml}
7577 helps creating the file. You need to pass the outputs and the source of the
7578 package, it's name (the same as the @code{file-name} parameter), the package
7579 uuid, the package version, and a list of dependencies specified by their name
7583 @defvr {Scheme Variable} maven-build-system
7584 This variable is exported by @code{(guix build-system maven)}. It implements
7585 a build procedure for @uref{https://maven.apache.org, Maven} packages. Maven
7586 is a dependency and lifecycle management tool for Java. A user of Maven
7587 specifies dependencies and plugins in a @file{pom.xml} file that Maven reads.
7588 When Maven does not have one of the dependencies or plugins in its repository,
7589 it will download them and use them to build the package.
7591 The maven build system ensures that maven will not try to download any
7592 dependency by running in offline mode. Maven will fail if a dependency is
7593 missing. Before running Maven, the @file{pom.xml} (and subprojects) are
7594 modified to specify the version of dependencies and plugins that match the
7595 versions available in the guix build environment. Dependencies and plugins
7596 must be installed in the fake maven repository at @file{lib/m2}, and are
7597 symlinked into a proper repository before maven is run. Maven is instructed
7598 to use that repository for the build and installs built artifacts there.
7599 Changed files are copied to the @file{lib/m2} directory of the package output.
7601 You can specify a @file{pom.xml} file with the @code{#:pom-file} argument,
7602 or let the build system use the default @file{pom.xml} file in the sources.
7604 In case you need to specify a dependency's version manually, you can use the
7605 @code{#:local-packages} argument. It takes an association list where the key
7606 is the groupId of the package and its value is an association list where the
7607 key is the artifactId of the package and its value is the version you want to
7608 override in the @file{pom.xml}.
7610 Some packages use dependencies or plugins that are not useful at runtime nor
7611 at build time in Guix. You can alter the @file{pom.xml} file to remove them
7612 using the @code{#:exclude} argument. Its value is an association list where
7613 the key is the groupId of the plugin or dependency you want to remove, and
7614 the value is a list of artifactId you want to remove.
7616 You can override the default @code{jdk} and @code{maven} packages with the
7617 corresponding argument, @code{#:jdk} and @code{#:maven}.
7619 The @code{#:maven-plugins} argument is a list of maven plugins used during
7620 the build, with the same format as the @code{inputs} fields of the package
7621 declaration. Its default value is @code{(default-maven-plugins)} which is
7625 @defvr {Scheme Variable} minify-build-system
7626 This variable is exported by @code{(guix build-system minify)}. It
7627 implements a minification procedure for simple JavaScript packages.
7629 It adds @code{uglify-js} to the set of inputs and uses it to compress
7630 all JavaScript files in the @file{src} directory. A different minifier
7631 package can be specified with the @code{#:uglify-js} parameter, but it
7632 is expected that the package writes the minified code to the standard
7635 When the input JavaScript files are not all located in the @file{src}
7636 directory, the parameter @code{#:javascript-files} can be used to
7637 specify a list of file names to feed to the minifier.
7640 @defvr {Scheme Variable} ocaml-build-system
7641 This variable is exported by @code{(guix build-system ocaml)}. It implements
7642 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
7643 of choosing the correct set of commands to run for each package. OCaml
7644 packages can expect many different commands to be run. This build system will
7647 When the package has a @file{setup.ml} file present at the top-level, it will
7648 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
7649 @code{ocaml setup.ml -install}. The build system will assume that this file
7650 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
7651 care of setting the prefix and enabling tests if they are not disabled. You
7652 can pass configure and build flags with the @code{#:configure-flags} and
7653 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
7654 set of flags used to enable tests. The @code{#:use-make?} key can be used to
7655 bypass this system in the build and install phases.
7657 When the package has a @file{configure} file, it is assumed that it is a
7658 hand-made configure script that requires a different argument format than
7659 in the @code{gnu-build-system}. You can add more flags with the
7660 @code{#:configure-flags} key.
7662 When the package has a @file{Makefile} file (or @code{#:use-make?} is
7663 @code{#t}), it will be used and more flags can be passed to the build and
7664 install phases with the @code{#:make-flags} key.
7666 Finally, some packages do not have these files and use a somewhat standard
7667 location for its build system. In that case, the build system will run
7668 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
7669 providing the path to the required findlib module. Additional flags can
7670 be passed via the @code{#:build-flags} key. Install is taken care of by
7671 @command{opam-installer}. In this case, the @code{opam} package must
7672 be added to the @code{native-inputs} field of the package definition.
7674 Note that most OCaml packages assume they will be installed in the same
7675 directory as OCaml, which is not what we want in guix. In particular, they
7676 will install @file{.so} files in their module's directory, which is usually
7677 fine because it is in the OCaml compiler directory. In guix though, these
7678 libraries cannot be found and we use @env{CAML_LD_LIBRARY_PATH}. This
7679 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
7680 @file{.so} libraries should be installed.
7683 @defvr {Scheme Variable} python-build-system
7684 This variable is exported by @code{(guix build-system python)}. It
7685 implements the more or less standard build procedure used by Python
7686 packages, which consists in running @code{python setup.py build} and
7687 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
7689 For packages that install stand-alone Python programs under @code{bin/},
7690 it takes care of wrapping these programs so that their @env{PYTHONPATH}
7691 environment variable points to all the Python libraries they depend on.
7693 Which Python package is used to perform the build can be specified with
7694 the @code{#:python} parameter. This is a useful way to force a package
7695 to be built for a specific version of the Python interpreter, which
7696 might be necessary if the package is only compatible with a single
7697 interpreter version.
7699 By default guix calls @code{setup.py} under control of
7700 @code{setuptools}, much like @command{pip} does. Some packages are not
7701 compatible with setuptools (and pip), thus you can disable this by
7702 setting the @code{#:use-setuptools?} parameter to @code{#f}.
7705 @defvr {Scheme Variable} perl-build-system
7706 This variable is exported by @code{(guix build-system perl)}. It
7707 implements the standard build procedure for Perl packages, which either
7708 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
7709 followed by @code{Build} and @code{Build install}; or in running
7710 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
7711 @code{make} and @code{make install}, depending on which of
7712 @code{Build.PL} or @code{Makefile.PL} is present in the package
7713 distribution. Preference is given to the former if both @code{Build.PL}
7714 and @code{Makefile.PL} exist in the package distribution. This
7715 preference can be reversed by specifying @code{#t} for the
7716 @code{#:make-maker?} parameter.
7718 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
7719 passes flags specified by the @code{#:make-maker-flags} or
7720 @code{#:module-build-flags} parameter, respectively.
7722 Which Perl package is used can be specified with @code{#:perl}.
7725 @defvr {Scheme Variable} qt-build-system
7726 This variable is exported by @code{(guix build-system qt)}. It
7727 is intended for use with applications using Qt or KDE.
7729 This build system adds the following two phases to the ones defined by
7730 @code{cmake-build-system}:
7734 The phase @code{check-setup} prepares the environment for running
7735 the checks as commonly used by Qt test programs.
7736 For now this only sets some environment variables:
7737 @code{QT_QPA_PLATFORM=offscreen},
7738 @code{DBUS_FATAL_WARNINGS=0} and
7739 @code{CTEST_OUTPUT_ON_FAILURE=1}.
7741 This phase is added before the @code{check} phase.
7742 It's a separate phase to ease adjusting if necessary.
7745 The phase @code{qt-wrap}
7746 searches for Qt5 plugin paths, QML paths and some XDG in the inputs
7747 and output. In case some path is found, all programs in the output's
7748 @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
7749 are wrapped in scripts defining the necessary environment variables.
7751 It is possible to exclude specific package outputs from that wrapping process
7752 by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
7753 This is useful when an output is known not to contain any Qt binaries, and
7754 where wrapping would gratuitously add a dependency of that output on Qt, KDE,
7757 This phase is added after the @code{install} phase.
7761 @defvr {Scheme Variable} r-build-system
7762 This variable is exported by @code{(guix build-system r)}. It
7763 implements the build procedure used by @uref{https://r-project.org, R}
7764 packages, which essentially is little more than running @samp{R CMD
7765 INSTALL --library=/gnu/store/@dots{}} in an environment where
7766 @env{R_LIBS_SITE} contains the paths to all R package inputs. Tests are
7767 run after installation using the R function
7768 @code{tools::testInstalledPackage}.
7771 @defvr {Scheme Variable} rakudo-build-system
7772 This variable is exported by @code{(guix build-system rakudo)}. It
7773 implements the build procedure used by @uref{https://rakudo.org/,
7774 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
7775 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
7776 installs the binaries, library files and the resources, as well as wrap
7777 the files under the @code{bin/} directory. Tests can be skipped by
7778 passing @code{#f} to the @code{tests?} parameter.
7780 Which rakudo package is used can be specified with @code{rakudo}.
7781 Which perl6-tap-harness package used for the tests can be specified with
7782 @code{#:prove6} or removed by passing @code{#f} to the
7783 @code{with-prove6?} parameter.
7784 Which perl6-zef package used for tests and installing can be specified
7785 with @code{#:zef} or removed by passing @code{#f} to the
7786 @code{with-zef?} parameter.
7789 @defvr {Scheme Variable} texlive-build-system
7790 This variable is exported by @code{(guix build-system texlive)}. It is
7791 used to build TeX packages in batch mode with a specified engine. The
7792 build system sets the @env{TEXINPUTS} variable to find all TeX source
7793 files in the inputs.
7795 By default it runs @code{luatex} on all files ending on @code{ins}. A
7796 different engine and format can be specified with the
7797 @code{#:tex-format} argument. Different build targets can be specified
7798 with the @code{#:build-targets} argument, which expects a list of file
7799 names. The build system adds only @code{texlive-bin} and
7800 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
7801 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
7802 and @code{#:texlive-latex-base}, respectively.
7804 The @code{#:tex-directory} parameter tells the build system where to
7805 install the built files under the texmf tree.
7808 @defvr {Scheme Variable} ruby-build-system
7809 This variable is exported by @code{(guix build-system ruby)}. It
7810 implements the RubyGems build procedure used by Ruby packages, which
7811 involves running @code{gem build} followed by @code{gem install}.
7813 The @code{source} field of a package that uses this build system
7814 typically references a gem archive, since this is the format that Ruby
7815 developers use when releasing their software. The build system unpacks
7816 the gem archive, potentially patches the source, runs the test suite,
7817 repackages the gem, and installs it. Additionally, directories and
7818 tarballs may be referenced to allow building unreleased gems from Git or
7819 a traditional source release tarball.
7821 Which Ruby package is used can be specified with the @code{#:ruby}
7822 parameter. A list of additional flags to be passed to the @command{gem}
7823 command can be specified with the @code{#:gem-flags} parameter.
7826 @defvr {Scheme Variable} waf-build-system
7827 This variable is exported by @code{(guix build-system waf)}. It
7828 implements a build procedure around the @code{waf} script. The common
7829 phases---@code{configure}, @code{build}, and @code{install}---are
7830 implemented by passing their names as arguments to the @code{waf}
7833 The @code{waf} script is executed by the Python interpreter. Which
7834 Python package is used to run the script can be specified with the
7835 @code{#:python} parameter.
7838 @defvr {Scheme Variable} scons-build-system
7839 This variable is exported by @code{(guix build-system scons)}. It
7840 implements the build procedure used by the SCons software construction
7841 tool. This build system runs @code{scons} to build the package,
7842 @code{scons test} to run tests, and then @code{scons install} to install
7845 Additional flags to be passed to @code{scons} can be specified with the
7846 @code{#:scons-flags} parameter. The default build and install targets
7847 can be overridden with @code{#:build-targets} and
7848 @code{#:install-targets} respectively. The version of Python used to
7849 run SCons can be specified by selecting the appropriate SCons package
7850 with the @code{#:scons} parameter.
7853 @defvr {Scheme Variable} haskell-build-system
7854 This variable is exported by @code{(guix build-system haskell)}. It
7855 implements the Cabal build procedure used by Haskell packages, which
7856 involves running @code{runhaskell Setup.hs configure
7857 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
7858 Instead of installing the package by running @code{runhaskell Setup.hs
7859 install}, to avoid trying to register libraries in the read-only
7860 compiler store directory, the build system uses @code{runhaskell
7861 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
7862 addition, the build system generates the package documentation by
7863 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
7864 is passed. Optional Haddock parameters can be passed with the help of
7865 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
7866 not found, the build system looks for @code{Setup.lhs} instead.
7868 Which Haskell compiler is used can be specified with the @code{#:haskell}
7869 parameter which defaults to @code{ghc}.
7872 @defvr {Scheme Variable} dub-build-system
7873 This variable is exported by @code{(guix build-system dub)}. It
7874 implements the Dub build procedure used by D packages, which
7875 involves running @code{dub build} and @code{dub run}.
7876 Installation is done by copying the files manually.
7878 Which D compiler is used can be specified with the @code{#:ldc}
7879 parameter which defaults to @code{ldc}.
7882 @defvr {Scheme Variable} emacs-build-system
7883 This variable is exported by @code{(guix build-system emacs)}. It
7884 implements an installation procedure similar to the packaging system
7885 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
7887 It first creates the @code{@code{package}-autoloads.el} file, then it
7888 byte compiles all Emacs Lisp files. Differently from the Emacs
7889 packaging system, the Info documentation files are moved to the standard
7890 documentation directory and the @file{dir} file is deleted. The Elisp
7891 package files are installed directly under @file{share/emacs/site-lisp}.
7894 @defvr {Scheme Variable} font-build-system
7895 This variable is exported by @code{(guix build-system font)}. It
7896 implements an installation procedure for font packages where upstream
7897 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
7898 need to be copied into place. It copies font files to standard
7899 locations in the output directory.
7902 @defvr {Scheme Variable} meson-build-system
7903 This variable is exported by @code{(guix build-system meson)}. It
7904 implements the build procedure for packages that use
7905 @url{https://mesonbuild.com, Meson} as their build system.
7907 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
7908 of inputs, and they can be changed with the parameters @code{#:meson}
7909 and @code{#:ninja} if needed. The default Meson is
7910 @code{meson-for-build}, which is special because it doesn't clear the
7911 @code{RUNPATH} of binaries and libraries when they are installed.
7913 This build system is an extension of @code{gnu-build-system}, but with the
7914 following phases changed to some specific for Meson:
7919 The phase runs @code{meson} with the flags specified in
7920 @code{#:configure-flags}. The flag @option{--buildtype} is always set to
7921 @code{debugoptimized} unless something else is specified in
7922 @code{#:build-type}.
7925 The phase runs @code{ninja} to build the package in parallel by default, but
7926 this can be changed with @code{#:parallel-build?}.
7929 The phase runs @code{ninja} with the target specified in @code{#:test-target},
7930 which is @code{"test"} by default.
7933 The phase runs @code{ninja install} and can not be changed.
7936 Apart from that, the build system also adds the following phases:
7941 This phase ensures that all binaries can find the libraries they need.
7942 It searches for required libraries in subdirectories of the package being
7943 built, and adds those to @code{RUNPATH} where needed. It also removes
7944 references to libraries left over from the build phase by
7945 @code{meson-for-build}, such as test dependencies, that aren't actually
7946 required for the program to run.
7948 @item glib-or-gtk-wrap
7949 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
7950 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
7952 @item glib-or-gtk-compile-schemas
7953 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
7954 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
7958 @defvr {Scheme Variable} linux-module-build-system
7959 @code{linux-module-build-system} allows building Linux kernel modules.
7961 @cindex build phases
7962 This build system is an extension of @code{gnu-build-system}, but with the
7963 following phases changed:
7968 This phase configures the environment so that the Linux kernel's Makefile
7969 can be used to build the external kernel module.
7972 This phase uses the Linux kernel's Makefile in order to build the external
7976 This phase uses the Linux kernel's Makefile in order to install the external
7980 It is possible and useful to specify the Linux kernel to use for building
7981 the module (in the @code{arguments} form of a package using the
7982 @code{linux-module-build-system}, use the key @code{#:linux} to specify it).
7985 @defvr {Scheme Variable} node-build-system
7986 This variable is exported by @code{(guix build-system node)}. It
7987 implements the build procedure used by @uref{https://nodejs.org,
7988 Node.js}, which implements an approximation of the @code{npm install}
7989 command, followed by an @code{npm test} command.
7991 Which Node.js package is used to interpret the @code{npm} commands can
7992 be specified with the @code{#:node} parameter which defaults to
7996 Lastly, for packages that do not need anything as sophisticated, a
7997 ``trivial'' build system is provided. It is trivial in the sense that
7998 it provides basically no support: it does not pull any implicit inputs,
7999 and does not have a notion of build phases.
8001 @defvr {Scheme Variable} trivial-build-system
8002 This variable is exported by @code{(guix build-system trivial)}.
8004 This build system requires a @code{#:builder} argument. This argument
8005 must be a Scheme expression that builds the package output(s)---as
8006 with @code{build-expression->derivation} (@pxref{Derivations,
8007 @code{build-expression->derivation}}).
8011 @section Build Phases
8013 @cindex build phases, for packages
8014 Almost all package build systems implement a notion @dfn{build phases}:
8015 a sequence of actions that the build system executes, when you build the
8016 package, leading to the installed byproducts in the store. A notable
8017 exception is the ``bare-bones'' @code{trivial-build-system}
8018 (@pxref{Build Systems}).
8020 As discussed in the previous section, those build systems provide a
8021 standard list of phases. For @code{gnu-build-system}, the standard
8022 phases include an @code{unpack} phase to unpack the source code tarball,
8023 a @command{configure} phase to run @code{./configure}, a @code{build}
8024 phase to run @command{make}, and (among others) an @code{install} phase
8025 to run @command{make install}; @pxref{Build Systems}, for a more
8026 detailed view of these phases. Likewise, @code{cmake-build-system}
8027 inherits these phases, but its @code{configure} phase runs
8028 @command{cmake} instead of @command{./configure}. Other build systems,
8029 such as @code{python-build-system}, have a wholly different list of
8030 standard phases. All this code runs on the @dfn{build side}: it is
8031 evaluated when you actually build the package, in a dedicated build
8032 process spawned by the build daemon (@pxref{Invoking guix-daemon}).
8034 Build phases are represented as association lists or ``alists''
8035 (@pxref{Association Lists,,, guile, GNU Guile Reference Manual}) where
8036 each key is a symbol for the name of the phase and the associated value
8037 is a procedure that accepts an arbitrary number of arguments. By
8038 convention, those procedures receive information about the build in the
8039 form of @dfn{keyword parameters}, which they can use or ignore.
8041 For example, here is how @code{(guix build gnu-build-system)} defines
8042 @code{%standard-phases}, the variable holding its alist of build
8043 phases@footnote{We present a simplified view of those build phases, but
8044 do take a look at @code{(guix build gnu-build-system)} to see all the
8048 ;; The build phases of 'gnu-build-system'.
8050 (define* (unpack #:key source #:allow-other-keys)
8051 ;; Extract the source tarball.
8052 (invoke "tar" "xvf" source))
8054 (define* (configure #:key outputs #:allow-other-keys)
8055 ;; Run the 'configure' script. Install to output "out".
8056 (let ((out (assoc-ref outputs "out")))
8057 (invoke "./configure"
8058 (string-append "--prefix=" out))))
8060 (define* (build #:allow-other-keys)
8064 (define* (check #:key (test-target "check") (tests? #true)
8066 ;; Run the test suite.
8068 (invoke "make" test-target)
8069 (display "test suite not run\n")))
8071 (define* (install #:allow-other-keys)
8072 ;; Install files to the prefix 'configure' specified.
8073 (invoke "make" "install"))
8075 (define %standard-phases
8076 ;; The list of standard phases (quite a few are omitted
8077 ;; for brevity). Each element is a symbol/procedure pair.
8078 (list (cons 'unpack unpack)
8079 (cons 'configure configure)
8082 (cons 'install install)))
8085 This shows how @code{%standard-phases} is defined as a list of
8086 symbol/procedure pairs (@pxref{Pairs,,, guile, GNU Guile Reference
8087 Manual}). The first pair associates the @code{unpack} procedure with
8088 the @code{unpack} symbol---a name; the second pair defines the
8089 @code{configure} phase similarly, and so on. When building a package
8090 that uses @code{gnu-build-system} with its default list of phases, those
8091 phases are executed sequentially. You can see the name of each phase
8092 started and completed in the build log of packages that you build.
8094 Let's now look at the procedures themselves. Each one is defined with
8095 @code{define*}: @code{#:key} lists keyword parameters the procedure
8096 accepts, possibly with a default value, and @code{#:allow-other-keys}
8097 specifies that other keyword parameters are ignored (@pxref{Optional
8098 Arguments,,, guile, GNU Guile Reference Manual}).
8100 The @code{unpack} procedure honors the @code{source} parameter, which
8101 the build system uses to pass the file name of the source tarball (or
8102 version control checkout), and it ignores other parameters. The
8103 @code{configure} phase only cares about the @code{outputs} parameter, an
8104 alist mapping package output names to their store file name
8105 (@pxref{Packages with Multiple Outputs}). It extracts the file name of
8106 for @code{out}, the default output, and passes it to
8107 @command{./configure} as the installation prefix, meaning that
8108 @command{make install} will eventually copy all the files in that
8109 directory (@pxref{Configuration, configuration and makefile
8110 conventions,, standards, GNU Coding Standards}). @code{build} and
8111 @code{install} ignore all their arguments. @code{check} honors the
8112 @code{test-target} argument, which specifies the name of the Makefile
8113 target to run tests; it prints a message and skips tests when
8114 @code{tests?} is false.
8116 @cindex build phases, customizing
8117 The list of phases used for a particular package can be changed with the
8118 @code{#:phases} parameter of the build system. Changing the set of
8119 build phases boils down to building a new alist of phases based on the
8120 @code{%standard-phases} alist described above. This can be done with
8121 standard alist procedures such as @code{alist-delete} (@pxref{SRFI-1
8122 Association Lists,,, guile, GNU Guile Reference Manual}); however, it is
8123 more convenient to do so with @code{modify-phases} (@pxref{Build
8124 Utilities, @code{modify-phases}}).
8126 Here is an example of a package definition that removes the
8127 @code{configure} phase of @code{%standard-phases} and inserts a new
8128 phase before the @code{build} phase, called
8129 @code{set-prefix-in-makefile}:
8132 (define-public example
8135 ;; other fields omitted
8136 (build-system gnu-build-system)
8138 '(#:phases (modify-phases %standard-phases
8140 (add-before 'build 'set-prefix-in-makefile
8141 (lambda* (#:key outputs #:allow-other-keys)
8142 ;; Modify the makefile so that its
8143 ;; 'PREFIX' variable points to "out".
8144 (let ((out (assoc-ref outputs "out")))
8145 (substitute* "Makefile"
8147 (string-append "PREFIX = "
8152 The new phase that is inserted is written as an anonymous procedure,
8153 introduced with @code{lambda*}; it honors the @code{outputs} parameter
8154 we have seen before. @xref{Build Utilities}, for more about the helpers
8155 used by this phase, and for more examples of @code{modify-phases}.
8157 @cindex code staging
8158 @cindex staging, of code
8159 Keep in mind that build phases are code evaluated at the time the
8160 package is actually built. This explains why the whole
8161 @code{modify-phases} expression above is quoted (it comes after the
8162 @code{'} or apostrophe): it is @dfn{staged} for later execution.
8163 @xref{G-Expressions}, for an explanation of code staging and the
8164 @dfn{code strata} involved.
8166 @node Build Utilities
8167 @section Build Utilities
8169 As soon as you start writing non-trivial package definitions
8170 (@pxref{Defining Packages}) or other build actions
8171 (@pxref{G-Expressions}), you will likely start looking for helpers for
8172 ``shell-like'' actions---creating directories, copying and deleting
8173 files recursively, manipulating build phases, and so on. The
8174 @code{(guix build utils)} module provides such utility procedures.
8176 Most build systems load @code{(guix build utils)} (@pxref{Build
8177 Systems}). Thus, when writing custom build phases for your package
8178 definitions, you can usually assume those procedures are in scope.
8180 When writing G-expressions, you can import @code{(guix build utils)} on
8181 the ``build side'' using @code{with-imported-modules} and then put it in
8182 scope with the @code{use-modules} form (@pxref{Using Guile Modules,,,
8183 guile, GNU Guile Reference Manual}):
8186 (with-imported-modules '((guix build utils)) ;import it
8187 (computed-file "empty-tree"
8190 (use-modules (guix build utils))
8192 ;; Happily use its 'mkdir-p' procedure.
8193 (mkdir-p (string-append #$output "/a/b/c")))))
8196 The remainder of this section is the reference for most of the utility
8197 procedures provided by @code{(guix build utils)}.
8199 @c TODO Document what's missing.
8201 @subsection Dealing with Store File Names
8203 This section documents procedures that deal with store file names.
8205 @deffn {Scheme Procedure} %store-directory
8206 Return the directory name of the store.
8209 @deffn {Scheme Procedure} store-file-name? @var{file}
8210 Return true if @var{file} is in the store.
8213 @deffn {Scheme Procedure} strip-store-file-name @var{file}
8214 Strip the @file{/gnu/store} and hash from @var{file}, a store file name.
8215 The result is typically a @code{"@var{package}-@var{version}"} string.
8218 @deffn {Scheme Procedure} package-name->name+version @var{name}
8219 Given @var{name}, a package name like @code{"foo-0.9.1b"}, return two
8220 values: @code{"foo"} and @code{"0.9.1b"}. When the version part is
8221 unavailable, @var{name} and @code{#f} are returned. The first hyphen
8222 followed by a digit is considered to introduce the version part.
8225 @subsection File Types
8227 The procedures below deal with files and file types.
8229 @deffn {Scheme Procedure} directory-exists? @var{dir}
8230 Return @code{#t} if @var{dir} exists and is a directory.
8233 @deffn {Scheme Procedure} executable-file? @var{file}
8234 Return @code{#t} if @var{file} exists and is executable.
8237 @deffn {Scheme Procedure} symbolic-link? @var{file}
8238 Return @code{#t} if @var{file} is a symbolic link (aka. a ``symlink'').
8241 @deffn {Scheme Procedure} elf-file? @var{file}
8242 @deffnx {Scheme Procedure} ar-file? @var{file}
8243 @deffnx {Scheme Procedure} gzip-file? @var{file}
8244 Return @code{#t} if @var{file} is, respectively, an ELF file, an
8245 @code{ar} archive (such as a @file{.a} static library), or a gzip file.
8248 @deffn {Scheme Procedure} reset-gzip-timestamp @var{file} [#:keep-mtime? #t]
8249 If @var{file} is a gzip file, reset its embedded timestamp (as with
8250 @command{gzip --no-name}) and return true. Otherwise return @code{#f}.
8251 When @var{keep-mtime?} is true, preserve @var{file}'s modification time.
8254 @subsection File Manipulation
8256 The following procedures and macros help create, modify, and delete
8257 files. They provide functionality comparable to common shell utilities
8258 such as @command{mkdir -p}, @command{cp -r}, @command{rm -r}, and
8259 @command{sed}. They complement Guile's extensive, but low-level, file
8260 system interface (@pxref{POSIX,,, guile, GNU Guile Reference Manual}).
8262 @deffn {Scheme Syntax} with-directory-excursion @var{directory} @var{body}@dots{}
8263 Run @var{body} with @var{directory} as the process's current directory.
8265 Essentially, this macro changes the current directory to @var{directory}
8266 before evaluating @var{body}, using @code{chdir} (@pxref{Processes,,,
8267 guile, GNU Guile Reference Manual}). It changes back to the initial
8268 directory when the dynamic extent of @var{body} is left, be it @i{via}
8269 normal procedure return or @i{via} a non-local exit such as an
8273 @deffn {Scheme Procedure} mkdir-p @var{dir}
8274 Create directory @var{dir} and all its ancestors.
8277 @deffn {Scheme Procedure} install-file @var{file} @var{directory}
8278 Create @var{directory} if it does not exist and copy @var{file} in there
8279 under the same name.
8282 @deffn {Scheme Procedure} make-file-writable @var{file}
8283 Make @var{file} writable for its owner.
8286 @deffn {Scheme Procedure} copy-recursively @var{source} @var{destination} @
8287 [#:log (current-output-port)] [#:follow-symlinks? #f] [#:keep-mtime? #f]
8288 Copy @var{source} directory to @var{destination}. Follow symlinks if
8289 @var{follow-symlinks?} is true; otherwise, just preserve them. When
8290 @var{keep-mtime?} is true, keep the modification time of the files in
8291 @var{source} on those of @var{destination}. Write verbose output to the
8295 @deffn {Scheme Procedure} delete-file-recursively @var{dir} @
8296 [#:follow-mounts? #f]
8297 Delete @var{dir} recursively, like @command{rm -rf}, without following
8298 symlinks. Don't follow mount points either, unless @var{follow-mounts?}
8299 is true. Report but ignore errors.
8302 @deffn {Scheme Syntax} substitute* @var{file} @
8303 ((@var{regexp} @var{match-var}@dots{}) @var{body}@dots{}) @dots{}
8304 Substitute @var{regexp} in @var{file} by the string returned by
8305 @var{body}. @var{body} is evaluated with each @var{match-var} bound to
8306 the corresponding positional regexp sub-expression. For example:
8312 (("foo([a-z]+)bar(.*)$" all letters end)
8313 (string-append "baz" letter end)))
8316 Here, anytime a line of @var{file} contains @code{hello}, it is replaced
8317 by @code{good morning}. Anytime a line of @var{file} matches the second
8318 regexp, @code{all} is bound to the complete match, @code{letters} is bound
8319 to the first sub-expression, and @code{end} is bound to the last one.
8321 When one of the @var{match-var} is @code{_}, no variable is bound to the
8322 corresponding match substring.
8324 Alternatively, @var{file} may be a list of file names, in which case
8325 they are all subject to the substitutions.
8327 Be careful about using @code{$} to match the end of a line; by itself it
8328 won't match the terminating newline of a line.
8331 @subsection File Search
8333 @cindex file, searching
8334 This section documents procedures to search and filter files.
8336 @deffn {Scheme Procedure} file-name-predicate @var{regexp}
8337 Return a predicate that returns true when passed a file name whose base
8338 name matches @var{regexp}.
8341 @deffn {Scheme Procedure} find-files @var{dir} [@var{pred}] @
8342 [#:stat lstat] [#:directories? #f] [#:fail-on-error? #f]
8343 Return the lexicographically sorted list of files under @var{dir} for
8344 which @var{pred} returns true. @var{pred} is passed two arguments: the
8345 absolute file name, and its stat buffer; the default predicate always
8346 returns true. @var{pred} can also be a regular expression, in which
8347 case it is equivalent to @code{(file-name-predicate @var{pred})}.
8348 @var{stat} is used to obtain file information; using @code{lstat} means
8349 that symlinks are not followed. If @var{directories?} is true, then
8350 directories will also be included. If @var{fail-on-error?} is true,
8351 raise an exception upon error.
8354 Here are a few examples where we assume that the current directory is
8355 the root of the Guix source tree:
8358 ;; List all the regular files in the current directory.
8360 @result{} ("./.dir-locals.el" "./.gitignore" @dots{})
8362 ;; List all the .scm files under gnu/services.
8363 (find-files "gnu/services" "\\.scm$")
8364 @result{} ("gnu/services/admin.scm" "gnu/services/audio.scm" @dots{})
8366 ;; List ar files in the current directory.
8367 (find-files "." (lambda (file stat) (ar-file? file)))
8368 @result{} ("./libformat.a" "./libstore.a" @dots{})
8371 @deffn {Scheme Procedure} which @var{program}
8372 Return the complete file name for @var{program} as found in
8373 @code{$PATH}, or @code{#f} if @var{program} could not be found.
8376 @subsection Build Phases
8378 @cindex build phases
8379 The @code{(guix build utils)} also contains tools to manipulate build
8380 phases as used by build systems (@pxref{Build Systems}). Build phases
8381 are represented as association lists or ``alists'' (@pxref{Association
8382 Lists,,, guile, GNU Guile Reference Manual}) where each key is a symbol
8383 naming the phase and the associated value is a procedure (@pxref{Build
8386 Guile core and the @code{(srfi srfi-1)} module both provide tools to
8387 manipulate alists. The @code{(guix build utils)} module complements
8388 those with tools written with build phases in mind.
8390 @cindex build phases, modifying
8391 @deffn {Scheme Syntax} modify-phases @var{phases} @var{clause}@dots{}
8392 Modify @var{phases} sequentially as per each @var{clause}, which may
8393 have one of the following forms:
8396 (delete @var{old-phase-name})
8397 (replace @var{old-phase-name} @var{new-phase})
8398 (add-before @var{old-phase-name} @var{new-phase-name} @var{new-phase})
8399 (add-after @var{old-phase-name} @var{new-phase-name} @var{new-phase})
8402 Where every @var{phase-name} above is an expression evaluating to a
8403 symbol, and @var{new-phase} an expression evaluating to a procedure.
8406 The example below is taken from the definition of the @code{grep}
8407 package. It adds a phase to run after the @code{install} phase, called
8408 @code{fix-egrep-and-fgrep}. That phase is a procedure (@code{lambda*}
8409 is for anonymous procedures) that takes a @code{#:outputs} keyword
8410 argument and ignores extra keyword arguments (@pxref{Optional
8411 Arguments,,, guile, GNU Guile Reference Manual}, for more on
8412 @code{lambda*} and optional and keyword arguments.) The phase uses
8413 @code{substitute*} to modify the installed @file{egrep} and @file{fgrep}
8414 scripts so that they refer to @code{grep} by its absolute file name:
8417 (modify-phases %standard-phases
8418 (add-after 'install 'fix-egrep-and-fgrep
8419 ;; Patch 'egrep' and 'fgrep' to execute 'grep' via its
8420 ;; absolute file name instead of searching for it in $PATH.
8421 (lambda* (#:key outputs #:allow-other-keys)
8422 (let* ((out (assoc-ref outputs "out"))
8423 (bin (string-append out "/bin")))
8424 (substitute* (list (string-append bin "/egrep")
8425 (string-append bin "/fgrep"))
8427 (string-append "exec " bin "/grep")))
8431 In the example below, phases are modified in two ways: the standard
8432 @code{configure} phase is deleted, presumably because the package does
8433 not have a @file{configure} script or anything similar, and the default
8434 @code{install} phase is replaced by one that manually copies the
8435 executable files to be installed:
8438 (modify-phases %standard-phases
8439 (delete 'configure) ;no 'configure' script
8441 (lambda* (#:key outputs #:allow-other-keys)
8442 ;; The package's Makefile doesn't provide an "install"
8443 ;; rule so do it by ourselves.
8444 (let ((bin (string-append (assoc-ref outputs "out")
8446 (install-file "footswitch" bin)
8447 (install-file "scythe" bin)
8451 @c TODO: Add more examples.
8460 Conceptually, the @dfn{store} is the place where derivations that have
8461 been built successfully are stored---by default, @file{/gnu/store}.
8462 Sub-directories in the store are referred to as @dfn{store items} or
8463 sometimes @dfn{store paths}. The store has an associated database that
8464 contains information such as the store paths referred to by each store
8465 path, and the list of @emph{valid} store items---results of successful
8466 builds. This database resides in @file{@var{localstatedir}/guix/db},
8467 where @var{localstatedir} is the state directory specified @i{via}
8468 @option{--localstatedir} at configure time, usually @file{/var}.
8470 The store is @emph{always} accessed by the daemon on behalf of its clients
8471 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
8472 connect to the daemon over a Unix-domain socket, send requests to it,
8473 and read the result---these are remote procedure calls, or RPCs.
8476 Users must @emph{never} modify files under @file{/gnu/store} directly.
8477 This would lead to inconsistencies and break the immutability
8478 assumptions of Guix's functional model (@pxref{Introduction}).
8480 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
8481 how to check the integrity of the store and attempt recovery from
8482 accidental modifications.
8485 The @code{(guix store)} module provides procedures to connect to the
8486 daemon, and to perform RPCs. These are described below. By default,
8487 @code{open-connection}, and thus all the @command{guix} commands,
8488 connect to the local daemon or to the URI specified by the
8489 @env{GUIX_DAEMON_SOCKET} environment variable.
8491 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
8492 When set, the value of this variable should be a file name or a URI
8493 designating the daemon endpoint. When it is a file name, it denotes a
8494 Unix-domain socket to connect to. In addition to file names, the
8495 supported URI schemes are:
8500 These are for Unix-domain sockets.
8501 @code{file:///var/guix/daemon-socket/socket} is equivalent to
8502 @file{/var/guix/daemon-socket/socket}.
8505 @cindex daemon, remote access
8506 @cindex remote access to the daemon
8507 @cindex daemon, cluster setup
8508 @cindex clusters, daemon setup
8509 These URIs denote connections over TCP/IP, without encryption nor
8510 authentication of the remote host. The URI must specify the host name
8511 and optionally a port number (by default port 44146 is used):
8514 guix://master.guix.example.org:1234
8517 This setup is suitable on local networks, such as clusters, where only
8518 trusted nodes may connect to the build daemon at
8519 @code{master.guix.example.org}.
8521 The @option{--listen} option of @command{guix-daemon} can be used to
8522 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
8523 @option{--listen}}).
8526 @cindex SSH access to build daemons
8527 These URIs allow you to connect to a remote daemon over SSH. This
8528 feature requires Guile-SSH (@pxref{Requirements}) and a working
8529 @command{guile} binary in @env{PATH} on the destination machine. It
8530 supports public key and GSSAPI authentication. A typical URL might look
8534 ssh://charlie@@guix.example.org:22
8537 As for @command{guix copy}, the usual OpenSSH client configuration files
8538 are honored (@pxref{Invoking guix copy}).
8541 Additional URI schemes may be supported in the future.
8543 @c XXX: Remove this note when the protocol incurs fewer round trips
8544 @c and when (guix derivations) no longer relies on file system access.
8546 The ability to connect to remote build daemons is considered
8547 experimental as of @value{VERSION}. Please get in touch with us to
8548 share any problems or suggestions you may have (@pxref{Contributing}).
8552 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
8553 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
8554 @var{reserve-space?} is true, instruct it to reserve a little bit of
8555 extra space on the file system so that the garbage collector can still
8556 operate should the disk become full. Return a server object.
8558 @var{file} defaults to @code{%default-socket-path}, which is the normal
8559 location given the options that were passed to @command{configure}.
8562 @deffn {Scheme Procedure} close-connection @var{server}
8563 Close the connection to @var{server}.
8566 @defvr {Scheme Variable} current-build-output-port
8567 This variable is bound to a SRFI-39 parameter, which refers to the port
8568 where build and error logs sent by the daemon should be written.
8571 Procedures that make RPCs all take a server object as their first
8574 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
8575 @cindex invalid store items
8576 Return @code{#t} when @var{path} designates a valid store item and
8577 @code{#f} otherwise (an invalid item may exist on disk but still be
8578 invalid, for instance because it is the result of an aborted or failed
8581 A @code{&store-protocol-error} condition is raised if @var{path} is not
8582 prefixed by the store directory (@file{/gnu/store}).
8585 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
8586 Add @var{text} under file @var{name} in the store, and return its store
8587 path. @var{references} is the list of store paths referred to by the
8588 resulting store path.
8591 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
8593 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
8594 file names, or derivation/output pairs, using the specified
8595 @var{mode}---@code{(build-mode normal)} by default.
8598 Note that the @code{(guix monads)} module provides a monad as well as
8599 monadic versions of the above procedures, with the goal of making it
8600 more convenient to work with code that accesses the store (@pxref{The
8604 @i{This section is currently incomplete.}
8607 @section Derivations
8610 Low-level build actions and the environment in which they are performed
8611 are represented by @dfn{derivations}. A derivation contains the
8612 following pieces of information:
8616 The outputs of the derivation---derivations produce at least one file or
8617 directory in the store, but may produce more.
8620 @cindex build-time dependencies
8621 @cindex dependencies, build-time
8622 The inputs of the derivations---i.e., its build-time dependencies---which may
8623 be other derivations or plain files in the store (patches, build scripts,
8627 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
8630 The file name of a build script in the store, along with the arguments
8634 A list of environment variables to be defined.
8638 @cindex derivation path
8639 Derivations allow clients of the daemon to communicate build actions to
8640 the store. They exist in two forms: as an in-memory representation,
8641 both on the client- and daemon-side, and as files in the store whose
8642 name end in @file{.drv}---these files are referred to as @dfn{derivation
8643 paths}. Derivations paths can be passed to the @code{build-derivations}
8644 procedure to perform the build actions they prescribe (@pxref{The
8647 @cindex fixed-output derivations
8648 Operations such as file downloads and version-control checkouts for
8649 which the expected content hash is known in advance are modeled as
8650 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
8651 of a fixed-output derivation are independent of its inputs---e.g., a
8652 source code download produces the same result regardless of the download
8653 method and tools being used.
8656 @cindex run-time dependencies
8657 @cindex dependencies, run-time
8658 The outputs of derivations---i.e., the build results---have a set of
8659 @dfn{references}, as reported by the @code{references} RPC or the
8660 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
8661 are the set of run-time dependencies of the build results. References are a
8662 subset of the inputs of the derivation; this subset is automatically computed
8663 by the build daemon by scanning all the files in the outputs.
8665 The @code{(guix derivations)} module provides a representation of
8666 derivations as Scheme objects, along with procedures to create and
8667 otherwise manipulate derivations. The lowest-level primitive to create
8668 a derivation is the @code{derivation} procedure:
8670 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
8671 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
8672 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
8673 [#:system (%current-system)] [#:references-graphs #f] @
8674 [#:allowed-references #f] [#:disallowed-references #f] @
8675 [#:leaked-env-vars #f] [#:local-build? #f] @
8676 [#:substitutable? #t] [#:properties '()]
8677 Build a derivation with the given arguments, and return the resulting
8678 @code{<derivation>} object.
8680 When @var{hash} and @var{hash-algo} are given, a
8681 @dfn{fixed-output derivation} is created---i.e., one whose result is
8682 known in advance, such as a file download. If, in addition,
8683 @var{recursive?} is true, then that fixed output may be an executable
8684 file or a directory and @var{hash} must be the hash of an archive
8685 containing this output.
8687 When @var{references-graphs} is true, it must be a list of file
8688 name/store path pairs. In that case, the reference graph of each store
8689 path is exported in the build environment in the corresponding file, in
8690 a simple text format.
8692 When @var{allowed-references} is true, it must be a list of store items
8693 or outputs that the derivation's output may refer to. Likewise,
8694 @var{disallowed-references}, if true, must be a list of things the
8695 outputs may @emph{not} refer to.
8697 When @var{leaked-env-vars} is true, it must be a list of strings
8698 denoting environment variables that are allowed to ``leak'' from the
8699 daemon's environment to the build environment. This is only applicable
8700 to fixed-output derivations---i.e., when @var{hash} is true. The main
8701 use is to allow variables such as @code{http_proxy} to be passed to
8702 derivations that download files.
8704 When @var{local-build?} is true, declare that the derivation is not a
8705 good candidate for offloading and should rather be built locally
8706 (@pxref{Daemon Offload Setup}). This is the case for small derivations
8707 where the costs of data transfers would outweigh the benefits.
8709 When @var{substitutable?} is false, declare that substitutes of the
8710 derivation's output should not be used (@pxref{Substitutes}). This is
8711 useful, for instance, when building packages that capture details of the
8712 host CPU instruction set.
8714 @var{properties} must be an association list describing ``properties'' of the
8715 derivation. It is kept as-is, uninterpreted, in the derivation.
8719 Here's an example with a shell script as its builder, assuming
8720 @var{store} is an open connection to the daemon, and @var{bash} points
8721 to a Bash executable in the store:
8724 (use-modules (guix utils)
8728 (let ((builder ; add the Bash script to the store
8729 (add-text-to-store store "my-builder.sh"
8730 "echo hello world > $out\n" '())))
8731 (derivation store "foo"
8732 bash `("-e" ,builder)
8733 #:inputs `((,bash) (,builder))
8734 #:env-vars '(("HOME" . "/homeless"))))
8735 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
8738 As can be guessed, this primitive is cumbersome to use directly. A
8739 better approach is to write build scripts in Scheme, of course! The
8740 best course of action for that is to write the build code as a
8741 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
8742 information, @pxref{G-Expressions}.
8744 Once upon a time, @code{gexp->derivation} did not exist and constructing
8745 derivations with build code written in Scheme was achieved with
8746 @code{build-expression->derivation}, documented below. This procedure
8747 is now deprecated in favor of the much nicer @code{gexp->derivation}.
8749 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
8750 @var{name} @var{exp} @
8751 [#:system (%current-system)] [#:inputs '()] @
8752 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
8753 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
8754 [#:references-graphs #f] [#:allowed-references #f] @
8755 [#:disallowed-references #f] @
8756 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
8757 Return a derivation that executes Scheme expression @var{exp} as a
8758 builder for derivation @var{name}. @var{inputs} must be a list of
8759 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
8760 @code{"out"} is assumed. @var{modules} is a list of names of Guile
8761 modules from the current search path to be copied in the store,
8762 compiled, and made available in the load path during the execution of
8763 @var{exp}---e.g., @code{((guix build utils) (guix build
8764 gnu-build-system))}.
8766 @var{exp} is evaluated in an environment where @code{%outputs} is bound
8767 to a list of output/path pairs, and where @code{%build-inputs} is bound
8768 to a list of string/output-path pairs made from @var{inputs}.
8769 Optionally, @var{env-vars} is a list of string pairs specifying the name
8770 and value of environment variables visible to the builder. The builder
8771 terminates by passing the result of @var{exp} to @code{exit}; thus, when
8772 @var{exp} returns @code{#f}, the build is considered to have failed.
8774 @var{exp} is built using @var{guile-for-build} (a derivation). When
8775 @var{guile-for-build} is omitted or is @code{#f}, the value of the
8776 @code{%guile-for-build} fluid is used instead.
8778 See the @code{derivation} procedure for the meaning of
8779 @var{references-graphs}, @var{allowed-references},
8780 @var{disallowed-references}, @var{local-build?}, and
8781 @var{substitutable?}.
8785 Here's an example of a single-output derivation that creates a directory
8786 containing one file:
8789 (let ((builder '(let ((out (assoc-ref %outputs "out")))
8790 (mkdir out) ; create /gnu/store/@dots{}-goo
8791 (call-with-output-file (string-append out "/test")
8793 (display '(hello guix) p))))))
8794 (build-expression->derivation store "goo" builder))
8796 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
8800 @node The Store Monad
8801 @section The Store Monad
8805 The procedures that operate on the store described in the previous
8806 sections all take an open connection to the build daemon as their first
8807 argument. Although the underlying model is functional, they either have
8808 side effects or depend on the current state of the store.
8810 The former is inconvenient: the connection to the build daemon has to be
8811 carried around in all those functions, making it impossible to compose
8812 functions that do not take that parameter with functions that do. The
8813 latter can be problematic: since store operations have side effects
8814 and/or depend on external state, they have to be properly sequenced.
8816 @cindex monadic values
8817 @cindex monadic functions
8818 This is where the @code{(guix monads)} module comes in. This module
8819 provides a framework for working with @dfn{monads}, and a particularly
8820 useful monad for our uses, the @dfn{store monad}. Monads are a
8821 construct that allows two things: associating ``context'' with values
8822 (in our case, the context is the store), and building sequences of
8823 computations (here computations include accesses to the store). Values
8824 in a monad---values that carry this additional context---are called
8825 @dfn{monadic values}; procedures that return such values are called
8826 @dfn{monadic procedures}.
8828 Consider this ``normal'' procedure:
8831 (define (sh-symlink store)
8832 ;; Return a derivation that symlinks the 'bash' executable.
8833 (let* ((drv (package-derivation store bash))
8834 (out (derivation->output-path drv))
8835 (sh (string-append out "/bin/bash")))
8836 (build-expression->derivation store "sh"
8837 `(symlink ,sh %output))))
8840 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
8841 as a monadic function:
8844 (define (sh-symlink)
8845 ;; Same, but return a monadic value.
8846 (mlet %store-monad ((drv (package->derivation bash)))
8847 (gexp->derivation "sh"
8848 #~(symlink (string-append #$drv "/bin/bash")
8852 There are several things to note in the second version: the @code{store}
8853 parameter is now implicit and is ``threaded'' in the calls to the
8854 @code{package->derivation} and @code{gexp->derivation} monadic
8855 procedures, and the monadic value returned by @code{package->derivation}
8856 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
8858 As it turns out, the call to @code{package->derivation} can even be
8859 omitted since it will take place implicitly, as we will see later
8860 (@pxref{G-Expressions}):
8863 (define (sh-symlink)
8864 (gexp->derivation "sh"
8865 #~(symlink (string-append #$bash "/bin/bash")
8870 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
8871 @c for the funny quote.
8872 Calling the monadic @code{sh-symlink} has no effect. As someone once
8873 said, ``you exit a monad like you exit a building on fire: by running''.
8874 So, to exit the monad and get the desired effect, one must use
8875 @code{run-with-store}:
8878 (run-with-store (open-connection) (sh-symlink))
8879 @result{} /gnu/store/...-sh-symlink
8882 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
8883 new ``meta-commands'' to make it easier to deal with monadic procedures:
8884 @code{run-in-store}, and @code{enter-store-monad}. The former is used
8885 to ``run'' a single monadic value through the store:
8888 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
8889 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
8892 The latter enters a recursive REPL, where all the return values are
8893 automatically run through the store:
8896 scheme@@(guile-user)> ,enter-store-monad
8897 store-monad@@(guile-user) [1]> (package->derivation hello)
8898 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
8899 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
8900 $3 = "/gnu/store/@dots{}-foo"
8901 store-monad@@(guile-user) [1]> ,q
8902 scheme@@(guile-user)>
8906 Note that non-monadic values cannot be returned in the
8907 @code{store-monad} REPL.
8909 The main syntactic forms to deal with monads in general are provided by
8910 the @code{(guix monads)} module and are described below.
8912 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
8913 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
8917 @deffn {Scheme Syntax} return @var{val}
8918 Return a monadic value that encapsulates @var{val}.
8921 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
8922 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
8923 procedures @var{mproc}@dots{}@footnote{This operation is commonly
8924 referred to as ``bind'', but that name denotes an unrelated procedure in
8925 Guile. Thus we use this somewhat cryptic symbol inherited from the
8926 Haskell language.}. There can be one @var{mproc} or several of them, as
8931 (with-monad %state-monad
8933 (lambda (x) (return (+ 1 x)))
8934 (lambda (x) (return (* 2 x)))))
8938 @result{} some-state
8942 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
8944 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
8946 Bind the variables @var{var} to the monadic values @var{mval} in
8947 @var{body}, which is a sequence of expressions. As with the bind
8948 operator, this can be thought of as ``unpacking'' the raw, non-monadic
8949 value ``contained'' in @var{mval} and making @var{var} refer to that
8950 raw, non-monadic value within the scope of the @var{body}. The form
8951 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
8952 @var{val}, as per @code{let}. The binding operations occur in sequence
8953 from left to right. The last expression of @var{body} must be a monadic
8954 expression, and its result will become the result of the @code{mlet} or
8955 @code{mlet*} when run in the @var{monad}.
8957 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
8958 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
8961 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
8962 Bind @var{mexp} and the following monadic expressions in sequence,
8963 returning the result of the last expression. Every expression in the
8964 sequence must be a monadic expression.
8966 This is akin to @code{mlet}, except that the return values of the
8967 monadic expressions are ignored. In that sense, it is analogous to
8968 @code{begin}, but applied to monadic expressions.
8971 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
8972 When @var{condition} is true, evaluate the sequence of monadic
8973 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
8974 @var{condition} is false, return @code{*unspecified*} in the current
8975 monad. Every expression in the sequence must be a monadic expression.
8978 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
8979 When @var{condition} is false, evaluate the sequence of monadic
8980 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
8981 @var{condition} is true, return @code{*unspecified*} in the current
8982 monad. Every expression in the sequence must be a monadic expression.
8986 The @code{(guix monads)} module provides the @dfn{state monad}, which
8987 allows an additional value---the state---to be @emph{threaded} through
8988 monadic procedure calls.
8990 @defvr {Scheme Variable} %state-monad
8991 The state monad. Procedures in the state monad can access and change
8992 the state that is threaded.
8994 Consider the example below. The @code{square} procedure returns a value
8995 in the state monad. It returns the square of its argument, but also
8996 increments the current state value:
9000 (mlet %state-monad ((count (current-state)))
9001 (mbegin %state-monad
9002 (set-current-state (+ 1 count))
9005 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
9010 When ``run'' through @code{%state-monad}, we obtain that additional state
9011 value, which is the number of @code{square} calls.
9014 @deffn {Monadic Procedure} current-state
9015 Return the current state as a monadic value.
9018 @deffn {Monadic Procedure} set-current-state @var{value}
9019 Set the current state to @var{value} and return the previous state as a
9023 @deffn {Monadic Procedure} state-push @var{value}
9024 Push @var{value} to the current state, which is assumed to be a list,
9025 and return the previous state as a monadic value.
9028 @deffn {Monadic Procedure} state-pop
9029 Pop a value from the current state and return it as a monadic value.
9030 The state is assumed to be a list.
9033 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
9034 Run monadic value @var{mval} starting with @var{state} as the initial
9035 state. Return two values: the resulting value, and the resulting state.
9038 The main interface to the store monad, provided by the @code{(guix
9039 store)} module, is as follows.
9041 @defvr {Scheme Variable} %store-monad
9042 The store monad---an alias for @code{%state-monad}.
9044 Values in the store monad encapsulate accesses to the store. When its
9045 effect is needed, a value of the store monad must be ``evaluated'' by
9046 passing it to the @code{run-with-store} procedure (see below).
9049 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
9050 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
9051 open store connection.
9054 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
9055 Return as a monadic value the absolute file name in the store of the file
9056 containing @var{text}, a string. @var{references} is a list of store items that the
9057 resulting text file refers to; it defaults to the empty list.
9060 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
9061 Return as a monadic value the absolute file name in the store of the file
9062 containing @var{data}, a bytevector. @var{references} is a list of store
9063 items that the resulting binary file refers to; it defaults to the empty list.
9066 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
9067 [#:recursive? #t] [#:select? (const #t)]
9068 Return the name of @var{file} once interned in the store. Use
9069 @var{name} as its store name, or the basename of @var{file} if
9070 @var{name} is omitted.
9072 When @var{recursive?} is true, the contents of @var{file} are added
9073 recursively; if @var{file} designates a flat file and @var{recursive?}
9074 is true, its contents are added, and its permission bits are kept.
9076 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
9077 @var{stat})} for each directory entry, where @var{file} is the entry's
9078 absolute file name and @var{stat} is the result of @code{lstat}; exclude
9079 entries for which @var{select?} does not return true.
9081 The example below adds a file to the store, under two different names:
9084 (run-with-store (open-connection)
9085 (mlet %store-monad ((a (interned-file "README"))
9086 (b (interned-file "README" "LEGU-MIN")))
9087 (return (list a b))))
9089 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
9094 The @code{(guix packages)} module exports the following package-related
9097 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
9098 [#:system (%current-system)] [#:target #f] @
9101 value in the absolute file name of @var{file} within the @var{output}
9102 directory of @var{package}. When @var{file} is omitted, return the name
9103 of the @var{output} directory of @var{package}. When @var{target} is
9104 true, use it as a cross-compilation target triplet.
9106 Note that this procedure does @emph{not} build @var{package}. Thus, the
9107 result might or might not designate an existing file. We recommend not
9108 using this procedure unless you know what you are doing.
9111 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
9112 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
9113 @var{target} [@var{system}]
9114 Monadic version of @code{package-derivation} and
9115 @code{package-cross-derivation} (@pxref{Defining Packages}).
9120 @section G-Expressions
9122 @cindex G-expression
9123 @cindex build code quoting
9124 So we have ``derivations'', which represent a sequence of build actions
9125 to be performed to produce an item in the store (@pxref{Derivations}).
9126 These build actions are performed when asking the daemon to actually
9127 build the derivations; they are run by the daemon in a container
9128 (@pxref{Invoking guix-daemon}).
9130 @cindex code staging
9131 @cindex staging, of code
9132 @cindex strata of code
9133 It should come as no surprise that we like to write these build actions
9134 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
9135 code@footnote{The term @dfn{stratum} in this context was coined by
9136 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
9137 Kiselyov, who has written insightful
9138 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
9139 on this topic}, refers to this kind of code generation as
9140 @dfn{staging}.}: the ``host code''---code that defines packages, talks
9141 to the daemon, etc.---and the ``build code''---code that actually
9142 performs build actions, such as making directories, invoking
9143 @command{make}, and so on (@pxref{Build Phases}).
9145 To describe a derivation and its build actions, one typically needs to
9146 embed build code inside host code. It boils down to manipulating build
9147 code as data, and the homoiconicity of Scheme---code has a direct
9148 representation as data---comes in handy for that. But we need more than
9149 the normal @code{quasiquote} mechanism in Scheme to construct build
9152 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
9153 S-expressions adapted to build expressions. G-expressions, or
9154 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
9155 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
9156 @code{#$}, and @code{#$@@}), which are comparable to
9157 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
9158 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
9159 GNU Guile Reference Manual}). However, there are major differences:
9163 Gexps are meant to be written to a file and run or manipulated by other
9167 When a high-level object such as a package or derivation is unquoted
9168 inside a gexp, the result is as if its output file name had been
9172 Gexps carry information about the packages or derivations they refer to,
9173 and these dependencies are automatically added as inputs to the build
9174 processes that use them.
9177 @cindex lowering, of high-level objects in gexps
9178 This mechanism is not limited to package and derivation
9179 objects: @dfn{compilers} able to ``lower'' other high-level objects to
9180 derivations or files in the store can be defined,
9181 such that these objects can also be inserted
9182 into gexps. For example, a useful type of high-level objects that can be
9183 inserted in a gexp is ``file-like objects'', which make it easy to
9184 add files to the store and to refer to them in
9185 derivations and such (see @code{local-file} and @code{plain-file}
9188 To illustrate the idea, here is an example of a gexp:
9195 (symlink (string-append #$coreutils "/bin/ls")
9199 This gexp can be passed to @code{gexp->derivation}; we obtain a
9200 derivation that builds a directory containing exactly one symlink to
9201 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
9204 (gexp->derivation "the-thing" build-exp)
9207 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
9208 substituted to the reference to the @var{coreutils} package in the
9209 actual build code, and @var{coreutils} is automatically made an input to
9210 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
9211 output)}) is replaced by a string containing the directory name of the
9212 output of the derivation.
9214 @cindex cross compilation
9215 In a cross-compilation context, it is useful to distinguish between
9216 references to the @emph{native} build of a package---that can run on the
9217 host---versus references to cross builds of a package. To that end, the
9218 @code{#+} plays the same role as @code{#$}, but is a reference to a
9219 native package build:
9222 (gexp->derivation "vi"
9225 (mkdir (string-append #$output "/bin"))
9226 (system* (string-append #+coreutils "/bin/ln")
9228 (string-append #$emacs "/bin/emacs")
9229 (string-append #$output "/bin/vi")))
9230 #:target "aarch64-linux-gnu")
9234 In the example above, the native build of @var{coreutils} is used, so
9235 that @command{ln} can actually run on the host; but then the
9236 cross-compiled build of @var{emacs} is referenced.
9238 @cindex imported modules, for gexps
9239 @findex with-imported-modules
9240 Another gexp feature is @dfn{imported modules}: sometimes you want to be
9241 able to use certain Guile modules from the ``host environment'' in the
9242 gexp, so those modules should be imported in the ``build environment''.
9243 The @code{with-imported-modules} form allows you to express that:
9246 (let ((build (with-imported-modules '((guix build utils))
9248 (use-modules (guix build utils))
9249 (mkdir-p (string-append #$output "/bin"))))))
9250 (gexp->derivation "empty-dir"
9253 (display "success!\n")
9258 In this example, the @code{(guix build utils)} module is automatically
9259 pulled into the isolated build environment of our gexp, such that
9260 @code{(use-modules (guix build utils))} works as expected.
9262 @cindex module closure
9263 @findex source-module-closure
9264 Usually you want the @emph{closure} of the module to be imported---i.e.,
9265 the module itself and all the modules it depends on---rather than just
9266 the module; failing to do that, attempts to use the module will fail
9267 because of missing dependent modules. The @code{source-module-closure}
9268 procedure computes the closure of a module by looking at its source file
9269 headers, which comes in handy in this case:
9272 (use-modules (guix modules)) ;for 'source-module-closure'
9274 (with-imported-modules (source-module-closure
9275 '((guix build utils)
9277 (gexp->derivation "something-with-vms"
9279 (use-modules (guix build utils)
9284 @cindex extensions, for gexps
9285 @findex with-extensions
9286 In the same vein, sometimes you want to import not just pure-Scheme
9287 modules, but also ``extensions'' such as Guile bindings to C libraries
9288 or other ``full-blown'' packages. Say you need the @code{guile-json}
9289 package available on the build side, here's how you would do it:
9292 (use-modules (gnu packages guile)) ;for 'guile-json'
9294 (with-extensions (list guile-json)
9295 (gexp->derivation "something-with-json"
9297 (use-modules (json))
9301 The syntactic form to construct gexps is summarized below.
9303 @deffn {Scheme Syntax} #~@var{exp}
9304 @deffnx {Scheme Syntax} (gexp @var{exp})
9305 Return a G-expression containing @var{exp}. @var{exp} may contain one
9306 or more of the following forms:
9310 @itemx (ungexp @var{obj})
9311 Introduce a reference to @var{obj}. @var{obj} may have one of the
9312 supported types, for example a package or a
9313 derivation, in which case the @code{ungexp} form is replaced by its
9314 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
9316 If @var{obj} is a list, it is traversed and references to supported
9317 objects are substituted similarly.
9319 If @var{obj} is another gexp, its contents are inserted and its
9320 dependencies are added to those of the containing gexp.
9322 If @var{obj} is another kind of object, it is inserted as is.
9324 @item #$@var{obj}:@var{output}
9325 @itemx (ungexp @var{obj} @var{output})
9326 This is like the form above, but referring explicitly to the
9327 @var{output} of @var{obj}---this is useful when @var{obj} produces
9328 multiple outputs (@pxref{Packages with Multiple Outputs}).
9331 @itemx #+@var{obj}:output
9332 @itemx (ungexp-native @var{obj})
9333 @itemx (ungexp-native @var{obj} @var{output})
9334 Same as @code{ungexp}, but produces a reference to the @emph{native}
9335 build of @var{obj} when used in a cross compilation context.
9337 @item #$output[:@var{output}]
9338 @itemx (ungexp output [@var{output}])
9339 Insert a reference to derivation output @var{output}, or to the main
9340 output when @var{output} is omitted.
9342 This only makes sense for gexps passed to @code{gexp->derivation}.
9345 @itemx (ungexp-splicing @var{lst})
9346 Like the above, but splices the contents of @var{lst} inside the
9350 @itemx (ungexp-native-splicing @var{lst})
9351 Like the above, but refers to native builds of the objects listed in
9356 G-expressions created by @code{gexp} or @code{#~} are run-time objects
9357 of the @code{gexp?} type (see below).
9360 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
9361 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
9362 in their execution environment.
9364 Each item in @var{modules} can be the name of a module, such as
9365 @code{(guix build utils)}, or it can be a module name, followed by an
9366 arrow, followed by a file-like object:
9369 `((guix build utils)
9371 ((guix config) => ,(scheme-file "config.scm"
9372 #~(define-module @dots{}))))
9376 In the example above, the first two modules are taken from the search
9377 path, and the last one is created from the given file-like object.
9379 This form has @emph{lexical} scope: it has an effect on the gexps
9380 directly defined in @var{body}@dots{}, but not on those defined, say, in
9381 procedures called from @var{body}@dots{}.
9384 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
9385 Mark the gexps defined in @var{body}@dots{} as requiring
9386 @var{extensions} in their build and execution environment.
9387 @var{extensions} is typically a list of package objects such as those
9388 defined in the @code{(gnu packages guile)} module.
9390 Concretely, the packages listed in @var{extensions} are added to the
9391 load path while compiling imported modules in @var{body}@dots{}; they
9392 are also added to the load path of the gexp returned by
9396 @deffn {Scheme Procedure} gexp? @var{obj}
9397 Return @code{#t} if @var{obj} is a G-expression.
9400 G-expressions are meant to be written to disk, either as code building
9401 some derivation, or as plain files in the store. The monadic procedures
9402 below allow you to do that (@pxref{The Store Monad}, for more
9403 information about monads).
9405 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
9406 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
9407 [#:hash #f] [#:hash-algo #f] @
9408 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
9409 [#:module-path @code{%load-path}] @
9410 [#:effective-version "2.2"] @
9411 [#:references-graphs #f] [#:allowed-references #f] @
9412 [#:disallowed-references #f] @
9413 [#:leaked-env-vars #f] @
9414 [#:script-name (string-append @var{name} "-builder")] @
9415 [#:deprecation-warnings #f] @
9416 [#:local-build? #f] [#:substitutable? #t] @
9417 [#:properties '()] [#:guile-for-build #f]
9418 Return a derivation @var{name} that runs @var{exp} (a gexp) with
9419 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
9420 stored in a file called @var{script-name}. When @var{target} is true,
9421 it is used as the cross-compilation target triplet for packages referred
9424 @var{modules} is deprecated in favor of @code{with-imported-modules}.
9426 make @var{modules} available in the evaluation context of @var{exp};
9427 @var{modules} is a list of names of Guile modules searched in
9428 @var{module-path} to be copied in the store, compiled, and made available in
9429 the load path during the execution of @var{exp}---e.g., @code{((guix
9430 build utils) (guix build gnu-build-system))}.
9432 @var{effective-version} determines the string to use when adding extensions of
9433 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
9435 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
9438 When @var{references-graphs} is true, it must be a list of tuples of one of the
9442 (@var{file-name} @var{package})
9443 (@var{file-name} @var{package} @var{output})
9444 (@var{file-name} @var{derivation})
9445 (@var{file-name} @var{derivation} @var{output})
9446 (@var{file-name} @var{store-item})
9449 The right-hand-side of each element of @var{references-graphs} is automatically made
9450 an input of the build process of @var{exp}. In the build environment, each
9451 @var{file-name} contains the reference graph of the corresponding item, in a simple
9454 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
9455 In the latter case, the list denotes store items that the result is allowed to
9456 refer to. Any reference to another store item will lead to a build error.
9457 Similarly for @var{disallowed-references}, which can list items that must not be
9458 referenced by the outputs.
9460 @var{deprecation-warnings} determines whether to show deprecation warnings while
9461 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
9463 The other arguments are as for @code{derivation} (@pxref{Derivations}).
9466 @cindex file-like objects
9467 The @code{local-file}, @code{plain-file}, @code{computed-file},
9468 @code{program-file}, and @code{scheme-file} procedures below return
9469 @dfn{file-like objects}. That is, when unquoted in a G-expression,
9470 these objects lead to a file in the store. Consider this G-expression:
9473 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
9474 #$(local-file "/tmp/my-nscd.conf"))
9477 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
9478 to the store. Once expanded, for instance @i{via}
9479 @code{gexp->derivation}, the G-expression refers to that copy under
9480 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
9481 does not have any effect on what the G-expression does.
9482 @code{plain-file} can be used similarly; it differs in that the file
9483 content is directly passed as a string.
9485 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
9486 [#:recursive? #f] [#:select? (const #t)]
9487 Return an object representing local file @var{file} to add to the store;
9488 this object can be used in a gexp. If @var{file} is a literal string
9489 denoting a relative file name, it is looked up relative to the source
9490 file where it appears; if @var{file} is not a literal string, it is
9491 looked up relative to the current working directory at run time.
9492 @var{file} will be added to the store under @var{name}--by default the
9493 base name of @var{file}.
9495 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
9496 designates a flat file and @var{recursive?} is true, its contents are added, and its
9497 permission bits are kept.
9499 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
9500 @var{stat})} for each directory entry, where @var{file} is the entry's
9501 absolute file name and @var{stat} is the result of @code{lstat}; exclude
9502 entries for which @var{select?} does not return true.
9504 This is the declarative counterpart of the @code{interned-file} monadic
9505 procedure (@pxref{The Store Monad, @code{interned-file}}).
9508 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
9509 Return an object representing a text file called @var{name} with the given
9510 @var{content} (a string or a bytevector) to be added to the store.
9512 This is the declarative counterpart of @code{text-file}.
9515 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
9518 Return an object representing the store item @var{name}, a file or
9519 directory computed by @var{gexp}. When @var{local-build?} is true (the
9520 default), the derivation is built locally. @var{options} is a list of
9521 additional arguments to pass to @code{gexp->derivation}.
9523 This is the declarative counterpart of @code{gexp->derivation}.
9526 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
9527 [#:guile (default-guile)] [#:module-path %load-path] @
9528 [#:system (%current-system)] [#:target #f]
9529 Return an executable script @var{name} that runs @var{exp} using
9530 @var{guile}, with @var{exp}'s imported modules in its search path.
9531 Look up @var{exp}'s modules in @var{module-path}.
9533 The example below builds a script that simply invokes the @command{ls}
9537 (use-modules (guix gexp) (gnu packages base))
9539 (gexp->script "list-files"
9540 #~(execl #$(file-append coreutils "/bin/ls")
9544 When ``running'' it through the store (@pxref{The Store Monad,
9545 @code{run-with-store}}), we obtain a derivation that produces an
9546 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
9549 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
9551 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
9555 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
9556 [#:guile #f] [#:module-path %load-path]
9557 Return an object representing the executable store item @var{name} that
9558 runs @var{gexp}. @var{guile} is the Guile package used to execute that
9559 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
9561 This is the declarative counterpart of @code{gexp->script}.
9564 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
9565 [#:set-load-path? #t] [#:module-path %load-path] @
9567 [#:guile (default-guile)]
9568 Return a derivation that builds a file @var{name} containing @var{exp}.
9569 When @var{splice?} is true, @var{exp} is considered to be a list of
9570 expressions that will be spliced in the resulting file.
9572 When @var{set-load-path?} is true, emit code in the resulting file to
9573 set @code{%load-path} and @code{%load-compiled-path} to honor
9574 @var{exp}'s imported modules. Look up @var{exp}'s modules in
9577 The resulting file holds references to all the dependencies of @var{exp}
9578 or a subset thereof.
9581 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} @
9582 [#:splice? #f] [#:set-load-path? #t]
9583 Return an object representing the Scheme file @var{name} that contains
9586 This is the declarative counterpart of @code{gexp->file}.
9589 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
9590 Return as a monadic value a derivation that builds a text file
9591 containing all of @var{text}. @var{text} may list, in addition to
9592 strings, objects of any type that can be used in a gexp: packages,
9593 derivations, local file objects, etc. The resulting store file holds
9594 references to all these.
9596 This variant should be preferred over @code{text-file} anytime the file
9597 to create will reference items from the store. This is typically the
9598 case when building a configuration file that embeds store file names,
9602 (define (profile.sh)
9603 ;; Return the name of a shell script in the store that
9604 ;; initializes the 'PATH' environment variable.
9605 (text-file* "profile.sh"
9606 "export PATH=" coreutils "/bin:"
9607 grep "/bin:" sed "/bin\n"))
9610 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
9611 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
9612 preventing them from being garbage-collected during its lifetime.
9615 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
9616 Return an object representing store file @var{name} containing
9617 @var{text}. @var{text} is a sequence of strings and file-like objects,
9621 (mixed-text-file "profile"
9622 "export PATH=" coreutils "/bin:" grep "/bin")
9625 This is the declarative counterpart of @code{text-file*}.
9628 @deffn {Scheme Procedure} file-union @var{name} @var{files}
9629 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
9630 Each item in @var{files} must be a two-element list where the first element is the
9631 file name to use in the new directory, and the second element is a gexp
9632 denoting the target file. Here's an example:
9636 `(("hosts" ,(plain-file "hosts"
9637 "127.0.0.1 localhost"))
9638 ("bashrc" ,(plain-file "bashrc"
9639 "alias ls='ls --color=auto'"))))
9642 This yields an @code{etc} directory containing these two files.
9645 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
9646 Return a directory that is the union of @var{things}, where @var{things} is a list of
9647 file-like objects denoting directories. For example:
9650 (directory-union "guile+emacs" (list guile emacs))
9653 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
9656 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
9657 Return a file-like object that expands to the concatenation of @var{obj}
9658 and @var{suffix}, where @var{obj} is a lowerable object and each
9659 @var{suffix} is a string.
9661 As an example, consider this gexp:
9664 (gexp->script "run-uname"
9665 #~(system* #$(file-append coreutils
9669 The same effect could be achieved with:
9672 (gexp->script "run-uname"
9673 #~(system* (string-append #$coreutils
9677 There is one difference though: in the @code{file-append} case, the
9678 resulting script contains the absolute file name as a string, whereas in
9679 the second case, the resulting script contains a @code{(string-append
9680 @dots{})} expression to construct the file name @emph{at run time}.
9683 @deffn {Scheme Syntax} let-system @var{system} @var{body}@dots{}
9684 @deffnx {Scheme Syntax} let-system (@var{system} @var{target}) @var{body}@dots{}
9685 Bind @var{system} to the currently targeted system---e.g.,
9686 @code{"x86_64-linux"}---within @var{body}.
9688 In the second case, additionally bind @var{target} to the current
9689 cross-compilation target---a GNU triplet such as
9690 @code{"arm-linux-gnueabihf"}---or @code{#f} if we are not
9693 @code{let-system} is useful in the occasional case where the object
9694 spliced into the gexp depends on the target system, as in this example:
9698 #+(let-system system
9699 (cond ((string-prefix? "armhf-" system)
9700 (file-append qemu "/bin/qemu-system-arm"))
9701 ((string-prefix? "x86_64-" system)
9702 (file-append qemu "/bin/qemu-system-x86_64"))
9705 "-net" "user" #$image)
9709 @deffn {Scheme Syntax} with-parameters ((@var{parameter} @var{value}) @dots{}) @var{exp}
9710 This macro is similar to the @code{parameterize} form for
9711 dynamically-bound @dfn{parameters} (@pxref{Parameters,,, guile, GNU
9712 Guile Reference Manual}). The key difference is that it takes effect
9713 when the file-like object returned by @var{exp} is lowered to a
9714 derivation or store item.
9716 A typical use of @code{with-parameters} is to force the system in effect
9720 (with-parameters ((%current-system "i686-linux"))
9724 The example above returns an object that corresponds to the i686 build
9725 of Coreutils, regardless of the current value of @code{%current-system}.
9729 Of course, in addition to gexps embedded in ``host'' code, there are
9730 also modules containing build tools. To make it clear that they are
9731 meant to be used in the build stratum, these modules are kept in the
9732 @code{(guix build @dots{})} name space.
9734 @cindex lowering, of high-level objects in gexps
9735 Internally, high-level objects are @dfn{lowered}, using their compiler,
9736 to either derivations or store items. For instance, lowering a package
9737 yields a derivation, and lowering a @code{plain-file} yields a store
9738 item. This is achieved using the @code{lower-object} monadic procedure.
9740 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
9742 Return as a value in @code{%store-monad} the derivation or store item
9743 corresponding to @var{obj} for @var{system}, cross-compiling for
9744 @var{target} if @var{target} is true. @var{obj} must be an object that
9745 has an associated gexp compiler, such as a @code{<package>}.
9748 @node Invoking guix repl
9749 @section Invoking @command{guix repl}
9751 @cindex REPL, read-eval-print loop, script
9752 The @command{guix repl} command makes it easier to program Guix in Guile
9753 by launching a Guile @dfn{read-eval-print loop} (REPL) for interactive
9754 programming (@pxref{Using Guile Interactively,,, guile,
9755 GNU Guile Reference Manual}), or by running Guile scripts
9756 (@pxref{Running Guile Scripts,,, guile,
9757 GNU Guile Reference Manual}).
9758 Compared to just launching the @command{guile}
9759 command, @command{guix repl} guarantees that all the Guix modules and all its
9760 dependencies are available in the search path.
9762 The general syntax is:
9765 guix repl @var{options} [@var{file} @var{args}]
9768 When a @var{file} argument is provided, @var{file} is
9769 executed as a Guile scripts:
9772 guix repl my-script.scm
9775 To pass arguments to the script, use @code{--} to prevent them from
9776 being interpreted as arguments to @command{guix repl} itself:
9779 guix repl -- my-script.scm --input=foo.txt
9782 To make a script executable directly from the shell, using the guix
9783 executable that is on the user's search path, add the following two
9784 lines at the top of the script:
9787 @code{#!/usr/bin/env -S guix repl --}
9791 Without a file name argument, a Guile REPL is started:
9795 scheme@@(guile-user)> ,use (gnu packages base)
9796 scheme@@(guile-user)> coreutils
9797 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
9801 In addition, @command{guix repl} implements a simple machine-readable REPL
9802 protocol for use by @code{(guix inferior)}, a facility to interact with
9803 @dfn{inferiors}, separate processes running a potentially different revision
9806 The available options are as follows:
9809 @item --type=@var{type}
9810 @itemx -t @var{type}
9811 Start a REPL of the given @var{TYPE}, which can be one of the following:
9815 This is default, and it spawns a standard full-featured Guile REPL.
9817 Spawn a REPL that uses the machine-readable protocol. This is the protocol
9818 that the @code{(guix inferior)} module speaks.
9821 @item --listen=@var{endpoint}
9822 By default, @command{guix repl} reads from standard input and writes to
9823 standard output. When this option is passed, it will instead listen for
9824 connections on @var{endpoint}. Here are examples of valid options:
9827 @item --listen=tcp:37146
9828 Accept connections on localhost on port 37146.
9830 @item --listen=unix:/tmp/socket
9831 Accept connections on the Unix-domain socket @file{/tmp/socket}.
9834 @item --load-path=@var{directory}
9835 @itemx -L @var{directory}
9836 Add @var{directory} to the front of the package module search path
9837 (@pxref{Package Modules}).
9839 This allows users to define their own packages and make them visible to
9843 Inhibit loading of the @file{~/.guile} file. By default, that
9844 configuration file is loaded when spawning a @code{guile} REPL.
9847 @c *********************************************************************
9851 This section describes Guix command-line utilities. Some of them are
9852 primarily targeted at developers and users who write new package
9853 definitions, while others are more generally useful. They complement
9854 the Scheme programming interface of Guix in a convenient way.
9857 * Invoking guix build:: Building packages from the command line.
9858 * Invoking guix edit:: Editing package definitions.
9859 * Invoking guix download:: Downloading a file and printing its hash.
9860 * Invoking guix hash:: Computing the cryptographic hash of a file.
9861 * Invoking guix import:: Importing package definitions.
9862 * Invoking guix refresh:: Updating package definitions.
9863 * Invoking guix lint:: Finding errors in package definitions.
9864 * Invoking guix size:: Profiling disk usage.
9865 * Invoking guix graph:: Visualizing the graph of packages.
9866 * Invoking guix publish:: Sharing substitutes.
9867 * Invoking guix challenge:: Challenging substitute servers.
9868 * Invoking guix copy:: Copying to and from a remote store.
9869 * Invoking guix container:: Process isolation.
9870 * Invoking guix weather:: Assessing substitute availability.
9871 * Invoking guix processes:: Listing client processes.
9874 @node Invoking guix build
9875 @section Invoking @command{guix build}
9877 @cindex package building
9878 @cindex @command{guix build}
9879 The @command{guix build} command builds packages or derivations and
9880 their dependencies, and prints the resulting store paths. Note that it
9881 does not modify the user's profile---this is the job of the
9882 @command{guix package} command (@pxref{Invoking guix package}). Thus,
9883 it is mainly useful for distribution developers.
9885 The general syntax is:
9888 guix build @var{options} @var{package-or-derivation}@dots{}
9891 As an example, the following command builds the latest versions of Emacs
9892 and of Guile, displays their build logs, and finally displays the
9893 resulting directories:
9896 guix build emacs guile
9899 Similarly, the following command builds all the available packages:
9902 guix build --quiet --keep-going \
9903 `guix package -A | cut -f1,2 --output-delimiter=@@`
9906 @var{package-or-derivation} may be either the name of a package found in
9907 the software distribution such as @code{coreutils} or
9908 @code{coreutils@@8.20}, or a derivation such as
9909 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
9910 package with the corresponding name (and optionally version) is searched
9911 for among the GNU distribution modules (@pxref{Package Modules}).
9913 Alternatively, the @option{--expression} option may be used to specify a
9914 Scheme expression that evaluates to a package; this is useful when
9915 disambiguating among several same-named packages or package variants is
9918 There may be zero or more @var{options}. The available options are
9919 described in the subsections below.
9922 * Common Build Options:: Build options for most commands.
9923 * Package Transformation Options:: Creating variants of packages.
9924 * Additional Build Options:: Options specific to 'guix build'.
9925 * Debugging Build Failures:: Real life packaging experience.
9928 @node Common Build Options
9929 @subsection Common Build Options
9931 A number of options that control the build process are common to
9932 @command{guix build} and other commands that can spawn builds, such as
9933 @command{guix package} or @command{guix archive}. These are the
9938 @item --load-path=@var{directory}
9939 @itemx -L @var{directory}
9940 Add @var{directory} to the front of the package module search path
9941 (@pxref{Package Modules}).
9943 This allows users to define their own packages and make them visible to
9944 the command-line tools.
9948 Keep the build tree of failed builds. Thus, if a build fails, its build
9949 tree is kept under @file{/tmp}, in a directory whose name is shown at
9950 the end of the build log. This is useful when debugging build issues.
9951 @xref{Debugging Build Failures}, for tips and tricks on how to debug
9954 This option implies @option{--no-offload}, and it has no effect when
9955 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
9956 Store, the @env{GUIX_DAEMON_SOCKET} variable}).
9960 Keep going when some of the derivations fail to build; return only once
9961 all the builds have either completed or failed.
9963 The default behavior is to stop as soon as one of the specified
9964 derivations has failed.
9968 Do not build the derivations.
9970 @anchor{fallback-option}
9972 When substituting a pre-built binary fails, fall back to building
9973 packages locally (@pxref{Substitution Failure}).
9975 @item --substitute-urls=@var{urls}
9976 @anchor{client-substitute-urls}
9977 Consider @var{urls} the whitespace-separated list of substitute source
9978 URLs, overriding the default list of URLs of @command{guix-daemon}
9979 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
9981 This means that substitutes may be downloaded from @var{urls}, provided
9982 they are signed by a key authorized by the system administrator
9983 (@pxref{Substitutes}).
9985 When @var{urls} is the empty string, substitutes are effectively
9988 @item --no-substitutes
9989 Do not use substitutes for build products. That is, always build things
9990 locally instead of allowing downloads of pre-built binaries
9991 (@pxref{Substitutes}).
9994 Do not ``graft'' packages. In practice, this means that package updates
9995 available as grafts are not applied. @xref{Security Updates}, for more
9996 information on grafts.
9998 @item --rounds=@var{n}
9999 Build each derivation @var{n} times in a row, and raise an error if
10000 consecutive build results are not bit-for-bit identical.
10002 This is a useful way to detect non-deterministic builds processes.
10003 Non-deterministic build processes are a problem because they make it
10004 practically impossible for users to @emph{verify} whether third-party
10005 binaries are genuine. @xref{Invoking guix challenge}, for more.
10007 When used in conjunction with @option{--keep-failed}, the differing
10008 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
10009 This makes it easy to look for differences between the two results.
10012 Do not use offload builds to other machines (@pxref{Daemon Offload
10013 Setup}). That is, always build things locally instead of offloading
10014 builds to remote machines.
10016 @item --max-silent-time=@var{seconds}
10017 When the build or substitution process remains silent 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{--max-silent-time}}).
10023 @item --timeout=@var{seconds}
10024 Likewise, when the build or substitution process lasts for more than
10025 @var{seconds}, terminate it and report a build failure.
10027 By default, the daemon's setting is honored (@pxref{Invoking
10028 guix-daemon, @option{--timeout}}).
10030 @c Note: This option is actually not part of %standard-build-options but
10031 @c most programs honor it.
10032 @cindex verbosity, of the command-line tools
10033 @cindex build logs, verbosity
10034 @item -v @var{level}
10035 @itemx --verbosity=@var{level}
10036 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
10037 output is produced, 1 is for quiet output, and 2 shows all the build log
10038 output on standard error.
10040 @item --cores=@var{n}
10042 Allow the use of up to @var{n} CPU cores for the build. The special
10043 value @code{0} means to use as many CPU cores as available.
10045 @item --max-jobs=@var{n}
10047 Allow at most @var{n} build jobs in parallel. @xref{Invoking
10048 guix-daemon, @option{--max-jobs}}, for details about this option and the
10049 equivalent @command{guix-daemon} option.
10051 @item --debug=@var{level}
10052 Produce debugging output coming from the build daemon. @var{level} must be an
10053 integer between 0 and 5; higher means more verbose output. Setting a level of
10054 4 or more may be helpful when debugging setup issues with the build daemon.
10058 Behind the scenes, @command{guix build} is essentially an interface to
10059 the @code{package-derivation} procedure of the @code{(guix packages)}
10060 module, and to the @code{build-derivations} procedure of the @code{(guix
10061 derivations)} module.
10063 In addition to options explicitly passed on the command line,
10064 @command{guix build} and other @command{guix} commands that support
10065 building honor the @env{GUIX_BUILD_OPTIONS} environment variable.
10067 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
10068 Users can define this variable to a list of command line options that
10069 will automatically be used by @command{guix build} and other
10070 @command{guix} commands that can perform builds, as in the example
10074 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
10077 These options are parsed independently, and the result is appended to
10078 the parsed command-line options.
10082 @node Package Transformation Options
10083 @subsection Package Transformation Options
10085 @cindex package variants
10086 Another set of command-line options supported by @command{guix build}
10087 and also @command{guix package} are @dfn{package transformation
10088 options}. These are options that make it possible to define @dfn{package
10089 variants}---for instance, packages built from different source code.
10090 This is a convenient way to create customized packages on the fly
10091 without having to type in the definitions of package variants
10092 (@pxref{Defining Packages}).
10094 Package transformation options are preserved across upgrades:
10095 @command{guix upgrade} attempts to apply transformation options
10096 initially used when creating the profile to the upgraded packages.
10098 The available options are listed below. Most commands support them and
10099 also support a @option{--help-transform} option that lists all the
10100 available options and a synopsis (these options are not shown in the
10101 @option{--help} output for brevity).
10105 @item --with-source=@var{source}
10106 @itemx --with-source=@var{package}=@var{source}
10107 @itemx --with-source=@var{package}@@@var{version}=@var{source}
10108 Use @var{source} as the source of @var{package}, and @var{version} as
10109 its version number.
10110 @var{source} must be a file name or a URL, as for @command{guix
10111 download} (@pxref{Invoking guix download}).
10113 When @var{package} is omitted,
10114 it is taken to be the package name specified on the
10115 command line that matches the base of @var{source}---e.g.,
10116 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
10117 package is @code{guile}.
10119 Likewise, when @var{version} is omitted, the version string is inferred from
10120 @var{source}; in the previous example, it is @code{2.0.10}.
10122 This option allows users to try out versions of packages other than the
10123 one provided by the distribution. The example below downloads
10124 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
10125 the @code{ed} package:
10128 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
10131 As a developer, @option{--with-source} makes it easy to test release
10135 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
10138 @dots{} or to build from a checkout in a pristine environment:
10141 $ git clone git://git.sv.gnu.org/guix.git
10142 $ guix build guix --with-source=guix@@1.0=./guix
10145 @item --with-input=@var{package}=@var{replacement}
10146 Replace dependency on @var{package} by a dependency on
10147 @var{replacement}. @var{package} must be a package name, and
10148 @var{replacement} must be a package specification such as @code{guile}
10149 or @code{guile@@1.8}.
10151 For instance, the following command builds Guix, but replaces its
10152 dependency on the current stable version of Guile with a dependency on
10153 the legacy version of Guile, @code{guile@@2.0}:
10156 guix build --with-input=guile=guile@@2.0 guix
10159 This is a recursive, deep replacement. So in this example, both
10160 @code{guix} and its dependency @code{guile-json} (which also depends on
10161 @code{guile}) get rebuilt against @code{guile@@2.0}.
10163 This is implemented using the @code{package-input-rewriting} Scheme
10164 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
10166 @item --with-graft=@var{package}=@var{replacement}
10167 This is similar to @option{--with-input} but with an important difference:
10168 instead of rebuilding the whole dependency chain, @var{replacement} is
10169 built and then @dfn{grafted} onto the binaries that were initially
10170 referring to @var{package}. @xref{Security Updates}, for more
10171 information on grafts.
10173 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
10174 and all its dependencies, replacing references to the version of GnuTLS
10175 they currently refer to:
10178 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
10181 This has the advantage of being much faster than rebuilding everything.
10182 But there is a caveat: it works if and only if @var{package} and
10183 @var{replacement} are strictly compatible---for example, if they provide
10184 a library, the application binary interface (ABI) of those libraries
10185 must be compatible. If @var{replacement} is somehow incompatible with
10186 @var{package}, then the resulting package may be unusable. Use with
10189 @cindex debugging info, rebuilding
10190 @item --with-debug-info=@var{package}
10191 Build @var{package} in a way that preserves its debugging info and graft
10192 it onto packages that depend on it. This is useful if @var{package}
10193 does not already provide debugging info as a @code{debug} output
10194 (@pxref{Installing Debugging Files}).
10196 For example, suppose you're experiencing a crash in Inkscape and would
10197 like to see what's up in GLib, a library deep down in Inkscape's
10198 dependency graph. GLib lacks a @code{debug} output, so debugging is
10199 tough. Fortunately, you rebuild GLib with debugging info and tack it on
10203 guix install inkscape --with-debug-info=glib
10206 Only GLib needs to be recompiled so this takes a reasonable amount of
10207 time. @xref{Installing Debugging Files}, for more info.
10210 Under the hood, this option works by passing the @samp{#:strip-binaries?
10211 #f} to the build system of the package of interest (@pxref{Build
10212 Systems}). Most build systems support that option but some do not. In
10213 that case, an error is raised.
10215 Likewise, if a C/C++ package is built without @code{-g} (which is rarely
10216 the case), debugging info will remain unavailable even when
10217 @code{#:strip-binaries?} is false.
10220 @cindex tool chain, changing the build tool chain of a package
10221 @item --with-c-toolchain=@var{package}=@var{toolchain}
10222 This option changes the compilation of @var{package} and everything that
10223 depends on it so that they get built with @var{toolchain} instead of the
10224 default GNU tool chain for C/C++.
10226 Consider this example:
10229 guix build octave-cli \
10230 --with-c-toolchain=fftw=gcc-toolchain@@10 \
10231 --with-c-toolchain=fftwf=gcc-toolchain@@10
10234 The command above builds a variant of the @code{fftw} and @code{fftwf}
10235 packages using version 10 of @code{gcc-toolchain} instead of the default
10236 tool chain, and then builds a variant of the GNU@tie{}Octave
10237 command-line interface using them. GNU@tie{}Octave itself is also built
10238 with @code{gcc-toolchain@@10}.
10240 This other example builds the Hardware Locality (@code{hwloc}) library
10241 and its dependents up to @code{intel-mpi-benchmarks} with the Clang C
10245 guix build --with-c-toolchain=hwloc=clang-toolchain \
10246 intel-mpi-benchmarks
10250 There can be application binary interface (ABI) incompatibilities among
10251 tool chains. This is particularly true of the C++ standard library and
10252 run-time support libraries such as that of OpenMP. By rebuilding all
10253 dependents with the same tool chain, @option{--with-c-toolchain} minimizes
10254 the risks of incompatibility but cannot entirely eliminate them. Choose
10255 @var{package} wisely.
10258 @item --with-git-url=@var{package}=@var{url}
10259 @cindex Git, using the latest commit
10260 @cindex latest commit, building
10261 Build @var{package} from the latest commit of the @code{master} branch of the
10262 Git repository at @var{url}. Git sub-modules of the repository are fetched,
10265 For example, the following command builds the NumPy Python library against the
10266 latest commit of the master branch of Python itself:
10269 guix build python-numpy \
10270 --with-git-url=python=https://github.com/python/cpython
10273 This option can also be combined with @option{--with-branch} or
10274 @option{--with-commit} (see below).
10276 @cindex continuous integration
10277 Obviously, since it uses the latest commit of the given branch, the result of
10278 such a command varies over time. Nevertheless it is a convenient way to
10279 rebuild entire software stacks against the latest commit of one or more
10280 packages. This is particularly useful in the context of continuous
10283 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
10284 consecutive accesses to the same repository. You may want to clean it up once
10285 in a while to save disk space.
10287 @item --with-branch=@var{package}=@var{branch}
10288 Build @var{package} from the latest commit of @var{branch}. If the
10289 @code{source} field of @var{package} is an origin with the @code{git-fetch}
10290 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
10291 repository URL is taken from that @code{source}. Otherwise you have to use
10292 @option{--with-git-url} to specify the URL of the Git repository.
10294 For instance, the following command builds @code{guile-sqlite3} from the
10295 latest commit of its @code{master} branch, and then builds @code{guix} (which
10296 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
10297 specific @code{guile-sqlite3} build:
10300 guix build --with-branch=guile-sqlite3=master cuirass
10303 @item --with-commit=@var{package}=@var{commit}
10304 This is similar to @option{--with-branch}, except that it builds from
10305 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
10306 Git commit SHA1 identifier or a tag.
10308 @cindex test suite, skipping
10309 @item --without-tests=@var{package}
10310 Build @var{package} without running its tests. This can be useful in
10311 situations where you want to skip the lengthy test suite of a
10312 intermediate package, or if a package's test suite fails in a
10313 non-deterministic fashion. It should be used with care because running
10314 the test suite is a good way to ensure a package is working as intended.
10316 Turning off tests leads to a different store item. Consequently, when
10317 using this option, anything that depends on @var{package} must be
10318 rebuilt, as in this example:
10321 guix install --without-tests=python python-notebook
10324 The command above installs @code{python-notebook} on top of
10325 @code{python} built without running its test suite. To do so, it also
10326 rebuilds everything that depends on @code{python}, including
10327 @code{python-notebook} itself.
10329 Internally, @option{--without-tests} relies on changing the
10330 @code{#:tests?} option of a package's @code{check} phase (@pxref{Build
10331 Systems}). Note that some packages use a customized @code{check} phase
10332 that does not respect a @code{#:tests? #f} setting. Therefore,
10333 @option{--without-tests} has no effect on these packages.
10337 Wondering how to achieve the same effect using Scheme code, for example
10338 in your manifest, or how to write your own package transformation?
10339 @xref{Defining Package Variants}, for an overview of the programming
10340 interfaces available.
10342 @node Additional Build Options
10343 @subsection Additional Build Options
10345 The command-line options presented below are specific to @command{guix
10352 Build quietly, without displaying the build log; this is equivalent to
10353 @option{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
10354 (or similar) and can always be retrieved using the @option{--log-file} option.
10356 @item --file=@var{file}
10357 @itemx -f @var{file}
10358 Build the package, derivation, or other file-like object that the code within
10359 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
10361 As an example, @var{file} might contain a package definition like this
10362 (@pxref{Defining Packages}):
10365 @include package-hello.scm
10368 The @var{file} may also contain a JSON representation of one or more
10369 package definitions. Running @code{guix build -f} on @file{hello.json}
10370 with the following contents would result in building the packages
10371 @code{myhello} and @code{greeter}:
10374 @verbatiminclude package-hello.json
10377 @item --manifest=@var{manifest}
10378 @itemx -m @var{manifest}
10379 Build all packages listed in the given @var{manifest}
10380 (@pxref{profile-manifest, @option{--manifest}}).
10382 @item --expression=@var{expr}
10383 @itemx -e @var{expr}
10384 Build the package or derivation @var{expr} evaluates to.
10386 For example, @var{expr} may be @code{(@@ (gnu packages guile)
10387 guile-1.8)}, which unambiguously designates this specific variant of
10388 version 1.8 of Guile.
10390 Alternatively, @var{expr} may be a G-expression, in which case it is used
10391 as a build program passed to @code{gexp->derivation}
10392 (@pxref{G-Expressions}).
10394 Lastly, @var{expr} may refer to a zero-argument monadic procedure
10395 (@pxref{The Store Monad}). The procedure must return a derivation as a
10396 monadic value, which is then passed through @code{run-with-store}.
10400 Build the source derivations of the packages, rather than the packages
10403 For instance, @code{guix build -S gcc} returns something like
10404 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
10407 The returned source tarball is the result of applying any patches and
10408 code snippets specified in the package @code{origin} (@pxref{Defining
10411 Note that @command{guix build -S} compiles the sources only of the
10412 specified packages. They do not include the sources of statically
10413 linked dependencies and by themselves are insufficient for reproducing
10417 Fetch and return the source of @var{package-or-derivation} and all their
10418 dependencies, recursively. This is a handy way to obtain a local copy
10419 of all the source code needed to build @var{packages}, allowing you to
10420 eventually build them even without network access. It is an extension
10421 of the @option{--source} option and can accept one of the following
10422 optional argument values:
10426 This value causes the @option{--sources} option to behave in the same way
10427 as the @option{--source} option.
10430 Build the source derivations of all packages, including any source that
10431 might be listed as @code{inputs}. This is the default value.
10434 $ guix build --sources tzdata
10435 The following derivations will be built:
10436 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
10437 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
10441 Build the source derivations of all packages, as well of all transitive
10442 inputs to the packages. This can be used e.g.@: to
10443 prefetch package source for later offline building.
10446 $ guix build --sources=transitive tzdata
10447 The following derivations will be built:
10448 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
10449 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
10450 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
10451 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
10452 /gnu/store/@dots{}-make-4.1.tar.xz.drv
10453 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
10459 @item --system=@var{system}
10460 @itemx -s @var{system}
10461 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
10462 the system type of the build host. The @command{guix build} command allows
10463 you to repeat this option several times, in which case it builds for all the
10464 specified systems; other commands ignore extraneous @option{-s} options.
10467 The @option{--system} flag is for @emph{native} compilation and must not
10468 be confused with cross-compilation. See @option{--target} below for
10469 information on cross-compilation.
10472 An example use of this is on Linux-based systems, which can emulate
10473 different personalities. For instance, passing
10474 @option{--system=i686-linux} on an @code{x86_64-linux} system or
10475 @option{--system=armhf-linux} on an @code{aarch64-linux} system allows
10476 you to build packages in a complete 32-bit environment.
10479 Building for an @code{armhf-linux} system is unconditionally enabled on
10480 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
10481 allow for this functionality, notably the ThunderX.
10484 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
10485 is enabled (@pxref{Virtualization Services,
10486 @code{qemu-binfmt-service-type}}), you can build for any system for
10487 which a QEMU @code{binfmt_misc} handler is installed.
10489 Builds for a system other than that of the machine you are using can
10490 also be offloaded to a remote machine of the right architecture.
10491 @xref{Daemon Offload Setup}, for more information on offloading.
10493 @item --target=@var{triplet}
10494 @cindex cross-compilation
10495 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
10496 as @code{"aarch64-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
10497 configuration triplets,, autoconf, Autoconf}).
10499 @anchor{build-check}
10501 @cindex determinism, checking
10502 @cindex reproducibility, checking
10503 Rebuild @var{package-or-derivation}, which are already available in the
10504 store, and raise an error if the build results are not bit-for-bit
10507 This mechanism allows you to check whether previously installed
10508 substitutes are genuine (@pxref{Substitutes}), or whether the build result
10509 of a package is deterministic. @xref{Invoking guix challenge}, for more
10510 background information and tools.
10512 When used in conjunction with @option{--keep-failed}, the differing
10513 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
10514 This makes it easy to look for differences between the two results.
10517 @cindex repairing store items
10518 @cindex corruption, recovering from
10519 Attempt to repair the specified store items, if they are corrupt, by
10520 re-downloading or rebuilding them.
10522 This operation is not atomic and thus restricted to @code{root}.
10524 @item --derivations
10526 Return the derivation paths, not the output paths, of the given
10529 @item --root=@var{file}
10530 @itemx -r @var{file}
10531 @cindex GC roots, adding
10532 @cindex garbage collector roots, adding
10533 Make @var{file} a symlink to the result, and register it as a garbage
10536 Consequently, the results of this @command{guix build} invocation are
10537 protected from garbage collection until @var{file} is removed. When
10538 that option is omitted, build results are eligible for garbage
10539 collection as soon as the build completes. @xref{Invoking guix gc}, for
10543 @cindex build logs, access
10544 Return the build log file names or URLs for the given
10545 @var{package-or-derivation}, or raise an error if build logs are
10548 This works regardless of how packages or derivations are specified. For
10549 instance, the following invocations are equivalent:
10552 guix build --log-file `guix build -d guile`
10553 guix build --log-file `guix build guile`
10554 guix build --log-file guile
10555 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
10558 If a log is unavailable locally, and unless @option{--no-substitutes} is
10559 passed, the command looks for a corresponding log on one of the
10560 substitute servers (as specified with @option{--substitute-urls}).
10562 So for instance, imagine you want to see the build log of GDB on MIPS,
10563 but you are actually on an @code{x86_64} machine:
10566 $ guix build --log-file gdb -s aarch64-linux
10567 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
10570 You can freely access a huge library of build logs!
10573 @node Debugging Build Failures
10574 @subsection Debugging Build Failures
10576 @cindex build failures, debugging
10577 When defining a new package (@pxref{Defining Packages}), you will
10578 probably find yourself spending some time debugging and tweaking the
10579 build until it succeeds. To do that, you need to operate the build
10580 commands yourself in an environment as close as possible to the one the
10583 To that end, the first thing to do is to use the @option{--keep-failed}
10584 or @option{-K} option of @command{guix build}, which will keep the
10585 failed build tree in @file{/tmp} or whatever directory you specified as
10586 @env{TMPDIR} (@pxref{Invoking guix build, @option{--keep-failed}}).
10588 From there on, you can @command{cd} to the failed build tree and source
10589 the @file{environment-variables} file, which contains all the
10590 environment variable definitions that were in place when the build
10591 failed. So let's say you're debugging a build failure in package
10592 @code{foo}; a typical session would look like this:
10595 $ guix build foo -K
10596 @dots{} @i{build fails}
10597 $ cd /tmp/guix-build-foo.drv-0
10598 $ source ./environment-variables
10602 Now, you can invoke commands as if you were the daemon (almost) and
10603 troubleshoot your build process.
10605 Sometimes it happens that, for example, a package's tests pass when you
10606 run them manually but they fail when the daemon runs them. This can
10607 happen because the daemon runs builds in containers where, unlike in our
10608 environment above, network access is missing, @file{/bin/sh} does not
10609 exist, etc. (@pxref{Build Environment Setup}).
10611 In such cases, you may need to run inspect the build process from within
10612 a container similar to the one the build daemon creates:
10615 $ guix build -K foo
10617 $ cd /tmp/guix-build-foo.drv-0
10618 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
10619 [env]# source ./environment-variables
10623 Here, @command{guix environment -C} creates a container and spawns a new
10624 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
10625 strace gdb} part adds the @command{strace} and @command{gdb} commands to
10626 the container, which you may find handy while debugging. The
10627 @option{--no-grafts} option makes sure we get the exact same
10628 environment, with ungrafted packages (@pxref{Security Updates}, for more
10631 To get closer to a container like that used by the build daemon, we can
10632 remove @file{/bin/sh}:
10638 (Don't worry, this is harmless: this is all happening in the throw-away
10639 container created by @command{guix environment}.)
10641 The @command{strace} command is probably not in the search path, but we
10645 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
10648 In this way, not only you will have reproduced the environment variables
10649 the daemon uses, you will also be running the build process in a container
10650 similar to the one the daemon uses.
10653 @node Invoking guix edit
10654 @section Invoking @command{guix edit}
10656 @cindex @command{guix edit}
10657 @cindex package definition, editing
10658 So many packages, so many source files! The @command{guix edit} command
10659 facilitates the life of users and packagers by pointing their editor at
10660 the source file containing the definition of the specified packages.
10664 guix edit gcc@@4.9 vim
10668 launches the program specified in the @env{VISUAL} or in the
10669 @env{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
10672 If you are using a Guix Git checkout (@pxref{Building from Git}), or
10673 have created your own packages on @env{GUIX_PACKAGE_PATH}
10674 (@pxref{Package Modules}), you will be able to edit the package
10675 recipes. In other cases, you will be able to examine the read-only recipes
10676 for packages currently in the store.
10678 Instead of @env{GUIX_PACKAGE_PATH}, the command-line option
10679 @option{--load-path=@var{directory}} (or in short @option{-L
10680 @var{directory}}) allows you to add @var{directory} to the front of the
10681 package module search path and so make your own packages visible.
10683 @node Invoking guix download
10684 @section Invoking @command{guix download}
10686 @cindex @command{guix download}
10687 @cindex downloading package sources
10688 When writing a package definition, developers typically need to download
10689 a source tarball, compute its SHA256 hash, and write that
10690 hash in the package definition (@pxref{Defining Packages}). The
10691 @command{guix download} tool helps with this task: it downloads a file
10692 from the given URI, adds it to the store, and prints both its file name
10693 in the store and its SHA256 hash.
10695 The fact that the downloaded file is added to the store saves bandwidth:
10696 when the developer eventually tries to build the newly defined package
10697 with @command{guix build}, the source tarball will not have to be
10698 downloaded again because it is already in the store. It is also a
10699 convenient way to temporarily stash files, which may be deleted
10700 eventually (@pxref{Invoking guix gc}).
10702 The @command{guix download} command supports the same URIs as used in
10703 package definitions. In particular, it supports @code{mirror://} URIs.
10704 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
10705 Guile bindings for GnuTLS are available in the user's environment; when
10706 they are not available, an error is raised. @xref{Guile Preparations,
10707 how to install the GnuTLS bindings for Guile,, gnutls-guile,
10708 GnuTLS-Guile}, for more information.
10710 @command{guix download} verifies HTTPS server certificates by loading
10711 the certificates of X.509 authorities from the directory pointed to by
10712 the @env{SSL_CERT_DIR} environment variable (@pxref{X.509
10713 Certificates}), unless @option{--no-check-certificate} is used.
10715 The following options are available:
10718 @item --hash=@var{algorithm}
10719 @itemx -H @var{algorithm}
10720 Compute a hash using the specified @var{algorithm}. @xref{Invoking guix
10721 hash}, for more information.
10723 @item --format=@var{fmt}
10724 @itemx -f @var{fmt}
10725 Write the hash in the format specified by @var{fmt}. For more
10726 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
10728 @item --no-check-certificate
10729 Do not validate the X.509 certificates of HTTPS servers.
10731 When using this option, you have @emph{absolutely no guarantee} that you
10732 are communicating with the authentic server responsible for the given
10733 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
10735 @item --output=@var{file}
10736 @itemx -o @var{file}
10737 Save the downloaded file to @var{file} instead of adding it to the
10741 @node Invoking guix hash
10742 @section Invoking @command{guix hash}
10744 @cindex @command{guix hash}
10745 The @command{guix hash} command computes the hash of a file.
10746 It is primarily a convenience tool for anyone contributing to the
10747 distribution: it computes the cryptographic hash of a file, which can be
10748 used in the definition of a package (@pxref{Defining Packages}).
10750 The general syntax is:
10753 guix hash @var{option} @var{file}
10756 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
10757 hash of data read from standard input. @command{guix hash} has the
10762 @item --hash=@var{algorithm}
10763 @itemx -H @var{algorithm}
10764 Compute a hash using the specified @var{algorithm}, @code{sha256} by
10767 @var{algorithm} must the name of a cryptographic hash algorithm
10768 supported by Libgcrypt @i{via} Guile-Gcrypt---e.g., @code{sha512} or
10769 @code{sha3-256} (@pxref{Hash Functions,,, guile-gcrypt, Guile-Gcrypt
10770 Reference Manual}).
10772 @item --format=@var{fmt}
10773 @itemx -f @var{fmt}
10774 Write the hash in the format specified by @var{fmt}.
10776 Supported formats: @code{base64}, @code{nix-base32}, @code{base32}, @code{base16}
10777 (@code{hex} and @code{hexadecimal} can be used as well).
10779 If the @option{--format} option is not specified, @command{guix hash}
10780 will output the hash in @code{nix-base32}. This representation is used
10781 in the definitions of packages.
10785 Compute the hash on @var{file} recursively.
10787 In this case, the hash is computed on an archive containing @var{file},
10788 including its children if it is a directory. Some of the metadata of
10789 @var{file} is part of the archive; for instance, when @var{file} is a
10790 regular file, the hash is different depending on whether @var{file} is
10791 executable or not. Metadata such as time stamps has no impact on the
10792 hash (@pxref{Invoking guix archive}).
10793 @c FIXME: Replace xref above with xref to an ``Archive'' section when
10796 @item --exclude-vcs
10798 When combined with @option{--recursive}, exclude version control system
10799 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.).
10802 As an example, here is how you would compute the hash of a Git checkout,
10803 which is useful when using the @code{git-fetch} method (@pxref{origin
10807 $ git clone http://example.org/foo.git
10813 @node Invoking guix import
10814 @section Invoking @command{guix import}
10816 @cindex importing packages
10817 @cindex package import
10818 @cindex package conversion
10819 @cindex Invoking @command{guix import}
10820 The @command{guix import} command is useful for people who would like to
10821 add a package to the distribution with as little work as
10822 possible---a legitimate demand. The command knows of a few
10823 repositories from which it can ``import'' package metadata. The result
10824 is a package definition, or a template thereof, in the format we know
10825 (@pxref{Defining Packages}).
10827 The general syntax is:
10830 guix import @var{importer} @var{options}@dots{}
10833 @var{importer} specifies the source from which to import package
10834 metadata, and @var{options} specifies a package identifier and other
10835 options specific to @var{importer}.
10837 Some of the importers rely on the ability to run the @command{gpgv} command.
10838 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
10841 Currently, the available ``importers'' are:
10845 Import metadata for the given GNU package. This provides a template
10846 for the latest version of that GNU package, including the hash of its
10847 source tarball, and its canonical synopsis and description.
10849 Additional information such as the package dependencies and its
10850 license needs to be figured out manually.
10852 For example, the following command returns a package definition for
10856 guix import gnu hello
10859 Specific command-line options are:
10862 @item --key-download=@var{policy}
10863 As for @command{guix refresh}, specify the policy to handle missing
10864 OpenPGP keys when verifying the package signature. @xref{Invoking guix
10865 refresh, @option{--key-download}}.
10870 Import metadata from the @uref{https://pypi.python.org/, Python Package
10871 Index}. Information is taken from the JSON-formatted description
10872 available at @code{pypi.python.org} and usually includes all the relevant
10873 information, including package dependencies. For maximum efficiency, it
10874 is recommended to install the @command{unzip} utility, so that the
10875 importer can unzip Python wheels and gather data from them.
10877 The command below imports metadata for the @code{itsdangerous} Python
10881 guix import pypi itsdangerous
10887 Traverse the dependency graph of the given upstream package recursively
10888 and generate package expressions for all those packages that are not yet
10894 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
10895 is taken from the JSON-formatted description available at
10896 @code{rubygems.org} and includes most relevant information, including
10897 runtime dependencies. There are some caveats, however. The metadata
10898 doesn't distinguish between synopses and descriptions, so the same string
10899 is used for both fields. Additionally, the details of non-Ruby
10900 dependencies required to build native extensions is unavailable and left
10901 as an exercise to the packager.
10903 The command below imports metadata for the @code{rails} Ruby package:
10906 guix import gem rails
10912 Traverse the dependency graph of the given upstream package recursively
10913 and generate package expressions for all those packages that are not yet
10919 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
10920 Information is taken from the JSON-formatted metadata provided through
10921 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
10922 relevant information, such as module dependencies. License information
10923 should be checked closely. If Perl is available in the store, then the
10924 @code{corelist} utility will be used to filter core modules out of the
10925 list of dependencies.
10927 The command command below imports metadata for the Acme::Boolean Perl
10931 guix import cpan Acme::Boolean
10936 @cindex Bioconductor
10937 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
10938 central repository for the @uref{https://r-project.org, GNU@tie{}R
10939 statistical and graphical environment}.
10941 Information is extracted from the @file{DESCRIPTION} file of the package.
10943 The command command below imports metadata for the Cairo R package:
10946 guix import cran Cairo
10949 When @option{--recursive} is added, the importer will traverse the
10950 dependency graph of the given upstream package recursively and generate
10951 package expressions for all those packages that are not yet in Guix.
10953 When @option{--archive=bioconductor} is added, metadata is imported from
10954 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
10955 packages for the analysis and comprehension of high-throughput
10956 genomic data in bioinformatics.
10958 Information is extracted from the @file{DESCRIPTION} file contained in the
10961 The command below imports metadata for the GenomicRanges R package:
10964 guix import cran --archive=bioconductor GenomicRanges
10967 Finally, you can also import R packages that have not yet been published on
10968 CRAN or Bioconductor as long as they are in a git repository. Use
10969 @option{--archive=git} followed by the URL of the git repository:
10972 guix import cran --archive=git https://github.com/immunogenomics/harmony
10978 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
10979 comprehensive TeX archive network for TeX packages that are part of the
10980 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
10982 Information about the package is obtained through the XML API provided
10983 by CTAN, while the source code is downloaded from the SVN repository of
10984 the Tex Live project. This is done because the CTAN does not keep
10985 versioned archives.
10987 The command command below imports metadata for the @code{fontspec}
10991 guix import texlive fontspec
10994 When @option{--archive=@var{directory}} is added, the source code is
10995 downloaded not from the @file{latex} sub-directory of the
10996 @file{texmf-dist/source} tree in the TeX Live SVN repository, but from
10997 the specified sibling @var{directory} under the same root.
10999 The command below imports metadata for the @code{ifxetex} package from
11000 CTAN while fetching the sources from the directory
11001 @file{texmf/source/generic}:
11004 guix import texlive --archive=generic ifxetex
11008 @cindex JSON, import
11009 Import package metadata from a local JSON file. Consider the following
11010 example package definition in JSON format:
11016 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
11017 "build-system": "gnu",
11018 "home-page": "https://www.gnu.org/software/hello/",
11019 "synopsis": "Hello, GNU world: An example GNU package",
11020 "description": "GNU Hello prints a greeting.",
11021 "license": "GPL-3.0+",
11022 "native-inputs": ["gettext"]
11026 The field names are the same as for the @code{<package>} record
11027 (@xref{Defining Packages}). References to other packages are provided
11028 as JSON lists of quoted package specification strings such as
11029 @code{guile} or @code{guile@@2.0}.
11031 The importer also supports a more explicit source definition using the
11032 common fields for @code{<origin>} records:
11038 "method": "url-fetch",
11039 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
11041 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
11048 The command below reads metadata from the JSON file @code{hello.json}
11049 and outputs a package expression:
11052 guix import json hello.json
11056 Import metadata from a local copy of the source of the
11057 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
11058 relies on the @command{nix-instantiate} command of
11059 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
11060 typically written in a mixture of Nix-language and Bash code. This
11061 command only imports the high-level package structure that is written in
11062 the Nix language. It normally includes all the basic fields of a
11063 package definition.
11065 When importing a GNU package, the synopsis and descriptions are replaced
11066 by their canonical upstream variant.
11068 Usually, you will first need to do:
11071 export NIX_REMOTE=daemon
11075 so that @command{nix-instantiate} does not try to open the Nix database.
11077 As an example, the command below imports the package definition of
11078 LibreOffice (more precisely, it imports the definition of the package
11079 bound to the @code{libreoffice} top-level attribute):
11082 guix import nix ~/path/to/nixpkgs libreoffice
11087 Import metadata from the Haskell community's central package archive
11088 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
11089 Cabal files and includes all the relevant information, including package
11092 Specific command-line options are:
11097 Read a Cabal file from standard input.
11098 @item --no-test-dependencies
11100 Do not include dependencies required only by the test suites.
11101 @item --cabal-environment=@var{alist}
11102 @itemx -e @var{alist}
11103 @var{alist} is a Scheme alist defining the environment in which the
11104 Cabal conditionals are evaluated. The accepted keys are: @code{os},
11105 @code{arch}, @code{impl} and a string representing the name of a flag.
11106 The value associated with a flag has to be either the symbol
11107 @code{true} or @code{false}. The value associated with other keys
11108 has to conform to the Cabal file format definition. The default value
11109 associated with the keys @code{os}, @code{arch} and @code{impl} is
11110 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
11113 Traverse the dependency graph of the given upstream package recursively
11114 and generate package expressions for all those packages that are not yet
11118 The command below imports metadata for the latest version of the
11119 HTTP Haskell package without including test dependencies and
11120 specifying the value of the flag @samp{network-uri} as @code{false}:
11123 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
11126 A specific package version may optionally be specified by following the
11127 package name by an at-sign and a version number as in the following example:
11130 guix import hackage mtl@@2.1.3.1
11135 The @code{stackage} importer is a wrapper around the @code{hackage} one.
11136 It takes a package name, looks up the package version included in a
11137 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
11138 release and uses the @code{hackage} importer to retrieve its metadata.
11139 Note that it is up to you to select an LTS release compatible with the
11140 GHC compiler used by Guix.
11142 Specific command-line options are:
11145 @item --no-test-dependencies
11147 Do not include dependencies required only by the test suites.
11148 @item --lts-version=@var{version}
11149 @itemx -l @var{version}
11150 @var{version} is the desired LTS release version. If omitted the latest
11154 Traverse the dependency graph of the given upstream package recursively
11155 and generate package expressions for all those packages that are not yet
11159 The command below imports metadata for the HTTP Haskell package
11160 included in the LTS Stackage release version 7.18:
11163 guix import stackage --lts-version=7.18 HTTP
11168 Import metadata from an Emacs Lisp Package Archive (ELPA) package
11169 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
11171 Specific command-line options are:
11174 @item --archive=@var{repo}
11175 @itemx -a @var{repo}
11176 @var{repo} identifies the archive repository from which to retrieve the
11177 information. Currently the supported repositories and their identifiers
11181 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
11182 identifier. This is the default.
11184 Packages from @code{elpa.gnu.org} are signed with one of the keys
11185 contained in the GnuPG keyring at
11186 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
11187 @code{emacs} package (@pxref{Package Installation, ELPA package
11188 signatures,, emacs, The GNU Emacs Manual}).
11191 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
11192 @code{melpa-stable} identifier.
11195 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
11201 Traverse the dependency graph of the given upstream package recursively
11202 and generate package expressions for all those packages that are not yet
11208 Import metadata from the crates.io Rust package repository
11209 @uref{https://crates.io, crates.io}, as in this example:
11212 guix import crate blake2-rfc
11215 The crate importer also allows you to specify a version string:
11218 guix import crate constant-time-eq@@0.1.0
11221 Additional options include:
11226 Traverse the dependency graph of the given upstream package recursively
11227 and generate package expressions for all those packages that are not yet
11234 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
11235 repository used by the OCaml community.
11238 The structure of the @command{guix import} code is modular. It would be
11239 useful to have more importers for other package formats, and your help
11240 is welcome here (@pxref{Contributing}).
11242 @node Invoking guix refresh
11243 @section Invoking @command{guix refresh}
11245 @cindex @command {guix refresh}
11246 The primary audience of the @command{guix refresh} command is developers
11247 of the GNU software distribution. By default, it reports any packages
11248 provided by the distribution that are outdated compared to the latest
11249 upstream version, like this:
11253 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
11254 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
11257 Alternatively, one can specify packages to consider, in which case a
11258 warning is emitted for packages that lack an updater:
11261 $ guix refresh coreutils guile guile-ssh
11262 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
11263 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
11266 @command{guix refresh} browses the upstream repository of each package and determines
11267 the highest version number of the releases therein. The command
11268 knows how to update specific types of packages: GNU packages, ELPA
11269 packages, etc.---see the documentation for @option{--type} below. There
11270 are many packages, though, for which it lacks a method to determine
11271 whether a new upstream release is available. However, the mechanism is
11272 extensible, so feel free to get in touch with us to add a new method!
11277 Consider the packages specified, and all the packages upon which they depend.
11280 $ guix refresh --recursive coreutils
11281 gnu/packages/acl.scm:35:2: warning: no updater for acl
11282 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
11283 gnu/packages/xml.scm:68:2: warning: no updater for expat
11284 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
11290 Sometimes the upstream name differs from the package name used in Guix,
11291 and @command{guix refresh} needs a little help. Most updaters honor the
11292 @code{upstream-name} property in package definitions, which can be used
11296 (define-public network-manager
11298 (name "network-manager")
11300 (properties '((upstream-name . "NetworkManager")))))
11303 When passed @option{--update}, it modifies distribution source files to
11304 update the version numbers and source tarball hashes of those package
11305 recipes (@pxref{Defining Packages}). This is achieved by downloading
11306 each package's latest source tarball and its associated OpenPGP
11307 signature, authenticating the downloaded tarball against its signature
11308 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
11309 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
11312 key used to sign the tarball is missing from the user's keyring, an
11313 attempt is made to automatically retrieve it from a public key server;
11314 when this is successful, the key is added to the user's keyring; otherwise,
11315 @command{guix refresh} reports an error.
11317 The following options are supported:
11321 @item --expression=@var{expr}
11322 @itemx -e @var{expr}
11323 Consider the package @var{expr} evaluates to.
11325 This is useful to precisely refer to a package, as in this example:
11328 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
11331 This command lists the dependents of the ``final'' libc (essentially all
11336 Update distribution source files (package recipes) in place. This is
11337 usually run from a checkout of the Guix source tree (@pxref{Running
11338 Guix Before It Is Installed}):
11341 $ ./pre-inst-env guix refresh -s non-core -u
11344 @xref{Defining Packages}, for more information on package definitions.
11346 @item --select=[@var{subset}]
11347 @itemx -s @var{subset}
11348 Select all the packages in @var{subset}, one of @code{core} or
11351 The @code{core} subset refers to all the packages at the core of the
11352 distribution---i.e., packages that are used to build ``everything
11353 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
11354 changing one of these packages in the distribution entails a rebuild of
11355 all the others. Thus, such updates are an inconvenience to users in
11356 terms of build time or bandwidth used to achieve the upgrade.
11358 The @code{non-core} subset refers to the remaining packages. It is
11359 typically useful in cases where an update of the core packages would be
11362 @item --manifest=@var{file}
11363 @itemx -m @var{file}
11364 Select all the packages from the manifest in @var{file}. This is useful to
11365 check if any packages of the user manifest can be updated.
11367 @item --type=@var{updater}
11368 @itemx -t @var{updater}
11369 Select only packages handled by @var{updater} (may be a comma-separated
11370 list of updaters). Currently, @var{updater} may be one of:
11374 the updater for GNU packages;
11376 the updater for packages hosted at @uref{https://savannah.gnu.org, Savannah};
11378 the updater for GNOME packages;
11380 the updater for KDE packages;
11382 the updater for X.org packages;
11384 the updater for packages hosted on kernel.org;
11386 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
11388 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
11390 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
11392 the updater for @uref{https://www.cpan.org/, CPAN} packages;
11394 the updater for @uref{https://pypi.python.org, PyPI} packages.
11396 the updater for @uref{https://rubygems.org, RubyGems} packages.
11398 the updater for @uref{https://github.com, GitHub} packages.
11400 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
11402 the updater for @uref{https://www.stackage.org, Stackage} packages.
11404 the updater for @uref{https://crates.io, Crates} packages.
11406 the updater for @uref{https://launchpad.net, Launchpad} packages.
11409 For instance, the following command only checks for updates of Emacs
11410 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
11413 $ guix refresh --type=elpa,cran
11414 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
11415 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
11420 In addition, @command{guix refresh} can be passed one or more package
11421 names, as in this example:
11424 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
11428 The command above specifically updates the @code{emacs} and
11429 @code{idutils} packages. The @option{--select} option would have no
11430 effect in this case.
11432 When considering whether to upgrade a package, it is sometimes
11433 convenient to know which packages would be affected by the upgrade and
11434 should be checked for compatibility. For this the following option may
11435 be used when passing @command{guix refresh} one or more package names:
11439 @item --list-updaters
11441 List available updaters and exit (see @option{--type} above).
11443 For each updater, display the fraction of packages it covers; at the
11444 end, display the fraction of packages covered by all these updaters.
11446 @item --list-dependent
11448 List top-level dependent packages that would need to be rebuilt as a
11449 result of upgrading one or more packages.
11451 @xref{Invoking guix graph, the @code{reverse-package} type of
11452 @command{guix graph}}, for information on how to visualize the list of
11453 dependents of a package.
11457 Be aware that the @option{--list-dependent} option only
11458 @emph{approximates} the rebuilds that would be required as a result of
11459 an upgrade. More rebuilds might be required under some circumstances.
11462 $ guix refresh --list-dependent flex
11463 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
11464 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
11467 The command above lists a set of packages that could be built to check
11468 for compatibility with an upgraded @code{flex} package.
11472 @item --list-transitive
11473 List all the packages which one or more packages depend upon.
11476 $ guix refresh --list-transitive flex
11477 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
11478 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{}
11483 The command above lists a set of packages which, when changed, would cause
11484 @code{flex} to be rebuilt.
11486 The following options can be used to customize GnuPG operation:
11490 @item --gpg=@var{command}
11491 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
11492 for in @code{$PATH}.
11494 @item --keyring=@var{file}
11495 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
11496 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
11497 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
11498 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
11499 information on a tool to manipulate keybox files).
11501 When this option is omitted, @command{guix refresh} uses
11502 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
11503 signing keys. OpenPGP signatures are checked against keys from this keyring;
11504 missing keys are downloaded to this keyring as well (see
11505 @option{--key-download} below).
11507 You can export keys from your default GPG keyring into a keybox file using
11508 commands like this one:
11511 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
11514 Likewise, you can fetch keys to a specific keybox file like this:
11517 gpg --no-default-keyring --keyring mykeyring.kbx \
11518 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
11521 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
11522 Privacy Guard}, for more information on GPG's @option{--keyring} option.
11524 @item --key-download=@var{policy}
11525 Handle missing OpenPGP keys according to @var{policy}, which may be one
11530 Always download missing OpenPGP keys from the key server, and add them
11531 to the user's GnuPG keyring.
11534 Never try to download missing OpenPGP keys. Instead just bail out.
11537 When a package signed with an unknown OpenPGP key is encountered, ask
11538 the user whether to download it or not. This is the default behavior.
11541 @item --key-server=@var{host}
11542 Use @var{host} as the OpenPGP key server when importing a public key.
11544 @item --load-path=@var{directory}
11545 Add @var{directory} to the front of the package module search path
11546 (@pxref{Package Modules}).
11548 This allows users to define their own packages and make them visible to
11549 the command-line tools.
11553 The @code{github} updater uses the
11554 @uref{https://developer.github.com/v3/, GitHub API} to query for new
11555 releases. When used repeatedly e.g.@: when refreshing all packages,
11556 GitHub will eventually refuse to answer any further API requests. By
11557 default 60 API requests per hour are allowed, and a full refresh on all
11558 GitHub packages in Guix requires more than this. Authentication with
11559 GitHub through the use of an API token alleviates these limits. To use
11560 an API token, set the environment variable @env{GUIX_GITHUB_TOKEN} to a
11561 token procured from @uref{https://github.com/settings/tokens} or
11565 @node Invoking guix lint
11566 @section Invoking @command{guix lint}
11568 @cindex @command{guix lint}
11569 @cindex package, checking for errors
11570 The @command{guix lint} command is meant to help package developers avoid
11571 common errors and use a consistent style. It runs a number of checks on
11572 a given set of packages in order to find common mistakes in their
11573 definitions. Available @dfn{checkers} include (see
11574 @option{--list-checkers} for a complete list):
11579 Validate certain typographical and stylistic rules about package
11580 descriptions and synopses.
11582 @item inputs-should-be-native
11583 Identify inputs that should most likely be native inputs.
11589 @itemx source-file-name
11590 Probe @code{home-page} and @code{source} URLs and report those that are
11591 invalid. Suggest a @code{mirror://} URL when applicable. If the
11592 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
11593 URL. Check that the source file name is meaningful, e.g.@: is not just a
11594 version number or ``git-checkout'', without a declared @code{file-name}
11595 (@pxref{origin Reference}).
11597 @item source-unstable-tarball
11598 Parse the @code{source} URL to determine if a tarball from GitHub is
11599 autogenerated or if it is a release tarball. Unfortunately GitHub's
11600 autogenerated tarballs are sometimes regenerated.
11603 Check that the derivation of the given packages can be successfully
11604 computed for all the supported systems (@pxref{Derivations}).
11606 @item profile-collisions
11607 Check whether installing the given packages in a profile would lead to
11608 collisions. Collisions occur when several packages with the same name
11609 but a different version or a different store file name are propagated.
11610 @xref{package Reference, @code{propagated-inputs}}, for more information
11611 on propagated inputs.
11614 @cindex Software Heritage, source code archive
11615 @cindex archival of source code, Software Heritage
11616 Checks whether the package's source code is archived at
11617 @uref{https://www.softwareheritage.org, Software Heritage}.
11619 When the source code that is not archived comes from a version-control system
11620 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
11621 ``save'' request so that it eventually archives it. This ensures that the
11622 source will remain available in the long term, and that Guix can fall back to
11623 Software Heritage should the source code disappear from its original host.
11624 The status of recent ``save'' requests can be
11625 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
11627 When source code is a tarball obtained with @code{url-fetch}, simply print a
11628 message when it is not archived. As of this writing, Software Heritage does
11629 not allow requests to save arbitrary tarballs; we are working on ways to
11630 ensure that non-VCS source code is also archived.
11633 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
11634 request rate per IP address}. When the limit is reached, @command{guix lint}
11635 prints a message and the @code{archival} checker stops doing anything until
11636 that limit has been reset.
11639 @cindex security vulnerabilities
11640 @cindex CVE, Common Vulnerabilities and Exposures
11641 Report known vulnerabilities found in the Common Vulnerabilities and
11642 Exposures (CVE) databases of the current and past year
11643 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
11646 To view information about a particular vulnerability, visit pages such as:
11650 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
11652 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
11656 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
11657 @code{CVE-2015-7554}.
11659 Package developers can specify in package recipes the
11660 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
11661 name and version of the package when they differ from the name or version
11662 that Guix uses, as in this example:
11668 ;; CPE calls this package "grub2".
11669 (properties '((cpe-name . "grub2")
11670 (cpe-version . "2.3"))))
11673 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
11674 Some entries in the CVE database do not specify which version of a
11675 package they apply to, and would thus ``stick around'' forever. Package
11676 developers who found CVE alerts and verified they can be ignored can
11677 declare them as in this example:
11683 ;; These CVEs no longer apply and can be safely ignored.
11684 (properties `((lint-hidden-cve . ("CVE-2011-0433"
11687 "CVE-2011-5244")))))
11691 Warn about obvious source code formatting issues: trailing white space,
11692 use of tabulations, etc.
11695 The general syntax is:
11698 guix lint @var{options} @var{package}@dots{}
11701 If no package is given on the command line, then all packages are checked.
11702 The @var{options} may be zero or more of the following:
11705 @item --list-checkers
11707 List and describe all the available checkers that will be run on packages
11712 Only enable the checkers specified in a comma-separated list using the
11713 names returned by @option{--list-checkers}.
11717 Only disable the checkers specified in a comma-separated list using the
11718 names returned by @option{--list-checkers}.
11722 Only enable the checkers that do not depend on Internet access.
11724 @item --load-path=@var{directory}
11725 @itemx -L @var{directory}
11726 Add @var{directory} to the front of the package module search path
11727 (@pxref{Package Modules}).
11729 This allows users to define their own packages and make them visible to
11730 the command-line tools.
11734 @node Invoking guix size
11735 @section Invoking @command{guix size}
11738 @cindex package size
11740 @cindex @command{guix size}
11741 The @command{guix size} command helps package developers profile the
11742 disk usage of packages. It is easy to overlook the impact of an
11743 additional dependency added to a package, or the impact of using a
11744 single output for a package that could easily be split (@pxref{Packages
11745 with Multiple Outputs}). Such are the typical issues that
11746 @command{guix size} can highlight.
11748 The command can be passed one or more package specifications
11749 such as @code{gcc@@4.8}
11750 or @code{guile:debug}, or a file name in the store. Consider this
11754 $ guix size coreutils
11755 store item total self
11756 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
11757 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
11758 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
11759 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
11760 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
11761 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
11762 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
11763 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
11768 The store items listed here constitute the @dfn{transitive closure} of
11769 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
11770 would be returned by:
11773 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
11776 Here the output shows three columns next to store items. The first column,
11777 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
11778 the store item---that is, its own size plus the size of all its
11779 dependencies. The next column, labeled ``self'', shows the size of the
11780 item itself. The last column shows the ratio of the size of the item
11781 itself to the space occupied by all the items listed here.
11783 In this example, we see that the closure of Coreutils weighs in at
11784 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
11785 libraries. (That libc and GCC's libraries represent a large fraction of
11786 the closure is not a problem @i{per se} because they are always available
11787 on the system anyway.)
11789 Since the command also accepts store file names, assessing the size of
11790 a build result is straightforward:
11793 guix size $(guix system build config.scm)
11796 When the package(s) passed to @command{guix size} are available in the
11797 store@footnote{More precisely, @command{guix size} looks for the
11798 @emph{ungrafted} variant of the given package(s), as returned by
11799 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
11800 for information on grafts.}, @command{guix size} queries the daemon to determine its
11801 dependencies, and measures its size in the store, similar to @command{du
11802 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
11805 When the given packages are @emph{not} in the store, @command{guix size}
11806 reports information based on the available substitutes
11807 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
11808 store items that are not even on disk, only available remotely.
11810 You can also specify several package names:
11813 $ guix size coreutils grep sed bash
11814 store item total self
11815 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
11816 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
11817 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
11818 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
11824 In this example we see that the combination of the four packages takes
11825 102.3@tie{}MiB in total, which is much less than the sum of each closure
11826 since they have a lot of dependencies in common.
11828 When looking at the profile returned by @command{guix size}, you may
11829 find yourself wondering why a given package shows up in the profile at
11830 all. To understand it, you can use @command{guix graph --path -t
11831 references} to display the shortest path between the two packages
11832 (@pxref{Invoking guix graph}).
11834 The available options are:
11838 @item --substitute-urls=@var{urls}
11839 Use substitute information from @var{urls}.
11840 @xref{client-substitute-urls, the same option for @code{guix build}}.
11842 @item --sort=@var{key}
11843 Sort lines according to @var{key}, one of the following options:
11847 the size of each item (the default);
11849 the total size of the item's closure.
11852 @item --map-file=@var{file}
11853 Write a graphical map of disk usage in PNG format to @var{file}.
11855 For the example above, the map looks like this:
11857 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
11858 produced by @command{guix size}}
11860 This option requires that
11861 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
11862 installed and visible in Guile's module search path. When that is not
11863 the case, @command{guix size} fails as it tries to load it.
11865 @item --system=@var{system}
11866 @itemx -s @var{system}
11867 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
11869 @item --load-path=@var{directory}
11870 @itemx -L @var{directory}
11871 Add @var{directory} to the front of the package module search path
11872 (@pxref{Package Modules}).
11874 This allows users to define their own packages and make them visible to
11875 the command-line tools.
11878 @node Invoking guix graph
11879 @section Invoking @command{guix graph}
11882 @cindex @command{guix graph}
11883 @cindex package dependencies
11884 Packages and their dependencies form a @dfn{graph}, specifically a
11885 directed acyclic graph (DAG). It can quickly become difficult to have a
11886 mental model of the package DAG, so the @command{guix graph} command
11887 provides a visual representation of the DAG. By default,
11888 @command{guix graph} emits a DAG representation in the input format of
11889 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
11890 directly to the @command{dot} command of Graphviz. It can also emit an
11891 HTML page with embedded JavaScript code to display a ``chord diagram''
11892 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
11893 emit Cypher queries to construct a graph in a graph database supporting
11894 the @uref{https://www.opencypher.org/, openCypher} query language. With
11895 @option{--path}, it simply displays the shortest path between two
11896 packages. The general syntax is:
11899 guix graph @var{options} @var{package}@dots{}
11902 For example, the following command generates a PDF file representing the
11903 package DAG for the GNU@tie{}Core Utilities, showing its build-time
11907 guix graph coreutils | dot -Tpdf > dag.pdf
11910 The output looks like this:
11912 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
11914 Nice little graph, no?
11916 You may find it more pleasant to navigate the graph interactively with
11917 @command{xdot} (from the @code{xdot} package):
11920 guix graph coreutils | xdot -
11923 But there is more than one graph! The one above is concise: it is the
11924 graph of package objects, omitting implicit inputs such as GCC, libc,
11925 grep, etc. It is often useful to have such a concise graph, but
11926 sometimes one may want to see more details. @command{guix graph} supports
11927 several types of graphs, allowing you to choose the level of detail:
11931 This is the default type used in the example above. It shows the DAG of
11932 package objects, excluding implicit dependencies. It is concise, but
11933 filters out many details.
11935 @item reverse-package
11936 This shows the @emph{reverse} DAG of packages. For example:
11939 guix graph --type=reverse-package ocaml
11942 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
11943 you are also interested in cases where OCaml is an implicit dependency, see
11944 @code{reverse-bag} below).
11946 Note that for core packages this can yield huge graphs. If all you want
11947 is to know the number of packages that depend on a given package, use
11948 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
11949 @option{--list-dependent}}).
11952 This is the package DAG, @emph{including} implicit inputs.
11954 For instance, the following command:
11957 guix graph --type=bag-emerged coreutils
11960 ...@: yields this bigger graph:
11962 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
11964 At the bottom of the graph, we see all the implicit inputs of
11965 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
11967 Now, note that the dependencies of these implicit inputs---that is, the
11968 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
11969 here, for conciseness.
11972 Similar to @code{bag-emerged}, but this time including all the bootstrap
11975 @item bag-with-origins
11976 Similar to @code{bag}, but also showing origins and their dependencies.
11979 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
11980 it also takes implicit dependencies into account. For example:
11983 guix graph -t reverse-bag dune
11987 ...@: yields the graph of all packages that depend on Dune, directly or
11988 indirectly. Since Dune is an @emph{implicit} dependency of many packages
11989 @i{via} @code{dune-build-system}, this shows a large number of packages,
11990 whereas @code{reverse-package} would show very few if any.
11993 This is the most detailed representation: It shows the DAG of
11994 derivations (@pxref{Derivations}) and plain store items. Compared to
11995 the above representation, many additional nodes are visible, including
11996 build scripts, patches, Guile modules, etc.
11998 For this type of graph, it is also possible to pass a @file{.drv} file
11999 name instead of a package name, as in:
12002 guix graph -t derivation `guix system build -d my-config.scm`
12006 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
12007 For example, the following command shows the graph for the package
12008 module that defines the @code{guile} package:
12011 guix graph -t module guile | xdot -
12015 All the types above correspond to @emph{build-time dependencies}. The
12016 following graph type represents the @emph{run-time dependencies}:
12020 This is the graph of @dfn{references} of a package output, as returned
12021 by @command{guix gc --references} (@pxref{Invoking guix gc}).
12023 If the given package output is not available in the store, @command{guix
12024 graph} attempts to obtain dependency information from substitutes.
12026 Here you can also pass a store file name instead of a package name. For
12027 example, the command below produces the reference graph of your profile
12028 (which can be big!):
12031 guix graph -t references `readlink -f ~/.guix-profile`
12035 This is the graph of the @dfn{referrers} of a store item, as returned by
12036 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
12038 This relies exclusively on local information from your store. For
12039 instance, let us suppose that the current Inkscape is available in 10
12040 profiles on your machine; @command{guix graph -t referrers inkscape}
12041 will show a graph rooted at Inkscape and with those 10 profiles linked
12044 It can help determine what is preventing a store item from being garbage
12049 @cindex shortest path, between packages
12050 Often, the graph of the package you are interested in does not fit on
12051 your screen, and anyway all you want to know is @emph{why} that package
12052 actually depends on some seemingly unrelated package. The
12053 @option{--path} option instructs @command{guix graph} to display the
12054 shortest path between two packages (or derivations, or store items,
12058 $ guix graph --path emacs libunistring
12061 libunistring@@0.9.10
12062 $ guix graph --path -t derivation emacs libunistring
12063 /gnu/store/@dots{}-emacs-26.3.drv
12064 /gnu/store/@dots{}-mailutils-3.9.drv
12065 /gnu/store/@dots{}-libunistring-0.9.10.drv
12066 $ guix graph --path -t references emacs libunistring
12067 /gnu/store/@dots{}-emacs-26.3
12068 /gnu/store/@dots{}-libidn2-2.2.0
12069 /gnu/store/@dots{}-libunistring-0.9.10
12072 The available options are the following:
12075 @item --type=@var{type}
12076 @itemx -t @var{type}
12077 Produce a graph output of @var{type}, where @var{type} must be one of
12078 the values listed above.
12081 List the supported graph types.
12083 @item --backend=@var{backend}
12084 @itemx -b @var{backend}
12085 Produce a graph using the selected @var{backend}.
12087 @item --list-backends
12088 List the supported graph backends.
12090 Currently, the available backends are Graphviz and d3.js.
12093 Display the shortest path between two nodes of the type specified by
12094 @option{--type}. The example below shows the shortest path between
12095 @code{libreoffice} and @code{llvm} according to the references of
12096 @code{libreoffice}:
12099 $ guix graph --path -t references libreoffice llvm
12100 /gnu/store/@dots{}-libreoffice-6.4.2.2
12101 /gnu/store/@dots{}-libepoxy-1.5.4
12102 /gnu/store/@dots{}-mesa-19.3.4
12103 /gnu/store/@dots{}-llvm-9.0.1
12106 @item --expression=@var{expr}
12107 @itemx -e @var{expr}
12108 Consider the package @var{expr} evaluates to.
12110 This is useful to precisely refer to a package, as in this example:
12113 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
12116 @item --system=@var{system}
12117 @itemx -s @var{system}
12118 Display the graph for @var{system}---e.g., @code{i686-linux}.
12120 The package dependency graph is largely architecture-independent, but there
12121 are some architecture-dependent bits that this option allows you to visualize.
12123 @item --load-path=@var{directory}
12124 @itemx -L @var{directory}
12125 Add @var{directory} to the front of the package module search path
12126 (@pxref{Package Modules}).
12128 This allows users to define their own packages and make them visible to
12129 the command-line tools.
12132 On top of that, @command{guix graph} supports all the usual package
12133 transformation options (@pxref{Package Transformation Options}). This
12134 makes it easy to view the effect of a graph-rewriting transformation
12135 such as @option{--with-input}. For example, the command below outputs
12136 the graph of @code{git} once @code{openssl} has been replaced by
12137 @code{libressl} everywhere in the graph:
12140 guix graph git --with-input=openssl=libressl
12143 So many possibilities, so much fun!
12145 @node Invoking guix publish
12146 @section Invoking @command{guix publish}
12148 @cindex @command{guix publish}
12149 The purpose of @command{guix publish} is to enable users to easily share
12150 their store with others, who can then use it as a substitute server
12151 (@pxref{Substitutes}).
12153 When @command{guix publish} runs, it spawns an HTTP server which allows
12154 anyone with network access to obtain substitutes from it. This means
12155 that any machine running Guix can also act as if it were a build farm,
12156 since the HTTP interface is compatible with Cuirass, the software behind
12157 the @code{@value{SUBSTITUTE-SERVER}} build farm.
12159 For security, each substitute is signed, allowing recipients to check
12160 their authenticity and integrity (@pxref{Substitutes}). Because
12161 @command{guix publish} uses the signing key of the system, which is only
12162 readable by the system administrator, it must be started as root; the
12163 @option{--user} option makes it drop root privileges early on.
12165 The signing key pair must be generated before @command{guix publish} is
12166 launched, using @command{guix archive --generate-key} (@pxref{Invoking
12169 The general syntax is:
12172 guix publish @var{options}@dots{}
12175 Running @command{guix publish} without any additional arguments will
12176 spawn an HTTP server on port 8080:
12182 Once a publishing server has been authorized, the daemon may download
12183 substitutes from it. @xref{Getting Substitutes from Other Servers}.
12185 By default, @command{guix publish} compresses archives on the fly as it
12186 serves them. This ``on-the-fly'' mode is convenient in that it requires
12187 no setup and is immediately available. However, when serving lots of
12188 clients, we recommend using the @option{--cache} option, which enables
12189 caching of the archives before they are sent to clients---see below for
12190 details. The @command{guix weather} command provides a handy way to
12191 check what a server provides (@pxref{Invoking guix weather}).
12193 As a bonus, @command{guix publish} also serves as a content-addressed
12194 mirror for source files referenced in @code{origin} records
12195 (@pxref{origin Reference}). For instance, assuming @command{guix
12196 publish} is running on @code{example.org}, the following URL returns the
12197 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
12198 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
12201 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
12204 Obviously, these URLs only work for files that are in the store; in
12205 other cases, they return 404 (``Not Found'').
12207 @cindex build logs, publication
12208 Build logs are available from @code{/log} URLs like:
12211 http://example.org/log/gwspk@dots{}-guile-2.2.3
12215 When @command{guix-daemon} is configured to save compressed build logs,
12216 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
12217 URLs return the compressed log as-is, with an appropriate
12218 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
12219 running @command{guix-daemon} with @option{--log-compression=gzip} since
12220 Web browsers can automatically decompress it, which is not the case with
12223 The following options are available:
12226 @item --port=@var{port}
12227 @itemx -p @var{port}
12228 Listen for HTTP requests on @var{port}.
12230 @item --listen=@var{host}
12231 Listen on the network interface for @var{host}. The default is to
12232 accept connections from any interface.
12234 @item --user=@var{user}
12235 @itemx -u @var{user}
12236 Change privileges to @var{user} as soon as possible---i.e., once the
12237 server socket is open and the signing key has been read.
12239 @item --compression[=@var{method}[:@var{level}]]
12240 @itemx -C [@var{method}[:@var{level}]]
12241 Compress data using the given @var{method} and @var{level}. @var{method} is
12242 one of @code{lzip} and @code{gzip}; when @var{method} is omitted, @code{gzip}
12245 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
12246 to different compression levels: 1 is the fastest, and 9 is the best
12247 (CPU-intensive). The default is 3.
12249 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a small
12250 increase in CPU usage; see
12251 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip Web
12254 Unless @option{--cache} is used, compression occurs on the fly and
12255 the compressed streams are not
12256 cached. Thus, to reduce load on the machine that runs @command{guix
12257 publish}, it may be a good idea to choose a low compression level, to
12258 run @command{guix publish} behind a caching proxy, or to use
12259 @option{--cache}. Using @option{--cache} has the advantage that it
12260 allows @command{guix publish} to add @code{Content-Length} HTTP header
12263 This option can be repeated, in which case every substitute gets compressed
12264 using all the selected methods, and all of them are advertised. This is
12265 useful when users may not support all the compression methods: they can select
12266 the one they support.
12268 @item --cache=@var{directory}
12269 @itemx -c @var{directory}
12270 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
12271 and only serve archives that are in cache.
12273 When this option is omitted, archives and meta-data are created
12274 on-the-fly. This can reduce the available bandwidth, especially when
12275 compression is enabled, since this may become CPU-bound. Another
12276 drawback of the default mode is that the length of archives is not known
12277 in advance, so @command{guix publish} does not add a
12278 @code{Content-Length} HTTP header to its responses, which in turn
12279 prevents clients from knowing the amount of data being downloaded.
12281 Conversely, when @option{--cache} is used, the first request for a store
12282 item (@i{via} a @code{.narinfo} URL) triggers a
12283 background process to @dfn{bake} the archive---computing its
12284 @code{.narinfo} and compressing the archive, if needed. Once the
12285 archive is cached in @var{directory}, subsequent requests succeed and
12286 are served directly from the cache, which guarantees that clients get
12287 the best possible bandwidth.
12289 That first @code{.narinfo} request nonetheless returns 200, provided the
12290 requested store item is ``small enough'', below the cache bypass
12291 threshold---see @option{--cache-bypass-threshold} below. That way,
12292 clients do not have to wait until the archive is baked. For larger
12293 store items, the first @code{.narinfo} request returns 404, meaning that
12294 clients have to wait until the archive is baked.
12296 The ``baking'' process is performed by worker threads. By default, one
12297 thread per CPU core is created, but this can be customized. See
12298 @option{--workers} below.
12300 When @option{--ttl} is used, cached entries are automatically deleted
12301 when they have expired.
12303 @item --workers=@var{N}
12304 When @option{--cache} is used, request the allocation of @var{N} worker
12305 threads to ``bake'' archives.
12307 @item --ttl=@var{ttl}
12308 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
12309 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
12310 days, @code{1m} means 1 month, and so on.
12312 This allows the user's Guix to keep substitute information in cache for
12313 @var{ttl}. However, note that @code{guix publish} does not itself
12314 guarantee that the store items it provides will indeed remain available
12315 for as long as @var{ttl}.
12317 Additionally, when @option{--cache} is used, cached entries that have
12318 not been accessed for @var{ttl} and that no longer have a corresponding
12319 item in the store, may be deleted.
12321 @item --cache-bypass-threshold=@var{size}
12322 When used in conjunction with @option{--cache}, store items smaller than
12323 @var{size} are immediately available, even when they are not yet in
12324 cache. @var{size} is a size in bytes, or it can be suffixed by @code{M}
12325 for megabytes and so on. The default is @code{10M}.
12327 ``Cache bypass'' allows you to reduce the publication delay for clients
12328 at the expense of possibly additional I/O and CPU use on the server
12329 side: depending on the client access patterns, those store items can end
12330 up being baked several times until a copy is available in cache.
12332 Increasing the threshold may be useful for sites that have few users, or
12333 to guarantee that users get substitutes even for store items that are
12336 @item --nar-path=@var{path}
12337 Use @var{path} as the prefix for the URLs of ``nar'' files
12338 (@pxref{Invoking guix archive, normalized archives}).
12340 By default, nars are served at a URL such as
12341 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
12342 change the @code{/nar} part to @var{path}.
12344 @item --public-key=@var{file}
12345 @itemx --private-key=@var{file}
12346 Use the specific @var{file}s as the public/private key pair used to sign
12347 the store items being published.
12349 The files must correspond to the same key pair (the private key is used
12350 for signing and the public key is merely advertised in the signature
12351 metadata). They must contain keys in the canonical s-expression format
12352 as produced by @command{guix archive --generate-key} (@pxref{Invoking
12353 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
12354 @file{/etc/guix/signing-key.sec} are used.
12356 @item --repl[=@var{port}]
12357 @itemx -r [@var{port}]
12358 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
12359 Reference Manual}) on @var{port} (37146 by default). This is used
12360 primarily for debugging a running @command{guix publish} server.
12363 Enabling @command{guix publish} on Guix System is a one-liner: just
12364 instantiate a @code{guix-publish-service-type} service in the @code{services} field
12365 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
12366 @code{guix-publish-service-type}}).
12368 If you are instead running Guix on a ``foreign distro'', follow these
12373 If your host distro uses the systemd init system:
12376 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
12377 /etc/systemd/system/
12378 # systemctl start guix-publish && systemctl enable guix-publish
12382 If your host distro uses the Upstart init system:
12385 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
12386 # start guix-publish
12390 Otherwise, proceed similarly with your distro's init system.
12393 @node Invoking guix challenge
12394 @section Invoking @command{guix challenge}
12396 @cindex reproducible builds
12397 @cindex verifiable builds
12398 @cindex @command{guix challenge}
12400 Do the binaries provided by this server really correspond to the source
12401 code it claims to build? Is a package build process deterministic?
12402 These are the questions the @command{guix challenge} command attempts to
12405 The former is obviously an important question: Before using a substitute
12406 server (@pxref{Substitutes}), one had better @emph{verify} that it
12407 provides the right binaries, and thus @emph{challenge} it. The latter
12408 is what enables the former: If package builds are deterministic, then
12409 independent builds of the package should yield the exact same result,
12410 bit for bit; if a server provides a binary different from the one
12411 obtained locally, it may be either corrupt or malicious.
12413 We know that the hash that shows up in @file{/gnu/store} file names is
12414 the hash of all the inputs of the process that built the file or
12415 directory---compilers, libraries, build scripts,
12416 etc. (@pxref{Introduction}). Assuming deterministic build processes,
12417 one store file name should map to exactly one build output.
12418 @command{guix challenge} checks whether there is, indeed, a single
12419 mapping by comparing the build outputs of several independent builds of
12420 any given store item.
12422 The command output looks like this:
12425 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
12426 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
12427 updating list of substitutes from 'https://guix.example.org'... 100.0%
12428 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
12429 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
12430 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
12431 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
12433 /lib/libcrypto.so.1.1
12436 /gnu/store/@dots{}-git-2.5.0 contents differ:
12437 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
12438 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
12439 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
12441 /libexec/git-core/git-fsck
12443 /gnu/store/@dots{}-pius-2.1.1 contents differ:
12444 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
12445 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
12446 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
12448 /share/man/man1/pius.1.gz
12452 6,406 store items were analyzed:
12453 - 4,749 (74.1%) were identical
12454 - 525 (8.2%) differed
12455 - 1,132 (17.7%) were inconclusive
12459 In this example, @command{guix challenge} first scans the store to
12460 determine the set of locally-built derivations---as opposed to store
12461 items that were downloaded from a substitute server---and then queries
12462 all the substitute servers. It then reports those store items for which
12463 the servers obtained a result different from the local build.
12465 @cindex non-determinism, in package builds
12466 As an example, @code{guix.example.org} always gets a different answer.
12467 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
12468 case of Git. This might indicate that the build process of Git is
12469 non-deterministic, meaning that its output varies as a function of
12470 various things that Guix does not fully control, in spite of building
12471 packages in isolated environments (@pxref{Features}). Most common
12472 sources of non-determinism include the addition of timestamps in build
12473 results, the inclusion of random numbers, and directory listings sorted
12474 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
12477 To find out what is wrong with this Git binary, the easiest approach is
12481 guix challenge git \
12482 --diff=diffoscope \
12483 --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
12486 This automatically invokes @command{diffoscope}, which displays detailed
12487 information about files that differ.
12489 Alternatively, we can do something along these lines (@pxref{Invoking guix
12493 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-git-2.5.0 \
12494 | lzip -d | guix archive -x /tmp/git
12495 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
12498 This command shows the difference between the files resulting from the
12499 local build, and the files resulting from the build on
12500 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
12501 diffutils, Comparing and Merging Files}). The @command{diff} command
12502 works great for text files. When binary files differ, a better option
12503 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
12504 visualize differences for all kinds of files.
12506 Once you have done that work, you can tell whether the differences are due
12507 to a non-deterministic build process or to a malicious server. We try
12508 hard to remove sources of non-determinism in packages to make it easier
12509 to verify substitutes, but of course, this is a process that
12510 involves not just Guix, but a large part of the free software community.
12511 In the meantime, @command{guix challenge} is one tool to help address
12514 If you are writing packages for Guix, you are encouraged to check
12515 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
12516 same build result as you did with:
12519 $ guix challenge @var{package}
12523 where @var{package} is a package specification such as
12524 @code{guile@@2.0} or @code{glibc:debug}.
12526 The general syntax is:
12529 guix challenge @var{options} [@var{packages}@dots{}]
12532 When a difference is found between the hash of a locally-built item and
12533 that of a server-provided substitute, or among substitutes provided by
12534 different servers, the command displays it as in the example above and
12535 its exit code is 2 (other non-zero exit codes denote other kinds of
12538 The one option that matters is:
12542 @item --substitute-urls=@var{urls}
12543 Consider @var{urls} the whitespace-separated list of substitute source
12544 URLs to compare to.
12546 @item --diff=@var{mode}
12547 Upon mismatches, show differences according to @var{mode}, one of:
12550 @item @code{simple} (the default)
12551 Show the list of files that differ.
12553 @item @code{diffoscope}
12554 @itemx @var{command}
12555 Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
12556 two directories whose contents do not match.
12558 When @var{command} is an absolute file name, run @var{command} instead
12562 Do not show further details about the differences.
12565 Thus, unless @option{--diff=none} is passed, @command{guix challenge}
12566 downloads the store items from the given substitute servers so that it
12571 Show details about matches (identical contents) in addition to
12572 information about mismatches.
12576 @node Invoking guix copy
12577 @section Invoking @command{guix copy}
12579 @cindex copy, of store items, over SSH
12580 @cindex SSH, copy of store items
12581 @cindex sharing store items across machines
12582 @cindex transferring store items across machines
12583 The @command{guix copy} command copies items from the store of one
12584 machine to that of another machine over a secure shell (SSH)
12585 connection@footnote{This command is available only when Guile-SSH was
12586 found. @xref{Requirements}, for details.}. For example, the following
12587 command copies the @code{coreutils} package, the user's profile, and all
12588 their dependencies over to @var{host}, logged in as @var{user}:
12591 guix copy --to=@var{user}@@@var{host} \
12592 coreutils `readlink -f ~/.guix-profile`
12595 If some of the items to be copied are already present on @var{host},
12596 they are not actually sent.
12598 The command below retrieves @code{libreoffice} and @code{gimp} from
12599 @var{host}, assuming they are available there:
12602 guix copy --from=@var{host} libreoffice gimp
12605 The SSH connection is established using the Guile-SSH client, which is
12606 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
12607 @file{~/.ssh/config}, and uses the SSH agent for authentication.
12609 The key used to sign items that are sent must be accepted by the remote
12610 machine. Likewise, the key used by the remote machine to sign items you
12611 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
12612 own daemon. @xref{Invoking guix archive}, for more information about
12613 store item authentication.
12615 The general syntax is:
12618 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
12621 You must always specify one of the following options:
12624 @item --to=@var{spec}
12625 @itemx --from=@var{spec}
12626 Specify the host to send to or receive from. @var{spec} must be an SSH
12627 spec such as @code{example.org}, @code{charlie@@example.org}, or
12628 @code{charlie@@example.org:2222}.
12631 The @var{items} can be either package names, such as @code{gimp}, or
12632 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
12634 When specifying the name of a package to send, it is first built if
12635 needed, unless @option{--dry-run} was specified. Common build options
12636 are supported (@pxref{Common Build Options}).
12639 @node Invoking guix container
12640 @section Invoking @command{guix container}
12642 @cindex @command{guix container}
12644 As of version @value{VERSION}, this tool is experimental. The interface
12645 is subject to radical change in the future.
12648 The purpose of @command{guix container} is to manipulate processes
12649 running within an isolated environment, commonly known as a
12650 ``container'', typically created by the @command{guix environment}
12651 (@pxref{Invoking guix environment}) and @command{guix system container}
12652 (@pxref{Invoking guix system}) commands.
12654 The general syntax is:
12657 guix container @var{action} @var{options}@dots{}
12660 @var{action} specifies the operation to perform with a container, and
12661 @var{options} specifies the context-specific arguments for the action.
12663 The following actions are available:
12667 Execute a command within the context of a running container.
12672 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
12675 @var{pid} specifies the process ID of the running container.
12676 @var{program} specifies an executable file name within the root file
12677 system of the container. @var{arguments} are the additional options that
12678 will be passed to @var{program}.
12680 The following command launches an interactive login shell inside a
12681 Guix system container, started by @command{guix system container}, and whose
12682 process ID is 9001:
12685 guix container exec 9001 /run/current-system/profile/bin/bash --login
12688 Note that the @var{pid} cannot be the parent process of a container. It
12689 must be PID 1 of the container or one of its child processes.
12693 @node Invoking guix weather
12694 @section Invoking @command{guix weather}
12696 Occasionally you're grumpy because substitutes are lacking and you end
12697 up building packages by yourself (@pxref{Substitutes}). The
12698 @command{guix weather} command reports on substitute availability on the
12699 specified servers so you can have an idea of whether you'll be grumpy
12700 today. It can sometimes be useful info as a user, but it is primarily
12701 useful to people running @command{guix publish} (@pxref{Invoking guix
12704 @cindex statistics, for substitutes
12705 @cindex availability of substitutes
12706 @cindex substitute availability
12707 @cindex weather, substitute availability
12708 Here's a sample run:
12711 $ guix weather --substitute-urls=https://guix.example.org
12712 computing 5,872 package derivations for x86_64-linux...
12713 looking for 6,128 store items on https://guix.example.org..
12714 updating list of substitutes from 'https://guix.example.org'... 100.0%
12715 https://guix.example.org
12716 43.4% substitutes available (2,658 out of 6,128)
12717 7,032.5 MiB of nars (compressed)
12718 19,824.2 MiB on disk (uncompressed)
12719 0.030 seconds per request (182.9 seconds in total)
12720 33.5 requests per second
12722 9.8% (342 out of 3,470) of the missing items are queued
12724 x86_64-linux: 518 (59.7%)
12725 i686-linux: 221 (25.5%)
12726 aarch64-linux: 128 (14.8%)
12727 build rate: 23.41 builds per hour
12728 x86_64-linux: 11.16 builds per hour
12729 i686-linux: 6.03 builds per hour
12730 aarch64-linux: 6.41 builds per hour
12733 @cindex continuous integration, statistics
12734 As you can see, it reports the fraction of all the packages for which
12735 substitutes are available on the server---regardless of whether
12736 substitutes are enabled, and regardless of whether this server's signing
12737 key is authorized. It also reports the size of the compressed archives
12738 (``nars'') provided by the server, the size the corresponding store
12739 items occupy in the store (assuming deduplication is turned off), and
12740 the server's throughput. The second part gives continuous integration
12741 (CI) statistics, if the server supports it. In addition, using the
12742 @option{--coverage} option, @command{guix weather} can list ``important''
12743 package substitutes missing on the server (see below).
12745 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
12746 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
12747 challenge}, it ignores signatures on those substitutes, which is
12748 innocuous since the command only gathers statistics and cannot install
12751 The general syntax is:
12754 guix weather @var{options}@dots{} [@var{packages}@dots{}]
12757 When @var{packages} is omitted, @command{guix weather} checks the availability
12758 of substitutes for @emph{all} the packages, or for those specified with
12759 @option{--manifest}; otherwise it only considers the specified packages. It
12760 is also possible to query specific system types with @option{--system}.
12761 @command{guix weather} exits with a non-zero code when the fraction of
12762 available substitutes is below 100%.
12764 The available options are listed below.
12767 @item --substitute-urls=@var{urls}
12768 @var{urls} is the space-separated list of substitute server URLs to
12769 query. When this option is omitted, the default set of substitute
12770 servers is queried.
12772 @item --system=@var{system}
12773 @itemx -s @var{system}
12774 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
12775 option can be repeated, in which case @command{guix weather} will query
12776 substitutes for several system types.
12778 @item --manifest=@var{file}
12779 Instead of querying substitutes for all the packages, only ask for those
12780 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
12781 with the @code{-m} option of @command{guix package} (@pxref{Invoking
12784 This option can be repeated several times, in which case the manifests
12787 @item --coverage[=@var{count}]
12788 @itemx -c [@var{count}]
12789 Report on substitute coverage for packages: list packages with at least
12790 @var{count} dependents (zero by default) for which substitutes are
12791 unavailable. Dependent packages themselves are not listed: if @var{b} depends
12792 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
12793 @var{b} usually lacks substitutes as well. The result looks like this:
12796 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
12797 computing 8,983 package derivations for x86_64-linux...
12798 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
12799 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
12800 @value{SUBSTITUTE-URL}
12801 64.7% substitutes available (6,047 out of 9,343)
12803 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
12804 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
12805 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
12806 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
12810 What this example shows is that @code{kcoreaddons} and presumably the 58
12811 packages that depend on it have no substitutes at @code{ci.guix.info};
12812 likewise for @code{qgpgme} and the 46 packages that depend on it.
12814 If you are a Guix developer, or if you are taking care of this build farm,
12815 you'll probably want to have a closer look at these packages: they may simply
12818 @item --display-missing
12819 Display the list of store items for which substitutes are missing.
12822 @node Invoking guix processes
12823 @section Invoking @command{guix processes}
12825 The @command{guix processes} command can be useful to developers and system
12826 administrators, especially on multi-user machines and on build farms: it lists
12827 the current sessions (connections to the daemon), as well as information about
12828 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
12829 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
12830 listed.}. Here's an example of the information it returns:
12833 $ sudo guix processes
12836 ClientCommand: guix environment --ad-hoc python
12840 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
12844 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
12845 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
12846 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
12847 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
12848 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
12849 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
12850 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
12853 In this example we see that @command{guix-daemon} has three clients:
12854 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
12855 integration tool; their process identifier (PID) is given by the
12856 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
12857 @command{guix-daemon} sub-process of this particular session.
12859 The @code{LockHeld} fields show which store items are currently locked by this
12860 session, which corresponds to store items being built or substituted (the
12861 @code{LockHeld} field is not displayed when @command{guix processes} is not
12862 running as root). Last, by looking at the @code{ChildProcess} field, we
12863 understand that these three builds are being offloaded (@pxref{Daemon Offload
12866 The output is in Recutils format so we can use the handy @command{recsel}
12867 command to select sessions of interest (@pxref{Selection Expressions,,,
12868 recutils, GNU recutils manual}). As an example, the command shows the command
12869 line and PID of the client that triggered the build of a Perl package:
12872 $ sudo guix processes | \
12873 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
12875 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
12878 @node System Configuration
12879 @chapter System Configuration
12881 @cindex system configuration
12882 Guix System supports a consistent whole-system configuration
12883 mechanism. By that we mean that all aspects of the global system
12884 configuration---such as the available system services, timezone and
12885 locale settings, user accounts---are declared in a single place. Such
12886 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
12888 One of the advantages of putting all the system configuration under the
12889 control of Guix is that it supports transactional system upgrades, and
12890 makes it possible to roll back to a previous system instantiation,
12891 should something go wrong with the new one (@pxref{Features}). Another
12892 advantage is that it makes it easy to replicate the exact same configuration
12893 across different machines, or at different points in time, without
12894 having to resort to additional administration tools layered on top of
12895 the own tools of the system.
12896 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
12898 This section describes this mechanism. First we focus on the system
12899 administrator's viewpoint---explaining how the system is configured and
12900 instantiated. Then we show how this mechanism can be extended, for
12901 instance to support new system services.
12904 * Using the Configuration System:: Customizing your GNU system.
12905 * operating-system Reference:: Detail of operating-system declarations.
12906 * File Systems:: Configuring file system mounts.
12907 * Mapped Devices:: Block device extra processing.
12908 * User Accounts:: Specifying user accounts.
12909 * Keyboard Layout:: How the system interprets key strokes.
12910 * Locales:: Language and cultural convention settings.
12911 * Services:: Specifying system services.
12912 * Setuid Programs:: Programs running with root privileges.
12913 * X.509 Certificates:: Authenticating HTTPS servers.
12914 * Name Service Switch:: Configuring libc's name service switch.
12915 * Initial RAM Disk:: Linux-Libre bootstrapping.
12916 * Bootloader Configuration:: Configuring the boot loader.
12917 * Invoking guix system:: Instantiating a system configuration.
12918 * Invoking guix deploy:: Deploying a system configuration to a remote host.
12919 * Running Guix in a VM:: How to run Guix System in a virtual machine.
12920 * Defining Services:: Adding new service definitions.
12923 @node Using the Configuration System
12924 @section Using the Configuration System
12926 The operating system is configured by providing an
12927 @code{operating-system} declaration in a file that can then be passed to
12928 the @command{guix system} command (@pxref{Invoking guix system}). A
12929 simple setup, with the default system services, the default Linux-Libre
12930 kernel, initial RAM disk, and boot loader looks like this:
12932 @findex operating-system
12934 @include os-config-bare-bones.texi
12937 This example should be self-describing. Some of the fields defined
12938 above, such as @code{host-name} and @code{bootloader}, are mandatory.
12939 Others, such as @code{packages} and @code{services}, can be omitted, in
12940 which case they get a default value.
12942 Below we discuss the effect of some of the most important fields
12943 (@pxref{operating-system Reference}, for details about all the available
12944 fields), and how to @dfn{instantiate} the operating system using
12945 @command{guix system}.
12947 @unnumberedsubsec Bootloader
12949 @cindex legacy boot, on Intel machines
12950 @cindex BIOS boot, on Intel machines
12953 The @code{bootloader} field describes the method that will be used to boot
12954 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
12955 mode, as in the example above. However, more recent machines rely instead on
12956 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
12957 the @code{bootloader} field should contain something along these lines:
12960 (bootloader-configuration
12961 (bootloader grub-efi-bootloader)
12962 (target "/boot/efi"))
12965 @xref{Bootloader Configuration}, for more information on the available
12966 configuration options.
12968 @unnumberedsubsec Globally-Visible Packages
12970 @vindex %base-packages
12971 The @code{packages} field lists packages that will be globally visible
12972 on the system, for all user accounts---i.e., in every user's @env{PATH}
12973 environment variable---in addition to the per-user profiles
12974 (@pxref{Invoking guix package}). The @code{%base-packages} variable
12975 provides all the tools one would expect for basic user and administrator
12976 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
12977 the GNU Zile lightweight text editor, @command{find}, @command{grep},
12978 etc. The example above adds GNU@tie{}Screen to those,
12979 taken from the @code{(gnu packages screen)}
12980 module (@pxref{Package Modules}). The
12981 @code{(list package output)} syntax can be used to add a specific output
12985 (use-modules (gnu packages))
12986 (use-modules (gnu packages dns))
12990 (packages (cons (list bind "utils")
12994 @findex specification->package
12995 Referring to packages by variable name, like @code{bind} above, has
12996 the advantage of being unambiguous; it also allows typos and such to be
12997 diagnosed right away as ``unbound variables''. The downside is that one
12998 needs to know which module defines which package, and to augment the
12999 @code{use-package-modules} line accordingly. To avoid that, one can use
13000 the @code{specification->package} procedure of the @code{(gnu packages)}
13001 module, which returns the best package for a given name or name and
13005 (use-modules (gnu packages))
13009 (packages (append (map specification->package
13010 '("tcpdump" "htop" "gnupg@@2.0"))
13014 @unnumberedsubsec System Services
13017 @vindex %base-services
13018 The @code{services} field lists @dfn{system services} to be made
13019 available when the system starts (@pxref{Services}).
13020 The @code{operating-system} declaration above specifies that, in
13021 addition to the basic services, we want the OpenSSH secure shell
13022 daemon listening on port 2222 (@pxref{Networking Services,
13023 @code{openssh-service-type}}). Under the hood,
13024 @code{openssh-service-type} arranges so that @command{sshd} is started with the
13025 right command-line options, possibly with supporting configuration files
13026 generated as needed (@pxref{Defining Services}).
13028 @cindex customization, of services
13029 @findex modify-services
13030 Occasionally, instead of using the base services as is, you will want to
13031 customize them. To do this, use @code{modify-services} (@pxref{Service
13032 Reference, @code{modify-services}}) to modify the list.
13034 For example, suppose you want to modify @code{guix-daemon} and Mingetty
13035 (the console log-in) in the @code{%base-services} list (@pxref{Base
13036 Services, @code{%base-services}}). To do that, you can write the
13037 following in your operating system declaration:
13040 (define %my-services
13041 ;; My very own list of services.
13042 (modify-services %base-services
13043 (guix-service-type config =>
13044 (guix-configuration
13046 ;; Fetch substitutes from example.org.
13048 (list "https://example.org/guix"
13049 "https://ci.guix.gnu.org"))))
13050 (mingetty-service-type config =>
13051 (mingetty-configuration
13053 ;; Automatially log in as "guest".
13054 (auto-login "guest")))))
13058 (services %my-services))
13061 This changes the configuration---i.e., the service parameters---of the
13062 @code{guix-service-type} instance, and that of all the
13063 @code{mingetty-service-type} instances in the @code{%base-services} list.
13064 Observe how this is accomplished: first, we arrange for the original
13065 configuration to be bound to the identifier @code{config} in the
13066 @var{body}, and then we write the @var{body} so that it evaluates to the
13067 desired configuration. In particular, notice how we use @code{inherit}
13068 to create a new configuration which has the same values as the old
13069 configuration, but with a few modifications.
13071 @cindex encrypted disk
13072 The configuration for a typical ``desktop'' usage, with an encrypted
13073 root partition, the X11 display
13074 server, GNOME and Xfce (users can choose which of these desktop
13075 environments to use at the log-in screen by pressing @kbd{F1}), network
13076 management, power management, and more, would look like this:
13079 @include os-config-desktop.texi
13082 A graphical system with a choice of lightweight window managers
13083 instead of full-blown desktop environments would look like this:
13086 @include os-config-lightweight-desktop.texi
13089 This example refers to the @file{/boot/efi} file system by its UUID,
13090 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
13091 as returned by the @command{blkid} command.
13093 @xref{Desktop Services}, for the exact list of services provided by
13094 @code{%desktop-services}. @xref{X.509 Certificates}, for background
13095 information about the @code{nss-certs} package that is used here.
13097 Again, @code{%desktop-services} is just a list of service objects. If
13098 you want to remove services from there, you can do so using the
13099 procedures for list filtering (@pxref{SRFI-1 Filtering and
13100 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
13101 following expression returns a list that contains all the services in
13102 @code{%desktop-services} minus the Avahi service:
13105 (remove (lambda (service)
13106 (eq? (service-kind service) avahi-service-type))
13110 @unnumberedsubsec Instantiating the System
13112 Assuming the @code{operating-system} declaration
13113 is stored in the @file{my-system-config.scm}
13114 file, the @command{guix system reconfigure my-system-config.scm} command
13115 instantiates that configuration, and makes it the default GRUB boot
13116 entry (@pxref{Invoking guix system}).
13118 The normal way to change the system configuration is by updating this
13119 file and re-running @command{guix system reconfigure}. One should never
13120 have to touch files in @file{/etc} or to run commands that modify the
13121 system state such as @command{useradd} or @command{grub-install}. In
13122 fact, you must avoid that since that would not only void your warranty
13123 but also prevent you from rolling back to previous versions of your
13124 system, should you ever need to.
13126 @cindex roll-back, of the operating system
13127 Speaking of roll-back, each time you run @command{guix system
13128 reconfigure}, a new @dfn{generation} of the system is created---without
13129 modifying or deleting previous generations. Old system generations get
13130 an entry in the bootloader boot menu, allowing you to boot them in case
13131 something went wrong with the latest generation. Reassuring, no? The
13132 @command{guix system list-generations} command lists the system
13133 generations available on disk. It is also possible to roll back the
13134 system via the commands @command{guix system roll-back} and
13135 @command{guix system switch-generation}.
13137 Although the @command{guix system reconfigure} command will not modify
13138 previous generations, you must take care when the current generation is not
13139 the latest (e.g., after invoking @command{guix system roll-back}), since
13140 the operation might overwrite a later generation (@pxref{Invoking guix
13143 @unnumberedsubsec The Programming Interface
13145 At the Scheme level, the bulk of an @code{operating-system} declaration
13146 is instantiated with the following monadic procedure (@pxref{The Store
13149 @deffn {Monadic Procedure} operating-system-derivation os
13150 Return a derivation that builds @var{os}, an @code{operating-system}
13151 object (@pxref{Derivations}).
13153 The output of the derivation is a single directory that refers to all
13154 the packages, configuration files, and other supporting files needed to
13155 instantiate @var{os}.
13158 This procedure is provided by the @code{(gnu system)} module. Along
13159 with @code{(gnu services)} (@pxref{Services}), this module contains the
13160 guts of Guix System. Make sure to visit it!
13163 @node operating-system Reference
13164 @section @code{operating-system} Reference
13166 This section summarizes all the options available in
13167 @code{operating-system} declarations (@pxref{Using the Configuration
13170 @deftp {Data Type} operating-system
13171 This is the data type representing an operating system configuration.
13172 By that, we mean all the global system configuration, not per-user
13173 configuration (@pxref{Using the Configuration System}).
13176 @item @code{kernel} (default: @code{linux-libre})
13177 The package object of the operating system kernel to
13178 use@footnote{Currently only the Linux-libre kernel is fully supported.
13179 Using GNU@tie{}mach with the GNU@tie{}Hurd is experimental and only
13180 available when building a virtual machine disk image.}.
13183 @item @code{hurd} (default: @code{#f})
13184 The package object of the Hurd to be started by the kernel. When this
13185 field is set, produce a GNU/Hurd operating system. In that case,
13186 @code{kernel} must also be set to the @code{gnumach} package---the
13187 microkernel the Hurd runs on.
13190 This feature is experimental and only supported for disk images.
13193 @item @code{kernel-loadable-modules} (default: '())
13194 A list of objects (usually packages) to collect loadable kernel modules
13195 from--e.g. @code{(list ddcci-driver-linux)}.
13197 @item @code{kernel-arguments} (default: @code{%default-kernel-arguments})
13198 List of strings or gexps representing additional arguments to pass on
13199 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
13201 @item @code{bootloader}
13202 The system bootloader configuration object. @xref{Bootloader Configuration}.
13205 This is the label (a string) as it appears in the bootloader's menu entry.
13206 The default label includes the kernel name and version.
13208 @item @code{keyboard-layout} (default: @code{#f})
13209 This field specifies the keyboard layout to use in the console. It can be
13210 either @code{#f}, in which case the default keyboard layout is used (usually
13211 US English), or a @code{<keyboard-layout>} record.
13213 This keyboard layout is in effect as soon as the kernel has booted. For
13214 instance, it is the keyboard layout in effect when you type a passphrase if
13215 your root file system is on a @code{luks-device-mapping} mapped device
13216 (@pxref{Mapped Devices}).
13219 This does @emph{not} specify the keyboard layout used by the bootloader, nor
13220 that used by the graphical display server. @xref{Bootloader Configuration},
13221 for information on how to specify the bootloader's keyboard layout. @xref{X
13222 Window}, for information on how to specify the keyboard layout used by the X
13226 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
13228 @cindex initial RAM disk
13229 The list of Linux kernel modules that need to be available in the
13230 initial RAM disk. @xref{Initial RAM Disk}.
13232 @item @code{initrd} (default: @code{base-initrd})
13233 A procedure that returns an initial RAM disk for the Linux
13234 kernel. This field is provided to support low-level customization and
13235 should rarely be needed for casual use. @xref{Initial RAM Disk}.
13237 @item @code{firmware} (default: @code{%base-firmware})
13239 List of firmware packages loadable by the operating system kernel.
13241 The default includes firmware needed for Atheros- and Broadcom-based
13242 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
13243 respectively). @xref{Hardware Considerations}, for more info on
13244 supported hardware.
13246 @item @code{host-name}
13249 @item @code{hosts-file}
13251 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
13252 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
13253 Reference Manual}). The default is a file with entries for
13254 @code{localhost} and @var{host-name}.
13256 @item @code{mapped-devices} (default: @code{'()})
13257 A list of mapped devices. @xref{Mapped Devices}.
13259 @item @code{file-systems}
13260 A list of file systems. @xref{File Systems}.
13262 @cindex swap devices
13264 @item @code{swap-devices} (default: @code{'()})
13265 A list of UUIDs, file system labels, or strings identifying devices or
13266 files to be used for ``swap
13267 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
13268 Manual}). Here are some examples:
13271 @item (list (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb"))
13272 Use the swap partition with the given UUID. You can learn the UUID of a
13273 Linux swap partition by running @command{swaplabel @var{device}}, where
13274 @var{device} is the @file{/dev} file name of that partition.
13276 @item (list (file-system-label "swap"))
13277 Use the partition with label @code{swap}. Again, the
13278 @command{swaplabel} command allows you to view and change the label of a
13279 Linux swap partition.
13281 @item (list "/swapfile")
13282 Use the file @file{/swapfile} as swap space.
13284 @item (list "/dev/sda3" "/dev/sdb2")
13285 Use the @file{/dev/sda3} and @file{/dev/sdb2} partitions as swap space.
13286 We recommend referring to swap devices by UUIDs or labels as shown above
13290 It is possible to specify a swap file in a file system on a mapped
13291 device (under @file{/dev/mapper}), provided that the necessary device
13292 mapping and file system are also specified. @xref{Mapped Devices} and
13293 @ref{File Systems}.
13295 @item @code{users} (default: @code{%base-user-accounts})
13296 @itemx @code{groups} (default: @code{%base-groups})
13297 List of user accounts and groups. @xref{User Accounts}.
13299 If the @code{users} list lacks a user account with UID@tie{}0, a
13300 ``root'' account with UID@tie{}0 is automatically added.
13302 @item @code{skeletons} (default: @code{(default-skeletons)})
13303 A list of target file name/file-like object tuples (@pxref{G-Expressions,
13304 file-like objects}). These are the skeleton files that will be added to
13305 the home directory of newly-created user accounts.
13307 For instance, a valid value may look like this:
13310 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
13311 (".guile" ,(plain-file "guile"
13312 "(use-modules (ice-9 readline))
13313 (activate-readline)")))
13316 @item @code{issue} (default: @code{%default-issue})
13317 A string denoting the contents of the @file{/etc/issue} file, which is
13318 displayed when users log in on a text console.
13320 @item @code{packages} (default: @code{%base-packages})
13321 A list of packages to be installed in the global profile, which is accessible
13322 at @file{/run/current-system/profile}. Each element is either a package
13323 variable or a package/output tuple. Here's a simple example of both:
13326 (cons* git ; the default "out" output
13327 (list git "send-email") ; another output of git
13328 %base-packages) ; the default set
13331 The default set includes core utilities and it is good practice to
13332 install non-core utilities in user profiles (@pxref{Invoking guix
13335 @item @code{timezone}
13336 A timezone identifying string---e.g., @code{"Europe/Paris"}.
13338 You can run the @command{tzselect} command to find out which timezone
13339 string corresponds to your region. Choosing an invalid timezone name
13340 causes @command{guix system} to fail.
13342 @item @code{locale} (default: @code{"en_US.utf8"})
13343 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
13344 Library Reference Manual}). @xref{Locales}, for more information.
13346 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
13347 The list of locale definitions to be compiled and that may be used at
13348 run time. @xref{Locales}.
13350 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
13351 The list of GNU@tie{}libc packages whose locale data and tools are used
13352 to build the locale definitions. @xref{Locales}, for compatibility
13353 considerations that justify this option.
13355 @item @code{name-service-switch} (default: @code{%default-nss})
13356 Configuration of the libc name service switch (NSS)---a
13357 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
13360 @item @code{services} (default: @code{%base-services})
13361 A list of service objects denoting system services. @xref{Services}.
13363 @cindex essential services
13364 @item @code{essential-services} (default: ...)
13365 The list of ``essential services''---i.e., things like instances of
13366 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
13367 Reference}), which are derived from the operating system definition itself.
13368 As a user you should @emph{never} need to touch this field.
13370 @item @code{pam-services} (default: @code{(base-pam-services)})
13372 @cindex pluggable authentication modules
13373 Linux @dfn{pluggable authentication module} (PAM) services.
13374 @c FIXME: Add xref to PAM services section.
13376 @item @code{setuid-programs} (default: @code{%setuid-programs})
13377 List of string-valued G-expressions denoting setuid programs.
13378 @xref{Setuid Programs}.
13380 @item @code{sudoers-file} (default: @code{%sudoers-specification})
13381 @cindex sudoers file
13382 The contents of the @file{/etc/sudoers} file as a file-like object
13383 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
13385 This file specifies which users can use the @command{sudo} command, what
13386 they are allowed to do, and what privileges they may gain. The default
13387 is that only @code{root} and members of the @code{wheel} group may use
13392 @deffn {Scheme Syntax} this-operating-system
13393 When used in the @emph{lexical scope} of an operating system field definition,
13394 this identifier resolves to the operating system being defined.
13396 The example below shows how to refer to the operating system being defined in
13397 the definition of the @code{label} field:
13400 (use-modules (gnu) (guix))
13404 (label (package-full-name
13405 (operating-system-kernel this-operating-system))))
13408 It is an error to refer to @code{this-operating-system} outside an operating
13415 @section File Systems
13417 The list of file systems to be mounted is specified in the
13418 @code{file-systems} field of the operating system declaration
13419 (@pxref{Using the Configuration System}). Each file system is declared
13420 using the @code{file-system} form, like this:
13424 (mount-point "/home")
13425 (device "/dev/sda3")
13429 As usual, some of the fields are mandatory---those shown in the example
13430 above---while others can be omitted. These are described below.
13432 @deftp {Data Type} file-system
13433 Objects of this type represent file systems to be mounted. They
13434 contain the following members:
13438 This is a string specifying the type of the file system---e.g.,
13441 @item @code{mount-point}
13442 This designates the place where the file system is to be mounted.
13444 @item @code{device}
13445 This names the ``source'' of the file system. It can be one of three
13446 things: a file system label, a file system UUID, or the name of a
13447 @file{/dev} node. Labels and UUIDs offer a way to refer to file
13448 systems without having to hard-code their actual device
13449 name@footnote{Note that, while it is tempting to use
13450 @file{/dev/disk/by-uuid} and similar device names to achieve the same
13451 result, this is not recommended: These special device nodes are created
13452 by the udev daemon and may be unavailable at the time the device is
13455 @findex file-system-label
13456 File system labels are created using the @code{file-system-label}
13457 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
13458 plain strings. Here's an example of a file system referred to by its
13459 label, as shown by the @command{e2label} command:
13463 (mount-point "/home")
13465 (device (file-system-label "my-home")))
13469 UUIDs are converted from their string representation (as shown by the
13470 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
13471 @code{uuid} form expects 16-byte UUIDs as defined in
13472 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
13473 form of UUID used by the ext2 family of file systems and others, but it
13474 is different from ``UUIDs'' found in FAT file systems, for instance.},
13479 (mount-point "/home")
13481 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
13484 When the source of a file system is a mapped device (@pxref{Mapped
13485 Devices}), its @code{device} field @emph{must} refer to the mapped
13486 device name---e.g., @file{"/dev/mapper/root-partition"}.
13487 This is required so that
13488 the system knows that mounting the file system depends on having the
13489 corresponding device mapping established.
13491 @item @code{flags} (default: @code{'()})
13492 This is a list of symbols denoting mount flags. Recognized flags
13493 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
13494 access to special files), @code{no-suid} (ignore setuid and setgid
13495 bits), @code{no-atime} (do not update file access times),
13496 @code{strict-atime} (update file access time), @code{lazy-time} (only
13497 update time on the in-memory version of the file inode), and
13498 @code{no-exec} (disallow program execution).
13499 @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
13500 Manual}, for more information on these flags.
13502 @item @code{options} (default: @code{#f})
13503 This is either @code{#f}, or a string denoting mount options passed to
13504 the file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C
13505 Library Reference Manual}, for details and run @command{man 8 mount} for
13506 options for various file systems. Note that the
13507 @code{file-system-options->alist} and @code{alist->file-system-options}
13508 procedures from @code{(gnu system file-systems)} can be used to convert
13509 file system options given as an association list to the string
13510 representation, and vice-versa.
13512 @item @code{mount?} (default: @code{#t})
13513 This value indicates whether to automatically mount the file system when
13514 the system is brought up. When set to @code{#f}, the file system gets
13515 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
13516 is not automatically mounted.
13518 @item @code{needed-for-boot?} (default: @code{#f})
13519 This Boolean value indicates whether the file system is needed when
13520 booting. If that is true, then the file system is mounted when the
13521 initial RAM disk (initrd) is loaded. This is always the case, for
13522 instance, for the root file system.
13524 @item @code{check?} (default: @code{#t})
13525 This Boolean indicates whether the file system needs to be checked for
13526 errors before being mounted.
13528 @item @code{create-mount-point?} (default: @code{#f})
13529 When true, the mount point is created if it does not exist yet.
13531 @item @code{mount-may-fail?} (default: @code{#f})
13532 When true, this indicates that mounting this file system can fail but
13533 that should not be considered an error. This is useful in unusual
13534 cases; an example of this is @code{efivarfs}, a file system that can
13535 only be mounted on EFI/UEFI systems.
13537 @item @code{dependencies} (default: @code{'()})
13538 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
13539 representing file systems that must be mounted or mapped devices that
13540 must be opened before (and unmounted or closed after) this one.
13542 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
13543 a dependency of @file{/sys/fs/cgroup/cpu} and
13544 @file{/sys/fs/cgroup/memory}.
13546 Another example is a file system that depends on a mapped device, for
13547 example for an encrypted partition (@pxref{Mapped Devices}).
13551 @deffn {Scheme Procedure} file-system-label @var{str}
13552 This procedure returns an opaque file system label from @var{str}, a
13556 (file-system-label "home")
13557 @result{} #<file-system-label "home">
13560 File system labels are used to refer to file systems by label rather
13561 than by device name. See above for examples.
13564 The @code{(gnu system file-systems)} exports the following useful
13567 @defvr {Scheme Variable} %base-file-systems
13568 These are essential file systems that are required on normal systems,
13569 such as @code{%pseudo-terminal-file-system} and @code{%immutable-store} (see
13570 below). Operating system declarations should always contain at least
13574 @defvr {Scheme Variable} %pseudo-terminal-file-system
13575 This is the file system to be mounted as @file{/dev/pts}. It supports
13576 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
13577 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
13578 Manual}). Pseudo-terminals are used by terminal emulators such as
13582 @defvr {Scheme Variable} %shared-memory-file-system
13583 This file system is mounted as @file{/dev/shm} and is used to support
13584 memory sharing across processes (@pxref{Memory-mapped I/O,
13585 @code{shm_open},, libc, The GNU C Library Reference Manual}).
13588 @defvr {Scheme Variable} %immutable-store
13589 This file system performs a read-only ``bind mount'' of
13590 @file{/gnu/store}, making it read-only for all the users including
13591 @code{root}. This prevents against accidental modification by software
13592 running as @code{root} or by system administrators.
13594 The daemon itself is still able to write to the store: it remounts it
13595 read-write in its own ``name space.''
13598 @defvr {Scheme Variable} %binary-format-file-system
13599 The @code{binfmt_misc} file system, which allows handling of arbitrary
13600 executable file types to be delegated to user space. This requires the
13601 @code{binfmt.ko} kernel module to be loaded.
13604 @defvr {Scheme Variable} %fuse-control-file-system
13605 The @code{fusectl} file system, which allows unprivileged users to mount
13606 and unmount user-space FUSE file systems. This requires the
13607 @code{fuse.ko} kernel module to be loaded.
13610 The @code{(gnu system uuid)} module provides tools to deal with file
13611 system ``unique identifiers'' (UUIDs).
13613 @deffn {Scheme Procedure} uuid @var{str} [@var{type}]
13614 Return an opaque UUID (unique identifier) object of the given @var{type}
13615 (a symbol) by parsing @var{str} (a string):
13618 (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")
13619 @result{} #<<uuid> type: dce bv: @dots{}>
13621 (uuid "1234-ABCD" 'fat)
13622 @result{} #<<uuid> type: fat bv: @dots{}>
13625 @var{type} may be one of @code{dce}, @code{iso9660}, @code{fat},
13626 @code{ntfs}, or one of the commonly found synonyms for these.
13628 UUIDs are another way to unambiguously refer to file systems in
13629 operating system configuration. See the examples above.
13633 @node Btrfs file system
13634 @subsection Btrfs file system
13636 The Btrfs has special features, such as subvolumes, that merit being
13637 explained in more details. The following section attempts to cover
13638 basic as well as complex uses of a Btrfs file system with the Guix
13641 In its simplest usage, a Btrfs file system can be described, for
13646 (mount-point "/home")
13648 (device (file-system-label "my-home")))
13651 The example below is more complex, as it makes use of a Btrfs
13652 subvolume, named @code{rootfs}. The parent Btrfs file system is labeled
13653 @code{my-btrfs-pool}, and is located on an encrypted device (hence the
13654 dependency on @code{mapped-devices}):
13658 (device (file-system-label "my-btrfs-pool"))
13661 (options "subvol=rootfs")
13662 (dependencies mapped-devices))
13665 Some bootloaders, for example GRUB, only mount a Btrfs partition at its
13666 top level during the early boot, and rely on their configuration to
13667 refer to the correct subvolume path within that top level. The
13668 bootloaders operating in this way typically produce their configuration
13669 on a running system where the Btrfs partitions are already mounted and
13670 where the subvolume information is readily available. As an example,
13671 @command{grub-mkconfig}, the configuration generator command shipped
13672 with GRUB, reads @file{/proc/self/mountinfo} to determine the top-level
13673 path of a subvolume.
13675 The Guix System produces a bootloader configuration using the operating
13676 system configuration as its sole input; it is therefore necessary to
13677 extract the subvolume name on which @file{/gnu/store} lives (if any)
13678 from that operating system configuration. To better illustrate,
13679 consider a subvolume named 'rootfs' which contains the root file system
13680 data. In such situation, the GRUB bootloader would only see the top
13681 level of the root Btrfs partition, e.g.:
13685 ├── rootfs (subvolume directory)
13686 ├── gnu (normal directory)
13687 ├── store (normal directory)
13691 Thus, the subvolume name must be prepended to the @file{/gnu/store} path
13692 of the kernel, initrd binaries and any other files referred to in the
13693 GRUB configuration that must be found during the early boot.
13695 The next example shows a nested hierarchy of subvolumes and
13700 ├── rootfs (subvolume)
13701 ├── gnu (normal directory)
13702 ├── store (subvolume)
13706 This scenario would work without mounting the 'store' subvolume.
13707 Mounting 'rootfs' is sufficient, since the subvolume name matches its
13708 intended mount point in the file system hierarchy. Alternatively, the
13709 'store' subvolume could be referred to by setting the @code{subvol}
13710 option to either @code{/rootfs/gnu/store} or @code{rootfs/gnu/store}.
13712 Finally, a more contrived example of nested subvolumes:
13716 ├── root-snapshots (subvolume)
13717 ├── root-current (subvolume)
13718 ├── guix-store (subvolume)
13722 Here, the 'guix-store' subvolume doesn't match its intended mount point,
13723 so it is necessary to mount it. The subvolume must be fully specified,
13724 by passing its file name to the @code{subvol} option. To illustrate,
13725 the 'guix-store' subvolume could be mounted on @file{/gnu/store} by using
13726 a file system declaration such as:
13730 (device (file-system-label "btrfs-pool-1"))
13731 (mount-point "/gnu/store")
13733 (options "subvol=root-snapshots/root-current/guix-store,\
13734 compress-force=zstd,space_cache=v2"))
13737 @node Mapped Devices
13738 @section Mapped Devices
13740 @cindex device mapping
13741 @cindex mapped devices
13742 The Linux kernel has a notion of @dfn{device mapping}: a block device,
13743 such as a hard disk partition, can be @dfn{mapped} into another device,
13744 usually in @code{/dev/mapper/},
13745 with additional processing over the data that flows through
13746 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
13747 concept of a ``mapped device'' and that of a file system: both boil down
13748 to @emph{translating} input/output operations made on a file to
13749 operations on its backing store. Thus, the Hurd implements mapped
13750 devices, like file systems, using the generic @dfn{translator} mechanism
13751 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
13752 typical example is encryption device mapping: all writes to the mapped
13753 device are encrypted, and all reads are deciphered, transparently.
13754 Guix extends this notion by considering any device or set of devices that
13755 are @dfn{transformed} in some way to create a new device; for instance,
13756 RAID devices are obtained by @dfn{assembling} several other devices, such
13757 as hard disks or partitions, into a new one that behaves as one partition.
13758 Other examples, not yet implemented, are LVM logical volumes.
13760 Mapped devices are declared using the @code{mapped-device} form,
13761 defined as follows; for examples, see below.
13763 @deftp {Data Type} mapped-device
13764 Objects of this type represent device mappings that will be made when
13765 the system boots up.
13769 This is either a string specifying the name of the block device to be mapped,
13770 such as @code{"/dev/sda3"}, or a list of such strings when several devices
13771 need to be assembled for creating a new one.
13774 This string specifies the name of the resulting mapped device. For
13775 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
13776 specifying @code{"my-partition"} leads to the creation of
13777 the @code{"/dev/mapper/my-partition"} device.
13778 For RAID devices of type @code{raid-device-mapping}, the full device name
13779 such as @code{"/dev/md0"} needs to be given.
13782 This must be a @code{mapped-device-kind} object, which specifies how
13783 @var{source} is mapped to @var{target}.
13787 @defvr {Scheme Variable} luks-device-mapping
13788 This defines LUKS block device encryption using the @command{cryptsetup}
13789 command from the package with the same name. It relies on the
13790 @code{dm-crypt} Linux kernel module.
13793 @defvr {Scheme Variable} raid-device-mapping
13794 This defines a RAID device, which is assembled using the @code{mdadm}
13795 command from the package with the same name. It requires a Linux kernel
13796 module for the appropriate RAID level to be loaded, such as @code{raid456}
13797 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
13800 @cindex disk encryption
13802 The following example specifies a mapping from @file{/dev/sda3} to
13803 @file{/dev/mapper/home} using LUKS---the
13804 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
13805 standard mechanism for disk encryption.
13806 The @file{/dev/mapper/home}
13807 device can then be used as the @code{device} of a @code{file-system}
13808 declaration (@pxref{File Systems}).
13812 (source "/dev/sda3")
13814 (type luks-device-mapping))
13817 Alternatively, to become independent of device numbering, one may obtain
13818 the LUKS UUID (@dfn{unique identifier}) of the source device by a
13822 cryptsetup luksUUID /dev/sda3
13825 and use it as follows:
13829 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
13831 (type luks-device-mapping))
13834 @cindex swap encryption
13835 It is also desirable to encrypt swap space, since swap space may contain
13836 sensitive data. One way to accomplish that is to use a swap file in a
13837 file system on a device mapped via LUKS encryption. In this way, the
13838 swap file is encrypted because the entire device is encrypted.
13839 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
13841 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
13842 may be declared as follows:
13846 (source (list "/dev/sda1" "/dev/sdb1"))
13847 (target "/dev/md0")
13848 (type raid-device-mapping))
13851 The @file{/dev/md0} device can then be used as the @code{device} of a
13852 @code{file-system} declaration (@pxref{File Systems}).
13853 Note that the RAID level need not be given; it is chosen during the
13854 initial creation and formatting of the RAID device and is determined
13855 automatically later.
13858 @node User Accounts
13859 @section User Accounts
13863 @cindex user accounts
13864 User accounts and groups are entirely managed through the
13865 @code{operating-system} declaration. They are specified with the
13866 @code{user-account} and @code{user-group} forms:
13872 (supplementary-groups '("wheel" ;allow use of sudo, etc.
13873 "audio" ;sound card
13874 "video" ;video devices such as webcams
13875 "cdrom")) ;the good ol' CD-ROM
13876 (comment "Bob's sister"))
13879 Here's a user account that uses a different shell and a custom home
13880 directory (the default would be @file{"/home/bob"}):
13886 (comment "Alice's bro")
13887 (shell (file-append zsh "/bin/zsh"))
13888 (home-directory "/home/robert"))
13891 When booting or upon completion of @command{guix system reconfigure},
13892 the system ensures that only the user accounts and groups specified in
13893 the @code{operating-system} declaration exist, and with the specified
13894 properties. Thus, account or group creations or modifications made by
13895 directly invoking commands such as @command{useradd} are lost upon
13896 reconfiguration or reboot. This ensures that the system remains exactly
13899 @deftp {Data Type} user-account
13900 Objects of this type represent user accounts. The following members may
13905 The name of the user account.
13909 This is the name (a string) or identifier (a number) of the user group
13910 this account belongs to.
13912 @item @code{supplementary-groups} (default: @code{'()})
13913 Optionally, this can be defined as a list of group names that this
13914 account belongs to.
13916 @item @code{uid} (default: @code{#f})
13917 This is the user ID for this account (a number), or @code{#f}. In the
13918 latter case, a number is automatically chosen by the system when the
13919 account is created.
13921 @item @code{comment} (default: @code{""})
13922 A comment about the account, such as the account owner's full name.
13924 @item @code{home-directory}
13925 This is the name of the home directory for the account.
13927 @item @code{create-home-directory?} (default: @code{#t})
13928 Indicates whether the home directory of this account should be created
13929 if it does not exist yet.
13931 @item @code{shell} (default: Bash)
13932 This is a G-expression denoting the file name of a program to be used as
13933 the shell (@pxref{G-Expressions}). For example, you would refer to the
13934 Bash executable like this:
13937 (file-append bash "/bin/bash")
13941 ... and to the Zsh executable like that:
13944 (file-append zsh "/bin/zsh")
13947 @item @code{system?} (default: @code{#f})
13948 This Boolean value indicates whether the account is a ``system''
13949 account. System accounts are sometimes treated specially; for instance,
13950 graphical login managers do not list them.
13952 @anchor{user-account-password}
13953 @cindex password, for user accounts
13954 @item @code{password} (default: @code{#f})
13955 You would normally leave this field to @code{#f}, initialize user
13956 passwords as @code{root} with the @command{passwd} command, and then let
13957 users change it with @command{passwd}. Passwords set with
13958 @command{passwd} are of course preserved across reboot and
13961 If you @emph{do} want to set an initial password for an account, then
13962 this field must contain the encrypted password, as a string. You can use the
13963 @code{crypt} procedure for this purpose:
13970 ;; Specify a SHA-512-hashed initial password.
13971 (password (crypt "InitialPassword!" "$6$abc")))
13975 The hash of this initial password will be available in a file in
13976 @file{/gnu/store}, readable by all the users, so this method must be used with
13980 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
13981 more information on password encryption, and @ref{Encryption,,, guile, GNU
13982 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
13988 User group declarations are even simpler:
13991 (user-group (name "students"))
13994 @deftp {Data Type} user-group
13995 This type is for, well, user groups. There are just a few fields:
13999 The name of the group.
14001 @item @code{id} (default: @code{#f})
14002 The group identifier (a number). If @code{#f}, a new number is
14003 automatically allocated when the group is created.
14005 @item @code{system?} (default: @code{#f})
14006 This Boolean value indicates whether the group is a ``system'' group.
14007 System groups have low numerical IDs.
14009 @item @code{password} (default: @code{#f})
14010 What, user groups can have a password? Well, apparently yes. Unless
14011 @code{#f}, this field specifies the password of the group.
14016 For convenience, a variable lists all the basic user groups one may
14019 @defvr {Scheme Variable} %base-groups
14020 This is the list of basic user groups that users and/or packages expect
14021 to be present on the system. This includes groups such as ``root'',
14022 ``wheel'', and ``users'', as well as groups used to control access to
14023 specific devices such as ``audio'', ``disk'', and ``cdrom''.
14026 @defvr {Scheme Variable} %base-user-accounts
14027 This is the list of basic system accounts that programs may expect to
14028 find on a GNU/Linux system, such as the ``nobody'' account.
14030 Note that the ``root'' account is not included here. It is a
14031 special-case and is automatically added whether or not it is specified.
14034 @node Keyboard Layout
14035 @section Keyboard Layout
14037 @cindex keyboard layout
14039 To specify what each key of your keyboard does, you need to tell the operating
14040 system what @dfn{keyboard layout} you want to use. The default, when nothing
14041 is specified, is the US English QWERTY layout for 105-key PC keyboards.
14042 However, German speakers will usually prefer the German QWERTZ layout, French
14043 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
14044 or bépo, and they might even want to further customize the effect of some of
14045 the keys. This section explains how to get that done.
14047 @cindex keyboard layout, definition
14048 There are three components that will want to know about your keyboard layout:
14052 The @emph{bootloader} may want to know what keyboard layout you want to use
14053 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
14054 you want, for instance, to make sure that you can type the passphrase of your
14055 encrypted root partition using the right layout.
14058 The @emph{operating system kernel}, Linux, will need that so that the console
14059 is properly configured (@pxref{operating-system Reference,
14060 @code{keyboard-layout}}).
14063 The @emph{graphical display server}, usually Xorg, also has its own idea of
14064 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
14067 Guix allows you to configure all three separately but, fortunately, it allows
14068 you to share the same keyboard layout for all three components.
14070 @cindex XKB, keyboard layouts
14071 Keyboard layouts are represented by records created by the
14072 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
14073 the X Keyboard extension (XKB), each layout has four attributes: a name (often
14074 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
14075 optional variant name, an optional keyboard model name, and a possibly empty
14076 list of additional options. In most cases the layout name is all you care
14079 @deffn {Scheme Procedure} keyboard-layout @var{name} [@var{variant}] @
14080 [#:model] [#:options '()]
14081 Return a new keyboard layout with the given @var{name} and @var{variant}.
14083 @var{name} must be a string such as @code{"fr"}; @var{variant} must be a
14084 string such as @code{"bepo"} or @code{"nodeadkeys"}. See the
14085 @code{xkeyboard-config} package for valid options.
14088 Here are a few examples:
14091 ;; The German QWERTZ layout. Here we assume a standard
14092 ;; "pc105" keyboard model.
14093 (keyboard-layout "de")
14095 ;; The bépo variant of the French layout.
14096 (keyboard-layout "fr" "bepo")
14098 ;; The Catalan layout.
14099 (keyboard-layout "es" "cat")
14101 ;; Arabic layout with "Alt-Shift" to switch to US layout.
14102 (keyboard-layout "ar,us" #:options '("grp:alt_shift_toggle"))
14104 ;; The Latin American Spanish layout. In addition, the
14105 ;; "Caps Lock" key is used as an additional "Ctrl" key,
14106 ;; and the "Menu" key is used as a "Compose" key to enter
14107 ;; accented letters.
14108 (keyboard-layout "latam"
14109 #:options '("ctrl:nocaps" "compose:menu"))
14111 ;; The Russian layout for a ThinkPad keyboard.
14112 (keyboard-layout "ru" #:model "thinkpad")
14114 ;; The "US international" layout, which is the US layout plus
14115 ;; dead keys to enter accented characters. This is for an
14116 ;; Apple MacBook keyboard.
14117 (keyboard-layout "us" "intl" #:model "macbook78")
14120 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
14121 for a complete list of supported layouts, variants, and models.
14123 @cindex keyboard layout, configuration
14124 Let's say you want your system to use the Turkish keyboard layout throughout
14125 your system---bootloader, console, and Xorg. Here's what your system
14126 configuration would look like:
14128 @findex set-xorg-configuration
14130 ;; Using the Turkish layout for the bootloader, the console,
14135 (keyboard-layout (keyboard-layout "tr")) ;for the console
14136 (bootloader (bootloader-configuration
14137 (bootloader grub-efi-bootloader)
14138 (target "/boot/efi")
14139 (keyboard-layout keyboard-layout))) ;for GRUB
14140 (services (cons (set-xorg-configuration
14141 (xorg-configuration ;for Xorg
14142 (keyboard-layout keyboard-layout)))
14143 %desktop-services)))
14146 In the example above, for GRUB and for Xorg, we just refer to the
14147 @code{keyboard-layout} field defined above, but we could just as well refer to
14148 a different layout. The @code{set-xorg-configuration} procedure communicates
14149 the desired Xorg configuration to the graphical log-in manager, by default
14152 We've discussed how to specify the @emph{default} keyboard layout of your
14153 system when it starts, but you can also adjust it at run time:
14157 If you're using GNOME, its settings panel has a ``Region & Language'' entry
14158 where you can select one or more keyboard layouts.
14161 Under Xorg, the @command{setxkbmap} command (from the same-named package)
14162 allows you to change the current layout. For example, this is how you would
14163 change the layout to US Dvorak:
14166 setxkbmap us dvorak
14170 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
14171 console. However, note that @code{loadkeys} does @emph{not} use the XKB
14172 keyboard layout categorization described above. The command below loads the
14173 French bépo layout:
14184 A @dfn{locale} defines cultural conventions for a particular language
14185 and region of the world (@pxref{Locales,,, libc, The GNU C Library
14186 Reference Manual}). Each locale has a name that typically has the form
14187 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
14188 @code{fr_LU.utf8} designates the locale for the French language, with
14189 cultural conventions from Luxembourg, and using the UTF-8 encoding.
14191 @cindex locale definition
14192 Usually, you will want to specify the default locale for the machine
14193 using the @code{locale} field of the @code{operating-system} declaration
14194 (@pxref{operating-system Reference, @code{locale}}).
14196 The selected locale is automatically added to the @dfn{locale
14197 definitions} known to the system if needed, with its codeset inferred
14198 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
14199 @code{UTF-8} codeset. Additional locale definitions can be specified in
14200 the @code{locale-definitions} slot of @code{operating-system}---this is
14201 useful, for instance, if the codeset could not be inferred from the
14202 locale name. The default set of locale definitions includes some widely
14203 used locales, but not all the available locales, in order to save space.
14205 For instance, to add the North Frisian locale for Germany, the value of
14209 (cons (locale-definition
14210 (name "fy_DE.utf8") (source "fy_DE"))
14211 %default-locale-definitions)
14214 Likewise, to save space, one might want @code{locale-definitions} to
14215 list only the locales that are actually used, as in:
14218 (list (locale-definition
14219 (name "ja_JP.eucjp") (source "ja_JP")
14220 (charset "EUC-JP")))
14224 The compiled locale definitions are available at
14225 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
14226 version, which is the default location where the GNU@tie{}libc provided
14227 by Guix looks for locale data. This can be overridden using the
14228 @env{LOCPATH} environment variable (@pxref{locales-and-locpath,
14229 @env{LOCPATH} and locale packages}).
14231 The @code{locale-definition} form is provided by the @code{(gnu system
14232 locale)} module. Details are given below.
14234 @deftp {Data Type} locale-definition
14235 This is the data type of a locale definition.
14240 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
14241 Reference Manual}, for more information on locale names.
14243 @item @code{source}
14244 The name of the source for that locale. This is typically the
14245 @code{@var{language}_@var{territory}} part of the locale name.
14247 @item @code{charset} (default: @code{"UTF-8"})
14248 The ``character set'' or ``code set'' for that locale,
14249 @uref{https://www.iana.org/assignments/character-sets, as defined by
14255 @defvr {Scheme Variable} %default-locale-definitions
14256 A list of commonly used UTF-8 locales, used as the default
14257 value of the @code{locale-definitions} field of @code{operating-system}
14260 @cindex locale name
14261 @cindex normalized codeset in locale names
14262 These locale definitions use the @dfn{normalized codeset} for the part
14263 that follows the dot in the name (@pxref{Using gettextized software,
14264 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
14265 instance it has @code{uk_UA.utf8} but @emph{not}, say,
14266 @code{uk_UA.UTF-8}.
14269 @subsection Locale Data Compatibility Considerations
14271 @cindex incompatibility, of locale data
14272 @code{operating-system} declarations provide a @code{locale-libcs} field
14273 to specify the GNU@tie{}libc packages that are used to compile locale
14274 declarations (@pxref{operating-system Reference}). ``Why would I
14275 care?'', you may ask. Well, it turns out that the binary format of
14276 locale data is occasionally incompatible from one libc version to
14279 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
14280 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
14281 For instance, a program linked against libc version 2.21 is unable to
14282 read locale data produced with libc 2.22; worse, that program
14283 @emph{aborts} instead of simply ignoring the incompatible locale
14284 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
14285 the incompatible locale data, which is already an improvement.}.
14286 Similarly, a program linked against libc 2.22 can read most, but not
14287 all, of the locale data from libc 2.21 (specifically, @env{LC_COLLATE}
14288 data is incompatible); thus calls to @code{setlocale} may fail, but
14289 programs will not abort.
14291 The ``problem'' with Guix is that users have a lot of freedom: They can
14292 choose whether and when to upgrade software in their profiles, and might
14293 be using a libc version different from the one the system administrator
14294 used to build the system-wide locale data.
14296 Fortunately, unprivileged users can also install their own locale data
14297 and define @env{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
14298 @env{GUIX_LOCPATH} and locale packages}).
14300 Still, it is best if the system-wide locale data at
14301 @file{/run/current-system/locale} is built for all the libc versions
14302 actually in use on the system, so that all the programs can access
14303 it---this is especially crucial on a multi-user system. To do that, the
14304 administrator can specify several libc packages in the
14305 @code{locale-libcs} field of @code{operating-system}:
14308 (use-package-modules base)
14312 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
14315 This example would lead to a system containing locale definitions for
14316 both libc 2.21 and the current version of libc in
14317 @file{/run/current-system/locale}.
14323 @cindex system services
14324 An important part of preparing an @code{operating-system} declaration is
14325 listing @dfn{system services} and their configuration (@pxref{Using the
14326 Configuration System}). System services are typically daemons launched
14327 when the system boots, or other actions needed at that time---e.g.,
14328 configuring network access.
14330 Guix has a broad definition of ``service'' (@pxref{Service
14331 Composition}), but many services are managed by the GNU@tie{}Shepherd
14332 (@pxref{Shepherd Services}). On a running system, the @command{herd}
14333 command allows you to list the available services, show their status,
14334 start and stop them, or do other specific operations (@pxref{Jump
14335 Start,,, shepherd, The GNU Shepherd Manual}). For example:
14341 The above command, run as @code{root}, lists the currently defined
14342 services. The @command{herd doc} command shows a synopsis of the given
14343 service and its associated actions:
14347 Run libc's name service cache daemon (nscd).
14349 # herd doc nscd action invalidate
14350 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
14353 The @command{start}, @command{stop}, and @command{restart} sub-commands
14354 have the effect you would expect. For instance, the commands below stop
14355 the nscd service and restart the Xorg display server:
14359 Service nscd has been stopped.
14360 # herd restart xorg-server
14361 Service xorg-server has been stopped.
14362 Service xorg-server has been started.
14365 The following sections document the available services, starting with
14366 the core services, that may be used in an @code{operating-system}
14370 * Base Services:: Essential system services.
14371 * Scheduled Job Execution:: The mcron service.
14372 * Log Rotation:: The rottlog service.
14373 * Networking Services:: Network setup, SSH daemon, etc.
14374 * Unattended Upgrades:: Automated system upgrades.
14375 * X Window:: Graphical display.
14376 * Printing Services:: Local and remote printer support.
14377 * Desktop Services:: D-Bus and desktop services.
14378 * Sound Services:: ALSA and Pulseaudio services.
14379 * Database Services:: SQL databases, key-value stores, etc.
14380 * Mail Services:: IMAP, POP3, SMTP, and all that.
14381 * Messaging Services:: Messaging services.
14382 * Telephony Services:: Telephony services.
14383 * Monitoring Services:: Monitoring services.
14384 * Kerberos Services:: Kerberos services.
14385 * LDAP Services:: LDAP services.
14386 * Web Services:: Web servers.
14387 * Certificate Services:: TLS certificates via Let's Encrypt.
14388 * DNS Services:: DNS daemons.
14389 * VPN Services:: VPN daemons.
14390 * Network File System:: NFS related services.
14391 * Continuous Integration:: The Cuirass service.
14392 * Power Management Services:: Extending battery life.
14393 * Audio Services:: The MPD.
14394 * Virtualization Services:: Virtualization services.
14395 * Version Control Services:: Providing remote access to Git repositories.
14396 * Game Services:: Game servers.
14397 * PAM Mount Service:: Service to mount volumes when logging in.
14398 * Guix Services:: Services relating specifically to Guix.
14399 * Linux Services:: Services tied to the Linux kernel.
14400 * Hurd Services:: Services specific for a Hurd System.
14401 * Miscellaneous Services:: Other services.
14404 @node Base Services
14405 @subsection Base Services
14407 The @code{(gnu services base)} module provides definitions for the basic
14408 services that one expects from the system. The services exported by
14409 this module are listed below.
14411 @defvr {Scheme Variable} %base-services
14412 This variable contains a list of basic services (@pxref{Service Types
14413 and Services}, for more information on service objects) one would
14414 expect from the system: a login service (mingetty) on each tty, syslogd,
14415 the libc name service cache daemon (nscd), the udev device manager, and
14418 This is the default value of the @code{services} field of
14419 @code{operating-system} declarations. Usually, when customizing a
14420 system, you will want to append services to @code{%base-services}, like
14424 (append (list (service avahi-service-type)
14425 (service openssh-service-type))
14430 @defvr {Scheme Variable} special-files-service-type
14431 This is the service that sets up ``special files'' such as
14432 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
14434 The value associated with @code{special-files-service-type} services
14435 must be a list of tuples where the first element is the ``special file''
14436 and the second element is its target. By default it is:
14438 @cindex @file{/bin/sh}
14439 @cindex @file{sh}, in @file{/bin}
14441 `(("/bin/sh" ,(file-append bash "/bin/sh")))
14444 @cindex @file{/usr/bin/env}
14445 @cindex @file{env}, in @file{/usr/bin}
14446 If you want to add, say, @code{/usr/bin/env} to your system, you can
14450 `(("/bin/sh" ,(file-append bash "/bin/sh"))
14451 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
14454 Since this is part of @code{%base-services}, you can use
14455 @code{modify-services} to customize the set of special files
14456 (@pxref{Service Reference, @code{modify-services}}). But the simple way
14457 to add a special file is @i{via} the @code{extra-special-file} procedure
14461 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
14462 Use @var{target} as the ``special file'' @var{file}.
14464 For example, adding the following lines to the @code{services} field of
14465 your operating system declaration leads to a @file{/usr/bin/env}
14469 (extra-special-file "/usr/bin/env"
14470 (file-append coreutils "/bin/env"))
14474 @deffn {Scheme Procedure} host-name-service @var{name}
14475 Return a service that sets the host name to @var{name}.
14478 @defvr {Scheme Variable} console-font-service-type
14479 Install the given fonts on the specified ttys (fonts are per
14480 virtual console on the kernel Linux). The value of this service is a list of
14481 tty/font pairs. The font can be the name of a font provided by the @code{kbd}
14482 package or any valid argument to @command{setfont}, as in this example:
14485 `(("tty1" . "LatGrkCyr-8x16")
14486 ("tty2" . ,(file-append
14488 "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
14489 ("tty3" . ,(file-append
14491 "/share/consolefonts/ter-132n"))) ; for HDPI
14495 @deffn {Scheme Procedure} login-service @var{config}
14496 Return a service to run login according to @var{config}, a
14497 @code{<login-configuration>} object, which specifies the message of the day,
14498 among other things.
14501 @deftp {Data Type} login-configuration
14502 This is the data type representing the configuration of login.
14507 @cindex message of the day
14508 A file-like object containing the ``message of the day''.
14510 @item @code{allow-empty-passwords?} (default: @code{#t})
14511 Allow empty passwords by default so that first-time users can log in when
14512 the 'root' account has just been created.
14517 @deffn {Scheme Procedure} mingetty-service @var{config}
14518 Return a service to run mingetty according to @var{config}, a
14519 @code{<mingetty-configuration>} object, which specifies the tty to run, among
14523 @deftp {Data Type} mingetty-configuration
14524 This is the data type representing the configuration of Mingetty, which
14525 provides the default implementation of virtual console log-in.
14530 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
14532 @item @code{auto-login} (default: @code{#f})
14533 When true, this field must be a string denoting the user name under
14534 which the system automatically logs in. When it is @code{#f}, a
14535 user name and password must be entered to log in.
14537 @item @code{login-program} (default: @code{#f})
14538 This must be either @code{#f}, in which case the default log-in program
14539 is used (@command{login} from the Shadow tool suite), or a gexp denoting
14540 the name of the log-in program.
14542 @item @code{login-pause?} (default: @code{#f})
14543 When set to @code{#t} in conjunction with @var{auto-login}, the user
14544 will have to press a key before the log-in shell is launched.
14546 @item @code{clear-on-logout?} (default: @code{#t})
14547 When set to @code{#t}, the screen will be cleared after logout.
14549 @item @code{mingetty} (default: @var{mingetty})
14550 The Mingetty package to use.
14555 @deffn {Scheme Procedure} agetty-service @var{config}
14556 Return a service to run agetty according to @var{config}, an
14557 @code{<agetty-configuration>} object, which specifies the tty to run,
14558 among other things.
14561 @deftp {Data Type} agetty-configuration
14562 This is the data type representing the configuration of agetty, which
14563 implements virtual and serial console log-in. See the @code{agetty(8)}
14564 man page for more information.
14569 The name of the console this agetty runs on, as a string---e.g.,
14570 @code{"ttyS0"}. This argument is optional, it will default to
14571 a reasonable default serial port used by the kernel Linux.
14573 For this, if there is a value for an option @code{agetty.tty} in the kernel
14574 command line, agetty will extract the device name of the serial port
14575 from it and use that.
14577 If not and if there is a value for an option @code{console} with a tty in
14578 the Linux command line, agetty will extract the device name of the
14579 serial port from it and use that.
14581 In both cases, agetty will leave the other serial device settings
14582 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
14585 @item @code{baud-rate} (default: @code{#f})
14586 A string containing a comma-separated list of one or more baud rates, in
14589 @item @code{term} (default: @code{#f})
14590 A string containing the value used for the @env{TERM} environment
14593 @item @code{eight-bits?} (default: @code{#f})
14594 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
14597 @item @code{auto-login} (default: @code{#f})
14598 When passed a login name, as a string, the specified user will be logged
14599 in automatically without prompting for their login name or password.
14601 @item @code{no-reset?} (default: @code{#f})
14602 When @code{#t}, don't reset terminal cflags (control modes).
14604 @item @code{host} (default: @code{#f})
14605 This accepts a string containing the ``login_host'', which will be written
14606 into the @file{/var/run/utmpx} file.
14608 @item @code{remote?} (default: @code{#f})
14609 When set to @code{#t} in conjunction with @var{host}, this will add an
14610 @code{-r} fakehost option to the command line of the login program
14611 specified in @var{login-program}.
14613 @item @code{flow-control?} (default: @code{#f})
14614 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
14616 @item @code{no-issue?} (default: @code{#f})
14617 When set to @code{#t}, the contents of the @file{/etc/issue} file will
14618 not be displayed before presenting the login prompt.
14620 @item @code{init-string} (default: @code{#f})
14621 This accepts a string that will be sent to the tty or modem before
14622 sending anything else. It can be used to initialize a modem.
14624 @item @code{no-clear?} (default: @code{#f})
14625 When set to @code{#t}, agetty will not clear the screen before showing
14628 @item @code{login-program} (default: (file-append shadow "/bin/login"))
14629 This must be either a gexp denoting the name of a log-in program, or
14630 unset, in which case the default value is the @command{login} from the
14633 @item @code{local-line} (default: @code{#f})
14634 Control the CLOCAL line flag. This accepts one of three symbols as
14635 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
14636 the default value chosen by agetty is @code{'auto}.
14638 @item @code{extract-baud?} (default: @code{#f})
14639 When set to @code{#t}, instruct agetty to try to extract the baud rate
14640 from the status messages produced by certain types of modems.
14642 @item @code{skip-login?} (default: @code{#f})
14643 When set to @code{#t}, do not prompt the user for a login name. This
14644 can be used with @var{login-program} field to use non-standard login
14647 @item @code{no-newline?} (default: @code{#f})
14648 When set to @code{#t}, do not print a newline before printing the
14649 @file{/etc/issue} file.
14651 @c Is this dangerous only when used with login-program, or always?
14652 @item @code{login-options} (default: @code{#f})
14653 This option accepts a string containing options that are passed to the
14654 login program. When used with the @var{login-program}, be aware that a
14655 malicious user could try to enter a login name containing embedded
14656 options that could be parsed by the login program.
14658 @item @code{login-pause} (default: @code{#f})
14659 When set to @code{#t}, wait for any key before showing the login prompt.
14660 This can be used in conjunction with @var{auto-login} to save memory by
14661 lazily spawning shells.
14663 @item @code{chroot} (default: @code{#f})
14664 Change root to the specified directory. This option accepts a directory
14667 @item @code{hangup?} (default: @code{#f})
14668 Use the Linux system call @code{vhangup} to do a virtual hangup of the
14669 specified terminal.
14671 @item @code{keep-baud?} (default: @code{#f})
14672 When set to @code{#t}, try to keep the existing baud rate. The baud
14673 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
14676 @item @code{timeout} (default: @code{#f})
14677 When set to an integer value, terminate if no user name could be read
14678 within @var{timeout} seconds.
14680 @item @code{detect-case?} (default: @code{#f})
14681 When set to @code{#t}, turn on support for detecting an uppercase-only
14682 terminal. This setting will detect a login name containing only
14683 uppercase letters as indicating an uppercase-only terminal and turn on
14684 some upper-to-lower case conversions. Note that this will not support
14685 Unicode characters.
14687 @item @code{wait-cr?} (default: @code{#f})
14688 When set to @code{#t}, wait for the user or modem to send a
14689 carriage-return or linefeed character before displaying
14690 @file{/etc/issue} or login prompt. This is typically used with the
14691 @var{init-string} option.
14693 @item @code{no-hints?} (default: @code{#f})
14694 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
14697 @item @code{no-hostname?} (default: @code{#f})
14698 By default, the hostname is printed. When this option is set to
14699 @code{#t}, no hostname will be shown at all.
14701 @item @code{long-hostname?} (default: @code{#f})
14702 By default, the hostname is only printed until the first dot. When this
14703 option is set to @code{#t}, the fully qualified hostname by
14704 @code{gethostname} or @code{getaddrinfo} is shown.
14706 @item @code{erase-characters} (default: @code{#f})
14707 This option accepts a string of additional characters that should be
14708 interpreted as backspace when the user types their login name.
14710 @item @code{kill-characters} (default: @code{#f})
14711 This option accepts a string that should be interpreted to mean ``ignore
14712 all previous characters'' (also called a ``kill'' character) when the user
14713 types their login name.
14715 @item @code{chdir} (default: @code{#f})
14716 This option accepts, as a string, a directory path that will be changed
14719 @item @code{delay} (default: @code{#f})
14720 This options accepts, as an integer, the number of seconds to sleep
14721 before opening the tty and displaying the login prompt.
14723 @item @code{nice} (default: @code{#f})
14724 This option accepts, as an integer, the nice value with which to run the
14725 @command{login} program.
14727 @item @code{extra-options} (default: @code{'()})
14728 This option provides an ``escape hatch'' for the user to provide arbitrary
14729 command-line arguments to @command{agetty} as a list of strings.
14734 @deffn {Scheme Procedure} kmscon-service-type @var{config}
14735 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
14736 according to @var{config}, a @code{<kmscon-configuration>} object, which
14737 specifies the tty to run, among other things.
14740 @deftp {Data Type} kmscon-configuration
14741 This is the data type representing the configuration of Kmscon, which
14742 implements virtual console log-in.
14746 @item @code{virtual-terminal}
14747 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
14749 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
14750 A gexp denoting the name of the log-in program. The default log-in program is
14751 @command{login} from the Shadow tool suite.
14753 @item @code{login-arguments} (default: @code{'("-p")})
14754 A list of arguments to pass to @command{login}.
14756 @item @code{auto-login} (default: @code{#f})
14757 When passed a login name, as a string, the specified user will be logged
14758 in automatically without prompting for their login name or password.
14760 @item @code{hardware-acceleration?} (default: #f)
14761 Whether to use hardware acceleration.
14763 @item @code{kmscon} (default: @var{kmscon})
14764 The Kmscon package to use.
14769 @cindex name service cache daemon
14771 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
14772 [#:name-services '()]
14773 Return a service that runs the libc name service cache daemon (nscd) with the
14774 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
14775 Service Switch}, for an example.
14777 For convenience, the Shepherd service for nscd provides the following actions:
14781 @cindex cache invalidation, nscd
14782 @cindex nscd, cache invalidation
14783 This invalidate the given cache. For instance, running:
14786 herd invalidate nscd hosts
14790 invalidates the host name lookup cache of nscd.
14793 Running @command{herd statistics nscd} displays information about nscd usage
14799 @defvr {Scheme Variable} %nscd-default-configuration
14800 This is the default @code{<nscd-configuration>} value (see below) used
14801 by @code{nscd-service}. It uses the caches defined by
14802 @code{%nscd-default-caches}; see below.
14805 @deftp {Data Type} nscd-configuration
14806 This is the data type representing the name service cache daemon (nscd)
14811 @item @code{name-services} (default: @code{'()})
14812 List of packages denoting @dfn{name services} that must be visible to
14813 the nscd---e.g., @code{(list @var{nss-mdns})}.
14815 @item @code{glibc} (default: @var{glibc})
14816 Package object denoting the GNU C Library providing the @command{nscd}
14819 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
14820 Name of the nscd log file. This is where debugging output goes when
14821 @code{debug-level} is strictly positive.
14823 @item @code{debug-level} (default: @code{0})
14824 Integer denoting the debugging levels. Higher numbers mean that more
14825 debugging output is logged.
14827 @item @code{caches} (default: @code{%nscd-default-caches})
14828 List of @code{<nscd-cache>} objects denoting things to be cached; see
14834 @deftp {Data Type} nscd-cache
14835 Data type representing a cache database of nscd and its parameters.
14839 @item @code{database}
14840 This is a symbol representing the name of the database to be cached.
14841 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
14842 @code{services}, which designate the corresponding NSS database
14843 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
14845 @item @code{positive-time-to-live}
14846 @itemx @code{negative-time-to-live} (default: @code{20})
14847 A number representing the number of seconds during which a positive or
14848 negative lookup result remains in cache.
14850 @item @code{check-files?} (default: @code{#t})
14851 Whether to check for updates of the files corresponding to
14854 For instance, when @var{database} is @code{hosts}, setting this flag
14855 instructs nscd to check for updates in @file{/etc/hosts} and to take
14858 @item @code{persistent?} (default: @code{#t})
14859 Whether the cache should be stored persistently on disk.
14861 @item @code{shared?} (default: @code{#t})
14862 Whether the cache should be shared among users.
14864 @item @code{max-database-size} (default: 32@tie{}MiB)
14865 Maximum size in bytes of the database cache.
14867 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
14868 @c settings, so leave them out.
14873 @defvr {Scheme Variable} %nscd-default-caches
14874 List of @code{<nscd-cache>} objects used by default by
14875 @code{nscd-configuration} (see above).
14877 It enables persistent and aggressive caching of service and host name
14878 lookups. The latter provides better host name lookup performance,
14879 resilience in the face of unreliable name servers, and also better
14880 privacy---often the result of host name lookups is in local cache, so
14881 external name servers do not even need to be queried.
14884 @anchor{syslog-configuration-type}
14887 @deftp {Data Type} syslog-configuration
14888 This data type represents the configuration of the syslog daemon.
14891 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
14892 The syslog daemon to use.
14894 @item @code{config-file} (default: @code{%default-syslog.conf})
14895 The syslog configuration file to use.
14900 @anchor{syslog-service}
14902 @deffn {Scheme Procedure} syslog-service @var{config}
14903 Return a service that runs a syslog daemon according to @var{config}.
14905 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
14906 information on the configuration file syntax.
14909 @defvr {Scheme Variable} guix-service-type
14910 This is the type of the service that runs the build daemon,
14911 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
14912 @code{guix-configuration} record as described below.
14915 @anchor{guix-configuration-type}
14916 @deftp {Data Type} guix-configuration
14917 This data type represents the configuration of the Guix build daemon.
14918 @xref{Invoking guix-daemon}, for more information.
14921 @item @code{guix} (default: @var{guix})
14922 The Guix package to use.
14924 @item @code{build-group} (default: @code{"guixbuild"})
14925 Name of the group for build user accounts.
14927 @item @code{build-accounts} (default: @code{10})
14928 Number of build user accounts to create.
14930 @item @code{authorize-key?} (default: @code{#t})
14931 @cindex substitutes, authorization thereof
14932 Whether to authorize the substitute keys listed in
14933 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
14934 (@pxref{Substitutes}).
14936 When @code{authorize-key?} is true, @file{/etc/guix/acl} cannot be
14937 changed by invoking @command{guix archive --authorize}. You must
14938 instead adjust @code{guix-configuration} as you wish and reconfigure the
14939 system. This ensures that your operating system configuration file is
14943 When booting or reconfiguring to a system where @code{authorize-key?}
14944 is true, the existing @file{/etc/guix/acl} file is backed up as
14945 @file{/etc/guix/acl.bak} if it was determined to be a manually modified
14946 file. This is to facilitate migration from earlier versions, which
14947 allowed for in-place modifications to @file{/etc/guix/acl}.
14950 @vindex %default-authorized-guix-keys
14951 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
14952 The list of authorized key files for archive imports, as a list of
14953 string-valued gexps (@pxref{Invoking guix archive}). By default, it
14954 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
14955 See @code{substitute-urls} below for an example on how to change it.
14957 @item @code{use-substitutes?} (default: @code{#t})
14958 Whether to use substitutes.
14960 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
14961 The list of URLs where to look for substitutes by default.
14963 Suppose you would like to fetch substitutes from @code{guix.example.org}
14964 in addition to @code{@value{SUBSTITUTE-SERVER}}. You will need to do
14965 two things: (1) add @code{guix.example.org} to @code{substitute-urls},
14966 and (2) authorize its signing key, having done appropriate checks
14967 (@pxref{Substitute Server Authorization}). The configuration below does
14971 (guix-configuration
14973 (append (list "https://guix.example.org")
14974 %default-substitute-urls))
14976 (append (list (local-file "./guix.example.org-key.pub"))
14977 %default-authorized-guix-keys)))
14980 This example assumes that the file @file{./guix.example.org-key.pub}
14981 contains the public key that @code{guix.example.org} uses to sign
14984 @item @code{max-silent-time} (default: @code{0})
14985 @itemx @code{timeout} (default: @code{0})
14986 The number of seconds of silence and the number of seconds of activity,
14987 respectively, after which a build process times out. A value of zero
14988 disables the timeout.
14990 @item @code{log-compression} (default: @code{'bzip2})
14991 The type of compression used for build logs---one of @code{gzip},
14992 @code{bzip2}, or @code{none}.
14994 @item @code{extra-options} (default: @code{'()})
14995 List of extra command-line options for @command{guix-daemon}.
14997 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
14998 File where @command{guix-daemon}'s standard output and standard error
15001 @cindex HTTP proxy, for @code{guix-daemon}
15002 @cindex proxy, for @code{guix-daemon} HTTP access
15003 @item @code{http-proxy} (default: @code{#f})
15004 The URL of the HTTP and HTTPS proxy used for downloading fixed-output
15005 derivations and substitutes.
15007 It is also possible to change the daemon's proxy at run time through the
15008 @code{set-http-proxy} action, which restarts it:
15011 herd set-http-proxy guix-daemon http://localhost:8118
15014 To clear the proxy settings, run:
15017 herd set-http-proxy guix-daemon
15020 @item @code{tmpdir} (default: @code{#f})
15021 A directory path where the @command{guix-daemon} will perform builds.
15026 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
15027 Run @var{udev}, which populates the @file{/dev} directory dynamically.
15028 udev rules can be provided as a list of files through the @var{rules}
15029 variable. The procedures @code{udev-rule}, @code{udev-rules-service}
15030 and @code{file->udev-rule} from @code{(gnu services base)} simplify the
15031 creation of such rule files.
15033 The @command{herd rules udev} command, as root, returns the name of the
15034 directory containing all the active udev rules.
15037 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
15038 Return a udev-rule file named @var{file-name} containing the rules
15039 defined by the @var{contents} literal.
15041 In the following example, a rule for a USB device is defined to be
15042 stored in the file @file{90-usb-thing.rules}. The rule runs a script
15043 upon detecting a USB device with a given product identifier.
15046 (define %example-udev-rule
15048 "90-usb-thing.rules"
15049 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
15050 "ATTR@{product@}==\"Example\", "
15051 "RUN+=\"/path/to/script\"")))
15055 @deffn {Scheme Procedure} udev-rules-service [@var{name} @var{rules}] @
15056 [#:groups @var{groups}]
15057 Return a service that extends @code{udev-service-type } with @var{rules}
15058 and @code{account-service-type} with @var{groups} as system groups.
15059 This works by creating a singleton service type
15060 @code{@var{name}-udev-rules}, of which the returned service is an
15063 Here we show how it can be used to extend @code{udev-service-type} with the
15064 previously defined rule @code{%example-udev-rule}.
15070 (cons (udev-rules-service 'usb-thing %example-udev-rule)
15071 %desktop-services)))
15075 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
15076 Return a udev file named @var{file-name} containing the rules defined
15077 within @var{file}, a file-like object.
15079 The following example showcases how we can use an existing rule file.
15082 (use-modules (guix download) ;for url-fetch
15083 (guix packages) ;for origin
15086 (define %android-udev-rules
15088 "51-android-udev.rules"
15089 (let ((version "20170910"))
15092 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
15093 "android-udev-rules/" version "/51-android.rules"))
15095 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
15099 Additionally, Guix package definitions can be included in @var{rules} in
15100 order to extend the udev rules with the definitions found under their
15101 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
15102 @var{file->udev-rule} example, we could have used the
15103 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
15104 packages android)} module.
15106 The following example shows how to use the @var{android-udev-rules}
15107 package so that the Android tool @command{adb} can detect devices
15108 without root privileges. It also details how to create the
15109 @code{adbusers} group, which is required for the proper functioning of
15110 the rules defined within the @code{android-udev-rules} package. To
15111 create such a group, we must define it both as part of the
15112 @code{supplementary-groups} of our @code{user-account} declaration, as
15113 well as in the @var{groups} of the @code{udev-rules-service} procedure.
15116 (use-modules (gnu packages android) ;for android-udev-rules
15117 (gnu system shadow) ;for user-group
15122 (users (cons (user-account
15124 (supplementary-groups
15125 '("adbusers" ;for adb
15126 "wheel" "netdev" "audio" "video")))))
15129 (cons (udev-rules-service 'android android-udev-rules
15130 #:groups '("adbusers"))
15131 %desktop-services)))
15134 @defvr {Scheme Variable} urandom-seed-service-type
15135 Save some entropy in @code{%random-seed-file} to seed @file{/dev/urandom}
15136 when rebooting. It also tries to seed @file{/dev/urandom} from
15137 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
15141 @defvr {Scheme Variable} %random-seed-file
15142 This is the name of the file where some random bytes are saved by
15143 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
15144 It defaults to @file{/var/lib/random-seed}.
15149 @defvr {Scheme Variable} gpm-service-type
15150 This is the type of the service that runs GPM, the @dfn{general-purpose
15151 mouse daemon}, which provides mouse support to the Linux console. GPM
15152 allows users to use the mouse in the console, notably to select, copy,
15155 The value for services of this type must be a @code{gpm-configuration}
15156 (see below). This service is not part of @code{%base-services}.
15159 @deftp {Data Type} gpm-configuration
15160 Data type representing the configuration of GPM.
15163 @item @code{options} (default: @code{%default-gpm-options})
15164 Command-line options passed to @command{gpm}. The default set of
15165 options instruct @command{gpm} to listen to mouse events on
15166 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
15169 @item @code{gpm} (default: @code{gpm})
15170 The GPM package to use.
15175 @anchor{guix-publish-service-type}
15176 @deffn {Scheme Variable} guix-publish-service-type
15177 This is the service type for @command{guix publish} (@pxref{Invoking
15178 guix publish}). Its value must be a @code{guix-publish-configuration}
15179 object, as described below.
15181 This assumes that @file{/etc/guix} already contains a signing key pair as
15182 created by @command{guix archive --generate-key} (@pxref{Invoking guix
15183 archive}). If that is not the case, the service will fail to start.
15186 @deftp {Data Type} guix-publish-configuration
15187 Data type representing the configuration of the @code{guix publish}
15191 @item @code{guix} (default: @code{guix})
15192 The Guix package to use.
15194 @item @code{port} (default: @code{80})
15195 The TCP port to listen for connections.
15197 @item @code{host} (default: @code{"localhost"})
15198 The host (and thus, network interface) to listen to. Use
15199 @code{"0.0.0.0"} to listen on all the network interfaces.
15201 @item @code{compression} (default: @code{'(("gzip" 3))})
15202 This is a list of compression method/level tuple used when compressing
15203 substitutes. For example, to compress all substitutes with @emph{both} lzip
15204 at level 7 and gzip at level 9, write:
15207 '(("lzip" 7) ("gzip" 9))
15210 Level 9 achieves the best compression ratio at the expense of increased CPU
15211 usage, whereas level 1 achieves fast compression.
15213 An empty list disables compression altogether.
15215 @item @code{nar-path} (default: @code{"nar"})
15216 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
15217 publish, @option{--nar-path}}, for details.
15219 @item @code{cache} (default: @code{#f})
15220 When it is @code{#f}, disable caching and instead generate archives on
15221 demand. Otherwise, this should be the name of a directory---e.g.,
15222 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
15223 archives and meta-data ready to be sent. @xref{Invoking guix publish,
15224 @option{--cache}}, for more information on the tradeoffs involved.
15226 @item @code{workers} (default: @code{#f})
15227 When it is an integer, this is the number of worker threads used for
15228 caching; when @code{#f}, the number of processors is used.
15229 @xref{Invoking guix publish, @option{--workers}}, for more information.
15231 @item @code{cache-bypass-threshold} (default: 10 MiB)
15232 When @code{cache} is true, this is the maximum size in bytes of a store
15233 item for which @command{guix publish} may bypass its cache in case of a
15234 cache miss. @xref{Invoking guix publish,
15235 @option{--cache-bypass-threshold}}, for more information.
15237 @item @code{ttl} (default: @code{#f})
15238 When it is an integer, this denotes the @dfn{time-to-live} in seconds
15239 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
15240 for more information.
15244 @anchor{rngd-service}
15245 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
15246 [#:device "/dev/hwrng"]
15247 Return a service that runs the @command{rngd} program from @var{rng-tools}
15248 to add @var{device} to the kernel's entropy pool. The service will fail if
15249 @var{device} does not exist.
15252 @anchor{pam-limits-service}
15253 @cindex session limits
15258 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
15260 Return a service that installs a configuration file for the
15261 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
15262 @code{pam_limits} module}. The procedure optionally takes a list of
15263 @code{pam-limits-entry} values, which can be used to specify
15264 @code{ulimit} limits and nice priority limits to user sessions.
15266 The following limits definition sets two hard and soft limits for all
15267 login sessions of users in the @code{realtime} group:
15270 (pam-limits-service
15272 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
15273 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
15276 The first entry increases the maximum realtime priority for
15277 non-privileged processes; the second entry lifts any restriction of the
15278 maximum address space that can be locked in memory. These settings are
15279 commonly used for real-time audio systems.
15282 @node Scheduled Job Execution
15283 @subsection Scheduled Job Execution
15287 @cindex scheduling jobs
15288 The @code{(gnu services mcron)} module provides an interface to
15289 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
15290 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
15291 Unix @command{cron} daemon; the main difference is that it is
15292 implemented in Guile Scheme, which provides a lot of flexibility when
15293 specifying the scheduling of jobs and their actions.
15295 The example below defines an operating system that runs the
15296 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
15297 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
15298 well as the @command{mkid} command on behalf of an unprivileged user
15299 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
15300 gexps to introduce job definitions that are passed to mcron
15301 (@pxref{G-Expressions}).
15304 (use-modules (guix) (gnu) (gnu services mcron))
15305 (use-package-modules base idutils)
15307 (define updatedb-job
15308 ;; Run 'updatedb' at 3AM every day. Here we write the
15309 ;; job's action as a Scheme procedure.
15310 #~(job '(next-hour '(3))
15312 (execl (string-append #$findutils "/bin/updatedb")
15314 "--prunepaths=/tmp /var/tmp /gnu/store"))))
15316 (define garbage-collector-job
15317 ;; Collect garbage 5 minutes after midnight every day.
15318 ;; The job's action is a shell command.
15319 #~(job "5 0 * * *" ;Vixie cron syntax
15322 (define idutils-job
15323 ;; Update the index database as user "charlie" at 12:15PM
15324 ;; and 19:15PM. This runs from the user's home directory.
15325 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
15326 (string-append #$idutils "/bin/mkid src")
15331 (services (cons (service mcron-service-type
15332 (mcron-configuration
15333 (jobs (list garbage-collector-job
15339 For more complex jobs defined in Scheme where you need control over the top
15340 level, for instance to introduce a @code{use-modules} form, you can move your
15341 code to a separate program using the @code{program-file} procedure of the
15342 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
15346 (define %battery-alert-job
15347 ;; Beep when the battery percentage falls below %MIN-LEVEL.
15349 '(next-minute (range 0 60 1))
15351 "battery-alert.scm"
15352 (with-imported-modules (source-module-closure
15353 '((guix build utils)))
15355 (use-modules (guix build utils)
15358 (ice-9 textual-ports)
15361 (define %min-level 20)
15363 (setenv "LC_ALL" "C") ;ensure English output
15364 (and-let* ((input-pipe (open-pipe*
15366 #$(file-append acpi "/bin/acpi")))
15367 (output (get-string-all input-pipe))
15368 (m (string-match "Discharging, ([0-9]+)%" output))
15369 (level (string->number (match:substring m 1)))
15370 ((< level %min-level)))
15371 (format #t "warning: Battery level is low (~a%)~%" level)
15372 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
15375 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
15376 for more information on mcron job specifications. Below is the
15377 reference of the mcron service.
15379 On a running system, you can use the @code{schedule} action of the service to
15380 visualize the mcron jobs that will be executed next:
15383 # herd schedule mcron
15387 The example above lists the next five tasks that will be executed, but you can
15388 also specify the number of tasks to display:
15391 # herd schedule mcron 10
15394 @defvr {Scheme Variable} mcron-service-type
15395 This is the type of the @code{mcron} service, whose value is an
15396 @code{mcron-configuration} object.
15398 This service type can be the target of a service extension that provides
15399 it additional job specifications (@pxref{Service Composition}). In
15400 other words, it is possible to define services that provide additional
15404 @deftp {Data Type} mcron-configuration
15405 Data type representing the configuration of mcron.
15408 @item @code{mcron} (default: @var{mcron})
15409 The mcron package to use.
15412 This is a list of gexps (@pxref{G-Expressions}), where each gexp
15413 corresponds to an mcron job specification (@pxref{Syntax, mcron job
15414 specifications,, mcron, GNU@tie{}mcron}).
15420 @subsection Log Rotation
15423 @cindex log rotation
15425 Log files such as those found in @file{/var/log} tend to grow endlessly,
15426 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
15427 their contents in separate files, possibly compressed. The @code{(gnu
15428 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
15429 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
15431 This service is part of @code{%base-services}, and thus enabled by
15432 default, with the default settings, for commonly encountered log files.
15433 The example below shows how to extend it with an additional
15434 @dfn{rotation}, should you need to do that (usually, services that
15435 produce log files already take care of that):
15438 (use-modules (guix) (gnu))
15439 (use-service-modules admin)
15441 (define my-log-files
15442 ;; Log files that I want to rotate.
15443 '("/var/log/something.log" "/var/log/another.log"))
15447 (services (cons (simple-service 'rotate-my-stuff
15448 rottlog-service-type
15449 (list (log-rotation
15451 (files my-log-files))))
15455 @defvr {Scheme Variable} rottlog-service-type
15456 This is the type of the Rottlog service, whose value is a
15457 @code{rottlog-configuration} object.
15459 Other services can extend this one with new @code{log-rotation} objects
15460 (see below), thereby augmenting the set of files to be rotated.
15462 This service type can define mcron jobs (@pxref{Scheduled Job
15463 Execution}) to run the rottlog service.
15466 @deftp {Data Type} rottlog-configuration
15467 Data type representing the configuration of rottlog.
15470 @item @code{rottlog} (default: @code{rottlog})
15471 The Rottlog package to use.
15473 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
15474 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
15475 rottlog, GNU Rot[t]log Manual}).
15477 @item @code{rotations} (default: @code{%default-rotations})
15478 A list of @code{log-rotation} objects as defined below.
15481 This is a list of gexps where each gexp corresponds to an mcron job
15482 specification (@pxref{Scheduled Job Execution}).
15486 @deftp {Data Type} log-rotation
15487 Data type representing the rotation of a group of log files.
15489 Taking an example from the Rottlog manual (@pxref{Period Related File
15490 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
15496 (files '("/var/log/apache/*"))
15497 (options '("storedir apache-archives"
15503 The list of fields is as follows:
15506 @item @code{frequency} (default: @code{'weekly})
15507 The log rotation frequency, a symbol.
15510 The list of files or file glob patterns to rotate.
15512 @item @code{options} (default: @code{'()})
15513 The list of rottlog options for this rotation (@pxref{Configuration
15514 parameters,,, rottlog, GNU Rot[t]lg Manual}).
15516 @item @code{post-rotate} (default: @code{#f})
15517 Either @code{#f} or a gexp to execute once the rotation has completed.
15521 @defvr {Scheme Variable} %default-rotations
15522 Specifies weekly rotation of @code{%rotated-files} and of
15523 @file{/var/log/guix-daemon.log}.
15526 @defvr {Scheme Variable} %rotated-files
15527 The list of syslog-controlled files to be rotated. By default it is:
15528 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
15529 "/var/log/maillog")}.
15532 @node Networking Services
15533 @subsection Networking Services
15535 The @code{(gnu services networking)} module provides services to configure
15536 the network interface.
15538 @cindex DHCP, networking service
15539 @defvr {Scheme Variable} dhcp-client-service-type
15540 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
15541 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
15542 is the DHCP client package to use, @code{isc-dhcp} by default.
15545 @deffn {Scheme Procedure} dhcpd-service-type
15546 This type defines a service that runs a DHCP daemon. To create a
15547 service of this type, you must supply a @code{<dhcpd-configuration>}.
15551 (service dhcpd-service-type
15552 (dhcpd-configuration
15553 (config-file (local-file "my-dhcpd.conf"))
15554 (interfaces '("enp0s25"))))
15558 @deftp {Data Type} dhcpd-configuration
15560 @item @code{package} (default: @code{isc-dhcp})
15561 The package that provides the DHCP daemon. This package is expected to
15562 provide the daemon at @file{sbin/dhcpd} relative to its output
15563 directory. The default package is the
15564 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
15565 @item @code{config-file} (default: @code{#f})
15566 The configuration file to use. This is required. It will be passed to
15567 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
15568 object (@pxref{G-Expressions, file-like objects}). See @code{man
15569 dhcpd.conf} for details on the configuration file syntax.
15570 @item @code{version} (default: @code{"4"})
15571 The DHCP version to use. The ISC DHCP server supports the values ``4'',
15572 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
15573 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
15575 @item @code{run-directory} (default: @code{"/run/dhcpd"})
15576 The run directory to use. At service activation time, this directory
15577 will be created if it does not exist.
15578 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
15579 The PID file to use. This corresponds to the @code{-pf} option of
15580 @code{dhcpd}. See @code{man dhcpd} for details.
15581 @item @code{interfaces} (default: @code{'()})
15582 The names of the network interfaces on which dhcpd should listen for
15583 broadcasts. If this list is not empty, then its elements (which must be
15584 strings) will be appended to the @code{dhcpd} invocation when starting
15585 the daemon. It may not be necessary to explicitly specify any
15586 interfaces here; see @code{man dhcpd} for details.
15590 @defvr {Scheme Variable} static-networking-service-type
15591 This is the type for statically-configured network interfaces.
15592 @c TODO Document <static-networking> data structures.
15595 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
15596 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
15597 [#:requirement @code{'(udev)}]
15598 Return a service that starts @var{interface} with address @var{ip}. If
15599 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
15600 it must be a string specifying the default network gateway. @var{requirement}
15601 can be used to declare a dependency on another service before configuring the
15604 This procedure can be called several times, one for each network
15605 interface of interest. Behind the scenes what it does is extend
15606 @code{static-networking-service-type} with additional network interfaces
15612 (static-networking-service "eno1" "192.168.1.82"
15613 #:gateway "192.168.1.2"
15614 #:name-servers '("192.168.1.2"))
15621 @cindex network management
15622 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
15623 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
15624 management daemon that aims to simplify wired and wireless networking.
15626 This service adds the @var{wicd} package to the global profile, providing
15627 several commands to interact with the daemon and configure networking:
15628 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
15629 and @command{wicd-curses} user interfaces.
15632 @cindex ModemManager
15634 @defvr {Scheme Variable} modem-manager-service-type
15635 This is the service type for the
15636 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
15637 service. The value for this service type is a
15638 @code{modem-manager-configuration} record.
15640 This service is part of @code{%desktop-services} (@pxref{Desktop
15644 @deftp {Data Type} modem-manager-configuration
15645 Data type representing the configuration of ModemManager.
15648 @item @code{modem-manager} (default: @code{modem-manager})
15649 The ModemManager package to use.
15654 @cindex USB_ModeSwitch
15655 @cindex Modeswitching
15657 @defvr {Scheme Variable} usb-modeswitch-service-type
15658 This is the service type for the
15659 @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch} service. The
15660 value for this service type is a @code{usb-modeswitch-configuration} record.
15662 When plugged in, some USB modems (and other USB devices) initially present
15663 themselves as a read-only storage medium and not as a modem. They need to be
15664 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
15665 installs udev rules to automatically modeswitch these devices when they are
15668 This service is part of @code{%desktop-services} (@pxref{Desktop
15672 @deftp {Data Type} usb-modeswitch-configuration
15673 Data type representing the configuration of USB_ModeSwitch.
15676 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
15677 The USB_ModeSwitch package providing the binaries for modeswitching.
15679 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
15680 The package providing the device data and udev rules file used by
15683 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
15684 Which config file to use for the USB_ModeSwitch dispatcher. By default the
15685 config file shipped with USB_ModeSwitch is used which disables logging to
15686 @file{/var/log} among other default settings. If set to @code{#f}, no config
15692 @cindex NetworkManager
15694 @defvr {Scheme Variable} network-manager-service-type
15695 This is the service type for the
15696 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
15697 service. The value for this service type is a
15698 @code{network-manager-configuration} record.
15700 This service is part of @code{%desktop-services} (@pxref{Desktop
15704 @deftp {Data Type} network-manager-configuration
15705 Data type representing the configuration of NetworkManager.
15708 @item @code{network-manager} (default: @code{network-manager})
15709 The NetworkManager package to use.
15711 @item @code{dns} (default: @code{"default"})
15712 Processing mode for DNS, which affects how NetworkManager uses the
15713 @code{resolv.conf} configuration file.
15717 NetworkManager will update @code{resolv.conf} to reflect the nameservers
15718 provided by currently active connections.
15721 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
15722 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
15723 then update @code{resolv.conf} to point to the local nameserver.
15725 With this setting, you can share your network connection. For example when
15726 you want to share your network connection to another laptop @i{via} an
15727 Ethernet cable, you can open @command{nm-connection-editor} and configure the
15728 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
15729 and reestablish the connection (or reboot).
15731 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
15732 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
15733 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
15734 browser on your host system, or connect to the VM @i{via} SSH
15735 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
15736 host-to-guest connection, run this command once:
15739 nmcli connection add type tun \
15740 connection.interface-name tap0 \
15741 tun.mode tap tun.owner $(id -u) \
15742 ipv4.method shared \
15743 ipv4.addresses 172.28.112.1/24
15746 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
15747 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
15748 @command{qemu-system-...}.
15751 NetworkManager will not modify @code{resolv.conf}.
15754 @item @code{vpn-plugins} (default: @code{'()})
15755 This is the list of available plugins for virtual private networks
15756 (VPNs). An example of this is the @code{network-manager-openvpn}
15757 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
15763 @deffn {Scheme Variable} connman-service-type
15764 This is the service type to run @url{https://01.org/connman,Connman},
15765 a network connection manager.
15767 Its value must be an
15768 @code{connman-configuration} record as in this example:
15771 (service connman-service-type
15772 (connman-configuration
15773 (disable-vpn? #t)))
15776 See below for details about @code{connman-configuration}.
15779 @deftp {Data Type} connman-configuration
15780 Data Type representing the configuration of connman.
15783 @item @code{connman} (default: @var{connman})
15784 The connman package to use.
15786 @item @code{disable-vpn?} (default: @code{#f})
15787 When true, disable connman's vpn plugin.
15791 @cindex WPA Supplicant
15792 @defvr {Scheme Variable} wpa-supplicant-service-type
15793 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
15794 supplicant}, an authentication daemon required to authenticate against
15795 encrypted WiFi or ethernet networks.
15798 @deftp {Data Type} wpa-supplicant-configuration
15799 Data type representing the configuration of WPA Supplicant.
15801 It takes the following parameters:
15804 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
15805 The WPA Supplicant package to use.
15807 @item @code{requirement} (default: @code{'(user-processes loopback syslogd)}
15808 List of services that should be started before WPA Supplicant starts.
15810 @item @code{dbus?} (default: @code{#t})
15811 Whether to listen for requests on D-Bus.
15813 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
15814 Where to store the PID file.
15816 @item @code{interface} (default: @code{#f})
15817 If this is set, it must specify the name of a network interface that
15818 WPA supplicant will control.
15820 @item @code{config-file} (default: @code{#f})
15821 Optional configuration file to use.
15823 @item @code{extra-options} (default: @code{'()})
15824 List of additional command-line arguments to pass to the daemon.
15828 @cindex hostapd service, for Wi-Fi access points
15829 @cindex Wi-Fi access points, hostapd service
15830 @defvr {Scheme Variable} hostapd-service-type
15831 This is the service type to run the @uref{https://w1.fi/hostapd/,
15832 hostapd} daemon to set up WiFi (IEEE 802.11) access points and
15833 authentication servers. Its associated value must be a
15834 @code{hostapd-configuration} as shown below:
15837 ;; Use wlan1 to run the access point for "My Network".
15838 (service hostapd-service-type
15839 (hostapd-configuration
15840 (interface "wlan1")
15841 (ssid "My Network")
15846 @deftp {Data Type} hostapd-configuration
15847 This data type represents the configuration of the hostapd service, with
15848 the following fields:
15851 @item @code{package} (default: @code{hostapd})
15852 The hostapd package to use.
15854 @item @code{interface} (default: @code{"wlan0"})
15855 The network interface to run the WiFi access point.
15858 The SSID (@dfn{service set identifier}), a string that identifies this
15861 @item @code{broadcast-ssid?} (default: @code{#t})
15862 Whether to broadcast this SSID.
15864 @item @code{channel} (default: @code{1})
15865 The WiFi channel to use.
15867 @item @code{driver} (default: @code{"nl80211"})
15868 The driver interface type. @code{"nl80211"} is used with all Linux
15869 mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
15870 RADIUS server that does # not control any wireless/wired driver.
15872 @item @code{extra-settings} (default: @code{""})
15873 Extra settings to append as-is to the hostapd configuration file. See
15874 @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
15875 configuration file reference.
15879 @defvr {Scheme Variable} simulated-wifi-service-type
15880 This is the type of a service to simulate WiFi networking, which can be
15881 useful in virtual machines for testing purposes. The service loads the
15883 @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
15884 @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
15885 network that can be seen on @code{wlan0}, by default.
15887 The service's value is a @code{hostapd-configuration} record.
15891 @defvr {Scheme Variable} iptables-service-type
15892 This is the service type to set up an iptables configuration. iptables is a
15893 packet filtering framework supported by the Linux kernel. This service
15894 supports configuring iptables for both IPv4 and IPv6. A simple example
15895 configuration rejecting all incoming connections except those to the ssh port
15899 (service iptables-service-type
15900 (iptables-configuration
15901 (ipv4-rules (plain-file "iptables.rules" "*filter
15905 -A INPUT -p tcp --dport 22 -j ACCEPT
15906 -A INPUT -j REJECT --reject-with icmp-port-unreachable
15909 (ipv6-rules (plain-file "ip6tables.rules" "*filter
15913 -A INPUT -p tcp --dport 22 -j ACCEPT
15914 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
15920 @deftp {Data Type} iptables-configuration
15921 The data type representing the configuration of iptables.
15924 @item @code{iptables} (default: @code{iptables})
15925 The iptables package that provides @code{iptables-restore} and
15926 @code{ip6tables-restore}.
15927 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
15928 The iptables rules to use. It will be passed to @code{iptables-restore}.
15929 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
15931 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
15932 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
15933 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
15939 @defvr {Scheme Variable} nftables-service-type
15940 This is the service type to set up a nftables configuration. nftables is a
15941 netfilter project that aims to replace the existing iptables, ip6tables,
15942 arptables and ebtables framework. It provides a new packet filtering
15943 framework, a new user-space utility @command{nft}, and a compatibility layer
15944 for iptables. This service comes with a default ruleset
15945 @code{%default-nftables-ruleset} that rejecting all incomming connections
15946 except those to the ssh port 22. To use it, simply write:
15949 (service nftables-service-type)
15953 @deftp {Data Type} nftables-configuration
15954 The data type representing the configuration of nftables.
15957 @item @code{package} (default: @code{nftables})
15958 The nftables package that provides @command{nft}.
15959 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
15960 The nftables ruleset to use. This may be any ``file-like'' object
15961 (@pxref{G-Expressions, file-like objects}).
15965 @cindex NTP (Network Time Protocol), service
15966 @cindex ntpd, service for the Network Time Protocol daemon
15967 @cindex real time clock
15968 @defvr {Scheme Variable} ntp-service-type
15969 This is the type of the service running the @uref{https://www.ntp.org,
15970 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
15971 system clock synchronized with that of the specified NTP servers.
15973 The value of this service is an @code{ntpd-configuration} object, as described
15977 @deftp {Data Type} ntp-configuration
15978 This is the data type for the NTP service configuration.
15981 @item @code{servers} (default: @code{%ntp-servers})
15982 This is the list of servers (@code{<ntp-server>} records) with which
15983 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
15986 @item @code{allow-large-adjustment?} (default: @code{#t})
15987 This determines whether @command{ntpd} is allowed to make an initial
15988 adjustment of more than 1,000 seconds.
15990 @item @code{ntp} (default: @code{ntp})
15991 The NTP package to use.
15995 @defvr {Scheme Variable} %ntp-servers
15996 List of host names used as the default NTP servers. These are servers of the
15997 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
16000 @deftp {Data Type} ntp-server
16001 The data type representing the configuration of a NTP server.
16004 @item @code{type} (default: @code{'server})
16005 The type of the NTP server, given as a symbol. One of @code{'pool},
16006 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
16008 @item @code{address}
16009 The address of the server, as a string.
16011 @item @code{options}
16012 NTPD options to use with that specific server, given as a list of option names
16013 and/or of option names and values tuples. The following example define a server
16014 to use with the options @option{iburst} and @option{prefer}, as well as
16015 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
16020 (address "some.ntp.server.org")
16021 (options `(iburst (version 3) (maxpoll 16) prefer))))
16027 @deffn {Scheme Procedure} openntpd-service-type
16028 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
16029 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
16030 clock synchronized with that of the given servers.
16034 openntpd-service-type
16035 (openntpd-configuration
16036 (listen-on '("127.0.0.1" "::1"))
16037 (sensor '("udcf0 correction 70000"))
16038 (constraint-from '("www.gnu.org"))
16039 (constraints-from '("https://www.google.com/"))
16040 (allow-large-adjustment? #t)))
16045 @defvr {Scheme Variable} %openntpd-servers
16046 This variable is a list of the server addresses defined in
16047 @code{%ntp-servers}.
16050 @deftp {Data Type} openntpd-configuration
16052 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
16053 The openntpd executable to use.
16054 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
16055 A list of local IP addresses or hostnames the ntpd daemon should listen on.
16056 @item @code{query-from} (default: @code{'()})
16057 A list of local IP address the ntpd daemon should use for outgoing queries.
16058 @item @code{sensor} (default: @code{'()})
16059 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
16060 will listen to each sensor that actually exists and ignore non-existent ones.
16061 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
16063 @item @code{server} (default: @code{'()})
16064 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
16065 @item @code{servers} (default: @code{%openntp-servers})
16066 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
16067 @item @code{constraint-from} (default: @code{'()})
16068 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
16069 This time information is not used for precision but acts as an authenticated
16070 constraint, thereby reducing the impact of unauthenticated NTP
16071 man-in-the-middle attacks.
16072 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
16074 @item @code{constraints-from} (default: @code{'()})
16075 As with constraint from, specify a list of URLs, IP addresses or hostnames of
16076 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
16077 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
16078 @item @code{allow-large-adjustment?} (default: @code{#f})
16079 Determines if @code{ntpd} is allowed to make an initial adjustment of more
16085 @deffn {Scheme variable} inetd-service-type
16086 This service runs the @command{inetd} (@pxref{inetd invocation,,,
16087 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
16088 connections on internet sockets, and lazily starts the specified server
16089 program when a connection is made on one of these sockets.
16091 The value of this service is an @code{inetd-configuration} object. The
16092 following example configures the @command{inetd} daemon to provide the
16093 built-in @command{echo} service, as well as an smtp service which
16094 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
16095 gateway @code{hostname}:
16100 (inetd-configuration
16104 (socket-type 'stream)
16111 (socket-type 'stream)
16115 (program (file-append openssh "/bin/ssh"))
16117 '("ssh" "-qT" "-i" "/path/to/ssh_key"
16118 "-W" "smtp-server:25" "user@@hostname")))))))
16121 See below for more details about @code{inetd-configuration}.
16124 @deftp {Data Type} inetd-configuration
16125 Data type representing the configuration of @command{inetd}.
16128 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
16129 The @command{inetd} executable to use.
16131 @item @code{entries} (default: @code{'()})
16132 A list of @command{inetd} service entries. Each entry should be created
16133 by the @code{inetd-entry} constructor.
16137 @deftp {Data Type} inetd-entry
16138 Data type representing an entry in the @command{inetd} configuration.
16139 Each entry corresponds to a socket where @command{inetd} will listen for
16143 @item @code{node} (default: @code{#f})
16144 Optional string, a comma-separated list of local addresses
16145 @command{inetd} should use when listening for this service.
16146 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
16147 description of all options.
16149 A string, the name must correspond to an entry in @code{/etc/services}.
16150 @item @code{socket-type}
16151 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
16153 @item @code{protocol}
16154 A string, must correspond to an entry in @code{/etc/protocols}.
16155 @item @code{wait?} (default: @code{#t})
16156 Whether @command{inetd} should wait for the server to exit before
16157 listening to new service requests.
16159 A string containing the user (and, optionally, group) name of the user
16160 as whom the server should run. The group name can be specified in a
16161 suffix, separated by a colon or period, i.e.@: @code{"user"},
16162 @code{"user:group"} or @code{"user.group"}.
16163 @item @code{program} (default: @code{"internal"})
16164 The server program which will serve the requests, or @code{"internal"}
16165 if @command{inetd} should use a built-in service.
16166 @item @code{arguments} (default: @code{'()})
16167 A list strings or file-like objects, which are the server program's
16168 arguments, starting with the zeroth argument, i.e.@: the name of the
16169 program itself. For @command{inetd}'s internal services, this entry
16170 must be @code{'()} or @code{'("internal")}.
16173 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
16174 detailed discussion of each configuration field.
16178 @defvr {Scheme Variable} tor-service-type
16179 This is the type for a service that runs the @uref{https://torproject.org,
16180 Tor} anonymous networking daemon. The service is configured using a
16181 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
16182 @code{tor} unprivileged user, which is a member of the @code{tor} group.
16186 @deftp {Data Type} tor-configuration
16188 @item @code{tor} (default: @code{tor})
16189 The package that provides the Tor daemon. This package is expected to provide
16190 the daemon at @file{bin/tor} relative to its output directory. The default
16191 package is the @uref{https://www.torproject.org, Tor Project's}
16194 @item @code{config-file} (default: @code{(plain-file "empty" "")})
16195 The configuration file to use. It will be appended to a default configuration
16196 file, and the final configuration file will be passed to @code{tor} via its
16197 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
16198 file-like objects}). See @code{man tor} for details on the configuration file
16201 @item @code{hidden-services} (default: @code{'()})
16202 The list of @code{<hidden-service>} records to use. For any hidden service
16203 you include in this list, appropriate configuration to enable the hidden
16204 service will be automatically added to the default configuration file. You
16205 may conveniently create @code{<hidden-service>} records using the
16206 @code{tor-hidden-service} procedure described below.
16208 @item @code{socks-socket-type} (default: @code{'tcp})
16209 The default socket type that Tor should use for its SOCKS socket. This must
16210 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
16211 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
16212 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
16213 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
16216 If you want to customize the SOCKS socket in more detail, leave
16217 @code{socks-socket-type} at its default value of @code{'tcp} and use
16218 @code{config-file} to override the default by providing your own
16219 @code{SocksPort} option.
16223 @cindex hidden service
16224 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
16225 Define a new Tor @dfn{hidden service} called @var{name} and implementing
16226 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
16229 '((22 "127.0.0.1:22")
16230 (80 "127.0.0.1:8080"))
16233 In this example, port 22 of the hidden service is mapped to local port 22, and
16234 port 80 is mapped to local port 8080.
16236 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
16237 the @file{hostname} file contains the @code{.onion} host name for the hidden
16240 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
16241 project's documentation} for more information.
16244 The @code{(gnu services rsync)} module provides the following services:
16246 You might want an rsync daemon if you have files that you want available
16247 so anyone (or just yourself) can download existing files or upload new
16250 @deffn {Scheme Variable} rsync-service-type
16251 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
16252 The value for this service type is a
16253 @command{rsync-configuration} record as in this example:
16256 (service rsync-service-type)
16259 See below for details about @code{rsync-configuration}.
16262 @deftp {Data Type} rsync-configuration
16263 Data type representing the configuration for @code{rsync-service}.
16266 @item @code{package} (default: @var{rsync})
16267 @code{rsync} package to use.
16269 @item @code{port-number} (default: @code{873})
16270 TCP port on which @command{rsync} listens for incoming connections. If port
16271 is less than @code{1024} @command{rsync} needs to be started as the
16272 @code{root} user and group.
16274 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
16275 Name of the file where @command{rsync} writes its PID.
16277 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
16278 Name of the file where @command{rsync} writes its lock file.
16280 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
16281 Name of the file where @command{rsync} writes its log file.
16283 @item @code{use-chroot?} (default: @var{#t})
16284 Whether to use chroot for @command{rsync} shared directory.
16286 @item @code{share-path} (default: @file{/srv/rsync})
16287 Location of the @command{rsync} shared directory.
16289 @item @code{share-comment} (default: @code{"Rsync share"})
16290 Comment of the @command{rsync} shared directory.
16292 @item @code{read-only?} (default: @var{#f})
16293 Read-write permissions to shared directory.
16295 @item @code{timeout} (default: @code{300})
16296 I/O timeout in seconds.
16298 @item @code{user} (default: @var{"root"})
16299 Owner of the @code{rsync} process.
16301 @item @code{group} (default: @var{"root"})
16302 Group of the @code{rsync} process.
16304 @item @code{uid} (default: @var{"rsyncd"})
16305 User name or user ID that file transfers to and from that module should take
16306 place as when the daemon was run as @code{root}.
16308 @item @code{gid} (default: @var{"rsyncd"})
16309 Group name or group ID that will be used when accessing the module.
16314 Furthermore, @code{(gnu services ssh)} provides the following services.
16318 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
16319 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
16320 [#:allow-empty-passwords? #f] [#:root-login? #f] @
16321 [#:syslog-output? #t] [#:x11-forwarding? #t] @
16322 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
16323 [#:public-key-authentication? #t] [#:initialize? #t]
16324 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
16325 @var{host-key} must designate a file containing the host key, and readable
16328 When @var{daemonic?} is true, @command{lshd} will detach from the
16329 controlling terminal and log its output to syslogd, unless one sets
16330 @var{syslog-output?} to false. Obviously, it also makes lsh-service
16331 depend on existence of syslogd service. When @var{pid-file?} is true,
16332 @command{lshd} writes its PID to the file called @var{pid-file}.
16334 When @var{initialize?} is true, automatically create the seed and host key
16335 upon service activation if they do not exist yet. This may take long and
16336 require interaction.
16338 When @var{initialize?} is false, it is up to the user to initialize the
16339 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
16340 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
16341 basics,,, lsh, LSH Manual}).
16343 When @var{interfaces} is empty, lshd listens for connections on all the
16344 network interfaces; otherwise, @var{interfaces} must be a list of host names
16347 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
16348 passwords, and @var{root-login?} specifies whether to accept log-ins as
16351 The other options should be self-descriptive.
16356 @deffn {Scheme Variable} openssh-service-type
16357 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
16358 shell daemon, @command{sshd}. Its value must be an
16359 @code{openssh-configuration} record as in this example:
16362 (service openssh-service-type
16363 (openssh-configuration
16364 (x11-forwarding? #t)
16365 (permit-root-login 'without-password)
16367 `(("alice" ,(local-file "alice.pub"))
16368 ("bob" ,(local-file "bob.pub"))))))
16371 See below for details about @code{openssh-configuration}.
16373 This service can be extended with extra authorized keys, as in this
16377 (service-extension openssh-service-type
16378 (const `(("charlie"
16379 ,(local-file "charlie.pub")))))
16383 @deftp {Data Type} openssh-configuration
16384 This is the configuration record for OpenSSH's @command{sshd}.
16387 @item @code{openssh} (default @var{openssh})
16388 The Openssh package to use.
16390 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
16391 Name of the file where @command{sshd} writes its PID.
16393 @item @code{port-number} (default: @code{22})
16394 TCP port on which @command{sshd} listens for incoming connections.
16396 @item @code{permit-root-login} (default: @code{#f})
16397 This field determines whether and when to allow logins as root. If
16398 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
16399 If it's the symbol @code{'without-password}, then root logins are
16400 permitted but not with password-based authentication.
16402 @item @code{allow-empty-passwords?} (default: @code{#f})
16403 When true, users with empty passwords may log in. When false, they may
16406 @item @code{password-authentication?} (default: @code{#t})
16407 When true, users may log in with their password. When false, they have
16408 other authentication methods.
16410 @item @code{public-key-authentication?} (default: @code{#t})
16411 When true, users may log in using public key authentication. When
16412 false, users have to use other authentication method.
16414 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
16415 This is used only by protocol version 2.
16417 @item @code{x11-forwarding?} (default: @code{#f})
16418 When true, forwarding of X11 graphical client connections is
16419 enabled---in other words, @command{ssh} options @option{-X} and
16420 @option{-Y} will work.
16422 @item @code{allow-agent-forwarding?} (default: @code{#t})
16423 Whether to allow agent forwarding.
16425 @item @code{allow-tcp-forwarding?} (default: @code{#t})
16426 Whether to allow TCP forwarding.
16428 @item @code{gateway-ports?} (default: @code{#f})
16429 Whether to allow gateway ports.
16431 @item @code{challenge-response-authentication?} (default: @code{#f})
16432 Specifies whether challenge response authentication is allowed (e.g.@: via
16435 @item @code{use-pam?} (default: @code{#t})
16436 Enables the Pluggable Authentication Module interface. If set to
16437 @code{#t}, this will enable PAM authentication using
16438 @code{challenge-response-authentication?} and
16439 @code{password-authentication?}, in addition to PAM account and session
16440 module processing for all authentication types.
16442 Because PAM challenge response authentication usually serves an
16443 equivalent role to password authentication, you should disable either
16444 @code{challenge-response-authentication?} or
16445 @code{password-authentication?}.
16447 @item @code{print-last-log?} (default: @code{#t})
16448 Specifies whether @command{sshd} should print the date and time of the
16449 last user login when a user logs in interactively.
16451 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
16452 Configures external subsystems (e.g.@: file transfer daemon).
16454 This is a list of two-element lists, each of which containing the
16455 subsystem name and a command (with optional arguments) to execute upon
16458 The command @command{internal-sftp} implements an in-process SFTP
16459 server. Alternatively, one can specify the @command{sftp-server} command:
16461 (service openssh-service-type
16462 (openssh-configuration
16464 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
16467 @item @code{accepted-environment} (default: @code{'()})
16468 List of strings describing which environment variables may be exported.
16470 Each string gets on its own line. See the @code{AcceptEnv} option in
16471 @code{man sshd_config}.
16473 This example allows ssh-clients to export the @env{COLORTERM} variable.
16474 It is set by terminal emulators, which support colors. You can use it in
16475 your shell's resource file to enable colors for the prompt and commands
16476 if this variable is set.
16479 (service openssh-service-type
16480 (openssh-configuration
16481 (accepted-environment '("COLORTERM"))))
16484 @item @code{authorized-keys} (default: @code{'()})
16485 @cindex authorized keys, SSH
16486 @cindex SSH authorized keys
16487 This is the list of authorized keys. Each element of the list is a user
16488 name followed by one or more file-like objects that represent SSH public
16492 (openssh-configuration
16494 `(("rekado" ,(local-file "rekado.pub"))
16495 ("chris" ,(local-file "chris.pub"))
16496 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
16500 registers the specified public keys for user accounts @code{rekado},
16501 @code{chris}, and @code{root}.
16503 Additional authorized keys can be specified @i{via}
16504 @code{service-extension}.
16506 Note that this does @emph{not} interfere with the use of
16507 @file{~/.ssh/authorized_keys}.
16509 @item @code{log-level} (default: @code{'info})
16510 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
16511 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
16512 page for @file{sshd_config} for the full list of level names.
16514 @item @code{extra-content} (default: @code{""})
16515 This field can be used to append arbitrary text to the configuration file. It
16516 is especially useful for elaborate configurations that cannot be expressed
16517 otherwise. This configuration, for example, would generally disable root
16518 logins, but permit them from one specific IP address:
16521 (openssh-configuration
16523 Match Address 192.168.0.1
16524 PermitRootLogin yes"))
16530 @deffn {Scheme Procedure} dropbear-service [@var{config}]
16531 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
16532 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
16535 For example, to specify a Dropbear service listening on port 1234, add
16536 this call to the operating system's @code{services} field:
16539 (dropbear-service (dropbear-configuration
16540 (port-number 1234)))
16544 @deftp {Data Type} dropbear-configuration
16545 This data type represents the configuration of a Dropbear SSH daemon.
16548 @item @code{dropbear} (default: @var{dropbear})
16549 The Dropbear package to use.
16551 @item @code{port-number} (default: 22)
16552 The TCP port where the daemon waits for incoming connections.
16554 @item @code{syslog-output?} (default: @code{#t})
16555 Whether to enable syslog output.
16557 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
16558 File name of the daemon's PID file.
16560 @item @code{root-login?} (default: @code{#f})
16561 Whether to allow @code{root} logins.
16563 @item @code{allow-empty-passwords?} (default: @code{#f})
16564 Whether to allow empty passwords.
16566 @item @code{password-authentication?} (default: @code{#t})
16567 Whether to enable password-based authentication.
16572 @deffn {Scheme Variable} autossh-service-type
16573 This is the type for the @uref{https://www.harding.motd.ca/autossh,
16574 AutoSSH} program that runs a copy of @command{ssh} and monitors it,
16575 restarting it as necessary should it die or stop passing traffic.
16576 AutoSSH can be run manually from the command-line by passing arguments
16577 to the binary @command{autossh} from the package @code{autossh}, but it
16578 can also be run as a Guix service. This latter use case is documented
16581 AutoSSH can be used to forward local traffic to a remote machine using
16582 an SSH tunnel, and it respects the @file{~/.ssh/config} of the user it
16585 For example, to specify a service running autossh as the user
16586 @code{pino} and forwarding all local connections to port @code{8081} to
16587 @code{remote:8081} using an SSH tunnel, add this call to the operating
16588 system's @code{services} field:
16591 (service autossh-service-type
16592 (autossh-configuration
16594 (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
16598 @deftp {Data Type} autossh-configuration
16599 This data type represents the configuration of an AutoSSH service.
16603 @item @code{user} (default @code{"autossh"})
16604 The user as which the AutoSSH service is to be run.
16605 This assumes that the specified user exists.
16607 @item @code{poll} (default @code{600})
16608 Specifies the connection poll time in seconds.
16610 @item @code{first-poll} (default @code{#f})
16611 Specifies how many seconds AutoSSH waits before the first connection
16612 test. After this first test, polling is resumed at the pace defined in
16613 @code{poll}. When set to @code{#f}, the first poll is not treated
16614 specially and will also use the connection poll specified in
16617 @item @code{gate-time} (default @code{30})
16618 Specifies how many seconds an SSH connection must be active before it is
16619 considered successful.
16621 @item @code{log-level} (default @code{1})
16622 The log level, corresponding to the levels used by syslog---so @code{0}
16623 is the most silent while @code{7} is the chattiest.
16625 @item @code{max-start} (default @code{#f})
16626 The maximum number of times SSH may be (re)started before AutoSSH exits.
16627 When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
16629 @item @code{message} (default @code{""})
16630 The message to append to the echo message sent when testing connections.
16632 @item @code{port} (default @code{"0"})
16633 The ports used for monitoring the connection. When set to @code{"0"},
16634 monitoring is disabled. When set to @code{"@var{n}"} where @var{n} is
16635 a positive integer, ports @var{n} and @var{n}+1 are used for
16636 monitoring the connection, such that port @var{n} is the base
16637 monitoring port and @code{n+1} is the echo port. When set to
16638 @code{"@var{n}:@var{m}"} where @var{n} and @var{m} are positive
16639 integers, the ports @var{n} and @var{m} are used for monitoring the
16640 connection, such that port @var{n} is the base monitoring port and
16641 @var{m} is the echo port.
16643 @item @code{ssh-options} (default @code{'()})
16644 The list of command-line arguments to pass to @command{ssh} when it is
16645 run. Options @option{-f} and @option{-M} are reserved for AutoSSH and
16646 may cause undefined behaviour.
16652 @deffn {Scheme Variable} webssh-service-type
16653 This is the type for the @uref{https://webssh.huashengdun.org/, WebSSH}
16654 program that runs a web SSH client. WebSSH can be run manually from the
16655 command-line by passing arguments to the binary @command{wssh} from the
16656 package @code{webssh}, but it can also be run as a Guix service. This
16657 latter use case is documented here.
16659 For example, to specify a service running WebSSH on loopback interface
16660 on port @code{8888} with reject policy with a list of allowed to
16661 connection hosts, and NGINX as a reverse-proxy to this service listening
16662 for HTTPS connection, add this call to the operating system's
16663 @code{services} field:
16666 (service webssh-service-type
16667 (webssh-configuration (address "127.0.0.1")
16670 (known-hosts '("localhost ecdsa-sha2-nistp256 AAAA…"
16671 "127.0.0.1 ecdsa-sha2-nistp256 AAAA…"))))
16673 (service nginx-service-type
16674 (nginx-configuration
16677 (nginx-server-configuration
16678 (inherit %webssh-configuration-nginx)
16679 (server-name '("webssh.example.com"))
16680 (listen '("443 ssl"))
16681 (ssl-certificate (letsencrypt-certificate "webssh.example.com"))
16682 (ssl-certificate-key (letsencrypt-key "webssh.example.com"))
16684 (cons (nginx-location-configuration
16685 (uri "/.well-known")
16686 (body '("root /var/www;")))
16687 (nginx-server-configuration-locations %webssh-configuration-nginx))))))))
16691 @deftp {Data Type} webssh-configuration
16692 Data type representing the configuration for @code{webssh-service}.
16695 @item @code{package} (default: @var{webssh})
16696 @code{webssh} package to use.
16698 @item @code{user-name} (default: @var{"webssh"})
16699 User name or user ID that file transfers to and from that module should take
16702 @item @code{group-name} (default: @var{"webssh"})
16703 Group name or group ID that will be used when accessing the module.
16705 @item @code{address} (default: @var{#f})
16706 IP address on which @command{webssh} listens for incoming connections.
16708 @item @code{port} (default: @var{8888})
16709 TCP port on which @command{webssh} listens for incoming connections.
16711 @item @code{policy} (default: @var{#f})
16712 Connection policy. @var{reject} policy requires to specify @var{known-hosts}.
16714 @item @code{known-hosts} (default: @var{'()})
16715 List of hosts which allowed for SSH connection from @command{webssh}.
16717 @item @code{log-file} (default: @file{"/var/log/webssh.log"})
16718 Name of the file where @command{rsync} writes its log file.
16720 @item @code{log-level} (default: @var{#f})
16726 @defvr {Scheme Variable} %facebook-host-aliases
16727 This variable contains a string for use in @file{/etc/hosts}
16728 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
16729 line contains a entry that maps a known server name of the Facebook
16730 on-line service---e.g., @code{www.facebook.com}---to the local
16731 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
16733 This variable is typically used in the @code{hosts-file} field of an
16734 @code{operating-system} declaration (@pxref{operating-system Reference,
16735 @file{/etc/hosts}}):
16738 (use-modules (gnu) (guix))
16741 (host-name "mymachine")
16744 ;; Create a /etc/hosts file with aliases for "localhost"
16745 ;; and "mymachine", as well as for Facebook servers.
16746 (plain-file "hosts"
16747 (string-append (local-host-aliases host-name)
16748 %facebook-host-aliases))))
16751 This mechanism can prevent programs running locally, such as Web
16752 browsers, from accessing Facebook.
16755 The @code{(gnu services avahi)} provides the following definition.
16757 @defvr {Scheme Variable} avahi-service-type
16758 This is the service that runs @command{avahi-daemon}, a system-wide
16759 mDNS/DNS-SD responder that allows for service discovery and
16760 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
16761 Its value must be an @code{avahi-configuration} record---see below.
16763 This service extends the name service cache daemon (nscd) so that it can
16764 resolve @code{.local} host names using
16765 @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
16766 Service Switch}, for information on host name resolution.
16768 Additionally, add the @var{avahi} package to the system profile so that
16769 commands such as @command{avahi-browse} are directly usable.
16772 @deftp {Data Type} avahi-configuration
16773 Data type representation the configuration for Avahi.
16777 @item @code{host-name} (default: @code{#f})
16778 If different from @code{#f}, use that as the host name to
16779 publish for this machine; otherwise, use the machine's actual host name.
16781 @item @code{publish?} (default: @code{#t})
16782 When true, allow host names and services to be published (broadcast) over the
16785 @item @code{publish-workstation?} (default: @code{#t})
16786 When true, @command{avahi-daemon} publishes the machine's host name and IP
16787 address via mDNS on the local network. To view the host names published on
16788 your local network, you can run:
16791 avahi-browse _workstation._tcp
16794 @item @code{wide-area?} (default: @code{#f})
16795 When true, DNS-SD over unicast DNS is enabled.
16797 @item @code{ipv4?} (default: @code{#t})
16798 @itemx @code{ipv6?} (default: @code{#t})
16799 These fields determine whether to use IPv4/IPv6 sockets.
16801 @item @code{domains-to-browse} (default: @code{'()})
16802 This is a list of domains to browse.
16806 @deffn {Scheme Variable} openvswitch-service-type
16807 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
16808 service, whose value should be an @code{openvswitch-configuration}
16812 @deftp {Data Type} openvswitch-configuration
16813 Data type representing the configuration of Open vSwitch, a multilayer
16814 virtual switch which is designed to enable massive network automation
16815 through programmatic extension.
16818 @item @code{package} (default: @var{openvswitch})
16819 Package object of the Open vSwitch.
16824 @defvr {Scheme Variable} pagekite-service-type
16825 This is the service type for the @uref{https://pagekite.net, PageKite} service,
16826 a tunneling solution for making localhost servers publicly visible, even from
16827 behind restrictive firewalls or NAT without forwarded ports. The value for
16828 this service type is a @code{pagekite-configuration} record.
16830 Here's an example exposing the local HTTP and SSH daemons:
16833 (service pagekite-service-type
16834 (pagekite-configuration
16835 (kites '("http:@@kitename:localhost:80:@@kitesecret"
16836 "raw/22:@@kitename:localhost:22:@@kitesecret"))
16837 (extra-file "/etc/pagekite.rc")))
16841 @deftp {Data Type} pagekite-configuration
16842 Data type representing the configuration of PageKite.
16845 @item @code{package} (default: @var{pagekite})
16846 Package object of PageKite.
16848 @item @code{kitename} (default: @code{#f})
16849 PageKite name for authenticating to the frontend server.
16851 @item @code{kitesecret} (default: @code{#f})
16852 Shared secret for authenticating to the frontend server. You should probably
16853 put this inside @code{extra-file} instead.
16855 @item @code{frontend} (default: @code{#f})
16856 Connect to the named PageKite frontend server instead of the
16857 @uref{https://pagekite.net,,pagekite.net} service.
16859 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
16860 List of service kites to use. Exposes HTTP on port 80 by default. The format
16861 is @code{proto:kitename:host:port:secret}.
16863 @item @code{extra-file} (default: @code{#f})
16864 Extra configuration file to read, which you are expected to create manually.
16865 Use this to add additional options and manage shared secrets out-of-band.
16870 @defvr {Scheme Variable} yggdrasil-service-type
16871 The service type for connecting to the @uref{https://yggdrasil-network.github.io/,
16872 Yggdrasil network}, an early-stage implementation of a fully end-to-end
16873 encrypted IPv6 network.
16876 Yggdrasil provides name-independent routing with cryptographically generated
16877 addresses. Static addressing means you can keep the same address as long as
16878 you want, even if you move to a new location, or generate a new address (by
16879 generating new keys) whenever you want.
16880 @uref{https://yggdrasil-network.github.io/2018/07/28/addressing.html}
16883 Pass it a value of @code{yggdrasil-configuration} to connect it to public
16884 peers and/or local peers.
16886 Here is an example using public peers and a static address. The static
16887 signing and encryption keys are defined in @file{/etc/yggdrasil-private.conf}
16888 (the default value for @code{config-file}).
16891 ;; part of the operating-system declaration
16892 (service yggdrasil-service-type
16893 (yggdrasil-configuration
16894 (autoconf? #f) ;; use only the public peers
16897 ;; https://github.com/yggdrasil-network/public-peers
16898 '((peers . #("tcp://1.2.3.4:1337"))))
16899 ;; /etc/yggdrasil-private.conf is the default value for config-file
16903 # sample content for /etc/yggdrasil-private.conf
16905 # Your public encryption key. Your peers may ask you for this to put
16906 # into their AllowedEncryptionPublicKeys configuration.
16907 EncryptionPublicKey: 378dc5...
16909 # Your private encryption key. DO NOT share this with anyone!
16910 EncryptionPrivateKey: 0777...
16912 # Your public signing key. You should not ordinarily need to share
16913 # this with anyone.
16914 SigningPublicKey: e1664...
16916 # Your private signing key. DO NOT share this with anyone!
16917 SigningPrivateKey: 0589d...
16922 @deftp {Data Type} yggdrasil-configuration
16923 Data type representing the configuration of Yggdrasil.
16926 @item @code{package} (default: @code{yggdrasil})
16927 Package object of Yggdrasil.
16929 @item @code{json-config} (default: @code{'()})
16930 Contents of @file{/etc/yggdrasil.conf}. Will be merged with
16931 @file{/etc/yggdrasil-private.conf}. Note that these settings are stored in
16932 the Guix store, which is readable to all users. @strong{Do not store your
16933 private keys in it}. See the output of @code{yggdrasil -genconf} for a
16934 quick overview of valid keys and their default values.
16936 @item @code{autoconf?} (default: @code{#f})
16937 Whether to use automatic mode. Enabling it makes Yggdrasil use adynamic IP
16938 and peer with IPv6 neighbors.
16940 @item @code{log-level} (default: @code{'info})
16941 How much detail to include in logs. Use @code{'debug} for more detail.
16943 @item @code{log-to} (default: @code{'stdout})
16944 Where to send logs. By default, the service logs standard output to
16945 @file{/var/log/yggdrasil.log}. The alternative is @code{'syslog}, which
16946 sends output to the running syslog service.
16948 @item @code{config-file} (default: @code{"/etc/yggdrasil-private.conf"})
16949 What HJSON file to load sensitive data from. This is where private keys
16950 should be stored, which are necessary to specify if you don't want a
16951 randomized address after each restart. Use @code{#f} to disable. Options
16952 defined in this file take precedence over @code{json-config}. Use the output
16953 of @code{yggdrasil -genconf} as a starting point. To configure a static
16954 address, delete everything except these options:
16957 @item @code{EncryptionPublicKey}
16958 @item @code{EncryptionPrivateKey}
16959 @item @code{SigningPublicKey}
16960 @item @code{SigningPrivateKey}
16965 @node Unattended Upgrades
16966 @subsection Unattended Upgrades
16968 @cindex unattended upgrades
16969 @cindex upgrades, unattended
16970 Guix provides a service to perform @emph{unattended upgrades}:
16971 periodically, the system automatically reconfigures itself from the
16972 latest Guix. Guix System has several properties that make unattended
16977 upgrades are transactional (either the upgrade succeeds or it fails, but
16978 you cannot end up with an ``in-between'' system state);
16980 the upgrade log is kept---you can view it with @command{guix system
16981 list-generations}---and you can roll back to any previous generation,
16982 should the upgraded system fail to behave as intended;
16984 channel code is authenticated so you know you can only run genuine code
16985 (@pxref{Channels});
16987 @command{guix system reconfigure} prevents downgrades, which makes it
16988 immune to @dfn{downgrade attacks}.
16991 To set up unattended upgrades, add an instance of
16992 @code{unattended-upgrade-service-type} like the one below to the list of
16993 your operating system services:
16996 (service unattended-upgrade-service-type)
16999 The defaults above set up weekly upgrades: every Sunday at midnight.
17000 You do not need to provide the operating system configuration file: it
17001 uses @file{/run/current-system/configuration.scm}, which ensures it
17002 always uses your latest configuration---@pxref{provenance-service-type},
17003 for more information about this file.
17005 There are several things that can be configured, in particular the
17006 periodicity and services (daemons) to be restarted upon completion.
17007 When the upgrade is successful, the service takes care of deleting
17008 system generations older that some threshold, as per @command{guix
17009 system delete-generations}. See the reference below for details.
17011 To ensure that upgrades are actually happening, you can run
17012 @command{guix system describe}. To investigate upgrade failures, visit
17013 the unattended upgrade log file (see below).
17015 @defvr {Scheme Variable} unattended-upgrade-service-type
17016 This is the service type for unattended upgrades. It sets up an mcron
17017 job (@pxref{Scheduled Job Execution}) that runs @command{guix system
17018 reconfigure} from the latest version of the specified channels.
17020 Its value must be a @code{unattended-upgrade-configuration} record (see
17024 @deftp {Data Type} unattended-upgrade-configuration
17025 This data type represents the configuration of the unattended upgrade
17026 service. The following fields are available:
17029 @item @code{schedule} (default: @code{"30 01 * * 0"})
17030 This is the schedule of upgrades, expressed as a gexp containing an
17031 mcron job schedule (@pxref{Guile Syntax, mcron job specifications,,
17032 mcron, GNU@tie{}mcron}).
17034 @item @code{channels} (default: @code{#~%default-channels})
17035 This gexp specifies the channels to use for the upgrade
17036 (@pxref{Channels}). By default, the tip of the official @code{guix}
17039 @item @code{operating-system-file} (default: @code{"/run/current-system/configuration.scm"})
17040 This field specifies the operating system configuration file to use.
17041 The default is to reuse the config file of the current configuration.
17043 There are cases, though, where referring to
17044 @file{/run/current-system/configuration.scm} is not enough, for instance
17045 because that file refers to extra files (SSH public keys, extra
17046 configuration files, etc.) @i{via} @code{local-file} and similar
17047 constructs. For those cases, we recommend something along these lines:
17050 (unattended-upgrade-configuration
17051 (operating-system-file
17052 (file-append (local-file "." "config-dir" #:recursive? #t)
17056 The effect here is to import all of the current directory into the
17057 store, and to refer to @file{config.scm} within that directory.
17058 Therefore, uses of @code{local-file} within @file{config.scm} will work
17059 as expected. @xref{G-Expressions}, for information about
17060 @code{local-file} and @code{file-append}.
17062 @item @code{services-to-restart} (default: @code{'(mcron)})
17063 This field specifies the Shepherd services to restart when the upgrade
17066 Those services are restarted right away upon completion, as with
17067 @command{herd restart}, which ensures that the latest version is
17068 running---remember that by default @command{guix system reconfigure}
17069 only restarts services that are not currently running, which is
17070 conservative: it minimizes disruption but leaves outdated services
17073 By default, the @code{mcron} service is restarted. This ensures that
17074 the latest version of the unattended upgrade job will be used next time.
17076 @item @code{system-expiration} (default: @code{(* 3 30 24 3600)})
17077 This is the expiration time in seconds for system generations. System
17078 generations older that this amount of time are deleted with
17079 @command{guix system delete-generations} when an upgrade completes.
17082 The unattended upgrade service does not run the garbage collector. You
17083 will probably want to set up your own mcron job to run @command{guix gc}
17087 @item @code{maximum-duration} (default: @code{3600})
17088 Maximum duration in seconds for the upgrade; past that time, the upgrade
17091 This is primarily useful to ensure the upgrade does not end up
17092 rebuilding or re-downloading ``the world''.
17094 @item @code{log-file} (default: @code{"/var/log/unattended-upgrade.log"})
17095 File where unattended upgrades are logged.
17100 @subsection X Window
17103 @cindex X Window System
17104 @cindex login manager
17105 Support for the X Window graphical display system---specifically
17106 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
17107 there is no @code{xorg-service} procedure. Instead, the X server is
17108 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
17111 @cindex GNOME, login manager
17112 GDM of course allows users to log in into window managers and desktop
17113 environments other than GNOME; for those using GNOME, GDM is required for
17114 features such as automatic screen locking.
17116 @cindex window manager
17117 To use X11, you must install at least one @dfn{window manager}---for
17118 example the @code{windowmaker} or @code{openbox} packages---preferably
17119 by adding it to the @code{packages} field of your operating system
17120 definition (@pxref{operating-system Reference, system-wide packages}).
17122 @defvr {Scheme Variable} gdm-service-type
17123 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
17124 Desktop Manager} (GDM), a program that manages graphical display servers and
17125 handles graphical user logins. Its value must be a @code{gdm-configuration}
17128 @cindex session types (X11)
17129 @cindex X11 session types
17130 GDM looks for @dfn{session types} described by the @file{.desktop} files in
17131 @file{/run/current-system/profile/share/xsessions} and allows users to choose
17132 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
17133 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
17134 set of packages automatically makes them available at the log-in screen.
17136 In addition, @file{~/.xsession} files are honored. When available,
17137 @file{~/.xsession} must be an executable that starts a window manager
17138 and/or other X clients.
17141 @deftp {Data Type} gdm-configuration
17143 @item @code{auto-login?} (default: @code{#f})
17144 @itemx @code{default-user} (default: @code{#f})
17145 When @code{auto-login?} is false, GDM presents a log-in screen.
17147 When @code{auto-login?} is true, GDM logs in directly as
17148 @code{default-user}.
17150 @item @code{debug?} (default: @code{#f})
17151 When true, GDM writes debug messages to its log.
17153 @item @code{gnome-shell-assets} (default: ...)
17154 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
17156 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
17157 Configuration of the Xorg graphical server.
17159 @item @code{xsession} (default: @code{(xinitrc)})
17160 Script to run before starting a X session.
17162 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
17163 File name of the @code{dbus-daemon} executable.
17165 @item @code{gdm} (default: @code{gdm})
17166 The GDM package to use.
17170 @defvr {Scheme Variable} slim-service-type
17171 This is the type for the SLiM graphical login manager for X11.
17173 Like GDM, SLiM looks for session types described by @file{.desktop} files and
17174 allows users to choose a session from the log-in screen using @kbd{F1}. It
17175 also honors @file{~/.xsession} files.
17177 Unlike GDM, SLiM does not spawn the user session on a different VT after
17178 logging in, which means that you can only start one graphical session. If you
17179 want to be able to run multiple graphical sessions at the same time you have
17180 to add multiple SLiM services to your system services. The following example
17181 shows how to replace the default GDM service with two SLiM services on tty7
17185 (use-modules (gnu services)
17186 (gnu services desktop)
17187 (gnu services xorg)
17188 (srfi srfi-1)) ;for 'remove'
17192 (services (cons* (service slim-service-type (slim-configuration
17195 (service slim-service-type (slim-configuration
17198 (remove (lambda (service)
17199 (eq? (service-kind service) gdm-service-type))
17200 %desktop-services))))
17205 @deftp {Data Type} slim-configuration
17206 Data type representing the configuration of @code{slim-service-type}.
17209 @item @code{allow-empty-passwords?} (default: @code{#t})
17210 Whether to allow logins with empty passwords.
17212 @item @code{auto-login?} (default: @code{#f})
17213 @itemx @code{default-user} (default: @code{""})
17214 When @code{auto-login?} is false, SLiM presents a log-in screen.
17216 When @code{auto-login?} is true, SLiM logs in directly as
17217 @code{default-user}.
17219 @item @code{theme} (default: @code{%default-slim-theme})
17220 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
17221 The graphical theme to use and its name.
17223 @item @code{auto-login-session} (default: @code{#f})
17224 If true, this must be the name of the executable to start as the default
17225 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
17227 If false, a session described by one of the available @file{.desktop}
17228 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
17232 You must install at least one window manager in the system profile or in
17233 your user profile. Failing to do that, if @code{auto-login-session} is
17234 false, you will be unable to log in.
17237 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
17238 Configuration of the Xorg graphical server.
17240 @item @code{display} (default @code{":0"})
17241 The display on which to start the Xorg graphical server.
17243 @item @code{vt} (default @code{"vt7"})
17244 The VT on which to start the Xorg graphical server.
17246 @item @code{xauth} (default: @code{xauth})
17247 The XAuth package to use.
17249 @item @code{shepherd} (default: @code{shepherd})
17250 The Shepherd package used when invoking @command{halt} and
17253 @item @code{sessreg} (default: @code{sessreg})
17254 The sessreg package used in order to register the session.
17256 @item @code{slim} (default: @code{slim})
17257 The SLiM package to use.
17261 @defvr {Scheme Variable} %default-theme
17262 @defvrx {Scheme Variable} %default-theme-name
17263 The default SLiM theme and its name.
17267 @deftp {Data Type} sddm-configuration
17268 This is the data type representing the SDDM service configuration.
17271 @item @code{display-server} (default: "x11")
17272 Select display server to use for the greeter. Valid values are
17273 @samp{"x11"} or @samp{"wayland"}.
17275 @item @code{numlock} (default: "on")
17276 Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
17278 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
17279 Command to run when halting.
17281 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
17282 Command to run when rebooting.
17284 @item @code{theme} (default "maldives")
17285 Theme to use. Default themes provided by SDDM are @samp{"elarun"},
17286 @samp{"maldives"} or @samp{"maya"}.
17288 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
17289 Directory to look for themes.
17291 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
17292 Directory to look for faces.
17294 @item @code{default-path} (default "/run/current-system/profile/bin")
17295 Default PATH to use.
17297 @item @code{minimum-uid} (default: 1000)
17298 Minimum UID displayed in SDDM and allowed for log-in.
17300 @item @code{maximum-uid} (default: 2000)
17301 Maximum UID to display in SDDM.
17303 @item @code{remember-last-user?} (default #t)
17304 Remember last user.
17306 @item @code{remember-last-session?} (default #t)
17307 Remember last session.
17309 @item @code{hide-users} (default "")
17310 Usernames to hide from SDDM greeter.
17312 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
17313 Users with shells listed will be hidden from the SDDM greeter.
17315 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
17316 Script to run before starting a wayland session.
17318 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
17319 Directory to look for desktop files starting wayland sessions.
17321 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
17322 Configuration of the Xorg graphical server.
17324 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
17327 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
17330 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
17331 Script to run after starting xorg-server.
17333 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
17334 Script to run before stopping xorg-server.
17336 @item @code{xsession-command} (default: @code{xinitrc})
17337 Script to run before starting a X session.
17339 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
17340 Directory to look for desktop files starting X sessions.
17342 @item @code{minimum-vt} (default: 7)
17345 @item @code{auto-login-user} (default "")
17346 User to use for auto-login.
17348 @item @code{auto-login-session} (default "")
17349 Desktop file to use for auto-login.
17351 @item @code{relogin?} (default #f)
17352 Relogin after logout.
17357 @cindex login manager
17359 @defvr {Scheme Variable} sddm-service-type
17360 This is the type of the service to run the
17361 @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
17362 must be a @code{sddm-configuration} record (see below).
17364 Here's an example use:
17367 (service sddm-service-type
17368 (sddm-configuration
17369 (auto-login-user "alice")
17370 (auto-login-session "xfce.desktop")))
17374 @deftp {Data Type} sddm-configuration
17375 This data type represents the configuration of the SDDM login manager.
17376 The available fields are:
17379 @item @code{sddm} (default: @code{sddm})
17380 The SDDM package to use.
17382 @item @code{display-server} (default: @code{"x11"})
17383 This must be either @code{"x11"} or @code{"wayland"}.
17385 @c FIXME: Add more fields.
17387 @item @code{auto-login-user} (default: @code{""})
17388 If non-empty, this is the user account under which to log in
17391 @item @code{auto-login-session} (default: @code{""})
17392 If non-empty, this is the @file{.desktop} file name to use as the
17393 auto-login session.
17397 @cindex Xorg, configuration
17398 @deftp {Data Type} xorg-configuration
17399 This data type represents the configuration of the Xorg graphical display
17400 server. Note that there is no Xorg service; instead, the X server is started
17401 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
17402 of these display managers aggregates an @code{xorg-configuration} record.
17405 @item @code{modules} (default: @code{%default-xorg-modules})
17406 This is a list of @dfn{module packages} loaded by the Xorg
17407 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
17409 @item @code{fonts} (default: @code{%default-xorg-fonts})
17410 This is a list of font directories to add to the server's @dfn{font path}.
17412 @item @code{drivers} (default: @code{'()})
17413 This must be either the empty list, in which case Xorg chooses a graphics
17414 driver automatically, or a list of driver names that will be tried in this
17415 order---e.g., @code{("modesetting" "vesa")}.
17417 @item @code{resolutions} (default: @code{'()})
17418 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
17419 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
17422 @cindex keyboard layout, for Xorg
17423 @cindex keymap, for Xorg
17424 @item @code{keyboard-layout} (default: @code{#f})
17425 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
17426 English (``qwerty'') for a 105-key PC keyboard.
17428 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
17429 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
17430 information on how to specify the keyboard layout.
17432 @item @code{extra-config} (default: @code{'()})
17433 This is a list of strings or objects appended to the configuration file. It
17434 is used to pass extra text to be added verbatim to the configuration file.
17436 @item @code{server} (default: @code{xorg-server})
17437 This is the package providing the Xorg server.
17439 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
17440 This is the list of command-line arguments to pass to the X server. The
17441 default is @code{-nolisten tcp}.
17445 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
17446 [@var{login-manager-service-type}]
17447 Tell the log-in manager (of type @var{login-manager-service-type}) to use
17448 @var{config}, an @code{<xorg-configuration>} record.
17450 Since the Xorg configuration is embedded in the log-in manager's
17451 configuration---e.g., @code{gdm-configuration}---this procedure provides a
17452 shorthand to set the Xorg configuration.
17455 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
17456 Return a @code{startx} script in which the modules, fonts, etc. specified
17457 in @var{config}, are available. The result should be used in place of
17460 Usually the X server is started by a login manager.
17464 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
17465 Add @var{package}, a package for a screen locker or screen saver whose
17466 command is @var{program}, to the set of setuid programs and add a PAM entry
17467 for it. For example:
17470 (screen-locker-service xlockmore "xlock")
17473 makes the good ol' XlockMore usable.
17477 @node Printing Services
17478 @subsection Printing Services
17480 @cindex printer support with CUPS
17481 The @code{(gnu services cups)} module provides a Guix service definition
17482 for the CUPS printing service. To add printer support to a Guix
17483 system, add a @code{cups-service} to the operating system definition:
17485 @deffn {Scheme Variable} cups-service-type
17486 The service type for the CUPS print server. Its value should be a valid
17487 CUPS configuration (see below). To use the default settings, simply
17490 (service cups-service-type)
17494 The CUPS configuration controls the basic things about your CUPS
17495 installation: what interfaces it listens on, what to do if a print job
17496 fails, how much logging to do, and so on. To actually add a printer,
17497 you have to visit the @url{http://localhost:631} URL, or use a tool such
17498 as GNOME's printer configuration services. By default, configuring a
17499 CUPS service will generate a self-signed certificate if needed, for
17500 secure connections to the print server.
17502 Suppose you want to enable the Web interface of CUPS and also add
17503 support for Epson printers @i{via} the @code{escpr} package and for HP
17504 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
17505 like this (you need to use the @code{(gnu packages cups)} module):
17508 (service cups-service-type
17509 (cups-configuration
17510 (web-interface? #t)
17512 (list cups-filters escpr hplip-minimal))))
17515 Note: If you wish to use the Qt5 based GUI which comes with the hplip
17516 package then it is suggested that you install the @code{hplip} package,
17517 either in your OS configuration file or as your user.
17519 The available configuration parameters follow. Each parameter
17520 definition is preceded by its type; for example, @samp{string-list foo}
17521 indicates that the @code{foo} parameter should be specified as a list of
17522 strings. There is also a way to specify the configuration as a string,
17523 if you have an old @code{cupsd.conf} file that you want to port over
17524 from some other system; see the end for more details.
17526 @c The following documentation was initially generated by
17527 @c (generate-documentation) in (gnu services cups). Manually maintained
17528 @c documentation is better, so we shouldn't hesitate to edit below as
17529 @c needed. However if the change you want to make to this documentation
17530 @c can be done in an automated way, it's probably easier to change
17531 @c (generate-documentation) than to make it below and have to deal with
17532 @c the churn as CUPS updates.
17535 Available @code{cups-configuration} fields are:
17537 @deftypevr {@code{cups-configuration} parameter} package cups
17541 @deftypevr {@code{cups-configuration} parameter} package-list extensions (default: @code{(list escpr hplip-minimal foomatic-filters)})
17542 Drivers and other extensions to the CUPS package.
17545 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
17546 Configuration of where to write logs, what directories to use for print
17547 spools, and related privileged configuration parameters.
17549 Available @code{files-configuration} fields are:
17551 @deftypevr {@code{files-configuration} parameter} log-location access-log
17552 Defines the access log filename. Specifying a blank filename disables
17553 access log generation. The value @code{stderr} causes log entries to be
17554 sent to the standard error file when the scheduler is running in the
17555 foreground, or to the system log daemon when run in the background. The
17556 value @code{syslog} causes log entries to be sent to the system log
17557 daemon. The server name may be included in filenames using the string
17558 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
17560 Defaults to @samp{"/var/log/cups/access_log"}.
17563 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
17564 Where CUPS should cache data.
17566 Defaults to @samp{"/var/cache/cups"}.
17569 @deftypevr {@code{files-configuration} parameter} string config-file-perm
17570 Specifies the permissions for all configuration files that the scheduler
17573 Note that the permissions for the printers.conf file are currently
17574 masked to only allow access from the scheduler user (typically root).
17575 This is done because printer device URIs sometimes contain sensitive
17576 authentication information that should not be generally known on the
17577 system. There is no way to disable this security feature.
17579 Defaults to @samp{"0640"}.
17582 @deftypevr {@code{files-configuration} parameter} log-location error-log
17583 Defines the error log filename. Specifying a blank filename disables
17584 error log generation. The value @code{stderr} causes log entries to be
17585 sent to the standard error file when the scheduler is running in the
17586 foreground, or to the system log daemon when run in the background. The
17587 value @code{syslog} causes log entries to be sent to the system log
17588 daemon. The server name may be included in filenames using the string
17589 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
17591 Defaults to @samp{"/var/log/cups/error_log"}.
17594 @deftypevr {@code{files-configuration} parameter} string fatal-errors
17595 Specifies which errors are fatal, causing the scheduler to exit. The
17600 No errors are fatal.
17603 All of the errors below are fatal.
17606 Browsing initialization errors are fatal, for example failed connections
17607 to the DNS-SD daemon.
17610 Configuration file syntax errors are fatal.
17613 Listen or Port errors are fatal, except for IPv6 failures on the
17614 loopback or @code{any} addresses.
17617 Log file creation or write errors are fatal.
17620 Bad startup file permissions are fatal, for example shared TLS
17621 certificate and key files with world-read permissions.
17624 Defaults to @samp{"all -browse"}.
17627 @deftypevr {@code{files-configuration} parameter} boolean file-device?
17628 Specifies whether the file pseudo-device can be used for new printer
17629 queues. The URI @uref{file:///dev/null} is always allowed.
17631 Defaults to @samp{#f}.
17634 @deftypevr {@code{files-configuration} parameter} string group
17635 Specifies the group name or ID that will be used when executing external
17638 Defaults to @samp{"lp"}.
17641 @deftypevr {@code{files-configuration} parameter} string log-file-perm
17642 Specifies the permissions for all log files that the scheduler writes.
17644 Defaults to @samp{"0644"}.
17647 @deftypevr {@code{files-configuration} parameter} log-location page-log
17648 Defines the page log filename. Specifying a blank filename disables
17649 page log generation. The value @code{stderr} causes log entries to be
17650 sent to the standard error file when the scheduler is running in the
17651 foreground, or to the system log daemon when run in the background. The
17652 value @code{syslog} causes log entries to be sent to the system log
17653 daemon. The server name may be included in filenames using the string
17654 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
17656 Defaults to @samp{"/var/log/cups/page_log"}.
17659 @deftypevr {@code{files-configuration} parameter} string remote-root
17660 Specifies the username that is associated with unauthenticated accesses
17661 by clients claiming to be the root user. The default is @code{remroot}.
17663 Defaults to @samp{"remroot"}.
17666 @deftypevr {@code{files-configuration} parameter} file-name request-root
17667 Specifies the directory that contains print jobs and other HTTP request
17670 Defaults to @samp{"/var/spool/cups"}.
17673 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
17674 Specifies the level of security sandboxing that is applied to print
17675 filters, backends, and other child processes of the scheduler; either
17676 @code{relaxed} or @code{strict}. This directive is currently only
17677 used/supported on macOS.
17679 Defaults to @samp{strict}.
17682 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
17683 Specifies the location of TLS certificates and private keys. CUPS will
17684 look for public and private keys in this directory: @file{.crt} files
17685 for PEM-encoded certificates and corresponding @file{.key} files for
17686 PEM-encoded private keys.
17688 Defaults to @samp{"/etc/cups/ssl"}.
17691 @deftypevr {@code{files-configuration} parameter} file-name server-root
17692 Specifies the directory containing the server configuration files.
17694 Defaults to @samp{"/etc/cups"}.
17697 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
17698 Specifies whether the scheduler calls fsync(2) after writing
17699 configuration or state files.
17701 Defaults to @samp{#f}.
17704 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
17705 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
17708 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
17709 Specifies the directory where temporary files are stored.
17711 Defaults to @samp{"/var/spool/cups/tmp"}.
17714 @deftypevr {@code{files-configuration} parameter} string user
17715 Specifies the user name or ID that is used when running external
17718 Defaults to @samp{"lp"}.
17721 @deftypevr {@code{files-configuration} parameter} string set-env
17722 Set the specified environment variable to be passed to child processes.
17724 Defaults to @samp{"variable value"}.
17728 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
17729 Specifies the logging level for the AccessLog file. The @code{config}
17730 level logs when printers and classes are added, deleted, or modified and
17731 when configuration files are accessed or updated. The @code{actions}
17732 level logs when print jobs are submitted, held, released, modified, or
17733 canceled, and any of the conditions for @code{config}. The @code{all}
17734 level logs all requests.
17736 Defaults to @samp{actions}.
17739 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
17740 Specifies whether to purge job history data automatically when it is no
17741 longer required for quotas.
17743 Defaults to @samp{#f}.
17746 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
17747 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
17748 For example, @samp{"_cups" "_print"} will tell network clients that both
17749 CUPS sharing and IPP Everywhere are supported.
17751 Defaults to @samp{"_cups"}.
17754 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
17755 Specifies which protocols to use for local printer sharing.
17757 Defaults to @samp{dnssd}.
17760 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
17761 Specifies whether the CUPS web interface is advertised.
17763 Defaults to @samp{#f}.
17766 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
17767 Specifies whether shared printers are advertised.
17769 Defaults to @samp{#f}.
17772 @deftypevr {@code{cups-configuration} parameter} string classification
17773 Specifies the security classification of the server. Any valid banner
17774 name can be used, including @samp{"classified"}, @samp{"confidential"},
17775 @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
17776 banner can be omitted to disable secure printing functions.
17778 Defaults to @samp{""}.
17781 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
17782 Specifies whether users may override the classification (cover page) of
17783 individual print jobs using the @code{job-sheets} option.
17785 Defaults to @samp{#f}.
17788 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
17789 Specifies the default type of authentication to use.
17791 Defaults to @samp{Basic}.
17794 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
17795 Specifies whether encryption will be used for authenticated requests.
17797 Defaults to @samp{Required}.
17800 @deftypevr {@code{cups-configuration} parameter} string default-language
17801 Specifies the default language to use for text and web content.
17803 Defaults to @samp{"en"}.
17806 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
17807 Specifies the default paper size for new print queues. @samp{"Auto"}
17808 uses a locale-specific default, while @samp{"None"} specifies there is
17809 no default paper size. Specific size names are typically
17810 @samp{"Letter"} or @samp{"A4"}.
17812 Defaults to @samp{"Auto"}.
17815 @deftypevr {@code{cups-configuration} parameter} string default-policy
17816 Specifies the default access policy to use.
17818 Defaults to @samp{"default"}.
17821 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
17822 Specifies whether local printers are shared by default.
17824 Defaults to @samp{#t}.
17827 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
17828 Specifies the delay for updating of configuration and state files, in
17829 seconds. A value of 0 causes the update to happen as soon as possible,
17830 typically within a few milliseconds.
17832 Defaults to @samp{30}.
17835 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
17836 Specifies what to do when an error occurs. Possible values are
17837 @code{abort-job}, which will discard the failed print job;
17838 @code{retry-job}, which will retry the job at a later time;
17839 @code{retry-current-job}, which retries the failed job immediately; and
17840 @code{stop-printer}, which stops the printer.
17842 Defaults to @samp{stop-printer}.
17845 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
17846 Specifies the maximum cost of filters that are run concurrently, which
17847 can be used to minimize disk, memory, and CPU resource problems. A
17848 limit of 0 disables filter limiting. An average print to a
17849 non-PostScript printer needs a filter limit of about 200. A PostScript
17850 printer needs about half that (100). Setting the limit below these
17851 thresholds will effectively limit the scheduler to printing a single job
17854 Defaults to @samp{0}.
17857 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
17858 Specifies the scheduling priority of filters that are run to print a
17859 job. The nice value ranges from 0, the highest priority, to 19, the
17862 Defaults to @samp{0}.
17865 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
17866 Specifies whether to do reverse lookups on connecting clients. The
17867 @code{double} setting causes @code{cupsd} to verify that the hostname
17868 resolved from the address matches one of the addresses returned for that
17869 hostname. Double lookups also prevent clients with unregistered
17870 addresses from connecting to your server. Only set this option to
17871 @code{#t} or @code{double} if absolutely required.
17873 Defaults to @samp{#f}.
17876 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
17877 Specifies the number of seconds to wait before killing the filters and
17878 backend associated with a canceled or held job.
17880 Defaults to @samp{30}.
17883 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
17884 Specifies the interval between retries of jobs in seconds. This is
17885 typically used for fax queues but can also be used with normal print
17886 queues whose error policy is @code{retry-job} or
17887 @code{retry-current-job}.
17889 Defaults to @samp{30}.
17892 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
17893 Specifies the number of retries that are done for jobs. This is
17894 typically used for fax queues but can also be used with normal print
17895 queues whose error policy is @code{retry-job} or
17896 @code{retry-current-job}.
17898 Defaults to @samp{5}.
17901 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
17902 Specifies whether to support HTTP keep-alive connections.
17904 Defaults to @samp{#t}.
17907 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
17908 Specifies how long an idle client connection remains open, in seconds.
17910 Defaults to @samp{30}.
17913 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
17914 Specifies the maximum size of print files, IPP requests, and HTML form
17915 data. A limit of 0 disables the limit check.
17917 Defaults to @samp{0}.
17920 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
17921 Listens on the specified interfaces for connections. Valid values are
17922 of the form @var{address}:@var{port}, where @var{address} is either an
17923 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
17924 indicate all addresses. Values can also be file names of local UNIX
17925 domain sockets. The Listen directive is similar to the Port directive
17926 but allows you to restrict access to specific interfaces or networks.
17929 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
17930 Specifies the number of pending connections that will be allowed. This
17931 normally only affects very busy servers that have reached the MaxClients
17932 limit, but can also be triggered by large numbers of simultaneous
17933 connections. When the limit is reached, the operating system will
17934 refuse additional connections until the scheduler can accept the pending
17937 Defaults to @samp{128}.
17940 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
17941 Specifies a set of additional access controls.
17943 Available @code{location-access-controls} fields are:
17945 @deftypevr {@code{location-access-controls} parameter} file-name path
17946 Specifies the URI path to which the access control applies.
17949 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
17950 Access controls for all access to this path, in the same format as the
17951 @code{access-controls} of @code{operation-access-control}.
17953 Defaults to @samp{()}.
17956 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
17957 Access controls for method-specific access to this path.
17959 Defaults to @samp{()}.
17961 Available @code{method-access-controls} fields are:
17963 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
17964 If @code{#t}, apply access controls to all methods except the listed
17965 methods. Otherwise apply to only the listed methods.
17967 Defaults to @samp{#f}.
17970 @deftypevr {@code{method-access-controls} parameter} method-list methods
17971 Methods to which this access control applies.
17973 Defaults to @samp{()}.
17976 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
17977 Access control directives, as a list of strings. Each string should be
17978 one directive, such as @samp{"Order allow,deny"}.
17980 Defaults to @samp{()}.
17985 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
17986 Specifies the number of debugging messages that are retained for logging
17987 if an error occurs in a print job. Debug messages are logged regardless
17988 of the LogLevel setting.
17990 Defaults to @samp{100}.
17993 @deftypevr {@code{cups-configuration} parameter} log-level log-level
17994 Specifies the level of logging for the ErrorLog file. The value
17995 @code{none} stops all logging while @code{debug2} logs everything.
17997 Defaults to @samp{info}.
18000 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
18001 Specifies the format of the date and time in the log files. The value
18002 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
18004 Defaults to @samp{standard}.
18007 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
18008 Specifies the maximum number of simultaneous clients that are allowed by
18011 Defaults to @samp{100}.
18014 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
18015 Specifies the maximum number of simultaneous clients that are allowed
18016 from a single address.
18018 Defaults to @samp{100}.
18021 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
18022 Specifies the maximum number of copies that a user can print of each
18025 Defaults to @samp{9999}.
18028 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
18029 Specifies the maximum time a job may remain in the @code{indefinite}
18030 hold state before it is canceled. A value of 0 disables cancellation of
18033 Defaults to @samp{0}.
18036 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
18037 Specifies the maximum number of simultaneous jobs that are allowed. Set
18038 to 0 to allow an unlimited number of jobs.
18040 Defaults to @samp{500}.
18043 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
18044 Specifies the maximum number of simultaneous jobs that are allowed per
18045 printer. A value of 0 allows up to MaxJobs jobs per printer.
18047 Defaults to @samp{0}.
18050 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
18051 Specifies the maximum number of simultaneous jobs that are allowed per
18052 user. A value of 0 allows up to MaxJobs jobs per user.
18054 Defaults to @samp{0}.
18057 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
18058 Specifies the maximum time a job may take to print before it is
18059 canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
18061 Defaults to @samp{10800}.
18064 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
18065 Specifies the maximum size of the log files before they are rotated, in
18066 bytes. The value 0 disables log rotation.
18068 Defaults to @samp{1048576}.
18071 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
18072 Specifies the maximum amount of time to allow between files in a
18073 multiple file print job, in seconds.
18075 Defaults to @samp{300}.
18078 @deftypevr {@code{cups-configuration} parameter} string page-log-format
18079 Specifies the format of PageLog lines. Sequences beginning with percent
18080 (@samp{%}) characters are replaced with the corresponding information,
18081 while all other characters are copied literally. The following percent
18082 sequences are recognized:
18086 insert a single percent character
18089 insert the value of the specified IPP attribute
18092 insert the number of copies for the current page
18095 insert the current page number
18098 insert the current date and time in common log format
18104 insert the printer name
18107 insert the username
18110 A value of the empty string disables page logging. The string @code{%p
18111 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
18112 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
18115 Defaults to @samp{""}.
18118 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
18119 Passes the specified environment variable(s) to child processes; a list
18122 Defaults to @samp{()}.
18125 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
18126 Specifies named access control policies.
18128 Available @code{policy-configuration} fields are:
18130 @deftypevr {@code{policy-configuration} parameter} string name
18131 Name of the policy.
18134 @deftypevr {@code{policy-configuration} parameter} string job-private-access
18135 Specifies an access list for a job's private values. @code{@@ACL} maps
18136 to the printer's requesting-user-name-allowed or
18137 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
18138 owner. @code{@@SYSTEM} maps to the groups listed for the
18139 @code{system-group} field of the @code{files-config} configuration,
18140 which is reified into the @code{cups-files.conf(5)} file. Other
18141 possible elements of the access list include specific user names, and
18142 @code{@@@var{group}} to indicate members of a specific group. The
18143 access list may also be simply @code{all} or @code{default}.
18145 Defaults to @samp{"@@OWNER @@SYSTEM"}.
18148 @deftypevr {@code{policy-configuration} parameter} string job-private-values
18149 Specifies the list of job values to make private, or @code{all},
18150 @code{default}, or @code{none}.
18152 Defaults to @samp{"job-name job-originating-host-name
18153 job-originating-user-name phone"}.
18156 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
18157 Specifies an access list for a subscription's private values.
18158 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
18159 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
18160 owner. @code{@@SYSTEM} maps to the groups listed for the
18161 @code{system-group} field of the @code{files-config} configuration,
18162 which is reified into the @code{cups-files.conf(5)} file. Other
18163 possible elements of the access list include specific user names, and
18164 @code{@@@var{group}} to indicate members of a specific group. The
18165 access list may also be simply @code{all} or @code{default}.
18167 Defaults to @samp{"@@OWNER @@SYSTEM"}.
18170 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
18171 Specifies the list of job values to make private, or @code{all},
18172 @code{default}, or @code{none}.
18174 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
18175 notify-subscriber-user-name notify-user-data"}.
18178 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
18179 Access control by IPP operation.
18181 Defaults to @samp{()}.
18185 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
18186 Specifies whether job files (documents) are preserved after a job is
18187 printed. If a numeric value is specified, job files are preserved for
18188 the indicated number of seconds after printing. Otherwise a boolean
18189 value applies indefinitely.
18191 Defaults to @samp{86400}.
18194 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
18195 Specifies whether the job history is preserved after a job is printed.
18196 If a numeric value is specified, the job history is preserved for the
18197 indicated number of seconds after printing. If @code{#t}, the job
18198 history is preserved until the MaxJobs limit is reached.
18200 Defaults to @samp{#t}.
18203 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
18204 Specifies the amount of time to wait for job completion before
18205 restarting the scheduler.
18207 Defaults to @samp{30}.
18210 @deftypevr {@code{cups-configuration} parameter} string rip-cache
18211 Specifies the maximum amount of memory to use when converting documents
18212 into bitmaps for a printer.
18214 Defaults to @samp{"128m"}.
18217 @deftypevr {@code{cups-configuration} parameter} string server-admin
18218 Specifies the email address of the server administrator.
18220 Defaults to @samp{"root@@localhost.localdomain"}.
18223 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
18224 The ServerAlias directive is used for HTTP Host header validation when
18225 clients connect to the scheduler from external interfaces. Using the
18226 special name @code{*} can expose your system to known browser-based DNS
18227 rebinding attacks, even when accessing sites through a firewall. If the
18228 auto-discovery of alternate names does not work, we recommend listing
18229 each alternate name with a ServerAlias directive instead of using
18232 Defaults to @samp{*}.
18235 @deftypevr {@code{cups-configuration} parameter} string server-name
18236 Specifies the fully-qualified host name of the server.
18238 Defaults to @samp{"localhost"}.
18241 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
18242 Specifies what information is included in the Server header of HTTP
18243 responses. @code{None} disables the Server header. @code{ProductOnly}
18244 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
18245 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
18246 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
18247 the output of the @code{uname} command. @code{Full} reports @code{CUPS
18248 2.0.0 (@var{uname}) IPP/2.0}.
18250 Defaults to @samp{Minimal}.
18253 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
18254 Listens on the specified interfaces for encrypted connections. Valid
18255 values are of the form @var{address}:@var{port}, where @var{address} is
18256 either an IPv6 address enclosed in brackets, an IPv4 address, or
18257 @code{*} to indicate all addresses.
18259 Defaults to @samp{()}.
18262 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
18263 Sets encryption options. By default, CUPS only supports encryption
18264 using TLS v1.0 or higher using known secure cipher suites. Security is
18265 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
18266 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
18267 suites, which are required for some older clients. The @code{AllowSSL3} option
18268 enables SSL v3.0, which is required for some older clients that do not support
18269 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
18270 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
18271 protocol version to TLS v1.1.
18273 Defaults to @samp{()}.
18276 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
18277 Specifies whether the scheduler requires clients to strictly adhere to
18278 the IPP specifications.
18280 Defaults to @samp{#f}.
18283 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
18284 Specifies the HTTP request timeout, in seconds.
18286 Defaults to @samp{300}.
18290 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
18291 Specifies whether the web interface is enabled.
18293 Defaults to @samp{#f}.
18296 At this point you're probably thinking ``oh dear, Guix manual, I like
18297 you but you can stop already with the configuration options''. Indeed.
18298 However, one more point: it could be that you have an existing
18299 @code{cupsd.conf} that you want to use. In that case, you can pass an
18300 @code{opaque-cups-configuration} as the configuration of a
18301 @code{cups-service-type}.
18303 Available @code{opaque-cups-configuration} fields are:
18305 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
18309 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
18310 The contents of the @code{cupsd.conf}, as a string.
18313 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
18314 The contents of the @code{cups-files.conf} file, as a string.
18317 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
18318 strings of the same name, you could instantiate a CUPS service like
18322 (service cups-service-type
18323 (opaque-cups-configuration
18324 (cupsd.conf cupsd.conf)
18325 (cups-files.conf cups-files.conf)))
18329 @node Desktop Services
18330 @subsection Desktop Services
18332 The @code{(gnu services desktop)} module provides services that are
18333 usually useful in the context of a ``desktop'' setup---that is, on a
18334 machine running a graphical display server, possibly with graphical user
18335 interfaces, etc. It also defines services that provide specific desktop
18336 environments like GNOME, Xfce or MATE.
18338 To simplify things, the module defines a variable containing the set of
18339 services that users typically expect on a machine with a graphical
18340 environment and networking:
18342 @defvr {Scheme Variable} %desktop-services
18343 This is a list of services that builds upon @code{%base-services} and
18344 adds or adjusts services for a typical ``desktop'' setup.
18346 In particular, it adds a graphical login manager (@pxref{X Window,
18347 @code{gdm-service-type}}), screen lockers, a network management tool
18348 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
18349 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
18350 energy and color management services, the @code{elogind} login and seat
18351 manager, the Polkit privilege service, the GeoClue location service, the
18352 AccountsService daemon that allows authorized users change system passwords,
18353 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
18354 name service switch service configured to be able to use @code{nss-mdns}
18355 (@pxref{Name Service Switch, mDNS}).
18358 The @code{%desktop-services} variable can be used as the @code{services}
18359 field of an @code{operating-system} declaration (@pxref{operating-system
18360 Reference, @code{services}}).
18362 Additionally, the @code{gnome-desktop-service-type},
18363 @code{xfce-desktop-service}, @code{mate-desktop-service-type},
18364 @code{lxqt-desktop-service-type} and @code{enlightenment-desktop-service-type}
18365 procedures can add GNOME, Xfce, MATE and/or Enlightenment to a system. To
18366 ``add GNOME'' means that system-level services like the backlight adjustment
18367 helpers and the power management utilities are added to the system, extending
18368 @code{polkit} and @code{dbus} appropriately, allowing GNOME to operate with
18369 elevated privileges on a limited number of special-purpose system interfaces.
18370 Additionally, adding a service made by @code{gnome-desktop-service-type} adds
18371 the GNOME metapackage to the system profile. Likewise, adding the Xfce
18372 service not only adds the @code{xfce} metapackage to the system profile, but
18373 it also gives the Thunar file manager the ability to open a ``root-mode'' file
18374 management window, if the user authenticates using the administrator's
18375 password via the standard polkit graphical interface. To ``add MATE'' means
18376 that @code{polkit} and @code{dbus} are extended appropriately, allowing MATE
18377 to operate with elevated privileges on a limited number of special-purpose
18378 system interfaces. Additionally, adding a service of type
18379 @code{mate-desktop-service-type} adds the MATE metapackage to the system
18380 profile. ``Adding Enlightenment'' means that @code{dbus} is extended
18381 appropriately, and several of Enlightenment's binaries are set as setuid,
18382 allowing Enlightenment's screen locker and other functionality to work as
18385 The desktop environments in Guix use the Xorg display server by
18386 default. If you'd like to use the newer display server protocol
18387 called Wayland, you need to use the @code{sddm-service} instead of
18388 GDM as the graphical login manager. You should then
18389 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
18390 also try starting GNOME on Wayland manually from a TTY with the
18391 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
18392 gnome-session``. Currently only GNOME has support for Wayland.
18394 @defvr {Scheme Variable} gnome-desktop-service-type
18395 This is the type of the service that adds the @uref{https://www.gnome.org,
18396 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
18397 object (see below).
18399 This service adds the @code{gnome} package to the system profile, and extends
18400 polkit with the actions from @code{gnome-settings-daemon}.
18403 @deftp {Data Type} gnome-desktop-configuration
18404 Configuration record for the GNOME desktop environment.
18407 @item @code{gnome} (default: @code{gnome})
18408 The GNOME package to use.
18412 @defvr {Scheme Variable} xfce-desktop-service-type
18413 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
18414 desktop environment. Its value is an @code{xfce-desktop-configuration} object
18417 This service adds the @code{xfce} package to the system profile, and
18418 extends polkit with the ability for @code{thunar} to manipulate the file
18419 system as root from within a user session, after the user has authenticated
18420 with the administrator's password.
18423 @deftp {Data Type} xfce-desktop-configuration
18424 Configuration record for the Xfce desktop environment.
18427 @item @code{xfce} (default: @code{xfce})
18428 The Xfce package to use.
18432 @deffn {Scheme Variable} mate-desktop-service-type
18433 This is the type of the service that runs the @uref{https://mate-desktop.org/,
18434 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
18435 object (see below).
18437 This service adds the @code{mate} package to the system
18438 profile, and extends polkit with the actions from
18439 @code{mate-settings-daemon}.
18442 @deftp {Data Type} mate-desktop-configuration
18443 Configuration record for the MATE desktop environment.
18446 @item @code{mate} (default: @code{mate})
18447 The MATE package to use.
18451 @deffn {Scheme Variable} lxqt-desktop-service-type
18452 This is the type of the service that runs the @uref{https://lxqt.github.io,
18453 LXQt desktop environment}. Its value is a @code{lxqt-desktop-configuration}
18454 object (see below).
18456 This service adds the @code{lxqt} package to the system
18460 @deftp {Data Type} lxqt-desktop-configuration
18461 Configuration record for the LXQt desktop environment.
18464 @item @code{lxqt} (default: @code{lxqt})
18465 The LXQT package to use.
18469 @deffn {Scheme Variable} enlightenment-desktop-service-type
18470 Return a service that adds the @code{enlightenment} package to the system
18471 profile, and extends dbus with actions from @code{efl}.
18474 @deftp {Data Type} enlightenment-desktop-service-configuration
18476 @item @code{enlightenment} (default: @code{enlightenment})
18477 The enlightenment package to use.
18481 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
18482 the default @code{%desktop-services} variable doesn't include any of
18483 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
18484 @code{%desktop-services} in the @code{services} field of your
18485 @code{operating-system}:
18488 (use-modules (gnu))
18489 (use-service-modules desktop)
18492 ;; cons* adds items to the list given as its last argument.
18493 (services (cons* (service gnome-desktop-service-type)
18494 (service xfce-desktop-service)
18495 %desktop-services))
18499 These desktop environments will then be available as options in the
18500 graphical login window.
18502 The actual service definitions included in @code{%desktop-services} and
18503 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
18504 are described below.
18506 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
18507 Return a service that runs the ``system bus'', using @var{dbus}, with
18508 support for @var{services}.
18510 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
18511 facility. Its system bus is used to allow system services to communicate
18512 and to be notified of system-wide events.
18514 @var{services} must be a list of packages that provide an
18515 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
18516 and policy files. For example, to allow avahi-daemon to use the system bus,
18517 @var{services} must be equal to @code{(list avahi)}.
18520 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
18521 Return a service that runs the @code{elogind} login and
18522 seat management daemon. @uref{https://github.com/elogind/elogind,
18523 Elogind} exposes a D-Bus interface that can be used to know which users
18524 are logged in, know what kind of sessions they have open, suspend the
18525 system, inhibit system suspend, reboot the system, and other tasks.
18527 Elogind handles most system-level power events for a computer, for
18528 example suspending the system when a lid is closed, or shutting it down
18529 when the power button is pressed.
18531 The @var{config} keyword argument specifies the configuration for
18532 elogind, and should be the result of an @code{(elogind-configuration
18533 (@var{parameter} @var{value})...)} invocation. Available parameters and
18534 their default values are:
18537 @item kill-user-processes?
18539 @item kill-only-users
18541 @item kill-exclude-users
18543 @item inhibit-delay-max-seconds
18545 @item handle-power-key
18547 @item handle-suspend-key
18549 @item handle-hibernate-key
18551 @item handle-lid-switch
18553 @item handle-lid-switch-docked
18555 @item handle-lid-switch-external-power
18557 @item power-key-ignore-inhibited?
18559 @item suspend-key-ignore-inhibited?
18561 @item hibernate-key-ignore-inhibited?
18563 @item lid-switch-ignore-inhibited?
18565 @item holdoff-timeout-seconds
18569 @item idle-action-seconds
18571 @item runtime-directory-size-percent
18573 @item runtime-directory-size
18577 @item suspend-state
18578 @code{("mem" "standby" "freeze")}
18581 @item hibernate-state
18583 @item hibernate-mode
18584 @code{("platform" "shutdown")}
18585 @item hybrid-sleep-state
18587 @item hybrid-sleep-mode
18588 @code{("suspend" "platform" "shutdown")}
18592 @deffn {Scheme Procedure} accountsservice-service @
18593 [#:accountsservice @var{accountsservice}]
18594 Return a service that runs AccountsService, a system service that can
18595 list available accounts, change their passwords, and so on.
18596 AccountsService integrates with PolicyKit to enable unprivileged users
18597 to acquire the capability to modify their system configuration.
18598 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
18599 accountsservice web site} for more information.
18601 The @var{accountsservice} keyword argument is the @code{accountsservice}
18602 package to expose as a service.
18605 @deffn {Scheme Procedure} polkit-service @
18606 [#:polkit @var{polkit}]
18607 Return a service that runs the
18608 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
18609 management service}, which allows system administrators to grant access to
18610 privileged operations in a structured way. By querying the Polkit service, a
18611 privileged system component can know when it should grant additional
18612 capabilities to ordinary users. For example, an ordinary user can be granted
18613 the capability to suspend the system if the user is logged in locally.
18616 @defvr {Scheme Variable} polkit-wheel-service
18617 Service that adds the @code{wheel} group as admins to the Polkit
18618 service. This makes it so that users in the @code{wheel} group are queried
18619 for their own passwords when performing administrative actions instead of
18620 @code{root}'s, similar to the behaviour used by @code{sudo}.
18623 @defvr {Scheme Variable} upower-service-type
18624 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
18625 system-wide monitor for power consumption and battery levels, with the given
18626 configuration settings.
18628 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
18629 notably used by GNOME.
18632 @deftp {Data Type} upower-configuration
18633 Data type representation the configuration for UPower.
18637 @item @code{upower} (default: @var{upower})
18638 Package to use for @code{upower}.
18640 @item @code{watts-up-pro?} (default: @code{#f})
18641 Enable the Watts Up Pro device.
18643 @item @code{poll-batteries?} (default: @code{#t})
18644 Enable polling the kernel for battery level changes.
18646 @item @code{ignore-lid?} (default: @code{#f})
18647 Ignore the lid state, this can be useful if it's incorrect on a device.
18649 @item @code{use-percentage-for-policy?} (default: @code{#f})
18650 Whether battery percentage based policy should be used. The default is to use
18651 the time left, change to @code{#t} to use the percentage.
18653 @item @code{percentage-low} (default: @code{10})
18654 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
18655 at which the battery is considered low.
18657 @item @code{percentage-critical} (default: @code{3})
18658 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
18659 at which the battery is considered critical.
18661 @item @code{percentage-action} (default: @code{2})
18662 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
18663 at which action will be taken.
18665 @item @code{time-low} (default: @code{1200})
18666 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
18667 seconds at which the battery is considered low.
18669 @item @code{time-critical} (default: @code{300})
18670 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
18671 seconds at which the battery is considered critical.
18673 @item @code{time-action} (default: @code{120})
18674 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
18675 seconds at which action will be taken.
18677 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
18678 The action taken when @code{percentage-action} or @code{time-action} is
18679 reached (depending on the configuration of @code{use-percentage-for-policy?}).
18681 Possible values are:
18691 @code{'hybrid-sleep}.
18697 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
18698 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
18699 UDisks}, a @dfn{disk management} daemon that provides user interfaces
18700 with notifications and ways to mount/unmount disks. Programs that talk
18701 to UDisks include the @command{udisksctl} command, part of UDisks, and
18702 GNOME Disks. Note that Udisks relies on the @command{mount} command, so
18703 it will only be able to use the file-system utilities installed in the
18704 system profile. For example if you want to be able to mount NTFS
18705 file-systems in read and write fashion, you'll need to have
18706 @code{ntfs-3g} installed system-wide.
18709 @deffn {Scheme Variable} colord-service-type
18710 This is the type of the service that runs @command{colord}, a system
18711 service with a D-Bus
18712 interface to manage the color profiles of input and output devices such as
18713 screens and scanners. It is notably used by the GNOME Color Manager graphical
18714 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
18715 site} for more information.
18718 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
18719 Return a configuration allowing an application to access GeoClue
18720 location data. @var{name} is the Desktop ID of the application, without
18721 the @code{.desktop} part. If @var{allowed?} is true, the application
18722 will have access to location information by default. The boolean
18723 @var{system?} value indicates whether an application is a system component
18724 or not. Finally @var{users} is a list of UIDs of all users for which
18725 this application is allowed location info access. An empty users list
18726 means that all users are allowed.
18729 @cindex scanner access
18730 @deffn {Scheme Procedure} sane-service-type
18731 This service provides access to scanners @i{via}
18732 @uref{http://www.sane-project.org, SANE} by installing the necessary udev
18736 @defvr {Scheme Variable} %standard-geoclue-applications
18737 The standard list of well-known GeoClue application configurations,
18738 granting authority to the GNOME date-and-time utility to ask for the
18739 current location in order to set the time zone, and allowing the
18740 IceCat and Epiphany web browsers to request location information.
18741 IceCat and Epiphany both query the user before allowing a web page to
18742 know the user's location.
18745 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
18746 [#:whitelist '()] @
18747 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
18748 [#:submit-data? #f]
18749 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
18750 [#:submission-nick "geoclue"] @
18751 [#:applications %standard-geoclue-applications]
18752 Return a service that runs the GeoClue location service. This service
18753 provides a D-Bus interface to allow applications to request access to a
18754 user's physical location, and optionally to add information to online
18755 location databases. See
18756 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
18757 web site} for more information.
18760 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
18761 [@w{#:auto-enable? #f}]
18762 Return a service that runs the @command{bluetoothd} daemon, which
18763 manages all the Bluetooth devices and provides a number of D-Bus
18764 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
18765 powered automatically at boot, which can be useful when using a
18766 bluetooth keyboard or mouse.
18768 Users need to be in the @code{lp} group to access the D-Bus service.
18771 @defvr {Scheme Variable} gnome-keyring-service-type
18772 This is the type of the service that adds the
18773 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
18774 value is a @code{gnome-keyring-configuration} object (see below).
18776 This service adds the @code{gnome-keyring} package to the system profile
18777 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
18778 a user's login keyring when they log in or setting its password with passwd.
18781 @deftp {Data Type} gnome-keyring-configuration
18782 Configuration record for the GNOME Keyring service.
18785 @item @code{keyring} (default: @code{gnome-keyring})
18786 The GNOME keyring package to use.
18788 @item @code{pam-services}
18789 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
18790 services to extend, where @var{service} is the name of an existing
18791 service to extend and @var{kind} is one of @code{login} or
18794 If @code{login} is given, it adds an optional
18795 @code{pam_gnome_keyring.so} to the auth block without arguments and to
18796 the session block with @code{auto_start}. If @code{passwd} is given, it
18797 adds an optional @code{pam_gnome_keyring.so} to the password block
18800 By default, this field contains ``gdm-password'' with the value @code{login}
18801 and ``passwd'' is with the value @code{passwd}.
18806 @node Sound Services
18807 @subsection Sound Services
18809 @cindex sound support
18811 @cindex PulseAudio, sound support
18813 The @code{(gnu services sound)} module provides a service to configure the
18814 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
18815 preferred ALSA output driver.
18817 @deffn {Scheme Variable} alsa-service-type
18818 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
18819 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
18820 configuration file. The value for this type is a @command{alsa-configuration}
18821 record as in this example:
18824 (service alsa-service-type)
18827 See below for details about @code{alsa-configuration}.
18830 @deftp {Data Type} alsa-configuration
18831 Data type representing the configuration for @code{alsa-service}.
18834 @item @code{alsa-plugins} (default: @var{alsa-plugins})
18835 @code{alsa-plugins} package to use.
18837 @item @code{pulseaudio?} (default: @var{#t})
18838 Whether ALSA applications should transparently be made to use the
18839 @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
18841 Using PulseAudio allows you to run several sound-producing applications
18842 at the same time and to individual control them @i{via}
18843 @command{pavucontrol}, among other things.
18845 @item @code{extra-options} (default: @var{""})
18846 String to append to the @file{/etc/asound.conf} file.
18851 Individual users who want to override the system configuration of ALSA can do
18852 it with the @file{~/.asoundrc} file:
18855 # In guix, we have to specify the absolute path for plugins.
18857 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
18860 # Routing ALSA to jack:
18861 # <http://jackaudio.org/faq/routing_alsa.html>.
18865 0 system:playback_1
18866 1 system:playback_2
18883 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
18886 @deffn {Scheme Variable} pulseaudio-service-type
18887 This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
18888 sound server. It exists to allow system overrides of the default settings
18889 via @code{pulseaudio-configuration}, see below.
18892 This service overrides per-user configuration files. If you want
18893 PulseAudio to honor configuration files in @file{~/.config/pulse} you
18894 have to unset the environment variables @env{PULSE_CONFIG} and
18895 @env{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
18899 This service on its own does not ensure, that the @code{pulseaudio} package
18900 exists on your machine. It merely adds configuration files for it, as
18901 detailed below. In the (admittedly unlikely) case, that you find yourself
18902 without a @code{pulseaudio} package, consider enabling it through the
18903 @code{alsa-service-type} above.
18907 @deftp {Data Type} pulseaudio-configuration
18908 Data type representing the configuration for @code{pulseaudio-service}.
18911 @item @code{client-conf} (default: @code{'()})
18912 List of settings to set in @file{client.conf}.
18913 Accepts a list of strings or a symbol-value pairs. A string will be
18914 inserted as-is with a newline added. A pair will be formatted as
18915 ``key = value'', again with a newline added.
18917 @item @code{daemon-conf} (default: @code{'((flat-volumes . no))})
18918 List of settings to set in @file{daemon.conf}, formatted just like
18921 @item @code{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
18922 Script file to use as @file{default.pa}.
18924 @item @code{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
18925 Script file to use as @file{system.pa}.
18929 @deffn {Scheme Variable} ladspa-service-type
18930 This service sets the @var{LADSPA_PATH} variable, so that programs, which
18931 respect it, e.g. PulseAudio, can load LADSPA plugins.
18933 The following example will setup the service to enable modules from the
18934 @code{swh-plugins} package:
18937 (service ladspa-service-type
18938 (ladspa-configuration (plugins (list swh-plugins))))
18941 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
18946 @node Database Services
18947 @subsection Database Services
18951 The @code{(gnu services databases)} module provides the following services.
18953 @subsubheading PostgreSQL
18955 The following example describes a PostgreSQL service with the default
18959 (service postgresql-service-type
18960 (postgresql-configuration
18961 (postgresql postgresql-10)))
18964 If the services fails to start, it may be due to an incompatible
18965 cluster already present in @var{data-directory}. Adjust it (or, if you
18966 don't need the cluster anymore, delete @var{data-directory}), then
18967 restart the service.
18969 Peer authentication is used by default and the @code{postgres} user
18970 account has no shell, which prevents the direct execution of @code{psql}
18971 commands as this user. To use @code{psql}, you can temporarily log in
18972 as @code{postgres} using a shell, create a PostgreSQL superuser with the
18973 same name as one of the system users and then create the associated
18977 sudo -u postgres -s /bin/sh
18978 createuser --interactive
18979 createdb $MY_USER_LOGIN # Replace appropriately.
18982 @deftp {Data Type} postgresql-configuration
18983 Data type representing the configuration for the
18984 @code{postgresql-service-type}.
18987 @item @code{postgresql}
18988 PostgreSQL package to use for the service.
18990 @item @code{port} (default: @code{5432})
18991 Port on which PostgreSQL should listen.
18993 @item @code{locale} (default: @code{"en_US.utf8"})
18994 Locale to use as the default when creating the database cluster.
18996 @item @code{config-file} (default: @code{(postgresql-config-file)})
18997 The configuration file to use when running PostgreSQL. The default
18998 behaviour uses the postgresql-config-file record with the default values
19001 @item @code{data-directory} (default: @code{"/var/lib/postgresql/data"})
19002 Directory in which to store the data.
19004 @item @code{extension-packages} (default: @code{'()})
19005 @cindex postgresql extension-packages
19006 Additional extensions are loaded from packages listed in
19007 @var{extension-packages}. Extensions are available at runtime. For instance,
19008 to create a geographic database using the @code{postgis} extension, a user can
19009 configure the postgresql-service as in this example:
19013 (use-package-modules databases geo)
19017 ;; postgresql is required to run `psql' but postgis is not required for
19018 ;; proper operation.
19019 (packages (cons* postgresql %base-packages))
19022 (service postgresql-service-type
19023 (postgresql-configuration
19024 (postgresql postgresql-10)
19025 (extension-packages (list postgis))))
19029 Then the extension becomes visible and you can initialise an empty geographic
19030 database in this way:
19034 > create database postgistest;
19035 > \connect postgistest;
19036 > create extension postgis;
19037 > create extension postgis_topology;
19040 There is no need to add this field for contrib extensions such as hstore or
19041 dblink as they are already loadable by postgresql. This field is only
19042 required to add extensions provided by other packages.
19047 @deftp {Data Type} postgresql-config-file
19048 Data type representing the PostgreSQL configuration file. As shown in
19049 the following example, this can be used to customize the configuration
19050 of PostgreSQL. Note that you can use any G-expression or filename in
19051 place of this record, if you already have a configuration file you'd
19052 like to use for example.
19055 (service postgresql-service-type
19056 (postgresql-configuration
19058 (postgresql-config-file
19059 (log-destination "stderr")
19061 (plain-file "pg_hba.conf"
19063 local all all trust
19064 host all all 127.0.0.1/32 md5
19065 host all all ::1/128 md5"))
19067 '(("session_preload_libraries" "'auto_explain'")
19068 ("random_page_cost" "2")
19069 ("auto_explain.log_min_duration" "'100ms'")
19070 ("work_mem" "'500MB'")
19071 ("logging_collector" "on")
19072 ("log_directory" "'/var/log/postgresql'")))))))
19076 @item @code{log-destination} (default: @code{"syslog"})
19077 The logging method to use for PostgreSQL. Multiple values are accepted,
19078 separated by commas.
19080 @item @code{hba-file} (default: @code{%default-postgres-hba})
19081 Filename or G-expression for the host-based authentication
19084 @item @code{ident-file} (default: @code{%default-postgres-ident})
19085 Filename or G-expression for the user name mapping configuration.
19087 @item @code{extra-config} (default: @code{'()})
19088 List of additional keys and values to include in the PostgreSQL config
19089 file. Each entry in the list should be a list where the first element
19090 is the key, and the remaining elements are the values.
19095 @subsubheading MariaDB/MySQL
19097 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
19098 Return a service that runs @command{mysqld}, the MySQL or MariaDB
19101 The optional @var{config} argument specifies the configuration for
19102 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
19105 @deftp {Data Type} mysql-configuration
19106 Data type representing the configuration of @var{mysql-service}.
19109 @item @code{mysql} (default: @var{mariadb})
19110 Package object of the MySQL database server, can be either @var{mariadb}
19113 For MySQL, a temporary root password will be displayed at activation time.
19114 For MariaDB, the root password is empty.
19116 @item @code{port} (default: @code{3306})
19117 TCP port on which the database server listens for incoming connections.
19121 @subsubheading Memcached
19123 @defvr {Scheme Variable} memcached-service-type
19124 This is the service type for the @uref{https://memcached.org/,
19125 Memcached} service, which provides a distributed in memory cache. The
19126 value for the service type is a @code{memcached-configuration} object.
19130 (service memcached-service-type)
19133 @deftp {Data Type} memcached-configuration
19134 Data type representing the configuration of memcached.
19137 @item @code{memcached} (default: @code{memcached})
19138 The Memcached package to use.
19140 @item @code{interfaces} (default: @code{'("0.0.0.0")})
19141 Network interfaces on which to listen.
19143 @item @code{tcp-port} (default: @code{11211})
19144 Port on which to accept connections on,
19146 @item @code{udp-port} (default: @code{11211})
19147 Port on which to accept UDP connections on, a value of 0 will disable
19148 listening on a UDP socket.
19150 @item @code{additional-options} (default: @code{'()})
19151 Additional command line options to pass to @code{memcached}.
19155 @subsubheading MongoDB
19157 @defvr {Scheme Variable} mongodb-service-type
19158 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
19159 The value for the service type is a @code{mongodb-configuration} object.
19163 (service mongodb-service-type)
19166 @deftp {Data Type} mongodb-configuration
19167 Data type representing the configuration of mongodb.
19170 @item @code{mongodb} (default: @code{mongodb})
19171 The MongoDB package to use.
19173 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
19174 The configuration file for MongoDB.
19176 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
19177 This value is used to create the directory, so that it exists and is
19178 owned by the mongodb user. It should match the data-directory which
19179 MongoDB is configured to use through the configuration file.
19183 @subsubheading Redis
19185 @defvr {Scheme Variable} redis-service-type
19186 This is the service type for the @uref{https://redis.io/, Redis}
19187 key/value store, whose value is a @code{redis-configuration} object.
19190 @deftp {Data Type} redis-configuration
19191 Data type representing the configuration of redis.
19194 @item @code{redis} (default: @code{redis})
19195 The Redis package to use.
19197 @item @code{bind} (default: @code{"127.0.0.1"})
19198 Network interface on which to listen.
19200 @item @code{port} (default: @code{6379})
19201 Port on which to accept connections on, a value of 0 will disable
19202 listening on a TCP socket.
19204 @item @code{working-directory} (default: @code{"/var/lib/redis"})
19205 Directory in which to store the database and related files.
19209 @node Mail Services
19210 @subsection Mail Services
19214 The @code{(gnu services mail)} module provides Guix service definitions
19215 for email services: IMAP, POP3, and LMTP servers, as well as mail
19216 transport agents (MTAs). Lots of acronyms! These services are detailed
19217 in the subsections below.
19219 @subsubheading Dovecot Service
19221 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
19222 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
19225 By default, Dovecot does not need much configuration; the default
19226 configuration object created by @code{(dovecot-configuration)} will
19227 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
19228 certificate will be generated for TLS-protected connections, though
19229 Dovecot will also listen on cleartext ports by default. There are a
19230 number of options, though, which mail administrators might need to change,
19231 and as is the case with other services, Guix allows the system
19232 administrator to specify these parameters via a uniform Scheme interface.
19234 For example, to specify that mail is located at @code{maildir~/.mail},
19235 one would instantiate the Dovecot service like this:
19238 (dovecot-service #:config
19239 (dovecot-configuration
19240 (mail-location "maildir:~/.mail")))
19243 The available configuration parameters follow. Each parameter
19244 definition is preceded by its type; for example, @samp{string-list foo}
19245 indicates that the @code{foo} parameter should be specified as a list of
19246 strings. There is also a way to specify the configuration as a string,
19247 if you have an old @code{dovecot.conf} file that you want to port over
19248 from some other system; see the end for more details.
19250 @c The following documentation was initially generated by
19251 @c (generate-documentation) in (gnu services mail). Manually maintained
19252 @c documentation is better, so we shouldn't hesitate to edit below as
19253 @c needed. However if the change you want to make to this documentation
19254 @c can be done in an automated way, it's probably easier to change
19255 @c (generate-documentation) than to make it below and have to deal with
19256 @c the churn as dovecot updates.
19258 Available @code{dovecot-configuration} fields are:
19260 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
19261 The dovecot package.
19264 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
19265 A list of IPs or hosts where to listen for connections. @samp{*}
19266 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
19267 interfaces. If you want to specify non-default ports or anything more
19268 complex, customize the address and port fields of the
19269 @samp{inet-listener} of the specific services you are interested in.
19272 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
19273 List of protocols we want to serve. Available protocols include
19274 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
19276 Available @code{protocol-configuration} fields are:
19278 @deftypevr {@code{protocol-configuration} parameter} string name
19279 The name of the protocol.
19282 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
19283 UNIX socket path to the master authentication server to find users.
19284 This is used by imap (for shared users) and lda.
19285 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
19288 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
19289 Space separated list of plugins to load.
19292 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
19293 Maximum number of IMAP connections allowed for a user from each IP
19294 address. NOTE: The username is compared case-sensitively.
19295 Defaults to @samp{10}.
19300 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
19301 List of services to enable. Available services include @samp{imap},
19302 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
19305 Available @code{service-configuration} fields are:
19307 @deftypevr {@code{service-configuration} parameter} string kind
19308 The service kind. Valid values include @code{director},
19309 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
19310 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
19311 @code{tcpwrap}, @code{quota-warning}, or anything else.
19314 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
19315 Listeners for the service. A listener is either a
19316 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
19317 an @code{inet-listener-configuration}.
19318 Defaults to @samp{()}.
19320 Available @code{unix-listener-configuration} fields are:
19322 @deftypevr {@code{unix-listener-configuration} parameter} string path
19323 Path to the file, relative to @code{base-dir} field. This is also used as
19327 @deftypevr {@code{unix-listener-configuration} parameter} string mode
19328 The access mode for the socket.
19329 Defaults to @samp{"0600"}.
19332 @deftypevr {@code{unix-listener-configuration} parameter} string user
19333 The user to own the socket.
19334 Defaults to @samp{""}.
19337 @deftypevr {@code{unix-listener-configuration} parameter} string group
19338 The group to own the socket.
19339 Defaults to @samp{""}.
19343 Available @code{fifo-listener-configuration} fields are:
19345 @deftypevr {@code{fifo-listener-configuration} parameter} string path
19346 Path to the file, relative to @code{base-dir} field. This is also used as
19350 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
19351 The access mode for the socket.
19352 Defaults to @samp{"0600"}.
19355 @deftypevr {@code{fifo-listener-configuration} parameter} string user
19356 The user to own the socket.
19357 Defaults to @samp{""}.
19360 @deftypevr {@code{fifo-listener-configuration} parameter} string group
19361 The group to own the socket.
19362 Defaults to @samp{""}.
19366 Available @code{inet-listener-configuration} fields are:
19368 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
19369 The protocol to listen for.
19372 @deftypevr {@code{inet-listener-configuration} parameter} string address
19373 The address on which to listen, or empty for all addresses.
19374 Defaults to @samp{""}.
19377 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
19378 The port on which to listen.
19381 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
19382 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
19384 Defaults to @samp{#t}.
19389 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
19390 Maximum number of simultaneous client connections per process. Once
19391 this number of connections is received, the next incoming connection
19392 will prompt Dovecot to spawn another process. If set to 0,
19393 @code{default-client-limit} is used instead.
19395 Defaults to @samp{0}.
19399 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
19400 Number of connections to handle before starting a new process.
19401 Typically the only useful values are 0 (unlimited) or 1. 1 is more
19402 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
19403 Defaults to @samp{1}.
19407 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
19408 Maximum number of processes that can exist for this service. If set to
19409 0, @code{default-process-limit} is used instead.
19411 Defaults to @samp{0}.
19415 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
19416 Number of processes to always keep waiting for more connections.
19417 Defaults to @samp{0}.
19420 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
19421 If you set @samp{service-count 0}, you probably need to grow
19423 Defaults to @samp{256000000}.
19428 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
19429 Dict configuration, as created by the @code{dict-configuration}
19432 Available @code{dict-configuration} fields are:
19434 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
19435 A list of key-value pairs that this dict should hold.
19436 Defaults to @samp{()}.
19441 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
19442 A list of passdb configurations, each one created by the
19443 @code{passdb-configuration} constructor.
19445 Available @code{passdb-configuration} fields are:
19447 @deftypevr {@code{passdb-configuration} parameter} string driver
19448 The driver that the passdb should use. Valid values include
19449 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
19451 Defaults to @samp{"pam"}.
19454 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
19455 Space separated list of arguments to the passdb driver.
19456 Defaults to @samp{""}.
19461 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
19462 List of userdb configurations, each one created by the
19463 @code{userdb-configuration} constructor.
19465 Available @code{userdb-configuration} fields are:
19467 @deftypevr {@code{userdb-configuration} parameter} string driver
19468 The driver that the userdb should use. Valid values include
19469 @samp{passwd} and @samp{static}.
19470 Defaults to @samp{"passwd"}.
19473 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
19474 Space separated list of arguments to the userdb driver.
19475 Defaults to @samp{""}.
19478 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
19479 Override fields from passwd.
19480 Defaults to @samp{()}.
19485 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
19486 Plug-in configuration, created by the @code{plugin-configuration}
19490 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
19491 List of namespaces. Each item in the list is created by the
19492 @code{namespace-configuration} constructor.
19494 Available @code{namespace-configuration} fields are:
19496 @deftypevr {@code{namespace-configuration} parameter} string name
19497 Name for this namespace.
19500 @deftypevr {@code{namespace-configuration} parameter} string type
19501 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
19502 Defaults to @samp{"private"}.
19505 @deftypevr {@code{namespace-configuration} parameter} string separator
19506 Hierarchy separator to use. You should use the same separator for
19507 all namespaces or some clients get confused. @samp{/} is usually a good
19508 one. The default however depends on the underlying mail storage
19510 Defaults to @samp{""}.
19513 @deftypevr {@code{namespace-configuration} parameter} string prefix
19514 Prefix required to access this namespace. This needs to be
19515 different for all namespaces. For example @samp{Public/}.
19516 Defaults to @samp{""}.
19519 @deftypevr {@code{namespace-configuration} parameter} string location
19520 Physical location of the mailbox. This is in the same format as
19521 mail_location, which is also the default for it.
19522 Defaults to @samp{""}.
19525 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
19526 There can be only one INBOX, and this setting defines which
19528 Defaults to @samp{#f}.
19531 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
19532 If namespace is hidden, it's not advertised to clients via NAMESPACE
19533 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
19534 useful when converting from another server with different namespaces
19535 which you want to deprecate but still keep working. For example you can
19536 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
19538 Defaults to @samp{#f}.
19541 @deftypevr {@code{namespace-configuration} parameter} boolean list?
19542 Show the mailboxes under this namespace with the LIST command. This
19543 makes the namespace visible for clients that do not support the NAMESPACE
19544 extension. The special @code{children} value lists child mailboxes, but
19545 hides the namespace prefix.
19546 Defaults to @samp{#t}.
19549 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
19550 Namespace handles its own subscriptions. If set to @code{#f}, the
19551 parent namespace handles them. The empty prefix should always have this
19553 Defaults to @samp{#t}.
19556 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
19557 List of predefined mailboxes in this namespace.
19558 Defaults to @samp{()}.
19560 Available @code{mailbox-configuration} fields are:
19562 @deftypevr {@code{mailbox-configuration} parameter} string name
19563 Name for this mailbox.
19566 @deftypevr {@code{mailbox-configuration} parameter} string auto
19567 @samp{create} will automatically create this mailbox.
19568 @samp{subscribe} will both create and subscribe to the mailbox.
19569 Defaults to @samp{"no"}.
19572 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
19573 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
19574 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
19575 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
19576 Defaults to @samp{()}.
19583 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
19584 Base directory where to store runtime data.
19585 Defaults to @samp{"/var/run/dovecot/"}.
19588 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
19589 Greeting message for clients.
19590 Defaults to @samp{"Dovecot ready."}.
19593 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
19594 List of trusted network ranges. Connections from these IPs are
19595 allowed to override their IP addresses and ports (for logging and for
19596 authentication checks). @samp{disable-plaintext-auth} is also ignored
19597 for these networks. Typically you would specify your IMAP proxy servers
19599 Defaults to @samp{()}.
19602 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
19603 List of login access check sockets (e.g.@: tcpwrap).
19604 Defaults to @samp{()}.
19607 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
19608 Show more verbose process titles (in ps). Currently shows user name
19609 and IP address. Useful for seeing who is actually using the IMAP
19610 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
19612 Defaults to @samp{#f}.
19615 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
19616 Should all processes be killed when Dovecot master process shuts down.
19617 Setting this to @code{#f} means that Dovecot can be upgraded without
19618 forcing existing client connections to close (although that could also
19619 be a problem if the upgrade is e.g.@: due to a security fix).
19620 Defaults to @samp{#t}.
19623 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
19624 If non-zero, run mail commands via this many connections to doveadm
19625 server, instead of running them directly in the same process.
19626 Defaults to @samp{0}.
19629 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
19630 UNIX socket or host:port used for connecting to doveadm server.
19631 Defaults to @samp{"doveadm-server"}.
19634 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
19635 List of environment variables that are preserved on Dovecot startup
19636 and passed down to all of its child processes. You can also give
19637 key=value pairs to always set specific settings.
19640 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
19641 Disable LOGIN command and all other plaintext authentications unless
19642 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
19643 matches the local IP (i.e.@: you're connecting from the same computer),
19644 the connection is considered secure and plaintext authentication is
19645 allowed. See also ssl=required setting.
19646 Defaults to @samp{#t}.
19649 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
19650 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
19651 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
19652 for caching to be used.
19653 Defaults to @samp{0}.
19656 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
19657 Time to live for cached data. After TTL expires the cached record
19658 is no longer used, *except* if the main database lookup returns internal
19659 failure. We also try to handle password changes automatically: If
19660 user's previous authentication was successful, but this one wasn't, the
19661 cache isn't used. For now this works only with plaintext
19663 Defaults to @samp{"1 hour"}.
19666 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
19667 TTL for negative hits (user not found, password mismatch).
19668 0 disables caching them completely.
19669 Defaults to @samp{"1 hour"}.
19672 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
19673 List of realms for SASL authentication mechanisms that need them.
19674 You can leave it empty if you don't want to support multiple realms.
19675 Many clients simply use the first one listed here, so keep the default
19677 Defaults to @samp{()}.
19680 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
19681 Default realm/domain to use if none was specified. This is used for
19682 both SASL realms and appending @@domain to username in plaintext
19684 Defaults to @samp{""}.
19687 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
19688 List of allowed characters in username. If the user-given username
19689 contains a character not listed in here, the login automatically fails.
19690 This is just an extra check to make sure user can't exploit any
19691 potential quote escaping vulnerabilities with SQL/LDAP databases. If
19692 you want to allow all characters, set this value to empty.
19693 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
19696 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
19697 Username character translations before it's looked up from
19698 databases. The value contains series of from -> to characters. For
19699 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
19700 translated to @samp{@@}.
19701 Defaults to @samp{""}.
19704 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
19705 Username formatting before it's looked up from databases. You can
19706 use the standard variables here, e.g.@: %Lu would lowercase the username,
19707 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
19708 change the @samp{@@} into @samp{-AT-}. This translation is done after
19709 @samp{auth-username-translation} changes.
19710 Defaults to @samp{"%Lu"}.
19713 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
19714 If you want to allow master users to log in by specifying the master
19715 username within the normal username string (i.e.@: not using SASL
19716 mechanism's support for it), you can specify the separator character
19717 here. The format is then <username><separator><master username>.
19718 UW-IMAP uses @samp{*} as the separator, so that could be a good
19720 Defaults to @samp{""}.
19723 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
19724 Username to use for users logging in with ANONYMOUS SASL
19726 Defaults to @samp{"anonymous"}.
19729 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
19730 Maximum number of dovecot-auth worker processes. They're used to
19731 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
19732 They're automatically created and destroyed as needed.
19733 Defaults to @samp{30}.
19736 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
19737 Host name to use in GSSAPI principal names. The default is to use
19738 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
19739 allow all keytab entries.
19740 Defaults to @samp{""}.
19743 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
19744 Kerberos keytab to use for the GSSAPI mechanism. Will use the
19745 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
19746 need to change the auth service to run as root to be able to read this
19748 Defaults to @samp{""}.
19751 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
19752 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
19753 and @samp{ntlm-auth} helper.
19754 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
19755 Defaults to @samp{#f}.
19758 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
19759 Path for Samba's @samp{ntlm-auth} helper binary.
19760 Defaults to @samp{"/usr/bin/ntlm_auth"}.
19763 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
19764 Time to delay before replying to failed authentications.
19765 Defaults to @samp{"2 secs"}.
19768 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
19769 Require a valid SSL client certificate or the authentication
19771 Defaults to @samp{#f}.
19774 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
19775 Take the username from client's SSL certificate, using
19776 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
19778 Defaults to @samp{#f}.
19781 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
19782 List of wanted authentication mechanisms. Supported mechanisms are:
19783 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
19784 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
19785 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
19786 @samp{disable-plaintext-auth} setting.
19789 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
19790 List of IPs or hostnames to all director servers, including ourself.
19791 Ports can be specified as ip:port. The default port is the same as what
19792 director service's @samp{inet-listener} is using.
19793 Defaults to @samp{()}.
19796 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
19797 List of IPs or hostnames to all backend mail servers. Ranges are
19798 allowed too, like 10.0.0.10-10.0.0.30.
19799 Defaults to @samp{()}.
19802 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
19803 How long to redirect users to a specific server after it no longer
19804 has any connections.
19805 Defaults to @samp{"15 min"}.
19808 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
19809 How the username is translated before being hashed. Useful values
19810 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
19811 are shared within domain.
19812 Defaults to @samp{"%Lu"}.
19815 @deftypevr {@code{dovecot-configuration} parameter} string log-path
19816 Log file to use for error messages. @samp{syslog} logs to syslog,
19817 @samp{/dev/stderr} logs to stderr.
19818 Defaults to @samp{"syslog"}.
19821 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
19822 Log file to use for informational messages. Defaults to
19824 Defaults to @samp{""}.
19827 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
19828 Log file to use for debug messages. Defaults to
19829 @samp{info-log-path}.
19830 Defaults to @samp{""}.
19833 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
19834 Syslog facility to use if you're logging to syslog. Usually if you
19835 don't want to use @samp{mail}, you'll use local0..local7. Also other
19836 standard facilities are supported.
19837 Defaults to @samp{"mail"}.
19840 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
19841 Log unsuccessful authentication attempts and the reasons why they
19843 Defaults to @samp{#f}.
19846 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
19847 In case of password mismatches, log the attempted password. Valid
19848 values are no, plain and sha1. sha1 can be useful for detecting brute
19849 force password attempts vs. user simply trying the same password over
19850 and over again. You can also truncate the value to n chars by appending
19851 ":n" (e.g.@: sha1:6).
19852 Defaults to @samp{"no"}.
19855 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
19856 Even more verbose logging for debugging purposes. Shows for example
19858 Defaults to @samp{#f}.
19861 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
19862 In case of password mismatches, log the passwords and used scheme so
19863 the problem can be debugged. Enabling this also enables
19865 Defaults to @samp{#f}.
19868 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
19869 Enable mail process debugging. This can help you figure out why
19870 Dovecot isn't finding your mails.
19871 Defaults to @samp{#f}.
19874 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
19875 Show protocol level SSL errors.
19876 Defaults to @samp{#f}.
19879 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
19880 Prefix for each line written to log file. % codes are in
19881 strftime(3) format.
19882 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
19885 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
19886 List of elements we want to log. The elements which have a
19887 non-empty variable value are joined together to form a comma-separated
19891 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
19892 Login log format. %s contains @samp{login-log-format-elements}
19893 string, %$ contains the data we want to log.
19894 Defaults to @samp{"%$: %s"}.
19897 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
19898 Log prefix for mail processes. See doc/wiki/Variables.txt for list
19899 of possible variables you can use.
19900 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
19903 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
19904 Format to use for logging mail deliveries. You can use variables:
19907 Delivery status message (e.g.@: @samp{saved to INBOX})
19919 Defaults to @samp{"msgid=%m: %$"}.
19922 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
19923 Location for users' mailboxes. The default is empty, which means
19924 that Dovecot tries to find the mailboxes automatically. This won't work
19925 if the user doesn't yet have any mail, so you should explicitly tell
19926 Dovecot the full location.
19928 If you're using mbox, giving a path to the INBOX
19929 file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
19930 where the other mailboxes are kept. This is called the @emph{root mail
19931 directory}, and it must be the first path given in the
19932 @samp{mail-location} setting.
19934 There are a few special variables you can use, e.g.:
19940 user part in user@@domain, same as %u if there's no domain
19942 domain part in user@@domain, empty if there's no domain
19947 See doc/wiki/Variables.txt for full list. Some examples:
19949 @item maildir:~/Maildir
19950 @item mbox:~/mail:INBOX=/var/mail/%u
19951 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
19953 Defaults to @samp{""}.
19956 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
19957 System user and group used to access mails. If you use multiple,
19958 userdb can override these by returning uid or gid fields. You can use
19959 either numbers or names. <doc/wiki/UserIds.txt>.
19960 Defaults to @samp{""}.
19963 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
19965 Defaults to @samp{""}.
19968 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
19969 Group to enable temporarily for privileged operations. Currently
19970 this is used only with INBOX when either its initial creation or
19971 dotlocking fails. Typically this is set to @samp{"mail"} to give access to
19973 Defaults to @samp{""}.
19976 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
19977 Grant access to these supplementary groups for mail processes.
19978 Typically these are used to set up access to shared mailboxes. Note
19979 that it may be dangerous to set these if users can create symlinks
19980 (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
19981 could allow a user to delete others' mailboxes, or @code{ln -s
19982 /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
19986 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
19987 Allow full file system access to clients. There's no access checks
19988 other than what the operating system does for the active UID/GID. It
19989 works with both maildir and mboxes, allowing you to prefix mailboxes
19990 names with e.g.@: @file{/path/} or @file{~user/}.
19991 Defaults to @samp{#f}.
19994 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
19995 Don't use @code{mmap()} at all. This is required if you store indexes to
19996 shared file systems (NFS or clustered file system).
19997 Defaults to @samp{#f}.
20000 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
20001 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
20002 supports @samp{O_EXCL} since version 3, so this should be safe to use
20003 nowadays by default.
20004 Defaults to @samp{#t}.
20007 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
20008 When to use fsync() or fdatasync() calls:
20011 Whenever necessary to avoid losing important data
20013 Useful with e.g.@: NFS when @code{write()}s are delayed
20015 Never use it (best performance, but crashes can lose data).
20017 Defaults to @samp{"optimized"}.
20020 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
20021 Mail storage exists in NFS. Set this to yes to make Dovecot flush
20022 NFS caches whenever needed. If you're using only a single mail server
20024 Defaults to @samp{#f}.
20027 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
20028 Mail index files also exist in NFS. Setting this to yes requires
20029 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
20030 Defaults to @samp{#f}.
20033 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
20034 Locking method for index files. Alternatives are fcntl, flock and
20035 dotlock. Dotlocking uses some tricks which may create more disk I/O
20036 than other locking methods. NFS users: flock doesn't work, remember to
20037 change @samp{mmap-disable}.
20038 Defaults to @samp{"fcntl"}.
20041 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
20042 Directory in which LDA/LMTP temporarily stores incoming mails >128
20044 Defaults to @samp{"/tmp"}.
20047 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
20048 Valid UID range for users. This is mostly to make sure that users can't
20049 log in as daemons or other system users. Note that denying root logins is
20050 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
20052 Defaults to @samp{500}.
20055 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
20057 Defaults to @samp{0}.
20060 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
20061 Valid GID range for users. Users having non-valid GID as primary group ID
20062 aren't allowed to log in. If user belongs to supplementary groups with
20063 non-valid GIDs, those groups are not set.
20064 Defaults to @samp{1}.
20067 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
20069 Defaults to @samp{0}.
20072 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
20073 Maximum allowed length for mail keyword name. It's only forced when
20074 trying to create new keywords.
20075 Defaults to @samp{50}.
20078 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
20079 List of directories under which chrooting is allowed for mail
20080 processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
20081 too). This setting doesn't affect @samp{login-chroot}
20082 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
20083 @samp{/./} in home dirs are ignored. WARNING: Never add directories here
20084 which local users can modify, that may lead to root exploit. Usually
20085 this should be done only if you don't allow shell access for users.
20086 <doc/wiki/Chrooting.txt>.
20087 Defaults to @samp{()}.
20090 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
20091 Default chroot directory for mail processes. This can be overridden
20092 for specific users in user database by giving @samp{/./} in user's home
20093 directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
20094 there is no real need to do chrooting, Dovecot doesn't allow users to
20095 access files outside their mail directory anyway. If your home
20096 directories are prefixed with the chroot directory, append @samp{/.} to
20097 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
20098 Defaults to @samp{""}.
20101 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
20102 UNIX socket path to master authentication server to find users.
20103 This is used by imap (for shared users) and lda.
20104 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
20107 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
20108 Directory where to look up mail plugins.
20109 Defaults to @samp{"/usr/lib/dovecot"}.
20112 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
20113 List of plugins to load for all services. Plugins specific to IMAP,
20114 LDA, etc.@: are added to this list in their own .conf files.
20115 Defaults to @samp{()}.
20118 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
20119 The minimum number of mails in a mailbox before updates are done to
20120 cache file. This allows optimizing Dovecot's behavior to do less disk
20121 writes at the cost of more disk reads.
20122 Defaults to @samp{0}.
20125 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
20126 When IDLE command is running, mailbox is checked once in a while to
20127 see if there are any new mails or other changes. This setting defines
20128 the minimum time to wait between those checks. Dovecot can also use
20129 dnotify, inotify and kqueue to find out immediately when changes
20131 Defaults to @samp{"30 secs"}.
20134 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
20135 Save mails with CR+LF instead of plain LF. This makes sending those
20136 mails take less CPU, especially with sendfile() syscall with Linux and
20137 FreeBSD. But it also creates a bit more disk I/O which may just make it
20138 slower. Also note that if other software reads the mboxes/maildirs,
20139 they may handle the extra CRs wrong and cause problems.
20140 Defaults to @samp{#f}.
20143 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
20144 By default LIST command returns all entries in maildir beginning
20145 with a dot. Enabling this option makes Dovecot return only entries
20146 which are directories. This is done by stat()ing each entry, so it
20147 causes more disk I/O.
20148 (For systems setting struct @samp{dirent->d_type} this check is free
20149 and it's done always regardless of this setting).
20150 Defaults to @samp{#f}.
20153 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
20154 When copying a message, do it with hard links whenever possible.
20155 This makes the performance much better, and it's unlikely to have any
20157 Defaults to @samp{#t}.
20160 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
20161 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
20162 directory only when its mtime changes unexpectedly or when we can't find
20163 the mail otherwise.
20164 Defaults to @samp{#f}.
20167 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
20168 Which locking methods to use for locking mbox. There are four
20173 Create <mailbox>.lock file. This is the oldest and most NFS-safe
20174 solution. If you want to use /var/mail/ like directory, the users will
20175 need write access to that directory.
20177 Same as dotlock, but if it fails because of permissions or because there
20178 isn't enough disk space, just skip it.
20180 Use this if possible. Works with NFS too if lockd is used.
20182 May not exist in all systems. Doesn't work with NFS.
20184 May not exist in all systems. Doesn't work with NFS.
20187 You can use multiple locking methods; if you do the order they're declared
20188 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
20189 locking methods as well. Some operating systems don't allow using some of
20190 them simultaneously.
20193 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
20197 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
20198 Maximum time to wait for lock (all of them) before aborting.
20199 Defaults to @samp{"5 mins"}.
20202 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
20203 If dotlock exists but the mailbox isn't modified in any way,
20204 override the lock file after this much time.
20205 Defaults to @samp{"2 mins"}.
20208 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
20209 When mbox changes unexpectedly we have to fully read it to find out
20210 what changed. If the mbox is large this can take a long time. Since
20211 the change is usually just a newly appended mail, it'd be faster to
20212 simply read the new mails. If this setting is enabled, Dovecot does
20213 this but still safely fallbacks to re-reading the whole mbox file
20214 whenever something in mbox isn't how it's expected to be. The only real
20215 downside to this setting is that if some other MUA changes message
20216 flags, Dovecot doesn't notice it immediately. Note that a full sync is
20217 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
20218 Defaults to @samp{#t}.
20221 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
20222 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
20223 EXAMINE, EXPUNGE or CHECK commands. If this is set,
20224 @samp{mbox-dirty-syncs} is ignored.
20225 Defaults to @samp{#f}.
20228 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
20229 Delay writing mbox headers until doing a full write sync (EXPUNGE
20230 and CHECK commands and when closing the mailbox). This is especially
20231 useful for POP3 where clients often delete all mails. The downside is
20232 that our changes aren't immediately visible to other MUAs.
20233 Defaults to @samp{#t}.
20236 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
20237 If mbox size is smaller than this (e.g.@: 100k), don't write index
20238 files. If an index file already exists it's still read, just not
20240 Defaults to @samp{0}.
20243 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
20244 Maximum dbox file size until it's rotated.
20245 Defaults to @samp{10000000}.
20248 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
20249 Maximum dbox file age until it's rotated. Typically in days. Day
20250 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
20252 Defaults to @samp{"1d"}.
20255 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
20256 When creating new mdbox files, immediately preallocate their size to
20257 @samp{mdbox-rotate-size}. This setting currently works only in Linux
20258 with some file systems (ext4, xfs).
20259 Defaults to @samp{#f}.
20262 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
20263 sdbox and mdbox support saving mail attachments to external files,
20264 which also allows single instance storage for them. Other backends
20265 don't support this for now.
20267 WARNING: This feature hasn't been tested much yet. Use at your own risk.
20269 Directory root where to store mail attachments. Disabled, if empty.
20270 Defaults to @samp{""}.
20273 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
20274 Attachments smaller than this aren't saved externally. It's also
20275 possible to write a plugin to disable saving specific attachments
20277 Defaults to @samp{128000}.
20280 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
20281 File system backend to use for saving attachments:
20284 No SiS done by Dovecot (but this might help FS's own deduplication)
20286 SiS with immediate byte-by-byte comparison during saving
20287 @item sis-queue posix
20288 SiS with delayed comparison and deduplication.
20290 Defaults to @samp{"sis posix"}.
20293 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
20294 Hash format to use in attachment filenames. You can add any text and
20295 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
20296 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
20297 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
20298 Defaults to @samp{"%@{sha1@}"}.
20301 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
20303 Defaults to @samp{100}.
20306 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
20308 Defaults to @samp{1000}.
20311 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
20312 Default VSZ (virtual memory size) limit for service processes.
20313 This is mainly intended to catch and kill processes that leak memory
20314 before they eat up everything.
20315 Defaults to @samp{256000000}.
20318 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
20319 Login user is internally used by login processes. This is the most
20320 untrusted user in Dovecot system. It shouldn't have access to anything
20322 Defaults to @samp{"dovenull"}.
20325 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
20326 Internal user is used by unprivileged processes. It should be
20327 separate from login user, so that login processes can't disturb other
20329 Defaults to @samp{"dovecot"}.
20332 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
20333 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
20334 Defaults to @samp{"required"}.
20337 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
20338 PEM encoded X.509 SSL/TLS certificate (public key).
20339 Defaults to @samp{"</etc/dovecot/default.pem"}.
20342 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
20343 PEM encoded SSL/TLS private key. The key is opened before
20344 dropping root privileges, so keep the key file unreadable by anyone but
20346 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
20349 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
20350 If key file is password protected, give the password here.
20351 Alternatively give it when starting dovecot with -p parameter. Since
20352 this file is often world-readable, you may want to place this setting
20353 instead to a different.
20354 Defaults to @samp{""}.
20357 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
20358 PEM encoded trusted certificate authority. Set this only if you
20359 intend to use @samp{ssl-verify-client-cert? #t}. The file should
20360 contain the CA certificate(s) followed by the matching
20361 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
20362 Defaults to @samp{""}.
20365 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
20366 Require that CRL check succeeds for client certificates.
20367 Defaults to @samp{#t}.
20370 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
20371 Request client to send a certificate. If you also want to require
20372 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
20373 Defaults to @samp{#f}.
20376 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
20377 Which field from certificate to use for username. commonName and
20378 x500UniqueIdentifier are the usual choices. You'll also need to set
20379 @samp{auth-ssl-username-from-cert? #t}.
20380 Defaults to @samp{"commonName"}.
20383 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
20384 Minimum SSL protocol version to accept.
20385 Defaults to @samp{"TLSv1"}.
20388 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
20389 SSL ciphers to use.
20390 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
20393 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
20394 SSL crypto device to use, for valid values run "openssl engine".
20395 Defaults to @samp{""}.
20398 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
20399 Address to use when sending rejection mails.
20400 %d expands to recipient domain.
20401 Defaults to @samp{"postmaster@@%d"}.
20404 @deftypevr {@code{dovecot-configuration} parameter} string hostname
20405 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
20406 and in LMTP replies. Default is the system's real hostname@@domain.
20407 Defaults to @samp{""}.
20410 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
20411 If user is over quota, return with temporary failure instead of
20413 Defaults to @samp{#f}.
20416 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
20417 Binary to use for sending mails.
20418 Defaults to @samp{"/usr/sbin/sendmail"}.
20421 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
20422 If non-empty, send mails via this SMTP host[:port] instead of
20424 Defaults to @samp{""}.
20427 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
20428 Subject: header to use for rejection mails. You can use the same
20429 variables as for @samp{rejection-reason} below.
20430 Defaults to @samp{"Rejected: %s"}.
20433 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
20434 Human readable error message for rejection mails. You can use
20447 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
20450 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
20451 Delimiter character between local-part and detail in email
20453 Defaults to @samp{"+"}.
20456 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
20457 Header where the original recipient address (SMTP's RCPT TO:
20458 address) is taken from if not available elsewhere. With dovecot-lda -a
20459 parameter overrides this. A commonly used header for this is
20461 Defaults to @samp{""}.
20464 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
20465 Should saving a mail to a nonexistent mailbox automatically create
20467 Defaults to @samp{#f}.
20470 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
20471 Should automatically created mailboxes be also automatically
20473 Defaults to @samp{#f}.
20476 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
20477 Maximum IMAP command line length. Some clients generate very long
20478 command lines with huge mailboxes, so you may need to raise this if you
20479 get "Too long argument" or "IMAP command line too large" errors
20481 Defaults to @samp{64000}.
20484 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
20485 IMAP logout format string:
20488 total number of bytes read from client
20490 total number of bytes sent to client.
20492 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
20493 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@}"}.
20496 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
20497 Override the IMAP CAPABILITY response. If the value begins with '+',
20498 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
20499 Defaults to @samp{""}.
20502 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
20503 How long to wait between "OK Still here" notifications when client
20505 Defaults to @samp{"2 mins"}.
20508 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
20509 ID field names and values to send to clients. Using * as the value
20510 makes Dovecot use the default value. The following fields have default
20511 values currently: name, version, os, os-version, support-url,
20513 Defaults to @samp{""}.
20516 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
20517 ID fields sent by client to log. * means everything.
20518 Defaults to @samp{""}.
20521 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
20522 Workarounds for various client bugs:
20525 @item delay-newmail
20526 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
20527 CHECK commands. Some clients ignore them otherwise, for example OSX
20528 Mail (<v2.1). Outlook Express breaks more badly though, without this it
20529 may show user "Message no longer in server" errors. Note that OE6
20530 still breaks even with this workaround if synchronization is set to
20533 @item tb-extra-mailbox-sep
20534 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
20535 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
20536 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
20538 @item tb-lsub-flags
20539 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
20540 This makes Thunderbird realize they aren't selectable and show them
20541 greyed out, instead of only later giving "not selectable" popup error.
20543 Defaults to @samp{()}.
20546 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
20547 Host allowed in URLAUTH URLs sent by client. "*" allows all.
20548 Defaults to @samp{""}.
20552 Whew! Lots of configuration options. The nice thing about it though is
20553 that Guix has a complete interface to Dovecot's configuration
20554 language. This allows not only a nice way to declare configurations,
20555 but also offers reflective capabilities as well: users can write code to
20556 inspect and transform configurations from within Scheme.
20558 However, it could be that you just want to get a @code{dovecot.conf} up
20559 and running. In that case, you can pass an
20560 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
20561 @code{dovecot-service}. As its name indicates, an opaque configuration
20562 does not have easy reflective capabilities.
20564 Available @code{opaque-dovecot-configuration} fields are:
20566 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
20567 The dovecot package.
20570 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
20571 The contents of the @code{dovecot.conf}, as a string.
20574 For example, if your @code{dovecot.conf} is just the empty string, you
20575 could instantiate a dovecot service like this:
20578 (dovecot-service #:config
20579 (opaque-dovecot-configuration
20583 @subsubheading OpenSMTPD Service
20585 @deffn {Scheme Variable} opensmtpd-service-type
20586 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
20587 service, whose value should be an @code{opensmtpd-configuration} object
20588 as in this example:
20591 (service opensmtpd-service-type
20592 (opensmtpd-configuration
20593 (config-file (local-file "./my-smtpd.conf"))))
20597 @deftp {Data Type} opensmtpd-configuration
20598 Data type representing the configuration of opensmtpd.
20601 @item @code{package} (default: @var{opensmtpd})
20602 Package object of the OpenSMTPD SMTP server.
20604 @item @code{config-file} (default: @code{%default-opensmtpd-file})
20605 File-like object of the OpenSMTPD configuration file to use. By default
20606 it listens on the loopback network interface, and allows for mail from
20607 users and daemons on the local machine, as well as permitting email to
20608 remote servers. Run @command{man smtpd.conf} for more information.
20613 @subsubheading Exim Service
20615 @cindex mail transfer agent (MTA)
20616 @cindex MTA (mail transfer agent)
20619 @deffn {Scheme Variable} exim-service-type
20620 This is the type of the @uref{https://exim.org, Exim} mail transfer
20621 agent (MTA), whose value should be an @code{exim-configuration} object
20622 as in this example:
20625 (service exim-service-type
20626 (exim-configuration
20627 (config-file (local-file "./my-exim.conf"))))
20631 In order to use an @code{exim-service-type} service you must also have a
20632 @code{mail-aliases-service-type} service present in your
20633 @code{operating-system} (even if it has no aliases).
20635 @deftp {Data Type} exim-configuration
20636 Data type representing the configuration of exim.
20639 @item @code{package} (default: @var{exim})
20640 Package object of the Exim server.
20642 @item @code{config-file} (default: @code{#f})
20643 File-like object of the Exim configuration file to use. If its value is
20644 @code{#f} then use the default configuration file from the package
20645 provided in @code{package}. The resulting configuration file is loaded
20646 after setting the @code{exim_user} and @code{exim_group} configuration
20652 @subsubheading Getmail service
20657 @deffn {Scheme Variable} getmail-service-type
20658 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
20659 mail retriever, whose value should be an @code{getmail-configuration}.
20662 Available @code{getmail-configuration} fields are:
20664 @deftypevr {@code{getmail-configuration} parameter} symbol name
20665 A symbol to identify the getmail service.
20667 Defaults to @samp{"unset"}.
20671 @deftypevr {@code{getmail-configuration} parameter} package package
20672 The getmail package to use.
20676 @deftypevr {@code{getmail-configuration} parameter} string user
20677 The user to run getmail as.
20679 Defaults to @samp{"getmail"}.
20683 @deftypevr {@code{getmail-configuration} parameter} string group
20684 The group to run getmail as.
20686 Defaults to @samp{"getmail"}.
20690 @deftypevr {@code{getmail-configuration} parameter} string directory
20691 The getmail directory to use.
20693 Defaults to @samp{"/var/lib/getmail/default"}.
20697 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
20698 The getmail configuration file to use.
20700 Available @code{getmail-configuration-file} fields are:
20702 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
20703 What mail account to retrieve mail from, and how to access that account.
20705 Available @code{getmail-retriever-configuration} fields are:
20707 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
20708 The type of mail retriever to use. Valid values include @samp{passwd}
20711 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
20715 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
20716 Username to login to the mail server with.
20718 Defaults to @samp{unset}.
20722 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
20723 Username to login to the mail server with.
20725 Defaults to @samp{unset}.
20729 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
20730 Port number to connect to.
20732 Defaults to @samp{#f}.
20736 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
20737 Override fields from passwd.
20739 Defaults to @samp{""}.
20743 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
20744 Override fields from passwd.
20746 Defaults to @samp{()}.
20750 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
20751 PEM-formatted key file to use for the TLS negotiation.
20753 Defaults to @samp{""}.
20757 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
20758 PEM-formatted certificate file to use for the TLS negotiation.
20760 Defaults to @samp{""}.
20764 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
20765 CA certificates to use.
20767 Defaults to @samp{""}.
20771 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
20772 Extra retriever parameters.
20774 Defaults to @samp{()}.
20780 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
20781 What to do with retrieved messages.
20783 Available @code{getmail-destination-configuration} fields are:
20785 @deftypevr {@code{getmail-destination-configuration} parameter} string type
20786 The type of mail destination. Valid values include @samp{Maildir},
20787 @samp{Mboxrd} and @samp{MDA_external}.
20789 Defaults to @samp{unset}.
20793 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
20794 The path option for the mail destination. The behaviour depends on the
20797 Defaults to @samp{""}.
20801 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
20802 Extra destination parameters
20804 Defaults to @samp{()}.
20810 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
20813 Available @code{getmail-options-configuration} fields are:
20815 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
20816 If set to @samp{0}, getmail will only print warnings and errors. A
20817 value of @samp{1} means that messages will be printed about retrieving
20818 and deleting messages. If set to @samp{2}, getmail will print messages
20819 about each of it's actions.
20821 Defaults to @samp{1}.
20825 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
20826 If true, getmail will retrieve all available messages. Otherwise it
20827 will only retrieve messages it hasn't seen previously.
20829 Defaults to @samp{#t}.
20833 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
20834 If set to true, messages will be deleted from the server after
20835 retrieving and successfully delivering them. Otherwise, messages will
20836 be left on the server.
20838 Defaults to @samp{#f}.
20842 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
20843 Getmail will delete messages this number of days after seeing them, if
20844 they have been delivered. This means messages will be left on the
20845 server this number of days after delivering them. A value of @samp{0}
20846 disabled this feature.
20848 Defaults to @samp{0}.
20852 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
20853 Delete messages larger than this of bytes after retrieving them, even if
20854 the delete and delete-after options are disabled. A value of @samp{0}
20855 disables this feature.
20857 Defaults to @samp{0}.
20861 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
20862 Retrieve messages totalling up to this number of bytes before closing
20863 the session with the server. A value of @samp{0} disables this feature.
20865 Defaults to @samp{0}.
20869 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
20870 Don't retrieve messages larger than this number of bytes. A value of
20871 @samp{0} disables this feature.
20873 Defaults to @samp{0}.
20877 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
20878 If true, getmail will add a Delivered-To header to messages.
20880 Defaults to @samp{#t}.
20884 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
20885 If set, getmail adds a Received header to the messages.
20887 Defaults to @samp{#t}.
20891 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
20892 Getmail will record a log of its actions to the named file. A value of
20893 @samp{""} disables this feature.
20895 Defaults to @samp{""}.
20899 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
20900 If true, getmail will record a log of its actions using the system
20903 Defaults to @samp{#f}.
20907 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
20908 If true, getmail will log information about messages not retrieved and
20909 the reason for not retrieving them, as well as starting and ending
20912 Defaults to @samp{#f}.
20916 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
20917 Extra options to include.
20919 Defaults to @samp{()}.
20927 @deftypevr {@code{getmail-configuration} parameter} list idle
20928 A list of mailboxes that getmail should wait on the server for new mail
20929 notifications. This depends on the server supporting the IDLE
20932 Defaults to @samp{()}.
20936 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
20937 Environment variables to set for getmail.
20939 Defaults to @samp{()}.
20943 @subsubheading Mail Aliases Service
20945 @cindex email aliases
20946 @cindex aliases, for email addresses
20948 @deffn {Scheme Variable} mail-aliases-service-type
20949 This is the type of the service which provides @code{/etc/aliases},
20950 specifying how to deliver mail to users on this system.
20953 (service mail-aliases-service-type
20954 '(("postmaster" "bob")
20955 ("bob" "bob@@example.com" "bob@@example2.com")))
20959 The configuration for a @code{mail-aliases-service-type} service is an
20960 association list denoting how to deliver mail that comes to this
20961 system. Each entry is of the form @code{(alias addresses ...)}, with
20962 @code{alias} specifying the local alias and @code{addresses} specifying
20963 where to deliver this user's mail.
20965 The aliases aren't required to exist as users on the local system. In
20966 the above example, there doesn't need to be a @code{postmaster} entry in
20967 the @code{operating-system}'s @code{user-accounts} in order to deliver
20968 the @code{postmaster} mail to @code{bob} (which subsequently would
20969 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
20971 @subsubheading GNU Mailutils IMAP4 Daemon
20972 @cindex GNU Mailutils IMAP4 Daemon
20974 @deffn {Scheme Variable} imap4d-service-type
20975 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
20976 mailutils, GNU Mailutils Manual}), whose value should be an
20977 @code{imap4d-configuration} object as in this example:
20980 (service imap4d-service-type
20981 (imap4d-configuration
20982 (config-file (local-file "imap4d.conf"))))
20986 @deftp {Data Type} imap4d-configuration
20987 Data type representing the configuration of @command{imap4d}.
20990 @item @code{package} (default: @code{mailutils})
20991 The package that provides @command{imap4d}.
20993 @item @code{config-file} (default: @code{%default-imap4d-config-file})
20994 File-like object of the configuration file to use, by default it will listen
20995 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
20996 Mailutils Manual}, for details.
21001 @node Messaging Services
21002 @subsection Messaging Services
21007 The @code{(gnu services messaging)} module provides Guix service
21008 definitions for messaging services. Currently it provides the following
21011 @subsubheading Prosody Service
21013 @deffn {Scheme Variable} prosody-service-type
21014 This is the type for the @uref{https://prosody.im, Prosody XMPP
21015 communication server}. Its value must be a @code{prosody-configuration}
21016 record as in this example:
21019 (service prosody-service-type
21020 (prosody-configuration
21021 (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
21024 (int-component-configuration
21025 (hostname "conference.example.net")
21027 (mod-muc (mod-muc-configuration)))))
21030 (virtualhost-configuration
21031 (domain "example.net"))))))
21034 See below for details about @code{prosody-configuration}.
21038 By default, Prosody does not need much configuration. Only one
21039 @code{virtualhosts} field is needed: it specifies the domain you wish
21042 You can perform various sanity checks on the generated configuration
21043 with the @code{prosodyctl check} command.
21045 Prosodyctl will also help you to import certificates from the
21046 @code{letsencrypt} directory so that the @code{prosody} user can access
21047 them. See @url{https://prosody.im/doc/letsencrypt}.
21050 prosodyctl --root cert import /etc/letsencrypt/live
21053 The available configuration parameters follow. Each parameter
21054 definition is preceded by its type; for example, @samp{string-list foo}
21055 indicates that the @code{foo} parameter should be specified as a list of
21056 strings. Types starting with @code{maybe-} denote parameters that won't
21057 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
21059 There is also a way to specify the configuration as a string, if you
21060 have an old @code{prosody.cfg.lua} file that you want to port over from
21061 some other system; see the end for more details.
21063 The @code{file-object} type designates either a file-like object
21064 (@pxref{G-Expressions, file-like objects}) or a file name.
21066 @c The following documentation was initially generated by
21067 @c (generate-documentation) in (gnu services messaging). Manually maintained
21068 @c documentation is better, so we shouldn't hesitate to edit below as
21069 @c needed. However if the change you want to make to this documentation
21070 @c can be done in an automated way, it's probably easier to change
21071 @c (generate-documentation) than to make it below and have to deal with
21072 @c the churn as Prosody updates.
21074 Available @code{prosody-configuration} fields are:
21076 @deftypevr {@code{prosody-configuration} parameter} package prosody
21077 The Prosody package.
21080 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
21081 Location of the Prosody data storage directory. See
21082 @url{https://prosody.im/doc/configure}.
21083 Defaults to @samp{"/var/lib/prosody"}.
21086 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
21087 Additional plugin directories. They are searched in all the specified
21088 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
21089 Defaults to @samp{()}.
21092 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
21093 Every virtual host and component needs a certificate so that clients and
21094 servers can securely verify its identity. Prosody will automatically load
21095 certificates/keys from the directory specified here.
21096 Defaults to @samp{"/etc/prosody/certs"}.
21099 @deftypevr {@code{prosody-configuration} parameter} string-list admins
21100 This is a list of accounts that are admins for the server. Note that you
21101 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
21102 @url{https://prosody.im/doc/creating_accounts}.
21103 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
21104 Defaults to @samp{()}.
21107 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
21108 Enable use of libevent for better performance under high load. See
21109 @url{https://prosody.im/doc/libevent}.
21110 Defaults to @samp{#f}.
21113 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
21114 This is the list of modules Prosody will load on startup. It looks for
21115 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
21116 Documentation on modules can be found at:
21117 @url{https://prosody.im/doc/modules}.
21118 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
21121 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
21122 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
21123 should you want to disable them then add them to this list.
21124 Defaults to @samp{()}.
21127 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
21128 Path to a text file where the shared groups are defined. If this path is
21129 empty then @samp{mod_groups} does nothing. See
21130 @url{https://prosody.im/doc/modules/mod_groups}.
21131 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
21134 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
21135 Disable account creation by default, for security. See
21136 @url{https://prosody.im/doc/creating_accounts}.
21137 Defaults to @samp{#f}.
21140 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
21141 These are the SSL/TLS-related settings. Most of them are disabled so to
21142 use Prosody's defaults. If you do not completely understand these options, do
21143 not add them to your config, it is easy to lower the security of your server
21144 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
21146 Available @code{ssl-configuration} fields are:
21148 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
21149 This determines what handshake to use.
21152 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
21153 Path to your private key file.
21156 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
21157 Path to your certificate file.
21160 @deftypevr {@code{ssl-configuration} parameter} file-object capath
21161 Path to directory containing root certificates that you wish Prosody to
21162 trust when verifying the certificates of remote servers.
21163 Defaults to @samp{"/etc/ssl/certs"}.
21166 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
21167 Path to a file containing root certificates that you wish Prosody to trust.
21168 Similar to @code{capath} but with all certificates concatenated together.
21171 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
21172 A list of verification options (these mostly map to OpenSSL's
21173 @code{set_verify()} flags).
21176 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
21177 A list of general options relating to SSL/TLS. These map to OpenSSL's
21178 @code{set_options()}. For a full list of options available in LuaSec, see the
21182 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
21183 How long a chain of certificate authorities to check when looking for a
21184 trusted root certificate.
21187 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
21188 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
21189 clients, and in what order.
21192 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
21193 A path to a file containing parameters for Diffie-Hellman key exchange. You
21194 can create such a file with:
21195 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
21198 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
21199 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
21200 @samp{"secp384r1"}.
21203 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
21204 A list of ``extra'' verification options.
21207 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
21208 Password for encrypted private keys.
21213 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
21214 Whether to force all client-to-server connections to be encrypted or not.
21215 See @url{https://prosody.im/doc/modules/mod_tls}.
21216 Defaults to @samp{#f}.
21219 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
21220 Set of mechanisms that will never be offered. See
21221 @url{https://prosody.im/doc/modules/mod_saslauth}.
21222 Defaults to @samp{("DIGEST-MD5")}.
21225 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
21226 Whether to force all server-to-server connections to be encrypted or not.
21227 See @url{https://prosody.im/doc/modules/mod_tls}.
21228 Defaults to @samp{#f}.
21231 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
21232 Whether to require encryption and certificate authentication. This
21233 provides ideal security, but requires servers you communicate with to support
21234 encryption AND present valid, trusted certificates. See
21235 @url{https://prosody.im/doc/s2s#security}.
21236 Defaults to @samp{#f}.
21239 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
21240 Many servers don't support encryption or have invalid or self-signed
21241 certificates. You can list domains here that will not be required to
21242 authenticate using certificates. They will be authenticated using DNS. See
21243 @url{https://prosody.im/doc/s2s#security}.
21244 Defaults to @samp{()}.
21247 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
21248 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
21249 valid certificates for some domains by specifying a list here. See
21250 @url{https://prosody.im/doc/s2s#security}.
21251 Defaults to @samp{()}.
21254 @deftypevr {@code{prosody-configuration} parameter} string authentication
21255 Select the authentication backend to use. The default provider stores
21256 passwords in plaintext and uses Prosody's configured data storage to store the
21257 authentication data. If you do not trust your server please see
21258 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
21259 about using the hashed backend. See also
21260 @url{https://prosody.im/doc/authentication}
21261 Defaults to @samp{"internal_plain"}.
21264 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
21265 Set logging options. Advanced logging configuration is not yet supported
21266 by the Prosody service. See @url{https://prosody.im/doc/logging}.
21267 Defaults to @samp{"*syslog"}.
21270 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
21271 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
21272 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
21275 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
21276 Maximum allowed size of the HTTP body (in bytes).
21279 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
21280 Some modules expose their own URL in various ways. This URL is built
21281 from the protocol, host and port used. If Prosody sits behind a proxy, the
21282 public URL will be @code{http-external-url} instead. See
21283 @url{https://prosody.im/doc/http#external_url}.
21286 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
21287 A host in Prosody is a domain on which user accounts can be created. For
21288 example if you want your users to have addresses like
21289 @samp{"john.smith@@example.com"} then you need to add a host
21290 @samp{"example.com"}. All options in this list will apply only to this host.
21292 Note: the name @emph{virtual} host is used in configuration to avoid confusion with
21293 the actual physical host that Prosody is installed on. A single Prosody
21294 instance can serve many domains, each one defined as a VirtualHost entry in
21295 Prosody's configuration. Conversely a server that hosts a single domain would
21296 have just one VirtualHost entry.
21298 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
21300 Available @code{virtualhost-configuration} fields are:
21302 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:
21303 @deftypevr {@code{virtualhost-configuration} parameter} string domain
21304 Domain you wish Prosody to serve.
21309 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
21310 Components are extra services on a server which are available to clients,
21311 usually on a subdomain of the main server (such as
21312 @samp{"mycomponent.example.com"}). Example components might be chatroom
21313 servers, user directories, or gateways to other protocols.
21315 Internal components are implemented with Prosody-specific plugins. To add an
21316 internal component, you simply fill the hostname field, and the plugin you wish
21317 to use for the component.
21319 See @url{https://prosody.im/doc/components}.
21320 Defaults to @samp{()}.
21322 Available @code{int-component-configuration} fields are:
21324 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:
21325 @deftypevr {@code{int-component-configuration} parameter} string hostname
21326 Hostname of the component.
21329 @deftypevr {@code{int-component-configuration} parameter} string plugin
21330 Plugin you wish to use for the component.
21333 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
21334 Multi-user chat (MUC) is Prosody's module for allowing you to create
21335 hosted chatrooms/conferences for XMPP users.
21337 General information on setting up and using multi-user chatrooms can be found
21338 in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
21339 which you should read if you are new to XMPP chatrooms.
21341 See also @url{https://prosody.im/doc/modules/mod_muc}.
21343 Available @code{mod-muc-configuration} fields are:
21345 @deftypevr {@code{mod-muc-configuration} parameter} string name
21346 The name to return in service discovery responses.
21347 Defaults to @samp{"Prosody Chatrooms"}.
21350 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
21351 If @samp{#t}, this will only allow admins to create new chatrooms.
21352 Otherwise anyone can create a room. The value @samp{"local"} restricts room
21353 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
21354 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
21355 restricts to service administrators only.
21356 Defaults to @samp{#f}.
21359 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
21360 Maximum number of history messages that will be sent to the member that has
21361 just joined the room.
21362 Defaults to @samp{20}.
21369 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
21370 External components use XEP-0114, which most standalone components
21371 support. To add an external component, you simply fill the hostname field. See
21372 @url{https://prosody.im/doc/components}.
21373 Defaults to @samp{()}.
21375 Available @code{ext-component-configuration} fields are:
21377 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:
21378 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
21379 Password which the component will use to log in.
21382 @deftypevr {@code{ext-component-configuration} parameter} string hostname
21383 Hostname of the component.
21388 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
21389 Port(s) Prosody listens on for component connections.
21390 Defaults to @samp{(5347)}.
21393 @deftypevr {@code{prosody-configuration} parameter} string component-interface
21394 Interface Prosody listens on for component connections.
21395 Defaults to @samp{"127.0.0.1"}.
21398 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
21399 Raw content that will be added to the configuration file.
21402 It could be that you just want to get a @code{prosody.cfg.lua}
21403 up and running. In that case, you can pass an
21404 @code{opaque-prosody-configuration} record as the value of
21405 @code{prosody-service-type}. As its name indicates, an opaque configuration
21406 does not have easy reflective capabilities.
21407 Available @code{opaque-prosody-configuration} fields are:
21409 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
21410 The prosody package.
21413 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
21414 The contents of the @code{prosody.cfg.lua} to use.
21417 For example, if your @code{prosody.cfg.lua} is just the empty
21418 string, you could instantiate a prosody service like this:
21421 (service prosody-service-type
21422 (opaque-prosody-configuration
21423 (prosody.cfg.lua "")))
21426 @c end of Prosody auto-generated documentation
21428 @subsubheading BitlBee Service
21430 @cindex IRC (Internet Relay Chat)
21431 @cindex IRC gateway
21432 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
21433 interface to a variety of messaging protocols such as XMPP.
21435 @defvr {Scheme Variable} bitlbee-service-type
21436 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
21437 gateway daemon. Its value is a @code{bitlbee-configuration} (see
21440 To have BitlBee listen on port 6667 on localhost, add this line to your
21444 (service bitlbee-service-type)
21448 @deftp {Data Type} bitlbee-configuration
21449 This is the configuration for BitlBee, with the following fields:
21452 @item @code{interface} (default: @code{"127.0.0.1"})
21453 @itemx @code{port} (default: @code{6667})
21454 Listen on the network interface corresponding to the IP address
21455 specified in @var{interface}, on @var{port}.
21457 When @var{interface} is @code{127.0.0.1}, only local clients can
21458 connect; when it is @code{0.0.0.0}, connections can come from any
21459 networking interface.
21461 @item @code{bitlbee} (default: @code{bitlbee})
21462 The BitlBee package to use.
21464 @item @code{plugins} (default: @code{'()})
21465 List of plugin packages to use---e.g., @code{bitlbee-discord}.
21467 @item @code{extra-settings} (default: @code{""})
21468 Configuration snippet added as-is to the BitlBee configuration file.
21472 @subsubheading Quassel Service
21474 @cindex IRC (Internet Relay Chat)
21475 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
21476 meaning that one or more clients can attach to and detach from the
21479 @defvr {Scheme Variable} quassel-service-type
21480 This is the service type for the @url{https://quassel-irc.org/,Quassel}
21481 IRC backend daemon. Its value is a @code{quassel-configuration}
21485 @deftp {Data Type} quassel-configuration
21486 This is the configuration for Quassel, with the following fields:
21489 @item @code{quassel} (default: @code{quassel})
21490 The Quassel package to use.
21492 @item @code{interface} (default: @code{"::,0.0.0.0"})
21493 @item @code{port} (default: @code{4242})
21494 Listen on the network interface(s) corresponding to the IPv4 or IPv6
21495 interfaces specified in the comma delimited @var{interface}, on
21498 @item @code{loglevel} (default: @code{"Info"})
21499 The level of logging desired. Accepted values are Debug, Info, Warning
21504 @node Telephony Services
21505 @subsection Telephony Services
21507 @cindex Murmur (VoIP server)
21508 @cindex VoIP server
21509 This section describes how to set up and run a Murmur server. Murmur is
21510 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
21513 @deftp {Data Type} murmur-configuration
21514 The service type for the Murmur server. An example configuration can
21518 (service murmur-service-type
21519 (murmur-configuration
21521 "Welcome to this Mumble server running on Guix!")
21522 (cert-required? #t) ;disallow text password logins
21523 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
21524 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
21527 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
21528 password with the command that is printed during the activation phase.
21530 It is recommended to register a normal Mumble user account
21531 and grant it admin or moderator rights.
21532 You can use the @code{mumble} client to
21533 login as new normal user, register yourself, and log out.
21534 For the next step login with the name @code{SuperUser} use
21535 the @code{SuperUser} password that you set previously,
21536 and grant your newly registered mumble user administrator or moderator
21537 rights and create some channels.
21539 Available @code{murmur-configuration} fields are:
21542 @item @code{package} (default: @code{mumble})
21543 Package that contains @code{bin/murmurd}.
21545 @item @code{user} (default: @code{"murmur"})
21546 User who will run the Murmur server.
21548 @item @code{group} (default: @code{"murmur"})
21549 Group of the user who will run the murmur server.
21551 @item @code{port} (default: @code{64738})
21552 Port on which the server will listen.
21554 @item @code{welcome-text} (default: @code{""})
21555 Welcome text sent to clients when they connect.
21557 @item @code{server-password} (default: @code{""})
21558 Password the clients have to enter in order to connect.
21560 @item @code{max-users} (default: @code{100})
21561 Maximum of users that can be connected to the server at once.
21563 @item @code{max-user-bandwidth} (default: @code{#f})
21564 Maximum voice traffic a user can send per second.
21566 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
21567 File name of the sqlite database.
21568 The service's user will become the owner of the directory.
21570 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
21571 File name of the log file.
21572 The service's user will become the owner of the directory.
21574 @item @code{autoban-attempts} (default: @code{10})
21575 Maximum number of logins a user can make in @code{autoban-timeframe}
21576 without getting auto banned for @code{autoban-time}.
21578 @item @code{autoban-timeframe} (default: @code{120})
21579 Timeframe for autoban in seconds.
21581 @item @code{autoban-time} (default: @code{300})
21582 Amount of time in seconds for which a client gets banned
21583 when violating the autoban limits.
21585 @item @code{opus-threshold} (default: @code{100})
21586 Percentage of clients that need to support opus
21587 before switching over to opus audio codec.
21589 @item @code{channel-nesting-limit} (default: @code{10})
21590 How deep channels can be nested at maximum.
21592 @item @code{channelname-regex} (default: @code{#f})
21593 A string in form of a Qt regular expression that channel names must conform to.
21595 @item @code{username-regex} (default: @code{#f})
21596 A string in form of a Qt regular expression that user names must conform to.
21598 @item @code{text-message-length} (default: @code{5000})
21599 Maximum size in bytes that a user can send in one text chat message.
21601 @item @code{image-message-length} (default: @code{(* 128 1024)})
21602 Maximum size in bytes that a user can send in one image message.
21604 @item @code{cert-required?} (default: @code{#f})
21605 If it is set to @code{#t} clients that use weak password authentication
21606 will not be accepted. Users must have completed the certificate wizard to join.
21608 @item @code{remember-channel?} (default: @code{#f})
21609 Should murmur remember the last channel each user was in when they disconnected
21610 and put them into the remembered channel when they rejoin.
21612 @item @code{allow-html?} (default: @code{#f})
21613 Should html be allowed in text messages, user comments, and channel descriptions.
21615 @item @code{allow-ping?} (default: @code{#f})
21616 Setting to true exposes the current user count, the maximum user count, and
21617 the server's maximum bandwidth per client to unauthenticated users. In the
21618 Mumble client, this information is shown in the Connect dialog.
21620 Disabling this setting will prevent public listing of the server.
21622 @item @code{bonjour?} (default: @code{#f})
21623 Should the server advertise itself in the local network through the bonjour protocol.
21625 @item @code{send-version?} (default: @code{#f})
21626 Should the murmur server version be exposed in ping requests.
21628 @item @code{log-days} (default: @code{31})
21629 Murmur also stores logs in the database, which are accessible via RPC.
21630 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
21631 or -1 to disable logging to the database.
21633 @item @code{obfuscate-ips?} (default: @code{#t})
21634 Should logged ips be obfuscated to protect the privacy of users.
21636 @item @code{ssl-cert} (default: @code{#f})
21637 File name of the SSL/TLS certificate used for encrypted connections.
21640 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
21642 @item @code{ssl-key} (default: @code{#f})
21643 Filepath to the ssl private key used for encrypted connections.
21645 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
21648 @item @code{ssl-dh-params} (default: @code{#f})
21649 File name of a PEM-encoded file with Diffie-Hellman parameters
21650 for the SSL/TLS encryption. Alternatively you set it to
21651 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
21652 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
21654 @item @code{ssl-ciphers} (default: @code{#f})
21655 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
21658 This option is specified using
21659 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
21660 OpenSSL cipher list notation}.
21662 It is recommended that you try your cipher string using 'openssl ciphers <string>'
21663 before setting it here, to get a feel for which cipher suites you will get.
21664 After setting this option, it is recommend that you inspect your Murmur log
21665 to ensure that Murmur is using the cipher suites that you expected it to.
21667 Note: Changing this option may impact the backwards compatibility of your
21668 Murmur server, and can remove the ability for older Mumble clients to be able
21671 @item @code{public-registration} (default: @code{#f})
21672 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
21674 You can optionally register your server in the public server list that the
21675 @code{mumble} client shows on startup.
21676 You cannot register your server if you have set a @code{server-password},
21677 or set @code{allow-ping} to @code{#f}.
21679 It might take a few hours until it shows up in the public list.
21681 @item @code{file} (default: @code{#f})
21682 Optional alternative override for this configuration.
21686 @deftp {Data Type} murmur-public-registration-configuration
21687 Configuration for public registration of a murmur service.
21691 This is a display name for your server. Not to be confused with the hostname.
21693 @item @code{password}
21694 A password to identify your registration.
21695 Subsequent updates will need the same password. Don't lose your password.
21698 This should be a @code{http://} or @code{https://} link to your web
21701 @item @code{hostname} (default: @code{#f})
21702 By default your server will be listed by its IP address.
21703 If it is set your server will be linked by this host name instead.
21709 @node Monitoring Services
21710 @subsection Monitoring Services
21712 @subsubheading Tailon Service
21714 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
21715 viewing and searching log files.
21717 The following example will configure the service with default values.
21718 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
21721 (service tailon-service-type)
21724 The following example customises more of the Tailon configuration,
21725 adding @command{sed} to the list of allowed commands.
21728 (service tailon-service-type
21729 (tailon-configuration
21731 (tailon-configuration-file
21732 (allowed-commands '("tail" "grep" "awk" "sed"))))))
21736 @deftp {Data Type} tailon-configuration
21737 Data type representing the configuration of Tailon.
21738 This type has the following parameters:
21741 @item @code{config-file} (default: @code{(tailon-configuration-file)})
21742 The configuration file to use for Tailon. This can be set to a
21743 @dfn{tailon-configuration-file} record value, or any gexp
21744 (@pxref{G-Expressions}).
21746 For example, to instead use a local file, the @code{local-file} function
21750 (service tailon-service-type
21751 (tailon-configuration
21752 (config-file (local-file "./my-tailon.conf"))))
21755 @item @code{package} (default: @code{tailon})
21756 The tailon package to use.
21761 @deftp {Data Type} tailon-configuration-file
21762 Data type representing the configuration options for Tailon.
21763 This type has the following parameters:
21766 @item @code{files} (default: @code{(list "/var/log")})
21767 List of files to display. The list can include strings for a single file
21768 or directory, or a list, where the first item is the name of a
21769 subsection, and the remaining items are the files or directories in that
21772 @item @code{bind} (default: @code{"localhost:8080"})
21773 Address and port to which Tailon should bind on.
21775 @item @code{relative-root} (default: @code{#f})
21776 URL path to use for Tailon, set to @code{#f} to not use a path.
21778 @item @code{allow-transfers?} (default: @code{#t})
21779 Allow downloading the log files in the web interface.
21781 @item @code{follow-names?} (default: @code{#t})
21782 Allow tailing of not-yet existent files.
21784 @item @code{tail-lines} (default: @code{200})
21785 Number of lines to read initially from each file.
21787 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
21788 Commands to allow running. By default, @code{sed} is disabled.
21790 @item @code{debug?} (default: @code{#f})
21791 Set @code{debug?} to @code{#t} to show debug messages.
21793 @item @code{wrap-lines} (default: @code{#t})
21794 Initial line wrapping state in the web interface. Set to @code{#t} to
21795 initially wrap lines (the default), or to @code{#f} to initially not
21798 @item @code{http-auth} (default: @code{#f})
21799 HTTP authentication type to use. Set to @code{#f} to disable
21800 authentication (the default). Supported values are @code{"digest"} or
21803 @item @code{users} (default: @code{#f})
21804 If HTTP authentication is enabled (see @code{http-auth}), access will be
21805 restricted to the credentials provided here. To configure users, use a
21806 list of pairs, where the first element of the pair is the username, and
21807 the 2nd element of the pair is the password.
21810 (tailon-configuration-file
21811 (http-auth "basic")
21812 (users '(("user1" . "password1")
21813 ("user2" . "password2"))))
21820 @subsubheading Darkstat Service
21822 Darkstat is a packet sniffer that captures network traffic, calculates
21823 statistics about usage, and serves reports over HTTP.
21825 @defvar {Scheme Variable} darkstat-service-type
21826 This is the service type for the
21827 @uref{https://unix4lyfe.org/darkstat/, darkstat}
21828 service, its value must be a @code{darkstat-configuration} record as in
21832 (service darkstat-service-type
21833 (darkstat-configuration
21834 (interface "eno1")))
21838 @deftp {Data Type} darkstat-configuration
21839 Data type representing the configuration of @command{darkstat}.
21842 @item @code{package} (default: @code{darkstat})
21843 The darkstat package to use.
21845 @item @code{interface}
21846 Capture traffic on the specified network interface.
21848 @item @code{port} (default: @code{"667"})
21849 Bind the web interface to the specified port.
21851 @item @code{bind-address} (default: @code{"127.0.0.1"})
21852 Bind the web interface to the specified address.
21854 @item @code{base} (default: @code{"/"})
21855 Specify the path of the base URL. This can be useful if
21856 @command{darkstat} is accessed via a reverse proxy.
21861 @subsubheading Prometheus Node Exporter Service
21863 @cindex prometheus-node-exporter
21864 The Prometheus ``node exporter'' makes hardware and operating system statistics
21865 provided by the Linux kernel available for the Prometheus monitoring system.
21866 This service should be deployed on all physical nodes and virtual machines,
21867 where monitoring these statistics is desirable.
21869 @defvar {Scheme variable} prometheus-node-exporter-service-type
21870 This is the service type for the
21871 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
21872 service, its value must be a @code{prometheus-node-exporter-configuration}
21873 record as in this example:
21876 (service prometheus-node-exporter-service-type
21877 (prometheus-node-exporter-configuration
21878 (web-listen-address ":9100")))
21882 @deftp {Data Type} prometheus-node-exporter-configuration
21883 Data type representing the configuration of @command{node_exporter}.
21886 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
21887 The prometheus-node-exporter package to use.
21889 @item @code{web-listen-address} (default: @code{":9100"})
21890 Bind the web interface to the specified address.
21895 @subsubheading Zabbix server
21896 @cindex zabbix zabbix-server
21897 Zabbix provides monitoring metrics, among others network utilization, CPU load
21898 and disk space consumption:
21901 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
21902 @item Auto-discovery of servers and network devices and interfaces.
21903 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
21904 @item Distributed monitoring with centralized web administration.
21905 @item Native high performance agents.
21906 @item SLA, and ITIL KPI metrics on reporting.
21907 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
21908 @item Remote command execution through Zabbix proxies.
21911 @c %start of fragment
21913 Available @code{zabbix-server-configuration} fields are:
21915 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
21916 The zabbix-server package.
21920 @deftypevr {@code{zabbix-server-configuration} parameter} string user
21921 User who will run the Zabbix server.
21923 Defaults to @samp{"zabbix"}.
21927 @deftypevr {@code{zabbix-server-configuration} parameter} group group
21928 Group who will run the Zabbix server.
21930 Defaults to @samp{"zabbix"}.
21934 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
21935 Database host name.
21937 Defaults to @samp{"127.0.0.1"}.
21941 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
21944 Defaults to @samp{"zabbix"}.
21948 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
21951 Defaults to @samp{"zabbix"}.
21955 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
21956 Database password. Please, use @code{include-files} with
21957 @code{DBPassword=SECRET} inside a specified file instead.
21959 Defaults to @samp{""}.
21963 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
21966 Defaults to @samp{5432}.
21970 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
21971 Specifies where log messages are written to:
21975 @code{system} - syslog.
21978 @code{file} - file specified with @code{log-file} parameter.
21981 @code{console} - standard output.
21985 Defaults to @samp{""}.
21989 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
21990 Log file name for @code{log-type} @code{file} parameter.
21992 Defaults to @samp{"/var/log/zabbix/server.log"}.
21996 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
21999 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
22003 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
22004 The location of certificate authority (CA) files for SSL server
22005 certificate verification.
22007 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
22011 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
22012 Location of SSL client certificates.
22014 Defaults to @samp{"/etc/ssl/certs"}.
22018 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
22019 Extra options will be appended to Zabbix server configuration file.
22021 Defaults to @samp{""}.
22025 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
22026 You may include individual files or all files in a directory in the
22027 configuration file.
22029 Defaults to @samp{()}.
22033 @c %end of fragment
22035 @subsubheading Zabbix agent
22036 @cindex zabbix zabbix-agent
22038 Zabbix agent gathers information for Zabbix server.
22040 @c %start of fragment
22042 Available @code{zabbix-agent-configuration} fields are:
22044 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
22045 The zabbix-agent package.
22049 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
22050 User who will run the Zabbix agent.
22052 Defaults to @samp{"zabbix"}.
22056 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
22057 Group who will run the Zabbix agent.
22059 Defaults to @samp{"zabbix"}.
22063 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
22064 Unique, case sensitive hostname which is required for active checks and
22065 must match hostname as configured on the server.
22067 Defaults to @samp{"Zabbix server"}.
22071 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
22072 Specifies where log messages are written to:
22076 @code{system} - syslog.
22079 @code{file} - file specified with @code{log-file} parameter.
22082 @code{console} - standard output.
22086 Defaults to @samp{""}.
22090 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
22091 Log file name for @code{log-type} @code{file} parameter.
22093 Defaults to @samp{"/var/log/zabbix/agent.log"}.
22097 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
22100 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
22104 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
22105 List of IP addresses, optionally in CIDR notation, or hostnames of
22106 Zabbix servers and Zabbix proxies. Incoming connections will be
22107 accepted only from the hosts listed here.
22109 Defaults to @samp{("127.0.0.1")}.
22113 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
22114 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
22115 proxies for active checks. If port is not specified, default port is
22116 used. If this parameter is not specified, active checks are disabled.
22118 Defaults to @samp{("127.0.0.1")}.
22122 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
22123 Extra options will be appended to Zabbix server configuration file.
22125 Defaults to @samp{""}.
22129 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
22130 You may include individual files or all files in a directory in the
22131 configuration file.
22133 Defaults to @samp{()}.
22137 @c %end of fragment
22139 @subsubheading Zabbix front-end
22140 @cindex zabbix zabbix-front-end
22142 This service provides a WEB interface to Zabbix server.
22144 @c %start of fragment
22146 Available @code{zabbix-front-end-configuration} fields are:
22148 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
22149 NGINX configuration.
22153 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
22154 Database host name.
22156 Defaults to @samp{"localhost"}.
22160 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
22163 Defaults to @samp{5432}.
22167 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
22170 Defaults to @samp{"zabbix"}.
22174 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
22177 Defaults to @samp{"zabbix"}.
22181 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
22182 Database password. Please, use @code{db-secret-file} instead.
22184 Defaults to @samp{""}.
22188 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
22189 Secret file containing the credentials for the Zabbix front-end. The value
22190 must be a local file name, not a G-expression. You are expected to create
22191 this file manually. Its contents will be copied into @file{zabbix.conf.php}
22192 as the value of @code{$DB['PASSWORD']}.
22194 Defaults to @samp{""}.
22198 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
22199 Zabbix server hostname.
22201 Defaults to @samp{"localhost"}.
22205 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
22206 Zabbix server port.
22208 Defaults to @samp{10051}.
22213 @c %end of fragment
22215 @node Kerberos Services
22216 @subsection Kerberos Services
22219 The @code{(gnu services kerberos)} module provides services relating to
22220 the authentication protocol @dfn{Kerberos}.
22222 @subsubheading Krb5 Service
22224 Programs using a Kerberos client library normally
22225 expect a configuration file in @file{/etc/krb5.conf}.
22226 This service generates such a file from a definition provided in the
22227 operating system declaration.
22228 It does not cause any daemon to be started.
22230 No ``keytab'' files are provided by this service---you must explicitly create them.
22231 This service is known to work with the MIT client library, @code{mit-krb5}.
22232 Other implementations have not been tested.
22234 @defvr {Scheme Variable} krb5-service-type
22235 A service type for Kerberos 5 clients.
22239 Here is an example of its use:
22241 (service krb5-service-type
22242 (krb5-configuration
22243 (default-realm "EXAMPLE.COM")
22244 (allow-weak-crypto? #t)
22247 (name "EXAMPLE.COM")
22248 (admin-server "groucho.example.com")
22249 (kdc "karl.example.com"))
22252 (admin-server "kerb-admin.argrx.edu")
22253 (kdc "keys.argrx.edu"))))))
22257 This example provides a Kerberos@tie{}5 client configuration which:
22259 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
22260 of which have distinct administration servers and key distribution centers;
22261 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
22262 specified by clients;
22263 @item Accepts services which only support encryption types known to be weak.
22266 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
22267 Only the most commonly used ones are described here.
22268 For a full list, and more detailed explanation of each, see the MIT
22269 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
22273 @deftp {Data Type} krb5-realm
22274 @cindex realm, kerberos
22277 This field is a string identifying the name of the realm.
22278 A common convention is to use the fully qualified DNS name of your organization,
22279 converted to upper case.
22281 @item @code{admin-server}
22282 This field is a string identifying the host where the administration server is
22286 This field is a string identifying the key distribution center
22291 @deftp {Data Type} krb5-configuration
22294 @item @code{allow-weak-crypto?} (default: @code{#f})
22295 If this flag is @code{#t} then services which only offer encryption algorithms
22296 known to be weak will be accepted.
22298 @item @code{default-realm} (default: @code{#f})
22299 This field should be a string identifying the default Kerberos
22300 realm for the client.
22301 You should set this field to the name of your Kerberos realm.
22302 If this value is @code{#f}
22303 then a realm must be specified with every Kerberos principal when invoking programs
22304 such as @command{kinit}.
22306 @item @code{realms}
22307 This should be a non-empty list of @code{krb5-realm} objects, which clients may
22309 Normally, one of them will have a @code{name} field matching the @code{default-realm}
22315 @subsubheading PAM krb5 Service
22318 The @code{pam-krb5} service allows for login authentication and password
22319 management via Kerberos.
22320 You will need this service if you want PAM enabled applications to authenticate
22321 users using Kerberos.
22323 @defvr {Scheme Variable} pam-krb5-service-type
22324 A service type for the Kerberos 5 PAM module.
22327 @deftp {Data Type} pam-krb5-configuration
22328 Data type representing the configuration of the Kerberos 5 PAM module.
22329 This type has the following parameters:
22331 @item @code{pam-krb5} (default: @code{pam-krb5})
22332 The pam-krb5 package to use.
22334 @item @code{minimum-uid} (default: @code{1000})
22335 The smallest user ID for which Kerberos authentications should be attempted.
22336 Local accounts with lower values will silently fail to authenticate.
22341 @node LDAP Services
22342 @subsection LDAP Services
22344 @cindex nslcd, LDAP service
22346 The @code{(gnu services authentication)} module provides the
22347 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
22348 server. In addition to configuring the service itself, you may want to add
22349 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
22350 Switch} for detailed information.
22352 Here is a simple operating system declaration with a default configuration of
22353 the @code{nslcd-service-type} and a Name Service Switch configuration that
22354 consults the @code{ldap} name service last:
22357 (use-service-modules authentication)
22358 (use-modules (gnu system nss))
22364 (service nslcd-service-type)
22365 (service dhcp-client-service-type)
22367 (name-service-switch
22368 (let ((services (list (name-service (name "db"))
22369 (name-service (name "files"))
22370 (name-service (name "ldap")))))
22371 (name-service-switch
22372 (inherit %mdns-host-lookup-nss)
22373 (password services)
22376 (netgroup services)
22377 (gshadow services)))))
22380 @c %start of generated documentation for nslcd-configuration
22382 Available @code{nslcd-configuration} fields are:
22384 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
22385 The @code{nss-pam-ldapd} package to use.
22389 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
22390 The number of threads to start that can handle requests and perform LDAP
22391 queries. Each thread opens a separate connection to the LDAP server.
22392 The default is to start 5 threads.
22394 Defaults to @samp{disabled}.
22398 @deftypevr {@code{nslcd-configuration} parameter} string uid
22399 This specifies the user id with which the daemon should be run.
22401 Defaults to @samp{"nslcd"}.
22405 @deftypevr {@code{nslcd-configuration} parameter} string gid
22406 This specifies the group id with which the daemon should be run.
22408 Defaults to @samp{"nslcd"}.
22412 @deftypevr {@code{nslcd-configuration} parameter} log-option log
22413 This option controls the way logging is done via a list containing
22414 SCHEME and LEVEL. The SCHEME argument may either be the symbols
22415 @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
22416 argument is optional and specifies the log level. The log level may be
22417 one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
22418 @samp{notice}, @samp{info} or @samp{debug}. All messages with the
22419 specified log level or higher are logged.
22421 Defaults to @samp{("/var/log/nslcd" info)}.
22425 @deftypevr {@code{nslcd-configuration} parameter} list uri
22426 The list of LDAP server URIs. Normally, only the first server will be
22427 used with the following servers as fall-back.
22429 Defaults to @samp{("ldap://localhost:389/")}.
22433 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
22434 The version of the LDAP protocol to use. The default is to use the
22435 maximum version supported by the LDAP library.
22437 Defaults to @samp{disabled}.
22441 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
22442 Specifies the distinguished name with which to bind to the directory
22443 server for lookups. The default is to bind anonymously.
22445 Defaults to @samp{disabled}.
22449 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
22450 Specifies the credentials with which to bind. This option is only
22451 applicable when used with binddn.
22453 Defaults to @samp{disabled}.
22457 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
22458 Specifies the distinguished name to use when the root user tries to
22459 modify a user's password using the PAM module.
22461 Defaults to @samp{disabled}.
22465 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
22466 Specifies the credentials with which to bind if the root user tries to
22467 change a user's password. This option is only applicable when used with
22470 Defaults to @samp{disabled}.
22474 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
22475 Specifies the SASL mechanism to be used when performing SASL
22478 Defaults to @samp{disabled}.
22482 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
22483 Specifies the SASL realm to be used when performing SASL authentication.
22485 Defaults to @samp{disabled}.
22489 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
22490 Specifies the authentication identity to be used when performing SASL
22493 Defaults to @samp{disabled}.
22497 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
22498 Specifies the authorization identity to be used when performing SASL
22501 Defaults to @samp{disabled}.
22505 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
22506 Determines whether the LDAP server host name should be canonicalised. If
22507 this is enabled the LDAP library will do a reverse host name lookup. By
22508 default, it is left up to the LDAP library whether this check is
22511 Defaults to @samp{disabled}.
22515 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
22516 Set the name for the GSS-API Kerberos credentials cache.
22518 Defaults to @samp{disabled}.
22522 @deftypevr {@code{nslcd-configuration} parameter} string base
22523 The directory search base.
22525 Defaults to @samp{"dc=example,dc=com"}.
22529 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
22530 Specifies the search scope (subtree, onelevel, base or children). The
22531 default scope is subtree; base scope is almost never useful for name
22532 service lookups; children scope is not supported on all servers.
22534 Defaults to @samp{(subtree)}.
22538 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
22539 Specifies the policy for dereferencing aliases. The default policy is
22540 to never dereference aliases.
22542 Defaults to @samp{disabled}.
22546 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
22547 Specifies whether automatic referral chasing should be enabled. The
22548 default behaviour is to chase referrals.
22550 Defaults to @samp{disabled}.
22554 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
22555 This option allows for custom attributes to be looked up instead of the
22556 default RFC 2307 attributes. It is a list of maps, each consisting of
22557 the name of a map, the RFC 2307 attribute to match and the query
22558 expression for the attribute as it is available in the directory.
22560 Defaults to @samp{()}.
22564 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
22565 A list of filters consisting of the name of a map to which the filter
22566 applies and an LDAP search filter expression.
22568 Defaults to @samp{()}.
22572 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
22573 Specifies the time limit in seconds to use when connecting to the
22574 directory server. The default value is 10 seconds.
22576 Defaults to @samp{disabled}.
22580 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
22581 Specifies the time limit (in seconds) to wait for a response from the
22582 LDAP server. A value of zero, which is the default, is to wait
22583 indefinitely for searches to be completed.
22585 Defaults to @samp{disabled}.
22589 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
22590 Specifies the period if inactivity (in seconds) after which the con‐
22591 nection to the LDAP server will be closed. The default is not to time
22594 Defaults to @samp{disabled}.
22598 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
22599 Specifies the number of seconds to sleep when connecting to all LDAP
22600 servers fails. By default one second is waited between the first
22601 failure and the first retry.
22603 Defaults to @samp{disabled}.
22607 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
22608 Specifies the time after which the LDAP server is considered to be
22609 permanently unavailable. Once this time is reached retries will be done
22610 only once per this time period. The default value is 10 seconds.
22612 Defaults to @samp{disabled}.
22616 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
22617 Specifies whether to use SSL/TLS or not (the default is not to). If
22618 'start-tls is specified then StartTLS is used rather than raw LDAP over
22621 Defaults to @samp{disabled}.
22625 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
22626 Specifies what checks to perform on a server-supplied certificate. The
22627 meaning of the values is described in the ldap.conf(5) manual page.
22629 Defaults to @samp{disabled}.
22633 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
22634 Specifies the directory containing X.509 certificates for peer authen‐
22635 tication. This parameter is ignored when using GnuTLS.
22637 Defaults to @samp{disabled}.
22641 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
22642 Specifies the path to the X.509 certificate for peer authentication.
22644 Defaults to @samp{disabled}.
22648 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
22649 Specifies the path to an entropy source. This parameter is ignored when
22652 Defaults to @samp{disabled}.
22656 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
22657 Specifies the ciphers to use for TLS as a string.
22659 Defaults to @samp{disabled}.
22663 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
22664 Specifies the path to the file containing the local certificate for
22665 client TLS authentication.
22667 Defaults to @samp{disabled}.
22671 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
22672 Specifies the path to the file containing the private key for client TLS
22675 Defaults to @samp{disabled}.
22679 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
22680 Set this to a number greater than 0 to request paged results from the
22681 LDAP server in accordance with RFC2696. The default (0) is to not
22682 request paged results.
22684 Defaults to @samp{disabled}.
22688 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
22689 This option prevents group membership lookups through LDAP for the
22690 specified users. Alternatively, the value 'all-local may be used. With
22691 that value nslcd builds a full list of non-LDAP users on startup.
22693 Defaults to @samp{disabled}.
22697 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
22698 This option ensures that LDAP users with a numeric user id lower than
22699 the specified value are ignored.
22701 Defaults to @samp{disabled}.
22705 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
22706 This option specifies an offset that is added to all LDAP numeric user
22707 ids. This can be used to avoid user id collisions with local users.
22709 Defaults to @samp{disabled}.
22713 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
22714 This option specifies an offset that is added to all LDAP numeric group
22715 ids. This can be used to avoid user id collisions with local groups.
22717 Defaults to @samp{disabled}.
22721 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
22722 If this option is set, the member attribute of a group may point to
22723 another group. Members of nested groups are also returned in the higher
22724 level group and parent groups are returned when finding groups for a
22725 specific user. The default is not to perform extra searches for nested
22728 Defaults to @samp{disabled}.
22732 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
22733 If this option is set, the group member list is not retrieved when
22734 looking up groups. Lookups for finding which groups a user belongs to
22735 will remain functional so the user will likely still get the correct
22736 groups assigned on login.
22738 Defaults to @samp{disabled}.
22742 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
22743 If this option is set, functions which cause all user/group entries to
22744 be loaded from the directory will not succeed in doing so. This can
22745 dramatically reduce LDAP server load in situations where there are a
22746 great number of users and/or groups. This option is not recommended for
22747 most configurations.
22749 Defaults to @samp{disabled}.
22753 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
22754 This option can be used to specify how user and group names are verified
22755 within the system. This pattern is used to check all user and group
22756 names that are requested and returned from LDAP.
22758 Defaults to @samp{disabled}.
22762 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
22763 This specifies whether or not to perform searches using case-insensitive
22764 matching. Enabling this could open up the system to authorization
22765 bypass vulnerabilities and introduce nscd cache poisoning
22766 vulnerabilities which allow denial of service.
22768 Defaults to @samp{disabled}.
22772 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
22773 This option specifies whether password policy controls are requested and
22774 handled from the LDAP server when performing user authentication.
22776 Defaults to @samp{disabled}.
22780 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
22781 By default nslcd performs an LDAP search with the user's credentials
22782 after BIND (authentication) to ensure that the BIND operation was
22783 successful. The default search is a simple check to see if the user's
22784 DN exists. A search filter can be specified that will be used instead.
22785 It should return at least one entry.
22787 Defaults to @samp{disabled}.
22791 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
22792 This option allows flexible fine tuning of the authorisation check that
22793 should be performed. The search filter specified is executed and if any
22794 entries match, access is granted, otherwise access is denied.
22796 Defaults to @samp{disabled}.
22800 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
22801 If this option is set password modification using pam_ldap will be
22802 denied and the specified message will be presented to the user instead.
22803 The message can be used to direct the user to an alternative means of
22804 changing their password.
22806 Defaults to @samp{disabled}.
22810 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
22811 List of pam service names for which LDAP authentication should suffice.
22813 Defaults to @samp{()}.
22817 @c %end of generated documentation for nslcd-configuration
22821 @subsection Web Services
22826 The @code{(gnu services web)} module provides the Apache HTTP Server,
22827 the nginx web server, and also a fastcgi wrapper daemon.
22829 @subsubheading Apache HTTP Server
22831 @deffn {Scheme Variable} httpd-service-type
22832 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
22833 (@dfn{httpd}). The value for this service type is a
22834 @code{httpd-configuration} record.
22836 A simple example configuration is given below.
22839 (service httpd-service-type
22840 (httpd-configuration
22843 (server-name "www.example.com")
22844 (document-root "/srv/http/www.example.com")))))
22847 Other services can also extend the @code{httpd-service-type} to add to
22851 (simple-service 'www.example.com-server httpd-service-type
22855 (list (string-join '("ServerName www.example.com"
22856 "DocumentRoot /srv/http/www.example.com")
22861 The details for the @code{httpd-configuration}, @code{httpd-module},
22862 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
22865 @deffn {Data Type} httpd-configuration
22866 This data type represents the configuration for the httpd service.
22869 @item @code{package} (default: @code{httpd})
22870 The httpd package to use.
22872 @item @code{pid-file} (default: @code{"/var/run/httpd"})
22873 The pid file used by the shepherd-service.
22875 @item @code{config} (default: @code{(httpd-config-file)})
22876 The configuration file to use with the httpd service. The default value
22877 is a @code{httpd-config-file} record, but this can also be a different
22878 G-expression that generates a file, for example a @code{plain-file}. A
22879 file outside of the store can also be specified through a string.
22884 @deffn {Data Type} httpd-module
22885 This data type represents a module for the httpd service.
22889 The name of the module.
22892 The file for the module. This can be relative to the httpd package being
22893 used, the absolute location of a file, or a G-expression for a file
22894 within the store, for example @code{(file-append mod-wsgi
22895 "/modules/mod_wsgi.so")}.
22900 @defvr {Scheme Variable} %default-httpd-modules
22901 A default list of @code{httpd-module} objects.
22904 @deffn {Data Type} httpd-config-file
22905 This data type represents a configuration file for the httpd service.
22908 @item @code{modules} (default: @code{%default-httpd-modules})
22909 The modules to load. Additional modules can be added here, or loaded by
22910 additional configuration.
22912 For example, in order to handle requests for PHP files, you can use Apache’s
22913 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
22916 (service httpd-service-type
22917 (httpd-configuration
22922 (name "proxy_module")
22923 (file "modules/mod_proxy.so"))
22925 (name "proxy_fcgi_module")
22926 (file "modules/mod_proxy_fcgi.so"))
22927 %default-httpd-modules))
22928 (extra-config (list "\
22929 <FilesMatch \\.php$>
22930 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
22931 </FilesMatch>"))))))
22932 (service php-fpm-service-type
22933 (php-fpm-configuration
22934 (socket "/var/run/php-fpm.sock")
22935 (socket-group "httpd")))
22938 @item @code{server-root} (default: @code{httpd})
22939 The @code{ServerRoot} in the configuration file, defaults to the httpd
22940 package. Directives including @code{Include} and @code{LoadModule} are
22941 taken as relative to the server root.
22943 @item @code{server-name} (default: @code{#f})
22944 The @code{ServerName} in the configuration file, used to specify the
22945 request scheme, hostname and port that the server uses to identify
22948 This doesn't need to be set in the server config, and can be specified
22949 in virtual hosts. The default is @code{#f} to not specify a
22952 @item @code{document-root} (default: @code{"/srv/http"})
22953 The @code{DocumentRoot} from which files will be served.
22955 @item @code{listen} (default: @code{'("80")})
22956 The list of values for the @code{Listen} directives in the config
22957 file. The value should be a list of strings, when each string can
22958 specify the port number to listen on, and optionally the IP address and
22961 @item @code{pid-file} (default: @code{"/var/run/httpd"})
22962 The @code{PidFile} to use. This should match the @code{pid-file} set in
22963 the @code{httpd-configuration} so that the Shepherd service is
22964 configured correctly.
22966 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
22967 The @code{ErrorLog} to which the server will log errors.
22969 @item @code{user} (default: @code{"httpd"})
22970 The @code{User} which the server will answer requests as.
22972 @item @code{group} (default: @code{"httpd"})
22973 The @code{Group} which the server will answer requests as.
22975 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
22976 A flat list of strings and G-expressions which will be added to the end
22977 of the configuration file.
22979 Any values which the service is extended with will be appended to this
22985 @deffn {Data Type} httpd-virtualhost
22986 This data type represents a virtualhost configuration block for the httpd service.
22988 These should be added to the extra-config for the httpd-service.
22991 (simple-service 'www.example.com-server httpd-service-type
22995 (list (string-join '("ServerName www.example.com"
22996 "DocumentRoot /srv/http/www.example.com")
23001 @item @code{addresses-and-ports}
23002 The addresses and ports for the @code{VirtualHost} directive.
23004 @item @code{contents}
23005 The contents of the @code{VirtualHost} directive, this should be a list
23006 of strings and G-expressions.
23011 @subsubheading NGINX
23013 @deffn {Scheme Variable} nginx-service-type
23014 Service type for the @uref{https://nginx.org/,NGinx} web server. The
23015 value for this service type is a @code{<nginx-configuration>} record.
23017 A simple example configuration is given below.
23020 (service nginx-service-type
23021 (nginx-configuration
23023 (list (nginx-server-configuration
23024 (server-name '("www.example.com"))
23025 (root "/srv/http/www.example.com"))))))
23028 In addition to adding server blocks to the service configuration
23029 directly, this service can be extended by other services to add server
23030 blocks, as in this example:
23033 (simple-service 'my-extra-server nginx-service-type
23034 (list (nginx-server-configuration
23035 (root "/srv/http/extra-website")
23036 (try-files (list "$uri" "$uri/index.html")))))
23040 At startup, @command{nginx} has not yet read its configuration file, so
23041 it uses a default file to log error messages. If it fails to load its
23042 configuration file, that is where error messages are logged. After the
23043 configuration file is loaded, the default error log file changes as per
23044 configuration. In our case, startup error messages can be found in
23045 @file{/var/run/nginx/logs/error.log}, and after configuration in
23046 @file{/var/log/nginx/error.log}. The second location can be changed
23047 with the @var{log-directory} configuration option.
23049 @deffn {Data Type} nginx-configuration
23050 This data type represents the configuration for NGinx. Some
23051 configuration can be done through this and the other provided record
23052 types, or alternatively, a config file can be provided.
23055 @item @code{nginx} (default: @code{nginx})
23056 The nginx package to use.
23058 @item @code{log-directory} (default: @code{"/var/log/nginx"})
23059 The directory to which NGinx will write log files.
23061 @item @code{run-directory} (default: @code{"/var/run/nginx"})
23062 The directory in which NGinx will create a pid file, and write temporary
23065 @item @code{server-blocks} (default: @code{'()})
23066 A list of @dfn{server blocks} to create in the generated configuration
23067 file, the elements should be of type
23068 @code{<nginx-server-configuration>}.
23070 The following example would setup NGinx to serve @code{www.example.com}
23071 from the @code{/srv/http/www.example.com} directory, without using
23074 (service nginx-service-type
23075 (nginx-configuration
23077 (list (nginx-server-configuration
23078 (server-name '("www.example.com"))
23079 (root "/srv/http/www.example.com"))))))
23082 @item @code{upstream-blocks} (default: @code{'()})
23083 A list of @dfn{upstream blocks} to create in the generated configuration
23084 file, the elements should be of type
23085 @code{<nginx-upstream-configuration>}.
23087 Configuring upstreams through the @code{upstream-blocks} can be useful
23088 when combined with @code{locations} in the
23089 @code{<nginx-server-configuration>} records. The following example
23090 creates a server configuration with one location configuration, that
23091 will proxy requests to a upstream configuration, which will handle
23092 requests with two servers.
23097 (nginx-configuration
23099 (list (nginx-server-configuration
23100 (server-name '("www.example.com"))
23101 (root "/srv/http/www.example.com")
23104 (nginx-location-configuration
23106 (body '("proxy_pass http://server-proxy;"))))))))
23108 (list (nginx-upstream-configuration
23109 (name "server-proxy")
23110 (servers (list "server1.example.com"
23111 "server2.example.com")))))))
23114 @item @code{file} (default: @code{#f})
23115 If a configuration @var{file} is provided, this will be used, rather than
23116 generating a configuration file from the provided @code{log-directory},
23117 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
23118 proper operation, these arguments should match what is in @var{file} to ensure
23119 that the directories are created when the service is activated.
23121 This can be useful if you have an existing configuration file, or it's
23122 not possible to do what is required through the other parts of the
23123 nginx-configuration record.
23125 @item @code{server-names-hash-bucket-size} (default: @code{#f})
23126 Bucket size for the server names hash tables, defaults to @code{#f} to
23127 use the size of the processors cache line.
23129 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
23130 Maximum bucket size for the server names hash tables.
23132 @item @code{modules} (default: @code{'()})
23133 List of nginx dynamic modules to load. This should be a list of file
23134 names of loadable modules, as in this example:
23139 (file-append nginx-accept-language-module "\
23140 /etc/nginx/modules/ngx_http_accept_language_module.so")
23141 (file-append nginx-lua-module "\
23142 /etc/nginx/modules/ngx_http_lua_module.so")))
23145 @item @code{lua-package-path} (default: @code{'()})
23146 List of nginx lua packages to load. This should be a list of package
23147 names of loadable lua modules, as in this example:
23150 (lua-package-path (list lua-resty-core
23157 @item @code{lua-package-cpath} (default: @code{'()})
23158 List of nginx lua C packages to load. This should be a list of package
23159 names of loadable lua C modules, as in this example:
23162 (lua-package-cpath (list lua-resty-signal))
23165 @item @code{global-directives} (default: @code{'((events . ()))})
23166 Association list of global directives for the top level of the nginx
23167 configuration. Values may themselves be association lists.
23171 `((worker_processes . 16)
23173 (events . ((worker_connections . 1024)))))
23176 @item @code{extra-content} (default: @code{""})
23177 Extra content for the @code{http} block. Should be string or a string
23178 valued G-expression.
23183 @deftp {Data Type} nginx-server-configuration
23184 Data type representing the configuration of an nginx server block.
23185 This type has the following parameters:
23188 @item @code{listen} (default: @code{'("80" "443 ssl")})
23189 Each @code{listen} directive sets the address and port for IP, or the
23190 path for a UNIX-domain socket on which the server will accept requests.
23191 Both address and port, or only address or only port can be specified.
23192 An address may also be a hostname, for example:
23195 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
23198 @item @code{server-name} (default: @code{(list 'default)})
23199 A list of server names this server represents. @code{'default} represents the
23200 default server for connections matching no other server.
23202 @item @code{root} (default: @code{"/srv/http"})
23203 Root of the website nginx will serve.
23205 @item @code{locations} (default: @code{'()})
23206 A list of @dfn{nginx-location-configuration} or
23207 @dfn{nginx-named-location-configuration} records to use within this
23210 @item @code{index} (default: @code{(list "index.html")})
23211 Index files to look for when clients ask for a directory. If it cannot be found,
23212 Nginx will send the list of files in the directory.
23214 @item @code{try-files} (default: @code{'()})
23215 A list of files whose existence is checked in the specified order.
23216 @code{nginx} will use the first file it finds to process the request.
23218 @item @code{ssl-certificate} (default: @code{#f})
23219 Where to find the certificate for secure connections. Set it to @code{#f} if
23220 you don't have a certificate or you don't want to use HTTPS.
23222 @item @code{ssl-certificate-key} (default: @code{#f})
23223 Where to find the private key for secure connections. Set it to @code{#f} if
23224 you don't have a key or you don't want to use HTTPS.
23226 @item @code{server-tokens?} (default: @code{#f})
23227 Whether the server should add its configuration to response.
23229 @item @code{raw-content} (default: @code{'()})
23230 A list of raw lines added to the server block.
23235 @deftp {Data Type} nginx-upstream-configuration
23236 Data type representing the configuration of an nginx @code{upstream}
23237 block. This type has the following parameters:
23241 Name for this group of servers.
23243 @item @code{servers}
23244 Specify the addresses of the servers in the group. The address can be
23245 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
23246 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
23247 prefix @samp{unix:}. For addresses using an IP address or domain name,
23248 the default port is 80, and a different port can be specified
23254 @deftp {Data Type} nginx-location-configuration
23255 Data type representing the configuration of an nginx @code{location}
23256 block. This type has the following parameters:
23260 URI which this location block matches.
23262 @anchor{nginx-location-configuration body}
23264 Body of the location block, specified as a list of strings. This can contain
23266 configuration directives. For example, to pass requests to a upstream
23267 server group defined using an @code{nginx-upstream-configuration} block,
23268 the following directive would be specified in the body @samp{(list "proxy_pass
23269 http://upstream-name;")}.
23274 @deftp {Data Type} nginx-named-location-configuration
23275 Data type representing the configuration of an nginx named location
23276 block. Named location blocks are used for request redirection, and not
23277 used for regular request processing. This type has the following
23282 Name to identify this location block.
23285 @xref{nginx-location-configuration body}, as the body for named location
23286 blocks can be used in a similar way to the
23287 @code{nginx-location-configuration body}. One restriction is that the
23288 body of a named location block cannot contain location blocks.
23293 @subsubheading Varnish Cache
23295 Varnish is a fast cache server that sits in between web applications
23296 and end users. It proxies requests from clients and caches the
23297 accessed URLs such that multiple requests for the same resource only
23298 creates one request to the back-end.
23300 @defvr {Scheme Variable} varnish-service-type
23301 Service type for the Varnish daemon.
23304 @deftp {Data Type} varnish-configuration
23305 Data type representing the @code{varnish} service configuration.
23306 This type has the following parameters:
23309 @item @code{package} (default: @code{varnish})
23310 The Varnish package to use.
23312 @item @code{name} (default: @code{"default"})
23313 A name for this Varnish instance. Varnish will create a directory in
23314 @file{/var/varnish/} with this name and keep temporary files there. If
23315 the name starts with a forward slash, it is interpreted as an absolute
23318 Pass the @code{-n} argument to other Varnish programs to connect to the
23319 named instance, e.g.@: @command{varnishncsa -n default}.
23321 @item @code{backend} (default: @code{"localhost:8080"})
23322 The backend to use. This option has no effect if @code{vcl} is set.
23324 @item @code{vcl} (default: #f)
23325 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
23326 is @code{#f}, Varnish will proxy @code{backend} using the default
23327 configuration. Otherwise this must be a file-like object with valid
23330 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
23331 For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
23332 can do something along these lines:
23335 (define %gnu-mirror
23336 (plain-file "gnu.vcl"
23338 backend gnu @{ .host = \"www.gnu.org\"; @}"))
23342 (services (cons (service varnish-service-type
23343 (varnish-configuration
23345 (vcl %gnu-mirror)))
23349 The configuration of an already running Varnish instance can be inspected
23350 and changed using the @command{varnishadm} program.
23352 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
23353 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
23354 comprehensive documentation on Varnish and its configuration language.
23356 @item @code{listen} (default: @code{'("localhost:80")})
23357 List of addresses Varnish will listen on.
23359 @item @code{storage} (default: @code{'("malloc,128m")})
23360 List of storage backends that will be available in VCL.
23362 @item @code{parameters} (default: @code{'()})
23363 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
23365 @item @code{extra-options} (default: @code{'()})
23366 Additional arguments to pass to the @command{varnishd} process.
23371 @subsubheading Patchwork
23373 Patchwork is a patch tracking system. It can collect patches sent to a
23374 mailing list, and display them in a web interface.
23376 @defvr {Scheme Variable} patchwork-service-type
23377 Service type for Patchwork.
23380 The following example is an example of a minimal service for Patchwork, for
23381 the @code{patchwork.example.com} domain.
23384 (service patchwork-service-type
23385 (patchwork-configuration
23386 (domain "patchwork.example.com")
23388 (patchwork-settings-module
23389 (allowed-hosts (list domain))
23390 (default-from-email "patchwork@@patchwork.example.com")))
23391 (getmail-retriever-config
23392 (getmail-retriever-configuration
23393 (type "SimpleIMAPSSLRetriever")
23394 (server "imap.example.com")
23396 (username "patchwork")
23398 (list (file-append coreutils "/bin/cat")
23399 "/etc/getmail-patchwork-imap-password"))
23401 '((mailboxes . ("Patches"))))))))
23405 There are three records for configuring the Patchwork service. The
23406 @code{<patchwork-configuration>} relates to the configuration for Patchwork
23407 within the HTTPD service.
23409 The @code{settings-module} field within the @code{<patchwork-configuration>}
23410 record can be populated with the @code{<patchwork-settings-module>} record,
23411 which describes a settings module that is generated within the Guix store.
23413 For the @code{database-configuration} field within the
23414 @code{<patchwork-settings-module>}, the
23415 @code{<patchwork-database-configuration>} must be used.
23417 @deftp {Data Type} patchwork-configuration
23418 Data type representing the Patchwork service configuration. This type has the
23419 following parameters:
23422 @item @code{patchwork} (default: @code{patchwork})
23423 The Patchwork package to use.
23425 @item @code{domain}
23426 The domain to use for Patchwork, this is used in the HTTPD service virtual
23429 @item @code{settings-module}
23430 The settings module to use for Patchwork. As a Django application, Patchwork
23431 is configured with a Python module containing the settings. This can either be
23432 an instance of the @code{<patchwork-settings-module>} record, any other record
23433 that represents the settings in the store, or a directory outside of the
23436 @item @code{static-path} (default: @code{"/static/"})
23437 The path under which the HTTPD service should serve the static files.
23439 @item @code{getmail-retriever-config}
23440 The getmail-retriever-configuration record value to use with
23441 Patchwork. Getmail will be configured with this value, the messages will be
23442 delivered to Patchwork.
23447 @deftp {Data Type} patchwork-settings-module
23448 Data type representing a settings module for Patchwork. Some of these
23449 settings relate directly to Patchwork, but others relate to Django, the web
23450 framework used by Patchwork, or the Django Rest Framework library. This type
23451 has the following parameters:
23454 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
23455 The database connection settings used for Patchwork. See the
23456 @code{<patchwork-database-configuration>} record type for more information.
23458 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
23459 Patchwork, as a Django web application uses a secret key for cryptographically
23460 signing values. This file should contain a unique unpredictable value.
23462 If this file does not exist, it will be created and populated with a random
23463 value by the patchwork-setup shepherd service.
23465 This setting relates to Django.
23467 @item @code{allowed-hosts}
23468 A list of valid hosts for this Patchwork service. This should at least include
23469 the domain specified in the @code{<patchwork-configuration>} record.
23471 This is a Django setting.
23473 @item @code{default-from-email}
23474 The email address from which Patchwork should send email by default.
23476 This is a Patchwork setting.
23478 @item @code{static-url} (default: @code{#f})
23479 The URL to use when serving static assets. It can be part of a URL, or a full
23480 URL, but must end in a @code{/}.
23482 If the default value is used, the @code{static-path} value from the
23483 @code{<patchwork-configuration>} record will be used.
23485 This is a Django setting.
23487 @item @code{admins} (default: @code{'()})
23488 Email addresses to send the details of errors that occur. Each value should
23489 be a list containing two elements, the name and then the email address.
23491 This is a Django setting.
23493 @item @code{debug?} (default: @code{#f})
23494 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
23495 messages will be shown.
23497 This is a Django setting.
23499 @item @code{enable-rest-api?} (default: @code{#t})
23500 Whether to enable the Patchwork REST API.
23502 This is a Patchwork setting.
23504 @item @code{enable-xmlrpc?} (default: @code{#t})
23505 Whether to enable the XML RPC API.
23507 This is a Patchwork setting.
23509 @item @code{force-https-links?} (default: @code{#t})
23510 Whether to use HTTPS links on Patchwork pages.
23512 This is a Patchwork setting.
23514 @item @code{extra-settings} (default: @code{""})
23515 Extra code to place at the end of the Patchwork settings module.
23520 @deftp {Data Type} patchwork-database-configuration
23521 Data type representing the database configuration for Patchwork.
23524 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
23525 The database engine to use.
23527 @item @code{name} (default: @code{"patchwork"})
23528 The name of the database to use.
23530 @item @code{user} (default: @code{"httpd"})
23531 The user to connect to the database as.
23533 @item @code{password} (default: @code{""})
23534 The password to use when connecting to the database.
23536 @item @code{host} (default: @code{""})
23537 The host to make the database connection to.
23539 @item @code{port} (default: @code{""})
23540 The port on which to connect to the database.
23545 @subsubheading Mumi
23547 @cindex Mumi, Debbugs Web interface
23548 @cindex Debbugs, Mumi Web interface
23549 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
23550 Web interface to the Debbugs bug tracker, by default for
23551 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
23552 but it also fetches and indexes mail retrieved from Debbugs.
23554 @defvr {Scheme Variable} mumi-service-type
23555 This is the service type for Mumi.
23558 @deftp {Data Type} mumi-configuration
23559 Data type representing the Mumi service configuration. This type has the
23563 @item @code{mumi} (default: @code{mumi})
23564 The Mumi package to use.
23566 @item @code{mailer?} (default: @code{#true})
23567 Whether to enable or disable the mailer component.
23569 @item @code{mumi-configuration-sender}
23570 The email address used as the sender for comments.
23572 @item @code{mumi-configuration-smtp}
23573 A URI to configure the SMTP settings for Mailutils. This could be
23574 something like @code{sendmail:///path/to/bin/msmtp} or any other URI
23575 supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
23576 mailutils, GNU@tie{}Mailutils}.
23582 @subsubheading FastCGI
23585 FastCGI is an interface between the front-end and the back-end of a web
23586 service. It is a somewhat legacy facility; new web services should
23587 generally just talk HTTP between the front-end and the back-end.
23588 However there are a number of back-end services such as PHP or the
23589 optimized HTTP Git repository access that use FastCGI, so we have
23590 support for it in Guix.
23592 To use FastCGI, you configure the front-end web server (e.g., nginx) to
23593 dispatch some subset of its requests to the fastcgi backend, which
23594 listens on a local TCP or UNIX socket. There is an intermediary
23595 @code{fcgiwrap} program that sits between the actual backend process and
23596 the web server. The front-end indicates which backend program to run,
23597 passing that information to the @code{fcgiwrap} process.
23599 @defvr {Scheme Variable} fcgiwrap-service-type
23600 A service type for the @code{fcgiwrap} FastCGI proxy.
23603 @deftp {Data Type} fcgiwrap-configuration
23604 Data type representing the configuration of the @code{fcgiwrap} service.
23605 This type has the following parameters:
23607 @item @code{package} (default: @code{fcgiwrap})
23608 The fcgiwrap package to use.
23610 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
23611 The socket on which the @code{fcgiwrap} process should listen, as a
23612 string. Valid @var{socket} values include
23613 @code{unix:@var{/path/to/unix/socket}},
23614 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
23615 @code{tcp6:[@var{ipv6_addr}]:port}.
23617 @item @code{user} (default: @code{fcgiwrap})
23618 @itemx @code{group} (default: @code{fcgiwrap})
23619 The user and group names, as strings, under which to run the
23620 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
23621 the user asks for the specific user or group names @code{fcgiwrap} that
23622 the corresponding user and/or group is present on the system.
23624 It is possible to configure a FastCGI-backed web service to pass HTTP
23625 authentication information from the front-end to the back-end, and to
23626 allow @code{fcgiwrap} to run the back-end process as a corresponding
23627 local user. To enable this capability on the back-end, run
23628 @code{fcgiwrap} as the @code{root} user and group. Note that this
23629 capability also has to be configured on the front-end as well.
23634 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
23635 with some additional features useful for sites of any size.
23637 These features include:
23639 @item Adaptive process spawning
23640 @item Basic statistics (similar to Apache's mod_status)
23641 @item Advanced process management with graceful stop/start
23642 @item Ability to start workers with different uid/gid/chroot/environment
23643 and different php.ini (replaces safe_mode)
23644 @item Stdout & stderr logging
23645 @item Emergency restart in case of accidental opcode cache destruction
23646 @item Accelerated upload support
23647 @item Support for a "slowlog"
23648 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
23649 a special function to finish request & flush all data while continuing to do
23650 something time-consuming (video converting, stats processing, etc.)
23652 ...@: and much more.
23654 @defvr {Scheme Variable} php-fpm-service-type
23655 A Service type for @code{php-fpm}.
23658 @deftp {Data Type} php-fpm-configuration
23659 Data Type for php-fpm service configuration.
23661 @item @code{php} (default: @code{php})
23662 The php package to use.
23663 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
23664 The address on which to accept FastCGI requests. Valid syntaxes are:
23666 @item @code{"ip.add.re.ss:port"}
23667 Listen on a TCP socket to a specific address on a specific port.
23668 @item @code{"port"}
23669 Listen on a TCP socket to all addresses on a specific port.
23670 @item @code{"/path/to/unix/socket"}
23671 Listen on a unix socket.
23674 @item @code{user} (default: @code{php-fpm})
23675 User who will own the php worker processes.
23676 @item @code{group} (default: @code{php-fpm})
23677 Group of the worker processes.
23678 @item @code{socket-user} (default: @code{php-fpm})
23679 User who can speak to the php-fpm socket.
23680 @item @code{socket-group} (default: @code{nginx})
23681 Group that can speak to the php-fpm socket.
23682 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
23683 The process id of the php-fpm process is written to this file
23684 once the service has started.
23685 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
23686 Log for the php-fpm master process.
23687 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
23688 Detailed settings for the php-fpm process manager.
23691 @item @code{<php-fpm-dynamic-process-manager-configuration>}
23692 @item @code{<php-fpm-static-process-manager-configuration>}
23693 @item @code{<php-fpm-on-demand-process-manager-configuration>}
23695 @item @code{display-errors} (default @code{#f})
23696 Determines whether php errors and warning should be sent to clients
23697 and displayed in their browsers.
23698 This is useful for local php development, but a security risk for public sites,
23699 as error messages can reveal passwords and personal data.
23700 @item @code{timezone} (default @code{#f})
23701 Specifies @code{php_admin_value[date.timezone]} parameter.
23702 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
23703 This file will log the @code{stderr} outputs of php worker processes.
23704 Can be set to @code{#f} to disable logging.
23705 @item @code{file} (default @code{#f})
23706 An optional override of the whole configuration.
23707 You can use the @code{mixed-text-file} function or an absolute filepath for it.
23708 @item @code{php-ini-file} (default @code{#f})
23709 An optional override of the default php settings.
23710 It may be any ``file-like'' object (@pxref{G-Expressions, file-like objects}).
23711 You can use the @code{mixed-text-file} function or an absolute filepath for it.
23713 For local development it is useful to set a higher timeout and memory
23714 limit for spawned php processes. This be accomplished with the
23715 following operating system configuration snippet:
23717 (define %local-php-ini
23718 (plain-file "php.ini"
23720 max_execution_time = 1800"))
23724 (services (cons (service php-fpm-service-type
23725 (php-fpm-configuration
23726 (php-ini-file %local-php-ini)))
23730 Consult the @url{https://www.php.net/manual/en/ini.core.php,core php.ini
23731 directives} for comprehensive documentation on the acceptable
23732 @file{php.ini} directives.
23736 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
23737 Data Type for the @code{dynamic} php-fpm process manager. With the
23738 @code{dynamic} process manager, spare worker processes are kept around
23739 based on it's configured limits.
23741 @item @code{max-children} (default: @code{5})
23742 Maximum of worker processes.
23743 @item @code{start-servers} (default: @code{2})
23744 How many worker processes should be started on start-up.
23745 @item @code{min-spare-servers} (default: @code{1})
23746 How many spare worker processes should be kept around at minimum.
23747 @item @code{max-spare-servers} (default: @code{3})
23748 How many spare worker processes should be kept around at maximum.
23752 @deftp {Data type} php-fpm-static-process-manager-configuration
23753 Data Type for the @code{static} php-fpm process manager. With the
23754 @code{static} process manager, an unchanging number of worker processes
23757 @item @code{max-children} (default: @code{5})
23758 Maximum of worker processes.
23762 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
23763 Data Type for the @code{on-demand} php-fpm process manager. With the
23764 @code{on-demand} process manager, worker processes are only created as
23767 @item @code{max-children} (default: @code{5})
23768 Maximum of worker processes.
23769 @item @code{process-idle-timeout} (default: @code{10})
23770 The time in seconds after which a process with no requests is killed.
23775 @deffn {Scheme Procedure} nginx-php-location @
23776 [#:nginx-package nginx] @
23777 [socket (string-append "/var/run/php" @
23778 (version-major (package-version php)) @
23780 A helper function to quickly add php to an @code{nginx-server-configuration}.
23783 A simple services setup for nginx with php can look like this:
23785 (services (cons* (service dhcp-client-service-type)
23786 (service php-fpm-service-type)
23787 (service nginx-service-type
23788 (nginx-server-configuration
23789 (server-name '("example.com"))
23790 (root "/srv/http/")
23792 (list (nginx-php-location)))
23794 (ssl-certificate #f)
23795 (ssl-certificate-key #f)))
23799 @cindex cat-avatar-generator
23800 The cat avatar generator is a simple service to demonstrate the use of php-fpm
23801 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
23802 the hash of a user's email address.
23804 @deffn {Scheme Procedure} cat-avatar-generator-service @
23805 [#:cache-dir "/var/cache/cat-avatar-generator"] @
23806 [#:package cat-avatar-generator] @
23807 [#:configuration (nginx-server-configuration)]
23808 Returns an nginx-server-configuration that inherits @code{configuration}. It
23809 extends the nginx configuration to add a server block that serves @code{package},
23810 a version of cat-avatar-generator. During execution, cat-avatar-generator will
23811 be able to use @code{cache-dir} as its cache directory.
23814 A simple setup for cat-avatar-generator can look like this:
23816 (services (cons* (cat-avatar-generator-service
23818 (nginx-server-configuration
23819 (server-name '("example.com"))))
23824 @subsubheading Hpcguix-web
23826 @cindex hpcguix-web
23827 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
23828 program is a customizable web interface to browse Guix packages,
23829 initially designed for users of high-performance computing (HPC)
23832 @defvr {Scheme Variable} hpcguix-web-service-type
23833 The service type for @code{hpcguix-web}.
23836 @deftp {Data Type} hpcguix-web-configuration
23837 Data type for the hpcguix-web service configuration.
23841 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
23842 configuration. The main items available in this spec are:
23845 @item @code{title-prefix} (default: @code{"hpcguix | "})
23846 The page title prefix.
23848 @item @code{guix-command} (default: @code{"guix"})
23849 The @command{guix} command.
23851 @item @code{package-filter-proc} (default: @code{(const #t)})
23852 A procedure specifying how to filter packages that are displayed.
23854 @item @code{package-page-extension-proc} (default: @code{(const '())})
23855 Extension package for @code{hpcguix-web}.
23857 @item @code{menu} (default: @code{'()})
23858 Additional entry in page @code{menu}.
23860 @item @code{channels} (default: @code{%default-channels})
23861 List of channels from which the package list is built (@pxref{Channels}).
23863 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
23864 The expiration time, in seconds, after which the package list is rebuilt from
23865 the latest instances of the given channels.
23868 See the hpcguix-web repository for a
23869 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
23872 @item @code{package} (default: @code{hpcguix-web})
23873 The hpcguix-web package to use.
23877 A typical hpcguix-web service declaration looks like this:
23880 (service hpcguix-web-service-type
23881 (hpcguix-web-configuration
23883 #~(define site-config
23884 (hpcweb-configuration
23885 (title-prefix "Guix-HPC - ")
23886 (menu '(("/about" "ABOUT"))))))))
23890 The hpcguix-web service periodically updates the package list it publishes by
23891 pulling channels from Git. To that end, it needs to access X.509 certificates
23892 so that it can authenticate Git servers when communicating over HTTPS, and it
23893 assumes that @file{/etc/ssl/certs} contains those certificates.
23895 Thus, make sure to add @code{nss-certs} or another certificate package to the
23896 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
23897 more information on X.509 certificates.
23900 @subsubheading gmnisrv
23903 The @uref{https://git.sr.ht/~sircmpwn/gmnisrv, gmnisrv} program is a
23904 simple @uref{https://gemini.circumlunar.space/, Gemini} protocol server.
23906 @deffn {Scheme Variable} gmnisrv-service-type
23907 This is the type of the gmnisrv service, whose value should be a
23908 @code{gmnisrv-configuration} object, as in this example:
23911 (service gmnisrv-service-type
23912 (gmnisrv-configuration
23913 (config-file (local-file "./my-gmnisrv.ini"))))
23917 @deftp {Data Type} gmnisrv-configuration
23918 Data type representing the configuration of gmnisrv.
23921 @item @code{package} (default: @var{gmnisrv})
23922 Package object of the gmnisrv server.
23924 @item @code{config-file} (default: @code{%default-gmnisrv-config-file})
23925 File-like object of the gmnisrv configuration file to use. The default
23926 configuration listens on port 1965 and serves files from
23927 @file{/srv/gemini}. Certificates are stored in
23928 @file{/var/lib/gemini/certs}. For more information, run @command{man
23929 gmnisrv} and @command{man gmnisrv.ini}.
23934 @node Certificate Services
23935 @subsection Certificate Services
23938 @cindex HTTP, HTTPS
23939 @cindex Let's Encrypt
23940 @cindex TLS certificates
23941 The @code{(gnu services certbot)} module provides a service to
23942 automatically obtain a valid TLS certificate from the Let's Encrypt
23943 certificate authority. These certificates can then be used to serve
23944 content securely over HTTPS or other TLS-based protocols, with the
23945 knowledge that the client will be able to verify the server's
23948 @url{https://letsencrypt.org/, Let's Encrypt} provides the
23949 @code{certbot} tool to automate the certification process. This tool
23950 first securely generates a key on the server. It then makes a request
23951 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
23952 checks that the request originates from the host in question by using a
23953 challenge-response protocol, requiring the server to provide its
23954 response over HTTP. If that protocol completes successfully, the CA
23955 signs the key, resulting in a certificate. That certificate is valid
23956 for a limited period of time, and therefore to continue to provide TLS
23957 services, the server needs to periodically ask the CA to renew its
23960 The certbot service automates this process: the initial key
23961 generation, the initial certification request to the Let's Encrypt
23962 service, the web server challenge/response integration, writing the
23963 certificate to disk, the automated periodic renewals, and the deployment
23964 tasks associated with the renewal (e.g.@: reloading services, copying keys
23965 with different permissions).
23967 Certbot is run twice a day, at a random minute within the hour. It
23968 won't do anything until your certificates are due for renewal or
23969 revoked, but running it regularly would give your service a chance of
23970 staying online in case a Let's Encrypt-initiated revocation happened for
23973 By using this service, you agree to the ACME Subscriber Agreement, which
23974 can be found there:
23975 @url{https://acme-v01.api.letsencrypt.org/directory}.
23977 @defvr {Scheme Variable} certbot-service-type
23978 A service type for the @code{certbot} Let's Encrypt client. Its value
23979 must be a @code{certbot-configuration} record as in this example:
23982 (define %nginx-deploy-hook
23984 "nginx-deploy-hook"
23985 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
23986 (kill pid SIGHUP))))
23988 (service certbot-service-type
23989 (certbot-configuration
23990 (email "foo@@example.net")
23993 (certificate-configuration
23994 (domains '("example.net" "www.example.net"))
23995 (deploy-hook %nginx-deploy-hook))
23996 (certificate-configuration
23997 (domains '("bar.example.net")))))))
24000 See below for details about @code{certbot-configuration}.
24003 @deftp {Data Type} certbot-configuration
24004 Data type representing the configuration of the @code{certbot} service.
24005 This type has the following parameters:
24008 @item @code{package} (default: @code{certbot})
24009 The certbot package to use.
24011 @item @code{webroot} (default: @code{/var/www})
24012 The directory from which to serve the Let's Encrypt challenge/response
24015 @item @code{certificates} (default: @code{()})
24016 A list of @code{certificates-configuration}s for which to generate
24017 certificates and request signatures. Each certificate has a @code{name}
24018 and several @code{domains}.
24020 @item @code{email} (default: @code{#f})
24021 Optional email address used for registration and recovery contact.
24022 Setting this is encouraged as it allows you to receive important
24023 notifications about the account and issued certificates.
24025 @item @code{server} (default: @code{#f})
24026 Optional URL of ACME server. Setting this overrides certbot's default,
24027 which is the Let's Encrypt server.
24029 @item @code{rsa-key-size} (default: @code{2048})
24030 Size of the RSA key.
24032 @item @code{default-location} (default: @i{see below})
24033 The default @code{nginx-location-configuration}. Because @code{certbot}
24034 needs to be able to serve challenges and responses, it needs to be able
24035 to run a web server. It does so by extending the @code{nginx} web
24036 service with an @code{nginx-server-configuration} listening on the
24037 @var{domains} on port 80, and which has a
24038 @code{nginx-location-configuration} for the @code{/.well-known/} URI
24039 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
24040 these nginx configuration data types.
24042 Requests to other URL paths will be matched by the
24043 @code{default-location}, which if present is added to all
24044 @code{nginx-server-configuration}s.
24046 By default, the @code{default-location} will issue a redirect from
24047 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
24048 you to define what to serve on your site via @code{https}.
24050 Pass @code{#f} to not issue a default location.
24054 @deftp {Data Type} certificate-configuration
24055 Data type representing the configuration of a certificate.
24056 This type has the following parameters:
24059 @item @code{name} (default: @i{see below})
24060 This name is used by Certbot for housekeeping and in file paths; it
24061 doesn't affect the content of the certificate itself. To see
24062 certificate names, run @code{certbot certificates}.
24064 Its default is the first provided domain.
24066 @item @code{domains} (default: @code{()})
24067 The first domain provided will be the subject CN of the certificate, and
24068 all domains will be Subject Alternative Names on the certificate.
24070 @item @code{challenge} (default: @code{#f})
24071 The challenge type that has to be run by certbot. If @code{#f} is specified,
24072 default to the HTTP challenge. If a value is specified, defaults to the
24073 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
24074 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
24075 and gives Let's Encrypt permission to log the public IP address of the
24076 requesting machine.
24078 @item @code{authentication-hook} (default: @code{#f})
24079 Command to be run in a shell once for each certificate challenge to be
24080 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
24081 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
24082 contains the validation string and @code{$CERTBOT_TOKEN} contains the
24083 file name of the resource requested when performing an HTTP-01 challenge.
24085 @item @code{cleanup-hook} (default: @code{#f})
24086 Command to be run in a shell once for each certificate challenge that
24087 have been answered by the @code{auth-hook}. For this command, the shell
24088 variables available in the @code{auth-hook} script are still available, and
24089 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
24090 of the @code{auth-hook} script.
24092 @item @code{deploy-hook} (default: @code{#f})
24093 Command to be run in a shell once for each successfully issued
24094 certificate. For this command, the shell variable
24095 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
24096 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
24097 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
24098 contain a space-delimited list of renewed certificate domains (for
24099 example, @samp{"example.com www.example.com"}.
24104 For each @code{certificate-configuration}, the certificate is saved to
24105 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
24106 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
24108 @subsection DNS Services
24109 @cindex DNS (domain name system)
24110 @cindex domain name system (DNS)
24112 The @code{(gnu services dns)} module provides services related to the
24113 @dfn{domain name system} (DNS). It provides a server service for hosting
24114 an @emph{authoritative} DNS server for multiple zones, slave or master.
24115 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
24116 caching and forwarding DNS server for the LAN, which uses
24117 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
24119 @subsubheading Knot Service
24121 An example configuration of an authoritative server for two zones, one master
24125 (define-zone-entries example.org.zone
24126 ;; Name TTL Class Type Data
24127 ("@@" "" "IN" "A" "127.0.0.1")
24128 ("@@" "" "IN" "NS" "ns")
24129 ("ns" "" "IN" "A" "127.0.0.1"))
24131 (define master-zone
24132 (knot-zone-configuration
24133 (domain "example.org")
24135 (origin "example.org")
24136 (entries example.org.zone)))))
24139 (knot-zone-configuration
24140 (domain "plop.org")
24141 (dnssec-policy "default")
24142 (master (list "plop-master"))))
24144 (define plop-master
24145 (knot-remote-configuration
24147 (address (list "208.76.58.171"))))
24151 (services (cons* (service knot-service-type
24152 (knot-configuration
24153 (remotes (list plop-master))
24154 (zones (list master-zone slave-zone))))
24159 @deffn {Scheme Variable} knot-service-type
24160 This is the type for the Knot DNS server.
24162 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
24163 zones, that is to say domain names you would buy from a registrar. This server
24164 is not a resolver, meaning that it can only resolve names for which it is
24165 authoritative. This server can be configured to serve zones as a master server
24166 or a slave server as a per-zone basis. Slave zones will get their data from
24167 masters, and will serve it as an authoritative server. From the point of view
24168 of a resolver, there is no difference between master and slave.
24170 The following data types are used to configure the Knot DNS server:
24173 @deftp {Data Type} knot-key-configuration
24174 Data type representing a key.
24175 This type has the following parameters:
24178 @item @code{id} (default: @code{""})
24179 An identifier for other configuration fields to refer to this key. IDs must
24180 be unique and must not be empty.
24182 @item @code{algorithm} (default: @code{#f})
24183 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
24184 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
24185 and @code{'hmac-sha512}.
24187 @item @code{secret} (default: @code{""})
24188 The secret key itself.
24193 @deftp {Data Type} knot-acl-configuration
24194 Data type representing an Access Control List (ACL) configuration.
24195 This type has the following parameters:
24198 @item @code{id} (default: @code{""})
24199 An identifier for other configuration fields to refer to this key. IDs must be
24200 unique and must not be empty.
24202 @item @code{address} (default: @code{'()})
24203 An ordered list of IP addresses, network subnets, or network ranges represented
24204 with strings. The query must match one of them. Empty value means that
24205 address match is not required.
24207 @item @code{key} (default: @code{'()})
24208 An ordered list of references to keys represented with strings. The string
24209 must match a key ID defined in a @code{knot-key-configuration}. No key means
24210 that a key is not require to match that ACL.
24212 @item @code{action} (default: @code{'()})
24213 An ordered list of actions that are permitted or forbidden by this ACL. Possible
24214 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
24215 and @code{'update}.
24217 @item @code{deny?} (default: @code{#f})
24218 When true, the ACL defines restrictions. Listed actions are forbidden. When
24219 false, listed actions are allowed.
24224 @deftp {Data Type} zone-entry
24225 Data type representing a record entry in a zone file.
24226 This type has the following parameters:
24229 @item @code{name} (default: @code{"@@"})
24230 The name of the record. @code{"@@"} refers to the origin of the zone. Names
24231 are relative to the origin of the zone. For example, in the @code{example.org}
24232 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
24233 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
24234 refers to @code{ns.example.org}.
24236 @item @code{ttl} (default: @code{""})
24237 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
24239 @item @code{class} (default: @code{"IN"})
24240 The class of the record. Knot currently supports only @code{"IN"} and
24241 partially @code{"CH"}.
24243 @item @code{type} (default: @code{"A"})
24244 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
24245 address), NS (Name Server) and MX (Mail eXchange). Many other types are
24248 @item @code{data} (default: @code{""})
24249 The data contained in the record. For instance an IP address associated with
24250 an A record, or a domain name associated with an NS record. Remember that
24251 domain names are relative to the origin unless they end with a dot.
24256 @deftp {Data Type} zone-file
24257 Data type representing the content of a zone file.
24258 This type has the following parameters:
24261 @item @code{entries} (default: @code{'()})
24262 The list of entries. The SOA record is taken care of, so you don't need to
24263 put it in the list of entries. This list should probably contain an entry
24264 for your primary authoritative DNS server. Other than using a list of entries
24265 directly, you can use @code{define-zone-entries} to define a object containing
24266 the list of entries more easily, that you can later pass to the @code{entries}
24267 field of the @code{zone-file}.
24269 @item @code{origin} (default: @code{""})
24270 The name of your zone. This parameter cannot be empty.
24272 @item @code{ns} (default: @code{"ns"})
24273 The domain of your primary authoritative DNS server. The name is relative to
24274 the origin, unless it ends with a dot. It is mandatory that this primary
24275 DNS server corresponds to an NS record in the zone and that it is associated
24276 to an IP address in the list of entries.
24278 @item @code{mail} (default: @code{"hostmaster"})
24279 An email address people can contact you at, as the owner of the zone. This
24280 is translated as @code{<mail>@@<origin>}.
24282 @item @code{serial} (default: @code{1})
24283 The serial number of the zone. As this is used to keep track of changes by
24284 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
24285 Always increment it when you make a change in your zone.
24287 @item @code{refresh} (default: @code{(* 2 24 3600)})
24288 The frequency at which slaves will do a zone transfer. This value is a number
24289 of seconds. It can be computed by multiplications or with
24290 @code{(string->duration)}.
24292 @item @code{retry} (default: @code{(* 15 60)})
24293 The period after which a slave will retry to contact its master when it fails
24294 to do so a first time.
24296 @item @code{expiry} (default: @code{(* 14 24 3600)})
24297 Default TTL of records. Existing records are considered correct for at most
24298 this amount of time. After this period, resolvers will invalidate their cache
24299 and check again that it still exists.
24301 @item @code{nx} (default: @code{3600})
24302 Default TTL of inexistant records. This delay is usually short because you want
24303 your new domains to reach everyone quickly.
24308 @deftp {Data Type} knot-remote-configuration
24309 Data type representing a remote configuration.
24310 This type has the following parameters:
24313 @item @code{id} (default: @code{""})
24314 An identifier for other configuration fields to refer to this remote. IDs must
24315 be unique and must not be empty.
24317 @item @code{address} (default: @code{'()})
24318 An ordered list of destination IP addresses. Addresses are tried in sequence.
24319 An optional port can be given with the @@ separator. For instance:
24320 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
24322 @item @code{via} (default: @code{'()})
24323 An ordered list of source IP addresses. An empty list will have Knot choose
24324 an appropriate source IP. An optional port can be given with the @@ separator.
24325 The default is to choose at random.
24327 @item @code{key} (default: @code{#f})
24328 A reference to a key, that is a string containing the identifier of a key
24329 defined in a @code{knot-key-configuration} field.
24334 @deftp {Data Type} knot-keystore-configuration
24335 Data type representing a keystore to hold dnssec keys.
24336 This type has the following parameters:
24339 @item @code{id} (default: @code{""})
24340 The id of the keystore. It must not be empty.
24342 @item @code{backend} (default: @code{'pem})
24343 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
24345 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
24346 The configuration string of the backend. An example for the PKCS#11 is:
24347 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
24348 For the pem backend, the string represents a path in the file system.
24353 @deftp {Data Type} knot-policy-configuration
24354 Data type representing a dnssec policy. Knot DNS is able to automatically
24355 sign your zones. It can either generate and manage your keys automatically or
24356 use keys that you generate.
24358 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
24359 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
24360 zone. In order to be trusted, the KSK needs to be present in the parent zone
24361 (usually a top-level domain). If your registrar supports dnssec, you will
24362 have to send them your KSK's hash so they can add a DS record in their zone.
24363 This is not automated and need to be done each time you change your KSK.
24365 The policy also defines the lifetime of keys. Usually, ZSK can be changed
24366 easily and use weaker cryptographic functions (they use lower parameters) in
24367 order to sign records quickly, so they are changed often. The KSK however
24368 requires manual interaction with the registrar, so they are changed less often
24369 and use stronger parameters because they sign only one record.
24371 This type has the following parameters:
24374 @item @code{id} (default: @code{""})
24375 The id of the policy. It must not be empty.
24377 @item @code{keystore} (default: @code{"default"})
24378 A reference to a keystore, that is a string containing the identifier of a
24379 keystore defined in a @code{knot-keystore-configuration} field. The
24380 @code{"default"} identifier means the default keystore (a kasp database that
24381 was setup by this service).
24383 @item @code{manual?} (default: @code{#f})
24384 Whether the key management is manual or automatic.
24386 @item @code{single-type-signing?} (default: @code{#f})
24387 When @code{#t}, use the Single-Type Signing Scheme.
24389 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
24390 An algorithm of signing keys and issued signatures.
24392 @item @code{ksk-size} (default: @code{256})
24393 The length of the KSK. Note that this value is correct for the default
24394 algorithm, but would be unsecure for other algorithms.
24396 @item @code{zsk-size} (default: @code{256})
24397 The length of the ZSK. Note that this value is correct for the default
24398 algorithm, but would be unsecure for other algorithms.
24400 @item @code{dnskey-ttl} (default: @code{'default})
24401 The TTL value for DNSKEY records added into zone apex. The special
24402 @code{'default} value means same as the zone SOA TTL.
24404 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
24405 The period between ZSK publication and the next rollover initiation.
24407 @item @code{propagation-delay} (default: @code{(* 24 3600)})
24408 An extra delay added for each key rollover step. This value should be high
24409 enough to cover propagation of data from the master server to all slaves.
24411 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
24412 A validity period of newly issued signatures.
24414 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
24415 A period how long before a signature expiration the signature will be refreshed.
24417 @item @code{nsec3?} (default: @code{#f})
24418 When @code{#t}, NSEC3 will be used instead of NSEC.
24420 @item @code{nsec3-iterations} (default: @code{5})
24421 The number of additional times the hashing is performed.
24423 @item @code{nsec3-salt-length} (default: @code{8})
24424 The length of a salt field in octets, which is appended to the original owner
24425 name before hashing.
24427 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
24428 The validity period of newly issued salt field.
24433 @deftp {Data Type} knot-zone-configuration
24434 Data type representing a zone served by Knot.
24435 This type has the following parameters:
24438 @item @code{domain} (default: @code{""})
24439 The domain served by this configuration. It must not be empty.
24441 @item @code{file} (default: @code{""})
24442 The file where this zone is saved. This parameter is ignored by master zones.
24443 Empty means default location that depends on the domain name.
24445 @item @code{zone} (default: @code{(zone-file)})
24446 The content of the zone file. This parameter is ignored by slave zones. It
24447 must contain a zone-file record.
24449 @item @code{master} (default: @code{'()})
24450 A list of master remotes. When empty, this zone is a master. When set, this
24451 zone is a slave. This is a list of remotes identifiers.
24453 @item @code{ddns-master} (default: @code{#f})
24454 The main master. When empty, it defaults to the first master in the list of
24457 @item @code{notify} (default: @code{'()})
24458 A list of slave remote identifiers.
24460 @item @code{acl} (default: @code{'()})
24461 A list of acl identifiers.
24463 @item @code{semantic-checks?} (default: @code{#f})
24464 When set, this adds more semantic checks to the zone.
24466 @item @code{disable-any?} (default: @code{#f})
24467 When set, this forbids queries of the ANY type.
24469 @item @code{zonefile-sync} (default: @code{0})
24470 The delay between a modification in memory and on disk. 0 means immediate
24473 @item @code{zonefile-load} (default: @code{#f})
24474 The way the zone file contents are applied during zone load. Possible values
24478 @item @code{#f} for using the default value from Knot,
24479 @item @code{'none} for not using the zone file at all,
24480 @item @code{'difference} for computing the difference between already available
24481 contents and zone contents and applying it to the current zone contents,
24482 @item @code{'difference-no-serial} for the same as @code{'difference}, but
24483 ignoring the SOA serial in the zone file, while the server takes care of it
24485 @item @code{'whole} for loading zone contents from the zone file.
24488 @item @code{journal-content} (default: @code{#f})
24489 The way the journal is used to store zone and its changes. Possible values
24490 are @code{'none} to not use it at all, @code{'changes} to store changes and
24491 @code{'all} to store contents. @code{#f} does not set this option, so the
24492 default value from Knot is used.
24494 @item @code{max-journal-usage} (default: @code{#f})
24495 The maximum size for the journal on disk. @code{#f} does not set this option,
24496 so the default value from Knot is used.
24498 @item @code{max-journal-depth} (default: @code{#f})
24499 The maximum size of the history. @code{#f} does not set this option, so the
24500 default value from Knot is used.
24502 @item @code{max-zone-size} (default: @code{#f})
24503 The maximum size of the zone file. This limit is enforced for incoming
24504 transfer and updates. @code{#f} does not set this option, so the default
24505 value from Knot is used.
24507 @item @code{dnssec-policy} (default: @code{#f})
24508 A reference to a @code{knot-policy-configuration} record, or the special
24509 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
24512 @item @code{serial-policy} (default: @code{'increment})
24513 A policy between @code{'increment} and @code{'unixtime}.
24518 @deftp {Data Type} knot-configuration
24519 Data type representing the Knot configuration.
24520 This type has the following parameters:
24523 @item @code{knot} (default: @code{knot})
24526 @item @code{run-directory} (default: @code{"/var/run/knot"})
24527 The run directory. This directory will be used for pid file and sockets.
24529 @item @code{includes} (default: @code{'()})
24530 A list of strings or file-like objects denoting other files that must be
24531 included at the top of the configuration file.
24533 @cindex secrets, Knot service
24534 This can be used to manage secrets out-of-band. For example, secret
24535 keys may be stored in an out-of-band file not managed by Guix, and
24536 thus not visible in @file{/gnu/store}---e.g., you could store secret
24537 key configuration in @file{/etc/knot/secrets.conf} and add this file
24538 to the @code{includes} list.
24540 One can generate a secret tsig key (for nsupdate and zone transfers with the
24541 keymgr command from the knot package. Note that the package is not automatically
24542 installed by the service. The following example shows how to generate a new
24546 keymgr -t mysecret > /etc/knot/secrets.conf
24547 chmod 600 /etc/knot/secrets.conf
24550 Also note that the generated key will be named @var{mysecret}, so it is the
24551 name that needs to be used in the @var{key} field of the
24552 @code{knot-acl-configuration} record and in other places that need to refer
24555 It can also be used to add configuration not supported by this interface.
24557 @item @code{listen-v4} (default: @code{"0.0.0.0"})
24558 An ip address on which to listen.
24560 @item @code{listen-v6} (default: @code{"::"})
24561 An ip address on which to listen.
24563 @item @code{listen-port} (default: @code{53})
24564 A port on which to listen.
24566 @item @code{keys} (default: @code{'()})
24567 The list of knot-key-configuration used by this configuration.
24569 @item @code{acls} (default: @code{'()})
24570 The list of knot-acl-configuration used by this configuration.
24572 @item @code{remotes} (default: @code{'()})
24573 The list of knot-remote-configuration used by this configuration.
24575 @item @code{zones} (default: @code{'()})
24576 The list of knot-zone-configuration used by this configuration.
24581 @subsubheading Knot Resolver Service
24583 @deffn {Scheme Variable} knot-resolver-service-type
24584 This is the type of the knot resolver service, whose value should be
24585 an @code{knot-resolver-configuration} object as in this example:
24588 (service knot-resolver-service-type
24589 (knot-resolver-configuration
24590 (kresd-config-file (plain-file "kresd.conf" "
24591 net.listen('192.168.0.1', 5353)
24592 user('knot-resolver', 'knot-resolver')
24593 modules = @{ 'hints > iterate', 'stats', 'predict' @}
24594 cache.size = 100 * MB
24598 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
24601 @deftp {Data Type} knot-resolver-configuration
24602 Data type representing the configuration of knot-resolver.
24605 @item @code{package} (default: @var{knot-resolver})
24606 Package object of the knot DNS resolver.
24608 @item @code{kresd-config-file} (default: %kresd.conf)
24609 File-like object of the kresd configuration file to use, by default it
24610 will listen on @code{127.0.0.1} and @code{::1}.
24612 @item @code{garbage-collection-interval} (default: 1000)
24613 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
24619 @subsubheading Dnsmasq Service
24621 @deffn {Scheme Variable} dnsmasq-service-type
24622 This is the type of the dnsmasq service, whose value should be an
24623 @code{dnsmasq-configuration} object as in this example:
24626 (service dnsmasq-service-type
24627 (dnsmasq-configuration
24629 (servers '("192.168.1.1"))))
24633 @deftp {Data Type} dnsmasq-configuration
24634 Data type representing the configuration of dnsmasq.
24637 @item @code{package} (default: @var{dnsmasq})
24638 Package object of the dnsmasq server.
24640 @item @code{no-hosts?} (default: @code{#f})
24641 When true, don't read the hostnames in /etc/hosts.
24643 @item @code{port} (default: @code{53})
24644 The port to listen on. Setting this to zero completely disables DNS
24645 responses, leaving only DHCP and/or TFTP functions.
24647 @item @code{local-service?} (default: @code{#t})
24648 Accept DNS queries only from hosts whose address is on a local subnet,
24649 ie a subnet for which an interface exists on the server.
24651 @item @code{listen-addresses} (default: @code{'()})
24652 Listen on the given IP addresses.
24654 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
24655 The file to read the IP address of the upstream nameservers from.
24657 @item @code{no-resolv?} (default: @code{#f})
24658 When true, don't read @var{resolv-file}.
24660 @item @code{servers} (default: @code{'()})
24661 Specify IP address of upstream servers directly.
24663 @item @code{addresses} (default: @code{'()})
24664 For each entry, specify an IP address to return for any host in the
24665 given domains. Queries in the domains are never forwarded and always
24666 replied to with the specified IP address.
24668 This is useful for redirecting hosts locally, for example:
24671 (service dnsmasq-service-type
24672 (dnsmasq-configuration
24674 '(; Redirect to a local web-server.
24675 "/example.org/127.0.0.1"
24676 ; Redirect subdomain to a specific IP.
24677 "/subdomain.example.org/192.168.1.42"))))
24680 Note that rules in @file{/etc/hosts} take precedence over this.
24682 @item @code{cache-size} (default: @code{150})
24683 Set the size of dnsmasq's cache. Setting the cache size to zero
24686 @item @code{negative-cache?} (default: @code{#t})
24687 When false, disable negative caching.
24689 @item @code{tftp-enable?} (default: @code{#f})
24690 Whether to enable the built-in TFTP server.
24692 @item @code{tftp-no-fail?} (default: @code{#f})
24693 If true, does not fail dnsmasq if the TFTP server could not start up.
24695 @item @code{tftp-single-port?} (default: @code{#f})
24696 Whether to use only one single port for TFTP.
24698 @item @code{tftp-secure?} (default: @code{#f})
24699 If true, only files owned by the user running the dnsmasq process are accessible.
24701 If dnsmasq is being run as root, different rules apply:
24702 @code{tftp-secure?} has no effect, but only files which have the
24703 world-readable bit set are accessible.
24705 @item @code{tftp-max} (default: @code{#f})
24706 If set, sets the maximal number of concurrent connections allowed.
24708 @item @code{tftp-mtu} (default: @code{#f})
24709 If set, sets the MTU for TFTP packets to that value.
24711 @item @code{tftp-no-blocksize?} (default: @code{#f})
24712 If true, stops the TFTP server from negotiating the blocksize with a client.
24714 @item @code{tftp-lowercase?} (default: @code{#f})
24715 Whether to convert all filenames in TFTP requests to lowercase.
24717 @item @code{tftp-port-range} (default: @code{#f})
24718 If set, fixes the dynamical ports (one per client) to the given range
24719 (@code{"<start>,<end>"}).
24721 @item @code{tftp-root} (default: @code{/var/empty,lo})
24722 Look for files to transfer using TFTP relative to the given directory.
24723 When this is set, TFTP paths which include ".." are rejected, to stop clients
24724 getting outside the specified root. Absolute paths (starting with /) are
24725 allowed, but they must be within the tftp-root. If the optional interface
24726 argument is given, the directory is only used for TFTP requests via that
24729 @item @code{tftp-unique-root} (default: @code{#f})
24730 If set, add the IP or hardware address of the TFTP client as a path component
24731 on the end of the TFTP-root. Only valid if a TFTP root is set and the
24732 directory exists. Defaults to adding IP address (in standard dotted-quad
24735 For instance, if --tftp-root is "/tftp" and client 1.2.3.4 requests file
24736 "myfile" then the effective path will be "/tftp/1.2.3.4/myfile" if
24737 /tftp/1.2.3.4 exists or /tftp/myfile otherwise. When "=mac" is specified
24738 it will append the MAC address instead, using lowercase zero padded digits
24739 separated by dashes, e.g.: 01-02-03-04-aa-bb Note that resolving MAC
24740 addresses is only possible if the client is in the local network or obtained
24741 a DHCP lease from dnsmasq.
24746 @subsubheading ddclient Service
24749 The ddclient service described below runs the ddclient daemon, which takes
24750 care of automatically updating DNS entries for service providers such as
24751 @uref{https://dyn.com/dns/, Dyn}.
24753 The following example show instantiates the service with its default
24757 (service ddclient-service-type)
24760 Note that ddclient needs to access credentials that are stored in a
24761 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
24762 @code{secret-file} below). You are expected to create this file manually, in
24763 an ``out-of-band'' fashion (you @emph{could} make this file part of the
24764 service configuration, for instance by using @code{plain-file}, but it will be
24765 world-readable @i{via} @file{/gnu/store}). See the examples in the
24766 @file{share/ddclient} directory of the @code{ddclient} package.
24768 @c %start of fragment
24770 Available @code{ddclient-configuration} fields are:
24772 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
24773 The ddclient package.
24777 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
24778 The period after which ddclient will retry to check IP and domain name.
24780 Defaults to @samp{300}.
24784 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
24785 Use syslog for the output.
24787 Defaults to @samp{#t}.
24791 @deftypevr {@code{ddclient-configuration} parameter} string mail
24794 Defaults to @samp{"root"}.
24798 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
24799 Mail failed update to user.
24801 Defaults to @samp{"root"}.
24805 @deftypevr {@code{ddclient-configuration} parameter} string pid
24806 The ddclient PID file.
24808 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
24812 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
24813 Enable SSL support.
24815 Defaults to @samp{#t}.
24819 @deftypevr {@code{ddclient-configuration} parameter} string user
24820 Specifies the user name or ID that is used when running ddclient
24823 Defaults to @samp{"ddclient"}.
24827 @deftypevr {@code{ddclient-configuration} parameter} string group
24828 Group of the user who will run the ddclient program.
24830 Defaults to @samp{"ddclient"}.
24834 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
24835 Secret file which will be appended to @file{ddclient.conf} file. This
24836 file contains credentials for use by ddclient. You are expected to
24837 create it manually.
24839 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
24843 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
24844 Extra options will be appended to @file{ddclient.conf} file.
24846 Defaults to @samp{()}.
24851 @c %end of fragment
24855 @subsection VPN Services
24856 @cindex VPN (virtual private network)
24857 @cindex virtual private network (VPN)
24859 The @code{(gnu services vpn)} module provides services related to
24860 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
24861 your machine to connect to a VPN, and a @emph{server} service for your machine
24862 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
24864 @deffn {Scheme Procedure} openvpn-client-service @
24865 [#:config (openvpn-client-configuration)]
24867 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
24870 @deffn {Scheme Procedure} openvpn-server-service @
24871 [#:config (openvpn-server-configuration)]
24873 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
24875 Both can be run simultaneously.
24878 @c %automatically generated documentation
24880 Available @code{openvpn-client-configuration} fields are:
24882 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
24883 The OpenVPN package.
24887 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
24888 The OpenVPN pid file.
24890 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
24894 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
24895 The protocol (UDP or TCP) used to open a channel between clients and
24898 Defaults to @samp{udp}.
24902 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
24903 The device type used to represent the VPN connection.
24905 Defaults to @samp{tun}.
24909 If you do not have some of these files (eg.@: you use a username and
24910 password), you can disable any of the following three fields by setting
24911 it to @code{'disabled}.
24913 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string ca
24914 The certificate authority to check connections against.
24916 Defaults to @samp{"/etc/openvpn/ca.crt"}.
24920 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string cert
24921 The certificate of the machine the daemon is running on. It should be
24922 signed by the authority given in @code{ca}.
24924 Defaults to @samp{"/etc/openvpn/client.crt"}.
24928 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string key
24929 The key of the machine the daemon is running on. It must be the key whose
24930 certificate is @code{cert}.
24932 Defaults to @samp{"/etc/openvpn/client.key"}.
24936 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
24937 Whether to use the lzo compression algorithm.
24939 Defaults to @samp{#t}.
24943 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
24944 Don't re-read key files across SIGUSR1 or --ping-restart.
24946 Defaults to @samp{#t}.
24950 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
24951 Don't close and reopen TUN/TAP device or run up/down scripts across
24952 SIGUSR1 or --ping-restart restarts.
24954 Defaults to @samp{#t}.
24958 @deftypevr {@code{openvpn-client-configuration} parameter} boolean fast-io?
24959 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
24960 poll/epoll/select prior to the write operation.
24962 Defaults to @samp{#f}.
24965 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
24968 Defaults to @samp{3}.
24972 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
24973 Add an additional layer of HMAC authentication on top of the TLS control
24974 channel to protect against DoS attacks.
24976 Defaults to @samp{#f}.
24980 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string auth-user-pass
24981 Authenticate with server using username/password. The option is a file
24982 containing username/password on 2 lines. Do not use a file-like object as it
24983 would be added to the store and readable by any user.
24985 Defaults to @samp{'disabled}.
24988 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
24989 Whether to check the server certificate has server usage extension.
24991 Defaults to @samp{#t}.
24995 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
24996 Bind to a specific local port number.
24998 Defaults to @samp{#f}.
25002 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
25003 Retry resolving server address.
25005 Defaults to @samp{#t}.
25009 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
25010 A list of remote servers to connect to.
25012 Defaults to @samp{()}.
25014 Available @code{openvpn-remote-configuration} fields are:
25016 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
25019 Defaults to @samp{"my-server"}.
25023 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
25024 Port number the server listens to.
25026 Defaults to @samp{1194}.
25031 @c %end of automatic openvpn-client documentation
25033 @c %automatically generated documentation
25035 Available @code{openvpn-server-configuration} fields are:
25037 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
25038 The OpenVPN package.
25042 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
25043 The OpenVPN pid file.
25045 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
25049 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
25050 The protocol (UDP or TCP) used to open a channel between clients and
25053 Defaults to @samp{udp}.
25057 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
25058 The device type used to represent the VPN connection.
25060 Defaults to @samp{tun}.
25064 If you do not have some of these files (eg.@: you use a username and
25065 password), you can disable any of the following three fields by setting
25066 it to @code{'disabled}.
25068 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string ca
25069 The certificate authority to check connections against.
25071 Defaults to @samp{"/etc/openvpn/ca.crt"}.
25075 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string cert
25076 The certificate of the machine the daemon is running on. It should be
25077 signed by the authority given in @code{ca}.
25079 Defaults to @samp{"/etc/openvpn/client.crt"}.
25083 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string key
25084 The key of the machine the daemon is running on. It must be the key whose
25085 certificate is @code{cert}.
25087 Defaults to @samp{"/etc/openvpn/client.key"}.
25091 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
25092 Whether to use the lzo compression algorithm.
25094 Defaults to @samp{#t}.
25098 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
25099 Don't re-read key files across SIGUSR1 or --ping-restart.
25101 Defaults to @samp{#t}.
25105 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
25106 Don't close and reopen TUN/TAP device or run up/down scripts across
25107 SIGUSR1 or --ping-restart restarts.
25109 Defaults to @samp{#t}.
25113 @deftypevr {@code{openvpn-server-configuration} parameter} boolean fast-io?
25114 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
25115 poll/epoll/select prior to the write operation.
25117 Defaults to @samp{#f}.
25120 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
25123 Defaults to @samp{3}.
25127 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
25128 Add an additional layer of HMAC authentication on top of the TLS control
25129 channel to protect against DoS attacks.
25131 Defaults to @samp{#f}.
25135 @deftypevr {@code{openvpn-server-configuration} parameter} number port
25136 Specifies the port number on which the server listens.
25138 Defaults to @samp{1194}.
25142 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
25143 An ip and mask specifying the subnet inside the virtual network.
25145 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
25149 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
25150 A CIDR notation specifying the IPv6 subnet inside the virtual network.
25152 Defaults to @samp{#f}.
25156 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
25157 The Diffie-Hellman parameters file.
25159 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
25163 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
25164 The file that records client IPs.
25166 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
25170 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
25171 When true, the server will act as a gateway for its clients.
25173 Defaults to @samp{#f}.
25177 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
25178 When true, clients are allowed to talk to each other inside the VPN.
25180 Defaults to @samp{#f}.
25184 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
25185 Causes ping-like messages to be sent back and forth over the link so
25186 that each side knows when the other side has gone down. @code{keepalive}
25187 requires a pair. The first element is the period of the ping sending,
25188 and the second element is the timeout before considering the other side
25193 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
25194 The maximum number of clients.
25196 Defaults to @samp{100}.
25200 @deftypevr {@code{openvpn-server-configuration} parameter} string status
25201 The status file. This file shows a small report on current connection.
25202 It is truncated and rewritten every minute.
25204 Defaults to @samp{"/var/run/openvpn/status"}.
25208 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
25209 The list of configuration for some clients.
25211 Defaults to @samp{()}.
25213 Available @code{openvpn-ccd-configuration} fields are:
25215 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
25218 Defaults to @samp{"client"}.
25222 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
25225 Defaults to @samp{#f}.
25229 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
25232 Defaults to @samp{#f}.
25239 @c %end of automatic openvpn-server documentation
25242 @node Network File System
25243 @subsection Network File System
25246 The @code{(gnu services nfs)} module provides the following services,
25247 which are most commonly used in relation to mounting or exporting
25248 directory trees as @dfn{network file systems} (NFS).
25250 While it is possible to use the individual components that together make
25251 up a Network File System service, we recommended to configure an NFS
25252 server with the @code{nfs-service-type}.
25254 @subsubheading NFS Service
25255 @cindex NFS, server
25257 The NFS service takes care of setting up all NFS component services,
25258 kernel configuration file systems, and installs configuration files in
25259 the locations that NFS expects.
25261 @defvr {Scheme Variable} nfs-service-type
25262 A service type for a complete NFS server.
25265 @deftp {Data Type} nfs-configuration
25266 This data type represents the configuration of the NFS service and all
25269 It has the following parameters:
25271 @item @code{nfs-utils} (default: @code{nfs-utils})
25272 The nfs-utils package to use.
25274 @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
25275 If a list of string values is provided, the @command{rpc.nfsd} daemon
25276 will be limited to supporting the given versions of the NFS protocol.
25278 @item @code{exports} (default: @code{'()})
25279 This is a list of directories the NFS server should export. Each entry
25280 is a list consisting of two elements: a directory name and a string
25281 containing all options. This is an example in which the directory
25282 @file{/export} is served to all NFS clients as a read-only share:
25288 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
25291 @item @code{rpcmountd-port} (default: @code{#f})
25292 The network port that the @command{rpc.mountd} daemon should use.
25294 @item @code{rpcstatd-port} (default: @code{#f})
25295 The network port that the @command{rpc.statd} daemon should use.
25297 @item @code{rpcbind} (default: @code{rpcbind})
25298 The rpcbind package to use.
25300 @item @code{idmap-domain} (default: @code{"localdomain"})
25301 The local NFSv4 domain name.
25303 @item @code{nfsd-port} (default: @code{2049})
25304 The network port that the @command{nfsd} daemon should use.
25306 @item @code{nfsd-threads} (default: @code{8})
25307 The number of threads used by the @command{nfsd} daemon.
25309 @item @code{nfsd-tcp?} (default: @code{#t})
25310 Whether the @command{nfsd} daemon should listen on a TCP socket.
25312 @item @code{nfsd-udp?} (default: @code{#f})
25313 Whether the @command{nfsd} daemon should listen on a UDP socket.
25315 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
25316 The directory where the pipefs file system is mounted.
25318 @item @code{debug} (default: @code{'()"})
25319 A list of subsystems for which debugging output should be enabled. This
25320 is a list of symbols. Any of these symbols are valid: @code{nfsd},
25321 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
25325 If you don't need a complete NFS service or prefer to build it yourself
25326 you can use the individual component services that are documented below.
25328 @subsubheading RPC Bind Service
25331 The RPC Bind service provides a facility to map program numbers into
25332 universal addresses.
25333 Many NFS related services use this facility. Hence it is automatically
25334 started when a dependent service starts.
25336 @defvr {Scheme Variable} rpcbind-service-type
25337 A service type for the RPC portmapper daemon.
25341 @deftp {Data Type} rpcbind-configuration
25342 Data type representing the configuration of the RPC Bind Service.
25343 This type has the following parameters:
25345 @item @code{rpcbind} (default: @code{rpcbind})
25346 The rpcbind package to use.
25348 @item @code{warm-start?} (default: @code{#t})
25349 If this parameter is @code{#t}, then the daemon will read a
25350 state file on startup thus reloading state information saved by a previous
25356 @subsubheading Pipefs Pseudo File System
25360 The pipefs file system is used to transfer NFS related data
25361 between the kernel and user space programs.
25363 @defvr {Scheme Variable} pipefs-service-type
25364 A service type for the pipefs pseudo file system.
25367 @deftp {Data Type} pipefs-configuration
25368 Data type representing the configuration of the pipefs pseudo file system service.
25369 This type has the following parameters:
25371 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
25372 The directory to which the file system is to be attached.
25377 @subsubheading GSS Daemon Service
25380 @cindex global security system
25382 The @dfn{global security system} (GSS) daemon provides strong security for RPC
25384 Before exchanging RPC requests an RPC client must establish a security
25385 context. Typically this is done using the Kerberos command @command{kinit}
25386 or automatically at login time using PAM services (@pxref{Kerberos Services}).
25388 @defvr {Scheme Variable} gss-service-type
25389 A service type for the Global Security System (GSS) daemon.
25392 @deftp {Data Type} gss-configuration
25393 Data type representing the configuration of the GSS daemon service.
25394 This type has the following parameters:
25396 @item @code{nfs-utils} (default: @code{nfs-utils})
25397 The package in which the @command{rpc.gssd} command is to be found.
25399 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
25400 The directory where the pipefs file system is mounted.
25406 @subsubheading IDMAP Daemon Service
25408 @cindex name mapper
25410 The idmap daemon service provides mapping between user IDs and user names.
25411 Typically it is required in order to access file systems mounted via NFSv4.
25413 @defvr {Scheme Variable} idmap-service-type
25414 A service type for the Identity Mapper (IDMAP) daemon.
25417 @deftp {Data Type} idmap-configuration
25418 Data type representing the configuration of the IDMAP daemon service.
25419 This type has the following parameters:
25421 @item @code{nfs-utils} (default: @code{nfs-utils})
25422 The package in which the @command{rpc.idmapd} command is to be found.
25424 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
25425 The directory where the pipefs file system is mounted.
25427 @item @code{domain} (default: @code{#f})
25428 The local NFSv4 domain name.
25429 This must be a string or @code{#f}.
25430 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
25432 @item @code{verbosity} (default: @code{0})
25433 The verbosity level of the daemon.
25438 @node Continuous Integration
25439 @subsection Continuous Integration
25441 @cindex continuous integration
25442 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
25443 continuous integration tool for Guix. It can be used both for development and
25444 for providing substitutes to others (@pxref{Substitutes}).
25446 The @code{(gnu services cuirass)} module provides the following service.
25448 @defvr {Scheme Procedure} cuirass-service-type
25449 The type of the Cuirass service. Its value must be a
25450 @code{cuirass-configuration} object, as described below.
25453 To add build jobs, you have to set the @code{specifications} field of the
25454 configuration. Here is an example of a service that polls the Guix repository
25455 and builds the packages from a manifest. Some of the packages are defined in
25456 the @code{"custom-packages"} input, which is the equivalent of
25457 @env{GUIX_PACKAGE_PATH}.
25460 (define %cuirass-specs
25462 '((#:name . "my-manifest")
25463 (#:load-path-inputs . ("guix"))
25464 (#:package-path-inputs . ("custom-packages"))
25465 (#:proc-input . "guix")
25466 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
25467 (#:proc . cuirass-jobs)
25468 (#:proc-args . ((subset . "manifests")
25469 (systems . ("x86_64-linux"))
25470 (manifests . (("config" . "guix/manifest.scm")))))
25471 (#:inputs . (((#:name . "guix")
25472 (#:url . "git://git.savannah.gnu.org/guix.git")
25473 (#:load-path . ".")
25474 (#:branch . "master")
25475 (#:no-compile? . #t))
25476 ((#:name . "config")
25477 (#:url . "https://git.example.org/config.git")
25478 (#:load-path . ".")
25479 (#:branch . "master")
25480 (#:no-compile? . #t))
25481 ((#:name . "custom-packages")
25482 (#:url . "https://git.example.org/custom-packages.git")
25483 (#:load-path . ".")
25484 (#:branch . "master")
25485 (#:no-compile? . #t)))))))
25487 (service cuirass-service-type
25488 (cuirass-configuration
25489 (specifications %cuirass-specs)))
25492 While information related to build jobs is located directly in the
25493 specifications, global settings for the @command{cuirass} process are
25494 accessible in other @code{cuirass-configuration} fields.
25496 @deftp {Data Type} cuirass-configuration
25497 Data type representing the configuration of Cuirass.
25500 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
25501 Location of the log file.
25503 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
25504 Location of the log file used by the web interface.
25506 @item @code{queries-log-file} (default: @code{#f})
25507 Location of the SQL queries log file. By default, SQL queries logging is
25510 @item @code{web-queries-log-file} (default: @code{#f})
25511 Location of the web SQL queries log file. By default, web SQL queries
25512 logging is disabled.
25514 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
25515 Location of the repository cache.
25517 @item @code{user} (default: @code{"cuirass"})
25518 Owner of the @code{cuirass} process.
25520 @item @code{group} (default: @code{"cuirass"})
25521 Owner's group of the @code{cuirass} process.
25523 @item @code{interval} (default: @code{60})
25524 Number of seconds between the poll of the repositories followed by the
25527 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
25528 Location of sqlite database which contains the build results and previously
25529 added specifications.
25531 @item @code{ttl} (default: @code{(* 30 24 3600)})
25532 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
25533 are registered for build results. This means that build results are protected
25534 from garbage collection for at least @var{ttl} seconds.
25536 @item @code{port} (default: @code{8081})
25537 Port number used by the HTTP server.
25539 @item @code{host} (default: @code{"localhost"})
25540 Listen on the network interface for @var{host}. The default is to
25541 accept connections from localhost.
25543 @item @code{specifications} (default: @code{#~'()})
25544 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
25545 where a specification is an association list
25546 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
25547 keys are keywords (@code{#:keyword-example}) as shown in the example
25550 @item @code{use-substitutes?} (default: @code{#f})
25551 This allows using substitutes to avoid building every dependencies of a job
25554 @item @code{one-shot?} (default: @code{#f})
25555 Only evaluate specifications and build derivations once.
25557 @item @code{fallback?} (default: @code{#f})
25558 When substituting a pre-built binary fails, fall back to building
25561 @item @code{extra-options} (default: @code{'()})
25562 Extra options to pass when running the Cuirass processes.
25564 @item @code{cuirass} (default: @code{cuirass})
25565 The Cuirass package to use.
25569 @node Power Management Services
25570 @subsection Power Management Services
25573 @cindex power management with TLP
25574 @subsubheading TLP daemon
25576 The @code{(gnu services pm)} module provides a Guix service definition
25577 for the Linux power management tool TLP.
25579 TLP enables various powersaving modes in userspace and kernel.
25580 Contrary to @code{upower-service}, it is not a passive,
25581 monitoring tool, as it will apply custom settings each time a new power
25582 source is detected. More information can be found at
25583 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
25585 @deffn {Scheme Variable} tlp-service-type
25586 The service type for the TLP tool. The default settings are optimised
25587 for battery life on most systems, but you can tweak them to your heart's
25588 content by adding a valid @code{tlp-configuration}:
25590 (service tlp-service-type
25592 (cpu-scaling-governor-on-ac (list "performance"))
25593 (sched-powersave-on-bat? #t)))
25597 Each parameter definition is preceded by its type; for example,
25598 @samp{boolean foo} indicates that the @code{foo} parameter
25599 should be specified as a boolean. Types starting with
25600 @code{maybe-} denote parameters that won't show up in TLP config file
25601 when their value is @code{'disabled}.
25603 @c The following documentation was initially generated by
25604 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
25605 @c documentation is better, so we shouldn't hesitate to edit below as
25606 @c needed. However if the change you want to make to this documentation
25607 @c can be done in an automated way, it's probably easier to change
25608 @c (generate-documentation) than to make it below and have to deal with
25609 @c the churn as TLP updates.
25611 Available @code{tlp-configuration} fields are:
25613 @deftypevr {@code{tlp-configuration} parameter} package tlp
25618 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
25619 Set to true if you wish to enable TLP.
25621 Defaults to @samp{#t}.
25625 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
25626 Default mode when no power supply can be detected. Alternatives are AC
25629 Defaults to @samp{"AC"}.
25633 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
25634 Number of seconds Linux kernel has to wait after the disk goes idle,
25635 before syncing on AC.
25637 Defaults to @samp{0}.
25641 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
25642 Same as @code{disk-idle-ac} but on BAT mode.
25644 Defaults to @samp{2}.
25648 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
25649 Dirty pages flushing periodicity, expressed in seconds.
25651 Defaults to @samp{15}.
25655 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
25656 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
25658 Defaults to @samp{60}.
25662 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
25663 CPU frequency scaling governor on AC mode. With intel_pstate driver,
25664 alternatives are powersave and performance. With acpi-cpufreq driver,
25665 alternatives are ondemand, powersave, performance and conservative.
25667 Defaults to @samp{disabled}.
25671 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
25672 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
25674 Defaults to @samp{disabled}.
25678 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
25679 Set the min available frequency for the scaling governor on AC.
25681 Defaults to @samp{disabled}.
25685 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
25686 Set the max available frequency for the scaling governor on AC.
25688 Defaults to @samp{disabled}.
25692 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
25693 Set the min available frequency for the scaling governor on BAT.
25695 Defaults to @samp{disabled}.
25699 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
25700 Set the max available frequency for the scaling governor on BAT.
25702 Defaults to @samp{disabled}.
25706 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
25707 Limit the min P-state to control the power dissipation of the CPU, in AC
25708 mode. Values are stated as a percentage of the available performance.
25710 Defaults to @samp{disabled}.
25714 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
25715 Limit the max P-state to control the power dissipation of the CPU, in AC
25716 mode. Values are stated as a percentage of the available performance.
25718 Defaults to @samp{disabled}.
25722 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
25723 Same as @code{cpu-min-perf-on-ac} on BAT mode.
25725 Defaults to @samp{disabled}.
25729 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
25730 Same as @code{cpu-max-perf-on-ac} on BAT mode.
25732 Defaults to @samp{disabled}.
25736 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
25737 Enable CPU turbo boost feature on AC mode.
25739 Defaults to @samp{disabled}.
25743 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
25744 Same as @code{cpu-boost-on-ac?} on BAT mode.
25746 Defaults to @samp{disabled}.
25750 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
25751 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
25752 used under light load conditions.
25754 Defaults to @samp{#f}.
25758 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
25759 Same as @code{sched-powersave-on-ac?} but on BAT mode.
25761 Defaults to @samp{#t}.
25765 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
25766 Enable Linux kernel NMI watchdog.
25768 Defaults to @samp{#f}.
25772 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
25773 For Linux kernels with PHC patch applied, change CPU voltages. An
25774 example value would be @samp{"F:V F:V F:V F:V"}.
25776 Defaults to @samp{disabled}.
25780 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
25781 Set CPU performance versus energy saving policy on AC. Alternatives are
25782 performance, normal, powersave.
25784 Defaults to @samp{"performance"}.
25788 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
25789 Same as @code{energy-perf-policy-ac} but on BAT mode.
25791 Defaults to @samp{"powersave"}.
25795 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
25800 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
25801 Hard disk advanced power management level.
25805 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
25806 Same as @code{disk-apm-bat} but on BAT mode.
25810 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
25811 Hard disk spin down timeout. One value has to be specified for each
25812 declared hard disk.
25814 Defaults to @samp{disabled}.
25818 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
25819 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
25821 Defaults to @samp{disabled}.
25825 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
25826 Select IO scheduler for disk devices. One value has to be specified for
25827 each declared hard disk. Example alternatives are cfq, deadline and
25830 Defaults to @samp{disabled}.
25834 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
25835 SATA aggressive link power management (ALPM) level. Alternatives are
25836 min_power, medium_power, max_performance.
25838 Defaults to @samp{"max_performance"}.
25842 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
25843 Same as @code{sata-linkpwr-ac} but on BAT mode.
25845 Defaults to @samp{"min_power"}.
25849 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
25850 Exclude specified SATA host devices for link power management.
25852 Defaults to @samp{disabled}.
25856 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
25857 Enable Runtime Power Management for AHCI controller and disks on AC
25860 Defaults to @samp{disabled}.
25864 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
25865 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
25867 Defaults to @samp{disabled}.
25871 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
25872 Seconds of inactivity before disk is suspended.
25874 Defaults to @samp{15}.
25878 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
25879 PCI Express Active State Power Management level. Alternatives are
25880 default, performance, powersave.
25882 Defaults to @samp{"performance"}.
25886 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
25887 Same as @code{pcie-aspm-ac} but on BAT mode.
25889 Defaults to @samp{"powersave"}.
25893 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
25894 Radeon graphics clock speed level. Alternatives are low, mid, high,
25897 Defaults to @samp{"high"}.
25901 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
25902 Same as @code{radeon-power-ac} but on BAT mode.
25904 Defaults to @samp{"low"}.
25908 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
25909 Radeon dynamic power management method (DPM). Alternatives are battery,
25912 Defaults to @samp{"performance"}.
25916 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
25917 Same as @code{radeon-dpm-state-ac} but on BAT mode.
25919 Defaults to @samp{"battery"}.
25923 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
25924 Radeon DPM performance level. Alternatives are auto, low, high.
25926 Defaults to @samp{"auto"}.
25930 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
25931 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
25933 Defaults to @samp{"auto"}.
25937 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
25938 Wifi power saving mode.
25940 Defaults to @samp{#f}.
25944 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
25945 Same as @code{wifi-power-ac?} but on BAT mode.
25947 Defaults to @samp{#t}.
25951 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
25952 Disable wake on LAN.
25954 Defaults to @samp{#t}.
25958 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
25959 Timeout duration in seconds before activating audio power saving on
25960 Intel HDA and AC97 devices. A value of 0 disables power saving.
25962 Defaults to @samp{0}.
25966 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
25967 Same as @code{sound-powersave-ac} but on BAT mode.
25969 Defaults to @samp{1}.
25973 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
25974 Disable controller in powersaving mode on Intel HDA devices.
25976 Defaults to @samp{#t}.
25980 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
25981 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
25982 powered on again by releasing (and reinserting) the eject lever or by
25983 pressing the disc eject button on newer models.
25985 Defaults to @samp{#f}.
25989 @deftypevr {@code{tlp-configuration} parameter} string bay-device
25990 Name of the optical drive device to power off.
25992 Defaults to @samp{"sr0"}.
25996 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
25997 Runtime Power Management for PCI(e) bus devices. Alternatives are on
26000 Defaults to @samp{"on"}.
26004 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
26005 Same as @code{runtime-pm-ac} but on BAT mode.
26007 Defaults to @samp{"auto"}.
26011 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
26012 Runtime Power Management for all PCI(e) bus devices, except blacklisted
26015 Defaults to @samp{#t}.
26019 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
26020 Exclude specified PCI(e) device addresses from Runtime Power Management.
26022 Defaults to @samp{disabled}.
26026 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
26027 Exclude PCI(e) devices assigned to the specified drivers from Runtime
26032 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
26033 Enable USB autosuspend feature.
26035 Defaults to @samp{#t}.
26039 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
26040 Exclude specified devices from USB autosuspend.
26042 Defaults to @samp{disabled}.
26046 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
26047 Exclude WWAN devices from USB autosuspend.
26049 Defaults to @samp{#t}.
26053 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
26054 Include specified devices into USB autosuspend, even if they are already
26055 excluded by the driver or via @code{usb-blacklist-wwan?}.
26057 Defaults to @samp{disabled}.
26061 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
26062 Enable USB autosuspend before shutdown.
26064 Defaults to @samp{disabled}.
26068 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
26069 Restore radio device state (bluetooth, wifi, wwan) from previous
26070 shutdown on system startup.
26072 Defaults to @samp{#f}.
26077 @cindex CPU frequency scaling with thermald
26078 @subsubheading Thermald daemon
26080 The @code{(gnu services pm)} module provides an interface to
26081 thermald, a CPU frequency scaling service which helps prevent overheating.
26083 @defvr {Scheme Variable} thermald-service-type
26084 This is the service type for
26085 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
26086 Thermal Daemon, which is responsible for controlling the thermal state
26087 of processors and preventing overheating.
26090 @deftp {Data Type} thermald-configuration
26091 Data type representing the configuration of @code{thermald-service-type}.
26094 @item @code{ignore-cpuid-check?} (default: @code{#f})
26095 Ignore cpuid check for supported CPU models.
26097 @item @code{thermald} (default: @var{thermald})
26098 Package object of thermald.
26103 @node Audio Services
26104 @subsection Audio Services
26106 The @code{(gnu services audio)} module provides a service to start MPD
26107 (the Music Player Daemon).
26110 @subsubheading Music Player Daemon
26112 The Music Player Daemon (MPD) is a service that can play music while
26113 being controlled from the local machine or over the network by a variety
26116 The following example shows how one might run @code{mpd} as user
26117 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
26120 (service mpd-service-type
26126 @defvr {Scheme Variable} mpd-service-type
26127 The service type for @command{mpd}
26130 @deftp {Data Type} mpd-configuration
26131 Data type representing the configuration of @command{mpd}.
26134 @item @code{user} (default: @code{"mpd"})
26135 The user to run mpd as.
26137 @item @code{music-dir} (default: @code{"~/Music"})
26138 The directory to scan for music files.
26140 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
26141 The directory to store playlists.
26143 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
26144 The location of the music database.
26146 @item @code{state-file} (default: @code{"~/.mpd/state"})
26147 The location of the file that stores current MPD's state.
26149 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
26150 The location of the sticker database.
26152 @item @code{port} (default: @code{"6600"})
26153 The port to run mpd on.
26155 @item @code{address} (default: @code{"any"})
26156 The address that mpd will bind to. To use a Unix domain socket,
26157 an absolute path can be specified here.
26159 @item @code{outputs} (default: @code{"(list (mpd-output))"})
26160 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
26165 @deftp {Data Type} mpd-output
26166 Data type representing an @command{mpd} audio output.
26169 @item @code{name} (default: @code{"MPD"})
26170 The name of the audio output.
26172 @item @code{type} (default: @code{"pulse"})
26173 The type of audio output.
26175 @item @code{enabled?} (default: @code{#t})
26176 Specifies whether this audio output is enabled when MPD is started. By
26177 default, all audio outputs are enabled. This is just the default
26178 setting when there is no state file; with a state file, the previous
26181 @item @code{tags?} (default: @code{#t})
26182 If set to @code{#f}, then MPD will not send tags to this output. This
26183 is only useful for output plugins that can receive tags, for example the
26184 @code{httpd} output plugin.
26186 @item @code{always-on?} (default: @code{#f})
26187 If set to @code{#t}, then MPD attempts to keep this audio output always
26188 open. This may be useful for streaming servers, when you don’t want to
26189 disconnect all listeners even when playback is accidentally stopped.
26191 @item @code{mixer-type}
26192 This field accepts a symbol that specifies which mixer should be used
26193 for this audio output: the @code{hardware} mixer, the @code{software}
26194 mixer, the @code{null} mixer (allows setting the volume, but with no
26195 effect; this can be used as a trick to implement an external mixer
26196 External Mixer) or no mixer (@code{none}).
26198 @item @code{extra-options} (default: @code{'()})
26199 An association list of option symbols to string values to be appended to
26200 the audio output configuration.
26205 The following example shows a configuration of @code{mpd} that provides
26206 an HTTP audio streaming output.
26209 (service mpd-service-type
26217 `((encoder . "vorbis")
26218 (port . "8080"))))))))
26222 @node Virtualization Services
26223 @subsection Virtualization Services
26225 The @code{(gnu services virtualization)} module provides services for
26226 the libvirt and virtlog daemons, as well as other virtualization-related
26229 @subsubheading Libvirt daemon
26231 @code{libvirtd} is the server side daemon component of the libvirt
26232 virtualization management system. This daemon runs on host servers
26233 and performs required management tasks for virtualized guests.
26235 @deffn {Scheme Variable} libvirt-service-type
26236 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
26237 Its value must be a @code{libvirt-configuration}.
26240 (service libvirt-service-type
26241 (libvirt-configuration
26242 (unix-sock-group "libvirt")
26243 (tls-port "16555")))
26247 @c Auto-generated with (generate-libvirt-documentation)
26248 Available @code{libvirt-configuration} fields are:
26250 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
26255 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
26256 Flag listening for secure TLS connections on the public TCP/IP port.
26257 You must set @code{listen} for this to have any effect.
26259 It is necessary to setup a CA and issue server certificates before using
26262 Defaults to @samp{#t}.
26266 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
26267 Listen for unencrypted TCP connections on the public TCP/IP port. You must
26268 set @code{listen} for this to have any effect.
26270 Using the TCP socket requires SASL authentication by default. Only SASL
26271 mechanisms which support data encryption are allowed. This is
26272 DIGEST_MD5 and GSSAPI (Kerberos5).
26274 Defaults to @samp{#f}.
26278 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
26279 Port for accepting secure TLS connections. This can be a port number,
26282 Defaults to @samp{"16514"}.
26286 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
26287 Port for accepting insecure TCP connections. This can be a port number,
26290 Defaults to @samp{"16509"}.
26294 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
26295 IP address or hostname used for client connections.
26297 Defaults to @samp{"0.0.0.0"}.
26301 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
26302 Flag toggling mDNS advertisement of the libvirt service.
26304 Alternatively can disable for all services on a host by stopping the
26307 Defaults to @samp{#f}.
26311 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
26312 Default mDNS advertisement name. This must be unique on the immediate
26315 Defaults to @samp{"Virtualization Host <hostname>"}.
26319 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
26320 UNIX domain socket group ownership. This can be used to allow a
26321 'trusted' set of users access to management capabilities without
26324 Defaults to @samp{"root"}.
26328 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
26329 UNIX socket permissions for the R/O socket. This is used for monitoring
26332 Defaults to @samp{"0777"}.
26336 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
26337 UNIX socket permissions for the R/W socket. Default allows only root.
26338 If PolicyKit is enabled on the socket, the default will change to allow
26339 everyone (eg, 0777)
26341 Defaults to @samp{"0770"}.
26345 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
26346 UNIX socket permissions for the admin socket. Default allows only owner
26347 (root), do not change it unless you are sure to whom you are exposing
26350 Defaults to @samp{"0777"}.
26354 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
26355 The directory in which sockets will be found/created.
26357 Defaults to @samp{"/var/run/libvirt"}.
26361 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
26362 Authentication scheme for UNIX read-only sockets. By default socket
26363 permissions allow anyone to connect
26365 Defaults to @samp{"polkit"}.
26369 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
26370 Authentication scheme for UNIX read-write sockets. By default socket
26371 permissions only allow root. If PolicyKit support was compiled into
26372 libvirt, the default will be to use 'polkit' auth.
26374 Defaults to @samp{"polkit"}.
26378 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
26379 Authentication scheme for TCP sockets. If you don't enable SASL, then
26380 all TCP traffic is cleartext. Don't do this outside of a dev/test
26383 Defaults to @samp{"sasl"}.
26387 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
26388 Authentication scheme for TLS sockets. TLS sockets already have
26389 encryption provided by the TLS layer, and limited authentication is done
26392 It is possible to make use of any SASL authentication mechanism as well,
26393 by using 'sasl' for this option
26395 Defaults to @samp{"none"}.
26399 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
26400 API access control scheme.
26402 By default an authenticated user is allowed access to all APIs. Access
26403 drivers can place restrictions on this.
26405 Defaults to @samp{()}.
26409 @deftypevr {@code{libvirt-configuration} parameter} string key-file
26410 Server key file path. If set to an empty string, then no private key is
26413 Defaults to @samp{""}.
26417 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
26418 Server key file path. If set to an empty string, then no certificate is
26421 Defaults to @samp{""}.
26425 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
26426 Server key file path. If set to an empty string, then no CA certificate
26429 Defaults to @samp{""}.
26433 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
26434 Certificate revocation list path. If set to an empty string, then no
26437 Defaults to @samp{""}.
26441 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
26442 Disable verification of our own server certificates.
26444 When libvirtd starts it performs some sanity checks against its own
26447 Defaults to @samp{#f}.
26451 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
26452 Disable verification of client certificates.
26454 Client certificate verification is the primary authentication mechanism.
26455 Any client which does not present a certificate signed by the CA will be
26458 Defaults to @samp{#f}.
26462 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
26463 Whitelist of allowed x509 Distinguished Name.
26465 Defaults to @samp{()}.
26469 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
26470 Whitelist of allowed SASL usernames. The format for username depends on
26471 the SASL authentication mechanism.
26473 Defaults to @samp{()}.
26477 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
26478 Override the compile time default TLS priority string. The default is
26479 usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
26480 is desired for libvirt to deviate from the global default settings.
26482 Defaults to @samp{"NORMAL"}.
26486 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
26487 Maximum number of concurrent client connections to allow over all
26490 Defaults to @samp{5000}.
26494 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
26495 Maximum length of queue of connections waiting to be accepted by the
26496 daemon. Note, that some protocols supporting retransmission may obey
26497 this so that a later reattempt at connection succeeds.
26499 Defaults to @samp{1000}.
26503 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
26504 Maximum length of queue of accepted but not yet authenticated clients.
26505 Set this to zero to turn this feature off
26507 Defaults to @samp{20}.
26511 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
26512 Number of workers to start up initially.
26514 Defaults to @samp{5}.
26518 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
26519 Maximum number of worker threads.
26521 If the number of active clients exceeds @code{min-workers}, then more
26522 threads are spawned, up to max_workers limit. Typically you'd want
26523 max_workers to equal maximum number of clients allowed.
26525 Defaults to @samp{20}.
26529 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
26530 Number of priority workers. If all workers from above pool are stuck,
26531 some calls marked as high priority (notably domainDestroy) can be
26532 executed in this pool.
26534 Defaults to @samp{5}.
26538 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
26539 Total global limit on concurrent RPC calls.
26541 Defaults to @samp{20}.
26545 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
26546 Limit on concurrent requests from a single client connection. To avoid
26547 one client monopolizing the server this should be a small fraction of
26548 the global max_requests and max_workers parameter.
26550 Defaults to @samp{5}.
26554 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
26555 Same as @code{min-workers} but for the admin interface.
26557 Defaults to @samp{1}.
26561 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
26562 Same as @code{max-workers} but for the admin interface.
26564 Defaults to @samp{5}.
26568 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
26569 Same as @code{max-clients} but for the admin interface.
26571 Defaults to @samp{5}.
26575 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
26576 Same as @code{max-queued-clients} but for the admin interface.
26578 Defaults to @samp{5}.
26582 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
26583 Same as @code{max-client-requests} but for the admin interface.
26585 Defaults to @samp{5}.
26589 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
26590 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
26592 Defaults to @samp{3}.
26596 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
26599 A filter allows to select a different logging level for a given category
26600 of logs. The format for a filter is one of:
26611 where @code{name} is a string which is matched against the category
26612 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
26613 file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
26614 name in the filter can be a substring of the full category name, in
26615 order to match multiple similar categories), the optional @samp{"+"}
26616 prefix tells libvirt to log stack trace for each message matching name,
26617 and @code{x} is the minimal level where matching messages should be
26635 Multiple filters can be defined in a single filters statement, they just
26636 need to be separated by spaces.
26638 Defaults to @samp{"3:remote 4:event"}.
26642 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
26645 An output is one of the places to save logging information. The format
26646 for an output can be:
26650 output goes to stderr
26652 @item x:syslog:name
26653 use syslog for the output and use the given name as the ident
26655 @item x:file:file_path
26656 output to a file, with the given filepath
26659 output to journald logging system
26663 In all case the x prefix is the minimal level, acting as a filter
26680 Multiple outputs can be defined, they just need to be separated by
26683 Defaults to @samp{"3:stderr"}.
26687 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
26688 Allows usage of the auditing subsystem to be altered
26692 0: disable all auditing
26695 1: enable auditing, only if enabled on host
26698 2: enable auditing, and exit if disabled on host.
26702 Defaults to @samp{1}.
26706 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
26707 Send audit messages via libvirt logging infrastructure.
26709 Defaults to @samp{#f}.
26713 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
26714 Host UUID. UUID must not have all digits be the same.
26716 Defaults to @samp{""}.
26720 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
26721 Source to read host UUID.
26725 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
26728 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
26732 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
26735 Defaults to @samp{"smbios"}.
26739 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
26740 A keepalive message is sent to a client after @code{keepalive_interval}
26741 seconds of inactivity to check if the client is still responding. If
26742 set to -1, libvirtd will never send keepalive requests; however clients
26743 can still send them and the daemon will send responses.
26745 Defaults to @samp{5}.
26749 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
26750 Maximum number of keepalive messages that are allowed to be sent to the
26751 client without getting any response before the connection is considered
26754 In other words, the connection is automatically closed approximately
26755 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
26756 the last message received from the client. When @code{keepalive-count}
26757 is set to 0, connections will be automatically closed after
26758 @code{keepalive-interval} seconds of inactivity without sending any
26759 keepalive messages.
26761 Defaults to @samp{5}.
26765 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
26766 Same as above but for admin interface.
26768 Defaults to @samp{5}.
26772 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
26773 Same as above but for admin interface.
26775 Defaults to @samp{5}.
26779 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
26780 Timeout for Open vSwitch calls.
26782 The @code{ovs-vsctl} utility is used for the configuration and its
26783 timeout option is set by default to 5 seconds to avoid potential
26784 infinite waits blocking libvirt.
26786 Defaults to @samp{5}.
26790 @c %end of autogenerated docs
26792 @subsubheading Virtlog daemon
26793 The virtlogd service is a server side daemon component of libvirt that is
26794 used to manage logs from virtual machine consoles.
26796 This daemon is not used directly by libvirt client applications, rather it
26797 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
26798 standalone daemon, the main @code{libvirtd} daemon can be restarted without
26799 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
26800 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
26802 @deffn {Scheme Variable} virtlog-service-type
26803 This is the type of the virtlog daemon.
26804 Its value must be a @code{virtlog-configuration}.
26807 (service virtlog-service-type
26808 (virtlog-configuration
26809 (max-clients 1000)))
26813 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
26814 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
26816 Defaults to @samp{3}.
26820 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
26823 A filter allows to select a different logging level for a given category
26824 of logs The format for a filter is one of:
26835 where @code{name} is a string which is matched against the category
26836 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
26837 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
26838 be a substring of the full category name, in order to match multiple
26839 similar categories), the optional "+" prefix tells libvirt to log stack
26840 trace for each message matching name, and @code{x} is the minimal level
26841 where matching messages should be logged:
26858 Multiple filters can be defined in a single filters statement, they just
26859 need to be separated by spaces.
26861 Defaults to @samp{"3:remote 4:event"}.
26865 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
26868 An output is one of the places to save logging information The format
26869 for an output can be:
26873 output goes to stderr
26875 @item x:syslog:name
26876 use syslog for the output and use the given name as the ident
26878 @item x:file:file_path
26879 output to a file, with the given filepath
26882 output to journald logging system
26886 In all case the x prefix is the minimal level, acting as a filter
26903 Multiple outputs can be defined, they just need to be separated by
26906 Defaults to @samp{"3:stderr"}.
26910 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
26911 Maximum number of concurrent client connections to allow over all
26914 Defaults to @samp{1024}.
26918 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
26919 Maximum file size before rolling over.
26921 Defaults to @samp{2MB}
26925 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
26926 Maximum number of backup files to keep.
26928 Defaults to @samp{3}
26932 @anchor{transparent-emulation-qemu}
26933 @subsubheading Transparent Emulation with QEMU
26936 @cindex @code{binfmt_misc}
26937 @code{qemu-binfmt-service-type} provides support for transparent
26938 emulation of program binaries built for different architectures---e.g.,
26939 it allows you to transparently execute an ARMv7 program on an x86_64
26940 machine. It achieves this by combining the @uref{https://www.qemu.org,
26941 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
26942 This feature only allows you to emulate GNU/Linux on a different
26943 architecture, but see below for GNU/Hurd support.
26945 @defvr {Scheme Variable} qemu-binfmt-service-type
26946 This is the type of the QEMU/binfmt service for transparent emulation.
26947 Its value must be a @code{qemu-binfmt-configuration} object, which
26948 specifies the QEMU package to use as well as the architecture we want to
26952 (service qemu-binfmt-service-type
26953 (qemu-binfmt-configuration
26954 (platforms (lookup-qemu-platforms "arm" "aarch64"))))
26957 In this example, we enable transparent emulation for the ARM and aarch64
26958 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
26959 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
26960 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
26963 @deftp {Data Type} qemu-binfmt-configuration
26964 This is the configuration for the @code{qemu-binfmt} service.
26967 @item @code{platforms} (default: @code{'()})
26968 The list of emulated QEMU platforms. Each item must be a @dfn{platform
26969 object} as returned by @code{lookup-qemu-platforms} (see below).
26971 @item @code{guix-support?} (default: @code{#f})
26972 When it is true, QEMU and all its dependencies are added to the build
26973 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
26974 @option{--chroot-directory} option}). This allows the @code{binfmt_misc}
26975 handlers to be used within the build environment, which in turn means
26976 that you can transparently build programs for another architecture.
26978 For example, let's suppose you're on an x86_64 machine and you have this
26982 (service qemu-binfmt-service-type
26983 (qemu-binfmt-configuration
26984 (platforms (lookup-qemu-platforms "arm"))
26985 (guix-support? #t)))
26991 guix build -s armhf-linux inkscape
26995 and it will build Inkscape for ARMv7 @emph{as if it were a native
26996 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
26997 if you'd like to test a package build for an architecture you don't have
27000 @item @code{qemu} (default: @code{qemu})
27001 The QEMU package to use.
27005 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
27006 Return the list of QEMU platform objects corresponding to
27007 @var{platforms}@dots{}. @var{platforms} must be a list of strings
27008 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
27009 @code{"mips64el"}, and so on.
27012 @deffn {Scheme Procedure} qemu-platform? @var{obj}
27013 Return true if @var{obj} is a platform object.
27016 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
27017 Return the name of @var{platform}---a string such as @code{"arm"}.
27021 @subsubheading The Hurd in a Virtual Machine
27023 @cindex @code{hurd}
27027 Service @code{hurd-vm} provides support for running GNU/Hurd in a
27028 virtual machine (VM), a so-called @dfn{childhurd}. This service is meant
27029 to be used on GNU/Linux and the given GNU/Hurd operating system
27030 configuration is cross-compiled. The virtual machine is a Shepherd
27031 service that can be referred to by the names @code{hurd-vm} and
27032 @code{childhurd} and be controlled with commands such as:
27036 herd stop childhurd
27039 When the service is running, you can view its console by connecting to
27040 it with a VNC client, for example with:
27043 guix environment --ad-hoc tigervnc-client -- \
27044 vncviewer localhost:5900
27047 The default configuration (see @code{hurd-vm-configuration} below)
27048 spawns a secure shell (SSH) server in your GNU/Hurd system, which QEMU
27049 (the virtual machine emulator) redirects to port 10222 on the host.
27050 Thus, you can connect over SSH to the childhurd with:
27053 ssh root@@localhost -p 10022
27056 The childhurd is volatile and stateless: it starts with a fresh root
27057 file system every time you restart it. By default though, all the files
27058 under @file{/etc/childhurd} on the host are copied as is to the root
27059 file system of the childhurd when it boots. This allows you to
27060 initialize ``secrets'' inside the VM: SSH host keys, authorized
27061 substitute keys, and so on---see the explanation of @code{secret-root}
27064 @defvr {Scheme Variable} hurd-vm-service-type
27065 This is the type of the Hurd in a Virtual Machine service. Its value
27066 must be a @code{hurd-vm-configuration} object, which specifies the
27067 operating system (@pxref{operating-system Reference}) and the disk size
27068 for the Hurd Virtual Machine, the QEMU package to use as well as the
27069 options for running it.
27074 (service hurd-vm-service-type
27075 (hurd-vm-configuration
27076 (disk-size (* 5000 (expt 2 20))) ;5G
27077 (memory-size 1024))) ;1024MiB
27080 would create a disk image big enough to build GNU@tie{}Hello, with some
27084 @deftp {Data Type} hurd-vm-configuration
27085 The data type representing the configuration for
27086 @code{hurd-vm-service-type}.
27089 @item @code{os} (default: @var{%hurd-vm-operating-system})
27090 The operating system to instantiate. This default is bare-bones with a
27091 permissive OpenSSH secure shell daemon listening on port 2222
27092 (@pxref{Networking Services, @code{openssh-service-type}}).
27094 @item @code{qemu} (default: @code{qemu-minimal})
27095 The QEMU package to use.
27097 @item @code{image} (default: @var{hurd-vm-disk-image})
27098 The procedure used to build the disk-image built from this
27101 @item @code{disk-size} (default: @code{'guess})
27102 The size of the disk image.
27104 @item @code{memory-size} (default: @code{512})
27105 The memory size of the Virtual Machine in mebibytes.
27107 @item @code{options} (default: @code{'("--snapshot")})
27108 The extra options for running QEMU.
27110 @item @code{id} (default: @code{#f})
27111 If set, a non-zero positive integer used to parameterize Childhurd
27112 instances. It is appended to the service's name,
27113 e.g. @code{childhurd1}.
27115 @item @code{net-options} (default: @var{hurd-vm-net-options})
27116 The procedure used to produce the list of QEMU networking options.
27118 By default, it produces
27121 '("--device" "rtl8139,netdev=net0"
27122 "--netdev" "user,id=net0\
27123 ,hostfwd=tcp:127.0.0.1:@var{secrets-port}-:1004\
27124 ,hostfwd=tcp:127.0.0.1:@var{ssh-port}-:2222\
27125 ,hostfwd=tcp:127.0.0.1:@var{vnc-port}-:5900")
27128 with forwarded ports:
27131 @var{secrets-port}: @code{(+ 11004 (* 1000 @var{ID}))}
27132 @var{ssh-port}: @code{(+ 10022 (* 1000 @var{ID}))}
27133 @var{vnc-port}: @code{(+ 15900 (* 1000 @var{ID}))}
27136 @item @code{secret-root} (default: @file{/etc/childhurd})
27137 The root directory with out-of-band secrets to be installed into the
27138 childhurd once it runs. Childhurds are volatile which means that on
27139 every startup, secrets such as the SSH host keys and Guix signing key
27142 If the @file{/etc/childhurd} directory does not exist, the
27143 @code{secret-service} running in the Childhurd will be sent an empty
27146 By default, the service automatically populates @file{/etc/childhurd}
27147 with the following non-volatile secrets, unless they already exist:
27150 /etc/childhurd/etc/guix/acl
27151 /etc/childhurd/etc/guix/signing-key.pub
27152 /etc/childhurd/etc/guix/signing-key.sec
27153 /etc/childhurd/etc/ssh/ssh_host_ed25519_key
27154 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key
27155 /etc/childhurd/etc/ssh/ssh_host_ed25519_key.pub
27156 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key.pub
27159 These files are automatically sent to the guest Hurd VM when it boots,
27160 including permissions.
27162 @cindex childhurd, offloading
27163 @cindex Hurd, offloading
27164 Having these files in place means that only a couple of things are
27165 missing to allow the host to offload @code{i586-gnu} builds to the
27170 Authorizing the childhurd's key on the host so that the host accepts
27171 build results coming from the childhurd, which can be done like so:
27174 guix archive --authorize < \
27175 /etc/childhurd/etc/guix/signing-key.pub
27179 Adding the childhurd to @file{/etc/guix/machines.scm} (@pxref{Daemon
27183 We're working towards making that happen automatically---get in touch
27184 with us at @email{guix-devel@@gnu.org} to discuss it!
27188 Note that by default the VM image is volatile, i.e., once stopped the
27189 contents are lost. If you want a stateful image instead, override the
27190 configuration's @code{image} and @code{options} without
27191 the @code{--snapshot} flag using something along these lines:
27194 (service hurd-vm-service-type
27195 (hurd-vm-configuration
27196 (image (const "/out/of/store/writable/hurd.img"))
27200 @subsubheading Ganeti
27205 This service is considered experimental. Configuration options may be changed
27206 in a backwards-incompatible manner, and not all features have been thorougly
27207 tested. Users of this service are encouraged to share their experience at
27208 @email{guix-devel@@gnu.org}.
27211 Ganeti is a virtual machine management system. It is designed to keep virtual
27212 machines running on a cluster of servers even in the event of hardware failures,
27213 and to make maintenance and recovery tasks easy. It consists of multiple
27214 services which are described later in this section. In addition to the Ganeti
27215 service, you will need the OpenSSH service (@pxref{Networking Services,
27216 @code{openssh-service-type}}), and update the @file{/etc/hosts} file
27217 (@pxref{operating-system Reference, @code{hosts-file}}) with the cluster name
27218 and address (or use a DNS server).
27220 All nodes participating in a Ganeti cluster should have the same Ganeti and
27221 @file{/etc/hosts} configuration. Here is an example configuration for a Ganeti
27222 cluster node that supports multiple storage backends, and installs the
27223 @code{debootstrap} and @code{guix} @dfn{OS providers}:
27226 (use-package-modules virtualization)
27227 (use-service-modules base ganeti networking ssh)
27230 (host-name "node1")
27231 (hosts-file (plain-file "hosts" (format #f "
27232 127.0.0.1 localhost
27235 192.168.1.200 ganeti.example.com
27236 192.168.1.201 node1.example.com node1
27237 192.168.1.202 node2.example.com node2
27240 ;; Install QEMU so we can use KVM-based instances, and LVM, DRBD and Ceph
27241 ;; in order to use the "plain", "drbd" and "rbd" storage backends.
27242 (packages (append (map specification->package
27243 '("qemu" "lvm2" "drbd-utils" "ceph"
27244 ;; Add the debootstrap and guix OS providers.
27245 "ganeti-instance-guix" "ganeti-instance-debootstrap"))
27248 (append (list (static-networking-service "eth0" "192.168.1.201"
27249 #:netmask "255.255.255.0"
27250 #:gateway "192.168.1.254"
27251 #:name-servers '("192.168.1.252"
27254 ;; Ganeti uses SSH to communicate between nodes.
27255 (service openssh-service-type
27256 (openssh-configuration
27257 (permit-root-login 'without-password)))
27259 (service ganeti-service-type
27260 (ganeti-configuration
27261 ;; This list specifies allowed file system paths
27262 ;; for storing virtual machine images.
27263 (file-storage-paths '("/srv/ganeti/file-storage"))
27264 ;; This variable configures a single "variant" for
27265 ;; both Debootstrap and Guix that works with KVM.
27266 (os %default-ganeti-os))))
27270 Users are advised to read the
27271 @url{http://docs.ganeti.org/ganeti/master/html/admin.html,Ganeti
27272 administrators guide} to learn about the various cluster options and
27273 day-to-day operations. There is also a
27274 @url{https://guix.gnu.org/blog/2020/running-a-ganeti-cluster-on-guix/,blog post}
27275 describing how to configure and initialize a small cluster.
27277 @defvr {Scheme Variable} ganeti-service-type
27278 This is a service type that includes all the various services that Ganeti
27281 Its value is a @code{ganeti-configuration} object that defines the package
27282 to use for CLI operations, as well as configuration for the various daemons.
27283 Allowed file storage paths and available guest operating systems are also
27284 configured through this data type.
27287 @deftp {Data Type} ganeti-configuration
27288 The @code{ganeti} service takes the following configuration options:
27291 @item @code{ganeti} (default: @code{ganeti})
27292 The @code{ganeti} package to use. It will be installed to the system profile
27293 and make @command{gnt-cluster}, @command{gnt-instance}, etc available. Note
27294 that the value specified here does not affect the other services as each refer
27295 to a specific @code{ganeti} package (see below).
27297 @item @code{noded-configuration} (default: @code{(ganeti-noded-configuration)})
27298 @itemx @code{confd-configuration} (default: @code{(ganeti-confd-configuration)})
27299 @itemx @code{wconfd-configuration} (default: @code{(ganeti-wconfd-configuration)})
27300 @itemx @code{luxid-configuration} (default: @code{(ganeti-luxid-configuration)})
27301 @itemx @code{rapi-configuration} (default: @code{(ganeti-rapi-configuration)})
27302 @itemx @code{kvmd-configuration} (default: @code{(ganeti-kvmd-configuration)})
27303 @itemx @code{mond-configuration} (default: @code{(ganeti-mond-configuration)})
27304 @itemx @code{metad-configuration} (default: @code{(ganeti-metad-configuration)})
27305 @itemx @code{watcher-configuration} (default: @code{(ganeti-watcher-configuration)})
27306 @itemx @code{cleaner-configuration} (default: @code{(ganeti-cleaner-configuration)})
27308 These options control the various daemons and cron jobs that are distributed
27309 with Ganeti. The possible values for these are described in detail below.
27310 To override a setting, you must use the configuration type for that service:
27313 (service ganeti-service-type
27314 (ganeti-configuration
27315 (rapi-configuration
27316 (ganeti-rapi-configuration
27317 (interface "eth1"))))
27318 (watcher-configuration
27319 (ganeti-watcher-configuration
27320 (rapi-ip "10.0.0.1"))))
27323 @item @code{file-storage-paths} (default: @code{'()})
27324 List of allowed directories for file storage backend.
27326 @item @code{os} (default: @code{%default-ganeti-os})
27327 List of @code{<ganeti-os>} records.
27330 In essence @code{ganeti-service-type} is shorthand for declaring each service
27334 (service ganeti-noded-service-type)
27335 (service ganeti-confd-service-type)
27336 (service ganeti-wconfd-service-type)
27337 (service ganeti-luxid-service-type)
27338 (service ganeti-kvmd-service-type)
27339 (service ganeti-mond-service-type)
27340 (service ganeti-metad-service-type)
27341 (service ganeti-watcher-service-type)
27342 (service ganeti-cleaner-service-type)
27345 Plus a service extension for @code{etc-service-type} that configures the file
27346 storage backend and OS variants.
27350 @deftp {Data Type} ganeti-os
27351 This data type is suitable for passing to the @code{os} parameter of
27352 @code{ganeti-configuration}. It takes the following parameters:
27356 The name for this OS provider. It is only used to specify where the
27357 configuration ends up. Setting it to ``debootstrap'' will create
27358 @file{/etc/ganeti/instance-debootstrap}.
27360 @item @code{extension}
27361 The file extension for variants of this OS type. For example
27362 @file{.conf} or @file{.scm}.
27364 @item @code{variants} (default: @code{'()})
27365 List of @code{ganeti-os-variant} objects for this OS.
27370 @deftp {Data Type} ganeti-os-variant
27371 This is the data type for a Ganeti OS variant. It takes the following
27376 The name of this variant.
27378 @item @code{configuration}
27379 A configuration file for this variant.
27383 @defvr {Scheme Variable} %default-debootstrap-hooks
27384 This variable contains hooks to configure networking and the GRUB bootloader.
27387 @defvr {Scheme Variable} %default-debootstrap-extra-pkgs
27388 This variable contains a list of packages suitable for a fully-virtualized guest.
27391 @deftp {Data Type} debootstrap-configuration
27393 This data type creates configuration files suitable for the debootstrap OS provider.
27396 @item @code{hooks} (default: @code{%default-debootstrap-hooks})
27397 When not @code{#f}, this must be a G-expression that specifies a directory with
27398 scripts that will run when the OS is installed. It can also be a list of
27399 @code{(name . file-like)} pairs. For example:
27402 `((99-hello-world . ,(plain-file "#!/bin/sh\necho Hello, World")))
27405 That will create a directory with one executable named @code{99-hello-world}
27406 and run it every time this variant is installed. If set to @code{#f}, hooks
27407 in @file{/etc/ganeti/instance-debootstrap/hooks} will be used, if any.
27408 @item @code{proxy} (default: @code{#f})
27409 Optional HTTP proxy to use.
27410 @item @code{mirror} (default: @code{#f})
27411 The Debian mirror. Typically something like @code{http://ftp.no.debian.org/debian}.
27412 The default varies depending on the distribution.
27413 @item @code{arch} (default: @code{#f})
27414 The dpkg architecture. Set to @code{armhf} to debootstrap an ARMv7 instance
27415 on an AArch64 host. Default is to use the current system architecture.
27416 @item @code{suite} (default: @code{"stable"})
27417 When set, this must be a Debian distribution ``suite'' such as @code{buster}
27418 or @code{focal}. If set to @code{#f}, the default for the OS provider is used.
27419 @item @code{extra-pkgs} (default: @code{%default-debootstrap-extra-pkgs})
27420 List of extra packages that will get installed by dpkg in addition
27421 to the minimal system.
27422 @item @code{components} (default: @code{#f})
27423 When set, must be a list of Debian repository ``components''. For example
27424 @code{'("main" "contrib")}.
27425 @item @code{generate-cache?} (default: @code{#t})
27426 Whether to automatically cache the generated debootstrap archive.
27427 @item @code{clean-cache} (default: @code{14})
27428 Discard the cache after this amount of days. Use @code{#f} to never
27430 @item @code{partition-style} (default: @code{'msdos})
27431 The type of partition to create. When set, it must be one of
27432 @code{'msdos}, @code{'none} or a string.
27433 @item @code{partition-alignment} (default: @code{2048})
27434 Alignment of the partition in sectors.
27438 @deffn {Scheme Procedure} debootstrap-variant @var{name} @var{configuration}
27439 This is a helper procedure that creates a @code{ganeti-os-variant} record. It
27440 takes two parameters: a name and a @code{debootstrap-configuration} object.
27443 @deffn {Scheme Procedure} debootstrap-os @var{variants}@dots{}
27444 This is a helper procedure that creates a @code{ganeti-os} record. It takes
27445 a list of variants created with @code{debootstrap-variant}.
27448 @deffn {Scheme Procedure} guix-variant @var{name} @var{configuration}
27449 This is a helper procedure that creates a @code{ganeti-os-variant} record for
27450 use with the Guix OS provider. It takes a name and a G-expression that returns
27451 a ``file-like'' (@pxref{G-Expressions, file-like objects}) object containing a
27452 Guix System configuration.
27455 @deffn {Scheme Procedure} guix-os @var{variants}@dots{}
27456 This is a helper procedure that creates a @code{ganeti-os} record. It
27457 takes a list of variants produced by @code{guix-variant}.
27460 @defvr {Scheme Variable} %default-debootstrap-variants
27461 This is a convenience variable to make the debootstrap provider work
27462 ``out of the box'' without users having to declare variants manually. It
27463 contains a single debootstrap variant with the default configuration:
27466 (list (debootstrap-variant
27468 (debootstrap-configuration)))
27472 @defvr {Scheme Variable} %default-guix-variants
27473 This is a convenience variable to make the Guix OS provider work without
27474 additional configuration. It creates a virtual machine that has an SSH
27475 server, a serial console, and authorizes the Ganeti hosts SSH keys.
27478 (list (guix-variant
27480 (file-append ganeti-instance-guix
27481 "/share/doc/ganeti-instance-guix/examples/dynamic.scm")))
27485 Users can implement support for OS providers unbeknownst to Guix by extending
27486 the @code{ganeti-os} and @code{ganeti-os-variant} records appropriately.
27492 (extension ".conf")
27494 (list (ganeti-os-variant
27496 (configuration (plain-file "bar" "this is fine"))))))
27499 That creates @file{/etc/ganeti/instance-custom/variants/foo.conf} which points
27500 to a file in the store with contents @code{this is fine}. It also creates
27501 @file{/etc/ganeti/instance-custom/variants/variants.list} with contents @code{foo}.
27503 Obviously this may not work for all OS providers out there. If you find the
27504 interface limiting, please reach out to @email{guix-devel@@gnu.org}.
27506 The rest of this section documents the various services that are included by
27507 @code{ganeti-service-type}.
27509 @defvr {Scheme Variable} ganeti-noded-service-type
27510 @command{ganeti-noded} is the daemon responsible for node-specific functions
27511 within the Ganeti system. The value of this service must be a
27512 @code{ganeti-noded-configuration} object.
27515 @deftp {Data Type} ganeti-noded-configuration
27516 This is the configuration for the @code{ganeti-noded} service.
27519 @item @code{ganeti} (default: @code{ganeti})
27520 The @code{ganeti} package to use for this service.
27522 @item @code{port} (default: @code{1811})
27523 The TCP port on which the node daemon listens for network requests.
27525 @item @code{address} (default: @code{"0.0.0.0"})
27526 The network address that the daemon will bind to. The default address means
27527 bind to all available addresses.
27529 @item @code{interface} (default: @code{#f})
27530 When this is set, it must be a specific network interface (e.g.@: @code{eth0})
27531 that the daemon will bind to.
27533 @item @code{max-clients} (default: @code{20})
27534 This sets a limit on the maximum number of simultaneous client connections
27535 that the daemon will handle. Connections above this count are accepted, but
27536 no responses will be sent until enough connections have closed.
27538 @item @code{ssl?} (default: @code{#t})
27539 Whether to use SSL/TLS to encrypt network communications. The certificate
27540 is automatically provisioned by the cluster and can be rotated with
27541 @command{gnt-cluster renew-crypto}.
27543 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
27544 This can be used to provide a specific encryption key for TLS communications.
27546 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
27547 This can be used to provide a specific certificate for TLS communications.
27549 @item @code{debug?} (default: @code{#f})
27550 When true, the daemon performs additional logging for debugging purposes.
27551 Note that this will leak encryption details to the log files, use with caution.
27556 @defvr {Scheme Variable} ganeti-confd-service-type
27557 @command{ganeti-confd} answers queries related to the configuration of a
27558 Ganeti cluster. The purpose of this daemon is to have a highly available
27559 and fast way to query cluster configuration values. It is automatically
27560 active on all @dfn{master candidates}. The value of this service must be a
27561 @code{ganeti-confd-configuration} object.
27565 @deftp {Data Type} ganeti-confd-configuration
27566 This is the configuration for the @code{ganeti-confd} service.
27569 @item @code{ganeti} (default: @code{ganeti})
27570 The @code{ganeti} package to use for this service.
27572 @item @code{port} (default: @code{1814})
27573 The UDP port on which to listen for network requests.
27575 @item @code{address} (default: @code{"0.0.0.0"})
27576 Network address that the daemon will bind to.
27578 @item @code{debug?} (default: @code{#f})
27579 When true, the daemon performs additional logging for debugging purposes.
27584 @defvr {Scheme Variable} ganeti-wconfd-service-type
27585 @command{ganeti-wconfd} is the daemon that has authoritative knowledge
27586 about the cluster configuration and is the only entity that can accept
27587 changes to it. All jobs that need to modify the configuration will do so
27588 by sending appropriate requests to this daemon. It only runs on the
27589 @dfn{master node} and will automatically disable itself on other nodes.
27591 The value of this service must be a
27592 @code{ganeti-wconfd-configuration} object.
27595 @deftp {Data Type} ganeti-wconfd-configuration
27596 This is the configuration for the @code{ganeti-wconfd} service.
27599 @item @code{ganeti} (default: @code{ganeti})
27600 The @code{ganeti} package to use for this service.
27602 @item @code{no-voting?} (default: @code{#f})
27603 The daemon will refuse to start if the majority of cluster nodes does not
27604 agree that it is running on the master node. Set to @code{#t} to start
27605 even if a quorum can not be reached (dangerous, use with caution).
27607 @item @code{debug?} (default: @code{#f})
27608 When true, the daemon performs additional logging for debugging purposes.
27613 @defvr {Scheme Variable} ganeti-luxid-service-type
27614 @command{ganeti-luxid} is a daemon used to answer queries related to the
27615 configuration and the current live state of a Ganeti cluster. Additionally,
27616 it is the authoritative daemon for the Ganeti job queue. Jobs can be
27617 submitted via this daemon and it schedules and starts them.
27619 It takes a @code{ganeti-luxid-configuration} object.
27622 @deftp {Data Type} ganeti-luxid-configuration
27623 This is the configuration for the @code{ganeti-wconfd} service.
27626 @item @code{ganeti} (default: @code{ganeti})
27627 The @code{ganeti} package to use for this service.
27629 @item @code{no-voting?} (default: @code{#f})
27630 The daemon will refuse to start if it cannot verify that the majority of
27631 cluster nodes believes that it is running on the master node. Set to
27632 @code{#t} to ignore such checks and start anyway (this can be dangerous).
27634 @item @code{debug?} (default: @code{#f})
27635 When true, the daemon performs additional logging for debugging purposes.
27640 @defvr {Scheme Variable} ganeti-rapi-service-type
27641 @command{ganeti-rapi} provides a remote API for Ganeti clusters. It runs on
27642 the master node and can be used to perform cluster actions programmatically
27643 via a JSON-based RPC protocol.
27645 Most query operations are allowed without authentication (unless
27646 @var{require-authentication?} is set), whereas write operations require
27647 explicit authorization via the @file{/var/lib/ganeti/rapi/users} file. See
27648 the @url{http://docs.ganeti.org/ganeti/master/html/rapi.html, Ganeti Remote
27649 API documentation} for more information.
27651 The value of this service must be a @code{ganeti-rapi-configuration} object.
27654 @deftp {Data Type} ganeti-rapi-configuration
27655 This is the configuration for the @code{ganeti-rapi} service.
27658 @item @code{ganeti} (default: @code{ganeti})
27659 The @code{ganeti} package to use for this service.
27661 @item @code{require-authentication?} (default: @code{#f})
27662 Whether to require authentication even for read-only operations.
27664 @item @code{port} (default: @code{5080})
27665 The TCP port on which to listen to API requests.
27667 @item @code{address} (default: @code{"0.0.0.0"})
27668 The network address that the service will bind to. By default it listens
27669 on all configured addresses.
27671 @item @code{interface} (default: @code{#f})
27672 When set, it must specify a specific network interface such as @code{eth0}
27673 that the daemon will bind to.
27675 @item @code{max-clients} (default: @code{20})
27676 The maximum number of simultaneous client requests to handle. Further
27677 connections are allowed, but no responses are sent until enough connections
27680 @item @code{ssl?} (default: @code{#t})
27681 Whether to use SSL/TLS encryption on the RAPI port.
27683 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
27684 This can be used to provide a specific encryption key for TLS communications.
27686 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
27687 This can be used to provide a specific certificate for TLS communications.
27689 @item @code{debug?} (default: @code{#f})
27690 When true, the daemon performs additional logging for debugging purposes.
27691 Note that this will leak encryption details to the log files, use with caution.
27696 @defvr {Scheme Variable} ganeti-kvmd-service-type
27697 @command{ganeti-kvmd} is responsible for determining whether a given KVM
27698 instance was shut down by an administrator or a user. Normally Ganeti will
27699 restart an instance that was not stopped through Ganeti itself. If the
27700 cluster option @code{user_shutdown} is true, this daemon monitors the
27701 @code{QMP} socket provided by QEMU and listens for shutdown events, and
27702 marks the instance as @dfn{USER_down} instead of @dfn{ERROR_down} when
27703 it shuts down gracefully by itself.
27705 It takes a @code{ganeti-kvmd-configuration} object.
27708 @deftp {Data Type} ganeti-kvmd-configuration
27711 @item @code{ganeti} (default: @code{ganeti})
27712 The @code{ganeti} package to use for this service.
27714 @item @code{debug?} (default: @code{#f})
27715 When true, the daemon performs additional logging for debugging purposes.
27720 @defvr {Scheme Variable} ganeti-mond-service-type
27721 @command{ganeti-mond} is an optional daemon that provides Ganeti monitoring
27722 functionality. It is responsible for running data collectors and publish the
27723 collected information through a HTTP interface.
27725 It takes a @code{ganeti-mond-configuration} object.
27728 @deftp {Data Type} ganeti-mond-configuration
27731 @item @code{ganeti} (default: @code{ganeti})
27732 The @code{ganeti} package to use for this service.
27734 @item @code{port} (default: @code{1815})
27735 The port on which the daemon will listen.
27737 @item @code{address} (default: @code{"0.0.0.0"})
27738 The network address that the daemon will bind to. By default it binds to all
27739 available interfaces.
27741 @item @code{debug?} (default: @code{#f})
27742 When true, the daemon performs additional logging for debugging purposes.
27747 @defvr {Scheme Variable} ganeti-metad-service-type
27748 @command{ganeti-metad} is an optional daemon that can be used to provide
27749 information about the cluster to instances or OS install scripts.
27751 It takes a @code{ganeti-metad-configuration} object.
27754 @deftp {Data Type} ganeti-metad-configuration
27757 @item @code{ganeti} (default: @code{ganeti})
27758 The @code{ganeti} package to use for this service.
27760 @item @code{port} (default: @code{80})
27761 The port on which the daemon will listen.
27763 @item @code{address} (default: @code{#f})
27764 If set, the daemon will bind to this address only. If left unset, the behavior
27765 depends on the cluster configuration.
27767 @item @code{debug?} (default: @code{#f})
27768 When true, the daemon performs additional logging for debugging purposes.
27773 @defvr {Scheme Variable} ganeti-watcher-service-type
27774 @command{ganeti-watcher} is a script designed to run periodically and ensure
27775 the health of a cluster. It will automatically restart instances that have
27776 stopped without Ganeti's consent, and repairs DRBD links in case a node has
27777 rebooted. It also archives old cluster jobs and restarts Ganeti daemons
27778 that are not running. If the cluster parameter @code{ensure_node_health}
27779 is set, the watcher will also shutdown instances and DRBD devices if the
27780 node it is running on is declared offline by known master candidates.
27782 It can be paused on all nodes with @command{gnt-cluster watcher pause}.
27784 The service takes a @code{ganeti-watcher-configuration} object.
27787 @deftp {Data Type} ganeti-watcher-configuration
27790 @item @code{ganeti} (default: @code{ganeti})
27791 The @code{ganeti} package to use for this service.
27793 @item @code{schedule} (default: @code{'(next-second-from (next-minute (range 0 60 5)))})
27794 How often to run the script. The default is every five minutes.
27796 @item @code{rapi-ip} (default: @code{#f})
27797 This option needs to be specified only if the RAPI daemon is configured to use
27798 a particular interface or address. By default the cluster address is used.
27800 @item @code{job-age} (default: @code{(* 6 3600)})
27801 Archive cluster jobs older than this age, specified in seconds. The default
27802 is 6 hours. This keeps @command{gnt-job list} manageable.
27804 @item @code{verify-disks?} (default: @code{#t})
27805 If this is @code{#f}, the watcher will not try to repair broken DRBD links
27806 automatically. Administrators will need to use @command{gnt-cluster verify-disks}
27809 @item @code{debug?} (default: @code{#f})
27810 When @code{#t}, the script performs additional logging for debugging purposes.
27815 @defvr {Scheme Variable} ganeti-cleaner-service-type
27816 @command{ganeti-cleaner} is a script designed to run periodically and remove
27817 old files from the cluster. This service type controls two @dfn{cron jobs}:
27818 one intended for the master node that permanently purges old cluster jobs,
27819 and one intended for every node that removes expired X509 certificates, keys,
27820 and outdated @command{ganeti-watcher} information. Like all Ganeti services,
27821 it is safe to include even on non-master nodes as it will disable itself as
27824 It takes a @code{ganeti-cleaner-configuration} object.
27827 @deftp {Data Type} ganeti-cleaner-configuration
27830 @item @code{ganeti} (default: @code{ganeti})
27831 The @code{ganeti} package to use for the @command{gnt-cleaner} command.
27833 @item @code{master-schedule} (default: @code{"45 1 * * *"})
27834 How often to run the master cleaning job. The default is once per day, at
27837 @item @code{node-schedule} (default: @code{"45 2 * * *"})
27838 How often to run the node cleaning job. The default is once per day, at
27844 @node Version Control Services
27845 @subsection Version Control Services
27847 The @code{(gnu services version-control)} module provides a service to
27848 allow remote access to local Git repositories. There are three options:
27849 the @code{git-daemon-service}, which provides access to repositories via
27850 the @code{git://} unsecured TCP-based protocol, extending the
27851 @code{nginx} web server to proxy some requests to
27852 @code{git-http-backend}, or providing a web interface with
27853 @code{cgit-service-type}.
27855 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
27857 Return a service that runs @command{git daemon}, a simple TCP server to
27858 expose repositories over the Git protocol for anonymous access.
27860 The optional @var{config} argument should be a
27861 @code{<git-daemon-configuration>} object, by default it allows read-only
27862 access to exported@footnote{By creating the magic file
27863 @file{git-daemon-export-ok} in the repository directory.} repositories under
27868 @deftp {Data Type} git-daemon-configuration
27869 Data type representing the configuration for @code{git-daemon-service}.
27872 @item @code{package} (default: @code{git})
27873 Package object of the Git distributed version control system.
27875 @item @code{export-all?} (default: @code{#f})
27876 Whether to allow access for all Git repositories, even if they do not
27877 have the @file{git-daemon-export-ok} file.
27879 @item @code{base-path} (default: @file{/srv/git})
27880 Whether to remap all the path requests as relative to the given path.
27881 If you run @command{git daemon} with @code{(base-path "/srv/git")} on
27882 @samp{example.com}, then if you later try to pull
27883 @indicateurl{git://example.com/hello.git}, git daemon will interpret the
27884 path as @file{/srv/git/hello.git}.
27886 @item @code{user-path} (default: @code{#f})
27887 Whether to allow @code{~user} notation to be used in requests. When
27888 specified with empty string, requests to
27889 @indicateurl{git://host/~alice/foo} is taken as a request to access
27890 @code{foo} repository in the home directory of user @code{alice}. If
27891 @code{(user-path "@var{path}")} is specified, the same request is taken
27892 as a request to access @file{@var{path}/foo} repository in the home
27893 directory of user @code{alice}.
27895 @item @code{listen} (default: @code{'()})
27896 Whether to listen on specific IP addresses or hostnames, defaults to
27899 @item @code{port} (default: @code{#f})
27900 Whether to listen on an alternative port, which defaults to 9418.
27902 @item @code{whitelist} (default: @code{'()})
27903 If not empty, only allow access to this list of directories.
27905 @item @code{extra-options} (default: @code{'()})
27906 Extra options will be passed to @command{git daemon}, please run
27907 @command{man git-daemon} for more information.
27912 The @code{git://} protocol lacks authentication. When you pull from a
27913 repository fetched via @code{git://}, you don't know whether the data you
27914 receive was modified or is even coming from the specified host, and your
27915 connection is subject to eavesdropping. It's better to use an authenticated
27916 and encrypted transport, such as @code{https}. Although Git allows you
27917 to serve repositories using unsophisticated file-based web servers,
27918 there is a faster protocol implemented by the @code{git-http-backend}
27919 program. This program is the back-end of a proper Git web service. It
27920 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
27921 on running the necessary @code{fcgiwrap} daemon.
27923 Guix has a separate configuration data type for serving Git repositories
27926 @deftp {Data Type} git-http-configuration
27927 Data type representing the configuration for a future
27928 @code{git-http-service-type}; can currently be used to configure Nginx
27929 trough @code{git-http-nginx-location-configuration}.
27932 @item @code{package} (default: @var{git})
27933 Package object of the Git distributed version control system.
27935 @item @code{git-root} (default: @file{/srv/git})
27936 Directory containing the Git repositories to expose to the world.
27938 @item @code{export-all?} (default: @code{#f})
27939 Whether to expose access for all Git repositories in @var{git-root},
27940 even if they do not have the @file{git-daemon-export-ok} file.
27942 @item @code{uri-path} (default: @samp{/git/})
27943 Path prefix for Git access. With the default @samp{/git/} prefix, this
27944 will map @indicateurl{http://@var{server}/git/@var{repo}.git} to
27945 @file{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
27946 with this prefix are not passed on to this Git instance.
27948 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
27949 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
27954 There is no @code{git-http-service-type}, currently; instead you can
27955 create an @code{nginx-location-configuration} from a
27956 @code{git-http-configuration} and then add that location to a web
27959 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
27960 [config=(git-http-configuration)]
27961 Compute an @code{nginx-location-configuration} that corresponds to the
27962 given Git http configuration. An example nginx service definition to
27963 serve the default @file{/srv/git} over HTTPS might be:
27966 (service nginx-service-type
27967 (nginx-configuration
27970 (nginx-server-configuration
27971 (listen '("443 ssl"))
27972 (server-name "git.my-host.org")
27974 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
27975 (ssl-certificate-key
27976 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
27979 (git-http-nginx-location-configuration
27980 (git-http-configuration (uri-path "/"))))))))))
27983 This example assumes that you are using Let's Encrypt to get your TLS
27984 certificate. @xref{Certificate Services}. The default @code{certbot}
27985 service will redirect all HTTP traffic on @code{git.my-host.org} to
27986 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
27987 system services. @xref{Web Services}.
27990 @subsubheading Cgit Service
27992 @cindex Cgit service
27993 @cindex Git, web interface
27994 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
27995 repositories written in C.
27997 The following example will configure the service with default values.
27998 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
28001 (service cgit-service-type)
28004 The @code{file-object} type designates either a file-like object
28005 (@pxref{G-Expressions, file-like objects}) or a string.
28007 @c %start of fragment
28009 Available @code{cgit-configuration} fields are:
28011 @deftypevr {@code{cgit-configuration} parameter} package package
28016 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
28017 NGINX configuration.
28021 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
28022 Specifies a command which will be invoked to format the content of about
28023 pages (both top-level and for each repository).
28025 Defaults to @samp{""}.
28029 @deftypevr {@code{cgit-configuration} parameter} string agefile
28030 Specifies a path, relative to each repository path, which can be used to
28031 specify the date and time of the youngest commit in the repository.
28033 Defaults to @samp{""}.
28037 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
28038 Specifies a command that will be invoked for authenticating repository
28041 Defaults to @samp{""}.
28045 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
28046 Flag which, when set to @samp{age}, enables date ordering in the branch
28047 ref list, and when set @samp{name} enables ordering by branch name.
28049 Defaults to @samp{"name"}.
28053 @deftypevr {@code{cgit-configuration} parameter} string cache-root
28054 Path used to store the cgit cache entries.
28056 Defaults to @samp{"/var/cache/cgit"}.
28060 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
28061 Number which specifies the time-to-live, in minutes, for the cached
28062 version of repository pages accessed with a fixed SHA1.
28064 Defaults to @samp{-1}.
28068 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
28069 Number which specifies the time-to-live, in minutes, for the cached
28070 version of repository pages accessed without a fixed SHA1.
28072 Defaults to @samp{5}.
28076 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
28077 Number which specifies the time-to-live, in minutes, for the cached
28078 version of the repository summary page.
28080 Defaults to @samp{5}.
28084 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
28085 Number which specifies the time-to-live, in minutes, for the cached
28086 version of the repository index page.
28088 Defaults to @samp{5}.
28092 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
28093 Number which specifies the time-to-live, in minutes, for the result of
28094 scanning a path for Git repositories.
28096 Defaults to @samp{15}.
28100 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
28101 Number which specifies the time-to-live, in minutes, for the cached
28102 version of the repository about page.
28104 Defaults to @samp{15}.
28108 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
28109 Number which specifies the time-to-live, in minutes, for the cached
28110 version of snapshots.
28112 Defaults to @samp{5}.
28116 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
28117 The maximum number of entries in the cgit cache. When set to @samp{0},
28118 caching is disabled.
28120 Defaults to @samp{0}.
28124 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
28125 Sort items in the repo list case sensitively.
28127 Defaults to @samp{#t}.
28131 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
28132 List of common prefixes which, when combined with a repository URL,
28133 generates valid clone URLs for the repository.
28135 Defaults to @samp{()}.
28139 @deftypevr {@code{cgit-configuration} parameter} list clone-url
28140 List of @code{clone-url} templates.
28142 Defaults to @samp{()}.
28146 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
28147 Command which will be invoked to format commit messages.
28149 Defaults to @samp{""}.
28153 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
28154 Flag which, when set to @samp{date}, enables strict date ordering in the
28155 commit log, and when set to @samp{topo} enables strict topological
28158 Defaults to @samp{"git log"}.
28162 @deftypevr {@code{cgit-configuration} parameter} file-object css
28163 URL which specifies the css document to include in all cgit pages.
28165 Defaults to @samp{"/share/cgit/cgit.css"}.
28169 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
28170 Specifies a command which will be invoked to format names and email
28171 address of committers, authors, and taggers, as represented in various
28172 places throughout the cgit interface.
28174 Defaults to @samp{""}.
28178 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
28179 Flag which, when set to @samp{#t}, will make cgit generate a HTML
28180 fragment suitable for embedding in other HTML pages.
28182 Defaults to @samp{#f}.
28186 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
28187 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
28188 commit history graph to the left of the commit messages in the
28189 repository log page.
28191 Defaults to @samp{#f}.
28195 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
28196 Flag which, when set to @samp{#t}, allows all filter settings to be
28197 overridden in repository-specific cgitrc files.
28199 Defaults to @samp{#f}.
28203 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
28204 Flag which, when set to @samp{#t}, allows users to follow a file in the
28207 Defaults to @samp{#f}.
28211 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
28212 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
28215 Defaults to @samp{#t}.
28219 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
28220 Flag which, when set to @samp{#t}, will make cgit generate extra links
28221 "summary", "commit", "tree" for each repo in the repository index.
28223 Defaults to @samp{#f}.
28227 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
28228 Flag which, when set to @samp{#t}, will make cgit display the owner of
28229 each repo in the repository index.
28231 Defaults to @samp{#t}.
28235 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
28236 Flag which, when set to @samp{#t}, will make cgit print the number of
28237 modified files for each commit on the repository log page.
28239 Defaults to @samp{#f}.
28243 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
28244 Flag which, when set to @samp{#t}, will make cgit print the number of
28245 added and removed lines for each commit on the repository log page.
28247 Defaults to @samp{#f}.
28251 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
28252 Flag which, when set to @code{#t}, will make cgit display remote
28253 branches in the summary and refs views.
28255 Defaults to @samp{#f}.
28259 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
28260 Flag which, when set to @code{1}, will make cgit use the subject of the
28261 parent commit as link text when generating links to parent commits in
28264 Defaults to @samp{#f}.
28268 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
28269 Flag which, when set to @samp{#t}, will make cgit use the subject of the
28270 parent commit as link text when generating links to parent commits in
28273 Defaults to @samp{#f}.
28277 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
28278 Flag which, when set to @samp{#t}, will make cgit generate linenumber
28279 links for plaintext blobs printed in the tree view.
28281 Defaults to @samp{#t}.
28285 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
28286 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
28287 set any repo specific settings.
28289 Defaults to @samp{#f}.
28293 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
28294 URL used as link to a shortcut icon for cgit.
28296 Defaults to @samp{"/favicon.ico"}.
28300 @deftypevr {@code{cgit-configuration} parameter} string footer
28301 The content of the file specified with this option will be included
28302 verbatim at the bottom of all pages (i.e.@: it replaces the standard
28303 "generated by..."@: message).
28305 Defaults to @samp{""}.
28309 @deftypevr {@code{cgit-configuration} parameter} string head-include
28310 The content of the file specified with this option will be included
28311 verbatim in the HTML HEAD section on all pages.
28313 Defaults to @samp{""}.
28317 @deftypevr {@code{cgit-configuration} parameter} string header
28318 The content of the file specified with this option will be included
28319 verbatim at the top of all pages.
28321 Defaults to @samp{""}.
28325 @deftypevr {@code{cgit-configuration} parameter} file-object include
28326 Name of a configfile to include before the rest of the current config-
28329 Defaults to @samp{""}.
28333 @deftypevr {@code{cgit-configuration} parameter} string index-header
28334 The content of the file specified with this option will be included
28335 verbatim above the repository index.
28337 Defaults to @samp{""}.
28341 @deftypevr {@code{cgit-configuration} parameter} string index-info
28342 The content of the file specified with this option will be included
28343 verbatim below the heading on the repository index page.
28345 Defaults to @samp{""}.
28349 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
28350 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
28351 in the servers timezone.
28353 Defaults to @samp{#f}.
28357 @deftypevr {@code{cgit-configuration} parameter} file-object logo
28358 URL which specifies the source of an image which will be used as a logo
28361 Defaults to @samp{"/share/cgit/cgit.png"}.
28365 @deftypevr {@code{cgit-configuration} parameter} string logo-link
28366 URL loaded when clicking on the cgit logo image.
28368 Defaults to @samp{""}.
28372 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
28373 Command which will be invoked to format the Owner column of the main
28376 Defaults to @samp{""}.
28380 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
28381 Number of items to display in atom feeds view.
28383 Defaults to @samp{10}.
28387 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
28388 Number of entries to list per page in "log" view.
28390 Defaults to @samp{50}.
28394 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
28395 Number of commit message characters to display in "log" view.
28397 Defaults to @samp{80}.
28401 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
28402 Specifies the number of entries to list per page on the repository index
28405 Defaults to @samp{50}.
28409 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
28410 Specifies the maximum number of repo description characters to display
28411 on the repository index page.
28413 Defaults to @samp{80}.
28417 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
28418 Specifies the maximum size of a blob to display HTML for in KBytes.
28420 Defaults to @samp{0}.
28424 @deftypevr {@code{cgit-configuration} parameter} string max-stats
28425 Maximum statistics period. Valid values are @samp{week},@samp{month},
28426 @samp{quarter} and @samp{year}.
28428 Defaults to @samp{""}.
28432 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
28433 Mimetype for the specified filename extension.
28435 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
28436 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
28437 "image/png") (svg "image/svg+xml"))}.
28441 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
28442 Specifies the file to use for automatic mimetype lookup.
28444 Defaults to @samp{""}.
28448 @deftypevr {@code{cgit-configuration} parameter} string module-link
28449 Text which will be used as the formatstring for a hyperlink when a
28450 submodule is printed in a directory listing.
28452 Defaults to @samp{""}.
28456 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
28457 If set to the value @samp{#t} caching will be disabled.
28459 Defaults to @samp{#f}.
28463 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
28464 If set to @samp{#t} showing full author email addresses will be
28467 Defaults to @samp{#f}.
28471 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
28472 Flag which, when set to @samp{#t}, will make cgit omit the standard
28473 header on all pages.
28475 Defaults to @samp{#f}.
28479 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
28480 A list of subdirectories inside of @code{repository-directory}, relative
28481 to it, that should loaded as Git repositories. An empty list means that
28482 all subdirectories will be loaded.
28484 Defaults to @samp{()}.
28488 @deftypevr {@code{cgit-configuration} parameter} file-object readme
28489 Text which will be used as default value for @code{cgit-repo-readme}.
28491 Defaults to @samp{""}.
28495 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
28496 If set to @code{#t} and @code{repository-directory} is enabled, if any
28497 repositories are found with a suffix of @code{.git}, this suffix will be
28498 removed for the URL and name.
28500 Defaults to @samp{#f}.
28504 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
28505 Maximum number of files to consider when detecting renames.
28507 Defaults to @samp{-1}.
28511 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
28512 The way in which repositories in each section are sorted.
28514 Defaults to @samp{""}.
28518 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
28519 Text used as content for the @code{robots} meta-tag.
28521 Defaults to @samp{("noindex" "nofollow")}.
28525 @deftypevr {@code{cgit-configuration} parameter} string root-desc
28526 Text printed below the heading on the repository index page.
28528 Defaults to @samp{"a fast webinterface for the git dscm"}.
28532 @deftypevr {@code{cgit-configuration} parameter} string root-readme
28533 The content of the file specified with this option will be included
28534 verbatim below the ``about'' link on the repository index page.
28536 Defaults to @samp{""}.
28540 @deftypevr {@code{cgit-configuration} parameter} string root-title
28541 Text printed as heading on the repository index page.
28543 Defaults to @samp{""}.
28547 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
28548 If set to @samp{#t} and repository-directory is enabled,
28549 repository-directory will recurse into directories whose name starts
28550 with a period. Otherwise, repository-directory will stay away from such
28551 directories, considered as ``hidden''. Note that this does not apply to
28552 the @file{.git} directory in non-bare repos.
28554 Defaults to @samp{#f}.
28558 @deftypevr {@code{cgit-configuration} parameter} list snapshots
28559 Text which specifies the default set of snapshot formats that cgit
28560 generates links for.
28562 Defaults to @samp{()}.
28566 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
28567 Name of the directory to scan for repositories (represents
28570 Defaults to @samp{"/srv/git"}.
28574 @deftypevr {@code{cgit-configuration} parameter} string section
28575 The name of the current repository section - all repositories defined
28576 after this option will inherit the current section name.
28578 Defaults to @samp{""}.
28582 @deftypevr {@code{cgit-configuration} parameter} string section-sort
28583 Flag which, when set to @samp{1}, will sort the sections on the
28584 repository listing by name.
28586 Defaults to @samp{""}.
28590 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
28591 A number which, if defined prior to repository-directory, specifies how
28592 many path elements from each repo path to use as a default section name.
28594 Defaults to @samp{0}.
28598 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
28599 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
28602 Defaults to @samp{#f}.
28606 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
28607 Specifies a command which will be invoked to format plaintext blobs in
28610 Defaults to @samp{""}.
28614 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
28615 Specifies the number of branches to display in the repository ``summary''
28618 Defaults to @samp{10}.
28622 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
28623 Specifies the number of log entries to display in the repository
28626 Defaults to @samp{10}.
28630 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
28631 Specifies the number of tags to display in the repository ``summary''
28634 Defaults to @samp{10}.
28638 @deftypevr {@code{cgit-configuration} parameter} string strict-export
28639 Filename which, if specified, needs to be present within the repository
28640 for cgit to allow access to that repository.
28642 Defaults to @samp{""}.
28646 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
28647 URL which, if specified, will be used as root for all cgit links.
28649 Defaults to @samp{"/"}.
28653 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
28654 A list of @dfn{cgit-repo} records to use with config.
28656 Defaults to @samp{()}.
28658 Available @code{repository-cgit-configuration} fields are:
28660 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
28661 A mask of snapshot formats for this repo that cgit generates links for,
28662 restricted by the global @code{snapshots} setting.
28664 Defaults to @samp{()}.
28668 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
28669 Override the default @code{source-filter}.
28671 Defaults to @samp{""}.
28675 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
28676 The relative URL used to access the repository.
28678 Defaults to @samp{""}.
28682 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
28683 Override the default @code{about-filter}.
28685 Defaults to @samp{""}.
28689 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
28690 Flag which, when set to @samp{age}, enables date ordering in the branch
28691 ref list, and when set to @samp{name} enables ordering by branch name.
28693 Defaults to @samp{""}.
28697 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
28698 A list of URLs which can be used to clone repo.
28700 Defaults to @samp{()}.
28704 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
28705 Override the default @code{commit-filter}.
28707 Defaults to @samp{""}.
28711 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
28712 Flag which, when set to @samp{date}, enables strict date ordering in the
28713 commit log, and when set to @samp{topo} enables strict topological
28716 Defaults to @samp{""}.
28720 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
28721 The name of the default branch for this repository. If no such branch
28722 exists in the repository, the first branch name (when sorted) is used as
28723 default instead. By default branch pointed to by HEAD, or ``master'' if
28724 there is no suitable HEAD.
28726 Defaults to @samp{""}.
28730 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
28731 The value to show as repository description.
28733 Defaults to @samp{""}.
28737 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
28738 The value to show as repository homepage.
28740 Defaults to @samp{""}.
28744 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
28745 Override the default @code{email-filter}.
28747 Defaults to @samp{""}.
28751 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
28752 A flag which can be used to disable the global setting
28753 @code{enable-commit-graph?}.
28755 Defaults to @samp{disabled}.
28759 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
28760 A flag which can be used to disable the global setting
28761 @code{enable-log-filecount?}.
28763 Defaults to @samp{disabled}.
28767 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
28768 A flag which can be used to disable the global setting
28769 @code{enable-log-linecount?}.
28771 Defaults to @samp{disabled}.
28775 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
28776 Flag which, when set to @code{#t}, will make cgit display remote
28777 branches in the summary and refs views.
28779 Defaults to @samp{disabled}.
28783 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
28784 A flag which can be used to override the global setting
28785 @code{enable-subject-links?}.
28787 Defaults to @samp{disabled}.
28791 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
28792 A flag which can be used to override the global setting
28793 @code{enable-html-serving?}.
28795 Defaults to @samp{disabled}.
28799 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
28800 Flag which, when set to @code{#t}, hides the repository from the
28803 Defaults to @samp{#f}.
28807 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
28808 Flag which, when set to @samp{#t}, ignores the repository.
28810 Defaults to @samp{#f}.
28814 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
28815 URL which specifies the source of an image which will be used as a logo
28816 on this repo’s pages.
28818 Defaults to @samp{""}.
28822 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
28823 URL loaded when clicking on the cgit logo image.
28825 Defaults to @samp{""}.
28829 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
28830 Override the default @code{owner-filter}.
28832 Defaults to @samp{""}.
28836 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
28837 Text which will be used as the formatstring for a hyperlink when a
28838 submodule is printed in a directory listing. The arguments for the
28839 formatstring are the path and SHA1 of the submodule commit.
28841 Defaults to @samp{""}.
28845 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
28846 Text which will be used as the formatstring for a hyperlink when a
28847 submodule with the specified subdirectory path is printed in a directory
28850 Defaults to @samp{()}.
28854 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
28855 Override the default maximum statistics period.
28857 Defaults to @samp{""}.
28861 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
28862 The value to show as repository name.
28864 Defaults to @samp{""}.
28868 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
28869 A value used to identify the owner of the repository.
28871 Defaults to @samp{""}.
28875 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
28876 An absolute path to the repository directory.
28878 Defaults to @samp{""}.
28882 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
28883 A path (relative to repo) which specifies a file to include verbatim as
28884 the ``About'' page for this repo.
28886 Defaults to @samp{""}.
28890 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
28891 The name of the current repository section - all repositories defined
28892 after this option will inherit the current section name.
28894 Defaults to @samp{""}.
28898 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
28899 Extra options will be appended to cgitrc file.
28901 Defaults to @samp{()}.
28907 @deftypevr {@code{cgit-configuration} parameter} list extra-options
28908 Extra options will be appended to cgitrc file.
28910 Defaults to @samp{()}.
28915 @c %end of fragment
28917 However, it could be that you just want to get a @code{cgitrc} up and
28918 running. In that case, you can pass an @code{opaque-cgit-configuration}
28919 as a record to @code{cgit-service-type}. As its name indicates, an
28920 opaque configuration does not have easy reflective capabilities.
28922 Available @code{opaque-cgit-configuration} fields are:
28924 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
28928 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
28929 The contents of the @code{cgitrc}, as a string.
28932 For example, if your @code{cgitrc} is just the empty string, you
28933 could instantiate a cgit service like this:
28936 (service cgit-service-type
28937 (opaque-cgit-configuration
28941 @subsubheading Gitolite Service
28943 @cindex Gitolite service
28944 @cindex Git, hosting
28945 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
28946 repositories on a central server.
28948 Gitolite can handle multiple repositories and users, and supports flexible
28949 configuration of the permissions for the users on the repositories.
28951 The following example will configure Gitolite using the default @code{git}
28952 user, and the provided SSH public key.
28955 (service gitolite-service-type
28956 (gitolite-configuration
28957 (admin-pubkey (plain-file
28959 "ssh-rsa AAAA... guix@@example.com"))))
28962 Gitolite is configured through a special admin repository which you can clone,
28963 for example, if you setup Gitolite on @code{example.com}, you would run the
28964 following command to clone the admin repository.
28967 git clone git@@example.com:gitolite-admin
28970 When the Gitolite service is activated, the provided @code{admin-pubkey} will
28971 be inserted in to the @file{keydir} directory in the gitolite-admin
28972 repository. If this results in a change in the repository, it will be
28973 committed using the message ``gitolite setup by GNU Guix''.
28975 @deftp {Data Type} gitolite-configuration
28976 Data type representing the configuration for @code{gitolite-service-type}.
28979 @item @code{package} (default: @var{gitolite})
28980 Gitolite package to use.
28982 @item @code{user} (default: @var{git})
28983 User to use for Gitolite. This will be user that you use when accessing
28986 @item @code{group} (default: @var{git})
28987 Group to use for Gitolite.
28989 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
28990 Directory in which to store the Gitolite configuration and repositories.
28992 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
28993 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
28994 representing the configuration for Gitolite.
28996 @item @code{admin-pubkey} (default: @var{#f})
28997 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
28998 setup Gitolite. This will be inserted in to the @file{keydir} directory
28999 within the gitolite-admin repository.
29001 To specify the SSH key as a string, use the @code{plain-file} function.
29004 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
29010 @deftp {Data Type} gitolite-rc-file
29011 Data type representing the Gitolite RC file.
29014 @item @code{umask} (default: @code{#o0077})
29015 This controls the permissions Gitolite sets on the repositories and their
29018 A value like @code{#o0027} will give read access to the group used by Gitolite
29019 (by default: @code{git}). This is necessary when using Gitolite with software
29020 like cgit or gitweb.
29022 @item @code{git-config-keys} (default: @code{""})
29023 Gitolite allows you to set git config values using the @samp{config} keyword. This
29024 setting allows control over the config keys to accept.
29026 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
29027 Set the role names allowed to be used by users running the perms command.
29029 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
29030 This setting controls the commands and features to enable within Gitolite.
29036 @node Game Services
29037 @subsection Game Services
29039 @subsubheading The Battle for Wesnoth Service
29041 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
29042 based tactical strategy game, with several single player campaigns, and
29043 multiplayer games (both networked and local).
29045 @defvar {Scheme Variable} wesnothd-service-type
29046 Service type for the wesnothd service. Its value must be a
29047 @code{wesnothd-configuration} object. To run wesnothd in the default
29048 configuration, instantiate it as:
29051 (service wesnothd-service-type)
29055 @deftp {Data Type} wesnothd-configuration
29056 Data type representing the configuration of @command{wesnothd}.
29059 @item @code{package} (default: @code{wesnoth-server})
29060 The wesnoth server package to use.
29062 @item @code{port} (default: @code{15000})
29063 The port to bind the server to.
29068 @node PAM Mount Service
29069 @subsection PAM Mount Service
29072 The @code{(gnu services pam-mount)} module provides a service allowing
29073 users to mount volumes when they log in. It should be able to mount any
29074 volume format supported by the system.
29076 @defvar {Scheme Variable} pam-mount-service-type
29077 Service type for PAM Mount support.
29080 @deftp {Data Type} pam-mount-configuration
29081 Data type representing the configuration of PAM Mount.
29083 It takes the following parameters:
29087 The configuration rules that will be used to generate
29088 @file{/etc/security/pam_mount.conf.xml}.
29090 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
29091 Guile Reference Manual}), and the default ones don't mount anything for
29095 `((debug (@@ (enable "0")))
29096 (mntoptions (@@ (allow ,(string-join
29097 '("nosuid" "nodev" "loop"
29098 "encryption" "fsck" "nonempty"
29099 "allow_root" "allow_other")
29101 (mntoptions (@@ (require "nosuid,nodev")))
29102 (logout (@@ (wait "0")
29106 (mkmountpoint (@@ (enable "1")
29110 Some @code{volume} elements must be added to automatically mount volumes
29111 at login. Here's an example allowing the user @code{alice} to mount her
29112 encrypted @env{HOME} directory and allowing the user @code{bob} to mount
29113 the partition where he stores his data:
29116 (define pam-mount-rules
29117 `((debug (@@ (enable "0")))
29118 (volume (@@ (user "alice")
29121 (mountpoint "/home/alice")))
29122 (volume (@@ (user "bob")
29125 (mountpoint "/home/bob/data")
29126 (options "defaults,autodefrag,compress")))
29127 (mntoptions (@@ (allow ,(string-join
29128 '("nosuid" "nodev" "loop"
29129 "encryption" "fsck" "nonempty"
29130 "allow_root" "allow_other")
29132 (mntoptions (@@ (require "nosuid,nodev")))
29133 (logout (@@ (wait "0")
29137 (mkmountpoint (@@ (enable "1")
29138 (remove "true")))))
29140 (service pam-mount-service-type
29141 (pam-mount-configuration
29142 (rules pam-mount-rules)))
29145 The complete list of possible options can be found in the man page for
29146 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
29151 @node Guix Services
29152 @subsection Guix Services
29154 @subsubheading Guix Build Coordinator
29155 The @uref{https://git.cbaines.net/guix/build-coordinator/,Guix Build
29156 Coordinator} aids in distributing derivation builds among machines
29157 running an @dfn{agent}. The build daemon is still used to build the
29158 derivations, but the Guix Build Coordinator manages allocating builds
29159 and working with the results.
29162 This service is considered experimental. Configuration options may be
29163 changed in a backwards-incompatible manner, and not all features have
29164 been thorougly tested.
29167 The Guix Build Coordinator consists of one @dfn{coordinator}, and one or
29168 more connected @dfn{agent} processes. The coordinator process handles
29169 clients submitting builds, and allocating builds to agents. The agent
29170 processes talk to a build daemon to actually perform the builds, then
29171 send the results back to the coordinator.
29173 There is a script to run the coordinator component of the Guix Build
29174 Coordinator, but the Guix service uses a custom Guile script instead, to
29175 provide better integration with G-expressions used in the configuration.
29177 @defvar {Scheme Variable} guix-build-coordinator-service-type
29178 Service type for the Guix Build Coordinator. Its value must be a
29179 @code{guix-build-coordinator-configuration} object.
29182 @deftp {Data Type} guix-build-coordinator-configuration
29183 Data type representing the configuration of the Guix Build Coordinator.
29186 @item @code{package} (default: @code{guix-build-coordinator})
29187 The Guix Build Coordinator package to use.
29189 @item @code{user} (default: @code{"guix-build-coordinator"})
29190 The system user to run the service as.
29192 @item @code{group} (default: @code{"guix-build-coordinator"})
29193 The system group to run the service as.
29195 @item @code{database-uri-string} (default: @code{"sqlite:///var/lib/guix-build-coordinator/guix_build_coordinator.db"})
29196 The URI to use for the database.
29198 @item @code{agent-communication-uri} (default: @code{"http://0.0.0.0:8745"})
29199 The URI describing how to listen to requests from agent processes.
29201 @item @code{client-communication-uri} (default: @code{"http://127.0.0.1:8746"})
29202 The URI describing how to listen to requests from clients. The client
29203 API allows submitting builds and currently isn't authenticated, so take
29204 care when configuring this value.
29206 @item @code{allocation-strategy} (default: @code{#~basic-build-allocation-strategy})
29207 A G-expression for the allocation strategy to be used. This is a
29208 procedure that takes the datastore as an argument and populates the
29209 allocation plan in the database.
29211 @item @code{hooks} (default: @var{'()})
29212 An association list of hooks. These provide a way to execute arbitrary
29213 code upon certain events, like a build result being processed.
29215 @item @code{guile} (default: @code{guile-3.0-latest})
29216 The Guile package with which to run the Guix Build Coordinator.
29221 @defvar {Scheme Variable} guix-build-coordinator-agent-service-type
29222 Service type for a Guix Build Coordinator agent. Its value must be a
29223 @code{guix-build-coordinator-agent-configuration} object.
29226 @deftp {Data Type} guix-build-coordinator-agent-configuration
29227 Data type representing the configuration a Guix Build Coordinator agent.
29230 @item @code{package} (default: @code{guix-build-coordinator})
29231 The Guix Build Coordinator package to use.
29233 @item @code{user} (default: @code{"guix-build-coordinator-agent"})
29234 The system user to run the service as.
29236 @item @code{coordinator} (default: @code{"http://localhost:8745"})
29237 The URI to use when connecting to the coordinator.
29240 The UUID of the agent. This should be generated by the coordinator
29241 process, stored in the coordinator database, and used by the intended
29244 @item @code{password} (default: @code{#f})
29245 The password to use when connecting to the coordinator. A file to read
29246 the password from can also be specified, and this is more secure.
29248 @item @code{password-file} (default: @code{#f})
29249 A file containing the password to use when connecting to the
29252 @item @code{systems} (default: @code{#f})
29253 The systems for which this agent should fetch builds. The agent process
29254 will use the current system it's running on as the default.
29256 @item @code{max-parallel-builds} (default: @code{1})
29257 The number of builds to perform in parallel.
29259 @item @code{derivation-substitute-urls} (default: @code{#f})
29260 URLs from which to attempt to fetch substitutes for derivations, if the
29261 derivations aren't already available.
29263 @item @code{non-derivation-substitute-urls} (default: @code{#f})
29264 URLs from which to attempt to fetch substitutes for build inputs, if the
29265 input store items aren't already available.
29270 The Guix Build Coordinator package contains a script to query an
29271 instance of the Guix Data Service for derivations to build, and then
29272 submit builds for those derivations to the coordinator. The service
29273 type below assists in running this script. This is an additional tool
29274 that may be useful when building derivations contained within an
29275 instance of the Guix Data Service.
29277 @defvar {Scheme Variable} guix-build-coordinator-queue-builds-service-type
29278 Service type for the
29279 guix-build-coordinator-queue-builds-from-guix-data-service script. Its
29280 value must be a @code{guix-build-coordinator-queue-builds-configuration}
29284 @deftp {Data Type} guix-build-coordinator-queue-builds-configuration
29285 Data type representing the options to the queue builds from guix data
29289 @item @code{package} (default: @code{guix-build-coordinator})
29290 The Guix Build Coordinator package to use.
29292 @item @code{user} (default: @code{"guix-build-coordinator-queue-builds"})
29293 The system user to run the service as.
29295 @item @code{coordinator} (default: @code{"http://localhost:8745"})
29296 The URI to use when connecting to the coordinator.
29298 @item @code{systems} (default: @code{#f})
29299 The systems for which to fetch derivations to build.
29301 @item @code{systems-and-targets} (default: @code{#f})
29302 An association list of system and target pairs for which to fetch
29303 derivations to build.
29305 @item @code{guix-data-service} (default: @code{"https://data.guix.gnu.org"})
29306 The Guix Data Service instance from which to query to find out about
29307 derivations to build.
29309 @item @code{processed-commits-file} (default: @code{"/var/cache/guix-build-coordinator-queue-builds/processed-commits"})
29310 A file to record which commits have been processed, to avoid needlessly
29311 processing them again if the service is restarted.
29316 @subsubheading Guix Data Service
29317 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
29318 and provides data about GNU Guix. This includes information about
29319 packages, derivations and lint warnings.
29321 The data is stored in a PostgreSQL database, and available through a web
29324 @defvar {Scheme Variable} guix-data-service-type
29325 Service type for the Guix Data Service. Its value must be a
29326 @code{guix-data-service-configuration} object. The service optionally
29327 extends the getmail service, as the guix-commits mailing list is used to
29328 find out about changes in the Guix git repository.
29331 @deftp {Data Type} guix-data-service-configuration
29332 Data type representing the configuration of the Guix Data Service.
29335 @item @code{package} (default: @code{guix-data-service})
29336 The Guix Data Service package to use.
29338 @item @code{user} (default: @code{"guix-data-service"})
29339 The system user to run the service as.
29341 @item @code{group} (default: @code{"guix-data-service"})
29342 The system group to run the service as.
29344 @item @code{port} (default: @code{8765})
29345 The port to bind the web service to.
29347 @item @code{host} (default: @code{"127.0.0.1"})
29348 The host to bind the web service to.
29350 @item @code{getmail-idle-mailboxes} (default: @code{#f})
29351 If set, this is the list of mailboxes that the getmail service will be
29352 configured to listen to.
29354 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
29355 If set, this is the @code{getmail-retriever-configuration} object with
29356 which to configure getmail to fetch mail from the guix-commits mailing
29359 @item @code{extra-options} (default: @var{'()})
29360 Extra command line options for @code{guix-data-service}.
29362 @item @code{extra-process-jobs-options} (default: @var{'()})
29363 Extra command line options for @code{guix-data-service-process-jobs}.
29368 @node Linux Services
29369 @subsection Linux Services
29372 @cindex out of memory killer
29374 @cindex early out of memory daemon
29375 @subsubheading Early OOM Service
29377 @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
29378 Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
29379 space and provides a more responsive and configurable alternative to the
29380 in-kernel OOM killer. It is useful to prevent the system from becoming
29381 unresponsive when it runs out of memory.
29383 @deffn {Scheme Variable} earlyoom-service-type
29384 The service type for running @command{earlyoom}, the Early OOM daemon.
29385 Its value must be a @code{earlyoom-configuration} object, described
29386 below. The service can be instantiated in its default configuration
29390 (service earlyoom-service-type)
29394 @deftp {Data Type} earlyoom-configuration
29395 This is the configuration record for the @code{earlyoom-service-type}.
29398 @item @code{earlyoom} (default: @var{earlyoom})
29399 The Earlyoom package to use.
29401 @item @code{minimum-available-memory} (default: @code{10})
29402 The threshold for the minimum @emph{available} memory, in percentages.
29404 @item @code{minimum-free-swap} (default: @code{10})
29405 The threshold for the minimum free swap memory, in percentages.
29407 @item @code{prefer-regexp} (default: @code{#f})
29408 A regular expression (as a string) to match the names of the processes
29409 that should be preferably killed.
29411 @item @code{avoid-regexp} (default: @code{#f})
29412 A regular expression (as a string) to match the names of the processes
29413 that should @emph{not} be killed.
29415 @item @code{memory-report-interval} (default: @code{0})
29416 The interval in seconds at which a memory report is printed. It is
29417 disabled by default.
29419 @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
29420 A boolean indicating whether the positive adjustments set in
29421 @file{/proc/*/oom_score_adj} should be ignored.
29423 @item @code{show-debug-messages?} (default: @code{#f})
29424 A boolean indicating whether debug messages should be printed. The logs
29425 are saved at @file{/var/log/earlyoom.log}.
29427 @item @code{send-notification-command} (default: @code{#f})
29428 This can be used to provide a custom command used for sending
29434 @cindex kernel module loader
29435 @subsubheading Kernel Module Loader Service
29437 The kernel module loader service allows one to load loadable kernel
29438 modules at boot. This is especially useful for modules that don't
29439 autoload and need to be manually loaded, as it's the case with
29442 @deffn {Scheme Variable} kernel-module-loader-service-type
29443 The service type for loading loadable kernel modules at boot with
29444 @command{modprobe}. Its value must be a list of strings representing
29445 module names. For example loading the drivers provided by
29446 @code{ddcci-driver-linux}, in debugging mode by passing some module
29447 parameters, can be done as follow:
29450 (use-modules (gnu) (gnu services))
29451 (use-package-modules linux)
29452 (use-service-modules linux)
29454 (define ddcci-config
29455 (plain-file "ddcci.conf"
29456 "options ddcci dyndbg delay=120"))
29460 (services (cons* (service kernel-module-loader-service-type
29461 '("ddcci" "ddcci_backlight"))
29462 (simple-service 'ddcci-config etc-service-type
29463 (list `("modprobe.d/ddcci.conf"
29466 (kernel-loadable-modules (list ddcci-driver-linux)))
29471 @cindex compressed swap
29472 @cindex Compressed RAM-based block devices
29473 @subsubheading Zram Device Service
29475 The Zram device service provides a compressed swap device in system
29476 memory. The Linux Kernel documentation has more information about
29477 @uref{https://www.kernel.org/doc/html/latest/admin-guide/blockdev/zram.html,zram}
29480 @deffn {Scheme Variable} zram-device-service-type
29481 This service creates the zram block device, formats it as swap and
29482 enables it as a swap device. The service's value is a
29483 @code{zram-device-configuration} record.
29485 @deftp {Data Type} zram-device-configuration
29486 This is the data type representing the configuration for the zram-device
29490 @item @code{size} (default @code{"1G"})
29491 This is the amount of space you wish to provide for the zram device. It
29492 accepts a string and can be a number of bytes or use a suffix, eg.:
29493 @code{"512M"} or @code{1024000}.
29494 @item @code{compression-algorithm} (default @code{'lzo})
29495 This is the compression algorithm you wish to use. It is difficult to
29496 list all the possible compression options, but common ones supported by
29497 Guix's Linux Libre Kernel include @code{'lzo}, @code{'lz4} and @code{'zstd}.
29498 @item @code{memory-limit} (default @code{0})
29499 This is the maximum amount of memory which the zram device can use.
29500 Setting it to '0' disables the limit. While it is generally expected
29501 that compression will be 2:1, it is possible that uncompressable data
29502 can be written to swap and this is a method to limit how much memory can
29503 be used. It accepts a string and can be a number of bytes or use a
29504 suffix, eg.: @code{"2G"}.
29505 @item @code{priority} (default @code{-1})
29506 This is the priority of the swap device created from the zram device.
29507 @code{swapon} accepts values between -1 and 32767, with higher values
29508 indicating higher priority. Higher priority swap will generally be used
29515 @node Hurd Services
29516 @subsection Hurd Services
29518 @defvr {Scheme Variable} hurd-console-service-type
29519 This service starts the fancy @code{VGA} console client on the Hurd.
29521 The service's value is a @code{hurd-console-configuration} record.
29524 @deftp {Data Type} hurd-console-configuration
29525 This is the data type representing the configuration for the
29526 hurd-console-service.
29529 @item @code{hurd} (default: @var{hurd})
29530 The Hurd package to use.
29534 @defvr {Scheme Variable} hurd-getty-service-type
29535 This service starts a tty using the Hurd @code{getty} program.
29537 The service's value is a @code{hurd-getty-configuration} record.
29540 @deftp {Data Type} hurd-getty-configuration
29541 This is the data type representing the configuration for the
29542 hurd-getty-service.
29545 @item @code{hurd} (default: @var{hurd})
29546 The Hurd package to use.
29549 The name of the console this Getty runs on---e.g., @code{"tty1"}.
29551 @item @code{baud-rate} (default: @code{38400})
29552 An integer specifying the baud rate of the tty.
29557 @node Miscellaneous Services
29558 @subsection Miscellaneous Services
29560 @cindex fingerprint
29561 @subsubheading Fingerprint Service
29563 The @code{(gnu services authentication)} module provides a DBus service to
29564 read and identify fingerprints via a fingerprint sensor.
29566 @defvr {Scheme Variable} fprintd-service-type
29567 The service type for @command{fprintd}, which provides the fingerprint
29568 reading capability.
29571 (service fprintd-service-type)
29576 @subsubheading System Control Service
29578 The @code{(gnu services sysctl)} provides a service to configure kernel
29579 parameters at boot.
29581 @defvr {Scheme Variable} sysctl-service-type
29582 The service type for @command{sysctl}, which modifies kernel parameters
29583 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
29587 (service sysctl-service-type
29588 (sysctl-configuration
29589 (settings '(("net.ipv4.ip_forward" . "1")))))
29593 @deftp {Data Type} sysctl-configuration
29594 The data type representing the configuration of @command{sysctl}.
29597 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
29598 The @command{sysctl} executable to use.
29600 @item @code{settings} (default: @code{'()})
29601 An association list specifies kernel parameters and their values.
29606 @subsubheading PC/SC Smart Card Daemon Service
29608 The @code{(gnu services security-token)} module provides the following service
29609 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
29610 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
29611 manager that coordinates communications with smart card readers, smart cards
29612 and cryptographic tokens that are connected to the system.
29614 @defvr {Scheme Variable} pcscd-service-type
29615 Service type for the @command{pcscd} service. Its value must be a
29616 @code{pcscd-configuration} object. To run pcscd in the default
29617 configuration, instantiate it as:
29620 (service pcscd-service-type)
29624 @deftp {Data Type} pcscd-configuration
29625 The data type representing the configuration of @command{pcscd}.
29628 @item @code{pcsc-lite} (default: @code{pcsc-lite})
29629 The pcsc-lite package that provides pcscd.
29630 @item @code{usb-drivers} (default: @code{(list ccid)})
29631 List of packages that provide USB drivers to pcscd. Drivers are expected to be
29632 under @file{pcsc/drivers} in the store directory of the package.
29637 @subsubheading Lirc Service
29639 The @code{(gnu services lirc)} module provides the following service.
29641 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
29642 [#:device #f] [#:driver #f] [#:config-file #f] @
29643 [#:extra-options '()]
29644 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
29645 decodes infrared signals from remote controls.
29647 Optionally, @var{device}, @var{driver} and @var{config-file}
29648 (configuration file name) may be specified. See @command{lircd} manual
29651 Finally, @var{extra-options} is a list of additional command-line options
29652 passed to @command{lircd}.
29656 @subsubheading Spice Service
29658 The @code{(gnu services spice)} module provides the following service.
29660 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
29661 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
29662 that enables sharing the clipboard with a vm and setting the guest display
29663 resolution when the graphical console window resizes.
29666 @cindex inputattach
29667 @subsubheading inputattach Service
29669 @cindex tablet input, for Xorg
29670 @cindex touchscreen input, for Xorg
29671 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
29672 use input devices such as Wacom tablets, touchscreens, or joysticks with the
29673 Xorg display server.
29675 @deffn {Scheme Variable} inputattach-service-type
29676 Type of a service that runs @command{inputattach} on a device and
29677 dispatches events from it.
29680 @deftp {Data Type} inputattach-configuration
29682 @item @code{device-type} (default: @code{"wacom"})
29683 The type of device to connect to. Run @command{inputattach --help}, from the
29684 @code{inputattach} package, to see the list of supported device types.
29686 @item @code{device} (default: @code{"/dev/ttyS0"})
29687 The device file to connect to the device.
29689 @item @code{baud-rate} (default: @code{#f})
29690 Baud rate to use for the serial connection.
29691 Should be a number or @code{#f}.
29693 @item @code{log-file} (default: @code{#f})
29694 If true, this must be the name of a file to log messages to.
29698 @subsubheading Dictionary Service
29700 The @code{(gnu services dict)} module provides the following service:
29702 @defvr {Scheme Variable} dicod-service-type
29703 This is the type of the service that runs the @command{dicod} daemon, an
29704 implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
29707 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
29708 Return a service that runs the @command{dicod} daemon, an implementation
29709 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
29711 The optional @var{config} argument specifies the configuration for
29712 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
29713 default it serves the GNU Collaborative International Dictionary of English.
29715 You can add @command{open localhost} to your @file{~/.dico} file to make
29716 @code{localhost} the default server for @command{dico} client
29717 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
29720 @deftp {Data Type} dicod-configuration
29721 Data type representing the configuration of dicod.
29724 @item @code{dico} (default: @var{dico})
29725 Package object of the GNU Dico dictionary server.
29727 @item @code{interfaces} (default: @var{'("localhost")})
29728 This is the list of IP addresses and ports and possibly socket file
29729 names to listen to (@pxref{Server Settings, @code{listen} directive,,
29730 dico, GNU Dico Manual}).
29732 @item @code{handlers} (default: @var{'()})
29733 List of @code{<dicod-handler>} objects denoting handlers (module instances).
29735 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
29736 List of @code{<dicod-database>} objects denoting dictionaries to be served.
29740 @deftp {Data Type} dicod-handler
29741 Data type representing a dictionary handler (module instance).
29745 Name of the handler (module instance).
29747 @item @code{module} (default: @var{#f})
29748 Name of the dicod module of the handler (instance). If it is @code{#f},
29749 the module has the same name as the handler.
29750 (@pxref{Modules,,, dico, GNU Dico Manual}).
29752 @item @code{options}
29753 List of strings or gexps representing the arguments for the module handler
29757 @deftp {Data Type} dicod-database
29758 Data type representing a dictionary database.
29762 Name of the database, will be used in DICT commands.
29764 @item @code{handler}
29765 Name of the dicod handler (module instance) used by this database
29766 (@pxref{Handlers,,, dico, GNU Dico Manual}).
29768 @item @code{complex?} (default: @var{#f})
29769 Whether the database configuration complex. The complex configuration
29770 will need a corresponding @code{<dicod-handler>} object, otherwise not.
29772 @item @code{options}
29773 List of strings or gexps representing the arguments for the database
29774 (@pxref{Databases,,, dico, GNU Dico Manual}).
29778 @defvr {Scheme Variable} %dicod-database:gcide
29779 A @code{<dicod-database>} object serving the GNU Collaborative International
29780 Dictionary of English using the @code{gcide} package.
29783 The following is an example @code{dicod-service} configuration.
29786 (dicod-service #:config
29787 (dicod-configuration
29788 (handlers (list (dicod-handler
29792 (list #~(string-append "dbdir=" #$wordnet))))))
29793 (databases (list (dicod-database
29796 (handler "wordnet")
29797 (options '("database=wn")))
29798 %dicod-database:gcide))))
29802 @subsubheading Docker Service
29804 The @code{(gnu services docker)} module provides the following services.
29806 @defvr {Scheme Variable} docker-service-type
29808 This is the type of the service that runs @url{https://www.docker.com,Docker},
29809 a daemon that can execute application bundles (sometimes referred to as
29810 ``containers'') in isolated environments.
29814 @deftp {Data Type} docker-configuration
29815 This is the data type representing the configuration of Docker and Containerd.
29819 @item @code{package} (default: @code{docker})
29820 The Docker daemon package to use.
29822 @item @code{package} (default: @code{docker-cli})
29823 The Docker client package to use.
29825 @item @code{containerd} (default: @var{containerd})
29826 The Containerd package to use.
29828 @item @code{proxy} (default @var{docker-libnetwork-cmd-proxy})
29829 The Docker user-land networking proxy package to use.
29831 @item @code{enable-proxy?} (default @code{#t})
29832 Enable or disable the use of the Docker user-land networking proxy.
29834 @item @code{debug?} (default @code{#f})
29835 Enable or disable debug output.
29837 @item @code{enable-iptables?} (default @code{#t})
29838 Enable or disable the addition of iptables rules.
29843 @cindex Singularity, container service
29844 @defvr {Scheme Variable} singularity-service-type
29845 This is the type of the service that allows you to run
29846 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
29847 create and run application bundles (aka. ``containers''). The value for this
29848 service is the Singularity package to use.
29850 The service does not install a daemon; instead, it installs helper programs as
29851 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
29852 @command{singularity run} and similar commands.
29856 @subsubheading Auditd Service
29858 The @code{(gnu services auditd)} module provides the following service.
29860 @defvr {Scheme Variable} auditd-service-type
29862 This is the type of the service that runs
29863 @url{https://people.redhat.com/sgrubb/audit/,auditd},
29864 a daemon that tracks security-relevant information on your system.
29866 Examples of things that can be tracked:
29876 Failed login attempts
29883 @command{auditctl} from the @code{audit} package can be used in order
29884 to add or remove events to be tracked (until the next reboot).
29885 In order to permanently track events, put the command line arguments
29886 of auditctl into a file called @code{audit.rules} in the configuration
29887 directory (see below).
29888 @command{aureport} from the @code{audit} package can be used in order
29889 to view a report of all recorded events.
29890 The audit daemon by default logs into the file
29891 @file{/var/log/audit.log}.
29895 @deftp {Data Type} auditd-configuration
29896 This is the data type representing the configuration of auditd.
29900 @item @code{audit} (default: @code{audit})
29901 The audit package to use.
29903 @item @code{configuration-directory} (default: @code{%default-auditd-configuration-directory})
29904 The directory containing the configuration file for the audit package, which
29905 must be named @code{auditd.conf}, and optionally some audit rules to
29906 instantiate on startup.
29912 @subsubheading R-Shiny service
29914 The @code{(gnu services science)} module provides the following service.
29916 @defvr {Scheme Variable} rshiny-service-type
29918 This is a type of service which is used to run a webapp created with
29919 @code{r-shiny}. This service sets the @env{R_LIBS_USER} environment
29920 variable and runs the provided script to call @code{runApp}.
29922 @deftp {Data Type} rshiny-configuration
29923 This is the data type representing the configuration of rshiny.
29927 @item @code{package} (default: @code{r-shiny})
29928 The package to use.
29930 @item @code{binary} (defaunlt @code{"rshiny"})
29931 The name of the binary or shell script located at @code{package/bin/} to
29932 run when the service is run.
29934 The common way to create this file is as follows:
29938 (let* ((out (assoc-ref %outputs "out"))
29939 (targetdir (string-append out "/share/" ,name))
29940 (app (string-append out "/bin/" ,name))
29941 (Rbin (string-append (assoc-ref %build-inputs "r-min")
29944 (mkdir-p (string-append out "/bin"))
29945 (call-with-output-file app
29951 runApp(launch.browser=0, port=4202)~%\n"
29960 @subsubheading Nix service
29962 The @code{(gnu services nix)} module provides the following service.
29964 @defvr {Scheme Variable} nix-service-type
29966 This is the type of the service that runs build daemon of the
29967 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
29971 (use-modules (gnu))
29972 (use-service-modules nix)
29973 (use-package-modules package-management)
29977 (packages (append (list nix)
29980 (services (append (list (service nix-service-type))
29984 After @command{guix system reconfigure} configure Nix for your user:
29987 @item Add a Nix channel and update it. See
29988 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
29990 @item Create a symlink to your profile and activate Nix profile:
29994 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
29995 $ source /run/current-system/profile/etc/profile.d/nix.sh
30000 @deftp {Data Type} nix-configuration
30001 This data type represents the configuration of the Nix daemon.
30004 @item @code{nix} (default: @code{nix})
30005 The Nix package to use.
30007 @item @code{sandbox} (default: @code{#t})
30008 Specifies whether builds are sandboxed by default.
30010 @item @code{build-sandbox-items} (default: @code{'()})
30011 This is a list of strings or objects appended to the
30012 @code{build-sandbox-items} field of the configuration file.
30014 @item @code{extra-config} (default: @code{'()})
30015 This is a list of strings or objects appended to the configuration file.
30016 It is used to pass extra text to be added verbatim to the configuration
30019 @item @code{extra-options} (default: @code{'()})
30020 Extra command line options for @code{nix-service-type}.
30024 @node Setuid Programs
30025 @section Setuid Programs
30027 @cindex setuid programs
30028 Some programs need to run with ``root'' privileges, even when they are
30029 launched by unprivileged users. A notorious example is the
30030 @command{passwd} program, which users can run to change their
30031 password, and which needs to access the @file{/etc/passwd} and
30032 @file{/etc/shadow} files---something normally restricted to root, for
30033 obvious security reasons. To address that, these executables are
30034 @dfn{setuid-root}, meaning that they always run with root privileges
30035 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
30036 for more info about the setuid mechanism).
30038 The store itself @emph{cannot} contain setuid programs: that would be a
30039 security issue since any user on the system can write derivations that
30040 populate the store (@pxref{The Store}). Thus, a different mechanism is
30041 used: instead of changing the setuid bit directly on files that are in
30042 the store, we let the system administrator @emph{declare} which programs
30043 should be setuid root.
30045 The @code{setuid-programs} field of an @code{operating-system}
30046 declaration contains a list of G-expressions denoting the names of
30047 programs to be setuid-root (@pxref{Using the Configuration System}).
30048 For instance, the @command{passwd} program, which is part of the Shadow
30049 package, can be designated by this G-expression (@pxref{G-Expressions}):
30052 #~(string-append #$shadow "/bin/passwd")
30055 A default set of setuid programs is defined by the
30056 @code{%setuid-programs} variable of the @code{(gnu system)} module.
30058 @defvr {Scheme Variable} %setuid-programs
30059 A list of G-expressions denoting common programs that are setuid-root.
30061 The list includes commands such as @command{passwd}, @command{ping},
30062 @command{su}, and @command{sudo}.
30065 Under the hood, the actual setuid programs are created in the
30066 @file{/run/setuid-programs} directory at system activation time. The
30067 files in this directory refer to the ``real'' binaries, which are in the
30070 @node X.509 Certificates
30071 @section X.509 Certificates
30073 @cindex HTTPS, certificates
30074 @cindex X.509 certificates
30076 Web servers available over HTTPS (that is, HTTP over the transport-layer
30077 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
30078 that the client can then use to @emph{authenticate} the server. To do
30079 that, clients verify that the server's certificate is signed by a
30080 so-called @dfn{certificate authority} (CA). But to verify the CA's
30081 signature, clients must have first acquired the CA's certificate.
30083 Web browsers such as GNU@tie{}IceCat include their own set of CA
30084 certificates, such that they are able to verify CA signatures
30087 However, most other programs that can talk HTTPS---@command{wget},
30088 @command{git}, @command{w3m}, etc.---need to be told where CA
30089 certificates can be found.
30091 @cindex @code{nss-certs}
30092 In Guix, this is done by adding a package that provides certificates
30093 to the @code{packages} field of the @code{operating-system} declaration
30094 (@pxref{operating-system Reference}). Guix includes one such package,
30095 @code{nss-certs}, which is a set of CA certificates provided as part of
30096 Mozilla's Network Security Services.
30098 Note that it is @emph{not} part of @code{%base-packages}, so you need to
30099 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
30100 most applications and libraries look for certificates by default, points
30101 to the certificates installed globally.
30103 Unprivileged users, including users of Guix on a foreign distro,
30104 can also install their own certificate package in
30105 their profile. A number of environment variables need to be defined so
30106 that applications and libraries know where to find them. Namely, the
30107 OpenSSL library honors the @env{SSL_CERT_DIR} and @env{SSL_CERT_FILE}
30108 variables. Some applications add their own environment variables; for
30109 instance, the Git version control system honors the certificate bundle
30110 pointed to by the @env{GIT_SSL_CAINFO} environment variable. Thus, you
30111 would typically run something like:
30114 guix install nss-certs
30115 export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
30116 export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
30117 export GIT_SSL_CAINFO="$SSL_CERT_FILE"
30120 As another example, R requires the @env{CURL_CA_BUNDLE} environment
30121 variable to point to a certificate bundle, so you would have to run
30122 something like this:
30125 guix install nss-certs
30126 export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
30129 For other applications you may want to look up the required environment
30130 variable in the relevant documentation.
30133 @node Name Service Switch
30134 @section Name Service Switch
30136 @cindex name service switch
30138 The @code{(gnu system nss)} module provides bindings to the
30139 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
30140 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
30141 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
30142 extended with new ``name'' lookup methods for system databases, which
30143 includes host names, service names, user accounts, and more (@pxref{Name
30144 Service Switch, System Databases and Name Service Switch,, libc, The GNU
30145 C Library Reference Manual}).
30147 The NSS configuration specifies, for each system database, which lookup
30148 method is to be used, and how the various methods are chained
30149 together---for instance, under which circumstances NSS should try the
30150 next method in the list. The NSS configuration is given in the
30151 @code{name-service-switch} field of @code{operating-system} declarations
30152 (@pxref{operating-system Reference, @code{name-service-switch}}).
30155 @cindex .local, host name lookup
30156 As an example, the declaration below configures the NSS to use the
30157 @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
30158 back-end}, which supports host name lookups over multicast DNS (mDNS)
30159 for host names ending in @code{.local}:
30162 (name-service-switch
30163 (hosts (list %files ;first, check /etc/hosts
30165 ;; If the above did not succeed, try
30166 ;; with 'mdns_minimal'.
30168 (name "mdns_minimal")
30170 ;; 'mdns_minimal' is authoritative for
30171 ;; '.local'. When it returns "not found",
30172 ;; no need to try the next methods.
30173 (reaction (lookup-specification
30174 (not-found => return))))
30176 ;; Then fall back to DNS.
30180 ;; Finally, try with the "full" 'mdns'.
30185 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
30186 contains this configuration, so you will not have to type it if all you
30187 want is to have @code{.local} host lookup working.
30189 Note that, in this case, in addition to setting the
30190 @code{name-service-switch} of the @code{operating-system} declaration,
30191 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
30192 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
30193 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
30194 to the name service cache daemon (@pxref{Base Services,
30195 @code{nscd-service}}).
30197 For convenience, the following variables provide typical NSS
30200 @defvr {Scheme Variable} %default-nss
30201 This is the default name service switch configuration, a
30202 @code{name-service-switch} object.
30205 @defvr {Scheme Variable} %mdns-host-lookup-nss
30206 This is the name service switch configuration with support for host name
30207 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
30210 The reference for name service switch configuration is given below. It
30211 is a direct mapping of the configuration file format of the C library , so
30212 please refer to the C library manual for more information (@pxref{NSS
30213 Configuration File,,, libc, The GNU C Library Reference Manual}).
30214 Compared to the configuration file format of libc NSS, it has the advantage
30215 not only of adding this warm parenthetic feel that we like, but also
30216 static checks: you will know about syntax errors and typos as soon as you
30217 run @command{guix system}.
30219 @deftp {Data Type} name-service-switch
30221 This is the data type representation the configuration of libc's name
30222 service switch (NSS). Each field below represents one of the supported
30239 The system databases handled by the NSS. Each of these fields must be a
30240 list of @code{<name-service>} objects (see below).
30244 @deftp {Data Type} name-service
30246 This is the data type representing an actual name service and the
30247 associated lookup action.
30251 A string denoting the name service (@pxref{Services in the NSS
30252 configuration,,, libc, The GNU C Library Reference Manual}).
30254 Note that name services listed here must be visible to nscd. This is
30255 achieved by passing the @code{#:name-services} argument to
30256 @code{nscd-service} the list of packages providing the needed name
30257 services (@pxref{Base Services, @code{nscd-service}}).
30260 An action specified using the @code{lookup-specification} macro
30261 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
30262 Reference Manual}). For example:
30265 (lookup-specification (unavailable => continue)
30266 (success => return))
30271 @node Initial RAM Disk
30272 @section Initial RAM Disk
30275 @cindex initial RAM disk
30276 For bootstrapping purposes, the Linux-Libre kernel is passed an
30277 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
30278 root file system as well as an initialization script. The latter is
30279 responsible for mounting the real root file system, and for loading any
30280 kernel modules that may be needed to achieve that.
30282 The @code{initrd-modules} field of an @code{operating-system}
30283 declaration allows you to specify Linux-libre kernel modules that must
30284 be available in the initrd. In particular, this is where you would list
30285 modules needed to actually drive the hard disk where your root partition
30286 is---although the default value of @code{initrd-modules} should cover
30287 most use cases. For example, assuming you need the @code{megaraid_sas}
30288 module in addition to the default modules to be able to access your root
30289 file system, you would write:
30294 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
30297 @defvr {Scheme Variable} %base-initrd-modules
30298 This is the list of kernel modules included in the initrd by default.
30301 Furthermore, if you need lower-level customization, the @code{initrd}
30302 field of an @code{operating-system} declaration allows
30303 you to specify which initrd you would like to use. The @code{(gnu
30304 system linux-initrd)} module provides three ways to build an initrd: the
30305 high-level @code{base-initrd} procedure and the low-level
30306 @code{raw-initrd} and @code{expression->initrd} procedures.
30308 The @code{base-initrd} procedure is intended to cover most common uses.
30309 For example, if you want to add a bunch of kernel modules to be loaded
30310 at boot time, you can define the @code{initrd} field of the operating
30311 system declaration like this:
30314 (initrd (lambda (file-systems . rest)
30315 ;; Create a standard initrd but set up networking
30316 ;; with the parameters QEMU expects by default.
30317 (apply base-initrd file-systems
30318 #:qemu-networking? #t
30322 The @code{base-initrd} procedure also handles common use cases that
30323 involves using the system as a QEMU guest, or as a ``live'' system with
30324 volatile root file system.
30326 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
30327 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
30328 such as trying to guess which kernel modules and packages should be included
30329 to the initrd. An example use of @code{raw-initrd} is when a user has
30330 a custom Linux kernel configuration and default kernel modules included by
30331 @code{base-initrd} are not available.
30333 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
30334 honors several options passed on the Linux kernel command line
30335 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
30336 @code{-append} option of QEMU), notably:
30339 @item --load=@var{boot}
30340 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
30341 program, once it has mounted the root file system.
30343 Guix uses this option to yield control to a boot program that runs the
30344 service activation programs and then spawns the GNU@tie{}Shepherd, the
30345 initialization system.
30347 @item --root=@var{root}
30348 Mount @var{root} as the root file system. @var{root} can be a device
30349 name like @code{/dev/sda1}, a file system label, or a file system UUID.
30350 When unspecified, the device name from the root file system of the
30351 operating system declaration is used.
30353 @item --system=@var{system}
30354 Have @file{/run/booted-system} and @file{/run/current-system} point to
30357 @item modprobe.blacklist=@var{modules}@dots{}
30358 @cindex module, black-listing
30359 @cindex black list, of kernel modules
30360 Instruct the initial RAM disk as well as the @command{modprobe} command
30361 (from the kmod package) to refuse to load @var{modules}. @var{modules}
30362 must be a comma-separated list of module names---e.g.,
30363 @code{usbkbd,9pnet}.
30366 Start a read-eval-print loop (REPL) from the initial RAM disk before it
30367 tries to load kernel modules and to mount the root file system. Our
30368 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
30369 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
30370 Manual}, for more information on Guile's REPL.
30374 Now that you know all the features that initial RAM disks produced by
30375 @code{base-initrd} and @code{raw-initrd} provide,
30376 here is how to use it and customize it further.
30379 @cindex initial RAM disk
30380 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
30381 [#:linux-modules '()] [#:mapped-devices '()] @
30382 [#:keyboard-layout #f] @
30383 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
30384 Return a derivation that builds a raw initrd. @var{file-systems} is
30385 a list of file systems to be mounted by the initrd, possibly in addition to
30386 the root file system specified on the kernel command line via @option{--root}.
30387 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
30388 @var{mapped-devices} is a list of device mappings to realize before
30389 @var{file-systems} are mounted (@pxref{Mapped Devices}).
30390 @var{helper-packages} is a list of packages to be copied in the initrd. It may
30391 include @code{e2fsck/static} or other packages needed by the initrd to check
30392 the root file system.
30394 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
30395 the desired console keyboard layout. This is done before @var{mapped-devices}
30396 are set up and before @var{file-systems} are mounted such that, should the
30397 user need to enter a passphrase or use the REPL, this happens using the
30398 intended keyboard layout.
30400 When @var{qemu-networking?} is true, set up networking with the standard QEMU
30401 parameters. When @var{virtio?} is true, load additional modules so that the
30402 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
30404 When @var{volatile-root?} is true, the root file system is writable but any changes
30408 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
30409 [#:mapped-devices '()] [#:keyboard-layout #f] @
30410 [#:qemu-networking? #f] [#:volatile-root? #f] @
30411 [#:linux-modules '()]
30412 Return as a file-like object a generic initrd, with kernel
30413 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
30414 mounted by the initrd, possibly in addition to the root file system specified
30415 on the kernel command line via @option{--root}. @var{mapped-devices} is a list of device
30416 mappings to realize before @var{file-systems} are mounted.
30418 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
30419 the desired console keyboard layout. This is done before @var{mapped-devices}
30420 are set up and before @var{file-systems} are mounted such that, should the
30421 user need to enter a passphrase or use the REPL, this happens using the
30422 intended keyboard layout.
30424 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
30426 The initrd is automatically populated with all the kernel modules necessary
30427 for @var{file-systems} and for the given options. Additional kernel
30428 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
30429 loaded at boot time in the order in which they appear.
30432 Needless to say, the initrds we produce and use embed a
30433 statically-linked Guile, and the initialization program is a Guile
30434 program. That gives a lot of flexibility. The
30435 @code{expression->initrd} procedure builds such an initrd, given the
30436 program to run in that initrd.
30438 @deffn {Scheme Procedure} expression->initrd @var{exp} @
30439 [#:guile %guile-3.0-static-stripped] [#:name "guile-initrd"]
30440 Return as a file-like object a Linux initrd (a gzipped cpio archive)
30441 containing @var{guile} and that evaluates @var{exp}, a G-expression,
30442 upon booting. All the derivations referenced by @var{exp} are
30443 automatically copied to the initrd.
30446 @node Bootloader Configuration
30447 @section Bootloader Configuration
30450 @cindex boot loader
30452 The operating system supports multiple bootloaders. The bootloader is
30453 configured using @code{bootloader-configuration} declaration. All the
30454 fields of this structure are bootloader agnostic except for one field,
30455 @code{bootloader} that indicates the bootloader to be configured and
30458 Some of the bootloaders do not honor every field of
30459 @code{bootloader-configuration}. For instance, the extlinux
30460 bootloader does not support themes and thus ignores the @code{theme}
30463 @deftp {Data Type} bootloader-configuration
30464 The type of a bootloader configuration declaration.
30468 @item @code{bootloader}
30469 @cindex EFI, bootloader
30470 @cindex UEFI, bootloader
30471 @cindex BIOS, bootloader
30472 The bootloader to use, as a @code{bootloader} object. For now
30473 @code{grub-bootloader}, @code{grub-efi-bootloader},
30474 @code{grub-efi-netboot-bootloader}, @code{extlinux-bootloader} and
30475 @code{u-boot-bootloader} are supported.
30477 @cindex ARM, bootloaders
30478 @cindex AArch64, bootloaders
30479 Available bootloaders are described in @code{(gnu bootloader @dots{})}
30480 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
30481 of bootloaders for a wide range of ARM and AArch64 systems, using the
30482 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
30484 @vindex grub-efi-bootloader
30485 @code{grub-efi-bootloader} allows to boot on modern systems using the
30486 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
30487 use if the installation image contains a @file{/sys/firmware/efi} directory
30488 when you boot it on your system.
30490 @vindex grub-bootloader
30491 @code{grub-bootloader} allows you to boot in particular Intel-based machines
30492 in ``legacy'' BIOS mode.
30494 @vindex grub-efi-netboot-bootloader
30495 @code{grub-efi-netboot-bootloader} allows you to boot your system over network
30496 through TFTP. In combination with an NFS root file system this allows you to
30497 build a diskless Guix system.
30499 The installation of the @code{grub-efi-netboot-bootloader} generates the content
30500 of the TFTP root directory at @code{target}
30501 (@pxref{Bootloader Configuration, @code{target}}), to be served by a TFTP server.
30502 You may want to mount your TFTP server directory onto @code{target} to move the
30503 required files to the TFTP server automatically.
30505 If you plan to use an NFS root file system as well (actually if you mount the
30506 store from an NFS share), then the TFTP server needs to serve the file
30507 @file{/boot/grub/grub.cfg} and other files from the store (like GRUBs background
30508 image, the kernel (@pxref{operating-system Reference, @code{kernel}}) and the
30509 initrd (@pxref{operating-system Reference, @code{initrd}})), too. All these
30510 files from the store will be accessed by GRUB through TFTP with their normal
30511 store path, for example as
30512 @file{tftp://tftp-server/gnu/store/…-initrd/initrd.cpio.gz}.
30514 Two symlinks are created to make this possible. The first symlink is
30515 @code{target}@file{/efi/Guix/boot/grub/grub.cfg} pointing to
30516 @file{../../../boot/grub/grub.cfg},
30517 where @code{target} may be @file{/boot}. In this case the link is not leaving
30518 the served TFTP root directory, but otherwise it does. The second link is
30519 @code{target}@file{/gnu/store} and points to @file{../gnu/store}. This link
30520 is leaving the served TFTP root directory.
30522 The assumption behind all this is that you have an NFS server exporting the root
30523 file system for your Guix system, and additionally a TFTP server exporting your
30524 @code{target} directory—usually @file{/boot}—from that same root file system for
30525 your Guix system. In this constellation the symlinks will work.
30527 For other constellations you will have to program your own bootloader installer,
30528 which then takes care to make necessary files from the store accessible through
30529 TFTP, for example by copying them into the TFTP root directory at @code{target}.
30531 It is important to note that symlinks pointing outside the TFTP root directory
30532 may need to be allowed in the configuration of your TFTP server. Further the
30533 store link exposes the whole store through TFTP. Both points need to be
30534 considered carefully for security aspects.
30536 Beside the @code{grub-efi-netboot-bootloader}, the already mentioned TFTP and
30537 NFS servers, you also need a properly configured DHCP server to make the booting
30538 over netboot possible. For all this we can currently only recommend you to look
30539 for instructions about @acronym{PXE, Preboot eXecution Environment}.
30541 @item @code{target}
30542 This is a string denoting the target onto which to install the
30545 The interpretation depends on the bootloader in question. For
30546 @code{grub-bootloader}, for example, it should be a device name understood by
30547 the bootloader @command{installer} command, such as @code{/dev/sda} or
30548 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
30549 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
30550 system, usually @file{/boot/efi}. For @code{grub-efi-netboot-bootloader},
30551 @code{target} should be the mount point corresponding to the TFTP root
30552 directory of your TFTP server.
30554 @item @code{menu-entries} (default: @code{()})
30555 A possibly empty list of @code{menu-entry} objects (see below), denoting
30556 entries to appear in the bootloader menu, in addition to the current
30557 system entry and the entry pointing to previous system generations.
30559 @item @code{default-entry} (default: @code{0})
30560 The index of the default boot menu entry. Index 0 is for the entry of the
30563 @item @code{timeout} (default: @code{5})
30564 The number of seconds to wait for keyboard input before booting. Set to
30565 0 to boot immediately, and to -1 to wait indefinitely.
30567 @cindex keyboard layout, for the bootloader
30568 @item @code{keyboard-layout} (default: @code{#f})
30569 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
30570 layout, usually US@tie{}English (``qwerty'').
30572 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
30576 This option is currently ignored by bootloaders other than @code{grub} and
30580 @item @code{theme} (default: @var{#f})
30581 The bootloader theme object describing the theme to use. If no theme
30582 is provided, some bootloaders might use a default theme, that's true
30585 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
30586 The output terminals used for the bootloader boot menu, as a list of
30587 symbols. GRUB accepts the values: @code{console}, @code{serial},
30588 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
30589 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
30590 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
30591 configuration,,, grub,GNU GRUB manual}).
30593 @item @code{terminal-inputs} (default: @code{'()})
30594 The input terminals used for the bootloader boot menu, as a list of
30595 symbols. For GRUB, the default is the native platform terminal as
30596 determined at run-time. GRUB accepts the values: @code{console},
30597 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
30598 @code{usb_keyboard}. This field corresponds to the GRUB variable
30599 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
30602 @item @code{serial-unit} (default: @code{#f})
30603 The serial unit used by the bootloader, as an integer from 0 to 3.
30604 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
30605 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
30607 @item @code{serial-speed} (default: @code{#f})
30608 The speed of the serial interface, as an integer. For GRUB, the
30609 default value is chosen at run-time; currently GRUB chooses
30610 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
30617 Should you want to list additional boot menu entries @i{via} the
30618 @code{menu-entries} field above, you will need to create them with the
30619 @code{menu-entry} form. For example, imagine you want to be able to
30620 boot another distro (hard to imagine!), you can define a menu entry
30625 (label "The Other Distro")
30626 (linux "/boot/old/vmlinux-2.6.32")
30627 (linux-arguments '("root=/dev/sda2"))
30628 (initrd "/boot/old/initrd"))
30633 @deftp {Data Type} menu-entry
30634 The type of an entry in the bootloader menu.
30639 The label to show in the menu---e.g., @code{"GNU"}.
30641 @item @code{linux} (default: @code{#f})
30642 The Linux kernel image to boot, for example:
30645 (file-append linux-libre "/bzImage")
30648 For GRUB, it is also possible to specify a device explicitly in the
30649 file path using GRUB's device naming convention (@pxref{Naming
30650 convention,,, grub, GNU GRUB manual}), for example:
30653 "(hd0,msdos1)/boot/vmlinuz"
30656 If the device is specified explicitly as above, then the @code{device}
30657 field is ignored entirely.
30659 @item @code{linux-arguments} (default: @code{()})
30660 The list of extra Linux kernel command-line arguments---e.g.,
30661 @code{("console=ttyS0")}.
30663 @item @code{initrd} (default: @code{#f})
30664 A G-Expression or string denoting the file name of the initial RAM disk
30665 to use (@pxref{G-Expressions}).
30667 @item @code{device} (default: @code{#f})
30668 The device where the kernel and initrd are to be found---i.e., for GRUB,
30669 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
30671 This may be a file system label (a string), a file system UUID (a
30672 bytevector, @pxref{File Systems}), or @code{#f}, in which case
30673 the bootloader will search the device containing the file specified by
30674 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
30675 must @emph{not} be an OS device name such as @file{/dev/sda1}.
30677 @item @code{multiboot-kernel} (default: @code{#f})
30678 The kernel to boot in Multiboot-mode (@pxref{multiboot,,, grub, GNU GRUB
30679 manual}). When this field is set, a Multiboot menu-entry is generated.
30683 (file-append mach "/boot/gnumach")
30686 @item @code{multiboot-arguments} (default: @code{()})
30687 The list of extra command-line arguments for the multiboot-kernel.
30689 @item @code{multiboot-modules} (default: @code{()})
30690 The list of commands for loading Multiboot modules. For example:
30693 (list (list (file-append hurd "/hurd/ext2fs.static") "ext2fs"
30695 (list (file-append libc "/lib/ld.so.1") "exec"
30705 @c FIXME: Write documentation once it's stable.
30706 For now only GRUB has theme support. GRUB themes are created using
30707 the @code{grub-theme} form, which is not fully documented yet.
30709 @deftp {Data Type} grub-theme
30710 Data type representing the configuration of the GRUB theme.
30713 @item @code{gfxmode} (default: @code{'("auto")})
30714 The GRUB @code{gfxmode} to set (a list of screen resolution strings,
30715 @pxref{gfxmode,,, grub, GNU GRUB manual}).
30719 @deffn {Scheme Procedure} grub-theme
30720 Return the default GRUB theme used by the operating system if no
30721 @code{theme} field is specified in @code{bootloader-configuration}
30724 It comes with a fancy background image displaying the GNU and Guix
30728 For example, to override the default resolution, you may use something
30733 (bootloader-configuration
30736 (inherit (grub-theme))
30737 (gfxmode '("1024x786x32" "auto"))))))
30740 @node Invoking guix system
30741 @section Invoking @code{guix system}
30743 Once you have written an operating system declaration as seen in the
30744 previous section, it can be @dfn{instantiated} using the @command{guix
30745 system} command. The synopsis is:
30748 guix system @var{options}@dots{} @var{action} @var{file}
30751 @var{file} must be the name of a file containing an
30752 @code{operating-system} declaration. @var{action} specifies how the
30753 operating system is instantiated. Currently the following values are
30758 Display available service type definitions that match the given regular
30759 expressions, sorted by relevance:
30765 $ guix system search console
30766 name: console-fonts
30767 location: gnu/services/base.scm:806:2
30768 extends: shepherd-root
30769 description: Install the given fonts on the specified ttys (fonts are per
30770 + virtual console on GNU/Linux). The value of this service is a list of
30771 + tty/font pairs. The font can be the name of a font provided by the `kbd'
30772 + package or any valid argument to `setfont', as in this example:
30774 + '(("tty1" . "LatGrkCyr-8x16")
30775 + ("tty2" . (file-append
30777 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
30778 + ("tty3" . (file-append
30780 + "/share/consolefonts/ter-132n"))) ; for HDPI
30784 location: gnu/services/base.scm:1190:2
30785 extends: shepherd-root
30786 description: Provide console login using the `mingetty' program.
30790 location: gnu/services/base.scm:860:2
30792 description: Provide a console log-in service as specified by its
30793 + configuration value, a `login-configuration' object.
30799 As for @command{guix package --search}, the result is written in
30800 @code{recutils} format, which makes it easy to filter the output
30801 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
30804 Build the operating system described in @var{file}, activate it, and
30805 switch to it@footnote{This action (and the related actions
30806 @code{switch-generation} and @code{roll-back}) are usable only on
30807 systems already running Guix System.}.
30810 @c The paragraph below refers to the problem discussed at
30811 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
30812 It is highly recommended to run @command{guix pull} once before you run
30813 @command{guix system reconfigure} for the first time (@pxref{Invoking
30814 guix pull}). Failing to do that you would see an older version of Guix
30815 once @command{reconfigure} has completed.
30818 This effects all the configuration specified in @var{file}: user
30819 accounts, system services, global package list, setuid programs, etc.
30820 The command starts system services specified in @var{file} that are not
30821 currently running; if a service is currently running this command will
30822 arrange for it to be upgraded the next time it is stopped (e.g.@: by
30823 @code{herd stop X} or @code{herd restart X}).
30825 This command creates a new generation whose number is one greater than
30826 the current generation (as reported by @command{guix system
30827 list-generations}). If that generation already exists, it will be
30828 overwritten. This behavior mirrors that of @command{guix package}
30829 (@pxref{Invoking guix package}).
30831 It also adds a bootloader menu entry for the new OS configuration,
30832 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
30833 entries for older configurations to a submenu, allowing you to choose
30834 an older system generation at boot time should you need it.
30836 @cindex provenance tracking, of the operating system
30837 Upon completion, the new system is deployed under
30838 @file{/run/current-system}. This directory contains @dfn{provenance
30839 meta-data}: the list of channels in use (@pxref{Channels}) and
30840 @var{file} itself, when available. You can view it by running:
30843 guix system describe
30846 This information is useful should you later want to inspect how this
30847 particular generation was built. In fact, assuming @var{file} is
30848 self-contained, you can later rebuild generation @var{n} of your
30849 operating system with:
30852 guix time-machine \
30853 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
30854 system reconfigure \
30855 /var/guix/profiles/system-@var{n}-link/configuration.scm
30858 You can think of it as some sort of built-in version control! Your
30859 system is not just a binary artifact: @emph{it carries its own source}.
30860 @xref{Service Reference, @code{provenance-service-type}}, for more
30861 information on provenance tracking.
30863 By default, @command{reconfigure} @emph{prevents you from downgrading
30864 your system}, which could (re)introduce security vulnerabilities and
30865 also cause problems with ``stateful'' services such as database
30866 management systems. You can override that behavior by passing
30867 @option{--allow-downgrades}.
30869 @item switch-generation
30870 @cindex generations
30871 Switch to an existing system generation. This action atomically
30872 switches the system profile to the specified system generation. It
30873 also rearranges the system's existing bootloader menu entries. It
30874 makes the menu entry for the specified system generation the default,
30875 and it moves the entries for the other generations to a submenu, if
30876 supported by the bootloader being used. The next time the system
30877 boots, it will use the specified system generation.
30879 The bootloader itself is not being reinstalled when using this
30880 command. Thus, the installed bootloader is used with an updated
30881 configuration file.
30883 The target generation can be specified explicitly by its generation
30884 number. For example, the following invocation would switch to system
30888 guix system switch-generation 7
30891 The target generation can also be specified relative to the current
30892 generation with the form @code{+N} or @code{-N}, where @code{+3} means
30893 ``3 generations ahead of the current generation,'' and @code{-1} means
30894 ``1 generation prior to the current generation.'' When specifying a
30895 negative value such as @code{-1}, you must precede it with @code{--} to
30896 prevent it from being parsed as an option. For example:
30899 guix system switch-generation -- -1
30902 Currently, the effect of invoking this action is @emph{only} to switch
30903 the system profile to an existing generation and rearrange the
30904 bootloader menu entries. To actually start using the target system
30905 generation, you must reboot after running this action. In the future,
30906 it will be updated to do the same things as @command{reconfigure},
30907 like activating and deactivating services.
30909 This action will fail if the specified generation does not exist.
30912 @cindex rolling back
30913 Switch to the preceding system generation. The next time the system
30914 boots, it will use the preceding system generation. This is the inverse
30915 of @command{reconfigure}, and it is exactly the same as invoking
30916 @command{switch-generation} with an argument of @code{-1}.
30918 Currently, as with @command{switch-generation}, you must reboot after
30919 running this action to actually start using the preceding system
30922 @item delete-generations
30923 @cindex deleting system generations
30924 @cindex saving space
30925 Delete system generations, making them candidates for garbage collection
30926 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
30929 This works in the same way as @samp{guix package --delete-generations}
30930 (@pxref{Invoking guix package, @option{--delete-generations}}). With no
30931 arguments, all system generations but the current one are deleted:
30934 guix system delete-generations
30937 You can also select the generations you want to delete. The example below
30938 deletes all the system generations that are more than two month old:
30941 guix system delete-generations 2m
30944 Running this command automatically reinstalls the bootloader with an updated
30945 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
30946 longer lists the generations that have been deleted.
30949 Build the derivation of the operating system, which includes all the
30950 configuration files and programs needed to boot and run the system.
30951 This action does not actually install anything.
30954 Populate the given directory with all the files necessary to run the
30955 operating system specified in @var{file}. This is useful for first-time
30956 installations of Guix System. For instance:
30959 guix system init my-os-config.scm /mnt
30962 copies to @file{/mnt} all the store items required by the configuration
30963 specified in @file{my-os-config.scm}. This includes configuration
30964 files, packages, and so on. It also creates other essential files
30965 needed for the system to operate correctly---e.g., the @file{/etc},
30966 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
30968 This command also installs bootloader on the target specified in
30969 @file{my-os-config}, unless the @option{--no-bootloader} option was
30973 @cindex virtual machine
30975 @anchor{guix system vm}
30976 Build a virtual machine that contains the operating system declared in
30977 @var{file}, and return a script to run that virtual machine (VM).
30980 The @code{vm} action and others below
30981 can use KVM support in the Linux-libre kernel. Specifically, if the
30982 machine has hardware virtualization support, the corresponding
30983 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
30984 must exist and be readable and writable by the user and by the
30985 build users of the daemon (@pxref{Build Environment Setup}).
30988 Arguments given to the script are passed to QEMU as in the example
30989 below, which enables networking and requests 1@tie{}GiB of RAM for the
30993 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
30996 The VM shares its store with the host system.
30998 Additional file systems can be shared between the host and the VM using
30999 the @option{--share} and @option{--expose} command-line options: the former
31000 specifies a directory to be shared with write access, while the latter
31001 provides read-only access to the shared directory.
31003 The example below creates a VM in which the user's home directory is
31004 accessible read-only, and where the @file{/exchange} directory is a
31005 read-write mapping of @file{$HOME/tmp} on the host:
31008 guix system vm my-config.scm \
31009 --expose=$HOME --share=$HOME/tmp=/exchange
31012 On GNU/Linux, the default is to boot directly to the kernel; this has
31013 the advantage of requiring only a very tiny root disk image since the
31014 store of the host can then be mounted.
31016 The @option{--full-boot} option forces a complete boot sequence, starting
31017 with the bootloader. This requires more disk space since a root image
31018 containing at least the kernel, initrd, and bootloader data files must
31019 be created. The @option{--image-size} option can be used to specify the
31022 @cindex System images, creation in various formats
31023 @cindex Creating system images in various formats
31026 @itemx docker-image
31027 Return a virtual machine, disk image, or Docker image of the operating
31028 system declared in @var{file} that stands alone. By default,
31029 @command{guix system} estimates the size of the image needed to store
31030 the system, but you can use the @option{--image-size} option to specify
31031 a value. Docker images are built to contain exactly what they need, so
31032 the @option{--image-size} option is ignored in the case of
31033 @code{docker-image}.
31035 @cindex disk-image, creating disk images
31036 The @code{disk-image} command can produce various image types. The
31037 image type can be selected using the @option{--image-type} option. It
31038 defaults to @code{raw}. When its value is @code{iso9660}, the
31039 @option{--label} option can be used to specify a volume ID with
31040 @code{disk-image}. By default, the root file system of a disk image is
31041 mounted non-volatile; the @option{--volatile} option can be provided to
31042 make it volatile instead. When using @code{disk-image}, the bootloader
31043 installed on the generated image is taken from the provided
31044 @code{operating-system} definition. The following example demonstrates
31045 how to generate an image that uses the @code{grub-efi-bootloader}
31046 bootloader and boot it with QEMU:
31049 image=$(guix system disk-image --image-type=qcow2 \
31050 gnu/system/examples/lightweight-desktop.tmpl)
31051 cp $image /tmp/my-image.qcow2
31052 chmod +w /tmp/my-image.qcow2
31053 qemu-system-x86_64 -enable-kvm -hda /tmp/my-image.qcow2 -m 1000 \
31054 -bios $(guix build ovmf)/share/firmware/ovmf_x64.bin
31057 When using the @code{raw} image type, a raw disk image is produced; it
31058 can be copied as is to a USB stick, for instance. Assuming
31059 @code{/dev/sdc} is the device corresponding to a USB stick, one can copy
31060 the image to it using the following command:
31063 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc status=progress
31066 The @code{--list-image-types} command lists all the available image
31069 @cindex vm-image, creating virtual machine images
31070 When using @code{vm-image}, the returned image is in qcow2 format, which
31071 the QEMU emulator can efficiently use. @xref{Running Guix in a VM}, for
31072 more information on how to run the image in a virtual machine. The
31073 @code{grub-bootloader} bootloader is always used independently of what
31074 is declared in the @code{operating-system} file passed as argument.
31075 This is to make it easier to work with QEMU, which uses the SeaBIOS BIOS
31076 by default, expecting a bootloader to be installed in the Master Boot
31079 @cindex docker-image, creating docker images
31080 When using @code{docker-image}, a Docker image is produced. Guix builds
31081 the image from scratch, not from a pre-existing Docker base image. As a
31082 result, it contains @emph{exactly} what you define in the operating
31083 system configuration file. You can then load the image and launch a
31084 Docker container using commands like the following:
31087 image_id="`docker load < guix-system-docker-image.tar.gz`"
31088 container_id="`docker create $image_id`"
31089 docker start $container_id
31092 This command starts a new Docker container from the specified image. It
31093 will boot the Guix system in the usual manner, which means it will
31094 start any services you have defined in the operating system
31095 configuration. You can get an interactive shell running in the container
31096 using @command{docker exec}:
31099 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
31102 Depending on what you run in the Docker container, it
31103 may be necessary to give the container additional permissions. For
31104 example, if you intend to build software using Guix inside of the Docker
31105 container, you may need to pass the @option{--privileged} option to
31106 @code{docker create}.
31108 Last, the @option{--network} option applies to @command{guix system
31109 docker-image}: it produces an image where network is supposedly shared
31110 with the host, and thus without services like nscd or NetworkManager.
31113 Return a script to run the operating system declared in @var{file}
31114 within a container. Containers are a set of lightweight isolation
31115 mechanisms provided by the kernel Linux-libre. Containers are
31116 substantially less resource-demanding than full virtual machines since
31117 the kernel, shared objects, and other resources can be shared with the
31118 host system; this also means they provide thinner isolation.
31120 Currently, the script must be run as root in order to support more than
31121 a single user and group. The container shares its store with the host
31124 As with the @code{vm} action (@pxref{guix system vm}), additional file
31125 systems to be shared between the host and container can be specified
31126 using the @option{--share} and @option{--expose} options:
31129 guix system container my-config.scm \
31130 --expose=$HOME --share=$HOME/tmp=/exchange
31134 This option requires Linux-libre 3.19 or newer.
31139 @var{options} can contain any of the common build options (@pxref{Common
31140 Build Options}). In addition, @var{options} can contain one of the
31144 @item --expression=@var{expr}
31145 @itemx -e @var{expr}
31146 Consider the operating-system @var{expr} evaluates to.
31147 This is an alternative to specifying a file which evaluates to an
31149 This is used to generate the Guix system installer @pxref{Building the
31150 Installation Image}).
31152 @item --system=@var{system}
31153 @itemx -s @var{system}
31154 Attempt to build for @var{system} instead of the host system type.
31155 This works as per @command{guix build} (@pxref{Invoking guix build}).
31159 Return the derivation file name of the given operating system without
31162 @cindex provenance tracking, of the operating system
31163 @item --save-provenance
31164 As discussed above, @command{guix system init} and @command{guix system
31165 reconfigure} always save provenance information @i{via} a dedicated
31166 service (@pxref{Service Reference, @code{provenance-service-type}}).
31167 However, other commands don't do that by default. If you wish to, say,
31168 create a virtual machine image that contains provenance information, you
31172 guix system vm-image --save-provenance config.scm
31175 That way, the resulting image will effectively ``embed its own source''
31176 in the form of meta-data in @file{/run/current-system}. With that
31177 information, one can rebuild the image to make sure it really contains
31178 what it pretends to contain; or they could use that to derive a variant
31181 @item --image-type=@var{type}
31182 @itemx -t @var{type}
31183 For the @code{disk-image} action, create an image with given @var{type}.
31185 When this option is omitted, @command{guix system} uses the @code{raw}
31188 @cindex ISO-9660 format
31189 @cindex CD image format
31190 @cindex DVD image format
31191 @option{--image-type=iso9660} produces an ISO-9660 image, suitable
31192 for burning on CDs and DVDs.
31194 @item --image-size=@var{size}
31195 For the @code{vm-image} and @code{disk-image} actions, create an image
31196 of the given @var{size}. @var{size} may be a number of bytes, or it may
31197 include a unit as a suffix (@pxref{Block size, size specifications,,
31198 coreutils, GNU Coreutils}).
31200 When this option is omitted, @command{guix system} computes an estimate
31201 of the image size as a function of the size of the system declared in
31206 For the @code{container} action, allow containers to access the host network,
31207 that is, do not create a network namespace.
31209 @item --root=@var{file}
31210 @itemx -r @var{file}
31211 Make @var{file} a symlink to the result, and register it as a garbage
31214 @item --skip-checks
31215 Skip pre-installation safety checks.
31217 By default, @command{guix system init} and @command{guix system
31218 reconfigure} perform safety checks: they make sure the file systems that
31219 appear in the @code{operating-system} declaration actually exist
31220 (@pxref{File Systems}), and that any Linux kernel modules that may be
31221 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
31222 RAM Disk}). Passing this option skips these tests altogether.
31224 @item --allow-downgrades
31225 Instruct @command{guix system reconfigure} to allow system downgrades.
31227 By default, @command{reconfigure} prevents you from downgrading your
31228 system. It achieves that by comparing the provenance info of your
31229 system (shown by @command{guix system describe}) with that of your
31230 @command{guix} command (shown by @command{guix describe}). If the
31231 commits for @command{guix} are not descendants of those used for your
31232 system, @command{guix system reconfigure} errors out. Passing
31233 @option{--allow-downgrades} allows you to bypass these checks.
31236 Make sure you understand its security implications before using
31237 @option{--allow-downgrades}.
31241 @cindex on-error strategy
31242 @cindex error strategy
31243 @item --on-error=@var{strategy}
31244 Apply @var{strategy} when an error occurs when reading @var{file}.
31245 @var{strategy} may be one of the following:
31248 @item nothing-special
31249 Report the error concisely and exit. This is the default strategy.
31252 Likewise, but also display a backtrace.
31255 Report the error and enter Guile's debugger. From there, you can run
31256 commands such as @code{,bt} to get a backtrace, @code{,locals} to
31257 display local variable values, and more generally inspect the state of the
31258 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
31259 a list of available debugging commands.
31263 Once you have built, configured, re-configured, and re-re-configured
31264 your Guix installation, you may find it useful to list the operating
31265 system generations available on disk---and that you can choose from the
31266 bootloader boot menu:
31271 Describe the current system generation: its file name, the kernel and
31272 bootloader used, etc., as well as provenance information when available.
31274 @item list-generations
31275 List a summary of each generation of the operating system available on
31276 disk, in a human-readable way. This is similar to the
31277 @option{--list-generations} option of @command{guix package}
31278 (@pxref{Invoking guix package}).
31280 Optionally, one can specify a pattern, with the same syntax that is used
31281 in @command{guix package --list-generations}, to restrict the list of
31282 generations displayed. For instance, the following command displays
31283 generations that are up to 10 days old:
31286 $ guix system list-generations 10d
31291 The @command{guix system} command has even more to offer! The following
31292 sub-commands allow you to visualize how your system services relate to
31295 @anchor{system-extension-graph}
31298 @item extension-graph
31299 Emit in Dot/Graphviz format to standard output the @dfn{service
31300 extension graph} of the operating system defined in @var{file}
31301 (@pxref{Service Composition}, for more information on service
31307 $ guix system extension-graph @var{file} | xdot -
31310 shows the extension relations among services.
31312 @anchor{system-shepherd-graph}
31313 @item shepherd-graph
31314 Emit in Dot/Graphviz format to standard output the @dfn{dependency
31315 graph} of shepherd services of the operating system defined in
31316 @var{file}. @xref{Shepherd Services}, for more information and for an
31321 @node Invoking guix deploy
31322 @section Invoking @code{guix deploy}
31324 We've already seen @code{operating-system} declarations used to manage a
31325 machine's configuration locally. Suppose you need to configure multiple
31326 machines, though---perhaps you're managing a service on the web that's
31327 comprised of several servers. @command{guix deploy} enables you to use those
31328 same @code{operating-system} declarations to manage multiple remote hosts at
31329 once as a logical ``deployment''.
31332 The functionality described in this section is still under development
31333 and is subject to change. Get in touch with us on
31334 @email{guix-devel@@gnu.org}!
31338 guix deploy @var{file}
31341 Such an invocation will deploy the machines that the code within @var{file}
31342 evaluates to. As an example, @var{file} might contain a definition like this:
31345 ;; This is a Guix deployment of a "bare bones" setup, with
31346 ;; no X11 display server, to a machine with an SSH daemon
31347 ;; listening on localhost:2222. A configuration such as this
31348 ;; may be appropriate for virtual machine with ports
31349 ;; forwarded to the host's loopback interface.
31351 (use-service-modules networking ssh)
31352 (use-package-modules bootloaders)
31356 (host-name "gnu-deployed")
31357 (timezone "Etc/UTC")
31358 (bootloader (bootloader-configuration
31359 (bootloader grub-bootloader)
31360 (target "/dev/vda")
31361 (terminal-outputs '(console))))
31362 (file-systems (cons (file-system
31364 (device "/dev/vda1")
31366 %base-file-systems))
31368 (append (list (service dhcp-client-service-type)
31369 (service openssh-service-type
31370 (openssh-configuration
31371 (permit-root-login #t)
31372 (allow-empty-passwords? #t))))
31376 (operating-system %system)
31377 (environment managed-host-environment-type)
31378 (configuration (machine-ssh-configuration
31379 (host-name "localhost")
31380 (system "x86_64-linux")
31382 (identity "./id_rsa")
31386 The file should evaluate to a list of @var{machine} objects. This example,
31387 upon being deployed, will create a new generation on the remote system
31388 realizing the @code{operating-system} declaration @code{%system}.
31389 @code{environment} and @code{configuration} specify how the machine should be
31390 provisioned---that is, how the computing resources should be created and
31391 managed. The above example does not create any resources, as a
31392 @code{'managed-host} is a machine that is already running the Guix system and
31393 available over the network. This is a particularly simple case; a more
31394 complex deployment may involve, for example, starting virtual machines through
31395 a Virtual Private Server (VPS) provider. In such a case, a different
31396 @var{environment} type would be used.
31398 Do note that you first need to generate a key pair on the coordinator machine
31399 to allow the daemon to export signed archives of files from the store
31400 (@pxref{Invoking guix archive}), though this step is automatic on Guix
31404 # guix archive --generate-key
31408 Each target machine must authorize the key of the master machine so that it
31409 accepts store items it receives from the coordinator:
31412 # guix archive --authorize < coordinator-public-key.txt
31415 @code{user}, in this example, specifies the name of the user account to log in
31416 as to perform the deployment. Its default value is @code{root}, but root
31417 login over SSH may be forbidden in some cases. To work around this,
31418 @command{guix deploy} can log in as an unprivileged user and employ
31419 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
31420 currently installed on the remote and can be invoked non-interactively as
31421 @code{user}. That is, the line in @code{sudoers} granting @code{user} the
31422 ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
31423 be accomplished with the following operating system configuration snippet:
31427 (gnu system)) ;for %sudoers-specification
31429 (define %user "username")
31434 (plain-file "sudoers"
31435 (string-append (plain-file-content %sudoers-specification)
31436 (format #f "~a ALL = NOPASSWD: ALL~%"
31441 For more information regarding the format of the @file{sudoers} file,
31442 consult @command{man sudoers}.
31444 @deftp {Data Type} machine
31445 This is the data type representing a single machine in a heterogeneous Guix
31449 @item @code{operating-system}
31450 The object of the operating system configuration to deploy.
31452 @item @code{environment}
31453 An @code{environment-type} describing how the machine should be provisioned.
31455 @item @code{configuration} (default: @code{#f})
31456 An object describing the configuration for the machine's @code{environment}.
31457 If the @code{environment} has a default configuration, @code{#f} may be used.
31458 If @code{#f} is used for an environment with no default configuration,
31459 however, an error will be thrown.
31463 @deftp {Data Type} machine-ssh-configuration
31464 This is the data type representing the SSH client parameters for a machine
31465 with an @code{environment} of @code{managed-host-environment-type}.
31468 @item @code{host-name}
31469 @item @code{build-locally?} (default: @code{#t})
31470 If false, system derivations will be built on the machine being deployed to.
31471 @item @code{system}
31472 The system type describing the architecture of the machine being deployed
31473 to---e.g., @code{"x86_64-linux"}.
31474 @item @code{authorize?} (default: @code{#t})
31475 If true, the coordinator's signing key will be added to the remote's ACL
31477 @item @code{port} (default: @code{22})
31478 @item @code{user} (default: @code{"root"})
31479 @item @code{identity} (default: @code{#f})
31480 If specified, the path to the SSH private key to use to authenticate with the
31483 @item @code{host-key} (default: @code{#f})
31484 This should be the SSH host key of the machine, which looks like this:
31487 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
31490 When @code{host-key} is @code{#f}, the server is authenticated against
31491 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
31494 @item @code{allow-downgrades?} (default: @code{#f})
31495 Whether to allow potential downgrades.
31497 Like @command{guix system reconfigure}, @command{guix deploy} compares
31498 the channel commits currently deployed on the remote host (as returned
31499 by @command{guix system describe}) to those currently in use (as
31500 returned by @command{guix describe}) to determine whether commits
31501 currently in use are descendants of those deployed. When this is not
31502 the case and @code{allow-downgrades?} is false, it raises an error.
31503 This ensures you do not accidentally downgrade remote machines.
31507 @deftp {Data Type} digital-ocean-configuration
31508 This is the data type describing the Droplet that should be created for a
31509 machine with an @code{environment} of @code{digital-ocean-environment-type}.
31512 @item @code{ssh-key}
31513 The path to the SSH private key to use to authenticate with the remote
31514 host. In the future, this field may not exist.
31516 A list of string ``tags'' that uniquely identify the machine. Must be given
31517 such that no two machines in the deployment have the same set of tags.
31518 @item @code{region}
31519 A Digital Ocean region slug, such as @code{"nyc3"}.
31521 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
31522 @item @code{enable-ipv6?}
31523 Whether or not the droplet should be created with IPv6 networking.
31527 @node Running Guix in a VM
31528 @section Running Guix in a Virtual Machine
31530 @cindex virtual machine
31531 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
31533 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
31534 This image is a compressed image in QCOW format. You will first need to
31535 decompress with @command{xz -d}, and then you can pass it to an emulator such
31536 as QEMU (see below for details).
31538 This image boots the Xfce graphical environment and it contains some
31539 commonly used tools. You can install more software in the image by running
31540 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
31541 also reconfigure the system based on its initial configuration file available
31542 as @file{/run/current-system/configuration.scm} (@pxref{Using the
31543 Configuration System}).
31545 Instead of using this pre-built image, one can also build their own virtual
31546 machine image using @command{guix system vm-image} (@pxref{Invoking guix
31547 system}). The returned image is in qcow2 format, which the
31548 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
31551 If you built your own image, you must copy it out of the store
31552 (@pxref{The Store}) and give yourself permission to write to the copy
31553 before you can use it. When invoking QEMU, you must choose a system
31554 emulator that is suitable for your hardware platform. Here is a minimal
31555 QEMU invocation that will boot the result of @command{guix system
31556 vm-image} on x86_64 hardware:
31559 $ qemu-system-x86_64 \
31560 -nic user,model=virtio-net-pci \
31561 -enable-kvm -m 1024 \
31562 -device virtio-blk,drive=myhd \
31563 -drive if=none,file=/tmp/qemu-image,id=myhd
31566 Here is what each of these options means:
31569 @item qemu-system-x86_64
31570 This specifies the hardware platform to emulate. This should match the
31573 @item -nic user,model=virtio-net-pci
31574 Enable the unprivileged user-mode network stack. The guest OS can
31575 access the host but not vice versa. This is the simplest way to get the
31576 guest OS online. @code{model} specifies which network device to emulate:
31577 @code{virtio-net-pci} is a special device made for virtualized operating
31578 systems and recommended for most uses. Assuming your hardware platform is
31579 x86_64, you can get a list of available NIC models by running
31580 @command{qemu-system-x86_64 -nic model=help}.
31583 If your system has hardware virtualization extensions, enabling the
31584 virtual machine support (KVM) of the Linux kernel will make things run
31587 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
31589 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
31590 which may be insufficient for some operations.
31592 @item -device virtio-blk,drive=myhd
31593 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
31594 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
31595 better performance than if it were emulating a complete disk drive. See the
31596 QEMU and KVM documentation for more info.
31598 @item -drive if=none,file=/tmp/qemu-image,id=myhd
31599 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing
31600 store of the ``myhd'' drive.
31603 The default @command{run-vm.sh} script that is returned by an invocation of
31604 @command{guix system vm} does not add a @command{-nic user} flag by default.
31605 To get network access from within the vm add the @code{(dhcp-client-service)}
31606 to your system definition and start the VM using
31607 @command{`guix system vm config.scm` -nic user}. An important caveat of using
31608 @command{-nic user} for networking is that @command{ping} will not work, because
31609 it uses the ICMP protocol. You'll have to use a different command to check for
31610 network connectivity, for example @command{guix download}.
31612 @subsection Connecting Through SSH
31616 To enable SSH inside a VM you need to add an SSH server like
31617 @code{openssh-service-type} to your VM (@pxref{Networking Services,
31618 @code{openssh-service-type}}). In addition you need to forward the SSH port,
31619 22 by default, to the host. You can do this with
31622 `guix system vm config.scm` -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
31625 To connect to the VM you can run
31628 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
31631 The @command{-p} tells @command{ssh} the port you want to connect to.
31632 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
31633 every time you modify your @command{config.scm} file and the
31634 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
31635 connection to an unknown host every time you connect.
31637 @subsection Using @command{virt-viewer} with Spice
31639 As an alternative to the default @command{qemu} graphical client you can
31640 use the @command{remote-viewer} from the @command{virt-viewer} package. To
31641 connect pass the @command{-spice port=5930,disable-ticketing} flag to
31642 @command{qemu}. See previous section for further information on how to do this.
31644 Spice also allows you to do some nice stuff like share your clipboard with your
31645 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
31648 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
31649 -chardev spicevmc,name=vdagent,id=vdagent
31650 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
31651 name=com.redhat.spice.0
31654 You'll also need to add the @code{(spice-vdagent-service)} to your
31655 system definition (@pxref{Miscellaneous Services, Spice service}).
31657 @node Defining Services
31658 @section Defining Services
31660 The previous sections show the available services and how one can combine
31661 them in an @code{operating-system} declaration. But how do we define
31662 them in the first place? And what is a service anyway?
31665 * Service Composition:: The model for composing services.
31666 * Service Types and Services:: Types and services.
31667 * Service Reference:: API reference.
31668 * Shepherd Services:: A particular type of service.
31671 @node Service Composition
31672 @subsection Service Composition
31676 Here we define a @dfn{service} as, broadly, something that extends the
31677 functionality of the operating system. Often a service is a process---a
31678 @dfn{daemon}---started when the system boots: a secure shell server, a
31679 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
31680 whose execution can be triggered by another daemon---e.g., an FTP server
31681 started by @command{inetd} or a D-Bus service activated by
31682 @command{dbus-daemon}. Occasionally, a service does not map to a
31683 daemon. For instance, the ``account'' service collects user accounts
31684 and makes sure they exist when the system runs; the ``udev'' service
31685 collects device management rules and makes them available to the eudev
31686 daemon; the @file{/etc} service populates the @file{/etc} directory
31689 @cindex service extensions
31690 Guix system services are connected by @dfn{extensions}. For instance, the
31691 secure shell service @emph{extends} the Shepherd---the
31692 initialization system, running as PID@tie{}1---by giving it the command
31693 lines to start and stop the secure shell daemon (@pxref{Networking
31694 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
31695 service by passing it its @file{.service} specification, and extends the
31696 udev service by passing it device management rules (@pxref{Desktop
31697 Services, @code{upower-service}}); the Guix daemon service extends the
31698 Shepherd by passing it the command lines to start and stop the daemon,
31699 and extends the account service by passing it a list of required build
31700 user accounts (@pxref{Base Services}).
31702 All in all, services and their ``extends'' relations form a directed
31703 acyclic graph (DAG). If we represent services as boxes and extensions
31704 as arrows, a typical system might provide something like this:
31706 @image{images/service-graph,,5in,Typical service extension graph.}
31708 @cindex system service
31709 At the bottom, we see the @dfn{system service}, which produces the
31710 directory containing everything to run and boot the system, as returned
31711 by the @command{guix system build} command. @xref{Service Reference},
31712 to learn about the other service types shown here.
31713 @xref{system-extension-graph, the @command{guix system extension-graph}
31714 command}, for information on how to generate this representation for a
31715 particular operating system definition.
31717 @cindex service types
31718 Technically, developers can define @dfn{service types} to express these
31719 relations. There can be any number of services of a given type on the
31720 system---for instance, a system running two instances of the GNU secure
31721 shell server (lsh) has two instances of @code{lsh-service-type}, with
31722 different parameters.
31724 The following section describes the programming interface for service
31725 types and services.
31727 @node Service Types and Services
31728 @subsection Service Types and Services
31730 A @dfn{service type} is a node in the DAG described above. Let us start
31731 with a simple example, the service type for the Guix build daemon
31732 (@pxref{Invoking guix-daemon}):
31735 (define guix-service-type
31739 (list (service-extension shepherd-root-service-type guix-shepherd-service)
31740 (service-extension account-service-type guix-accounts)
31741 (service-extension activation-service-type guix-activation)))
31742 (default-value (guix-configuration))))
31746 It defines three things:
31750 A name, whose sole purpose is to make inspection and debugging easier.
31753 A list of @dfn{service extensions}, where each extension designates the
31754 target service type and a procedure that, given the parameters of the
31755 service, returns a list of objects to extend the service of that type.
31757 Every service type has at least one service extension. The only
31758 exception is the @dfn{boot service type}, which is the ultimate service.
31761 Optionally, a default value for instances of this type.
31764 In this example, @code{guix-service-type} extends three services:
31767 @item shepherd-root-service-type
31768 The @code{guix-shepherd-service} procedure defines how the Shepherd
31769 service is extended. Namely, it returns a @code{<shepherd-service>}
31770 object that defines how @command{guix-daemon} is started and stopped
31771 (@pxref{Shepherd Services}).
31773 @item account-service-type
31774 This extension for this service is computed by @code{guix-accounts},
31775 which returns a list of @code{user-group} and @code{user-account}
31776 objects representing the build user accounts (@pxref{Invoking
31779 @item activation-service-type
31780 Here @code{guix-activation} is a procedure that returns a gexp, which is
31781 a code snippet to run at ``activation time''---e.g., when the service is
31785 A service of this type is instantiated like this:
31788 (service guix-service-type
31789 (guix-configuration
31791 (extra-options '("--gc-keep-derivations"))))
31794 The second argument to the @code{service} form is a value representing
31795 the parameters of this specific service instance.
31796 @xref{guix-configuration-type, @code{guix-configuration}}, for
31797 information about the @code{guix-configuration} data type. When the
31798 value is omitted, the default value specified by
31799 @code{guix-service-type} is used:
31802 (service guix-service-type)
31805 @code{guix-service-type} is quite simple because it extends other
31806 services but is not extensible itself.
31808 @c @subsubsubsection Extensible Service Types
31810 The service type for an @emph{extensible} service looks like this:
31813 (define udev-service-type
31814 (service-type (name 'udev)
31816 (list (service-extension shepherd-root-service-type
31817 udev-shepherd-service)))
31819 (compose concatenate) ;concatenate the list of rules
31820 (extend (lambda (config rules)
31822 (($ <udev-configuration> udev initial-rules)
31823 (udev-configuration
31824 (udev udev) ;the udev package to use
31825 (rules (append initial-rules rules)))))))))
31828 This is the service type for the
31829 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
31830 management daemon}. Compared to the previous example, in addition to an
31831 extension of @code{shepherd-root-service-type}, we see two new fields:
31835 This is the procedure to @dfn{compose} the list of extensions to
31836 services of this type.
31838 Services can extend the udev service by passing it lists of rules; we
31839 compose those extensions simply by concatenating them.
31842 This procedure defines how the value of the service is @dfn{extended} with
31843 the composition of the extensions.
31845 Udev extensions are composed into a list of rules, but the udev service
31846 value is itself a @code{<udev-configuration>} record. So here, we
31847 extend that record by appending the list of rules it contains to the
31848 list of contributed rules.
31851 This is a string giving an overview of the service type. The string can
31852 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
31853 @command{guix system search} command searches these strings and displays
31854 them (@pxref{Invoking guix system}).
31857 There can be only one instance of an extensible service type such as
31858 @code{udev-service-type}. If there were more, the
31859 @code{service-extension} specifications would be ambiguous.
31861 Still here? The next section provides a reference of the programming
31862 interface for services.
31864 @node Service Reference
31865 @subsection Service Reference
31867 We have seen an overview of service types (@pxref{Service Types and
31868 Services}). This section provides a reference on how to manipulate
31869 services and service types. This interface is provided by the
31870 @code{(gnu services)} module.
31872 @deffn {Scheme Procedure} service @var{type} [@var{value}]
31873 Return a new service of @var{type}, a @code{<service-type>} object (see
31874 below). @var{value} can be any object; it represents the parameters of
31875 this particular service instance.
31877 When @var{value} is omitted, the default value specified by @var{type}
31878 is used; if @var{type} does not specify a default value, an error is
31881 For instance, this:
31884 (service openssh-service-type)
31888 is equivalent to this:
31891 (service openssh-service-type
31892 (openssh-configuration))
31895 In both cases the result is an instance of @code{openssh-service-type}
31896 with the default configuration.
31899 @deffn {Scheme Procedure} service? @var{obj}
31900 Return true if @var{obj} is a service.
31903 @deffn {Scheme Procedure} service-kind @var{service}
31904 Return the type of @var{service}---i.e., a @code{<service-type>} object.
31907 @deffn {Scheme Procedure} service-value @var{service}
31908 Return the value associated with @var{service}. It represents its
31912 Here is an example of how a service is created and manipulated:
31916 (service nginx-service-type
31917 (nginx-configuration
31919 (log-directory log-directory)
31920 (run-directory run-directory)
31921 (file config-file))))
31926 (eq? (service-kind s) nginx-service-type)
31930 The @code{modify-services} form provides a handy way to change the
31931 parameters of some of the services of a list such as
31932 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
31933 evaluates to a list of services. Of course, you could always use
31934 standard list combinators such as @code{map} and @code{fold} to do that
31935 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
31936 @code{modify-services} simply provides a more concise form for this
31939 @deffn {Scheme Syntax} modify-services @var{services} @
31940 (@var{type} @var{variable} => @var{body}) @dots{}
31942 Modify the services listed in @var{services} according to the given
31943 clauses. Each clause has the form:
31946 (@var{type} @var{variable} => @var{body})
31949 where @var{type} is a service type---e.g.,
31950 @code{guix-service-type}---and @var{variable} is an identifier that is
31951 bound within the @var{body} to the service parameters---e.g., a
31952 @code{guix-configuration} instance---of the original service of that
31955 The @var{body} should evaluate to the new service parameters, which will
31956 be used to configure the new service. This new service will replace the
31957 original in the resulting list. Because a service's service parameters
31958 are created using @code{define-record-type*}, you can write a succinct
31959 @var{body} that evaluates to the new service parameters by using the
31960 @code{inherit} feature that @code{define-record-type*} provides.
31962 @xref{Using the Configuration System}, for example usage.
31966 Next comes the programming interface for service types. This is
31967 something you want to know when writing new service definitions, but not
31968 necessarily when simply looking for ways to customize your
31969 @code{operating-system} declaration.
31971 @deftp {Data Type} service-type
31972 @cindex service type
31973 This is the representation of a @dfn{service type} (@pxref{Service Types
31978 This is a symbol, used only to simplify inspection and debugging.
31980 @item @code{extensions}
31981 A non-empty list of @code{<service-extension>} objects (see below).
31983 @item @code{compose} (default: @code{#f})
31984 If this is @code{#f}, then the service type denotes services that cannot
31985 be extended---i.e., services that do not receive ``values'' from other
31988 Otherwise, it must be a one-argument procedure. The procedure is called
31989 by @code{fold-services} and is passed a list of values collected from
31990 extensions. It may return any single value.
31992 @item @code{extend} (default: @code{#f})
31993 If this is @code{#f}, services of this type cannot be extended.
31995 Otherwise, it must be a two-argument procedure: @code{fold-services}
31996 calls it, passing it the initial value of the service as the first
31997 argument and the result of applying @code{compose} to the extension
31998 values as the second argument. It must return a value that is a valid
31999 parameter value for the service instance.
32001 @item @code{description}
32002 This is a string, possibly using Texinfo markup, describing in a couple
32003 of sentences what the service is about. This string allows users to
32004 find about the service through @command{guix system search}
32005 (@pxref{Invoking guix system}).
32007 @item @code{default-value} (default: @code{&no-default-value})
32008 The default value associated for instances of this service type. This
32009 allows users to use the @code{service} form without its second argument:
32012 (service @var{type})
32015 The returned service in this case has the default value specified by
32019 @xref{Service Types and Services}, for examples.
32022 @deffn {Scheme Procedure} service-extension @var{target-type} @
32024 Return a new extension for services of type @var{target-type}.
32025 @var{compute} must be a one-argument procedure: @code{fold-services}
32026 calls it, passing it the value associated with the service that provides
32027 the extension; it must return a valid value for the target service.
32030 @deffn {Scheme Procedure} service-extension? @var{obj}
32031 Return true if @var{obj} is a service extension.
32034 Occasionally, you might want to simply extend an existing service. This
32035 involves creating a new service type and specifying the extension of
32036 interest, which can be verbose; the @code{simple-service} procedure
32037 provides a shorthand for this.
32039 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
32040 Return a service that extends @var{target} with @var{value}. This works
32041 by creating a singleton service type @var{name}, of which the returned
32042 service is an instance.
32044 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
32048 (simple-service 'my-mcron-job mcron-service-type
32049 #~(job '(next-hour (3)) "guix gc -F 2G"))
32053 At the core of the service abstraction lies the @code{fold-services}
32054 procedure, which is responsible for ``compiling'' a list of services
32055 down to a single directory that contains everything needed to boot and
32056 run the system---the directory shown by the @command{guix system build}
32057 command (@pxref{Invoking guix system}). In essence, it propagates
32058 service extensions down the service graph, updating each node parameters
32059 on the way, until it reaches the root node.
32061 @deffn {Scheme Procedure} fold-services @var{services} @
32062 [#:target-type @var{system-service-type}]
32063 Fold @var{services} by propagating their extensions down to the root of
32064 type @var{target-type}; return the root service adjusted accordingly.
32067 Lastly, the @code{(gnu services)} module also defines several essential
32068 service types, some of which are listed below.
32070 @defvr {Scheme Variable} system-service-type
32071 This is the root of the service graph. It produces the system directory
32072 as returned by the @command{guix system build} command.
32075 @defvr {Scheme Variable} boot-service-type
32076 The type of the ``boot service'', which produces the @dfn{boot script}.
32077 The boot script is what the initial RAM disk runs when booting.
32080 @defvr {Scheme Variable} etc-service-type
32081 The type of the @file{/etc} service. This service is used to create
32082 files under @file{/etc} and can be extended by
32083 passing it name/file tuples such as:
32086 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
32089 In this example, the effect would be to add an @file{/etc/issue} file
32090 pointing to the given file.
32093 @defvr {Scheme Variable} setuid-program-service-type
32094 Type for the ``setuid-program service''. This service collects lists of
32095 executable file names, passed as gexps, and adds them to the set of
32096 setuid-root programs on the system (@pxref{Setuid Programs}).
32099 @defvr {Scheme Variable} profile-service-type
32100 Type of the service that populates the @dfn{system profile}---i.e., the
32101 programs under @file{/run/current-system/profile}. Other services can
32102 extend it by passing it lists of packages to add to the system profile.
32105 @cindex provenance tracking, of the operating system
32106 @anchor{provenance-service-type}
32107 @defvr {Scheme Variable} provenance-service-type
32108 This is the type of the service that records @dfn{provenance meta-data}
32109 in the system itself. It creates several files under
32110 @file{/run/current-system}:
32114 This is a ``channel file'' that can be passed to @command{guix pull -C}
32115 or @command{guix time-machine -C}, and which describes the channels used
32116 to build the system, if that information was available
32117 (@pxref{Channels}).
32119 @item configuration.scm
32120 This is the file that was passed as the value for this
32121 @code{provenance-service-type} service. By default, @command{guix
32122 system reconfigure} automatically passes the OS configuration file it
32123 received on the command line.
32126 This contains the same information as the two other files but in a
32127 format that is more readily processable.
32130 In general, these two pieces of information (channels and configuration
32131 file) are enough to reproduce the operating system ``from source''.
32134 This information is necessary to rebuild your operating system, but it
32135 is not always sufficient. In particular, @file{configuration.scm}
32136 itself is insufficient if it is not self-contained---if it refers to
32137 external Guile modules or to extra files. If you want
32138 @file{configuration.scm} to be self-contained, we recommend that modules
32139 or files it refers to be part of a channel.
32141 Besides, provenance meta-data is ``silent'' in the sense that it does
32142 not change the bits contained in your system, @emph{except for the
32143 meta-data bits themselves}. Two different OS configurations or sets of
32144 channels can lead to the same system, bit-for-bit; when
32145 @code{provenance-service-type} is used, these two systems will have
32146 different meta-data and thus different store file names, which makes
32147 comparison less trivial.
32150 This service is automatically added to your operating system
32151 configuration when you use @command{guix system reconfigure},
32152 @command{guix system init}, or @command{guix deploy}.
32155 @node Shepherd Services
32156 @subsection Shepherd Services
32158 @cindex shepherd services
32160 @cindex init system
32161 The @code{(gnu services shepherd)} module provides a way to define
32162 services managed by the GNU@tie{}Shepherd, which is the
32163 initialization system---the first process that is started when the
32164 system boots, also known as PID@tie{}1
32165 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
32167 Services in the Shepherd can depend on each other. For instance, the
32168 SSH daemon may need to be started after the syslog daemon has been
32169 started, which in turn can only happen once all the file systems have
32170 been mounted. The simple operating system defined earlier (@pxref{Using
32171 the Configuration System}) results in a service graph like this:
32173 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
32175 You can actually generate such a graph for any operating system
32176 definition using the @command{guix system shepherd-graph} command
32177 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
32179 The @code{%shepherd-root-service} is a service object representing
32180 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
32181 by passing it lists of @code{<shepherd-service>} objects.
32183 @deftp {Data Type} shepherd-service
32184 The data type representing a service managed by the Shepherd.
32187 @item @code{provision}
32188 This is a list of symbols denoting what the service provides.
32190 These are the names that may be passed to @command{herd start},
32191 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
32192 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
32193 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
32195 @item @code{requirement} (default: @code{'()})
32196 List of symbols denoting the Shepherd services this one depends on.
32198 @cindex one-shot services, for the Shepherd
32199 @item @code{one-shot?} (default: @code{#f})
32200 Whether this service is @dfn{one-shot}. One-shot services stop immediately
32201 after their @code{start} action has completed. @xref{Slots of services,,,
32202 shepherd, The GNU Shepherd Manual}, for more info.
32204 @item @code{respawn?} (default: @code{#t})
32205 Whether to restart the service when it stops, for instance when the
32206 underlying process dies.
32209 @itemx @code{stop} (default: @code{#~(const #f)})
32210 The @code{start} and @code{stop} fields refer to the Shepherd's
32211 facilities to start and stop processes (@pxref{Service De- and
32212 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
32213 G-expressions that get expanded in the Shepherd configuration file
32214 (@pxref{G-Expressions}).
32216 @item @code{actions} (default: @code{'()})
32217 @cindex actions, of Shepherd services
32218 This is a list of @code{shepherd-action} objects (see below) defining
32219 @dfn{actions} supported by the service, in addition to the standard
32220 @code{start} and @code{stop} actions. Actions listed here become available as
32221 @command{herd} sub-commands:
32224 herd @var{action} @var{service} [@var{arguments}@dots{}]
32227 @item @code{auto-start?} (default: @code{#t})
32228 Whether this service should be started automatically by the Shepherd. If it
32229 is @code{#f} the service has to be started manually with @code{herd start}.
32231 @item @code{documentation}
32232 A documentation string, as shown when running:
32235 herd doc @var{service-name}
32238 where @var{service-name} is one of the symbols in @code{provision}
32239 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
32241 @item @code{modules} (default: @code{%default-modules})
32242 This is the list of modules that must be in scope when @code{start} and
32243 @code{stop} are evaluated.
32248 @deftp {Data Type} shepherd-action
32249 This is the data type that defines additional actions implemented by a
32250 Shepherd service (see above).
32254 Symbol naming the action.
32256 @item documentation
32257 This is a documentation string for the action. It can be viewed by running:
32260 herd doc @var{service} action @var{action}
32264 This should be a gexp that evaluates to a procedure of at least one argument,
32265 which is the ``running value'' of the service (@pxref{Slots of services,,,
32266 shepherd, The GNU Shepherd Manual}).
32269 The following example defines an action called @code{say-hello} that kindly
32275 (documentation "Say hi!")
32276 (procedure #~(lambda (running . args)
32277 (format #t "Hello, friend! arguments: ~s\n"
32282 Assuming this action is added to the @code{example} service, then you can do:
32285 # herd say-hello example
32286 Hello, friend! arguments: ()
32287 # herd say-hello example a b c
32288 Hello, friend! arguments: ("a" "b" "c")
32291 This, as you can see, is a fairly sophisticated way to say hello.
32292 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
32296 @defvr {Scheme Variable} shepherd-root-service-type
32297 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
32299 This is the service type that extensions target when they want to create
32300 shepherd services (@pxref{Service Types and Services}, for an example).
32301 Each extension must pass a list of @code{<shepherd-service>}.
32304 @defvr {Scheme Variable} %shepherd-root-service
32305 This service represents PID@tie{}1.
32309 @node Documentation
32310 @chapter Documentation
32312 @cindex documentation, searching for
32313 @cindex searching for documentation
32314 @cindex Info, documentation format
32316 @cindex manual pages
32317 In most cases packages installed with Guix come with documentation.
32318 There are two main documentation formats: ``Info'', a browseable
32319 hypertext format used for GNU software, and ``manual pages'' (or ``man
32320 pages''), the linear documentation format traditionally found on Unix.
32321 Info manuals are accessed with the @command{info} command or with Emacs,
32322 and man pages are accessed using @command{man}.
32324 You can look for documentation of software installed on your system by
32325 keyword. For example, the following command searches for information
32326 about ``TLS'' in Info manuals:
32330 "(emacs)Network Security" -- STARTTLS
32331 "(emacs)Network Security" -- TLS
32332 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
32333 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
32338 The command below searches for the same keyword in man pages:
32342 SSL (7) - OpenSSL SSL/TLS library
32343 certtool (1) - GnuTLS certificate tool
32347 These searches are purely local to your computer so you have the
32348 guarantee that documentation you find corresponds to what you have
32349 actually installed, you can access it off-line, and your privacy is
32352 Once you have these results, you can view the relevant documentation by
32356 $ info "(gnutls)Core TLS API"
32366 Info manuals contain sections and indices as well as hyperlinks like
32367 those found in Web pages. The @command{info} reader (@pxref{Top, Info
32368 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
32369 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
32370 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
32371 Introduction}, for an introduction to Info navigation.
32373 @node Installing Debugging Files
32374 @chapter Installing Debugging Files
32376 @cindex debugging files
32377 Program binaries, as produced by the GCC compilers for instance, are
32378 typically written in the ELF format, with a section containing
32379 @dfn{debugging information}. Debugging information is what allows the
32380 debugger, GDB, to map binary code to source code; it is required to
32381 debug a compiled program in good conditions.
32383 This chapter explains how to use separate debug info when packages
32384 provide it, and how to rebuild packages with debug info when it's
32388 * Separate Debug Info:: Installing 'debug' outputs.
32389 * Rebuilding Debug Info:: Building missing debug info.
32392 @node Separate Debug Info
32393 @section Separate Debug Info
32395 The problem with debugging information is that is takes up a fair amount
32396 of disk space. For example, debugging information for the GNU C Library
32397 weighs in at more than 60 MiB. Thus, as a user, keeping all the
32398 debugging info of all the installed programs is usually not an option.
32399 Yet, space savings should not come at the cost of an impediment to
32400 debugging---especially in the GNU system, which should make it easier
32401 for users to exert their computing freedom (@pxref{GNU Distribution}).
32403 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
32404 mechanism that allows users to get the best of both worlds: debugging
32405 information can be stripped from the binaries and stored in separate
32406 files. GDB is then able to load debugging information from those files,
32407 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
32410 The GNU distribution takes advantage of this by storing debugging
32411 information in the @code{lib/debug} sub-directory of a separate package
32412 output unimaginatively called @code{debug} (@pxref{Packages with
32413 Multiple Outputs}). Users can choose to install the @code{debug} output
32414 of a package when they need it. For instance, the following command
32415 installs the debugging information for the GNU C Library and for GNU
32419 guix install glibc:debug guile:debug
32422 GDB must then be told to look for debug files in the user's profile, by
32423 setting the @code{debug-file-directory} variable (consider setting it
32424 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
32428 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
32431 From there on, GDB will pick up debugging information from the
32432 @file{.debug} files under @file{~/.guix-profile/lib/debug}.
32434 In addition, you will most likely want GDB to be able to show the source
32435 code being debugged. To do that, you will have to unpack the source
32436 code of the package of interest (obtained with @code{guix build
32437 --source}, @pxref{Invoking guix build}), and to point GDB to that source
32438 directory using the @code{directory} command (@pxref{Source Path,
32439 @code{directory},, gdb, Debugging with GDB}).
32441 @c XXX: keep me up-to-date
32442 The @code{debug} output mechanism in Guix is implemented by the
32443 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
32444 opt-in---debugging information is available only for the packages with
32445 definitions explicitly declaring a @code{debug} output. To check
32446 whether a package has a @code{debug} output, use @command{guix package
32447 --list-available} (@pxref{Invoking guix package}).
32449 Read on for how to deal with packages lacking a @code{debug} output.
32451 @node Rebuilding Debug Info
32452 @section Rebuilding Debug Info
32454 @cindex debugging info, rebuilding
32455 As we saw above, some packages, but not all, provide debugging info in a
32456 @code{debug} output. What can you do when debugging info is missing?
32457 The @option{--with-debug-info} option provides a solution to that: it
32458 allows you to rebuild the package(s) for which debugging info is
32459 missing---and only those---and to graft those onto the application
32460 you're debugging. Thus, while it's not as fast as installing a
32461 @code{debug} output, it is relatively inexpensive.
32463 Let's illustrate that. Suppose you're experiencing a bug in Inkscape
32464 and would like to see what's going on in GLib, a library that's deep
32465 down in its dependency graph. As it turns out, GLib does not have a
32466 @code{debug} output and the backtrace GDB shows is all sadness:
32470 #0 0x00007ffff5f92190 in g_getenv ()
32471 from /gnu/store/@dots{}-glib-2.62.6/lib/libglib-2.0.so.0
32472 #1 0x00007ffff608a7d6 in gobject_init_ctor ()
32473 from /gnu/store/@dots{}-glib-2.62.6/lib/libgobject-2.0.so.0
32474 #2 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=1, argv=argv@@entry=0x7fffffffcfd8,
32475 env=env@@entry=0x7fffffffcfe8) at dl-init.c:72
32476 #3 0x00007ffff7fe2866 in call_init (env=0x7fffffffcfe8, argv=0x7fffffffcfd8, argc=1, l=<optimized out>)
32480 To address that, you install Inkscape linked against a variant GLib that
32481 contains debug info:
32484 guix install inkscape --with-debug-info=glib
32487 This time, debugging will be a whole lot nicer:
32490 $ gdb --args sh -c 'exec inkscape'
32493 Function "g_getenv" not defined.
32494 Make breakpoint pending on future shared library load? (y or [n]) y
32495 Breakpoint 1 (g_getenv) pending.
32497 Starting program: /gnu/store/@dots{}-profile/bin/sh -c exec\ inkscape
32500 #0 g_getenv (variable=variable@@entry=0x7ffff60c7a2e "GOBJECT_DEBUG") at ../glib-2.62.6/glib/genviron.c:252
32501 #1 0x00007ffff608a7d6 in gobject_init () at ../glib-2.62.6/gobject/gtype.c:4380
32502 #2 gobject_init_ctor () at ../glib-2.62.6/gobject/gtype.c:4493
32503 #3 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=3, argv=argv@@entry=0x7fffffffd088,
32504 env=env@@entry=0x7fffffffd0a8) at dl-init.c:72
32510 Note that there can be packages for which @option{--with-debug-info}
32511 will not have the desired effect. @xref{Package Transformation Options,
32512 @option{--with-debug-info}}, for more information.
32514 @node Security Updates
32515 @chapter Security Updates
32517 @cindex security updates
32518 @cindex security vulnerabilities
32519 Occasionally, important security vulnerabilities are discovered in software
32520 packages and must be patched. Guix developers try hard to keep track of
32521 known vulnerabilities and to apply fixes as soon as possible in the
32522 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
32523 containing only security updates). The @command{guix lint} tool helps
32524 developers find out about vulnerable versions of software packages in the
32529 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
32530 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
32531 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
32535 @xref{Invoking guix lint}, for more information.
32537 Guix follows a functional
32538 package management discipline (@pxref{Introduction}), which implies
32539 that, when a package is changed, @emph{every package that depends on it}
32540 must be rebuilt. This can significantly slow down the deployment of
32541 fixes in core packages such as libc or Bash, since basically the whole
32542 distribution would need to be rebuilt. Using pre-built binaries helps
32543 (@pxref{Substitutes}), but deployment may still take more time than
32547 To address this, Guix implements @dfn{grafts}, a mechanism that allows
32548 for fast deployment of critical updates without the costs associated
32549 with a whole-distribution rebuild. The idea is to rebuild only the
32550 package that needs to be patched, and then to ``graft'' it onto packages
32551 explicitly installed by the user and that were previously referring to
32552 the original package. The cost of grafting is typically very low, and
32553 order of magnitudes lower than a full rebuild of the dependency chain.
32555 @cindex replacements of packages, for grafts
32556 For instance, suppose a security update needs to be applied to Bash.
32557 Guix developers will provide a package definition for the ``fixed''
32558 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
32559 Packages}). Then, the original package definition is augmented with a
32560 @code{replacement} field pointing to the package containing the bug fix:
32567 (replacement bash-fixed)))
32570 From there on, any package depending directly or indirectly on Bash---as
32571 reported by @command{guix gc --requisites} (@pxref{Invoking guix
32572 gc})---that is installed is automatically ``rewritten'' to refer to
32573 @code{bash-fixed} instead of @code{bash}. This grafting process takes
32574 time proportional to the size of the package, usually less than a
32575 minute for an ``average'' package on a recent machine. Grafting is
32576 recursive: when an indirect dependency requires grafting, then grafting
32577 ``propagates'' up to the package that the user is installing.
32579 Currently, the length of the name and version of the graft and that of
32580 the package it replaces (@code{bash-fixed} and @code{bash} in the example
32581 above) must be equal. This restriction mostly comes from the fact that
32582 grafting works by patching files, including binary files, directly.
32583 Other restrictions may apply: for instance, when adding a graft to a
32584 package providing a shared library, the original shared library and its
32585 replacement must have the same @code{SONAME} and be binary-compatible.
32587 The @option{--no-grafts} command-line option allows you to forcefully
32588 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
32592 guix build bash --no-grafts
32596 returns the store file name of the original Bash, whereas:
32603 returns the store file name of the ``fixed'', replacement Bash. This
32604 allows you to distinguish between the two variants of Bash.
32606 To verify which Bash your whole profile refers to, you can run
32607 (@pxref{Invoking guix gc}):
32610 guix gc -R `readlink -f ~/.guix-profile` | grep bash
32614 @dots{} and compare the store file names that you get with those above.
32615 Likewise for a complete Guix system generation:
32618 guix gc -R `guix system build my-config.scm` | grep bash
32621 Lastly, to check which Bash running processes are using, you can use the
32622 @command{lsof} command:
32625 lsof | grep /gnu/store/.*bash
32629 @node Bootstrapping
32630 @chapter Bootstrapping
32632 @c Adapted from the ELS 2013 paper.
32634 @cindex bootstrapping
32636 Bootstrapping in our context refers to how the distribution gets built
32637 ``from nothing''. Remember that the build environment of a derivation
32638 contains nothing but its declared inputs (@pxref{Introduction}). So
32639 there's an obvious chicken-and-egg problem: how does the first package
32640 get built? How does the first compiler get compiled? Note that this is
32641 a question of interest only to the curious hacker, not to the regular
32642 user, so you can shamelessly skip this section if you consider yourself
32643 a ``regular user''.
32645 @cindex bootstrap binaries
32646 The GNU system is primarily made of C code, with libc at its core. The
32647 GNU build system itself assumes the availability of a Bourne shell and
32648 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
32649 `grep'. Furthermore, build programs---programs that run
32650 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
32651 (@pxref{Derivations}). Consequently, to be able to build anything at
32652 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
32653 Binutils, libc, and the other packages mentioned above---the
32654 @dfn{bootstrap binaries}.
32656 These bootstrap binaries are ``taken for granted'', though we can also
32657 re-create them if needed (@pxref{Preparing to Use the Bootstrap
32661 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
32662 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
32665 @node Reduced Binary Seed Bootstrap
32666 @section The Reduced Binary Seed Bootstrap
32668 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
32669 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
32670 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
32671 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
32672 ``taken for granted.''
32674 Taking the bootstrap binaries for granted means that we consider them to
32675 be a correct and trustworthy ``seed'' for building the complete system.
32676 Therein lies a problem: the combined size of these bootstrap binaries is
32677 about 250MB (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing
32678 or even inspecting these is next to impossible.
32680 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a
32681 ``Reduced Binary Seed'' bootstrap @footnote{We would like to say: ``Full
32682 Source Bootstrap'' and while we are working towards that goal it would
32683 be hyperbole to use that term for what we do now.}.
32685 The Reduced Binary Seed bootstrap removes the most critical tools---from a
32686 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
32687 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
32688 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
32689 written in Scheme and the Mes C Library, built for TinyCC and for GCC).
32691 Using these new binary seeds the ``missing'' Binutils, GCC, and the GNU
32692 C Library are built from source. From here on the more traditional
32693 bootstrap process resumes. This approach has reduced the bootstrap
32694 binaries in size to about 145MB in Guix v1.1.
32696 The next step that Guix has taken is to replace the shell and all its
32697 utilities with implementations in Guile Scheme, the @emph{Scheme-only
32698 bootstrap}. Gash (@pxref{Gash,,, gash, The Gash manual}) is a
32699 POSIX-compatible shell that replaces Bash, and it comes with Gash Utils
32700 which has minimalist replacements for Awk, the GNU Core Utilities, Grep,
32701 Gzip, Sed, and Tar. The rest of the bootstrap binary seeds that were
32702 removed are now built from source.
32704 Building the GNU System from source is currently only possibly by adding
32705 some historical GNU packages as intermediate steps@footnote{Packages
32706 such as @code{gcc-2.95.3}, @code{binutils-2.14}, @code{glibc-2.2.5},
32707 @code{gzip-1.2.4}, @code{tar-1.22}, and some others. For details, see
32708 @file{gnu/packages/commencement.scm}.}. As Gash and Gash Utils mature,
32709 and GNU packages become more bootstrappable again (e.g., new releases of
32710 GNU Sed will also ship as gzipped tarballs again, as alternative to the
32711 hard to bootstrap @code{xz}-compression), this set of added packages can
32712 hopefully be reduced again.
32714 The graph below shows the resulting dependency graph for
32715 @code{gcc-core-mesboot0}, the bootstrap compiler used for the
32716 traditional bootstrap of the rest of the Guix System.
32718 @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
32719 @image{images/gcc-core-mesboot0-graph,6in,,Dependency graph of gcc-core-mesboot0}
32721 The only significant binary bootstrap seeds that remain@footnote{
32722 Ignoring the 68KB @code{mescc-tools}; that will be removed later,
32723 together with @code{mes}.} are a Scheme intepreter and a Scheme
32724 compiler: GNU Mes and GNU Guile@footnote{Not shown in this graph are the
32725 static binaries for @file{bash}, @code{tar}, and @code{xz} that are used
32726 to get Guile running.}.
32728 This further reduction has brought down the size of the binary seed to
32729 about 60MB for @code{i686-linux} and @code{x86_64-linux}.
32731 Work is ongoing to remove all binary blobs from our free software
32732 bootstrap stack, working towards a Full Source Bootstrap. Also ongoing
32733 is work to bring these bootstraps to the @code{arm-linux} and
32734 @code{aarch64-linux} architectures and to the Hurd.
32736 If you are interested, join us on @samp{#bootstrappable} on the Freenode
32737 IRC network or discuss on @email{bug-mes@@gnu.org} or
32738 @email{gash-devel@@nongnu.org}.
32740 @node Preparing to Use the Bootstrap Binaries
32741 @section Preparing to Use the Bootstrap Binaries
32743 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
32744 @c large image, it's hard to scroll. Oh well.
32745 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
32747 The figure above shows the very beginning of the dependency graph of the
32748 distribution, corresponding to the package definitions of the @code{(gnu
32749 packages bootstrap)} module. A similar figure can be generated with
32750 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
32753 guix graph -t derivation \
32754 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
32755 | dot -Tps > gcc.ps
32758 or, for the further Reduced Binary Seed bootstrap
32761 guix graph -t derivation \
32762 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
32763 | dot -Tps > mes.ps
32766 At this level of detail, things are
32767 slightly complex. First, Guile itself consists of an ELF executable,
32768 along with many source and compiled Scheme files that are dynamically
32769 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
32770 tarball shown in this graph. This tarball is part of Guix's ``source''
32771 distribution, and gets inserted into the store with @code{add-to-store}
32772 (@pxref{The Store}).
32774 But how do we write a derivation that unpacks this tarball and adds it
32775 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
32776 derivation---the first one that gets built---uses @code{bash} as its
32777 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
32778 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
32779 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
32780 the Guix source distribution, whose sole purpose is to allow the Guile
32781 tarball to be unpacked.
32783 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
32784 Guile that can be used to run subsequent build programs. Its first task
32785 is to download tarballs containing the other pre-built binaries---this
32786 is what the @file{.tar.xz.drv} derivations do. Guix modules such as
32787 @code{ftp-client.scm} are used for this purpose. The
32788 @code{module-import.drv} derivations import those modules in a directory
32789 in the store, using the original layout. The
32790 @code{module-import-compiled.drv} derivations compile those modules, and
32791 write them in an output directory with the right layout. This
32792 corresponds to the @code{#:modules} argument of
32793 @code{build-expression->derivation} (@pxref{Derivations}).
32795 Finally, the various tarballs are unpacked by the derivations
32796 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
32797 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
32798 point we have a working C tool chain.
32800 @unnumberedsec Building the Build Tools
32802 Bootstrapping is complete when we have a full tool chain that does not
32803 depend on the pre-built bootstrap tools discussed above. This
32804 no-dependency requirement is verified by checking whether the files of
32805 the final tool chain contain references to the @file{/gnu/store}
32806 directories of the bootstrap inputs. The process that leads to this
32807 ``final'' tool chain is described by the package definitions found in
32808 the @code{(gnu packages commencement)} module.
32810 The @command{guix graph} command allows us to ``zoom out'' compared to
32811 the graph above, by looking at the level of package objects instead of
32812 individual derivations---remember that a package may translate to
32813 several derivations, typically one derivation to download its source,
32814 one to build the Guile modules it needs, and one to actually build the
32815 package from source. The command:
32818 guix graph -t bag \
32819 -e '(@@@@ (gnu packages commencement)
32820 glibc-final-with-bootstrap-bash)' | xdot -
32824 displays the dependency graph leading to the ``final'' C
32825 library@footnote{You may notice the @code{glibc-intermediate} label,
32826 suggesting that it is not @emph{quite} final, but as a good
32827 approximation, we will consider it final.}, depicted below.
32829 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
32831 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
32832 The first tool that gets built with the bootstrap binaries is
32833 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
32834 for all the following packages. From there Findutils and Diffutils get
32837 Then come the first-stage Binutils and GCC, built as pseudo cross
32838 tools---i.e., with @option{--target} equal to @option{--host}. They are
32839 used to build libc. Thanks to this cross-build trick, this libc is
32840 guaranteed not to hold any reference to the initial tool chain.
32842 From there the final Binutils and GCC (not shown above) are built. GCC
32843 uses @command{ld} from the final Binutils, and links programs against
32844 the just-built libc. This tool chain is used to build the other
32845 packages used by Guix and by the GNU Build System: Guile, Bash,
32848 And voilà! At this point we have the complete set of build tools that
32849 the GNU Build System expects. These are in the @code{%final-inputs}
32850 variable of the @code{(gnu packages commencement)} module, and are
32851 implicitly used by any package that uses @code{gnu-build-system}
32852 (@pxref{Build Systems, @code{gnu-build-system}}).
32855 @unnumberedsec Building the Bootstrap Binaries
32857 @cindex bootstrap binaries
32858 Because the final tool chain does not depend on the bootstrap binaries,
32859 those rarely need to be updated. Nevertheless, it is useful to have an
32860 automated way to produce them, should an update occur, and this is what
32861 the @code{(gnu packages make-bootstrap)} module provides.
32863 The following command builds the tarballs containing the bootstrap binaries
32864 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
32865 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
32866 and Guile, and a tarball containing a mixture of Coreutils and other basic
32867 command-line tools):
32870 guix build bootstrap-tarballs
32873 The generated tarballs are those that should be referred to in the
32874 @code{(gnu packages bootstrap)} module mentioned at the beginning of
32877 Still here? Then perhaps by now you've started to wonder: when do we
32878 reach a fixed point? That is an interesting question! The answer is
32879 unknown, but if you would like to investigate further (and have
32880 significant computational and storage resources to do so), then let us
32883 @unnumberedsec Reducing the Set of Bootstrap Binaries
32885 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
32886 binary code! Why is that a problem? It's a problem because these big chunks
32887 of binary code are practically non-auditable, which makes it hard to establish
32888 what source code produced them. Every unauditable binary also leaves us
32889 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
32890 paper @emph{Reflections on Trusting Trust}.
32892 This is mitigated by the fact that our bootstrap binaries were generated
32893 from an earlier Guix revision. Nevertheless it lacks the level of
32894 transparency that we get in the rest of the package dependency graph,
32895 where Guix always gives us a source-to-binary mapping. Thus, our goal
32896 is to reduce the set of bootstrap binaries to the bare minimum.
32898 The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
32899 on-going projects to do that. One of these is about replacing the
32900 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
32901 of increasing complexity, which could be built from source starting from
32902 a simple and auditable assembler.
32904 Our first major achievement is the replacement of of GCC, the GNU C Library
32905 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
32906 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
32907 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
32908 bootstrapped yet and thus we inject them as binary seeds. We call this the
32909 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
32910 binaries! Also, it has eliminated the C compiler binary; i686-linux and
32911 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
32913 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
32914 also looking at any other bootstrap binaries. Your help is welcome!
32917 @chapter Porting to a New Platform
32919 As discussed above, the GNU distribution is self-contained, and
32920 self-containment is achieved by relying on pre-built ``bootstrap
32921 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
32922 operating system kernel, CPU architecture, and application binary
32923 interface (ABI). Thus, to port the distribution to a platform that is
32924 not yet supported, one must build those bootstrap binaries, and update
32925 the @code{(gnu packages bootstrap)} module to use them on that platform.
32927 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
32928 When everything goes well, and assuming the GNU tool chain supports the
32929 target platform, this can be as simple as running a command like this
32933 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
32936 For this to work, the @code{glibc-dynamic-linker} procedure in
32937 @code{(gnu packages bootstrap)} must be augmented to return the right
32938 file name for libc's dynamic linker on that platform; likewise,
32939 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
32940 taught about the new platform.
32942 Once these are built, the @code{(gnu packages bootstrap)} module needs
32943 to be updated to refer to these binaries on the target platform. That
32944 is, the hashes and URLs of the bootstrap tarballs for the new platform
32945 must be added alongside those of the currently supported platforms. The
32946 bootstrap Guile tarball is treated specially: it is expected to be
32947 available locally, and @file{gnu/local.mk} has rules to download it for
32948 the supported architectures; a rule for the new platform must be added
32951 In practice, there may be some complications. First, it may be that the
32952 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
32953 above) is not recognized by all the GNU tools. Typically, glibc
32954 recognizes some of these, whereas GCC uses an extra @option{--with-abi}
32955 configure flag (see @code{gcc.scm} for examples of how to handle this).
32956 Second, some of the required packages could fail to build for that
32957 platform. Lastly, the generated binaries could be broken for some
32960 @c *********************************************************************
32961 @include contributing.texi
32963 @c *********************************************************************
32964 @node Acknowledgments
32965 @chapter Acknowledgments
32967 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
32968 which was designed and
32969 implemented by Eelco Dolstra, with contributions from other people (see
32970 the @file{nix/AUTHORS} file in Guix). Nix pioneered functional package
32971 management, and promoted unprecedented features, such as transactional
32972 package upgrades and rollbacks, per-user profiles, and referentially
32973 transparent build processes. Without this work, Guix would not exist.
32975 The Nix-based software distributions, Nixpkgs and NixOS, have also been
32976 an inspiration for Guix.
32978 GNU@tie{}Guix itself is a collective work with contributions from a
32979 number of people. See the @file{AUTHORS} file in Guix for more
32980 information on these fine people. The @file{THANKS} file lists people
32981 who have helped by reporting bugs, taking care of the infrastructure,
32982 providing artwork and themes, making suggestions, and more---thank you!
32985 @c *********************************************************************
32986 @node GNU Free Documentation License
32987 @appendix GNU Free Documentation License
32988 @cindex license, GNU Free Documentation License
32989 @include fdl-1.3.texi
32991 @c *********************************************************************
32992 @node Concept Index
32993 @unnumbered Concept Index
32996 @node Programming Index
32997 @unnumbered Programming Index
32998 @syncodeindex tp fn
32999 @syncodeindex vr fn
33004 @c Local Variables:
33005 @c ispell-local-dictionary: "american";