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, 2021 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, 2021 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, 2021 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, 2021 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@*
87 Copyright @copyright{} 2020 John Soo@*
88 Copyright @copyright{} 2020 Jonathan Brielmaier@*
90 Permission is granted to copy, distribute and/or modify this document
91 under the terms of the GNU Free Documentation License, Version 1.3 or
92 any later version published by the Free Software Foundation; with no
93 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
94 copy of the license is included in the section entitled ``GNU Free
95 Documentation License''.
98 @dircategory System administration
100 * Guix: (guix). Manage installed software and system configuration.
101 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
102 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
103 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
104 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
105 * guix deploy: (guix)Invoking guix deploy. Manage operating system configurations for remote hosts.
108 @dircategory Software development
110 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
111 * guix build: (guix)Invoking guix build. Building packages.
112 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
116 @title GNU Guix Reference Manual
117 @subtitle Using the GNU Guix Functional Package Manager
118 @author The GNU Guix Developers
121 @vskip 0pt plus 1filll
122 Edition @value{EDITION} @*
130 @c *********************************************************************
134 This document describes GNU Guix version @value{VERSION}, a functional
135 package management tool written for the GNU system.
137 @c TRANSLATORS: You can replace the following paragraph with information on
138 @c how to join your own translation team and how to report issues with the
140 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
141 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
142 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
143 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
144 Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
145 would like to translate it in your native language, consider joining
146 @uref{https://translate.fedoraproject.org/projects/guix/documentation-manual,
150 * Introduction:: What is Guix about?
151 * Installation:: Installing Guix.
152 * System Installation:: Installing the whole operating system.
153 * Getting Started:: Your first steps.
154 * Package Management:: Package installation, upgrade, etc.
155 * Channels:: Customizing the package collection.
156 * Development:: Guix-aided software development.
157 * Programming Interface:: Using Guix in Scheme.
158 * Utilities:: Package management commands.
159 * System Configuration:: Configuring the operating system.
160 * Documentation:: Browsing software user manuals.
161 * Installing Debugging Files:: Feeding the debugger.
162 * Security Updates:: Deploying security fixes quickly.
163 * Bootstrapping:: GNU/Linux built from scratch.
164 * Porting:: Targeting another platform or kernel.
165 * Contributing:: Your help needed!
167 * Acknowledgments:: Thanks!
168 * GNU Free Documentation License:: The license of this manual.
169 * Concept Index:: Concepts.
170 * Programming Index:: Data types, functions, and variables.
173 --- The Detailed Node Listing ---
177 * Managing Software the Guix Way:: What's special.
178 * GNU Distribution:: The packages and tools.
182 * Binary Installation:: Getting Guix running in no time!
183 * Requirements:: Software needed to build and run Guix.
184 * Running the Test Suite:: Testing Guix.
185 * Setting Up the Daemon:: Preparing the build daemon's environment.
186 * Invoking guix-daemon:: Running the build daemon.
187 * Application Setup:: Application-specific setup.
188 * Upgrading Guix:: Upgrading Guix and its build daemon.
190 Setting Up the Daemon
192 * Build Environment Setup:: Preparing the isolated build environment.
193 * Daemon Offload Setup:: Offloading builds to remote machines.
194 * SELinux Support:: Using an SELinux policy for the daemon.
198 * Limitations:: What you can expect.
199 * Hardware Considerations:: Supported hardware.
200 * USB Stick and DVD Installation:: Preparing the installation medium.
201 * Preparing for Installation:: Networking, partitioning, etc.
202 * Guided Graphical Installation:: Easy graphical installation.
203 * Manual Installation:: Manual installation for wizards.
204 * After System Installation:: When installation succeeded.
205 * Installing Guix in a VM:: Guix System playground.
206 * Building the Installation Image:: How this comes to be.
210 * Keyboard Layout and Networking and Partitioning:: Initial setup.
211 * Proceeding with the Installation:: Installing.
215 * Features:: How Guix will make your life brighter.
216 * Invoking guix package:: Package installation, removal, etc.
217 * Substitutes:: Downloading pre-built binaries.
218 * Packages with Multiple Outputs:: Single source package, multiple outputs.
219 * Invoking guix gc:: Running the garbage collector.
220 * Invoking guix pull:: Fetching the latest Guix and distribution.
221 * Invoking guix time-machine:: Running an older revision of Guix.
222 * Inferiors:: Interacting with another revision of Guix.
223 * Invoking guix describe:: Display information about your Guix revision.
224 * Invoking guix archive:: Exporting and importing store files.
228 * Official Substitute Server:: One particular source of substitutes.
229 * Substitute Server Authorization:: How to enable or disable substitutes.
230 * Getting Substitutes from Other Servers:: Substitute diversity.
231 * Substitute Authentication:: How Guix verifies substitutes.
232 * Proxy Settings:: How to get substitutes via proxy.
233 * Substitution Failure:: What happens when substitution fails.
234 * On Trusting Binaries:: How can you trust that binary blob?
238 * Specifying Additional Channels:: Extending the package collection.
239 * Using a Custom Guix Channel:: Using a customized Guix.
240 * Replicating Guix:: Running the @emph{exact same} Guix.
241 * Channel Authentication:: How Guix verifies what it fetches.
242 * Creating a Channel:: How to write your custom channel.
243 * Package Modules in a Sub-directory:: Specifying the channel's package modules location.
244 * Declaring Channel Dependencies:: How to depend on other channels.
245 * Specifying Channel Authorizations:: Defining channel authors authorizations.
246 * Primary URL:: Distinguishing mirror to original.
247 * Writing Channel News:: Communicating information to channel's users.
248 * Channels with Substitutes:: Using channels with available substitutes.
252 * Invoking guix environment:: Setting up development environments.
253 * Invoking guix pack:: Creating software bundles.
254 * The GCC toolchain:: Working with languages supported by GCC.
255 * Invoking guix git authenticate:: Authenticating Git repositories.
257 Programming Interface
259 * Package Modules:: Packages from the programmer's viewpoint.
260 * Defining Packages:: Defining new packages.
261 * Defining Package Variants:: Customizing packages.
262 * Build Systems:: Specifying how packages are built.
263 * Build Phases:: Phases of the build process of a package.
264 * Build Utilities:: Helpers for your package definitions and more.
265 * The Store:: Manipulating the package store.
266 * Derivations:: Low-level interface to package derivations.
267 * The Store Monad:: Purely functional interface to the store.
268 * G-Expressions:: Manipulating build expressions.
269 * Invoking guix repl:: Programming Guix in Guile.
273 * package Reference:: The package data type.
274 * origin Reference:: The origin data type.
278 * Invoking guix build:: Building packages from the command line.
279 * Invoking guix edit:: Editing package definitions.
280 * Invoking guix download:: Downloading a file and printing its hash.
281 * Invoking guix hash:: Computing the cryptographic hash of a file.
282 * Invoking guix import:: Importing package definitions.
283 * Invoking guix refresh:: Updating package definitions.
284 * Invoking guix lint:: Finding errors in package definitions.
285 * Invoking guix size:: Profiling disk usage.
286 * Invoking guix graph:: Visualizing the graph of packages.
287 * Invoking guix publish:: Sharing substitutes.
288 * Invoking guix challenge:: Challenging substitute servers.
289 * Invoking guix copy:: Copying to and from a remote store.
290 * Invoking guix container:: Process isolation.
291 * Invoking guix weather:: Assessing substitute availability.
292 * Invoking guix processes:: Listing client processes.
294 Invoking @command{guix build}
296 * Common Build Options:: Build options for most commands.
297 * Package Transformation Options:: Creating variants of packages.
298 * Additional Build Options:: Options specific to 'guix build'.
299 * Debugging Build Failures:: Real life packaging experience.
303 * Using the Configuration System:: Customizing your GNU system.
304 * operating-system Reference:: Detail of operating-system declarations.
305 * File Systems:: Configuring file system mounts.
306 * Mapped Devices:: Block device extra processing.
307 * User Accounts:: Specifying user accounts.
308 * Keyboard Layout:: How the system interprets key strokes.
309 * Locales:: Language and cultural convention settings.
310 * Services:: Specifying system services.
311 * Setuid Programs:: Programs running with root privileges.
312 * X.509 Certificates:: Authenticating HTTPS servers.
313 * Name Service Switch:: Configuring libc's name service switch.
314 * Initial RAM Disk:: Linux-Libre bootstrapping.
315 * Bootloader Configuration:: Configuring the boot loader.
316 * Invoking guix system:: Instantiating a system configuration.
317 * Invoking guix deploy:: Deploying a system configuration to a remote host.
318 * Running Guix in a VM:: How to run Guix System in a virtual machine.
319 * Defining Services:: Adding new service definitions.
323 * Base Services:: Essential system services.
324 * Scheduled Job Execution:: The mcron service.
325 * Log Rotation:: The rottlog service.
326 * Networking Services:: Network setup, SSH daemon, etc.
327 * Unattended Upgrades:: Automated system upgrades.
328 * X Window:: Graphical display.
329 * Printing Services:: Local and remote printer support.
330 * Desktop Services:: D-Bus and desktop services.
331 * Sound Services:: ALSA and Pulseaudio services.
332 * Database Services:: SQL databases, key-value stores, etc.
333 * Mail Services:: IMAP, POP3, SMTP, and all that.
334 * Messaging Services:: Messaging services.
335 * Telephony Services:: Telephony services.
336 * Monitoring Services:: Monitoring services.
337 * Kerberos Services:: Kerberos services.
338 * LDAP Services:: LDAP services.
339 * Web Services:: Web servers.
340 * Certificate Services:: TLS certificates via Let's Encrypt.
341 * DNS Services:: DNS daemons.
342 * VPN Services:: VPN daemons.
343 * Network File System:: NFS related services.
344 * Continuous Integration:: The Cuirass service.
345 * Power Management Services:: Extending battery life.
346 * Audio Services:: The MPD.
347 * Virtualization Services:: Virtualization services.
348 * Version Control Services:: Providing remote access to Git repositories.
349 * Game Services:: Game servers.
350 * PAM Mount Service:: Service to mount volumes when logging in.
351 * Guix Services:: Services relating specifically to Guix.
352 * Linux Services:: Services tied to the Linux kernel.
353 * Hurd Services:: Services specific for a Hurd System.
354 * Miscellaneous Services:: Other services.
358 * Service Composition:: The model for composing services.
359 * Service Types and Services:: Types and services.
360 * Service Reference:: API reference.
361 * Shepherd Services:: A particular type of service.
363 Installing Debugging Files
365 * Separate Debug Info:: Installing 'debug' outputs.
366 * Rebuilding Debug Info:: Building missing debug info.
370 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
371 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
376 @c *********************************************************************
378 @chapter Introduction
381 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
382 using the international phonetic alphabet (IPA).} is a package
383 management tool for and distribution of the GNU system.
384 Guix makes it easy for unprivileged
385 users to install, upgrade, or remove software packages, to roll back to a
386 previous package set, to build packages from source, and generally
387 assists with the creation and maintenance of software environments.
390 @cindex GuixSD, now Guix System
391 @cindex Guix System Distribution, now Guix System
392 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
393 complements the available tools without interference (@pxref{Installation}),
394 or you can use it as a standalone operating system distribution,
395 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
396 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
397 group everything under the ``Guix'' banner since, after all, Guix System is
398 readily available through the @command{guix system} command, even if you're
399 using a different distro underneath!}. @xref{GNU Distribution}.
402 * Managing Software the Guix Way:: What's special.
403 * GNU Distribution:: The packages and tools.
406 @node Managing Software the Guix Way
407 @section Managing Software the Guix Way
409 @cindex user interfaces
410 Guix provides a command-line package management interface
411 (@pxref{Package Management}), tools to help with software development
412 (@pxref{Development}), command-line utilities for more advanced usage
413 (@pxref{Utilities}), as well as Scheme programming interfaces
414 (@pxref{Programming Interface}).
416 Its @dfn{build daemon} is responsible for building packages on behalf of
417 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
418 binaries from authorized sources (@pxref{Substitutes}).
420 @cindex extensibility of the distribution
421 @cindex customization, of packages
422 Guix includes package definitions for many GNU and non-GNU packages, all
423 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
424 user's computing freedom}. It is @emph{extensible}: users can write
425 their own package definitions (@pxref{Defining Packages}) and make them
426 available as independent package modules (@pxref{Package Modules}). It
427 is also @emph{customizable}: users can @emph{derive} specialized package
428 definitions from existing ones, including from the command line
429 (@pxref{Package Transformation Options}).
431 @cindex functional package management
433 Under the hood, Guix implements the @dfn{functional package management}
434 discipline pioneered by Nix (@pxref{Acknowledgments}).
435 In Guix, the package build and installation process is seen
436 as a @emph{function}, in the mathematical sense. That function takes inputs,
437 such as build scripts, a compiler, and libraries, and
438 returns an installed package. As a pure function, its result depends
439 solely on its inputs---for instance, it cannot refer to software or
440 scripts that were not explicitly passed as inputs. A build function
441 always produces the same result when passed a given set of inputs. It
442 cannot alter the environment of the running system in
443 any way; for instance, it cannot create, modify, or delete files outside
444 of its build and installation directories. This is achieved by running
445 build processes in isolated environments (or @dfn{containers}), where only their
446 explicit inputs are visible.
449 The result of package build functions is @dfn{cached} in the file
450 system, in a special directory called @dfn{the store} (@pxref{The
451 Store}). Each package is installed in a directory of its own in the
452 store---by default under @file{/gnu/store}. The directory name contains
453 a hash of all the inputs used to build that package; thus, changing an
454 input yields a different directory name.
456 This approach is the foundation for the salient features of Guix: support
457 for transactional package upgrade and rollback, per-user installation, and
458 garbage collection of packages (@pxref{Features}).
461 @node GNU Distribution
462 @section GNU Distribution
465 Guix comes with a distribution of the GNU system consisting entirely of
466 free software@footnote{The term ``free'' here refers to the
467 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
468 users of that software}.}. The
469 distribution can be installed on its own (@pxref{System Installation}),
470 but it is also possible to install Guix as a package manager on top of
471 an installed GNU/Linux system (@pxref{Installation}). When we need to
472 distinguish between the two, we refer to the standalone distribution as
475 The distribution provides core GNU packages such as GNU libc, GCC, and
476 Binutils, as well as many GNU and non-GNU applications. The complete
477 list of available packages can be browsed
478 @url{https://www.gnu.org/software/guix/packages,on-line} or by
479 running @command{guix package} (@pxref{Invoking guix package}):
482 guix package --list-available
485 Our goal is to provide a practical 100% free software distribution of
486 Linux-based and other variants of GNU, with a focus on the promotion and
487 tight integration of GNU components, and an emphasis on programs and
488 tools that help users exert that freedom.
490 Packages are currently available on the following platforms:
495 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel.
498 Intel 32-bit architecture (IA32), Linux-Libre kernel.
501 ARMv7-A architecture with hard float, Thumb-2 and NEON,
502 using the EABI hard-float application binary interface (ABI),
503 and Linux-Libre kernel.
506 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
509 @uref{https://hurd.gnu.org, GNU/Hurd} on the Intel 32-bit architecture
512 This configuration is experimental and under development. The easiest
513 way for you to give it a try is by setting up an instance of
514 @code{hurd-vm-service-type} on your GNU/Linux machine
515 (@pxref{transparent-emulation-qemu, @code{hurd-vm-service-type}}).
516 @xref{Contributing}, on how to help!
518 @item mips64el-linux (deprecated)
519 little-endian 64-bit MIPS processors, specifically the Loongson series,
520 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
521 supported; in particular, there is no ongoing work to ensure that this
522 architecture still works. Should someone decide they wish to revive this
523 architecture then the code is still available.
527 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
528 configuration and Guix takes care of instantiating the configuration in a
529 transactional, reproducible, and stateless fashion (@pxref{System
530 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
531 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
532 Manual}), the well-known GNU utilities and tool chain, as well as the
533 graphical environment or system services of your choice.
535 Guix System is available on all the above platforms except
536 @code{mips64el-linux}.
539 For information on porting to other architectures or kernels,
542 Building this distribution is a cooperative effort, and you are invited
543 to join! @xref{Contributing}, for information about how you can help.
546 @c *********************************************************************
548 @chapter Installation
550 @cindex installing Guix
553 We recommend the use of this
554 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
555 shell installer script} to install Guix on top of a running GNU/Linux system,
556 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
557 with the installation of the package manager, which can be done on top of a
558 running GNU/Linux system. If, instead, you want to install the complete GNU
559 operating system, @pxref{System Installation}.} The script automates the
560 download, installation, and initial configuration of Guix. It should be run
564 @cindex foreign distro
565 @cindex directories related to foreign distro
566 When installed on a foreign distro, GNU@tie{}Guix complements the available
567 tools without interference. Its data lives exclusively in two directories,
568 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
569 such as @file{/etc}, are left untouched.
571 Once installed, Guix can be updated by running @command{guix pull}
572 (@pxref{Invoking guix pull}).
574 If you prefer to perform the installation steps manually or want to tweak
575 them, you may find the following subsections useful. They describe the
576 software requirements of Guix, as well as how to install it manually and get
580 * Binary Installation:: Getting Guix running in no time!
581 * Requirements:: Software needed to build and run Guix.
582 * Running the Test Suite:: Testing Guix.
583 * Setting Up the Daemon:: Preparing the build daemon's environment.
584 * Invoking guix-daemon:: Running the build daemon.
585 * Application Setup:: Application-specific setup.
586 * Upgrading Guix:: Upgrading Guix and its build daemon.
589 @node Binary Installation
590 @section Binary Installation
592 @cindex installing Guix from binaries
593 @cindex installer script
594 This section describes how to install Guix on an arbitrary system from a
595 self-contained tarball providing binaries for Guix and for all its
596 dependencies. This is often quicker than installing from source, which
597 is described in the next sections. The only requirement is to have
600 @c Note duplicated from the ``Installation'' node.
602 We recommend the use of this
603 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
604 shell installer script}. The script automates the download, installation, and
605 initial configuration steps described below. It should be run as the root
606 user. As root, you can thus run this:
610 wget https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh
611 chmod +x guix-install.sh
615 When you're done, @pxref{Application Setup} for extra configuration you
616 might need, and @ref{Getting Started} for your first steps!
619 Installing goes along these lines:
623 @cindex downloading Guix binary
624 Download the binary tarball from
625 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz},
626 where @code{x86_64-linux} can be replaced with @code{i686-linux} for an
627 @code{i686} (32-bits) machine already running the kernel Linux, and so on
628 (@pxref{GNU Distribution}).
630 @c The following is somewhat duplicated in ``System Installation''.
631 Make sure to download the associated @file{.sig} file and to verify the
632 authenticity of the tarball against it, along these lines:
635 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
636 $ gpg --verify guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
639 If that command fails because you do not have the required public key,
640 then run this command to import it:
643 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
644 -qO - | gpg --import -
648 and rerun the @code{gpg --verify} command.
650 Take note that a warning like ``This key is not certified with a trusted
651 signature!'' is normal.
653 @c end authentication part
656 Now, you need to become the @code{root} user. Depending on your distribution,
657 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
661 # tar --warning=no-timestamp -xf \
662 /path/to/guix-binary-@value{VERSION}.x86_64-linux.tar.xz
663 # mv var/guix /var/ && mv gnu /
666 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
667 The latter contains a ready-to-use profile for @code{root} (see next
670 Do @emph{not} unpack the tarball on a working Guix system since that
671 would overwrite its own essential files.
673 The @option{--warning=no-timestamp} option makes sure GNU@tie{}tar does
674 not emit warnings about ``implausibly old time stamps'' (such
675 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
677 They stem from the fact that all the
678 files in the archive have their modification time set to 1 (which
679 means January 1st, 1970). This is done on purpose to make sure the
680 archive content is independent of its creation time, thus making it
684 Make the profile available under @file{~root/.config/guix/current}, which is
685 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
688 # mkdir -p ~root/.config/guix
689 # ln -sf /var/guix/profiles/per-user/root/current-guix \
690 ~root/.config/guix/current
693 Source @file{etc/profile} to augment @env{PATH} and other relevant
694 environment variables:
697 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
698 source $GUIX_PROFILE/etc/profile
702 Create the group and user accounts for build users as explained below
703 (@pxref{Build Environment Setup}).
706 Run the daemon, and set it to automatically start on boot.
708 If your host distro uses the systemd init system, this can be achieved
711 @c Versions of systemd that supported symlinked service files are not
712 @c yet widely deployed, so we should suggest that users copy the service
715 @c See this thread for more information:
716 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
719 # cp ~root/.config/guix/current/lib/systemd/system/gnu-store.mount \
720 ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
722 # systemctl enable --now gnu-store.mount guix-daemon
725 If your host distro uses the Upstart init system:
728 # initctl reload-configuration
729 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
734 Otherwise, you can still start the daemon manually with:
737 # ~root/.config/guix/current/bin/guix-daemon \
738 --build-users-group=guixbuild
742 Make the @command{guix} command available to other users on the machine,
746 # mkdir -p /usr/local/bin
748 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
751 It is also a good idea to make the Info version of this manual available
755 # mkdir -p /usr/local/share/info
756 # cd /usr/local/share/info
757 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
761 That way, assuming @file{/usr/local/share/info} is in the search path,
762 running @command{info guix} will open this manual (@pxref{Other Info
763 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
767 @cindex substitutes, authorization thereof
768 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
769 (@pxref{Substitutes}), authorize them:
772 # guix archive --authorize < \
773 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
777 Each user may need to perform a few additional steps to make their Guix
778 environment ready for use, @pxref{Application Setup}.
781 Voilà, the installation is complete!
783 You can confirm that Guix is working by installing a sample package into
790 The binary installation tarball can be (re)produced and verified simply
791 by running the following command in the Guix source tree:
794 make guix-binary.@var{system}.tar.xz
798 ...@: which, in turn, runs:
801 guix pack -s @var{system} --localstatedir \
802 --profile-name=current-guix guix
805 @xref{Invoking guix pack}, for more info on this handy tool.
808 @section Requirements
810 This section lists requirements when building Guix from source. The
811 build procedure for Guix is the same as for other GNU software, and is
812 not covered here. Please see the files @file{README} and @file{INSTALL}
813 in the Guix source tree for additional details.
815 @cindex official website
816 GNU Guix is available for download from its website at
817 @url{https://www.gnu.org/software/guix/}.
819 GNU Guix depends on the following packages:
822 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 3.0.x or
824 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
827 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
828 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
829 Guile,, gnutls-guile, GnuTLS-Guile});
831 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
833 @item @uref{https://notabug.org/guile-zlib/guile-zlib, Guile-zlib};
834 @item @uref{https://notabug.org/guile-lzlib/guile-lzlib, Guile-lzlib};
835 @item @uref{https://www.nongnu.org/guile-avahi/, Guile-Avahi};
837 @c FIXME: Specify a version number once a release has been made.
838 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, version 0.3.0
840 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON}
842 @item @url{https://www.gnu.org/software/make/, GNU Make}.
845 The following dependencies are optional:
849 @c Note: We need at least 0.13.0 for #:nodelay.
850 Support for build offloading (@pxref{Daemon Offload Setup}) and
851 @command{guix copy} (@pxref{Invoking guix copy}) depends on
852 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
853 version 0.13.0 or later.
856 @uref{https://notabug.org/guile-zstd/guile-zstd, Guile-zstd}, for zstd
857 compression and decompression in @command{guix publish} and for
858 substitutes (@pxref{Invoking guix publish}).
861 @uref{https://ngyro.com/software/guile-semver.html, Guile-Semver} for
862 the @code{crate} importer (@pxref{Invoking guix import}).
865 When @url{http://www.bzip.org, libbz2} is available,
866 @command{guix-daemon} can use it to compress build logs.
869 Unless @option{--disable-daemon} was passed to @command{configure}, the
870 following packages are also needed:
873 @item @url{https://gnupg.org/, GNU libgcrypt};
874 @item @url{https://sqlite.org, SQLite 3};
875 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
879 @cindex state directory
880 When configuring Guix on a system that already has a Guix installation,
881 be sure to specify the same state directory as the existing installation
882 using the @option{--localstatedir} option of the @command{configure}
883 script (@pxref{Directory Variables, @code{localstatedir},, standards,
884 GNU Coding Standards}). Usually, this @var{localstatedir} option is
885 set to the value @file{/var}. The @command{configure} script protects
886 against unintended misconfiguration of @var{localstatedir} so you do not
887 inadvertently corrupt your store (@pxref{The Store}).
889 @node Running the Test Suite
890 @section Running the Test Suite
893 After a successful @command{configure} and @code{make} run, it is a good
894 idea to run the test suite. It can help catch issues with the setup or
895 environment, or bugs in Guix itself---and really, reporting test
896 failures is a good way to help improve the software. To run the test
903 Test cases can run in parallel: you can use the @code{-j} option of
904 GNU@tie{}make to speed things up. The first run may take a few minutes
905 on a recent machine; subsequent runs will be faster because the store
906 that is created for test purposes will already have various things in
909 It is also possible to run a subset of the tests by defining the
910 @code{TESTS} makefile variable as in this example:
913 make check TESTS="tests/store.scm tests/cpio.scm"
916 By default, tests results are displayed at a file level. In order to
917 see the details of every individual test cases, it is possible to define
918 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
921 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
924 The underlying SRFI 64 custom Automake test driver used for the 'check'
925 test suite (located at @file{build-aux/test-driver.scm}) also allows
926 selecting which test cases to run at a finer level, via its
927 @option{--select} and @option{--exclude} options. Here's an example, to
928 run all the test cases from the @file{tests/packages.scm} test file
929 whose names start with ``transaction-upgrade-entry'':
932 export SCM_LOG_DRIVER_FLAGS="--select=^transaction-upgrade-entry"
933 make check TESTS="tests/packages.scm"
936 Those wishing to inspect the results of failed tests directly from the
937 command line can add the @option{--errors-only=yes} option to the
938 @code{SCM_LOG_DRIVER_FLAGS} makefile variable and set the @code{VERBOSE}
939 Automake makefile variable, as in:
942 make check SCM_LOG_DRIVER_FLAGS="--brief=no --errors-only=yes" VERBOSE=1
945 The @option{--show-duration=yes} option can be used to print the
946 duration of the individual test cases, when used in combination with
950 make check SCM_LOG_DRIVER_FLAGS="--brief=no --show-duration=yes"
953 @xref{Parallel Test Harness,,,automake,GNU Automake} for more
954 information about the Automake Parallel Test Harness.
956 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
957 @file{test-suite.log} file. Please specify the Guix version being used
958 as well as version numbers of the dependencies (@pxref{Requirements}) in
961 Guix also comes with a whole-system test suite that tests complete
962 Guix System instances. It can only run on systems where
963 Guix is already installed, using:
970 or, again, by defining @code{TESTS} to select a subset of tests to run:
973 make check-system TESTS="basic mcron"
976 These system tests are defined in the @code{(gnu tests @dots{})}
977 modules. They work by running the operating systems under test with
978 lightweight instrumentation in a virtual machine (VM). They can be
979 computationally intensive or rather cheap, depending on whether
980 substitutes are available for their dependencies (@pxref{Substitutes}).
981 Some of them require a lot of storage space to hold VM images.
983 Again in case of test failures, please send @email{bug-guix@@gnu.org}
986 @node Setting Up the Daemon
987 @section Setting Up the Daemon
990 Operations such as building a package or running the garbage collector
991 are all performed by a specialized process, the @dfn{build daemon}, on
992 behalf of clients. Only the daemon may access the store and its
993 associated database. Thus, any operation that manipulates the store
994 goes through the daemon. For instance, command-line tools such as
995 @command{guix package} and @command{guix build} communicate with the
996 daemon (@i{via} remote procedure calls) to instruct it what to do.
998 The following sections explain how to prepare the build daemon's
999 environment. See also @ref{Substitutes}, for information on how to allow
1000 the daemon to download pre-built binaries.
1003 * Build Environment Setup:: Preparing the isolated build environment.
1004 * Daemon Offload Setup:: Offloading builds to remote machines.
1005 * SELinux Support:: Using an SELinux policy for the daemon.
1008 @node Build Environment Setup
1009 @subsection Build Environment Setup
1011 @cindex build environment
1012 In a standard multi-user setup, Guix and its daemon---the
1013 @command{guix-daemon} program---are installed by the system
1014 administrator; @file{/gnu/store} is owned by @code{root} and
1015 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
1016 Guix tools to build packages or otherwise access the store, and the
1017 daemon will do it on their behalf, ensuring that the store is kept in a
1018 consistent state, and allowing built packages to be shared among users.
1021 When @command{guix-daemon} runs as @code{root}, you may not want package
1022 build processes themselves to run as @code{root} too, for obvious
1023 security reasons. To avoid that, a special pool of @dfn{build users}
1024 should be created for use by build processes started by the daemon.
1025 These build users need not have a shell and a home directory: they will
1026 just be used when the daemon drops @code{root} privileges in build
1027 processes. Having several such users allows the daemon to launch
1028 distinct build processes under separate UIDs, which guarantees that they
1029 do not interfere with each other---an essential feature since builds are
1030 regarded as pure functions (@pxref{Introduction}).
1032 On a GNU/Linux system, a build user pool may be created like this (using
1033 Bash syntax and the @code{shadow} commands):
1035 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
1036 @c for why `-G' is needed.
1038 # groupadd --system guixbuild
1039 # for i in `seq -w 1 10`;
1041 useradd -g guixbuild -G guixbuild \
1042 -d /var/empty -s `which nologin` \
1043 -c "Guix build user $i" --system \
1049 The number of build users determines how many build jobs may run in
1050 parallel, as specified by the @option{--max-jobs} option
1051 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
1052 @command{guix system vm} and related commands, you may need to add the
1053 build users to the @code{kvm} group so they can access @file{/dev/kvm},
1054 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
1055 (@pxref{Invoking guix system}).
1057 The @code{guix-daemon} program may then be run as @code{root} with the
1058 following command@footnote{If your machine uses the systemd init system,
1059 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
1060 file in @file{/etc/systemd/system} will ensure that
1061 @command{guix-daemon} is automatically started. Similarly, if your
1062 machine uses the Upstart init system, drop the
1063 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
1064 file in @file{/etc/init}.}:
1067 # guix-daemon --build-users-group=guixbuild
1072 This way, the daemon starts build processes in a chroot, under one of
1073 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
1074 environment contains nothing but:
1076 @c Keep this list in sync with libstore/build.cc! -----------------------
1079 a minimal @code{/dev} directory, created mostly independently from the
1080 host @code{/dev}@footnote{``Mostly'', because while the set of files
1081 that appear in the chroot's @code{/dev} is fixed, most of these files
1082 can only be created if the host has them.};
1085 the @code{/proc} directory; it only shows the processes of the container
1086 since a separate PID name space is used;
1089 @file{/etc/passwd} with an entry for the current user and an entry for
1093 @file{/etc/group} with an entry for the user's group;
1096 @file{/etc/hosts} with an entry that maps @code{localhost} to
1100 a writable @file{/tmp} directory.
1103 You can influence the directory where the daemon stores build trees
1104 @i{via} the @env{TMPDIR} environment variable. However, the build tree
1105 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
1106 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
1107 This way, the value of @env{TMPDIR} does not leak inside build
1108 environments, which avoids discrepancies in cases where build processes
1109 capture the name of their build tree.
1113 The daemon also honors the @env{http_proxy} and @env{https_proxy}
1114 environment variables for HTTP and HTTPS downloads it performs, be it
1115 for fixed-output derivations (@pxref{Derivations}) or for substitutes
1116 (@pxref{Substitutes}).
1118 If you are installing Guix as an unprivileged user, it is still possible
1119 to run @command{guix-daemon} provided you pass @option{--disable-chroot}.
1120 However, build processes will not be isolated from one another, and not
1121 from the rest of the system. Thus, build processes may interfere with
1122 each other, and may access programs, libraries, and other files
1123 available on the system---making it much harder to view them as
1124 @emph{pure} functions.
1127 @node Daemon Offload Setup
1128 @subsection Using the Offload Facility
1132 When desired, the build daemon can @dfn{offload} derivation builds to
1133 other machines running Guix, using the @code{offload} @dfn{build
1134 hook}@footnote{This feature is available only when
1135 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1136 present.}. When that feature is enabled, a list of user-specified build
1137 machines is read from @file{/etc/guix/machines.scm}; every time a build
1138 is requested, for instance via @code{guix build}, the daemon attempts to
1139 offload it to one of the machines that satisfy the constraints of the
1140 derivation, in particular its system types---e.g., @code{x86_64-linux}.
1141 A single machine can have multiple system types, either because its
1142 architecture natively supports it, via emulation
1143 (@pxref{transparent-emulation-qemu, Transparent Emulation with QEMU}),
1144 or both. Missing prerequisites for the build are
1145 copied over SSH to the target machine, which then proceeds with the
1146 build; upon success the output(s) of the build are copied back to the
1147 initial machine. The offload facility comes with a basic scheduler that
1148 attempts to select the best machine. The best machine is chosen among
1149 the available machines based on criteria such as:
1153 The availability of a build slot. A build machine can have as many
1154 build slots (connections) as the value of the @code{parallel-builds}
1155 field of its @code{build-machine} object.
1158 Its relative speed, as defined via the @code{speed} field of its
1159 @code{build-machine} object.
1162 Its load. The normalized machine load must be lower than a threshold
1163 value, configurable via the @code{overload-threshold} field of its
1164 @code{build-machine} object.
1167 Disk space availability. More than a 100 MiB must be available.
1170 The @file{/etc/guix/machines.scm} file typically looks like this:
1173 (list (build-machine
1174 (name "eightysix.example.org")
1175 (systems (list "x86_64-linux" "i686-linux"))
1176 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1178 (speed 2.)) ;incredibly fast!
1181 (name "armeight.example.org")
1182 (systems (list "aarch64-linux"))
1183 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1186 (string-append (getenv "HOME")
1187 "/.ssh/identity-for-guix"))))
1191 In the example above we specify a list of two build machines, one for
1192 the @code{x86_64} and @code{i686} architectures and one for the
1193 @code{aarch64} architecture.
1195 In fact, this file is---not surprisingly!---a Scheme file that is
1196 evaluated when the @code{offload} hook is started. Its return value
1197 must be a list of @code{build-machine} objects. While this example
1198 shows a fixed list of build machines, one could imagine, say, using
1199 DNS-SD to return a list of potential build machines discovered in the
1200 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1201 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1204 @deftp {Data Type} build-machine
1205 This data type represents build machines to which the daemon may offload
1206 builds. The important fields are:
1211 The host name of the remote machine.
1214 The system types the remote machine supports---e.g., @code{(list
1215 "x86_64-linux" "i686-linux")}.
1218 The user account to use when connecting to the remote machine over SSH.
1219 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1220 allow non-interactive logins.
1223 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1224 This is used to authenticate the machine when we connect to it. It is a
1225 long string that looks like this:
1228 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1231 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1232 key can be found in a file such as
1233 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1235 If the machine is running the SSH daemon of GNU@tie{}lsh,
1236 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1237 similar file. It can be converted to the OpenSSH format using
1238 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1241 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1242 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1247 A number of optional fields may be specified:
1251 @item @code{port} (default: @code{22})
1252 Port number of SSH server on the machine.
1254 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1255 The SSH private key file to use when connecting to the machine, in
1256 OpenSSH format. This key must not be protected with a passphrase.
1258 Note that the default value is the private key @emph{of the root
1259 account}. Make sure it exists if you use the default.
1261 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1262 @itemx @code{compression-level} (default: @code{3})
1263 The SSH-level compression methods and compression level requested.
1265 Note that offloading relies on SSH compression to reduce bandwidth usage
1266 when transferring files to and from build machines.
1268 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1269 File name of the Unix-domain socket @command{guix-daemon} is listening
1272 @item @code{overload-threshold} (default: @code{0.6})
1273 The load threshold above which a potential offload machine is
1274 disregarded by the offload scheduler. The value roughly translates to
1275 the total processor usage of the build machine, ranging from 0.0 (0%) to
1276 1.0 (100%). It can also be disabled by setting
1277 @code{overload-threshold} to @code{#f}.
1279 @item @code{parallel-builds} (default: @code{1})
1280 The number of builds that may run in parallel on the machine.
1282 @item @code{speed} (default: @code{1.0})
1283 A ``relative speed factor''. The offload scheduler will tend to prefer
1284 machines with a higher speed factor.
1286 @item @code{features} (default: @code{'()})
1287 A list of strings denoting specific features supported by the machine.
1288 An example is @code{"kvm"} for machines that have the KVM Linux modules
1289 and corresponding hardware support. Derivations can request features by
1290 name, and they will be scheduled on matching build machines.
1295 The @command{guix} command must be in the search path on the build
1296 machines. You can check whether this is the case by running:
1299 ssh build-machine guix repl --version
1302 There is one last thing to do once @file{machines.scm} is in place. As
1303 explained above, when offloading, files are transferred back and forth
1304 between the machine stores. For this to work, you first need to
1305 generate a key pair on each machine to allow the daemon to export signed
1306 archives of files from the store (@pxref{Invoking guix archive}):
1309 # guix archive --generate-key
1313 Each build machine must authorize the key of the master machine so that
1314 it accepts store items it receives from the master:
1317 # guix archive --authorize < master-public-key.txt
1321 Likewise, the master machine must authorize the key of each build machine.
1323 All the fuss with keys is here to express pairwise mutual trust
1324 relations between the master and the build machines. Concretely, when
1325 the master receives files from a build machine (and @i{vice versa}), its
1326 build daemon can make sure they are genuine, have not been tampered
1327 with, and that they are signed by an authorized key.
1329 @cindex offload test
1330 To test whether your setup is operational, run this command on the
1337 This will attempt to connect to each of the build machines specified in
1338 @file{/etc/guix/machines.scm}, make sure Guix is
1339 available on each machine, attempt to export to the machine and import
1340 from it, and report any error in the process.
1342 If you want to test a different machine file, just specify it on the
1346 # guix offload test machines-qualif.scm
1349 Last, you can test the subset of the machines whose name matches a
1350 regular expression like this:
1353 # guix offload test machines.scm '\.gnu\.org$'
1356 @cindex offload status
1357 To display the current load of all build hosts, run this command on the
1361 # guix offload status
1365 @node SELinux Support
1366 @subsection SELinux Support
1368 @cindex SELinux, daemon policy
1369 @cindex mandatory access control, SELinux
1370 @cindex security, guix-daemon
1371 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1372 can be installed on a system where SELinux is enabled, in order to label
1373 Guix files and to specify the expected behavior of the daemon. Since
1374 Guix System does not provide an SELinux base policy, the daemon policy cannot
1375 be used on Guix System.
1377 @subsubsection Installing the SELinux policy
1378 @cindex SELinux, policy installation
1379 To install the policy run this command as root:
1382 semodule -i etc/guix-daemon.cil
1385 Then relabel the file system with @code{restorecon} or by a different
1386 mechanism provided by your system.
1388 Once the policy is installed, the file system has been relabeled, and
1389 the daemon has been restarted, it should be running in the
1390 @code{guix_daemon_t} context. You can confirm this with the following
1394 ps -Zax | grep guix-daemon
1397 Monitor the SELinux log files as you run a command like @code{guix build
1398 hello} to convince yourself that SELinux permits all necessary
1401 @subsubsection Limitations
1402 @cindex SELinux, limitations
1404 This policy is not perfect. Here is a list of limitations or quirks
1405 that should be considered when deploying the provided SELinux policy for
1410 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1411 operations involve contexts that have anything to do with
1412 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1413 but it would be preferrable to define socket rules for only this label.
1416 @code{guix gc} cannot access arbitrary links to profiles. By design,
1417 the file label of the destination of a symlink is independent of the
1418 file label of the link itself. Although all profiles under
1419 $localstatedir are labelled, the links to these profiles inherit the
1420 label of the directory they are in. For links in the user’s home
1421 directory this will be @code{user_home_t}. But for links from the root
1422 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1423 directory, etc, this won’t work. @code{guix gc} would be prevented from
1424 reading and following these links.
1427 The daemon’s feature to listen for TCP connections might no longer work.
1428 This might require extra rules, because SELinux treats network sockets
1429 differently from files.
1432 Currently all files with a name matching the regular expression
1433 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1434 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1435 that name in any profile would be permitted to run in the
1436 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1437 build a package that provides this executable and convince a user to
1438 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1439 At that point SELinux could not prevent it from accessing files that are
1440 allowed for processes in that domain.
1442 You will need to relabel the store directory after all upgrades to
1443 @file{guix-daemon}, such as after running @code{guix pull}. Assuming the
1444 store is in @file{/gnu}, you can do this with @code{restorecon -vR /gnu},
1445 or by other means provided by your operating system.
1447 We could generate a much more restrictive policy at installation time,
1448 so that only the @emph{exact} file name of the currently installed
1449 @code{guix-daemon} executable would be labelled with
1450 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1451 The downside is that root would have to install or upgrade the policy at
1452 installation time whenever the Guix package that provides the
1453 effectively running @code{guix-daemon} executable is upgraded.
1456 @node Invoking guix-daemon
1457 @section Invoking @command{guix-daemon}
1459 The @command{guix-daemon} program implements all the functionality to
1460 access the store. This includes launching build processes, running the
1461 garbage collector, querying the availability of a build result, etc. It
1462 is normally run as @code{root} like this:
1465 # guix-daemon --build-users-group=guixbuild
1469 For details on how to set it up, @pxref{Setting Up the Daemon}.
1472 @cindex container, build environment
1473 @cindex build environment
1474 @cindex reproducible builds
1475 By default, @command{guix-daemon} launches build processes under
1476 different UIDs, taken from the build group specified with
1477 @option{--build-users-group}. In addition, each build process is run in a
1478 chroot environment that only contains the subset of the store that the
1479 build process depends on, as specified by its derivation
1480 (@pxref{Programming Interface, derivation}), plus a set of specific
1481 system directories. By default, the latter contains @file{/dev} and
1482 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1483 @dfn{container}: in addition to having its own file system tree, it has
1484 a separate mount name space, its own PID name space, network name space,
1485 etc. This helps achieve reproducible builds (@pxref{Features}).
1487 When the daemon performs a build on behalf of the user, it creates a
1488 build directory under @file{/tmp} or under the directory specified by
1489 its @env{TMPDIR} environment variable. This directory is shared with
1490 the container for the duration of the build, though within the container,
1491 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1493 The build directory is automatically deleted upon completion, unless the
1494 build failed and the client specified @option{--keep-failed}
1495 (@pxref{Invoking guix build, @option{--keep-failed}}).
1497 The daemon listens for connections and spawns one sub-process for each session
1498 started by a client (one of the @command{guix} sub-commands). The
1499 @command{guix processes} command allows you to get an overview of the activity
1500 on your system by viewing each of the active sessions and clients.
1501 @xref{Invoking guix processes}, for more information.
1503 The following command-line options are supported:
1506 @item --build-users-group=@var{group}
1507 Take users from @var{group} to run build processes (@pxref{Setting Up
1508 the Daemon, build users}).
1510 @item --no-substitutes
1512 Do not use substitutes for build products. That is, always build things
1513 locally instead of allowing downloads of pre-built binaries
1514 (@pxref{Substitutes}).
1516 When the daemon runs with @option{--no-substitutes}, clients can still
1517 explicitly enable substitution @i{via} the @code{set-build-options}
1518 remote procedure call (@pxref{The Store}).
1520 @anchor{daemon-substitute-urls}
1521 @item --substitute-urls=@var{urls}
1522 Consider @var{urls} the default whitespace-separated list of substitute
1523 source URLs. When this option is omitted,
1524 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1526 This means that substitutes may be downloaded from @var{urls}, as long
1527 as they are signed by a trusted signature (@pxref{Substitutes}).
1529 @xref{Getting Substitutes from Other Servers}, for more information on
1530 how to configure the daemon to get substitutes from other servers.
1534 Do not use offload builds to other machines (@pxref{Daemon Offload
1535 Setup}). That is, always build things locally instead of offloading
1536 builds to remote machines.
1538 @item --cache-failures
1539 Cache build failures. By default, only successful builds are cached.
1541 When this option is used, @command{guix gc --list-failures} can be used
1542 to query the set of store items marked as failed; @command{guix gc
1543 --clear-failures} removes store items from the set of cached failures.
1544 @xref{Invoking guix gc}.
1546 @item --cores=@var{n}
1548 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1551 The default value is @code{0}, but it may be overridden by clients, such
1552 as the @option{--cores} option of @command{guix build} (@pxref{Invoking
1555 The effect is to define the @env{NIX_BUILD_CORES} environment variable
1556 in the build process, which can then use it to exploit internal
1557 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1559 @item --max-jobs=@var{n}
1561 Allow at most @var{n} build jobs in parallel. The default value is
1562 @code{1}. Setting it to @code{0} means that no builds will be performed
1563 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1564 Setup}), or simply fail.
1566 @item --max-silent-time=@var{seconds}
1567 When the build or substitution process remains silent for more than
1568 @var{seconds}, terminate it and report a build failure.
1570 The default value is @code{0}, which disables the timeout.
1572 The value specified here can be overridden by clients (@pxref{Common
1573 Build Options, @option{--max-silent-time}}).
1575 @item --timeout=@var{seconds}
1576 Likewise, when the build or substitution process lasts for more than
1577 @var{seconds}, terminate it and report a build failure.
1579 The default value is @code{0}, which disables the timeout.
1581 The value specified here can be overridden by clients (@pxref{Common
1582 Build Options, @option{--timeout}}).
1584 @item --rounds=@var{N}
1585 Build each derivation @var{n} times in a row, and raise an error if
1586 consecutive build results are not bit-for-bit identical. Note that this
1587 setting can be overridden by clients such as @command{guix build}
1588 (@pxref{Invoking guix build}).
1590 When used in conjunction with @option{--keep-failed}, the differing
1591 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1592 This makes it easy to look for differences between the two results.
1595 Produce debugging output.
1597 This is useful to debug daemon start-up issues, but then it may be
1598 overridden by clients, for example the @option{--verbosity} option of
1599 @command{guix build} (@pxref{Invoking guix build}).
1601 @item --chroot-directory=@var{dir}
1602 Add @var{dir} to the build chroot.
1604 Doing this may change the result of build processes---for instance if
1605 they use optional dependencies found in @var{dir} when it is available,
1606 and not otherwise. For that reason, it is not recommended to do so.
1607 Instead, make sure that each derivation declares all the inputs that it
1610 @item --disable-chroot
1611 Disable chroot builds.
1613 Using this option is not recommended since, again, it would allow build
1614 processes to gain access to undeclared dependencies. It is necessary,
1615 though, when @command{guix-daemon} is running under an unprivileged user
1618 @item --log-compression=@var{type}
1619 Compress build logs according to @var{type}, one of @code{gzip},
1620 @code{bzip2}, or @code{none}.
1622 Unless @option{--lose-logs} is used, all the build logs are kept in the
1623 @var{localstatedir}. To save space, the daemon automatically compresses
1624 them with Bzip2 by default.
1626 @item --discover[=yes|no]
1627 Whether to discover substitute servers on the local network using mDNS
1630 This feature is still experimental. However, here are a few
1635 It might be faster/less expensive than fetching from remote servers;
1637 There are no security risks, only genuine substitutes will be used
1638 (@pxref{Substitute Authentication});
1640 An attacker advertising @command{guix publish} on your LAN cannot serve
1641 you malicious binaries, but they can learn what software you’re
1644 Servers may serve substitute over HTTP, unencrypted, so anyone on the
1645 LAN can see what software you’re installing.
1648 It is also possible to enable or disable substitute server discovery at
1649 run-time by running:
1652 herd discover guix-daemon on
1653 herd discover guix-daemon off
1656 @item --disable-deduplication
1657 @cindex deduplication
1658 Disable automatic file ``deduplication'' in the store.
1660 By default, files added to the store are automatically ``deduplicated'':
1661 if a newly added file is identical to another one found in the store,
1662 the daemon makes the new file a hard link to the other file. This can
1663 noticeably reduce disk usage, at the expense of slightly increased
1664 input/output load at the end of a build process. This option disables
1667 @item --gc-keep-outputs[=yes|no]
1668 Tell whether the garbage collector (GC) must keep outputs of live
1672 @cindex garbage collector roots
1673 When set to @code{yes}, the GC will keep the outputs of any live
1674 derivation available in the store---the @file{.drv} files. The default
1675 is @code{no}, meaning that derivation outputs are kept only if they are
1676 reachable from a GC root. @xref{Invoking guix gc}, for more on GC
1679 @item --gc-keep-derivations[=yes|no]
1680 Tell whether the garbage collector (GC) must keep derivations
1681 corresponding to live outputs.
1683 When set to @code{yes}, as is the case by default, the GC keeps
1684 derivations---i.e., @file{.drv} files---as long as at least one of their
1685 outputs is live. This allows users to keep track of the origins of
1686 items in their store. Setting it to @code{no} saves a bit of disk
1689 In this way, setting @option{--gc-keep-derivations} to @code{yes} causes
1690 liveness to flow from outputs to derivations, and setting
1691 @option{--gc-keep-outputs} to @code{yes} causes liveness to flow from
1692 derivations to outputs. When both are set to @code{yes}, the effect is
1693 to keep all the build prerequisites (the sources, compiler, libraries,
1694 and other build-time tools) of live objects in the store, regardless of
1695 whether these prerequisites are reachable from a GC root. This is
1696 convenient for developers since it saves rebuilds or downloads.
1698 @item --impersonate-linux-2.6
1699 On Linux-based systems, impersonate Linux 2.6. This means that the
1700 kernel's @command{uname} system call will report 2.6 as the release number.
1702 This might be helpful to build programs that (usually wrongfully) depend
1703 on the kernel version number.
1706 Do not keep build logs. By default they are kept under
1707 @file{@var{localstatedir}/guix/log}.
1709 @item --system=@var{system}
1710 Assume @var{system} as the current system type. By default it is the
1711 architecture/kernel pair found at configure time, such as
1712 @code{x86_64-linux}.
1714 @item --listen=@var{endpoint}
1715 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1716 as the file name of a Unix-domain socket if it starts with
1717 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1718 host name or host name and port to listen to. Here are a few examples:
1721 @item --listen=/gnu/var/daemon
1722 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1723 creating it if needed.
1725 @item --listen=localhost
1726 @cindex daemon, remote access
1727 @cindex remote access to the daemon
1728 @cindex daemon, cluster setup
1729 @cindex clusters, daemon setup
1730 Listen for TCP connections on the network interface corresponding to
1731 @code{localhost}, on port 44146.
1733 @item --listen=128.0.0.42:1234
1734 Listen for TCP connections on the network interface corresponding to
1735 @code{128.0.0.42}, on port 1234.
1738 This option can be repeated multiple times, in which case
1739 @command{guix-daemon} accepts connections on all the specified
1740 endpoints. Users can tell client commands what endpoint to connect to
1741 by setting the @env{GUIX_DAEMON_SOCKET} environment variable
1742 (@pxref{The Store, @env{GUIX_DAEMON_SOCKET}}).
1745 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1746 @option{--listen=@var{host}} is suitable on local networks, such as
1747 clusters, where only trusted nodes may connect to the build daemon. In
1748 other cases where remote access to the daemon is needed, we recommend
1749 using Unix-domain sockets along with SSH.
1752 When @option{--listen} is omitted, @command{guix-daemon} listens for
1753 connections on the Unix-domain socket located at
1754 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1758 @node Application Setup
1759 @section Application Setup
1761 @cindex foreign distro
1762 When using Guix on top of GNU/Linux distribution other than Guix System---a
1763 so-called @dfn{foreign distro}---a few additional steps are needed to
1764 get everything in place. Here are some of them.
1768 @anchor{locales-and-locpath}
1769 @cindex locales, when not on Guix System
1771 @vindex GUIX_LOCPATH
1772 Packages installed @i{via} Guix will not use the locale data of the
1773 host system. Instead, you must first install one of the locale packages
1774 available with Guix and then define the @env{GUIX_LOCPATH} environment
1778 $ guix install glibc-locales
1779 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1782 Note that the @code{glibc-locales} package contains data for all the
1783 locales supported by the GNU@tie{}libc and weighs in at around
1784 917@tie{}MiB@. Alternatively, the @code{glibc-utf8-locales} is smaller but
1785 limited to a few UTF-8 locales.
1787 The @env{GUIX_LOCPATH} variable plays a role similar to @env{LOCPATH}
1788 (@pxref{Locale Names, @env{LOCPATH},, libc, The GNU C Library Reference
1789 Manual}). There are two important differences though:
1793 @env{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1794 provided by foreign distros. Thus, using @env{GUIX_LOCPATH} allows you
1795 to make sure the programs of the foreign distro will not end up loading
1796 incompatible locale data.
1799 libc suffixes each entry of @env{GUIX_LOCPATH} with @code{/X.Y}, where
1800 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1801 should your Guix profile contain a mixture of programs linked against
1802 different libc version, each libc version will only try to load locale
1803 data in the right format.
1806 This is important because the locale data format used by different libc
1807 versions may be incompatible.
1809 @subsection Name Service Switch
1811 @cindex name service switch, glibc
1812 @cindex NSS (name service switch), glibc
1813 @cindex nscd (name service caching daemon)
1814 @cindex name service caching daemon (nscd)
1815 When using Guix on a foreign distro, we @emph{strongly recommend} that
1816 the system run the GNU C library's @dfn{name service cache daemon},
1817 @command{nscd}, which should be listening on the
1818 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1819 installed with Guix may fail to look up host names or user accounts, or
1820 may even crash. The next paragraphs explain why.
1822 @cindex @file{nsswitch.conf}
1823 The GNU C library implements a @dfn{name service switch} (NSS), which is
1824 an extensible mechanism for ``name lookups'' in general: host name
1825 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1826 The GNU C Library Reference Manual}).
1828 @cindex Network information service (NIS)
1829 @cindex NIS (Network information service)
1830 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1831 lookup implementations: for example, the @code{nss-mdns} plugin allow
1832 resolution of @code{.local} host names, the @code{nis} plugin allows
1833 user account lookup using the Network information service (NIS), and so
1834 on. These extra ``lookup services'' are configured system-wide in
1835 @file{/etc/nsswitch.conf}, and all the programs running on the system
1836 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1839 When they perform a name lookup---for instance by calling the
1840 @code{getaddrinfo} function in C---applications first try to connect to
1841 the nscd; on success, nscd performs name lookups on their behalf. If
1842 the nscd is not running, then they perform the name lookup by
1843 themselves, by loading the name lookup services into their own address
1844 space and running it. These name lookup services---the
1845 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1846 the host system's C library, rather than from the C library the
1847 application is linked against (the C library coming from Guix).
1849 And this is where the problem is: if your application is linked against
1850 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1851 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1852 likely crash or have its name lookups fail unexpectedly.
1854 Running @command{nscd} on the system, among other advantages, eliminates
1855 this binary incompatibility problem because those @code{libnss_*.so}
1856 files are loaded in the @command{nscd} process, not in applications
1859 @subsection X11 Fonts
1862 The majority of graphical applications use Fontconfig to locate and
1863 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1864 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1865 by default. Thus, to allow graphical applications installed with Guix
1866 to display fonts, you have to install fonts with Guix as well.
1867 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1868 @code{font-gnu-freefont}.
1870 @cindex @code{fc-cache}
1872 Once you have installed or removed fonts, or when you notice an
1873 application that does not find fonts, you may need to install Fontconfig
1874 and to force an update of its font cache by running:
1877 guix install fontconfig
1881 To display text written in Chinese languages, Japanese, or Korean in
1882 graphical applications, consider installing
1883 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1884 has multiple outputs, one per language family (@pxref{Packages with
1885 Multiple Outputs}). For instance, the following command installs fonts
1886 for Chinese languages:
1889 guix install font-adobe-source-han-sans:cn
1892 @cindex @code{xterm}
1893 Older programs such as @command{xterm} do not use Fontconfig and instead
1894 rely on server-side font rendering. Such programs require to specify a
1895 full name of a font using XLFD (X Logical Font Description), like this:
1898 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1901 To be able to use such full names for the TrueType fonts installed in
1902 your Guix profile, you need to extend the font path of the X server:
1904 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1905 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1907 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1910 @cindex @code{xlsfonts}
1911 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1912 to make sure your TrueType fonts are listed there.
1915 @subsection X.509 Certificates
1917 @cindex @code{nss-certs}
1918 The @code{nss-certs} package provides X.509 certificates, which allow
1919 programs to authenticate Web servers accessed over HTTPS.
1921 When using Guix on a foreign distro, you can install this package and
1922 define the relevant environment variables so that packages know where to
1923 look for certificates. @xref{X.509 Certificates}, for detailed
1926 @subsection Emacs Packages
1928 @cindex @code{emacs}
1929 When you install Emacs packages with Guix, the Elisp files are placed
1930 under the @file{share/emacs/site-lisp/} directory of the profile in
1931 which they are installed. The Elisp libraries are made available to
1932 Emacs through the @env{EMACSLOADPATH} environment variable, which is
1933 set when installing Emacs itself.
1935 Additionally, autoload definitions are automatically evaluated at the
1936 initialization of Emacs, by the Guix-specific
1937 @code{guix-emacs-autoload-packages} procedure. If, for some reason, you
1938 want to avoid auto-loading the Emacs packages installed with Guix, you
1939 can do so by running Emacs with the @option{--no-site-file} option
1940 (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1943 @node Upgrading Guix
1944 @section Upgrading Guix
1946 @cindex Upgrading Guix, on a foreign distro
1948 To upgrade Guix, run:
1954 @xref{Invoking guix pull}, for more information.
1956 @cindex upgrading Guix for the root user, on a foreign distro
1957 @cindex upgrading the Guix daemon, on a foreign distro
1958 @cindex @command{guix pull} for the root user, on a foreign distro
1960 On a foreign distro, you can upgrade the build daemon by running:
1967 followed by (assuming your distro uses the systemd service management
1971 systemctl restart guix-daemon.service
1974 On Guix System, upgrading the daemon is achieved by reconfiguring the
1975 system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
1979 @c *********************************************************************
1980 @node System Installation
1981 @chapter System Installation
1983 @cindex installing Guix System
1984 @cindex Guix System, installation
1985 This section explains how to install Guix System
1986 on a machine. Guix, as a package manager, can
1987 also be installed on top of a running GNU/Linux system,
1988 @pxref{Installation}.
1992 @c This paragraph is for people reading this from tty2 of the
1993 @c installation image.
1994 You are reading this documentation with an Info reader. For details on
1995 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1996 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1997 Info}. Hit @kbd{l} afterwards to come back here.
1999 Alternatively, run @command{info info} in another tty to keep the manual
2005 * Limitations:: What you can expect.
2006 * Hardware Considerations:: Supported hardware.
2007 * USB Stick and DVD Installation:: Preparing the installation medium.
2008 * Preparing for Installation:: Networking, partitioning, etc.
2009 * Guided Graphical Installation:: Easy graphical installation.
2010 * Manual Installation:: Manual installation for wizards.
2011 * After System Installation:: When installation succeeded.
2012 * Installing Guix in a VM:: Guix System playground.
2013 * Building the Installation Image:: How this comes to be.
2017 @section Limitations
2019 We consider Guix System to be ready for a wide range of ``desktop'' and server
2020 use cases. The reliability guarantees it provides---transactional upgrades
2021 and rollbacks, reproducibility---make it a solid foundation.
2023 Nevertheless, before you proceed with the installation, be aware of the
2024 following noteworthy limitations applicable to version @value{VERSION}:
2028 More and more system services are provided (@pxref{Services}), but some
2032 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
2033 as well as a number of X11 window managers. However, KDE is currently
2037 More than a disclaimer, this is an invitation to report issues (and success
2038 stories!), and to join us in improving it. @xref{Contributing}, for more
2042 @node Hardware Considerations
2043 @section Hardware Considerations
2045 @cindex hardware support on Guix System
2046 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
2047 builds around the kernel Linux-libre, which means that only hardware for
2048 which free software drivers and firmware exist is supported. Nowadays,
2049 a wide range of off-the-shelf hardware is supported on
2050 GNU/Linux-libre---from keyboards to graphics cards to scanners and
2051 Ethernet controllers. Unfortunately, there are still areas where
2052 hardware vendors deny users control over their own computing, and such
2053 hardware is not supported on Guix System.
2055 @cindex WiFi, hardware support
2056 One of the main areas where free drivers or firmware are lacking is WiFi
2057 devices. WiFi devices known to work include those using Atheros chips
2058 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
2059 driver, and those using Broadcom/AirForce chips (BCM43xx with
2060 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
2061 Linux-libre driver. Free firmware exists for both and is available
2062 out-of-the-box on Guix System, as part of @code{%base-firmware}
2063 (@pxref{operating-system Reference, @code{firmware}}).
2065 @cindex RYF, Respects Your Freedom
2066 The @uref{https://www.fsf.org/, Free Software Foundation} runs
2067 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
2068 certification program for hardware products that respect your freedom
2069 and your privacy and ensure that you have control over your device. We
2070 encourage you to check the list of RYF-certified devices.
2072 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
2073 web site. It contains a catalog of hardware devices with information
2074 about their support in GNU/Linux.
2077 @node USB Stick and DVD Installation
2078 @section USB Stick and DVD Installation
2080 An ISO-9660 installation image that can be written to a USB stick or
2081 burnt to a DVD can be downloaded from
2082 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz},
2083 where you can replace @code{x86_64-linux} with one of:
2087 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
2090 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
2093 @c start duplication of authentication part from ``Binary Installation''
2094 Make sure to download the associated @file{.sig} file and to verify the
2095 authenticity of the image against it, along these lines:
2098 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
2099 $ gpg --verify guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
2102 If that command fails because you do not have the required public key,
2103 then run this command to import it:
2106 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
2107 -qO - | gpg --import -
2111 and rerun the @code{gpg --verify} command.
2113 Take note that a warning like ``This key is not certified with a trusted
2114 signature!'' is normal.
2118 This image contains the tools necessary for an installation.
2119 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
2121 @unnumberedsubsec Copying to a USB Stick
2123 To copy the image to a USB stick, follow these steps:
2127 Decompress the image using the @command{xz} command:
2130 xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
2134 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
2135 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
2136 copy the image with:
2139 dd if=guix-system-install-@value{VERSION}.x86_64-linux.iso of=/dev/sdX status=progress
2143 Access to @file{/dev/sdX} usually requires root privileges.
2146 @unnumberedsubsec Burning on a DVD
2148 To copy the image to a DVD, follow these steps:
2152 Decompress the image using the @command{xz} command:
2155 xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
2159 Insert a blank DVD into your machine, and determine
2160 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
2161 copy the image with:
2164 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.x86_64-linux.iso
2167 Access to @file{/dev/srX} usually requires root privileges.
2170 @unnumberedsubsec Booting
2172 Once this is done, you should be able to reboot the system and boot from
2173 the USB stick or DVD@. The latter usually requires you to get in the
2174 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
2175 In order to boot from Libreboot, switch to the command mode by pressing
2176 the @kbd{c} key and type @command{search_grub usb}.
2178 @xref{Installing Guix in a VM}, if, instead, you would like to install
2179 Guix System in a virtual machine (VM).
2182 @node Preparing for Installation
2183 @section Preparing for Installation
2185 Once you have booted, you can use the guided graphical installer, which makes
2186 it easy to get started (@pxref{Guided Graphical Installation}). Alternatively,
2187 if you are already familiar with GNU/Linux and if you want more control than
2188 what the graphical installer provides, you can choose the ``manual''
2189 installation process (@pxref{Manual Installation}).
2191 The graphical installer is available on TTY1. You can obtain root shells on
2192 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
2193 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
2194 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
2195 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2196 which allows you to select text with the left mouse button and to paste it
2197 with the middle button.
2200 Installation requires access to the Internet so that any missing
2201 dependencies of your system configuration can be downloaded. See the
2202 ``Networking'' section below.
2205 @node Guided Graphical Installation
2206 @section Guided Graphical Installation
2208 The graphical installer is a text-based user interface. It will guide you,
2209 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2211 The first dialog boxes allow you to set up the system as you use it during the
2212 installation: you can choose the language, keyboard layout, and set up
2213 networking, which will be used during the installation. The image below shows
2214 the networking dialog.
2216 @image{images/installer-network,5in,, networking setup with the graphical installer}
2218 Later steps allow you to partition your hard disk, as shown in the image
2219 below, to choose whether or not to use encrypted file systems, to enter the
2220 host name and root password, and to create an additional account, among other
2223 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2225 Note that, at any time, the installer allows you to exit the current
2226 installation step and resume at a previous step, as show in the image below.
2228 @image{images/installer-resume,5in,, resuming the installation process}
2230 Once you're done, the installer produces an operating system configuration and
2231 displays it (@pxref{Using the Configuration System}). At that point you can
2232 hit ``OK'' and installation will proceed. On success, you can reboot into the
2233 new system and enjoy. @xref{After System Installation}, for what's next!
2236 @node Manual Installation
2237 @section Manual Installation
2239 This section describes how you would ``manually'' install GNU@tie{}Guix System
2240 on your machine. This option requires familiarity with GNU/Linux, with the
2241 shell, and with common administration tools. If you think this is not for
2242 you, consider using the guided graphical installer (@pxref{Guided Graphical
2245 The installation system provides root shells on TTYs 3 to 6; press
2246 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2247 many common tools needed to install the system. But it is also a full-blown
2248 Guix System, which means that you can install additional packages, should you
2249 need it, using @command{guix package} (@pxref{Invoking guix package}).
2252 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2253 * Proceeding with the Installation:: Installing.
2256 @node Keyboard Layout and Networking and Partitioning
2257 @subsection Keyboard Layout, Networking, and Partitioning
2259 Before you can install the system, you may want to adjust the keyboard layout,
2260 set up networking, and partition your target hard disk. This section will
2261 guide you through this.
2263 @subsubsection Keyboard Layout
2265 @cindex keyboard layout
2266 The installation image uses the US qwerty keyboard layout. If you want
2267 to change it, you can use the @command{loadkeys} command. For example,
2268 the following command selects the Dvorak keyboard layout:
2274 See the files under @file{/run/current-system/profile/share/keymaps} for
2275 a list of available keyboard layouts. Run @command{man loadkeys} for
2278 @subsubsection Networking
2280 Run the following command to see what your network interfaces are called:
2287 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2293 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2294 Wired interfaces have a name starting with @samp{e}; for example, the
2295 interface corresponding to the first on-board Ethernet controller is
2296 called @samp{eno1}. Wireless interfaces have a name starting with
2297 @samp{w}, like @samp{w1p2s0}.
2300 @item Wired connection
2301 To configure a wired network run the following command, substituting
2302 @var{interface} with the name of the wired interface you want to use.
2305 ifconfig @var{interface} up
2309 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2312 ip link set @var{interface} up
2315 @item Wireless connection
2318 To configure wireless networking, you can create a configuration file
2319 for the @command{wpa_supplicant} configuration tool (its location is not
2320 important) using one of the available text editors such as
2324 nano wpa_supplicant.conf
2327 As an example, the following stanza can go to this file and will work
2328 for many wireless networks, provided you give the actual SSID and
2329 passphrase for the network you are connecting to:
2333 ssid="@var{my-ssid}"
2335 psk="the network's secret passphrase"
2339 Start the wireless service and run it in the background with the
2340 following command (substitute @var{interface} with the name of the
2341 network interface you want to use):
2344 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2347 Run @command{man wpa_supplicant} for more information.
2351 At this point, you need to acquire an IP address. On a network where IP
2352 addresses are automatically assigned @i{via} DHCP, you can run:
2355 dhclient -v @var{interface}
2358 Try to ping a server to see if networking is up and running:
2364 Setting up network access is almost always a requirement because the
2365 image does not contain all the software and tools that may be needed.
2367 @cindex proxy, during system installation
2368 If you need HTTP and HTTPS access to go through a proxy, run the
2372 herd set-http-proxy guix-daemon @var{URL}
2376 where @var{URL} is the proxy URL, for example
2377 @code{http://example.org:8118}.
2379 @cindex installing over SSH
2380 If you want to, you can continue the installation remotely by starting
2384 herd start ssh-daemon
2387 Make sure to either set a password with @command{passwd}, or configure
2388 OpenSSH public key authentication before logging in.
2390 @subsubsection Disk Partitioning
2392 Unless this has already been done, the next step is to partition, and
2393 then format the target partition(s).
2395 The installation image includes several partitioning tools, including
2396 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2397 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2398 the partition layout you want:
2404 If your disk uses the GUID Partition Table (GPT) format and you plan to
2405 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2406 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2409 @cindex EFI, installation
2410 @cindex UEFI, installation
2411 @cindex ESP, EFI system partition
2412 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2413 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2414 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2417 parted /dev/sda set 1 esp on
2421 @vindex grub-bootloader
2422 @vindex grub-efi-bootloader
2423 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2424 @file{/sys/firmware/efi} exists in the installation image, then you should
2425 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2426 Otherwise you should use the BIOS-based GRUB, known as
2427 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2431 Once you are done partitioning the target hard disk drive, you have to
2432 create a file system on the relevant partition(s)@footnote{Currently
2433 Guix System only supports ext4, btrfs, JFS, and F2FS file systems. In
2434 particular, code that reads file system UUIDs and labels only works for these
2435 file system types.}. For the ESP, if you have one and assuming it is
2436 @file{/dev/sda1}, run:
2439 mkfs.fat -F32 /dev/sda1
2442 For the root file system, ext4 is the most widely used format. Other
2443 file systems, such as Btrfs, support compression, which is reported to
2444 nicely complement file deduplication that the daemon performs
2445 independently of the file system (@pxref{Invoking guix-daemon,
2448 Preferably, assign file systems a label so that you can easily and
2449 reliably refer to them in @code{file-system} declarations (@pxref{File
2450 Systems}). This is typically done using the @code{-L} option of
2451 @command{mkfs.ext4} and related commands. So, assuming the target root
2452 partition lives at @file{/dev/sda2}, a file system with the label
2453 @code{my-root} can be created with:
2456 mkfs.ext4 -L my-root /dev/sda2
2459 @cindex encrypted disk
2460 If you are instead planning to encrypt the root partition, you can use
2461 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2462 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2463 @code{man cryptsetup}} for more information). Assuming you want to
2464 store the root partition on @file{/dev/sda2}, the command sequence would
2465 be along these lines:
2468 cryptsetup luksFormat /dev/sda2
2469 cryptsetup open --type luks /dev/sda2 my-partition
2470 mkfs.ext4 -L my-root /dev/mapper/my-partition
2473 Once that is done, mount the target file system under @file{/mnt}
2474 with a command like (again, assuming @code{my-root} is the label of the
2478 mount LABEL=my-root /mnt
2481 Also mount any other file systems you would like to use on the target
2482 system relative to this path. If you have opted for @file{/boot/efi} as an
2483 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2484 found by @code{guix system init} afterwards.
2486 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2487 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2488 sure to initialize them with @command{mkswap}. Assuming you have one
2489 swap partition on @file{/dev/sda3}, you would run:
2496 Alternatively, you may use a swap file. For example, assuming that in
2497 the new system you want to use the file @file{/swapfile} as a swap file,
2498 you would run@footnote{This example will work for many types of file
2499 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2500 btrfs), the required steps may be different. For details, see the
2501 manual pages for @command{mkswap} and @command{swapon}.}:
2504 # This is 10 GiB of swap space. Adjust "count" to change the size.
2505 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2506 # For security, make the file readable and writable only by root.
2507 chmod 600 /mnt/swapfile
2508 mkswap /mnt/swapfile
2509 swapon /mnt/swapfile
2512 Note that if you have encrypted the root partition and created a swap
2513 file in its file system as described above, then the encryption also
2514 protects the swap file, just like any other file in that file system.
2516 @node Proceeding with the Installation
2517 @subsection Proceeding with the Installation
2519 With the target partitions ready and the target root mounted on
2520 @file{/mnt}, we're ready to go. First, run:
2523 herd start cow-store /mnt
2526 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2527 during the installation phase are written to the target disk on @file{/mnt}
2528 rather than kept in memory. This is necessary because the first phase of
2529 the @command{guix system init} command (see below) entails downloads or
2530 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2532 Next, you have to edit a file and
2533 provide the declaration of the operating system to be installed. To
2534 that end, the installation system comes with three text editors. We
2535 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2536 supports syntax highlighting and parentheses matching; other editors
2537 include GNU Zile (an Emacs clone), and
2538 nvi (a clone of the original BSD @command{vi} editor).
2539 We strongly recommend storing that file on the target root file system, say,
2540 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2541 configuration file once you have rebooted into the newly-installed system.
2543 @xref{Using the Configuration System}, for an overview of the
2544 configuration file. The example configurations discussed in that
2545 section are available under @file{/etc/configuration} in the
2546 installation image. Thus, to get started with a system configuration
2547 providing a graphical display server (a ``desktop'' system), you can run
2548 something along these lines:
2552 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2553 # nano /mnt/etc/config.scm
2556 You should pay attention to what your configuration file contains, and
2561 Make sure the @code{bootloader-configuration} form refers to the target
2562 you want to install GRUB on. It should mention @code{grub-bootloader} if
2563 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2564 for newer UEFI systems. For legacy systems, the @code{target} field
2565 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2566 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2567 currently mounted and a @code{file-system} entry is specified in your
2571 Be sure that your file system labels match the value of their respective
2572 @code{device} fields in your @code{file-system} configuration, assuming
2573 your @code{file-system} configuration uses the @code{file-system-label}
2574 procedure in its @code{device} field.
2577 If there are encrypted or RAID partitions, make sure to add a
2578 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2581 Once you are done preparing the configuration file, the new system must
2582 be initialized (remember that the target root file system is mounted
2586 guix system init /mnt/etc/config.scm /mnt
2590 This copies all the necessary files and installs GRUB on
2591 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2592 more information, @pxref{Invoking guix system}. This command may trigger
2593 downloads or builds of missing packages, which can take some time.
2595 Once that command has completed---and hopefully succeeded!---you can run
2596 @command{reboot} and boot into the new system. The @code{root} password
2597 in the new system is initially empty; other users' passwords need to be
2598 initialized by running the @command{passwd} command as @code{root},
2599 unless your configuration specifies otherwise
2600 (@pxref{user-account-password, user account passwords}).
2601 @xref{After System Installation}, for what's next!
2604 @node After System Installation
2605 @section After System Installation
2607 Success, you've now booted into Guix System! From then on, you can update the
2608 system whenever you want by running, say:
2612 sudo guix system reconfigure /etc/config.scm
2616 This builds a new system generation with the latest packages and services
2617 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2618 your system includes the latest security updates (@pxref{Security Updates}).
2620 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2622 @cindex sudo vs. @command{guix pull}
2623 Note that @command{sudo guix} runs your user's @command{guix} command and
2624 @emph{not} root's, because @command{sudo} leaves @env{PATH} unchanged. To
2625 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2627 The difference matters here, because @command{guix pull} updates
2628 the @command{guix} command and package definitions only for the user it is ran
2629 as. This means that if you choose to use @command{guix system reconfigure} in
2630 root's login shell, you'll need to @command{guix pull} separately.
2633 Now, @pxref{Getting Started}, and
2634 join us on @code{#guix} on the Freenode IRC network or on
2635 @email{guix-devel@@gnu.org} to share your experience!
2638 @node Installing Guix in a VM
2639 @section Installing Guix in a Virtual Machine
2641 @cindex virtual machine, Guix System installation
2642 @cindex virtual private server (VPS)
2643 @cindex VPS (virtual private server)
2644 If you'd like to install Guix System in a virtual machine (VM) or on a
2645 virtual private server (VPS) rather than on your beloved machine, this
2648 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2649 disk image, follow these steps:
2653 First, retrieve and decompress the Guix system installation image as
2654 described previously (@pxref{USB Stick and DVD Installation}).
2657 Create a disk image that will hold the installed system. To make a
2658 qcow2-formatted disk image, use the @command{qemu-img} command:
2661 qemu-img create -f qcow2 guix-system.img 50G
2664 The resulting file will be much smaller than 50 GB (typically less than
2665 1 MB), but it will grow as the virtualized storage device is filled up.
2668 Boot the USB installation image in an VM:
2671 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2672 -nic user,model=virtio-net-pci -boot menu=on,order=d \
2673 -drive file=guix-system.img \
2674 -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
2677 @code{-enable-kvm} is optional, but significantly improves performance,
2678 @pxref{Running Guix in a VM}.
2681 You're now root in the VM, proceed with the installation process.
2682 @xref{Preparing for Installation}, and follow the instructions.
2685 Once installation is complete, you can boot the system that's on your
2686 @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
2689 @node Building the Installation Image
2690 @section Building the Installation Image
2692 @cindex installation image
2693 The installation image described above was built using the @command{guix
2694 system} command, specifically:
2697 guix system image -t iso9660 gnu/system/install.scm
2700 Have a look at @file{gnu/system/install.scm} in the source tree,
2701 and see also @ref{Invoking guix system} for more information
2702 about the installation image.
2704 @section Building the Installation Image for ARM Boards
2706 Many ARM boards require a specific variant of the
2707 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2709 If you build a disk image and the bootloader is not available otherwise
2710 (on another boot drive etc), it's advisable to build an image that
2711 includes the bootloader, specifically:
2714 guix system image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2717 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2718 board, a list of possible boards will be printed.
2720 @c *********************************************************************
2721 @node Getting Started
2722 @chapter Getting Started
2724 Presumably, you've reached this section because either you have
2725 installed Guix on top of another distribution (@pxref{Installation}), or
2726 you've installed the standalone Guix System (@pxref{System
2727 Installation}). It's time for you to get started using Guix and this
2728 section aims to help you do that and give you a feel of what it's like.
2730 Guix is about installing software, so probably the first thing you'll
2731 want to do is to actually look for software. Let's say you're looking
2732 for a text editor, you can run:
2735 guix search text editor
2738 This command shows you a number of matching @dfn{packages}, each time
2739 showing the package's name, version, a description, and additional info.
2740 Once you've found out the one you want to use, let's say Emacs (ah ha!),
2741 you can go ahead and install it (run this command as a regular user,
2742 @emph{no need for root privileges}!):
2748 You've installed your first package, congrats! In the process, you've
2749 probably noticed that Guix downloaded pre-built binaries; or, if you
2750 explicitly chose to @emph{not} use pre-built binaries, then probably
2751 Guix is still building software (@pxref{Substitutes}, for more info).
2753 Unless you're using Guix System, the @command{guix install} command must
2754 have printed this hint:
2757 hint: Consider setting the necessary environment variables by running:
2759 GUIX_PROFILE="$HOME/.guix-profile"
2760 . "$GUIX_PROFILE/etc/profile"
2762 Alternately, see `guix package --search-paths -p "$HOME/.guix-profile"'.
2765 Indeed, you must now tell your shell where @command{emacs} and other
2766 programs installed with Guix are to be found. Pasting the two lines
2767 above will do just that: it will add
2768 @code{$HOME/.guix-profile/bin}---which is where the installed package
2769 is---to the @code{PATH} environment variable. You can paste these two
2770 lines in your shell so they take effect right away, but more importantly
2771 you should add them to @file{~/.bash_profile} (or equivalent file if you
2772 do not use Bash) so that environment variables are set next time you
2773 spawn a shell. You only need to do this once and other search paths
2774 environment variables will be taken care of similarly---e.g., if you
2775 eventually install @code{python} and Python libraries, @code{PYTHONPATH}
2778 You can go on installing packages at your will. To list installed
2782 guix package --list-installed
2785 To remove a package, you would unsurprisingly run @command{guix remove}.
2786 A distinguishing feature is the ability to @dfn{roll back} any operation
2787 you made---installation, removal, upgrade---by simply typing:
2790 guix package --roll-back
2793 This is because each operation is in fact a @dfn{transaction} that
2794 creates a new @dfn{generation}. These generations and the difference
2795 between them can be displayed by running:
2798 guix package --list-generations
2801 Now you know the basics of package management!
2803 @quotation Going further
2804 @xref{Package Management}, for more about package management. You may
2805 like @dfn{declarative} package management with @command{guix package
2806 --manifest}, managing separate @dfn{profiles} with @option{--profile},
2807 deleting old generations, collecting garbage, and other nifty features
2808 that will come in handy as you become more familiar with Guix. If you
2809 are a developer, @pxref{Development} for additional tools. And if
2810 you're curious, @pxref{Features}, to peek under the hood.
2813 Once you've installed a set of packages, you will want to periodically
2814 @emph{upgrade} them to the latest and greatest version. To do that, you
2815 will first pull the latest revision of Guix and its package collection:
2821 The end result is a new @command{guix} command, under
2822 @file{~/.config/guix/current/bin}. Unless you're on Guix System, the
2823 first time you run @command{guix pull}, be sure to follow the hint that
2824 the command prints and, similar to what we saw above, paste these two
2825 lines in your terminal and @file{.bash_profile}:
2828 GUIX_PROFILE="$HOME/.config/guix/current"
2829 . "$GUIX_PROFILE/etc/profile"
2833 You must also instruct your shell to point to this new @command{guix}:
2839 At this point, you're running a brand new Guix. You can thus go ahead
2840 and actually upgrade all the packages you previously installed:
2846 As you run this command, you will see that binaries are downloaded (or
2847 perhaps some packages are built), and eventually you end up with the
2848 upgraded packages. Should one of these upgraded packages not be to your
2849 liking, remember you can always roll back!
2851 You can display the exact revision of Guix you're currently using by
2858 The information it displays is @emph{all it takes to reproduce the exact
2859 same Guix}, be it at a different point in time or on a different
2862 @quotation Going further
2863 @xref{Invoking guix pull}, for more information. @xref{Channels}, on
2864 how to specify additional @dfn{channels} to pull packages from, how to
2865 replicate Guix, and more. You may also find @command{time-machine}
2866 handy (@pxref{Invoking guix time-machine}).
2869 If you installed Guix System, one of the first things you'll want to do
2870 is to upgrade your system. Once you've run @command{guix pull} to get
2871 the latest Guix, you can upgrade the system like this:
2874 sudo guix system reconfigure /etc/config.scm
2877 Upon completion, the system runs the latest versions of its software
2878 packages. When you eventually reboot, you'll notice a sub-menu in the
2879 bootloader that reads ``Old system generations'': it's what allows you
2880 to boot @emph{an older generation of your system}, should the latest
2881 generation be ``broken'' or otherwise unsatisfying. Just like for
2882 packages, you can always @emph{roll back} to a previous generation
2883 @emph{of the whole system}:
2886 sudo guix system roll-back
2889 There are many things you'll probably want to tweak on your system:
2890 adding new user accounts, adding new system services, fiddling with the
2891 configuration of those services, etc. The system configuration is
2892 @emph{entirely} described in the @file{/etc/config.scm} file.
2893 @xref{Using the Configuration System}, to learn how to change it.
2895 Now you know enough to get started!
2897 @quotation Resources
2898 The rest of this manual provides a reference for all things Guix. Here
2899 are some additional resources you may find useful:
2903 @xref{Top,,, guix-cookbook, The GNU Guix Cookbook}, for a list of
2904 ``how-to'' style of recipes for a variety of applications.
2907 The @uref{https://guix.gnu.org/guix-refcard.pdf, GNU Guix Reference
2908 Card} lists in two pages most of the commands and options you'll ever
2912 The web site contains @uref{https://guix.gnu.org/en/videos/,
2913 instructional videos} covering topics such as everyday use of Guix, how
2914 to get help, and how to become a contributor.
2917 @xref{Documentation}, to learn how to access documentation on your
2921 We hope you will enjoy Guix as much as the community enjoys building it!
2924 @c *********************************************************************
2925 @node Package Management
2926 @chapter Package Management
2929 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2930 remove software packages, without having to know about their build
2931 procedures or dependencies. Guix also goes beyond this obvious set of
2934 This chapter describes the main features of Guix, as well as the
2935 package management tools it provides. Along with the command-line
2936 interface described below (@pxref{Invoking guix package, @code{guix
2937 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2938 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2939 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2943 guix install emacs-guix
2947 * Features:: How Guix will make your life brighter.
2948 * Invoking guix package:: Package installation, removal, etc.
2949 * Substitutes:: Downloading pre-built binaries.
2950 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2951 * Invoking guix gc:: Running the garbage collector.
2952 * Invoking guix pull:: Fetching the latest Guix and distribution.
2953 * Invoking guix time-machine:: Running an older revision of Guix.
2954 * Inferiors:: Interacting with another revision of Guix.
2955 * Invoking guix describe:: Display information about your Guix revision.
2956 * Invoking guix archive:: Exporting and importing store files.
2962 Here we assume you've already made your first steps with Guix
2963 (@pxref{Getting Started}) and would like to get an overview about what's
2964 going on under the hood.
2966 When using Guix, each package ends up in the @dfn{package store}, in its
2967 own directory---something that resembles
2968 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2970 Instead of referring to these directories, users have their own
2971 @dfn{profile}, which points to the packages that they actually want to
2972 use. These profiles are stored within each user's home directory, at
2973 @code{$HOME/.guix-profile}.
2975 For example, @code{alice} installs GCC 4.7.2. As a result,
2976 @file{/home/alice/.guix-profile/bin/gcc} points to
2977 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2978 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2979 simply continues to point to
2980 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2981 coexist on the same system without any interference.
2983 The @command{guix package} command is the central tool to manage
2984 packages (@pxref{Invoking guix package}). It operates on the per-user
2985 profiles, and can be used @emph{with normal user privileges}.
2987 @cindex transactions
2988 The command provides the obvious install, remove, and upgrade
2989 operations. Each invocation is actually a @emph{transaction}: either
2990 the specified operation succeeds, or nothing happens. Thus, if the
2991 @command{guix package} process is terminated during the transaction,
2992 or if a power outage occurs during the transaction, then the user's
2993 profile remains in its previous state, and remains usable.
2995 In addition, any package transaction may be @emph{rolled back}. So, if,
2996 for example, an upgrade installs a new version of a package that turns
2997 out to have a serious bug, users may roll back to the previous instance
2998 of their profile, which was known to work well. Similarly, the global
2999 system configuration on Guix is subject to
3000 transactional upgrades and roll-back
3001 (@pxref{Using the Configuration System}).
3003 All packages in the package store may be @emph{garbage-collected}.
3004 Guix can determine which packages are still referenced by user
3005 profiles, and remove those that are provably no longer referenced
3006 (@pxref{Invoking guix gc}). Users may also explicitly remove old
3007 generations of their profile so that the packages they refer to can be
3010 @cindex reproducibility
3011 @cindex reproducible builds
3012 Guix takes a @dfn{purely functional} approach to package
3013 management, as described in the introduction (@pxref{Introduction}).
3014 Each @file{/gnu/store} package directory name contains a hash of all the
3015 inputs that were used to build that package---compiler, libraries, build
3016 scripts, etc. This direct correspondence allows users to make sure a
3017 given package installation matches the current state of their
3018 distribution. It also helps maximize @dfn{build reproducibility}:
3019 thanks to the isolated build environments that are used, a given build
3020 is likely to yield bit-identical files when performed on different
3021 machines (@pxref{Invoking guix-daemon, container}).
3024 This foundation allows Guix to support @dfn{transparent binary/source
3025 deployment}. When a pre-built binary for a @file{/gnu/store} item is
3026 available from an external source---a @dfn{substitute}, Guix just
3027 downloads it and unpacks it;
3028 otherwise, it builds the package from source, locally
3029 (@pxref{Substitutes}). Because build results are usually bit-for-bit
3030 reproducible, users do not have to trust servers that provide
3031 substitutes: they can force a local build and @emph{challenge} providers
3032 (@pxref{Invoking guix challenge}).
3034 Control over the build environment is a feature that is also useful for
3035 developers. The @command{guix environment} command allows developers of
3036 a package to quickly set up the right development environment for their
3037 package, without having to manually install the dependencies of the
3038 package into their profile (@pxref{Invoking guix environment}).
3040 @cindex replication, of software environments
3041 @cindex provenance tracking, of software artifacts
3042 All of Guix and its package definitions is version-controlled, and
3043 @command{guix pull} allows you to ``travel in time'' on the history of Guix
3044 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
3045 Guix instance on a different machine or at a later point in time, which in
3046 turn allows you to @emph{replicate complete software environments}, while
3047 retaining precise @dfn{provenance tracking} of the software.
3049 @node Invoking guix package
3050 @section Invoking @command{guix package}
3052 @cindex installing packages
3053 @cindex removing packages
3054 @cindex package installation
3055 @cindex package removal
3056 The @command{guix package} command is the tool that allows users to
3057 install, upgrade, and remove packages, as well as rolling back to
3058 previous configurations. It operates only on the user's own profile,
3059 and works with normal user privileges (@pxref{Features}). Its syntax
3063 guix package @var{options}
3066 @cindex transactions
3067 Primarily, @var{options} specifies the operations to be performed during
3068 the transaction. Upon completion, a new profile is created, but
3069 previous @dfn{generations} of the profile remain available, should the user
3072 For example, to remove @code{lua} and install @code{guile} and
3073 @code{guile-cairo} in a single transaction:
3076 guix package -r lua -i guile guile-cairo
3079 @cindex aliases, for @command{guix package}
3080 For your convenience, we also provide the following aliases:
3084 @command{guix search} is an alias for @command{guix package -s},
3086 @command{guix install} is an alias for @command{guix package -i},
3088 @command{guix remove} is an alias for @command{guix package -r},
3090 @command{guix upgrade} is an alias for @command{guix package -u},
3092 and @command{guix show} is an alias for @command{guix package --show=}.
3095 These aliases are less expressive than @command{guix package} and provide
3096 fewer options, so in some cases you'll probably want to use @command{guix
3099 @command{guix package} also supports a @dfn{declarative approach}
3100 whereby the user specifies the exact set of packages to be available and
3101 passes it @i{via} the @option{--manifest} option
3102 (@pxref{profile-manifest, @option{--manifest}}).
3105 For each user, a symlink to the user's default profile is automatically
3106 created in @file{$HOME/.guix-profile}. This symlink always points to the
3107 current generation of the user's default profile. Thus, users can add
3108 @file{$HOME/.guix-profile/bin} to their @env{PATH} environment
3109 variable, and so on.
3110 @cindex search paths
3111 If you are not using Guix System, consider adding the
3112 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
3113 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
3114 shells get all the right environment variable definitions:
3117 GUIX_PROFILE="$HOME/.guix-profile" ; \
3118 source "$GUIX_PROFILE/etc/profile"
3121 In a multi-user setup, user profiles are stored in a place registered as
3122 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
3123 to (@pxref{Invoking guix gc}). That directory is normally
3124 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
3125 @var{localstatedir} is the value passed to @code{configure} as
3126 @option{--localstatedir}, and @var{user} is the user name. The
3127 @file{per-user} directory is created when @command{guix-daemon} is
3128 started, and the @var{user} sub-directory is created by @command{guix
3131 The @var{options} can be among the following:
3135 @item --install=@var{package} @dots{}
3136 @itemx -i @var{package} @dots{}
3137 Install the specified @var{package}s.
3139 Each @var{package} may specify either a simple package name, such as
3140 @code{guile}, or a package name followed by an at-sign and version number,
3141 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
3142 case, the newest version prefixed by @code{1.8} is selected).
3144 If no version number is specified, the
3145 newest available version will be selected. In addition, @var{package}
3146 may contain a colon, followed by the name of one of the outputs of the
3147 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
3148 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
3149 name (and optionally version) are searched for among the GNU
3150 distribution modules (@pxref{Package Modules}).
3152 @cindex propagated inputs
3153 Sometimes packages have @dfn{propagated inputs}: these are dependencies
3154 that automatically get installed along with the required package
3155 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
3156 @code{package} objects}, for information about propagated inputs in
3157 package definitions).
3159 @anchor{package-cmd-propagated-inputs}
3160 An example is the GNU MPC library: its C header files refer to those of
3161 the GNU MPFR library, which in turn refer to those of the GMP library.
3162 Thus, when installing MPC, the MPFR and GMP libraries also get installed
3163 in the profile; removing MPC also removes MPFR and GMP---unless they had
3164 also been explicitly installed by the user.
3166 Besides, packages sometimes rely on the definition of environment
3167 variables for their search paths (see explanation of
3168 @option{--search-paths} below). Any missing or possibly incorrect
3169 environment variable definitions are reported here.
3171 @item --install-from-expression=@var{exp}
3173 Install the package @var{exp} evaluates to.
3175 @var{exp} must be a Scheme expression that evaluates to a
3176 @code{<package>} object. This option is notably useful to disambiguate
3177 between same-named variants of a package, with expressions such as
3178 @code{(@@ (gnu packages base) guile-final)}.
3180 Note that this option installs the first output of the specified
3181 package, which may be insufficient when needing a specific output of a
3182 multiple-output package.
3184 @item --install-from-file=@var{file}
3185 @itemx -f @var{file}
3186 Install the package that the code within @var{file} evaluates to.
3188 As an example, @var{file} might contain a definition like this
3189 (@pxref{Defining Packages}):
3192 @include package-hello.scm
3195 Developers may find it useful to include such a @file{guix.scm} file
3196 in the root of their project source tree that can be used to test
3197 development snapshots and create reproducible development environments
3198 (@pxref{Invoking guix environment}).
3200 The @var{file} may also contain a JSON representation of one or more
3201 package definitions. Running @code{guix package -f} on
3202 @file{hello.json} with the following contents would result in installing
3203 the package @code{greeter} after building @code{myhello}:
3206 @verbatiminclude package-hello.json
3209 @item --remove=@var{package} @dots{}
3210 @itemx -r @var{package} @dots{}
3211 Remove the specified @var{package}s.
3213 As for @option{--install}, each @var{package} may specify a version number
3214 and/or output name in addition to the package name. For instance,
3215 @samp{-r glibc:debug} would remove the @code{debug} output of
3218 @item --upgrade[=@var{regexp} @dots{}]
3219 @itemx -u [@var{regexp} @dots{}]
3220 @cindex upgrading packages
3221 Upgrade all the installed packages. If one or more @var{regexp}s are
3222 specified, upgrade only installed packages whose name matches a
3223 @var{regexp}. Also see the @option{--do-not-upgrade} option below.
3225 Note that this upgrades package to the latest version of packages found
3226 in the distribution currently installed. To update your distribution,
3227 you should regularly run @command{guix pull} (@pxref{Invoking guix
3230 @cindex package transformations, upgrades
3231 When upgrading, package transformations that were originally applied
3232 when creating the profile are automatically re-applied (@pxref{Package
3233 Transformation Options}). For example, assume you first installed Emacs
3234 from the tip of its development branch with:
3237 guix install emacs-next --with-branch=emacs-next=master
3240 Next time you run @command{guix upgrade}, Guix will again pull the tip
3241 of the Emacs development branch and build @code{emacs-next} from that
3244 Note that transformation options such as @option{--with-branch} and
3245 @option{--with-source} depend on external state; it is up to you to
3246 ensure that they work as expected. You can also discard a
3247 transformations that apply to a package by running:
3250 guix install @var{package}
3253 @item --do-not-upgrade[=@var{regexp} @dots{}]
3254 When used together with the @option{--upgrade} option, do @emph{not}
3255 upgrade any packages whose name matches a @var{regexp}. For example, to
3256 upgrade all packages in the current profile except those containing the
3257 substring ``emacs'':
3260 $ guix package --upgrade . --do-not-upgrade emacs
3263 @item @anchor{profile-manifest}--manifest=@var{file}
3264 @itemx -m @var{file}
3265 @cindex profile declaration
3266 @cindex profile manifest
3267 Create a new generation of the profile from the manifest object
3268 returned by the Scheme code in @var{file}. This option can be repeated
3269 several times, in which case the manifests are concatenated.
3271 This allows you to @emph{declare} the profile's contents rather than
3272 constructing it through a sequence of @option{--install} and similar
3273 commands. The advantage is that @var{file} can be put under version
3274 control, copied to different machines to reproduce the same profile, and
3277 @c FIXME: Add reference to (guix profile) documentation when available.
3278 @var{file} must return a @dfn{manifest} object, which is roughly a list
3281 @findex packages->manifest
3283 (use-package-modules guile emacs)
3288 ;; Use a specific package output.
3289 (list guile-2.0 "debug")))
3292 @findex specifications->manifest
3293 In this example we have to know which modules define the @code{emacs}
3294 and @code{guile-2.0} variables to provide the right
3295 @code{use-package-modules} line, which can be cumbersome. We can
3296 instead provide regular package specifications and let
3297 @code{specifications->manifest} look up the corresponding package
3301 (specifications->manifest
3302 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
3305 @xref{export-manifest, @option{--export-manifest}}, to learn how to
3306 obtain a manifest file from an existing profile.
3309 @cindex rolling back
3310 @cindex undoing transactions
3311 @cindex transactions, undoing
3312 Roll back to the previous @dfn{generation} of the profile---i.e., undo
3313 the last transaction.
3315 When combined with options such as @option{--install}, roll back occurs
3316 before any other actions.
3318 When rolling back from the first generation that actually contains
3319 installed packages, the profile is made to point to the @dfn{zeroth
3320 generation}, which contains no files apart from its own metadata.
3322 After having rolled back, installing, removing, or upgrading packages
3323 overwrites previous future generations. Thus, the history of the
3324 generations in a profile is always linear.
3326 @item --switch-generation=@var{pattern}
3327 @itemx -S @var{pattern}
3329 Switch to a particular generation defined by @var{pattern}.
3331 @var{pattern} may be either a generation number or a number prefixed
3332 with ``+'' or ``-''. The latter means: move forward/backward by a
3333 specified number of generations. For example, if you want to return to
3334 the latest generation after @option{--roll-back}, use
3335 @option{--switch-generation=+1}.
3337 The difference between @option{--roll-back} and
3338 @option{--switch-generation=-1} is that @option{--switch-generation} will
3339 not make a zeroth generation, so if a specified generation does not
3340 exist, the current generation will not be changed.
3342 @item --search-paths[=@var{kind}]
3343 @cindex search paths
3344 Report environment variable definitions, in Bash syntax, that may be
3345 needed in order to use the set of installed packages. These environment
3346 variables are used to specify @dfn{search paths} for files used by some
3347 of the installed packages.
3349 For example, GCC needs the @env{CPATH} and @env{LIBRARY_PATH}
3350 environment variables to be defined so it can look for headers and
3351 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
3352 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
3353 library are installed in the profile, then @option{--search-paths} will
3354 suggest setting these variables to @file{@var{profile}/include} and
3355 @file{@var{profile}/lib}, respectively.
3357 The typical use case is to define these environment variables in the
3361 $ eval `guix package --search-paths`
3364 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
3365 meaning that the returned environment variable definitions will either
3366 be exact settings, or prefixes or suffixes of the current value of these
3367 variables. When omitted, @var{kind} defaults to @code{exact}.
3369 This option can also be used to compute the @emph{combined} search paths
3370 of several profiles. Consider this example:
3373 $ guix package -p foo -i guile
3374 $ guix package -p bar -i guile-json
3375 $ guix package -p foo -p bar --search-paths
3378 The last command above reports about the @env{GUILE_LOAD_PATH}
3379 variable, even though, taken individually, neither @file{foo} nor
3380 @file{bar} would lead to that recommendation.
3383 @item --profile=@var{profile}
3384 @itemx -p @var{profile}
3385 Use @var{profile} instead of the user's default profile.
3387 @var{profile} must be the name of a file that will be created upon
3388 completion. Concretely, @var{profile} will be a mere symbolic link
3389 (``symlink'') pointing to the actual profile where packages are
3393 $ guix install hello -p ~/code/my-profile
3395 $ ~/code/my-profile/bin/hello
3399 All it takes to get rid of the profile is to remove this symlink and its
3400 siblings that point to specific generations:
3403 $ rm ~/code/my-profile ~/code/my-profile-*-link
3406 @item --list-profiles
3407 List all the user's profiles:
3410 $ guix package --list-profiles
3411 /home/charlie/.guix-profile
3412 /home/charlie/code/my-profile
3413 /home/charlie/code/devel-profile
3414 /home/charlie/tmp/test
3417 When running as root, list all the profiles of all the users.
3419 @cindex collisions, in a profile
3420 @cindex colliding packages in profiles
3421 @cindex profile collisions
3422 @item --allow-collisions
3423 Allow colliding packages in the new profile. Use at your own risk!
3425 By default, @command{guix package} reports as an error @dfn{collisions}
3426 in the profile. Collisions happen when two or more different versions
3427 or variants of a given package end up in the profile.
3430 Use the bootstrap Guile to build the profile. This option is only
3431 useful to distribution developers.
3435 In addition to these actions, @command{guix package} supports the
3436 following options to query the current state of a profile, or the
3437 availability of packages:
3441 @item --search=@var{regexp}
3442 @itemx -s @var{regexp}
3443 @anchor{guix-search}
3444 @cindex searching for packages
3445 List the available packages whose name, synopsis, or description matches
3446 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
3447 Print all the metadata of matching packages in
3448 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
3449 GNU recutils manual}).
3451 This allows specific fields to be extracted using the @command{recsel}
3452 command, for instance:
3455 $ guix package -s malloc | recsel -p name,version,relevance
3469 Similarly, to show the name of all the packages available under the
3470 terms of the GNU@tie{}LGPL version 3:
3473 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
3480 It is also possible to refine search results using several @code{-s} flags to
3481 @command{guix package}, or several arguments to @command{guix search}. For
3482 example, the following command returns a list of board games (this time using
3483 the @command{guix search} alias):
3486 $ guix search '\<board\>' game | recsel -p name
3491 If we were to omit @code{-s game}, we would also get software packages
3492 that deal with printed circuit boards; removing the angle brackets
3493 around @code{board} would further add packages that have to do with
3496 And now for a more elaborate example. The following command searches
3497 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
3498 libraries, and prints the name and synopsis of the matching packages:
3501 $ guix search crypto library | \
3502 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3506 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3507 information on @dfn{selection expressions} for @code{recsel -e}.
3509 @item --show=@var{package}
3510 Show details about @var{package}, taken from the list of available packages, in
3511 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3515 $ guix package --show=python | recsel -p name,version
3523 You may also specify the full name of a package to only get details about a
3524 specific version of it (this time using the @command{guix show} alias):
3526 $ guix show python@@3.4 | recsel -p name,version
3533 @item --list-installed[=@var{regexp}]
3534 @itemx -I [@var{regexp}]
3535 List the currently installed packages in the specified profile, with the
3536 most recently installed packages shown last. When @var{regexp} is
3537 specified, list only installed packages whose name matches @var{regexp}.
3539 For each installed package, print the following items, separated by
3540 tabs: the package name, its version string, the part of the package that
3541 is installed (for instance, @code{out} for the default output,
3542 @code{include} for its headers, etc.), and the path of this package in
3545 @item --list-available[=@var{regexp}]
3546 @itemx -A [@var{regexp}]
3547 List packages currently available in the distribution for this system
3548 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3549 available packages whose name matches @var{regexp}.
3551 For each package, print the following items separated by tabs: its name,
3552 its version string, the parts of the package (@pxref{Packages with
3553 Multiple Outputs}), and the source location of its definition.
3555 @item --list-generations[=@var{pattern}]
3556 @itemx -l [@var{pattern}]
3558 Return a list of generations along with their creation dates; for each
3559 generation, show the installed packages, with the most recently
3560 installed packages shown last. Note that the zeroth generation is never
3563 For each installed package, print the following items, separated by
3564 tabs: the name of a package, its version string, the part of the package
3565 that is installed (@pxref{Packages with Multiple Outputs}), and the
3566 location of this package in the store.
3568 When @var{pattern} is used, the command returns only matching
3569 generations. Valid patterns include:
3572 @item @emph{Integers and comma-separated integers}. Both patterns denote
3573 generation numbers. For instance, @option{--list-generations=1} returns
3576 And @option{--list-generations=1,8,2} outputs three generations in the
3577 specified order. Neither spaces nor trailing commas are allowed.
3579 @item @emph{Ranges}. @option{--list-generations=2..9} prints the
3580 specified generations and everything in between. Note that the start of
3581 a range must be smaller than its end.
3583 It is also possible to omit the endpoint. For example,
3584 @option{--list-generations=2..}, returns all generations starting from the
3587 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3588 or months by passing an integer along with the first letter of the
3589 duration. For example, @option{--list-generations=20d} lists generations
3590 that are up to 20 days old.
3593 @item --delete-generations[=@var{pattern}]
3594 @itemx -d [@var{pattern}]
3595 When @var{pattern} is omitted, delete all generations except the current
3598 This command accepts the same patterns as @option{--list-generations}.
3599 When @var{pattern} is specified, delete the matching generations. When
3600 @var{pattern} specifies a duration, generations @emph{older} than the
3601 specified duration match. For instance, @option{--delete-generations=1m}
3602 deletes generations that are more than one month old.
3604 If the current generation matches, it is @emph{not} deleted. Also, the
3605 zeroth generation is never deleted.
3607 Note that deleting generations prevents rolling back to them.
3608 Consequently, this command must be used with care.
3610 @cindex manifest, exporting
3611 @anchor{export-manifest}
3612 @item --export-manifest
3613 Write to standard output a manifest suitable for @option{--manifest}
3614 corresponding to the chosen profile(s).
3616 This option is meant to help you migrate from the ``imperative''
3617 operating mode---running @command{guix install}, @command{guix upgrade},
3618 etc.---to the declarative mode that @option{--manifest} offers.
3620 Be aware that the resulting manifest @emph{approximates} what your
3621 profile actually contains; for instance, depending on how your profile
3622 was created, it can refer to packages or package versions that are not
3623 exactly what you specified.
3625 Keep in mind that a manifest is purely symbolic: it only contains
3626 package names and possibly versions, and their meaning varies over time.
3627 If you wish to ``pin'' channels to the revisions that were used to build
3628 the profile(s), see @option{--export-channels} below.
3630 @cindex pinning, channel revisions of a profile
3631 @item --export-channels
3632 Write to standard output the list of channels used by the chosen
3633 profile(s), in a format suitable for @command{guix pull --channels} or
3634 @command{guix time-machine --channels} (@pxref{Channels}).
3636 Together with @option{--export-manifest}, this option provides
3637 information allowing you to replicate the current profile
3638 (@pxref{Replicating Guix}).
3640 However, note that the output of this command @emph{approximates} what
3641 was actually used to build this profile. In particular, a single
3642 profile might have been built from several different revisions of the
3643 same channel. In that case, @option{--export-manifest} chooses the last
3644 one and writes the list of other revisions in a comment. If you really
3645 need to pick packages from different channel revisions, you can use
3646 inferiors in your manifest to do so (@pxref{Inferiors}).
3648 Together with @option{--export-manifest}, this is a good starting point
3649 if you are willing to migrate from the ``imperative'' model to the fully
3650 declarative model consisting of a manifest file along with a channels
3651 file pinning the exact channel revision(s) you want.
3654 Finally, since @command{guix package} may actually start build
3655 processes, it supports all the common build options (@pxref{Common Build
3656 Options}). It also supports package transformation options, such as
3657 @option{--with-source}, and preserves them across upgrades
3658 (@pxref{Package Transformation Options}).
3661 @section Substitutes
3664 @cindex pre-built binaries
3665 Guix supports transparent source/binary deployment, which means that it
3666 can either build things locally, or download pre-built items from a
3667 server, or both. We call these pre-built items @dfn{substitutes}---they
3668 are substitutes for local build results. In many cases, downloading a
3669 substitute is much faster than building things locally.
3671 Substitutes can be anything resulting from a derivation build
3672 (@pxref{Derivations}). Of course, in the common case, they are
3673 pre-built package binaries, but source tarballs, for instance, which
3674 also result from derivation builds, can be available as substitutes.
3677 * Official Substitute Server:: One particular source of substitutes.
3678 * Substitute Server Authorization:: How to enable or disable substitutes.
3679 * Getting Substitutes from Other Servers:: Substitute diversity.
3680 * Substitute Authentication:: How Guix verifies substitutes.
3681 * Proxy Settings:: How to get substitutes via proxy.
3682 * Substitution Failure:: What happens when substitution fails.
3683 * On Trusting Binaries:: How can you trust that binary blob?
3686 @node Official Substitute Server
3687 @subsection Official Substitute Server
3690 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3691 that builds packages from Guix continuously for some
3692 architectures, and makes them available as substitutes. This is the
3693 default source of substitutes; it can be overridden by passing the
3694 @option{--substitute-urls} option either to @command{guix-daemon}
3695 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3696 or to client tools such as @command{guix package}
3697 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3700 Substitute URLs can be either HTTP or HTTPS.
3701 HTTPS is recommended because communications are encrypted; conversely,
3702 using HTTP makes all communications visible to an eavesdropper, who
3703 could use the information gathered to determine, for instance, whether
3704 your system has unpatched security vulnerabilities.
3706 Substitutes from the official build farm are enabled by default when
3707 using Guix System (@pxref{GNU Distribution}). However,
3708 they are disabled by default when using Guix on a foreign distribution,
3709 unless you have explicitly enabled them via one of the recommended
3710 installation steps (@pxref{Installation}). The following paragraphs
3711 describe how to enable or disable substitutes for the official build
3712 farm; the same procedure can also be used to enable substitutes for any
3713 other substitute server.
3715 @node Substitute Server Authorization
3716 @subsection Substitute Server Authorization
3719 @cindex substitutes, authorization thereof
3720 @cindex access control list (ACL), for substitutes
3721 @cindex ACL (access control list), for substitutes
3722 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3724 must add its public key to the access control list (ACL) of archive
3725 imports, using the @command{guix archive} command (@pxref{Invoking guix
3726 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3727 be compromised and to serve genuine substitutes.
3730 If you are using Guix System, you can skip this section: Guix System
3731 authorizes substitutes from @code{@value{SUBSTITUTE-SERVER}} by default.
3734 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3735 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3736 the installation prefix of Guix. If you installed Guix from source,
3737 make sure you checked the GPG signature of
3738 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3739 Then, you can run something like this:
3742 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3745 Once this is in place, the output of a command like @code{guix build}
3746 should change from something like:
3749 $ guix build emacs --dry-run
3750 The following derivations would be built:
3751 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3752 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3753 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3754 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3762 $ guix build emacs --dry-run
3763 112.3 MB would be downloaded:
3764 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3765 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3766 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3767 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3772 The text changed from ``The following derivations would be built'' to
3773 ``112.3 MB would be downloaded''. This indicates that substitutes from
3774 @code{@value{SUBSTITUTE-SERVER}} are usable and will be downloaded, when
3775 possible, for future builds.
3777 @cindex substitutes, how to disable
3778 The substitute mechanism can be disabled globally by running
3779 @code{guix-daemon} with @option{--no-substitutes} (@pxref{Invoking
3780 guix-daemon}). It can also be disabled temporarily by passing the
3781 @option{--no-substitutes} option to @command{guix package},
3782 @command{guix build}, and other command-line tools.
3784 @node Getting Substitutes from Other Servers
3785 @subsection Getting Substitutes from Other Servers
3787 @cindex substitute servers, adding more
3788 Guix can look up and fetch substitutes from several servers. This is
3789 useful when you are using packages from additional channels for which
3790 the official server does not have substitutes but another server
3791 provides them. Another situation where this is useful is when you would
3792 prefer to download from your organization's substitute server, resorting
3793 to the official server only as a fallback or dismissing it altogether.
3795 You can give Guix a list of substitute server URLs and it will check
3796 them in the specified order. You also need to explicitly authorize the
3797 public keys of substitute servers to instruct Guix to accept the
3798 substitutes they sign.
3800 On Guix System, this is achieved by modifying the configuration of the
3801 @code{guix} service. Since the @code{guix} service is part of the
3802 default lists of services, @code{%base-services} and
3803 @code{%desktop-services}, you can use @code{modify-services} to change
3804 its configuration and add the URLs and substitute keys that you want
3805 (@pxref{Service Reference, @code{modify-services}}).
3807 As an example, suppose you want to fetch substitutes from
3808 @code{guix.example.org} and to authorize the signing key of that server,
3809 in addition to the default @code{@value{SUBSTITUTE-SERVER}}. The
3810 resulting operating system configuration will look something like:
3816 ;; Assume we're starting from '%desktop-services'. Replace it
3817 ;; with the list of services you're actually using.
3818 (modify-services %desktop-services
3819 (guix-service-type config =>
3823 (append (list "https://guix.example.org")
3824 %default-substitute-urls))
3826 (append (list (local-file "./key.pub"))
3827 %default-authorized-guix-keys)))))))
3830 This assumes that the file @file{key.pub} contains the signing key of
3831 @code{guix.example.org}. With this change in place in your operating
3832 system configuration file (say @file{/etc/config.scm}), you can
3833 reconfigure and restart the @code{guix-daemon} service or reboot so the
3834 changes take effect:
3837 $ sudo guix system reconfigure /etc/config.scm
3838 $ sudo herd restart guix-daemon
3841 If you're running Guix on a ``foreign distro'', you would instead take
3842 the following steps to get substitutes from additional servers:
3846 Edit the service configuration file for @code{guix-daemon}; when using
3847 systemd, this is normally
3848 @file{/etc/systemd/system/guix-daemon.service}. Add the
3849 @option{--substitute-urls} option on the @command{guix-daemon} command
3850 line and list the URLs of interest (@pxref{daemon-substitute-urls,
3851 @code{guix-daemon --substitute-urls}}):
3854 @dots{} --substitute-urls='https://guix.example.org https://@value{SUBSTITUTE-SERVER}'
3858 Restart the daemon. For systemd, it goes like this:
3861 systemctl daemon-reload
3862 systemctl restart guix-daemon.service
3866 Authorize the key of the new server (@pxref{Invoking guix archive}):
3869 guix archive --authorize < key.pub
3872 Again this assumes @file{key.pub} contains the public key that
3873 @code{guix.example.org} uses to sign substitutes.
3876 Now you're all set! Substitutes will be preferably taken from
3877 @code{https://guix.example.org}, using @code{@value{SUBSTITUTE-SERVER}}
3878 as a fallback. Of course you can list as many substitute servers as you
3879 like, with the caveat that substitute lookup can be slowed down if too
3880 many servers need to be contacted.
3882 Note that there are also situations where one may want to add the URL of
3883 a substitute server @emph{without} authorizing its key.
3884 @xref{Substitute Authentication}, to understand this fine point.
3886 @node Substitute Authentication
3887 @subsection Substitute Authentication
3889 @cindex digital signatures
3890 Guix detects and raises an error when attempting to use a substitute
3891 that has been tampered with. Likewise, it ignores substitutes that are
3892 not signed, or that are not signed by one of the keys listed in the ACL.
3894 There is one exception though: if an unauthorized server provides
3895 substitutes that are @emph{bit-for-bit identical} to those provided by
3896 an authorized server, then the unauthorized server becomes eligible for
3897 downloads. For example, assume we have chosen two substitute servers
3901 --substitute-urls="https://a.example.org https://b.example.org"
3905 @cindex reproducible builds
3906 If the ACL contains only the key for @samp{b.example.org}, and if
3907 @samp{a.example.org} happens to serve the @emph{exact same} substitutes,
3908 then Guix will download substitutes from @samp{a.example.org} because it
3909 comes first in the list and can be considered a mirror of
3910 @samp{b.example.org}. In practice, independent build machines usually
3911 produce the same binaries, thanks to bit-reproducible builds (see
3914 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3915 (in other words, the server is not authenticated), contrary to what
3916 HTTPS clients such as Web browsers usually do. This is because Guix
3917 authenticates substitute information itself, as explained above, which
3918 is what we care about (whereas X.509 certificates are about
3919 authenticating bindings between domain names and public keys).
3921 @node Proxy Settings
3922 @subsection Proxy Settings
3926 Substitutes are downloaded over HTTP or HTTPS@. The @env{http_proxy} and
3927 @env{https_proxy} environment variables can be set in the environment of
3928 @command{guix-daemon} and are honored for downloads of substitutes.
3929 Note that the value of those environment variables in the environment
3930 where @command{guix build}, @command{guix package}, and other client
3931 commands are run has @emph{absolutely no effect}.
3933 @node Substitution Failure
3934 @subsection Substitution Failure
3936 Even when a substitute for a derivation is available, sometimes the
3937 substitution attempt will fail. This can happen for a variety of
3938 reasons: the substitute server might be offline, the substitute may
3939 recently have been deleted, the connection might have been interrupted,
3942 When substitutes are enabled and a substitute for a derivation is
3943 available, but the substitution attempt fails, Guix will attempt to
3944 build the derivation locally depending on whether or not
3945 @option{--fallback} was given (@pxref{fallback-option,, common build
3946 option @option{--fallback}}). Specifically, if @option{--fallback} was
3947 omitted, then no local build will be performed, and the derivation is
3948 considered to have failed. However, if @option{--fallback} was given,
3949 then Guix will attempt to build the derivation locally, and the success
3950 or failure of the derivation depends on the success or failure of the
3951 local build. Note that when substitutes are disabled or no substitute
3952 is available for the derivation in question, a local build will
3953 @emph{always} be performed, regardless of whether or not
3954 @option{--fallback} was given.
3956 To get an idea of how many substitutes are available right now, you can
3957 try running the @command{guix weather} command (@pxref{Invoking guix
3958 weather}). This command provides statistics on the substitutes provided
3961 @node On Trusting Binaries
3962 @subsection On Trusting Binaries
3964 @cindex trust, of pre-built binaries
3965 Today, each individual's control over their own computing is at the
3966 mercy of institutions, corporations, and groups with enough power and
3967 determination to subvert the computing infrastructure and exploit its
3968 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3969 convenient, we encourage users to also build on their own, or even run
3970 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3971 interesting target. One way to help is by publishing the software you
3972 build using @command{guix publish} so that others have one more choice
3973 of server to download substitutes from (@pxref{Invoking guix publish}).
3975 Guix has the foundations to maximize build reproducibility
3976 (@pxref{Features}). In most cases, independent builds of a given
3977 package or derivation should yield bit-identical results. Thus, through
3978 a diverse set of independent package builds, we can strengthen the
3979 integrity of our systems. The @command{guix challenge} command aims to
3980 help users assess substitute servers, and to assist developers in
3981 finding out about non-deterministic package builds (@pxref{Invoking guix
3982 challenge}). Similarly, the @option{--check} option of @command{guix
3983 build} allows users to check whether previously-installed substitutes
3984 are genuine by rebuilding them locally (@pxref{build-check,
3985 @command{guix build --check}}).
3987 In the future, we want Guix to have support to publish and retrieve
3988 binaries to/from other users, in a peer-to-peer fashion. If you would
3989 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3991 @node Packages with Multiple Outputs
3992 @section Packages with Multiple Outputs
3994 @cindex multiple-output packages
3995 @cindex package outputs
3998 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3999 source package leads to exactly one directory in the store. When running
4000 @command{guix install glibc}, one installs the default output of the
4001 GNU libc package; the default output is called @code{out}, but its name
4002 can be omitted as shown in this command. In this particular case, the
4003 default output of @code{glibc} contains all the C header files, shared
4004 libraries, static libraries, Info documentation, and other supporting
4007 Sometimes it is more appropriate to separate the various types of files
4008 produced from a single source package into separate outputs. For
4009 instance, the GLib C library (used by GTK+ and related packages)
4010 installs more than 20 MiB of reference documentation as HTML pages.
4011 To save space for users who do not need it, the documentation goes to a
4012 separate output, called @code{doc}. To install the main GLib output,
4013 which contains everything but the documentation, one would run:
4019 @cindex documentation
4020 The command to install its documentation is:
4023 guix install glib:doc
4026 Some packages install programs with different ``dependency footprints''.
4027 For instance, the WordNet package installs both command-line tools and
4028 graphical user interfaces (GUIs). The former depend solely on the C
4029 library, whereas the latter depend on Tcl/Tk and the underlying X
4030 libraries. In this case, we leave the command-line tools in the default
4031 output, whereas the GUIs are in a separate output. This allows users
4032 who do not need the GUIs to save space. The @command{guix size} command
4033 can help find out about such situations (@pxref{Invoking guix size}).
4034 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
4036 There are several such multiple-output packages in the GNU distribution.
4037 Other conventional output names include @code{lib} for libraries and
4038 possibly header files, @code{bin} for stand-alone programs, and
4039 @code{debug} for debugging information (@pxref{Installing Debugging
4040 Files}). The outputs of a packages are listed in the third column of
4041 the output of @command{guix package --list-available} (@pxref{Invoking
4045 @node Invoking guix gc
4046 @section Invoking @command{guix gc}
4048 @cindex garbage collector
4050 Packages that are installed, but not used, may be @dfn{garbage-collected}.
4051 The @command{guix gc} command allows users to explicitly run the garbage
4052 collector to reclaim space from the @file{/gnu/store} directory. It is
4053 the @emph{only} way to remove files from @file{/gnu/store}---removing
4054 files or directories manually may break it beyond repair!
4057 @cindex garbage collector roots
4058 The garbage collector has a set of known @dfn{roots}: any file under
4059 @file{/gnu/store} reachable from a root is considered @dfn{live} and
4060 cannot be deleted; any other file is considered @dfn{dead} and may be
4061 deleted. The set of garbage collector roots (``GC roots'' for short)
4062 includes default user profiles; by default, the symlinks under
4063 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
4064 added with @command{guix build --root}, for example (@pxref{Invoking
4065 guix build}). The @command{guix gc --list-roots} command lists them.
4067 Prior to running @code{guix gc --collect-garbage} to make space, it is
4068 often useful to remove old generations from user profiles; that way, old
4069 package builds referenced by those generations can be reclaimed. This
4070 is achieved by running @code{guix package --delete-generations}
4071 (@pxref{Invoking guix package}).
4073 Our recommendation is to run a garbage collection periodically, or when
4074 you are short on disk space. For instance, to guarantee that at least
4075 5@tie{}GB are available on your disk, simply run:
4081 It is perfectly safe to run as a non-interactive periodic job
4082 (@pxref{Scheduled Job Execution}, for how to set up such a job).
4083 Running @command{guix gc} with no arguments will collect as
4084 much garbage as it can, but that is often inconvenient: you may find
4085 yourself having to rebuild or re-download software that is ``dead'' from
4086 the GC viewpoint but that is necessary to build other pieces of
4087 software---e.g., the compiler tool chain.
4089 The @command{guix gc} command has three modes of operation: it can be
4090 used to garbage-collect any dead files (the default), to delete specific
4091 files (the @option{--delete} option), to print garbage-collector
4092 information, or for more advanced queries. The garbage collection
4093 options are as follows:
4096 @item --collect-garbage[=@var{min}]
4097 @itemx -C [@var{min}]
4098 Collect garbage---i.e., unreachable @file{/gnu/store} files and
4099 sub-directories. This is the default operation when no option is
4102 When @var{min} is given, stop once @var{min} bytes have been collected.
4103 @var{min} may be a number of bytes, or it may include a unit as a
4104 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
4105 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
4107 When @var{min} is omitted, collect all the garbage.
4109 @item --free-space=@var{free}
4110 @itemx -F @var{free}
4111 Collect garbage until @var{free} space is available under
4112 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
4113 as @code{500MiB}, as described above.
4115 When @var{free} or more is already available in @file{/gnu/store}, do
4116 nothing and exit immediately.
4118 @item --delete-generations[=@var{duration}]
4119 @itemx -d [@var{duration}]
4120 Before starting the garbage collection process, delete all the generations
4121 older than @var{duration}, for all the user profiles; when run as root, this
4122 applies to all the profiles @emph{of all the users}.
4124 For example, this command deletes all the generations of all your profiles
4125 that are older than 2 months (except generations that are current), and then
4126 proceeds to free space until at least 10 GiB are available:
4129 guix gc -d 2m -F 10G
4134 Attempt to delete all the store files and directories specified as
4135 arguments. This fails if some of the files are not in the store, or if
4136 they are still live.
4138 @item --list-failures
4139 List store items corresponding to cached build failures.
4141 This prints nothing unless the daemon was started with
4142 @option{--cache-failures} (@pxref{Invoking guix-daemon,
4143 @option{--cache-failures}}).
4146 List the GC roots owned by the user; when run as root, list @emph{all} the GC
4150 List store items in use by currently running processes. These store
4151 items are effectively considered GC roots: they cannot be deleted.
4153 @item --clear-failures
4154 Remove the specified store items from the failed-build cache.
4156 Again, this option only makes sense when the daemon is started with
4157 @option{--cache-failures}. Otherwise, it does nothing.
4160 Show the list of dead files and directories still present in the
4161 store---i.e., files and directories no longer reachable from any root.
4164 Show the list of live store files and directories.
4168 In addition, the references among existing store files can be queried:
4174 @cindex package dependencies
4175 List the references (respectively, the referrers) of store files given
4181 List the requisites of the store files passed as arguments. Requisites
4182 include the store files themselves, their references, and the references
4183 of these, recursively. In other words, the returned list is the
4184 @dfn{transitive closure} of the store files.
4186 @xref{Invoking guix size}, for a tool to profile the size of the closure
4187 of an element. @xref{Invoking guix graph}, for a tool to visualize
4188 the graph of references.
4192 Return the derivation(s) leading to the given store items
4193 (@pxref{Derivations}).
4195 For example, this command:
4198 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
4202 returns the @file{.drv} file(s) leading to the @code{emacs} package
4203 installed in your profile.
4205 Note that there may be zero matching @file{.drv} files, for instance
4206 because these files have been garbage-collected. There can also be more
4207 than one matching @file{.drv} due to fixed-output derivations.
4210 Lastly, the following options allow you to check the integrity of the
4211 store and to control disk usage.
4215 @item --verify[=@var{options}]
4216 @cindex integrity, of the store
4217 @cindex integrity checking
4218 Verify the integrity of the store.
4220 By default, make sure that all the store items marked as valid in the
4221 database of the daemon actually exist in @file{/gnu/store}.
4223 When provided, @var{options} must be a comma-separated list containing one
4224 or more of @code{contents} and @code{repair}.
4226 When passing @option{--verify=contents}, the daemon computes the
4227 content hash of each store item and compares it against its hash in the
4228 database. Hash mismatches are reported as data corruptions. Because it
4229 traverses @emph{all the files in the store}, this command can take a
4230 long time, especially on systems with a slow disk drive.
4232 @cindex repairing the store
4233 @cindex corruption, recovering from
4234 Using @option{--verify=repair} or @option{--verify=contents,repair}
4235 causes the daemon to try to repair corrupt store items by fetching
4236 substitutes for them (@pxref{Substitutes}). Because repairing is not
4237 atomic, and thus potentially dangerous, it is available only to the
4238 system administrator. A lightweight alternative, when you know exactly
4239 which items in the store are corrupt, is @command{guix build --repair}
4240 (@pxref{Invoking guix build}).
4243 @cindex deduplication
4244 Optimize the store by hard-linking identical files---this is
4245 @dfn{deduplication}.
4247 The daemon performs deduplication after each successful build or archive
4248 import, unless it was started with @option{--disable-deduplication}
4249 (@pxref{Invoking guix-daemon, @option{--disable-deduplication}}). Thus,
4250 this option is primarily useful when the daemon was running with
4251 @option{--disable-deduplication}.
4255 @node Invoking guix pull
4256 @section Invoking @command{guix pull}
4258 @cindex upgrading Guix
4259 @cindex updating Guix
4260 @cindex @command{guix pull}
4262 @cindex security, @command{guix pull}
4263 @cindex authenticity, of code obtained with @command{guix pull}
4264 Packages are installed or upgraded to the latest version available in
4265 the distribution currently available on your local machine. To update
4266 that distribution, along with the Guix tools, you must run @command{guix
4267 pull}: the command downloads the latest Guix source code and package
4268 descriptions, and deploys it. Source code is downloaded from a
4269 @uref{https://git-scm.com, Git} repository, by default the official
4270 GNU@tie{}Guix repository, though this can be customized. @command{guix
4271 pull} ensures that the code it downloads is @emph{authentic} by
4272 verifying that commits are signed by Guix developers.
4274 Specifically, @command{guix pull} downloads code from the @dfn{channels}
4275 (@pxref{Channels}) specified by one of the followings, in this order:
4279 the @option{--channels} option;
4281 the user's @file{~/.config/guix/channels.scm} file;
4283 the system-wide @file{/etc/guix/channels.scm} file;
4285 the built-in default channels specified in the @code{%default-channels}
4289 On completion, @command{guix package} will use packages and package
4290 versions from this just-retrieved copy of Guix. Not only that, but all
4291 the Guix commands and Scheme modules will also be taken from that latest
4292 version. New @command{guix} sub-commands added by the update also
4295 Any user can update their Guix copy using @command{guix pull}, and the
4296 effect is limited to the user who ran @command{guix pull}. For
4297 instance, when user @code{root} runs @command{guix pull}, this has no
4298 effect on the version of Guix that user @code{alice} sees, and vice
4301 The result of running @command{guix pull} is a @dfn{profile} available
4302 under @file{~/.config/guix/current} containing the latest Guix. Thus,
4303 make sure to add it to the beginning of your search path so that you use
4304 the latest version, and similarly for the Info manual
4305 (@pxref{Documentation}):
4308 export PATH="$HOME/.config/guix/current/bin:$PATH"
4309 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
4312 The @option{--list-generations} or @option{-l} option lists past generations
4313 produced by @command{guix pull}, along with details about their provenance:
4317 Generation 1 Jun 10 2018 00:18:18
4319 repository URL: https://git.savannah.gnu.org/git/guix.git
4320 branch: origin/master
4321 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
4323 Generation 2 Jun 11 2018 11:02:49
4325 repository URL: https://git.savannah.gnu.org/git/guix.git
4326 branch: origin/master
4327 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
4328 2 new packages: keepalived, libnfnetlink
4329 6 packages upgraded: emacs-nix-mode@@2.0.4,
4330 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
4331 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
4333 Generation 3 Jun 13 2018 23:31:07 (current)
4335 repository URL: https://git.savannah.gnu.org/git/guix.git
4336 branch: origin/master
4337 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
4338 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
4339 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
4342 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
4343 describe the current status of Guix.
4345 This @code{~/.config/guix/current} profile works exactly like the profiles
4346 created by @command{guix package} (@pxref{Invoking guix package}). That
4347 is, you can list generations, roll back to the previous
4348 generation---i.e., the previous Guix---and so on:
4351 $ guix pull --roll-back
4352 switched from generation 3 to 2
4353 $ guix pull --delete-generations=1
4354 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
4357 You can also use @command{guix package} (@pxref{Invoking guix package})
4358 to manage the profile by naming it explicitly:
4360 $ guix package -p ~/.config/guix/current --roll-back
4361 switched from generation 3 to 2
4362 $ guix package -p ~/.config/guix/current --delete-generations=1
4363 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
4366 The @command{guix pull} command is usually invoked with no arguments,
4367 but it supports the following options:
4370 @item --url=@var{url}
4371 @itemx --commit=@var{commit}
4372 @itemx --branch=@var{branch}
4373 Download code for the @code{guix} channel from the specified @var{url}, at the
4374 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4375 string), or @var{branch}.
4377 @cindex @file{channels.scm}, configuration file
4378 @cindex configuration file for channels
4379 These options are provided for convenience, but you can also specify your
4380 configuration in the @file{~/.config/guix/channels.scm} file or using the
4381 @option{--channels} option (see below).
4383 @item --channels=@var{file}
4384 @itemx -C @var{file}
4385 Read the list of channels from @var{file} instead of
4386 @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
4387 @var{file} must contain Scheme code that
4388 evaluates to a list of channel objects. @xref{Channels}, for more
4391 @cindex channel news
4394 Display the list of packages added or upgraded since the previous
4395 generation, as well as, occasionally, news written by channel authors
4396 for their users (@pxref{Channels, Writing Channel News}).
4398 The package information is the same as displayed upon @command{guix
4399 pull} completion, but without ellipses; it is also similar to the output
4400 of @command{guix pull -l} for the last generation (see below).
4402 @item --list-generations[=@var{pattern}]
4403 @itemx -l [@var{pattern}]
4404 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
4405 is provided, the subset of generations that match @var{pattern}.
4406 The syntax of @var{pattern} is the same as with @code{guix package
4407 --list-generations} (@pxref{Invoking guix package}).
4410 @cindex rolling back
4411 @cindex undoing transactions
4412 @cindex transactions, undoing
4413 Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
4414 undo the last transaction.
4416 @item --switch-generation=@var{pattern}
4417 @itemx -S @var{pattern}
4419 Switch to a particular generation defined by @var{pattern}.
4421 @var{pattern} may be either a generation number or a number prefixed
4422 with ``+'' or ``-''. The latter means: move forward/backward by a
4423 specified number of generations. For example, if you want to return to
4424 the latest generation after @option{--roll-back}, use
4425 @option{--switch-generation=+1}.
4427 @item --delete-generations[=@var{pattern}]
4428 @itemx -d [@var{pattern}]
4429 When @var{pattern} is omitted, delete all generations except the current
4432 This command accepts the same patterns as @option{--list-generations}.
4433 When @var{pattern} is specified, delete the matching generations. When
4434 @var{pattern} specifies a duration, generations @emph{older} than the
4435 specified duration match. For instance, @option{--delete-generations=1m}
4436 deletes generations that are more than one month old.
4438 If the current generation matches, it is @emph{not} deleted.
4440 Note that deleting generations prevents rolling back to them.
4441 Consequently, this command must be used with care.
4443 @xref{Invoking guix describe}, for a way to display information about the
4444 current generation only.
4446 @item --profile=@var{profile}
4447 @itemx -p @var{profile}
4448 Use @var{profile} instead of @file{~/.config/guix/current}.
4452 Show which channel commit(s) would be used and what would be built or
4453 substituted but do not actually do it.
4455 @item --allow-downgrades
4456 Allow pulling older or unrelated revisions of channels than those
4459 @cindex downgrade attacks, protection against
4460 By default, @command{guix pull} protects against so-called ``downgrade
4461 attacks'' whereby the Git repository of a channel would be reset to an
4462 earlier or unrelated revision of itself, potentially leading you to
4463 install older, known-vulnerable versions of software packages.
4466 Make sure you understand its security implications before using
4467 @option{--allow-downgrades}.
4470 @item --disable-authentication
4471 Allow pulling channel code without authenticating it.
4473 @cindex authentication, of channel code
4474 By default, @command{guix pull} authenticates code downloaded from
4475 channels by verifying that its commits are signed by authorized
4476 developers, and raises an error if this is not the case. This option
4477 instructs it to not perform any such verification.
4480 Make sure you understand its security implications before using
4481 @option{--disable-authentication}.
4484 @item --system=@var{system}
4485 @itemx -s @var{system}
4486 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
4487 the system type of the build host.
4490 Use the bootstrap Guile to build the latest Guix. This option is only
4491 useful to Guix developers.
4494 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
4495 repository and branch to pull from, as well as @emph{additional} repositories
4496 containing package modules that should be deployed. @xref{Channels}, for more
4499 In addition, @command{guix pull} supports all the common build options
4500 (@pxref{Common Build Options}).
4502 @node Invoking guix time-machine
4503 @section Invoking @command{guix time-machine}
4505 @cindex @command{guix time-machine}
4506 @cindex pinning, channels
4507 @cindex replicating Guix
4508 @cindex reproducibility, of Guix
4510 The @command{guix time-machine} command provides access to other
4511 revisions of Guix, for example to install older versions of packages,
4512 or to reproduce a computation in an identical environment. The revision
4513 of Guix to be used is defined by a commit or by a channel
4514 description file created by @command{guix describe}
4515 (@pxref{Invoking guix describe}).
4517 The general syntax is:
4520 guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
4523 where @var{command} and @var{arg}@dots{} are passed unmodified to the
4524 @command{guix} command of the specified revision. The @var{options} that define
4525 this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
4528 @item --url=@var{url}
4529 @itemx --commit=@var{commit}
4530 @itemx --branch=@var{branch}
4531 Use the @code{guix} channel from the specified @var{url}, at the
4532 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4533 string), or @var{branch}.
4535 @item --channels=@var{file}
4536 @itemx -C @var{file}
4537 Read the list of channels from @var{file}. @var{file} must contain
4538 Scheme code that evaluates to a list of channel objects.
4539 @xref{Channels} for more information.
4542 As for @command{guix pull}, the absence of any options means that the
4543 latest commit on the master branch will be used. The command
4546 guix time-machine -- build hello
4549 will thus build the package @code{hello} as defined in the master branch,
4550 which is in general a newer revision of Guix than you have installed.
4551 Time travel works in both directions!
4553 Note that @command{guix time-machine} can trigger builds of channels and
4554 their dependencies, and these are controlled by the standard build
4555 options (@pxref{Common Build Options}).
4560 @c TODO: Remove this once we're more confident about API stability.
4562 The functionality described here is a ``technology preview'' as of version
4563 @value{VERSION}. As such, the interface is subject to change.
4567 @cindex composition of Guix revisions
4568 Sometimes you might need to mix packages from the revision of Guix you're
4569 currently running with packages available in a different revision of Guix.
4570 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
4571 revisions in arbitrary ways.
4573 @cindex inferior packages
4574 Technically, an ``inferior'' is essentially a separate Guix process connected
4575 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4576 @code{(guix inferior)} module allows you to create inferiors and to
4577 communicate with them. It also provides a high-level interface to browse and
4578 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4580 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4581 to interact with a separate revision of Guix. For example, let's assume you
4582 want to install in your profile the current @code{guile} package, along with
4583 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4584 because the newer @code{guile-json} has an incompatible API and you want to
4585 run your code against the old API@. To do that, you could write a manifest for
4586 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4587 manifest, you would create an inferior for that old Guix revision you care
4588 about, and you would look up the @code{guile-json} package in the inferior:
4591 (use-modules (guix inferior) (guix channels)
4592 (srfi srfi-1)) ;for 'first'
4595 ;; This is the old revision from which we want to
4596 ;; extract guile-json.
4599 (url "https://git.savannah.gnu.org/git/guix.git")
4601 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4604 ;; An inferior representing the above revision.
4605 (inferior-for-channels channels))
4607 ;; Now create a manifest with the current "guile" package
4608 ;; and the old "guile-json" package.
4610 (list (first (lookup-inferior-packages inferior "guile-json"))
4611 (specification->package "guile")))
4614 On its first run, @command{guix package --manifest} might have to build the
4615 channel you specified before it can create the inferior; subsequent runs will
4616 be much faster because the Guix revision will be cached.
4618 The @code{(guix inferior)} module provides the following procedures to open an
4621 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4622 [#:cache-directory] [#:ttl]
4623 Return an inferior for @var{channels}, a list of channels. Use the cache at
4624 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4625 This procedure opens a new connection to the build daemon.
4627 As a side effect, this procedure may build or substitute binaries for
4628 @var{channels}, which can take time.
4631 @deffn {Scheme Procedure} open-inferior @var{directory} @
4632 [#:command "bin/guix"]
4633 Open the inferior Guix in @var{directory}, running
4634 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4635 the inferior could not be launched.
4638 @cindex inferior packages
4639 The procedures listed below allow you to obtain and manipulate inferior
4642 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4643 Return the list of packages known to @var{inferior}.
4646 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4648 Return the sorted list of inferior packages matching @var{name} in
4649 @var{inferior}, with highest version numbers first. If @var{version} is true,
4650 return only packages with a version number prefixed by @var{version}.
4653 @deffn {Scheme Procedure} inferior-package? @var{obj}
4654 Return true if @var{obj} is an inferior package.
4657 @deffn {Scheme Procedure} inferior-package-name @var{package}
4658 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4659 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4660 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4661 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4662 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4663 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4664 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4665 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4666 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4667 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4668 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4669 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4670 These procedures are the counterpart of package record accessors
4671 (@pxref{package Reference}). Most of them work by querying the inferior
4672 @var{package} comes from, so the inferior must still be live when you call
4676 Inferior packages can be used transparently like any other package or
4677 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4678 transparently handled by the @code{packages->manifest} procedure, which is
4679 commonly use in manifests (@pxref{Invoking guix package, the
4680 @option{--manifest} option of @command{guix package}}). Thus you can insert
4681 an inferior package pretty much anywhere you would insert a regular package:
4682 in manifests, in the @code{packages} field of your @code{operating-system}
4683 declaration, and so on.
4685 @node Invoking guix describe
4686 @section Invoking @command{guix describe}
4688 @cindex reproducibility
4689 @cindex replicating Guix
4690 Often you may want to answer questions like: ``Which revision of Guix am I
4691 using?'' or ``Which channels am I using?'' This is useful information in many
4692 situations: if you want to @emph{replicate} an environment on a different
4693 machine or user account, if you want to report a bug or to determine what
4694 change in the channels you are using caused it, or if you want to record your
4695 system state for reproducibility purposes. The @command{guix describe}
4696 command answers these questions.
4698 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4699 displays the channel(s) that it was built from, including their repository URL
4700 and commit IDs (@pxref{Channels}):
4704 Generation 10 Sep 03 2018 17:32:44 (current)
4706 repository URL: https://git.savannah.gnu.org/git/guix.git
4708 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4711 If you're familiar with the Git version control system, this is similar in
4712 spirit to @command{git describe}; the output is also similar to that of
4713 @command{guix pull --list-generations}, but limited to the current generation
4714 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4715 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4716 information is all it takes to describe the revision of Guix you're using, and
4717 also to replicate it.
4719 To make it easier to replicate Guix, @command{guix describe} can also be asked
4720 to return a list of channels instead of the human-readable description above:
4723 $ guix describe -f channels
4726 (url "https://git.savannah.gnu.org/git/guix.git")
4728 "e0fa68c7718fffd33d81af415279d6ddb518f727")
4730 (make-channel-introduction
4731 "9edb3f66fd807b096b48283debdcddccfea34bad"
4732 (openpgp-fingerprint
4733 "BBB0 2DDF 2CEA F6A8 0D1D E643 A2A0 6DF2 A33A 54FA")))))
4737 You can save this to a file and feed it to @command{guix pull -C} on some
4738 other machine or at a later point in time, which will instantiate @emph{this
4739 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4740 From there on, since you're able to deploy the same revision of Guix, you can
4741 just as well @emph{replicate a complete software environment}. We humbly
4742 think that this is @emph{awesome}, and we hope you'll like it too!
4744 The details of the options supported by @command{guix describe} are as
4748 @item --format=@var{format}
4749 @itemx -f @var{format}
4750 Produce output in the specified @var{format}, one of:
4754 produce human-readable output;
4756 produce a list of channel specifications that can be passed to @command{guix
4757 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4759 @item channels-sans-intro
4760 like @code{channels}, but omit the @code{introduction} field; use it to
4761 produce a channel specification suitable for Guix version 1.1.0 or
4762 earlier---the @code{introduction} field has to do with channel
4763 authentication (@pxref{Channels, Channel Authentication}) and is not
4764 supported by these older versions;
4767 produce a list of channel specifications in JSON format;
4769 produce a list of channel specifications in Recutils format.
4772 @item --list-formats
4773 Display available formats for @option{--format} option.
4775 @item --profile=@var{profile}
4776 @itemx -p @var{profile}
4777 Display information about @var{profile}.
4780 @node Invoking guix archive
4781 @section Invoking @command{guix archive}
4783 @cindex @command{guix archive}
4785 The @command{guix archive} command allows users to @dfn{export} files
4786 from the store into a single archive, and to later @dfn{import} them on
4787 a machine that runs Guix.
4788 In particular, it allows store files to be transferred from one machine
4789 to the store on another machine.
4792 If you're looking for a way to produce archives in a format suitable for
4793 tools other than Guix, @pxref{Invoking guix pack}.
4796 @cindex exporting store items
4797 To export store files as an archive to standard output, run:
4800 guix archive --export @var{options} @var{specifications}...
4803 @var{specifications} may be either store file names or package
4804 specifications, as for @command{guix package} (@pxref{Invoking guix
4805 package}). For instance, the following command creates an archive
4806 containing the @code{gui} output of the @code{git} package and the main
4807 output of @code{emacs}:
4810 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4813 If the specified packages are not built yet, @command{guix archive}
4814 automatically builds them. The build process may be controlled with the
4815 common build options (@pxref{Common Build Options}).
4817 To transfer the @code{emacs} package to a machine connected over SSH,
4821 guix archive --export -r emacs | ssh the-machine guix archive --import
4825 Similarly, a complete user profile may be transferred from one machine
4826 to another like this:
4829 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4830 ssh the-machine guix archive --import
4834 However, note that, in both examples, all of @code{emacs} and the
4835 profile as well as all of their dependencies are transferred (due to
4836 @option{-r}), regardless of what is already available in the store on
4837 the target machine. The @option{--missing} option can help figure out
4838 which items are missing from the target store. The @command{guix copy}
4839 command simplifies and optimizes this whole process, so this is probably
4840 what you should use in this case (@pxref{Invoking guix copy}).
4842 @cindex nar, archive format
4843 @cindex normalized archive (nar)
4844 @cindex nar bundle, archive format
4845 Each store item is written in the @dfn{normalized archive} or @dfn{nar}
4846 format (described below), and the output of @command{guix archive
4847 --export} (and input of @command{guix archive --import}) is a @dfn{nar
4851 comparable in spirit to `tar', but with differences
4852 that make it more appropriate for our purposes. First, rather than
4853 recording all Unix metadata for each file, the nar format only mentions
4854 the file type (regular, directory, or symbolic link); Unix permissions
4855 and owner/group are dismissed. Second, the order in which directory
4856 entries are stored always follows the order of file names according to
4857 the C locale collation order. This makes archive production fully
4860 That nar bundle format is essentially the concatenation of zero or more
4861 nars along with metadata for each store item it contains: its file name,
4862 references, corresponding derivation, and a digital signature.
4864 When exporting, the daemon digitally signs the contents of the archive,
4865 and that digital signature is appended. When importing, the daemon
4866 verifies the signature and rejects the import in case of an invalid
4867 signature or if the signing key is not authorized.
4868 @c FIXME: Add xref to daemon doc about signatures.
4870 The main options are:
4874 Export the specified store files or packages (see below). Write the
4875 resulting archive to the standard output.
4877 Dependencies are @emph{not} included in the output, unless
4878 @option{--recursive} is passed.
4882 When combined with @option{--export}, this instructs @command{guix archive}
4883 to include dependencies of the given items in the archive. Thus, the
4884 resulting archive is self-contained: it contains the closure of the
4885 exported store items.
4888 Read an archive from the standard input, and import the files listed
4889 therein into the store. Abort if the archive has an invalid digital
4890 signature, or if it is signed by a public key not among the authorized
4891 keys (see @option{--authorize} below).
4894 Read a list of store file names from the standard input, one per line,
4895 and write on the standard output the subset of these files missing from
4898 @item --generate-key[=@var{parameters}]
4899 @cindex signing, archives
4900 Generate a new key pair for the daemon. This is a prerequisite before
4901 archives can be exported with @option{--export}. This
4902 operation is usually instantaneous but it can take time if the system's
4903 entropy pool needs to be refilled. On Guix System,
4904 @code{guix-service-type} takes care of generating this key pair the
4907 The generated key pair is typically stored under @file{/etc/guix}, in
4908 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4909 key, which must be kept secret). When @var{parameters} is omitted,
4910 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4911 versions before 1.6.0, it is a 4096-bit RSA key.
4912 Alternatively, @var{parameters} can specify
4913 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4914 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4915 Libgcrypt Reference Manual}).
4918 @cindex authorizing, archives
4919 Authorize imports signed by the public key passed on standard input.
4920 The public key must be in ``s-expression advanced format''---i.e., the
4921 same format as the @file{signing-key.pub} file.
4923 The list of authorized keys is kept in the human-editable file
4924 @file{/etc/guix/acl}. The file contains
4925 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4926 s-expressions''} and is structured as an access-control list in the
4927 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4930 @item --extract=@var{directory}
4931 @itemx -x @var{directory}
4932 Read a single-item archive as served by substitute servers
4933 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4934 low-level operation needed in only very narrow use cases; see below.
4936 For example, the following command extracts the substitute for Emacs
4937 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4941 https://@value{SUBSTITUTE-SERVER}/nar/gzip/@dots{}-emacs-24.5 \
4942 | gunzip | guix archive -x /tmp/emacs
4945 Single-item archives are different from multiple-item archives produced
4946 by @command{guix archive --export}; they contain a single store item,
4947 and they do @emph{not} embed a signature. Thus this operation does
4948 @emph{no} signature verification and its output should be considered
4951 The primary purpose of this operation is to facilitate inspection of
4952 archive contents coming from possibly untrusted substitute servers
4953 (@pxref{Invoking guix challenge}).
4957 Read a single-item archive as served by substitute servers
4958 (@pxref{Substitutes}) and print the list of files it contains, as in
4963 https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-emacs-26.3 \
4964 | lzip -d | guix archive -t
4969 @c *********************************************************************
4974 @cindex @file{channels.scm}, configuration file
4975 @cindex configuration file for channels
4976 @cindex @command{guix pull}, configuration file
4977 @cindex configuration of @command{guix pull}
4978 Guix and its package collection are updated by running @command{guix pull}
4979 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
4980 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
4981 customized by defining @dfn{channels} in the
4982 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
4983 of a Git repository to be deployed, and @command{guix pull} can be instructed
4984 to pull from one or more channels. In other words, channels can be used
4985 to @emph{customize} and to @emph{extend} Guix, as we will see below.
4986 Guix is able to take into account security concerns and deal with authenticated
4990 * Specifying Additional Channels:: Extending the package collection.
4991 * Using a Custom Guix Channel:: Using a customized Guix.
4992 * Replicating Guix:: Running the @emph{exact same} Guix.
4993 * Channel Authentication:: How Guix verifies what it fetches.
4994 * Creating a Channel:: How to write your custom channel.
4995 * Package Modules in a Sub-directory:: Specifying the channel's package modules location.
4996 * Declaring Channel Dependencies:: How to depend on other channels.
4997 * Specifying Channel Authorizations:: Defining channel authors authorizations.
4998 * Primary URL:: Distinguishing mirror to original.
4999 * Writing Channel News:: Communicating information to channel's users.
5000 * Channels with Substitutes:: Using channels with available substitutes.
5003 @node Specifying Additional Channels
5004 @section Specifying Additional Channels
5006 @cindex extending the package collection (channels)
5007 @cindex variant packages (channels)
5008 You can specify @emph{additional channels} to pull from. To use a channel, write
5009 @code{~/.config/guix/channels.scm} to instruct @command{guix pull} to pull from it
5010 @emph{in addition} to the default Guix channel(s):
5012 @vindex %default-channels
5014 ;; Add variant packages to those Guix provides.
5016 (name 'variant-packages)
5017 (url "https://example.org/variant-packages.git"))
5022 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
5023 add a channel the list of channels that the variable @code{%default-channels}
5024 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
5025 Manual}). With this file in place, @command{guix pull} builds not only Guix
5026 but also the package modules from your own repository. The result in
5027 @file{~/.config/guix/current} is the union of Guix with your own package
5031 $ guix pull --list-generations
5033 Generation 19 Aug 27 2018 16:20:48
5035 repository URL: https://git.savannah.gnu.org/git/guix.git
5037 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
5038 variant-packages dd3df5e
5039 repository URL: https://example.org/variant-packages.git
5041 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
5042 11 new packages: variant-gimp, variant-emacs-with-cool-features, @dots{}
5043 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
5047 The output of @command{guix pull} above shows that Generation@tie{}19 includes
5048 both Guix and packages from the @code{variant-personal-packages} channel. Among
5049 the new and upgraded packages that are listed, some like @code{variant-gimp} and
5050 @code{variant-emacs-with-cool-features} might come from
5051 @code{variant-packages}, while others come from the Guix default channel.
5053 @node Using a Custom Guix Channel
5054 @section Using a Custom Guix Channel
5056 The channel called @code{guix} specifies where Guix itself---its command-line
5057 tools as well as its package collection---should be downloaded. For instance,
5058 suppose you want to update from another copy of the Guix repository at
5059 @code{example.org}, and specifically the @code{super-hacks} branch, you can
5060 write in @code{~/.config/guix/channels.scm} this specification:
5063 ;; Tell 'guix pull' to use another repo.
5066 (url "https://example.org/another-guix.git")
5067 (branch "super-hacks")))
5071 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
5072 branch of the repository at @code{example.org}. The authentication concern is
5073 addressed below ((@pxref{Channel Authentication}).
5075 @node Replicating Guix
5076 @section Replicating Guix
5078 @cindex pinning, channels
5079 @cindex replicating Guix
5080 @cindex reproducibility, of Guix
5081 The @command{guix pull --list-generations} output above shows precisely which
5082 commits were used to build this instance of Guix. We can thus replicate it,
5083 say, on another machine, by providing a channel specification in
5084 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
5087 ;; Deploy specific commits of my channels of interest.
5090 (url "https://git.savannah.gnu.org/git/guix.git")
5091 (commit "6298c3ffd9654d3231a6f25390b056483e8f407c"))
5093 (name 'variant-packages)
5094 (url "https://example.org/variant-packages.git")
5095 (commit "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
5098 The @command{guix describe --format=channels} command can even generate this
5099 list of channels directly (@pxref{Invoking guix describe}). The resulting
5100 file can be used with the -C options of @command{guix pull}
5101 (@pxref{Invoking guix pull}) or @command{guix time-machine}
5102 (@pxref{Invoking guix time-machine}).
5104 At this point the two machines run the @emph{exact same Guix}, with access to
5105 the @emph{exact same packages}. The output of @command{guix build gimp} on
5106 one machine will be exactly the same, bit for bit, as the output of the same
5107 command on the other machine. It also means both machines have access to all
5108 the source code of Guix and, transitively, to all the source code of every
5111 This gives you super powers, allowing you to track the provenance of binary
5112 artifacts with very fine grain, and to reproduce software environments at
5113 will---some sort of ``meta reproducibility'' capabilities, if you will.
5114 @xref{Inferiors}, for another way to take advantage of these super powers.
5116 @node Channel Authentication
5117 @section Channel Authentication
5119 @anchor{channel-authentication}
5120 @cindex authentication, of channel code
5121 The @command{guix pull} and @command{guix time-machine} commands
5122 @dfn{authenticate} the code retrieved from channels: they make sure each
5123 commit that is fetched is signed by an authorized developer. The goal
5124 is to protect from unauthorized modifications to the channel that would
5125 lead users to run malicious code.
5127 As a user, you must provide a @dfn{channel introduction} in your
5128 channels file so that Guix knows how to authenticate its first commit.
5129 A channel specification, including its introduction, looks something
5134 (name 'some-channel)
5135 (url "https://example.org/some-channel.git")
5137 (make-channel-introduction
5138 "6f0d8cc0d88abb59c324b2990bfee2876016bb86"
5139 (openpgp-fingerprint
5140 "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
5143 The specification above shows the name and URL of the channel. The call
5144 to @code{make-channel-introduction} above specifies that authentication
5145 of this channel starts at commit @code{6f0d8cc@dots{}}, which is signed
5146 by the OpenPGP key with fingerprint @code{CABB A931@dots{}}.
5148 For the main channel, called @code{guix}, you automatically get that
5149 information from your Guix installation. For other channels, include
5150 the channel introduction provided by the channel authors in your
5151 @file{channels.scm} file. Make sure you retrieve the channel
5152 introduction from a trusted source since that is the root of your trust.
5154 If you're curious about the authentication mechanics, read on!
5156 @node Creating a Channel
5157 @section Creating a Channel
5159 @cindex personal packages (channels)
5160 @cindex channels, for personal packages
5161 Let's say you have a bunch of custom package variants or personal packages
5162 that you think would make little sense to contribute to the Guix project, but
5163 would like to have these packages transparently available to you at the
5164 command line. You would first write modules containing those package
5165 definitions (@pxref{Package Modules}), maintain them in a Git repository, and
5166 then you and anyone else can use it as an additional channel to get packages
5169 @c What follows stems from discussions at
5170 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
5171 @c earlier discussions on guix-devel@gnu.org.
5173 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
5174 publish your personal channel to the world, we would like to share a few words
5179 Before publishing a channel, please consider contributing your package
5180 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
5181 to free software of all sorts, and packages in Guix proper are readily
5182 available to all Guix users and benefit from the project's quality assurance
5186 When you maintain package definitions outside Guix, we, Guix developers,
5187 consider that @emph{the compatibility burden is on you}. Remember that
5188 package modules and package definitions are just Scheme code that uses various
5189 programming interfaces (APIs). We want to remain free to change these APIs to
5190 keep improving Guix, possibly in ways that break your channel. We never
5191 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
5195 Corollary: if you're using an external channel and that channel breaks, please
5196 @emph{report the issue to the channel authors}, not to the Guix project.
5199 You've been warned! Having said this, we believe external channels are a
5200 practical way to exert your freedom to augment Guix' package collection and to
5201 share your improvements, which are basic tenets of
5202 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
5203 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
5206 To create a channel, create a Git repository containing your own package
5207 modules and make it available. The repository can contain anything, but a
5208 useful channel will contain Guile modules that export packages. Once you
5209 start using a channel, Guix will behave as if the root directory of that
5210 channel's Git repository has been added to the Guile load path (@pxref{Load
5211 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
5212 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
5213 module, then the module will be available under the name @code{(my-packages
5214 my-tools)}, and you will be able to use it like any other module
5215 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
5217 As a channel author, consider bundling authentication material with your
5218 channel so that users can authenticate it. @xref{Channel
5219 Authentication}, and @ref{Specifying Channel Authorizations}, for info
5223 @node Package Modules in a Sub-directory
5224 @section Package Modules in a Sub-directory
5226 @cindex subdirectory, channels
5227 As a channel author, you may want to keep your channel modules in a
5228 sub-directory. If your modules are in the sub-directory @file{guix}, you must
5229 add a meta-data file @file{.guix-channel} that contains:
5237 @node Declaring Channel Dependencies
5238 @section Declaring Channel Dependencies
5240 @cindex dependencies, channels
5241 @cindex meta-data, channels
5242 Channel authors may decide to augment a package collection provided by other
5243 channels. They can declare their channel to be dependent on other channels in
5244 a meta-data file @file{.guix-channel}, which is to be placed in the root of
5245 the channel repository.
5247 The meta-data file should contain a simple S-expression like this:
5254 (name 'some-collection)
5255 (url "https://example.org/first-collection.git")
5257 ;; The 'introduction' bit below is optional: you would
5258 ;; provide it for dependencies that can be authenticated.
5260 (channel-introduction
5262 (commit "a8883b58dc82e167c96506cf05095f37c2c2c6cd")
5263 (signer "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
5265 (name 'some-other-collection)
5266 (url "https://example.org/second-collection.git")
5267 (branch "testing"))))
5270 In the above example this channel is declared to depend on two other channels,
5271 which will both be fetched automatically. The modules provided by the channel
5272 will be compiled in an environment where the modules of all these declared
5273 channels are available.
5275 For the sake of reliability and maintainability, you should avoid dependencies
5276 on channels that you don't control, and you should aim to keep the number of
5277 dependencies to a minimum.
5279 @node Specifying Channel Authorizations
5280 @section Specifying Channel Authorizations
5282 @cindex channel authorizations
5283 @anchor{channel-authorizations}
5284 As we saw above, Guix ensures the source code it pulls from channels
5285 comes from authorized developers. As a channel author, you need to
5286 specify the list of authorized developers in the
5287 @file{.guix-authorizations} file in the channel's Git repository. The
5288 authentication rule is simple: each commit must be signed by a key
5289 listed in the @file{.guix-authorizations} file of its parent
5290 commit(s)@footnote{Git commits form a @dfn{directed acyclic graph}
5291 (DAG). Each commit can have zero or more parents; ``regular'' commits
5292 have one parent and merge commits have two parent commits. Read
5293 @uref{https://eagain.net/articles/git-for-computer-scientists/, @i{Git
5294 for Computer Scientists}} for a great overview.} The
5295 @file{.guix-authorizations} file looks like this:
5298 ;; Example '.guix-authorizations' file.
5301 (version 0) ;current file format version
5303 (("AD17 A21E F8AE D8F1 CC02 DBD9 F8AE D8F1 765C 61E3"
5305 ("2A39 3FFF 68F4 EF7A 3D29 12AF 68F4 EF7A 22FB B2D5"
5307 ("CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"
5311 Each fingerprint is followed by optional key/value pairs, as in the
5312 example above. Currently these key/value pairs are ignored.
5314 This authentication rule creates a chicken-and-egg issue: how do we
5315 authenticate the first commit? Related to that: how do we deal with
5316 channels whose repository history contains unsigned commits and lack
5317 @file{.guix-authorizations}? And how do we fork existing channels?
5319 @cindex channel introduction
5320 Channel introductions answer these questions by describing the first
5321 commit of a channel that should be authenticated. The first time a
5322 channel is fetched with @command{guix pull} or @command{guix
5323 time-machine}, the command looks up the introductory commit and verifies
5324 that it is signed by the specified OpenPGP key. From then on, it
5325 authenticates commits according to the rule above.
5327 Additionally, your channel must provide all the OpenPGP keys that were
5328 ever mentioned in @file{.guix-authorizations}, stored as @file{.key}
5329 files, which can be either binary or ``ASCII-armored''. By default,
5330 those @file{.key} files are searched for in the branch named
5331 @code{keyring} but you can specify a different branch name in
5332 @code{.guix-channel} like so:
5337 (keyring-reference "my-keyring-branch"))
5340 To summarize, as the author of a channel, there are three things you have
5341 to do to allow users to authenticate your code:
5345 Export the OpenPGP keys of past and present committers with @command{gpg
5346 --export} and store them in @file{.key} files, by default in a branch
5347 named @code{keyring} (we recommend making it an @dfn{orphan branch}).
5350 Introduce an initial @file{.guix-authorizations} in the channel's
5351 repository. Do that in a signed commit (@pxref{Commit Access}, for
5352 information on how to sign Git commits.)
5355 Advertise the channel introduction, for instance on your channel's web
5356 page. The channel introduction, as we saw above, is the commit/key
5357 pair---i.e., the commit that introduced @file{.guix-authorizations}, and
5358 the fingerprint of the OpenPGP used to sign it.
5361 Before pushing to your public Git repository, you can run @command{guix
5362 git-authenticate} to verify that you did sign all the commits you are
5363 about to push with an authorized key:
5366 guix git authenticate @var{commit} @var{signer}
5370 where @var{commit} and @var{signer} are your channel introduction.
5371 @xref{Invoking guix git authenticate}, for details.
5373 Publishing a signed channel requires discipline: any mistake, such as an
5374 unsigned commit or a commit signed by an unauthorized key, will prevent
5375 users from pulling from your channel---well, that's the whole point of
5376 authentication! Pay attention to merges in particular: merge commits
5377 are considered authentic if and only if they are signed by a key present
5378 in the @file{.guix-authorizations} file of @emph{both} branches.
5381 @section Primary URL
5383 @cindex primary URL, channels
5384 Channel authors can indicate the primary URL of their channel's Git
5385 repository in the @file{.guix-channel} file, like so:
5390 (url "https://example.org/guix.git"))
5393 This allows @command{guix pull} to determine whether it is pulling code
5394 from a mirror of the channel; when that is the case, it warns the user
5395 that the mirror might be stale and displays the primary URL@. That way,
5396 users cannot be tricked into fetching code from a stale mirror that does
5397 not receive security updates.
5399 This feature only makes sense for authenticated repositories, such as
5400 the official @code{guix} channel, for which @command{guix pull} ensures
5401 the code it fetches is authentic.
5403 @node Writing Channel News
5404 @section Writing Channel News
5406 @cindex news, for channels
5407 Channel authors may occasionally want to communicate to their users
5408 information about important changes in the channel. You'd send them all
5409 an email, but that's not convenient.
5411 Instead, channels can provide a @dfn{news file}; when the channel users
5412 run @command{guix pull}, that news file is automatically read and
5413 @command{guix pull --news} can display the announcements that correspond
5414 to the new commits that have been pulled, if any.
5416 To do that, channel authors must first declare the name of the news file
5417 in their @file{.guix-channel} file:
5422 (news-file "etc/news.txt"))
5425 The news file itself, @file{etc/news.txt} in this example, must look
5426 something like this:
5431 (entry (tag "the-bug-fix")
5432 (title (en "Fixed terrible bug")
5434 (body (en "@@emph@{Good news@}! It's fixed!")
5435 (eo "Certe ĝi pli bone funkcias nun!")))
5436 (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
5437 (title (en "Added a great package")
5438 (ca "Què vol dir guix?"))
5439 (body (en "Don't miss the @@code@{hello@} package!"))))
5442 While the news file is using the Scheme syntax, avoid naming it with a
5443 @file{.scm} extension or else it will get picked up when building the
5444 channel and yield an error since it is not a valid module.
5445 Alternatively, you can move the channel module to a subdirectory and
5446 store the news file in another directory.
5448 The file consists of a list of @dfn{news entries}. Each entry is
5449 associated with a commit or tag: it describes changes made in this
5450 commit, possibly in preceding commits as well. Users see entries only
5451 the first time they obtain the commit the entry refers to.
5453 The @code{title} field should be a one-line summary while @code{body}
5454 can be arbitrarily long, and both can contain Texinfo markup
5455 (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
5456 a list of language tag/message tuples, which allows @command{guix pull}
5457 to display news in the language that corresponds to the user's locale.
5459 If you want to translate news using a gettext-based workflow, you can
5460 extract translatable strings with @command{xgettext} (@pxref{xgettext
5461 Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
5462 you write news entries in English first, the command below creates a PO
5463 file containing the strings to translate:
5466 xgettext -o news.po -l scheme -ken etc/news.txt
5469 To sum up, yes, you could use your channel as a blog. But beware, this
5470 is @emph{not quite} what your users might expect.
5472 @node Channels with Substitutes
5473 @section Channels with Substitutes
5475 When running @command{guix pull}, Guix will first compile the
5476 definitions of every available package. This is an expensive operation
5477 for which substitutes (@pxref{Substitutes}) may be available. The
5478 following snippet in @file{channels.scm} will ensure that @command{guix
5479 pull} uses the latest commit with available substitutes for the package
5480 definitions: this is done by querying the continuous integration
5481 server at @url{https://ci.guix.gnu.org}.
5484 (use-modules (guix ci))
5486 (list (channel-with-substitutes-available
5487 %default-guix-channel
5488 "https://ci.guix.gnu.org"))
5491 Note that this does not mean that all the packages that you will
5492 install after running @command{guix pull} will have available
5493 substitutes. It only ensures that @command{guix pull} will not try to
5494 compile package definitions. This is particularly useful when using
5495 machines with limited resources.
5497 @c *********************************************************************
5499 @chapter Development
5501 @cindex software development
5502 If you are a software developer, Guix provides tools that you should find
5503 helpful---independently of the language you're developing in. This is what
5504 this chapter is about.
5506 The @command{guix environment} command provides a convenient way to set up
5507 @dfn{development environments} containing all the dependencies and tools
5508 necessary to work on the software package of your choice. The @command{guix
5509 pack} command allows you to create @dfn{application bundles} that can be
5510 easily distributed to users who do not run Guix.
5513 * Invoking guix environment:: Setting up development environments.
5514 * Invoking guix pack:: Creating software bundles.
5515 * The GCC toolchain:: Working with languages supported by GCC.
5516 * Invoking guix git authenticate:: Authenticating Git repositories.
5519 @node Invoking guix environment
5520 @section Invoking @command{guix environment}
5522 @cindex reproducible build environments
5523 @cindex development environments
5524 @cindex @command{guix environment}
5525 @cindex environment, package build environment
5526 The purpose of @command{guix environment} is to assist hackers in
5527 creating reproducible development environments without polluting their
5528 package profile. The @command{guix environment} tool takes one or more
5529 packages, builds all of their inputs, and creates a shell
5530 environment to use them.
5532 The general syntax is:
5535 guix environment @var{options} @var{package}@dots{}
5538 The following example spawns a new shell set up for the development of
5542 guix environment guile
5545 If the needed dependencies are not built yet, @command{guix environment}
5546 automatically builds them. The environment of the new shell is an
5547 augmented version of the environment that @command{guix environment} was
5548 run in. It contains the necessary search paths for building the given
5549 package added to the existing environment variables. To create
5550 a ``pure'' environment, in which the original environment variables have
5551 been unset, use the @option{--pure} option@footnote{Users sometimes
5552 wrongfully augment environment variables such as @env{PATH} in their
5553 @file{~/.bashrc} file. As a consequence, when @command{guix
5554 environment} launches it, Bash may read @file{~/.bashrc}, thereby
5555 introducing ``impurities'' in these environment variables. It is an
5556 error to define such environment variables in @file{.bashrc}; instead,
5557 they should be defined in @file{.bash_profile}, which is sourced only by
5558 log-in shells. @xref{Bash Startup Files,,, bash, The GNU Bash Reference
5559 Manual}, for details on Bash start-up files.}.
5561 @vindex GUIX_ENVIRONMENT
5562 @command{guix environment} defines the @env{GUIX_ENVIRONMENT}
5563 variable in the shell it spawns; its value is the file name of the
5564 profile of this environment. This allows users to, say, define a
5565 specific prompt for development environments in their @file{.bashrc}
5566 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
5569 if [ -n "$GUIX_ENVIRONMENT" ]
5571 export PS1="\u@@\h \w [dev]\$ "
5576 ...@: or to browse the profile:
5579 $ ls "$GUIX_ENVIRONMENT/bin"
5582 Additionally, more than one package may be specified, in which case the
5583 union of the inputs for the given packages are used. For example, the
5584 command below spawns a shell where all of the dependencies of both Guile
5585 and Emacs are available:
5588 guix environment guile emacs
5591 Sometimes an interactive shell session is not desired. An arbitrary
5592 command may be invoked by placing the @code{--} token to separate the
5593 command from the rest of the arguments:
5596 guix environment guile -- make -j4
5599 In other situations, it is more convenient to specify the list of
5600 packages needed in the environment. For example, the following command
5601 runs @command{python} from an environment containing Python@tie{}2.7 and
5605 guix environment --ad-hoc python2-numpy python-2.7 -- python
5608 Furthermore, one might want the dependencies of a package and also some
5609 additional packages that are not build-time or runtime dependencies, but
5610 are useful when developing nonetheless. Because of this, the
5611 @option{--ad-hoc} flag is positional. Packages appearing before
5612 @option{--ad-hoc} are interpreted as packages whose dependencies will be
5613 added to the environment. Packages appearing after are interpreted as
5614 packages that will be added to the environment directly. For example,
5615 the following command creates a Guix development environment that
5616 additionally includes Git and strace:
5619 guix environment --pure guix --ad-hoc git strace
5623 Sometimes it is desirable to isolate the environment as much as
5624 possible, for maximal purity and reproducibility. In particular, when
5625 using Guix on a host distro that is not Guix System, it is desirable to
5626 prevent access to @file{/usr/bin} and other system-wide resources from
5627 the development environment. For example, the following command spawns
5628 a Guile REPL in a ``container'' where only the store and the current
5629 working directory are mounted:
5632 guix environment --ad-hoc --container guile -- guile
5636 The @option{--container} option requires Linux-libre 3.19 or newer.
5639 @cindex certificates
5640 Another typical use case for containers is to run security-sensitive
5641 applications such as a web browser. To run Eolie, we must expose and
5642 share some files and directories; we include @code{nss-certs} and expose
5643 @file{/etc/ssl/certs/} for HTTPS authentication; finally we preserve the
5644 @env{DISPLAY} environment variable since containerized graphical
5645 applications won't display without it.
5648 guix environment --preserve='^DISPLAY$' --container --network \
5649 --expose=/etc/machine-id \
5650 --expose=/etc/ssl/certs/ \
5651 --share=$HOME/.local/share/eolie/=$HOME/.local/share/eolie/ \
5652 --ad-hoc eolie nss-certs dbus -- eolie
5655 The available options are summarized below.
5658 @item --root=@var{file}
5659 @itemx -r @var{file}
5660 @cindex persistent environment
5661 @cindex garbage collector root, for environments
5662 Make @var{file} a symlink to the profile for this environment, and
5663 register it as a garbage collector root.
5665 This is useful if you want to protect your environment from garbage
5666 collection, to make it ``persistent''.
5668 When this option is omitted, the environment is protected from garbage
5669 collection only for the duration of the @command{guix environment}
5670 session. This means that next time you recreate the same environment,
5671 you could have to rebuild or re-download packages. @xref{Invoking guix
5672 gc}, for more on GC roots.
5674 @item --expression=@var{expr}
5675 @itemx -e @var{expr}
5676 Create an environment for the package or list of packages that
5677 @var{expr} evaluates to.
5679 For example, running:
5682 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
5685 starts a shell with the environment for this specific variant of the
5691 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
5694 starts a shell with all the base system packages available.
5696 The above commands only use the default output of the given packages.
5697 To select other outputs, two element tuples can be specified:
5700 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
5703 @item --load=@var{file}
5704 @itemx -l @var{file}
5705 Create an environment for the package or list of packages that the code
5706 within @var{file} evaluates to.
5708 As an example, @var{file} might contain a definition like this
5709 (@pxref{Defining Packages}):
5712 @verbatiminclude environment-gdb.scm
5715 @item --manifest=@var{file}
5716 @itemx -m @var{file}
5717 Create an environment for the packages contained in the manifest object
5718 returned by the Scheme code in @var{file}. This option can be repeated
5719 several times, in which case the manifests are concatenated.
5721 This is similar to the same-named option in @command{guix package}
5722 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
5726 Include all specified packages in the resulting environment, as if an
5727 @i{ad hoc} package were defined with them as inputs. This option is
5728 useful for quickly creating an environment without having to write a
5729 package expression to contain the desired inputs.
5731 For instance, the command:
5734 guix environment --ad-hoc guile guile-sdl -- guile
5737 runs @command{guile} in an environment where Guile and Guile-SDL are
5740 Note that this example implicitly asks for the default output of
5741 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
5742 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
5743 of @code{glib} (@pxref{Packages with Multiple Outputs}).
5745 This option may be composed with the default behavior of @command{guix
5746 environment}. Packages appearing before @option{--ad-hoc} are
5747 interpreted as packages whose dependencies will be added to the
5748 environment, the default behavior. Packages appearing after are
5749 interpreted as packages that will be added to the environment directly.
5752 Unset existing environment variables when building the new environment, except
5753 those specified with @option{--preserve} (see below). This has the effect of
5754 creating an environment in which search paths only contain package inputs.
5756 @item --preserve=@var{regexp}
5757 @itemx -E @var{regexp}
5758 When used alongside @option{--pure}, preserve the environment variables
5759 matching @var{regexp}---in other words, put them on a ``white list'' of
5760 environment variables that must be preserved. This option can be repeated
5764 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
5768 This example runs @command{mpirun} in a context where the only environment
5769 variables defined are @env{PATH}, environment variables whose name starts
5770 with @samp{SLURM}, as well as the usual ``precious'' variables (@env{HOME},
5773 @item --search-paths
5774 Display the environment variable definitions that make up the
5777 @item --system=@var{system}
5778 @itemx -s @var{system}
5779 Attempt to build for @var{system}---e.g., @code{i686-linux}.
5784 Run @var{command} within an isolated container. The current working
5785 directory outside the container is mapped inside the container.
5786 Additionally, unless overridden with @option{--user}, a dummy home
5787 directory is created that matches the current user's home directory, and
5788 @file{/etc/passwd} is configured accordingly.
5790 The spawned process runs as the current user outside the container. Inside
5791 the container, it has the same UID and GID as the current user, unless
5792 @option{--user} is passed (see below).
5796 For containers, share the network namespace with the host system.
5797 Containers created without this flag only have access to the loopback
5800 @item --link-profile
5802 For containers, link the environment profile to @file{~/.guix-profile}
5803 within the container and set @code{GUIX_ENVIRONMENT} to that.
5804 This is equivalent to making @file{~/.guix-profile} a symlink to the
5805 actual profile within the container.
5806 Linking will fail and abort the environment if the directory already
5807 exists, which will certainly be the case if @command{guix environment}
5808 was invoked in the user's home directory.
5810 Certain packages are configured to look in @file{~/.guix-profile} for
5811 configuration files and data;@footnote{For example, the
5812 @code{fontconfig} package inspects @file{~/.guix-profile/share/fonts}
5813 for additional fonts.} @option{--link-profile} allows these programs to
5814 behave as expected within the environment.
5816 @item --user=@var{user}
5817 @itemx -u @var{user}
5818 For containers, use the username @var{user} in place of the current
5819 user. The generated @file{/etc/passwd} entry within the container will
5820 contain the name @var{user}, the home directory will be
5821 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
5822 the UID and GID inside the container are 1000. @var{user}
5823 need not exist on the system.
5825 Additionally, any shared or exposed path (see @option{--share} and
5826 @option{--expose} respectively) whose target is within the current user's
5827 home directory will be remapped relative to @file{/home/USER}; this
5828 includes the automatic mapping of the current working directory.
5831 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
5833 guix environment --container --user=foo \
5834 --expose=$HOME/test \
5835 --expose=/tmp/target=$HOME/target
5838 While this will limit the leaking of user identity through home paths
5839 and each of the user fields, this is only one useful component of a
5840 broader privacy/anonymity solution---not one in and of itself.
5843 For containers, the default behavior is to share the current working
5844 directory with the isolated container and immediately change to that
5845 directory within the container. If this is undesirable,
5846 @option{--no-cwd} will cause the current working directory to @emph{not}
5847 be automatically shared and will change to the user's home directory
5848 within the container instead. See also @option{--user}.
5850 @item --expose=@var{source}[=@var{target}]
5851 @itemx --share=@var{source}[=@var{target}]
5852 For containers, @option{--expose} (resp. @option{--share}) exposes the
5853 file system @var{source} from the host system as the read-only
5854 (resp. writable) file system @var{target} within the container. If
5855 @var{target} is not specified, @var{source} is used as the target mount
5856 point in the container.
5858 The example below spawns a Guile REPL in a container in which the user's
5859 home directory is accessible read-only via the @file{/exchange}
5863 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
5868 @command{guix environment}
5869 also supports all of the common build options that @command{guix
5870 build} supports (@pxref{Common Build Options}) as well as package
5871 transformation options (@pxref{Package Transformation Options}).
5873 @node Invoking guix pack
5874 @section Invoking @command{guix pack}
5876 Occasionally you want to pass software to people who are not (yet!)
5877 lucky enough to be using Guix. You'd tell them to run @command{guix
5878 package -i @var{something}}, but that's not possible in this case. This
5879 is where @command{guix pack} comes in.
5882 If you are looking for ways to exchange binaries among machines that
5883 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
5884 publish}, and @ref{Invoking guix archive}.
5889 @cindex application bundle
5890 @cindex software bundle
5891 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
5892 @dfn{software bundle}: it creates a tarball or some other archive
5893 containing the binaries of the software you're interested in, and all
5894 its dependencies. The resulting archive can be used on any machine that
5895 does not have Guix, and people can run the exact same binaries as those
5896 you have with Guix. The pack itself is created in a bit-reproducible
5897 fashion, so anyone can verify that it really contains the build results
5898 that you pretend to be shipping.
5900 For example, to create a bundle containing Guile, Emacs, Geiser, and all
5901 their dependencies, you can run:
5904 $ guix pack guile emacs geiser
5906 /gnu/store/@dots{}-pack.tar.gz
5909 The result here is a tarball containing a @file{/gnu/store} directory
5910 with all the relevant packages. The resulting tarball contains a
5911 @dfn{profile} with the three packages of interest; the profile is the
5912 same as would be created by @command{guix package -i}. It is this
5913 mechanism that is used to create Guix's own standalone binary tarball
5914 (@pxref{Binary Installation}).
5916 Users of this pack would have to run
5917 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
5918 find inconvenient. To work around it, you can create, say, a
5919 @file{/opt/gnu/bin} symlink to the profile:
5922 guix pack -S /opt/gnu/bin=bin guile emacs geiser
5926 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
5928 @cindex relocatable binaries, with @command{guix pack}
5929 What if the recipient of your pack does not have root privileges on
5930 their machine, and thus cannot unpack it in the root file system? In
5931 that case, you will want to use the @option{--relocatable} option (see
5932 below). This option produces @dfn{relocatable binaries}, meaning they
5933 they can be placed anywhere in the file system hierarchy: in the example
5934 above, users can unpack your tarball in their home directory and
5935 directly run @file{./opt/gnu/bin/guile}.
5937 @cindex Docker, build an image with guix pack
5938 Alternatively, you can produce a pack in the Docker image format using
5939 the following command:
5942 guix pack -f docker -S /bin=bin guile guile-readline
5946 The result is a tarball that can be passed to the @command{docker load}
5947 command, followed by @code{docker run}:
5950 docker load < @var{file}
5951 docker run -ti guile-guile-readline /bin/guile
5955 where @var{file} is the image returned by @var{guix pack}, and
5956 @code{guile-guile-readline} is its ``image tag''. See the
5957 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5958 documentation} for more information.
5960 @cindex Singularity, build an image with guix pack
5961 @cindex SquashFS, build an image with guix pack
5962 Yet another option is to produce a SquashFS image with the following
5966 guix pack -f squashfs bash guile emacs geiser
5970 The result is a SquashFS file system image that can either be mounted or
5971 directly be used as a file system container image with the
5972 @uref{https://www.sylabs.io/docs/, Singularity container execution
5973 environment}, using commands like @command{singularity shell} or
5974 @command{singularity exec}.
5976 Several command-line options allow you to customize your pack:
5979 @item --format=@var{format}
5980 @itemx -f @var{format}
5981 Produce a pack in the given @var{format}.
5983 The available formats are:
5987 This is the default format. It produces a tarball containing all the
5988 specified binaries and symlinks.
5991 This produces a tarball that follows the
5992 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
5993 Docker Image Specification}. The ``repository name'' as it appears in
5994 the output of the @command{docker images} command is computed from
5995 package names passed on the command line or in the manifest file.
5998 This produces a SquashFS image containing all the specified binaries and
5999 symlinks, as well as empty mount points for virtual file systems like
6003 Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
6004 For that reason, @command{guix pack -f squashfs} always implies @code{-S
6005 /bin=bin}. Thus, your @command{guix pack} invocation must always start
6006 with something like:
6009 guix pack -f squashfs bash @dots{}
6012 If you forget the @code{bash} (or similar) package, @command{singularity
6013 run} and @command{singularity exec} will fail with an unhelpful ``no
6014 such file or directory'' message.
6018 @cindex relocatable binaries
6021 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
6022 anywhere in the file system hierarchy and run from there.
6024 When this option is passed once, the resulting binaries require support for
6025 @dfn{user namespaces} in the kernel Linux; when passed
6026 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
6027 PRoot support, can be thought of as the abbreviation of ``Really
6028 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to
6029 other techniques if user namespaces are unavailable, and essentially
6030 work anywhere---see below for the implications.
6032 For example, if you create a pack containing Bash with:
6035 guix pack -RR -S /mybin=bin bash
6039 ...@: you can copy that pack to a machine that lacks Guix, and from your
6040 home directory as a normal user, run:
6048 In that shell, if you type @code{ls /gnu/store}, you'll notice that
6049 @file{/gnu/store} shows up and contains all the dependencies of
6050 @code{bash}, even though the machine actually lacks @file{/gnu/store}
6051 altogether! That is probably the simplest way to deploy Guix-built
6052 software on a non-Guix machine.
6055 By default, relocatable binaries rely on the @dfn{user namespace} feature of
6056 the kernel Linux, which allows unprivileged users to mount or change root.
6057 Old versions of Linux did not support it, and some GNU/Linux distributions
6060 To produce relocatable binaries that work even in the absence of user
6061 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
6062 case, binaries will try user namespace support and fall back to another
6063 @dfn{execution engine} if user namespaces are not supported. The
6064 following execution engines are supported:
6068 Try user namespaces and fall back to PRoot if user namespaces are not
6069 supported (see below).
6072 Try user namespaces and fall back to Fakechroot if user namespaces are
6073 not supported (see below).
6076 Run the program through user namespaces and abort if they are not
6080 Run through PRoot. The @uref{https://proot-me.github.io/, PRoot} program
6081 provides the necessary
6082 support for file system virtualization. It achieves that by using the
6083 @code{ptrace} system call on the running program. This approach has the
6084 advantage to work without requiring special kernel support, but it incurs
6085 run-time overhead every time a system call is made.
6088 Run through Fakechroot. @uref{https://github.com/dex4er/fakechroot/,
6089 Fakechroot} virtualizes file system accesses by intercepting calls to C
6090 library functions such as @code{open}, @code{stat}, @code{exec}, and so
6091 on. Unlike PRoot, it incurs very little overhead. However, it does not
6092 always work: for example, some file system accesses made from within the
6093 C library are not intercepted, and file system accesses made @i{via}
6094 direct syscalls are not intercepted either, leading to erratic behavior.
6097 @vindex GUIX_EXECUTION_ENGINE
6098 When running a wrapped program, you can explicitly request one of the
6099 execution engines listed above by setting the
6100 @env{GUIX_EXECUTION_ENGINE} environment variable accordingly.
6103 @cindex entry point, for Docker images
6104 @item --entry-point=@var{command}
6105 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
6106 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
6107 support it. @var{command} must be relative to the profile contained in the
6110 The entry point specifies the command that tools like @code{docker run} or
6111 @code{singularity run} automatically start by default. For example, you can
6115 guix pack -f docker --entry-point=bin/guile guile
6118 The resulting pack can easily be loaded and @code{docker run} with no extra
6119 arguments will spawn @code{bin/guile}:
6122 docker load -i pack.tar.gz
6123 docker run @var{image-id}
6126 @item --expression=@var{expr}
6127 @itemx -e @var{expr}
6128 Consider the package @var{expr} evaluates to.
6130 This has the same purpose as the same-named option in @command{guix
6131 build} (@pxref{Additional Build Options, @option{--expression} in
6132 @command{guix build}}).
6134 @item --manifest=@var{file}
6135 @itemx -m @var{file}
6136 Use the packages contained in the manifest object returned by the Scheme
6137 code in @var{file}. This option can be repeated several times, in which
6138 case the manifests are concatenated.
6140 This has a similar purpose as the same-named option in @command{guix
6141 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
6142 same manifest files. It allows you to define a collection of packages
6143 once and use it both for creating profiles and for creating archives
6144 for use on machines that do not have Guix installed. Note that you can
6145 specify @emph{either} a manifest file @emph{or} a list of packages,
6148 @item --system=@var{system}
6149 @itemx -s @var{system}
6150 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
6151 the system type of the build host.
6153 @item --target=@var{triplet}
6154 @cindex cross-compilation
6155 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
6156 as @code{"aarch64-linux-gnu"} (@pxref{Specifying target triplets, GNU
6157 configuration triplets,, autoconf, Autoconf}).
6159 @item --compression=@var{tool}
6160 @itemx -C @var{tool}
6161 Compress the resulting tarball using @var{tool}---one of @code{gzip},
6162 @code{zstd}, @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no
6165 @item --symlink=@var{spec}
6166 @itemx -S @var{spec}
6167 Add the symlinks specified by @var{spec} to the pack. This option can
6168 appear several times.
6170 @var{spec} has the form @code{@var{source}=@var{target}}, where
6171 @var{source} is the symlink that will be created and @var{target} is the
6174 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
6175 symlink pointing to the @file{bin} sub-directory of the profile.
6177 @item --save-provenance
6178 Save provenance information for the packages passed on the command line.
6179 Provenance information includes the URL and commit of the channels in use
6182 Provenance information is saved in the
6183 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
6184 usual package metadata---the name and version of each package, their
6185 propagated inputs, and so on. It is useful information to the recipient of
6186 the pack, who then knows how the pack was (supposedly) obtained.
6188 This option is not enabled by default because, like timestamps, provenance
6189 information contributes nothing to the build process. In other words, there
6190 is an infinity of channel URLs and commit IDs that can lead to the same pack.
6191 Recording such ``silent'' metadata in the output thus potentially breaks the
6192 source-to-binary bitwise reproducibility property.
6194 @item --root=@var{file}
6195 @itemx -r @var{file}
6196 @cindex garbage collector root, for packs
6197 Make @var{file} a symlink to the resulting pack, and register it as a garbage
6200 @item --localstatedir
6201 @itemx --profile-name=@var{name}
6202 Include the ``local state directory'', @file{/var/guix}, in the resulting
6203 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
6204 profile---by default @var{name} is @code{guix-profile}, which corresponds to
6205 @file{~root/.guix-profile}.
6207 @file{/var/guix} contains the store database (@pxref{The Store}) as well
6208 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
6209 the pack means that the store is ``complete'' and manageable by Guix;
6210 not providing it pack means that the store is ``dead'': items cannot be
6211 added to it or removed from it after extraction of the pack.
6213 One use case for this is the Guix self-contained binary tarball
6214 (@pxref{Binary Installation}).
6218 Print the name of the derivation that builds the pack.
6221 Use the bootstrap binaries to build the pack. This option is only
6222 useful to Guix developers.
6225 In addition, @command{guix pack} supports all the common build options
6226 (@pxref{Common Build Options}) and all the package transformation
6227 options (@pxref{Package Transformation Options}).
6230 @node The GCC toolchain
6231 @section The GCC toolchain
6235 @cindex linker wrapper
6236 @cindex toolchain, for C development
6237 @cindex toolchain, for Fortran development
6239 If you need a complete toolchain for compiling and linking C or C++
6240 source code, use the @code{gcc-toolchain} package. This package
6241 provides a complete GCC toolchain for C/C++ development, including GCC
6242 itself, the GNU C Library (headers and binaries, plus debugging symbols
6243 in the @code{debug} output), Binutils, and a linker wrapper.
6245 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
6246 passed to the linker, add corresponding @code{-rpath} arguments, and
6247 invoke the actual linker with this new set of arguments. You can instruct the
6248 wrapper to refuse to link against libraries not in the store by setting the
6249 @env{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
6251 The package @code{gfortran-toolchain} provides a complete GCC toolchain
6252 for Fortran development. For other languages, please use
6253 @samp{guix search gcc toolchain} (@pxref{guix-search,, Invoking guix package}).
6256 @node Invoking guix git authenticate
6257 @section Invoking @command{guix git authenticate}
6259 The @command{guix git authenticate} command authenticates a Git checkout
6260 following the same rule as for channels (@pxref{channel-authentication,
6261 channel authentication}). That is, starting from a given commit, it
6262 ensures that all subsequent commits are signed by an OpenPGP key whose
6263 fingerprint appears in the @file{.guix-authorizations} file of its
6266 You will find this command useful if you maintain a channel. But in
6267 fact, this authentication mechanism is useful in a broader context, so
6268 you might want to use it for Git repositories that have nothing to do
6271 The general syntax is:
6274 guix git authenticate @var{commit} @var{signer} [@var{options}@dots{}]
6277 By default, this command authenticates the Git checkout in the current
6278 directory; it outputs nothing and exits with exit code zero on success
6279 and non-zero on failure. @var{commit} above denotes the first commit
6280 where authentication takes place, and @var{signer} is the OpenPGP
6281 fingerprint of public key used to sign @var{commit}. Together, they
6282 form a ``channel introduction'' (@pxref{channel-authentication, channel
6283 introduction}). The options below allow you to fine-tune the process.
6286 @item --repository=@var{directory}
6287 @itemx -r @var{directory}
6288 Open the Git repository in @var{directory} instead of the current
6291 @item --keyring=@var{reference}
6292 @itemx -k @var{reference}
6293 Load OpenPGP keyring from @var{reference}, the reference of a branch
6294 such as @code{origin/keyring} or @code{my-keyring}. The branch must
6295 contain OpenPGP public keys in @file{.key} files, either in binary form
6296 or ``ASCII-armored''. By default the keyring is loaded from the branch
6297 named @code{keyring}.
6300 Display commit signing statistics upon completion.
6302 @item --cache-key=@var{key}
6303 Previously-authenticated commits are cached in a file under
6304 @file{~/.cache/guix/authentication}. This option forces the cache to be
6305 stored in file @var{key} in that directory.
6307 @item --historical-authorizations=@var{file}
6308 By default, any commit whose parent commit(s) lack the
6309 @file{.guix-authorizations} file is considered inauthentic. In
6310 contrast, this option considers the authorizations in @var{file} for any
6311 commit that lacks @file{.guix-authorizations}. The format of @var{file}
6312 is the same as that of @file{.guix-authorizations}
6313 (@pxref{channel-authorizations, @file{.guix-authorizations} format}).
6317 @c *********************************************************************
6318 @node Programming Interface
6319 @chapter Programming Interface
6321 GNU Guix provides several Scheme programming interfaces (APIs) to
6322 define, build, and query packages. The first interface allows users to
6323 write high-level package definitions. These definitions refer to
6324 familiar packaging concepts, such as the name and version of a package,
6325 its build system, and its dependencies. These definitions can then be
6326 turned into concrete build actions.
6328 Build actions are performed by the Guix daemon, on behalf of users. In a
6329 standard setup, the daemon has write access to the store---the
6330 @file{/gnu/store} directory---whereas users do not. The recommended
6331 setup also has the daemon perform builds in chroots, under specific
6332 build users, to minimize interference with the rest of the system.
6335 Lower-level APIs are available to interact with the daemon and the
6336 store. To instruct the daemon to perform a build action, users actually
6337 provide it with a @dfn{derivation}. A derivation is a low-level
6338 representation of the build actions to be taken, and the environment in
6339 which they should occur---derivations are to package definitions what
6340 assembly is to C programs. The term ``derivation'' comes from the fact
6341 that build results @emph{derive} from them.
6343 This chapter describes all these APIs in turn, starting from high-level
6344 package definitions.
6347 * Package Modules:: Packages from the programmer's viewpoint.
6348 * Defining Packages:: Defining new packages.
6349 * Defining Package Variants:: Customizing packages.
6350 * Build Systems:: Specifying how packages are built.
6351 * Build Phases:: Phases of the build process of a package.
6352 * Build Utilities:: Helpers for your package definitions and more.
6353 * The Store:: Manipulating the package store.
6354 * Derivations:: Low-level interface to package derivations.
6355 * The Store Monad:: Purely functional interface to the store.
6356 * G-Expressions:: Manipulating build expressions.
6357 * Invoking guix repl:: Programming Guix in Guile
6360 @node Package Modules
6361 @section Package Modules
6363 From a programming viewpoint, the package definitions of the
6364 GNU distribution are provided by Guile modules in the @code{(gnu packages
6365 @dots{})} name space@footnote{Note that packages under the @code{(gnu
6366 packages @dots{})} module name space are not necessarily ``GNU
6367 packages''. This module naming scheme follows the usual Guile module
6368 naming convention: @code{gnu} means that these modules are distributed
6369 as part of the GNU system, and @code{packages} identifies modules that
6370 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
6371 Reference Manual}). For instance, the @code{(gnu packages emacs)}
6372 module exports a variable named @code{emacs}, which is bound to a
6373 @code{<package>} object (@pxref{Defining Packages}).
6375 The @code{(gnu packages @dots{})} module name space is
6376 automatically scanned for packages by the command-line tools. For
6377 instance, when running @code{guix install emacs}, all the @code{(gnu
6378 packages @dots{})} modules are scanned until one that exports a package
6379 object whose name is @code{emacs} is found. This package search
6380 facility is implemented in the @code{(gnu packages)} module.
6382 @cindex customization, of packages
6383 @cindex package module search path
6384 Users can store package definitions in modules with different
6385 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
6386 name and module name must match. For instance, the @code{(my-packages
6387 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
6388 relative to the load path specified with @option{--load-path} or
6389 @env{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
6390 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
6391 these package definitions visible to the user interfaces:
6395 By adding the directory containing your package modules to the search path
6396 with the @code{-L} flag of @command{guix package} and other commands
6397 (@pxref{Common Build Options}), or by setting the @env{GUIX_PACKAGE_PATH}
6398 environment variable described below.
6401 By defining a @dfn{channel} and configuring @command{guix pull} so that it
6402 pulls from it. A channel is essentially a Git repository containing package
6403 modules. @xref{Channels}, for more information on how to define and use
6407 @env{GUIX_PACKAGE_PATH} works similarly to other search path variables:
6409 @defvr {Environment Variable} GUIX_PACKAGE_PATH
6410 This is a colon-separated list of directories to search for additional
6411 package modules. Directories listed in this variable take precedence
6412 over the own modules of the distribution.
6415 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
6416 each package is built based solely on other packages in the
6417 distribution. The root of this dependency graph is a small set of
6418 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
6419 bootstrap)} module. For more information on bootstrapping,
6420 @pxref{Bootstrapping}.
6422 @node Defining Packages
6423 @section Defining Packages
6425 The high-level interface to package definitions is implemented in the
6426 @code{(guix packages)} and @code{(guix build-system)} modules. As an
6427 example, the package definition, or @dfn{recipe}, for the GNU Hello
6428 package looks like this:
6431 (define-module (gnu packages hello)
6432 #:use-module (guix packages)
6433 #:use-module (guix download)
6434 #:use-module (guix build-system gnu)
6435 #:use-module (guix licenses)
6436 #:use-module (gnu packages gawk))
6438 (define-public hello
6444 (uri (string-append "mirror://gnu/hello/hello-" version
6448 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
6449 (build-system gnu-build-system)
6450 (arguments '(#:configure-flags '("--enable-silent-rules")))
6451 (inputs `(("gawk" ,gawk)))
6452 (synopsis "Hello, GNU world: An example GNU package")
6453 (description "Guess what GNU Hello prints!")
6454 (home-page "https://www.gnu.org/software/hello/")
6459 Without being a Scheme expert, the reader may have guessed the meaning
6460 of the various fields here. This expression binds the variable
6461 @code{hello} to a @code{<package>} object, which is essentially a record
6462 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
6463 This package object can be inspected using procedures found in the
6464 @code{(guix packages)} module; for instance, @code{(package-name hello)}
6465 returns---surprise!---@code{"hello"}.
6467 With luck, you may be able to import part or all of the definition of
6468 the package you are interested in from another repository, using the
6469 @code{guix import} command (@pxref{Invoking guix import}).
6471 In the example above, @code{hello} is defined in a module of its own,
6472 @code{(gnu packages hello)}. Technically, this is not strictly
6473 necessary, but it is convenient to do so: all the packages defined in
6474 modules under @code{(gnu packages @dots{})} are automatically known to
6475 the command-line tools (@pxref{Package Modules}).
6477 There are a few points worth noting in the above package definition:
6481 The @code{source} field of the package is an @code{<origin>} object
6482 (@pxref{origin Reference}, for the complete reference).
6483 Here, the @code{url-fetch} method from @code{(guix download)} is used,
6484 meaning that the source is a file to be downloaded over FTP or HTTP.
6486 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
6487 the GNU mirrors defined in @code{(guix download)}.
6489 The @code{sha256} field specifies the expected SHA256 hash of the file
6490 being downloaded. It is mandatory, and allows Guix to check the
6491 integrity of the file. The @code{(base32 @dots{})} form introduces the
6492 base32 representation of the hash. You can obtain this information with
6493 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
6494 hash} (@pxref{Invoking guix hash}).
6497 When needed, the @code{origin} form can also have a @code{patches} field
6498 listing patches to be applied, and a @code{snippet} field giving a
6499 Scheme expression to modify the source code.
6502 @cindex GNU Build System
6503 The @code{build-system} field specifies the procedure to build the
6504 package (@pxref{Build Systems}). Here, @code{gnu-build-system}
6505 represents the familiar GNU Build System, where packages may be
6506 configured, built, and installed with the usual @code{./configure &&
6507 make && make check && make install} command sequence.
6509 When you start packaging non-trivial software, you may need tools to
6510 manipulate those build phases, manipulate files, and so on. @xref{Build
6511 Utilities}, for more on this.
6514 The @code{arguments} field specifies options for the build system
6515 (@pxref{Build Systems}). Here it is interpreted by
6516 @code{gnu-build-system} as a request run @file{configure} with the
6517 @option{--enable-silent-rules} flag.
6523 What about these quote (@code{'}) characters? They are Scheme syntax to
6524 introduce a literal list; @code{'} is synonymous with @code{quote}.
6525 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
6526 for details. Here the value of the @code{arguments} field is a list of
6527 arguments passed to the build system down the road, as with @code{apply}
6528 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
6531 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
6532 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
6533 @code{#:configure-flags} is a keyword used to pass a keyword argument
6534 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
6538 The @code{inputs} field specifies inputs to the build process---i.e.,
6539 build-time or run-time dependencies of the package. Here, we define an
6540 input called @code{"gawk"} whose value is that of the @code{gawk}
6541 variable; @code{gawk} is itself bound to a @code{<package>} object.
6543 @cindex backquote (quasiquote)
6546 @cindex comma (unquote)
6550 @findex unquote-splicing
6551 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
6552 us to introduce a literal list in the @code{inputs} field, while
6553 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
6554 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
6557 Note that GCC, Coreutils, Bash, and other essential tools do not need to
6558 be specified as inputs here. Instead, @code{gnu-build-system} takes care
6559 of ensuring that they are present (@pxref{Build Systems}).
6561 However, any other dependencies need to be specified in the
6562 @code{inputs} field. Any dependency not specified here will simply be
6563 unavailable to the build process, possibly leading to a build failure.
6566 @xref{package Reference}, for a full description of possible fields.
6568 Once a package definition is in place, the
6569 package may actually be built using the @code{guix build} command-line
6570 tool (@pxref{Invoking guix build}), troubleshooting any build failures
6571 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
6572 package definition using the @command{guix edit} command
6573 (@pxref{Invoking guix edit}).
6574 @xref{Packaging Guidelines}, for
6575 more information on how to test package definitions, and
6576 @ref{Invoking guix lint}, for information on how to check a definition
6577 for style conformance.
6578 @vindex GUIX_PACKAGE_PATH
6579 Lastly, @pxref{Channels}, for information
6580 on how to extend the distribution by adding your own package definitions
6583 Finally, updating the package definition to a new upstream version
6584 can be partly automated by the @command{guix refresh} command
6585 (@pxref{Invoking guix refresh}).
6587 Behind the scenes, a derivation corresponding to the @code{<package>}
6588 object is first computed by the @code{package-derivation} procedure.
6589 That derivation is stored in a @file{.drv} file under @file{/gnu/store}.
6590 The build actions it prescribes may then be realized by using the
6591 @code{build-derivations} procedure (@pxref{The Store}).
6593 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
6594 Return the @code{<derivation>} object of @var{package} for @var{system}
6595 (@pxref{Derivations}).
6597 @var{package} must be a valid @code{<package>} object, and @var{system}
6598 must be a string denoting the target system type---e.g.,
6599 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
6600 must be a connection to the daemon, which operates on the store
6601 (@pxref{The Store}).
6605 @cindex cross-compilation
6606 Similarly, it is possible to compute a derivation that cross-builds a
6607 package for some other system:
6609 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
6610 @var{package} @var{target} [@var{system}]
6611 Return the @code{<derivation>} object of @var{package} cross-built from
6612 @var{system} to @var{target}.
6614 @var{target} must be a valid GNU triplet denoting the target hardware
6615 and operating system, such as @code{"aarch64-linux-gnu"}
6616 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
6619 Once you have package definitions, you can easily define @emph{variants}
6620 of those packages. @xref{Defining Package Variants}, for more on that.
6623 * package Reference:: The package data type.
6624 * origin Reference:: The origin data type.
6628 @node package Reference
6629 @subsection @code{package} Reference
6631 This section summarizes all the options available in @code{package}
6632 declarations (@pxref{Defining Packages}).
6634 @deftp {Data Type} package
6635 This is the data type representing a package recipe.
6639 The name of the package, as a string.
6641 @item @code{version}
6642 The version of the package, as a string.
6645 An object telling how the source code for the package should be
6646 acquired. Most of the time, this is an @code{origin} object, which
6647 denotes a file fetched from the Internet (@pxref{origin Reference}). It
6648 can also be any other ``file-like'' object such as a @code{local-file},
6649 which denotes a file from the local file system (@pxref{G-Expressions,
6650 @code{local-file}}).
6652 @item @code{build-system}
6653 The build system that should be used to build the package (@pxref{Build
6656 @item @code{arguments} (default: @code{'()})
6657 The arguments that should be passed to the build system. This is a
6658 list, typically containing sequential keyword-value pairs.
6660 @item @code{inputs} (default: @code{'()})
6661 @itemx @code{native-inputs} (default: @code{'()})
6662 @itemx @code{propagated-inputs} (default: @code{'()})
6663 @cindex inputs, of packages
6664 These fields list dependencies of the package. Each one is a list of
6665 tuples, where each tuple has a label for the input (a string) as its
6666 first element, a package, origin, or derivation as its second element,
6667 and optionally the name of the output thereof that should be used, which
6668 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
6669 more on package outputs). For example, the list below specifies three
6673 `(("libffi" ,libffi)
6674 ("libunistring" ,libunistring)
6675 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
6678 @cindex cross compilation, package dependencies
6679 The distinction between @code{native-inputs} and @code{inputs} is
6680 necessary when considering cross-compilation. When cross-compiling,
6681 dependencies listed in @code{inputs} are built for the @emph{target}
6682 architecture; conversely, dependencies listed in @code{native-inputs}
6683 are built for the architecture of the @emph{build} machine.
6685 @code{native-inputs} is typically used to list tools needed at
6686 build time, but not at run time, such as Autoconf, Automake, pkg-config,
6687 Gettext, or Bison. @command{guix lint} can report likely mistakes in
6688 this area (@pxref{Invoking guix lint}).
6690 @anchor{package-propagated-inputs}
6691 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
6692 specified packages will be automatically installed to profiles
6693 (@pxref{Features, the role of profiles in Guix}) alongside the package
6694 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
6695 package}}, for information on how @command{guix package} deals with
6698 For example this is necessary when packaging a C/C++ library that needs
6699 headers of another library to compile, or when a pkg-config file refers
6700 to another one @i{via} its @code{Requires} field.
6702 Another example where @code{propagated-inputs} is useful is for languages
6703 that lack a facility to record the run-time search path akin to the
6704 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
6705 more. When packaging libraries written in those languages, ensure they
6706 can find library code they depend on at run time by listing run-time
6707 dependencies in @code{propagated-inputs} rather than @code{inputs}.
6709 @item @code{outputs} (default: @code{'("out")})
6710 The list of output names of the package. @xref{Packages with Multiple
6711 Outputs}, for typical uses of additional outputs.
6713 @item @code{native-search-paths} (default: @code{'()})
6714 @itemx @code{search-paths} (default: @code{'()})
6715 A list of @code{search-path-specification} objects describing
6716 search-path environment variables honored by the package.
6718 @item @code{replacement} (default: @code{#f})
6719 This must be either @code{#f} or a package object that will be used as a
6720 @dfn{replacement} for this package. @xref{Security Updates, grafts},
6723 @item @code{synopsis}
6724 A one-line description of the package.
6726 @item @code{description}
6727 A more elaborate description of the package.
6729 @item @code{license}
6730 @cindex license, of packages
6731 The license of the package; a value from @code{(guix licenses)},
6732 or a list of such values.
6734 @item @code{home-page}
6735 The URL to the home-page of the package, as a string.
6737 @item @code{supported-systems} (default: @code{%supported-systems})
6738 The list of systems supported by the package, as strings of the form
6739 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
6741 @item @code{location} (default: source location of the @code{package} form)
6742 The source location of the package. It is useful to override this when
6743 inheriting from another package, in which case this field is not
6744 automatically corrected.
6748 @deffn {Scheme Syntax} this-package
6749 When used in the @emph{lexical scope} of a package field definition, this
6750 identifier resolves to the package being defined.
6752 The example below shows how to add a package as a native input of itself when
6760 ;; When cross-compiled, Guile, for example, depends on
6761 ;; a native version of itself. Add it here.
6762 (native-inputs (if (%current-target-system)
6763 `(("self" ,this-package))
6767 It is an error to refer to @code{this-package} outside a package definition.
6770 Because packages are regular Scheme objects that capture a complete
6771 dependency graph and associated build procedures, it is often useful to
6772 write procedures that take a package and return a modified version
6773 thereof according to some parameters. Below are a few examples.
6775 @cindex tool chain, choosing a package's tool chain
6776 @deffn {Scheme Procedure} package-with-c-toolchain @var{package} @var{toolchain}
6777 Return a variant of @var{package} that uses @var{toolchain} instead of
6778 the default GNU C/C++ toolchain. @var{toolchain} must be a list of
6779 inputs (label/package tuples) providing equivalent functionality, such
6780 as the @code{gcc-toolchain} package.
6782 The example below returns a variant of the @code{hello} package built
6783 with GCC@tie{}10.x and the rest of the GNU tool chain (Binutils and the
6784 GNU C Library) instead of the default tool chain:
6787 (let ((toolchain (specification->package "gcc-toolchain@@10")))
6788 (package-with-c-toolchain hello `(("toolchain" ,toolchain))))
6791 The build tool chain is part of the @dfn{implicit inputs} of
6792 packages---it's usually not listed as part of the various ``inputs''
6793 fields and is instead pulled in by the build system. Consequently, this
6794 procedure works by changing the build system of @var{package} so that it
6795 pulls in @var{toolchain} instead of the defaults. @ref{Build Systems},
6796 for more on build systems.
6799 @node origin Reference
6800 @subsection @code{origin} Reference
6802 This section documents @dfn{origins}. An @code{origin} declaration
6803 specifies data that must be ``produced''---downloaded, usually---and
6804 whose content hash is known in advance. Origins are primarily used to
6805 represent the source code of packages (@pxref{Defining Packages}). For
6806 that reason, the @code{origin} form allows you to declare patches to
6807 apply to the original source code as well as code snippets to modify it.
6809 @deftp {Data Type} origin
6810 This is the data type representing a source code origin.
6814 An object containing the URI of the source. The object type depends on
6815 the @code{method} (see below). For example, when using the
6816 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
6817 values are: a URL represented as a string, or a list thereof.
6819 @cindex fixed-output derivations, for download
6821 A monadic procedure that handles the given URI@. The procedure must
6822 accept at least three arguments: the value of the @code{uri} field and
6823 the hash algorithm and hash value specified by the @code{hash} field.
6824 It must return a store item or a derivation in the store monad
6825 (@pxref{The Store Monad}); most methods return a fixed-output derivation
6826 (@pxref{Derivations}).
6828 Commonly used methods include @code{url-fetch}, which fetches data from
6829 a URL, and @code{git-fetch}, which fetches data from a Git repository
6833 A bytevector containing the SHA-256 hash of the source. This is
6834 equivalent to providing a @code{content-hash} SHA256 object in the
6835 @code{hash} field described below.
6838 The @code{content-hash} object of the source---see below for how to use
6839 @code{content-hash}.
6841 You can obtain this information using @code{guix download}
6842 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
6845 @item @code{file-name} (default: @code{#f})
6846 The file name under which the source code should be saved. When this is
6847 @code{#f}, a sensible default value will be used in most cases. In case
6848 the source is fetched from a URL, the file name from the URL will be
6849 used. For version control checkouts, it is recommended to provide the
6850 file name explicitly because the default is not very descriptive.
6852 @item @code{patches} (default: @code{'()})
6853 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
6854 file-like objects}) pointing to patches to be applied to the source.
6856 This list of patches must be unconditional. In particular, it cannot
6857 depend on the value of @code{%current-system} or
6858 @code{%current-target-system}.
6860 @item @code{snippet} (default: @code{#f})
6861 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
6862 in the source directory. This is a convenient way to modify the source,
6863 sometimes more convenient than a patch.
6865 @item @code{patch-flags} (default: @code{'("-p1")})
6866 A list of command-line flags that should be passed to the @code{patch}
6869 @item @code{patch-inputs} (default: @code{#f})
6870 Input packages or derivations to the patching process. When this is
6871 @code{#f}, the usual set of inputs necessary for patching are provided,
6872 such as GNU@tie{}Patch.
6874 @item @code{modules} (default: @code{'()})
6875 A list of Guile modules that should be loaded during the patching
6876 process and while running the code in the @code{snippet} field.
6878 @item @code{patch-guile} (default: @code{#f})
6879 The Guile package that should be used in the patching process. When
6880 this is @code{#f}, a sensible default is used.
6884 @deftp {Data Type} content-hash @var{value} [@var{algorithm}]
6885 Construct a content hash object for the given @var{algorithm}, and with
6886 @var{value} as its hash value. When @var{algorithm} is omitted, assume
6887 it is @code{sha256}.
6889 @var{value} can be a literal string, in which case it is base32-decoded,
6890 or it can be a bytevector.
6892 The following forms are all equivalent:
6895 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj")
6896 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"
6898 (content-hash (base32
6899 "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"))
6900 (content-hash (base64 "kkb+RPaP7uyMZmu4eXPVkM4BN8yhRd8BTHLslb6f/Rc=")
6904 Technically, @code{content-hash} is currently implemented as a macro.
6905 It performs sanity checks at macro-expansion time, when possible, such
6906 as ensuring that @var{value} has the right size for @var{algorithm}.
6909 As we have seen above, how exactly the data an origin refers to is
6910 retrieved is determined by its @code{method} field. The @code{(guix
6911 download)} module provides the most common method, @code{url-fetch},
6914 @deffn {Scheme Procedure} url-fetch @var{url} @var{hash-algo} @var{hash} @
6915 [name] [#:executable? #f]
6916 Return a fixed-output derivation that fetches data from @var{url} (a
6917 string, or a list of strings denoting alternate URLs), which is expected
6918 to have hash @var{hash} of type @var{hash-algo} (a symbol). By default,
6919 the file name is the base name of URL; optionally, @var{name} can
6920 specify a different file name. When @var{executable?} is true, make the
6921 downloaded file executable.
6923 When one of the URL starts with @code{mirror://}, then its host part is
6924 interpreted as the name of a mirror scheme, taken from @file{%mirror-file}.
6926 Alternatively, when URL starts with @code{file://}, return the
6927 corresponding file name in the store.
6930 Likewise, the @code{(guix git-download)} module defines the
6931 @code{git-fetch} origin method, which fetches data from a Git version
6932 control repository, and the @code{git-reference} data type to describe
6933 the repository and revision to fetch.
6935 @deffn {Scheme Procedure} git-fetch @var{ref} @var{hash-algo} @var{hash}
6936 Return a fixed-output derivation that fetches @var{ref}, a
6937 @code{<git-reference>} object. The output is expected to have recursive
6938 hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
6939 the file name, or a generic name if @code{#f}.
6942 @deftp {Data Type} git-reference
6943 This data type represents a Git reference for @code{git-fetch} to
6948 The URL of the Git repository to clone.
6951 This string denotes either the commit to fetch (a hexadecimal string,
6952 either the full SHA1 commit or a ``short'' commit string; the latter is
6953 not recommended) or the tag to fetch.
6955 @item @code{recursive?} (default: @code{#f})
6956 This Boolean indicates whether to recursively fetch Git sub-modules.
6959 The example below denotes the @code{v2.10} tag of the GNU@tie{}Hello
6964 (url "https://git.savannah.gnu.org/git/hello.git")
6968 This is equivalent to the reference below, which explicitly names the
6973 (url "https://git.savannah.gnu.org/git/hello.git")
6974 (commit "dc7dc56a00e48fe6f231a58f6537139fe2908fb9"))
6978 For Mercurial repositories, the module @code{(guix hg-download)} defines
6979 the @code{hg-fetch} origin method and @code{hg-reference} data type for
6980 support of the Mercurial version control system.
6982 @deffn {Scheme Procedure} hg-fetch @var{ref} @var{hash-algo} @var{hash} @
6984 Return a fixed-output derivation that fetches @var{ref}, a
6985 @code{<hg-reference>} object. The output is expected to have recursive
6986 hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
6987 the file name, or a generic name if @code{#false}.
6990 @node Defining Package Variants
6991 @section Defining Package Variants
6993 @cindex customizing packages
6994 @cindex variants, of packages
6995 One of the nice things with Guix is that, given a package definition,
6996 you can easily @emph{derive} variants of that package---for a different
6997 upstream version, with different dependencies, different compilation
6998 options, and so on. Some of these custom packages can be defined
6999 straight from the command line (@pxref{Package Transformation Options}).
7000 This section describes how to define package variants in code. This can
7001 be useful in ``manifests'' (@pxref{profile-manifest,
7002 @option{--manifest}}) and in your own package collection
7003 (@pxref{Creating a Channel}), among others!
7005 @cindex inherit, for package definitions
7006 As discussed earlier, packages are first-class objects in the Scheme
7007 language. The @code{(guix packages)} module provides the @code{package}
7008 construct to define new package objects (@pxref{package Reference}).
7009 The easiest way to define a package variant is using the @code{inherit}
7010 keyword together with @code{package}. This allows you to inherit from a
7011 package definition while overriding the fields you want.
7013 For example, given the @code{hello} variable, which contains a
7014 definition for the current version of GNU@tie{}Hello, here's how you
7015 would define a variant for version 2.2 (released in 2006, it's
7019 (use-modules (gnu packages base)) ;for 'hello'
7027 (uri (string-append "mirror://gnu/hello/hello-" version
7031 "0lappv4slgb5spyqbh6yl5r013zv72yqg2pcl30mginf3wdqd8k9"))))))
7034 The example above corresponds to what the @option{--with-source} package
7035 transformation option does. Essentially @code{hello-2.2} preserves all
7036 the fields of @code{hello}, except @code{version} and @code{source},
7037 which it overrides. Note that the original @code{hello} variable is
7038 still there, in the @code{(gnu packages base)} module, unchanged. When
7039 you define a custom package like this, you are really @emph{adding} a
7040 new package definition; the original one remains available.
7042 You can just as well define variants with a different set of
7043 dependencies than the original package. For example, the default
7044 @code{gdb} package depends on @code{guile}, but since that is an
7045 optional dependency, you can define a variant that removes that
7049 (use-modules (gnu packages gdb) ;for 'gdb'
7050 (srfi srfi-1)) ;for 'alist-delete'
7052 (define gdb-sans-guile
7055 (inputs (alist-delete "guile"
7056 (package-inputs gdb)))))
7059 The @code{alist-delete} call above removes the tuple from the
7060 @code{inputs} field that has @code{"guile"} as its first element
7061 (@pxref{SRFI-1 Association Lists,,, guile, GNU Guile Reference
7064 In some cases, you may find it useful to write functions
7065 (``procedures'', in Scheme parlance) that return a package based on some
7066 parameters. For example, consider the @code{luasocket} library for the
7067 Lua programming language. We want to create @code{luasocket} packages
7068 for major versions of Lua. One way to do that is to define a procedure
7069 that takes a Lua package and returns a @code{luasocket} package that
7073 (define (make-lua-socket name lua)
7074 ;; Return a luasocket package built with LUA.
7078 ;; several fields omitted
7081 (synopsis "Socket library for Lua")))
7083 (define-public lua5.1-socket
7084 (make-lua-socket "lua5.1-socket" lua-5.1))
7086 (define-public lua5.2-socket
7087 (make-lua-socket "lua5.2-socket" lua-5.2))
7090 Here we have defined packages @code{lua5.1-socket} and
7091 @code{lua5.2-socket} by calling @code{make-lua-socket} with different
7092 arguments. @xref{Procedures,,, guile, GNU Guile Reference Manual}, for
7093 more info on procedures. Having top-level public definitions for these
7094 two packages means that they can be referred to from the command line
7095 (@pxref{Package Modules}).
7097 @cindex package transformations
7098 These are pretty simple package variants. As a convenience, the
7099 @code{(guix transformations)} module provides a high-level interface
7100 that directly maps to the more sophisticated package transformation
7101 options (@pxref{Package Transformation Options}):
7103 @deffn {Scheme Procedure} options->transformation @var{opts}
7104 Return a procedure that, when passed an object to build (package,
7105 derivation, etc.), applies the transformations specified by @var{opts} and returns
7106 the resulting objects. @var{opts} must be a list of symbol/string pairs such as:
7109 ((with-branch . "guile-gcrypt=master")
7110 (without-tests . "libgcrypt"))
7113 Each symbol names a transformation and the corresponding string is an argument
7114 to that transformation.
7117 For instance, a manifest equivalent to this command:
7121 --with-branch=guile-gcrypt=master \
7122 --with-debug-info=zlib
7126 ... would look like this:
7129 (use-modules (guix transformations))
7132 ;; The package transformation procedure.
7133 (options->transformation
7134 '((with-branch . "guile-gcrypt=master")
7135 (with-debug-info . "zlib"))))
7138 (list (transform (specification->package "guix"))))
7141 @cindex input rewriting
7142 @cindex dependency graph rewriting
7143 The @code{options->transformation} procedure is convenient, but it's
7144 perhaps also not as flexible as you may like. How is it implemented?
7145 The astute reader probably noticed that most package transformation
7146 options go beyond the superficial changes shown in the first examples of
7147 this section: they involve @dfn{input rewriting}, whereby the dependency
7148 graph of a package is rewritten by replacing specific inputs by others.
7150 Dependency graph rewriting, for the purposes of swapping packages in the
7151 graph, is what the @code{package-input-rewriting} procedure in
7152 @code{(guix packages)} implements.
7154 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
7155 [@var{rewrite-name}] [#:deep? #t]
7156 Return a procedure that, when passed a package, replaces its direct and
7157 indirect dependencies, including implicit inputs when @var{deep?} is
7158 true, according to @var{replacements}. @var{replacements} is a list of
7159 package pairs; the first element of each pair is the package to replace,
7160 and the second one is the replacement.
7162 Optionally, @var{rewrite-name} is a one-argument procedure that takes
7163 the name of a package and returns its new name after rewrite.
7167 Consider this example:
7170 (define libressl-instead-of-openssl
7171 ;; This is a procedure to replace OPENSSL by LIBRESSL,
7173 (package-input-rewriting `((,openssl . ,libressl))))
7175 (define git-with-libressl
7176 (libressl-instead-of-openssl git))
7180 Here we first define a rewriting procedure that replaces @var{openssl}
7181 with @var{libressl}. Then we use it to define a @dfn{variant} of the
7182 @var{git} package that uses @var{libressl} instead of @var{openssl}.
7183 This is exactly what the @option{--with-input} command-line option does
7184 (@pxref{Package Transformation Options, @option{--with-input}}).
7186 The following variant of @code{package-input-rewriting} can match packages to
7187 be replaced by name rather than by identity.
7189 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements} [#:deep? #t]
7190 Return a procedure that, given a package, applies the given
7191 @var{replacements} to all the package graph, including implicit inputs
7192 unless @var{deep?} is false. @var{replacements} is a list of
7193 spec/procedures pair; each spec is a package specification such as
7194 @code{"gcc"} or @code{"guile@@2"}, and each procedure takes a matching
7195 package and returns a replacement for that package.
7198 The example above could be rewritten this way:
7201 (define libressl-instead-of-openssl
7202 ;; Replace all the packages called "openssl" with LibreSSL.
7203 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
7206 The key difference here is that, this time, packages are matched by spec and
7207 not by identity. In other words, any package in the graph that is called
7208 @code{openssl} will be replaced.
7210 A more generic procedure to rewrite a package dependency graph is
7211 @code{package-mapping}: it supports arbitrary changes to nodes in the
7214 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}] [#:deep? #f]
7215 Return a procedure that, given a package, applies @var{proc} to all the packages
7216 depended on and returns the resulting package. The procedure stops recursion
7217 when @var{cut?} returns true for a given package. When @var{deep?} is true, @var{proc} is
7218 applied to implicit inputs as well.
7223 @section Build Systems
7225 @cindex build system
7226 Each package definition specifies a @dfn{build system} and arguments for
7227 that build system (@pxref{Defining Packages}). This @code{build-system}
7228 field represents the build procedure of the package, as well as implicit
7229 dependencies of that build procedure.
7231 Build systems are @code{<build-system>} objects. The interface to
7232 create and manipulate them is provided by the @code{(guix build-system)}
7233 module, and actual build systems are exported by specific modules.
7235 @cindex bag (low-level package representation)
7236 Under the hood, build systems first compile package objects to
7237 @dfn{bags}. A @dfn{bag} is like a package, but with less
7238 ornamentation---in other words, a bag is a lower-level representation of
7239 a package, which includes all the inputs of that package, including some
7240 that were implicitly added by the build system. This intermediate
7241 representation is then compiled to a derivation (@pxref{Derivations}).
7242 The @code{package-with-c-toolchain} is an example of a way to change the
7243 implicit inputs that a package's build system pulls in (@pxref{package
7244 Reference, @code{package-with-c-toolchain}}).
7246 Build systems accept an optional list of @dfn{arguments}. In package
7247 definitions, these are passed @i{via} the @code{arguments} field
7248 (@pxref{Defining Packages}). They are typically keyword arguments
7249 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
7250 Guile Reference Manual}). The value of these arguments is usually
7251 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
7252 by the daemon (@pxref{Derivations}).
7254 The main build system is @code{gnu-build-system}, which implements the
7255 standard build procedure for GNU and many other packages. It
7256 is provided by the @code{(guix build-system gnu)} module.
7258 @defvr {Scheme Variable} gnu-build-system
7259 @code{gnu-build-system} represents the GNU Build System, and variants
7260 thereof (@pxref{Configuration, configuration and makefile conventions,,
7261 standards, GNU Coding Standards}).
7263 @cindex build phases
7264 In a nutshell, packages using it are configured, built, and installed with
7265 the usual @code{./configure && make && make check && make install}
7266 command sequence. In practice, a few additional steps are often needed.
7267 All these steps are split up in separate @dfn{phases},
7268 notably@footnote{Please see the @code{(guix build gnu-build-system)}
7269 modules for more details about the build phases.}:
7273 Unpack the source tarball, and change the current directory to the
7274 extracted source tree. If the source is actually a directory, copy it
7275 to the build tree, and enter that directory.
7277 @item patch-source-shebangs
7278 Patch shebangs encountered in source files so they refer to the right
7279 store file names. For instance, this changes @code{#!/bin/sh} to
7280 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
7283 Run the @file{configure} script with a number of default options, such
7284 as @option{--prefix=/gnu/store/@dots{}}, as well as the options specified
7285 by the @code{#:configure-flags} argument.
7288 Run @code{make} with the list of flags specified with
7289 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
7290 (the default), build with @code{make -j}.
7293 Run @code{make check}, or some other target specified with
7294 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
7295 @code{#:parallel-tests?} argument is true (the default), run @code{make
7299 Run @code{make install} with the flags listed in @code{#:make-flags}.
7301 @item patch-shebangs
7302 Patch shebangs on the installed executable files.
7305 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
7306 is false), copying them to the @code{debug} output when available
7307 (@pxref{Installing Debugging Files}).
7310 @vindex %standard-phases
7311 The build-side module @code{(guix build gnu-build-system)} defines
7312 @code{%standard-phases} as the default list of build phases.
7313 @code{%standard-phases} is a list of symbol/procedure pairs, where the
7314 procedure implements the actual phase.
7316 @xref{Build Phases}, for more info on build phases and ways to customize
7319 In addition, this build system ensures that the ``standard'' environment
7320 for GNU packages is available. This includes tools such as GCC, libc,
7321 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
7322 build-system gnu)} module for a complete list). We call these the
7323 @dfn{implicit inputs} of a package, because package definitions do not
7324 have to mention them.
7327 Other @code{<build-system>} objects are defined to support other
7328 conventions and tools used by free software packages. They inherit most
7329 of @code{gnu-build-system}, and differ mainly in the set of inputs
7330 implicitly added to the build process, and in the list of phases
7331 executed. Some of these build systems are listed below.
7333 @defvr {Scheme Variable} ant-build-system
7334 This variable is exported by @code{(guix build-system ant)}. It
7335 implements the build procedure for Java packages that can be built with
7336 @url{https://ant.apache.org/, Ant build tool}.
7338 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
7339 provided by the @code{icedtea} package to the set of inputs. Different
7340 packages can be specified with the @code{#:ant} and @code{#:jdk}
7341 parameters, respectively.
7343 When the original package does not provide a suitable Ant build file,
7344 the parameter @code{#:jar-name} can be used to generate a minimal Ant
7345 build file @file{build.xml} with tasks to build the specified jar
7346 archive. In this case the parameter @code{#:source-dir} can be used to
7347 specify the source sub-directory, defaulting to ``src''.
7349 The @code{#:main-class} parameter can be used with the minimal ant
7350 buildfile to specify the main class of the resulting jar. This makes the
7351 jar file executable. The @code{#:test-include} parameter can be used to
7352 specify the list of junit tests to run. It defaults to
7353 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
7354 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
7355 because abstract classes cannot be run as tests.
7357 The parameter @code{#:build-target} can be used to specify the Ant task
7358 that should be run during the @code{build} phase. By default the
7359 ``jar'' task will be run.
7363 @defvr {Scheme Variable} android-ndk-build-system
7364 @cindex Android distribution
7365 @cindex Android NDK build system
7366 This variable is exported by @code{(guix build-system android-ndk)}. It
7367 implements a build procedure for Android NDK (native development kit)
7368 packages using a Guix-specific build process.
7370 The build system assumes that packages install their public interface
7371 (header) files to the subdirectory @file{include} of the @code{out} output and
7372 their libraries to the subdirectory @file{lib} the @code{out} output.
7374 It's also assumed that the union of all the dependencies of a package
7375 has no conflicting files.
7377 For the time being, cross-compilation is not supported - so right now
7378 the libraries and header files are assumed to be host tools.
7382 @defvr {Scheme Variable} asdf-build-system/source
7383 @defvrx {Scheme Variable} asdf-build-system/sbcl
7384 @defvrx {Scheme Variable} asdf-build-system/ecl
7386 These variables, exported by @code{(guix build-system asdf)}, implement
7387 build procedures for Common Lisp packages using
7388 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
7389 definition facility for Common Lisp programs and libraries.
7391 The @code{asdf-build-system/source} system installs the packages in
7392 source form, and can be loaded using any common lisp implementation, via
7393 ASDF@. The others, such as @code{asdf-build-system/sbcl}, install binary
7394 systems in the format which a particular implementation understands.
7395 These build systems can also be used to produce executable programs, or
7396 lisp images which contain a set of packages pre-loaded.
7398 The build system uses naming conventions. For binary packages, the
7399 package name should be prefixed with the lisp implementation, such as
7400 @code{sbcl-} for @code{asdf-build-system/sbcl}.
7402 Additionally, the corresponding source package should be labeled using
7403 the same convention as python packages (see @ref{Python Modules}), using
7404 the @code{cl-} prefix.
7406 In order to create executable programs and images, the build-side
7407 procedures @code{build-program} and @code{build-image} can be used.
7408 They should be called in a build phase after the
7409 @code{create-asdf-configuration} phase, so that the system which was
7410 just built can be used within the resulting image. @code{build-program}
7411 requires a list of Common Lisp expressions to be passed as the
7412 @code{#:entry-program} argument.
7414 By default, all the @file{.asd} files present in the sources are read to
7415 find system definitions. The @code{#:asd-files} parameter can be used
7416 to specify the list of @file{.asd} files to read. Furthermore, if the
7417 package defines a system for its tests in a separate file, it will be
7418 loaded before the tests are run if it is specified by the
7419 @code{#:test-asd-file} parameter. If it is not set, the files
7420 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
7421 and @code{test.asd} will be tried if they exist.
7423 If for some reason the package must be named in a different way than the
7424 naming conventions suggest, or if several systems must be compiled, the
7425 @code{#:asd-systems} parameter can be used to specify the list of system
7430 @defvr {Scheme Variable} cargo-build-system
7431 @cindex Rust programming language
7432 @cindex Cargo (Rust build system)
7433 This variable is exported by @code{(guix build-system cargo)}. It
7434 supports builds of packages using Cargo, the build tool of the
7435 @uref{https://www.rust-lang.org, Rust programming language}.
7437 It adds @code{rustc} and @code{cargo} to the set of inputs.
7438 A different Rust package can be specified with the @code{#:rust} parameter.
7440 Regular cargo dependencies should be added to the package definition via the
7441 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
7442 spec can be a package or a source definition. Note that the spec must
7443 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
7444 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
7445 should be added to the package definition via the
7446 @code{#:cargo-development-inputs} parameter.
7448 In its @code{configure} phase, this build system will make any source inputs
7449 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
7450 parameters available to cargo. It will also remove an included
7451 @code{Cargo.lock} file to be recreated by @code{cargo} during the
7452 @code{build} phase. The @code{install} phase installs the binaries
7453 defined by the crate.
7456 @defvr {Scheme Variable} chicken-build-system
7457 This variable is exported by @code{(guix build-system chicken)}. It
7458 builds @uref{https://call-cc.org/, CHICKEN Scheme} modules, also called
7459 ``eggs'' or ``extensions''. CHICKEN generates C source code, which then
7460 gets compiled by a C compiler, in this case GCC.
7462 This build system adds @code{chicken} to the package inputs, as well as
7463 the packages of @code{gnu-build-system}.
7465 The build system can't (yet) deduce the egg's name automatically, so just like
7466 with @code{go-build-system} and its @code{#:import-path}, you should define
7467 @code{#:egg-name} in the package's @code{arguments} field.
7469 For example, if you are packaging the @code{srfi-1} egg:
7472 (arguments '(#:egg-name "srfi-1"))
7475 Egg dependencies must be defined in @code{propagated-inputs}, not @code{inputs}
7476 because CHICKEN doesn't embed absolute references in compiled eggs.
7477 Test dependencies should go to @code{native-inputs}, as usual.
7480 @defvr {Scheme Variable} copy-build-system
7481 This variable is exported by @code{(guix build-system copy)}. It
7482 supports builds of simple packages that don't require much compiling,
7483 mostly just moving files around.
7485 It adds much of the @code{gnu-build-system} packages to the set of
7486 inputs. Because of this, the @code{copy-build-system} does not require
7487 all the boilerplate code often needed for the
7488 @code{trivial-build-system}.
7490 To further simplify the file installation process, an
7491 @code{#:install-plan} argument is exposed to let the packager specify
7492 which files go where. The install plan is a list of @code{(@var{source}
7493 @var{target} [@var{filters}])}. @var{filters} are optional.
7496 @item When @var{source} matches a file or directory without trailing slash, install it to @var{target}.
7498 @item If @var{target} has a trailing slash, install @var{source} basename beneath @var{target}.
7499 @item Otherwise install @var{source} as @var{target}.
7502 @item When @var{source} is a directory with a trailing slash, or when @var{filters} are used,
7503 the trailing slash of @var{target} is implied with the same meaning
7506 @item Without @var{filters}, install the full @var{source} @emph{content} to @var{target}.
7507 @item With @var{filters} among @code{#:include}, @code{#:include-regexp}, @code{#:exclude},
7508 @code{#:exclude-regexp}, only select files are installed depending on
7509 the filters. Each filters is specified by a list of strings.
7511 @item With @code{#:include}, install all the files which the path suffix matches
7512 at least one of the elements in the given list.
7513 @item With @code{#:include-regexp}, install all the files which the
7514 subpaths match at least one of the regular expressions in the given
7516 @item The @code{#:exclude} and @code{#:exclude-regexp} filters
7517 are the complement of their inclusion counterpart. Without @code{#:include} flags,
7518 install all files but those matching the exclusion filters.
7519 If both inclusions and exclusions are specified, the exclusions are done
7520 on top of the inclusions.
7523 In all cases, the paths relative to @var{source} are preserved within
7530 @item @code{("foo/bar" "share/my-app/")}: Install @file{bar} to @file{share/my-app/bar}.
7531 @item @code{("foo/bar" "share/my-app/baz")}: Install @file{bar} to @file{share/my-app/baz}.
7532 @item @code{("foo/" "share/my-app")}: Install the content of @file{foo} inside @file{share/my-app},
7533 e.g., install @file{foo/sub/file} to @file{share/my-app/sub/file}.
7534 @item @code{("foo/" "share/my-app" #:include ("sub/file"))}: Install only @file{foo/sub/file} to
7535 @file{share/my-app/sub/file}.
7536 @item @code{("foo/sub" "share/my-app" #:include ("file"))}: Install @file{foo/sub/file} to
7537 @file{share/my-app/file}.
7542 @cindex Clojure (programming language)
7543 @cindex simple Clojure build system
7544 @defvr {Scheme Variable} clojure-build-system
7545 This variable is exported by @code{(guix build-system clojure)}. It implements
7546 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
7547 using plain old @code{compile} in Clojure. Cross-compilation is not supported
7550 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
7551 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
7552 @code{#:zip} parameters, respectively.
7554 A list of source directories, test directories and jar names can be specified
7555 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
7556 parameters, respectively. Compile directory and main class can be specified
7557 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
7558 Other parameters are documented below.
7560 This build system is an extension of @code{ant-build-system}, but with the
7561 following phases changed:
7566 This phase calls @code{compile} in Clojure to compile source files and runs
7567 @command{jar} to create jars from both source files and compiled files
7568 according to the include list and exclude list specified in
7569 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
7570 has priority over the include list. These lists consist of symbols
7571 representing Clojure libraries or the special keyword @code{#:all} representing
7572 all Clojure libraries found under the source directories. The parameter
7573 @code{#:omit-source?} decides if source should be included into the jars.
7576 This phase runs tests according to the include list and exclude list specified
7577 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
7578 meanings are analogous to that of @code{#:aot-include} and
7579 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
7580 stands for all Clojure libraries found under the test directories. The
7581 parameter @code{#:tests?} decides if tests should be run.
7584 This phase installs all jars built previously.
7587 Apart from the above, this build system also contains an additional phase:
7592 This phase installs all top-level files with base name matching
7593 @code{%doc-regex}. A different regex can be specified with the
7594 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
7595 directories specified in @code{#:doc-dirs} are installed as well.
7599 @defvr {Scheme Variable} cmake-build-system
7600 This variable is exported by @code{(guix build-system cmake)}. It
7601 implements the build procedure for packages using the
7602 @url{https://www.cmake.org, CMake build tool}.
7604 It automatically adds the @code{cmake} package to the set of inputs.
7605 Which package is used can be specified with the @code{#:cmake}
7608 The @code{#:configure-flags} parameter is taken as a list of flags
7609 passed to the @command{cmake} command. The @code{#:build-type}
7610 parameter specifies in abstract terms the flags passed to the compiler;
7611 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
7612 debugging information''), which roughly means that code is compiled with
7613 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
7616 @defvr {Scheme Variable} dune-build-system
7617 This variable is exported by @code{(guix build-system dune)}. It
7618 supports builds of packages using @uref{https://dune.build/, Dune}, a build
7619 tool for the OCaml programming language. It is implemented as an extension
7620 of the @code{ocaml-build-system} which is described below. As such, the
7621 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
7624 It automatically adds the @code{dune} package to the set of inputs.
7625 Which package is used can be specified with the @code{#:dune}
7628 There is no @code{configure} phase because dune packages typically don't
7629 need to be configured. The @code{#:build-flags} parameter is taken as a
7630 list of flags passed to the @code{dune} command during the build.
7632 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
7633 command instead of the more recent @code{dune} command while building
7634 a package. Its default value is @code{#f}.
7636 The @code{#:package} parameter can be passed to specify a package name, which
7637 is useful when a package contains multiple packages and you want to build
7638 only one of them. This is equivalent to passing the @code{-p} argument to
7642 @defvr {Scheme Variable} go-build-system
7643 This variable is exported by @code{(guix build-system go)}. It
7644 implements a build procedure for Go packages using the standard
7645 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
7646 Go build mechanisms}.
7648 The user is expected to provide a value for the key @code{#:import-path}
7649 and, in some cases, @code{#:unpack-path}. The
7650 @url{https://golang.org/doc/code.html#ImportPaths, import path}
7651 corresponds to the file system path expected by the package's build
7652 scripts and any referring packages, and provides a unique way to
7653 refer to a Go package. It is typically based on a combination of the
7654 package source code's remote URI and file system hierarchy structure. In
7655 some cases, you will need to unpack the package's source code to a
7656 different directory structure than the one indicated by the import path,
7657 and @code{#:unpack-path} should be used in such cases.
7659 Packages that provide Go libraries should install their source code into
7660 the built output. The key @code{#:install-source?}, which defaults to
7661 @code{#t}, controls whether or not the source code is installed. It can
7662 be set to @code{#f} for packages that only provide executable files.
7665 @defvr {Scheme Variable} glib-or-gtk-build-system
7666 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
7667 is intended for use with packages making use of GLib or GTK+.
7669 This build system adds the following two phases to the ones defined by
7670 @code{gnu-build-system}:
7673 @item glib-or-gtk-wrap
7674 The phase @code{glib-or-gtk-wrap} ensures that programs in
7675 @file{bin/} are able to find GLib ``schemas'' and
7676 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
7677 modules}. This is achieved by wrapping the programs in launch scripts
7678 that appropriately set the @env{XDG_DATA_DIRS} and @env{GTK_PATH}
7679 environment variables.
7681 It is possible to exclude specific package outputs from that wrapping
7682 process by listing their names in the
7683 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
7684 when an output is known not to contain any GLib or GTK+ binaries, and
7685 where wrapping would gratuitously add a dependency of that output on
7688 @item glib-or-gtk-compile-schemas
7689 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
7690 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
7691 GSettings schemas} of GLib are compiled. Compilation is performed by the
7692 @command{glib-compile-schemas} program. It is provided by the package
7693 @code{glib:bin} which is automatically imported by the build system.
7694 The @code{glib} package providing @command{glib-compile-schemas} can be
7695 specified with the @code{#:glib} parameter.
7698 Both phases are executed after the @code{install} phase.
7701 @defvr {Scheme Variable} guile-build-system
7702 This build system is for Guile packages that consist exclusively of Scheme
7703 code and that are so lean that they don't even have a makefile, let alone a
7704 @file{configure} script. It compiles Scheme code using @command{guild
7705 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
7706 installs the @file{.scm} and @file{.go} files in the right place. It also
7707 installs documentation.
7709 This build system supports cross-compilation by using the
7710 @option{--target} option of @samp{guild compile}.
7712 Packages built with @code{guile-build-system} must provide a Guile package in
7713 their @code{native-inputs} field.
7716 @defvr {Scheme Variable} julia-build-system
7717 This variable is exported by @code{(guix build-system julia)}. It
7718 implements the build procedure used by @uref{https://julialang.org/,
7719 julia} packages, which essentially is similar to running @samp{julia -e
7720 'using Pkg; Pkg.add(package)'} in an environment where
7721 @env{JULIA_LOAD_PATH} contains the paths to all Julia package inputs.
7722 Tests are run by calling @code{/test/runtests.jl}.
7724 The Julia package name is read from the file @file{Project.toml}. This
7725 value can be overridden by passing the argument @code{#:julia-file-name}
7726 (which must be correctly capitalized).
7728 For packages requiring shared library dependencies, you may need to write the
7729 @file{/deps/deps.jl} file manually. It's usually a line of @code{const
7730 variable = /gnu/store/library.so} for each dependency, plus a void function
7731 @code{check_deps() = nothing}.
7733 Some older packages that aren't using @file{Package.toml} yet, will require
7734 this file to be created, too. The function @code{julia-create-package-toml}
7735 helps creating the file. You need to pass the outputs and the source of the
7736 package, it's name (the same as the @code{file-name} parameter), the package
7737 uuid, the package version, and a list of dependencies specified by their name
7741 @defvr {Scheme Variable} maven-build-system
7742 This variable is exported by @code{(guix build-system maven)}. It implements
7743 a build procedure for @uref{https://maven.apache.org, Maven} packages. Maven
7744 is a dependency and lifecycle management tool for Java. A user of Maven
7745 specifies dependencies and plugins in a @file{pom.xml} file that Maven reads.
7746 When Maven does not have one of the dependencies or plugins in its repository,
7747 it will download them and use them to build the package.
7749 The maven build system ensures that maven will not try to download any
7750 dependency by running in offline mode. Maven will fail if a dependency is
7751 missing. Before running Maven, the @file{pom.xml} (and subprojects) are
7752 modified to specify the version of dependencies and plugins that match the
7753 versions available in the guix build environment. Dependencies and plugins
7754 must be installed in the fake maven repository at @file{lib/m2}, and are
7755 symlinked into a proper repository before maven is run. Maven is instructed
7756 to use that repository for the build and installs built artifacts there.
7757 Changed files are copied to the @file{lib/m2} directory of the package output.
7759 You can specify a @file{pom.xml} file with the @code{#:pom-file} argument,
7760 or let the build system use the default @file{pom.xml} file in the sources.
7762 In case you need to specify a dependency's version manually, you can use the
7763 @code{#:local-packages} argument. It takes an association list where the key
7764 is the groupId of the package and its value is an association list where the
7765 key is the artifactId of the package and its value is the version you want to
7766 override in the @file{pom.xml}.
7768 Some packages use dependencies or plugins that are not useful at runtime nor
7769 at build time in Guix. You can alter the @file{pom.xml} file to remove them
7770 using the @code{#:exclude} argument. Its value is an association list where
7771 the key is the groupId of the plugin or dependency you want to remove, and
7772 the value is a list of artifactId you want to remove.
7774 You can override the default @code{jdk} and @code{maven} packages with the
7775 corresponding argument, @code{#:jdk} and @code{#:maven}.
7777 The @code{#:maven-plugins} argument is a list of maven plugins used during
7778 the build, with the same format as the @code{inputs} fields of the package
7779 declaration. Its default value is @code{(default-maven-plugins)} which is
7783 @defvr {Scheme Variable} minify-build-system
7784 This variable is exported by @code{(guix build-system minify)}. It
7785 implements a minification procedure for simple JavaScript packages.
7787 It adds @code{uglify-js} to the set of inputs and uses it to compress
7788 all JavaScript files in the @file{src} directory. A different minifier
7789 package can be specified with the @code{#:uglify-js} parameter, but it
7790 is expected that the package writes the minified code to the standard
7793 When the input JavaScript files are not all located in the @file{src}
7794 directory, the parameter @code{#:javascript-files} can be used to
7795 specify a list of file names to feed to the minifier.
7798 @defvr {Scheme Variable} ocaml-build-system
7799 This variable is exported by @code{(guix build-system ocaml)}. It implements
7800 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
7801 of choosing the correct set of commands to run for each package. OCaml
7802 packages can expect many different commands to be run. This build system will
7805 When the package has a @file{setup.ml} file present at the top-level, it will
7806 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
7807 @code{ocaml setup.ml -install}. The build system will assume that this file
7808 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
7809 care of setting the prefix and enabling tests if they are not disabled. You
7810 can pass configure and build flags with the @code{#:configure-flags} and
7811 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
7812 set of flags used to enable tests. The @code{#:use-make?} key can be used to
7813 bypass this system in the build and install phases.
7815 When the package has a @file{configure} file, it is assumed that it is a
7816 hand-made configure script that requires a different argument format than
7817 in the @code{gnu-build-system}. You can add more flags with the
7818 @code{#:configure-flags} key.
7820 When the package has a @file{Makefile} file (or @code{#:use-make?} is
7821 @code{#t}), it will be used and more flags can be passed to the build and
7822 install phases with the @code{#:make-flags} key.
7824 Finally, some packages do not have these files and use a somewhat standard
7825 location for its build system. In that case, the build system will run
7826 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
7827 providing the path to the required findlib module. Additional flags can
7828 be passed via the @code{#:build-flags} key. Install is taken care of by
7829 @command{opam-installer}. In this case, the @code{opam} package must
7830 be added to the @code{native-inputs} field of the package definition.
7832 Note that most OCaml packages assume they will be installed in the same
7833 directory as OCaml, which is not what we want in guix. In particular, they
7834 will install @file{.so} files in their module's directory, which is usually
7835 fine because it is in the OCaml compiler directory. In guix though, these
7836 libraries cannot be found and we use @env{CAML_LD_LIBRARY_PATH}. This
7837 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
7838 @file{.so} libraries should be installed.
7841 @defvr {Scheme Variable} python-build-system
7842 This variable is exported by @code{(guix build-system python)}. It
7843 implements the more or less standard build procedure used by Python
7844 packages, which consists in running @code{python setup.py build} and
7845 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
7847 For packages that install stand-alone Python programs under @code{bin/},
7848 it takes care of wrapping these programs so that their @env{PYTHONPATH}
7849 environment variable points to all the Python libraries they depend on.
7851 Which Python package is used to perform the build can be specified with
7852 the @code{#:python} parameter. This is a useful way to force a package
7853 to be built for a specific version of the Python interpreter, which
7854 might be necessary if the package is only compatible with a single
7855 interpreter version.
7857 By default guix calls @code{setup.py} under control of
7858 @code{setuptools}, much like @command{pip} does. Some packages are not
7859 compatible with setuptools (and pip), thus you can disable this by
7860 setting the @code{#:use-setuptools?} parameter to @code{#f}.
7863 @defvr {Scheme Variable} perl-build-system
7864 This variable is exported by @code{(guix build-system perl)}. It
7865 implements the standard build procedure for Perl packages, which either
7866 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
7867 followed by @code{Build} and @code{Build install}; or in running
7868 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
7869 @code{make} and @code{make install}, depending on which of
7870 @code{Build.PL} or @code{Makefile.PL} is present in the package
7871 distribution. Preference is given to the former if both @code{Build.PL}
7872 and @code{Makefile.PL} exist in the package distribution. This
7873 preference can be reversed by specifying @code{#t} for the
7874 @code{#:make-maker?} parameter.
7876 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
7877 passes flags specified by the @code{#:make-maker-flags} or
7878 @code{#:module-build-flags} parameter, respectively.
7880 Which Perl package is used can be specified with @code{#:perl}.
7883 @defvr {Scheme Variable} qt-build-system
7884 This variable is exported by @code{(guix build-system qt)}. It
7885 is intended for use with applications using Qt or KDE.
7887 This build system adds the following two phases to the ones defined by
7888 @code{cmake-build-system}:
7892 The phase @code{check-setup} prepares the environment for running
7893 the checks as commonly used by Qt test programs.
7894 For now this only sets some environment variables:
7895 @code{QT_QPA_PLATFORM=offscreen},
7896 @code{DBUS_FATAL_WARNINGS=0} and
7897 @code{CTEST_OUTPUT_ON_FAILURE=1}.
7899 This phase is added before the @code{check} phase.
7900 It's a separate phase to ease adjusting if necessary.
7903 The phase @code{qt-wrap}
7904 searches for Qt5 plugin paths, QML paths and some XDG in the inputs
7905 and output. In case some path is found, all programs in the output's
7906 @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
7907 are wrapped in scripts defining the necessary environment variables.
7909 It is possible to exclude specific package outputs from that wrapping process
7910 by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
7911 This is useful when an output is known not to contain any Qt binaries, and
7912 where wrapping would gratuitously add a dependency of that output on Qt, KDE,
7915 This phase is added after the @code{install} phase.
7919 @defvr {Scheme Variable} r-build-system
7920 This variable is exported by @code{(guix build-system r)}. It
7921 implements the build procedure used by @uref{https://r-project.org, R}
7922 packages, which essentially is little more than running @samp{R CMD
7923 INSTALL --library=/gnu/store/@dots{}} in an environment where
7924 @env{R_LIBS_SITE} contains the paths to all R package inputs. Tests are
7925 run after installation using the R function
7926 @code{tools::testInstalledPackage}.
7929 @defvr {Scheme Variable} rakudo-build-system
7930 This variable is exported by @code{(guix build-system rakudo)}. It
7931 implements the build procedure used by @uref{https://rakudo.org/,
7932 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
7933 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
7934 installs the binaries, library files and the resources, as well as wrap
7935 the files under the @code{bin/} directory. Tests can be skipped by
7936 passing @code{#f} to the @code{tests?} parameter.
7938 Which rakudo package is used can be specified with @code{rakudo}.
7939 Which perl6-tap-harness package used for the tests can be specified with
7940 @code{#:prove6} or removed by passing @code{#f} to the
7941 @code{with-prove6?} parameter.
7942 Which perl6-zef package used for tests and installing can be specified
7943 with @code{#:zef} or removed by passing @code{#f} to the
7944 @code{with-zef?} parameter.
7947 @defvr {Scheme Variable} texlive-build-system
7948 This variable is exported by @code{(guix build-system texlive)}. It is
7949 used to build TeX packages in batch mode with a specified engine. The
7950 build system sets the @env{TEXINPUTS} variable to find all TeX source
7951 files in the inputs.
7953 By default it runs @code{luatex} on all files ending on @code{ins}. A
7954 different engine and format can be specified with the
7955 @code{#:tex-format} argument. Different build targets can be specified
7956 with the @code{#:build-targets} argument, which expects a list of file
7957 names. The build system adds only @code{texlive-bin} and
7958 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
7959 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
7960 and @code{#:texlive-latex-base}, respectively.
7962 The @code{#:tex-directory} parameter tells the build system where to
7963 install the built files under the texmf tree.
7966 @defvr {Scheme Variable} ruby-build-system
7967 This variable is exported by @code{(guix build-system ruby)}. It
7968 implements the RubyGems build procedure used by Ruby packages, which
7969 involves running @code{gem build} followed by @code{gem install}.
7971 The @code{source} field of a package that uses this build system
7972 typically references a gem archive, since this is the format that Ruby
7973 developers use when releasing their software. The build system unpacks
7974 the gem archive, potentially patches the source, runs the test suite,
7975 repackages the gem, and installs it. Additionally, directories and
7976 tarballs may be referenced to allow building unreleased gems from Git or
7977 a traditional source release tarball.
7979 Which Ruby package is used can be specified with the @code{#:ruby}
7980 parameter. A list of additional flags to be passed to the @command{gem}
7981 command can be specified with the @code{#:gem-flags} parameter.
7984 @defvr {Scheme Variable} waf-build-system
7985 This variable is exported by @code{(guix build-system waf)}. It
7986 implements a build procedure around the @code{waf} script. The common
7987 phases---@code{configure}, @code{build}, and @code{install}---are
7988 implemented by passing their names as arguments to the @code{waf}
7991 The @code{waf} script is executed by the Python interpreter. Which
7992 Python package is used to run the script can be specified with the
7993 @code{#:python} parameter.
7996 @defvr {Scheme Variable} scons-build-system
7997 This variable is exported by @code{(guix build-system scons)}. It
7998 implements the build procedure used by the SCons software construction
7999 tool. This build system runs @code{scons} to build the package,
8000 @code{scons test} to run tests, and then @code{scons install} to install
8003 Additional flags to be passed to @code{scons} can be specified with the
8004 @code{#:scons-flags} parameter. The default build and install targets
8005 can be overridden with @code{#:build-targets} and
8006 @code{#:install-targets} respectively. The version of Python used to
8007 run SCons can be specified by selecting the appropriate SCons package
8008 with the @code{#:scons} parameter.
8011 @defvr {Scheme Variable} haskell-build-system
8012 This variable is exported by @code{(guix build-system haskell)}. It
8013 implements the Cabal build procedure used by Haskell packages, which
8014 involves running @code{runhaskell Setup.hs configure
8015 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
8016 Instead of installing the package by running @code{runhaskell Setup.hs
8017 install}, to avoid trying to register libraries in the read-only
8018 compiler store directory, the build system uses @code{runhaskell
8019 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
8020 addition, the build system generates the package documentation by
8021 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
8022 is passed. Optional Haddock parameters can be passed with the help of
8023 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
8024 not found, the build system looks for @code{Setup.lhs} instead.
8026 Which Haskell compiler is used can be specified with the @code{#:haskell}
8027 parameter which defaults to @code{ghc}.
8030 @defvr {Scheme Variable} dub-build-system
8031 This variable is exported by @code{(guix build-system dub)}. It
8032 implements the Dub build procedure used by D packages, which
8033 involves running @code{dub build} and @code{dub run}.
8034 Installation is done by copying the files manually.
8036 Which D compiler is used can be specified with the @code{#:ldc}
8037 parameter which defaults to @code{ldc}.
8040 @anchor{emacs-build-system}
8041 @defvr {Scheme Variable} emacs-build-system
8042 This variable is exported by @code{(guix build-system emacs)}. It
8043 implements an installation procedure similar to the packaging system
8044 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
8046 It first creates the @code{@code{package}-autoloads.el} file, then it
8047 byte compiles all Emacs Lisp files. Differently from the Emacs
8048 packaging system, the Info documentation files are moved to the standard
8049 documentation directory and the @file{dir} file is deleted. The Elisp
8050 package files are installed directly under @file{share/emacs/site-lisp}.
8053 @defvr {Scheme Variable} font-build-system
8054 This variable is exported by @code{(guix build-system font)}. It
8055 implements an installation procedure for font packages where upstream
8056 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
8057 need to be copied into place. It copies font files to standard
8058 locations in the output directory.
8061 @defvr {Scheme Variable} meson-build-system
8062 This variable is exported by @code{(guix build-system meson)}. It
8063 implements the build procedure for packages that use
8064 @url{https://mesonbuild.com, Meson} as their build system.
8066 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
8067 of inputs, and they can be changed with the parameters @code{#:meson}
8068 and @code{#:ninja} if needed. The default Meson is
8069 @code{meson-for-build}, which is special because it doesn't clear the
8070 @code{RUNPATH} of binaries and libraries when they are installed.
8072 This build system is an extension of @code{gnu-build-system}, but with the
8073 following phases changed to some specific for Meson:
8078 The phase runs @code{meson} with the flags specified in
8079 @code{#:configure-flags}. The flag @option{--buildtype} is always set to
8080 @code{debugoptimized} unless something else is specified in
8081 @code{#:build-type}.
8084 The phase runs @code{ninja} to build the package in parallel by default, but
8085 this can be changed with @code{#:parallel-build?}.
8088 The phase runs @code{ninja} with the target specified in @code{#:test-target},
8089 which is @code{"test"} by default.
8092 The phase runs @code{ninja install} and can not be changed.
8095 Apart from that, the build system also adds the following phases:
8100 This phase ensures that all binaries can find the libraries they need.
8101 It searches for required libraries in subdirectories of the package being
8102 built, and adds those to @code{RUNPATH} where needed. It also removes
8103 references to libraries left over from the build phase by
8104 @code{meson-for-build}, such as test dependencies, that aren't actually
8105 required for the program to run.
8107 @item glib-or-gtk-wrap
8108 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
8109 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
8111 @item glib-or-gtk-compile-schemas
8112 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
8113 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
8117 @defvr {Scheme Variable} linux-module-build-system
8118 @code{linux-module-build-system} allows building Linux kernel modules.
8120 @cindex build phases
8121 This build system is an extension of @code{gnu-build-system}, but with the
8122 following phases changed:
8127 This phase configures the environment so that the Linux kernel's Makefile
8128 can be used to build the external kernel module.
8131 This phase uses the Linux kernel's Makefile in order to build the external
8135 This phase uses the Linux kernel's Makefile in order to install the external
8139 It is possible and useful to specify the Linux kernel to use for building
8140 the module (in the @code{arguments} form of a package using the
8141 @code{linux-module-build-system}, use the key @code{#:linux} to specify it).
8144 @defvr {Scheme Variable} node-build-system
8145 This variable is exported by @code{(guix build-system node)}. It
8146 implements the build procedure used by @uref{https://nodejs.org,
8147 Node.js}, which implements an approximation of the @code{npm install}
8148 command, followed by an @code{npm test} command.
8150 Which Node.js package is used to interpret the @code{npm} commands can
8151 be specified with the @code{#:node} parameter which defaults to
8155 Lastly, for packages that do not need anything as sophisticated, a
8156 ``trivial'' build system is provided. It is trivial in the sense that
8157 it provides basically no support: it does not pull any implicit inputs,
8158 and does not have a notion of build phases.
8160 @defvr {Scheme Variable} trivial-build-system
8161 This variable is exported by @code{(guix build-system trivial)}.
8163 This build system requires a @code{#:builder} argument. This argument
8164 must be a Scheme expression that builds the package output(s)---as
8165 with @code{build-expression->derivation} (@pxref{Derivations,
8166 @code{build-expression->derivation}}).
8170 @section Build Phases
8172 @cindex build phases, for packages
8173 Almost all package build systems implement a notion @dfn{build phases}:
8174 a sequence of actions that the build system executes, when you build the
8175 package, leading to the installed byproducts in the store. A notable
8176 exception is the ``bare-bones'' @code{trivial-build-system}
8177 (@pxref{Build Systems}).
8179 As discussed in the previous section, those build systems provide a
8180 standard list of phases. For @code{gnu-build-system}, the standard
8181 phases include an @code{unpack} phase to unpack the source code tarball,
8182 a @command{configure} phase to run @code{./configure}, a @code{build}
8183 phase to run @command{make}, and (among others) an @code{install} phase
8184 to run @command{make install}; @pxref{Build Systems}, for a more
8185 detailed view of these phases. Likewise, @code{cmake-build-system}
8186 inherits these phases, but its @code{configure} phase runs
8187 @command{cmake} instead of @command{./configure}. Other build systems,
8188 such as @code{python-build-system}, have a wholly different list of
8189 standard phases. All this code runs on the @dfn{build side}: it is
8190 evaluated when you actually build the package, in a dedicated build
8191 process spawned by the build daemon (@pxref{Invoking guix-daemon}).
8193 Build phases are represented as association lists or ``alists''
8194 (@pxref{Association Lists,,, guile, GNU Guile Reference Manual}) where
8195 each key is a symbol for the name of the phase and the associated value
8196 is a procedure that accepts an arbitrary number of arguments. By
8197 convention, those procedures receive information about the build in the
8198 form of @dfn{keyword parameters}, which they can use or ignore.
8200 For example, here is how @code{(guix build gnu-build-system)} defines
8201 @code{%standard-phases}, the variable holding its alist of build
8202 phases@footnote{We present a simplified view of those build phases, but
8203 do take a look at @code{(guix build gnu-build-system)} to see all the
8207 ;; The build phases of 'gnu-build-system'.
8209 (define* (unpack #:key source #:allow-other-keys)
8210 ;; Extract the source tarball.
8211 (invoke "tar" "xvf" source))
8213 (define* (configure #:key outputs #:allow-other-keys)
8214 ;; Run the 'configure' script. Install to output "out".
8215 (let ((out (assoc-ref outputs "out")))
8216 (invoke "./configure"
8217 (string-append "--prefix=" out))))
8219 (define* (build #:allow-other-keys)
8223 (define* (check #:key (test-target "check") (tests? #true)
8225 ;; Run the test suite.
8227 (invoke "make" test-target)
8228 (display "test suite not run\n")))
8230 (define* (install #:allow-other-keys)
8231 ;; Install files to the prefix 'configure' specified.
8232 (invoke "make" "install"))
8234 (define %standard-phases
8235 ;; The list of standard phases (quite a few are omitted
8236 ;; for brevity). Each element is a symbol/procedure pair.
8237 (list (cons 'unpack unpack)
8238 (cons 'configure configure)
8241 (cons 'install install)))
8244 This shows how @code{%standard-phases} is defined as a list of
8245 symbol/procedure pairs (@pxref{Pairs,,, guile, GNU Guile Reference
8246 Manual}). The first pair associates the @code{unpack} procedure with
8247 the @code{unpack} symbol---a name; the second pair defines the
8248 @code{configure} phase similarly, and so on. When building a package
8249 that uses @code{gnu-build-system} with its default list of phases, those
8250 phases are executed sequentially. You can see the name of each phase
8251 started and completed in the build log of packages that you build.
8253 Let's now look at the procedures themselves. Each one is defined with
8254 @code{define*}: @code{#:key} lists keyword parameters the procedure
8255 accepts, possibly with a default value, and @code{#:allow-other-keys}
8256 specifies that other keyword parameters are ignored (@pxref{Optional
8257 Arguments,,, guile, GNU Guile Reference Manual}).
8259 The @code{unpack} procedure honors the @code{source} parameter, which
8260 the build system uses to pass the file name of the source tarball (or
8261 version control checkout), and it ignores other parameters. The
8262 @code{configure} phase only cares about the @code{outputs} parameter, an
8263 alist mapping package output names to their store file name
8264 (@pxref{Packages with Multiple Outputs}). It extracts the file name of
8265 for @code{out}, the default output, and passes it to
8266 @command{./configure} as the installation prefix, meaning that
8267 @command{make install} will eventually copy all the files in that
8268 directory (@pxref{Configuration, configuration and makefile
8269 conventions,, standards, GNU Coding Standards}). @code{build} and
8270 @code{install} ignore all their arguments. @code{check} honors the
8271 @code{test-target} argument, which specifies the name of the Makefile
8272 target to run tests; it prints a message and skips tests when
8273 @code{tests?} is false.
8275 @cindex build phases, customizing
8276 The list of phases used for a particular package can be changed with the
8277 @code{#:phases} parameter of the build system. Changing the set of
8278 build phases boils down to building a new alist of phases based on the
8279 @code{%standard-phases} alist described above. This can be done with
8280 standard alist procedures such as @code{alist-delete} (@pxref{SRFI-1
8281 Association Lists,,, guile, GNU Guile Reference Manual}); however, it is
8282 more convenient to do so with @code{modify-phases} (@pxref{Build
8283 Utilities, @code{modify-phases}}).
8285 Here is an example of a package definition that removes the
8286 @code{configure} phase of @code{%standard-phases} and inserts a new
8287 phase before the @code{build} phase, called
8288 @code{set-prefix-in-makefile}:
8291 (define-public example
8294 ;; other fields omitted
8295 (build-system gnu-build-system)
8297 '(#:phases (modify-phases %standard-phases
8299 (add-before 'build 'set-prefix-in-makefile
8300 (lambda* (#:key outputs #:allow-other-keys)
8301 ;; Modify the makefile so that its
8302 ;; 'PREFIX' variable points to "out".
8303 (let ((out (assoc-ref outputs "out")))
8304 (substitute* "Makefile"
8306 (string-append "PREFIX = "
8311 The new phase that is inserted is written as an anonymous procedure,
8312 introduced with @code{lambda*}; it honors the @code{outputs} parameter
8313 we have seen before. @xref{Build Utilities}, for more about the helpers
8314 used by this phase, and for more examples of @code{modify-phases}.
8316 @cindex code staging
8317 @cindex staging, of code
8318 Keep in mind that build phases are code evaluated at the time the
8319 package is actually built. This explains why the whole
8320 @code{modify-phases} expression above is quoted (it comes after the
8321 @code{'} or apostrophe): it is @dfn{staged} for later execution.
8322 @xref{G-Expressions}, for an explanation of code staging and the
8323 @dfn{code strata} involved.
8325 @node Build Utilities
8326 @section Build Utilities
8328 As soon as you start writing non-trivial package definitions
8329 (@pxref{Defining Packages}) or other build actions
8330 (@pxref{G-Expressions}), you will likely start looking for helpers for
8331 ``shell-like'' actions---creating directories, copying and deleting
8332 files recursively, manipulating build phases, and so on. The
8333 @code{(guix build utils)} module provides such utility procedures.
8335 Most build systems load @code{(guix build utils)} (@pxref{Build
8336 Systems}). Thus, when writing custom build phases for your package
8337 definitions, you can usually assume those procedures are in scope.
8339 When writing G-expressions, you can import @code{(guix build utils)} on
8340 the ``build side'' using @code{with-imported-modules} and then put it in
8341 scope with the @code{use-modules} form (@pxref{Using Guile Modules,,,
8342 guile, GNU Guile Reference Manual}):
8345 (with-imported-modules '((guix build utils)) ;import it
8346 (computed-file "empty-tree"
8349 (use-modules (guix build utils))
8351 ;; Happily use its 'mkdir-p' procedure.
8352 (mkdir-p (string-append #$output "/a/b/c")))))
8355 The remainder of this section is the reference for most of the utility
8356 procedures provided by @code{(guix build utils)}.
8358 @c TODO Document what's missing.
8360 @subsection Dealing with Store File Names
8362 This section documents procedures that deal with store file names.
8364 @deffn {Scheme Procedure} %store-directory
8365 Return the directory name of the store.
8368 @deffn {Scheme Procedure} store-file-name? @var{file}
8369 Return true if @var{file} is in the store.
8372 @deffn {Scheme Procedure} strip-store-file-name @var{file}
8373 Strip the @file{/gnu/store} and hash from @var{file}, a store file name.
8374 The result is typically a @code{"@var{package}-@var{version}"} string.
8377 @deffn {Scheme Procedure} package-name->name+version @var{name}
8378 Given @var{name}, a package name like @code{"foo-0.9.1b"}, return two
8379 values: @code{"foo"} and @code{"0.9.1b"}. When the version part is
8380 unavailable, @var{name} and @code{#f} are returned. The first hyphen
8381 followed by a digit is considered to introduce the version part.
8384 @subsection File Types
8386 The procedures below deal with files and file types.
8388 @deffn {Scheme Procedure} directory-exists? @var{dir}
8389 Return @code{#t} if @var{dir} exists and is a directory.
8392 @deffn {Scheme Procedure} executable-file? @var{file}
8393 Return @code{#t} if @var{file} exists and is executable.
8396 @deffn {Scheme Procedure} symbolic-link? @var{file}
8397 Return @code{#t} if @var{file} is a symbolic link (aka. a ``symlink'').
8400 @deffn {Scheme Procedure} elf-file? @var{file}
8401 @deffnx {Scheme Procedure} ar-file? @var{file}
8402 @deffnx {Scheme Procedure} gzip-file? @var{file}
8403 Return @code{#t} if @var{file} is, respectively, an ELF file, an
8404 @code{ar} archive (such as a @file{.a} static library), or a gzip file.
8407 @deffn {Scheme Procedure} reset-gzip-timestamp @var{file} [#:keep-mtime? #t]
8408 If @var{file} is a gzip file, reset its embedded timestamp (as with
8409 @command{gzip --no-name}) and return true. Otherwise return @code{#f}.
8410 When @var{keep-mtime?} is true, preserve @var{file}'s modification time.
8413 @subsection File Manipulation
8415 The following procedures and macros help create, modify, and delete
8416 files. They provide functionality comparable to common shell utilities
8417 such as @command{mkdir -p}, @command{cp -r}, @command{rm -r}, and
8418 @command{sed}. They complement Guile's extensive, but low-level, file
8419 system interface (@pxref{POSIX,,, guile, GNU Guile Reference Manual}).
8421 @deffn {Scheme Syntax} with-directory-excursion @var{directory} @var{body}@dots{}
8422 Run @var{body} with @var{directory} as the process's current directory.
8424 Essentially, this macro changes the current directory to @var{directory}
8425 before evaluating @var{body}, using @code{chdir} (@pxref{Processes,,,
8426 guile, GNU Guile Reference Manual}). It changes back to the initial
8427 directory when the dynamic extent of @var{body} is left, be it @i{via}
8428 normal procedure return or @i{via} a non-local exit such as an
8432 @deffn {Scheme Procedure} mkdir-p @var{dir}
8433 Create directory @var{dir} and all its ancestors.
8436 @deffn {Scheme Procedure} install-file @var{file} @var{directory}
8437 Create @var{directory} if it does not exist and copy @var{file} in there
8438 under the same name.
8441 @deffn {Scheme Procedure} make-file-writable @var{file}
8442 Make @var{file} writable for its owner.
8445 @deffn {Scheme Procedure} copy-recursively @var{source} @var{destination} @
8446 [#:log (current-output-port)] [#:follow-symlinks? #f] [#:keep-mtime? #f]
8447 Copy @var{source} directory to @var{destination}. Follow symlinks if
8448 @var{follow-symlinks?} is true; otherwise, just preserve them. When
8449 @var{keep-mtime?} is true, keep the modification time of the files in
8450 @var{source} on those of @var{destination}. Write verbose output to the
8454 @deffn {Scheme Procedure} delete-file-recursively @var{dir} @
8455 [#:follow-mounts? #f]
8456 Delete @var{dir} recursively, like @command{rm -rf}, without following
8457 symlinks. Don't follow mount points either, unless @var{follow-mounts?}
8458 is true. Report but ignore errors.
8461 @deffn {Scheme Syntax} substitute* @var{file} @
8462 ((@var{regexp} @var{match-var}@dots{}) @var{body}@dots{}) @dots{}
8463 Substitute @var{regexp} in @var{file} by the string returned by
8464 @var{body}. @var{body} is evaluated with each @var{match-var} bound to
8465 the corresponding positional regexp sub-expression. For example:
8471 (("foo([a-z]+)bar(.*)$" all letters end)
8472 (string-append "baz" letter end)))
8475 Here, anytime a line of @var{file} contains @code{hello}, it is replaced
8476 by @code{good morning}. Anytime a line of @var{file} matches the second
8477 regexp, @code{all} is bound to the complete match, @code{letters} is bound
8478 to the first sub-expression, and @code{end} is bound to the last one.
8480 When one of the @var{match-var} is @code{_}, no variable is bound to the
8481 corresponding match substring.
8483 Alternatively, @var{file} may be a list of file names, in which case
8484 they are all subject to the substitutions.
8486 Be careful about using @code{$} to match the end of a line; by itself it
8487 won't match the terminating newline of a line.
8490 @subsection File Search
8492 @cindex file, searching
8493 This section documents procedures to search and filter files.
8495 @deffn {Scheme Procedure} file-name-predicate @var{regexp}
8496 Return a predicate that returns true when passed a file name whose base
8497 name matches @var{regexp}.
8500 @deffn {Scheme Procedure} find-files @var{dir} [@var{pred}] @
8501 [#:stat lstat] [#:directories? #f] [#:fail-on-error? #f]
8502 Return the lexicographically sorted list of files under @var{dir} for
8503 which @var{pred} returns true. @var{pred} is passed two arguments: the
8504 absolute file name, and its stat buffer; the default predicate always
8505 returns true. @var{pred} can also be a regular expression, in which
8506 case it is equivalent to @code{(file-name-predicate @var{pred})}.
8507 @var{stat} is used to obtain file information; using @code{lstat} means
8508 that symlinks are not followed. If @var{directories?} is true, then
8509 directories will also be included. If @var{fail-on-error?} is true,
8510 raise an exception upon error.
8513 Here are a few examples where we assume that the current directory is
8514 the root of the Guix source tree:
8517 ;; List all the regular files in the current directory.
8519 @result{} ("./.dir-locals.el" "./.gitignore" @dots{})
8521 ;; List all the .scm files under gnu/services.
8522 (find-files "gnu/services" "\\.scm$")
8523 @result{} ("gnu/services/admin.scm" "gnu/services/audio.scm" @dots{})
8525 ;; List ar files in the current directory.
8526 (find-files "." (lambda (file stat) (ar-file? file)))
8527 @result{} ("./libformat.a" "./libstore.a" @dots{})
8530 @deffn {Scheme Procedure} which @var{program}
8531 Return the complete file name for @var{program} as found in
8532 @code{$PATH}, or @code{#f} if @var{program} could not be found.
8535 @subsection Build Phases
8537 @cindex build phases
8538 The @code{(guix build utils)} also contains tools to manipulate build
8539 phases as used by build systems (@pxref{Build Systems}). Build phases
8540 are represented as association lists or ``alists'' (@pxref{Association
8541 Lists,,, guile, GNU Guile Reference Manual}) where each key is a symbol
8542 naming the phase and the associated value is a procedure (@pxref{Build
8545 Guile core and the @code{(srfi srfi-1)} module both provide tools to
8546 manipulate alists. The @code{(guix build utils)} module complements
8547 those with tools written with build phases in mind.
8549 @cindex build phases, modifying
8550 @deffn {Scheme Syntax} modify-phases @var{phases} @var{clause}@dots{}
8551 Modify @var{phases} sequentially as per each @var{clause}, which may
8552 have one of the following forms:
8555 (delete @var{old-phase-name})
8556 (replace @var{old-phase-name} @var{new-phase})
8557 (add-before @var{old-phase-name} @var{new-phase-name} @var{new-phase})
8558 (add-after @var{old-phase-name} @var{new-phase-name} @var{new-phase})
8561 Where every @var{phase-name} above is an expression evaluating to a
8562 symbol, and @var{new-phase} an expression evaluating to a procedure.
8565 The example below is taken from the definition of the @code{grep}
8566 package. It adds a phase to run after the @code{install} phase, called
8567 @code{fix-egrep-and-fgrep}. That phase is a procedure (@code{lambda*}
8568 is for anonymous procedures) that takes a @code{#:outputs} keyword
8569 argument and ignores extra keyword arguments (@pxref{Optional
8570 Arguments,,, guile, GNU Guile Reference Manual}, for more on
8571 @code{lambda*} and optional and keyword arguments.) The phase uses
8572 @code{substitute*} to modify the installed @file{egrep} and @file{fgrep}
8573 scripts so that they refer to @code{grep} by its absolute file name:
8576 (modify-phases %standard-phases
8577 (add-after 'install 'fix-egrep-and-fgrep
8578 ;; Patch 'egrep' and 'fgrep' to execute 'grep' via its
8579 ;; absolute file name instead of searching for it in $PATH.
8580 (lambda* (#:key outputs #:allow-other-keys)
8581 (let* ((out (assoc-ref outputs "out"))
8582 (bin (string-append out "/bin")))
8583 (substitute* (list (string-append bin "/egrep")
8584 (string-append bin "/fgrep"))
8586 (string-append "exec " bin "/grep")))
8590 In the example below, phases are modified in two ways: the standard
8591 @code{configure} phase is deleted, presumably because the package does
8592 not have a @file{configure} script or anything similar, and the default
8593 @code{install} phase is replaced by one that manually copies the
8594 executable files to be installed:
8597 (modify-phases %standard-phases
8598 (delete 'configure) ;no 'configure' script
8600 (lambda* (#:key outputs #:allow-other-keys)
8601 ;; The package's Makefile doesn't provide an "install"
8602 ;; rule so do it by ourselves.
8603 (let ((bin (string-append (assoc-ref outputs "out")
8605 (install-file "footswitch" bin)
8606 (install-file "scythe" bin)
8610 @c TODO: Add more examples.
8619 Conceptually, the @dfn{store} is the place where derivations that have
8620 been built successfully are stored---by default, @file{/gnu/store}.
8621 Sub-directories in the store are referred to as @dfn{store items} or
8622 sometimes @dfn{store paths}. The store has an associated database that
8623 contains information such as the store paths referred to by each store
8624 path, and the list of @emph{valid} store items---results of successful
8625 builds. This database resides in @file{@var{localstatedir}/guix/db},
8626 where @var{localstatedir} is the state directory specified @i{via}
8627 @option{--localstatedir} at configure time, usually @file{/var}.
8629 The store is @emph{always} accessed by the daemon on behalf of its clients
8630 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
8631 connect to the daemon over a Unix-domain socket, send requests to it,
8632 and read the result---these are remote procedure calls, or RPCs.
8635 Users must @emph{never} modify files under @file{/gnu/store} directly.
8636 This would lead to inconsistencies and break the immutability
8637 assumptions of Guix's functional model (@pxref{Introduction}).
8639 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
8640 how to check the integrity of the store and attempt recovery from
8641 accidental modifications.
8644 The @code{(guix store)} module provides procedures to connect to the
8645 daemon, and to perform RPCs. These are described below. By default,
8646 @code{open-connection}, and thus all the @command{guix} commands,
8647 connect to the local daemon or to the URI specified by the
8648 @env{GUIX_DAEMON_SOCKET} environment variable.
8650 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
8651 When set, the value of this variable should be a file name or a URI
8652 designating the daemon endpoint. When it is a file name, it denotes a
8653 Unix-domain socket to connect to. In addition to file names, the
8654 supported URI schemes are:
8659 These are for Unix-domain sockets.
8660 @code{file:///var/guix/daemon-socket/socket} is equivalent to
8661 @file{/var/guix/daemon-socket/socket}.
8664 @cindex daemon, remote access
8665 @cindex remote access to the daemon
8666 @cindex daemon, cluster setup
8667 @cindex clusters, daemon setup
8668 These URIs denote connections over TCP/IP, without encryption nor
8669 authentication of the remote host. The URI must specify the host name
8670 and optionally a port number (by default port 44146 is used):
8673 guix://master.guix.example.org:1234
8676 This setup is suitable on local networks, such as clusters, where only
8677 trusted nodes may connect to the build daemon at
8678 @code{master.guix.example.org}.
8680 The @option{--listen} option of @command{guix-daemon} can be used to
8681 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
8682 @option{--listen}}).
8685 @cindex SSH access to build daemons
8686 These URIs allow you to connect to a remote daemon over SSH@. This
8687 feature requires Guile-SSH (@pxref{Requirements}) and a working
8688 @command{guile} binary in @env{PATH} on the destination machine. It
8689 supports public key and GSSAPI authentication. A typical URL might look
8693 ssh://charlie@@guix.example.org:22
8696 As for @command{guix copy}, the usual OpenSSH client configuration files
8697 are honored (@pxref{Invoking guix copy}).
8700 Additional URI schemes may be supported in the future.
8702 @c XXX: Remove this note when the protocol incurs fewer round trips
8703 @c and when (guix derivations) no longer relies on file system access.
8705 The ability to connect to remote build daemons is considered
8706 experimental as of @value{VERSION}. Please get in touch with us to
8707 share any problems or suggestions you may have (@pxref{Contributing}).
8711 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
8712 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
8713 @var{reserve-space?} is true, instruct it to reserve a little bit of
8714 extra space on the file system so that the garbage collector can still
8715 operate should the disk become full. Return a server object.
8717 @var{file} defaults to @code{%default-socket-path}, which is the normal
8718 location given the options that were passed to @command{configure}.
8721 @deffn {Scheme Procedure} close-connection @var{server}
8722 Close the connection to @var{server}.
8725 @defvr {Scheme Variable} current-build-output-port
8726 This variable is bound to a SRFI-39 parameter, which refers to the port
8727 where build and error logs sent by the daemon should be written.
8730 Procedures that make RPCs all take a server object as their first
8733 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
8734 @cindex invalid store items
8735 Return @code{#t} when @var{path} designates a valid store item and
8736 @code{#f} otherwise (an invalid item may exist on disk but still be
8737 invalid, for instance because it is the result of an aborted or failed
8740 A @code{&store-protocol-error} condition is raised if @var{path} is not
8741 prefixed by the store directory (@file{/gnu/store}).
8744 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
8745 Add @var{text} under file @var{name} in the store, and return its store
8746 path. @var{references} is the list of store paths referred to by the
8747 resulting store path.
8750 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
8752 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
8753 file names, or derivation/output pairs, using the specified
8754 @var{mode}---@code{(build-mode normal)} by default.
8757 Note that the @code{(guix monads)} module provides a monad as well as
8758 monadic versions of the above procedures, with the goal of making it
8759 more convenient to work with code that accesses the store (@pxref{The
8763 @i{This section is currently incomplete.}
8766 @section Derivations
8769 Low-level build actions and the environment in which they are performed
8770 are represented by @dfn{derivations}. A derivation contains the
8771 following pieces of information:
8775 The outputs of the derivation---derivations produce at least one file or
8776 directory in the store, but may produce more.
8779 @cindex build-time dependencies
8780 @cindex dependencies, build-time
8781 The inputs of the derivations---i.e., its build-time dependencies---which may
8782 be other derivations or plain files in the store (patches, build scripts,
8786 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
8789 The file name of a build script in the store, along with the arguments
8793 A list of environment variables to be defined.
8797 @cindex derivation path
8798 Derivations allow clients of the daemon to communicate build actions to
8799 the store. They exist in two forms: as an in-memory representation,
8800 both on the client- and daemon-side, and as files in the store whose
8801 name end in @file{.drv}---these files are referred to as @dfn{derivation
8802 paths}. Derivations paths can be passed to the @code{build-derivations}
8803 procedure to perform the build actions they prescribe (@pxref{The
8806 @cindex fixed-output derivations
8807 Operations such as file downloads and version-control checkouts for
8808 which the expected content hash is known in advance are modeled as
8809 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
8810 of a fixed-output derivation are independent of its inputs---e.g., a
8811 source code download produces the same result regardless of the download
8812 method and tools being used.
8815 @cindex run-time dependencies
8816 @cindex dependencies, run-time
8817 The outputs of derivations---i.e., the build results---have a set of
8818 @dfn{references}, as reported by the @code{references} RPC or the
8819 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
8820 are the set of run-time dependencies of the build results. References are a
8821 subset of the inputs of the derivation; this subset is automatically computed
8822 by the build daemon by scanning all the files in the outputs.
8824 The @code{(guix derivations)} module provides a representation of
8825 derivations as Scheme objects, along with procedures to create and
8826 otherwise manipulate derivations. The lowest-level primitive to create
8827 a derivation is the @code{derivation} procedure:
8829 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
8830 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
8831 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
8832 [#:system (%current-system)] [#:references-graphs #f] @
8833 [#:allowed-references #f] [#:disallowed-references #f] @
8834 [#:leaked-env-vars #f] [#:local-build? #f] @
8835 [#:substitutable? #t] [#:properties '()]
8836 Build a derivation with the given arguments, and return the resulting
8837 @code{<derivation>} object.
8839 When @var{hash} and @var{hash-algo} are given, a
8840 @dfn{fixed-output derivation} is created---i.e., one whose result is
8841 known in advance, such as a file download. If, in addition,
8842 @var{recursive?} is true, then that fixed output may be an executable
8843 file or a directory and @var{hash} must be the hash of an archive
8844 containing this output.
8846 When @var{references-graphs} is true, it must be a list of file
8847 name/store path pairs. In that case, the reference graph of each store
8848 path is exported in the build environment in the corresponding file, in
8849 a simple text format.
8851 When @var{allowed-references} is true, it must be a list of store items
8852 or outputs that the derivation's output may refer to. Likewise,
8853 @var{disallowed-references}, if true, must be a list of things the
8854 outputs may @emph{not} refer to.
8856 When @var{leaked-env-vars} is true, it must be a list of strings
8857 denoting environment variables that are allowed to ``leak'' from the
8858 daemon's environment to the build environment. This is only applicable
8859 to fixed-output derivations---i.e., when @var{hash} is true. The main
8860 use is to allow variables such as @code{http_proxy} to be passed to
8861 derivations that download files.
8863 When @var{local-build?} is true, declare that the derivation is not a
8864 good candidate for offloading and should rather be built locally
8865 (@pxref{Daemon Offload Setup}). This is the case for small derivations
8866 where the costs of data transfers would outweigh the benefits.
8868 When @var{substitutable?} is false, declare that substitutes of the
8869 derivation's output should not be used (@pxref{Substitutes}). This is
8870 useful, for instance, when building packages that capture details of the
8871 host CPU instruction set.
8873 @var{properties} must be an association list describing ``properties'' of the
8874 derivation. It is kept as-is, uninterpreted, in the derivation.
8878 Here's an example with a shell script as its builder, assuming
8879 @var{store} is an open connection to the daemon, and @var{bash} points
8880 to a Bash executable in the store:
8883 (use-modules (guix utils)
8887 (let ((builder ; add the Bash script to the store
8888 (add-text-to-store store "my-builder.sh"
8889 "echo hello world > $out\n" '())))
8890 (derivation store "foo"
8891 bash `("-e" ,builder)
8892 #:inputs `((,bash) (,builder))
8893 #:env-vars '(("HOME" . "/homeless"))))
8894 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
8897 As can be guessed, this primitive is cumbersome to use directly. A
8898 better approach is to write build scripts in Scheme, of course! The
8899 best course of action for that is to write the build code as a
8900 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
8901 information, @pxref{G-Expressions}.
8903 Once upon a time, @code{gexp->derivation} did not exist and constructing
8904 derivations with build code written in Scheme was achieved with
8905 @code{build-expression->derivation}, documented below. This procedure
8906 is now deprecated in favor of the much nicer @code{gexp->derivation}.
8908 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
8909 @var{name} @var{exp} @
8910 [#:system (%current-system)] [#:inputs '()] @
8911 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
8912 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
8913 [#:references-graphs #f] [#:allowed-references #f] @
8914 [#:disallowed-references #f] @
8915 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
8916 Return a derivation that executes Scheme expression @var{exp} as a
8917 builder for derivation @var{name}. @var{inputs} must be a list of
8918 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
8919 @code{"out"} is assumed. @var{modules} is a list of names of Guile
8920 modules from the current search path to be copied in the store,
8921 compiled, and made available in the load path during the execution of
8922 @var{exp}---e.g., @code{((guix build utils) (guix build
8923 gnu-build-system))}.
8925 @var{exp} is evaluated in an environment where @code{%outputs} is bound
8926 to a list of output/path pairs, and where @code{%build-inputs} is bound
8927 to a list of string/output-path pairs made from @var{inputs}.
8928 Optionally, @var{env-vars} is a list of string pairs specifying the name
8929 and value of environment variables visible to the builder. The builder
8930 terminates by passing the result of @var{exp} to @code{exit}; thus, when
8931 @var{exp} returns @code{#f}, the build is considered to have failed.
8933 @var{exp} is built using @var{guile-for-build} (a derivation). When
8934 @var{guile-for-build} is omitted or is @code{#f}, the value of the
8935 @code{%guile-for-build} fluid is used instead.
8937 See the @code{derivation} procedure for the meaning of
8938 @var{references-graphs}, @var{allowed-references},
8939 @var{disallowed-references}, @var{local-build?}, and
8940 @var{substitutable?}.
8944 Here's an example of a single-output derivation that creates a directory
8945 containing one file:
8948 (let ((builder '(let ((out (assoc-ref %outputs "out")))
8949 (mkdir out) ; create /gnu/store/@dots{}-goo
8950 (call-with-output-file (string-append out "/test")
8952 (display '(hello guix) p))))))
8953 (build-expression->derivation store "goo" builder))
8955 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
8959 @node The Store Monad
8960 @section The Store Monad
8964 The procedures that operate on the store described in the previous
8965 sections all take an open connection to the build daemon as their first
8966 argument. Although the underlying model is functional, they either have
8967 side effects or depend on the current state of the store.
8969 The former is inconvenient: the connection to the build daemon has to be
8970 carried around in all those functions, making it impossible to compose
8971 functions that do not take that parameter with functions that do. The
8972 latter can be problematic: since store operations have side effects
8973 and/or depend on external state, they have to be properly sequenced.
8975 @cindex monadic values
8976 @cindex monadic functions
8977 This is where the @code{(guix monads)} module comes in. This module
8978 provides a framework for working with @dfn{monads}, and a particularly
8979 useful monad for our uses, the @dfn{store monad}. Monads are a
8980 construct that allows two things: associating ``context'' with values
8981 (in our case, the context is the store), and building sequences of
8982 computations (here computations include accesses to the store). Values
8983 in a monad---values that carry this additional context---are called
8984 @dfn{monadic values}; procedures that return such values are called
8985 @dfn{monadic procedures}.
8987 Consider this ``normal'' procedure:
8990 (define (sh-symlink store)
8991 ;; Return a derivation that symlinks the 'bash' executable.
8992 (let* ((drv (package-derivation store bash))
8993 (out (derivation->output-path drv))
8994 (sh (string-append out "/bin/bash")))
8995 (build-expression->derivation store "sh"
8996 `(symlink ,sh %output))))
8999 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
9000 as a monadic function:
9003 (define (sh-symlink)
9004 ;; Same, but return a monadic value.
9005 (mlet %store-monad ((drv (package->derivation bash)))
9006 (gexp->derivation "sh"
9007 #~(symlink (string-append #$drv "/bin/bash")
9011 There are several things to note in the second version: the @code{store}
9012 parameter is now implicit and is ``threaded'' in the calls to the
9013 @code{package->derivation} and @code{gexp->derivation} monadic
9014 procedures, and the monadic value returned by @code{package->derivation}
9015 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
9017 As it turns out, the call to @code{package->derivation} can even be
9018 omitted since it will take place implicitly, as we will see later
9019 (@pxref{G-Expressions}):
9022 (define (sh-symlink)
9023 (gexp->derivation "sh"
9024 #~(symlink (string-append #$bash "/bin/bash")
9029 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
9030 @c for the funny quote.
9031 Calling the monadic @code{sh-symlink} has no effect. As someone once
9032 said, ``you exit a monad like you exit a building on fire: by running''.
9033 So, to exit the monad and get the desired effect, one must use
9034 @code{run-with-store}:
9037 (run-with-store (open-connection) (sh-symlink))
9038 @result{} /gnu/store/...-sh-symlink
9041 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
9042 new ``meta-commands'' to make it easier to deal with monadic procedures:
9043 @code{run-in-store}, and @code{enter-store-monad}. The former is used
9044 to ``run'' a single monadic value through the store:
9047 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
9048 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
9051 The latter enters a recursive REPL, where all the return values are
9052 automatically run through the store:
9055 scheme@@(guile-user)> ,enter-store-monad
9056 store-monad@@(guile-user) [1]> (package->derivation hello)
9057 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
9058 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
9059 $3 = "/gnu/store/@dots{}-foo"
9060 store-monad@@(guile-user) [1]> ,q
9061 scheme@@(guile-user)>
9065 Note that non-monadic values cannot be returned in the
9066 @code{store-monad} REPL.
9068 The main syntactic forms to deal with monads in general are provided by
9069 the @code{(guix monads)} module and are described below.
9071 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
9072 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
9076 @deffn {Scheme Syntax} return @var{val}
9077 Return a monadic value that encapsulates @var{val}.
9080 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
9081 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
9082 procedures @var{mproc}@dots{}@footnote{This operation is commonly
9083 referred to as ``bind'', but that name denotes an unrelated procedure in
9084 Guile. Thus we use this somewhat cryptic symbol inherited from the
9085 Haskell language.}. There can be one @var{mproc} or several of them, as
9090 (with-monad %state-monad
9092 (lambda (x) (return (+ 1 x)))
9093 (lambda (x) (return (* 2 x)))))
9097 @result{} some-state
9101 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
9103 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
9105 Bind the variables @var{var} to the monadic values @var{mval} in
9106 @var{body}, which is a sequence of expressions. As with the bind
9107 operator, this can be thought of as ``unpacking'' the raw, non-monadic
9108 value ``contained'' in @var{mval} and making @var{var} refer to that
9109 raw, non-monadic value within the scope of the @var{body}. The form
9110 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
9111 @var{val}, as per @code{let}. The binding operations occur in sequence
9112 from left to right. The last expression of @var{body} must be a monadic
9113 expression, and its result will become the result of the @code{mlet} or
9114 @code{mlet*} when run in the @var{monad}.
9116 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
9117 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
9120 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
9121 Bind @var{mexp} and the following monadic expressions in sequence,
9122 returning the result of the last expression. Every expression in the
9123 sequence must be a monadic expression.
9125 This is akin to @code{mlet}, except that the return values of the
9126 monadic expressions are ignored. In that sense, it is analogous to
9127 @code{begin}, but applied to monadic expressions.
9130 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
9131 When @var{condition} is true, evaluate the sequence of monadic
9132 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
9133 @var{condition} is false, return @code{*unspecified*} in the current
9134 monad. Every expression in the sequence must be a monadic expression.
9137 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
9138 When @var{condition} is false, evaluate the sequence of monadic
9139 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
9140 @var{condition} is true, return @code{*unspecified*} in the current
9141 monad. Every expression in the sequence must be a monadic expression.
9145 The @code{(guix monads)} module provides the @dfn{state monad}, which
9146 allows an additional value---the state---to be @emph{threaded} through
9147 monadic procedure calls.
9149 @defvr {Scheme Variable} %state-monad
9150 The state monad. Procedures in the state monad can access and change
9151 the state that is threaded.
9153 Consider the example below. The @code{square} procedure returns a value
9154 in the state monad. It returns the square of its argument, but also
9155 increments the current state value:
9159 (mlet %state-monad ((count (current-state)))
9160 (mbegin %state-monad
9161 (set-current-state (+ 1 count))
9164 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
9169 When ``run'' through @code{%state-monad}, we obtain that additional state
9170 value, which is the number of @code{square} calls.
9173 @deffn {Monadic Procedure} current-state
9174 Return the current state as a monadic value.
9177 @deffn {Monadic Procedure} set-current-state @var{value}
9178 Set the current state to @var{value} and return the previous state as a
9182 @deffn {Monadic Procedure} state-push @var{value}
9183 Push @var{value} to the current state, which is assumed to be a list,
9184 and return the previous state as a monadic value.
9187 @deffn {Monadic Procedure} state-pop
9188 Pop a value from the current state and return it as a monadic value.
9189 The state is assumed to be a list.
9192 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
9193 Run monadic value @var{mval} starting with @var{state} as the initial
9194 state. Return two values: the resulting value, and the resulting state.
9197 The main interface to the store monad, provided by the @code{(guix
9198 store)} module, is as follows.
9200 @defvr {Scheme Variable} %store-monad
9201 The store monad---an alias for @code{%state-monad}.
9203 Values in the store monad encapsulate accesses to the store. When its
9204 effect is needed, a value of the store monad must be ``evaluated'' by
9205 passing it to the @code{run-with-store} procedure (see below).
9208 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
9209 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
9210 open store connection.
9213 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
9214 Return as a monadic value the absolute file name in the store of the file
9215 containing @var{text}, a string. @var{references} is a list of store items that the
9216 resulting text file refers to; it defaults to the empty list.
9219 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
9220 Return as a monadic value the absolute file name in the store of the file
9221 containing @var{data}, a bytevector. @var{references} is a list of store
9222 items that the resulting binary file refers to; it defaults to the empty list.
9225 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
9226 [#:recursive? #t] [#:select? (const #t)]
9227 Return the name of @var{file} once interned in the store. Use
9228 @var{name} as its store name, or the basename of @var{file} if
9229 @var{name} is omitted.
9231 When @var{recursive?} is true, the contents of @var{file} are added
9232 recursively; if @var{file} designates a flat file and @var{recursive?}
9233 is true, its contents are added, and its permission bits are kept.
9235 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
9236 @var{stat})} for each directory entry, where @var{file} is the entry's
9237 absolute file name and @var{stat} is the result of @code{lstat}; exclude
9238 entries for which @var{select?} does not return true.
9240 The example below adds a file to the store, under two different names:
9243 (run-with-store (open-connection)
9244 (mlet %store-monad ((a (interned-file "README"))
9245 (b (interned-file "README" "LEGU-MIN")))
9246 (return (list a b))))
9248 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
9253 The @code{(guix packages)} module exports the following package-related
9256 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
9257 [#:system (%current-system)] [#:target #f] @
9260 value in the absolute file name of @var{file} within the @var{output}
9261 directory of @var{package}. When @var{file} is omitted, return the name
9262 of the @var{output} directory of @var{package}. When @var{target} is
9263 true, use it as a cross-compilation target triplet.
9265 Note that this procedure does @emph{not} build @var{package}. Thus, the
9266 result might or might not designate an existing file. We recommend not
9267 using this procedure unless you know what you are doing.
9270 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
9271 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
9272 @var{target} [@var{system}]
9273 Monadic version of @code{package-derivation} and
9274 @code{package-cross-derivation} (@pxref{Defining Packages}).
9279 @section G-Expressions
9281 @cindex G-expression
9282 @cindex build code quoting
9283 So we have ``derivations'', which represent a sequence of build actions
9284 to be performed to produce an item in the store (@pxref{Derivations}).
9285 These build actions are performed when asking the daemon to actually
9286 build the derivations; they are run by the daemon in a container
9287 (@pxref{Invoking guix-daemon}).
9289 @cindex code staging
9290 @cindex staging, of code
9291 @cindex strata of code
9292 It should come as no surprise that we like to write these build actions
9293 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
9294 code@footnote{The term @dfn{stratum} in this context was coined by
9295 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
9296 Kiselyov, who has written insightful
9297 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
9298 on this topic}, refers to this kind of code generation as
9299 @dfn{staging}.}: the ``host code''---code that defines packages, talks
9300 to the daemon, etc.---and the ``build code''---code that actually
9301 performs build actions, such as making directories, invoking
9302 @command{make}, and so on (@pxref{Build Phases}).
9304 To describe a derivation and its build actions, one typically needs to
9305 embed build code inside host code. It boils down to manipulating build
9306 code as data, and the homoiconicity of Scheme---code has a direct
9307 representation as data---comes in handy for that. But we need more than
9308 the normal @code{quasiquote} mechanism in Scheme to construct build
9311 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
9312 S-expressions adapted to build expressions. G-expressions, or
9313 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
9314 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
9315 @code{#$}, and @code{#$@@}), which are comparable to
9316 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
9317 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
9318 GNU Guile Reference Manual}). However, there are major differences:
9322 Gexps are meant to be written to a file and run or manipulated by other
9326 When a high-level object such as a package or derivation is unquoted
9327 inside a gexp, the result is as if its output file name had been
9331 Gexps carry information about the packages or derivations they refer to,
9332 and these dependencies are automatically added as inputs to the build
9333 processes that use them.
9336 @cindex lowering, of high-level objects in gexps
9337 This mechanism is not limited to package and derivation
9338 objects: @dfn{compilers} able to ``lower'' other high-level objects to
9339 derivations or files in the store can be defined,
9340 such that these objects can also be inserted
9341 into gexps. For example, a useful type of high-level objects that can be
9342 inserted in a gexp is ``file-like objects'', which make it easy to
9343 add files to the store and to refer to them in
9344 derivations and such (see @code{local-file} and @code{plain-file}
9347 To illustrate the idea, here is an example of a gexp:
9354 (symlink (string-append #$coreutils "/bin/ls")
9358 This gexp can be passed to @code{gexp->derivation}; we obtain a
9359 derivation that builds a directory containing exactly one symlink to
9360 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
9363 (gexp->derivation "the-thing" build-exp)
9366 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
9367 substituted to the reference to the @var{coreutils} package in the
9368 actual build code, and @var{coreutils} is automatically made an input to
9369 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
9370 output)}) is replaced by a string containing the directory name of the
9371 output of the derivation.
9373 @cindex cross compilation
9374 In a cross-compilation context, it is useful to distinguish between
9375 references to the @emph{native} build of a package---that can run on the
9376 host---versus references to cross builds of a package. To that end, the
9377 @code{#+} plays the same role as @code{#$}, but is a reference to a
9378 native package build:
9381 (gexp->derivation "vi"
9384 (mkdir (string-append #$output "/bin"))
9385 (system* (string-append #+coreutils "/bin/ln")
9387 (string-append #$emacs "/bin/emacs")
9388 (string-append #$output "/bin/vi")))
9389 #:target "aarch64-linux-gnu")
9393 In the example above, the native build of @var{coreutils} is used, so
9394 that @command{ln} can actually run on the host; but then the
9395 cross-compiled build of @var{emacs} is referenced.
9397 @cindex imported modules, for gexps
9398 @findex with-imported-modules
9399 Another gexp feature is @dfn{imported modules}: sometimes you want to be
9400 able to use certain Guile modules from the ``host environment'' in the
9401 gexp, so those modules should be imported in the ``build environment''.
9402 The @code{with-imported-modules} form allows you to express that:
9405 (let ((build (with-imported-modules '((guix build utils))
9407 (use-modules (guix build utils))
9408 (mkdir-p (string-append #$output "/bin"))))))
9409 (gexp->derivation "empty-dir"
9412 (display "success!\n")
9417 In this example, the @code{(guix build utils)} module is automatically
9418 pulled into the isolated build environment of our gexp, such that
9419 @code{(use-modules (guix build utils))} works as expected.
9421 @cindex module closure
9422 @findex source-module-closure
9423 Usually you want the @emph{closure} of the module to be imported---i.e.,
9424 the module itself and all the modules it depends on---rather than just
9425 the module; failing to do that, attempts to use the module will fail
9426 because of missing dependent modules. The @code{source-module-closure}
9427 procedure computes the closure of a module by looking at its source file
9428 headers, which comes in handy in this case:
9431 (use-modules (guix modules)) ;for 'source-module-closure'
9433 (with-imported-modules (source-module-closure
9434 '((guix build utils)
9436 (gexp->derivation "something-with-vms"
9438 (use-modules (guix build utils)
9443 @cindex extensions, for gexps
9444 @findex with-extensions
9445 In the same vein, sometimes you want to import not just pure-Scheme
9446 modules, but also ``extensions'' such as Guile bindings to C libraries
9447 or other ``full-blown'' packages. Say you need the @code{guile-json}
9448 package available on the build side, here's how you would do it:
9451 (use-modules (gnu packages guile)) ;for 'guile-json'
9453 (with-extensions (list guile-json)
9454 (gexp->derivation "something-with-json"
9456 (use-modules (json))
9460 The syntactic form to construct gexps is summarized below.
9462 @deffn {Scheme Syntax} #~@var{exp}
9463 @deffnx {Scheme Syntax} (gexp @var{exp})
9464 Return a G-expression containing @var{exp}. @var{exp} may contain one
9465 or more of the following forms:
9469 @itemx (ungexp @var{obj})
9470 Introduce a reference to @var{obj}. @var{obj} may have one of the
9471 supported types, for example a package or a
9472 derivation, in which case the @code{ungexp} form is replaced by its
9473 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
9475 If @var{obj} is a list, it is traversed and references to supported
9476 objects are substituted similarly.
9478 If @var{obj} is another gexp, its contents are inserted and its
9479 dependencies are added to those of the containing gexp.
9481 If @var{obj} is another kind of object, it is inserted as is.
9483 @item #$@var{obj}:@var{output}
9484 @itemx (ungexp @var{obj} @var{output})
9485 This is like the form above, but referring explicitly to the
9486 @var{output} of @var{obj}---this is useful when @var{obj} produces
9487 multiple outputs (@pxref{Packages with Multiple Outputs}).
9490 @itemx #+@var{obj}:output
9491 @itemx (ungexp-native @var{obj})
9492 @itemx (ungexp-native @var{obj} @var{output})
9493 Same as @code{ungexp}, but produces a reference to the @emph{native}
9494 build of @var{obj} when used in a cross compilation context.
9496 @item #$output[:@var{output}]
9497 @itemx (ungexp output [@var{output}])
9498 Insert a reference to derivation output @var{output}, or to the main
9499 output when @var{output} is omitted.
9501 This only makes sense for gexps passed to @code{gexp->derivation}.
9504 @itemx (ungexp-splicing @var{lst})
9505 Like the above, but splices the contents of @var{lst} inside the
9509 @itemx (ungexp-native-splicing @var{lst})
9510 Like the above, but refers to native builds of the objects listed in
9515 G-expressions created by @code{gexp} or @code{#~} are run-time objects
9516 of the @code{gexp?} type (see below).
9519 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
9520 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
9521 in their execution environment.
9523 Each item in @var{modules} can be the name of a module, such as
9524 @code{(guix build utils)}, or it can be a module name, followed by an
9525 arrow, followed by a file-like object:
9528 `((guix build utils)
9530 ((guix config) => ,(scheme-file "config.scm"
9531 #~(define-module @dots{}))))
9535 In the example above, the first two modules are taken from the search
9536 path, and the last one is created from the given file-like object.
9538 This form has @emph{lexical} scope: it has an effect on the gexps
9539 directly defined in @var{body}@dots{}, but not on those defined, say, in
9540 procedures called from @var{body}@dots{}.
9543 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
9544 Mark the gexps defined in @var{body}@dots{} as requiring
9545 @var{extensions} in their build and execution environment.
9546 @var{extensions} is typically a list of package objects such as those
9547 defined in the @code{(gnu packages guile)} module.
9549 Concretely, the packages listed in @var{extensions} are added to the
9550 load path while compiling imported modules in @var{body}@dots{}; they
9551 are also added to the load path of the gexp returned by
9555 @deffn {Scheme Procedure} gexp? @var{obj}
9556 Return @code{#t} if @var{obj} is a G-expression.
9559 G-expressions are meant to be written to disk, either as code building
9560 some derivation, or as plain files in the store. The monadic procedures
9561 below allow you to do that (@pxref{The Store Monad}, for more
9562 information about monads).
9564 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
9565 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
9566 [#:hash #f] [#:hash-algo #f] @
9567 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
9568 [#:module-path @code{%load-path}] @
9569 [#:effective-version "2.2"] @
9570 [#:references-graphs #f] [#:allowed-references #f] @
9571 [#:disallowed-references #f] @
9572 [#:leaked-env-vars #f] @
9573 [#:script-name (string-append @var{name} "-builder")] @
9574 [#:deprecation-warnings #f] @
9575 [#:local-build? #f] [#:substitutable? #t] @
9576 [#:properties '()] [#:guile-for-build #f]
9577 Return a derivation @var{name} that runs @var{exp} (a gexp) with
9578 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
9579 stored in a file called @var{script-name}. When @var{target} is true,
9580 it is used as the cross-compilation target triplet for packages referred
9583 @var{modules} is deprecated in favor of @code{with-imported-modules}.
9585 make @var{modules} available in the evaluation context of @var{exp};
9586 @var{modules} is a list of names of Guile modules searched in
9587 @var{module-path} to be copied in the store, compiled, and made available in
9588 the load path during the execution of @var{exp}---e.g., @code{((guix
9589 build utils) (guix build gnu-build-system))}.
9591 @var{effective-version} determines the string to use when adding extensions of
9592 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
9594 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
9597 When @var{references-graphs} is true, it must be a list of tuples of one of the
9601 (@var{file-name} @var{package})
9602 (@var{file-name} @var{package} @var{output})
9603 (@var{file-name} @var{derivation})
9604 (@var{file-name} @var{derivation} @var{output})
9605 (@var{file-name} @var{store-item})
9608 The right-hand-side of each element of @var{references-graphs} is automatically made
9609 an input of the build process of @var{exp}. In the build environment, each
9610 @var{file-name} contains the reference graph of the corresponding item, in a simple
9613 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
9614 In the latter case, the list denotes store items that the result is allowed to
9615 refer to. Any reference to another store item will lead to a build error.
9616 Similarly for @var{disallowed-references}, which can list items that must not be
9617 referenced by the outputs.
9619 @var{deprecation-warnings} determines whether to show deprecation warnings while
9620 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
9622 The other arguments are as for @code{derivation} (@pxref{Derivations}).
9625 @cindex file-like objects
9626 The @code{local-file}, @code{plain-file}, @code{computed-file},
9627 @code{program-file}, and @code{scheme-file} procedures below return
9628 @dfn{file-like objects}. That is, when unquoted in a G-expression,
9629 these objects lead to a file in the store. Consider this G-expression:
9632 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
9633 #$(local-file "/tmp/my-nscd.conf"))
9636 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
9637 to the store. Once expanded, for instance @i{via}
9638 @code{gexp->derivation}, the G-expression refers to that copy under
9639 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
9640 does not have any effect on what the G-expression does.
9641 @code{plain-file} can be used similarly; it differs in that the file
9642 content is directly passed as a string.
9644 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
9645 [#:recursive? #f] [#:select? (const #t)]
9646 Return an object representing local file @var{file} to add to the store;
9647 this object can be used in a gexp. If @var{file} is a literal string
9648 denoting a relative file name, it is looked up relative to the source
9649 file where it appears; if @var{file} is not a literal string, it is
9650 looked up relative to the current working directory at run time.
9651 @var{file} will be added to the store under @var{name}--by default the
9652 base name of @var{file}.
9654 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
9655 designates a flat file and @var{recursive?} is true, its contents are added, and its
9656 permission bits are kept.
9658 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
9659 @var{stat})} for each directory entry, where @var{file} is the entry's
9660 absolute file name and @var{stat} is the result of @code{lstat}; exclude
9661 entries for which @var{select?} does not return true.
9663 This is the declarative counterpart of the @code{interned-file} monadic
9664 procedure (@pxref{The Store Monad, @code{interned-file}}).
9667 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
9668 Return an object representing a text file called @var{name} with the given
9669 @var{content} (a string or a bytevector) to be added to the store.
9671 This is the declarative counterpart of @code{text-file}.
9674 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
9677 Return an object representing the store item @var{name}, a file or
9678 directory computed by @var{gexp}. When @var{local-build?} is true (the
9679 default), the derivation is built locally. @var{options} is a list of
9680 additional arguments to pass to @code{gexp->derivation}.
9682 This is the declarative counterpart of @code{gexp->derivation}.
9685 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
9686 [#:guile (default-guile)] [#:module-path %load-path] @
9687 [#:system (%current-system)] [#:target #f]
9688 Return an executable script @var{name} that runs @var{exp} using
9689 @var{guile}, with @var{exp}'s imported modules in its search path.
9690 Look up @var{exp}'s modules in @var{module-path}.
9692 The example below builds a script that simply invokes the @command{ls}
9696 (use-modules (guix gexp) (gnu packages base))
9698 (gexp->script "list-files"
9699 #~(execl #$(file-append coreutils "/bin/ls")
9703 When ``running'' it through the store (@pxref{The Store Monad,
9704 @code{run-with-store}}), we obtain a derivation that produces an
9705 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
9708 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
9710 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
9714 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
9715 [#:guile #f] [#:module-path %load-path]
9716 Return an object representing the executable store item @var{name} that
9717 runs @var{gexp}. @var{guile} is the Guile package used to execute that
9718 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
9720 This is the declarative counterpart of @code{gexp->script}.
9723 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
9724 [#:set-load-path? #t] [#:module-path %load-path] @
9726 [#:guile (default-guile)]
9727 Return a derivation that builds a file @var{name} containing @var{exp}.
9728 When @var{splice?} is true, @var{exp} is considered to be a list of
9729 expressions that will be spliced in the resulting file.
9731 When @var{set-load-path?} is true, emit code in the resulting file to
9732 set @code{%load-path} and @code{%load-compiled-path} to honor
9733 @var{exp}'s imported modules. Look up @var{exp}'s modules in
9736 The resulting file holds references to all the dependencies of @var{exp}
9737 or a subset thereof.
9740 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} @
9741 [#:splice? #f] [#:set-load-path? #t]
9742 Return an object representing the Scheme file @var{name} that contains
9745 This is the declarative counterpart of @code{gexp->file}.
9748 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
9749 Return as a monadic value a derivation that builds a text file
9750 containing all of @var{text}. @var{text} may list, in addition to
9751 strings, objects of any type that can be used in a gexp: packages,
9752 derivations, local file objects, etc. The resulting store file holds
9753 references to all these.
9755 This variant should be preferred over @code{text-file} anytime the file
9756 to create will reference items from the store. This is typically the
9757 case when building a configuration file that embeds store file names,
9761 (define (profile.sh)
9762 ;; Return the name of a shell script in the store that
9763 ;; initializes the 'PATH' environment variable.
9764 (text-file* "profile.sh"
9765 "export PATH=" coreutils "/bin:"
9766 grep "/bin:" sed "/bin\n"))
9769 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
9770 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
9771 preventing them from being garbage-collected during its lifetime.
9774 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
9775 Return an object representing store file @var{name} containing
9776 @var{text}. @var{text} is a sequence of strings and file-like objects,
9780 (mixed-text-file "profile"
9781 "export PATH=" coreutils "/bin:" grep "/bin")
9784 This is the declarative counterpart of @code{text-file*}.
9787 @deffn {Scheme Procedure} file-union @var{name} @var{files}
9788 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
9789 Each item in @var{files} must be a two-element list where the first element is the
9790 file name to use in the new directory, and the second element is a gexp
9791 denoting the target file. Here's an example:
9795 `(("hosts" ,(plain-file "hosts"
9796 "127.0.0.1 localhost"))
9797 ("bashrc" ,(plain-file "bashrc"
9798 "alias ls='ls --color=auto'"))))
9801 This yields an @code{etc} directory containing these two files.
9804 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
9805 Return a directory that is the union of @var{things}, where @var{things} is a list of
9806 file-like objects denoting directories. For example:
9809 (directory-union "guile+emacs" (list guile emacs))
9812 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
9815 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
9816 Return a file-like object that expands to the concatenation of @var{obj}
9817 and @var{suffix}, where @var{obj} is a lowerable object and each
9818 @var{suffix} is a string.
9820 As an example, consider this gexp:
9823 (gexp->script "run-uname"
9824 #~(system* #$(file-append coreutils
9828 The same effect could be achieved with:
9831 (gexp->script "run-uname"
9832 #~(system* (string-append #$coreutils
9836 There is one difference though: in the @code{file-append} case, the
9837 resulting script contains the absolute file name as a string, whereas in
9838 the second case, the resulting script contains a @code{(string-append
9839 @dots{})} expression to construct the file name @emph{at run time}.
9842 @deffn {Scheme Syntax} let-system @var{system} @var{body}@dots{}
9843 @deffnx {Scheme Syntax} let-system (@var{system} @var{target}) @var{body}@dots{}
9844 Bind @var{system} to the currently targeted system---e.g.,
9845 @code{"x86_64-linux"}---within @var{body}.
9847 In the second case, additionally bind @var{target} to the current
9848 cross-compilation target---a GNU triplet such as
9849 @code{"arm-linux-gnueabihf"}---or @code{#f} if we are not
9852 @code{let-system} is useful in the occasional case where the object
9853 spliced into the gexp depends on the target system, as in this example:
9857 #+(let-system system
9858 (cond ((string-prefix? "armhf-" system)
9859 (file-append qemu "/bin/qemu-system-arm"))
9860 ((string-prefix? "x86_64-" system)
9861 (file-append qemu "/bin/qemu-system-x86_64"))
9864 "-net" "user" #$image)
9868 @deffn {Scheme Syntax} with-parameters ((@var{parameter} @var{value}) @dots{}) @var{exp}
9869 This macro is similar to the @code{parameterize} form for
9870 dynamically-bound @dfn{parameters} (@pxref{Parameters,,, guile, GNU
9871 Guile Reference Manual}). The key difference is that it takes effect
9872 when the file-like object returned by @var{exp} is lowered to a
9873 derivation or store item.
9875 A typical use of @code{with-parameters} is to force the system in effect
9879 (with-parameters ((%current-system "i686-linux"))
9883 The example above returns an object that corresponds to the i686 build
9884 of Coreutils, regardless of the current value of @code{%current-system}.
9888 Of course, in addition to gexps embedded in ``host'' code, there are
9889 also modules containing build tools. To make it clear that they are
9890 meant to be used in the build stratum, these modules are kept in the
9891 @code{(guix build @dots{})} name space.
9893 @cindex lowering, of high-level objects in gexps
9894 Internally, high-level objects are @dfn{lowered}, using their compiler,
9895 to either derivations or store items. For instance, lowering a package
9896 yields a derivation, and lowering a @code{plain-file} yields a store
9897 item. This is achieved using the @code{lower-object} monadic procedure.
9899 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
9901 Return as a value in @code{%store-monad} the derivation or store item
9902 corresponding to @var{obj} for @var{system}, cross-compiling for
9903 @var{target} if @var{target} is true. @var{obj} must be an object that
9904 has an associated gexp compiler, such as a @code{<package>}.
9907 @node Invoking guix repl
9908 @section Invoking @command{guix repl}
9910 @cindex REPL, read-eval-print loop, script
9911 The @command{guix repl} command makes it easier to program Guix in Guile
9912 by launching a Guile @dfn{read-eval-print loop} (REPL) for interactive
9913 programming (@pxref{Using Guile Interactively,,, guile,
9914 GNU Guile Reference Manual}), or by running Guile scripts
9915 (@pxref{Running Guile Scripts,,, guile,
9916 GNU Guile Reference Manual}).
9917 Compared to just launching the @command{guile}
9918 command, @command{guix repl} guarantees that all the Guix modules and all its
9919 dependencies are available in the search path.
9921 The general syntax is:
9924 guix repl @var{options} [@var{file} @var{args}]
9927 When a @var{file} argument is provided, @var{file} is
9928 executed as a Guile scripts:
9931 guix repl my-script.scm
9934 To pass arguments to the script, use @code{--} to prevent them from
9935 being interpreted as arguments to @command{guix repl} itself:
9938 guix repl -- my-script.scm --input=foo.txt
9941 To make a script executable directly from the shell, using the guix
9942 executable that is on the user's search path, add the following two
9943 lines at the top of the script:
9946 @code{#!/usr/bin/env -S guix repl --}
9950 Without a file name argument, a Guile REPL is started:
9954 scheme@@(guile-user)> ,use (gnu packages base)
9955 scheme@@(guile-user)> coreutils
9956 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
9960 In addition, @command{guix repl} implements a simple machine-readable REPL
9961 protocol for use by @code{(guix inferior)}, a facility to interact with
9962 @dfn{inferiors}, separate processes running a potentially different revision
9965 The available options are as follows:
9968 @item --type=@var{type}
9969 @itemx -t @var{type}
9970 Start a REPL of the given @var{TYPE}, which can be one of the following:
9974 This is default, and it spawns a standard full-featured Guile REPL.
9976 Spawn a REPL that uses the machine-readable protocol. This is the protocol
9977 that the @code{(guix inferior)} module speaks.
9980 @item --listen=@var{endpoint}
9981 By default, @command{guix repl} reads from standard input and writes to
9982 standard output. When this option is passed, it will instead listen for
9983 connections on @var{endpoint}. Here are examples of valid options:
9986 @item --listen=tcp:37146
9987 Accept connections on localhost on port 37146.
9989 @item --listen=unix:/tmp/socket
9990 Accept connections on the Unix-domain socket @file{/tmp/socket}.
9993 @item --load-path=@var{directory}
9994 @itemx -L @var{directory}
9995 Add @var{directory} to the front of the package module search path
9996 (@pxref{Package Modules}).
9998 This allows users to define their own packages and make them visible to
10002 Inhibit loading of the @file{~/.guile} file. By default, that
10003 configuration file is loaded when spawning a @code{guile} REPL.
10006 @c *********************************************************************
10010 This section describes Guix command-line utilities. Some of them are
10011 primarily targeted at developers and users who write new package
10012 definitions, while others are more generally useful. They complement
10013 the Scheme programming interface of Guix in a convenient way.
10016 * Invoking guix build:: Building packages from the command line.
10017 * Invoking guix edit:: Editing package definitions.
10018 * Invoking guix download:: Downloading a file and printing its hash.
10019 * Invoking guix hash:: Computing the cryptographic hash of a file.
10020 * Invoking guix import:: Importing package definitions.
10021 * Invoking guix refresh:: Updating package definitions.
10022 * Invoking guix lint:: Finding errors in package definitions.
10023 * Invoking guix size:: Profiling disk usage.
10024 * Invoking guix graph:: Visualizing the graph of packages.
10025 * Invoking guix publish:: Sharing substitutes.
10026 * Invoking guix challenge:: Challenging substitute servers.
10027 * Invoking guix copy:: Copying to and from a remote store.
10028 * Invoking guix container:: Process isolation.
10029 * Invoking guix weather:: Assessing substitute availability.
10030 * Invoking guix processes:: Listing client processes.
10033 @node Invoking guix build
10034 @section Invoking @command{guix build}
10036 @cindex package building
10037 @cindex @command{guix build}
10038 The @command{guix build} command builds packages or derivations and
10039 their dependencies, and prints the resulting store paths. Note that it
10040 does not modify the user's profile---this is the job of the
10041 @command{guix package} command (@pxref{Invoking guix package}). Thus,
10042 it is mainly useful for distribution developers.
10044 The general syntax is:
10047 guix build @var{options} @var{package-or-derivation}@dots{}
10050 As an example, the following command builds the latest versions of Emacs
10051 and of Guile, displays their build logs, and finally displays the
10052 resulting directories:
10055 guix build emacs guile
10058 Similarly, the following command builds all the available packages:
10061 guix build --quiet --keep-going \
10062 `guix package -A | cut -f1,2 --output-delimiter=@@`
10065 @var{package-or-derivation} may be either the name of a package found in
10066 the software distribution such as @code{coreutils} or
10067 @code{coreutils@@8.20}, or a derivation such as
10068 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
10069 package with the corresponding name (and optionally version) is searched
10070 for among the GNU distribution modules (@pxref{Package Modules}).
10072 Alternatively, the @option{--expression} option may be used to specify a
10073 Scheme expression that evaluates to a package; this is useful when
10074 disambiguating among several same-named packages or package variants is
10077 There may be zero or more @var{options}. The available options are
10078 described in the subsections below.
10081 * Common Build Options:: Build options for most commands.
10082 * Package Transformation Options:: Creating variants of packages.
10083 * Additional Build Options:: Options specific to 'guix build'.
10084 * Debugging Build Failures:: Real life packaging experience.
10087 @node Common Build Options
10088 @subsection Common Build Options
10090 A number of options that control the build process are common to
10091 @command{guix build} and other commands that can spawn builds, such as
10092 @command{guix package} or @command{guix archive}. These are the
10097 @item --load-path=@var{directory}
10098 @itemx -L @var{directory}
10099 Add @var{directory} to the front of the package module search path
10100 (@pxref{Package Modules}).
10102 This allows users to define their own packages and make them visible to
10103 the command-line tools.
10105 @item --keep-failed
10107 Keep the build tree of failed builds. Thus, if a build fails, its build
10108 tree is kept under @file{/tmp}, in a directory whose name is shown at
10109 the end of the build log. This is useful when debugging build issues.
10110 @xref{Debugging Build Failures}, for tips and tricks on how to debug
10113 This option implies @option{--no-offload}, and it has no effect when
10114 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
10115 Store, the @env{GUIX_DAEMON_SOCKET} variable}).
10119 Keep going when some of the derivations fail to build; return only once
10120 all the builds have either completed or failed.
10122 The default behavior is to stop as soon as one of the specified
10123 derivations has failed.
10127 Do not build the derivations.
10129 @anchor{fallback-option}
10131 When substituting a pre-built binary fails, fall back to building
10132 packages locally (@pxref{Substitution Failure}).
10134 @item --substitute-urls=@var{urls}
10135 @anchor{client-substitute-urls}
10136 Consider @var{urls} the whitespace-separated list of substitute source
10137 URLs, overriding the default list of URLs of @command{guix-daemon}
10138 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
10140 This means that substitutes may be downloaded from @var{urls}, provided
10141 they are signed by a key authorized by the system administrator
10142 (@pxref{Substitutes}).
10144 When @var{urls} is the empty string, substitutes are effectively
10147 @item --no-substitutes
10148 Do not use substitutes for build products. That is, always build things
10149 locally instead of allowing downloads of pre-built binaries
10150 (@pxref{Substitutes}).
10153 Do not ``graft'' packages. In practice, this means that package updates
10154 available as grafts are not applied. @xref{Security Updates}, for more
10155 information on grafts.
10157 @item --rounds=@var{n}
10158 Build each derivation @var{n} times in a row, and raise an error if
10159 consecutive build results are not bit-for-bit identical.
10161 This is a useful way to detect non-deterministic builds processes.
10162 Non-deterministic build processes are a problem because they make it
10163 practically impossible for users to @emph{verify} whether third-party
10164 binaries are genuine. @xref{Invoking guix challenge}, for more.
10166 When used in conjunction with @option{--keep-failed}, the differing
10167 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
10168 This makes it easy to look for differences between the two results.
10171 Do not use offload builds to other machines (@pxref{Daemon Offload
10172 Setup}). That is, always build things locally instead of offloading
10173 builds to remote machines.
10175 @item --max-silent-time=@var{seconds}
10176 When the build or substitution process remains silent for more than
10177 @var{seconds}, terminate it and report a build failure.
10179 By default, the daemon's setting is honored (@pxref{Invoking
10180 guix-daemon, @option{--max-silent-time}}).
10182 @item --timeout=@var{seconds}
10183 Likewise, when the build or substitution process lasts for more than
10184 @var{seconds}, terminate it and report a build failure.
10186 By default, the daemon's setting is honored (@pxref{Invoking
10187 guix-daemon, @option{--timeout}}).
10189 @c Note: This option is actually not part of %standard-build-options but
10190 @c most programs honor it.
10191 @cindex verbosity, of the command-line tools
10192 @cindex build logs, verbosity
10193 @item -v @var{level}
10194 @itemx --verbosity=@var{level}
10195 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
10196 output is produced, 1 is for quiet output, and 2 shows all the build log
10197 output on standard error.
10199 @item --cores=@var{n}
10201 Allow the use of up to @var{n} CPU cores for the build. The special
10202 value @code{0} means to use as many CPU cores as available.
10204 @item --max-jobs=@var{n}
10206 Allow at most @var{n} build jobs in parallel. @xref{Invoking
10207 guix-daemon, @option{--max-jobs}}, for details about this option and the
10208 equivalent @command{guix-daemon} option.
10210 @item --debug=@var{level}
10211 Produce debugging output coming from the build daemon. @var{level} must be an
10212 integer between 0 and 5; higher means more verbose output. Setting a level of
10213 4 or more may be helpful when debugging setup issues with the build daemon.
10217 Behind the scenes, @command{guix build} is essentially an interface to
10218 the @code{package-derivation} procedure of the @code{(guix packages)}
10219 module, and to the @code{build-derivations} procedure of the @code{(guix
10220 derivations)} module.
10222 In addition to options explicitly passed on the command line,
10223 @command{guix build} and other @command{guix} commands that support
10224 building honor the @env{GUIX_BUILD_OPTIONS} environment variable.
10226 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
10227 Users can define this variable to a list of command line options that
10228 will automatically be used by @command{guix build} and other
10229 @command{guix} commands that can perform builds, as in the example
10233 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
10236 These options are parsed independently, and the result is appended to
10237 the parsed command-line options.
10241 @node Package Transformation Options
10242 @subsection Package Transformation Options
10244 @cindex package variants
10245 Another set of command-line options supported by @command{guix build}
10246 and also @command{guix package} are @dfn{package transformation
10247 options}. These are options that make it possible to define @dfn{package
10248 variants}---for instance, packages built from different source code.
10249 This is a convenient way to create customized packages on the fly
10250 without having to type in the definitions of package variants
10251 (@pxref{Defining Packages}).
10253 Package transformation options are preserved across upgrades:
10254 @command{guix upgrade} attempts to apply transformation options
10255 initially used when creating the profile to the upgraded packages.
10257 The available options are listed below. Most commands support them and
10258 also support a @option{--help-transform} option that lists all the
10259 available options and a synopsis (these options are not shown in the
10260 @option{--help} output for brevity).
10264 @item --with-source=@var{source}
10265 @itemx --with-source=@var{package}=@var{source}
10266 @itemx --with-source=@var{package}@@@var{version}=@var{source}
10267 Use @var{source} as the source of @var{package}, and @var{version} as
10268 its version number.
10269 @var{source} must be a file name or a URL, as for @command{guix
10270 download} (@pxref{Invoking guix download}).
10272 When @var{package} is omitted,
10273 it is taken to be the package name specified on the
10274 command line that matches the base of @var{source}---e.g.,
10275 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
10276 package is @code{guile}.
10278 Likewise, when @var{version} is omitted, the version string is inferred from
10279 @var{source}; in the previous example, it is @code{2.0.10}.
10281 This option allows users to try out versions of packages other than the
10282 one provided by the distribution. The example below downloads
10283 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
10284 the @code{ed} package:
10287 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
10290 As a developer, @option{--with-source} makes it easy to test release
10294 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
10297 @dots{} or to build from a checkout in a pristine environment:
10300 $ git clone git://git.sv.gnu.org/guix.git
10301 $ guix build guix --with-source=guix@@1.0=./guix
10304 @item --with-input=@var{package}=@var{replacement}
10305 Replace dependency on @var{package} by a dependency on
10306 @var{replacement}. @var{package} must be a package name, and
10307 @var{replacement} must be a package specification such as @code{guile}
10308 or @code{guile@@1.8}.
10310 For instance, the following command builds Guix, but replaces its
10311 dependency on the current stable version of Guile with a dependency on
10312 the legacy version of Guile, @code{guile@@2.0}:
10315 guix build --with-input=guile=guile@@2.0 guix
10318 This is a recursive, deep replacement. So in this example, both
10319 @code{guix} and its dependency @code{guile-json} (which also depends on
10320 @code{guile}) get rebuilt against @code{guile@@2.0}.
10322 This is implemented using the @code{package-input-rewriting} Scheme
10323 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
10325 @item --with-graft=@var{package}=@var{replacement}
10326 This is similar to @option{--with-input} but with an important difference:
10327 instead of rebuilding the whole dependency chain, @var{replacement} is
10328 built and then @dfn{grafted} onto the binaries that were initially
10329 referring to @var{package}. @xref{Security Updates}, for more
10330 information on grafts.
10332 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
10333 and all its dependencies, replacing references to the version of GnuTLS
10334 they currently refer to:
10337 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
10340 This has the advantage of being much faster than rebuilding everything.
10341 But there is a caveat: it works if and only if @var{package} and
10342 @var{replacement} are strictly compatible---for example, if they provide
10343 a library, the application binary interface (ABI) of those libraries
10344 must be compatible. If @var{replacement} is somehow incompatible with
10345 @var{package}, then the resulting package may be unusable. Use with
10348 @cindex debugging info, rebuilding
10349 @item --with-debug-info=@var{package}
10350 Build @var{package} in a way that preserves its debugging info and graft
10351 it onto packages that depend on it. This is useful if @var{package}
10352 does not already provide debugging info as a @code{debug} output
10353 (@pxref{Installing Debugging Files}).
10355 For example, suppose you're experiencing a crash in Inkscape and would
10356 like to see what's up in GLib, a library deep down in Inkscape's
10357 dependency graph. GLib lacks a @code{debug} output, so debugging is
10358 tough. Fortunately, you rebuild GLib with debugging info and tack it on
10362 guix install inkscape --with-debug-info=glib
10365 Only GLib needs to be recompiled so this takes a reasonable amount of
10366 time. @xref{Installing Debugging Files}, for more info.
10369 Under the hood, this option works by passing the @samp{#:strip-binaries?
10370 #f} to the build system of the package of interest (@pxref{Build
10371 Systems}). Most build systems support that option but some do not. In
10372 that case, an error is raised.
10374 Likewise, if a C/C++ package is built without @code{-g} (which is rarely
10375 the case), debugging info will remain unavailable even when
10376 @code{#:strip-binaries?} is false.
10379 @cindex tool chain, changing the build tool chain of a package
10380 @item --with-c-toolchain=@var{package}=@var{toolchain}
10381 This option changes the compilation of @var{package} and everything that
10382 depends on it so that they get built with @var{toolchain} instead of the
10383 default GNU tool chain for C/C++.
10385 Consider this example:
10388 guix build octave-cli \
10389 --with-c-toolchain=fftw=gcc-toolchain@@10 \
10390 --with-c-toolchain=fftwf=gcc-toolchain@@10
10393 The command above builds a variant of the @code{fftw} and @code{fftwf}
10394 packages using version 10 of @code{gcc-toolchain} instead of the default
10395 tool chain, and then builds a variant of the GNU@tie{}Octave
10396 command-line interface using them. GNU@tie{}Octave itself is also built
10397 with @code{gcc-toolchain@@10}.
10399 This other example builds the Hardware Locality (@code{hwloc}) library
10400 and its dependents up to @code{intel-mpi-benchmarks} with the Clang C
10404 guix build --with-c-toolchain=hwloc=clang-toolchain \
10405 intel-mpi-benchmarks
10409 There can be application binary interface (ABI) incompatibilities among
10410 tool chains. This is particularly true of the C++ standard library and
10411 run-time support libraries such as that of OpenMP@. By rebuilding all
10412 dependents with the same tool chain, @option{--with-c-toolchain} minimizes
10413 the risks of incompatibility but cannot entirely eliminate them. Choose
10414 @var{package} wisely.
10417 @item --with-git-url=@var{package}=@var{url}
10418 @cindex Git, using the latest commit
10419 @cindex latest commit, building
10420 Build @var{package} from the latest commit of the @code{master} branch of the
10421 Git repository at @var{url}. Git sub-modules of the repository are fetched,
10424 For example, the following command builds the NumPy Python library against the
10425 latest commit of the master branch of Python itself:
10428 guix build python-numpy \
10429 --with-git-url=python=https://github.com/python/cpython
10432 This option can also be combined with @option{--with-branch} or
10433 @option{--with-commit} (see below).
10435 @cindex continuous integration
10436 Obviously, since it uses the latest commit of the given branch, the result of
10437 such a command varies over time. Nevertheless it is a convenient way to
10438 rebuild entire software stacks against the latest commit of one or more
10439 packages. This is particularly useful in the context of continuous
10442 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
10443 consecutive accesses to the same repository. You may want to clean it up once
10444 in a while to save disk space.
10446 @item --with-branch=@var{package}=@var{branch}
10447 Build @var{package} from the latest commit of @var{branch}. If the
10448 @code{source} field of @var{package} is an origin with the @code{git-fetch}
10449 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
10450 repository URL is taken from that @code{source}. Otherwise you have to use
10451 @option{--with-git-url} to specify the URL of the Git repository.
10453 For instance, the following command builds @code{guile-sqlite3} from the
10454 latest commit of its @code{master} branch, and then builds @code{guix} (which
10455 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
10456 specific @code{guile-sqlite3} build:
10459 guix build --with-branch=guile-sqlite3=master cuirass
10462 @item --with-commit=@var{package}=@var{commit}
10463 This is similar to @option{--with-branch}, except that it builds from
10464 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
10465 Git commit SHA1 identifier or a tag.
10467 @item --with-patch=@var{package}=@var{file}
10468 Add @var{file} to the list of patches applied to @var{package}, where
10469 @var{package} is a spec such as @code{python@@3.8} or @code{glibc}.
10470 @var{file} must contain a patch; it is applied with the flags specified
10471 in the @code{origin} of @var{package} (@pxref{origin Reference}), which
10472 by default includes @code{-p1} (@pxref{patch Directories,,, diffutils,
10473 Comparing and Merging Files}).
10475 As an example, the command below rebuilds Coreutils with the GNU C
10476 Library (glibc) patched with the given patch:
10479 guix build coreutils --with-patch=glibc=./glibc-frob.patch
10482 In this example, glibc itself as well as everything that leads to
10483 Coreutils in the dependency graph is rebuilt.
10485 @cindex upstream, latest version
10486 @item --with-latest=@var{package}
10487 So you like living on the bleeding edge? This option is for you! It
10488 replaces occurrences of @var{package} in the dependency graph with its
10489 latest upstream version, as reported by @command{guix refresh}
10490 (@pxref{Invoking guix refresh}).
10492 It does so by determining the latest upstream release of @var{package}
10493 (if possible), downloading it, and authenticating it @emph{if} it comes
10494 with an OpenPGP signature.
10496 As an example, the command below builds Guix against the latest version
10500 guix build guix --with-latest=guile-json
10503 There are limitations. First, in cases where the tool cannot or does
10504 not know how to authenticate source code, you are at risk of running
10505 malicious code; a warning is emitted in this case. Second, this option
10506 simply changes the source used in the existing package definitions,
10507 which is not always sufficient: there might be additional dependencies
10508 that need to be added, patches to apply, and more generally the quality
10509 assurance work that Guix developers normally do will be missing.
10511 You've been warned! In all the other cases, it's a snappy way to stay
10512 on top. We encourage you to submit patches updating the actual package
10513 definitions once you have successfully tested an upgrade
10514 (@pxref{Contributing}).
10516 @cindex test suite, skipping
10517 @item --without-tests=@var{package}
10518 Build @var{package} without running its tests. This can be useful in
10519 situations where you want to skip the lengthy test suite of a
10520 intermediate package, or if a package's test suite fails in a
10521 non-deterministic fashion. It should be used with care because running
10522 the test suite is a good way to ensure a package is working as intended.
10524 Turning off tests leads to a different store item. Consequently, when
10525 using this option, anything that depends on @var{package} must be
10526 rebuilt, as in this example:
10529 guix install --without-tests=python python-notebook
10532 The command above installs @code{python-notebook} on top of
10533 @code{python} built without running its test suite. To do so, it also
10534 rebuilds everything that depends on @code{python}, including
10535 @code{python-notebook} itself.
10537 Internally, @option{--without-tests} relies on changing the
10538 @code{#:tests?} option of a package's @code{check} phase (@pxref{Build
10539 Systems}). Note that some packages use a customized @code{check} phase
10540 that does not respect a @code{#:tests? #f} setting. Therefore,
10541 @option{--without-tests} has no effect on these packages.
10545 Wondering how to achieve the same effect using Scheme code, for example
10546 in your manifest, or how to write your own package transformation?
10547 @xref{Defining Package Variants}, for an overview of the programming
10548 interfaces available.
10550 @node Additional Build Options
10551 @subsection Additional Build Options
10553 The command-line options presented below are specific to @command{guix
10560 Build quietly, without displaying the build log; this is equivalent to
10561 @option{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
10562 (or similar) and can always be retrieved using the @option{--log-file} option.
10564 @item --file=@var{file}
10565 @itemx -f @var{file}
10566 Build the package, derivation, or other file-like object that the code within
10567 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
10569 As an example, @var{file} might contain a package definition like this
10570 (@pxref{Defining Packages}):
10573 @include package-hello.scm
10576 The @var{file} may also contain a JSON representation of one or more
10577 package definitions. Running @code{guix build -f} on @file{hello.json}
10578 with the following contents would result in building the packages
10579 @code{myhello} and @code{greeter}:
10582 @verbatiminclude package-hello.json
10585 @item --manifest=@var{manifest}
10586 @itemx -m @var{manifest}
10587 Build all packages listed in the given @var{manifest}
10588 (@pxref{profile-manifest, @option{--manifest}}).
10590 @item --expression=@var{expr}
10591 @itemx -e @var{expr}
10592 Build the package or derivation @var{expr} evaluates to.
10594 For example, @var{expr} may be @code{(@@ (gnu packages guile)
10595 guile-1.8)}, which unambiguously designates this specific variant of
10596 version 1.8 of Guile.
10598 Alternatively, @var{expr} may be a G-expression, in which case it is used
10599 as a build program passed to @code{gexp->derivation}
10600 (@pxref{G-Expressions}).
10602 Lastly, @var{expr} may refer to a zero-argument monadic procedure
10603 (@pxref{The Store Monad}). The procedure must return a derivation as a
10604 monadic value, which is then passed through @code{run-with-store}.
10608 Build the source derivations of the packages, rather than the packages
10611 For instance, @code{guix build -S gcc} returns something like
10612 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
10615 The returned source tarball is the result of applying any patches and
10616 code snippets specified in the package @code{origin} (@pxref{Defining
10619 @cindex source, verification
10620 As with other derivations, the result of building a source derivation
10621 can be verified using the @option{--check} option (@pxref{build-check}).
10622 This is useful to validate that a (potentially already built or
10623 substituted, thus cached) package source matches against its declared
10626 Note that @command{guix build -S} compiles the sources only of the
10627 specified packages. They do not include the sources of statically
10628 linked dependencies and by themselves are insufficient for reproducing
10632 Fetch and return the source of @var{package-or-derivation} and all their
10633 dependencies, recursively. This is a handy way to obtain a local copy
10634 of all the source code needed to build @var{packages}, allowing you to
10635 eventually build them even without network access. It is an extension
10636 of the @option{--source} option and can accept one of the following
10637 optional argument values:
10641 This value causes the @option{--sources} option to behave in the same way
10642 as the @option{--source} option.
10645 Build the source derivations of all packages, including any source that
10646 might be listed as @code{inputs}. This is the default value.
10649 $ guix build --sources tzdata
10650 The following derivations will be built:
10651 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
10652 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
10656 Build the source derivations of all packages, as well of all transitive
10657 inputs to the packages. This can be used e.g.@: to
10658 prefetch package source for later offline building.
10661 $ guix build --sources=transitive tzdata
10662 The following derivations will be built:
10663 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
10664 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
10665 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
10666 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
10667 /gnu/store/@dots{}-make-4.1.tar.xz.drv
10668 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
10674 @item --system=@var{system}
10675 @itemx -s @var{system}
10676 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
10677 the system type of the build host. The @command{guix build} command allows
10678 you to repeat this option several times, in which case it builds for all the
10679 specified systems; other commands ignore extraneous @option{-s} options.
10682 The @option{--system} flag is for @emph{native} compilation and must not
10683 be confused with cross-compilation. See @option{--target} below for
10684 information on cross-compilation.
10687 An example use of this is on Linux-based systems, which can emulate
10688 different personalities. For instance, passing
10689 @option{--system=i686-linux} on an @code{x86_64-linux} system or
10690 @option{--system=armhf-linux} on an @code{aarch64-linux} system allows
10691 you to build packages in a complete 32-bit environment.
10694 Building for an @code{armhf-linux} system is unconditionally enabled on
10695 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
10696 allow for this functionality, notably the ThunderX.
10699 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
10700 is enabled (@pxref{Virtualization Services,
10701 @code{qemu-binfmt-service-type}}), you can build for any system for
10702 which a QEMU @code{binfmt_misc} handler is installed.
10704 Builds for a system other than that of the machine you are using can
10705 also be offloaded to a remote machine of the right architecture.
10706 @xref{Daemon Offload Setup}, for more information on offloading.
10708 @item --target=@var{triplet}
10709 @cindex cross-compilation
10710 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
10711 as @code{"aarch64-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
10712 configuration triplets,, autoconf, Autoconf}).
10714 @anchor{build-check}
10716 @cindex determinism, checking
10717 @cindex reproducibility, checking
10718 Rebuild @var{package-or-derivation}, which are already available in the
10719 store, and raise an error if the build results are not bit-for-bit
10722 This mechanism allows you to check whether previously installed
10723 substitutes are genuine (@pxref{Substitutes}), or whether the build result
10724 of a package is deterministic. @xref{Invoking guix challenge}, for more
10725 background information and tools.
10727 When used in conjunction with @option{--keep-failed}, the differing
10728 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
10729 This makes it easy to look for differences between the two results.
10732 @cindex repairing store items
10733 @cindex corruption, recovering from
10734 Attempt to repair the specified store items, if they are corrupt, by
10735 re-downloading or rebuilding them.
10737 This operation is not atomic and thus restricted to @code{root}.
10739 @item --derivations
10741 Return the derivation paths, not the output paths, of the given
10744 @item --root=@var{file}
10745 @itemx -r @var{file}
10746 @cindex GC roots, adding
10747 @cindex garbage collector roots, adding
10748 Make @var{file} a symlink to the result, and register it as a garbage
10751 Consequently, the results of this @command{guix build} invocation are
10752 protected from garbage collection until @var{file} is removed. When
10753 that option is omitted, build results are eligible for garbage
10754 collection as soon as the build completes. @xref{Invoking guix gc}, for
10758 @cindex build logs, access
10759 Return the build log file names or URLs for the given
10760 @var{package-or-derivation}, or raise an error if build logs are
10763 This works regardless of how packages or derivations are specified. For
10764 instance, the following invocations are equivalent:
10767 guix build --log-file `guix build -d guile`
10768 guix build --log-file `guix build guile`
10769 guix build --log-file guile
10770 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
10773 If a log is unavailable locally, and unless @option{--no-substitutes} is
10774 passed, the command looks for a corresponding log on one of the
10775 substitute servers (as specified with @option{--substitute-urls}).
10777 So for instance, imagine you want to see the build log of GDB on MIPS,
10778 but you are actually on an @code{x86_64} machine:
10781 $ guix build --log-file gdb -s aarch64-linux
10782 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
10785 You can freely access a huge library of build logs!
10788 @node Debugging Build Failures
10789 @subsection Debugging Build Failures
10791 @cindex build failures, debugging
10792 When defining a new package (@pxref{Defining Packages}), you will
10793 probably find yourself spending some time debugging and tweaking the
10794 build until it succeeds. To do that, you need to operate the build
10795 commands yourself in an environment as close as possible to the one the
10798 To that end, the first thing to do is to use the @option{--keep-failed}
10799 or @option{-K} option of @command{guix build}, which will keep the
10800 failed build tree in @file{/tmp} or whatever directory you specified as
10801 @env{TMPDIR} (@pxref{Invoking guix build, @option{--keep-failed}}).
10803 From there on, you can @command{cd} to the failed build tree and source
10804 the @file{environment-variables} file, which contains all the
10805 environment variable definitions that were in place when the build
10806 failed. So let's say you're debugging a build failure in package
10807 @code{foo}; a typical session would look like this:
10810 $ guix build foo -K
10811 @dots{} @i{build fails}
10812 $ cd /tmp/guix-build-foo.drv-0
10813 $ source ./environment-variables
10817 Now, you can invoke commands as if you were the daemon (almost) and
10818 troubleshoot your build process.
10820 Sometimes it happens that, for example, a package's tests pass when you
10821 run them manually but they fail when the daemon runs them. This can
10822 happen because the daemon runs builds in containers where, unlike in our
10823 environment above, network access is missing, @file{/bin/sh} does not
10824 exist, etc. (@pxref{Build Environment Setup}).
10826 In such cases, you may need to run inspect the build process from within
10827 a container similar to the one the build daemon creates:
10830 $ guix build -K foo
10832 $ cd /tmp/guix-build-foo.drv-0
10833 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
10834 [env]# source ./environment-variables
10838 Here, @command{guix environment -C} creates a container and spawns a new
10839 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
10840 strace gdb} part adds the @command{strace} and @command{gdb} commands to
10841 the container, which you may find handy while debugging. The
10842 @option{--no-grafts} option makes sure we get the exact same
10843 environment, with ungrafted packages (@pxref{Security Updates}, for more
10846 To get closer to a container like that used by the build daemon, we can
10847 remove @file{/bin/sh}:
10853 (Don't worry, this is harmless: this is all happening in the throw-away
10854 container created by @command{guix environment}.)
10856 The @command{strace} command is probably not in the search path, but we
10860 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
10863 In this way, not only you will have reproduced the environment variables
10864 the daemon uses, you will also be running the build process in a container
10865 similar to the one the daemon uses.
10868 @node Invoking guix edit
10869 @section Invoking @command{guix edit}
10871 @cindex @command{guix edit}
10872 @cindex package definition, editing
10873 So many packages, so many source files! The @command{guix edit} command
10874 facilitates the life of users and packagers by pointing their editor at
10875 the source file containing the definition of the specified packages.
10879 guix edit gcc@@4.9 vim
10883 launches the program specified in the @env{VISUAL} or in the
10884 @env{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
10887 If you are using a Guix Git checkout (@pxref{Building from Git}), or
10888 have created your own packages on @env{GUIX_PACKAGE_PATH}
10889 (@pxref{Package Modules}), you will be able to edit the package
10890 recipes. In other cases, you will be able to examine the read-only recipes
10891 for packages currently in the store.
10893 Instead of @env{GUIX_PACKAGE_PATH}, the command-line option
10894 @option{--load-path=@var{directory}} (or in short @option{-L
10895 @var{directory}}) allows you to add @var{directory} to the front of the
10896 package module search path and so make your own packages visible.
10898 @node Invoking guix download
10899 @section Invoking @command{guix download}
10901 @cindex @command{guix download}
10902 @cindex downloading package sources
10903 When writing a package definition, developers typically need to download
10904 a source tarball, compute its SHA256 hash, and write that
10905 hash in the package definition (@pxref{Defining Packages}). The
10906 @command{guix download} tool helps with this task: it downloads a file
10907 from the given URI, adds it to the store, and prints both its file name
10908 in the store and its SHA256 hash.
10910 The fact that the downloaded file is added to the store saves bandwidth:
10911 when the developer eventually tries to build the newly defined package
10912 with @command{guix build}, the source tarball will not have to be
10913 downloaded again because it is already in the store. It is also a
10914 convenient way to temporarily stash files, which may be deleted
10915 eventually (@pxref{Invoking guix gc}).
10917 The @command{guix download} command supports the same URIs as used in
10918 package definitions. In particular, it supports @code{mirror://} URIs.
10919 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
10920 Guile bindings for GnuTLS are available in the user's environment; when
10921 they are not available, an error is raised. @xref{Guile Preparations,
10922 how to install the GnuTLS bindings for Guile,, gnutls-guile,
10923 GnuTLS-Guile}, for more information.
10925 @command{guix download} verifies HTTPS server certificates by loading
10926 the certificates of X.509 authorities from the directory pointed to by
10927 the @env{SSL_CERT_DIR} environment variable (@pxref{X.509
10928 Certificates}), unless @option{--no-check-certificate} is used.
10930 The following options are available:
10933 @item --hash=@var{algorithm}
10934 @itemx -H @var{algorithm}
10935 Compute a hash using the specified @var{algorithm}. @xref{Invoking guix
10936 hash}, for more information.
10938 @item --format=@var{fmt}
10939 @itemx -f @var{fmt}
10940 Write the hash in the format specified by @var{fmt}. For more
10941 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
10943 @item --no-check-certificate
10944 Do not validate the X.509 certificates of HTTPS servers.
10946 When using this option, you have @emph{absolutely no guarantee} that you
10947 are communicating with the authentic server responsible for the given
10948 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
10950 @item --output=@var{file}
10951 @itemx -o @var{file}
10952 Save the downloaded file to @var{file} instead of adding it to the
10956 @node Invoking guix hash
10957 @section Invoking @command{guix hash}
10959 @cindex @command{guix hash}
10960 The @command{guix hash} command computes the hash of a file.
10961 It is primarily a convenience tool for anyone contributing to the
10962 distribution: it computes the cryptographic hash of a file, which can be
10963 used in the definition of a package (@pxref{Defining Packages}).
10965 The general syntax is:
10968 guix hash @var{option} @var{file}
10971 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
10972 hash of data read from standard input. @command{guix hash} has the
10977 @item --hash=@var{algorithm}
10978 @itemx -H @var{algorithm}
10979 Compute a hash using the specified @var{algorithm}, @code{sha256} by
10982 @var{algorithm} must the name of a cryptographic hash algorithm
10983 supported by Libgcrypt @i{via} Guile-Gcrypt---e.g., @code{sha512} or
10984 @code{sha3-256} (@pxref{Hash Functions,,, guile-gcrypt, Guile-Gcrypt
10985 Reference Manual}).
10987 @item --format=@var{fmt}
10988 @itemx -f @var{fmt}
10989 Write the hash in the format specified by @var{fmt}.
10991 Supported formats: @code{base64}, @code{nix-base32}, @code{base32}, @code{base16}
10992 (@code{hex} and @code{hexadecimal} can be used as well).
10994 If the @option{--format} option is not specified, @command{guix hash}
10995 will output the hash in @code{nix-base32}. This representation is used
10996 in the definitions of packages.
11000 Compute the hash on @var{file} recursively.
11002 In this case, the hash is computed on an archive containing @var{file},
11003 including its children if it is a directory. Some of the metadata of
11004 @var{file} is part of the archive; for instance, when @var{file} is a
11005 regular file, the hash is different depending on whether @var{file} is
11006 executable or not. Metadata such as time stamps has no impact on the
11007 hash (@pxref{Invoking guix archive}).
11008 @c FIXME: Replace xref above with xref to an ``Archive'' section when
11011 @item --exclude-vcs
11013 When combined with @option{--recursive}, exclude version control system
11014 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.).
11017 As an example, here is how you would compute the hash of a Git checkout,
11018 which is useful when using the @code{git-fetch} method (@pxref{origin
11022 $ git clone http://example.org/foo.git
11028 @node Invoking guix import
11029 @section Invoking @command{guix import}
11031 @cindex importing packages
11032 @cindex package import
11033 @cindex package conversion
11034 @cindex Invoking @command{guix import}
11035 The @command{guix import} command is useful for people who would like to
11036 add a package to the distribution with as little work as
11037 possible---a legitimate demand. The command knows of a few
11038 repositories from which it can ``import'' package metadata. The result
11039 is a package definition, or a template thereof, in the format we know
11040 (@pxref{Defining Packages}).
11042 The general syntax is:
11045 guix import @var{importer} @var{options}@dots{}
11048 @var{importer} specifies the source from which to import package
11049 metadata, and @var{options} specifies a package identifier and other
11050 options specific to @var{importer}.
11052 Some of the importers rely on the ability to run the @command{gpgv} command.
11053 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
11056 Currently, the available ``importers'' are:
11060 Import metadata for the given GNU package. This provides a template
11061 for the latest version of that GNU package, including the hash of its
11062 source tarball, and its canonical synopsis and description.
11064 Additional information such as the package dependencies and its
11065 license needs to be figured out manually.
11067 For example, the following command returns a package definition for
11071 guix import gnu hello
11074 Specific command-line options are:
11077 @item --key-download=@var{policy}
11078 As for @command{guix refresh}, specify the policy to handle missing
11079 OpenPGP keys when verifying the package signature. @xref{Invoking guix
11080 refresh, @option{--key-download}}.
11085 Import metadata from the @uref{https://pypi.python.org/, Python Package
11086 Index}. Information is taken from the JSON-formatted description
11087 available at @code{pypi.python.org} and usually includes all the relevant
11088 information, including package dependencies. For maximum efficiency, it
11089 is recommended to install the @command{unzip} utility, so that the
11090 importer can unzip Python wheels and gather data from them.
11092 The command below imports metadata for the @code{itsdangerous} Python
11096 guix import pypi itsdangerous
11102 Traverse the dependency graph of the given upstream package recursively
11103 and generate package expressions for all those packages that are not yet
11109 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
11110 is taken from the JSON-formatted description available at
11111 @code{rubygems.org} and includes most relevant information, including
11112 runtime dependencies. There are some caveats, however. The metadata
11113 doesn't distinguish between synopses and descriptions, so the same string
11114 is used for both fields. Additionally, the details of non-Ruby
11115 dependencies required to build native extensions is unavailable and left
11116 as an exercise to the packager.
11118 The command below imports metadata for the @code{rails} Ruby package:
11121 guix import gem rails
11127 Traverse the dependency graph of the given upstream package recursively
11128 and generate package expressions for all those packages that are not yet
11134 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
11135 Information is taken from the JSON-formatted metadata provided through
11136 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
11137 relevant information, such as module dependencies. License information
11138 should be checked closely. If Perl is available in the store, then the
11139 @code{corelist} utility will be used to filter core modules out of the
11140 list of dependencies.
11142 The command command below imports metadata for the Acme::Boolean Perl
11146 guix import cpan Acme::Boolean
11151 @cindex Bioconductor
11152 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
11153 central repository for the @uref{https://r-project.org, GNU@tie{}R
11154 statistical and graphical environment}.
11156 Information is extracted from the @file{DESCRIPTION} file of the package.
11158 The command command below imports metadata for the Cairo R package:
11161 guix import cran Cairo
11164 When @option{--recursive} is added, the importer will traverse the
11165 dependency graph of the given upstream package recursively and generate
11166 package expressions for all those packages that are not yet in Guix.
11168 When @option{--style=specification} is added, the importer will generate
11169 package definitions whose inputs are package specifications instead of
11170 references to package variables. This is useful when generated package
11171 definitions are to be appended to existing user modules, as the list of
11172 used package modules need not be changed. The default is
11173 @option{--style=variable}.
11175 When @option{--archive=bioconductor} is added, metadata is imported from
11176 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
11177 packages for the analysis and comprehension of high-throughput
11178 genomic data in bioinformatics.
11180 Information is extracted from the @file{DESCRIPTION} file contained in the
11183 The command below imports metadata for the GenomicRanges R package:
11186 guix import cran --archive=bioconductor GenomicRanges
11189 Finally, you can also import R packages that have not yet been published on
11190 CRAN or Bioconductor as long as they are in a git repository. Use
11191 @option{--archive=git} followed by the URL of the git repository:
11194 guix import cran --archive=git https://github.com/immunogenomics/harmony
11200 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
11201 comprehensive TeX archive network for TeX packages that are part of the
11202 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
11204 Information about the package is obtained through the XML API provided
11205 by CTAN, while the source code is downloaded from the SVN repository of
11206 the Tex Live project. This is done because the CTAN does not keep
11207 versioned archives.
11209 The command command below imports metadata for the @code{fontspec}
11213 guix import texlive fontspec
11216 When @option{--archive=@var{directory}} is added, the source code is
11217 downloaded not from the @file{latex} sub-directory of the
11218 @file{texmf-dist/source} tree in the TeX Live SVN repository, but from
11219 the specified sibling @var{directory} under the same root.
11221 The command below imports metadata for the @code{ifxetex} package from
11222 CTAN while fetching the sources from the directory
11223 @file{texmf/source/generic}:
11226 guix import texlive --archive=generic ifxetex
11230 @cindex JSON, import
11231 Import package metadata from a local JSON file. Consider the following
11232 example package definition in JSON format:
11238 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
11239 "build-system": "gnu",
11240 "home-page": "https://www.gnu.org/software/hello/",
11241 "synopsis": "Hello, GNU world: An example GNU package",
11242 "description": "GNU Hello prints a greeting.",
11243 "license": "GPL-3.0+",
11244 "native-inputs": ["gettext"]
11248 The field names are the same as for the @code{<package>} record
11249 (@xref{Defining Packages}). References to other packages are provided
11250 as JSON lists of quoted package specification strings such as
11251 @code{guile} or @code{guile@@2.0}.
11253 The importer also supports a more explicit source definition using the
11254 common fields for @code{<origin>} records:
11260 "method": "url-fetch",
11261 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
11263 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
11270 The command below reads metadata from the JSON file @code{hello.json}
11271 and outputs a package expression:
11274 guix import json hello.json
11278 Import metadata from a local copy of the source of the
11279 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
11280 relies on the @command{nix-instantiate} command of
11281 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
11282 typically written in a mixture of Nix-language and Bash code. This
11283 command only imports the high-level package structure that is written in
11284 the Nix language. It normally includes all the basic fields of a
11285 package definition.
11287 When importing a GNU package, the synopsis and descriptions are replaced
11288 by their canonical upstream variant.
11290 Usually, you will first need to do:
11293 export NIX_REMOTE=daemon
11297 so that @command{nix-instantiate} does not try to open the Nix database.
11299 As an example, the command below imports the package definition of
11300 LibreOffice (more precisely, it imports the definition of the package
11301 bound to the @code{libreoffice} top-level attribute):
11304 guix import nix ~/path/to/nixpkgs libreoffice
11309 Import metadata from the Haskell community's central package archive
11310 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
11311 Cabal files and includes all the relevant information, including package
11314 Specific command-line options are:
11319 Read a Cabal file from standard input.
11320 @item --no-test-dependencies
11322 Do not include dependencies required only by the test suites.
11323 @item --cabal-environment=@var{alist}
11324 @itemx -e @var{alist}
11325 @var{alist} is a Scheme alist defining the environment in which the
11326 Cabal conditionals are evaluated. The accepted keys are: @code{os},
11327 @code{arch}, @code{impl} and a string representing the name of a flag.
11328 The value associated with a flag has to be either the symbol
11329 @code{true} or @code{false}. The value associated with other keys
11330 has to conform to the Cabal file format definition. The default value
11331 associated with the keys @code{os}, @code{arch} and @code{impl} is
11332 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
11335 Traverse the dependency graph of the given upstream package recursively
11336 and generate package expressions for all those packages that are not yet
11340 The command below imports metadata for the latest version of the
11341 HTTP Haskell package without including test dependencies and
11342 specifying the value of the flag @samp{network-uri} as @code{false}:
11345 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
11348 A specific package version may optionally be specified by following the
11349 package name by an at-sign and a version number as in the following example:
11352 guix import hackage mtl@@2.1.3.1
11357 The @code{stackage} importer is a wrapper around the @code{hackage} one.
11358 It takes a package name, looks up the package version included in a
11359 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
11360 release and uses the @code{hackage} importer to retrieve its metadata.
11361 Note that it is up to you to select an LTS release compatible with the
11362 GHC compiler used by Guix.
11364 Specific command-line options are:
11367 @item --no-test-dependencies
11369 Do not include dependencies required only by the test suites.
11370 @item --lts-version=@var{version}
11371 @itemx -l @var{version}
11372 @var{version} is the desired LTS release version. If omitted the latest
11376 Traverse the dependency graph of the given upstream package recursively
11377 and generate package expressions for all those packages that are not yet
11381 The command below imports metadata for the HTTP Haskell package
11382 included in the LTS Stackage release version 7.18:
11385 guix import stackage --lts-version=7.18 HTTP
11390 Import metadata from an Emacs Lisp Package Archive (ELPA) package
11391 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
11393 Specific command-line options are:
11396 @item --archive=@var{repo}
11397 @itemx -a @var{repo}
11398 @var{repo} identifies the archive repository from which to retrieve the
11399 information. Currently the supported repositories and their identifiers
11403 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
11404 identifier. This is the default.
11406 Packages from @code{elpa.gnu.org} are signed with one of the keys
11407 contained in the GnuPG keyring at
11408 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
11409 @code{emacs} package (@pxref{Package Installation, ELPA package
11410 signatures,, emacs, The GNU Emacs Manual}).
11413 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
11414 @code{melpa-stable} identifier.
11417 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
11423 Traverse the dependency graph of the given upstream package recursively
11424 and generate package expressions for all those packages that are not yet
11430 Import metadata from the crates.io Rust package repository
11431 @uref{https://crates.io, crates.io}, as in this example:
11434 guix import crate blake2-rfc
11437 The crate importer also allows you to specify a version string:
11440 guix import crate constant-time-eq@@0.1.0
11443 Additional options include:
11448 Traverse the dependency graph of the given upstream package recursively
11449 and generate package expressions for all those packages that are not yet
11456 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
11457 repository used by the OCaml community.
11459 Additional options include:
11464 Traverse the dependency graph of the given upstream package recursively
11465 and generate package expressions for all those packages that are not yet
11468 Select the given repository (a repository name). Possible values include:
11470 @item @code{opam}, the default opam repository,
11471 @item @code{coq} or @code{coq-released}, the stable repository for coq packages,
11472 @item @code{coq-core-dev}, the repository that contains development versions of coq,
11473 @item @code{coq-extra-dev}, the repository that contains development versions
11479 The structure of the @command{guix import} code is modular. It would be
11480 useful to have more importers for other package formats, and your help
11481 is welcome here (@pxref{Contributing}).
11483 @node Invoking guix refresh
11484 @section Invoking @command{guix refresh}
11486 @cindex @command {guix refresh}
11487 The primary audience of the @command{guix refresh} command is developers
11488 of the GNU software distribution. By default, it reports any packages
11489 provided by the distribution that are outdated compared to the latest
11490 upstream version, like this:
11494 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
11495 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
11498 Alternatively, one can specify packages to consider, in which case a
11499 warning is emitted for packages that lack an updater:
11502 $ guix refresh coreutils guile guile-ssh
11503 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
11504 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
11507 @command{guix refresh} browses the upstream repository of each package and determines
11508 the highest version number of the releases therein. The command
11509 knows how to update specific types of packages: GNU packages, ELPA
11510 packages, etc.---see the documentation for @option{--type} below. There
11511 are many packages, though, for which it lacks a method to determine
11512 whether a new upstream release is available. However, the mechanism is
11513 extensible, so feel free to get in touch with us to add a new method!
11518 Consider the packages specified, and all the packages upon which they depend.
11521 $ guix refresh --recursive coreutils
11522 gnu/packages/acl.scm:35:2: warning: no updater for acl
11523 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
11524 gnu/packages/xml.scm:68:2: warning: no updater for expat
11525 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
11531 Sometimes the upstream name differs from the package name used in Guix,
11532 and @command{guix refresh} needs a little help. Most updaters honor the
11533 @code{upstream-name} property in package definitions, which can be used
11537 (define-public network-manager
11539 (name "network-manager")
11541 (properties '((upstream-name . "NetworkManager")))))
11544 When passed @option{--update}, it modifies distribution source files to
11545 update the version numbers and source tarball hashes of those package
11546 recipes (@pxref{Defining Packages}). This is achieved by downloading
11547 each package's latest source tarball and its associated OpenPGP
11548 signature, authenticating the downloaded tarball against its signature
11549 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
11550 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
11553 key used to sign the tarball is missing from the user's keyring, an
11554 attempt is made to automatically retrieve it from a public key server;
11555 when this is successful, the key is added to the user's keyring; otherwise,
11556 @command{guix refresh} reports an error.
11558 The following options are supported:
11562 @item --expression=@var{expr}
11563 @itemx -e @var{expr}
11564 Consider the package @var{expr} evaluates to.
11566 This is useful to precisely refer to a package, as in this example:
11569 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
11572 This command lists the dependents of the ``final'' libc (essentially all
11577 Update distribution source files (package recipes) in place. This is
11578 usually run from a checkout of the Guix source tree (@pxref{Running
11579 Guix Before It Is Installed}):
11582 $ ./pre-inst-env guix refresh -s non-core -u
11585 @xref{Defining Packages}, for more information on package definitions.
11587 @item --select=[@var{subset}]
11588 @itemx -s @var{subset}
11589 Select all the packages in @var{subset}, one of @code{core} or
11592 The @code{core} subset refers to all the packages at the core of the
11593 distribution---i.e., packages that are used to build ``everything
11594 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
11595 changing one of these packages in the distribution entails a rebuild of
11596 all the others. Thus, such updates are an inconvenience to users in
11597 terms of build time or bandwidth used to achieve the upgrade.
11599 The @code{non-core} subset refers to the remaining packages. It is
11600 typically useful in cases where an update of the core packages would be
11603 @item --manifest=@var{file}
11604 @itemx -m @var{file}
11605 Select all the packages from the manifest in @var{file}. This is useful to
11606 check if any packages of the user manifest can be updated.
11608 @item --type=@var{updater}
11609 @itemx -t @var{updater}
11610 Select only packages handled by @var{updater} (may be a comma-separated
11611 list of updaters). Currently, @var{updater} may be one of:
11615 the updater for GNU packages;
11617 the updater for packages hosted at @uref{https://savannah.gnu.org, Savannah};
11619 the updater for GNOME packages;
11621 the updater for KDE packages;
11623 the updater for X.org packages;
11625 the updater for packages hosted on kernel.org;
11627 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
11629 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
11631 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
11633 the updater for @uref{https://www.cpan.org/, CPAN} packages;
11635 the updater for @uref{https://pypi.python.org, PyPI} packages.
11637 the updater for @uref{https://rubygems.org, RubyGems} packages.
11639 the updater for @uref{https://github.com, GitHub} packages.
11641 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
11643 the updater for @uref{https://www.stackage.org, Stackage} packages.
11645 the updater for @uref{https://crates.io, Crates} packages.
11647 the updater for @uref{https://launchpad.net, Launchpad} packages.
11650 For instance, the following command only checks for updates of Emacs
11651 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
11654 $ guix refresh --type=elpa,cran
11655 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
11656 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
11661 In addition, @command{guix refresh} can be passed one or more package
11662 names, as in this example:
11665 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
11669 The command above specifically updates the @code{emacs} and
11670 @code{idutils} packages. The @option{--select} option would have no
11671 effect in this case.
11673 When considering whether to upgrade a package, it is sometimes
11674 convenient to know which packages would be affected by the upgrade and
11675 should be checked for compatibility. For this the following option may
11676 be used when passing @command{guix refresh} one or more package names:
11680 @item --list-updaters
11682 List available updaters and exit (see @option{--type} above).
11684 For each updater, display the fraction of packages it covers; at the
11685 end, display the fraction of packages covered by all these updaters.
11687 @item --list-dependent
11689 List top-level dependent packages that would need to be rebuilt as a
11690 result of upgrading one or more packages.
11692 @xref{Invoking guix graph, the @code{reverse-package} type of
11693 @command{guix graph}}, for information on how to visualize the list of
11694 dependents of a package.
11698 Be aware that the @option{--list-dependent} option only
11699 @emph{approximates} the rebuilds that would be required as a result of
11700 an upgrade. More rebuilds might be required under some circumstances.
11703 $ guix refresh --list-dependent flex
11704 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
11705 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
11708 The command above lists a set of packages that could be built to check
11709 for compatibility with an upgraded @code{flex} package.
11713 @item --list-transitive
11714 List all the packages which one or more packages depend upon.
11717 $ guix refresh --list-transitive flex
11718 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
11719 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{}
11724 The command above lists a set of packages which, when changed, would cause
11725 @code{flex} to be rebuilt.
11727 The following options can be used to customize GnuPG operation:
11731 @item --gpg=@var{command}
11732 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
11733 for in @code{$PATH}.
11735 @item --keyring=@var{file}
11736 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
11737 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
11738 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
11739 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
11740 information on a tool to manipulate keybox files).
11742 When this option is omitted, @command{guix refresh} uses
11743 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
11744 signing keys. OpenPGP signatures are checked against keys from this keyring;
11745 missing keys are downloaded to this keyring as well (see
11746 @option{--key-download} below).
11748 You can export keys from your default GPG keyring into a keybox file using
11749 commands like this one:
11752 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
11755 Likewise, you can fetch keys to a specific keybox file like this:
11758 gpg --no-default-keyring --keyring mykeyring.kbx \
11759 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
11762 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
11763 Privacy Guard}, for more information on GPG's @option{--keyring} option.
11765 @item --key-download=@var{policy}
11766 Handle missing OpenPGP keys according to @var{policy}, which may be one
11771 Always download missing OpenPGP keys from the key server, and add them
11772 to the user's GnuPG keyring.
11775 Never try to download missing OpenPGP keys. Instead just bail out.
11778 When a package signed with an unknown OpenPGP key is encountered, ask
11779 the user whether to download it or not. This is the default behavior.
11782 @item --key-server=@var{host}
11783 Use @var{host} as the OpenPGP key server when importing a public key.
11785 @item --load-path=@var{directory}
11786 Add @var{directory} to the front of the package module search path
11787 (@pxref{Package Modules}).
11789 This allows users to define their own packages and make them visible to
11790 the command-line tools.
11794 The @code{github} updater uses the
11795 @uref{https://developer.github.com/v3/, GitHub API} to query for new
11796 releases. When used repeatedly e.g.@: when refreshing all packages,
11797 GitHub will eventually refuse to answer any further API requests. By
11798 default 60 API requests per hour are allowed, and a full refresh on all
11799 GitHub packages in Guix requires more than this. Authentication with
11800 GitHub through the use of an API token alleviates these limits. To use
11801 an API token, set the environment variable @env{GUIX_GITHUB_TOKEN} to a
11802 token procured from @uref{https://github.com/settings/tokens} or
11806 @node Invoking guix lint
11807 @section Invoking @command{guix lint}
11809 @cindex @command{guix lint}
11810 @cindex package, checking for errors
11811 The @command{guix lint} command is meant to help package developers avoid
11812 common errors and use a consistent style. It runs a number of checks on
11813 a given set of packages in order to find common mistakes in their
11814 definitions. Available @dfn{checkers} include (see
11815 @option{--list-checkers} for a complete list):
11820 Validate certain typographical and stylistic rules about package
11821 descriptions and synopses.
11823 @item inputs-should-be-native
11824 Identify inputs that should most likely be native inputs.
11830 @itemx source-file-name
11831 Probe @code{home-page} and @code{source} URLs and report those that are
11832 invalid. Suggest a @code{mirror://} URL when applicable. If the
11833 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
11834 URL@. Check that the source file name is meaningful, e.g.@: is not just a
11835 version number or ``git-checkout'', without a declared @code{file-name}
11836 (@pxref{origin Reference}).
11838 @item source-unstable-tarball
11839 Parse the @code{source} URL to determine if a tarball from GitHub is
11840 autogenerated or if it is a release tarball. Unfortunately GitHub's
11841 autogenerated tarballs are sometimes regenerated.
11844 Check that the derivation of the given packages can be successfully
11845 computed for all the supported systems (@pxref{Derivations}).
11847 @item profile-collisions
11848 Check whether installing the given packages in a profile would lead to
11849 collisions. Collisions occur when several packages with the same name
11850 but a different version or a different store file name are propagated.
11851 @xref{package Reference, @code{propagated-inputs}}, for more information
11852 on propagated inputs.
11855 @cindex Software Heritage, source code archive
11856 @cindex archival of source code, Software Heritage
11857 Checks whether the package's source code is archived at
11858 @uref{https://www.softwareheritage.org, Software Heritage}.
11860 When the source code that is not archived comes from a version-control system
11861 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
11862 ``save'' request so that it eventually archives it. This ensures that the
11863 source will remain available in the long term, and that Guix can fall back to
11864 Software Heritage should the source code disappear from its original host.
11865 The status of recent ``save'' requests can be
11866 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
11868 When source code is a tarball obtained with @code{url-fetch}, simply print a
11869 message when it is not archived. As of this writing, Software Heritage does
11870 not allow requests to save arbitrary tarballs; we are working on ways to
11871 ensure that non-VCS source code is also archived.
11874 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
11875 request rate per IP address}. When the limit is reached, @command{guix lint}
11876 prints a message and the @code{archival} checker stops doing anything until
11877 that limit has been reset.
11880 @cindex security vulnerabilities
11881 @cindex CVE, Common Vulnerabilities and Exposures
11882 Report known vulnerabilities found in the Common Vulnerabilities and
11883 Exposures (CVE) databases of the current and past year
11884 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
11887 To view information about a particular vulnerability, visit pages such as:
11891 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
11893 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
11897 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
11898 @code{CVE-2015-7554}.
11900 Package developers can specify in package recipes the
11901 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
11902 name and version of the package when they differ from the name or version
11903 that Guix uses, as in this example:
11909 ;; CPE calls this package "grub2".
11910 (properties '((cpe-name . "grub2")
11911 (cpe-version . "2.3"))))
11914 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
11915 Some entries in the CVE database do not specify which version of a
11916 package they apply to, and would thus ``stick around'' forever. Package
11917 developers who found CVE alerts and verified they can be ignored can
11918 declare them as in this example:
11924 ;; These CVEs no longer apply and can be safely ignored.
11925 (properties `((lint-hidden-cve . ("CVE-2011-0433"
11928 "CVE-2011-5244")))))
11932 Warn about obvious source code formatting issues: trailing white space,
11933 use of tabulations, etc.
11936 The general syntax is:
11939 guix lint @var{options} @var{package}@dots{}
11942 If no package is given on the command line, then all packages are checked.
11943 The @var{options} may be zero or more of the following:
11946 @item --list-checkers
11948 List and describe all the available checkers that will be run on packages
11953 Only enable the checkers specified in a comma-separated list using the
11954 names returned by @option{--list-checkers}.
11958 Only disable the checkers specified in a comma-separated list using the
11959 names returned by @option{--list-checkers}.
11963 Only enable the checkers that do not depend on Internet access.
11965 @item --load-path=@var{directory}
11966 @itemx -L @var{directory}
11967 Add @var{directory} to the front of the package module search path
11968 (@pxref{Package Modules}).
11970 This allows users to define their own packages and make them visible to
11971 the command-line tools.
11975 @node Invoking guix size
11976 @section Invoking @command{guix size}
11979 @cindex package size
11981 @cindex @command{guix size}
11982 The @command{guix size} command helps package developers profile the
11983 disk usage of packages. It is easy to overlook the impact of an
11984 additional dependency added to a package, or the impact of using a
11985 single output for a package that could easily be split (@pxref{Packages
11986 with Multiple Outputs}). Such are the typical issues that
11987 @command{guix size} can highlight.
11989 The command can be passed one or more package specifications
11990 such as @code{gcc@@4.8}
11991 or @code{guile:debug}, or a file name in the store. Consider this
11995 $ guix size coreutils
11996 store item total self
11997 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
11998 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
11999 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
12000 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
12001 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
12002 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
12003 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
12004 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
12009 The store items listed here constitute the @dfn{transitive closure} of
12010 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
12011 would be returned by:
12014 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
12017 Here the output shows three columns next to store items. The first column,
12018 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
12019 the store item---that is, its own size plus the size of all its
12020 dependencies. The next column, labeled ``self'', shows the size of the
12021 item itself. The last column shows the ratio of the size of the item
12022 itself to the space occupied by all the items listed here.
12024 In this example, we see that the closure of Coreutils weighs in at
12025 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
12026 libraries. (That libc and GCC's libraries represent a large fraction of
12027 the closure is not a problem @i{per se} because they are always available
12028 on the system anyway.)
12030 Since the command also accepts store file names, assessing the size of
12031 a build result is straightforward:
12034 guix size $(guix system build config.scm)
12037 When the package(s) passed to @command{guix size} are available in the
12038 store@footnote{More precisely, @command{guix size} looks for the
12039 @emph{ungrafted} variant of the given package(s), as returned by
12040 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
12041 for information on grafts.}, @command{guix size} queries the daemon to determine its
12042 dependencies, and measures its size in the store, similar to @command{du
12043 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
12046 When the given packages are @emph{not} in the store, @command{guix size}
12047 reports information based on the available substitutes
12048 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
12049 store items that are not even on disk, only available remotely.
12051 You can also specify several package names:
12054 $ guix size coreutils grep sed bash
12055 store item total self
12056 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
12057 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
12058 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
12059 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
12065 In this example we see that the combination of the four packages takes
12066 102.3@tie{}MiB in total, which is much less than the sum of each closure
12067 since they have a lot of dependencies in common.
12069 When looking at the profile returned by @command{guix size}, you may
12070 find yourself wondering why a given package shows up in the profile at
12071 all. To understand it, you can use @command{guix graph --path -t
12072 references} to display the shortest path between the two packages
12073 (@pxref{Invoking guix graph}).
12075 The available options are:
12079 @item --substitute-urls=@var{urls}
12080 Use substitute information from @var{urls}.
12081 @xref{client-substitute-urls, the same option for @code{guix build}}.
12083 @item --sort=@var{key}
12084 Sort lines according to @var{key}, one of the following options:
12088 the size of each item (the default);
12090 the total size of the item's closure.
12093 @item --map-file=@var{file}
12094 Write a graphical map of disk usage in PNG format to @var{file}.
12096 For the example above, the map looks like this:
12098 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
12099 produced by @command{guix size}}
12101 This option requires that
12102 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
12103 installed and visible in Guile's module search path. When that is not
12104 the case, @command{guix size} fails as it tries to load it.
12106 @item --system=@var{system}
12107 @itemx -s @var{system}
12108 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
12110 @item --load-path=@var{directory}
12111 @itemx -L @var{directory}
12112 Add @var{directory} to the front of the package module search path
12113 (@pxref{Package Modules}).
12115 This allows users to define their own packages and make them visible to
12116 the command-line tools.
12119 @node Invoking guix graph
12120 @section Invoking @command{guix graph}
12123 @cindex @command{guix graph}
12124 @cindex package dependencies
12125 Packages and their dependencies form a @dfn{graph}, specifically a
12126 directed acyclic graph (DAG). It can quickly become difficult to have a
12127 mental model of the package DAG, so the @command{guix graph} command
12128 provides a visual representation of the DAG@. By default,
12129 @command{guix graph} emits a DAG representation in the input format of
12130 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
12131 directly to the @command{dot} command of Graphviz. It can also emit an
12132 HTML page with embedded JavaScript code to display a ``chord diagram''
12133 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
12134 emit Cypher queries to construct a graph in a graph database supporting
12135 the @uref{https://www.opencypher.org/, openCypher} query language. With
12136 @option{--path}, it simply displays the shortest path between two
12137 packages. The general syntax is:
12140 guix graph @var{options} @var{package}@dots{}
12143 For example, the following command generates a PDF file representing the
12144 package DAG for the GNU@tie{}Core Utilities, showing its build-time
12148 guix graph coreutils | dot -Tpdf > dag.pdf
12151 The output looks like this:
12153 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
12155 Nice little graph, no?
12157 You may find it more pleasant to navigate the graph interactively with
12158 @command{xdot} (from the @code{xdot} package):
12161 guix graph coreutils | xdot -
12164 But there is more than one graph! The one above is concise: it is the
12165 graph of package objects, omitting implicit inputs such as GCC, libc,
12166 grep, etc. It is often useful to have such a concise graph, but
12167 sometimes one may want to see more details. @command{guix graph} supports
12168 several types of graphs, allowing you to choose the level of detail:
12172 This is the default type used in the example above. It shows the DAG of
12173 package objects, excluding implicit dependencies. It is concise, but
12174 filters out many details.
12176 @item reverse-package
12177 This shows the @emph{reverse} DAG of packages. For example:
12180 guix graph --type=reverse-package ocaml
12183 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
12184 you are also interested in cases where OCaml is an implicit dependency, see
12185 @code{reverse-bag} below).
12187 Note that for core packages this can yield huge graphs. If all you want
12188 is to know the number of packages that depend on a given package, use
12189 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
12190 @option{--list-dependent}}).
12193 This is the package DAG, @emph{including} implicit inputs.
12195 For instance, the following command:
12198 guix graph --type=bag-emerged coreutils
12201 ...@: yields this bigger graph:
12203 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
12205 At the bottom of the graph, we see all the implicit inputs of
12206 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
12208 Now, note that the dependencies of these implicit inputs---that is, the
12209 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
12210 here, for conciseness.
12213 Similar to @code{bag-emerged}, but this time including all the bootstrap
12216 @item bag-with-origins
12217 Similar to @code{bag}, but also showing origins and their dependencies.
12220 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
12221 it also takes implicit dependencies into account. For example:
12224 guix graph -t reverse-bag dune
12228 ...@: yields the graph of all packages that depend on Dune, directly or
12229 indirectly. Since Dune is an @emph{implicit} dependency of many packages
12230 @i{via} @code{dune-build-system}, this shows a large number of packages,
12231 whereas @code{reverse-package} would show very few if any.
12234 This is the most detailed representation: It shows the DAG of
12235 derivations (@pxref{Derivations}) and plain store items. Compared to
12236 the above representation, many additional nodes are visible, including
12237 build scripts, patches, Guile modules, etc.
12239 For this type of graph, it is also possible to pass a @file{.drv} file
12240 name instead of a package name, as in:
12243 guix graph -t derivation `guix system build -d my-config.scm`
12247 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
12248 For example, the following command shows the graph for the package
12249 module that defines the @code{guile} package:
12252 guix graph -t module guile | xdot -
12256 All the types above correspond to @emph{build-time dependencies}. The
12257 following graph type represents the @emph{run-time dependencies}:
12261 This is the graph of @dfn{references} of a package output, as returned
12262 by @command{guix gc --references} (@pxref{Invoking guix gc}).
12264 If the given package output is not available in the store, @command{guix
12265 graph} attempts to obtain dependency information from substitutes.
12267 Here you can also pass a store file name instead of a package name. For
12268 example, the command below produces the reference graph of your profile
12269 (which can be big!):
12272 guix graph -t references `readlink -f ~/.guix-profile`
12276 This is the graph of the @dfn{referrers} of a store item, as returned by
12277 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
12279 This relies exclusively on local information from your store. For
12280 instance, let us suppose that the current Inkscape is available in 10
12281 profiles on your machine; @command{guix graph -t referrers inkscape}
12282 will show a graph rooted at Inkscape and with those 10 profiles linked
12285 It can help determine what is preventing a store item from being garbage
12290 @cindex shortest path, between packages
12291 Often, the graph of the package you are interested in does not fit on
12292 your screen, and anyway all you want to know is @emph{why} that package
12293 actually depends on some seemingly unrelated package. The
12294 @option{--path} option instructs @command{guix graph} to display the
12295 shortest path between two packages (or derivations, or store items,
12299 $ guix graph --path emacs libunistring
12302 libunistring@@0.9.10
12303 $ guix graph --path -t derivation emacs libunistring
12304 /gnu/store/@dots{}-emacs-26.3.drv
12305 /gnu/store/@dots{}-mailutils-3.9.drv
12306 /gnu/store/@dots{}-libunistring-0.9.10.drv
12307 $ guix graph --path -t references emacs libunistring
12308 /gnu/store/@dots{}-emacs-26.3
12309 /gnu/store/@dots{}-libidn2-2.2.0
12310 /gnu/store/@dots{}-libunistring-0.9.10
12313 The available options are the following:
12316 @item --type=@var{type}
12317 @itemx -t @var{type}
12318 Produce a graph output of @var{type}, where @var{type} must be one of
12319 the values listed above.
12322 List the supported graph types.
12324 @item --backend=@var{backend}
12325 @itemx -b @var{backend}
12326 Produce a graph using the selected @var{backend}.
12328 @item --list-backends
12329 List the supported graph backends.
12331 Currently, the available backends are Graphviz and d3.js.
12334 Display the shortest path between two nodes of the type specified by
12335 @option{--type}. The example below shows the shortest path between
12336 @code{libreoffice} and @code{llvm} according to the references of
12337 @code{libreoffice}:
12340 $ guix graph --path -t references libreoffice llvm
12341 /gnu/store/@dots{}-libreoffice-6.4.2.2
12342 /gnu/store/@dots{}-libepoxy-1.5.4
12343 /gnu/store/@dots{}-mesa-19.3.4
12344 /gnu/store/@dots{}-llvm-9.0.1
12347 @item --expression=@var{expr}
12348 @itemx -e @var{expr}
12349 Consider the package @var{expr} evaluates to.
12351 This is useful to precisely refer to a package, as in this example:
12354 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
12357 @item --system=@var{system}
12358 @itemx -s @var{system}
12359 Display the graph for @var{system}---e.g., @code{i686-linux}.
12361 The package dependency graph is largely architecture-independent, but there
12362 are some architecture-dependent bits that this option allows you to visualize.
12364 @item --load-path=@var{directory}
12365 @itemx -L @var{directory}
12366 Add @var{directory} to the front of the package module search path
12367 (@pxref{Package Modules}).
12369 This allows users to define their own packages and make them visible to
12370 the command-line tools.
12373 On top of that, @command{guix graph} supports all the usual package
12374 transformation options (@pxref{Package Transformation Options}). This
12375 makes it easy to view the effect of a graph-rewriting transformation
12376 such as @option{--with-input}. For example, the command below outputs
12377 the graph of @code{git} once @code{openssl} has been replaced by
12378 @code{libressl} everywhere in the graph:
12381 guix graph git --with-input=openssl=libressl
12384 So many possibilities, so much fun!
12386 @node Invoking guix publish
12387 @section Invoking @command{guix publish}
12389 @cindex @command{guix publish}
12390 The purpose of @command{guix publish} is to enable users to easily share
12391 their store with others, who can then use it as a substitute server
12392 (@pxref{Substitutes}).
12394 When @command{guix publish} runs, it spawns an HTTP server which allows
12395 anyone with network access to obtain substitutes from it. This means
12396 that any machine running Guix can also act as if it were a build farm,
12397 since the HTTP interface is compatible with Cuirass, the software behind
12398 the @code{@value{SUBSTITUTE-SERVER}} build farm.
12400 For security, each substitute is signed, allowing recipients to check
12401 their authenticity and integrity (@pxref{Substitutes}). Because
12402 @command{guix publish} uses the signing key of the system, which is only
12403 readable by the system administrator, it must be started as root; the
12404 @option{--user} option makes it drop root privileges early on.
12406 The signing key pair must be generated before @command{guix publish} is
12407 launched, using @command{guix archive --generate-key} (@pxref{Invoking
12410 When the @option{--advertise} option is passed, the server advertises
12411 its availability on the local network using multicast DNS (mDNS) and DNS
12412 service discovery (DNS-SD), currently @i{via} Guile-Avahi (@pxref{Top,,,
12413 guile-avahi, Using Avahi in Guile Scheme Programs}).
12415 The general syntax is:
12418 guix publish @var{options}@dots{}
12421 Running @command{guix publish} without any additional arguments will
12422 spawn an HTTP server on port 8080:
12428 Once a publishing server has been authorized, the daemon may download
12429 substitutes from it. @xref{Getting Substitutes from Other Servers}.
12431 By default, @command{guix publish} compresses archives on the fly as it
12432 serves them. This ``on-the-fly'' mode is convenient in that it requires
12433 no setup and is immediately available. However, when serving lots of
12434 clients, we recommend using the @option{--cache} option, which enables
12435 caching of the archives before they are sent to clients---see below for
12436 details. The @command{guix weather} command provides a handy way to
12437 check what a server provides (@pxref{Invoking guix weather}).
12439 As a bonus, @command{guix publish} also serves as a content-addressed
12440 mirror for source files referenced in @code{origin} records
12441 (@pxref{origin Reference}). For instance, assuming @command{guix
12442 publish} is running on @code{example.org}, the following URL returns the
12443 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
12444 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
12447 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
12450 Obviously, these URLs only work for files that are in the store; in
12451 other cases, they return 404 (``Not Found'').
12453 @cindex build logs, publication
12454 Build logs are available from @code{/log} URLs like:
12457 http://example.org/log/gwspk@dots{}-guile-2.2.3
12461 When @command{guix-daemon} is configured to save compressed build logs,
12462 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
12463 URLs return the compressed log as-is, with an appropriate
12464 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
12465 running @command{guix-daemon} with @option{--log-compression=gzip} since
12466 Web browsers can automatically decompress it, which is not the case with
12469 The following options are available:
12472 @item --port=@var{port}
12473 @itemx -p @var{port}
12474 Listen for HTTP requests on @var{port}.
12476 @item --listen=@var{host}
12477 Listen on the network interface for @var{host}. The default is to
12478 accept connections from any interface.
12480 @item --user=@var{user}
12481 @itemx -u @var{user}
12482 Change privileges to @var{user} as soon as possible---i.e., once the
12483 server socket is open and the signing key has been read.
12485 @item --compression[=@var{method}[:@var{level}]]
12486 @itemx -C [@var{method}[:@var{level}]]
12487 Compress data using the given @var{method} and @var{level}. @var{method} is
12488 one of @code{lzip}, @code{zstd}, and @code{gzip}; when @var{method} is
12489 omitted, @code{gzip} is used.
12491 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
12492 to different compression levels: 1 is the fastest, and 9 is the best
12493 (CPU-intensive). The default is 3.
12495 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a
12496 small increase in CPU usage; see
12497 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip
12498 Web page}. However, @code{lzip} achieves low decompression throughput
12499 (on the order of 50@tie{}MiB/s on modern hardware), which can be a
12500 bottleneck for someone who downloads over a fast network connection.
12502 The compression ratio of @code{zstd} is between that of @code{lzip} and
12503 that of @code{gzip}; its main advantage is a
12504 @uref{https://facebook.github.io/zstd/,high decompression speed}.
12506 Unless @option{--cache} is used, compression occurs on the fly and
12507 the compressed streams are not
12508 cached. Thus, to reduce load on the machine that runs @command{guix
12509 publish}, it may be a good idea to choose a low compression level, to
12510 run @command{guix publish} behind a caching proxy, or to use
12511 @option{--cache}. Using @option{--cache} has the advantage that it
12512 allows @command{guix publish} to add @code{Content-Length} HTTP header
12515 This option can be repeated, in which case every substitute gets compressed
12516 using all the selected methods, and all of them are advertised. This is
12517 useful when users may not support all the compression methods: they can select
12518 the one they support.
12520 @item --cache=@var{directory}
12521 @itemx -c @var{directory}
12522 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
12523 and only serve archives that are in cache.
12525 When this option is omitted, archives and meta-data are created
12526 on-the-fly. This can reduce the available bandwidth, especially when
12527 compression is enabled, since this may become CPU-bound. Another
12528 drawback of the default mode is that the length of archives is not known
12529 in advance, so @command{guix publish} does not add a
12530 @code{Content-Length} HTTP header to its responses, which in turn
12531 prevents clients from knowing the amount of data being downloaded.
12533 Conversely, when @option{--cache} is used, the first request for a store
12534 item (@i{via} a @code{.narinfo} URL) triggers a
12535 background process to @dfn{bake} the archive---computing its
12536 @code{.narinfo} and compressing the archive, if needed. Once the
12537 archive is cached in @var{directory}, subsequent requests succeed and
12538 are served directly from the cache, which guarantees that clients get
12539 the best possible bandwidth.
12541 That first @code{.narinfo} request nonetheless returns 200, provided the
12542 requested store item is ``small enough'', below the cache bypass
12543 threshold---see @option{--cache-bypass-threshold} below. That way,
12544 clients do not have to wait until the archive is baked. For larger
12545 store items, the first @code{.narinfo} request returns 404, meaning that
12546 clients have to wait until the archive is baked.
12548 The ``baking'' process is performed by worker threads. By default, one
12549 thread per CPU core is created, but this can be customized. See
12550 @option{--workers} below.
12552 When @option{--ttl} is used, cached entries are automatically deleted
12553 when they have expired.
12555 @item --workers=@var{N}
12556 When @option{--cache} is used, request the allocation of @var{N} worker
12557 threads to ``bake'' archives.
12559 @item --ttl=@var{ttl}
12560 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
12561 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
12562 days, @code{1m} means 1 month, and so on.
12564 This allows the user's Guix to keep substitute information in cache for
12565 @var{ttl}. However, note that @code{guix publish} does not itself
12566 guarantee that the store items it provides will indeed remain available
12567 for as long as @var{ttl}.
12569 Additionally, when @option{--cache} is used, cached entries that have
12570 not been accessed for @var{ttl} and that no longer have a corresponding
12571 item in the store, may be deleted.
12573 @item --cache-bypass-threshold=@var{size}
12574 When used in conjunction with @option{--cache}, store items smaller than
12575 @var{size} are immediately available, even when they are not yet in
12576 cache. @var{size} is a size in bytes, or it can be suffixed by @code{M}
12577 for megabytes and so on. The default is @code{10M}.
12579 ``Cache bypass'' allows you to reduce the publication delay for clients
12580 at the expense of possibly additional I/O and CPU use on the server
12581 side: depending on the client access patterns, those store items can end
12582 up being baked several times until a copy is available in cache.
12584 Increasing the threshold may be useful for sites that have few users, or
12585 to guarantee that users get substitutes even for store items that are
12588 @item --nar-path=@var{path}
12589 Use @var{path} as the prefix for the URLs of ``nar'' files
12590 (@pxref{Invoking guix archive, normalized archives}).
12592 By default, nars are served at a URL such as
12593 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
12594 change the @code{/nar} part to @var{path}.
12596 @item --public-key=@var{file}
12597 @itemx --private-key=@var{file}
12598 Use the specific @var{file}s as the public/private key pair used to sign
12599 the store items being published.
12601 The files must correspond to the same key pair (the private key is used
12602 for signing and the public key is merely advertised in the signature
12603 metadata). They must contain keys in the canonical s-expression format
12604 as produced by @command{guix archive --generate-key} (@pxref{Invoking
12605 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
12606 @file{/etc/guix/signing-key.sec} are used.
12608 @item --repl[=@var{port}]
12609 @itemx -r [@var{port}]
12610 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
12611 Reference Manual}) on @var{port} (37146 by default). This is used
12612 primarily for debugging a running @command{guix publish} server.
12615 Enabling @command{guix publish} on Guix System is a one-liner: just
12616 instantiate a @code{guix-publish-service-type} service in the @code{services} field
12617 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
12618 @code{guix-publish-service-type}}).
12620 If you are instead running Guix on a ``foreign distro'', follow these
12625 If your host distro uses the systemd init system:
12628 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
12629 /etc/systemd/system/
12630 # systemctl start guix-publish && systemctl enable guix-publish
12634 If your host distro uses the Upstart init system:
12637 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
12638 # start guix-publish
12642 Otherwise, proceed similarly with your distro's init system.
12645 @node Invoking guix challenge
12646 @section Invoking @command{guix challenge}
12648 @cindex reproducible builds
12649 @cindex verifiable builds
12650 @cindex @command{guix challenge}
12652 Do the binaries provided by this server really correspond to the source
12653 code it claims to build? Is a package build process deterministic?
12654 These are the questions the @command{guix challenge} command attempts to
12657 The former is obviously an important question: Before using a substitute
12658 server (@pxref{Substitutes}), one had better @emph{verify} that it
12659 provides the right binaries, and thus @emph{challenge} it. The latter
12660 is what enables the former: If package builds are deterministic, then
12661 independent builds of the package should yield the exact same result,
12662 bit for bit; if a server provides a binary different from the one
12663 obtained locally, it may be either corrupt or malicious.
12665 We know that the hash that shows up in @file{/gnu/store} file names is
12666 the hash of all the inputs of the process that built the file or
12667 directory---compilers, libraries, build scripts,
12668 etc. (@pxref{Introduction}). Assuming deterministic build processes,
12669 one store file name should map to exactly one build output.
12670 @command{guix challenge} checks whether there is, indeed, a single
12671 mapping by comparing the build outputs of several independent builds of
12672 any given store item.
12674 The command output looks like this:
12677 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
12678 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
12679 updating list of substitutes from 'https://guix.example.org'... 100.0%
12680 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
12681 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
12682 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
12683 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
12685 /lib/libcrypto.so.1.1
12688 /gnu/store/@dots{}-git-2.5.0 contents differ:
12689 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
12690 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
12691 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
12693 /libexec/git-core/git-fsck
12695 /gnu/store/@dots{}-pius-2.1.1 contents differ:
12696 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
12697 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
12698 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
12700 /share/man/man1/pius.1.gz
12704 6,406 store items were analyzed:
12705 - 4,749 (74.1%) were identical
12706 - 525 (8.2%) differed
12707 - 1,132 (17.7%) were inconclusive
12711 In this example, @command{guix challenge} first scans the store to
12712 determine the set of locally-built derivations---as opposed to store
12713 items that were downloaded from a substitute server---and then queries
12714 all the substitute servers. It then reports those store items for which
12715 the servers obtained a result different from the local build.
12717 @cindex non-determinism, in package builds
12718 As an example, @code{guix.example.org} always gets a different answer.
12719 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
12720 case of Git. This might indicate that the build process of Git is
12721 non-deterministic, meaning that its output varies as a function of
12722 various things that Guix does not fully control, in spite of building
12723 packages in isolated environments (@pxref{Features}). Most common
12724 sources of non-determinism include the addition of timestamps in build
12725 results, the inclusion of random numbers, and directory listings sorted
12726 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
12729 To find out what is wrong with this Git binary, the easiest approach is
12733 guix challenge git \
12734 --diff=diffoscope \
12735 --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
12738 This automatically invokes @command{diffoscope}, which displays detailed
12739 information about files that differ.
12741 Alternatively, we can do something along these lines (@pxref{Invoking guix
12745 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-git-2.5.0 \
12746 | lzip -d | guix archive -x /tmp/git
12747 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
12750 This command shows the difference between the files resulting from the
12751 local build, and the files resulting from the build on
12752 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
12753 diffutils, Comparing and Merging Files}). The @command{diff} command
12754 works great for text files. When binary files differ, a better option
12755 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
12756 visualize differences for all kinds of files.
12758 Once you have done that work, you can tell whether the differences are due
12759 to a non-deterministic build process or to a malicious server. We try
12760 hard to remove sources of non-determinism in packages to make it easier
12761 to verify substitutes, but of course, this is a process that
12762 involves not just Guix, but a large part of the free software community.
12763 In the meantime, @command{guix challenge} is one tool to help address
12766 If you are writing packages for Guix, you are encouraged to check
12767 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
12768 same build result as you did with:
12771 $ guix challenge @var{package}
12775 where @var{package} is a package specification such as
12776 @code{guile@@2.0} or @code{glibc:debug}.
12778 The general syntax is:
12781 guix challenge @var{options} [@var{packages}@dots{}]
12784 When a difference is found between the hash of a locally-built item and
12785 that of a server-provided substitute, or among substitutes provided by
12786 different servers, the command displays it as in the example above and
12787 its exit code is 2 (other non-zero exit codes denote other kinds of
12790 The one option that matters is:
12794 @item --substitute-urls=@var{urls}
12795 Consider @var{urls} the whitespace-separated list of substitute source
12796 URLs to compare to.
12798 @item --diff=@var{mode}
12799 Upon mismatches, show differences according to @var{mode}, one of:
12802 @item @code{simple} (the default)
12803 Show the list of files that differ.
12805 @item @code{diffoscope}
12806 @itemx @var{command}
12807 Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
12808 two directories whose contents do not match.
12810 When @var{command} is an absolute file name, run @var{command} instead
12814 Do not show further details about the differences.
12817 Thus, unless @option{--diff=none} is passed, @command{guix challenge}
12818 downloads the store items from the given substitute servers so that it
12823 Show details about matches (identical contents) in addition to
12824 information about mismatches.
12828 @node Invoking guix copy
12829 @section Invoking @command{guix copy}
12831 @cindex copy, of store items, over SSH
12832 @cindex SSH, copy of store items
12833 @cindex sharing store items across machines
12834 @cindex transferring store items across machines
12835 The @command{guix copy} command copies items from the store of one
12836 machine to that of another machine over a secure shell (SSH)
12837 connection@footnote{This command is available only when Guile-SSH was
12838 found. @xref{Requirements}, for details.}. For example, the following
12839 command copies the @code{coreutils} package, the user's profile, and all
12840 their dependencies over to @var{host}, logged in as @var{user}:
12843 guix copy --to=@var{user}@@@var{host} \
12844 coreutils `readlink -f ~/.guix-profile`
12847 If some of the items to be copied are already present on @var{host},
12848 they are not actually sent.
12850 The command below retrieves @code{libreoffice} and @code{gimp} from
12851 @var{host}, assuming they are available there:
12854 guix copy --from=@var{host} libreoffice gimp
12857 The SSH connection is established using the Guile-SSH client, which is
12858 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
12859 @file{~/.ssh/config}, and uses the SSH agent for authentication.
12861 The key used to sign items that are sent must be accepted by the remote
12862 machine. Likewise, the key used by the remote machine to sign items you
12863 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
12864 own daemon. @xref{Invoking guix archive}, for more information about
12865 store item authentication.
12867 The general syntax is:
12870 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
12873 You must always specify one of the following options:
12876 @item --to=@var{spec}
12877 @itemx --from=@var{spec}
12878 Specify the host to send to or receive from. @var{spec} must be an SSH
12879 spec such as @code{example.org}, @code{charlie@@example.org}, or
12880 @code{charlie@@example.org:2222}.
12883 The @var{items} can be either package names, such as @code{gimp}, or
12884 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
12886 When specifying the name of a package to send, it is first built if
12887 needed, unless @option{--dry-run} was specified. Common build options
12888 are supported (@pxref{Common Build Options}).
12891 @node Invoking guix container
12892 @section Invoking @command{guix container}
12894 @cindex @command{guix container}
12896 As of version @value{VERSION}, this tool is experimental. The interface
12897 is subject to radical change in the future.
12900 The purpose of @command{guix container} is to manipulate processes
12901 running within an isolated environment, commonly known as a
12902 ``container'', typically created by the @command{guix environment}
12903 (@pxref{Invoking guix environment}) and @command{guix system container}
12904 (@pxref{Invoking guix system}) commands.
12906 The general syntax is:
12909 guix container @var{action} @var{options}@dots{}
12912 @var{action} specifies the operation to perform with a container, and
12913 @var{options} specifies the context-specific arguments for the action.
12915 The following actions are available:
12919 Execute a command within the context of a running container.
12924 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
12927 @var{pid} specifies the process ID of the running container.
12928 @var{program} specifies an executable file name within the root file
12929 system of the container. @var{arguments} are the additional options that
12930 will be passed to @var{program}.
12932 The following command launches an interactive login shell inside a
12933 Guix system container, started by @command{guix system container}, and whose
12934 process ID is 9001:
12937 guix container exec 9001 /run/current-system/profile/bin/bash --login
12940 Note that the @var{pid} cannot be the parent process of a container. It
12941 must be PID 1 of the container or one of its child processes.
12945 @node Invoking guix weather
12946 @section Invoking @command{guix weather}
12948 Occasionally you're grumpy because substitutes are lacking and you end
12949 up building packages by yourself (@pxref{Substitutes}). The
12950 @command{guix weather} command reports on substitute availability on the
12951 specified servers so you can have an idea of whether you'll be grumpy
12952 today. It can sometimes be useful info as a user, but it is primarily
12953 useful to people running @command{guix publish} (@pxref{Invoking guix
12956 @cindex statistics, for substitutes
12957 @cindex availability of substitutes
12958 @cindex substitute availability
12959 @cindex weather, substitute availability
12960 Here's a sample run:
12963 $ guix weather --substitute-urls=https://guix.example.org
12964 computing 5,872 package derivations for x86_64-linux...
12965 looking for 6,128 store items on https://guix.example.org..
12966 updating list of substitutes from 'https://guix.example.org'... 100.0%
12967 https://guix.example.org
12968 43.4% substitutes available (2,658 out of 6,128)
12969 7,032.5 MiB of nars (compressed)
12970 19,824.2 MiB on disk (uncompressed)
12971 0.030 seconds per request (182.9 seconds in total)
12972 33.5 requests per second
12974 9.8% (342 out of 3,470) of the missing items are queued
12976 x86_64-linux: 518 (59.7%)
12977 i686-linux: 221 (25.5%)
12978 aarch64-linux: 128 (14.8%)
12979 build rate: 23.41 builds per hour
12980 x86_64-linux: 11.16 builds per hour
12981 i686-linux: 6.03 builds per hour
12982 aarch64-linux: 6.41 builds per hour
12985 @cindex continuous integration, statistics
12986 As you can see, it reports the fraction of all the packages for which
12987 substitutes are available on the server---regardless of whether
12988 substitutes are enabled, and regardless of whether this server's signing
12989 key is authorized. It also reports the size of the compressed archives
12990 (``nars'') provided by the server, the size the corresponding store
12991 items occupy in the store (assuming deduplication is turned off), and
12992 the server's throughput. The second part gives continuous integration
12993 (CI) statistics, if the server supports it. In addition, using the
12994 @option{--coverage} option, @command{guix weather} can list ``important''
12995 package substitutes missing on the server (see below).
12997 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
12998 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
12999 challenge}, it ignores signatures on those substitutes, which is
13000 innocuous since the command only gathers statistics and cannot install
13003 The general syntax is:
13006 guix weather @var{options}@dots{} [@var{packages}@dots{}]
13009 When @var{packages} is omitted, @command{guix weather} checks the availability
13010 of substitutes for @emph{all} the packages, or for those specified with
13011 @option{--manifest}; otherwise it only considers the specified packages. It
13012 is also possible to query specific system types with @option{--system}.
13013 @command{guix weather} exits with a non-zero code when the fraction of
13014 available substitutes is below 100%.
13016 The available options are listed below.
13019 @item --substitute-urls=@var{urls}
13020 @var{urls} is the space-separated list of substitute server URLs to
13021 query. When this option is omitted, the default set of substitute
13022 servers is queried.
13024 @item --system=@var{system}
13025 @itemx -s @var{system}
13026 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
13027 option can be repeated, in which case @command{guix weather} will query
13028 substitutes for several system types.
13030 @item --manifest=@var{file}
13031 Instead of querying substitutes for all the packages, only ask for those
13032 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
13033 with the @code{-m} option of @command{guix package} (@pxref{Invoking
13036 This option can be repeated several times, in which case the manifests
13039 @item --coverage[=@var{count}]
13040 @itemx -c [@var{count}]
13041 Report on substitute coverage for packages: list packages with at least
13042 @var{count} dependents (zero by default) for which substitutes are
13043 unavailable. Dependent packages themselves are not listed: if @var{b} depends
13044 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
13045 @var{b} usually lacks substitutes as well. The result looks like this:
13048 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
13049 computing 8,983 package derivations for x86_64-linux...
13050 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
13051 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
13052 @value{SUBSTITUTE-URL}
13053 64.7% substitutes available (6,047 out of 9,343)
13055 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
13056 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
13057 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
13058 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
13062 What this example shows is that @code{kcoreaddons} and presumably the 58
13063 packages that depend on it have no substitutes at
13064 @code{@value{SUBSTITUTE-SERVER}}; likewise for @code{qgpgme} and the 46
13065 packages that depend on it.
13067 If you are a Guix developer, or if you are taking care of this build farm,
13068 you'll probably want to have a closer look at these packages: they may simply
13071 @item --display-missing
13072 Display the list of store items for which substitutes are missing.
13075 @node Invoking guix processes
13076 @section Invoking @command{guix processes}
13078 The @command{guix processes} command can be useful to developers and system
13079 administrators, especially on multi-user machines and on build farms: it lists
13080 the current sessions (connections to the daemon), as well as information about
13081 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
13082 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
13083 listed.}. Here's an example of the information it returns:
13086 $ sudo guix processes
13089 ClientCommand: guix environment --ad-hoc python
13093 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
13097 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
13098 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
13099 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
13100 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
13102 ChildCommand: guix offload x86_64-linux 7200 1 28800
13104 ChildCommand: guix offload x86_64-linux 7200 1 28800
13106 ChildCommand: guix offload x86_64-linux 7200 1 28800
13109 In this example we see that @command{guix-daemon} has three clients:
13110 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
13111 integration tool; their process identifier (PID) is given by the
13112 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
13113 @command{guix-daemon} sub-process of this particular session.
13115 The @code{LockHeld} fields show which store items are currently locked
13116 by this session, which corresponds to store items being built or
13117 substituted (the @code{LockHeld} field is not displayed when
13118 @command{guix processes} is not running as root). Last, by looking at
13119 the @code{ChildPID} and @code{ChildCommand} fields, we understand that
13120 these three builds are being offloaded (@pxref{Daemon Offload Setup}).
13122 The output is in Recutils format so we can use the handy @command{recsel}
13123 command to select sessions of interest (@pxref{Selection Expressions,,,
13124 recutils, GNU recutils manual}). As an example, the command shows the command
13125 line and PID of the client that triggered the build of a Perl package:
13128 $ sudo guix processes | \
13129 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
13131 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
13134 Additional options are listed below.
13137 @item --format=@var{format}
13138 @itemx -f @var{format}
13139 Produce output in the specified @var{format}, one of:
13143 The default option. It outputs a set of Session recutils records
13144 that include each @code{ChildProcess} as a field.
13147 Normalize the output records into record sets (@pxref{Record Sets,,,
13148 recutils, GNU recutils manual}). Normalizing into record sets allows
13149 joins across record types. The example below lists the PID of each
13150 @code{ChildProcess} and the associated PID for @code{Session} that
13151 spawned the @code{ChildProcess} where the @code{Session} was started
13152 using @command{guix build}.
13155 $ guix processes --format=normalized | \
13159 -p Session.PID,PID \
13160 -e 'Session.ClientCommand ~ "guix build"'
13173 @node System Configuration
13174 @chapter System Configuration
13176 @cindex system configuration
13177 Guix System supports a consistent whole-system configuration
13178 mechanism. By that we mean that all aspects of the global system
13179 configuration---such as the available system services, timezone and
13180 locale settings, user accounts---are declared in a single place. Such
13181 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
13183 One of the advantages of putting all the system configuration under the
13184 control of Guix is that it supports transactional system upgrades, and
13185 makes it possible to roll back to a previous system instantiation,
13186 should something go wrong with the new one (@pxref{Features}). Another
13187 advantage is that it makes it easy to replicate the exact same configuration
13188 across different machines, or at different points in time, without
13189 having to resort to additional administration tools layered on top of
13190 the own tools of the system.
13191 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
13193 This section describes this mechanism. First we focus on the system
13194 administrator's viewpoint---explaining how the system is configured and
13195 instantiated. Then we show how this mechanism can be extended, for
13196 instance to support new system services.
13199 * Using the Configuration System:: Customizing your GNU system.
13200 * operating-system Reference:: Detail of operating-system declarations.
13201 * File Systems:: Configuring file system mounts.
13202 * Mapped Devices:: Block device extra processing.
13203 * User Accounts:: Specifying user accounts.
13204 * Keyboard Layout:: How the system interprets key strokes.
13205 * Locales:: Language and cultural convention settings.
13206 * Services:: Specifying system services.
13207 * Setuid Programs:: Programs running with root privileges.
13208 * X.509 Certificates:: Authenticating HTTPS servers.
13209 * Name Service Switch:: Configuring libc's name service switch.
13210 * Initial RAM Disk:: Linux-Libre bootstrapping.
13211 * Bootloader Configuration:: Configuring the boot loader.
13212 * Invoking guix system:: Instantiating a system configuration.
13213 * Invoking guix deploy:: Deploying a system configuration to a remote host.
13214 * Running Guix in a VM:: How to run Guix System in a virtual machine.
13215 * Defining Services:: Adding new service definitions.
13218 @node Using the Configuration System
13219 @section Using the Configuration System
13221 The operating system is configured by providing an
13222 @code{operating-system} declaration in a file that can then be passed to
13223 the @command{guix system} command (@pxref{Invoking guix system}). A
13224 simple setup, with the default system services, the default Linux-Libre
13225 kernel, initial RAM disk, and boot loader looks like this:
13227 @findex operating-system
13229 @include os-config-bare-bones.texi
13232 This example should be self-describing. Some of the fields defined
13233 above, such as @code{host-name} and @code{bootloader}, are mandatory.
13234 Others, such as @code{packages} and @code{services}, can be omitted, in
13235 which case they get a default value.
13237 Below we discuss the effect of some of the most important fields
13238 (@pxref{operating-system Reference}, for details about all the available
13239 fields), and how to @dfn{instantiate} the operating system using
13240 @command{guix system}.
13242 @unnumberedsubsec Bootloader
13244 @cindex legacy boot, on Intel machines
13245 @cindex BIOS boot, on Intel machines
13248 The @code{bootloader} field describes the method that will be used to boot
13249 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
13250 mode, as in the example above. However, more recent machines rely instead on
13251 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
13252 the @code{bootloader} field should contain something along these lines:
13255 (bootloader-configuration
13256 (bootloader grub-efi-bootloader)
13257 (target "/boot/efi"))
13260 @xref{Bootloader Configuration}, for more information on the available
13261 configuration options.
13263 @unnumberedsubsec Globally-Visible Packages
13265 @vindex %base-packages
13266 The @code{packages} field lists packages that will be globally visible
13267 on the system, for all user accounts---i.e., in every user's @env{PATH}
13268 environment variable---in addition to the per-user profiles
13269 (@pxref{Invoking guix package}). The @code{%base-packages} variable
13270 provides all the tools one would expect for basic user and administrator
13271 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
13272 the GNU Zile lightweight text editor, @command{find}, @command{grep},
13273 etc. The example above adds GNU@tie{}Screen to those,
13274 taken from the @code{(gnu packages screen)}
13275 module (@pxref{Package Modules}). The
13276 @code{(list package output)} syntax can be used to add a specific output
13280 (use-modules (gnu packages))
13281 (use-modules (gnu packages dns))
13285 (packages (cons (list bind "utils")
13289 @findex specification->package
13290 Referring to packages by variable name, like @code{bind} above, has
13291 the advantage of being unambiguous; it also allows typos and such to be
13292 diagnosed right away as ``unbound variables''. The downside is that one
13293 needs to know which module defines which package, and to augment the
13294 @code{use-package-modules} line accordingly. To avoid that, one can use
13295 the @code{specification->package} procedure of the @code{(gnu packages)}
13296 module, which returns the best package for a given name or name and
13300 (use-modules (gnu packages))
13304 (packages (append (map specification->package
13305 '("tcpdump" "htop" "gnupg@@2.0"))
13309 @unnumberedsubsec System Services
13312 @vindex %base-services
13313 The @code{services} field lists @dfn{system services} to be made
13314 available when the system starts (@pxref{Services}).
13315 The @code{operating-system} declaration above specifies that, in
13316 addition to the basic services, we want the OpenSSH secure shell
13317 daemon listening on port 2222 (@pxref{Networking Services,
13318 @code{openssh-service-type}}). Under the hood,
13319 @code{openssh-service-type} arranges so that @command{sshd} is started with the
13320 right command-line options, possibly with supporting configuration files
13321 generated as needed (@pxref{Defining Services}).
13323 @cindex customization, of services
13324 @findex modify-services
13325 Occasionally, instead of using the base services as is, you will want to
13326 customize them. To do this, use @code{modify-services} (@pxref{Service
13327 Reference, @code{modify-services}}) to modify the list.
13329 For example, suppose you want to modify @code{guix-daemon} and Mingetty
13330 (the console log-in) in the @code{%base-services} list (@pxref{Base
13331 Services, @code{%base-services}}). To do that, you can write the
13332 following in your operating system declaration:
13335 (define %my-services
13336 ;; My very own list of services.
13337 (modify-services %base-services
13338 (guix-service-type config =>
13339 (guix-configuration
13341 ;; Fetch substitutes from example.org.
13343 (list "https://example.org/guix"
13344 "https://ci.guix.gnu.org"))))
13345 (mingetty-service-type config =>
13346 (mingetty-configuration
13348 ;; Automatially log in as "guest".
13349 (auto-login "guest")))))
13353 (services %my-services))
13356 This changes the configuration---i.e., the service parameters---of the
13357 @code{guix-service-type} instance, and that of all the
13358 @code{mingetty-service-type} instances in the @code{%base-services} list.
13359 Observe how this is accomplished: first, we arrange for the original
13360 configuration to be bound to the identifier @code{config} in the
13361 @var{body}, and then we write the @var{body} so that it evaluates to the
13362 desired configuration. In particular, notice how we use @code{inherit}
13363 to create a new configuration which has the same values as the old
13364 configuration, but with a few modifications.
13366 @cindex encrypted disk
13367 The configuration for a typical ``desktop'' usage, with an encrypted
13368 root partition, the X11 display
13369 server, GNOME and Xfce (users can choose which of these desktop
13370 environments to use at the log-in screen by pressing @kbd{F1}), network
13371 management, power management, and more, would look like this:
13374 @include os-config-desktop.texi
13377 A graphical system with a choice of lightweight window managers
13378 instead of full-blown desktop environments would look like this:
13381 @include os-config-lightweight-desktop.texi
13384 This example refers to the @file{/boot/efi} file system by its UUID,
13385 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
13386 as returned by the @command{blkid} command.
13388 @xref{Desktop Services}, for the exact list of services provided by
13389 @code{%desktop-services}. @xref{X.509 Certificates}, for background
13390 information about the @code{nss-certs} package that is used here.
13392 Again, @code{%desktop-services} is just a list of service objects. If
13393 you want to remove services from there, you can do so using the
13394 procedures for list filtering (@pxref{SRFI-1 Filtering and
13395 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
13396 following expression returns a list that contains all the services in
13397 @code{%desktop-services} minus the Avahi service:
13400 (remove (lambda (service)
13401 (eq? (service-kind service) avahi-service-type))
13405 @unnumberedsubsec Instantiating the System
13407 Assuming the @code{operating-system} declaration
13408 is stored in the @file{my-system-config.scm}
13409 file, the @command{guix system reconfigure my-system-config.scm} command
13410 instantiates that configuration, and makes it the default GRUB boot
13411 entry (@pxref{Invoking guix system}).
13413 The normal way to change the system configuration is by updating this
13414 file and re-running @command{guix system reconfigure}. One should never
13415 have to touch files in @file{/etc} or to run commands that modify the
13416 system state such as @command{useradd} or @command{grub-install}. In
13417 fact, you must avoid that since that would not only void your warranty
13418 but also prevent you from rolling back to previous versions of your
13419 system, should you ever need to.
13421 @cindex roll-back, of the operating system
13422 Speaking of roll-back, each time you run @command{guix system
13423 reconfigure}, a new @dfn{generation} of the system is created---without
13424 modifying or deleting previous generations. Old system generations get
13425 an entry in the bootloader boot menu, allowing you to boot them in case
13426 something went wrong with the latest generation. Reassuring, no? The
13427 @command{guix system list-generations} command lists the system
13428 generations available on disk. It is also possible to roll back the
13429 system via the commands @command{guix system roll-back} and
13430 @command{guix system switch-generation}.
13432 Although the @command{guix system reconfigure} command will not modify
13433 previous generations, you must take care when the current generation is not
13434 the latest (e.g., after invoking @command{guix system roll-back}), since
13435 the operation might overwrite a later generation (@pxref{Invoking guix
13438 @unnumberedsubsec The Programming Interface
13440 At the Scheme level, the bulk of an @code{operating-system} declaration
13441 is instantiated with the following monadic procedure (@pxref{The Store
13444 @deffn {Monadic Procedure} operating-system-derivation os
13445 Return a derivation that builds @var{os}, an @code{operating-system}
13446 object (@pxref{Derivations}).
13448 The output of the derivation is a single directory that refers to all
13449 the packages, configuration files, and other supporting files needed to
13450 instantiate @var{os}.
13453 This procedure is provided by the @code{(gnu system)} module. Along
13454 with @code{(gnu services)} (@pxref{Services}), this module contains the
13455 guts of Guix System. Make sure to visit it!
13458 @node operating-system Reference
13459 @section @code{operating-system} Reference
13461 This section summarizes all the options available in
13462 @code{operating-system} declarations (@pxref{Using the Configuration
13465 @deftp {Data Type} operating-system
13466 This is the data type representing an operating system configuration.
13467 By that, we mean all the global system configuration, not per-user
13468 configuration (@pxref{Using the Configuration System}).
13471 @item @code{kernel} (default: @code{linux-libre})
13472 The package object of the operating system kernel to
13473 use@footnote{Currently only the Linux-libre kernel is fully supported.
13474 Using GNU@tie{}mach with the GNU@tie{}Hurd is experimental and only
13475 available when building a virtual machine disk image.}.
13478 @item @code{hurd} (default: @code{#f})
13479 The package object of the Hurd to be started by the kernel. When this
13480 field is set, produce a GNU/Hurd operating system. In that case,
13481 @code{kernel} must also be set to the @code{gnumach} package---the
13482 microkernel the Hurd runs on.
13485 This feature is experimental and only supported for disk images.
13488 @item @code{kernel-loadable-modules} (default: '())
13489 A list of objects (usually packages) to collect loadable kernel modules
13490 from--e.g. @code{(list ddcci-driver-linux)}.
13492 @item @code{kernel-arguments} (default: @code{%default-kernel-arguments})
13493 List of strings or gexps representing additional arguments to pass on
13494 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
13496 @item @code{bootloader}
13497 The system bootloader configuration object. @xref{Bootloader Configuration}.
13500 This is the label (a string) as it appears in the bootloader's menu entry.
13501 The default label includes the kernel name and version.
13503 @item @code{keyboard-layout} (default: @code{#f})
13504 This field specifies the keyboard layout to use in the console. It can be
13505 either @code{#f}, in which case the default keyboard layout is used (usually
13506 US English), or a @code{<keyboard-layout>} record. @xref{Keyboard Layout},
13507 for more information.
13509 This keyboard layout is in effect as soon as the kernel has booted. For
13510 instance, it is the keyboard layout in effect when you type a passphrase if
13511 your root file system is on a @code{luks-device-mapping} mapped device
13512 (@pxref{Mapped Devices}).
13515 This does @emph{not} specify the keyboard layout used by the bootloader, nor
13516 that used by the graphical display server. @xref{Bootloader Configuration},
13517 for information on how to specify the bootloader's keyboard layout. @xref{X
13518 Window}, for information on how to specify the keyboard layout used by the X
13522 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
13524 @cindex initial RAM disk
13525 The list of Linux kernel modules that need to be available in the
13526 initial RAM disk. @xref{Initial RAM Disk}.
13528 @item @code{initrd} (default: @code{base-initrd})
13529 A procedure that returns an initial RAM disk for the Linux
13530 kernel. This field is provided to support low-level customization and
13531 should rarely be needed for casual use. @xref{Initial RAM Disk}.
13533 @item @code{firmware} (default: @code{%base-firmware})
13535 List of firmware packages loadable by the operating system kernel.
13537 The default includes firmware needed for Atheros- and Broadcom-based
13538 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
13539 respectively). @xref{Hardware Considerations}, for more info on
13540 supported hardware.
13542 @item @code{host-name}
13545 @item @code{hosts-file}
13547 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
13548 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
13549 Reference Manual}). The default is a file with entries for
13550 @code{localhost} and @var{host-name}.
13552 @item @code{mapped-devices} (default: @code{'()})
13553 A list of mapped devices. @xref{Mapped Devices}.
13555 @item @code{file-systems}
13556 A list of file systems. @xref{File Systems}.
13558 @cindex swap devices
13560 @item @code{swap-devices} (default: @code{'()})
13561 A list of UUIDs, file system labels, or strings identifying devices or
13562 files to be used for ``swap
13563 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
13564 Manual}). Here are some examples:
13567 @item (list (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb"))
13568 Use the swap partition with the given UUID@. You can learn the UUID of a
13569 Linux swap partition by running @command{swaplabel @var{device}}, where
13570 @var{device} is the @file{/dev} file name of that partition.
13572 @item (list (file-system-label "swap"))
13573 Use the partition with label @code{swap}. Again, the
13574 @command{swaplabel} command allows you to view and change the label of a
13575 Linux swap partition.
13577 @item (list "/swapfile")
13578 Use the file @file{/swapfile} as swap space.
13580 @item (list "/dev/sda3" "/dev/sdb2")
13581 Use the @file{/dev/sda3} and @file{/dev/sdb2} partitions as swap space.
13582 We recommend referring to swap devices by UUIDs or labels as shown above
13586 It is possible to specify a swap file in a file system on a mapped
13587 device (under @file{/dev/mapper}), provided that the necessary device
13588 mapping and file system are also specified. @xref{Mapped Devices} and
13589 @ref{File Systems}.
13591 @item @code{users} (default: @code{%base-user-accounts})
13592 @itemx @code{groups} (default: @code{%base-groups})
13593 List of user accounts and groups. @xref{User Accounts}.
13595 If the @code{users} list lacks a user account with UID@tie{}0, a
13596 ``root'' account with UID@tie{}0 is automatically added.
13598 @item @code{skeletons} (default: @code{(default-skeletons)})
13599 A list of target file name/file-like object tuples (@pxref{G-Expressions,
13600 file-like objects}). These are the skeleton files that will be added to
13601 the home directory of newly-created user accounts.
13603 For instance, a valid value may look like this:
13606 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
13607 (".guile" ,(plain-file "guile"
13608 "(use-modules (ice-9 readline))
13609 (activate-readline)")))
13612 @item @code{issue} (default: @code{%default-issue})
13613 A string denoting the contents of the @file{/etc/issue} file, which is
13614 displayed when users log in on a text console.
13616 @item @code{packages} (default: @code{%base-packages})
13617 A list of packages to be installed in the global profile, which is accessible
13618 at @file{/run/current-system/profile}. Each element is either a package
13619 variable or a package/output tuple. Here's a simple example of both:
13622 (cons* git ; the default "out" output
13623 (list git "send-email") ; another output of git
13624 %base-packages) ; the default set
13627 The default set includes core utilities and it is good practice to
13628 install non-core utilities in user profiles (@pxref{Invoking guix
13631 @item @code{timezone}
13632 A timezone identifying string---e.g., @code{"Europe/Paris"}.
13634 You can run the @command{tzselect} command to find out which timezone
13635 string corresponds to your region. Choosing an invalid timezone name
13636 causes @command{guix system} to fail.
13638 @item @code{locale} (default: @code{"en_US.utf8"})
13639 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
13640 Library Reference Manual}). @xref{Locales}, for more information.
13642 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
13643 The list of locale definitions to be compiled and that may be used at
13644 run time. @xref{Locales}.
13646 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
13647 The list of GNU@tie{}libc packages whose locale data and tools are used
13648 to build the locale definitions. @xref{Locales}, for compatibility
13649 considerations that justify this option.
13651 @item @code{name-service-switch} (default: @code{%default-nss})
13652 Configuration of the libc name service switch (NSS)---a
13653 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
13656 @item @code{services} (default: @code{%base-services})
13657 A list of service objects denoting system services. @xref{Services}.
13659 @cindex essential services
13660 @item @code{essential-services} (default: ...)
13661 The list of ``essential services''---i.e., things like instances of
13662 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
13663 Reference}), which are derived from the operating system definition itself.
13664 As a user you should @emph{never} need to touch this field.
13666 @item @code{pam-services} (default: @code{(base-pam-services)})
13668 @cindex pluggable authentication modules
13669 Linux @dfn{pluggable authentication module} (PAM) services.
13670 @c FIXME: Add xref to PAM services section.
13672 @item @code{setuid-programs} (default: @code{%setuid-programs})
13673 List of string-valued G-expressions denoting setuid programs.
13674 @xref{Setuid Programs}.
13676 @item @code{sudoers-file} (default: @code{%sudoers-specification})
13677 @cindex sudoers file
13678 The contents of the @file{/etc/sudoers} file as a file-like object
13679 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
13681 This file specifies which users can use the @command{sudo} command, what
13682 they are allowed to do, and what privileges they may gain. The default
13683 is that only @code{root} and members of the @code{wheel} group may use
13688 @deffn {Scheme Syntax} this-operating-system
13689 When used in the @emph{lexical scope} of an operating system field definition,
13690 this identifier resolves to the operating system being defined.
13692 The example below shows how to refer to the operating system being defined in
13693 the definition of the @code{label} field:
13696 (use-modules (gnu) (guix))
13700 (label (package-full-name
13701 (operating-system-kernel this-operating-system))))
13704 It is an error to refer to @code{this-operating-system} outside an operating
13711 @section File Systems
13713 The list of file systems to be mounted is specified in the
13714 @code{file-systems} field of the operating system declaration
13715 (@pxref{Using the Configuration System}). Each file system is declared
13716 using the @code{file-system} form, like this:
13720 (mount-point "/home")
13721 (device "/dev/sda3")
13725 As usual, some of the fields are mandatory---those shown in the example
13726 above---while others can be omitted. These are described below.
13728 @deftp {Data Type} file-system
13729 Objects of this type represent file systems to be mounted. They
13730 contain the following members:
13734 This is a string specifying the type of the file system---e.g.,
13737 @item @code{mount-point}
13738 This designates the place where the file system is to be mounted.
13740 @item @code{device}
13741 This names the ``source'' of the file system. It can be one of three
13742 things: a file system label, a file system UUID, or the name of a
13743 @file{/dev} node. Labels and UUIDs offer a way to refer to file
13744 systems without having to hard-code their actual device
13745 name@footnote{Note that, while it is tempting to use
13746 @file{/dev/disk/by-uuid} and similar device names to achieve the same
13747 result, this is not recommended: These special device nodes are created
13748 by the udev daemon and may be unavailable at the time the device is
13751 @findex file-system-label
13752 File system labels are created using the @code{file-system-label}
13753 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
13754 plain strings. Here's an example of a file system referred to by its
13755 label, as shown by the @command{e2label} command:
13759 (mount-point "/home")
13761 (device (file-system-label "my-home")))
13765 UUIDs are converted from their string representation (as shown by the
13766 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
13767 @code{uuid} form expects 16-byte UUIDs as defined in
13768 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
13769 form of UUID used by the ext2 family of file systems and others, but it
13770 is different from ``UUIDs'' found in FAT file systems, for instance.},
13775 (mount-point "/home")
13777 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
13780 When the source of a file system is a mapped device (@pxref{Mapped
13781 Devices}), its @code{device} field @emph{must} refer to the mapped
13782 device name---e.g., @file{"/dev/mapper/root-partition"}.
13783 This is required so that
13784 the system knows that mounting the file system depends on having the
13785 corresponding device mapping established.
13787 @item @code{flags} (default: @code{'()})
13788 This is a list of symbols denoting mount flags. Recognized flags
13789 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
13790 access to special files), @code{no-suid} (ignore setuid and setgid
13791 bits), @code{no-atime} (do not update file access times),
13792 @code{strict-atime} (update file access time), @code{lazy-time} (only
13793 update time on the in-memory version of the file inode), and
13794 @code{no-exec} (disallow program execution).
13795 @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
13796 Manual}, for more information on these flags.
13798 @item @code{options} (default: @code{#f})
13799 This is either @code{#f}, or a string denoting mount options passed to
13800 the file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C
13801 Library Reference Manual}, for details and run @command{man 8 mount} for
13802 options for various file systems. Note that the
13803 @code{file-system-options->alist} and @code{alist->file-system-options}
13804 procedures from @code{(gnu system file-systems)} can be used to convert
13805 file system options given as an association list to the string
13806 representation, and vice-versa.
13808 @item @code{mount?} (default: @code{#t})
13809 This value indicates whether to automatically mount the file system when
13810 the system is brought up. When set to @code{#f}, the file system gets
13811 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
13812 is not automatically mounted.
13814 @item @code{needed-for-boot?} (default: @code{#f})
13815 This Boolean value indicates whether the file system is needed when
13816 booting. If that is true, then the file system is mounted when the
13817 initial RAM disk (initrd) is loaded. This is always the case, for
13818 instance, for the root file system.
13820 @item @code{check?} (default: @code{#t})
13821 This Boolean indicates whether the file system needs to be checked for
13822 errors before being mounted.
13824 @item @code{create-mount-point?} (default: @code{#f})
13825 When true, the mount point is created if it does not exist yet.
13827 @item @code{mount-may-fail?} (default: @code{#f})
13828 When true, this indicates that mounting this file system can fail but
13829 that should not be considered an error. This is useful in unusual
13830 cases; an example of this is @code{efivarfs}, a file system that can
13831 only be mounted on EFI/UEFI systems.
13833 @item @code{dependencies} (default: @code{'()})
13834 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
13835 representing file systems that must be mounted or mapped devices that
13836 must be opened before (and unmounted or closed after) this one.
13838 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
13839 a dependency of @file{/sys/fs/cgroup/cpu} and
13840 @file{/sys/fs/cgroup/memory}.
13842 Another example is a file system that depends on a mapped device, for
13843 example for an encrypted partition (@pxref{Mapped Devices}).
13847 @deffn {Scheme Procedure} file-system-label @var{str}
13848 This procedure returns an opaque file system label from @var{str}, a
13852 (file-system-label "home")
13853 @result{} #<file-system-label "home">
13856 File system labels are used to refer to file systems by label rather
13857 than by device name. See above for examples.
13860 The @code{(gnu system file-systems)} exports the following useful
13863 @defvr {Scheme Variable} %base-file-systems
13864 These are essential file systems that are required on normal systems,
13865 such as @code{%pseudo-terminal-file-system} and @code{%immutable-store} (see
13866 below). Operating system declarations should always contain at least
13870 @defvr {Scheme Variable} %pseudo-terminal-file-system
13871 This is the file system to be mounted as @file{/dev/pts}. It supports
13872 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
13873 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
13874 Manual}). Pseudo-terminals are used by terminal emulators such as
13878 @defvr {Scheme Variable} %shared-memory-file-system
13879 This file system is mounted as @file{/dev/shm} and is used to support
13880 memory sharing across processes (@pxref{Memory-mapped I/O,
13881 @code{shm_open},, libc, The GNU C Library Reference Manual}).
13884 @defvr {Scheme Variable} %immutable-store
13885 This file system performs a read-only ``bind mount'' of
13886 @file{/gnu/store}, making it read-only for all the users including
13887 @code{root}. This prevents against accidental modification by software
13888 running as @code{root} or by system administrators.
13890 The daemon itself is still able to write to the store: it remounts it
13891 read-write in its own ``name space.''
13894 @defvr {Scheme Variable} %binary-format-file-system
13895 The @code{binfmt_misc} file system, which allows handling of arbitrary
13896 executable file types to be delegated to user space. This requires the
13897 @code{binfmt.ko} kernel module to be loaded.
13900 @defvr {Scheme Variable} %fuse-control-file-system
13901 The @code{fusectl} file system, which allows unprivileged users to mount
13902 and unmount user-space FUSE file systems. This requires the
13903 @code{fuse.ko} kernel module to be loaded.
13906 The @code{(gnu system uuid)} module provides tools to deal with file
13907 system ``unique identifiers'' (UUIDs).
13909 @deffn {Scheme Procedure} uuid @var{str} [@var{type}]
13910 Return an opaque UUID (unique identifier) object of the given @var{type}
13911 (a symbol) by parsing @var{str} (a string):
13914 (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")
13915 @result{} #<<uuid> type: dce bv: @dots{}>
13917 (uuid "1234-ABCD" 'fat)
13918 @result{} #<<uuid> type: fat bv: @dots{}>
13921 @var{type} may be one of @code{dce}, @code{iso9660}, @code{fat},
13922 @code{ntfs}, or one of the commonly found synonyms for these.
13924 UUIDs are another way to unambiguously refer to file systems in
13925 operating system configuration. See the examples above.
13929 @node Btrfs file system
13930 @subsection Btrfs file system
13932 The Btrfs has special features, such as subvolumes, that merit being
13933 explained in more details. The following section attempts to cover
13934 basic as well as complex uses of a Btrfs file system with the Guix
13937 In its simplest usage, a Btrfs file system can be described, for
13942 (mount-point "/home")
13944 (device (file-system-label "my-home")))
13947 The example below is more complex, as it makes use of a Btrfs
13948 subvolume, named @code{rootfs}. The parent Btrfs file system is labeled
13949 @code{my-btrfs-pool}, and is located on an encrypted device (hence the
13950 dependency on @code{mapped-devices}):
13954 (device (file-system-label "my-btrfs-pool"))
13957 (options "subvol=rootfs")
13958 (dependencies mapped-devices))
13961 Some bootloaders, for example GRUB, only mount a Btrfs partition at its
13962 top level during the early boot, and rely on their configuration to
13963 refer to the correct subvolume path within that top level. The
13964 bootloaders operating in this way typically produce their configuration
13965 on a running system where the Btrfs partitions are already mounted and
13966 where the subvolume information is readily available. As an example,
13967 @command{grub-mkconfig}, the configuration generator command shipped
13968 with GRUB, reads @file{/proc/self/mountinfo} to determine the top-level
13969 path of a subvolume.
13971 The Guix System produces a bootloader configuration using the operating
13972 system configuration as its sole input; it is therefore necessary to
13973 extract the subvolume name on which @file{/gnu/store} lives (if any)
13974 from that operating system configuration. To better illustrate,
13975 consider a subvolume named 'rootfs' which contains the root file system
13976 data. In such situation, the GRUB bootloader would only see the top
13977 level of the root Btrfs partition, e.g.:
13981 ├── rootfs (subvolume directory)
13982 ├── gnu (normal directory)
13983 ├── store (normal directory)
13987 Thus, the subvolume name must be prepended to the @file{/gnu/store} path
13988 of the kernel, initrd binaries and any other files referred to in the
13989 GRUB configuration that must be found during the early boot.
13991 The next example shows a nested hierarchy of subvolumes and
13996 ├── rootfs (subvolume)
13997 ├── gnu (normal directory)
13998 ├── store (subvolume)
14002 This scenario would work without mounting the 'store' subvolume.
14003 Mounting 'rootfs' is sufficient, since the subvolume name matches its
14004 intended mount point in the file system hierarchy. Alternatively, the
14005 'store' subvolume could be referred to by setting the @code{subvol}
14006 option to either @code{/rootfs/gnu/store} or @code{rootfs/gnu/store}.
14008 Finally, a more contrived example of nested subvolumes:
14012 ├── root-snapshots (subvolume)
14013 ├── root-current (subvolume)
14014 ├── guix-store (subvolume)
14018 Here, the 'guix-store' subvolume doesn't match its intended mount point,
14019 so it is necessary to mount it. The subvolume must be fully specified,
14020 by passing its file name to the @code{subvol} option. To illustrate,
14021 the 'guix-store' subvolume could be mounted on @file{/gnu/store} by using
14022 a file system declaration such as:
14026 (device (file-system-label "btrfs-pool-1"))
14027 (mount-point "/gnu/store")
14029 (options "subvol=root-snapshots/root-current/guix-store,\
14030 compress-force=zstd,space_cache=v2"))
14033 @node Mapped Devices
14034 @section Mapped Devices
14036 @cindex device mapping
14037 @cindex mapped devices
14038 The Linux kernel has a notion of @dfn{device mapping}: a block device,
14039 such as a hard disk partition, can be @dfn{mapped} into another device,
14040 usually in @code{/dev/mapper/},
14041 with additional processing over the data that flows through
14042 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
14043 concept of a ``mapped device'' and that of a file system: both boil down
14044 to @emph{translating} input/output operations made on a file to
14045 operations on its backing store. Thus, the Hurd implements mapped
14046 devices, like file systems, using the generic @dfn{translator} mechanism
14047 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
14048 typical example is encryption device mapping: all writes to the mapped
14049 device are encrypted, and all reads are deciphered, transparently.
14050 Guix extends this notion by considering any device or set of devices that
14051 are @dfn{transformed} in some way to create a new device; for instance,
14052 RAID devices are obtained by @dfn{assembling} several other devices, such
14053 as hard disks or partitions, into a new one that behaves as one partition.
14055 Mapped devices are declared using the @code{mapped-device} form,
14056 defined as follows; for examples, see below.
14058 @deftp {Data Type} mapped-device
14059 Objects of this type represent device mappings that will be made when
14060 the system boots up.
14064 This is either a string specifying the name of the block device to be mapped,
14065 such as @code{"/dev/sda3"}, or a list of such strings when several devices
14066 need to be assembled for creating a new one. In case of LVM this is a
14067 string specifying name of the volume group to be mapped.
14070 This string specifies the name of the resulting mapped device. For
14071 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
14072 specifying @code{"my-partition"} leads to the creation of
14073 the @code{"/dev/mapper/my-partition"} device.
14074 For RAID devices of type @code{raid-device-mapping}, the full device name
14075 such as @code{"/dev/md0"} needs to be given.
14076 LVM logical volumes of type @code{lvm-device-mapping} need to
14077 be specified as @code{"VGNAME-LVNAME"}.
14080 This list of strings specifies names of the resulting mapped devices in case
14081 there are several. The format is identical to @var{target}.
14084 This must be a @code{mapped-device-kind} object, which specifies how
14085 @var{source} is mapped to @var{target}.
14089 @defvr {Scheme Variable} luks-device-mapping
14090 This defines LUKS block device encryption using the @command{cryptsetup}
14091 command from the package with the same name. It relies on the
14092 @code{dm-crypt} Linux kernel module.
14095 @defvr {Scheme Variable} raid-device-mapping
14096 This defines a RAID device, which is assembled using the @code{mdadm}
14097 command from the package with the same name. It requires a Linux kernel
14098 module for the appropriate RAID level to be loaded, such as @code{raid456}
14099 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
14102 @cindex LVM, logical volume manager
14103 @defvr {Scheme Variable} lvm-device-mapping
14104 This defines one or more logical volumes for the Linux
14105 @uref{https://www.sourceware.org/lvm2/, Logical Volume Manager (LVM)}.
14106 The volume group is activated by the @command{vgchange} command from the
14107 @code{lvm2} package.
14110 @cindex disk encryption
14112 The following example specifies a mapping from @file{/dev/sda3} to
14113 @file{/dev/mapper/home} using LUKS---the
14114 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
14115 standard mechanism for disk encryption.
14116 The @file{/dev/mapper/home}
14117 device can then be used as the @code{device} of a @code{file-system}
14118 declaration (@pxref{File Systems}).
14122 (source "/dev/sda3")
14124 (type luks-device-mapping))
14127 Alternatively, to become independent of device numbering, one may obtain
14128 the LUKS UUID (@dfn{unique identifier}) of the source device by a
14132 cryptsetup luksUUID /dev/sda3
14135 and use it as follows:
14139 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
14141 (type luks-device-mapping))
14144 @cindex swap encryption
14145 It is also desirable to encrypt swap space, since swap space may contain
14146 sensitive data. One way to accomplish that is to use a swap file in a
14147 file system on a device mapped via LUKS encryption. In this way, the
14148 swap file is encrypted because the entire device is encrypted.
14149 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
14151 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
14152 may be declared as follows:
14156 (source (list "/dev/sda1" "/dev/sdb1"))
14157 (target "/dev/md0")
14158 (type raid-device-mapping))
14161 The @file{/dev/md0} device can then be used as the @code{device} of a
14162 @code{file-system} declaration (@pxref{File Systems}).
14163 Note that the RAID level need not be given; it is chosen during the
14164 initial creation and formatting of the RAID device and is determined
14165 automatically later.
14167 LVM logical volumes ``alpha'' and ``beta'' from volume group ``vg0'' can
14168 be declared as follows:
14173 (targets (list "vg0-alpha" "vg0-beta"))
14174 (type lvm-device-mapping))
14177 Devices @file{/dev/mapper/vg0-alpha} and @file{/dev/mapper/vg0-beta} can
14178 then be used as the @code{device} of a @code{file-system} declaration
14179 (@pxref{File Systems}).
14181 @node User Accounts
14182 @section User Accounts
14186 @cindex user accounts
14187 User accounts and groups are entirely managed through the
14188 @code{operating-system} declaration. They are specified with the
14189 @code{user-account} and @code{user-group} forms:
14195 (supplementary-groups '("wheel" ;allow use of sudo, etc.
14196 "audio" ;sound card
14197 "video" ;video devices such as webcams
14198 "cdrom")) ;the good ol' CD-ROM
14199 (comment "Bob's sister"))
14202 Here's a user account that uses a different shell and a custom home
14203 directory (the default would be @file{"/home/bob"}):
14209 (comment "Alice's bro")
14210 (shell (file-append zsh "/bin/zsh"))
14211 (home-directory "/home/robert"))
14214 When booting or upon completion of @command{guix system reconfigure},
14215 the system ensures that only the user accounts and groups specified in
14216 the @code{operating-system} declaration exist, and with the specified
14217 properties. Thus, account or group creations or modifications made by
14218 directly invoking commands such as @command{useradd} are lost upon
14219 reconfiguration or reboot. This ensures that the system remains exactly
14222 @deftp {Data Type} user-account
14223 Objects of this type represent user accounts. The following members may
14228 The name of the user account.
14232 This is the name (a string) or identifier (a number) of the user group
14233 this account belongs to.
14235 @item @code{supplementary-groups} (default: @code{'()})
14236 Optionally, this can be defined as a list of group names that this
14237 account belongs to.
14239 @item @code{uid} (default: @code{#f})
14240 This is the user ID for this account (a number), or @code{#f}. In the
14241 latter case, a number is automatically chosen by the system when the
14242 account is created.
14244 @item @code{comment} (default: @code{""})
14245 A comment about the account, such as the account owner's full name.
14247 @item @code{home-directory}
14248 This is the name of the home directory for the account.
14250 @item @code{create-home-directory?} (default: @code{#t})
14251 Indicates whether the home directory of this account should be created
14252 if it does not exist yet.
14254 @item @code{shell} (default: Bash)
14255 This is a G-expression denoting the file name of a program to be used as
14256 the shell (@pxref{G-Expressions}). For example, you would refer to the
14257 Bash executable like this:
14260 (file-append bash "/bin/bash")
14264 ... and to the Zsh executable like that:
14267 (file-append zsh "/bin/zsh")
14270 @item @code{system?} (default: @code{#f})
14271 This Boolean value indicates whether the account is a ``system''
14272 account. System accounts are sometimes treated specially; for instance,
14273 graphical login managers do not list them.
14275 @anchor{user-account-password}
14276 @cindex password, for user accounts
14277 @item @code{password} (default: @code{#f})
14278 You would normally leave this field to @code{#f}, initialize user
14279 passwords as @code{root} with the @command{passwd} command, and then let
14280 users change it with @command{passwd}. Passwords set with
14281 @command{passwd} are of course preserved across reboot and
14284 If you @emph{do} want to set an initial password for an account, then
14285 this field must contain the encrypted password, as a string. You can use the
14286 @code{crypt} procedure for this purpose:
14293 ;; Specify a SHA-512-hashed initial password.
14294 (password (crypt "InitialPassword!" "$6$abc")))
14298 The hash of this initial password will be available in a file in
14299 @file{/gnu/store}, readable by all the users, so this method must be used with
14303 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
14304 more information on password encryption, and @ref{Encryption,,, guile, GNU
14305 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
14311 User group declarations are even simpler:
14314 (user-group (name "students"))
14317 @deftp {Data Type} user-group
14318 This type is for, well, user groups. There are just a few fields:
14322 The name of the group.
14324 @item @code{id} (default: @code{#f})
14325 The group identifier (a number). If @code{#f}, a new number is
14326 automatically allocated when the group is created.
14328 @item @code{system?} (default: @code{#f})
14329 This Boolean value indicates whether the group is a ``system'' group.
14330 System groups have low numerical IDs.
14332 @item @code{password} (default: @code{#f})
14333 What, user groups can have a password? Well, apparently yes. Unless
14334 @code{#f}, this field specifies the password of the group.
14339 For convenience, a variable lists all the basic user groups one may
14342 @defvr {Scheme Variable} %base-groups
14343 This is the list of basic user groups that users and/or packages expect
14344 to be present on the system. This includes groups such as ``root'',
14345 ``wheel'', and ``users'', as well as groups used to control access to
14346 specific devices such as ``audio'', ``disk'', and ``cdrom''.
14349 @defvr {Scheme Variable} %base-user-accounts
14350 This is the list of basic system accounts that programs may expect to
14351 find on a GNU/Linux system, such as the ``nobody'' account.
14353 Note that the ``root'' account is not included here. It is a
14354 special-case and is automatically added whether or not it is specified.
14357 @node Keyboard Layout
14358 @section Keyboard Layout
14360 @cindex keyboard layout
14362 To specify what each key of your keyboard does, you need to tell the operating
14363 system what @dfn{keyboard layout} you want to use. The default, when nothing
14364 is specified, is the US English QWERTY layout for 105-key PC keyboards.
14365 However, German speakers will usually prefer the German QWERTZ layout, French
14366 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
14367 or bépo, and they might even want to further customize the effect of some of
14368 the keys. This section explains how to get that done.
14370 @cindex keyboard layout, definition
14371 There are three components that will want to know about your keyboard layout:
14375 The @emph{bootloader} may want to know what keyboard layout you want to use
14376 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
14377 you want, for instance, to make sure that you can type the passphrase of your
14378 encrypted root partition using the right layout.
14381 The @emph{operating system kernel}, Linux, will need that so that the console
14382 is properly configured (@pxref{operating-system Reference,
14383 @code{keyboard-layout}}).
14386 The @emph{graphical display server}, usually Xorg, also has its own idea of
14387 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
14390 Guix allows you to configure all three separately but, fortunately, it allows
14391 you to share the same keyboard layout for all three components.
14393 @cindex XKB, keyboard layouts
14394 Keyboard layouts are represented by records created by the
14395 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
14396 the X Keyboard extension (XKB), each layout has four attributes: a name (often
14397 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
14398 optional variant name, an optional keyboard model name, and a possibly empty
14399 list of additional options. In most cases the layout name is all you care
14402 @deffn {Scheme Procedure} keyboard-layout @var{name} [@var{variant}] @
14403 [#:model] [#:options '()]
14404 Return a new keyboard layout with the given @var{name} and @var{variant}.
14406 @var{name} must be a string such as @code{"fr"}; @var{variant} must be a
14407 string such as @code{"bepo"} or @code{"nodeadkeys"}. See the
14408 @code{xkeyboard-config} package for valid options.
14411 Here are a few examples:
14414 ;; The German QWERTZ layout. Here we assume a standard
14415 ;; "pc105" keyboard model.
14416 (keyboard-layout "de")
14418 ;; The bépo variant of the French layout.
14419 (keyboard-layout "fr" "bepo")
14421 ;; The Catalan layout.
14422 (keyboard-layout "es" "cat")
14424 ;; Arabic layout with "Alt-Shift" to switch to US layout.
14425 (keyboard-layout "ar,us" #:options '("grp:alt_shift_toggle"))
14427 ;; The Latin American Spanish layout. In addition, the
14428 ;; "Caps Lock" key is used as an additional "Ctrl" key,
14429 ;; and the "Menu" key is used as a "Compose" key to enter
14430 ;; accented letters.
14431 (keyboard-layout "latam"
14432 #:options '("ctrl:nocaps" "compose:menu"))
14434 ;; The Russian layout for a ThinkPad keyboard.
14435 (keyboard-layout "ru" #:model "thinkpad")
14437 ;; The "US international" layout, which is the US layout plus
14438 ;; dead keys to enter accented characters. This is for an
14439 ;; Apple MacBook keyboard.
14440 (keyboard-layout "us" "intl" #:model "macbook78")
14443 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
14444 for a complete list of supported layouts, variants, and models.
14446 @cindex keyboard layout, configuration
14447 Let's say you want your system to use the Turkish keyboard layout throughout
14448 your system---bootloader, console, and Xorg. Here's what your system
14449 configuration would look like:
14451 @findex set-xorg-configuration
14453 ;; Using the Turkish layout for the bootloader, the console,
14458 (keyboard-layout (keyboard-layout "tr")) ;for the console
14459 (bootloader (bootloader-configuration
14460 (bootloader grub-efi-bootloader)
14461 (target "/boot/efi")
14462 (keyboard-layout keyboard-layout))) ;for GRUB
14463 (services (cons (set-xorg-configuration
14464 (xorg-configuration ;for Xorg
14465 (keyboard-layout keyboard-layout)))
14466 %desktop-services)))
14469 In the example above, for GRUB and for Xorg, we just refer to the
14470 @code{keyboard-layout} field defined above, but we could just as well refer to
14471 a different layout. The @code{set-xorg-configuration} procedure communicates
14472 the desired Xorg configuration to the graphical log-in manager, by default
14475 We've discussed how to specify the @emph{default} keyboard layout of your
14476 system when it starts, but you can also adjust it at run time:
14480 If you're using GNOME, its settings panel has a ``Region & Language'' entry
14481 where you can select one or more keyboard layouts.
14484 Under Xorg, the @command{setxkbmap} command (from the same-named package)
14485 allows you to change the current layout. For example, this is how you would
14486 change the layout to US Dvorak:
14489 setxkbmap us dvorak
14493 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
14494 console. However, note that @code{loadkeys} does @emph{not} use the XKB
14495 keyboard layout categorization described above. The command below loads the
14496 French bépo layout:
14507 A @dfn{locale} defines cultural conventions for a particular language
14508 and region of the world (@pxref{Locales,,, libc, The GNU C Library
14509 Reference Manual}). Each locale has a name that typically has the form
14510 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
14511 @code{fr_LU.utf8} designates the locale for the French language, with
14512 cultural conventions from Luxembourg, and using the UTF-8 encoding.
14514 @cindex locale definition
14515 Usually, you will want to specify the default locale for the machine
14516 using the @code{locale} field of the @code{operating-system} declaration
14517 (@pxref{operating-system Reference, @code{locale}}).
14519 The selected locale is automatically added to the @dfn{locale
14520 definitions} known to the system if needed, with its codeset inferred
14521 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
14522 @code{UTF-8} codeset. Additional locale definitions can be specified in
14523 the @code{locale-definitions} slot of @code{operating-system}---this is
14524 useful, for instance, if the codeset could not be inferred from the
14525 locale name. The default set of locale definitions includes some widely
14526 used locales, but not all the available locales, in order to save space.
14528 For instance, to add the North Frisian locale for Germany, the value of
14532 (cons (locale-definition
14533 (name "fy_DE.utf8") (source "fy_DE"))
14534 %default-locale-definitions)
14537 Likewise, to save space, one might want @code{locale-definitions} to
14538 list only the locales that are actually used, as in:
14541 (list (locale-definition
14542 (name "ja_JP.eucjp") (source "ja_JP")
14543 (charset "EUC-JP")))
14547 The compiled locale definitions are available at
14548 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
14549 version, which is the default location where the GNU@tie{}libc provided
14550 by Guix looks for locale data. This can be overridden using the
14551 @env{LOCPATH} environment variable (@pxref{locales-and-locpath,
14552 @env{LOCPATH} and locale packages}).
14554 The @code{locale-definition} form is provided by the @code{(gnu system
14555 locale)} module. Details are given below.
14557 @deftp {Data Type} locale-definition
14558 This is the data type of a locale definition.
14563 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
14564 Reference Manual}, for more information on locale names.
14566 @item @code{source}
14567 The name of the source for that locale. This is typically the
14568 @code{@var{language}_@var{territory}} part of the locale name.
14570 @item @code{charset} (default: @code{"UTF-8"})
14571 The ``character set'' or ``code set'' for that locale,
14572 @uref{https://www.iana.org/assignments/character-sets, as defined by
14578 @defvr {Scheme Variable} %default-locale-definitions
14579 A list of commonly used UTF-8 locales, used as the default
14580 value of the @code{locale-definitions} field of @code{operating-system}
14583 @cindex locale name
14584 @cindex normalized codeset in locale names
14585 These locale definitions use the @dfn{normalized codeset} for the part
14586 that follows the dot in the name (@pxref{Using gettextized software,
14587 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
14588 instance it has @code{uk_UA.utf8} but @emph{not}, say,
14589 @code{uk_UA.UTF-8}.
14592 @subsection Locale Data Compatibility Considerations
14594 @cindex incompatibility, of locale data
14595 @code{operating-system} declarations provide a @code{locale-libcs} field
14596 to specify the GNU@tie{}libc packages that are used to compile locale
14597 declarations (@pxref{operating-system Reference}). ``Why would I
14598 care?'', you may ask. Well, it turns out that the binary format of
14599 locale data is occasionally incompatible from one libc version to
14602 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
14603 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
14604 For instance, a program linked against libc version 2.21 is unable to
14605 read locale data produced with libc 2.22; worse, that program
14606 @emph{aborts} instead of simply ignoring the incompatible locale
14607 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
14608 the incompatible locale data, which is already an improvement.}.
14609 Similarly, a program linked against libc 2.22 can read most, but not
14610 all, of the locale data from libc 2.21 (specifically, @env{LC_COLLATE}
14611 data is incompatible); thus calls to @code{setlocale} may fail, but
14612 programs will not abort.
14614 The ``problem'' with Guix is that users have a lot of freedom: They can
14615 choose whether and when to upgrade software in their profiles, and might
14616 be using a libc version different from the one the system administrator
14617 used to build the system-wide locale data.
14619 Fortunately, unprivileged users can also install their own locale data
14620 and define @env{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
14621 @env{GUIX_LOCPATH} and locale packages}).
14623 Still, it is best if the system-wide locale data at
14624 @file{/run/current-system/locale} is built for all the libc versions
14625 actually in use on the system, so that all the programs can access
14626 it---this is especially crucial on a multi-user system. To do that, the
14627 administrator can specify several libc packages in the
14628 @code{locale-libcs} field of @code{operating-system}:
14631 (use-package-modules base)
14635 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
14638 This example would lead to a system containing locale definitions for
14639 both libc 2.21 and the current version of libc in
14640 @file{/run/current-system/locale}.
14646 @cindex system services
14647 An important part of preparing an @code{operating-system} declaration is
14648 listing @dfn{system services} and their configuration (@pxref{Using the
14649 Configuration System}). System services are typically daemons launched
14650 when the system boots, or other actions needed at that time---e.g.,
14651 configuring network access.
14653 Guix has a broad definition of ``service'' (@pxref{Service
14654 Composition}), but many services are managed by the GNU@tie{}Shepherd
14655 (@pxref{Shepherd Services}). On a running system, the @command{herd}
14656 command allows you to list the available services, show their status,
14657 start and stop them, or do other specific operations (@pxref{Jump
14658 Start,,, shepherd, The GNU Shepherd Manual}). For example:
14664 The above command, run as @code{root}, lists the currently defined
14665 services. The @command{herd doc} command shows a synopsis of the given
14666 service and its associated actions:
14670 Run libc's name service cache daemon (nscd).
14672 # herd doc nscd action invalidate
14673 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
14676 The @command{start}, @command{stop}, and @command{restart} sub-commands
14677 have the effect you would expect. For instance, the commands below stop
14678 the nscd service and restart the Xorg display server:
14682 Service nscd has been stopped.
14683 # herd restart xorg-server
14684 Service xorg-server has been stopped.
14685 Service xorg-server has been started.
14688 The following sections document the available services, starting with
14689 the core services, that may be used in an @code{operating-system}
14693 * Base Services:: Essential system services.
14694 * Scheduled Job Execution:: The mcron service.
14695 * Log Rotation:: The rottlog service.
14696 * Networking Services:: Network setup, SSH daemon, etc.
14697 * Unattended Upgrades:: Automated system upgrades.
14698 * X Window:: Graphical display.
14699 * Printing Services:: Local and remote printer support.
14700 * Desktop Services:: D-Bus and desktop services.
14701 * Sound Services:: ALSA and Pulseaudio services.
14702 * Database Services:: SQL databases, key-value stores, etc.
14703 * Mail Services:: IMAP, POP3, SMTP, and all that.
14704 * Messaging Services:: Messaging services.
14705 * Telephony Services:: Telephony services.
14706 * Monitoring Services:: Monitoring services.
14707 * Kerberos Services:: Kerberos services.
14708 * LDAP Services:: LDAP services.
14709 * Web Services:: Web servers.
14710 * Certificate Services:: TLS certificates via Let's Encrypt.
14711 * DNS Services:: DNS daemons.
14712 * VPN Services:: VPN daemons.
14713 * Network File System:: NFS related services.
14714 * Continuous Integration:: The Cuirass service.
14715 * Power Management Services:: Extending battery life.
14716 * Audio Services:: The MPD.
14717 * Virtualization Services:: Virtualization services.
14718 * Version Control Services:: Providing remote access to Git repositories.
14719 * Game Services:: Game servers.
14720 * PAM Mount Service:: Service to mount volumes when logging in.
14721 * Guix Services:: Services relating specifically to Guix.
14722 * Linux Services:: Services tied to the Linux kernel.
14723 * Hurd Services:: Services specific for a Hurd System.
14724 * Miscellaneous Services:: Other services.
14727 @node Base Services
14728 @subsection Base Services
14730 The @code{(gnu services base)} module provides definitions for the basic
14731 services that one expects from the system. The services exported by
14732 this module are listed below.
14734 @defvr {Scheme Variable} %base-services
14735 This variable contains a list of basic services (@pxref{Service Types
14736 and Services}, for more information on service objects) one would
14737 expect from the system: a login service (mingetty) on each tty, syslogd,
14738 the libc name service cache daemon (nscd), the udev device manager, and
14741 This is the default value of the @code{services} field of
14742 @code{operating-system} declarations. Usually, when customizing a
14743 system, you will want to append services to @code{%base-services}, like
14747 (append (list (service avahi-service-type)
14748 (service openssh-service-type))
14753 @defvr {Scheme Variable} special-files-service-type
14754 This is the service that sets up ``special files'' such as
14755 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
14757 The value associated with @code{special-files-service-type} services
14758 must be a list of tuples where the first element is the ``special file''
14759 and the second element is its target. By default it is:
14761 @cindex @file{/bin/sh}
14762 @cindex @file{sh}, in @file{/bin}
14764 `(("/bin/sh" ,(file-append bash "/bin/sh")))
14767 @cindex @file{/usr/bin/env}
14768 @cindex @file{env}, in @file{/usr/bin}
14769 If you want to add, say, @code{/usr/bin/env} to your system, you can
14773 `(("/bin/sh" ,(file-append bash "/bin/sh"))
14774 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
14777 Since this is part of @code{%base-services}, you can use
14778 @code{modify-services} to customize the set of special files
14779 (@pxref{Service Reference, @code{modify-services}}). But the simple way
14780 to add a special file is @i{via} the @code{extra-special-file} procedure
14784 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
14785 Use @var{target} as the ``special file'' @var{file}.
14787 For example, adding the following lines to the @code{services} field of
14788 your operating system declaration leads to a @file{/usr/bin/env}
14792 (extra-special-file "/usr/bin/env"
14793 (file-append coreutils "/bin/env"))
14797 @deffn {Scheme Procedure} host-name-service @var{name}
14798 Return a service that sets the host name to @var{name}.
14801 @defvr {Scheme Variable} console-font-service-type
14802 Install the given fonts on the specified ttys (fonts are per
14803 virtual console on the kernel Linux). The value of this service is a list of
14804 tty/font pairs. The font can be the name of a font provided by the @code{kbd}
14805 package or any valid argument to @command{setfont}, as in this example:
14808 `(("tty1" . "LatGrkCyr-8x16")
14809 ("tty2" . ,(file-append
14811 "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
14812 ("tty3" . ,(file-append
14814 "/share/consolefonts/ter-132n"))) ; for HDPI
14818 @deffn {Scheme Procedure} login-service @var{config}
14819 Return a service to run login according to @var{config}, a
14820 @code{<login-configuration>} object, which specifies the message of the day,
14821 among other things.
14824 @deftp {Data Type} login-configuration
14825 This is the data type representing the configuration of login.
14830 @cindex message of the day
14831 A file-like object containing the ``message of the day''.
14833 @item @code{allow-empty-passwords?} (default: @code{#t})
14834 Allow empty passwords by default so that first-time users can log in when
14835 the 'root' account has just been created.
14840 @deffn {Scheme Procedure} mingetty-service @var{config}
14841 Return a service to run mingetty according to @var{config}, a
14842 @code{<mingetty-configuration>} object, which specifies the tty to run, among
14846 @deftp {Data Type} mingetty-configuration
14847 This is the data type representing the configuration of Mingetty, which
14848 provides the default implementation of virtual console log-in.
14853 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
14855 @item @code{auto-login} (default: @code{#f})
14856 When true, this field must be a string denoting the user name under
14857 which the system automatically logs in. When it is @code{#f}, a
14858 user name and password must be entered to log in.
14860 @item @code{login-program} (default: @code{#f})
14861 This must be either @code{#f}, in which case the default log-in program
14862 is used (@command{login} from the Shadow tool suite), or a gexp denoting
14863 the name of the log-in program.
14865 @item @code{login-pause?} (default: @code{#f})
14866 When set to @code{#t} in conjunction with @var{auto-login}, the user
14867 will have to press a key before the log-in shell is launched.
14869 @item @code{clear-on-logout?} (default: @code{#t})
14870 When set to @code{#t}, the screen will be cleared after logout.
14872 @item @code{mingetty} (default: @var{mingetty})
14873 The Mingetty package to use.
14878 @deffn {Scheme Procedure} agetty-service @var{config}
14879 Return a service to run agetty according to @var{config}, an
14880 @code{<agetty-configuration>} object, which specifies the tty to run,
14881 among other things.
14884 @deftp {Data Type} agetty-configuration
14885 This is the data type representing the configuration of agetty, which
14886 implements virtual and serial console log-in. See the @code{agetty(8)}
14887 man page for more information.
14892 The name of the console this agetty runs on, as a string---e.g.,
14893 @code{"ttyS0"}. This argument is optional, it will default to
14894 a reasonable default serial port used by the kernel Linux.
14896 For this, if there is a value for an option @code{agetty.tty} in the kernel
14897 command line, agetty will extract the device name of the serial port
14898 from it and use that.
14900 If not and if there is a value for an option @code{console} with a tty in
14901 the Linux command line, agetty will extract the device name of the
14902 serial port from it and use that.
14904 In both cases, agetty will leave the other serial device settings
14905 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
14908 @item @code{baud-rate} (default: @code{#f})
14909 A string containing a comma-separated list of one or more baud rates, in
14912 @item @code{term} (default: @code{#f})
14913 A string containing the value used for the @env{TERM} environment
14916 @item @code{eight-bits?} (default: @code{#f})
14917 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
14920 @item @code{auto-login} (default: @code{#f})
14921 When passed a login name, as a string, the specified user will be logged
14922 in automatically without prompting for their login name or password.
14924 @item @code{no-reset?} (default: @code{#f})
14925 When @code{#t}, don't reset terminal cflags (control modes).
14927 @item @code{host} (default: @code{#f})
14928 This accepts a string containing the ``login_host'', which will be written
14929 into the @file{/var/run/utmpx} file.
14931 @item @code{remote?} (default: @code{#f})
14932 When set to @code{#t} in conjunction with @var{host}, this will add an
14933 @code{-r} fakehost option to the command line of the login program
14934 specified in @var{login-program}.
14936 @item @code{flow-control?} (default: @code{#f})
14937 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
14939 @item @code{no-issue?} (default: @code{#f})
14940 When set to @code{#t}, the contents of the @file{/etc/issue} file will
14941 not be displayed before presenting the login prompt.
14943 @item @code{init-string} (default: @code{#f})
14944 This accepts a string that will be sent to the tty or modem before
14945 sending anything else. It can be used to initialize a modem.
14947 @item @code{no-clear?} (default: @code{#f})
14948 When set to @code{#t}, agetty will not clear the screen before showing
14951 @item @code{login-program} (default: (file-append shadow "/bin/login"))
14952 This must be either a gexp denoting the name of a log-in program, or
14953 unset, in which case the default value is the @command{login} from the
14956 @item @code{local-line} (default: @code{#f})
14957 Control the CLOCAL line flag. This accepts one of three symbols as
14958 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
14959 the default value chosen by agetty is @code{'auto}.
14961 @item @code{extract-baud?} (default: @code{#f})
14962 When set to @code{#t}, instruct agetty to try to extract the baud rate
14963 from the status messages produced by certain types of modems.
14965 @item @code{skip-login?} (default: @code{#f})
14966 When set to @code{#t}, do not prompt the user for a login name. This
14967 can be used with @var{login-program} field to use non-standard login
14970 @item @code{no-newline?} (default: @code{#f})
14971 When set to @code{#t}, do not print a newline before printing the
14972 @file{/etc/issue} file.
14974 @c Is this dangerous only when used with login-program, or always?
14975 @item @code{login-options} (default: @code{#f})
14976 This option accepts a string containing options that are passed to the
14977 login program. When used with the @var{login-program}, be aware that a
14978 malicious user could try to enter a login name containing embedded
14979 options that could be parsed by the login program.
14981 @item @code{login-pause} (default: @code{#f})
14982 When set to @code{#t}, wait for any key before showing the login prompt.
14983 This can be used in conjunction with @var{auto-login} to save memory by
14984 lazily spawning shells.
14986 @item @code{chroot} (default: @code{#f})
14987 Change root to the specified directory. This option accepts a directory
14990 @item @code{hangup?} (default: @code{#f})
14991 Use the Linux system call @code{vhangup} to do a virtual hangup of the
14992 specified terminal.
14994 @item @code{keep-baud?} (default: @code{#f})
14995 When set to @code{#t}, try to keep the existing baud rate. The baud
14996 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
14999 @item @code{timeout} (default: @code{#f})
15000 When set to an integer value, terminate if no user name could be read
15001 within @var{timeout} seconds.
15003 @item @code{detect-case?} (default: @code{#f})
15004 When set to @code{#t}, turn on support for detecting an uppercase-only
15005 terminal. This setting will detect a login name containing only
15006 uppercase letters as indicating an uppercase-only terminal and turn on
15007 some upper-to-lower case conversions. Note that this will not support
15008 Unicode characters.
15010 @item @code{wait-cr?} (default: @code{#f})
15011 When set to @code{#t}, wait for the user or modem to send a
15012 carriage-return or linefeed character before displaying
15013 @file{/etc/issue} or login prompt. This is typically used with the
15014 @var{init-string} option.
15016 @item @code{no-hints?} (default: @code{#f})
15017 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
15020 @item @code{no-hostname?} (default: @code{#f})
15021 By default, the hostname is printed. When this option is set to
15022 @code{#t}, no hostname will be shown at all.
15024 @item @code{long-hostname?} (default: @code{#f})
15025 By default, the hostname is only printed until the first dot. When this
15026 option is set to @code{#t}, the fully qualified hostname by
15027 @code{gethostname} or @code{getaddrinfo} is shown.
15029 @item @code{erase-characters} (default: @code{#f})
15030 This option accepts a string of additional characters that should be
15031 interpreted as backspace when the user types their login name.
15033 @item @code{kill-characters} (default: @code{#f})
15034 This option accepts a string that should be interpreted to mean ``ignore
15035 all previous characters'' (also called a ``kill'' character) when the user
15036 types their login name.
15038 @item @code{chdir} (default: @code{#f})
15039 This option accepts, as a string, a directory path that will be changed
15042 @item @code{delay} (default: @code{#f})
15043 This options accepts, as an integer, the number of seconds to sleep
15044 before opening the tty and displaying the login prompt.
15046 @item @code{nice} (default: @code{#f})
15047 This option accepts, as an integer, the nice value with which to run the
15048 @command{login} program.
15050 @item @code{extra-options} (default: @code{'()})
15051 This option provides an ``escape hatch'' for the user to provide arbitrary
15052 command-line arguments to @command{agetty} as a list of strings.
15057 @deffn {Scheme Procedure} kmscon-service-type @var{config}
15058 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
15059 according to @var{config}, a @code{<kmscon-configuration>} object, which
15060 specifies the tty to run, among other things.
15063 @deftp {Data Type} kmscon-configuration
15064 This is the data type representing the configuration of Kmscon, which
15065 implements virtual console log-in.
15069 @item @code{virtual-terminal}
15070 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
15072 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
15073 A gexp denoting the name of the log-in program. The default log-in program is
15074 @command{login} from the Shadow tool suite.
15076 @item @code{login-arguments} (default: @code{'("-p")})
15077 A list of arguments to pass to @command{login}.
15079 @item @code{auto-login} (default: @code{#f})
15080 When passed a login name, as a string, the specified user will be logged
15081 in automatically without prompting for their login name or password.
15083 @item @code{hardware-acceleration?} (default: #f)
15084 Whether to use hardware acceleration.
15086 @item @code{kmscon} (default: @var{kmscon})
15087 The Kmscon package to use.
15092 @cindex name service cache daemon
15094 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
15095 [#:name-services '()]
15096 Return a service that runs the libc name service cache daemon (nscd) with the
15097 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
15098 Service Switch}, for an example.
15100 For convenience, the Shepherd service for nscd provides the following actions:
15104 @cindex cache invalidation, nscd
15105 @cindex nscd, cache invalidation
15106 This invalidate the given cache. For instance, running:
15109 herd invalidate nscd hosts
15113 invalidates the host name lookup cache of nscd.
15116 Running @command{herd statistics nscd} displays information about nscd usage
15122 @defvr {Scheme Variable} %nscd-default-configuration
15123 This is the default @code{<nscd-configuration>} value (see below) used
15124 by @code{nscd-service}. It uses the caches defined by
15125 @code{%nscd-default-caches}; see below.
15128 @deftp {Data Type} nscd-configuration
15129 This is the data type representing the name service cache daemon (nscd)
15134 @item @code{name-services} (default: @code{'()})
15135 List of packages denoting @dfn{name services} that must be visible to
15136 the nscd---e.g., @code{(list @var{nss-mdns})}.
15138 @item @code{glibc} (default: @var{glibc})
15139 Package object denoting the GNU C Library providing the @command{nscd}
15142 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
15143 Name of the nscd log file. This is where debugging output goes when
15144 @code{debug-level} is strictly positive.
15146 @item @code{debug-level} (default: @code{0})
15147 Integer denoting the debugging levels. Higher numbers mean that more
15148 debugging output is logged.
15150 @item @code{caches} (default: @code{%nscd-default-caches})
15151 List of @code{<nscd-cache>} objects denoting things to be cached; see
15157 @deftp {Data Type} nscd-cache
15158 Data type representing a cache database of nscd and its parameters.
15162 @item @code{database}
15163 This is a symbol representing the name of the database to be cached.
15164 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
15165 @code{services}, which designate the corresponding NSS database
15166 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
15168 @item @code{positive-time-to-live}
15169 @itemx @code{negative-time-to-live} (default: @code{20})
15170 A number representing the number of seconds during which a positive or
15171 negative lookup result remains in cache.
15173 @item @code{check-files?} (default: @code{#t})
15174 Whether to check for updates of the files corresponding to
15177 For instance, when @var{database} is @code{hosts}, setting this flag
15178 instructs nscd to check for updates in @file{/etc/hosts} and to take
15181 @item @code{persistent?} (default: @code{#t})
15182 Whether the cache should be stored persistently on disk.
15184 @item @code{shared?} (default: @code{#t})
15185 Whether the cache should be shared among users.
15187 @item @code{max-database-size} (default: 32@tie{}MiB)
15188 Maximum size in bytes of the database cache.
15190 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
15191 @c settings, so leave them out.
15196 @defvr {Scheme Variable} %nscd-default-caches
15197 List of @code{<nscd-cache>} objects used by default by
15198 @code{nscd-configuration} (see above).
15200 It enables persistent and aggressive caching of service and host name
15201 lookups. The latter provides better host name lookup performance,
15202 resilience in the face of unreliable name servers, and also better
15203 privacy---often the result of host name lookups is in local cache, so
15204 external name servers do not even need to be queried.
15207 @anchor{syslog-configuration-type}
15210 @deftp {Data Type} syslog-configuration
15211 This data type represents the configuration of the syslog daemon.
15214 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
15215 The syslog daemon to use.
15217 @item @code{config-file} (default: @code{%default-syslog.conf})
15218 The syslog configuration file to use.
15223 @anchor{syslog-service}
15225 @deffn {Scheme Procedure} syslog-service @var{config}
15226 Return a service that runs a syslog daemon according to @var{config}.
15228 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
15229 information on the configuration file syntax.
15232 @defvr {Scheme Variable} guix-service-type
15233 This is the type of the service that runs the build daemon,
15234 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
15235 @code{guix-configuration} record as described below.
15238 @anchor{guix-configuration-type}
15239 @deftp {Data Type} guix-configuration
15240 This data type represents the configuration of the Guix build daemon.
15241 @xref{Invoking guix-daemon}, for more information.
15244 @item @code{guix} (default: @var{guix})
15245 The Guix package to use.
15247 @item @code{build-group} (default: @code{"guixbuild"})
15248 Name of the group for build user accounts.
15250 @item @code{build-accounts} (default: @code{10})
15251 Number of build user accounts to create.
15253 @item @code{authorize-key?} (default: @code{#t})
15254 @cindex substitutes, authorization thereof
15255 Whether to authorize the substitute keys listed in
15256 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
15257 (@pxref{Substitutes}).
15259 When @code{authorize-key?} is true, @file{/etc/guix/acl} cannot be
15260 changed by invoking @command{guix archive --authorize}. You must
15261 instead adjust @code{guix-configuration} as you wish and reconfigure the
15262 system. This ensures that your operating system configuration file is
15266 When booting or reconfiguring to a system where @code{authorize-key?}
15267 is true, the existing @file{/etc/guix/acl} file is backed up as
15268 @file{/etc/guix/acl.bak} if it was determined to be a manually modified
15269 file. This is to facilitate migration from earlier versions, which
15270 allowed for in-place modifications to @file{/etc/guix/acl}.
15273 @vindex %default-authorized-guix-keys
15274 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
15275 The list of authorized key files for archive imports, as a list of
15276 string-valued gexps (@pxref{Invoking guix archive}). By default, it
15277 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
15278 See @code{substitute-urls} below for an example on how to change it.
15280 @item @code{use-substitutes?} (default: @code{#t})
15281 Whether to use substitutes.
15283 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
15284 The list of URLs where to look for substitutes by default.
15286 Suppose you would like to fetch substitutes from @code{guix.example.org}
15287 in addition to @code{@value{SUBSTITUTE-SERVER}}. You will need to do
15288 two things: (1) add @code{guix.example.org} to @code{substitute-urls},
15289 and (2) authorize its signing key, having done appropriate checks
15290 (@pxref{Substitute Server Authorization}). The configuration below does
15294 (guix-configuration
15296 (append (list "https://guix.example.org")
15297 %default-substitute-urls))
15299 (append (list (local-file "./guix.example.org-key.pub"))
15300 %default-authorized-guix-keys)))
15303 This example assumes that the file @file{./guix.example.org-key.pub}
15304 contains the public key that @code{guix.example.org} uses to sign
15307 @item @code{max-silent-time} (default: @code{0})
15308 @itemx @code{timeout} (default: @code{0})
15309 The number of seconds of silence and the number of seconds of activity,
15310 respectively, after which a build process times out. A value of zero
15311 disables the timeout.
15313 @item @code{log-compression} (default: @code{'bzip2})
15314 The type of compression used for build logs---one of @code{gzip},
15315 @code{bzip2}, or @code{none}.
15317 @item @code{discover?} (default: @code{#f})
15318 Whether to discover substitute servers on the local network using mDNS
15321 @item @code{extra-options} (default: @code{'()})
15322 List of extra command-line options for @command{guix-daemon}.
15324 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
15325 File where @command{guix-daemon}'s standard output and standard error
15328 @cindex HTTP proxy, for @code{guix-daemon}
15329 @cindex proxy, for @code{guix-daemon} HTTP access
15330 @item @code{http-proxy} (default: @code{#f})
15331 The URL of the HTTP and HTTPS proxy used for downloading fixed-output
15332 derivations and substitutes.
15334 It is also possible to change the daemon's proxy at run time through the
15335 @code{set-http-proxy} action, which restarts it:
15338 herd set-http-proxy guix-daemon http://localhost:8118
15341 To clear the proxy settings, run:
15344 herd set-http-proxy guix-daemon
15347 @item @code{tmpdir} (default: @code{#f})
15348 A directory path where the @command{guix-daemon} will perform builds.
15353 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
15354 Run @var{udev}, which populates the @file{/dev} directory dynamically.
15355 udev rules can be provided as a list of files through the @var{rules}
15356 variable. The procedures @code{udev-rule}, @code{udev-rules-service}
15357 and @code{file->udev-rule} from @code{(gnu services base)} simplify the
15358 creation of such rule files.
15360 The @command{herd rules udev} command, as root, returns the name of the
15361 directory containing all the active udev rules.
15364 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
15365 Return a udev-rule file named @var{file-name} containing the rules
15366 defined by the @var{contents} literal.
15368 In the following example, a rule for a USB device is defined to be
15369 stored in the file @file{90-usb-thing.rules}. The rule runs a script
15370 upon detecting a USB device with a given product identifier.
15373 (define %example-udev-rule
15375 "90-usb-thing.rules"
15376 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
15377 "ATTR@{product@}==\"Example\", "
15378 "RUN+=\"/path/to/script\"")))
15382 @deffn {Scheme Procedure} udev-rules-service [@var{name} @var{rules}] @
15383 [#:groups @var{groups}]
15384 Return a service that extends @code{udev-service-type } with @var{rules}
15385 and @code{account-service-type} with @var{groups} as system groups.
15386 This works by creating a singleton service type
15387 @code{@var{name}-udev-rules}, of which the returned service is an
15390 Here we show how it can be used to extend @code{udev-service-type} with the
15391 previously defined rule @code{%example-udev-rule}.
15397 (cons (udev-rules-service 'usb-thing %example-udev-rule)
15398 %desktop-services)))
15402 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
15403 Return a udev file named @var{file-name} containing the rules defined
15404 within @var{file}, a file-like object.
15406 The following example showcases how we can use an existing rule file.
15409 (use-modules (guix download) ;for url-fetch
15410 (guix packages) ;for origin
15413 (define %android-udev-rules
15415 "51-android-udev.rules"
15416 (let ((version "20170910"))
15419 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
15420 "android-udev-rules/" version "/51-android.rules"))
15422 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
15426 Additionally, Guix package definitions can be included in @var{rules} in
15427 order to extend the udev rules with the definitions found under their
15428 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
15429 @var{file->udev-rule} example, we could have used the
15430 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
15431 packages android)} module.
15433 The following example shows how to use the @var{android-udev-rules}
15434 package so that the Android tool @command{adb} can detect devices
15435 without root privileges. It also details how to create the
15436 @code{adbusers} group, which is required for the proper functioning of
15437 the rules defined within the @code{android-udev-rules} package. To
15438 create such a group, we must define it both as part of the
15439 @code{supplementary-groups} of our @code{user-account} declaration, as
15440 well as in the @var{groups} of the @code{udev-rules-service} procedure.
15443 (use-modules (gnu packages android) ;for android-udev-rules
15444 (gnu system shadow) ;for user-group
15449 (users (cons (user-account
15451 (supplementary-groups
15452 '("adbusers" ;for adb
15453 "wheel" "netdev" "audio" "video")))))
15456 (cons (udev-rules-service 'android android-udev-rules
15457 #:groups '("adbusers"))
15458 %desktop-services)))
15461 @defvr {Scheme Variable} urandom-seed-service-type
15462 Save some entropy in @code{%random-seed-file} to seed @file{/dev/urandom}
15463 when rebooting. It also tries to seed @file{/dev/urandom} from
15464 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
15468 @defvr {Scheme Variable} %random-seed-file
15469 This is the name of the file where some random bytes are saved by
15470 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
15471 It defaults to @file{/var/lib/random-seed}.
15476 @defvr {Scheme Variable} gpm-service-type
15477 This is the type of the service that runs GPM, the @dfn{general-purpose
15478 mouse daemon}, which provides mouse support to the Linux console. GPM
15479 allows users to use the mouse in the console, notably to select, copy,
15482 The value for services of this type must be a @code{gpm-configuration}
15483 (see below). This service is not part of @code{%base-services}.
15486 @deftp {Data Type} gpm-configuration
15487 Data type representing the configuration of GPM.
15490 @item @code{options} (default: @code{%default-gpm-options})
15491 Command-line options passed to @command{gpm}. The default set of
15492 options instruct @command{gpm} to listen to mouse events on
15493 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
15496 @item @code{gpm} (default: @code{gpm})
15497 The GPM package to use.
15502 @anchor{guix-publish-service-type}
15503 @deffn {Scheme Variable} guix-publish-service-type
15504 This is the service type for @command{guix publish} (@pxref{Invoking
15505 guix publish}). Its value must be a @code{guix-publish-configuration}
15506 object, as described below.
15508 This assumes that @file{/etc/guix} already contains a signing key pair as
15509 created by @command{guix archive --generate-key} (@pxref{Invoking guix
15510 archive}). If that is not the case, the service will fail to start.
15513 @deftp {Data Type} guix-publish-configuration
15514 Data type representing the configuration of the @code{guix publish}
15518 @item @code{guix} (default: @code{guix})
15519 The Guix package to use.
15521 @item @code{port} (default: @code{80})
15522 The TCP port to listen for connections.
15524 @item @code{host} (default: @code{"localhost"})
15525 The host (and thus, network interface) to listen to. Use
15526 @code{"0.0.0.0"} to listen on all the network interfaces.
15528 @item @code{advertise?} (default: @code{#f})
15529 When true, advertise the service on the local network @i{via} the DNS-SD
15530 protocol, using Avahi.
15532 This allows neighboring Guix devices with discovery on (see
15533 @code{guix-configuration} above) to discover this @command{guix publish}
15534 instance and to automatically download substitutes from it.
15536 @item @code{compression} (default: @code{'(("gzip" 3))})
15537 This is a list of compression method/level tuple used when compressing
15538 substitutes. For example, to compress all substitutes with @emph{both} lzip
15539 at level 7 and gzip at level 9, write:
15542 '(("lzip" 7) ("gzip" 9))
15545 Level 9 achieves the best compression ratio at the expense of increased CPU
15546 usage, whereas level 1 achieves fast compression. @xref{Invoking guix
15547 publish}, for more information on the available compression methods and
15548 the tradeoffs involved.
15550 An empty list disables compression altogether.
15552 @item @code{nar-path} (default: @code{"nar"})
15553 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
15554 publish, @option{--nar-path}}, for details.
15556 @item @code{cache} (default: @code{#f})
15557 When it is @code{#f}, disable caching and instead generate archives on
15558 demand. Otherwise, this should be the name of a directory---e.g.,
15559 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
15560 archives and meta-data ready to be sent. @xref{Invoking guix publish,
15561 @option{--cache}}, for more information on the tradeoffs involved.
15563 @item @code{workers} (default: @code{#f})
15564 When it is an integer, this is the number of worker threads used for
15565 caching; when @code{#f}, the number of processors is used.
15566 @xref{Invoking guix publish, @option{--workers}}, for more information.
15568 @item @code{cache-bypass-threshold} (default: 10 MiB)
15569 When @code{cache} is true, this is the maximum size in bytes of a store
15570 item for which @command{guix publish} may bypass its cache in case of a
15571 cache miss. @xref{Invoking guix publish,
15572 @option{--cache-bypass-threshold}}, for more information.
15574 @item @code{ttl} (default: @code{#f})
15575 When it is an integer, this denotes the @dfn{time-to-live} in seconds
15576 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
15577 for more information.
15581 @anchor{rngd-service}
15582 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
15583 [#:device "/dev/hwrng"]
15584 Return a service that runs the @command{rngd} program from @var{rng-tools}
15585 to add @var{device} to the kernel's entropy pool. The service will fail if
15586 @var{device} does not exist.
15589 @anchor{pam-limits-service}
15590 @cindex session limits
15595 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
15597 Return a service that installs a configuration file for the
15598 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
15599 @code{pam_limits} module}. The procedure optionally takes a list of
15600 @code{pam-limits-entry} values, which can be used to specify
15601 @code{ulimit} limits and nice priority limits to user sessions.
15603 The following limits definition sets two hard and soft limits for all
15604 login sessions of users in the @code{realtime} group:
15607 (pam-limits-service
15609 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
15610 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
15613 The first entry increases the maximum realtime priority for
15614 non-privileged processes; the second entry lifts any restriction of the
15615 maximum address space that can be locked in memory. These settings are
15616 commonly used for real-time audio systems.
15619 @node Scheduled Job Execution
15620 @subsection Scheduled Job Execution
15624 @cindex scheduling jobs
15625 The @code{(gnu services mcron)} module provides an interface to
15626 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
15627 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
15628 Unix @command{cron} daemon; the main difference is that it is
15629 implemented in Guile Scheme, which provides a lot of flexibility when
15630 specifying the scheduling of jobs and their actions.
15632 The example below defines an operating system that runs the
15633 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
15634 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
15635 well as the @command{mkid} command on behalf of an unprivileged user
15636 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
15637 gexps to introduce job definitions that are passed to mcron
15638 (@pxref{G-Expressions}).
15641 (use-modules (guix) (gnu) (gnu services mcron))
15642 (use-package-modules base idutils)
15644 (define updatedb-job
15645 ;; Run 'updatedb' at 3AM every day. Here we write the
15646 ;; job's action as a Scheme procedure.
15647 #~(job '(next-hour '(3))
15649 (execl (string-append #$findutils "/bin/updatedb")
15651 "--prunepaths=/tmp /var/tmp /gnu/store"))))
15653 (define garbage-collector-job
15654 ;; Collect garbage 5 minutes after midnight every day.
15655 ;; The job's action is a shell command.
15656 #~(job "5 0 * * *" ;Vixie cron syntax
15659 (define idutils-job
15660 ;; Update the index database as user "charlie" at 12:15PM
15661 ;; and 19:15PM. This runs from the user's home directory.
15662 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
15663 (string-append #$idutils "/bin/mkid src")
15669 ;; %BASE-SERVICES already includes an instance of
15670 ;; 'mcron-service-type', which we extend with additional
15671 ;; jobs using 'simple-service'.
15672 (services (cons (simple-service 'my-cron-jobs
15674 (list garbage-collector-job
15680 For more complex jobs defined in Scheme where you need control over the top
15681 level, for instance to introduce a @code{use-modules} form, you can move your
15682 code to a separate program using the @code{program-file} procedure of the
15683 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
15687 (define %battery-alert-job
15688 ;; Beep when the battery percentage falls below %MIN-LEVEL.
15690 '(next-minute (range 0 60 1))
15692 "battery-alert.scm"
15693 (with-imported-modules (source-module-closure
15694 '((guix build utils)))
15696 (use-modules (guix build utils)
15699 (ice-9 textual-ports)
15702 (define %min-level 20)
15704 (setenv "LC_ALL" "C") ;ensure English output
15705 (and-let* ((input-pipe (open-pipe*
15707 #$(file-append acpi "/bin/acpi")))
15708 (output (get-string-all input-pipe))
15709 (m (string-match "Discharging, ([0-9]+)%" output))
15710 (level (string->number (match:substring m 1)))
15711 ((< level %min-level)))
15712 (format #t "warning: Battery level is low (~a%)~%" level)
15713 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
15716 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
15717 for more information on mcron job specifications. Below is the
15718 reference of the mcron service.
15720 On a running system, you can use the @code{schedule} action of the service to
15721 visualize the mcron jobs that will be executed next:
15724 # herd schedule mcron
15728 The example above lists the next five tasks that will be executed, but you can
15729 also specify the number of tasks to display:
15732 # herd schedule mcron 10
15735 @defvr {Scheme Variable} mcron-service-type
15736 This is the type of the @code{mcron} service, whose value is an
15737 @code{mcron-configuration} object.
15739 This service type can be the target of a service extension that provides
15740 it additional job specifications (@pxref{Service Composition}). In
15741 other words, it is possible to define services that provide additional
15745 @deftp {Data Type} mcron-configuration
15746 Data type representing the configuration of mcron.
15749 @item @code{mcron} (default: @var{mcron})
15750 The mcron package to use.
15753 This is a list of gexps (@pxref{G-Expressions}), where each gexp
15754 corresponds to an mcron job specification (@pxref{Syntax, mcron job
15755 specifications,, mcron, GNU@tie{}mcron}).
15761 @subsection Log Rotation
15764 @cindex log rotation
15766 Log files such as those found in @file{/var/log} tend to grow endlessly,
15767 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
15768 their contents in separate files, possibly compressed. The @code{(gnu
15769 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
15770 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
15772 This service is part of @code{%base-services}, and thus enabled by
15773 default, with the default settings, for commonly encountered log files.
15774 The example below shows how to extend it with an additional
15775 @dfn{rotation}, should you need to do that (usually, services that
15776 produce log files already take care of that):
15779 (use-modules (guix) (gnu))
15780 (use-service-modules admin)
15782 (define my-log-files
15783 ;; Log files that I want to rotate.
15784 '("/var/log/something.log" "/var/log/another.log"))
15788 (services (cons (simple-service 'rotate-my-stuff
15789 rottlog-service-type
15790 (list (log-rotation
15792 (files my-log-files))))
15796 @defvr {Scheme Variable} rottlog-service-type
15797 This is the type of the Rottlog service, whose value is a
15798 @code{rottlog-configuration} object.
15800 Other services can extend this one with new @code{log-rotation} objects
15801 (see below), thereby augmenting the set of files to be rotated.
15803 This service type can define mcron jobs (@pxref{Scheduled Job
15804 Execution}) to run the rottlog service.
15807 @deftp {Data Type} rottlog-configuration
15808 Data type representing the configuration of rottlog.
15811 @item @code{rottlog} (default: @code{rottlog})
15812 The Rottlog package to use.
15814 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
15815 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
15816 rottlog, GNU Rot[t]log Manual}).
15818 @item @code{rotations} (default: @code{%default-rotations})
15819 A list of @code{log-rotation} objects as defined below.
15822 This is a list of gexps where each gexp corresponds to an mcron job
15823 specification (@pxref{Scheduled Job Execution}).
15827 @deftp {Data Type} log-rotation
15828 Data type representing the rotation of a group of log files.
15830 Taking an example from the Rottlog manual (@pxref{Period Related File
15831 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
15837 (files '("/var/log/apache/*"))
15838 (options '("storedir apache-archives"
15844 The list of fields is as follows:
15847 @item @code{frequency} (default: @code{'weekly})
15848 The log rotation frequency, a symbol.
15851 The list of files or file glob patterns to rotate.
15853 @item @code{options} (default: @code{'()})
15854 The list of rottlog options for this rotation (@pxref{Configuration
15855 parameters,,, rottlog, GNU Rot[t]lg Manual}).
15857 @item @code{post-rotate} (default: @code{#f})
15858 Either @code{#f} or a gexp to execute once the rotation has completed.
15862 @defvr {Scheme Variable} %default-rotations
15863 Specifies weekly rotation of @code{%rotated-files} and of
15864 @file{/var/log/guix-daemon.log}.
15867 @defvr {Scheme Variable} %rotated-files
15868 The list of syslog-controlled files to be rotated. By default it is:
15869 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
15870 "/var/log/maillog")}.
15873 @node Networking Services
15874 @subsection Networking Services
15876 The @code{(gnu services networking)} module provides services to configure
15877 the network interface.
15879 @cindex DHCP, networking service
15880 @defvr {Scheme Variable} dhcp-client-service-type
15881 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
15882 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
15883 is the DHCP client package to use, @code{isc-dhcp} by default.
15886 @deffn {Scheme Procedure} dhcpd-service-type
15887 This type defines a service that runs a DHCP daemon. To create a
15888 service of this type, you must supply a @code{<dhcpd-configuration>}.
15892 (service dhcpd-service-type
15893 (dhcpd-configuration
15894 (config-file (local-file "my-dhcpd.conf"))
15895 (interfaces '("enp0s25"))))
15899 @deftp {Data Type} dhcpd-configuration
15901 @item @code{package} (default: @code{isc-dhcp})
15902 The package that provides the DHCP daemon. This package is expected to
15903 provide the daemon at @file{sbin/dhcpd} relative to its output
15904 directory. The default package is the
15905 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
15906 @item @code{config-file} (default: @code{#f})
15907 The configuration file to use. This is required. It will be passed to
15908 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
15909 object (@pxref{G-Expressions, file-like objects}). See @code{man
15910 dhcpd.conf} for details on the configuration file syntax.
15911 @item @code{version} (default: @code{"4"})
15912 The DHCP version to use. The ISC DHCP server supports the values ``4'',
15913 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
15914 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
15916 @item @code{run-directory} (default: @code{"/run/dhcpd"})
15917 The run directory to use. At service activation time, this directory
15918 will be created if it does not exist.
15919 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
15920 The PID file to use. This corresponds to the @code{-pf} option of
15921 @code{dhcpd}. See @code{man dhcpd} for details.
15922 @item @code{interfaces} (default: @code{'()})
15923 The names of the network interfaces on which dhcpd should listen for
15924 broadcasts. If this list is not empty, then its elements (which must be
15925 strings) will be appended to the @code{dhcpd} invocation when starting
15926 the daemon. It may not be necessary to explicitly specify any
15927 interfaces here; see @code{man dhcpd} for details.
15931 @defvr {Scheme Variable} static-networking-service-type
15932 This is the type for statically-configured network interfaces.
15933 @c TODO Document <static-networking> data structures.
15936 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
15937 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
15938 [#:requirement @code{'(udev)}]
15939 Return a service that starts @var{interface} with address @var{ip}. If
15940 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
15941 it must be a string specifying the default network gateway. @var{requirement}
15942 can be used to declare a dependency on another service before configuring the
15945 This procedure can be called several times, one for each network
15946 interface of interest. Behind the scenes what it does is extend
15947 @code{static-networking-service-type} with additional network interfaces
15953 (static-networking-service "eno1" "192.168.1.82"
15954 #:gateway "192.168.1.2"
15955 #:name-servers '("192.168.1.2"))
15962 @cindex network management
15963 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
15964 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
15965 management daemon that aims to simplify wired and wireless networking.
15967 This service adds the @var{wicd} package to the global profile, providing
15968 several commands to interact with the daemon and configure networking:
15969 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
15970 and @command{wicd-curses} user interfaces.
15973 @cindex ModemManager
15975 @defvr {Scheme Variable} modem-manager-service-type
15976 This is the service type for the
15977 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
15978 service. The value for this service type is a
15979 @code{modem-manager-configuration} record.
15981 This service is part of @code{%desktop-services} (@pxref{Desktop
15985 @deftp {Data Type} modem-manager-configuration
15986 Data type representing the configuration of ModemManager.
15989 @item @code{modem-manager} (default: @code{modem-manager})
15990 The ModemManager package to use.
15995 @cindex USB_ModeSwitch
15996 @cindex Modeswitching
15998 @defvr {Scheme Variable} usb-modeswitch-service-type
15999 This is the service type for the
16000 @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch}
16001 service. The value for this service type is
16002 a @code{usb-modeswitch-configuration} record.
16004 When plugged in, some USB modems (and other USB devices) initially present
16005 themselves as a read-only storage medium and not as a modem. They need to be
16006 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
16007 installs udev rules to automatically modeswitch these devices when they are
16010 This service is part of @code{%desktop-services} (@pxref{Desktop
16014 @deftp {Data Type} usb-modeswitch-configuration
16015 Data type representing the configuration of USB_ModeSwitch.
16018 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
16019 The USB_ModeSwitch package providing the binaries for modeswitching.
16021 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
16022 The package providing the device data and udev rules file used by
16025 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
16026 Which config file to use for the USB_ModeSwitch dispatcher. By default the
16027 config file shipped with USB_ModeSwitch is used which disables logging to
16028 @file{/var/log} among other default settings. If set to @code{#f}, no config
16034 @cindex NetworkManager
16036 @defvr {Scheme Variable} network-manager-service-type
16037 This is the service type for the
16038 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
16039 service. The value for this service type is a
16040 @code{network-manager-configuration} record.
16042 This service is part of @code{%desktop-services} (@pxref{Desktop
16046 @deftp {Data Type} network-manager-configuration
16047 Data type representing the configuration of NetworkManager.
16050 @item @code{network-manager} (default: @code{network-manager})
16051 The NetworkManager package to use.
16053 @item @code{dns} (default: @code{"default"})
16054 Processing mode for DNS, which affects how NetworkManager uses the
16055 @code{resolv.conf} configuration file.
16059 NetworkManager will update @code{resolv.conf} to reflect the nameservers
16060 provided by currently active connections.
16063 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
16064 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
16065 then update @code{resolv.conf} to point to the local nameserver.
16067 With this setting, you can share your network connection. For example when
16068 you want to share your network connection to another laptop @i{via} an
16069 Ethernet cable, you can open @command{nm-connection-editor} and configure the
16070 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
16071 and reestablish the connection (or reboot).
16073 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
16074 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
16075 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
16076 browser on your host system, or connect to the VM @i{via} SSH
16077 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
16078 host-to-guest connection, run this command once:
16081 nmcli connection add type tun \
16082 connection.interface-name tap0 \
16083 tun.mode tap tun.owner $(id -u) \
16084 ipv4.method shared \
16085 ipv4.addresses 172.28.112.1/24
16088 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
16089 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
16090 @command{qemu-system-...}.
16093 NetworkManager will not modify @code{resolv.conf}.
16096 @item @code{vpn-plugins} (default: @code{'()})
16097 This is the list of available plugins for virtual private networks
16098 (VPNs). An example of this is the @code{network-manager-openvpn}
16099 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
16105 @deffn {Scheme Variable} connman-service-type
16106 This is the service type to run @url{https://01.org/connman,Connman},
16107 a network connection manager.
16109 Its value must be an
16110 @code{connman-configuration} record as in this example:
16113 (service connman-service-type
16114 (connman-configuration
16115 (disable-vpn? #t)))
16118 See below for details about @code{connman-configuration}.
16121 @deftp {Data Type} connman-configuration
16122 Data Type representing the configuration of connman.
16125 @item @code{connman} (default: @var{connman})
16126 The connman package to use.
16128 @item @code{disable-vpn?} (default: @code{#f})
16129 When true, disable connman's vpn plugin.
16133 @cindex WPA Supplicant
16134 @defvr {Scheme Variable} wpa-supplicant-service-type
16135 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
16136 supplicant}, an authentication daemon required to authenticate against
16137 encrypted WiFi or ethernet networks.
16140 @deftp {Data Type} wpa-supplicant-configuration
16141 Data type representing the configuration of WPA Supplicant.
16143 It takes the following parameters:
16146 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
16147 The WPA Supplicant package to use.
16149 @item @code{requirement} (default: @code{'(user-processes loopback syslogd)}
16150 List of services that should be started before WPA Supplicant starts.
16152 @item @code{dbus?} (default: @code{#t})
16153 Whether to listen for requests on D-Bus.
16155 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
16156 Where to store the PID file.
16158 @item @code{interface} (default: @code{#f})
16159 If this is set, it must specify the name of a network interface that
16160 WPA supplicant will control.
16162 @item @code{config-file} (default: @code{#f})
16163 Optional configuration file to use.
16165 @item @code{extra-options} (default: @code{'()})
16166 List of additional command-line arguments to pass to the daemon.
16170 @cindex hostapd service, for Wi-Fi access points
16171 @cindex Wi-Fi access points, hostapd service
16172 @defvr {Scheme Variable} hostapd-service-type
16173 This is the service type to run the @uref{https://w1.fi/hostapd/,
16174 hostapd} daemon to set up WiFi (IEEE 802.11) access points and
16175 authentication servers. Its associated value must be a
16176 @code{hostapd-configuration} as shown below:
16179 ;; Use wlan1 to run the access point for "My Network".
16180 (service hostapd-service-type
16181 (hostapd-configuration
16182 (interface "wlan1")
16183 (ssid "My Network")
16188 @deftp {Data Type} hostapd-configuration
16189 This data type represents the configuration of the hostapd service, with
16190 the following fields:
16193 @item @code{package} (default: @code{hostapd})
16194 The hostapd package to use.
16196 @item @code{interface} (default: @code{"wlan0"})
16197 The network interface to run the WiFi access point.
16200 The SSID (@dfn{service set identifier}), a string that identifies this
16203 @item @code{broadcast-ssid?} (default: @code{#t})
16204 Whether to broadcast this SSID.
16206 @item @code{channel} (default: @code{1})
16207 The WiFi channel to use.
16209 @item @code{driver} (default: @code{"nl80211"})
16210 The driver interface type. @code{"nl80211"} is used with all Linux
16211 mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
16212 RADIUS server that does # not control any wireless/wired driver.
16214 @item @code{extra-settings} (default: @code{""})
16215 Extra settings to append as-is to the hostapd configuration file. See
16216 @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
16217 configuration file reference.
16221 @defvr {Scheme Variable} simulated-wifi-service-type
16222 This is the type of a service to simulate WiFi networking, which can be
16223 useful in virtual machines for testing purposes. The service loads the
16225 @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
16226 @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
16227 network that can be seen on @code{wlan0}, by default.
16229 The service's value is a @code{hostapd-configuration} record.
16233 @defvr {Scheme Variable} iptables-service-type
16234 This is the service type to set up an iptables configuration. iptables is a
16235 packet filtering framework supported by the Linux kernel. This service
16236 supports configuring iptables for both IPv4 and IPv6. A simple example
16237 configuration rejecting all incoming connections except those to the ssh port
16241 (service iptables-service-type
16242 (iptables-configuration
16243 (ipv4-rules (plain-file "iptables.rules" "*filter
16247 -A INPUT -p tcp --dport 22 -j ACCEPT
16248 -A INPUT -j REJECT --reject-with icmp-port-unreachable
16251 (ipv6-rules (plain-file "ip6tables.rules" "*filter
16255 -A INPUT -p tcp --dport 22 -j ACCEPT
16256 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
16262 @deftp {Data Type} iptables-configuration
16263 The data type representing the configuration of iptables.
16266 @item @code{iptables} (default: @code{iptables})
16267 The iptables package that provides @code{iptables-restore} and
16268 @code{ip6tables-restore}.
16269 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
16270 The iptables rules to use. It will be passed to @code{iptables-restore}.
16271 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
16273 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
16274 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
16275 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
16281 @defvr {Scheme Variable} nftables-service-type
16282 This is the service type to set up a nftables configuration. nftables is a
16283 netfilter project that aims to replace the existing iptables, ip6tables,
16284 arptables and ebtables framework. It provides a new packet filtering
16285 framework, a new user-space utility @command{nft}, and a compatibility layer
16286 for iptables. This service comes with a default ruleset
16287 @code{%default-nftables-ruleset} that rejecting all incomming connections
16288 except those to the ssh port 22. To use it, simply write:
16291 (service nftables-service-type)
16295 @deftp {Data Type} nftables-configuration
16296 The data type representing the configuration of nftables.
16299 @item @code{package} (default: @code{nftables})
16300 The nftables package that provides @command{nft}.
16301 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
16302 The nftables ruleset to use. This may be any ``file-like'' object
16303 (@pxref{G-Expressions, file-like objects}).
16307 @cindex NTP (Network Time Protocol), service
16308 @cindex ntpd, service for the Network Time Protocol daemon
16309 @cindex real time clock
16310 @defvr {Scheme Variable} ntp-service-type
16311 This is the type of the service running the @uref{https://www.ntp.org,
16312 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
16313 system clock synchronized with that of the specified NTP servers.
16315 The value of this service is an @code{ntpd-configuration} object, as described
16319 @deftp {Data Type} ntp-configuration
16320 This is the data type for the NTP service configuration.
16323 @item @code{servers} (default: @code{%ntp-servers})
16324 This is the list of servers (@code{<ntp-server>} records) with which
16325 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
16328 @item @code{allow-large-adjustment?} (default: @code{#t})
16329 This determines whether @command{ntpd} is allowed to make an initial
16330 adjustment of more than 1,000 seconds.
16332 @item @code{ntp} (default: @code{ntp})
16333 The NTP package to use.
16337 @defvr {Scheme Variable} %ntp-servers
16338 List of host names used as the default NTP servers. These are servers of the
16339 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
16342 @deftp {Data Type} ntp-server
16343 The data type representing the configuration of a NTP server.
16346 @item @code{type} (default: @code{'server})
16347 The type of the NTP server, given as a symbol. One of @code{'pool},
16348 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
16350 @item @code{address}
16351 The address of the server, as a string.
16353 @item @code{options}
16354 NTPD options to use with that specific server, given as a list of option names
16355 and/or of option names and values tuples. The following example define a server
16356 to use with the options @option{iburst} and @option{prefer}, as well as
16357 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
16362 (address "some.ntp.server.org")
16363 (options `(iburst (version 3) (maxpoll 16) prefer))))
16369 @deffn {Scheme Procedure} openntpd-service-type
16370 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
16371 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
16372 clock synchronized with that of the given servers.
16376 openntpd-service-type
16377 (openntpd-configuration
16378 (listen-on '("127.0.0.1" "::1"))
16379 (sensor '("udcf0 correction 70000"))
16380 (constraint-from '("www.gnu.org"))
16381 (constraints-from '("https://www.google.com/"))))
16386 @defvr {Scheme Variable} %openntpd-servers
16387 This variable is a list of the server addresses defined in
16388 @code{%ntp-servers}.
16391 @deftp {Data Type} openntpd-configuration
16393 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
16394 The openntpd executable to use.
16395 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
16396 A list of local IP addresses or hostnames the ntpd daemon should listen on.
16397 @item @code{query-from} (default: @code{'()})
16398 A list of local IP address the ntpd daemon should use for outgoing queries.
16399 @item @code{sensor} (default: @code{'()})
16400 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
16401 will listen to each sensor that actually exists and ignore non-existent ones.
16402 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
16404 @item @code{server} (default: @code{'()})
16405 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
16406 @item @code{servers} (default: @code{%openntp-servers})
16407 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
16408 @item @code{constraint-from} (default: @code{'()})
16409 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
16410 This time information is not used for precision but acts as an authenticated
16411 constraint, thereby reducing the impact of unauthenticated NTP
16412 man-in-the-middle attacks.
16413 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
16415 @item @code{constraints-from} (default: @code{'()})
16416 As with constraint from, specify a list of URLs, IP addresses or hostnames of
16417 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
16418 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
16423 @deffn {Scheme variable} inetd-service-type
16424 This service runs the @command{inetd} (@pxref{inetd invocation,,,
16425 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
16426 connections on internet sockets, and lazily starts the specified server
16427 program when a connection is made on one of these sockets.
16429 The value of this service is an @code{inetd-configuration} object. The
16430 following example configures the @command{inetd} daemon to provide the
16431 built-in @command{echo} service, as well as an smtp service which
16432 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
16433 gateway @code{hostname}:
16438 (inetd-configuration
16442 (socket-type 'stream)
16449 (socket-type 'stream)
16453 (program (file-append openssh "/bin/ssh"))
16455 '("ssh" "-qT" "-i" "/path/to/ssh_key"
16456 "-W" "smtp-server:25" "user@@hostname")))))))
16459 See below for more details about @code{inetd-configuration}.
16462 @deftp {Data Type} inetd-configuration
16463 Data type representing the configuration of @command{inetd}.
16466 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
16467 The @command{inetd} executable to use.
16469 @item @code{entries} (default: @code{'()})
16470 A list of @command{inetd} service entries. Each entry should be created
16471 by the @code{inetd-entry} constructor.
16475 @deftp {Data Type} inetd-entry
16476 Data type representing an entry in the @command{inetd} configuration.
16477 Each entry corresponds to a socket where @command{inetd} will listen for
16481 @item @code{node} (default: @code{#f})
16482 Optional string, a comma-separated list of local addresses
16483 @command{inetd} should use when listening for this service.
16484 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
16485 description of all options.
16487 A string, the name must correspond to an entry in @code{/etc/services}.
16488 @item @code{socket-type}
16489 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
16491 @item @code{protocol}
16492 A string, must correspond to an entry in @code{/etc/protocols}.
16493 @item @code{wait?} (default: @code{#t})
16494 Whether @command{inetd} should wait for the server to exit before
16495 listening to new service requests.
16497 A string containing the user (and, optionally, group) name of the user
16498 as whom the server should run. The group name can be specified in a
16499 suffix, separated by a colon or period, i.e.@: @code{"user"},
16500 @code{"user:group"} or @code{"user.group"}.
16501 @item @code{program} (default: @code{"internal"})
16502 The server program which will serve the requests, or @code{"internal"}
16503 if @command{inetd} should use a built-in service.
16504 @item @code{arguments} (default: @code{'()})
16505 A list strings or file-like objects, which are the server program's
16506 arguments, starting with the zeroth argument, i.e.@: the name of the
16507 program itself. For @command{inetd}'s internal services, this entry
16508 must be @code{'()} or @code{'("internal")}.
16511 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
16512 detailed discussion of each configuration field.
16516 @defvr {Scheme Variable} tor-service-type
16517 This is the type for a service that runs the @uref{https://torproject.org,
16518 Tor} anonymous networking daemon. The service is configured using a
16519 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
16520 @code{tor} unprivileged user, which is a member of the @code{tor} group.
16524 @deftp {Data Type} tor-configuration
16526 @item @code{tor} (default: @code{tor})
16527 The package that provides the Tor daemon. This package is expected to provide
16528 the daemon at @file{bin/tor} relative to its output directory. The default
16529 package is the @uref{https://www.torproject.org, Tor Project's}
16532 @item @code{config-file} (default: @code{(plain-file "empty" "")})
16533 The configuration file to use. It will be appended to a default configuration
16534 file, and the final configuration file will be passed to @code{tor} via its
16535 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
16536 file-like objects}). See @code{man tor} for details on the configuration file
16539 @item @code{hidden-services} (default: @code{'()})
16540 The list of @code{<hidden-service>} records to use. For any hidden service
16541 you include in this list, appropriate configuration to enable the hidden
16542 service will be automatically added to the default configuration file. You
16543 may conveniently create @code{<hidden-service>} records using the
16544 @code{tor-hidden-service} procedure described below.
16546 @item @code{socks-socket-type} (default: @code{'tcp})
16547 The default socket type that Tor should use for its SOCKS socket. This must
16548 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
16549 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
16550 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
16551 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
16554 If you want to customize the SOCKS socket in more detail, leave
16555 @code{socks-socket-type} at its default value of @code{'tcp} and use
16556 @code{config-file} to override the default by providing your own
16557 @code{SocksPort} option.
16561 @cindex hidden service
16562 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
16563 Define a new Tor @dfn{hidden service} called @var{name} and implementing
16564 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
16567 '((22 "127.0.0.1:22")
16568 (80 "127.0.0.1:8080"))
16571 In this example, port 22 of the hidden service is mapped to local port 22, and
16572 port 80 is mapped to local port 8080.
16574 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
16575 the @file{hostname} file contains the @code{.onion} host name for the hidden
16578 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
16579 project's documentation} for more information.
16582 The @code{(gnu services rsync)} module provides the following services:
16584 You might want an rsync daemon if you have files that you want available
16585 so anyone (or just yourself) can download existing files or upload new
16588 @deffn {Scheme Variable} rsync-service-type
16589 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
16590 The value for this service type is a
16591 @command{rsync-configuration} record as in this example:
16594 (service rsync-service-type)
16597 See below for details about @code{rsync-configuration}.
16600 @deftp {Data Type} rsync-configuration
16601 Data type representing the configuration for @code{rsync-service}.
16604 @item @code{package} (default: @var{rsync})
16605 @code{rsync} package to use.
16607 @item @code{port-number} (default: @code{873})
16608 TCP port on which @command{rsync} listens for incoming connections. If port
16609 is less than @code{1024} @command{rsync} needs to be started as the
16610 @code{root} user and group.
16612 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
16613 Name of the file where @command{rsync} writes its PID.
16615 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
16616 Name of the file where @command{rsync} writes its lock file.
16618 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
16619 Name of the file where @command{rsync} writes its log file.
16621 @item @code{use-chroot?} (default: @var{#t})
16622 Whether to use chroot for @command{rsync} shared directory.
16624 @item @code{share-path} (default: @file{/srv/rsync})
16625 Location of the @command{rsync} shared directory.
16627 @item @code{share-comment} (default: @code{"Rsync share"})
16628 Comment of the @command{rsync} shared directory.
16630 @item @code{read-only?} (default: @var{#f})
16631 Read-write permissions to shared directory.
16633 @item @code{timeout} (default: @code{300})
16634 I/O timeout in seconds.
16636 @item @code{user} (default: @var{"root"})
16637 Owner of the @code{rsync} process.
16639 @item @code{group} (default: @var{"root"})
16640 Group of the @code{rsync} process.
16642 @item @code{uid} (default: @var{"rsyncd"})
16643 User name or user ID that file transfers to and from that module should take
16644 place as when the daemon was run as @code{root}.
16646 @item @code{gid} (default: @var{"rsyncd"})
16647 Group name or group ID that will be used when accessing the module.
16652 The @code{(gnu services syncthing)} module provides the following services:
16655 You might want a syncthing daemon if you have files between two or more
16656 computers and want to sync them in real time, safely protected from
16659 @deffn {Scheme Variable} syncthing-service-type
16660 This is the service type for the @uref{https://syncthing.net/,
16661 syncthing} daemon, The value for this service type is a
16662 @command{syncthing-configuration} record as in this example:
16665 (service syncthing-service-type
16666 (syncthing-configuration (user "alice")))
16669 See below for details about @code{syncthing-configuration}.
16671 @deftp {Data Type} syncthing-configuration
16672 Data type representing the configuration for @code{syncthing-service-type}.
16675 @item @code{syncthing} (default: @var{syncthing})
16676 @code{syncthing} package to use.
16678 @item @code{arguments} (default: @var{'()})
16679 List of command-line arguments passing to @code{syncthing} binary.
16681 @item @code{logflags} (default: @var{0})
16682 Sum of loging flags, see
16683 @uref{https://docs.syncthing.net/users/syncthing.html#cmdoption-logflags, Syncthing documentation logflags}.
16685 @item @code{user} (default: @var{#f})
16686 The user as which the Syncthing service is to be run.
16687 This assumes that the specified user exists.
16689 @item @code{group} (default: @var{"users"})
16690 The group as which the Syncthing service is to be run.
16691 This assumes that the specified group exists.
16693 @item @code{home} (default: @var{#f})
16694 Common configuration and data directory. The default configuration
16695 directory is @file{$HOME} of the specified Syncthing @code{user}.
16701 Furthermore, @code{(gnu services ssh)} provides the following services.
16705 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
16706 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
16707 [#:allow-empty-passwords? #f] [#:root-login? #f] @
16708 [#:syslog-output? #t] [#:x11-forwarding? #t] @
16709 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
16710 [#:public-key-authentication? #t] [#:initialize? #t]
16711 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
16712 @var{host-key} must designate a file containing the host key, and readable
16715 When @var{daemonic?} is true, @command{lshd} will detach from the
16716 controlling terminal and log its output to syslogd, unless one sets
16717 @var{syslog-output?} to false. Obviously, it also makes lsh-service
16718 depend on existence of syslogd service. When @var{pid-file?} is true,
16719 @command{lshd} writes its PID to the file called @var{pid-file}.
16721 When @var{initialize?} is true, automatically create the seed and host key
16722 upon service activation if they do not exist yet. This may take long and
16723 require interaction.
16725 When @var{initialize?} is false, it is up to the user to initialize the
16726 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
16727 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
16728 basics,,, lsh, LSH Manual}).
16730 When @var{interfaces} is empty, lshd listens for connections on all the
16731 network interfaces; otherwise, @var{interfaces} must be a list of host names
16734 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
16735 passwords, and @var{root-login?} specifies whether to accept log-ins as
16738 The other options should be self-descriptive.
16743 @deffn {Scheme Variable} openssh-service-type
16744 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
16745 shell daemon, @command{sshd}. Its value must be an
16746 @code{openssh-configuration} record as in this example:
16749 (service openssh-service-type
16750 (openssh-configuration
16751 (x11-forwarding? #t)
16752 (permit-root-login 'without-password)
16754 `(("alice" ,(local-file "alice.pub"))
16755 ("bob" ,(local-file "bob.pub"))))))
16758 See below for details about @code{openssh-configuration}.
16760 This service can be extended with extra authorized keys, as in this
16764 (service-extension openssh-service-type
16765 (const `(("charlie"
16766 ,(local-file "charlie.pub")))))
16770 @deftp {Data Type} openssh-configuration
16771 This is the configuration record for OpenSSH's @command{sshd}.
16774 @item @code{openssh} (default @var{openssh})
16775 The Openssh package to use.
16777 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
16778 Name of the file where @command{sshd} writes its PID.
16780 @item @code{port-number} (default: @code{22})
16781 TCP port on which @command{sshd} listens for incoming connections.
16783 @item @code{permit-root-login} (default: @code{#f})
16784 This field determines whether and when to allow logins as root. If
16785 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
16786 If it's the symbol @code{'without-password}, then root logins are
16787 permitted but not with password-based authentication.
16789 @item @code{allow-empty-passwords?} (default: @code{#f})
16790 When true, users with empty passwords may log in. When false, they may
16793 @item @code{password-authentication?} (default: @code{#t})
16794 When true, users may log in with their password. When false, they have
16795 other authentication methods.
16797 @item @code{public-key-authentication?} (default: @code{#t})
16798 When true, users may log in using public key authentication. When
16799 false, users have to use other authentication method.
16801 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
16802 This is used only by protocol version 2.
16804 @item @code{x11-forwarding?} (default: @code{#f})
16805 When true, forwarding of X11 graphical client connections is
16806 enabled---in other words, @command{ssh} options @option{-X} and
16807 @option{-Y} will work.
16809 @item @code{allow-agent-forwarding?} (default: @code{#t})
16810 Whether to allow agent forwarding.
16812 @item @code{allow-tcp-forwarding?} (default: @code{#t})
16813 Whether to allow TCP forwarding.
16815 @item @code{gateway-ports?} (default: @code{#f})
16816 Whether to allow gateway ports.
16818 @item @code{challenge-response-authentication?} (default: @code{#f})
16819 Specifies whether challenge response authentication is allowed (e.g.@: via
16822 @item @code{use-pam?} (default: @code{#t})
16823 Enables the Pluggable Authentication Module interface. If set to
16824 @code{#t}, this will enable PAM authentication using
16825 @code{challenge-response-authentication?} and
16826 @code{password-authentication?}, in addition to PAM account and session
16827 module processing for all authentication types.
16829 Because PAM challenge response authentication usually serves an
16830 equivalent role to password authentication, you should disable either
16831 @code{challenge-response-authentication?} or
16832 @code{password-authentication?}.
16834 @item @code{print-last-log?} (default: @code{#t})
16835 Specifies whether @command{sshd} should print the date and time of the
16836 last user login when a user logs in interactively.
16838 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
16839 Configures external subsystems (e.g.@: file transfer daemon).
16841 This is a list of two-element lists, each of which containing the
16842 subsystem name and a command (with optional arguments) to execute upon
16845 The command @command{internal-sftp} implements an in-process SFTP
16846 server. Alternatively, one can specify the @command{sftp-server} command:
16848 (service openssh-service-type
16849 (openssh-configuration
16851 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
16854 @item @code{accepted-environment} (default: @code{'()})
16855 List of strings describing which environment variables may be exported.
16857 Each string gets on its own line. See the @code{AcceptEnv} option in
16858 @code{man sshd_config}.
16860 This example allows ssh-clients to export the @env{COLORTERM} variable.
16861 It is set by terminal emulators, which support colors. You can use it in
16862 your shell's resource file to enable colors for the prompt and commands
16863 if this variable is set.
16866 (service openssh-service-type
16867 (openssh-configuration
16868 (accepted-environment '("COLORTERM"))))
16871 @item @code{authorized-keys} (default: @code{'()})
16872 @cindex authorized keys, SSH
16873 @cindex SSH authorized keys
16874 This is the list of authorized keys. Each element of the list is a user
16875 name followed by one or more file-like objects that represent SSH public
16879 (openssh-configuration
16881 `(("rekado" ,(local-file "rekado.pub"))
16882 ("chris" ,(local-file "chris.pub"))
16883 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
16887 registers the specified public keys for user accounts @code{rekado},
16888 @code{chris}, and @code{root}.
16890 Additional authorized keys can be specified @i{via}
16891 @code{service-extension}.
16893 Note that this does @emph{not} interfere with the use of
16894 @file{~/.ssh/authorized_keys}.
16896 @item @code{log-level} (default: @code{'info})
16897 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
16898 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
16899 page for @file{sshd_config} for the full list of level names.
16901 @item @code{extra-content} (default: @code{""})
16902 This field can be used to append arbitrary text to the configuration file. It
16903 is especially useful for elaborate configurations that cannot be expressed
16904 otherwise. This configuration, for example, would generally disable root
16905 logins, but permit them from one specific IP address:
16908 (openssh-configuration
16910 Match Address 192.168.0.1
16911 PermitRootLogin yes"))
16917 @deffn {Scheme Procedure} dropbear-service [@var{config}]
16918 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
16919 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
16922 For example, to specify a Dropbear service listening on port 1234, add
16923 this call to the operating system's @code{services} field:
16926 (dropbear-service (dropbear-configuration
16927 (port-number 1234)))
16931 @deftp {Data Type} dropbear-configuration
16932 This data type represents the configuration of a Dropbear SSH daemon.
16935 @item @code{dropbear} (default: @var{dropbear})
16936 The Dropbear package to use.
16938 @item @code{port-number} (default: 22)
16939 The TCP port where the daemon waits for incoming connections.
16941 @item @code{syslog-output?} (default: @code{#t})
16942 Whether to enable syslog output.
16944 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
16945 File name of the daemon's PID file.
16947 @item @code{root-login?} (default: @code{#f})
16948 Whether to allow @code{root} logins.
16950 @item @code{allow-empty-passwords?} (default: @code{#f})
16951 Whether to allow empty passwords.
16953 @item @code{password-authentication?} (default: @code{#t})
16954 Whether to enable password-based authentication.
16959 @deffn {Scheme Variable} autossh-service-type
16960 This is the type for the @uref{https://www.harding.motd.ca/autossh,
16961 AutoSSH} program that runs a copy of @command{ssh} and monitors it,
16962 restarting it as necessary should it die or stop passing traffic.
16963 AutoSSH can be run manually from the command-line by passing arguments
16964 to the binary @command{autossh} from the package @code{autossh}, but it
16965 can also be run as a Guix service. This latter use case is documented
16968 AutoSSH can be used to forward local traffic to a remote machine using
16969 an SSH tunnel, and it respects the @file{~/.ssh/config} of the user it
16972 For example, to specify a service running autossh as the user
16973 @code{pino} and forwarding all local connections to port @code{8081} to
16974 @code{remote:8081} using an SSH tunnel, add this call to the operating
16975 system's @code{services} field:
16978 (service autossh-service-type
16979 (autossh-configuration
16981 (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
16985 @deftp {Data Type} autossh-configuration
16986 This data type represents the configuration of an AutoSSH service.
16990 @item @code{user} (default @code{"autossh"})
16991 The user as which the AutoSSH service is to be run.
16992 This assumes that the specified user exists.
16994 @item @code{poll} (default @code{600})
16995 Specifies the connection poll time in seconds.
16997 @item @code{first-poll} (default @code{#f})
16998 Specifies how many seconds AutoSSH waits before the first connection
16999 test. After this first test, polling is resumed at the pace defined in
17000 @code{poll}. When set to @code{#f}, the first poll is not treated
17001 specially and will also use the connection poll specified in
17004 @item @code{gate-time} (default @code{30})
17005 Specifies how many seconds an SSH connection must be active before it is
17006 considered successful.
17008 @item @code{log-level} (default @code{1})
17009 The log level, corresponding to the levels used by syslog---so @code{0}
17010 is the most silent while @code{7} is the chattiest.
17012 @item @code{max-start} (default @code{#f})
17013 The maximum number of times SSH may be (re)started before AutoSSH exits.
17014 When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
17016 @item @code{message} (default @code{""})
17017 The message to append to the echo message sent when testing connections.
17019 @item @code{port} (default @code{"0"})
17020 The ports used for monitoring the connection. When set to @code{"0"},
17021 monitoring is disabled. When set to @code{"@var{n}"} where @var{n} is
17022 a positive integer, ports @var{n} and @var{n}+1 are used for
17023 monitoring the connection, such that port @var{n} is the base
17024 monitoring port and @code{n+1} is the echo port. When set to
17025 @code{"@var{n}:@var{m}"} where @var{n} and @var{m} are positive
17026 integers, the ports @var{n} and @var{m} are used for monitoring the
17027 connection, such that port @var{n} is the base monitoring port and
17028 @var{m} is the echo port.
17030 @item @code{ssh-options} (default @code{'()})
17031 The list of command-line arguments to pass to @command{ssh} when it is
17032 run. Options @option{-f} and @option{-M} are reserved for AutoSSH and
17033 may cause undefined behaviour.
17039 @deffn {Scheme Variable} webssh-service-type
17040 This is the type for the @uref{https://webssh.huashengdun.org/, WebSSH}
17041 program that runs a web SSH client. WebSSH can be run manually from the
17042 command-line by passing arguments to the binary @command{wssh} from the
17043 package @code{webssh}, but it can also be run as a Guix service. This
17044 latter use case is documented here.
17046 For example, to specify a service running WebSSH on loopback interface
17047 on port @code{8888} with reject policy with a list of allowed to
17048 connection hosts, and NGINX as a reverse-proxy to this service listening
17049 for HTTPS connection, add this call to the operating system's
17050 @code{services} field:
17053 (service webssh-service-type
17054 (webssh-configuration (address "127.0.0.1")
17057 (known-hosts '("localhost ecdsa-sha2-nistp256 AAAA…"
17058 "127.0.0.1 ecdsa-sha2-nistp256 AAAA…"))))
17060 (service nginx-service-type
17061 (nginx-configuration
17064 (nginx-server-configuration
17065 (inherit %webssh-configuration-nginx)
17066 (server-name '("webssh.example.com"))
17067 (listen '("443 ssl"))
17068 (ssl-certificate (letsencrypt-certificate "webssh.example.com"))
17069 (ssl-certificate-key (letsencrypt-key "webssh.example.com"))
17071 (cons (nginx-location-configuration
17072 (uri "/.well-known")
17073 (body '("root /var/www;")))
17074 (nginx-server-configuration-locations %webssh-configuration-nginx))))))))
17078 @deftp {Data Type} webssh-configuration
17079 Data type representing the configuration for @code{webssh-service}.
17082 @item @code{package} (default: @var{webssh})
17083 @code{webssh} package to use.
17085 @item @code{user-name} (default: @var{"webssh"})
17086 User name or user ID that file transfers to and from that module should take
17089 @item @code{group-name} (default: @var{"webssh"})
17090 Group name or group ID that will be used when accessing the module.
17092 @item @code{address} (default: @var{#f})
17093 IP address on which @command{webssh} listens for incoming connections.
17095 @item @code{port} (default: @var{8888})
17096 TCP port on which @command{webssh} listens for incoming connections.
17098 @item @code{policy} (default: @var{#f})
17099 Connection policy. @var{reject} policy requires to specify @var{known-hosts}.
17101 @item @code{known-hosts} (default: @var{'()})
17102 List of hosts which allowed for SSH connection from @command{webssh}.
17104 @item @code{log-file} (default: @file{"/var/log/webssh.log"})
17105 Name of the file where @command{webssh} writes its log file.
17107 @item @code{log-level} (default: @var{#f})
17113 @defvr {Scheme Variable} %facebook-host-aliases
17114 This variable contains a string for use in @file{/etc/hosts}
17115 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
17116 line contains a entry that maps a known server name of the Facebook
17117 on-line service---e.g., @code{www.facebook.com}---to the local
17118 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
17120 This variable is typically used in the @code{hosts-file} field of an
17121 @code{operating-system} declaration (@pxref{operating-system Reference,
17122 @file{/etc/hosts}}):
17125 (use-modules (gnu) (guix))
17128 (host-name "mymachine")
17131 ;; Create a /etc/hosts file with aliases for "localhost"
17132 ;; and "mymachine", as well as for Facebook servers.
17133 (plain-file "hosts"
17134 (string-append (local-host-aliases host-name)
17135 %facebook-host-aliases))))
17138 This mechanism can prevent programs running locally, such as Web
17139 browsers, from accessing Facebook.
17142 The @code{(gnu services avahi)} provides the following definition.
17144 @defvr {Scheme Variable} avahi-service-type
17145 This is the service that runs @command{avahi-daemon}, a system-wide
17146 mDNS/DNS-SD responder that allows for service discovery and
17147 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
17148 Its value must be an @code{avahi-configuration} record---see below.
17150 This service extends the name service cache daemon (nscd) so that it can
17151 resolve @code{.local} host names using
17152 @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
17153 Service Switch}, for information on host name resolution.
17155 Additionally, add the @var{avahi} package to the system profile so that
17156 commands such as @command{avahi-browse} are directly usable.
17159 @deftp {Data Type} avahi-configuration
17160 Data type representation the configuration for Avahi.
17164 @item @code{host-name} (default: @code{#f})
17165 If different from @code{#f}, use that as the host name to
17166 publish for this machine; otherwise, use the machine's actual host name.
17168 @item @code{publish?} (default: @code{#t})
17169 When true, allow host names and services to be published (broadcast) over the
17172 @item @code{publish-workstation?} (default: @code{#t})
17173 When true, @command{avahi-daemon} publishes the machine's host name and IP
17174 address via mDNS on the local network. To view the host names published on
17175 your local network, you can run:
17178 avahi-browse _workstation._tcp
17181 @item @code{wide-area?} (default: @code{#f})
17182 When true, DNS-SD over unicast DNS is enabled.
17184 @item @code{ipv4?} (default: @code{#t})
17185 @itemx @code{ipv6?} (default: @code{#t})
17186 These fields determine whether to use IPv4/IPv6 sockets.
17188 @item @code{domains-to-browse} (default: @code{'()})
17189 This is a list of domains to browse.
17193 @deffn {Scheme Variable} openvswitch-service-type
17194 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
17195 service, whose value should be an @code{openvswitch-configuration}
17199 @deftp {Data Type} openvswitch-configuration
17200 Data type representing the configuration of Open vSwitch, a multilayer
17201 virtual switch which is designed to enable massive network automation
17202 through programmatic extension.
17205 @item @code{package} (default: @var{openvswitch})
17206 Package object of the Open vSwitch.
17211 @defvr {Scheme Variable} pagekite-service-type
17212 This is the service type for the @uref{https://pagekite.net, PageKite} service,
17213 a tunneling solution for making localhost servers publicly visible, even from
17214 behind restrictive firewalls or NAT without forwarded ports. The value for
17215 this service type is a @code{pagekite-configuration} record.
17217 Here's an example exposing the local HTTP and SSH daemons:
17220 (service pagekite-service-type
17221 (pagekite-configuration
17222 (kites '("http:@@kitename:localhost:80:@@kitesecret"
17223 "raw/22:@@kitename:localhost:22:@@kitesecret"))
17224 (extra-file "/etc/pagekite.rc")))
17228 @deftp {Data Type} pagekite-configuration
17229 Data type representing the configuration of PageKite.
17232 @item @code{package} (default: @var{pagekite})
17233 Package object of PageKite.
17235 @item @code{kitename} (default: @code{#f})
17236 PageKite name for authenticating to the frontend server.
17238 @item @code{kitesecret} (default: @code{#f})
17239 Shared secret for authenticating to the frontend server. You should probably
17240 put this inside @code{extra-file} instead.
17242 @item @code{frontend} (default: @code{#f})
17243 Connect to the named PageKite frontend server instead of the
17244 @uref{https://pagekite.net,,pagekite.net} service.
17246 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
17247 List of service kites to use. Exposes HTTP on port 80 by default. The format
17248 is @code{proto:kitename:host:port:secret}.
17250 @item @code{extra-file} (default: @code{#f})
17251 Extra configuration file to read, which you are expected to create manually.
17252 Use this to add additional options and manage shared secrets out-of-band.
17257 @defvr {Scheme Variable} yggdrasil-service-type
17258 The service type for connecting to the @uref{https://yggdrasil-network.github.io/,
17259 Yggdrasil network}, an early-stage implementation of a fully end-to-end
17260 encrypted IPv6 network.
17263 Yggdrasil provides name-independent routing with cryptographically generated
17264 addresses. Static addressing means you can keep the same address as long as
17265 you want, even if you move to a new location, or generate a new address (by
17266 generating new keys) whenever you want.
17267 @uref{https://yggdrasil-network.github.io/2018/07/28/addressing.html}
17270 Pass it a value of @code{yggdrasil-configuration} to connect it to public
17271 peers and/or local peers.
17273 Here is an example using public peers and a static address. The static
17274 signing and encryption keys are defined in @file{/etc/yggdrasil-private.conf}
17275 (the default value for @code{config-file}).
17278 ;; part of the operating-system declaration
17279 (service yggdrasil-service-type
17280 (yggdrasil-configuration
17281 (autoconf? #f) ;; use only the public peers
17284 ;; https://github.com/yggdrasil-network/public-peers
17285 '((peers . #("tcp://1.2.3.4:1337"))))
17286 ;; /etc/yggdrasil-private.conf is the default value for config-file
17290 # sample content for /etc/yggdrasil-private.conf
17292 # Your public encryption key. Your peers may ask you for this to put
17293 # into their AllowedEncryptionPublicKeys configuration.
17294 EncryptionPublicKey: 378dc5...
17296 # Your private encryption key. DO NOT share this with anyone!
17297 EncryptionPrivateKey: 0777...
17299 # Your public signing key. You should not ordinarily need to share
17300 # this with anyone.
17301 SigningPublicKey: e1664...
17303 # Your private signing key. DO NOT share this with anyone!
17304 SigningPrivateKey: 0589d...
17309 @deftp {Data Type} yggdrasil-configuration
17310 Data type representing the configuration of Yggdrasil.
17313 @item @code{package} (default: @code{yggdrasil})
17314 Package object of Yggdrasil.
17316 @item @code{json-config} (default: @code{'()})
17317 Contents of @file{/etc/yggdrasil.conf}. Will be merged with
17318 @file{/etc/yggdrasil-private.conf}. Note that these settings are stored in
17319 the Guix store, which is readable to all users. @strong{Do not store your
17320 private keys in it}. See the output of @code{yggdrasil -genconf} for a
17321 quick overview of valid keys and their default values.
17323 @item @code{autoconf?} (default: @code{#f})
17324 Whether to use automatic mode. Enabling it makes Yggdrasil use adynamic IP
17325 and peer with IPv6 neighbors.
17327 @item @code{log-level} (default: @code{'info})
17328 How much detail to include in logs. Use @code{'debug} for more detail.
17330 @item @code{log-to} (default: @code{'stdout})
17331 Where to send logs. By default, the service logs standard output to
17332 @file{/var/log/yggdrasil.log}. The alternative is @code{'syslog}, which
17333 sends output to the running syslog service.
17335 @item @code{config-file} (default: @code{"/etc/yggdrasil-private.conf"})
17336 What HJSON file to load sensitive data from. This is where private keys
17337 should be stored, which are necessary to specify if you don't want a
17338 randomized address after each restart. Use @code{#f} to disable. Options
17339 defined in this file take precedence over @code{json-config}. Use the output
17340 of @code{yggdrasil -genconf} as a starting point. To configure a static
17341 address, delete everything except these options:
17344 @item @code{EncryptionPublicKey}
17345 @item @code{EncryptionPrivateKey}
17346 @item @code{SigningPublicKey}
17347 @item @code{SigningPrivateKey}
17353 @deffn {Scheme Variable} keepalived-service-type
17354 This is the type for the @uref{https://www.keepalived.org/, Keepalived}
17355 routing software, @command{keepalived}. Its value must be an
17356 @code{keepalived-configuration} record as in this example for master
17360 (service keepalived-service-type
17361 (keepalived-configuration
17362 (config-file (local-file "keepalived-master.conf"))))
17365 where @file{keepalived-master.conf}:
17368 vrrp_instance my-group @{
17371 virtual_router_id 100
17373 unicast_peer @{ 10.0.0.2 @}
17374 virtual_ipaddress @{
17380 and for backup machine:
17383 (service keepalived-service-type
17384 (keepalived-configuration
17385 (config-file (local-file "keepalived-backup.conf"))))
17388 where @file{keepalived-backup.conf}:
17391 vrrp_instance my-group @{
17394 virtual_router_id 100
17396 unicast_peer @{ 10.0.0.3 @}
17397 virtual_ipaddress @{
17404 @node Unattended Upgrades
17405 @subsection Unattended Upgrades
17407 @cindex unattended upgrades
17408 @cindex upgrades, unattended
17409 Guix provides a service to perform @emph{unattended upgrades}:
17410 periodically, the system automatically reconfigures itself from the
17411 latest Guix. Guix System has several properties that make unattended
17416 upgrades are transactional (either the upgrade succeeds or it fails, but
17417 you cannot end up with an ``in-between'' system state);
17419 the upgrade log is kept---you can view it with @command{guix system
17420 list-generations}---and you can roll back to any previous generation,
17421 should the upgraded system fail to behave as intended;
17423 channel code is authenticated so you know you can only run genuine code
17424 (@pxref{Channels});
17426 @command{guix system reconfigure} prevents downgrades, which makes it
17427 immune to @dfn{downgrade attacks}.
17430 To set up unattended upgrades, add an instance of
17431 @code{unattended-upgrade-service-type} like the one below to the list of
17432 your operating system services:
17435 (service unattended-upgrade-service-type)
17438 The defaults above set up weekly upgrades: every Sunday at midnight.
17439 You do not need to provide the operating system configuration file: it
17440 uses @file{/run/current-system/configuration.scm}, which ensures it
17441 always uses your latest configuration---@pxref{provenance-service-type},
17442 for more information about this file.
17444 There are several things that can be configured, in particular the
17445 periodicity and services (daemons) to be restarted upon completion.
17446 When the upgrade is successful, the service takes care of deleting
17447 system generations older that some threshold, as per @command{guix
17448 system delete-generations}. See the reference below for details.
17450 To ensure that upgrades are actually happening, you can run
17451 @command{guix system describe}. To investigate upgrade failures, visit
17452 the unattended upgrade log file (see below).
17454 @defvr {Scheme Variable} unattended-upgrade-service-type
17455 This is the service type for unattended upgrades. It sets up an mcron
17456 job (@pxref{Scheduled Job Execution}) that runs @command{guix system
17457 reconfigure} from the latest version of the specified channels.
17459 Its value must be a @code{unattended-upgrade-configuration} record (see
17463 @deftp {Data Type} unattended-upgrade-configuration
17464 This data type represents the configuration of the unattended upgrade
17465 service. The following fields are available:
17468 @item @code{schedule} (default: @code{"30 01 * * 0"})
17469 This is the schedule of upgrades, expressed as a gexp containing an
17470 mcron job schedule (@pxref{Guile Syntax, mcron job specifications,,
17471 mcron, GNU@tie{}mcron}).
17473 @item @code{channels} (default: @code{#~%default-channels})
17474 This gexp specifies the channels to use for the upgrade
17475 (@pxref{Channels}). By default, the tip of the official @code{guix}
17478 @item @code{operating-system-file} (default: @code{"/run/current-system/configuration.scm"})
17479 This field specifies the operating system configuration file to use.
17480 The default is to reuse the config file of the current configuration.
17482 There are cases, though, where referring to
17483 @file{/run/current-system/configuration.scm} is not enough, for instance
17484 because that file refers to extra files (SSH public keys, extra
17485 configuration files, etc.) @i{via} @code{local-file} and similar
17486 constructs. For those cases, we recommend something along these lines:
17489 (unattended-upgrade-configuration
17490 (operating-system-file
17491 (file-append (local-file "." "config-dir" #:recursive? #t)
17495 The effect here is to import all of the current directory into the
17496 store, and to refer to @file{config.scm} within that directory.
17497 Therefore, uses of @code{local-file} within @file{config.scm} will work
17498 as expected. @xref{G-Expressions}, for information about
17499 @code{local-file} and @code{file-append}.
17501 @item @code{services-to-restart} (default: @code{'(mcron)})
17502 This field specifies the Shepherd services to restart when the upgrade
17505 Those services are restarted right away upon completion, as with
17506 @command{herd restart}, which ensures that the latest version is
17507 running---remember that by default @command{guix system reconfigure}
17508 only restarts services that are not currently running, which is
17509 conservative: it minimizes disruption but leaves outdated services
17512 Use @command{herd status} to find out candidates for restarting.
17513 @xref{Services}, for general information about services. Common
17514 services to restart would include @code{ntpd} and @code{ssh-daemon}.
17516 By default, the @code{mcron} service is restarted. This ensures that
17517 the latest version of the unattended upgrade job will be used next time.
17519 @item @code{system-expiration} (default: @code{(* 3 30 24 3600)})
17520 This is the expiration time in seconds for system generations. System
17521 generations older that this amount of time are deleted with
17522 @command{guix system delete-generations} when an upgrade completes.
17525 The unattended upgrade service does not run the garbage collector. You
17526 will probably want to set up your own mcron job to run @command{guix gc}
17530 @item @code{maximum-duration} (default: @code{3600})
17531 Maximum duration in seconds for the upgrade; past that time, the upgrade
17534 This is primarily useful to ensure the upgrade does not end up
17535 rebuilding or re-downloading ``the world''.
17537 @item @code{log-file} (default: @code{"/var/log/unattended-upgrade.log"})
17538 File where unattended upgrades are logged.
17543 @subsection X Window
17546 @cindex X Window System
17547 @cindex login manager
17548 Support for the X Window graphical display system---specifically
17549 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
17550 there is no @code{xorg-service} procedure. Instead, the X server is
17551 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
17554 @cindex GNOME, login manager
17555 GDM of course allows users to log in into window managers and desktop
17556 environments other than GNOME; for those using GNOME, GDM is required for
17557 features such as automatic screen locking.
17559 @cindex window manager
17560 To use X11, you must install at least one @dfn{window manager}---for
17561 example the @code{windowmaker} or @code{openbox} packages---preferably
17562 by adding it to the @code{packages} field of your operating system
17563 definition (@pxref{operating-system Reference, system-wide packages}).
17565 @defvr {Scheme Variable} gdm-service-type
17566 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
17567 Desktop Manager} (GDM), a program that manages graphical display servers and
17568 handles graphical user logins. Its value must be a @code{gdm-configuration}
17571 @cindex session types (X11)
17572 @cindex X11 session types
17573 GDM looks for @dfn{session types} described by the @file{.desktop} files in
17574 @file{/run/current-system/profile/share/xsessions} and allows users to choose
17575 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
17576 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
17577 set of packages automatically makes them available at the log-in screen.
17579 In addition, @file{~/.xsession} files are honored. When available,
17580 @file{~/.xsession} must be an executable that starts a window manager
17581 and/or other X clients.
17584 @deftp {Data Type} gdm-configuration
17586 @item @code{auto-login?} (default: @code{#f})
17587 @itemx @code{default-user} (default: @code{#f})
17588 When @code{auto-login?} is false, GDM presents a log-in screen.
17590 When @code{auto-login?} is true, GDM logs in directly as
17591 @code{default-user}.
17593 @item @code{debug?} (default: @code{#f})
17594 When true, GDM writes debug messages to its log.
17596 @item @code{gnome-shell-assets} (default: ...)
17597 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
17599 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
17600 Configuration of the Xorg graphical server.
17602 @item @code{xsession} (default: @code{(xinitrc)})
17603 Script to run before starting a X session.
17605 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
17606 File name of the @code{dbus-daemon} executable.
17608 @item @code{gdm} (default: @code{gdm})
17609 The GDM package to use.
17613 @defvr {Scheme Variable} slim-service-type
17614 This is the type for the SLiM graphical login manager for X11.
17616 Like GDM, SLiM looks for session types described by @file{.desktop} files and
17617 allows users to choose a session from the log-in screen using @kbd{F1}. It
17618 also honors @file{~/.xsession} files.
17620 Unlike GDM, SLiM does not spawn the user session on a different VT after
17621 logging in, which means that you can only start one graphical session. If you
17622 want to be able to run multiple graphical sessions at the same time you have
17623 to add multiple SLiM services to your system services. The following example
17624 shows how to replace the default GDM service with two SLiM services on tty7
17628 (use-modules (gnu services)
17629 (gnu services desktop)
17630 (gnu services xorg)
17631 (srfi srfi-1)) ;for 'remove'
17635 (services (cons* (service slim-service-type (slim-configuration
17638 (service slim-service-type (slim-configuration
17641 (remove (lambda (service)
17642 (eq? (service-kind service) gdm-service-type))
17643 %desktop-services))))
17648 @deftp {Data Type} slim-configuration
17649 Data type representing the configuration of @code{slim-service-type}.
17652 @item @code{allow-empty-passwords?} (default: @code{#t})
17653 Whether to allow logins with empty passwords.
17655 @item @code{auto-login?} (default: @code{#f})
17656 @itemx @code{default-user} (default: @code{""})
17657 When @code{auto-login?} is false, SLiM presents a log-in screen.
17659 When @code{auto-login?} is true, SLiM logs in directly as
17660 @code{default-user}.
17662 @item @code{theme} (default: @code{%default-slim-theme})
17663 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
17664 The graphical theme to use and its name.
17666 @item @code{auto-login-session} (default: @code{#f})
17667 If true, this must be the name of the executable to start as the default
17668 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
17670 If false, a session described by one of the available @file{.desktop}
17671 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
17675 You must install at least one window manager in the system profile or in
17676 your user profile. Failing to do that, if @code{auto-login-session} is
17677 false, you will be unable to log in.
17680 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
17681 Configuration of the Xorg graphical server.
17683 @item @code{display} (default @code{":0"})
17684 The display on which to start the Xorg graphical server.
17686 @item @code{vt} (default @code{"vt7"})
17687 The VT on which to start the Xorg graphical server.
17689 @item @code{xauth} (default: @code{xauth})
17690 The XAuth package to use.
17692 @item @code{shepherd} (default: @code{shepherd})
17693 The Shepherd package used when invoking @command{halt} and
17696 @item @code{sessreg} (default: @code{sessreg})
17697 The sessreg package used in order to register the session.
17699 @item @code{slim} (default: @code{slim})
17700 The SLiM package to use.
17704 @defvr {Scheme Variable} %default-theme
17705 @defvrx {Scheme Variable} %default-theme-name
17706 The default SLiM theme and its name.
17710 @deftp {Data Type} sddm-configuration
17711 This is the data type representing the SDDM service configuration.
17714 @item @code{display-server} (default: "x11")
17715 Select display server to use for the greeter. Valid values are
17716 @samp{"x11"} or @samp{"wayland"}.
17718 @item @code{numlock} (default: "on")
17719 Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
17721 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
17722 Command to run when halting.
17724 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
17725 Command to run when rebooting.
17727 @item @code{theme} (default "maldives")
17728 Theme to use. Default themes provided by SDDM are @samp{"elarun"},
17729 @samp{"maldives"} or @samp{"maya"}.
17731 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
17732 Directory to look for themes.
17734 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
17735 Directory to look for faces.
17737 @item @code{default-path} (default "/run/current-system/profile/bin")
17738 Default PATH to use.
17740 @item @code{minimum-uid} (default: 1000)
17741 Minimum UID displayed in SDDM and allowed for log-in.
17743 @item @code{maximum-uid} (default: 2000)
17744 Maximum UID to display in SDDM.
17746 @item @code{remember-last-user?} (default #t)
17747 Remember last user.
17749 @item @code{remember-last-session?} (default #t)
17750 Remember last session.
17752 @item @code{hide-users} (default "")
17753 Usernames to hide from SDDM greeter.
17755 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
17756 Users with shells listed will be hidden from the SDDM greeter.
17758 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
17759 Script to run before starting a wayland session.
17761 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
17762 Directory to look for desktop files starting wayland sessions.
17764 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
17765 Configuration of the Xorg graphical server.
17767 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
17770 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
17773 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
17774 Script to run after starting xorg-server.
17776 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
17777 Script to run before stopping xorg-server.
17779 @item @code{xsession-command} (default: @code{xinitrc})
17780 Script to run before starting a X session.
17782 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
17783 Directory to look for desktop files starting X sessions.
17785 @item @code{minimum-vt} (default: 7)
17788 @item @code{auto-login-user} (default "")
17789 User to use for auto-login.
17791 @item @code{auto-login-session} (default "")
17792 Desktop file to use for auto-login.
17794 @item @code{relogin?} (default #f)
17795 Relogin after logout.
17800 @cindex login manager
17802 @defvr {Scheme Variable} sddm-service-type
17803 This is the type of the service to run the
17804 @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
17805 must be a @code{sddm-configuration} record (see below).
17807 Here's an example use:
17810 (service sddm-service-type
17811 (sddm-configuration
17812 (auto-login-user "alice")
17813 (auto-login-session "xfce.desktop")))
17817 @deftp {Data Type} sddm-configuration
17818 This data type represents the configuration of the SDDM login manager.
17819 The available fields are:
17822 @item @code{sddm} (default: @code{sddm})
17823 The SDDM package to use.
17825 @item @code{display-server} (default: @code{"x11"})
17826 This must be either @code{"x11"} or @code{"wayland"}.
17828 @c FIXME: Add more fields.
17830 @item @code{auto-login-user} (default: @code{""})
17831 If non-empty, this is the user account under which to log in
17834 @item @code{auto-login-session} (default: @code{""})
17835 If non-empty, this is the @file{.desktop} file name to use as the
17836 auto-login session.
17840 @cindex Xorg, configuration
17841 @deftp {Data Type} xorg-configuration
17842 This data type represents the configuration of the Xorg graphical display
17843 server. Note that there is no Xorg service; instead, the X server is started
17844 by a ``display manager'' such as GDM, SDDM, and SLiM@. Thus, the configuration
17845 of these display managers aggregates an @code{xorg-configuration} record.
17848 @item @code{modules} (default: @code{%default-xorg-modules})
17849 This is a list of @dfn{module packages} loaded by the Xorg
17850 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
17852 @item @code{fonts} (default: @code{%default-xorg-fonts})
17853 This is a list of font directories to add to the server's @dfn{font path}.
17855 @item @code{drivers} (default: @code{'()})
17856 This must be either the empty list, in which case Xorg chooses a graphics
17857 driver automatically, or a list of driver names that will be tried in this
17858 order---e.g., @code{("modesetting" "vesa")}.
17860 @item @code{resolutions} (default: @code{'()})
17861 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
17862 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
17865 @cindex keyboard layout, for Xorg
17866 @cindex keymap, for Xorg
17867 @item @code{keyboard-layout} (default: @code{#f})
17868 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
17869 English (``qwerty'') for a 105-key PC keyboard.
17871 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
17872 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
17873 information on how to specify the keyboard layout.
17875 @item @code{extra-config} (default: @code{'()})
17876 This is a list of strings or objects appended to the configuration file. It
17877 is used to pass extra text to be added verbatim to the configuration file.
17879 @item @code{server} (default: @code{xorg-server})
17880 This is the package providing the Xorg server.
17882 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
17883 This is the list of command-line arguments to pass to the X server. The
17884 default is @code{-nolisten tcp}.
17888 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
17889 [@var{login-manager-service-type}]
17890 Tell the log-in manager (of type @var{login-manager-service-type}) to use
17891 @var{config}, an @code{<xorg-configuration>} record.
17893 Since the Xorg configuration is embedded in the log-in manager's
17894 configuration---e.g., @code{gdm-configuration}---this procedure provides a
17895 shorthand to set the Xorg configuration.
17898 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
17899 Return a @code{startx} script in which the modules, fonts, etc. specified
17900 in @var{config}, are available. The result should be used in place of
17903 Usually the X server is started by a login manager.
17907 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
17908 Add @var{package}, a package for a screen locker or screen saver whose
17909 command is @var{program}, to the set of setuid programs and add a PAM entry
17910 for it. For example:
17913 (screen-locker-service xlockmore "xlock")
17916 makes the good ol' XlockMore usable.
17920 @node Printing Services
17921 @subsection Printing Services
17923 @cindex printer support with CUPS
17924 The @code{(gnu services cups)} module provides a Guix service definition
17925 for the CUPS printing service. To add printer support to a Guix
17926 system, add a @code{cups-service} to the operating system definition:
17928 @deffn {Scheme Variable} cups-service-type
17929 The service type for the CUPS print server. Its value should be a valid
17930 CUPS configuration (see below). To use the default settings, simply
17933 (service cups-service-type)
17937 The CUPS configuration controls the basic things about your CUPS
17938 installation: what interfaces it listens on, what to do if a print job
17939 fails, how much logging to do, and so on. To actually add a printer,
17940 you have to visit the @url{http://localhost:631} URL, or use a tool such
17941 as GNOME's printer configuration services. By default, configuring a
17942 CUPS service will generate a self-signed certificate if needed, for
17943 secure connections to the print server.
17945 Suppose you want to enable the Web interface of CUPS and also add
17946 support for Epson printers @i{via} the @code{epson-inkjet-printer-escpr}
17947 package and for HP printers @i{via} the @code{hplip-minimal} package.
17948 You can do that directly, like this (you need to use the
17949 @code{(gnu packages cups)} module):
17952 (service cups-service-type
17953 (cups-configuration
17954 (web-interface? #t)
17956 (list cups-filters epson-inkjet-printer-escpr hplip-minimal))))
17959 Note: If you wish to use the Qt5 based GUI which comes with the hplip
17960 package then it is suggested that you install the @code{hplip} package,
17961 either in your OS configuration file or as your user.
17963 The available configuration parameters follow. Each parameter
17964 definition is preceded by its type; for example, @samp{string-list foo}
17965 indicates that the @code{foo} parameter should be specified as a list of
17966 strings. There is also a way to specify the configuration as a string,
17967 if you have an old @code{cupsd.conf} file that you want to port over
17968 from some other system; see the end for more details.
17970 @c The following documentation was initially generated by
17971 @c (generate-documentation) in (gnu services cups). Manually maintained
17972 @c documentation is better, so we shouldn't hesitate to edit below as
17973 @c needed. However if the change you want to make to this documentation
17974 @c can be done in an automated way, it's probably easier to change
17975 @c (generate-documentation) than to make it below and have to deal with
17976 @c the churn as CUPS updates.
17979 Available @code{cups-configuration} fields are:
17981 @deftypevr {@code{cups-configuration} parameter} package cups
17985 @deftypevr {@code{cups-configuration} parameter} package-list extensions (default: @code{(list brlaser cups-filters epson-inkjet-printer-escpr foomatic-filters hplip-minimal splix)})
17986 Drivers and other extensions to the CUPS package.
17989 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
17990 Configuration of where to write logs, what directories to use for print
17991 spools, and related privileged configuration parameters.
17993 Available @code{files-configuration} fields are:
17995 @deftypevr {@code{files-configuration} parameter} log-location access-log
17996 Defines the access log filename. Specifying a blank filename disables
17997 access log generation. The value @code{stderr} causes log entries to be
17998 sent to the standard error file when the scheduler is running in the
17999 foreground, or to the system log daemon when run in the background. The
18000 value @code{syslog} causes log entries to be sent to the system log
18001 daemon. The server name may be included in filenames using the string
18002 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
18004 Defaults to @samp{"/var/log/cups/access_log"}.
18007 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
18008 Where CUPS should cache data.
18010 Defaults to @samp{"/var/cache/cups"}.
18013 @deftypevr {@code{files-configuration} parameter} string config-file-perm
18014 Specifies the permissions for all configuration files that the scheduler
18017 Note that the permissions for the printers.conf file are currently
18018 masked to only allow access from the scheduler user (typically root).
18019 This is done because printer device URIs sometimes contain sensitive
18020 authentication information that should not be generally known on the
18021 system. There is no way to disable this security feature.
18023 Defaults to @samp{"0640"}.
18026 @deftypevr {@code{files-configuration} parameter} log-location error-log
18027 Defines the error log filename. Specifying a blank filename disables
18028 error log generation. The value @code{stderr} causes log entries to be
18029 sent to the standard error file when the scheduler is running in the
18030 foreground, or to the system log daemon when run in the background. The
18031 value @code{syslog} causes log entries to be sent to the system log
18032 daemon. The server name may be included in filenames using the string
18033 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
18035 Defaults to @samp{"/var/log/cups/error_log"}.
18038 @deftypevr {@code{files-configuration} parameter} string fatal-errors
18039 Specifies which errors are fatal, causing the scheduler to exit. The
18044 No errors are fatal.
18047 All of the errors below are fatal.
18050 Browsing initialization errors are fatal, for example failed connections
18051 to the DNS-SD daemon.
18054 Configuration file syntax errors are fatal.
18057 Listen or Port errors are fatal, except for IPv6 failures on the
18058 loopback or @code{any} addresses.
18061 Log file creation or write errors are fatal.
18064 Bad startup file permissions are fatal, for example shared TLS
18065 certificate and key files with world-read permissions.
18068 Defaults to @samp{"all -browse"}.
18071 @deftypevr {@code{files-configuration} parameter} boolean file-device?
18072 Specifies whether the file pseudo-device can be used for new printer
18073 queues. The URI @uref{file:///dev/null} is always allowed.
18075 Defaults to @samp{#f}.
18078 @deftypevr {@code{files-configuration} parameter} string group
18079 Specifies the group name or ID that will be used when executing external
18082 Defaults to @samp{"lp"}.
18085 @deftypevr {@code{files-configuration} parameter} string log-file-perm
18086 Specifies the permissions for all log files that the scheduler writes.
18088 Defaults to @samp{"0644"}.
18091 @deftypevr {@code{files-configuration} parameter} log-location page-log
18092 Defines the page log filename. Specifying a blank filename disables
18093 page log generation. The value @code{stderr} causes log entries to be
18094 sent to the standard error file when the scheduler is running in the
18095 foreground, or to the system log daemon when run in the background. The
18096 value @code{syslog} causes log entries to be sent to the system log
18097 daemon. The server name may be included in filenames using the string
18098 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
18100 Defaults to @samp{"/var/log/cups/page_log"}.
18103 @deftypevr {@code{files-configuration} parameter} string remote-root
18104 Specifies the username that is associated with unauthenticated accesses
18105 by clients claiming to be the root user. The default is @code{remroot}.
18107 Defaults to @samp{"remroot"}.
18110 @deftypevr {@code{files-configuration} parameter} file-name request-root
18111 Specifies the directory that contains print jobs and other HTTP request
18114 Defaults to @samp{"/var/spool/cups"}.
18117 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
18118 Specifies the level of security sandboxing that is applied to print
18119 filters, backends, and other child processes of the scheduler; either
18120 @code{relaxed} or @code{strict}. This directive is currently only
18121 used/supported on macOS.
18123 Defaults to @samp{strict}.
18126 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
18127 Specifies the location of TLS certificates and private keys. CUPS will
18128 look for public and private keys in this directory: @file{.crt} files
18129 for PEM-encoded certificates and corresponding @file{.key} files for
18130 PEM-encoded private keys.
18132 Defaults to @samp{"/etc/cups/ssl"}.
18135 @deftypevr {@code{files-configuration} parameter} file-name server-root
18136 Specifies the directory containing the server configuration files.
18138 Defaults to @samp{"/etc/cups"}.
18141 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
18142 Specifies whether the scheduler calls fsync(2) after writing
18143 configuration or state files.
18145 Defaults to @samp{#f}.
18148 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
18149 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
18152 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
18153 Specifies the directory where temporary files are stored.
18155 Defaults to @samp{"/var/spool/cups/tmp"}.
18158 @deftypevr {@code{files-configuration} parameter} string user
18159 Specifies the user name or ID that is used when running external
18162 Defaults to @samp{"lp"}.
18165 @deftypevr {@code{files-configuration} parameter} string set-env
18166 Set the specified environment variable to be passed to child processes.
18168 Defaults to @samp{"variable value"}.
18172 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
18173 Specifies the logging level for the AccessLog file. The @code{config}
18174 level logs when printers and classes are added, deleted, or modified and
18175 when configuration files are accessed or updated. The @code{actions}
18176 level logs when print jobs are submitted, held, released, modified, or
18177 canceled, and any of the conditions for @code{config}. The @code{all}
18178 level logs all requests.
18180 Defaults to @samp{actions}.
18183 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
18184 Specifies whether to purge job history data automatically when it is no
18185 longer required for quotas.
18187 Defaults to @samp{#f}.
18190 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
18191 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
18192 For example, @samp{"_cups" "_print"} will tell network clients that both
18193 CUPS sharing and IPP Everywhere are supported.
18195 Defaults to @samp{"_cups"}.
18198 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
18199 Specifies which protocols to use for local printer sharing.
18201 Defaults to @samp{dnssd}.
18204 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
18205 Specifies whether the CUPS web interface is advertised.
18207 Defaults to @samp{#f}.
18210 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
18211 Specifies whether shared printers are advertised.
18213 Defaults to @samp{#f}.
18216 @deftypevr {@code{cups-configuration} parameter} string classification
18217 Specifies the security classification of the server. Any valid banner
18218 name can be used, including @samp{"classified"}, @samp{"confidential"},
18219 @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
18220 banner can be omitted to disable secure printing functions.
18222 Defaults to @samp{""}.
18225 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
18226 Specifies whether users may override the classification (cover page) of
18227 individual print jobs using the @code{job-sheets} option.
18229 Defaults to @samp{#f}.
18232 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
18233 Specifies the default type of authentication to use.
18235 Defaults to @samp{Basic}.
18238 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
18239 Specifies whether encryption will be used for authenticated requests.
18241 Defaults to @samp{Required}.
18244 @deftypevr {@code{cups-configuration} parameter} string default-language
18245 Specifies the default language to use for text and web content.
18247 Defaults to @samp{"en"}.
18250 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
18251 Specifies the default paper size for new print queues. @samp{"Auto"}
18252 uses a locale-specific default, while @samp{"None"} specifies there is
18253 no default paper size. Specific size names are typically
18254 @samp{"Letter"} or @samp{"A4"}.
18256 Defaults to @samp{"Auto"}.
18259 @deftypevr {@code{cups-configuration} parameter} string default-policy
18260 Specifies the default access policy to use.
18262 Defaults to @samp{"default"}.
18265 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
18266 Specifies whether local printers are shared by default.
18268 Defaults to @samp{#t}.
18271 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
18272 Specifies the delay for updating of configuration and state files, in
18273 seconds. A value of 0 causes the update to happen as soon as possible,
18274 typically within a few milliseconds.
18276 Defaults to @samp{30}.
18279 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
18280 Specifies what to do when an error occurs. Possible values are
18281 @code{abort-job}, which will discard the failed print job;
18282 @code{retry-job}, which will retry the job at a later time;
18283 @code{retry-current-job}, which retries the failed job immediately; and
18284 @code{stop-printer}, which stops the printer.
18286 Defaults to @samp{stop-printer}.
18289 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
18290 Specifies the maximum cost of filters that are run concurrently, which
18291 can be used to minimize disk, memory, and CPU resource problems. A
18292 limit of 0 disables filter limiting. An average print to a
18293 non-PostScript printer needs a filter limit of about 200. A PostScript
18294 printer needs about half that (100). Setting the limit below these
18295 thresholds will effectively limit the scheduler to printing a single job
18298 Defaults to @samp{0}.
18301 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
18302 Specifies the scheduling priority of filters that are run to print a
18303 job. The nice value ranges from 0, the highest priority, to 19, the
18306 Defaults to @samp{0}.
18309 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
18310 Specifies whether to do reverse lookups on connecting clients. The
18311 @code{double} setting causes @code{cupsd} to verify that the hostname
18312 resolved from the address matches one of the addresses returned for that
18313 hostname. Double lookups also prevent clients with unregistered
18314 addresses from connecting to your server. Only set this option to
18315 @code{#t} or @code{double} if absolutely required.
18317 Defaults to @samp{#f}.
18320 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
18321 Specifies the number of seconds to wait before killing the filters and
18322 backend associated with a canceled or held job.
18324 Defaults to @samp{30}.
18327 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
18328 Specifies the interval between retries of jobs in seconds. This is
18329 typically used for fax queues but can also be used with normal print
18330 queues whose error policy is @code{retry-job} or
18331 @code{retry-current-job}.
18333 Defaults to @samp{30}.
18336 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
18337 Specifies the number of retries that are done for jobs. This is
18338 typically used for fax queues but can also be used with normal print
18339 queues whose error policy is @code{retry-job} or
18340 @code{retry-current-job}.
18342 Defaults to @samp{5}.
18345 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
18346 Specifies whether to support HTTP keep-alive connections.
18348 Defaults to @samp{#t}.
18351 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
18352 Specifies how long an idle client connection remains open, in seconds.
18354 Defaults to @samp{30}.
18357 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
18358 Specifies the maximum size of print files, IPP requests, and HTML form
18359 data. A limit of 0 disables the limit check.
18361 Defaults to @samp{0}.
18364 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
18365 Listens on the specified interfaces for connections. Valid values are
18366 of the form @var{address}:@var{port}, where @var{address} is either an
18367 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
18368 indicate all addresses. Values can also be file names of local UNIX
18369 domain sockets. The Listen directive is similar to the Port directive
18370 but allows you to restrict access to specific interfaces or networks.
18373 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
18374 Specifies the number of pending connections that will be allowed. This
18375 normally only affects very busy servers that have reached the MaxClients
18376 limit, but can also be triggered by large numbers of simultaneous
18377 connections. When the limit is reached, the operating system will
18378 refuse additional connections until the scheduler can accept the pending
18381 Defaults to @samp{128}.
18384 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
18385 Specifies a set of additional access controls.
18387 Available @code{location-access-controls} fields are:
18389 @deftypevr {@code{location-access-controls} parameter} file-name path
18390 Specifies the URI path to which the access control applies.
18393 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
18394 Access controls for all access to this path, in the same format as the
18395 @code{access-controls} of @code{operation-access-control}.
18397 Defaults to @samp{()}.
18400 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
18401 Access controls for method-specific access to this path.
18403 Defaults to @samp{()}.
18405 Available @code{method-access-controls} fields are:
18407 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
18408 If @code{#t}, apply access controls to all methods except the listed
18409 methods. Otherwise apply to only the listed methods.
18411 Defaults to @samp{#f}.
18414 @deftypevr {@code{method-access-controls} parameter} method-list methods
18415 Methods to which this access control applies.
18417 Defaults to @samp{()}.
18420 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
18421 Access control directives, as a list of strings. Each string should be
18422 one directive, such as @samp{"Order allow,deny"}.
18424 Defaults to @samp{()}.
18429 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
18430 Specifies the number of debugging messages that are retained for logging
18431 if an error occurs in a print job. Debug messages are logged regardless
18432 of the LogLevel setting.
18434 Defaults to @samp{100}.
18437 @deftypevr {@code{cups-configuration} parameter} log-level log-level
18438 Specifies the level of logging for the ErrorLog file. The value
18439 @code{none} stops all logging while @code{debug2} logs everything.
18441 Defaults to @samp{info}.
18444 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
18445 Specifies the format of the date and time in the log files. The value
18446 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
18448 Defaults to @samp{standard}.
18451 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
18452 Specifies the maximum number of simultaneous clients that are allowed by
18455 Defaults to @samp{100}.
18458 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
18459 Specifies the maximum number of simultaneous clients that are allowed
18460 from a single address.
18462 Defaults to @samp{100}.
18465 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
18466 Specifies the maximum number of copies that a user can print of each
18469 Defaults to @samp{9999}.
18472 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
18473 Specifies the maximum time a job may remain in the @code{indefinite}
18474 hold state before it is canceled. A value of 0 disables cancellation of
18477 Defaults to @samp{0}.
18480 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
18481 Specifies the maximum number of simultaneous jobs that are allowed. Set
18482 to 0 to allow an unlimited number of jobs.
18484 Defaults to @samp{500}.
18487 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
18488 Specifies the maximum number of simultaneous jobs that are allowed per
18489 printer. A value of 0 allows up to MaxJobs jobs per printer.
18491 Defaults to @samp{0}.
18494 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
18495 Specifies the maximum number of simultaneous jobs that are allowed per
18496 user. A value of 0 allows up to MaxJobs jobs per user.
18498 Defaults to @samp{0}.
18501 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
18502 Specifies the maximum time a job may take to print before it is
18503 canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
18505 Defaults to @samp{10800}.
18508 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
18509 Specifies the maximum size of the log files before they are rotated, in
18510 bytes. The value 0 disables log rotation.
18512 Defaults to @samp{1048576}.
18515 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
18516 Specifies the maximum amount of time to allow between files in a
18517 multiple file print job, in seconds.
18519 Defaults to @samp{300}.
18522 @deftypevr {@code{cups-configuration} parameter} string page-log-format
18523 Specifies the format of PageLog lines. Sequences beginning with percent
18524 (@samp{%}) characters are replaced with the corresponding information,
18525 while all other characters are copied literally. The following percent
18526 sequences are recognized:
18530 insert a single percent character
18533 insert the value of the specified IPP attribute
18536 insert the number of copies for the current page
18539 insert the current page number
18542 insert the current date and time in common log format
18548 insert the printer name
18551 insert the username
18554 A value of the empty string disables page logging. The string @code{%p
18555 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
18556 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
18559 Defaults to @samp{""}.
18562 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
18563 Passes the specified environment variable(s) to child processes; a list
18566 Defaults to @samp{()}.
18569 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
18570 Specifies named access control policies.
18572 Available @code{policy-configuration} fields are:
18574 @deftypevr {@code{policy-configuration} parameter} string name
18575 Name of the policy.
18578 @deftypevr {@code{policy-configuration} parameter} string job-private-access
18579 Specifies an access list for a job's private values. @code{@@ACL} maps
18580 to the printer's requesting-user-name-allowed or
18581 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
18582 owner. @code{@@SYSTEM} maps to the groups listed for the
18583 @code{system-group} field of the @code{files-config} configuration,
18584 which is reified into the @code{cups-files.conf(5)} file. Other
18585 possible elements of the access list include specific user names, and
18586 @code{@@@var{group}} to indicate members of a specific group. The
18587 access list may also be simply @code{all} or @code{default}.
18589 Defaults to @samp{"@@OWNER @@SYSTEM"}.
18592 @deftypevr {@code{policy-configuration} parameter} string job-private-values
18593 Specifies the list of job values to make private, or @code{all},
18594 @code{default}, or @code{none}.
18596 Defaults to @samp{"job-name job-originating-host-name
18597 job-originating-user-name phone"}.
18600 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
18601 Specifies an access list for a subscription's private values.
18602 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
18603 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
18604 owner. @code{@@SYSTEM} maps to the groups listed for the
18605 @code{system-group} field of the @code{files-config} configuration,
18606 which is reified into the @code{cups-files.conf(5)} file. Other
18607 possible elements of the access list include specific user names, and
18608 @code{@@@var{group}} to indicate members of a specific group. The
18609 access list may also be simply @code{all} or @code{default}.
18611 Defaults to @samp{"@@OWNER @@SYSTEM"}.
18614 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
18615 Specifies the list of job values to make private, or @code{all},
18616 @code{default}, or @code{none}.
18618 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
18619 notify-subscriber-user-name notify-user-data"}.
18622 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
18623 Access control by IPP operation.
18625 Defaults to @samp{()}.
18629 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
18630 Specifies whether job files (documents) are preserved after a job is
18631 printed. If a numeric value is specified, job files are preserved for
18632 the indicated number of seconds after printing. Otherwise a boolean
18633 value applies indefinitely.
18635 Defaults to @samp{86400}.
18638 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
18639 Specifies whether the job history is preserved after a job is printed.
18640 If a numeric value is specified, the job history is preserved for the
18641 indicated number of seconds after printing. If @code{#t}, the job
18642 history is preserved until the MaxJobs limit is reached.
18644 Defaults to @samp{#t}.
18647 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
18648 Specifies the amount of time to wait for job completion before
18649 restarting the scheduler.
18651 Defaults to @samp{30}.
18654 @deftypevr {@code{cups-configuration} parameter} string rip-cache
18655 Specifies the maximum amount of memory to use when converting documents
18656 into bitmaps for a printer.
18658 Defaults to @samp{"128m"}.
18661 @deftypevr {@code{cups-configuration} parameter} string server-admin
18662 Specifies the email address of the server administrator.
18664 Defaults to @samp{"root@@localhost.localdomain"}.
18667 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
18668 The ServerAlias directive is used for HTTP Host header validation when
18669 clients connect to the scheduler from external interfaces. Using the
18670 special name @code{*} can expose your system to known browser-based DNS
18671 rebinding attacks, even when accessing sites through a firewall. If the
18672 auto-discovery of alternate names does not work, we recommend listing
18673 each alternate name with a ServerAlias directive instead of using
18676 Defaults to @samp{*}.
18679 @deftypevr {@code{cups-configuration} parameter} string server-name
18680 Specifies the fully-qualified host name of the server.
18682 Defaults to @samp{"localhost"}.
18685 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
18686 Specifies what information is included in the Server header of HTTP
18687 responses. @code{None} disables the Server header. @code{ProductOnly}
18688 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
18689 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
18690 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
18691 the output of the @code{uname} command. @code{Full} reports @code{CUPS
18692 2.0.0 (@var{uname}) IPP/2.0}.
18694 Defaults to @samp{Minimal}.
18697 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
18698 Listens on the specified interfaces for encrypted connections. Valid
18699 values are of the form @var{address}:@var{port}, where @var{address} is
18700 either an IPv6 address enclosed in brackets, an IPv4 address, or
18701 @code{*} to indicate all addresses.
18703 Defaults to @samp{()}.
18706 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
18707 Sets encryption options. By default, CUPS only supports encryption
18708 using TLS v1.0 or higher using known secure cipher suites. Security is
18709 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
18710 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
18711 suites, which are required for some older clients. The @code{AllowSSL3} option
18712 enables SSL v3.0, which is required for some older clients that do not support
18713 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
18714 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
18715 protocol version to TLS v1.1.
18717 Defaults to @samp{()}.
18720 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
18721 Specifies whether the scheduler requires clients to strictly adhere to
18722 the IPP specifications.
18724 Defaults to @samp{#f}.
18727 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
18728 Specifies the HTTP request timeout, in seconds.
18730 Defaults to @samp{300}.
18734 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
18735 Specifies whether the web interface is enabled.
18737 Defaults to @samp{#f}.
18740 At this point you're probably thinking ``oh dear, Guix manual, I like
18741 you but you can stop already with the configuration options''. Indeed.
18742 However, one more point: it could be that you have an existing
18743 @code{cupsd.conf} that you want to use. In that case, you can pass an
18744 @code{opaque-cups-configuration} as the configuration of a
18745 @code{cups-service-type}.
18747 Available @code{opaque-cups-configuration} fields are:
18749 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
18753 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
18754 The contents of the @code{cupsd.conf}, as a string.
18757 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
18758 The contents of the @code{cups-files.conf} file, as a string.
18761 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
18762 strings of the same name, you could instantiate a CUPS service like
18766 (service cups-service-type
18767 (opaque-cups-configuration
18768 (cupsd.conf cupsd.conf)
18769 (cups-files.conf cups-files.conf)))
18773 @node Desktop Services
18774 @subsection Desktop Services
18776 The @code{(gnu services desktop)} module provides services that are
18777 usually useful in the context of a ``desktop'' setup---that is, on a
18778 machine running a graphical display server, possibly with graphical user
18779 interfaces, etc. It also defines services that provide specific desktop
18780 environments like GNOME, Xfce or MATE.
18782 To simplify things, the module defines a variable containing the set of
18783 services that users typically expect on a machine with a graphical
18784 environment and networking:
18786 @defvr {Scheme Variable} %desktop-services
18787 This is a list of services that builds upon @code{%base-services} and
18788 adds or adjusts services for a typical ``desktop'' setup.
18790 In particular, it adds a graphical login manager (@pxref{X Window,
18791 @code{gdm-service-type}}), screen lockers, a network management tool
18792 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
18793 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
18794 energy and color management services, the @code{elogind} login and seat
18795 manager, the Polkit privilege service, the GeoClue location service, the
18796 AccountsService daemon that allows authorized users change system passwords,
18797 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
18798 name service switch service configured to be able to use @code{nss-mdns}
18799 (@pxref{Name Service Switch, mDNS}).
18802 The @code{%desktop-services} variable can be used as the @code{services}
18803 field of an @code{operating-system} declaration (@pxref{operating-system
18804 Reference, @code{services}}).
18806 Additionally, the @code{gnome-desktop-service-type},
18807 @code{xfce-desktop-service}, @code{mate-desktop-service-type},
18808 @code{lxqt-desktop-service-type} and @code{enlightenment-desktop-service-type}
18809 procedures can add GNOME, Xfce, MATE and/or Enlightenment to a system. To
18810 ``add GNOME'' means that system-level services like the backlight adjustment
18811 helpers and the power management utilities are added to the system, extending
18812 @code{polkit} and @code{dbus} appropriately, allowing GNOME to operate with
18813 elevated privileges on a limited number of special-purpose system interfaces.
18814 Additionally, adding a service made by @code{gnome-desktop-service-type} adds
18815 the GNOME metapackage to the system profile. Likewise, adding the Xfce
18816 service not only adds the @code{xfce} metapackage to the system profile, but
18817 it also gives the Thunar file manager the ability to open a ``root-mode'' file
18818 management window, if the user authenticates using the administrator's
18819 password via the standard polkit graphical interface. To ``add MATE'' means
18820 that @code{polkit} and @code{dbus} are extended appropriately, allowing MATE
18821 to operate with elevated privileges on a limited number of special-purpose
18822 system interfaces. Additionally, adding a service of type
18823 @code{mate-desktop-service-type} adds the MATE metapackage to the system
18824 profile. ``Adding Enlightenment'' means that @code{dbus} is extended
18825 appropriately, and several of Enlightenment's binaries are set as setuid,
18826 allowing Enlightenment's screen locker and other functionality to work as
18829 The desktop environments in Guix use the Xorg display server by
18830 default. If you'd like to use the newer display server protocol
18831 called Wayland, you need to use the @code{sddm-service} instead of
18832 GDM as the graphical login manager. You should then
18833 select the ``GNOME (Wayland)'' session in SDDM@. Alternatively you can
18834 also try starting GNOME on Wayland manually from a TTY with the
18835 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
18836 gnome-session``. Currently only GNOME has support for Wayland.
18838 @defvr {Scheme Variable} gnome-desktop-service-type
18839 This is the type of the service that adds the @uref{https://www.gnome.org,
18840 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
18841 object (see below).
18843 This service adds the @code{gnome} package to the system profile, and extends
18844 polkit with the actions from @code{gnome-settings-daemon}.
18847 @deftp {Data Type} gnome-desktop-configuration
18848 Configuration record for the GNOME desktop environment.
18851 @item @code{gnome} (default: @code{gnome})
18852 The GNOME package to use.
18856 @defvr {Scheme Variable} xfce-desktop-service-type
18857 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
18858 desktop environment. Its value is an @code{xfce-desktop-configuration} object
18861 This service adds the @code{xfce} package to the system profile, and
18862 extends polkit with the ability for @code{thunar} to manipulate the file
18863 system as root from within a user session, after the user has authenticated
18864 with the administrator's password.
18866 Note that @code{xfce4-panel} and its plugin packages should be installed in
18867 the same profile to ensure compatibility. When using this service, you should
18868 add extra plugins (@code{xfce4-whiskermenu-plugin},
18869 @code{xfce4-weather-plugin}, etc.) to the @code{packages} field of your
18870 @code{operating-system}.
18873 @deftp {Data Type} xfce-desktop-configuration
18874 Configuration record for the Xfce desktop environment.
18877 @item @code{xfce} (default: @code{xfce})
18878 The Xfce package to use.
18882 @deffn {Scheme Variable} mate-desktop-service-type
18883 This is the type of the service that runs the @uref{https://mate-desktop.org/,
18884 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
18885 object (see below).
18887 This service adds the @code{mate} package to the system
18888 profile, and extends polkit with the actions from
18889 @code{mate-settings-daemon}.
18892 @deftp {Data Type} mate-desktop-configuration
18893 Configuration record for the MATE desktop environment.
18896 @item @code{mate} (default: @code{mate})
18897 The MATE package to use.
18901 @deffn {Scheme Variable} lxqt-desktop-service-type
18902 This is the type of the service that runs the @uref{https://lxqt.github.io,
18903 LXQt desktop environment}. Its value is a @code{lxqt-desktop-configuration}
18904 object (see below).
18906 This service adds the @code{lxqt} package to the system
18910 @deftp {Data Type} lxqt-desktop-configuration
18911 Configuration record for the LXQt desktop environment.
18914 @item @code{lxqt} (default: @code{lxqt})
18915 The LXQT package to use.
18919 @deffn {Scheme Variable} enlightenment-desktop-service-type
18920 Return a service that adds the @code{enlightenment} package to the system
18921 profile, and extends dbus with actions from @code{efl}.
18924 @deftp {Data Type} enlightenment-desktop-service-configuration
18926 @item @code{enlightenment} (default: @code{enlightenment})
18927 The enlightenment package to use.
18931 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
18932 the default @code{%desktop-services} variable doesn't include any of
18933 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
18934 @code{%desktop-services} in the @code{services} field of your
18935 @code{operating-system}:
18938 (use-modules (gnu))
18939 (use-service-modules desktop)
18942 ;; cons* adds items to the list given as its last argument.
18943 (services (cons* (service gnome-desktop-service-type)
18944 (service xfce-desktop-service)
18945 %desktop-services))
18949 These desktop environments will then be available as options in the
18950 graphical login window.
18952 The actual service definitions included in @code{%desktop-services} and
18953 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
18954 are described below.
18956 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
18957 Return a service that runs the ``system bus'', using @var{dbus}, with
18958 support for @var{services}.
18960 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
18961 facility. Its system bus is used to allow system services to communicate
18962 and to be notified of system-wide events.
18964 @var{services} must be a list of packages that provide an
18965 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
18966 and policy files. For example, to allow avahi-daemon to use the system bus,
18967 @var{services} must be equal to @code{(list avahi)}.
18970 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
18971 Return a service that runs the @code{elogind} login and
18972 seat management daemon. @uref{https://github.com/elogind/elogind,
18973 Elogind} exposes a D-Bus interface that can be used to know which users
18974 are logged in, know what kind of sessions they have open, suspend the
18975 system, inhibit system suspend, reboot the system, and other tasks.
18977 Elogind handles most system-level power events for a computer, for
18978 example suspending the system when a lid is closed, or shutting it down
18979 when the power button is pressed.
18981 The @var{config} keyword argument specifies the configuration for
18982 elogind, and should be the result of an @code{(elogind-configuration
18983 (@var{parameter} @var{value})...)} invocation. Available parameters and
18984 their default values are:
18987 @item kill-user-processes?
18989 @item kill-only-users
18991 @item kill-exclude-users
18993 @item inhibit-delay-max-seconds
18995 @item handle-power-key
18997 @item handle-suspend-key
18999 @item handle-hibernate-key
19001 @item handle-lid-switch
19003 @item handle-lid-switch-docked
19005 @item handle-lid-switch-external-power
19007 @item power-key-ignore-inhibited?
19009 @item suspend-key-ignore-inhibited?
19011 @item hibernate-key-ignore-inhibited?
19013 @item lid-switch-ignore-inhibited?
19015 @item holdoff-timeout-seconds
19019 @item idle-action-seconds
19021 @item runtime-directory-size-percent
19023 @item runtime-directory-size
19027 @item suspend-state
19028 @code{("mem" "standby" "freeze")}
19031 @item hibernate-state
19033 @item hibernate-mode
19034 @code{("platform" "shutdown")}
19035 @item hybrid-sleep-state
19037 @item hybrid-sleep-mode
19038 @code{("suspend" "platform" "shutdown")}
19042 @deffn {Scheme Procedure} accountsservice-service @
19043 [#:accountsservice @var{accountsservice}]
19044 Return a service that runs AccountsService, a system service that can
19045 list available accounts, change their passwords, and so on.
19046 AccountsService integrates with PolicyKit to enable unprivileged users
19047 to acquire the capability to modify their system configuration.
19048 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
19049 accountsservice web site} for more information.
19051 The @var{accountsservice} keyword argument is the @code{accountsservice}
19052 package to expose as a service.
19055 @deffn {Scheme Procedure} polkit-service @
19056 [#:polkit @var{polkit}]
19057 Return a service that runs the
19058 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
19059 management service}, which allows system administrators to grant access to
19060 privileged operations in a structured way. By querying the Polkit service, a
19061 privileged system component can know when it should grant additional
19062 capabilities to ordinary users. For example, an ordinary user can be granted
19063 the capability to suspend the system if the user is logged in locally.
19066 @defvr {Scheme Variable} polkit-wheel-service
19067 Service that adds the @code{wheel} group as admins to the Polkit
19068 service. This makes it so that users in the @code{wheel} group are queried
19069 for their own passwords when performing administrative actions instead of
19070 @code{root}'s, similar to the behaviour used by @code{sudo}.
19073 @defvr {Scheme Variable} upower-service-type
19074 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
19075 system-wide monitor for power consumption and battery levels, with the given
19076 configuration settings.
19078 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
19079 notably used by GNOME.
19082 @deftp {Data Type} upower-configuration
19083 Data type representation the configuration for UPower.
19087 @item @code{upower} (default: @var{upower})
19088 Package to use for @code{upower}.
19090 @item @code{watts-up-pro?} (default: @code{#f})
19091 Enable the Watts Up Pro device.
19093 @item @code{poll-batteries?} (default: @code{#t})
19094 Enable polling the kernel for battery level changes.
19096 @item @code{ignore-lid?} (default: @code{#f})
19097 Ignore the lid state, this can be useful if it's incorrect on a device.
19099 @item @code{use-percentage-for-policy?} (default: @code{#f})
19100 Whether battery percentage based policy should be used. The default is to use
19101 the time left, change to @code{#t} to use the percentage.
19103 @item @code{percentage-low} (default: @code{10})
19104 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
19105 at which the battery is considered low.
19107 @item @code{percentage-critical} (default: @code{3})
19108 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
19109 at which the battery is considered critical.
19111 @item @code{percentage-action} (default: @code{2})
19112 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
19113 at which action will be taken.
19115 @item @code{time-low} (default: @code{1200})
19116 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
19117 seconds at which the battery is considered low.
19119 @item @code{time-critical} (default: @code{300})
19120 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
19121 seconds at which the battery is considered critical.
19123 @item @code{time-action} (default: @code{120})
19124 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
19125 seconds at which action will be taken.
19127 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
19128 The action taken when @code{percentage-action} or @code{time-action} is
19129 reached (depending on the configuration of @code{use-percentage-for-policy?}).
19131 Possible values are:
19141 @code{'hybrid-sleep}.
19147 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
19148 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
19149 UDisks}, a @dfn{disk management} daemon that provides user interfaces
19150 with notifications and ways to mount/unmount disks. Programs that talk
19151 to UDisks include the @command{udisksctl} command, part of UDisks, and
19152 GNOME Disks. Note that Udisks relies on the @command{mount} command, so
19153 it will only be able to use the file-system utilities installed in the
19154 system profile. For example if you want to be able to mount NTFS
19155 file-systems in read and write fashion, you'll need to have
19156 @code{ntfs-3g} installed system-wide.
19159 @deffn {Scheme Variable} colord-service-type
19160 This is the type of the service that runs @command{colord}, a system
19161 service with a D-Bus
19162 interface to manage the color profiles of input and output devices such as
19163 screens and scanners. It is notably used by the GNOME Color Manager graphical
19164 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
19165 site} for more information.
19168 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
19169 Return a configuration allowing an application to access GeoClue
19170 location data. @var{name} is the Desktop ID of the application, without
19171 the @code{.desktop} part. If @var{allowed?} is true, the application
19172 will have access to location information by default. The boolean
19173 @var{system?} value indicates whether an application is a system component
19174 or not. Finally @var{users} is a list of UIDs of all users for which
19175 this application is allowed location info access. An empty users list
19176 means that all users are allowed.
19179 @cindex scanner access
19180 @deffn {Scheme Procedure} sane-service-type
19181 This service provides access to scanners @i{via}
19182 @uref{http://www.sane-project.org, SANE} by installing the necessary udev
19186 @defvr {Scheme Variable} %standard-geoclue-applications
19187 The standard list of well-known GeoClue application configurations,
19188 granting authority to the GNOME date-and-time utility to ask for the
19189 current location in order to set the time zone, and allowing the
19190 IceCat and Epiphany web browsers to request location information.
19191 IceCat and Epiphany both query the user before allowing a web page to
19192 know the user's location.
19195 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
19196 [#:whitelist '()] @
19197 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
19198 [#:submit-data? #f]
19199 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
19200 [#:submission-nick "geoclue"] @
19201 [#:applications %standard-geoclue-applications]
19202 Return a service that runs the GeoClue location service. This service
19203 provides a D-Bus interface to allow applications to request access to a
19204 user's physical location, and optionally to add information to online
19205 location databases. See
19206 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
19207 web site} for more information.
19210 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
19211 [@w{#:auto-enable? #f}]
19212 Return a service that runs the @command{bluetoothd} daemon, which
19213 manages all the Bluetooth devices and provides a number of D-Bus
19214 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
19215 powered automatically at boot, which can be useful when using a
19216 bluetooth keyboard or mouse.
19218 Users need to be in the @code{lp} group to access the D-Bus service.
19221 @defvr {Scheme Variable} gnome-keyring-service-type
19222 This is the type of the service that adds the
19223 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
19224 value is a @code{gnome-keyring-configuration} object (see below).
19226 This service adds the @code{gnome-keyring} package to the system profile
19227 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
19228 a user's login keyring when they log in or setting its password with passwd.
19231 @deftp {Data Type} gnome-keyring-configuration
19232 Configuration record for the GNOME Keyring service.
19235 @item @code{keyring} (default: @code{gnome-keyring})
19236 The GNOME keyring package to use.
19238 @item @code{pam-services}
19239 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
19240 services to extend, where @var{service} is the name of an existing
19241 service to extend and @var{kind} is one of @code{login} or
19244 If @code{login} is given, it adds an optional
19245 @code{pam_gnome_keyring.so} to the auth block without arguments and to
19246 the session block with @code{auto_start}. If @code{passwd} is given, it
19247 adds an optional @code{pam_gnome_keyring.so} to the password block
19250 By default, this field contains ``gdm-password'' with the value @code{login}
19251 and ``passwd'' is with the value @code{passwd}.
19256 @node Sound Services
19257 @subsection Sound Services
19259 @cindex sound support
19261 @cindex PulseAudio, sound support
19263 The @code{(gnu services sound)} module provides a service to configure the
19264 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
19265 preferred ALSA output driver.
19267 @deffn {Scheme Variable} alsa-service-type
19268 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
19269 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
19270 configuration file. The value for this type is a @command{alsa-configuration}
19271 record as in this example:
19274 (service alsa-service-type)
19277 See below for details about @code{alsa-configuration}.
19280 @deftp {Data Type} alsa-configuration
19281 Data type representing the configuration for @code{alsa-service}.
19284 @item @code{alsa-plugins} (default: @var{alsa-plugins})
19285 @code{alsa-plugins} package to use.
19287 @item @code{pulseaudio?} (default: @var{#t})
19288 Whether ALSA applications should transparently be made to use the
19289 @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
19291 Using PulseAudio allows you to run several sound-producing applications
19292 at the same time and to individual control them @i{via}
19293 @command{pavucontrol}, among other things.
19295 @item @code{extra-options} (default: @var{""})
19296 String to append to the @file{/etc/asound.conf} file.
19301 Individual users who want to override the system configuration of ALSA can do
19302 it with the @file{~/.asoundrc} file:
19305 # In guix, we have to specify the absolute path for plugins.
19307 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
19310 # Routing ALSA to jack:
19311 # <http://jackaudio.org/faq/routing_alsa.html>.
19315 0 system:playback_1
19316 1 system:playback_2
19333 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
19336 @deffn {Scheme Variable} pulseaudio-service-type
19337 This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
19338 sound server. It exists to allow system overrides of the default settings
19339 via @code{pulseaudio-configuration}, see below.
19342 This service overrides per-user configuration files. If you want
19343 PulseAudio to honor configuration files in @file{~/.config/pulse} you
19344 have to unset the environment variables @env{PULSE_CONFIG} and
19345 @env{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
19349 This service on its own does not ensure, that the @code{pulseaudio} package
19350 exists on your machine. It merely adds configuration files for it, as
19351 detailed below. In the (admittedly unlikely) case, that you find yourself
19352 without a @code{pulseaudio} package, consider enabling it through the
19353 @code{alsa-service-type} above.
19357 @deftp {Data Type} pulseaudio-configuration
19358 Data type representing the configuration for @code{pulseaudio-service}.
19361 @item @code{client-conf} (default: @code{'()})
19362 List of settings to set in @file{client.conf}.
19363 Accepts a list of strings or a symbol-value pairs. A string will be
19364 inserted as-is with a newline added. A pair will be formatted as
19365 ``key = value'', again with a newline added.
19367 @item @code{daemon-conf} (default: @code{'((flat-volumes . no))})
19368 List of settings to set in @file{daemon.conf}, formatted just like
19371 @item @code{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
19372 Script file to use as @file{default.pa}.
19374 @item @code{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
19375 Script file to use as @file{system.pa}.
19379 @deffn {Scheme Variable} ladspa-service-type
19380 This service sets the @var{LADSPA_PATH} variable, so that programs, which
19381 respect it, e.g. PulseAudio, can load LADSPA plugins.
19383 The following example will setup the service to enable modules from the
19384 @code{swh-plugins} package:
19387 (service ladspa-service-type
19388 (ladspa-configuration (plugins (list swh-plugins))))
19391 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
19396 @node Database Services
19397 @subsection Database Services
19401 The @code{(gnu services databases)} module provides the following services.
19403 @subsubheading PostgreSQL
19405 The following example describes a PostgreSQL service with the default
19409 (service postgresql-service-type
19410 (postgresql-configuration
19411 (postgresql postgresql-10)))
19414 If the services fails to start, it may be due to an incompatible
19415 cluster already present in @var{data-directory}. Adjust it (or, if you
19416 don't need the cluster anymore, delete @var{data-directory}), then
19417 restart the service.
19419 Peer authentication is used by default and the @code{postgres} user
19420 account has no shell, which prevents the direct execution of @code{psql}
19421 commands as this user. To use @code{psql}, you can temporarily log in
19422 as @code{postgres} using a shell, create a PostgreSQL superuser with the
19423 same name as one of the system users and then create the associated
19427 sudo -u postgres -s /bin/sh
19428 createuser --interactive
19429 createdb $MY_USER_LOGIN # Replace appropriately.
19432 @deftp {Data Type} postgresql-configuration
19433 Data type representing the configuration for the
19434 @code{postgresql-service-type}.
19437 @item @code{postgresql}
19438 PostgreSQL package to use for the service.
19440 @item @code{port} (default: @code{5432})
19441 Port on which PostgreSQL should listen.
19443 @item @code{locale} (default: @code{"en_US.utf8"})
19444 Locale to use as the default when creating the database cluster.
19446 @item @code{config-file} (default: @code{(postgresql-config-file)})
19447 The configuration file to use when running PostgreSQL@. The default
19448 behaviour uses the postgresql-config-file record with the default values
19451 @item @code{log-directory} (default: @code{"/var/log/postgresql"})
19452 The directory where @command{pg_ctl} output will be written in a file
19453 named @code{"pg_ctl.log"}. This file can be useful to debug PostgreSQL
19454 configuration errors for instance.
19456 @item @code{data-directory} (default: @code{"/var/lib/postgresql/data"})
19457 Directory in which to store the data.
19459 @item @code{extension-packages} (default: @code{'()})
19460 @cindex postgresql extension-packages
19461 Additional extensions are loaded from packages listed in
19462 @var{extension-packages}. Extensions are available at runtime. For instance,
19463 to create a geographic database using the @code{postgis} extension, a user can
19464 configure the postgresql-service as in this example:
19468 (use-package-modules databases geo)
19472 ;; postgresql is required to run `psql' but postgis is not required for
19473 ;; proper operation.
19474 (packages (cons* postgresql %base-packages))
19477 (service postgresql-service-type
19478 (postgresql-configuration
19479 (postgresql postgresql-10)
19480 (extension-packages (list postgis))))
19484 Then the extension becomes visible and you can initialise an empty geographic
19485 database in this way:
19489 > create database postgistest;
19490 > \connect postgistest;
19491 > create extension postgis;
19492 > create extension postgis_topology;
19495 There is no need to add this field for contrib extensions such as hstore or
19496 dblink as they are already loadable by postgresql. This field is only
19497 required to add extensions provided by other packages.
19502 @deftp {Data Type} postgresql-config-file
19503 Data type representing the PostgreSQL configuration file. As shown in
19504 the following example, this can be used to customize the configuration
19505 of PostgreSQL@. Note that you can use any G-expression or filename in
19506 place of this record, if you already have a configuration file you'd
19507 like to use for example.
19510 (service postgresql-service-type
19511 (postgresql-configuration
19513 (postgresql-config-file
19514 (log-destination "stderr")
19516 (plain-file "pg_hba.conf"
19518 local all all trust
19519 host all all 127.0.0.1/32 md5
19520 host all all ::1/128 md5"))
19522 '(("session_preload_libraries" "auto_explain")
19523 ("random_page_cost" 2)
19524 ("auto_explain.log_min_duration" "100 ms")
19525 ("work_mem" "500 MB")
19526 ("logging_collector" #t)
19527 ("log_directory" "/var/log/postgresql")))))))
19531 @item @code{log-destination} (default: @code{"syslog"})
19532 The logging method to use for PostgreSQL@. Multiple values are accepted,
19533 separated by commas.
19535 @item @code{hba-file} (default: @code{%default-postgres-hba})
19536 Filename or G-expression for the host-based authentication
19539 @item @code{ident-file} (default: @code{%default-postgres-ident})
19540 Filename or G-expression for the user name mapping configuration.
19542 @item @code{socket-directory} (default: @code{"/var/run/postgresql"})
19543 Specifies the directory of the Unix-domain socket(s) on which PostgreSQL
19544 is to listen for connections from client applications. If set to
19545 @code{#false} PostgreSQL does not listen on any Unix-domain sockets, in
19546 which case only TCP/IP sockets can be used to connect to the server.
19548 @item @code{extra-config} (default: @code{'()})
19549 List of additional keys and values to include in the PostgreSQL config
19550 file. Each entry in the list should be a list where the first element
19551 is the key, and the remaining elements are the values.
19553 The values can be numbers, booleans or strings and will be mapped to
19554 PostgreSQL parameters types @code{Boolean}, @code{String},
19555 @code{Numeric}, @code{Numeric with Unit} and @code{Enumerated} described
19556 @uref{https://www.postgresql.org/docs/current/config-setting.html,
19562 @deffn {Scheme Variable} postgresql-role-service-type
19563 This service allows to create PostgreSQL roles and databases after
19564 PostgreSQL service start. Here is an example of its use.
19567 (service postgresql-role-service-type
19568 (postgresql-role-configuration
19570 (list (postgresql-role
19572 (create-database? #t))))))
19575 This service can be extended with extra roles, as in this
19579 (service-extension postgresql-role-service-type
19580 (const (postgresql-role
19582 (create-database? #t))))
19586 @deftp {Data Type} postgresql-role
19587 PostgreSQL manages database access permissions using the concept of
19588 roles. A role can be thought of as either a database user, or a group
19589 of database users, depending on how the role is set up. Roles can own
19590 database objects (for example, tables) and can assign privileges on
19591 those objects to other roles to control who has access to which objects.
19597 @item @code{permissions} (default: @code{'(createdb login)})
19598 The role permissions list. Supported permissions are @code{bypassrls},
19599 @code{createdb}, @code{createrole}, @code{login}, @code{replication} and
19602 @item @code{create-database?} (default: @code{#f})
19603 Whether to create a database with the same name as the role.
19608 @deftp {Data Type} postgresql-role-configuration
19609 Data type representing the configuration of
19610 @var{postgresql-role-service-type}.
19613 @item @code{host} (default: @code{"/var/run/postgresql"})
19614 The PostgreSQL host to connect to.
19616 @item @code{log} (default: @code{"/var/log/postgresql_roles.log"})
19617 File name of the log file.
19619 @item @code{roles} (default: @code{'()})
19620 The initial PostgreSQL roles to create.
19624 @subsubheading MariaDB/MySQL
19626 @defvr {Scheme Variable} mysql-service-type
19627 This is the service type for a MySQL or MariaDB database server. Its value
19628 is a @code{mysql-configuration} object that specifies which package to use,
19629 as well as various settings for the @command{mysqld} daemon.
19632 @deftp {Data Type} mysql-configuration
19633 Data type representing the configuration of @var{mysql-service-type}.
19636 @item @code{mysql} (default: @var{mariadb})
19637 Package object of the MySQL database server, can be either @var{mariadb}
19640 For MySQL, a temporary root password will be displayed at activation time.
19641 For MariaDB, the root password is empty.
19643 @item @code{bind-address} (default: @code{"127.0.0.1"})
19644 The IP on which to listen for network connections. Use @code{"0.0.0.0"}
19645 to bind to all available network interfaces.
19647 @item @code{port} (default: @code{3306})
19648 TCP port on which the database server listens for incoming connections.
19650 @item @code{socket} (default: @code{"/run/mysqld/mysqld.sock"})
19651 Socket file to use for local (non-network) connections.
19653 @item @code{extra-content} (default: @code{""})
19654 Additional settings for the @file{my.cnf} configuration file.
19656 @item @code{auto-upgrade?} (default: @code{#t})
19657 Whether to automatically run @command{mysql_upgrade} after starting the
19658 service. This is necessary to upgrade the @dfn{system schema} after
19659 ``major'' updates (such as switching from MariaDB 10.4 to 10.5), but can
19660 be disabled if you would rather do that manually.
19665 @subsubheading Memcached
19667 @defvr {Scheme Variable} memcached-service-type
19668 This is the service type for the @uref{https://memcached.org/,
19669 Memcached} service, which provides a distributed in memory cache. The
19670 value for the service type is a @code{memcached-configuration} object.
19674 (service memcached-service-type)
19677 @deftp {Data Type} memcached-configuration
19678 Data type representing the configuration of memcached.
19681 @item @code{memcached} (default: @code{memcached})
19682 The Memcached package to use.
19684 @item @code{interfaces} (default: @code{'("0.0.0.0")})
19685 Network interfaces on which to listen.
19687 @item @code{tcp-port} (default: @code{11211})
19688 Port on which to accept connections.
19690 @item @code{udp-port} (default: @code{11211})
19691 Port on which to accept UDP connections on, a value of 0 will disable
19692 listening on a UDP socket.
19694 @item @code{additional-options} (default: @code{'()})
19695 Additional command line options to pass to @code{memcached}.
19699 @subsubheading MongoDB
19701 @defvr {Scheme Variable} mongodb-service-type
19702 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
19703 The value for the service type is a @code{mongodb-configuration} object.
19707 (service mongodb-service-type)
19710 @deftp {Data Type} mongodb-configuration
19711 Data type representing the configuration of mongodb.
19714 @item @code{mongodb} (default: @code{mongodb})
19715 The MongoDB package to use.
19717 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
19718 The configuration file for MongoDB.
19720 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
19721 This value is used to create the directory, so that it exists and is
19722 owned by the mongodb user. It should match the data-directory which
19723 MongoDB is configured to use through the configuration file.
19727 @subsubheading Redis
19729 @defvr {Scheme Variable} redis-service-type
19730 This is the service type for the @uref{https://redis.io/, Redis}
19731 key/value store, whose value is a @code{redis-configuration} object.
19734 @deftp {Data Type} redis-configuration
19735 Data type representing the configuration of redis.
19738 @item @code{redis} (default: @code{redis})
19739 The Redis package to use.
19741 @item @code{bind} (default: @code{"127.0.0.1"})
19742 Network interface on which to listen.
19744 @item @code{port} (default: @code{6379})
19745 Port on which to accept connections on, a value of 0 will disable
19746 listening on a TCP socket.
19748 @item @code{working-directory} (default: @code{"/var/lib/redis"})
19749 Directory in which to store the database and related files.
19753 @node Mail Services
19754 @subsection Mail Services
19758 The @code{(gnu services mail)} module provides Guix service definitions
19759 for email services: IMAP, POP3, and LMTP servers, as well as mail
19760 transport agents (MTAs). Lots of acronyms! These services are detailed
19761 in the subsections below.
19763 @subsubheading Dovecot Service
19765 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
19766 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
19769 By default, Dovecot does not need much configuration; the default
19770 configuration object created by @code{(dovecot-configuration)} will
19771 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
19772 certificate will be generated for TLS-protected connections, though
19773 Dovecot will also listen on cleartext ports by default. There are a
19774 number of options, though, which mail administrators might need to change,
19775 and as is the case with other services, Guix allows the system
19776 administrator to specify these parameters via a uniform Scheme interface.
19778 For example, to specify that mail is located at @code{maildir~/.mail},
19779 one would instantiate the Dovecot service like this:
19782 (dovecot-service #:config
19783 (dovecot-configuration
19784 (mail-location "maildir:~/.mail")))
19787 The available configuration parameters follow. Each parameter
19788 definition is preceded by its type; for example, @samp{string-list foo}
19789 indicates that the @code{foo} parameter should be specified as a list of
19790 strings. There is also a way to specify the configuration as a string,
19791 if you have an old @code{dovecot.conf} file that you want to port over
19792 from some other system; see the end for more details.
19794 @c The following documentation was initially generated by
19795 @c (generate-documentation) in (gnu services mail). Manually maintained
19796 @c documentation is better, so we shouldn't hesitate to edit below as
19797 @c needed. However if the change you want to make to this documentation
19798 @c can be done in an automated way, it's probably easier to change
19799 @c (generate-documentation) than to make it below and have to deal with
19800 @c the churn as dovecot updates.
19802 Available @code{dovecot-configuration} fields are:
19804 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
19805 The dovecot package.
19808 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
19809 A list of IPs or hosts where to listen for connections. @samp{*}
19810 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
19811 interfaces. If you want to specify non-default ports or anything more
19812 complex, customize the address and port fields of the
19813 @samp{inet-listener} of the specific services you are interested in.
19816 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
19817 List of protocols we want to serve. Available protocols include
19818 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
19820 Available @code{protocol-configuration} fields are:
19822 @deftypevr {@code{protocol-configuration} parameter} string name
19823 The name of the protocol.
19826 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
19827 UNIX socket path to the master authentication server to find users.
19828 This is used by imap (for shared users) and lda.
19829 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
19832 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
19833 Space separated list of plugins to load.
19836 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
19837 Maximum number of IMAP connections allowed for a user from each IP
19838 address. NOTE: The username is compared case-sensitively.
19839 Defaults to @samp{10}.
19844 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
19845 List of services to enable. Available services include @samp{imap},
19846 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
19849 Available @code{service-configuration} fields are:
19851 @deftypevr {@code{service-configuration} parameter} string kind
19852 The service kind. Valid values include @code{director},
19853 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
19854 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
19855 @code{tcpwrap}, @code{quota-warning}, or anything else.
19858 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
19859 Listeners for the service. A listener is either a
19860 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
19861 an @code{inet-listener-configuration}.
19862 Defaults to @samp{()}.
19864 Available @code{unix-listener-configuration} fields are:
19866 @deftypevr {@code{unix-listener-configuration} parameter} string path
19867 Path to the file, relative to @code{base-dir} field. This is also used as
19871 @deftypevr {@code{unix-listener-configuration} parameter} string mode
19872 The access mode for the socket.
19873 Defaults to @samp{"0600"}.
19876 @deftypevr {@code{unix-listener-configuration} parameter} string user
19877 The user to own the socket.
19878 Defaults to @samp{""}.
19881 @deftypevr {@code{unix-listener-configuration} parameter} string group
19882 The group to own the socket.
19883 Defaults to @samp{""}.
19887 Available @code{fifo-listener-configuration} fields are:
19889 @deftypevr {@code{fifo-listener-configuration} parameter} string path
19890 Path to the file, relative to @code{base-dir} field. This is also used as
19894 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
19895 The access mode for the socket.
19896 Defaults to @samp{"0600"}.
19899 @deftypevr {@code{fifo-listener-configuration} parameter} string user
19900 The user to own the socket.
19901 Defaults to @samp{""}.
19904 @deftypevr {@code{fifo-listener-configuration} parameter} string group
19905 The group to own the socket.
19906 Defaults to @samp{""}.
19910 Available @code{inet-listener-configuration} fields are:
19912 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
19913 The protocol to listen for.
19916 @deftypevr {@code{inet-listener-configuration} parameter} string address
19917 The address on which to listen, or empty for all addresses.
19918 Defaults to @samp{""}.
19921 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
19922 The port on which to listen.
19925 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
19926 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
19928 Defaults to @samp{#t}.
19933 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
19934 Maximum number of simultaneous client connections per process. Once
19935 this number of connections is received, the next incoming connection
19936 will prompt Dovecot to spawn another process. If set to 0,
19937 @code{default-client-limit} is used instead.
19939 Defaults to @samp{0}.
19943 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
19944 Number of connections to handle before starting a new process.
19945 Typically the only useful values are 0 (unlimited) or 1. 1 is more
19946 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
19947 Defaults to @samp{1}.
19951 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
19952 Maximum number of processes that can exist for this service. If set to
19953 0, @code{default-process-limit} is used instead.
19955 Defaults to @samp{0}.
19959 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
19960 Number of processes to always keep waiting for more connections.
19961 Defaults to @samp{0}.
19964 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
19965 If you set @samp{service-count 0}, you probably need to grow
19967 Defaults to @samp{256000000}.
19972 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
19973 Dict configuration, as created by the @code{dict-configuration}
19976 Available @code{dict-configuration} fields are:
19978 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
19979 A list of key-value pairs that this dict should hold.
19980 Defaults to @samp{()}.
19985 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
19986 A list of passdb configurations, each one created by the
19987 @code{passdb-configuration} constructor.
19989 Available @code{passdb-configuration} fields are:
19991 @deftypevr {@code{passdb-configuration} parameter} string driver
19992 The driver that the passdb should use. Valid values include
19993 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
19995 Defaults to @samp{"pam"}.
19998 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
19999 Space separated list of arguments to the passdb driver.
20000 Defaults to @samp{""}.
20005 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
20006 List of userdb configurations, each one created by the
20007 @code{userdb-configuration} constructor.
20009 Available @code{userdb-configuration} fields are:
20011 @deftypevr {@code{userdb-configuration} parameter} string driver
20012 The driver that the userdb should use. Valid values include
20013 @samp{passwd} and @samp{static}.
20014 Defaults to @samp{"passwd"}.
20017 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
20018 Space separated list of arguments to the userdb driver.
20019 Defaults to @samp{""}.
20022 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
20023 Override fields from passwd.
20024 Defaults to @samp{()}.
20029 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
20030 Plug-in configuration, created by the @code{plugin-configuration}
20034 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
20035 List of namespaces. Each item in the list is created by the
20036 @code{namespace-configuration} constructor.
20038 Available @code{namespace-configuration} fields are:
20040 @deftypevr {@code{namespace-configuration} parameter} string name
20041 Name for this namespace.
20044 @deftypevr {@code{namespace-configuration} parameter} string type
20045 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
20046 Defaults to @samp{"private"}.
20049 @deftypevr {@code{namespace-configuration} parameter} string separator
20050 Hierarchy separator to use. You should use the same separator for
20051 all namespaces or some clients get confused. @samp{/} is usually a good
20052 one. The default however depends on the underlying mail storage
20054 Defaults to @samp{""}.
20057 @deftypevr {@code{namespace-configuration} parameter} string prefix
20058 Prefix required to access this namespace. This needs to be
20059 different for all namespaces. For example @samp{Public/}.
20060 Defaults to @samp{""}.
20063 @deftypevr {@code{namespace-configuration} parameter} string location
20064 Physical location of the mailbox. This is in the same format as
20065 mail_location, which is also the default for it.
20066 Defaults to @samp{""}.
20069 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
20070 There can be only one INBOX, and this setting defines which
20072 Defaults to @samp{#f}.
20075 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
20076 If namespace is hidden, it's not advertised to clients via NAMESPACE
20077 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
20078 useful when converting from another server with different namespaces
20079 which you want to deprecate but still keep working. For example you can
20080 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
20082 Defaults to @samp{#f}.
20085 @deftypevr {@code{namespace-configuration} parameter} boolean list?
20086 Show the mailboxes under this namespace with the LIST command. This
20087 makes the namespace visible for clients that do not support the NAMESPACE
20088 extension. The special @code{children} value lists child mailboxes, but
20089 hides the namespace prefix.
20090 Defaults to @samp{#t}.
20093 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
20094 Namespace handles its own subscriptions. If set to @code{#f}, the
20095 parent namespace handles them. The empty prefix should always have this
20097 Defaults to @samp{#t}.
20100 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
20101 List of predefined mailboxes in this namespace.
20102 Defaults to @samp{()}.
20104 Available @code{mailbox-configuration} fields are:
20106 @deftypevr {@code{mailbox-configuration} parameter} string name
20107 Name for this mailbox.
20110 @deftypevr {@code{mailbox-configuration} parameter} string auto
20111 @samp{create} will automatically create this mailbox.
20112 @samp{subscribe} will both create and subscribe to the mailbox.
20113 Defaults to @samp{"no"}.
20116 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
20117 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
20118 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
20119 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
20120 Defaults to @samp{()}.
20127 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
20128 Base directory where to store runtime data.
20129 Defaults to @samp{"/var/run/dovecot/"}.
20132 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
20133 Greeting message for clients.
20134 Defaults to @samp{"Dovecot ready."}.
20137 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
20138 List of trusted network ranges. Connections from these IPs are
20139 allowed to override their IP addresses and ports (for logging and for
20140 authentication checks). @samp{disable-plaintext-auth} is also ignored
20141 for these networks. Typically you would specify your IMAP proxy servers
20143 Defaults to @samp{()}.
20146 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
20147 List of login access check sockets (e.g.@: tcpwrap).
20148 Defaults to @samp{()}.
20151 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
20152 Show more verbose process titles (in ps). Currently shows user name
20153 and IP address. Useful for seeing who is actually using the IMAP
20154 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
20156 Defaults to @samp{#f}.
20159 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
20160 Should all processes be killed when Dovecot master process shuts down.
20161 Setting this to @code{#f} means that Dovecot can be upgraded without
20162 forcing existing client connections to close (although that could also
20163 be a problem if the upgrade is e.g.@: due to a security fix).
20164 Defaults to @samp{#t}.
20167 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
20168 If non-zero, run mail commands via this many connections to doveadm
20169 server, instead of running them directly in the same process.
20170 Defaults to @samp{0}.
20173 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
20174 UNIX socket or host:port used for connecting to doveadm server.
20175 Defaults to @samp{"doveadm-server"}.
20178 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
20179 List of environment variables that are preserved on Dovecot startup
20180 and passed down to all of its child processes. You can also give
20181 key=value pairs to always set specific settings.
20184 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
20185 Disable LOGIN command and all other plaintext authentications unless
20186 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
20187 matches the local IP (i.e.@: you're connecting from the same computer),
20188 the connection is considered secure and plaintext authentication is
20189 allowed. See also ssl=required setting.
20190 Defaults to @samp{#t}.
20193 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
20194 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
20195 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
20196 for caching to be used.
20197 Defaults to @samp{0}.
20200 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
20201 Time to live for cached data. After TTL expires the cached record
20202 is no longer used, *except* if the main database lookup returns internal
20203 failure. We also try to handle password changes automatically: If
20204 user's previous authentication was successful, but this one wasn't, the
20205 cache isn't used. For now this works only with plaintext
20207 Defaults to @samp{"1 hour"}.
20210 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
20211 TTL for negative hits (user not found, password mismatch).
20212 0 disables caching them completely.
20213 Defaults to @samp{"1 hour"}.
20216 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
20217 List of realms for SASL authentication mechanisms that need them.
20218 You can leave it empty if you don't want to support multiple realms.
20219 Many clients simply use the first one listed here, so keep the default
20221 Defaults to @samp{()}.
20224 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
20225 Default realm/domain to use if none was specified. This is used for
20226 both SASL realms and appending @@domain to username in plaintext
20228 Defaults to @samp{""}.
20231 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
20232 List of allowed characters in username. If the user-given username
20233 contains a character not listed in here, the login automatically fails.
20234 This is just an extra check to make sure user can't exploit any
20235 potential quote escaping vulnerabilities with SQL/LDAP databases. If
20236 you want to allow all characters, set this value to empty.
20237 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
20240 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
20241 Username character translations before it's looked up from
20242 databases. The value contains series of from -> to characters. For
20243 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
20244 translated to @samp{@@}.
20245 Defaults to @samp{""}.
20248 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
20249 Username formatting before it's looked up from databases. You can
20250 use the standard variables here, e.g.@: %Lu would lowercase the username,
20251 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
20252 change the @samp{@@} into @samp{-AT-}. This translation is done after
20253 @samp{auth-username-translation} changes.
20254 Defaults to @samp{"%Lu"}.
20257 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
20258 If you want to allow master users to log in by specifying the master
20259 username within the normal username string (i.e.@: not using SASL
20260 mechanism's support for it), you can specify the separator character
20261 here. The format is then <username><separator><master username>.
20262 UW-IMAP uses @samp{*} as the separator, so that could be a good
20264 Defaults to @samp{""}.
20267 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
20268 Username to use for users logging in with ANONYMOUS SASL
20270 Defaults to @samp{"anonymous"}.
20273 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
20274 Maximum number of dovecot-auth worker processes. They're used to
20275 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
20276 They're automatically created and destroyed as needed.
20277 Defaults to @samp{30}.
20280 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
20281 Host name to use in GSSAPI principal names. The default is to use
20282 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
20283 allow all keytab entries.
20284 Defaults to @samp{""}.
20287 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
20288 Kerberos keytab to use for the GSSAPI mechanism. Will use the
20289 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
20290 need to change the auth service to run as root to be able to read this
20292 Defaults to @samp{""}.
20295 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
20296 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
20297 and @samp{ntlm-auth} helper.
20298 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
20299 Defaults to @samp{#f}.
20302 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
20303 Path for Samba's @samp{ntlm-auth} helper binary.
20304 Defaults to @samp{"/usr/bin/ntlm_auth"}.
20307 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
20308 Time to delay before replying to failed authentications.
20309 Defaults to @samp{"2 secs"}.
20312 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
20313 Require a valid SSL client certificate or the authentication
20315 Defaults to @samp{#f}.
20318 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
20319 Take the username from client's SSL certificate, using
20320 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
20322 Defaults to @samp{#f}.
20325 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
20326 List of wanted authentication mechanisms. Supported mechanisms are:
20327 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
20328 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
20329 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
20330 @samp{disable-plaintext-auth} setting.
20333 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
20334 List of IPs or hostnames to all director servers, including ourself.
20335 Ports can be specified as ip:port. The default port is the same as what
20336 director service's @samp{inet-listener} is using.
20337 Defaults to @samp{()}.
20340 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
20341 List of IPs or hostnames to all backend mail servers. Ranges are
20342 allowed too, like 10.0.0.10-10.0.0.30.
20343 Defaults to @samp{()}.
20346 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
20347 How long to redirect users to a specific server after it no longer
20348 has any connections.
20349 Defaults to @samp{"15 min"}.
20352 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
20353 How the username is translated before being hashed. Useful values
20354 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
20355 are shared within domain.
20356 Defaults to @samp{"%Lu"}.
20359 @deftypevr {@code{dovecot-configuration} parameter} string log-path
20360 Log file to use for error messages. @samp{syslog} logs to syslog,
20361 @samp{/dev/stderr} logs to stderr.
20362 Defaults to @samp{"syslog"}.
20365 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
20366 Log file to use for informational messages. Defaults to
20368 Defaults to @samp{""}.
20371 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
20372 Log file to use for debug messages. Defaults to
20373 @samp{info-log-path}.
20374 Defaults to @samp{""}.
20377 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
20378 Syslog facility to use if you're logging to syslog. Usually if you
20379 don't want to use @samp{mail}, you'll use local0..local7. Also other
20380 standard facilities are supported.
20381 Defaults to @samp{"mail"}.
20384 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
20385 Log unsuccessful authentication attempts and the reasons why they
20387 Defaults to @samp{#f}.
20390 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
20391 In case of password mismatches, log the attempted password. Valid
20392 values are no, plain and sha1. sha1 can be useful for detecting brute
20393 force password attempts vs. user simply trying the same password over
20394 and over again. You can also truncate the value to n chars by appending
20395 ":n" (e.g.@: sha1:6).
20396 Defaults to @samp{"no"}.
20399 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
20400 Even more verbose logging for debugging purposes. Shows for example
20402 Defaults to @samp{#f}.
20405 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
20406 In case of password mismatches, log the passwords and used scheme so
20407 the problem can be debugged. Enabling this also enables
20409 Defaults to @samp{#f}.
20412 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
20413 Enable mail process debugging. This can help you figure out why
20414 Dovecot isn't finding your mails.
20415 Defaults to @samp{#f}.
20418 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
20419 Show protocol level SSL errors.
20420 Defaults to @samp{#f}.
20423 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
20424 Prefix for each line written to log file. % codes are in
20425 strftime(3) format.
20426 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
20429 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
20430 List of elements we want to log. The elements which have a
20431 non-empty variable value are joined together to form a comma-separated
20435 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
20436 Login log format. %s contains @samp{login-log-format-elements}
20437 string, %$ contains the data we want to log.
20438 Defaults to @samp{"%$: %s"}.
20441 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
20442 Log prefix for mail processes. See doc/wiki/Variables.txt for list
20443 of possible variables you can use.
20444 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
20447 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
20448 Format to use for logging mail deliveries. You can use variables:
20451 Delivery status message (e.g.@: @samp{saved to INBOX})
20463 Defaults to @samp{"msgid=%m: %$"}.
20466 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
20467 Location for users' mailboxes. The default is empty, which means
20468 that Dovecot tries to find the mailboxes automatically. This won't work
20469 if the user doesn't yet have any mail, so you should explicitly tell
20470 Dovecot the full location.
20472 If you're using mbox, giving a path to the INBOX
20473 file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
20474 where the other mailboxes are kept. This is called the @emph{root mail
20475 directory}, and it must be the first path given in the
20476 @samp{mail-location} setting.
20478 There are a few special variables you can use, e.g.:
20484 user part in user@@domain, same as %u if there's no domain
20486 domain part in user@@domain, empty if there's no domain
20491 See doc/wiki/Variables.txt for full list. Some examples:
20493 @item maildir:~/Maildir
20494 @item mbox:~/mail:INBOX=/var/mail/%u
20495 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
20497 Defaults to @samp{""}.
20500 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
20501 System user and group used to access mails. If you use multiple,
20502 userdb can override these by returning uid or gid fields. You can use
20503 either numbers or names. <doc/wiki/UserIds.txt>.
20504 Defaults to @samp{""}.
20507 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
20509 Defaults to @samp{""}.
20512 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
20513 Group to enable temporarily for privileged operations. Currently
20514 this is used only with INBOX when either its initial creation or
20515 dotlocking fails. Typically this is set to @samp{"mail"} to give access to
20517 Defaults to @samp{""}.
20520 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
20521 Grant access to these supplementary groups for mail processes.
20522 Typically these are used to set up access to shared mailboxes. Note
20523 that it may be dangerous to set these if users can create symlinks
20524 (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
20525 could allow a user to delete others' mailboxes, or @code{ln -s
20526 /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
20530 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
20531 Allow full file system access to clients. There's no access checks
20532 other than what the operating system does for the active UID/GID@. It
20533 works with both maildir and mboxes, allowing you to prefix mailboxes
20534 names with e.g.@: @file{/path/} or @file{~user/}.
20535 Defaults to @samp{#f}.
20538 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
20539 Don't use @code{mmap()} at all. This is required if you store indexes to
20540 shared file systems (NFS or clustered file system).
20541 Defaults to @samp{#f}.
20544 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
20545 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
20546 supports @samp{O_EXCL} since version 3, so this should be safe to use
20547 nowadays by default.
20548 Defaults to @samp{#t}.
20551 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
20552 When to use fsync() or fdatasync() calls:
20555 Whenever necessary to avoid losing important data
20557 Useful with e.g.@: NFS when @code{write()}s are delayed
20559 Never use it (best performance, but crashes can lose data).
20561 Defaults to @samp{"optimized"}.
20564 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
20565 Mail storage exists in NFS@. Set this to yes to make Dovecot flush
20566 NFS caches whenever needed. If you're using only a single mail server
20568 Defaults to @samp{#f}.
20571 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
20572 Mail index files also exist in NFS@. Setting this to yes requires
20573 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
20574 Defaults to @samp{#f}.
20577 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
20578 Locking method for index files. Alternatives are fcntl, flock and
20579 dotlock. Dotlocking uses some tricks which may create more disk I/O
20580 than other locking methods. NFS users: flock doesn't work, remember to
20581 change @samp{mmap-disable}.
20582 Defaults to @samp{"fcntl"}.
20585 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
20586 Directory in which LDA/LMTP temporarily stores incoming mails >128
20588 Defaults to @samp{"/tmp"}.
20591 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
20592 Valid UID range for users. This is mostly to make sure that users can't
20593 log in as daemons or other system users. Note that denying root logins is
20594 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
20596 Defaults to @samp{500}.
20599 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
20601 Defaults to @samp{0}.
20604 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
20605 Valid GID range for users. Users having non-valid GID as primary group ID
20606 aren't allowed to log in. If user belongs to supplementary groups with
20607 non-valid GIDs, those groups are not set.
20608 Defaults to @samp{1}.
20611 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
20613 Defaults to @samp{0}.
20616 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
20617 Maximum allowed length for mail keyword name. It's only forced when
20618 trying to create new keywords.
20619 Defaults to @samp{50}.
20622 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
20623 List of directories under which chrooting is allowed for mail
20624 processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
20625 too). This setting doesn't affect @samp{login-chroot}
20626 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
20627 @samp{/./} in home dirs are ignored. WARNING: Never add directories here
20628 which local users can modify, that may lead to root exploit. Usually
20629 this should be done only if you don't allow shell access for users.
20630 <doc/wiki/Chrooting.txt>.
20631 Defaults to @samp{()}.
20634 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
20635 Default chroot directory for mail processes. This can be overridden
20636 for specific users in user database by giving @samp{/./} in user's home
20637 directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
20638 there is no real need to do chrooting, Dovecot doesn't allow users to
20639 access files outside their mail directory anyway. If your home
20640 directories are prefixed with the chroot directory, append @samp{/.} to
20641 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
20642 Defaults to @samp{""}.
20645 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
20646 UNIX socket path to master authentication server to find users.
20647 This is used by imap (for shared users) and lda.
20648 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
20651 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
20652 Directory where to look up mail plugins.
20653 Defaults to @samp{"/usr/lib/dovecot"}.
20656 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
20657 List of plugins to load for all services. Plugins specific to IMAP,
20658 LDA, etc.@: are added to this list in their own .conf files.
20659 Defaults to @samp{()}.
20662 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
20663 The minimum number of mails in a mailbox before updates are done to
20664 cache file. This allows optimizing Dovecot's behavior to do less disk
20665 writes at the cost of more disk reads.
20666 Defaults to @samp{0}.
20669 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
20670 When IDLE command is running, mailbox is checked once in a while to
20671 see if there are any new mails or other changes. This setting defines
20672 the minimum time to wait between those checks. Dovecot can also use
20673 dnotify, inotify and kqueue to find out immediately when changes
20675 Defaults to @samp{"30 secs"}.
20678 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
20679 Save mails with CR+LF instead of plain LF@. This makes sending those
20680 mails take less CPU, especially with sendfile() syscall with Linux and
20681 FreeBSD@. But it also creates a bit more disk I/O which may just make it
20682 slower. Also note that if other software reads the mboxes/maildirs,
20683 they may handle the extra CRs wrong and cause problems.
20684 Defaults to @samp{#f}.
20687 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
20688 By default LIST command returns all entries in maildir beginning
20689 with a dot. Enabling this option makes Dovecot return only entries
20690 which are directories. This is done by stat()ing each entry, so it
20691 causes more disk I/O.
20692 (For systems setting struct @samp{dirent->d_type} this check is free
20693 and it's done always regardless of this setting).
20694 Defaults to @samp{#f}.
20697 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
20698 When copying a message, do it with hard links whenever possible.
20699 This makes the performance much better, and it's unlikely to have any
20701 Defaults to @samp{#t}.
20704 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
20705 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
20706 directory only when its mtime changes unexpectedly or when we can't find
20707 the mail otherwise.
20708 Defaults to @samp{#f}.
20711 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
20712 Which locking methods to use for locking mbox. There are four
20717 Create <mailbox>.lock file. This is the oldest and most NFS-safe
20718 solution. If you want to use /var/mail/ like directory, the users will
20719 need write access to that directory.
20721 Same as dotlock, but if it fails because of permissions or because there
20722 isn't enough disk space, just skip it.
20724 Use this if possible. Works with NFS too if lockd is used.
20726 May not exist in all systems. Doesn't work with NFS.
20728 May not exist in all systems. Doesn't work with NFS.
20731 You can use multiple locking methods; if you do the order they're declared
20732 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
20733 locking methods as well. Some operating systems don't allow using some of
20734 them simultaneously.
20737 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
20741 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
20742 Maximum time to wait for lock (all of them) before aborting.
20743 Defaults to @samp{"5 mins"}.
20746 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
20747 If dotlock exists but the mailbox isn't modified in any way,
20748 override the lock file after this much time.
20749 Defaults to @samp{"2 mins"}.
20752 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
20753 When mbox changes unexpectedly we have to fully read it to find out
20754 what changed. If the mbox is large this can take a long time. Since
20755 the change is usually just a newly appended mail, it'd be faster to
20756 simply read the new mails. If this setting is enabled, Dovecot does
20757 this but still safely fallbacks to re-reading the whole mbox file
20758 whenever something in mbox isn't how it's expected to be. The only real
20759 downside to this setting is that if some other MUA changes message
20760 flags, Dovecot doesn't notice it immediately. Note that a full sync is
20761 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
20762 Defaults to @samp{#t}.
20765 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
20766 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
20767 EXAMINE, EXPUNGE or CHECK commands. If this is set,
20768 @samp{mbox-dirty-syncs} is ignored.
20769 Defaults to @samp{#f}.
20772 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
20773 Delay writing mbox headers until doing a full write sync (EXPUNGE
20774 and CHECK commands and when closing the mailbox). This is especially
20775 useful for POP3 where clients often delete all mails. The downside is
20776 that our changes aren't immediately visible to other MUAs.
20777 Defaults to @samp{#t}.
20780 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
20781 If mbox size is smaller than this (e.g.@: 100k), don't write index
20782 files. If an index file already exists it's still read, just not
20784 Defaults to @samp{0}.
20787 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
20788 Maximum dbox file size until it's rotated.
20789 Defaults to @samp{10000000}.
20792 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
20793 Maximum dbox file age until it's rotated. Typically in days. Day
20794 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
20796 Defaults to @samp{"1d"}.
20799 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
20800 When creating new mdbox files, immediately preallocate their size to
20801 @samp{mdbox-rotate-size}. This setting currently works only in Linux
20802 with some file systems (ext4, xfs).
20803 Defaults to @samp{#f}.
20806 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
20807 sdbox and mdbox support saving mail attachments to external files,
20808 which also allows single instance storage for them. Other backends
20809 don't support this for now.
20811 WARNING: This feature hasn't been tested much yet. Use at your own risk.
20813 Directory root where to store mail attachments. Disabled, if empty.
20814 Defaults to @samp{""}.
20817 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
20818 Attachments smaller than this aren't saved externally. It's also
20819 possible to write a plugin to disable saving specific attachments
20821 Defaults to @samp{128000}.
20824 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
20825 File system backend to use for saving attachments:
20828 No SiS done by Dovecot (but this might help FS's own deduplication)
20830 SiS with immediate byte-by-byte comparison during saving
20831 @item sis-queue posix
20832 SiS with delayed comparison and deduplication.
20834 Defaults to @samp{"sis posix"}.
20837 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
20838 Hash format to use in attachment filenames. You can add any text and
20839 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
20840 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
20841 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
20842 Defaults to @samp{"%@{sha1@}"}.
20845 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
20847 Defaults to @samp{100}.
20850 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
20852 Defaults to @samp{1000}.
20855 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
20856 Default VSZ (virtual memory size) limit for service processes.
20857 This is mainly intended to catch and kill processes that leak memory
20858 before they eat up everything.
20859 Defaults to @samp{256000000}.
20862 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
20863 Login user is internally used by login processes. This is the most
20864 untrusted user in Dovecot system. It shouldn't have access to anything
20866 Defaults to @samp{"dovenull"}.
20869 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
20870 Internal user is used by unprivileged processes. It should be
20871 separate from login user, so that login processes can't disturb other
20873 Defaults to @samp{"dovecot"}.
20876 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
20877 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
20878 Defaults to @samp{"required"}.
20881 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
20882 PEM encoded X.509 SSL/TLS certificate (public key).
20883 Defaults to @samp{"</etc/dovecot/default.pem"}.
20886 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
20887 PEM encoded SSL/TLS private key. The key is opened before
20888 dropping root privileges, so keep the key file unreadable by anyone but
20890 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
20893 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
20894 If key file is password protected, give the password here.
20895 Alternatively give it when starting dovecot with -p parameter. Since
20896 this file is often world-readable, you may want to place this setting
20897 instead to a different.
20898 Defaults to @samp{""}.
20901 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
20902 PEM encoded trusted certificate authority. Set this only if you
20903 intend to use @samp{ssl-verify-client-cert? #t}. The file should
20904 contain the CA certificate(s) followed by the matching
20905 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
20906 Defaults to @samp{""}.
20909 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
20910 Require that CRL check succeeds for client certificates.
20911 Defaults to @samp{#t}.
20914 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
20915 Request client to send a certificate. If you also want to require
20916 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
20917 Defaults to @samp{#f}.
20920 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
20921 Which field from certificate to use for username. commonName and
20922 x500UniqueIdentifier are the usual choices. You'll also need to set
20923 @samp{auth-ssl-username-from-cert? #t}.
20924 Defaults to @samp{"commonName"}.
20927 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
20928 Minimum SSL protocol version to accept.
20929 Defaults to @samp{"TLSv1"}.
20932 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
20933 SSL ciphers to use.
20934 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
20937 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
20938 SSL crypto device to use, for valid values run "openssl engine".
20939 Defaults to @samp{""}.
20942 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
20943 Address to use when sending rejection mails.
20944 %d expands to recipient domain.
20945 Defaults to @samp{"postmaster@@%d"}.
20948 @deftypevr {@code{dovecot-configuration} parameter} string hostname
20949 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
20950 and in LMTP replies. Default is the system's real hostname@@domain.
20951 Defaults to @samp{""}.
20954 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
20955 If user is over quota, return with temporary failure instead of
20957 Defaults to @samp{#f}.
20960 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
20961 Binary to use for sending mails.
20962 Defaults to @samp{"/usr/sbin/sendmail"}.
20965 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
20966 If non-empty, send mails via this SMTP host[:port] instead of
20968 Defaults to @samp{""}.
20971 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
20972 Subject: header to use for rejection mails. You can use the same
20973 variables as for @samp{rejection-reason} below.
20974 Defaults to @samp{"Rejected: %s"}.
20977 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
20978 Human readable error message for rejection mails. You can use
20991 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
20994 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
20995 Delimiter character between local-part and detail in email
20997 Defaults to @samp{"+"}.
21000 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
21001 Header where the original recipient address (SMTP's RCPT TO:
21002 address) is taken from if not available elsewhere. With dovecot-lda -a
21003 parameter overrides this. A commonly used header for this is
21005 Defaults to @samp{""}.
21008 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
21009 Should saving a mail to a nonexistent mailbox automatically create
21011 Defaults to @samp{#f}.
21014 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
21015 Should automatically created mailboxes be also automatically
21017 Defaults to @samp{#f}.
21020 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
21021 Maximum IMAP command line length. Some clients generate very long
21022 command lines with huge mailboxes, so you may need to raise this if you
21023 get "Too long argument" or "IMAP command line too large" errors
21025 Defaults to @samp{64000}.
21028 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
21029 IMAP logout format string:
21032 total number of bytes read from client
21034 total number of bytes sent to client.
21036 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
21037 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@}"}.
21040 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
21041 Override the IMAP CAPABILITY response. If the value begins with '+',
21042 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
21043 Defaults to @samp{""}.
21046 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
21047 How long to wait between "OK Still here" notifications when client
21049 Defaults to @samp{"2 mins"}.
21052 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
21053 ID field names and values to send to clients. Using * as the value
21054 makes Dovecot use the default value. The following fields have default
21055 values currently: name, version, os, os-version, support-url,
21057 Defaults to @samp{""}.
21060 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
21061 ID fields sent by client to log. * means everything.
21062 Defaults to @samp{""}.
21065 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
21066 Workarounds for various client bugs:
21069 @item delay-newmail
21070 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
21071 CHECK commands. Some clients ignore them otherwise, for example OSX
21072 Mail (<v2.1). Outlook Express breaks more badly though, without this it
21073 may show user "Message no longer in server" errors. Note that OE6
21074 still breaks even with this workaround if synchronization is set to
21077 @item tb-extra-mailbox-sep
21078 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
21079 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
21080 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
21082 @item tb-lsub-flags
21083 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
21084 This makes Thunderbird realize they aren't selectable and show them
21085 greyed out, instead of only later giving "not selectable" popup error.
21087 Defaults to @samp{()}.
21090 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
21091 Host allowed in URLAUTH URLs sent by client. "*" allows all.
21092 Defaults to @samp{""}.
21096 Whew! Lots of configuration options. The nice thing about it though is
21097 that Guix has a complete interface to Dovecot's configuration
21098 language. This allows not only a nice way to declare configurations,
21099 but also offers reflective capabilities as well: users can write code to
21100 inspect and transform configurations from within Scheme.
21102 However, it could be that you just want to get a @code{dovecot.conf} up
21103 and running. In that case, you can pass an
21104 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
21105 @code{dovecot-service}. As its name indicates, an opaque configuration
21106 does not have easy reflective capabilities.
21108 Available @code{opaque-dovecot-configuration} fields are:
21110 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
21111 The dovecot package.
21114 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
21115 The contents of the @code{dovecot.conf}, as a string.
21118 For example, if your @code{dovecot.conf} is just the empty string, you
21119 could instantiate a dovecot service like this:
21122 (dovecot-service #:config
21123 (opaque-dovecot-configuration
21127 @subsubheading OpenSMTPD Service
21129 @deffn {Scheme Variable} opensmtpd-service-type
21130 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
21131 service, whose value should be an @code{opensmtpd-configuration} object
21132 as in this example:
21135 (service opensmtpd-service-type
21136 (opensmtpd-configuration
21137 (config-file (local-file "./my-smtpd.conf"))))
21141 @deftp {Data Type} opensmtpd-configuration
21142 Data type representing the configuration of opensmtpd.
21145 @item @code{package} (default: @var{opensmtpd})
21146 Package object of the OpenSMTPD SMTP server.
21148 @item @code{config-file} (default: @code{%default-opensmtpd-file})
21149 File-like object of the OpenSMTPD configuration file to use. By default
21150 it listens on the loopback network interface, and allows for mail from
21151 users and daemons on the local machine, as well as permitting email to
21152 remote servers. Run @command{man smtpd.conf} for more information.
21157 @subsubheading Exim Service
21159 @cindex mail transfer agent (MTA)
21160 @cindex MTA (mail transfer agent)
21163 @deffn {Scheme Variable} exim-service-type
21164 This is the type of the @uref{https://exim.org, Exim} mail transfer
21165 agent (MTA), whose value should be an @code{exim-configuration} object
21166 as in this example:
21169 (service exim-service-type
21170 (exim-configuration
21171 (config-file (local-file "./my-exim.conf"))))
21175 In order to use an @code{exim-service-type} service you must also have a
21176 @code{mail-aliases-service-type} service present in your
21177 @code{operating-system} (even if it has no aliases).
21179 @deftp {Data Type} exim-configuration
21180 Data type representing the configuration of exim.
21183 @item @code{package} (default: @var{exim})
21184 Package object of the Exim server.
21186 @item @code{config-file} (default: @code{#f})
21187 File-like object of the Exim configuration file to use. If its value is
21188 @code{#f} then use the default configuration file from the package
21189 provided in @code{package}. The resulting configuration file is loaded
21190 after setting the @code{exim_user} and @code{exim_group} configuration
21196 @subsubheading Getmail service
21201 @deffn {Scheme Variable} getmail-service-type
21202 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
21203 mail retriever, whose value should be an @code{getmail-configuration}.
21206 Available @code{getmail-configuration} fields are:
21208 @deftypevr {@code{getmail-configuration} parameter} symbol name
21209 A symbol to identify the getmail service.
21211 Defaults to @samp{"unset"}.
21215 @deftypevr {@code{getmail-configuration} parameter} package package
21216 The getmail package to use.
21220 @deftypevr {@code{getmail-configuration} parameter} string user
21221 The user to run getmail as.
21223 Defaults to @samp{"getmail"}.
21227 @deftypevr {@code{getmail-configuration} parameter} string group
21228 The group to run getmail as.
21230 Defaults to @samp{"getmail"}.
21234 @deftypevr {@code{getmail-configuration} parameter} string directory
21235 The getmail directory to use.
21237 Defaults to @samp{"/var/lib/getmail/default"}.
21241 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
21242 The getmail configuration file to use.
21244 Available @code{getmail-configuration-file} fields are:
21246 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
21247 What mail account to retrieve mail from, and how to access that account.
21249 Available @code{getmail-retriever-configuration} fields are:
21251 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
21252 The type of mail retriever to use. Valid values include @samp{passwd}
21255 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
21259 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
21260 Username to login to the mail server with.
21262 Defaults to @samp{unset}.
21266 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
21267 Username to login to the mail server with.
21269 Defaults to @samp{unset}.
21273 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
21274 Port number to connect to.
21276 Defaults to @samp{#f}.
21280 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
21281 Override fields from passwd.
21283 Defaults to @samp{""}.
21287 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
21288 Override fields from passwd.
21290 Defaults to @samp{()}.
21294 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
21295 PEM-formatted key file to use for the TLS negotiation.
21297 Defaults to @samp{""}.
21301 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
21302 PEM-formatted certificate file to use for the TLS negotiation.
21304 Defaults to @samp{""}.
21308 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
21309 CA certificates to use.
21311 Defaults to @samp{""}.
21315 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
21316 Extra retriever parameters.
21318 Defaults to @samp{()}.
21324 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
21325 What to do with retrieved messages.
21327 Available @code{getmail-destination-configuration} fields are:
21329 @deftypevr {@code{getmail-destination-configuration} parameter} string type
21330 The type of mail destination. Valid values include @samp{Maildir},
21331 @samp{Mboxrd} and @samp{MDA_external}.
21333 Defaults to @samp{unset}.
21337 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
21338 The path option for the mail destination. The behaviour depends on the
21341 Defaults to @samp{""}.
21345 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
21346 Extra destination parameters
21348 Defaults to @samp{()}.
21354 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
21357 Available @code{getmail-options-configuration} fields are:
21359 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
21360 If set to @samp{0}, getmail will only print warnings and errors. A
21361 value of @samp{1} means that messages will be printed about retrieving
21362 and deleting messages. If set to @samp{2}, getmail will print messages
21363 about each of it's actions.
21365 Defaults to @samp{1}.
21369 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
21370 If true, getmail will retrieve all available messages. Otherwise it
21371 will only retrieve messages it hasn't seen previously.
21373 Defaults to @samp{#t}.
21377 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
21378 If set to true, messages will be deleted from the server after
21379 retrieving and successfully delivering them. Otherwise, messages will
21380 be left on the server.
21382 Defaults to @samp{#f}.
21386 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
21387 Getmail will delete messages this number of days after seeing them, if
21388 they have been delivered. This means messages will be left on the
21389 server this number of days after delivering them. A value of @samp{0}
21390 disabled this feature.
21392 Defaults to @samp{0}.
21396 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
21397 Delete messages larger than this of bytes after retrieving them, even if
21398 the delete and delete-after options are disabled. A value of @samp{0}
21399 disables this feature.
21401 Defaults to @samp{0}.
21405 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
21406 Retrieve messages totalling up to this number of bytes before closing
21407 the session with the server. A value of @samp{0} disables this feature.
21409 Defaults to @samp{0}.
21413 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
21414 Don't retrieve messages larger than this number of bytes. A value of
21415 @samp{0} disables this feature.
21417 Defaults to @samp{0}.
21421 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
21422 If true, getmail will add a Delivered-To header to messages.
21424 Defaults to @samp{#t}.
21428 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
21429 If set, getmail adds a Received header to the messages.
21431 Defaults to @samp{#t}.
21435 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
21436 Getmail will record a log of its actions to the named file. A value of
21437 @samp{""} disables this feature.
21439 Defaults to @samp{""}.
21443 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
21444 If true, getmail will record a log of its actions using the system
21447 Defaults to @samp{#f}.
21451 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
21452 If true, getmail will log information about messages not retrieved and
21453 the reason for not retrieving them, as well as starting and ending
21456 Defaults to @samp{#f}.
21460 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
21461 Extra options to include.
21463 Defaults to @samp{()}.
21471 @deftypevr {@code{getmail-configuration} parameter} list idle
21472 A list of mailboxes that getmail should wait on the server for new mail
21473 notifications. This depends on the server supporting the IDLE
21476 Defaults to @samp{()}.
21480 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
21481 Environment variables to set for getmail.
21483 Defaults to @samp{()}.
21487 @subsubheading Mail Aliases Service
21489 @cindex email aliases
21490 @cindex aliases, for email addresses
21492 @deffn {Scheme Variable} mail-aliases-service-type
21493 This is the type of the service which provides @code{/etc/aliases},
21494 specifying how to deliver mail to users on this system.
21497 (service mail-aliases-service-type
21498 '(("postmaster" "bob")
21499 ("bob" "bob@@example.com" "bob@@example2.com")))
21503 The configuration for a @code{mail-aliases-service-type} service is an
21504 association list denoting how to deliver mail that comes to this
21505 system. Each entry is of the form @code{(alias addresses ...)}, with
21506 @code{alias} specifying the local alias and @code{addresses} specifying
21507 where to deliver this user's mail.
21509 The aliases aren't required to exist as users on the local system. In
21510 the above example, there doesn't need to be a @code{postmaster} entry in
21511 the @code{operating-system}'s @code{user-accounts} in order to deliver
21512 the @code{postmaster} mail to @code{bob} (which subsequently would
21513 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
21515 @subsubheading GNU Mailutils IMAP4 Daemon
21516 @cindex GNU Mailutils IMAP4 Daemon
21518 @deffn {Scheme Variable} imap4d-service-type
21519 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
21520 mailutils, GNU Mailutils Manual}), whose value should be an
21521 @code{imap4d-configuration} object as in this example:
21524 (service imap4d-service-type
21525 (imap4d-configuration
21526 (config-file (local-file "imap4d.conf"))))
21530 @deftp {Data Type} imap4d-configuration
21531 Data type representing the configuration of @command{imap4d}.
21534 @item @code{package} (default: @code{mailutils})
21535 The package that provides @command{imap4d}.
21537 @item @code{config-file} (default: @code{%default-imap4d-config-file})
21538 File-like object of the configuration file to use, by default it will listen
21539 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
21540 Mailutils Manual}, for details.
21545 @subsubheading Radicale Service
21549 @deffn {Scheme Variable} radicale-service-type
21550 This is the type of the @uref{https://radicale.org, Radicale} CalDAV/CardDAV
21551 server whose value should be a @code{radicale-configuration}.
21554 @deftp {Data Type} radicale-configuration
21555 Data type representing the configuration of @command{radicale}.
21558 @item @code{package} (default: @code{radicale})
21559 The package that provides @command{radicale}.
21561 @item @code{config-file} (default: @code{%default-radicale-config-file})
21562 File-like object of the configuration file to use, by default it will listen
21563 on TCP port 5232 of @code{localhost} and use the @code{htpasswd} file at
21564 @file{/var/lib/radicale/users} with no (@code{plain}) encryption.
21569 @node Messaging Services
21570 @subsection Messaging Services
21575 The @code{(gnu services messaging)} module provides Guix service
21576 definitions for messaging services. Currently it provides the following
21579 @subsubheading Prosody Service
21581 @deffn {Scheme Variable} prosody-service-type
21582 This is the type for the @uref{https://prosody.im, Prosody XMPP
21583 communication server}. Its value must be a @code{prosody-configuration}
21584 record as in this example:
21587 (service prosody-service-type
21588 (prosody-configuration
21589 (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
21592 (int-component-configuration
21593 (hostname "conference.example.net")
21595 (mod-muc (mod-muc-configuration)))))
21598 (virtualhost-configuration
21599 (domain "example.net"))))))
21602 See below for details about @code{prosody-configuration}.
21606 By default, Prosody does not need much configuration. Only one
21607 @code{virtualhosts} field is needed: it specifies the domain you wish
21610 You can perform various sanity checks on the generated configuration
21611 with the @code{prosodyctl check} command.
21613 Prosodyctl will also help you to import certificates from the
21614 @code{letsencrypt} directory so that the @code{prosody} user can access
21615 them. See @url{https://prosody.im/doc/letsencrypt}.
21618 prosodyctl --root cert import /etc/letsencrypt/live
21621 The available configuration parameters follow. Each parameter
21622 definition is preceded by its type; for example, @samp{string-list foo}
21623 indicates that the @code{foo} parameter should be specified as a list of
21624 strings. Types starting with @code{maybe-} denote parameters that won't
21625 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
21627 There is also a way to specify the configuration as a string, if you
21628 have an old @code{prosody.cfg.lua} file that you want to port over from
21629 some other system; see the end for more details.
21631 The @code{file-object} type designates either a file-like object
21632 (@pxref{G-Expressions, file-like objects}) or a file name.
21634 @c The following documentation was initially generated by
21635 @c (generate-documentation) in (gnu services messaging). Manually maintained
21636 @c documentation is better, so we shouldn't hesitate to edit below as
21637 @c needed. However if the change you want to make to this documentation
21638 @c can be done in an automated way, it's probably easier to change
21639 @c (generate-documentation) than to make it below and have to deal with
21640 @c the churn as Prosody updates.
21642 Available @code{prosody-configuration} fields are:
21644 @deftypevr {@code{prosody-configuration} parameter} package prosody
21645 The Prosody package.
21648 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
21649 Location of the Prosody data storage directory. See
21650 @url{https://prosody.im/doc/configure}.
21651 Defaults to @samp{"/var/lib/prosody"}.
21654 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
21655 Additional plugin directories. They are searched in all the specified
21656 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
21657 Defaults to @samp{()}.
21660 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
21661 Every virtual host and component needs a certificate so that clients and
21662 servers can securely verify its identity. Prosody will automatically load
21663 certificates/keys from the directory specified here.
21664 Defaults to @samp{"/etc/prosody/certs"}.
21667 @deftypevr {@code{prosody-configuration} parameter} string-list admins
21668 This is a list of accounts that are admins for the server. Note that you
21669 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
21670 @url{https://prosody.im/doc/creating_accounts}.
21671 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
21672 Defaults to @samp{()}.
21675 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
21676 Enable use of libevent for better performance under high load. See
21677 @url{https://prosody.im/doc/libevent}.
21678 Defaults to @samp{#f}.
21681 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
21682 This is the list of modules Prosody will load on startup. It looks for
21683 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
21684 Documentation on modules can be found at:
21685 @url{https://prosody.im/doc/modules}.
21686 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
21689 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
21690 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
21691 should you want to disable them then add them to this list.
21692 Defaults to @samp{()}.
21695 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
21696 Path to a text file where the shared groups are defined. If this path is
21697 empty then @samp{mod_groups} does nothing. See
21698 @url{https://prosody.im/doc/modules/mod_groups}.
21699 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
21702 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
21703 Disable account creation by default, for security. See
21704 @url{https://prosody.im/doc/creating_accounts}.
21705 Defaults to @samp{#f}.
21708 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
21709 These are the SSL/TLS-related settings. Most of them are disabled so to
21710 use Prosody's defaults. If you do not completely understand these options, do
21711 not add them to your config, it is easy to lower the security of your server
21712 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
21714 Available @code{ssl-configuration} fields are:
21716 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
21717 This determines what handshake to use.
21720 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
21721 Path to your private key file.
21724 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
21725 Path to your certificate file.
21728 @deftypevr {@code{ssl-configuration} parameter} file-object capath
21729 Path to directory containing root certificates that you wish Prosody to
21730 trust when verifying the certificates of remote servers.
21731 Defaults to @samp{"/etc/ssl/certs"}.
21734 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
21735 Path to a file containing root certificates that you wish Prosody to trust.
21736 Similar to @code{capath} but with all certificates concatenated together.
21739 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
21740 A list of verification options (these mostly map to OpenSSL's
21741 @code{set_verify()} flags).
21744 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
21745 A list of general options relating to SSL/TLS@. These map to OpenSSL's
21746 @code{set_options()}. For a full list of options available in LuaSec, see the
21750 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
21751 How long a chain of certificate authorities to check when looking for a
21752 trusted root certificate.
21755 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
21756 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
21757 clients, and in what order.
21760 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
21761 A path to a file containing parameters for Diffie-Hellman key exchange. You
21762 can create such a file with:
21763 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
21766 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
21767 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
21768 @samp{"secp384r1"}.
21771 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
21772 A list of ``extra'' verification options.
21775 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
21776 Password for encrypted private keys.
21781 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
21782 Whether to force all client-to-server connections to be encrypted or not.
21783 See @url{https://prosody.im/doc/modules/mod_tls}.
21784 Defaults to @samp{#f}.
21787 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
21788 Set of mechanisms that will never be offered. See
21789 @url{https://prosody.im/doc/modules/mod_saslauth}.
21790 Defaults to @samp{("DIGEST-MD5")}.
21793 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
21794 Whether to force all server-to-server connections to be encrypted or not.
21795 See @url{https://prosody.im/doc/modules/mod_tls}.
21796 Defaults to @samp{#f}.
21799 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
21800 Whether to require encryption and certificate authentication. This
21801 provides ideal security, but requires servers you communicate with to support
21802 encryption AND present valid, trusted certificates. See
21803 @url{https://prosody.im/doc/s2s#security}.
21804 Defaults to @samp{#f}.
21807 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
21808 Many servers don't support encryption or have invalid or self-signed
21809 certificates. You can list domains here that will not be required to
21810 authenticate using certificates. They will be authenticated using DNS@. See
21811 @url{https://prosody.im/doc/s2s#security}.
21812 Defaults to @samp{()}.
21815 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
21816 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
21817 valid certificates for some domains by specifying a list here. See
21818 @url{https://prosody.im/doc/s2s#security}.
21819 Defaults to @samp{()}.
21822 @deftypevr {@code{prosody-configuration} parameter} string authentication
21823 Select the authentication backend to use. The default provider stores
21824 passwords in plaintext and uses Prosody's configured data storage to store the
21825 authentication data. If you do not trust your server please see
21826 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
21827 about using the hashed backend. See also
21828 @url{https://prosody.im/doc/authentication}
21829 Defaults to @samp{"internal_plain"}.
21832 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
21833 Set logging options. Advanced logging configuration is not yet supported
21834 by the Prosody service. See @url{https://prosody.im/doc/logging}.
21835 Defaults to @samp{"*syslog"}.
21838 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
21839 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
21840 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
21843 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
21844 Maximum allowed size of the HTTP body (in bytes).
21847 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
21848 Some modules expose their own URL in various ways. This URL is built
21849 from the protocol, host and port used. If Prosody sits behind a proxy, the
21850 public URL will be @code{http-external-url} instead. See
21851 @url{https://prosody.im/doc/http#external_url}.
21854 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
21855 A host in Prosody is a domain on which user accounts can be created. For
21856 example if you want your users to have addresses like
21857 @samp{"john.smith@@example.com"} then you need to add a host
21858 @samp{"example.com"}. All options in this list will apply only to this host.
21860 Note: the name @emph{virtual} host is used in configuration to avoid confusion with
21861 the actual physical host that Prosody is installed on. A single Prosody
21862 instance can serve many domains, each one defined as a VirtualHost entry in
21863 Prosody's configuration. Conversely a server that hosts a single domain would
21864 have just one VirtualHost entry.
21866 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
21868 Available @code{virtualhost-configuration} fields are:
21870 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:
21871 @deftypevr {@code{virtualhost-configuration} parameter} string domain
21872 Domain you wish Prosody to serve.
21877 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
21878 Components are extra services on a server which are available to clients,
21879 usually on a subdomain of the main server (such as
21880 @samp{"mycomponent.example.com"}). Example components might be chatroom
21881 servers, user directories, or gateways to other protocols.
21883 Internal components are implemented with Prosody-specific plugins. To add an
21884 internal component, you simply fill the hostname field, and the plugin you wish
21885 to use for the component.
21887 See @url{https://prosody.im/doc/components}.
21888 Defaults to @samp{()}.
21890 Available @code{int-component-configuration} fields are:
21892 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:
21893 @deftypevr {@code{int-component-configuration} parameter} string hostname
21894 Hostname of the component.
21897 @deftypevr {@code{int-component-configuration} parameter} string plugin
21898 Plugin you wish to use for the component.
21901 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
21902 Multi-user chat (MUC) is Prosody's module for allowing you to create
21903 hosted chatrooms/conferences for XMPP users.
21905 General information on setting up and using multi-user chatrooms can be found
21906 in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
21907 which you should read if you are new to XMPP chatrooms.
21909 See also @url{https://prosody.im/doc/modules/mod_muc}.
21911 Available @code{mod-muc-configuration} fields are:
21913 @deftypevr {@code{mod-muc-configuration} parameter} string name
21914 The name to return in service discovery responses.
21915 Defaults to @samp{"Prosody Chatrooms"}.
21918 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
21919 If @samp{#t}, this will only allow admins to create new chatrooms.
21920 Otherwise anyone can create a room. The value @samp{"local"} restricts room
21921 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
21922 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
21923 restricts to service administrators only.
21924 Defaults to @samp{#f}.
21927 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
21928 Maximum number of history messages that will be sent to the member that has
21929 just joined the room.
21930 Defaults to @samp{20}.
21937 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
21938 External components use XEP-0114, which most standalone components
21939 support. To add an external component, you simply fill the hostname field. See
21940 @url{https://prosody.im/doc/components}.
21941 Defaults to @samp{()}.
21943 Available @code{ext-component-configuration} fields are:
21945 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:
21946 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
21947 Password which the component will use to log in.
21950 @deftypevr {@code{ext-component-configuration} parameter} string hostname
21951 Hostname of the component.
21956 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
21957 Port(s) Prosody listens on for component connections.
21958 Defaults to @samp{(5347)}.
21961 @deftypevr {@code{prosody-configuration} parameter} string component-interface
21962 Interface Prosody listens on for component connections.
21963 Defaults to @samp{"127.0.0.1"}.
21966 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
21967 Raw content that will be added to the configuration file.
21970 It could be that you just want to get a @code{prosody.cfg.lua}
21971 up and running. In that case, you can pass an
21972 @code{opaque-prosody-configuration} record as the value of
21973 @code{prosody-service-type}. As its name indicates, an opaque configuration
21974 does not have easy reflective capabilities.
21975 Available @code{opaque-prosody-configuration} fields are:
21977 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
21978 The prosody package.
21981 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
21982 The contents of the @code{prosody.cfg.lua} to use.
21985 For example, if your @code{prosody.cfg.lua} is just the empty
21986 string, you could instantiate a prosody service like this:
21989 (service prosody-service-type
21990 (opaque-prosody-configuration
21991 (prosody.cfg.lua "")))
21994 @c end of Prosody auto-generated documentation
21996 @subsubheading BitlBee Service
21998 @cindex IRC (Internet Relay Chat)
21999 @cindex IRC gateway
22000 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
22001 interface to a variety of messaging protocols such as XMPP.
22003 @defvr {Scheme Variable} bitlbee-service-type
22004 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
22005 gateway daemon. Its value is a @code{bitlbee-configuration} (see
22008 To have BitlBee listen on port 6667 on localhost, add this line to your
22012 (service bitlbee-service-type)
22016 @deftp {Data Type} bitlbee-configuration
22017 This is the configuration for BitlBee, with the following fields:
22020 @item @code{interface} (default: @code{"127.0.0.1"})
22021 @itemx @code{port} (default: @code{6667})
22022 Listen on the network interface corresponding to the IP address
22023 specified in @var{interface}, on @var{port}.
22025 When @var{interface} is @code{127.0.0.1}, only local clients can
22026 connect; when it is @code{0.0.0.0}, connections can come from any
22027 networking interface.
22029 @item @code{bitlbee} (default: @code{bitlbee})
22030 The BitlBee package to use.
22032 @item @code{plugins} (default: @code{'()})
22033 List of plugin packages to use---e.g., @code{bitlbee-discord}.
22035 @item @code{extra-settings} (default: @code{""})
22036 Configuration snippet added as-is to the BitlBee configuration file.
22040 @subsubheading Quassel Service
22042 @cindex IRC (Internet Relay Chat)
22043 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
22044 meaning that one or more clients can attach to and detach from the
22047 @defvr {Scheme Variable} quassel-service-type
22048 This is the service type for the @url{https://quassel-irc.org/,Quassel}
22049 IRC backend daemon. Its value is a @code{quassel-configuration}
22053 @deftp {Data Type} quassel-configuration
22054 This is the configuration for Quassel, with the following fields:
22057 @item @code{quassel} (default: @code{quassel})
22058 The Quassel package to use.
22060 @item @code{interface} (default: @code{"::,0.0.0.0"})
22061 @item @code{port} (default: @code{4242})
22062 Listen on the network interface(s) corresponding to the IPv4 or IPv6
22063 interfaces specified in the comma delimited @var{interface}, on
22066 @item @code{loglevel} (default: @code{"Info"})
22067 The level of logging desired. Accepted values are Debug, Info, Warning
22072 @node Telephony Services
22073 @subsection Telephony Services
22075 @cindex Murmur (VoIP server)
22076 @cindex VoIP server
22077 This section describes how to set up and run a Murmur server. Murmur is
22078 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
22081 @deftp {Data Type} murmur-configuration
22082 The service type for the Murmur server. An example configuration can
22086 (service murmur-service-type
22087 (murmur-configuration
22089 "Welcome to this Mumble server running on Guix!")
22090 (cert-required? #t) ;disallow text password logins
22091 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
22092 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
22095 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
22096 password with the command that is printed during the activation phase.
22098 It is recommended to register a normal Mumble user account
22099 and grant it admin or moderator rights.
22100 You can use the @code{mumble} client to
22101 login as new normal user, register yourself, and log out.
22102 For the next step login with the name @code{SuperUser} use
22103 the @code{SuperUser} password that you set previously,
22104 and grant your newly registered mumble user administrator or moderator
22105 rights and create some channels.
22107 Available @code{murmur-configuration} fields are:
22110 @item @code{package} (default: @code{mumble})
22111 Package that contains @code{bin/murmurd}.
22113 @item @code{user} (default: @code{"murmur"})
22114 User who will run the Murmur server.
22116 @item @code{group} (default: @code{"murmur"})
22117 Group of the user who will run the murmur server.
22119 @item @code{port} (default: @code{64738})
22120 Port on which the server will listen.
22122 @item @code{welcome-text} (default: @code{""})
22123 Welcome text sent to clients when they connect.
22125 @item @code{server-password} (default: @code{""})
22126 Password the clients have to enter in order to connect.
22128 @item @code{max-users} (default: @code{100})
22129 Maximum of users that can be connected to the server at once.
22131 @item @code{max-user-bandwidth} (default: @code{#f})
22132 Maximum voice traffic a user can send per second.
22134 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
22135 File name of the sqlite database.
22136 The service's user will become the owner of the directory.
22138 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
22139 File name of the log file.
22140 The service's user will become the owner of the directory.
22142 @item @code{autoban-attempts} (default: @code{10})
22143 Maximum number of logins a user can make in @code{autoban-timeframe}
22144 without getting auto banned for @code{autoban-time}.
22146 @item @code{autoban-timeframe} (default: @code{120})
22147 Timeframe for autoban in seconds.
22149 @item @code{autoban-time} (default: @code{300})
22150 Amount of time in seconds for which a client gets banned
22151 when violating the autoban limits.
22153 @item @code{opus-threshold} (default: @code{100})
22154 Percentage of clients that need to support opus
22155 before switching over to opus audio codec.
22157 @item @code{channel-nesting-limit} (default: @code{10})
22158 How deep channels can be nested at maximum.
22160 @item @code{channelname-regex} (default: @code{#f})
22161 A string in form of a Qt regular expression that channel names must conform to.
22163 @item @code{username-regex} (default: @code{#f})
22164 A string in form of a Qt regular expression that user names must conform to.
22166 @item @code{text-message-length} (default: @code{5000})
22167 Maximum size in bytes that a user can send in one text chat message.
22169 @item @code{image-message-length} (default: @code{(* 128 1024)})
22170 Maximum size in bytes that a user can send in one image message.
22172 @item @code{cert-required?} (default: @code{#f})
22173 If it is set to @code{#t} clients that use weak password authentication
22174 will not be accepted. Users must have completed the certificate wizard to join.
22176 @item @code{remember-channel?} (default: @code{#f})
22177 Should murmur remember the last channel each user was in when they disconnected
22178 and put them into the remembered channel when they rejoin.
22180 @item @code{allow-html?} (default: @code{#f})
22181 Should html be allowed in text messages, user comments, and channel descriptions.
22183 @item @code{allow-ping?} (default: @code{#f})
22184 Setting to true exposes the current user count, the maximum user count, and
22185 the server's maximum bandwidth per client to unauthenticated users. In the
22186 Mumble client, this information is shown in the Connect dialog.
22188 Disabling this setting will prevent public listing of the server.
22190 @item @code{bonjour?} (default: @code{#f})
22191 Should the server advertise itself in the local network through the bonjour protocol.
22193 @item @code{send-version?} (default: @code{#f})
22194 Should the murmur server version be exposed in ping requests.
22196 @item @code{log-days} (default: @code{31})
22197 Murmur also stores logs in the database, which are accessible via RPC.
22198 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
22199 or -1 to disable logging to the database.
22201 @item @code{obfuscate-ips?} (default: @code{#t})
22202 Should logged ips be obfuscated to protect the privacy of users.
22204 @item @code{ssl-cert} (default: @code{#f})
22205 File name of the SSL/TLS certificate used for encrypted connections.
22208 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
22210 @item @code{ssl-key} (default: @code{#f})
22211 Filepath to the ssl private key used for encrypted connections.
22213 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
22216 @item @code{ssl-dh-params} (default: @code{#f})
22217 File name of a PEM-encoded file with Diffie-Hellman parameters
22218 for the SSL/TLS encryption. Alternatively you set it to
22219 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
22220 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
22222 @item @code{ssl-ciphers} (default: @code{#f})
22223 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
22226 This option is specified using
22227 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
22228 OpenSSL cipher list notation}.
22230 It is recommended that you try your cipher string using 'openssl ciphers <string>'
22231 before setting it here, to get a feel for which cipher suites you will get.
22232 After setting this option, it is recommend that you inspect your Murmur log
22233 to ensure that Murmur is using the cipher suites that you expected it to.
22235 Note: Changing this option may impact the backwards compatibility of your
22236 Murmur server, and can remove the ability for older Mumble clients to be able
22239 @item @code{public-registration} (default: @code{#f})
22240 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
22242 You can optionally register your server in the public server list that the
22243 @code{mumble} client shows on startup.
22244 You cannot register your server if you have set a @code{server-password},
22245 or set @code{allow-ping} to @code{#f}.
22247 It might take a few hours until it shows up in the public list.
22249 @item @code{file} (default: @code{#f})
22250 Optional alternative override for this configuration.
22254 @deftp {Data Type} murmur-public-registration-configuration
22255 Configuration for public registration of a murmur service.
22259 This is a display name for your server. Not to be confused with the hostname.
22261 @item @code{password}
22262 A password to identify your registration.
22263 Subsequent updates will need the same password. Don't lose your password.
22266 This should be a @code{http://} or @code{https://} link to your web
22269 @item @code{hostname} (default: @code{#f})
22270 By default your server will be listed by its IP address.
22271 If it is set your server will be linked by this host name instead.
22277 @node Monitoring Services
22278 @subsection Monitoring Services
22280 @subsubheading Tailon Service
22282 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
22283 viewing and searching log files.
22285 The following example will configure the service with default values.
22286 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
22289 (service tailon-service-type)
22292 The following example customises more of the Tailon configuration,
22293 adding @command{sed} to the list of allowed commands.
22296 (service tailon-service-type
22297 (tailon-configuration
22299 (tailon-configuration-file
22300 (allowed-commands '("tail" "grep" "awk" "sed"))))))
22304 @deftp {Data Type} tailon-configuration
22305 Data type representing the configuration of Tailon.
22306 This type has the following parameters:
22309 @item @code{config-file} (default: @code{(tailon-configuration-file)})
22310 The configuration file to use for Tailon. This can be set to a
22311 @dfn{tailon-configuration-file} record value, or any gexp
22312 (@pxref{G-Expressions}).
22314 For example, to instead use a local file, the @code{local-file} function
22318 (service tailon-service-type
22319 (tailon-configuration
22320 (config-file (local-file "./my-tailon.conf"))))
22323 @item @code{package} (default: @code{tailon})
22324 The tailon package to use.
22329 @deftp {Data Type} tailon-configuration-file
22330 Data type representing the configuration options for Tailon.
22331 This type has the following parameters:
22334 @item @code{files} (default: @code{(list "/var/log")})
22335 List of files to display. The list can include strings for a single file
22336 or directory, or a list, where the first item is the name of a
22337 subsection, and the remaining items are the files or directories in that
22340 @item @code{bind} (default: @code{"localhost:8080"})
22341 Address and port to which Tailon should bind on.
22343 @item @code{relative-root} (default: @code{#f})
22344 URL path to use for Tailon, set to @code{#f} to not use a path.
22346 @item @code{allow-transfers?} (default: @code{#t})
22347 Allow downloading the log files in the web interface.
22349 @item @code{follow-names?} (default: @code{#t})
22350 Allow tailing of not-yet existent files.
22352 @item @code{tail-lines} (default: @code{200})
22353 Number of lines to read initially from each file.
22355 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
22356 Commands to allow running. By default, @code{sed} is disabled.
22358 @item @code{debug?} (default: @code{#f})
22359 Set @code{debug?} to @code{#t} to show debug messages.
22361 @item @code{wrap-lines} (default: @code{#t})
22362 Initial line wrapping state in the web interface. Set to @code{#t} to
22363 initially wrap lines (the default), or to @code{#f} to initially not
22366 @item @code{http-auth} (default: @code{#f})
22367 HTTP authentication type to use. Set to @code{#f} to disable
22368 authentication (the default). Supported values are @code{"digest"} or
22371 @item @code{users} (default: @code{#f})
22372 If HTTP authentication is enabled (see @code{http-auth}), access will be
22373 restricted to the credentials provided here. To configure users, use a
22374 list of pairs, where the first element of the pair is the username, and
22375 the 2nd element of the pair is the password.
22378 (tailon-configuration-file
22379 (http-auth "basic")
22380 (users '(("user1" . "password1")
22381 ("user2" . "password2"))))
22388 @subsubheading Darkstat Service
22390 Darkstat is a packet sniffer that captures network traffic, calculates
22391 statistics about usage, and serves reports over HTTP.
22393 @defvar {Scheme Variable} darkstat-service-type
22394 This is the service type for the
22395 @uref{https://unix4lyfe.org/darkstat/, darkstat}
22396 service, its value must be a @code{darkstat-configuration} record as in
22400 (service darkstat-service-type
22401 (darkstat-configuration
22402 (interface "eno1")))
22406 @deftp {Data Type} darkstat-configuration
22407 Data type representing the configuration of @command{darkstat}.
22410 @item @code{package} (default: @code{darkstat})
22411 The darkstat package to use.
22413 @item @code{interface}
22414 Capture traffic on the specified network interface.
22416 @item @code{port} (default: @code{"667"})
22417 Bind the web interface to the specified port.
22419 @item @code{bind-address} (default: @code{"127.0.0.1"})
22420 Bind the web interface to the specified address.
22422 @item @code{base} (default: @code{"/"})
22423 Specify the path of the base URL@. This can be useful if
22424 @command{darkstat} is accessed via a reverse proxy.
22429 @subsubheading Prometheus Node Exporter Service
22431 @cindex prometheus-node-exporter
22432 The Prometheus ``node exporter'' makes hardware and operating system statistics
22433 provided by the Linux kernel available for the Prometheus monitoring system.
22434 This service should be deployed on all physical nodes and virtual machines,
22435 where monitoring these statistics is desirable.
22437 @defvar {Scheme variable} prometheus-node-exporter-service-type
22438 This is the service type for the
22439 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
22440 service, its value must be a @code{prometheus-node-exporter-configuration}.
22443 (service prometheus-node-exporter-service-type)
22447 @deftp {Data Type} prometheus-node-exporter-configuration
22448 Data type representing the configuration of @command{node_exporter}.
22451 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
22452 The prometheus-node-exporter package to use.
22454 @item @code{web-listen-address} (default: @code{":9100"})
22455 Bind the web interface to the specified address.
22457 @item @code{textfile-directory} (default: @code{"/var/lib/prometheus/node-exporter"})
22458 This directory can be used to export metrics specific to this machine.
22459 Files containing metrics in the text format, with the filename ending in
22460 @code{.prom} should be placed in this directory.
22462 @item @code{extra-options} (default: @code{'()})
22463 Extra options to pass to the Prometheus node exporter.
22468 @subsubheading Zabbix server
22469 @cindex zabbix zabbix-server
22470 Zabbix provides monitoring metrics, among others network utilization, CPU load
22471 and disk space consumption:
22474 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
22475 @item Auto-discovery of servers and network devices and interfaces.
22476 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
22477 @item Distributed monitoring with centralized web administration.
22478 @item Native high performance agents.
22479 @item SLA, and ITIL KPI metrics on reporting.
22480 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
22481 @item Remote command execution through Zabbix proxies.
22484 @c %start of fragment
22486 Available @code{zabbix-server-configuration} fields are:
22488 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
22489 The zabbix-server package.
22493 @deftypevr {@code{zabbix-server-configuration} parameter} string user
22494 User who will run the Zabbix server.
22496 Defaults to @samp{"zabbix"}.
22500 @deftypevr {@code{zabbix-server-configuration} parameter} group group
22501 Group who will run the Zabbix server.
22503 Defaults to @samp{"zabbix"}.
22507 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
22508 Database host name.
22510 Defaults to @samp{"127.0.0.1"}.
22514 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
22517 Defaults to @samp{"zabbix"}.
22521 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
22524 Defaults to @samp{"zabbix"}.
22528 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
22529 Database password. Please, use @code{include-files} with
22530 @code{DBPassword=SECRET} inside a specified file instead.
22532 Defaults to @samp{""}.
22536 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
22539 Defaults to @samp{5432}.
22543 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
22544 Specifies where log messages are written to:
22548 @code{system} - syslog.
22551 @code{file} - file specified with @code{log-file} parameter.
22554 @code{console} - standard output.
22558 Defaults to @samp{""}.
22562 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
22563 Log file name for @code{log-type} @code{file} parameter.
22565 Defaults to @samp{"/var/log/zabbix/server.log"}.
22569 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
22572 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
22576 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
22577 The location of certificate authority (CA) files for SSL server
22578 certificate verification.
22580 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
22584 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
22585 Location of SSL client certificates.
22587 Defaults to @samp{"/etc/ssl/certs"}.
22591 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
22592 Extra options will be appended to Zabbix server configuration file.
22594 Defaults to @samp{""}.
22598 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
22599 You may include individual files or all files in a directory in the
22600 configuration file.
22602 Defaults to @samp{()}.
22606 @c %end of fragment
22608 @subsubheading Zabbix agent
22609 @cindex zabbix zabbix-agent
22611 Zabbix agent gathers information for Zabbix server.
22613 @c %start of fragment
22615 Available @code{zabbix-agent-configuration} fields are:
22617 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
22618 The zabbix-agent package.
22622 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
22623 User who will run the Zabbix agent.
22625 Defaults to @samp{"zabbix"}.
22629 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
22630 Group who will run the Zabbix agent.
22632 Defaults to @samp{"zabbix"}.
22636 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
22637 Unique, case sensitive hostname which is required for active checks and
22638 must match hostname as configured on the server.
22640 Defaults to @samp{""}.
22644 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
22645 Specifies where log messages are written to:
22649 @code{system} - syslog.
22652 @code{file} - file specified with @code{log-file} parameter.
22655 @code{console} - standard output.
22659 Defaults to @samp{""}.
22663 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
22664 Log file name for @code{log-type} @code{file} parameter.
22666 Defaults to @samp{"/var/log/zabbix/agent.log"}.
22670 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
22673 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
22677 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
22678 List of IP addresses, optionally in CIDR notation, or hostnames of
22679 Zabbix servers and Zabbix proxies. Incoming connections will be
22680 accepted only from the hosts listed here.
22682 Defaults to @samp{("127.0.0.1")}.
22686 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
22687 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
22688 proxies for active checks. If port is not specified, default port is
22689 used. If this parameter is not specified, active checks are disabled.
22691 Defaults to @samp{("127.0.0.1")}.
22695 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
22696 Extra options will be appended to Zabbix server configuration file.
22698 Defaults to @samp{""}.
22702 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
22703 You may include individual files or all files in a directory in the
22704 configuration file.
22706 Defaults to @samp{()}.
22710 @c %end of fragment
22712 @subsubheading Zabbix front-end
22713 @cindex zabbix zabbix-front-end
22715 This service provides a WEB interface to Zabbix server.
22717 @c %start of fragment
22719 Available @code{zabbix-front-end-configuration} fields are:
22721 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
22722 NGINX configuration.
22726 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
22727 Database host name.
22729 Defaults to @samp{"localhost"}.
22733 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
22736 Defaults to @samp{5432}.
22740 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
22743 Defaults to @samp{"zabbix"}.
22747 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
22750 Defaults to @samp{"zabbix"}.
22754 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
22755 Database password. Please, use @code{db-secret-file} instead.
22757 Defaults to @samp{""}.
22761 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
22762 Secret file containing the credentials for the Zabbix front-end. The value
22763 must be a local file name, not a G-expression. You are expected to create
22764 this file manually. Its contents will be copied into @file{zabbix.conf.php}
22765 as the value of @code{$DB['PASSWORD']}.
22767 Defaults to @samp{""}.
22771 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
22772 Zabbix server hostname.
22774 Defaults to @samp{"localhost"}.
22778 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
22779 Zabbix server port.
22781 Defaults to @samp{10051}.
22786 @c %end of fragment
22788 @node Kerberos Services
22789 @subsection Kerberos Services
22792 The @code{(gnu services kerberos)} module provides services relating to
22793 the authentication protocol @dfn{Kerberos}.
22795 @subsubheading Krb5 Service
22797 Programs using a Kerberos client library normally
22798 expect a configuration file in @file{/etc/krb5.conf}.
22799 This service generates such a file from a definition provided in the
22800 operating system declaration.
22801 It does not cause any daemon to be started.
22803 No ``keytab'' files are provided by this service---you must explicitly create them.
22804 This service is known to work with the MIT client library, @code{mit-krb5}.
22805 Other implementations have not been tested.
22807 @defvr {Scheme Variable} krb5-service-type
22808 A service type for Kerberos 5 clients.
22812 Here is an example of its use:
22814 (service krb5-service-type
22815 (krb5-configuration
22816 (default-realm "EXAMPLE.COM")
22817 (allow-weak-crypto? #t)
22820 (name "EXAMPLE.COM")
22821 (admin-server "groucho.example.com")
22822 (kdc "karl.example.com"))
22825 (admin-server "kerb-admin.argrx.edu")
22826 (kdc "keys.argrx.edu"))))))
22830 This example provides a Kerberos@tie{}5 client configuration which:
22832 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
22833 of which have distinct administration servers and key distribution centers;
22834 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
22835 specified by clients;
22836 @item Accepts services which only support encryption types known to be weak.
22839 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
22840 Only the most commonly used ones are described here.
22841 For a full list, and more detailed explanation of each, see the MIT
22842 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
22846 @deftp {Data Type} krb5-realm
22847 @cindex realm, kerberos
22850 This field is a string identifying the name of the realm.
22851 A common convention is to use the fully qualified DNS name of your organization,
22852 converted to upper case.
22854 @item @code{admin-server}
22855 This field is a string identifying the host where the administration server is
22859 This field is a string identifying the key distribution center
22864 @deftp {Data Type} krb5-configuration
22867 @item @code{allow-weak-crypto?} (default: @code{#f})
22868 If this flag is @code{#t} then services which only offer encryption algorithms
22869 known to be weak will be accepted.
22871 @item @code{default-realm} (default: @code{#f})
22872 This field should be a string identifying the default Kerberos
22873 realm for the client.
22874 You should set this field to the name of your Kerberos realm.
22875 If this value is @code{#f}
22876 then a realm must be specified with every Kerberos principal when invoking programs
22877 such as @command{kinit}.
22879 @item @code{realms}
22880 This should be a non-empty list of @code{krb5-realm} objects, which clients may
22882 Normally, one of them will have a @code{name} field matching the @code{default-realm}
22888 @subsubheading PAM krb5 Service
22891 The @code{pam-krb5} service allows for login authentication and password
22892 management via Kerberos.
22893 You will need this service if you want PAM enabled applications to authenticate
22894 users using Kerberos.
22896 @defvr {Scheme Variable} pam-krb5-service-type
22897 A service type for the Kerberos 5 PAM module.
22900 @deftp {Data Type} pam-krb5-configuration
22901 Data type representing the configuration of the Kerberos 5 PAM module.
22902 This type has the following parameters:
22904 @item @code{pam-krb5} (default: @code{pam-krb5})
22905 The pam-krb5 package to use.
22907 @item @code{minimum-uid} (default: @code{1000})
22908 The smallest user ID for which Kerberos authentications should be attempted.
22909 Local accounts with lower values will silently fail to authenticate.
22914 @node LDAP Services
22915 @subsection LDAP Services
22917 @cindex nslcd, LDAP service
22919 The @code{(gnu services authentication)} module provides the
22920 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
22921 server. In addition to configuring the service itself, you may want to add
22922 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
22923 Switch} for detailed information.
22925 Here is a simple operating system declaration with a default configuration of
22926 the @code{nslcd-service-type} and a Name Service Switch configuration that
22927 consults the @code{ldap} name service last:
22930 (use-service-modules authentication)
22931 (use-modules (gnu system nss))
22937 (service nslcd-service-type)
22938 (service dhcp-client-service-type)
22940 (name-service-switch
22941 (let ((services (list (name-service (name "db"))
22942 (name-service (name "files"))
22943 (name-service (name "ldap")))))
22944 (name-service-switch
22945 (inherit %mdns-host-lookup-nss)
22946 (password services)
22949 (netgroup services)
22950 (gshadow services)))))
22953 @c %start of generated documentation for nslcd-configuration
22955 Available @code{nslcd-configuration} fields are:
22957 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
22958 The @code{nss-pam-ldapd} package to use.
22962 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
22963 The number of threads to start that can handle requests and perform LDAP
22964 queries. Each thread opens a separate connection to the LDAP server.
22965 The default is to start 5 threads.
22967 Defaults to @samp{disabled}.
22971 @deftypevr {@code{nslcd-configuration} parameter} string uid
22972 This specifies the user id with which the daemon should be run.
22974 Defaults to @samp{"nslcd"}.
22978 @deftypevr {@code{nslcd-configuration} parameter} string gid
22979 This specifies the group id with which the daemon should be run.
22981 Defaults to @samp{"nslcd"}.
22985 @deftypevr {@code{nslcd-configuration} parameter} log-option log
22986 This option controls the way logging is done via a list containing
22987 SCHEME and LEVEL@. The SCHEME argument may either be the symbols
22988 @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
22989 argument is optional and specifies the log level. The log level may be
22990 one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
22991 @samp{notice}, @samp{info} or @samp{debug}. All messages with the
22992 specified log level or higher are logged.
22994 Defaults to @samp{("/var/log/nslcd" info)}.
22998 @deftypevr {@code{nslcd-configuration} parameter} list uri
22999 The list of LDAP server URIs. Normally, only the first server will be
23000 used with the following servers as fall-back.
23002 Defaults to @samp{("ldap://localhost:389/")}.
23006 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
23007 The version of the LDAP protocol to use. The default is to use the
23008 maximum version supported by the LDAP library.
23010 Defaults to @samp{disabled}.
23014 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
23015 Specifies the distinguished name with which to bind to the directory
23016 server for lookups. The default is to bind anonymously.
23018 Defaults to @samp{disabled}.
23022 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
23023 Specifies the credentials with which to bind. This option is only
23024 applicable when used with binddn.
23026 Defaults to @samp{disabled}.
23030 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
23031 Specifies the distinguished name to use when the root user tries to
23032 modify a user's password using the PAM module.
23034 Defaults to @samp{disabled}.
23038 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
23039 Specifies the credentials with which to bind if the root user tries to
23040 change a user's password. This option is only applicable when used with
23043 Defaults to @samp{disabled}.
23047 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
23048 Specifies the SASL mechanism to be used when performing SASL
23051 Defaults to @samp{disabled}.
23055 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
23056 Specifies the SASL realm to be used when performing SASL authentication.
23058 Defaults to @samp{disabled}.
23062 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
23063 Specifies the authentication identity to be used when performing SASL
23066 Defaults to @samp{disabled}.
23070 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
23071 Specifies the authorization identity to be used when performing SASL
23074 Defaults to @samp{disabled}.
23078 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
23079 Determines whether the LDAP server host name should be canonicalised. If
23080 this is enabled the LDAP library will do a reverse host name lookup. By
23081 default, it is left up to the LDAP library whether this check is
23084 Defaults to @samp{disabled}.
23088 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
23089 Set the name for the GSS-API Kerberos credentials cache.
23091 Defaults to @samp{disabled}.
23095 @deftypevr {@code{nslcd-configuration} parameter} string base
23096 The directory search base.
23098 Defaults to @samp{"dc=example,dc=com"}.
23102 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
23103 Specifies the search scope (subtree, onelevel, base or children). The
23104 default scope is subtree; base scope is almost never useful for name
23105 service lookups; children scope is not supported on all servers.
23107 Defaults to @samp{(subtree)}.
23111 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
23112 Specifies the policy for dereferencing aliases. The default policy is
23113 to never dereference aliases.
23115 Defaults to @samp{disabled}.
23119 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
23120 Specifies whether automatic referral chasing should be enabled. The
23121 default behaviour is to chase referrals.
23123 Defaults to @samp{disabled}.
23127 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
23128 This option allows for custom attributes to be looked up instead of the
23129 default RFC 2307 attributes. It is a list of maps, each consisting of
23130 the name of a map, the RFC 2307 attribute to match and the query
23131 expression for the attribute as it is available in the directory.
23133 Defaults to @samp{()}.
23137 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
23138 A list of filters consisting of the name of a map to which the filter
23139 applies and an LDAP search filter expression.
23141 Defaults to @samp{()}.
23145 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
23146 Specifies the time limit in seconds to use when connecting to the
23147 directory server. The default value is 10 seconds.
23149 Defaults to @samp{disabled}.
23153 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
23154 Specifies the time limit (in seconds) to wait for a response from the
23155 LDAP server. A value of zero, which is the default, is to wait
23156 indefinitely for searches to be completed.
23158 Defaults to @samp{disabled}.
23162 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
23163 Specifies the period if inactivity (in seconds) after which the con‐
23164 nection to the LDAP server will be closed. The default is not to time
23167 Defaults to @samp{disabled}.
23171 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
23172 Specifies the number of seconds to sleep when connecting to all LDAP
23173 servers fails. By default one second is waited between the first
23174 failure and the first retry.
23176 Defaults to @samp{disabled}.
23180 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
23181 Specifies the time after which the LDAP server is considered to be
23182 permanently unavailable. Once this time is reached retries will be done
23183 only once per this time period. The default value is 10 seconds.
23185 Defaults to @samp{disabled}.
23189 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
23190 Specifies whether to use SSL/TLS or not (the default is not to). If
23191 'start-tls is specified then StartTLS is used rather than raw LDAP over
23194 Defaults to @samp{disabled}.
23198 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
23199 Specifies what checks to perform on a server-supplied certificate. The
23200 meaning of the values is described in the ldap.conf(5) manual page.
23202 Defaults to @samp{disabled}.
23206 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
23207 Specifies the directory containing X.509 certificates for peer authen‐
23208 tication. This parameter is ignored when using GnuTLS.
23210 Defaults to @samp{disabled}.
23214 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
23215 Specifies the path to the X.509 certificate for peer authentication.
23217 Defaults to @samp{disabled}.
23221 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
23222 Specifies the path to an entropy source. This parameter is ignored when
23225 Defaults to @samp{disabled}.
23229 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
23230 Specifies the ciphers to use for TLS as a string.
23232 Defaults to @samp{disabled}.
23236 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
23237 Specifies the path to the file containing the local certificate for
23238 client TLS authentication.
23240 Defaults to @samp{disabled}.
23244 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
23245 Specifies the path to the file containing the private key for client TLS
23248 Defaults to @samp{disabled}.
23252 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
23253 Set this to a number greater than 0 to request paged results from the
23254 LDAP server in accordance with RFC2696. The default (0) is to not
23255 request paged results.
23257 Defaults to @samp{disabled}.
23261 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
23262 This option prevents group membership lookups through LDAP for the
23263 specified users. Alternatively, the value 'all-local may be used. With
23264 that value nslcd builds a full list of non-LDAP users on startup.
23266 Defaults to @samp{disabled}.
23270 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
23271 This option ensures that LDAP users with a numeric user id lower than
23272 the specified value are ignored.
23274 Defaults to @samp{disabled}.
23278 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
23279 This option specifies an offset that is added to all LDAP numeric user
23280 ids. This can be used to avoid user id collisions with local users.
23282 Defaults to @samp{disabled}.
23286 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
23287 This option specifies an offset that is added to all LDAP numeric group
23288 ids. This can be used to avoid user id collisions with local groups.
23290 Defaults to @samp{disabled}.
23294 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
23295 If this option is set, the member attribute of a group may point to
23296 another group. Members of nested groups are also returned in the higher
23297 level group and parent groups are returned when finding groups for a
23298 specific user. The default is not to perform extra searches for nested
23301 Defaults to @samp{disabled}.
23305 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
23306 If this option is set, the group member list is not retrieved when
23307 looking up groups. Lookups for finding which groups a user belongs to
23308 will remain functional so the user will likely still get the correct
23309 groups assigned on login.
23311 Defaults to @samp{disabled}.
23315 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
23316 If this option is set, functions which cause all user/group entries to
23317 be loaded from the directory will not succeed in doing so. This can
23318 dramatically reduce LDAP server load in situations where there are a
23319 great number of users and/or groups. This option is not recommended for
23320 most configurations.
23322 Defaults to @samp{disabled}.
23326 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
23327 This option can be used to specify how user and group names are verified
23328 within the system. This pattern is used to check all user and group
23329 names that are requested and returned from LDAP.
23331 Defaults to @samp{disabled}.
23335 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
23336 This specifies whether or not to perform searches using case-insensitive
23337 matching. Enabling this could open up the system to authorization
23338 bypass vulnerabilities and introduce nscd cache poisoning
23339 vulnerabilities which allow denial of service.
23341 Defaults to @samp{disabled}.
23345 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
23346 This option specifies whether password policy controls are requested and
23347 handled from the LDAP server when performing user authentication.
23349 Defaults to @samp{disabled}.
23353 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
23354 By default nslcd performs an LDAP search with the user's credentials
23355 after BIND (authentication) to ensure that the BIND operation was
23356 successful. The default search is a simple check to see if the user's
23357 DN exists. A search filter can be specified that will be used instead.
23358 It should return at least one entry.
23360 Defaults to @samp{disabled}.
23364 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
23365 This option allows flexible fine tuning of the authorisation check that
23366 should be performed. The search filter specified is executed and if any
23367 entries match, access is granted, otherwise access is denied.
23369 Defaults to @samp{disabled}.
23373 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
23374 If this option is set password modification using pam_ldap will be
23375 denied and the specified message will be presented to the user instead.
23376 The message can be used to direct the user to an alternative means of
23377 changing their password.
23379 Defaults to @samp{disabled}.
23383 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
23384 List of pam service names for which LDAP authentication should suffice.
23386 Defaults to @samp{()}.
23390 @c %end of generated documentation for nslcd-configuration
23394 @subsection Web Services
23399 The @code{(gnu services web)} module provides the Apache HTTP Server,
23400 the nginx web server, and also a fastcgi wrapper daemon.
23402 @subsubheading Apache HTTP Server
23404 @deffn {Scheme Variable} httpd-service-type
23405 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
23406 (@dfn{httpd}). The value for this service type is a
23407 @code{httpd-configuration} record.
23409 A simple example configuration is given below.
23412 (service httpd-service-type
23413 (httpd-configuration
23416 (server-name "www.example.com")
23417 (document-root "/srv/http/www.example.com")))))
23420 Other services can also extend the @code{httpd-service-type} to add to
23424 (simple-service 'www.example.com-server httpd-service-type
23428 (list (string-join '("ServerName www.example.com"
23429 "DocumentRoot /srv/http/www.example.com")
23434 The details for the @code{httpd-configuration}, @code{httpd-module},
23435 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
23438 @deffn {Data Type} httpd-configuration
23439 This data type represents the configuration for the httpd service.
23442 @item @code{package} (default: @code{httpd})
23443 The httpd package to use.
23445 @item @code{pid-file} (default: @code{"/var/run/httpd"})
23446 The pid file used by the shepherd-service.
23448 @item @code{config} (default: @code{(httpd-config-file)})
23449 The configuration file to use with the httpd service. The default value
23450 is a @code{httpd-config-file} record, but this can also be a different
23451 G-expression that generates a file, for example a @code{plain-file}. A
23452 file outside of the store can also be specified through a string.
23457 @deffn {Data Type} httpd-module
23458 This data type represents a module for the httpd service.
23462 The name of the module.
23465 The file for the module. This can be relative to the httpd package being
23466 used, the absolute location of a file, or a G-expression for a file
23467 within the store, for example @code{(file-append mod-wsgi
23468 "/modules/mod_wsgi.so")}.
23473 @defvr {Scheme Variable} %default-httpd-modules
23474 A default list of @code{httpd-module} objects.
23477 @deffn {Data Type} httpd-config-file
23478 This data type represents a configuration file for the httpd service.
23481 @item @code{modules} (default: @code{%default-httpd-modules})
23482 The modules to load. Additional modules can be added here, or loaded by
23483 additional configuration.
23485 For example, in order to handle requests for PHP files, you can use Apache’s
23486 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
23489 (service httpd-service-type
23490 (httpd-configuration
23495 (name "proxy_module")
23496 (file "modules/mod_proxy.so"))
23498 (name "proxy_fcgi_module")
23499 (file "modules/mod_proxy_fcgi.so"))
23500 %default-httpd-modules))
23501 (extra-config (list "\
23502 <FilesMatch \\.php$>
23503 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
23504 </FilesMatch>"))))))
23505 (service php-fpm-service-type
23506 (php-fpm-configuration
23507 (socket "/var/run/php-fpm.sock")
23508 (socket-group "httpd")))
23511 @item @code{server-root} (default: @code{httpd})
23512 The @code{ServerRoot} in the configuration file, defaults to the httpd
23513 package. Directives including @code{Include} and @code{LoadModule} are
23514 taken as relative to the server root.
23516 @item @code{server-name} (default: @code{#f})
23517 The @code{ServerName} in the configuration file, used to specify the
23518 request scheme, hostname and port that the server uses to identify
23521 This doesn't need to be set in the server config, and can be specified
23522 in virtual hosts. The default is @code{#f} to not specify a
23525 @item @code{document-root} (default: @code{"/srv/http"})
23526 The @code{DocumentRoot} from which files will be served.
23528 @item @code{listen} (default: @code{'("80")})
23529 The list of values for the @code{Listen} directives in the config
23530 file. The value should be a list of strings, when each string can
23531 specify the port number to listen on, and optionally the IP address and
23534 @item @code{pid-file} (default: @code{"/var/run/httpd"})
23535 The @code{PidFile} to use. This should match the @code{pid-file} set in
23536 the @code{httpd-configuration} so that the Shepherd service is
23537 configured correctly.
23539 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
23540 The @code{ErrorLog} to which the server will log errors.
23542 @item @code{user} (default: @code{"httpd"})
23543 The @code{User} which the server will answer requests as.
23545 @item @code{group} (default: @code{"httpd"})
23546 The @code{Group} which the server will answer requests as.
23548 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
23549 A flat list of strings and G-expressions which will be added to the end
23550 of the configuration file.
23552 Any values which the service is extended with will be appended to this
23558 @deffn {Data Type} httpd-virtualhost
23559 This data type represents a virtualhost configuration block for the httpd service.
23561 These should be added to the extra-config for the httpd-service.
23564 (simple-service 'www.example.com-server httpd-service-type
23568 (list (string-join '("ServerName www.example.com"
23569 "DocumentRoot /srv/http/www.example.com")
23574 @item @code{addresses-and-ports}
23575 The addresses and ports for the @code{VirtualHost} directive.
23577 @item @code{contents}
23578 The contents of the @code{VirtualHost} directive, this should be a list
23579 of strings and G-expressions.
23584 @subsubheading NGINX
23586 @deffn {Scheme Variable} nginx-service-type
23587 Service type for the @uref{https://nginx.org/,NGinx} web server. The
23588 value for this service type is a @code{<nginx-configuration>} record.
23590 A simple example configuration is given below.
23593 (service nginx-service-type
23594 (nginx-configuration
23596 (list (nginx-server-configuration
23597 (server-name '("www.example.com"))
23598 (root "/srv/http/www.example.com"))))))
23601 In addition to adding server blocks to the service configuration
23602 directly, this service can be extended by other services to add server
23603 blocks, as in this example:
23606 (simple-service 'my-extra-server nginx-service-type
23607 (list (nginx-server-configuration
23608 (root "/srv/http/extra-website")
23609 (try-files (list "$uri" "$uri/index.html")))))
23613 At startup, @command{nginx} has not yet read its configuration file, so
23614 it uses a default file to log error messages. If it fails to load its
23615 configuration file, that is where error messages are logged. After the
23616 configuration file is loaded, the default error log file changes as per
23617 configuration. In our case, startup error messages can be found in
23618 @file{/var/run/nginx/logs/error.log}, and after configuration in
23619 @file{/var/log/nginx/error.log}. The second location can be changed
23620 with the @var{log-directory} configuration option.
23622 @deffn {Data Type} nginx-configuration
23623 This data type represents the configuration for NGinx. Some
23624 configuration can be done through this and the other provided record
23625 types, or alternatively, a config file can be provided.
23628 @item @code{nginx} (default: @code{nginx})
23629 The nginx package to use.
23631 @item @code{log-directory} (default: @code{"/var/log/nginx"})
23632 The directory to which NGinx will write log files.
23634 @item @code{run-directory} (default: @code{"/var/run/nginx"})
23635 The directory in which NGinx will create a pid file, and write temporary
23638 @item @code{server-blocks} (default: @code{'()})
23639 A list of @dfn{server blocks} to create in the generated configuration
23640 file, the elements should be of type
23641 @code{<nginx-server-configuration>}.
23643 The following example would setup NGinx to serve @code{www.example.com}
23644 from the @code{/srv/http/www.example.com} directory, without using
23647 (service nginx-service-type
23648 (nginx-configuration
23650 (list (nginx-server-configuration
23651 (server-name '("www.example.com"))
23652 (root "/srv/http/www.example.com"))))))
23655 @item @code{upstream-blocks} (default: @code{'()})
23656 A list of @dfn{upstream blocks} to create in the generated configuration
23657 file, the elements should be of type
23658 @code{<nginx-upstream-configuration>}.
23660 Configuring upstreams through the @code{upstream-blocks} can be useful
23661 when combined with @code{locations} in the
23662 @code{<nginx-server-configuration>} records. The following example
23663 creates a server configuration with one location configuration, that
23664 will proxy requests to a upstream configuration, which will handle
23665 requests with two servers.
23670 (nginx-configuration
23672 (list (nginx-server-configuration
23673 (server-name '("www.example.com"))
23674 (root "/srv/http/www.example.com")
23677 (nginx-location-configuration
23679 (body '("proxy_pass http://server-proxy;"))))))))
23681 (list (nginx-upstream-configuration
23682 (name "server-proxy")
23683 (servers (list "server1.example.com"
23684 "server2.example.com")))))))
23687 @item @code{file} (default: @code{#f})
23688 If a configuration @var{file} is provided, this will be used, rather than
23689 generating a configuration file from the provided @code{log-directory},
23690 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
23691 proper operation, these arguments should match what is in @var{file} to ensure
23692 that the directories are created when the service is activated.
23694 This can be useful if you have an existing configuration file, or it's
23695 not possible to do what is required through the other parts of the
23696 nginx-configuration record.
23698 @item @code{server-names-hash-bucket-size} (default: @code{#f})
23699 Bucket size for the server names hash tables, defaults to @code{#f} to
23700 use the size of the processors cache line.
23702 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
23703 Maximum bucket size for the server names hash tables.
23705 @item @code{modules} (default: @code{'()})
23706 List of nginx dynamic modules to load. This should be a list of file
23707 names of loadable modules, as in this example:
23712 (file-append nginx-accept-language-module "\
23713 /etc/nginx/modules/ngx_http_accept_language_module.so")
23714 (file-append nginx-lua-module "\
23715 /etc/nginx/modules/ngx_http_lua_module.so")))
23718 @item @code{lua-package-path} (default: @code{'()})
23719 List of nginx lua packages to load. This should be a list of package
23720 names of loadable lua modules, as in this example:
23723 (lua-package-path (list lua-resty-core
23730 @item @code{lua-package-cpath} (default: @code{'()})
23731 List of nginx lua C packages to load. This should be a list of package
23732 names of loadable lua C modules, as in this example:
23735 (lua-package-cpath (list lua-resty-signal))
23738 @item @code{global-directives} (default: @code{'((events . ()))})
23739 Association list of global directives for the top level of the nginx
23740 configuration. Values may themselves be association lists.
23744 `((worker_processes . 16)
23746 (events . ((worker_connections . 1024)))))
23749 @item @code{extra-content} (default: @code{""})
23750 Extra content for the @code{http} block. Should be string or a string
23751 valued G-expression.
23756 @deftp {Data Type} nginx-server-configuration
23757 Data type representing the configuration of an nginx server block.
23758 This type has the following parameters:
23761 @item @code{listen} (default: @code{'("80" "443 ssl")})
23762 Each @code{listen} directive sets the address and port for IP, or the
23763 path for a UNIX-domain socket on which the server will accept requests.
23764 Both address and port, or only address or only port can be specified.
23765 An address may also be a hostname, for example:
23768 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
23771 @item @code{server-name} (default: @code{(list 'default)})
23772 A list of server names this server represents. @code{'default} represents the
23773 default server for connections matching no other server.
23775 @item @code{root} (default: @code{"/srv/http"})
23776 Root of the website nginx will serve.
23778 @item @code{locations} (default: @code{'()})
23779 A list of @dfn{nginx-location-configuration} or
23780 @dfn{nginx-named-location-configuration} records to use within this
23783 @item @code{index} (default: @code{(list "index.html")})
23784 Index files to look for when clients ask for a directory. If it cannot be found,
23785 Nginx will send the list of files in the directory.
23787 @item @code{try-files} (default: @code{'()})
23788 A list of files whose existence is checked in the specified order.
23789 @code{nginx} will use the first file it finds to process the request.
23791 @item @code{ssl-certificate} (default: @code{#f})
23792 Where to find the certificate for secure connections. Set it to @code{#f} if
23793 you don't have a certificate or you don't want to use HTTPS.
23795 @item @code{ssl-certificate-key} (default: @code{#f})
23796 Where to find the private key for secure connections. Set it to @code{#f} if
23797 you don't have a key or you don't want to use HTTPS.
23799 @item @code{server-tokens?} (default: @code{#f})
23800 Whether the server should add its configuration to response.
23802 @item @code{raw-content} (default: @code{'()})
23803 A list of raw lines added to the server block.
23808 @deftp {Data Type} nginx-upstream-configuration
23809 Data type representing the configuration of an nginx @code{upstream}
23810 block. This type has the following parameters:
23814 Name for this group of servers.
23816 @item @code{servers}
23817 Specify the addresses of the servers in the group. The address can be
23818 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
23819 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
23820 prefix @samp{unix:}. For addresses using an IP address or domain name,
23821 the default port is 80, and a different port can be specified
23827 @deftp {Data Type} nginx-location-configuration
23828 Data type representing the configuration of an nginx @code{location}
23829 block. This type has the following parameters:
23833 URI which this location block matches.
23835 @anchor{nginx-location-configuration body}
23837 Body of the location block, specified as a list of strings. This can contain
23839 configuration directives. For example, to pass requests to a upstream
23840 server group defined using an @code{nginx-upstream-configuration} block,
23841 the following directive would be specified in the body @samp{(list "proxy_pass
23842 http://upstream-name;")}.
23847 @deftp {Data Type} nginx-named-location-configuration
23848 Data type representing the configuration of an nginx named location
23849 block. Named location blocks are used for request redirection, and not
23850 used for regular request processing. This type has the following
23855 Name to identify this location block.
23858 @xref{nginx-location-configuration body}, as the body for named location
23859 blocks can be used in a similar way to the
23860 @code{nginx-location-configuration body}. One restriction is that the
23861 body of a named location block cannot contain location blocks.
23866 @subsubheading Varnish Cache
23868 Varnish is a fast cache server that sits in between web applications
23869 and end users. It proxies requests from clients and caches the
23870 accessed URLs such that multiple requests for the same resource only
23871 creates one request to the back-end.
23873 @defvr {Scheme Variable} varnish-service-type
23874 Service type for the Varnish daemon.
23877 @deftp {Data Type} varnish-configuration
23878 Data type representing the @code{varnish} service configuration.
23879 This type has the following parameters:
23882 @item @code{package} (default: @code{varnish})
23883 The Varnish package to use.
23885 @item @code{name} (default: @code{"default"})
23886 A name for this Varnish instance. Varnish will create a directory in
23887 @file{/var/varnish/} with this name and keep temporary files there. If
23888 the name starts with a forward slash, it is interpreted as an absolute
23891 Pass the @code{-n} argument to other Varnish programs to connect to the
23892 named instance, e.g.@: @command{varnishncsa -n default}.
23894 @item @code{backend} (default: @code{"localhost:8080"})
23895 The backend to use. This option has no effect if @code{vcl} is set.
23897 @item @code{vcl} (default: #f)
23898 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
23899 is @code{#f}, Varnish will proxy @code{backend} using the default
23900 configuration. Otherwise this must be a file-like object with valid
23903 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
23904 For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
23905 can do something along these lines:
23908 (define %gnu-mirror
23909 (plain-file "gnu.vcl"
23911 backend gnu @{ .host = \"www.gnu.org\"; @}"))
23915 (services (cons (service varnish-service-type
23916 (varnish-configuration
23918 (vcl %gnu-mirror)))
23922 The configuration of an already running Varnish instance can be inspected
23923 and changed using the @command{varnishadm} program.
23925 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
23926 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
23927 comprehensive documentation on Varnish and its configuration language.
23929 @item @code{listen} (default: @code{'("localhost:80")})
23930 List of addresses Varnish will listen on.
23932 @item @code{storage} (default: @code{'("malloc,128m")})
23933 List of storage backends that will be available in VCL.
23935 @item @code{parameters} (default: @code{'()})
23936 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
23938 @item @code{extra-options} (default: @code{'()})
23939 Additional arguments to pass to the @command{varnishd} process.
23944 @subsubheading Patchwork
23946 Patchwork is a patch tracking system. It can collect patches sent to a
23947 mailing list, and display them in a web interface.
23949 @defvr {Scheme Variable} patchwork-service-type
23950 Service type for Patchwork.
23953 The following example is an example of a minimal service for Patchwork, for
23954 the @code{patchwork.example.com} domain.
23957 (service patchwork-service-type
23958 (patchwork-configuration
23959 (domain "patchwork.example.com")
23961 (patchwork-settings-module
23962 (allowed-hosts (list domain))
23963 (default-from-email "patchwork@@patchwork.example.com")))
23964 (getmail-retriever-config
23965 (getmail-retriever-configuration
23966 (type "SimpleIMAPSSLRetriever")
23967 (server "imap.example.com")
23969 (username "patchwork")
23971 (list (file-append coreutils "/bin/cat")
23972 "/etc/getmail-patchwork-imap-password"))
23974 '((mailboxes . ("Patches"))))))))
23978 There are three records for configuring the Patchwork service. The
23979 @code{<patchwork-configuration>} relates to the configuration for Patchwork
23980 within the HTTPD service.
23982 The @code{settings-module} field within the @code{<patchwork-configuration>}
23983 record can be populated with the @code{<patchwork-settings-module>} record,
23984 which describes a settings module that is generated within the Guix store.
23986 For the @code{database-configuration} field within the
23987 @code{<patchwork-settings-module>}, the
23988 @code{<patchwork-database-configuration>} must be used.
23990 @deftp {Data Type} patchwork-configuration
23991 Data type representing the Patchwork service configuration. This type has the
23992 following parameters:
23995 @item @code{patchwork} (default: @code{patchwork})
23996 The Patchwork package to use.
23998 @item @code{domain}
23999 The domain to use for Patchwork, this is used in the HTTPD service virtual
24002 @item @code{settings-module}
24003 The settings module to use for Patchwork. As a Django application, Patchwork
24004 is configured with a Python module containing the settings. This can either be
24005 an instance of the @code{<patchwork-settings-module>} record, any other record
24006 that represents the settings in the store, or a directory outside of the
24009 @item @code{static-path} (default: @code{"/static/"})
24010 The path under which the HTTPD service should serve the static files.
24012 @item @code{getmail-retriever-config}
24013 The getmail-retriever-configuration record value to use with
24014 Patchwork. Getmail will be configured with this value, the messages will be
24015 delivered to Patchwork.
24020 @deftp {Data Type} patchwork-settings-module
24021 Data type representing a settings module for Patchwork. Some of these
24022 settings relate directly to Patchwork, but others relate to Django, the web
24023 framework used by Patchwork, or the Django Rest Framework library. This type
24024 has the following parameters:
24027 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
24028 The database connection settings used for Patchwork. See the
24029 @code{<patchwork-database-configuration>} record type for more information.
24031 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
24032 Patchwork, as a Django web application uses a secret key for cryptographically
24033 signing values. This file should contain a unique unpredictable value.
24035 If this file does not exist, it will be created and populated with a random
24036 value by the patchwork-setup shepherd service.
24038 This setting relates to Django.
24040 @item @code{allowed-hosts}
24041 A list of valid hosts for this Patchwork service. This should at least include
24042 the domain specified in the @code{<patchwork-configuration>} record.
24044 This is a Django setting.
24046 @item @code{default-from-email}
24047 The email address from which Patchwork should send email by default.
24049 This is a Patchwork setting.
24051 @item @code{static-url} (default: @code{#f})
24052 The URL to use when serving static assets. It can be part of a URL, or a full
24053 URL, but must end in a @code{/}.
24055 If the default value is used, the @code{static-path} value from the
24056 @code{<patchwork-configuration>} record will be used.
24058 This is a Django setting.
24060 @item @code{admins} (default: @code{'()})
24061 Email addresses to send the details of errors that occur. Each value should
24062 be a list containing two elements, the name and then the email address.
24064 This is a Django setting.
24066 @item @code{debug?} (default: @code{#f})
24067 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
24068 messages will be shown.
24070 This is a Django setting.
24072 @item @code{enable-rest-api?} (default: @code{#t})
24073 Whether to enable the Patchwork REST API.
24075 This is a Patchwork setting.
24077 @item @code{enable-xmlrpc?} (default: @code{#t})
24078 Whether to enable the XML RPC API.
24080 This is a Patchwork setting.
24082 @item @code{force-https-links?} (default: @code{#t})
24083 Whether to use HTTPS links on Patchwork pages.
24085 This is a Patchwork setting.
24087 @item @code{extra-settings} (default: @code{""})
24088 Extra code to place at the end of the Patchwork settings module.
24093 @deftp {Data Type} patchwork-database-configuration
24094 Data type representing the database configuration for Patchwork.
24097 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
24098 The database engine to use.
24100 @item @code{name} (default: @code{"patchwork"})
24101 The name of the database to use.
24103 @item @code{user} (default: @code{"httpd"})
24104 The user to connect to the database as.
24106 @item @code{password} (default: @code{""})
24107 The password to use when connecting to the database.
24109 @item @code{host} (default: @code{""})
24110 The host to make the database connection to.
24112 @item @code{port} (default: @code{""})
24113 The port on which to connect to the database.
24118 @subsubheading Mumi
24120 @cindex Mumi, Debbugs Web interface
24121 @cindex Debbugs, Mumi Web interface
24122 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
24123 Web interface to the Debbugs bug tracker, by default for
24124 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
24125 but it also fetches and indexes mail retrieved from Debbugs.
24127 @defvr {Scheme Variable} mumi-service-type
24128 This is the service type for Mumi.
24131 @deftp {Data Type} mumi-configuration
24132 Data type representing the Mumi service configuration. This type has the
24136 @item @code{mumi} (default: @code{mumi})
24137 The Mumi package to use.
24139 @item @code{mailer?} (default: @code{#true})
24140 Whether to enable or disable the mailer component.
24142 @item @code{mumi-configuration-sender}
24143 The email address used as the sender for comments.
24145 @item @code{mumi-configuration-smtp}
24146 A URI to configure the SMTP settings for Mailutils. This could be
24147 something like @code{sendmail:///path/to/bin/msmtp} or any other URI
24148 supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
24149 mailutils, GNU@tie{}Mailutils}.
24155 @subsubheading FastCGI
24158 FastCGI is an interface between the front-end and the back-end of a web
24159 service. It is a somewhat legacy facility; new web services should
24160 generally just talk HTTP between the front-end and the back-end.
24161 However there are a number of back-end services such as PHP or the
24162 optimized HTTP Git repository access that use FastCGI, so we have
24163 support for it in Guix.
24165 To use FastCGI, you configure the front-end web server (e.g., nginx) to
24166 dispatch some subset of its requests to the fastcgi backend, which
24167 listens on a local TCP or UNIX socket. There is an intermediary
24168 @code{fcgiwrap} program that sits between the actual backend process and
24169 the web server. The front-end indicates which backend program to run,
24170 passing that information to the @code{fcgiwrap} process.
24172 @defvr {Scheme Variable} fcgiwrap-service-type
24173 A service type for the @code{fcgiwrap} FastCGI proxy.
24176 @deftp {Data Type} fcgiwrap-configuration
24177 Data type representing the configuration of the @code{fcgiwrap} service.
24178 This type has the following parameters:
24180 @item @code{package} (default: @code{fcgiwrap})
24181 The fcgiwrap package to use.
24183 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
24184 The socket on which the @code{fcgiwrap} process should listen, as a
24185 string. Valid @var{socket} values include
24186 @code{unix:@var{/path/to/unix/socket}},
24187 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
24188 @code{tcp6:[@var{ipv6_addr}]:port}.
24190 @item @code{user} (default: @code{fcgiwrap})
24191 @itemx @code{group} (default: @code{fcgiwrap})
24192 The user and group names, as strings, under which to run the
24193 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
24194 the user asks for the specific user or group names @code{fcgiwrap} that
24195 the corresponding user and/or group is present on the system.
24197 It is possible to configure a FastCGI-backed web service to pass HTTP
24198 authentication information from the front-end to the back-end, and to
24199 allow @code{fcgiwrap} to run the back-end process as a corresponding
24200 local user. To enable this capability on the back-end, run
24201 @code{fcgiwrap} as the @code{root} user and group. Note that this
24202 capability also has to be configured on the front-end as well.
24207 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
24208 with some additional features useful for sites of any size.
24210 These features include:
24212 @item Adaptive process spawning
24213 @item Basic statistics (similar to Apache's mod_status)
24214 @item Advanced process management with graceful stop/start
24215 @item Ability to start workers with different uid/gid/chroot/environment
24216 and different php.ini (replaces safe_mode)
24217 @item Stdout & stderr logging
24218 @item Emergency restart in case of accidental opcode cache destruction
24219 @item Accelerated upload support
24220 @item Support for a "slowlog"
24221 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
24222 a special function to finish request & flush all data while continuing to do
24223 something time-consuming (video converting, stats processing, etc.)
24225 ...@: and much more.
24227 @defvr {Scheme Variable} php-fpm-service-type
24228 A Service type for @code{php-fpm}.
24231 @deftp {Data Type} php-fpm-configuration
24232 Data Type for php-fpm service configuration.
24234 @item @code{php} (default: @code{php})
24235 The php package to use.
24236 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
24237 The address on which to accept FastCGI requests. Valid syntaxes are:
24239 @item @code{"ip.add.re.ss:port"}
24240 Listen on a TCP socket to a specific address on a specific port.
24241 @item @code{"port"}
24242 Listen on a TCP socket to all addresses on a specific port.
24243 @item @code{"/path/to/unix/socket"}
24244 Listen on a unix socket.
24247 @item @code{user} (default: @code{php-fpm})
24248 User who will own the php worker processes.
24249 @item @code{group} (default: @code{php-fpm})
24250 Group of the worker processes.
24251 @item @code{socket-user} (default: @code{php-fpm})
24252 User who can speak to the php-fpm socket.
24253 @item @code{socket-group} (default: @code{nginx})
24254 Group that can speak to the php-fpm socket.
24255 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
24256 The process id of the php-fpm process is written to this file
24257 once the service has started.
24258 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
24259 Log for the php-fpm master process.
24260 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
24261 Detailed settings for the php-fpm process manager.
24264 @item @code{<php-fpm-dynamic-process-manager-configuration>}
24265 @item @code{<php-fpm-static-process-manager-configuration>}
24266 @item @code{<php-fpm-on-demand-process-manager-configuration>}
24268 @item @code{display-errors} (default @code{#f})
24269 Determines whether php errors and warning should be sent to clients
24270 and displayed in their browsers.
24271 This is useful for local php development, but a security risk for public sites,
24272 as error messages can reveal passwords and personal data.
24273 @item @code{timezone} (default @code{#f})
24274 Specifies @code{php_admin_value[date.timezone]} parameter.
24275 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
24276 This file will log the @code{stderr} outputs of php worker processes.
24277 Can be set to @code{#f} to disable logging.
24278 @item @code{file} (default @code{#f})
24279 An optional override of the whole configuration.
24280 You can use the @code{mixed-text-file} function or an absolute filepath for it.
24281 @item @code{php-ini-file} (default @code{#f})
24282 An optional override of the default php settings.
24283 It may be any ``file-like'' object (@pxref{G-Expressions, file-like objects}).
24284 You can use the @code{mixed-text-file} function or an absolute filepath for it.
24286 For local development it is useful to set a higher timeout and memory
24287 limit for spawned php processes. This be accomplished with the
24288 following operating system configuration snippet:
24290 (define %local-php-ini
24291 (plain-file "php.ini"
24293 max_execution_time = 1800"))
24297 (services (cons (service php-fpm-service-type
24298 (php-fpm-configuration
24299 (php-ini-file %local-php-ini)))
24303 Consult the @url{https://www.php.net/manual/en/ini.core.php,core php.ini
24304 directives} for comprehensive documentation on the acceptable
24305 @file{php.ini} directives.
24309 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
24310 Data Type for the @code{dynamic} php-fpm process manager. With the
24311 @code{dynamic} process manager, spare worker processes are kept around
24312 based on it's configured limits.
24314 @item @code{max-children} (default: @code{5})
24315 Maximum of worker processes.
24316 @item @code{start-servers} (default: @code{2})
24317 How many worker processes should be started on start-up.
24318 @item @code{min-spare-servers} (default: @code{1})
24319 How many spare worker processes should be kept around at minimum.
24320 @item @code{max-spare-servers} (default: @code{3})
24321 How many spare worker processes should be kept around at maximum.
24325 @deftp {Data type} php-fpm-static-process-manager-configuration
24326 Data Type for the @code{static} php-fpm process manager. With the
24327 @code{static} process manager, an unchanging number of worker processes
24330 @item @code{max-children} (default: @code{5})
24331 Maximum of worker processes.
24335 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
24336 Data Type for the @code{on-demand} php-fpm process manager. With the
24337 @code{on-demand} process manager, worker processes are only created as
24340 @item @code{max-children} (default: @code{5})
24341 Maximum of worker processes.
24342 @item @code{process-idle-timeout} (default: @code{10})
24343 The time in seconds after which a process with no requests is killed.
24348 @deffn {Scheme Procedure} nginx-php-location @
24349 [#:nginx-package nginx] @
24350 [socket (string-append "/var/run/php" @
24351 (version-major (package-version php)) @
24353 A helper function to quickly add php to an @code{nginx-server-configuration}.
24356 A simple services setup for nginx with php can look like this:
24358 (services (cons* (service dhcp-client-service-type)
24359 (service php-fpm-service-type)
24360 (service nginx-service-type
24361 (nginx-server-configuration
24362 (server-name '("example.com"))
24363 (root "/srv/http/")
24365 (list (nginx-php-location)))
24367 (ssl-certificate #f)
24368 (ssl-certificate-key #f)))
24372 @cindex cat-avatar-generator
24373 The cat avatar generator is a simple service to demonstrate the use of php-fpm
24374 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
24375 the hash of a user's email address.
24377 @deffn {Scheme Procedure} cat-avatar-generator-service @
24378 [#:cache-dir "/var/cache/cat-avatar-generator"] @
24379 [#:package cat-avatar-generator] @
24380 [#:configuration (nginx-server-configuration)]
24381 Returns an nginx-server-configuration that inherits @code{configuration}. It
24382 extends the nginx configuration to add a server block that serves @code{package},
24383 a version of cat-avatar-generator. During execution, cat-avatar-generator will
24384 be able to use @code{cache-dir} as its cache directory.
24387 A simple setup for cat-avatar-generator can look like this:
24389 (services (cons* (cat-avatar-generator-service
24391 (nginx-server-configuration
24392 (server-name '("example.com"))))
24397 @subsubheading Hpcguix-web
24399 @cindex hpcguix-web
24400 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
24401 program is a customizable web interface to browse Guix packages,
24402 initially designed for users of high-performance computing (HPC)
24405 @defvr {Scheme Variable} hpcguix-web-service-type
24406 The service type for @code{hpcguix-web}.
24409 @deftp {Data Type} hpcguix-web-configuration
24410 Data type for the hpcguix-web service configuration.
24414 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
24415 configuration. The main items available in this spec are:
24418 @item @code{title-prefix} (default: @code{"hpcguix | "})
24419 The page title prefix.
24421 @item @code{guix-command} (default: @code{"guix"})
24422 The @command{guix} command.
24424 @item @code{package-filter-proc} (default: @code{(const #t)})
24425 A procedure specifying how to filter packages that are displayed.
24427 @item @code{package-page-extension-proc} (default: @code{(const '())})
24428 Extension package for @code{hpcguix-web}.
24430 @item @code{menu} (default: @code{'()})
24431 Additional entry in page @code{menu}.
24433 @item @code{channels} (default: @code{%default-channels})
24434 List of channels from which the package list is built (@pxref{Channels}).
24436 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
24437 The expiration time, in seconds, after which the package list is rebuilt from
24438 the latest instances of the given channels.
24441 See the hpcguix-web repository for a
24442 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
24445 @item @code{package} (default: @code{hpcguix-web})
24446 The hpcguix-web package to use.
24450 A typical hpcguix-web service declaration looks like this:
24453 (service hpcguix-web-service-type
24454 (hpcguix-web-configuration
24456 #~(define site-config
24457 (hpcweb-configuration
24458 (title-prefix "Guix-HPC - ")
24459 (menu '(("/about" "ABOUT"))))))))
24463 The hpcguix-web service periodically updates the package list it publishes by
24464 pulling channels from Git. To that end, it needs to access X.509 certificates
24465 so that it can authenticate Git servers when communicating over HTTPS, and it
24466 assumes that @file{/etc/ssl/certs} contains those certificates.
24468 Thus, make sure to add @code{nss-certs} or another certificate package to the
24469 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
24470 more information on X.509 certificates.
24473 @subsubheading gmnisrv
24476 The @uref{https://git.sr.ht/~sircmpwn/gmnisrv, gmnisrv} program is a
24477 simple @uref{https://gemini.circumlunar.space/, Gemini} protocol server.
24479 @deffn {Scheme Variable} gmnisrv-service-type
24480 This is the type of the gmnisrv service, whose value should be a
24481 @code{gmnisrv-configuration} object, as in this example:
24484 (service gmnisrv-service-type
24485 (gmnisrv-configuration
24486 (config-file (local-file "./my-gmnisrv.ini"))))
24490 @deftp {Data Type} gmnisrv-configuration
24491 Data type representing the configuration of gmnisrv.
24494 @item @code{package} (default: @var{gmnisrv})
24495 Package object of the gmnisrv server.
24497 @item @code{config-file} (default: @code{%default-gmnisrv-config-file})
24498 File-like object of the gmnisrv configuration file to use. The default
24499 configuration listens on port 1965 and serves files from
24500 @file{/srv/gemini}. Certificates are stored in
24501 @file{/var/lib/gemini/certs}. For more information, run @command{man
24502 gmnisrv} and @command{man gmnisrv.ini}.
24507 @node Certificate Services
24508 @subsection Certificate Services
24511 @cindex HTTP, HTTPS
24512 @cindex Let's Encrypt
24513 @cindex TLS certificates
24514 The @code{(gnu services certbot)} module provides a service to
24515 automatically obtain a valid TLS certificate from the Let's Encrypt
24516 certificate authority. These certificates can then be used to serve
24517 content securely over HTTPS or other TLS-based protocols, with the
24518 knowledge that the client will be able to verify the server's
24521 @url{https://letsencrypt.org/, Let's Encrypt} provides the
24522 @code{certbot} tool to automate the certification process. This tool
24523 first securely generates a key on the server. It then makes a request
24524 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
24525 checks that the request originates from the host in question by using a
24526 challenge-response protocol, requiring the server to provide its
24527 response over HTTP@. If that protocol completes successfully, the CA
24528 signs the key, resulting in a certificate. That certificate is valid
24529 for a limited period of time, and therefore to continue to provide TLS
24530 services, the server needs to periodically ask the CA to renew its
24533 The certbot service automates this process: the initial key
24534 generation, the initial certification request to the Let's Encrypt
24535 service, the web server challenge/response integration, writing the
24536 certificate to disk, the automated periodic renewals, and the deployment
24537 tasks associated with the renewal (e.g.@: reloading services, copying keys
24538 with different permissions).
24540 Certbot is run twice a day, at a random minute within the hour. It
24541 won't do anything until your certificates are due for renewal or
24542 revoked, but running it regularly would give your service a chance of
24543 staying online in case a Let's Encrypt-initiated revocation happened for
24546 By using this service, you agree to the ACME Subscriber Agreement, which
24547 can be found there:
24548 @url{https://acme-v01.api.letsencrypt.org/directory}.
24550 @defvr {Scheme Variable} certbot-service-type
24551 A service type for the @code{certbot} Let's Encrypt client. Its value
24552 must be a @code{certbot-configuration} record as in this example:
24555 (define %nginx-deploy-hook
24557 "nginx-deploy-hook"
24558 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
24559 (kill pid SIGHUP))))
24561 (service certbot-service-type
24562 (certbot-configuration
24563 (email "foo@@example.net")
24566 (certificate-configuration
24567 (domains '("example.net" "www.example.net"))
24568 (deploy-hook %nginx-deploy-hook))
24569 (certificate-configuration
24570 (domains '("bar.example.net")))))))
24573 See below for details about @code{certbot-configuration}.
24576 @deftp {Data Type} certbot-configuration
24577 Data type representing the configuration of the @code{certbot} service.
24578 This type has the following parameters:
24581 @item @code{package} (default: @code{certbot})
24582 The certbot package to use.
24584 @item @code{webroot} (default: @code{/var/www})
24585 The directory from which to serve the Let's Encrypt challenge/response
24588 @item @code{certificates} (default: @code{()})
24589 A list of @code{certificates-configuration}s for which to generate
24590 certificates and request signatures. Each certificate has a @code{name}
24591 and several @code{domains}.
24593 @item @code{email} (default: @code{#f})
24594 Optional email address used for registration and recovery contact.
24595 Setting this is encouraged as it allows you to receive important
24596 notifications about the account and issued certificates.
24598 @item @code{server} (default: @code{#f})
24599 Optional URL of ACME server. Setting this overrides certbot's default,
24600 which is the Let's Encrypt server.
24602 @item @code{rsa-key-size} (default: @code{2048})
24603 Size of the RSA key.
24605 @item @code{default-location} (default: @i{see below})
24606 The default @code{nginx-location-configuration}. Because @code{certbot}
24607 needs to be able to serve challenges and responses, it needs to be able
24608 to run a web server. It does so by extending the @code{nginx} web
24609 service with an @code{nginx-server-configuration} listening on the
24610 @var{domains} on port 80, and which has a
24611 @code{nginx-location-configuration} for the @code{/.well-known/} URI
24612 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
24613 these nginx configuration data types.
24615 Requests to other URL paths will be matched by the
24616 @code{default-location}, which if present is added to all
24617 @code{nginx-server-configuration}s.
24619 By default, the @code{default-location} will issue a redirect from
24620 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
24621 you to define what to serve on your site via @code{https}.
24623 Pass @code{#f} to not issue a default location.
24627 @deftp {Data Type} certificate-configuration
24628 Data type representing the configuration of a certificate.
24629 This type has the following parameters:
24632 @item @code{name} (default: @i{see below})
24633 This name is used by Certbot for housekeeping and in file paths; it
24634 doesn't affect the content of the certificate itself. To see
24635 certificate names, run @code{certbot certificates}.
24637 Its default is the first provided domain.
24639 @item @code{domains} (default: @code{()})
24640 The first domain provided will be the subject CN of the certificate, and
24641 all domains will be Subject Alternative Names on the certificate.
24643 @item @code{challenge} (default: @code{#f})
24644 The challenge type that has to be run by certbot. If @code{#f} is specified,
24645 default to the HTTP challenge. If a value is specified, defaults to the
24646 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
24647 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
24648 and gives Let's Encrypt permission to log the public IP address of the
24649 requesting machine.
24651 @item @code{authentication-hook} (default: @code{#f})
24652 Command to be run in a shell once for each certificate challenge to be
24653 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
24654 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
24655 contains the validation string and @code{$CERTBOT_TOKEN} contains the
24656 file name of the resource requested when performing an HTTP-01 challenge.
24658 @item @code{cleanup-hook} (default: @code{#f})
24659 Command to be run in a shell once for each certificate challenge that
24660 have been answered by the @code{auth-hook}. For this command, the shell
24661 variables available in the @code{auth-hook} script are still available, and
24662 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
24663 of the @code{auth-hook} script.
24665 @item @code{deploy-hook} (default: @code{#f})
24666 Command to be run in a shell once for each successfully issued
24667 certificate. For this command, the shell variable
24668 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
24669 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
24670 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
24671 contain a space-delimited list of renewed certificate domains (for
24672 example, @samp{"example.com www.example.com"}.
24677 For each @code{certificate-configuration}, the certificate is saved to
24678 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
24679 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
24681 @subsection DNS Services
24682 @cindex DNS (domain name system)
24683 @cindex domain name system (DNS)
24685 The @code{(gnu services dns)} module provides services related to the
24686 @dfn{domain name system} (DNS). It provides a server service for hosting
24687 an @emph{authoritative} DNS server for multiple zones, slave or master.
24688 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
24689 caching and forwarding DNS server for the LAN, which uses
24690 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
24692 @subsubheading Knot Service
24694 An example configuration of an authoritative server for two zones, one master
24698 (define-zone-entries example.org.zone
24699 ;; Name TTL Class Type Data
24700 ("@@" "" "IN" "A" "127.0.0.1")
24701 ("@@" "" "IN" "NS" "ns")
24702 ("ns" "" "IN" "A" "127.0.0.1"))
24704 (define master-zone
24705 (knot-zone-configuration
24706 (domain "example.org")
24708 (origin "example.org")
24709 (entries example.org.zone)))))
24712 (knot-zone-configuration
24713 (domain "plop.org")
24714 (dnssec-policy "default")
24715 (master (list "plop-master"))))
24717 (define plop-master
24718 (knot-remote-configuration
24720 (address (list "208.76.58.171"))))
24724 (services (cons* (service knot-service-type
24725 (knot-configuration
24726 (remotes (list plop-master))
24727 (zones (list master-zone slave-zone))))
24732 @deffn {Scheme Variable} knot-service-type
24733 This is the type for the Knot DNS server.
24735 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
24736 zones, that is to say domain names you would buy from a registrar. This server
24737 is not a resolver, meaning that it can only resolve names for which it is
24738 authoritative. This server can be configured to serve zones as a master server
24739 or a slave server as a per-zone basis. Slave zones will get their data from
24740 masters, and will serve it as an authoritative server. From the point of view
24741 of a resolver, there is no difference between master and slave.
24743 The following data types are used to configure the Knot DNS server:
24746 @deftp {Data Type} knot-key-configuration
24747 Data type representing a key.
24748 This type has the following parameters:
24751 @item @code{id} (default: @code{""})
24752 An identifier for other configuration fields to refer to this key. IDs must
24753 be unique and must not be empty.
24755 @item @code{algorithm} (default: @code{#f})
24756 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
24757 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
24758 and @code{'hmac-sha512}.
24760 @item @code{secret} (default: @code{""})
24761 The secret key itself.
24766 @deftp {Data Type} knot-acl-configuration
24767 Data type representing an Access Control List (ACL) configuration.
24768 This type has the following parameters:
24771 @item @code{id} (default: @code{""})
24772 An identifier for other configuration fields to refer to this key. IDs must be
24773 unique and must not be empty.
24775 @item @code{address} (default: @code{'()})
24776 An ordered list of IP addresses, network subnets, or network ranges represented
24777 with strings. The query must match one of them. Empty value means that
24778 address match is not required.
24780 @item @code{key} (default: @code{'()})
24781 An ordered list of references to keys represented with strings. The string
24782 must match a key ID defined in a @code{knot-key-configuration}. No key means
24783 that a key is not require to match that ACL.
24785 @item @code{action} (default: @code{'()})
24786 An ordered list of actions that are permitted or forbidden by this ACL@. Possible
24787 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
24788 and @code{'update}.
24790 @item @code{deny?} (default: @code{#f})
24791 When true, the ACL defines restrictions. Listed actions are forbidden. When
24792 false, listed actions are allowed.
24797 @deftp {Data Type} zone-entry
24798 Data type representing a record entry in a zone file.
24799 This type has the following parameters:
24802 @item @code{name} (default: @code{"@@"})
24803 The name of the record. @code{"@@"} refers to the origin of the zone. Names
24804 are relative to the origin of the zone. For example, in the @code{example.org}
24805 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
24806 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
24807 refers to @code{ns.example.org}.
24809 @item @code{ttl} (default: @code{""})
24810 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
24812 @item @code{class} (default: @code{"IN"})
24813 The class of the record. Knot currently supports only @code{"IN"} and
24814 partially @code{"CH"}.
24816 @item @code{type} (default: @code{"A"})
24817 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
24818 address), NS (Name Server) and MX (Mail eXchange). Many other types are
24821 @item @code{data} (default: @code{""})
24822 The data contained in the record. For instance an IP address associated with
24823 an A record, or a domain name associated with an NS record. Remember that
24824 domain names are relative to the origin unless they end with a dot.
24829 @deftp {Data Type} zone-file
24830 Data type representing the content of a zone file.
24831 This type has the following parameters:
24834 @item @code{entries} (default: @code{'()})
24835 The list of entries. The SOA record is taken care of, so you don't need to
24836 put it in the list of entries. This list should probably contain an entry
24837 for your primary authoritative DNS server. Other than using a list of entries
24838 directly, you can use @code{define-zone-entries} to define a object containing
24839 the list of entries more easily, that you can later pass to the @code{entries}
24840 field of the @code{zone-file}.
24842 @item @code{origin} (default: @code{""})
24843 The name of your zone. This parameter cannot be empty.
24845 @item @code{ns} (default: @code{"ns"})
24846 The domain of your primary authoritative DNS server. The name is relative to
24847 the origin, unless it ends with a dot. It is mandatory that this primary
24848 DNS server corresponds to an NS record in the zone and that it is associated
24849 to an IP address in the list of entries.
24851 @item @code{mail} (default: @code{"hostmaster"})
24852 An email address people can contact you at, as the owner of the zone. This
24853 is translated as @code{<mail>@@<origin>}.
24855 @item @code{serial} (default: @code{1})
24856 The serial number of the zone. As this is used to keep track of changes by
24857 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
24858 Always increment it when you make a change in your zone.
24860 @item @code{refresh} (default: @code{(* 2 24 3600)})
24861 The frequency at which slaves will do a zone transfer. This value is a number
24862 of seconds. It can be computed by multiplications or with
24863 @code{(string->duration)}.
24865 @item @code{retry} (default: @code{(* 15 60)})
24866 The period after which a slave will retry to contact its master when it fails
24867 to do so a first time.
24869 @item @code{expiry} (default: @code{(* 14 24 3600)})
24870 Default TTL of records. Existing records are considered correct for at most
24871 this amount of time. After this period, resolvers will invalidate their cache
24872 and check again that it still exists.
24874 @item @code{nx} (default: @code{3600})
24875 Default TTL of inexistant records. This delay is usually short because you want
24876 your new domains to reach everyone quickly.
24881 @deftp {Data Type} knot-remote-configuration
24882 Data type representing a remote configuration.
24883 This type has the following parameters:
24886 @item @code{id} (default: @code{""})
24887 An identifier for other configuration fields to refer to this remote. IDs must
24888 be unique and must not be empty.
24890 @item @code{address} (default: @code{'()})
24891 An ordered list of destination IP addresses. Addresses are tried in sequence.
24892 An optional port can be given with the @@ separator. For instance:
24893 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
24895 @item @code{via} (default: @code{'()})
24896 An ordered list of source IP addresses. An empty list will have Knot choose
24897 an appropriate source IP@. An optional port can be given with the @@ separator.
24898 The default is to choose at random.
24900 @item @code{key} (default: @code{#f})
24901 A reference to a key, that is a string containing the identifier of a key
24902 defined in a @code{knot-key-configuration} field.
24907 @deftp {Data Type} knot-keystore-configuration
24908 Data type representing a keystore to hold dnssec keys.
24909 This type has the following parameters:
24912 @item @code{id} (default: @code{""})
24913 The id of the keystore. It must not be empty.
24915 @item @code{backend} (default: @code{'pem})
24916 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
24918 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
24919 The configuration string of the backend. An example for the PKCS#11 is:
24920 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
24921 For the pem backend, the string represents a path in the file system.
24926 @deftp {Data Type} knot-policy-configuration
24927 Data type representing a dnssec policy. Knot DNS is able to automatically
24928 sign your zones. It can either generate and manage your keys automatically or
24929 use keys that you generate.
24931 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
24932 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
24933 zone. In order to be trusted, the KSK needs to be present in the parent zone
24934 (usually a top-level domain). If your registrar supports dnssec, you will
24935 have to send them your KSK's hash so they can add a DS record in their zone.
24936 This is not automated and need to be done each time you change your KSK.
24938 The policy also defines the lifetime of keys. Usually, ZSK can be changed
24939 easily and use weaker cryptographic functions (they use lower parameters) in
24940 order to sign records quickly, so they are changed often. The KSK however
24941 requires manual interaction with the registrar, so they are changed less often
24942 and use stronger parameters because they sign only one record.
24944 This type has the following parameters:
24947 @item @code{id} (default: @code{""})
24948 The id of the policy. It must not be empty.
24950 @item @code{keystore} (default: @code{"default"})
24951 A reference to a keystore, that is a string containing the identifier of a
24952 keystore defined in a @code{knot-keystore-configuration} field. The
24953 @code{"default"} identifier means the default keystore (a kasp database that
24954 was setup by this service).
24956 @item @code{manual?} (default: @code{#f})
24957 Whether the key management is manual or automatic.
24959 @item @code{single-type-signing?} (default: @code{#f})
24960 When @code{#t}, use the Single-Type Signing Scheme.
24962 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
24963 An algorithm of signing keys and issued signatures.
24965 @item @code{ksk-size} (default: @code{256})
24966 The length of the KSK@. Note that this value is correct for the default
24967 algorithm, but would be unsecure for other algorithms.
24969 @item @code{zsk-size} (default: @code{256})
24970 The length of the ZSK@. Note that this value is correct for the default
24971 algorithm, but would be unsecure for other algorithms.
24973 @item @code{dnskey-ttl} (default: @code{'default})
24974 The TTL value for DNSKEY records added into zone apex. The special
24975 @code{'default} value means same as the zone SOA TTL.
24977 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
24978 The period between ZSK publication and the next rollover initiation.
24980 @item @code{propagation-delay} (default: @code{(* 24 3600)})
24981 An extra delay added for each key rollover step. This value should be high
24982 enough to cover propagation of data from the master server to all slaves.
24984 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
24985 A validity period of newly issued signatures.
24987 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
24988 A period how long before a signature expiration the signature will be refreshed.
24990 @item @code{nsec3?} (default: @code{#f})
24991 When @code{#t}, NSEC3 will be used instead of NSEC.
24993 @item @code{nsec3-iterations} (default: @code{5})
24994 The number of additional times the hashing is performed.
24996 @item @code{nsec3-salt-length} (default: @code{8})
24997 The length of a salt field in octets, which is appended to the original owner
24998 name before hashing.
25000 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
25001 The validity period of newly issued salt field.
25006 @deftp {Data Type} knot-zone-configuration
25007 Data type representing a zone served by Knot.
25008 This type has the following parameters:
25011 @item @code{domain} (default: @code{""})
25012 The domain served by this configuration. It must not be empty.
25014 @item @code{file} (default: @code{""})
25015 The file where this zone is saved. This parameter is ignored by master zones.
25016 Empty means default location that depends on the domain name.
25018 @item @code{zone} (default: @code{(zone-file)})
25019 The content of the zone file. This parameter is ignored by slave zones. It
25020 must contain a zone-file record.
25022 @item @code{master} (default: @code{'()})
25023 A list of master remotes. When empty, this zone is a master. When set, this
25024 zone is a slave. This is a list of remotes identifiers.
25026 @item @code{ddns-master} (default: @code{#f})
25027 The main master. When empty, it defaults to the first master in the list of
25030 @item @code{notify} (default: @code{'()})
25031 A list of slave remote identifiers.
25033 @item @code{acl} (default: @code{'()})
25034 A list of acl identifiers.
25036 @item @code{semantic-checks?} (default: @code{#f})
25037 When set, this adds more semantic checks to the zone.
25039 @item @code{disable-any?} (default: @code{#f})
25040 When set, this forbids queries of the ANY type.
25042 @item @code{zonefile-sync} (default: @code{0})
25043 The delay between a modification in memory and on disk. 0 means immediate
25046 @item @code{zonefile-load} (default: @code{#f})
25047 The way the zone file contents are applied during zone load. Possible values
25051 @item @code{#f} for using the default value from Knot,
25052 @item @code{'none} for not using the zone file at all,
25053 @item @code{'difference} for computing the difference between already available
25054 contents and zone contents and applying it to the current zone contents,
25055 @item @code{'difference-no-serial} for the same as @code{'difference}, but
25056 ignoring the SOA serial in the zone file, while the server takes care of it
25058 @item @code{'whole} for loading zone contents from the zone file.
25061 @item @code{journal-content} (default: @code{#f})
25062 The way the journal is used to store zone and its changes. Possible values
25063 are @code{'none} to not use it at all, @code{'changes} to store changes and
25064 @code{'all} to store contents. @code{#f} does not set this option, so the
25065 default value from Knot is used.
25067 @item @code{max-journal-usage} (default: @code{#f})
25068 The maximum size for the journal on disk. @code{#f} does not set this option,
25069 so the default value from Knot is used.
25071 @item @code{max-journal-depth} (default: @code{#f})
25072 The maximum size of the history. @code{#f} does not set this option, so the
25073 default value from Knot is used.
25075 @item @code{max-zone-size} (default: @code{#f})
25076 The maximum size of the zone file. This limit is enforced for incoming
25077 transfer and updates. @code{#f} does not set this option, so the default
25078 value from Knot is used.
25080 @item @code{dnssec-policy} (default: @code{#f})
25081 A reference to a @code{knot-policy-configuration} record, or the special
25082 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
25085 @item @code{serial-policy} (default: @code{'increment})
25086 A policy between @code{'increment} and @code{'unixtime}.
25091 @deftp {Data Type} knot-configuration
25092 Data type representing the Knot configuration.
25093 This type has the following parameters:
25096 @item @code{knot} (default: @code{knot})
25099 @item @code{run-directory} (default: @code{"/var/run/knot"})
25100 The run directory. This directory will be used for pid file and sockets.
25102 @item @code{includes} (default: @code{'()})
25103 A list of strings or file-like objects denoting other files that must be
25104 included at the top of the configuration file.
25106 @cindex secrets, Knot service
25107 This can be used to manage secrets out-of-band. For example, secret
25108 keys may be stored in an out-of-band file not managed by Guix, and
25109 thus not visible in @file{/gnu/store}---e.g., you could store secret
25110 key configuration in @file{/etc/knot/secrets.conf} and add this file
25111 to the @code{includes} list.
25113 One can generate a secret tsig key (for nsupdate and zone transfers with the
25114 keymgr command from the knot package. Note that the package is not automatically
25115 installed by the service. The following example shows how to generate a new
25119 keymgr -t mysecret > /etc/knot/secrets.conf
25120 chmod 600 /etc/knot/secrets.conf
25123 Also note that the generated key will be named @var{mysecret}, so it is the
25124 name that needs to be used in the @var{key} field of the
25125 @code{knot-acl-configuration} record and in other places that need to refer
25128 It can also be used to add configuration not supported by this interface.
25130 @item @code{listen-v4} (default: @code{"0.0.0.0"})
25131 An ip address on which to listen.
25133 @item @code{listen-v6} (default: @code{"::"})
25134 An ip address on which to listen.
25136 @item @code{listen-port} (default: @code{53})
25137 A port on which to listen.
25139 @item @code{keys} (default: @code{'()})
25140 The list of knot-key-configuration used by this configuration.
25142 @item @code{acls} (default: @code{'()})
25143 The list of knot-acl-configuration used by this configuration.
25145 @item @code{remotes} (default: @code{'()})
25146 The list of knot-remote-configuration used by this configuration.
25148 @item @code{zones} (default: @code{'()})
25149 The list of knot-zone-configuration used by this configuration.
25154 @subsubheading Knot Resolver Service
25156 @deffn {Scheme Variable} knot-resolver-service-type
25157 This is the type of the knot resolver service, whose value should be
25158 an @code{knot-resolver-configuration} object as in this example:
25161 (service knot-resolver-service-type
25162 (knot-resolver-configuration
25163 (kresd-config-file (plain-file "kresd.conf" "
25164 net.listen('192.168.0.1', 5353)
25165 user('knot-resolver', 'knot-resolver')
25166 modules = @{ 'hints > iterate', 'stats', 'predict' @}
25167 cache.size = 100 * MB
25171 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
25174 @deftp {Data Type} knot-resolver-configuration
25175 Data type representing the configuration of knot-resolver.
25178 @item @code{package} (default: @var{knot-resolver})
25179 Package object of the knot DNS resolver.
25181 @item @code{kresd-config-file} (default: %kresd.conf)
25182 File-like object of the kresd configuration file to use, by default it
25183 will listen on @code{127.0.0.1} and @code{::1}.
25185 @item @code{garbage-collection-interval} (default: 1000)
25186 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
25192 @subsubheading Dnsmasq Service
25194 @deffn {Scheme Variable} dnsmasq-service-type
25195 This is the type of the dnsmasq service, whose value should be an
25196 @code{dnsmasq-configuration} object as in this example:
25199 (service dnsmasq-service-type
25200 (dnsmasq-configuration
25202 (servers '("192.168.1.1"))))
25206 @deftp {Data Type} dnsmasq-configuration
25207 Data type representing the configuration of dnsmasq.
25210 @item @code{package} (default: @var{dnsmasq})
25211 Package object of the dnsmasq server.
25213 @item @code{no-hosts?} (default: @code{#f})
25214 When true, don't read the hostnames in /etc/hosts.
25216 @item @code{port} (default: @code{53})
25217 The port to listen on. Setting this to zero completely disables DNS
25218 responses, leaving only DHCP and/or TFTP functions.
25220 @item @code{local-service?} (default: @code{#t})
25221 Accept DNS queries only from hosts whose address is on a local subnet,
25222 ie a subnet for which an interface exists on the server.
25224 @item @code{listen-addresses} (default: @code{'()})
25225 Listen on the given IP addresses.
25227 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
25228 The file to read the IP address of the upstream nameservers from.
25230 @item @code{no-resolv?} (default: @code{#f})
25231 When true, don't read @var{resolv-file}.
25233 @item @code{servers} (default: @code{'()})
25234 Specify IP address of upstream servers directly.
25236 @item @code{addresses} (default: @code{'()})
25237 For each entry, specify an IP address to return for any host in the
25238 given domains. Queries in the domains are never forwarded and always
25239 replied to with the specified IP address.
25241 This is useful for redirecting hosts locally, for example:
25244 (service dnsmasq-service-type
25245 (dnsmasq-configuration
25247 '(; Redirect to a local web-server.
25248 "/example.org/127.0.0.1"
25249 ; Redirect subdomain to a specific IP.
25250 "/subdomain.example.org/192.168.1.42"))))
25253 Note that rules in @file{/etc/hosts} take precedence over this.
25255 @item @code{cache-size} (default: @code{150})
25256 Set the size of dnsmasq's cache. Setting the cache size to zero
25259 @item @code{negative-cache?} (default: @code{#t})
25260 When false, disable negative caching.
25262 @item @code{tftp-enable?} (default: @code{#f})
25263 Whether to enable the built-in TFTP server.
25265 @item @code{tftp-no-fail?} (default: @code{#f})
25266 If true, does not fail dnsmasq if the TFTP server could not start up.
25268 @item @code{tftp-single-port?} (default: @code{#f})
25269 Whether to use only one single port for TFTP.
25271 @item @code{tftp-secure?} (default: @code{#f})
25272 If true, only files owned by the user running the dnsmasq process are accessible.
25274 If dnsmasq is being run as root, different rules apply:
25275 @code{tftp-secure?} has no effect, but only files which have the
25276 world-readable bit set are accessible.
25278 @item @code{tftp-max} (default: @code{#f})
25279 If set, sets the maximal number of concurrent connections allowed.
25281 @item @code{tftp-mtu} (default: @code{#f})
25282 If set, sets the MTU for TFTP packets to that value.
25284 @item @code{tftp-no-blocksize?} (default: @code{#f})
25285 If true, stops the TFTP server from negotiating the blocksize with a client.
25287 @item @code{tftp-lowercase?} (default: @code{#f})
25288 Whether to convert all filenames in TFTP requests to lowercase.
25290 @item @code{tftp-port-range} (default: @code{#f})
25291 If set, fixes the dynamical ports (one per client) to the given range
25292 (@code{"<start>,<end>"}).
25294 @item @code{tftp-root} (default: @code{/var/empty,lo})
25295 Look for files to transfer using TFTP relative to the given directory.
25296 When this is set, TFTP paths which include @samp{..} are rejected, to stop clients
25297 getting outside the specified root. Absolute paths (starting with @samp{/}) are
25298 allowed, but they must be within the TFTP-root. If the optional interface
25299 argument is given, the directory is only used for TFTP requests via that
25302 @item @code{tftp-unique-root} (default: @code{#f})
25303 If set, add the IP or hardware address of the TFTP client as a path component
25304 on the end of the TFTP-root. Only valid if a TFTP root is set and the
25305 directory exists. Defaults to adding IP address (in standard dotted-quad
25308 For instance, if @option{--tftp-root} is @samp{/tftp} and client
25309 @samp{1.2.3.4} requests file @file{myfile} then the effective path will
25310 be @file{/tftp/1.2.3.4/myfile} if @file{/tftp/1.2.3.4} exists or
25311 @file{/tftp/myfile} otherwise. When @samp{=mac} is specified it will
25312 append the MAC address instead, using lowercase zero padded digits
25313 separated by dashes, e.g.: @samp{01-02-03-04-aa-bb}. Note that
25314 resolving MAC addresses is only possible if the client is in the local
25315 network or obtained a DHCP lease from dnsmasq.
25320 @subsubheading ddclient Service
25323 The ddclient service described below runs the ddclient daemon, which takes
25324 care of automatically updating DNS entries for service providers such as
25325 @uref{https://dyn.com/dns/, Dyn}.
25327 The following example show instantiates the service with its default
25331 (service ddclient-service-type)
25334 Note that ddclient needs to access credentials that are stored in a
25335 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
25336 @code{secret-file} below). You are expected to create this file manually, in
25337 an ``out-of-band'' fashion (you @emph{could} make this file part of the
25338 service configuration, for instance by using @code{plain-file}, but it will be
25339 world-readable @i{via} @file{/gnu/store}). See the examples in the
25340 @file{share/ddclient} directory of the @code{ddclient} package.
25342 @c %start of fragment
25344 Available @code{ddclient-configuration} fields are:
25346 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
25347 The ddclient package.
25351 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
25352 The period after which ddclient will retry to check IP and domain name.
25354 Defaults to @samp{300}.
25358 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
25359 Use syslog for the output.
25361 Defaults to @samp{#t}.
25365 @deftypevr {@code{ddclient-configuration} parameter} string mail
25368 Defaults to @samp{"root"}.
25372 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
25373 Mail failed update to user.
25375 Defaults to @samp{"root"}.
25379 @deftypevr {@code{ddclient-configuration} parameter} string pid
25380 The ddclient PID file.
25382 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
25386 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
25387 Enable SSL support.
25389 Defaults to @samp{#t}.
25393 @deftypevr {@code{ddclient-configuration} parameter} string user
25394 Specifies the user name or ID that is used when running ddclient
25397 Defaults to @samp{"ddclient"}.
25401 @deftypevr {@code{ddclient-configuration} parameter} string group
25402 Group of the user who will run the ddclient program.
25404 Defaults to @samp{"ddclient"}.
25408 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
25409 Secret file which will be appended to @file{ddclient.conf} file. This
25410 file contains credentials for use by ddclient. You are expected to
25411 create it manually.
25413 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
25417 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
25418 Extra options will be appended to @file{ddclient.conf} file.
25420 Defaults to @samp{()}.
25425 @c %end of fragment
25429 @subsection VPN Services
25430 @cindex VPN (virtual private network)
25431 @cindex virtual private network (VPN)
25433 The @code{(gnu services vpn)} module provides services related to
25434 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
25435 your machine to connect to a VPN, and a @emph{server} service for your machine
25436 to host a VPN@. Both services use @uref{https://openvpn.net/, OpenVPN}.
25438 @deffn {Scheme Procedure} openvpn-client-service @
25439 [#:config (openvpn-client-configuration)]
25441 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
25444 @deffn {Scheme Procedure} openvpn-server-service @
25445 [#:config (openvpn-server-configuration)]
25447 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
25449 Both can be run simultaneously.
25452 @c %automatically generated documentation
25454 Available @code{openvpn-client-configuration} fields are:
25456 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
25457 The OpenVPN package.
25461 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
25462 The OpenVPN pid file.
25464 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
25468 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
25469 The protocol (UDP or TCP) used to open a channel between clients and
25472 Defaults to @samp{udp}.
25476 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
25477 The device type used to represent the VPN connection.
25479 Defaults to @samp{tun}.
25483 If you do not have some of these files (eg.@: you use a username and
25484 password), you can disable any of the following three fields by setting
25485 it to @code{'disabled}.
25487 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string ca
25488 The certificate authority to check connections against.
25490 Defaults to @samp{"/etc/openvpn/ca.crt"}.
25494 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string cert
25495 The certificate of the machine the daemon is running on. It should be
25496 signed by the authority given in @code{ca}.
25498 Defaults to @samp{"/etc/openvpn/client.crt"}.
25502 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string key
25503 The key of the machine the daemon is running on. It must be the key whose
25504 certificate is @code{cert}.
25506 Defaults to @samp{"/etc/openvpn/client.key"}.
25510 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
25511 Whether to use the lzo compression algorithm.
25513 Defaults to @samp{#t}.
25517 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
25518 Don't re-read key files across SIGUSR1 or --ping-restart.
25520 Defaults to @samp{#t}.
25524 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
25525 Don't close and reopen TUN/TAP device or run up/down scripts across
25526 SIGUSR1 or --ping-restart restarts.
25528 Defaults to @samp{#t}.
25532 @deftypevr {@code{openvpn-client-configuration} parameter} boolean fast-io?
25533 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
25534 poll/epoll/select prior to the write operation.
25536 Defaults to @samp{#f}.
25539 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
25542 Defaults to @samp{3}.
25546 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
25547 Add an additional layer of HMAC authentication on top of the TLS control
25548 channel to protect against DoS attacks.
25550 Defaults to @samp{#f}.
25554 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string auth-user-pass
25555 Authenticate with server using username/password. The option is a file
25556 containing username/password on 2 lines. Do not use a file-like object as it
25557 would be added to the store and readable by any user.
25559 Defaults to @samp{'disabled}.
25562 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
25563 Whether to check the server certificate has server usage extension.
25565 Defaults to @samp{#t}.
25569 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
25570 Bind to a specific local port number.
25572 Defaults to @samp{#f}.
25576 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
25577 Retry resolving server address.
25579 Defaults to @samp{#t}.
25583 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
25584 A list of remote servers to connect to.
25586 Defaults to @samp{()}.
25588 Available @code{openvpn-remote-configuration} fields are:
25590 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
25593 Defaults to @samp{"my-server"}.
25597 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
25598 Port number the server listens to.
25600 Defaults to @samp{1194}.
25605 @c %end of automatic openvpn-client documentation
25607 @c %automatically generated documentation
25609 Available @code{openvpn-server-configuration} fields are:
25611 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
25612 The OpenVPN package.
25616 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
25617 The OpenVPN pid file.
25619 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
25623 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
25624 The protocol (UDP or TCP) used to open a channel between clients and
25627 Defaults to @samp{udp}.
25631 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
25632 The device type used to represent the VPN connection.
25634 Defaults to @samp{tun}.
25638 If you do not have some of these files (eg.@: you use a username and
25639 password), you can disable any of the following three fields by setting
25640 it to @code{'disabled}.
25642 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string ca
25643 The certificate authority to check connections against.
25645 Defaults to @samp{"/etc/openvpn/ca.crt"}.
25649 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string cert
25650 The certificate of the machine the daemon is running on. It should be
25651 signed by the authority given in @code{ca}.
25653 Defaults to @samp{"/etc/openvpn/client.crt"}.
25657 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string key
25658 The key of the machine the daemon is running on. It must be the key whose
25659 certificate is @code{cert}.
25661 Defaults to @samp{"/etc/openvpn/client.key"}.
25665 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
25666 Whether to use the lzo compression algorithm.
25668 Defaults to @samp{#t}.
25672 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
25673 Don't re-read key files across SIGUSR1 or --ping-restart.
25675 Defaults to @samp{#t}.
25679 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
25680 Don't close and reopen TUN/TAP device or run up/down scripts across
25681 SIGUSR1 or --ping-restart restarts.
25683 Defaults to @samp{#t}.
25687 @deftypevr {@code{openvpn-server-configuration} parameter} boolean fast-io?
25688 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
25689 poll/epoll/select prior to the write operation.
25691 Defaults to @samp{#f}.
25694 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
25697 Defaults to @samp{3}.
25701 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
25702 Add an additional layer of HMAC authentication on top of the TLS control
25703 channel to protect against DoS attacks.
25705 Defaults to @samp{#f}.
25709 @deftypevr {@code{openvpn-server-configuration} parameter} number port
25710 Specifies the port number on which the server listens.
25712 Defaults to @samp{1194}.
25716 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
25717 An ip and mask specifying the subnet inside the virtual network.
25719 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
25723 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
25724 A CIDR notation specifying the IPv6 subnet inside the virtual network.
25726 Defaults to @samp{#f}.
25730 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
25731 The Diffie-Hellman parameters file.
25733 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
25737 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
25738 The file that records client IPs.
25740 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
25744 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
25745 When true, the server will act as a gateway for its clients.
25747 Defaults to @samp{#f}.
25751 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
25752 When true, clients are allowed to talk to each other inside the VPN.
25754 Defaults to @samp{#f}.
25758 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
25759 Causes ping-like messages to be sent back and forth over the link so
25760 that each side knows when the other side has gone down. @code{keepalive}
25761 requires a pair. The first element is the period of the ping sending,
25762 and the second element is the timeout before considering the other side
25767 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
25768 The maximum number of clients.
25770 Defaults to @samp{100}.
25774 @deftypevr {@code{openvpn-server-configuration} parameter} string status
25775 The status file. This file shows a small report on current connection.
25776 It is truncated and rewritten every minute.
25778 Defaults to @samp{"/var/run/openvpn/status"}.
25782 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
25783 The list of configuration for some clients.
25785 Defaults to @samp{()}.
25787 Available @code{openvpn-ccd-configuration} fields are:
25789 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
25792 Defaults to @samp{"client"}.
25796 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
25799 Defaults to @samp{#f}.
25803 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
25806 Defaults to @samp{#f}.
25813 @c %end of automatic openvpn-server documentation
25816 @node Network File System
25817 @subsection Network File System
25820 The @code{(gnu services nfs)} module provides the following services,
25821 which are most commonly used in relation to mounting or exporting
25822 directory trees as @dfn{network file systems} (NFS).
25824 While it is possible to use the individual components that together make
25825 up a Network File System service, we recommended to configure an NFS
25826 server with the @code{nfs-service-type}.
25828 @subsubheading NFS Service
25829 @cindex NFS, server
25831 The NFS service takes care of setting up all NFS component services,
25832 kernel configuration file systems, and installs configuration files in
25833 the locations that NFS expects.
25835 @defvr {Scheme Variable} nfs-service-type
25836 A service type for a complete NFS server.
25839 @deftp {Data Type} nfs-configuration
25840 This data type represents the configuration of the NFS service and all
25843 It has the following parameters:
25845 @item @code{nfs-utils} (default: @code{nfs-utils})
25846 The nfs-utils package to use.
25848 @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
25849 If a list of string values is provided, the @command{rpc.nfsd} daemon
25850 will be limited to supporting the given versions of the NFS protocol.
25852 @item @code{exports} (default: @code{'()})
25853 This is a list of directories the NFS server should export. Each entry
25854 is a list consisting of two elements: a directory name and a string
25855 containing all options. This is an example in which the directory
25856 @file{/export} is served to all NFS clients as a read-only share:
25862 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
25865 @item @code{rpcmountd-port} (default: @code{#f})
25866 The network port that the @command{rpc.mountd} daemon should use.
25868 @item @code{rpcstatd-port} (default: @code{#f})
25869 The network port that the @command{rpc.statd} daemon should use.
25871 @item @code{rpcbind} (default: @code{rpcbind})
25872 The rpcbind package to use.
25874 @item @code{idmap-domain} (default: @code{"localdomain"})
25875 The local NFSv4 domain name.
25877 @item @code{nfsd-port} (default: @code{2049})
25878 The network port that the @command{nfsd} daemon should use.
25880 @item @code{nfsd-threads} (default: @code{8})
25881 The number of threads used by the @command{nfsd} daemon.
25883 @item @code{nfsd-tcp?} (default: @code{#t})
25884 Whether the @command{nfsd} daemon should listen on a TCP socket.
25886 @item @code{nfsd-udp?} (default: @code{#f})
25887 Whether the @command{nfsd} daemon should listen on a UDP socket.
25889 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
25890 The directory where the pipefs file system is mounted.
25892 @item @code{debug} (default: @code{'()"})
25893 A list of subsystems for which debugging output should be enabled. This
25894 is a list of symbols. Any of these symbols are valid: @code{nfsd},
25895 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
25899 If you don't need a complete NFS service or prefer to build it yourself
25900 you can use the individual component services that are documented below.
25902 @subsubheading RPC Bind Service
25905 The RPC Bind service provides a facility to map program numbers into
25906 universal addresses.
25907 Many NFS related services use this facility. Hence it is automatically
25908 started when a dependent service starts.
25910 @defvr {Scheme Variable} rpcbind-service-type
25911 A service type for the RPC portmapper daemon.
25915 @deftp {Data Type} rpcbind-configuration
25916 Data type representing the configuration of the RPC Bind Service.
25917 This type has the following parameters:
25919 @item @code{rpcbind} (default: @code{rpcbind})
25920 The rpcbind package to use.
25922 @item @code{warm-start?} (default: @code{#t})
25923 If this parameter is @code{#t}, then the daemon will read a
25924 state file on startup thus reloading state information saved by a previous
25930 @subsubheading Pipefs Pseudo File System
25934 The pipefs file system is used to transfer NFS related data
25935 between the kernel and user space programs.
25937 @defvr {Scheme Variable} pipefs-service-type
25938 A service type for the pipefs pseudo file system.
25941 @deftp {Data Type} pipefs-configuration
25942 Data type representing the configuration of the pipefs pseudo file system service.
25943 This type has the following parameters:
25945 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
25946 The directory to which the file system is to be attached.
25951 @subsubheading GSS Daemon Service
25954 @cindex global security system
25956 The @dfn{global security system} (GSS) daemon provides strong security for RPC
25958 Before exchanging RPC requests an RPC client must establish a security
25959 context. Typically this is done using the Kerberos command @command{kinit}
25960 or automatically at login time using PAM services (@pxref{Kerberos Services}).
25962 @defvr {Scheme Variable} gss-service-type
25963 A service type for the Global Security System (GSS) daemon.
25966 @deftp {Data Type} gss-configuration
25967 Data type representing the configuration of the GSS daemon service.
25968 This type has the following parameters:
25970 @item @code{nfs-utils} (default: @code{nfs-utils})
25971 The package in which the @command{rpc.gssd} command is to be found.
25973 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
25974 The directory where the pipefs file system is mounted.
25980 @subsubheading IDMAP Daemon Service
25982 @cindex name mapper
25984 The idmap daemon service provides mapping between user IDs and user names.
25985 Typically it is required in order to access file systems mounted via NFSv4.
25987 @defvr {Scheme Variable} idmap-service-type
25988 A service type for the Identity Mapper (IDMAP) daemon.
25991 @deftp {Data Type} idmap-configuration
25992 Data type representing the configuration of the IDMAP daemon service.
25993 This type has the following parameters:
25995 @item @code{nfs-utils} (default: @code{nfs-utils})
25996 The package in which the @command{rpc.idmapd} command is to be found.
25998 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
25999 The directory where the pipefs file system is mounted.
26001 @item @code{domain} (default: @code{#f})
26002 The local NFSv4 domain name.
26003 This must be a string or @code{#f}.
26004 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
26006 @item @code{verbosity} (default: @code{0})
26007 The verbosity level of the daemon.
26012 @node Continuous Integration
26013 @subsection Continuous Integration
26015 @cindex continuous integration
26016 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
26017 continuous integration tool for Guix. It can be used both for development and
26018 for providing substitutes to others (@pxref{Substitutes}).
26020 The @code{(gnu services cuirass)} module provides the following service.
26022 @defvr {Scheme Procedure} cuirass-service-type
26023 The type of the Cuirass service. Its value must be a
26024 @code{cuirass-configuration} object, as described below.
26027 To add build jobs, you have to set the @code{specifications} field of the
26028 configuration. Here is an example of a service that polls the Guix repository
26029 and builds the packages from a manifest. Some of the packages are defined in
26030 the @code{"custom-packages"} input, which is the equivalent of
26031 @env{GUIX_PACKAGE_PATH}.
26034 (define %cuirass-specs
26036 '((#:name . "my-manifest")
26037 (#:load-path-inputs . ("guix"))
26038 (#:package-path-inputs . ("custom-packages"))
26039 (#:proc-input . "guix")
26040 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
26041 (#:proc . cuirass-jobs)
26042 (#:proc-args . ((subset . "manifests")
26043 (systems . ("x86_64-linux"))
26044 (manifests . (("config" . "guix/manifest.scm")))))
26045 (#:inputs . (((#:name . "guix")
26046 (#:url . "git://git.savannah.gnu.org/guix.git")
26047 (#:load-path . ".")
26048 (#:branch . "master")
26049 (#:no-compile? . #t))
26050 ((#:name . "config")
26051 (#:url . "https://git.example.org/config.git")
26052 (#:load-path . ".")
26053 (#:branch . "master")
26054 (#:no-compile? . #t))
26055 ((#:name . "custom-packages")
26056 (#:url . "https://git.example.org/custom-packages.git")
26057 (#:load-path . ".")
26058 (#:branch . "master")
26059 (#:no-compile? . #t)))))))
26061 (service cuirass-service-type
26062 (cuirass-configuration
26063 (specifications %cuirass-specs)))
26066 While information related to build jobs is located directly in the
26067 specifications, global settings for the @command{cuirass} process are
26068 accessible in other @code{cuirass-configuration} fields.
26070 @deftp {Data Type} cuirass-configuration
26071 Data type representing the configuration of Cuirass.
26074 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
26075 Location of the log file.
26077 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
26078 Location of the log file used by the web interface.
26080 @item @code{queries-log-file} (default: @code{#f})
26081 Location of the SQL queries log file. By default, SQL queries logging is
26084 @item @code{web-queries-log-file} (default: @code{#f})
26085 Location of the web SQL queries log file. By default, web SQL queries
26086 logging is disabled.
26088 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
26089 Location of the repository cache.
26091 @item @code{user} (default: @code{"cuirass"})
26092 Owner of the @code{cuirass} process.
26094 @item @code{group} (default: @code{"cuirass"})
26095 Owner's group of the @code{cuirass} process.
26097 @item @code{interval} (default: @code{60})
26098 Number of seconds between the poll of the repositories followed by the
26101 @item @code{queue-size} (default: @code{1})
26102 Size of the database writer queue.
26104 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
26105 Location of sqlite database which contains the build results and previously
26106 added specifications.
26108 @item @code{ttl} (default: @code{(* 30 24 3600)})
26109 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
26110 are registered for build results. This means that build results are protected
26111 from garbage collection for at least @var{ttl} seconds.
26113 @item @code{port} (default: @code{8081})
26114 Port number used by the HTTP server.
26116 @item @code{host} (default: @code{"localhost"})
26117 Listen on the network interface for @var{host}. The default is to
26118 accept connections from localhost.
26120 @item @code{specifications} (default: @code{#~'()})
26121 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
26122 where a specification is an association list
26123 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
26124 keys are keywords (@code{#:keyword-example}) as shown in the example
26127 @item @code{use-substitutes?} (default: @code{#f})
26128 This allows using substitutes to avoid building every dependencies of a job
26131 @item @code{one-shot?} (default: @code{#f})
26132 Only evaluate specifications and build derivations once.
26134 @item @code{fallback?} (default: @code{#f})
26135 When substituting a pre-built binary fails, fall back to building
26138 @item @code{extra-options} (default: @code{'()})
26139 Extra options to pass when running the Cuirass processes.
26141 @item @code{cuirass} (default: @code{cuirass})
26142 The Cuirass package to use.
26146 @node Power Management Services
26147 @subsection Power Management Services
26150 @cindex power management with TLP
26151 @subsubheading TLP daemon
26153 The @code{(gnu services pm)} module provides a Guix service definition
26154 for the Linux power management tool TLP.
26156 TLP enables various powersaving modes in userspace and kernel.
26157 Contrary to @code{upower-service}, it is not a passive,
26158 monitoring tool, as it will apply custom settings each time a new power
26159 source is detected. More information can be found at
26160 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
26162 @deffn {Scheme Variable} tlp-service-type
26163 The service type for the TLP tool. The default settings are optimised
26164 for battery life on most systems, but you can tweak them to your heart's
26165 content by adding a valid @code{tlp-configuration}:
26167 (service tlp-service-type
26169 (cpu-scaling-governor-on-ac (list "performance"))
26170 (sched-powersave-on-bat? #t)))
26174 Each parameter definition is preceded by its type; for example,
26175 @samp{boolean foo} indicates that the @code{foo} parameter
26176 should be specified as a boolean. Types starting with
26177 @code{maybe-} denote parameters that won't show up in TLP config file
26178 when their value is @code{'disabled}.
26180 @c The following documentation was initially generated by
26181 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
26182 @c documentation is better, so we shouldn't hesitate to edit below as
26183 @c needed. However if the change you want to make to this documentation
26184 @c can be done in an automated way, it's probably easier to change
26185 @c (generate-documentation) than to make it below and have to deal with
26186 @c the churn as TLP updates.
26188 Available @code{tlp-configuration} fields are:
26190 @deftypevr {@code{tlp-configuration} parameter} package tlp
26195 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
26196 Set to true if you wish to enable TLP.
26198 Defaults to @samp{#t}.
26202 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
26203 Default mode when no power supply can be detected. Alternatives are AC
26206 Defaults to @samp{"AC"}.
26210 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
26211 Number of seconds Linux kernel has to wait after the disk goes idle,
26212 before syncing on AC.
26214 Defaults to @samp{0}.
26218 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
26219 Same as @code{disk-idle-ac} but on BAT mode.
26221 Defaults to @samp{2}.
26225 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
26226 Dirty pages flushing periodicity, expressed in seconds.
26228 Defaults to @samp{15}.
26232 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
26233 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
26235 Defaults to @samp{60}.
26239 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
26240 CPU frequency scaling governor on AC mode. With intel_pstate driver,
26241 alternatives are powersave and performance. With acpi-cpufreq driver,
26242 alternatives are ondemand, powersave, performance and conservative.
26244 Defaults to @samp{disabled}.
26248 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
26249 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
26251 Defaults to @samp{disabled}.
26255 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
26256 Set the min available frequency for the scaling governor on AC.
26258 Defaults to @samp{disabled}.
26262 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
26263 Set the max available frequency for the scaling governor on AC.
26265 Defaults to @samp{disabled}.
26269 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
26270 Set the min available frequency for the scaling governor on BAT.
26272 Defaults to @samp{disabled}.
26276 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
26277 Set the max available frequency for the scaling governor on BAT.
26279 Defaults to @samp{disabled}.
26283 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
26284 Limit the min P-state to control the power dissipation of the CPU, in AC
26285 mode. Values are stated as a percentage of the available performance.
26287 Defaults to @samp{disabled}.
26291 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
26292 Limit the max P-state to control the power dissipation of the CPU, in AC
26293 mode. Values are stated as a percentage of the available performance.
26295 Defaults to @samp{disabled}.
26299 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
26300 Same as @code{cpu-min-perf-on-ac} on BAT mode.
26302 Defaults to @samp{disabled}.
26306 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
26307 Same as @code{cpu-max-perf-on-ac} on BAT mode.
26309 Defaults to @samp{disabled}.
26313 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
26314 Enable CPU turbo boost feature on AC mode.
26316 Defaults to @samp{disabled}.
26320 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
26321 Same as @code{cpu-boost-on-ac?} on BAT mode.
26323 Defaults to @samp{disabled}.
26327 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
26328 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
26329 used under light load conditions.
26331 Defaults to @samp{#f}.
26335 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
26336 Same as @code{sched-powersave-on-ac?} but on BAT mode.
26338 Defaults to @samp{#t}.
26342 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
26343 Enable Linux kernel NMI watchdog.
26345 Defaults to @samp{#f}.
26349 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
26350 For Linux kernels with PHC patch applied, change CPU voltages. An
26351 example value would be @samp{"F:V F:V F:V F:V"}.
26353 Defaults to @samp{disabled}.
26357 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
26358 Set CPU performance versus energy saving policy on AC@. Alternatives are
26359 performance, normal, powersave.
26361 Defaults to @samp{"performance"}.
26365 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
26366 Same as @code{energy-perf-policy-ac} but on BAT mode.
26368 Defaults to @samp{"powersave"}.
26372 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
26377 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
26378 Hard disk advanced power management level.
26382 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
26383 Same as @code{disk-apm-bat} but on BAT mode.
26387 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
26388 Hard disk spin down timeout. One value has to be specified for each
26389 declared hard disk.
26391 Defaults to @samp{disabled}.
26395 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
26396 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
26398 Defaults to @samp{disabled}.
26402 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
26403 Select IO scheduler for disk devices. One value has to be specified for
26404 each declared hard disk. Example alternatives are cfq, deadline and
26407 Defaults to @samp{disabled}.
26411 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
26412 SATA aggressive link power management (ALPM) level. Alternatives are
26413 min_power, medium_power, max_performance.
26415 Defaults to @samp{"max_performance"}.
26419 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
26420 Same as @code{sata-linkpwr-ac} but on BAT mode.
26422 Defaults to @samp{"min_power"}.
26426 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
26427 Exclude specified SATA host devices for link power management.
26429 Defaults to @samp{disabled}.
26433 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
26434 Enable Runtime Power Management for AHCI controller and disks on AC
26437 Defaults to @samp{disabled}.
26441 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
26442 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
26444 Defaults to @samp{disabled}.
26448 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
26449 Seconds of inactivity before disk is suspended.
26451 Defaults to @samp{15}.
26455 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
26456 PCI Express Active State Power Management level. Alternatives are
26457 default, performance, powersave.
26459 Defaults to @samp{"performance"}.
26463 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
26464 Same as @code{pcie-aspm-ac} but on BAT mode.
26466 Defaults to @samp{"powersave"}.
26470 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
26471 Radeon graphics clock speed level. Alternatives are low, mid, high,
26474 Defaults to @samp{"high"}.
26478 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
26479 Same as @code{radeon-power-ac} but on BAT mode.
26481 Defaults to @samp{"low"}.
26485 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
26486 Radeon dynamic power management method (DPM). Alternatives are battery,
26489 Defaults to @samp{"performance"}.
26493 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
26494 Same as @code{radeon-dpm-state-ac} but on BAT mode.
26496 Defaults to @samp{"battery"}.
26500 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
26501 Radeon DPM performance level. Alternatives are auto, low, high.
26503 Defaults to @samp{"auto"}.
26507 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
26508 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
26510 Defaults to @samp{"auto"}.
26514 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
26515 Wifi power saving mode.
26517 Defaults to @samp{#f}.
26521 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
26522 Same as @code{wifi-power-ac?} but on BAT mode.
26524 Defaults to @samp{#t}.
26528 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
26529 Disable wake on LAN.
26531 Defaults to @samp{#t}.
26535 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
26536 Timeout duration in seconds before activating audio power saving on
26537 Intel HDA and AC97 devices. A value of 0 disables power saving.
26539 Defaults to @samp{0}.
26543 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
26544 Same as @code{sound-powersave-ac} but on BAT mode.
26546 Defaults to @samp{1}.
26550 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
26551 Disable controller in powersaving mode on Intel HDA devices.
26553 Defaults to @samp{#t}.
26557 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
26558 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
26559 powered on again by releasing (and reinserting) the eject lever or by
26560 pressing the disc eject button on newer models.
26562 Defaults to @samp{#f}.
26566 @deftypevr {@code{tlp-configuration} parameter} string bay-device
26567 Name of the optical drive device to power off.
26569 Defaults to @samp{"sr0"}.
26573 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
26574 Runtime Power Management for PCI(e) bus devices. Alternatives are on
26577 Defaults to @samp{"on"}.
26581 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
26582 Same as @code{runtime-pm-ac} but on BAT mode.
26584 Defaults to @samp{"auto"}.
26588 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
26589 Runtime Power Management for all PCI(e) bus devices, except blacklisted
26592 Defaults to @samp{#t}.
26596 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
26597 Exclude specified PCI(e) device addresses from Runtime Power Management.
26599 Defaults to @samp{disabled}.
26603 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
26604 Exclude PCI(e) devices assigned to the specified drivers from Runtime
26609 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
26610 Enable USB autosuspend feature.
26612 Defaults to @samp{#t}.
26616 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
26617 Exclude specified devices from USB autosuspend.
26619 Defaults to @samp{disabled}.
26623 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
26624 Exclude WWAN devices from USB autosuspend.
26626 Defaults to @samp{#t}.
26630 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
26631 Include specified devices into USB autosuspend, even if they are already
26632 excluded by the driver or via @code{usb-blacklist-wwan?}.
26634 Defaults to @samp{disabled}.
26638 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
26639 Enable USB autosuspend before shutdown.
26641 Defaults to @samp{disabled}.
26645 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
26646 Restore radio device state (bluetooth, wifi, wwan) from previous
26647 shutdown on system startup.
26649 Defaults to @samp{#f}.
26654 @cindex CPU frequency scaling with thermald
26655 @subsubheading Thermald daemon
26657 The @code{(gnu services pm)} module provides an interface to
26658 thermald, a CPU frequency scaling service which helps prevent overheating.
26660 @defvr {Scheme Variable} thermald-service-type
26661 This is the service type for
26662 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
26663 Thermal Daemon, which is responsible for controlling the thermal state
26664 of processors and preventing overheating.
26667 @deftp {Data Type} thermald-configuration
26668 Data type representing the configuration of @code{thermald-service-type}.
26671 @item @code{ignore-cpuid-check?} (default: @code{#f})
26672 Ignore cpuid check for supported CPU models.
26674 @item @code{thermald} (default: @var{thermald})
26675 Package object of thermald.
26680 @node Audio Services
26681 @subsection Audio Services
26683 The @code{(gnu services audio)} module provides a service to start MPD
26684 (the Music Player Daemon).
26687 @subsubheading Music Player Daemon
26689 The Music Player Daemon (MPD) is a service that can play music while
26690 being controlled from the local machine or over the network by a variety
26693 The following example shows how one might run @code{mpd} as user
26694 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
26697 (service mpd-service-type
26703 @defvr {Scheme Variable} mpd-service-type
26704 The service type for @command{mpd}
26707 @deftp {Data Type} mpd-configuration
26708 Data type representing the configuration of @command{mpd}.
26711 @item @code{user} (default: @code{"mpd"})
26712 The user to run mpd as.
26714 @item @code{music-dir} (default: @code{"~/Music"})
26715 The directory to scan for music files.
26717 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
26718 The directory to store playlists.
26720 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
26721 The location of the music database.
26723 @item @code{state-file} (default: @code{"~/.mpd/state"})
26724 The location of the file that stores current MPD's state.
26726 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
26727 The location of the sticker database.
26729 @item @code{port} (default: @code{"6600"})
26730 The port to run mpd on.
26732 @item @code{address} (default: @code{"any"})
26733 The address that mpd will bind to. To use a Unix domain socket,
26734 an absolute path can be specified here.
26736 @item @code{outputs} (default: @code{"(list (mpd-output))"})
26737 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
26742 @deftp {Data Type} mpd-output
26743 Data type representing an @command{mpd} audio output.
26746 @item @code{name} (default: @code{"MPD"})
26747 The name of the audio output.
26749 @item @code{type} (default: @code{"pulse"})
26750 The type of audio output.
26752 @item @code{enabled?} (default: @code{#t})
26753 Specifies whether this audio output is enabled when MPD is started. By
26754 default, all audio outputs are enabled. This is just the default
26755 setting when there is no state file; with a state file, the previous
26758 @item @code{tags?} (default: @code{#t})
26759 If set to @code{#f}, then MPD will not send tags to this output. This
26760 is only useful for output plugins that can receive tags, for example the
26761 @code{httpd} output plugin.
26763 @item @code{always-on?} (default: @code{#f})
26764 If set to @code{#t}, then MPD attempts to keep this audio output always
26765 open. This may be useful for streaming servers, when you don’t want to
26766 disconnect all listeners even when playback is accidentally stopped.
26768 @item @code{mixer-type}
26769 This field accepts a symbol that specifies which mixer should be used
26770 for this audio output: the @code{hardware} mixer, the @code{software}
26771 mixer, the @code{null} mixer (allows setting the volume, but with no
26772 effect; this can be used as a trick to implement an external mixer
26773 External Mixer) or no mixer (@code{none}).
26775 @item @code{extra-options} (default: @code{'()})
26776 An association list of option symbols to string values to be appended to
26777 the audio output configuration.
26782 The following example shows a configuration of @code{mpd} that provides
26783 an HTTP audio streaming output.
26786 (service mpd-service-type
26794 `((encoder . "vorbis")
26795 (port . "8080"))))))))
26799 @node Virtualization Services
26800 @subsection Virtualization Services
26802 The @code{(gnu services virtualization)} module provides services for
26803 the libvirt and virtlog daemons, as well as other virtualization-related
26806 @subsubheading Libvirt daemon
26808 @code{libvirtd} is the server side daemon component of the libvirt
26809 virtualization management system. This daemon runs on host servers
26810 and performs required management tasks for virtualized guests.
26812 @deffn {Scheme Variable} libvirt-service-type
26813 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
26814 Its value must be a @code{libvirt-configuration}.
26817 (service libvirt-service-type
26818 (libvirt-configuration
26819 (unix-sock-group "libvirt")
26820 (tls-port "16555")))
26824 @c Auto-generated with (generate-libvirt-documentation)
26825 Available @code{libvirt-configuration} fields are:
26827 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
26832 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
26833 Flag listening for secure TLS connections on the public TCP/IP port.
26834 You must set @code{listen} for this to have any effect.
26836 It is necessary to setup a CA and issue server certificates before using
26839 Defaults to @samp{#t}.
26843 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
26844 Listen for unencrypted TCP connections on the public TCP/IP port. You must
26845 set @code{listen} for this to have any effect.
26847 Using the TCP socket requires SASL authentication by default. Only SASL
26848 mechanisms which support data encryption are allowed. This is
26849 DIGEST_MD5 and GSSAPI (Kerberos5).
26851 Defaults to @samp{#f}.
26855 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
26856 Port for accepting secure TLS connections. This can be a port number,
26859 Defaults to @samp{"16514"}.
26863 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
26864 Port for accepting insecure TCP connections. This can be a port number,
26867 Defaults to @samp{"16509"}.
26871 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
26872 IP address or hostname used for client connections.
26874 Defaults to @samp{"0.0.0.0"}.
26878 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
26879 Flag toggling mDNS advertisement of the libvirt service.
26881 Alternatively can disable for all services on a host by stopping the
26884 Defaults to @samp{#f}.
26888 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
26889 Default mDNS advertisement name. This must be unique on the immediate
26892 Defaults to @samp{"Virtualization Host <hostname>"}.
26896 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
26897 UNIX domain socket group ownership. This can be used to allow a
26898 'trusted' set of users access to management capabilities without
26901 Defaults to @samp{"root"}.
26905 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
26906 UNIX socket permissions for the R/O socket. This is used for monitoring
26909 Defaults to @samp{"0777"}.
26913 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
26914 UNIX socket permissions for the R/W socket. Default allows only root.
26915 If PolicyKit is enabled on the socket, the default will change to allow
26916 everyone (eg, 0777)
26918 Defaults to @samp{"0770"}.
26922 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
26923 UNIX socket permissions for the admin socket. Default allows only owner
26924 (root), do not change it unless you are sure to whom you are exposing
26927 Defaults to @samp{"0777"}.
26931 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
26932 The directory in which sockets will be found/created.
26934 Defaults to @samp{"/var/run/libvirt"}.
26938 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
26939 Authentication scheme for UNIX read-only sockets. By default socket
26940 permissions allow anyone to connect
26942 Defaults to @samp{"polkit"}.
26946 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
26947 Authentication scheme for UNIX read-write sockets. By default socket
26948 permissions only allow root. If PolicyKit support was compiled into
26949 libvirt, the default will be to use 'polkit' auth.
26951 Defaults to @samp{"polkit"}.
26955 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
26956 Authentication scheme for TCP sockets. If you don't enable SASL, then
26957 all TCP traffic is cleartext. Don't do this outside of a dev/test
26960 Defaults to @samp{"sasl"}.
26964 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
26965 Authentication scheme for TLS sockets. TLS sockets already have
26966 encryption provided by the TLS layer, and limited authentication is done
26969 It is possible to make use of any SASL authentication mechanism as well,
26970 by using 'sasl' for this option
26972 Defaults to @samp{"none"}.
26976 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
26977 API access control scheme.
26979 By default an authenticated user is allowed access to all APIs. Access
26980 drivers can place restrictions on this.
26982 Defaults to @samp{()}.
26986 @deftypevr {@code{libvirt-configuration} parameter} string key-file
26987 Server key file path. If set to an empty string, then no private key is
26990 Defaults to @samp{""}.
26994 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
26995 Server key file path. If set to an empty string, then no certificate is
26998 Defaults to @samp{""}.
27002 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
27003 Server key file path. If set to an empty string, then no CA certificate
27006 Defaults to @samp{""}.
27010 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
27011 Certificate revocation list path. If set to an empty string, then no
27014 Defaults to @samp{""}.
27018 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
27019 Disable verification of our own server certificates.
27021 When libvirtd starts it performs some sanity checks against its own
27024 Defaults to @samp{#f}.
27028 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
27029 Disable verification of client certificates.
27031 Client certificate verification is the primary authentication mechanism.
27032 Any client which does not present a certificate signed by the CA will be
27035 Defaults to @samp{#f}.
27039 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
27040 Whitelist of allowed x509 Distinguished Name.
27042 Defaults to @samp{()}.
27046 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
27047 Whitelist of allowed SASL usernames. The format for username depends on
27048 the SASL authentication mechanism.
27050 Defaults to @samp{()}.
27054 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
27055 Override the compile time default TLS priority string. The default is
27056 usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
27057 is desired for libvirt to deviate from the global default settings.
27059 Defaults to @samp{"NORMAL"}.
27063 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
27064 Maximum number of concurrent client connections to allow over all
27067 Defaults to @samp{5000}.
27071 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
27072 Maximum length of queue of connections waiting to be accepted by the
27073 daemon. Note, that some protocols supporting retransmission may obey
27074 this so that a later reattempt at connection succeeds.
27076 Defaults to @samp{1000}.
27080 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
27081 Maximum length of queue of accepted but not yet authenticated clients.
27082 Set this to zero to turn this feature off
27084 Defaults to @samp{20}.
27088 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
27089 Number of workers to start up initially.
27091 Defaults to @samp{5}.
27095 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
27096 Maximum number of worker threads.
27098 If the number of active clients exceeds @code{min-workers}, then more
27099 threads are spawned, up to max_workers limit. Typically you'd want
27100 max_workers to equal maximum number of clients allowed.
27102 Defaults to @samp{20}.
27106 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
27107 Number of priority workers. If all workers from above pool are stuck,
27108 some calls marked as high priority (notably domainDestroy) can be
27109 executed in this pool.
27111 Defaults to @samp{5}.
27115 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
27116 Total global limit on concurrent RPC calls.
27118 Defaults to @samp{20}.
27122 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
27123 Limit on concurrent requests from a single client connection. To avoid
27124 one client monopolizing the server this should be a small fraction of
27125 the global max_requests and max_workers parameter.
27127 Defaults to @samp{5}.
27131 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
27132 Same as @code{min-workers} but for the admin interface.
27134 Defaults to @samp{1}.
27138 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
27139 Same as @code{max-workers} but for the admin interface.
27141 Defaults to @samp{5}.
27145 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
27146 Same as @code{max-clients} but for the admin interface.
27148 Defaults to @samp{5}.
27152 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
27153 Same as @code{max-queued-clients} but for the admin interface.
27155 Defaults to @samp{5}.
27159 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
27160 Same as @code{max-client-requests} but for the admin interface.
27162 Defaults to @samp{5}.
27166 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
27167 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
27169 Defaults to @samp{3}.
27173 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
27176 A filter allows to select a different logging level for a given category
27177 of logs. The format for a filter is one of:
27188 where @code{name} is a string which is matched against the category
27189 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
27190 file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
27191 name in the filter can be a substring of the full category name, in
27192 order to match multiple similar categories), the optional @samp{"+"}
27193 prefix tells libvirt to log stack trace for each message matching name,
27194 and @code{x} is the minimal level where matching messages should be
27212 Multiple filters can be defined in a single filters statement, they just
27213 need to be separated by spaces.
27215 Defaults to @samp{"3:remote 4:event"}.
27219 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
27222 An output is one of the places to save logging information. The format
27223 for an output can be:
27227 output goes to stderr
27229 @item x:syslog:name
27230 use syslog for the output and use the given name as the ident
27232 @item x:file:file_path
27233 output to a file, with the given filepath
27236 output to journald logging system
27240 In all case the x prefix is the minimal level, acting as a filter
27257 Multiple outputs can be defined, they just need to be separated by
27260 Defaults to @samp{"3:stderr"}.
27264 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
27265 Allows usage of the auditing subsystem to be altered
27269 0: disable all auditing
27272 1: enable auditing, only if enabled on host
27275 2: enable auditing, and exit if disabled on host.
27279 Defaults to @samp{1}.
27283 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
27284 Send audit messages via libvirt logging infrastructure.
27286 Defaults to @samp{#f}.
27290 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
27291 Host UUID@. UUID must not have all digits be the same.
27293 Defaults to @samp{""}.
27297 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
27298 Source to read host UUID.
27302 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
27305 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
27309 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
27312 Defaults to @samp{"smbios"}.
27316 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
27317 A keepalive message is sent to a client after @code{keepalive_interval}
27318 seconds of inactivity to check if the client is still responding. If
27319 set to -1, libvirtd will never send keepalive requests; however clients
27320 can still send them and the daemon will send responses.
27322 Defaults to @samp{5}.
27326 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
27327 Maximum number of keepalive messages that are allowed to be sent to the
27328 client without getting any response before the connection is considered
27331 In other words, the connection is automatically closed approximately
27332 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
27333 the last message received from the client. When @code{keepalive-count}
27334 is set to 0, connections will be automatically closed after
27335 @code{keepalive-interval} seconds of inactivity without sending any
27336 keepalive messages.
27338 Defaults to @samp{5}.
27342 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
27343 Same as above but for admin interface.
27345 Defaults to @samp{5}.
27349 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
27350 Same as above but for admin interface.
27352 Defaults to @samp{5}.
27356 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
27357 Timeout for Open vSwitch calls.
27359 The @code{ovs-vsctl} utility is used for the configuration and its
27360 timeout option is set by default to 5 seconds to avoid potential
27361 infinite waits blocking libvirt.
27363 Defaults to @samp{5}.
27367 @c %end of autogenerated docs
27369 @subsubheading Virtlog daemon
27370 The virtlogd service is a server side daemon component of libvirt that is
27371 used to manage logs from virtual machine consoles.
27373 This daemon is not used directly by libvirt client applications, rather it
27374 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
27375 standalone daemon, the main @code{libvirtd} daemon can be restarted without
27376 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
27377 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
27379 @deffn {Scheme Variable} virtlog-service-type
27380 This is the type of the virtlog daemon.
27381 Its value must be a @code{virtlog-configuration}.
27384 (service virtlog-service-type
27385 (virtlog-configuration
27386 (max-clients 1000)))
27390 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
27391 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
27393 Defaults to @samp{3}.
27397 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
27400 A filter allows to select a different logging level for a given category
27401 of logs The format for a filter is one of:
27412 where @code{name} is a string which is matched against the category
27413 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
27414 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
27415 be a substring of the full category name, in order to match multiple
27416 similar categories), the optional "+" prefix tells libvirt to log stack
27417 trace for each message matching name, and @code{x} is the minimal level
27418 where matching messages should be logged:
27435 Multiple filters can be defined in a single filters statement, they just
27436 need to be separated by spaces.
27438 Defaults to @samp{"3:remote 4:event"}.
27442 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
27445 An output is one of the places to save logging information The format
27446 for an output can be:
27450 output goes to stderr
27452 @item x:syslog:name
27453 use syslog for the output and use the given name as the ident
27455 @item x:file:file_path
27456 output to a file, with the given filepath
27459 output to journald logging system
27463 In all case the x prefix is the minimal level, acting as a filter
27480 Multiple outputs can be defined, they just need to be separated by
27483 Defaults to @samp{"3:stderr"}.
27487 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
27488 Maximum number of concurrent client connections to allow over all
27491 Defaults to @samp{1024}.
27495 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
27496 Maximum file size before rolling over.
27498 Defaults to @samp{2MB}
27502 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
27503 Maximum number of backup files to keep.
27505 Defaults to @samp{3}
27509 @anchor{transparent-emulation-qemu}
27510 @subsubheading Transparent Emulation with QEMU
27513 @cindex @code{binfmt_misc}
27514 @code{qemu-binfmt-service-type} provides support for transparent
27515 emulation of program binaries built for different architectures---e.g.,
27516 it allows you to transparently execute an ARMv7 program on an x86_64
27517 machine. It achieves this by combining the @uref{https://www.qemu.org,
27518 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
27519 This feature only allows you to emulate GNU/Linux on a different
27520 architecture, but see below for GNU/Hurd support.
27522 @defvr {Scheme Variable} qemu-binfmt-service-type
27523 This is the type of the QEMU/binfmt service for transparent emulation.
27524 Its value must be a @code{qemu-binfmt-configuration} object, which
27525 specifies the QEMU package to use as well as the architecture we want to
27529 (service qemu-binfmt-service-type
27530 (qemu-binfmt-configuration
27531 (platforms (lookup-qemu-platforms "arm" "aarch64"))))
27534 In this example, we enable transparent emulation for the ARM and aarch64
27535 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
27536 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
27537 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
27540 @deftp {Data Type} qemu-binfmt-configuration
27541 This is the configuration for the @code{qemu-binfmt} service.
27544 @item @code{platforms} (default: @code{'()})
27545 The list of emulated QEMU platforms. Each item must be a @dfn{platform
27546 object} as returned by @code{lookup-qemu-platforms} (see below).
27548 @item @code{guix-support?} (default: @code{#t})
27549 When it is true, QEMU and all its dependencies are added to the build
27550 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
27551 @option{--chroot-directory} option}). This allows the @code{binfmt_misc}
27552 handlers to be used within the build environment, which in turn means
27553 that you can transparently build programs for another architecture.
27555 For example, let's suppose you're on an x86_64 machine and you have this
27559 (service qemu-binfmt-service-type
27560 (qemu-binfmt-configuration
27561 (platforms (lookup-qemu-platforms "arm"))
27562 (guix-support? #t)))
27568 guix build -s armhf-linux inkscape
27572 and it will build Inkscape for ARMv7 @emph{as if it were a native
27573 build}, transparently using QEMU to emulate the ARMv7 CPU@. Pretty handy
27574 if you'd like to test a package build for an architecture you don't have
27577 When @code{guix-support?} is set to @code{#f}, programs for other
27578 architectures can still be executed transparently, but invoking commands
27579 like @command{guix build -s armhf-linux @dots{}} will fail.
27581 @item @code{qemu} (default: @code{qemu})
27582 The QEMU package to use.
27586 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
27587 Return the list of QEMU platform objects corresponding to
27588 @var{platforms}@dots{}. @var{platforms} must be a list of strings
27589 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
27590 @code{"mips64el"}, and so on.
27593 @deffn {Scheme Procedure} qemu-platform? @var{obj}
27594 Return true if @var{obj} is a platform object.
27597 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
27598 Return the name of @var{platform}---a string such as @code{"arm"}.
27602 @subsubheading The Hurd in a Virtual Machine
27604 @cindex @code{hurd}
27608 Service @code{hurd-vm} provides support for running GNU/Hurd in a
27609 virtual machine (VM), a so-called @dfn{childhurd}. This service is meant
27610 to be used on GNU/Linux and the given GNU/Hurd operating system
27611 configuration is cross-compiled. The virtual machine is a Shepherd
27612 service that can be referred to by the names @code{hurd-vm} and
27613 @code{childhurd} and be controlled with commands such as:
27617 herd stop childhurd
27620 When the service is running, you can view its console by connecting to
27621 it with a VNC client, for example with:
27624 guix environment --ad-hoc tigervnc-client -- \
27625 vncviewer localhost:5900
27628 The default configuration (see @code{hurd-vm-configuration} below)
27629 spawns a secure shell (SSH) server in your GNU/Hurd system, which QEMU
27630 (the virtual machine emulator) redirects to port 10222 on the host.
27631 Thus, you can connect over SSH to the childhurd with:
27634 ssh root@@localhost -p 10022
27637 The childhurd is volatile and stateless: it starts with a fresh root
27638 file system every time you restart it. By default though, all the files
27639 under @file{/etc/childhurd} on the host are copied as is to the root
27640 file system of the childhurd when it boots. This allows you to
27641 initialize ``secrets'' inside the VM: SSH host keys, authorized
27642 substitute keys, and so on---see the explanation of @code{secret-root}
27645 @defvr {Scheme Variable} hurd-vm-service-type
27646 This is the type of the Hurd in a Virtual Machine service. Its value
27647 must be a @code{hurd-vm-configuration} object, which specifies the
27648 operating system (@pxref{operating-system Reference}) and the disk size
27649 for the Hurd Virtual Machine, the QEMU package to use as well as the
27650 options for running it.
27655 (service hurd-vm-service-type
27656 (hurd-vm-configuration
27657 (disk-size (* 5000 (expt 2 20))) ;5G
27658 (memory-size 1024))) ;1024MiB
27661 would create a disk image big enough to build GNU@tie{}Hello, with some
27665 @deftp {Data Type} hurd-vm-configuration
27666 The data type representing the configuration for
27667 @code{hurd-vm-service-type}.
27670 @item @code{os} (default: @var{%hurd-vm-operating-system})
27671 The operating system to instantiate. This default is bare-bones with a
27672 permissive OpenSSH secure shell daemon listening on port 2222
27673 (@pxref{Networking Services, @code{openssh-service-type}}).
27675 @item @code{qemu} (default: @code{qemu-minimal})
27676 The QEMU package to use.
27678 @item @code{image} (default: @var{hurd-vm-disk-image})
27679 The procedure used to build the disk-image built from this
27682 @item @code{disk-size} (default: @code{'guess})
27683 The size of the disk image.
27685 @item @code{memory-size} (default: @code{512})
27686 The memory size of the Virtual Machine in mebibytes.
27688 @item @code{options} (default: @code{'("--snapshot")})
27689 The extra options for running QEMU.
27691 @item @code{id} (default: @code{#f})
27692 If set, a non-zero positive integer used to parameterize Childhurd
27693 instances. It is appended to the service's name,
27694 e.g. @code{childhurd1}.
27696 @item @code{net-options} (default: @var{hurd-vm-net-options})
27697 The procedure used to produce the list of QEMU networking options.
27699 By default, it produces
27702 '("--device" "rtl8139,netdev=net0"
27703 "--netdev" "user,id=net0\
27704 ,hostfwd=tcp:127.0.0.1:@var{secrets-port}-:1004\
27705 ,hostfwd=tcp:127.0.0.1:@var{ssh-port}-:2222\
27706 ,hostfwd=tcp:127.0.0.1:@var{vnc-port}-:5900")
27709 with forwarded ports:
27712 @var{secrets-port}: @code{(+ 11004 (* 1000 @var{ID}))}
27713 @var{ssh-port}: @code{(+ 10022 (* 1000 @var{ID}))}
27714 @var{vnc-port}: @code{(+ 15900 (* 1000 @var{ID}))}
27717 @item @code{secret-root} (default: @file{/etc/childhurd})
27718 The root directory with out-of-band secrets to be installed into the
27719 childhurd once it runs. Childhurds are volatile which means that on
27720 every startup, secrets such as the SSH host keys and Guix signing key
27723 If the @file{/etc/childhurd} directory does not exist, the
27724 @code{secret-service} running in the Childhurd will be sent an empty
27727 By default, the service automatically populates @file{/etc/childhurd}
27728 with the following non-volatile secrets, unless they already exist:
27731 /etc/childhurd/etc/guix/acl
27732 /etc/childhurd/etc/guix/signing-key.pub
27733 /etc/childhurd/etc/guix/signing-key.sec
27734 /etc/childhurd/etc/ssh/ssh_host_ed25519_key
27735 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key
27736 /etc/childhurd/etc/ssh/ssh_host_ed25519_key.pub
27737 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key.pub
27740 These files are automatically sent to the guest Hurd VM when it boots,
27741 including permissions.
27743 @cindex childhurd, offloading
27744 @cindex Hurd, offloading
27745 Having these files in place means that only a couple of things are
27746 missing to allow the host to offload @code{i586-gnu} builds to the
27751 Authorizing the childhurd's key on the host so that the host accepts
27752 build results coming from the childhurd, which can be done like so:
27755 guix archive --authorize < \
27756 /etc/childhurd/etc/guix/signing-key.pub
27760 Adding the childhurd to @file{/etc/guix/machines.scm} (@pxref{Daemon
27764 We're working towards making that happen automatically---get in touch
27765 with us at @email{guix-devel@@gnu.org} to discuss it!
27769 Note that by default the VM image is volatile, i.e., once stopped the
27770 contents are lost. If you want a stateful image instead, override the
27771 configuration's @code{image} and @code{options} without
27772 the @code{--snapshot} flag using something along these lines:
27775 (service hurd-vm-service-type
27776 (hurd-vm-configuration
27777 (image (const "/out/of/store/writable/hurd.img"))
27781 @subsubheading Ganeti
27786 This service is considered experimental. Configuration options may be changed
27787 in a backwards-incompatible manner, and not all features have been thorougly
27788 tested. Users of this service are encouraged to share their experience at
27789 @email{guix-devel@@gnu.org}.
27792 Ganeti is a virtual machine management system. It is designed to keep virtual
27793 machines running on a cluster of servers even in the event of hardware failures,
27794 and to make maintenance and recovery tasks easy. It consists of multiple
27795 services which are described later in this section. In addition to the Ganeti
27796 service, you will need the OpenSSH service (@pxref{Networking Services,
27797 @code{openssh-service-type}}), and update the @file{/etc/hosts} file
27798 (@pxref{operating-system Reference, @code{hosts-file}}) with the cluster name
27799 and address (or use a DNS server).
27801 All nodes participating in a Ganeti cluster should have the same Ganeti and
27802 @file{/etc/hosts} configuration. Here is an example configuration for a Ganeti
27803 cluster node that supports multiple storage backends, and installs the
27804 @code{debootstrap} and @code{guix} @dfn{OS providers}:
27807 (use-package-modules virtualization)
27808 (use-service-modules base ganeti networking ssh)
27811 (host-name "node1")
27812 (hosts-file (plain-file "hosts" (format #f "
27813 127.0.0.1 localhost
27816 192.168.1.200 ganeti.example.com
27817 192.168.1.201 node1.example.com node1
27818 192.168.1.202 node2.example.com node2
27821 ;; Install QEMU so we can use KVM-based instances, and LVM, DRBD and Ceph
27822 ;; in order to use the "plain", "drbd" and "rbd" storage backends.
27823 (packages (append (map specification->package
27824 '("qemu" "lvm2" "drbd-utils" "ceph"
27825 ;; Add the debootstrap and guix OS providers.
27826 "ganeti-instance-guix" "ganeti-instance-debootstrap"))
27829 (append (list (static-networking-service "eth0" "192.168.1.201"
27830 #:netmask "255.255.255.0"
27831 #:gateway "192.168.1.254"
27832 #:name-servers '("192.168.1.252"
27835 ;; Ganeti uses SSH to communicate between nodes.
27836 (service openssh-service-type
27837 (openssh-configuration
27838 (permit-root-login 'without-password)))
27840 (service ganeti-service-type
27841 (ganeti-configuration
27842 ;; This list specifies allowed file system paths
27843 ;; for storing virtual machine images.
27844 (file-storage-paths '("/srv/ganeti/file-storage"))
27845 ;; This variable configures a single "variant" for
27846 ;; both Debootstrap and Guix that works with KVM.
27847 (os %default-ganeti-os))))
27851 Users are advised to read the
27852 @url{http://docs.ganeti.org/ganeti/master/html/admin.html,Ganeti
27853 administrators guide} to learn about the various cluster options and
27854 day-to-day operations. There is also a
27855 @url{https://guix.gnu.org/blog/2020/running-a-ganeti-cluster-on-guix/,blog post}
27856 describing how to configure and initialize a small cluster.
27858 @defvr {Scheme Variable} ganeti-service-type
27859 This is a service type that includes all the various services that Ganeti
27862 Its value is a @code{ganeti-configuration} object that defines the package
27863 to use for CLI operations, as well as configuration for the various daemons.
27864 Allowed file storage paths and available guest operating systems are also
27865 configured through this data type.
27868 @deftp {Data Type} ganeti-configuration
27869 The @code{ganeti} service takes the following configuration options:
27872 @item @code{ganeti} (default: @code{ganeti})
27873 The @code{ganeti} package to use. It will be installed to the system profile
27874 and make @command{gnt-cluster}, @command{gnt-instance}, etc available. Note
27875 that the value specified here does not affect the other services as each refer
27876 to a specific @code{ganeti} package (see below).
27878 @item @code{noded-configuration} (default: @code{(ganeti-noded-configuration)})
27879 @itemx @code{confd-configuration} (default: @code{(ganeti-confd-configuration)})
27880 @itemx @code{wconfd-configuration} (default: @code{(ganeti-wconfd-configuration)})
27881 @itemx @code{luxid-configuration} (default: @code{(ganeti-luxid-configuration)})
27882 @itemx @code{rapi-configuration} (default: @code{(ganeti-rapi-configuration)})
27883 @itemx @code{kvmd-configuration} (default: @code{(ganeti-kvmd-configuration)})
27884 @itemx @code{mond-configuration} (default: @code{(ganeti-mond-configuration)})
27885 @itemx @code{metad-configuration} (default: @code{(ganeti-metad-configuration)})
27886 @itemx @code{watcher-configuration} (default: @code{(ganeti-watcher-configuration)})
27887 @itemx @code{cleaner-configuration} (default: @code{(ganeti-cleaner-configuration)})
27889 These options control the various daemons and cron jobs that are distributed
27890 with Ganeti. The possible values for these are described in detail below.
27891 To override a setting, you must use the configuration type for that service:
27894 (service ganeti-service-type
27895 (ganeti-configuration
27896 (rapi-configuration
27897 (ganeti-rapi-configuration
27898 (interface "eth1"))))
27899 (watcher-configuration
27900 (ganeti-watcher-configuration
27901 (rapi-ip "10.0.0.1"))))
27904 @item @code{file-storage-paths} (default: @code{'()})
27905 List of allowed directories for file storage backend.
27907 @item @code{os} (default: @code{%default-ganeti-os})
27908 List of @code{<ganeti-os>} records.
27911 In essence @code{ganeti-service-type} is shorthand for declaring each service
27915 (service ganeti-noded-service-type)
27916 (service ganeti-confd-service-type)
27917 (service ganeti-wconfd-service-type)
27918 (service ganeti-luxid-service-type)
27919 (service ganeti-kvmd-service-type)
27920 (service ganeti-mond-service-type)
27921 (service ganeti-metad-service-type)
27922 (service ganeti-watcher-service-type)
27923 (service ganeti-cleaner-service-type)
27926 Plus a service extension for @code{etc-service-type} that configures the file
27927 storage backend and OS variants.
27931 @deftp {Data Type} ganeti-os
27932 This data type is suitable for passing to the @code{os} parameter of
27933 @code{ganeti-configuration}. It takes the following parameters:
27937 The name for this OS provider. It is only used to specify where the
27938 configuration ends up. Setting it to ``debootstrap'' will create
27939 @file{/etc/ganeti/instance-debootstrap}.
27941 @item @code{extension}
27942 The file extension for variants of this OS type. For example
27943 @file{.conf} or @file{.scm}.
27945 @item @code{variants} (default: @code{'()})
27946 List of @code{ganeti-os-variant} objects for this OS.
27951 @deftp {Data Type} ganeti-os-variant
27952 This is the data type for a Ganeti OS variant. It takes the following
27957 The name of this variant.
27959 @item @code{configuration}
27960 A configuration file for this variant.
27964 @defvr {Scheme Variable} %default-debootstrap-hooks
27965 This variable contains hooks to configure networking and the GRUB bootloader.
27968 @defvr {Scheme Variable} %default-debootstrap-extra-pkgs
27969 This variable contains a list of packages suitable for a fully-virtualized guest.
27972 @deftp {Data Type} debootstrap-configuration
27974 This data type creates configuration files suitable for the debootstrap OS provider.
27977 @item @code{hooks} (default: @code{%default-debootstrap-hooks})
27978 When not @code{#f}, this must be a G-expression that specifies a directory with
27979 scripts that will run when the OS is installed. It can also be a list of
27980 @code{(name . file-like)} pairs. For example:
27983 `((99-hello-world . ,(plain-file "#!/bin/sh\necho Hello, World")))
27986 That will create a directory with one executable named @code{99-hello-world}
27987 and run it every time this variant is installed. If set to @code{#f}, hooks
27988 in @file{/etc/ganeti/instance-debootstrap/hooks} will be used, if any.
27989 @item @code{proxy} (default: @code{#f})
27990 Optional HTTP proxy to use.
27991 @item @code{mirror} (default: @code{#f})
27992 The Debian mirror. Typically something like @code{http://ftp.no.debian.org/debian}.
27993 The default varies depending on the distribution.
27994 @item @code{arch} (default: @code{#f})
27995 The dpkg architecture. Set to @code{armhf} to debootstrap an ARMv7 instance
27996 on an AArch64 host. Default is to use the current system architecture.
27997 @item @code{suite} (default: @code{"stable"})
27998 When set, this must be a Debian distribution ``suite'' such as @code{buster}
27999 or @code{focal}. If set to @code{#f}, the default for the OS provider is used.
28000 @item @code{extra-pkgs} (default: @code{%default-debootstrap-extra-pkgs})
28001 List of extra packages that will get installed by dpkg in addition
28002 to the minimal system.
28003 @item @code{components} (default: @code{#f})
28004 When set, must be a list of Debian repository ``components''. For example
28005 @code{'("main" "contrib")}.
28006 @item @code{generate-cache?} (default: @code{#t})
28007 Whether to automatically cache the generated debootstrap archive.
28008 @item @code{clean-cache} (default: @code{14})
28009 Discard the cache after this amount of days. Use @code{#f} to never
28011 @item @code{partition-style} (default: @code{'msdos})
28012 The type of partition to create. When set, it must be one of
28013 @code{'msdos}, @code{'none} or a string.
28014 @item @code{partition-alignment} (default: @code{2048})
28015 Alignment of the partition in sectors.
28019 @deffn {Scheme Procedure} debootstrap-variant @var{name} @var{configuration}
28020 This is a helper procedure that creates a @code{ganeti-os-variant} record. It
28021 takes two parameters: a name and a @code{debootstrap-configuration} object.
28024 @deffn {Scheme Procedure} debootstrap-os @var{variants}@dots{}
28025 This is a helper procedure that creates a @code{ganeti-os} record. It takes
28026 a list of variants created with @code{debootstrap-variant}.
28029 @deffn {Scheme Procedure} guix-variant @var{name} @var{configuration}
28030 This is a helper procedure that creates a @code{ganeti-os-variant} record for
28031 use with the Guix OS provider. It takes a name and a G-expression that returns
28032 a ``file-like'' (@pxref{G-Expressions, file-like objects}) object containing a
28033 Guix System configuration.
28036 @deffn {Scheme Procedure} guix-os @var{variants}@dots{}
28037 This is a helper procedure that creates a @code{ganeti-os} record. It
28038 takes a list of variants produced by @code{guix-variant}.
28041 @defvr {Scheme Variable} %default-debootstrap-variants
28042 This is a convenience variable to make the debootstrap provider work
28043 ``out of the box'' without users having to declare variants manually. It
28044 contains a single debootstrap variant with the default configuration:
28047 (list (debootstrap-variant
28049 (debootstrap-configuration)))
28053 @defvr {Scheme Variable} %default-guix-variants
28054 This is a convenience variable to make the Guix OS provider work without
28055 additional configuration. It creates a virtual machine that has an SSH
28056 server, a serial console, and authorizes the Ganeti hosts SSH keys.
28059 (list (guix-variant
28061 (file-append ganeti-instance-guix
28062 "/share/doc/ganeti-instance-guix/examples/dynamic.scm")))
28066 Users can implement support for OS providers unbeknownst to Guix by extending
28067 the @code{ganeti-os} and @code{ganeti-os-variant} records appropriately.
28073 (extension ".conf")
28075 (list (ganeti-os-variant
28077 (configuration (plain-file "bar" "this is fine"))))))
28080 That creates @file{/etc/ganeti/instance-custom/variants/foo.conf} which points
28081 to a file in the store with contents @code{this is fine}. It also creates
28082 @file{/etc/ganeti/instance-custom/variants/variants.list} with contents @code{foo}.
28084 Obviously this may not work for all OS providers out there. If you find the
28085 interface limiting, please reach out to @email{guix-devel@@gnu.org}.
28087 The rest of this section documents the various services that are included by
28088 @code{ganeti-service-type}.
28090 @defvr {Scheme Variable} ganeti-noded-service-type
28091 @command{ganeti-noded} is the daemon responsible for node-specific functions
28092 within the Ganeti system. The value of this service must be a
28093 @code{ganeti-noded-configuration} object.
28096 @deftp {Data Type} ganeti-noded-configuration
28097 This is the configuration for the @code{ganeti-noded} service.
28100 @item @code{ganeti} (default: @code{ganeti})
28101 The @code{ganeti} package to use for this service.
28103 @item @code{port} (default: @code{1811})
28104 The TCP port on which the node daemon listens for network requests.
28106 @item @code{address} (default: @code{"0.0.0.0"})
28107 The network address that the daemon will bind to. The default address means
28108 bind to all available addresses.
28110 @item @code{interface} (default: @code{#f})
28111 When this is set, it must be a specific network interface (e.g.@: @code{eth0})
28112 that the daemon will bind to.
28114 @item @code{max-clients} (default: @code{20})
28115 This sets a limit on the maximum number of simultaneous client connections
28116 that the daemon will handle. Connections above this count are accepted, but
28117 no responses will be sent until enough connections have closed.
28119 @item @code{ssl?} (default: @code{#t})
28120 Whether to use SSL/TLS to encrypt network communications. The certificate
28121 is automatically provisioned by the cluster and can be rotated with
28122 @command{gnt-cluster renew-crypto}.
28124 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
28125 This can be used to provide a specific encryption key for TLS communications.
28127 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
28128 This can be used to provide a specific certificate for TLS communications.
28130 @item @code{debug?} (default: @code{#f})
28131 When true, the daemon performs additional logging for debugging purposes.
28132 Note that this will leak encryption details to the log files, use with caution.
28137 @defvr {Scheme Variable} ganeti-confd-service-type
28138 @command{ganeti-confd} answers queries related to the configuration of a
28139 Ganeti cluster. The purpose of this daemon is to have a highly available
28140 and fast way to query cluster configuration values. It is automatically
28141 active on all @dfn{master candidates}. The value of this service must be a
28142 @code{ganeti-confd-configuration} object.
28146 @deftp {Data Type} ganeti-confd-configuration
28147 This is the configuration for the @code{ganeti-confd} service.
28150 @item @code{ganeti} (default: @code{ganeti})
28151 The @code{ganeti} package to use for this service.
28153 @item @code{port} (default: @code{1814})
28154 The UDP port on which to listen for network requests.
28156 @item @code{address} (default: @code{"0.0.0.0"})
28157 Network address that the daemon will bind to.
28159 @item @code{debug?} (default: @code{#f})
28160 When true, the daemon performs additional logging for debugging purposes.
28165 @defvr {Scheme Variable} ganeti-wconfd-service-type
28166 @command{ganeti-wconfd} is the daemon that has authoritative knowledge
28167 about the cluster configuration and is the only entity that can accept
28168 changes to it. All jobs that need to modify the configuration will do so
28169 by sending appropriate requests to this daemon. It only runs on the
28170 @dfn{master node} and will automatically disable itself on other nodes.
28172 The value of this service must be a
28173 @code{ganeti-wconfd-configuration} object.
28176 @deftp {Data Type} ganeti-wconfd-configuration
28177 This is the configuration for the @code{ganeti-wconfd} service.
28180 @item @code{ganeti} (default: @code{ganeti})
28181 The @code{ganeti} package to use for this service.
28183 @item @code{no-voting?} (default: @code{#f})
28184 The daemon will refuse to start if the majority of cluster nodes does not
28185 agree that it is running on the master node. Set to @code{#t} to start
28186 even if a quorum can not be reached (dangerous, use with caution).
28188 @item @code{debug?} (default: @code{#f})
28189 When true, the daemon performs additional logging for debugging purposes.
28194 @defvr {Scheme Variable} ganeti-luxid-service-type
28195 @command{ganeti-luxid} is a daemon used to answer queries related to the
28196 configuration and the current live state of a Ganeti cluster. Additionally,
28197 it is the authoritative daemon for the Ganeti job queue. Jobs can be
28198 submitted via this daemon and it schedules and starts them.
28200 It takes a @code{ganeti-luxid-configuration} object.
28203 @deftp {Data Type} ganeti-luxid-configuration
28204 This is the configuration for the @code{ganeti-wconfd} service.
28207 @item @code{ganeti} (default: @code{ganeti})
28208 The @code{ganeti} package to use for this service.
28210 @item @code{no-voting?} (default: @code{#f})
28211 The daemon will refuse to start if it cannot verify that the majority of
28212 cluster nodes believes that it is running on the master node. Set to
28213 @code{#t} to ignore such checks and start anyway (this can be dangerous).
28215 @item @code{debug?} (default: @code{#f})
28216 When true, the daemon performs additional logging for debugging purposes.
28221 @defvr {Scheme Variable} ganeti-rapi-service-type
28222 @command{ganeti-rapi} provides a remote API for Ganeti clusters. It runs on
28223 the master node and can be used to perform cluster actions programmatically
28224 via a JSON-based RPC protocol.
28226 Most query operations are allowed without authentication (unless
28227 @var{require-authentication?} is set), whereas write operations require
28228 explicit authorization via the @file{/var/lib/ganeti/rapi/users} file. See
28229 the @url{http://docs.ganeti.org/ganeti/master/html/rapi.html, Ganeti Remote
28230 API documentation} for more information.
28232 The value of this service must be a @code{ganeti-rapi-configuration} object.
28235 @deftp {Data Type} ganeti-rapi-configuration
28236 This is the configuration for the @code{ganeti-rapi} service.
28239 @item @code{ganeti} (default: @code{ganeti})
28240 The @code{ganeti} package to use for this service.
28242 @item @code{require-authentication?} (default: @code{#f})
28243 Whether to require authentication even for read-only operations.
28245 @item @code{port} (default: @code{5080})
28246 The TCP port on which to listen to API requests.
28248 @item @code{address} (default: @code{"0.0.0.0"})
28249 The network address that the service will bind to. By default it listens
28250 on all configured addresses.
28252 @item @code{interface} (default: @code{#f})
28253 When set, it must specify a specific network interface such as @code{eth0}
28254 that the daemon will bind to.
28256 @item @code{max-clients} (default: @code{20})
28257 The maximum number of simultaneous client requests to handle. Further
28258 connections are allowed, but no responses are sent until enough connections
28261 @item @code{ssl?} (default: @code{#t})
28262 Whether to use SSL/TLS encryption on the RAPI port.
28264 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
28265 This can be used to provide a specific encryption key for TLS communications.
28267 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
28268 This can be used to provide a specific certificate for TLS communications.
28270 @item @code{debug?} (default: @code{#f})
28271 When true, the daemon performs additional logging for debugging purposes.
28272 Note that this will leak encryption details to the log files, use with caution.
28277 @defvr {Scheme Variable} ganeti-kvmd-service-type
28278 @command{ganeti-kvmd} is responsible for determining whether a given KVM
28279 instance was shut down by an administrator or a user. Normally Ganeti will
28280 restart an instance that was not stopped through Ganeti itself. If the
28281 cluster option @code{user_shutdown} is true, this daemon monitors the
28282 @code{QMP} socket provided by QEMU and listens for shutdown events, and
28283 marks the instance as @dfn{USER_down} instead of @dfn{ERROR_down} when
28284 it shuts down gracefully by itself.
28286 It takes a @code{ganeti-kvmd-configuration} object.
28289 @deftp {Data Type} ganeti-kvmd-configuration
28292 @item @code{ganeti} (default: @code{ganeti})
28293 The @code{ganeti} package to use for this service.
28295 @item @code{debug?} (default: @code{#f})
28296 When true, the daemon performs additional logging for debugging purposes.
28301 @defvr {Scheme Variable} ganeti-mond-service-type
28302 @command{ganeti-mond} is an optional daemon that provides Ganeti monitoring
28303 functionality. It is responsible for running data collectors and publish the
28304 collected information through a HTTP interface.
28306 It takes a @code{ganeti-mond-configuration} object.
28309 @deftp {Data Type} ganeti-mond-configuration
28312 @item @code{ganeti} (default: @code{ganeti})
28313 The @code{ganeti} package to use for this service.
28315 @item @code{port} (default: @code{1815})
28316 The port on which the daemon will listen.
28318 @item @code{address} (default: @code{"0.0.0.0"})
28319 The network address that the daemon will bind to. By default it binds to all
28320 available interfaces.
28322 @item @code{debug?} (default: @code{#f})
28323 When true, the daemon performs additional logging for debugging purposes.
28328 @defvr {Scheme Variable} ganeti-metad-service-type
28329 @command{ganeti-metad} is an optional daemon that can be used to provide
28330 information about the cluster to instances or OS install scripts.
28332 It takes a @code{ganeti-metad-configuration} object.
28335 @deftp {Data Type} ganeti-metad-configuration
28338 @item @code{ganeti} (default: @code{ganeti})
28339 The @code{ganeti} package to use for this service.
28341 @item @code{port} (default: @code{80})
28342 The port on which the daemon will listen.
28344 @item @code{address} (default: @code{#f})
28345 If set, the daemon will bind to this address only. If left unset, the behavior
28346 depends on the cluster configuration.
28348 @item @code{debug?} (default: @code{#f})
28349 When true, the daemon performs additional logging for debugging purposes.
28354 @defvr {Scheme Variable} ganeti-watcher-service-type
28355 @command{ganeti-watcher} is a script designed to run periodically and ensure
28356 the health of a cluster. It will automatically restart instances that have
28357 stopped without Ganeti's consent, and repairs DRBD links in case a node has
28358 rebooted. It also archives old cluster jobs and restarts Ganeti daemons
28359 that are not running. If the cluster parameter @code{ensure_node_health}
28360 is set, the watcher will also shutdown instances and DRBD devices if the
28361 node it is running on is declared offline by known master candidates.
28363 It can be paused on all nodes with @command{gnt-cluster watcher pause}.
28365 The service takes a @code{ganeti-watcher-configuration} object.
28368 @deftp {Data Type} ganeti-watcher-configuration
28371 @item @code{ganeti} (default: @code{ganeti})
28372 The @code{ganeti} package to use for this service.
28374 @item @code{schedule} (default: @code{'(next-second-from (next-minute (range 0 60 5)))})
28375 How often to run the script. The default is every five minutes.
28377 @item @code{rapi-ip} (default: @code{#f})
28378 This option needs to be specified only if the RAPI daemon is configured to use
28379 a particular interface or address. By default the cluster address is used.
28381 @item @code{job-age} (default: @code{(* 6 3600)})
28382 Archive cluster jobs older than this age, specified in seconds. The default
28383 is 6 hours. This keeps @command{gnt-job list} manageable.
28385 @item @code{verify-disks?} (default: @code{#t})
28386 If this is @code{#f}, the watcher will not try to repair broken DRBD links
28387 automatically. Administrators will need to use @command{gnt-cluster verify-disks}
28390 @item @code{debug?} (default: @code{#f})
28391 When @code{#t}, the script performs additional logging for debugging purposes.
28396 @defvr {Scheme Variable} ganeti-cleaner-service-type
28397 @command{ganeti-cleaner} is a script designed to run periodically and remove
28398 old files from the cluster. This service type controls two @dfn{cron jobs}:
28399 one intended for the master node that permanently purges old cluster jobs,
28400 and one intended for every node that removes expired X509 certificates, keys,
28401 and outdated @command{ganeti-watcher} information. Like all Ganeti services,
28402 it is safe to include even on non-master nodes as it will disable itself as
28405 It takes a @code{ganeti-cleaner-configuration} object.
28408 @deftp {Data Type} ganeti-cleaner-configuration
28411 @item @code{ganeti} (default: @code{ganeti})
28412 The @code{ganeti} package to use for the @command{gnt-cleaner} command.
28414 @item @code{master-schedule} (default: @code{"45 1 * * *"})
28415 How often to run the master cleaning job. The default is once per day, at
28418 @item @code{node-schedule} (default: @code{"45 2 * * *"})
28419 How often to run the node cleaning job. The default is once per day, at
28425 @node Version Control Services
28426 @subsection Version Control Services
28428 The @code{(gnu services version-control)} module provides a service to
28429 allow remote access to local Git repositories. There are three options:
28430 the @code{git-daemon-service}, which provides access to repositories via
28431 the @code{git://} unsecured TCP-based protocol, extending the
28432 @code{nginx} web server to proxy some requests to
28433 @code{git-http-backend}, or providing a web interface with
28434 @code{cgit-service-type}.
28436 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
28438 Return a service that runs @command{git daemon}, a simple TCP server to
28439 expose repositories over the Git protocol for anonymous access.
28441 The optional @var{config} argument should be a
28442 @code{<git-daemon-configuration>} object, by default it allows read-only
28443 access to exported@footnote{By creating the magic file
28444 @file{git-daemon-export-ok} in the repository directory.} repositories under
28449 @deftp {Data Type} git-daemon-configuration
28450 Data type representing the configuration for @code{git-daemon-service}.
28453 @item @code{package} (default: @code{git})
28454 Package object of the Git distributed version control system.
28456 @item @code{export-all?} (default: @code{#f})
28457 Whether to allow access for all Git repositories, even if they do not
28458 have the @file{git-daemon-export-ok} file.
28460 @item @code{base-path} (default: @file{/srv/git})
28461 Whether to remap all the path requests as relative to the given path.
28462 If you run @command{git daemon} with @code{(base-path "/srv/git")} on
28463 @samp{example.com}, then if you later try to pull
28464 @indicateurl{git://example.com/hello.git}, git daemon will interpret the
28465 path as @file{/srv/git/hello.git}.
28467 @item @code{user-path} (default: @code{#f})
28468 Whether to allow @code{~user} notation to be used in requests. When
28469 specified with empty string, requests to
28470 @indicateurl{git://host/~alice/foo} is taken as a request to access
28471 @code{foo} repository in the home directory of user @code{alice}. If
28472 @code{(user-path "@var{path}")} is specified, the same request is taken
28473 as a request to access @file{@var{path}/foo} repository in the home
28474 directory of user @code{alice}.
28476 @item @code{listen} (default: @code{'()})
28477 Whether to listen on specific IP addresses or hostnames, defaults to
28480 @item @code{port} (default: @code{#f})
28481 Whether to listen on an alternative port, which defaults to 9418.
28483 @item @code{whitelist} (default: @code{'()})
28484 If not empty, only allow access to this list of directories.
28486 @item @code{extra-options} (default: @code{'()})
28487 Extra options will be passed to @command{git daemon}, please run
28488 @command{man git-daemon} for more information.
28493 The @code{git://} protocol lacks authentication. When you pull from a
28494 repository fetched via @code{git://}, you don't know whether the data you
28495 receive was modified or is even coming from the specified host, and your
28496 connection is subject to eavesdropping. It's better to use an authenticated
28497 and encrypted transport, such as @code{https}. Although Git allows you
28498 to serve repositories using unsophisticated file-based web servers,
28499 there is a faster protocol implemented by the @code{git-http-backend}
28500 program. This program is the back-end of a proper Git web service. It
28501 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
28502 on running the necessary @code{fcgiwrap} daemon.
28504 Guix has a separate configuration data type for serving Git repositories
28507 @deftp {Data Type} git-http-configuration
28508 Data type representing the configuration for a future
28509 @code{git-http-service-type}; can currently be used to configure Nginx
28510 through @code{git-http-nginx-location-configuration}.
28513 @item @code{package} (default: @var{git})
28514 Package object of the Git distributed version control system.
28516 @item @code{git-root} (default: @file{/srv/git})
28517 Directory containing the Git repositories to expose to the world.
28519 @item @code{export-all?} (default: @code{#f})
28520 Whether to expose access for all Git repositories in @var{git-root},
28521 even if they do not have the @file{git-daemon-export-ok} file.
28523 @item @code{uri-path} (default: @samp{/git/})
28524 Path prefix for Git access. With the default @samp{/git/} prefix, this
28525 will map @indicateurl{http://@var{server}/git/@var{repo}.git} to
28526 @file{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
28527 with this prefix are not passed on to this Git instance.
28529 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
28530 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
28535 There is no @code{git-http-service-type}, currently; instead you can
28536 create an @code{nginx-location-configuration} from a
28537 @code{git-http-configuration} and then add that location to a web
28540 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
28541 [config=(git-http-configuration)]
28542 Compute an @code{nginx-location-configuration} that corresponds to the
28543 given Git http configuration. An example nginx service definition to
28544 serve the default @file{/srv/git} over HTTPS might be:
28547 (service nginx-service-type
28548 (nginx-configuration
28551 (nginx-server-configuration
28552 (listen '("443 ssl"))
28553 (server-name "git.my-host.org")
28555 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
28556 (ssl-certificate-key
28557 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
28560 (git-http-nginx-location-configuration
28561 (git-http-configuration (uri-path "/"))))))))))
28564 This example assumes that you are using Let's Encrypt to get your TLS
28565 certificate. @xref{Certificate Services}. The default @code{certbot}
28566 service will redirect all HTTP traffic on @code{git.my-host.org} to
28567 HTTPS@. You will also need to add an @code{fcgiwrap} proxy to your
28568 system services. @xref{Web Services}.
28571 @subsubheading Cgit Service
28573 @cindex Cgit service
28574 @cindex Git, web interface
28575 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
28576 repositories written in C.
28578 The following example will configure the service with default values.
28579 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
28582 (service cgit-service-type)
28585 The @code{file-object} type designates either a file-like object
28586 (@pxref{G-Expressions, file-like objects}) or a string.
28588 @c %start of fragment
28590 Available @code{cgit-configuration} fields are:
28592 @deftypevr {@code{cgit-configuration} parameter} package package
28597 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
28598 NGINX configuration.
28602 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
28603 Specifies a command which will be invoked to format the content of about
28604 pages (both top-level and for each repository).
28606 Defaults to @samp{""}.
28610 @deftypevr {@code{cgit-configuration} parameter} string agefile
28611 Specifies a path, relative to each repository path, which can be used to
28612 specify the date and time of the youngest commit in the repository.
28614 Defaults to @samp{""}.
28618 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
28619 Specifies a command that will be invoked for authenticating repository
28622 Defaults to @samp{""}.
28626 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
28627 Flag which, when set to @samp{age}, enables date ordering in the branch
28628 ref list, and when set @samp{name} enables ordering by branch name.
28630 Defaults to @samp{"name"}.
28634 @deftypevr {@code{cgit-configuration} parameter} string cache-root
28635 Path used to store the cgit cache entries.
28637 Defaults to @samp{"/var/cache/cgit"}.
28641 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
28642 Number which specifies the time-to-live, in minutes, for the cached
28643 version of repository pages accessed with a fixed SHA1.
28645 Defaults to @samp{-1}.
28649 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
28650 Number which specifies the time-to-live, in minutes, for the cached
28651 version of repository pages accessed without a fixed SHA1.
28653 Defaults to @samp{5}.
28657 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
28658 Number which specifies the time-to-live, in minutes, for the cached
28659 version of the repository summary page.
28661 Defaults to @samp{5}.
28665 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
28666 Number which specifies the time-to-live, in minutes, for the cached
28667 version of the repository index page.
28669 Defaults to @samp{5}.
28673 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
28674 Number which specifies the time-to-live, in minutes, for the result of
28675 scanning a path for Git repositories.
28677 Defaults to @samp{15}.
28681 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
28682 Number which specifies the time-to-live, in minutes, for the cached
28683 version of the repository about page.
28685 Defaults to @samp{15}.
28689 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
28690 Number which specifies the time-to-live, in minutes, for the cached
28691 version of snapshots.
28693 Defaults to @samp{5}.
28697 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
28698 The maximum number of entries in the cgit cache. When set to @samp{0},
28699 caching is disabled.
28701 Defaults to @samp{0}.
28705 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
28706 Sort items in the repo list case sensitively.
28708 Defaults to @samp{#t}.
28712 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
28713 List of common prefixes which, when combined with a repository URL,
28714 generates valid clone URLs for the repository.
28716 Defaults to @samp{()}.
28720 @deftypevr {@code{cgit-configuration} parameter} list clone-url
28721 List of @code{clone-url} templates.
28723 Defaults to @samp{()}.
28727 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
28728 Command which will be invoked to format commit messages.
28730 Defaults to @samp{""}.
28734 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
28735 Flag which, when set to @samp{date}, enables strict date ordering in the
28736 commit log, and when set to @samp{topo} enables strict topological
28739 Defaults to @samp{"git log"}.
28743 @deftypevr {@code{cgit-configuration} parameter} file-object css
28744 URL which specifies the css document to include in all cgit pages.
28746 Defaults to @samp{"/share/cgit/cgit.css"}.
28750 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
28751 Specifies a command which will be invoked to format names and email
28752 address of committers, authors, and taggers, as represented in various
28753 places throughout the cgit interface.
28755 Defaults to @samp{""}.
28759 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
28760 Flag which, when set to @samp{#t}, will make cgit generate a HTML
28761 fragment suitable for embedding in other HTML pages.
28763 Defaults to @samp{#f}.
28767 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
28768 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
28769 commit history graph to the left of the commit messages in the
28770 repository log page.
28772 Defaults to @samp{#f}.
28776 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
28777 Flag which, when set to @samp{#t}, allows all filter settings to be
28778 overridden in repository-specific cgitrc files.
28780 Defaults to @samp{#f}.
28784 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
28785 Flag which, when set to @samp{#t}, allows users to follow a file in the
28788 Defaults to @samp{#f}.
28792 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
28793 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
28796 Defaults to @samp{#t}.
28800 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
28801 Flag which, when set to @samp{#t}, will make cgit generate extra links
28802 "summary", "commit", "tree" for each repo in the repository index.
28804 Defaults to @samp{#f}.
28808 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
28809 Flag which, when set to @samp{#t}, will make cgit display the owner of
28810 each repo in the repository index.
28812 Defaults to @samp{#t}.
28816 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
28817 Flag which, when set to @samp{#t}, will make cgit print the number of
28818 modified files for each commit on the repository log page.
28820 Defaults to @samp{#f}.
28824 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
28825 Flag which, when set to @samp{#t}, will make cgit print the number of
28826 added and removed lines for each commit on the repository log page.
28828 Defaults to @samp{#f}.
28832 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
28833 Flag which, when set to @code{#t}, will make cgit display remote
28834 branches in the summary and refs views.
28836 Defaults to @samp{#f}.
28840 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
28841 Flag which, when set to @code{1}, will make cgit use the subject of the
28842 parent commit as link text when generating links to parent commits in
28845 Defaults to @samp{#f}.
28849 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
28850 Flag which, when set to @samp{#t}, will make cgit use the subject of the
28851 parent commit as link text when generating links to parent commits in
28854 Defaults to @samp{#f}.
28858 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
28859 Flag which, when set to @samp{#t}, will make cgit generate linenumber
28860 links for plaintext blobs printed in the tree view.
28862 Defaults to @samp{#t}.
28866 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
28867 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
28868 set any repo specific settings.
28870 Defaults to @samp{#f}.
28874 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
28875 URL used as link to a shortcut icon for cgit.
28877 Defaults to @samp{"/favicon.ico"}.
28881 @deftypevr {@code{cgit-configuration} parameter} string footer
28882 The content of the file specified with this option will be included
28883 verbatim at the bottom of all pages (i.e.@: it replaces the standard
28884 "generated by..."@: message).
28886 Defaults to @samp{""}.
28890 @deftypevr {@code{cgit-configuration} parameter} string head-include
28891 The content of the file specified with this option will be included
28892 verbatim in the HTML HEAD section on all pages.
28894 Defaults to @samp{""}.
28898 @deftypevr {@code{cgit-configuration} parameter} string header
28899 The content of the file specified with this option will be included
28900 verbatim at the top of all pages.
28902 Defaults to @samp{""}.
28906 @deftypevr {@code{cgit-configuration} parameter} file-object include
28907 Name of a configfile to include before the rest of the current config-
28910 Defaults to @samp{""}.
28914 @deftypevr {@code{cgit-configuration} parameter} string index-header
28915 The content of the file specified with this option will be included
28916 verbatim above the repository index.
28918 Defaults to @samp{""}.
28922 @deftypevr {@code{cgit-configuration} parameter} string index-info
28923 The content of the file specified with this option will be included
28924 verbatim below the heading on the repository index page.
28926 Defaults to @samp{""}.
28930 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
28931 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
28932 in the servers timezone.
28934 Defaults to @samp{#f}.
28938 @deftypevr {@code{cgit-configuration} parameter} file-object logo
28939 URL which specifies the source of an image which will be used as a logo
28942 Defaults to @samp{"/share/cgit/cgit.png"}.
28946 @deftypevr {@code{cgit-configuration} parameter} string logo-link
28947 URL loaded when clicking on the cgit logo image.
28949 Defaults to @samp{""}.
28953 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
28954 Command which will be invoked to format the Owner column of the main
28957 Defaults to @samp{""}.
28961 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
28962 Number of items to display in atom feeds view.
28964 Defaults to @samp{10}.
28968 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
28969 Number of entries to list per page in "log" view.
28971 Defaults to @samp{50}.
28975 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
28976 Number of commit message characters to display in "log" view.
28978 Defaults to @samp{80}.
28982 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
28983 Specifies the number of entries to list per page on the repository index
28986 Defaults to @samp{50}.
28990 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
28991 Specifies the maximum number of repo description characters to display
28992 on the repository index page.
28994 Defaults to @samp{80}.
28998 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
28999 Specifies the maximum size of a blob to display HTML for in KBytes.
29001 Defaults to @samp{0}.
29005 @deftypevr {@code{cgit-configuration} parameter} string max-stats
29006 Maximum statistics period. Valid values are @samp{week},@samp{month},
29007 @samp{quarter} and @samp{year}.
29009 Defaults to @samp{""}.
29013 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
29014 Mimetype for the specified filename extension.
29016 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
29017 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
29018 "image/png") (svg "image/svg+xml"))}.
29022 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
29023 Specifies the file to use for automatic mimetype lookup.
29025 Defaults to @samp{""}.
29029 @deftypevr {@code{cgit-configuration} parameter} string module-link
29030 Text which will be used as the formatstring for a hyperlink when a
29031 submodule is printed in a directory listing.
29033 Defaults to @samp{""}.
29037 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
29038 If set to the value @samp{#t} caching will be disabled.
29040 Defaults to @samp{#f}.
29044 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
29045 If set to @samp{#t} showing full author email addresses will be
29048 Defaults to @samp{#f}.
29052 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
29053 Flag which, when set to @samp{#t}, will make cgit omit the standard
29054 header on all pages.
29056 Defaults to @samp{#f}.
29060 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
29061 A list of subdirectories inside of @code{repository-directory}, relative
29062 to it, that should loaded as Git repositories. An empty list means that
29063 all subdirectories will be loaded.
29065 Defaults to @samp{()}.
29069 @deftypevr {@code{cgit-configuration} parameter} file-object readme
29070 Text which will be used as default value for @code{cgit-repo-readme}.
29072 Defaults to @samp{""}.
29076 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
29077 If set to @code{#t} and @code{repository-directory} is enabled, if any
29078 repositories are found with a suffix of @code{.git}, this suffix will be
29079 removed for the URL and name.
29081 Defaults to @samp{#f}.
29085 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
29086 Maximum number of files to consider when detecting renames.
29088 Defaults to @samp{-1}.
29092 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
29093 The way in which repositories in each section are sorted.
29095 Defaults to @samp{""}.
29099 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
29100 Text used as content for the @code{robots} meta-tag.
29102 Defaults to @samp{("noindex" "nofollow")}.
29106 @deftypevr {@code{cgit-configuration} parameter} string root-desc
29107 Text printed below the heading on the repository index page.
29109 Defaults to @samp{"a fast webinterface for the git dscm"}.
29113 @deftypevr {@code{cgit-configuration} parameter} string root-readme
29114 The content of the file specified with this option will be included
29115 verbatim below the ``about'' link on the repository index page.
29117 Defaults to @samp{""}.
29121 @deftypevr {@code{cgit-configuration} parameter} string root-title
29122 Text printed as heading on the repository index page.
29124 Defaults to @samp{""}.
29128 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
29129 If set to @samp{#t} and repository-directory is enabled,
29130 repository-directory will recurse into directories whose name starts
29131 with a period. Otherwise, repository-directory will stay away from such
29132 directories, considered as ``hidden''. Note that this does not apply to
29133 the @file{.git} directory in non-bare repos.
29135 Defaults to @samp{#f}.
29139 @deftypevr {@code{cgit-configuration} parameter} list snapshots
29140 Text which specifies the default set of snapshot formats that cgit
29141 generates links for.
29143 Defaults to @samp{()}.
29147 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
29148 Name of the directory to scan for repositories (represents
29151 Defaults to @samp{"/srv/git"}.
29155 @deftypevr {@code{cgit-configuration} parameter} string section
29156 The name of the current repository section - all repositories defined
29157 after this option will inherit the current section name.
29159 Defaults to @samp{""}.
29163 @deftypevr {@code{cgit-configuration} parameter} string section-sort
29164 Flag which, when set to @samp{1}, will sort the sections on the
29165 repository listing by name.
29167 Defaults to @samp{""}.
29171 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
29172 A number which, if defined prior to repository-directory, specifies how
29173 many path elements from each repo path to use as a default section name.
29175 Defaults to @samp{0}.
29179 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
29180 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
29183 Defaults to @samp{#f}.
29187 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
29188 Specifies a command which will be invoked to format plaintext blobs in
29191 Defaults to @samp{""}.
29195 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
29196 Specifies the number of branches to display in the repository ``summary''
29199 Defaults to @samp{10}.
29203 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
29204 Specifies the number of log entries to display in the repository
29207 Defaults to @samp{10}.
29211 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
29212 Specifies the number of tags to display in the repository ``summary''
29215 Defaults to @samp{10}.
29219 @deftypevr {@code{cgit-configuration} parameter} string strict-export
29220 Filename which, if specified, needs to be present within the repository
29221 for cgit to allow access to that repository.
29223 Defaults to @samp{""}.
29227 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
29228 URL which, if specified, will be used as root for all cgit links.
29230 Defaults to @samp{"/"}.
29234 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
29235 A list of @dfn{cgit-repo} records to use with config.
29237 Defaults to @samp{()}.
29239 Available @code{repository-cgit-configuration} fields are:
29241 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
29242 A mask of snapshot formats for this repo that cgit generates links for,
29243 restricted by the global @code{snapshots} setting.
29245 Defaults to @samp{()}.
29249 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
29250 Override the default @code{source-filter}.
29252 Defaults to @samp{""}.
29256 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
29257 The relative URL used to access the repository.
29259 Defaults to @samp{""}.
29263 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
29264 Override the default @code{about-filter}.
29266 Defaults to @samp{""}.
29270 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
29271 Flag which, when set to @samp{age}, enables date ordering in the branch
29272 ref list, and when set to @samp{name} enables ordering by branch name.
29274 Defaults to @samp{""}.
29278 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
29279 A list of URLs which can be used to clone repo.
29281 Defaults to @samp{()}.
29285 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
29286 Override the default @code{commit-filter}.
29288 Defaults to @samp{""}.
29292 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
29293 Flag which, when set to @samp{date}, enables strict date ordering in the
29294 commit log, and when set to @samp{topo} enables strict topological
29297 Defaults to @samp{""}.
29301 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
29302 The name of the default branch for this repository. If no such branch
29303 exists in the repository, the first branch name (when sorted) is used as
29304 default instead. By default branch pointed to by HEAD, or ``master'' if
29305 there is no suitable HEAD.
29307 Defaults to @samp{""}.
29311 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
29312 The value to show as repository description.
29314 Defaults to @samp{""}.
29318 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
29319 The value to show as repository homepage.
29321 Defaults to @samp{""}.
29325 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
29326 Override the default @code{email-filter}.
29328 Defaults to @samp{""}.
29332 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
29333 A flag which can be used to disable the global setting
29334 @code{enable-commit-graph?}.
29336 Defaults to @samp{disabled}.
29340 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
29341 A flag which can be used to disable the global setting
29342 @code{enable-log-filecount?}.
29344 Defaults to @samp{disabled}.
29348 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
29349 A flag which can be used to disable the global setting
29350 @code{enable-log-linecount?}.
29352 Defaults to @samp{disabled}.
29356 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
29357 Flag which, when set to @code{#t}, will make cgit display remote
29358 branches in the summary and refs views.
29360 Defaults to @samp{disabled}.
29364 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
29365 A flag which can be used to override the global setting
29366 @code{enable-subject-links?}.
29368 Defaults to @samp{disabled}.
29372 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
29373 A flag which can be used to override the global setting
29374 @code{enable-html-serving?}.
29376 Defaults to @samp{disabled}.
29380 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
29381 Flag which, when set to @code{#t}, hides the repository from the
29384 Defaults to @samp{#f}.
29388 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
29389 Flag which, when set to @samp{#t}, ignores the repository.
29391 Defaults to @samp{#f}.
29395 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
29396 URL which specifies the source of an image which will be used as a logo
29397 on this repo’s pages.
29399 Defaults to @samp{""}.
29403 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
29404 URL loaded when clicking on the cgit logo image.
29406 Defaults to @samp{""}.
29410 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
29411 Override the default @code{owner-filter}.
29413 Defaults to @samp{""}.
29417 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
29418 Text which will be used as the formatstring for a hyperlink when a
29419 submodule is printed in a directory listing. The arguments for the
29420 formatstring are the path and SHA1 of the submodule commit.
29422 Defaults to @samp{""}.
29426 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
29427 Text which will be used as the formatstring for a hyperlink when a
29428 submodule with the specified subdirectory path is printed in a directory
29431 Defaults to @samp{()}.
29435 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
29436 Override the default maximum statistics period.
29438 Defaults to @samp{""}.
29442 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
29443 The value to show as repository name.
29445 Defaults to @samp{""}.
29449 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
29450 A value used to identify the owner of the repository.
29452 Defaults to @samp{""}.
29456 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
29457 An absolute path to the repository directory.
29459 Defaults to @samp{""}.
29463 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
29464 A path (relative to repo) which specifies a file to include verbatim as
29465 the ``About'' page for this repo.
29467 Defaults to @samp{""}.
29471 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
29472 The name of the current repository section - all repositories defined
29473 after this option will inherit the current section name.
29475 Defaults to @samp{""}.
29479 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
29480 Extra options will be appended to cgitrc file.
29482 Defaults to @samp{()}.
29488 @deftypevr {@code{cgit-configuration} parameter} list extra-options
29489 Extra options will be appended to cgitrc file.
29491 Defaults to @samp{()}.
29496 @c %end of fragment
29498 However, it could be that you just want to get a @code{cgitrc} up and
29499 running. In that case, you can pass an @code{opaque-cgit-configuration}
29500 as a record to @code{cgit-service-type}. As its name indicates, an
29501 opaque configuration does not have easy reflective capabilities.
29503 Available @code{opaque-cgit-configuration} fields are:
29505 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
29509 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
29510 The contents of the @code{cgitrc}, as a string.
29513 For example, if your @code{cgitrc} is just the empty string, you
29514 could instantiate a cgit service like this:
29517 (service cgit-service-type
29518 (opaque-cgit-configuration
29522 @subsubheading Gitolite Service
29524 @cindex Gitolite service
29525 @cindex Git, hosting
29526 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
29527 repositories on a central server.
29529 Gitolite can handle multiple repositories and users, and supports flexible
29530 configuration of the permissions for the users on the repositories.
29532 The following example will configure Gitolite using the default @code{git}
29533 user, and the provided SSH public key.
29536 (service gitolite-service-type
29537 (gitolite-configuration
29538 (admin-pubkey (plain-file
29540 "ssh-rsa AAAA... guix@@example.com"))))
29543 Gitolite is configured through a special admin repository which you can clone,
29544 for example, if you setup Gitolite on @code{example.com}, you would run the
29545 following command to clone the admin repository.
29548 git clone git@@example.com:gitolite-admin
29551 When the Gitolite service is activated, the provided @code{admin-pubkey} will
29552 be inserted in to the @file{keydir} directory in the gitolite-admin
29553 repository. If this results in a change in the repository, it will be
29554 committed using the message ``gitolite setup by GNU Guix''.
29556 @deftp {Data Type} gitolite-configuration
29557 Data type representing the configuration for @code{gitolite-service-type}.
29560 @item @code{package} (default: @var{gitolite})
29561 Gitolite package to use.
29563 @item @code{user} (default: @var{git})
29564 User to use for Gitolite. This will be user that you use when accessing
29567 @item @code{group} (default: @var{git})
29568 Group to use for Gitolite.
29570 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
29571 Directory in which to store the Gitolite configuration and repositories.
29573 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
29574 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
29575 representing the configuration for Gitolite.
29577 @item @code{admin-pubkey} (default: @var{#f})
29578 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
29579 setup Gitolite. This will be inserted in to the @file{keydir} directory
29580 within the gitolite-admin repository.
29582 To specify the SSH key as a string, use the @code{plain-file} function.
29585 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
29591 @deftp {Data Type} gitolite-rc-file
29592 Data type representing the Gitolite RC file.
29595 @item @code{umask} (default: @code{#o0077})
29596 This controls the permissions Gitolite sets on the repositories and their
29599 A value like @code{#o0027} will give read access to the group used by Gitolite
29600 (by default: @code{git}). This is necessary when using Gitolite with software
29601 like cgit or gitweb.
29603 @item @code{git-config-keys} (default: @code{""})
29604 Gitolite allows you to set git config values using the @samp{config}
29605 keyword. This setting allows control over the config keys to accept.
29607 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
29608 Set the role names allowed to be used by users running the perms command.
29610 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
29611 This setting controls the commands and features to enable within Gitolite.
29617 @node Game Services
29618 @subsection Game Services
29620 @subsubheading The Battle for Wesnoth Service
29622 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
29623 based tactical strategy game, with several single player campaigns, and
29624 multiplayer games (both networked and local).
29626 @defvar {Scheme Variable} wesnothd-service-type
29627 Service type for the wesnothd service. Its value must be a
29628 @code{wesnothd-configuration} object. To run wesnothd in the default
29629 configuration, instantiate it as:
29632 (service wesnothd-service-type)
29636 @deftp {Data Type} wesnothd-configuration
29637 Data type representing the configuration of @command{wesnothd}.
29640 @item @code{package} (default: @code{wesnoth-server})
29641 The wesnoth server package to use.
29643 @item @code{port} (default: @code{15000})
29644 The port to bind the server to.
29649 @node PAM Mount Service
29650 @subsection PAM Mount Service
29653 The @code{(gnu services pam-mount)} module provides a service allowing
29654 users to mount volumes when they log in. It should be able to mount any
29655 volume format supported by the system.
29657 @defvar {Scheme Variable} pam-mount-service-type
29658 Service type for PAM Mount support.
29661 @deftp {Data Type} pam-mount-configuration
29662 Data type representing the configuration of PAM Mount.
29664 It takes the following parameters:
29668 The configuration rules that will be used to generate
29669 @file{/etc/security/pam_mount.conf.xml}.
29671 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
29672 Guile Reference Manual}), and the default ones don't mount anything for
29676 `((debug (@@ (enable "0")))
29677 (mntoptions (@@ (allow ,(string-join
29678 '("nosuid" "nodev" "loop"
29679 "encryption" "fsck" "nonempty"
29680 "allow_root" "allow_other")
29682 (mntoptions (@@ (require "nosuid,nodev")))
29683 (logout (@@ (wait "0")
29687 (mkmountpoint (@@ (enable "1")
29691 Some @code{volume} elements must be added to automatically mount volumes
29692 at login. Here's an example allowing the user @code{alice} to mount her
29693 encrypted @env{HOME} directory and allowing the user @code{bob} to mount
29694 the partition where he stores his data:
29697 (define pam-mount-rules
29698 `((debug (@@ (enable "0")))
29699 (volume (@@ (user "alice")
29702 (mountpoint "/home/alice")))
29703 (volume (@@ (user "bob")
29706 (mountpoint "/home/bob/data")
29707 (options "defaults,autodefrag,compress")))
29708 (mntoptions (@@ (allow ,(string-join
29709 '("nosuid" "nodev" "loop"
29710 "encryption" "fsck" "nonempty"
29711 "allow_root" "allow_other")
29713 (mntoptions (@@ (require "nosuid,nodev")))
29714 (logout (@@ (wait "0")
29718 (mkmountpoint (@@ (enable "1")
29719 (remove "true")))))
29721 (service pam-mount-service-type
29722 (pam-mount-configuration
29723 (rules pam-mount-rules)))
29726 The complete list of possible options can be found in the man page for
29727 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
29732 @node Guix Services
29733 @subsection Guix Services
29735 @subsubheading Guix Build Coordinator
29736 The @uref{https://git.cbaines.net/guix/build-coordinator/,Guix Build
29737 Coordinator} aids in distributing derivation builds among machines
29738 running an @dfn{agent}. The build daemon is still used to build the
29739 derivations, but the Guix Build Coordinator manages allocating builds
29740 and working with the results.
29743 This service is considered experimental. Configuration options may be
29744 changed in a backwards-incompatible manner, and not all features have
29745 been thorougly tested.
29748 The Guix Build Coordinator consists of one @dfn{coordinator}, and one or
29749 more connected @dfn{agent} processes. The coordinator process handles
29750 clients submitting builds, and allocating builds to agents. The agent
29751 processes talk to a build daemon to actually perform the builds, then
29752 send the results back to the coordinator.
29754 There is a script to run the coordinator component of the Guix Build
29755 Coordinator, but the Guix service uses a custom Guile script instead, to
29756 provide better integration with G-expressions used in the configuration.
29758 @defvar {Scheme Variable} guix-build-coordinator-service-type
29759 Service type for the Guix Build Coordinator. Its value must be a
29760 @code{guix-build-coordinator-configuration} object.
29763 @deftp {Data Type} guix-build-coordinator-configuration
29764 Data type representing the configuration of the Guix Build Coordinator.
29767 @item @code{package} (default: @code{guix-build-coordinator})
29768 The Guix Build Coordinator package to use.
29770 @item @code{user} (default: @code{"guix-build-coordinator"})
29771 The system user to run the service as.
29773 @item @code{group} (default: @code{"guix-build-coordinator"})
29774 The system group to run the service as.
29776 @item @code{database-uri-string} (default: @code{"sqlite:///var/lib/guix-build-coordinator/guix_build_coordinator.db"})
29777 The URI to use for the database.
29779 @item @code{agent-communication-uri} (default: @code{"http://0.0.0.0:8745"})
29780 The URI describing how to listen to requests from agent processes.
29782 @item @code{client-communication-uri} (default: @code{"http://127.0.0.1:8746"})
29783 The URI describing how to listen to requests from clients. The client
29784 API allows submitting builds and currently isn't authenticated, so take
29785 care when configuring this value.
29787 @item @code{allocation-strategy} (default: @code{#~basic-build-allocation-strategy})
29788 A G-expression for the allocation strategy to be used. This is a
29789 procedure that takes the datastore as an argument and populates the
29790 allocation plan in the database.
29792 @item @code{hooks} (default: @var{'()})
29793 An association list of hooks. These provide a way to execute arbitrary
29794 code upon certain events, like a build result being processed.
29796 @item @code{guile} (default: @code{guile-3.0-latest})
29797 The Guile package with which to run the Guix Build Coordinator.
29802 @defvar {Scheme Variable} guix-build-coordinator-agent-service-type
29803 Service type for a Guix Build Coordinator agent. Its value must be a
29804 @code{guix-build-coordinator-agent-configuration} object.
29807 @deftp {Data Type} guix-build-coordinator-agent-configuration
29808 Data type representing the configuration a Guix Build Coordinator agent.
29811 @item @code{package} (default: @code{guix-build-coordinator})
29812 The Guix Build Coordinator package to use.
29814 @item @code{user} (default: @code{"guix-build-coordinator-agent"})
29815 The system user to run the service as.
29817 @item @code{coordinator} (default: @code{"http://localhost:8745"})
29818 The URI to use when connecting to the coordinator.
29821 The UUID of the agent. This should be generated by the coordinator
29822 process, stored in the coordinator database, and used by the intended
29825 @item @code{password} (default: @code{#f})
29826 The password to use when connecting to the coordinator. A file to read
29827 the password from can also be specified, and this is more secure.
29829 @item @code{password-file} (default: @code{#f})
29830 A file containing the password to use when connecting to the
29833 @item @code{systems} (default: @code{#f})
29834 The systems for which this agent should fetch builds. The agent process
29835 will use the current system it's running on as the default.
29837 @item @code{max-parallel-builds} (default: @code{1})
29838 The number of builds to perform in parallel.
29840 @item @code{derivation-substitute-urls} (default: @code{#f})
29841 URLs from which to attempt to fetch substitutes for derivations, if the
29842 derivations aren't already available.
29844 @item @code{non-derivation-substitute-urls} (default: @code{#f})
29845 URLs from which to attempt to fetch substitutes for build inputs, if the
29846 input store items aren't already available.
29851 The Guix Build Coordinator package contains a script to query an
29852 instance of the Guix Data Service for derivations to build, and then
29853 submit builds for those derivations to the coordinator. The service
29854 type below assists in running this script. This is an additional tool
29855 that may be useful when building derivations contained within an
29856 instance of the Guix Data Service.
29858 @defvar {Scheme Variable} guix-build-coordinator-queue-builds-service-type
29859 Service type for the
29860 guix-build-coordinator-queue-builds-from-guix-data-service script. Its
29861 value must be a @code{guix-build-coordinator-queue-builds-configuration}
29865 @deftp {Data Type} guix-build-coordinator-queue-builds-configuration
29866 Data type representing the options to the queue builds from guix data
29870 @item @code{package} (default: @code{guix-build-coordinator})
29871 The Guix Build Coordinator package to use.
29873 @item @code{user} (default: @code{"guix-build-coordinator-queue-builds"})
29874 The system user to run the service as.
29876 @item @code{coordinator} (default: @code{"http://localhost:8745"})
29877 The URI to use when connecting to the coordinator.
29879 @item @code{systems} (default: @code{#f})
29880 The systems for which to fetch derivations to build.
29882 @item @code{systems-and-targets} (default: @code{#f})
29883 An association list of system and target pairs for which to fetch
29884 derivations to build.
29886 @item @code{guix-data-service} (default: @code{"https://data.guix.gnu.org"})
29887 The Guix Data Service instance from which to query to find out about
29888 derivations to build.
29890 @item @code{processed-commits-file} (default: @code{"/var/cache/guix-build-coordinator-queue-builds/processed-commits"})
29891 A file to record which commits have been processed, to avoid needlessly
29892 processing them again if the service is restarted.
29897 @subsubheading Guix Data Service
29898 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
29899 and provides data about GNU Guix. This includes information about
29900 packages, derivations and lint warnings.
29902 The data is stored in a PostgreSQL database, and available through a web
29905 @defvar {Scheme Variable} guix-data-service-type
29906 Service type for the Guix Data Service. Its value must be a
29907 @code{guix-data-service-configuration} object. The service optionally
29908 extends the getmail service, as the guix-commits mailing list is used to
29909 find out about changes in the Guix git repository.
29912 @deftp {Data Type} guix-data-service-configuration
29913 Data type representing the configuration of the Guix Data Service.
29916 @item @code{package} (default: @code{guix-data-service})
29917 The Guix Data Service package to use.
29919 @item @code{user} (default: @code{"guix-data-service"})
29920 The system user to run the service as.
29922 @item @code{group} (default: @code{"guix-data-service"})
29923 The system group to run the service as.
29925 @item @code{port} (default: @code{8765})
29926 The port to bind the web service to.
29928 @item @code{host} (default: @code{"127.0.0.1"})
29929 The host to bind the web service to.
29931 @item @code{getmail-idle-mailboxes} (default: @code{#f})
29932 If set, this is the list of mailboxes that the getmail service will be
29933 configured to listen to.
29935 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
29936 If set, this is the @code{getmail-retriever-configuration} object with
29937 which to configure getmail to fetch mail from the guix-commits mailing
29940 @item @code{extra-options} (default: @var{'()})
29941 Extra command line options for @code{guix-data-service}.
29943 @item @code{extra-process-jobs-options} (default: @var{'()})
29944 Extra command line options for @code{guix-data-service-process-jobs}.
29949 @node Linux Services
29950 @subsection Linux Services
29953 @cindex out of memory killer
29955 @cindex early out of memory daemon
29956 @subsubheading Early OOM Service
29958 @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
29959 Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
29960 space and provides a more responsive and configurable alternative to the
29961 in-kernel OOM killer. It is useful to prevent the system from becoming
29962 unresponsive when it runs out of memory.
29964 @deffn {Scheme Variable} earlyoom-service-type
29965 The service type for running @command{earlyoom}, the Early OOM daemon.
29966 Its value must be a @code{earlyoom-configuration} object, described
29967 below. The service can be instantiated in its default configuration
29971 (service earlyoom-service-type)
29975 @deftp {Data Type} earlyoom-configuration
29976 This is the configuration record for the @code{earlyoom-service-type}.
29979 @item @code{earlyoom} (default: @var{earlyoom})
29980 The Earlyoom package to use.
29982 @item @code{minimum-available-memory} (default: @code{10})
29983 The threshold for the minimum @emph{available} memory, in percentages.
29985 @item @code{minimum-free-swap} (default: @code{10})
29986 The threshold for the minimum free swap memory, in percentages.
29988 @item @code{prefer-regexp} (default: @code{#f})
29989 A regular expression (as a string) to match the names of the processes
29990 that should be preferably killed.
29992 @item @code{avoid-regexp} (default: @code{#f})
29993 A regular expression (as a string) to match the names of the processes
29994 that should @emph{not} be killed.
29996 @item @code{memory-report-interval} (default: @code{0})
29997 The interval in seconds at which a memory report is printed. It is
29998 disabled by default.
30000 @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
30001 A boolean indicating whether the positive adjustments set in
30002 @file{/proc/*/oom_score_adj} should be ignored.
30004 @item @code{show-debug-messages?} (default: @code{#f})
30005 A boolean indicating whether debug messages should be printed. The logs
30006 are saved at @file{/var/log/earlyoom.log}.
30008 @item @code{send-notification-command} (default: @code{#f})
30009 This can be used to provide a custom command used for sending
30015 @cindex kernel module loader
30016 @subsubheading Kernel Module Loader Service
30018 The kernel module loader service allows one to load loadable kernel
30019 modules at boot. This is especially useful for modules that don't
30020 autoload and need to be manually loaded, as it's the case with
30023 @deffn {Scheme Variable} kernel-module-loader-service-type
30024 The service type for loading loadable kernel modules at boot with
30025 @command{modprobe}. Its value must be a list of strings representing
30026 module names. For example loading the drivers provided by
30027 @code{ddcci-driver-linux}, in debugging mode by passing some module
30028 parameters, can be done as follow:
30031 (use-modules (gnu) (gnu services))
30032 (use-package-modules linux)
30033 (use-service-modules linux)
30035 (define ddcci-config
30036 (plain-file "ddcci.conf"
30037 "options ddcci dyndbg delay=120"))
30041 (services (cons* (service kernel-module-loader-service-type
30042 '("ddcci" "ddcci_backlight"))
30043 (simple-service 'ddcci-config etc-service-type
30044 (list `("modprobe.d/ddcci.conf"
30047 (kernel-loadable-modules (list ddcci-driver-linux)))
30052 @cindex compressed swap
30053 @cindex Compressed RAM-based block devices
30054 @subsubheading Zram Device Service
30056 The Zram device service provides a compressed swap device in system
30057 memory. The Linux Kernel documentation has more information about
30058 @uref{https://www.kernel.org/doc/html/latest/admin-guide/blockdev/zram.html,zram}
30061 @deffn {Scheme Variable} zram-device-service-type
30062 This service creates the zram block device, formats it as swap and
30063 enables it as a swap device. The service's value is a
30064 @code{zram-device-configuration} record.
30066 @deftp {Data Type} zram-device-configuration
30067 This is the data type representing the configuration for the zram-device
30071 @item @code{size} (default @code{"1G"})
30072 This is the amount of space you wish to provide for the zram device. It
30073 accepts a string and can be a number of bytes or use a suffix, eg.:
30074 @code{"512M"} or @code{1024000}.
30075 @item @code{compression-algorithm} (default @code{'lzo})
30076 This is the compression algorithm you wish to use. It is difficult to
30077 list all the possible compression options, but common ones supported by
30078 Guix's Linux Libre Kernel include @code{'lzo}, @code{'lz4} and @code{'zstd}.
30079 @item @code{memory-limit} (default @code{0})
30080 This is the maximum amount of memory which the zram device can use.
30081 Setting it to '0' disables the limit. While it is generally expected
30082 that compression will be 2:1, it is possible that uncompressable data
30083 can be written to swap and this is a method to limit how much memory can
30084 be used. It accepts a string and can be a number of bytes or use a
30085 suffix, eg.: @code{"2G"}.
30086 @item @code{priority} (default @code{-1})
30087 This is the priority of the swap device created from the zram device.
30088 @code{swapon} accepts values between -1 and 32767, with higher values
30089 indicating higher priority. Higher priority swap will generally be used
30096 @node Hurd Services
30097 @subsection Hurd Services
30099 @defvr {Scheme Variable} hurd-console-service-type
30100 This service starts the fancy @code{VGA} console client on the Hurd.
30102 The service's value is a @code{hurd-console-configuration} record.
30105 @deftp {Data Type} hurd-console-configuration
30106 This is the data type representing the configuration for the
30107 hurd-console-service.
30110 @item @code{hurd} (default: @var{hurd})
30111 The Hurd package to use.
30115 @defvr {Scheme Variable} hurd-getty-service-type
30116 This service starts a tty using the Hurd @code{getty} program.
30118 The service's value is a @code{hurd-getty-configuration} record.
30121 @deftp {Data Type} hurd-getty-configuration
30122 This is the data type representing the configuration for the
30123 hurd-getty-service.
30126 @item @code{hurd} (default: @var{hurd})
30127 The Hurd package to use.
30130 The name of the console this Getty runs on---e.g., @code{"tty1"}.
30132 @item @code{baud-rate} (default: @code{38400})
30133 An integer specifying the baud rate of the tty.
30138 @node Miscellaneous Services
30139 @subsection Miscellaneous Services
30141 @cindex fingerprint
30142 @subsubheading Fingerprint Service
30144 The @code{(gnu services authentication)} module provides a DBus service to
30145 read and identify fingerprints via a fingerprint sensor.
30147 @defvr {Scheme Variable} fprintd-service-type
30148 The service type for @command{fprintd}, which provides the fingerprint
30149 reading capability.
30152 (service fprintd-service-type)
30157 @subsubheading System Control Service
30159 The @code{(gnu services sysctl)} provides a service to configure kernel
30160 parameters at boot.
30162 @defvr {Scheme Variable} sysctl-service-type
30163 The service type for @command{sysctl}, which modifies kernel parameters
30164 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
30168 (service sysctl-service-type
30169 (sysctl-configuration
30170 (settings '(("net.ipv4.ip_forward" . "1")))))
30174 @deftp {Data Type} sysctl-configuration
30175 The data type representing the configuration of @command{sysctl}.
30178 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
30179 The @command{sysctl} executable to use.
30181 @item @code{settings} (default: @code{'()})
30182 An association list specifies kernel parameters and their values.
30187 @subsubheading PC/SC Smart Card Daemon Service
30189 The @code{(gnu services security-token)} module provides the following service
30190 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
30191 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
30192 manager that coordinates communications with smart card readers, smart cards
30193 and cryptographic tokens that are connected to the system.
30195 @defvr {Scheme Variable} pcscd-service-type
30196 Service type for the @command{pcscd} service. Its value must be a
30197 @code{pcscd-configuration} object. To run pcscd in the default
30198 configuration, instantiate it as:
30201 (service pcscd-service-type)
30205 @deftp {Data Type} pcscd-configuration
30206 The data type representing the configuration of @command{pcscd}.
30209 @item @code{pcsc-lite} (default: @code{pcsc-lite})
30210 The pcsc-lite package that provides pcscd.
30211 @item @code{usb-drivers} (default: @code{(list ccid)})
30212 List of packages that provide USB drivers to pcscd. Drivers are expected to be
30213 under @file{pcsc/drivers} in the store directory of the package.
30218 @subsubheading Lirc Service
30220 The @code{(gnu services lirc)} module provides the following service.
30222 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
30223 [#:device #f] [#:driver #f] [#:config-file #f] @
30224 [#:extra-options '()]
30225 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
30226 decodes infrared signals from remote controls.
30228 Optionally, @var{device}, @var{driver} and @var{config-file}
30229 (configuration file name) may be specified. See @command{lircd} manual
30232 Finally, @var{extra-options} is a list of additional command-line options
30233 passed to @command{lircd}.
30237 @subsubheading Spice Service
30239 The @code{(gnu services spice)} module provides the following service.
30241 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
30242 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
30243 that enables sharing the clipboard with a vm and setting the guest display
30244 resolution when the graphical console window resizes.
30247 @cindex inputattach
30248 @subsubheading inputattach Service
30250 @cindex tablet input, for Xorg
30251 @cindex touchscreen input, for Xorg
30252 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
30253 use input devices such as Wacom tablets, touchscreens, or joysticks with the
30254 Xorg display server.
30256 @deffn {Scheme Variable} inputattach-service-type
30257 Type of a service that runs @command{inputattach} on a device and
30258 dispatches events from it.
30261 @deftp {Data Type} inputattach-configuration
30263 @item @code{device-type} (default: @code{"wacom"})
30264 The type of device to connect to. Run @command{inputattach --help}, from the
30265 @code{inputattach} package, to see the list of supported device types.
30267 @item @code{device} (default: @code{"/dev/ttyS0"})
30268 The device file to connect to the device.
30270 @item @code{baud-rate} (default: @code{#f})
30271 Baud rate to use for the serial connection.
30272 Should be a number or @code{#f}.
30274 @item @code{log-file} (default: @code{#f})
30275 If true, this must be the name of a file to log messages to.
30279 @subsubheading Dictionary Service
30281 The @code{(gnu services dict)} module provides the following service:
30283 @defvr {Scheme Variable} dicod-service-type
30284 This is the type of the service that runs the @command{dicod} daemon, an
30285 implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
30288 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
30289 Return a service that runs the @command{dicod} daemon, an implementation
30290 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
30292 The optional @var{config} argument specifies the configuration for
30293 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
30294 default it serves the GNU Collaborative International Dictionary of English.
30296 You can add @command{open localhost} to your @file{~/.dico} file to make
30297 @code{localhost} the default server for @command{dico} client
30298 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
30301 @deftp {Data Type} dicod-configuration
30302 Data type representing the configuration of dicod.
30305 @item @code{dico} (default: @var{dico})
30306 Package object of the GNU Dico dictionary server.
30308 @item @code{interfaces} (default: @var{'("localhost")})
30309 This is the list of IP addresses and ports and possibly socket file
30310 names to listen to (@pxref{Server Settings, @code{listen} directive,,
30311 dico, GNU Dico Manual}).
30313 @item @code{handlers} (default: @var{'()})
30314 List of @code{<dicod-handler>} objects denoting handlers (module instances).
30316 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
30317 List of @code{<dicod-database>} objects denoting dictionaries to be served.
30321 @deftp {Data Type} dicod-handler
30322 Data type representing a dictionary handler (module instance).
30326 Name of the handler (module instance).
30328 @item @code{module} (default: @var{#f})
30329 Name of the dicod module of the handler (instance). If it is @code{#f},
30330 the module has the same name as the handler.
30331 (@pxref{Modules,,, dico, GNU Dico Manual}).
30333 @item @code{options}
30334 List of strings or gexps representing the arguments for the module handler
30338 @deftp {Data Type} dicod-database
30339 Data type representing a dictionary database.
30343 Name of the database, will be used in DICT commands.
30345 @item @code{handler}
30346 Name of the dicod handler (module instance) used by this database
30347 (@pxref{Handlers,,, dico, GNU Dico Manual}).
30349 @item @code{complex?} (default: @var{#f})
30350 Whether the database configuration complex. The complex configuration
30351 will need a corresponding @code{<dicod-handler>} object, otherwise not.
30353 @item @code{options}
30354 List of strings or gexps representing the arguments for the database
30355 (@pxref{Databases,,, dico, GNU Dico Manual}).
30359 @defvr {Scheme Variable} %dicod-database:gcide
30360 A @code{<dicod-database>} object serving the GNU Collaborative International
30361 Dictionary of English using the @code{gcide} package.
30364 The following is an example @code{dicod-service} configuration.
30367 (dicod-service #:config
30368 (dicod-configuration
30369 (handlers (list (dicod-handler
30373 (list #~(string-append "dbdir=" #$wordnet))))))
30374 (databases (list (dicod-database
30377 (handler "wordnet")
30378 (options '("database=wn")))
30379 %dicod-database:gcide))))
30383 @subsubheading Docker Service
30385 The @code{(gnu services docker)} module provides the following services.
30387 @defvr {Scheme Variable} docker-service-type
30389 This is the type of the service that runs @url{https://www.docker.com,Docker},
30390 a daemon that can execute application bundles (sometimes referred to as
30391 ``containers'') in isolated environments.
30395 @deftp {Data Type} docker-configuration
30396 This is the data type representing the configuration of Docker and Containerd.
30400 @item @code{package} (default: @code{docker})
30401 The Docker daemon package to use.
30403 @item @code{package} (default: @code{docker-cli})
30404 The Docker client package to use.
30406 @item @code{containerd} (default: @var{containerd})
30407 The Containerd package to use.
30409 @item @code{proxy} (default @var{docker-libnetwork-cmd-proxy})
30410 The Docker user-land networking proxy package to use.
30412 @item @code{enable-proxy?} (default @code{#t})
30413 Enable or disable the use of the Docker user-land networking proxy.
30415 @item @code{debug?} (default @code{#f})
30416 Enable or disable debug output.
30418 @item @code{enable-iptables?} (default @code{#t})
30419 Enable or disable the addition of iptables rules.
30424 @cindex Singularity, container service
30425 @defvr {Scheme Variable} singularity-service-type
30426 This is the type of the service that allows you to run
30427 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
30428 create and run application bundles (aka. ``containers''). The value for this
30429 service is the Singularity package to use.
30431 The service does not install a daemon; instead, it installs helper programs as
30432 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
30433 @command{singularity run} and similar commands.
30437 @subsubheading Auditd Service
30439 The @code{(gnu services auditd)} module provides the following service.
30441 @defvr {Scheme Variable} auditd-service-type
30443 This is the type of the service that runs
30444 @url{https://people.redhat.com/sgrubb/audit/,auditd},
30445 a daemon that tracks security-relevant information on your system.
30447 Examples of things that can be tracked:
30457 Failed login attempts
30464 @command{auditctl} from the @code{audit} package can be used in order
30465 to add or remove events to be tracked (until the next reboot).
30466 In order to permanently track events, put the command line arguments
30467 of auditctl into a file called @code{audit.rules} in the configuration
30468 directory (see below).
30469 @command{aureport} from the @code{audit} package can be used in order
30470 to view a report of all recorded events.
30471 The audit daemon by default logs into the file
30472 @file{/var/log/audit.log}.
30476 @deftp {Data Type} auditd-configuration
30477 This is the data type representing the configuration of auditd.
30481 @item @code{audit} (default: @code{audit})
30482 The audit package to use.
30484 @item @code{configuration-directory} (default: @code{%default-auditd-configuration-directory})
30485 The directory containing the configuration file for the audit package, which
30486 must be named @code{auditd.conf}, and optionally some audit rules to
30487 instantiate on startup.
30493 @subsubheading R-Shiny service
30495 The @code{(gnu services science)} module provides the following service.
30497 @defvr {Scheme Variable} rshiny-service-type
30499 This is a type of service which is used to run a webapp created with
30500 @code{r-shiny}. This service sets the @env{R_LIBS_USER} environment
30501 variable and runs the provided script to call @code{runApp}.
30503 @deftp {Data Type} rshiny-configuration
30504 This is the data type representing the configuration of rshiny.
30508 @item @code{package} (default: @code{r-shiny})
30509 The package to use.
30511 @item @code{binary} (defaunlt @code{"rshiny"})
30512 The name of the binary or shell script located at @code{package/bin/} to
30513 run when the service is run.
30515 The common way to create this file is as follows:
30519 (let* ((out (assoc-ref %outputs "out"))
30520 (targetdir (string-append out "/share/" ,name))
30521 (app (string-append out "/bin/" ,name))
30522 (Rbin (string-append (assoc-ref %build-inputs "r-min")
30525 (mkdir-p (string-append out "/bin"))
30526 (call-with-output-file app
30532 runApp(launch.browser=0, port=4202)~%\n"
30541 @subsubheading Nix service
30543 The @code{(gnu services nix)} module provides the following service.
30545 @defvr {Scheme Variable} nix-service-type
30547 This is the type of the service that runs build daemon of the
30548 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
30552 (use-modules (gnu))
30553 (use-service-modules nix)
30554 (use-package-modules package-management)
30558 (packages (append (list nix)
30561 (services (append (list (service nix-service-type))
30565 After @command{guix system reconfigure} configure Nix for your user:
30568 @item Add a Nix channel and update it. See
30569 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
30571 @item Create a symlink to your profile and activate Nix profile:
30575 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
30576 $ source /run/current-system/profile/etc/profile.d/nix.sh
30581 @deftp {Data Type} nix-configuration
30582 This data type represents the configuration of the Nix daemon.
30585 @item @code{nix} (default: @code{nix})
30586 The Nix package to use.
30588 @item @code{sandbox} (default: @code{#t})
30589 Specifies whether builds are sandboxed by default.
30591 @item @code{build-sandbox-items} (default: @code{'()})
30592 This is a list of strings or objects appended to the
30593 @code{build-sandbox-items} field of the configuration file.
30595 @item @code{extra-config} (default: @code{'()})
30596 This is a list of strings or objects appended to the configuration file.
30597 It is used to pass extra text to be added verbatim to the configuration
30600 @item @code{extra-options} (default: @code{'()})
30601 Extra command line options for @code{nix-service-type}.
30605 @node Setuid Programs
30606 @section Setuid Programs
30608 @cindex setuid programs
30609 Some programs need to run with ``root'' privileges, even when they are
30610 launched by unprivileged users. A notorious example is the
30611 @command{passwd} program, which users can run to change their
30612 password, and which needs to access the @file{/etc/passwd} and
30613 @file{/etc/shadow} files---something normally restricted to root, for
30614 obvious security reasons. To address that, these executables are
30615 @dfn{setuid-root}, meaning that they always run with root privileges
30616 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
30617 for more info about the setuid mechanism).
30619 The store itself @emph{cannot} contain setuid programs: that would be a
30620 security issue since any user on the system can write derivations that
30621 populate the store (@pxref{The Store}). Thus, a different mechanism is
30622 used: instead of changing the setuid bit directly on files that are in
30623 the store, we let the system administrator @emph{declare} which programs
30624 should be setuid root.
30626 The @code{setuid-programs} field of an @code{operating-system}
30627 declaration contains a list of G-expressions denoting the names of
30628 programs to be setuid-root (@pxref{Using the Configuration System}).
30629 For instance, the @command{passwd} program, which is part of the Shadow
30630 package, can be designated by this G-expression (@pxref{G-Expressions}):
30633 #~(string-append #$shadow "/bin/passwd")
30636 A default set of setuid programs is defined by the
30637 @code{%setuid-programs} variable of the @code{(gnu system)} module.
30639 @defvr {Scheme Variable} %setuid-programs
30640 A list of G-expressions denoting common programs that are setuid-root.
30642 The list includes commands such as @command{passwd}, @command{ping},
30643 @command{su}, and @command{sudo}.
30646 Under the hood, the actual setuid programs are created in the
30647 @file{/run/setuid-programs} directory at system activation time. The
30648 files in this directory refer to the ``real'' binaries, which are in the
30651 @node X.509 Certificates
30652 @section X.509 Certificates
30654 @cindex HTTPS, certificates
30655 @cindex X.509 certificates
30657 Web servers available over HTTPS (that is, HTTP over the transport-layer
30658 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
30659 that the client can then use to @emph{authenticate} the server. To do
30660 that, clients verify that the server's certificate is signed by a
30661 so-called @dfn{certificate authority} (CA). But to verify the CA's
30662 signature, clients must have first acquired the CA's certificate.
30664 Web browsers such as GNU@tie{}IceCat include their own set of CA
30665 certificates, such that they are able to verify CA signatures
30668 However, most other programs that can talk HTTPS---@command{wget},
30669 @command{git}, @command{w3m}, etc.---need to be told where CA
30670 certificates can be found.
30672 @cindex @code{nss-certs}
30673 In Guix, this is done by adding a package that provides certificates
30674 to the @code{packages} field of the @code{operating-system} declaration
30675 (@pxref{operating-system Reference}). Guix includes one such package,
30676 @code{nss-certs}, which is a set of CA certificates provided as part of
30677 Mozilla's Network Security Services.
30679 Note that it is @emph{not} part of @code{%base-packages}, so you need to
30680 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
30681 most applications and libraries look for certificates by default, points
30682 to the certificates installed globally.
30684 Unprivileged users, including users of Guix on a foreign distro,
30685 can also install their own certificate package in
30686 their profile. A number of environment variables need to be defined so
30687 that applications and libraries know where to find them. Namely, the
30688 OpenSSL library honors the @env{SSL_CERT_DIR} and @env{SSL_CERT_FILE}
30689 variables. Some applications add their own environment variables; for
30690 instance, the Git version control system honors the certificate bundle
30691 pointed to by the @env{GIT_SSL_CAINFO} environment variable. Thus, you
30692 would typically run something like:
30695 guix install nss-certs
30696 export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
30697 export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
30698 export GIT_SSL_CAINFO="$SSL_CERT_FILE"
30701 As another example, R requires the @env{CURL_CA_BUNDLE} environment
30702 variable to point to a certificate bundle, so you would have to run
30703 something like this:
30706 guix install nss-certs
30707 export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
30710 For other applications you may want to look up the required environment
30711 variable in the relevant documentation.
30714 @node Name Service Switch
30715 @section Name Service Switch
30717 @cindex name service switch
30719 The @code{(gnu system nss)} module provides bindings to the
30720 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
30721 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
30722 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
30723 extended with new ``name'' lookup methods for system databases, which
30724 includes host names, service names, user accounts, and more (@pxref{Name
30725 Service Switch, System Databases and Name Service Switch,, libc, The GNU
30726 C Library Reference Manual}).
30728 The NSS configuration specifies, for each system database, which lookup
30729 method is to be used, and how the various methods are chained
30730 together---for instance, under which circumstances NSS should try the
30731 next method in the list. The NSS configuration is given in the
30732 @code{name-service-switch} field of @code{operating-system} declarations
30733 (@pxref{operating-system Reference, @code{name-service-switch}}).
30736 @cindex .local, host name lookup
30737 As an example, the declaration below configures the NSS to use the
30738 @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
30739 back-end}, which supports host name lookups over multicast DNS (mDNS)
30740 for host names ending in @code{.local}:
30743 (name-service-switch
30744 (hosts (list %files ;first, check /etc/hosts
30746 ;; If the above did not succeed, try
30747 ;; with 'mdns_minimal'.
30749 (name "mdns_minimal")
30751 ;; 'mdns_minimal' is authoritative for
30752 ;; '.local'. When it returns "not found",
30753 ;; no need to try the next methods.
30754 (reaction (lookup-specification
30755 (not-found => return))))
30757 ;; Then fall back to DNS.
30761 ;; Finally, try with the "full" 'mdns'.
30766 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
30767 contains this configuration, so you will not have to type it if all you
30768 want is to have @code{.local} host lookup working.
30770 Note that, in this case, in addition to setting the
30771 @code{name-service-switch} of the @code{operating-system} declaration,
30772 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
30773 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
30774 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
30775 to the name service cache daemon (@pxref{Base Services,
30776 @code{nscd-service}}).
30778 For convenience, the following variables provide typical NSS
30781 @defvr {Scheme Variable} %default-nss
30782 This is the default name service switch configuration, a
30783 @code{name-service-switch} object.
30786 @defvr {Scheme Variable} %mdns-host-lookup-nss
30787 This is the name service switch configuration with support for host name
30788 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
30791 The reference for name service switch configuration is given below. It
30792 is a direct mapping of the configuration file format of the C library , so
30793 please refer to the C library manual for more information (@pxref{NSS
30794 Configuration File,,, libc, The GNU C Library Reference Manual}).
30795 Compared to the configuration file format of libc NSS, it has the advantage
30796 not only of adding this warm parenthetic feel that we like, but also
30797 static checks: you will know about syntax errors and typos as soon as you
30798 run @command{guix system}.
30800 @deftp {Data Type} name-service-switch
30802 This is the data type representation the configuration of libc's name
30803 service switch (NSS). Each field below represents one of the supported
30820 The system databases handled by the NSS@. Each of these fields must be a
30821 list of @code{<name-service>} objects (see below).
30825 @deftp {Data Type} name-service
30827 This is the data type representing an actual name service and the
30828 associated lookup action.
30832 A string denoting the name service (@pxref{Services in the NSS
30833 configuration,,, libc, The GNU C Library Reference Manual}).
30835 Note that name services listed here must be visible to nscd. This is
30836 achieved by passing the @code{#:name-services} argument to
30837 @code{nscd-service} the list of packages providing the needed name
30838 services (@pxref{Base Services, @code{nscd-service}}).
30841 An action specified using the @code{lookup-specification} macro
30842 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
30843 Reference Manual}). For example:
30846 (lookup-specification (unavailable => continue)
30847 (success => return))
30852 @node Initial RAM Disk
30853 @section Initial RAM Disk
30856 @cindex initial RAM disk
30857 For bootstrapping purposes, the Linux-Libre kernel is passed an
30858 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
30859 root file system as well as an initialization script. The latter is
30860 responsible for mounting the real root file system, and for loading any
30861 kernel modules that may be needed to achieve that.
30863 The @code{initrd-modules} field of an @code{operating-system}
30864 declaration allows you to specify Linux-libre kernel modules that must
30865 be available in the initrd. In particular, this is where you would list
30866 modules needed to actually drive the hard disk where your root partition
30867 is---although the default value of @code{initrd-modules} should cover
30868 most use cases. For example, assuming you need the @code{megaraid_sas}
30869 module in addition to the default modules to be able to access your root
30870 file system, you would write:
30875 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
30878 @defvr {Scheme Variable} %base-initrd-modules
30879 This is the list of kernel modules included in the initrd by default.
30882 Furthermore, if you need lower-level customization, the @code{initrd}
30883 field of an @code{operating-system} declaration allows
30884 you to specify which initrd you would like to use. The @code{(gnu
30885 system linux-initrd)} module provides three ways to build an initrd: the
30886 high-level @code{base-initrd} procedure and the low-level
30887 @code{raw-initrd} and @code{expression->initrd} procedures.
30889 The @code{base-initrd} procedure is intended to cover most common uses.
30890 For example, if you want to add a bunch of kernel modules to be loaded
30891 at boot time, you can define the @code{initrd} field of the operating
30892 system declaration like this:
30895 (initrd (lambda (file-systems . rest)
30896 ;; Create a standard initrd but set up networking
30897 ;; with the parameters QEMU expects by default.
30898 (apply base-initrd file-systems
30899 #:qemu-networking? #t
30903 The @code{base-initrd} procedure also handles common use cases that
30904 involves using the system as a QEMU guest, or as a ``live'' system with
30905 volatile root file system.
30907 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
30908 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
30909 such as trying to guess which kernel modules and packages should be included
30910 to the initrd. An example use of @code{raw-initrd} is when a user has
30911 a custom Linux kernel configuration and default kernel modules included by
30912 @code{base-initrd} are not available.
30914 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
30915 honors several options passed on the Linux kernel command line
30916 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
30917 @code{-append} option of QEMU), notably:
30920 @item --load=@var{boot}
30921 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
30922 program, once it has mounted the root file system.
30924 Guix uses this option to yield control to a boot program that runs the
30925 service activation programs and then spawns the GNU@tie{}Shepherd, the
30926 initialization system.
30928 @item --root=@var{root}
30929 Mount @var{root} as the root file system. @var{root} can be a device
30930 name like @code{/dev/sda1}, a file system label, or a file system UUID.
30931 When unspecified, the device name from the root file system of the
30932 operating system declaration is used.
30934 @item --system=@var{system}
30935 Have @file{/run/booted-system} and @file{/run/current-system} point to
30938 @item modprobe.blacklist=@var{modules}@dots{}
30939 @cindex module, black-listing
30940 @cindex black list, of kernel modules
30941 Instruct the initial RAM disk as well as the @command{modprobe} command
30942 (from the kmod package) to refuse to load @var{modules}. @var{modules}
30943 must be a comma-separated list of module names---e.g.,
30944 @code{usbkbd,9pnet}.
30947 Start a read-eval-print loop (REPL) from the initial RAM disk before it
30948 tries to load kernel modules and to mount the root file system. Our
30949 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
30950 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
30951 Manual}, for more information on Guile's REPL.
30955 Now that you know all the features that initial RAM disks produced by
30956 @code{base-initrd} and @code{raw-initrd} provide,
30957 here is how to use it and customize it further.
30960 @cindex initial RAM disk
30961 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
30962 [#:linux-modules '()] [#:mapped-devices '()] @
30963 [#:keyboard-layout #f] @
30964 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
30965 Return a derivation that builds a raw initrd. @var{file-systems} is
30966 a list of file systems to be mounted by the initrd, possibly in addition to
30967 the root file system specified on the kernel command line via @option{--root}.
30968 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
30969 @var{mapped-devices} is a list of device mappings to realize before
30970 @var{file-systems} are mounted (@pxref{Mapped Devices}).
30971 @var{helper-packages} is a list of packages to be copied in the initrd.
30973 include @code{e2fsck/static} or other packages needed by the initrd to check
30974 the root file system.
30976 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
30977 the desired console keyboard layout. This is done before @var{mapped-devices}
30978 are set up and before @var{file-systems} are mounted such that, should the
30979 user need to enter a passphrase or use the REPL, this happens using the
30980 intended keyboard layout.
30982 When @var{qemu-networking?} is true, set up networking with the standard QEMU
30983 parameters. When @var{virtio?} is true, load additional modules so that the
30984 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
30986 When @var{volatile-root?} is true, the root file system is writable but any changes
30990 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
30991 [#:mapped-devices '()] [#:keyboard-layout #f] @
30992 [#:qemu-networking? #f] [#:volatile-root? #f] @
30993 [#:linux-modules '()]
30994 Return as a file-like object a generic initrd, with kernel
30995 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
30996 mounted by the initrd, possibly in addition to the root file system specified
30997 on the kernel command line via @option{--root}. @var{mapped-devices} is a list of device
30998 mappings to realize before @var{file-systems} are mounted.
31000 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
31001 the desired console keyboard layout. This is done before @var{mapped-devices}
31002 are set up and before @var{file-systems} are mounted such that, should the
31003 user need to enter a passphrase or use the REPL, this happens using the
31004 intended keyboard layout.
31006 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
31008 The initrd is automatically populated with all the kernel modules necessary
31009 for @var{file-systems} and for the given options. Additional kernel
31010 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
31011 loaded at boot time in the order in which they appear.
31014 Needless to say, the initrds we produce and use embed a
31015 statically-linked Guile, and the initialization program is a Guile
31016 program. That gives a lot of flexibility. The
31017 @code{expression->initrd} procedure builds such an initrd, given the
31018 program to run in that initrd.
31020 @deffn {Scheme Procedure} expression->initrd @var{exp} @
31021 [#:guile %guile-3.0-static-stripped] [#:name "guile-initrd"]
31022 Return as a file-like object a Linux initrd (a gzipped cpio archive)
31023 containing @var{guile} and that evaluates @var{exp}, a G-expression,
31024 upon booting. All the derivations referenced by @var{exp} are
31025 automatically copied to the initrd.
31028 @node Bootloader Configuration
31029 @section Bootloader Configuration
31032 @cindex boot loader
31034 The operating system supports multiple bootloaders. The bootloader is
31035 configured using @code{bootloader-configuration} declaration. All the
31036 fields of this structure are bootloader agnostic except for one field,
31037 @code{bootloader} that indicates the bootloader to be configured and
31040 Some of the bootloaders do not honor every field of
31041 @code{bootloader-configuration}. For instance, the extlinux
31042 bootloader does not support themes and thus ignores the @code{theme}
31045 @deftp {Data Type} bootloader-configuration
31046 The type of a bootloader configuration declaration.
31050 @item @code{bootloader}
31051 @cindex EFI, bootloader
31052 @cindex UEFI, bootloader
31053 @cindex BIOS, bootloader
31054 The bootloader to use, as a @code{bootloader} object. For now
31055 @code{grub-bootloader}, @code{grub-efi-bootloader},
31056 @code{grub-efi-netboot-bootloader}, @code{extlinux-bootloader} and
31057 @code{u-boot-bootloader} are supported.
31059 @cindex ARM, bootloaders
31060 @cindex AArch64, bootloaders
31061 Available bootloaders are described in @code{(gnu bootloader @dots{})}
31062 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
31063 of bootloaders for a wide range of ARM and AArch64 systems, using the
31064 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
31066 @vindex grub-efi-bootloader
31067 @code{grub-efi-bootloader} allows to boot on modern systems using the
31068 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
31069 use if the installation image contains a @file{/sys/firmware/efi} directory
31070 when you boot it on your system.
31072 @vindex grub-bootloader
31073 @code{grub-bootloader} allows you to boot in particular Intel-based machines
31074 in ``legacy'' BIOS mode.
31076 @vindex grub-efi-netboot-bootloader
31077 @code{grub-efi-netboot-bootloader} allows you to boot your system over network
31078 through TFTP@. In combination with an NFS root file system this allows you to
31079 build a diskless Guix system.
31081 The installation of the @code{grub-efi-netboot-bootloader} generates the content
31082 of the TFTP root directory at @code{target}
31083 (@pxref{Bootloader Configuration, @code{target}}), to be served by a TFTP server.
31084 You may want to mount your TFTP server directory onto @code{target} to move the
31085 required files to the TFTP server automatically.
31087 If you plan to use an NFS root file system as well (actually if you mount the
31088 store from an NFS share), then the TFTP server needs to serve the file
31089 @file{/boot/grub/grub.cfg} and other files from the store (like GRUBs background
31090 image, the kernel (@pxref{operating-system Reference, @code{kernel}}) and the
31091 initrd (@pxref{operating-system Reference, @code{initrd}})), too. All these
31092 files from the store will be accessed by GRUB through TFTP with their normal
31093 store path, for example as
31094 @file{tftp://tftp-server/gnu/store/…-initrd/initrd.cpio.gz}.
31096 Two symlinks are created to make this possible. The first symlink is
31097 @code{target}@file{/efi/Guix/boot/grub/grub.cfg} pointing to
31098 @file{../../../boot/grub/grub.cfg},
31099 where @code{target} may be @file{/boot}. In this case the link is not leaving
31100 the served TFTP root directory, but otherwise it does. The second link is
31101 @code{target}@file{/gnu/store} and points to @file{../gnu/store}. This link
31102 is leaving the served TFTP root directory.
31104 The assumption behind all this is that you have an NFS server exporting the root
31105 file system for your Guix system, and additionally a TFTP server exporting your
31106 @code{target} directory—usually @file{/boot}—from that same root file system for
31107 your Guix system. In this constellation the symlinks will work.
31109 For other constellations you will have to program your own bootloader installer,
31110 which then takes care to make necessary files from the store accessible through
31111 TFTP, for example by copying them into the TFTP root directory at @code{target}.
31113 It is important to note that symlinks pointing outside the TFTP root directory
31114 may need to be allowed in the configuration of your TFTP server. Further the
31115 store link exposes the whole store through TFTP@. Both points need to be
31116 considered carefully for security aspects.
31118 Beside the @code{grub-efi-netboot-bootloader}, the already mentioned TFTP and
31119 NFS servers, you also need a properly configured DHCP server to make the booting
31120 over netboot possible. For all this we can currently only recommend you to look
31121 for instructions about @acronym{PXE, Preboot eXecution Environment}.
31123 @item @code{target}
31124 This is a string denoting the target onto which to install the
31127 The interpretation depends on the bootloader in question. For
31128 @code{grub-bootloader}, for example, it should be a device name understood by
31129 the bootloader @command{installer} command, such as @code{/dev/sda} or
31130 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
31131 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
31132 system, usually @file{/boot/efi}. For @code{grub-efi-netboot-bootloader},
31133 @code{target} should be the mount point corresponding to the TFTP root
31134 directory of your TFTP server.
31136 @item @code{menu-entries} (default: @code{()})
31137 A possibly empty list of @code{menu-entry} objects (see below), denoting
31138 entries to appear in the bootloader menu, in addition to the current
31139 system entry and the entry pointing to previous system generations.
31141 @item @code{default-entry} (default: @code{0})
31142 The index of the default boot menu entry. Index 0 is for the entry of the
31145 @item @code{timeout} (default: @code{5})
31146 The number of seconds to wait for keyboard input before booting. Set to
31147 0 to boot immediately, and to -1 to wait indefinitely.
31149 @cindex keyboard layout, for the bootloader
31150 @item @code{keyboard-layout} (default: @code{#f})
31151 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
31152 layout, usually US@tie{}English (``qwerty'').
31154 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
31158 This option is currently ignored by bootloaders other than @code{grub} and
31162 @item @code{theme} (default: @var{#f})
31163 The bootloader theme object describing the theme to use. If no theme
31164 is provided, some bootloaders might use a default theme, that's true
31167 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
31168 The output terminals used for the bootloader boot menu, as a list of
31169 symbols. GRUB accepts the values: @code{console}, @code{serial},
31170 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
31171 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
31172 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
31173 configuration,,, grub,GNU GRUB manual}).
31175 @item @code{terminal-inputs} (default: @code{'()})
31176 The input terminals used for the bootloader boot menu, as a list of
31177 symbols. For GRUB, the default is the native platform terminal as
31178 determined at run-time. GRUB accepts the values: @code{console},
31179 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
31180 @code{usb_keyboard}. This field corresponds to the GRUB variable
31181 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
31184 @item @code{serial-unit} (default: @code{#f})
31185 The serial unit used by the bootloader, as an integer from 0 to 3.
31186 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
31187 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
31189 @item @code{serial-speed} (default: @code{#f})
31190 The speed of the serial interface, as an integer. For GRUB, the
31191 default value is chosen at run-time; currently GRUB chooses
31192 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
31199 Should you want to list additional boot menu entries @i{via} the
31200 @code{menu-entries} field above, you will need to create them with the
31201 @code{menu-entry} form. For example, imagine you want to be able to
31202 boot another distro (hard to imagine!), you can define a menu entry
31207 (label "The Other Distro")
31208 (linux "/boot/old/vmlinux-2.6.32")
31209 (linux-arguments '("root=/dev/sda2"))
31210 (initrd "/boot/old/initrd"))
31215 @deftp {Data Type} menu-entry
31216 The type of an entry in the bootloader menu.
31221 The label to show in the menu---e.g., @code{"GNU"}.
31223 @item @code{linux} (default: @code{#f})
31224 The Linux kernel image to boot, for example:
31227 (file-append linux-libre "/bzImage")
31230 For GRUB, it is also possible to specify a device explicitly in the
31231 file path using GRUB's device naming convention (@pxref{Naming
31232 convention,,, grub, GNU GRUB manual}), for example:
31235 "(hd0,msdos1)/boot/vmlinuz"
31238 If the device is specified explicitly as above, then the @code{device}
31239 field is ignored entirely.
31241 @item @code{linux-arguments} (default: @code{()})
31242 The list of extra Linux kernel command-line arguments---e.g.,
31243 @code{("console=ttyS0")}.
31245 @item @code{initrd} (default: @code{#f})
31246 A G-Expression or string denoting the file name of the initial RAM disk
31247 to use (@pxref{G-Expressions}).
31249 @item @code{device} (default: @code{#f})
31250 The device where the kernel and initrd are to be found---i.e., for GRUB,
31251 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
31253 This may be a file system label (a string), a file system UUID (a
31254 bytevector, @pxref{File Systems}), or @code{#f}, in which case
31255 the bootloader will search the device containing the file specified by
31256 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
31257 must @emph{not} be an OS device name such as @file{/dev/sda1}.
31259 @item @code{multiboot-kernel} (default: @code{#f})
31260 The kernel to boot in Multiboot-mode (@pxref{multiboot,,, grub, GNU GRUB
31261 manual}). When this field is set, a Multiboot menu-entry is generated.
31265 (file-append mach "/boot/gnumach")
31268 @item @code{multiboot-arguments} (default: @code{()})
31269 The list of extra command-line arguments for the multiboot-kernel.
31271 @item @code{multiboot-modules} (default: @code{()})
31272 The list of commands for loading Multiboot modules. For example:
31275 (list (list (file-append hurd "/hurd/ext2fs.static") "ext2fs"
31277 (list (file-append libc "/lib/ld.so.1") "exec"
31287 @c FIXME: Write documentation once it's stable.
31288 For now only GRUB has theme support. GRUB themes are created using
31289 the @code{grub-theme} form, which is not fully documented yet.
31291 @deftp {Data Type} grub-theme
31292 Data type representing the configuration of the GRUB theme.
31295 @item @code{gfxmode} (default: @code{'("auto")})
31296 The GRUB @code{gfxmode} to set (a list of screen resolution strings,
31297 @pxref{gfxmode,,, grub, GNU GRUB manual}).
31301 @deffn {Scheme Procedure} grub-theme
31302 Return the default GRUB theme used by the operating system if no
31303 @code{theme} field is specified in @code{bootloader-configuration}
31306 It comes with a fancy background image displaying the GNU and Guix
31310 For example, to override the default resolution, you may use something
31315 (bootloader-configuration
31318 (inherit (grub-theme))
31319 (gfxmode '("1024x786x32" "auto"))))))
31322 @node Invoking guix system
31323 @section Invoking @code{guix system}
31325 Once you have written an operating system declaration as seen in the
31326 previous section, it can be @dfn{instantiated} using the @command{guix
31327 system} command. The synopsis is:
31330 guix system @var{options}@dots{} @var{action} @var{file}
31333 @var{file} must be the name of a file containing an
31334 @code{operating-system} declaration. @var{action} specifies how the
31335 operating system is instantiated. Currently the following values are
31340 Display available service type definitions that match the given regular
31341 expressions, sorted by relevance:
31347 $ guix system search console
31348 name: console-fonts
31349 location: gnu/services/base.scm:806:2
31350 extends: shepherd-root
31351 description: Install the given fonts on the specified ttys (fonts are per
31352 + virtual console on GNU/Linux). The value of this service is a list of
31353 + tty/font pairs. The font can be the name of a font provided by the `kbd'
31354 + package or any valid argument to `setfont', as in this example:
31356 + '(("tty1" . "LatGrkCyr-8x16")
31357 + ("tty2" . (file-append
31359 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
31360 + ("tty3" . (file-append
31362 + "/share/consolefonts/ter-132n"))) ; for HDPI
31366 location: gnu/services/base.scm:1190:2
31367 extends: shepherd-root
31368 description: Provide console login using the `mingetty' program.
31372 location: gnu/services/base.scm:860:2
31374 description: Provide a console log-in service as specified by its
31375 + configuration value, a `login-configuration' object.
31381 As for @command{guix package --search}, the result is written in
31382 @code{recutils} format, which makes it easy to filter the output
31383 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
31386 Build the operating system described in @var{file}, activate it, and
31387 switch to it@footnote{This action (and the related actions
31388 @code{switch-generation} and @code{roll-back}) are usable only on
31389 systems already running Guix System.}.
31392 @c The paragraph below refers to the problem discussed at
31393 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
31394 It is highly recommended to run @command{guix pull} once before you run
31395 @command{guix system reconfigure} for the first time (@pxref{Invoking
31396 guix pull}). Failing to do that you would see an older version of Guix
31397 once @command{reconfigure} has completed.
31400 This effects all the configuration specified in @var{file}: user
31401 accounts, system services, global package list, setuid programs, etc.
31402 The command starts system services specified in @var{file} that are not
31403 currently running; if a service is currently running this command will
31404 arrange for it to be upgraded the next time it is stopped (e.g.@: by
31405 @code{herd stop X} or @code{herd restart X}).
31407 This command creates a new generation whose number is one greater than
31408 the current generation (as reported by @command{guix system
31409 list-generations}). If that generation already exists, it will be
31410 overwritten. This behavior mirrors that of @command{guix package}
31411 (@pxref{Invoking guix package}).
31413 It also adds a bootloader menu entry for the new OS configuration,
31414 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
31415 entries for older configurations to a submenu, allowing you to choose
31416 an older system generation at boot time should you need it.
31418 @cindex provenance tracking, of the operating system
31419 Upon completion, the new system is deployed under
31420 @file{/run/current-system}. This directory contains @dfn{provenance
31421 meta-data}: the list of channels in use (@pxref{Channels}) and
31422 @var{file} itself, when available. You can view it by running:
31425 guix system describe
31428 This information is useful should you later want to inspect how this
31429 particular generation was built. In fact, assuming @var{file} is
31430 self-contained, you can later rebuild generation @var{n} of your
31431 operating system with:
31434 guix time-machine \
31435 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
31436 system reconfigure \
31437 /var/guix/profiles/system-@var{n}-link/configuration.scm
31440 You can think of it as some sort of built-in version control! Your
31441 system is not just a binary artifact: @emph{it carries its own source}.
31442 @xref{Service Reference, @code{provenance-service-type}}, for more
31443 information on provenance tracking.
31445 By default, @command{reconfigure} @emph{prevents you from downgrading
31446 your system}, which could (re)introduce security vulnerabilities and
31447 also cause problems with ``stateful'' services such as database
31448 management systems. You can override that behavior by passing
31449 @option{--allow-downgrades}.
31451 @item switch-generation
31452 @cindex generations
31453 Switch to an existing system generation. This action atomically
31454 switches the system profile to the specified system generation. It
31455 also rearranges the system's existing bootloader menu entries. It
31456 makes the menu entry for the specified system generation the default,
31457 and it moves the entries for the other generations to a submenu, if
31458 supported by the bootloader being used. The next time the system
31459 boots, it will use the specified system generation.
31461 The bootloader itself is not being reinstalled when using this
31462 command. Thus, the installed bootloader is used with an updated
31463 configuration file.
31465 The target generation can be specified explicitly by its generation
31466 number. For example, the following invocation would switch to system
31470 guix system switch-generation 7
31473 The target generation can also be specified relative to the current
31474 generation with the form @code{+N} or @code{-N}, where @code{+3} means
31475 ``3 generations ahead of the current generation,'' and @code{-1} means
31476 ``1 generation prior to the current generation.'' When specifying a
31477 negative value such as @code{-1}, you must precede it with @code{--} to
31478 prevent it from being parsed as an option. For example:
31481 guix system switch-generation -- -1
31484 Currently, the effect of invoking this action is @emph{only} to switch
31485 the system profile to an existing generation and rearrange the
31486 bootloader menu entries. To actually start using the target system
31487 generation, you must reboot after running this action. In the future,
31488 it will be updated to do the same things as @command{reconfigure},
31489 like activating and deactivating services.
31491 This action will fail if the specified generation does not exist.
31494 @cindex rolling back
31495 Switch to the preceding system generation. The next time the system
31496 boots, it will use the preceding system generation. This is the inverse
31497 of @command{reconfigure}, and it is exactly the same as invoking
31498 @command{switch-generation} with an argument of @code{-1}.
31500 Currently, as with @command{switch-generation}, you must reboot after
31501 running this action to actually start using the preceding system
31504 @item delete-generations
31505 @cindex deleting system generations
31506 @cindex saving space
31507 Delete system generations, making them candidates for garbage collection
31508 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
31511 This works in the same way as @samp{guix package --delete-generations}
31512 (@pxref{Invoking guix package, @option{--delete-generations}}). With no
31513 arguments, all system generations but the current one are deleted:
31516 guix system delete-generations
31519 You can also select the generations you want to delete. The example below
31520 deletes all the system generations that are more than two month old:
31523 guix system delete-generations 2m
31526 Running this command automatically reinstalls the bootloader with an updated
31527 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
31528 longer lists the generations that have been deleted.
31531 Build the derivation of the operating system, which includes all the
31532 configuration files and programs needed to boot and run the system.
31533 This action does not actually install anything.
31536 Populate the given directory with all the files necessary to run the
31537 operating system specified in @var{file}. This is useful for first-time
31538 installations of Guix System. For instance:
31541 guix system init my-os-config.scm /mnt
31544 copies to @file{/mnt} all the store items required by the configuration
31545 specified in @file{my-os-config.scm}. This includes configuration
31546 files, packages, and so on. It also creates other essential files
31547 needed for the system to operate correctly---e.g., the @file{/etc},
31548 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
31550 This command also installs bootloader on the target specified in
31551 @file{my-os-config}, unless the @option{--no-bootloader} option was
31555 @cindex virtual machine
31557 @anchor{guix system vm}
31558 Build a virtual machine that contains the operating system declared in
31559 @var{file}, and return a script to run that virtual machine (VM).
31562 The @code{vm} action and others below
31563 can use KVM support in the Linux-libre kernel. Specifically, if the
31564 machine has hardware virtualization support, the corresponding
31565 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
31566 must exist and be readable and writable by the user and by the
31567 build users of the daemon (@pxref{Build Environment Setup}).
31570 Arguments given to the script are passed to QEMU as in the example
31571 below, which enables networking and requests 1@tie{}GiB of RAM for the
31575 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
31578 The VM shares its store with the host system.
31580 Additional file systems can be shared between the host and the VM using
31581 the @option{--share} and @option{--expose} command-line options: the former
31582 specifies a directory to be shared with write access, while the latter
31583 provides read-only access to the shared directory.
31585 The example below creates a VM in which the user's home directory is
31586 accessible read-only, and where the @file{/exchange} directory is a
31587 read-write mapping of @file{$HOME/tmp} on the host:
31590 guix system vm my-config.scm \
31591 --expose=$HOME --share=$HOME/tmp=/exchange
31594 On GNU/Linux, the default is to boot directly to the kernel; this has
31595 the advantage of requiring only a very tiny root disk image since the
31596 store of the host can then be mounted.
31598 The @option{--full-boot} option forces a complete boot sequence, starting
31599 with the bootloader. This requires more disk space since a root image
31600 containing at least the kernel, initrd, and bootloader data files must
31601 be created. The @option{--image-size} option can be used to specify the
31604 @cindex System images, creation in various formats
31605 @cindex Creating system images in various formats
31608 @itemx docker-image
31609 Return a virtual machine, disk image, or Docker image of the operating
31610 system declared in @var{file} that stands alone. By default,
31611 @command{guix system} estimates the size of the image needed to store
31612 the system, but you can use the @option{--image-size} option to specify
31613 a value. Docker images are built to contain exactly what they need, so
31614 the @option{--image-size} option is ignored in the case of
31615 @code{docker-image}.
31617 @cindex image, creating disk images
31618 The @code{image} command can produce various image types. The
31619 image type can be selected using the @option{--image-type} option. It
31620 defaults to @code{efi-raw}. When its value is @code{iso9660}, the
31621 @option{--label} option can be used to specify a volume ID with
31622 @code{image}. By default, the root file system of a disk image is
31623 mounted non-volatile; the @option{--volatile} option can be provided to
31624 make it volatile instead. When using @code{image}, the bootloader
31625 installed on the generated image is taken from the provided
31626 @code{operating-system} definition. The following example demonstrates
31627 how to generate an image that uses the @code{grub-efi-bootloader}
31628 bootloader and boot it with QEMU:
31631 image=$(guix system image --image-type=qcow2 \
31632 gnu/system/examples/lightweight-desktop.tmpl)
31633 cp $image /tmp/my-image.qcow2
31634 chmod +w /tmp/my-image.qcow2
31635 qemu-system-x86_64 -enable-kvm -hda /tmp/my-image.qcow2 -m 1000 \
31636 -bios $(guix build ovmf)/share/firmware/ovmf_x64.bin
31639 When using the @code{efi-raw} image type, a raw disk image is produced;
31640 it can be copied as is to a USB stick, for instance. Assuming
31641 @code{/dev/sdc} is the device corresponding to a USB stick, one can copy
31642 the image to it using the following command:
31645 # dd if=$(guix system image my-os.scm) of=/dev/sdc status=progress
31648 The @code{--list-image-types} command lists all the available image
31651 @cindex vm-image, creating virtual machine images
31652 When using @code{vm-image}, the returned image is in qcow2 format, which
31653 the QEMU emulator can efficiently use. @xref{Running Guix in a VM}, for
31654 more information on how to run the image in a virtual machine. The
31655 @code{grub-bootloader} bootloader is always used independently of what
31656 is declared in the @code{operating-system} file passed as argument.
31657 This is to make it easier to work with QEMU, which uses the SeaBIOS BIOS
31658 by default, expecting a bootloader to be installed in the Master Boot
31661 @cindex docker-image, creating docker images
31662 When using @code{docker-image}, a Docker image is produced. Guix builds
31663 the image from scratch, not from a pre-existing Docker base image. As a
31664 result, it contains @emph{exactly} what you define in the operating
31665 system configuration file. You can then load the image and launch a
31666 Docker container using commands like the following:
31669 image_id="`docker load < guix-system-docker-image.tar.gz`"
31670 container_id="`docker create $image_id`"
31671 docker start $container_id
31674 This command starts a new Docker container from the specified image. It
31675 will boot the Guix system in the usual manner, which means it will
31676 start any services you have defined in the operating system
31677 configuration. You can get an interactive shell running in the container
31678 using @command{docker exec}:
31681 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
31684 Depending on what you run in the Docker container, it
31685 may be necessary to give the container additional permissions. For
31686 example, if you intend to build software using Guix inside of the Docker
31687 container, you may need to pass the @option{--privileged} option to
31688 @code{docker create}.
31690 Last, the @option{--network} option applies to @command{guix system
31691 docker-image}: it produces an image where network is supposedly shared
31692 with the host, and thus without services like nscd or NetworkManager.
31695 Return a script to run the operating system declared in @var{file}
31696 within a container. Containers are a set of lightweight isolation
31697 mechanisms provided by the kernel Linux-libre. Containers are
31698 substantially less resource-demanding than full virtual machines since
31699 the kernel, shared objects, and other resources can be shared with the
31700 host system; this also means they provide thinner isolation.
31702 Currently, the script must be run as root in order to support more than
31703 a single user and group. The container shares its store with the host
31706 As with the @code{vm} action (@pxref{guix system vm}), additional file
31707 systems to be shared between the host and container can be specified
31708 using the @option{--share} and @option{--expose} options:
31711 guix system container my-config.scm \
31712 --expose=$HOME --share=$HOME/tmp=/exchange
31716 This option requires Linux-libre 3.19 or newer.
31721 @var{options} can contain any of the common build options (@pxref{Common
31722 Build Options}). In addition, @var{options} can contain one of the
31726 @item --expression=@var{expr}
31727 @itemx -e @var{expr}
31728 Consider the operating-system @var{expr} evaluates to.
31729 This is an alternative to specifying a file which evaluates to an
31731 This is used to generate the Guix system installer @pxref{Building the
31732 Installation Image}).
31734 @item --system=@var{system}
31735 @itemx -s @var{system}
31736 Attempt to build for @var{system} instead of the host system type.
31737 This works as per @command{guix build} (@pxref{Invoking guix build}).
31741 Return the derivation file name of the given operating system without
31744 @cindex provenance tracking, of the operating system
31745 @item --save-provenance
31746 As discussed above, @command{guix system init} and @command{guix system
31747 reconfigure} always save provenance information @i{via} a dedicated
31748 service (@pxref{Service Reference, @code{provenance-service-type}}).
31749 However, other commands don't do that by default. If you wish to, say,
31750 create a virtual machine image that contains provenance information, you
31754 guix system vm-image --save-provenance config.scm
31757 That way, the resulting image will effectively ``embed its own source''
31758 in the form of meta-data in @file{/run/current-system}. With that
31759 information, one can rebuild the image to make sure it really contains
31760 what it pretends to contain; or they could use that to derive a variant
31763 @item --image-type=@var{type}
31764 @itemx -t @var{type}
31765 For the @code{image} action, create an image with given @var{type}.
31767 When this option is omitted, @command{guix system} uses the
31768 @code{efi-raw} image type.
31770 @cindex ISO-9660 format
31771 @cindex CD image format
31772 @cindex DVD image format
31773 @option{--image-type=iso9660} produces an ISO-9660 image, suitable
31774 for burning on CDs and DVDs.
31776 @item --image-size=@var{size}
31777 For the @code{vm-image} and @code{image} actions, create an image
31778 of the given @var{size}. @var{size} may be a number of bytes, or it may
31779 include a unit as a suffix (@pxref{Block size, size specifications,,
31780 coreutils, GNU Coreutils}).
31782 When this option is omitted, @command{guix system} computes an estimate
31783 of the image size as a function of the size of the system declared in
31788 For the @code{container} action, allow containers to access the host network,
31789 that is, do not create a network namespace.
31791 @item --root=@var{file}
31792 @itemx -r @var{file}
31793 Make @var{file} a symlink to the result, and register it as a garbage
31796 @item --skip-checks
31797 Skip pre-installation safety checks.
31799 By default, @command{guix system init} and @command{guix system
31800 reconfigure} perform safety checks: they make sure the file systems that
31801 appear in the @code{operating-system} declaration actually exist
31802 (@pxref{File Systems}), and that any Linux kernel modules that may be
31803 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
31804 RAM Disk}). Passing this option skips these tests altogether.
31806 @item --allow-downgrades
31807 Instruct @command{guix system reconfigure} to allow system downgrades.
31809 By default, @command{reconfigure} prevents you from downgrading your
31810 system. It achieves that by comparing the provenance info of your
31811 system (shown by @command{guix system describe}) with that of your
31812 @command{guix} command (shown by @command{guix describe}). If the
31813 commits for @command{guix} are not descendants of those used for your
31814 system, @command{guix system reconfigure} errors out. Passing
31815 @option{--allow-downgrades} allows you to bypass these checks.
31818 Make sure you understand its security implications before using
31819 @option{--allow-downgrades}.
31823 @cindex on-error strategy
31824 @cindex error strategy
31825 @item --on-error=@var{strategy}
31826 Apply @var{strategy} when an error occurs when reading @var{file}.
31827 @var{strategy} may be one of the following:
31830 @item nothing-special
31831 Report the error concisely and exit. This is the default strategy.
31834 Likewise, but also display a backtrace.
31837 Report the error and enter Guile's debugger. From there, you can run
31838 commands such as @code{,bt} to get a backtrace, @code{,locals} to
31839 display local variable values, and more generally inspect the state of the
31840 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
31841 a list of available debugging commands.
31845 Once you have built, configured, re-configured, and re-re-configured
31846 your Guix installation, you may find it useful to list the operating
31847 system generations available on disk---and that you can choose from the
31848 bootloader boot menu:
31853 Describe the current system generation: its file name, the kernel and
31854 bootloader used, etc., as well as provenance information when available.
31856 @item list-generations
31857 List a summary of each generation of the operating system available on
31858 disk, in a human-readable way. This is similar to the
31859 @option{--list-generations} option of @command{guix package}
31860 (@pxref{Invoking guix package}).
31862 Optionally, one can specify a pattern, with the same syntax that is used
31863 in @command{guix package --list-generations}, to restrict the list of
31864 generations displayed. For instance, the following command displays
31865 generations that are up to 10 days old:
31868 $ guix system list-generations 10d
31873 The @command{guix system} command has even more to offer! The following
31874 sub-commands allow you to visualize how your system services relate to
31877 @anchor{system-extension-graph}
31880 @item extension-graph
31881 Emit to standard output the @dfn{service
31882 extension graph} of the operating system defined in @var{file}
31883 (@pxref{Service Composition}, for more information on service
31884 extensions). By default the output is in Dot/Graphviz format, but you
31885 can choose a different format with @option{--graph-backend}, as with
31886 @command{guix graph} (@pxref{Invoking guix graph, @option{--backend}}):
31891 $ guix system extension-graph @var{file} | xdot -
31894 shows the extension relations among services.
31896 @anchor{system-shepherd-graph}
31897 @item shepherd-graph
31898 Emit to standard output the @dfn{dependency
31899 graph} of shepherd services of the operating system defined in
31900 @var{file}. @xref{Shepherd Services}, for more information and for an
31903 Again, the default output format is Dot/Graphviz, but you can pass
31904 @option{--graph-backend} to select a different one.
31908 @node Invoking guix deploy
31909 @section Invoking @code{guix deploy}
31911 We've already seen @code{operating-system} declarations used to manage a
31912 machine's configuration locally. Suppose you need to configure multiple
31913 machines, though---perhaps you're managing a service on the web that's
31914 comprised of several servers. @command{guix deploy} enables you to use those
31915 same @code{operating-system} declarations to manage multiple remote hosts at
31916 once as a logical ``deployment''.
31919 The functionality described in this section is still under development
31920 and is subject to change. Get in touch with us on
31921 @email{guix-devel@@gnu.org}!
31925 guix deploy @var{file}
31928 Such an invocation will deploy the machines that the code within @var{file}
31929 evaluates to. As an example, @var{file} might contain a definition like this:
31932 ;; This is a Guix deployment of a "bare bones" setup, with
31933 ;; no X11 display server, to a machine with an SSH daemon
31934 ;; listening on localhost:2222. A configuration such as this
31935 ;; may be appropriate for virtual machine with ports
31936 ;; forwarded to the host's loopback interface.
31938 (use-service-modules networking ssh)
31939 (use-package-modules bootloaders)
31943 (host-name "gnu-deployed")
31944 (timezone "Etc/UTC")
31945 (bootloader (bootloader-configuration
31946 (bootloader grub-bootloader)
31947 (target "/dev/vda")
31948 (terminal-outputs '(console))))
31949 (file-systems (cons (file-system
31951 (device "/dev/vda1")
31953 %base-file-systems))
31955 (append (list (service dhcp-client-service-type)
31956 (service openssh-service-type
31957 (openssh-configuration
31958 (permit-root-login #t)
31959 (allow-empty-passwords? #t))))
31963 (operating-system %system)
31964 (environment managed-host-environment-type)
31965 (configuration (machine-ssh-configuration
31966 (host-name "localhost")
31967 (system "x86_64-linux")
31969 (identity "./id_rsa")
31973 The file should evaluate to a list of @var{machine} objects. This example,
31974 upon being deployed, will create a new generation on the remote system
31975 realizing the @code{operating-system} declaration @code{%system}.
31976 @code{environment} and @code{configuration} specify how the machine should be
31977 provisioned---that is, how the computing resources should be created and
31978 managed. The above example does not create any resources, as a
31979 @code{'managed-host} is a machine that is already running the Guix system and
31980 available over the network. This is a particularly simple case; a more
31981 complex deployment may involve, for example, starting virtual machines through
31982 a Virtual Private Server (VPS) provider. In such a case, a different
31983 @var{environment} type would be used.
31985 Do note that you first need to generate a key pair on the coordinator machine
31986 to allow the daemon to export signed archives of files from the store
31987 (@pxref{Invoking guix archive}), though this step is automatic on Guix
31991 # guix archive --generate-key
31995 Each target machine must authorize the key of the master machine so that it
31996 accepts store items it receives from the coordinator:
31999 # guix archive --authorize < coordinator-public-key.txt
32002 @code{user}, in this example, specifies the name of the user account to log in
32003 as to perform the deployment. Its default value is @code{root}, but root
32004 login over SSH may be forbidden in some cases. To work around this,
32005 @command{guix deploy} can log in as an unprivileged user and employ
32006 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
32007 currently installed on the remote and can be invoked non-interactively as
32008 @code{user}. That is, the line in @code{sudoers} granting @code{user} the
32009 ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
32010 be accomplished with the following operating system configuration snippet:
32014 (gnu system)) ;for %sudoers-specification
32016 (define %user "username")
32021 (plain-file "sudoers"
32022 (string-append (plain-file-content %sudoers-specification)
32023 (format #f "~a ALL = NOPASSWD: ALL~%"
32028 For more information regarding the format of the @file{sudoers} file,
32029 consult @command{man sudoers}.
32031 @deftp {Data Type} machine
32032 This is the data type representing a single machine in a heterogeneous Guix
32036 @item @code{operating-system}
32037 The object of the operating system configuration to deploy.
32039 @item @code{environment}
32040 An @code{environment-type} describing how the machine should be provisioned.
32042 @item @code{configuration} (default: @code{#f})
32043 An object describing the configuration for the machine's @code{environment}.
32044 If the @code{environment} has a default configuration, @code{#f} may be used.
32045 If @code{#f} is used for an environment with no default configuration,
32046 however, an error will be thrown.
32050 @deftp {Data Type} machine-ssh-configuration
32051 This is the data type representing the SSH client parameters for a machine
32052 with an @code{environment} of @code{managed-host-environment-type}.
32055 @item @code{host-name}
32056 @item @code{build-locally?} (default: @code{#t})
32057 If false, system derivations will be built on the machine being deployed to.
32058 @item @code{system}
32059 The system type describing the architecture of the machine being deployed
32060 to---e.g., @code{"x86_64-linux"}.
32061 @item @code{authorize?} (default: @code{#t})
32062 If true, the coordinator's signing key will be added to the remote's ACL
32064 @item @code{port} (default: @code{22})
32065 @item @code{user} (default: @code{"root"})
32066 @item @code{identity} (default: @code{#f})
32067 If specified, the path to the SSH private key to use to authenticate with the
32070 @item @code{host-key} (default: @code{#f})
32071 This should be the SSH host key of the machine, which looks like this:
32074 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
32077 When @code{host-key} is @code{#f}, the server is authenticated against
32078 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
32081 @item @code{allow-downgrades?} (default: @code{#f})
32082 Whether to allow potential downgrades.
32084 Like @command{guix system reconfigure}, @command{guix deploy} compares
32085 the channel commits currently deployed on the remote host (as returned
32086 by @command{guix system describe}) to those currently in use (as
32087 returned by @command{guix describe}) to determine whether commits
32088 currently in use are descendants of those deployed. When this is not
32089 the case and @code{allow-downgrades?} is false, it raises an error.
32090 This ensures you do not accidentally downgrade remote machines.
32094 @deftp {Data Type} digital-ocean-configuration
32095 This is the data type describing the Droplet that should be created for a
32096 machine with an @code{environment} of @code{digital-ocean-environment-type}.
32099 @item @code{ssh-key}
32100 The path to the SSH private key to use to authenticate with the remote
32101 host. In the future, this field may not exist.
32103 A list of string ``tags'' that uniquely identify the machine. Must be given
32104 such that no two machines in the deployment have the same set of tags.
32105 @item @code{region}
32106 A Digital Ocean region slug, such as @code{"nyc3"}.
32108 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
32109 @item @code{enable-ipv6?}
32110 Whether or not the droplet should be created with IPv6 networking.
32114 @node Running Guix in a VM
32115 @section Running Guix in a Virtual Machine
32117 @cindex virtual machine
32118 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
32120 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
32121 This image is a compressed image in QCOW format. You will first need to
32122 decompress with @command{xz -d}, and then you can pass it to an emulator such
32123 as QEMU (see below for details).
32125 This image boots the Xfce graphical environment and it contains some
32126 commonly used tools. You can install more software in the image by running
32127 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
32128 also reconfigure the system based on its initial configuration file available
32129 as @file{/run/current-system/configuration.scm} (@pxref{Using the
32130 Configuration System}).
32132 Instead of using this pre-built image, one can also build their own virtual
32133 machine image using @command{guix system vm-image} (@pxref{Invoking guix
32134 system}). The returned image is in qcow2 format, which the
32135 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
32138 If you built your own image, you must copy it out of the store
32139 (@pxref{The Store}) and give yourself permission to write to the copy
32140 before you can use it. When invoking QEMU, you must choose a system
32141 emulator that is suitable for your hardware platform. Here is a minimal
32142 QEMU invocation that will boot the result of @command{guix system
32143 vm-image} on x86_64 hardware:
32146 $ qemu-system-x86_64 \
32147 -nic user,model=virtio-net-pci \
32148 -enable-kvm -m 1024 \
32149 -device virtio-blk,drive=myhd \
32150 -drive if=none,file=/tmp/qemu-image,id=myhd
32153 Here is what each of these options means:
32156 @item qemu-system-x86_64
32157 This specifies the hardware platform to emulate. This should match the
32160 @item -nic user,model=virtio-net-pci
32161 Enable the unprivileged user-mode network stack. The guest OS can
32162 access the host but not vice versa. This is the simplest way to get the
32163 guest OS online. @code{model} specifies which network device to emulate:
32164 @code{virtio-net-pci} is a special device made for virtualized operating
32165 systems and recommended for most uses. Assuming your hardware platform is
32166 x86_64, you can get a list of available NIC models by running
32167 @command{qemu-system-x86_64 -nic model=help}.
32170 If your system has hardware virtualization extensions, enabling the
32171 virtual machine support (KVM) of the Linux kernel will make things run
32174 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
32176 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
32177 which may be insufficient for some operations.
32179 @item -device virtio-blk,drive=myhd
32180 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
32181 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
32182 better performance than if it were emulating a complete disk drive. See the
32183 QEMU and KVM documentation for more info.
32185 @item -drive if=none,file=/tmp/qemu-image,id=myhd
32186 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing
32187 store of the ``myhd'' drive.
32190 The default @command{run-vm.sh} script that is returned by an invocation of
32191 @command{guix system vm} does not add a @command{-nic user} flag by default.
32192 To get network access from within the vm add the @code{(dhcp-client-service)}
32193 to your system definition and start the VM using
32194 @command{`guix system vm config.scm` -nic user}. An important caveat of using
32195 @command{-nic user} for networking is that @command{ping} will not work, because
32196 it uses the ICMP protocol. You'll have to use a different command to check for
32197 network connectivity, for example @command{guix download}.
32199 @subsection Connecting Through SSH
32203 To enable SSH inside a VM you need to add an SSH server like
32204 @code{openssh-service-type} to your VM (@pxref{Networking Services,
32205 @code{openssh-service-type}}). In addition you need to forward the SSH port,
32206 22 by default, to the host. You can do this with
32209 `guix system vm config.scm` -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
32212 To connect to the VM you can run
32215 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
32218 The @command{-p} tells @command{ssh} the port you want to connect to.
32219 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
32220 every time you modify your @command{config.scm} file and the
32221 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
32222 connection to an unknown host every time you connect.
32224 @subsection Using @command{virt-viewer} with Spice
32226 As an alternative to the default @command{qemu} graphical client you can
32227 use the @command{remote-viewer} from the @command{virt-viewer} package. To
32228 connect pass the @command{-spice port=5930,disable-ticketing} flag to
32229 @command{qemu}. See previous section for further information on how to do this.
32231 Spice also allows you to do some nice stuff like share your clipboard with your
32232 VM@. To enable that you'll also have to pass the following flags to @command{qemu}:
32235 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
32236 -chardev spicevmc,name=vdagent,id=vdagent
32237 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
32238 name=com.redhat.spice.0
32241 You'll also need to add the @code{(spice-vdagent-service)} to your
32242 system definition (@pxref{Miscellaneous Services, Spice service}).
32244 @node Defining Services
32245 @section Defining Services
32247 The previous sections show the available services and how one can combine
32248 them in an @code{operating-system} declaration. But how do we define
32249 them in the first place? And what is a service anyway?
32252 * Service Composition:: The model for composing services.
32253 * Service Types and Services:: Types and services.
32254 * Service Reference:: API reference.
32255 * Shepherd Services:: A particular type of service.
32258 @node Service Composition
32259 @subsection Service Composition
32263 Here we define a @dfn{service} as, broadly, something that extends the
32264 functionality of the operating system. Often a service is a process---a
32265 @dfn{daemon}---started when the system boots: a secure shell server, a
32266 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
32267 whose execution can be triggered by another daemon---e.g., an FTP server
32268 started by @command{inetd} or a D-Bus service activated by
32269 @command{dbus-daemon}. Occasionally, a service does not map to a
32270 daemon. For instance, the ``account'' service collects user accounts
32271 and makes sure they exist when the system runs; the ``udev'' service
32272 collects device management rules and makes them available to the eudev
32273 daemon; the @file{/etc} service populates the @file{/etc} directory
32276 @cindex service extensions
32277 Guix system services are connected by @dfn{extensions}. For instance, the
32278 secure shell service @emph{extends} the Shepherd---the
32279 initialization system, running as PID@tie{}1---by giving it the command
32280 lines to start and stop the secure shell daemon (@pxref{Networking
32281 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
32282 service by passing it its @file{.service} specification, and extends the
32283 udev service by passing it device management rules (@pxref{Desktop
32284 Services, @code{upower-service}}); the Guix daemon service extends the
32285 Shepherd by passing it the command lines to start and stop the daemon,
32286 and extends the account service by passing it a list of required build
32287 user accounts (@pxref{Base Services}).
32289 All in all, services and their ``extends'' relations form a directed
32290 acyclic graph (DAG). If we represent services as boxes and extensions
32291 as arrows, a typical system might provide something like this:
32293 @image{images/service-graph,,5in,Typical service extension graph.}
32295 @cindex system service
32296 At the bottom, we see the @dfn{system service}, which produces the
32297 directory containing everything to run and boot the system, as returned
32298 by the @command{guix system build} command. @xref{Service Reference},
32299 to learn about the other service types shown here.
32300 @xref{system-extension-graph, the @command{guix system extension-graph}
32301 command}, for information on how to generate this representation for a
32302 particular operating system definition.
32304 @cindex service types
32305 Technically, developers can define @dfn{service types} to express these
32306 relations. There can be any number of services of a given type on the
32307 system---for instance, a system running two instances of the GNU secure
32308 shell server (lsh) has two instances of @code{lsh-service-type}, with
32309 different parameters.
32311 The following section describes the programming interface for service
32312 types and services.
32314 @node Service Types and Services
32315 @subsection Service Types and Services
32317 A @dfn{service type} is a node in the DAG described above. Let us start
32318 with a simple example, the service type for the Guix build daemon
32319 (@pxref{Invoking guix-daemon}):
32322 (define guix-service-type
32326 (list (service-extension shepherd-root-service-type guix-shepherd-service)
32327 (service-extension account-service-type guix-accounts)
32328 (service-extension activation-service-type guix-activation)))
32329 (default-value (guix-configuration))))
32333 It defines three things:
32337 A name, whose sole purpose is to make inspection and debugging easier.
32340 A list of @dfn{service extensions}, where each extension designates the
32341 target service type and a procedure that, given the parameters of the
32342 service, returns a list of objects to extend the service of that type.
32344 Every service type has at least one service extension. The only
32345 exception is the @dfn{boot service type}, which is the ultimate service.
32348 Optionally, a default value for instances of this type.
32351 In this example, @code{guix-service-type} extends three services:
32354 @item shepherd-root-service-type
32355 The @code{guix-shepherd-service} procedure defines how the Shepherd
32356 service is extended. Namely, it returns a @code{<shepherd-service>}
32357 object that defines how @command{guix-daemon} is started and stopped
32358 (@pxref{Shepherd Services}).
32360 @item account-service-type
32361 This extension for this service is computed by @code{guix-accounts},
32362 which returns a list of @code{user-group} and @code{user-account}
32363 objects representing the build user accounts (@pxref{Invoking
32366 @item activation-service-type
32367 Here @code{guix-activation} is a procedure that returns a gexp, which is
32368 a code snippet to run at ``activation time''---e.g., when the service is
32372 A service of this type is instantiated like this:
32375 (service guix-service-type
32376 (guix-configuration
32378 (extra-options '("--gc-keep-derivations"))))
32381 The second argument to the @code{service} form is a value representing
32382 the parameters of this specific service instance.
32383 @xref{guix-configuration-type, @code{guix-configuration}}, for
32384 information about the @code{guix-configuration} data type. When the
32385 value is omitted, the default value specified by
32386 @code{guix-service-type} is used:
32389 (service guix-service-type)
32392 @code{guix-service-type} is quite simple because it extends other
32393 services but is not extensible itself.
32395 @c @subsubsubsection Extensible Service Types
32397 The service type for an @emph{extensible} service looks like this:
32400 (define udev-service-type
32401 (service-type (name 'udev)
32403 (list (service-extension shepherd-root-service-type
32404 udev-shepherd-service)))
32406 (compose concatenate) ;concatenate the list of rules
32407 (extend (lambda (config rules)
32409 (($ <udev-configuration> udev initial-rules)
32410 (udev-configuration
32411 (udev udev) ;the udev package to use
32412 (rules (append initial-rules rules)))))))))
32415 This is the service type for the
32416 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
32417 management daemon}. Compared to the previous example, in addition to an
32418 extension of @code{shepherd-root-service-type}, we see two new fields:
32422 This is the procedure to @dfn{compose} the list of extensions to
32423 services of this type.
32425 Services can extend the udev service by passing it lists of rules; we
32426 compose those extensions simply by concatenating them.
32429 This procedure defines how the value of the service is @dfn{extended} with
32430 the composition of the extensions.
32432 Udev extensions are composed into a list of rules, but the udev service
32433 value is itself a @code{<udev-configuration>} record. So here, we
32434 extend that record by appending the list of rules it contains to the
32435 list of contributed rules.
32438 This is a string giving an overview of the service type. The string can
32439 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
32440 @command{guix system search} command searches these strings and displays
32441 them (@pxref{Invoking guix system}).
32444 There can be only one instance of an extensible service type such as
32445 @code{udev-service-type}. If there were more, the
32446 @code{service-extension} specifications would be ambiguous.
32448 Still here? The next section provides a reference of the programming
32449 interface for services.
32451 @node Service Reference
32452 @subsection Service Reference
32454 We have seen an overview of service types (@pxref{Service Types and
32455 Services}). This section provides a reference on how to manipulate
32456 services and service types. This interface is provided by the
32457 @code{(gnu services)} module.
32459 @deffn {Scheme Procedure} service @var{type} [@var{value}]
32460 Return a new service of @var{type}, a @code{<service-type>} object (see
32461 below). @var{value} can be any object; it represents the parameters of
32462 this particular service instance.
32464 When @var{value} is omitted, the default value specified by @var{type}
32465 is used; if @var{type} does not specify a default value, an error is
32468 For instance, this:
32471 (service openssh-service-type)
32475 is equivalent to this:
32478 (service openssh-service-type
32479 (openssh-configuration))
32482 In both cases the result is an instance of @code{openssh-service-type}
32483 with the default configuration.
32486 @deffn {Scheme Procedure} service? @var{obj}
32487 Return true if @var{obj} is a service.
32490 @deffn {Scheme Procedure} service-kind @var{service}
32491 Return the type of @var{service}---i.e., a @code{<service-type>} object.
32494 @deffn {Scheme Procedure} service-value @var{service}
32495 Return the value associated with @var{service}. It represents its
32499 Here is an example of how a service is created and manipulated:
32503 (service nginx-service-type
32504 (nginx-configuration
32506 (log-directory log-directory)
32507 (run-directory run-directory)
32508 (file config-file))))
32513 (eq? (service-kind s) nginx-service-type)
32517 The @code{modify-services} form provides a handy way to change the
32518 parameters of some of the services of a list such as
32519 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
32520 evaluates to a list of services. Of course, you could always use
32521 standard list combinators such as @code{map} and @code{fold} to do that
32522 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
32523 @code{modify-services} simply provides a more concise form for this
32526 @deffn {Scheme Syntax} modify-services @var{services} @
32527 (@var{type} @var{variable} => @var{body}) @dots{}
32529 Modify the services listed in @var{services} according to the given
32530 clauses. Each clause has the form:
32533 (@var{type} @var{variable} => @var{body})
32536 where @var{type} is a service type---e.g.,
32537 @code{guix-service-type}---and @var{variable} is an identifier that is
32538 bound within the @var{body} to the service parameters---e.g., a
32539 @code{guix-configuration} instance---of the original service of that
32542 The @var{body} should evaluate to the new service parameters, which will
32543 be used to configure the new service. This new service will replace the
32544 original in the resulting list. Because a service's service parameters
32545 are created using @code{define-record-type*}, you can write a succinct
32546 @var{body} that evaluates to the new service parameters by using the
32547 @code{inherit} feature that @code{define-record-type*} provides.
32549 @xref{Using the Configuration System}, for example usage.
32553 Next comes the programming interface for service types. This is
32554 something you want to know when writing new service definitions, but not
32555 necessarily when simply looking for ways to customize your
32556 @code{operating-system} declaration.
32558 @deftp {Data Type} service-type
32559 @cindex service type
32560 This is the representation of a @dfn{service type} (@pxref{Service Types
32565 This is a symbol, used only to simplify inspection and debugging.
32567 @item @code{extensions}
32568 A non-empty list of @code{<service-extension>} objects (see below).
32570 @item @code{compose} (default: @code{#f})
32571 If this is @code{#f}, then the service type denotes services that cannot
32572 be extended---i.e., services that do not receive ``values'' from other
32575 Otherwise, it must be a one-argument procedure. The procedure is called
32576 by @code{fold-services} and is passed a list of values collected from
32577 extensions. It may return any single value.
32579 @item @code{extend} (default: @code{#f})
32580 If this is @code{#f}, services of this type cannot be extended.
32582 Otherwise, it must be a two-argument procedure: @code{fold-services}
32583 calls it, passing it the initial value of the service as the first
32584 argument and the result of applying @code{compose} to the extension
32585 values as the second argument. It must return a value that is a valid
32586 parameter value for the service instance.
32588 @item @code{description}
32589 This is a string, possibly using Texinfo markup, describing in a couple
32590 of sentences what the service is about. This string allows users to
32591 find about the service through @command{guix system search}
32592 (@pxref{Invoking guix system}).
32594 @item @code{default-value} (default: @code{&no-default-value})
32595 The default value associated for instances of this service type. This
32596 allows users to use the @code{service} form without its second argument:
32599 (service @var{type})
32602 The returned service in this case has the default value specified by
32606 @xref{Service Types and Services}, for examples.
32609 @deffn {Scheme Procedure} service-extension @var{target-type} @
32611 Return a new extension for services of type @var{target-type}.
32612 @var{compute} must be a one-argument procedure: @code{fold-services}
32613 calls it, passing it the value associated with the service that provides
32614 the extension; it must return a valid value for the target service.
32617 @deffn {Scheme Procedure} service-extension? @var{obj}
32618 Return true if @var{obj} is a service extension.
32621 Occasionally, you might want to simply extend an existing service. This
32622 involves creating a new service type and specifying the extension of
32623 interest, which can be verbose; the @code{simple-service} procedure
32624 provides a shorthand for this.
32626 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
32627 Return a service that extends @var{target} with @var{value}. This works
32628 by creating a singleton service type @var{name}, of which the returned
32629 service is an instance.
32631 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
32635 (simple-service 'my-mcron-job mcron-service-type
32636 #~(job '(next-hour (3)) "guix gc -F 2G"))
32640 At the core of the service abstraction lies the @code{fold-services}
32641 procedure, which is responsible for ``compiling'' a list of services
32642 down to a single directory that contains everything needed to boot and
32643 run the system---the directory shown by the @command{guix system build}
32644 command (@pxref{Invoking guix system}). In essence, it propagates
32645 service extensions down the service graph, updating each node parameters
32646 on the way, until it reaches the root node.
32648 @deffn {Scheme Procedure} fold-services @var{services} @
32649 [#:target-type @var{system-service-type}]
32650 Fold @var{services} by propagating their extensions down to the root of
32651 type @var{target-type}; return the root service adjusted accordingly.
32654 Lastly, the @code{(gnu services)} module also defines several essential
32655 service types, some of which are listed below.
32657 @defvr {Scheme Variable} system-service-type
32658 This is the root of the service graph. It produces the system directory
32659 as returned by the @command{guix system build} command.
32662 @defvr {Scheme Variable} boot-service-type
32663 The type of the ``boot service'', which produces the @dfn{boot script}.
32664 The boot script is what the initial RAM disk runs when booting.
32667 @defvr {Scheme Variable} etc-service-type
32668 The type of the @file{/etc} service. This service is used to create
32669 files under @file{/etc} and can be extended by
32670 passing it name/file tuples such as:
32673 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
32676 In this example, the effect would be to add an @file{/etc/issue} file
32677 pointing to the given file.
32680 @defvr {Scheme Variable} setuid-program-service-type
32681 Type for the ``setuid-program service''. This service collects lists of
32682 executable file names, passed as gexps, and adds them to the set of
32683 setuid-root programs on the system (@pxref{Setuid Programs}).
32686 @defvr {Scheme Variable} profile-service-type
32687 Type of the service that populates the @dfn{system profile}---i.e., the
32688 programs under @file{/run/current-system/profile}. Other services can
32689 extend it by passing it lists of packages to add to the system profile.
32692 @cindex provenance tracking, of the operating system
32693 @anchor{provenance-service-type}
32694 @defvr {Scheme Variable} provenance-service-type
32695 This is the type of the service that records @dfn{provenance meta-data}
32696 in the system itself. It creates several files under
32697 @file{/run/current-system}:
32701 This is a ``channel file'' that can be passed to @command{guix pull -C}
32702 or @command{guix time-machine -C}, and which describes the channels used
32703 to build the system, if that information was available
32704 (@pxref{Channels}).
32706 @item configuration.scm
32707 This is the file that was passed as the value for this
32708 @code{provenance-service-type} service. By default, @command{guix
32709 system reconfigure} automatically passes the OS configuration file it
32710 received on the command line.
32713 This contains the same information as the two other files but in a
32714 format that is more readily processable.
32717 In general, these two pieces of information (channels and configuration
32718 file) are enough to reproduce the operating system ``from source''.
32721 This information is necessary to rebuild your operating system, but it
32722 is not always sufficient. In particular, @file{configuration.scm}
32723 itself is insufficient if it is not self-contained---if it refers to
32724 external Guile modules or to extra files. If you want
32725 @file{configuration.scm} to be self-contained, we recommend that modules
32726 or files it refers to be part of a channel.
32728 Besides, provenance meta-data is ``silent'' in the sense that it does
32729 not change the bits contained in your system, @emph{except for the
32730 meta-data bits themselves}. Two different OS configurations or sets of
32731 channels can lead to the same system, bit-for-bit; when
32732 @code{provenance-service-type} is used, these two systems will have
32733 different meta-data and thus different store file names, which makes
32734 comparison less trivial.
32737 This service is automatically added to your operating system
32738 configuration when you use @command{guix system reconfigure},
32739 @command{guix system init}, or @command{guix deploy}.
32742 @node Shepherd Services
32743 @subsection Shepherd Services
32745 @cindex shepherd services
32747 @cindex init system
32748 The @code{(gnu services shepherd)} module provides a way to define
32749 services managed by the GNU@tie{}Shepherd, which is the
32750 initialization system---the first process that is started when the
32751 system boots, also known as PID@tie{}1
32752 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
32754 Services in the Shepherd can depend on each other. For instance, the
32755 SSH daemon may need to be started after the syslog daemon has been
32756 started, which in turn can only happen once all the file systems have
32757 been mounted. The simple operating system defined earlier (@pxref{Using
32758 the Configuration System}) results in a service graph like this:
32760 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
32762 You can actually generate such a graph for any operating system
32763 definition using the @command{guix system shepherd-graph} command
32764 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
32766 The @code{%shepherd-root-service} is a service object representing
32767 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
32768 by passing it lists of @code{<shepherd-service>} objects.
32770 @deftp {Data Type} shepherd-service
32771 The data type representing a service managed by the Shepherd.
32774 @item @code{provision}
32775 This is a list of symbols denoting what the service provides.
32777 These are the names that may be passed to @command{herd start},
32778 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
32779 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
32780 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
32782 @item @code{requirement} (default: @code{'()})
32783 List of symbols denoting the Shepherd services this one depends on.
32785 @cindex one-shot services, for the Shepherd
32786 @item @code{one-shot?} (default: @code{#f})
32787 Whether this service is @dfn{one-shot}. One-shot services stop immediately
32788 after their @code{start} action has completed. @xref{Slots of services,,,
32789 shepherd, The GNU Shepherd Manual}, for more info.
32791 @item @code{respawn?} (default: @code{#t})
32792 Whether to restart the service when it stops, for instance when the
32793 underlying process dies.
32796 @itemx @code{stop} (default: @code{#~(const #f)})
32797 The @code{start} and @code{stop} fields refer to the Shepherd's
32798 facilities to start and stop processes (@pxref{Service De- and
32799 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
32800 G-expressions that get expanded in the Shepherd configuration file
32801 (@pxref{G-Expressions}).
32803 @item @code{actions} (default: @code{'()})
32804 @cindex actions, of Shepherd services
32805 This is a list of @code{shepherd-action} objects (see below) defining
32806 @dfn{actions} supported by the service, in addition to the standard
32807 @code{start} and @code{stop} actions. Actions listed here become available as
32808 @command{herd} sub-commands:
32811 herd @var{action} @var{service} [@var{arguments}@dots{}]
32814 @item @code{auto-start?} (default: @code{#t})
32815 Whether this service should be started automatically by the Shepherd. If it
32816 is @code{#f} the service has to be started manually with @code{herd start}.
32818 @item @code{documentation}
32819 A documentation string, as shown when running:
32822 herd doc @var{service-name}
32825 where @var{service-name} is one of the symbols in @code{provision}
32826 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
32828 @item @code{modules} (default: @code{%default-modules})
32829 This is the list of modules that must be in scope when @code{start} and
32830 @code{stop} are evaluated.
32835 @deftp {Data Type} shepherd-action
32836 This is the data type that defines additional actions implemented by a
32837 Shepherd service (see above).
32841 Symbol naming the action.
32843 @item documentation
32844 This is a documentation string for the action. It can be viewed by running:
32847 herd doc @var{service} action @var{action}
32851 This should be a gexp that evaluates to a procedure of at least one argument,
32852 which is the ``running value'' of the service (@pxref{Slots of services,,,
32853 shepherd, The GNU Shepherd Manual}).
32856 The following example defines an action called @code{say-hello} that kindly
32862 (documentation "Say hi!")
32863 (procedure #~(lambda (running . args)
32864 (format #t "Hello, friend! arguments: ~s\n"
32869 Assuming this action is added to the @code{example} service, then you can do:
32872 # herd say-hello example
32873 Hello, friend! arguments: ()
32874 # herd say-hello example a b c
32875 Hello, friend! arguments: ("a" "b" "c")
32878 This, as you can see, is a fairly sophisticated way to say hello.
32879 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
32883 @defvr {Scheme Variable} shepherd-root-service-type
32884 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
32886 This is the service type that extensions target when they want to create
32887 shepherd services (@pxref{Service Types and Services}, for an example).
32888 Each extension must pass a list of @code{<shepherd-service>}. Its
32889 value must be a @code{shepherd-configuration}, as described below.
32892 @deftp {Data Type} shepherd-configuration
32893 This data type represents the Shepherd's configuration.
32896 @item shepherd (default: @code{shepherd})
32897 The Shepherd package to use.
32899 @item services (default: @code{'()})
32900 A list of @code{<shepherd-service>} to start.
32901 You should probably use the service extension
32902 mechanism instead (@pxref{Shepherd Services}).
32906 The following example specifies the Shepherd package for the operating
32912 (services (append (list openssh-service-type))
32916 ;; Use own Shepherd package.
32917 (essential-services
32918 (modify-services (operating-system-default-essential-services
32919 this-operating-system)
32920 (shepherd-root-service-type config => (shepherd-configuration
32922 (shepherd my-shepherd))))))
32925 @defvr {Scheme Variable} %shepherd-root-service
32926 This service represents PID@tie{}1.
32930 @node Documentation
32931 @chapter Documentation
32933 @cindex documentation, searching for
32934 @cindex searching for documentation
32935 @cindex Info, documentation format
32937 @cindex manual pages
32938 In most cases packages installed with Guix come with documentation.
32939 There are two main documentation formats: ``Info'', a browseable
32940 hypertext format used for GNU software, and ``manual pages'' (or ``man
32941 pages''), the linear documentation format traditionally found on Unix.
32942 Info manuals are accessed with the @command{info} command or with Emacs,
32943 and man pages are accessed using @command{man}.
32945 You can look for documentation of software installed on your system by
32946 keyword. For example, the following command searches for information
32947 about ``TLS'' in Info manuals:
32951 "(emacs)Network Security" -- STARTTLS
32952 "(emacs)Network Security" -- TLS
32953 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
32954 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
32959 The command below searches for the same keyword in man pages:
32963 SSL (7) - OpenSSL SSL/TLS library
32964 certtool (1) - GnuTLS certificate tool
32968 These searches are purely local to your computer so you have the
32969 guarantee that documentation you find corresponds to what you have
32970 actually installed, you can access it off-line, and your privacy is
32973 Once you have these results, you can view the relevant documentation by
32977 $ info "(gnutls)Core TLS API"
32987 Info manuals contain sections and indices as well as hyperlinks like
32988 those found in Web pages. The @command{info} reader (@pxref{Top, Info
32989 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
32990 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
32991 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
32992 Introduction}, for an introduction to Info navigation.
32994 @node Installing Debugging Files
32995 @chapter Installing Debugging Files
32997 @cindex debugging files
32998 Program binaries, as produced by the GCC compilers for instance, are
32999 typically written in the ELF format, with a section containing
33000 @dfn{debugging information}. Debugging information is what allows the
33001 debugger, GDB, to map binary code to source code; it is required to
33002 debug a compiled program in good conditions.
33004 This chapter explains how to use separate debug info when packages
33005 provide it, and how to rebuild packages with debug info when it's
33009 * Separate Debug Info:: Installing 'debug' outputs.
33010 * Rebuilding Debug Info:: Building missing debug info.
33013 @node Separate Debug Info
33014 @section Separate Debug Info
33016 The problem with debugging information is that is takes up a fair amount
33017 of disk space. For example, debugging information for the GNU C Library
33018 weighs in at more than 60 MiB@. Thus, as a user, keeping all the
33019 debugging info of all the installed programs is usually not an option.
33020 Yet, space savings should not come at the cost of an impediment to
33021 debugging---especially in the GNU system, which should make it easier
33022 for users to exert their computing freedom (@pxref{GNU Distribution}).
33024 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
33025 mechanism that allows users to get the best of both worlds: debugging
33026 information can be stripped from the binaries and stored in separate
33027 files. GDB is then able to load debugging information from those files,
33028 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
33031 The GNU distribution takes advantage of this by storing debugging
33032 information in the @code{lib/debug} sub-directory of a separate package
33033 output unimaginatively called @code{debug} (@pxref{Packages with
33034 Multiple Outputs}). Users can choose to install the @code{debug} output
33035 of a package when they need it. For instance, the following command
33036 installs the debugging information for the GNU C Library and for GNU
33040 guix install glibc:debug guile:debug
33043 GDB must then be told to look for debug files in the user's profile, by
33044 setting the @code{debug-file-directory} variable (consider setting it
33045 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
33049 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
33052 From there on, GDB will pick up debugging information from the
33053 @file{.debug} files under @file{~/.guix-profile/lib/debug}.
33055 In addition, you will most likely want GDB to be able to show the source
33056 code being debugged. To do that, you will have to unpack the source
33057 code of the package of interest (obtained with @code{guix build
33058 --source}, @pxref{Invoking guix build}), and to point GDB to that source
33059 directory using the @code{directory} command (@pxref{Source Path,
33060 @code{directory},, gdb, Debugging with GDB}).
33062 @c XXX: keep me up-to-date
33063 The @code{debug} output mechanism in Guix is implemented by the
33064 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
33065 opt-in---debugging information is available only for the packages with
33066 definitions explicitly declaring a @code{debug} output. To check
33067 whether a package has a @code{debug} output, use @command{guix package
33068 --list-available} (@pxref{Invoking guix package}).
33070 Read on for how to deal with packages lacking a @code{debug} output.
33072 @node Rebuilding Debug Info
33073 @section Rebuilding Debug Info
33075 @cindex debugging info, rebuilding
33076 As we saw above, some packages, but not all, provide debugging info in a
33077 @code{debug} output. What can you do when debugging info is missing?
33078 The @option{--with-debug-info} option provides a solution to that: it
33079 allows you to rebuild the package(s) for which debugging info is
33080 missing---and only those---and to graft those onto the application
33081 you're debugging. Thus, while it's not as fast as installing a
33082 @code{debug} output, it is relatively inexpensive.
33084 Let's illustrate that. Suppose you're experiencing a bug in Inkscape
33085 and would like to see what's going on in GLib, a library that's deep
33086 down in its dependency graph. As it turns out, GLib does not have a
33087 @code{debug} output and the backtrace GDB shows is all sadness:
33091 #0 0x00007ffff5f92190 in g_getenv ()
33092 from /gnu/store/@dots{}-glib-2.62.6/lib/libglib-2.0.so.0
33093 #1 0x00007ffff608a7d6 in gobject_init_ctor ()
33094 from /gnu/store/@dots{}-glib-2.62.6/lib/libgobject-2.0.so.0
33095 #2 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=1, argv=argv@@entry=0x7fffffffcfd8,
33096 env=env@@entry=0x7fffffffcfe8) at dl-init.c:72
33097 #3 0x00007ffff7fe2866 in call_init (env=0x7fffffffcfe8, argv=0x7fffffffcfd8, argc=1, l=<optimized out>)
33101 To address that, you install Inkscape linked against a variant GLib that
33102 contains debug info:
33105 guix install inkscape --with-debug-info=glib
33108 This time, debugging will be a whole lot nicer:
33111 $ gdb --args sh -c 'exec inkscape'
33114 Function "g_getenv" not defined.
33115 Make breakpoint pending on future shared library load? (y or [n]) y
33116 Breakpoint 1 (g_getenv) pending.
33118 Starting program: /gnu/store/@dots{}-profile/bin/sh -c exec\ inkscape
33121 #0 g_getenv (variable=variable@@entry=0x7ffff60c7a2e "GOBJECT_DEBUG") at ../glib-2.62.6/glib/genviron.c:252
33122 #1 0x00007ffff608a7d6 in gobject_init () at ../glib-2.62.6/gobject/gtype.c:4380
33123 #2 gobject_init_ctor () at ../glib-2.62.6/gobject/gtype.c:4493
33124 #3 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=3, argv=argv@@entry=0x7fffffffd088,
33125 env=env@@entry=0x7fffffffd0a8) at dl-init.c:72
33131 Note that there can be packages for which @option{--with-debug-info}
33132 will not have the desired effect. @xref{Package Transformation Options,
33133 @option{--with-debug-info}}, for more information.
33135 @node Security Updates
33136 @chapter Security Updates
33138 @cindex security updates
33139 @cindex security vulnerabilities
33140 Occasionally, important security vulnerabilities are discovered in software
33141 packages and must be patched. Guix developers try hard to keep track of
33142 known vulnerabilities and to apply fixes as soon as possible in the
33143 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
33144 containing only security updates). The @command{guix lint} tool helps
33145 developers find out about vulnerable versions of software packages in the
33150 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
33151 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
33152 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
33156 @xref{Invoking guix lint}, for more information.
33158 Guix follows a functional
33159 package management discipline (@pxref{Introduction}), which implies
33160 that, when a package is changed, @emph{every package that depends on it}
33161 must be rebuilt. This can significantly slow down the deployment of
33162 fixes in core packages such as libc or Bash, since basically the whole
33163 distribution would need to be rebuilt. Using pre-built binaries helps
33164 (@pxref{Substitutes}), but deployment may still take more time than
33168 To address this, Guix implements @dfn{grafts}, a mechanism that allows
33169 for fast deployment of critical updates without the costs associated
33170 with a whole-distribution rebuild. The idea is to rebuild only the
33171 package that needs to be patched, and then to ``graft'' it onto packages
33172 explicitly installed by the user and that were previously referring to
33173 the original package. The cost of grafting is typically very low, and
33174 order of magnitudes lower than a full rebuild of the dependency chain.
33176 @cindex replacements of packages, for grafts
33177 For instance, suppose a security update needs to be applied to Bash.
33178 Guix developers will provide a package definition for the ``fixed''
33179 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
33180 Packages}). Then, the original package definition is augmented with a
33181 @code{replacement} field pointing to the package containing the bug fix:
33188 (replacement bash-fixed)))
33191 From there on, any package depending directly or indirectly on Bash---as
33192 reported by @command{guix gc --requisites} (@pxref{Invoking guix
33193 gc})---that is installed is automatically ``rewritten'' to refer to
33194 @code{bash-fixed} instead of @code{bash}. This grafting process takes
33195 time proportional to the size of the package, usually less than a
33196 minute for an ``average'' package on a recent machine. Grafting is
33197 recursive: when an indirect dependency requires grafting, then grafting
33198 ``propagates'' up to the package that the user is installing.
33200 Currently, the length of the name and version of the graft and that of
33201 the package it replaces (@code{bash-fixed} and @code{bash} in the example
33202 above) must be equal. This restriction mostly comes from the fact that
33203 grafting works by patching files, including binary files, directly.
33204 Other restrictions may apply: for instance, when adding a graft to a
33205 package providing a shared library, the original shared library and its
33206 replacement must have the same @code{SONAME} and be binary-compatible.
33208 The @option{--no-grafts} command-line option allows you to forcefully
33209 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
33213 guix build bash --no-grafts
33217 returns the store file name of the original Bash, whereas:
33224 returns the store file name of the ``fixed'', replacement Bash. This
33225 allows you to distinguish between the two variants of Bash.
33227 To verify which Bash your whole profile refers to, you can run
33228 (@pxref{Invoking guix gc}):
33231 guix gc -R `readlink -f ~/.guix-profile` | grep bash
33235 @dots{} and compare the store file names that you get with those above.
33236 Likewise for a complete Guix system generation:
33239 guix gc -R `guix system build my-config.scm` | grep bash
33242 Lastly, to check which Bash running processes are using, you can use the
33243 @command{lsof} command:
33246 lsof | grep /gnu/store/.*bash
33250 @node Bootstrapping
33251 @chapter Bootstrapping
33253 @c Adapted from the ELS 2013 paper.
33255 @cindex bootstrapping
33257 Bootstrapping in our context refers to how the distribution gets built
33258 ``from nothing''. Remember that the build environment of a derivation
33259 contains nothing but its declared inputs (@pxref{Introduction}). So
33260 there's an obvious chicken-and-egg problem: how does the first package
33261 get built? How does the first compiler get compiled?
33263 It is tempting to think of this question as one that only die-hard
33264 hackers may care about. However, while the answer to that question is
33265 technical in nature, its implications are wide-ranging. How the
33266 distribution is bootstrapped defines the extent to which we, as
33267 individuals and as a collective of users and hackers, can trust the
33268 software we run. It is a central concern from the standpoint of
33269 @emph{security} and from a @emph{user freedom} viewpoint.
33271 @cindex bootstrap binaries
33272 The GNU system is primarily made of C code, with libc at its core. The
33273 GNU build system itself assumes the availability of a Bourne shell and
33274 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
33275 `grep'. Furthermore, build programs---programs that run
33276 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
33277 (@pxref{Derivations}). Consequently, to be able to build anything at
33278 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
33279 Binutils, libc, and the other packages mentioned above---the
33280 @dfn{bootstrap binaries}.
33282 These bootstrap binaries are ``taken for granted'', though we can also
33283 re-create them if needed (@pxref{Preparing to Use the Bootstrap
33287 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
33288 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
33291 @node Reduced Binary Seed Bootstrap
33292 @section The Reduced Binary Seed Bootstrap
33294 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
33295 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
33296 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
33297 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
33298 ``taken for granted.''
33300 Taking the bootstrap binaries for granted means that we consider them to
33301 be a correct and trustworthy ``seed'' for building the complete system.
33302 Therein lies a problem: the combined size of these bootstrap binaries is
33303 about 250MB (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing
33304 or even inspecting these is next to impossible.
33306 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a
33307 ``Reduced Binary Seed'' bootstrap @footnote{We would like to say: ``Full
33308 Source Bootstrap'' and while we are working towards that goal it would
33309 be hyperbole to use that term for what we do now.}.
33311 The Reduced Binary Seed bootstrap removes the most critical tools---from a
33312 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
33313 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
33314 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
33315 written in Scheme and the Mes C Library, built for TinyCC and for GCC).
33317 Using these new binary seeds the ``missing'' Binutils, GCC, and the GNU
33318 C Library are built from source. From here on the more traditional
33319 bootstrap process resumes. This approach has reduced the bootstrap
33320 binaries in size to about 145MB in Guix v1.1.
33322 The next step that Guix has taken is to replace the shell and all its
33323 utilities with implementations in Guile Scheme, the @emph{Scheme-only
33324 bootstrap}. Gash (@pxref{Gash,,, gash, The Gash manual}) is a
33325 POSIX-compatible shell that replaces Bash, and it comes with Gash Utils
33326 which has minimalist replacements for Awk, the GNU Core Utilities, Grep,
33327 Gzip, Sed, and Tar. The rest of the bootstrap binary seeds that were
33328 removed are now built from source.
33330 Building the GNU System from source is currently only possibly by adding
33331 some historical GNU packages as intermediate steps@footnote{Packages
33332 such as @code{gcc-2.95.3}, @code{binutils-2.14}, @code{glibc-2.2.5},
33333 @code{gzip-1.2.4}, @code{tar-1.22}, and some others. For details, see
33334 @file{gnu/packages/commencement.scm}.}. As Gash and Gash Utils mature,
33335 and GNU packages become more bootstrappable again (e.g., new releases of
33336 GNU Sed will also ship as gzipped tarballs again, as alternative to the
33337 hard to bootstrap @code{xz}-compression), this set of added packages can
33338 hopefully be reduced again.
33340 The graph below shows the resulting dependency graph for
33341 @code{gcc-core-mesboot0}, the bootstrap compiler used for the
33342 traditional bootstrap of the rest of the Guix System.
33344 @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
33345 @image{images/gcc-core-mesboot0-graph,6in,,Dependency graph of gcc-core-mesboot0}
33347 The only significant binary bootstrap seeds that remain@footnote{
33348 Ignoring the 68KB @code{mescc-tools}; that will be removed later,
33349 together with @code{mes}.} are a Scheme intepreter and a Scheme
33350 compiler: GNU Mes and GNU Guile@footnote{Not shown in this graph are the
33351 static binaries for @file{bash}, @code{tar}, and @code{xz} that are used
33352 to get Guile running.}.
33354 This further reduction has brought down the size of the binary seed to
33355 about 60MB for @code{i686-linux} and @code{x86_64-linux}.
33357 Work is ongoing to remove all binary blobs from our free software
33358 bootstrap stack, working towards a Full Source Bootstrap. Also ongoing
33359 is work to bring these bootstraps to the @code{arm-linux} and
33360 @code{aarch64-linux} architectures and to the Hurd.
33362 If you are interested, join us on @samp{#bootstrappable} on the Freenode
33363 IRC network or discuss on @email{bug-mes@@gnu.org} or
33364 @email{gash-devel@@nongnu.org}.
33366 @node Preparing to Use the Bootstrap Binaries
33367 @section Preparing to Use the Bootstrap Binaries
33369 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
33370 @c large image, it's hard to scroll. Oh well.
33371 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
33373 The figure above shows the very beginning of the dependency graph of the
33374 distribution, corresponding to the package definitions of the @code{(gnu
33375 packages bootstrap)} module. A similar figure can be generated with
33376 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
33379 guix graph -t derivation \
33380 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
33381 | dot -Tps > gcc.ps
33384 or, for the further Reduced Binary Seed bootstrap
33387 guix graph -t derivation \
33388 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
33389 | dot -Tps > mes.ps
33392 At this level of detail, things are
33393 slightly complex. First, Guile itself consists of an ELF executable,
33394 along with many source and compiled Scheme files that are dynamically
33395 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
33396 tarball shown in this graph. This tarball is part of Guix's ``source''
33397 distribution, and gets inserted into the store with @code{add-to-store}
33398 (@pxref{The Store}).
33400 But how do we write a derivation that unpacks this tarball and adds it
33401 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
33402 derivation---the first one that gets built---uses @code{bash} as its
33403 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
33404 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
33405 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
33406 the Guix source distribution, whose sole purpose is to allow the Guile
33407 tarball to be unpacked.
33409 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
33410 Guile that can be used to run subsequent build programs. Its first task
33411 is to download tarballs containing the other pre-built binaries---this
33412 is what the @file{.tar.xz.drv} derivations do. Guix modules such as
33413 @code{ftp-client.scm} are used for this purpose. The
33414 @code{module-import.drv} derivations import those modules in a directory
33415 in the store, using the original layout. The
33416 @code{module-import-compiled.drv} derivations compile those modules, and
33417 write them in an output directory with the right layout. This
33418 corresponds to the @code{#:modules} argument of
33419 @code{build-expression->derivation} (@pxref{Derivations}).
33421 Finally, the various tarballs are unpacked by the derivations
33422 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
33423 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
33424 point we have a working C tool chain.
33426 @unnumberedsec Building the Build Tools
33428 Bootstrapping is complete when we have a full tool chain that does not
33429 depend on the pre-built bootstrap tools discussed above. This
33430 no-dependency requirement is verified by checking whether the files of
33431 the final tool chain contain references to the @file{/gnu/store}
33432 directories of the bootstrap inputs. The process that leads to this
33433 ``final'' tool chain is described by the package definitions found in
33434 the @code{(gnu packages commencement)} module.
33436 The @command{guix graph} command allows us to ``zoom out'' compared to
33437 the graph above, by looking at the level of package objects instead of
33438 individual derivations---remember that a package may translate to
33439 several derivations, typically one derivation to download its source,
33440 one to build the Guile modules it needs, and one to actually build the
33441 package from source. The command:
33444 guix graph -t bag \
33445 -e '(@@@@ (gnu packages commencement)
33446 glibc-final-with-bootstrap-bash)' | xdot -
33450 displays the dependency graph leading to the ``final'' C
33451 library@footnote{You may notice the @code{glibc-intermediate} label,
33452 suggesting that it is not @emph{quite} final, but as a good
33453 approximation, we will consider it final.}, depicted below.
33455 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
33457 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
33458 The first tool that gets built with the bootstrap binaries is
33459 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
33460 for all the following packages. From there Findutils and Diffutils get
33463 Then come the first-stage Binutils and GCC, built as pseudo cross
33464 tools---i.e., with @option{--target} equal to @option{--host}. They are
33465 used to build libc. Thanks to this cross-build trick, this libc is
33466 guaranteed not to hold any reference to the initial tool chain.
33468 From there the final Binutils and GCC (not shown above) are built. GCC
33469 uses @command{ld} from the final Binutils, and links programs against
33470 the just-built libc. This tool chain is used to build the other
33471 packages used by Guix and by the GNU Build System: Guile, Bash,
33474 And voilà! At this point we have the complete set of build tools that
33475 the GNU Build System expects. These are in the @code{%final-inputs}
33476 variable of the @code{(gnu packages commencement)} module, and are
33477 implicitly used by any package that uses @code{gnu-build-system}
33478 (@pxref{Build Systems, @code{gnu-build-system}}).
33481 @unnumberedsec Building the Bootstrap Binaries
33483 @cindex bootstrap binaries
33484 Because the final tool chain does not depend on the bootstrap binaries,
33485 those rarely need to be updated. Nevertheless, it is useful to have an
33486 automated way to produce them, should an update occur, and this is what
33487 the @code{(gnu packages make-bootstrap)} module provides.
33489 The following command builds the tarballs containing the bootstrap binaries
33490 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
33491 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
33492 and Guile, and a tarball containing a mixture of Coreutils and other basic
33493 command-line tools):
33496 guix build bootstrap-tarballs
33499 The generated tarballs are those that should be referred to in the
33500 @code{(gnu packages bootstrap)} module mentioned at the beginning of
33503 Still here? Then perhaps by now you've started to wonder: when do we
33504 reach a fixed point? That is an interesting question! The answer is
33505 unknown, but if you would like to investigate further (and have
33506 significant computational and storage resources to do so), then let us
33509 @unnumberedsec Reducing the Set of Bootstrap Binaries
33511 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
33512 binary code! Why is that a problem? It's a problem because these big chunks
33513 of binary code are practically non-auditable, which makes it hard to establish
33514 what source code produced them. Every unauditable binary also leaves us
33515 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
33516 paper @emph{Reflections on Trusting Trust}.
33518 This is mitigated by the fact that our bootstrap binaries were generated
33519 from an earlier Guix revision. Nevertheless it lacks the level of
33520 transparency that we get in the rest of the package dependency graph,
33521 where Guix always gives us a source-to-binary mapping. Thus, our goal
33522 is to reduce the set of bootstrap binaries to the bare minimum.
33524 The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
33525 on-going projects to do that. One of these is about replacing the
33526 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
33527 of increasing complexity, which could be built from source starting from
33528 a simple and auditable assembler.
33530 Our first major achievement is the replacement of of GCC, the GNU C Library
33531 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
33532 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
33533 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
33534 bootstrapped yet and thus we inject them as binary seeds. We call this the
33535 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
33536 binaries! Also, it has eliminated the C compiler binary; i686-linux and
33537 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
33539 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
33540 also looking at any other bootstrap binaries. Your help is welcome!
33543 @chapter Porting to a New Platform
33545 As discussed above, the GNU distribution is self-contained, and
33546 self-containment is achieved by relying on pre-built ``bootstrap
33547 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
33548 operating system kernel, CPU architecture, and application binary
33549 interface (ABI). Thus, to port the distribution to a platform that is
33550 not yet supported, one must build those bootstrap binaries, and update
33551 the @code{(gnu packages bootstrap)} module to use them on that platform.
33553 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
33554 When everything goes well, and assuming the GNU tool chain supports the
33555 target platform, this can be as simple as running a command like this
33559 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
33562 For this to work, the @code{glibc-dynamic-linker} procedure in
33563 @code{(gnu packages bootstrap)} must be augmented to return the right
33564 file name for libc's dynamic linker on that platform; likewise,
33565 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
33566 taught about the new platform.
33568 Once these are built, the @code{(gnu packages bootstrap)} module needs
33569 to be updated to refer to these binaries on the target platform. That
33570 is, the hashes and URLs of the bootstrap tarballs for the new platform
33571 must be added alongside those of the currently supported platforms. The
33572 bootstrap Guile tarball is treated specially: it is expected to be
33573 available locally, and @file{gnu/local.mk} has rules to download it for
33574 the supported architectures; a rule for the new platform must be added
33577 In practice, there may be some complications. First, it may be that the
33578 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
33579 above) is not recognized by all the GNU tools. Typically, glibc
33580 recognizes some of these, whereas GCC uses an extra @option{--with-abi}
33581 configure flag (see @code{gcc.scm} for examples of how to handle this).
33582 Second, some of the required packages could fail to build for that
33583 platform. Lastly, the generated binaries could be broken for some
33586 @c *********************************************************************
33587 @include contributing.texi
33589 @c *********************************************************************
33590 @node Acknowledgments
33591 @chapter Acknowledgments
33593 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
33594 which was designed and
33595 implemented by Eelco Dolstra, with contributions from other people (see
33596 the @file{nix/AUTHORS} file in Guix). Nix pioneered functional package
33597 management, and promoted unprecedented features, such as transactional
33598 package upgrades and rollbacks, per-user profiles, and referentially
33599 transparent build processes. Without this work, Guix would not exist.
33601 The Nix-based software distributions, Nixpkgs and NixOS, have also been
33602 an inspiration for Guix.
33604 GNU@tie{}Guix itself is a collective work with contributions from a
33605 number of people. See the @file{AUTHORS} file in Guix for more
33606 information on these fine people. The @file{THANKS} file lists people
33607 who have helped by reporting bugs, taking care of the infrastructure,
33608 providing artwork and themes, making suggestions, and more---thank you!
33611 @c *********************************************************************
33612 @node GNU Free Documentation License
33613 @appendix GNU Free Documentation License
33614 @cindex license, GNU Free Documentation License
33615 @include fdl-1.3.texi
33617 @c *********************************************************************
33618 @node Concept Index
33619 @unnumbered Concept Index
33622 @node Programming Index
33623 @unnumbered Programming Index
33624 @syncodeindex tp fn
33625 @syncodeindex vr fn
33630 @c Local Variables:
33631 @c ispell-local-dictionary: "american";